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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of the Taiwan Patent Application Serial Number 102126068, filed on Jul. 22, 2013, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a porous amorphous alloy artificial joint having suitable Young's modulus, yield strength, porosity and pore size suitable for cell growth, which is manufactured under various pressures and temperatures by virtue of superplasticity of the amorphous alloy in the supercooled liquid (SCL) region.
[0004] 2. Description of Related Art
[0005] Artificial joint can be considered as one of many important progresses in the medical field in the past few centuries, as it benefits many degenerative arthritis patients. The quality of life for those who have lost mobility can be significantly improved after receiving an artificial hip joint or an artificial knee joint. According to statistics, the number of artificial joint replacement in the United States has reached up to 150,000 or more each year, and gradually increases, indicating that it has become a common orthopedic surgery.
[0006] The materials used for making an artificial joint must have good corrosion and impact resistances to prevent peripheral cells from over damage during its use. In addition, biocompatible and porous materials are selected as the material for an artificial joint, in order to facilitate cell growth into the artificial joint to promote recovery of lesion. A typical biomedical porous material is generally made by stainless steel or titanium alloy porous material at a processing temperature of up to 1273 K, resulting in overly high Young's modulus and undesirable stress shielding effect, which easily slows down the recovery rate of the affected region that receives the implant.
[0007] Therefore, what is needed is to find an artificial joint suitable for cell growth and having an appropriate Young's modulus and yield strength, in order to improve the current state of the art for artificial joints.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a porous amorphous alloy artificial joint complying with Young's modulus of the human bones, and having a pore size and porosity suitable for cell growth, to facilitate the application in transplantation of the artificial joints. Another object of the present invention is to provide a method for manufacturing the above porous amorphous alloy artificial joint.
[0009] To achieve the above object, the present invention provides a porous amorphous alloy artificial joint formed of at least one of amorphous alloy compounds represented by Formula 1 to Formula 4:
[0000] (Zr a Cu b Ni c Al d ) 100−x Si x ,
[0000] wherein 45≦ a ≦75, 15≦ b ≦45, 5≦ c ≦15, 5≦ d ≦10, 1≦ x ≦10, [Formula 1]
[0000] Zr e Cu f Ag g Al h ) 100 −y Si y
[0000] wherein 45≦ e ≦75, 25≦ f ≦45, 5≦ g ≦15, 5≦ h ≦15, 1≦ y ≦10, [Formula 2]
[0000] Ti i Ta j Si k Zr l ,
[0000] wherein 30≦ i ≦80, 0≦ j ≦20, 1≦ k ≦20, 5≦1≦40, [Formula 3]
[0000] Ti m Cu n Zr o Pd p ,
[0000] wherein 40≦ m ≦75, 30≦ n ≦40, 5≦ o ≦15, 10≦ p ≦20. [Formula 4]
[0010] The amorphous alloy compound is preferably at least one selected from the group consisting of Zr 53 Cu 30 Ni 9 Al 8 , (Zr 53 Cu 30 Ni 9 Al 8 ) 100−X Si X , Zr 48 Cu 36 Ag 8 Al 8 , (Zr 48 Cu 36 Ag 8 Al 8 ) 100−y Si y , Ti 40 Zr 10 Cu 36 Pd 14 , Ti 60 Ta 15 Si 15 Zr 10 , Ti 62 Ta 13 Si 15 Zr 10 , Ti 65 Ta 10 Si 15 Zr 10 , Ti 60 Zr 20 Ta 5 Si 15 , Ti 60 Zr 22 Ta 3 Si 15 , and Ti 45 Cu 35 Zr 20 , wherein 1≦x≦10, 1≦y≦10, more preferably at least one selected from the group consisting of Zr 53 Cu 30 Ni 9 Al 8 and Ti 40 Zr 10 Cu 36 Pd 14 , and most preferably Zr 53 Cu 30 Ni 9 Al 8 and Ti 40 Zr 10 Cu 36 Pd 14
[0011] The porous amorphous alloy artificial joint has a pore size suitable for cell growth, which is preferably 200-400 and more preferably 250-350 and preferably has a porosity of 40-75%, and more preferably 45-65%. Furthermore, the above-described porous amorphous alloy artificial joint has a Young's modulus and yield strength complying with that of normal joints, wherein the Young's modulus may be 5-25 GPa, and preferably 10-20 GPa, and the yield strength may be 50-350 MPa, and preferably 150-250 MPa.
[0012] To prepare the porous amorphous alloy artificial joint, the present invention further provides a method for manufacturing a porous amorphous alloy artificial joint, comprising the following sequential steps:
[0013] First, (A) mixing an amorphous alloy power and a water-soluble salt to form a mixture, wherein the porous amorphous alloy power is formed of at least one of amorphous alloy compounds represented by Formula 1 to Formula 4:
[0000] (Zr a Cu b Ni c Al d ) 100−x Si x ,
[0000] wherein 45≦ a ≦75, 15≦ b ≦45, 5≦ c ≦15, 5≦ d ≦10, 1≦ x ≦10, [Formula 1]
[0000] Zr e Cu f Ag g Al h ) 100 −y Si y
[0000] wherein 45≦ e ≦75, 25≦ f ≦45, 5≦ g ≦15, 5≦ h ≦15, 1≦ y ≦10, [Formula 2]
[0000] Ti i Ta j Si k Zr l ,
[0000] wherein 30≦ i ≦80, 0≦ j ≦20, 1≦ k ≦20, 5≦1≦40, [Formula 3]
[0000] Ti m Cu n Zr o Pd p ,
[0000] wherein 40≦ m ≦75, 30≦ n ≦40, 5≦ o ≦15, 10≦ p ≦20. [Formula 4]
[0014] Afterward, (B) subjecting the mixture to a hot pressing reaction; and then (C) dissolving the water-soluble salt in the mixture to form the porous amorphous alloy artificial joint.
[0015] The step (B) can be performed under an inert gas, such as nitrogen, helium, neon, argon, etc. The hot pressing reaction can be performed at a middle temperature of a supercooled liquid region of the porous amorphous alloy power, preferably ½(Tg+Tx)±20K, and more preferably ½(Tg+Tx)±10K. In the case of Zr 53 Cu 30 Ni 9 A1 8 and Ti 40 Zr 10 Cu 36 Pd 14 , the minimum temperature of the hot pressing reaction for Zr 53 Cu 30 Ni 9 Al 8 is 660K, and the minimum temperature of the hot pressing reaction for Ti 40 Zr 10 Cu 36 Pd 14 is 650K.
[0016] The hot pressing reaction may be performed under a pressure of 100-500 MPa, and preferably 250-350 MPa. In addition, the reaction time of the hot pressing reaction may be adjusted depending on processing conditions, and is preferably 5-15 minutes, and more preferably 6-12 minutes.
[0017] In step (A), the particle size of the amorphous alloy powder may be adjusted as desired, and is preferably 50-300 and more preferably 100-250 In addition, the water-soluble salt can be at least one selected from the group consisting of NaCl, KCl, CaCo 3 , and CaF 2 , and preferably NaCl.
[0018] The amorphous alloy compound is preferably at least one selected from the group consisting of Zr 53 Cu 30 Ni 9 Al 8 , (Zr 53 Cu 30 Ni 9 Al 8 ) 100−x Si x , Zr 48 Cu 36 Ag 8 Al 8 , (Zr 48 Cu 36 Ag 8 Al 8 ) 100−y Si y , Ti 40 Zr 10 Cu 36 Pd 14 , Ti 60 Ta 15 Si 15 Zr 10 , Ti 62 Ta_Si 15 Zr 10 , Ti 65 Ta 10 Si 15 Zr 10 , Ti 60 Zr 20 Ta 5 Si 15 , Ti 60 Zr 22 Ta 3 Si 15 , and Ti 45 Cu 35 Zr 20 , wherein 1≦x≦10, 1≦y≦10, more preferably at least one selected from the group consisting of Zr 53 Cu 30 Ni 9 Al 8 and Ti 40 Zr 10 Cu 36 Pd 14 , and most preferably Zr 53 Cu 30 Ni 9 Al 8 and Ti 40 Zr 10 Cu 36 Pd 14 .
[0019] In order to manufacture the porous amorphous alloy artificial joint with a preferable pore size, in the step (A), the water-soluble salt is preferably present in an amount of 50-90 vol %, and more preferably 60-70 vol %, based on a total volume of the mixture. Furthermore, a particle size of the water-soluble salt is preferably 150-300 and may be adjusted as desired as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0021] FIG. 1 shows the nucleation curve of Zr 53 Cu 30 Ni 9 Al 8 according to Examples 1-8 of the present invention.
[0022] FIGS. 2A-2H show the sectional views of the porous amorphous alloy artificial joint according to Examples 1-8 of the present invention.
[0023] FIGS. 3A-3D show images of the porous amorphous alloy artificial joint of Example 5 at 35, 200, 500, and 150 times magnification, respectively.
[0024] FIGS. 4A-4C show images of the porous amorphous alloy artificial joint of Example 8 at 35, 500 and 1000 times magnification, respectively.
[0025] FIGS. 5A-5B show images of the porous amorphous alloy artificial joint of Examples 1 and 8, respectively, at 1000 times magnification.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] Hereinafter, the actions and the effects of the present invention will be explained in more detail via specific examples of the invention. However, these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby. In addition, it is evident that various modifications, structures, processes, and changes may be made thereto without departing from the broader spirit and scope of the present disclosure.
Examples 1-8
[0027] In this Example, Zr-based amorphous alloy material was used. A porous artificial joint suitable for cell growth was prepared under various pressures and temperatures by virtue of the superplasticity of the amorphous alloy in the supercooled liquid (SCL) region. NaCl having different particle sizes was added to the Zr-based amorphous powder having a particle size of 50-300 μm, followed by hot pressing.
[0028] [Preparation of Porous Amorphous Alloy Powder]
[0029] Zr, Cu, Al, and Ni having a purity of 99.99% were molten into Zr 53 Cu 30 Ni 9 Al 8 Zr-based alloy ingot by arc-melting (with a power of 350 KW) according to the desired atomic percent of the alloy composition under an argon atmosphere. The alloy ingot was placed in a quartz tube (18 mm in diameter), vacuumed in a quenching melt-spinning chamber to a pressure of 2.0*10 −2 mbar and heated by a high-frequency coil (with a power of 5 KW) under vacuum. After melting (about 1-2 minutes), the molten liquid alloy was ejected onto a water-cooled copper wheel by using argon gas with a pressure of 4-6 kg/cm 2 . The copper wheel was operating at a rotational speed (tangential speed) of 10-20 m/s. For scraping the desired thin strip off from the wheel, a gap was adjusted to less than 1 mm between the copper wheel and the scraper.
[0030] The above Zr-based amorphous alloy thin strip was smashed into powder by a blender, and then prepared in the glove box (with an atmosphere of 95% argon, 5% hydrogen). The amorphous alloy powder and tungsten carbide balls were allocated in a weight ratio of 1 (the porous amorphous alloy powder): 10 (tungsten carbide) in a mill jar and ball milled under an atmosphere of pure argon after sealing.
[0031] Subsequently, the above substance was placed in a commercial ball mill (SPEX) to perform ball milling, and then the Zr-based amorphous alloy powder with various sizes of (53-297 μm) were sieved out using meshes of different sizes under the protective atmosphere in the glove box.
[0032] Tg (glass transition temperature), Tx (crystallization temperature) (10-40 K/min) at various rates were analyzed using non-isothermal DSC (Differential Scanning calorimetry), and then the real Tg, Tx was obtained by linear regression. Afterward, an isothermal DSC analysis was performed at the temperature ranging between the real Tg and Tx. The nucleation curve was obtained from the isothermal DSC analysis as shown in FIG. 1 . In this Example, the hot pressing reaction was performed at a temperature of 700-740 K and should be completed within 720 seconds (about 12 minutes), or crystallization would otherwise occur.
[0033] In addition, as for the Ti 40 Zr 10 Cu 36 Pd 1 Ti-based amorphous alloy powder, the hot pressing reaction was performed at a temperature of 650-680 K for less than 480 seconds.
[0034] [Preparation of Zr-Based Porous Amorphous Alloy Artificial Joint]
[0035] The above Zr 53 Cu 30 Ni 9 Al 8 amorphous alloy powder having a density of 6.88 g/cm 3 and the NaCl powder having a density of 2.16 g/cm 3 were mixed, wherein the particle size of the NaCl powder was between 150-300 μm, and the addition amount of the NaCl powder was calculated according to the following formula:
[0000] grams of NaCl=(grams of Zr 53 Cu 30 Ni 9 Al 8 powder)/(density of Zr 53 Cu 30 Ni 9 Al 8 powder)*(volume percentage of porous amorphous alloy)*(density of NaCl)
[0036] Subsequently, with a given particle size of NaCl (150-300 μm), the hot pressing reaction was performed using the amorphous alloy powders of varying sizes (53-297 μm) under varying hot pressing pressures (100-500 MPa). The reaction conditions are summarized in Table 1:
[0000]
TABLE 1
Particle size of
volume
amorphous alloy
percentage
porous amorphous
MPa
powder (μm)
of NaCl
alloy
Example 1
300
210-297
58%
Zr 53 Cu 30 Ni 9 Al 8
Example 2
300
149-210
60%
Zr 53 Cu 30 Ni 9 Al 8
Example 3
300
53-149
60%
Zr 53 Cu 30 Ni 9 Al 8
Example 4
300
60~
60%
Ti 40 Zr 10 Cu 36 Pd 14
Example 5
300
60~
60%
Zr 53 Cu 30 Ni 9 Al 8
Example 6
300
63-105
60%
Zr 53 Cu 30 Ni 9 Al 8
Example 7
500
60~
60%
Zr 53 Cu 30 Ni 9 Al 8
Example 8
400
60~
60%
Zr 53 Cu 30 Ni 9 Al 8
[0037] The sectional views of porous amorphous alloy artificial joint in Examples 1 to 8 are shown in FIGS. 2A-2H , wherein the pore size of Examples 1 to 6 were 250±20 μm, the pore size of Example 7 ( FIG. 2G ) was not measurable due to its non-uniformity, and the pore size of Example 8 was 100±30 μm. The real porosities of Examples 1 to 8 were 40-73%. The Zr-based porous amorphous alloy artificial joint in the most preferable Example 5 had a real porosity of 40-50%, a Young's modulus of 5-25GPa, and a yield strength of 50-320 MPa. Accordingly, the various physical properties of the porous amorphous alloy material can be effectively controlled by choice of the amorphous alloy powders with different particle sizes along with different hot pressing pressures. In the Examples of the present invention, it can be found that under a hot pressing pressure of 300 MPa, the porous artificial joint (with a pore size close to 300 μm) that was most suitable for cell growth could be obtained by mixing the Zr-based amorphous alloy powder with a particle size of 60 μm and 50-90 vol % of NaCl. Among the above, the porous amorphous alloy artificial joint with a porosity of 60% and a pore size of 265±22 μm in Example 5 was most appropriate for cell growth, as shown in FIGS. 3A-3D . The pore size in Example 8 was too small, only 102±30 μm, for cell growth, as shown in FIGS. 4A-4C . Further, referring to FIGS. 5A-5B , no obvious interface was found in the porous artificial joints, indicating a superior metallurgy process has been conducted during the Examples.
[0038] Taking Example 5 and 8 as examples, since interstices may be present between the amorphous alloy powders, or NaCl may encapsulate a few amorphous alloy powders during the process, a particle size of larger than 300 μm may be produced by using NaCl of either 150 μm or 300 μm in diameter.
[0039] In summary, in the supercooled liquid region (Tg+Tx)/2, under hot pressing pressure of 100-500 MPa, with an amorphous alloy powder having a particle size of 50-300 μm, the porous artificial joint having a high uniformity, meeting the properties of human joint, and suitable for cell growth can be obtained. Compared to the crystalline metal materials which need to be heated to close the melting point to exhibit a near superplastic property, the amorphous alloy powders Zr 53 Cu 30 Ni 9 Al 8 and Ti 40 Zr 10 Cu 36 Pd 14 of the present invention can be thermally shaped at 700-740 K, and 650-680 K, respectively, by hot pressing for an average time of 760-1820 seconds, providing advantages in processing ease and convenience.
[0040] It should be understood that these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby, and the scope of the present invention will be limited only by the appended claims. | The present invention relates to a porous amorphous alloy artificial joint and a manufacturing method thereof The porous amorphous alloy artificial joint is formed of at least one of amorphous alloy compounds represented by Formula 1 to Formula 4 as described in the present specification. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 13/359,822, filed Jan. 27, 2012, entitled “III-V Photonic Integration on Silicon,” by John E. Bowers, which is a continuation of application Ser. No. 11/534,560, filed Sep. 22, 2006, entitled “III-V PHOTONIC INTEGRATION ON SILICON,” by John E. Bowers (now U.S. Pat. No. 8,110,823), which claims the benefit under 35 U.S.C. Section 119(e) of the following commonly-assigned U.S. provisional patent applications:
Ser. No. 60/760,629, filed Jan. 20, 2006, entitled “OPTICAL GAIN AND ALSING ON SILICON,” by John E. Bowers, and
Ser. No. 60/795,064, filed Apr. 26, 2006, entitled “III-V PHOTONIC INTEGRATION ON SILICON,” by John E. Bowers, which applications are incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to semiconductor devices, and, more specifically, to integration of III-V optical devices with silicon substrates and circuits.
2. Description of the Related Art
Semiconductor chip level bonded devices have found uses in several consumer and commercial applications. Typically, semiconductor devices are made from a single type of material, or different types of material are grown onto a substrate based on lattice matching and compatible crystalline structures. Devices manufactured from III-V materials are typically grown on gallium arsenide or other compound semiconductor substrates. These devices are difficult to integrate with electronic devices fabricated on silicon.
However, there are many advantages to integrating electronic and photonic devices on a single substrate. Passive photonic devices such as arrayed waveguide routers (AWG) are commonly fabricated on silicon. Some active photonic devices have been demonstrated on silicon such as modulators and Raman lasers. However, most active photonic devices require single crystal material, which is difficult to grow on silicon because of the large lattice mismatch between the semiconductor with the proper bandgaps and silicon itself. The problem with the present discrete photonic devices is that the performance can be improved with integration, and the cost and size is much smaller. Silicon is a preferred semiconductor material, because it is easily processed, it is readily available for reasonable cost and high quality, and complex VLSI electronic circuits are readily available. However, silicon-based modulators or lasers or other photonic devices are not as efficient at light emission or absorption as their III-V based counterparts. It can be seen, then, that there is a need in the art for a larger scale integration between III-V materials and silicon.
SUMMARY OF THE INVENTION
To minimize the limitations in the prior art, and to minimize other limitations that will become apparent upon reading and understanding the present specification, the present invention provides a technology for making photonic integrated circuits on silicon. By bonding a wafer of III-V material as an active region to silicon and removing the substrate, the lasers, amplifiers, modulators, and other devices can be processed using standard photolithographic techniques on the silicon substrate. The coupling between the silicon waveguide and the III-V gain region allows for integration of low threshold lasers, tunable lasers, and other photonic devices and integrated circuits with Complimentary Metal Oxide Semiconductor (CMOS) integrated circuits.
A device in accordance with the present invention comprises a silicon layer resident on a first substrate, a III-V layer resident on a second substrate, the III-V layer being bonded to the silicon layer, wherein the second substrate is removed and the III-V layer and the silicon layer are processed to create the integrated device.
The device further optionally includes semiconductor layer resident on a third substrate, wherein the semiconductor layer is coupled to the III-V layer, the third substrate is removed, and the semiconductor layer, the III-V layer, and the silicon layer are processed to create the integrated device. Devices in accordance with the present invention can take many forms, such as modulators, amplifiers, in-plane or vertical cavity surface emitting lasers, photodetectors, where the device comprises at least one section selected from the group comprising detector pre-amplifier electronics, a laser, drive electronics, memory, and processing circuits, a silicon transponder, a silicon wavelength converter, a silicon tunable laser, a channel selector, and an optical buffer memory.
Another optical lasing device in accordance with the present invention comprises a silicon substrate, an oxide layer coupled to the substrate, a semiconductor layer, coupled to the oxide layer, wherein at least one waveguide is formed within the semiconductor layer, a spacer layer coupled to the semiconductor layer at an interface, a compound semiconductor layer, coupled to the semiconductor layer, and a bulk semiconductor layer, coupled to the compound semiconductor layer; wherein the compound semiconductor layer comprises at least one Quantum Well (QW) layer optically coupled to the at least one waveguide in an evanescent manner, and the spacer layer is bonded to the semiconductor layer.
Such an optical lasing device further optionally comprises the compound semiconductor layer further comprising at least one Separated Confinement Heterostructure (SCH) layer, the bulk semiconductor layer comprising a grating, the oxide layer further comprises a grating, and the at least one waveguide comprises a material selected from the group comprising air, silicon oxide, silicon oxynitride, and silicon nitride.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
FIG. 1 is a side view of a photonic integrated circuit in accordance with the present invention;
FIG. 2 illustrates a cross-sectional view of the offset quantum well gain region in accordance with the present invention;
FIG. 3 illustrates another view of the quantum well region shown in FIG. 2 in accordance with the present invention;
FIG. 4 illustrates the confinement factor versus the width and height of the silicon core in accordance with the present invention;
FIG. 5 illustrates a device manufactured in accordance with the present invention;
FIG. 6 illustrates a processed chip with different devices on a single wafer in accordance with the present invention;
FIG. 7 illustrates a silicon transponder in accordance with the present invention;
FIG. 8 illustrates a silicon wavelength converter in accordance with the present invention;
FIG. 9 illustrates a silicon tunable laser in accordance with the present invention;
FIG. 10 illustrates a channel selector/WDM modulator structure in accordance with the present invention;
FIG. 11 illustrates an optical buffer memory structure in accordance with the present invention; and
FIG. 12 illustrates an integrated silicon transmitter photonics chip in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, reference is made to the accompanying drawings which form a part hereof, and which is shown, by way of illustration, several embodiments of the present invention. Ins understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
Overview
FIG. 1 is a side view of a photonic integrated circuit in accordance with the present invention.
Device 100 is shown, with wafer 102 , film 103 , waveguide layer 104 , modulator/mode converter 106 , gain region 108 , and photodetector 110 as shown. DBR reflector 112 are also shown.
Wafer 102 is typically a silicon CMOS wafer, but can be other materials, such as glass, as desired. Film 103 is typically silicon oxide, but can also be a nitride or silicon oxynitride if desired without departing from the scope of the present invention. Waveguide layer 104 is on film 103 , and is the silicon waveguide layer for device 100 . Modulator/mode converter 106 , tunable laser 108 , photodetector 110 , and rib waveguides 112 are typically Indium Gallium Arsenide Phosphide (InGaAsP), but can be other materials, such as GaInAsN, or other III-V materials, without departing from the scope of the present invention.
A thin film of InGaAsP is deposited on a Semiconductor-On-Insulator (SOI) waveguide. This allows for evanescent coupling of the light in the SOI waveguide 104 to the quantum wells in the III-V material 108 . DBR reflectors 112 are patterned for reflection within the waveguide.
Lateral Structure
FIG. 2 illustrates a cross-sectional view of the offset quantum well gain region in accordance with the present invention.
Device 200 comprises wafer 202 , oxide layer 204 , semiconductor layer 206 , and spacer layer 208 , which is bonded to semiconductor layer 206 at bonding interface 210 . Within semiconductor layer 206 resides gaps 212 , typically air gaps 212 . On spacer layer 208 resides the quantum structure 214 , and then bulk semiconductor layer 216 . Contact 218 and contacts 220 are also shown.
Typically, wafer 202 is a silicon substrate, oxide layer 204 is silicon oxide, and semiconductor layer 206 is silicon, which together comprise a SOI structure. Gaps 212 form the sides of SOI waveguides. Gaps 212 (also known as cladding) can be air gaps, as well as refilled silicon oxide, silicon oxynitride, or silicon nitride, or other materials, without departing from the scope of the present invention. Further, the shape of gaps 212 , when viewed from the top, can be linear, or in a circular or ring shape, or in other shapes, without departing from the scope of the present invention.
Spacer layer 208 is a semiconductor material, typically a III-V material, typically Indium Phosphide (InP), but can be other compound semiconductor materials if desired. The compound semiconductor layer 214 typically comprises a Multiple Quantum Well (MQW) layer and Separated Confinement Heterostructure (SCH) layers, as described in FIG. 3 . Bulk semiconductor layer 216 is also typically InP, but can be other semiconductor materials, typically III-V semiconductor materials, without departing from the scope of the present invention.
Spacer layer 208 is typically bonded to semiconductor layer 206 at interface 210 . The bonding technique used is described in the art, in, e.g., U.S. Pat. Nos. 6,074,892, 6,147,391, 6,130,441, and 6,465,803, which are incorporated by reference herein, and further described in the appendices attached to the present invention, which are incorporated by reference herein. Additional bonding to create additional layers are also possible within the scope of the present invention, which would create additional interfaces 210 within device 200 .
Layer 216 may also comprise a grating which would create a distributed feedback laser within device 200 , a grating in the oxide layer 204 to create a distributed Bragg reflector (DBR) laser, or other layers or components to create other optical lasing devices without departing from the scope of the present invention.
FIG. 3 illustrates a detailed view of the quantum well region shown in FIG. 2 in accordance with the present invention.
Compound semiconductor region 214 comprises an SCH layer 300 , a MQW layer 302 , and an SCH layer 304 . Typically, three to five quantum well layers are present in MQW layer 302 , but a larger or smaller number of quantum well layers or bulk layers can be present without departing from the scope of the present invention. Further, the core portion of semiconductor layer 206 has a height 306 and a width 308 , which dimensions determine the confinement factor of the device 200 . Further, the thickness of each of the layers in the MQW layer 302 also play a part in the confinement factor for a device 200 made in accordance with the present invention.
Confinement Factor
FIG. 4 illustrates the confinement factor versus the width and height of the silicon core in accordance with the present invention.
The graph of FIG. 4 shows the confinement factor 400 versus the width 308 , shown on y-axis 402 , of the silicon core portion of semiconductor layer 206 . For a range of heights 306 , the confinement factor of the silicon core, shown as lines 404 , and for a range range of heights 306 , the confinement factor 400 of the multiple quantum well region varies as a monotonic function of width 402 . As the height of the core gets higher, the confinement factor 400 within the waveguide goes up; as the height of the core goes up, the confinement factor in the MQW layers 406 goes down.
Fabrication and Integration of Separate Devices
Typically, a chip-level bonding approach is used to bond one type of material to another. The chip-level bonding approach works well for discrete devices, however, alignment is typically an issue. There are some devices, such as integrated optical amplifiers, that are difficult to fabricate using a chip-level approach because of reflections at the interface between the III-V layer and the silicon substrate.
However, the present invention contemplates using a wafer-level bonding approach, where a III-V wafer is bonded to a silicon wafer, the III-V substrate is removed, and the III-V layers are then processed into various types of devices.
FIG. 5 illustrates a device manufactured in accordance with the present invention.
FIG. 5 illustrates a SiO2/Si Distributed Bragg Reflector (DBR) bonded to AlGaInAs quantum wells for a Vertical Cavity Surface Emitting Laser (VCSEL).
FIG. 6 illustrates a processed chip with different devices on a single wafer in accordance with the present invention.
As shown in FIG. 6 , many different types of devices can be integrated on a single wafer or chip using the process of the present invention. For example, detector pre-amplifier electronics, the detector array, a laser or modulator, drive electronics, and memory/processing circuits can now all reside on a single piece of semiconductor substrate, because the qualities of the silicon that are desirable, e.g., avalanche gain, is now electrically bonded to a material that is a better absorber than silicon.
FIG. 7 illustrates a silicon transponder in accordance with the present invention.
As shown in FIG. 7 , where the III-V material is better suited to perform a specific circuit task, the material is used in that location on the circuit to provide that function. For example, and not by way of limitation, silicon is used in the multiplexer and driver electronics, but the III-V material is used in the gain portion of the tunable DBR laser and the phase modulator portions of the transponder. Such an approach allows for integration of the entire circuit, rather than fiber coupled die or using printed circuit boards, ball grid arrays, or other approaches to integrate the various components of the transponder.
FIG. 8 illustrates a silicon wavelength converter in accordance with the present invention. Again, the tunable laser and the SOA use III-V materials, whereas the silicon is used for the VLSI driver electronics, which provides an integrated device on a single semiconductor surface rather than using components to create the wavelength converter device.
FIG. 9 illustrates a silicon tunable laser in accordance with the present invention. Again, the III-V material is used for the gain portion of the laser, while silicon is used for the driver electronics.
FIG. 10 illustrates a channel selector/WDM modulator structure in accordance with the present invention.
The channel selector and the SOA use III-V materials, whereas the silicon is used for the VLSI driver electronics, which provides an integrated device on a single semiconductor surface rather than using components.
FIG. 11 illustrates an optical buffer memory structure in accordance with the present invention.
FIG. 12 illustrates an integrated silicon transmitter photonics chip in accordance with the present invention.
Chip 1200 comprises ring lasers 1202 - 1208 , which are evanescent lasers. Each ring laser 1202 - 1208 can produce different wavelengths if desired. Ring lasers 1202 - 1208 have their waveguides resident in chip 1200 , which is typically silicon, and the gain region in the bonded region 1210 , which is typically a III-V material.
Ring lasers 1202 - 1208 are then coupled to SOI waveguides 1212 - 1218 respectively, which are coupled to modulators 1220 - 1226 . Modulators 1220 - 1226 are resident in the chip 1200 , which, again, is typically silicon, but can be other materials without departing from the scope of the present invention.
Modulators 1220 - 1226 are then coupled via SOI waveguides to multiplexer 1228 , which has an output 1230 . Output 1230 comprises a signal which contains all of the wavelengths produced by ring lasers 1202 - 1208 . Additional circuitry can be provided to selectively eliminate one or more of the ring lasers 1202 - 1208 wavelengths from being included in output 1230 .
As seen in FIG. 12 , the evanescent coupling of the present invention can be performed at the wafer level, partial wafer level, or die level, depending on the application or desired device, which provides for selective integration of III-V materials or other materials with a silicon platform.
CONCLUSION
In summary, embodiments of the invention provide methods and for making an optical device on silicon. The present invention can be used for lasers, modulators, amplifiers, and photodetectors, and devices that use combinations of these devices, such as wavelength converters, channel selectors, 3R regenerators, buffer memories, etc.
A device in accordance with the present invention comprises a silicon layer resident on a first substrate, a III-V layer resident on a second substrate, the III-V layer being bonded to the silicon layer, wherein the second substrate is removed and the III-V layer and the silicon layer are processed to create the integrated device.
The device further optionally includes semiconductor layer resident on a third substrate, wherein the semiconductor layer is coupled to the III-V layer, the third substrate is removed, and the semiconductor layer, the III-V layer, and the silicon layer are processed to create the integrated device.
Devices in accordance with the present invention can take many forms, such as a vertical cavity surface emitting laser, a photodetector, where the photodetector comprises at least one section selected from the group comprising detector pre-amplifier electronics, a laser, drive electronics, memory, and processing circuits, a silicon transponder, a silicon wavelength converter, a silicon tunable laser, a channel selector, and an optical buffer memory.
Another optical lasing device in accordance with the present invention comprises a silicon substrate, an oxide layer coupled to the substrate, a semiconductor layer, coupled to the oxide layer, wherein at least one waveguide is formed within the semiconductor layer, a spacer layer coupled to the semiconductor layer at an interface, a compound semiconductor layer, coupled to the semiconductor layer, and a bulk semiconductor layer, coupled to the compound semiconductor layer; wherein the compound semiconductor layer comprises at least one Multiple Quantum Well (MQW) layer optically coupled to the at least one waveguide in an evanescent manner, and the spacer layer is bonded to the semiconductor layer.
Such an optical lasing device further optionally comprises the compound semiconductor layer further comprising at least one Separated Confinement Heterostructure (SCH) layer, the bulk semiconductor layer comprising a grating, the oxide layer further comprises a grating, and the at least one waveguide comprises a material selected from the group comprising air, silicon oxide, silicon oxynitride, and silicon nitride.
The foregoing description of the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but by the claims attached hereto and the full breadth of equivalents to the claims. | Photonic integrated circuits on silicon are disclosed. By bonding a wafer of HI-V material as an active region to silicon and removing the substrate, the lasers, amplifiers, modulators, and other devices can be processed using standard photolithographic techniques on the silicon substrate. The coupling between the silicon waveguide and the III-V gain region allows for integration of low threshold lasers, tunable lasers, and other photonic integrated circuits with Complimentary Metal Oxide Semiconductor (CMOS) integrated circuits. | 8 |
FIELD OF THE INVENTION
[0001] The invention relates generally to a chess game, more specifically to a novel chess game, in particular to a method and device for playing a chess game between two pairs of players.
BACKGROUND OF THE INVENTION
[0002] In a traditional method of playing chess between two players the players alternatively move chess pieces on a game board (playing field) comprising 64 equal squares of alternating light and dark colors. Chess clocks are used to limit the time for thinking over the moves in chess competitions, each of the chess clocks having a timing unit connected to two displays and a control unit. At the start of the game each player has the same number of chess pieces and pawns, one player having light-color (white) pieces and the other player having dark-color (black) pieces. Each set of chess pieces includes: one king, one queen, two rooks, two bishops, two knights and eight pawns. White starts the game; the right to play with white pieces is generally decided by a game of chance. A player must move one piece at a time, with the exception of castling. Omission of moves is prohibited. This combination of chess game features has been retained almost in all variants of improved chess games, because they are substantially aimed at structural embodiments or insignificant modification of chess game rules. Consider three examples of improved chess game variants. A first variant disclosed in U.S. Pat. No. 6,203,016 BA (Cl.7 A63F 3/02, 1999) is a method of playing chess intended to add more interest to the game process owing to insignificant modification in the above rules. The second variant disclosed in U.S. Pat. No. 6,382,626 BA (Cl.7 A63F 3/02, 2000) is a device and method for playing chess, wherein central pawns differ from the other pawns not only in size, but also in a way of moving across the chess board. In a third variant disclosed in U.S. Pat. No. 6,702,287 (Cl.7 A63F 3/02, 1999) a device and method for playing chess use a game board having 110 black and white squares. Similarly to the traditional chess game, at the start of the game the players have equal number of pieces and pawns, one player having light-color pieces, and the other one having dark-color pieces. A feature of this device is that each of the chess sets includes seventeen additional pieces which are not obligatory chess pieces.
[0003] The aforementioned devices and methods of playing chess between two players suffer from low audience appeal associated with the lack of team contest. This is explained by the fact that the current chess game process is mathematically formalized to a great extent, i.e. it is practically devoid of “mystery”. To put it differently, the current chess game is reduced to a contest between two players who only repeat, in the best case, computer-predicted chess moves at critical moments of the game. That is why a team game in which a single chess game is played between two teams, each consisting of a plurality of players, is of main interest for chess fans. Rather many attempts to overcome this problem have been made for the moment. By way of example, in U.S. Pat. No. 5,586,762 (Cl.6 A63 F 3/02, 1994) four sets of chess pieces are used for a chess game played between several teams at a time, each of said sets being provided with marks distinguishing pieces of one group from pieces of the other groups; and a square game board comprises a central matrix of sixty-four squares and four side regions, each including sixteen squares. Players alternatively move a piece according to the standard rules of chess, attempting to advance pawns to the edge rows of the squares in the central matrix. U.S. Pat. No. 6,260,848 BA (Cl.7 A63F 3/02, 2000) describes a device for playing chess between four players, comprising a game board of 144 squares of two alternating colors. In some prior art devices adapted for playing a game between more than two players, several game boards are used. For example, WO 38805 A1 (Cl.7 A63F 3/02, 1999) discloses a device for playing chess which differs from the traditional game in that three or four players play on three or four game boards at the same time. However, the aforementioned and other known methods of playing a chess game between two teams suffer from low entertaining appeal. This is primarily explained by the fact that players members of the same team can cooperate and this excludes the basic feature of pair game—the need of taking an independent decision by each player in the pair at a respective time in the game. Other deficiencies of traditional systems will be discussed in the following description. In light of the aforementioned, the object of the invention is to overcome the shortcomings mentioned above.
SUMMARY OF THE INVENTION
[0004] The object of the present invention is to provide a method of playing a chess game which can be played by at least two pairs of players, and a device for carrying out the method.
[0005] The object is attained in a device for playing a chess game comprising: at least two playing fields which are divided into squares of two alternating colors; two sets of chess pieces, each set consisting of two groups of chess pieces; and two chess clocks, each chess clock including a timing unit connected to two displays and to a control unit; said device for playing a chess game further comprises means for exchanging data related to positions of chess pieces on the playing fields, and each chess clock comprises a device for locking the control unit, wherein all timing units of the chess clocks are linked together.
[0006] The above device can be used to implement a method of playing a chess game including alternatively moving, by players, members of a first or second team, a chess piece on a playing field during a time limit allotted to each player, said method further comprising: using in said set of chess means respective locking devices, e.g. a device for locking the switching of a chess clock by a player; setting a time limit for the first and second team, and setting the turn of moves of a chess piece by players by locking access to a predetermined chess means at a respective time.
[0007] A distinctive feature of the present invention is a chess computer included as at least one player in a first or second team. Other features and advantages of the invention will become apparent from the following detailed description, as well as from claims 1 to 16 .
BRIEF DESCRIPTION OF DRAWINGS
[0008] The invention will be further explained with reference being made to the attached drawings wherein:
[0009] FIG. 1 is a general plan view of a chess table;
[0010] FIG. 2 is a schematic diagram of a device for playing a chess game between two pairs of players in a first embodiment;
[0011] FIG. 3 is a schematic diagram of a piece position sensor;
[0012] FIG. 4 is a first embodiment of circuitry of two chess clocks;
[0013] FIG. 5 is a second embodiment of circuitry of two chess clocks;
[0014] FIG. 6 is a circuit showing how chess clocks are connected to a piece position sensor;
[0015] FIG. 7 is a schematic diagram of a device for playing a chess game between two pairs of players in a second embodiment;
[0016] FIG. 8 is a schematic diagram of a device for playing a chess game between two pairs of players in a third embodiment;
[0017] FIG. 9 is a schematic diagram of a device for playing a chess game between two teams, each team including a chess computer as a player;
[0018] FIG. 10 is a schematic diagram of a device for playing a chess game between two pairs of players, wherein one of the players in each team is a chess computer;
[0019] FIG. 11 is a general view of portable devices for playing chess between two pairs of players;
[0020] FIG. 12 is a flow diagram illustrating an algorithm of playing a chess game.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] In further description of the preferred embodiments of the invention, the underlined terms will be replaced with abbreviations shown in brackets. FIG. 1 shows a chess table (CT) 1 on which chess clocks (CC) 2 having two displays: a display (DIS) 3 and DIS 4 are arranged; a count down process at DIS 3 is started by pressing a button 5 , and a count down process at DIS 4 is started by pressing a button 6 . At the count down start at DIS 3 , DIS 4 registers the time accumulated during the game, and vice versa, at the count down start at DIS 4 , DIS 3 registers the time accumulated during the game. Depicted on the chess table 1 is a playing field (PF) 7 , a square field divided into squares of two alternating colors. Light-color squares are referred to as white fields, and dark-color squares are referred to as black fields. The set of chess pieces includes two groups of chess pieces. A first group 8 includes light-color (white) pieces, and a second group 9 includes dark-color (black) pieces. Each group of chess pieces includes: a king 10 , a queen 11 , two rooks 12 , two bishops 13 , two knights 14 and eight pawns 15 . In addition to PF 7 , two fields 16 and 17 can be depicted on the CT 1 , comprising conventional signs used to designate each field, e.g. when recording separate game moves. According to the rules of algebraic chess notation, the field 16 comprises letters of Latin alphabet (from “a” to “h”), and the field 17 comprises ciphers (from “1” to “8”). In addition, each chess piece has its letter notion: King K, Queen Q, rook R, bishop B, knight N; notation p for pawns is used only to record positions, and omitted in records of the game. To indicate white and black fields, light-emitting diodes 18 are provided on the surface of the CT 1 in parallel with the fields 16 and 17 . FIG. 2 shows a general view of a device for playing a chess game between two pairs of players at two CTs 1 . A first player (FP A ) 19 and a second player (SP A ) 20 are members of a first team (team A); a first player (FP B ) 21 and a second player (SP B ) 22 are members of a second team (team B); communication between players in each team is prohibited. A feature of the device is that the CCs 2 located on two CTs 1 communicate through various communication means described below. To transmit information about a move that was made, each player can use data exchange means (DEM) adapted to exchange data, between players 19 , 20 , about positions of chess pieces 10 , 11 , 12 , 13 , 14 , 15 on the playing fields 7 . In the present case, one of the DEMs comprises two linked digital displays (DDIS) to show the position of a chess piece, in particular, a first DDIS 1 23 and second DDIS 2 24 . DDIS 1 23 and DDIS 2 24 communicate via a link 25 . Another DEM, comprising a third DDIS 3 26 and a forth DDIS 4 27 communicating via a link 28 , serves to exchange chess moves between FP B 21 and SP B 22 . Piece position information may be entered in a respective DDIS either automatically or by a player entering a respective algebraic chess notation with the aid of an input device. It should be noted that a variety of electronic devices that can be used as DEM are commercially available. They include, in particular, a mobile telephone (MT) and pocket personal computer (PPC). PPC can be also referred to as a personal digital assistant, palm personal computer, portable computer. Consider a peculiarity of using the latter in the DEM. An input device in the PPC relies either on its keys or on the screen with a special sensitive layer and a protective film applied thereon. A player may enter piece position information by writing a chess notation on the screen. A dedicated software installed in the PPC recognizes the handwritten letters and digits and then sends them to another PPC via link 25 or 28 . A plastic stylus is used to write text data and operate on the PPC screen by touching the screen surface (which is pressure sensitive). If both PPCs have an IR-port, Bluetooth or Wi-Fi module, links (channels) 25 , 28 between them can be wireless. DEM can be also a pen with a miniature TV camera connected to a means for recognition letters or digits written on paper. If no means of such kind is available, a digital pen, PC Notes Taker, can be used to enter graphic information or hand-written text in a computer. The main feature of this embodiment is that a player writes with the digital pen on a plain paper, and the exact copy of the record appears immediately on the screen of an appropriate PPC 23 , 24 , 26 , 27 . This result is provided by the fact that the pen sends an IR signal to a receiver integrated in a base unit. The base unit is a detachable device comprising an IR receiver, which is attached to the piece of paper. DEM can be also one or more display boards 29 connected to the PF 7 and comprising a piece position sensor_(PPS). If two PFs 7 are used, a link 30 should be provided between them. FIG. 3 shows an embodiment of PPS 31 circuitry. The PPS 31 includes a microcomputer (MC) 32 and a comparator module (CM) 33 comprising sixty four voltage comparators. The microcomputer 32 operates on digital data encoded as zeroes and ones at the output of the CM 33 . Analog part of the PPS 31 comprises sixty four pairs of conductive plates 34 , 35 overlying each of the white and black fields of the PF 7 . Plates 35 are connected to output of a generator 36 , while each of the plates 34 is connected to a respective input of the voltage comparator included in the CM 33 . Furthermore, light-emitting diodes 18 and a wireless adapter (WLA 1 ) 37 that replaces the wire link 30 by a wireless one are connected to output of the MC 32 . The wireless adapter includes a transceiver coupled to an output of the MC 32 via a digital modulator and to an input of the MC 32 via a clocking unit. The latter is used to recover digital data present at the output of the MC 32 at the instant of transmission thereof to another PF(s) 7 . It should be noted that the transceiver may be a standard Bluetooth 1.1. device, such as D-Link DBT-900AP. The generator 36 of the microcomputer 32 and CM 33 are supplied from own power supply (PS). For normal functioning of the PPS 31 , the lower part 38 of chess pieces must be conductive. PPS 31 operates in the following manner. Initially, the MC 32 stores original positions of chess pieces. After each move of a piece discrete signals appear at output of a respective comparator, and MC 32 determines from them a new position of the piece on the PF 7 . All the moves of chess pieces on a PF 7 are accompanied by generation in the MC 32 of signals which are transmitted via WLA 1 37 to another PFs 7 . After each change in a chess piece position on the PF 7 two light-emitting diodes (LED) 18 light, one of the LEDs being in the vicinity of the field 16 , and the other one in the vicinity of the field 17 . The LEDs light on several PFs 7 at once, the mode of LED activation being specified by the MC 32 software. Generation of a discrete signal at the comparator's output is caused by a change in the variable voltage at its input after a piece move. Each move of a chess piece alters the capacitance between plates 34 , 35 , hence the value of the variable voltage part output from the generator 36 to the input of a respective comparator changes as well. Response voltage of comparators in the CM 33 is chosen such that in case of appearance of a chess piece, a discrete signal corresponding to logical one appears at the respective comparator output. The capacitance C N between plates 34 , 35 changes when a chess piece is present owing to the additional parallel connection to C N of two series-connected capacities C F 1 and C F 2 , where C F 1 is the capacity whose plates are plate 34 and the lower part 38 , and C F 2 is the capacity whose plates are plate 35 and the lower part 38 . FIG. 4 shows two circuits of CCs 2 for generating all electric signals required for operation of the CCs 2 . Each circuit includes: a timing unit (TU) 39 coupled to a displaying module 40 comprising two displays: DIS 3 and DIS 4 , and to a control unit (CU) 41 . The latter comprises (initially) open contacts 42 , 43 coupled to buttons 5 , 6 . Operation parameters of CC 2 , e.g. time limit T C , are set by closing contacts 44 . The TU 39 includes two counters for accumulating the game time, the counters being connected to a common pulse generator whose frequency is set by a quartz resonator 45 . It should be noted that the timing unit 39 can be a timing microprocessor (TMP), such as SMC 6280 available from Seiko Epson. In this case the TU 39 operation algorithm is stored in the TMP memory in its manufacture. In addition to the aforementioned components, CC 2 comprises a locking device (LD) 46 for locking the control unit 41 . The locking device 46 comprises a trigger 47 and two logical coincidence circuits (LCC) 48 , 49 , the upper input of the LCC 48 on the circuit being a control input of the LD 46 . It is seen from the drawing that in this embodiment of the CC 2 , TUs 39 are linked together via the LD 46 . The circuit further comprises LED 50 and LED 51 . The former is to indicate activation of DIS 3 , and the latter is to indicate activation of DIS 4 . CC 2 is supplied from a battery 52 . FIG. 5 shows a second embodiment of CC 2 . In this embodiment LD 46 is implemented in the TU 39 software and includes an input/output device (I/O) connected via a bus 53 to a wireless adapter (WLA 2 ) 54 whose parameters are matched with that of WLA 2 54 of the other CC 2 . Thus, I/Os of TUs 39 , such as TMP, are linked together via wireless link 55 . The CC further includes additional LEDs 56 , 57 to indicate activation of the LD 46 . FIG. 6 shows an embodiment of a chess clock wherein WLA 2 54 is matched with WLA 1 37 included in one or more PPS 31 . Such connection enables locking an appropriate button 5 , 6 of the CC 2 when a player in one team erroneously repeats a move on his PF 7 . This event can be indicated by one of LEDs 56 , 57 . Another possible function of LEDs 56 , 57 is to indicate locking activation mode, in which mode the depression of e.g. the button 5 when LED 57 is activated will not result in switching the CC 2 . FIG. 7 shows a device for playing a chess game between two pairs of players, wherein playing fields and chess clocks are implemented in the following service computers (SC): SC 1 58 , SC 2 59 , SC 3 60 , SC 4 61 . Each of the SCs comprises: a virtual playing field (VPF) generation unit 62 , a virtual chess piece (VCP) set generation unit and a virtual chess clock (VCC) generation unit 63 . These units generate, on a display of each SC, a set of chess means in the form of a VPF 62 with VCPs and VCCs 63 located thereon. It should be noted that one of the SCs or PPS 31 may comprise a LD for locking a piece move on the PF 7 or VPF 62 , such as a DEM locking unit for locking DEM related to positions of chess pieces on the PF 7 or VPF 62 . To exchange data, SCs 58 , 59 , 60 , 61 are linked together through a network channel, such as Ethernet or local wireless network. In the former case, SCs 58 , 59 , 60 , 61 can be linked together using adapters, T-connectors and a hub 64 . It should be noted that the local network can be a computer network concentrated in a single building, the residence of the World Chess Federation (FIDE). If SCs 58 , 59 , 60 , 61 are linked by the Internet 65 ( FIG. 8 ), they can be generally located at any point on the Earth. In conclusion it may be said that if every SC includes means for locking a piece move on the VPF 62 , the control inputs thereof are also linked via a hub 64 or the Internet 65 . FIG. 9 shows a device for playing a chess game between two teams, each team including three players, wherein one the players in each team is a chess game computer (CGC). Therefore, a first team (team A) includes a first player (FP A ) 19 , a second player (SP A ) 20 and a third player (TP A ) such as a first chess game computer (CGC 1 ) 66 , and a second team (team B) includes a first player (FP B ) 21 , a second player (SP B ) 22 and a third player (TP B ) such as a second chess game computer (CGC 2 ) 67 . To exchange data between SC 1 58 , SC 2 59 , SC 3 60 , SC 4 61 , internal wireless adapters such as D-Link DW L-G520 are used, operating at frequencies in the range from 2.4 GHz to 2.483 GHz and having an external antenna 68 . Chess game computers CGC 1 66 and CGC 2 77 are, in turn, connected to an external wireless adapter 69 such as Eline ELW-9610SXg-Wireless LAN Broadband Router 9610SX-g54M having an external antenna 70 . FIG. 10 shows a device for playing a chess game between two teams, each including two players, wherein one of the players in each team is own personal CGC connected to MC 32 included in PPS 31 . The latter comprises in particular a PF 7 . Therefore, team A includes a first player FP A 19 and second player, CGC 1 66 , and the team B includes a first player FP B 21 and second player, CGC 2 67 . FIG. 11 shows two portable devices (PD) 71 for playing a chess game, that are linked via a wireless link 72 including removable external antennas 73 . The portable devices 71 are designed for playing chess between at least two pairs of players. In addition to the removable external dipole antenna 73 , the portable device 71 also comprises an internal antenna. Portable devices 71 for playing chess are designed for amateur chess players and for secondary schools as an effective chess game tutorial and means for improving intelligence level of students. The device comprises a PPS, an electronic CC 2 having DIS 3 and DIS 4 , and LEDs 50 , 51 , 56 , 57 . A basic feature distinguishing the device from that shown in FIG. 1 is that PPS 31 , CC 2 , PF 7 , MC 32 and WLA 1 37 are all integrated in a single housing. Another distinctive feature of PD 71 is an additional row of LEDs 18 replacing the field 16 . PD 71 further comprises internal wireless adapters operating under the conventional Bluetooth or Wi-Fi standard. Both standards generate electromagnetic radiant flux at a frequency within the range from 2.4 to 2.48 GHz. The term “Wi-Fi” refers to a variety of wireless local network standards. The internal wireless adapters and link 72 enable communication between means included in the PD 71 , such as PPS 31 and CC 2 . In an embodiment of PD 71 , the integrated MC 32 can perform the functions of not only PPS, but also of TU 39 . In this case all of the aforementioned locking devices can be implemented in the MC 32 software. Here, the turn of moves of chess pieces 8 , 9 by players is specified by a special service routine stored in memory of MC 32 and matched with a service routine of another PD 71 . A device for playing a chess game operates in accordance with an algorithm shown in FIG. 12 . The algorithm can be practiced using a dedicated and standard software stored in read-only memories of the following means: 2 , 23 , 24 , 26 , 27 , 32 , 39 , 58 , 59 , 60 , 61 , 66 , 67 , 71 . The device for playing chess starts its operation after step 74 of generating a turn N(N=1, 2, . . . ) of plies to be made by players. The term “ply” (or half a move) refers to N-th move made by one party only. To simplify the following description the following notations will be used: N W is a ply made by white pieces, and NB is a ply made by black pieces. A ply turn routine can be also stored in read-only memories of the following means: 2 , 23 , 24 , 26 , 27 , 32 , 39 , 58 , 59 , 60 , 61 , 66 , 67 , 71 . Saying it differently, the turn of moving pieces by players is specified by storing a service routine in a memory of a respective chess means. The turn of plies N w , N b is determined beforehand in accordance with the rules set for given chess game. Consider possible variants of the turn of plies in a chess game between two teams, each team including two players, i.e. a team A (white pieces) includes players FP A 19 and SP A 20 , and a second team B (black pieces) includes FP B 21 and SP B 22 . From here on, the turn of N-th ply for given player will be indicated in brackets, i.e. record SP A (2N w ) means that a player SP A with white pieces must make all even plies N w : N w =2, 4, . . . N w E , where N w E is the last ply with white pieces in the game. It should be noted that the turn of moves can be generally specified using not only a deterministic law, but a random law either. The latter may include such factors as player's rating “r”; number k (k=2, 3, . . . ) of players in a team; total running time t spent by a player during the game, etc. In the latter case, the record may be: SP A (N w =F(t,k,r)), where F(t,k,r) is the probability that the right to ply will be given to the player SP A having rating “r”. It is evident that the choice of the function type may influence the strategy of cooperation between the players in the same team. For example, if probability F(t,k,r) increases with reduction in t value, to obtain preference in the pair game a player with a higher rating must play faster than his partner in the team. The invention will be further described with reference to a device for playing a chess game between two teams, a first team including players FP A 19 and SP A 20 , and a second team including players FP B 21 and SP B 22 . The turn of plies will be as follows: FP A (2N w −1), SP A (2N w ), FP B (2N b −1), SP B (2N b ). With a device having the structure shown in FIG. 2 , after a time limit T 0 has been set by closing contacts 44 on both CCs 2 and with the CCs running (step 75 ), count down starts simultaneously at two CCs 2 (step 76 ). The count down at CCs 2 can be synchronized by various methods, e.g. using a single master oscillator that provides pulses to the other CCs 2 via a wireless link 55 . In another embodiment master oscillators included in MC 32 can be symphonized via this link. At both CCs 2 the count down of accumulated time T after activation (step 76 ) terminates at DIS 3 after duplicating on both PFs 7 the chess move and pressing button 6 at both CCs 2 . At the instant of count down completion, DIS 3 registers value (T 0 −t*), where t* is the time spent for one move, then count down starts at DIS 4 . It terminates after pressing buttons 5 (not obligatory at the same time). Thus, after specifying the above turn of moving chess pieces 10 , 11 , 12 , 13 , 14 , 15 by players FP A , SP A , FP B , SP B , the device will function in the following manner. Assume that the game is played on two PDs 71 , wherein FP A , FP B play at a first PD (PD 1 ), and SP A , SP B play at a second PD (PD 2 ). Assume further that the player FP A 19 gets the right to 9-th ply during the game; at this instant his DIS 3 reads: 17 min 42 sec, LED 57 at PD 2 and LEDs 56 , 57 at PD 2 are activated, i.e. light. Lighting of the LEDs means that button 5 at PD 1 and buttons 5 , 6 at PD 2 are locked, i.e. depression of the buttons will not result in switching the CC. Then according to the specified turn the player FP A makes 8-th ply with white knight (N w =9) “9.Nc3-e2” and presses the button 6 of the CC 2 (“Yes” at step 78 ); at the instant of this depression DISs 3 of both CCs 2 read: 14 min 36 sec. After transmission of the ninth ply via link 72 and respective activations of LED 18 at PD 2 the player SP A repeats the ply “9. Nc3-e2” at his PD 2 and then presses button 6 of his CC 2 (“Yes” at step 79 ). Only after this event both CCs 2 switch simultaneously (step 81 ) i.e. the right to ply N b =9 passes to the player FP B (step 81 ). Note that immediately after repeating the 9-th ply by the player SP A LED 56 at PD 2 goes out, and after pressing the button 6 it lights again. As mentioned above, in case of incorrect repetition of the ply, LED 56 will remain activated, and both CCs 2 will remain in the original count down state at DIS 3 despite the depression of the button 6 at PD 2 by SP A . Due to a delay τ (τ>0) in the repetition of 9-th ply by the player SP A , at the instant of his depression of the button 6 DISs 3 of both CCs 2 read: 14 min 35 sec (τ=1 sec), i.e. emphasize again that count down of time t* of one ply for team A is not over until the player SP A repeatedly presses the button 6 . Then, according to the specified turn the player FP B gets the right to make 9-th ply with a black piece; at this instant DIS 4 reads: 18 min 14 sec; LED 57 is disabled (the other LED 57 and two LEDs 56 are activated). After making the ply with a black pawn “9 . . . e7-e5”, the player FP B shortly presses the button 5 of the CC 2 (“Yes” at step 78 ); at this instant DISs 4 of both CCs 2 read: 17 min 7 sec, i.e. the FP 2 spent 1 min 7 sec for thinking over the move. After transmitting the 9-th ply via link 72 , the SP B repeats the ply “9 . . . e7-e5” on his PD 2 and then presses the button 5 of his CC 2 . Only then both CCs 2 switch simultaneously (step 79 ), i.e. the right to make 10-th ply (N w =10) after disabling the LED 57 at PD 2 passes to the player SP A (step 81 ). Due to a delay in repetition of 9-th ply by the player SP B at the instant of his short-time depression of the button 5 DISs 4 of both CCs 2 read: 17 min 5 sec (τ=2 sec). The aforementioned steps are then repeated in respect of 10-th ply “10.c2-c3” with the only difference that the ply is made by the player SP A , and the player FP A repeats the ply. The same steps are also repeated in respect of 10-th ply with a black piece (N w =10) “10 . . . Kb8-c6”, i.e. the player SP B makes the ply and player FP B repeats the ply. After expiration of the time limit T 0 (T 0 =0) at one of the time limit displays (“Yes” at step 77 ), the game terminates (step 82 ). Note that the functions of LEDs 56 , 57 can be performed by LEDs 50 , 51 , e.g. by intermittently lighting to indicate the locking mode. Now consider some structural features of technical means used to implement steps 78 , 79 and step 81 . Step 81 is implemented on the basis of a device for locking the switching of the CC 2 included therein. In the simplest case this device is used to lock the CC switching when the switching has been made by a single player only. The locking device can be implemented either in software ( FIG. 5-FIG . 11 ) or hardware. FIG. 4 shows a CC comprising a hardware LD 46 . Its operation will be described on the example of the above algorithm of playing a chess game between two pairs of players. Assume that TU 39 generates signals of count down of accumulated time T at DIS 3 or DIS 4 only when logical one is present at input A 1 or A 2 of the TU 39 , and logical zero is simultaneously present at the other input A 2 or A 1 , respectively; the CCs retain the running time T count down mode at DIS 3 or DIS 4 in case of conversion of logical one to logical zero. The order of CC activation is determined by internal program in the TU 39 . Assume that in the original state before 9-th ply output Q of the trigger 47 in both clocks has a voltage corresponding to logical one (log.“1”), i.e. log.“1” and log.“0” are applied to inputs A 1 and A 2 (LED 50 and DIS 3 are activated). Then, after a short-time depression by the player FP 1 on the button 6 of the CC (“Yes” at step 78 ) contacts 43 at his CC close, this resulting in log.“0” appearing at output Q of the trigger 47 . It is evident from the schematic diagram that only after pressing the button 6 of the second CC 2 DIS 4 will be activated and DIS 3 will be disabled on both CCs. Actually, in this case log.“1” appears at input A 2 of the TU 39 of both CCs (at this instant log.“0” is present at two inputs A 1 ), which is the necessary condition for switching the VCC 63 . Using the circuits shown in FIGS. 7 to 11 , the VCC 63 will be automatically switched immediately after a chess move, e.g. using a mouse pointing device. In this case the turn of moving, by players FP 1 19 , SP, 20 and FP 2 21 , SP 2 22 , chess pieces on respective SC 1 58 , SC 1 59 , SC 1 60 , SC 1 61 is specified by locking a respective input device, such as a keyboard or a mouse pointing device. With the circuits shown in FIGS. 7 to 11 , delay τ in switching the VCC 63 will be generally determined by the time of propagation of a respective signal between service computers and chess game computers SC 1 58 , SC 1 59 , SC 1 60 , SC 1 61 , CGC 1 66 and CGC 2 67 , and the time of processing the signal. In conclusion it may be said that various embodiments of portable device 71 for playing chess are possible. In one of the variants buttons 5 , 6 for switching the CC 2 can be omitted, the switching being performed automatically, but only if steps 78 , 79 (making i-th ply by a player of team A or B in accordance with the specified turn (step 78 ) and its repetition (step 79 ) by a second player of team A (B) at the other portable device 71 ) have been executed. As this takes place, microcomputers of portable devices 71 functioning as e.g. PPS 31 , TU 39 , control unit 41 and devices for locking them must be in the mode of active communication via wireless link 72 .
INDUSTRIAL APPLICABILITY
[0022] The invention can be used for organization of a world championship under the aegis of FIDE in pair category. High competition among computer companies for participation in this kind of chess games is explained by the fact that a variant of the game can be conducted not only between the pairs including two human players, but also between the pairs, each including a human player and a computer. In the latter case the human player may preliminary “train” his “partner”. Methods and means of such “training” may be used in manufacture of common computers. The invention can be used as a tutorial instead of the ordinary chess recommended by UNESCO to be used in schools worldwide. The invention can be also used in organization of mass production of portable devices for playing chess between at least two pairs of players. | The invention relates to chess game playing method, in particular to a novel type of a chess game between two pairs of players. The inventive chess game playing device comprises at least two playing fields ( 7 ) which are divided into squares of two alternating colours, two sets of chess pieces, each of which consists of two groups ( 8, 9 ) of chess pieces ( 10 - 15 ) and two chess-clocks ( 2 ) each of which is provided with a timer ( 39 ) connected to two displays ( 3, 4 ) and to a control unit ( 41 ) which is used for switching said displays ( 3, 4 ). The chess game playing device also comprises means for exchanging data related to the location of the chess pieces ( 10 - 15 ) on the playing fields ( 7 ), each chess-clock ( 2 ) comprises a device for locking the control unit ( 41 ), wherein all timers ( 39 ) are interconnected. | 0 |
The invention described was made in the course of or under a contract or a subcontract thereunder with the Department of the Army.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to electromagnetic wave filters employing thin film ferrite resonators and more particularly pertains to filters employing resonators having an essentially fixed resonant frequency.
2. Description of the Prior Art
At the lower microwave frequencies, cavity resonators compatible with conventional waveguides are well known for their fixed frequency operation. However, as the desired frequency of operation approaches the higher frequencies of the microwave band and still higher, the millimeter wavelength band, viz., from 24 to 300 GHz, cavity resonators are required to be very small. This small size makes the machining and fabrication of cavity resonators difficult and costly. These same considerations apply to the application of conventional waveguides to operation at the higher frequencies.
Microstrip and strip-line transmission lines and other components, including resonators, fabricated on dielectric substrates using photolithographic techniques have been used successfully at the higher microwave frequencies. However, these components tend to be relatively lossy. Therefore, resonators of this type have a relatively lower Q and, consequently, broader bandwidth then is frequently desired.
Ferrites have found broad application in microwave technology. Where a body of a ferrite material is employed as a resonator, the electromagnetic energy usually is coupled through the body by uniform spin precession about the magnetic field intensity vector in the ferrimagnetic material. The resonant frequency of such a resonator is the natural precession frequency of a magnetic dipole in the material subjected to a constant magnetic field. The natural precession frequency is a direct function of the intensity of the applied magnetic field, and of the magnetic anisotropy and saturation magnetization of the material.
Relatively high Q, narrow bandwidth resonators have been fabricated using spheres or slabs cut from single crystals of a ferrite such as, for example, yttrium iron garnet (YIG). Crystalline YIG has a cubic lattice structure. YIG resonators have been operated in their uniform spin precession resonance mode at the lower microwave frequencies. Establishing a resonance in this same mode at higher frequencies, however, requires higher applied magnetic field intensities than can be conveniently provided.
Although very high applied magnetic field intensities can be established with electromagnets having supercooled coils, the use of such electromagnets is not regarded as practical for most applications.
Resonators which depend upon the intensity of an applied magnetic field to establish their frequency of resonance, as do these prior-art resonators, suffer from an additional handicap. The resonant frequency will change or drift as the intensity of the applied magnetic field changes due to such factors as, for example, temperature variations.
Thin films of monocrystalline YIG have been deposited on single crystal substrates of gadolinium gallium garnet (GGG) and operated, in their uniform spin precession mode of resonance, as phase shifters or delay lines for magnetostatic surface waves. Examples of such surface wave devices are described in U.S. Pat. No. 3,864,647 issued Feb. 4, 1975, for "Substantially Linear Magnetic Dispersive Delay Line and Method of Operating It" granted to Bongianni, the inventor herein, and in U.S. Pat. No. 4,028,639 issued June 7, 1977, for "Oscillator Using Magnetostatic Surface Wave Delay Line," granted to Hagon et al. Such devices are subject to the same limitations as bulk YIG devices on higher frequency operation and drift due to temperature variations.
Some researchers in the field have long desired to use single crystal hexagonal ferrites in filters and related devices operating at the higher microwave frequencies and the even higher millimeter wavelength frequencies. One reason for this desire has been that single crystal material has relatively low loss. In addition, the hexagonal ferrites have a relatively very high magnetic anisotropy. Where the magnetic anisotropy is very high, the uniform spin precession mode of resonance may have a resonant frequency which is also very high. This is due to the direct dependence of this resonant frequency on magnetic anisotropy as mentioned above. Furthermore, since hexagonal ferrites such as, for example, BaFe 12 O 19 are known to be permanent magnet materials, it is apparent that resonators formed from them, once magnetized, will require little or no externally applied bias magnetic field to magnetically saturate the material and establish a resonant frequency for a uniform spin precession mode of resonance.
However, resonators are not easily formed from bulk single crystals of the hexagonal ferrites. In addition to their high magnetic anisotropy, these materials have a very high structural anisotropy, or anisotropy of hardness, which results in their being relatively much softer structurally along certain planes than along others. This property makes the hexagonal ferrites extremely difficult to shape and machine.
The interest in hexagonal ferrites has focused, therefore, on obtaining high quality monocrystalline films of hexagonal ferrites epitaxially grown on nonmagnetic single crystal substrates of insulator, or dielectric, material. Some early work in this field is described in U.S. Pat. No. 3,486,937 granted to Linares, Dec. 30, 1969, for "Method of Growing a Single Crystal Film of a Ferrimagnetic Material" and in Stearns et al, Materials Research Bulletin, Vol. 10, pp. 1255-1258, 1975, Pergamon Press, Inc. Later work in this field is reported in Stearns et al, Materials Research Bulletin, Vol. 11, pp 1319-1326, 1976, Pergamon Press, Inc., "Liquid Phase Epitaxy of Hexagonal Ferrites and Spinel Ferrites on NonMagnetic Spinel Substrates" and in Glass et al, U.S. patent application Ser. No. 812,862 for "Epitaxial Growth of M-Type Hexagonal Ferrite Films on Spinel Substrates and Composite" filed July 5, 1977, and assigned to the assignee of the present application. The material in the latter two references describes the manner in which thin epitaxial films of hexagonal ferrite material were prepared for the use of the inventor herein in devices conforming to the subject invention as described hereinafter.
3. Disclosure
The following references are regarded as having pertinence to this invention.
(1) Bongianni "Advanced Epitaxial Ferrite Devices," Project No. IT 161102BH57-03, Final Report, U.S. Army Research Office, Contract #DAAG29-76-C-0017, Jan. 19, 1977.
(2) Lax & Button, "Microwave Ferrites and Ferrimagnetics," McGraw-Hill Book Co., Inc., New York, 1962.
(a) Sec. 7-3, "Metal-backed Slab," pp. 311-312.
(b) Sec. 12-10, "Nonreciprocal Field-displacement Devices," pp. 630-637.
(3) Baynham et al, U.S. Pat. No. 3,748,605, "Tunable Microwave Filters," July 24, 1973.
The contract report, written by the inventor herein, contains the first descriptions of any aspects of the present invention ever written and, starting on p. 8 thereof and in FIGS. 3, 4 and 6 thereof, presents data derived from measurements made on filters constructed in accordance with the present invention. This contract report is hereby incorporated by reference into this specification.
The first passage cited in the text by Lax & Button describes extra absorption peaks occurring in metal-backed insulating ferrite slabs. These extra absorption peaks, called "body resonances," are associated with multiple internal reflections which lead to standing waves within the slab. The condition for standing waves is given by the optical interference formula t=(2n+1)λ/4 where n is any integer including zero, t is the slab thickness, and λ is the wavelength within the ferrite.
The second passage cited in the text by Lax & Button, on pp. 636 and 637 thereof, describes the use of the oriented-magnetoplumbite (hexagonal ferrite) permanent magnet material BaFe 12 O 19 in a field displacement isolator operating at millimeter wavelength frequencies. Due to the very high magnetic anisotropy of the material, the isolator operates without need for an externally applied magnetic bias field.
The patent to Baynham et al, discloses a tunable, microwave frequency filter relying on the effects produced by multiple reflections of electromagnetic waves in magnetic layers sandwiched between waveguide irises, or other microwave discontinuities which are capable of producing large reflection coefficients for electromagnetic radiation.
SUMMARY OF THE INVENTION
This invention provides filters for operation at high microwave frequencies, millimeter wavelength frequencies, and into the far infra red frequencies, wherein resonators employed in the filters have an essentially fixed resonant frequency. The resonators are formed of thin monocrystalline films of hexagonal ferrite material epitaxially deposited on non-magnetic dielectric substrates. The resonant frequencies of such resonators remain essentially fixed despite the variation of an externally applied bias magnetic field.
It is believed that the fixed frequency resonance phenomenon observed is body resonance, as discussed above, wherein the thickness of the film determines the resonant frequency rather than uniform spin precession resonance which is dependent upon magnetic field intensity.
Various types of filters may be fabricated. These include band-pass and band-stop filters. A plurality of individual resonators having resonant frequencies selected to be staggered about a desired center frequency may be cascaded to form a single filter having a modified bandshape. By analogy to the lumped circuit component approach to cascading of tuned LC circuits, filters having relatively more desirable bandshapes such as those found in, for example, Butterworth or Chebyshev filters may be assembled.
In addition, filters of the type disclosed herein may be operated as variable attenuators and modulators.
BRIEF DESCRIPTION OF THE DRAWINGS
Like parts are given like reference numerals throughout the drawings. The figures have not been drawn to scale. Rather, the dimensions therein have been chosen primarily for the sake of illustration.
FIG. 1 is a cross-sectional view of a portion of a band-stop filter combined with a schematic representation of means for applying a magnetic bias.
FIG. 2 shows a band-stop filter similar to that shown in FIG. 1 but having a plurality of resonator stages.
FIG. 3 is a cross-sectional view of a portion of a band-pass filter combined with a schematic representation of means for applying a magnetic bias.
FIG. 4 shows a band-pass filter similar to that shown in FIG. 3 but having a plurality of resonator stages.
FIG. 5 is a schematic diagram for a frequency modulator employing a filter in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a single-stage band-stop filter 10 comprising a wave guide 12 and a thin film 14 of a monocrystalline hexagonal ferrite material disposed in the wave guide 12. The plane of the film 14 is normal to the direction of wave propagation.
The ferrite film 14 is epitaxially deposited on a single-crystal substrate 16 of a dielectric material having non-magnetic properties.
The substrate 16 may be formed from a single crystal of, for example, a non-magnetic spinel such as zinc gallate (ZnGa 2 O 4 ). The natural facets of zinc gallate have a [111] crystallographic orientation. This is an appropriate orientation for the epitaxial growth on the facets of monocrystalline M-type hexagonal ferrite. M-type hexagonal ferrite has the prototype chemical formula BaFe 12 O 19 . A film of this ferrite so deposited on zinc gallate has its c-axis, the axis of easy magnetization, normal to the plane of the film.
The ferrite film 14 and substrate 16 may extend over the entire aperture of the wave guide 12. This is exemplified in FIG. 1 where the film 14 and substrate 16 are shown extending from the lower wave guide wall 18 to the upper wave guide wall 20. However, filters may be formed using the present invention wherein the ferrite film and substrate extend over less than the full aperture of a wave guide in which they are disposed.
Thin ferrite film 14 is shown in FIG. 1 as having a thickness t. The thickness t may be selected to be precisely one-quarter of a wavelength for an electromagnetic wave at a preselected frequency propagating in the hexagonal ferrite material. This selection is in accord with the optical interference formula fiven above and provides for a body resonance in the film 14 at the preselected frequency. Providing a film 14 having a selected thickness t may be accomplished by trimming a thicker film through the use of a suitable etching process, for example, chemical polishing or electron milling.
A particular ferrite film of the type described herein and having a thickness of about one mil was observed to resonate at a frequency of 56.4 GHz. Since the resonance observed appeared to be the fundamental body resonant mode, the wavelength of the electromagnetic wave propagating in the ferrite material was about four mils (about 100 microns) and the speed of propagation in the ferrite was thus about one-sixtieth (1/60) the free space speed of light. An inference may be drawn that a similar film deposited or polished to have a thickness of about 1 micron, which may be accomplished within the state of the art, would have a resonant frequency of about 1410 GHz. The latter frequency is in the range of the far infra-red.
As will be recognized by those skilled in the art, the absorption characteristic of the film 14 for frequencies above and below the resonant frequency will typically have the shape of a Gaussian curve representing the lesser extent that these higher and lower frequencies are also absorbed in the film 14. The bandwidth of the absorption characteristic increases as lossiness of the resonating film 14 increases, i.e., as Q or selectivity decreases. Typically, high Q and narrow bandwidth are preferred. The Q of a given film 14 will depend on its uniformity of thickness for body mode resonance. Thus, Q will be a function of the ratio of t to Δt, the rms surface roughness of the film 14. For example, a film with a surface roughness of about 50 angstroms rms would yield a Q of about 5000 for a one mil film.
It is apparent then that the same chemical polishing procedure used to trim the film 14 to obtain a thickness corresponding to a selected resonant frequency may also serve to increase the selectivity of the resulting resonator.
The ferrite film 14 is backed by a metal wall 22 in conductive contact with the metal structure of the wave guide 12. The metal wall 22 may be a plate, sheet, or film of any suitable high conductivity material such as, for example, gold, silver, copper, or aluminum. The metal wall 22 is a reflector for radiant energy. For example, the arrow 24 represents an incident electromagnetic wave propagating from left to right in the wave guide 12. The radiant energy which reaches the metal wall 22 is reflected back in the direction from which it came. Thus, there is present a reflected electromagnetic wave as represented by the arrow 26. However, where the film 14 possesses a resonant mode, energy in the incident electromagnetic wave at the frequency of the resonance is strongly absorbed in the film 14 and thus greatly attenuated in the reflected wave. That is what gives the configuration of FIG. 1 its characteristics as a band-stop filter. The filter 10 attenuates radiant energy in a band of frequencies centered on the resonant frequency of the film 14.
Having discussed reflection, it is apparent that the condition for standing waves, and thus body resonance, may be stated in a way which is an alternative to, but the equivalent of, the optical interference formula. A body resonance may occur in the film 14 for each frequency of wave propagation in the film for which there is a plane normal to the direction of propagation, in the film or on its surface, where an incident wave and a reflected wave are always out of phase by 180 degrees or an odd multiple of 180 degrees.
It is also apparent that the reflected or filtered wave will, in a typical application, be separated from the incident wave for further processing at a point removed from the filter by, for example, a directional coupler which is well known in the art.
FIG. 1 further shows means for externally applying a magnetic field parallel to the plane of the ferrite film 14. These means comprise the pole pieces 28 and 30, coils 32 and 34, and a voltage source 36 for energizing a direct current in coils 32 and 34. Such apparatus and variations thereof to produce an equivalent result are well known to those skilled in the art.
Tests were conducted in which a film of M-type hexagonal ferrite deposited on a substrate of zinc gallate was disposed in a waveguide in a configuration similar to the band-stop filter 10 shown in FIG. 1. The film is believed to have had a thickness t of between 10 and 20 microns. For each of several different fixed magnetic biases, a transmission measurement was made. The generated frequency of an rf source was swept and any loss from the energy transmitted was measured. The results of some of these tests are summarized in Table I.
TABLE I______________________________________H.sub.o f.sub.r Loss(KOe) (GHz) (db)______________________________________9 39.065 410 39.060 1011 39.055 1212 39.050 14______________________________________
Table I shows four different settings for externally applied magnetic field intensity in kilo-oersteds, the resulting resonant frequency observed, f r , in gigahertz, and the loss of absorption in decibels at the resonant frequency.
It may be observed by examination of Table I that the peak loss, or absorption of radiant energy at the resonant frequency, increases significantly as the applied magnetic field intensity is increased. It may also be observed that the resonant frequency itself changes slightly. The change in resonant frequency is believed to be the result of one or more second order effects such as, for example, magnetostriction causing changes in film thickness or changes in the speed of propagation due to changes in the effective permeability of the ferrite. The changes in resonant frequency are insignificant when compared with the approximately three gigahertz per kilo-oersted change in resonant frequency that would be expected if the mode of resonance was uniform spin precession.
The variation which occurs in peak absorption at the resonant frequency as magnetic field intensity varies, as shown in Table I, may be exploited to adapt the band-stop filter 10 to serve as, for example, a variable attenuator for millimeter wavelength signals. This adaptation is illustrated in FIG. 1 by the inclusion of a variable resistor 38 in the circuit supplying current to the magnet coils 32 and 34. As the intensity of the magnetic field externally applied parallel to the film 14 is varied by varying the variable resistor 38, radiation at or near the resonant frequency incident on the film 14 will experience varying amounts of attenuation as it is reflected.
By varying the magnetic field applied to the film 14 by pole pieces 28 and 30 at relatively higher frequencies, the bandstop filter 10 may be adapted to serve as an amplitude modulator. Such an adaptation is illustrated in FIG. 1 by the inclusion of an rf signal source 40 and transformer means 42 for coupling the signal output thereby to the magnet coils 32 and 34. The rf signal source 40 will cause radiant energy at or near the resonant frequency of the film 14 to vary in amplitude in correspondence with the signal output of the source 40 as the radiation is reflected from the film 14 due to the resultant variation of magnetic field intensity.
FIG. 2 shows a multi-stage band-stop filter 52. The filter 52 is similar to the band-stop filter 10 of FIG. 1 in most respects. However, the filter 52 has a plurality of stages or resonators. In this example, two such resonators are serially disposed in the wave guide 12. One resonator comprises a film 44 of hexagonal ferrite material epitaxially deposited on a single-crystal substrate 46 of dielectric material. The second resonator comprises a film 48 of hexagonal ferrite material epitaxially deposited on a single-crystal substrate 50 of dielectric material. The use of two ferrite films is by way of example only. In the practice of this invention, it is appropriate to use as many such ferrite films disposed to act in cascade as are desired.
In addition, it should be noted that the example given in FIG. 2 wherein the filter 52 has two films 44 and 48 each deposited on distinct substrates 46 and 50, respectively, is also by way of example only. The two films 44 and 48 can be deposited on the opposite sides of the same substrate 46, for example, thus reducing the number of substrates necessary for implementation of this invention. A procedure for accomplishing this result is given in Glass, U.S. Patent Application Ser. No. 831,033 for "Method of Fabricating Multiple Layer Composite," filed Sept. 6, 1977, and assigned to the assignee of the present application.
It is apparent that, in the band-stop filter 52, incident radiation propagating in the direction of the arrow 24 toward metal wall 22 is subject to absorption in two resonators, ferrite film 48 and ferrite film 44, before it is reflected back in the direction of the arrow 26. Each of the films 44 and 48 will absorb energy from the radiation in accordance with its own absorption characteristic. The resultant absorption will thus be cumulative.
The ferrite films 44 and 48 are shown in FIG. 2 as having thicknesses t 1 and t 2 , respectively. Where these thicknesses are equal to each other, the body resonance modes of the films will have substantially the same resonant frequencies. The absorption characteristics of films 44 and 48, each of which will follow that of a Gaussian curve, will combine to form a cumulative characteristic which will also follow a Gaussian curve. However, as is also known, it is often desirable to implement filters wherein the cumulative absorption characteristic has a relatively broader bandwidth in the stop-band and steeper skirts outside the pass-band. By analogy to the well-known principles involved in the design of cascaded tuned LC circuits to provide flat-topped characteristics known as the Butterworth and Chebyshev responses, films 44 and 48 may be given thicknesses different from each other. The different thicknesses can provide for body mode resonant frequencies in the films 44 and 48 which are staggered above and below the desired center frequency for the filter by a predetermined increment. Thus, the bandshape of a band-stop filter which has a plurality of stages such as the filter 52 may be modified and improved over that of a single-stage filter.
Band-stop filter 52 is provided with means for externally applying a magnetic field to films 44 and 48 in the planes of the films and with means for modifying the externally applied field to cause the filter 52 to operate as a variable attenuator or as an amplitude modulator. These aspects of the invention were discussed above in connection with the filter 10 of FIG. 1.
FIG. 3 shows a single-stage band-pass filter 74 comprising a wave guide 54 and a thin film 56 of a monocrystalline hexagonal ferrite material disposed in the wave guide 54. The plane of the film 56 is normal to the direction of wave propagation. The ferrite film 56 is epitaxially deposited on a single-crystal substrate 58 of a dielectric material.
All of the same considerations apply to the materials of the film 56 and the substrate 58 as were discussed above in connection with the film 14 and the substrate 16 of the filter 10 shown in FIG. 1.
The ferrite film 56 and substrate 58 may extend over the entire aperture of the wave guide 54. This is exemplified in FIG. 3 where the film 56 and substrate 58 are shown extending from the lower wave guide wall 60 to the upper wave guide wall 62. However, filters may be formed using the present invention wherein the ferrite film and substrate extend over less than the full aperture of a wave guide in which they are disposed.
Thin ferrite film 56 is shown in FIG. 3 as having a thickness t. The selection of a thickness t to provide for a preselected resonant frequency for body mode resonance in the film 56 is subject to the same considerations as were discussed above in connection with the film 14 of FIG. 1. These considerations include the applicability of the optical interference formula.
The ferrite film 56 is backed by a metal wall 64 in conductive contact with the metal structure of the wave guide 54. The metal wall 64 is an iris having an aperture 66 provided in its central portion. The aperture 66 allows some of the radiation which reaches the wall 64 to continue to propagate in the same direction. Otherwise, the metal wall 64 is similar to the metal wall 22 discussed above in connection with the filter 10 of FIG. 1. The size of the aperture 66 has no effect on the bandshape of the filter 74. However, the selection of aperture size does affect the attenuation of the filter 74.
More specifically, the arrow 68 in FIG. 3 represents the direction of propagation for incident radiation. Some of the incident radiation is reflected back in the direction from which it came as represented by the arrow 70. However, some fraction of the radiant energy incident on the ferrite film 56 will not be reflected by the metal wall 64 but will be coupled into the iris aperture 66 and transmitted forward in the direction represented by the arrow 72. When the film 56 possesses a resonant mode, energy in the incident electromagnetic wave at the frequency of the resonance is most strongly coupled into the iris aperture 66. Radiant energy at frequencies above and below the resonant frequency will be coupled into the iris aperture 66 to a lesser extent according to the typical Gaussian characteristic discussed previously. Thus, the filter 74 of FIG. 3 is a band-pass filter which transmits radiant energy in a band of frequencies centered on the resonant frequency of the film 56.
The operation of the filter 74 as a band-pass filter in the forward direction is consistent with its operation in the back or reflected direction as a band-stop filter in a manner similar to the filter 10 of FIG. 1. That is to say that where more radiant energy at a given frequency is selected by the filter 74 to be transmitted in the forward direction, it follows that less radiant energy at that frequency will appear in the reflected wave.
FIG. 3 further shows means for externally applying a magnetic field parallel to the plane of the ferrite film 56. These means comprises the pole pieces 28 and 30, coils 32 and 34, and a voltage source 36 for energizing a direct current in coils 32 and 34. In addition, a variable resistor 38 is included in the circuit supplying current to the magnet coils 32 and 34. In a manner complementary to the situation discussed in connection with the band-stop filter 10 of FIG. 1, the band-pass filter 74 can also be made to operate as a variable attenuator. The filter 74 will respond to changes in the intensity of the externally applied magnetic field by changing the output level, or amplitude, of a given frequency of radiation within the pass band of the filter 74.
Similarly, by varying the magnetic field applied to the film 56 by pole pieces 28 and 30 at relatively higher frequencies, the band-pass filter 74 may be adapted to serve as an amplitude modulator in the same manner as was the band-stop filter 10 of FIG. 1. Such an adaptation is illustrated in FIG. 3 by the inclusion there of an rf signal source 40 and transformer means 42 for coupling the signal output thereby to the magnet coils 32 and 34.
FIG. 4 shows a multi-stage band-pass filter 84. The filter 84 is similar to the band-pass filter 74 of FIG. 3 in most respects. However, the filter 84 has a plurality of resonators and in this respect resembles the multi-stage band-stop filter 52 of FIG. 2. In the filter 84, two resonators are serially disposed in the wave guide 54. One resonator comprises a film 76 of hexagonal ferrite material epitaxially deposited on a single-crystal substrate 78 of dielectric material. The second resonator comprises a film 80 of hexagonal ferrite material epitaxially deposited on a single-crystal substrate 82 of dielectric material. Here again, the use of two ferrite films in the filter 84 is by way of example only. In the practice of this invention, it is appropriate to use as many such ferrite films disposed to act in cascade as are desired. In addition, it is appropriate to deposit the two films 76 and 80 on the opposite sides of, for example, the substrate 78, as discussed above in connection with the filter 52 of FIG. 2. This would make the use of the substrate 82 unnecessary.
It is apparent that, in the band-pass filter 84, the same considerations apply as were discussed in connection with the band-stop filter 52 of FIG. 2 with regard to obtaining a modified and improved bandshape for the filter characteristic. The film 76, having a thickness t 3 , and the film 80, having a thickness t 4 , may be fabricated so that the body mode resonant frequencies for films 76 and 80 are staggered above and below the desired center frequency for the filter. Butterworth and Chebyshev responses may be achieved or approximated in this manner.
As in the case of all of the filters previously discussed, the band-pass filter 84 is also provided with means for externally applying a magnetic field to the films 76 and 80, with means for varying the attenuation of the filter, and with means for causing it to function as an amplitude modulator.
FIG. 5 shows a schematic representation of an electronic circuit employing a filter in accordance with the subject invention wherein the circuit is a frequency modulator 86. As was mentioned above in connection with the discussion of Table I, a filter in accordance with this invention experiences a small second-order change in resonant frequency as an externally applied magnetic field is varied. These filters, being resonators, are frequency selective. FIG. 5 shows an amplifier 88 coupled to, for example, a band-pass filter 90 in a closed regenerative loop so as to form an oscillator which oscillates at the selected resonant frequency of the filter 90. The band-pass filter 90 may be similar to either band-pass filter 74 of FIG. 3 or band-pass filter 84 of FIG. 4. Band pass filter 90 includes means for varying the resonant frequency thereof, in the manner indicated by Table I, by, for example, an rf signal generator such as the rf signal generator 40 of FIG. 3. Given the configuration just described, the output signal appearing at the terminal 92 of frequency modulator 86 will be frequency modulated in correspondence with an rf signal supplied by the generator.
While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in details may be made therein without departing from the spirit and scope of the invention as set out in the following claims. For example, the use of substrates for the magnetic films might be omitted in appropriate cases. | Films of epitaxially deposited hexagonal ferrite material backed with metal and inserted into waveguides in single and multiple stages are used to form band-pass and band-stop filters, variable attenuators and modulators. The films have body resonance modes with resonant frequencies which are essentially fixed as an externally applied magnetic field is varied. Thin films of hexagonal ferrite material have resonant frequencies in the high microwave and millimeter wavelength frequency ranges. Since hexagonal ferrites have a high magnetic anisotropy and accompanying high internal magnetic field, little or no external magnetic bias may be required once the film is magnetized. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Patent Application No. 61/709,091. The contents of that application are hereby incorporated by reference in their entirety.
BACKGROUND
The use of autonomous or unmanned vehicles is growing. Unmanned vehicles may be suitable for a variety of industries including construction, manufacturing, and military. While there are many advantages associated with the use of autonomous vehicles, there are also several issues.
On such issue is safety. For example, how do we ensure that unmanned vehicles can be stopped should they become unresponsive due to a software malfunction, or when a remote operator becomes incapacitated or otherwise loses control of the vehicle? Another issue is interoperability. Currently there exist many proprietary systems for unmanned vehicles, making it difficult to design systems or applications that will work across a variety of vehicle systems and types.
SUMMARY
An open architecture control system is provided that may be used for remote and semi-autonomous operation of commercial off the shelf (COTS) and custom robotic systems, platforms, and vehicles to enable safer neutralization of explosive hazards and other services. In order to effectively deal with rapidly evolving threats and highly variable operational environments, the control system is built using an open architecture and includes a high level of interoperability. The control system interfaces with a large range of robotic systems and vehicles, autonomy software packages, perception systems, and manipulation peripherals to enable prosecution of complex missions effectively. Because the control system is open and does not constrain the end user to a single robotics system, mobile platform, or peripheral hardware and software, the control system may be used to assist with a multitude of missions beyond explosive hazard detection and clearance.
In an implementation, a method may include: receiving a current location of an operator at an instrument control system of an unmanned vehicle; determining a leading distance of the unmanned vehicle by the instrument control system; determining a current location of the unmanned vehicle by the instrument control system; determining if a difference between the current location of the operator and the current location of the unmanned vehicle is less than the leading distance; and if so, increasing the speed of the unmanned vehicle by the instrument control system.
In some implementations, the method may further include: determining if a difference between the current location of the operator and the current location of the unmanned vehicle is greater than the leading distance; and if so, decreasing the speed of the unmanned vehicle by the instrument control system. The method may further include that the current location of the operator is received from a hand held controller, and that the leading distance is randomly generated.
In an implementation, a system for halting the operation of machinery may include: at least one e-stop controller comprising a first radio; and at least one e-stop comprising: a second radio; a software based failsafe; and a hardware based failsafe, wherein the hardware based failsafe is adapted to: monitor a wireless connection between the first radio and the second radio; determine if the wireless connection has been severed; and if so, halt machinery associated with the e-stop; and wherein the software based failsafe is adapted to: receive a first signal from the e-stop controller via the second radio; and determine whether to halt the machinery associated with the e-stop based on received first signal.
In some implementations, the system may further include that the first signal is a heartbeat signal, and the software based failsafe may determine not to halt the machinery associated with the e-stop based on the heartbeat signal. The first signal may be a stop signal, and the software based failsafe may determine to halt the machinery associated with the e-stop based on the stop signal. The system may further include that the e-stop controller is further adapted to: determine whether to halt the machinery associated with the e-stop; and if so, sever the wireless connection between the first radio and the second radio. Severing the wireless connection may include turning off the first radio. Determining whether to halt the machinery associated with the e-stop may include determining that a second signal has not been received from the e-stop for more than a threshold amount of time. The second signal may be a heartbeat signal.
In some implementations, the system may further include a plurality of e-stops and e-stop controllers, wherein the plurality of e-stops and e-stop controllers form a mesh network. The e-stop controller may be automatically associated with the e-stop based on a distance between the e-stop and the e-stop controller. The e-stop may include a first location determiner and the e-stop controller may include a second location determiner, and further wherein: the e-stop is adapted to determine a first location of the e-stop using the first location determiner and send the determined first location to the e-stop controller; and the e-stop controller is adapted to determine a second location of the e-stop controller using the second location determiner, determine if a distance between the first and second locations exceeds a threshold, and if so, determine to halt the machinery associated with the e-stop. Determining to halt the machinery associated with the e-stop may include one of sending a stop signal to the e-stop and turning off the first radio. The machinery may be an unmanned vehicle.
In an implementation, a system for controlling unmanned vehicles may include: a vehicle integrated control system that is non-destructively integrated into the unmanned vehicle; and an operation control unit that generates one or more instructions and provides the generated one or more instructions to the vehicle integrated control unit, wherein the vehicle integrated control unit is adapted to receive the generated one or more instructions, and in response to the generated one or more instructions, control the operation of the unmanned vehicle, and further wherein the operation control unit is adapted to receive one or more of sensor data and location data from the vehicle integrated control unit, and to make the one or more of sensor data and location data available to one or more devices over a network.
In an implementation, the system may further include that the devices are one or more of smart phones, laptops, or tablets. The operation control unit may include a Hand Held Controller and a Remote Viewing Sensor.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the embodiments, there is shown in the drawings example constructions of the embodiments; however, the embodiments are not limited to the specific methods and instrumentalities disclosed. In the drawings:
FIG. 1 is a high level illustration of the OIP;
FIG. 2 is a more detailed illustration of the OIP;
FIG. 3 is an illustration of a vehicle control scenario using the OIP;
FIG. 4 is an illustration of an example VSC;
FIG. 5 is an illustration of an example HHC;
FIG. 6 is an illustration of an example e-stop;
FIG. 7 is an illustration of an example mesh network formed by e-stops and e-stop controllers;
FIG. 8 is an illustration of an example method for increasing or decreasing a speed of a vehicle based on a leading distance; and
FIG. 9 is an illustration of an example computing environment where aspects of the invention may be implemented.
DETAILED DESCRIPTION
FIG. 1 is a high level illustration of the Open Integration Platform (OIP) 100 . The OIP 100 is a control system for unmanned vehicles that translates user commands into manipulations or movements of the unmanned vehicle and provides for failsafe integration of third-party software, sensors, and actuation peripherals through an application programming interface (API). The OIP 100 may be configured to communicate with many robotic systems and vehicle command protocols and is portable across platforms in alternate operational scenarios.
The OIP 100 may be designed to allow for easy integration with respect to one or more components through the API. Examples of such components are illustrated in FIG. 1 , and include autonomy software component 110 , perception component 120 , unmanned system component 130 , and manipulation components 140 . Other components may be supported.
As will be described further below, the OIP 100 may further include one or more built-in or base features. One example of such a feature is the ability to interface and control a variety of vehicles. The OIP 100 may support a variety of vehicle control interfaces including Drive-by-wire, for example. Other vehicle control interfaces may be supported. The vehicle control commands and protocols used for a variety of vehicle types may be abstracted by the API into a single vehicle control library of functions, allowing users and programmers to create a single custom software component that may be used to control a variety of vehicle types using the API. The OIP 100 may similarly provide a single library of functions that may be used to control and interact with a variety of sensors and peripheral devices.
Another example of an integrated feature is safety features. The safety features may be integrated into the OIP and kept separate from the other components of the OIP such that one or more of the autonomy software components 110 , unmanned system components 130 , perception components 120 , and manipulation components 140 can be changed by users without compromising the safety of the system as a whole. Further, such built in safety features allow users to create their own components for the OIP 100 using the API without having to consider how to implement safety features, or worrying about interfering with existing safety features.
Any unmanned system developed using the OIP 100 as the integration hub may achieve the following advantages when compared with existing systems:
Flexibility: The flexible API provided by the OIP 100 allows for a wide variety of components to be easily added or removed from any unmanned system that uses the OIP 100 . For example, users may add or remove components from the unmanned system as threats, mission needs, technologies, or budgets change. The open system of the OIP 100 ensures that the user can use a range of sensors and/or software components from a wide range of providers in their unmanned system, not just those provided by the original manufacturer of the unmanned system.
Safety: By separating the safety features from the computation engine, any unmanned system built using the OIP 100 is assured a high level of safety. Furthermore, an open system built on OIP 100 may allow the components to be changed or modified without affecting the safety features of the system.
Speed: Any unmanned vehicle built using the OIP 100 includes locked down protocols for low-level critical commands and safety supervision. Because these crucial elements of the system remain unchanged, all other elements of the system can be changed much faster than if the core elements had to be redesigned and integrated.
Cost: Any customer or partner using the OIP 100 may be able to avoid substantial development costs for the base hardware and software that enables unmanned system integration. By relying on the OIP 100 for this core, a user would benefit from significant development and testing already completed for the OIP 100 .
Innovation: Threats, tasks, technologies, and budgets change all the time in the world of unmanned systems, and increased innovation is required to confront such complexity. By utilizing an open system the OIP 100 , the user, customer, partner, and stakeholders can rely on a wealth of easily integrated existing technology to help solve problems and reduce complexity much faster, cheaper, and with higher quality than with closed systems.
FIG. 2 is a more detailed illustration of the OIP 100 . In the example shown, the OIP 100 is broken down into two major subsystems: the Vehicle Integrated Control System (VICS) 200 and the Operator Control Unit (OCU) 250 . The VICS 200 may provide a non-destructive means through which one or more users may control a vehicle, may receive information about the vehicle, or may receive information from or control the operation of one or more peripheral devices 210 associated with the vehicle. The VICS 200 is non-destructive in that the vehicle may be operable by an in-vehicle driver even when the VICS 200 is attached or otherwise integrated into the vehicle, and when the VICS 200 is removed the functions of the vehicle are not impaired.
The OCU 250 , on the other hand, may provide one or more customizable user interfaces through which one or more users may control the vehicle through the VICS 200 . The user interfaces may also be used to view data provided by the VICS 200 , or from the peripheral devices 210 associated with the VICS 200 . Other components and/or subsystems may be supported. The peripheral device devices 210 may include, but are not limited to, cameras, lights, weapons and other sensors.
Together, the OCU 250 and the VICS 200 may be used to provide control over an unmanned vehicle, and may allow one or more operators of the unmanned vehicle to view and share data provided by one or more of the peripheral devices 210 , or from the vehicle itself.
In some implementations, the VICS 200 may include a Vehicle Systems Controller (VSC) 230 . The VSC 230 may be adapted to non-destructably interface with a variety of vehicles using a variety of interfaces and/or control systems such as Drive-by-wire (J1939), Direct-drive electric motors (typically found in small robots), and Hydraulic or mechanical controls. Other systems or interfaces may be supported. The VSC 230 may receive a variety of diagnostic and status information from the vehicle including, but not limited to speed, temperature, oil pressure, fuel level, tire pressure, or any other information supplied by a vehicle in its normal operational state. The VSC 230 may also include one or more integrated sensors such as an accelerometer, a GPS or other location detection means, a magnetometer, a thermometer, and a barometer, for example. Other sensors may also be supported. The VCS 230 may be implemented using a general purpose computing device such as the computing system 900 described with respect to FIG. 9 . An exemplary VCS 230 is described further with respect to FIG. 4 .
The VSC 230 may provide such information to one or more users associated with the OCU 250 through a wireless communication means that may be integrated into the VSC (i.e., Bluetooth, Wi-Fi, etc.). Alternatively, or additionally, the VSC may provide such information to one or more smart phones, tablets, or any other devices that are able to receive data via a wireless interface.
For example, an owner of a fleet of construction vehicles may use the OCU 250 , or a smart phone associated with the owner, to query a VSC 230 connected to each of the vehicles in the fleet. Each VSC 230 may receive the query and may provide the status information associated with its associated vehicle to the OCU 250 . The owner may then use the status information assisted with each vehicle to determine which vehicles may require servicing.
The VSC 230 may also control the operation of the vehicle through the one or more interfaces. For example, the VSC 230 may control the throttle, brakes, transmission, lights locks, or any other systems of a vehicle that may be controlled electronically through an interface. In some implementations, the VSC 230 may control the operation of the vehicle based on one or more signals received directly from the OCU 250 . In other implementations, the VSC 230 may control the operation of the vehicle based on one or more signals received directly from an Instrument Control System (ICS) 220 of the VICS 200 .
In some implementations, the ICS 220 may include electrical and computer networking components and may interface with, and provide power to, a variety of components including lights, sensors, and cameras (i.e., the peripheral devices 210 ). The supported computer networking components may include Ethernet (powered or unpowered), USB, Bluetooth, eSATA, or any other type of networking or connecting means. The ICS 220 may receive power from a vehicle that the ICS 220 is mounted to, or may include its own power source such as a battery or one or more solar panels. In implementations where the ICS 220 receives power from the vehicle, the ICS 220 may include a fuse or other means to limit the amount of current that is drawn from the vehicle. The ICS 220 may be attached to a vehicle through a roof mount. Other vehicle locations or attachment means may be supported.
The ICS 220 may further include a locating means 215 . The locating means 215 may determine the location of the ICS 200 , and therefore the location of the vehicle that the ICS 220 is attached to. Any one of a variety of technologies for determining locations such as GPS, and cellular triangulation may be used.
The ICS 220 may a wireless interface 211 . The wireless interface 211 may include one or more radios and may be capable of receiving one or more control signals from the OCU 250 . The ICS 220 may further be capable of transmitting data from one or more of the peripheral devices 210 that are connected to the ICS through the one or more radios of the wireless interface 211 . The transmitted data may include output from the VSC 230 (e.g., information from and about the vehicle including speed, oil pressure, and other diagnostic information), signals from one or more of the peripheral devices 210 connected to the ICS 220 (e.g., video, audio, temperature, and other sensor data), and location information determined by the locating means 215 . In some implementations, both the control signals from the OCU 250 and the data signals from the ICS 220 may be received and provided by the same radio and/or frequencies of the wireless interface 211 . Alternatively, different radios and/or frequencies may be used for control signals and data signals. The ICS 220 may be implemented by a general purpose computing device such as the computing system 900 described with respect to FIG. 9 .
The ICS 220 may further include one or more emergency stops (e-stops) 284 . When the ICS 220 receives a signal from the e-stop 284 , the ICS 220 may immediately disable the vehicle by sending the appropriate signal(s) to the VSC 230 . For example, in one implementation, the e-stop 284 may be highly visible button that is located inside and/or outside the vehicle. When the button is pushed, the ICS 220 may signal the VSC 230 to immediately stop the vehicle by applying the brakes and/or disengaging the throttle, for example. The particular steps or actions that occur upon engaging an e-stop 284 may be set by a user or administrator. The e-stops 284 may be both wired and wireless. In addition, in some implementations, the e-stop 284 signal may also be received directly by the VSC 230 providing additional safety protection and isolation from the various components of the ICS 220 . The e-stops 284 may be integrated into the OIP 100 , may be integrated into a third-party control and automation system, or may function as a stand-alone system as will be described further bellow.
In some implementations, each e-stop 284 may be wirelessly controlled by one or more e-stop controllers 285 . When a user or operator of the e-stop controller 285 determines that the vehicle (or other stationary and non-stationary machinery such as factory equipment or farm equipment) should be stopped, the user may use the e-stop controller 285 to send a stop signal to the e-stop 284 corresponding to the vehicle. The e-stop 284 may then receive the stop signal, and may instruct the ICS 220 and/or VSC 230 to deactivate the vehicle.
In some implementations, each e-stop 284 associated with a vehicle or VICS 200 may have its own associated e-stop controller 285 . Alternatively, one e-stop controller 285 may be associated with a variety of e-stops 284 within a selected range of the e-stop controller 285 , or are otherwise paired with the e-stop controller 285 . For example, a fleet of unmanned vehicles may be used on a construction site. Each vehicle may have a VICS 200 with an associated e-stop 284 . One or more foremen associated with the construction site may receive an e-stop controller 285 (a wireless dongle, for example) that is associated with or paired with the e-stops 284 of all the vehicles used on the construction site. If a foreman believes that an accident has occurred or that the safety of a worker is being compromised, the foreman may activate the e-stop controller 285 which will cause each associated e-stop 284 to disengage its associated vehicle.
In another implementation, a user associated with an e-stop controller 285 may select the particular e-stop 284 that it would like to send a stop signal to. For example, the e-stop controller 285 may have a display that includes a list of the e-stops 284 and/or the vehicles or machinery associated with each e-stop 284 . A supervisor could use the display of the e-stop controller 285 to choose a specific vehicle or machinery that is behaving in an unsafe manner or may be malfunctioning, and may activate the e-stop 284 associated with that vehicle or machinery only. Such remote e-stop controller 285 functionality could be distributed to multiple individuals with safety responsibility, forming a distributed network of e-stops 284 and e-stop controllers 285 . Any individual in this network could choose any machine within the network that they would like to stop using the e-stop controller 285 , and activate the e-stop 285 for that vehicle specifically to disengage it. Both the e-stop 284 and e-stop controller 285 may be implemented using a general purpose computing device such as the computing system 900 illustrated with respect to FIG. 9 .
Additional safety features may be integrated into the VSC 230 . For example, in some implementations, the VSC 230 may receive what is referred to as heartbeat signal from the ICS 220 that indicates that the IC 220 is receiving signals from OCU 250 . If the heartbeat signal is not received by the VSC 230 from the ICS 220 , the VSC 230 may immediately shut down or disengage the vehicle, or alternatively may gradually slow the vehicle. By providing the safety functionality within the VSC 230 rather than the ICS 220 , the safety of the vehicle is not compromised by the particular sensors or peripheral devices 210 that are connected to the ICS. 220
The ICS 220 may further include a Shared Control Module (SCM) 240 . The SCM 240 may be a computing device (such as the computing system 900 ) and may provide the API functionality described herein. The ICS 220 may allow one or more customized control modules to interface with the ICS 220 and the one or more peripheral devices 210 that are connected to the ICS 220 including the VSC 230 . Thus, for example, a user may interact with the sensors connected to the ICS 220 using the API provided by the SCM 240 . The SCM 240 may then translate the various function calls of the API into the particular format or protocols expected by each peripheral device 210 . Similarly, a user may create an application that controls the vehicle using the API without knowing the particular functions or protocols used by the vehicle. The SCM 240 may then translate the function calls of the API according to various functions and/or protocols that are expected by the vehicle. Thus, the SCM 240 provides a layer of abstraction of the vehicle and peripheral device 210 interfaces that allows a single application to work with a wide variety of vehicle and peripheral device types.
The OCU 250 may include a hand held controller (HHC) 280 . The HHC 280 may be a controller that provides control data or instructions to the ICS 220 and/or directly the VSC 230 . In some implementations, the HHC 280 may include one or more analogue control sticks and/or buttons that may be used to control the steering, braking, throttle, and other functionality of the vehicle. The HHC 280 may further control other operations of the vehicle including locks, lights, and horn, for example. In some implementations, the HHC 280 may also control the operation of one or more sensors or other peripheral devices 210 of the ICS 220 . The HHC may include a GPS, or other location determination means, and may provide the location of the HHC along with any control data to the ICS/VSC. The HHC 280 may be ergonomic, waterproof, and rugged. An example schematic of the HHC is illustrated in FIG. 5 . Note that all wireless communication described herein between the OCU 250 and the VICS 200 may be encrypted or otherwise protected.
In addition to the HHC 280 , in some implementations, the OCU 250 may further include one or more Remote Viewing Stations (RVS) 260 . The RVS 260 may be a rugged portable system allowing one or more users to monitor the ICS 220 and/or VCS 230 remotely. The RVS 260 may include a power source such as a battery 262 , and may allow for the charging one or more devices 270 including the HHC 280 . The RVS 260 is intended to be easily carried by an operator, or may be stored in a vehicle (including the unmanned vehicle) until needed. The RVS 260 may be implemented using a general purpose computing device such as the computing system 900 illustrated with respect to FIG. 9 .
The RVS 260 may further include a wireless interface 261 . The wireless interface 261 may include one or more radios and/or antennas, and may be used to receive data (such as location information, speed, etc.) from the ICS 220 and/or VSC 230 and may make the received data available to one or more devices 270 such as smart phones, tablets, laptops, etc. In some implementations, the RVS 260 may use the wireless interface 261 to create a protected Wi-Fi network that operators may connect to in order to view sensor data on their devices 270 . In some implementations, the operators may use their personal devices to control the vehicle, or to control the operation of one or more sensors or peripheral devices 210 of the ICS 220 and/or VSC 230 . The RVS 260 may pass on any commands or instructions received by the RVS 260 to the ICS 220 or VSC 230 depending on the implementation.
The RVS 260 may further include one or more safety features. For example, the RVS may include an e-stop controller 285 .
FIG. 3 is an illustration of an example scenario where an OCU 250 is used to control a vehicle 300 through a VICS 200 . In the example shown, the vehicle 300 is a bulldozer. However, a variety of vehicles may be supported.
The vehicle 300 includes a vehicle system 310 that is connected to the VCS 230 of the VICS 2000 . The vehicle system 310 may be a drive by wire system, and may include an interface such as a 50 pin signal connector through which the VCS 230 may provide commands to the vehicle 300 , and may receive information from the vehicle such as speed, oil pressure, fuel level, engine temperature, etc. The VCS 230 may provide commands to the vehicle systems 310 to activate various controls associated with the vehicle 300 including lights, throttle, and brakes, for example.
The VCS 230 may receive operating instructions from the HHC 280 , and may provide the instructions to the vehicle systems 310 . Alternatively, or additionally, the VCS 230 may receive instructions from one or more devices associated with the RVS 260 . For example, an operator of the HHC 280 , may use a stick or control pad associated with the HHC 280 to cause the vehicle 300 to turn left. The HHC 280 may then provide a corresponding command wirelessly to the VCS 230 . The VCS 230 may generate a command that may cause the vehicle system 310 to turn left, and may provide it to the vehicle systems 310 . The vehicle 300 may then turn left.
The VSC 230 may provide the status information from the vehicle systems 310 to the ICS 220 . As shown the ICS 220 may be attached to the roof or exterior of the vehicle to maximize the wireless range of the ICS 220 . The ICS 220 may then provide the status information to the RVS 260 where the status information may be displayed or made available by the RVS 260 .
In addition, the ICS 220 may determine a location of the vehicle 300 , and may receive data from one or more peripheral devices 210 attached to the ICS 200 , such as a camera. The location, peripheral device 210 data, and VCS 230 data may be provided to the RVS 260 where the data may be viewed by an operator of the RVS 260 and/or one or more devices 270 .
For example, the RVS 260 may receive the current speed and location of the vehicle 300 from the VSC 230 , along with video from a video camera peripheral device 210 mounted on the top of the vehicle 300 . An operator of the RVS 260 may view a map that indicates the location of the vehicle 300 , along with the video received from the peripheral device 210 . In addition, the locations of other vehicles 300 may also be displayed on the map, and the operator may use the RVS 260 (or other connected device 270 ) to select the vehicle 300 whose video data the operator desires to view.
The VICS 200 also includes an e-stop 284 . The e-stop 284 may be placed on the outside of the vehicle 300 so that an operator may manually activate the button or switch associated with the e-stop to halt the vehicle 300 . When activated the e-stop 284 may send a signal to one or both of the ICS 220 and VSC 230 to cause the vehicle 300 to be immediately stopped.
In addition, the OCU 250 includes a corresponding e-stop controller 285 that can be used to halt the vehicle 300 . The e-stop controller 285 may be a standalone device or may be integrated into some of all of the HHC 280 and the RVS 260 . An operator may activate the e-stop controller 285 and the controller 285 may provide a stop signal that is received directly by the e-stop 284 or indirectly by either the VCS 230 or the ICS 220 . In response to receiving the stop signal the vehicle 300 may halt as if the corresponding switch on the e-stop 284 had been activated.
Depending on the implementation, e-stop controller 285 and the e-stop 284 may include additional safety and/or failsafe features. For example, the e-stop 284 may monitor the state of the wireless connection between them. Should the e-stop 284 detect that the connection has been severed; the e-stop 284 may immediately halt the operation of the vehicle 300 as if the e-stop controller 285 had issued a stop command. Should the wireless connection be restored, the e-stop 284 may reactivate the vehicle 300 . The wireless connection based failsafe may be implemented in hardware, for example
As another level of failsafe, the e-stop 284 may periodically receive a heartbeat signal from the e-stop controller 285 . Should the e-stop 284 not receive the heart beat signal from the e-stop controller 285 within a defined time interval, the e-stop 284 may deactivate the vehicle 300 .
In addition, the e-stop 284 may also send a heartbeat signal to the e-stop controller 285 . Should the e-stop controller 285 not receive the signal, the controller 285 may send a stop signal, and then may deactivate the wireless connection between the e-stop controller 285 and the e-stop 284 . Should the e-stop 284 not receive or understand the stop signal because of a software malfunction, the hardware implemented failsafe will cause the e-stop 284 to deactivate the vehicle 300 . Alternatively, the e-stop controller 285 may deactivate the wireless connection without sending the stop signal, which will similarly result in the e-stop 284 deactivating the vehicle 300 .
FIG. 4 is an illustration of an example VCS 230 . As shown, the VCS 230 includes several components including a processing means 410 , wireless interface 405 , an ICS interface 406 , a vehicle interface 407 , and a fuse 409 . More or fewer components may be supported.
The vehicle interface 407 may allow the VCS 230 to send data to, and receive data from, the vehicle systems 310 . The data that the VCS 230 sends to the vehicle systems 310 may be control data such as instructions to apply brakes, increase or decrease speed, steering instructions, and instructions to turn on one or more lights. The received data may include status data such as information about an amount of remaining fuel and other diagnostic information about the vehicle. In some implementations, the vehicle interface 407 may be a 50 pin connector. However, other types of wired or wireless interfaces may be used.
The ICS interface 406 may allow the VCS 230 to send data to, and receive data from, the ICS 220 . As described previously, in some implementations, the ICS 220 may be externally mounted to the vehicle and may include one or more peripheral devices 210 such as cameras or other sensors. In addition, the ICS 220 may receive control commands or instructions from one or more of the HHC 280 or the RVS 260 , and may also provide information to the RVS 260 and/or HHC 280 regarding the status of the associated vehicle and data from the peripheral devices 210 . Accordingly, the ICS interface 220 may allow the ICS 220 to pass any received control commands to the VCS 230 , as well as the VCS 230 to provide any requested status information received from the vehicle systems 310 to the ICS 200 . In some implementations, the ICS 406 may be a 24 pin signal connector. However, other types of wired or wireless interfaces may be used.
The wireless interface 405 may receive and/or transmit data to one or more of the RVS 260 and the HHC controller 280 . The received data may include control instructions from the HHC controller 280 and/or the RVS 260 . The transmitted data may include status information from the vehicle systems 310 , sensor information, and location information, for example. The wireless interface 405 may include one or more antennas and may support a variety of standards, protocols, and frequencies such as Wifi, cellular, Bluetooth, 1.3 Ghz, 2.4 Ghz, 5.8 Ghz, and 900 Mhz. In some implementations, the control signals may be received using a different frequency and/or antennae than is used to send status information.
The processing means 410 may execute software that manages and routes data to and from the various components of the VCS 230 . For example, the processing means 410 may receive control instructions from one or more of the ICS interface 406 and/or wireless interface 405 and may pass the control instructions to the vehicle systems 310 via the vehicle interface 407 . Similarly, the processing means 410 may provide status data received from the vehicle systems 310 via the vehicle interface 407 to one or more of the wireless interface 405 and the ICS interface 406 . When routing data to and from the various components of the VCS 230 the processing means may transform or format the data into whatever formats are expected or supported by the receiving components. The processing means 410 may include a processor and memory.
The processing means 410 may further interface with an e-stop 284 . The e-stop 284 may generate a stop signal that is received by the processing means 410 . Upon receipt of the stop signal, the processing means may instruct the vehicle systems 310 via the vehicle interface 407 to immediately halt the vehicle. Alternatively, or additionally, the e-stop 284 may generate a heartbeat signal that is received by the processing means 410 . In the event that the heartbeat signal ceases (either because the e-stop 284 has been activated or malfunctioned) the processing means 410 may instruct the vehicle systems 310 via the vehicle interface 407 to immediately halt the vehicle.
The processing means 410 may further receive power through the fuse 409 , and may distribute the power to the various components of the VCS 230 via a bus. The fuse 409 may receive power from a vehicle power source 420 associated with the vehicle. The power may be received via a 4 pin power connector; however other connectors or connector types may be used. The fuse 409 may limit the amount of power that the VCS 230 may draw from the vehicle at any time thereby preventing the VCS 230 from inhibiting the amount of power that is available to the vehicle. In some implementations, the power from the fuse 409 may be further distributed to the ICS 220 via the ICS 406 interface.
While not shown, the VCS 230 may include additional components or sensors such as an accelerometer, a GPS, or other location determination means. In addition, the VCS 230 may include a battery or other power source that is independent of the vehicle power source 420 .
FIG. 5 is an illustration on an example HHC 280 . As shown the HHC 280 include one or more components including, but are not limited to a wireless interface 501 , sensors 502 , battery 504 , display 505 , user controls 540 , an e-stop controller 530 , and a processing means 510 . More or fewer components may be supported.
The wireless interface 501 may receive and/or transmit data to one or more of the ICS 220 and the VCS 230 . As described above, the HHC 280 may be used by an operator to control a vehicle via one or more of the ICS 220 and the VSC 230 . The received data may include status information from the vehicle systems 310 , location information associated with the vehicle, vehicle sensor data, and peripheral device 210 data, for example. The transmitted data may include control data and other instructions generated by the operator of the HHC 280 . The wireless interface 501 may include one or more antennas and may support a variety of standards, protocols, and frequencies such as Wifi, cellular, Bluetooth, 2.4 Ghz, 5.8 Ghz, and 900 Mhz. In some implementations, the control signals may be sent using a different frequency and/or antennae than is used to receive status information or peripheral device 210 data.
The HHC 280 may include user controls 540 . The user controls 540 may include a variety of input means such as buttons and joysticks. The input means may be digital, analogue or some combination of both. The input means may be mapped to variety of vehicle systems 310 and controls such as throttle, brakes, and steering. In addition, one or more of the input means may be mapped to one or more peripheral devices 210 such as lights, camera, or weapons systems. The particular mapping of the user controls to the vehicle systems 310 and/or peripheral devices 210 may be customized by an operator or administrator, for example.
The HHC 280 may further include a display 505 . The display 505 may be used to display data received by the HHC 280 from the ICS 220 and/or the VSC 230 . For example, the VSC 230 may provide the HHC 280 with information about the vehicle such as speed, temperature, and location. The HHC 280 may display the information to an operator on the display 505 . Alternatively, or additionally the HHC 280 may receive video data from a peripheral device 210 of the ICS 220 and may display the video data to the operator on the display 505 . The display 505 may include a variety of display types including LCD and OLED. Other types of displays may be used.
The HHC 280 may include a variety of sensors 502 . The sensors 502 may include a variety of sensor types including a location determination means such as a GPS, an accelerometer, a gyroscope, thermometer, impedance sensor, camera, fingerprint reader and a light sensor. Other types of sensors may be used. The data from the sensors 502 may be used to implement various safety and security related features.
For example, the sensors 502 may be used to determine if an operator is currently holding the HHC 280 . For example, a sudden large acceleration detected by an accelerometer may indicate that the HHC 280 has been dropped. Similarly, because operators do not typically stand completely still, there is an expected amount of background movement or acceleration that is associated with being held still by an operator. If no acceleration is detected, or the detected acceleration is otherwise outside of this expected amount, then the user may have either placed the HHC 280 down or may otherwise be impaired. If any of the above conditions are detected, then the HHC 280 may be deactivated, or the HHC 280 may send the ICS 220 or VSC 230 a signal to deactivate the vehicle.
In another example, a gyroscope sensor or magnetometer of the HHC 280 may detect the orientation of the HHC 280 and may deactivate the HHC 280 if the orientation is outside of an acceptable range. For example, if the HHC 280 is in an orientation that implies that the operator is lying down, upside down, or in any other unacceptable operating position, the HHC 280 may be deactivated. The ICS 220 and/or VSC 230 may be similarly also be deactivated as a result of the HHC 280 deactivation. The camera, light sensor, and/or impedance sensor may similarly be used to determine if the HHC 280 is being held by a user.
With respect to security, the camera, fingerprint reader, and impedance sensor, alone or in combination, may be used to authenticate an operator of the HHC 280 . If an operator is not an authorized operator, or otherwise cannot be authenticated, the HHC 280 may be disabled along with the associated vehicle.
The processing means 510 may execute software that manages and routes data to and from the various components of the HHC 280 , as well as perform any processing related to the display 505 , sensors 502 , and user controls 540 . For example, the processing means 510 may receive indications of one or more button actuations from the user controls 540 , may determine corresponding commands and/or instructions. These instructions may be then provide to the wireless interface 501 for transmission to the ICS 220 and/or VSC 230 . Similarly, the processing means 510 may receive location or video data from the ICS 220 , and may format or process the received data into a format that is suitable for display on the display 505 . The processing means 510 may further implement the various safety and authentication features described above.
The processing means 510 may further interface with an e-stop controller 530 . The e-stop controller 530 may be mapped to a particular button or switch of the user controls 540 , and when actuated may cause a stop signal to be sent to the processing means 510 . Upon receipt of the stop signal, the processing means 510 may send a corresponding stop signal or instruction via the wireless interface 510 to an associated e-stop 284 of the controlled vehicle. Depending on the implementation, the e-stop controller 530 may include its own processing means and wireless interface so that the other operations of the HHC 280 do not impede or interfere with the operation of the e-stop controller 530 .
FIG. 6 is an illustration of an example e-stop 284 . The e-stop 284 may include a plurality of components including a wireless interface 601 , a hardware fail safe 605 , a software failsafe 606 , a processing means 610 , a locating means 615 , a power supply 608 , and a manual input 609 . More or fewer components may be supported. As described above, an e-stop 284 may be paired with a vehicle, manufacturing device, or other machinery, and may allow one or more users to immediately stop the operation of the paired machinery or vehicle by activating either a button or switch attached to the e-stop 284 , or through one or more wireless e-stop controllers 285 . The e-stop 284 may halt the operation of a vehicle or machinery by sending a stop signal, for example.
The e-stop 284 may include a wireless interface 601 . The wireless interface may include at least one antenna or radio and may be used to receive data from an e-stop controller 285 . A variety of communication standards, protocols, and frequencies such as Wifi, cellular, Bluetooth, 1.3 Ghz, 2.4 Ghz, 5.8 Ghz, and 900 Mhz may be supported by the wireless interface 601 . In some implementations, the e-stop 284 may periodically send a heartbeat signal to the e-stop controller 285 indicating that the e-stop 284 is operating correctly.
To prevent malfunction of the e-stop 284 , the e-stop 284 may include a two stage failsafe system. The system may include the hardware failsafe 605 and the software failsafe 606 . The hardware failsafe 605 may determine whether there is an active connection with the e-stop controller 285 and the e-stop 284 . If at any time the wireless connection between the e-stop controller 285 and the e-stop 284 fails or is interrupted, the hardware failsafe 605 may trigger the stop signal to halt the vehicle or machinery.
The software failsafe 605 may monitor the received signal for one or more of a heartbeat signal and a stop signal from the e-stop controller 285 . If the stop signal is received from the software failsafe may trigger the stop signal to halt the vehicle or machinery. The heartbeat signal may signify that the e-stop controller 285 is operating correctly, thus if the heartbeat signal ceases to be received from the e-stop controller 285 , the software failsafe 605 may similarly trigger the stop signal to halt the vehicle or machinery.
As may be appreciated, the hardware failsafe 605 may allow the e-stop controller 285 to stop the associated vehicle or machinery even where the software failsafe 606 has failed. For example, the e-stop controller 285 may stop receiving the heartbeat signal from the e-stop 284 . Because the heartbeat signal is not being received, there may be a software malfunction of the software failsafe 606 that is preventing the heartbeat signal from being generated. However, because there is a software error, even if the e-stop controller 285 were to send a stop signal to the software failsafe 606 , there is a risk that the software failsafe 606 may not respond correctly. Accordingly, rather than, or in addition to sending the stop signal, the e-stop controller 285 may deactivate the wireless connection between the e-stop controller 285 and the e-stop 284 . The deactivation of the wireless connection will be detected by the hardware failsafe 605 , and may cause the hardware failsafe 605 to trigger the stop signal to halt the vehicle or machinery. Because the hardware failsafe 605 is implemented using hardware, rather than software, the hardware failsafe 605 is not affected by software malfunctions.
The processing means 610 may execute software that manages and routes data to and from the various components of the e-stop 284 , as well as perform any processing related to the software failsafe 605 .
The locating means 615 may determine a current location of the e-stop 284 . The locating means 615 may be implemented using a variety of location determination technologies including GPS. The processing means 610 may use the determined location to perform some additional safety functionality. For example, the e-stop controller 285 may periodically transmit its location to the e-stop 284 . The processing means 610 may compare the location of the e-stop controller 285 with the location of the e-stop 284 and may determine if they exceed a minimum separation distance. And if so, the processing means 610 may trigger the stop signal to halt the vehicle or machinery. Alternatively, the e-stop 285 may provide its location to the e-stop controller 285 , and the e-stop controller 285 may determine if the maximum distance has been exceeded.
The e-stop 284 may further include the power supply 608 . The power supply 608 may be a battery, or may be power received from the associated vehicle or machinery, for example. Any type of battery may be used. In some implementations, the e-stop 284 may trigger the stop signal to halt the vehicle or machinery should the remaining battery fall below a threshold.
The e-stop 284 may further include a manual input 609 . The manual input 609 may be a button, switch or other input means. When actuated, the manual input 609 may trigger the stop signal to halt the vehicle or machinery. The manual input may be implemented using hardware to prevent malfunction in the event of a software failure.
FIG. 7 is an illustration of a system of distributed e-stops 284 and e-stop controllers 285 . As shown the system includes a plurality of e-stops 284 a - d (collectively referred to as e-stops 284 ) and a plurality of e-stop controllers 285 a - c (collectively referred to as e-stop controllers 285 ). While only four e-stops 284 and three e-stops controllers 285 are shown, it is for illustrative purposes only. There is no limit to the number of such devices that may be supported.
As shown, together, the e-stops 284 (and e-stop controllers 285 ) may form a mesh wireless network. When an e-stop controller 285 desires to send a signal (such as a stop signal) to particular e-stop, the controller 285 may send it to any available e-stop 284 , which may then forward the signal to the specified e-stop 285 . For example, a user of the e-stop controller 285 c may wish to stop the machinery associated with the e-stop 284 c. Depending on the implementation, the user may select the e-stop 284 c from a list of e-stops 285 on a display associated with the e-stop controller 285 c, or may actuate an input of the e-stop controller 285 c that has been mapped to the e-stop 284 c. After selecting the e-stop 284 c, the stop signal may be sent to the e-stop 284 d because that is the closest e-stop 284 to the e-stop controller in the mesh network. The e-stop 284 d may then forward the signal to the e-stop 284 c, which may then halt or stop its associated machinery or vehicle. Any system method or technique for mesh networking may be used.
In some implementations, each e-stop controllers 285 may be paired with one or more of the e-stops 284 and may only halt the machinery or vehicle associated with an e-stop 285 that is paired with. Alternatively, one or more of the e-stop controllers 285 may stop any of the e-stops 284 that are available. The e-stop controllers 285 may be manually paired with a particular e-stop 284 by a user or administrator. Alternatively, the e-stop controllers 285 may automatically be paired with the e-stops 284 that they are closest to based on location data associated with the e-stop controllers 285 and the e-stops 284 .
In another implementation, a master e-stop controller 285 may be provided. The master e-stop controller 285 may override the stop signal sent by the other e-stop controllers 285 , and may therefore restart a halted vehicle or machinery. The master e-stop controller 285 may also be able to stop any available e-stop 284 on the network. The master e-stop controller 285 may automatically pair with a closest available mesh network. For example, a foreman may oversee several factories or construction sites. When the foreman visits a site or floor his or her controller 285 may discover the network of e-stops 284 at the site or floor and may immediately be able to halt any of the machines associated with the e-stops 284
In another implementation, the e-stop controllers 285 may be classified as either primary or secondary e-stop controller 285 . Each e-stop 284 may determine, based on location information, if it is within a minimum distance of any secondary e-stop controller 285 . If not, the e-stop 284 may halt its associated machinery. Whereas the primary controller 285 may not be subject to such distance requirements.
For example, workers on a factory floor may be each assigned a secondary e-stop controller 285 , while a foreman on the floor is assigned a primary e-stop controller 285 . Each of the floor workers is tasked with overseeing a particular piece of machinery therefore the e-stops 284 may determine that at least one secondary e-stop controller 285 is within a monitoring distance of the machinery. On the other hand, the foreman may desire to be able to stop the operation of a piece of machinery while on the factory floor, but it is not crucial that he or she always be on the floor or within a particular distance of the e-stops 284 .
FIG. 8 is an illustration of a method 800 implementing semi-autonomous navigation of an unmanned vehicle using the OIP 100 . The method 800 may automatically control the throttle of the unmanned vehicle allowing the user to focus on steering the unmanned vehicle or on operating one or more peripheral devices 210 . Because the user is not controlling the throttle, the functionality of the HHC 280 may be integrated into binoculars, or into a weapon such as rifle. For example, such an HHC 280 may be incorporated into a weapon using a single joystick allowing the user to have their weapon engaged while still controlling the unmanned vehicle. A screen may be provided on the weapon to display received video data from the ICS 220 associated with the vehicle to further assist the user in the control of the vehicle or to identify upcoming threats. The method 800 may be implemented by the ICS 220 and VSC 230 associated with a unmanned vehicle in conjunction with either the HHC 280 or the RVS 260 .
At 801 a current location of an operator may be determined. The operator may be operating the HHC 280 and the current location may be determined by a GPS or other locating means associated with the HHC 280 . The operator of the HHC 280 may be following the vehicle that is being controlled by the HHC 280 . For example, the operator may be in a different vehicle, or may be walking.
At 803 a leading distance between the operator and the unmanned vehicle may be determined. The leading distance may be the desired distance that may be maintained between the unmanned vehicle and the operator. The leading distance may be randomly determined or selected (to confuse possible threats), or may be a fixed distance.
At 805 a current location of the vehicle is determined. The current location may be determined by the locating means associated with either the ICS 220 or the VSC 230 .
At 807 a determination is made as to whether the distance between the current location of the operator and the unmanned vehicle is less than or greater than the leading distance. If the difference is less than the leading distance, then the VCS 230 or the ICS 220 may increase the speed of the vehicle at 807 . If the difference is greater than the leading distance, then the VCS 230 or the ICS 220 may decrease the speed of the vehicle at 809 .
The inherent flexibility of the OIP 100 means that the possibilities for applications are quite numerous. Its ability to be adapted to control many vehicles of varying sizes and different operational environments enables the use of a single platform to develop a wide variety of solutions without needing to support a multitude of systems with redundant development efforts. Examples of such applications follow.
Windowing System
The SCM 240 may provide a unique windowed approach to share control of a vehicle between an operator and an autonomous sensor based algorithm. A window may be a period of time that the HHC 280 is permitted to control the vehicle, and may define a set of allowable controls for the HHC 280 and/or upper or lower bounds on the controls. Outside of the window, the SCM 240 may autonomously control the vehicle. While the operator is using the HHC 280 to drive the vehicle, the SCM 240 may use sensor data and autonomy algorithms to define windows of allowable control commands to the VSC 230 . For example, the operator may instruct the vehicle to drive at a high speed using the HHC 280 , while the autonomy algorithm has determined that danger lies ahead. In response to the danger determination, the SCM 240 may create a window that provides an upper limit for the speed of the vehicle to the VSC 230 to ensure that speed is reduced and a safe speed is used. The VSC 230 may use the defined windows from the SCM 240 to manipulate the vehicle commands from the HHC 280 before ultimately driving the vehicle. If the danger still lies ahead, the SCM 240 may bring the vehicle to a stop or slowly start to steer the vehicle in a safe direction. If the SCM 240 determines that full autonomy is needed to complete a task, it may reduce the allowable window to a single point, thus taking the HHC out of the loop completely.
Safe Takeover
Another example is known as safe takeover. As described above, the OIP 100 allows for a variety unmanned vehicles to be operated remotely by a user through the HHC 280 , even in situations where the user may not have a clear line-of-sight of the unmanned vehicle. Accordingly, a user or administrator may use the OIP 100 to enforce a safety procedure that may be used to verify that the vehicle may be safely operated by the HHC 280 before the OIP 100 allows the HHC 280 to control the vehicle (i.e., takeover).
In one implementation, the OIP 100 may force the user to actuate one or buttons or switches on the vehicle before the VSC 230 or ICS 220 will allow the HHC 280 to control the vehicle. The buttons or switches may be located at different locations on the vehicle to ensure that the user has verified that no lives or property will be damaged by the vehicle. The same takeover sequence may be used for each takeover, or may be randomized. The takeover sequence may be displayed to the user on the display of the HHC 280 . Such a safety procedure may be useful on a construction site or other work environment. The takeover sequence may be customizable by a user or administrator, or may be disabled depending on the implementation.
Training Applications
In some implementations, multiple HHCs 280 may be used to provide training for HHC 280 operators. For example, one HHC 280 may be the “Instructor” controller and another HHC 280 may be a “trainee” controller. The VSC 230 or ICS 220 may receive commands from either the instructor or the trainee controller, but when instructions are received from both controllers, or if there is a conflict between instructions that are received from the controllers, the instructions that are received from the instructor controller are followed.
In another implementation, an instructor may view a video feed from an unmanned vehicle on a personal device through the RVS 260 . The unmanned vehicle may be controlled by a trainee using the HHC 280 . The instructor may use the personal device to provide instructions/and or critiques to the trainee that may be displayed to the trainee on the display of the HHC 280 or on a video feed that the trainee is otherwise viewing. The instructor may use the personal device to disable the unmanned vehicle or to otherwise take control of the vehicle away from the trainee if necessary.
Safety Applications
In another implementation, the ICS 220 may enforce a minimum distance between an unmanned vehicle and other users to ensure the safety of the users. For example, the ICS 220 may determine the distance between the unmanned vehicle and the HHC 280 (via GPS), and may disable the unmanned vehicle if the distance is less than a threshold distance. In another example, workers who operate close to unmanned vehicles may wear wireless sensors. If the ICS 220 determines that such a wireless sensor is within the threshold distance, the ICS 220 may disable the vehicle until the worker with the wireless sensor moves outside of the threshold distance.
Instrument-Aided Precise Manipulation
Integrating high-precision distance sensors into the ICS 220 allows the control of tools with extreme accuracy, even with significant standoff distances. Positioning a sensor on the manipulator arm of a robot gives the operator precise distance feedback between the arm and the object of interest. This simple feedback provides a sense of depth not available on a simple video screen, increasing the precision achievable while also reducing the cognitive workload on the operator.
FIG. 9 shows an exemplary computing environment in which example embodiments and aspects may be implemented. The computing system environment is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality.
Numerous other general purpose or special purpose computing system environments or configurations may be used. Examples of well known computing systems, environments, and/or configurations that may be suitable for use include, but are not limited to, personal computers, server computers, handheld or laptop devices, multiprocessor systems, microprocessor-based systems, network PCs, minicomputers, mainframe computers, embedded systems, distributed computing environments that include any of the above systems or devices, and the like.
Computer-executable instructions, such as program modules, being executed by a computer may be used. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Distributed computing environments may be used where tasks are performed by remote processing devices that are linked through a communications network or other data transmission medium. In a distributed computing environment, program modules and other data may be located in both local and remote computer storage media including memory storage devices.
With reference to FIG. 9 , an exemplary system for implementing aspects described herein includes a computing device, such as computing system 900 . In its most basic configuration, computing system 900 typically includes at least one processing unit 902 and memory 904 . Depending on the exact configuration and type of computing device, memory 1404 may be volatile (such as random access memory (RAM)), non-volatile (such as read-only memory (ROM), flash memory, etc.), or some combination of the two. This most basic configuration is illustrated in FIG. 9 by dashed line 906 .
Computing system 900 may have additional features/functionality. For example, computing system 900 may include additional storage (removable and/or non-removable) including, but not limited to, magnetic or optical disks or tape. Such additional storage is illustrated in FIG. 9 by removable storage 908 and non-removable storage 910 .
Computing system 900 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computing system 1400 and includes both volatile and non-volatile media, removable and non-removable media.
Computer storage media include volatile and non-volatile, and removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Memory 904 , removable storage 908 , and non-removable storage 910 are all examples of computer storage media. Computer storage media include, but are not limited to, RAM, ROM, electrically erasable program read-only memory (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computing system 900 . Any such computer storage media may be part of computing system 900 .
Computing system 900 may contain communications connection(s) 912 that allow the device to communicate with other devices and/or interfaces. Computing system 900 may also have input device(s) 914 such as a keyboard (software or hardware), mouse, pen, voice input interface, touch interface, etc. Output device(s) 916 such as a display, speakers, printer, etc. may also be included. All these devices are well known in the art and need not be discussed at length here.
It should be understood that the various techniques described herein may be implemented in connection with hardware or software or, where appropriate, with a combination of both. Thus, the methods and apparatus of the presently disclosed subject matter, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium where, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the presently disclosed subject matter.
Although exemplary implementations may refer to utilizing aspects of the presently disclosed subject matter in the context of one or more stand-alone computer systems, the subject matter is not so limited, but rather may be implemented in connection with any computing environment, such as a network or distributed computing environment. Still further, aspects of the presently disclosed subject matter may be implemented in or across a plurality of processing chips or devices, and storage may similarly be effected across a plurality of devices. Such devices might include personal computers, network servers, and handheld devices, for example.
Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. | An open architecture control system is provided that may be used for remote and semi-autonomous operation of commercial off the shelf (COTS) and custom robotic systems, platforms, and vehicles to enable safer neutralization of explosive hazards and other services. In order to effectively deal with rapidly evolving threats and highly variable operational environments, the control system is built using an open architecture and includes a high level of interoperability. The control system interfaces with a large range of robotic systems and vehicles, autonomy software packages, perception systems, and manipulation peripherals to enable prosecution of complex missions effectively. Because the control system is open and does not constrain the end user to a single robotics system, mobile platform, or peripheral hardware and software, the control system may be used to assist with a multitude of missions beyond explosive hazard detection and clearance. | 7 |
BACKGROUND OF THE INVENTION
This invention generally relates to a system and method for intercepting rockets, artillery, and mortar for battlefield defense. In particular, the present invention relates to a method and system for neutralizing rockets, artillery, and mortars using a capture sock or net.
Historically, the greatest killer on the battlefield has been rockets, artillery, and mortar, often collectively referred to as RAM. A RAM threat is an extremely difficult target to kill. Using conventional interceptor technology, the interceptor is required to utilize high precision guidance systems to guide the interceptor accurately enough to hit the threat. Moreover, many interceptors utilize warheads to kill the RAM threat and thus require large and sophisticated hardware.
Various guidance systems for interceptors are well-known in the industry. Generally, guidance systems are either “passive”, “active”, or a combination of “active” and “passive.” Passive systems generally collect data from the target for guidance control, and are often referred to as homing guidance. Active systems obtain guidance instructions from a ground based system, for example, a radar tracking station, and are often referred to as command guidance. Any conventional guidance system can be used for the interceptor system and method disclosed herein and the type of guidance system used for any particular application is not a limitation of invention.
Most interceptors also utilize some type of steering device that allows the trajectory and flight of the interceptor to be altered during flight. Steering devices, and the guidance systems that control the steering devices, are well known in the industry. Any conventional steering device can be used for the interceptor system and method disclosed herein and the type of steering mechanism used for any particular application is not a limitation of the invention.
Some existing interceptors incorporate devices and systems to increase the interceptor's ability to hit the RAM threat. For example, the interceptor may incorporate an explosive warhead that detonates when the interceptor is in close proximity to the RAM, destroying the RAM in the blast. Alternatively, the interceptor may deploy a “fan” or “blades”, for example steel blades, to increase the coverage area of the interceptor when it encounters the RAM.
Even when an interceptor hits a RAM, it is extremely difficult to disable or destroy the RAM. For example, the thick case of the mortar and artillery rounds require large amounts of energy transfer from the interceptor in order to effect a “kill” that renders the unit harmless. Unfortunately, in some circumstances when a RAM is “killed”, shrapnel or debris from the RAM or the interceptor may still cause collateral damage.
Thus the success of the battle is often decided by economics—the cost and size of the interceptor and supporting fire control components are very high making the cost per RAM kill unacceptable. Indeed, as the acceptable miss distance of a particular intercept system (i.e., how close the interceptor must come to the RAM to enable it to destroy or disable the RAM) decreases, the cost of the intercept system goes up exponentially due to the complexity and sophistication of the guidance componentry. The enemy's ability to proliferate the low-cost, low complexity RAM threat easily counters a defense capability that is complex and expensive.
It is, therefore, desirable to provide a RAM neutralization system and method that increases the acceptable miss distance of an intercept system and requires less expensive guidance systems. It is further desirable to provide a RAM neutralization system and method that does not need to actually hit the RAM in order to neutralize it. It is further desirable to provide an RAM neutralization system and method that does not require the RAM to be detonated in order to be neutralized.
SUMMARY OF THE INVENTION
The present invention recognizes and addresses various of the foregoing limitations and drawbacks, and others, regarding RAM intercept and neutralization systems and methods. Therefore, the present invention is directed to a RAM neutralization system and method that has a relaxed guidance precision requirement and provides more opportunity to destroy or mitigate the RAM threat.
In one embodiment, the invention is directed to a system for neutralizing an enemy weapon comprising an interceptor launched toward an approaching enemy weapon and a deployable net attached to the interceptor, said net being deployed from the interceptor prior to the interceptor encountering the enemy weapon to capture the enemy weapon.
In another embodiment, the invention is directed to a method of neutralizing an airborne enemy weapon comprising launching an interceptor toward an approaching airborne enemy weapon, said interceptor having a deployable capture sock, deploying the capture sock prior to the interceptor encountering the airborne enemy weapon, and capturing the airborne enemy weapon in the capture sock.
In another embodiment, the invention is directed to a weapon defense system for neutralizing an approaching airborne enemy weapon comprising an interceptor housing a deployable capture sock, wherein the interceptor is launched toward the airborne enemy weapon and deploys the capture sock to capture the airborne enemy weapon.
It is, therefore, a principle object of the subject invention to provide a cost-effective RAM neutralization system and method. More particularly, it is an object of the present invention to provide a RAM neutralization system and method that does not necessarily require high guidance precision. It is another object of the invention to provide for expanded options for destroying or mitigating the RAM threat. It is a further object of the invention to minimize the collateral damage associated with neutralizing a RAM threat.
Generally, the novel RAM neutralization system and method disclosed herein is used in connection with well-known intercept vehicles, guidance systems, and steering devices. When an RAM threat is identified, an interceptor is launched. Those of skill in the art will appreciate and recognize the appropriate intercept vehicles, guidance systems, and steering devices that may be best utilized. Unlike the prior art RAM neutralizing systems and methods, however, the present invention utilizes a capture sock or net to neutralize the RAM. The intercept vehicle includes a capture sock that is deployed just before the intercept vehicle encounters the RAM, the RAM is captured or diverted, and the threat neutralized.
Additional objects and advantages of the invention are set forth in, or will be apparent to those of ordinary skill in the art from, the detailed description as follows. Also, it should be further appreciated that modifications and variations to the specifically illustrated and discussed features and materials hereof may be practiced in various embodiments and uses of this invention without departing from the spirit and scope thereof, by virtue of present reference thereto. Such variations may include, but are not limited to, substitutions of the equivalent means, features, and materials for those shown or discussed, and the functional or positional reversal of various parts, features, or the like.
Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of this invention, may include various combinations or configurations of presently disclosed features, elements, or their equivalents (including combinations of features or configurations thereof not expressly shown in the figures or stated in the detailed description).
These and other features, aspects and advantages of the present invention will become better understood with reference to the following descriptions and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the descriptions, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
FIG. 1 is a depiction of an interceptor and separated main propulsion stage approaching a RAM threat;
FIG. 2 is a depiction of one embodiment of the capture sock being deployed;
FIG. 3 is a depiction of one embodiment of the capture sock after full deployment;
FIG. 4 is a depiction of one embodiment of the capture sock as the RAM is captured by the capture sock;
FIG. 5 is a depiction of one embodiment of the capture sock using an active destruct mechanism to neutralize the RAM;
FIG. 6 is a depiction of one embodiment of the capture sock altering the trajectory of the captured RAM;
FIG. 7 is a depiction of one embodiment of the capture sock and interceptor utilizing a parachute and/or additional thrust mechanism in the interceptor to alter the trajectory of the captured RAM;
FIG. 8 is a depiction of one embodiment wherein the main propulsion stage and the capture sock remain connected to the interceptor; and
FIG. 9 is a depiction of one embodiment utilizing energy absorption devices to decelerate the RAM, consisting of FIG. 9 a at the point of capture, and FIG. 9 b showing ductile coils plastically deforming to absorb the energy of capture.
Repeat use of reference characters throughout the present specification and appended drawings is intended to represent the same or analogous features or elements of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to presently preferred embodiments of the invention, examples of which are fully represented in the accompanying drawings. Such examples are provided by way of an explanation of the invention, not limitation thereof. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention, without departing from the spirit and scope thereof. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Still further, variations in selection of materials and/or characteristics may be practiced, to satisfy particular desired user criteria. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the present features and their equivalents.
As disclosed above, the present invention is particularly concerned with a RAM neutralization system and method that utilizes a capture net or sock. As depicted in FIG. 1 , a RAM 1 is identified utilizing conventional technology and an interceptor 2 is launched or fired. Again, various interceptors are known in the art and the specific type of interceptor that may be utilized is not a limitation of the invention. One type of interceptor utilizes a main propulsion stage 6 , or booster, that accelerates the interceptor 2 toward the RAM 1 . The main propulsion stage 6 is normally disengaged, falls off the main interceptor casing, or the main propulsion ceased. The interceptor 2 utilizes well known, and conventional, guidance and steering systems to track and intercept the RAM 1 .
As depicted in FIG. 2 , as the interceptor 2 approaches the RAM 1 , the interceptor 2 deploys a capture sock 3 , or net, just before intercept. In the preferred embodiment, the deployed capture sock 3 is connected to the interceptor 2 by tethers 4 , although other connections are contemplated. In the preferred embodiment, the capture sock 3 has a net-like structure having webbing dense enough to at least temporarily capture the RAM 1 , but with sufficient spacing to minimize drag. Preferably, the capture sock 3 is made of any sufficiently strong material to capture the RAM 1 without breaking. Preferred embodiments of the capture sock material are made of Kevlar®. The spacing of the capture sock webbing will depend on the specific type of RAM to be neutralized. For example, for artillery and mortars, the spacing may be significantly more dense than for neutralizing rockets because rockets are traditionally larger in size.
The deployment of the capture sock 3 may be by any conventional means. When deployed in this embodiment, the capture sock 3 has sufficient drag such that the movement of the air through the capture sock 3 will cause the capture sock 3 to naturally expand to its full volume (see FIG. 3 ). Alternative active mechanisms may also be utilized to assist the capture sock 3 in expanding, either upon deployment or some other desired time.
The capture sock 3 preferably is in the shape of a tapered cone, such that the opening closest to the interceptor 2 has a larger diameter than the capture point. Alternative configurations of the capture sock 3 may also be used. Indeed, the capture sock, or net, could simply be a two-dimensional web rather than a three-dimensional cone having a length. The size and shape of the capture sock opening is not fixed, and may depend on the specific type of RAM threat being neutralized, the accuracy of the guidance systems being utilized, and the drag of the capture sock 3 when deployed. The larger the capture sock opening, the greater likelihood of capture. However, the larger the capture sock opening, the more drag the interceptor 2 will likely experience when the capture sock 3 is deployed, and the ability to guide the interceptor 2 will decrease.
If the RAM 1 is directly hit by the interceptor 2 , the RAM 1 will likely be disabled or destroyed, and the RAM 1 will not likely hit its intended target. Thus, the present system and method may be used in connection with other neutralization systems. If the RAM 1 is not directly hit by the interceptor 2 , the relatively large opening of the capture sock 3 allows the present system to nevertheless “neutralize” a RAM 1 even when a direct hit is not achieved. Thus, the present system need not be as highly accurate as the prior art systems.
As depicted in FIG. 4 , the RAM 1 passes through the capture sock opening and into the capture sock 3 . In the preferred embodiment, the RAM 1 will be contained within the capture sock 3 and will preferably travel to the “closed” end of the capture sock 3 . The “closed” end need not be completely closed, but should have webbing sufficiently dense to capture the RAM 1 to be neutralized. For clarity the term “capture” means that the weapon to be neutralized passes through the open end of the capture sock, or otherwise contacts the net. As discussed below, it may be temporarily or permanently captured.
A RAM 1 may be neutralized even if the system does not permanently capture the RAM 1 in the “closed” end of the capture sock 3 as designed. For example, the RAM 1 could detonate when it encounters sufficient resistance in the capture sock 3 before it reaches the “closed” end. Moreover, even if the RAM 1 pierces the capture sock 3 or encounters the capture sock 3 but is nevertheless able to pass through one of the openings in the capture sock webbing, the RAM 1 will often be “neutralized” because the trajectory of the RAM 1 will likely be sufficiently altered so that the RAM 1 does not hit its intended target.
In the preferred embodiment, the RAM 1 will be permanently captured in the capture sock 3 and will travel to the “closed” end of the sock. Again, the “closed” end of the sock preferably has dense enough webbing in the capture sock material so that the RAM 1 does not pass through. Preferably, the material of the capture sock 3 is strong enough to not break when the RAM 1 is encountered. Even if the material is broken, the trajectory of the RAM 1 will likely have been sufficiently altered so that the RAM does not hit its intended target.
Some RAMs 1 initiate a fuse upon an impact and detonate shortly thereafter. Thus, some RAMs 1 may detonate upon impact of the RAM 1 in the sock, particularly in the “closed” end of the sock 3 . The “closed” end of the sock may also contain a material different from the webbing of the capture sock 3 that facilitates detonation of the RAM 1 when it hits the “closed” end of the sock 3 .
When the RAM 1 is captured, and the capture sock 3 is not pierced, the trajectory of the RAM 1 (now in the capture sock) is significantly affected as depicted in FIG. 6 . The capture sock 3 may remain connected to the interceptor 2 or it may be designed to break away from the interceptor. Either way, the RAM 1 will not hit its intended target. This is one way to neutralize the RAM threat. The neutralization system and method may also utilize additional mechanisms to further neutralize the threat. For example, the interceptor 2 may also use a parachute 5 that is deployed that will further alter the trajectory of the RAM 1 after it is captured (see FIG. 7 ). Similarly, the capture sock 3 could also be designed to deploy a parachute upon capture of the RAM 1 . The interceptor 2 may also utilize additional propulsion to further alter the trajectory of the captured RAM 1 (see FIG. 7 ). These two additional embodiments could be used together, separately, or not at all. Any additional mechanisms which alter the trajectory of the captured RAM 1 may also be used and are within the scope of the invention.
Additional embodiments can be utilized that actively seek to disable or destroy the RAM 1 . In one embodiment, the closed end of the capture sock 3 may contain an active destruct mechanism 7 that can further neutralize the RAM 1 (see FIG. 5 ).
Another embodiment is depicted in FIG. 8 . In this embodiment, the main propulsion stage 6 , or booster, is not totally disengaged, but rather remains connected to the interceptor 2 . Depicted in FIG. 8 is one embodiment showing use of an interceptor 2 /booster 6 tether 8 that extends to approximately the closed end of the sock. The capture sock 3 is deployed as discussed above. Thus, both the capture sock 3 and the main propulsion stage 6 are connected to the interceptor 2 . In the preferred embodiment, the “closed end” of the capture sock 3 terminates into the connected main propulsion stage 6 . This embodiment has two advantages. First, the presence of the main propulsion stage 6 provides a solid “structure” that will likely detonate the RAM 1 when the RAM 1 contacts it. Second, the main propulsion stage 6 may also contain a separate warhead or explosive device to actively detonate the RAM 1 .
As depicted in FIG. 9 , alternative embodiments also include the use of one or more energy absorption devices 9 , for example, a coil. The energy absorption devices 9 could be utilized in connection with the capture sock 3 such that when the RAM 1 is captured, the capture sock 3 and its tethers 4 are used to decelerate the RAM 1 through the use of the energy absorption devices 9 . For example, the tethers 4 could utilize one or more ductile coils in the connection to the interceptor 2 that plastically deform to absorb energy of capture (See FIG. 9 ). Alternatively, the portion of the interceptor 2 which houses the capture sock 3 could be connected to the main interceptor housing the coils, and as the RAM 1 is captured, the capture sock housing separates and decelerates the RAM 1 as the coils connecting the two housings extend.
Benefits of the capture sock include: (1) the requirement for high guidance precision to hit the target is considerably relaxed since the presented area of the sock opening allows for a larger miss distance; (2) capture and confinement of the RAM in the capture sock provides more opportunity to destroy or mitigate the RAM threat; (3) confinement in the sock presents opportunity to minimize collateral damage associated with defeating the RAM threat; and (4) visual confirmation that a RAM has been neutralized. The invention may greatly reduce the cost to kill a RAM threat by utilizing less expensive guidance hardware yet neutralizing various RAM threats.
Although a preferred embodiment of the invention has been described using specific terms and devices, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention, which is set forth in the following claims. In addition, it should be understood that aspects of various other embodiments may be interchanged both in whole or in part. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred version contained herein. | An article for neutralizing an enemy weapon comprising an interceptor and a deployable net attached to the interceptor, said deployable net remaining attached to the interceptor upon deployment, is disclosed. A method of neutralizing an airborne enemy weapon comprising launching an interceptor, with a capture sock, towards the enemy weapon and deploying the capture sock just prior to the interceptor encountering the enemy weapon is also disclosed. The capture sock remains attached to the interceptor upon deployment. | 5 |
FIELD OF THE INVENTION
This invention relates to a printing apparatus and printing method, and particularly to a printing method and printing apparatus which time-divisionally drive a printhead for printing in accordance with, e.g., an inkjet method and print a halftone image.
BACKGROUND OF THE INVENTION
There have conventionally been proposed, e.g., a wire dot method, a thermal method, a thermal transfer method, and an inkjet method as printing methods of printing apparatuses which print on a printing medium such as paper or a plastic sheet. Of these printing apparatuses, a printing apparatus (inkjet printing apparatus) which adopts the inkjet method of discharging ink from a discharge orifice to print on a printing medium achieves quiet non impact printing and can print at high density and high speed.
Recently, printing at higher speeds and higher densities are required. To meet this demand, a printhead (to be referred to as an inkjet printhead hereinafter) mounted in an inkjet printing apparatus generally has many discharge orifices for discharging ink. Some discharge methods for the inkjet printhead utilize, as ink discharge energy, abrupt ink bubbling upon driving a heating element (to be also referred to as a nozzle heater hereinafter) such as an electrothermal transducer arranged in the discharge orifice. Some discharge methods utilize contraction upon driving a piezoelectric element attached to a nozzle.
Regardless of the employed method, discharge becomes unstable due to pressure interference (crosstalk) between adjacent nozzles when all printing elements are concurrently driven in printing. In addition, a voltage drop by power loss on a common power line becomes large near the printhead owing to a large current. As the number of concurrently driven nozzles increases, the driving voltage applied to a nozzle heater drops much more, and printing stability is impaired. Further, the design of a compact, low cost apparatus is limited such that a power supply sufficient to resist an instantaneous large current is required. This problem is solved by dividing all nozzles into a plurality of blocks each having several to several ten nozzles in an inkjet printhead and sequentially time divisionally driving nozzles in the respective blocks. This driving method is called time divisional driving or block divisional driving.
FIG. 9 is a block diagram showing a general configuration of the driving circuit of an inkjet printhead (to be referred to as a printhead hereinafter) using the time-divisional driving method.
In FIG. 9 , M printing elements R 01 to RM are commonly connected to a driving voltage VH at one end, and to an M-bit driver 301 at the other end. The M-bit driver 301 receives AND signals of an output signal from an M-bit latch 302 and block enable selection signals (BE 1 to BEN) of N bits. The M-bit latch 302 receives signals of M bits output from an M-bit register 303 . When a latch signal (LAT) is supplied to the latch circuit, the M-bit latch 302 latches (records and holds) M-bit data stored in the M-bit register 303 . The M-bit shift register 303 is a circuit which aligns and stores image data in correspondence with printing elements. The shift register receives image data which is sent via a signal line S_IN in synchronism with an image data transfer clock (SCLK).
In the driving circuit having the above configuration, time-divisional driving signals are sequentially input as the block enable selection signals (BE 1 to BEN) to time-divisionally drive N printing elements in respective blocks. That is, a plurality of printing elements of the printhead are divided into a plurality of blocks and time-divisional driven to print.
When the number of time-divisionally driven blocks is large, it is known to attach a block enable selection decoder in order to decrease the number of input signals.
When the number of printing elements in a block is set to N for M nozzles, a signal output from the block enable selection decoder can be formed from (MIN) bits. The relationship between the MIN value and the number (X) of terminals of the block enable selection decoder is
Time-Divisional Count (Block Count) NN=M/N=2X The number of enable terminals can be decreased from M/N to X.
However, when the printhead having printing elements arranged on the same line is time-divisional driven block by block, the printing position shifts between blocks because the carriage which supports the printhead moves in the scanning direction. The shift in printing position between blocks becomes large in a printhead which has many blocks and is equipped with the above-mentioned block enable selection decoder.
In order to solve this problem, for example, Japanese Patent Publication For Opposition No. 3-208656 proposes a sequential distribution driving method which prevents the printing shift between blocks by using a printhead configured by inclining a printing element array from the carriage moving direction.
In general, however, the same printhead is driven at various driving frequencies in accordance with the printing mode or a printing apparatus on which the printhead is mounted. For this reason, in a printhead which has many blocks and is equipped with the block enable selection decoder, the highest driving frequency must be assumed to determine the number of blocks. In this case, the method disclosed in Japanese Patent Publication For Opposition No. 3-208656 cannot be used.
As a method of preventing a shift in printing position even in this case, Japanese Patent Publication Laid Open No. 7-323612 discloses a method of divisionally driving printing elements in correspondence with the moving speed when the printhead is scanned.
Japanese Patent Publication Laid Open No. 2001-347663 proposes a printhead in which printing elements are arranged by shifting their positions in consideration of the printing position by time-divisional driving.
In the printing field, a technique of performing digital-halftoning (pseudo-halftoning), i.e., forming a unit matrix (image processing control unit of M×N pixels) from dots in order to implement high-quality printing is well known. In electrophotography, clustered-dot digital-halftoning of fatting dots as the density increases from the center of a matrix used for printing is known particularly as a means for improving color reproducibility of a color image (see, e.g., Japanese Patent No. 2553045). Also in inkjet printing, there is known a technique of improving the image quality by performing digital-halftoning control in a halftone or clustered-dot unit matrix. Examples of this technique are disclosed in Japanese Patent Publication Laid Open Nos. 7-232434, 11-5298, 2000-118007, 2000-198237, 2000-350026, and 2002-29097.
However, these prior art techniques suffer the following problems when printing is done by time divisional driving in digital halftoning by the above mentioned unit matrix.
FIG. 10 is a schematic view showing the relationship between the nozzle array of a printhead, a driving signal for each nozzle, and a dot which is discharged from each nozzle and attached onto a printing medium.
An example shown in FIG. 10 is 1-pass printing in a serial inkjet printing apparatus which prints by reciprocating a carriage which supports a printhead.
As shown in a of FIG. 10 , a nozzle array 500 of the printhead is divided into 86, first to 86th sections each having six nozzles from the top of FIG. 10 . Each of six nozzles in each section belongs to one of six driving blocks, and the nozzles of the respective blocks are time-divisionally driven in printing. That is, nozzles in the same block are concurrently driven.
In the example shown in FIG. 10 , all nozzles are periodically assigned to driving blocks such that the first, seventh, 13th, 19th, . . . nozzles of the nozzle array 500 are assigned to the first driving block, and the second, eighth, 14th, 20th, . . . nozzles are assigned to the second driving block. The first to sixth driving blocks are sequentially driven in ascending order by a pulse-like driving signal 300 shown in b of FIG. 10 . As shown in c of FIG. 10 , dots 100 are formed from the nozzles onto a printing medium in correspondence with the driving signal.
At this time, the unit matrix size is 8×8. As is apparent from c of FIG. 10 showing the attaching position of an ink droplet, the shape of a dot cluster which forms a unit matrix changes depending on the printing position due to the relationship between time-divisional driving and the unit section size.
The shape difference is generated because the section size is “6” and the unit matrix size in the nozzle array direction is “8” in the example shown in FIG. 10 . More specifically, patterns of different shapes each in a predetermined period shorter than the period of the unit matrix in the nozzle array direction are repetitively formed in a predetermined period of 24 pixels which is the least common multiple of “6” and “8”. In this manner, the shape of a dot cluster in each unit matrix periodically changes owing to the relationship between the unit matrix size and the unit section size of time-divisional driving. The periodical change appears as periodical density unevenness to the eye, degrading the image quality.
Since the shape of each unit matrix changes depending on the printing position, ink droplets which form adjacent unit matrices come into contact with each other on a printing medium particularly in high speed printing to degrade the image quality with a higher probability, in comparison with a case wherein dot clusters of the same shape are formed.
For this reason, it is desired to form dot clusters of the same shape in unit matrices regardless of the image printing position.
This problem occurs not only in 1-pass printing by the serial printing apparatus. For example, even multi-pass printing or a printing apparatus which supports a full-line type printhead may pose the same problem depending on the relationship between the unit matrix size and the unit section size of time-divisional driving, degrading the image quality.
SUMMARY OF THE INVENTION
Accordingly, the present invention is conceived as a response to the above-described disadvantages of the conventional art.
For example, a printing method and printing apparatus using the printing method according to the present invention are capable of preventing generation of periodical density unevenness and printing at high image quality.
According to one aspect of the present invention, preferably, there is provided a printing apparatus which uses a printhead having a plurality of printing elements, divides the plurality of printing elements into a plurality of blocks, time-divisionally drives the plurality of printing elements, and prints a halftone image on a printing medium in accordance with a result obtained by performing digital-halftoning for input multi-valued image data in each matrix of a predetermined size, comprising: scanning means for reciprocally scanning the printhead; convey means for conveying the printing medium in a direction different from a scanning direction of the printhead; and printing control means for controlling to print a halftone image in each matrix, wherein an arrayed direction of the plurality of printing elements is a convey direction of the convey means, and the printing control means controls printing of the halftone image so as to set a size of the block to be equal to or an integral multiple of a size of the matrix in the convey direction.
The digital-halftoning may include clustered-dot digital-halftoning of fatting dots as a density expressed by the multi-valued image data increases from a center of the matrix, or dispersed-dot digital-halftoning of discretely increasing the number of dots as a density expressed by the multi-valued image data increases from a center of the matrix.
The printing control means may control to perform multi-pass printing.
The printhead preferably includes an inkjet printhead which prints by discharging ink onto a printing medium.
The inkjet printhead desirably comprises an electrothermal transducer for generating thermal energy to be applied to ink, in order to discharge ink by using thermal energy.
According to another aspect of the present invention, preferably, there is provided a printing method for a printing apparatus which uses a printhead having a plurality of printing elements, divides the plurality of printing elements into a plurality of blocks, time-divisionally drives the plurality of printing elements, and while reciprocally scanning the printhead, prints a halftone image on a printing medium in accordance with a result obtained by performing digital-halftoning for input multi-valued image data in each matrix of a predetermined size, comprising: setting an arrayed direction of the plurality of printing elements to a convey direction of the printing medium; and setting a size of the block to be equal to or an integral multiple of a size of the matrix in the convey direction, and controlling printing of the halftone image in each matrix.
The invention is particularly advantageous since generation of periodical density unevenness can be prevented and a halftone image can be printed at high image quality.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a plan view showing the schematic configuration of an inkjet printing apparatus as a typical embodiment of the present invention;
FIG. 2 is a schematic view showing an example of the nozzle layout of a printhead which is mounted on the inkjet printing apparatus shown in FIG. 1 ;
FIG. 3 is a block diagram showing the control configuration of the inkjet printing apparatus shown in FIG. 1 ;
FIG. 4 is a schematic view showing the relationship between the nozzle array of a printhead according to the first embodiment of the present invention, a driving signal for each nozzle, and a dot which is discharged from each nozzle and attached onto a printing medium;
FIG. 5 is a view showing an example of a clustered-dot matrix;
FIG. 6 is a schematic view showing the relationship between the nozzle array of a printhead according to the second embodiment of the present invention, a driving signal for each nozzle, and a dot which is discharged from each nozzle and attached onto a printing medium:
FIG. 7 is a schematic view showing the relationship between each scanning by a printhead and the image position according to the third embodiment of the present invention;
FIG. 8 is a view showing a checkered mask pattern according to the third-embodiment of the present invention;
FIG. 9 is a block diagram showing a general configuration of the driving circuit of an inkjet printhead using the time-divisional driving method; and
FIG. 10 is a schematic view showing the relationship between the nozzle array of a printhead, a driving signal for each nozzle, and a dot which is discharged from each nozzle and attached onto a printing medium.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in detail in accordance with the accompanying drawings.
In this specification, “printing” (to be also referred to as “print”) is not limited to the formation of significant information such as a character or figure. In addition, in a broad sense, “printing” refers to the forming of an image, design, pattern, or the like on a printing medium or the processing of a medium regardless of whether information is significant or insignificant, or whether information is so visualized as to allow the user to visually perceive it.
“Printing media” are not only paper used in a general printing apparatus, but also ink-receivable materials such as cloth, plastic film, metal plate, glass, ceramics, wood, and leather in a broad sense.
“Ink” (to be also referred to as “liquid”) should be interpreted as widely as the definition of “printing (print)”. “Ink” represents a liquid which is applied onto a printing medium to form an image, design, pattern, or the like, to process the printing medium, or to contribute to ink processing (e.g., solidification or insolubilization of a coloring material in ink applied to a printing medium).
“Nozzles” comprehensively mean discharge orifices or liquid channels which communicate with them, and elements which generate energy used to discharge ink, unless otherwise specified.
FIG. 1 is a plan view showing the schematic configuration of an inkjet printing apparatus (to be referred to as a printing apparatus hereinafter) as a typical embodiment of the present invention.
As shown in FIG. 1 , four inkjet printheads (to be referred to as printheads hereinafter) 21 - 1 to 21 - 4 are mounted on a carriage 20 , and each printhead has an array of nozzles for discharging ink. These printheads will be generally referred to by reference numeral “ 21 ”.
FIG. 2 is a view showing an example of the nozzle layout of the printhead 21 .
The printheads 21 - 1 to 21 - 4 respectively discharge black (K), cyan (C), magenta (M), and yellow (Y) inks, and each nozzle discharges an ink droplet of 2 pl on average. As shown in FIG. 2 , each printhead has four 600-dpi nozzle arrays on which nozzle positions shift from each other at ¼ of the nozzle interval. Thus, each of the printheads 21 - 1 to 21 - 4 has nozzle arrays which are arrayed at a resolution of substantially 2,400 dpi.
In FIG. 2 , the X direction is the scanning direction of the carriage 20 which supports the printhead, and also a direction in which an image is printed by discharging ink droplets from nozzles on the basis of image information while the carriage 20 is scanned on a printing medium. The Y direction is a direction in which nozzle arrays are arranged like columns. Each printhead is formed from four nozzle arrays in this example, but may be formed from one or a plurality of arrays. Also, nozzles need not be aligned.
Referring back to FIG. 1 , a heating element (electrothermal transducer) which generates thermal energy for discharging ink is arranged in the ink discharge orifice (fluid channel) of the printhead 21 . The printheads 21 - 1 to 21 - 4 respectively comprise ink tanks 22 - 1 to 22 - 4 which supply inks. Each printhead and each ink tank form an ink cartridge, which is not denoted by any reference numeral.
A control signal to the printhead 21 is sent via a flexible cable 23 . A printing medium 24 (e.g., plain paper, high-quality dedicated paper, an OHP sheet, glossy paper, a glossy film, or a postcard) passes through a convey roller (not shown), is clamped by a pair of delivery rollers 25 which face each other, and fed in a direction (sub-scanning direction) indicated by the arrow along with driving of a convey motor 26 .
The carriage 20 is movably supported by guide shafts 27 and a linear encoder 28 . The carriage 20 is driven by a carriage motor 30 via a driving belt 29 , and reciprocates in a direction (main scanning direction) which intersects (perpendicular to) the sub-scanning direction along the guide shafts 27 . In reciprocation, the linear encoder 28 outputs a pulse signal, and the position of the carriage 20 can be detected by counting pulse signals.
The heating element of the printhead 21 is driven on the basis of a printing signal along with movement of the carriage 20 . Then, an ink droplet is discharged and attached onto a printing medium to form an image.
In the main scanning direction in which printing is done on a printing medium, a recovery unit 32 having a capping unit 31 is arranged at the home position of the carriage 20 that is set outside the printing area. While no printing is done, the carriage 20 is moved to the home position and the ink discharge orifices of the printheads 21 are closed by corresponding caps 31 - 1 to 31 - 4 of the capping unit 31 . This prevents an increase in ink viscosity caused by evaporation of the ink solvent, fixation of ink, or clogging by attachment of a foreign matter such as dust.
The capping function of the capping unit 31 is exploited to preliminarily discharge ink from an ink discharge orifice to the capping unit 31 at a distant position in order to prevent a discharge failure and clogging at an ink discharge orifice whose printing frequency is low. This function is also exploited to operate a pump (not shown) while capping the printhead, suck ink from the ink discharge orifice, and recover the discharge function of a discharge orifice from a discharge failure.
An ink receiving unit 33 is used to perform preliminary discharge when the printheads 21 - 1 to 21 - 4 pass above the ink receiving unit 33 immediately before printing is arranged at a position adjacent to the capping unit 31 . The ink discharge orifice formation surface of the printhead 21 can be cleaned by arranging a wiping member (not shown) such as a blade at a position adjacent to the capping unit 31 .
Note that the inkjet printing method applicable to the present invention is not limited to a bubble-jet method using a heating element (heater). For example, for a continuous printing method of continuously injecting particles of ink droplets, a charge control method, divergence control method, and the like can be applied. For an on-demand printing method of discharging ink droplets, as needed, a pressure control method of discharging ink droplets from orifices by mechanical vibrations of a piezoelectric vibrator can also be applied.
FIG. 3 is a block diagram showing the control configuration of the printing apparatus shown in FIG. 1 .
In FIG. 3 , reference numeral 1 denotes an image data input unit which receives multi valued image data from an image input device such as a scanner or digital camera, or multi valued image data saved in the hard disk of a personal computer or the like. Reference numeral 2 denotes an operation unit having various keys used to set various parameters and designate the start of printing; and 3 denotes a CPU serving as a control means for performing various arithmetic processes and control operations (to be described later) in accordance with various programs in a storage medium.
Reference numeral 4 denotes a storage medium which stores a control program and error processing program for controlling the printing apparatus. All printing operations in the embodiment are executed by these programs. The storage medium 4 which stores the programs can be, e.g., a ROM, FD, CD-ROM, HD, memory card, or magneto-optical disk. Reference numeral 5 denotes a RAM which is used as a work area for various programs in the storage medium 4 , a temporary save area in error processing, and a work area in image processing. The RAM 5 is also used when various tables stored in the storage medium 4 are copied in the RAM 5 , then the contents of the tables are changed, and image processing proceeds by referring to the changed tables.
Reference numeral 6 denotes an image data processing unit which processes image data. The image data processing unit 6 quantizes input multi-valued image data into N-ary image data for each pixel, and generates discharge pattern data corresponding to a gray value “T” represented by each quantized pixel. For example, when multi-valued image data expressed by 8 bits (256 gray levels) for each color component of one pixel is input to the image input unit 1 , the image data processing unit 6 in the embodiment converts the gray levels of output image data into 25 (=24+1) gray levels. In the embodiment, T-ary processing for input multi-valued image data adopts the multi-valued error diffusion method. However, the image processing method of performing T-ary processing is not limited to the multi-valued error diffusion method, and may employ an arbitrary halftoning method such as the average density conservation method or dither matrix method. By repeating T-ary processing for all pixels on the basis of density information of the image, binary driving signals representing whether to discharge ink or not are formed for pixels corresponding to ink nozzles.
Reference numeral 7 denotes a printing unit which discharges ink on the basis of the discharge pattern created by the image data processing unit 6 , and forms a dot image on a printing medium. The printing unit 7 is formed from the mechanism as shown in FIG. 1 and the like. Reference numeral 8 denotes a bus line which transfers an address signal, data, control signal, and the like in the printing apparatus.
Several embodiments of image processing which is executed using a printing apparatus having the above-described configuration as a common embodiment will be explained.
First Embodiment
A case wherein 1-pass printing is performed by a printhead which substantially has 512 nozzles on one array at a printing resolution of 2,400 dpi and an average discharge amount of 2 pl in the nozzle configuration as shown in FIG. 2 will be described.
FIG. 4 is a schematic view showing the relationship between the nozzle array of the printhead according to the first embodiment of the present invention, a driving signal for each nozzle, and a dot which is discharged from each nozzle and attached onto a printing medium.
In the example shown in FIG. 4 , all the 512 nozzles are periodically assigned to driving blocks such that 64, first, ninth, 17th, 25th, . . . , and 505th nozzles of a nozzle array 500 are assigned to the first driving block, and 64, second, 10th, 18th, 26th, . . . , and 506th nozzles are assigned to the second driving block.
The first to eighth driving blocks are sequentially driven in ascending order by a pulse-like driving signal 300 shown in b of FIG. 4 . As shown in c of FIG. 4 , dots 100 are formed from the nozzles onto a printing medium in correspondence with the driving signal.
At this time, the unit matrix size is 8×8. Since the resolution of the printhead is 2,400 dpi, the resolution of the unit matrix is 300 dpi. In the first embodiment, the unit matrix undergoes clustered-dot digital-halftoning of fatting dots from the center of the matrix as the density increases. In this case, the unit matrix can express 65 gray levels.
FIG. 5 is a view showing an example of a clustered-dot matrix.
According to the first embodiment, as is apparent from c of FIG. 4 showing the printing position of an ink droplet, dot clusters which form unit matrices have the same shape regardless of the position even in time-divisional driving.
In this case, the section size is “8”, and the unit matrix size in the nozzle array direction is “8”. The least common multiple is 8, and the period of eight pixels, i.e., the value of the period coincides with the unit matrix size. For this reason, no patterns of different shapes each in a predetermined period shorter than the period of the unit matrix in the nozzle array direction are repetitively formed, unlike the prior art.
Since dot clusters of the same shape are regularly formed at pixel positions, degradation of the image quality under the influence of dots attached on a printing medium particularly in high-speed printing is suppressed in comparison with a conventional case wherein patterns of different shapes are repetitively formed.
As described above, according to the first embodiment, dot clusters of the same shape are formed in unit matrices. Periodical density unevenness can be prevented, an adverse effect between dots attached on a printing medium can be reduced, and high image quality can be implemented.
Second Embodiment
A case wherein the unit matrix size is 16×16 and the printing resolution of the unit matrix is 150 dpi will be described. In this case, graininess is lower than that in the first embodiment. However, each unit matrix can express 256 gray levels (accurately 16×16+1=257 gray levels, but the number of gray levels is 256 at the maximum because input multi-valued image data is 8-bit data for each pixel). Similar to the first embodiment, the unit matrix undergoes clustered-dot digital-halftoning of fatting dots from the center of the matrix as the density increases.
FIG. 6 is a schematic view showing the relationship between the nozzle array of a printhead according to the second embodiment of the present invention, a driving signal for each nozzle, and a dot which is discharged from each nozzle and attached onto a printing medium.
As is apparent from c of FIG. 6 showing the adhered position of an ink droplet, dot clusters which form unit matrices have the same shape regardless of the position even in time-divisional driving. In the second embodiment, the section size is “8”, and the unit matrix size in the nozzle array direction is “16” which is twice larger than the section size. The least common multiple is 16, and the period of 16 pixels, i.e., the value of the period coincides with the unit matrix size. For this reason, no patterns of different shapes each in a predetermined period shorter than the period of the unit matrix in the nozzle array direction are repetitively formed.
Since dot clusters of the same shape are regularly formed at pixel positions, degradation of the image quality under the influence of dots adhered on a paper surface particularly in high-speed printing is suppressed in comparison with a conventional case wherein patterns of different shapes are repetitively formed.
As described above, according to the second embodiment, dot clusters of the same shape can be formed in unit matrices. Periodical density unevenness can be prevented, an adverse effect between dots attached on a printing medium can be reduced, and high image quality can be implemented.
In the first and second embodiments, the section size is “8”, and the unit matrix sizes in the nozzle array direction are “8” and “16”, respectively. However, the present invention is not limited to this. For example, the present invention can be applied when the unit matrix size in the nozzle array direction is an integer multiple of the section size “8”, i.e., “32, “64”, . . . .
In practice, considering a case wherein an image is printed by performing digital-halftoning for image data enough to express one pixel by 8 bits, the value (n) of the ratio of the unit matrix size in the nozzle array direction of the printhead to the section size suffices to be about n=2. The image quality is traded off for graininess of a printed image, and the value n may be set to n=3 or more when the printing resolution further increases in the future or demands arise for an expression at higher gray levels in the future.
Third Embodiment
The first and second embodiments have described 1-pass printing. The third embodiment will describe an example of forming dot clusters of the same shape at image positions on the basis of the same idea even for multi-pass printing. For descriptive convenience, the third embodiment will exemplify 2-pass printing, but the present invention can also be applied to 4-pass printing and 8-pass printing.
FIG. 7 is a schematic view showing the relationship between each scanning and the image position in 2-pass printing.
In FIG. 7 , dots printed by the first pass are dots with small points, and dots printed by the second pass are hatched dots.
In 2-pass printing, printing is done using the latter half of the nozzle array of the printhead for the first pass. For descriptive convenience, the number of nozzles of the printhead shown in FIG. 7 is “16”, and the section size in time division is “8”. Also in 2-pass printing, similar to the first and second embodiments, printing rasters are printed by the same block, and dot clusters of the same shape can be formed in unit matrices.
In this case, however, the conditions that the number of nozzles of the printhead is exactly divisible by the printing pass count and the quotient is a multiple of the section size must be satisfied, like the above example.
FIG. 8 is a view showing a checkered mask pattern as an example of a mask pattern used for 2-pass printing.
The type of mask pattern is not particularly limited, and is an arbitrary pattern such as a mask pattern having a random distribution or a gradation pattern whose average distribution changes depending on the position. With this pass mask, image data is allotted to each scanning.
According to the third embodiment described above, similar to the first and second embodiments, periodical density unevenness can be prevented even in 2-pass printing, an adverse effect between dots attached on a printing medium can be reduced, and high-quality printing can be implemented.
The third embodiment has described 2-pass printing, but the same effects can be achieved when the same configuration as that in the third embodiment is adopted for 4-pass printing, 8-pass printing, 16-pass printing, and the like.
The above-described embodiments have exemplified a clustered-dot unit matrix and execute digital-halftoning. However, the present invention is not limited to this, and may use, e.g., a dispersed-dot unit matrix.
In the time-divisional driving method described in the above embodiments, nozzles are sequentially driven in the ascending order of the nozzle number in each section. However, the present invention is not limited to this.
Of inkjet printing methods, the above embodiments adopt a method which uses a means (e.g., an electrothermal transducer or laser beam) for generating thermal energy as energy utilized to discharge ink and changes the ink state by thermal energy. This inkjet printing method can increase the printing density and resolution.
The above embodiments have exemplified a serial scan type inkjet printing apparatus, but the present invention is not limited to this. For example, the present invention can also be effectively applied to an inkjet printing apparatus using a full-line printhead having a length corresponding to the maximum width of a printable printing medium. The printhead of this type can take a structure which satisfies the length by a combination of printheads, or an integrated printhead structure.
In addition, the present invention is also effective when the serial scan type inkjet printing apparatus as described in the above embodiments uses a printhead which is fixed to the apparatus body, or an interchangeable cartridge type printhead which can be electrically connected to the apparatus body and receive ink from the apparatus body when attached to the apparatus body.
Furthermore, the inkjet printing apparatus according to the present invention may be used as an image output apparatus for an information processing device such as a computer. The inkjet printing apparatus may also be used for a copying machine combined with a reader or the like, or a facsimile apparatus having a transmission/reception function.
As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
CLAIM OF PRIORITY
This application claims priority from Japanese Patent Application No. 2004-355891 filed on Dec. 8, 2004, the entire contents of which are incorporated herein by reference. | A printing apparatus divides printing elements of a printhead into blocks, time-divisionally drives the printing elements, and prints a halftone image on a printing medium in accordance with a result obtained by performing digital-halftoning for input multi-valued image data in each matrix of a predetermined size. The apparatus includes a scanner for reciprocally scanning the printhead, a conveyor for conveying the printing medium in a direction different from a scanning direction of the printhead, and a controller for printing a halftone image in each matrix. An arrayed direction of the printing elements is the convey direction of the conveyor. The controller sets a size of the block to be equal to or an integral multiple of a size of the matrix in the convey direction. The digital-halftoning increases the number of dots from a center of the matrix as a density expressed by the multi-valued image data increases. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
The present application is related to the following commonly owned applications: Ser. No. 202,638 filed June 6, 1988 in the name of M. Thompson entitled "Flow Noise Suppression For Electronic Valves"; Ser. No. 119,009 filed Nov. 12, 1987 in the name of Robert Torrence entitled "Indicating Refrigerant Liquid Saturation Point"; Ser. No. 168,041 filed Mar. 14, 1988 in the name of Robert Torrence entitled "Controlling Superheat in a Refrigeration System", Ser. No. 007,147 filed Jan. 22, 1987 entitled "Controlling Refrigeration.
BACKGROUND OF THE INVENTION
The present invention relates to systems for controlling vapor lock in fuel lines of vehicles employing a Positive pressure circulating fuel supply to the engine. Fuel systems of this type are employed in automotive vehicles having fuel injected engines wherein a fuel pump is provided at the tank for circulating a continuous flow of fuel under positive pressure to the fuel injectors.
In service of vehicles employing injected engines with a positively pressurized flow of fuel continuously circulated to the injectors during engine operation, the fuel lines absorb heat from the engine compartment and problems have been encountered with vapor lock in the fuel line, particularly on the portion of the line returning fuel to the tank. The fuel returning to the tank in a Positively pressurized pumping system is discharged to the tank at substantially atmospheric pressure and therefore the fuel in the return portion of the line is subject to evaporation at a lower temperature than the fuel at a higher pressure when discharged from the pump.
In order to eliminate evaporation and vapor lock of the fuel in the return line, it has been proposed to provide an inter-cooler in the return portion of the fuel line to lower the temperature of the fuel below its vaporization point. One technique that has been suggested is that of providing a heat exchanger with the refrigerant employed for the vehicle air conditioning system. The vehicle air conditioning refrigerant is a convenient source of cooling medium in as much as the air conditioning system is usually operated in climatic conditions which would raise the engine compartment temperatures sufficient to cause vapor lock in the fuel line.
However, in attempting to provide heat exchange between the fuel line and the air conditioning system refrigerant, problems have been encountered because the air conditioning system controls are designed to control flow of refrigerant to provide a slight amount of superheat at the outlet of the air conditioning evaporator; and, therefore little cooling is available in the refrigerant for heat exchange with the fuel line. Accordingly, it has been desired to find a way or means of utilizing a heat exchanger in the air conditioning refrigerant line to cool the fuel line in order to prevent vapor lock in the low pressure side of the fuel line returning to the fuel tank.
SUMMARY OF THE INVENTION
The present invention provides a heat exchanger disposed in the low pressure or return side of a continuously circulating positively pressurized engine fuel supply, such as that employed with engines having fuel injectors, for preventing vapor lock in the low pressure side of the fuel line returning fuel to the tank.
The present invention employs an electrically operated refrigerant expansion valve for controlling flow of refrigerant to the evaporator and the fuel line heat exchanger, and employs a microprocessor based controller to provide a pulse-width-modulated duty cycle signal to the refrigerant expansion valve for controlling flow of refrigerant in the system. A pressure transducer is disposed in the refrigerant line to measure the pressure of the refrigerant flowing therein as discharged from the evaporator and provides a signal to the microprocessor. The microprocessor then determines the saturation temperature of the refrigerant from a look-up table.
A temperature sensing thermistor is disposed in a refrigerant line between the fuel line heat exchanger and the compressor intake and provides a signal to the microprocessor of the actual temperature of the refrigerant discharging from the fuel line heat exchanger. The microprocessor then compares the saturation temperature with the actual temperature to determine the amount of superheat at the outlet of the fuel line heat exchanger and provides the pulse with modulated signal to the refrigerant expansion valve from a predetermined algorithm based upon the superheat at the outlet of the fuel line heat exchanger.
An optional feature of the invention permits the compressor for the air conditioning system to be initially energized upon command from the microprocessor based upon measurements of the temperature of the fuel in the fuel line.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the control system of the present invention illustrating the refrigerant circuit and the electrical connection of the components;
FIG. 2 is a flow diagram of the electrical control signal generation for the system of FIG. 1.;
FIG. 3 is an electrical schematic for the microprocessor based controller of FIG. 1;
FIG. 4 is a pressure temperature plot for the refrigerant employed in the system of FIG. 1;
FIG. 5 is a portion of a schematic similar to FIG. 1, showing an alternate embodiment of the invention; and,
FIG. 6 is a flow diagram of the embodiment of FIG. 5.
DETAILED DESCRIPTION
Referring to FIG. 1, the system of the present invention is indicated generally at 10 as having a portion 12 of the low pressure side of an engine fuel line circulating through a heat exchanger block 14 which has a portion of the refrigerant line 16 of the vehicle air conditioning system passing through block 14 in heat exchange relationship with the fuel line 12. The refrigerant line 16 passes from the heat exchanger block 14 to the inlet of a compressor 18 which is adapted to be engine driven by a belt 20 passing over a pulley 22 which is clutched to the compressor by an electrically actuated clutch 24. The outlet of the compressor 18 is discharged through conduit 26 to an exothermic heat exchanger or condenser 28 which discharges along conduit 30 to the inlet of an electrically operated expansion valve indicated generally at 32 which discharges low pressure refrigerant through conduit 34 to the inlet of an endothermic heat exchanger or evaporator 36 disposed in the vehicle compartment to be cooled. The evaporator 36 discharges refrigerant through conduit 38 through a passage 40 provided in the block 42 of valve 32 which passage 40 communicates with conduit 16 for returning refrigerant to the fuel line heat exchanger and the compressor.
A pressure transducer 44 has its inlet port communicating with the passage 40 for sensing the pressure of the refrigerant discharged from the evaporator 36.
Electrical power for the system is provided by the vehicle supply indicated generally at B through junction 46 and junction 47 to a voltage regulator 48 which provides power to the microprocessor based controller 50. The controller 50 receives inputs from comparator 52 and the pressure transducer signal along line 54.
The comparator 52 receives a signal along line 56 from one lead of a thermistor indicated b T A with the remaining lead 58 from the thermistor connected to junction 60 which receives a positive supply voltage +V along line 62 from the voltage regulator.
The controller 50 provides an output signal along line 64 to one lead of a solenoid coil 66 attached to the valve block 42 for providing electromagnetic energization of the refrigerant valve. The remaining side of the coil receives power along line 68 to power junction 47.
A compressor clutch signal is provided from the controller 50 along line 74 to the compressor clutch which receives power along line 76 through junction 78 and power lead 80 connected to power junction 47.
If desired, a condenser cooling fan motor 82 may be provided receiving power along lead 84 from relay 86 powered from junction 78 through lead 88 with the signal input to the relay 86 provided along lead 90 from the controller 50. The details of the manner of controlling the condenser fan 82 are described in the co-pending application of Robert J. Torrence entitled "Indicating Refrigerant Liquid Saturation Point" and commonly assigned to the assignee of the present application and will be omitted here for the sake of simplicity.
In the typical automotive air conditioning system, an evaporator blower motor 92 is provided for discharging air over the evaporator to the passenger compartment; and, the motor 92 may be powered by an operator select switch 94 connected to the motor by lead 96 and receiving power along lead 98 from junction 46.
Referring to FIG. 2 in the first embodiment of the invention, upon energization of the compressor clutch by the operator select step 100, and set FLAG equals zero, at 102, the compressor clutch is engaged at step 104 and after a suitable time delay of approximately 1 second at step 103, an initial 40% duty cycle pulse-width-modulated signal is provided at step 104 to the solenoid coil 66 of the expansion valve 32. Upon system power up, the pressure signal from the pressure transducer 44 is applied to the controller 50 at step 105.
The microprocessor of controller 50 is operative at step 106 to enter a look-up table in memory to determine the saturation temperature TS corresponding to the measured temperature from manufacturers information for the particular refrigerant employed. Preferably, refrigerant available commercially under the designation Freon 12, is employed and the pressure-temperature plot therefor is illustrated in FIG. 4.
The signal from thermistor T A is inputted to the controller 50 at step 107 and the temperature T A is determined from a look-up table at step 108. The super heat is then determined at step 109 by subtracting a derived saturation temperature T S from the actual measured temperature T A at step 109.
At step 110, ΔE old is equated to ΔE new ; and, at step 111 ΔE new is equated to subtracting 7° from the superheat determined in step 109, where ΔE is the error between the actual superheat and the desired superheat of 7° F.
At step 112 the change ΔΔE is equated to ΔE old subtracted from ΔE new ; and, in step 113 FLAG is set equal to 1. In step 114, the pulse-width PW is determined by adding to the previous pulse width the quantity ΔE new /4 and ΔΔE/2, thus providing an updated value for the pulse-width-modulated control signal to the solenoid 66.
The thermistor T A in the presently preferred Practice is a 30K ohm NTC thermistor available from Fenwall Electronics, 63 Fountain St., Framingham, Mass. 01701 bearing manufacturer's identification UUR43J24 and has a resistance of 30K ohms at 25° C.
Referring to FIGS. 1 and 3, upon closure of the operator select switch 101, the microprocessor U4 which in the presently preferred practice comprises a solid state device bearing Motorola designation 68705P3, available from Motorola Semiconductor Products, 2060 Algonquin Road, Schaumburg, Ill. 60195, receives power at pin 3 thereof from the voltage regulator 48. The regulator Preferably comprises a solid state device Ul bearing Motorola designation MC7805 which receives at pin 1 thereof a voltage V B from the vehicle battery, typically 9 to 16 volts, through diode CR1 and resistor R1. The voltage regulator 48 provides through capacitor CZ a positive 5 volts at pin 3 of the processor U4.
Referring to FIG. 3, device CY1 is an oscillator in series to ground with capacitor C13 and in parallel with capacitor C12. CY1 is connected to pins 5 and 4 of microprocessor U4 for providing timing pulses preferably on the order of 4 mhz.
Controller 50 includes a "dead man" timer which monitors the microprocessor function. U4 provides an output on pin 14 thereof through capacitor C7 to junction 119 which is connected to the base of Q1 and to ground through resistor R7. Q1 has the emitter grounded and the collector junction connected to junction 120 which is connected to pin 6 of device U5 which comprises a LM555D timer available from National Semiconductor Corp. 2900 Semiconductor Dr., Santa Clara, Calif. 95051. U5 also has pin 6 connected to junction 120, pin 5 grounded through capacitor C9 and Pin 1 grounded Pin 7 of U5 is connected to junction 122 which is biased through resistor R3 with a positive voltage from the regulator 48. The voltage of junction 122 is also applied through resistor R6 to the collector junction of Q1. Pin 4 of U5 is connected to junction 124 which is grounded through capacitor C10 and junction 124 also is biased by a positive voltage through resistor R4. The output at pin 3 of U5 is connected through capacitor C11 to junction 126, which is biased through resistor R5 by a positive 5 volts from the regulator 48, and is protected by diode CR5 and is connected to input 28 of the microprocessor U4.
The device U5 is operative such that if a signal is not received from pin 14 to Q1, after 70 milliseconds, U5 is not reset by Q1 and provides a reset signal through pin 28 to the microprocessor U4.
When the microprocessor is operative to provide an output signal at pin 18, the signal is applied through resistor R11 to the base of Q3 which has its emitter grounded. The collector junction of Q3 is biased to a positive voltage from the battery through resistor R10 and is connected through junction 128 to the base or pin 1 of power FET device Q10. The output at pin 2 of Q10 is compressor clutch; and, the output at pin 3 of Q10 is grounded. When a signal is received from pin 18 of U4 to the base of Q3, Q3 conducts thereby dropping the voltage on junction 128 and turning power FET Q10 off thereby de-energizing the compressor clutch.
Similarly an output from pin 16 of U4 is applied through resistor R9 to the base of device Q2 which has its emitter grounded and its collector junction biased to a positive voltage from the battery through resistor R8 and connected to junction 130. Junction 130 is connected to input pin 1 or base of power FET Q9 which has its output pin 3 grounded and output pin 2 connected to the coil 66 of refrigerant valve 32. The outputs are protected by Zener diodes CR7, CR4 and diode CR16. When a signal is received from U4 pin 16 to the base of Q2, Q2 conducts, thereby dropping the voltage to junction 130 and turning Q9 OFF thereby disabling the valve coil for turning the valve off.
Thermistor T A receives a positive battery voltage through a diode with the remaining lead connected to a junction 130 which is connected through capacitor C5 to ground and also to input pin of device U2. In the presently preferred practice, U2 comprises a said National Semiconductor LM556 timer which receives a positive 5 volts from the regulator 48 at pin 4, with pin 7 grounded and pin 3 grounded through capacitor C15. A signal from the microprocessor pin 10 is applied to pin 6 of U2 and triggers U2 to discharge capacitor C5. When the voltage on pins 1 and 2 of U2 from junction 130 reaches two-thirds of the biased voltage, U2 applies a signal through its output pin 5 and diode CR12 to junction 132 which is connected to input pin 2 of U4 and also grounded through resistor R2.
The microprocessor U4 measures the time to receive the signal, the time measurement giving a digital representation of the voltage on T A . The microprocessor can then look up the temperature of T A from a table of voltages and resistances provided by the manufacturer of the thermistor T A . The table for values of temperature versus resistance for the thermistor T A is set forth below as Table I.
TABLE I______________________________________ Alpha R-T Temp. Resis.°F. °C. Curve Coeff. Dev.______________________________________-76 -60 49.10 6.0 9.7-58 -50 27.54 5.6 8.2-40 -40 16.08 5.2 6.8-22 -36 97.03 4.9 5.5-4 -20 6.053 4.5 4.414 -10 3.890 4.3 3.332 0 2.568 4.0 2.350 10 1.731 3.8 1.368 20 1.194 3.6 0.377 25 1.00 3.5 0.086 30 .8413 3.4 0.6104 40 .8040 3.2 1.4122 50 .4412 3.1 2.4140 60 .3275 2.9 3.1158 70 .2468 2.8 3.7176 80 .1856 2.7 4.4194 90 .1460 2.6 5.1212 100 .1140 2.5 5.7______________________________________ R-T: multiply resistance at 25° C. by listed valve to obtain resistance at temperature. Alpha temperature coeff: denotes percent in resistance change per °C. at a specific temperature. Resistance Deviation: add to resistance tolerance at reference temperatur (25° C.) to give complete percentage of resistance deviation.
The pressure transducer signal is received along line 54 to the positive input at pin 3 of a comparator device U3 which in the presently preferred practice comprises a Motorola 2N2903D dvice. Comparator U3 receives a positive voltage at pin 8 thereof through junction 118 which is grounded throgh capacitor C19. The output of comparator 1 is applied to junction 140 which is grounded through resistor R27 and also applied through diode CR10 to input pin 2 of U4 through junction 132.
Pin 8 of the microprocessor is connected through resistor R28 to the base of Q12 which has its emitter grounded and its collector connected to the negative Input the end of U3. Pin 4 of U3 is grounded. The collector of Q12 is also applied to junction 142 which receives power from a positive voltage source from regulator 48 through resistor 25. Junction 142 is also grounded through capacitor C20. A signal is received from pin 8 of the microprocessor, Q12 conducts and discharges capacitor C20 to the negative pin of U3 thereby causing U3 to conduct a signal to pin 2 of the microprocessor U4. As explained above with respect to thermistor T A , the microprocessor is operative to measure the time that the signal is received and to provide a pulse signal output proportional to the time.
The values of resistances, capacitances, diodes and other devices are listed in Table II as forth below.
TABLE II______________________________________Resistance Capacitances Diodes andOHM Microfarads Other______________________________________R1-56 C1 10, 35 V CR1 GL41DR2-10K C2 .1, 50 V CR2 MMBD914R3-100K CR3R4-30K CR-1 CR4 IN5349 12 V, 5 WR5-10K C5-.1 CR5 MMBD 914R6-1K CR6 MLL 4145, 19 V, 1 WR7-1K C7-.01 CR7 IN5349, 12 V, 5 WR8-1K1 C8-.1 CR8 IN5352, 24 V, 5 WR9-2.2K C9-.01R10-1K C10-2.2 U1 MCT805R11-2.2K C11-2.2 U2 LM556D C12-18 pico U3 2N2903D C13-18 pico U4 M6805P2R14-10K U5 LM555DR15-2.2K C15-.01 Q1 2N3904 Q2 2N3904 C17-.01 Q3 2N3904 C18-.01 C19-.01 Q5 2H3304R21-7.3K C20-.1R22-10K Q9 BFS130 Q10 BFS130R25-200KR27-1KR28-2.2K CR13 MMBD914 CR14 MMBD283B CR15 MLL4346, 18V, lW CR16 GL41D______________________________________
Referring to FIG. 5, an alternate embodiment of the invention is illustrated generally at 200 as having the fuel line heat exchanger 214 with refrigerant line 216 and fuel line 212 flowing therethrough with a thermistor T A 'disposed in the discharge portion of the refrigerant line 216 as it returns to the compressor 218. The compressor discharge line 226 connects to the condenser which has been omitted for simplicity in FIG. 5. The inlet portion of refrigerant line 216 is connected to the block of the refrigerant expansion valve in a manner similar to that illustrated in FIG. 1, and which has been omitted in FIG. 5 for the sake of brevity.
A second thermistor T F is disposed in the inlet portion of fuel line 212 of the embodiment 200 for sensing the temperature of the fuel entering the heat exchanger 214.
In the presently preferred practice, the thermistor T A ' is identical to that of the embodiment of FIG. 1; and, the thermistor T F comprises a 30K ohm NTC thermistor bearing Fenwall identification UUR43J24. The thermistor T F has one lead thereof connected to a comparator 252 which provides inputs to a microprocessor based controller 250 receiving a regulated voltage supply from regulator 248 which is connected via line switch 201 to a positive source of voltage, for example, the vehicle 12 volt battery indicated generally at B. Voltage regulator 248 provides a positive regulated voltage along line 262 to junction 260 which is connected via lead 259 to the remaining lead of fuel line thermistor T F . Junction 260 also provides a positive voltage along line 258 to one lead of the thermistor T A ' which has its remaining lead 256 also connected to comparator 252. It will be understood that the comparator 252, controller 250 and voltage regulator 248 are similar to the corresponding components employed for the embodiment of FIG. 1.
Referring now to FIG. 6, upon closure of the engine ignition switch and energization of the voltage regulator 248, an indicator set FLAG--ΔE=0 is created at step 270 and a second indicator set FLAG--T F =0 is created at step 272; and, a test is performed at 274 to determine whether the operator select control has been moved to a position to indicate a desire to operate the vehicle air conditioning system. If this is the case, a test is performed at 276 to determine whether the compressor clutch is already energized; and, if not, a Pressure reading is taken at step 278 from the pressure transducer 44. It will be understood transducer 44 is employed in the same manner in the embodiment 200 of FIG. 5 as is the case for the embodiment 10 of FIG. 1, the pressure transducer having been omitted in FIG. 6 for brevity.
If the pressure reading from step 278 is less than 18 psig, at step 280 the microprocessor returns to step 274. If the pressure read from step 278 is at least 18 Psig, at step 280, then the compressor clutch is energized at step 282; and, after a one-second time delay at step 284, an initial 40% duty cycle pulse-width signal is applied to the valve coil 66 at step 286. It will again be understood that the same valve 32 is employed in the embodiment 200 of FIG. 6 as is employed in the embodiment of FIG. 1. The valve having been omitted from FIG. 6 for simplicity.
After initial energization of the expansion valve 32, a second reading of the pressure transducer 44 is taken at step 288 and is tested at step 290 to determine whether the pressure is less than or at least 18 psig. If the pressure is less than 18 psig, the compressor clutch is disengaged as indicated at step 292. If the pressure reading from the transducer 44 is at least 18 psig at step 290, then the saturation temperature T S is obtained from a look-up table as indicated at step 294. The look-up table is obtained by tabulating the coordinates of plotted points on the graph of FIG. 4. Once the saturation temperature T S has been obtained, a signal input from thermistor T A ' is obtained at step 296 and the value of temperature T A is determined from a look-up table at step 298 where the look-up table is taken from Table I hereinabove. The superheat S H is then obtained at step 300 by subtracting the temperature value T S from the temperature value T A . The error term ΔE new defined at step 302 and equated to ΔE old . ΔE new is then equated to the value obtained by substracting 7° F. from the value of the superheat determined in step 300 as illustrated in step 304. The terms ΔΔE is defined in step 306 as the difference obtained by substracting ΔE old from ΔE new , as determined in step 304 and as illustrated in step 306.
A test is performed at step 308 to determined whether the index FLAG--ΔE is equal to zero; and, if this is the case, the index FLAG--ΔE is set equal to one at step 310 and the microprocessor returns to step 288. If the index FLAG--ΔE is not equal to zero at step 308, then the pulse-width (PW) of the valve coil drive signal is determined at step 312 by the expression:
(PW)=ΔE.sub.new /4+ΔΔE/2+(PW)
The pulse-width as determined in step 312 is then applied to the coil 66 of the value 32 and the microprocessor recycles to step 274.
Returning to step 276, if the compressor clutch is already energized, the microprocessor proceeds directly to step 288. Returning to step 274 if the Operator Select control is set for the air conditioning system to be OFF, then the microprocessor proceeds directly to step 314 where a test is performed to determine whether the output of thermistor T F indicates fuel line temperature greater than 150°. If this is the case, index FLAG--T F =1 is set at step 316 and the logic proceeds to step 276.
If however, the fuel line temperature as measured at step 314 is not greater than 150° F., the test is Performed at step 318 to determine whether the index FLAG T F =1 and if this is not the case, the logic proceeds directly to step 274. If however, the index FLAG--T F is equal to one at step 318, then a test is Performed at step 320 to determine if the fuel line temperature T F is less than 120° F. If the test at step 320 determines that the fuel line temperature T F is not less than 120°, the microprocessor proceeds directly to step 276. If however, the test at step 320 indicates that the fuel line temperature is less than 120°F., then the index FLAG --T F is set equal to zero and the compressor clutch is disengaged at step 292.
The present invention thus provides for cooling engine fuel in a Positively pressurized fuel line by providing a heat exchanger on the low pressure side of the fuel line returning to the tank for heat exchange with the air conditioning system refrigerant. The fuel line heat exchanger is disposed between the passenger compartment air conditioning evaporator and the compressor inlet; and, the system employs an electrically controlled expansion valve for controlling flow of refrigerant in a system.
In one embodiment of the invention, refrigerant is circulated through the fuel line heat exchanger only when the vehicle air conditioning system is operated, on the assumption that fuel cooling is needed only under high ambient temperatures. In another embodiment of the invention the system is operative to sense the temperature in the fuel line at all times and to engage the air conditioning compressor clutch when the fuel line temperature exceeds a desired value, irrespective of whether the vehicle air conditioning system has been energized by the vehicle operator. The present invention employs a unique and novel system for providing an electrical control signal for a microprocessor based controller to control the width of a pulse-width modulated signal to an electrically operated refrigerant flow control valve to provide adequate control of the flow of refrigerant through the air conditioning evaporator and the fuel line heat exchanger.
It will be understood that although the invention has been hereinabove been described with respect to the illustrated embodiments, modifications and variations may be made in the invention, which is limited only by the following claims. | A system for preventing vapor-lock in a positively pressurized loop-type engine fuel line having the low pressure or tank return portion of the fuel line passing through a heat exchanger disposed in the refrigerant line for the vehicle air conditioner between the endothermic heat exchanger or evaporator and the compressor inlet. A thermistor senses the temperature of the refrigerant discharging from the fuel line heat exchanger and a pressure transducer senses evaporator discharge saturation pressure. Look-up tables are used to determine saturation temperature from the saturation pressure, and saturation temperature and actual refrigerant temperature compared to generate a pulse-width modulated control signal for controlling an electrically operated refrigerant expansion valve to maintain a desired amount of superheat at the discharge of the fuel line heat exchanger. | 5 |
This application is a continuation of Ser. No. 08/666,161 filed Jun. 19, 1996 now U.S. Pat. No. 5,736,863.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to monitoring and diagnostics of line processes used for the manufacture of semiconductor devices and more particularly to the measurement of critical dimensions of patterns by scanning electron microscopy.
(2) Description of Prior Art
Integrated circuits are manufactured by first forming discrete semiconductor devices within the surface of silicon wafers. A multi-level metallurgical interconnection network is then formed over the devices contacting their active elements and wiring them together to create the desired circuits. The wiring layers are formed by first depositing an insulating layer over the discrete devices, patterning and etching contact openings into this layer, and then depositing conductive material into these openings. A conductive layer is then applied over the insulating layer which is then patterned and etched to form wiring interconnections between the device contacts thereby creating a first level of basic circuitry. These circuits are then further interconnected by utilizing a second wiring level laid out upon a second insulating layer with via openings to the first level.
Depending upon the complexity of the overall integrated circuit, two to four levels of metallurgy are typically required to form the necessary interconnections and to direct the wiring to pads which make the external connections for the completed chip. Patterning of the contact and wiring levels is accomplished by photolithographic masking techniques accompanied by reactive-ion-etching(RIE).
A high density of circuit elements designed to sub-micron dimensions requires extremely tight dimensional control. Slight variations in processing conditions can generate significant dimensional deviations of the patterned features. To this end highly sensitive inspection methods are required to assure the dimensional and structural integrity of the design patterns.
The scanning electron microscope(SEM) has become a most valuable tool for examining and measuring patterns of sub-micron dimensions. Optical microscopy, even with the finest available microscopes, cannot resolve these images with sufficient accuracy to permit reliable measurements. Many times the objects can be discerned, but measurements to the accuracies required are not possible. The SEM permits such precise measurements to a remarkable degree and, as such, has become a vital tool for monitoring all facets of integrated circuit device manufacturing. In addition, other processing defects, such as small pockets of debris in via or contact openings, could go undetected by optical microscopy. In the SEM, however, they are revealed with extraordinary crispness and clarity.
The principle of the SEM requires placement of the specimen into a vacuum chamber where a focused electron beam impinges on the area being observed. The surface region of the specimen where the inspection is made must be electrically grounded within the SEM. Otherwise electrons from the beam accumulate on the surface and cause severe distortions of the image. Earlier SEMs with smaller chambers could only accept small specimens which were usually mounted onto aluminum pedestals using a conductive silver paste providing a good ground contact. Nevertheless, when the specimens have exposed layers of insulating films such as silicon dioxide or photoresist, local charging of these surfaces occurs, particularly when high beam accelerating voltages are required to obtain sufficient resolution. The result is image distortion sometimes even to the point of obliteration. The problem is avoided on disposable specimens by sputtering a thin layer of gold onto the specimen just prior to insertion into the microscope. This provides a conductive discharge path for the electrons. Herrick et.al U.S. Pat. No. 5,460,034 when examining epitaxial layers of AlGaAs/GaAs, found that a layer of gold 100 Angstroms thick improved their resolution from about 100 Angstroms to 60 Angstroms, by reducing charge build-up.
Current technology permits larger specimens to be placed into the SEM. Whole wafers taken from a production job may now be examined with the SEM and then re-inserted into the production line for continued processing. The SEM is used to examine photoresist images to determine if the feature dimensions are within specifications or if any residue or debris has remained in the developed pattern. The etched patterns in the structural layers are likewise inspected. The ability to insert whole wafers into the SEM for routine examination and measurement with minimal wafer handling risk makes this instrument ideal for production line inspections. However, depositing gold or some other conductive material to alleviate the charging problem is no longer an acceptable option. Since a conductive coating cannot be applied, other means must be taken to provide suitable discharge paths for the electron beam where such a problem exists.
The established features which need dimensional inspection include contact openings, via openings, polysilicon line widths, and metal line widths. Not only must these features be capable of measurement to high resolution but their edges must also verified to be of proper contour. To this end an SEM inspection is useful in establishing the thoroughness of certain processing steps viz. whether an etching operation has fully performed its objective, whether it has left remnants of un-etched material, or whether it has exceeded its objective by invading subjacent material. The accomplishment of these objectives is frequently impaired by electron charging when the feature area cannot provide an adequate discharge path.
It is frequently impossible to accurately inspect and measure pattern features in integrated circuit product dice with the SEM, especially at high resolution, because of the presence of p-n junctions and insulating layers. These barriers obstruct adequate conductive paths for the electrons to the substrate ground and result in image distortions due to charging. In addition, charge build-up in certain device areas such as field-effect-transistor gates, can cause damage to thin underlying gate oxides.
The effects of electron charging on the inspection and measurement of patterns with an SEM are illustrated by FIGS.1 and 2. In FIG. 1 there is shown a cross section of a wafer 50 having a layer of silicon oxide 52 and a layer of polysilicon 54. A layer of photoresist has been patterned over the polysilicon layer 54 to form a stripe 56 of width -d-. Such configurations are commonly encountered in the manufacture of integrated circuits. Not only is the SEM called upon to measure the line-width -d- to an accuracy of the order of tenths of a micron, but the integrity of the edge profile must also be established. FIG. 2A shows an SEM image of the photoresist line 56 in the absence of image charging, as would be observed when proper discharge paths are provided. The shading lines represent the darkness of the image. The edges of the photoresist stripe 56 are clearly discernible and the dotted lines 57 are the measurement reticles brought into alignment with the bottom edges of the stripe 56. The spacing -d- between these lines is well defined. Superimposed over the image is a secondary electron intensity scan 58, also provided by the SEM. This signal shows sharp peaks 58A which characterize the edges of the photoresist stripe 56.
In FIG. 2B there is shown the same feature as in FIG. 1 except that now severe image charging has occurred within the SEM. The reticle lines 57 are placed over this image to show the approximate locations of the edges of stripe 56 corresponding to the width -d- . The darker portions of the image now protrude inward, past these lines and only gradually lighten towards the center of the stripe 56. The edge defining peaks 58A of the secondary electron scan 58 are entirely absent. Images of the type shown in FIG. 2B are useless for pattern inspection and measurement purposes.
This invention teaches the use of independent and specially designed test structures having patterns corresponding to features of the integrated circuit dice and provided with conductive paths to drain away the electrons from the SEM electron beam.
Independent test structures for the observation of open circuits and short circuits caused by defects using an SEM have been describes by Mahant-Shetti et. al. U.S. Pat. No. 5,159,752. The patterns used by these authors to observe shorts consist of multiple small metal islands enclosed within the squares of a large metal grid structure and separated from the grid by dimensions comparable to those found in integrated circuit metal patterns. An island shorted to the grid by a defect produces a different intensity of secondary electrons and consequently a different shade in the SEM view. The structure for opens utilizes the same pattern but with a connecting stripe between the island and the grid metal. An open stripe caused by a defect results in a different shading of the island compared to the others.
An additional advantage of using independent test structures for SEM inspections rather than subjecting product structures to the SEM beam is that charge sensitive structures such as field-effect-transistor gates are not subjected to the risk of gate oxide damage. Lur et.al. U.S. Pat. No. 5,384,268 have dealt with such charging as it occurs during high energy ion implantation. Here a thin conductive layer of titanium is applied over the structures prior to the implant and removed by dry etching or wet chemical etching afterwards. Clearly, this would not be a practical solution for the frequent SEM inspections required during the interconnection level processing.
SUMMARY OF THE INVENTION
It is an object of this invention to describe specially designed test structures containing pattern features to be inspected by an SEM. The test structures are provided with ground paths or other means by which image distortion from electron charging within the SEM is avoided or significantly reduced. Semiconductor junctions and insulation layers which impede the discharge in the product circuitry are avoided in the design of the test structures. The layout of each test structure is dependent upon the location of the pattern which it represents within the interconnection level hierarchy of the integrated circuit. In two embodiments, direct ground paths to the silicon wafer substrate are provided. In another embodiment additional area is connected to the feature in order to spread the accumulated charge over a larger area. The test structures are applicable only to features which contain conductive elements. The test structures may be formed within the wafer kerf regions or within dedicated manufacturing test sites.
It is a further object of this invention to describe the design of test structures to be used for SEM inspection of the integrity of contact openings by determining if they have been properly opened by a contact etch process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross section of a photoresist stripe on a polysilicon layer.
FIG. 2A is a representation of an SEM photograph of the photoresist stripe of FIG. 1 in the absence of surface charging.
FIG. 2B is a representation of an SEM photograph of the photoresist stripe of FIG. 1 in the presence of severe surface charging.
FIG. 3 is a top view of a silicon wafer showing an example layout of integrated circuit dice with kerf areas available for test structures.
FIG. 4A,B and FIG. 5A,B are cross sections of test structures designed for SEM observation.
FIG. 5C is a top view of a structure depicting the second embodiment of this invention.
FIG. 6 is a view of a structure depicting the third embodiment of this invention.
FIG. 7 is a cross section of the fourth embodiment of this invention.
FIGS. 8A and 8B are representations of SEM views of the fourth embodiment of this invention.
FIG. 9 is a cross section of the fifth embodiment of this invention.
FIGS. 10A and 10B are representations of SEM views of the fifth embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Accordingly, in the embodiments of this invention, a p-type <100> oriented silicon substrate(wafer) is provided. The embodiments use, as an example, an integrated circuit process for the manufacture of CMOS devices. It is to be understood that the application of this invention is not confined to CMOS integrated circuits but could be applied to any semiconductor fabrication process.
Referring to FIG. 3, semiconductor devices are formed within the surface of a silicon wafer 10 in a pattern consisting of an array of rectangular integrated circuit dice 62. Test structures of various kinds are simultaneously formed in the narrow regions 60 between the dice 62 which comprise the kerf area. This is the region that will be consumed by a saw cut which separates the dice at the completion of processing. Among these test structures are those designed for inspection of dimensional and structural integrity with an SEM. In the first and second embodiments there will be discussed, those structures which have direct conductive paths to the silicon substrate ground for the purpose of draining away charge from the electron beam.
The conductive path for the first embodiment passes through a conventional metal contact while in the second embodiment, a polysilicon buried contact is employed. A third embodiment incorporates the use of pseudo-grounded discharge paths formed by means of large area conductive attachments to the conductive regions to be inspected. These attachments provide a means to spread out the charge while the inspection takes place and thereby lowering the charge in the region of interest. The fourth and fifth embodiments address the inspection of contact openings.
After the wafer has undergone all processing steps preceding and including the growth of gate oxide, the processing of the inspection test sites within the kerf area is begun. Thus field oxide isolation regions and other ion implants or diffusions as, for example, n-wells or p-wells are in place. The photomask set must have been designed to mask the growth of isolation oxide and any implants or diffusions within the kerf area allotted for the test structures except for an implant which reinforces the conductivity type of the substrate material.
The first embodiment, shown in cross section in FIG. 4A, is a contact opening which, in the integrated circuit, would be insulated from substrate ground by a p-n junction. Designed as a special structure for SEM inspection without a subjacent p-n junction, the base of the contact opening 14 in the interlevel-dielectric(ILD) layer 12 forms an unhampered conductive path to the SEM ground 8 via the substrate 10. A boron implant 11 in the test structure reinforces the surface conductivity of the silicon at the contact assuring the absence of carrier depletion at the silicon interface. The surface of the ILD layer 12 can accumulate some surface charge, especially if the SEM is operated at high potentials to achieve high resolution or if the inspection time is too long. With judicious procedure, this charging can be moderated sufficiently to allow ample contour inspection. The elimination of charging in the base of the contact 14 by eliminating the p-n junction reveals pits and debris which would otherwise be obscured.
After SEM inspection, the test structure shown in FIG. 4A is processed further and used as the inspection structure for the next level opening which in this embodiment is a via opening shown in FIG. 4B. The contact opening is filled with conductive material 16 such as is used for tungsten plug metallurgy and a patterned layer of first metal 18 is formed over the ILD layer. SEM inspection and measurement of the metal pattern features are then performed. Again, the discharge path provided by the test structure permits inspection and measurement without image distortion due to charging. The pattern dimensions incorporated into the metal 18 in the test structure are representative of those found in the accompanying integrated circuit.
The via opening 22 is etched into the insulating layer 20 at which point SEM inspection is again performed to verify dimensional and structural compliance of the via opening. The electron discharge path of the contact opening 14 is now extended to the via opening 22 through the contact 16 and first metal layer 18. Further extension of this grounding concept to via openings and metal patterns in higher levels of metallization should now be apparent. An advantage of this scheme is that each successive level of inspection can focus on the same structures thereby minimizing the number of required inspection sites required.
A second embodiment of this invention is shown in FIGS. 5A and 5B. As in the first embodiment a p-type <100> oriented silicon substrate is provided. The embodiment uses as an example, an integrated circuit process for the manufacture of CMOS devices. Semiconductor devices are formed within the surface of the silicon wafer in a pattern consisting of and array of rectangular integrated circuit dice. Test structures are formed in the narrow regions 60 between the dice 62 which comprises the kerf area(FIG. 3).
Referring to FIG. 5A, there is shown a substrate 10 grounded to the SEM by a connection 8. The inspection test site contains no p-n junctions and the surface conductivity is reinforced by an implanted layer 11. A buried contact opening 36 is formed within the gate oxide layer 30. Typically, when buried contacts are used, the gate oxide over the device area is first covered by a thin layer of polysilicon 32 and the buried contact opening 36 is then formed by etching through both layer 32 and the gate oxide 30 as shown in the figure.
At this point the critical dimensions and the integrity of the buried contact opening 36 are validated by SEM inspection. Electrons from the beam are discharged during the inspection by the conductive path through the wafer 10 to the ground 8 permitting a crisp and undistorted image. A polysilicon layer 34 is next deposited and patterned over the buried contact. The polysilicon gates and buried contact conductors in the integrated circuit dice are subsequently patterned in this layer and the subjacent layer 32. The test structure pattern 34 contains polysilicon lines whose widths correspond to those found in the product dice.
FIG. 5C shows an example of the top view of the polysilicon pattern 34. The SEM inspections of this pattern permits measurements of line widths corresponding to gates t G and buried contact stripes t BC . Referring also to FIG. 5B, further processing of these test structures wherein an insulator 38 with a via opening 40 has been formed, now permits SEM inspection and measurement of this via opening 40 with the benefit of a conductive path to ground through the buried contact 36. This via might, for example, represent the contact of a load resistor formed in a second polysilicon layer to a gate electrode formed in a first polysilicon layer. Such a configuration can be found in poly-load SRAM cells. The top view of the test structure in FIG. 5C shows this via opening 40 as well as the location of the buried contact 36. As in the first embodiment the conductive path provided in the second embodiment may be propagated through higher levels of metallization for other SEM inspections.
A third embodiment of this invention consists of a metal test pattern lying over an insulated surface wherein the portion to be inspected for dimensional compliance is attached to a larger region of metal as shown in FIG. 6. The conductive structure 70 contains a portion 74 which has the dimensions of corresponding features in the product dice which is attached to a large area of conductor 72. The presence of the area 72 permits the spreading out of the SEM charge build-up over a large area, thereby minimizing image distortion by reducing the charge in the region of interest. The effectiveness of these structures depends upon the area of the conductive ballast 72.
A fourth embodiment of this invention is illustrated by FIG. 7 and 8. In FIG. 7 there is shown a cross section of a test structure having a plurality of contact openings designated by L, M, N, O, and P. The substrate 10 is p-type and is grounded to the SEM at the connection S. Alternate openings L, N, and P are formed over n+ regions in the substrate, while the openings M and O are formed over p+ regions. The contact openings are formed in the insulative layer 82 by reactive-ion-etching. If the contact openings are properly exposed by the RIE, charging occurs in openings L, N, and P because the p-n junction prevents electron flow to ground. The exposed silicon surfaces in openings M and 0, however, are grounded through the p+ region and therefore do not become charged. The appearance of this test structure with properly opened contacts is shown in FIG. 8A. The alternating shades along the row of contacts can be easily recognized and interpreted. Residual insulating layer within the contact openings will not allow proper electron discharge and the row of contacts appear with equal shades as shown in FIG. 8B. Partially open contacts display slight but easily discernable variations in tone.
Whereas the fourth embodiment is a test structure designed to examine contact openings for completeness of insulator etching, a fifth embodiment is next described which utilizes the same principle as the fourth embodiment to inspect contact openings having a metal silicide layer over the silicon at their base. Such contacts are encountered in integrated circuits utilizing the self-aligned silicide(Salicide) process. See for example Wolf, S., "Silicon Processing for the VLSI Era", Vol.2, Lattice Press, Sunset Beach, Calif., Vol.3 (1990), p144ff. The test structure is shown in cross section in FIG. 9. The silicide layer 84, frequently TiSi 2 , is formed over the silicon surface by depositing the metal and annealing to form the silicide. The insulative layer 82 has the contact openings designated by L, M, N. O. and P. The substrate 10 is p-type and is grounded to the SEM at the connection 8. Alternate openings L, N, and P are formed over n+ regions in the substrate, while the openings M and O are formed over p+ regions. The contact openings are formed in the insulative layer 82 by reactive-ion-etching.
When examined in the SEM, all the openings appear of equal shade if the etching step terminated within the silicide layer 84 as illustrated by FIG. 10A. This layer 84 is grounded through contact with the p+ regions and through the substrate contact 8. If the silicide layer has been penetrated by the etchant, differences in contrast are observed between the n+ and p+ contact openings as illustrated by FIG. 10B. Partially penetrated silicide layers display slight but easily discernable variations in tone.
By using a string of contacts with alternating n- and p- regions as illustrated for the fourth and fifth embodiments by FIGS. 7 and 9, even slight differences in SEM charging can easily be resolved.
While this invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.
While the embodiments of this invention utilize a p-type silicon substrate, an n-type silicon substrate could also be used without departing from the concepts therein provided.
It should be further understood that the substrate conductivity type as referred to herein does not necessarily refer to the conductivity of the starting wafer but could also be the conductivity of a diffused region within a wafer wherein the semiconductor devices are incorporated. | The inspection and measurement of critical dimensions of patterned features during the manufacture of sub-micron integrated circuits relies heavily upon the scanning-electron-microscope(SEM). This instrument is capable of quick, clean, and accurate measurements of features on large in-process silicon wafers. However, such features are frequently isolated from the electrical ground of the microscope by virtue of their circuit design. This creates a charge build up from the electron beam in the SEM and causes distorted and indistinct images, incapable of being measured. Also, such static charge build-up can be destructive to certain circuit elements. This invention teaches the use of independent inspection test structures, fabricated in wafer saw kerf regions or within designated test sites, especially designed to provide a reduction or elimination of charge build up during SEM observation. The structures are built to follow conventional processing and carry the desired features to be examined at each successive process level. They are particularly useful for examining and measuring contact and via openings, and measuring interconnection metal line widths and spacings, including polysilicon structures. | 6 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to line trimmers for trimming vegetation, such as weeds and grass, and, more particularly, to line trimmers having a guard mounted thereon.
[0002] In the prior art, it is known to mount guards onto line trimmers (as used herein, a “line trimmer” is a hand-held, motorized device having a drive shaft with a rotating cutting head, wherein at least one filament is mounted to the cutting head that is caused to flail upon rotation of the cutting head and used to trim vegetation, such as weeds and grass (e.g., the line trimmer sold under the brand “WEED WHACKER”)).
[0003] It is also known to provide a cutting edge on the guards of line trimmers. The cutting edge is disposed in, and generally obliquely to, a plane defined by the flailing of the filament, and acts to clip excessive filament length. In this manner, the cutting edge ensures that the length of the filament does not exceed the size of the guard and, upon rotation, does not extend therebeyond. Examples of such cutting edges are shown in U.S. Pat. No. 4,550,499 to Ruzicka, and U.S. Pat. No. 6,052,976 to Cellini et al.
[0004] In U.S. Pat. No. 5,491,962 to Sutliff et al., a line trimmer is disclosed having both flexible filaments and rigid cutting blades mounted to the rotating head. The rigid cutting blades and the flexible filaments are disposed generally parallel with the flexible filaments being located above the cutting blades; the flexible filaments and the rigid cutting blades are vertically aligned. With two sets of rotating cutting elements in the Sutliff et al. device, vegetation is simultaneously double-cut upon engagement of the blades and filaments and, in effect, mulched.
[0005] It is an object of the subject invention to provide a line trimmer having a cutting member with at least one rigid knife edge disposed on a guard that is non-rotatably mounted onto the line trimmer.
[0006] It is also an object of the subject invention to provide a line trimmer having a cutting member with at least one rigid knife edge disposed on a guard, with the knife edge being spaced from a plane defined by the flailing of a filament upon rotation of the cutting head.
SUMMARY OF THE INVENTION
[0007] The aforementioned objects are met by a line trimmer having a guard mounted thereto, with a cutting member having at least one rigid knife edge being disposed on the guard. The line trimmer also includes at least one filament which flails upon rotation of the cutting head. The knife edge is spaced from any plane defined by the flailing filament(s). Advantageously, the knife edge cuts vegetation in concert with the filament(s). As a variation, the cutting member may include a second knife edge which is disposed to pass through the plane(s) defined by the flailing filament(s) so as to trim excess length of the filament(s). Accordingly, the filament(s) will not extend beyond the guard of the line trimmer while flailing.
[0008] These and other features will be better understood through a study of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a perspective view of a line trimmer in accordance with the subject invention;
[0010] [0010]FIG. 2 is a bottom plan view of a guard, cutting head and filament of the line trimmer; and,
[0011] [0011]FIG. 3 is a side elevational view of the guard, cutting head, and filament.
DETAILED DESCRIPTION OF THE INVENTION
[0012] With reference to FIG. 1, a line trimmer is shown and generally designated with the reference numeral 10 . The line trimmer 10 , as is typical in the art, includes a drive shaft 12 , to which is mounted a cutting head 14 , a motor 16 for causing rotation of the cutting head 14 , and a guard 18 . The design and configuration of the drive shaft 12 , the cutting head 14 and the motor 16 are well known in the prior art and any such design and configuration may be used herein.
[0013] With reference to FIGS. 2 and 3, the cutting head 14 is generally disc-shaped with at least one filament 20 being mounted thereto and extending therefrom. Although a single filament 20 is shown in the FIG. 2, multiple filaments may be used, as is customary in the prior art and shown representatively in dashed lines in FIG. 3. The filament 20 is mounted to the cutting head 14 using any technique known in the prior art, such as being spool-mounted or threaded directly into the cutting head 14 .
[0014] Upon rotation of the cutting head 14 , the filament 20 is caused to flail. With the filament 20 flailing, a reference plane R is defined by the sweeping motion of the filament 20 . If multiple filaments 20 are used, each of the filaments 20 sweeps a reference plane R, the multiple reference planes R being coplanar, not coplanar, or a combination thereof.
[0015] The guard 18 is preferably non-rotatably mounted to the drive shaft 12 and is located in proximity to the cutting head 14 . The guard 18 radiates outwardly from the drive shaft 12 to at least sweep across an arc A. In particular, the guard 18 includes a top portion 22 , which radiates outwardly from the drive shaft 12 , and a skirt 24 which depends downwardly from the top portion 22 . The top portion 22 and the skirt 24 may be formed with various dimensions (i.e., the size of the arc A; the radius of the top portion 22 ; the height of the skirt 24 )—it must be noted that the guard 18 serves to protect a user from rocks, gravel, cut grass, and other debris which are hurled upwardly and/or outwardly from the cutting head 14 during use, so the extent of selected dimensions will dictate the amount of protection afforded by the guard 18 .
[0016] A cutting member 26 is mounted to the top portion 22 , and, preferably, the cutting member 26 is rigidly mounted to prevent movement thereof As shown in FIG. 2, the cutting member 26 has a rigid knife edge 28 which extends beyond the top portion 22 . The knife edge 28 may be of any cutting edge design known in the prior art which serves to cut vegetation in addition to the filament 20 as described below (e.g. a tapered edge; a dihedral edge). Preferably, the knife edge 28 (and the cutting member 26 ) are metallic, e.g., steel.
[0017] The knife edge 28 is located to oppose the movement of the filament 20 . In addition, as shown in FIG. 3, the knife edge 28 is located to be spaced from the reference planes R, and, preferably is disposed to be generally parallel to at least one of the reference plane(s) R. If multiple filaments are mounted to the cutting head 14 , the knife edge 28 is spaced from all of the reference planes R. As a result of this configuration, the flailing filament 20 strikes vegetation against the knife edge 28 resulting in the vegetation being cut both by the filament 20 and the knife edge 28 ; the knife edge 28 acts to second-cut vegetation in a mulching effect. If multiple filaments are used, the vegetation is further cut into smaller parts further enhancing the mulching effect.
[0018] The cutting member 26 can be mounted to the guard 18 using any technique known to those skilled in the art. Preferably, the cutting member 26 is mounted to a lower surface 29 of the top portion 22 of the guard 18 . Also, the cutting member 26 is formed with a rearwardly-extending moment arm 30 which extends generally in the same direction as the rotation of the cutting head 14 . More preferably, the moment arm 30 is formed to be located in proximity to the cutting head 14 . By extending in the same direction as the rotation of the cutting head 14 , the moment arm 30 counteracts force imparted thereto by the filament 20 (via impacted vegetation). In addition, the largest imparted force is located closest to the cutting head 14 , thus, requiring the most-significant counteraction in proximity thereto.
[0019] In a preferred arrangement, the knife edge 28 extends beyond an edge 32 which defines one limit of the arc A of the guard 18 . It is also preferred that the knife edge 28 be generally parallel to the edge 32 and be at least coextensive therewith.
[0020] As an additional variation, the cutting member 26 may be unitarily formed with a second knife edge 34 (preferably, metallic (e.g., steel)) that is disposed inside of the skirt 24 and passes through at least one of the reference planes R. As shown in FIG. 3, the knife edge 28 and the second knife edge 32 may define a L-shape with the cutting member 26 being formed from a unitary piece of metal. The second knife edge 34 is positioned to trim excess length of the filament(s) 20 . In this manner, no filament 20 will flail into, or beyond, the guard 18 .
[0021] As is readily apparent, numerous modifications and changes may readily occur to those skilled in the art, and hence it is not desired to limit the invention to the exact construction and operation as shown and described, and, accordingly, all suitable modification equivalents may be resorted to falling within the scope of the invention as claimed. | A cutting member is provided for mounting onto a guard for a line trimmer, the cutting member having at least one knife edge for cutting vegetation in concert with the flailing filament(s) of the trimmer. The knife edge is spaced from any planes swept by the flailing filaments. Additionally, the cutting member may be provided with a second knife edge that is positioned to trim excess length of the filament(s), thus ensuring no filament extends beyond the guard while in use. | 0 |
RELATED CASE
This application is a continuation-in-part of our original application, Ser. No. 243,776, filed Mar. 16, 1981, now U.S. Pat. No. 4,363,071.
BACKGROUND OF THE INVENTION
The invention relates to a static-dissipative web construction, suitable for example as a floor mat to enable personnel-accumulated static electricity to safely discharge from a person standing on the mat.
Various static-discharge mat constructions have been proposed, ranging from such highly conductive configurations as to permit the hazard of substantially instantaneous discharge, to slow-leaking constructions which exhibit undesirable dependence upon ambient humidity. Between these extremes, U.S. Pat. No. 4,208,696 to Lindsay, et al. describes a multi-layer static-dissipative web wherein an open-weave fabric in the form of cotton scrim is rendered electrically conductive (using carbon in a latex binder) and is interposed between upper and lower layers of relatively low conductivity, to produce mat constructions having an overall volume resistivity between 10 10 and 10 11 ohm-cm and surface resistance in the order of 10 8 ohms per square; Lindsay, et al. predicate their results on the foraminous nature of their conductive open-weave fabric. While the Lindsay, et al. product is in many respects satisfactory, it is prone to delamination, and for many applications an order of magnitude reduction in surface resistance is desirable, i.e., to the order of 10 7 ohms per square.
BRIEF STATEMENT OF THE INVENTION
It is an object of the invention to provide an improved static-dissipative web or mat of the character indicated.
It is a specific object to produce such a web or mat that is inherently not prone to delamination and which exhibits a surface resistance in the order of 10 7 ohms per square, as measured pursuant to ASTM Standard D257-76.
Another specific object is to provide such a web or mat construction having the further property of dust collection in the presence of pedestrian traffic thereon, as well as the property of repeated washability with conventional detergent solutions.
A general object is to provide such a web or mat construction which is of relative simplicity, which uses readily controllable and available component materials, and which is inherently relatively insensitive to environmental humidity.
The invention achieves the foregoing objects by employing a thin continuous film of carbon-compounded polymeric material, such as a bonded conductive flexible plate on the underside of an upper polymeric layer of low conductivity, the thin film having a surface resistance in the order of 10 2 ohms per square, as measured pursuant to said ASTM Standard D257-76. By employing polymeric material of the same nature, e.g., polyvinyl chloride in both these layers, as well as in an expanded conductive cushioning bottom layer, laminar bonding is optimized, and sensitivity to varying humidity is minimized. Also, the continuous nature of all layers, and the continuous nature of their interface bonding, provides a continuous volume within which electrostatic charge may dissipate and distribute over the thin film of the conductive intermediate layer, as distinguished from the discrete paths in which charge dissipation must be channeled in the foraminous-scrim network configuration of Lindsay, et al. A washable dust-collecting property is imparted by compounding with the upper polymeric layer a tackifying resin selected for its ability to remain thoroughly dispersed with the vinyl and plasticizer of the upper layer.
DETAILED DESCRIPTION
The invention will be described in detail for a preferred embodiment, in conjunction with the accompanying drawings, in which:
FIG. 1 is an enlarged sectional view through a mat construction of the invention;
FIG. 2 is an exploded view in perspective, to permit better identification of components of the construction of FIG. 1;
FIGS. 3a to 3f are views similar to FIG. 1, to illustrate successive stages in fabrication of the construction of FIG. 1; and
FIG. 4 is a schematic diagram to illustrate steps in a continuous process for making the construction of FIG. 1.
In FIGS. 1 and 2, the invention is shown in the form of a static-dissipating web or mat comprising three bonded layers 10-11-12 of differently conductive polymeric material, such as polyvinyl chloride. The top or upper layer 10 and the bottom or lower layer 12 may each be of the same solid-cast construction, but as shown, the lower layer 12 is an expanded version of the same polymeric material; and both layers 10-12 incorporate one or more conductive ingredients to enable each of layers 10-12 to have a volume resistivity in the range 10 7 to 10 12 ohm-cm. The inner or intermediate layer 11 is a thin film of preferably the same polymeric material containing an electrically conductive ingredient such as carbon black and exhibiting a surface resistance in the order of 10 2 ohms per square, as measured pursuant to ASTM Standard D257-76. A highly satisfactory conductive vinyl film for use at conductive layer 11 is known as Condulon, a trademark and product of Pervel Industries, Inc., Plainfield, Conn.
In a specific illustrative example, the solid upper and expanded lower layers 10-12 are both of polyvinyl chloride, with added conductive plasticizer, which may be commercially available products known as Markstat AL-15 or di-octyl-adipate (DOA)*, or a combination of the two. If mixed, it is preferred that the proportion by weight of the AL-15 to the DOA be 2:1, their combination accounting for 12 percent of the total dry-ingredient mix. In the illustrative example, the solid top layer 10 was 35 mils thick, the inner layer 11 was 2 mils thick, and the expanded lower layer was 88 mils thick, for an overall thickness of 125 mils. The upper and lower layers each exhibited a volume resistivity of about 10 9 ohm-cm and a surface resistance of 10 8 ohms per square, and the surface resistivity of the intermediate layer was 300 ohms per square. Overall surface resistance of the consolidated mat was measured at the exposed surface of top layer 10 to be 10 7 ohms per square, and the time for discharge of a 5 kV potential was 0.05 second.
A washable dust-collecting "sticky" or "tacky" property is imparted to the top layer 10 by adding a tackifying resin to the vinyl and plasticizer of the mix from which the upper level is formed. In general, any of the generally available tackifiers may be used, provided that it is selected for ability to remain thoroughly dispersed (i.e., virtually in solution) with the vinyl and plasticizer. We have thus far found it best to employ a pentaerythrital ester of a tall-oil rosin as the tackifying ingredient; an illustrative specific such product is commercially known as Zonester "100", being a product of tall-oil rosin manufacture, by Arizona Chemical Company, Fairlawn, N.J. In such compounding of Zonester "100" with the other top layer ingredients, the proportion of the tackifier should be in the range 25 to 45 percent of the total weight of ingredients, the preferred mix involving substantially one-third tackifier by weight. For the indicated materials below the lower end of the stated range, the exposed surface of top layer 10 is not sufficiently tacky; and above the upper end of the stated range, the tackifier is excessively present, being susceptible to take-up in shoe material of pedestrian traffic.
Continuous manufacture of the described web will be described in connection with FIGS. 3 and 4, commencing with a supply reel 15 of suitable casting web 16 continuously advancing from left to right, in the sense of FIG. 4. The casting web 16 may be a release-coated fabric or paper, and in the latter event the casting surface thereof is preferably embossed (as in FIGS. 3a), for ultimate aesthetic purposes at the exposed upper surface of layer 10.
A first casting of liquid-mixed polymeric-coat ingredients including the tackifying component is made at 17 and the same is cured or fused at 18, thereby establishing the solid layer 10 atop the casting paper 16, as shown in FIG. 3b. A separate supply of conductive film for inner layer 11 is available from a reel 19 and is guided for bonded lamination to layer 10, under heat and pressure, at heated squeeze rolls 20, to produce intermediate product shown in FIG. 3c. A second casting of liquid-mixed polymeric-coat ingredients (this time with an expanding component) is then made at 21, so that the developing product appears as in FIG. 3d, wherein the numeral 12' will be understood to designate the as-yet unexpanded liquid coat applied at 17. Passage through an expanding oven 22 enables controlled uniform expansion of the coat 12' to its ultimate thickness, as bottom layer 12, the same being consolidated in a fusing oven 23, with the appearance shown in FIG. 3e. The product is now completed by stripped removal of the casting paper and its separate accumulation at 24, leaving finished product (FIG. 3f) available for reel accumulation at 25. The now-exposed upper surface of the top layer 10 is sticky (tacky) to the touch, with great ability to retain dust and, on contact, to extract dust from shoes, wheel treads, or the like.
Static-dissipating vinyl mat material, produced as described is found to meet all stated objects. Static-dissipating conductivity is an order of magnitude (i.e., 10 times) better, that is, a surface resistance of 10 7 ohms per square, as compared with 10 8 ohms per square of a vinyl product of the Lindsay, et al. patent, and delamination is virtually impossible. Ambient humidity and/or water immersion are found to have no significant effect on electrical properties. The inherent capability of Condulon to discharge a 5 kV charge in 0.02 second enables design modification to increase the speed of electrostatic discharge, from the 0.05 second time observed for the described mat, either by creating a less-thick top layer 10 or by increasing the proportion of conductive plasticizer in the low-conductivity layers 10-12. Generally, the thickness range of layer 10 may be between 25 and 50 mils, the thickness range of layer 11 may be between 1 and 5 mils, and the thickness range of layer 12 may be between 25 and 125 mils, expansion being optional and dependent upon ultimate use.
The tacky exposed upper surface of top layer 10 is not only effective in removing dust or dirt particles from pedestrian footwear, wheel treads, and the like, but it also lends itself to repeated washing with commonly used detergent solutions, such as Spic & Span and Pinesol, for total regeneration of the tack. And of course, the sticky surface is static dissipative. Use is therefore particularly attractive at entrances to hospitals, electronic "clean rooms", and the like.
While the invention has been described in detail for the preferred embodiment, it will be understood that modifications may be made without departing from the scope of the invention. | The invention contemplates a washable dust-collecting multi-layer electrically conductive web or mat for safely and quickly discharging personnel-accumulated static electricity. An upper continuous polymeric layer of relatively low conductivity, in the order of 10 8 ohms per square and containing a tackifying resin thoroughly dispersed therein, is bonded to an underlying continuous polymeric layer of much greater conductivity, in the order of 10 2 ohms per square, and provision is made for electrically grounding the underlying layer, illustratively by casting to the intermediate layer a continuous bottom layer of expanded polymeric material of relatively low conductivity. | 1 |
BACKGROUND
[0001] 1. Field:
[0002] Various communication devices may benefit from network sharing. For example, network sharing may be beneficial for long term evolution on unlicensed band (LTE-U) and/or licensed-assisted access (LAA) cells operating on an unlicensed spectrum according to the third generation partnership project (3GPP). Further, LTE enhancements may be implemented for LAA to unlicensed spectrum, including LTE-U.
[0003] 2. Description of the Related Art:
[0004] The fast update of LTE in different regions of the world shows both that demand for wireless broad data is increasing, and that LTE is an extremely successful platform to meet that demand. At the same time, unlicensed spectrum is being considered by more cellular operators as a complementary tool to augment their service offering.
[0005] Unlicensed spectrum may not be able to match the qualities of the licensed regime. However, those solutions that allow an efficient use of unlicensed spectrum as a complement to licensed deployments have the potential to bring great value to 3GPP operators, and ultimately, to the 3GPP industry as a whole. Given the widespread deployment and usage of other technologies in unlicensed spectrum for wireless communications in society, it is envisioned that LTE would have to coexist with existing and future uses of unlicensed spectrum. Existing and new spectrum licensed for exclusive use by international mobile telecommunications (IMT) technologies will remain fundamental for providing seamless coverage, achieving the highest spectral efficiency, and ensuring the highest reliability of cellular networks through careful planning and deployment of high-quality network equipment and devices.
[0006] LAA should not impact/interfere with other systems, such as, for example, Wi-Fi, more than an additional Wi-Fi network on the same carrier. According to regulatory requirements, only certain amount of data can be transmitted without a listen before talk (LBT) mechanism, which may not be feasible for cell discovery and cell specific broadcast signaling. This may cause a problem that broadcast signaling space in unlicensed spectrum is limited. Further, it is assumed, for example, that primary synchronization channel (PSS)/secondary synchronization channel (SSS)/common reference signal (CRS) and system information are transmitted without LBT.
[0007] LTE-U/LAA is assumed to support network/radio access network (RAN) sharing which may be problematic because a public land mobile network (PLMN) identification (ID) may be quite long in size and all the necessary PLMN, such as, for example, a maximum of six (own PLMN +5 others), needs to be signaled.
[0008] As shown in FIG. 1 , PLMN identity is coded, in approximately 12 bytes total, in 3GPP TS 36.331, section 6.3.4. In the worst case scenario for network sharing, the network would need to signal 6 PLMN identities, which equate to 6×12 bytes, totaling 72 bytes.
[0009] Complementing the LTE platform with unlicensed spectrum is a possible choice under the above considerations. It would enable operators and vendors to leverage the existing or planned investments in LTE/evolved packet core (EPC) hardware in the radio and core network, especially if “Licensed-Assisted Access” is considered a secondary component carrier integrated into LTE.
SUMMARY
[0010] According to certain embodiments, a method may include preparing information related to a carrier and/or cell operating on a non-licensed spectrum. The method may also include providing, from a network element operating on a licensed spectrum to a user equipment, the information related to the carrier and/or cell operating on the non-licensed spectrum.
[0011] According to other embodiments, a method may include receiving, at a user equipment, information from a network element operating on a licensed spectrum. The method may also include processing the information. In certain embodiments, the information may be related to a carrier and/or cell operating on a non-licensed spectrum.
[0012] An apparatus, according to certain embodiments, may include at least one processor, and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to prepare information related to a carrier and/or cell operating on a non-licensed spectrum. The at least one memory and the computer program code may also be configured to, with the at least one processor, cause the apparatus at least to provide, from a network element operating on a licensed spectrum to a user equipment, the information related to the carrier and/or cell operating on the non-licensed spectrum.
[0013] An apparatus, according to other embodiments, may include at least one processor, and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to receive, at a user equipment, information from a network element operating on a licensed spectrum. The at least one memory and the computer program code may also be configured to, with the at least one processor, cause the apparatus at least to process the information. In certain embodiments, the information may be related to a carrier and/or cell operating on a non-licensed spectrum.
[0014] According to certain embodiments, a computer program may be embodied on a non-transitory computer readable medium. The computer program, when executed by a processor, may cause the processor at least to prepare information related to a carrier and/or cell operating on a non-licensed spectrum. The computer program, when executed by a processor, may also cause the processor at least to provide, from a network element operating on a licensed spectrum to a user equipment, the information related to the carrier and/or cell operating on the non-licensed spectrum.
[0015] According to other embodiments, a computer program may be embodied on a non-transitory computer readable medium. The computer program, when executed by a processor, may cause the processor at least to receive, at a user equipment, information from a network element operating on a licensed spectrum. The computer program, when executed by a processor, may also cause the processor at least to process the information. In certain embodiments, the information may be related to a carrier and/or cell operating on a non-licensed spectrum.
[0016] An apparatus, according to certain embodiments, may include means for preparing information related to a carrier and/or cell operating on a non-licensed spectrum. The apparatus may also include means for providing, from a network element operating on a licensed spectrum to a user equipment, the information related to the carrier and/or cell operating on the non-licensed spectrum.
[0017] An apparatus according to other embodiments, may include means for receiving, at a user equipment, information from a network element operating on a licensed spectrum. The apparatus may also include means for processing the information. In certain embodiments, the information may be related to a carrier and/or cell operating on a non-licensed spectrum.
[0018] A computer program product may, in certain embodiments, encode instructions for performing a process. The process may include preparing information related to a carrier and/or cell operating on a non-licensed spectrum. The process may also include providing, from a network element operating on a licensed spectrum to a user equipment, the information related to the carrier and/or cell operating on the non-licensed spectrum.
[0019] A computer program product may, in other embodiments, encode instructions for performing a process. The process may include receiving, at a user equipment, information from a network element operating on a licensed spectrum. The process may also include processing the information. In certain embodiments, the information may be related to a carrier and/or cell operating on a non-licensed spectrum.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For proper understanding of the invention, reference should be made to the accompanying drawings, wherein:
[0021] FIG. 1 illustrates coding of a PLMN-identity information element.
[0022] FIG. 2 illustrates a system according to certain embodiments.
[0023] FIG. 3 illustrates a method according to certain embodiments.
DETAILED DESCRIPTION
[0024] According to certain embodiments, information signaling for network sharing may be signaled, in broadcast and/or a dedicated manner, via a cell or system operating on the licensed spectrum. For example, in certain embodiments, a cell or system on the licensed spectrum may provide, via broadcast and/or dedicating signaling, information related to carrier and/or cell(s) on the non-licensed spectrum.
[0025] The information may include, for example: (1) information relevant when evaluating if a user equipment (UE) is allowed to access a cell and the scheduling of other system information; (2) radio resource configuration information; (3) cell re-selection and measurement reporting and measurement information common for intra-frequency, inter-frequency and/or inter-radio access technology (RAT) mobility; (4) relevant identity related information, such as, for example, physical cell identity (PCI), cell global identity (CGI), PLMN, frequency, and routing area update (RAU)/tracking area update (TAU)/location area update (LAU); (5) the information required to acquire multimedia broadcast multicast services (MBMS) control information associated with one or more multicast-broadcast single-frequency network (MBSFN) areas; (6) extended access class barring parameters; and (7) information relevant for traffic steering between evolved universal terrestrial radio access network (E-UTRAN), on an unlicensed spectrum, and wireless local area network (WLAN).
[0026] As a simple illustration, PLMN is described as an example of the information signaling for network sharing in the various embodiments described below, without limitation.
[0027] According to other embodiments, PLMN signaling for network sharing may be signaled, in a broadcast and/or dedicated manner, via a cell operating on the licensed spectrum. For example, a primary cell (Pcell) may signal a list of PLMNs operating on an unlicensed spectrum for network sharing. The UE may assume only cells belonging to the list of PLMNs are present, and may access any cell on the LTE-U band if there is a match between the list of PLMNs according to the UE's access rules.
[0028] Further, according to certain embodiments, PLMN signaling network sharing may be signaled, in a broadcast and/or a dedicated manner, via a cell operating on the licensed spectrum. In such a case, the PLMN information may be broadcasted in the cell on the LTE-U band in a time divided manner. For example, if two PLMNs share the same RAN in LTE-U, PLMN1 information may be broadcasted at different time intervals than PLMN2 information.
[0029] According to other embodiments, only a fraction of the PLMN information may be broadcasted in the LTE-U band. The fraction of the PLMN identity may refer to one of the PLMNs' broadcast on the licensed band in a system information block (SIB) from where the complete PLMN supported in the LTE-U band can be derived. Additionally, in other embodiments, a combination of any of the above-described signaling and broadcast options may be applied in PLMN signaling for network sharing that is signaled via a cell or system operating on the licensed spectrum.
[0030] In certain embodiments, PLMN identities may be signaled, in a broadcast and/or in a dedicated manner, with a corresponding index on a cell operating on a licensed spectrum. In other embodiments, only the index, which maps to the PLMN given, may be signaled on the cell operating on the unlicensed spectrum.
[0031] Additionally, according to certain embodiments, on the unlicensed spectrum, only a limited number of PLMNs may be broadcasted at the same transmission occasion. In particular, a number of broadcasted PLMNs may be indicated. For example, if there is an enhanced system information block (eSIB) broadcast on LAA with a periodicity of 40 ms, then every other eSIB could have a partial amount of PLMNs. In certain embodiments the partial amount of PLMNs may be approximately half the number of PLMNs.
[0032] Furthermore, according to other embodiments, there may be an indication that not all PLMNs are in one eSIB. This could be, for example, a bit or “index of eSIB” indicating which order number the SIB is.
[0033] According to certain embodiments, it may be assumed that LTE-U/LAA will utilize LTE carrier aggregation configurations and architecture where a (lower-power) secondary cell (Scell) operates in the unlicensed spectrum, and is either downlink (DL)-only or contains uplink (UL) and DL, and where the Pcell operates in the licensed spectrum and may be either LTE frequency division duplex (FDD) or LTE time division duplex (TDD). It may also be assumed that the LTE-U/LAA cell will transmit/broadcast system information and/or discovery signals consisting of, for example, PCI, PLMN, CGI, system frame number (SFN) timing, access parameters, LBT parameters etc.
[0034] Additionally, there may be several options for enabling network sharing for a cell, such as an Scell, operating on an unlicensed spectrum. As one option, a cell, such as a Pcell on a licensed spectrum may signal, via dedicated and/or broadcast signaling, a list of PLMNs for network sharing in an unlicensed spectrum. However, in order for the UE to understand which cell belongs to which PLMN on LAA, information for which cell the PLMN information is valid can also be included. The cell may also indicate for which PCI(s), such as for example, range of PCIs, indicated PLMN(s) are valid.
[0035] As a second option, a cell, such as a Pcell on a licensed spectrum may signal, via dedicated and/or broadcast signaling, a list of PLMNs with an index, or other common identifier, for network sharing. Further, a cell, such as an Scell on an unlicensed spectrum may broadcast only the index instead of the PLMN ID. In this case, the UE would be able to determine the PLMN based on the index provided.
[0036] As a third option, a cell, such as an Scell on an unlicensed spectrum may broadcast PLMNs in a changing manner. For example, the broadcasted PLMN may be different in different transmission occasions, including a limited number, such as, for example, one or two, etc., PLMNs may be broadcasted at a time. In addition, a number of broadcasted PLMNs could be indicated. For example, if there is eSIB broadcast on LAA with periodicity of 40 ms, then every other eSIB could have a partial amount of PLMNs, such as, for example, approximately half of the PLMNs. Further, there may be an indication that not all PLMNs are in one eSIB. This may be, for example, a bit or “index of eSIB” indicating which order number the SIB is. Alternatively, the full, or partly, PLMN information may be broadcasted on an LTE-U cell, such as, for example, in eSIB or detection signal, in a TDD manner.
[0037] The above-described embodiments may provide distinct advantages. For example, according to certain embodiments, it may be possible to optimize signaling for LTE-U/LAA. Further, according to other embodiments, it may be possible to have RAN/network sharing.
[0038] FIG. 2 illustrates a system according to certain embodiments of the invention. In one embodiment, a system may include multiple devices, such as, for example, at least one evolved node B (eNB) 210 or a base station or access point, and at least one UE 220 . According to certain embodiments, the UE may include any terminal device, such as, for example, a sensor, a smart meter, a personal digital assistant (PDA), smart phone, laptop computer, tablet computer, computer terminals and/or network devices.
[0039] Each of these devices may include at least one processor, respectively indicated as 214 and 224 . At least one memory may be provided in each device, and indicated as 215 and 225 , respectively. The memory may include computer program instructions or computer code contained therein. The processors 214 and 224 , and memories 215 and 225 , or a subset thereof, may be configured to provide means corresponding to the various blocks of FIG. 3 .
[0040] As shown in FIG. 2 , transceivers 216 and 226 may be provided, and each device may also include an antenna, respectively illustrated as 217 and 227 . Transceivers 216 and 226 may each, independently, be a transmitter, a receiver, or both a transmitter and a receiver, or a unit device that is configured both for transmission and reception.
[0041] Processors 214 and 224 may be embodied by any computational or data processing device, such as a central processing unit (CPU), application specific integrated circuit (ASIC), or comparable device. The processor may be implemented as a single controller, or a plurality of controllers or processors.
[0042] Memories 215 and 225 may be any suitable storage device, such as a non-transitory computer-readable medium. A hard disk drive (HDD), random access memory (RAM), flash memory, or other suitable memory may be used. The memories may be combined on a single integrated circuit as the processor, or may be separate from the one or more processors. Furthermore, the computer program instructions stored in the memory and which may be processed by the processors may be any suitable form of computer program code, for example, a compiled or interpreted computer program written in any suitable programming language.
[0043] The memory and computer program instructions may be configured, with the processor for the particular device, to cause a hardware apparatus such as eNB 210 and UE 220 , to perform any of the processes described herein (see, for example, FIG. 3 ). Therefore, in certain embodiments, a non-transitory computer-readable medium may be encoded with computer instructions that, when executed in hardware, perform a process such as one of the processes described herein. Alternatively, certain embodiments of the invention may be performed entirely in hardware.
[0044] Furthermore, although FIG. 2 illustrates a system including an eNB 210 and UE 220 , embodiments of the invention may be applicable to other configurations, and configurations involving additional elements. For example, not shown, additional UEs and/or eNBs may be present.
[0045] FIG. 3 illustrates a method according to certain embodiments. As shown in FIG. 3 , a method may include, at 310 , preparing the information. The information may be related to a carrier and/or cell operating on a non-licensed spectrum. The method may also include at 320 , providing, from a network element operating on a licensed spectrum to a user equipment, the information related to the carrier and/or cell operating on the non-licensed spectrum. In certain embodiments, the network element may include an eNB, base station or access point.
[0046] FIG. 3 also illustrates a method that may include, at 330 , receiving, at a user equipment, information from a network element. The network element may be operating on a licensed spectrum. The method may also include at 340 , processing the information. In certain embodiments, the information may be related to a carrier and/or cell operating on a non-licensed spectrum.
[0047] It will be readily understood that the components of the invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the above detailed description of the embodiments of systems, methods, apparatuses, and computer program products for network sharing for LTE-U/LAA cells operating on unlicensed spectrum, as represented in the attached figures, is not intended to limit the scope of the invention, but is merely representative of selected embodiments of the invention.
[0048] The features, structures, or characteristics of certain embodiments described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, the usage of the phrases “certain embodiments,” “some embodiments,” or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. Thus, appearances of the phrases “in certain embodiments,” “in some embodiments,” “in other embodiments,” or other similar language, throughout this specification do not necessarily all refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0049] Additionally, if desired, the different functions discussed above may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the described functions may be optional or may be combined. As such, the above description should be considered as merely illustrative of the principles, teachings and embodiments of this invention, and not in limitation thereof.
[0050] One having ordinary skill in the art will readily understand that the invention as discussed above may be practiced with steps in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the invention has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of the invention. In order to determine the metes and bounds of the invention, therefore, reference should be made to the appended claims.
[0051] Glossary
[0052] 3GPP Third Generation Partnership Project
[0053] ASIC Application Specific Integrated Circuit
[0054] CGI Cell Global Identity
[0055] CPU Central Processing Unit
[0056] CRS Common Reference Signal
[0057] DL Downlink
[0058] eNB Evolved Node B
[0059] EPC Evolved Packet Core
[0060] eSIB Enhanced Signal Information Block
[0061] E-UTRAN Evolved Universal Terrestrial Radio Access Network
[0062] FDD Frequency Division Duplex
[0063] HDD Hard Disk Drive
[0064] ID Identification
[0065] IMT International Mobile Telecommunications
[0066] LAA Licensed Assisted Access
[0067] LAU Location Area Update
[0068] LBT Listen Before Talk
[0069] LTE Long Term Evolution (a.k.a., E-UTRA)
[0070] LTE-U LTE on Unlicensed Band
[0071] MBMS Multimedia Broadcast Multicast Services
[0072] MBSFN Multicast-Broadcast Single-Frequency Network
[0073] Pcell Primary Cell
[0074] PDA Personal Digital Assistant
[0075] PCI Physical Cell Identity
[0076] PLMN Public Land Mobile Network
[0077] PSS Primary Synchronization Channel
[0078] RAM Random Access Memory
[0079] RAN Radio Access Network
[0080] RAT Radio Access Technology
[0081] RAU Routing Area Update
[0082] Scell Secondary Cell
[0083] SFN System Frame Number
[0084] SIB System Information Block
[0085] SSS Secondary Synchronization Channel
[0086] TAU Tracking Area Update
[0087] TDD Time Division Duplex
[0088] UE User Equipment
[0089] UL Uplink
[0090] WLAN Wireless Local Area Network | Various communication devices may benefit from network sharing. For example, network sharing may be beneficial for long term evolution on unlicensed band (LTE-U) and/or licensed-assisted access (LAA) cells operating on an unlicensed spectrum according to the third generation partnership project. Further, LTE enhancements may be implemented for LAA to unlicensed spectrum, including LTE-U. A method may include preparing information related to a carrier and/or cell operating on a non-licensed spectrum. The method may also include providing, from a network element operating on a licensed spectrum to a user equipment, the information related to the carrier and/or cell operating on the non-licensed spectrum. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a door driving control apparatus for controlling, in a train or the like, the opening/closure driving of a vehicle door that is opened and closed by a motor.
2. Description of the Related Art
In automatic opening/closing doors for getting passengers on/off of trains, automobiles, etc., from the viewpoint of power saving, protection from burning of door driving motors, and prevention of erroneous operation during running, usually each door is driven by supplying electric power to a door driving motor only in opening or closing it and in other situations (the door is closed) the door is locked mechanically by means of a locking device such as a lock pin and no electric power is supplied to the door driving motor.
FIG. 6 shows the configuration of a conventional door driving control apparatus for a railway vehicle. The door driving control apparatus 10 is equipped with an operation instruction computing section 11 , a power conversion section 12 , and a communication interface 14 and is connected to a power source 21 , a linear motor 2 , a position detector 5 which are provided on a vehicle body 20 and a train control apparatus 22 provided in a motorman's cab.
Linear motor 2 , a movable portion of which is connected to a link portion 3 provided on a door 1 , opening/closure-drives the door 1 . The door 1 is provided with a locking device 7 for fixing the door 1 mechanically. The position detector 5 detects a position and a speed of the movable portion of the linear motor 2 and outputs a thus-acquired door position detection value S 1 to the operation instruction computing section 11 .
Among three phase lines (having U, V, and W phases) which connect the power conversion section 12 to the linear motor 2 , output current detectors 4 are connected to the U-phase and W-phase lines, respectively. Output current detection values S 2 obtained by detecting a U-phase current and a W-phase current with the output current detectors 4 are input to the operation instruction computing section 11 .
With the above configuration, when receiving a door operation instruction signal S 3 from the train control apparatus 22 , the operation instruction computing section 11 performs door speed feedback control using the door position detection value Si and the output current detection values S 2 . The power conversion section 12 converts the power from the power source 21 according to this control. The linear motor 2 is supplied with converted power and its driving is thereby controlled. The door 1 is opening/closure-driven as a result of this driving of the linear motor 2 .
Door driving control apparatus 10 for controlling the opening and closing of the door 1 is provided for each door (e.g., each of first to eighth doors) as indicated by reference symbols 10 - 1 to 10 - 8 in FIG. 7 and is connected to the train control apparatus 22 via the communication interface 14 .
As exemplified in FIG. 8 , door installation positions are discriminated from each other by setting addresses A 1 -A 8 for the respective door positions in each car and storing the addresses A 1 -A 8 in the respective door driving control apparatus 10 - 1 to 10 - 8 .
In automatic opening/closing doors for trains, automobiles, etc., when a high pressure is exerted on the door 1 by passengers in a fully jammed car, for example, and the friction of the door 1 is thereby made unduly high or a foreign object is pinched by the door 1 , correct operation of the door 1 is secured by increasing the driving force for the door 1 , opening and closing the door again (i.e., temporarily opening the door 1 being closed and starting a closing operation again after a lapse of a prescribed time with an assumption that a passenger, a bag, or the like has escaped or has been removed) after increasing the driving force for a prescribed time, or performing a like operation. However, when foreign objects are pinched by plural doors 1 , the driving force is increased for all of those doors 1 and hence the total power consumption becomes large.
As shown in FIG. 9 , usually the plural door driving control apparatus 10 - 1 to 10 - 8 of a car are connected to the power source 21 which is provided for the same vehicle body as the door driving control apparatus 10 - 1 to 10 - 8 are provided on, and other apparatus such as an air conditioner 31 and an inverter apparatus for fluorescent lamps are also connected to the power source 21 . Therefore, if the total power consumption becomes large as a result of an increase in the door driving force for plural doors, the voltage of the power source 21 decreases, which may adversely affect the operation of other apparatus in the same car as exemplified by flickering of fluorescent lamps.
Exemplary countermeasures against the above problem are disclosed in JP-A-2005-145240 and JP-A-2005-73381. In JP-A-2005-145240, the fact that high torque is being output for one or some of the doors of the same power supply system is communicated between the door driving control apparatus 10 - 1 to 10 - 8 via the communication interfaces 14 over the inter-car network. Each door driving control apparatus outputs low torque while high torque is being output for another or other doors. In this manner, adjustments are made so that the power consumption of the entire car does not become unduly large.
In JP-A-2005-73381, each of the door driving control apparatus 10 - 1 to 10 - 8 restrict output torque in accordance with its input voltage or input current. In this manner, adjustments are made so that the power consumption of the entire car does not become unduly large.
However, the information that can be communicated over the inter-car network depends on the vehicle type. Therefore, information as to whether high torque is being output may not be available in certain vehicle types, in which case the technique of JP-A-2005-145240 cannot be utilized.
In the technique of JP-A-2005-73381, when an attempt is made to output high torque for all doors, the power supply voltage is lowered and the output torque is thereby restricted. This results in a problem that with restricted output torque the doors may not be operated or locked.
SUMMARY OF THE INVENTION
The present invention has been made to solve the above problems, and an object of the invention is therefore to provide a door driving control apparatus which makes it possible to output high torque for each door and thereby operate it and lock it reliably without reduction in power supply voltage even in the case where information as to whether high torque is being output cannot be communicated between door driving control apparatus.
To attain the above object, the invention provides a door driving control apparatus which drives a door closed by setting door opening/closing drive torque to ordinary torque or high torque when opening/closing driving of plural doors that are driven by respective motors is controlled, comprising setting means for setting a high torque application period for the door so that periods of high-torque closure driving of respective doors or predetermined door groups do not overlap with each other, and instructing means for issuing an instruction to drive the door closed with high torque only during the high torque application period thus set.
With this configuration, when high torque is necessary for plural doors, those doors can be driven open and closed with high torque in such a manner that the periods of high-torque driving of those doors do not overlap with each other even in the case where information as to whether high torque is being output cannot be communicated between the door driving control apparatus. Therefore, the power supply voltage does not decrease due to overlap between periods of high-torque driving and hence each door can be operated with high torque.
In the above door driving control apparatus, the instructing means may be such as to issue, at the end of the high torque application period, an instruction to perform a door re-opening and closing operation.
With this measure, a re-opening and closing operation is performed additionally at the end of a high torque application period in the control that prevents overlap between high-torque driving states of plural doors. Therefore, when foreign objects are pinched by plural doors, the plural doors can be closed with high torque without causing a decrease in power supply voltage and the foreign objects can be removed more properly.
In the above door driving control apparatus, the instructing means may be such as to issue an instruction to perform ordinary door closing driving without employing high torque if a door drive speed exceeds a predetermined speed in the high torque application period.
With this measure, an ordinary closing operation is performed if the door drive speed exceeds the predetermined speed in a high torque application period, that is, if a foreign object is removed during a closing operation of high torque. This dispenses with an unnecessary re-opening and closing operation and hence prevents useless power consumption.
As described above, the invention provides an advantage that high torque can be output for each door and each door can thereby be operated and locked reliably without reduction in power supply voltage even in the case where information as to whether high torque is being output cannot be communicated between door driving control apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B show the configuration of a door driving control apparatus for a railway vehicle according to a first embodiment of the present invention.
FIGS. 2A to 2F are a timing chart illustrating opening/closing driving for plural doors of the door driving control apparatus according to the first embodiment.
FIG. 3 is a flowchart of a process where a door large output permission flag is set by an operation instruction computing section of the door driving control apparatus according to the first embodiment.
FIG. 4 is a block diagram showing the configuration of an operation instruction computing section of a door driving control apparatus for a railway vehicle according to a second embodiment of the invention.
FIGS. 5A to 5H are a timing chart illustrating opening/closing driving for plural doors of the door driving control apparatus according to the second embodiment.
FIG. 6 shows the configuration of a conventional door driving control apparatus for a railway vehicle.
FIG. 7 shows how plural conventional door driving control apparatus for a railway vehicle are connected to a train control apparatus via communication lines.
FIG. 8 shows an exemplary manner of assignment of addresses to respective doors that are controlled by the door driving control apparatus.
FIG. 9 shows an exemplary configuration of connections of door driving control apparatus, a power source, and other apparatus of the same car.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be hereinafter described with reference to the drawings.
First Embodiment
FIGS. 1A and 1B show the configuration of a door driving control apparatus for a railway vehicle according to a first embodiment of the invention.
The door driving control apparatus 40 of FIG. 1A is equipped with an operation instruction computing section 41 , a power conversion section 12 , and a communication interface 14 , and is different from the conventional door driving control apparatus 10 of FIG. 6 in that, as shown in FIG. 1B , the operation instruction computing section 41 is equipped with a timer section 43 , a comparison/judgment section 44 , a flag setting section 45 for setting and resetting a door large output permission flag 45 a , and a door opening/closure instructing section 46 .
The timer section 43 starts a timer operation upon reception of a door operation instruction signal S 3 from the train control apparatus 22 . The timer section 43 is configured so as to be cleared if it expires in a state that the door large output permission flag 45 a is set.
An offset value, which is output from the train control apparatus 22 in accordance with a door installation position recognized by a corresponding one of the addresses A 1 -A 8 (see FIG. 8 ), is set in the timer section 43 . The offset value is output when there is no door operation instruction signal S 3 . The offset values serve to deviate output timings of high torque for doors of one car from each other and thereby prevent the doors from causing a heavy load collectively when they are closed. That is, the doors are closed with timings that are deviated from each other in order on a door-by-door basis or a door group basis.
The comparison/judgment section 44 compares a timer measurement time S 5 of the timer section 43 with a preset door large output setting time S 6 and judges whether or not the timer measurement time S 5 is longer than or equal to the preset door large output setting time S 6 .
If the comparison/judgment section 44 judges that the timer measurement time S 5 is not longer than or equal to the preset door large output setting time S 6 , the flag setting section 45 keeps a state that the door large output permission flag 45 a is reset. If the comparison/judgment section 44 judges that the timer measurement time S 5 is longer than or equal to the preset door large output setting time S 6 , the flag setting section 45 sets the door large output permission flag 45 a.
As shown in FIG. 2A , the door large output permission flag 45 a is set at time t 1 . When the timer section 43 expires at time t 3 , the timer section 43 is cleared. As a result, the timer measurement time S 5 becomes shorter than the door large output setting time S 6 and hence the door large output permission flag 45 a is reset immediately at time t 3 .
At this time, if the input of the door operation instruction signal S 3 is continuing, the timer section 43 again starts a timer operation. If it is judged again at time t 4 that the timer measurement time S 5 is longer than or equal to the door large output setting time S 6 , the door large output permission flag 45 a is set and kept set until the timer section 43 expires at time t 6 .
That is, the door large output permission flag 45 a is kept in a reset state during a time width (called “reset time width”) from the start of a timer operation of the timer section 43 to the end of the door large output setting time S 6 , and is rendered in a set state during a time width (called “set time width”) from a time point when the timer measurement time S 5 becomes greater than or equal to the door large output setting time S 6 (i.e., the above-mentioned end of the door large output setting time S 6 ) to a time point when the timer section 43 expires Therefore, the set time width and the reset time width appear repeatedly and alternately. Each of the set time width and the reset time width can be varied by changing the door large output setting time S 6 .
The door opening/closing instructing section 46 outputs a door output instruction value S 7 for opening or closing the door 1 to the power conversion section 12 in response to a door operation instructing signal S 3 as an opening/closure instruction. Furthermore, the door opening/closure instructing section 46 outputs a door output instruction value S 7 for driving the door 1 with high torque to the power conversion section 12 if the door drive speed which can be recognized on the basis of a door position detection value S 1 becomes lower than a prescribed value in a state that the door large output permission flag 45 a is set.
A process that the door large output permission flag 45 a is set by the above-configured operation instruction computing section 41 will be described with reference to a flowchart of FIG. 3 .
First, if it is judged at step ST 1 that no door operation instruction signal S 3 is input to the operation instruction computing section 41 , at step ST 2 offset values which are output from the train control apparatus 22 in accordance with the installation positions of the respective doors 1 are set in the timer sections 43 for the respective doors 1 .
On the other hand, if a door operation instruction signal S 3 is input, the timer section 43 starts a timer operation at step ST 3 .
After the timer operation was started, the comparison/judgment section 44 judges at step ST 4 whether or not a timer measurement time S 5 is longer than or equal to the door large output setting time S 6 . If it is judged that the timer measurement time S 5 is not longer than or equal to the door large output setting time S 6 , at step ST 5 the flag setting section 45 keeps the door large output permission flag 45 a in a reset state.
On the other hand, if it is judged that the timer measurement time S 5 is greater than or equal to the door large output setting time S 6 , at step ST 6 the flag setting section 45 sets the door large output permission flag 45 a . If the timer section 43 expires at step ST 7 , the timer section 43 is cleared at step ST 8 .
Next, an operation that the door 1 is opened or closed after the door large output permission flag 45 a was set in the above-described manner will be described with reference to the timing chart of FIGS. 2A to 2F .
FIGS. 2A to 2F relate to only the first and second doors. More specifically, FIGS. 2A and 2D show how the door large output permission flags 45 a for those doors are set so as not to overlap with each other in time. FIGS. 2C and 2F show how high torque is output while the door large output permission flags 45 a are set as shown in FIGS. 2A and 2D . For comparison with the control according to this embodiment, FIGS. 2B and 2E show how high torque is output in a conventional control.
It is assumed that, as shown in FIGS. 2A and 2D , the door large output permission flag for the first door (first door large output permission flag) 45 a is set during a set time width from time t 1 to t 3 and a set time width from time t 4 to t 6 and the door large output permission flag for the second door (second door large output permission flag) 45 a is set during a set time width from time t 0 to t 1 and a set time width from time t 3 to t 4 .
It is assumed that at time t 0 a door operation instruction value S 3 which is a door closure instruction is input from the train control apparatus 22 to the door opening/closure instructing sections 46 , whereby the first and second doors are subjected to closing operations of ordinary torque (indicated by level “L”).
Also assume that both doors collide with certain foreign objects at time t 2 during the closing operations and the foreign objects are removed and ordinary operations are restored at time t 5 . In the conventional control, as shown in FIGS. 2B and 2E , both doors are subjected to closing operations with high torque (indicated by level “H”) while the foreign objects are kept pinched (from time t 2 to t 5 ). Therefore, in the conventional control, high-torque states of the plural doors overlap with each other in time. A high power is consumed and the power supply voltage of the car concerned thereby decreases during the overlap period.
In contrast, in the embodiment as shown in FIG. 2C , the first door is subjected to a closing operation of high torque only while the door large output permission flag 45 a is set (i.e., from time t 2 to t 3 and from time t 4 to t 5 ). And, as shown in FIG. 2F , the second door is subjected to a closing operation of high torque only during a period from time t 3 to t 4 that does not overlap with the high-torque closing operation periods for the first door. In this manner, the high-torque states of the plural doors do not overlap with each other in time.
As described above, according to the door driving control of the door driving control apparatus 40 according to the first embodiment, when high torque is necessary for plural doors, those doors can be opening/closure-driven with high torque in such a manner that the periods of driving of those doors do not overlap with each other even in the case where information as to whether high torque is being output cannot be communicated between the door driving control apparatus 40 . Therefore, the power supply voltage does not decrease and each door can be operated with high torque.
As a result, unlike in the conventional case, an event can be avoided where the output torque is restricted due to reduction in power supply voltage and doors cannot be operated properly (they are not locked) In other words, the doors can be locked reliably.
Second Embodiment
FIG. 4 is a block diagram showing the configuration of an operation instruction computing section of a door driving control apparatus for a railway vehicle according to a second embodiment of the invention.
The operation instruction computing section instructing means 51 of FIG. 4 is equipped with, in addition to the components 43 - 46 of the operation instruction computing section 41 of FIG. 1B , a speed calculating section 53 , a speed comparison/judgment section 54 , a flag setting section 55 for setting and resetting a door foreign object detection flag 55 a , and a flag status judging section 56 . However, in FIG. 4 , the door opening/closing instructing section of the second embodiment is denoted by reference numeral 57 because as described later its processing is different from the processing of the door opening/closure instructing section 46 shown in FIG. 1 .
The speed calculating section 53 calculates a door speed S 8 on the basis of a door position detection value S 1 .
The speed comparison/judgment section 54 compares the calculated door speed S 8 with a preset threshold speed S 9 , judges whether the calculated door speed S 8 is less than or equal to the threshold speed S 9 , and outputs a judgment result.
If the speed comparison/judgment section 54 judges that the door speed S 8 is less than or equal to the threshold speed S 9 , the flag setting section 55 sets the door foreign object detection flag 55 a.
The flag status judging section 56 judges the set/reset statuses of the door large output permission flag 45 a and the door foreign object detection flag 55 a.
The door opening/closing instructing section 57 outputs a door output instruction value S 7 for closing the door 1 with high torque only if the flag status judging section 56 judges that both of the door large output permission flag 45 a and the door foreign object detection flag 55 a are set. If a transition occurs from a state of both flags 45 a and 55 a being set to a state of the door large output permission flag 45 a being reset, the door opening/closing instructing section 57 outputs a door output instruction value S 7 for causing a re-opening and closing operation in which the door 1 will be opened for a prescribed time and then subjected to an ordinary closing operation (output torque: not high torque) If a transition occurs from a state of both flags 45 a and 55 a being set to a state of the door foreign object detection flag 55 a being reset, the door opening/closure instructing section 57 outputs a door output instruction value S 7 for subjecting the door 1 to an ordinary closing operation.
A re-opening and closing operation which is caused by the above-configured operation instruction computing section 51 when foreign objects are pinched by doors will now be described with reference to a timing chart of FIGS. 5A to 5H .
FIGS. 5A to 5H relate to only the first and second doors. More specifically, FIGS. 5A and 5E show how the door large output permission flags 45 a for those doors are set so as not to overlap with each other in time. FIGS. 5B and 5F show how the door foreign object detection flags 55 a are set. FIGS. 5D and 5H show how high torque is output while the flags 45 a and the flags 55 a are set as shown in FIGS. 5A and 5E and FIGS. 5B and 5F . For comparison with the control according to this embodiment, FIGS. 5C and 5G show how high torque is output in a conventional control.
It is assumed that at time t 0 a door operation instruction value S 3 which is a door closure instruction is input from the train control apparatus 22 to the door opening/closure instructing sections 46 , whereby the first and second doors are subjected to closing operations of ordinary output torque (indicated by level “L”).
Operations to be performed after time t 0 will now be described starting from an operation relating to the first door. If the first door collides with a certain foreign object during the closing operation, the door speed decreases. If the speed comparison/judgment section 54 judges at time t 1 that the door speed S 8 has become less than or equal to the threshold speed S 9 , the flag setting section 55 sets the first door foreign object detection flag 55 a as shown in FIG. 5B .
Then, when the first door large output permission flag 45 a is set at time t 2 as shown in FIG. 5A , the flag status judging section 56 judges that both of the first door large output permission flag 45 a and the first door foreign object detection flag 55 a are set. Receiving this judgment result, the door opening/closing instructing section 57 outputs to the power conversion section 12 a door output instruction value S 7 for closing the first door with high torque. The first door is closed with high torque (indicated by level “H” in FIG. 5D ), which is a foreign object pressing operation.
When the flag status judging section 56 judges at time t 5 that the first door large output permission flag 45 a has made a transition to a reset state (see FIG. 5A ), the door opening/closing instructing section 57 outputs a door output instructing value S 7 for subjecting the first door to a re-opening and closing operation. As a result, as shown in FIG. 5D , the first door is subjected to a re-opening and closing operation including an opening operation from time t 5 to t 6 . The door speed increases during the opening operation. When the speed comparison/judgment section 54 finds the speed increase, the flag setting section 55 resets the first door foreign object detection flag 55 a at time t 5 as shown in FIG.
Then, the first door collides with the foreign object again and the door speed decreases. If the speed comparison/judgment section 54 judges at time t 7 that the door speed S 8 has become lower than or equal to the threshold speed S 9 , the flag setting section 55 sets the first door foreign object detection flag 55 a as shown in FIG. 5B . While the first door large output permission flag 45 a is kept set from time t 9 to t 10 as shown in FIG. 5A , the first door is subjected to a closing operation of high torque in response to a door output instruction value S 7 for closing the first door with high torque (see FIG. 5D ).
Next, an operation relating to the second door will be described. As already described above in the first embodiment, for the second door, as shown in FIG. 5E , the second door large output permission flag 45 a is set in the reset periods of the first door large output permission flag 45 a (see FIG. 5A ) to avoid overlaps.
If the second door collides with a certain foreign object during the closing operation which is performed after time t 0 , the door speed decreases. If the speed comparison/judgment section 54 judges at time t 1 that the door speed S 8 has become lower than or equal to the threshold speed S 9 , the flag setting section 55 sets the second door foreign object detection flag 55 a as shown in FIG. 5F .
At this time, the flag status judging section 56 judges that both of the second door large output permission flag 45 a and the second door foreign object detection flag 55 a are set. Receiving this judgment result, the door opening/closing instructing section 57 outputs a door output instruction value S 7 for closing the second door with high torque. The second door is closed with high torque (indicated by level “H” in FIG. 5H ), which is a foreign object pressing operation.
When the flag status judging section 56 judges at time t 2 (i.e., soon after time t 1 ) that the second door large output permission flag 45 a has made a transition to a reset state (see FIG. 5E ), the door opening/closure instructing section 57 outputs a door output instructing value S 7 for subjecting the second door to a re-opening and closing operation. As a result, as shown in FIG. 5H , the second door is subjected to a re-opening and closing operation including an opening operation from time t 2 to t 3 . The door speed increases during the opening operation When the speed comparison/judgment section 54 finds the speed increase, the flag setting section 55 resets the second door foreign object detection flag 55 a at time t 2 as shown in FIG. 5F .
Then, the second door collides with the foreign object again and the door speed decreases. If the speed comparison/judgment section 54 judges at time t 4 that the door speed S 8 has become lower than or equal to the threshold speed S 9 , the flag setting section 55 sets the second door foreign object detection flag 55 a as shown in FIG. 5F . Assume that the second door large output permission flag 45 a is kept set from time t 5 to t 9 as shown in FIG. 5E and the foreign object is removed and the second door foreign object detection flag 55 a is reset at time t 8 as shown in FIG. 5F .
In this case, the second door is subjected to a closing operation of high torque from the period from time t 5 to t 8 when the flags 45 a and 55 a are set (see FIG. 5H ). At time t 8 , only the second door foreign object detection flag 55 a makes a transition to a reset state and hence the door opening/closure instructing section 57 outputs a door output instruction value S 7 for subjecting the second door to an ordinary closing operation (see FIG. 5H ) The second door is thereby subjected to an ordinary closing operation.
As described above, according to the door driving control of the door driving control apparatus 40 according to the second embodiment, high-torque states of the first and second doors are prevented from overlapping with each other in time. Furthermore, when the door large output permission flag 45 a is reset while the door is subjected to a closing operation of high torque, the closing operation is finished and a re-opening and closing operation is started immediately. When foreign objects are pinched by plural doors, this measure makes it possible to close the plural doors with high torque without decrease in power supply voltage and to remove the foreign objects more properly. If a foreign object is removed during a closing operation of high torque, an ordinary closing operation is performed. This dispenses with an unnecessary re-opening and closing operation and hence prevents useless power consumption.
In the conventional case, as shown in FIGS. 5C and 5G , a high-torque closing operation is performed while the door foreign object detection flag 55 a is set. Therefore, high-torque states of plural doors overlap with each other in time. A high power is consumed and the power supply voltage of the car concerned thereby decreases during the overlap periods.
It should, of course, be appreciated that the invention may be practiced otherwise than as specifically disclosed herein without departing from the scope thereof. | In controlling, with recognition of their installation positions, the opening/closing driving of plural doors that are driven by respective linear motors, each door is driven closed by switching the door opening/closing drive torque to high torque if the drive speed of the door has become less than or equal to a prescribed speed. In doing so, operation instruction computing sections set high torque application periods for respective doors so that the periods of high-torque closure driving of respective doors or predetermined door groups do not overlap with each other, and issue instructions to drive the doors closed with high torque only during the high torque application periods. | 4 |
FIELD OF THE INVENTION
This invention relates to a reinforcing ring for a plastic fitting and a plastic fitting incorporating such a reinforcing ring. The invention has particular utility with respect to fire sprinkler heads in buildings, although it will also have utility with other applications.
BACKGROUND OF THE INVENTION
In the past, plastic fittings have been used for receiving a threaded male part, typically a threaded pipe. Also, in the past, reinforcing rings have been used to reinforce plastic fittings, such as described in U.S. Pat. Nos. 5,582,439 and 6,866,305 to Spears and U.S. Patent Application 2004/0051316 to Spears. Also, U.S. Pat. No. 4,682,797 to Hildner and U.S. Pat. No. 6,186,558 to Komolrochanapom, as well as U.S. Patent Application 2003/0184085 to Thompson, disclose a reinforcing ring used with plastic fittings.
Although reinforcing rings that have been made in the past, and used with plastic fittings, there have been problems with such rings and fittings, particularly relating to cross-threading and shearing. Therefore, the present invention provides an improved reinforcing ring and an improved fitting incorporating the reinforcing ring.
One problem is that when the male part which is being inserted into the plastic fitting is over-tightened, there is a tendency for the plastic fitting to shear.
Also, cross-threading occurs when the thread axis of the male part is not properly aligned relative to the female fitting's thread axis. All plastic thread design is susceptible to cross-threading. One way of at least reducing the risk of cross-threading is to guide the male part to be axially in line with the female fitting. Another way to lessen the likelihood of cross-threading is to reinforce the first few plastic threads of the fitting with a harder material. The present invention has been able to successfully combine both of these approaches to provide an improved method of reducing the likelihood of cross-threading using only a single starter thread. None of the prior art reinforcing rings use only a single starter thread.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to at least partially overcome the disadvantages of the prior art. Also, it is an object of this invention to provide an improved reinforcing ring for plastic fittings and an improved plastic fitting incorporating the reinforcing ring.
Accordingly, in one of its aspects, this invention resides in providing a reinforcing ring for a plastic fitting, comprising: a first tubular portion; a radial portion extending radially inwardly from a forward end of the tubular portion; a guide portion extending rearwardly from a radially-inner region of the radial portion; and a starter thread extending radially inwardly from a rearward end of the guide portion.
In a further aspect, the present invention resides in providing a plastic fitting for receiving a threaded male part, comprising: a plastic body having inner plastic threads for receiving the male part in threaded engagement; and a reinforcing ring as described above wherein the first tubular portion of the reinforcing ring surrounds at least a portion of the plastic body.
Further aspects of the invention will become apparent upon reading the following detailed description and drawings which illustrate the invention and preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, which illustrate embodiments of the invention:
FIG. 1 is a perspective view of a preferred embodiment of the reinforcing ring of the invention;
FIG. 2 is a top view of a preferred embodiment of the reinforcing ring of the invention;
FIG. 3 is a cross-sectional view though line A-A in FIG. 2 of a preferred embodiment of the reinforcing of the invention;
FIG. 4 is another cross-sectional view through line B-B in FIG. 2 of a preferred embodiment of the reinforcing ring of the invention;
FIG. 5 is a detail of a portion “C” from FIG. 4 of one embodiment of the reinforcing ring of the invention;
FIG. 6 is a side view of a preferred plastic fitting of the invention;
FIG. 7 is a cross-sectional view through line D-D in FIG. 6 of a preferred embodiment of a fitting of the invention;
FIG. 8 is a detail of a portion “E” from FIG. 7 of a preferred embodiment of the fitting of the invention; and
FIG. 9 shows a metal sheet from which a preferred embodiment of the reinforcing ring of the invention may be stamped.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1 , one embodiment of the present invention relates to a reinforcing ring 10 for a plastic fitting 12 . As best seen in FIG. 3 , the reinforcing ring 10 comprises a first tubular portion 14 and a radial portion 16 which extends radially inwardly from a forward end 18 of the tubular portion 14 . There is also a guide portion 20 extending rearwardly from a radially-inner region 22 of the radial portion 16 . Also, there is a starter thread 24 extending radially inwardly from a rearward end 26 of the guide portion 20 .
In one preferred embodiment, the guide portion 20 is tubular. In another preferred embodiment, the guide portion 20 is conical and extends rearwardly and inwardly as seen in FIG. 3 .
Preferably, the tubular portion 14 is conical, preferably at about 86° from horizontal, but the tubular portion 14 may be cylindrical (90° from horizontal).
Preferably, the reinforcing ring 10 is stamped from a metal sheet 42 and in a more preferred embodiment the ring is made of stainless steel.
Preferably, the reinforcing ring 10 is stamped from the steel sheet 42 , preferably a stainless steel sheet.
When the reinforcing ring 10 is stamped in this manner, the starter thread 24 is no more than 360° around the guide portion 20 . In a preferred embodiment, the starter thread 24 is 360° around the guide portion 20 . In another preferred embodiment, the starter thread is less than 360° around the guide portion as seen in FIG. 2 .
As will be seen from the Figures, the reinforcing ring 10 , particularly when stamped from a metal sheet 42 , is dimensioned such that the thickness T of each of the first tubular portion 14 , the radial portion 16 and the guide portion 20 (as best seen in FIG. 3 ) is relatively small or thin compared to the diameter DIA of the first tubular portion 14 as best seen in FIG. 2 . Thus, an appropriate thickness T of metal sheet 42 is selected in order to make the reinforcing ring 10 appropriately dimensioned.
The plastic fitting 12 is intended to and does receive a threaded male part 28 as seen in FIG. 7 . Often the male part 28 is made of metal. The plastic fitting has a plastic body 30 which has inner plastic threads 32 for receiving the male part 28 in threaded engagement.
Preferably the guide portion 20 of the reinforcing ring 10 forms a guide portion 36 of the fitting 12 for guiding the male part 28 to the starter thread 24 . This reduces the likelihood of cross-threading.
Preferably, the starter thread 24 of the reinforcing ring forms a lead face 40 of the first thread 32 A of the threads 32 of the plastic body 30 .
Preferably, when the reinforcing ring 10 is properly installed as part of plastic fitting 12 , the radial portion 16 of the reinforcing ring 10 forms a forward protective portion 38 protecting the plastic body 30 from contact with the male part 28 as the male part 28 initially engages the fitting 12 .
Preferably, the first tubular portion 14 of the reinforcing ring 10 surrounds at least a portion 34 of the plastic body 30 .
Preferably, the plastic fitting 12 is molded with the first tubular portion 14 of the reinforcing ring 10 within and surrounded by a portion 44 the plastic body 30 .
Typically there are several inner threads 32 of the plastic body 30 . There will be at least a first inner thread 32 A (as best seen in FIG. 7 ) closer to the starter thread 24 and a last inner thread 32 B further away from the starter thread 24 . Preferably the tubular portion 14 of the reinforcing ring 10 extends rearwardly to at least the last inner thread 32 B of the plastic body 30 . This will reduce the tendency for shearing the plastic fitting 2 upon over-tightening.
More preferably, the first tubular portion 14 extends rearwardly beyond the last thread 32 B of the plastic body 30 .
It will be understood that, although various features of the invention have been described with respect to one or another of the embodiments of the invention, the various features and embodiments of the invention may be combined or used in conjunction with other features and embodiments of the invention as described and illustrated herein.
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 these 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 herein. | A reinforcing and a plastic fitting incorporating such a reinforcing ring are disclosed. The reinforcing ring and plastic fitting have particular utility with respect to fire sprinkler heads in buildings. The reinforcing ring has a single starter thread which is integrally formed with a guide portion which guides a male part to be axially in line with the female fitting. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to an improved device for ironing cloth articles having different thicknesses.
As is known, for ironing different thickness cloth articles there are conventionally used ironing apparatus which are provided with a bottom ironing panel on which there is coupled a top ironing panel.
For properly locating the cloth article to be ironed on the bottom ironing panel there is used a frame, the so-called pivot, which partially turns or swings about a substantially horizontal axis in order to define an angular path of movement so as to engage the cloth article to be ironed located on the ironing panel and properly hold it in position.
Prior art devices or methods for tensioning the resilient sheet element supported by the pivot by causing the latter to swing, have not been found to operate satisfactorily, since mutual displacements occur during the tensioning operations.
SUMMERY OF THE INVENTION
Accordingly, the aim of the present invention is to overcome the above mentioned drawbacks by providing an improved device for ironing cloth articles having different thicknesses, which allows to easily perfectly locate of the cloth article on the bottom ironing panel or template as well as firmly hold it during the ironing process.
Within the scope of the above mentioned aim, a main object of the present invention is to provide such a device which is adapted to evenly spread the cloth article to be ironed and efficiently affect the ironing process, in combination with the ironing panels or templates and the apparatus therewith it is associated.
Another object of the present invention is to provide such an ironing device which allows to also tension two fabric layer cloth articles, such as, for example, trousers, the tensioning operation being adapted to be performed on both the fabric layers, that is on the bottom fabric layer and on the top fabric layer.
Yet another object of the present invention is to provide such an improved device for ironing different thickness cloth articles which, owing to its constructional features is very reliable and safe in operation.
Yet another object of the present invention is to provide such an improved device for ironing different thickness cloth articles which can be easily applied to already existing ironing machines and which, furthermore is very competitive from a mere economic standpoint.
According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects which will become more apparent hereinafter, are achieved by an improved device for ironing cloth articles having different thicknesses, comprising a bottom ironing panel, thereon a pivot is movably arranged for supporting a resilient sheet element, characterized in that said device further comprises means for causing said pivot to swing about a substantially horizontal axis and driving means for driving said pivot in a direction substantially perpendicular to said ironing panel.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the present invention will become more apparent hereinafter from the following detailed disclosure of a preferred, though not exclusive, embodiment of an improved device for ironing cloth articles having different thicknesses, which is illustrated, by way of an indicative but not limitative example, in the figures of the accompanying drawings, where:
FIG. 1 is a schematic view illustrating the ironing device according to the present invention as applied to an ironing machine;
FIG. 2 is a further schematic view illustrating the bottom ironing panel with means for spreading apart it;
FIG. 3 is a further schematic view illustrating the ironing device in its starting position, with the pivot in a raised condition, in order to allow a cloth article to be ironed to be properly located;
FIG. 4 illustrates the pivot horizontally arranged on the ironing panel;
FIG. 5 illustrates a tensioning step applied to the sheet element of the pivot;
FIG. 6 illustrates a re-rising operation of the pivot, after the ironing process; and
FIG. 7 illustrates an end operating step of opening of the pivot.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the number references of the figures of the accompanying drawings, the improved ironing device for ironing different thickness cloth articles according to the present invention, comprises a bottom ironing panel, indicated generally at the reference number 1, thereon there is arranged, in a per se known manner, a top ironing panel 2.
Between the bottom ironing panel 1 and the top ironing panel 2 there is arranged a resilient sheet element 3, which is supported by a so-called pivot 4, including a frame having a substantially rectangular configuration, projecting from the mentioned bottom ironing panel.
As shown, the pivot 4 is supported by an arm 10 which is articulated,at an intermediate portion thereof, at 11, and which at the free end thereof, is coupled to a swinging cylinder 12, in turn pivoted at 13 to the frame of the ironing machine and which is provided with a stem 14, for swingably driving the pivot.
The arm 10 of the pivot is articulated to the end of a driving or displacement stem 20 of a driving cylinder 21 which allows the pivot to be displaced in parallel to itself.
Moreover, rigid with the stem 20 there is provided a side lug 22 to one end of which there is connected a spring 25 which is also connected to a middle portion of the arm 10.
In this connection it should be pointed out that, in the case in which two-layer cloth articles are to be ironed, such as trousers or the like, the bottom ironing panel will be provided with cloth article spreading means which have been clearly illustrated in FIG. 2, comprising a spreading piston 30 connected to the stem or rod 30', which supports small blocks 31, pivoted to respective end portions of angle levers 32, in turn articulated at a middle, portion 33 thereof and having an actuating arm 34 engaging in elongated slots 35 associated with the half-elements 36 forming the ironing bottom panel 1.
Between the mentioned half-elements 36 there is provided a continuity strip 37 adapted to hold the continuity of the top surface, as the two half-elements are spread apart in order to in turn spread apart a cloth article to be ironed having a fabric double layer.
In actual practice, in the case of single fabric layer cloth articles, such as, for example, skirts, the pivot will operate according to a conventional manner and the fabric will be spread as a single layer by causing the pivot to be properly displaced.
In the case in which a double fabric layer must be ironed, the operation of the pivot will be combined with the spreading of the bottom ironing panel 1.
In operation, at the start the improved ironing device according to the present invention will be arranged at a rest position, as is shown in FIG. 3, and the pivot will be arranged in an opening position, with the stem 20 in a raised position. During this operating step, the cloth article to be ironed will be arranged on the bottom ironing panel 1.
In a second operating step as is shown in FIG. 4, the pivot will be manually brought to a horizontal position and the closing operation will be performed by the spring 25.
Under these conditions, the driving stem 20 will be held at a top end of stroke position, whereas the stem of the rotating cylinder 12 will be withdrawn by the rotary movement of the pivot under these conditions, the cylinder is not power supplied.
Then, in a third operating step, as is shown in FIG. 5, the driving stem 20 will be downwardly driven and a pressure will be applied under the stem 14 in order to cause the pivot 4 to be held in a horizontal position.
During this third operating step the sheet will be spread on the ironing panel, by exerting an elastic or resilient pressure on the bottom ironing panel and, accordingly, on the cloth article arranged thereon.
During this third operating step, the driving cylinder will be supplied with pressurized air, so as to downwardly move, with an adjustable movement amplitude, whereas the rotating cylinder will be supplied at its bottom portion in order to balance the movement of the first cylinder thereby providing a perfectly horizontal position for the pivot.
During a fourth operating step, which is illustrated in FIG. 6, the pivot is returned to its horizontal resting position and a pressurized fluid will be supplied to the driving cylinder to provide a raising movement as well as to the rotating cylinder, which will be supplied at the bottom thereof, so as to hold a horizontal position.
In this operating step, the two driving and rotating cylinders will reach their top end of stroke positions
During the fifth and last operating step, (see FIG. 7), the pivot will be automatically open, under the effect of a pressurized fluid being supplied, in an opposite direction, inside the swinging cylinder, so as to arrive at its opening position, which will be a stable position since the spring 25 will pass the articulation point 11 so as to hold the opening position.
In the case in which a double fabric layer cloth article must be ironed, in addition to the above disclosed operating steps, there is also performed, during the sheet tensioning step, the bottom ironing panel spreading step.
In particular this step is performed by driving the spreading piston 30 which, by swinging the angle arms, will practically cause the ironing panels to be spread apart.
Then, the pivot will be tensioned and the bottom ironing panel will be spread apart, if required.
During the raising movement of the top ironing panel,moisture will be sucked and then will be performed the automatic raising and opening of the pivot, which preceeds the discharging of the ironed cloth article.
From the above disclosure it should be apparent that the invention fully achieves the intended aim and objects.
In particular, the fact is to be pointed out that an improved ironing device has been provided which allows to simply and easily drive the pivot during the tensioning step, thereby providing a perfect tensioning of the cloth article to be ironed.
The invention, as disclosed, is susceptible to several modifications and variations, all of which will come within the scope of the invention.
Moreover, all of the details can be replaced by other technically equivalent elements.
In practicing the invention, the used materials, as well as the contingent size and shapes, can be any, depending on requirements. | An improved device for ironing cloth articles having different thicknesses, comprises a bottom ironing panel thereon there is movably supported a pivot member for supporting a resilient sheet element, and a driving cylinder for causing the pivot member to swing about a horizontal axis and a further driving cylinder for driving the pivot member along a direction substantially perpendicular to the ironing panel. | 3 |
The present invention relates generally to the rapid fabrication of high density carbon-carbon composites or preforms used for friction materials and thermal management systems for automotive and aerospace applications.
BACKGROUND OF THE INVENTION
One way to improve the production efficiency of carbon-carbon composite materials is the development of processes which take advantage of the benefits of pitch matrix precursors. The main advantages of pitch matrices reside in their high carbon content (90% and more), relatively short process steps, as well as specific material properties resulting from their high graphitizability, which provide high thermal conductivity, density and good friction and wear performance.
It is highly desirable to provide rapidly a preform or composite with high density (1.2 g/cm 3 and above) prior to densification by conventional precursor carbon methods: carbon vapor deposition or densification ("CVD") and also called carbon vapor infiltration ("CVI"), pitch or resin and their combinations.
SUMMARY OF THE INVENTION
The present invention provides solutions to the above by providing a method of producing rapidly a carbon-carbon composite made from a green preform comprising carbon fibers and at least one pitch, comprising the steps of:
(a) heating the green preform to a temperature of approximately 450° C., then increasing the temperature at a lesser rate up to approximately 520° C.;
(b) holding at a temperature within the range of approximately 450-520° C. for a period of time;
(c) pressing the preform at approximately 520° C. or higher;
(d) heating the preform to within the range of approximately 520° C.-1,000° C. followed by a soak; and
(e) cooling to provide the composite.
We have disclosed a thermomechanical pressing ("TMP") method for obtaining rapidly a carbon/carbon composite material using any carbon fiber including polyacrylonitrile ("PAN") based carbon fibers and industrial coal-tar or petroleum pitches (including synthetic derivatives) having a melting point m.p.=80-350° C. Generally, a green preform may be prepared from mixtures of chopped carbon fibers and pitch, for example a mixture prepared from 1 part by weight of carbon fibers chopped to the length of Lf=10-50 mm and 1-3 parts by weight of pitch. The resulting mixture is pressed to impart a cylindrical shape to the green preform. The green preform is charged into a metallic mold where it is heated, pressurized, stabilized, and cooled.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in detail below with reference to the drawings in which:
FIG. 1 is a graph of the thermal decomposition of coal tar petroleum pitches and mixtures;
FIG. 2 is a graph of the thermal decomposition of pitches and low temperature carbon fiber mixtures;
FIG. 3 is a graph of the thermal decomposition of pitches and high temperature carbon fiber mixtures; and
FIG. 4 is a graph of the temperature/pressure/time profile used during the TMP process.
DETAILED DESCRIPTION OF THE INVENTION
Among processes for improving the production efficiency of pitch-based carbon-carbon composite materials, we think it expedient, with regard to the requirements for friction materials, to use thermal stabilization methods in combination with a forced mechanical contraction or pressing of the material during pyrolysis. The method developed is referred to as thermomechanical pressing ("TMP").
A pitch matrix and PAN fiber reinforcement were chosen for the TMP process. At present, commercially produced coal tar pitches have softening points Ts=65-75° C. and Ts=135-140° C. and toluene insolubles (α-fraction) content of 20-25 wt. % and 45-54 wt. %, respectively, for medium and high-temperature pitches.
Medium pitches enable the preparation of high-quality "green" bodies with a low coke yield. High-temperature pitches have a higher coke residue of about 55-60%, but their use presents difficulties because at temperatures of 120-280° C. they do not wet carbon substrates thus preventing the use of conventional methods to press "green" bodies.
Therefore, it is of interest to determine if an industrial petroleum pitch with Ts=140° C. can be used in TMP processes. Such pitches have coke residue somewhat lower than a high-temperature coal tar pitch, but considerably higher than a medium pitch and experimental coal tar pitch with Ts-101° C. and α-fraction content of 33.6 wt. %. It was found that the industrial petroleum pitch exhibited better wetting ability compared to high-temperature coal-tar pitches.
In addition, high-temperature petroleum and medium coal-tar pitches were mixed by comelting and the resulting mixtures were studied in an effort to improve wetting characteristics without essential loss in the coke residue yield.
Based on laboratory results, mixtures of high-temperature petroleum and medium coal-tar pitches were prepared by comilling, and the softening temperature of the mixtures of pitches was approximately 100-110° C.
The following pitches and their mixtures were investigated:
1. Pitch grade "A" GOST 10200-83, a medium coal tar pitch, Ts=74° C.
2. An experimental coal tar pitch with elevated softening temperature, Ts=101° C.
3. Pitch grade "I" specs. 14-6-84-72, a high-temperature coal tar pitch, Ts=140° C.
4. Pitch grade "IIHII CB" specs. 48-4807-287-94, a high-temperature petroleum pitch, Ts=140° C.
5. mixture of pitches 1 and 4 in the ratio 0.5:0.5 a laboratory sample
6. mixture of pitches 1 and 4 in the ratio 0.3:0.7 a laboratory sample
7. mixture of pitches 1 and 4 in the ratio 0.45:0.55 an industrial sample
8. mixture of pitches 1 and 3 in the ratio 0.5:0.5 a laboratory sample
The composition and properties of pitches were characterized in terms of the softening point, coke residue yield, and toluene insoluble fraction content. In addition, the molecular weight distribution, thermal decomposition behavior in the temperature range from 200 to 800° C. and the onset wetting temperature of carbon substrate (at a 90 deg. contact angle) were also determined. Pitch characteristics are presented in Table A.
TABLE A__________________________________________________________________________Composition and properties of the pitches. Numbers of pitchesProperty 1 2 3 4 5 6 7 8__________________________________________________________________________Softening point ° C. 74 101 140 140 120 118 110 99(Ring and rod)Coke residual, % 36.3 48.0 60.0 52.6 44.5 47.6 48.0 50.0Fraction of toluene 22.0 33.6 54.0 29.3 25.6 27.1 25.8 38.0insoluble substancesin the, %The onset wetting 105 140 --* 260 205 230 --*temperature, ° C.Thermal analysis:Mass loss, (%)in the rangeup to 360° C. 21.0 9.0 6.5 8.4 14.8 13.0 11.5 12.9360-480° C. 32.6 24.8 23.7 25.4 27.6 28.2 28.8 28.8480-620° C. 5.6 9.7 6.5 8.7 9.3 8.8 9.3 7.5Coke residual 39.4 52.1 63.3 56.0 46.9 46.8 49.6 50.2at 800° C., %Mesophase formation 520 500 510 505 515 510 495 515temperature ° C.Molecular weightdistribution:a) Mw, a.e.m. 327 554 421 551δ) Mn, a.e.m. 234 329 297 359Content of substances 80.0 26.1 28.4 21.8with molecular weightunder 300 a.m.u., %Mw/Mn 1.40 1.58 1.39 1.53__________________________________________________________________________ *No wetting at 120-280° C. is observed.
It is seen from Table A that the petroleum pitch is similar to the coat tar pitch in the α-fraction content, basic temperature ranges of mass loss, molecular weight distribution, and mesophase formation temperature, superior in the coke residue yield and somewhat inferior in the wetting characteristics. The addition of the medium pitch in the amount of 30-50 wt. % to the petroleum pitch improves wetting characteristics but does result in the loss in coke residue. The properties of industrial mixtures of pitches 1 and 4 (coke residue yield, α-fraction content, mesophase transition temperature, thermal decomposition behavior) are similar to laboratory sample mixture 6 and experimental coal tar pitch 2, but are inferior to the latter in wetting characteristics because mechanical stirring on comilling failed to provide the averaging effect in a mixture composition.
At the same time, molecular weight distribution in the petroleum pitch is quite close to that in the experimental coal tar pitch 2, both in the average molecular weight values (Mw and Mn) and low molecular compounds fraction of the total mass. Thermal decomposition behaviors (FIG. 1) and temperature ranges of mesophase transition in these pitches are also close between themselves which allows us to suggest the use of the petroleum pitch per se without medium pitch additions in the TMP process.
In an effort to study the effect of pitch nature on forming the structure and properties of a "primary" matrix in the TMP process, interactions between samples of petroleum and coal tar pitches and their mixtures with carbon fibers heat treated at 1000° C. and VPR-19C carbon fibers heat treated at 2800° C., were investigated. Pitches 2 and 4 and pitch mixtures 5-8 were used for the investigation. Fiber weight fractions in the compositions were 60%. Characteristics of the compositions are presented in Table B.
The caking index, defined as the coke residue gain in a composition (ΔK %) relative to the coke residue yield from the unreinforced pitch, was measured as an indication of the interaction between the fiber and pitch. Mass loss changes in the temperature range from 20 to 800° C. were also determined and compared to those in pure pitches.
As evident from Table B, the highest coke residue gain (see ΔK %) in the presence of carbonized fibers was obtained in the composition containing experimental coal tar pitch 2, whereas the highest coke residue yield (see coke residue %) was reached in the composition based on petroleum pitch 4. Among pitch mixtures, the best results in terms of coke residue yield were obtained in the composition prepared with pitch mixture 6. In the composition containing VPR-19C graphitized carbon fibers and pitch 4, due to the increased mass loss in the temperature ranges up to 360° C. and from 480 to 620° C., the coke residue yield was higher than in the pure pitch but lower than in the composition with carbonized fibers.
It should be noted that the use of coal tar pitch mixture 8 as a matrix in compositions prepared with carbonized fibers provides a lowering of the softening point, a decrease in the α-fraction content, and improved wettability of the pitch but gives no gain in the coke residue compared to the petroleum pitch and its mixtures (Table B, FIG. 2).
In compositions reinforced with the VPR-19C graphitized PAN fiber, the coal tar pitch mixture 8 exhibited higher coke yield and caking index compared to pitch 4 and pitch mixture 7 (see FIG. 3).
These results indicate that the experimental coal tar pitch with increased softening point (pitch 2), petroleum pitch with Ts=140° C. and coke residue yield of at least 56 wt % (pitch 4) and mixtures of the latter with medium coal tar pitch in the ratio of about 60:40 (pitch mixture 7), exhibit attractive properties when mixed with carbonized and graphitized carbon fibers under TMP process conditions. Pitch mixture 8 can be used in compositions with graphitized fibers.
TABLE B______________________________________Properties of pitch-fiber compositions Compositions with pitch samplesProperties 2 4 5 6 7 8______________________________________Carbonized fibers of 17.2 8.0 15.7 12.0 10.8 11.3VPR-19C type, ΔK %Thermal analysis:Mass loss, % in thetemperature range, ° C.up to 360 15.9 9.3 21.6 17.3 17.5 21.3360-480 15.4 19.6 17.7 17.8 18.1 17.4480-620 6.2 6.2 4.0 4.4 8.2 7.4Coke residue at 800° C., % 61.1 62.8 55.1 58.5 54.2 51.4Graphitized fibers of 7.2 11.6 14.7VPR-19C type, ΔK %Thermal analysis:Mass loss, % in thetemperature range, ° C.up to 360 15.4 18.1 20.4360-480 17.1 16.6 13.1480-620 9.3 8.5 5.3Coke residue at 800° C., % 57.3 56.3 59.6______________________________________
The optimum composition of the green preform used in the TMP process requires evaluation of the friction and wear performance of the final product as well as technical and economic considerations.
Previous investigations have indicated that that the highest friction characteristics are offered by high modulus graphitized fibers. However, the use of carbonized fibers is advantageous due to their low cost. Therefore, the following fibers were used as a reinforcing filler for the model friction carbon-carbon composite material:
Type 1. PAN fiber VPR-19C, heat treatment temperature To≅2800° C., the average density, α=1.92 g/cm 3 , fiber length L<0.5 mm
Type 2. PAN fiber VMN-4, heat treatment temperature To≅2000° C., the average density α=1.70 g/cm 3 , fiber length L=30-40 mm.
Type 3. Carbonized PAN fibers, heat treatment temperature To≅1000° C., the average density α=1.77 g/cm 3 , fiber length L=20-30 mm.
All the fibers were derived from PAN fibers. "Green bodies" of the Termar type materials were used for the development of TMP. "Termar" is a tradename for carbon-carbon composite friction material developed by NIIgrafit and produced at the Electrode Plant, both in Moscow, Russia.
Six versions of green bodies were produced from the selected types of fibers and pitches and their mixtures using conventional fabrication methods. The weight ratio of binder (pitch): filler (fiber) for the premix was 0.40:0.60 in case of short cut fibers (Type 1), and 0.5:0.5 in case of long fibers, respectively. To determine the actual carbon fiber:pitch matrix ratio in the green body appeared to be difficult. Sample discs of 126 mm diameter and 25-40 mm thick were cut from full-scale discs of the Termar type material of the dimensions: outer diameter 490 mm, inner diameter 230 mm, thickness 25-40 mm. Eight samples were made from one full-scale disc. The apparent density and volume of the samples were determined via hydrostatic weighing.
The samples were then subjected to a thermomechanical pressing ("TMP"), as described below, in a special metal mandrel fitted with an external electric heating. The mandrel capacity for one charge was 5-6 samples.
The green preform samples were heated at an arbitrary rate (such as 3° C./min.) to approximately 470° C., after which the temperature was increased at a heating rate of 1° C./minute. In order to thermally stabilize the pitch, the preform was held at a stabilization temperature within the range of 450-520° C. for a soak time, for example, of one-half to one hour, to reduce the volatile content and increase the viscosity of the matrix pitch during the application of pressure. The volatiles content of the pitch can determine the soak temperature and time. Thermal stabilization is accomplished at a low pressure (for example, about 1-3 MPa). Upon attaining approximately 520° C., the samples were subjected to a mechanical pressurization within the range of 25-40 MPa (this increased pressurization can be done, for example, in 10-20 minutes). The samples continued to be heated to a temperature of 600±20° C. and maintained at that temperature for a period of time, for example a 1.5-2 hours soak, the specific pressure being 25-37.5 Mpa, in order to remove volatiles and convert the pitch to a solid carbon. The temperature at the soak is envisioned to be within the range of 520-1000° C. Pressure was maintained during the cooling of the samples which was through natural cooling. See FIG. 4 which illustrates the typical temperature, pressure, and time profile for the TMP process.
The samples were removed from the mandrel, and their mass, volume, and apparent density were determined. The mass loss during TMP was calculated as follows:
ΔP=(Pi-Pf)*100%/Pi, (1)
where
Pi is the initial sample mass,
Pf is the final sample mass after TMP,
and the volume shrinkage after TMP was calculated as follows:
ΔV=(Vi-Vf)*100%/Vi, (2)
where
Vi is the initial sample volume,
Vf is the final sample volume after TMP. The results are presented below in Table C
TABLE C__________________________________________________________________________Characterization of various types of composites after TMP. Average Average density of density of VolumeComposition of a material initial sample sample after Mass loss shrinkageTechnological features of TMP dk, g/cm.sup.3 TMP dk, g/cm.sup.3 Δ P, % Δ V, %__________________________________________________________________________Version 1 1.334 ± 0.075 1.44 ± 0.026 15.8 ± 3.8 22.2 ± 4.3Fiber Type 1 + pitch mixture 8P = 25 MPawithout thermal stabilizationVersion 2 1.400 ± 0.051 1.457 ± 0.020 21.3 ± 2.9 24.4 ± 2.5Fiber Type 1 + pitch 2P = 25 MPawithout thermal stabilizationVersion 3 1.434 ± 0.028 1.55 ± 0.025 21.1 ± 3.7 27.0 ± 3.9Fiber Type 1 + pitch 2P = 25 MPawithout thermal stabilizationVersion 4 1.437 ± 0.01 1.638 ± 0.029 17.8 ± 2.4 27.9 ± 1.7Fiber Type 1 + pitch 2P = 37.5 MPawith thermal stabilizationVersion 5 1.391 ± 0.031 1.470 ± 0.019 18.8 ± 7.5 23.2 ± 5.5Fiber type 2 + pitch 2P = 25 MPawith thermal stabilizationVersion 6 1.256 ± 0.09 1.363 ± 0.033 19.6 ± 6.9 26.1 ± 6.4Fiber Type 3 + mixture 7P = 25 MPawith thermal stabilization__________________________________________________________________________
The main purpose of this work was to develop and determine the efficiency of the TMP method, and to consider the affect of various process and material parameters on the TMP process. The experiments conducted have shown that TMP is realizable, i.e., it is practicable to obtain, at an accelerated rate, carbon-carbon composite materials of 1.5-1.65 g/cm 3 density using no modifying additives and with relatively inexpensive equipment. The present invention comprises composites or preforms with a high density of 1.2 gm/cm 3 or greater which can be obtained according to the desired end application. Such preforms can comprise a carbon-carbon composite, with or without graphitization heat treatment, as an end product for desired applications.
Comparison of the versions of combining carbon fibers with matrix pitches, from the viewpoint of obtaining green bodies, has shown that the mixture for versions 2, 3, 4 (fiber type 1+pitch 2) is the most useful composition. The density variation for the green body is within 2-4%.
Furthermore, it should be pointed out that properties of the starting pitch material and the filler used, as noted above, markedly affect the carbon-carbon composite material quality and density after TMP. The best results were obtained using a fine-dispersion filler fiber (Type 1) which has not only a higher density and a larger surface due to grinding, but also a higher specific surface area conditioned by a high heat treatment temperature. These parameters appear to be important for the process of combined (fiber/matrix) caking under TMP.
Comparison of the experimental results have shown that TMP with thermal stabilization of the pitch (versions 3-5) is more efficient than the processes without thermal stabilization predominantly because of the prevention of bloating. As follows from considering the reasons of this phenomenon, the coke yield after TMP with the thermal stabilization exposure is not substantially different as compared to the control processes without thermal stabilization. This is evident from the mass loss index Δ P which indirectly reflects the carbon solid residue. The closeness of the Δ P values for all versions of the investigated compositions and conditions of processing is explained by the fact that the conditions of TMP do not inhibit a free evolution of volatiles under polycondensation and pyrolysis of each pitch type. Thus, the coke yield during TMP depends predominantly on properties of the initial pitch and fibers used.
It is our opinion that the efficiency of the thermal stabilization exposure or soak resides in increasing the viscosity throughout the sample. The viscosity increase during thermochemical transformations makes it possible to decrease the amount of pitch being squeezed out of a sample under pressure, to decrease the composite porosity level, and thus prevent bloating.
Accordingly, the purpose of the TMP process optimization was to find a temperature-time region during or after the pitch thermal stabilization wherein the pressure application would not cause binder to be squeezed out of a preform and would be applied to a material which did not lose its ability to cake. The test results show that the purpose has been best attained for the compositions based on pitch 2 (Versions 3-5).
As regards the pressure effect on the material quality, it was found that the optimal results were obtained when using pressure of about 25 Mpa. The pressure increase in TMP led to the density increase, as seen from Table B (Version 4), however at the same time the number of defects in the final material grew in the form of cracks, delaminations and voids which can be explained by the extreme increase of the fiber content and stresses arising at considerable strains of the high-modulus reinforcing fibrous filler.
The use of TMP for the composition: fiber type 3+ mixture 7 (Version 6) should be considered separately. The behavior of green preforms comprised of petroleum and coal tar pitch mixtures and carbonized fibers employed as the filler made it impossible to obtain high-quality green semiproducts by conventional methods. The green bodies' initial low density (on some samples 0.9-1.0 g/cm 3 ) owing to an insufficient pitch impregnation brought about additional difficulties in the TMP. Because Version 6 includes pitches of different origins, difficulties resulted from the incompatability of the pitches' pyrolysis and thermal stabilization characteristics. This prevented the obtaining of results reflecting the potentialities of Version 6. For Version 6, new approaches are required in order to obtain green bodies and for the optimization of the thermal stabilization conditions during TMP. | A thermomechanical pressing ("TMP") method for obtaining rapidly a high density (1.2 g/cm 3 or higher) carbon/carbon composite preform from any carbon fiber including PAN-based carbon fibers and industrial coal-tar or petroleum pitches (including synthetic derivatives) having a melting point m.p.=80-350° C. Green preforms may be prepared from mixtures of carbon fibers and pitch, and the resulting mixture is formed to impart a cylindrical shape to the green preform. The green preform is charged into a metallic mold where it is heated, stabilized, pressurized for a period of time, and cooled. | 2 |
This application is a divisional of U.S. Ser. No. 10/984,216 filed Nov. 9, 2004, now U.S. Pat. No. 7,217,095 issued on May 15, 2007.
The U.S. Government may have certain rights in this invention in accordance with Contract Number N00019-02-C-3003 awarded by the United States Navy.
BACKGROUND OF THE INVENTION
This invention relates generally to a cooling passage for an airfoil. More particularly, this invention relates to a core assembly for the formation of cooling passages for an airfoil.
A gas turbine engine typically includes a plurality of turbine blades that transform energy from a mainstream of combustion gasses into mechanical energy that rotates and drives a compressor. Each of the turbine blades includes an airfoil section that generates the rotational energy desired to drive the compressor from the flow of main combustion gasses.
The turbine blade assembly is exposed to the hot combustion gasses exhausted from the combustor of the gas turbine engine. The temperature of the combustion gasses exhausted through and over the turbine blade assemblies can decrease the useful life of a turbine blade assembly. It is for this reason that each turbine blade is provided with a plurality of cooling air passages. Cooling air is fed through each of the turbine blades and exhausted out film holes on the surface of the turbine blade. The position of the film holes on the turbine blade creates a layer of cooling air over the surfaces of the turbine blade. The cooling air insulates the turbine blade from the hot combustion gasses. By insulating the turbine blade from exposure to the hot combustion gasses the turbine blade reliability and useful life is greatly extended.
Typically, the cooling passages within a turbine blade are formed by a ceramic core that is provided with and surrounded with molten material that is used to form the turbine blade. Once the molten material utilized to form the turbine blade is solidified the core material is removed. Removing the core material leaves the desired cooling air passages along with the desired configuration of film cooling holes.
As appreciated, each turbine blade assembly represents a dead end or an end of a cooling airflow path. This is so because cooling air flowing from an inner side or platform of the turbine blade flow radially outward to a tip of the turbine blade. The tip of the turbine blade is closed off forming the end of the cooling air passage. Accordingly, the only exit for cooling air through the turbine blade is through the plurality of the film cooling holes disposed about and on the surface of the turbine blade. The configuration and quantity of the film holes for cooling the turbine blade is determined to produce a desired flow rate of cooling air.
The shape of the turbine blade varies throughout the cross section from a leading edge of the turbine blade to a trailing edge. The leading edge is most often much thicker than the trailing edge. However, the cooling needs in the trailing edge are often greater than those in the leading edge and therefore require cooling passages arranged within a close proximity to the trailing edge. As appreciated, cooling passages within the thinner edge section are much smaller. The smaller cooling passages require smaller core assemblies to form those cooling passages. As the size of the core assemblies are reduced the susceptibility to damage during the molding operation increases. The smaller core assemblies required the desired cooling passage in the thinner sections of the turbine blade and are more susceptible to damage during manufacturing.
Accordingly, it is desirable to develop a core assembly that is robust enough to provide for reliable manufacturing process results while still providing for the formation of the smaller cooling air passages in the thinner sections of the turbine blade assembly.
Another concern in the design and configuration of cooling air passages is the direction of cooling air on an inner side of the cooling passage. The cooling passage typically receives air from a main core section. The main core section of the turbine blade is in turn in communication with a cooling air source. The cooling air passage therefore includes an inner surface that is adjacent the main core and an outer surface that is adjacent an exterior surface of the turbine blade. Impingement holes within the cooling air passages communicate air from the main core into the cooling air passage and against the outer surface.
Accordingly, it is desirable to develop a core assembly to form a cooling air passage within a turbine blade assembly that is both reliable during manufacturing processes and that provides the desirable cooling air flow properties to maximize to heat transfer capabilities applications.
SUMMARY OF THE INVENTION
A sample embodiment of this invention includes a turbine blade assembly having cooling passages where each of the impingement holes is isolated from at least some of the other impingement holes. The isolation of the impingement holes within the cooling passages provides for the direction of cooling airflow to specific desired areas. Further, the core assembly utilized for forming the cooling air passages provides a series of structures that strengthen and improve manufacturability.
An example turbine blade assembly of this invention is formed with a cooling air passage that is in communication with a main core. The main core is in turn in communication with cooling air from other systems. The cooling passage is formed through the use of a unique core assembly that includes a plurality of impingement holes that are isolated from each other. Isolating each of the impingement holes from at least some of the other impingement holes prevents cross flow between impingement holes to improve cooling air flow against an outer surface of the cooling passage.
The core assembly provides the configuration of the cooling passages and includes impingement structures for forming the impingement openings. Each of the impingement structures is isolated from at least some of the other impingement structures by separation structures. The separation structures form the channels within the cooling passages that isolate the impingement openings. Each of the channels formed by the core assembly is in communication with expanded chambers at a side of the cooling passage. Within the expanded chamber are film structures that are provided for creating the film openings between the cooling air passage and an exterior surface of the turbine blade assembly.
Accordingly, the turbine blade assembly of this invention includes cooling air passages that provide desirable cooling characteristics for the turbine blade.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a side view of a turbine blade assembly according to this invention.
FIG. 1B is a cross-section view of a portion of the turbine blade assembly.
FIG. 2 is a prospective view of an airfoil assembly.
FIG. 3 is a prospective view of a portion of a core assembly according to this invention.
FIG. 4 is a prospective view of an airfoil assembly according to this invention with a portion broken away to illustrate the cooling air passage.
FIG. 5 is a prospective view of a core assembly according to this invention.
FIG. 6 is a view of an exterior surface of a cooling passage.
FIG. 7 is a plan view of a side of a core assembly according to this invention.
FIG. 8 is a plan view of the other side of a core assembly as shown in FIG. 7 .
FIG. 9 is a view of one side of a core assembly according to this invention.
FIG. 10 is a view of an opposite side of a core assembly illustrated in FIG. 9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1A and 1B , turbine blade assembly 10 includes an airfoil section 12 , a root section 14 , and a platform section 16 . The root section 14 extends into a hub portion (not shown) as is known in the art. The root section 14 extends to the platform section 16 . The airfoil 12 extends upwardly from the platform section 16 . Turbine airfoil section 12 extends from the platform section 16 to a tip 18 . The turbine blade assembly 10 includes a leading edge 20 and a trailing edge 22 . Between the leading edge 20 and the trailing edge 22 is the exterior surface 24 . The exterior surface 24 is shaped to provide the desired transition or conversion of gas stream flow to rotational mechanical energy. As should be understood, the turbine blade assembly 10 as is shown in FIG. 1A is as is known to a worker skilled in the art. A worker skilled in the art with the benefit of this disclosure would understand that other airfoil configurations utilized in different applications would benefit from the disclosures and cooling passages of this invention.
The turbine blade assembly 10 includes a cooling passage 30 . The cooling passage 30 is disposed within the turbine blade assembly 10 . Cooling air enters the turbine blade assembly 10 through passages 26 within the root section 14 . Cooling air enters through the passages 26 into a main core 28 ( FIG. 1B ). Main core 28 is a hollow portion within the interior of the turbine blade assembly 10 . Cooling air communicated through the passages 26 and into the main core 28 enters cooling passages 30 disposed within the turbine blade assembly 10 . Cooling air enters the cooling passages 30 from the main core 28 through a plurality of impingement openings 32 .
Cooling airflow from the impingement openings 32 flows toward expansion chambers 42 disposed opposite the impingement opening 32 . Cooling airflow then proceeds through the walls of the turbine blade assembly 10 through film openings 34 . Cooling air exiting the cooling passage 30 through the film openings 34 flows over the exterior surface 24 of the turbine blade assembly 10 to provide a cooling and insulating layer of air.
The turbine blade assembly 10 of this invention includes the cooling passage 30 . Each of the cooling passages 30 includes the impingement openings 32 . The impingement openings 32 are isolated from each other by channels 36 . The channels 36 are formed by a series of separating structures 38 . Separation and isolation of each of the impingement openings 32 provides for the separation of cooling flow that is impinged upon an outer surface of the cooling passage 30 . Further, isolation of adjacent impingement openings 32 prevents and reduces cross flow problems encountered with typical conventional prior art impingement opening designs. The flow from the impingement openings 32 passes through the channel 36 to the plurality of film holes 34 . Film holes 34 are in communication with the expanded chamber 42 . The expanded chamber 42 provides a portion of the cooling passage for the accumulation of cooling air that is to be communicated to the film openings 34 . The accumulation of cooling air within the expanded chamber 42 reduces problems associated with back wall strikes corresponding with impingement openings 32 .
Referring to FIG. 2 , a prospective view of the airfoil 12 is shown to illustrate the configuration of the main core 28 . The main core 28 provides for communication of cooling air up through the central portion of the turbine blade assembly 10 and to communicate with cooling passages 30 . The specific shape and configuration of the turbine blade assembly and the airfoil 12 illustrated in FIG. 2 is as known. A worker with the benefit of the disclosure would understand that many different types of airfoil configurations will benefit from this the cooling passage configuration illustrated and described within this disclosure.
Referring to FIG. 3 , the cooling passage 30 is formed within the turbine blade assembly 10 through the use of core assembly 44 . The core assembly 44 provides for the formation of the various structures and configuration including openings, channels of the cooling passage during fabrication of the turbine blade assembly 10 . Conventionally, the turbine blade assembly 10 is fabricated through the use of a conventional molding process. The core assembly 44 can be fabricated from known core materials such as specially formulated ceramic and refractory metals. The core assembly 44 is placed within a mold and then surrounded by molten material that will comprise the turbine blade assembly 10 . Upon solidification of the material forming the turbine blade assembly 10 , the core assembly 44 is removed. Removal of the core assembly 44 is as known and can comprise various processes including leeching or oxidation process where a chemical are used to destroy and leech out the core assembly 44 . As appreciated, a worker versed in the art with the benefit of this disclosure would understand that the use of other molding process and materials as are known are within the contemplation and scope of this invention. The type of removal process that is utilized to remove the core 44 from the turbine blade assembly 10 will depend on various factors. These factors include the type of turbine blade material, the type of core material used and the specific configuration of the cooling air passage.
The core assembly 44 utilized to form intricate cooling air passages required to provide the desired cooling properties within the turbine blade assembly 10 . The core assembly 44 includes impingement structures 46 that extend and provide formation of the impingement openings 32 within a completed turbine assembly 10 . Core assembly 44 also includes separation structures 48 that form the channels and walls that are required for isolating each of the impingement openings 32 from at least another of the impingement openings 32 .
Referring to FIG. 4 , an airfoil 12 is shown with a portion of the surface removed to illustrate the specific features of the cooling air passage formed therein. The cooling air passage 30 includes the expanded chambers 42 on each side of the cooling air passage 30 . The cooling air passage 30 includes a lead edge side 50 and a trailing edge side 52 . Each side of the cooling air passage 30 includes an expansion chamber 42 . Adjacent impingement openings 32 communicate with an expansion chamber 42 disposed on an opposite side of the cooling air passage 30 . No two adjacent impingement openings communicate cooling air to a common expansion chamber 42 . In this way the specific cooling flow can be controlled and tailored to provide cooling to specific areas and features of the airfoil 12 .
Referring to FIG. 5 , an example core assembly 44 is shown and includes the impingement structures 46 utilized to form the impingement openings 32 within the airfoil 12 . The impingement openings 32 communicate cooling air from the main core 28 into the cooling passage 30 . The core assembly 44 also includes the separation structures 48 that utilize and provide for the separation of cooling air through each adjacent impingement opening 32 . The core assembly 44 includes a reverse structure from that which will be formed within the completed turbine blade airfoil 12 . The impingement structures 46 therefore are extensions that will extend through and provide the openings through the airfoil 12 to the main core 28 . The structure and space of the core assembly 44 provides for the open spaces within the completed airfoil 12 .
The core assembly 44 also includes a plurality of heat transfer enhancement features 60 . These heat transfer enhancement features 60 are formed in the core assembly 44 as openings such that within the completed cooling air passage 30 the heat transfer enhancement features 60 will form a plurality of ridges that extend upward within the various of the cooling air passage 30 . A worker with the benefit of this disclosure would understand that different shapes of the heat transfer enhancement features 60 other than the examples illustrated that disrupt or direct airflow are within the contemplation of this invention.
Referring to FIG. 6 , an outer side 56 is illustrated. The outer side 56 is cut away from the airfoil 12 illustrated in FIG. 4 . The outer side 56 is not typically sectioned as is shown in FIG. 6 but is an integral portion of the airfoil 12 . The outer side 56 is adjacent the exterior surface of the airfoil 12 . FIG. 4 illustrates an inner side 54 of the cooling passage 30 . The inner side is adjacent the main core 28 . It is for this reason that the ridges 62 are provided on the outer side 56 illustrated in FIG. 6 . As appreciated, thermal energy radiates along the exterior surface 24 .
The outer side 56 that is adjacent the exterior portion of the airfoil 12 is provided on which cooling air flow can most affect desired heat absorption and transfer. Airflow through the impingement openings 32 strikes the outer sides 56 immediately across from the impingement openings 32 . Airflow will then proceed as directed by the channels 36 towards the trailing edge or leading edge side towards the expansion chamber 42 . Through the channels 36 air will be controlled and tailored to create turbulent effects that increase heat transfer and absorption properties. Once air has reached the expansion chambers 42 it is accumulated and exhausted out the film holes 34 . Through the film holes 34 the air will then be exhausted into the main combustion gas stream. The example core assembly 44 is substantially straight. However, the core assembly 44 may include a curved shape to conform to an application specific airfoil shape.
Referring to FIG. 7 , a portion of the core assembly 44 is shown that provides for the formation of the outer side 56 of the cooling air passage 30 . The core assembly 44 includes the structures that form the channels 36 , film holes 34 , and separating structures 38 . The impingement structures 46 are illustrated in dashed lines to indicate that they do not extend outwardly from this side of the core 44 . Instead the impingement openings are formed from extensions or structures 46 that extend from an opposite side of the core. This side of the core assembly 44 produces these features within the outer side 56 of the cooling air passage 30 of the completed airfoil 12 . In this example core assembly 44 , each impingement structure 46 it opens into a separate channel 36 . Therefore each of the impingement openings 32 are isolated from any of the adjacent the impingement openings 32 . Within each of the channels are a plurality of the heat transfer enhancement structures 60 that will form the desired ridges and heat transfer ridges 62 within the completed channels 36 . The heat transfer structures 60 illustrated in FIG. 7 are cavities that receive material during the molding process to form the outwardly extended ridges.
Referring to FIG. 8 , an inner side of the core assembly 44 is shown and includes the impingement structures 46 . The separation structures 48 are shown in dashed lines to indicate that they would not extend from this side but would extend from the opposite side. Further, the other structures that would be formed on the outer side 56 from the inner side 54 are not shown for clarity purposes. However, as appreciated those features would extend outwardly from the opposite side and may also be represented by dashed lines in this view.
Referring to FIGS. 9 and 10 , another example core assembly 70 according to this invention, includes a plurality of impingement structures 46 disposed within separate channels 36 . In this core assembly 70 , three impingement structures 46 are disposed within each of the separation channel 36 . By providing several impingement openings within each chamber the specific air flow requirements and cooling airflow impingement on a specific area can be tailored to accommodate area specific heat transfer and absorption requirements. Although there are several impingement openings 46 disposed within each channel 36 . These are still isolated from at least one impingement opening is isolated from at least another impingement opening. Further, the impingement openings are all disposed about a centerline 40 .
Although each of the impingement openings 32 are disposed about a common centerline 40 they are still isolated from at least one other impingement opening. Although it is shown in the example core assembly 70 that the impingement openings and impingement structures 46 are disposed about a centerline 40 , other configurations and locations of impingement openings are within the contemplation of this invention. A worker versed in the art will understand that isolation of at least one impingement opening relative to another impingement opening provides the desired benefits of tailoring cooling in a cooling passage.
Referring to FIG. 10 , the core assembly 70 is shown on the side opposite that shown in FIG. 9 and illustrates the side of the core assembly 70 that would form the outer side 56 of the cooling air passage 30 . This side of the core assembly 70 illustrates the film structures 58 that would form the film holes 34 in the completed airfoil 12 . Further, heat transfer structures 60 are illustrated that would form the heat transfer ridges 62 (best shown in FIG. 6 ) in the completed cooling passage 30 . Further, as is shown, the impingement structures 46 are shown in dashed lines indicate their location relative to the features formed on the outer side 56 . As can be seen by FIG. 10 the separation structures 48 and the heat transfer structures 60 provide for the creation of a tailored cooling airflow from the impingement openings to the film openings.
Accordingly, the core assembly 44 and airfoil 12 of this invention provides for the tailoring and improvement of cooling air properties within a turbine blade assembly 10 . Further, the core assembly 44 includes a single core that can provide a plurality of individual channels desirable for separating airflow through each of the impingement hole openings. The isolation of the impingement openings provides improved airflow and tailoring capabilities for implementing and optimizing local cooling and flow characteristics within an airfoil.
Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention. | A turbine blade airfoil assembly includes a cooling air passage. The cooling air passage includes a plurality of impingement openings that are isolated from at least one adjacent impingement opening. The cooling air passage is formed and cast within a turbine blade assembly through the use of a single core. The single core forms the features required to fabricate the various separate and isolated impingement openings. The isolation and combination of impingement openings provide for the augmentation of convection and film cooling and provide the flexibility to tailor airflow on an airfoil to optimize thermal performance of an airfoil. | 8 |
BACKGROUND OF THE INVENTION AND RELATED ART
The present invention relates to a device for gripping and pulling a length of thermoplastic sheet softened to be moldingly formed at the front and rear edges. The edges which are otherwise inevitably made to be concave are held substantially straight.
Various articles such as bath tubs, refrigerator compartments and the like are formed by feeding a thermally softened plastic sheet having of a width and length necessary for forming the desired article between a pair of opposite dies separated with each other. Forming occurs by holding the opposite side edges thereof by means of a pair of endlessly driven cramp chains, and then engaging said upper and lower dies together.
The plastic sheet is in general continuously formed by a extruder having a slit nozzle of a desired gap and width, and cut in the necessary length. In either case where the cut sheets are directly fed from the extruder to a forming machine having dies or where the cut sheets once stored are successively supplied thereto e.g. from a pallet, they must be heated to be relevantly formed just in front of said dies.
The softened plastic sheet, which is seized by the pair of cramp chains at and along the opposite side edges to be fed to the forming machine, is inevitably dangled down in the longitudinal direction due to thermoplasticity and weight or gravity thereof, and shrinks more or less in the length thereof due to cooling during feed so that the originally straight front and rear edges of the sheet are made concave, which is more definitely illustrated later.
Not only does such dangling of the plastic sheet have adverse affects on relevant molding of the articles, but also such shrinkage in the lengthwise direction necessitates that the plastic sheet is cut longer so as to compensate for shrinkage, which results in material loss.
It is not always simple to grip the concave front and rear edges of the plastic sheet so as to suitably pull the edges to be substantially straight in the forming machine without disturbing the forming operation.
In JP-A Sho No. 62(1987)-161523, there is disclosed a device for gripping and pulling the concave front and rear edges of the softened plastic sheet comprising a pair of upper and lower clamp members adapted to move vertically apart for allowing the plastic sheet to be brought between the upper and lower dies and towards each other for holding the sheet at the rear edge therebetween with each other. Another pair of upper and lower clamp members are adapted to move vertically apart for allowing the article formed on the plastic sheet to be discharged out of the forming machine and towards each other for holding the sheet at the front edge therebetween with each other. Each of the two pairs of clamp members being mounted on a respective carriage adapted to longitudinally move for pulling the clamped edges rearwardly and forwardly.
This is not satisfactory, however, in that there must be provided two carriages to be longitudinally moved for pulling the softened plastic sheet in opposite directions in addition to the vertically movable clamp members, and independent therefrom so that it is difficult to actuate pulling timingly and with suitable force relative to clamping.
SUMMARY OF THE INVENTION
It is, thus, an object of the invention to provide a device of the art which can avoid and overcome said defects of the related known device.
Another object of the invention is to provide such device which is more compact and inexpensive.
Other objects and advantages thereof will be appreciated by those skilled in the art by carefully studying a description on the preferred embodiment of the invention to be given hereafter in reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section of a forming machine in which the gripping device according to the invention is arranged, shown in the waiting position for receiving a plastic sheet from a heating zone,
FIG. 2 is a similar view of the gripping device together with the forming machine in the operating position,
FIG. 3 is a side elevation of a pair of upper and lower gripping members of the device according to the invention partly in section in a larger scale in the waiting position,
FIG. 4 is a similar view but in the first phase operating position,
FIG. 5 is a similar view but in the second phase operating position,
FIG. 6 is a perspective view of the lower one of the pair of gripping members,
FIG. 7 is a plan view of the thermally softened plastic sheet and two pairs of upper front and rear gripping members in the respective waiting positions,
FIG. 8 is a similar view but showing the gripping members in the respective operating positions so that the concave front and rear edges of the plastic sheet shown in FIG. 7 are held and pulled thereby to be substantially straight,
FIGS. 9 and 10 are similar views showing status of plastic sheets supplied, thermally softened and fed to the forming machine in case where the device of the invention is not used.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Firstly in reference to FIG. 9, a plurality of thermoplastic sheets (S) each cut in a length (L) is successively supplied e.g. from a pallet, not shown, so as to be held by a pair of endless clamp chains (C) at the opposite side edges thereof and carried thereby through a first preheating zone (H1) and a second heating zone (H2) to be moldingly formed in a forming zone (F). The straightly severed front and rear edges of the plastic sheet (S) are made to be concave in the preheating zone (H1) due to dangling and the concaveness is increased in the second heating zone (H2). Due to cool shrinkage of the length of the heated sheet which is held by the pair of clamp chains (C) along the side edges, this concaveness is further increased when the sheet is brought in the forming zone (F) so that the effective length thereof is reduced to (La), if there is taken no countermeasure.
The similar situation is caused also in case where a plurality of plastic sheets (S) are formed and cut by an extruder (E) having a cutter (EC) to be directly fed to the forming zone (F) through the heating zone (H).
Now in reference to FIGS. 1 and 2, the plastic sheets (S) respectively cut in the length (L) are intermittently supplied by the pair of so driven endless cramp chains (C) from the heating zone to the forming zone (F), where an upper die (UD) and a lower die (LD) are separated with each other for the purpose of allowing the plastic sheet (S) to be in position therebetween as shown in FIG. 1 and then engaged together for molding as shown in FIG. 2.
Before molding, the softened and consequently dangled plastic sheet (S) must be gripped by at least two pairs of lower and upper gripping members 20, 20; 30, 30 of the device according to the invention respectively at the front and rear edges so as to be pulled respectively forwards and rearwards so as to be moldingly formed in a desired article (A). As shown in FIG. 2, the molded article is then discharged out of the forming zone (F) when the pair of dies (UD, LD) as well as the pairs of upper and lower gripping members (20, 30) are separated respectively with each other.
For that purpose, the lower die (LD) is adapted to move up and down e.g. by a piston-cylinder device which is not exclusively but preferably mounted on a bottom wall 11 of a vertically movable casing 10, which itself is adapted to move up and down e.g. by another piston-cylinder member. The lower front and rear gripping members 20, 20 are not exclusively but preferably mounted on each of the tops of the front and rear end walls 12, 12 of the casing 10 to face oppositely to the respective counterpart upper front and rear gripping members 30, 30 which are preferably mechanically connected with the lower members 20, 20 so as to be moved up and down in a synchronized manner.
Thus, when another piston-cylinder means is actuated to raise the casing 10, the lower and upper gripping members 20, 30 are engaged with each other so that the plastic sheet (S) is grippingly held thereby at the front and rear edges and concurrently pulled respectively forwards and rearwards according to the invention to be explained in detail hereafter. Then, the lower die (LD) is moved up by actuating said first piston-cylinder means relative to the raised casing 10 to engage with the upper die (UD) synchronistically lowered for molding, which itself is out of the scope of the invention.
In FIGS. 3, 4 and 5, the lower and upper rearward gripping members 20, 30 are illustrated respectively in the waiting, first phase operating and second phase operating positions, which are just same in the construction by symmetrical in arrangement with another pair of gripping members for the front edge of the plastic sheet.
The lower member represented generally by 20 comprises a gripping tip 21 formed on a body portion 22 which is mounted on said casing rear end wall 12 in this embodiment. A pull lever 23 longitudinally extends so that the free end thereof may lie just below the rear edge of the plastic sheet (S) brought in position in the forming zone (F). A pivot lever 24 is pivotally connected 24' at one end with the other end of the pull lever 23. A sleeve 25 through which the pivot lever 24 may slidingly move at the other end portion and which is pivotally mounted on a stud 22' provided on the body portion 22 remote from said gripping tip 21. A pair of longer and shorter parallel link arms 26A, 26B are each pivoted 26A', 26B' at one end with the pull lever 23.
Said link arms 26A, 26B are pivotally mounted 26A", 26B" on the body portion wall 22 respectively at the middle of the former and at the other end of the latter. The other end of the link arm 26A normally abuts on a stopper pin 27 planted on the body portion wall 22 as shown in FIG. 3. A coiled spring 28 is mounted on and along the pivot lever 24 for urging the pull lever 23 pivotally connected therewith so that the free end of said lever 23 is normally exposed beyond the gripping tip 21 to lie below the rear edge of the sheet (S) and the link arm 26A abuts on the pin 27 as referred to above.
As seen from the perspective view of the lower gripping member (FIG. 6), it is preferable to provide a pair of longer link arms 26A and a pair of shorter link arms 26B respectively pivotally mounted on the pull lever 23 and the body portion wall 22 at the both sides thereof for stable movement
The upper rear gripping member represented generally by 30, which is substantially the same in construction but symmetrical in arrangement with the lower rear gripping member as referred to above, comprises a gripping tip 31 formed or attached on a body portion 32 which is mechanically connected with the casing 10 so as to be synchronistically lowered when the casing is raised. A pull lever 33 longitudinally extends so that the free end thereof may lie just above the rear edge of the plastic sheet (S) brought in position in the forming zone (F). A pivot lever 34 pivotally connected 34' with the pull lever 33. A sleeve 35 is provided through which the lever 34 is slidingly movable at the other end portion. A pair of longer and shorter parallel link arms 36A, 36B are similarly pivoted 36A', 36B' on the pull lever 33 and pivoted 36A", 36B" on the body portion wall 32. A stopper pin 37 is planted on the wall 32 to normally abut on the free end portion of the link arm 36A. A coiled spring 38 is similarly mounted on and along the pivot lever 33.
The pull levers 33, 23 are formed at the faced sides thereof respectively with a recess 39 and a correspondingly arranged protrusion 29 having a length is a little longer than the depth of said recess 39 so that even when said two levers are engaged with the protrusion fitting in the recess there is left therebetween a gap only a little smaller than the thickness of the sheet (S).
Both gripping members 20 and 30 are arranged and mounted in such a way that the pull levers 23 and 33 are separated with each other for receiving the plastic sheet (S) at the rear edge therebetween and exposed at the free end portion out of an opening formed between the opposite gripping tips 21 and 31.
When the lower gripping member 20 is raised e.g. by actuating another piston cylinder means to raise the casing 10, the upper gripping member 30 is lowered in a synchronized manner as shown by arrows in FIG. 3 respectively against the force of the coiled springs 28, 38 so that the pull levers 23, 33 are engaged together by fitting of the protrusion 29 into the recess 39 to seize the edge of the plastic sheet (S) therebetween at the free end portions. This is shown in phantom lines in FIG. 4.
Further vertical movement of the upper and lower gripping members towards each other compels the parallel link levers 26A, 26B; 36A, 36B to angularly move respectively on the pivots 26A", 26B"; 36A", 36B". This in turn retracts the pull levers 23, 33 engaged together against the force of the coiled springs 28, 38 to be in the respective positions shown by solid lines in FIG. 4 so as to pull the concerned edge of the sheet into the engaged members 20, 30.
Further vertical movement of the upper and lower gripping members towards each other brings engagement of the opposite gripping tips 21, 31 with biting the plastic sheet edge therebetween for ensuring a hold thereof as shown in FIG. 5.
When the article (A) has been moldingly formed, the both dies (LD), (UD) and the at least two pairs of gripping members 20, 30 are vertically moved apart from each other, the gripping tips 21, 31 are separated with each other thereby. The pull levers 23, 33 are separated with each other by means of the springs 28, 38 so as to release the plastic sheet (S) which can be not exhausted out of the forming zone (F).
As readily appreciated by glancing at FIGS. 7 and 8, it is preferable to use the device having four pairs of lower and upper gripping members 20, 30, the two pairs of which are for gripping and pulling the front concave edge while the other two pairs are for gripping and pulling the rear concave edge. | A device for gripping and pulling a length of thermoplastic sheet softened to be moldingly formed at the front and rear edges, which are otherwise inevitably made to be concave, so as to hold edges substantially straight. The device uses at least two pairs of lower and upper gripping members arranged to be vertically movable so as to grip the above front and rear edges. Two pairs of pull levers each cooperating with one of the pair of lower and upper gripping members operate so as to grip the front and rear edges in advance of the gripping by the gripping members and pull to straighten the concaved edges which are then gripped by the gripping members. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to protecting motorcycles from damage during transport in trucks or trailers.
BACKGROUND OF THE INVENTION
[0002] Motorcycle(s) are often transported in trucks or trailers and are frequently damaged when road conditions or abrupt driving actions cause the motorcycles to move and come into contact with each other or the structure or other contents of the trucks or trailers.
[0003] The existing practice to attempt to prevent such damage during transport is to secure each motorcycle to the truck or trailer in an upright position by strapping the front handlebars to anchor points on the floor of the truck or trailer. When the straps are tightened, the front suspension of the motorcycle compresses and the applied force holds the motorcycle in an upright position. The front wheel is also typically held in place on the floor by a wheel chock or clamp. Because there is no compression point in the rear of a typical motorcycle, the rear is either left untethered or tied to the truck bed or trailer to keep it in line with the front tire and restrict lateral movement.
[0004] This existing practice often fails to prevent damage to motorcycles due to faulty installation or road conditions or driving actions resulting in forces that compromise the straps, attachments, and clamps, or movement of other contents in the trucks or trailers.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention is an inflatable and nonabrasive bumper having the shape, dimensions, strength, and flexibility when secured to motorcycle(s) and inflated to create forces necessary to stabilize the motorcycle(s) during transport and prevent the motorcycle(s) from moving and coming into contact with other motorcycle(s) or the structure or other contents of the truck bed or trailer.
[0006] This invention can be used on its own or as a secondary or backup protective measure in conjunction with the existing practice described above of strapping the motorcycle(s) to anchor points on the truck or trailer.
[0007] This invention protects motorcycles from damage during transport to a further degree and extent than any product or method known in the prior art.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0008] FIGS. 1A-E show the method of loading, positioning, securing, and protecting two motorcycles in a trailer with inflatable bumpers according to one possible embodiment of the invention;
[0009] FIG. 2 is an overhead view of two motorcycles positioned, secured, and protected with inflatable bumpers in a trailer according to one possible embodiment of the invention;
[0010] FIG. 3 is an overhead view of one motorcycle positioned, secured, and protected with inflatable bumpers in a trailer according to one possible embodiment of the invention;
[0011] FIG. 4 is a perspective view of one motorcycle positioned, secured, and protected with inflatable bumpers in a trailer according to one possible embodiment of the invention;
[0012] FIG. 5 is an enlarged perspective view of the inflated bumper of one possible embodiment of the invention;
[0013] FIG. 6 is an enlarged overhead view of the inflated bumper of one possible embodiment of the invention;
[0014] FIG. 7 is an enlarged side view of the inflated bumper of one possible embodiment of the invention in a partially deflated state;
[0015] FIG. 8 is an enlarged perspective view of the deflated bumper of one possible embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] There are many possible embodiments of the invention, some of which are described below.
[0017] Referring now to the embodiments of the invention in FIGS. 1-8 , in more detail, there is shown inflated bumper(s) 10 , harness loop(s) 10 a , harness strap(s) 10 b , air valve(s) 10 c , motorcycle(s) 11 , front suspension(s) 11 a , front strap(s) 12 , rear strap(s) 13 , anchor points(s) 14 , truck/trailer floor 15 , truck/trailer vertical wall(s) 16 .
[0018] In further detail, referring to FIG. 1A-E , three inflated bumpers 10 are positioned and apply force on either side and in between two motorcycles 11 and the opposing truck/trailer vertical walls 16 to stabilize the two motorcycles in an upright position. The inflated bumpers 10 are nonabrasive and flexible to the contours of the motorcycles 11 and secured to the motorcycles by harness straps 10 b and harness loops 10 a . The typical manner known in the art in which motorcycles have been secured for transport prior to this invention is shown by the front strap 12 compressing the motorcycle front suspension 11 a through tension to the anchor points 14 .
[0019] In further detail, referring to FIG. 2 , three inflated bumpers 10 apply force on either side and in between two motorcycles 11 and the opposing truck/trailer vertical walls 16 to stabilize the two motorcycles 11 in an upright position. The inflated bumpers 10 are nonabrasive and flexible to the contours of the motorcycles 11 and secured to the motorcycles by harness straps 10 b and harness loops 10 a . The typical manner known in the art in which motorcycles have been secured for transport prior to this invention is shown by the front strap 12 compressing the motorcycle front suspension 11 a through tension to the anchor points 14 .
[0020] In further detail, referring to FIG. 3 , two inflated bumpers 10 inflated through air valves 10 c apply air pressure force on either side of a motorcycle 11 and the opposing truck/trailer vertical walls 16 to stabilize the motorcycle 11 in an upright position. The inflated bumpers 10 are nonabrasive and flexible to the contours of the motorcycle 11 and are secured to the motorcycle by harness straps 10 b and harness loops 10 a . The typical manner known in the art in which motorcycles have been secured for transport prior to this invention is shown by the front strap 12 compressing the motorcycle front suspension 11 a through tension to the anchor points 14 , and the rear straps 13 holding the rear of the motorcycle 11 from lateral movement.
[0021] In further detail, referring to FIG. 4 , two inflated bumpers 10 inflated through air valves 10 c apply air pressure force on either side of a motorcycle 11 and the opposing truck/trailer vertical walls 16 to stabilize the motorcycle 11 in an upright position. The inflated bumpers 10 are nonabrasive and flexible to the contours of the motorcycle 11 and are secured to the motorcycle by harness straps 10 b and harness loops 10 a . The typical manner known in the art in which motorcycles have been secured for transport prior to this invention is shown by the front strap 12 compressing the motorcycle front suspension 11 a through tension to the anchor points 14 , and the rear straps 13 holding the rear of the motorcycle 11 from lateral movement.
[0022] In further detail, referring to FIGS. 5 , 6 , 7 , and 8 , respectively, there is shown enlarged top, front, and side perspectives of the the inflated bumper 10 , harness loop 10 a , harness strap 10 b , and air valve 10 c.
[0023] In one embodiment of the invention, the inflatable bumper 10 is constructed of rubber.
[0024] In one embodiment of the invention, the inflatable bumper 10 is constructed of plastic.
[0025] In one embodiment of the invention, the inflatable bumper 10 is constructed of kevlar.
[0026] In one embodiment of the invention, the inflatable bumper 10 is constructed of a composite material.
[0027] In one embodiment of the invention, the inflatable bumper 10 has an outer surface layer that will not scratch the paint or chrome on the motorcycle 11 .
[0028] In one embodiment of the invention, the inflatable bumper 10 has an outer surface layer of fabric.
[0029] In one embodiment of the invention, the inflatable bumper 10 is constructed of a material resistant to ultra-violet rays.
[0030] In one embodiment of the invention, the inflatable bumper 10 is constructed of a material resistant to chemical agents.
[0031] In one embodiment of the invention, the inflatable bumper 10 has seam welds of at least an inch overlap.
[0032] In one embodiment of the invention, the inflatable bumper 10 remains inflated with at least one ton of dead weight applied.
[0033] In one embodiment of the invention, the valve 10 c is a presta valve.
[0034] In one embodiment of the invention, the valve 10 c is a schrader valve.
[0035] In one embodiment of the invention, the valve 10 c is a combination schrader and presta valve.
[0036] In one embodiment of the invention, the shape and dimensions of the fully inflated inflatable bumper 10 are calculated and custom fit to fill the void of space created by a given model of motorcycle when positioned in a given truck or trailer.
[0037] In one embodiment of the invention, the dimensions of the inflatable bumper 10 are approximately twenty inches long by ten inches high by twenty-four inches wide when fully inflated.
[0038] In one embodiment of the invention, a process and method for securing motorcycle(s) 11 is to place into position and inflate the inflatable bumper 10 after motorcycle(s) 11 are secured for transport in the typical manner by the front strap 12 compressing the motorcycle front suspension 11 a through tension to the anchor points 14 , and the rear straps 13 holding the rear of the motorcycle 11 from lateral movement.
[0039] In one embodiment of the invention, a process and method for releasing motorcycle(s) 11 is to first partially deflate the inflatable bumper 10 by opening the valve 10 c and second release the harness strap(s) 10 b and any other straps securing the motorcycle(s) 11 .
[0040] In one embodiment of the invention, the inflatable bumper 10 may be deflated and compactly stored.
[0041] The advantages of the present invention include, without limitation, unprecedented protection of motorcycles from damage during transport, a method and process that is simple and requires only a few minutes, and convenience of deflating the inflatable bumper for easy storage.
[0042] While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of these specific embodiments. The invention should therefore not be limited by the above described embodiments, but shall include all embodiments within the scope and spirit of the invention. | Inflatable bumper system that stabilizes and protects one or more motorcycles during transport by applying force on both sides of each motorcycle and the walls of the truck or trailer, securing each motorcycle in an upright position, and absorbing any forces resulting from poor road conditions or abrupt driving actions. | 1 |
This is a continuation of application Ser. No. 08/139,001, filed Oct. 21, 1993, now U.S. Pat. No. 5,397,064.
BACKGROUND OF THE INVENTION
The present invention relates to a pulsating fluid spray device or shower head of the general type disclosed in U.S. Pat. No. 3,473,736, No. 3,568,716 and No. 4,101,075 which issued to applicant. The shower heads disclosed in these patents provide for pulsating the water stream discharge from the shower head and for manually selecting between full pulsation and no pulsation or a continuous water spray. After extensive testing and use of known pulsating shower heads, it has been found desirable to provide for cycling the flow rate through the shower head between a low flow rate and a high flow rate to provide for not only water savings but also for the different sensations of a changing flow rate. When the cycling at the flow rate is used in combination with pulsation, the cycling pulsation between low and high frequency cooperates with the cycling between minimum and maximum flow rate to provide for an improved massaging action which is more desirable than a constant speed pulsation. It has also been found desirable for a pulsating shower head to provide for infinitely adjusting the spray pattern between a tight or concentrated and more penetrating pattern and a wide spray or full pattern which provides for more delicate pulsating action.
SUMMARY OF THE INVENTION
The present invention is directed to an improved water spray device or shower head which provides all of the desirable features mentioned above, and which features may be selected separately or in combination. More specifically, the shower head of the present invention provides for selecting an automatic cycling feature when the flow rate cycles between a high or full flow rate and a low flow rate to provide for a different sensation as well as a significant water savings, for example, up to 25%. This cycling flow rate may also be used in combination with the feature of pulsation which may be selected between low and high frequencies or full pulsation may be selected without cycling. In addition, the shower head of the invention provides for infinitely adjusting the spray pattern between a tight and more concentrated penetrating pattern and a full wide spray pattern, depending upon the water action desired.
In general, the above features are provided by shower head which includes a housing enclosing and supporting a first rotary valve member driven by a turbine wheel and a gear reducer for automatically cycling the flow rate through the shower head between high and low rates, and a manually rotatable cross valve shaft provides for selecting the degree of cycling. A second rotary valve member is formed as part of a second turbine wheel for pulsating the cycling flow rate, and further rotation of the cross valve shaft provides for hydraulically shifting and stopping the second valve member for bypassing the water pulsation when a continuous spray discharge is desired. A plurality of rotatable water discharge caps support the outer ends of groups of flexible tubes to provide for discharging water streams from the shower head, and the caps are rotated in unison in response to rotation of a control ring for slightly twisting the flexible tubes to select a spray pattern between a tight penetrating pattern and a wide full range pattern.
Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a shower head constructed in accordance with the invention;
FIG. 2 is an axial section of the shower head shown in FIG. 1;
FIG. 3 is a section taken generally on the line 3--3 of FIG. 2;
FIG. 4 is a section taken generally on the line 4--4 of FIG. 2;
FIG. 5 is an enlarged fragmentary section of a portion of the shower head shown in FIG. 2;
FIG. 6 is an end view of a group of discharge tubes, taken generally on the line 6--6 of FIG. 5;
FIG. 7 is a section taken generally on the line 7--7 of FIG. 2; and
FIG. 8 is a section taken generally on the line 8--8 of FIG. 2;
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a shower head 15, the parts of which are primarily molded of rigid plastics material. The head 15 includes a generally cylindrical housing 16 which has a decorative outer surface such as a chrome plating. The housing 16 includes an upper annular cap section 18 having an internally threaded lower portion 19 and an externally threaded upper tubular neck portion 22 for receiving an internally threaded collar 24. Part-spherical surfaces are formed on the neck portion 22 and the collar 24 for engaging the spherical lower portion 27 of a tubular fitting 28 to provide a universal swivel connection between the housing 16 and the fitting 28. The fitting 28 is preferably formed of metal and has an upper portion 29 with straight knurls and internal threads for attaching the fitting to a water supply line.
The housing 16 also includes a cylindrical intermediate section 32 which has a reduced upper annular portion 33 with external threads for receiving the upper annular cap section 18. A water flow deflector 36 is inserted into the portion 33 and has an upper conical portion 37 which is molded as an integral part of an annular channel portion 39 defining an upwardly facing annular chamber 42. A plurality of circumferentially spaced ports 44 extend tangentially through the inner wall of the channel portion 39. When pressurized water flows through the fitting 28 into an upper chamber 47 within the housing section 18 and into the annular chamber 42, the water then flows inwardly through the ports 44 for rotating a turbine wheel 52 mounted on the input shaft of a gear reducer box or unit 55. The gear reducer unit 55 is known in the field of pulsating shower heads and includes a cylindrical housing 56 enclosing a series of molded plastic gears (not shown) which provide a reduction ratio of about 400 to 1 between rotation of the turbine wheel 52 on the input shaft and the rotation of an output shaft 58. A reduced lower end portion of the housing 56 seats within a counterbore of a circular valve body 64 which slides into the housing section 32 during assembly. A resilient O-ring 66 forms a water-tight seal between the housing section 32 and the valve body 64 and separates an annular water chamber 68 surrounding the gear reducer unit 55 and a chamber 72 within the valve body 64.
The valve body 64 has an axially extending hole 74 (FIG. 4) which receives water flowing from the bottom of the turbine wheel 52 and through the annular chamber 68. A radially extending port 76 connects the hole 74 to a chamber 78 defined by the valve body 64 and receiving the output shaft 58 of the gear reducer unit 55.
An inverted cup-shaped cylindrical valve member 82 is secured to the output shaft 58 of the gear reducer unit 55 and rotates within the chamber 78 which extends into a lower cup-shaped portion 84 of the valve body 64. As shown in FIG. 4, the upper portion of the valve member 82 has a set of spoke-like ribs 86 which define therebetween water flow passages 88. The valve member 82 also has a set of two diametrically opposed ports 91 (FIG. 4), and the lower portion of the valve housing 64 has a radial port 93. The ports 91 within the valve member 82 are sufficiently large so that the port 93 is always at least partially open to one of the ports 91.
As the water flows inwardly through the ports 76 within the valve body 64 and downwardly into the rotating valve member 82 through the passages 88, the water flows outwardly through the ports 91 and 93 in a variable flow rate which varies from a full flow rate to a very low flow rate into the chamber 72. The valve body 64 also includes an axially extending by-pass passage 96 (FIGS. 2 & 4) through which water may flow from the chamber 68 rather than through the rotating valve member 82. When a full variable flow rate is desired, the passage 96 is closed by manually rotating a cross valve shaft 100 which is rotatably supported by a cylindrical valve body 102 inserted into a counterbore within the housing section 32. The valve shaft 100 has a diametrically extending port 104 which may be aligned with a passage 105 within the valve body 102 and forming an extension of the passage 96. A cap-like knob 106 is secured to the outer end portion of the valve shaft 100 by a lock screw 107, and a pair of resilient O-rings 108 form water-tight seals between the valve body 102 and the opposite end portions of the valve shaft 100. When the knob 106 is rotated from the position shown in FIG. 2, the port 104 aligns with the passages 96 and 105 and permits a direct flow of water from the chamber 68 through the chamber valve bodies 64 and 102. When the knob 106 is rotated to the position shown in FIG. 2, all of the water flowing through the chamber 68 must flow through the rotating valve member 82 which produces cycling of the flow rate. The degree of flow rate cycling may be controlled by rotating the knob 106 to change the proportion of the water flowing through the passages 93 and 96.
The lower portion 84 of the valve body 64 projects into a center cavity within the top of the valve body 102 and has a center hole 110 which aligns with a port 112 within the valve shaft 100 and a port 113 within the valve body 102 when the valve shaft 100 is rotated. The valve shaft 100 also has a radial port 114 which aligns with a passage 116 within the valve body 102 when the valve shaft 100 is rotated to permit water to flow from the chamber 72 into an annular chamber 118 formed within a bottom housing cap member 120 threaded onto the lower end portion of the housing section 32. A set of circumferentially spaced directional ports 123 (FIGS. 2 & 7) extend tangentially through an annular wall of the bottom cap member 120 for directing the water flowing into the annular chamber 118 inwardly into a circular turbine chamber 126 defined by the lower cap member 120.
A turbine wheel valve member 128 is rotatably supported within the chamber 126 by a tubular shaft 129 projecting downwardly from the valve body 102 and forming a continuation of the port 113. The turbine wheel valve member 128 has a bottom tapered hub 131 which projects into a tapered cavity 132 and includes a series of peripherally spaced radially extending vanes 134. The vanes 134 are impinged by the water streams flowing through the directional ports 123 for rotating the valve member 128 within the chamber 126. Referring to FIGS. 2 & 7, the turbine wheel valve member 128 has a flat annular bottom wall 136 which defines an arcuate opening 138 extending approximately 135°. The radial vanes 134 within the opening 138 are rigidly connected by a peripherally extending bottom ring 141. When the valve member 128 is rotating, the bottom wall 136 of the valve member 128 rotates with a very slight clearance above a flat annular surface 143 (FIG. 2) within the bottom cap member 120.
A control ring 150 is supported for rotation by the bottom cap member 120 and is retained on the cap member by a pin 152 which projects radially inwardly through the ring 150 and into a circumferentially extending groove 153 (FIG. 5) within the cap member 120. A circular bottom plate 155 (FIG. 5) is confined within the control ring 150 and is positively secured to the cap member 120 by a center screw 156. A plurality of three cup-shaped discharge caps 160 (FIGS. 1, 2 & 5) have upper circular flanges 161 each of which is supported for rotation by mating counterbores within the cap member 120 and bottom plate 155. Each cap 160 supports the outer end portions of a plurality of seven flexible orifice tubes 162 which are preferably formed from sections of an extruded tube of plastics material such as polyethylene and having an inner diameter of about 5/64 inch. The inner end portions of the tubes 162 are confined within corresponding counterbores formed within the cap member 120, and each tube 162 defines a passage or orifice 166 which aligns with a corresponding hole or port 167 extending from the flat annular surface 143 of the cap member 120.
Referring to FIG. 8, the upper flange 161 of each cap 160 includes a pair of outwardly projecting and peripherally-spaced triangular-shaped ears 172 and 173 with the ear 172 located above the ear 173 (FIG. 5). A set of two cam rings 177 and 178 are connected for rotation with the control ring 150, and the cam rings are positioned for engaging the ears 172 and 173, respectively, as shown in FIG. 5. Each of the cam rings has an inner cam surface 181 with the surface 181 on one cam ring being the reverse of the surface on the other cam ring. The surfaces 181 are effective to rotate the caps 160 through a few degrees in opposite directions in response to rotation of the control ring 150 and cam rings 177 and 178 in corresponding opposite directions through a substantially greater degree of rotation. As shown in FIG. 1, when each of the caps 160 rotates, the corresponding group of orifice tubes 162 are twisted for changing the spray pattern from each cap 160 between a concentrated or tight pattern 184 and a full or wide pattern 186. The spray patterns from all of the caps 160 simultaneously change in response to rotation of the control ring 150.
Referring to FIGS. 2 and 5, when the valve shaft 100 is rotated to a position where the port 112 connects the port 110 to the port 113, water flows downwardly through the tubular shaft 129 and hydraulically elevates the turbine valve member 128 on the shaft 129 until one of the vanes 134 engages a stop 197 (FIG. 5). This stops rotation of the elevated valve member 128 and allows the water to flow through the shaft 129 and outwardly under the bottom wall 136 of the turbine valve member and directly into the inlets or ports 167 for the orifice tubes 162. When the turbine valve member 128 is elevated and is blocked from rotating, there is no pulsation of the water streams flowing through the orifice tubes 162 so that all of the tubes receive a continuous flow of water.
From the drawings and the above description, it is apparent that a shower head constructed in accordance with the present invention, provides desirable features and advantages. As one feature, the cycling flow rate between a low flow rate such as 2.25 gallons per minute and a high flow rate such as 3 gallons per minute, as produced by the rotating valve member 82, provides a significant water savings as well as the advantage of a high flow rate several times a minute. Another feature is provided by the water pulsation produced by the rotating turbine valve member 128 and which may be combined with the cycling feature to provide cycling pulsation between low flow and slower pulsations and a high flow and faster pulsations. This combination provides a distinctive massaging action which is not obtained by only pulsation at a constant frequency. The adjustable rotation of the caps 160 and the corresponding twisting of the groups of orifice tubes 162 further provides for adjusting the spray pattern infinitely between a concentrated and more penetrating pattern and a full wide spray pattern when a more delicate pulsating action is desired. In addition, the control knob 106 and valve shaft 100 provide for selecting between full pulsation without cycling and full flow without cycling or pulsation.
While the form of shower head herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of shower head, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims. | A shower head includes a housing enclosing a first rotary valve member driven by a turbine wheel and gear reducer for cycling the flow rate through the housing between high and low flow rates, and a manually rotatable cross valve shaft provides for selecting the degree of cycling. A second rotary valve member is combined with a second turbine wheel for pulsating the cycling flow rate, and further rotation of the valve shaft provides for hydraulically shifting and stopping the second valve member for bypassing the pulsation to provide a full continuous water flow. Water is discharged from the shower head through flexible tubes arranged in groups which are twisted in response to rotation of a control ring for selecting a spray pattern between a tight penetrating pattern and a wide full pattern. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application of my co-pending application Ser. No. 264,728, filed May 18, 1981, entitled "Concentric Walled Conduit For A Tubular Conduit String" which is now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to an insulated conduit having particular utility in subterranean wells and more particularly to a concentric walled insulated conduit having an annular space between the walls within which is deposited an insulating material and sealed therein.
2. Description of the Prior Art
In producing some subterranean wells, steam is injected into an injection well to increase recovery of hydrocarbons and for reducing high viscosity crude oil, otherwise known as "heavy crude", to a viscosity making it more readily pumpable. One technique for doing this is to inject a high quantity of steam into the production zone containing "heavy crude" for an extended period of time, such as from about three to about five weeks, at which point the viscosity of the heated crude will be reduced, and, thus made readily pumpable, through a production well in communication with the production zone, or by modifying the injection well. A steam "flood" may also be provided by known techniques, generally through an injection well, to drive the flood and the produced hydrocarbons to a nearby production well.
One of the major problems in injecting steam into a subterranean production zone through conventional well production tubing is that the steam loses a large quantity of its heat to the well bore casing and surrounding formation as it travels downwardly to the production zone.
Attempts have been made in the past to reduce the heat loss of steam introduced into subterranean formations, one such attempt being shown in U.S. Pat. No. 3,511,282, issued on May 12, 1970. This patent discloses a dual-wall tube structure having insulation sealed in the annulus between the inner and outer walls by bushings respectively welded at each end between the inner wall and the outer wall. The inner wall is prestressed in tension prior to being welded to the outer wall. The space defined between the inner and outer walls is filled with a conventional insulating material, such as calcium silicate. Although this technique may be satisfactory in some oil field installations, it is not satisfactory for all oil field installations where large temperature differentials are encountered between the inner and outer walls. In this case, even though the inner wall is prestressed in tension, the inner wall as it is heated will elongate with respect to the outer wall so that the inner wall may even change from a tension to a compression condition with the attendant danger of buckling. The magnitudes of the forces generated are such that localized stresses are created in the weld areas causing cracks which permit exposure of the insulation to well fluids and eventually causing failure or degradation of the insulating structure. Centralizers are incorporated to reduce buckling, but may also, in turn, contribute to a loss of heat because of the generally durable nature of such devices.
Another known technique of handling the aforedescribed temperature differential and resulting elongation between the inner and outer walls of an insulating tube is to place a thin walled bellows between the two walls at each end of the assembly, one end of each of the bellows being rigidly attached to the inner wall, and the other end of the bellows being rigidly attached to the outer wall. This technique, of course, relieves the strain on the welds and joining structure between the walls due to the relative movement between the inner and outer walls. However, the bellows introduce other problems, namely, the bellows are comparatively thin walled and delicate, being typically formed from a heat resistant, springly material, which cannot withstand the rough handling normally encountered in the oil patch.
SUMMARY OF THE INVENTION
Generally, a concentric walled conduit constructed in accordance with the invention incorporates corrugating one of the tubular members, preferably the inner tubular member, along its substantially entire length, so that when it is relatively hot and the outer tube is relatively cool, its tendency is to elongate without generating any excessive forces acting on the concentric members or the securing means connecting such members.
More particularly, the concentric walled conduit structure generally comprises an outer conventional well tubular member surrounding a rugged corrugated inner tubular member to define an annular space therebetween. The ends of the inner tubular member are fixedly secured to the inside diameter of the outer tubular member. The adjoining ends of the tubular members are welded, flared or otherwise rigidly secured together to effectively seal the annular space provided between the two tubular members. The corrugations assist in preventing the insulation from compacting during use.
The space formed between the inner and outer tubular member provides an insulating barrier. Insulating material may be incorporated within this space to reduce heat loss. This insulating material may form a convective insulating barrier or it may constitute a reflective radiation shield. The reflective radiation shield may be combined with a vacuum to prevent radiant and convective heat loss. An insulating blanket, forming a convective insulating barrier which is capable of resisting deformation by tensile and shear forces, or the like, may be disposed or wrapped around and secured to the outer surface of the corrugated inner tubular member before it is secured within the outer tubular member, thus filling the space provided therebetween.
Further, the corrugated inner tubular member can be prestressed in tension and secured in this state to the outer tubular member so that when it is in its heated elongated state, due to the passage of steam therethrough, such that the resultant forces acting thereon will not be compressive.
Also, the ends of the corrugated inner tubular member can be connected to the inner surface of the outer tubular members in a manner wherein reduced loads are applied to the weld or other connections which serve as seals for the space provided between the two tubular members.
Additionally, the tubular members may be affixed at one or both ends to one another in a flared configuration which greatly reduces the distortion of the connecting threads on the outer tubular member. Furthermore, flaring will permit only minimum thermal conduction along the comparatively thinned walled inner tubular member; will permit passage of oil tools or work strings through the conduit without "hang up" of the tools, etc., on a shoulder; and eliminates at least one set of welds.
A primary object of this invention is to produce a concentric walled conduit having a space between two tubular members, wherein the integrity of the sealed rigid connections, such as welds, between the two tubular members is increased, both by reducing the forces acting through the heated inner tubular member on the connections and by reducing the number of connections.
Another object of this invention is to produce a concentric walled conduit wherein forces generated by the heated corrugated inner tubular member are applied on the relatively cooler outer tubular member and not on the means sealing the space between the two tubular members, thereby greatly reducing the load on the weld.
Yet another object of this invention is to prestress a fixed corrugated inner tubular member in tension so that when it is heated, its elongation will not generate any destructive forces acting on the concentric walled conduit, caused by buckling acting on the insulation.
Other objects and advantages of the invention will become more apparent in the course of the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view partly in section of a concentric walled conduit constructed in accordance with the invention.
FIG. 2 is a view similar to FIG. 1, but illustrating a different joining structure for connecting the ends of the inner tubular member to the adjacent ends of the outer tubular member.
FIG. 3 is a view similar to FIG. 1, but illustrating another embodiment of the invention.
FIG. 4 is a view similar to FIG. 2, illustrating a third embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, there is illustrated a number of concentric walled conduits and respectively designated in their entirety by the reference numerals 10, 10a, 10b and 10c. Generally, each insulating tube comprises a corrugated inner tubular member 11, 11a, 11b and 11c, respectively, assembled concentrically within an outer tubular member tube 12, 12a, 12b and 12c. The outer tubular member preferably comprises standard well tubing. The wall of the inner tubular member may be corrugated in the form of a sine wave, or in the form of a helical thread. The wall thickness of the inner tubular member is on the same order as conventional well tubing of the same diameter, thus providing a structurally rugged element but having axial springness. The inner and outer tubular members are rigidly secured to each other, either directly by welds or indirectly by structural members to be described hereinafter. An annular space 13, provided between the two tubular members is preferably filled with a blanket-type insulation material 14, such as batts of woven glass or ceramic fiber, or the like, which form a convective insulating barrier and which will withstand temperatures encountered in steam injection operations, such as 700° F. without deteriorating and/or decomposing, thus continuing to provide effective thermal insulation at these high temperatures. Conventional insulating blanket material having fibrous materials interspersed therein can be used to provide this convective insulating barrier. These fibrous materials may be either a glass-containing or a ceramic-containing material. These conventional insulating blankets with ceramic-containing or glass-containing fibers are readily available from commercial sources and are used in the preferred embodiments of this invention in their commercially available form. The insulation is wrapped around the outer periphery of the inner tubular member and firmly secured thereto by a wire or wrapping 15 wound in a helical manner around the insulation and the inner tubular member. The ends of the wire or wrapping 15 may be fastened to the inner tubular member by a tack weld (not shown) or fastened mechanically. The wire or wrapping 15 thus prevents settling of insulation 14.
As stated, the outer tubular member of the dual walled conduit is a standard well tubing joint employed in the oil field industry. Also it should be noted that the structural load is carried by the outer tubular member and employs standard buttress or other threads at each end of the outer tubular member to receive a coupling, or companionly threaded end of another concentric walled conduit, and so on, to form a continuous length or string of concentric walled insulated conduits.
Referring now to FIG. 1, it is seen that the ends of the inner tubular member 10 are respectively provided with straight portions 16 and flared portions 17 and 17' with the end of each flared portion 17 and 17' being respectively secured to the inner surface of the outer tubular member 10 by welds 18 and 18'. Also, it will be noted that the flared portions 17 and 17' define the annular space 13 in this embodiment of the invention for receiving the insulation 14. In this case, the straight portions 16 and 16' conveniently provide transition surfaces between the flared ends and the corrugated portions of the corrugated inner tubular member 11. It should be noted that the flared portions 17 and 17' are radially spaced from the corrugations on inner tubular member 11. In order to prevent heat loss it is essential that the corrugations, whether sinusoidal or helical, not come into contact with the outer tubular member. The "flared portions" 17 and 17', located only at the ends of inner tubular member 11, are provided to establish contact with the outer tubular member 12 while at the same time reducing the number of welds.
In the embodiment of the invention illustrated in FIG. 2, annular welding rings 19 and 19' are respectively provided at the ends of the straight portions 16a and 16a' of the corrugated inner tubular member 11a. The welding rings 19 and 19' are first welded to the ends of the inner tubular member by welds 20-20' and 21-21' and then to the inner surfaces of the ends of outer tubular member 10a by welds 22 and 22'. In this case, the welding rings 19 and 19' define the annular space 13 for receiving the insulation 14.
Referring now to the embodiment of the invention illustrated in FIG. 3, the opposite ends of the outer tubular member 12b are respectively provided with end adapters 23 and 24. The end adapters 23 and 24 are welded to the outer tubular member 12b and are provided with standard male buttress or other threads. The thick walls of the adapters prevent distortion of the threads during the welding process previously described for the embodiment illustrated in FIG. 1. Otherwise, the structure of this embodiment is the same as the structure disclosed in the embodiment illustrated in FIG. 1.
In the embodiment of the invention illustrated in FIG. 4, the inner and outer tubular members 11c and 12c respectively are joined structurally by a technique for prestressing the inner tubular member in tension without applying any loads on the welds employed for sealing the annular space 13 defined between the two tubular members. Referring first to the joining means located at the top end of the concentric walled conduit 10c, there is shown a spacer-weld ring 25 positioned between the tubular members 11c and 12c. More specifically, the spacer-weld ring 25 is provided with internal threads 26 and the adjacent surface of the inner tubular member 11c is provided with cooperating external threads 27 for fastening the ring 25 thereon. Preferably, the outside diameter 28 of the ring 25 has an interference fit with the inside diameter of the outer tubular member 12c, such that it conforms to a shoulder 29 therein. Accordingly, the tubular member 11c is prevented from moving in an axial direction toward the opposite end of the outer tubular member. The ring 25 can be secured to the inner tubular member tube by both a face weld 30 and a corner weld 31. Also the ring 25 is secured to the outer tubular member by a face weld 32. It should be noted that this end of the inner tubular member is mechanically joined to the outer tubular member by the threaded connection 26-27 and the shoulder 29 and transmits any forces produced by the inner tubular member directly to the other tubular member, and that the welds 30, 31 and 32 only serve as seals for this end of the annular space 13.
Referring now to the joining means located at the bottom end of the concentric walled conduit 10c, there is shown a structure comprising a body lock ring 33 and a body lock ring housing 34, both positioned in an annular gap 35 defined between the straight portion 16c' of the inner tubular member 11c and the adjacent surface of the outer tubular member 12c and held against longitudinal movement in one axial direction by a snap ring 36. The body lock ring 33 includes wickers 37 formed on its inner surface for preventing the loss of tension applied to the inner tubular member 11c. More specifically, the snap ring 36, the body lock ring 33 and the body housing 34 are placed in the gap 35 between the tubular members, and the inner tubular member 11c is prestressed in tension and then released.
The inner tubular member 11c may be prestressed by elongating it by means of a hydraulic cylinder (not shown) pulling on a mandrel (not shown) attached to the inside diameter of the inner tubular member so that the inner tubular member will be elongated relative to the outer tubular member 12c. When the inner tubular member tube 11c is released, the wickers 37 will bite into the outer surface thereof and transmit the tension force to the body lock ring housing 34 through a thread assembly 38. Thus, the inner face between the lock ring housing 34 and the snap ring 36 transmits forces produced by the inner tubular member directly to the outer tubular member 12c.
An inverted V-shaped weld ring 39 is positioned in the gap 35 between the inner and outer tubular members and is affixed thereto by continuous welds 40 and 41 for sealing the space 13. From the foregoing, it is apparent that the prestress forces of the inner tubular member are transmitted directly to the outer tubular member without being applied to the weld seams. In other words, no load is applied to the weld seams.
It should be noted that prestressing of the inner tubular member in tension is not limited to the embodiment of FIG. 4. If comparatively large temperature differentials are expected to be encountered, the inner tubular member may be elongated prior to attachment to the outer member to incorporate the desired prestress into the assembly.
Subsequent to affixation of the second ends of the tubular members, the annular area may be sealingly communicated with vacuum means for evacuating moisture and/or air therein to improve the insulating capacity of the conduit. Sealing communication with the vacuum means may be accomplished by providing a sealable opening in the outer tubular member.
The thermal insulating material may also comprise a reflective heat shield element or skin having low thermal emissivity to provide maximum heat shielding characteristics. A conventional aluminum foil may be employed to provide this radiant reflective heat shield barrier.
although the invention has been described in terms of specified embodiments which are set forth in detail, it should be understood that this is by illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention. | A concentric walled conduit for incorporation within a tubular conduit string, and particularly for use in a subterranean well, is provided with one of the walls corrugated for substantially its entire length, preferably the inner tubular member. The annular space defined between the concentric tubular member contains a high heat resistant insulating material disposed around the outer surface of the inner tubular member. Each end of the annular space containing the insulating material is effectively sealed, and secured, such as by welds. The inner wall may be prestressed in tension for counteracting the forces which may be produced by a temperature differential between the tubular member walls of concentric conduit. | 8 |
BACKGROUND OF THE INVENTION
Dual mode searchlights are used in rotorcraft to provide both visible lighting and infrared (IR) lighting modes, depending on the task and conditions the rotorcraft is operating under. U.S. Pat. No. 5,695,272 to Snyder et al. titled “Searchlight For Aircraft And Other Vehicles,” herein incorporated by reference, describes an exemplary visible and infrared lighting element in a lamp head that may be extended, retracted, and rotated. Both light sources, however, are within the same lamp head (and the same lamp face), so that heat generated from the visible light source is not dissipated sufficiently to prevent degradation of the IR light source due to high temperatures generated by the heat from the visible light source. U.S. Pat. No. 6,962,423 to Hamilton et al. titled “Multi-mode Searchlight,” herein incorporated by reference, describes a multi-mode visible and infrared lighthead for use as a landing light or searchlight. The design includes a separate reflector which must be attached to the housing, and which increases maintenance costs and time.
Therefore, there exists a need for an improved dual-mode searchlight.
SUMMARY OF THE INVENTION
Preferred embodiments of the present invention meet all of the above needs in providing a dual-mode visible and infrared (IR) searchlight assembly with an insulating barrier between the visible and IR portions of the assembly, and integral reflector.
The two illumination sources are separated with insulation material and an air gap to improve illumination performance and meet severe operating conditions. The separation provides cooling from convective heat transfer and greatly reduces conductive heat transfer from the high power visible lighting portion of the canopy to the IR illumination portion of the canopy. The IR portion of the canopy is isolated to protect the IR sources from high temperatures.
The reflective device for visible illumination is integrated into the housing to increase reflector area and reduce maintenance costs and time. The increase in reflector area has a direct positive effect on visible light intensity. Embodiments may include U.S. Pat. No. 6,960,776 to Machi titled “IR Diode Based High Intensity Light,” herein incorporated by reference, which describes a high intensity, low power infrared light assembly for use on aircraft or other vehicles for landing, taxi mode, or search operations. These features contribute to reducing the size of the envelope required to harness the IR illumination sources, reducing the amount of heat generated by the searchlight, and allows the visible portion of the canopy to be larger, increasing reflector area and thus visible light intensity.
As will be readily appreciated from the foregoing summary, the invention provides an improved lighthead assembly for aircraft.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings:
FIG. 1A is a top rear perspective view of a housing formed in accordance with an embodiment of the present invention;
FIG. 1B is a bottom plan view of the housing of FIG. 1A ;
FIG. 1C is a rear plan view of the housing of FIG. 1A ;
FIG. 1D is a cross-sectional view through the line 1 D of FIG. 1C ;
FIG. 1E is a cross-sectional view through the line 1 E of FIG. 1C ;
FIG. 1F is a perspective view of a housing cover formed in accordance with an embodiment of the present invention;
FIG. 1G is an exploded view of a housing assembly formed in accordance with an embodiment of the present invention;
FIG. 2A is an exploded view of an infrared (IR) light source assembly formed in accordance with an embodiment of the present invention;
FIGS. 2B and 2C are perspective views of the heat sink of the IR light source assembly of FIG. 2A ;
FIG. 3A is an exploded view of a housing and an IR diode assembly;
FIG. 3B is a front plan view of a lighthead assembly formed in accordance with an embodiment of the present invention;
FIG. 3C is a partial exploded view of the lighthead assembly of FIG. 3B ;
FIG. 4A is a top perspective view of a lampholder assembly formed in accordance with an embodiment of the present invention;
FIG. 4B is an exploded view of the lampholder assembly of FIG. 4A ;
FIG. 5A is an insulator formed in accordance with an embodiment of the present invention; and
FIG. 5B is an insulating bushing formed in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1A shows a housing 10 including a housing rear 12 defining a plurality of lens retainer attachment points 14 located around a housing perimeter 16 ( FIG. 1G ). The housing rear 12 also defines a searchlight slip ring shaft receptacle 18 and at least one searchlight slip ring shaft attachment point 20 . The housing rear 12 also defines a pair of lamp receptacles 22 , along with a plurality of lampholder attachment points 24 and housing cover attachment points 26 . In FIG. 1B , the housing 10 also defines a plurality of infrared (IR) diode assembly attachment points 28 . In FIGS. 1D and 1E , the housing 10 defines a reflector 30 . The reflector 30 is cleaned, base coated, and then vacuum metallized. The reflector 30 should have a smooth reflective appearance and show no signs of distortion. The reflector 30 is then coated with aluminum or other suitable material known to those having skill in the art. FIG. 1F shows a housing cover 31 defining a plurality of threaded receptacles 29 through which screws 108 ( FIG. 3C ) may be inserted and attached to the housing cover attachment points 26 .
Referring to FIG. 1G , a lens retainer 32 is attached to the housing 10 with a plurality of screws 34 at the lens retainer attachment points 14 ( FIG. 1A ). The lens retainer 32 holds a gasket 36 and a lens 38 in place against the housing perimeter 16 .
FIG. 2A shows an IR diode assembly 40 . The assembly 40 includes an aluminum (or other suitable material) heat sink 42 defining a plurality of retainer attachment points 44 . A retainer 46 is attached to the heat sink 42 at the retainer attachment points 44 with a plurality of screws 48 , and houses various components of the assembly 40 . A circuit card assembly 50 is attached to the heat sink 42 at a plurality of circuit card attachment points 52 with a plurality of screws 54 . Wiring 56 from the circuit card assembly 50 may be encased in tubing 58 . The wiring 56 exits the heat sink 42 through a wiring receptacle 57 ( FIG. 2C ). A plurality of thermally conductive and electrically non-conductive silicon pads 60 , IR diodes 62 , diode heat sinks 64 , aspheric lenses 66 , and diffuser retainers 68 are attached to the heat sink 42 with a plurality of screws 70 at a plurality of retainer attachment points 72 . The assembly 40 includes a diode gasket 74 , a light shaping diffuser 76 , and a lens 78 for each diode 62 ; an O-ring 80 seals the components within the retainer 46 , and the lenses 78 extend into lens receptacles 82 of the retainer 46 . Aspheric lenses 66 and light shaping diffusers 76 act to collimate the IR energy into a desired pattern.
In FIGS. 2B and 2C , the heat sink 42 defines a plurality of housing attachment points 84 through which screws 88 ( FIG. 3A ) are inserted and attached to the IR light source assembly attachment points 28 of the housing 10 ( FIG. 1B ). The wiring receptacle 57 allows the wiring 56 from the circuit card assembly 50 to exit the heat sink 42 .
FIG. 3A shows the IR light source assembly 40 and housing 10 . The IR light source assembly 40 is attached to, and only contacts the housing 10 at, the IR light source attachment points 28 of the housing 10 with a plurality of screws 88 , insulating bushings 90 , and washers 92 . Between the housing 10 and the IR light source assembly 40 , a plurality of insulating bushings 90 and an insulator 96 separate and reduce the amount of heat conduction between the canopy 10 and IR light source assembly 40 . A pair of O-rings 97 seal the wiring 56 . The insulating bushings 90 and insulators 96 are preferably made of polyethertherketone (PEEK) 1000, but other insulating materials known to those having ordinary skill in the art may be used.
FIG. 3B shows a lighthead assembly 98 . A space 99 allows air flow between the IR light source assembly 40 and the housing perimeter 16 , thus reducing the amount of heat convection between the housing 10 and the IR light source assembly 40 ; the space 99 also helps to prolong IR diode 62 life by reducing direct heat conduction between the housing 10 and the IR light source assembly 40 . The generally circular shape of the lighthead assembly 98 allows easier adaptation of the lighthead assembly 96 to conventional dual-mode lighthead envelopes (not shown).
FIG. 3C shows the lighthead assembly 98 . A pair of lampholder assemblies 100 is attached to the housing 10 with a plurality of screws 104 , with lamps 102 attached to the lampholder assemblies 100 protruding through the lamp receptacles 22 . The housing cover 31 and a housing cover O-ring 106 are attached to the housing 10 with a plurality of screws 108 , and enclose the lampholder assemblies 100 .
FIGS. 4A and 4B show one lampholder assembly 100 . The assembly 100 includes screws 110 attaching a socket 112 to a lampholder 114 via self-locking nuts 116 . Screws 118 secure the lampholder 114 to the housing 10 ( FIG. 1A ).
FIGS. 5A and 5B show an insulator 96 and an insulating bushing 90 , respectively. In an embodiment, the insulator 96 and insulating bushing 90 are made of polyethertherketone (PEEK) 1000, but could be made of any of a variety of different insulating materials.
While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow. | A lighthead for a dual-mode searchlight including a generally concave housing with an attached infrared (IR) light source assembly, an insulating barrier and air gap between the visible and IR portions of the assembly, and a reflector integral to the housing. | 1 |
TECHNICAL FIELD
The present invention relates to a temperature control system and, more particularly, to a temperature control system for a mold.
BACKGROUND
In the process of injection molding, hot molten thermoplastics are periodically injected into a cold mold. Without mold temperature control, the cavity surface will be heated unevenly due to the constant supply of heat from the molten plastic. Therefore, temperature control is a major prerequisite for achieving high molding quality.
A typical temperature control system 99 for a mold is represented in FIG. 5 . The temperature control system 99 is shown in use in a mold apparatus. The mold apparatus includes a housing 92 and a media cavity 93 defined therein. The temperature control system 99 includes a control panel 94 , a heat exchanger 95 , a heater 96 , a first electromagnetic valve 98 and a second electromagnetic valve 97 . The control panel 94 is located on the housing 92 . The mold body 102 also defines therein a media channel (not shown) communicating with the media cavity 93 . The media cavity 93 is filled with a media fluid, which flows in the channels for heating or cooling the housing 92 during molding. The heat exchanger 95 is disposed in the media cavity 93 , and the heater 96 is disposed on the outside of the media cavity 93 for heating the media fluid. The heat exchanger 95 is connected with the controlling panel 94 and the second electromagnetic valve 97 for controlling the mold cooling process. The heater 96 is connected with the controlling panel 94 and the first electromagnetic valve 98 for controlling the mold heating process. In use, the heater 96 heats the media cavity 93 . Then, the media cavity 93 further heats the media fluid. The media fluid transmits the energy to the mold cavity. When cooling, the heat exchanger 95 is filled with cooling water which carries energy from the media fluid so as to decrease the temperature of the mold. Users may control the first electromagnetic valve 98 and the second electromagnetic valve 97 by means of the controlling panel 94 thus enabling the user to control the heating and cooling processes of the mold. However, conventional temperature control systems use an electrical method of heating. This method consumes large amounts of electrical energy both in the heating and in the cooling processes of the mold.
Therefore, a new temperature control system is desired in order to overcome the above-described problems.
SUMMARY OF THE INVENTION
One embodiment of the temperature control system includes a heating system, a cooling system and a control unit. The heating system includes a heated fluid. The heated fluid is heated by solar energy for increasing the mold temperature. The cooling system has a cooled fluid. The cooled fluid can be used for decreasing the mold temperature. The control unit controls the activation of the heating system and the cooling system.
Other advantages and novel features of the present temperature control system will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the temperature control system for a mold can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is a schematic view of an embodiment of the present temperature control system for a mold;
FIG. 2 is a schematic view of the heating system of FIG. 1 ;
FIG. 3 is an isometric view of the collector of FIG. 1 ;
FIG. 4 is a schematic view of the cooling system of FIG. 1 ; and
FIG. 5 is a schematic view of a conventional temperature control system for a mold.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring now to the drawings in detail, FIG. 1 shows a temperature control system 100 , applied to an injecting mold. It is to be understood, however, that the temperature control system 100 could also be used in other environments (e.g. casting molds). As such, although proving particularly advantageous when used in injecting mold, the temperature control system 100 should not be considered limited in scope solely to an intended use environment. The injecting mold includes a mold body 102 with a media cavity 104 defined therein. The mold body 102 also defines therein a media channel (not shown) communicating with the media cavity 104 . The media cavity 104 is filled with a media fluid, which flows in the channels for heating or cooling the mold body 102 during molding.
The temperature control system 100 , in the embodiment illustrated, includes a heating system 1 , a cooling system 2 and a control unit 3 . The heating system 1 includes a solar heating system 11 and an electrical system 30 .
Referring also to FIG. 2 , the solar heating system 11 includes a first electromagnetic valve 12 , a first pipe 14 , a first check valve 16 and a collector 18 . The above elements are connected with each other in that order by means of a fluid transmission channel, thereby forming a loop/circuit. The heating system 1 is filled with a heating fluid 10 , and the heating fluid 10 is circulated so as to heat the media fluid in the media cavity 104 , thereby heating the mold body.
The electromagnetic valve 12 acts as a switch for the heating system 1 , being capable of either blocking or allowing through-put of the fluid 10 . The first pipe 14 is disposed in the media cavity 104 . The first pipe 14 is configured to have a spiral structure in order to provide a larger contact area with the media fluid in the media cavity 104 . This design may help energy conduction and allow the mold to be heated fully. The check valve 16 is a one-way valve element which can ensure that the hot fluid 10 of the heating system 1 flows only along a single direction.
The collector 18 is an absorbing portion of the heating system 1 . The collector 18 is disposed at a position where the sun my directly irradiate it so that it may absorb solar energy. Referring also to FIG. 3 , the collector 18 includes an absorbing panel 82 , a selective coating 84 , heat insulation layer 86 and a transparent cover 88 . The absorbing panel 82 includes a number of parallel tubes (not labeled). The fluid 10 may pass through the tubes from an input end of the collector 18 to an output end of the collector 18 so that the fluid 10 is heated by the absorbing panel 82 . The selective coating 84 is disposed on the absorbing panel 82 . The selective coating 84 is chosen to have properties which permit the collector 18 to absorb a large portion of the sun's wave radiation. An example of the type of selective coating 84 is black chrome or other dark color paints which provide high absorption and low emissivity. The heat insulation layer 86 encloses the absorbing panel 82 at two sides and a bottom thereof, thereby decreasing heat conduction to the surrounding environment. The transparent cover 88 covers the absorbing panel 82 . The transparent cover 88 not only separates the absorbing panel 82 from the air to decrease the energy loss owing to heat conduction or heat convection, but also avoids impurities or dust to drop onto the absorbing panel 82 .
The flow of the heated fluid 10 of the solar heating system 11 may be driven to circulate under the thermo-syphon heat pipe principle. The electrical system 30 includes an electric heater 36 and a third electromagnetic valve 38 . The electric heater 36 is disposed outside of the mold cavity 104 for heating the mold and is electrically connected with the control panel 32 . The third electromagnetic valve 38 is for controlling the open and close of the electric heater 36 .
Referring to FIG. 4 , the cooling system 2 includes a second electromagnetic valve 22 , a second pipe 24 , a second check valve 26 and a heat exchanger 28 .
The second electromagnetic valve 22 act as a switch for the cooling system 2 , being capable of either blocking or allowing through-put of the cooled fluid 20 . The second pipe 24 is also disposed in the media cavity 104 . The second pipe 24 is also configured to have a spiral structure in order to provide a larger contact area with the media fluid in the media cavity 104 . This design may help heat conduction and allow the media fluid to fully cool. The second check valve 26 is a one-way valve element which can ensure that the cooled fluid 20 of the cooling system 2 flows along one direction only. The heat exchanger 28 allows heat energy to be discharged as part of the cooling system 2 . The heat exchanger 28 can be a kind of a fin tube heat exchanger. The fin tube heat exchanger may effectively improve heat transfer to the surrounding environment.
The control unit 3 includes a control panel 32 and a thermocouple 34 . The control panel 32 is connected with the first electromagnetic valve 12 , the second electromagnetic valve 22 and the third electromagnetic valve 38 . Users may send a control signal through the control panel 32 so as to control the opening and closing of the first electromagnetic valve 12 , the second electromagnetic valve 22 and the third electromagnetic valve 38 . The thermocouple 34 is electrically connected to the control panel 32 , thereby detecting the temperature of the mold. The detected result is shown on the control panel 32 so as to help users operate the mold.
In use, the collector 18 firstly collects the solar energy and stores the solar energy for use. Then, the first electromagnetic valve 12 is opened by means of the control panel 32 when the mold needs to be heated. The heat absorbed by the collector 18 evaporates the fluid 10 and the evaporated fluid 10 is transmitted along the first pipe 14 . The first pipe 14 conducts the heat energy of the heated fluid 10 to the media cavity 104 of the mold. Accordingly, the temperature of the mold is increased. After the fluid 10 transmits the heat energy to the mold, the temperature of the fluid 10 is decreased and thus condensed back to liquid. The fluid 10 with a decreased temperature under thermo-syphon heat pipe principle again flows into the collector 18 so as to be heated. After a number of such circulations, the mold can be heated to a temperature of about 100˜120 C.°. The control panel 32 may detect the temperature of the heated mold. If the mold temperature does not satisfy the required temperature, the control panel 32 will automatically control the third electromagnetic valve 38 to activate the electric heater 36 , heating the mold cavity until a desired temperature is reached. Because of the subsidiary solar heating system 11 , the mold temperature control system 100 may greatly decrease the electrical energy consumption. When the mold needs to be cooled, the second electromagnetic valve 22 is opened by means of the control panel 32 . The cool fluid 20 heated by the media fluid in the media cavity 104 , flows to the heater exchanger 28 under the thermo-syphon heat pipe principle. The heat energy of the fluid 20 is transferred to the heater exchanger 28 and then dissipated to ambient air. After a number of circulations, the mold temperature will drop to the desired temperature.
In the above-mentioned embodiments, the spiral structure of the first heat pipe act as a first condensing portion, and the collector thereof act as a first evaporating portion. The first condensing portion is received in the media cavity, and the first evaporating portion is located outside the media cavity. Understandably, the first condensing portion disclosed above may be replaced with other structures.
In the above embodiment, the electrical heater is configured for heating the mold body to a predetermined temperature which the mold body cannot reach if heated by the first heat pipe alone.
In the above embodiment, the temperature control system may adopt oils as heating transfer medium or cooling transfer medium. The use of a solar power is a more environmentally friendly source of power.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention. | A temperature control system ( 100 ) includes a heating system ( 1 ), a cooling system ( 2 ) and a control unit ( 3 ). The heating system has a heated fluid. The heated fluid is heated by a solar energy for increasing the mold temperature. The cooling system has a cooled fluid. The cooled fluid cools for decreasing the mold temperature. The control unit controls the heating system and the cooling system to be opened or closed. | 1 |
[0001] The invention relates to fractional horsepower motors and, particularly, to the construction of a permanent magnet brushless DC motor.
PRIOR ART
[0002] Small electric motors such as shaded pole motors can be inexpensive to produce, but have relatively low efficiency. Many applications for such motors can be significantly benefitted from a motor with increased efficiency. An example of such an application is air circulation in a refrigeration system where inefficiency is compounded by the need to remove heat generated by the motor. U.S. Pat. Nos. 3,158,769, 3,959,678, 4,234,810 and 5,036,237 disclose examples of shaded pole motors useful in commercial refrigeration systems. Conventional brushless DC motors are known to achieve relatively high efficiency but involve increased componentry and manufacturing costs.
[0003] There continues to be a need for improving the efficiency and reducing the manufacturing costs of small electric motors.
SUMMARY OF THE INVENTION
[0004] The invention relates to small electric motors constructed with a unique brushless DC drive that is both relatively high in efficiency and relatively low in cost. The disclosed motor drive circuit utilizes a microcontroller to control the delivery of current to the field windings in response to voltage signals that are inherently produced in the windings. The disclosed controller arrangement and operating mode reduces the number of power switches from what has been customary and eliminates the need for a rotor position sensor to operate the motor.
[0005] A feature of the drive circuit is a unipolar field operation that reduces the number of required power switches from what is ordinarily required and, consequently, reduces the manufacturing cost of the motor. The unipolar operation is made possible by use of a pole shape that produces an air gap that varies across the face of the pole. This air gap variation assures that a start-up position can be obtained that is off a neutral position with reference to the pole axis of the coils that are energized for start-up.
[0006] An additional benefit of the control circuit is its ability to control speed. Still further, the stator laminations as well as the stator housing body of existing prior art shaded pole motors can be used to practice the invention.
[0007] More specifically, the motor drive circuit is arranged to enable the microcontroller to monitor the back EMF of the field coils. The microcontroller is programmed to calculate the angular position of the rotor during a quarter of each revolution and this calculation, in turn, is used to regulate the dwell or angular displacement of the rotor through which power is applied to the field coils. The maximum dwell, for each phase of the poles is less than 90° of shaft rotation. The actual dwell produced by the microcontroller can be adjusted up or down to maintain a desired speed for an imposed load. The position calculator feature obviates the need for a rotor position sensing device and its attendant cost. The DC power, derived from a full bridge rectifier is applied in a unipolar arrangement wherein the poles do not change in polarity.
[0008] In summary, the overall simplicity and reduced number of components used in the disclosed motor system result in potential savings in manufacturing costs and reliability of operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cross-sectional view, taken in a plane on the rotor axis of a motor of the invention;
[0010] FIG. 2 is a diagram of the electrical control circuit that operates the motor;
[0011] FIG. 3 is a computer simulation of the magnetic field induced in the stator by current flowing to opposed poles of one phase of the stator coils and the permanent magnets of the rotor;
[0012] FIG. 4 is a computer simulation similar to FIG. 3 of the magnetic field induced in the stator by the permanent magnets of the rotor without electrical energization of stator coils;
[0013] FIG. 5 is a graph schematically showing stator coil feedback and control signals existing in operation of the motor and control circuit; and
[0014] FIG. 6 is a graph showing the torque developed on the rotor when one phase of the field coils is energized and when it is not energized.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] A system embodying the invention comprises an electrical motor 11 ( FIG. 1 ) operated by an electronic control circuit 12 ( FIG. 2 ). The illustrated motor 11 is a brushless permanent magnet type operating on direct current (DC). In the illustrated case, the motor 11 has a permanent magnet rotor 13 with four magnetic poles, 16 , 17 , and a stator 18 with four field poles 21 , 22 . The four rotor permanent magnets or poles 16 , 17 are bonded to a ferromagnetic round tube 26 suitably supported for rotation about a central axis 27 by a bearing such as a unit bearing known in the art. The rotor magnets 16 , 17 are oriented with their north and south poles alternating circumferentially about the axis 27 .
[0016] Diametrically opposite pairs of stator poles 21 or 22 are electrically wound and interconnected in a manner that when simultaneously energized with direct current, they produce magnetic fields oriented in the same direction. That is, at the inside diameter of the stator 18 when one pole 21 is North, the opposite pole 21 is also North. For purposes of explanation, one pair of opposed stator field coils are referred to as Phase 1 and the other pair are referred to as Phase 2 . Referring to FIG. 2 , a connector 31 is provided to receive command signals associated with a machine or appliance on which the motor 11 is installed. For example, the motor 11 can be used to drive an air circulating fan in a commercial refrigeration cabinet and the command signals can be related to the desired time and/or speed at which the motor is operated.
[0017] The circuit 12 includes a power supply generally bounded by the broken line 32 . Nominal 120 volt AC voltage is supplied to a connector 33 . A bridge rectifier 34 produces a nominal 160 volt supply on a positive line or “plus rail” 36 . Line 37 represents a “minus rail” or ground. Local or subcircuits 38 , 39 produce control voltages for the circuit 12 . The power supply subcircuit 39 supplies current to a microcontroller 40 through a line 41 . Current is supplied from the power supply 32 to the motor stator windings, designated 42 , 43 through a “high side” MOSFET power transistor or switch 46 and alternately through one of a pair of “low side” MOSFET switches 47 , 48 . One of the alternate low side MOSFET transistors 47 controls current in one set of field coils 42 arbitrarily labeled Phase 1 and the other MOSFET switch 48 controls current through the other stator field coils or windings 43 , arbitrarily called Phase 2 . The field windings or coils 42 are connected across solder pads or terminals 51 , 52 while, similarly, the other field windings or coils 43 of Phase 2 are connected across solder pads or terminals 53 , 54 . A driver 56 interfaces, via line 61 , between the microcontroller 40 and high side MOSFET or switch 46 and separate operational amplifiers 57 , 58 interface between the microcontroller 40 and an associated low side MOSFET power transistor or switch 47 , 48 through the lines 62 , 63 , respectively.
[0018] A study of the circuit 12 shows that the microcontroller or microprocessor 40 is arranged to selectively control current delivery to the stator field coils 42 , 43 . Feedback lines 66 , 67 allow the microcontroller 40 to monitor the back EMF produced in the respective stator coils 42 , 43 . The microcontroller 40 is programmed with a routine for starting the motor 11 and then a routine for operating it at a desired speed. As mentioned, the term Phase 1 is associated with one set of opposed stator poles 21 and the term Phase 2 is associated with the other set of poles 22 .
[0019] The poles 21 , 22 of each Phase 1 and 2 are symmetrical with one another and are such they are physically displaced from the poles of the other phase by 90°. The illustrated stator pole geometry is characterized by an air gap that varies circumferentially of the rotor, i.e. in an angular direction with reference to the axis 27 across the face of a pole 21 , 22 . This geometry produces two stable rotor positions slightly but distinctly displaced from one another corresponding to whether or not a set of opposed poles of a phase is electrically energized. The microcontroller 40 uses this phenomena to reliably start the motor in a consistent direction. In a first step in the starting sequence, the microcontroller 40 energizes a pair of poles, say those of Phase 1 . Thereafter, the microcontroller 40 de-energizes this pair as well as the other pair of poles (Phase 2 ). As indicated in FIG. 6 , the stator will tend to align with the energized phase poles where the torque is 0, i.e. −3° from a reference point where 0 is taken as the nominal geometric center of the opposed poles. The microcontroller 40 then re-energizes the pole coils (Phase 1 ) while Phase 2 remains de-energized. The rotor shifts from the energized Phase 1 angular rest position of 0 torque to a rest or stable position of 0 torque indicated at −5°. This position sets the stage for energization of the Phase 2 coils 43 . The microcontroller 40 then energizes the Phase 2 coils which rotate the rotor in a consistent known direction since the rotor 13 is off center of the Phase 1 coils consistently to the same direction at start-up as a result of the alignment step. Since the Phase 2 coils are displaced 90° from the Phase 1 coils, the rotor 13 , once it moves off of alignment with the Phase 1 coils, is out of a potential dead spot that exists when centered on the neutral or zero torque position of Phase 1 and, likewise, not being in this neutral position is not capable of rotation in an unwanted direction. The microcontroller 40 energizes the Phase 2 coils 43 to start rotation of the rotor 13 . Thereafter, the microcontroller 40 alternately energizes Phase 1 and Phase 2 coils to maintain rotation of the rotor.
[0020] Reference is made to FIG. 5 . The microcontroller 40 operates with the following strategy. Coils of only one phase, Phase 1 or Phase 2 , are energized at one time. When the back EMF, as signaled to the microcontroller 40 through one of the lines 66 , 67 of the coils 42 , 43 of a phase not energized reaches 0 that phase is energized by the microcontroller through the line 63 or 62 activating the associated MOSFET transistor 48 or 47 .
[0021] The coils of an energized phase are de-energized by the microcontroller 40 before the rotor turns 90° from when it is energized. The position of the rotor 13 after a phase is energized is calculated by the microcontroller 40 by integrating the back EMF signal, which signal is proportional to rotor speed, of the non-energized phase. The microcontroller 40 determines how long an energized set of stator coils remains turned on as a portion of a one-quarter revolution of the rotor (e.g. represented as a set point limiting the integral of the back EMF so that power is always extinguished before full 90° of rotation) to apply enough average power over an extended time so that the motor will run at a desired speed. The microcontroller can measure speed, for example, by measuring the time between instants when the back EMF goes to 0 at the same or alternate phases.
[0022] The duration of the angle of rotation that current is applied to the individual stator coils by the microcontroller 40 can be increased to increase the average speed, or reduced to lower the average speed. The microcontroller is preferably programmed to limit the rate of change of the time power is applied to minimize over or under shoot.
[0023] Current to either phase is extinguished by the microcontroller 40 at the appropriate time, this being determined by calculating the angular position of the rotor, by shutting off the high side MOSFET drive transistor 46 . This allows the field energy to dissipate in the respective stator coil 42 , 43 through a freewheeling diode 71 .
[0024] The microcontroller 40 can be programmed to detect locked rotor conditions and when such a condition exists the microcontroller places the motor 11 in a low power mode while periodically trying to start the motor. A thermistor 76 , appropriately positioned relative to the motor 11 can be provided to work with a subroutine in the microprocessor program to detect excessive temperature and place the motor in a low power mode where it will start and run periodically but will not continue to run unless the excessive load or abnormal condition is removed.
[0025] It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | A brushless DC motor operated by a microcontroller has a unique pole construction that enables it to reliably start and operate as a unipolar device so that a reduced number of electronic power switches can be used to reduce cost and complexity. The microcontroller calculated rotor position to eliminate the need for a separate sensor and thereby further reduce manufacturing cost. | 7 |
FIELD OF THE INVENTION
The present invention relates generally to projection television sets, and more particularly to optical unit brackets designed for attachment to projection television sets and projection television set enclosures incorporating the brackets.
BACKGROUND OF THE INVENTION
Projection television sets are a popular alternative to picture tube television sets, as they provide relatively large viewable screens that cannot be efficiently produced using conventional picture tubes. Projection television sets typically include an enclosure with an optical unit, a mirror, and electronic components for receiving and projecting an image onto a screen assembly mounted on the front of the enclosure.
A current, typical projection television set 100 is shown in FIGS. 1A-1C. Turning to FIG. 1A, the components of the projection television set 100 are illustrated. The projection television set 100 has an optical unit 10 that generally includes a set of projection units 20 R, 20 G, and 20 B. Each projection unit projects an image, generally of a single color of light (red, green, or blue), onto the mirror M in the enclosure (not shown), which focuses the image onto an inside surface of the screen S. Each projection unit 20 R, 20 G, 20 B includes a cathode ray tube (CRT) 22 R, 22 G, 22 B, a projection lens assembly 45 R, 45 G, 45 B, and a spacer 28 R, 28 G, 28 B interposed between each respective CRT and projection lens assembly. The projection units 20 R, 20 G, 20 B are mounted to a bracket 50 . The bracket 50 is attached to a pair of enclosure mounting brackets 55 a and 55 b that hold the bracket 50 in place within the enclosure (not shown). Attachment elements 57 a , 57 b , which may be, e.g., screws or some other anchoring elements, secure the bracket 50 to the mounting brackets 55 a , 55 b.
FIG. 1B shows a side cut-away view of a current projection television set 100 having an enclosure 105 to contain the components previously described. The enclosure 105 is typically divided by an internal wall 112 into two compartments, an upper compartment 114 and a lower compartment 116 . The internal wall 112 tightly seals the upper compartment 114 from the lower compartment 116 to protect the inside of the upper compartment 114 from dust and other foreign materials. The optical unit 10 is typically mounted in the lower compartment 116 , while the mirror M and screen S are mounted in the upper compartment 112 . Furthermore, the optical unit 10 typically extends from the lower compartment 116 into the upper compartment through the internal wall 112 . The lower compartment 116 generally includes one or more sets of ventilation holes 118 to exhaust heat radiating from the optical unit 10 and any other components, such as, e.g., printed wiring boards (not shown) that may be located in the lower compartment 116 .
To properly function, the projection units 20 R, 20 G, 20 B of the optical unit 10 must be aimed at the mirror M along a predetermined, optimal angle. Consequently, mounting bracket 55 is configured to hold the bracket 50 in place within the enclosure 105 at a predetermined angle. The enclosure mounting brackets 55 a and 55 b hold the bracket 50 at an angular orientation substantially equal to the optimal angle of operation of the projection units 20 R, 20 G, 20 B, thereby enabling the proper functioning of the projection units 20 R, 20 G, 20 B. FIG. 1C is a top view of the enclosure 105 taken along line 1 C in FIG. 1 B. FIG. 1C illustrates the attachment of the mounting brackets 55 a , 55 b to the enclosure 105 , and the attachment of the bracket 50 to the mounting brackets 55 a , 55 b . Attachment elements 59 a , 59 b are used to attach the mounting brackets 55 a , 55 b to the enclosure 105 , and attachment elements 57 a , 57 b are used to attach the bracket 50 to the mounting brackets 55 a , 55 b.
The existing techniques for mounting the optical units of projection television sets have their disadvantages. The requirement for enclosure mounting brackets to secure a bracket to an enclosure results in an increase in the complexity of producing projection television sets. For example, construction, assembly, and attachment of the optic units to the bracket and further to the enclosure mounting brackets tends to be cumbersome and, thus, labor intensive. In addition, as previously discussed, the enclosure mounting brackets must be set at the proper angle in each individual projection television set in order to ensure that the optical units are aimed in the proper direction. The need to ensure that the enclosure mounting brackets are attached to each individual enclosure at the proper angle introduces variables, such as tolerance stacking, into the production of each individual set. As a result, the possibility of a defectively produced projection television set due to an improperly attached enclosure mounting bracket is increased. Therefore, it would be desirable to provide for a more efficient and reliable means for properly mounting the optical units to the enclosures, and apparatuses for accomplishing those means.
SUMMARY OF THE INVENTION
The present invention is directed to an improved projection television set enclosure that includes side panels and an optical unit bracket attached to the side panels without the need for the enclosure mounting brackets currently utilized by those skilled in the art. In one embodiment, a projection television set is provided that comprises an enclosure, a screen, a mirror, and an optical unit that includes a plurality of projection assemblies and an optical unit bracket. The enclosure includes an upper compartment to house the screen and mirror. The enclosure also includes a lower compartment, attached to the upper compartment, that has a front panel, a rear panel, and a plurality of side panels. At least two of the side panels of the lower compartment each have an angled top surface to which the optical unit bracket is attached. The optical unit bracket may be attached to the side panels using attachment elements, such as, e.g., screws and the like. Preferably, the angled top surface of each side panel is oriented to point the optical unit at the mirror along a predetermined angle when the optical unit bracket is affixed to the angled top surface.
The optical unit bracket of this embodiment of the present invention includes a first end and a second end, each end having a horizontal extension and a vertical wall adjacent the horizontal extension. The horizontal extension is placed on top of the angled top surface of a side panel and the vertical wall is placed adjacent the side wall. Preferably, the horizontal extension and the vertical wall are located at an approximately ninety degree angle relative to each other. The vertical wall may also include a plurality of openings through which attachment elements are inserted to affix the bracket to the side wall.
In another embodiment, a projection television set is provided that includes a screen, a mirror, an enclosure, and an optical unit comprising a plurality of projection assemblies and an optical unit bracket. The enclosure includes an upper compartment to house the mirror and screen, and a lower compartment attached to the upper compartment. The lower compartment includes a front panel, a rear panel, and a plurality of side panels. At least two of the side panels of the lower compartment have angled openings through which the optical unit bracket is inserted and secured. The openings are angled to aim the optical unit towards the mirror along a predetermined angle. Preferably, the optical unit bracket has a first end and a second end, with each end being substantially the same size and shape as an angled opening on a side panel such that, once inserted into the openings, the optical unit bracket is fixed to the side panels. Additionally, an adhesive may be placed around the circumference of the first and second ends of the optical unit bracket to further ensure that the optical unit bracket is secured to the side panels.
In another embodiment, rather than having either angled openings or angled top surfaces, the side panels of the lower compartment of an enclosure of the present invention have a bracket mounting member attached thereto. The bracket mounting member preferably includes an elongate body with a top surface, a bottom surface, and first and second ends. The bracket mounting member also preferably includes a notch extending between the first and second ends and along the top surface of its elongate body. The notch of the bracket mounting member receives and engages a detent that is located on the underside of one embodiment of the optical unit bracket. In this embodiment, the optical unit bracket includes detents on its first and second ends, on the underside of the bracket, extending along the width of the bracket.
Other objects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1A illustrates a schematic representation of the components of a current, typical projection television set.
FIG. 1B is a side view of a current, typical projection television set showing an enclosure of the set with the components therein.
FIG. 1C is a top view of a cut-away of the projection television set illustrated in FIGS. 1A and 1B showing the attachment of an optical unit to the enclosure using mounting brackets.
FIG. 2A is an illustration of an embodiment of the present invention showing a bracket attached directly to a lower compartment, having angled top surfaces, of a projection television set enclosure.
FIG. 2B is an exploded view of the embodiment of the present invention shown in FIG. 2 A.
FIG. 3 is illustration of an embodiment of the present invention showing an enclosure having a lower compartment with angled top surfaces and a bracket attached directly to the angled top surfaces.
FIG. 4 is an illustration of a bracket configured for direct attachment to a lower compartment, having angled top surfaces, of an enclosure.
FIG. 5A is an illustration of an embodiment of the present invention showing a lower compartment of an enclosure wherein the lower compartment has an opening on each side panel for insertion and attachment of an optical unit thereto.
FIG. 5B is an illustration of the lower compartment of an enclosure shown in FIG. 5A having a bracket of an optical unit affixed to each opening on each side panel.
FIG. 5C is a side view of the lower compartment shown in FIG. 5 A.
FIG. 6 is an enclosure that incorporates the lower compartment shown in FIG. 5 A.
FIG. 7 is a bracket of an optical unit configured for attachment to the openings of the side panels of the lower compartment shown in FIG. 5 A.
FIG. 8A is an end view of another lower compartment of an enclosure of the present invention having bracket mounting members located on each side panel of the lower compartment to fixedly engage a bracket of an optical unit.
FIG. 8B is an end view of the lower compartment shown in FIG. 8A having a bracket fixedly engaged to the bracket mounting members of the side panels of the lower compartment.
FIG. 9A is an end view of a bracket having detents configured for engaging the bracket mounting members of the side panels of the lower compartment shown in FIG. 8 A.
FIG. 9B is a view of the underside of a bracket having detents for engaging the bracket mounting members of the side panels of the lower compartment shown in FIG. 8 A.
FIG. 10 is a top view of a bracket mounting member of the side panels of the lower compartment shown in FIG. 8A, illustrating a notch on the bracket mounting member configured to receive and engage the detents of the bracket illustrated in FIGS. 9A and 9B.
FIG. 11 is a side view of an enclosure of the present invention that incorporates the lower compartment shown in FIG. 8 A.
DETAILED DESCRIPTION
Turning to FIG. 2A, a lower compartment 216 of an enclosure 205 of a projection television set 200 of the present invention is illustrated. The lower compartment 216 has a front panel (not shown), a rear panel (not shown), and a plurality of side panels 230 a , 230 b . Panels 232 a , 232 b attach to the side panels 230 a , 230 b to form inner walls separating the space within the lower compartment 216 from the space within the upper compartment 214 (see FIG. 3) of the enclosure 205 . In the illustrated embodiment, panel 232 a is disposed between the front panel (not shown) and optical unit bracket 250 while panel 232 b is disposed between the rear panel (not shown) and bracket 250 . The side panels 230 a , 230 b each include an angled top surface 235 a , 235 b respectively.
Optical unit bracket 250 is directly attachable to the side panels 230 a , 230 b and to the angled top surfaces 235 a , 235 b of side panels 230 a , 230 b . Optical unit bracket 250 forms part of an optical unit 210 that further includes a plurality of projection units 220 . Each projection unit 220 includes a cathode ray tube (CRT) 222 , a projection lens 245 , and a spacer 228 mounted between each CRT 222 and projection lens 245 . The optical unit 210 is attached to the optical unit bracket 250 . Once the optical unit bracket 250 is attached to the side panels 230 a , 230 b and the angled top surfaces 235 a , 235 b of the side panels 230 a , 230 b , the optical unit 210 is secured in a fixed, angled position. Preferably, the angle in which the optical unit 210 is fixed corresponds to an angle that optimizes the operation of the optical unit 210 . For example, the angle is preferably one that allows the optical unit 210 to accurately and efficiently project light onto a mirror M (FIG. 3) located within the upper compartment 214 (FIG. 3) of the enclosure 205 (FIG. 3 ). The presence of the angled top surfaces 235 a , 235 b on the side panels 230 a , 230 b eliminates the need for additional mounting bracket hardware to maintain the optical unit 210 in an optimally angled position, unlike conventional enclosures such as the enclosure 105 illustrated in FIGS. 1B and 1C.
FIG. 2B illustrates an exploded view of lower compartment 216 . As seen in FIG. 2B, a plurality of attachment elements 252 may be used to secure the optical unit bracket 250 of the optical unit 210 directly to the side panels 230 a , 230 b . The attachment elements 252 may be screws, nails, or the like. Although the illustrated embodiment utilizes two attachment elements 252 to attach each side of the optical unit bracket 250 to the side panels 230 a , 230 b , any number of attachment elements 252 may be used to secure the optical unit bracket 250 to the side panels 230 a , 230 b . Alternatively, the optical unit bracket 250 is attached to the side panels 230 a , 230 b , and to the angled top surfaces 235 a , 235 b of the side panels 230 a , 230 b , using an adhesive.
FIG. 3 illustrates a side view of one embodiment of an enclosure 205 of a projection television set 200 of the present invention. Lower compartment 216 is shown with the optical unit 210 attached thereto. An upper compartment 214 is attached to the top surface of the lower compartment 216 to form the enclosure 205 . Housed within the upper compartment 214 is a mirror M and a screen S. As previously discussed, the optical unit bracket 250 of the optical unit 210 is fixedly secured to the side panels 230 a , 230 b (identified collectively as side panel 230 in FIG. 3) of the lower compartment 216 using a suitable attachment means, such as, e.g., attachment elements 252 . When attached to the side panels 230 a , 230 b having angled top surfaces 235 a , 235 b , the optical unit bracket 250 is fixed in an angled position that enables the optical unit 210 to project light onto the mirror M. Preferably, the angled top surfaces 235 a , 235 b form an angle that enables the optical unit 210 , once the optical unit bracket 250 is fixed to the side panels 230 a , 230 b , to optimally and efficiently project light onto the mirror M.
Turning to FIG. 4, optical unit bracket 250 of optical unit 210 is illustrated. Optical unit bracket 250 is adapted for use with enclosure 205 in that optical unit bracket 250 includes horizontal side extensions 256 a , 256 b and vertical side walls 258 a , 258 b that are configured to allow for the attachment of the optical unit bracket 250 to the side panels 230 a , 230 b without requiring additional mounting bracket hardware. The horizontal side extensions 256 a , 256 b and the vertical side walls 258 a , 258 b are located at the first and second end of the optical unit bracket 250 . Each horizontal side extension 256 a , 256 b is preferably oriented at approximately a 90 degree angle to vertical side wall 258 a , 258 b respectively. When attached to side panels 230 a , 230 b , the horizontal side extensions 256 a , 256 b are placed on top of the angled top surfaces 235 a , 235 b . Placement of the horizontal side extensions 256 a , 256 b atop the angled top surfaces 235 a , 235 b allows the optical unit bracket 250 to be supported by the side panels 230 a , 230 b without requiring additional mounting brackets. The weight of the optical unit bracket 250 forces the horizontal side extensions 256 a , 256 b to press against the angled top surfaces 235 a , 235 b , thereby contributing to the secure attachment of the optical unit bracket 250 to the side panels 230 a , 230 b . The vertical side walls 258 a , 258 b , in turn, are securably attached to the side panels 230 a , 230 b using a suitable attachment element, such as a screw, a nail, or the like. As seen in FIG. 4, a plurality of attachment openings 254 are provided on each vertical side wall 258 a , 258 b to allow for an attachment element to be inserted therethrough to facilitate the attachment of optical unit bracket 250 to the side panels 230 a , 230 b . Additionally, a plurality of projection openings 260 are provided to which the projection units 220 are attached to the bracket 250 . The projection openings 260 allow light to be projected from the projection units 220 through the optical unit bracket 250 and subsequently to mirror M.
FIG. 5A illustrates another embodiment of the present invention. Shown in FIG. 5A is a lower compartment 316 of a projection television enclosure 305 (FIG. 6 ). The lower compartment 316 includes a front panel 302 , a rear panel 304 , and a plurality of side panels 330 a , 330 b . Two side panels 330 a , 330 b are illustrated, but the lower compartment 316 may include additional side panels in order to form, in conjunction with the upper compartment 314 (FIG. 6) an enclosure that is shaped other than as a rectangle or a square, such as, e.g., a trapezoidal enclosure, an irregularly shaped enclosure, or the like. The side panels 330 a , 330 b include openings 340 a , 340 b , respectively. An optical unit bracket 350 of an optical unit 310 (FIG. 6) is inserted within openings 340 a and 340 b.
Turning to FIG. 5A, the lower compartment 316 is illustrated with an optical unit bracket 350 of an optical unit 310 (FIG. 6) secured within openings 340 a , 340 b of side panels 330 a , 330 b . Preferably, openings 340 a , 340 b are angled such that when optical unit 310 is secured therein, optical unit 310 is oriented to optimally project light onto a mirror M (FIG. 6) located in the upper compartment 314 (FIG. 6 ). Further, openings 340 a , 340 b preferably conform to the size of optical unit bracket 350 such that when the optical unit bracket 350 is inserted through the openings 340 a , 340 b a secure fit is formed between the optical unit bracket 350 and the openings 340 a , 340 b . For example, the first end 355 a and the second end 355 b (FIG. 7) of optical unit bracket 350 and the openings 340 a , 340 b are preferably substantially the same size and shape. Additionally, an adhesive may be used ensure that the optical unit bracket 350 is fixed to the openings 340 a , 340 b of side panels 330 a , 330 b . For example, an adhesive may be applied around the circumference of the first end 355 a and the second end 355 b (FIG. 7) of the optical unit bracket 350 prior to insertion of the optical unit bracket 350 into the openings 340 a , 340 b . The optical unit bracket 350 is then inserted into openings 340 a , 340 b and is fixed thereto by the combination of the adhesive and the conformance of the openings 340 a , 340 b to the size of optical unit bracket 350 , and more specifically to the first end 355 a and the second end 355 b of the optical unit bracket 350 . Accordingly, the need for additional, separate mounting bracket hardware, such as, e.g., in the enclosure 105 illustrated in FIGS. 1B and 1C, is eliminated since the optical unit bracket 350 is secured directly to the side panels 330 a , 330 b of the lower compartment 316 . Also, another advantage of lower compartment 316 is that the top surface of the lower compartment 316 is substantially level. As a consequence, lower compartment 316 is stackable, which provides benefits during the manufacture of enclosure 305 . For example, the ability to stack lower compartment 316 allows a greater number of lower compartments to be stored within a warehouse or manufacturing facility pending attachment of those lower compartments to upper compartments to form enclosures.
FIG. 5B illustrates lower compartment 316 with the optical unit bracket 350 secured to the side panels 330 a , 330 b . Additionally, a panel 312 a is disposed between front panel 302 and optical unit bracket 350 and panel 312 b (FIG. 6) is disposed between rear panel 304 and bracket 350 . Together, panels 312 a and 312 b form inner walls separating the space within the lower compartment 316 from the space within the upper compartment 314 (FIG. 6) of the enclosure 305 . FIG. 5C is a side view of lower compartment 316 showing panels 312 a and 312 b disposed therein. Additionally, a side panel 330 (which corresponds to side panels 330 a and 330 b ) having an opening 340 (which corresponds to openings 340 a and 340 b ) for insertion of optical unit bracket 350 is illustrated.
FIG. 6 illustrates a side view of an embodiment of enclosure 305 of a projection television set 300 that includes lower compartment 316 and upper compartment 314 . Upper compartment 314 houses a mirror M and a screen S. Lower compartment 316 is illustrated with optical unit 310 attached thereto. Optical unit 310 includes a plurality of projection units 320 and an optical unit bracket 350 . Each projection unit 320 includes a cathode ray tube (CRT) 322 , a projection lens 345 , and a spacer 328 mounted between each CRT 322 and projection lens 345 . The optical unit 310 is attached to the optical unit bracket 350 . As previously discussed, the optical unit bracket 350 is inserted into openings 340 a and 340 b of side panels 330 a and 330 b (both identified as opening 340 of side panel 330 in FIG. 6 ). The optical unit bracket 350 is maintained within openings 340 a , 340 b since the size of openings 340 a , 340 b preferably conform substantially to the size of first end 355 a and the second end 355 b (FIG. 7) of the optical unit bracket 350 . Additionally, an adhesive may be applied around the circumference of the first end 355 a and the second end 355 b in order to further fix the optical unit bracket 350 to side panels 330 a , 330 b . Also illustrated in FIG. 6 are panels 312 a and panel 312 b that form inner walls between the space within the upper compartment 314 and the lower compartment 316 .
FIG. 7 illustrates an optical unit bracket 350 that is suitable for use with lower compartment 316 . Specifically, optical unit bracket 350 includes a first end 355 a and a second end 355 b . First end 355 a and second end 355 b are substantially the same size and shape as openings 340 a and 340 b on side panels 330 a and 330 b . When inserted into openings 340 a , 340 b , the first end 355 a and the second end 355 b form a tight fit within openings 340 a , 340 b , thereby securing optical unit bracket 350 within side panels 330 a , 330 b . Further, as previously discussed, an adhesive may be applied around the circumference of first end 355 a and second end 355 b to further ensure that the optical unit bracket 350 is fixedly secured within openings 340 a , 340 b of side panels 330 a , 330 b . Optical unit bracket 350 also includes a plurality of projection openings 360 where the projection units 320 are attached to the optical unit bracket 350 . The projection openings 360 allow light to be projected from the projection units 320 through the optical unit bracket 350 and subsequently onto mirror M.
Turning now to FIG. 8A, another embodiment of the present invention is shown. Lower compartment 416 includes a front panel 402 , a rear panel (not shown), and a plurality of side panels 430 a , 430 b . The lower compartment 416 together with an upper compartment 414 (FIG. 11) forms an enclosure 405 (FIG. 11 ). As illustrated, lower compartment 416 includes two side panels 430 a , 430 b . It should be recognized, however, that lower compartment 416 may include a greater number of side panels if the desired shape of the enclosure is a shape other than a square or rectangle.
Located on each side panel 430 a , 430 b is a bracket mounting member 470 a , 470 b . The bracket mounting member 470 a , 470 b is oriented at a downward angle, i.e., the end of each bracket mounting member 470 a , 470 b facing the rear panel (not shown) is disposed at a lower position on the side panel 430 a , 430 b than the end of each bracket mounting member 470 a , 470 b that faces the front panel 402 . As seen in FIG. 10, each bracket mounting member 470 (bracket mounting members 470 a and 470 b are collectively identified in FIG. 10 as 470 ; further references to a bracket mounting member 470 are intended to encompass both bracket mounting members 470 a and 470 b as such discussion will generally be applicable to both) includes a notch 475 that extends lengthwise along the bracket mounting member 470 . The notch 475 accepts and engages detents 455 a , 455 b located distally and on the underside of an optical unit bracket 450 of an optical unit 410 (FIG. 1 ).
FIG. 9A shows an end view of an optical unit bracket 450 having detents 455 a , 455 b designed for placement into the notch 475 on bracket mounting members 470 a , 470 b respectively. FIG. 9B shows an underside view of the optical unit bracket 450 . As seen in FIG. 9B, detents 455 a , 455 b extend along the width of the optical unit bracket 450 . Projection openings 460 to which the projection assemblies 420 are attached are also illustrated. Turning back to FIG. 10, the notch 475 on each bracket mounting member 470 is approximately equal in length to the detents 455 a , 455 b that extend along the optical unit bracket 450 . Consequently, when the optical unit bracket 450 is placed on the bracket mounting member 470 , and specifically when detents 455 a , 455 b are placed within the notch 475 on bracket mounting members 470 a , 470 b , the optical unit bracket 450 is fixedly engaged by the bracket mounting members 470 a , 470 b without the need for attachment elements such as screws, nails, or the like. To further affix the optical unit bracket 450 to the bracket mounting members 470 a , 470 b , an adhesive may be placed within the notch 475 of each bracket mounting member 470 a , 470 b prior to the placement of the detents 455 a , 455 b of the optical unit bracket 450 within the notch 475 of each bracket mounting member 470 a , 470 b.
Turning to FIG. 8B, FIG. 8B illustrates an optical unit bracket 450 fixedly engaged to bracket mounting members 470 a , 470 b and, therefore, attached to side panels 430 a , 430 b of lower compartment 416 . As previously discussed, bracket mounting members 470 a , 470 b are attached to side panels 430 a , 430 b at a downward angle, i.e., the end of the bracket mounting members 470 a , 470 b facing the front panel 402 is higher relative to the end of the bracket mounting members 470 a , 470 b facing the rear panel (not shown). Consequently, when fixed or engaged to bracket mounting members 470 a , 470 b , optical unit bracket 450 is likewise oriented at a downward angle when viewed from the front panel 402 to the rear panel (not shown). Furthermore, the angle at which the bracket mounting members 470 a , 470 b , and the optical unit bracket 450 , is oriented is substantially equivalent to an angle that optimizes the projection of light from the projection units 420 (FIG. 11) of the optical unit 410 . For example, the optical unit bracket 450 is preferably aimed at the mirror M when it is engaged to the bracket mounting members 470 a , 470 b.
The bracket mounting members 470 a , 470 b may be constructed of injection molded plastic, vacuum formed plastic, particle board, other wood-based materials, or the like. In one embodiment, the bracket mounting members 470 a , 470 b are affixed to the side panels 430 a , 430 b after the side panels 430 a , 430 b are initially formed. For this embodiment, the bracket mounting members 470 a , 470 b may be secured to the side panels 430 a , 430 b using an adhesive, screws, nails, or the like. In another embodiment, the bracket mounting members 470 a , 470 b form a unitary part of the side panels 430 a , 430 b . For example, when the side panels 430 a , 430 b are formed of injected molded plastic or vacuum formed plastic, the side panels 430 a , 430 b may be formed having bracket mounting members 470 a , 470 b . With this embodiment, the step of separately attaching bracket mounting members 470 a , 470 b to side panels 430 a , 430 b after the initial formation of side panels 430 a , 430 b is eliminated.
FIG. 11 illustrates a side view of an enclosure 405 for a projection television set 400 that includes upper compartment 414 and lower compartment 416 . As with the previously discussed embodiments of projection television set enclosures, the upper compartment 414 of enclosure 405 houses a mirror M and a screen S. Lower compartment 416 is shown with optical unit 410 attached thereto. Optical unit 410 includes a plurality of projection units 420 and bracket 450 . Each projection unit 420 includes a cathode ray tube (CRT) 422 , a projection lens 445 , and a spacer 428 mounted between each CRT 422 and projection lens 445 . The optical unit 410 is attached to optical unit bracket 450 . As previously discussed, optical unit bracket 450 is fixedly engaged to bracket mounting members 460 a , 460 b of side panels 430 a , 430 b (both identified as bracket mounting member 460 of side panel 430 in FIG. 11 ). Once engaged to the bracket mounting members 460 a , 460 b , the optical unit bracket 450 , and therefore the optical unit 410 , is angled to optimally project light onto mirror M. Also illustrated in FIG. 1I are panels 412 a and panel 412 b that form inner walls between the spaces within upper compartment 414 and lower compartment 416 . Panel 412 a is located between optical unit bracket 450 and front panel 402 whereas panel 412 b is disposed between optical unit bracket 450 and rear panel 404 .
The particular examples set forth herein are instructional and should not be interpreted as limitations on the applications to which those of ordinary skill are able to apply this device. Modifications and other uses are available to those skilled in the art which are encompassed within the spirit of the invention as defined by the scope of the following claims. | An enclosure for a projection television set is provided that includes an upper compartment to house a mirror and a screen, and a lower compartment attached to the upper compartment. The lower compartment preferably includes a front panel, a rear panel, and a plurality of side panels wherein at least two side panels have an attachment region for a bracket of an optical unit. The attachment region may be angled surfaces designed to aim the optical unit toward the mirror of the projection television set. The attachment region may also be angled openings for insertion of first and second ends of the bracket of the optical unit therein, the angled openings configured to aim the optical unit toward the mirror. Alternatively, the attachment region may include a member having an elongate body with a top surface, a bottom surface, a first end, a second end, and a notch extending between the ends along the top surface of the elongate body, wherein the notch engages the bracket of the optical unit. In another embodiment, a bracket for an optical unit of a projection television set is provided that includes first and second ends having a horizontal extension oriented at approximately 90 degrees to a vertical wall. The horizontal extension rests atop an angled top surface of a side panel of a lower compartment of an enclosure of the present invention, while the vertical wall attaches to the side panel, thereby eliminating the need for additional mounting bracket hardware. | 7 |
RELATED APPLICATIONS
This is a continuation application of Ser. No. 08/501,206, filed Jul. 11, 1995, now U.S. Pat. No. 5,556,482, which is a application is a continuation-in-part of application Ser. No. 08/433,677 filed May 4, 1995 which is a continuation-in-part of application Ser. No. 07/983,257 filed Nov. 30, 1992, now U.S. Pat. No. 5,417,877, which in turn a continuation-in-part of application Ser. No. 07/647,487 filed Jan. 25, 1991, now abandoned.
FIELD OF THE INVENTION
The present invention relates to improved organic compositions containing organic polar solvents and basic amines which are useful as stripping agents in removing polymeric organic substances, such as photoresist from metallic substrates. More particularly, the invention provides a novel inhibition system which prevents corrosion and dulling of the metallic surface.
BACKGROUND OF THE INVENTION
During manufacture of semi-conductors and semi-conductor microcircuits, it is frequently necessary to coat the materials from which the semi-conductors and microcircuits are manufactured with a polymeric organic substance which is generally a photoresist, i.e. a substance which forms an etch resist upon exposure to light. Subsequently, the polymeric organic substance must be removed from the surface of the organic substrate which is typically a silicon dioxide coated silicon wafer and may also contain metallic microcircuitry, such as aluminum, on the surface. Therefore, there is a need for improved stripping compositions which will remove the polymeric organic substance from the coated inorganic substrate without corroding, dissolving or dulling the surface of the metallic circuitry or chemically altering the inorganic substrate.
Organic stripping agents comprising aromatic solvents and basic amines are known for removing organic substances from metallic inorganic substrates. While these stripping agents are effective in removing the polymeric substances, they also have the tendency, especially in the presence of water to corrode the metal or metal alloy comprised, for example of copper, silicon aluminum and/or titanium. It has been proposed in some organic stripping compositions to use hydrogen fluoride to reduce the rate of metal corrosion. However, hydrogen fluoride is harmful to the environment, attacks titanium and creates disposal problems.
Other known inhibitors such as β-naphthol, glucose, hydroquinone resorcinol and benzotriazole have been found to be ineffective to inhibit the pitting of copper when used with a stripping composition comprising organic polar solvents and basic amines.
U.S. Pat. No. 4,617,251 to Sizensky which is herein incorporated by reference, discloses a stripping composition in which the inhibitors of the present invention can be utilized.
British application No. 8428587 discloses stripping compositions comprising amides and amines which can be used with the inhibitors of the invention.
U.S. Pat. No. 5,308,745 to Schwartzkopf discloses an alkaline containing photoresist stripping composition which utilizes weak acids as corrosion inhibitors in an amount to neutralize about 19 to 75% of the amine present.
U.S. Pat. Nos. 5,334,332 and 5,279,771 to Lee disclose a composition containing hydroxylamine, an alkanolamine and a chelating agent which is added to the mixture.
It is an object of this invention to provide improved organic stripping compositions which cleanly and efficiently remove organic photoresist materials and/or sidewall polymers from aluminized or metal alloyed inorganic substrates, particularly aluminized or metal alloyed silicon dioxide, without causing substantial etching of the inorganic substrate or corrosion and dulling of the metallic circuitry exposed or on the surface of the inorganic substrate, even after repeated use at elevated temperatures.
It is also an object of this invention to provide a method for removing polymeric organic substances and/or sidewall polymers from the surfaces of aluminized or metal alloyed inorganic substrates, particularly aluminized silicon dioxide, without causing etching of the inorganic substrate or corrosion and dulling of the metallic circuitry exposed or on the surface of the inorganic substrate.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a stripping composition comprising about 50 to 98% by weight of an organic polar solvents and basic amines in combination with an inhibiting system which is effective in aqueous or non-aqueous stripping compositions.
The inhibitors which are used in connection with the present invention are those which are formed by the reaction of an amine containing polar solvent and/or a basic amine and a compound selected from the group of the formula consisting of: ##STR1## wherein X represents C, N, or S,
Y represents C, N
R represents --OH, --NR"R", --SR", --NO, NO 2 or ##STR2## z is O, or 1 R' represents --OH, --NR"R", --SR", --NO, NO 2 or ##STR3## wherein R" represents H or lower alkyl, and
R'" represents lower alkyl or lower alkoxy,
A and B each represent --OH and G represents H, --OH, CO 2 R", lower alkyl or halo.
Among the preferred compounds of Formula I utilized in forming the inhibitor system in the invention are
2,3-dihydroxybenzoic acid,
pyrogallol,
8-amino-4H- chromene,
8-hydroxyquinoline,
7-amino 2,3-benzofuran,
1-hydroxy-8-dialkylaminonaphthalene
1-hydroxy-8-dimethylaminonapthalene,
8-hydroxy-4H-1-benzothiopyran,
8-hydroxy-4H-1-benzothiofuran,
8-methylthiochroman,
8-ditertbutylamino chromene,
1-tertbutoxy-8-nitronaphthalene,
8-alkylketoquinoline,
8-sulfhydrylquinoline, anthranilic acid
8-nitrosoquinoline,
2-hydroxy benzene sulfonamide,
catechol, and
related ortho-dihydroxy isomers
The inhibitors of the invention are formed in situ by admixing a basic amine such as an alkanolamine or a hydroxylamine compound with one of the compounds of formula I, preferably a monocyclic compound. Most preferably, the compound is catechol or pyrogallol.
It has been found that when the monocyclic hydroxylated compound is mixed with an alkanolamine there is immediately formed the phenolate anion which is an oxygen absorbing and chelating agent. That is, if catechol is added to monoethanolamine in an amount less than that which neutralizes less than 19% there is primarily formed a monophenolate salt which is ortho hydroxy monoethanolammonium phenolate that is the inhibitor when placed into a composition containing hydroxyl amine, an alkanolamine and water. It is understood that the phenolate salt can be prepared separately and added to the stripping composition.
Therefore and surprisingly the order of mixing ingredients becomes critical since the phenolate salts formed with alkanol amines, especially monoethanolamine, exhibit better anticorrosive effects than when combined with hydroxylamine compounds or a mixture of other alkanolamines and hydroxylamine compounds either in an aqueous or non-aqueous form.
The inhibitor functions in a non-aqueous stripping composition to provide protection of substrates, which have been sensitized toward corrosion by exposure to a chlorine or fluorine plasma, from dissolved oxygen or amines. In an aqueous stripping composition there is protection of the metal substrate against corrosion caused by dissolved oxygen, hydroxyl ions and/or the amines.
The stripping compositions of this invention suitably comprises a mixture of a polar solvent selected from the group consisting of monoethanolamine, diethanolamine, isopropanolamine or an amide compound of the formula: ##STR4## and mixture thereof, wherein R is selected from the group consisting of hydrogen, lower alkyl and phenyl; R 1 and R 2 are selected from the group consisting of hydrogen and lower alkyl; and R and R 1 together with the keto and nitrogen group to which they are attached form a five or six membered ring, a pyrrolidone compound, alkylsulfoxide, and the like, (b) basic amine compounds of the invention include those amines which are also named as polar solvents and compounds of the formula: ##STR5## and mixtures thereof, wherein R 3 is selected from the group consisting of --OH, --C 2 H 5 , --C 2 H 4 OH, phenyl and CH 2 CH(OH)CH 3 , R 4 is selected from the group consisting of hydrogen, alkanol and phenyl, and R 5 is selected from the group consisting of hydrogen, lower alkyl, alkanol and --C 2 H 4 OH, and (c) about 2 to 7% by weight and a non-neutralizing amount of the reaction product of a compound of Formula I and a basic amine which forms a phenolate salt. Higher amounts of the compounds of Formula I causes a reduction in the solvency power and aggressiveness of the amines utilized and therefore reduction in stripping efficacy.
If desired, the stripping composition can comprise up to 50% by weight of water, more preferably up to about 20%. However, it is understood that the hydroxylamine is utilized as a 50% aqueous solution.
Also in accordance with this invention, there is provided a method for stripping a polymeric organic substance from a metallized inorganic substrate comprising contacting the polymeric organic substance with an organic stripping composition of this invention at a temperature of about 20° to about 180° C.
DETAILED DESCRIPTION OF THE INVENTION
The stripping compositions of this invention can comprise from about 50 to about 98%, preferably, from about 20 to about 50%, by weight of a polar solvent or mixture of polar solvents, a basic amine compound or mixture of amines, and about 2 to 7% by weight, preferably from about 5% of an inhibitor formed by the mixture of a compound of Formula I and an alkanolamine.
As examples of suitable amide compounds useful as polar solvents in the compositions of this invention, there may be mentioned, for example, N,N-dimethyl acetamide, N-methyl acetamide, N,N-diethyl acetamide, N,N-dipropylacetamide, N,N-dimethyl propionamide, N,N-diethyl butyramide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone and N-methyl-N-ethyl acetamide, and the like.
Other polar solvents include dimethylsulfoxide (DMSO), monoethanolamine, 2-(2-aminoethylamino)ethanol, triethanolamine, and the like.
As examples of amine compounds useful in the compositions of this invention, there may be mentioned, for example, an aqueous solution of hydroxylamine, morpholine, isopropanolamine 2-aminopicoline, bis(2-ethylhexyl)amine, monoethanolamine monopropanolamine, N-methylaminoethanol etc.
A preferred stripping composition of this invention comprises a mixture consisting of about 18% by weight of hydroxylamine, about 18% by weight of water and the reaction product of 59% by weight of monoethanolamine and 5% by weight of catechol which can be prepared in situ or separately.
The stripping compositions of this invention are especially useful and advantageous for numerous reasons among which may be mentioned the following. The stripping compositions are water miscible, non-corrosive, non-flammable and of low toxicity to humans and the environment. Because of the low ambient Vapor pressure of the non-aqueous components they evidence substantially less evaporation than prior compositions and are non-reactive and environmentally compatible. The stripping compositions may be recycled for component recovery or easily disposed of in an environmentally safe manner without the necessity for burdensome safety precautions. Likewise, a portion of the stripped coatings may be readily removed as solids and collected for easy disposal. The stripping compositions of this invention evidence higher stripping efficiency at lower temperatures for a wide variety of coatings and substrates. Moreover, the stripping compositions are easily prepared by simply mixing the components in the proper sequence at room temperature and thus require no special human or environmental safety precautions. Furthermore, the components of the stripping compositions of this invention provide synergistic stripping action and permit readily and substantially complete removal of coatings from substrates.
EXAMPLE 1
A standard corrosion solvent system was used to test a variety of inhibitors for corrosion prevention on two different metal substrates:
1) Pure 100% copper foil;
2) An Al/Cu (2%) metal alloy sputter deposited on top of a silicon substrate as bonding pads and/or line space pairs; and
3) Exposed plasma sensitized metal VIA pattern.
The standard corrosion solvent used for substrate 3 was of the following composition:
MEA--36%
DMAC--50%
H 2 O--10%
Inhibitor--4%
EXAMPLE 2
Previous tests with the following solvents were performed to assess corrosion propensity on the substrates of Example 1. Attack was assessed by a change in color of the solvent to blue or blue-green indicating formation of a stable complex of oxidized (i.e. corroded) copper. SEMS analysis was used to assess attack on substrate 2. The solvents included:
1) DMA
2) DMF
3) Tetrahydrofurfuryl alcohol (THFA)
4) N-Methylpyrrolidone (NMP)
For substrate 1, pure copper foil was exposed at ambient temperatures for 22 hours in a pyrex beaker covered with aluminum foil. A change in solvent color was observed. For substrate 2, a foil with patterned Al/Cu designs were immersed in each solvent heated to 75°-80° for 60 minutes followed by a dionized water rinse and nitrogen blow-dry. The substrates were examined by SEM for the integrity of the exposed metal alloy line space pairs.
Results
SEM observation of alloy metal attack was used to assess corrosion of substrate 2 above. The solvents included those compounds consistent with those listed above which did not undercut the substrates.
None of the solvents showed any effect at all on substrates 1 or 2 above.
EXAMPLE 3
Several amines (i.e., which are known to form stable complexes with Cu and can be strong corrosives) were tested using the same color-change indicator as above on substrate 1 above. The tests are summarized below for exposures of 22 hrs at room temperature.
______________________________________Component Color Rating* Results______________________________________DMA Clear 0 No attackMEA Light blue 2-3 Slight Cu attackHydroxylamine Light blue 2-3 Slight to moderate attackMorpholine Light-mod. blue 2-3 Slight Cu attack1-Amino-2 Propanol Moderate blue 5 Mod. Cu attackAmmonium Hydroxide Deep blue 10 Heavy attackTriethanolamine Clear 0 No attack2-(2 Aminoethoxy) Blue-green 5-6 Mod. attackEthanol3-Methoxypropylamine Green 4-5 Mod. attack2-Amino-3-Picoline Clear 0 No attack______________________________________ Scale: 0 No color change, no attack 10 Deep opaque blue, heavy attack
These studies clearly point out that the amine in a formulation, is responsible for metal corrosion, not just for Cu, but for many different metals including Al, Ti, Cu, Cr, Al/Cu, etc. This fact is also established in standard electrochemical potentials of these metals, which show a greater propensity for metal oxidation (i.e. corrosion) in an NH 3 or R-NH 2 environment.
EXAMPLE 4
The standard formulation of Example 3 was employed with a wide range of inhibitors and tested for corrosion using three different methods of determination:
1) For Cu substrates actual ICP (inductive coupled plasma) measurements of the copper extracted into the corrosive solution.
2) Microscopic examination of Cu surface before and after exposure to the test solution i.e. reference formulation plus inhibitor).
3) DF/BF microscopic examination of "pitting" corrosion on Al/Cu alloy substrates before and after exposure to test solution.
______________________________________INHIBITOR TEST DATA TestInhibitor Substrate Method Results______________________________________REF. BLANK 100% Cu (1) 124 ppm (2) Severe pitting, dull mat finish A1/Cu (2%) (3) Large increase "black spot" pitting over unexposed pad (pitting over 100% of pads)PYROGALLOL 100% Cu (1) 10.4 ppm (2) High sheen, no pitsRESORCINOL Al/Cu (2%) (3) Visual pitting on 30% of padsGLUCOSE Al/Cu (2%) -- Does not dissolve in Ref. blank8-HYDROXYQUINOLINE 100% Cu (2) High sheen, no pitting Al/Cu (2%) (3) No observable pits (<1% of pads show increase pitting over "before" subst.)(BHT) 100% Cu (1) 57 ppm (Ref.Di-t-butyl hydroxy blank = 174 ppm)toluene (2) Mod-severe blotching and substrate attack______________________________________
EXAMPLE 5
A preferred stripping composition and inhibitor system is prepared as follows:
______________________________________Ingredient Wt %______________________________________Monoethanolamine (MEA) 59.2Hydroxylamine (50% Aqueous 36.1solution)Catechol 4.7______________________________________
In a plantwise operation 592 lbs. of MEA is poured into a stainless steel blender and recirculated for 10-15 minutes through a 0.2 μm filter system.
Into a separate container of 47 lbs. of catechol is added with stirring sufficient MEA to dissolve the catechol and to form the phenolate salt. This solution is then added to the blender containing the MEA. To this solution is added 361 lbs. of a 50% aqueous solution of hydroxylamine obtained from Nissin Chemical Industry, Inc., Tokyo, Japan to form the final solution.
The identification of the phenolate anion was determined by packed column thermal conductivity GC, by H-NMR (proton nuclear magnetic resonance spectroscopy), and by I.R. (infrared) spectroscopy. | Organic stripping composition for photoresists comprising organic polar solvents and basic amines which includes an inhibitor which forms a coordination complex with a metal. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to optical devices.
Devices have been proposed in which their absorptivity for incident radiation can be controlled by the potential applied to the device. In 1973, it was proposed in UK patent No. 1 331 228 that the Pockels effect (the linear change of refractive index of some materials with field strength) could be used for modulating a light source from a laser.
Silica optical fibres as produced in recent years for optical communications have absorption minima at 1.3 and 1.55 μm and therefore there is a need for devices capable of operating at such wavelengths. (The above wavelengths are in vacuo wavelengths as are all wavelengths herein except where otherwise specifically stated.)
D S Chemla, T C Damen, D A B Miller, A C Gossard, and W Wiegmann have reported, in Appl. Phys. Lett., 42(10), pages 864-866 (1983), that the absorption of photons at room temperature in a multi-quantum well structure comprising alternate GaAs and Ga 0 .72 Al 0 .28 As layers is dependent on the electric field applied in the plane of the layers of the structure. This effect they ascribe principally to the shift of exciton resonances by the Stark effect. (An exciton is a hole in the valence band in combination with an electron in the conduction band.) They report marked dependence of absorptivity with applied potential at photon energies around 1.45 eV corresponding to a wavelength of about 0.85 μm (850 nm). They suggest that the effect could be used for high-speed optical modulators. One disadvantage of their proposal is that the application of a field in the plane of the layers can pose difficulties if such a device is to be integrated with others.
E E Mendez, G Bastard, L L Chang, L Esaki, H Morkoc, and R Fischer have reported, in Physica, 117B and 118B, pages 711-713 (1983), that the photoluminescence spectrum of a multi-quantum well structure at 6 K (-267° C.) comprising alternate GaAs and Ga 1-x Al x As layers is dependent on the electric field applied perpendicular to the layers of the structure. A complex variation is observed, both the relative height of two luminescence peaks and the positions of these peaks depending on the electric field. The authors interpret their results principally in terms of the Stark effect on excitons. The variation in question is at wavelengths around 0.75 μm (750 nm) corresponding to photon energies of about 1.65 eV. Mendez et al make no reference to possible practical applications of their results, and in any case the complexity of the variation and also the low temperatures used make such application unlikely.
SUMMARY OF THE INVENTION
The present invention is based at least inpart on our appreciation that useful changes in absorption of photons having energies not exceeding 1.2 eV (corresponding to wavelengths of at least 0.97 μm or 970 nm) can be achieved by the application of an electric field perpendicular to the layers of a quantum well structure. Without intending to limit the scope of the present invention in any way, we suggest that the higher refractive index of suitable materials in question and the lower effective mass of conduction band electrons and of valence band holes in these materials makes excitons less stable and therefore excitonic effects less significant. In our theoretical considerations of the present invention below we have accordingly chosen to ignore excitonic effects (in favor of quantum well effects).
The present invention provides a controllable optical absorption device for use with an optical signal having a wavelength corresponding to a photon energy not exceeding 1.2 eV, which comprises (i) a semiconductor structure including one or more quantum well layers and (ii) means adapted for applying to the quantum well layer(s) an electric field such that the component of the field normal to the layer(s) may be controlled so as to determine the absorption edge of the quantum well layer(s) to be on either side of the optical signal wavelength.
The present invention provides a method of modulating or switching an optical signal having a wavelength corresponding to a photon energy not exceeding 1.2 eV which comprises introducing the signal into one or more semiconductor quantum well layers and modulating the component of the electric field normal to the quantum well layer(s) so as to move the absorption edge of the quantum well layer(s) between positions to either side of the signal wavelength.
The immediately following discussion relates, for the sake of definiteness, to the device provided by the present invention, but it is to be understood that the features referred to relate equally to the method provided by the present invention.
Preferably the photon energy referred to above does not exceed 1.0 eV (corresponding to a wavelength of 1.24 μm or 1240 nm).
Preferably, a plurality of quantum well layers is used so as to increase effectiveness. At least five layers would normally be used, and more preferably at least twenty, usually between twenty and one hundred. The layers between quantum well layers will be referred to herein as interleaving layers.
Layers to either side of the qantum well or to either side of a plurality of alternating quantum well and interleaving layers (in a direction substantially perpendicular to the quantum well layers) will be referred to herein as cladding layers.
The thickness of the quantum well layers will depend on the materials used, but they will usually lie in the range from 20 Å (2 nm) to 200 Å (20 nm).
The means for applying the electric fie1d preferably are suitable for varying the component of the field perpendicular to the quantum well layer(s) over a range of at least 10 3 volt/cm, preferably of at least 10 4 volt/cm. The upper limit on the electric field will depend on the breakdown voltage of the semiconducting materials used, which may be of the order of 2 or 3×10 5 volt/cm for III-V semiconductors. The means to apply the electric field conveniently comprises a pair of electrodes each spaced from the quantum well layer(s) by a cladding layer of semiconductor. A high resistance per unit area between the electrodes is required if high fields are to be achieved with low current flow. (High current flow causes heating and reduces operational stability.) This contrasts with quantum well lasers where relatively high current is indeed necessary. Conveniently, the quantum well layer(s) and also interleaving layers have dopant levels of less than 5×10 16 dopant atoms/cm 3 , preferably of less than 5×10 15 dopant atoms/cm 3 . In practice these low dopant levels will generally obtain into cladding layers for a depth of at least 0.2 μm, especially of at least 0.4 μm, and most especially of about 1.0 μm. A reverse-biased p-n junction may also be advantageously used in the design of the structure.
To achieve high extinction ratios (having regard to the non-sharpness of absorption edges in practice) the absorption edge should be moveable over a wavelength range corresponding to a range of photon energies of at least 5 meV, preferably at least 10 meV.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be further described with reference to the accompanying Figures (all being schematic and not necessarily to scale), of which
FIG. 1 shows in cross-section a single quantum well structure including a single quantum well in cross-section (hatching lines being omitted);
FIG. 2 shows the energy level diagram for a typical quantum well structure as shown in FIG. 1 in the absence of an applied field;
FIG. 3 shows the energy level diagram for a typical quantum well structure as shown in FIG. 1 in the presence of an applied field in the z direction;
FIG. 4 shows the theoretical absorption spectrum of a quantum well in the presence or absence of an applied field if excitonic effects are ignored;
FIG. 5 shows in section and by way of example only a device in accordance with the present invention (hatching lines being omitted);
FIG. 6 shows an integrated composite quantum well structure; and
FIG. 7 shows an optical source integrated with a quantum well structure.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, 2 represents a layer of low band gap material of thickness L (the quantum well) and 1 and 3 represent layers of relatively high band gap material. As used in this specification and claims, the term "quantum well" shall mean a layer of relatively lower band gap disposed between layers of relatively higher band gap so that both the conduction and valence band edges of the quantum well layer are bracketed and encompassed within the conduction and valence band gap of the adacent layers thereby providing quantum well confinement of both electrons and holes within the quantum well layer.
In FIG. 2 (in which the direction z and thickness dimension L have the same significance as in FIG. 1), E 4 E 5 , and E 6 represent the valence band edges of layers 1, 2, and 3 respectively while lines E 7 , E 8 , and E 9 represent the conduction band edges of layers 1, 2 and 3 in each case for bulk material. Because of the narrow width of the quantum well layer 2 the highest energy state in the valence band is E 10 and the lowest energy state in the conduction band is E 11 . (E 11 -E 8 )>(E 5 -E 10 ) because the effective mass of electrons in the conduction band is less than that of holes in the valence band.
In FIG. 3, showing the effect of an electric field, the energies of E 10 and E 11 of FIG. 2 (in the absence of an electric field) become E 10 ' and E 11 ' respectively, where (E 11 '-E 10 ')<(E 11 -E 10 ). The absorption edge of the quantum well is thereby shifted to lower energy (longer wavelengths). In addition the overlap between the conduction band states and valence band states is reduced because the field distorts the wavefunctions in opposite senses and the intensity of absorption is accordingly reduced. These effects are shown schematically in FIG. 4 comprising plots of absorption coefficient ° against photon energy E ph . 13 is the theoretical absorption spectrum in the absence of the field and 14 is the theoretical absorption spectrum in the presence of the field.
We can estimate quantitatively the effects in FIG. 4 in the case of a specific example. Let 2 be a layer of Ga x In 1-x As y P 1-y lattice-matched to InP having a thickness L of 15 nm (150 Å), and let 1 and 3 be of InP, which has a band gap of about 1.4 eV. (Lattice-matching, of course, permits epitaxial growth.) For a suitable choice of x and y, (E 11 -E 10 ) will be 0.95 eV corresponding to a wavelength of 1.3 μm. The effective masses of conduction band electrons and valence band holes in the Ga x In 1-x As y P 1-y will be approximately 0.05 m e and 0.5 m e in such a case. For a field of 10 5 volt/cm in the z direction, E 11 ' is expected to be less by about 8 meV than E 11 and E 10 ' is expected to exceed E 10 by about 32 meV. The absorption edge energy is accordingly reduced by about 40 meV corresponding to an increase in the wavelength of the absorption edge of about 0.057 μm. The absorption coefficient for the plateau to the high energy side of the absorption edge at (E 11 -E 10 ) in the no-field case, for radiation passing through the quantum well layer in the x direction shown in FIG. 1 with its electric vector polarised in the y direction, is expected to be 4000 cm -1 if one takes the well as infinitely deep. For the field of 10 5 volt/cm in the z direction, the absorption coefficient is expected to be about 640 cm -1 if one takes the quantum well as infinitely deep. Of course, the quantum well is in practice not infinitely deep and the effect on the absorption coefficient of non-confinement needs to be taken into consideration in considering practical devices (see the later discussion with respect to FIG. 5).
It must be remembered that FIG. 4 does show theoretical absorption spectra, and that in practice α is not zero below the absorption edges. From observations on bulk material we estimate that there will be on the low-energy side of the edge at (E 11 -E 10 ) in the above example an absorption tail with α≲10 cm -1 .
Rather similar effects to those in the above example could be achieved near 1.55 μm by the use instead for layer 2 of a Ga x In 1-x As y P 1-y composition also lattice matched to the InP of layers 1 and 3 having a larger band gap. Another way of achieving such effects near 1.55 μm is to use Ga x In 1-x As of bulk band gap equivalent 1.67 μm and thickness about 100 Å as layer 2 lattice matched to the InP of layers 1 and 3.
ln FIG. 5, depicting schematically a device in accordance with the present invention, 17 is a multi-quantum well structure comprising wells of thickness L similar to those described above with respect to FIGS. 1 to 4. For clarity, L is not shown to scale with the other dimensions, nor is the number of wells shown to be taken literally. The electric field is applied in the z direction by means of electrodes 15 and 21 and the light to be absorbed is directed onto end face 18 with its plane of polarisation in the y direction and the remnant after absorption in 17 emerges from end face 19. (Of course, one or both of the field and the direction of propagation could be reversed; the above senses are chosen only for the sake of definiteness.)
The multiple quantum well structure is constructed on the basis of the principles set out in the discussion of the single quantum well of FIGS. 1 to 4, except that in a multiple quantum well structure, the thickness of the high band gap materials corresponding to 1 and 3 in FIG. 1 and interleaving the well layers is subject to a compromise. If these interleaving layers are too thin, then the confinement of the wells will be inadequate (in the limiting case where the interleaving layers have zero thickness adjacent wells would merge); if on the other hand they. are too thick, the field dependence of absorption for light passing between faces 18 and 19 will be low because of high proportion of high band gap material. For the materials discussed above suitable for operation at 1.3 μm or 1.55 μm, thicknesses of the order of 150 Å (15 nm) for the wells and of 100 Å (10 nm) for the interleaving layers of high band-gap material are generally suitable. A convenient number of wells is 30.
16 and 20 are cladding layers separating the multiple quantum well structure from the electrodes (which, if the electrodes are of metal, will be highly desirable in fabrication to avoid uncontrolled doping of the quantum well region). 16 and 20 may themselves comprise sub-layers, eg in consequence of fabrication convenience. The dopant levels in the layers or sub-layers between the electrodes are such that a change of the order of tens of volts in the potential applied between electrodes 15 and 21 changes the z component of the electric field in the quantum well structure 17 by about 10 5 volt/cm. In the case of the quantum well layers, dopants in any case tend to make the quantum well effects less sharp.
16 and 20 have a higher band gap than the low band gap material of the quantum well structure and conveniently have the same band gap as the interleaving layers of the quantum well structure.
A point to be borne in mind in practical devices is that the zero-field case referred to in the discussion of FIGS. 1 to 4 above does not necessarily correspond to a zero potential applied between the electrodes 15 and 21. The device may have a built-in bias, eg as a result of junctions therein such as Schottky barriers.
Consider now the characteristics of a device as shown in FIG. 5. The values of α given above for spectra 13 and 14 in FIG. 4 are no longer appropriate for structure 17 in that one must take account of the distribution of the optical field over the quantum well layers and the interleaving layers. We estimate α above the absorption edge in the no-field case as about 2000 cm -1 and that in the with-field case as about 300 cm -1 , for radiation passing between faces 18 and 19.
Consider in particular the device of FIG. 5 in respect of radiation having a photon energy between the no-field absorption edge E 11 -E 10 ) in FIG. 4 and the with-field absorption edge (E 11 '-E 10 ') in FIG. 4. The absorption coefficient α for such radiation by the quantum wells can be expected to change from ≲10 cm -1 to 300 cm -1 between the zero-field and the with-field case (for a field of 10 5 volt/cm). A practical dimension for the absorption path (D in FIG. 5) is 200 μm. Over this path length within the quantum well material, if I is the radiation power intensity, ##EQU1## from which it follows that the radiation power intensity emerging from face 19 will be ≲82 percent of that incident on face 18 in the zero-field case and 0.24 percent of the incident in the field case, a change of 3/825dB.
It follows directly that the device of FIG. 5 is suitable for use as an amplitude modulator. For telecommunications purposes, light from a laser on continuous power can be introduced at 18 and can be amplitude shift keyed by switching between two values of the potential between electrodes 15 and 21. It would not be necessary for one of the potentials to correspond to zerofield, only that the absorption edge should be shifted from one side of the photon energy of the source to the other. There are circumstances where the use thus of an external modulator has advantages over the direct modulation of the source.
The device of FIG. 5 may also be used as an optical on-off switch for general use (rather than as a means of imparting message information to an optical signal).
The device can also be used as an adjustable filter for sources of large spectral width such as light emitting diodes.
The device may. also be used as an detector of adjustable wavelength sensitivity if means are provided for sweeping out the carriers generated by the absorption of photons in the quantum well structure. Suitably, these means comprise collector electrodes (e.g. see FIG. 6) spaced apart in the y direction.
A series of two or more such detectors, each adjustable independently of the others, can be used for time or frequency demultiplexing. For time demultiplexing, various time-varying signals are applied to the respective devices so that the optical signal associated with each frame (i.e., the applied electric field on each of successive detectors varies as a function of time in synchronism with the respectively associated time frames of a time-multiplexed optical signal) is absorbed primarily in a respective device. For frequency demultiplexing, constant but different fields would be applied to successive devices, (i.e., the applied electric field on each of successive detectors is constant albeit different from that applied to the other detectors) the first device absorbing signals of one frequency, the second absorbing those of a lower frequency than the first, and so on.
In the above, where combinations of devices or of a device with a laser are referred to, it is to be understood that integration may be convenient. Thus for example (see FIG. 6) two selective detectors 30, 40 may have continuous layers 50 corresponding to 16, 17, and 20 in FIG. 5, but separate electrodes 32-34, 42-44 corresponding to 15 and 21 and separate collector electrodes 92. A semiconductor optical source 60 also may be optically coupled to and/or integrated with the incident end of a quantum well modualtor/demodulator structure as depicted in FIG. 7. | An optical device having controllable absorption for an optical signal having a wavelength corresponding to a photon energy not exceeding 1.2 ev comprises (i) a semiconductor structure including one or more quantum well layers and (ii) means adapted for applying to the quantum well layers(s) an electric field such that the component of the field normal to the layer(s) may be controlled so as to determine the absorption edge of the quantum well layer(s) to be on either side of the optical signal wavelength. The device may be used as an optical modulator or switch and in optical demultiplexing. | 1 |
FIELD OF THE INVENTION
This invention relates generally to a friction spinning apparatus and method for forming a three component corespun yarn, and more particularly to such an apparatus and method which includes a trumpet with a pair of guiding passageways for guiding a sliver and roving of fibers into the draw frame section of the apparatus so that these slivers form a core and a core wrapper of the corespun yarn.
BACKGROUND OF THE INVENTION
It is known to form a two component corespun yarn on a friction spinning apparatus. For example, U.S. Pat. Nos. 4,249,368 and 4,327,545 disclose a DREF type of friction spinning apparatus in which a single sliver of fibers is fed into the entrance end of a draw frame section and then fed through an elongated throat extending between a pair of rotating suction drums where drawn wrapping fibers are fed into the elongated throat and are wound about the fibers extending along the elongated throat to form the two component corespun yarn. U.S. Pat. No. 4,107,909 discloses a similar type of friction spinning apparatus in which a core yarn is fed into the elongated throat where drawn wrapping fibers are wrapped about and wound about the core yarn to form a two component corespun yarn. While the types of fibers making up the sliver and/or yarn fed into the draw frame section and the types of fibers making up the drawn wrapping fibers fed into the elongated throat can be varied to form two component corespun yarns with varying characteristics, the number of different types of corespun yarns which may be produced on this known type of friction spinning apparatus is limited.
SUMMARY OF THE INVENTION
With the foregoing in mind, it is an object of the present invention to provide a friction spinning apparatus and method for forming a three component corespun yarn wherein a pair of slivers of fibers is fed into the draw frame section to form a core and a core wrapper surrounding and covering the core, with an outer sheath of drawn wrapping fibers being fed into an elongated throat extending between a pair of rotating suction drums and wrapped around and surrounding the core and the core wrapper. The present apparatus and method makes it possible to produce a wide variety of different types of three component corespun yarns which were not heretofore available.
In accordance with the present invention, the friction spinning apparatus includes a trumpet positioned adjacent the entrance end of the draw frame section and including a pair of guiding passageways for guiding respective pairs of slivers of fibers into the draw frame section to form a core with a core wrapper surrounding and covering the core. As the core and core wrapper pass through the elongated throat extending between a pair of rotating suction drums, drawn wrapping fibers are fed into the elongated throat and wound about the core and the core wrapper to complete the formation of the three component corespun yarn.
The pair of guiding passageways extend through the trumpet of the friction spinning apparatus of the present invention and are preferably vertically aligned, one above the other, so that the sliver of core fibers fed through the upper guiding passageway is directed onto the top and in the center of the sliver of core wrapper fibers directed through the lower guiding passageway. The fibers are fed in this position so that the core wrapper fibers surround and cover the core fibers as they are drawn in the draw frame section and pass into the elongated throat extending between the rotating suction drums.
The trumpet is preferably molded of plastic material and includes an exit end portion having a pair of inwardly curved surfaces joined together at an outwardly extending apex. The inwardly curved surfaces substantially conform to the peripheral surfaces of the first pair of draw rolls of the draw frame section and the apex is positioned adjacent the nip of the first draw rolls in the draw frame section. The exit ends of the guiding passageways terminate at the apex of the trumpet so that the relationship of the slivers of fibers is maintained in a positive manner until the slivers of fibers are passed into the nip between the first pair of draw rolls of the draw frame section. The entrance face of the trumpet is substantially planar and is provided with an integrally molded and outwardly extending horizontal rib extending between the vertically spaced entrance ends of the guiding passageways to aid in preventing migration of fibers from one sliver to the other as they are guided into and through the trumpet.
The friction spinning apparatus and method of the present invention may be utilized to form a wide variety of different types of three component corespun yarns. For example, the present friction spinning apparatus has been used in the formation of a three component corespun yarn for forming fabric useful in the production of fire resistant safety apparel of the type disclosed in our co-pending application Ser. No. 288,682, filed Dec. 22, 1988.
The corespun yarn of this co-pending application includes a core of high temperature resistant fibers, a core wrapper of low temperature resistant fibers surrounding and covering the core, and an outer sheath of low temperature resistant fibers surrounding and covering the core wrapper. Also, the friction spinning apparatus of the present invention can be utilized in forming a three component corespun yarn in which either the same or different types of fibers can be used to form the core, the core wrapper, and the outer sheath.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages will appear as the description proceeds when taken in connection with the accompanying drawings, in which
FIG. 1 is a fragmentary isometric view of a portion of the friction spinning apparatus of the present invention;
FIG. 2 is an enlarged isometric view of the entrance trumpet, removed from the spinning apparatus, and illustrating the upper and lower guide passageways formed therein;
FIG. 3 is a side elevational view of the entrance trumpet shown in FIG. 2;
FIG. 4 is a greatly enlarged view of a fragment of a three component corespun yarn formed on the friction spinning apparatus of the present invention and illustrating portions of the outer sheath and core wrapper being removed at one end portion thereof; and
FIG. 5 is a greatly enlarged isometric view of a fragmentary portion of a fabric woven of the yarn of FIG. 1, with the right-hand portion having been exposed to a flame.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One type of three component corespun yarn, broadly indicated at 10, which may be produced by the friction spinning apparatus and method of the present invention is illustrated in FIG. 4. The corespun yarn 10 includes a core 11 of fibers extending primarily in the axial or longitudinal direction, a core wrapper 12 of fibers surrounding and covering the core 11 and extending primarily in an axial direction, and an outer sheath 13 of fibers surrounding and covering the core wrapper 12 and extending primarily in a circumferential direction. The fibers of the core 11 and the core wrapper 12 enhance the tensile strength of the yarn while the fibers of the outer sheath 13 are located on the outer surface of the yarn and provide the desired appearance and general characteristics which are to be imparted to the corespun yarn 10.
The corespun yarn 10 is produced on a DREF friction spinning apparatus which has been modified in accordance with the present invention, in the manner illustrated in FIGS. 1-3. The friction spinning apparatus includes a core and core wrapper drafting section having a succession of pairs of drafting or draw rolls 20, 21 and 22 with a modified type of entrance trumpet, broadly indicated at 23, positioned adjacent the nip of the first set of drafting rolls 20. Conventional trumpets 24 are positioned in the nips of the successive pairs of drafting rolls 21, 22. A set of delivery rolls 25 is provided at the exit end of the drafting section and operates to deliver and guide yarn into an elongated throat formed between a pair of perforated suction drums 26, 27 which are rotated in the same direction by a drive belt 28 and a drive pulley 29.
A plurality of sheath fiber slivers 13 is guided downwardly into draw frame rolls 30, between carding drums 31 and then fed into the elongated throat formed between the pair of perforated suction drums 26, 27 to be wrapped around the outer surface of the yarn. As the yarn leaves the exit end of the elongated throat between the pair of perforated drums 26, 27, it passes between withdrawing rolls 33 and is directed over and under yarn guides 34, 35 and to the conventional take-up mechanism of the apparatus, not shown.
As illustrated in FIGS. 2 and 3, the modified entrance yarn trumpet 23 includes a planar, vertically extending, entrance face 36, a lower yarn guide passageway 39 through which the core wrapper sliver 12 is directed, and an upper yarn guide passageway 40 through which the yarn core roving 11 is directed. The planar front or entrance face 36 of the entrance trumpet 23 is provided with an integrally formed and outwardly extending horizontal guide rib or bar 42 which serves to maintain separation of the fibers of the core roving 11 and the core wrapper sliver 12 as they move into the entrance ends of the respective guide passageways 40, 39 of the entrance trumpet 23. The exit end of the trumpet 23 is provided with inwardly curving converging surfaces 43, 44 conforming substantially to the configuration of the peripheral surfaces of the first pair of draw rolls 20. The inwardly curving surfaces 43, 44 are joined together at an outwardly extending apex 45 which is positioned adjacent the nip of the pair of draw rolls 20.
The forward or entrance ends of the guide passageways 39, 40 are vertically aligned and spaced apart below and above the guide rib 42. The exit end of the guide passageway 40 is positioned above and adjacent the exit end of the lower guide passageway 39 so that the core roving 11 is positioned on top of and in the center of the core wrapper sliver 12 as they pass between the nip of the first set of drafting rolls 20. The fibers are drawn as they pass through the succession of drafting rolls 20, 21 and 22 of the drafting section and the core wrapper sliver 12 surrounds the fibers of the core 11.
As the core wrapper 12 and the core 11 move forwardly from the delivery rolls 25 and through the friction spinning section formed by the elongated throat between the perforated rotating suction drums 26, 27, the fibers of the outer sheath 13 are wrapped around the same in a substantially circumferential direction so that the outer sheath 13 completely surrounds and covers the core wrapper 12 and the core 11. The corespun yarn 10 is then removed through the exit end of the friction spinning section by the withdrawing rolls 33 and is directed onto the take-up package, not shown.
A wide variety of different types of fibers may be utilized to form the core 11, the core wrapper 12, and the outer sheath 13. It has been found that a particularly useful three component corespun yarn can be formed on the friction spinning apparatus of the present invention by feeding a core roving 11 of high temperature resistant fibers into the upper guide passageway 40 of the trumpet 23, feeding a core wrapper sliver 12 of low temperature resistant fibers into the lower guide passageway 39, and feeding a plurality of slivers of low temperature resistant fibers 13 into the draw frame rolls 30. This three component corespun yarn is then woven or knit to form a fabric which is highly useful in the production of fire resistant safety apparel.
For example, a very effective fire resistant fabric has been formed in accordance with the following nonlimiting example. A core roving 11 comprising 40% PBI fibers and 60% Kevlar fibers, and having a weight necessary to achieve 20% in overall yarn weight, is fed into the upper guide passageway 40 of the entrance trumpet 23. A core wrapper sliver 12 comprising 100% cotton staple fibers, and having a weight necessary to achieve 30% in overall yarn weight, is fed through the lower guide passageway 39 in the entrance trumpet 23. A plurality of outer sheath slivers 13, comprised entirely of cotton fibers, is fed into the draw frame rollers 30 and in an amount sufficient to achieve 50% in overall yarn weight.
The resulting corespun yarn 10 is woven into both the warp and filling to form a 5.5 ounce plain weave fabric, of the type illustrated in FIG. 2. This woven fabric is dyed and subjected to a topical fire resistant chemical treatment, and a conventional durable press resin finish is then applied thereto. The resulting fabric exhibits durable press ratings of 3.0+ after one wash, and 3.0 after five washes. This fabric also exhibits colorfastness when subjected to a carbon arc light source of a 4-5 rating at 40 hours exposure. This fabric is then subjected to a National Fire Prevention Association test method (NFPA 701) which involves a vertical burn of 12 second duration to a Bunsen burner flame, and the fabric exhibits char lengths of less than 1.5 inches with no afterflame or afterglow. In accordance with Federal Test Method 5905, a vertical burn of two 12 second exposures to a high heat flux butane flame shows 22% consumption with zero seconds afterflame, as compared with 45% consumption and 6 seconds afterflame for a 100% Nomex III fabric of similar weight and construction. Hot air shrinkage of the corespun fabric was tested in a heated chamber at 468° F. for five minutes and shrinkage was less than 1% in both warp and filling direction.
Throughout all burn tests, the areas of the fabric char remain flexible and intact, exhibiting no brittleness, melting, or fabric shrinkage. The portion of the fabric illustrated in the right-hand portion of FIG. 2 is speckled to indicate an area which has been subjected to a burn test and to illustrate the manner in which the low temperature resistant fibers become charred but remain in position surrounding the core of high temperature resistant fibers. The charred fibers of the outer sheath 13 and the core wrapper 12 remaining in position around the core 11 provide a thermal insulation barrier and insulating air layer between the skin and the fabric, when the fabric is utilized to form a firefighter's shirt or the like.
It is to be understood that the friction spinning apparatus and method of the present invention are not limited to the production of yarn and fabric useful in the production of fire resistant safety apparel of the type set forth above but may be utilized in producing a wide variety of different types of three component corespun yarns, useful in the formation of a wide variety of different types of fabrics. The three component corespun yarns produced by the friction spinning apparatus of the present invention each includes a core 11 with the fibers extending primarily in an axial or longitudinal direction of the yarn, a core wrapper 12 of fibers surrounding and covering the core 11 and with the fibers extending primarily in the axial or longitudinal direction of the yarn, and an outer sheath 13 of fibers surrounding and covering the core wrapper 12 and with these fibers extending primarily in a circumferential direction around the corespun yarn 10. The feeding of the additional fibers to the friction spinning apparatus is made possible by the provision of an entrance trumpet which includes a pair of guide passageways for directing and maintaining the core fibers and the core wrapper fibers in the proper relationship as they are directed through the drafting section of the friction spinning apparatus.
In the drawings and specification there has been set forth the best mode presently contemplated for the practice of the present invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims. | The present friction spinning apparatus includes a draw frame section with an entrance trumpet including first and second fiber sliver guiding passageways for forming a three component corespun yarn. One of the guiding passageways directs a core roving into the draw frame section while the other sliver guiding passageway directs a core wrapper sliver into the draw frame section so that the core wrapper fibers surround the core fibers. Wrapping fibers are then wound about the core and core wrapper fibers in an elongated throat extending between a pair of rotating suction drums. | 3 |
RELATED APPLICATIONS
This application is a Continuation of and claims the priority benefit of U.S. application Ser. No. 14/878,378 filed Oct. 8, 2015, which is a Continuation of and claims the priority benefit of U.S. application Ser. No. 14/306,185 filed Jun. 16, 2014 and issued as U.S. Pat. No. 9,171,056, which is a Continuation of and claims the priority benefit of U.S. application Ser. No. 13/794,055 filed on Mar. 11, 2013 and issued as U.S. Pat. No. 8,768,937, which is a Continuation of and claims the priority benefit of U.S. application Ser. No. 09/730,538 filed on Dec. 7, 2000 and issued as U.S. Pat. No. 8,402,068, all of which are herein incorporated by reference in their entirety.
BACKGROUND OF THE DISCLOSURE
1. Field of the Disclosure
The present disclosure relates generally to a system and method for collecting and presenting product and vendor information on a distributed network such as the Internet.
2. Background and Related Art
It is known to sell products on a distributed network such as the Internet. Online sales or e-commerce is a rapidly growing segment of the economy. Systems for selling products on a distributed network are sometimes referred to as electronic merchandising systems or virtual storefronts. It is further known to aggregate in one user interface access to multiple online vendors to enable a user to choose among several retailers' goods. Sites containing multiple vendors are sometimes referred to as electronic or virtual malls, or shopping agents or “bots.” An electronic vendor or electronic mall provides a display that generally includes images and descriptions of merchandise. These sites also generally provide the vendors' prices for the product. Shopping agents or “bots” aggregate product pricing information from multiple vendors on a single site.
In addition to serving as an avenue for commerce, a distributed network allows consumers to access considerable amounts of information about products. For example, consumers can research products by accessing information provided by manufacturers, vendors, distributors, etc. Consumers also may research products through third-party sites, such as ConsumerReports.org®, that publish industry reviews of products.
Consumers may further communicate with each other to exchange product experiences and information. For example, consumers may interact on Usenet discussion groups to share information such as personal experiences with products. In addition, it has been proposed by the assignee of the present disclosure to survey consumers regarding the quality of particular products and/or services and to publish or advertise the results of the survey as numerical ratings. Recently, with the rapid technological advancement of the Internet, it has become further possible for individual consumers to provide narrative reviews of products and/or services, in addition to the standardized scaled ratings.
A consumer can also research information on vendors. For example, vendors typically provide on their websites information such as their shipping, billing and return policies. As with products, consumers also may communicate with other users to exchange experiences and information related to vendors on online discussion groups or at third-party sites that allow users to rate and review vendors. There further exist websites, such as gomez.com and bizrate.com, that allow users to rate vendors.
Although there is an abundance of vendor and product information on the Internet, this information is distributed over numerous websites. To access the information, consumers need to locate these various websites. However, consumers may have difficulties finding the various websites. For instance, searching under a product name on a search engine may locate millions of websites, most of which provide little or no relevant information. Accordingly, there presently exists a need for a methodology to provide a single source for information on products and vendors.
Furthermore, even if a user locates the various websites containing the desired product and vendor information, the large amount of information provided is not organized for easy access by the user. Because there exists so much information, consumers may have difficulty sorting, comparing and using it. Consequently, there further exists a need for a methodology to organize and present product and vendor information for easy access by consumers.
It is generally known to use a database to electronically organize and store information. In the most general sense, a database is a collection of data. Various architectures have been devised to organize data in a computerized database. Typically, a computerized database includes data stored in mass storage devices, such as tape drives, magnetic hard disk drives and optical drives. The three principal database architectures are termed hierarchical, network and relational. A hierarchical database assigns different data types to different levels of the hierarchy, with each record having one owner. In this way, links between data items on one level and data items on a different level are simple and direct. However, a single data item can appear multiple times in a hierarchical database, which creates data redundancy. To eliminate data redundancy, a network database stores data in nodes having direct access to any other node in the database. In the network database, each record has multiple owners, and there is no need to duplicate data since all nodes are universally accessible. Alternatively, in a relational database such as Oracle®, Sybase®, Informix®, Microsoft SQL Server®, Access®, and others, the basic unit of data is a relation that comprises attributes and tuples. The records in a relational database have no owner.
In an implementation of a relational database, a relation corresponds to a table having rows, where each row corresponds to a tuple, and columns, where each column corresponds to an attribute. From a practical standpoint, rows represent records of related data and columns identify individual data elements. A table defining a retailer's product line may, for example, have product names, product numbers (e.g., Stock Keeping Units or SKUs), prices and other product features. Each row of this table holds data for a single product and each column holds a single attribute, such as a product name. The order in which the rows and columns appear in a table has no significance. In a relational database, one can add a new column to a table without having to modify older applications that access other columns in the table. Relational databases thus provide flexibility to accommodate changing needs.
All databases require a consistent structure, termed a schema, to organize and manage the information. In a relational database, the schema is a collection of tables. Similarly, for each table, there is generally one schema to which it belongs. Once the schema is designed, a tool, known as a database management system (DBMS), is used to build the database and to operate on data within the database. The DBMS stores, retrieves and modifies data associated with the database. Lastly, to the extent possible, the DBMS protects data from corruption and unauthorized access.
A human user controls the DBMS by providing a sequence of commands selected from a data sublanguage. The syntax of data sublanguages varies widely, but the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO) have adopted Structured English Query Language (SQL) as a standard data sublanguage for relational databases. SQL comprises a data definition language (DDL), a data manipulation language (DML) and a data control language (DCL). DDL allows users to define a database, to modify its structure and to destroy it. DML provides the tools to enter, modify and extract data from the database. DCL provides tools to protect data from corruption and unauthorized access. Although SQL is standardized, most implementations of the ANSI standard have subtle differences. Nonetheless, the standardization of SQL has greatly increased the utility of relational databases for many applications, including retail sales and merchandising operations.
Although access to relational databases is facilitated by standard data sublanguages, users still must have detailed knowledge of the database's terminology to obtain needed information from a database since one can design many different schemas to represent the storage of a given collection of information. For example, in an electronic merchandising system, a merchant may elect to store product information, such as a product SKU, product name, product description, price and tax code, within a relational database. Another merchant may elect to store a different product SKU, product name, description, price and tax code in a table. In this situation, an SQL query designed to retrieve a product price from one merchant's database is not useful for retrieving the price for the same product in the other merchant's database because the differences in data types require the use of different SQL queries. As a consequence, developers of retail applications accessing product information from relational databases have to adapt their SQL queries to each individual schema. This, in turn, prevents their applications from being used in environments where there are a wide variety of databases having different schemas, such as the World Wide Web.
The rapid development of the World Wide Web (Web) has facilitated the use of online merchant systems. Online merchant systems enable merchants to creatively display and describe their products to a global audience of shoppers using Web pages defined by an output language such as hypertext markup language (HTML). HTML enables merchants to lay out and display content, such as text, pictures, sound and video. Web shoppers access a merchant's page using a browser, such as Microsoft Explorer® or Netscape Navigator®, installed on a client connected to the Web through an online service provider, such as the Microsoft Network® or America OnLine®. The browser interprets the HTML to format and display the merchant's page for the shopper. The online merchant system likewise enables shoppers to browse through a merchant's store to identify products of interest, to obtain specific product information and to electronically purchase products after reviewing product information. Merchants often store product data, such as product descriptions, prices and pictures, in relational databases. Online merchant systems, therefore, have to interface with merchant databases to access and display product information. As each merchant organizes their product information differently, there is a large installed base of databases having a wide variety of data types for product information.
This problem is even greater for websites that seek to advertise and sell products from a variety of online merchant systems. A problem with finding product information on the Internet is that the same product may have numerous names or identifiers depending on the merchant's site on which it is stored. In particular, a product may be identified by its model name, serial number, SKU assigned by the vendor, distributor part number, etc. Even these identifiers may vary greatly. For example, a product may have numerous model names because the name varies from country to country, the manufacturer may periodically change the product's name, or the manufacturer, consumers and merchants may use numerous different names to refer to the same product. Similarly, different vendors use different SKU numbers. As a result, a user may have great difficulty correlating product information about the same product from different sources.
Much information on products is available on the web. For example, it is well known for vendors to provide information, such as product price, on a website. U.S. Pat. No. 5,740,425 by Povilus, for DATA STRUCTURE AND METHOD FOR PUBLISHING ELECTRONIC AND PRINTED PRODUCT CATALOGS, incorporated herein by reference, provides a data structure and method for creating a product database, which defines classes of product groupings and preferably includes a listing of SKUs that correspond to a product or a component of a product. The product database further includes product information for each associated SKU. Similarly, many manufacturers of products provide online information about their products. The manufacturers may further provide technical support and assistance over the Internet. In addition, many Internet sites provide reviews of products. These sites may have writers that test and review the products. Alternatively, the sites may allow users to place their opinions about a product for other users to view. These consumer-posted reviews provide special insights into products because they reflect actual experiences with the product.
However, because the product information from different sources cannot be viewed together, the utility of this abundance of information is limited.
In a preferred embodiment, the website allows the user to select the product from a list of multiple products. In turn, the website may allow the user to select the list of products from a list of classes of products. Alternatively, the website may allow the user to select desired product features and then create a list of products that possess these features.
In another embodiment, the website may allow the user to add a review or rating of the product. The website may also optionally indicate what information other users have found to be useful.
In another embodiment, the website includes decision guides that suggest a product to the user in response to a user input.
Accordingly, the present disclosure provides a single website to provide and organize the product and vendor information available on a distributed network, such as the Internet.
According to a preferred embodiment, the disclosure provides three principal instrumentalities for collecting, normalizing, associating and presenting data to a user. In order to be able to carry out attribute- or parameter-based searches of a database for products or other data objects (for simplicity, hereinafter the term “product” shall be used generically to mean any data object searchable on a database, such as for example products, services, news items, demographic, historical, scientific or statistical information, financial instrument or securities information, real estate information, and the like), consistent terminology and ontology must exist in the database. Additionally, in order to avoid having “orphaned” or non-related items of data present in the database, it is desirable to provide the capability of associating such items of data with other, similar products, based on shared attributes. Thirdly, it is desirable to reduce the time required to complete a parameter-based product search of a database.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will be described in detail with reference to the following drawings in which:
FIG. 1 is a flowchart illustrating a method for normalizing and associating gathered product information into a database in accordance with an embodiment of the present disclosure;
FIG. 2 is a table for translating or normalizing diverse product identifiers to the same products to which they are referring;
FIG. 3 is a table associating core product identifiers with corresponding domains and attributes;
FIG. 4A is a database file format showing the arrangement of product information for retrieval;
FIG. 4B is a character string look up table associating a multiplicity of character strings with unique integers;
FIG. 5 is a schematic diagram of a system for collecting, storing, and outputting product information in accordance with an embodiment of the present disclosure; and
FIGS. 6, 7A-7C, 8 and 9 are examples of displays of information obtained as a result of the method of FIG. 1 ; and
FIG. 10 illustrates a name database, according to an embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In one aspect of the present disclosure, a method is provided for the collection and storage of product information in a database from which it can be quickly and efficiently searched by a user and the results displayed. As illustrated in FIG. 1 , the first step 1001 of the method is the collection of product information and associated vendor information from the Internet or from other sources.
The collecting of product and vendor information can be carried out in a variety of ways. Some of the information may already reside at a website server in association with other applications and functions. For example, a vendor's site will already contain data relating to the vendor and the products sold by the vendor. This data may be retrieved by using known “scraper” technology and loaded into a database at step 1002 . The data may be subsequently combined with additional information collected from other sources.
For example, the additional information may be collected manually by a human operator at step 1001 who examines various sources such as third-party websites, publications, brochures, manufacturer specification sheets, vendor advertisements, etc., for pertinent data. The human operator at step 1002 then loads this information into an information storage device such as a database contained on a server. For example, the operator may examine and record the inventory and pricing information displayed on a vendor's website.
Alternatively, information may be collected directly from a server controlling the third-party information source. For instance, a vendor may sell or provide a list of its inventory and the prices for the products in the inventory in electronic form. The list then may be transferred directly from the third-party server to the information storage device.
As mentioned above, the information also may be obtained automatically through the use of programs that search for desired information on a distributed network such as the Internet. Scraper programs automatically examine third-party websites and create an output forwarding desired contents of the website to the information storage device. For example, a scraper program can be designed to search the website of a vendor for the prices of products sold by the vendor. The scraper may run either in real time, upon a request by the user, or in batch mode so that the vendor's prices are periodically examined and stored, such as on a weekly basis. Generally, there is a different scraper program for each type of information from each information source. In this way, a scraper can be designed specifically to locate desired information on the third-party website and to interpret the format of this information.
The scrapers preferably create an output using Extensible Markup Language (“XML”) to return information from the third-party site in a usable format. XML is a web language similar to the standard hypertext markup language (“HTML”), but the XML rules are more complex to allow more varied uses. In particular, XML is more interactive and better suited for electronic commerce because the coding contains markers the simplify the standardization of information over the Internet. This feature allows the use of intelligent agents that seek out consistent information and then act on what they find. Furthermore, the parsers in XML can be small and fast and can read complex hierarchical structures.
The information may be gathered through a combination of all the above methods in order to gather the information in the most efficient manner.
As the information is gathered, it is deposited into a storage device such as a database on a server for storage and easy future access. It is well known to use databases to store and organize data. For instance, the following example shows a database containing information on two vendors that sell the same product.
EXAMPLE 1
Vendor's
Price for
Vendor
Name
product
Availability
Rating
Profile
A
$1
Yes
4.5
A.doc
B
$2
No
4.3
B.doc
In this example, the same product is sold at Vendor A and Vendor B. Vendor A charges $1 for the product, has the product in stock, and has a vendor rating of 4.5. The database further indicates that a profile for Vendor A is stored in the file, A.doc. Similarly, Vendor B sells the product for $2, does not have the product in stock, has a vendor rating of 4.3, and has a profile stored in the file B.doc.
The information collected will typically contain one or more product identifiers, such as a UPC, a manufacturer model number, a distributor part number, a vendor-specific SKU, etc. The information will further include data such as the product name, type of product (domain), and various attributes of the product with specific values for each listed attribute.
In order to have the ability to perform a parameterized or even accurate search on such information, it is necessary to have consistent and normalized data in the database. For example, a search for “XGA” will not retrieve as a “hit” data for a laptop computer in which screen size is specified as “1024.times.768,” even though these two terms refer to the identical type of display. Accordingly, the present disclosure provides a normalization engine that translates or normalizes a list of attributes and values describing an object (product) into a list containing a canonical representation for each attribute and value, in addition to a canonical domain describing the product in general (such as “notebook” to describe a portable computer, which also may be identified as a “laptop” computer). For example, the domain “laptop” would be normalized to refer to the domain “notebook,” where “notebook” would be selected by the data entry operator as the canonical representation. Similarly, attribute/value pairs, such as “screen_size-xga” would be normalized to “display res=1024.times.768.”
This is carried out by maintaining a list of aliases or translations for canonical domains, attributes and values in the database. Each known alias for a canonical domain term, attribute term, and value term is listed in the alias list in the database with a corresponding entry identifying the canonical representation into which the alias will be translated as the object or product information is being loaded into the database. An operator may add entries by detecting new synonyms for a canonical term in an object file and indicating the canonical term for the detected synonym. All existing occurrences of the synonym term in the database are then translated into the indicated canonical term, and the synonym is then added to the alias list, such that subsequent data entries containing that synonym will thereafter automatically be translated into the canonical representation for entry into the database.
Before the loaded information at step 1002 can be assimilated into the database, it is first determined at step 1003 whether the information pertains to an existing product already stored in the database. If so, the new information is merged into the listings for the existing product. In case of a conflict with pre-existing information for the product, a choice may be made as to which information should take precedence. If the new information can be confirmed as corresponding to updated information with respect to the stored information, then the new information may be written in place of the pre-existing information in the database. Otherwise, the pre-existing information can be selected to take precedence over the newly loaded information. FIG. 2 shows a product map or table 2000 containing a list of known product identifiers 2001 , and their corresponding core product identifier 2002 . The core product identifier can be an arbitrary integer selected by the operator to identify a particular product, which may be known by various identifiers, as mentioned above. In the example, both product id # 2 and product id #N refer to the same core product, as indicated by the same core product identifier, 790 , contained in the map.
At step 1004 it is determined whether or not the product identifier contained in the new information is found in the product map 2000 . If not, at step 1005 a new product listing is created in the database with the associated attribute/value pairs for the product. When a new domain, attribute or value is added to the database it is marked as “new.” New data items will not be displayed as part of a search result until an editor or operator has reviewed them to determine their appropriate display representation, sorting order, and whether or not they can be identified as aliases for pre-existing information in the database.
If the identifier is found, at step 1006 normalization of the domains, attributes and values is initiated. It is noted that translations are performed in a product-specific manner; thus, the attribute alias list for the attribute “display_res” for a laptop does not apply to a PDA device or a desktop PC. Similarly, the value alias list for the value “1024.times.768” for a laptop would be specific to the attribute “display_res” within the laptop domain and would not apply to a value for an attribute. Thus, at step 1007 the domain name of the object is compared against a domain alias list, and translated into its canonical representation as indicated in the alias list. Once the canonical domain name is obtained, each of the attributes is compared with the alias list of attributes associated with the canonical domain name map at step 1008 , and each value of the attribute/value pair is then compared with the canonical attribute map at step 1009 . At step 1010 it is determined whether additional attribute/value pairs exist in the new information that need to be normalized. If so, the process returns to step 1008 . If not, the process ends at step 1011 . Alternatively, all of the attributes can be translated together at step 1008 , and then all of the values associated with each attribute can be translated together at step 1009 .
According to the disclosure, all information in the entire database can be updated to normalize data already in the database in real time as the aliases are added to the database, by maintaining the translation rules together with the data set in the database. Additionally, the normalization process enables all attribute information to be normalized to a common unit base (e.g., normalizing all units of length into millimeters, etc.).
An example of such a domain map 3000 is shown in FIG. 3 . Each core product identifier 3001 has a canonical domain 3002 , which in turn is associated with a number of canonical attributes 3003 , 3004 , 3005 . For each of the attributes an alias list is maintained containing all known aliases for the canonical attribute. The same applies to values for each attribute. The values are sorted in numerical order where possible; for values which are not simple numbers, the sorting order can be defined by the operator on a per attribute basis. By identifying the same attribute values as pointing to the same product, it is possible to effect product and domain merges in the database automatically by defining a threshold overlap level by which attributes for separate product records in the database are the same. Once the two (or more) separately stored product records have been identified as pertaining to the same product, the records can be merged into a single record in the database containing all of the product attributes in one location.
The domain editor is a Java application user interface used to manipulate data in the database, such as setting the display characteristics for the domain and attribute strings, allowing the operator to translate and normalize attribute and value information, editing of data values, merging attributes, and merging domains. By setting a threshold level of overlap, the normalization engine can automatically suggest to a user possible domain merges or product merges.
Further, if the product information contains multiple identifiers, each of the identifiers can be compared with the stored product identifiers, and any new identifiers may be added to the map as being associated with or mapped to the canonical representation found for at least one of the identifiers. This can be done since it is known that all the identifiers pertain to the same product, as they were bundled together in the information collected. In this way, the database can be made to “learn” new product aliases as more and more information is loaded into it, thereby associating more and more of the information stored in the database as information is added.
An association engine makes it possible to associate previously orphaned pieces of data with product records, as more aliases are added and associations made in the database.
As illustrated in FIG. 10 , the present disclosure provides a name database 10 containing data locations 1 for storing multiple different identifiers for each of a number of products. The name database 10 may be an array with columns 20 that represent product attributes, and rows 30 that represent the different identifiers for each attribute. The name database 10 is further characterized by an indication of the relationships between the different identifiers in separate classes. For example, FIG. 10 illustrates arrows 60 that link the different existing identifiers for a similar product. The direction of the arrow 60 in FIG. 10 shows a horizontal pattern used for hierarchical databases. However, arrow 60 may travel in any direction, in accordance with the possible relationships among the data in the name database 10 .
An illustrative example is provided below:
EXAMPLE 1: A NAME DATABASE, LINKING TO
INFORMATION FOUND AT SEVERAL DIFFERENT SOURCES
1A: Manufacturer's Database
MODEL
COLOR
r
RED
b
BLUE
1B: Vendor 1 Database
SKU 1
COST
10
$2
1C: Vendor 2 Database
SKU 2
COST
100
$3
1D: Naming Database
MODEL
SKU 1
SKU 2
r
10
b
100
In this example, the manufacturer produces two models, model r that is red and model b that is blue. However, the manufacturer does not provide information on the prices of the models. Vendor 1 sells a model with a SKU of 10 for $2 and Vendor 2 sells a model with a SKU of 100 for $3. However, neither Vendor 1 nor Vendor 2 indicates which model corresponds to the SKU employed by the vendor. Only through accessing the naming database can a consumer recognize that Vendor 1 sells model r and Vendor 2 sells model b. In this way, the naming database serves as a modern Rosetta stone to associate the proprietary nomenclature from one source of product information with another source.
In the embodiment demonstrated in Example 1, the name database includes no information on the products, but instead only provides the identifiers and their interrelationships. It should be appreciated however, that the naming database could also include product information, as seen in the following example.
EXAMPLE 2: PRODUCT NAMES AND PRODUCT
INFORMATION ARE ON THE SAME DATABASE
MODEL
SKU 1
SKU 2
COLOR
COST
r
10
RED
$2
b
100
YELLOW
$3
g
20
200
GREEN
$3
In this example, the name database has combined the databases of Example 1, and information on a new model g is provided. As a result, the illustrated hierarchical database provides all known information on models r, b, and g. New model g, as indicated in the database, has a green color, costs $3 and is available as SKU 20 at vendor 1 and as SKU 200 at vendor 2. In this example, new types of information are added to the database as additional columns and additional products are added as new rows. In this example, as well as in Example 1, the relationships between the product identifiers are defined by the rows 30 and columns 20 . In particular, different identifiers for the same product appear in the same row 30 , and identifiers for different products from the same source appear in the same column 40 .
In addition, FIG. 10 illustrates product information columns 40 in the name database 10 . As described above, the product information database 10 may include virtually any type of data related to the product. For example, the product information columns 40 may contain links to third party reviews of the particular product or to an Internet discussion regarding the product. Conversely, the product information may provide information on similar, competing products or indicate possible vendors for purchase to the product. The product information may further include related advertisements or pictures of the product.
As seen in the Cost column of Example 2, data entries may be redundant in a hierarchical base. To address this concern, the present disclosure preferably uses a relational database, as illustrated in the following example.
EXAMPLE 3: RELATIONAL NAME DATABASE
OF THE INFORMATION IN EXAMPLE 2
MODEL
SKU 1
SKU 2
COLOR
COST
1
r
10
100
RED
$2
2
b
20
200
YELLOW
$3
3
g
GREEN
With this relational database, a vector in the form of [model, SKU 1, SKU 2, color, cost] shows the relative relationship between the data in each column, rather than merely looking horizontally. In this example, the relationship vectors are [1, 1, 0, 1, 1], [2, 0, 1, 2, 2], and [3, 2, 2, 3, 2]. In other words, [1, 1, 0, 1, 1], corresponds to the first model (r), which has the first listed value of SKU 1(10), no value of SKU 2, the first listed color (red) and the first listed cost ($2).
It should be appreciated that other database formations are possible and are well known in the field. The database structures illustrated in FIG. 1 and the above examples may be easily modified to form different structures that perform the same function. For example, the name database 10 may be restructured so that new rows contain new data types and new columns contain additional members of known data types. Similarly, the name database 10 may be multi-dimensioned. For instance, the name database 10 may have three dimensions: one to store the different products; a second to store the different names for the same product; and a third to store the various data about the product.
In one embodiment, name database 10 assigns a universal SKU 50 to every product. The universal SKU 50 may be, for example, an alphanumeric code. In this way, the name database 10 has a system for labeling the various products, which does not have to be altered as changes are made to the identifiers for the product. In another embodiment, the name database 10 is formed using SQL to permit easy additions and changes to the name database 10 .
In order to make use of the normalized and associated information that is stored in the database, it must be capable of being queried by clients and presented or displayed in a readily understandable format. Queries against a standard relational database unfortunately do not perform satisfactorily to accommodate a large number of simultaneous clients (as is typically experienced by a website server), or to present a sophisticated user interface or display, even for a small number of users. Consequently, according to another aspect of the present disclosure a product information server is provided which enables the information to be traversed and compared with query terms quickly.
According to this aspect of the disclosure, the object information is compiled into a compact, flat file format. The compact file format takes each character string for each piece of information and “tokenizes” it by assigning to it a unique integer. Although it is possible that the token may be arbitrarily chosen, according to the preferred embodiment of the disclosure the value of the integer assigned to the character string is equal to the offset of the location of the string in the data block. In this way, each token points to the beginning of its corresponding character string in the block. Consequently, the server is able to go immediately to the location of the start of the character string in the block based on the value of the token, so as to retrieve the string for display.
The character strings and unique integer values are placed in a look-up table 4100 as shown in FIG. 4B . Each character string is stored in a field 4102 which is associated with a unique integer value field 4101 . In the example, the integer 2 identifies the character string “Pentium®”, while the character string “CPU” is identified by integer 6598 . Each of the tokens representing each product in the database is then written into a file 4001 having a format as shown in FIG. 4A .
Conventionally, information to be presented to a user in a table format is arranged in a file in product sequence order, with each product name being followed by all of the attribute data associated with the product. When organized into a table format, each row represents a specific product, each column represents a specific attribute of the product, and each intersection of row and column contains a token for a character string corresponding to the attribute value. Such a file is sometimes referred to as being in “row major” format. When carrying out a parameter search on such a file, a great deal of irrelevant information is retrieved from the database (usually on a hard disk) and placed into memory. This has the double negative effect of using up the memory resources of the system and making the search take longer because of the need to scan through irrelevant information. For example, if a search is desired for laptop computers having a minimum amount of memory, according to the conventional database file format all attribute information is retrieved for all laptop products, in addition to the attribute search term specified. Thus, the search requires a substantial amount of time because all the irrelevant attribute information pertaining to each product in the database must be traversed in the course of identifying the pertinent attribute information specified by the user.
According to the disclosure, instead of arranging information in “row major” format, the product information server extracts the information from the native database and organizes it in “column major” format, wherein all attribute values of like attributes are arranged in sequence adjacent to each other. For example, all monitor display sizes are arranged next to each other, then all display resolutions arranged next to each other, then all hard disk sizes are arranged next to each other, then all processor clock speeds are arranged next to each other, etc. In this way, an attribute-based search may be performed much faster, by allowing the search to jump immediately to the start of the location of the relevant attribute specified by the user, and to retrieve all the relevant attribute information and only the relevant attribute information into memory to perform the search.
As shown in FIG. 4A , N PROD 4003 is an integer identifying the number of products in the file, N ATTR 4005 is an integer identifying the number N of attributes in the file. Each of the N attributes is represented by an attribute value integer “ATTR I mval” 4007 . The integer 4007 identifies the attribute. Each of the values in turn are identified by the “val I prod I” integers 4009 . Additionally, an attribute may be multivalued, such that the integers 4007 would correspond to an offset for an “mval list I” 4013 , which is an n-tuple, each of the n integers in the n-tuple pointing to a separate value of the attribute in the look-up table.
In a query, the file 4001 is traversed and all corresponding integers are retrieved. The associated character strings are then obtained from the look-up table 4100 and are appropriately formatted for display at the client.
As shown in FIG. 5 , the present disclosure provides a system 400 to implement the method of the disclosure to achieve the desired information display. In particular, system 400 comprises a server 410 that contains a storage device 420 for storing the desired vendor and product information. The server also contains a database engine 425 that adds collected information data to the storage device 420 and creates an output using the information stored in the storage device 420 .
The system 400 further includes a user's processing device 450 , such as a personal computer, and a connection 440 to allow the transfer of information between the server 410 and the processing device 450 . The processing device 450 includes a web browser 460 which provides an output to a display device 480 , such as a display monitor, and which accepts an input from an input device 470 , such as a keyboard or mouse.
In addition to the storage device 420 , the server 410 also optionally contains scraper programs 430 for the collection of data, as previously described.
The connection 440 is preferably a distributed network, such as the Internet, to allow a plurality of users to have simultaneous connection to the server.
FIG. 6 illustrates a screen shot of a website containing information on a product specified by a user as being of interest and vendors that sell that product. The website displays a name 10 for the product, a list price 30 , a composite user rating 40 based upon user ratings 45 in various categories 46 , a ranking 50 of the product in a class 55 of similar products, features 60 of the product, vendors 70 who sell the product, a price 80 for the product at each of the vendors' sites, user reviews 90 , and access to industry reviews 100 .
The name 10 is generally the manufacturer and model name but may be any identifier used for the product. The name 10 may be carried over from a third-party site or arbitrarily created at the website.
Similarly, the list price 30 is a number either given by the product's manufacturer or distributor or arbitrarily assigned by the website. The list price 30 alerts a user to the relative value of the product to allow better evaluation of the prices 80 offered by the vendors 70 . For instance, a computer selling for $500 is generally a good value if its list price is $1000, but not if the list price is $100. While the list price is generally higher than the actual price offered 80 by the vendors, this is not necessarily true, especially with rare, collectable items that may sell for much more than the list price.
The consumer product rating is formed, as described above, by surveying a plurality of users and combining these ratings.
As illustrated in FIG. 6 , some of the vendors 70 may be identified prominently, so as to encourage the user to patronize these vendors. As further illustrated in FIG. 6 , the website may optionally display any of the following: an image 20 of the product; a rate-it-now display 110 to allow the user to add a user review 90 and rating 40 of the product; a helpfulness evaluation 120 of the information; complementary products 130 that may be purchased along with the desired product; or a discussion link 140 to Usenet and/or other discussion areas regarding the product and/or related products.
Because of limitations on the size of the display, the website may not all display of the product and vendor information at the same time. The information is then nested, and the consumer may access this information by performing an action such as clicking a pointing device (mouse) over one of the displayed objects. For example, to find more information about one of the vendors 70 , the user selects the vendor to be redirected to a sub-page, as shown in FIG. 7A . The sub-page then provides more specific information for the vendor 70 , such as the vendor's address 71 ; telephone number 72 ; shipping practices 73 ; payment policy 74 ; return policy 75 ; a rating of the vendor 76 ; reviews of the vendor 77 ; and an indication 78 of the product name 10 , product prices 80 , and availability 150 .
The website may allow the user to select a product by reviewing a list of product categories 180 , as illustrated in FIG. 7B . One the user selects a category of products, the user may then select a particular product from a product list 190 from that class, as shown in FIG. 7C . Alternatively, the product list 190 may be formed by displaying the highest rated products 170 .
As illustrated in FIG. 8 , the website may further contain a decision guide 300 which asks the user general questions 310 such as the user's age, occupation, and hobbies. The decision guide then uses this information to select a product for the user. This feature is helpful for a user who may not have sufficient technical knowledge to select a product based upon the features of that product. In this way, the product list 190 is formed to meet the specific needs of the user.
For a user who understands the product features, the website may assist the user in identifying products containing user-desired features. A narrow-your-choices option 160 of FIG. 6 redirects the user to a display, such as illustrated in FIG. 9 . The narrow-your-choices option 160 asks the user to specify or select one or more feature options 161 for the product of interest. After the user has selected the desired feature options 161 , the user sends a “display products” instruction 162 to the website to display the products meeting the chosen feature options 161 . In this way, the product list 190 can be formed with products having the desired features.
The disclosure thus having been described, it will be apparent to those skilled in the art that the same may be varied in many ways without departing from the spirit and scope of the disclosure. Any and all such modifications are intended to be included within the scope of the following claims. | Systems and a method for retrieving and normalizing product information are described. The system identifies a threshold overlap value defining a value of attribute overlap that triggers a merging of item records. The system accesses a first item record and a second item record stored in a network database, the first item record and the second item record each comprising one or more attributes. The system identifies at least one attribute that is common in both the first item record and the second item record. Finally, the system merges the first item record and second item record into a single item record in response to a level of the at least one attribute identified as being common transgressing the threshold overlap value. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to oscillating systems and more particularly to rapid start-up and stabilization of an oscillating system while maintaining minimum operational power consumption. The invention may be used in an electronic watch, electronic calculator, and analog and digital circuits.
To maximize battery life it is necessary to reduce the required power to operate a crystal oscillator. As the power is reduced towards the absolute minimum, the required time for the oscillator to start increases, requiring in some cases as much as many seconds. The long start-up time can be a considerable manufacturing hindrance and inconvenience.
SUMMARY OF THE INVENTION
In accordance with the present invention, an oscillator is operated at a relatively high gain immediately after power is applied and until the oscillator is stabilized and running, after which the gain is reduced and the oscillator is operated under the normal preferred low power conditions. In a preferred embodiment a power-up pulse sets a latch which increases the gain of the oscillator circuit by modifying the oscillator so that it starts quickly. Once the oscillator is running, it activates a prescaler. After several cycles of clock inputs to the activated prescaler, an output from the prescaler resets the latch, thus removing the modifiers from the oscillator circuits, returning it to the normal preferred low power operational conditions.
The type of modification to the oscillator may vary depending upon the IC technology used. In a preferred embodiment utilizing I 2 L circuits, the modification is comprised of injection of more current (than in the normal mode) into the oscillator amplifier.
In an alternative embodiment utilizing CMOS circuits, the modification is comprised of switching in larger transistors or shunting out the series output resistance or both during start-up.
In an additional embodiment, a manual reset of the rapid start latch may be utilized. Thus, the latch would be set when the battery is inserted, and the user would reset the latch by pressing a control button as part of his operating procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
Novel features believed to be characteristic of this invention are set forth in the appended claims. The invention itself, however, as well as other objects and advantages thereof may best be understood when read in conjunction with the following detailed description of illustrated embodiments by reference to the accompanying drawings in which:
FIG. 1 is a pictoral view of an electronic watch in which oscillator systems embodying the invention may be used advantageously;
FIG. 2 is an elevational view of the electronic watch of FIG. 1 taken along the line 2--2 of FIG. 1;
FIG. 3 is a partial block diagram (partial schematic) of an oscillator system embodying the present invention;
FIGS. 4a-4e is a schematic diagram of an I 2 L embodiment of the present invention of FIG. 3; and
FIGS. 5a-5b are schematic diagrams of alternative CMOS embodiments of the present invention of FIG. 3.
DETAILED DESCRIPTION
Referring to FIG. 1, an electronic watch in which oscillator systems embodying the invention may advantageously be used is shown. A housing 10 is connected to a band 13. A display 11 is seated within the housing 10, with the display 11 being visible through an aperture at the top of the housing 10. A transparent cover 12, overlies the display 11 within the housing 10, the cover 12 providing mechanical and electrical insulation from damage by introduction of foreign objects at the top surface of the housing 10.
Referring to FIG. 2, an elevational view in section of the watch in FIG. 1 is taken along the line 2--2 of FIG. 1. The housing 10 contains a battery compartment 25 in which a battery power source 24 is contained to provide power to the electronic watch system. The battery 24 is connected to an integrated circuit connector 26 which provides for connection of the battery to an integrated circuit 21. A circuit board substrate 20 overlies the battery compartment 25 within the housing 10. The integrated circuit chip 21 is mounted upon and connected to the substrate 20. A protective cover 23 is mounted atop of the integrated circuit chip 21 and connected to the substrate 20. The display 11 is mounted atop the substrate 20 and protective cover 23 within the housing 10. The transparent cover 12 is then mounted on top of the display 11 as previously described with reference to FIG. 1. A first control button 27, a second control button 28, and a third control button 29 are connected to the substrate 20 and therefrom to the integrated circuit chip 21 to allow for user input communication to the integrated circuit chip 21. Referring to FIG. 3, the oscillator 120 is comprised of a selectable gain amplifier 102, a crystal 103, modifier means 109, and capacitors 104 and 105. The output of the oscillator is connected to the input of the prescaler 100. An output of the prescaler 100 is connected to a reset input of a latch 101. A set input of the latch 101 is connected to a node between a resistor 111 and a capacitor 110. The resistor 111 is connected to Vss supply voltage and to the capacitor 110. The capacitor 110 is connected to a Vdd supply voltage and to the resistor 111. The purpose of the resistor 111 and capacitor 110 is to output a pulse of short duration when the battery voltage is first supplied. This short duration voltage pulse sets the latch 101, and the latch 101 when set outputs a signal 121 connected to the modifier means 109 so as to cause an increase in the gain of the amplifier 102. The increase in the gain may be in the form of increased current from a current regulator, as in the case of an I 2 L oscillator or it may be in the form of modifying the sizes of the transistors of the oscillators themself so as to increase the current to and gain of the oscillator, such as in the case of I 2 L, CMOS, or bipolar oscillator.
Two techniques may be used for increasing the loop gain of the oscillator system: (1) to either increase actually or effectively the size of the amplifier transistors, or (2) to reduce the series resistance between the amplifier output and the oscillator output. Many elements are involved in the loop gain. The amplifier transistors determine the inherent gain as well as the required bias voltages to be applied to the amplifier. Another element determinative of gain is the resistance in series with the crystal 103. Any series resistance between the amplifier transistor and the crystal-capacitor network impedes and reduces the signal levels passing through the oscillator output.
Referring to FIG. 3, when the battery voltage is first applied, capacitor 110 and resistor 111 provide a pulse voltage output at node 112 connected to the S input of the latch 101. When the battery voltage is first applied, there will be no initial charge on the capacitor 110, that is, there will initially be zero volts across the capacitor. When the battery is connected to the oscillator system, the battery side of the capacitor 110 will immediately rise to the battery voltage. Since there is initially no charge or voltage across the capacitor, the resistor side of the capacitor 110 will also immediately rise to the battery voltage, and then, as the capacitor is charged, the resistor side of the capacitor 110 will charge toward the ground voltage. The voltage on the set input S of the latch 101 will have a positive voltage pulse present for a short duration of time proportional to the selected values of the resistor 111 and capacitor 110. By proper value selection of the capacitor 110 and the resistor 111, the pulse duration may be made more than adequate to set the latch. An additional concern is to assure that the battery supply voltage is connected to the latch circuitry quickly during power up so as to allow the latch to be responsive to the set input. Therefore, it is necessary to maintain a positive voltage on the S input long enough to set the latch 101 to a proper On state condition. Additionally, during power up, an inactive, low voltage level, reset signal must be applied to assure proper latch operation. A form of preconditioning on the output of the prescaler 100 is required, to assure that the reset output from the prescaler 100 connecting to the reset input of the power up latch 101 is at an inactive low voltage level during power up. One technique of assuring an inactive low voltage level reset signal during power up is to use the set S input to the latch 101 to simultaneously clear out the latter or all stages of the prescaler 100, as shown in FIG. 4b and FIGS. 5a-5b, so as to assure that the reset output of the prescaler 100 is at a low voltage inactive level as long as the set input to the latch 101 is at an active level. When the latch 101 is set, an output from the latch 101 is connected to the modifier 109 which causes the oscillator system to be modified for fast start up operation. The modification enables means for increasing the gain of the amplifier such that the oscillator will start rapidly. Once the oscillator is started, the prescaler 100 will be clocked by the output of the oscillator, and after a certain number of pulses, determined by the length of the prescaler 100, the output of the prescaler 100 will go high, which in turn is connected to the reset input R of the latch 101, and clears the latch 101, causing the output of the latch 101 to switch to an off state, thereby disabling the modifying means 109 of the oscillator system 120 thereby decreasing the gain of the amplifier 102 to a predetermined low level gain mode. The oscillator 120 then returns to a sustaining condition of low power, low current drain mode. Alternatively, the latch 101 may be reset by a manually supplied input stimulus applied to node 113 and connected to the reset input R of the latch 101 which decreases the gain of the amplifier 102 to the predetermined low level gain mode.
At the resonant frequency of the crystal 103, oscillation will occur only when the total loop gain of the oscillator system is greater than one. If the gain of the system is less than one, then the gain for the amplifier in the system must be increased to compensate for losses in the other circuitry of the system. One way to make the gain greater is to make the transistors in the amplifier physically larger especially in the case of MOS designs. Another more direct way to increase the gain of the amplifier in the oscillator system in the case of bipolar (I 2 L) designs is to increase the collector/emitter (source/drain) current of the transistors in the amplifier.
Referring to FIG. 4d, increasing the collector/emitter current of amplifier transistor Q34 increases the gain for the amplifier. Transistors Q35 and Q37 are parmetrically and physically matched to the transistor Q34 so as to achieve efficient coupling between the transistors Q34, Q35 and Q37 which form the body of the amplifier 102. By increasing the current through Q34, the current through Q35 and Q37 is increased proportionately. Referring to FIG. 4e, the current regulator 200 provides the current supply to the oscillator 120 of FIG. 4d. By increasing the current output from the regulator 200, the current to transistors Q29 to Q32 of FIG. 4d is increased. Referring back to FIG. 4d, a current division network circuit is formed by transistors Q29 through Q32. The ratios of the current division are established to provide for an optimum relationship between transistors Q34, Q35 and Q37. To increase the current in Q34, the current to the entire oscillator must be increased so as to still maintain the proper current ratios with respect to the transistors Q35 and Q37. This is accomplished by increasing the current output from transistor Q47 of the current regulator 200, as shown in FIG. 4e. In order to minimize the current drain on the battery or power supply in the system, the oscillator current must be minimized during normal operation. There is a minimum point to which the oscillator current can be reduced. Below that minimum point there is inadequate gain for the oscillator to sustain resonant oscillation. On the other hand, the oscillator should have adequate operational current margins, particularly with regard to turning on quickly and sustaining oscillation. In many applications, for instance in watch circuits, the oscillator can sustain oscillation at very low currents because the Q of the crystal in the oscillator is quite high. However, if the current is reduced to the absolute operational minimum so that oscillation is still mantained, start-up of oscillation will be very slow, which is undersirable and inconvenient. The current to the oscillator 120 must be supplied at a greater level to start up oscillation quickly than the minimum current required for oscillation. However, the start up current may be unacceptable as an operational current due to the excessive power drain. In the present invention, optimization is achieved by switching in higher current during start up of the oscillator, and then reducing that current to a minimum operational level to sustain oscillation thereafter. This effects fast oscillator start up while minimizing the overall current drain because most of the operational life of the battery is working at a minimum current level.
Referring to FIG. 4e, the switching of the currents is accomplished through the use of current regulator transistors Q54, Q55, resistor R31, and gate 4835. Normally, the current for the oscillator is supplied from a current regulator 200 by transistor Q47. The transistor Q47 is a pnp transistor which divides the current from the battery in combination with transistors Q44, Q45, Q46 and Q48 to provide current to the various portions of the total circuit. As shown in FIG. 4e, the current is divided one of five ways. Q44 supplies current to a regulating circuit which is formed by transistor Q52, resistor R29, transistor Q51 and associated circuitry. The voltage drop across R29 is detected by Q51 and Q52 to maintain a constant current output through the transistor Q44. The current through Q45, Q46, Q47 and Q48 will be proportional to that in Q44 due to physical sizing similarity and design. The current output from Q47 is approximately 1/5 of the total current during normal operation. Thus, if the battery provides a total of 4 microamperes then the oscillator would be operating in the low gain mode 1/5 of the total current, or 0.8 microamperes during normal operations.
When the battery is first connected to the integrated circuit, a power clear latch 101 is set, and the latch 101 outputs a signal SCLR, which is an active low output connecting to and turning on the pnp transistor Q55, which then, in turn, supplies current to npn transistor Q54, so as to turn on transistor Q54. Since the collector of Q54 is connected to resistor R31 and therefrom directly to the battery, additional current is supplied to the oscillator 120 in parallel to that supplied from transistor Q47 in the high gain mode. This additional current may be significantly greater than that supplied by Q47, on the order of 50 to 75 microamps. With this significantly increased start up current supplied to the oscillator 120, the gain of the amplifier 102 will be substantially greater than the normal mode oscillation current, and will be more than sufficient to quickly turn on the oscillator within 1 second, typically less than 0.5 seconds. If the transistors Q54 and Q55 had not switched in this additional start up current, the normal operational current of 0.8 microamperes would start up the oscillator in a much greater time than 1 second, and in the limit where operation of the oscillator is attempted at as low as 0.5 microamperes, the turn on time may be on the order of 5 to 15 seconds. In one embodiment, the SCLR signal is removed by pressing the command button 28, which resets the power clear latch 101, switching the SCLR signal to an inactive high level which turns the pnp transistor Q55 to an off state. When Q55 turns off, the gate 4835 pulls the base of transistor Q54 to a low level turning Q54 off, such that the current for the oscillator 120 is supplied solely by Q47 which is at the sustaining current of 0.5 to 0.8 microamperes in the preferred embodiment. This provides the sustaining current to maintain oscillation once the oscillator has stablized at resonant frequency.
When a battery is first inserted into the watch, the user may check to verify that the display is activated by pressing the command button 28. The display cannot be activated unless the oscillator 120 is running so that the oscillator 120 has achieved a stablized state by time the additional power up current is removed.
An alternative method of clearing the power clear latch 101, and thereby removing the additional start up current, is to use an output from the prescaler 100 to reset the latch 101. The prescaler 100 will not be activated unless the oscillator is running. If an output of the prescaler 100, adequately far down the divider chain of the prescaler 100, is chosen as a reset signal to reset the latch 101, the oscillator 120 will have been operational for many cycles prior to the reset signal, and the oscillator 120 will have achieved a stablized state. Thus, there would be no operating problems upon the removal of the additional start up current. This technique provides a means of automatically clearing the latch 100 without having to press the button 28. For example, an auto/reset signal could be tapped from FF306 or FF207 of the prescaler 100 as shown in FIG. 4b to reset the power clear latch after 64 or 128 cycles, respectively, thereby deactivating the SCLR signal thereby removing the additional power up current from the oscillator 120.
Referring to FIGS. 5a-b, the blocks of FIG. 3 are shown in detailed schematics of CMOS embodiments, with corresponding blocks of FIG. 3 shown with corresponding numbers in FIGS. 5a-b. Referring to FIG. 5a, the amplifier 102 for the oscillator 120 is comprised of N-channel transistors, 207, 210, 204 and 206, and P-channel transistors 203, 205, 211 and 208, and resistors 201 and 202. The basic amplifier is formed by N-channel transistor 207 and P-channel transistor 208. Transistor 205 and transistor 206 have large length to width ratios, being long skinny devices used for the purpose of biasing the amplifier transistors 207 and 208 into a linear operating range. Transistors 205 and 206 have large length to width ratios to achieve very high impedence, typically in the range of 10-20 megaohm region, in order to prevent loading of the crystal 103. The transistors 205 and 206 are in parallel with each other, forming a resistive element connecting at a node 215 joining between the drains of transisitors 207 and 208. The gates of transistors 207 and 208 are connected to a node 214. Transistors 210 and 211 each have a gate connected to the node 215 and form a buffer between the output of transistors 207 and 208 at the node 215 to the input of the prescaler 100 at a node 216. The resistors 201 and 202 are connected in series between node 215 and an oscillator output node 240. In addition, there is an input capacitor 104 connected to oscillator input node 241. The crystal 103 is connected between the oscillator input node 241 and the oscillator output node 240. A trimmer capacitor 105 is connected to the output node 240 and to ground. The capacitor 105 forms a load for the crystal in conjunction with the capacitor 104. The capacitor value of 105 may be changed, allowing the system to be fine tuned to the preferred resonant frequency. The addition of transistors 203 and 204 for the oscillator system provide a means for selectively shunting out a portion of the amplifier series output resistance as formed by resistor elements 201 and 202. As shown in FIG. 5a, when enabled, transistors 203 and 204 will shunt out resistive element 202, which in effect increases the gain of the amplifier 102 in the oscillator system 120. Resistors 201 and 202 are in the circuit to minimize the current drain of the oscillator in the normal oscillation mode, limiting the charging current for the capacitor 105. When the resistor 202 is shunted out of the oscillator circuit, the N-channel transistor 207 will charge the capacitor 105 towards the battery voltage, during one-half of the oscillator clock cycle and P-channel transistor 208 will discharge capacitor 105 towards ground during the other one-half cycle. This charge current is far more than is needed to maintain the oscillation of the oscillator system once stable oscillation has been achieved. Consequently, there is a considerable amount of current, and power which would be wasted if the oscillator were continuously operated under these conditions. Therefore, as a means of reducing the current to minimum operational levels the series output resistor 202 is re-inserted, in effect, between the transistor amplifier 102 and the oscillator output node 240 during sustained normal operation of the oscillator in order to limit the amount of current charging the capacitor 105. A consequence of adding series output resistors is that there is a resistance in series with the resonant circuit which consumes energy from the amplifier, and which is never effectively used in the resonant oscillation network. Thus, there is a compromise between inserting enough series resistance to reduce the current usage, and between not inserting too large a resistance so as to reduce the energy output from the oscillator to a level which would result in oscillator stoppage or lack of oscillator startup. To minimize the current drain, it is necessary that the resistor combination 201 and 202 be as large as possible, but in order for the oscillator to turn on quickly it is necessary that the series resistance be as small as possible. The present invention allows utilization of a large resistance to minimize current during sustained oscillation, and provides a means to greatly reduce the series resistance to a much smaller value during an initial start up period so that the oscillator will start oscillation quickly. The decrease in series resistance is accomplished by effectively shorting out one of the resistors in the series resistance path, in the present case resistor 202, by using parallel transistors 203 and 204 to shunt the resistor 202. A parallel transistor combination is used, P-channel 203 and N-channel 204, such that equal conduction is achieved in both directions, allowing current to flow in both directions so as to allow full oscillation. Transistors 203 and 204 are turned on by the output of latch 101, and more specifically, by the output of NOR gates 232 and 233 which form the cross coupled latch 101. One input of NOR gate 232 is connected to a power up clear signal PUC which is output from an inverter 231. The PUC signal may also be connected to a clear input of a divide by two flip-flop 221 forming the final stage of the prescaler 100, and may be connected to other portions of the circuit as are required to be cleared during the initial application of power. The input of inverter 231 is connected to the output of an inverter 230. The input of the inverter 230 is connected to the junction 260 of the connection of capacitor 110 and the drain of N-channel transistor 111. The transistor 111 corresponds to the resistor 111 of FIG. 3, having formed a resistor with an appropriately sized transistor to get the desired resistance. When power is first applied, a PUC pulse will be initially high, at zero volts, and will then return to a low, minus VSS, voltage. When PUC is high, it sets the cross coupled latch 101. This forces the output of NOR gate 232 to go to a low voltage level, which is connected to the gate of the P-channel transistor 203, which turns on transistor 203, thereby shunting resistor 202. Simultaneously, NOR gate 233 is turned on, causing its output to go to a high voltage level, which is connected to the gate of N-channel transistor 204, turning on transistor 204 and shunting resistor 202. The transistors 203 and 204 are thus both enabled simultaneously, providing a bilateral gate to shunt resistor 202, thereby increasing the gain of the oscillator system by decreasing the limiting resistance between the amplifier output at the node 215 and the oscillator output at the node 240. The node 215 is connected to the gate of N-channel transistor 210 and P-channel transistor 211 which forms a buffer. The output node 216 of the buffer is connected to the clock input of the prescaler 100, and more specifically to the clock input of a first stage 220 of the prescaler 100. The first stage 220 of the prescaler 100 plus the divide by two flip-flop 221 of the prescaler 100 correspond to the prescaler 100 as shown in FIG. 3. Prescaler 100 functions have been separated into a first stage prescaler section 220 in which, in the present embodiment, it is immaterial as to whether the stage 220 has a clear input, and a latter stage 221 that does have a clear input. The Q output of flip flop 221 is connected to the reset input of the latch 101. The Q output of flip flop 221 is required to be at a known state during power-up start up so that a PUC pulse can set the cross coupled latch 101. In order to set the latch, there must not be a conflicting reset signal when the PUC set signal is applied. That is, because the Q output of 221 is connected to one of the inputs of NOR gate 233, the Q output of 221 must be at a low level when power is initially applied in order to prevent the cross coupled latch 101 from being reset at the same time as an attempted setting of the latch is occuring with the application of the PUC pulse. Therefore, the PUC pulse is also connected to the clear input CLR, of flip flop 221 so as to force its Q output to an inactive low state during a high level state of the PUC pulse so as to allow the PUC pulse to set the cross coupled latch 101 without interference. After a short period of time, as determined by the time constant derived from the resistance of transistor 111 and capacitor 110, the PUC pulse returns to a logic zero state, minus VSS, enabling flip flop 221 to change states in response to the reset signal which is responsive to a clock pulse from the output of the first stage 221 of the prescaler 100. The clock pulse output from the first stage 220 occurs after counting down a predetermined number of pulses of clock output from the oscillator system 120, providing adequate time for the oscillator to have achieved a stable operating state before the cross coupled latch 101 is reset. When the latch is reset, its output causes the transistors 203 and 204 to turn off, removing the shunt from across resistor 202, thereby returning the output resistance to its normal sustaining value, and reducing the current drain on the battery while maintaining oscillation. Alternatively, the latch 101 may be comprised of cross coupled NAND gates, or of any alternative set-reset latch circuitry arrangement.
Referring to FIG. 5b, an alternative embodiment of the oscillator system with FIG. 5a is shown with corresponding elements and functional blocks identically numbered. FIG. 5b is identical to FIG. 5a with the exception that the change in the effective gain of the amplifier is not accomplished by changing the value of the output resistance, resistors 201 and 202 of FIG. 5a. Instead, there is a fixed resistance in the output formed by resistor 309 between amplifier output node 310 and oscillator output node 311. The gain of the amplifier is modified by effectively increasing the size of the amplifier transistors 303 and 307 by switching in a parallel shunt amplifier comprised of transistors 302 and 306. The transistor 302 is connected in parallel with the transistor 303, and the transistor 306 is connected in parallel with the transistor 307, with the drains and the gates of the transistors 302 and 306 connected in parallel with the drains and gates of transistors 303 and 307, respectively. When the transistors 301 and 308 are turned on responsive to the output of the latch 101, the sources of transistors 302 and 306 will be effectively connected in parallel with the sources of transistors 303 and 307, respectively. That is, when the transistors 301 and 308 are turned on, the sources of transistors 302 and 306, respectively, will be connected to the VSS and ground power supply rails, respectively. Transistors 304 and 305 correspond to transistors 205 and 206 in FIG. 5a, and provide a very high impedance bias voltage across the amplifier transistors 302, 303, 306, and 307. The transistors 301 and 308 will be turned on initially when the power is supplied and will subsequently be turned off when the prescaler flip flop 221 outputs a reset pulse so as to clear the latch 101, in the manner as described with reference to FIG. 5a. When this occurs, the transistor 301 is deactivated by the output of NOR gate 233, and the transistor 308 is deactivated by the output of NOR gate 232.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment, as well as other embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention. | A rapid start oscillator latch circuit for avoiding long start up time while maintaining minimum operating power for a crystal oscillator in an electronic watch. The oscillator is operated at a relatively high gain immediately after power is applied and until the oscillator is running, after which the oscillator is caused to operate under the normally preferred conditions. A power up pulse sets a latch and the latch is reset by either a pulse from the prescaler or a manual input. When the latch is set, the oscillator circuit is modified for quick start-up. After the oscillator is running, it activates the prescaler, and after several cycles of clock inputs to the prescaler, an output from the prescaler or a manual input resets the latch and the oscillator is returned to its normal operating condition. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to improved apparatus for measuring features of vessels. More specifically, the present invention provides a guidewire having a plurality of radiopaque markers useful for sizing the length of a lesion, e.g., within coronary arteries.
BACKGROUND OF THE INVENTION
[0002] Patients suffering from atherosclerosis may undergo angioplasty, a procedure involving the use of a balloon-tipped catheter that dilates occluded vessels by compressing atherosclerotic plaque against the vessel wall. Further benefits may be realized if the patient additionally undergoes stenting, a process involving the deployment of tubular prostheses that hold the occluded vessel open and help restore adequate blood flow to the region.
[0003] Guidewires having relatively small diameters and flexible coiled tips may be used to transluminally navigate the tortuous anatomy and locate lesions prior to insertion of the catheter. Additionally, guidewires may be used to size vascular lesions prior to performing interventional procedures to determine the size of the angioplasty balloon or stent to be used in treating the lesion. Accurately assessing the three-dimensional size of a lesion requires a physician to account for lesions that partially extend into a third dimension not visible on a two-dimensional fluoroscopy screen.
[0004] Several previously-known guidewires have been introduced for use in positioning balloon catheters within a vessel and/or sizing vessel characteristics. U.S. Pat. No. 5,174,302 to Palmer describes a guidewire having an initially uniform core section that tapers inward along a distal segment. The distal segment is surrounded by a flexible spring tip that is banded to define portions that are highly radiopaque and portions that are much less radiopaque. The radiopaque bands provide a reference for the physician with regard to positioning the guidewire within the cardiovascular system when used in conjunction with an x-ray imaging system.
[0005] The previously known device described in the foregoing patent has several drawbacks. First, despite having a tapered distal segment of core wire, the overall diameter of the guidewire is substantially equal along its length because the radiopaque-banded spring that wraps around the distal segment adds to the core wire diameter and negates the tapering effect. It therefore would be beneficial to provide a guidewire having a reduced distal diameter that facilitates use in smaller vessels.
[0006] Another drawback associated with the device described in the Palmer patent is that the radiopaque markers are disposed in the coiled spring. While it may be desirable to simultaneously provide the radiopaque guidewire within the stenosis, e.g., as a reference point throughout a stenting procedure, the Palmer device may be difficult to track in real time under fluoroscopy. This is because a distal coil is typically advanced through and disposed distal to the stenosis, not disposed within the stenosis itself, which may make the coil difficult to view throughout the procedure.
[0007] Cook Incorporated offers a measuring guidewire under the tradename GRADUATE®, for use in sizing vessel lumens prior to angioplasty and other interventional procedures. This product has six distal gold markers spaced 1 cm apart and four proximal markers spaced at 5 cm intervals disposed on the distal end of the guidewire.
[0008] One drawback associated with the Cook guidewire is its relatively large diameter. The guidewire diameter is 0.035 inches, and therefore is not suitable for use in coronary arteries. Additionally, the gold marker bands are affixed to the outer diameter of the guidewire, and result in an increased diameter that forms a potentially uneven surface.
[0009] In view of these drawbacks of previously known guidewires, it would be desirable to provide a guidewire having radiopaque markers suitable for accurately sizing the length of a feature, e.g., a lesion, within a vessel.
[0010] It also would be desirable to provide a guidewire having radiopaque markers that is suitable for insertion into smaller vessels, e.g., coronary arteries.
[0011] It still further would be desirable to provide a guidewire having radiopaque markers that form a substantially smooth surface along the guidewire such that the bands do not increase the diameter of the guidewire or create a jagged surface.
SUMMARY OF THE INVENTION
[0012] In view of the foregoing, it is an object of the present invention to provide a guidewire having radiopaque markers suitable for accurately sizing the length of a lesion within a vessel.
[0013] It is also an object of the present invention to provide a guidewire having a plurality of radiopaque markers that is suitable for insertion into smaller vessels, e.g., coronary arteries.
[0014] It is further an object of the present invention to provide a guidewire having a plurality of radiopaque markers that form a substantially smooth surface along the guidewire such that the bands do not increase the diameter of the guidewire or create an uneven surface.
[0015] These and other objects of the present invention are accomplished by providing a guidewire having proximal and distal sections, and a plurality of radiopaque markers disposed along the distal section at predetermined intervals. The markers may be evenly spaced, for example, 10 mm apart, to enable a physician to accurately assess the size of a vessel feature, such as a lesion.
[0016] In a preferred embodiment, the guidewire comprises a core wire having a constant diameter proximal section and a tapered distal section having a plurality of radiopaque marker bands, preferably inset into indentations formed in the outer surface of the core wire to provide a substantially smooth surface. The guidewire also may include a lubricious surface, such as polytetrafluoroethelene (“PTFE”) disposed on its outer surface.
[0017] The guidewire of the present invention is manufactured by first masking the tapered distal section of core wire. The desired locations for the radiopaque markers then are selected, and the mask removed from the core wire at those selected locations to expose the core wire, e.g., by mechanically abrading or chemically removing the masking. A radiopaque material, preferably gold, then is deposited, such as by electroplating or vacuum deposition, on the distal section so that the selected, exposed regions of core wire are coated, while the mask prevents coating of other regions of the core wire. The mask then is removed.
[0018] Preferably, small indentations may be provided in the core wife, e.g., by grinding or chemically etching the core wire prior to deposition of the radiopaque material, so that no additional diameter is added to the guidewire. A lubricious coating then may be applied to further ensure a smooth, nonstick surface.
[0019] In an alternative embodiment, a sheath having a plurality of radiopaque markers disposed at predetermined intervals along its distal section may be used in combination with a traditional guidewire. In this embodiment, the traditional guidewire navigates the tortuous vasculature and crosses the lesion, then the sheath is distally advanced over the guidewire and the length of the lesion is assessed using the radiopaque markers of the sheath.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments, in which:
[0021] [0021]FIG. 1 illustrates a guidewire constructed in accordance with the principles of the present invention;
[0022] [0022]FIG. 2 illustrates the apparatus of the present invention positioned within an occluded vessel;
[0023] [0023]FIG. 3 describe a method of manufacturing apparatus in accordance with the present invention; and
[0024] [0024]FIG. 4 describe an alternative embodiment for measuring features of a vessel using a sheath having a plurality of radiopaque markers; and
[0025] [0025]FIG. 5 describe an alternative embodiment for measuring features of a vessel using a sheath in a rapid-exchange manner.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Referring to FIG. 1, guidewire 20 constructed in accordance with principles of the present invention is described. Guidewire 20 comprises core wire 30 having proximal section 22 , distal section 24 , and optionally, reduced diameter distalmost section 33 .
[0027] Along proximal section 22 , core wire 30 spans a length L 1 that comprises the majority of the overall length of guidewire 20 . Proximal section 22 may comprise a constant diameter d 1 , preferably 0.014 inches. Along distal section 24 , core wire 30 may taper inward gradually over a length L 2 . In a preferred embodiment, L 2 spans approximately 30 cm, and core wire 30 tapers uniformly to a final diameter d 2 , preferably about 0.005 inches.
[0028] Distal section 24 comprises plurality of radiopaque markers 28 . In a preferred embodiment, radiopaque markers 28 are spaced at equal intervals L 4 , for example, spaced apart 10 mm center-to-center, and the markers are 1 mm in length, as represented by length L 5 . Radiopaque markers 28 preferably consist of a gold layer that is electroplated or otherwise deposited onto core wire 30 according to manufacturing techniques described hereinbelow.
[0029] Guidewire 20 may further comprise a reduced diameter, distalmost section 33 having core wire diameter d 3 . Core wire diameter d 3 preferably is between about 0.001 and 0.003 inches. Coil 26 may be affixed to distalmost section 33 , such that the added diameter of coil 26 to reduced core wire diameter d 3 does not substantially increase the overall diameter of section 33 relative to diameter d 2 .
[0030] Referring to FIG. 2, guidewire 20 constructed in accordance with the present invention is depicted within a vessel V, for example, a coronary artery, having a lesion S that spans a length L 6 . Radiopaque markers 28 of guidewire 20 may be used to measure the length of lesion S under fluoroscopy since the markers are spaced at known, and preferably equal, intervals. For example, the appearance of four radiopaque markers 28 along the length of lesion S may translate into a lesion that is approximately 40 mm in length, assuming that markers 28 are equally spaced at 10 mm intervals, center-to-center.
[0031] Advantageously, several radiopaque markers may be provided along distal section 24 to better assess the characteristics of vessel V. The number of radiopaque markers is dependent on the overall length of tapered distal section 24 and the spacing intervals, L 4 . In a preferred embodiment, when tapered distal section 24 spans 30 cm and radiopaque markers 28 are equally spaced 10 mm apart, core wire 30 may accommodate approximately 30 markers.
[0032] Referring to FIG. 3, a method of manufacturing apparatus in accordance with principles of the present invention is described. Guidewire 20 comprises a length of core wire 50 having an initially constant diameter along proximal section 52 and distal section 54 . In a preferred embodiment, the initial diameter of core wire 50 is 0.014 inches. Distal section 54 of core wire 50 then is taper-ground such that its diameter gradually decreases, as shown in FIG. 3A. The taper preferably spans the distal 30 cm of core wire 50 and tapers from 0.014 to 0.005 inches.
[0033] Distal section 54 of core wire 50 then is coated using a masking 56 , for example, FEP (Fluorinated Ethylene-Propylene), silicone rubber, paint or another method, as shown in FIG. 3B. A distalmost section L 3 may be set aside, i.e., neither tapered nor masked, for the purpose of subsequently adhering a coil to the distal end of the guidewire.
[0034] Once distal section 54 is masked, the desired locations for the radiopaque markers may be selected. Mask 56 then is removed primarily at the selected locations, e.g., by scraping, abrading or chemically removing the mask at the selected locations, such that distal section 54 comprises exposed regions 58 and masked regions 60 , as shown in FIG. 3C. The dimensions and locations of exposed regions 58 are selected based on the desired positioning of the radiopaque markers, and are preferably 1 mm in length and spaced 10 mm apart, center-to-center.
[0035] A radiopaque material, preferably gold, then is deposited on distal section 54 at exposed regions 58 , for example, by electroplating or vacuum deposition, while masked regions 60 prevent coating of unwanted regions of core wire 50 . More preferably, exposed regions 58 may be reduced in diameter, e.g. by grinding or chemically etching, to form indentations prior to deposition of the radiopaque material. In this manner, the finished guidewire will have a substantially smooth outer surface, with the radiopaque markers substantially flush with the outer diameter of the core wire.
[0036] The remaining mask that covers the masked regions 60 then may be removed, either by use of dissolving chemicals or scraping the layer of masking. Upon removal of the remaining masking, distal section 54 of guidewire 20 comprises radiopaque markers 58 and non-radiopaque regions 59 of core wire 50 , as shown in FIG. 3D.
[0037] Distalmost section L 3 then may be flattened to form reduced diameter distalmost section 55 , as shown in FIG. 3D. The diameter of distalmost section 55 preferably is between about 0.001 and 0.003 inches. The reduced core wire diameter along distalmost section 55 allows coil 62 to be affixed to core wire 50 such that it does not substantially increase the diameter relative to the diameter provided at the distal end of section 54 , which is preferably 0.005 inches. Adhesive 64 , e.g., a solder or weld, may be used to affix coil 62 to section 55 of core wire 50 , as shown in FIG. 3E.
[0038] Coil 62 is configured to transluminally guide apparatus 20 through tortuous vasculature and into the selected vessel. Coil 62 preferably comprises a radiopaque material, e.g., platinum, to facilitate fluoroscopic guidance of the device. Coil 26 may overlap exclusively with section 55 of core wire 50 , or may extend distally beyond core wire 50 . Alternatively, reduced diameter distalmost section 55 may be omitted and coil 62 may be affixed directly to the distal end of section 54 .
[0039] A lubricious coating, preferably, e.g., polytetrafluoroethylene (“PTFE”) is applied to core wire 50 to ensure a smooth surface suitable for vascular insertion.
[0040] Although the marker bands of the present invention are illustratively depicted as circumferential bands, one of ordinary skill in the art will recognize that the sizes and shapes of the radiopaque markers may vary. For example, the radiopaque markers may comprise rectangular shapes, circular shapes, or irregular banded shapes that extend circumferentially around core wire.
[0041] Referring to FIG. 4, alternative apparatus and methods for measuring features of vessels are described. In FIG. 4A, sheath 80 having proximal and distal sections comprises plurality of radiopaque markers 82 disposed at predetermined intervals along the distal section. In this embodiment, the proximal end of sheath 80 communicate with proximal hub 84 . In a preferred embodiment, radiopaque markers 82 are spaced at equal intervals L 8 , for example, spaced apart 10 mm center-to-center, and the markers are 1 mm in length, as represented by L 7 . Radiopaque markers 82 preferably consist of a gold layer that is electroplated or otherwise deposited onto sheath 80 , according to manufacturing techniques described in FIGS. 3 B- 3 D hereinabove. Using such techniques, sheath 80 will have a substantially smooth outer surface, with radiopaque markers 82 being substantially flush with outer diameter d 4 of sheath 80 . Sheath 80 preferably comprises a material used in catheter construction, such as polyethylene or polyimide, and has a wall thickness of about 0.001 to 0.005 inches.
[0042] Sheath 80 of FIG. 4A is used in combination with a previously known guidewire having proximal and distal ends to measure features of a vessel. In a first method step, the distal end of traditional guidewire 90 is transluminally inserted into occluded vessel V. The distal end of traditional guidewire 90 preferably crosses lesion S and is ultimately positioned distal to lesion S, as shown in FIG. 4B. The distal end of traditional guidewire 90 preferably comprises coil 92 configured to transluminally navigate tortuous vasculature.
[0043] Sheath 80 , having an inner diameter slightly larger than the outer diameter of guidewire 90 , then is distally advanced over guidewire 90 and positioned within lesion S, as shown in FIG. 4C. Radiopaque markers 82 may be used to measure the length of lesion S under fluoroscopy since the markers are spaced at known, and preferably equal, intervals. Radiopaque markers 82 allow a physician to accurately assess L 7 , even though lesion S may partially extend into a third dimension not visible under two-dimensional fluoroscopy. Upon sizing L 7 , sheath 80 may be removed from the patient's body and an appropriately-sized angioplasty balloon catheter or stent may be delivered to the site of the lesion via guidewire 90 .
[0044] Referring to FIG. 5, apparatus and methods suitable for using a measuring sheath in a rapid-exchange manner are described. In FIG. 5A, sheath 100 comprises plurality of radiopaque markers 102 disposed at predetermined intervals along its length. Sheath 100 and radiopaque markers 102 are provided in accordance with manufacturing techniques described hereinabove. Sheath 100 is coupled to push wire 104 , e.g., a stainless steel wire or shaft having an outer diameter of about 0.014 inches, that is suitable for transmitting forces to sheath 100 . Push wire 104 preferably spans a substantially greater length than sheath 100 , and the proximal end of push wire 104 communicates with proximal hub 106 .
[0045] Sheath 100 of FIG. 5A may used in combination with a previously known guidewire having proximal and distal ends to measure features of a vessel. In a first method step, the distal end of traditional guidewire 110 is transluminally inserted into occluded vessel V. The distal end of traditional guidewire 110 preferably crosses lesion S and is ultimately positioned distal to lesion S, as shown in FIG. 4B.
[0046] Sheath 100 , having an inner diameter slightly larger than the outer diameter of guidewire 110 , is positioned over the proximal end of guidewire 110 . Push wire 104 then is advanced distally and causes sheath 100 to translate distally. Sheath 100 is ultimately positioned within lesion S, as shown in FIG. 4C, and radiopaque markers 102 may be used to measure the length of lesion S under fluoroscopy. The use of push wire 104 advantageously permits guidewire 110 to have a relatively small length, i.e., spanning approximately from the site of the lesion to a location just outside of the patient's body, such that the apparatus may be used in a rapid-exchange manner. Push wire 104 then may be retracted proximally to remove sheath 100 from the patient's body upon completion of the step of measuring the vascular feature.
[0047] While preferred illustrative embodiments of the invention are described above, it will be apparent to one skilled in the art that various changes and modifications may be made therein without departing from the invention. The appended claims are intended to cover all such changes and modifications that fall within the true spirit and scope of the invention. | Apparatus and methods for manufacturing a guidewire having a plurality of radiopaque markers are disclosed. In a preferred embodiment, the present invention provides a guidewire having a tapered distal section comprising a plurality of gold markers that are deposited on the guidewire at predetermined intervals, so that the outer surface of the guidewire is substantially smooth. The gold markers provide a fluoroscopic reference for positioning the guidewire and enable accurate sizing of vessel features, such as the length of a lesion. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of application Ser. No. ______, entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space And A Method For Installing The Alarm System,” and filed on ______, incorporated herein by reference in its entirety.
[0002] This application is also related to application Ser. No. ______ entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space For Indicating The Time Elapsed Since Intrusion Into The Enclosed Space And A Method For Installing The Alarm System,” and filed on ______, which is also a Continuation-In-Part of application Ser. No. ______, entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space For Indicating An Intrusion Into The Enclosed Space And A Method For Installing The Alarm System,” and filed on ______.
FIELD
[0003] The invention relates generally to systems and methods for intruder detection, and more particularly to notification of an intruder detection event.
BACKGROUND
[0004] Security systems for protecting buildings and other structures from intrusion are well known in the art. Such security systems generally include one or more alarms to notify others of an attempted or actual intrusion. These alarms can include audible signals and/or lights to indicate when a breach or attempted breach of a structure, such as the prying open of a door or window, has occurred. Such security systems can help to protect building owners and/or inhabitants from would-be intruders and actual intruders, such as burglars.
[0005] While many of these systems activate alarms to notify others of attempted or successful intrusions, these systems typically do not provide information as to whether there was merely an attempted intrusion, or an actual intrusion. Other systems may activate an alarm only to indicate an actual intrusion, but the alarm may deactivate or may be deactivated before the user of the system arrives upon the scene of the intrusion.
[0006] Furthermore, without sound, the alarms of known alarm systems are not easily noticeable from outside an enclosed space that was intruded upon. For example, the alarms of some systems are small, inconspicuous, and silent panels of information about an intrusion. Still other alarms that do provide sound do not clearly identify and locate the enclosed space that was intruded upon. Even though a loud alarm may be activated upon intrusion, the general location of the enclosed space being intruded upon may be unclear or ambiguous to observers outside the enclosed space.
SUMMARY
[0007] An alarm system with an indicator light that is external to an enclosed space for indicating an intrusion into an enclosed space and the specific location of the intrusion into the enclosed space, and a method of installing such a system, are claimed. For example, the alarm system will show that the intrusion occurred at a specific wall or corner of the enclosed space, and/or a specific door or a specific window of the enclosed space, and/or some other specific portion of the enclosed space.
[0008] The system can be purchased and installed inexpensively and easily, and it can provide a signal that does not expire over time, and is easily recognizable and locatable to the user of the system upon the user's arrival at the enclosed space or the structure. The signal indicates the specific location of an intrusion into the enclosed space, thereby providing information to others regarding where an intruder might be lurking and perhaps lying in wait, within the enclosed space, and/or possibly where the intruder might exit as well.
[0009] Upon detecting an intrusion into the enclosed space, the alarm system employs an indicator light that is located within an outer perimeter zone that surrounds the enclosed space. Upon activation, the indicator light emits light that extends beyond the outer perimeter zone of the enclosed space as an intrusion alert, thereby reducing the need of a user to enter the outer perimeter zone of the enclosed space to determine the specific location of the intrusion. The alert is conspicuous and easily recognizable to anyone who approaches the outer perimeter zone of the enclosed space for which the external light alert is activated. An indicator light alarm is typically also easier for people to trace to its source than is a sound alarm, particularly if the enclosed space is situated close to other enclosed spaces with which it could be confused. The enclosed space can be a building, or a particular section or room of a building, for example.
[0010] The alarm system provides alerts regarding the specific location of an intrusion into an enclosed space and/or structure, in addition to alerting a user of an intrusion event generally. The alert provides specific location information regarding only successful intrusions into an enclosed space, as opposed to mere attempted intrusions.
[0011] The indication of the specific location of an intrusion into an enclosed space is information that can provide an observer with insight as to the nature of the intrusion, without requiring that the observer enter the enclosed space, or even enter the outer perimeter zone of the enclosed space. An alert indicating the specific location of an intrusion can therefore be helpful in a variety of ways, such as enhancing the decision-making process for the user or others investigating the intrusion, regarding how they would respond to the alert.
[0012] For example, information regarding the specific location of an intrusion can affect the decision-making process of someone investigating the intrusion, such as the police, on how to further investigate or respond to the intrusion.
[0013] The present alarm system having an indicator light that is external to an enclosed space for indicating the location of an intrusion into an enclosed space, can benefit from use with the invention disclosed in patent application Ser. No. ______, entitled “Alarm System Having An Indicator Light That Is External To An Enclosed Space For Indicating The Time Elapsed Since An Intrusion Into The Enclosed Space And A Method For Installing The Alarm System,” and filed on ______.
[0014] In one embodiment, the invention is an alarm system for providing an indication of a specific location of an intrusion into an enclosed space, the enclosed space being surrounded by an outer perimeter zone, the indication enabling an observer situated outside the outer perimeter zone to learn the specific location of the intrusion, the alarm system comprising: at least one interior sensor located within an enclosed space, the interior sensor being configured to generate a specific intrusion location signal in response to an intrusion into the enclosed space; a light control system responsive to the specific intrusion location signal, the light control system being configured to control light emitted from an indicator light so as to indicate the specific location of the intrusion; and an indicator light capable of indicating the specific location of the intrusion, the indicator light being responsive to the light control system, the indicator light being located within an outer perimeter zone of the enclosed space, the indicator light being capable of emitting light that is visible from outside the outer perimeter zone of the enclosed space.
[0015] In another embodiment, the invention is a method of installing an alarm system for providing an indication of a specific location of an intrusion into an enclosed space, the enclosed space being surrounded by an outer perimeter zone, the indication enabling an observer situated outside the outer perimeter zone to learn the specific location of the intrusion, the alarm system comprising: mounting at least one interior sensor located within an enclosed space, the interior sensor being configured to generate a specific intrusion location signal in response to an intrusion into the enclosed space; installing a light control system responsive to the specific intrusion location signal, the light control system being configured to control light emitted from an indicator light so as to indicate the specific location of the intrusion; and mounting an indicator light capable of indicating the specific location of the intrusion, the indicator light being responsive to the light control system, the indicator light being located within an outer perimeter zone of the enclosed space, the indicator light being capable of emitting light that is visible from outside the outer perimeter zone of the enclosed space.
[0016] In some embodiments, the at least one interior sensor is capable of detecting intrusion into the enclosed space in proximity to a peripheral window of the enclosed space, a peripheral door of the enclosed space, a chimney of the enclosed space, and/or a general internal area of the enclosed space. In some embodiments, the indicator light is capable of directing light towards the specific location of the intrusion. In other embodiments, the indicator light is capable of directing light towards at least one of an external side of the enclosed space, an outer corner of the enclosed space, a door, a window, and/or a chimney. In other embodiments, the indicator light is located in immediate proximity to the specific location of the intrusion. In some of these embodiments, indicator light surrounds the specific location of the intrusion.
[0017] In some embodiments, the light is a focused light beam, a beacon light, a blinking light, and/or a rotating light. In other embodiments, the indicator light is a light display that is capable of producing a readable output of the specific location of the intrusion.
[0018] In some embodiments, the specific intrusion location signal is also received on a mobile device. In other embodiments, the system can be activated by a keypad installed near an entrance of the enclosed space, a keypad installed within the outer perimeter zone of the enclosed space, a manual key configured to fit a manual lock, a remote control device dedicated to activation of the system, a personal mobile communication device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will be more fully understood by reference to the detailed description, in conjunction with the following figures, wherein:
[0020] FIG. 1A is a block diagram showing the main elements of an embodiment of the alarm system;
[0021] FIG. 1B is an elements diagram showing the interaction between the main elements of an embodiment of the alarm system wherein the main elements are hard wired together;
[0022] FIG. 1C is an elements diagram showing the interaction between the main elements of an alternative embodiment of the alarm system wherein the main elements are connected together via wireless communication;
[0023] FIG. 2A is an aerial view of a house equipped with an installed version of an embodiment of the alarm system, showing the light output indicating a specific location of an intrusion;
[0024] FIG. 2B is an aerial view of a house equipped with an installed version of the embodiment shown in FIG. 2A , showing the light output indicating a more general location of an intrusion;
[0025] FIG. 3 is an aerial view of a house equipped with an embodiment of a combination of indicator lights of the alarm system;
[0026] FIG. 4 is an aerial view of a house equipped with an alternative embodiment of a combination of indicator lights of the alarm system;
[0027] FIG. 5 is an aerial view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system;
[0028] FIG. 6 is side view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system;
[0029] FIG. 7 is an illustration of a component of an embodiment of the alarm system, wherein a specific intrusion location message is produced on a mobile device;
[0030] FIG. 8 is an illustration of a room within a building employing an embodiment of the alarm system;
[0031] FIG. 9A depicts a keypad configured to control activating system for an embodiment of the alarm system;
[0032] FIG. 9B depicts a manual key and lock configured to control an activating system for an embodiment of the alarm system;
[0033] FIG. 9C depicts a remote dedicated device and receiver configured to control an activating system for an embodiment of the alarm system;
[0034] FIG. 9D depicts a personal mobile device and receiver configured to control an activating system for an embodiment of the alarm system; and
[0035] FIG. 10 is a flowchart depicting a sequence of events related to an embodiment of the alarm system in use.
DETAILED DESCRIPTION
[0036] FIG. 1A is a block diagram showing the main elements of an embodiment of the alarm system. In the embodiment represented by the diagram of the system elements 100 , several interior sensors are placed within an interior space of a building, which in this case is a house.
[0037] The enclosed space to be equipped with the alarm system can be any building or enclosed portion of a building (such as a section or room of the building) for which a user of the system wishes to receive notice of the intrusion by another into the enclosed space. Such enclosed space can include rooms, sections, levels, or entire internal areas of buildings such as houses, apartments, schools, dorm rooms, office buildings, factories, or any other buildings apparent to one of ordinary skill in the art of intrusion alert systems.
[0038] In the embodiment shown, the sensors are placed in such a manner so as to detect intrusion of the building. In alternative embodiments, sensors can be strategically placed so as to detect intrusion of a certain particular enclosed space of the building, such as a particular room or group of adjacent rooms, or an entire floor level of the building, for example. The exemplary sensors shown include a door sensor 102 , a window sensor 104 , a chimney sensor 106 , and an internal area sensor 108 .
[0039] Sensors can be placed in proximity to access points to the building or an enclosed portion of the building, so as to detect intrusion of the enclosed space through the access point. Such access points which the sensor may be placed near can include a door 102 , window 104 or chimney 106 , for example. Another sensor can be placed within a general internal area of an enclosed space 108 , so as to detect movement inside the enclosed space, or so as to employ any other means of detecting intrusion apparent to one of ordinary skill in the art of intrusion detection.
[0040] The sensors can be any kind of sensor configured to detect intrusion, such as a heat sensor or infrared sensor, for example. One skilled in the art will appreciate and readily acknowledge other possible sensors which can be used. If an intrusion occurs, a sensor will detect the intrusion and send a specific intrusion location signal to a control unit 110 . The control unit 110 will send the specific intrusion location signal to an indicator light located outside the enclosed space and in an outer perimeter zone of the enclosed space. The control unit 110 can serve as a light control system, configured to control the light so as to indicate the location of intrusion.
[0041] The indicator light will emit light so as to indicate that an intrusion has occurred, and to indicate the location of the intrusion. Other sensors positioned and configured to detect movement within the enclosed space for which intrusion is to be detected will be readily apparent to one ordinarily skilled in the art of intrusion detection. A light control system controls light emitted by the indicator light so as to indicate the location of the intrusion.
[0042] FIG. 1B is an elements diagram showing the interaction between the main elements of an embodiment of the alarm system, wherein the main elements are hard wired together with electrical wiring. A house 120 equipped with an embodiment of the alarm system is shown, containing a door sensor 122 , window sensor 124 , chimney sensor 126 , and internal area sensor 128 .
[0043] As depicted in this diagram, the sensors are hard wired to a common control unit 130 , which in turn is in hard wire communication with an indicator light 132 . In the embodiment shown, the control unit 130 is located outside the structure of the house 130 . Upon receiving a specific intrusion location signal from any of the sensors, the control unit 130 can propagate the signal to the indicator light 132 located in the outer perimeter zone of the enclosed space, which emits light that is visible beyond the outer perimeter zone of the enclosed space, thereby alerting others to an intrusion and the location of the intrusion. In this embodiment, the indicator light 132 is located outside the house but within a curtilage of the house 120 , and produces light that is visible beyond the curtilage.
[0044] In the embodiment shown, the indicator light 132 emits a light beam 133 that is directed towards the location of the intrusion, so as to indicate the location of the intrusion. In this example, the light 133 is directed towards the front door of the house, so as to indicate that the house was intruded via the front door.
[0045] FIG. 1C is an elements diagram showing the interaction between the main elements of an alternative embodiment of the alarm system wherein the main elements are connected together via wireless signaling. A house 120 equipped with an embodiment of the alarm system is shown, containing a door sensor 122 , window sensor 124 , chimney sensor 126 , and internal area sensor 128 .
[0046] As depicted in this diagram, the sensors are linked via wireless connection to a common control unit 140 , which in turn is in wireless communication with an indicator light 132 . In the embodiment shown, the control unit 140 is located inside the structure of the house 120 . Upon receiving a specific intrusion location signal from any of the sensors, the control unit 130 can propagate the signal to the indicator light 132 located in the outer perimeter zone of the enclosed space, which emits light that is visible beyond the outer perimeter zone of the enclosed space, thereby alerting others to an intrusion and the location of the intrusion. In this embodiment, the indicator light 132 is located outside the house but within a curtilage of the house 120 , and produces light that is visible beyond the curtilage.
[0047] In the embodiment shown, the indicator light 132 emits a light beam 133 that is directed towards the location of the intrusion, so as to indicate the location of the intrusion. In this example, the light 133 is directed towards the front door of the house, so as to indicate that the house was intruded via the front door.
[0048] FIG. 2A is an aerial view of a house equipped with an installed version of an embodiment of the alarm system, showing the light output indicating a specific location of an intrusion. In this embodiment, the house 200 is equipped with an indicator light 202 that emits a continuous light beam 203 .
[0049] In the embodiment shown in this figure, the light beam 203 is a window light 113 directed at a window through which the house has been intruded upon. Therefore, in this embodiment the indicator light 202 indicates the location of intrusion by directing the light beam 203 towards the specific intrusion location.
[0050] FIG. 2B is an aerial view of a house equipped with an installed version of the embodiment shown in FIG. 2A , showing the light output indicating a more general location of an intrusion. In this embodiment, the house 200 is equipped with an indicator light 202 that emits a continuous light beam 204 .
[0051] In the embodiment shown in this figure, the light beam 204 is a general area light 115 directed at a corner section of the house. The light beam 204 indicates that intrusion occurred within one of the entry points illuminated by the light beam 204 , including a front-facing window and a side-facing window. Such general information can be the result of an internal area sensor 108 , for example. The specific intrusion location signal will therefore provide more general information, than a specific intrusion location signal sent by a sensor dedicated to detecting intrusion of a specific access point, such as the embodiment shown and discussed in FIG. 2A .
[0052] FIG. 3 is an aerial view of a house equipped with an embodiment of a combination of indicator lights of the alarm system. A house 200 is equipped with an indicator light 202 that emits a continuous light beam 300 . In addition, this embodiment also includes a light display 302 capable of producing a readable output of the location of the intrusion, wherein the light control system is configured to control the readable output that is produced by the light display 302 . In the embodiment shown, the light display 302 is located on a wall near a doorway into the house 200 . The light display 302 is indicating that intrusion occurred through a kitchen window of the house 200 .
[0053] FIG. 4 is an aerial view of a house equipped with an alternative embodiment of a combination of indicator lights of the alarm system. A house 200 is equipped with an indicator light 400 that emits a beacon light 400 , such as light emitted omni-directionally from a bulb, as opposed to a focused beam. The beacon light 400 can be light of continuous output, or alternatively, it can be light of non-continuous output, such as a blinking light. The beacon light 400 is installed at the top of the house 200 .
[0054] In addition, this embodiment also includes a light display 402 capable of producing a readable output of the location of the intrusion, wherein the light control system is configured to control the readable output that is produced by the light display 402 . In the embodiment shown, the light display 402 is located on a wall around the corner from a doorway into the house 200 . The light display 402 is indicating that intrusion occurred through a kitchen window of the house 200 .
[0055] FIG. 5 is an aerial view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system. In this embodiment, the house 200 is equipped with a rotating light beam 500 , which is installed at the top of the house 200 . The light beam 500 is projected substantially horizontally from a rotating light source. In the embodiment shown, the rotating light beam 500 is a focused light beam which rotates about the vertical axis of its light source. This rotating light 600 can potentially alert others in all directions beyond the curtilage of the house 400 , potentially including those located within neighboring dwellings.
[0056] In addition, this embodiment also includes a light display 500 capable of producing a readable output of the location of the intrusion, wherein the light control system is configured to control the readable output that is produced by the light display 500 . In the embodiment shown, the light display 500 is located on a walkway towards a doorway of the house 200 . The light display 500 is indicating that intrusion through a kitchen window of the house 200 .
[0057] FIG. 6 is side view of a house equipped with another alternative embodiment of a combination of indicator lights of the alarm system. In the embodiment shown, a house 600 includes a light display 602 comprised of a plurality of lights surrounding the perimeter of a possible location of intrusion. In the embodiment shown, a series of lights surround the perimeter of a window. The lights are illuminated, thereby alerting others that the house 200 has been intruded upon, via the window that is illuminated by the light display 602 .
[0058] FIG. 7 is an illustration of a component of an embodiment of the alarm system, wherein a specific intrusion location message is produced on a mobile device. In the embodiment shown, a mobile device 700 receives a specific intrusion location message 702 , in addition to an indicator light signal being projected from the outer perimeter zone of the enclosed space with which the indicator light is associated. Such a mobile device specific intrusion location message 702 can supplement the indicator light, providing an enhancement to the alarm system. For example, if an intrusion is detected, the alarm system can alert those for whom the intruded enclosed space is in sight. In addition, a user of the alarm system can receive an alert 702 on their mobile device 700 , which can be an important and useful supplemental alert if and when they are not near or approaching the enclosed space. In the embodiment shown, the specific intrusion location message 702 indicates that intrusion occurred through a kitchen window of the house.
[0059] FIG. 8 is an illustration of a room within a building employing an embodiment of the alarm system. In this embodiment, the alarm system is configured to alert others of the location of an intrusion into an enclosed space within a building, in this instance the enclosed space being a room of a house. In this embodiment, a room 800 adjacent to the intruded room is equipped with an indicator light 802 . The indicator light in this example is a light display 802 which indicates readable output concerning the location of the intrusion.
[0060] The light display 802 shown is capable of producing a readable output of the location of the intrusion, wherein a light control system is configured to control the readable output that is produced by the light display. In the embodiment shown, the light display 802 is located above a doorway 804 which leads from the adjacent room 800 into the intruded room. The light display 802 is indicating that intrusion occurred through the door.
[0061] The indicator light 802 is located within the outer perimeter zone of the room equipped with the alarm system, and the light display 802 is visible and readable beyond the outer perimeter zone of the room equipped with the alarm system. For example, someone in the adjacent room 800 could easily see the light display and read the output. In some embodiments, several such indicator lights 802 may be placed at various locations within the outer perimeter zone of the enclosed space equipped with the alarm system, so as to alert others in various neighboring rooms, for example.
[0062] If an unexpected intrusion occurs in one room, the indicator light 802 can alert others in adjacent rooms 800 of the intrusion, for example. In other embodiments, the enclosed space under surveillance may be a group of rooms, or some other portion of a building, for example. The indicator light 802 is located in the outer perimeter zone immediately outside the enclosed space under surveillance. In this case, the outer perimeter zone includes the doorway 804 and wall of an adjacent room 800 . The indicator light 802 is therefore mounted on the adjacent wall of the doorway 804 connecting the intruded room with the adjacent room 800 .
[0063] The alarm system can be activated through a variety of techniques, some of which are discussed explicitly in this specification, while still others will be readily apparent to one of ordinary skill in the art. FIG. 9A depicts a keypad 900 configured to control an activating system in an embodiment of the alarm system. Such a keypad can be installed on an outer wall of a house, near an entrance into the house for example, or somewhere near the house and within the curtilage of the house, for example. The keypad is connected to and capable of communicating with an activator 902 which can activate the system.
[0064] FIG. 9B depicts a manual key and lock configured to control an activating system for an embodiment of the alarm system. In this embodiment, a manual key 904 can fit into a manual keyhole 906 , and whereupon the key 904 is inserted into the keyhole 906 and turned, the alarm system can be activated and/or deactivated via communication with an activator 902 .
[0065] The alarm system can also be activated via remote devices. FIG. 9C depicts a dedicated remote device 908 and a receiver 910 , which in combination are configured to control an activating system in an embodiment of the alarm system. A user of the system can activate the system using a remote control 908 which communicates with a receiver 910 , which in turn is linked to an activator 902 . FIG. 9D depicts a personal mobile device 912 and reception tower 913 in communication with a receiver 914 , which in turn is linked to an activator 902 and configured to control an activating system for an embodiment of the alarm system. Still other activation systems will be readily apparent to one of average skill in the art.
[0066] FIG. 10 is a flowchart depicting a sequence of events related to an embodiment of the alarm system in use, in relation to a structure. First, a potential intruder attempts to breach and/or intrude a structure or other enclosed space equipped with the system 1000 , with intent to intrude the structure or enclosed space. In this embodiment, the entire structure is equipped with the system, while in alternative embodiments only a sub-enclosure, such as a room within the structure, might be so equipped.
[0067] If the intruder succeeds in intruding the structure 10002 , an interior sensor will detect the intrusion 1004 and generate an intrusion signal 1006 , which in the present invention is a specific intrusion location signal indicating the location of the intrusion. If the system includes for the specific intrusion location signal to be sent to a user's mobile device 1008 , then the mobile device can be alerted 1010 . The specific intrusion location signal is sent to an indicator light 1012 , which then activates and outputs an alarm light 1014 upon receiving the information regarding the intrusion time signal. The indicator light indicates the location of intrusion. This completes the main operation of the system 1016 .
[0068] Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is not intended to limit the invention except as indicated in the following claims. | An alarm system for indicating the specific location of an intrusion into an enclosed space, as well as a method for installing the alarm system, are disclosed. The intrusion causes illumination of an indicator light outside the enclosed space and within the outer perimeter zone of the enclosed space, thereby indicating the specific location of the intrusion. At least one interior sensor located within the enclosed space generates a specific intrusion location signal in response to movement therein. A control system responsive to the specific intrusion location signal causes the indicator light to emit light that is visible from outside the outer perimeter zone of the enclosed space. The emitted light can indicate the specific location of an intrusion by directing light towards the specific intrusion location, and/or by surrounding the specific intrusion location, and/or by activating a light display that produces readable output of the specific intrusion location. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to education systems and more particularly to a rule based tutorial system that utilizes a table of components to control business simulations of actual environments to teach new skills.
BACKGROUND OF THE INVENTION
[0002] When building a knowledge based system or expert system, at least two disciplines are necessary to properly construct the rules that drive the knowledge base, the discipline of the knowledge engineer and the knowledge of the expert. The domain expert has knowledge of the domain or field of use of the expert system. For example, the domain expert of an expert for instructing students in an automotive manufacturing facility might be a process control engineer while the domain expert for a medical instruction system might be a doctor or a nurse. The knowledge engineer is a person that understands the expert system and utilizes the expert's knowledge to create an application for the system. In many instances, the knowledge engineer and domain expert are separate people who have to collaborate to construct the expert system.
[0003] Typically, this collaboration takes the form of the knowledge engineer asking questions of the domain expert and incorporating the answers to these questions into the design of the system. This approach is labor intensive, slow and error prone. The coordination of the two separate disciplines may lead to problems. Although the knowledge engineer can transcribe input from the expert utilizing videotape, audio tape, text and other sources, efforts from people of both disciplines have to be expended. Further, if the knowledge engineer does not ask the right questions or asks the questions in an incorrect way, the information utilized to design the knowledge base could be incorrect. Feedback to the knowledge engineer from the expert system is often not available in prior art system until the construction is completed. With conventional system, there is a time consuming feedback loop that ties together various processes from knowledge acquisition to validation.
[0004] Educational systems utilizing an expert system component often suffer from a lack of motivational aspects that result in a user becoming bored or ceasing to complete a training program. Current training programs utilize static, hard-coded feedback with some linear video and graphics used to add visual appeal and illustrate concepts. These systems typically support one “correct” answer and navigation through the system is only supported through a single defined path which results in a two-dimensional generic interaction, with no business model support and a single feedback to the learner of correct or incorrect based on the selected response. Current tutorial systems do not architect real business simulations into the rules to provide a creative learning environment to a user.
SUMMARY OF THE INVENTION
[0005] According to a broad aspect of a preferred embodiment of the invention, a goal based learning system utilizes a rule based expert training system to provide a cognitive educational experience. The system provides the user with a simulated environment that presents a business opportunity to understand and solve optimally. Mistakes are noted and remedial educational material presented dynamically to build the necessary skills that a user requires for success in the business endeavor. The system utilizes an artificial intelligence engine driving individualized and dynamic feedback with synchronized video and graphics used to simulate real-world environment and interactions. Multiple “correct” answers are integrated into the learning system to allow individualized learning experiences in which navigation through the system is at a pace controlled by the learner. A robust business model provides support for realistic activities and allows a user to experience real world consequences for their actions and decisions and entails realtime decision-making and synthesis of the educational material. The system is architected around a table of components to manage and control the system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The foregoing and other objects, aspects and advantages are better understood from the following detailed description of a preferred embodiment of the invention with reference to the drawings, in which:
[0007] FIG. 1 is a block diagram of a representative hardware environment in accordance with a preferred embodiment;
[0008] FIG. 2 is a block diagram of a system architecture in accordance with a preferred embodiment;
[0009] FIG. 3 depicts the timeline and relative resource requirements for each phase of development for a typical application development in accordance with a preferred embodiment;
[0010] FIG. 4 illustrates a small segment of a domain model for claims handlers in the auto insurance industry in accordance with a preferred embodiment;
[0011] FIG. 5 illustrates an insurance underwriting profile in accordance with a preferred embodiment;
[0012] FIG. 6 illustrates a transformation component in accordance with a preferred embodiment;
[0013] FIG. 7 illustrates the use of a toolbar to navigate and access application level features in accordance with a preferred embodiment;
[0014] FIG. 8 is a GBS display in accordance with a preferred embodiment;
[0015] FIG. 9 is a feedback display in accordance with a preferred embodiment;
[0016] FIG. 10 illustrates a journal entry simulation in accordance with a preferred embodiment;
[0017] FIG. 11 illustrates a simulated Bell Phone Bill journal entry in accordance with a preferred embodiment;
[0018] FIG. 12 illustrates a feedback display in accordance with a preferred embodiment;
[0019] FIG. 13 illustrates the steps of the first scenario in accordance with a preferred embodiment;
[0020] FIGS. 14 and 15 illustrate the steps associated with a build scenario in accordance with a preferred embodiment;
[0021] FIG. 16 illustrates a test scenario in accordance with a preferred embodiment. The test students work through the journalization activity;
[0022] FIG. 17 illustrates how the tool suite supports student administration in accordance with a preferred embodiment;
[0023] FIG. 18 illustrates a suite to support a student interaction in accordance with a preferred embodiment;
[0024] FIG. 19 illustrates the remediation process in accordance with a preferred embodiment;
[0025] FIG. 20 illustrates the objects for the journalization task in accordance with a preferred embodiment;
[0026] FIG. 21 illustrates the mapping of a source item to a target item in accordance with a preferred embodiment;
[0027] FIG. 22 illustrates an analysis of rules in accordance with a preferred embodiment;
[0028] FIG. 23 illustrates a feedback selection in accordance with a preferred embodiment;
[0029] FIG. 24 is a flowchart of the feedback logic in accordance with a preferred embodiment;
[0030] FIG. 25 is a block diagram setting forth the architecture of a simulation model in accordance with a preferred embodiment;
[0031] FIG. 26 illustrates the steps for configuring a simulation in accordance with a preferred embodiment;
[0032] FIG. 27 is a block diagram presenting the detailed architecture of a system dynamics model in accordance with a preferred embodiment;
[0033] FIG. 28 is an overview diagram of the logic utilized for initial configuration in accordance with a preferred embodiment;
[0034] FIG. 29 is a display of video information in accordance with a preferred embodiment; and
[0035] FIG. 30 illustrates an ICA utility in accordance with a preferred embodiment.
DETAILED DESCRIPTION
[0036] A preferred embodiment of a system in accordance with the present invention is preferably practiced in the context of a personal computer such as an IBM compatible personal computer, Apple Macintosh computer or UNIX based workstation. A representative hardware environment is depicted in FIG. 1 , which illustrates a typical hardware configuration of a workstation in accordance with a preferred embodiment having a central processing unit 110 , such as a microprocessor, and a number of other units interconnected via a system bus 112 . The workstation shown in FIG. 1 includes a Random Access Memory (RAM) 114 , Read Only Memory (ROM) 116 , an 1/0 adapter 118 for connecting peripheral devices such as disk storage units 120 to the bus 112 , a user interface adapter 122 for connecting a keyboard 124 , a mouse 126 , a speaker 128 , a microphone 132 , and/or other user interface devices such as a touch screen (not shown) to the bus 112 , communication adapter 134 for connecting the workstation to a communication network (e.g., a data processing network) and a display adapter 136 for connecting the bus 112 to a display device 138 . The workstation typically has resident thereon an operating system such as the Microsoft Windows NT or Windows/95 Operating System (OS), the IBM OS/2 operating system, the MAC OS, or UNIX operating system. Those skilled in the art will appreciate that the present invention may also be implemented on platforms and operating systems other than those mentioned.
[0037] A preferred embodiment is written using JAVA, C, and the C++ language and utilizes object oriented programming methodology. Object oriented programming (OOP) has become increasingly used to develop complex applications. As OOP moves toward the mainstream of software design and development, various software solutions require adaptation to make use of the benefits of OOP. A need exists for these principles of OOP to be applied to a messaging interface of an electronic messaging system such that a set of OOP classes and objects for the messaging interface can be provided. A simulation engine in accordance with a preferred embodiment is based on a Microsoft Visual Basic component developed to help design and test feedback in relation to a Microsoft Excel spreadsheet. These spreadsheet models are what simulate actual business functions and become a task that will be performed by a student The Simulation Engine accepts simulation inputs and calculates various outputs and notifies the system of the status of the simulation at a given time in order to obtain appropriate feedback.
Relationship of Components
[0038] The simulation model executes the business function that the student is learning and is therefore the center point of the application. An activity ‘layer’ allows the user to visually guide the simulation by passing inputs into the simulation engine and receiving an output from the simulation model. For example, if the student was working on an income statement activity, the net sales and cost of goods sold calculations are passed as inputs to the simulation model and the net income value is calculated and retrieved as an output. As calculations are passed to and retrieved from the simulation model, they are also passed to the Intelligent Coaching Agent (ICA). The ICA analyzes the Inputs and Outputs to the simulation model and generates feedback based on a set of rules. This feedback is received and displayed through the Visual Basic Architecture.
[0039] FIG. 2 is a block diagram of a system architecture in accordance with a preferred embodiment. The Presentation ‘layer’ 210 is separate from the activity ‘layer’ 220 and communication is facilitated through a set of messages 230 that control the display specific content topics. A preferred embodiment enables knowledge workers 200 & 201 to acquire complex skills rapidly, reliably and consistently across an organization to deliver rapid acquisition of complex skills. This result is achieved by placing individuals in a simulated business environment that “looks and feels” like real work, and challenging them to make decisions which support a business' strategic objectives utilizing highly effective learning theory (e.g., goal based learning, learn by doing, failure based learning, etc.), and the latest in multimedia user interfaces, coupled with three powerful, integrated software components. The first of these components is a software Solution Construction Aid (SCA) 230 consisting of a mathematical modeling tool 234 which simulates business outcomes of an individual's collective actions over a period of time. The second component is a knowledge system 250 consisting of an HTML content layer which organizes and presents packaged knowledge much like an online text book with practice exercises, video war stories, and a glossary. The third component is a software tutor 270 comprising an artificial intelligence engine 240 which generates individualized coaching messages based on decisions made by learner.
[0040] Feedback is unique for each individual completing the course and supports client cultural messages 242 “designed into” the course. A business simulation methodology that includes support for content acquisition, story line design, interaction design, feedback and coaching delivery, and content delivery is architected into the system in accordance with a preferred embodiment. A large number of “pre-designed” learning interactions such as drag and drop association of information 238 , situation assessment/action planning, interviewing (one-on-one, one-to-many), presenting (to a group of experts/executives), metering of performance (handle now, handle later), “time jumping” for impact of decisions, competitive landscape shift (while “time jumping”, competitors merge, customers are acquired, etc.) and video interviewing with automated note taking are also included in accordance with a preferred embodiment.
[0041] Business simulation in accordance with a preferred embodiment delivers training curricula in an optimal manner. This is because such applications provide effective training that mirrors a student's actual work environment. The application of skills “on the job” facilitates increased retention and higher overall job performance. While the results of such training applications are impressive, business simulations are very complex to design and build correctly. These simulations are characterized by a very open-ended environment, where students can go through the application along any number of paths, depending on their learning style and prior experiences/knowledge.
[0042] A category of learning approaches called Learn by Doing, is commonly used as a solution to support the first phase (Learn) of the Workforce Performance Cycle. However, it can also be a solution to support the second phase (Perform) of the cycle to enable point of need learning during job performance. By adopting the approach presented, some of the benefits of a technology based approach for building business simulation solutions which create more repeatable, predictable projects resulting in more perceived and actual user value at a lower cost and in less time are highlighted.
[0043] Most corporate training programs today are misdirected because they have failed to focus properly on the purpose of their training. These programs have confused the memorization of facts with the ability to perform tasks; the knowing of “that” with the knowing of “how”. By adopting the methods of traditional schools, businesses are teaching a wide breadth of disconnected, decontextualized facts and figures, when they should be focused on improved performance. How do you teach performance, when lectures, books, and tests inherently are designed around facts and figures? Throw away the lectures, books, and tests. The best way to prepare for high performance is to perform; experience is the best teacher! Most business leaders agree that workers become more effective the more time they spend in their jobs. The best approach for training novice employees, therefore, would be letting them learn on the job, acquiring skills in their actual work environment. The idea of learning-by-doing is not revolutionary, yet it is resisted in business and academia. Why is this so, if higher competence is universally desired?
[0044] Learners are reluctant to adopt learning-by-doing because they are frightened of failure. People work hard to avoid making mistakes in front of others. Business leaders are hesitant to implement learning-by-doing because novice failure may have dramatic safety, legal and financial implications. Imagine a novice pilot learning-by-doing as he accelerates a large jet plane down a runway; likewise, consider a new financial analyst learning-by-doing as he structures a multi-million dollar financial loan. Few employers are willing to endure such failures to have a more competent workforce.
[0045] The key to such a support system is that it is seamlessly integrated into the business system that the knowledge worker uses to execute their job tasks. Workers don't need to go “off-line” or seek out cryptic information buried within paper manuals and binders for guidance or to find the answer to queries. All the support components are made available through the same applications the worker's use, at the point in which they need them, tailored to the individual to show “how”, not just “what”. Learning would be occurring all the time, with little distinction between performing and improving performance. Establishing that training should focus on performance (how), rather than facts (what), and extending the model of learning to include assistance while performing, rather than only before performance, still leaves us dangerously exposed in preparing to compete in the new, chaotic economy. As was mentioned in the opening of this paper, the pace of change in business today is whiplash fast. Not only are new methods of doing business evolving every 18-24 months, new competitors emerge, dominate, and fade in time periods businesses used to take to perform demographic studies. Now more than ever, those who do not reinvent themselves on a regular basis will be fossilized by the pace of change. A typical BusSim engagement takes between one and two years to complete and requires a variety of both functional and technical skills. FIG. 3 depicts the timeline and relative resource requirements for each phase of development for a typical application development in accordance with a preferred embodiment. The chart clearly depicts the relationship between the large number of technical resources required for both the build and test phases of development. This is because the traditional development process used to build BusSim solutions reflects more of a “one off” philosophy, where development is done from scratch in a monolithic fashion, with little or no reuse from one application to the next. This lack of reuse makes this approach prohibitively expensive, as well as lengthy, for future BusSim projects.
[0046] The solution to this problem is to put tools in the hands of instructional designers that allows them to create their BusSim designs and implement them without the need for programmers to write code. And to put application architectures that integrate with the tools in the hands of developers, providing then with the ability to quickly deliver solutions for a number of different platforms. The reuse, then, comes in using the tools and architectures from one engagement to another. Both functional and technical resources carry with them the knowledge of how to use the technology, which also has an associated benefit of establishing a best-practice development methodology for BusSim engagements.
Development Cycle Activities
[0047] In the Design Phase, instructional designers become oriented to the content area and begin to conceptualize an instructional approach. They familiarize themselves with the subject matter through reading materials and interviews with Subject Matter Experts (SMEs). They also identify learning objectives from key client contacts. Conceptual designs for student interactions and interface layouts also begin to emerge. After the conceptual designs have taken shape, Low-Fi user testing (a. k. a. Conference Room Piloting) is performed. Students interact with interface mock-ups while facilitators observe and record any issues. Finally, detailed designs are created that incorporate findings. These detailed designs are handed off to the development team for implementation. The design phase has traditionally been fraught with several problems. Unlike a traditional business system, BusSim solutions are not rooted in tangible business processes, so requirements are difficult to identify in a concrete way. This leaves instructional designers with a ‘blue sky’ design problem. With few business-driven constraints on the solution, shallow expertise in the content area, and limited technical skills, instructional designers have little help in beginning a design. Typically, only experienced designers have been able to conjure interface, analysis, and feedback designs that meet the learning objectives yet remain technically feasible to implement. To compound the problem, BusSim solutions are very open ended in nature. The designer must anticipate a huge combination of student behavior to design feedback that is helpful and realistic.
[0048] During the build phase, the application development team uses the detailed designs to code the application. Coding tasks include the interfaces and widgets that the student interacts with. The interfaces can be made up of buttons, grids, check boxes, or any other screen controls that allow the student to view and manipulate his deliverables. The developer must also code logic that analyzes the student's work and provides feedback interactions. These interactions may take the form of text and/or multimedia feedback from simulated team members, conversations with simulated team members, or direct manipulations of the student's work by simulated team members. In parallel with these coding efforts, graphics, videos, and audio are being created for use in the application. Managing the development of these assets have their own complications. Risks in the build phase include misinterpretation of the designs. If the developer does not accurately understand the designer's intentions, the application will not function as desired. Also, coding these applications requires very skilled developers because the logic that analyzes the student's work and composes feedback is very complex.
[0049] The Test Phase, as the name implies, is for testing the application. Testing is performed to verify the application in three ways: first that the application functions property (functional testing), second that the students understand the interface and can navigate effectively (usability testing), and third that the learning objectives are met (cognition testing). Functional testing of the application can be carried out by the development team or by a dedicated test team. If the application fails to function properly, it is debugged, fixed, recompiled and retested until its operation is satisfactory. Usability and cognition testing can only be carried out by test students who are unfamiliar with the application. If usability is unsatisfactory, parts of the interface and or feedback logic may need to be redesigned, recoded, and retested. If the learning objectives are not met, large parts of the application may need to be removed and completely redeveloped from a different perspective. The test phase is typically where most of the difficulties in the BusSim development cycle are encountered. The process of discovering and fixing functional, usability, and cognition problems is a difficult process and not an exact science.
[0050] For functional testing, testers operate the application, either by following a test script or by acting spontaneously and documenting their actions as they go. When a problem or unexpected result is encountered, it too is documented. The application developer responsible for that part of the application then receives the documentation and attempts to duplicate the problem by repeating the tester's actions. When the problem is duplicated, the developer investigates further to find the cause and implement a fix. The developer once again repeats the tester's actions to verify that the fix solved the problem. Finally, all other test scripts must be rerun to verify that the fix did not have unintended consequences elsewhere in the application. The Execution Phase refers to the steady state operation of the completed application in its production environment. For some clients, this involves phone support for students. Clients may also want the ability to track students' progress and control their progression through the course. Lastly, clients may want the ability to track issues so they may be considered for inclusion in course maintenance releases.
[0051] One of the key values of on-line courses is that they can be taken at a time, location, and pace that is convenient for the individual student. However, because students are not centrally located, support is not always readily available. For this reason it is often desirable to have phone support for students. Clients may also desire to track students' progress, or control their advancement through the course. Under this strategy, after a student completes a section of the course, he will transfer his progress data to a processing center either electronically or by physically mailing a disk. There it can be analyzed to verify that he completed all required work satisfactorily. One difficulty commonly associated with student tracking is isolating the student data for analysis. It can be unwieldy to transmit all the course data, so it is often imperative to isolate the minimum data required to perform the necessary analysis of the student's progress.
A Delivery Framework for Business Simulation
[0052] As discussed earlier, the traditional development process used to build BusSim solutions reflects more of a “one off” philosophy, where development is done from scratch in a monolithic fashion, with little or no reuse from one application to the next. A better approach would be to focus on reducing the total effort required for development through reuse, which, in turn would decrease cost and development time. The first step in considering reuse as an option is the identification of common aspects of the different BusSim applications that can be generalized to be useful in future applications. In examination of the elements that make up these applications, three common aspects emerge as integral parts of each: Interface, Analysis and Interpretation. Every BusSim application must have a mechanism for interaction with the student. The degree of complexity of each interface may vary, from the high interactivity of a high-fidelity real-time simulation task, to the less complex information delivery requirements of a business case background information task. Regardless of how sophisticated the User Interface (UI), it is a vital piece of making the underlying simulation and feedback logic useful to the end user.
[0053] Every BusSim application does analysis on the data that defines the current state of the simulation many times throughout the execution of the application. This analysis is done either to determine what is happening in the simulation, or to perform additional calculations on the data which are then fed back into the simulation. For example, the analysis may be the recognition of any actions the student has taken on artifacts within the simulated environment (notebooks, number values, interviews conducted, etc.), or it may be the calculation of an ROI based on numbers the student has supplied. Substantive, useful feedback is a critical piece of any BusSim application. It is the main mechanism to communicate if actions taken by the student are helping or hurting them meet their performance objectives. The interpretation piece of the set of proposed commonalties takes the results of any analysis performed and makes sense of it. It takes the non-biased view of the world that the Analysis portion delivers (i.e., “Demand is up 3%”) and places some evaluative context around it (i.e., “Demand is below the expected 7%; you're in trouble!”, or “Demand has exceeded projections of 1.5%; Great job!”).
[0054] There are several approaches to capturing commonalties for reuse. Two of the more common approaches are framework-based and component-based. To help illustrate the differences between the two approaches, we will draw an analogy between building an application and building a house. One can construct a house from scratch, using the raw materials, 2×4s, nails, paint, concrete, etc. One can also construct an application from scratch, using the raw materials of new designs and new code. The effort involved in both undertakings can be reduced through framework-based and/or component-based reuse. Within the paradigm of framework-based reuse, a generic framework or architecture is constructed that contains commonalties. In the house analogy, one could purchase a prefabricated house framework consisting of floors, outside walls, bearing walls and a roof. The house can be customized by adding partition walls, wall-paper, woodwork, carpeting etc. Similarly, prefabricated application frameworks are available that contain baseline application structure and functionality. Individual applications are completed by adding specific functionality and customizing the look-and-feel. An example of a commonly used application framework is Microsoft Foundation Classes. It is a framework for developing Windows applications using C++. MFC supplies the base functionality of a windowing application and the developer completes the application by adding functionality within the framework. Framework-based reuse is best suited for capturing template-like features, for example user interface management, procedural object behaviors, and any other features that may require specialization. Some benefits of using a framework include:
[0055] Extensive functionality can be incorporated into a framework. In the house analogy, if I know I am going to build a whole neighborhood of three bedroom ranches, I can build the plumbing, wiring, and partition walls right into the framework, reducing the incremental effort required for each house. If I know I am going to build a large number of very similar applications, they will have more commonalties that can be included in the framework rather than built individually.
[0056] Applications can override the framework-supplied functionality wherever appropriate. If a house framework came with pre-painted walls, the builder could just paint over them with preferred colors. Similarly, the object oriented principle of inheritance allows an application developer to override the behavior of the framework. In the paradigm of component-based reuse, key functionality is encapsulated in a component. The component can then be reused in multiple applications. In the house analogy, components correspond to appliances such as dishwashers, refrigerators, microwaves, etc. Similarly, many application components with pre-packaged functionality are available from a variety of vendors. An example of a popular component is a Data Grid. It is a component that can be integrated into an application to deliver the capability of viewing columnar data in a spreadsheet-like grid. Component-based reuse is best suited for capturing black-box-like features, for example text processing, data manipulation, or any other features that do not require specialization.
[0057] Several applications on the same computer can share a single component. This is not such a good fit with the analogy, but imagine if all the houses in a neighborhood could share the same dishwasher simultaneously. Each home would have to supply its own dishes, detergent, and water, but they could all wash dishes in parallel. In the application component world, this type of sharing is easily accomplished and results in reduced disk and memory requirements.
[0058] Components tend to be less platform and tool dependent. A microwave can be used in virtually any house, whether it's framework is steel or wood, and regardless of whether it was customized for building mansions or shacks. You can put a high-end microwave in a low-end house and vice-versa. You can even have multiple different microwaves in your house. Component technologies such as CORBA, COM, and Java Beans make this kind of flexibility commonplace in application development. Often, the best answer to achieving reuse is through a combination of framework-based and component-based techniques. A framework-based approach for building BusSim applications is appropriate for developing the user interface, handling user and system events, starting and stopping the application, and other application-specific and delivery platform-specific functions. A component-based approach is appropriate for black-box functionality. That is, functionality that can be used as-is with no specialization required. In creating architectures to support BusSim application development, it is imperative that any assets remain as flexible and extensible as possible or reusability may be diminished. Therefore, we chose to implement the unique aspects of BusSim applications using a component approach rather than a framework approach. This decision is further supported by the following observations.
Delivery Framework for Business Simulation
[0059] Components are combined with an Application Framework and an Application Architecture to achieve maximum reuse and minimum custom development effort. The Application Architecture is added to provide communication support between the application interface and the components, and between the components. This solution has the following features: The components (identified by the icons) encapsulate key BusSim functionality. The Application Architecture provides the glue that allows application-to-component and component-to-component communication. The Application Framework provides structure and base functionality that can be customized for different interaction styles. Only the application interface must be custom developed. The next section discusses each of these components in further detail.
The Business Simulation Toolset
[0060] We have clearly defined why a combined component/framework approach is the best solution for delivering high-quality BusSim solutions at a lower cost. Given that there are a number of third party frameworks already on the market that provide delivery capability for a wide variety of platforms, the TEL project is focused on defining and developing a set of components that provide unique services for the development and delivery of BusSim solutions. These components along with a set of design and test workbenches are the tools used by instructional designers to support activities in the four phases of BusSim development. We call this suite of tools the Business Simulation Toolset. Following is a description of each of the components and workbenches of the toolset. A Component can be thought of as a black box that encapsulates the behavior and data necessary to support a related set of services. It exposes these services to the outside world through published interfaces. The published interface of a component allows you to understand what it does through the services it offers, but not how it does it. The complexity of its implementation is hidden from the user. The following are the key components of the BusSim Toolset. Domain Component-provides services for modeling the state of a simulation. Profiling Component-provides services for rule-based evaluating the state of a simulation. Transformation Component-provides services for manipulating the state of a simulation. Remediation Component-provides services for the rule-based delivering of feedback to the student The Domain Model component is the central component of the suite that facilitates communication of context data across the application and the other components. It is a modeling tool that can use industry-standard database such as Informix, Oracle, or Sybase to store its data. A domain model is a representation of the objects in a simulation. The objects are such pseudo tangible things as a lever the student can pull, a form or notepad the student fills out, a character the student interacts with in a simulated meeting, etc. They can also be abstract objects such as the ROI for a particular investment, the number of times the student asked a particular question, etc. These objects are called entities. Some example entities include: Vehicles, operators and incidents in an insurance domain; Journal entries, cash flow statements and balance sheets in a financial accounting domain and Consumers and purchases in a marketing domain.
[0061] An entity can also contain other entities. For example, a personal bank account entity might contain an entity that represents a savings account. Every entity has a set of properties where each property in some way describes the entity. The set of properties owned by an entity, in essence, define the entity. Some example properties include: An incident entity on an insurance application owns properties such as “Occurrence Date”, “Incident Type Code”, etc. A journal entry owns properties such as “Credit Account”, “Debit Account”, and “Amount”; and a revolving credit account entity on a mortgage application owns properties such as “Outstanding Balance”, “Available Limit”, etc. FIG. 4 Illustrates a small segment of a domain model for claims handlers in the auto insurance industry in accordance with a preferred embodiment.
Profiling Component
[0062] In the simplest terms, the purpose of the Profiling Component is to analyze the current state of a domain and identify specific things that are true about that domain. This information is then passed to the Remediation Component which provides feedback to the student. The Profiling Component analyzes the domain by asking questions about the domain's state, akin to an investigator asking questions about a case. The questions that the Profiler asks are called profiles. For example, suppose there is a task about building a campfire and the student has just thrown a match on a pile of wood, but the fire didn't start. In order to give useful feedback to the student, a tutor would need to know things like: was the match lit?, was the wood wet?, was there kindling in the pile?, etc. These questions would be among the profiles that the Profiling Component would use to analyze the domain. The results of the analysis would then be passed off to the Remediation Component which would use this information to provide specific feedback to the student. Specifically, a profile is a set of criteria that is matched against the domain. The purpose of a profile is to check whether the criteria defined by the profile is met in the domain. Using a visual editing tool, instructional designers create profiles to identify those things that are important to know about the domain for a given task. During execution of a BusSim application at the point that feedback is requested either by the student or pro-actively by the application, the set of profiles associated with the current task are evaluated to determine which ones are true. Example profiles include: Good productions strategy but wrong Break-Even Formula; Good driving record and low claims history; and Correct Cash Flow Analysis but poor Return on Investment (ROI).
[0063] A profile is composed of two types of structures: characteristics and collective characteristics. A characteristic is a conditional (the if half of a rule) that identifies a subset of the domain that is important for determining what feedback to deliver to the student. Example characteristics include: Wrong debit account in transaction 1 ; Perfect cost classification; At Least 1 DUI in the last 3 years; More than $4000 in claims in the last 2 years; and More than two at-fault accidents in 5 years A characteristic's conditional uses one or more atomics as the operands to identify the subset of the domain that defines the characteristic. An atomic only makes reference to a single property of a single entity in the domain; thus the term atomic. Example atomics include: The number of DUI's>=1; ROI>10%; and Income between $75,000 and $110,000. A collective characteristic is a conditional that uses multiple characteristics and/or other collective characteristics as its operands. Collective characteristics allow instructional designers to build richer expressions (i.e., ask more complex questions). Example collective characteristics include: Bad Household driving record; Good Credit Rating; Marginal Credit Rating; Problems with Cash for Expense transactions; and Problems with Sources and uses of cash. Once created, designers are able to reuse these elements within multiple expressions, which significantly eases the burden of creating additional profiles. When building a profile from its elements, atomics can be used by multiple characteristics, characteristics can be used by multiple collective characteristics and profiles, and collective characteristics can be used by multiple collective characteristics and profiles. FIG. 5 illustrates an insurance underwriting profile in accordance with a preferred embodiment.
Example Profile for Insurance Underwriting
[0064] Transformation Component—Whereas the Profiling Component asks questions about the domain, the Transformation Component performs calculations on the domain and feeds the results back into the domain for further analysis by the Profiling Component. This facilitates the modeling of complex business systems that would otherwise be very difficult to implement as part of the application. Within the Analysis phase of the Interface/Analysis/Interpretation execution flow, the Transformation Component actually acts on the domain before the Profiling Component does its analysis. The Transformation Component acts as a shell that wraps one or more data modeling components for the purpose of integrating these components into a BusSim application. The Transformation Component facilitates the transfer of specific data from the domain to the data modeling component (inputs) for calculations to be performed on the data, as well as the transfer of the results of the calculations from the data modeling component back to the domain (outputs). FIG. 6 illustrates a transformation component in accordance with a preferred embodiment. The data modeling components could be third party modeling environments such as spreadsheet-based modeling (e.g., Excel, Formula1) or discrete time-based simulation modeling (e.g., PowerSim, VenSim). The components could also be custom built in C++, VB, Access, or any tool that is ODBC compliant to provide unique modeling environments. Using the Transformation Component to wrap a third party spreadsheet component provides an easy way of integrating into an application spreadsheet-based data analysis, created by such tools as Excel. The Transformation Component provides a shell for the spreadsheet so that it can look into the domain, pull out values needed as inputs, performs its calculations, and post outputs back to the domain.
[0065] For example, if the financial statements of a company are stored in the domain, the domain would hold the baseline data like how much cash the company has, what its assets and liabilities are, etc. The Transformation Component would be able to look at the data and calculate additional values like cash flow ratios, ROI or NPV of investments, or any other calculations to quantitatively analyze the financial health of the company. Depending on their complexity, these calculations could be performed by pre-existing spreadsheets that a client has already spent considerable time developing.
[0066] Remediation Component—The Remediation Component is an expert system that facilitates integration of intelligent feedback into BusSim applications. It has the following features: Ability to compose high quality text feedback; Ability to compose multimedia feedback that includes video and/or audio; Ability to include reference material in feedback such as Authorware pages or Web Pages and Ability to actively manipulate the users deliverables to highlight or even fix users' errors. A proven remediation theory embedded in its feedback composition algorithm allows integration of digital assets into the Remediation of a training or IPS application. The Remediation model consists of three primary objects: Concepts; Coach Topics and Coach Items. Concepts are objects that represent real-world concepts that the user will be faced with in the interface. Concepts can be broken into sub-concepts, creating a hierarchical tree of concepts. This tree can be arbitrarily deep and wide to support rich concept modeling. Concepts can also own an arbitrary number of Coach Topics. Coach Topics are objects that represent a discussion topic that may be appropriate for a concept. Coach Topics can own an arbitrary number of Coach Items. Coach Items are items of feedback that may include text, audio, video, URL's, or updates to the Domain Model. Coach Items are owned by Coach Topics and are assembled by the Remediation Component algorithm.
[0067] Workbenches—The BusSim Toolset also includes a set of workbenches that are used by instructional designers to design and build BusSim applications. A workbench is a tool that facilitates visual editing or testing of the data that the BusSim Components use for determining an application's run-time behavior. The BusSim Toolset includes the following workbenches: Knowledge Workbench—The Knowledge Workbench is a tool for the creation of domain, analysis and feedback data that is used by the BusSim Components. It has the following features: Allows the designer to ‘paint’ knowledge in a drag-and-drop interface; Knowledge is represented visually for easy communication among designers; The interface is intelligent, allowing designers to only paint valid interactions; Designer's Task creations are stored in a central repository; The workbench supports check-in/check-out for exclusive editing of a task; Supports LAN-based or untethered editing; Automatically generates documentation of the designs; and it Generates the data files that drive the behavior of the components. Simulated Student Test Workbench—The Simulated Student Test Workbench is a tool for the creation of data that simulates student's actions for testing BusSim Component behaviors. It has the following features: The Test Bench generates a simulated application interface based on the Domain Model; The designer manipulates the objects in the Domain Model to simulate student activity; The designer can invoke the components to experience the interactions the student will experience in production; and The designer can fully test the interaction behavior prior to development of the application interface. Regression Test Workbench—The Regression Test Workbench is a tool for replaying and testing of student sessions to aid debugging. It has the following features: Each student submission can be individually replayed through the components; An arbitrary number of student submissions from the same session can be replayed in succession; Entire student sessions can be replayed in batch instantly; The interaction results of the student are juxtaposed with the results of the regression test for comparison.
Development Cycle Activities
[0068] The design phase of a BusSim application is streamlined by the use of the Knowledge Workbench. The Knowledge Workbench is a visual editor for configuring the objects of the component engines to control their runtime behavior. The components are based on proven algorithms that capture and implement best practices and provide a conceptual framework and methodology for instructional design. In conceptual design, the workbench allows the designer to paint a model of the hierarchy of Concepts that the student will need to master in the activity. This helps the designer organize the content in a logical way. The visual representation of the Concepts helps to communicate ideas to other designers for review. The consistent look and feel of the workbench also contributes to a streamlined Quality Assurance process. In addition, standard documentation can be automatically generated for the entire design. As the design phase progresses, the designer adds more detail to the design of the Concept hierarchy by painting in Coach Topics that the student may need feedback on. The designer can associate multiple feedback topics with each Concept. The designer also characterizes each topic as being Praise, Polish, Focus, Redirect or one of several other types of feedback that are consistent with a proven remediation methodology. The designer can then fill each topic with text, video war stories, Web page links, Authorware links, or any other media object that can be delivered to the student as part of the feedback topic.
[0069] The toolset greatly reduces effort during functionality testing. The key driver of the effort reduction is that the components can automatically track the actions of the tester without the need to add code support in the application. Whenever the tester takes an action in the interface, it is reported to the domain model. From there it can be tracked in a database. Testers no longer need to write down their actions for use in debugging; they are automatically written to disk. There is also a feature for attaching comments to a tester's actions. When unexpected behavior is encountered, the tester can hit a control key sequence that pops up a dialog to record a description of the errant behavior. During the Execution Phase, the components are deployed to the student's platform. They provide simulated team member and feedback functionality with sub-second response time and error-free operation. If the client desires it, student tracking mechanisms can be deployed at runtime for evaluation and administration of students. This also enables the isolation of any defects that may have made it to production.
Scenarios for Using the Business Simulation Toolset
[0070] A good way to gain a better appreciation for how the BusSim Toolset can vastly improve the BusSim development effort is to walk through scenarios of how the tools would be used throughout the development lifecycle of a particular task in a BusSim application. For this purpose, we'll assume that the goal of the student in a specific task is to journalize invoice transactions, and that this task is within the broader context of learning the fundamentals of financial accounting. A cursory description of the task from the student's perspective will help set the context for the scenarios. Following the description are five scenarios which describe various activities in the development of this task. The figure below shows a screen shot of the task interface. FIG. 7 illustrates the use of a toolbar to navigate and access application level features in accordance with a preferred embodiment. A student uses a toolbar to navigate and also to access some of the application-level features of the application. The toolbar is the inverted L-shaped object across the top and left of the interface. The top section of the toolbar allows the user to navigate to tasks within the current activity. The left section of the toolbar allows the student to access other features of the application, including feedback. The student can have his deliverables analyzed and receive feedback by clicking on the Team button.
[0071] In this task, the student must journalize twenty-two invoices and other source documents to record the flow of budget dollars between internal accounts. (Note: “Journalizing”, or “Journalization”, is the process of recording journal entries in a general ledger from invoices or other source documents during an accounting period. The process entails creating debit and balancing credit entries for each document. At the completion of this process, the general ledger records are used to create a trial balance and subsequent financial reports.) In accordance with a preferred embodiment, an Intelligent Coaching Agent Tool (ICAT) was developed to standardize and simplify the creation and delivery of feedback in a highly complex and open-ended environment. Feedback from a coach or tutor is instrumental in guiding the learner through an application. Moreover, by diagnosing trouble areas and recommending specific actions based on predicted student understanding of the domain student comprehension of key concepts is increased. By writing rules and feedback that correspond to a proven feedback strategy, consistent feedback is delivered throughout the application, regardless of the interaction type or of the specific designer/developer creating the feedback. The ICAT is packaged with a user-friendly workbench, so that it may be reused to increase productivity on projects requiring a similar rule-based data engine and repository.
DEFINITION OF ICAT IN ACCORDANCE WITH A PREFERRED EMBODIMENT
[0072] The Intelligent Coaching Agent Tool (ICAT) is a suite of tools—a database and a Dynamic Link Library (DLL) run-time engine-used by designers to create and execute just-in-time feedback of Goal Based training. Designers write feedback and rules in the development tools. Once the feedback is set, the run-time engine monitors user actions, fires rules and composes feedback which describes the business deliverable. The remediation model used within ICAT dynamically composes the most appropriate feedback to deliver to a student based on student's previous responses. The ICAT model is based on a theory of feedback which has been proven effective by pilot results and informal interviews. The model is embodied in the object model and algorithms of the ICAT. Because the model is built into the tools, all feedback created with the tool will conform to the model. ICAT plays two roles in student training. First, the ICAT is a teaching system, helping students to fully comprehend and apply information. Second, ICAT is a gatekeeper, ensuring that each student has mastered the material before moving on to additional information. ICAT is a self contained module, separate from the application. Separating the ICAT from the application allows other projects to use the ICAT and allows designers to test feedback before the application is complete. The ICAT Module is built on six processes which allow a student to interact effectively with the interface to compose and deliver the appropriate feedback for a student's mistakes. ICAT development methodology is a seven step methodology for creating feedback. The methodology contains specific steps, general guidelines and lessons learned from the field. Using the methodology increases the effectiveness of the feedback to meet the educational requirements of the course. The processes each contain a knowledge model and some contain algorithms. Each process has specific knowledge architected into its design to enhance remediation and teaching. There is a suite of testing tools for the ICAT. These tools allow designers and developers test all of their feedback and rules. In addition, the utilities let designers capture real time activities of students as they go through the course. The tools and run-time engine in accordance with a preferred embodiment include expert knowledge of remediation. These objects include logic that analyzes a student's work to identify problem areas and deliver focused feedback. The designers need only instantiate the objects to put the tools to work. Embodying expert knowledge in the tools and engine ensures that each section of a course has the same effective feedback structure in place. A file structure in accordance with a preferred embodiment provides a standard system environment for all applications in accordance with a preferred embodiment. A development directory holds a plurality of sub-directories. The content in the documentation directory is part of a separate installation from the architecture. This is due to the size of the documentation directory. It does not require any support files, thus it may be placed on a LAN or on individual computers. When the architecture is installed in accordance with a preferred embodiment, the development directory has an Arch, Tools, Utilities, Documentation, QED, and XDefault development directory. Each folder has its own directory structure that is inter-linked with the other directories. This structure must be maintained to assure consistency and compatibility between projects to clarify project differences, and architecture updates.
[0073] The_Arch directory stores many of the most common parts of the system architecture. These files generally do not change and can be reused in any area of the project. If there is common visual basic code for applications that will continuously be used in other applications, the files will be housed in a folder in this directory. The sub-directories in the_Arch directory are broken into certain objects of the main project. Object in this case refers to parts of a project that are commonly referred to within the project. For example, modules and classes are defined here, and the directory is analogous to a library of functions, APIs, etc. that do not change. For example the IcaObj directory stores code for the Intelligent Coaching Agent (ICA). The InBoxObj directory stores code for the InBox part of the project and so on. The file structure uses some primary object references as file directories. For example, the IcaObj directory is a component that contains primary objects for the ICA such as functional forms, modules and classes. The BrowserObj directory contains modules, classes and forms related to the browser functionality in the architecture. The HTMLGlossary directory contains code that is used for the HTML reference and glossary component of the architecture. The IcaObj directory contains ICA functional code to be used in an application. This code is instantiated and enhanced in accordance with a preferred embodiment. The InBoxObj directory contains code pertaining to the inbox functionality used within the architecture. Specifically, there are two major components in this architecture directory. There is a new. ocx control that was created to provide functionality for an inbox in the application. There is also code that provides support for a legacy inbox application. The PracticeObj directory contains code for the topics component of the architecture. The topics component can be implemented with the HTMLGlossary component as well. The QmediaObj directory contains the components that are media related. An example is the QVIDctrl. cls. The QVIDctrl is the code that creates the links between QVID files in an application and the system in accordance with a preferred embodiment. The SimObj directory contains the Simulation Engine, a component of the application that notifies the tutor of inputs and outputs using a spreadsheet to facilitate communication. The StaticObj directory holds any component that the application will use statically from the rest of the application. For example, the login form is kept in this folder and is used as a static object in accordance with a preferred embodiment. The SysDynObj directory contains the code that allows the Systems Dynamics Engine (Powersim) to pass values to the Simulation Engine and return the values to the tutor. The VBObj directory contains common Visual Basic objects used in applications. For example the NowWhat, Visual Basic Reference forms, and specific message box components are stored in this folder. The Tools directory contains two main directories. They represent the two most used tools in accordance with a preferred embodiment. The two directories provide the code for the tools themselves. The reason for providing the code for these tools is to allow a developer to enhance certain parts of the tools to extend their ability. This is important for the current project development and also for the growth of the tools. The Icautils directory contains a data, database, default, graphics, icadoc, and testdata directory. The purpose of all of these directories is to provide a secondary working directory for a developer to keep their testing environment of enhanced Icautils applications separate from the project application. It is built as a testbed for the tool only. No application specific work should be done here. The purpose of each of these directories will be explained in more depth in the project directory section. The TestData folder is unique to the Tools/ICAUtils directory. It contains test data for the regression bench among others components in ICAUtils.
[0074] The Utilities directory holds the available utilities that a Business Simulation project requires for optimal results. This is a repository for code and executable utilities that developers and designers may utilize and enhance in accordance with a preferred embodiment. Most of the utilities are small applications or tools that can be used in the production of simulations which comprise an executable and code to go with it for any enhancements or changes to the utility. If new utilities are created on a project or existing utilities are enhanced, it is important to notify the managers or developers in charge of keeping track of the Business Simulation assets. Any enhancements, changes or additions to the Business Simulation technology assets are important for future and existing projects.
[0075] In the ICAT model of feedback, there are four levels of severity of error and four corresponding levels of feedback. The tutor goes through the student's work, identifies the severity of the error and then provides the corresponding level of feedback.
[0000]
Educational Categories of Feedback
ERROR
FEEDBACK
Feedback
Error Type
Description
Type
Description
None
No errors exist. The student's
Praise
Confirmation that the student
work is perfect.
completed the task correctly.
Example: Great. You have
journalized all accounts
correctly. I am happy to see
you recognized we are paying
for most of our bills “on
account.”
Syntactic
There may be spelling
Polish
Tells the student specific
mistakes or other syntactic
actions he did incorrectly, and
errors. As a designer, you
possibly correct them for him.
should be confident that the
Example: There are one or
student will have mastered the
two errors in your work. It
material at this point.
looks like you misclassified
the purchase of the fax as a
cash purchase when it is really
a purchase on account.
Local
A paragraph of a paper is
Focus
Focus the student on this area
missing or the student has
of work. Point out that he does
made a number of mistakes all
not understand at least one
in one area. The student
major concept. Example:
clearly does not understand
Looking over your work, I see
this area.
that you do not understand the
concept of “on account.” Why
don't you review that concept
and review your work for
errors.
Global
The student has written on the
Redirect
Restate the goal of the activity
wrong subject or there are
and tell the student to review
mistakes all over the student's
main concepts and retry the
work.
activity. “There are lots of
mistakes throughout your
work. You need to think about
what type of transaction each
source document represents
before journalizing it.”
[0076] Returning to the analogy of helping someone write a paper, if the student writes on the wrong subject, this as a global error requiring redirect feedback. If the student returns with the paper rewritten, but with many errors in one area of the paper, focus feedback is needed. With all of those errors fixed and only spelling mistakes—syntactic mistakes—polish feedback is needed. When all syntactic mistakes were corrected, the tutor would return praise and restate why the student had written the correct paper. Focusing on the educational components of completing a task is not enough. As any teacher knows, student will often try and cheat their way through a task. Students may do no work and hope the teacher does not notice or the student may only do minor changes in hope of a hint or part of the answer. To accommodate these administrative functions, there are three additional administrative categories of feedback. The administrative and the educational categories of feedback account for every piece of feedback a designer can write and a student can receive. To provide a better understanding of how the feedback works together, an example is provided below.
[0077] FIG. 8 is a GBS display in accordance with a preferred embodiment. The upper right area of the screen shows the account list. There are four types of accounts: Assets, Liabilities & Equity, Revenues, and Expenses. The user clicks on one of the tabs to show the accounts of the corresponding type. The student journalizes a transaction by dragging an account from the account list onto the journal entry Debits or Credits. The student then enters the dollar amounts to debit or credit each account in the entry. In the interface, as in real life, the student can have multi-legged journal entries (i.e., debiting or crediting multiple accounts). A Toolbar 1200 and the first transaction of this Task 1210 appear prominently on the display. The student can move forward and back through the stack of transactions. For each transaction, the student must identify which accounts to debit and which to credit. When the student is done, he clicks the Team button. FIG. 9 is a feedback display in accordance with a preferred embodiment. The student may attempt to outsmart the system by submitting without doing anything. The ICAT system identifies that the student has not done a substantial amount of work and returns the administrative feedback depicted in FIG. 9 . The feedback points out that nothing has been done, but it also states that if the student does some work, the tutor will focus on the first few journal entries. FIG. 10 illustrates a journal entry simulation in accordance with a preferred embodiment. FIG. 11 illustrates a simulated Bell Phone Bill journal entry in accordance with a preferred embodiment. The journal entry is accomplished by debiting Utilities Expenses and Crediting Cash for $700 each. FIG. 12 illustrates a feedback display in accordance with a preferred embodiment. After attempting to journalize the first three transactions, the student submits his work and receives the feedback depicted in FIG. 12 . The feedback starts by focusing the student on the area of work being evaluated. The ICAT states that it is only looking at the first three journal entries. The feedback states that the first two entries are completely wrong, but the third is close. If the student had made large mistakes on each of the first three transactions, then the ICAT may have given redirect feedback, thinking a global error occurred. The third bullet point also highlights how specific the feedback can become, identifying near misses.
[0078] Design Scenario—This Scenario illustrates how the tools are used to support conceptual and detailed design of a BusSim application. FIG. 13 illustrates the steps of the first scenario in accordance with a preferred embodiment. The designer has gathered requirements and determined that to support the client's learning objectives, a task is required that teaches journalization skills. The designer begins the design first by learning about journalization herself, and then by using the Knowledge Workbench to sketch a hierarchy of the concepts she want the student to learn. At the most general level, she creates a root concept of ‘Journalization’. She refines this by defining sub-concepts of ‘Cash related transactions’, ‘Expense related Transactions’, and ‘Expense on account transactions’. These are each further refined to whatever level of depth is required to support the quality of the learning and the fidelity of the simulation. The designer then designs the journalization interface. Since a great way to learn is by doing, she decides that the student should be asked to Journalize a set of transactions. She comes up with a set of twenty-two documents that typify those a finance professional might see on the job. They include the gamut of Asset, Expense, Liability and Equity, and Revenue transactions. Also included are some documents that are not supposed to be entered in the journal. These ‘Distracters’ are included because sometimes errant documents occur in real life. The designer then uses the Domain Model features in the Knowledge Workbench to paint a Journal. An entity is created in the Domain Model to represent each transaction and each source document. Based on the twenty-two documents that the designer chose, she can anticipate errors that the student might make. For these errors, she creates topics of feedback and populates them with text. She also creates topics of feedback to tell the student when they have succeeded. Feedback Topics are created to handle a variety of situations that the student may cause.
[0079] The next step is to create profiles that the will trigger the topics in the concept tree (this task is not computational in nature, so the Transformation Component does not need to be configured). A profile resolves to true when its conditions are met by the student's work. Each profile that resolves to true triggers a topic. To do some preliminary testing on the design, the designer invokes the Student Simulator Test Workbench. The designer can manipulate the Domain Model as if she were the student working in the interface. She drags accounts around to different transactions, indicating how she would like them journalized. She also enters the dollar amounts that she would like to debit or credit each account. She submits her actions to the component engines to see the feedback the student would get if he had performed the activity in the same way. All of this occurs in the test bench without an application interface. The last step in this phase is low-fi user testing. A test student interacts with a PowerPoint slide or bitmap of the proposed application interface for the Journalization Task. A facilitator mimics his actions in the test bench and tells him what the feedback would be. This simplifies low-fi user testing and helps the designer to identify usability issues earlier in the design when they are much cheaper to resolve.
[0080] FIGS. 14 and 15 illustrate the steps associated with a build scenario in accordance with a preferred embodiment. The instructional designer completes the initial interaction and interface designs as seen in the previous Scenario. After low-fi user testing, the Build Phase begins. Graphic artists use the designs to create the bitmaps that will make up the interface. These include bitmaps for the buttons, tabs, and transactions, as well as all the other screen widgets. The developer builds the interface using the bitmaps and adds the functionality that notifies the Domain Model of student actions. Standard event-driven programming techniques are used to create code that will react to events in the interface during application execution and pass the appropriate information to the Domain Model. The developer does not need to have any deep knowledge about the content because she does not have to build any logic to support analysis of the student actions or feedback. The developer also codes the logic to rebuild the interface based on changes to the domain model. A few passes through these steps will typically be required to get the application communicating correctly with the components. The debug utilities and Regression Test Workbench streamline the process. After the application interface and component communication are functioning as designed, the task is migrated to Usability testing.
[0081] The Test Scenario demonstrates the cycle that the team goes through to test the application. It specifically addresses usability testing, but it is easy to see how the tools also benefit functional and cognition testing. Again, we will use the Journalization Task as an example. FIG. 16 illustrates a test scenario in accordance with a preferred embodiment. The test students work through the journalization activity. One of the students has made it over half way through the task and has just attempted to journalize the sixteenth transaction. The student submits to the Financial Coach, but the feedback comes back blank. The student notifies the facilitator who right-clicks on the Financial Coach's face in the feedback window. A dialog pops up that shows this is the twenty-seventh submission and shows some other details about the submission. The facilitator (or even the student in recent efforts) enters a text description of the problem, and fills out some other fields to indicate the nature and severity of the problem. All the student's work and the feedback they got for the twenty-seven submissions is posted to the User Acceptance Test (UAT) archive database. The instructional designer can review all the student histories in the UAT database and retrieve the session where the student in question attempted the Journalization Task. The designer then recreates the problem by replaying the student's twenty-seven submissions through the component engines using the Regression Test Workbench. The designer can then browse through each submission that the student made and view the work that the student did on the submission, the feedback the student got, and the facilitator comments, if any. Now the designer can use the debugging tools to determine the source of the problem. In a few minutes, she is able to determine that additional profiles and topics are needed to address the specific combinations of mistakes the student made. She uses the Knowledge Workbench to design the new profiles and topics. She also adds a placeholder and a script for a video war story that supports the learning under these circumstances. The designer saves the new design of the task and reruns the Regression Test Workbench on the student's session with the new task design. After she is satisfied that the new profiles, topics, and war stories are giving the desired coverage, she ships the new task design file to user testing and it's rolled out to all of the users.
[0082] Execution Scenario: Student Administration— FIG. 17 illustrates how the tool suite supports student administration in accordance with a preferred embodiment. When a student first enters a course she performs a pre-test of his financial skills and fills out an information sheet about his job role, level, etc. This information is reported to the Domain Model. The Profiling Component analyzes the pre-test, information sheet, and any other data to determine the specific learning needs of this student. A curriculum is dynamically configured from the Task Library for this student. The application configures its main navigational interface (if the app has one) to indicate that this student needs to learn Journalization, among other things. As the student progresses through the course, his performance indicates that his proficiency is growing more rapidly in some areas than in others. Based on this finding, his curriculum is altered to give him additional Tasks that will help him master the content he is having trouble with. Also, Tasks may be removed where he has demonstrated proficiency. While the student is performing the work in the Tasks, every action he takes, the feedback he gets, and any other indicators of performance are tracked in the Student Tracking Database. Periodically, part or all of the tracked data are transmitted to a central location. The data can be used to verify that the student completed all of the work, and it can be further analyzed to measure his degree of mastery of the content.
[0083] Execution Scenario: Student Interaction— FIG. 18 illustrates a suite to support a student interaction in accordance with a preferred embodiment. In this task the student is trying to journalize invoices. He sees a chart of accounts, an invoice, and the journal entry for each invoice. He journalizes a transaction by dragging and dropping an account from the chart of accounts onto the ‘Debits’ or the ‘Credits’ line of the journal entry and entering the dollar amount of the debit or credit. He does this for each transaction. As the student interacts with the interface, all actions are reported to and recorded in the Domain Model. The Domain Model has a meta-model describing a transaction, its data, and what information a journal entry contains. The actions of the student populates the entities in the domain model with the appropriate information. When the student is ready, he submits the work to a simulated team member for review. This submission triggers the Analysis-Interpretation cycle. The Transformation Component is invoked and performs additional calculations on the data in the Domain Model, perhaps determining that Debits and Credits are unbalanced for a given journal entry. The Profiling Component can then perform rule-based pattern matching on the Domain Model, examining both the student actions and results of any Transformation Component analysis. Some of the profiles fire as they identify the mistakes and correct answers the student has given. Any profiles that fire activate topics in the Remediation Component. After the Profiling Component completes, the Remediation Component is invoked. The remediation algorithm searches the active topics in the tree of concepts to determine the best set of topics to deliver. This set may contain text, video, audio, URLs, even actions that manipulate the Domain Model. It is then assembled into prose-like paragraphs of text and media and presented to the student. The text feedback helps the student localize his journalization errors and understand why they are wrong and what is needed to correct the mistakes. The student is presented with the opportunity to view a video war story about the tax and legal consequences that arise from incorrect journalization. He is also presented with links to the reference materials that describe the fundamentals of journalization. The Analysis-Interpretation cycle ends when any coach items that result in updates to the Domain Model have been posted and the interface is redrawn to represent the new domain data. In this case, the designer chose to highlight with a red check the transactions that the student journalized incorrectly.
The Functional Definition of the ICAT
[0084] This section describes the feedback processes in accordance with a preferred embodiment. For each process, there is a definition of the process and a high-level description of the knowledge model. This definition is intended to give the reader a baseline understanding of some of the key components/objects in the model, so that he can proceed with the remaining sections of this paper. Refer to the Detailed Components of the ICAT for a more detailed description of each of the components within each knowledge model. To gain a general understanding of the ICAT, read only the general descriptions. To understand the ICAT deeply, read this section and the detailed component section regarding knowledge models and algorithms. These processes and algorithms embody the feedback model in the ICAT. There are six main processes in the ICAT, described below and in more detail on the following pages.
[0085] FIG. 19 illustrates the remediation process in accordance with a preferred embodiment. Remediation starts as students interact with the application's interface (process #1). As the student tries to complete the business deliverable, the application sends messages to the ICAT about each action taken (process #2). When the student is done and submits work for review, the ICAT compares how the student completed the activity with how the designer stated the activity should be completed (this is called domain knowledge). From this comparison, the ICAT get a count of how many items are right, wrong or irrelevant (process #3). With the count complete, the ICAT tries to fire all rules (process #4). Any rules which fire activate a coach topic (process #5). The feedback algorithm selects pieces of feedback to show and composes them into coherent paragraphs of text (process #6). Finally, as part of creating feedback text paragraphs, the ICAT replaces all variables in the feedback with specifics from the student's work. This gives the feedback even more specificity, so that it is truly customized to each student's actions.
[0086] Knowledge Model—Interface Objects In any GBS Task, the student must manipulate controls on the application interface to complete the required deliverables. FIG. 20 illustrates the objects for the journalization task in accordance with a preferred embodiment. The following abstract objects are used to model all the various types of interface interactions. A SourceItem is an object the student uses to complete a task. In the journalization example, the student makes a debit and credit for each transaction. The student has a finite set of accounts with which to respond for each transaction. Each account that appears in the interface has a corresponding SourceItem object. In other words, the items the student can manipulate to complete the task (account names) are called SourceItems. A Source is an object that groups a set of SourceItem objects together. Source objects have a One-To-Many relationship with SourceItem objects. In the journalization example, there are four types of accounts: Assets, Liabilities and Equity, Revenues, and Expenses. Each Account is of one and only one of these types and thus appears only under the appropriate tab. For each of the Account type tabs, there is a corresponding Source Object. A Target is a fixed place where students place SourceItems to complete a task. in the journalization example, the student places accounts on two possible targets: debits and credits. The top two lines of the journal entry control are Debit targets and the bottom two lines are Credit targets. These two targets are specific to the twelfth transaction. A TargetPage is an object that groups a set of Target objects together. TargetPage objects have a One-To-Many relationship with Target objects (just like the Source to SourceItem relationship). In the journalization example, there is one journal entry for each of the twenty-two transactions. For each journal entry there is a corresponding TargetPage object that contains the Debits Target and Credits Target for that journal entry.
[0087] As the student manipulates the application interface, each action is reported to the ICAT. In order to tell the ICAT what actions were taken, the application calls to a database and asks for a specific interface control's ID. When the application has the ID of the target control and the SourceItem control, the application notifies the ICAT about the Target to SourceItem mapping. In other words, every time a student manipulates a source item and associates it with a target (e.g., dragging an account name to a debit line in the journal), the user action is recorded as a mapping of the source item to the target. This mapping is called a UserSourceItemTarget. FIG. 21 illustrates the mapping of a source item to a target item in accordance with a preferred embodiment. When the student is ready, he submits his work to one of the simulated team members by clicking on the team member's icon. When the ICAT receives the student's work, it calculates how much of the work is correct by concept. Concepts in our journalization activity will include Debits, Credits, Asset Accounts, etc. For each of these concepts, the ICAT will review all student actions and determine how many of the student actions were correct. In order for the ICAT to understand which targets on the interface are associated with each concept, the targets are bundled into target groups and prioritized in a hierarchy. Once all possible coach topics are activated, a feedback selection analyzes the active pieces of remediation within the concept hierarchy and selects the most appropriate for delivery. The selected pieces of feedback are then assembled into a cohesive paragraph of feedback and delivered to the student. FIG. 23 illustrates a feedback selection in accordance with a preferred embodiment. After the ICAT has activated CoachTopics via Rule firings, the Feedback Selection Algorithm is used to determine the most appropriate set of CoachItems (specific pieces of feedback text associated with a CoachTopic) to deliver. The Algorithm accomplishes this by analyzing the concept hierarchy (TargetGroup tree), the active CoachTopics, and the usage history of the CoachItems. FIG. 24 is a flowchart of the feedback logic in accordance with a preferred embodiment. There are five main areas to the feedback logic which execute sequentially as listed below. First, the algorithm looks through the target groups and looks for the top-most target group with an active coach topic in it. Second, the algorithm then looks to see if that top-most coach item is praise feedback. If it is praise feedback, then the student has correctly completed the business deliverable and the ICAT will stop and return that coach item. Third, if the feedback is not Praise, then the ICAT will look to see if it is redirect, polish, mastermind or incomplete-stop. If it is any of these, then the algorithm will stop and return that feedback to the user. Fourth, if the feedback is focus, then the algorithm looks to the children target groups and groups any active feedback in these target groups with the focus group header. Fifth, once the feedback has been gathered, then the substitution language is run which replaces substitution variables with the proper names. Once the ICAT has chosen the pieces of feedback to return, the feedback pieces are assembled into a paragraph. With the paragraph assembled, the ICAT goes through and replaces all variables. There are specific variables for SourceItems and Targets. Variables give feedback specificity. The feedback can point out which wrong SourceItems were placed on which Targets. It also provides hints by providing one or two SourceItems which are mapped to the Target.
THE STEPS INVOLVED IN CREATING FEEDBACK IN ACCORDANCE WITH A PREFERRED EMBODIMENT
[0088] The goal of feedback is to help a student complete a business deliverable. The tutor needs to identify which concepts the student understands and which he does not. The tutor needs to tell the student about his problems and help him understand the concepts. There are seven major steps involved in developing feedback for an application. First, creating a strategy—The designer defines what the student should know. Second, limit errors through interface—The designer determines if the interface will identify some low level mistakes. Third, creating a target group hierarchy—The designer represents that knowledge in the tutor. Fourth, sequencing the target group hierarchy—The designer tells the tutor which concepts should be diagnosed first. Fifth, writing feedback—The designer writes feedback which tells the student how he did and what to do next. Sixth, writing Levels of Feedback—The designer writes different levels of feedback in case the student makes the same mistake more than once. Seventh, writing rules—The designer defines patterns which fire the feedback.
[0089] A feedback strategy is a loose set of questions which guide the designer as he creates rules and feedback. The strategy describes what the student should learn, how he will try and create the business deliverable and how an expert completes the deliverable. The goal of the application should be for the student to transition from the novice model to the expert model. What should the student know after using the application? The first task a designer needs to complete is to define exactly what knowledge a student must learn by the end of the interaction. Should the student know specific pieces of knowledge, such as formulas? Or, should the student understand high level strategies and detailed business processes? This knowledge is the foundation of the feedback strategy. The tutor needs to identify if the student has used the knowledge correctly, or if there were mistakes. An example is the journal task. For this activity, students need to know the purpose of the journalizing activity, the specific accounts to debit/credit, and how much to debit/credit. A student's debit/credit is not correct or incorrect in isolation, but correct and incorrect in connection with the dollars debited/credited. Because there are two different types of knowledge—accounts to debit/credit and amounts to debit/credit—the feedback needs to identify and provide appropriate feedback for both types of mistakes.
[0090] How will a novice try and complete the task? Designers should start by defining how they believe a novice will try and complete the task. Which areas are hard and which are easy for the student. This novice view is the mental model a student will bring to the task and the feedback should help the student move to an expert view. Designers should pay special attention to characteristic mistakes they believe the student will make. Designers will want to create specific feedback for these mistakes. An example is mixing up expense accounts in the journal activity. Because students may mix up some of these accounts, the designer may need to write special feedback to help clear up any confusion.
[0091] How does an expert complete the task? This is the expert model of completing the task. The feedback should help students transition to this understanding of the domain. When creating feedback, a designer should incorporate key features of the expert model into the praise feedback he writes. When a student completes portion of the task, positive reinforcement should be provided which confirms to the student that he is doing the task correctly and can use the same process to complete the other tasks. These four questions are not an outline for creating feedback, but they define what the feedback and the whole application needs to accomplish. The designer should make sure that the feedback evaluates all of the knowledge a student should learn. In addition, the feedback should be able to remediate any characteristic mistakes the designer feels the student will make. Finally, the designer should group feedback so that it returns feedback as if it were an expert. With these components identified, a designer is ready to start creating target group hierarchies. Because there are positive and negative repercussions, designers need to select the when to remediate through the interface carefully. The criteria for making the decision is if the mistake is a low level data entry mistake or a high level intellectual mistake. If the mistake is a low level mistake, such as miss-typing data, it may be appropriate to remediate via the interface. If the designer decides to have the interface point out the mistakes, it should look as if the system generated the message. System generated messages are mechanical checks, requiring no complex reasoning. In contrast, complex reasoning, such as why a student chose a certain type of account to credit or debit should be remediated through the ICAT.
[0092] System messages—it is very important that the student know what type of remediation he is going to get from each source of information. Interface based remediation should look and feel like system messages. They should use a different interface from the ICAT remediation and should have a different feel. In the journalization task described throughout this paper, there is a system message which states “Credits do not equal debits.” This message is delivered through a different interface and the blunt short sentence is unlike all other remediation. The motivation for this is that low level data entry mistakes do not show misunderstanding but instead sloppy work. Sloppy-work mistakes do not require a great deal of reasoning about why they occurred instead, they simply need to be identified. High-level reasoning mistakes, however, do require a great deal of reasoning about why they occurred, and the ICAT provides tools, such as target groups, to help with complex reasoning. Target group hierarchies allow designers to group mistakes and concepts together and ensure that they are remediated at the most appropriate time (i.e., Hard concepts will be remediated before easy concepts). Timing and other types of human-like remediation require the ICAT; other low-level mistakes which do not require much reasoning include: Incomplete-If the task requires a number of inputs, the interface can check that they have all been entered before allowing the student to proceed. By catching empty fields early in the process, the student may be saved the frustration of having to look through each entry to try and find the empty one. Empty-A simple check for the system is to look and see if anything has been selected or entered. If nothing has been selected, it may be appropriate for the system to generate a message stating “You must complete X before proceeding”. Numbers not matching-Another quick check is matching numbers. As in the journalization activity, is often useful to put a quick interface check in place to make sure numbers which must match do. Small data entry mistakes are often better remediated at the interface level than at the tutor or coach level (when they are not critical to the learning objectives of the course). There are two main issues which must be remembered when using the interface to remediate errors. First, make sure the interface is remediating low level data entry errors. Second, make sure the feedback looks and feels different from the ICAT feedback. The interface feedback should look and feel like it is generated from the system while the ICAT feedback must look as if it were generated from an intelligent coach who is watching over the student as he works.
[0093] Creating the Target Group Hierarchy—Target groups are sets of targets which are evaluated as one. Returning to the severity principle of the feedback theory, it is clear that the tutor needs to identify how much of the activity the student does not understand. Is it a global problem and the student does not understand anything about the activity? Or, is it a local problem and the student simply is confused over one concept? Using the feedback algorithm described earlier, the tutor will return the highest target group in which there is feedback. This algorithm requires that the designer start with large target groups and make sub-groups which are children of the larger groups. The ICAT allows students to group targets in more than one category. Therefore a debit target for transaction thirteen can be in a target group for transaction thirteen entries as well as a target group about debits and a target group which includes all source documents. Target should be grouped with four key ideas in mind. Target groups are grouped according to: Concepts taught; Interface constraints; Avoidance of information overload and Positive reinforcement.
[0094] The most important issue when creating target groups is to create them along the concepts students need to know to achieve the goal. Grouping targets into groups which are analogous to the concepts a student needs to know, allows the tutor to review the concepts and see which concepts confuse the student. As a first step, a designer should identify in an unstructured manner all of the concepts in the domain. This first pass will be a large list which includes concepts at a variety of granularities, from small specific concepts to broad general concepts. These concepts are most likely directly related to the learning objectives of the course. With all of the concepts defined, designers need to identify ail of the targets which are in each target group. Some targets will be in more than one target group. When a target is in more than one target group, it means that there is some type of relationship such as a child relationship or a part to whole relationship. The point is not to create a structured list of concepts but a comprehensive list. Structuring them into a hierarchy will be the second step of the process.
[0000]
* Notes: Loads from Database or Document based on values
* of m_StorageTypeTask and m_StorageTypeStudent
*
**************************
*/
extern “C”
{
long_export WINAPI TuResumeStudent (long StudentID,
long TaskID, int fromSubmissionSeqID); //Resumes a Student's work for
the Task at the specified Submission
}
extern “C”
{
long _export WINAPI TuLoadArchivedSubmissions(long
StudentID, long TaskID, int from SubmissionSeqID, int
toSubmissionSeqID); // Loads Archived Submissions For a Student's work
in Task
}
extern “C”
{
long _export WINAPI ToUseArchivedSubmissions(int n);
//Replays n Archived submissions for debugging
}
extern “C”
{
long _export WINAPI TuSaveCurrentStudent( ); //Saves Current
Student's work to DB
}
extern “C”
{
long _export WINAPI KillEngine(long ITaskID); //Delete all
Dynamic objects before shutdown
*Function Return
*Variables: TUT_ERR_OK
*
*Notes:
*************************
*/
extern “C”
{
long _export WINAPI TuSetTaskDocPathName(LPCSTR fnm);
}
/*
*************************
*Name: TuSetFeedbackFileName
*Purpose: To set path and name of file to use for holding feedback
*Input
*Parameters: LPCSTR fnm
* Path and name of file to use for holding feedback
*Output
*Parameters: none
*
*Function Return
*Variables: TUT_ERR_OK
*
*Notes:
*******************************
*/
extern “C”
{
long _export WINAPI TuSetFeedbackFileName( LPCSTR fnm);
}
/*
********************************
*Name: TuSetFeedbackPrevFileName
*Purpose: To set path and name of file to use for holding previous
feedback
*Input
*Parameters: LPCSTR fnm
* Path and name of file to use for holding feedback
*Output
*Parameters: none
*
*Function Return
*Variables: TUT_ERR_OK
*Notes:
********************************
*/
extern “C”
{
long _exportWINAPI TuSetFeedbackPrevFileName(LPCSTR fnm);
/*
****************************
*Name: TuSetLogFileName
*Purpose: To set path and name of file to use for full logging
*Input
*Parameters: LPCSTR fnm
* Path and name of file to use for full logging
*Output
*Parameters: none
*
*Function Return
*Variables: TUT_ERR_OK
*Notes:
******************************
*/
extern “C”
{
long _exportWINAPI TuSetLogFileName(LPCSTR fnm);
}
/*
******************************
*Name: TuSetLogLoadFileName
*Purpose: To set path and name of file to use for load logging
*Input
*Parameters: LPCSTR fnm
* Path and name of file to use for load logging
*Output
*Parameters: none
*
*Function Return
*Variables: TUT_ERR_OK
*
*Notes:
*****************************
*/
extern “C”
{
long _export WINAPI TuSetLogLoadFileName(LPCSTR fnm);
}
/*
*****************************
*Name: TuSetLogStudentFileName
*Purpose: To set path and name of file to use for student logging
*Input
*Parameters: LPCSTR fnm
* Path and name of file to use for student logging
*Output
*Parameters: none
*
*Function Return
*Variables: TUT_ERR_OK
*
*Notes:
*****************************
*
extern “C”
{
long _export WINAPI TuSetLogStudentFileName(LPCSTR fnm);
}
/*
****************************
*Name: TuSetLogSubmissionFileName
*Purpose: To set path and name of file to use for submission logging
*Input
*Parameters: LPCSTR fnm
* Path and name of file to use for submission logging
*Output
*Parameters: none
*
*Function Return
*Variables: TUT_ERR_OK
*
*Notes:
***************************
*/
extern “C”
{
long _export WINAPI TuSetLogSubmissionFileName( LPCSTR
fnm);
}
/*
****************************
*Name: TuSetLogErrFileName
*Purpose: To set path and name of file to use for error logging
*Input
*Parameters: LPCSTR fnm
* Path and name of file to use for error logging
*Output
*Parameters: none
*
*Function Return
*Variables: TUT_ERR_OK
*Notes:
***************************
*/
extern “C”
{
long _export WINAPI TuSetLogErrFileName (LPCSTR fnm);
}
/*
***************************
*Name: TuSetTrace
*Purpose: To turn Trace on and off
*Input
*Parameters: int TraceStatus
* TUT_TRACE_ON :Turn Trace On
* TUT_TRACE_OFF :Turn Trace Off
*Output
*Parameters: none
*
*Function Return
*Variables: Previous Trace Status Value
* TUT_TRACE_ON
* TUT_TRACE_OFF
*
* TUT_ERR_INVALID_TRACE_STATUS
*Notes:
***************************
*/
extern “C”
{
long _export WINAPI TuSetTrace (int TraceStatus);
}
/*
*****************************
*Name: TuSetTrack
*Purpose: To turn Tracking on and off. While tracking is on all the work
the user does and all feedback the user received is kept. While
Tracking is off only the most recent work is kept.
*Input
*Parameters: int TrackStatus
* TUT_TRACK_ON :Turn Tracking On
* TUT_TRACK_OFF :Turn Tracking Off
*Output
*Parameters: none
*Function Return
*Variables: Previous Trace Status Value
* TUT_TRACK_ON
* TUT_TRACK_OFF
*
* TUT_ERR_INVALID_TRACE_STATUS
*Notes:
**************************
*/
extern “C”
{
long _export WINAPI TuSetTrack (int TrackStatus);
}
Simulation Engine
[0095] The idea is for the designer to model the task that he wants a student to accomplish using an Excel spreadsheet. Then, have an algorithm or engine that reads all the significant cells of the spreadsheet and notifies the Intelligent Coaching Agent with the appropriate information (SourceItemID, TargetID and Attribute). This way, the spreadsheet acts as a central repository for student data, contains most of the calculations required for the task and in conjunction with the engine handles all the communication with the ICA. The task is self contained in the spreadsheet, therefore the designers no longer need a graphical user interface to functionally test their designs (smart spreadsheet. Once the model and feedback for it are completely tested by designers, developers can incorporate the spreadsheet in a graphical user interface, e.g., Visual Basic as a development platform. The simulation spreadsheet is usually invisible and populated using functions provided by the engine. It is very important that all modifications that the ICA needs to know about go through the engine because only the engine knows how to call the ICA. This significantly reduced the skill level required from programmers, and greatly reduced the time required to program each task. In addition, the end-product was less prone to bugs, because the tutor management was centralized. If there was a tutor problem, we only had to check on section of code. Finally, since the simulation engine loaded the data from a spreadsheet, the chance of data inconsistency between the tutor and the application was nil.
[0096] FIG. 25 is a block diagram setting forth the architecture of a simulation model in accordance with a preferred embodiment. The Simulation Object Model consists of a spreadsheet model, a spreadsheet control object, a simulation engine object, a simulation database, input objects, output objects, list objects and path objects. The first object in our discussion is the Spreadsheet object. The Spreadsheet is the support for all simulation models. A control object that is readily integrated with the Visual Basic development plat. The control supports printing and is compatible with Microsoft Excel spreadsheets. With that in mind, designers can use the power of Excel formulas to build the simulation. The different cells contained in the spreadsheet model can be configured as Inputs, Outputs or Lists and belong to a simulation Path. All cells in the spreadsheet that need to be manually entered by the designer or the student via the GBS application are represented by input objects. Every input has the following interface:
[0000]
Field Name
Data Type
Description
InputID
long
Primary Key for the table
TaskID
long
TaskID of the task associated with the
input
PathID
long
PathID of the path associated with the
input
InputName
string*50
Name of the input
InputDesc
string*255
Description of the
input
ReferenceName
string*50
Name of the spreadsheet cell associated
with the input
TutorAware
boolean
Whether the ICA should be notified of any
changes to the input
SourceItemID
long
SourceItemID if input is a distinct input;
0 if input is a drag drop input
TargetID
long
TargetID of the input
Row
long
Spreadsheet row number of the
input →speed optimization
Column
long
Spreadsheet column number of the
input →speed optimization
SheetName
string*50
Sheet name were the input is
located →speed optimization
[0097] This information is stored for every input in the Input table of the simulation database (ICASim. mdb). Refer to the example below. When designers construct their simulation model, they must be aware of the fact that there are 2 types of Inputs: Distinct Input & Drag & Drop Input. The Distinct Input consists of a single spreadsheet cell that can be filled by the designer at design time or by the GBS application at run time via the simulation engine object's methods. The purpose of the cell is to provide an entry point to the simulation model. This entry point can be for example an answer to a question or a parameter to an equation. If the cell is TutorAware (all inputs are usually TutorAware), the ICA will be notified of any changes to the cell. When the ICA is notified of a change two messages are in fact sent to the ICA: An ICANotifyDestroy message with the input information i.e., SourceItemID, TargetID and null as Attribute. This message is to advise the ICA to remove this information from its memory. An ICANotifyCreate message with the input information i.e., SourceItemID, TargetID, Attribute (cell numeric value). This message is to advise the ICA to add this information to its memory. A Distinct Input never requires that a user answer a mathematics question.
[0098] These are the steps required to configure that simulation: Define a name for cell C2 in Excel. Here we have defined “Distinct-input”. In the ICA, define a task that will be assigned to the simulation. Ex: a TaskiD of 123 is generated by the ICA. In the ICA, define a Target for the input. Ex: a TargetID of 4001 is generated by the ICA. In the ICA, define a SourceItem for the input. Ex: a SourceItemID of 1201 is generated by the ICA. Associate the input to a path (refer to Path object discussion). Add the information in the Input table of the simulation engine database. A record in an input table is presented below.
[0000]
InputID:
12345
TaskID:
123
PathID:
1234
InputName:
Question 1 input
InputDesc:
Distinct input for Question 1
ReferenceName:
Distinct_input
TutorAware:
True
SourceItemID
1201
TargetID:
4001
Row:
2
Column:
3
SheetName:
Sheet1
[0099] The Row, Column and SheetName are filled in once the user clicks “Run Inputs/Outputs”. The simulation engine decodes the defined name (Reference Name) that the designer entered, and populates the table accordingly. This is an important step. We had several occasions when a designer would change the layout of a spreadsheet, i.e., move a defined name location, then forget to perform this step. As such, bizarre data was being passed to the tutor; whatever data happened to reside in the old row and column. Once the configuration is completed, the designer can now utilize the ICA Utilities to test the simulation.
[0100] The drag & drop input consist of two consecutive spreadsheet cells. Both of them have to be filled by the designer at design time or by the GBS application at run time via the simulation engine object's methods. This type of input is used usually when the user must choose one answer among a selection of possible answers. Drag & drop inputs are always TutorAware. The left most cell contains the SourceItemID of the answer picked by the user (every possible answer needs a SourceItemID) and the rightmost cell can contain a numeric value associated to that answer. You need to define a name or ReferenceName in the spreadsheet for the rightmost cell. ICA will be notified of any changes to either one of the cells. When the ICA is notified of a change two messages are in fact sent to the ICA: An ICANotifyDestroy message with the input information i.e., SourceItemID before the change occurred, TargetID of the input and the Attribute value before the change occurred. An ICANotifyCreate message with the input information i.e., SourceItemID after the change occurred, TargetID of the input and the Attribute value after the change occurred.
[0101] These are the steps required to configure that section of the simulation: Define a name for cell C11 in Excel. Here we have defined “DragDrop_Input”; Let's use the same TaskID as before since Question 2 is part of the same simulation as Question 1. Ex: TaskID is 123; In the ICA, define a Target for the input. Ex: a TargetID of 4002 is generated by the ICA; In the ICA, define a SourceItem for every possible answer to the question. Ex: SourceItemIDs 1202 to 1205 are generated by the ICA; Associate the input to a path (refer to Path object discussion); and Add the information in the Input table of the simulation engine database. A record in the Input table in accordance with a preferred embodiment is presented below.
[0000]
InputID:
12346
TaskID:
123
PathID:
1234
InputName:
Question 2 input
InputDesc:
Drag & Drop input for Question 2
ReferenceName:
DragDrop_Input
TutorAware:
True
SourceItemID
0***
TargetID:
4002
Row:
11
Column:
3
SheetName:
Sheet1
[0102] The list object consists of one cell identifying the list (cell #1) and a series of placeholder rows resembling drag & drop inputs (cells #1.1-1.n to cells #n.1-n.n). The list is used usually when the user must choose multiple elements among a selection of possible answers. Cell #1 must have a uniquely defined name also called the list name. Cells #1.1 to #n.1 can contain the SourceItemID of one possible answer picked by the user (every possible answer needs a SourceItemID). The content of these cells must follow this format: ˜ListName˜SourceItemID. Cells#1.2 to #n.2 will hold the numeric value (attribute) associated with the SourceItemID in the cell immediately to the left. Cells #1.3-1.n to #n.3-n.n are optional placeholders for data associated with the answer. KEY NOTE: When implementing a list object the designer must leave all the cells under #n.1 to #n.n blank because this range will shift up every time an item is removed from the list.
[0103] Every list has the following interface:
[0000]
Field Name
Data Type
Description
ListID
long
Primary Key for the table
TaskID
long
TaskID of the task associated with the list
PathID
long
PathID of the path associated with the list
ListName
string*50
Name of the list
ListDesc
string*255
Description of the list
ReferenceName
string*50
Name of the spreadsheet cell associated
with the list
TutorAware
boolean
Whether the ICA should be notified of any
changes to the list
TargetID
long
TargetID if output
TotalColumns
long
Total number of data columns
Row
long
Spreadsheet row number of the
output →speed optimization
Column
long
Spreadsheet column number of the
output →speed optimization
SheetName
string*50
Sheet name were the input is
located →speed optimization
[0104] Use of a list is demonstrated by continuing our math test. The math question in this example invites the user to select multiple elements to construct the answer. These are the steps required to configure that section of the simulation. FIG. 26 illustrates the steps for configuring a simulation in accordance with a preferred embodiment. Define a name for cell C23 in Excel. Here we have defined “The_List”. Let's use the same TaskID as before since Question 3 is part of the same simulation as Question 1 and 2. Ex: TaskID is 123. In the ICA, define a Target for the list. Ex: a TargetID of 4006 is generated by the ICA. In the ICA, define a SourceItem for every item that could be placed in the list. Ex: the following SourceItemIDs 1209, 1210, 1211, 1212, 1213, 1214 are generated by the ICA. Associate the list to a path (refer to Path object discussion). Add the information in the List table of the simulation engine database.
[0105] A record in the List table in accordance with a preferred embodiment is presented in the table appearing below.
[0000]
ListID:
12346
TaskID:
123
PathID:
1234
ListName:
Question 3 list
ListDesc:
List for Question 3
ReferenceName:
The_List
TutorAware:
True
TargetID
4006
TotalColumns:
1
Row:
23
Column:
3
SheetName:
Sheet1
[0106] All cells in the spreadsheet that are result of calculations (do not require any external input) can be represented by output objects. Every output has an interface as outlined in the table below.
[0000]
Field Name
Data Type
Description
OutputID
long
Primary Key for the table
TaskID
long
TaskID of the task associated with the
output
PathID
long
PathID of the path associated with the
output
OutputName
string*50
Name of the output
OutputtDesc
string*255
Description of the output
ReferenceName
string*50
Name of the spreadsheet cell associated
with the output
TutorAware
boolean
Whether the ICA should be notified of any
changes to the output
SourceItemID
long
SourceItemID if output
TargetID
long
TargetID of the output
Row
long
Spreadsheet row number of th
output →speed optimization
Column
long
Spreadsheet column number of the
output →speed optimization
SheetName
string*50
Sheet name were the input is
located →speed optimization
[0107] All this information is stored for every output in the Output table of the simulation database (ICASim.mdb). When designers construct their simulation model, they must be aware of the fact that there is only 1 type of Outputs: the Distinct Output. A Distinct Output consists of one and only one spreadsheet cell that contains a formula or a result of calculations. The existence of Output cells is the main reason to have a simulation model. If the cell is TutorAware, the ICA will be notified of any changes to the cell when all outputs are processed otherwise the ICA will be unaware of any changes. When the ICA is notified of a change two messages are in fact sent to the ICA: An ICANotifyDestroy message with the output information i.e., SourceItemID, TargetID and null as Attribute. This message is to advise the ICA to remove this information from its memory. An ICANotifyCreate message with the output information i.e., SourceItemID, TargetID, Attribute (cell numeric value). This message is to advise the ICA to add this information to its memory. As opposed to Distinct Inputs and Drag & Drop Inputs which notify the ICA on every change, Distinct Outputs are processed in batch just before asking the ICA for feedback. To notify the ICA of the total dollar amount of the items in the list. We definitely need a Distinct Output for that. The output will contain a sum formula. Define a name for cell C24 in Excel. Here we have defined “DistinctOutput”. Let's use the same TaskiD as before since Question 3 is part of the same simulation as Question 1 and 2. Ex: TaskID is 123. In the ICA, define a Target for the output. Ex: a TargetID of 4005 is generated by the ICA. In the ICA, define a SourceItem for the output. Ex: a SourceItemID of 1215 is generated by the ICA. Associate the output to a path (refer to Path object discussion). Add the information in the Output table of the simulation engine database.
[0108] A record in an Output table in accordance with a preferred embodiment is presented below.
[0000]
OutputID:
12347
TaskID:
123
PathID:
1234
OutputName:
Question 3 output
OutputDesc:
Distinct Output for Question 3
ReferenceName:
Distinct_Output
TutorAware:
True
SourceItemID
1215
TargetID
4005
Row:
24
Column:
6
SheetName:
Sheet1
[0109] Paths are used to divide a simulation model into sub-Simulations meaning that you can group certain inputs, outputs and lists together to form a coherent subset or path. Every path has the following interface:
[0000]
Field Name
Data Type
Description
PathID
long
Primary Key for the table
TaskID
long
TaskID of the task associated with the path
PathNo
long
Numeric value associated with to a path
PathName
string*50
Name of the path
PathDesc
string*255
Description of the path
[0110] All this information is stored for every path in the path table of the simulation database (ICASim.mdb).
[0111] The simulation engine is the interface between the model, the simulation database and the Intelligent Coaching Agent. The simulation engine is of interest to the designer so that he can understand the mechanics of it all. But it is the developer of applications using the engine that should know the details of the interface (methods & properties) exposed by the engine and the associated algorithms. Once the designer has constructed the simulation model (Excel Spreadsheet) and configured all the inputs, outputs & lists, he is ready to test using the test bench included in the ICA Utilities (refer to ICA Utilities documentation). The developer, in turn, needs to implement the calls to the simulation engine in the GBS application he's building. The following list identifies the files that need to be included in the Visual Basic project to use the simulation workbench:
[0000]
wSimEng.cls
Simulation Engine class
wSimEng.bas
Simulation Engine module (this module was introduced
only for speed purposes because all the code
should theoretically be encapsulated in the class)
wConst.bas
Intelligent Coaching Agent constant declaration
wDeclare.bas
Intelligent Coaching Agent DLL interface
wlca.cls
Intelligent Coaching Agent class
wlca.bas
Intelligent Coaching Agent module (this module was
introduced only for speed purposes because all the
code should theoretically be encapsulated in the class)
[0112] To have a working simulation, a developer places code in different strategic areas or stages of the application. There's the Initial stage that occurs when the form containing the simulation front-end loads. This is when the simulation model is initialized. There's the Modification stages that take place when the user makes changes to the front-end that impacts the simulation model. This is when the ICA is notified of what's happening. There's the Feedback stage when the user requests information on the work done so far. This is when the simulation notifies the ICA of all output changes. Finally, there's the Final stage when the simulation front-end unloads. This is when the simulation is saved to disk.
[0113] The different stages of creating a simulation, including the Visual Basic code involved, are presented below. Initial stage; 1. Creating the ICA & the simulation engine object: Code: Set moSimEngine=New classSimEngine; Set moICA=New classICA; Description: The first step in using the simulation engine is to create an instance of the class classSimEngine and also an instance of the class classICA. Note that the engine and ICA should be module level object “mo” variables. 2. Loading the simulation; Code: IRet=moSimEngine. OpenSimulation (App Path & DIR_DATA & FILE_SIMULATION, Me.bookSimulation); IRet=moSimEngine. LoadSimulation (miICATaskID, App.Path & DIR_DATABASE & DB_SIMULATION, 1); Description: After the object creation, the OpenSimulation and LoadSimulation methods of the simulation engine object must be called. The OpenSimulation method reads the specified Excel 5.0 spreadsheet file into a spreadsheet control. The LoadSimulation method opens the simulation database and loads into memory a list of paths, a list of inputs, a list of outputs and a list of lists for the specific task. Every method of the simulation engine will return 0 if it completes successfully otherwise an appropriate error number is returned. 3. Initializing and loading the Intelligent Coaching Agent; Code: IRet=moICA.Initialize (App.Path & “\” & App.EXEName & “.ini”, App.Path & DIR_DATABASE, App.Path & DIR ICADOC, App.Path & “\”); IRet=moICA.LoadTask (mIICATaskID, ICAStudentStartNew); Description: The simulation engine only works in conjunction with the ICA. The Initialize method of the ICA object reads the application .ini file and sets the Tutor32.dll appropriately. The LoadTask method tells the ICA (Tutor32.dll) to load the .tut document associated to a specific task in memory. From that point on, the ICA can receive notifications. Note: The .tut document contains all the element and feedback structure of a task. Ex: SourcePages, SourceItems, TargetPages, Targets, etc. . . . 4. Restoring the simulation; Code: <<Code to reset the simulation when starting over >>; <<Code to load the controls on the simulation front-end>>; IRet=moSimEngine.Runinputs(sPaths, True); IRet moSimEngine.RunOutputs(sPaths, True); IRet=moSimEngine.RunLists (spaths, True); Call moICA.Submit(0); Call moICA.SetDirtyFlag(0, False); Description: Restoring the simulation involves many things: clearing all the inputs and lists when the user is starting over; loading the interface with data from the simulation model; invoking the RunInputs, RunOutputs and RunLists methods of the simulation engine object in order to bring the ICA to it's original state; calling the Submit method of the ICA object with zero as argument to trigger all the rules; calling the SetDirtyFlag of the ICA object with 0 and false as arguments in order to reset the user's session. Running inputs involves going through the list of TutorAware inputs and notifying the ICA of the SourceItemID, TargetID and Attribute value of every input. Running lists involves going through the list of TutorAware lists and notifying the ICA of the SourceItemID, TargetID and Attribute value of every item in every list. The TargetID is unique for every item in a list.
[0114] Running outputs involves going through the list of TutorAware outputs and notifying the ICA of the SourceItemID, TargetID and Attribute value of every output. Modification stage 1. Reading inputs & outputs; Code: Dim sDataArray(2) as string; Dim vAttribute as variant; Dim ISourceItemID as long; Dim ITargetID as long; IRet=moSimEngine.ReadReference (“Distinct_input”, vAttribute, ISourceItemID, ITargetID, sDataArray)
[0115] Description: The ReadReference method of the simulation object will return the attribute value of the input or output referenced by name and optionally retrieve the SourceItemID, TargetID and related data. In the current example, the attribute value, the SourceItemID, the TargetID and 3 data cells will be retrieved for the input named Distinct-Input.
[0116] Description: The simulation engine object provides basic functionality to manipulate lists. The ListAdd method appends an item (SourceItemID, Attribute, Data array) to the list. Let's explain the algorithm. First, we find the top of the list using the list name. Then, we seek the first blank cell underneath the top cell. Once the destination is determine, the data is written to the appropriate cells and the ICA is notified of the change. The ListCount method returns the number of items in the specified list. The algorithm works exactly like the ListAdd method but returns the total number of items instead of inserting another element. The ListModify method replaces the specified item with the provided data. Let's explain the algorithm. First, we find the top of the list using the list name. Second, we calculate the row offset based on the item number specified. Then, the ICA is notified of the removal of the existing item. Finally, the data related to the new item is written to the appropriate cells and the ICA is notified of the change. The ListDelete method removes the specified item. The algorithm works exactly like the ListModify method but no new data is added and the cells (width of the list set by ‘Total Columns’) are deleted with the ‘move cells up’ parameter set to true. Keep this in mind, as designers often enter the wrong number of columns in the Total Columns parameter. When they overestimate the Total Columns, ListDelete will modify portions of the neighboring list, which leads to erratic behavior when that list is displayed.
SYSTEM DYNAMICS IN ACCORDANCE WITH A PREFERRED EMBODIMENT
[0117] To use system dynamics models in the architecture, an engine had to be created that would translate student work into parameters for these models. A complex system dynamics model to interact with an existing simulation architecture is discussed below. The system dynamics model provides the following capabilities. Allow designers to build and test their system dynamics models and ICA feedback before the real interface is built. Reduce the programming complexity of the activities. Centralize the interactions with the system dynamics models. System Dynamics Engine As with the simulation engine, the designer models the task that he/she wants a student to accomplish using a Microsoft Excel spreadsheet. Here, however, the designer also creates a system dynamics model (described later). The system dynamics engine will read all of the significant cells within the simulation model (Excel) and pass these values to the system dynamics model and the ICA. After the system dynamics model runs the information, the output values are read by the engine and then passed to the simulation model and the ICA.
[0118] FIG. 27 is a block diagram presenting the detailed architecture of a system dynamics model in accordance with a preferred embodiment. Once the simulation model, system dynamics model and feedback are completely tested by designers, developers can incorporate the spreadsheet in a graphical user interface, e.g., Visual Basic as a development platform. FIG. 27 illustrates that when a student completes an activity, the values are passed to the system dynamics engine where the values are then passed to the system dynamics model (as an input), written to the simulation model and submitted to the ICA. When the system dynamics model is played, the outputs are pulled by the engine and then passed to the simulation model and the ICA. Note that the simulation model can analyze the output from the system dynamics model and pass the results of this analysis to the ICA as well. The simulation model can then be read for the output values and used to update on-screen activity controls (such as graphs or reports). It is very important that all modifications that the ICA and system dynamics model need to know about go through the engine because only the engine knows how to call these objects. This significantly reduces the skill level required from programmers, and greatly reduces the time required to program each task. In addition, the end-product is less prone to bugs, because the model and tutor management will be centralized. If there is a problem, only one section of code needs to be checked. Finally, since the engine loads the data from the spreadsheet, the chance of data inconsistency between the ICA, the system dynamics model and the application is insignificant.
[0119] The system dynamics model generates simulation results over time, based on relationships between the parameters passed into it and other variables in the system. A system dynamics object is used to integrate with Visual Basic and the spreadsheet object. The object includes logic that controls the time periods as well as read and write parameters to the system dynamics model. With Visual Basic, we can pass these parameters to and from the model via the values in the simulation object. The system dynamics object also controls the execution of the system dynamics model. What this means is that after all of the parameter inputs are passed to the system dynamics model, the engine can run the model to get the parameter outputs. The system dynamics object allows for the system dynamics models to execute one step at a time, all at once, or any fixed number of time periods. When the system dynamics model runs, each step of the parameter input and parameter output data is written to a ‘backup’ sheet for two reasons. First, the range of data that is received over time (the model playing multiple times) can be used to create trend graphs or used to calculate statistical values. Second, the system dynamics model can be restarted and this audit trail of data can be transmitted into the model up to a specific point in time. What this means is that the engine can be used to play a simulation back in time. When any event occurs within the system dynamics engine, a log is created that tells the designers what values are passed to the simulation model, system dynamics model and ICA as well as the current time and the event that occurred. The log is called “SysDyn.log” and is created in the same location as the application using the engine. As with the spreadsheet object, the system dynamics object allows a large amount of the calculations to occur in the system dynamics model and not in the activity code, again placing more control with the activity designers. Model objects are used to configure the system dynamics models with regard to the time periods played. Models are what the parameter inputs and parameter outputs (discussed later) relate to, so these must be created first. Every model has the following application programming interface:
[0000]
Field Name
Data Type
Description
ModelID
Long
Primary Key for the table
TaskID
Long
TaskID of the task associated with the model
ModelName
String*50
Name of the model (informational purposes)
ModelDesc
String*50
Description of the model (informational
purposes)
SysDynModel
String*50
Filename of the actual system dynamics
model
Start
Long
Start time to play model
Stop
Long
Stop time to play model
Step
Long
Interval at which to play ne model step and
record data
[0120] This information is stored in the model table of the simulation database (ICASim.mdb). All of the values that will need to be manually entered by the student that are passed into the system dynamics model are configured as parameter inputs (PInputs) objects. Every PInput has an interface as detailed below.
[0000]
Field Name
Data Type
Description
PinputID
long
Primary Key for the table
TaskID
long
TaskID of the task associated with the
parameter input
ModelID
long
ID of the model associated with the
parameter input
InputName
string*50
Name of the parameter input
(informational purposes)
InputDesc
string*255
Description (informational purposes)
ReferenceName
string*50
Name of the spreadsheet cell associated
with the parameter input
SimReferenceName
string*50
Name of the associated parameter in
the system dynamics model
TutorAware
boolean
Whether the ICA should be notified of
any input CHANGES
SourceItemID
long
SourceItemID of the parameter input
TargetID
long
TargetID of the parameter input
Row
long
Spreadsheet row number of the
parameter input
Column
long
Spreadsheet column number of the
parameter input
SheetName
string*50
Sheet name were the parameter input is
located
[0121] All of this information is stored for every parameter input in the PInput table of the simulation database (ICASim.mdb). PInputs consist of one spreadsheet cell that can be populated by a designer at design time or by the GBS application at run time via the system dynamics engine object's methods. The purpose of the cell is to provide an entry point to the simulation and system dynamics models. An example of an entry point would be the interest rate parameter in the interest calculation example. The ICA is notified of any changes to the cell when an appropriate activity transpires. When the ICA is notified of a change two messages are sent to the ICA. The first is an ICANotifyDestroy message with the parameter input information i.e., SourceItemID, TargetID and null as an attribute. This message is sent to inform the ICA to remove information from its memory. The second message is an ICANotifyCreate message with the parameter input information i.e., SourceItemID, TargetID, Attribute (cell numeric value). This message advises the ICA to add this information to its memory. A PInput table record in accordance with a preferred embodiment is presented below.
[0000]
PInputID:
12345
TaskID:
123
ModelID:
1
InputName:
Interest Rate input
InputDesc:
Interest Rate input into interest
calculation model
ReferenceName:
Interest_Rate
SimReferenceName
Param_Interest_Rate
TutorAware:
True
SourceItemID
\1201
TargetID
4001
Row:
6
Column:
3
SheetName:
Sheet1
[0122] Once the configuration is completed, the designer can also use the ICA Utilities to test the simulation. The Row, Column and SheetName values are automatically populated when the designer runs the parameters in the System Dynamics Workbench in the ICA Utilities. The following information provides details describing the interaction components in accordance with a preferred embodiment.
[0000]
Title
Description
Procedural tasks (w/drag drop)
Tasks which require the construction of some kind of
report with evidence dragged and dropped to justify
conclusions
Procedural tasks (w/o drag drop)
New task designs that are procedural in nature, have very
little branching, and always have a correct answer
Ding Dong task
Tasks that interrupt the student while working on
something else. This template includes interviewing to
determine the problem, and a simple checkbox form to
decide how to respond to the situation.
Analyze and Decide (ANDIE) task
Most commonly use for static root cause analysis or
identification tasks. Developed on SBPC as a result of 3
projects of experience redesigning for the same skill.
Evaluate Options (ADVISE)
Used for tasks that require learner to evaluate how
different options meet stated goals or requirements.
Developed at SBPC after 4 projects experience
redesigning for the same skill. Does not allow drag drop
as evidence.
Run a company task
Time based simulation where student “chooses own
adventure.” Each period the student selects from a
pre-determined list of actions to take. Developed on
SBPC as a simplified version of the BDM manage task.
Use a model task
When user needs to interact with a quantitative model to
perform what if analysis. May be used for dynamic root
cause analysis-running tests on a part to analyze stress
points.
ICA Dynamic Meeting Task
Developed on BDM to mimic interaction style from
Coach and ILS EPA. Supports dynamic-rule based
branching-will scale to support interactions like EnCORE
defense meetings and YES.
Manage Task
Time based simulation where student manages resources.
Human Resources Management, managing a budget,
manage an FX portfolio.
QVID Static Meeting Task
Developed on Sim2 to support agenda-driven meetings
where user is presented with up to 5 levels of follow-up
questions to pursue a line of questioning. As they ask each
question, its follow-ups appear.
Flow Chart Task
Will support most VISIO diagrams. Developed on Sim2
to support simple flow chart decision models.
QVID Gather Data Component
Static flat list of questions to ask when interviewing
someone. Not used when interviewing skills are being
taught (use QVID Static meeting task). Supports
hierarchical questions and timed transcripts.
Journalize Task
Created to support simple journal entry tasks with up to 2
accounts per debit or credit.
New Complex Task
A new task that requires a simulation component.
[0123] The system dynamics engine is of interest to the designer so that she can understand the mechanics of it. Once the designer has constructed the simulation model (Excel Spreadsheet), built the system dynamics model (PowerSim) and configured all of the parameter inputs and parameter outputs, a test can be performed using the workbench included in the ICA Utilities (refer to ICA Utilities documentation). The developers, in turn, need to implement the calls to the system dynamics engine in the GBS application that is being built. The following list identifies the files that need to be included in the Visual Basic project to use the system dynamics engine.
[0000]
wSysDynEng.cls
System dynamics Engine class
wSysDynEng.bas
System dynamics Engine module (this module was
introduced only for speed purposes because all the
code should theoretically be encapsulated in the class)
wConst.bas
Intelligent Coaching Agent constant declaration
wDeclare.bas
Intelligent Coaching Agent DLL interface
wIca.cls
Intelligent Coaching Agent class
wIca.bas
Intelligent Coaching Agent module (this module
was introduced only forspeed purposes because
all the code should theoretically be encapsulated in
the class)
[0124] To utilize the system dynamics engine fully, the developer must place code in different strategic areas or stages of the application. Initial stage—the loading of the form containing the simulation front-end. This is when the simulation model and system dynamic engine are initialized. Modification stage—Takes place when the user makes changes to the front-end that impacts the simulation model PInputs). This is when the ICA is notified of what's happening. Run stage—The system dynamics model is run and parameter outputs are received. Feedback stage—The user requests feedback on the work that they have performed. This is when the simulation notifies the ICA of all output changes. Final stage—The simulation front-end unloads. This is when the simulation model is saved. These stages will be explained by including the Visual Basic code involved as well as a short description of that code.
[0125] 1. Creating the ICA & the simulation engine objects: Code: Set moSysDynEngine=New classSysDynEngine; Set moICA=New classICA; Description: The first step in using the system dynamics engine is to create an instance of the classSysDynEngine class and also an instance of the classICA class. Note that the engine and ICA should be module level object “mo” variables. 2. Loading the simulation: Code: IRet=moSysDynEngine. OpenSimulation (FILE_SIM, Me.bookSim, True); IRet=moSysDynEngine.LoadSysDyn(mIICATaskID, DB SIMULATION, 1); IRet=moSysDynEngine.LoadModel(MODEL_NAME,mbTaskStarted); Description: After the object creation, the OpenSimulation, LoadSimulation and LoadModel methods of the system dynamics engine object must be called. The OpenSimulation method reads the specified Excel 5.0 spreadsheet file (FILE_SIM) into a spreadsheet control (bookSim). The LoadSysDyn method opens the simulation database (DB_SIMULATION) and loads into memory a list of parameter inputs and a list of parameter outputs. The LoadModel method opens a system dynamics model (MODEL_NAME). Every method of the system dynamics engine will return 0 if it completes successfully otherwise an appropriate error number is returned. 3. Initializing and loading the Intelligent Coaching Agent; Code: IRet=moICA. Initialize (App.Path & “\” & App.EXEName & “.ini”, App.Path & DIR_DATABASE, App.Path & DIR_ICADOC, App.Path & “\”); IRet=moICA. LoadTask(mIICATaskID, ICAStudentStartNew); Description: The system dynamics engine only works in conjunction with the ICA. The Initialize method of the ICA object reads the application .ini file and sets the Tutor32. dII appropriately. The LoadTask method tells the ICA (Tutor32.dII) to load the .tut document associated to a specific task in memory. From that point on, the ICA can receive notifications. Note: The .tut document contains all the element and feedback structure of a task. Ex: SourcePages, SourceItems, TargetPages, Targets, etc. . . . 4. Restoring the simulation-Code: IRet=moSysDynEngine.RunPInputs (MODEL_NAME, True); IRet=moSysDynEngine.RunPOutputs (MODEL_NAME, True); IRet=moSysDyn Engine.PassPInputsAll; Call moICA.Submit (0); Call moICA.SetDirtyFlag(0, False) Description: Restoring the simulation involves many things: clearing all of the parameter inputs and outputs when the user is starting over; loading the interface with data from the simulation model; invoking the PassPInputsAll method of the system dynamics engine object in order to bring the ICA to its original state; invoking the RunPInputs and RunPOutputs methods of the system dynamics engine object in order to bring the system dynamics model to it's original state; calling the Submit method of the ICA object to trigger the ICA to play all of the rules; calling the SetDirtyFlag of the ICA object to reset the user's session. Running parameters involves going through the list of TutorAware PInputs and POutputs and notifying the ICA of the SourceItemID, TargetID and Attribute value of every one. Modification Stage; 1. Reading parameter inputs & outputs; Code: Dim sDataArray(2) as string; Dim vAttribute as variant; Dim ISourceItemID as long, ITargetID as long; IRet=moSysDynEngine.ReadReference (“input_Name”, vAttribute, ISourceItemID, ITargetID, sDataArray). Description: The ReadReference method of the system dynamics object will return the attribute value of the parameter input or output referenced by name and optionally retrieve the SourceItemID, TargetID and related data. In the current example, the attribute value, the SourceitemID, the TargetID and 3 data cells will be retrieved for the parameter input named Input Name. 2. Modifying parameter inputs Code: Dim vAttribute as variant; Dim ISourceItemID as long; Dim sDataArray (2) as string; vAttribute=9999; sDataArray (0)=“Data Cell #1”; sDataArray(1)=“Data Cell #2”; sDataArray(2)=“Data Cell #3”; IRet=moSysDynEngine. WriteReference (“Input_Name”, vAttribute, sDataArray). Description: To modify a parameter input, call the WriteReference method of the system dynamics object and pass the PInput reference name, the new attribute value and optionally a data array (an additional information to store in the simulation model). The system dynamics engine notifies the ICA of the change. Run Stage 1. Playing the System Dynamics Model; Code: IRet=moSysDynEngine. PlayModel (SYSDYN_PLAYSTEP); IbICurrentTime. Caption moSysDynEngine.CurrentTime; and IbILastTime.Caption=moSysDynEngine.LastTime; Description: Playing the system dynamics model is also handled by the system dynamics engine. There are three ways that the models can be played, all at once, one step at a time (shown above) or until a specific point in time. These are the parameters that are passed into the PlayModel method. Playing of the model generates the parameter output values and passes the Tutor Aware POutputs to the ICAT. The engine also keeps track of time and these values can be read using the CurrentTime and LastTime properties. 2. Jumping Back in a System Dynamics Model Code: IRet=moICA.LoadTask (mIICATaskID, ICAStudentStartNew); IRet=moSysDynEngine.JumpBack(TIME_TO_JUMP_TO). Description: Because the system dynamics engine writes backup copies of the parameters passed to and from it, it can start over and resubmit these values back to the system dynamics model until a given period of time. To do this, the code would need to restart the ICA and then call the system dynamics engine to jump back to a given time (TIME_TO_JUMP_TO). Feedback stage 1. Triggering the ICA Rule engine; Code: IRet=moICA.Submit(ICoachID); Description: Once the simulation has been processed, the Submit method of the ICA object must be called to trigger all the rules and deliver the feedback. This feedback will be written by the Tutor32.dII to two RTF formatted files. One file for previous feedback and one file for the current feedback.
ICA CONFIGURATION IN ACCORDANCE WITH A PREFERRED EMBODIMENT
[0126] FIG. 28 is an overview diagram of the logic utilized for initial configuration in accordance with a preferred embodiment. Since the structure of the feedback is the same as other on-line activities, the ICA can also be configured in the same manner. For ease of creation and maintenance of ICA feedback, it is recommended that the feedback is constructed so that only one rule fires at any point in time. Note that the organization of the example is one of many ways to structure the feedback. Step 1: Create a map of questions and follow-up questions; Before designers start configuring the ICA, they should draw a map of the questions, videos and follow-up questions that they wish to use in the on-line meeting. This will give them a good understanding of the interactions as they configure the ICA. Step 2: Create a coach; All feedback is given by a coach. Create a specific coach for the on-line meeting. Step 3: Create the Source Items and Targets
[0127] Every question will have one Source Item (1) and Target (2) associated with it. These will be used by the ICA to show videos and follow-up questions. For organizational purposes and ease of reading, it is recommended that each Source Page (“0 Intro”) contain all of the follow up questions (“Intro Q1”, “Intro Q2”, “Intro Q3”). Targets can be created one per Source Item (shown here) or one per many Source Items. This is not very important, so long as there are distinct Source Item and Target associations. Once the Source items and Targets have been created, associate them into SourceItemTargets (3) and give them a relevance of one. These are the unique identifiers which the ICA will use to fire rules and to provide feedback to the student. Step 4: Create the Parent Header (Video Information) FIG. 29 is a display of video information in accordance with a preferred embodiment. Feedback (Coach Items) are organized into Target Groups (1). In FIG. 29 , each on-line question has one Target Group for ease of maintenance. Each TargetGroup must have at least one related Target (4). These are the SourceItemTarget mappings that were made at the end of Step 3. Next, Rules (2) are created to fire when the SourceItemTarget is mapped (a question is clicked). Coach Items (3) are associated to a rule and represent the feedback which will be shown if the rule is fired. The ICA Utilities incorporate business simulation into a multimedia application. What this means is that there is now a middle layer between the application and the ICAT. These utilities, along with the simulation engine (described later), allow the architecture to be a front end to the simulation. Now, any changes to a simulation model do not need to be incorporated into code. The ICA Utilities and simulation engine work with simulation models created in Microsoft Excel. After the model is created, the designer uses the Defined Name function in Excel to flag specific cells that are to be used by the application and the ICA Utilities in accordance with a preferred embodiment. FIG. 30 illustrates an ICA utility in accordance with a preferred embodiment. The ICA Utilities consist of six utilities that work with the Intelligent Coaching Agent Tool (ICAT) to incorporate business simulation with the multimedia application. | A system is disclosed that provides a goal based learning system utilizing a rule based expert training system to provide a cognitive educational experience. The system provides the user with a simulated environment that presents a business opportunity to understand and solve optimally. Mistakes are noted and remedial educational material presented dynamically to build the necessary skills that a user requires for success in the business endeavor. The system utilizes an artificial intelligence engine driving individualized and dynamic feedback with synchronized video and graphics used to simulate real-world environment and interactions. A robust business model provides support for realistic activities and allows a user to experience real world consequences for their actions and decisions and entails realtime decision-making and synthesis of the educational material. The system is architectured around a table of components to manage and control the system. | 8 |
This application is a continuation of application Ser. No. 09/795,054, filed Feb. 26, 2001, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to a wrapper for a smoking article to create a reduced ignition propensity (IP) smoking article and, more particularly, to a smoking article having the ability to freeburn in a static state and reduced IP. Under some circumstances cigarettes may ignite fire-prone substrates if the article is laid or accidentally contacts the substrate. Therefore, a cigarette prepared from a wrapper, which diminishes the ability of the article to ignite a substrate, may have the desirable effect of reducing cigarette-initiated fires. Furthermore, a wrapper that concurrently confers on the cigarette the ability to freeburn in a static state and reduced IP character allows a beneficial reduction in the tendency of the article to ignite fire-prone substrates while maintaining consumer acceptability.
There have been various attempts to create a cigarette that has reduced IP and consumer acceptable attributes particularly taste and the ability to freeburn in the static state. Technologies that appear to provide such cigarettes are described in the patent literature. Cigarettes claiming to possess reduced IP are commercially available.
A factor that manufacturers consider in preparing a smoking article having reduced IP is whether currently used processes and equipment will remain substantially unchanged. One method for preparing a reduced IP paper involves the addition of elaborate equipment on a conventional papermaking machine. Cellulose fibers or particles suspended in water are sprayed from angular moving nozzles moving at an angle to a continuous forming moist web. This approach involves the coordinated angular movement of the spray nozzle and the about 400 feet per minute moving web to create spaced apart bands transverse to the web. The above-mentioned technology suffers from a number of deficiencies that limit consumer acceptability, IP reduction, and ease of manufacture. The technology requires expensive add-on equipment including a spray nozzle system and an associated slurry distribution system, pressure regulating system, and a means for carefully synchronizing the angular material distribution system with the underlying papermaking machine.
The reduced consumer acceptable properties of the prepared cigarettes are due to factors including reduced ability of the cigarette to freeburn in the static state, poor ash appearance, and variable taste profile.
The poor IP reduction performance achieved by cigarettes prepared with wrappers made using this technology is believed to be caused by a number of factors including difficulty in depositing an even layer of the cellulose fibers or particles, low efficiency of the cellulose fibers or particles to reduce the permeability of the underlying web, and poor reproducibility caused by fanning out of the sprayed material. Deficiencies in the approach that limit ease of manufacture include the difficulty in synchronizing the angular moving cellulose fibers and particles distribution apparatus with the underlying web forming apparatus and difficulty in reducing the banded moist web to dryness without disrupting the structure of the web.
Another technology involves adding discrete material regions to the dry web using organic solvent-based printing equipment. Organic solvents and non-aqueous soluble solutes are used to make the discrete regions on the web. The presence of organic solvents requires hoods to capture the solvent vapors and the corresponding further expenses.
In regard to commercially available cigarettes claiming to possess reduced IP, consumers may find their organoleptic experience wanting. Some technologies that are based on discretely treated areas for reduced IP cigarettes create a varying organoleptic experience as the consumption of the smoking article moves from treated area to non-treated areas.
One commercial product claiming to possess reduced IP is characterized by a tendency to extinguish when left burning in the static state—that is reduced freeburn. The article displays a less desirable taste when relit after being extinguished. Thus, although the cigarette may possess the reduced IP, the reduced freeburn property decreases consumer acceptability of the article.
Other factors affecting consumer acceptability are product appearance, including pleasing and consistent wrapper and ash character. Moreover, it is important that the construction of the smoking article exhibit a reasonable shelf-life while maintaining reduced IP.
Thus, there remains a need for a new and improved wrapper and smoking article having reduced IP while at the same time possessing a sufficient free burn. Also, there remains a need for a new and improved method for making a wrapper that can be used to create a smoking article having reduced IP and sufficient freeburn.
SUMMARY OF THE INVENTION
The present invention is directed to a smoking article having reduced IP. The smoking article includes a tobacco column, a wrapper surrounding the tobacco column and, optionally, a filter element. The wrapper has a base permeability, an untreated area and a least one discrete area treated with a composition to reduce the base permeability. The discretely treated area interacts with a coal of a burning tobacco firecone as it advances to self-extinguish the smoking article if the smoking article is left on a surface or causes the cigarette not to ignite the surface.
The tendency of a cigarette to self-extinguish or not ignite surfaces can be measured by the use of IP tests such as those published by the Consumer Products Safety Commission and developed by the National Institute of Standards and Technology (NIST) or the American Society of Testing and Materials (ASTM). See Ohlemiller, T. J. et al., “Test Methods for Quantifying the Propensity of Cigarettes to Ignite Soft Furnishings. Volume 2, “NIST SP 851; volume 2; 166 pages [also includes: Cigarette Extinction Test Method, see pp. 153-160] August 1993 available from U.S. Consumer Product Safety Commission, Washington, D.C. 20207 as order number PB94-108644, the subject matter of which is herein incorporated by reference. One NIST IP test, the “cotton duck test”, involves placing a smoldering cigarette on a test assembly composed of a cellulosic fabric over a foam block. Variations of the test use fabrics of various weights and polyethylene sheet backing. A test failure occurs when the fabric ignites. Another NIST IP test, the “filter paper test”, involves placing a smoldering cigarette on a test assembly composed of layered filter paper sheets. Various forms of the test use 3, 10, and 15 layered filter paper sheets. A successful test result occurs when the cigarette self extinguishes before the whole tobacco column is consumed.
The composition of the treated area includes at least a permeability reducing substance. Another substance in the treated area includes a burn rate retarding substance. Yet another substance in the treated area includes a burn rate accelerating substance. Either the burn rate retarding substance or the burn rate accelerating substance or both preferably acts as an organoleptic enhancing substance. In this way a smoker's experience when smoking either the at least one treated area or the untreated area is substantially the same. Additionally, the composition of the treated area may include a filler component.
In a wrapper making process, the applied amount of the permeability reducing substance, the burn rate retarding substance, and the burn rate accelerating substance is such as to give the desired freeburn character and IP reduction to a finished article made from the wrapper. The quantity and the concentration of the applied composition will depend on factors including the absorbency of the web, polymer properties of the permeability reducing substance, whether the web is wet or dry, and the operating conditions of the application equipment.
The burn rate accelerating substance may be an alkali metal or alkaline-earth containing salt. Preferably, the bum rate accelerating substance may be an alkali metal salt of a carboxylic acid such as acetic acid, citric acid, malic acid, lactic acid, tartaric acid and the like. Preferably, the salt of the carboxylic acid is a salt of citric acid. Also, the alkali metal containing compound is preferably at least one of a sodium containing compound and a potassium containing compound. Alternatively, the burn rate accelerating substance may be monoammonium phosphate.
The burn rate retarding substance may be a phosphate, preferably a phosphate of ammonium and more preferably a diammonium phosphate.
The permeability reducing substance may be a pore filling substance, a film forming substance or combination thereof. The permeability reducing substance may be a polymer and, preferably, a polysaccharide. Among the contemplated polysaccharides are starch, including various mixtures of amylose, amylopectin and dextrin, modified starch and starch derivatives. The starch and starch derivatives may be water dispersible and, preferably, water soluble. Other contemplated polysaccharides include cellulose, cellulose derivatives, chitosan, chitosan derivatives, chitin, chitin derivatives, alginate, alginate derivatives and combinations thereof. These polysaccharides are preferably water dispersible and, more preferably, are water-soluble.
In one embodiment, the discretely treated area is a circumferential band about the body of the article. The band has a sufficient width so as to deprive the coal of the burning tobacco firecone of oxygen from behind a char line of the wrapper when the smoking article is placed on a surface. That may be achieved by a band width typically of at least about 3 millimeters.
In an alternative embodiment, the discretely treated area includes at least two bands spaced sufficiently to reduce the IP of the smoking article. In this case, the two bands preferably have a center-to-center spacing of between about 10 millimeters to about 30 millimeters. The two bands may have a width of about 3 millimeters to about 10 millimeters. A center-to-center spacing is preferably about 25 millimeters.
The discretely treated area preferably has a thickness and properties so a bobbin of the wrapper is useable in a commercially available smoking article manufacturing machine. Also, the discretely treated area is preferably visually substantially the same as the untreated area.
Still another aspect of the present invention is to provide a population of smoking articles having a reduced IP. Each smoking article within the population includes a tobacco column, wrapper surrounding the tobacco column so that the smoking article includes an ignition end and a distal end, and at least one banded region, preferably at least two spaced apart banded regions, between the ignition end and the distal end having a combustion characteristic substantially different from that of an non-banded, untreated, region. A distance from the ignition end to the at least one of the banded region of each smoking article may be sequentially related, random, or quasi-random within a selected population.
In one embodiment, the selected population is a package of smoking articles and in another embodiment a grab sample of smoking articles.
In another embodiment, the distance from the ignition end to the at least one of the banded regions of each smoking article are sequentially related, random, or quasi-random.
In a preferred embodiment, the IP of the selected population is between about 50 and about 100 percent for the population.
The invention also provides a method of making a wrapper, of making a smoking article having reduced IP, and a composition for application to a paper to make a wrapper and a smoking article.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood after a reading of the following description of the preferred embodiment when considered with the drawings in which:
FIG. 1 is a perspective view of a smoking article according an embodiment of the present invention;
FIG. 2 is an exploded view of the smoking article of FIG. 1 ;
FIG. 3 is a perspective view of a bobbin of wrapper that may be used to make the smoking article of FIG. 1 ;
FIG. 4 is a plan view of a wrapper as might be accumulated in a bobbin as shown in FIG. 3 ;
FIG. 5A is a schematic of a population of smoking articles having a substantially random distance from the ignition end to the at least one of the banded region of each smoking article within the population according an embodiment of the present invention;
FIG. 5B is a schematic of a population of smoking articles having a quasi random distance from the ignition end to the at least one of the banded region of each smoking article within the population according an embodiment of the present invention;
FIG. 5C is a schematic of a population of smoking articles having a sequentially related distance from the ignition end to the at least one of the banded region of each smoking article within the population according an embodiment of the present invention; and
FIG. 6 is a schematic of a package of smoking articles of any of FIG. 1 , FIG. 5A , FIG. 5 B and FIG. 5 C.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings in general and FIG. 1 in particular, it will be understood that the illustrations are for the purpose of describing a preferred embodiment of the invention and are not intended to limit the invention thereto. As best seen in FIG. 1 , a smoking article 10 includes a tobacco column 12 surrounded by a wrapper 14 . The smoking article 10 may, as an option, include a filter element 16 adjacent to the tobacco column 12 surrounded by the wrapper 14 .
FIG. 2 shows an exploded view of the smoking article 10 of FIG. 1 including certain aspects relating to the wrapper 14 , which is a modified cigarette paper. In particular, wrapper 14 includes untreated areas 20 alternating with treated areas 22 . Treated areas 22 include a combination of substances that interact with the wrapper 14 to create the reduced IP smoking article 10 . At least one of the substances in treated area 22 includes a permeability reducing substance. Another substance in treated area 22 includes a burn rate retarding substance. Yet another substance in treated area 22 includes a burn rate accelerating substance. Optionally, another substance in the treated area includes filler. These substances interact with each other and the wrapper paper 14 to create a wrapper that may be used to manufacture reduced IP smoking article 10 .
The permeability reducing substance may be a polymer. The polymer may be any one of a natural polymer, a derivative of a natural polymer, a synthetic polymer, and a combination of any of the preceding. Applicants have found that polysaccharides are suitable as permeability reducing substances. The polysaccharides may be at least one of a starch, modified starch, starch derivative, cellulose, cellulose derivative, chitosan, chitosan derivative, chitin, chitin derivative, alginate, alginate derivative or a combination of any of the preceding. Any polysaccharide that suitably reduces the permeability of the wrapper would be appropriate for use as the permeability reducing substance.
Applicants believe that starch, modified starch, starch derivatives, cellulose and cellulose derivatives would act particularly well as permeability reducing substances. Applicants have found that starch and starch derivatives work particularly well as the permeability reducing substance. Water soluble and water dispersible starch, starch derivatives, cellulose and cellulose derivatives would be more desirable than nonaqueous solvents and dispersants. Nonaqueous solvents may be harmful to workers, or environmentally regulated so that exhaust equipment that may be needed to capture organic solvent mists and vapors.
Without wishing to be bound by any scientific theory and explanation, applicants believe that a permeability reducing substance may interact with the wrapper in a number of ways. In one, a permeability reducing substance may form a film on the wrapper 14 to reduce permeability by blocking pores in the wrapper 14 . That is, when the permeability reducing substance is applied to the wrapper 14 , a film is created that acts as a barrier to block the movement of gas through pores in the discretely treated area 22 .
Alternatively, a permeability reducing substance may act to fill pores and thereby reduce the porosity of the wrapper 14 . In this way, a discretely treated area 22 possesses porosity or gas permeability less than that of the untreated area 20 of the wrapper 14 .
As a further alternative, a permeability reducing substance may both form a film on the wrapper 14 and act to fill pores in the wrapper 14 so that a discretely treated area 22 possesses a porosity or gas permeability less than that of the untreated area 20 of the wrapper 14 .
Applicants have determined that the permeability in the discretely treated area 22 of wrapper 14 may be less than about 10 CU (CORESTA units, cm 3 /min/cm 2 at 1 kPa measuring pressure as substantially measured according to CORESTA [Cooperative Centre for Scientific Research Relative to Tobacco, Paris, France] Recommended Method No. 40: Determination of Air Permeability of Materials Used as Cigarette Paper, Filter Plug Wrap and Filter Joining Paper including Materials Having an Oriented Permeable Zone, October 1994, published in Bulletin 1994-3/4, the subject matter of which is incorporated herein by reference) and is preferably less than about 7 CU. Alternatively, the band area, and optionally untreated area, may contain a perforation zone produced by methods such as electrostatic and mechanical perforation and the like that are known to those skilled in the art. Applicants have discovered the unexpected property that a banded area, possessing a perforation zone, may exhibit a relatively high apparent permeability while still conferring a reduced IP character on an article made from the thus treated paper. In a preferred embodiment the permeability of a perforated band may be less than about 60 CU.
A burn rate retarding substance includes any substance that reduces the smolder rate of materials such as paper, cloth and plastic, and may also increase their resistance to flaming combustion. Phosphates have been found to work well and, in particular, phosphates of ammonium. A particular preferred phosphate of ammonium is the diammonium phosphate (having synonyms such as diammonium hydrogenphosphate; DAP; diammonium hydrogenorthophosphate; phosphoric acid, diammonium salt; and ammonium hydrogen phosphate).
A burn rate retarding substance may have additional beneficial benefits including unexpected improved organoleptic properties discovered by applicants. To that end, applicants have found that consumers detect a more pleasing smoke taste when the burn rate retarding substance is present in the discretely treated area 22 in smoking article 10 according to the present invention.
A burn rate retarding substance also may cooperate with a permeability reducing substance in another unexpected synergistic manner. That is, the inclusion of a burn rate retarding substance may reduce the amount of a permeability reducing substance that may need to be applied to a discretely treated area 22 . This may have an impact on the manufacturability of a wrapper 14 according to the present invention by decreasing the amount of permeability reducing material needed to achieve IP reduction.
A burn rate accelerating substance includes any substance known to increase the rate at which the smolder process of such materials as paper, cloth and plastic takes place. Such a substance may contribute to the free burn of a smoking article 10 according to the present invention. Preferably, a reduced IP smoking article 10 self-extinguishes when placed onto a surface and continues to burn when the smoking article 10 is freely suspended such as within the holder of an ashtray or held without puffing. This latter attribute is known as “freeburn.” To that end, a burn rate accelerating substance interacts with the wrapper 14 , the permeability reducing substance, and the burn rate retarding substance to create a discretely treated area 22 that works to maintain the balance between self-extinguishment and freeburn.
A burn rate accelerating substance may be a salt such as an alkali metal and an alkaline-earth metal containing salt and, preferably, one containing an alkali metal preferably sodium, potassium and sodium and potassium. The salt may be a salt of a carboxylic acid such as acetic acid, citric acid, malic acid, lactic acid, tartaric acid and the like. In a particularly preferred embodiment, it is a salt of a citric acid. Alternatively, the burn rate accelerating substance may be monoammonium phosphate.
A burn rate accelerating substance may have additional beneficial benefits including unexpected organoleptic enhancing abilities discovered by applicants. To that end, applicants have found that consumers detect substantially no difference between smoking an untreated area 20 and a discretely treated area 22 in smoking article 10 according to the present invention. This removes the need for difficult to achieve gradations, such as described in U.S. Pat. No. 5,878,753, between a discretely treated area 22 and untreated areas 20 to maintain a substantially consistent organoleptic experience for the consumer.
A filler substance includes particulate materials such clay, chalk (calcium carbonate), and titanium oxide. Applicants believe that the presence of filler may be beneficial during the manufacture of discretely treated areas 22 by allowing the appearance, particularly the opacity, of discretely treated areas 22 to be carefully controlled so as to be substantially the same as the untreated region 20 .
A manufacturing of discretely treated areas 22 may be made by applying compositions that are applicable to the wrapper 14 when the wrapper 14 might be in a wet or dry state or a semi-wet state. Those skilled in the art will appreciate that the quantity and the concentration of the applied composition will depend on factors including the absorbency of the web, properties of the permeability reducing substance, whether the web is wet or dry, and the operating conditions of the application equipment. Moreover, those skilled in the art will appreciate that the composition may be applied by a number of known methods including spraying, stenciling, flexographic printing, gravure printing, and the like including both multiple-pass and single-pass processes.
Preferably, the composition for affecting the discretely treated areas may be applied on one side of the base paper such that the formed band 22 faces the tobacco-side 12 after making article 10 from the banded paper. Alternatively, the composition may be applied on both sides of the paper or applied such that the formed band 22 faces the outside or consumer-side after making article 10 from the banded paper.
Manufacturing of reduced IP smoking articles is preferably accomplished using a reel, or bobbin, length of wrapper 14 with discretely treated areas 22 and untreated areas 20 . Using a bobbin of banded paper in a cigarette-making machine will provide a population of banded smoking articles having a reduced IP. That is, each smoking article within the population will include a tobacco column, wrapper surrounding said tobacco column so that the smoking article includes an ignition end and a distal end, and at least one banded region, preferably at least two spaced apart banded regions, between the ignition end and the distal end whereby the distance from the ignition end to the at least one of the banded region of each smoking article may be random (substantially as depicted in FIG. 5 A), quasi-random (substantially as depicted in FIG. 5 B), or sequentially related (substantially as depicted in FIG. 5C ) within the population. The population may any population such as a grab sample and a package of cigarettes as depicted in FIG. 6 .
Applicants believe that the sequentially related, random, or quasi-random band position would have the benefit of allowing the cigarette population as a whole to have fewer tendencies to ignite fire-prone substrates. Overall, IP tests incorporate a fixed burn-down distance in which the article is burned before being placed on the test substrate. In real-world ignition scenarios the article may burn down to any distance with respect to the ignition end of the article before contacting a substrate. Therefore, a sequentially related, random, or quasi-random band position will increase the probability that any individual member of the banded article population may prevent ignition of a prone substrate when the article is burned down to a random distance before substrate contact. Alternatively, bands may be registered at a fixed distance with respect to the ignition end of article 10 . The preferred embodiment of this invention is for the manufacture of reduced IP articles having a sequentially related, random, or quasi-random band position with respect to the ignition end of article 10 .
The following examples relate to smoking articles produced according to the present invention and are provided to more fully explain the invention. In the examples describing sample cigarette papers made by “gravure printing” the samples were made using a single-pass gravure printing process. Bands on the gravure-printed paper were about 6 mm wide, substantially perpendicular to the paper edge, and applied at about 25 mm intervals center to center. After printing and allowing the applied composition to dry, the treated paper was slit and rolled into bobbin form compatible with a standard cigarette-making machine. The banding composition was printed on one side of the base paper such that band 22 was facing the tobacco-side 12 after making article 10 from the banded paper. Gravure print-banded paper was used to manufacture cigarette using a conventional cigarette-making machine thereby giving a selected population of cigarettes with quasi-random band positions.
In the examples describing sample cigarettes prepared by “hand banding” a circumferential ring of material was applied around the body of smoking article, by hand, using an aluminum printing plate. The aluminum printing plate was fashioned from a slab of aluminum metal with a straight channel, about 7 millimeters wide and about 30 millimeters long, milled below the surface of the slab. A banding composition was used to fill the channel of the printing plate. The smoking article was then rolled, by hand, across the composition-filled channel such that a circumferential band was formed about the body of the smoking article. Therefore, the about 7 millimeter wide band was printed on one side of the wrapper such that band 22 was on the outside or consumer-side of article 10 . Hand banded cigarettes are characterized as having the applied band registered at a fixed position with respect to the ignition end of the article.
In each of the examples, “freeburn” was measured by igniting a cigarette and placing the smoldering article horizontally in a holder. The article was allowed to statically smolder without the column or ember contacting a surface. A positive freeburn result occurred when the cigarette was consumed to the filter element.
In each of the examples, a series of conventional flax pulp cigarette papers were used and the properties of these papers are given in Table 1.
TABLE 1
Average Base Paper Properties.
Basis Weight
Paper
Permeability (CU)
Filler (%)*
Citrate (%)**
(g/m 2 )
A
18
30
0.85
25.5
B
29
29
0.85
25.5
D
31
28
2.30
26.0
E
32
28
0.60
26.0
F
37
30
0.90
26.0
G
48
28
0.93
25.5
H
71
32
0.70
25.8
*Weight percent calcium carbonate
**Weight percent citrate salt
EXAMPLE 1
Three smoking article types were made using a paper wrapper, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend. The cigarettes were made on a conventional cigarette-making machine. Two of the smoking article samples were made using separately banded, reduced IP papers. The third smoking article sample served as a control and was made from a standard cigarette paper. For all smoking article samples in this example paper A was used.
Two banded wrappers were made by applying permeability reducing compositions on base paper A using gravure printing. About 60,000 cigarettes were made for each of a high band weight wrapper type, designated 1-C, a low band weight wrapper type, designated 1-B, and a conventional non-banded wrapper, designated 1-A, as a control. All cigarette types were tested for IP according to the NIST (10-sheet) filter paper IP test and freeburn.
Cigarette type 1-B was made from cigarette paper A gravure printed with a composition containing about 20.5 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 0.90 weight percent DAP (Rhodia, Cranbury, N.J.), about 8.40 weight percent citrate salt, and bout 70.17 weight percent tap water. The citrate salt was a mixture of sodium citrate dihydrate (Fisher Scientific, Fair Lawn, N.J.) and potassium citrate monohydrate (Fisher Scientific, Fair Lawn, N.J.) in an about 1:2.8 weight/weight ratio. The composition was heated at approximately 87° C. for about 15 minutes. The permeability in the banded region was measured as about 6 CU.
Cigarette type 1-C was made from cigarette paper A gravure printed with a composition containing about 27.21 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 1.20 weight percent DAP (Rhodia, Cranbury, N.J.), about 11.13 weight percent citrate salt, and about 60.46 weight percent tap water. The citrate salt was a mixture of sodium citrate dihydrate (Fisher Scientific, Fair Lawn, N.J.) and potassium citrate monohydrate (Fisher Scientific, Fair Lawn, N.J.) in an about 1:2.8 weight/weight ratio. The composition heated at approximately 87° C. for about 15 minutes. The permeability in the banded region was measured as about 4 CU.
During cigarette production, approximately 100 cigarettes were collected after about multiples of about 6,000 cigarettes were produced. The banded, reduced IP, papers ran substantially the same as the non-banded standard cigarette paper. No manufacturing or packing problems were observed.
Table 2 indicates IP and freeburn results for the control cigarette. The results in Table 3 and Table 4 indicate that the reduced IP prototypes cigarettes were characterized as having significant IP reduction, relative to the control, while maintaining the ability to freeburn in the static state.
Applicants observed that the manufacturing of cigarettes 1-B and 1-C gave a population of banded cigarettes. The band position of grab samples, collected on the cigarette-making machine immediately after manufacture, were believed to have sequentially related band positions. Overall, the band position relationship between the grab samples and the population as a whole was believed to be quasi-random. The results in Tables 2 and 3 show that the freeburn and IP reduction for the grab samples was similar to the population average.
The smoke taste profile of cigarettes 1-B and 1-C were substantially the same as control cigarette 1-A in terms of taste when smoking within banded areas and smoking in the untreated, non-banded, areas. The bands on 1-B and 1-C cigarettes were found to be nearly undetectable compared to the non-banded control article 1-A. For the reduced IP articles, 1-B and 1-C, the appearance of the ash after the banded region was smoked through was substantially the same as the ash formed when the untreated, non-banded, region was smoked through. Overall, the ash appearance of the reduced IP cigarettes, 1-B and 1-C was substantially the same as the control article 1-A.
TABLE 2
IP and Freeburn Results for Control Cigarette 1-A.
IP Pass (%)*
Replicates
Freeburn (%)
Replicates
0
8
100
32
*NIST (10-sheet) filter paper IP test
TABLE 3
IP and Freeburn Results for Samples of 1-B Acquired During A
Manufacturing Trial.
Grab Samples*
IP Pass (%)**
Replicates
Freeburn (%)
Replicates
B-1
87.5
8
100
8
B-2
62.5
8
100
8
B-3
75.0
8
100
8
B-4
100
8
100
8
B-5
87.5
8
100
8
B-6
87.5
8
100
8
B-7
62.5
8
100
8
B-8
87.5
8
100
8
B-9
87.5
8
100
8
B-10
75.0
8
100
8
Average = 81.3
Average = 100
*Sample number: B-# where # is a multiple of about 6000 cigarettes; for example, B-10 refers to about 100 articles taken after about 60,000 cigarettes were made.
**NIST (10-sheet) filter paper IP test
TABLE 4
IP and Freeburn Results for Samples of 1-C Acquired During A
Manufacturing Trial.
Grab Samples
IP Pass (%)*
Replicates
Freeburn (%)
Replicates
C-1
100
8
100
8
C-2
87.5
8
87.5
8
C-3
100
8
87.5
8
C-4
75.0
8
100
8
C-5
87.5
8
100
8
C-6
87.5
8
100
8
C-7
100
8
100
8
C-8
100
8
100
8
C-9
100
8
100
8
C-10
100
8
87.5
8
Average = 93.8
Average = 91.3
*Sample number: C-# where # is a multiple of about 6000 cigarettes; for example, C-10 refers to about 100 articles taken after about 60,000 cigarettes were made.
**NIST (10-sheet) filter paper IP test
EXAMPLE 2
A survey of derivatized starch products was made to determine their suitability for use in preparing a cigarette having reduced IP. RediFilm-54®, RediFilm-250®, and 11527-2 starch compositions were obtained from National Starch (Berkeley, Calif.) as summarized Table 5.
The various starch compositions were used to make a circumferential band, about 7 millimeters wide, around the body of a smoking article. The circumferential band was positioned about 15 millimeters from the ignition end of the finished smoking article. The smoking article was prepared using cigarette paper A, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend.
TABLE 5
Starch Compositions Used.
Starch Product*
Characterization
RediFilm-54 ®
hydrophobic derivatized starch
“low” degree of substitution
water-based composition at 24.66 weight percent
solids
RediFilm-250 ®
hydrophobic derivatized starch
“high” degree of substitution
water-based composition at 23.67 weight percent
solids
11527-2
hydrophobic derivatized starch
experimental, non-commercial product
water-based composition at 9.33 weight percent
solids
*Supplied by National Starch (Berkeley, CA)
A band was applied on the smoking article by hand using an aluminum printing plate, and the wet weight of added material was measured. The applied dry weights of banding materials were calculated and are reported in Table 6.
The NIST (#6) cotton duck IP test was used to determine IP of the banded cigarette samples. For each banded cigarette type, 8 replicates were tested and the results are given in Table 6:
TABLE 6
Summary of Banded Cigarette IP Data.
Starch Product
IP Pass (%)*
Dry band weight (μg)
RediFilm-54 ®
100
222
100
113
100
88
62.5
44
RediFilm-250 ®
100
156
100
88
12.5
38
11527-2
100
94
12.5
36
*NIST (#6) cotton duck IP test
The hydrophobic derivatized starches (RediFilm-54®, RediFilm-250®, and 11527-2) gave low visibility bands when applied on the cigarettes. The IP results indicate that derivatized starch products are effective IP reducing materials. In the present application about 90 micrograms (μg) would be the dry weight that forms a substantially about 100% effective, IP reducing, registered position band.
EXAMPLE 3
Three smoking articles were made using a banded wrapper, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and cigarette tobacco blend. The cigarettes were made on a conventional cigarette-making machine. The smoking articles were made using separate banded cigarette papers.
Cigarette type 3-A was made from cigarette paper A gravure printed with a composition containing about 16.4 weight percent RediFilm-54® starch (National Starch, Berkeley, Calif.) and about 83.6 weight percent tap water. The permeability in the banded region was measured as about 4 CU.
Cigarette type 3-B was made from cigarette paper A gravure printed with a composition containing about 18.18 weight percent Ethylex-2015® hydroxyethylated starch (A. E. Staley, Decatur, Ill.), about 1.01 weight percent DAP (Rhodia, Cranbury, N.J.), and about 80.81 weight percent tap water. The composition heated at approximately 87° C. for about 15 minutes.
Cigarette type 3-C was made from cigarette paper A gravure printed with a composition containing about 18.18 weight percent Ethylex-2065® hydroxyethylated starch (A. E. Staley, Decatur, Ill.), about 1.01 weight percent DAP (Rhodia, Cranbury, N.J.), and about 80.81 weight percent tap water. The composition was heated at approximately 87° C. for about 15 minutes.
During cigarette production, approximately 2,000 cigarettes were collected for each type. The cigarettes were collected such that the individual cigarettes were randomly mixed in a collection box. Therefore, the band positions on the manufactured cigarettes may be characterized as random. The derivatized starches (RediFilm-54®, Ethylex-2015®, and Ethylex-2065®) gave low visibility bands when applied on the cigarettes.
The banded, reduced IP, papers ran substantially the same as non-banded cigarette paper A. No manufacturing problems were observed during cigarette production.
Table 7 indicates IP and freeburn results for cigarettes 3-A, 3-B, and 3-C. Cigarette IP was measured, using about 20 replicates, by the NIST (10-sheet) filter paper test. The freeburn character was measured using about 16 replicates. The IP results indicate that derivatized starch products are effective IP reducing materials in the present application in which band position is random on the individual articles in the population.
TABLE 7
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
Starch Product
IP Pass (%)*
Freeburn (%)
3-A
RediFilm-54 ®
100
0.0
3-B
Ethylex-2015 ®
90
93.8
3-C
Ethylex-2065 ®
100
0.0
*NIST (10-sheet) filter paper IP test
EXAMPLE 4
A series of cigarette types banded with compositions containing varying Flokote-64® starch (National Starch, Berkeley, Calif.) contents was prepared. Compositions were prepared by combining an appropriate amount of starch powder in tap water as summarized in Table 8. The starch/water combination was heated at approximately 90° C. for about 10 minutes.
Cigarette types 4-A, 4-B, 4-C, 4-D, and 4-E were made from cigarette papers gravure printed with starch compositions as listed in Table 8 and 9. Gravure printing was performed using an about 8 millimeter band width and an about 25 millimeter center-to-center spacing. Smoking articles were made using separate banded wrappers, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend. The cigarettes were made on a conventional cigarette-making machine.
During cigarette production, approximately 2,000 cigarettes were collected. The cigarettes were collected such that the individual cigarettes were randomly mixed in a collection box. Therefore, the band positions on the manufactured cigarettes may be characterized as random. The starch compositions gave low visibility bands when applied on the cigarettes.
TABLE 8
Starch Compositions Used.
Composition #
Starch (g)
Water (mL)
Composition (%)*
4-1
600
4000
13.04
4-2
750
4000
15.79
4-3
850
4000
17.53
4-4
1000
4000
20.00
*Weight percent composition Flokote-64 ® starch (National Starch, Berkeley, CA)
TABLE 9
Permeability of Banded Cigarette Paper.
Cigarette Type
Base Paper
Band Solution*
Band Perm. (CU)**
4-A
A
4-1
10
4-B
A
4-2
8
4-C
A
4-3
6
4-D
A
4-4
4
4-E
B
4-4
5
*See Table 7
**Perm. = permeability
Table 10 indicates IP and freeburn results for cigarette types 4-A, 4-B, 4-C, 4-D, and 4-E. Cigarette IP was measured, using about 20 replicates, by the NIST (10-sheet) filter paper test. The freeburn character was measured using about 6 replicates. The results indicate that significant IP reduction occurs when the band permeability is reduced to less than about 6 CU. The applied permeability reducing agent may be adjusted, such as controlling percent weight, viscosity or the like, to give an effective IP reducing band in the present application in which band position is random on the individual articles in the population.
TABLE 10
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
IP Pass (%)*
Freeburn (%)
4-A
0
100
4-B
0
100
4-C
40
100
4-D
95
95
4-E
85
100
*NIST (10-sheet) filter paper IP test
Applicants evaluated the smoke taste profile of cigarette type 4-D. The taste when smoking within banded areas differed from the taste in the untreated, non-banded, areas. The band region was characterized as possessing less taste strength and a slight paper-like taste relative to the untreated, non-banded, region.
EXAMPLE 5
A series of cigarette types banded with compositions containing varying Flokote-64® starch (National Starch, Berkeley, Calif.) and DAP (Rhodia, Cranbury, N.J.) contents was prepared. Compositions were prepared by combining an appropriate amount of starch powder and DAP in tap water as summarized in Table 11. The combinations were heated at approximately 90° C. for about 15 minutes.
Cigarette types 5-A through 5-L were made from cigarette papers gravure printed with starch compositions as listed in Table 11 and 12. All cigarette types had a band configuration of about 6 millimeter width and about 25 millimeter center-to-center spacing except types 5-I and 5-J which had a band configuration of about 8 millimeter width and about 25 millimeter center-to-center spacing.
Smoking articles were made using separate banded wrappers, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend. The cigarettes were made on a conventional cigarette-making machine.
TABLE 11
Starch Compositions Used.
Composition #
Starch (g)
DAP (g)
Water (mL)
Composition*
5-1
900
0
4000
18.37% S
5-2
900
12.5
4000
18.27% S, 0.25%
DAP
5-3
900
25
4000
18.32% S, 0.51%
DAP
5-4
900
50
4000
18.18% S, 1.01%
DAP
5-5
900
150
4000
17.82% S, 2.97%
DAP
5-6
900
200
4000
17.65% S, 3.92%
DAP
5-7
900
300
4000
17.31% S, 5.77%
DAP
5-8
1000
0
4000
20.00% S
5-9
1040
150
4000
20.04% S, 2.89%
DAP
5-10
1100
50
4000
21.36% S, 0.97%
DAP
5-11
1250
50
4000
23.58% S, 0.94%
DAP
*Weight percent composition:
S = Flokote-64 ® starch (National Starch, Berkeley, CA),
DAP = diammonium phosphate (Rhodia, Cranbury, NJ)
During cigarette manufacture, approximately 2,000 cigarettes were collected. The cigarettes were collected such that the individual cigarettes were randomly mixed in a collection box. Therefore, the band positions on the manufactured cigarettes may be characterized as random. The starch compositions gave low visibility bands when applied on the cigarettes.
Table 13 indicates IP and freeburn results for cigarette types 5-A through 5-L. Cigarette IP was measured, using about 20 replicates, by the NIST (10-sheet) filter paper test. The freeburn character was measured using about 16 replicates. The results indicate that significant IP reduction occurs when the band permeability is less than about 6 CU, although for the present example freeburn was significantly lowered for the about 4 CU and about 3 CU band permeability samples.
TABLE 12
Permeability of Banded Cigarette Paper.
Cigarette Type
Base Paper
Band Solution*
Band Perm. (CU)**
5-A
A
5-1
6
5-B
A
5-2
--
5-C
A
5-3
--
5-D
A
5-4
6
5-E
A
5-5
6
5-F
A
5-6
6
5-G
A
5-7
6
5-H
A
5-8
--
5-I
A
5-9
3
5-J
B
5-9
4
5-K
A
5-10
--
5-L
A
5-11
--
*See Table 11
**Perm. = permeability
--= not determined
TABLE 13
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
IP Pass (%)*
Freeburn (%)
5-A
90
100
5-B
100
93.8
5-C
100
93.8
5-D
100
100
5-E
100
93.8
5-F
100
100
5-G
90
93.8
5-H
100
0
5-I
100
0
5-J
100
10
5-K
100
0
5-L
100
6.3
*NIST (10-sheet) filter paper IP test
Applicants evaluated the smoke taste profile of cigarette types 5-A through 5-G. The taste when smoking within banded areas differed from the taste in the untreated, non-banded, areas. The band region was characterized as possessing less taste strength relative to the untreated, non-banded, region. In contrast to cigarette type 4-D (Example 4), the presence of DAP eliminated the slight paper-like taste attributed to using a permeability reducing agent alone to form the banded region. Moreover, composition 5-4 (1.01 weight percent DAP) was sufficient to afford the maximal benefit of DAP presence. Higher contents of DAP, such as composition 5-7, tended to increase the width of the char line as the banded region was smoked through.
EXAMPLE 6
A series of cigarette types banded with compositions containing varying Flokote-64® starch (National Starch, Berkeley, Calif.) and DAP (Rhodia, Cranbury, N.J.), and sodium/potassium citrate salt contents was prepared. Smoking articles were made using separate banded wrappers, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend. The cigarettes were made on a conventional cigarette-making machine.
Cigarette type 6-A was made from cigarette paper A gravure printed with a composition containing about 20.65 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 0.94 weight percent DAP (Rhodia, Cranbury, N.J.), 3.32 weight percent citrate salt, and about 75.09 weight percent tap water. The citrate salt was a mixture of sodium citrate dihydrate (Fisher Scientific, Fair Lawn, N.J.) and potassium citrate monohydrate (Fisher Scientific, Fair Lawn, N.J.) in an about 1:2.8 weight/weight ratio. The composition was heated at approximately 87° C. for about 15 minutes.
Cigarette type 6-B was made from cigarette paper A gravure printed with a composition containing about 21.36 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 0.97 weight percent DAP (Rhodia, Cranbury, N.J.), and about 77.67 weight percent tap water. The composition was heated approximately 87° C. for about 15 minutes.
Cigarette type 6-C was made from cigarette paper A gravure printed with a composition containing about 19.56 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 0.89 weight percent DAP (Rhodia, Cranbury, N.J.), about 8.44 weight percent citrate salt, and about 71.11 weight percent tap water. The citrate salt was a mixture of sodium citrate dihydrate (Fisher Scientific, Fair Lawn, N.J.) and potassium citrate monohydrate (J. T. Baker, Phillipsburg, N.J.) in an about 1:2.8 weight/weight ratio. The composition was heated at approximately 87° C. for about 15 minutes.
During cigarette manufacture, approximately 2,000 cigarettes were collected. The cigarettes were collected such that the individual cigarettes were randomly mixed in a collection box. Therefore, the band positions on the manufactured cigarettes may be characterized as random. The starch compositions gave low visibility bands when applied on the cigarettes.
Table 14 indicates IP and freeburn results for cigarette types 6-A, 6-B, and 6-C. Cigarette IP was measured, using about 20 replicates, by the NIST (10-sheet) filter paper test. The freeburn character was measured using about 64 replicates for article types 6-A and 6-B and about 16 replicates for article type 6-C.
TABLE 14
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
IP Pass (%)*
Freeburn (%)
6-A
100
87.5
6-B
100
34.4
6-C
100
90.0
*NIST (10-sheet) filter paper IP test
Both the burn rate retarding substance (such as DAP) and the burn rate accelerating substance (such as sodium/potassium citrate salt) are beneficial band additives that influence the ability of the article to freeburn. High levels of the permeability reducing substance (such as starch) deposited in the band may increase the IP pass rate of the cigarette (see Example 4), but will decrease the ability of the cigarette to freeburn particularly when combined with the burn rate retarding substance (see Example 5). The burn rate accelerating substance (such as sodium/potassium citrate salt) is a beneficial band component because this burn promoter can be used to increase the ability of a heavily banded cigarette to freeburn while maintaining concurrent reduced IP character.
Furthermore, applicants have discovered the unexpected organoleptic enhancing abilities of the burn rate accelerating substance preferably in combination with the burn rate retarding substance. The smoke taste profile of cigarette 6-C was substantially consistent when smoking within banded areas and smoking in the untreated, non-banded, areas.
EXAMPLE 7
Two smoking articles were made using a banded wrapper, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and cigarette tobacco blend. The cigarettes were made on a conventional cigarette-making machine. The smoking articles were made using separate banded cigarette papers.
Cigarette type 7-A was made from cigarette paper A gravure printed with a composition containing about 18.18 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 1.01 weight percent monoammonium phosphate (Fisher Scientific, Fair Lawn, N.J.), and about 80.81 weight percent tap water. The composition was heated at approximately 87° for about 15 minutes.
Cigarette type 7-B was made from cigarette paper A gravure printed with a composition containing about 17.82 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 2.97 weight percent monoammonium phosphate (Fisher Scientific, Fair Lawn, N.J.), and about 79.21 weight percent tap water. The composition was heated at approximately 87° C. for about 15 minutes.
During cigarette production, approximately 2,000 cigarettes were collected for each type. The cigarettes were collected such that the individual cigarettes were randomly mixed in a collection box. Therefore, the band positions on the manufactured cigarettes may be characterized as random. The banded, reduced IP, papers ran substantially the same as non-banded cigarette paper A. No manufacturing problems were observed during cigarette production.
Table 15 indicates IP and freeburn results for cigarettes 7-A and 7-B. Article IP was measured, using about 20 replicates, by the NIST (10-sheet) filter paper test. The freeburn character was measured using about 16 replicates. The IP results indicate that starch combined with monoammonium phosphate is an effective IP reducing material in the present application in which band position is random on the individual articles in the population.
TABLE 15
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
IP Pass (%)**
Freeburn (%)
7-A
100
43.8
7-B
100
62.5
**NIST (10-sheet) filter paper IP test
EXAMPLE 8
One smoking articles was made using a banded wrapper, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and cigarette tobacco blend. The cigarette was made on a conventional cigarette-making machine.
Cigarette type 8-A was made from cigarette paper A gravure printed with a composition containing about 15.24 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 0.95 weight percent DAP (Rhodia, Carnbury, N.J.), about 7.62 weight percent microcrystalline cellulose (Aldrich, Milwaukee, Wis., Catalog #31,069-7), and about 76.19 weight percent tap water. The starch/DAP composition heated at approximately 87° C. for about 15 minutes then the cellulose component was dispersed before printing.
During manufacturing, approximately 2,000 articles of type 8-A were collected. The cigarettes were collected such that the individual cigarettes were randomly mixed in a collection box. Therefore, the band positions on the manufactured cigarettes may be characterized as random. The banded, reduced IP, papers ran substantially the same as non-banded cigarette paper A. No manufacturing problems were observed during cigarette production.
The composition used to band article type 8-B contained about 14.61 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 0.97 weight percent DAP (Rhodia, Carnbury, N.J.), about 2.16 weight percent sodium citrate dihydrate (Fisher Scientific, Fair Lawn, N.J.), about 6.05 weight percent potassium citrate monohydrate (J. T. Baker, Phillipsburg, N.J.), about 4.40 weight percent colloidal cellulose (Aldrich, Milwaukee, Wis.; Catalog #43,524-4), and about 71.82 weight percent tap water. The starch/DAP/citrate salt composition was heated at approximately 90° C. for about 20 minutes then the cellulose component was dispersed before applying the material to articles.
Cigarette type 8-B was hand banded with the starch/DAP/cellulose composition to give a circumferential band, about 7 millimeters wide, around the body of a smoking article. The circumferential band was positioned about 20 millimeters from the ignition end of the finished article. The smoking article was prepared using cigarette paper A, an about 72 millimeter tobacco column length, an about 25 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend.
The fixed-position band of article type 8-B was applied on the smoking article by hand using an aluminum printing plate, and the wet weight of added material was measured. The applied total dry weight of banding material was calculated to be about 1.4 milligrams.
Table 16 indicates IP and freeburn results for cigarettes 8-A and 8-B. Cigarette IP was measured, using about 20 replicates for 8-A and 4 replicates for 8-B, by the NIST (10-sheet) filter paper test. The freeburn character was measured using about 16 replicates for 8-A and 4 replicates for 8-B. The IP results indicate that starch/DAP, or more preferably starch/DAP/citrate salt, combined with cellulose is an effective IP reducing material in the present application in which band position is either random or fixed on the individual articles in the population.
TABLE 16
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
IP Pass (%)*
Freeburn (%)
8-A
45
100
8-B
100
100
*NIST (10-sheet) filter paper IP test
EXAMPLE 9
Cigarette types 9-A and 9-B were hand banded with compositions to give a circumferential band, about 7 millimeters wide, around the body of a smoking article. The circumferential band was positioned about 20 millimeters from the ignition end of the finished article. The smoking article was prepared using cigarette paper A, an about 72 millimeter tobacco column length, an about 25 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend.
The fixed-position band of was applied on the smoking article by hand using an aluminum printing plate, and the wet weight of added material was measured. The applied dry weights of banding materials were calculated and found to be about 1.4 milligrams (total dry material weight) for article type 9-A and about 0.82 milligrams (total dry material weight) for article type 9-B.
The composition used to band article type 9-A contained about 14.47 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), 0.96 weight percent DAP (Rhodia, Carnbury, N.J.), about 2.14 weight percent sodium citrate dihydrate (Fisher Scientific, Fair Lawn, N.J.), about 6.00 weight percent potassium citrate monohydrate (J. T. Baker, Phillipsburg, N.J.), about 5.30 weight percent calcium carbonate (Aldrich, Milwaukee, Wis.; Catalog #31,003-4), and about 71.14 weight percent tap water. The starch/DAP/citrate salt composition was heated at approximately 90° C. for about 20 minutes then the calcium carbonate component was dispersed before applying the material to the articles.
The composition used to band article type 9-B contained about 14.56 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), 0.96 weight percent DAP (Rhodia, Carnbury, N.J.), about 2.15 weight percent sodium citrate dihydrate (Fisher Scientific, Fair Lawn, N.J.), about 6.04 weight percent potassium citrate monohydrate (J. T. Baker, Phillipsburg, N.J.), about 4.70 weight percent Kaolin clay (Aldrich, Milwaukee, Wis.; Catalog #22,883-4), and about 71.59 weight percent tap water. The starch/DAP/citrate salt composition was heated at approximately 90° C. for about 20 minutes then the Kaolin clay component was dispersed before applying the material to the articles.
Table 17 indicates IP and freeburn results for cigarettes 9-A and 9-B. Cigarette IP was measured, using about 4 replicates, by the NIST (10-sheet) filter paper test. The freeburn character was measured using about 4 replicates. The IP results indicate that starch/DAP/citrate salt combined with filler, such as calcium carbonate, clay, and the like, is an effective IP reducing material in the present application in which band position is fixed on the individual articles in the population.
Applicants anticipate that the composition applied to articles may be adjusted due to synergistic interactions between filler and other band components. For example, article 9-B incorporates Kaolin clay as a band component, which appears to synergistically enhance the performance of the bum rate retarding substance and/or the permeability reducing substance. As a further example, article 9-A incorporates an alkaline-earth metal containing salt, calcium carbonate, known to act as paper burn rate accelerating substance, which may interact synergistically with the burn rate accelerating component. Alternatively, the filler component may cooperate with the permeability reducing substance.
TABLE 17
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
IP Pass (%)*
Freeburn (%)
9-A
100
100
9-B
100
25
*NIST (10-sheet) filter paper IP test
EXAMPLE 10
A series of base cigarette papers were banded with a composition containing Flokote-64® starch (National Starch, Berkeley, Calif.) and DAP (Rhodia, Cranbury, N.J.). Smoking articles were made using separate banded wrappers, an about 63 millimeter tobacco column length, an about 21 millimeter cellulose acetate non-air diluted filter section, and a cigarette tobacco blend. The cigarettes were made on a conventional cigarette-making machine.
Cigarette types were made from a series of cigarette papers, as listed in Table 18, gravure printed with a composition containing about 21.36 weight percent Flokote-64® starch (National Starch, Berkeley, Calif.), about 0.97 weight percent DAP (Rhodia, Cranbury, N.J.), and about 77.67 weight percent tap water. The composition was heated at approximately 87° C. for about 15 minutes.
TABLE 18
Summary of Banded Cigarette IP and Freeburn Data.
Cigarette Type
Base Paper
IP Pass (%)*
Freeburn (%)
10-A
A
100
34
10-B
D
100
56.3
10-C
E
100
57.0
10-D
F
100
62.5
10-E
G
80
100
10-F
A**
100
43.8
10-G
H
50
100
*NIST (10-sheet) filter paper IP test
**Base paper A electrostatically perforated to about 70 CU
During manufacturing, approximately 2,000 articles of type 10-A through 10-G were collected. The cigarettes were collected such that the individual cigarettes were randomly mixed in a collection box. Therefore, the band positions on the manufactured cigarettes may be characterized as random. The banded, reduced IP, papers ran substantially the same as non-banded cigarette paper A. No manufacturing problems were observed during cigarette production.
The IP and freeburn data in Table 18 demonstrate that at constant applied band composition, and application method, results may vary depending on the structure of the base paper. Articles prepared from the higher permeability papers, 10-E and 10-H, showed lower IP pass rates than articles 10-A through 10-F. Applicants believe that increasing the applied amount of the composition will increase IP pass rate for higher base paper permeability types (such as 10-E and 10-G). For articles 10-A through 10-D and 10-F applicants fully expect that the freeburn value may be increased by the incorporation of a burn rate accelerating substance in the band.
Article type 10-F used an about 18 CU base paper (A) electrostatically perforated, before band printing, to about 70 CU. After banding, the permeability in the band region was measured as about 57 CU. Article type 10-A, utilizing base paper A, had a measured band permeability of about 5 CU. Interestingly, article types 10-A and 10-F gave similar IP and freeburn results. This example demonstrates the unexpected result that perforation in the banded region, at the level applied, does not degrade the IP performance. Applicants fully anticipate higher levels of perforation may give similar results.
An important consideration for the design of commercially acceptable reduced IP articles is product smoke delivery. Smoke delivery is the quantity of various smoke components produced by the article during its consumption. For this example, carbon monoxide was used as a surrogate for all components delivered by the article. An article manufactured from a paper containing a banded region of lower permeability than the non-banded region may display increased smoke delivery relative to the non-banded control article. The width, spacing, composition, and number of the bands may also affect smoke delivery changes.
For example in Table 19, an article type prepared from base paper A gave a carbon monoxide delivery of about 18.2 milligrams/cigarette, but the same wrapper in a banded state (band permeability about 5 CU) caused the delivery to increase to about 21.3 milligrams/cigarette. Applicants have demonstrated that substituting a higher permeability base paper will afford smoke deliveries similar to the control type (for example 10-B through 10-G versus control).
Additionally, applicants have discovered the unexpected result that incorporating a burn accelerating substance in the band (such as article type 6-C) can give a lower smoke delivery relative to the banded article not containing the burn accelerating substance (such article type 10-A).
TABLE 19
Carbon Monoxide Content of Banded and Control Articles.
Cigarette Type
Carbon Monoxide (milligrams/cigarette)
Control*
18.2
10-A
21.3
6-C
20.6
10-B
18.3
10-C
18.4
10-D
17.6
10-E
17.3
10-F
18.5
10-G
17.6
*Control, non-banded, article manufactured with base paper A
Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. By way of example, an alternative method for controlling smoke delivery may be used. Examples of such alternative methods include diluting filter smoke with air, changing tobacco blend, and altering base paper burn regulator composition. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims. | A smoking article having reduced ignition propensity is disclosed. The smoking article includes a tobacco column, a wrapper surrounding the tobacco column and a filter element. The wrapper has a base permeability, an untreated area and a least one discrete area treated with a composition to reducing the base permeability. The discretely treated area interacts with a coal of a burning tobacco firecone as it advances to self-extinguish the smoking article. The composition of the treated area includes a permeability reducing substance, a burn rate retarding substance and a burn rate accelerating substance. Either the burn rate retarding substance or the burn rate accelerating substance acts as an organoleptic enhancing substance. In this way a smoker's experience when smoking either the at least one treated area or the untreated area is substantially the same. | 2 |
BACKGROUND OF THE INVENTION
Reissue Patent, Re. No. 32,395 discloses several forms of compression piston ring construction including a thin multi-sector ring having free circumferential curvature equal to the cylinder wall wherein each sector is provided with a "microspring" formed by partial radial cuttings leaving a spring element therebetween. Each of the three sectors is made slightly greater than 120°, so that circumferential compression upon installation will maintain radial cylinder wall contact with sufficient microspring clearance remaining at the cuttings to accommodate thermal expansion in operation. As a sealing element for clearance gaps at the microsprings, a supplemental single piece plastic ring, made of a material such as Teflon capable of operation without gap at its single cutting ends, is disclosed for installation under the metal ring sectors on the crankcase side to seal against any leakage through the microspring partial cuttings.
Such supplemental plastic sealing ring has been found satisfactory in operation where temperatures do not exceed 400°; however, higher operating temperatures in the order of 500° encountered in high performance engines exceed the operating temperature limits of the plastic.
SUMMARY OF THE INVENTION
In order to accommodate higher temperature operation, a second layer of segmented metal ring sectors is employed in a manner dispensing with the plastic ring.
In a first embodiment, microsprings are omitted and each sector is identically constructed with slightly less than 120° arc to provide end clearance for thermal expansion, with a wave spring employed at the inside of the piston groove to urge the segments into radial contact with the cylinder wall. A slight notch in a sector of each layer engaged by a single slight projection in the wave spring maintains an overlapping orientation of the respective layers so that every end gap is covered by the adjacent layer. As an additional provision to block single layer radial leak paths, the wave spring is configured with a width equal to the combined thickness of the metal sectors, and with convolutions spaced to engage the segments of both layers at every sector end.
In a second embodiment, ends of the sectors are constructed with overlapping tongue extensions which maintain contact against radial passage throughout all thermal conditions with sufficient end clearance provided for maximum thermal expansion.
In a third embodiment, each layer comprises three metal sectors, each identically constructed with a microspring similar to the disclosure in said reissue patent, and with circumferential interengagement provided to assure interlayer overlap coverage of each layer's microspring gaps.
In a fourth embodiment, the microsprings in respective layers are differently spaced to assure no possible axial alignment of microsprings at more than one location, notwithstanding absence of any relative circumferential orientation between layers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a single sector employed in the first embodiment;
FIG. 2 is an enlarged sectional plan view of a piston ring and cylinder assembly employing six of the segments shown in FIG. 1;
FIG. 3 is a greatly enlarged fragmentary sectional view illustrating a free-state assembly of the wave spring shown in FIG. 2 installed in a piston groove;
FIG. 4 is a view similar to FIG. 3 taken along the line 4--4 of FIG. 2 illustrating the wave spring compressed by piston ring sectors installed in the piston;
FIG. 5 is a fragmentary enlarged view of the second embodiment having overlapping tongue ends of adjacent sectors;
FIG. 6 is a fragmentary further enlarged view of one overlapping joint taken from the circle 6 of FIG. 5;
FIG. 7 is a plan view of a wave spring in a free state condition prior to installation in the piston groove;
FIG. 8 is a plan view of one layer of three sectors employed in the third embodiment with two overlapping layers each having three identical microspring sectors;
FIG. 9 is an enlarged fragmentary sectional view of a piston groove with two layers of FIG. 8 sectors installed;
FIG. 10 is a fragmentary view of a modified microspring;
FIG. 11 is a plan view of a second layer of three sectors employed in the fourth embodiment;
FIG. 12 is an enlarged view of a single sector with a microspring typical of those shown in FIGS. 8 and 11.
FIG. 13 is a plan view of a sleeve for a spring coil from which 120° sectors are to be cut in manufacturing ring sectors.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1-4, piston 10 installed within cylinder wall 11 has six metal compression ring sectors 12 installed within piston groove 13 in two 3-sector layers, 14a and 14b held in overlapping relationship with respective ends such as 15a of one layer extending midway between adjacent ends 15b of the other layer. Such relationship is maintained by a single projection 16 of wave spring 17 engaging a pair of aligned notches 18 in one segment of each of the layers. Wave spring 17 shown with groove installed free convolution extension 19 in FIG. 3 is compressed with intermediate contact against groove bottom 20 to an operating position 21 with only slight clearance 22 relative to groove bottom 20. As shown in FIG. 2, each convolution of wave spring 17 is spaced relative to projection 16 to directly engage respective ring sectors at each juncture 23, to effectively block any radial leak path through either layer.
Outer perimeter 24 of each sector is provided with a free form curvature matching cylinder wall 11 and extends through an arc slightly less than 120° providing clearance 25 adequate for thermal expansion without compressive end loading.
With reference to FIGS. 3 and 7, each convolution of the wave spring extension preferably is formed to span the bottom of the groove during radial compression by ring installation to an operating condition as shown in FIGS. 2 and 4. The radial inner connection between each radially extending convolution should contact the bottom of the groove in tangential relation with a radiused bend at said connection to establish a free state contracted ring configuration relative to the circumference of the groove bottom shown as a reference outer circle in FIG. 7. This is provided to require ring expansion for installation with resulting opening stress throughout when installed as shown in FIG. 3. Such stress permits retention of groove bottom contact as the extended convolution is radially compressed by ring sector installation.
Ends of the wave spring should also be radiused to maintain spanning contact during radial compression so that bore contact pressure will be limited to the radial force required to substantially conform the respective radially extending convolutions to approach groove bottom curvature. In establishing the required free form for radial projecting convolutions, formulae for beams freely supported at the ends deflected by concentrated force at the center have approximate application using the deflection curve in reverse as the free form curve for a convolution which will compress toward the piston groove bottom with its ends engaging the bottom. However, in some respects, the connection between convolutions creates a condition similar to a beam fixed at both ends with a load at the center. This again is not accurately representative of the condition because the connection between convolutions does not completely fix the ends against angular deflection upon radial compression of the projecting convolutions. Accordingly, applicants have found experimentally, that provision of a free form approaching deflection of a beam supported at both ends with a load at the center, supplemented by a slight uniform radius bend at the end connections of the projecting convolutions to produce a reduced preformed circumference corresponding to that illustrated in FIG. 7, with a similar curvature applied to the respective ends of the wave spring will produce the desired result such as illustrated in FIG. 2. A desired light radial spring force only sufficient to maintain ring contact with the cylinder bore during operation is readily achieved with appropriate wave spring thickness and convolution spacing, thereby minimizing piston friction which contributes to substantial power loss with conventional integral expansion rings.
Optionally, a thinner spring may be employed when configured to wrap on the groove bottom when deflected by ring sector installation due to decreasing effective spring length rather than spanning contact; or as another alternative by providing more convolutions with shorter spanning contacts. With such alternative configurations, spring thickness in the order of 0.05 to 0.10 millimeter may be employed. However, the preferred embodiment with spanning contacts as illustrated in FIG. 2 involve greater spring thickness for equivalent radial force on the ring sectors which may be a substantial fraction of the height engaging the dual ring layers appropriate for construction by flattening round spring wire to the required substantially rectangular wave spring section.
Typical ring dimensions appropriate for an 82 millimeter cylinder bore diameter are 0.6 millimeter thickness for each layer, 3.6 millimeter radial width, 0.03 millimeter axial groove clearance, 0.2 millimeter end gap per sector for thermal expansion (approximately 1° sum of three gaps), and a wave spring of approximately 0.5 millimeter thickness.
With reference to FIGS. 5 and 6, the modified second embodiment provides overlapping mating tongue extensions 26 with arcuate expansion joint 27 and thermal expansion clearance gaps 28 to effectively block radial passage at each layer. Such provision may be in lieu of or in addition to wave spring contact at the joints.
With reference to FIG. 8, the third embodiment employs double layer microspring sectors held in relative overlapping orientation by suitable means such as the hole and semipierce projection 29 illustrated in FIG. 9 with adequate clearance therebetween for free axial clearance as shown. In FIG. 10, a modified triangular partial cut is provided at 30 on either side of microspring 31 to facilitate manufacture by stamping with more body for the punch elements. The enlarged axial passages of such modification are not detrimental when completely covered by the adjacent layer.
With reference to FIG. 11, the second layer of three sectors employed in the fourth embodiment, having nonuniform spacing of microsprings in two of the three segments as shown at 32 and one sector having a central microspring as shown at 34, when combined with the layer shown in FIG. 8 having uniformly spaced microsprings as shown at 33, assures an axial alignment of microsprings at no more than one location, with chances approximately 359:1 against such alignment, thereby minimizing potential leakage through axially aligned microsprings. In this case, the partial cutting gaps forming the microsprings are held to a minimum width to allow for initial compression on installation plus thermal expansion in operation.
With reference to FIG. 12, appropriate dimensions in millimeters, for the partial cutting gaps and microspring illustrated are approximately a=0.40; b=0.55; d=0.30; and e=0.07; the last figure accommodating initial compression partially closing the gaps d. As in the case of the first two embodiments, a thickness of 0.6 millimeters, radial width of 3.60 millimeters and outer circumferential radius of 41 millimeters are appropriate.
In the operation of the FIG. 1 and 2 embodiments, there is no requirement for the ring segments per se to have spring properties. Accordingly, materials other than spring stock may be employed which will have optimum compatibility with bore surface, effective compression seal, low friction, and durability as well as to facilitate manufacturing processes such as fine blanking, or optionally using coiled rectangular wire stock from which ring sectors may be cut.
With reference to FIG. 13, an example of tooling which may be used in cutting segment sectors from coiled stock is illustrated, including a tooling sleeve 35 extending for slightly less than 240° having ends 36 adjacent sector cut lines 37 and 38 of the coiled spring which has been prewound and accurately finished to required outside and inside surfaces before installation in the sleeve, particularly with reference to the OD which may be precision ground to exactly match the cylinder bore. End caps, not shown, may be employed to compressively retain the stacks of coiled sectors during the cutting. In cutting through the entire coil at the end location 37 by slitting saw or thin cutoff disc, the opposite end of the coil will be preferably located directly under the end 37, so that separate layers will result from the initial cut with a shift of one layer to produce alignment of each single coil layer. Upon making a second cut at 120° spacing 38 from the first cut at 37, a stack of 120° sector segments will result opening the interior of the coil to further processing. At this stage, a single notch 39 may be produced in the entire length of the remaining coil by suitable cutting or grinding tool followed by a final cut at 40 to complete the processing of three segments per layer for the entire coil. The gap resulting from cutting the three 120° sectors will be appropriate for thermal expansion required in the first embodiment with virtually no significant loss of material from the initial wire stock employed in producing the coil.
The provision of a single notch 39 in one of the three sectors of each ring will require turning over one of the two notched layers in order to achieve the overlap condition illustrated in FIG. 2. Optionally, a second notch could be provided at a 30° spacing from end 37 to eliminate the requirement for such turnover orientation at assembly so that merely a proper indexing of the respective layers will achieve required alignment of a pair of notches 18 as illustrated in FIG. 2.
In the case of fine blanking, two corresponding notches could readily be provided in all segments so that no segment segregation would be required for assembly purposes. However, in case of the processing illustrated in FIG. 13, corresponding notches in the first stack of segments removed by initial cutting would require additional processing setup and selective orientation, including turnover of alternate sectors, incident to the single notch illustrated may be preferred to secondary processing steps for additional notches.
In view of the multiplicity of six ring segments in addition to the wave spring for assembly in each piston compression ring groove, automatic assembly techniques may be in order which, however, are outside of the scope of the present application. Likewise, in the case of the wave spring partial fabrication at assembly to produce the six radially projecting convolutions and end projection 16, would permit prefabrication of flat wire stock in substantial continuous quantity on a reel located at assembly which would feed the spring wire to forming and cutoff rolls adjacent the piston ring groove so that direct, automatic feeding of the formed wave spring into the piston groove may be accomplished. It would of course be necessary to develop such rolls empirically with proper allowance for spring back to achieve the desired groove installation form as illustrated in FIG. 3 and the necessary expanding stress incident to a free form such as illustrated in FIG. 7.
While the manufacturing process illustrated in FIG. 13 is not appropriate for other than the first embodiment, fine blanking may readily be employed to produce the segments of the second embodiment illustrated in FIGS. 5 and 6. | Compression piston ring for internal combustion or compressor cylinder and piston comprising double layer of segmented ring sectors having free form circumferential curvature matching the cylinder bore. The double layers are adapted to effectively seal or minimize bypass with resilient means provided for maintaining ring cylinder engagement under light radial pressure. | 8 |
FIELD OF THE INVENTION
[0001] The present invention is in the field of implantable medical devices, particularly, scaffolds and matrices for breast reconstruction or hernia repair.
BACKGROUND OF THE INVENTION
[0002] A hernia is an abnormal protrusion of a peritoneal-lined sac through the musculo-aponeuronic covering of the abdomen. The most common treatment for a hernia is surgery to repair the opening in the muscle wall. Operations for hernias are among the most common procedures performed today, with about 750,000 hernia repairs performed annually.
[0003] Surgery involves an abdominal incision, after which the protruding tissue is either removed or pushed back into the abdomen and the abdominal wall is repaired and strengthened. The abdominal wall can be strengthened by sewing surrounding muscle over it, or it can be strengthened with a special type of mesh. Unfortunately, there have been several reports of complications with some mesh products used in hernia repair.
[0004] In a study performed by Junge et al, “ Elasticity of the anterior abdominal wall and impact for reparation of incisional hernias using mesh implants ”, Hernia, 5:113-118 (2001), the elasticity of the abdominal wall was measured and compared to that of commercially available non-resorbable hernia mesh implants. It was assumed that the flexibility of the abdominal wall is restricted by extensive implantation of large mesh implants, the more so if the mesh implants are integrated into scar tissue. In addition, the non-physiological stretching capability of the mesh implants contrast with the highly elastic abdominal wall and can give rise to shearing forces, favoring increased local remodeling and thus recurrence at the margin. It was concluded that mesh implants used for repairing incisional hernia should have an elasticity of at least 25% in vertical stretching and 15% in the horizontal stretching when subjected to a tensile strength of 16 N/cm, in order to achieve almost physiological properties.
[0005] U.S. Pat. No. 8,016,841 to Magnusson et al. (assigned to Novus Scientific Pte, Ltd.) describes a mesh implant with an interlocking knitted structure and indicates that this mesh is useful for hernia repairs. The mesh contains two or more sets of fibers with different degradation times. This mesh allegedly gradually adjusts to match the conditions of the underlying tissue structures, such as the abdominal wall, through the degradation of the first type of fibers. This mesh maybe formed using any knitting technique, and is preferably knitted using a warp-knit procedure. However, this mesh implant is initially a rigid material that becomes more flexible as one layer resorbs. This rigidity can cause problems and issues identified in study performed by Junge et al mentioned above. The initial rigidity could also cause shearing and tearing, resulting in more scarring.
[0006] Therefore there is a need for improved materials and methods for repairing hernias.
[0007] Breast reconstruction is the rebuilding of a breast that has been removed due to cancer or other diseases. This procedure involves the use of implants or relocated flaps of the patients own tissue to create a natural looking breast and reformation of a natural looking areola and nipple. In some situations, reconstruction may be possible immediately following breast removal. But in individuals with medical problems, like high blood pressure, obesity, and/or diabetes, the surgery is typically delayed. Breast reconstruction usually takes multiple operations, which are spread out over weeks or months.
[0008] The skin sparing mastectomy enables the muscle to be detached inferiorly where the lower skin flap affords coverage to the implant. Although more natural expansion (compared to earlier surgical techniques, such as the total muscle coverage technique) is possible due to the release of the pectoralis muscle, pectoral muscle retraction and implant bottoming out is still a problem.
[0009] Suturing the inferior edge of the muscle to the fascia therefore becomes necessary. The suturing technique often results in disruption, as sutures cut through the tissues with tension. Acellular dermal matrices (ACDM) have been used to solve this problem. The ACDM provides reinforcement to the muscle and also provides supplemental tissue to the space between the released muscle and the inframmary fold. However, problems encountered with ACDM include, seroma, infection, disruption, patient concerns and costs.
[0010] TIGR mesh, a synthetic, absorbable, woven scaffold has recently been used in breast reconstruction as a replacement for ACDM. However, this mesh implant is initially a rigid and becomes more flexible as one layer resorbs. The initial rigidity can cause shearing and tearing, resulting in more scarring. Additionally, the initial rigidity of this material could cause post-operative discomfort for the patient.
[0011] Therefore there is a need for improved materials and methods for breast reconstruction.
[0012] It is an object of the present invention to provide a resorbable, biocompatible device for breast reconstruction.
[0013] It is further object of the present invention to provide a resorbable, biocompatible device for hernia repair.
[0014] It is still another object of the present invention to provide an improved method for breast reconstruction, particularly following a mastectomy.
[0015] It is yet a further object of the present invention the present invention to provide an improved method for hernia repair.
SUMMARY OF THE INVENTION
[0016] A three-dimensional braided, rather than woven, polymeric matrix has been developed to provide mechanical support in a breast reconstruction or mastopexy procedure. The three-dimensional braided matrix described herein may alternatively be used to provide support in hernia repair procedures.
[0017] The device consists of an inter-connected, open pore structure that enables even and random distribution and in-growth of cells. The braided structure allows for distribution of mechanical forces over a larger area of tissue at the fixation point(s) compared to woven meshes.
[0018] The matrix is a supple, strong, but flexible and more comfortable material that can almost double in size when stretched along the vertical plane, but only extends by about 10% to 20% in length when stretched along the horizontal plane.
[0019] The three-dimensional braided matrix is formed of multifilament polymeric fibers plied to create yarn bundles. The matrix can be formed of fibers formed from one or more degradable polymers. The degradable matrix is designed to degrade after a period of about six to twelve months following implantation. The matrix will not be completely degraded at this point, rather, the device will degrade to the extent that it loses structural integrity about six to twelve months following implantation. This time period allows the matrix to provide the required structural and flexible mechanical support to support the repair or augmentation of the breast tissue or the abdominal wall, followed by degradation when the support is no longer needed.
[0020] The matrix is manufactured using 3-D braiding or attachment of a two dimensional braid to additional strands or braid to create the proper porosity for cell ingrowth.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1A-C are illustrations of a three dimensional (3-D) braided matrix that can be used in hernia repair or breast reconstruction. FIG. 1A is a perspective view. FIG. 1B is a magnified view of a corner of the matrix illustrated in FIG. 1A . FIG. 1C is a side view, showing the width and thickness of the matrix.
[0022] FIGS. 2A and 2B compare the three-dimensional braided matrix in a relaxed position ( FIG. 2A ), and in an expanded configuration when pulled in opposite directions along the vertical plane ( FIG. 2B ).
DETAILED DESCRIPTION OF THE INVENTION
I. Three-Dimensional Braided Matrix
[0023] The implantable devices are formed from a three-dimensional braided matrix (see FIG. 1A-C ). Suitable materials and methods for making the three-dimensional braided matrix are described in U.S. Publication No. 2011/0238179A1 to Laurencin, et al., the disclosure of which is incorporated herein in its entirety.
[0024] A polymeric fibrous structure that exhibits similar mechanical properties of human fibrous soft tissue is fabricated using standard 3-D braiding techniques. The mechanical properties of soft tissue and/or the fibrous structures can be determined by the placing a sample in a spring loaded clamp attached to the mechanical testing device and subjecting the sample to constant rate extension (5 mm/min) while measuring load and displacement and recording the resulting strain-stress curve.
[0025] In particularly useful embodiments, the polymeric braided structure exhibits a stiffness in the range of stiffness exhibited by fibrous soft tissue. Typically, suitable stiffness is in the range of about 10 to about 500 Newtons per millimeter (N/mm), and suitable tensile strength will be in the range of about 20 to about 1000 Newtons (N). In some embodiments, the stiffness of the polymeric fibrous structure will be in the range of about 20 to about 80 N/mm. The fibrous structure can be prepared using standard techniques for making a 3-D braided structure. The width and length dimensions of the device can vary within those ranges conventionally used for a specific application and delivery device. For example, dimensions of about 10 mm by 10 mm to about 100 mm by 100 mm. The device can be dimensioned to allow it to be roiled or otherwise folded to fit within a cannula having a small diameter to allow arthroscopic or laparoscopic implantation, fitting within openings on the order of about 0.5 mm to about 30 mm. In some embodiments, the fibrous structure defines openings on the order of about 0.5 mm to about 30 mm.
[0026] In certain embodiments, the fibrous structure is braided using multifilament PLLA fibers that are plied to create a yarn bundle. Each 60 to 100 denier PLLA fiber is made up of 20-40 individual filaments. In particularly useful embodiments, the 3-D braided fibrous structure includes about twenty four 75 denier PLLA fibers made up of 30 individual filaments. The diameter of a 75 denier PLLA fiber is about 80-100 microns, while the diameter of an individual filament is about 15-20 microns. In some embodiments, the fibers have a diameter ranging from about 50 microns to about 150 microns. In particularly useful embodiments, the fibers have a diameter ranging from about 80 microns to about 100 microns.
[0027] The three-dimensional braided matrix typically has a relaxed length ranging from about 10 mm to about 100 mm, a relaxed width ranging from about 10 mm to about 100 mm, and a relaxed thickness ranging from about 0.8 mm to 2 mm.
[0028] In one embodiment, the device is formed using a braiding mechanism with 75 denier degradable polymer such as PLLA, having a relaxed width of between 10 mm and 25 mm and tensioned width of between 8 mm and 20 mm; relaxed thickness of between 1.0 mm and 1.7 mm and a tensioned thickness of between 0.8 mm and 1.2 mm. In another embodiment, a two dimensional braid is made and then sewed or otherwise attached to additional strands or braid to form a three dimensional structure.
[0029] Suitable degradable polymers include polyhydroxy acids such as polylactic and polyglycolic acids and copolymers thereof, polyanhydrides, polyorthoesters, polyphosphazenes, polycaprolactones, biodegradable polyurethanes, polyanhydride-co-imides, polypropylene fumarates, polydiaxonane polycaprolactone, and polyhydroxyalkanoates such as poly4-hydroxy butyrate, and/or combinations of these. Natural biodegradable polymers such as proteins and polysaccharides, for example, extracellular matrix components, hyaluronic acids, alginates, collagen, fibrin, polysaccharide, celluloses, silk, or chitosan, may also be used
[0030] Preferred biodegradable polymers are lactic acid polymers such as poly(L-lactic acid) (PLLA), poly(lactic acid) (PLA), and poly(lactic-co-glycolic acid) (PLGA). The co-monomer (lactide-glycolide) ratios of the poly(lactic-co-glycolic acid) are preferably between 100:0 and 50:50. Most preferably, the co-monomer ratios are between 85:15 (PLGA 85:15) and 50:50 (PLGA 50:50). Blends of PLLA with PLGA, preferably PLGA 85:15 and PLGA 50:50 can also be used. The preferred polymer for the non-degradable region is a polyester and the preferred polymer for the degradable region is PLLA.
[0031] Material may be applied to the fibers to increase adhesion or biocompatibility, for example, extracellular matrix molecules such as flbronectin and laminin, growth factors such as EOF, FGF, PDGF, BMP, and VEGF, hyaluronic acid, collagens, and glycosaminoglycans.
[0032] The three-dimensional braided matrix has a very strong structure along the horizontal plane, such that the matrix has a high tensile strength and high suture anchor pull-through capabilities. Additionally, the matrix has high flexibility in the vertical plane, which allows improved placement, foundation and support during the surgical process and expansion as surrounding tissue moves. For example, when stretched along the vertical plane, the scaffold can increase by approximately 50% to approximately 100% in width; preferably the increase in width is greater than 60%, more preferably greater than 70%), most preferably greater than 80% in width. In contrast, when stretched along the horizontal plane, the scaffold only extends slightly, such as by approximately 10% to 20% of its initial length, preferably by approximately 15% to approximately 20% of its initial width. (See, FIGS. 2A and 2B ).
[0033] This flexibility is expected to allow for a more complete molding of the matrix to the intended features of the surgical site in which it is implanted and an enhanced healing and cell in-growth capability during the healing process. It also allows more flexibility to the surrounding tissue and comfort to the patient during the long-term healing and regeneration process, especially if tissue expands, such as in breast reconstruction procedures.
[0034] Optionally, the three-dimensional scaffold contains one or more bioactive or therapeutic agents, such as antibiotic drugs and/or pain relieving substances. The one or more active agents may be entrapped within the porous structure of the scaffold or incorporated through covalent or other chemical or physical bonding, in an active state or as precursors to be activated upon any physical or chemical stimuli or modification.
[0035] The devices can optionally be seeded with cells, preferably mammalian cells, more preferably human cells. Alternatively, they are implanted and cells may attach to and proliferate on and within the devices.
II. Methods of Manufacture
[0036] The three-dimensional braided scaffold can be prepared using standard techniques and modified equipment for making a 3-D braided structures. The device is 3-D braided so that the structure has the desired combination of the fiber properties and porosity resulting from the 3-D braided structure.
[0037] The geometric parameters which determine the shape and fiber architecture of three-dimensional braids includes braiding angle distribution, fiber volume fraction, number of carriers, and braiding width. The braiding pattern can depend on braiding machinery/technique used. The scaffold peak load strength range is from 20 to 1000 N, with an initial stiffness range of 20 to 500 N/mm.
[0038] Modified 3-D braiding equipment can produce braided materials that are approximately 60 inches long, but can be longer. Then the material is cut, typically with a hot knife to the desired length.
[0039] The width and length dimensions of the device can vary within those ranges conventionally used for a specific application. For example, dimensions of about 10 mm by 10 mm to about 100 mm by 100 mm. Typical lengths for the device range from 10 mm to 100 mm. Typical widths for the device range from 10 mm to 100 mm. The device can be dimensioned to allow it to be roiled or otherwise folded to fit within a cannula having a small diameter to allow arthroscopic or laparoscopic implantation, fitting within openings on the order of about 0.5 mm to about 30 mm.
[0040] 1. Breast Reconstruction
[0041] The scaffold used in breast reconstruction has a suitable size and shape for implantation into the submascular pocket of a patient's breast. Suitable lengths typically range from 10 mm to 100 mm. Suitable widths range from 10 mm to 100 mm.
[0042] Because the scaffold is a supple material it can be used to support the infra-mammary fold and the weight of an implant. In some embodiments, following implantation, the scaffold serves as an internal hammock, sling or brassiere to improve or maintain components of breast aesthetics, including the infra-mammary fold, ptosis and projection.
[0043] The scaffold may have any suitable shape, including rectangular and square. Alternatively, the scaffold may be in the shape of a curve cup, similar to the shape of a woman's brassiere. Optionally, the scaffold is provided in “cup” sizes and shapes that are standard for women's brassieres. Optionally, the scaffold contains one or more attached sutures, to facilitate insertion and fixation. These internal brassieres could be used to support, expanding breast tissue and breast implants, such as in breast reconstruction, or the breast tissue itself, such as in mastopexy cases without implants. In these embodiments, following implantation, the scaffold serves as an “internal bra”, hammock or sling to support a tissue expander, breast implant, or breast tissue.
[0044] The scaffold has multiple fixation points thus offering greater tissue fixation compared to sutures. The scaffold also serves as a scaffold for tissue ingrowth.
[0045] 2. Hernia Repair
[0046] The scaffold used in hernia repair has a suitable size and shape for implantation into the patient's abdomen. Suitable lengths typically range from 2 to 8 cm, but may be as long as up to approximately 12 cm, depending on the equipment used to braid the material. Suitable widths range from 2 to 8 cm, but may be as long as up to approximately 12 cm, depending on the equipment used to braid the material.
[0047] The scaffold may have any suitable shape, including sheets in the shape of a rectangular or square.
[0048] The braided structure can be packaged and sterilized in accordance with any of the techniques within the purview of those skilled in the art. The package in which the implant or plurality of implants are maintained in sterile condition until use can take a variety of forms known to the art. The packaging material itself can be bacteria and fluid or vapor impermeable, such as film, sheet, or tube, polyethylene, polypropylene, poly(vinylchloride), and poly(ethylene terephthalate), with seams, joints, and seals made by conventional techniques, such as, for example, heat sealing and adhesive bonding. Examples of heat sealing include sealing through use of heated rollers, sealing through use of heated bars, radio frequency sealing, and ultrasonic sealing. Peelable seals based on pressure sensitive adhesives may also be used. The scaffolds are typically provided in a sterile kit, such as a foil or TYVEX® package.
III. Methods of Use
[0049] The braided structures can be used to repair, support, and/or reconstruct fibrous soft issue. The braided structures may rapidly restore mechanical functionality to the fibrous soft tissue. The braided structures may be implanted using conventional surgical or laparoscopic/arthroscopic techniques. The braided structure can be affixed to the soft tissue or to bone adjacent to or associated with the soft tissue to be repaired. In particularly useful embodiments, the braided structure is affixed to muscle, bone, ligament, tendon, or fragments thereof. Affixing the braided structure can be achieved using techniques within the purview of those skilled in the art using, for example, sutures, staples and the like, with or without the use of appropriate anchors, pledgets, etc.
[0050] Use of the three-dimensional braided scaffold in breast reconstruction or hernia repair surgery may result in reduced scarring at the surgical site and in surrounding tissue.
[0051] A. Breast Reconstruction
[0052] After a mastectomy, a tissue expander is inserted beneath chest wall muscles, where it is positioned within a pocket of tissue. Because the expander and implant are surrounded by muscle, instead of being on top of muscle or only partly under muscle, the weight of the device should be well-supported. When an implant is not supported by muscle, it can slide down as gravity takes effect and tissues relax with age. The three-dimensional braided scaffold described above may be implanted to form an internal bra to prevent malposition of the tissue expander with time.
[0053] The placement of a tissue expander and implantation of the three-dimensional braided support material can be performed at the time of a mastectomy (immediate breast reconstruction) or at a later date (delayed breast reconstruction).
[0054] In some embodiments, the tissue expander is a temporary device that is expanded over time and later removed and replaced with a breast implant. Tissue expanders are saline-filled medical devices that are designed with an “access port” on the superficial surface of the device. This “access port” can be used to add saline to the device by inserting a needle into the patient's skin and into the device. This procedure is called “tissue expansion” and is performed in the office on a weekly basis post-operatively. The tissue expander is implanted to stretch breast skin and chest wall muscles in order to make way for a permanent breast implant. It is then typically removed at a second surgery and replaced with a breast implant.
[0055] In other embodiments, the tissue expander also serves as the breast implant, such as the Becker expander implant. When a Becker expander implant is used, a second operation to remove the expander and replace it with an implant is not required.
[0056] The three-dimensional braided scaffold can be attached in the required location by any suitable means. For example, when the pectoralis major muscle is detached interiorly, the three-dimensional braided scaffold may be sutured to the inferior edge of the muscle and fixated to the fascia at the level of the infra-mammary fold.
[0057] The three-dimensional braided material may also be implanted as part of a mastopexy procedure to correct the contour and/or elevation of a patient's breast(s) or prevent the breast(s) from sagging. In this procedure, the three-dimensional braided scaffold may be implanted in a suitable location to support the breast tissue. For example, the three-dimensional braided scaffold may be attached to serve as an “internal bra”, sling or hammock, by attaching it to the muscle edge. The inframammary fold may be elevated by suturing the three-dimensional braided scaffold to the underlying tissues at a higher level.
[0058] B. Hernia Repairs
[0059] The three-dimension braided scaffold may be used to reinforce soft tissue where a weakness in the tissue exists, such as in procedures involving the repair of hernias and abdominal wall defects, abdominal wall reinforcement and muscle flap reinforcement.
[0060] A number of different types of hernias can occur in the body, including congential diaphragmatic hernias (CDH), incisional hernias, inguinal hernias, hiatal hernias, and umbilical hernias. The most common site for a hernia is the groin.
[0061] Congential diaphragmatic hernias are birth defects that require surgery. Congenital diaphragmatic hernia (CDH) is the absence of the diaphragm, or a hole in the diaphragm. This can occur on either the left or right side, but is most common on the left.
[0062] Incisional hernias bulge through a scar. It happens when a weakness in the muscle of the abdomen allows the tissues of the abdomen to protrude through the muscle. An incisional hernia is typically small enough that only the peritoneum, or the lining of the abdominal cavity, pushes through. In severe cases, portions of organs may move through the hole in the muscle.
[0063] An inguinal hernia is a condition in which intra-abdominal fat or part of the small intestine, also called the small bowel, bulges through a weak area in the lower abdominal muscles. Inguinal hernias are the most commonly diagnosed types of hernia and are located in or around the groin area—the area between the abdomen and thigh.
[0064] Hiatal hernias are a small opening (hiatus) in the diaphragm that allows the upper part of the stomach to move up into the chest cavity. It causes heartburn from the gastric acid that flows back up from the stomach through the opening and into the esophagus.
[0065] Umbilical hernias are located around the belly button. Umbilical hernias are most common in infants, but they can a Heel adults as well. To prevent complications, umbilical hernias that do not disappear by age 4 or those that appear during adulthood may need surgical repair.
[0066] In hernia repair, the three-dimensional braided scaffold may be inserted to cover the area of the abdominal wall defect without sewing together the surrounding muscles by any suitable technique. This can be done under local or general anesthesia using a laparoscope or an open incision technique.
[0067] During a laparoscopic fundoplication, small (1 cm) incisions are made in the abdomen, through which instruments and a fiber optic camera are passed. The operation is performed using these small instruments while the surgeon watches the image on a video monitor. Laparoscopic fundoplication results in less pain and shorter hospitalization times than the open operation.
[0068] The trans-abdominal pre-peritoneal (TAPP) technique and the totally extra-peritoneal (TEP) technique are among the laparoscopic techniques typically used in hernia repair with other mesh materials and may be used with the three-dimensional braided scaffold. With the TAPP technique, the pre-peritoneal space is accessed from the abdominal cavity, and the implant is placed between the peritoneum and the transversalis fascia. With the TEP technique, the implant is again placed in the retroperitoneal space, but the space is accessed without violating the abdominal cavity.
[0069] An open and minimal invasive technique is the Lichtenstein hernia repair technique, in which the upper edge of an implant is attached to the outer side of the internal oblique and the lower edge of the mesh implant is attached to the aponeurotic tissue covering the pubis. Another open minimal invasive technique is the mesh-plug technique comprising attaching an implant, as described in the Lichtenstein technique, but also inserting a plug pushing the peritoneum in a direction towards the abdominal cavity.
[0070] The implant, inserted with any of the above described techniques, is used in order to support the regenerating tissue with minimal tension. It works by mechanical closure of the defect in the abdominal wall and by inducing a strong scar tissue around the mesh implant fibers.
[0071] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference.
[0072] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. | A braided, rather than woven, three-dimensional matrix has been developed to provide mechanical support in breast reconstruction or a mastopexy procedure. The braided three-dimensional matrix may be used to assist in hernia repair procedures. The matrix is a supple, strong, and flexible material, that can increase 50% to 100% in size when stretched along the vertical plane, but only extends by about 10% to 20% in length when stretched along the horizontal plane. Although the matrix is degradable, it provides sufficient mechanical and structural support for six to twelve months following implantation to allow for repair or growth of the breast tissue or the abdominal wall. The matrix is formed of three-dimensional braided multifilament polymeric fibers plied to create yarn bundles, and wherein the matrix comprises an inter-connected, open pore structure that enables even and random distribution and in-growth of cells. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of fabricating transparent conductive ITO films and, more particularly, to a method of fabricating transparent conductive ITO films used for electrodes of a liquid-crystal display or a solar cell by sputtering.
2. Description of the Related Art
As a transparent conductive film, a transparent conductive ITO film having In (indium) and O (oxygen) as basic constituent elements and having Sn (tin) added thereto as a donor has hitherto been known. This transparent conductive ITO film is fabricated by a chemical film formation process utilizing a chemical reaction, such as a spray process, a CVD process, a wet dipping process, or a physical film formation process utilizing a physical phenomenon in a vacuum such as a vacuum deposition process, or a sputtering process.
Of the above-described thin-film fabricating methods, the sputtering process is superior to the other film formation methods in that a transparent conductive ITO film having a relatively low resistivity can be obtained, and a transparent conductive ITO film having a uniform thickness can be formed on a relatively large substrate such as a glass plate.
For the sputtering process, a direct current (DC) discharge sputtering method and a radio frequency (RF) discharge sputtering method are available. At present, the direct current (DC) discharge method (called a DC sputtering process) is conventionally used among the sputtering processes because of its low cost, stable discharges, and easy control. For the sputtering process, a magnetron sputtering method is also available in which a plasma is converged on a surface of a target with a closed magnetic field produced by one or more magnets disposed behind the target. The magnetron sputtering method is also conventionally used among the sputtering processes because of its high-film deposition rate and therefore the magnetron sputtering method is available for mass production of integrated circuits. Based on the above, as a method of fabricating transparent conductive ITO films in mass production, a DC magnetron sputtering process in which a direct current discharge method and a magnetron method are combined is generally used at present. The DC magnetron sputtering process has recently been developed into a movable magnet mode in which the magnets disposed behind the target are reciprocated (oscillated) or eccentrically rotated to sputter the entire surface of the target.
In the sputtering process, in general, as main factors which exert an influence upon the resistivity of a transparent conductive ITO film, substrate temperature and an oxygen partial pressure are known. When the substrate temperature is increased, the resistivity of the film is decreased. When the oxygen partial pressure is decreased, a number of oxygen vacancies are produced within the film fabricated in that atmosphere. A film having a number of oxygen vacancies has a high carrier density, but, in contrast, the mobility of carriers is low. On the other hand, in the film fabricated in an atmosphere having a high oxygen partial pressure, the number of oxygen vacancies is small, and therefore the carrier density is low, but the mobility of carriers is high. Since the resistivity is proportional to the inverse of the product of the carrier density and the mobility of the carriers, there is a most appropriate oxygen partial pressure at which the resistivity becomes a minimum due to balance between the carrier density and the carrier mobility. Therefore, in the conventional sputtering process, the resistivity of a transparent conductive ITO film is decreased by adjusting each of the substrate temperature and the oxygen partial pressure as parameters.
In the fabrication of transparent conductive ITO films by using the above-described DC magnetron sputtering process, the deposition rate is usually approximately 100 nm/min. This deposition rate is affected by various factors, such as the spacing between the target and the substrate, and the density of the target (or the filling density). However, the deposition rate is mainly determined by the power applied to the target. In the case of an ordinary stationary magnet mode, the power to be applied to the target is about 1 to 2 W/cm 2 , determined by dividing the power to be applied to the target by the eroded area of the target. In the case of a movable magnet mode (oscillating motion or eccentric rotation), the power to be applied to the target is about 1 to 2 W/cm 2 , as determined represented by dividing the power to be applied to the target by the eroded area of the target formed when the magnet used in the movable magnet mode remains stationary.
The density of the target (the filling density) means the ratio of the actual target density to the theoretical density calculated from the crystalline structure of an oxide of indium (In 2 O 3 ). The value represented by dividing the power to be applied to the target by the eroded area of the target is called "power density". In the case of a movable magnet mode, the value represented by dividing the power to be applied to the target by the eroded area of the target formed when the movable magnet remains stationary is called "power density".
When transparent conductive ITO films are continuously fabricated by DC magnetron sputtering at a power density of about 1 to 2 W/cm 2 described above, the resistivity value of the transparent conductive ITO film is increased gradually with an increase in the number of times of the fabrication of the films (or the number of films deposited). Therefore, the resistivities of all the obtained transparent conductive ITO films are not the same. Consequently, there arises a problem that the resistivities of the transparent conductive ITO films, which are continuously fabricated by a DC magnetron sputtering process, increase as sputtering proceeds.
FIG. 3 shows a change in the resistivity of a film with respect to the cumulative power applied to a target when transparent conductive ITO films are continuously fabricated on a glass substrate by a DC magnetron sputtering process with the power density being set at 1.0 and 2.0 W/cm 2 . Here, the cumulative power means the number of times of the fabrication or the number of films deposited in the continuous fabrication of transparent conductive ITO films. The continuous fabrication of transparent conductive ITO films is performed in a single substrate processing mode in which a film is deposited on each substrate by one sputtering process by using a sintered target (density: 95%) having 10 wt. % of SnO 2 added to In 2 O 3 at a substrate temperature set at 200° C. and at a pressure of sputter gas of 0.4 Pa. The sputter gas is a mixture of Ar and O 2 gases, and the concentration of the O 2 gas in the sputter gas is adjusted in such a manner that the resistivity becomes a minimum every 3 kWh of the cumulative power. It can be seen from FIG. 3 that the resistivity at the power density of 2.0 W/cm 2 is smaller in the rate of the increase than at 1.0 W/cm 2 . However, the resistivity increases as the cumulative power increases for both of the power densities.
As shown in the above-described example, when the films are continuously fabricated by a magnetron sputtering process at a power density of about 1 to 2 W/cm 2 , the resistivities of all the transparent conductive ITO films fabricated are not in a desirable range. Conventionally, by mechanically shaving off the surface of the target before reaching the end of the target life, resistivity is kept within a predetermined range required to guarantee the performance of a device, such as a liquid-crystal display or a solar cell. Such redundant operations during the continuous fabrication cause problems, for example, a low productivity, or a high manufacturing cost.
FIG. 3 shows that the resistivity of the film increases as the cumulative power increases when transparent conductive ITO films are continuously fabricated. Such an increase of resistivity of the film with respect to the cumulative power, strictly speaking, occurs during film deposition on one substrate. That is, the resistivity of the film on one substrate increases along the thickness of the film. Therefore, in the case of depositing a film, to some extent a thick film, there arises a problem that the resistivity of the film, as a whole, increases as the film thickness increases.
It is an object of the present invention to solve the above-described problems. It is another object of the present invention to provide a method of fabricating transparent conductive ITO films having a low resistivity within a predetermined range until the end of the target life while continuously fabricating transparent conductive ITO films by magnetron sputtering. It is a further object of the present invention to provide a method of fabricating transparent conductive ITO films having a predetermined low resistivity even if the film thickness is great, while fabricating a transparent conductive ITO film on a single substrate.
It is a still further object of the present invention to provide a method of fabricating transparent conductive ITO films having a low resistivity from a view point of controlling the power density to be applied to the target. It is a still further object of the present invention to provide a method of fabricating transparent conductive ITO films capable of enhancing the efficiency of the target utilization and, as a result, enhancing the productivity of transparent conductive ITO films.
In accordance with a first aspect of the present invention, in a method of fabricating transparent conductive ITO films by a magnetron sputtering process, a sintered mixture of oxides of In and Sn being used as a target, the transparent conductive ITO film having In and O as basic constituent elements and added Sn as a donor, the method comprising a first step of depositing a transparent conductive ITO film on a substrate in an atmosphere produced by an inert gas and an oxygen gas, and a second step of removing, after the first step is stopped, a superficial oxygen-deficient layer of the target formed during the first step by means of electric discharge at a power density at which the rate at which the target is eroded is faster than the formation rate of the superficial oxygen-deficient layer, the first and second steps being alternately repeated.
In accordance with a second aspect of the present invention, the above-described power density is determined according to the density of the target in the first aspect of the present invention.
In accordance with a third aspect of the present invention, when the density of the target is 95% the power density is 2.5 W/cm 2 or more in the second aspect of the present invention.
In accordance with a fourth aspect of the present invention, when the density of the target is 70%, the power density is 4 W/cm 2 or more in the second aspect of the present invention.
In accordance with a fifth aspect of the present invention, the target is cooled by cooling means in the first aspect of the present invention.
In accordance with a sixth aspect of the present invention, in the first aspect of the present invention, when the resistivity of the transparent conductive ITO film has reached the limit of the resistivity required to guarantee the performance of the device in which the transparent conductive ITO film is used, the first step shifts to the second step, the second step is terminated after the superficial oxygen-deficient layer of the target is removed, the first step is started again, thereafter the first and second steps are alternately repeated in the same procedure.
In accordance with a seventh aspect of the present invention, a transparent conductive ITO film is continuously formed on each of a plurality of substrates in the first step, and thereafter a second step is performed in each of the above-described aspects of the present invention.
In accordance with an eighth aspect of the present invention, the first and second steps are alternately repeated on one substrate in each of the above-described aspects of the present invention.
In accordance with a ninth aspect of the present invention, a mixture of oxides of In and Sn is used as a target, a transparent conductive ITO film having In and O as basic constituent elements and added. Sn as a donor deposited in an atmosphere produced by an inert gas and an oxygen gas by a magnetron sputtering process, film deposition takes place at a power density at which a rate at which the target is eroded faster than the rate of formation of the superficial oxygen-deficient layer.
In accordance with a tenth aspect of the present invention, the power density is determined according to the density of the target in the ninth aspect of the present invention.
In accordance with an eleventh aspect of the present invention, when the density of the target is about 95%, the power density is from 2.5 W/cm 2 to less than 4 W/cm 2 in the tenth aspect of the present invention.
In accordance with a twelfth aspect of the present invention, when the density of the target is about 70%, the power density is 4 W/cm 2 or more in the tenth aspect of the present invention.
In accordance with a thirteenth aspect of the present invention, the target is cooled by cooling means in each of the above-described ninth to twelfth aspects of the present invention.
In the present invention, the rate relation condition that the rate at which the target is eroded is faster than the formation rate of a superficial oxygen-deficient layer is satisfied by controlling the power density. The superficial oxygen-deficient layer formed on the surface of the target is removed by the control of the power density according to the rate relation condition. The control of the power density makes it possible to prevent the oxygen concentration of the target superficial layer from decreasing as the fabrication of the transparent conductive ITO film proceeds. Therefore, the control of the power density makes it possible to prevent an increase of the resistivity of the film caused by the formation of the superficial oxygen-deficient layer of the target. Consequently, the control of the power density makes it possible to maintain the resistivity of the film fabricated by DC magnetron sputtering within a relatively low predetermined range even if (a) transparent conductive ITO films are continuously fabricated on each of a plurality of substrates, or (b) a transparent conductive ITO film having a fairly great thickness is fabricated on a single substrate. Furthermore, since the film may be fabricated efficiently up to the end of the target life by removing the superficial layer of the target, the control of the power density enhances the efficiency of the target utilization. In addition, since the superficial layer of the target is removed, redundant operations, such mechanically shaving off the surface of the target, or replacing the target, are not necessary. Thus, the control of the power density leads to improved productivity of transparent conductive ITO films.
With the power density being set at a value which satisfies the above-described rate relation condition, transparent conductive ITO films can be continuously fabricated on each of a plurality of substrates by DC magnetron sputtering. However, in the continuous fabrication of transparent conductive ITO films, it is possible to include a second step in which magnetron sputtering is performed at a power density which satisfies the above-described rate relation condition when the resistivity of the transparent conductive ITO film has reached an upper limit of resistivity required to guarantee the performance of a device in which the transparent conductive ITO film is used during the first step in which film deposition is performed at a power density which is most appropriate for film deposition. Furthermore, it is possible to alternately perform the first and second steps in the continuous fabrication of transparent conductive ITO films. In such continuous fabrication also, the superficial oxygen-deficient layer of the target formed during the continuous fabrication is removed in the second step. The removal of the superficial oxygen-deficient layer in the second step makes it possible to restore the surface of the target to the same state as its initial use in the next first step. Therefore, in the second step, the resistivity of the film which has increased gradually during the continuous fabrication is returned to the value obtainable in the initial use of the target.
The above and further objects, aspects and novel features of the invention will more fully appear from the following detailed description when read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only and are not intended to limit the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing a change in the resistivity of a transparent conductive ITO film with respect to the cumulative power, where the film is manufactured in accordance with a method of a first embodiment of the present invention;
FIG. 2 is a graph showing a change in the resistivity of the transparent conductive ITO film with respect to the cumulative power, where the film is manufactured in accordance with a method of a second embodiment of the present invention; and
FIG. 3 is a graph showing a change in the resistivity of the transparent conductive ITO film with respect to the cumulative power, where the film is manufactured in accordance with a conventional method.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
First, the basis on which a method of fabricating a transparent conductive ITO film is conceived in accordance with the present invention will be described.
For example, the DC magnetron sputtering process has the problem that resistivity increases as sputtering proceeds in the case where transparent conductive ITO films are continuously deposited on a plurality of substrates in a single substrate processing mode in which film deposition is performed on a single substrate by one sputtering process. This problem arises because the concentration of oxygen gradually decreases in the superficial layer of the target as the continuous sputtering proceeds. The gradual decrease of the concentration of oxygen in the superficial layer of the target results from the oxygen being released from the superficial layer of the target because of a rise in the surface temperature of the target due to ion bombardment during sputtering or because of oxygen-selective sputtering. Such a phenomenon produces a superficial oxygen-deficient layer. Further, because oxygen present inside the target diffuses into the superficial oxygen-deficient layer, this superficial oxygen-deficient layer spreads deep into the target as the sputtering proceeds.
The oxygen flux sputtered from the surface of the target contains an atomic oxygen flux. The atomic oxygen flux is more active than the molecular oxygen flux which is included in the sputter gas. The active atomic oxygen flux easily reacts with the surface of the growing ITO film, and further tends to accumulate at the lattice site of oxygen on the surface of the ITO film. Therefore, the atomic oxygen flux contributes to improving crystallinity of the film in comparison with molecular oxygen. The improved crystallinity film shows a low resistivity. Therefore, the greater the atomic oxygen flux sputtered from the target, the lower the resistivity of the film becomes. However, if there is a superficial oxygen-deficient layer in the target, the sputtered atomic oxygen flux is reduced.
In the of FIG. 3, film deposition is performed in such a way that the amount of O 2 gas introduced is adjusted so that the resistivity of the film becomes a minimum every constant increment (3 kWh) of the cumulative power (integrated power). As shown in FIG. 3, in spite of the adjustment of the amount of O 2 gas introduced, the resistivity of the film increases as the cumulative power increases in both cases where the power density is 1.0 W/cm 2 and 2.0 W/cm 2 . When film deposition is performed by such continuous sputtering, the adjustment of only the amount of O 2 gases introduced makes it impossible to return the resistivity of the film to the minimum value obtainable in the initial use of the target. This is due to the fact that, as described above, the atomic oxygen flux to be sputtered from the target is decreased because of the deficiency of oxygen in the target, i.e., the superficial oxygen-deficient layer.
In the conventional continuous fabrication by a sputtering process, as described above, an appropriate amount (usually several %) of O 2 gas is included in the sputter gas so that resistivity can become a minimum every constant increment of cumulative power. A part of the O 2 gas included in the sputter gas contributes to the oxidation of the surface of the target, and thus oxygen must have been compensated for the surface of the target. However, the conventional sputtering process, the introduction of an appropriate amount of O 2 gas cannot check an increase in the resistivity of the film with an increase of the cumulative power, as shown in FIG. 3. This is attributed to the fact that, for such an amount of introduction of O 2 gas, oxygen is released faster by oxygen-selective sputtering or by a rise in the surface temperature than the target is oxidized due to the oxygen molecules introduced. As a result, oxygen becomes deficient in the superficial layer of the target, and an oxygen-deficient layer is formed.
In the present invention, based on the above-described fact, the resistivity of a transparent conductive ITO film fabricated on a substrate is prevented from increasing by removing a superficial oxygen-deficient layer formed in the target or preventing the formation thereof. The removal or prevention of formation of the superficial oxygen-deficient layer is realized by setting the power density of sputtering discharge in such a way that the rate at which the target is eroded is faster than the formation rate of the oxygen-deficient layer at the surface of the target.
A first embodiment of the present invention will now be described. This first embodiment shows a basic concept of the present invention. FIG. 1 is the graph showing a change in the resistivity of a film with respect to the power applied to a target in the first embodiment.
In the first embodiment, transparent conductive ITO films are fabricated continuously by a DC magnetron sputtering process of a stationary magnet mode according to a single wafer processing mode. A target of a sintered mixture (density: 95%) having 10 wt. % of SnO 2 added to In 2 O 3 is used, a power density of 2.5 W/cm 2 is applied to the target, a transparent conductive ITO film is formed on a glass substrate heated to 200° C. by a heating device at a pressure 0.4 Pa of sputter gas, which is a mixture of Ar and O 2 gases. Throughout the continuous fabrication, the O 2 gas in the sputter gas is maintained at a concentration of 4%, at which the resistivity becomes a minimum in the initial period of the sputtering.
As can be seen from the graph of FIG. 1, the resistivity is nearly constant up to the end of the target life even if the cumulative power increases. That is, it is possible to obtain a transparent conductive ITO film having nearly the same resistivity even if films are deposited on a number of substrates in the continuous fabrication of transparent conductive ITO films by sputtering.
The numerical values of the various conditions in the above-described steps are only examples, and are not limited to these numerical values.
According to this embodiment, it is possible to fabricate transparent conductive ITO films having nearly the same low resistivity on a substrate by using a target of a sintered mixture with a density of 95% and by setting the density of power applied to the target at 2.5 W/cm 2 . It may be said that the power density at which the condition of "the rate at which the target is erosion by sputtering is faster than the formation rate of the oxygen-deficient layer" is satisfied is 2.5 W/cm 2 .
When the power density applied to the target is 2.5 W/cm 2 , the formation rate of the superficial oxygen-deficient layer of the target is estimated to be not more than 20 nm/sec in the target having a density of 95%. On the other hand, when the power density applied to the target is 2.5 W/cm 2 , the erosion rate at which the target having a density of 95% is eroded is about 20 nm/sec. Therefore, if the power density is set to be 2.5 W/cm 2 or more for the target having a density of 95% of this embodiment, the rate at which the target is eroded is faster than the formation rate of the superficial oxygen-deficient layer of the target during sputtering. Sputtering in which the power density is set at 2.5 W/cm 2 or more for the target having a density of 95% makes it possible to prevent the resistivity of the transparent conductive ITO film from increasing, as shown in FIG. 1, in the continuous fabrication of transparent conductive ITO films.
In a case where the density of the target is about 95%, the power density is 2.5 W/cm 2 or more, and the other film deposition conditions shown in the first embodiment are satisfied, it is possible to fabricate a transparent conductive ITO film having nearly the same resistivity on a substrate while removing an oxygen-deficient layer formed on the surface of the target. However, if the power density is 4 W/cm 2 or more, the target becomes likely to be broken due to the thermal expansion difference between the heated sputtering surface of the target and the cooled rear surface of the target. It is preferable that the power density be set at 2.5 W/cm 2 to less than 4 W/cm 2 in order to prevent this breakage.
A target having a density of less than 95% (hereinafter referred to as a "low-density target") has a thermal conductivity lower than that of the target having a density of 95% (hereinafter referred to as a "high-density target"). Since the low thermal conductivity causes the temperature of the surface of the target to rise further, the low thermal conductivity causes the rate at which oxygen is released from the surface of the target to increase. That is, the low thermal conductivity causes the rate at which the superficial oxygen-deficient layer of the target is formed to increase. Therefore, to make the etch rate by sputtering faster than the formation rate of the superficial oxygen-deficient layer, it is necessary to increase the power density in the low-density target to more than in the high-density target. For example, in the case of a low-density target having a density of 70%, the power density is required to be 4 W/cm 2 or more. However, the low-density target having a density of 70% will not be broken even if a power density of 4 W/cm 2 or more is applied to the low-density target since a great number of pores or gaps present inside the low-density target in comparison with a high-density target relax the thermal expansion difference with the rear surface of the target. In fact, when a power density of 4 W/cm 2 is applied to the low-density target having a density of 70%, the target is not broken up to the end of the target life, and a transparent conductive ITO film having nearly the same resistivity can be obtained.
As described above, the power density at which the condition of "the rate at which the target is eroded is faster than the formation rate of the oxygen-deficient layer" is satisfied depends upon the target density. In general, the power density increases with a decrease in the target density. In this way, the power density determined according to the target density so that the above-described rate relation is satisfied makes it possible to continuously fabricate transparent conductive ITO films having nearly the same low resistivity.
When the power density is increased to make the rate at which the target is eroded faster than the formation rate of the oxygen-deficient layer, the amount of heat supplied to the target increases. An increase in this amount of heat causes the temperature of the surface of the target to rise and therefore the diffusion rate (i.e., the formation rate of the oxygen-deficient layer) of oxygen to increase. The target is required to be sufficiently cooled to check the rise in the temperature of the surface of the target. To cool the target, it is preferable that a cooling device be disposed behind the target.
According to a method of fabricating transparent conductive ITO films in accordance with a second embodiment, (1) a first step of depositing transparent conductive ITO films on a glass substrate continuously in a single wafer processing mode by DC magnetron sputtering is performed at a power density of 1.5 W/cm 2 , (2) when the resistivity of the transparent conductive ITO film manufactured on the substrate has reached 3.7×10 -4 Ωcm, the first step shifts to a second step of removing the oxygen-deficient layer formed during the first step, (3) in the second step, DC magnetron discharge is performed for 30 minutes at a power density of 4.5 W/cm 2 , and the first and second steps are alternately performed with shift timing according to the above-described step (2) until the end of the target life. In this embodiment, according to a DC magnetron sputtering process with a stationary magnet mode, film deposition is performed on a glass substrate heated to 200° C. by using a target made of a sintered mixture (density: 95%) having 10 wt. % of SnO 2 added to In 2 O 3 at a pressure 0.4 Pa of a mixed gas of Ar and O 2 gases serving as a sputter gas. Up to the end of the target life, the O 2 gas in the sputter gas is kept at a constant concentration of 2%, at which the resistivity has become a minimum in the initial period of the sputtering.
FIG. 2 is a graph showing a change in the resistivity of the film with respect to the cumulative power in the second embodiment. The solid line 11 in FIG. 2 indicates a change in the resistivity of the film in the first step. The dotted line 12 in FIG. 2 indicates a return of the increased resistivity during the first step to its initial value after the second step is performed.
The numerical values of the various conditions for film deposition, such as power density, resistivity, or discharge time, in the above-described steps are only examples, and are not limited to these numerical values. The fabrication method of the second embodiment may be applicable to a case in which transparent conductive ITO films are continuously fabricated in a batch processing mode in which these films are deposited on a plurality of substrates.
According to the second embodiment, as shown in FIG. 2, the superficial oxygen-deficient layer of the target formed during the first step is eroded during the second step in which DC magnetron discharge is performed for 30 minutes at a power density of 4.5 W/cm 2 . In the second step, the resistivity of the film which has increased to 3.7×10 -4 Ωcm is returned to 2.4×10 -4 Ωcm, which is nearly the same as in the initial period. In the case where the first and second steps are repeatedly alternately performed in this manner, the resistivity of the transparent conductive ITO films continuously fabricated until the end of the target life is in the range of 2.4×10 -4 to 3.7×10 -4 Ωcm.
In the second embodiment, the resistivity is returned to its initial value in the second step performed for 30 minutes at a power density of 4.5 W/cm 2 . However, the power density in the second step may preferably be such that the rate at which the target is eroded is faster than the formation rate of the oxygen-deficient layer on the surface of the target. In the case of a target with a density of about 95%, the power density in the second step may preferably be 2.5 W/cm 2 or more, as shown in the first embodiment. However, the higher the power density in the second step becomes, the shorter the time required for the second step can be made.
If the resistivity of the film when the first step shifts to the second step is set to be small, since the oxygen-deficient layer formed during the first step is thin, the time required for the second step can be shortened.
Furthermore, if Ar gas is used as a sputter gas in the second step in place of a mixture of Ar and O 2 gases, since the rate at which the target is eroded becomes faster, the time required for the second step can be shortened even more.
In the second embodiment, the first step shifts to the second step when the resistivity of the film becomes 3.7×10 -4 Ωcm. The shift timing by which resistivity of the film is determined may be set by any desired parameter. For example, the shift timing may be set at a time when the resistivity of the film reaches the upper limit of resistivity required to guarantee the performance of a device (a liquid-crystal display or a solar cell) in which the transparent conductive ITO film is used. In another example, the timing at which the first step shifts to the second step may be determined on the basis of the elapsed time of the first step. Incidentally, the time required for the resistivity of the film to increase up to 3.7×10 -4 Ωcm in the first step in the second embodiment is about 10 hours. In the second embodiment, the first step may shift to the second step after 10 hours.
Although the above-described second embodiment describes a target having a high density of 95% as an example, when the density of the target is low, the power density in the second step in which the oxygen-deficient layer is etched must be increased more than that in this embodiment in the same manner as described in the first embodiment. For example, the power density must be 4 W/cm 2 or more for a target having a low density of 70%.
In a method of fabricating transparent conductive ITO films in accordance with a third embodiment, a first step of performing film deposition by sputtering and a second step of removing an oxygen-deficient layer on the surface of a target are repeatedly performed while a film is being deposited on a single substrate.
Conventionally, the resistivity of the film being manufactured increases along the thickness of the film. When the conventional example shown in FIG. 3 is taken into consideration, if the film to be manufactured is fairly thick, it can be easily estimated that the resistivity of the film increases along the thickness of the film from 2.4×10 -4 Ωcm to 3.7×10 -4 Ωcm, and further increases beyond that. A fairly thick film thus will have a high resistivity as a whole. In such a case, if a first step of performing film deposition by sputtering and a second step of removing an oxygen-deficient layer on the surface of the target are repeatedly performed, it is possible to check an increase in the resistivity even if the film thickness is increased fairly. The setting of the timing at which the first step shifts to the second step at a desired resistivity value makes it possible to manufacture a transparent conductive ITO film having a desired resistivity. As described above, a method of fabricating transparent conductive ITO films in accordance with the third embodiment is effective for a case in which a lower resistivity of the film or uniformity of the resistivity along the thickness of the film is desired.
Also in the movable magnet mode in which magnets disposed behind the target are oscillated or eccentrically rotated, the power density with respect to the rate relation between the erosion rate and the formation rate of the oxygen-deficient layer is essentially the same as for a stationary magnet mode. Even in the RF magnetron sputtering process, if a power density at which the above rate relation can be maintained is applied to the target, it is possible to check an increase in the resistivity of the transparent conductive ITO film formed on the substrate in the same way as in the DC magnetron sputtering process.
As is clear from the foregoing description, according to the present invention, the following advantageous effects are obtained.
According to the present invention, since film deposition is performed at a power density at which the rate at which the target is eroded is faster than the formation rate of the oxygen-deficient layer, the superficial oxygen-deficient layer of the target is not formed, and the concentration of oxygen in the target is not decreased. As a result, even if transparent conductive ITO films are continuously fabricated by a DC magnetron sputtering process, it is possible to check an increase in the resistivity as the sputtering proceeds. Thus, it is possible to obtain a transparent conductive ITO film having nearly the same low resistivity up to the end of the target life.
In the continuous fabrication of transparent conductive ITO films, by repeatedly performing a first step in which conventional film deposition takes place continuously at a power density most appropriate for film deposition, and a second step in which a superficial oxygen-deficient layer of a target formed during the first step is removed when the resistivity of the transparent conductive ITO film reaches a predetermined value, it is possible to check an increase in the resistivity as the sputtering proceeds. Also, by repeatedly alternately performing a first step in which film deposition is performed by sputtering, and a second step in which a superficial oxygen-deficient layer of a target is removed in a film being formed on a substrate, it is possible to check an increase in the resistivity along the thickness of the film. As a result, even if the film increases in thickness, it is possible to obtain a transparent conductive ITO film having a relatively low resistivity.
Many various embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in this specification. To the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims. The following claims are to be accorded the broadest interpretation, so as to encompass all such modifications, equivalent structures and functions. | A film having a low resistivity until the end of a sputtering target life is obtained when fabricating transparent conductive ITO films on a number of or a single substrate continuously by magnetron sputtering. A method of fabricating by magnetron sputtering transparent conductive ITO films having In and O as basic constituent elements and added Sn as a donor in an atmosphere comprising an inert gas and O 2 is provided in which a sintered mixture of oxides of In and Sn is used as a target. This method includes a first step of performing film deposition, and a second step of performing, after the first step is stopped, electric discharge at a power density at which the rate at which the target is eroded is faster than the formation rate of the superficial oxygen-deficient layer of the target in order to remove the superficial oxygen-deficient layer of the target formed in the first step. The first and second steps are alternately repeated. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is broadly concerned with compositions and methods for sorbing and/or destroying dangerous substances such as chemical and biological warfare agents and environmental pollutants in air, water, and soil. The methods of the invention are carried out by simply contacting the target substance with metal oxide nanoparticles coated with a coating material selected from the group consisting of oils, surfactants, waxes, silyls, polymers (both synthetic and natural), epoxy resins, and mixtures thereof.
[0003] 2. Description of the Prior Art
[0004] The extremely high surface reactivity of a variety of nanocrystalline inorganic oxides has been well documented (see e.g., U.S. Pat. Nos. 6,093,236, 6,057,488, 5,990,373, each incorporated by reference herein). These patents demonstrate their use as destructive absorbents for various toxic materials, including acid gases, air pollutants, and chemical and biological warfare agents. While there can be no doubt about the emerging popularity of nanoparticles as superadsorbents, one significant drawback for some is their sensitivity to air exposure that results in appreciable reactivity loss. For example, magnesium oxide nanoparticles typically undergo the following changes upon exposure to humid air (50-55% RH, room temperature, 24 hours):
[0005] weight gain of 45-60%;
[0006] large decrease in surface area (from 500-600 m 2 /g to 40-50 m 2 /g;
[0007] change in pore structure
[0008] pore diameter (from 35-91 Å to 107-319 Å);
[0009] pore volume (0.5-0.9 cc/g to 0.2-0.3 cc/g);
[0010] partial conversion to hydroxide as demonstrated by IR and XRD analyses (see FIGS. 1 and 2);
[0011] some carbonate formation as illustrated by IR analysis (see FIG. 1);
[0012] reduced reactivity towards paraoxon (see FIG. 3);
[0013] nanocrystalline magnesium oxide (0.2 g) adsorbs 9 μL of paraoxon in about 3 minutes;
[0014] humidified nanocrystalline magnesium oxide particles adsorb only 40-50% of this amount even after 20 hours.
[0015] Thus, there is a need for improved nanocrystalline metal oxide adsorbents which do not lose their adsorbent properties upon exposure to air. Furthermore, these adsorbents should have a coating material which tends to exclude air (water, carbon dioxide, etc.) while allowing the target compound to contact and penetrate the coating so that the target compound will contact the reactive nanoparticle metal oxide.
SUMMARY OF THE INVENTION
[0016] The present invention overcomes these problems and provides compositions and methods for destructively sorbing (e.g., adsorption, absorption, and chemisorption) and destroying biological and chemical agents. This is broadly accomplished through use of finely divided nanoscale metal oxide adsorbents which are at least partially coated with a coating material.
[0017] In more detail, the nanoscale adsorbents according to the invention are formed from metal oxides. Preferred metal oxides include those selected from the group consisting of MgO, SrO, BaO, CaO, TiO 2 , ZrO 2 , FeO, V 2 O 3 , V 2 O 5 , Mn 2 O 3 , Fe 2 O 3 , NiO, CuO, Al 2 O 3 , SiO 2 , ZnO, Ag 2 O, the corresponding hydroxides of the foregoing, and mixtures thereof. While conventionally prepared powders can be used in the methods of the invention, the preferred powders are prepared by aerogel techniques from Utamapanya et al., Chem. Mater., 3:175-181 (1991), incorporated by reference herein. The adsorbents prior to coating should have an average crystallite size (as is conventional in the art, the term “particle” is used herein interchangeably with the term “crystallite.”) of up to about 20 nm, preferably from about 2-10 nm, and more preferably 4 nm, and exhibit a Brunauer-Emmett-Teller (BET) multi-point surface area of at least about 15 m 2 /g, preferably at least about 80 m 2 /g, and more preferably from about 200-850 m 2 /g. In terms of pore radius, the preferred adsorbents should have an average pore diameter of at least about 20 Å, more preferably from about 30-100 Å, and most preferably from about 50-90 Å.
[0018] As mentioned above, the metal oxide particles are at least partially coated with a quantity of a coating material other than metal oxide coatings. As used herein, “coated” or “coating” is intended to refer to coatings which only physically coat the particles, as well as those coatings which modify or react with the metal oxide surfaces. Preferred coating materials include those selected from the group consisting of surfactants, oils, polymers (both synthetic and natural; e.g., silicone rubber and cellulose and its derivatives), resins, waxes, silyls, and mixtures thereof. The surfactant can be cationic, anionic, and/or nonionic, with preferred surfactants being those selected from the group consisting of N,N-dimethyl dodecyl amine, dioctyl sodium sulfosuccinate, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, nonylphenol polyethylene glycol ethers, C 10-14 alkyl ether phosphates, ethoxylated alcohols, propoxylated alcohols, alkyl amines, amine salts, ethoxylated amines, modified linear aliphatic polymers, and mixtures thereof.
[0019] Preferred oil coatings are mineral oils, silicone oils, fomblin oils, and vegetable oils, with mineral oils being particularly preferred. Furthermore, while any available wax is suitable as a coating in the inventive composition, preferred waxes are paraffin wax, carnauba wax, and polyethylene waxes. The nanoparticles can also be derivatized using silyl reagents. In this embodiment, the silyl will typically chemically modify the nanoparticle surface. Preferred silyl reagents have the general formula R n Si(R′) 4-n , where R is a C 1 -C 20 hydrocarbyl or functionalized hydrocarbyl group, R′ is a hydrolysable group such as a C 1 -C 3 alkoxy, a halide, an amino, or a carboxylate group, and n is 1, 2, or 3. Dimers and oligomers of this formula are also suitable. A particularly preferred silyl reagent is n-octyl trimethoxysilane.
[0020] The methods by which the inventive nanoparticles are formed depend upon the particular coating material utilized. In embodiments where the coating material is a surfactant, the compositions are formed by mixing the particular metal oxide nanoparticles and the desired surfactant(s) in the presence of a non-aqueous and aqueous solvent (e.g., hexane) for a time period of from about 2-24 hours. After mixing, the composition is preferably centrifuged and then dried at a temperature of from about 100-110° C. for a time period of from about 1-2 hours. Alternately, the materials can be prepared by a dry mixing process.
[0021] The quantities of the metal oxide nanoparticles and surfactants used should be such that the final metal oxide nanoparticle comprises at least about 2% by weight surfactant, more preferably from about 5-50% by weight surfactant, and most preferably from about 10-50% by weight surfactant, based upon the weight of the metal oxide nanoparticles taken as 100% by weight.
[0022] In embodiments where the nanoparticles are coated with oil, the composition is made by simply mixing the dry metal oxide particles with the particular oil. The respective quantities of metal oxide particles and oil should be selected so that the final composition comprises at least about 10% by weight oil, preferably from about 25-140% by weight oil, and more preferably 50-100% by weight oil, based upon the weight of the metal oxide nanoparticles taken as 100% by weight.
[0023] In embodiments where the nanoparticles are coated with a wax, the compositions are prepared by mixing the nanoparticles with the particular wax in the presence of heat (e.g., by mixing in a hot oil bath at temperatures of at least about 10° C. above the melting point of the particular wax or waxes). In this embodiment, the final composition should comprise at least about 10% by weight wax, preferably from about 25-100% by weight wax, and more preferably 50-75% by weight wax, based upon the weight of the metal oxide nanoparticles taken as 100% by weight.
[0024] In the embodiment where the metal oxides surfaces are modified with a silyl coupling agent, a solution is preferably prepared which includes the silyl, a small amount of acid (e.g., 4-8 drops of acetic acid), and an alcohol solution (e.g., ethanol, 95% aq.). The reaction mixture is stirred for about 3-7 minutes in order to allow hydrolysis and silanol formation. Then, the desired metal oxide nanoparticles are added to the solution followed by stirring for 10-20 minutes. The composition is preferably then centrifuged, washed with ethanol, dried at about 100-110° C. for about 25-35 minutes and kept in a desiccator under vacuum overnight. In this embodiment, the amount of silyl should be such that the final composition comprises at least about 2% by weight of the silyl compound, preferably from about 5-100% by weight of the silyl compound, and more preferably 25-50% by weight of the silyl compound, based upon the weight of the metal oxide nanoparticles taken as 100% by weight.
[0025] In the embodiment where the nanoparticles are incorporated into polymers or resins, the composites can be prepared by mixing the nanoparticles with either the polymer or resin precursors or the polymers and resins themselves. Both natural and synthetic polymers may be used in making the composites. Natural polymers include proteins, DNA, RNA, enzymes, carbohydrates and starches. Synthetic polymers include butadiene, styrene, copolymers of butadiene and sytrene, copolymers of styrene, acrylonitrile and methylmethacrylate, polyethyl acrylate, polyvinylchloride, polybutadiene-coacrylonitrile, acrylonitrile-butadiene-styrene, other copolymers, and simple polymers including cellulosics, silicon rubbers, polyolefins (such as polyethylene and polypropylene), nylons, rubbers, polyurethane, polyimides, rayon, polymethyl methacrylate, polyvinylidene chloride, polycarbonates, aramids, polyvinylpyrrolidone and polyesters. The precursors, polymers, or resins can be in the melt or liquid forms (either cast-formed or spin-formed), films, fibers, hollow fibers and other forms. As an example, silicone membranes containing nanoparticles can be prepared. Silicone rubber/elastomer is a particularly relevant material because it is highly permeable to particular chemical and biological agents as shown in Almquist et al., Journal of Membrane Science, 153 (1999) 57-69, incorporated by reference herein. Incorporating the nanoparticles into the silicone rubber/elastomer material permits a wide range of application means such as spraying, dipping, casting, extrusion, molding and other forming means.
[0026] Regardless of the embodiment, the coating process will result in a composite having an average overall crystallite size of up to about 25 nm, more preferably from about 2-20 nm, and most preferably from about 4-8 nm.
[0027] In another embodiment, the above-described coated nanoparticles can be formed into pellets for use when powder decontaminants are not feasible. These pellets are formed by pressing a quantity of one of these powdered (and coated) metal oxide composites at a pressure of from about 50-6,000 psi, more preferably from about 500-5,000 psi, and most preferably at about 2,000 psi. While pressures are typically applied to the powder by way of an automatic or hydraulic press, one skilled in the art will appreciate that the pellets can be formed by any pressure-applying means, including extrusion. Furthermore, a binder or filler can be mixed with the adsorbent powder, and the pellets can be formed by pressing the mixture by hand. Agglomerating or agglomerated as used hereinafter includes pressing together of the adsorbent powder as well as pressed-together adsorbent powder. Agglomerating also includes the spraying or pressing of the adsorbent powder (either alone or in a mixture) around a core material other than the adsorbent powder. Furthermore, another embodiment is the incorporation of the nanoparticles into films, fibers or coatings as shown in Malchesky et al., Trans. Am. Soc. Artif. Intern. Organs, Vol. XXIII (1977) 659-665, incorporated by reference herein.
[0028] In order to effectively carry out the methods of the invention, the pellets should retain at least about 25% of the multi-point surface area/unit mass of the coated metal oxide particles prior to pressing together thereof. More preferably, the multi-point surface area/unit mass of the pellets will be at least about 50%, and most preferably at least about 90% of the multi-point surface area/unit mass of the starting metal oxide particles prior to pressing. The pellets should retain at least about 25% of the total pore volume of the coated metal oxide particles prior to pressing thereof, more preferably, at least about 50%, and most preferably at least about 90% thereof. In the most preferred forms, the pellets will retain the above percentages of both the multi-point surface area/unit mass and the total pore volume. The pellets normally have a density of from about 0.2 to about 2.0 g/cm 3 , more preferably from about 0.3 to about 1.0 g/cm 3 , and most preferably from about 0.4 to about 0.7 g/cm 3 . The minimum surface-to-surface dimension of the pellets (e.g., diameter in the case of spherical or elongated pellet bodies) is at least about 1 mm, more preferably from about 10-20 mm.
[0029] In carrying out the methods of the invention, one or more of the above described metal oxide particle composites is contacted with the target substance to be sorbed, decontaminated or destroyed under conditions for sorbing, decontaminating or destroying at least a portion of the substance. The methods of the invention provide for destructively adsorbing a wide variety of chemical agents, including agents selected from the group consisting of acids, alcohols, compounds having an atom of P, S, N, Se, or Te, hydrocarbon compounds, and toxic metal compounds. The methods of the invention also provide for biocidally adsorbing a wide variety of biological agents, including spores, bacteria, fungi, viruses, rickettsiae, chlamydia, and toxins. Utilizing the metal oxide particulate composites in accordance with the methods of the invention is particularly useful for biocidally adsorbing biological agents such as spore-forming bacteria, especially gram positive bacteria like B. globigii and B. cereus. In another embodiment, the methods of the invention provide for the destructive adsorption of hydrocarbon compounds, both chlorinated and non-chlorinated.
[0030] The contacting step can take place over a wide range of temperatures and pressures. For example, the particulate metal oxide composites can be taken directly to a contaminated site and contacted with the contaminant and/or contaminated surfaces at ambient temperatures and pressures. Alternately, the contacting step can be carried out at a temperature of from about −70-700° C. If the contacting step is to be carried out under ambient temperatures, preferably the reaction temperature range is from about 15-50° C. If the contacting step is to be carried out under high temperature conditions, then preferably the temperature range for the reaction is from about 300-500° C.
[0031] If the contacting step is carried out under ambient conditions, the particulate metal oxide composites should be allowed to contact the target substance for at least about 2 minutes, preferably from about 60-1440 minutes, and more preferably from about 60-120 minutes. If the contacting step is carried out under high temperatures conditions, then the particulate metal oxide composites should be allowed to contact the target substance for at least about 2 seconds, preferably for about 5-20 seconds, and more preferably for about 8-10 seconds.
[0032] If the target substance is a biological agent, the contacting step results in at least about a 90% reduction in the viable units of the biological agent, preferably at least about a 95% reduction, and more preferably at least about a 99% reduction. If the target substance is a chemical agent, the contacting step results in at least about 50% reduction in the concentration of the chemical agent, preferably at least about a 75% reduction, and more preferably at least about a 90% reduction.
[0033] Those skilled in the art will appreciate the benefits provided by the methods of the invention. In accordance with the invention, military personnel can utilize the particulate metal oxides and composites thereof to neutralize highly toxic substances such as nerve agents and biological agents. These particles and composites can be utilized in their non-toxic ultrafine powder form to decontaminate areas exposed to these agents, or the highly pelletized composites can be utilized in air purification or water filtration devices. Other countermeasure and protective uses for the metal oxide particles and composites of the particles include personnel ventilation systems and wide-area surface decontamination. Furthermore, the metal oxide composites may remain airborne, thus providing effective airborne decontamination of chemical or biological agents. Alternately, the composites can be formulated into a cream or other skin applicators or incorporated into or on clothing in order to provide protection to personnel at risk of contacting a dangerous agent.
[0034] Unlike currently available decontamination methods, the methods of the invention utilize composites that are non-toxic to humans and non-corrosive to equipment, thus permitting the decontaminated equipment to be put back into use rather than discarded. Furthermore, because the composites are easy to disperse and readily transportable, and because little or no water or additive is required to practice the invention, it is relatively simple to destroy the contaminants at the contaminated site.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] [0035]FIG. 1 is a graph depicting an IR spectrum of magnesium oxide nanoparticles before and after humidity exposure;
[0036] [0036]FIG. 2 shows the XRD of magnesium oxide nanoparticles before and after humidity exposure;
[0037] [0037]FIG. 3 is a graph demonstrating the rate of adsorption of paraoxon by magnesium oxide nanoparticles before and after humidity exposure;
[0038] [0038]FIG. 4 demonstrates the rate of adsorption of paraoxon by magnesium oxide nanoparticles and surfactant-coated magnesium oxide nanoparticles before humidity exposure;
[0039] [0039]FIG. 5 shows two graphs depicting the rate of adsorption of paraoxon by magnesium oxide nanoparticles and surfactant-coated magnesium oxide nanoparticles after humidity exposure;
[0040] [0040]FIG. 6 depicts the rate of adsorption of paraoxon by magnesium oxide nanoparticles and double surfactant-coated magnesium oxide nanoparticles before and after humidity exposure;
[0041] [0041]FIG. 7 is a graph showing the weight gain, after humidity exposure, by magnesium oxide nanoparticles coated with mineral oil;
[0042] [0042]FIG. 8 shows the rate of adsorption of paraoxon by various mineral oil-coated magnesium oxide nanoparticles after humidity exposure;
[0043] [0043]FIG. 9 shows two graphs depicting 31 P NMR spectra of a magnesium oxide nanoparticles/paraoxon mixture both before and after humidity exposure;
[0044] [0044]FIG. 10 depicts two 31 P NMR spectra of a mixture of magnesium oxide nanoparticles coated with 50% by weight mineral oil and paraoxon, both before and after humidity exposure;
[0045] [0045]FIG. 11 is a graph showing the weight gain, after humidity exposure, by magnesium oxide nanoparticles coated with silicone oil;
[0046] [0046]FIG. 12 depicts the rate of adsorption of paraoxon by magnesium oxide nanoparticles and silicone oil-coated magnesium oxide nanoparticles before and after humidity exposure;
[0047] [0047]FIG. 13 is a graph showing the weight gain, after humidity exposure, by magnesium oxide nanoparticles coated with a modified silicone oil derivative (SAG 47);
[0048] [0048]FIG. 14 depicts the rate of adsorption, both before and after humidity exposure, of paraoxon by magnesium oxide nanoparticles and magnesium oxide nanoparticles coated with a modified silicone oil derivative (SAG 47);
[0049] [0049]FIG. 15 is a graph depicting a 31 P NMR spectrum after humidity exposure of a mixture of magnesium oxide nanoparticles coated with a modified silicone oil derivative (SAG 47) and of paraoxon after 20 hours;
[0050] [0050]FIG. 16 is a graph showing the weight gain, after humidity exposure, by magnesium oxide nanoparticles coated with paraffin wax;
[0051] [0051]FIG. 17 depicts the rate of paraoxon adsorption, both before and after humidity exposure, by magnesium oxide nanoparticles and magnesium oxide nanoparticles coated with paraffin wax;
[0052] [0052]FIG. 18 is a graph demonstrating the weight gain, after humidity exposure, by magnesium oxide nanoparticles coated with carnauba wax;
[0053] [0053]FIG. 19 depicts the rate of paraoxon adsorption, both before and after humidity exposure, by magnesium oxide nanoparticles and magnesium oxide nanoparticles coated with carnauba wax;
[0054] [0054]FIG. 20 shows the weight gain, after humidity exposure, by magnesium oxide nanoparticles coated with polyethylene wax;
[0055] [0055]FIG. 21 demonstrates the rate of paraoxon adsorption, both before and after humidity exposure, by magnesium oxide nanoparticles and magnesium oxide nanoparticles coated with polyethylene wax;
[0056] [0056]FIG. 22 is a graph showing the weight gain, after humidity exposure, by magnesium oxide nanoparticles coated or modified with a C 8 silyl;
[0057] [0057]FIG. 23 depicts the rate of paraoxon adsorption after humidity exposure by magnesium oxide nanoparticles and magnesium oxide nanoparticles coated or modified with a C 8 silyl; and
[0058] [0058]FIG. 24 depicts the rate of paraoxon adsorption after humidity exposure by magnesium oxide nanoparticles coated or modified with a C 8 silyl and then coated with mineral oil.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
EXAMPLES
[0059] The following examples set forth preferred methods in accordance with the invention. It is to be understood, however, that these examples are provided by way of illustration and nothing therein should be taken as a limitation upon the overall scope of the invention.
General Procedures
[0060] 1. Humidification of Samples
[0061] In each of the following examples, when a sample was subjected to humidity, this was accomplished by placing the particular sample in a humidity chamber for 24 hours at 50-55% relative humidity. The percent weight gain was calculated, and the humidified sample was analyzed by XRD and BET multi-point surface area analyses as described below.
Example 1
Magnesium Oxide Nanoparticles Coated with a Surfactant
[0062] 1. Preparation of Materials
[0063] Several 1 g samples of magnesium oxide nanoparticles were individually coated with from 1-20% by weight of a hydrocarbon-based surfactant. This was accomplished by adding the magnesium oxide nanoparticles and the desired surfactant to a 250 mL, stoppered Erlenmeyer flask equipped with a stir bar and containing 50 mL of hexanes. The reaction mixture was stirred for 20 hours followed by centrifuging and drying in an oven 110° C. for one hour. The resulting samples were characterized by BET and XRD. The BET multi-point surface area was determined using N 2 adsorption at liquid N 2 temperature to measure the surface area/unit mass. The BET surface area measurement techniques are described in Introduction to Powder Surface Area, Lowell, S., John Wiley & Sons: New York (1979), incorporated by reference herein. Table 1 sets forth the results of this analysis, along with the particular surfactants that were used.
TABLE 1 XRD SSA, m 2 /g before after before after Entry Surfactant Wt. % humidity humidity humidity humidity 1 None 0 oxide oxide + 586 29.8 hydroxide 2 DDA 1 oxide oxide + 477 31.3 (N,N-Dimethyl hydroxide 3 dodecyl amine) a - 3 oxide oxide + 475 34.6 Cationic surfactant hydroxide 4 5 oxide oxide + 426 24.6 hydroxide 5 10 oxide oxide+ 399 33.8 hydroxide 6 20 oxide oxide+ 361 34.5 hydroxide 7 AOT (Aerosol- 2 oxide oxide + 444 41.6 OT) b -Anionic hydroxide 8 surfactant 5 oxide oxide 415 47.1 9 10 oxide oxide 426 64.1 10 20 oxide oxide 378 71.3
[0064] These results show that the respective surface areas of the surfactant-treated magnesium oxide nanoparticles before humidification were generally less than those of the uncoated samples. Furthermore, the decreases in surface area in the BET data of all surfactant-treated magnesium oxide samples after humidity exposure were the same as the uncoated samples with the values after humidification being higher than the untreated humidified sample.
[0065] Table 2 summarizes the weight gain observed by various surfactant-coated magnesium oxide nanoparticles. This further suggests that there is some degree of protection offered by these surfactant coatings as demonstrated by the reduction in weight gain under humidifying conditions.
TABLE 2 Weight Gain Surfactant Surfactant Upon Humidity Entry Name Type Exposure % 1 none N/A 51 2 Triton X-114 a neutral 34 3 Surfynol 104A b neutral 35 4 Tergitol NP-4 c neutral 34 5 DeZOLINE T d cationic 33 6 DDA e cationic 41 7 Aerosol OT f anionic 30 8 Emphos PS-236 g anionic 36
[0066] 2. Paraoxon Adsorption Test
[0067] The surfactant-treated nanoparticles were tested for their ability to destructively adsorb paraoxon. In this procedure, 9 μL of paraoxon was added to a flask containing 200 mL of pentane followed by 0.2 g of the sample. The disappearance of the paraoxon was monitored using UV/Vis spectroscopy by taking scans for 60 minutes in 1 and 5 minute increments. The disappearance of paraoxon was plotted as a function of time. Paraoxon exhibits a distinct band around 265-270 nm, and a higher adsorbance reflected larger amounts of free, unadsorbed paraoxon. The surfactant-treated magnesium oxide nanoparticles showed high chemical reactivity with paraoxon (see FIG. 4). Thus, surfactant-treated magnesium oxide nanoparticles behaved very similar to the uncoated samples. However, the surfactant-coated, humidified samples where less reactive with paraoxon than uncoated, humidified magnesium oxide samples (see FIG. 5). Thus, the conclusion drawn was that the use of a surfactant coating did provide an advantage in that it reduced weight gain upon humidity exposure, but increased reactivity was not seen in these samples when allowed a paraoxon contact time of 1 hour.
[0068] In light of this data, further testing was carried out by preparing dry mixtures of magnesium oxide nanoparticles and surfactants using a solventless procedure. These samples were then tested for weight gain and paraoxon reactivity. These results showed that the surfactant Surfynol 104-A in weight ranges of 10-100 wt. % resulted in a 40-90% reduction in weight gain under standard humidifying conditions. Also, magnesium oxide nanoparticles containing 50 wt. % of this surfactant adsorbed paraoxon completely in about 20 hours.
Example 2
Magnesium Oxide Nanoparticles with Double Surfactant Coating
[0069] 1. Materials and Methods
[0070] This procedure was carried out to determine whether the use of a double surfactant coating would improve on the results obtained in Example 1 above. In this procedure, 1 g of magnesium oxide nanoparticles and the desired surfactant were added to a 250 mL, stoppered Erlenmeyer flask equipped with a stir bar and containing 50 mL of hexanes. The mixture was stirred for 20-24 hours after which a second surfactant was added followed by further stirring for another 20-24 hours. The reaction mixture was then centrifuged and dried in an oven at 110° C. for 1 hour. BET multi-point surface area and XRD measurements were taken of the resulting samples. These results are shown in Table 3.
TABLE 3 Weight gain upon SSA, m 2 /g XRD pattern humidity before after before after Entry Surfactant exposure % humidity humidity humidity humidity 1 AOT/DeZOLINE T nd a 323 60.0 oxide oxide 2 AOT/Surfynol 104A 26 330 80.9 oxide oxide 3 DeZOLINE T/AOT nd 308 60.7 oxide oxide 4 DeZOLINE 29 312 46.7 oxide oxide T/Surfynol 104A 5 Surfynol 104A/AOT 25 347 101 oxide oxide 6 Surfynol nd 288 86.8 oxide oxide 104A/DeZOLINE T
[0071] These results show that the use of a second surfactant resulted in a modest improvement in weight gain upon humidity exposure. Subsequent testing showed that the nanoparticles prepared in this example exhibited essentially the same paraoxon adsorption as the single surfactant coated samples of Example 1 (see FIG. 6).
Example 3
Magnesium Oxide Nanoparticles Coated with Oil
[0072] 1. Materials and Methods
[0073] In this procedure, respective samples of dry magnesium oxide particles (3.0 g) were mixed with 50% by weight of vegetable oil or mineral oil by mixing in a plastic cylindrical container. Mixing was carried out with a Dispermat mixer (about 600 rpm for about 1 minute, mixing with a spatula, then about 800 rpm for about 1 minute). The samples were then exposed to humidifying conditions following the procedure described above. The humidified samples were analyzed for weight gain as well as paraoxon reactivity (see Table 4).
TABLE 4 Weight gain upon humidity Humidity UV absorption reading Entry Additive exposure % exposure 0.5 h 2 h 20 h 1 None 67 No 0 0 0 Yes 1.78 1.65 1.31 2 Mineral Oil 38 No 0 0 0 Yes 0.33 0.16 0 3 Vegetable Oil 26 No 1.72 1.50 0.63 Yes 1.96 1.97 1.45
[0074] Both the vegetable oil and mineral oil resulted in an appreciable reduction in weight gain upon humidity exposure. While the vegetable oil-coated samples reacted poorly with paraoxon both before and after humidity exposure, the mineral oil-coated samples reacted with paraoxon similar to uncoated samples prior to humidity exposure. Furthermore, the mineral oil-coated samples reacted much faster than the uncoated or the vegetable oil-coated samples after humidity exposure.
[0075] 2. Varied Amounts of Mineral Oil Coating on Magnesium Oxide Nanoparticles
[0076] This procedure was carried out to determine how the amount of mineral oil affected the properties of the samples. Magnesium oxide nanoparticles were coated with mineral oil as described in Part 1 of this example, but by varying the quantity of mineral oil to achieve mineral oil percentages by weight of 25%, 50%, 100%, 120%, and 140%, with the weight of nanoparticles being taken as 100% by weight. The samples were then tested for air stability and paraoxon reactivity, with these results being shown in FIGS. 7 and 8. These results show that increasing the amounts of oil resulted in a smaller weight gain when exposed to humidifying conditions. Also, the mineral oil-coated samples (after humidity exposure) were found to be as reactive with paraoxon as the uncoated samples were before humidity exposure. Finally, all of the oil-coated samples were found to be more reactive than the uncoated, humidified sample (see FIG. 8).
[0077] [0077]FIGS. 9 and 10 illustrate 31 P NMR analyses of samples of both uncoated and coated magnesium oxide nanoparticles/paraoxon mixtures before and after humidity exposure. Paraoxon in deutero chloroform solvent exhibits a signal around δ-6.5 ppm, and the product derived via complete hydrolysis of paraoxon, the phosphate ion (PO 4 3− ), shows a signal around 0 ppm. Referring to FIG. 9, prior to humidity exposure the uncoated sample, appeared to react immediately with paraoxon and continued to react over the 20 hour analysis time. On the other hand, after humidity exposure the uncoated sample shows only the signal due to free paraoxon confirming that it has lost reactivity. Remarkably, the mineral oil (50 weight %) coated samples reacted essentially similar to the uncoated dry magnesium oxide nanoparticles (FIG. 10). This is true of the mineral oil coated samples both prior to and after humidity exposure. This clearly indicates that the mineral oil coating offers superior protection from humidity effects without reducing the reactivity of the nanoparticles.
[0078] Magnesium oxide nanoparticles coated with silicone oil and magnesium oxide particles coated with a modified silicone oil derivative (SAG 47, obtained from Crompton Corporation) were prepared following the procedure described in Part 1 of this example. FIGS. 11 and 12 set forth the data on the nanoparticles coated with silicone oil, while FIGS. 13 and 14 show the results for the nanoparticles coated with the modified silicone oil derivative. These results further confirm that long chain hydrocarbons (e.g., C 18 -C 24 ) and polydimethyl siloxanes
[0079] provide a barrier between the nanoparticle surface and its surroundings.
Example 4
Magnesium Oxide Nanoparticles Coated with Wax
[0080] In this procedure, magnesium oxide nanoparticles were coated with one of three different waxes: paraffin wax; carnauba wax; and a polyethylene-based wax derived via polymerization of ethylene. The particles were coated by mixing 2 g of magnesium oxide nanoparticles with the particular wax (10%, 25%, or 50% by weight, based upon the nanoparticles taken as 100% by weight) in a beaker with a spatula followed by placing the mixture in a hot oil bath (100-110° C. for the lower melting waxes and 145-150° C. for the higher melting waxes) for 5-7 minutes with stirring. These samples were then tested for their air stability and paraoxon reactivity, with these results being depicted in FIGS. 16 - 21 .
[0081] [0081]FIGS. 16 and 17 illustrate that paraffin wax provides a barrier of protection for the magnesium oxide particles. Furthermore, it can be seen that the 50 weight % coated samples were able to adsorb paraoxon completely, both before and after humidity exposure.
[0082] With respect to the carnauba wax, FIGS. 18 and 19 illustrate that increasing the amount of wax correspondingly increased protection against air exposure and resulted in lower weight gain upon humidifying. Furthermore, both samples coated with 50 weight % carnauba wax reacted comparably and completely with paraoxon both before and after humidity exposure.
[0083] [0083]FIGS. 20 and 21 show that the polyethylene wax also provided a barrier of protection from humidity for the magnesium oxide nanoparticles. Both the 25 and 50 weight % coated samples were able to absorb paraoxon completely, before as well as after humidity exposure. Thus, this concluded that a wide variety of waxes would be suitable coating materials for magnesium oxide nanoparticles.
Example 5
[0084] 1. Magnesium Oxide Nanoparticles Modified by Silyl Reagents
[0085] Magnesium oxide nanoparticle surfaces were chemically modified with a silane coupling reagent. This was accomplished by placing 100 mL of 95% aqueous ethanol solution, 6 drops of acetic acid, and the desired amount of n-octyl trimethoxysilane in a stoppered Erlenmeyer flask. The amounts of n-octyl trimethoxysilane were varied from 2-100% by weight, based upon the weight of magnesium oxide nanoparticles used. After stirring this reaction mixture for 5 minutes in order to allow hydrolysis and silanol formation, 2 g of magnesium oxide nanoparticles were added followed by more stirring for 15 minutes. The mixture was then centrifuged, washed with ethanol (2 times with 25 mL portions), and dried at 110° C. for 30 minutes. These samples were then tested for air stability and paraoxon reactivity. These results are shown in FIGS. 22 - 23 .
[0086] These results show that the silylated samples had paraoxon reactivity similar to that of the original magnesium oxide nanoparticles before humidity exposure (data not shown). Thus, it was concluded that surface silylation did not alter the magnesium oxide reactivity. Furthermore, there was an appreciable reduction in weight gain when silylated magnesium oxide nanoparticles were exposed to humidifying conditions as compared to the untreated samples (see FIG. 22). Thus, it appears that the C 8 organic group did provide a hydrophobic coverage of the surface of the nanoparticles. It was noted that the weight gain after humidity exposure was not appreciably affected by the amount of the silyl agent used. Referring to FIGS. 22 and 23, the lowest weight gain and good paraoxon adsorption were seen with the 25 weight % silylated sample. Further testing showed that similar results were achieved when changing the length of the alkyl group or the number of alkyl groups on the silicon.
[0087] 2. Magnesium Oxide Nanoparticles Modified by Silyl Reagents and Coated with Mineral Oil
[0088] Magnesium oxide nanoparticles were modified by n-octyl trimethoxysilane using a dry procedure wherein 3 g of the magnesium oxide nanoparticles where mixed with 0.75 g of n-octyl trimethoxysilane in a plastic cylindrical container. Mixing was carried out with a Dispermat mixer (approximately 600 rpm for 1 minute), followed by mixing with a spatula, and further mixing with the Dispermat mixer (approximately 800 rpm for 1 minute). The resultant sample was cured at 100° C. for half an hour. Samples of the modified nanoparticles were then coated with 10% by weight and 25% by weight, respectively, of mineral oil. As shown in FIG. 24, the use of both the silyl reagent and mineral oil resulted in an appreciable improvement in the rate of paraoxon adsorption of these samples after humidity exposure.
Example 6
Magnesium Oxide Nanoparticles Embedded in Silicone Rubber/Elastomer Membranes
[0089] This procedure was carried out to establish the feasibility of preparing nanoparticles containing silicone membranes, and to explore the capability of this embodiment to adsorb paraoxon. In this procedure, 0.4 g of magnesium oxide nanoparticles were mixed with approximately 3 g of a commercially available, room temperature-curing silicone (GE silicone II 100% silicone sealant, clear). The resulting mixture was cast quickly onto 3-4 microscope slides (25×75×1 mm). Curing was carried out by exposing the slides to air under ambient conditions (45-54% RH, 18-21° C, 24 hours). The resultant membranes were peelable, flexible, soft and appeared to contain a homogenous dispersion of the nanoparticles. Membranes containing both mineral oil coated nanoparticles and uncoated nanoparticles were prepared by this procedure. The membranes containing mineral oil coated nanoparticles were thinner and more transparent than the ones containing uncoated nanoparticles.
[0090] Table 5 summarizes the results of paraoxon (4.5 μL) adsorption with various membrane samples in 100 mL of pentane solvent. As seen in the control experiment (Entry 1), the silicone membrane by itself does not adsorb paraoxon while membranes containing nanoparticles adsorb paraoxon gradually over a period of 28 hours. Humidity exposure appeared to slow down the paraoxon adsorption as shown by comparing Entry 4 to Entries 2 and 3, and Entry 7 to Entries 5 and 6, respectively. In contrast, mineral oil coated samples appear to adsorb paraoxon more rapidly and completely both before and after humidity exposure.
TABLE 5 Wt. of Wt. of AP- Paraoxon adsorbed e , % Entry membrane, g MgO, g ½ h 2 h 20 h 28 h 1 a 0.3929 0 0 0 0 0 2 b 0.4037 0.09 36 48 75 79 (88) 3 0.3144 0.07 22 33 57 60 (86) 4 0.5352 0.12 13 24 49 54 (45) 5 c 0.6424 0.09 28 45 81 87 (97) 6 0.7049 0.09 31 53 88 92 (102) 7 0.5076 0.07 10 19 43 47 (67) 8 d 0.7777 0.09 42 68 94 97 (108) 9 0.5998 0.07 37 58 90 97 (139) 10 0.4856 0.06 24 36 60 64 (107) | Compositions and methods for destroying chemical and biological agents such as toxins and bacteria are provided wherein the substance to be destroyed is contacted with finely divided metal oxide nanoparticles. The metal oxide nanoparticles are coated with a material selected from the group consisting of surfactants, waxes, oils, silyls, synthetic and natural polymers, resins, and mixtures thereof. The coatings are selected for their tendency to exclude water while not excluding the target compound or adsorbates. The desired metal oxide nanoparticles can be pressed into pellets for use when a powder is not feasible. Preferred metal oxides for the methods include MgO, SrO, BaO, CaO, TiO 2 , ZrO 2 , FeO, V 2 O 3 , V 2 O 5 , Mn 2 O 3 , Fe 2 O 3 , NiO, CuO, Al 2 O 3 , SiO 2 , ZnO, Ag 2 O, the corresponding hydroxides of the foregoing, and mixtures thereof. | 8 |
BACKGROUND OF THE INVENTION
To produce dyed yarns, the so-called prefabrics have been knitted by the manipulation of a single yarn into knitted form variously colored and then unraveled to provide a single yarn with intermittent coloring or splotches as shown in U.S. Pat. No. 3,012,303 dated Dec. 12, 1961. In another process, continuous yarn is leased in a narrow fabric form and has been treated as disclosed in U.S. Pat. No. 3,605,225. In this patent, the warp yarns are heavier or of greater diameter than the filling yarns.
SUMMARY OF THE INVENTION
This invention utilizes the weaving of a plurality of relatively small diameter warp yarns into a fabric by the insertion of a relatively large diameter filling yarn in the warp yarns in such a relation that the filling may be easily unraveled or unwoven and further the yarns may be loosely woven or the filling yarn may be varied as to the picks per inch or its diametrical size depending upon the desired result. The fabric so formed may be heat treated to bulk it and to set the bulk or to color it either by a solid color or by stripes or splotches after which unraveling takes place to remove the treated filling from the warp and provide a yarn for reworking into various forms such as a fabric where bulking dyed or mottled colors or both of them are desired.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view illustrating the various steps which are performed upon the yarns which are the subject of this invention;
FIG. 2 is a detail plan on a greatly enlarged scale illustrating the weaving relation of the filling and warp yarns so that the filling yarn may be easily withdrawn by pulling upon it to remove it from the warp yarns;
FIG. 3 is a perspective view illustrating the intermittent coloring of the fabric formed;
FIG. 4 is a top plan view on an enlarged scale showing the removing of the filling yarn from the warp yarns which are spread in separated relation for takeup on a beam; and
FIG. 5 is a sectional view taken warpwise of the fabric.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, 10 designates generally a supply of warp yarns from various warp beams. 11 designates the station of weaving these warp yarns by inserting a filling therein in a particular relation to be described so as to provide a fabric 12 which issues from this weaving station. If desired, the fabric is wound and is then unwound and passed to the coloring station 13 wherein a dye is applied to the fabric 12 as it passes therethrough. The fabric now designated 12' may again be wound or otherwise held and is then passed into a bulking station 14 where heat is applied to relax or bulk the yarn particularly the untensioned filling yarn and set the bulk in the filling yarns while in their weaving relation with the warp yarns which, becuase of their size, can be thought of as threads. The fabric now at 12" is moved into a station 15 where the filling yarn is removed for reworking and then the warp yarns are packaged as at 16 for reuse as desired.
At the weaving station 11 the plurality of warp yarns 20 (diagrammatic showing FIG. 2 in a greatly reduced number of warp ends) are shown in the greatly enlarged relation in FIG. 2 where they are separated sufficiently so that the relationship of the filling yarn 21 may be observed. The insertion of the relatively large diameter filling yarns 21 is shown as by means of a double pick needle loom where pick goes acorss the width of the fabric and back before the shed changes. In this manner the filling is laid in with little or no tension and such tension as exists in the fabric is carried by the warp yarns. This is highly desirable for bulking of the filling yarns.
The filling yarns 21 are inserted so as to be substantially in contact with each other across the width of the woven fabric. The number of filling threads per inch of warp length of the fabric will be determined by the diameter of the filling yarn. Thus if the diameter of the filling yarn is one tenth of an inch (0.1 inch) (0.25 cm) there will be approximately 10 filling picks or yarns per inch of length of the warp yarns, (4 picks per cm) bulking of the filling varying this figure. It will be obvious that many weave constructions may be used, the one up one down illustrated in FIG. 2 being purely exemplary, other selected fabric constructions being usable.
After the insertion of the filling threads 21, the fabric now designated 25 (FIG. 2) is passed through one or a plurality of printing or padding stations, one of which is shown. Each may apply its own color to the fabric. A part of a Vigoureux printer is illustrated in FIG. 3 which includes a dye trough 26, a first lower partly immersed dye pick-up roller 27, a second upper pick-up and application roller 28, and a printing roller 29, the latter being on the upper side of the fabric 25. The lower roller 27 picks up dye from the trough 26, transferring it to the upper pick-up roller 28. The printing roller 29 has a plurality of raised portions 30 thereon, and as these press the fabric into engagement with the roller 28, the dye will be applied at the locations where this pressure of the raised portion 30 occurs, thus forming a plurality of stripes 31, in the showing here, across on the fabric 25 as it passes thru this printer or padder. At other stations similar to this, different colors may be applied.
After this coloring, when the warp threads are in a wavy form, it is passed into a station 14 where heat and pressure are applied. This will drive the dye into the fabric and particularly the filling yarns thereof, while at the same time if the fabric is loosely woven it will permit relaxation of the yarns causing them to increase in diameter or bulk. Also the heat will assist in bulking the yarn.
The next station 15 is where the filling yarn 21 is removed from the warp threads 20 as shown at FIG. 4 and this may be done by unraveling the filling yarns 21 from the warp threads by pulling upon it with any suitable means and a take-up, thus leaving the warp threads 20 in a separated relation to be packaged for reuse if desired.
By leasing warp yarns, bulking of the filling yarns is facilitated and a very close control may be had of the application of the color to the filling yarns. Further a plurality of yarns are provided which, from the process employed, may be of endless length depending upon the supply on the warp beam. Further there is really no theoretical limit to the length of filling yarn which may be operated upon at the same time. Practically the only limit is the width of the machine which weaves the filling yarn into the warp threads. The process is far more precise than may be had by a knitting-deknitting method such as disclosed in the above "Background of the Invention" and more bulking of the filling yarns may be provided. | The method of treating large diameter yarns by leasing a plurality of large diameter filling yarns into a woven fabric form of a type where the warp yarns are relatively small, and in which the filling yarn may be easily unwoven, treating the filling yarn either by means of a color, or bulking, or both of them and then unweaving the woven fabric to provide a treated yarn for reworking into various forms such as fabrics and carpets and the like. | 3 |
FIELD OF THE INVENTION
This invention relates to the use of onium aldehydes and ketones and derivatives thereof for coloring keratin-containing fibers, more particularly human hair, to a composition containing onium aldehydes and ketones for coloring keratin-containing fibers and to a process for coloring keratin-containing fibers.
BACKGROUND OF THE INVENTION
In general, keratin-containing fibers, for example hair, wool or pelts, are dyed either with substantive dyes or with oxidation dyes which are formed by oxidative coupling of one or more primary intermediates with one another or with one or more secondary intermediates. Primary and secondary intermediates are also known as oxidation dye precursors.
The primary intermediates normally used are primary aromatic amines containing another free or substituted hydroxy or amino group in the para or ortho position, diaminopyridine derivatives, heterocyclic hydrazones, 4-aminopyrazolone derivatives and 2,4,5,6-tetraaminopyrimidine and derivatives thereof.
Special representatives are, for example, p-phenylenediamine, p-toluylenediamine, 2,4,5,6-tetraaminopyrimidine, p-aminophenol, N,N-bis-(2-hydroxyethyl)-p-phenylenediamine, 2-(2,5-diaminophenyl)-ethanol, 2-(2,5-diaminophenoxy)-ethanol, 1-phenyl-3-carboxyamido-4-amino-5-pyrazolone, 4-amino-3-methylphenol, 2-aminomethyl-4-aminophenol, 2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine, 2,5,6-triamino-4-hydroxypyrimidine and 1,3-N,N′-bis-(2′-hydroxyethyl)-N,N′-bis-(4′-aminophenyl)-diaminopropan-2-ol.
The secondary intermediates used are generally m-phenylene-diamine derivatives, naphthols, resorcinol and resorcinol derivatives and m-aminophenol derivatives. Particularly suitable secondary intermediates are 1-naphthol, 1,5-, 2,7- and 1,7-dihydroxynaphthalene, 5-amino-2-methylphenol, m-aminophenol, resorcinol, resorcinol monomethyl ether, m-phenylenediamine, 1-phenyl-3-methyl-5-pyrazolone, 2,4-dichloro-3-aminophenol, 1,3-bis-(2,4-diaminophenoxy)-propane, 2-chlororesorcinol, 4-chlororesorcinol, 2-chloro-6-methyl-3-aminophenol, 2-amino-3-hydroxy-pyridine, 2-methyl resorcinol, 5-methyl resorcinol and 2-methyl4-chloro-5-aminophenol.
With regard to the dyes suitable for use in the hair coloring and tinting formulations according to the invention, reference is also specifically made to Ch. Zviak's work The Science of Hair Care, Chapter 7 (pages 248-250; Substantive Dyes) and Chapter 8, pages 264-267; Oxidation Dye Precursors), published as Vol. 7 of the Series “Dermatology” (Editors: Ch. Culnan and H. Maibach), Marcel Dekker Inc., New York/Basel, 1986 and to the “Europäische Inventar der Kosmetik-Rohstoffe” published by the Europäische Gemeinschaft and available in diskette form from the Bundesverband Deutscher Industrie- und Handelsuntemehmen für Arzneimittel, Reformwaren und Körperpflegemittel e.V., Mannheim, Germany.
Although intensive colors with good fastness properties can be obtained with oxidation dyes, the color is generally developed under the influence of oxidizing agents, such as H 2 O 2 for example, which in some cases can result in damage to the fibers. In addition, some oxidation dye precursors or certain mixtures of oxidation dye precursors can occasionally have a sensitizing effect in people with sensitive skin. Although substantive dyes are applied under more moderate conditions, their disadvantage is that, in many cases, the colors obtained have inadequate fastness properties.
The problem addressed by the present invention was to provide colorants for keratin fibers, more especially human hair, which would be at least equivalent in quality to conventional oxidation hair dyes in regard to depth of color, grey coverage and fastness properties, but which would not necessarily have to contain oxidizing agents, such as H 2 O 2 for example. Another problem addressed by the invention was to provide colorants with which a wide range of color tones could be obtained without any staining of the skin. In addition, the colorants according to the invention would have very little, if any, sensitizing potential.
It has now surprisingly been found that a combination of onium aldehydes and ketones as defined hereinafter and amines, hydroxy compounds and CH-active compounds are eminently suitable for coloring keratin-containing fibers. They give colors with excellent brilliance and depth of color and lead to a wide variety of color tones. The use of oxidizing agents is not necessary but, in principle, is not ruled out either.
Accordingly, the present invention relates to the use of onium aldehydes and ketones corresponding to formula I below or derivatives thereof:
BRIEF DESCRIPTION OF THE INVENTION
in which
R 1 is a hydrogen atom, a (C 1-4 ) alkyl group, an aryl group or a heteroaryl group,
R 2 , R 3 and R 4 independently of one another represent a hydrogen atom, a halogen atom, a (C 1-4 ) alkyl group, a (C 1-4 ) alkoxy group hydroxy-(C 1-4 )-alkoxy group, hydroxy group, nitro group, aryl group, trifluoromethyl group, amino group which may be substituted by (C 1-4 ) alkyl groups or a (C 1-4 ) acyl group; two of the substituents together may also form a fused benzene ring,
R 5 is a (C 1-4 ) alkyl group, aryl group, aralkyl group or heteroaryl group,
X is a direct bond or a vinylene or phenylene group which may be substituted and
Y − is halide, benzenesulfonate, p-toluene sulfonate, methane sulfonate, trifluoromethane sulfonate, perchlorate, sulfate, hydrogen sulfate or tetrachlorozincate or the N-oxide of the heterocycle,
in combination with at least one compound containing a primary or secondary amino group or hydroxy group selected from primary or secondary aliphatic or aromatic amines, nitrogen-containing heterocyclic compounds, α- to ω-amino acids, oligopeptides made up of 2 to 9 amino acids and aromatic hydroxy compounds and/or at least one CH-active compound, for coloring keratin-containing fibers.
The present invention also relates to a composition for coloring keratin-containing fibers, more particularly human hair, characterized in that it contains
(A) one or more onium aldehydes or ketones corresponding to formula I or derivatives thereof and
(B) at least one compound containing a primary or secondary amino group or hydroxy group selected from primary or secondary aliphatic or aromatic amines, nitrogen containing heterocyclic compounds, α- to ω-amino acids, oligopeptides made up of 2 to 9 amino acids and aromatic hydroxy compounds and/or at least one CH-active compound; the reaction product of components A and B may also be present.
DETAILED DESCRIPTION OF THE INVENTION
In the contexts of the invention, keratin-containing fibers are understood to include wool, pelts, feathers and, in particular, human hair. In principle, however, the colorants according to the invention may also be used to color other natural fibers such as, for example, cotton, jute, sisal, linen or silk, modified natural fibers such as, for example, regenerated cellulose, nitro, alkyl or hydroxyalkyl or acetyl cellulose and synthetic fibers such as, for example, polyamide, polyacrylonitrile, polyurethane and polyester fibers.
The scope of the present invention also encompasses the use of substances which are reaction products of the individual components with one another.
Examples of derivatives of the compounds corresponding to formula I are oximes, acetals, ketals or hydrazones.
Suitable compounds corresponding to formula I which may be used as component A are the benzenesulfonates, p-toluene sulfonates, methane sulfonates, trifluoromethane sulfonates, perchlorates, sulfates, chlorides, bromides, iodides and/or tetrachlorozincates of 4-formyl-1-methyl pyridinium, 3-formyl-1-methyl pyridinium, 2-formyl-1-methyl pyridinium, 4-formyl-1-ethyl pyridinium, 2-formyl-1-ethyl pyridinium, 4-formyl-1-benzyl pyridinium, 2-formyl-1-benzyl pyridinium, 4-formyl-1,2-dimethyl pyridinium, 4-formyl-1,3-dimethyl pyridinium, 4-formyl-1-methyl quinolinium, 2-formyl-1-methyl quinolinium, 4-(2-formylvinyl)-1-methyl quinolinium, 4-acetyl-1-methyl pyridinium, 2-acetyl-1-methyl pyridinium, 4-acetyl-1-quinolinium, 4-acetyl-1-methyl quinolinium and 4-(2-formylvinyl)-1-methyl pyridinium, 2,6-dichloro-4-formyl-1-methyl pyridinium, 2,6-diphenyl4-formyl-1-methyl pyridinium, 4-benzoyl-1-methyl pyridinium, 4-propionyl-1-methyl pyridinium, 2-oximomethyl-1-methyl pyridinium, 4-pyridine carboxaldehyde-N-oxide and N-methyl pyridoxal.
The compounds corresponding to formula I used in accordance with the invention are known from the literature and are commercially obtainable or may be prepared in known manner from the N-heterocyclic carbonyl compound and an alkylating agent. To prepare the compound, the N-heterocyclic carbonyl compound and an excess of alkylating agent are dissolved in toluene and the resulting solution is heated with stirring for several hours to 90-100° C. until the starting compound has disappeared. The alkylating agent may be used in a 10- to 20-fold excess over the N-heterocyclic carbonyl compound. During the reaction, the quaternary ammonium compound generally precipitates in resin-like form. On completion of the reaction, the resin is repeatedly extracted with hot toluene in order completely to remove the alkylating agent and dried. The end product is generally resin-like or occasionally crystalline.
Suitable compounds containing a primary or secondary amino group as component B are, for example, primary aromatic amines, such as N,N-dimethyl-, N,N-diethyl-, N-(2-hydroxyethyl)-N-ethyl-, N,N-bis-(2-hydroxyethyl)-, N-(2-methoxyethyl)-, 2,3-, 2,4-, 2,5-dichloro-p-phenylenediamine, 2-chloro-p-phenylenediamine, 2,5-dihydroxy-4-morpholinoaniline dihydrobromide, 2-, 3-, 4-aminophenol, 2-aminomethyl-4-aminophenol, 2-hydroxymethyl-4-aminophenol, o-, p-phenylenediamine, o-toluylenediamine, 2,5-diaminotoluene, -phenol, -phenethol, 4-amino-3-methylphenol, 2-(2,5-diaminophenyl)-ethanol, 2,4-diaminophenoxyethanol, 2-(2,5-diaminophenoxy)-ethanol, 4-methylamino-, 3-amino-4-(2′-hydroxyethyloxy)-, 3,4-methylenediamino-, 3,4-methylenedioxyaniline, 3-amino-2,4-dichloro-, 4-methylamino-, 2-methyl-5-amino-, 3-methyl-4-amino-, 2-methyl-5-(2-hydroxyethylamino)-, 6-methyl-3-amino-2-chloro-, 2-methyl-5-amino-4-chloro-, 3,4-methylenedioxy-, 5-(2-hydroxyethylamino)-4-methoxy-2-methyl-, 4-amino-2-hydroxymethylphenol, 1,3-diamino-2,4-dimethoxybenzene, 2-, 3-, 4-aminobenzoic acid, -phenylacetic acid, 2,3-, 2,4-, 2,5-, 3,4-, 3,5-diaminobenzoic acid, 4-, 5-aminosalicylic acid, 3-amino-4-hydroxy-, 4-amino-3-hydroxybenzoic acid, 2-, 3-, 4-aminobenzenesulfonic acid, 3-amino4-hydroxybenzenesulfonic acid, 4-amino-3-hydroxynaphthalene-1-sulfonic acid, 6-amino-7-hydroxynaphthalene-2-sulfonic acid, 7-amino4-hydroxynaphthalene-2-sulfonic acid, 4-amino-5-hydroxynaphthalene-2,7-disulfonic acid, 3-amino-2-naphthoic acid, 3-aminophthalic acid, 5-aminoisophthalic acid, 1,3,5-, 1,2,4-triaminobenzene, 1,2,4,5-tetraaminobenzene, 2,4,5-triaminophenol, pentaaminobenzene, hexaaminobenzene, 2,4,6-triaminoresorcinol, 4,5-diaminopyrocatechol, 4,6-diaminopyrogallol, 3,5-diamino-4-hydroxypyrocatechol, aromatic anilines and phenols containing another aromatic radical corresponding to formula II:
in which
R 6 is a hydroxy group or an amino group which may be substituted by C 1-4 alkyl, C 1-4 hydroxyalkyl or C 1-4 alkoxy-C 1-4 -alkyl groups,
R 7 , R 8 , R 9 , R 10 and R 11 represent hydrogen, a hydroxy group or an amino group which may be substituted by a C 1-4 alkyl, C 1-4 hydroxyalkyl, C 1-4 aminoalkyl or C 1-4 alkoxy-C 1-4 -alkyl group or a carboxylic or sulfonic acid group and Z is a direct bond, a saturated or unsaturated optionally hydroxy-substituted carbon chain containing 1 to 4 carbon atoms, a carbonyl, sulfonyl or imino group, an oxygen or sulfur atom or a group corresponding to formula III:
Q—(CH 2 —P—CH 2 —Q′) 0 (III)
in which
P is a direct bond, a CH 2 or CHOH group,
Q and Q′ independently of one another represent an oxygen atom, an NR 12 group, where R 12 is hydrogen, a C 1-4 alkyl or a hydroxy-C 1-4 -alkyl group, the group O—(CH 2 ) p —NH or NH—(CH 2 ) p′ —O, where p and p′=2 or 3, and
o is a number of 1 to 4, such as for example 4,4′-diaminostilbene, 4,4′-diaminostilbene-2,2′-disulfonic acid monosodium or disodium salt, 4-amino4′-dimethylaminostilbene, 4,4′-diaminodiphenyl -methane, -sulfide, -sulfoxide, -amine, 4,4′-diaminodiphenylamine-2-sulfonic acid, 4,4′-diaminobenzophenone, -diphenylether, 3,3′,4,4′-tetraaminodiphenyl, 3,3′4,4′-tetraaminobenzophenone, 1,3-bis-(2,4-diaminophenoxy)-propane, 1,8-bis-(2,5-diaminophenoxy)-3,6-dioxaoctane, 1,3-bis-(4-aminophenylamino)-propane, -2-propanol, 1,3-bis-[N-(4-aminophenyl)-2-hydroxyethylamino]-2-propanol, N,N-bis-[2-(4-aminophenoxy)-ethyl]-methylamine, N-phenyl-1,4-phenylenediamine.
The compounds mentioned above may be used both in free form and in the form of their physiologically compatible salts, more especially as salts of inorganic acids, such as hydrochloric acid or sulfuric acid.
Suitable nitrogen-containing heterocyclic compounds are, for example, 2-, 3-, 4-amino-, 2-amino-3-hydroxy-, 2,6-diamino-, 2,5-diamino-, 2,3-diamino-, 2-dimethylamino-5-amino-, 2-methylamino-3-amino-6-methoxy-, 2,3-diamino-6-methoxy-, 2,6-dimethoxy-3,5-diamino-, 2,4,5-triamino-, 2,6-dihydroxy-3,4-dimethyl pyridine, 2,4-dihydroxy-5,6-diamino-, 4,5,6-triamino-, 4-hydroxy-2,5,6-triamino-, 2-hydroxy-4,5,6-triamino-, 2,4,5,6-tetraamino-, 2-methylamino-4,5,6-triamino-, 2,4-, 4,5-diamino-, 2-amino-4-methoxy-6-methyl pyrimidine, 3,5-diaminopyrazole, -1,2,4-triazole, 3-amino-, 3-amino-5-hydroxypyrazole, 2-, 3-, 8-aminoquinoline, 4-aminoquinaldine, 2-, 6-aminonicotinic acid, 5-aminoisoquinoline, 5-, 6-aminoindazole, 5-, 7-aminobenzimidazole, -benzothiazole, 2,5-dihydroxy-4-morpholinoaniline and indole and indoline derivatives and physiologically compatible salts thereof. Preferred examples of indole and indoline derivatives are 5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole, N-ethyl-5,6-dihydroxyindole, N-propyl-5,6-dihydroxyindole, N-butyl-5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, 6-hydroxyindole, 6-aminoindole and 4-aminindole. Also preferred are 5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline, N-ethyl-5,6-dihydroxyindoline, N-propyl-5,6-dihydroxyindoline, N-butyl-5,6-dihydroxyindoline, 5,6-dihydroxyindoline-2-carboxylic acid, 6-hydroxyindoline, 6-aminoindoline and 4-aminoindoline. The compounds mentioned above may be used both in free form and in the form of their physiologically compatible salts, for example as salts of inorganic acids, such as hydrochloric acid or sulfuric acid.
Suitable amino acids are any naturally occurring and synthetic amino acids, for example the amino acids obtainable by hydrolysis from vegetable or animal proteins, for example collagen, keratin, casein, elastin, soya protein, wheat gluten or almond protein. Both acidic and alkaline amino acids may be used. Preferred amino acids are arginine, histidine, tyrosine, phenyl alanine, DOPA (dihydroxyphenyl alanine), ornithine, lysine and tryptophane. However, other amino acids, such as 6-aminocaproic acid for example, may also be used.
The oligopeptides may be naturally occurring or synthetic oligopeptides and the oligopeptides present in polypeptide or protein hydrolyzates providing they are sufficiently soluble in water for use in the colorants according to the invention. Examples of such polypeptides are glutathione and the oligopeptides present in the hydrolyzates of collagen, keratin, casein, elastin, soya protein, wheat gluten or almond protein. These oligopeptides are preferably used together with compounds containing a primary or secondary amino group or with aromatic hydroxy compounds.
Suitable aromatic hydroxy compounds are, for example, 2-, 4-, 5-methyl resorcinol, 2,5-dimethyl resorcinol, resorcinol, 3-methoxyphenol, pyrocatechol, hydroquinone, pyrogallol, phloroglucinol, hydroxyhydroquinone, 2-, 3-, 4-methoxy-, 3-dimethylamino-, 2-(2-hydroxyethyl)-, 3,4-methylenedioxyphenol, 2,4-, 3,4-dihydroxybenzoic acid, -phenylacetic acid, gallic acid, 2,4,6-trihydroxybenzoic acid, -acetophenone, 2-, 4-chlororesorcinol, 1-naphthol, 1,5-, 2,3-, 2,7-dihydroxynaphthalene, 6-dimethylamino-4-hydroxy-2-naphthalene sulfonic acid, 3,6-dihydroxy-2,7-naphthalene sulfonic acid.
Examples of CH-active compounds are 1,2,3,3-tetramethyl-3H-indolium iodide, 1,2,3,3-tetraamethyl-3H-indolium-p-toluene sulfonate, 1,2,3,3-tetramethyl-3H-indolium methane sulfonate, Fischer's base (1,3,3-trimethyl-2-methyleneindoline) 2,3-dimethylbenzothiazolium iodide, 2,3-dimethylbenzothiazolium-p-toluene sulfonate, rhodanine, rhodanine-3-acetic acid, 1-ethyl-2-quinaldinium iodide, 1-methyl-2-quinaldinium iodide, barbituric acid, thiobarbituric acid, 1,3-dimethyl thiobarbituric acid, diethyl thiobarbituric acid, oxindole, 3-indoxyl acetate, coumaranone and 1-methyl-3-phenyl-2-pyrazolinone.
In all colorants, several different coloring substances may also be used together. Several different components from the groups of compounds containing a primary or secondary amino group, nitrogen-containing heterocycles, aromatic hydroxy compounds or amino acids may also be used together.
Oxidizing agents, for example H 2 O 2 , need not present where the onium aldehydes and ketones of formula I are used in accordance with the invention. However, it may be desirable in some cases to add hydrogen peroxide or other oxidizing agents to the compositions according to the invention to obtain shades which are lighter than the keratin-containing fibers to be colored. Oxidizing agents are generally used in a quantity of 0.01 to 6% by weight, based on the solution applied. A preferred oxidizing agent for human hair is H 2 O 2 .
The colorants according to the invention give a broad range of color tones in the range from yellow through yellow-brown, orange, brown-orange, mid-brown, dark brown, violet, dark violet to blue-black and black. Their fastness properties are excellent and their sensitizing potentials very low.
In one preferred embodiment, the colorants according to the invention contain typical substantive dyes, for example from the group of nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones or indophenols, in addition to the compounds present in accordance with the invention in order further to modify the color tones. Preferred substantive dyes are the compounds known under the International names or commercial names of HC Yellow 2, HC Yellow 4, HC Yellow 5, HC Yellow 6, Basic Yellow 57, Disperse Orange 3, HC Red 3, HC Red BN, Basic Red 76, HC Blue 2, HC Blue 12, Disperse Blue 3, Basic Blue 99, HC Violet 1, Disperse Violet 1, Disperse Violet 4, Disperse Black 9, Basic Brown 16 and Basic Brown 17 and also 4-amino-2-nitrodiphenylamine-2′-carboxylic acid, 6-nitro-1,2,3,4-tetrahydroquinoxaline, hydroxyethyl-2-nitrotoluidine, picramic acid, 2-amino-6-chloro4-nitrophenol, 4-ethylamino-3-nitrobenzoic acid and 2-chloro-6-ethylamino-1-hydroxy4-nitrobenzene. The compositions according to the invention in this embodiment contain the substantive dyes in a quantity of, preferably, 0.01 to 20% by weight, based on the colorant as a whole.
In addition, the compositions according to the invention may also contain naturally occurring dyes such as, for example, henna red, henna neutral, henna black, camomile blossom, sandalwood, black tea, black alder bark, sage, logwood, madder root, catechu, sedre and alkanet.
The oxidation dye precursors or the substantive dyes present, if any, do not have to be single compounds. Instead, the hair colorants according to the invention—due to the processes used for producing the individual dyes—may contain small quantities of other components providing they do not adversely affect the coloring result or have to be ruled out for other reasons, for example toxicological reasons.
The colorants according to the invention produce intensive colors even at physiologically compatible temperatures of <45° C. Accordingly, they are particularly suitable for coloring human hair. For application to human hair, the colorants are normally incorporated in a water-containing cosmetic carrier. Suitable water-containing cosmetic carriers are, for example, creams, emulsions, gels or even surfactant-containing foaming solutions, for example shampoos or other formulations suitable for application to the keratin-containing fibers. If necessary, the colorants may even be incorporated in water-free carriers.
The colorants according to the invention may also contain any of the known active substances, additives and auxiliaries typical of such formulations. In many cases, the colorants contain at least one surfactant, both anionic and zwitterionic, ampholytic, nonionic and cationic surfactants being suitable in principle. In many cases, however, it has been found to be of advantage to select the surfactants from anionic, zwitterionic or nonionic surfactants.
Suitable anionic surfactants for the compositions according to the invention are any anionic surface-active substances suitable for use on the human body. Such substances are characterized by a water-solubilizing anionic group such as, for example, a carboxylate, sulfate, sulfonate or phosphate group and a lipophilic alkyl group containing around 10 to 22 carbon atoms. In addition, glycol or polyglycol ether groups, ester, ether, amide groups and hydroxyl groups may also be present in the molecule. The following are examples of suitable anionic surfactants—in the form of the sodium, potassium and ammonium salts and the mono-, di- and trialkanolammonium salts containing 2 or 3 carbon atoms in the alkanol group:
linear fatty acids containing 10 to 22 carbon atoms (soaps),
ether carboxylic acids corresponding to the formula R—O—(CH 2 —CH 2 O) x —CH 2 —COOH, in which R is a linear alkyl group containing 10 to 22 carbon atoms and x=0 or 1 to 16,
acyl sarcosides containing 10 to 18 carbon atoms in the acyl group,
acyl taurides containing 10 to 18 carbon atoms in the acyl group,
acyl isethionates containing 10 to 18 carbon atoms in the acyl group,
sulfosuccinic acid mono- and dialkyl esters containing 8 to 18 carbon atoms in the alkyl group and sulfosuccinic acid monoalkyl polyoxyethyl esters containing 8 to 18 carbon atoms in the alkyl group and 1 to 6 oxyethyl groups,
linear alkane sulfonates containing 12 to 18 carbon atoms,
linear α-olefin sulfonates containing 12 to 18 carbon atoms,
α-sulfofatty acid methyl esters of fatty acids containing 12 to 18 carbon atoms,
alkyl sulfates and alkyl polyglycol ether sulfates corresponding to the formula R—O(CH 2 —CH 2 O) x —SO 3 H, in which R is a preferably linear alkyl group containing 10 to 18 carbon atoms and x=0 or 1 to 12,
mixtures of surface-active hydroxysulfonates according to DE-A-37 25 030,
sulfated hydroxyalkyl polyethylene and/or hydroxyalkylene propylene glycol ethers according to DE-A-37 23 354,
sulfonates of unsaturated fatty acids containing 12 to 24 carbon atoms and 1 to 6 double bonds according to DE-A-39 26 344,
esters of tartaric acid and citric acid with alcohols in the form of addition products of around 2 to 15 molecules of ethylene oxide and/or propylene oxide with fatty alcohols containing 8 to 22 carbon atoms.
Preferred anionic surfactants are alkyl sulfates, alkyl polyglycol ether sulfates and ether carboxylic acids containing 10 to 18 carbon atoms in the alkyl group and up to 12 glycol ether groups in the molecule and, in particular, salts of saturated and, more particularly, unsaturated C 8-22 carboxylic acids, such as oleic acid, stearic acid, isostearic acid and palmitic acid.
In the context of the invention, zwitterionic surfactants are surface-active compounds which contain at least one quaternary ammonium group and at least one —COO (−) or —SO 3 (−) group in the molecule. Particularly suitable zwitterionic surfactants are the so-called betaines, such as N-alkyl-N,N-dimethyl ammonium glycinates, for example coconutalkyl dimethyl ammonium glycinate, N-acylaminopropyl-N,N-dimethyl ammonium glycinates, for example coconutacylaminopropyl dimethyl ammonium glycinate, and 2-alkyl-3-carboxymethyl-3-hydroxyethyl imidazolines containing 8 to 18 carbon atoms in the alkyl or acyl group and coconutacylaminoethyl hydroxyethyl carboxymethyl glycinate. A preferred zwitterionic surfactant is the fatty acid amide derivative known by the CTFA name of Cocamidopropyl Betaine.
Ampholytic surfactants are surface-active compounds which, in addition to a C 8-18 alkyl or acyl group, contain at least one free amino group and at least one —COOH or —SO 3 H group in the molecule and which are capable of forming inner salts. Examples of suitable ampholytic surfactants are N-alkyl glycines, N-alkyl propionic acids, N-alkyl aminobutyric acids, N-alkyl iminodipropionic acids, N-hydroxyethyl-N-alkyl amidopropyl glycines, N-alkyl taurines, N-alkyl sarcosines, 2-alkyl aminopropionic acids and alkyl aminoacetic acids containing around 8 to 18 carbon atoms in the alkyl group. Particularly preferred ampholytic surfactants are N-coconutalkyl aminopropionate, coconutacyl aminoethyl aminopropionate and C 12-18 acyl sarcosine.
Nonionic surfactants contain, for example, a polyol group, a polyalkylene glycol ether group or a combination of polyol and polyglycol ether groups as the hydrophilic group. Examples of such compounds are
products of the addition of 2 to 30 moles of ethylene oxide and/or 0 to 5 moles of propylene oxide onto linear fatty alcohols containing 8 to 22 carbon atoms, onto fatty acids containing 12 to 22 carbon atoms and onto alkylphenols containing 8 to 15 carbon atoms in the alkyl group,
C 12-22 fatty acid monoesters and diesters of products of the addition of 1 to 30 moles of ethylene oxide onto glycerol,
C 8-22 alkyl mono- and oligoglycosides and ethoxylated analogs thereof,
products of the addition of 5 to 60 moles of ethylene oxide onto castor oil and hydrogenated castor oil,
products of the addition of ethylene oxide onto sorbitan fatty acid esters,
products of the addition of ethylene oxide onto fatty acid alkanolamides.
Examples of cationic surfactants suitable for use in the hair treatment formulations according to the invention are, in particular, quaternary ammonium compounds. Preferred quaternary ammonium compounds are ammonium halides, such as alkyl trimethyl ammonium chlorides, dialkyl dimethyl ammonium chlorides and trialkyl methyl ammonium chlorides, for example cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, lauryl dimethyl ammonium chloride, lauryl dimethyl benzyl ammonium chloride and tricetyl methyl ammonium chloride. Other cationic surfactants suitable for use in accordance with the invention are the quaternized protein hydrolyzates.
Also suitable for use in accordance with the invention are cationic silicone oils such as, for example, the commercially available products Q2-7224 (manufacturer: Dow Corning; a stabilized trimethyl silyl amodimethicone), Dow Corning 929 Emulsion (containing a hydroxylamino-modified silicone which is also known as amodimethicone), SM-2059 (manufacturer General Electric), SLM-55067 (manufacturer: Wacker) and Abil®-Quat 3270 and 3272 (manufacturer: Th. Goldschmidt; diquaternary polydimethyl siloxanes, quatemium-80).
Alkyl amidoamines, particularly fatty acid amidoamines, such as the stearyl amidopropyl dimethyl amine obtainable as Tego Amid®S 18, are distinguished not only by their favorable conditioning effect, but also and in particular by their ready biodegradability.
Quaternary ester compounds, so-called “esterquats”, such as the methyl hydroxyalkyl dialkoyloxyalkyl ammonium methosulfates marketed under the trade name of Stepantex®, are also readily biodegradable.
One example of a quaternary sugar derivative suitable for use as a cationic surfactant is the commercially available product Glucquat®100 (CTFA name: Lauryl Methyl Gluceth-10 Hydroxypropyl Dimonium Chloride).
The compounds containing alkyl groups used as surfactants may be single compounds. In general, however, these compounds are produced from native vegetable or animal raw materials so that mixtures with different alkyl chain lengths dependent upon the particular raw material are obtained.
The surfactants representing addition products of ethylene and/or propylene oxide with fatty alcohols or derivatives of these addition products may be both products with a “normal” homolog distribution and products with a narrow homolog distribution. Products with a “normal” homolog distribution are mixtures of homologs which are obtained in the reaction of fatty alcohol and alkylene oxide using alkali metals, alkali metal hydroxides or alkali metal alcoholates as catalysts. By contrast, narrow homolog distributions are obtained when, for example, hydrotalcites, alkaline earth metal salts of ether carboxylic acids, alkaline earth metal oxides, hydroxides or alcoholates are used as catalysts. The use of products with a narrow homolog distribution can be of advantage.
Other active substances, auxiliaries and additives are, for example,
nonionic polymers such as, for example, vinyl pyrrolidone/vinyl acrylate copolymers, polyvinyl pyrrolidone and vinyl pyrrolidone/vinyl acetate copolymers and polysiloxanes,
cationic polymers, such as quaternized cellulose ethers, polysiloxanes containing quaternary groups, dimethyl diallyl ammonium chloride polymers, acrylamide/dimethyl diallyl ammonium chloride copolymers, dimethyl aminoethyl methacrylate/vinyl pyrrolidone copolymers quaternized with diethyl sulfate, vinyl pyrrolidone/imidazolinium methochloride copolymers and quaternized polyvinyl alcohol,
zwitterionic and amphoteric polymers such as, for example, acrylamido-propyl/trimethyl ammonium chloride/acrylate copolymers and octyl acrylamide/methyl methacrylate/tert.butyl aminoethyl methacrylate/2-hydroxypropyl methacrylate copolymers,
anionic polymers such as, for example, polyacrylic acids, crosslinked polyacrylic acids, vinyl acetate/crotonic acid copolymers, vinyl pyrrolidone/vinyl acrylate copolymers, vinyl acetate/butyl maleate/isobornyl acrylate copolymers, methyl vinyl ether/maleic anhydride copolymers and acrylic acid/ethyl acrylate/N-tert.butyl acrylamide terpolymers,
thickeners, such as agar agar, guar gum, alginates, xanthan gum, gum arabic, karaya gum, locust bean gum, linseed gums, dextrans, cellulose derivatives, for example methyl cellulose, hydroxyalkyl cellulose and carboxymethyl cellulose, starch fractions and derivatives, such as amylose, amylopectin and dextrins, clays such as, for example, bentonite or fully synthetic hydrocolloids such as, for example, polyvinyl alcohol,
structurants, such as glucose and maleic acid,
hair-conditioning compounds, such as phospholipids, for example soya lecithin, egg lecithin and kephalins, and also silicone oils,
protein hydrolyzates, more particularly elastin, collagen, keratin, milk protein, soya protein and wheat protein hydrolyzates, condensation products thereof with fatty acids and quaternized protein hydrolyzates,
perfume oils, dimethyl isosorbide and cyclodextrins,
solubilizers, such as ethanol, isopropanol, ethylene glycol, propylene glycol, glycerol and diethylene glycol,
antidandruff agents, such as Piroctone Olamine and Zinc Omadine,
other substances for adjusting the pH value,
active substances, such as panthenol, pantothenic acid, allantoin, pyrrolidone carboxylic acids and salts thereof, plant extracts and vitamins,
cholesterol,
UV filters,
consistency factors, such as sugar esters, polyol esters or polyol alkyl ethers,
fats and waxes, such as spermaceti, beeswax, montan wax, paraffins, fatty alcohols and fatty acid esters,
fatty acid alkanolamides,
complexing agents, such as EDTA, NTA and phosphonic acids,
swelling and penetration agents, such as glycerol, propylene glycol monoethyl ether, carbonates, hydrogen carbonates, guanidines, ureas and primary, secondary and tertiary phosphates, imidazoles, tannins, pyrrole,
opacifiers, such as latex,
pearlizers, such as ethylene glycol mono- and distearate,
propellents, such as propane/butane mixtures, N 2 O, dimethyl ether, CO 2 and air and
antioxidants.
To produce the colorants according to the invention, the constituents of the water-containing carrier are used in the usual quantities for this purpose. For example, emulsifiers are used in concentrations of 0.5 to 30% by weight while thickeners are used in concentrations of 0.1 to 25% by weight, based on the colorant as a whole.
It can be of advantage to the coloring result to add ammonium or metal salts to the colorants. Suitable metal salts are, for example, formates, carbonates, halides, sulfates, butyrates, valerates, caproates, acetates, lactates, glycolates, tartrates, citrates, gluconates, propionates, phosphates and phosphonates of alkali metals, such as potassium, sodium or lithium, alkaline earth metals, such as magnesium, calcium, strontium or barium, or of aluminium, manganese, iron, cobalt, copper or zinc, sodium acetate, lithium bromide, calcium bromide, calcium gluconate, zinc chloride, zinc sulfate, magnesium chloride, magnesium sulfate, ammonium carbonate, chloride and acetate being preferred. These salts are preferably present in a quantity of 0.03 to 65 mmol and more preferably in a quantity of 1 to 40 mmol, based on 100 g of the colorant as a whole.
The pH value of the ready-to-use coloring compositions is normally in the range from 2 to 11 and preferably in the range from 5 to 9.
In order to color the keratin-containing fibers, more especially human hair, the colorants are generally applied to the hair in the form of the water-containing cosmetic carrier in a quantity of 100 g, left thereon for about 30 minutes and then rinsed out or washed out with a commercially available shampoo.
The compounds of components A and B may either be applied to the hair simultaneously or even successively, in which case it does not matter which of the two components is applied first. Reaction products of components A and B may also be used. The ammonium or metal salts optionally present may be added to the first component or to the second component. A time of up to 30 minutes can be allowed to pass between application of the first component and application of the second component. The fibers may even be pretreated with the salt solution.
Components A and B of the compositions according to the invention may be stored either separately or together either in the form of a liquid or paste-like preparation (aqueous or water-free) or as a dry powder. If the components are stored together in a liquid preparation, the preparation in question should be substantially free from water to reduce any risk of the components reacting. Where the reactive components are stored separately, they are mixed thoroughly together only shortly before application. Where the components are stored as a dry powder, a defined quantity of warm water (50 to 80° C.) is normally added and a homogeneous mixture prepared before application.
EXAMPLES
Preparation of Compounds Corresponding to Formula I
0.5 mol of the N-heterocyclic carbonyl compound and 1 mol of methyl sulfate as alkylating agent were dissolved in 500 ml of toluene and the resulting solution was heated with stirring for 5 hours to 100° C. The quaternary ammonium compound precipitates during the reaction. The reaction product was extracted twice with hot toluene in order completely to remove the alkylating agent and then dried. The end product was mostly resin-like or crystalline.
The following compounds were obtained:
4-acetyl-1-methyl pyridinium methane sulfonate, yellowish, resin-like
4-benzoyl-1-methyl pyridinium methane sulfonate: colorless, Mp. 178° C.
2- and 4-formyl-1-methyl quinolinium methane sulfonate: yellowish, resin-like
4-(2-formylvinylyl)-1-methyl pyridinium trifluoromethane sulfonate: yellowish, resin-like
4-acetyl-1-methyl quinolinium methane sulfonate: reddish, resin-like
Preparation of a Coloring Solution
A suspension of 10 mmol of a coloring component, 10 mmol of an amine, 10 mmol of sodium acetate and 1 drop of a 20% fatty alkyl ether sulfate solution in 100 ml of water was prepared. The suspension was briefly heated to around 80° C. and filtered after cooling, after which the pH value was adjusted to 6.
One tress of 90% grey, non-pretreated human hair was placed in this coloring solution for 30 minutes at 30° C. The colored tress was then rinsed for 30 seconds with luke-warm water, dried in a stream of warm air (30-40° C.) and then combed. The colors were visually evaluated in daylight.
The particular shades and depths of color are shown in the following Tables.
The depth of color was evaluated on the following scale:
— very faint, if any, color (+) weak intensity + medium intensity +(+) medium to strong intensity ++ strong intensity ++(+) strong to very strong intensity +++ very strong intensity
TABLE 1
Coloring with 4-formyl-1-methylpyridinium benzenesulfonate
Depth
Component B
Shade
of color
—
—
—
2,5-Diaminotoluene × H 2 SO 4
Orange-red
++(+)
2,4,5,6-Tetraaminopyrimidine × H 2 SO 4
Brown-orange
++
1,8-bis-(2,5-diaminophenoxy)-3,6-
Orange brown
++
dioxaoctane × 4 HCl
2-Methylamino-3-amino-6-methoxy-
Dark violet
+++
pyridine × 2 HCl
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Orange-red
++(+)
2-Aminomethyl-4-aminophenol × 2HCl
Yellow-olive brown
++
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Violet-red
++(+)
diamine × HCl
4,4′-Diaminodiphenylamine × H 2 SO 4
Black-violet
+++
2,6-Dimethoxy-3,5-diamino-
Dark brown
+++
pyridine × 2 HCl
Fischer's base
Violet-red
++
TABLE 2
Coloring with 4-acetyl-1-methylpyridinium benzenesulfonate
Depth
Component B
Shade
of Color
—
—
—
2,5-Diaminotoluene × H 2 SO 4
Red-brown
++
2,4,5,6-Tetraaminopyrimidine × H 2 SO 4
Brown-red
++
1,8-bis-(2,5-diaminophenoxy)-3,6-
Dark blue-grey
++(+)
dioxaoctane × 4 HCl
2-Methylamino-3-amino-6-methoxy-
Violet brown
+++
pyridine × 2 HCl
2,-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Red-rown
+(+)
2-Aminomethyl-4-aminophenol × 2HCl
Yellow-brown
+(+)
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Violet-brown
++
diamine × HCl
4,4′-Diaminodiphenylamine × H 2 SO 4
Black
+++
2,6-Dimethoxy-3,5-diamino-
Black
+++
pyridine × 2 HCl
TABLE 3
Coloring with 4-benzoyl-1-methylpyridinium methanesulfonate
Component B
Shade
Depth of color
—
—
—
2,5-Diaminotoluene × H 2 SO 4
Dark violet
+++
2,4,5,6-Tetraaminopyrimidine × H 2 SO 4
Orange
++
1,8-bis-(2,5-diaminophenoxy)-3,6-
Blue-black
+++
dioxaoctane × 4 HCl
2-Methylamino-3-amino-6-methoxy-
Black-brown
+++
pyridine × 2 HCl
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Red-rown
++
2-Aminomethyl-4-aminophenol × 2HCl
Mid-brown
+(+)
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Violet-brown
++
diamine × HCl
4,4′-Diaminodiphenylamine × H 2 SO 4
Black
+++
2,6-Dimethoxy-3,5-diamino-
Black
+++
pyridine × 2 HCl
TABLE 4
Coloring with 2-oximomethyl-1-methylpyridinium methanesulfonate
Component B
Shade
Depth of color
—
—
—
2,5-Diaminotoluene × H 2 SO 4
Violet-brown
++(+)
2,4,5,6-Tetraaminopyrimidine × H 2 SO 4
Orange
++(+)
1,8-bis-(2,5-diaminophenoxy)-3,6-
Blue-black
+++
dioxaoctane × 4 HCl
2-Methylamino-3-amino-6-methoxy-
Dark brown
+++
pyridine × 2 HCl
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Violet-brown
++
2-Aminomethyl-4-aminophenol × 2HCl
Light brown
+
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Mid-brown
++
diamine × HCl
4,4′-Diaminodiphenylamine × H 2 SO 4
Blue-black
+++
2,6-Dimethoxy-3,5-diamino-
Black
+++
pyridine × 2 HCl
TABLE 5
Coloring with 2-formyl-1-methylquinolinium trifluoromethanesulfonate
Component B
Shade
Depth of color
—
Light brown
+
2,5-Diaminotoluene × H 2 SO 4
Blue-black
+++
2,4,5,6-Tetraaminopyrimidine × H 2 SO 4
Violet-red
++(+)
1,8-bis-(2,5-diaminophenoxy)-3,6-
Blue-black
+++
dioxaoctane × 4 HCl
2-Methylamino-3-amino-6-methoxy-
Black
+++
pyridine × 2 HCl
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Violet-black
+++
2-Aminomethyl-4-aminophenol × 2HCl
Black
+++
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Blue-black
+++
diamine × HCl
4,4′-Diaminodiphenylamine × H 2 SO 4
Blue-black
+++
2,6-Dimethoxy-3,5-diamino-
Blue-black
+++
pyridine × 2 HCl
3-Methyl-4-aminophenol (oxyred)
Red
++
TABLE 6
Coloring with 4-formyl-1-methylquinolinium methyl sulfate
Component B
Shade
Depth of color
2,5-Diaminotoluene × H 2 SO 4
Dark violet
+++
2-Methylamino-3-amino-6-methoxy-
Dark blue
+++
pyridine × 2 HCl
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Dark violet
+++
2-Aminomethyl-4-aminophenol × 2HCl
Dark brown
++
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Dark blue
+++
diamine × HCl
2,6-Dimethoxy-3,5-diamino-
Dark brown
+++
pyridine × 2 HCl
TABLE 7
Coloring with 4-formyl-1-methylquinolinium methanesulfonate
Depth
Component B
Shade
of color
—
Pink
+
2,5-Diaminotoluene × H 2 SO 4
Brown-violet
+++
2,4,5,6-Tetraaminopyrimidine × H 2 SO 4
Dark violet-red
+++
1,8-bis-(2,5-diaminophenoxy)-3,6-
Red-violet
+++
dioxaoctane × 4 HCl
2-Methylamino-3-amino-6-methoxy-
Blue-black
+++
pyridine × 2 HCl
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Dark violet
+++
2-Aminomethyl-4-aminophenol × 2HCl
Orange-brown
++
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Black-blue
+++
diamine × HCl
4,4′-Diaminodiphenylamine × H 2 SO 4
Black-blue
+++
2,6-Dimethoxy-3,5-diamino-
Dark brown
+++
pyridine × 2 HCl
3,4-Diaminobenzoic acid
Dark Violet
++(+)
4-Hydroxy-2,5,6-triaminopyrimidine
Brown pink
+(+)
sulfate
Coloring with the reaction product of components A and B
Component A: 4-formyl-1-methlquinolinium methanesulfonate
Component B: N,N-bis-(2-hydroxyethyl)-p-phenylenediamine×HCl
Shade: black-blue, depth of color +++
TABLE 8
Coloring with 4-(2-formylvinyl)-1-methylquinolinium
trifluoromethanesulfonate
Depth
Component B
Shade
of color
—
Brown-yellow
+
2,5-Diaminotoluene × H 2 SO 4
Violet-red
++(+)
2-Methylamino-3-amino-6-methoxy-
Red-black
+++
pyridine × 2 HCl
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Red
++(+)
2-Aminomethyl-4-aminophenol × 2HCl
Brown-yellow/
++
bronze
4,4′-Diaminodiphenylamine × H 2 SO 4
Black-violet
+++
2,6-Dimethoxy-3,5-diamino-
Blue-black
+++
pyridine × 2 HCl
TABLE 9
Coloring with 4-acetylquinolinium methanesulfonate
Depth
Component B
Shade
of color
2,5-Diaminotoluene × H 2 SO 4
Red-brown
++
2-(2,5-Diaminophenyl)-ethanol × H 2 SO 4
Red-brown
++
2-Aminomethyl-4-aminophenol × 2HCl
Orange-brown
+(+)
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Dark brown
++(+)
diamine × HCl
2-Amino-4-(2-hydroxyethylamine)-
Grey-black
++(+)
anisole × H 2 SO 4 (Lehmann's blue)
3-Methyl-p-aminophenol
Orange-brown
+(+)
5-Amino-o-cresol
Red-brown
++
TABLE 10
Coloring with 4-pyridinecarboxaldehyde-N-oxide
Component B
Shade
Depth of color
2,4,5,6-Tetraaminopyrimidine × H 2 SO 4
Yelow
++
2-Methylamino-3-amino-6-methoxy-
Orange-brown
++
pyridine × 2 HCl
N,N-bis-(2-hydroxyethyl)-p-phenylene-
Yellow-brown
++
diamine × 2 HCl | The invention relates to the utilization of onium aldehydes and onium ketones of formula (1) or the derivatives thereof.
In the formula, R 1 represents a hydrogen atom, a (C 1 -C 4 )-alkyl group, an aryl group or a heteroaryl group. R 2 , R 3 , R 4 , independent of one another, each represent a hydrogen atom, a halogen atom, a (C 1 -C 4 )-alkyl group, a (C 1 -C 4 )-alkoxyl group, hydroxy-(C 1 -C 4 )-alkoxyl group, hydroxyl group, nitro group, aryl group, trifluoromethyl group, amino group or (C 1 -C 4 )-acyl group. Said amino group can be substituted by (C 1 -C 4 )-alkyl groups. Two of the residuals can be combined to form a fused benzene ring. R 5 represents a (C 1 -C 4 )-alkyl group, aryl group, alkylaryl group or heteroaryl group. X designates a direct bonding or an optionally substituted vinyl group or phenyl group and Y— represents halogenide, benzenesulfonate, p-toluenesulfonate, methane sulfonate, trifluoromethane sulfonate, perchlorate, sulfate, hydrogen sulfate, tetrachlorozincate or N-oxide of the heterocyclic compound. In order to dye fibers containing keratin, onium aldehydes and onium ketones or the derivatives thereof are utilized in combination with at least one compound with a primary or secondary amino group or hydroxyl group. The compound is selected from primary or secondary aliphatic or aromatic amines, heterocyclic compounds containing nitrogen, amino acids, oligopeptides, said oligopeptides containing from 2 to 9 amino acids, as well as aromatic hydroxy compounds, and/or at least one CH-active compound. | 0 |
TECHNICAL FIELD
[0001] The application relates generally to the computer generation of fonts, typefaces and graphics.
BACKGROUND OF THE INVENTION
[0002] The rendering of text and graphics is a fundamental visual aspect of a graphical user interface. Powerful graphics hardware capable of sophisticated pixel processing is tending to become standard equipment on personal computers, gaming systems and the like. Using graphics hardware to improve the visual appearance of text and graphics tends to have a positive visual impact on system performance.
[0003] Furthermore, the animation or distortion of text in multimedia web applications tends to negate the economy of current font caching mechanisms. The use of pixel processors tends to provide opportunities to combine flexibility with high performance in rendering outline fonts and vector graphics.
SUMMARY OF THE INVENTION
[0004] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.
[0005] The present invention provides a resolution independent method of rendering outline fonts, including Open Type™ and TrueType™ font outlines. This approach uses an in-out test to determine if a pixel belongs to the interior or exterior of the screen space projection of the font outline. This test is based on a relationship between the parametric and implicit form of a rational quadratic curve.
[0006] Many of the attendant features of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description considered in connection with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
[0007] These and other features and advantages of the present invention will be better understood from the following detailed description read in light of the accompanying drawings, where:
[0008] FIG. 1 illustrates the display of vector drawn images and bit mapped images.
[0009] FIG. 2 is a block diagram of a computer processor system suitable for the graphics processing unit rendering of outline fonts and other equivalent vector based objects.
[0010] FIG. 3 is a flow diagram of the graphics pipeline 201 , including input contributed by a graphics processing unit, or geometry processing unit.
[0011] FIG. 4 is an illustration of a two contour outline font.
[0012] FIG. 5 is an illustration of the two contour outline font triangulated together with implied on-curve points.
[0013] FIG. 6 is an illustration of the mapping of a canonical curve element from texture space to screen space.
[0014] FIG. 7 is a process flow diagram showing the preprocessing process of rendering of outline fonts.
[0015] FIG. 8 is a process flow diagram showing the rendering process of rendering of outline fonts.
[0016] Like reference numerals are used to designate like parts in the accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The detailed description provided below in connection with the appended drawings is intended as a description of the present embodiments of the invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the functions of the invention and the sequence of blocks for constructing and operating the invention in connection with the illustrated embodiments. However, the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.
[0018] Although the present invention is described and illustrated herein as being implemented in a True Type™ system, the system described is provided as an example and not a limitation. As those skilled in the art will appreciate, the present invention is suitable for application in a variety of different types of outline font or vector based font systems. Those skilled in the art will also realize that the present invention may also be applied to the generation of any type of vector based graphics.
[0019] An exemplary embodiment of the present invention is directed to a resolution independent method of rendering outline fonts. The invention may be applied to the rendering of TrueType™ fonts, PostScript™ fonts, vector fonts, and vector graphics. The exemplary embodiments of the invention utilize the programmable pixel shader capability of graphics processing units (GPU). Those skilled in the art will appreciate that the application of the techniques described may be applied to other equivalent processors, including high performance central processing units (CPUs), mainframe computers, DSPs, and the like that provide similar functionality.
[0020] In the conventionally produced font images, curved outlines of a font may not appear curved at all viewing distances and resolutions. For example, the letter “O” may appear to be a square at some resolutions. The present invention tends to provide a resolution independent method of rendering the outlines in outline fonts. This approach uses an in-out test to determine if a pixel belongs to the interior or exterior of the screen space projection of the font outline. This test is based on a relationship between the parametric and implicit form of a rational quadratic curve.
[0021] FIG. 1 illustrates the display of vector drawn images and bit mapped images. Those skilled in the art will appreciate that bit mapped objects are made up of a collection of pixels that are stored and displayed. When enlarging these bit mapped objects the image appears grainy 101 since the number of pixels is fixed. When a bit mapped image is displayed on a high dot per inch (“DPI”) monitor 102 , instead of a conventional monitor 103 , the resulting object may be too small to see 104 . However, bit mapped images are typically easy to display and tend not to be demanding on a CPU used to generate them.
[0022] Vector based objects are drawn from a mathematical description and tend to scale better than bit mapped images. When a vector based image is enlarged 105 it tends to look as good as the original image, since the number of pixels is increased accordingly. Similarly, when a vector based image is displayed on a high DPI monitor 106 its size and appearance 108 appear similar to that when displayed on a conventional monitor 107 . However, vector based objects tend to take more processing than a bit mapped image.
[0023] A vector based image may be any shape that can be generated from a mathematical description. For example outline fonts are vector based and generated from a description of the curves that make up the type face being generated. A description of an outline font may include information giving the number of contours making up the letter, and the definition of the points on each contour. Additional information may also be added to the description, including identification of points that actually lie on the curve and those that do not.
[0024] Texture mapping is used to warp a raster image of the font according to the perspective viewing transformation. Pixilation artifacts appear if the font is viewed too closely. Additionally, the size of these texture images might be large if these artifacts are attempted to be avoided. In the approach utilized these drawbacks tend not to be present as the pixel shader is used to determine shape boundaries.
[0025] FIG. 2 is a block diagram of a computer processor system suitable for the graphics processing unit rendering of outline fonts and other equivalent vector based objects. Computers, game consoles, computing systems and the like may include an auxiliary processor called a GPU 202 . GPU stands for “Graphics Processing Unit.” Like the CPU (Central Processing Unit) 201 , the GPU may be a single-chip processor.
[0026] In an exemplary computing system a CPU 301 is coupled with a GPU 202 including the capability of rendering of vector based fonts, or objects 207 . In the computing system the GPU 202 with rendering of vector based fonts, or objects 207 may be programmed to accept data and commands from the CPU 201 . A memory 203 is coupled to CPU 201 and GPU 202 with rendering of vector based fonts, or objects 207 . The memory 203 provides storage and buffering to the CPU 201 and GPU 202 with rendering of vector based fonts, or objects 207 as needed. The GPU with rendering of vector based fonts, or objects 207 includes an internal graphics pipeline that is coupled via an external conventional graphics pipeline 201 that is typically utilized to transmit graphical information to a display device 208 .
[0027] The GPU is used primarily for computing 3D functions including lighting,effects, object transformations, and 3D motion. Because these types of calculations may be rather taxing on the CPU, the GPU can help the computer run more efficiently. The use of a GPU in conjunction with a central processing unit (“CPU”) can improve overall computing system performance.
[0028] In particular objects may be displayed as bit mapped objects or vector based objects. In typical computer systems bit mapped objects have been used in the past, due to processor limitations. With the advent of the processing power of GPUs better displays tend to be produced with vector based objects.
[0029] In an embodiment of the invention GPU rendering of vector based fonts may be used in the graphics layers of a computer operating system (“OS”) to render vector based shapes. In a computer system such an operating system would tend to improve the display of objects, such as icons, that have been traditionally displayed as bit mapped objects. Such a computer system having a high resolution display, or the equivalent would tend to provide a more visually appealing, and flexible approach to the display of objects on the display device. Those skilled in the art would realize that such a computer system equipped with a display device having a conventional resolution would tend to benefit from such a GPU rendering of vector based objects such as outline fonts, vector drawn icons and the like.
[0030] The embodiments tend to provide a resolution independent method of rendering the outlines of vector based fonts or objects using the programmable pixel shader capability of a graphics processing unit (GPU). The embodiments utilize an “in or out” test to determine if a pixel belongs to the interior or exterior of the outline of a character in the particular font. Or as is known to those skilled in the art whether a pixel belongs on the interior or the exterior of the outline of a screen space projection of the font outline. The in or out test is based on a relationship between the parametric and implicit form a rational quadratic curve. Using the pixel shader to determine if a pixel belongs to a font outline tends to be resolution independent, and has a compact geometric representation.
[0031] The rendering of a font may thus be achieved by using the GPU to evaluate an implicit function for the purpose of region filling as will be explained below. For rendering fonts integral quadratics may be utilized. However rational quadratics may be utilized to render other shapes including circles and ellipses.
[0032] Resolution independence means that curved outlines of the font will appear curved at any viewing distance; a qualitative improvement over existing techniques. Prior to rendering, a font outline is triangulated into a small, fixed set of triangles that depend only on the design of the outline geometry, not its rendered image. The in-out test requires only a few floating operations that can be carried out independently over several pixel processing units in parallel.
[0033] Computer input 205 to the CPU 201 is provided by conventional methods, including keyboards and the like. The CPU 201 may utilize one or more peripheral devices (in addition to memory 203 ), including storage 206 to load and, or store data and instructions. Storage may include magnetic disks, CDs, tapes and the like.
[0034] Those skilled in the art will realize that storage devices utilized to store program instructions can also be distributed across a network. For example a remote computer may store a tool such as the adaptive instrumentation runtime monitoring and analysis software. A local or terminal computer may access the remote computer and download a part or all of the software to run the program. Alternatively the local computer may download pieces of the software as needed, or distributively process by executing some software instructions at the local terminal and some at the remote computer (or computer network). Those skilled in the art will also realize that by utilizing conventional techniques known to those skilled in the art that all, or a portion of the software instructions may be carried out by a dedicated circuit, such as a DSP, programmable logic array, or the like.
[0035] FIG. 3 is a flow diagram of the graphics pipeline 201 , including input to the graphics pipeline contributed by a graphics processing unit, or geometry processing unit (“GPU”) 202 and the GPU Rendering 207 . Typically computer graphics are generated by assembling polygons, including triangles to form a desired image. Graphics hardware for rendering outline fonts may include a programmable pipeline that tends to speed the rendering of natural looking shapes assembled from the polygons. In rendering graphics the programmable pipeline utilizes output from the conventionally constructed vertex shaders (not shown) and The pixel shaders 305 that includes the GPU rendering of graphics and fonts 207 . As will be appreciated by those skilled in the art, a conventional vertex shader program executes on each vertex of a conventional graphics primitive, while a pixel shader program tends to execute on every pixel of a rasterized triangle. That is the pixel shader function provides a place in the font or graphics rendering process where the GPU rendering process 207 may be applied to control the rendering of individual pixels.
[0036] In the conventional operation the data encapsulated in a vertex may be a user defined collection of floating point numbers, much like a “c” data structure. The vertex shader program, or process, can modify this, or invent new data, and pass the result along to a pixel shader. The input to a pixel shader may be an interpolation of the vertex data on the vertices of a triangle. This interpolation of vertex data tends to be non-linear, involving a projective transform that maps a triangle from the model in the computer to the image displayed on the screen, or equivalent display device.
[0037] Accordingly at block 303 the conventional process of triangle setup and rasterization have typically been performed utilizing conventional techniques known to those skilled in the art. At block 304 rendering texture blending, and filtering is typically performed that include contributions from the GPU rendering process 207 . The GPU process 202 includes contributions from the sub-processes of pixel shading 305 , and vertex shading (not shown).
[0038] The pixel shader unit 305 is where computations to produce a final displayed image can occur. The pixel shader units can be active in the processing of an image to be displayed, where control over individual pixels may be exerted. For example in the GPU 202 the pixel shader 305 can be configured to be preceded by a vertex shader that may calculate and provide light source orientation information that may, in turn, be used by the pixel shader to calculate per pixel lighting.
[0039] The pixel shading sub-process 305 includes conventional pixel shading processes 306 , and contributions from an embodiment of the GPU rendering of vector based fonts (“GPU rendering”) 207 . In alternative embodiments GPU rendering may include GPU rendering of outline fonts, or GPU rendering of other objects suitable for vector based definition. Returning to block 304 , the output of this block is the signal to be displayed 308 . The input to block 308 is typically an array of pixels.
[0040] FIG. 4 is an illustration of a two contour outline font 400 . The font outline consists of a set of ordered contours 401 , 402 ; each contour represents a cyclic component of the character. With clockwise ordering, all of the interior of an outline is to the right of the contour path. Those skilled in the art will appreciate that here the path has been arbitrarily divided into an inside and an outside region, with the right side of the contour being considered to be the inside. The path may be encoded by a collection of 2D points in model space, each point is either on-curve 403 or off-curve 404 . On curve points create sharp discontinuities; off-curve points are treated as quadratic B-spline control points, allowing for smoothly curved portions of an outline.
[0041] FIG. 5 is an illustration of the two contour outline font triangulated together with implied on-curve points 500 . At the midpoint 501 between adjacent off-curve points 502 , 503 , lies an implied on-curve point 501 corresponding to the endpoints of the Bézier representation of the underlying quadratic curve. The font outline together with the implied on-curve points are triangulated subject to the constraint that each off-curve point 502 and pair of adjacent on-curve points 501 , 504 forms a triangle. This constraint insures that each quadratic Bézier curve segment 509 lies entirely in the triangle formed by its Bézier control points 502 , 501 , 504 and has endpoints 501 , 504 . The triangles are either entirely on the interior 505 of the font outline 507 , or they contain a curve segment 506 . Those triangles that contain a curve segment 506 , 508 are rendered using a pixel shader program that implements the in-out test.
[0000] The In or Out Test
[0042] The in or out test is applied to the quadratic Bézier curve segments (for example 508 ) laying within the control points (for example 501 , 502 , 504 ) having the parametric form:
B i ( t )= b i−1 (1− t ) 2 +2 b i (1− t ) t+b i+1 t 2 , (0.1)
[0043] where t∈[0, 1], and b i corresponds to an off-curve point (for example 502 , also b i of FIG. 6 ), b i−1 and b i+1 correspond to adjacent on-curve points (for example 501 and 504 , and also b 0 and b 2 of FIG. 6 ). Note that B i (t) is only defined when b i is an off-curve point, and it is assumed the implied on-curves belong to the outline.
[0044] The outline points b i are transformed from the mathematical model to the display, or screen space via a projective transform P. Projective transform P may be represented by a 3×3 matrix. It may be that P is the composition of several standard graphical transforms that involve 4×4 matrices. But ultimately the mapping from model to screen space may be a projective mapping between two dimensional spaces.
[0045] Screen space, or display, points q i =p i ·P are also found. Where outline points p i ={p i,x , p i,y , 1} and display points q i ={q i,x , q i,y , q i,w }. Coordinate curves {q x (t), q y (t), q w (t)} are found according to Equation (1.1), then the curve segment outline takes rational quadratic form:
Q i ( t ) = { q i , x ( t ) q i , w ( t ) , q i , y ( t ) q i , w ( t ) } ( 0.2 )
[0046] in pixel coordinates. The in or out test involves evaluating the implicit form of q i (t). Those skilled in the art will appreciate that an implicit equation in x and y may be considered to be one whose values fall on a given curve in the x-y plane
[0047] Finding the implicit form of a rational quadratic curve involves the resultant of a pair of polynomials. Let
a ( t )= a 0 +a 1 t+a 2 t 2 (0.3)
and
b ( t )= b 0 +b 1 t+b 2 t 2 (0.4)
[0048] be a pair of polynomials in t. These polynomials will have a common root t, if Bezout's resultant |A|=0, where
A = [ a 2 b 1 - a 1 b 2 a 2 b 0 - a 0 b 2 a 2 b 0 - a 0 b 2 a 1 b 0 - a 0 b 1 ] ( 0.5 )
[0049] The implicit form of a quadratic curve is found by forming two new polynomials:
a ( t )= xq w ( t )− q x ( t ) (0.6)
b ( t )= yq w ( t )− q y ( t ) (0.7)
[0050] and taking their resultant. The zero set of the resulting equation in x and y is the implicit form of q(t).
[0051] In order to find such an implicit form for each font outline curve segment in screen space, the matrix A is formed and its determinant is taken. This result would be a quadratic polynomial in two variables x and y, represented by 6 coefficients. The evaluation of this polynomial can include 6 multiplications and 5 additions for each pixel. This may not be considered an unreasonable amount of work. However, current pixel shader implementations tend not to offer an opportunity to set state at triangle set-up time. This means that the implicit form of a quadratic curve would need to be computed at each pixel; while possible, this would tend to be computationally expensive.
[0052] FIG. 6 is an illustration of the mapping of a canonical curve element 601 from texture space 602 to screen space 603 . Rather than finding the implicit equation of each curve segment in screen space 604 , texture coordinates are associated with each triangle vertex b 1 , b 2 , b 3 , and the implicit equation of the curve in texture space 601 is evaluated. Those skilled in the art will appreciate that texture coordinates are typically used in the mapping of a texture on to a triangle. They create a mapping from texture space to the plane defined by the points of a triangle. The following canonical texture coordinates b 0 ←{−1, 1}, b 1 ←{0, −1}, and b 2 ←{1, 1}, are assigned as shown. Those skilled in the art will realize that other texture coordinates may be selected in alternative embodiments. The canonical coordinates tend to act as a template in the derivation.
[0053] In texture space, the cononical curve segment has the form:
{ x,y }={2 t− 1,(1−2 t ) 2 } (0.8)
[0054] t∈[0,1]. By inspection, note that
y=x 2 (0.9)
[0055] Subtracting y from both sides of this equation, gives the implicit form of the canonical curve segment
f ( x,y )= x 2 −y. (0.10)
[0056] It is easily verified that
f (2 t− 1,(1−2 t ) 2 )=0 (0.11)
[0057] Which is the desired result. Those skilled in the art will appreciate that other equations may be used in place of equation (1.10) in alternative embodiments. Since all triangles that contain a curve segment have the same texture coordinates, there is only one implicit equation to serve as an in/out test for the pixel. For the implicit curve those skilled in the art will realize that a pixel for which f(x,y)=0 lies on the curve, a pixel for which f(x,y)<0 lies inside the curve, and a pixel for which f(x,y)>0 lies outside the curve.
[0058] Canonical texture coordinates to the vertices of triangles that contain curve segments are assigned. In this way, the triangle rasterizer will compute the inverse mapping from screen space pixel to texture space point. Since this texture space domain is identical for each triangle containing a curve segment, only one implicit Equation (1.16) need be considered. This expression is evaluated for each interpolated texture coordinate to determine if the pixel is in or out the font outline.
[0059] There are two types of triangles that contain curve segments; corresponding to triangle orientation, or the sign of (v 0 −v 1 )×(v 2 −v 1 ) in model space. This tells if the curve segment is locally convex or concave. This result is encoded as an additional field in the vertex data. Pixels that are inside the curve outline are shaded by combining the in/out test with the triangle orientation (convex or concave). Those pixels that fail this test are outside the outline and write no data to the image or depth buffers.
[0060] The constraint that curve segment triangles must belong to the triangulated font outline may result in artifacts due to triangle overlap. To remove triangle overlap artifacts, curve segments may be subdivided and re-triangulate until no such overlaps exits. Anti aliasing may be provided using methods of pixel super sampling. However, more efficient techniques may be implemented utilizing variants of the current invention.
[0061] FIG. 7 is a process flow diagram showing the preprocessing process of rendering of outline fonts. At block 701 a font outline is loaded. At block 702 the Bézier control points are added to the font outline. At block 703 the outline of the font is formed into triangles utilizing the previously added control points. At block 704 the triangles are classified as either convex, concave, or interior. At block 705 the results are forwarded to the rendering process.
[0062] FIG. 8 is a process flow diagram showing the rendering process of rendering of outline fonts. The results from block 705 of FIG. 7 are input to the font rendering process 800 . At block 801 an inquiry is made to determine if the particular triangle is interior. At block 802 Interior triangles have their pixels filled. If a triangle is not an interior triangle then the in or out test is applied to the pixels of the triangle at block 803 . At block 804 an inquiry is made to determine if a pixel is inside. At block 806 interior pixels are filled. If the pixel is not in the process bypasses block 805 , and proceeds to block 806 .
[0063] At block 806 the process determines if there are more pixels. If there are the process goes back to block 803 . If there are no more pixels the rendering of that particular triangle is ended. The rendering process 800 is repeated until all of the triangles that make up a particular font outline are rendered, and the font is displayed. | Rendering an outline font. Rendering an outline font by adding Bezier control points to further define a contour of an outline font and applying an in or out test to determine if a pixel falls within the contour of an outline font. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS AND PUBLICATIONS
[0001] This application claims priority from U.S. provisional patent application 61/662,603 and 61/690,210 both filed Jun. 21, 2012. The full content of the said applications and of all other patents, published patent applications and non-patent publications cited herein are incorporated herein by reference as though set out at length herein.
FIELD OF THE INVENTION
[0002] The present invention relates to improved methods for production of copper from copper sulfide concentrates produced as part of a mineral ore refining.
BACKGROUND OF THE INVENTION
[0003] De Re Metallica by Georgius Agricola, published in 1556, details the mining, smelting, and refining techniques and technologies of that era. Since then the basic chemical reactions to produce copper have not significantly changed, while the modern smelting process now treats a concentrate rather than as-mined ore of that time. However, technology has markedly advanced through numerous changes and improvements to copper smelting methodology since De Re Metallica's publication. The “Welsh” process, based on a series of sequential reverberatory smelting steps, subsequently dominated copper smelting for over a hundred years. In the 1890s, Nicholls and James developed a process (Great Britain Patent 18,898) based on an alternative final step in the traditional “Welsh” copper smelting process. In this invention part of the high-grade white metal stream was diverted for calcination to produce a copper oxide material for subsequent re-use in the oxidation of the main white metal stream to produce metallic copper. The large, fuel-fired reverberatory furnace was later used for concentrate smelting throughout the first three-quarters of the twentieth century. In more modern times, newer flash and bath smelting processes were developed. The flash smelting concept was described by Bryk et al. in U.S. Pat. No. 2,506,557. Later, Gordon et al described a variant of the flash smelting process in U.S. Pat. No. 2,668,107. An alternative to flash smelting is the bath smelting process such as introduced by McKerrow et al. in U.S. Pat. No. 4,005,856 and also Bailey et al. in U.S. Pat. No. 4,504,309. Still another bath smelting approach, referred to as the Isasmelt process, based on a top lance blowing system with the particular lance system described by Floyd in U.S. Pat. Nos. 3,905,807 and 4,251,271, was developed. The lance system is used in the process operating in Arizona as described by Bhappu et al in: EPD Congress 1994, Edited by G. Warren, The Minerals, Metals and Materials Society, 1993, pages 555 to 570. Each of the contemporary processes described above for the modern era produce a medium to high-grade of copper matte which is typically processed in Peirce-Smith converters to blister copper. Following this, the produced copper is transferred to an anode furnace (European Patent 0648849 B2) for finishing to anode copper for subsequent casting and thence to electrolytic refining. The conventional flash furnace and converter process flow sheet is depicted in FIG. 1 . As shown here, copper concentrate is introduced into the flash smelting furnace (as an example of a modern smelting unit) where the copper sulfide concentrate react with oxygen-enriched air to form a medium grade of matte and a slag. The reaction in the flash furnace can be represented by the following equation (Equation 1). Some nitrogen will also be present with the oxygen, depending on the degree of oxygen enrichment.
[0000]
2
CuFeS
2
+
13
4
O
2
=
Cu
2
S
+
1
2
FeS
+
3
2
FeO
+
5
2
SO
2
Δ
H
o
=
-
250
Wh
(
1
)
[0000] A fossil fuel may be used as a supplementary energy source as required for heating/sustaining typical flash temperatures above 1350° C. A silica flux is added during this step to flux with the iron oxide product shown in Equation (1). The resulting flash furnace slag is sent to a slag treatment facility for copper recovery. The process off-gases are first cleaned and are then treated in a sulfuric acid plant for sulfur recovery.
[0004] The remaining molten white metal is transferred to a converter, where it is blasted with oxygen-enriched air to remove remaining sulfides, produce the blister copper, and form an additional slag (Equations 2 and 3).
[0000] Cu 2 S+O 2 =2Cu+SO 2 ΔH°=−59 Wh (2)
[0000] FeS+1.5O 2 =FeO+SO 2 ΔH°=−130 Wh (3)
[0000] The converter slag is typically higher in copper content, and also requires slag treatment. The flue gases from this step also require processing in the sulfuric acid plant. The copper melt is sent to anode casting (often proceeded by an anode furnace to further purify the copper metal) and then on to electrolysis.
[0005] In total, this flash process has gained wide-spread acceptance in the copper industry. Its advantages over older reverberatory molten bath smelting are manifold: utilization of the heat released during oxidation of sulfides with oxygen, high furnace throughput, high copper recovery into matte, and higher SO 2 content in the off gas relative to the molten bath process. However, and as previously mentioned, significant control must be maintained throughout the process and significant opportunities for improvement exist. Principally, the composition of the feed materials must be well specified, an understanding of the absolute and relative particle sizes is required, moisture and sulfide contents of the concentrates and fluxes must be quantitatively known, and furnace dimensions and temperatures are critical. Precise control over the feed ratios and rate of oxygen injection must be maintained. Similarly, the amount of siliceous flux that must be added is wholly dependent on the sulfide concentrate and the amount of iron that must be oxidized; high copper losses into the slag are still observed and this requires a separate treatment step. The energy demands of the flash process require preheating of the furnace to circa 900-1100° C. to initiate the exothermic reactions involved when oxygen enrichment is not used. This high temperature conversion leads to NO, formation. Oxygen-enriched air is normally used, in which case preheating the air is not common.
[0006] Several variations on flash smelting technology have been developed since the Gordon et al. first work. U.S. Pat. Nos. 5,662,730; 3,790,366; 3,948,639; 3,892,560; 4,615,729; 4,470,845; 3,674,463; 5,607,495; 4,521,245; and US Published Patent Application 2005/0199095 demonstrate oxygen enrichment of air, various techniques for copper recovery from slags as well as partial or dead roasting of the sulfide concentrate prior to flash smelting.
[0007] Work performed in the 1890s by Thomas Davies Nicholls, et al. (Great Britain patent 18,898) details the use of copper oxides in roasting copper mattes to copper metal. During this time period, pneumatic copper converting was just in its infancy, hence this method was considered an improvement over the established contemporary roasting process. Copper (I) sulfide, previously smelted into matte (76-78% copper), is crushed and melted in a reverberatory furnace common at that time with calcined copper. The produced copper was then poled to produce a final copper. In this process, it was difficult to produce CuO during the calcination of Cu metal, so Cu 2 O was used. Production of copper anodes from copper sulfide sources without producing an intermediate copper matte phase has been performed and summarized in the literature 1,2 . In such operations, the copper sulfide concentrate is first dead roasted at elevated temperatures (900° C.) in an excess of oxygen to produce a copper calcine with sulfur levels around 2% (generally 1-1.5% sulfur). The calcine is then transferred to an electric furnace (e.g. the Brixlegg Process) 3,4 , a segregation furnaces 5,6 , a rotary furnace 7 , or a shaft furnace 8,9 where it is further converted to produce blister copper, slag and SO 2 off gases. 1 Opie W R, (1981) Pyrometallurgical processes that produce blister grade copper without matte smelting. IMM, 137-140. 2 (1980) Dead Roast-Shaft Furnace copper smelting, World Mining, Vol 33, Issue 12, 40-41. 3 Kettner P, Maelzer C A, and Schwartz W H, (1972) The Brixlegg Electro-Smelting Process Applied to Copper Concentrates, AIME Annual Meeting, San Francisco. 4 Paulson D L, Worthington R B, and Hunter W L, (1976) Production of Blister Copper by Electric Furnace Smelting of Dead-Burned Copper Sulfide Concentrates, U.S. Bureau of Mines, RI-8131. 5 Opie W R, and Coffin L D, (1974) Roasting of Copper Sulfide Concentrates Combined with Solid State Segregation Reduction to Recover Copper, U.S. Pat. No. 3,799,764. 6 Pinkney E T, and Plint N, (1968) Treatment of Refractory Copper Ores by the Segregation Process, Transactions of AIME, Vol 241, 373-415. 7 Rajcevic H P, Opie W R, and Cusanelli D C (1978) Production of Blister Copper in a Rotary Furnace from Calcined Copper-Iron Concentrates, U.S. Pat. No. 4,072,507. 8 Rajcevic H P, Opie W R, and Cusanelli D C (1977) Production of Blister Copper Directly from Dead Roasted-Copper-Iron Concentrates Using a Shallow Bed Reactor, U.S. Pat. No. 4,006,010. 9 Opie W R, Rajcevic H P, Querijero E R, (1979) Dead Roasting and Blast-Furnace Smelting of Chalcopyrite Concentrates, Journal of Metals, Vol 31, Issue 7, 17-22.
[0008] It is an object of the present invention to provide a better method to recover copper from copper sulfide concentrates via a process chemistry previously unused by the copper smelting industry. This process is referred to as the “Looping Sulfide Oxidation” (or “LSO”) process.
SUMMARY OF THE INVENTION
[0009] Many of the opportunities for improvement in flash smelting outlined above stem from the incremental removal of sulfur in two separate processing steps. As a result, the concentrations of the SO 2 streams, which while higher than the concentrations in the roaster and reverberatory furnace off gases (ca. 15-20% SO 2 ), the presence of two sulfurous off gas streams requires handling and treatment, and slags with relatively high copper contents are produced in both the flash furnace and the converter. The Looping Sulfide Oxidation process for copper production removes sulfur in a single step while using copper oxides (Cu 2 O and CuO) as oxidizing agents to either replace or augment oxygen (O 2 ) from natural air without producing a matte phase. Reference herein to copper oxide oxidizing agents include copper carbonates, sulfates and other oxygen containing copper compounds thermodynamically suitable for use in the Looping Sulfide Oxidation process following the guidelines shown in this application.
[0010] Looping Sulfide Oxidation features three distinct steps: conversion of the copper sulfide concentrates into copper and copper oxides (wholesale desulfurization), recovery of copper from the slag, and looping oxide regeneration ( FIG. 2 ). This process primarily uses CuO as the oxidizing agent instead of O 2 in order to eliminate oxygen-enriched air utilization in the sulfur removal step and to generate energy from the reoxidation of copper downstream. Looping Sulfide Oxidation allows for greater energy capture by performing all the desulfurization of concentrates in a single step. Metal refining and slag treatment are handled simultaneously in the second step. Overall copper yield matches well with recovery levels achieved in the conventional flash process.
[0011] In this first step of the Looping Sulfide Oxidation process, the copper concentrate is blended with fluxes and the oxidizing agent, CuO. In alternative embodiments, the CuO may be augmented with oxygen from air in a fashion such that the total stoichiometry of the system is maintained. The reaction that takes place in this furnace is presented below.
[0000]
CuFeS
2
+
aCuO
+
(
5
-
a
2
)
O
2
→
(
1
+
a
)
Cu
+
FeO
+
2
SO
2
(
4
)
[0000] In such a reaction scheme, the value of a is allowed to vary such that ratio of CuO to O 2 might range from 5:0 to minimal CuO with greater portions of O 2 while still satisfying the reaction stoichiometry. While the relative ratio of CuO and O 2 is important, the total amount of oxidizer may be equal to or in excess of the amount required to completely oxidize the copper concentrate. Consideration must be made that excess of the oxidizer can influence the copper melt and/or slag compositions. In this sense, CuO functions to oxidize the iron in the concentrate and/or slag in addition to oxidizing (desulfurizing) the copper in the concentrate. A fraction of copper will be present in the slag as Cu 2 O due to the equilibrium established between the slag and the copper metal phase. As such, the calculated stoichiometry of the oxidizing agents is minimal, and will be exceeded.
[0012] One possible embodiment of the furnace is a Vanyukov-type furnace 10,11 (exemplars of which appear in U.S. Pat. Nos. 4,252,560 and 4,294,433), i.e. the concentrate and fluxes are added through the slag, which is agitated by the injection of N 2 , hot combustion products, and/or air through tuyères; additionally, the energy is supplied via electrodes submerged in the slag. Due to the high energy demand of the endothermic reaction that takes place, additional heat must be provided to the first furnace. This heat will be supplied either solely through the electrical heating of the furnace or through electrical heating augmented by combustion of fuels, whose heat will be transmitted to the furnace through the hot gases in the tuyères and whose chemically inert combustion product gases will be injected into the molten slag to facilitate mixing. Another embodiment may use a top-blown lance in the slag in an Isasmelt-type furnace; this embodiment may also include electrode heating. 10 Bystov, V P, Fyodorov, A N, Komkov A A, and Sorokin M L (1992) The use of the Vanyukov process for the smelting of various charges, in Extractive Metallurgy of Gold and Base Metals, Australasian Institute of Mines and Metallurgy, Pardville, Vic., 477-482. 11 Bystrov, V P, Komkov A A, and Smimov L A (1995) Optimizing the Vanyukov process and furnace for treatment of complex copper charges, in Copper 95- Cobre 95 , Vol. IV—Pyrometallurgy of Copper , ed. Chen W J, Diaz C, Luraschi A, and Mackey P J, The Metallurgical Society of CIM, Montreal, Canada, 167-178.
[0013] The process chemistry that takes place in the first furnace is of critical importance. Most notably, metal not matte is formed during this step. This marks a significant differentiation and improvement over the present state of the art. The molten copper metal produced in the furnace is very low in iron and is sent directly to the anode furnace. The oxidized iron slag contains copper that must be recovered during slag treatment. As previously mentioned, the complete desulfurization of the concentrate is accomplished in this single step. This allows for significant energy capture during sulfuric acid production in an acid plant. Additionally, because no sulfurous/sulfuric gases will be produced in the downstream processing, aggressive energy capture can be performed on the off gases without fear of acid condensation. The major differences between this invention and the closest prior art (Nicholls et al.) are:
1. The raw material is neither blister copper nor matte, but is rather copper sulfide concentrate 2. The raw material and copper oxide are simultaneously fed into the molten slag in the smelting furnace; the slag is agitated via the injection of combustion product gases or chemically inert gases 3. The use of oxygen is controlled and special care is taken to ensure that the total oxygen from air and copper oxide does not exceed 20% excess of the required stoichiometric amounts.
Slag composition in the smelting step can be further optimized by changing the amounts of fluxes (CaO, SiO 2 , Al 2 O 3 ) added to reduce the viscosity, lower the melting temperature, and increase copper recovery into the copper melt. Increased calcium oxide will decrease the copper solubility in the slag. The amount of Fe 2 O 3 (i.e. the amount of Fe 3+ ) in the slag must be reduced.
[0017] During slag treatment, the goal is to recover as much copper as possible from the slag phase so that it can be returned to the processing loop for copper anode production. In general, the slag from the first furnace will contain ca. 10-15% copper in the slag as Cu 2 O. The slag, which is still molten, is treated with either carbon (from coal or natural gas) to reduce the copper oxides to copper metal (and the trivalent iron to divalent iron), or oxidized with sulfur (e.g., as iron pyrite), to produce copper matte. With carbon reduction the copper from the slag treatment furnace can be mixed with the copper rich material from the smelting furnace; with sulfidation, the matte will be returned to the smelting furnace to be reprocessed.
[0018] Slag treatment must reduce the copper content in the waste slag to levels below ca. 0.4 weight percent. The copper solubility in the slag is a function of many variables; one of critical importance is the Fe(III):Fe(II) ratio. In this process, the copper solubility in the slag is reduced (and thereby the copper recovery is increased) by significantly reducing the Fe(III) content in the slag. Additionally, when the product from slag treatment is copper metal, the iron content must be sufficiently low enough for an anode furnace. In the process presented here, the copper metal from the slag treatment step is blended with the copper metal from the first furnace to produce a copper-rich stream to be processed in the anode furnace. If sulfidation is performed, the copper matte produced will be processed in the first furnace. This step in the process is carried out in a traditional slag treatment furnace, e.g. an electric furnace.
[0019] The anode furnace operates in the same fashion as conventional anode furnaces. The copper melt is first oxidized to oxidize any residual iron to a dry slag; in this step some of the copper metal may be co-oxidized. The slag is tapped off and the remaining copper melt is then deoxidized prior to casting to anodes ready for electrolytic refining.
[0020] The fraction of copper that is sent to electrolysis is determined by the stoichiometry of the reaction in the smelting furnace (i.e. the amount of copper in the concentrate is equal to the amount of copper in the anodes for electrolysis). The necessary amount of copper to produce the requisite copper oxide for oxidation of the copper concentrate is sent to the reoxidation furnace. In this furnace, the copper melt is atomized and oxidized to CuO with air. This highly exothermic reaction can be harnessed for energy capture. The molten copper is oxidized at high temperatures in a downer or vertical furnace (ca. 1500° C.), and cooled below freezing to ca. 800° C. The powdered CuO is then looped back to the smelting furnace to complete the reaction cycle.
[0000] 2Cu+O 2 →2CuO ΔH 1500° C. =−59.5 Wh (5)
[0000] This invention provides an improvement over the closest prior art wherein Cu 2 O was produced (Nicholls et al.) in which copper matte is oxidized to produce copper oxide. In this work, copper is reoxidized after atomization to promote rapid and complete oxidation.
[0021] Alternatively, other sources of copper oxides can be used as oxygen carriers during Looping Sulfide Oxidation. For example, CuO is used in the industry as pigments in ceramic materials, battery materials and catalysts. These materials can be fed to the smelting furnace to augment the copper oxides that are produced in the reoxidation furnace. Similarly, several copper oxide minerals are processed by the copper industry; these minerals can be used as source of copper oxides during Looping Sulfide Oxidation. Thermodynamic calculations, made with FactSage 6.4 12 thermodynamic software, detailing such operation are disclosed below. 12 Bale, C. W., et al., FactSage™ 6.4.1, Thermfact and GTT-Technologies, CRCT, Montreal, Canada (2013).
[0022] Copper scrap is also an important copper stream for Looping Sulfide Oxidation. Copper scrap metals and copper alloy scrap can be processed in Looping Sulfide Oxidation via either smelting in the smelting furnace in the presence of copper oxides (potentially augmented with air), or via initial oxidation to copper oxides in the reoxidation furnace. In the former embodiment, the copper scrap is melted in the smelting furnace and converted to copper metal in the same fashion as copper concentrate. Depending on the composition of the scrap, alloyed metals will report to either the slag or the copper phase. The use of this embodiment can gain an increase in the iron content in the molten copper due to the reduction of the iron oxides present in the slag with any reducing metals (e.g. aluminum or silicon) present in the scrap. In the latter embodiment, the copper scrap is processed to enable its rapid atomization and oxidation (in one embodiment, in a plasma furnace) to copper oxides that can be looped to the smelting furnace.
[0023] Other objects, features and advantages will be apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 (Prior Art) shows in block diagram form a generalized process flow chart for flash smelting conversion;
[0025] FIG. 2 shows in block diagram form a Looping Sulfide Oxidation Process to produce anode copper;
[0026] FIG. 2 a shows schematically an electric arc furnace used in the smelting conversion;
[0027] FIGS. 3-8 are traces of thermodynamic data showing calculations of production conditions (CuO) feed variation on output conditions of the copper melt and slag during the smelting step;
[0028] FIGS. 9-15 show traces of thermodynamic data detailing the slag treatment and output of the slag treatment furnace, the treated slag and the copper melt or copper matte;
[0029] FIGS. 16-19 show traces of thermodynamic data detailing the smelting of CuFeS 2 with CuCO 3 ; and
[0030] FIGS. 20-22 show traces of thermodynamic data detailing the smelting of CuFeS 2 with CuSO 4 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Example 1
[0031] In the present analytical example (not based on a physical plant actually constructed) the process is described on a production basis of approximately 1000 kg of anode copper. The process flow (all or parts of which can be continuous, semi-continuous or batch format) is shown in FIG. 2 and the preferred basic configuration of the electric furnace (an arc furnace) is shown in FIG. 2 a including tuyères for gas injection into a molten slag formed in the furnace.
Electric Furnace
[0032] A room temperature copper concentrate comprising 3000 kg CuFeS 2 , 173.4 kg FeS 2 , and 294.8 kg gangue (CaO, Al 2 O 3 , SiO 2 ), preferably in free flowing powder form, is to be mixed with 7400 kg of CuO at 800° C. in the first smelting furnace (Table 1). Heat and material balances were calculated using HSC 7.1 Chemistry for Windows thermochemical software 13 . Silica (1000 kg) and lime (500 kg) fluxes are also taken as to be added to the melt. The melt is to be heated to 1300° C. via electrical and/or combustion heating. The reaction produces a metallic copper melt, an oxidized slag, and a rich SO 2 gas stream. In this Example, 14% excess CuO is used to produce an optimal copper melt and an optimal slag ( FIGS. 3 , 4 , and 5 ). The copper melt is 98.8% copper with 0.002% Fe, and 0.88% S ( FIG. 6 ). The slag includes some copper oxide (as Cu 2 O), iron oxides and gangue and flux derivatives. All compositions herein are weight percent unless otherwise noted. 13 Roine, A., et al., HSC 7.11, Outotec, Pori, Finland (2011).
[0033] As discussed in the above Summary of the Invention, the copper solubility in the slag is largely dependent on the degree of oxidation of the iron also present in the slag. The fluxes added to the furnace are designed to aid in slag formation and produce a low melting, fluid slag. The slag produced in this Example melts at 110° C. with a viscosity of 2.0 poise (at 1300° C.). The Cu 2 O content in the slag is 13.2%, and requires treatment to recover as much of this copper as possible ( FIG. 7 ). FIG. 7 demonstrates that during smelting, the copper content in the slag is largely independent of the slag composition and operating temperature. However, as shown in comparing FIGS. 8 and 9 , the dramatically higher O 2 partial pressure above the slag in the electric furnace as compared to the O 2 partial pressure above the slag in the slag treatment furnace leads to different slag chemistries. Most notably, the decreased copper solubility in the slag after slag treatment can be explained by considering the lower oxygen partial pressure present in the treatment furnace. This demonstrates that the copper content in the slag can be controlled by the oxygen partial pressure.
[0000]
TABLE 1
Electric Furnace Heat & Material Balance
Temperature
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Cu Concentrate
25.000
18.853
3468.198
0.855
0.00
−2180.49
CuFeS2
25.000
16.348
3000.000
0.714
0.00
−864.48
FeS2
25.000
1.445
173.400
0.035
0.00
−71.56
CaO*Al203*2SiO2
25.000
1.060
294.798
0.107
0.00
−1244.44
Recycled CuO
800.000
93.029
7400.000
1.173
1025.04
−3040.27
CuO
800.000
93.029
7400.000
1.173
1025.04
−3040.27
Flux
25.000
25.559
1500.000
0.534
0.00
−5783.49
SiO2
25.000
16.643
1000.000
0.385
0.00
−4211.01
CaO
25.000
8.916
500.000
0.150
0.00
−1572.47
Heating
25.000
47.972
1243.806
888.658
0.00
0.00
C
25.000
8.326
100.000
0.044
0.00
0.00
O2(g)
25.000
8.326
266.412
186.609
0.00
0.00
N2(g)
25.000
31.320
877.394
702.005
0.00
0.00
Energy Required
2493.56
OUTPUT
Copper Melt
1300.000
105.915
6607.987
31.555
1449.45
1544.56
Cu
1300.000
102.724
6527.713
0.729
1417.28
1417.28
Fe
1300.000
0.003
0.142
0.000
0.03
0.03
S
1300.000
1.814
58.147
0.028
21.91
21.91
O(g)
1300.000
1.374
21.985
30.799
10.22
105.33
Slag
1300.000
47.844
3596.867
0.940
1233.75
−7504.18
Al2O3
1300.000
1.059
108.020
0.027
44.85
−448.28
SiO2
1300.000
18.759
1127.114
0.434
461.01
−4285.28
CaO
1300.000
9.973
559.294
0.167
178.67
−1580.27
FeO
1300.000
11.671
838.491
0.140
240.41
−641.78
Fe2O3
1300.000
3.057
488.235
0.093
154.03
−547.63
Cu2O
1300.000
3.325
475.714
0.079
154.79
−0.93
Flue Gas
1300.000
73.419
3407.221
1645.574
1143.46
−2551.06
SO2(g)
1300.000
33.772
2163.415
756.960
634.42
−2150.05
CO2(g)
1300.000
8.326
366.412
186.609
152.67
−757.38
N2(g)
1300.000
31.320
877.394
702.005
356.37
356.37
[0000]
TABLE 2
Slag Treatment Furnace Heat & Material Balance
Temperature
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Slag Furnace
Slag
1300.000
47.844
3596.867
0.940
1233.75
−7504.18
Al2O3
1300.000
1.059
108.020
0.027
44.85
−448.28
SiO2
1300.000
18.759
1127.114
0.434
461.01
−4285.28
CaO
1300.000
9.973
559.294
0.167
178.67
−1580.27
FeO
1300.000
11.671
838.491
0.140
240.41
−641.78
Fe2O3
1300.000
3.057
488.235
0.093
154.03
−547.63
Cu2O
1300.000
3.325
475.714
0.079
154.79
-0.93
Reductant
25.000
4.329
52.000
0.023
0.00
0.00
C
25.000
4.329
52.000
0.023
0.00
0.00
S
25.000
0.000
0.000
0.000
0.00
0.00
Energy Required
76.99
OUTPUT
Copper Melt
1300.000
6.573
417.129
0.053
90.67
90.68
Cu
1300.000
6.498
412.946
0.046
89.66
89.66
Fe
1300.000
0.075
4.179
0.001
1.01
1.01
O(g)
1300.000
0.000
0.004
0.006
0.00
0.02
Treated Slag
1300.000
47.430
3080.021
0.843
1054.22
−7298.04
Al2O3
1300.000
1.059
108.019
0.027
44.85
−448.28
SiO2
1300.000
18.759
1127.126
0.434
461.01
−4285.33
CaO
1300.000
9.973
559.297
0.167
178.68
−1580.28
FeO
1300.000
17.416
1251.250
0.209
358.75
−957.71
Fe2O3
1300.000
0.147
23.551
0.004
7.43
−26.42
Cu2O
1300.000
0.075
10.778
0.002
3.51
−0.02
Flue Gas
1300.000
4.330
151.739
97.040
62.79
−219.84
CO(g)
1300.000
2.425
67.932
54.358
27.86
−46.60
CO2(g)
1300.000
1.904
83.807
42.682
34.92
−173.23
[0034] The SO 2 stream produced during the smelting step is sent to an acid plant for sulfuric acid production. The SO 2 content of the off gas in this Example is 46%. Significant energy can be captured during sulfuric acid production, and this energy can be used to improve the overall energy balance of the Looping Sulfide Oxidation process.
Slag Treatment
[0035] The slag produced in the electric furnace (3.0% Al 2 O 3 , 31.3% SiO 2 , 15.5% CaO, 23.3% FeO, 13.6% Fe 2 O 3 , 13.2% Cu 2 O) is transferred to an electrical furnace at 1300° C. for slag treatment (Table 2). In this Example the 3596.9 kg of slag is treated with 52 kg of carbon to reduce Fe 2 O 3 and Cu 2 O. By reducing the trivalent iron, the solubility of copper in the slag is dramatically reduced. As a result, a copper melt is formed with 97.7% of the copper recovered (417.1 kg melt, 98.997% Cu, 1.0% Fe) ( FIGS. 10 and 11 ). The remaining slag contains only 0.35% Cu 2 O and is fit for disposal as waste (melting temperature, 1070° C.; viscosity 1.7 poise at 1300° C.) ( FIGS. 12 and 13 ). The copper melt produced during slag treatment is blended with the copper melt from the electric furnace to produce a copper stream (7025.1 kg, 98.798% Cu, 0.062% Fe, 0.828% S, 0.313% O) for treatment in the anode furnace.
[0036] The heat required to perform the slag treatment will be provided by electrical heating via the electric furnace. Natural gas for combustion heating can also be provided via tuyères.
Downer Reoxidation Furnace
[0037] In a downer furnace, molten copper is atomized and oxidized in situ to fine. particulate CuO. Atomizing the molten copper minimizes mass transfer limitations between the molten copper and the oxygen and leads to near 100% conversion to CuO. This highly exothermic reaction provides significant potential for energy capture. It is understood that molten CuO is highly corrosive, so following oxidation cool air is introduced to solidify the CuO. The CuO is thus cooled down to 800° C. before it exits as a fine particulate and is recycled back at temperature to the first furnace. Looping of this material in this system at temperature and at high processing speed enhances the overall energy balance of the process.
[0038] The flue gases are sent to an air/air heat exchanger, where the reaction air for the downer furnace and anode furnace are preheated to 400° C. in order to maximize the thermal efficiency. The flue gas is then sent to a boiler where a significant portion of the energy is captured as high pressure steam.
[0000]
TABLE 3
Reoxidation Heat & Material Balance
Temperature
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Reoxidation
Copper
1300.000
93.105
5915.483
0.862
1284.49
1285.11
Cu
1300.000
93.029
5911.598
0.660
1283.51
1283.51
Fe
1300.000
0.066
3.676
0.000
0.89
0.89
O(g)
1300.000
0.009
0.144
0.202
0.07
0.69
S
1300.000
0.002
0.065
0.000
0.02
0.02
Reaction Air
400.000
221.497
6390.255
4964.539
690.25
690.25
O2(g)
400.000
46.514
1488.402
1042.553
150.10
150.10
N2(g)
400.000
174.982
4901.853
3921.986
540.15
540.15
OUTPUT
Copper Oxides
1243.850
46.514
6661.065
1.109
1421.58
−502.52
Cu2O
1243.850
21.882
3131.100
0.522
585.95
−438.94
Cu2O(1)
1243.850
24.600
3520.000
0.587
832.15
−57.68
Cu2O*Fe2O3
1243.850
0.033
9.965
0.000
3.48
−5.90
Flue Gas
1243.850
198.197
5644.748
4442.302
2161.41
2161.24
N2(g)
1243.850
174.982
4901.853
3921.986
1895.51
1895.51
O2(g)
1243.850
23.212
742.764
520.270
265.86
265.86
SO2(g)
1243.850
0.002
0.131
0.046
0.04
−0.13
[0000]
TABLE 4
Quench Cooling of Reoxidation Products
Temperature
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Reoxidation-
Quench Cooling
Copper Oxides
1243.850
46.514
6661.065
1.109
1421.58
−502.52
Cu2O
1243.850
21.882
3131.100
0.522
585.95
−438.94
Cu2O(1)
1243.850
24.600
3520.000
0.587
832.15
−57.68
Cu2O*Fe2O3
1243.850
0.033
9.965
0.000
3.48
−5.90
Flue Gas
1243.850
198.197
5644.748
4442.302
2161.41
2161.24
N2(g)
1243.850
174.982
4901.853
3921.986
1895.51
1895.51
O2(g)
1243.850
23.212
742.764
520.270
265.86
265.86
SO2(g)
1243.850
0.002
0.131
0.046
0.04
−0.13
Cooling Air
25.000
528.256
15240.366
11840.122
0.00
0.00
N2(g)
25.000
417.322
11690.618
9353.697
0.00
0.00
O2(g)
25.000
110.934
3549.748
2486.426
0.00
0.00
OUTPUT
Copper Oxides
800.000
93.029
7405.274
1.172
1026.09
−3046.62
CuO
800.000
92.996
7397.400
1.172
1024.68
−3039.20
CuO*Fe2O3
800.000
0.033
7.874
0.000
1.41
−7.42
Flue Gas
800.000
703.196
20140.911
15761.146
4705.52
4705.35
N2(g)
800.000
592.305
16592.471
13275.683
3927.10
3927.10
O2(g)
800.000
110.889
3548.310
2485.418
778.39
778.39
SO2(g)
800.000
0.002
0.131
0.046
0.02
−0.15
[0039] In this Example, 7400 kg of CuO are required in the electric furnace. As such, 5911.1 kg of molten Cu must be oxidized in the downer reoxidation furnace; the remaining 1020.5 kg of Cu can be sent to electrolysis for final purification (Tables 3 and 4). In the downer reoxidation furnace a significant excess of air will be used to ensure complete reoxidation.
[0040] Energy is captured during this step by using the flue gases from the reoxidation furnace to (1) preheat the oxidation air and (2) produce high pressure steam in a boiler after preheating.
Energy Balance
[0041] The two primary energy producing steps in the Looping Sulfide Oxidation process are the sulfuric acid production in the acid plant and the reoxidation of the Cu to CuO before it is looped back to the electric furnace. The acid plant per se, is outside the scope of this invention; however, as it is known to those skilled in the art, state-of-the-art processes like the Lurec® process have been shown to capture significant portions of the total energy available during sulfuric acid production 14 . On this basis, we have evaluated the energy balance of the Looping Sulfide Oxidation process relative to conventional copper processing. 14 Daum K H, The Lurec® Process—Key to Economic Smelter Acid Plant Operation, in The Southern African Institute of Mining and Metallurgy Sulfur and Sulfuric Acid Conference 2009, 1-22.
[0042] During conventional copper processing, the only major energy producing step is the acid production. It is estimated that the theoretical total amount of energy that can be produced during this step is 54.7 Wh per mole of CuFeS 2 processed.
[0000] 2SO 2 +O 2 →2SO 3 ΔH 600° C. =−54.7 Wh (6)
[0000] In this analysis, production of sulfuric acid is estimated to result in the production of 2462 kg of high pressure steam (100 bar, 350° C.) per 1000 kg of Cu produced during heat capture in boilers and cooling jackets (Tables 5 and 6).
[0000]
TABLE 5
Acid Plant Boiler Heat & Material Balance
Temperature
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Acid Plant System-
Boiler 1
Gas from Smelting
1300.000
73.419
3407.221
1645.574
1143.46
−2551.06
SO2(g)
1300.000
33.772
2163.415
756.960
634.42
−2150.05
CO2(g)
1300.000
8.326
366.412
186.609
152.67
−757.38
N2(g)
1300.000
31.320
877.394
702.005
356.37
356.37
Gas from Anode
1200.000
50.173
1437.869
1124.550
580.51
−561.04
Furnace
N2(g)
1200.000
35.269
987.991
790.495
367.09
367.09
SO2(g)
1200.000
1.810
115.964
40.575
31.08
−118.18
O2(g)
1200.000
0.003
0.082
0.057
0.03
0.03
NO(g)
1200.000
0.001
0.026
0.019
0.01
0.03
SO3(g)
1200.000
0.001
0.052
0.015
0.02
−0.06
H2O(g)
1200.000
8.273
149.040
185.428
108.08
−447.65
CO2(g)
1200.000
3.849
169.393
86.270
64.33
−356.39
CO(g)
1200.000
0.514
14.407
11.528
5.41
−10.38
H2(g)
1200.000
0.453
0.914
10.163
4.46
4.46
Cooling Water
25.000
89.461
1611.655
1.617
0.00
−7098.80
H2O(100 barl)
25.000
89.461
1611.655
1.617
0.00
−7098.80
OUTPUT
Gas to Scrubbing
400.000
123.591
4845.090
2770.123
465.76
−4370.31
SO2(g)
400.000
35.583
2279.379
797.534
171.29
−2762.43
CO2(g)
400.000
12.175
535.805
272.879
55.58
1275.20
N2(g)
400.000
66.589
1865.385
1492.500
205.55
205.55
O2(g)
400.000
0.003
0.082
0.057
0.01
0.01
NO(g)
400.000
0.001
0.026
0.019
0.00
0.02
SO3(g)
400.000
0.001
0.052
0.015
0.00
−0.07
H2O(g)
400.000
8.273
149.040
185.428
30.33
−525.40
CO(g)
400.000
0.514
14.407
11.528
1.62
−14.17
H2(g)
400.000
0.453
0.914
10.163
1.37
1.37
High Pressure
350.000
89.461
1611.655
2005.140
485.79
−5840.59
Steam
H2O(100 barg)
350.000
89.461
1611.655
2005.140
485.79
−5840.59
[0000]
TABLE 6
Catalyst Bed Heat & Material Balance
Temperature
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Catalyst Bed
Post-Scrub Gas Stream
80.000
114.346
4680.570
2562.913
59.08
−4205.41
SO2(g)
80.000
35.583
2279.379
797.534
22.29
−2911.43
N2(g)
80.000
66.589
1865.385
1492.500
29.65
29.65
CO2(g)
80.000
12.175
535.805
272.879
7.14
−1323.64
Reaction it
25.000
93.193
2688.636
2088.781
0.00
0.00
O2(g)
25.000
19.570
626.230
438.644
0.00
0.00
N2(g)
25.000
73.622
2062.406
1650.137
0.00
0.00
Cooling Water
25.000
47.217
850.633
0.853
0.00
−3746.75
H2O(100 barl)
25.000
47.217
850.633
0.853
0.00
−3746.75
OUTPUT
Catalyzed Gas
225.000
189.748
7369.206
4252.926
373.05
−4869.49
SO3(g)
225.000
35.583
2848.680
797.534
114.14
−3797.62
N2(g)
225.000
140.211
3927.791
3142.636
228.08
228.08
CO2(g)
225.000
12.175
535.805
272.879
27.84
−1302.94
O2(g)
225.000
1.779
56.930
39.877
2.98
2.98
High Pressure Steam
350.000
47.217
850.633
1058.314
256.40
−3082.67
H2O(100 barg)
350.000
47.217
850.633
1058.314
256.40
−3082.67
[0043] Therefore, with all other factors being equal, conventional copper processing and Looping Sulfide Oxidation processing would theoretically produce equal amounts of energy during sulfuric acid production. However, as the Lurec® process states, the higher the strength of the SO 2 stream, the greater the energy production; therefore, it can be expected that, in practice, the Looping Sulfide Oxidation process would actually produce more energy than the conventional process due to its high strength SO 2 stream. However, if equal energy production is assumed in the acid plant, the only major differentiating factor in energy production will be during the reoxidation of the copper to CuO, which the conventional process does not perform. During reoxidation, the amount of high pressure steam (100 bar, 350° C.) that is estimated to be produced is 4049 kg per 1000 kg of Cu produced (Tables 7 and 8).
[0000]
TABLE 7
Reoxidation Reaction Air Preheater Heat & Material Balance
Temperature
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Reoxidation Heat
Recovery-Air
Preheater
New Reaction Air
25.000
266.141
7678.264
5965.184
0.00
0.00
O2(g)
25.000
55.890
1788.402
1252.689
0.00
0.00
N2(g)
25.000
210.252
5889.862
4712.495
0.00
0.00
Reoxidation Flue
800.000
703.196
20140.911
15761.146
4705.52
4705.35
Gases
N2(g)
800.000
592.305
16592.471
13275.683
3927.10
3927.10
O2(g)
800.000
110.889
3548.310
2485.418
778.39
778.39
SO2(g)
800.000
0.002
0.131
0.046
0.02
−0.15
OUTPUT
New Reaction Air
400.000
266.141
7678.264
5965.184
829.38
829.38
O2(g)
400.000
55.890
1788.402
1252.689
180.35
180.35
N2(g)
400.000
210.252
5889.862
4712.495
649.02
649.02
Reoxidation Flue
671.626
703.194
20140.780
15761.101
3875.97
3875.97
Gases
N2(g)
671.626
592.305
16592.471
13275.683
3235.65
3235.65
O2(g)
671.626
110.889
3548.310
2485.418
640.32
640.32
SO2(g)
671.626
0.000
0.000
0.000
0.00
0.00
[0000]
TABLE 8
Reoxidation Boiler Heat & Material Balance
Temperatur
Amount,
Amount,
Amount,
Latent
Total
©
kmol
kg
Nm3
H, kWh
H, kWh
INPUT
Reoxidation Heat
Recovery-Boiler
Reoxidation Flue
671.626
703.194
20140.780
15761.101
3875.97
3875.97
Gases
N2(g)
671.626
592.305
16592.471
13275.683
3235.65
3235.65
O2(g)
671.626
110.889
3548.310
2485.418
640.32
640.32
SO2(g)
671.626
0.000
0.000
0.000
0.00
0.00
Cooling Water
25.000
224.748
4048.881
4.061
0.00
−17833.96
H2O(100 barl)
25.000
224.748
4048.881
4.061
0.00
−17833.96
OUTPUT
Reoxidation Flue
150.000
703.194
20140.780
15761.101
715.05
715.05
Gases
N2(g)
150.000
592.305
16592.471
13275.683
600.31
600.31
O2(g)
150.000
110.889
3548.310
2485.418
114.73
114.73
SO2(g)
150.000
0.000
0.000
0.000
0.00
0.00
High Pressure
350.000
224.748
4048.881
5037.413
1220.43
−14673.04
Steam
H2O(100 barg)
350.000
224.748
4048.881
5037.413
1220.43
−14673.04
[0044] Taking into consideration the total estimated energy output during Looping Sulfide Oxidation, the amount of energy available for capture during the reoxidation of the molten copper is approximately 1.64 times greater than the amount available for capture during sulfuric acid production alone. This comparison is vital because during conventional processing, significant energy consumptions and productions have been observed at different processing facilities 15 . Therefore, on the basis of potential energy available for capture, the Looping Sulfide Oxidation process provides significant improvements over the conventional technology; the increased energy production drastically mitigates the net energy consumption during copper processing. 15 Coursol P, Mackey P J, and Diaz C M (2010) Energy Consumption in Copper Sulphide Smelting, in Proceedings of Copper 2010, 1-22.
Example 2
[0045] Using the same feed conditions and smelting furnace parameters as those presented in Example 1, the slag produced in the smelting furnace can be treated in the slag treatment furnace by sulfidation. During sulfidation, iron pyrite (FeS 2 ) is added to the molten slag to sulfidize the copper, causing it to separate out of the slag into a copper matte ( FIGS. 14 and 15 ). In this scheme, the copper recovery from the slag ranges from 99 to 96% in the temperature range of 1200-1400° C. The slag has a melting temperature of 1120° C. and a viscosity of 0.709 poise at 1300° C. The treated slag is fit for disposal as waste. The copper matte, which is now rich in copper sulfide, must be processed in the smelting furnace again before the copper can be sent to the anode furnace as blister copper.
Example 3
[0046] Copper sulfide concentrate (CuFeS 2 ) is smelted with CuCO 3 to produce copper metal, iron oxide slag, and rich SO 2 off gas ( FIGS. 16-18 ). In such a reaction, 3000 kg of CuFeS 2 (with 173.4 kg of FeS 2 and 294.8 kg of CaAl 2 Si 2 O 8 ) is reacted with 11500 kg of CuCO 3 and 1000 kg of SiO 2 and 500 kg of CaO between 1200° C. and 1400° C. The products of this reaction will include an off gas that is comprised mainly of CO 2 and SO 2 ( FIG. 19 ). At 1300° C., 6654 kg of molten Cu will be produced containing 0.30% S, 0.21% O and 0.0028% Fe. The 3490 kg of slag produced contains 10.7% Cu 2 O.
Example 4
[0047] Copper sulfide concentrate (CuFeS 2 ) is smelted with CuSO 4 to produce copper metal, iron oxide slag and rich SO 2 off gas ( FIG. 20-22 ). In such a reaction, 3000 kg CuFeS 2 (with 173.4 kg FeS 2 , 294.8 kg CaAl 2 Si 2 O 8 ) is reacted with 7423 kg CuSO 4 and 1000 kg SiO 2 and 500 kg CaO between 1200° C. and 1400° C. The products of this reaction will include an off gas that is comprised of SO 2 that is diluted with any combustion gases or inert gases. At 1300° C., 3658 kg of molten copper will be produced containing 1.1% S, 0.33% O and 0.0025% Fe. The 3559 kg of slag produced contains 12.3% Cu 2 O.
[0048] It will now be apparent to those skilled in the art that other embodiments, improvements, details, and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents. | Copper is produced by a looping oxidizing process wherein oxidation of copper sulfide concentrate to molten blister copper by conversion with copper oxides (and optionally oxygen from air) in a one step, molten bath operation to produce molten blister copper, iron oxide slag, and rich SO 2 off gas. The blister copper is treated in an anode furnace to reduce the iron content and oxidize residual sulfur, and prepare it for either electrolysis or reoxidation. | 2 |
FIELD OF THE INVENTION
The present invention relates to a manually controlled atomizer-doser device of the type comprising a mechanical pump with a piston and plunger providing the suction of a liquid to be atomized which is delivered to a spray nozzle. Embodiments of such devices are described in particular in EP-A-0,025,224 and FR-A-2,374,536.
BACKGROUND OF THE INVENTION
In a general way, such atomizer-doser devices are designed in particular for the dispensing of liquid or viscous products, in small doses, for example samples of perfumes or of cosmetics or of pharmaceutical products.
In the devices of this type known at present (U.S. Pat. No. 4,050,860 and FR-A-2,374,536), the body which comprises the mechanism of the pump has to be mounted on the receptacle containing the liquid to be atomized through the intermediary of a bushing or the like having a triple function:
assembly and mounting of the body onto the receptacle by coupling of the inner diameter of this bushing onto the outer diameter of the neck of the receptacle;
closure of the body while retaining the mechanism of the pump with piston which is subject to the force of a return spring and;
creation of a leaktight connection between the atomizer-doser system and the neck of the receptacle with, if required, the interposition of a seal for leaktightness.
This bushing, at present considered essential by the person skilled in the art in order to constitute the atomizer-doser assembly, may be constructed in various forms of execution such as, in particular, bushings to be screwed, bushings to be crimped, sleeves to be snapped home and other types of bushings of known types.
Although the use of such a bushing proves satisfactory in the context of conventional applications for atomizer-doser devices delivering doses smaller than 50 μl, it has, in the case of adaptation to small receptacles and/or small apertures, major disadvantages, in particular:
a bulky geometry which stands in the way of a miniaturization of the atomizer-doser device and also of the receptacle on which it is mounted and which contains the liquid to be dispensed;
an extra production cost, due to the presence of the bushing which constitutes an additional component and which requires an assembly operation which is also additional, this extra production cost being of course unacceptable in the case of mass production applications, particularly for samples of perfumes where a low cost price is sought.
BRIEF DESCRIPTION OF THE INVENTION
The present invention therefore proposes to provide an atomizer-doser device which does not have the abovementioned disadvantages of the solutions according to the prior art and which makes it possible to dispense with precision very small doses varying, for example, between 35 and 45 μ.
To this end, the invention relates to an atomizer-doser system for liquid or viscous products comprising a pump of the mechanical type with a piston positioned in a receptacle containing the product to be dispensed, wherein the body of said pump is force-fitted into the neck of the receptacle, the upper part of said body terminates with a collar which abuts against the neck and means are provided on said body in order to ensure the escape of air from the receptacle when the body is fitted therein, a vent hole made in the body opening onto said means.
According to the invention, the vent hole can be placed under a step of the body which is provided between the upper cylindrical part of the latter, force-fitted into the neck of the receptacle and its lower part of small diameter. According to a variant, the means for ensuring the escape of air during the fitting operation consist of a groove made in the outer cylindrical surface of the pump body onto which groove the vent hole opens.
According to another feature of the present invention, the atomizer-doser system comprises a sleeve force-fitted into the upper part of the body, this sleeve terminating at its upper part with a collar abutting against the collar provided on said body.
According to the invention, the lower part of the piston of the pump is provided with a skirt which has an annular lip which, at rest, is maintained under a radial stress, said lip being wedged between a collar, provided at the lower end of the piston, and the interior of the pump body, the vent hole possibly being provided under the lip of said skirt.
Other features and advantages of the present invention will become apparent from the description given below with reference to the accompanying drawings, in
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a view to a large scale, in longitudinal axial cross section, of an atomizer-doser system according to the present invention and;
FIG. 2 shows the system according to the present invention in partial longitudinal axial cross section.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings, the atomizerdoser device according to the present invention is seen to comprise, in this nonlimitative embodiment, a pump mechanism with piston generally designated by the reference 14 which is positioned on the receptacle 2, generally of glass or of plastic material, containing the product to be atomized, this receptacle being surmounted by an internally smooth and cylindrical neck 7. At its upper part, the pump with piston 14 is provided with a dispensing push-button 1.
According to the present invention, the body 3 of the mechanism of the pump is fitted inside the neck 7 of the receptacle, as is clearly seen in the drawing. This body 3 is here extended all in one piece, in its lower part, by an extraction tube 6 which is flush, as known, with the bottom of the receptacle 2. The upper part of the body 3 terminates with a collar 12 which abuts against the neck 7 of the receptacle 2. Over a height compatible with good retention of the body 3 and which is here slightly greater than the internal height of the neck 7, the outer part of this body is cylindrical and smooth and is gripped inside the neck 7, as can be seen in the figures. A seal is therefore produced by the fit at this level, the pump body corresponding perfectly in shape to the internal diameter of the neck of the receptacle. It will be noted that the pump body 3 may preferably be constructed of injected thermoplastic material of appropriate quality in order to guarantee a seal by conforming under resilient stress to the shape of the inside of the neck of the receptacle.
In this embodiment which is by no means of a limitative nature, the cylindrical part 15 of the body, on which the grip is exerted, is extended by a part 16 of cylindrical shape, the outer diameter of which is considerably smaller than that of the upper part 15 of the body and, in any case, smaller than the internal diameter of the neck. In the embodiment example shown in the drawings, a step 10 is provided between the upper part 15 and lower part 16 of the pump body. A lateral vent hole 9 opens onto the outside, this vent hole being situated under the step 10. The presence of this vent hole makes it possible to ensure a venting of the air pressure which is produced inside the receptacle 2 when the fitting of the pump body onto the neck of the receptacle is carried out. According to one variant, this venting can be obtained by providing an external groove 9A which is made in the cylindrical surface of the pump body and onto which opens said vent hole as shown in FIG. 2.
Inside the pump body, the operating mechanism of the pump tends, under the effect of an internal return spring 17, to return the rod 8 at the end of which is mounted the piston 16 of the pump, this rod being surmounted by the dispensing push-button 1. In order to retain and to position the rod 8 under the action of the return spring 17, a sleeve 4 is provided which is forcefitted inside the body 3 and which is surmounted by a collar 13 which abuts against the collar 12 of the body 3. The retaining of the sleeve 4 in the body 3 can be reinforced by providing coupling means such as 5, for example in the form of catches and grooves engaged in one another and provided respectively on the facing surfaces of the body 3 and of the sleeve 4, as is clearly seen in FIG. 1. In order to ensure a seal, in their top parts, the internal surface of the body 3 and the external surface of the sleeve 4 are smooth and of cylindrical shape and they are gripped together.
The lower part of the sleeve 4 constitutes the top stop of the pump mechanism and this stop positions the high point of the travel of the pump during operation. Consequently, the height of the sleeve 4 constitutes a decisive factor in the dose of products which can be atomized by the device according to the invention.
The dimensions and also the configuration of the sleeve 4 can be selected so that the latter constitutes the covering of the neck of the receptacle.
The rod 8 which, under the action of the pushbutton 1, actuates the mechanism of the pump, slides freely inside the sleeve 4 with a sufficient clearance, as can be seen in FIG. 1.
The action of fitting the pump body inside the neck of the receptacle may be performed by applying a bearing force on the upper part of the dispensing pushbutton 1. It will be noted that because of the absence of the outer bushing which, in the prior state of the art, is essential in order to ensure a seal between the pump body mechanism and the receptacle, the dispensing push-button 1 may be of a diameter greater than that of the collar 13 of the sleeve 4 or of the body 3 of the pump mechanism.
In the absence of any dispensing push-button 1 the force necessary for fitting the pump body onto the neck of the receptacle may be applied on the collar 13.
According to the invention, the depth of the fit is practically equal to the internal height of the neck 7 of the receptacle 2.
The three functions: assembly, closure-retaining of the internal mechanism of the pump and sealing are obtained, according to the invention, in the following manner:
the assembly is durably consolidated by the grip resulting from the fitting of the external diameter of the body 3 into the internal diameter of the neck 7 of the receptacle 2;
the closure of the body in order to retain the mechanism of the pump which is subject to the force of the return spring 17 is ensured by the presence of the sleeve 4 which is force-fitted inside the body and which forms a stop for gripping and for internal sealing. As has been seen above, this sleeve 4 is pushed in until the lower surface of its collar 13 abuts against the upper surface of the collar 12 of the body 3. The retaining of the internal mechanism of the pump body can be improved, as has been seen above, by the presence of coupling means 5, which guarantees the retaining of the sleeve in the body, this sleeve tending to be returned upwards under the action of the return spring 17 and;
the sealing function is of course ensured by virtue of the tight fit of the external diameter of the pump body on the internal diameter of the neck of the receptacle.
According to the invention the sealing of the pump is improved by the following arrangements:
the skirt 19 which, in known manner, is provided at the lower part of the piston 18 of the pump comprises a lip 20 which, at rest, is under radial stress, so as to be maintained wedged between the collar-shaped lower part of the piston 18' and the internal bore of the pump body. This arrangement increases the seal and also makes it possible to reduce the diameter of the pump by avoiding, for example, the construction of an internal member of the second skirt type in order to ensure a seal on the piston. The reinforcement of the flattening of the lip 20 against the pump body is ensured by the action of the spring 17 which presses the piston 18 onto the lip, which produces an effect of wedging of the lip.
the vent hole 9 which, in conventional manner, is provided through the pump body 3 can be positioned under the lip 20, which makes it possible to eliminate any possible leaks between the sleeve 4 and the upper part of the skirt 19, by limiting the paths of leaks, owing to a constant pressure in the receptacle. It will be noted that such a positioning of the vent hole is rendered possible particularly by the fact that the invention is preferably applied to receptacles of small capacity, which limits the actuation of the pump to a few tens of spray actions. Thus, the risks of damage to the lip 20 when it passes the vent hole are limited.
It will be noted that, owing to the arrangement according to the present invention, the pump can operate without a seal system.
The lower part 22 of the piston 18 of the pump is constructed so as to provide a double function: the centering of the spring 17 and the end-of-travel stop against the ball 25 provided, in conventional manner, in the extraction tube 6 at the upper part of the latter. During the fitting, when the base of the piston comes to a stop against the ball, it blocks the latter thus preventing any rising of the liquid at the time of the slight overpressure due to the fitting action.
The operation of this pump is similar to that of the piston-type pumps of atomizer-doser devices according to the above-mentioned prior state of the art and will not be described again. It will, however, be noted that the passage of the liquid into the channel 23 of the pump body, and via the transverse channel 24 can take place equally by deformation or by lifting of the skirt 19.
Among the advantages provided by the invention, the following can be cited in particular:
obtaining in a simple and inexpensive manner the coupling of the pump body onto the receptacle containing the product to be atomized, this coupling being produced with the smallest possible bulk, in contrast with the conventional coupling system requiring bushings, as has been seen above;
possibility of mounting on sample tubes. The handling of a sample tube in order to actuate an atomizer-doser system mounted at its end is very tricky, and the invention makes it possible to construct a pump having a very flexible operation, which allows this mounting;
the increased seal produced by means of the invention makes it possible to dispense very small doses, which increases the adaptability of the system according to the invention to sample tubes the capacity of which is very small (of the order of 1 to 2 cm 3 ), which necessitates the presence of a perfectly leak light pump, failing which the contents of the sample tube may be reduced, or even disappear, within a few weeks.
The device according to the present invention is preferably applied to receptacles of small capacity intended particularly for the market of the sampling of perfumes and cosmetics. As a nonlimitative example, the body of the pump may have a diameter of 5 mm compatible with a tight fitting of this body inside the necks of receptacles of drawn glass manufactured for this use, but which at present are closed by a simple stopper which renders the use of such sample tubes impractical. The device according to the invention can therefore be substituted for the current stoppers of these sample tubes making it possible to provide a sprayed release of the sample of perfume or a release in "blob" form for products of viscous consistency, particularly cosmetic products such as gels, oils, creams or milks. Of course, the invention can be applied to receptacles of larger capacity and to necks of greater diameter.
It remains clearly understood that the present invention is not limited to the examples of embodiments and/or of applications described and mentioned here but that it encompasses all variants thereof. | A cylindrical pump body is axially disposed in a container and has an annular shoulder sealingly abutting an outer end of the container neck opening. The wall of the pump body is press fit against the interior wall of the container neck. A cylindrical sleeve is telescopingly press fit within an outer end portion of the pump body and has an annular collar sealingly abutting the pump body shoulder. The press fit between these components as well as their abutting annular sections ensures securement of the components within the container as well as the sealing of container contents therein without the use of threaded closures of gaskets. | 1 |
This application is a division of our prior copending application Ser. No. 360,817, filed May 16, 1973, now U.S. Pat. No. 3,811,164, issued May 21, 1974, which was a continuation-in-part of application Ser. No. 293,966, filed Oct. 2, 1972 and now abandoned, which in turn was a continuation-in-part of application Ser. No. 220,947, filed Jan. 26, 1972 and now abandoned.
BACKGROUND OF THE INVENTION
Commercial laundries commonly use power driven rolls usually known as flatwork ironers. Frequently four or more power driven rolls are used in a single unit of equipment. These rolls are usually covered with asbestos fabric. Such fabric is commonly woven from yarns which are called asbestos yarns although they generally contain a small proportion of staple fiber other than asbestos for the purpose of holding the asbestos fibers in position.
It has heretofore been proposed to treat the asbestos fabric of ironer roll covers with a material to make the work-contacting surface smooth, durable, tough, tear-resistant and wear-resistant. For example U.S. Pat. No. 2,534,818 issued to Holroyd et al. shows the provision of a liner or padding wound around the roll prior to applying an asbestos cover prepared by passing woven asbestos fabric through an aqueous impregnating bath containing a thermosetting resin, such as a melamine-formaldehyde resin, in solution in water together with a thermoplastic resin, such as polymerized methyl methacrylate, and wax in emulsion, drying, calendering and curing whereby the intermingled resins and wax give the fabric a smooth porous surface, good wear-resisting properties and good tear-resisting properties.
Similarly, U.S. Pat. No. 2,033,894 to Crockford shows a flatwork ironer roll comprising a padding layer 6 which may supplement the usual padding or replace it altogether. Layer 6 is preferably made of woven asbestos fabric. Around layer 6 is disposed protective insulating layer 5 which likewise is made from woven asbestos fabric but is provided with resinous impregnation 10 which typically is a heat-hardened phenolic resin material. The cured resinous material imparts to the asbestos roll covering a smooth and indurated surface which does not materially impair the flexible properties of the fabric. Protective covering 5 is shown as a prolongation of the unimpregnated asbestos padding layer 6, the two layers being integrated by lines of stitching 8 which secure the lapped ends together.
U.S. Pat. No. 2,333,824 to Schoepf shows an ironer roll cover unit which comprises a multiply woven fabric pad section 11 adapted to be wrapped around the roll and a single ply inner fabric outer cover section woven with smaller weft threads than the weft threads in the pad section, the two sections being woven as a single unit with common warp thread extending continuously throughout the length of the unit. The weft threads of both sections preferably are asbestos threads and the warp threads likewise preferably are constituted by some form of asbestos thread.
None of the patents referred to in the foregoing teaches the present invention which resides in an ironer roll cover unit comprising a length of fabric having the same construction throughout so that no fabric seam is present, thereby eliminating unevenness and the necessity for seaming, and having a padding portion which constitutes a base layer on the roll and is free from resinous material or other solid material which would materially reduce the padding effectiveness of the padding portion. The roll cover unit of the present invention also embodies a portion which constitutes an outer work-contacting section which is based upon an integral portion of the fabric forming merely an extension of the fabric used in the padding portion. This work-contacting section is formed by impregnating the fabric constituting this portion with a thermosetting resinous material which provides the desired porosity, smoothness, heat resistance, wear resistance and other qualities required in the work-contacting portion of an ironer roll cover. The fabric used for both the padding portion and the work-contacting portion preferably is a woven fabric made with warp and weft yarns both of which contain enough heat-resisting fiber to give a high degree of heat resistance, both warp and weft desirably comprising predominantly or exclusively heat-resisting fibers.
SUMMARY OF THE INVENTION
In its product aspects, the invention comprises an ironer roll cover comprising a single sheet of fabric having a length equal to the length of the ironer roll to be covered and a width sufficient to enable the fabric to be wound a plurality of times around the ironer roll, this fabric having a first longitudinal portion sufficiently wide to enable it to extend for at least one full turn around the ironer roll and having a second parallel longitudinal portion sufficiently wide to enable it to extend for at least one full turn around the first longitudinal portion when the latter is positioned around the roll, the second portion being impregnated with a thermoset resinous material and the first portion being free of resinous material or other solid material which would materially reduce the padding effectiveness, whereby the first portion constitutes a padding for the second portion and the second portion constitutes the work-contacting portion of the cover and has a surface which is smooth, heatresistant and wear-resistant for ironing purposes. In one embodiment the first and second portions of the cover adjoin one another. In another, and preferred embodiment, the first and second portions are separated from one another by a narrow (relative to the widths of the first and second portions) partially impregnated intermediate parallel portion of the same sheet of fabric from which the first and second portions are formed. This intermediate portion provides a transitional zone between the first and second portions on the roll as a result of the feathered edge effect of the intermediate zone which is usually from about 1/4- to 3/4-inch wide and typically about 1/2- inch wide, this effect being due to the significantly lower extent of impregnation of the fabric in the intermediate zone as compared to the work-contacting portion.
In its method aspects, the invention is a method of making an ironer roll cover comprising applying a liquid coating composition containing a thermosetting resinous material, typically in solution in a volatile organic solvent, to a portion only of a single sheet of the fabric base material and thereby effecting selective impregnation of such portion (which is to constitute the work-contacting part of the cover), drying the impregnated fabric to remove volatiles therefrom, curing the resinous material deposited on and through the fabric to thermoset condition, and preferably thereafter calendering the surface of the impregnated portion of the resulting fabric sheet to form a smooth finished work-contacting portion. More specifically, the method comprises a method as just set forth wherein the base fabric initially contains a substantial porportion of water, say 90-100 percent by weight based on the total weight of the fabric, and is dried to remove substantially all of said water prior to being subjected to the impregnating step just described. A preferred method involves the feature of obtaining the aforementioned intermediate portion, which is substantially more flexible than the work-contacting impregnated area of the final product, by applying liquid water on the fabric in a band parallel to and adjacent the area which is to be fully impregnated and which is to constitute the work-contacting surface and also adjacent the unimpregnated area which is to constitute the padding portion. Typically this is achieved by squirting a stream of liquid water onto the fabric in the area which thereafter is adjacent the divider in the conventional impregnating equipment customarily used. This liquid water is injected onto the fabric as it moves towards the impregnating step over an area having a width corresponding to that of the desired intermediate transitional portion and operates in some manner to markedly reduce the amount of impregnating resin the cloth picks up in that area and correspondingly reduce the resin "add-on" (dry weight of resin solids remaining after processing to remove volatiles, based on the weight of the fabric) in that area.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a block diagram of a preferred method used for treating the base fabric in the manufacture of an ironer roll cover of the invention;
FIG. 2 is a perspective view of an ironer roll covered with the cover of the invention;
FIG. 3 is a plan view of three different patterns of ironer roll covers of the invention;
FIG. 4 is a plan view of a modified ironer roll cover of the invention, this cover being characterized by having an intermediate area having less impregnation and therefore giving a feathered edge or transitional effect between the unimpregnated padding or liner portion and the highly impregnated work-contacting portion; and
FIG. 5 is a schematic perspective view of impregnating equipment suitable for making the modified ironer roll cover of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, a sheet of fabric 1, which typically contains a substantial proportion of moisture and may even be wet with liquid water, is fed into a drying oven 5 at 400°F. at a speed of 6 yards per minute, for an exposure time of 22/3 minutes, to remove the water and moisture and preheat the fabric for the impregnating step. Then the fabric passes through coating equipment 6, which usually embodies a conventional spreading knife and a knife edge divider serving to apply a liquid containing a thermosetting resinous material, preferably a phenolic resin material, to only that portion of the fabric which is to serve as the work-contacting surface in the final cover. Techniques for coating or impregnating only a portion of a sheet have long been known in other arts, as shown by U.S. Pat. Nos. 1,206,501 to Bell et al.; 1,571,706 to Carmichael; and 2,766,717 to Neidich et al.
Any suitable liquid thermosetting impregnating material can be used. Solutions of thermosetting resins, especially thermosetting phenolic resins, in volatile organic solvents such as toluene or the like are preferred. The selection of a suitable impregnating liquid is well within the skill of the ironer roll cover art. An example of a composition which has been found eminently satisfactory is one composed of two parts by volume of a material known as "Sterling Thermobond Varnish R740", one part of "Sterling Thermobond Varnish T707" and one part of toluene. The two varnishes referred to are liquid phenolic resins made by Sterling Varnish Company of Szwickley, Pennsylvania.
The fabric used in practicing the present invention can be of any type which is suitable as an ironer roll cover material. Almost invariably it is a woven fabric but it could be a so-called non-woven fabric or a knit fabric. A suitable base fabric is a five harness sateen woven fabric consisting of 18-3 cut asbestos yarn warp and 12-6 cut asbestos yarn filling. This fabric is woven using a 9.70 dent reed with the warp yarns being drawn five ends per dent. This fabric consists of 30.5 ends per inch and 26 picks per inch and is woven 90 inches in width. The weave and other characteristics of the base fabric should be so correlated with the thermosetting resinous impregnating material that the latter will completely permeate or otherwise soak through the asbestos fabric. The base fabric should be one which will not burn or char under the heat of ironing.
The partially impregnated fabric travels from coating equipment 6 through a drying oven 7 which serves to drive off substantially all volatile material from the impregnating composition. The drying oven 7 is preferably at a temperature of 325°F. and the sheet travels through the oven at 6 yards per minute for 31/3 minutes. The impregnating material is tacky as the fabric leaves oven 7. The assembly is now fed through a curing oven 8 which typically is at a temperature of 450°F. and the composite fabric travels through this curing oven for 52/3 minutes at a rate of 6 yards per minute. In the course of passage through the curing oven 8 the thermosetting impregnating material is cured to thermoset condition. The composite fabric is then calendered in a step indicated by reference numeral 9. In the calendering step the composite fabric is calendered by passing it into the nip of a heated polished stainless steel roll and another roll which preferably is a husk-filled roll (typically made of elastomeric material filled with a combination of cotton husks and corn husks). The steel roll is in contact with the surface of the impregnated portion which is to contact the work in service. Preferably the pressure exerted on the fabric by the two rolls of the calender is 650 psi.
In the calendering step the fabric typically is fed around a first husk-filled roll, which acts as a guide roll, then into contact with the stainless steel roll for a contacting arc of about 90°, then through the nip of the stainless steel roll and a second husk-filled roll, and around this latter roll, either into a wind-up zone for subsequent cutting-to-length to make the finished covers or into a cutting zone for such cutting to length.
The reason for using the combination of a steel roll and a husk-filled roll for performing the calendering step is that this combination produces a cover which has a good, smooth hand in its work-contacting portion and does not crush the fabric excessively. The fabric is now smooth and finished in its impregnated portion and ready to be placed upon the roll 10 (FIG. 2) for use in actual service. In FIG. 2, the ironer roll 10 is shown wrapped with the covering of the invention, generally designated by reference numeral 2. The covering consists of the inner padding layer 3 which is formed from the unimpregnated portion of the fabric and an outer workcontacting portion 4 which is formed from the impregnated portion of the fabric. The padding 3 may consist of one or several layers of the unimpregnated fabric wound about roll 10. The longitudinal groove 11 in roll 10 receives the edge of padding portion 3 at the start of the application of the cover. The outer work-contacting portion 4 almost invariably consists of only a single turn around the roll. Roll 10 is usually 124 inches long and one to three inches in diameter.
FIG. 3 illustrates three coverings 2, each having an unimpregnated padding section 3 and an impregnated work-contacting section 4. As can be seen, various widths can be achieved for the impregnated and unimpregnated portions of the cover, depending on the particular requirements. The length, 124 inches, shown in FIG. 2 is the standard length of roll used in commercial flatwork ironers.
The selection of equipment for carrying out the impregnating step will be well within the skill of the impregnating art. Typically a knife-coating or knife-spreading unit will be provided with a divider of conventional well-known type which limits access of the impregnating material to that portion of the base fabric sheet which is to form the work-contacting layer.
FIG. 4 portrays a preferred type of cover of the present invention. The cover 20 shown in this figure comprises an unimpregnated padding portion 21, a fully impregnated work-contacting portion 22, and a narrow intermediate or transitional portion 23 which provides the "feathered edge" effect referred to above and is characterized by impregnation to a much less extent than work-contacting portion 22 so that it creates little or no problems of unevenness when the roll is placed in service.
Cover 20 of FIG. 4 is preferably made in the manner portrayed in FIG. 5. In FIG. 5 the fabric 30, which has been dried to remove water, is fed in the direction indicated by arrow 31 to the impregnating apparatus 32. A stream of water is fed via pipe 33 onto fabric 30 as it is about to enter the impregnation zone, forming a narrow band 34 of water-saturated fabric at an appropriate intermediate point in fabric 30. The portion of fabric 30 which is to be impregnated passes under pool 35 of liquid coating composition replenished via pipe 36 and confined laterally between a dam 37 located at the edge of band 34 next to fabric portion 21 which is to be unimpregnated and a dam 38 at the opposite edge of the impregnated portion of the fabric. The scraper blade 39 prevents excess impregnating material from remaining on the surface of the composite threezone fabric seen at the right of FIG. 5 as it leaves the impregnating equipment. The fabric is then fed to the curing zone and thence to the calendering step.
It will be understood by those skilled in the art that the equipment portrayed in FIG. 5 is illustrative only and that innumerable arrangements of apparatus can be employed to achieve the desired result of impregnation with liquid water along an intermediate zone in the fabric followed by complete impregnation with the resinous composition in the area to form the work-contacting portion and limited impregnation with the resinous composition in the intermediate zone.
EXAMPLE 1
In this example the base fabric was a five harness sateen woven asbestos fabric of the particular type described in detail above and the impregnating formulation consisted of 50 percent "R740 Thermobond Varnish," 25 percent "T707 Thermobond Varnish" and 25 percent toluene. The two types of varnish were combined in a suitable mixing container. The toluene was added last and the entire mixture stirred for about 5 minutes with a rotary mixer. Half width impregnation of the 90 inch wide fabric and a feathered edge transition strip were applied to the fabric in the following way. The fabric was first wet thoroughly with water in a padder which consisted of two dip pans and two rubber rolls with a steel center roll. The fabric was dipped in water in each pan and then padded between a steel roll and a rubber roll using 60 pounds gauge pressure. Next the fabric was passed through a weft straightener device to correct any bow and skew problems in the fabric. Next the face and filling sides of the fabric were brushed with rotating fiber brushes to adjust porosity and remove excess fiber from the face. After brushing, the fabric was tentered and dried using a pin tenter covered with an oven. The oven temperature was 400°F. and the speed of travel of the fabric was 6 yards per minute. The length of the tenter was 60 feet of which 44 feet were covered with the oven.
After emerging from the oven, the fabric was passed against a flat spread coating board and by use of a stainless steel dam the impregnating composition was applied against 51 inches of the total 90 inch wide cloth. Just prior to the application of the resin impregnating solution, a fine stream of water was applied to that portion of the fabric that would form the last one-half inch of the treated portion of the cloth. The purpose of this water application was to reduce the amount of impregnating resin the cloth would pick up in that area, thus creating a more gradual transition from the untreated to the treated sections of the final ironer roll cover. After application of the impregnating solution, the fabric was passed through two scraper rods to remove all excess impregnating solution.
The fabric was then dried in a dryer at 325°F. and then cured in a curing oven at 450°F. Finally, the cloth was calendered between a stainless steel roll and a husk-filled roll using 650 pounds per square inch pressure. After calendering, the fabric was rolled up on a suitable tube for shipment and subsequent cutting to desired lengths to cover ironer rolls.
The weight of the uncoated (greige) asbestos fabric, the weights of the final impregnated fabric in the transition zone and the work area and the percent add-on in the transition zone and the work area of the product resulting from Example 1 are shown in the following tabulation:
Transition Work Greige Zone Area______________________________________Weight (oz./sq.yd.) 22.81 26.57 27.52% Add-on (% of curedresin based onweight of fabric) 16.5% 20.7%______________________________________
The specific proportions of "R740" varnish, "T707" varnish and toluene used in Example 1 were found by experimentation to give a well-cured resin. "R740" varnish by itself develops a very flexible film when baked and shows an undesirably low tendency to harden. On the other hand, T707 varnish bakes out in a relatively shorter time at lower temperatures and forms a hard film; the amount of this type determines the hardness of the final coating, the curing time required, and the physical properties of the plastic film that is formed around the yarns and fibers of the base fabric. The toluene serves as a thinner. A composition based on R740 varnish only would not dry; some T707 varnish appears to be necessary to act as a drying agent; the more of this component used the stiffer the final film will be. An impregnating composition having the particular proportions mentioned above has been found to dry relatively quickly and give the desired flex qualities needed while not being too stiff. Those skilled in the art can readily determine how to formulate thermosetting impregnating compositions which will perform satisfactorily in the practice of the invention. It is not necessary to use the particular formulation described above; on the contrary, almost innumerable formulations can be successfully employed.
While the foregoing example is based on use of an asbestos fabric, we can use any other fabric having the characteristics which are requisite for ironer roll covers, one of the most important of which is adequate heat-resistance and good dimensional stability when exposed to temperatures up to 450°F. for prolonged periods of time, both during the curing step in manufacture of the ironer roll cover fabric and during service on the ironing equipment. Those skilled in the art will at once know, or be able with a minimum of effort to determine, what fabrics other than asbestos fabric would be suitable for use in the practice of the present invention.
Examples of other suitable base fabrics are those made from aromid (not a trademark) fiber which is available commercially in yarn form under the trademarks "Fiber B," "DP-01" and "Nomex." Aromid is the generic name for fiber made from the condensation product of isophthalic or terephthalic acid and m- or p-phenylenediamine. "Fiber B" is generally understood to be a product of the condensation of terephthalic acid and p-phenylenediamine while "Nomex" is understood to be a product of the condensation of isophthalic acid and m-phenylenediamine. Aromid is defined as "a manufactured fiber in which the fiberforming substance is a long-chain synthetic aromatic polyamide in which at least 85 percent of the amide linkages are attached directly to two aromatic linkages."
We have found that fabric made from aromid fiber such as "Nomex" fiber (which is described in du Pont Bulletin N-245 entitled "Yarns and Fabrics of Nomex High-Temperature-Resistant Nylon Staple and Tow" and published March 1971, "Nomex High Temperature Resistant Nylon" published in 1972 by du Pont and in "Chemical Week," July 5, 1972, page 25) is eminently suitable as the base fabric in the practice of the present invention. In addition to its excellent dimensional and chemical stability at temperatures up to 450°F. it is lighter than asbestos and it has been observed that ironer roll covers made in accordance with the present invention from "Nomex" (1) provide a smoother finish, (2) reduce starch build-up in service, (3) reduce drag on the chest of the ironing equipment, (4) withstand shock better, and (5) have longer operating life, all as compared to covers made from asbestos. Another advantage is that they obviate the health hazards incident to the use of asbestos.
EXAMPLE 2
This example illustrates the use of "Nomex" woven fabric in making ironer roll covers in accordance with the present invention.
"Nomex" greige fabric having the specifications set forth in column A of the table below was finished, thereby producing a fabric having the specifications set forth in column A, of the table. The finished fabric was then treated to effect impregnation of the transition zone and work-contacting area with the same phenolic resin impregnating formulation as was used in Example 1 in the same manner as described in that example. The work area had the specifications set forth in column A 2 of the table.
A "Frazier" is a unit of measure indicating the porosity of a fabric in cubic feet/sq.ft./min. (CFM). One Frazier equals one cubic foot of air passing through 1 square foot of fabric in 1 minute. "CC" is an abbreviation for Cotton Count. "Fill." is an abbreviation for filling; textile specialists normally refer to warp yarns and filling yarns.
______________________________________ A A.sub.1 A.sub.2 Unfinished Finished Finished & Uncoated but Uncoated % Coated______________________________________Weave Plain Plain PlainWeight (oz./sq.yd.) 9.6 8.56 12.67Width (in.) 90 90 90Construction 37 × 33 37.5 × 31 41 × 30.7Frazier (CFM) 70 64 13Grab Strength(warp) 390 -- --Grab Strength(Fill.) 360 -- --Yarn Size(warp) 6/1 (CC) 6/1 (CC) 6/1 (CC)Yarn Size 6/1 (CC) 6/1 (CC) 6/1 (CC)______________________________________
The weights of the final impregnated fabric and the percent add-on in the transition zone and the work area of the product resulting from Example 2 were as follows:
Transition Work Zone Area______________________________________Weight (oz./sq.yd.) 11.84 12.67% Add-on (% of cured resinbased on weight offabric) 38.2% 48%______________________________________
Ironer roll covers made from the resulting fabric performed very satisfactorily.
EXAMPLE 3
a "Nomex" woven fabric having the following construction was impregnated in the same manner as in Examples 1 and 2.
______________________________________Weave PlainWeight (oz./sq.yd.) 7.06Width (in.) 90"Construction 39 × 34Frazier (CFM) 46Grab Strength (warp) 360Grab Strength (Fill.) 300Yarn Size (warp) 8/1 (CC)Yarn Size (Fill.) 8/1 (CC)______________________________________
Ironer roll covers made from the resulting fabric gave excellent performance.
GENERAL
It is essential that the final cured workcontacting surface of the cover be porous and pervious to water vapor in order to work properly on the heated ironer roll. In other words, complete coating of the working surface of the roll cover so as to render it completely inpervious, or nearly so, is to be carefully avoided. The factors of porosity of the base fabric, the viscosity and other attributes of the impregnating liquid, and the method of effecting impregnation must all be regulated so as to achieve the desired effect. Those skilled in the art can readily select and determine these and all other factors involved in successfully carrying out the present invention, with a minimum of experimentation.
The amount of thermoset resin deposited on the woven asbestos fabric in the impregnated workcontacting portion of the covers of the invention can vary widely but typically ranges between 15 to 30 percent add-on (percent by weight of cured resin (dry weight) based on the dry wieght of the fabric by itself); the amount of resin in the intermediate or transitional zone likewise can vary widely but typically ranges between 10 and 24 percent add-on.
In the case of covers which are based on woven "Nomex" fabrics, the amount of cured resin deposited in the work-contacting area can likewise vary widely but typically ranges from 30 to 50 percent add-on; in the transitional zone it typically ranges from 20 to 40 percent add-on. | A method of making an ironer roll cover which comprises impregnating a less than full-width longitudinal portion of a sheet of fabric with a liquid thermosetting resin and curing the resin. The unimpregnated portion of the fabric acts as a liner or padding for the impregnated portion, while the impregnated portion serves as the work-contacting surface. Because the liner portion and the work-engaging portion of the cover are integrally formed from a single sheet of fabric, no seam or stitching is required for joining the two portions. Thus, the unevenness caused by a seam is eliminated and manufacturing costs are reduced. In a preferred embodiment, liquid water is applied in a narrow band between the impregnated and unimpregnated sections of the fabric to achieve a less than full impregnation, thereby providing a transitional zone between the liner and the work-contacting portion of the cover. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a pipe clamp, in particular, a pipe coupling, comprising a tightenable clamp body with at least one spike strip arranged radially inwardly within the clamp body and slanted toward the axial center of the clamp body. The spike strip delimits an acute angle between it and the radially inner side of the clamp body and has teeth at one longitudinal edge which teeth project radially inwardly and are slanted axially relative to the clamp body. It is supported in the area of the other longitudinal edge in the radial direction and in the axial direction on the clamp body.
2. Description of the Related Art
Such a clamp serves either for coaxially connecting smooth end sections of pipes and/or as a holding clamp in connection with an additional support or fastening part for attachment on building parts.
When the pipe clamp is used as a pipe coupling, it has at its two axial ends a spike strip arrangement, respectively, wherein each spike strip arrangement is comprised of two or more spike strips. The teeth of the spike strips at the axial ends of the clamp body are facing one another. This has the effect upon tightening the clamp body that the pipe ends cannot easily be pulled apart again.
However, mounting of such a pipe clamp is relatively complex. Tightening of the clamp body must be realized with relatively high precision. Generally, this requires the use of a torque wrench.
SUMMARY OF THE INVENTION
It is an object of the present invention to simplify mounting of such a pipe clamp.
In accordance with the present invention, this is achieved in that the acute angle is free of means counteracting a bending of the spike strip toward the radially inner side of the clamp body.
In other words, the spike strip rests only with one longitudinal edge on the clamp body and projects otherwise freely to the center axis of the clamp body. On the backside of the spike strip delimiting the acute angle between the spike strip and the clamp body there is no element which could act as an abutment for the spike strip. When the clamp body is tightened, the teeth of the spike strip can be pushed radially outwardly. Since the spike strip is elastically yielding in a certain way, this results in a certain spring action. The teeth and the pipe ends accordingly are engaged with increasing grip the tighter the clamp body is tightened. Moreover, the slanted teeth ensure that the two pipe ends with increasing tightening of the clamp body and the resulting diameter reduction of the clamp body are moved toward one another and can approach one another with a certain predetermined force. At the same time, an adaptation to different diameters of the two pipe ends is possible. The spike strip at the pipe end with the greater diameter is adjusted more with regard to its contact angle. Since the spike strip is without abutment on its backside, it can be unimpededly pushed or bent radially outwardly. This increases at most the contact force of the teeth on the pipe but does not result in overloading of support means of any kind.
Preferably, the spike strip rests on the clamp body in the area of the other longitudinal edge, wherein the clamp body and the spike strip have matching contact shapes which receive pressure forces in the axial and radial directions. In this way, across the greater part of the circumference of the clamp body there is no permanent attachment required between the clamp body and the spike strip. It is sufficient when on the clamp body and/or on the spike strip shaped portions are provided which support one another such that the spike strip can be moved in an axial direction relative to the clamp body. A movement in the radial direction (relative to an annular clamp body, respectively), is not possible anyway because such a radial movement is prevented by the clamp body.
It is particularly preferred in this context that the clamp body has a radially inwardly bent edge portion which forms an inner angle in which the other longitudinal edge of the spike strip is arranged. Accordingly, the clamp body is bent at its axial ends so that the clamp body, in cross-section, has a U-shaped profile or a C-shape profile open radially inwardly. When the spike strip is now positioned into the corner of the profile, wherein the spike strip together with the clamp body delimits an angle in the range of 15° to 75°, the edge portion provides a sufficient support relative to a movement of the spike strip relative to the clamp body in the axially outward direction. The clamp body itself provides a sufficient abutment relative to a movement radially outwardly. When the tension in the clamp body increases because the clamp body is positioned somewhat tighter about the pipe, the spike strip cannot yield or move away but can only elastically yield in the direction toward the clamp body wherein possibly the angle between the spike strip and the clamp body changes; otherwise, no change in the geometry can be observed.
Preferably, the spike strip is connected with its ends to the clamp body. This embodiment is particularly advantageous when in the circumferential direction of the pipe clamp two or more spike strips are provided. When the spike strip is a ring, optionally also in the form of a ring which is interrupted once, it is sufficient in many cases to simply place the ring into the clamp body. When, on the other hand, several ring sections are provided, the attachment of the ends of the spike strip prevents that the spike strip can be lost. Moreover, the fixation of the spike strip on the clamp body achieves that the clamping forces can be generated with sufficient precision where they are supposed to act.
Preferably, the spike strip is positive-lockingly connected with the clamp body. A positive-locking connection can be produced in a simple way. It requires no complex additional measures such as welding, soldering or gluing. It is only required to shape certain areas of the clamp body and/or of the spike strip so that the corresponding connecting geometry can be produced. The positive-locking connection is limited to the ends of the spike strip.
In this connection it is particularly preferred that the clamp body and the spike strip are connected to one another by hoops which are formed as a unitary part of the clamp body and positive-lockingly connected with the spike strip, or formed as a unitary part of the spike strip and positive-lockingly connected with the clamp body, or positive-lockingly connected with the spike strip and the clamp body. Such a configuration can be produced relatively simply. It is sufficient to stamp certain parts and to bend them. This can be carried out during the stamping and bending processes which are required anyway for producing the pipe clamp.
Preferably, on each one of the spike strips a hoop is connected on at least two sides of the hoop with the clamp body and forms a pocket into which the spike strip can be inserted. Such a configuration of the hoop increases the stability and strength of the connection of the hoop with the correlated part of the clamp body or the spike strip. For attachment of the spike strip on the clamp body, a movement of the spike strip relative to the clamp body is required. However, this can be realized in most situations.
In this connection, it is advantageous when the hoop is fastened with one end while it can be bent open at the end. In this way, the bending process upon attachment of the spike strip on the clamp body is limited to the hoop so that neither the clamp body nor the spike strip must be deformed.
Preferably, one end of the hoop is fastened on the edge portion. In this way, the hoop can begin already at a certain radial spacing from the clamp body, i.e., in certain situations one or the other bending process can be omitted. In particular when the hoop is fastened with both ends on the clamp body, no extension of the hoop itself is required.
Preferably, the spike strip has at least at one end a fastening portion which is rotated relative to the remainder of the spike strip. As already mentioned, the spike strip and the clamp body together delimit an acute angle. This angle would also be provided at the fastening portion so that a corresponding great radial extension of the hoop would be required. When instead the fastening portion is rotated somewhat relative to the remainder of the spike strip, the radial length of the hoop can be reduced.
In this connection, it is particularly preferred that the fastening portion is arranged at least approximately parallel to the clamp body. The hoop can then have its minimal radial length. At the same time, when the fastening portion is forced approximately in a planar way against the clamp body, an improved holding of the spike strip on the clamp body is provided.
Preferably, the edge portion in the circumferential direction has at least one interruption. In this way, a hinge can be formed on the clamp body. This facilitates on the one hand the manufacture of the pipe clamp because with a folded-open clamp body a better access to the interior of the clamp body is possible. This is advantageous particularly when positioning the spike strips. On the other hand, mounting or demounting of the pipe clamp by a worker is facilitated because the worker is able to bend the clamp body open, for example, in order to place the clamp about the pipe or pipe ends or to remove it therefrom.
Preferably, the interruption is formed in that the edge portion is bent axially outwardly about a predetermined circumferential length. In this way, it is prevented during tightening that the force lines which form within the clamp body are interrupted. This improves the loading strength of the pipe clamp.
It is also advantageous when the interruption in the circumferential direction is arranged outside of a spike strip. In this way, the function of the hinge is not impaired by a spike strip. Mounting of the spike strip in the clamp body is simplified.
Also, it can be provided that the circumferential length of the clamp body is selected such that its circumferential ends rests against one another when the clamp is tightened to such an extent that the diameter of the circle described by the free tooth ends is smaller than the smallest nominal outer diameter, taking into consideration the pipe diameter tolerance range of the pipe or pipes to be received in the clamp.
In this way, overloading of the parts is prevented so that the clamp body can thus be tightened up to the point of contact of its ends (clamping jaws). Mounting can therefore be monitored visually without requiring measuring instruments of any kind. This means also that a torque wrench is not required. Still, the spike strip remains flexibly prestressed.
The invention will be explained in the following with the aid of a preferred embodiment in connection with the drawing.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a perspective illustration of a pipe clamp which is formed as a pipe coupling;
FIG. 2 is a side view, partially in vertical section;
FIG. 3 is a section III—III according to FIG. 2;
FIG. 4 is a section IV—IV according to FIG. 3;
FIG. 5 shows an enlarged view of a detail of FIG. 4;
FIG. 6 is a section VI—VI according to FIG. 3;
FIG. 7 shows an enlarged view of a detail of FIG. 6;
FIG. 8 shows an enlarged view of a detail of FIG. 2; and
FIG. 9 is a plan view onto an interruption of an edge portion.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a pipe clamp 1 formed as a pipe coupling which is used for connecting smooth, i.e., free of profilings, end portions of two pipes (not illustrated). The pipe clamp 1 has a tightenable clamp body 2 which is substantially bent to a ring shape. The two ends of the clamp body 2 are tightened with the aid of clamping screws 3 wherein the ends of the clamp body 2 are moved toward one another when the clamping screws 3 are tightened so that the inner diameter of the area which is surrounded by the clamp body 2 is reduced. The clamping screws 3 are guided through a joint sleeve 4 and connected to the joint sleeve 5 by screwing. The joint sleeves 4 , 5 are arranged in loops 6 which are formed by bending end portions of the clamp body 2 and connected by thermal fusing, for example, projection welding or spot welding, with the main part of the clamp body and provide the clamping jaws of the pipe clamp together with the sleeves 4 , 5 or pivot bolts.
The clamp body 2 has at its two axial ends edge portions 8 which are bent radially inwardly. This can be seen in particular in FIGS. 4 and 5. The clamp body 2 forms thus in section a U-shaped or C-shaped profile that opens radially inwardly. Into the angles which are formed between the clamp body 2 and an edge portion 8 , respectively, a spike strip 9 is inserted. The spike strip 9 has teeth 10 which, relative to the clamp body 2 , are oriented radially inwardly. The spike strip 9 is bent such that the teeth 10 also project axially inwardly.
On each axial end of the clamp body 2 two spike strips 9 are arranged, as can be seen in particular in FIG. 3 . The spike strips 9 are free of any support about their entire length, i.e., between the ends of each spike strip 9 over the entire length the situation as illustrated in FIG. 5 is present: no support means or elements are arranged within an angle area 11 with an angle a in the range of 15° to 75° between the clamp body 2 and the spike strip 9 . The backside 19 of the spike strip 9 is free of any support or abutment. The spike strip 9 can thus be bent with elastic deformation radially against the clamp body 2 . A resistance in this connection is produced mainly by the spike strip 9 itself which, for a corresponding force loading upon tightening of the pipe clamp, must be deformed so that the teeth 10 can move farther radially outwardly. For this reason, it is theoretically possible to produce the spike strip 9 on each axial end of the clamp body 2 as a unitary part and to position it simply in the angle area 11 between the main portion of the clamp body 2 and the edge portion 8 . For practical reasons, it is however advantageous to provide the spike strip 9 in a multi-part configuration and to connect its end positive-lockingly with the clamp body 2 . Such a positive-locking connection is illustrated in FIGS. 7 and 8.
The spike strip 9 has therefore a fastening section 12 which, relative to the remainder of the spike strip 9 , is rotated such that the fastening section 12 is approximately parallel to the clamp body 2 .
The clamp body 2 as a hoop 13 which is formed in that the clamp body 2 , in the circumferential direction before and behind the hoop 13 , has two cuts which extend in the axial direction. The area between the two cuts (not illustrated in detail) then forms the hoop 13 which is pushed radially inwardly in order to obtain the shape illustrated in FIG. 7 . It can be seen that the hoop 13 is attached on the clamp body 2 as well as on the edge portion 8 . The connection between the clamp body 2 or the edge portion 8 and the hoop 13 is of a monolithic configuration at both ends of the hoop 13 . Between the hoop 13 and the clamp body 2 there is thus a pocket provided into which the fastening portion 12 of the spike strip 9 can be inserted. The hoop 13 can also be connected on three sides with the clamp body 2 and optionally the edge portion 8 so that the pocket for insertion of the spike strip 9 is open only at one side.
The other end of the spike strip 9 is fastened in a similar way. A hoop 14 is bent out of the clamp body 2 and generated by a U-shaped cut in the clamp body 2 . The resulting tab can then be bent substantially perpendicularly relative to the clamp body radially inwardly and at the end radially outwardly in a U-shape so that the other end portion 15 of the spike strip 9 can be enclosed by the hoop 14 . This provides a positive-locking connection between the clamp body 2 and the spike strip 9 which requires no additional fastening parts or fastening methods. Of course, the fastening portion 15 can also be bent or connected relative to the remainder of the spike strip 9 . The different illustration in FIGS. 7 and 8 has been selected in order to demonstrate both possibilities.
As is shown in FIG. 1, the edge portion 8 has an interruption 16 on each circumferential end. This interruption 16 is illustrated on an enlarged scale in FIG. 9 . It can be seen that the edge portion 8 is bent outwardly and forms a surface 17 which is substantially positioned in the same plane as the clamp body 2 . This configuration has the advantage that the force flow in the circumferential direction is not interrupted to such a great extent as in the case of a simple radial cut in the edge portion 8 . The interruption 16 provides a kind of hinge where the clamp body 2 , after releasing the clamping screws 3 , can be bent open. This bending-open action facilitates the manufacture of the pipe clamp 1 , in particular, the insertion or introduction of the spike strips 9 . The fastening portions 12 in the area of the hinge sleeves 4 , 5 are inserted when the clamp body is in the open position. Subsequently, the hoops 14 at the other end are bent about the end portions 15 and the spike strips 9 are fixed reliably in the clamp body 2 .
Also, when the pipe clamp 1 is mounted on a pipe or removed from a pipe, it can be advantageous for the worker when the pipe clamp 1 can be bent open in order to place it about the pipe or to remove it from the pipe.
The function of the pipe clamp can be described as follows:
When the pipe clamp 1 has been placed about a pipe or about two pipe ends, the clamping screws 3 are tightened. In doing so, the inner diameter of the space surrounded by the clamp body 2 is reduced. The teeth 10 then first contact and later on engage the circumferential surface of the pipe or pipe section. When the tightening screws 3 are tightened farther, and the pipe clamp 1 is thus tightened even more, the teeth 10 can move or yield radially outwardly. This requires that they also perform a corresponding movement in the axially inward direction because the spike strips 9 in a way must be tilted about the corner point of the angle area 11 , so that, particularly in the case of loading of pipe ends, the pipes are forced to a greater extent toward one another. Since the spike strips 9 , aside from the contact of the longitudinal edge 18 which is not provided with teeth 10 , and the attachment of the end portions 12 , 15 are not supported in the radial direction, the teeth 10 can be moved freely outwardly. In this way, the pressing force onto the pipe is increased. However, other parts cannot be overloaded. In particular, it is not required to pay attention to applying a predetermined torque for tightening the pipe clamp 1 . The pipe clamp can be tightened, essentially with visual checking, and the tension can be controlled in that attention is paid to whether the two loops 6 of the clamping jaws with the joint sleeves 4 , 5 are positioned at a certain spacing from one another or, for a correspondingly longer clamp body, the pipe clamp is tightened so that the ends abut one another. Preferably, the circumferential length of the clamp body 2 is selected such that its circumferential ends are contacting one another when the pipe clamp is tightened to such an extent that the diameter of the circle described by the free tooth ends is smaller than the minimal nominal outer diameter of the pipe or pipes to be received in the clamp, taking into account the pipe diameter tolerance range in this connection.
If at the inner side of the spike strips 9 , i.e., between the slanted backside of the spike strips 9 , facing the inner side of the clamp body 2 , and the clamp body 2 , a support were present, for example, in the form of a rubber sleeve or a projection bent out of the clamp body 2 or the like, then the radially outward movement of the teeth would be impeded, which is to be prevented with the present invention.
The attachment of the spike strips 9 on the clamp body 2 can also be provided in a different way, for example, in that on the spike strip 9 corresponding hoops are formed which engage cutouts or openings or bores on the clamp strip 2 . It is also possible to provide hoops which are formed as separate parts and engage about the spike strip and corresponding shaped portions on the clamp body 2 .
Moreover, it is not an absolute requirement that the clamp body 2 is provided with the edge portions 8 when the securing action of the spike strips 9 on the clamp body 2 can be achieved in a different way. One possibility would be to provide or form on the spike strip 9 radially extending projections which engage corresponding cutouts in the clamp body 2 .
While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. | A pipe clamp has a tightenable clamp body and at least one spike strip arranged radially inwardly within the clamp body and slanted toward the axial center of the clamp body. The spike strip and a radially inner side of the clamp body delimit an acute angle therebetween. The spike strip has a first longitudinal edge provided with teeth projecting radially inwardly and slanted axially relative to the clamp body. The at least one spike strip has a second longitudinal edge supported in a radial direction and in an axial direction on the clamp body. An area between the at least one spike strip and the radially inner side of the clamp body defined by the acute angle is free of parts counteracting a bending of the at least one spike strip toward the radially inner side of the clamp body. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of copending application Ser. No. 728,949 filed Oct. 4, 1976, now abandoned, and assigned to the assignee of the present invention.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to kinetic energy absorbing devices, and more particularly to pads having a core which, under the force of an impact load, is adapted to undergo stepwise deformation, thereby to reduce significantly the peak dynamic load sustained by the pad.
2. Description of the Prior Art
Nuclear energy plants, nuclear fuel processing plants as well as other process plants incorporate pipes and conduits for conveying fluids under a broad range of pressures. Of particular concern are the extremely high pressure conduits. Should a fracture occur in such a conduit, particularly adjacent to a conduit elbow, the issuing high pressure fluids produce a jet force which whips the broken conduit at an extremely high velocity. An enormous impact load is applied by the whipping conduit to the first stationary object in its path. Absorption of the kinetic energy of such high velocity conduits is achieved by devices known as pipe whip restraint pads. The pad incorporates a core which is crushed by the impact load. Absorption of the kinetic energy is achieved by crushing, that is wrinkle buckling the core elements.
Energy absorbing honeycomb structures are known in the art, see for example, U.S. Pat. No. 3,130,819 (A. C. MARSHALL); U.S. Pat. No. 3,552,525 (C. R. SCHUDEL).
Conventional honeycomb exhibits a uniform energy absorbing characteristic when mechanical forces are applied to the columnar ends of the honeycomb cells. Generally, a honeycomb structure comprises plural corrugated ribbons of sheet material such as metal foil, paper, plastic or the like which are secured together at spaced node points. The resulting structure presents plural hollow, multisided, parallel cells. The application of mechanical forces to the columnar ends of the cells causes the cell walls to fold into small accordian-like pleats resulting in compression of the structure and absorption of energy.
Another characteristic of honeycomb is that its compression or columnar strength is considerably greater than its uniform crush strength. For this reason extremely high initial peak loads are required to initiate buckling of the cell walls. When conventional honeycomb is used as the core of a pipe whip restraint pad, the structural framework or the support to which the pad is secured also must be capable of sustaining the high peak loads.
To eliminate the high buckle-initiating peak loads, the honeycomb core has been partially crushed in a direction parallel with the cells and to a selected depth prior to being assembled into the device, see MARSHALL patent, supra. Since buckling of the core has been initiated, only a relatively low peak load is attained when the pad sustains an impact load. That is, a peak load sufficient only to continue crushing the core.
Although high buckle-initiating peak loads are not encountered by the MARSHALL core when in use, they are encountered during manufacture of the core, that is when precrushing the core. It will be appreciated that core precrushing requires the expenditure of large amounts of costly energy.
Honeycomb cores providing gradually increasing energy absorption also are known in the art, see for example the SCHUDEL patent, supra. Such honeycomb cores have a wedge-shaped end. The anvil--the member which compresses the core--encounters increasing resistance since it must collapse ever increasing cross-sectional areas of honeycomb. Wedge-shaped energy absorbers, when compressed, produce angularly presented splaying forces which cause delamination of the honeycomb at the bonded node points. The angular splaying forces are avoided in the SCHUDEL structure by providing a suitably shaped concavity in the anvil. Wedge-shaped energy absorbers may be formed from an expanded honeycomb structure presenting hexagonal cells or as corrugated spiral wound constructions.
SUMMARY OF THE INVENTION
The principal object of this invention is to provide an impact load sustaining pad requiring buckle-initiating peak loads significantly less than those required by prior art pads.
Another object of this invention is to provide an impact load sustaining pad wherein the heretofore encountered, relatively high, buckle-initiating peak loads are completely eliminated during manufacture of the pad and during use of the pad.
Still another object of this invention is to provide an impact load sustaining device incorporating deformable elements providing stepwise absorption of the kinetic energy of the impact load.
A further object of this invention is to provide an impact load sustaining pad adaptable to absorb the kinetic energy of a broad range of impact loads.
Still another object of this invention is to assemble a crushable core from a plurality of individual cellular units which act independently of each other during energy absorption, whereby the core has a predictable energy absorbing capacity.
Broadly, the present invention provides a pad adapted to sustain an impact load by stepwise absorption of the kinetic energy thereof. The pad includes first means adapted to absorb a quantity of kinetic energy, and at least second means adapted to absorb substantially the balance of the kinetic energy. The second means acts independently of the first means and is offset relative to the first means along the line of action of the impact load. Distributing means is provided for distributing the impact load initially to the first means and subsequently and simultaneously to the first means and to the second means, thereby to achieve a significant reduction in the peak dynamic load sustained by the pad.
More specifically, the present device comprises a face plate adapted to be positioned transversely of and in confronting relation with the line of action of the impact load. A base plate is spaced apart from and substantially parallel with the face plate. A crushable core is positioned between the face plate and the base plate and is adapted to collapse under the force of the impact load. The core includes profiled elements having corrugations extending perpendicular to the face plate and which are assembled in pairs to provide individual metal cellular units which buckle independently of each other under the force of the impact load. The profiled elements have substantially coplanar first end faces adjacent to one plate, substantially coplanar second end faces adjacent to the other plate, and third end faces which are spaced-apart from the other plate and which reside in a plane extending between and generally parallel with the planes of the first and second end faces. The second and third end faces are alternately presented. Moreover, the distance between the second and first end faces is greater than the distance between the third and first end faces. The arrangement is such that the face plate is adapted to distribute the force of the impact load initially to a first set of the profiled elements through the first and second end faces, and subsequently and simultaneously to a second set of the profiled elements through the first and third end faces and to the first set of profiled elements, thereby to reduce significantly the peak dynamic load sustained by the device.
The arrangement is such that the pad sustains two or more separate peak dynamic loads. The first peak load corresponds to that load required to initiate buckling in the first set of profiled elements. As the first set of profiled elements buckle, the sustained load decreases until the face plate engages the third end faces. At this time the pad experiences a second peak load which is a composite of that load required to initiate buckling in the second set of profiled elements, and that load required to continue buckling the first set of profiled elements. Thereafter the sustained load decreases to a minimum and increases again to a constant applied load wherein the first and second sets of profiled elements undergo plastic deformation.
Where all of the profiled elements are of the same thickness or gauge, the second peak load is greater than the first peak load--the second peak load being a composite of that load required to initiate buckling of the second set of profiled elements and that load required to continue buckling of the first set of profiled elements. To reduce the second peak load, the second set of profiled elements may be formed from lighter gauge material. For example, if the first set of profiled elements is formed from 12 gauge material, the second set of profiled elements may be formed from 14 or 16 gauge material. The reduction in the second peak load is attributed to a reduced buckle-initiating peak load for the lighter gauge second set of profiled elements.
Further in accordance with this invention, the core may comprise groups of profiled elements. The end faces of the elements of each group are stepped or tiered whereby a plurality of peak loads are encountered, one for each additional set of the profiled elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view schematically illustrating a pipe whip restraint pad positioned adjacent to a high pressure conduit;
FIG. 2 is a view similar to FIG. 1 illustrating the mode of absorbing the kinetic energy of the broken high pressure conduit;
FIG. 3 is a cross-sectional plan view of the present pad taken along the line 3--3 of FIG. 4;
FIG. 4 is a cross-sectional view taken along the line 4--4 of FIG. 3;
FIG. 5 is a cross-sectional view taken along the line 5--5 of FIG. 4;
FIG. 6 is a fragmentary isometric view of a profiled sheet metal element useful in the present pad;
FIG. 7 is a fragmentary isometric view of a metal cellular unit assembled from a pair of the profiled elements of FIG. 6;
FIG. 8 is an end view of the crushable core assembled from a plurality of the metal cellular units of FIG. 7;
FIG. 9 is an end view of the core of FIG. 8;
FIG. 10 is a fragmentary isometric view of a pair of metal cellular units formed from different gauge materials;
FIG. 11 is an end view of another metal cellular unit useful in the present crushable core;
FIG. 12 is a graphical presentation of the general relationship between applied load and the deformation of a crushable core;
FIG. 13 is a graphical presentation similar to FIG. 12 comparing the load versus deformation curve of the present unit and a prior art unit;
FIG. 14 is a graphical presentation similar to FIG. 12 illustrating the kinetic energy absorbing capability of the present pad as a function of sheet metal gauge;
FIG. 15 is a graphical presentation similar to FIG. 12 illustrating the kinetic energy absorbing capability of the present pad as a function of the number of metal cellular units in the crushable core;
FIGS. 16 and 17 are end and side views, respectively, of an alternative arrangement of the present crushable core;
FIG. 18 is a graphical presentation similar to FIG. 13 illustrating the load versus deformation curve of the crushable core of FIG. 16 compared with a prior art unit;
FIG. 19 is a fragmentary isometric view of a metal cellular unit useful in the crushable core of FIG. 16, wherein the profiled elements are of a different gauge thickness;
FIG. 20 is a graphical presentation similar to FIG. 18 illustrating the load versus deformation curve produced by employing the metal cellular units of FIG. 19;
FIG. 21 is an end view of a further alternative embodiment of the present crushable core;
FIGS. 22 and 23 are end and fragmentary isometric views, respectively, wherein the profiled elements present plural offset ends;
FIGS. 24 and 25 are end and side views, respectively, wherein the end faces of each group of profiled elements are stepped or tiered; and
FIGS. 26 to 28 are end views illustrating further alternative embodiments of the present crushable core.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 schematically illustrates a pipe whip restraint pad 35 of this invention secured to a suitable support such as a structural column 36. The pad 35 includes a face plate 37, a base plate 38 spaced apart therefrom and parallel therewith, and a crushable core 39 extending between the plates 37, 38. The pad 35 is positioned adjacent to an elbow 40 of a high pressure conduit 41. The high pressure conduit 41 conveys high pressure fluids in the direction of the arrow 42. Thus positioned, the pad 35 is adapted to restrain the whipping action of the conduit 41 and to absorb the kinetic energy thereof, should a crack, such as illustrated in dotted outline at 43, develop in the conduit segment 44 downstream of the elbow 40.
Should the conduit 41 fracture at the location 43, the issuing high pressure fluids provide a jet force represented by the arrow 45 in FIG. 2, which whips the conduit 41 at a high velocity and with enormous kinetic energy against the face plate 37. The line of action of the jet force 45 is indicated by the arrow 46 in FIG. 2. The kinetic energy of the high velocity broken conduit is absorbed by wrinkle buckling of the elements of the crushable core 39. As will hereinafter be explained in greater detail, the crushable core 39 sustains multiple peak loads each of which is significantly less than the peak load sustained by prior art devices. Thus the structural strength requirements of the structural column 36 or of other suitable pad supports is significantly less than that required when using prior art devices.
Referring to FIGS. 3 through 5, the pad 35 may include an interior perimeter wall 47 secured to the base plate 38, and an exterior perimeter wall 48 secured to the face plate 37. The perimeter wall 48 is positioned in telescoping relation with the interior perimeter wall 47. As best shown in FIG. 5, the interior perimeter wall 47 presents a perimeter face 49 which confronts the interior face of the face plate 37. The perimeter face 49 is spaced-apart from the face plate 37 by a distance indicated at 50. During energy absorption, such as illustrated in FIG. 2, the face plate 37 is displaced through the distance 50. The distance 50 may vary from about 1 inch to about 16 inches.
The present crushable core is formed from a plurality of elements, such as the profiled sheet metal element 51 illustrated in FIG. 6. The sheet metal element 51 presents alternating crests 52 and valleys 53 connected by inclined webs 54. The profiled sheet metal elements 51 preferably are assembled in valley-to-valley relation and secured together by plural tack welds 56 to provide a metal cellular unit 55 such as illustrated in FIG. 7.
Referring to FIGS. 8 and 9, the crushable core 39 provides first means, e.g. plural first metal cellular units 55A, for absorbing a portion of the kinetic energy; and second means, e.g. plural second metal cellular units 55B, for absorbing substantially the balance of the kinetic energy. The metal cellular units 55 are assembled with the crests 52 (FIG. 8) thereof in engagement. To facilitate handling the crushable core 39, plural fasteners 56 may be provided to secure the plural metal cellular units 55 together as a unitary assembly. If desired, spot welds 57 may also be provided as additional securement for the metal cellular units 55. It should be understood that the individual metal cellular units 55 buckle independently of each other under the force of an impact load. Therefore the fasteners 56 and the tack welds 57 may be omitted.
As best shown in FIG. 8, each of the metal cellular units 55 presents plural parallel cells 58. In addition, the adjacent ones of the metal cellular units 55 provide additional longitudinal cells 59. The cells 58, 59 have longitudinal center lines 60, 61, respectively.
In accordance with the present invention, the first metal cellular units 55A have a first axial length L a1 , whereas the second metal cellular units 55B have a second axial length L a2 which is less than the first axial length L a1 . The first and second metal cellular units 55A, 55B preferably are alternately presented. As best shown in FIG. 9, the sheet metal units 51A and 51B present coplanar first end faces 62 residing substantially in a first common plane P 1 . The sheet metal elements 51A present second end faces 63 residing substantially in a second common plane P 2 . The sheet metal elements 51B present third end faces 64 residing substantially in a third common plane P 3 which extends between and which is generally parallel with the first and second common planes P 1 , P 2 . The third end faces 64 are inwardly offset from the second end faces 63 by an incremental distance indicated at 65. It will be observed in FIG. 5 that the core 39 is positioned such that the longitudinal centerlines 60, 61 of the cells 58, 61 (FIG. 8) are normal to the face plate 37. The crushable core 39 (FIG. 4) presents the first end faces 62 adjacent to the base plate 38, the second end faces 63 adjacent to the face plate 37, and the third end faces 64 inwardly spaced-apart from the face plate 37. The significance of the incremental distance 65 will become apparent later in the specification. As will also become apparent later in the specification, the pad 35 includes distributing means, e.g. the face plate 37, for distributing the force of the impact load initially to the first means (the first metal cellular units 55A); and subsequently and simultaneously to the first means and to the second means (the second metal cellular units 55B).
All of the elements 51 of the metal cellular units 55A and 55B may be formed from the same gauge sheet metal. Sheet metal gauges in the range of 12 to 16 gauge have been found suitable for the present purposes. Alternatively, the sheet metal elements 51A and 51C (FIG. 10) of the first and second metal cellular units 55A, 55C may be formed from sheet metal of different thicknesses. Preferably the second metal cellular unit 55C--the shorter metal cellular unit--is formed from a lighter gauge sheet metal. The metal cellular units 55A, 55C preferably are alternately presented when assembled to provide a crushable core 39A.
FIG. 11 illustrates a crushable core 39B comprising plural metal cellular units 55D each assembled from profiled sheet metal elements 51D whose profile differs from the sheet metal elements 51 of FIG. 6. The sheet metal elements may take any suitable profile.
A general relationship between the applied load and the core deformation is graphically presented in FIG. 12. The solid line 66 represents the ideal load versus core deformation curve. The dotted line 67 represents a typical load versus core deformation curve of prior art pads.
It will be observed that in the ideal curve 66, the applied load increases rapidly to the plastic deformation stage 68 during which the core deforms essentially uniformly at a constant load 69. The typical curve 67 departs drastically from the ideal curve 66, in that it reaches a peak load 70 which is considerably higher than the constant load 69. The peak load 70 corresponds to that load required to initiate wrinkle buckling of the crushable core. Following the peak load 70, the typical curve 67 falls to a load level 71 below the constant load 69 and then rises essentially to the constant load 69. It will be appreciated that the relatively high peak load 70 sustained by the restraint pad also must be sustained by the pad support.
The crushable core 39 of the present invention completely avoids the relatively high peak loads sustained by prior art devices during their use or during their manufacture. In FIG. 13, the solid line 72 represents an idealized applied load versus core deformation curve for the crushable core 39 illustrated in FIGS. 8 and 9. The crushable core 39 contains five metal cellular units 55, three units 55A of unit length and two units 55B of a length less than unit length. It will be observed in FIG. 13 that the crushable core 39 sustains a first peak load 73 which is considerably less than the peak load 70 of conventional restraint pads. The peak load 73 corresponds to the buckle-initiating load of the three first metal cellular units 55A. Thereafter, the sustained load reduces to a lower load level 74. At this point, the face plate 37 (FIG. 4) contacts the third end faces 64 of the second metal cellular units 55B. The sustained load increases to a second peak load 75 which is a composite of that load required to initiate buckling in the second metal cellular units 55B and that load required to continue buckling of the first metal cellular units 55A.
Following the peak load 75, the sustained load reduces to a second lower load level 76 and then rises to a plastic deformation stage or load 77. The present restraint pad 35 undergoes a greater amount of deformation to reach the plastic deformation stage 77 than does the typical prior art pad--compare deformation lengths L 1 and L 2 . Notwithstanding the greater deformation length L 2 , the present pad drastically reduces the peak load sustained by the pad and, hence, the peak load sustained by the pad support.
Where the profiled elements 51 are formed from sheet steel, the incremental distance 65 (FIG. 9) may vary from a minimum of 0.25 inches (0.64 cm) to about 0.75 inches (1.91 cm). When the incremental distance 65 is less than 0.25 inches, the core exhibits a single large peak load. When the incremental distance exceeds 0.75 inches, the core deformation length L (FIG. 13) required to attain the plastic deformation stage is unduly increased with a consequent loss in the energy absorbing capacity of the pad.
The larger second peak load 75 may be reduced to a level substantially equal to that of the first peak load 73--see peak load 75A (FIG. 13)--by utilizing the arrangement illustrated in FIG. 10 wherein the profiled elements 51C of the second metal cellular units 55C are formed from lighter gauge sheet metal.
The energy absorbing capacity of the present restraint pad 35 varies with the sheet metal gauge. Specifically, the lighter the gauge the less the energy absorbing capacity. In FIG. 14, the curve 72 corresponds to the crushable core 39 wherein the profiled sheet metal elements thereof are formed from 12 gauge metal. The curves 78, 79, of reducing energy absorbing capacity, correspond to crushable cores utilizing profiled sheet metal elements formed from 14 gauge and 16 gauge metal respectively.
The energy absorbing capacity of the present restraint pad 35 also varies with the number of metal cellular units employed. Specifically, the greater the number of units, the greater the energy absorbing capacity. It will be observed in FIG. 15 that the curve 72 corresponds to five unit core 39 of FIGS. 3 to 5. The curve 80 corresponds to a three unit core and has a reduced kinetic energy absorbing capacity. The curves 81, 82 and 83 correspond to 7, 10 and 15 unit cores having increasing kinetic energy absorbing capacity.
Alternative embodiments of the present crushable core are illustrated in FIGS. 16 through 28. Corresponding numerals will be employed to identify corresponding parts heretofore described.
FIGS. 16 and 17 illustrate a crushable core 39C comprising a plurality of metal cellular units 55E. Each of the metal cellular units 55E comprises one of the profiled sheet metal elements 51A having a first axial length L a1 and one of the profiled sheet metal elements 51B having the lesser second axial length L a2 . The crushable core 39C presents a first set of profiled elements, that is the elements 51A; and a second set of profiled elements, that is the elements 51B. The second set of profiled elements presents substantially coplanar third end faces 64 which are inwardly offset from the substantially coplanar second end faces 63 of the first set of elements 51A by an incremental distance indicated at 65 (FIG. 16).
FIG. 18 diagrammatically illustrates the applied load versus core deformation curve identified by the number 84 of the crushable core 39C. It will be observed that the crushable core 39C sustains a first peak load 85 and a larger second peak load 86. Both of the peak loads 85, 86 are significantly less than the corresponding peak load 70 of a typical prior art pad.
FIG. 19 illustrates a metal cellular unit 55F assembled from one profiled sheet metal element 51A and one lighter gauge profiled sheet metal element 51E. The sheet metal elements 51E corresponds, in length, to the shorter sheet metal elements 51B of FIG. 16. A plurality of the metal cellular units 55F may be assembled to provide a crushable core 39D which generates the applied load versus core deformation curve 84A graphically illustrated in FIG. 20. Since the lighter gauge sheet metal elements 51E require a lower buckle-initiating peak load, it will be observed in FIG. 20 that the core 39D sustains a second peak load 87 which may be substantially the same as the first peak load 85 but which is significantly less than the peak load 86 sustained by the crushable core 39C of FIG. 16. Thus the second peak load may be reduced by utilizing thinner gauge elements as the second set of profiled sheet metal elements.
Another method of reducing the second peak load is to utilize sheet metal elements of different column strengths. FIG. 21 illustrates a metal cellular unit 55G assembled from sheet metal elements 51B and 51D. A plurality of the metal cellular units 55G may be assembled to provide a crushable core 39E, wherein the first set of profiled sheet metal elements corresponds to the elements 51D, and wherein the second set of profiled sheet metal elements corresponds to the elements 51B. It should be evident that the greater depth of the elements 51D attributes greater column strength to these units. The shallower depth of the elements 51B attributes a lesser column strength to these units. A further reduction in the second peak load may be achieved by forming the elements 51B from a lighter gauge sheet metal.
FIGS. 22 and 23 illustrate a further alternative crushable core 39F assembled from a plurality of metal cellular units 55H. As best shown in FIG. 23, the webs 53 of each of the metal cellular units 55H are cut on a bias as at 88, whereby each metal cellular unit 55H presents the substantially coplanar second end faces 63 and the inwardly offset substantially coplanar third faces 64.
FIGS. 24 and 25 illustrate a further alternative crushable core 39G assembled from plural groups 89 of profiled sheet metal elements 51A, 51B, 90, 91 and 92 of decreasing lengths. The profiled elements 51A, 51B, 90, 91, 92 of each group 89, present first end faces 62 adjacent to the base plate 38; a second end face 63 adjacent to the face plate 37; and third end faces 64, 93, 94 and 95 spaced-apart from the face plate 37 by successively larger distances 96 through 99, respectively. The third end faces 63, 93, 94, 95 of the two illustrated groups 89 reside substantially in spaced-apart common planes P 3 ', P 3 ", and P 3 '" which extend between and are generally parallel with the first and second planes P 1 , P 2 . The arrangement is such that the face plate 37 is adapted to distribute the force of an impact load initially to the profiled element 51A through the first and second end faces 62, 63 thereof, and subsequently and successively to the other profiled elements 51B, 90, 91 and 92 through the first and third end faces 62, 64, 93, 94 and 95 thereof, whereby the pad sustains plural peak loads.
The metal cellular units and the profiled elements of the crushable cores 39, 39C and 39G of FIGS. 9, 16 and 24 may be otherwise arranged and still provide a significant reduction in the peak loads sustained by the core. For example, FIG. 26 illustrates a core 39' comprising four metal cellular units, wherein the longer units 55A are provided on opposite sides of the shorter units 55B. FIG. 27 illustrates a core 39C' comprising four of the metal cellular units 55E arranged such that the longer profiled elements 51A are presented at the opposite sides of and at the center of the core 39C'. FIG. 28 illustrates a core 39G' comprising two sets 100 of the profiled elements 51A, 51B, 90, 91, and 92 of decreasing length. The arrangement is such that the longer profiled elements 51A are presented at the opposite sides of the core 39G' and such that the shortest profiled elements 92 are presented at the center of the core 39G'.
TEST RESULTS
Core samples were prepared, each comprising plural metal cellular units such as illustrated in FIG. 7. Each metal cellular unit was assembled from a pair of profiled sheet metal elements such as illustrated in FIG. 6. The metal cellular units were assembled in the manner illustrated in FIG. 8. The metal cellular units had an overall width of approximately 24 inches (61 cm). The width of the crest 52 was 3.625 inches (9.21 cm); and the distance between adjacent crests 52 was 2.375 inches (6.03 cm). The width of the valley 53 was 2.215 inches (5.40 cm). The distance between the inner surfaces of the crests 52 of each cell 58 was 3 inches (7.62 cm). The profiled elements were fabricated from 12 gauge sheet metal. The crushable cores were subjected to static load tests in a testing machine capable of applying a maximum load of 1,200 kips. The test results are summarized below. The "Core Size" identifies the number of metal cellular units in each core sample. Each of core samples 1, 3 and 4 contained metal cellular units of identical length. Core sample 2 was similar to that illustrated in FIGS. 8 and 9. Core samples 5 and 6 were similar to that illustrated in FIG. 16. In the columns headed "Load, Kips", F p1 is the first peak load, F p2 is the second peak load, and F f is the average crush load per inch of core deformation at the plastic deformation stage.
__________________________________________________________________________STATIC LOAD TESTS CORE HEIGHT OFFSET LOAD, KIPSSAMPLE SIZE GAUGE INCHES INCHES F.sub.p1 F.sub.p2 F.sub.f__________________________________________________________________________1 5 12 16.25 None (1) -- --2 5 12 16.25 0.5 910 958 7303 4 12 16.25 None 1,079 -- --4 4 12 16.25 None (2) -- --5 4 12 3.75 0.375 700 920 --6 4 12 3.75 0.375 660 933 --__________________________________________________________________________ (1)No evidence of failure at applied load of 1,195 kipstest terminated. (2)No evidence of failure at applied load of 1,120 kipstest terminated.
The peak load required to initiate crushing of core sample 1 exceeded the capacity of the testing machine and therefore has a value in excess of 1,200 kips. It will be observed that core sample 2 exhibited first and second peak loads which were 24% and 20%, respectively, less than the 1200 kips capacity of the testing machine and hence some higher percentage less than the peak failure load of core sample 1.
Core samples 3 and 4 were identical. Core sample 3 failed in an applied load of 1,079 kips while core sample 4 did not exhibit evidence of failure at an applied load of 1,120 kips. Core sample 5 exhibited first and second peak loads which were 35% and 14.7%, respectively, less than the peak load of core sample 3. Core sample 6 exhibited first and second peak loads which were 38.8% and 13.5% less than the peak load of core sample 3. | A pad adapted to sustain an impact load by stepwise absorption of kinetic energy. The pad incorporates a collapsible, i.e., crushable core adapted to undergo stepwise deformation under the force of the impact load. Stepwise deformation of the core provides, during impact load application, a significant lowering of the peak dynamic load sustained by the pad and applied to the pad support. The normally encountered high buckle-initiating peak loads are entirely avoided by the present pad. | 5 |
RELATED APPLICATIONS
[0001] This application claims priority benefit of U.S. Ser. No. 60/588677, filed Jul. 16, 2004.
BACKGROUND OF THE INVENTION
[0002] a) Field of the Invention
[0003] It is very common in rural locations to not have access to municipal utility services including potable water. Many times the water loads required by farms or dairies are such that the municipal services can be overburdened and consequently the dairy or farm may be required to obtain its own water. Generally the farms turn to on-site groundwater or surface water. On-site groundwater is usually un-potable and depending on the geographic location may have soluble iron or manganese due to the lack of dissolved oxygen content.
[0004] As is generally known in the art, iron and manganese are common elements widely distributed in nature. In the absence of oxygen, both of these elements are soluble in water. Both elements may form compounds with other soluble elements and can pollute water making it undesirable for human use. An aeration process will help to remove the compounds. The soluble forms of iron and manganese are in the plus two valence oxidation state. Upon contact with oxygen, or any other oxidizing agents, both the ferrous iron and manganese are oxidized to higher valences, forming new ionic complexes which are not soluble to any appreciable extent. Therefore, with the addition of oxygen to the compound, the iron and manganese may be removed as a precipitate after aeration.
[0005] In addition to aeration of the water converting the ferrous iron into a precipitate, chemical oxidants such as potassium permanganate can also be used. These chemical oxidants may sometimes be used in connection with an aeration process to increase processing speed.
[0006] Iron particularly poses problems including taste, staining, and accumulation within the pipes themselves. Iron will generally cause a reddish-brown staining of laundry, porcelain, dishes, utensils, teeth and even glassware. Further, the iron will over time settle out and buildup deposits in pipelines, pressure tanks, water heaters, and water softeners. Thus there are associated increases in energy costs and maintenance costs for removal of the iron deposits. In dairies the iron content will directly contaminate the cows and limit milk output.
[0007] To remove the soluble iron from the water an oxidation and filtration process is used. Filtering systems of this sort are generally comprised of two separate categories, the actual filtration process through which the water is cleaned and the backwashing operation through which the filter is cleaned. These operations are equally important in the overall filtration process. The most common practice for filtration is to use gravity filtration in a downward mode, but several other modes of operation are possible including up-flow, by-flow, and pressure or vacuum filtration.
[0008] During the filtration process, the water is injected with oxygen and the soluble iron content oxidizes. The oxidized water is then filtered through a filter media, generally either by using a greensand glauconite (for gravity flow modes) or, a buoyant manufactured filter media (used in up-flow modes).
[0009] In either case, the filter media will accumulate large amounts of insoluble iron content and the buildup must be removed by backwashing.
[0010] The backwashing process must be performed on a regular basis, such as every other day or biweekly depending upon the size of the operation.
[0011] With proper backwashing, the filtration process will successfully remove approximately 90% to 95% of the soluble iron content out of the source water. The filtered water is then treated to remove the remaining 5% to 10% of the soluble iron content.
[0012] To initiate backwashing, many of the filtration systems utilize a siphoning process to initiate the backwashing. The siphoning system is generally an automated process. The siphoning process requires constant servicing and adjustments.
[0013] When the pipes themselves are fully operable and not clogged with iron deposits, the automatic hydraulic siphoning system works well. But, after continuous use the pipe components tend to accumulate the iron content and consequently, reduced flow capacity and additional weight on the pipes themselves throws the siphoning system off-balance. Thus, continuous maintenance and servicing is generally required. This constant servicing can pose a hardship on the rural farms and dairies which are operating under tight financial constraints as well as posing logistical maintenance and servicing problems.
[0014] In summary, an oxidation/filtration/backwash system to remove soluble iron or manganese content from source groundwater utilizing an improved backwashing system as well as an assembly of interchangeable and self serviceable components is strongly needed.
[0015] b) Background Art
[0016] Generally the most common practice for filtration is the gravity filtration in a downward mode, but several other modes of operation are possible including up-flow, by-flow, and pressure or vacuum filtration. Listed below are various filtration devices with emphasis on backflushing.
[0017] U.S. Pat. No. 6,187,178 (Lecornu et al.) shows a filter with several back flow means including a siphon. There is an air bleed included which insures the siphon being broken at the proper point.
[0018] U.S. Pat. No. 6,063,269 (Miller et al.) shows a filter in a hydraulic system in which a portion of the fluid in the return line, is drawn by Venturi, to the filter line.
[0019] U.S. Pat. No. 5,705,054 (Hyrsky) provides a filtered water in-take in which water flows out through pipe. If intake is blocked, flow through siphon tubs brings water in through intake. There is a tube which can be used for siphon control.
[0020] U.S. Pat. No. 4,537,687 (Piper) discusses a filter which is cleaned by backflushing. This device shows a reverse siphon started by the application of a section port to initiate a backflow siphon flow in tube.
[0021] U.S. Pat. No. 4,317,733 (Xhomnneux) shows a filter with a body and a backflow washing means including a siphon tube. The siphon tube causes the flow of fluid to go backwards. The siphon starts when filter is clogged and the fluid in the chamber reaches a particular level.
[0022] U.S. Pat. No. 4,229,292 (Mori et al) discloses a regenerating column which is provided with a flushing siphon that starts when the flushing fluid reaches the desired level. The regeneration operation is started by an operator rather than being an automatic means.
[0023] U.S. Pat. No. 3,841,485 (Malkin) shows in a siphon system which has back pressure increases a siphon is developed through a pipe which draws fluid through pipes to draw water through the filter element. There is a siphon breaker tube provided to stop the back flow.
[0024] U.S. Pat. No. 3,825,120 (Takahashi) shows a system which includes pump means for moving the fluid being handled. In addition to the pumps there is a siphon pipe means which passes fluid to container.
[0025] U.S. Pat. No. 3,549,012 (Mackrle) shows a system in which under cleaning conditions a siphon starts when fluid in it reaches the proper level and air control valves are closed. The suction developed by the siphon is applied to a second siphon to clear an upper section.
[0026] U.S. Pat. No. 3,502,212 (Ueda) provides a siphon tube which is filled by liquid as the filter clogs. There are also air flow and feeding means that controls the start and end of the cleaning cycle. When the cleaning cycle is started a siphon liquid flowing draws both liquid and filtered material to a drain.
[0027] U.S. Pat. No. 3,342,334 (Soriente et al.) show a filter system in which during the cleaning operation a valve is opened and flushing fluid flows down a pipe. U.S. Pat. No. 3,111,486 (Soriente) shows a back flow system in which liquid is delivered by a tube. When the filter is blocked fluid accumulates so that it reaches a point high enough to flow into a siphon and passes out of the filter system drawing the blocking material with it.
[0028] U.S. Pat. No. 2,879, 891 (Beohner et al.) shows a filter which is provided with a siphon tube that fills when the back pressure caused by filter blockage, and the position of the air control means allow it to fill. When the siphon tube fills it draws fluid backwards through tubes and backwards through the filter materials and removes it.
[0029] U.S. Pat. No. 1,119,008 (Gibson) shows a water filtering system in which there is a pipe loop “L”, that appear to serve as a back flow cleaning siphon when valves are set for back washing. The control is in part a function of automatic float or flow control valves.
[0030] U.S. Pat. No. 630,988 (Reisert) shows a back flow system in which as the pressure increases liquid flows up pipe “I”, and down inner pipe “s”, so that a siphon is established.
[0031] Ukranian UA 411 (Dmitriyevich) discloses an oxidation/filtration apparatus where as the filtering medium muds the filter loss increases. The water level providing positive flow reaches a maximum height and primes a siphon to initiate rinsing of the filter medium.
SUMMARY OF THE INVENTION
[0032] An object of the current embodiment is to provide an oxidation filtration system which removes dissolved solvents such as iron or manganese from groundwater sources located in rural districts. The current system uses an oxidation and filtration system. The oxidation process uses and aeration tower allowing the dissolved iron to be oxygenated which then allows a portion of the iron to fallout after reaching a solid-state.
[0033] The filtration process uses a plurality of boyant filter media which in the current embodiment is constructed of small buoyant Styrofoam™ beads. The Styrofoam's valence attracts the oxygenated solvents and further filters out the solvents. The groundwater which passes through this filter media is then mostly clear of the dissolved solvents, thus being ready for additional filtering processes.
[0034] An additional object of the current environment is to increase the water quality of the filtered water by reducing the number of transfer lines and junctions which accumulate within the oxidized material. By reducing the transfer lines, less maintenance is required on a regular basis and when maintenance is required, the filtering is more efficient and predictable.
[0035] An additional object of the current embodiment is too provide an improved flushing system to clean the boyant filter media, thus reducing the on-site maintenance of the filtering unit.
[0036] An automated system using sensors and discharge ports operated by valves and solenoids and being controlled by a programmable logic controller orchestrates the filtering of the water, the back flushing of the filter media, and the clarification of the back flushed water. Also, the programmable logic controller orchestrates the operation of multiple filtering tanks or units at a large production facility. The PLC is operable by a remote client computer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is an elevation view of a prior embodiment;
[0038] FIG. 2 is an elevation view of the oxidation, filtration, back flush, system;
[0039] FIG. 2 a is an alternative embodiment elevational view of the oxidation, filtration, back flush, system;
[0040] FIG. 3 is an elevation view of the backflushing system;
[0041] FIG. 3 a is an alternative embodiment elevational view of the backflushing system;
[0042] FIG. 4 is an elevation view of the cleansing system;
[0043] FIG. 4 a is an alternative embodiment elevational view of the cleansing system;
[0044] FIG. 5 is a diagram of the programmable logic controller and system elements;
[0045] FIG. 6 is a diagram of the control application and control objects;
[0046] FIG. 7 is a plan view of the oxidation filtration tank assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] A detailed description of a prior art embodiment will now be discussed followed by a detailed discussion of an embodiment of the present invention.
[0048] In discussing the present embodiment a description of the existing systems will first be provided.
[0049] As stated above, it is general practice to remove soluble iron from water by utilizing an oxidation/filtration process 11 as shown in FIG. 1 . Filtering systems of this sort are generally comprised of two separate categories, the actual filtration process and the back-washing operation to clean the filter.
[0050] Still referring to FIG. 1 , a common oxidation/filtration system 11 is shown with a filter chamber 46 and a water tower 24 . The groundwater 12 is pumped from a groundwater well and fed into a pressurized source line 14 . To provide the oxygen, a Venturi-type aerator injector 15 forces compressed air into the groundwater 12 , thus creating the first stage of the aeration process. Next, the pressurized water passes through a spray nozzle 16 which disperses the groundwater 12 into a closed water tower 24 completing the aeration process. The water tower 24 is typically cylindrical and stands approximately 20 ft. in height. The aerated water descends to the bottom of the water tower 24 , and then it enters into an opening 84 of a cylindrical feed line 80 which is concentric within the water tower 24 . The water entering into the opening 84 will flow through a distribution line 82 which directs the water into a manifold 83 , the water passes upwardly through the filter chamber 46 in which is positioned a low density filter media 50 . At the same time the water is flowing upward through the filter media 50 thus filling the filter chamber 46 , the water is also rising in the cylindrical feed line 80 .
[0051] As the water continues to flow into the filter tank 46 , it enters into the upper portion 45 of the filter take 46 and begins to flow out of the clean water outlet 54 . There is a screen 52 at about the mid height of the tank 46 which stops the filter media 50 from migrating from the filter tank lower portion 47 into the filter tank upper portion 45 .
[0052] When efficient filtration occurs the water head in the water tower 24 will stay at approximately constant height, which also results in a constant output of clean water running through the clean water outlet 54 of the filter chamber 46 . Thus, as the filtration process 11 continues, particulate filtrate matter 51 will begin to accumulate as it attaches in, around and to the low density filter media 50 .
[0053] Eventually the filter media 50 will become so congested with the particulate 51 that the backwash operation will engage.
[0054] This engagement occurs because as more and more particulate 51 attaches to the filter media 50 , the filtration flow decreases and water pressure head in the water tower 24 begins to increase. With the building water pressure in the water tower 24 the height of the water in the cylindrical feed line 80 rises.
[0055] The water in the cylindrical feed line 80 will reach the level of the connecting line 86 at the top of the feed line 80 which in turn leads to the discharge line 88 . The discharge line 88 extends downwardly into a waste lock basin 90 in a holding tank 92 . The flow of the water downward in the discharge line 88 creates the siphon vacuum. This vacuum starts drawing water out of the filter tank 46 . As the water drops down in the filter tank 46 , exiting the holding tank 92 , the level of the water in the filter tank 46 will reach the lower end 96 of the vacuum line 98 , or in other words, the upper part 45 of the filter tank 46 . With this drop in water level, the vacuum line 98 becomes open to atmospheric pressure, and thus interrupts the siphoning action which is occurring in the discharge line 88 . The water remaining in the discharge line 88 drops into the waste lock basin 90 and the water remaining in the cylindrical feed line 80 drops back to the distribution line 82 to restart the filtration process.
[0056] As previously stated before, the oxidation filtration system 11 will need to perform the siphoning and back flush process on a regular basis. Over time the ferrous soluble iron content in the groundwater will adhere to the inner regions of the cylindrical feed line 80 , the distribution line 82 , and tend to clog the feed line opening 84 , as well as the discharge openings in the manifold 83 . Where the soluble iron content is high, the clogging of these various filtration system components will occur more frequently.
[0057] This accumulation requires constant maintenance of the oxidation filtration system 11 and over the long term is more expensive to maintain than the preferred embodiment as discussed below.
[0058] Even if operation continues unimpeded, the inner diameter of the cylindrical feed line 80 will tend to decrease in size due to the increase in filtrate particulate 51 accumulation. With a smaller diameter comes a slower flow rate through the distribution line 82 and the cylindrical feed line 80 during the discharge process. Additionally, the many bends and turns in the pipes which comprise the discharge system and siphoning process add a level of complexity to the overall design which is not needed.
[0059] Additionally the backwash system itself likely will not carry the heavier filtrate particles 51 which are residing in the bottom of the filter chamber 46 up and over the connecting line 86 . This tends to leave filtrate particulate 51 accumulations in the elbow between the cylindrical feed line 80 and the distribution line 82 . Lastly, immediately after the back flushing process has occurred the groundwater 12 which begins to accumulates and flow upwards starting at the filter tank lower portion 47 and flowing upwards through the low density filter media 50 finally passing through the screen 52 , will be cloudy due to the violence turbulence associated with the back flushing process. This cloud will tend to dissipate over time but in many cases the finer particles will be discharged out of the cleaning water outlet 54 and fed into the potable water lines feeding the residences or dairy buildings. To allow the fine filtrate particulate 51 to settle out, a cleansing or clarification period should be provided.
[0060] Within this context, an embodiment of the present concept will now be discussed.
[0061] A detailed discussion of a single oxidation filtration system will first be discussed followed by detailed discussion of an assembly of oxidation filtration systems as provided in current embodiment. First referring to FIGS. 2 and 2 a , the oxidation filtration system 10 is composed of three main elements: an aeration tower or water tower 24 , a filtration tank 46 , and an oxidation filtration monitoring and cleaning system or flushing system 35 . Each of the main components has a series of subcomponents which will be briefly discussed. The aeration tower 24 in the present embodiment is constructed of a 1 foot diameter polyvinyl chloride cylindrical pipe which stands approximately 20 feet in height. The aeration tower 24 has an upper zone 23 and a lower zone 25 . The upper zone is configured such that it can accept the outlet 17 of a pressurized groundwater source line 21 . Additionally, the lower zone 25 has a close-bottomed portion to keep the groundwater 12 contained. Feeding into the aeration tower upper zone 23 as previously discussed, is the groundwater source line 21 which holds pressurized groundwater 12 accumulated from the on-site water sources.
[0062] The groundwater must be pressured prior to being sprayed into the aeration tower upper zone 23 . Pressure is provided from a pressure source, and a pressure meter 20 is attached to the source line 14 so that monitoring of the groundwater pressure can occur. A source line valve handle 19 enables the operator to turn the filtration system 10 on and off as desired. The pressurized water runs through a Venturi-type aerator injector 15 which is attached to the source line 14 near the source line outlet 17 . Connected to the end of the source line, is a spray nozzle 16 . After running through the Venturi-type aerator 15 , the groundwater exits through the spray nozzle 16 which further acts to aerate the groundwater 12 thus converting the soluble ferrous iron content into a nonsoluble form, completing the oxidation portion of the process and allowing the particulate ferrous content 51 as described further herein to drop out of the groundwater 12 .
[0063] Once the groundwater has been aerated, the ferrous content is ready to drop out of the groundwater upon contact with a medium which has an attracting valence charge. Referring to FIG. 2 , connected to the aeration tower lower zone 25 is a source water crossover pipe 26 . This crossover pipe feeds the groundwater 12 from the aeration tower into the filtration tank 46 . Referring to FIG. 2 a , in an alternative embodiment, the aeration tower 24 is positioned within the filtration tank 46 . This combination eliminates the need for the crossover pipe 26 as seen in FIG. 2 . In this alternative embodiment, the aerated water 9 exits directly out of the aeration tower lower zone 25 and into the filter tank lower zone 47 through an exit port 102 .
[0064] Referring back to FIG. 2 , the filter tank 46 is constructed of a 3 foot diameter cylindrical polyvinyl chloride housing or pipe and has a filter tank lower zone or lower chamber 47 and a filter tank upper zone or upper chamber 45 . In the current embodiment, the filter tank 46 stands approximately 6 feet in height. Approximately mid-height of filter tank 46 is a secured media mesh filter 52 , which is essentially a size 10 filter mesh. Contained within the lower chamber 47 is a plurality of low density buoyant filter media 50 . In the current embodiment, this filter media is composed of a plurality of very small Styrofoam™ spheres. Each sphere measures approximately 1/100 of an inch in diameter. To provide for effective filtration, in the current embodiment, the volume of the filter media 50 is approximately 30 inches deep and 3 feet in diameter, which corresponds to the inner diameter of the filter tank 46 . To contain the water, the filter tank lower chamber 47 has a closed bottom portion which is watertight.
[0065] A brief discussion of the pipes or ports associated with the flushing system will now be provided. Part of the overall monitoring and cleaning or flushing system 35 is the opening and closing of various ports or exit and entrance pipes to create the desired turbulence in the filtration tank lower chamber 47 as well as to clarify the dislodged ferrous particulate after the turbulent back flushing.
[0066] Referring to FIG. 2 , the current embodiment is provided with a plurality of pipes which include the source water crossover pipe 26 , the clarifying or cleansing pipe 39 , and the backflush pipe 28 . Attached to the pipes are a series of control valves. As previously discussed, the crossover pipe 26 is positioned substantially at the bottom of the lower chamber 47 near the floor of the filtration tank 46 . Approximately midway between the filtration tank and the aeration tank the backflush pipe intersects the source water crossover pipe at a junction point. At this junction, the backflush pipe 28 is connected to a backflush valve 30 . The backflush valve 30 is a standard automated valve having a weir and a control box which operates the weir.
[0067] A clarifying pipe 39 is provided at the filter tank upper chamber to allow cloudy or turbulent water to be drained. The cleansing or clarifying pipe 39 leads from the filter tank upper chamber 45 and connects to the vertically lower backflush pipe 28 at a second junction. The clarifying pipe 39 also has a clarifying valve 30 with the same standard automated valve with a weir and control box as the back flush valve.
[0068] Referring now to FIG. 2 a , the alternative embodiment for the monitoring and cleaning system 35 includes the use of a backflush line 104 and a clarification line 106 . In this embodiment, the backflush line and the source water exit port 102 are separated to provide for a simpler operating system. The backflush line 104 is positioned at or near the bottom of the filtration tank 46 in the filtration tank lower chamber 47 . Connected to the backflush line 104 is a backflush valve 30 having a control box and weir, the control box being electronically operable by the programmable logic controller 36 . During normal operation, the backflush valve 30 is in its closed position keeping water within the filter tank 46 .
[0069] Providing a means of clarifying cloudy groundwater is a clarification line 106 . Within the upper chamber 45 of the filter tank, is a clarification port 108 , the port having a clarification line 106 . This clarification line also has a cleansing valve or clarification valve 38 which operates the same as the backflush valve 30 . After the turbulence in backflushing has occurred, a clarifying period is run which allows the finer particulate to settle out.
[0070] During normal operational flow the aerated water 9 will generally accumulate in the aeration tower 24 building up a pressure head 22 which drives the corresponding discharge rate out of the filtration tank 46 . The discharge rate stays relatively constant based on a discharge pressure which correlates to the pressure head 22 in the aeration tower 24 . The filter media 50 has a certain porosity between the actual media particles which will allow for only a maximum flow rate through the filter media 50 . The pressure head 22 in the aeration tower 24 will build until the flow rate through this filter media equals the pressure head from the aeration tower. As the filtered water 7 enters into the upper chamber 45 of the filter tank, it accumulates until the top layer of the water reaches the filtered water exit pipe 54 . This exit pipe 54 has enough cross-sectional area to maintain a constant volume of filtered water 7 within the filter tank 45 upper chamber.
[0071] As a natural consequence of filtering the iron or particulate out of the groundwater, the lower chamber 47 of the filter tank in the filter media 50 will accumulate the filtered particulate until such time as the filtering is ineffective. Also, the particulate will tend to reduce the flow rate through the filter media and the corresponding pressure head 22 will need to increase, thus building the height level of the aerated water within the aeration tower 24 .
[0072] Many geographic regions have significant amounts of soluble iron or manganese within the groundwater and therefore flushing of the lower chamber 47 of the filter tank can be beneficial for the life expectancy of the oxidation filtration system. There are many ways to monitor and trigger the backflushing of the filtration tank 46 . Speaking broadly, these include monitoring of the pressure head 22 as it increases in the aeration tank 24 , monitoring the filtered water quality 7 in the upper chamber 46 of the filter tank, monitoring the amounts of soluble compounds in the local groundwater supply to determine an optimal periodic backflushing setting.
[0073] To coordinate the sequence of monitoring and cleaning of the oxidation filtration system, an oxidation filtration monitoring and cleaning system 35 is provided that will now be discussed. Referring to FIGS. 2 and 2 a , the system utilizes a programmable logic controller in combination with a series of sensors and valves. The sensors monitor the water levels within the aeration tank 24 and the filtration tank 46 , and the valves control the opening and closing of the backflush line 104 and the clarification line 106 as well as the water source line 14 . The programmable logic controller coordinates the sequencing of opening and closing various valves as well as monitoring the water levels to stay within operational parameters.
[0074] During the course of filtration, an emergency such as a high-level water sensor may be engaged, the sensor then immediately sends from the PLC a signal to set off the alarm 111 and alert the owners of the of the system that there is high water levels within the aeration tower 24 . The PLC can also operate the solenoid of an oxidation filtration system control valve 212 which is designed to alternate the use of an off-line and online oxidation filtration system connected in series. This will be further discussed as seen in FIG. 7 below.
[0075] For remote operation, the PLC 36 is connected to a communications device 131 such as a modem. The modem 131 allows a remote client 133 to connect to the operating system of the PLC 36 and operate the control application 132 .
[0076] The control application 132 is configured to allow for varying control and sensor settings for the various oxidation filtration systems 10 . The control application 132 is configured to operate the control components including the valves and sensors of the various oxidation filtration systems such as oxidation filtration system applications 1 through 3 , FIG. 6 .
[0077] Because each oxidation filtration system 10 has essentially the same sensors 136 and control devices 138 , the control application can implement a sub-application such as oxidation filtration system application 1 , 140 , the sub-application will then draw from a series of class objects 146 as seen in FIG. 6 , to implement an instance of the particular control application 132 of the specific system 140 .
[0078] Of course other programming paradigms may be used such as a non-object-oriented programming language including Basic, Fortran, or an assembly programming language specifically designed for the programmable logic controller.
[0079] Still discussing FIG. 6 , the functions or objects which run for each system include a back flush time 148 , where the back flush time indicates the time of day the oxidation filtration system 10 will initiate a system flush. Referring back to FIG. 2 a , the programmable logic controller 36 will send a signal to the back flush valve 30 to open the valve and discharge the water in the filtration tank 46 and aeration tower 24 . The water in both tanks will provide enough pressure head to turbulantly force the water out through the back flush line 104 . This turbulence within the lower chamber 47 of the filter tank 46 will wash the filtration media 50 of most of the accumulated particulate.
[0080] The users can also set a period of time for the back flushing to take place. This is considered the back flush cycle 150 . The back flush cycle tells the programmable logic controller 36 how long the back flush valve 30 is to stay open. Similarly, and referring back to FIG. 6 , after the back flush has occurred the control application 132 will indicate to the programmable logic controller 36 the amount of time that the clarification valve 38 is to remain open so that the system can clarify the water previously back flushed. The clarification cycle or timer 152 can be set by the user usually to approximately 20 minutes.
[0081] The control objects class 146 also contains a setting for emergency back flush 154 . This occurs when one of the high-level sensors within the aeration tower 24 such as the diaphragm sensor 107 as seen in FIG. 2 a , signals to the PLC 36 that the pressure head 22 within the aeration tower 24 has increased beyond acceptable limits and the system must be back flushed. Thus the emergency back flush object 154 will signal the programmable logic controller to operate the back flush valve 30 and begin the flushing cycle. Also, a manual back flush object 156 is provided so that the users can either remotely through the remote client 133 or at the display screen of the programmable logic controller 36 operate a manual back flush of the entire filtration system 10 .
[0082] An additional control object within the control application 132 is a calibration for normal back flush time 158 . This calibration for normal back flush time calculates the mean or the average time between the system back flushes, and provides an optimization or recommended setting for the back flush time object 148 . This calibration for normal back flush time 158 is beneficial because as previously discussed, each geographic region which requires the oxidation filtration services has different levels of soluble compounds and thus requires different frequencies for washing or cleaning of the filter media 50 as seen in FIG. 2 a.
[0083] To keep the filtration system running relatively smoothly, a high-level delay object 162 is provided. During the course of operation, the aeration tower 24 may experience high-level water false-starts or in other words false warnings, which have been triggered from splashing or a short period of reduced filtration flow. The high-level delay object 162 allows the user to set the amount of time that the high water float 34 or the diaphragm sensor 107 must be activated or raised before the emergency back flush object 154 will signal the back flush valve 30 to begin the system flush.
[0084] To notify the system operator or the owner of the oxidation filtration device that an unscheduled back flushing event has occurred, a series of alarms have been designed to communicate the emergency status. After a signal has been received from one of the sensors 136 as seen in FIG. 5 , the control application 132 as seen in FIG. 6 , will activate an alarm object 160 . The alarm object will then send a control signal to the physical alarm 101 as seen in FIG. 2 a which in the current embodiment is attached to the top cover plate of the filter tank 46 . The alarm 111 has a flashing warning light as well as a sound/audible warning.
[0085] The alarm object 160 has an alarm delay which delays the audible alarm initiation. This delay allows response from the pager alarm discussed below from irritating or annoying residents within the vicinity of the oxidation filtration system. The alarm object 160 will also send a signal through the communications device or modem 131 to a pager service located at a remote client 133 which then notifies the owner of the high-level emergency. The alarm object 160 has an audible silence control which when activated allows the operator to work on the emergency system without the audible alarm causing a distraction. If the high-level emergency is not corrected within a period of time, the audible alarm will then re-activate until such time as the back flush occurs.
[0086] In addition to servicing dairy farms and other agricultural operations, the oxidation filtration system 10 can also be used to process groundwater for a small municipality. The current embodiment provides for each filtration unit to process approximately 25,000 gallons to 30,000 gallons per day. An average person will typically use between 75 to 100 gallons of water per day. Therefore, the typical 25,000 gallon processing filtration unit can service approximately 250 people each day. To service between 1,000 people to 2,500 people equating to a small municipality or medium-size subdivision, having between five and ten filtration units running in parallel producing between 125,000 gallons to 250,000 gallons of filtered water each day would be beneficial to the local governmental authority.
[0087] The current preferred embodiment for the oxidation filtration tank assembly 250 as seen in FIG. 7 has arranged a three unit filtration output in parallel, with two units for each output line in series. This tank assembly configuration 250 allows the users to perform maintenance on one of the off-line filtration tanks while still producing filtered water through the online tank.
[0088] The system can produce approximately 75,000 gallons of water constantly per day. The current embodiment of the programmable logic controller 36 can coordinate five filtration tanks in parallel. The tanks currently producing filtered water and the assembly as shown in FIG. 7 are online tank 1 at 200 , online tank 2 at 204 , and online tank 3 at 208 . The groundwater source line 14 provides the groundwater through an oxidation filtration system control valve 212 . The programmable logic controller 36 monitors the operation of the online tanks and if a back flushing sequence occurs or the tank goes off-line, then the PLC will signal the oxidation filtration system control valve 212 to redirect the groundwater from the groundwater source line 14 to the backup system such as backup oxidation filtration system 202 to keep the production output at a constant rate. Also, by having a plurality of filtration tanks in series and parallel, the assembly 250 is in a better position to meet peak load demands and low load demands based on daily population needs.
[0089] A brief discussion of the overall process or method as it operates in the current embodiment will now be provided.
[0090] Reference will be made to FIGS. 2 through 7 including the alternative embodiments of 2 a through figures for a period. Referring first to FIG. 7 , the oxidation filtration tank assembly 250 of the current embodiment is arranged in a three parallel output filtration configuration with each parallel output line having 2 filtration tanks in series. The groundwater flows through the groundwater source line 14 and is directed through each of the oxidation filtration system control valves 212 to the online oxidation filtration system tank. Pressure in the source line 14 is provided by the source line pump and the pressure can be read on the pressure meter 20 as seen in FIG. 2 . The operator can initiate the filtration process by first turning on the source line valve 19 by either utilizing the programmable logic control application 132 through a remote client 133 or by using a manual valve handle. The water is immediately injected into the Venturi-type aerator 15 and after the initial aeration, the groundwater passes through the spray nozzle 16 and falls into the aeration tower upper zone 23 . The groundwater is further aerated by dropping through the aeration tower 24 to the bottom of the tower. The groundwater then after being aerated enters into the lower chamber 47 of the filter tank 46 either through the source water crossover pipe 26 or through the exit port 102 as seen in FIG. 2 a . The water level in the filter tank lower chamber 47 and the aeration tower 24 continues to rise at an equal constant rate until the filter tank lower chamber 47 is full. During this initial filling process, the filter tank lower chamber 47 containing the filter media 50 filters the water through the filter media and the filter media is pressed or pressurized against the media mesh 52 dividing the upper chamber from the lower chamber.
[0091] At this stage, the source groundwater 12 begins to fully filter through the filter media 50 as the water pressure static head 22 in the aeration tower 24 begins to increase forcing the water through the filter media and beginning the filter rate of the source groundwater through the media until a steady-state flow rate is reached.
[0092] The surface area of the individual filter media is such that it readily attracts the iron oxide particles thus taking the particulate out of the groundwater. The aerated water 12 filters through the filter media and enters into the upper chamber 45 of the filtered tank 46 . The filtered water contained within the upper chamber 45 will exit through the filtered water crossover pipe 54 or the exit port 54 and dropped into a holding tank 48 .
[0093] Filtering of the groundwater continues unimpeded for the filtering cycle until such time as the filtration rate through the filter media decreases. As the filter rate slows, the static head pressure 22 in the aerated tower 24 begins to build. At a certain point the static head pressure 22 reaches the high-level flow 34 or the diaphragm sensor 107 and then sends a back flush or discharge signal from the back flush sensor 32 or diaphragm sensor 107 to the programmable logic controller 36 .
[0094] At this point in the process, the programmable logic controller runs the control application 132 for the particular oxidation filtration system 140 . Depending on the operational settings held within the various control objects 146 the alarm 111 may be delayed from sounding because the users may have set the high-level delay 162 to for example five minutes. Simultaneously, the control application 132 will send a pager signal 164 through the modem 131 to the remote client 133 which in this case would be the pager of the on-site operator. The pager would then notify the operator of the emergency situation and the operator could take a number of actions. One of the actions would be for the operator to access the control application 132 through the remote client 133 connected to a modem 131 . The operator could then check the system status of the particular oxidation filtration system to determine if the alarm signal is an actual high-level emergency or is just a false alarm.
[0095] The operator can then verify that the water pressure level 22 in the aeration tower 24 has reached the high-level flow 34 or the diaphragm sensor 107 and a back flush or system flush should be initiated. After the back flush has been initiated, the operator can direct the programmable logic control 36 to send a signal to the oxidation filtration system control valve 212 as seen in FIG. 7 , to switch the groundwater source 14 from the back flushing oxidation filtration system 200 to the backup oxidation filtration system 202 .
[0096] The calibration for the normal back flush time 158 will then take place recalculating the average amount of time between back flushes and reset the back flush time object 148 . This recalibration can occur for each of the oxidation filtration systems within the assembly 250 .
[0097] The filtration will continue until the back flush time 148 signaled to the programmable logic controller 36 that a back flush cycle 150 should occur. The programmable logic controller will then signal the back flush valve 30 . Referring to FIGS. 3 and 3 a , the solenoid of the back flush valve 30 will open the valve and the back flushing process will begin again. The static pressure head 22 within the aeration tower 24 as well as the filtered tank static pressure head 56 create a substantially large flow rate through the back flush line 104 and creating significant turbulence 51 in the lower chamber 47 of the filtered tank 46 . This turbulence 51 buffets and washes the filter media 50 as the groundwater contained within the aeration tower 24 in the filtration take 46 quickly exit through the back flush line 104 .
[0098] This process of back flushing and rinsing the filter media 50 occurs for the entire period of the back flush cycle timer 150 as set in the control application 132 . After the time period has elapsed, the programmable logic controller then signals the clarification valve 38 as seen in FIGS. 4 and 4 a to open and simultaneously closes the back flush valve 30 allowing the water pressure from the source line 14 to accumulate in the aeration swap tower 24 and the filter tank 46 . The filter media 50 has been washed of the oxidation deposits and returns to its buoyant state.
[0099] Because of the significant turbulence which occurred in the back flushing process, iron or other particulate is suspended within the groundwater and may be residual in the upper chamber 45 and the lower chamber 47 of the filter tank 46 . In lieu of waiting for the dislodged particulate to settle out, a clarification process is provided where the clarification port 108 in the upper chamber 45 is opened to clean and dispose of the cloudy groundwater 70 .
[0100] The control application runs the clarification cycle for the desired period of time as set in the clarification cycle timer object 152 . Alternatively, the particulate sensor 103 can monitor the level of particulate within the upper chamber 45 as directly after the back flushing process to then send a signal to the programmable logic controller that the clarification cycle should terminate.
[0101] However the clarification period 152 is determined, the cloudy water 70 exits through the clarification line 106 for the clarification cycle 52 until the cycle is complete. One embodiment has this cycle lasting approximately 30 minutes. After the clarification cycle is complete, the clarification port 38 is closed by the programmable logic controller sending a signal to the solenoid of the clarification valve to close the aperture.
[0102] Once the entire flushing cycle has taken place, the groundwater within the aeration tower 24 is allowed to build up pressure head 22 until such time as the filtration rate reaches its normal equilibrium state and filtration of the groundwater continues.
[0103] After continuous use of the oxidation filtration tanks 10 , such as for a year or two, maintenance of the oxidation filtration back flush assembly or tank 10 may be required. The accumulation of the iron particulate or other crud may occur generally within the crossover pipe 26 or block the exit port 102 as seen in FIGS. 2 and 2 a . Consequently, either a plurality of cleanout pipes 72 is provided or cleanout ports within the bottom chamber of the filter tank 46 are provided.
[0104] Each cleanout pipe section 72 is attached to a manifold 74 with a gasket 76 . When the crossover pipe 26 becomes clogged with particulate, the operator can shut down the system and remove the cleanout pipes 72 . Similarly, when the exit port 102 becomes clogged and the aeration tower 24 can no longer pass water from the aeration tower into the lower chamber of the filter tank 47 , the operator can shut down the entire process, remove the filter tank cover and extract the aeration tower 24 from the interior of the filter tank. The media mesh 52 can be removed and cleanout of the filter tank and of the aeration tower can occur relatively inexpensively. This use of maintenance allows for long life of the oxidation filtration tank 10 . | An oxidation filtration system for cleaning groundwater, the system having an aeration tower and a filtration tank. Within the filtration tank is an upper chamber and a lower chamber. Contained within the lower chamber is a plurality of Styrofoam™ filter media. Separating the upper chamber from lower chamber is a filter media mash which keeps the filter media from entering into the upper chamber. The aerated water from the aeration tower enters into the base of the lower filter chamber and rises through the filter media into the upper filter chamber. As the water passes through the filter media, the dissolved solvents fallout of the groundwater and attach themselves to the Styrofoam™ media. An automated back flushing and clarifying process is also provided using a back flush port and a clarification port, a higher level water sensor in the aeration tower and a programmable logic controller. The controller opens and closes the back flush and clarification port depending on the settings within the resident software, the controller interfaces with a remote computer to remotely operate the back flushing, clarification and filtering of the groundwater. The controller receives signals from the sensor to determine emergency back flushing requirements. The controller operates at a minimum one, and maximum five oxidation filtration systems at one time. | 2 |
FIELD OF THE INVENTION
The present invention relates to an anti-lock control method for preventing locking of wheels at the time of braking operation of the vehicle.
BACKGROUND OF THE INVENTION
In general, with an anti-lock control device for a vehicle, anti-lock control is effected by means of a microcomputer such that hold valves and decay valves are opened and closed on the basis of electrical signals representing wheel speeds detected by wheel speed sensors, thereby increasing, holding or decreasing the brake hydraulic pressure, for the purpose of securing improved steering performance and running stability, while at the same time reducing the braking distance of the vehicle.
FIG. 1 shows control state diagrams as disclosed in U.S. Pat. No. 4,741,580 which illustrate the changes in the wheel speed Vw, the wheel acceleration and deceleration Vw and the brake hydraulic pressure Pw, as well as a hold signal HS and a decay signal DS for opening and closing the hold valves and the decay valves.
In a state of the vehicle in running where no brake is operated, the brake hydraulic pressure Pw is not increased and both of the hold signal HS and the decay signal DS are in the off-state, so that the hold valve is in the open state whereas the decay valve is in the closed state. However, with a brake operation, the brake hydraulic pressure Pw increases rapidly from time point t0 (normal mode), reducing the wheel speed Vw. There is set up a reference wheel speed Vr which is lower by a predetermined amount ΔV than the wheel speed Vw and follows the latter with such a speed difference. The reference wheel speed Vr is set up so that when the wheel deceleration (negative acceleration) Vw of the wheel attains a predetermined threshold value, -1G, for instance, at a time point t1, it decreases linearly in time from the time point t1 with a slope θ for the deceleration of -1G.
At a time point t2 when the wheel declaration Vw reaches a predetermined value -Gmax with maximum absolute value, the hold valve closes by turning on the hold signal HS to hold the brake hydraulic pressure Pw.
With the holding of the brake hydraulic pressure Pw in such a manner, the wheel speed Vw further decreases to become less than the reference wheel speed Vr beyond a time point t3. At that time point t3 the decay signal DS is turned on to open the decay valve to start reducing the brake hydraulic pressure Pw. As a result of the pressure reduction, the wheel speed Vw is shifted from decrease to increase at a time point t4 when a low peak Vl of the wheel speed Vw occurs. At the time point t4 of the low peak, the decay signal DS is turned off to close the decay valve, so that the reduction of the brake hydraulic pressure Pw is completed and the brake hydraulic pressure Pw is held at the value at that time.
Next, when the wheel speed Vw attains a high peak Vh at a time point t7, an increase in the brake hydraulic pressure takes place again. The pressure increase in the brake hydraulic pressure Pw and the decrease in the wheel speed Vw in this stage is arranged to take place gradually by a repetition of turning on and off of the hold signal HS mincingly. Starting at a time point t8 (corresponding to t3) a decompression mode is generated again.
It is to be noted that during the above operation, a time point t5 is detected at which the wheel speed Vw is recovered to a speed Vb(=Vl+0.15Y) where Vl is the wheel speed at the low peak and Y is the difference between the wheel speed Va at the time point t3 and the low peak speed Vl, so that Vb represents the wheel speed at which 15% of the speed difference Y is gained from the low peak value Vl. Also, a time point t6 is detected at which the wheel speed increases to Vc(=Vl+0.8Y) where 80% of the speed difference Y is gained from the low peak speed Vl. Further, the interval Tx of the first pressurization which starts at the time point t7 is determined by the judgment of the friction coefficient μ of the road surface as obtained based on the computation of the average acceleration (Vc-Vb)/ΔT for the period ΔT between the time points t5 and t6. In addition, the holding periods or the pressurization periods that follow are determined based on the vehicle deceleration Vw that are detected immediately before each holding or pressurization. Through a combination of augmentation, holding and reduction of the brake hydraulic pressure Pw as described in the above, it is possible to reduce the vehicle speed by controlling the wheel speed Vw without causing the locking of the wheels.
Now, as is clear from the above description, in the conventional anti-lock control method, the threshold value of deceleration at which the reference wheel speed Vr is to be changed to have a certain deceleration slope in order to increase the S/N rate in consideration of the road surface noise and the like, is selected at a value, -1 G, for example, which has a greater absolute value than that of the vehicle speed generated in the normal deceleration. Then, the reference wheel speed Vr is reduced starting with the time point t1 with the deceleration slope θ for -1G based on the detection of the predetermined threshold value -1G of deceleration of the wheel speed Vw, and the reduction of the brake hydraulic pressure Pw starts from the time point t3 at which the wheel speed Vw becomes equal to the reference wheel speed Vr. Because of this, if a gentle braking is performed such that the wheel speed Vw decreases with a deceleration Vw which will not attain the predetermined value of -1G, -0.7 G, for example, the reference speed Vr which merely follows the wheel speed Vw with a speed difference of ΔV will never come to cross the wheel speed Vw. Then, speed reduction will continue independent of the vehicle speed without detecting the pressure reduction point for the brake hydraulic pressure Pw. As a result, there was a possibility of generating a premature locking of the wheels in case when the vehicle runs on a road surface with a small value of friction coeficient μ.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an anti-lock control method for a vehicle which makes it possible to carry out an optimum control in response to all kinds of road surface conditions.
One of the features cf the present invention is that a variety of statuses are set by distinctly segmenting the conditions for each status in order to carry out anti-lock control.
In the present invention, when the wheel speed Vw which is decelerated by an increase in the brake hydraulic pressure attains a predetermined deceleration, there is set up a reference wheel speed Vr which decreases linearly in time with the predetermined deceleration from a speed (Vw-ΔV) that is lower than the wheel speed Vw by a predetermined amount ΔV. At the same time, there are set a first threshold speed VT1 and a second threshold speed VT2 which follow a computed vehicle speed Vv with predetermined speed differences so as to satisfy the relation Vv>VT1>VT2.
Further, the starting time of the decompression status is chosen to be the time whichever is the sooner between the time point at which the wheel speed Vw becomes equal to or lower than the reference wheel speed Vr and the time point at which the wheel speed Vw becomes equal to or lower than the first threshold speed VT1. The completion time of the decompression status is chosen to be the time whichever is the sooner between the time point at which the wheel speed Vw attains its low peak and the time point, when the wheel speed Vw had become equal to or lower than the second threshold speed VT2, at which the wheel speed Vw becomes equal to or lower than the second threshold speed VT2 again.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a timing chart for the conventional anti-lock control method;
FIG. 2 is a block diagram for the control system as applied to an embodiment of anti-lock control in accordance with the present invention;
FIG. 3 is a timing chart for the control; and
FIG. 4 is a flow chart.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, an embodiment of the present invention will now be described in detail below.
FIG. 2 is a block diagram for the control system according to the embodiment of the present invention. In the system shown in FIG. 2, a wheel speed sensor 1 is provided for each of the four wheels, a control unit 2 consists of a computer, a master cylinder 3 is operated by a brake pedal 4, a modulator 5 includs a hold valve 6 which is a normally-open type solenoid valve and a decay valve 7 which is a normally-closed solenoid valve, a reservoir 8 reserves brake fluid which is pumped up to be stored in an accumulator 10. Further, the system comprises a brake switch 4a which is closed by stepping on the brake pedal 4, and a wheel cylinder 11 of the brake device for the wheel.
The control unit 2 includes wheel speed computing means 12 for computing the wheel speed Vw from the output of each wheel speed sensor, computed (pseudo) vehicle speed computing means 13 which selects the highest wheel speed (select-high) out of the four wheel speeds Vw, and obtain a computed vehicle speed Vv through filters with acceleration and deceleration ±1G, and threshold value computing means 14 for computing a first threshold speed VT1 and a second threshold speed VT2 that follow the computed vehicle speed with respective predetermined speed (Vv>VT1>VT2). Moreover, the control unit 2 includes acceleration and deceleration computing means 15 for computing the acceleration and deceleration Vw of the wheel speed Vw, and reference wheel speed computing means 16 for computing a reference wheel speed Vr which decreases from a speed obtained by subtracting a predetermined amount ΔV from the wheel speed Vw, with the deceleration for -1G. The control unit 2 also includes a control circuit 17 which executes augmentation, holding and reduction of the brake hydraulic pressure within the cylinder 11 by controlling the opening and closing of the hold valve 5 and the decay valve 6 based on the outputs from the respective means 12 to 16.
Next, referring to FIG. 3 showing the timing chart for control in each of the status and FIG. 4 showing the control flowchart, an example of the anti-lock control in accordance with the present invention will be illustrated. Here, it should be noted that the control of the brake hydraulic pressure in the present invention will be carried out in the case, for example, of a vehicle equipped with a dual circuit brake system of X-piping type, the left-front wheel and the right-rear wheel are grouped to form one system and the right-front wheel and the left-rear wheel are grouped to form another system, and the wheel speed on the low speed side in each system is considered to represent the wheel speed of control object (system speed), with the modulation 5 belonging to each system being controlled.
STATUS 0
This status is defined as the interval from a time point A at which the brake switch 4a is closed by the stepping on the brake pedal to a time point at which there is generated a reference wheel speed Vr which decreases linearly through attaining by the deceleration Vw of the wheel speed a predetermined deceleration value (-1G, for example). The hold valve is in an open state while the decay valve is in the closed state, so that the brake hydraulic pressure within the wheel cylinder 11 will rise by the brake fluid supplied from the master cylinder 3.
STATUS 1
This status is defined to cover from the time point B of the reference wheel speed Vr to a time point C at which it is judged that the deceleration Vw of the wheel speed attained a predetermined deceleration Gmax. In this status the hold valve 6 and the decay valve 7 are inoperative.
STATUS 2
Holding
This status is defined to cover from the judging time point C of Gmax to the time point whichever may be the sooner between the time point at which the wheel speed Vw becomes equal to or lower than the reference wheel speed Vr (decompression point a) and the time point at which the wheel speed Vw becomes equal to or lower than the first threshold speed VT1 (decompression point b). The hold valve 6 closes at the time point C, and the brake hydraulic pressure is held during the status. It is to be noted that in FIG. 3 the status 2 terminates at the time point D when the wheel speed Vw is about to be overtaken by the reference wheel speed Vr. However, if the wheel speed Vw is to be overtaken by the first threshold speed VT1 prior to the time point D, the status 2 will be terminated at that time point.
STATUS 3
Decompression
This status is defined to cover from the time point D at which the wheel speed Vw becomes equal to or lower than the reference wheel speed Vr to a time point E at which the wheel speed Vw becomes equal to or lower than the first threshold speed VT1. The decay valve 7 opens at the time point D, and a decompression of the brake hydraulic pressure will be started.
STATUS 4
Decompression
This status occur when the control cycle is in a second or later cycle and the absolute value of the deceleration Vv of the computed vehicle speed Vv is lower than -0.22G. The Status 4 is defined to last from the time at which the wheel speed Vw becomes equal to or lower than the first threshold speed VT1 to the time one of the following conditions is fulfilled.
(1)When a decay timer which was set at the start of the decompression counts up its time in order to prevent an excessive decompression.
(2) When the wheel speed Vw becomes equal to or lower than the second threshold speed VT2.
(3) When the wheel speed Vw is judged to have attained a low peak.
STATUS 5
Decompression
This status occurs when the control cycle is in a first cycle or when the absolute value of the deceleration Vv of the computed vehicle speed Vv is greater than -0.22G. It is defined to cover the period from a time point E at which the wheel speed Vw is about to be overtaken by the first threshold speed VT1 to the sooner of a time point F at which the wheel speed Vw is judged to have attained a low peak and a time point F' at which the wheel speed Vw becomes equal to or lower than the second threshold speed VT2.
STATUS 6
Decompression
This status is defined during the period when the wheel speed Vw is lower than the second threshold speed VT2, namely, from the time point F' to the time point F" in the figure.
STATUS 7
Holding
The condition for the start of this Status 7 is considered to satisfy one of the following.
(1) When the occurrence of a low peak is judged in the Status 4 or 5.
(2) When the decay timer in the Status 4 counts up its time.
(3) When the wheel speed Vw becomes higher than the second threshold speed VT2 in the Status 6 (time point F").
The Status 7 is defined to cover the period from a time point at which one of the above condition is satisfied to a time point G at which the wheel speed Vw becomes equal to or higher than the first threshold speed VT1.
It is to be noted that if in the condition of the Status 7 the wheel speed Vw fails to overtake the first threshold speed VT1 after elapse of a predetermined time T1, it goes to Status 4 to carry out a decompression all over again.
STATUS 8
Holding
This status is defined to cover the period from a time point G at which the wheel speed Vw becomes higher than the first threshold speed VT1 to a time point H at which the wheel speed Vw attains the speed (Vv-ΔV0) which is lower than the computed speed Vv by a predetermined value ΔV0.
It should be noted that when in Status 8 the wheel speed Vw fails to overtake the speed (Vv-ΔV0) after elapse of a predetermined time T2, it goes to Status 11 to be set to a slow building (described later).
STATUS 9
Fast Building
This status is defined to cover the period from a time point H at which the wheel speed Vw becomes greater than the speed (Vv-ΔV0) to a time point I which corresponds to elapse of a predetermined time T3 after the time point H. During this status, the brake hydraulic pressure increases relatively rapidly by opening and closing the hold valve 6 mincingly.
STATUS 10
Slow Building
This status is defined to cover the period from a time point I at which the fast building ends to a time period J at which the reference wheel speed Vr is generated. During the Status 10, the brake hydraulic pressure increases gradually by opening and closing the hold valve 6 using longer closing times.
STATUS 11
Slow Building
This status is defined to cover the period from the time point J at which the reference wheel speed Vr is generated to the time point whichever is the sooner between a time point at which the wheel speed Vw becomes equal to or lower than the reference wheel speed Vr and time point at which the wheel speed Vw becomes equal to or lower than the first threshold speed VT1. In other words, although the situation is shown in FIG. 3 in which the Status 11 terminates at a time point K at which the wheel speed Vw is about to be overtaken by the first threshold speed VT1, if the wheel speed Vw is to be overtaken prior to the time point K, then the Status 11 will terminate at that time point. When the Status 11 terminates, it goes to the Status 4 or 5.
According to the status of the present invention, control of the wheel speed is carried out by setting numerous statuses and segmenting the conditions distinctly for each status, so that it is possible to execute an optimum anti-lock control for all circumstances conceivable.
Moreover, a first threshold speed VT1 and a second threshold speed VT2 that are based on a computed vehicle speed Vv are set along with the setting of a reference wheel speed Vr that determined the time point at which a decompression of the brake hydraulic pressure is started. Therefore, even when the deceleration of the wheel speed Vw is carried out gradually, the decompression is arranged to take place as soon as the wheel speed Vw becomes equal to or lower than the first threshold speed VT1, so that it is possible to obtain always a stabilized starting point of decompression. When the wheel speed Vw is decreased rapidly, the time point at which the wheel speed Vw becomes equal to or lower than the reference wheel speed Vr is set as the time at which depression is to be started, so that it is possible to start decompression without delay.
Further, since the decompression region is defined to begin when the wheel speed Vw becomes equal to or lower than the second threshold speed VT2, even when the friction coefficient μ of the road surface a sudden change from a high to a low value μ there can be obtained a sufficiently long decompression time after switching to the low μ value. Therefore, it is possible to prevent efficiently the locking of the wheels. | An anti-lock control apparatus for a vehicle, comprising, a sensor for sensing wheel speeds of the vehicle, a braking system for braking the vehicle wheels, and a controller for controlling the braking system, according to an output of the wheel speeds sensors. The controller set a vehicle speed, a first and second threshold speeds, whereby the first and second threshold speeds follow over time the vehicle speed with a constant prescribed speed difference so as to satisfy the relation Vv>VT1>VT2, where Vv, VT1 and VT2 represent the vehicle speed, first and second threshold speeds, respectively. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit under 35 U.S.C. § 119 of Japanese Patent Application No. 350477/2004, filed Dec. 2, 2004, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to coated printing papers having good printability, good color print quality and air cleaning effect, especially those on which news ink is used.
[0003] Against the background of growing demands for removing harmful substances in daily life such as offensive odors, along with a growing awareness of the need to protect the environment, titanium oxides are drawing attention. Such oxides have been conventionally used as pigments for papermaking on account of their good opacity; and techniques for supporting fine titanium oxides on paper are under development in order to effectively utilize their known ability to induce redox reactions by using light energy to decompose various harmful substances in the atmosphere. For example, a photocatalytic paper internally containing a water-soluble polymer and a photocatalytic material such as a titanium oxide has been disclosed (see patent document 1), but the inclusion of a photocatalytic material within paper layers is neither efficient nor sufficiently effective because it produces its catalytic effect by exposure to light. In order to increase catalytic efficiency, it is thought that a photocatalytic material should be supported as close as possible to a paper surface; or most effectively, paper should be coated with the material. For example, a method has been disclosed by which fine titanium oxide are bonded to an inorganic binder such as colloidal silica and bonded around it by an organic adhesive (see patent document 2). However, such paper is not common and there is limited incentive to use them in view of current environmental awareness. Photocatalytic technologies would be most effectively utilized if they could be applied to e.g., the cover pages of newspapers because currently the most common papers are printing papers, and especially newspapers are published everyday.
[0004] Recently, with the growth of various printing technologies there is a growing trend in employing multicolor printing and using printing press with greatly improved printing speed. This tendency is also seen in newspaper printing. Multicolor printing of newsprint paper takes place under conventional printing conditions, i.e. penetration drying type inks are used for printing on conventional newsprint by high-speed coldset rotary presses to meet the need for immediate mass printing typical of newspaper printing and for cost-related reasons. However, when paper is coated by conventional methods, the ink drying properties of the paper are very poor. Therefore, when using penetration drying type inks on such paper printed by high-speed coldset rotary presses, there remains some undried ink which is deposited on guide rolls and transferred to the paper which will cause the final quality to deteriorate.
[0000] References
[0005] Patent document 1: JPA HEI 10-226983.
[0006] Patent document 2: JPA 2000-129595.
[0007] Under such circumstances, an object of the present invention is to provide coated printing papers having fast ink drying properties comparable to those of conventional newsprint, without stickiness, having good printability such as sharpness of printed images comparable to those of coated papers, as well as having the effect of decomposing harmful substances by exposure to light, especially when using penetration drying type news inks.
SUMMARY OF THE INVENTION
[0008] As a result of careful studies to achieve the above object, we found that a coated printing paper having good ink drying properties of prints, little stickiness, good printability, and good reproducibility and sharpness of color printed images, as well as having the effect of decomposing harmful substances by exposure to light can be obtained by providing a coated paper comprising a coating layer containing a pigment and an adhesive on a base paper wherein a fine titanium oxide having a photocatalytic effect is contained in the coating layer and the coated paper has an oil absorbency of 20 g/m 2 or more under pressure and a Bekk smoothness of 75 seconds or less. It is thought that retransfer to rolls of printing press or the like or the resulting stain on the surface of printing can be reduced by adjusting the coated paper at an oil absorbency under pressure of 20 g/m 2 or more and a Bekk smoothness of 75 seconds or less because news inks or the like moderately penetrate the coated paper during printing to contribute to good ink receptivity and ink drying properties and reduced stickiness and inks are deposited on the surface of the coated paper having low smoothness. In the present invention, the base paper preferably contains an organic compound having the effect of inhibiting interfiber binding of pulp. Preferably, the fine titanium oxide is contained at 5 parts by weight or more and the fine titanium oxide and calcium carbonate are contained at 30 parts by weight or more per 100 parts by weight of the pigment.
[0000] Advantages of the Invention
[0009] According to the present invention, coated printing papers can be obtained having fast ink drying properties comparable to those of conventional newsprint, without stickiness, having good printability such as sharpness of printed images comparable to those of coated papers, as well as having the effect of decomposing harmful substances by exposure to light, especially in printing using penetration drying type news inks.
DETAILED DESCRIPTION OF THE INVENTION
[0010] In the present invention, coated printing paper having defined smoothness and oil absorbency are obtained by coating a specific pigment on a base paper.
[0011] It is important that the coated printing paper of the present invention has a Bekk smoothness of 75 seconds or less. If the Bekk smoothness is more than 75 seconds, the paper surface becomes stained, resulting in poor printability. This is probably because the inks supplied to the paper surface during printing may be retransferred to rolls of printing press or the like once they have been transferred to the printing paper and thereby the paper surface is more likely to be stained in the case of paper with high smoothness in contrast to papers with low smoothness in which inks are less likely to be transferred. More preferably, the Bekk smoothness is 10 seconds or more and 60 seconds or less.
[0012] It is also important that the coated printing paper of the present invention has an oil absorbency of 20 g/m 2 or more under pressure. The method for measuring the oil absorbency under pressure in the present invention uses AA-GWR Water Retention Meter from KALTEC. A coated paper test sample, a membrane filter (pore size 5.0 μm), and the accessory cup are placed in the instrument, and 1 ml of soybean oil is added from the top, and then the cup is tightly closed under a constant pressure (50 kPa) for a determined period (20 seconds), and then the amount of oil adsorbed into coated paper is measured. Normally, ink drying properties, i.e., the oil absorbency of papers is typically evaluated from the oil drop absorbency measured at normal pressures. However, actual printing conditions were not simulated and no definite correlation with printability such as paper surface stain or stickiness was observed by the oil drop absorbency measured at normal pressures because the inks on the blanket in offset rotary presses in fact set on paper under pressure between upper and lower cylinders. No correlation with printability is observed again according to JIS P 8130 defining a pressure set type oil absorbency test method. It was found that high correlation with printability is obtained by using the method of the present invention as described above. If the oil absorbency under pressure is less than 20 g/m 2 , news inks are less likely to penetrate the coated paper during printing, resulting in poor ink receptivity on one side of the coated paper and poor ink drying properties to cause staining on the printed surface or stickiness. If the oil absorbency under pressure is too high, inks excessively penetrate the coated paper, resulting in decreased ink receptivity and poor reproducibility and sharpness of prints. The coated papers preferably have an oil absorbency of 25 g/m 2 or more and 250 g/m 2 or less under pressure.
[0013] The base paper in the present invention comprises pulp, fillers and various additives. Chemical pulp, mechanical pulp, de-inked pulp and the like can be used, but mechanical pulp and waste paper pulp derived from mechanical pulp are preferably contained at 60% by weight or less, most preferably not contained because they deteriorate and discolor upon exposure to light when they are excessively used.
[0014] In the base paper of the present invention, a bulking agent (density reducing agent) such as a surfactant is preferably used as an organic compound having the effect of inhibiting interfiber binding of pulp to reduce the density of the base paper and to balance oil absorbency and smoothness. The organic compound having the effect of inhibiting interfiber binding of pulp (hereinafter simply referred to as binding inhibitor) means a compound having a hydrophobic group and a hydrophilic group, and suitable binding inhibitors for the present invention are density reducing agents (or bulking agents) recently introduced on the market to increase the bulk of paper for papermaking, including e.g., compounds disclosed in WO98/03730, JPA HEI 11-200284, JPA HEI 11-350380, JPA 2003-96694, JPA 2003-96695, etc. Specifically, ethylene and/or propylene oxide adducts of higher alcohols, polyvalent alcohol-type nonionic surfactants, ethylene oxide adducts of higher fatty acids, ester compounds of polyvalent alcohols and fatty acids, ethylene oxide adducts of ester compounds of polyvalent alcohols and fatty acids, or fatty acid polyamide amines, fatty acid diamide amines, fatty acid monoamides, or condensation products of polyalkylene polyamine/fatty acid/epichlorohydrin can be used alone or as a combination of two or more of them. Ester compounds of polyvalent alcohols and fatty acids, fatty acid diamide amines, fatty acid monoamides, condensation products of polyalkylene polyamine/fatty acid/epichlorohydrin or the like are preferred. Commercially available bulking agents include Sursol VL from BASF; Bayvolume P Liquid from Bayer; KB-08T, 08W, KB110, 115 from Kao Corporation; Reactopaque from Sansho Co., Ltd.; PT-205 from Japan PMC Corporation; DZ2220, DU3605 from NOF Corporation; R21001 from Arakawa Chemical industries, Ltd., and these can be used alone or as a combination of two or more of them. The coated papers of the present invention preferably contain 0.1-10 parts by weight, especially 0.2-1.0 parts by weight of an inhibitor of interfiber binding of pulp per 100 parts by weight of the base paper to improve air permeability of the base paper.
[0015] In the present invention, known fillers such as amorphous silicates, amorphous silica, talc, kaolin, clay, precipitated calcium carbonate, ground calcium carbonate, titanium oxides and synthetic resin fillers can be used in an amount of about 3-20% by weight of pulp in the base paper. These fillers can be used alone or as a combination of two or more of them for the purpose of controlling papermaking suitability of stock or strength characteristics.
[0016] These stock can be added to with chemicals commonly used during papermaking processes, such as paper strength enhancers, sizing agents, antifoaming agents, colorants, softening agents or the like as needed in the range not inhibiting the effects of the present invention.
[0017] The base paper may be prepared by any process for papermaking acidic, neutral or basic papers using a Fourdrinier paper machine including a top wire or the like, a cylinder paper machine, a combination machine of both or a Yankee dryer machine or the like and may also be a mechanical base paper containing recycled paper pulp obtained from old newspapers. Base papers precoated with starch or polyvinyl alcohol using a size press, bill blade, gate roll coater, premetering size press or the like may also be used. Base papers having a basis weight of about 30-400 g/m 2 used for normal coated papers can be used as coating base papers, but preferably about 30-100 g/m 2 because the present invention relates to coated printing papers, especially coated papers suitable for use in rotary newspaper presses. In the present invention, the base paper preferably has a density of 0.3 g/cm 3 or more and 0.8 g/cm 3 or less, more preferably a density of 0.3 g/cm 3 or more and 0.6 g/cm 3 or less.
[0018] In the present invention, the ability to decompose harmful substances in the atmosphere by exposure to light can be conferred by using a fine titanium dioxide as a pigment. It is preferably contained in an amount of 5 parts by weight or more, more preferably 10 parts by weight or more and 50 parts by weight or less per 100 parts by weight of the pigment. The titanium oxide in the present invention can be prepared from not only titanium oxides but also any titanium oxide or hydroxide called wet titanium oxides, hydrated titanium oxides, metatitanic acid, orthotitanic acid, and titanium hydroxide. The titanium oxide used in the present invention preferably has a primary particle size of 2-150 nm. It preferably has a specific surface area of 10-350 m 2 /g.
[0019] In the present invention, a mixture of a fine titanium dioxide and colloidal silica or alumina in a ratio of 5:1-1:5 is preferably used as a pigment in the coating color. Thus, coexisting organic adhesives can be inhibited from being decomposed. Preferably, a fine titanium oxide and a colloidal solution of silica or alumina are added in certain proportions, and after stirring for a given period, other pigments or additives are added.
[0020] In addition to the pigment as mentioned above, inorganic pigments such as precipitated calcium carbonate, ground calcium carbonate, clay, kaolin, engineered kaolin, delaminated clay, talc, calcium sulfate, titanium dioxide used for conventional papermaking, barium sulfate, zinc oxide, silicic acid, silicic acid salts, satin white; or organic pigments such as plastic pigments can also be used in the present invention. In the present invention, it is preferable to use calcium carbonate, especially ground calcium carbonate in terms of production costs and improvements in ink drying properties. Preferably, 30 parts by weight or more, more preferably 50 parts by weight or more of a mixture of calcium carbonate and titanium oxide is contained per 100 parts by weight of the pigment.
[0021] Adhesives used in the present invention can be selected as appropriate from one or more of conventional adhesives for coated papers, e.g., synthetic adhesives such as styrene-butadiene copolymers, styrene-acrylic copolymers, ethylene-vinyl acetate copolymers, butadiene-methyl methacrylate copolymers, vinyl acetate-butyl acrylate copolymers, or polyvinyl alcohols, maleic anhydride copolymers and acrylic-methyl methacrylate copolymers; proteins such as casein, soybean protein and synthetic proteins; starches such as oxidized starches, cationized starches, urea phosphate-esterified starches, hydroxyethyl etherified starches; and cellulose derivatives such as carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose. These adhesives are preferably used in a range of 5-50 parts by weight, more preferably 10-40 parts by weight per 100 parts by weight of the pigment. More than 50 parts by weight is not preferred because of disadvantage in runnability or the like, e.g., the resulting coatings becoming too viscous to readily pass through piping or screens. Less than 5 parts by weight is not preferred because of insufficient surface strength.
[0022] The coating color of the present invention may contain various conventional auxiliaries such as dispersants, thickeners, water-retention agents, antifoamers, water insolubilizers, dyes, optical brighting agents, etc.
[0023] The coating color prepared is applied in one or more layers on one or both sides of the base paper using a blade coater, bar coater, roll coater, air knife coater, reverse roll coater, curtain coater, size press coater, gate roll coater or the like. The range of the coat weight in which the present invention is effective is preferably 3 g/m 2 or more and 12 g/m 2 or less, more preferably 4 g/m 2 or more and 8 g/m 2 or less per side.
[0024] The wet coating layer is dried by using conventional means such as a steam heater, gas heater, infrared heater, electric heater, hot air dryer, microwave, cylinder dryer, for example.
[0025] After drying, the paper can be post-processed as needed to confer smoothness by carrying out finishing processes using a supercalender, a hot soft nip calender or the like. However, it can be processed by any calender or uncalendered so far as a coated paper of a desired quality can be obtained. Any other conventional paper processing means can also be applied.
EXAMPLES
[0026] The following examples specifically illustrate the present invention without, however, limiting the invention thereto as a matter of course. Unless otherwise specified, parts and % in the examples mean parts by weight and % by weight, respectively. Coating color and the obtained coated printing papers were tested by the following evaluation methods.
[0000] (Evaluation methods)
[0027] (1) Oil absorbency under pressure: The oil absorbency under pressure as defined herein was determined using AA-GWR Water Retention Meter from KALTEC. First, six pieces of each coated paper test sample (5 cm×5 cm) (or any number of pieces adjusted as appropriate if the sample is highly absorbent) and a piece of a membrane filter (from KALTEC; pore size 5.0 μm) are laid on the supplied rubber mat and the supplied cup is placed thereon, and the assembly is inserted into the instrument. The assembly is raised by the clamp to come into close contact with the top of the instrument, and then 1 ml of soybean oil (from Wako Pure Chemical Industries, Ltd., Wako first-class quality) is injected via the liquid inlet at the top, and immediately the supplied cap is put on the cup to start measurements. After maintaining the pressure in the cup at 50 kPa for 20 seconds, the cup was opened and the weight of the coated paper sample was measured. The area measured is 8 cm 2 . The weight gain corresponds to the weight of soybean oil absorbed by each paper under pressure and the weight of oil absorbed per m 2 was determined as oil absorbency under pressure herein.
[0028] Oil absorbency under pressure (g/m 2 )=(paper weight after measurement (g)-paper weight before measurement (g))/(0.0008 (m 2 ))
[0029] (2) Bekk smoothness: determined according to JIS P 8119.
[0030] (3) Ink receptivity: Printing was performed using an offset rotary press (4 colors) from Toshiba Machine Co., Ltd. with penetration drying type news inks for offset printing (Vantean Eco from Toyo Ink Mfg. Co., Ltd.) at a printing speed of 500 rpm, and the ink receptivity of the resulting print (solid print in three colors consisting of cyan, magenta and yellow) was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
[0031] (4) Ink drying properties: Immediately after printing using an RI press with a penetration drying type news ink for offset printing (Vantean Eco from Toyo Ink Mfg. Co., Ltd.), the resulting print (solid print in magenta simply) was transferred to a woodfree paper and the cleanness of the woodfree paper was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
[0032] (5) Print sharpness: Sharpness of the print in offset printing was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
[0033] (6) Stickiness: Stickiness of the print in offset printing was visually evaluated according to the 4-class scale: ⊚: very good, ◯: good, Δ: slightly poor, X: poor.
[0034] (7) Photocatalytic effect: A sheet was cut into 10 cm·15 cm and placed in a 5-liter quartz glass sealed vessel, and acetaldehyde gas was injected via a microsyringe to a concentration of 100 ppm in the vessel. The vessel was irradiated with UV rays using three 15-W black lights at a dose of 5.0 mW/cm 2 on the sheet surface. After 1 hr, the gas concentration in the vessel was measured by a Kitagawa gas detector tube to determine the decomposition rate (%), from which the photocatalytic effect was evaluated.
Example 1
[0035] In a Cellier mixer, 15 parts (solids) of a slurry of titanium oxide microparticles (CSB-M from Sakai Chemical Industry, Co., Ltd.) and 24 parts of colloidal silica (Snowtex 40 from Nissan Chemical Industries, Ltd.) were stirred for 1 hr. Into this mixed slurry was added a pigment slurry prepared by dispersing a pigment consisting of 40 parts of ground calcium carbonate (FMT-90 from Fimatec Ltd.) and 21 parts of fine clay (JapanGloss from HUBER) with a dispersant consisting of sodium polyacrylate (0.2 parts based on the inorganic pigment) in a Cellier mixer to prepare a pigment slurry having a solids content of 63%. To thus obtained pigment slurry were added 13 parts of a styrene/butadiene copolymer latex (glass transition temperature 20° C., gel content 85%) and 26 parts of a hydroxyethyl-etherified starch (PG295 from Penford Corporation) and water was further added to give a coating color having a solids content of 58%.
[0036] The base paper to be coated was a medium quality paper having a basis weight of 50 g/m 2 prepared from papermaking pulp consisting of 30% mechanical pulp and 70% chemical pulp and containing 7%, on the basis of the weight of the base paper, of light calcium carbonate as a filler and 0.3%, on the basis of the weight of the base paper, of an ester compound of a polyvalent alcohol and a fatty acid (KB-110 from Kao Corporation) as an organic compound having the effect of inhibiting interfiber binding of pulp.
[0037] The base paper was coated with the coating color on both sides at a coating mass of 5 g/m 2 per side using a blade coater at a coating speed of 700 m/min and dried to a moisture content of 5% in coated paper to give a coated printing paper.
Example 2
[0038] A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 10 parts (solids) of the slurry of titanium oxide microparticles, 16 parts of colloidal silica, 50 parts of ground calcium carbonate, and 24 parts of fine clay.
Example 3
[0039] A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 5 parts (solids) of the slurry of titanium oxide microparticles, 8 parts of colloidal silica, 60 parts of ground calcium carbonate, and 27 parts of fine clay.
Example 4
[0040] A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 10 parts (solids) of the slurry of titanium oxide microparticles, 16 parts of colloidal silica, and 74 of ground calcium carbonate.
Example 5
[0041] A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 10 parts (solids) of the slurry of titanium oxide microparticles, 66 parts of ground calcium carbonate, and 24 parts of fine clay.
Example 6
[0042] A coated printing paper was obtained by the same procedure as in Example 1 except that the ester compound of a polyvalent alcohol and a fatty acid (KB-110 from Kao Corporation) was not used as an organic compound having the effect of inhibiting interfiber binding of pulp in the base paper in Example 1.
Comparative Example 1
[0043] A coated printing paper was obtained by the same procedure as in Example 1 except that the coated paper was treated in a hot soft nip calender with 2 nips at a metal roll surface temperature of 100° C., a paper feed speed of 1200 m/min, and a linear load of 300 kN/m after it was dried in Example 1.
Comparative Example 2
[0044] A coated printing paper was obtained by the same procedure as in Example 6 except that the coated paper was treated in a hot soft nip calender with 2 nips at a metal roll surface temperature of 100° C., a paper feed speed of 1200 m/min, and a linear load of 300 kN/m after it was dried in Example 6.
Comparative Examples 3
[0045] A coated printing paper was obtained by the same procedure as in Example 1 except that the composition of the pigment slurry in Example 1 was changed to 70 parts of ground calcium carbonate and 30 parts of fine clay.
[0046] The evaluation results are shown in Table 1.
TABLE 1 Oil absorbency under Bekk Print pressure smoothness Ink Ink drying surface Photocatalytic (g/m 2 ) (sec) receptivity properties sharpness Stickiness effect (%) Example 1 56 31 ⊚ ⊚ ⊚ ⊚ 64 Example 2 70 33 ⊚ ⊚ ⊚ ⊚ 32 Example 3 74 35 ⊚ ⊚ ⊚ ⊚ 18 Example 4 90 25 ◯ ⊚ ⊚ ⊚ 30 Example 5 71 35 ⊚ ⊚ ⊚ ⊚ 29 Example 6 30 62 ⊚ ◯ ⊚ ◯ 65 Comparative 30 90 ⊚ X ⊚ Δ 65 example 1 Comparative 18 90 ⊚ X ⊚ X 65 example 2 Comparative 60 30 ⊚ ⊚ ⊚ ⊚ 0 example 3 | The present invention aims to provide coated printing papers having fast ink drying properties comparable to those of conventional newsprint, without stickiness, having good printability such as sharpness of printed images comparable to those of coated papers, as well as having the effect of decomposing harmful substances by exposure to light, especially when using penetration drying type news inks.
A coated printing paper is provided, comprising a coating layer containing a pigment and an adhesive on a base paper, characterized in that a fine titanium oxide powder having a photocatalytic effect is contained in the coating layer and that the coated paper has an oil absorbency of 20 g/m 2 or more under pressure and a Bekk smoothness of 75 seconds or less. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to new and useful improvements in peroxide compositions for use in resin polymerization and to methods of using such compositions.
2. Description of the Prior Art
In the foundry industry, sand is coated with resin binders and formed into molds and cores for the production of precision castings. A wide variety of techniques has been developed for the manufacture of sand cores and molds. These involve the hot box technique for mold and core formation; the shell method; the "No-Bake," and the cold-box technique.
In the hot box and shell methods, sand molds and cores are formed by heating a mixture of sand with a thermosetting resin at a temperature of about 300°-600° F. in contact with patterns which produce the desired shape for the mold or core. The resin is polymerized and a core or mold is formed. Procedures of this type are described in Dunn et al. U.S. Pat. No. 3,059,297 and Brown et al. U.S. Pat. No. 3,020,609.
A particular disadvantage of the hot box and shell methods is the necessity for heating the pattern boxes to 300°-600° F. to polymerize and cure the resin binder. This involves considerable expense and is generally a high cost technique.
The cold box technique for core and mold formation involve the use of sand mixed or coated with resins which may be cured at room temperature by acid or base catalysis. Acid or base catalysts have been used in liquid, solid or gaseous form. Typical cold box processes are shown in Blaies U.S. Pat. No. 3,008,205; Dunn et al. U.S. Pat. No. 3,059,297; Peters et al. U.S. Pat. No. 3,108,340; Kottke et al. U.S. Pat. No. 3,145,438; Brown et al. U.S. Pat. No. 3,184,814; Robins U.S. Pat. No. 3,639,654; Australian Pat. No. 453,160 and British Pat. No. 1,225,984. Many of these processes involve the use of sulfur-containing acid catalyst such as benzene sulfonic acid, toluene sulfonic acid and the like.
A few years ago, a process was developed for room temperature polymerization of condensation resin in which an acid-curing agent is generated in situ in the resin or on a sand-resin mix. It had previously been suggested in U.S. Pat. No. 3,145,438 to inject SO 3 in a form of a gas into a mixture of sand and resin to cure the resin at room temperature. It was found, however, that this process causes an instantaneous curing of the resin in the region subjected to treatment by SO 3 which impedes the diffusion of this gas to other parts of the resin, particularly the central parts of the mixture. Subsequently, a method was developed which avoided this difficulty. In Richard U.S. Pat. No. 3,879,339, it is disclosed that sand may be coated with a suitable oxidizing agent, such as an organic peroxide, and coated with the resin to be used in binding the sand into the form of a core or mold. The sand-resin mixture is then formed into suitable shape and treated with gaseous SO 2 . The SO 2 is oxidized, in situ, to SO 3 and converted to sulfur-containing acid by water present in the mixture. The sulfur-containing acid which is generated in situ causes a rapid and uniform polymerization of the resin at room temperature. This process has proved successful commercially and is applicable to phenolic resins, furan resins, and urea-formaldehyde resins, as well as mixtures and copolymers thereof.
In the cold box method of Richard U.S. Pat. No. 3,879,339, there are a large variety of peroxides disclosed which may be added to sand along with resins which are used in forming sand cores or molds. This composition is subsequently formed into shape and treated with gaseous SO 2 . The peroxides which are disclosed in the Richard patent are mostly quite expensive and, in many cases, are difficult to handle and to ship or transport. Organic peroxides require special approval for transportation in interstate commerce. Organic peroxides are often highly flammable or present other fire hazards. Organic peroxides also are often shock sensitive and may be explode or detonate under certain conditions. As a result, any and all organic peroxides can not be used in the Richard process because of economic and safety considerations.
SUMMARY OF THE INVENTION
One of the objects of this invention is to provide a new and improved storage stable, easily transportable, non-detonating organic peroxide composition for use as a catalyst component in the polymerization of resins.
Another object of this invention is to provide an improved organic peroxide composition including a solvent which is a cosolvent for the organic peroxide and hydrogen peroxide.
Another object of this invention is to provide an improved organic peroxide composition comprising a solution of 1,4-diisopropylbenzene monohydroperoxide or crude diisopropylbenzene hydroperoxide in a solvent, optionally including a small amount of hydrogen peroxide.
Another object of this invention is to provide an improved resin composition comprising a furfuryl alcohol-formaldehyde resin prepolymer having a minor amount of a peroxide composition containing 1,4-diisopropylbenzene monohydroperoxide, dissolved therein.
Another object of this invention is to provide an improved method of forming sand cores or molds wherein a major amount of sand is mixed with a minor amount of 1,4-diisopropylbenzene monohydroperoxide and a furfurylalcohol-formaldehyde prepolymer, forming the mixture into the shape of a core or mold and gasing the mixture with sulfurdioxide at a relatively low temperature.
Other objects of this invention will become apparent from time to time throughout the specification and claims as hereinafter related.
The above objectives are attained as described below. A peroxide system or composition for use in resin polymerization consists of 1,4-diisopropylbenzene monohydroperoxide dissolved in an organic solvent which is a solvent for hydrogen peroxide and 1,4-diisopropylbenzene dihydroperoxide. The peroxide composition is characterized by its storage stability, resistance to detonation, low flammability, ease of handling and improved catalytic properties in the polymerization of certain resins. The preferred peroxide, based on economic considerations, is a crude mixture, called crude diisopropylbenzene hydroperoxide, of a major amount of 1,4-diisopropylbenzene monohydroperoxide and a minor amount of 1,4-diisopropylbenzene dihydroperoxide, together with solvents and unreacted materials obtained as a byproduct in the commercial manufacture of p-diisopropylbenzene dihydroperoxide. A particularly stable and useful composition consists of about 20% solvent, preferably cyclohexanone, and 80% of a mixture consisting of a major part of crude diisopropylbenzene hydroperoxide and a minor part of hydrogen peroxide. This peroxide composition, and the 1,4-diisopropylbenzene monohydroperoxide, or the crude diisopropylbenzene hydroperoxide, are soluble in or miscible with furfuryl alcohol-formaldehyde resin prepolymers. The peroxide composition and the resin prepolymer are added to sand, formed into cores or molds, and gassed with sulfur dioxide at a temperature from room temperature to about 300° F. for a time from a few seconds to several minutes to form superior sand cores and molds.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention is directed to an improved peroxide composition which is particularly useful in the process of Richard U.S. Pat. No. 3,879,339. The peroxide composition consists of a solution or mixture of 1,4-diisopropylbenzene monohydroperoxide or a crude composition containing 1,4-diisopropylbenzene monohydroperoxide and 1,4-diisopropylbenzene dihydroperoxide, called crude diisopropylbenzene hydroperoxide, with a solvent which results in a stable system. It should be noted that, for the purposes of this invention, 1,4-diisopropylbenzene monohydroperoxide is effective but 1,4-diisopropylbenzene dihydroperoxide is less effective in the process of Richard U.S. Pat. No. 3,879,339. The presence of 1,4-diisopropylbenzene dihydroperoxide in admixture with 1,4-diisopropylbenzene monohydroperoxide is therefore as an undesired contaminant. The term "crude diisopropylbenzene hydroperoxide" is used hereinafter is intended to mean a composition substantially as defined above.
CRUDE DIISOPROPYLBENZENE HYDROPEROXIDE
In the commercial manufacture of p-diisopropylbenzene dihydroperoxide, an organic peroxide composition is obtained as a byproduct known in the trade as crude diisopropylbenzene hydroperoxide and consisting essentially of 1,4-diisopropylbenzene dihydroperoxide; 1,4-diisopropylbenzene monohydroperoxide; a-hydroxy,a-hydroperoxy diisopropyl benzene; a-hydroxy,diisopropyl benzene; and p-diisopropyl benzene.
One particular crude diisopropylbenzene hydroperoxide composition which was found to be useful had approximately the following composition:
______________________________________55.9% 1,4-diisopropylbenzene monohydroperoxide11.0% 1,4-diisopropylbenzene dihydroperoxide10.0% diisopropylbenzene 0.44% benzene 1.5% Water21% Mixture of 1-isopropyl-4-isopropanol benzene, 1,4-diisopropyl benzene, 1-isopropanol-4-isopropylben- zene hydroperoxide, and p-benzene dipropenoic acid disodium salt.______________________________________
The stated percentages, as used herein, are by weight based on total composition unless otherwise stated.
Solvents which are useable in preparing stable peroxide compositions in accordance with this invention are organic solvents which are cosolvents for 1,4-diisopropylbenzene monohydroperoxide, 1,4-diisopropylbenzene dihydroperoxide and hydrogen peroxide. Solvents which are particularly useful are methanol, cyclohexanone, glycol ethers (but not glycols), furfuryl alcohol, diisopropyl benzene (in compositions not containing hydrogen peroxide), dioxane and phenol. Such solvents will dissolve mixtures of 1,4-diisopropylbenzene monohydroperoxide and 1,4-diisopropylbenzene dihydroperoxide, such as crude diisopropylbenzene hydroperoxide and are cosolvents for hydrogen peroxide.
The proportions of organic peroxides and solvents in the following Examples are for purposes of illustration only. The peroxides may be mixed with any of the specified types of solvents at suitable proportions within the range of solubilities therein. Generally, the peroxides are present in an amount sufficient to provide a desired level of Active Oxygen in the composition, preferably about 6-8%. The composition may be prepared with or without the hydrogen peroxide but generally it is best to include the hydrogen peroxide. A level of about 80% of a mixture of crude diisopropylbenzene hydroperoxide and hydrogen peroxide in one of the specified solvents will produce the desired amount of Active Oxygen. If substantially pure 1,4-diisopropylbenzene monohydroperoxide is used in the composition, it will produce the desired amount of Active Oxygen at a much lower concentration therein. Likewise, increasing the amount of hydrogen peroxide may permit some decrease in the amount of the organic peroxide used. The concentration of hydrogen peroxide can not be increased very much without exceeding safety limits.
A series of peroxide solutions or compositions were prepared and tested for stability and safety and were subsequently tested in the polymerization of resins.
EXAMPLE I
A peroxide composition was prepared having the following composition:
______________________________________68% crude diisopropylbenzene hydroperoxide21% cyclohexanone11% 70% hydrogen peroxide______________________________________
It should be noted that the amount of solvent in this composition is somewhat critical. If the proportion of cyclohexanone is decreased below about 19% some of the ingredients begin to drop out of solution.
This composition was tested by the Association of American Railroads, Bureau of Explosives and was found to be satisfactory for safe transportation. A portion of the composition was maintained at 75° C. under a water reflux condensor for 48 hours. It did not ignite or undergo marked decomposition.
A portion of the sample contained in a plastic cup was initiated with a number 8 electric blasting cap, it did not explode or ignite. The same results were obtained when the same test was conducted using 120 ml. of the sample absorbed in eight grams of cotton.
A portion of the sample was placed on a kerosene-soaked sawdust bed and ignited with a burning fusee. When the fire reached the test portion, it burned only moderately.
One gallon of the sample contained in a one gallon metal can with a friction-sealed lid was heated on a kerosene/wood fire. The lid opened partially six minutes after the kerosene/wood was ignited. The material was ignited and burned with a black smoke for about five minutes. The flame height was about 40-50 feet.
The flash point of this sample was determined to be 174° F. using the SETA Closed-Cup Flash Point Tester.
In a burning test, the sample could be ignited with a match and burned with a maximum flame height of eighteen inches. In a pressure vessel test, the rupture disc failed to burst with the vent hole opening of one mm in diameter. In an impact test, the sample failed consistently to explode or ignite in the Bureau of Explosives Impact Apparatus under a drop height of ten inches when the sample was tested alone or absorbed in filter paper. In a Rapid Heat Test, the sample boiled at 105° C.-175° C., left about half of the sample behind. The color of the material turned darker as the temperature increased. The remained dark yellow material turned to a redish-orange color at 187° C., then turned to brown color at 310° C. No further reaction was observed up to 325° C. In a SADT Test, no exothermic reaction was observed for seven days with one gallon of the same sample contained in a plastic bottle was tested at 130° F. however, the color of the material turned brown.
Based the above test results, the Bureau of Explosives recommendation was that the composition to be described as 1,4-diisopropylbenzene monohydroperoxide solution, not over 60% and classed as Organic Peroxide under DOT regulations. This material is considered safe and transportable.
The peroxide composition of this example has an Active Oxygen content of about 7.8-8.0%. After storage at 130° F. for one week, Active Oxygen decreases by about 0.3%. This composition is stable for an indefinite period of time at temperatures near 0° F. This composition is usable in resin polymerization, as described below.
EXAMPLE II
A peroxide composition was prepared as follows:
______________________________________67.20% crude diisopropylbenzene hydroperoxide20.60% cyclohexanone 1.96% methenol10.24% 70% hydrogen peroxide______________________________________
This formulation is stable under the same conditions discussed in connection with Example I. The Active Oxygen content of this composition is about 7.8-8.0%. After storage at 130° F. for one week, Active Oxygen decreases by about 0.3%. This blend is stable for an indefinite period at temperatures near 0° F. This composition can be used in the polymerization of resins as described below.
EXAMPLE III
A peroxide composition was prepared as follows:
______________________________________69% crude diisopropylbenzene hydroperoxide10% cyclohexanone10% dipropyleneglycol11% 70% hydrogen peroxide______________________________________
This formulation is stable under the same conditions discussed in connection with Examples I and II. The Active Oxygen content of this composition is about 7.8-8.0%. After storage at 125° F. for 30 days, Active Oxygen decreases by about 0.4%. This blend is stable for an indefinite period at temperatures near 0° F. This composition can be used in the polymerization of resins as described below.
EXAMPLE IV
A peroxide composition is prepared as follows:
______________________________________40% 1,4-diisopropylbenzene monohydroperoxide50% cyclohexanone10% 70% hydrogen peroxide______________________________________
This formulation is stable under the same conditions discussed in connection with Examples I and II. The Active Oxygen content of this composition is about 5.8-6.0%. After storage at 130° F. for 7 days, Active Oxygen decreases by about 0.3%. This blend is stable for an indefinite period at temperatures near 0° F. This composition can be used in the polymerization of resins as described below.
EXAMPLE V
A peroxide composition is prepared as follows:
______________________________________50% 1,4-diisopropylbenzene monohydroperoxide50% diisopropylbenzene______________________________________
This formulation is stable under the same conditions discussed in connection with Examples I and II. The Active Oxygen content of this composition is somewhat lower than the other compositions, but it high enough to be effective. After storage at 130° F. for 7 days, Active Oxygen decreases by about 0.3%. This blend is stable for an indefinite period at temperatures near 0° F. This composition can be used in the polymerization of resins as described below.
EXAMPLE VI
Solubility of Peroxide Composition in Resin
It was found unexpectedly that the above peroxide compositions are soluble in and form stable mixtures with furfurylalcohol-formaldehyde resin prepolymers.
A solution of 35% crude diisopropylbenzene hydroperoxide and 65% furfurylalcohol-formaldehyde resin prepolymer was prepared and stored for six weeks at 105° F. At the end of this time, the blend showed no performance loss when polymerized to form sand cores or molds. A similar result is obtained when 1,4-diisopropylbenzene monohydroperoxide is blended with the resin prepolymer. In comparison, it had previously been found that methyl ethyl ketone peroxide was not stable when mixed with furfurylalcohol-formaldehyde resin prepolymer even at room temperature.
Use of Organic Peroxides in Resin Polymerization
The organic peroxide compositions described above are unexpectedly superior in stability and resistance to detonation which makes them easier to transport, store and use. These peroxide compositions are unexpectedly superior to methyl ethyl ketone peroxide (which has been the standard peroxide for resin polymerization by the SO 2 gassing process) for the polymerization of furfuryl alcohol-formaldehyde resin prepolymers by the SO 2 gassing process although they are not effective in the polymerization of phenolics by such a process.
EXAMPLE VII
A foundry-grade sand was mixed with 1.25% wt. (based on the sand) of a furfurylalcohol-formaldehyde resin prepolymer and mulled for three minutes. Next, 50-55% wt. (based on the resin weight) of the peroxide composition of EXAMPLE I was added and the mixture mulled for an additional three minutes. The sand/resin/peroxide mix was then rammed or blown into a mold and gassed with SO 2 for about 1.0 seconds at room temperature, followed by an air purge. Gassing times of about 0.5 seconds to about 5 minutes and temperatures from room temperature to about 300° F. can be used. The product obtained after 20 seconds, as described above, is capable of being handled immediately. This product has better hardness than a like product made using methyl ethyl ketone peroxide. Core strengths of 200 after 30 minutes and 273 after 24 hours are substantially higher than are obtained using methyl ethyl ketone peroxide, viz, 185 after 30 minutes and 218 after 24 hours, respectively.
EXAMPLE VIII
A different foundry-grade sand was mixed with 1.25% wt. (based on the sand) of a furfurylalcohol-formaldehyde resin prepolymer and mulled for three minutes. Next, 50-55% wt. (based on the resin weight) of the peroxide composition of EXAMPLE II was added and the mixture mulled for an additional three minutes. The sand/resin/peroxide mix was then rammed or blown into a mold and gassed with SO 2 for about 1.0 seconds at room temperature, followed by an air purge. Gassing times of about 0.5 seconds to about 5 minutes and temperatures from room temperature to about 300° F. can be used. The product obtained after 20 seconds, as described above, is capable of being handled immediately. This product has better hardness than a like product made using methyl ethyl ketone peroxide. Core strength 444 after 24 hours was substantially higher than is obtained using methyl ethyl ketone peroxide, viz, 386 after 24 hours.
EXAMPLE IX
A foundry-grade sand was mixed with 1.25% wt. (based on the sand) of a furfurylalcohol-formaldehyde resin prepolymer and mulled for three minutes. Next, 50-55% wt. (based on the resin weight) of the peroxide composition of EXAMPLE III was added and the mixture mulled for an additional three minutes. The sand/resin/peroxide mix was then rammed or blown into a mold and gassed with SO 2 for about 1.0 seconds at room temperature, followed by an air purge. Gassing times of about 0.5 seconds to about 5 minutes and temperatures from room temperature to about 300° F. can be used. The product obtained after 20 seconds, as described above, is capable of being handled immediately. This product has better hardness than a like product made using methyl ethyl ketone peroxide. Core strengths of 210 after 30 minutes and 338 after 24 hours are substantially higher than are obtained using methyl ethyl ketone peroxide, viz, 185 after 30 minutes and 218 after 24 hours, respectively.
EXAMPLE X
A foundry-grade sand was mixed with 1.25% wt. (based on the sand) of a furfurylalcohol-formaldehyde resin prepolymer and mulled for three minutes. Next, 50-55% wt. (based on the resin weight) of the peroxide composition of EXAMPLE VI was added and the mixture mulled for an additional three minutes. The sand/resin/peroxide mix was then rammed or blown into a mold and gassed with SO 2 for about 1.0 seconds at room temperature, followed by an air purge. Gassing times of about 0.5 seconds to about 5 minutes and temperatures from room temperature to about 300° F. can be used. The product obtained after 20 seconds, as described above, is capable of being handled immediately. This product has better hardness than a like product made using methyl ethyl ketone peroxide. Core strengths after 30 minutes and after 24 hours are substantially higher than are obtained using methyl ethyl ketone peroxide.
Similar results are obtained when the peroxide composition of EXAMPLE IV is used in the same test procedure.
EXAMPLE XI
A foundry-grade sand was mixed with 1.9% wt. (based on the sand) of a furfurylalcohol-formaldehyde resin prepolymer-peroxide blend of the composition of EXAMPLE VII and mulled for three minutes. Next, 10% wt. (based on the resin weight) of 50% hydrogen peroxide was added and the mixture mulled for an additional three minutes. The sand/resin/peroxide mix was then rammed or blown into a mold and gassed with SO 2 for about 1.0 seconds at room temperature, followed by an air purge. Gassing times of about 0.5 seconds to about 5 minutes and temperatures from room temperature to about 300° F. can be used. The product obtained after 20 seconds, as described above, is capable of being handled immediately. This product has better hardness than a like product made using methyl ethyl ketone peroxide added separately (the mixture is not stable). The core strength of 254 after 30 minutes is substantially higher than is obtained using methyl ethyl ketone peroxide added separately, viz, 185 after 30 minutes.
This procedure was repeated under a number of different conditions and in some cases satisfactory results are obtained using the resin-peroxide blend without the addition of hydrogen peroxide to the composition.
While this invention has been described fully and completely with emphasis upon several preferred embodiments, it should be understood that, within the scope of the appended claims, this invention may be practiced otherwise than as specifically described herein. | A peroxide system or composition for use in resin polymerization consists of 1,4-diisopropylbenzene monohydroperoxide dissolved in an organic solvent which is a solvent for hydrogen peroxide and 1,4-diisopropylbenzene dihydroperoxide. The peroxide composition is characterized by its storage stability, resistance to detonation, low flammability, ease of handling and improved catalytic properties in the polymerization of certain resins. The preferred peroxide, based on economic considerations, is a crude diisopropylbenzene hydroperoxide mixture comprising a major amount of 1,4-diisopropylbenzene monohydroperoxide and a minor amount of 1,4-diisopropylbenzene dihydroperoxide, together with solvents and unreacted materials obtained as a byproduct in the commercial manufacture of p-diisopropylbenzene dihydroperoxide. A particularly stable and useful composition consists of about 20% solvent, preferably cyclohexanone, and 80% of a mixture consisting of a major part of crude diisopropylbenzene hydroperoxide and a minor part of hydrogen peroxide. This peroxide composition, and the 1,4-diisopropylbenzene monohydroperoxide, or the crude diisopropylbenzene hydroperoxide, are soluble in or miscible with furfuryl alcohol-formaldehyde resin prepolymers. The peroxide composition and the resin prepolymer are added to sand, formed into cores or molds, and gassed with sulfur dioxide, and optionally purged with air, at a temperature from room temperature to about 300° F. for a time a fraction of a second to several minutes to form superior sand cores and molds. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to data communications, and more particularly, to data communications in which multiple service classes are supported.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The Internet is a collection of interconnected networks, all of which use the Internet Protocol (IP). The connections between these networks can be used to support a wide range of applications including, for example, electronic mail, file transfer, electronic commerce, downloading of web site information, and voice over IP. Different types of IP services may require different qualities of service. Quality of service (QoS) is the level of assurance that the network can meet a particular application's service requirements. From a technical perspective, quality of service can be characterized by several performance criteria such as availability, throughput, setup time, percentage of successful transmissions, etc., and can be measured in terms of bandwidth, packet loss, delay, and jitter. In an IP header, one of the fields typically corresponds to a traffic class, which enables different types/classes of traffic to be differentiated from others. A higher level traffic class corresponding to a higher quality of service may be given a higher priority than a lower level traffic class with a lower QoS. For example, real-time applications such as voice might be given a higher priority than other non-real-time applications such as e-mail.
[0003] In IP networks that support multiple quality of service classes, there may be situations when one traffic class with stricter delay requirements is multiplexed with another traffic class with less strict delay requirements. For example, voice traffic has strict delay requirements while certain types of data traffic typically has less strict delay requirements. In such a situation, even though the voice traffic has priority over the data traffic, the delay of voice packets is nonetheless influenced by the size of the data packets. At the start of transmission of a large data packet, a voice packet cannot be sent until transmission of that large data packet is finished. For example, if the size of the data packet is one kilobyte and the transmission rate is 64 kbps, the next voice packet to be transmitted in the multiplexed transmission may be delayed by as much as 125 milliseconds.
[0004] Accordingly, the way in which IP packets are sized or the way in which IP packets are fragmented/segmented for transmission may affect delay and other service parameters. One example algorithm for fragmenting packets is the point-to-point protocol (PPP) multilink protocol (MP) described in an IETF RFC written in 1990 by K. Sklower et al. entitled, “The PPP Multilik Protocol W).” The RFC indicates that systems implementing the multilink procedure are not required to segment packets, although segmentation may be performed. Segmenting longer, lower priority data packets may prevent transmission delays of a voice packet on a multiplexed transmission link. However, no segmenting algorithm is described in the RFC.
[0005] One simple approach to segmenting data packets for multilink procedures, (as well as for other procedures), is to divide the packet into segments of equal size, with all of the segments having the maximum segmentation size possible. More than likely, some portion of the packet smaller than the maximum segmentation size will make up the last packet segment. Unfortunately, this relatively simple segmentation procedure does not take into account how it impacts transmission delays for both the voice and data.
[0006] Consider the example in FIG. 1 which shows the output of a voice buffer or queue when there is no data traffic to be transmitted over a multiplexed link A first voice burst includes four packets separated by a very brief idle period from a second voice burst that contains five voice packets. A considerably longer idle period separates the second and third voice bursts, the third voice burst having five data packets, etc. FIG. 2 illustrates a situation where data traffic is interspersed in the transmission with the voice traffic. The timing of transmission of the original voice burst when there is no data traffic is illustrated in dotted blocks for comparison to the multiplexed transmission. The data packet is segmented into four segments, with segments 1 , 2 , and 3 having the same segment size, and the last segment 4 having a much smaller size.
[0007] As can be seen in FIG. 2A, the five packets in the second voice burst are uniformly delayed by the time it takes to transmit the first data packet segment minus the duration of the first idle period. If the idle period were longer, the delay in transmitting the voice packets in the second burst would be shorter. Segment 1 of the data packet could have increased the delay of the corresponding burst by a value uniformly distributed between 0 and the segment size. This is the case for all other segments. In other words, large data segments are more likely to cause longer voice delays.
[0008] To better understand how segmentation affects the delay of the segmented packet, examine two other segmentation options. FIG. 2B shows a situation where the size of Segment 3 is increased and the size of Segment 2 is decreased by the same amount of bytes. Although the delay of the third voice burst is reduced, the overall delay of the data packet remains the same. FIG. 2C shows that when the size of the last segment is increased, the delay of the data packet decreases. Thus, the delay of the last segment corresponds to the delay of the complete packet and depends on the size of the last segment, assuming the packet size does not change. Accordingly, in to achieve lower delay for the data packet, the last segment should be as large as possible. For lower voice delay, the largest data packet segments should be as small as possible.
[0009] [0009]FIG. 3 shows a graph where the size of the last segment and the size of the largest segment for a 1013-byte data packet is plotted as a function of maximum segmentation size in the case where a maximum segmentation algorithm is used. Using this maximum segmentation algorithm is not optimal because the last segment ends up being smaller than the maximum size. Indeed, in some situations, the last segment is very small which corresponds to a longer, “worst case” delay of data packets.
[0010] More formally, if the size of the last segment is denoted by L, the packet size by P, and the bit rate of the multiplexed link by C, the time needed to transmit the last data packet segment is L/C. The time needed for transmission of the data packet is (T 1 +T 2 ), where T 1 is the time when the sum of idle times between voice bursts is equal to (P−L)/C, and T 2 =L/C. Therefore, the delay of the data packet is minimal if the size of last segment is maximized.
[0011] Based on these recognitions, two general rules are employed to characterize how the segmentation size of data packets influences delays in the voice/data multiplex transmission. First, a worst case delay increase of higher priority voice packets is reduced when the size of the largest data segment is reduced. Second, the delay of low priority data packets is reduced when the size of the last data segment, (not the size of the largest segment), is increased relative to the size of the other segments of the data packet.
[0012] The efficiency of transmitting lower priority data traffic along with higher priority traffic is improved by segmenting a data packet in such a way so as to reduce transmission delay of the higher priority traffic. The data packet is segmented so that all its segments, including the last segment, are approximately the same size. The segment size is set smaller than a maximum permitted segment size. However, there may be reasons not to set that size too small. For example, because each includes a protocol header, the total “overhead” of the data packet transmission is proportional to the number of segments. To reduce such overhead, the number of segments should preferably be kept to the minimum number allowed by the maximum permitted segment size. Thus, it is desirable (though not necessary) to set the segment size as small as design parameters allow in order to reduce transmission delay of the higher priority traffic but at the same time not increase overhead associated with segment headers. Because the last segment is set at the same size or a larger size than the other segments, delay in transmitting the data packet is also reduced. The last segment may be sized as large as practical to minimize the transmission delay of the data packet. Once segmented, the data packet segments are transmitted along with the higher priority traffic.
[0013] One example, non-limiting implementation employs a relatively simple algorithm. Initially, an overall size of the data packet to be transmitted is determined. First and second segment sizes are determined for the data packet. The first and second segment sizes are determined to reduce the delay in transmitting the higher priority traffic, transmitting the data packet, or both. The data packet is segmented into plural segments at the first segment size and a last segment at the second segment size. The higher priority traffic is multiplexed along with the data packet segments. The first segment size is smaller than the maximum allowed segment size, and all of the data packet segments except the last segment are the same first segment size. Although the last segment may be the same size as the first segment size, the second segment size is preferably larger than the first segment size.
[0014] The examples above, described with two priority levels of traffic, may be applied to multiplexed transmissions with three or more traffic priority levels. Two detailed, non-limiting, examples of how to implement the basic segmenting algorithm are described below. In general, the first example emphasizes delay reduction for higher priority traffic, while the second example emphasizes delay reduction for the lower priority data packet segments. However, both the first and second segmentation examples achieve delay reductions for both the high priority and data packet traffic.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing and other objects, features, and advantages of the present invention may be more readily understood with reference to the following description taken in conjunction with the accompanying drawings.
[0016] [0016]FIG. 1 illustrates the output of the voice queue in FIG. 1 when data packet traffic is not present in the data queue;
[0017] FIGS. 2 A- 2 C illustrate the output of the scheduler 20 in FIG. 1 when data traffic is multiplexed with the voice for different packet segment sizes;
[0018] [0018]FIG. 3 is a graph illustrating segment size versus maximum segmentation size for both the last segment and the largest/maximal segment in a segmentation approach where the maximum segmentation size is employed;
[0019] [0019]FIG. 4 is a simplified block diagram of a communications system where bursts and data packets are multiplexed over a transmission channel and in which the present invention may be employed;
[0020] [0020]FIG. 5 illustrates an Optimized Segmentation routine in accordance with an example embodiment of the present invention;
[0021] [0021]FIG. 6 illustrates details of one example segmentation algorithm;
[0022] [0022]FIG. 7 is a flowchart illustrating details of a second example segmentation algorithm;
[0023] [0023]FIG. 8 is a graph illustrating segment sizes of last and maximal segments for segmentation algorithms;
[0024] [0024]FIG. 9 illustrates an example apparatus for implementing a segmentation algorithm;
[0025] [0025]FIG. 10 is a graph illustrating voice delay as a function of a maximum segmentation size; and
[0026] [0026]FIG. 11 is a graph illustrating data delay as a function of maximum segment size.
DETAILED DESCRIPTION
[0027] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular embodiments, procedures, techniques, etc. in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. For example, while the example embodiment described below relates to voice traffic and low priority data traffic, the present invention may be applied to any types of traffic in a communications system that offers communication services with different qualities of service, priorities, etc.
[0028] In some instances, detailed descriptions of well-known methods, interfaces, devices, and signaling techniques are omitted so as not to obscure the description of the present invention with unnecessary detail. Moreover, individual function blocks are shown in some of the figures. Those skilled in the art will appreciate that the functions may be implemented using individual hardware circuits, using software functioning in conjunction with a suitably programmed digital microprocessor or general purpose computer, using an application specific integrated circuit (ASIC), and/or using one or more digital signal processors (DSPs).
[0029] The present invention may be employed in any communications system where different classes/types/priorities of traffic are multiplexed onto or otherwise share a transmission channel. Consider the simplified, example communications system 10 shown in FIG. 4 that includes a transmit side 12 which sends packet information over a channel to a receive side 14 . The transmit side 12 includes a voice queue 16 for storing higher priority voice bursts/packets and a data queue 18 for storing lower priority data packets. A scheduler 20 receives the higher priority voice bursts as well as the lower priority data packets and employs a segmenter 22 for segmenting data packets received from the data queue 18 before multiplexing data packet segments received from the segmenter 22 with the voice bursts before transmission over the channel. The receive side includes a demultiplexer and reassembler 24 which extracts the voice packets and directs them to a voice output as well as reassembles the packets segments into a data packet and directs that reassembled data packet to a data output.
[0030] Optimal segmentation is determined for a data packet of a lower priority or traffic class when information from a higher priority class is transmitted along with segments of the lower priority data packet. Such segmentation may also be employed when there are three or more different traffic classes/priority levels QoS's. However, for simplicity, and not for limitation, the following description employs the example of two traffic classes characterized as higher priority traffic, e.g., voice, and lower priority traffic, e.g., data.
[0031] Although various optimal segmentation algorithms with specific procedures are described below, the present invention is not limited to the details of a particular segmentation algorithm. Rather, the present invention follows two guidelines. First, to reduce delay of a higher priority traffic class, the largest packet size of the lower priority data packet should be reduced. Ideally, the largest packet size should be reduced as small as possible. However, in practice, this goal may be limited to ensure that the number of segments is not unduly increased. As explained above, if the number of segments is larger then needed, the overhead for the packet increases because a segment header is needed for each segment. Thus, it is preferred (but not necessary) that the packet be segmented into as few segments as the maximum segment size allows while minimizing the size of each of those segments in that minimum number. Second, the delay of the lower priority traffic is reduced when the size of the last data segment is increased. Ideally, the last data segment size should be increased as large as possible or practical within design constraints. Thus, both high priority and low priority traffic delays may be reduced if the last segment size is larger than the other segments, and the other segments have approximately the same relatively small size. If the number of segments is determined as the smallest value allowed by the maximum allowed segment size, the largest segment is as small as possible when all of the segments are of equal size.
[0032] Referring now to one example procedure entitled Optimize Segmentation (block 30 ) shown in FIG. 5, the overall size of the lower traffic class packet to be transmitted is determined (block 32 ). One or more segment sizes is then determined to reduce the delay of the higher priority traffic and/or the lower priority traffic (block 34 ). These first two steps define the basic optimized segmentation methodology in accordance with a general example embodiment of the present invention. However, additional steps are shown in FIG. 5 that may be desirably performed. For example, in block 36 , the same segment size is selected for most segments of the data packet from the lower traffic class, with that segment size being preferably as small as practical within other system design constraints. In addition, a larger segment size is selected for the last segment to reduce the delay of the lower priority traffic data packet. The packet is segmented accordingly, and the segments are transmitted with the higher priority traffic packets in multiplexed fashion (e.g., similar to the example shown in FIG. 2) over a communications channel (block 36 ). One example multiplex communication environment is that described above for networks that support multiple service classes and employ the PPP multilink protocol. However, any protocol that segments packets may be used, such as segmentation at the IP level.
[0033] Using the procedures described above, the traffic delay associated with a system that carries two or more traffic classes is decreased both for the higher and lower priority traffic. Furthermore, this reduced traffic delay is easy to implement using a variety of relatively simple segmentation algorithms, two examples of which are described below.
[0034] Any segmentation algorithm that follows the guidelines set forth above may be employed. A first example, non-limiting segmentation algorithm is now described that segments the data packet into equal size segments. A predetermined segment size parameter, e.g., a maximum segment size (MSS) defined for the lower priority traffic class, is used to calculate a number of segments “n.” More formally, the number of segments
n = ceil [ P MSS ] ,
[0035] where ceil[ ] denotes rounding to the next larger integer if
P MSS
[0036] results in an integer plus a remainder. A number of “large” segments n 1 =mod(P, n), where mod denotes the remainder of the division
P n .
[0037] A number of “small” segments n 2 =n−n 1 . The size of one or more large segments
S 1 = ceil [ P n ]
[0038] and the size of the small segments
S 2 = floor [ P n ] ,
[0039] where floor denotes rounding to the next smaller integer if
P n
[0040] results in an integer and a remainder. The first n 2 segment is small, and the remaining n 2 segments are large. The difference between large and small segments is one byte. It may be desirable in some situations to set the first segment size to a size larger than the maximum segment size that will be applied on a packet. In this case, two different maximum segment sizes will be used. The first segment will be set to a predetermined value, and a segmentation algorithm is applied to the rest of the packet.
[0041] [0041]FIG. 6 illustrates a “Segment 1” routine (block 40 ) illustrated in flowchart format in accordance with the first segmentation algorithm. The size of the packet P is determined (block 42 ). The number of segments n is determined for the lower priority packet in accordance with
n = ceil [ P MSS ] ,
[0042] where MSS is the maximum segment size set to reduce high priority traffic delay (block 44 ). A number of larger segments n, =mod(P, n) and a number of smaller segments n 2 =n−n 1 are calculated (block 45 ). Segment sizes Sand S 2 are determined in accordance with the equations:
S 1 = ceil [ P n ]
[0043] for large segment(s) and
S 2 = floor [ P n ]
[0044] for small segment(s) (block 46 ). The data packet is segmented using the segment sizes S 1 and S 2 (block 48 ). The first n 1 packet segments are set to size S 1 . The last n 2 segments are set to size S 2 .
[0045] A second example, non-limiting segmentation algorithm is described in a “Segment 2” routine (block 50 ) shown in flowchart form in FIG. 7. Again, the size of the packet P is determined (block 52 ). The number of segments n is determined for the packet in accordance with
n = ceil [ P MSS ] ,
[0046] where MSS is the maximum segment size set to reduce high priority traffic delay (block 54 ). The size of the segment S(i) is determined in accordance with the following
S ( i ) = { if 1 ≤ i ≤ n - 2 then ceil [ P - MSS n - 1 ] if i = n - 1 then P - ( n - 2 ) · ceil [ P - MSS n - 1 ] if i = n then MSS
[0047] (block 56 ). The data packet is segmented using the size relationships for S(i) set forth in block 56 (block 58 ).
[0048] [0048]FIG. 8 is a graph that shows the size of the last and largest segment for both algorithms, Segment 1 and Segment 2 , depending upon the maximum segmentation size. Because the last segment is the largest one in both cases, minimal delays are incurred for both algorithms. The curve for the Segment 1 algorithm is below the curve of the Segment 2 algorithm. In other words, the largest and last segment size is smaller when using the Segment 1 algorithm as compared to the Segment 2 algorithm. Therefore, it can be expected that the Segment 1 algorithm outperforms the Segment 2 algorithm regarding voice delay. Regarding data delay, the Segment 2 algorithm outperforms the Segment 1 algorithm.
[0049] The present invention may be employed in any data transmitter. A simplified transmission apparatus 60 is shown in FIG. 9 for implementing the present invention. Multiple priority levels/traffic classes are shown 1 , 2 , 3 , . . . X. Priority 1 traffic is shown directly input to a packet scheduler 62 . Other lower priority level traffic classes input their packets into a respective segmenter 64 which segments the packet in accordance with a segmentation algorithm and stores the segments in a buffer 66 . The output of the segment buffer 66 is provided to the scheduler 62 . The scheduler 62 multiplexes the priority 1 traffic packets with packet segments from one or more of the other lower priority level traffic inputs and sends the combined information out on a physical channel/link, using an appropriate protocol.
[0050] Each segmenter 64 , as shown for the priority x traffic, has its own maximum segment size MSS which can be used, for example, in either of the above-described, example segmentation algorithms to determine optimal segment sizes. While a single segmentation algorithm may be employed, it may be desirable in certain situations to have plural segmentation algorithms available and to select one. As will be described below, one segmentation algorithm may be more optimal for minimizing, delays of a higher priority traffic class, while the other algorithm is more optimal for mining delay of a lower priority traffic class. The segmenter 64 also may add a fragmentation protocol header, e.g., PPP/multiprotocol (MP) header, to each segment before sending the segment to the buffer if an PPP/MP protocol is used. These headers permit reconstruction of the data packet from received segments at the receive side.
[0051] To illustrate how the example first and second segment algorithms reduce delays when two different traffic classes are carried over the same link, a simulation was conducted for a low priority class with large packets that need to be segmented and a high priority voice class with potentially short voice packets. The simulation was based on a 1920 kbps link (E 1 ) that carries multiplexed voice-data traffic. Each high priority voice source transmits 144-byte packet every 20 milliseconds, and each low priority data source transmits 1013-byte packet every 20 milliseconds. The traffic mix includes the traffic of one data source and 80 voice sources. Overhead introduced by segmentation was neglected during the simulations because it does not influence the comparison.
[0052] [0052]FIG. 10 shows for the simulation voice packet delay as a function of maximum segmentation size, and FIG. 11 shows data packet delay as a function of maximum segment size. From FIG. 10, it can be seen that voice packet delay as a function of maximum segmentation size is the best when segment algorithm 1 is applied. However, segment algorithm 2 still performed better than simply segmenting a data packet using the maximum segment size (MSS). In FIG. 11, it is apparent that the data delay is reduced the most if segment algorithm 2 is used. However, segment algorithm 1 is still better than the MSS method described in the background. Moreover, neither segmentation algorithm adds any additional complexity as compared to the MSS segmentation algorithm.
[0053] While the present invention has been described with respect to particular embodiments, those skilled in the art will recognize that the present invention is not limited to these specific exemplary embodiments. Different formats, embodiments, and adaptations besides those shown and described as well as many variations, modifications, and equivalent arrangements may also be used to implement the invention. Therefore, while the present invention has been described in relation to its preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention. Accordingly, it is intended that the invention be limited only by the scope of the claims appended hereto. | The efficiency of transmitting lower priority data traffic along with higher priority traffic is improved by segmenting a data packet in such a way so as to reduce transmission delay of the higher priority traffic. The data packet is segmented so that all its segments, including the last segment, are approximately the same size. The segment size is set smaller than a maximum permitted segment size. Indeed, it is desirable (though not necessary) to set the segment size as small as design parameters, (e.g., minimize segment header overhead), allow in order to reduce transmission delay of the higher priority traffic. Because the last segment is set at the same size or a larger size than the other segments, delay in transmitting the data packet is also reduced. The last segment may be sized as large as practical to minimize the transmission delay of the data packet. Once segmented, the data packet segments are transmitted along with the higher priority traffic. | 7 |
FIELD OF THE INVENTION
The present invention relates to a method for fabricating a pattern in a semiconductor device; and, more particularly, to a method for fabricating a conducting layer pattern using a hard mask of which an upper surface is flattened by the use of an ArF exposure light source.
DESCRIPTION OF THE PRIOR ART
With the integration of semiconductor devices, the distance between patterns is getting smaller and the height of a photoresist layer, as an etching mask, is also getting lower. As the thickness of photoresist layer becomes thinner, the photoresist layer dose not perfectly function as an etching mask to etch an oxide layer or other layers in forming a high aspect ratio contact hole or a self-aligned contact hole. Therefore, a high quality hard mask has been required to guarantees a high selective etching process with a high aspect ratio.
Various layers, such as a nitride layer and a polysilicon layer, have been used as hard masks and a processing margin must be used in a selective etching process of a photoresist layer which uses hard masks. Further, by minimizing a loss of critical dimension (hereinafter, referred to as a “CD”), CD bias (difference between the photoresist pattern and an actually formed pattern) is reduced.
However, when a nitride hard mask is used, with the decrease of the design rule, the thickness of the nitride layer is decreased. In order to obtain a high selective etching ratio for the nitride layer in an oxide layer etching process, a large amount of polymer generating gas is used at the time a contact hole is formed. This large amount of polymer causes a reappearance problem and a reduced contact area. The reduced contact area is caused by a slope etching profile which results in a metal connection having a high resistance in the contact hole.
On the other hand, this problem caused by the polymer generating gas can be overcome, but it is very difficult to obtain a high selective etching ratio for a silicon material including a semiconductor substrate when the polysilicon layer is removed. Particularly, using a photoresist layer to form fine patterns using an ArF exposure light source, an adhesion problem is also caused and further polysilicon hard mask patterning itself becomes difficult. In a bit line and a word line, the depth of the etching target increases with the increase of a vertical thickness of these lines. Also, in order to form the bit line and word line, a noble metal having high etching barrier characteristics is used as a hard mask. A dual hard mask consisting of a nitride and the noble metal is also used.
FIGS. 1A to 1C are cross-sectional views illustrating a conventional method for forming a conducting layer in a semiconductor device.
First, referring to FIG. 1A , a conducting layer 10 to be etched is formed on a semiconductor substrate (not shown) on which different elements have been formed. A nitride layer 11 for a first hard mask and a tungsten layer 12 for a second hard mask are in order formed on the conducting layer 10 . In order to prevent random reflection in the photolithography process and to improve adhesive strength to the lower layer for an ArF photoresist layer, an antireflective coating layer 13 is formed on the tungsten layer 12 and a photoresist layer 14 for forming a pattern (gate electrode) is formed on the antireflective coating layer 13 . The conducting layer 10 is a stacked layer of a polysilicon layer and a tungsten layer and the antireflective coating layer 13 is an organic layer.
Referring to FIG. 1B , the antireflective coating layer 13 and the tungsten layer 12 for the second hard mask are in order etched using the photoresist layer 14 as an etching mask, thereby forming an antireflective coating pattern 13 ′ and a second hard mask pattern 12 ′ with the formation of the photoresist pattern 14 ′.
Subsequently, referring to FIG. 1C , a first hard mask pattern 11 ′ is formed using the photoresist pattern 14 ′, the antireflective coating pattern 13 ′ and the second hard mask pattern 12 ′ as an etching mask, thereby forming a staked hard mask pattern consisting of the first and second hard mask patterns.
As shown in FIG. 1C , a spire-shaped hard mask pattern 12 ″ is formed on the second hard mask pattern 12 ′ when the first hard mask pattern 11 ′ is formed and this is caused by a tapered etching process of the second hard mask pattern 12 ′.
FIG. 2 is a photograph taken by a SEM showing such a spire-shaped top portion formed on the second hard mask pattern 12 ′ and FIG. 3 is a photograph taken by a SEM showing a conducting layer pattern formed by etching the conducting layer.
The spire-shaped hard mask pattern 12 ″ is shown in FIG. 2 . Referring to FIG. 3 , the first hard mask pattern 11 ′ also has a spire-shaped top portion to form a spire-shaped hard mask pattern 11 ″ because the first hard mask pattern 11 ′ is etched by using the spire-shaped hard mask pattern 12 ″ as an etching mask.
FIG. 4 is a photograph taken by a TEM showing a conducting layer pattern having a stacked structure of the tungsten layer and the polysilicon layer. The conducting layer pattern 10 ′ is formed by stacking a polysilicon layer pattern 10 b and a tungsten layer pattern 10 a and the spire-shaped hard mask pattern 11 ″ is formed on the conducting layer pattern 10 ′ because the spire-shaped hard mask pattern 12 ″ is projected to the first hard mask pattern 11 ′.
As stated above, the spire shape of the hard mask causes some problems as follows:
1) This causes a difference in thickness of the first hard mask of a nitride layer between a cell area and a peripheral area. This means a thickness difference of the first hard mask according to the size of the conducting layer. For example, the more the line size of the conducting layer increases, the more the thickness of the first hard mask increases. In a 100 nm line techniques, the first hard mask may have a difference of 400 Å–500 Å in thickness between a cell area and a peripheral area.
2) When depositing a plug material to form a plug between conducting layer patterns and performing planarization and isolation processes, it is very difficult to control the thickness of the first hard mask because the polishing rate dramatically increases at the spire-shaped portion. This may cause SAC defects to make the semiconductor device fail.
3) In the line techniques not exceeding 70 nm design rule, the spire-shaped portion may increase device failure.
Accordingly, it is necessary to develop an improved process to prevent the spire or round-shaped portion of the hard mask from being generated in etching and patterning processes.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method for fabricating a conducting layer pattern in which a tapered etching of a hard mask for patterning a conducting layer is prevented.
Another object of the present invention is to provide an improved method for forming an etching mask having no spire or round-shaped portion at the top of etching mask patterns.
In accordance with an aspect of the present invention, there is provided a method for fabricating a semiconductor device using an ArF exposure light source comprising the steps of: forming a conducting layer on a semiconductor substrate; forming a first hard mask layer, a second hard mask layer and a third hard mask layer on the conducting layer in order; forming a photoresist pattern on the third hard mask layer using an ArF exposure light source in order to form a predetermined pattern; forming a first hard mask pattern by etching the third hard mask layer using the photoresist pattern as an etching mask; forming a second hard mask pattern by etching the second hard mask layer using the first hard mask pattern as an etching mask; removing the first hard mask pattern; and etching the first hard mask layer and the conducting layer using the second hard mask pattern as an etching mask and forming a stacked hard mask pattern having the conducting layer and the second and first hard mask patterns.
In accordance with another aspect of the present invention, there is provided a method for fabricating a semiconductor device using an ArF exposure light source comprising the steps of: forming a conducting layer on a semiconductor substrate; forming a first hard mask layer, a second hard mask layer and a third hard mask layer on the conducting layer in order; forming a photoresist pattern on the third hard mask layer using an ArF exposure light source in order to form a predetermined pattern; forming a first hard mask pattern by etching the third hard mask layer using the photoresist pattern as an etching mask; etching the second hard mask layer and the first hard mask layer using at least the first hard mask pattern and forming a triple stacked hard mask pattern having the first hard mask pattern, a second hard mask pattern and a third hard mask pattern; and etching the conducting layer using triple stacked hard mask pattern as an etching mask and simultaneously removing the first hard mask pattern, whereby a stacked structure having the conducting layer, the second hard mask pattern and the third hard mask pattern is formed.
In accordance with a further aspect of the present invention, there is provided a method for fabricating a semiconductor device using an ArF exposure light source comprising the steps of: forming a conducting layer on a semiconductor substrate; forming a first hard mask layer and a second hard mask layer on the conducting layer in order; forming a photoresist pattern on the second hard mask layer using an ArF exposure light source in order to form a predetermined patter; forming a first hard mask pattern by etching the second hard mask layer using the photoresist pattern as an etching mask; etching the first hard mask layer using al least the first hard mask pattern and forming a second hard mask pattern, thereby forming a first resulting structure; depositing an insulation layer on the first resulting structure; and patterning the conducting layer using the second hard mask pattern as an etching mask.
In this invention, a conducting layer is patterned by a triple stacked hard mask to prevent a spire-shaped mask pattern. Since a spire-shaped pattern is removed from a triple stacked hard mask before etching the conducting layer, there is not any distortion of the pattern profile of the conducting layer.
Alternatively, a conducting layer is patterned by a dual stacked hard mask to prevent a spire-shaped mask pattern. The dual stacked hard mask is formed by three wet etching processes to remove a spire-shaped pattern.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and features of the instant invention will become apparent from the following description of preferred embodiments taken in conjunction with the accompanying drawings, in which:
FIG. 1A to 1C are cross-sectional views illustrating a conventional method for forming a conducting layer pattern in a semiconductor device.
FIG. 2 is a photograph taken by a SEM showing a spire-shaped top portion formed on a hard mask pattern;
FIG. 3 is a photograph taken by a SEM showing a conducting layer pattern formed by etching a conducting layer;
FIG. 4 is a photograph taken by a TEM showing a conducting later pattern having a stacked structure of tungsten and polysilicon layers.
FIG. 5A to 5D are cross-sectional views illustrating a method for forming a conducting layer pattern in a semiconductor device according to a first embodiment of the present invention;
FIG. 6A to 6D are cross-sectional views illustrating a method for forming a conducting layer pattern in a semiconductor device according to a second embodiment of the present invention;
FIG. 7A to 7E are cross-sectional views illustrating a method for forming a conducting layer pattern in a semiconductor device according to a third embodiment of the present invention; and
FIG. 8 is a photograph taken by a SEM showing a semiconductor device having a conducting layer pattern according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a method for fabricating a conducting layer pattern according to the present invention will be described in detail below.
FIG. 5A to 5D are cross-sectional views illustrating a method for forming a conducting layer pattern in a semiconductor device according to a first embodiment of the present invention.
First, referring to FIG. 5A , a conducting layer 51 to be etched is formed on a semiconductor substrate 50 on which different elements have been formed to implement a semiconductor device and a first layer 52 for a first hard mask, a second layer 53 for a second hard mask and a third layer 54 for a third hard mask are respectively formed in this order. The conducting layer 51 is a material selected from the group consisting of a tungsten layer, a titanium layer, a tungsten silicide layer and a titanium nitride layer. The first layer 52 for the first hard mask is a doped polysilicon layer or an undoped polysilicon layer and the second layer 53 for the second hard mask is a nitride layer, such as an oxynitride layer or a silicon nitride layer. Since the third layer 54 for the third hard mask is used as a sacrificial layer, this may be selected from the same materials as the conducting layer 51 . The first layer 52 for the first hard mask has a thickness in a range of 50 Ř100 Å and the third layer 54 for the third hard mask has a thickness in a range of 500 Ř1000 Å. The first layer 52 is relatively thinner than the third layer 54 .
Next, an antireflective coating layer 55 is deposited on the third layer 54 in order to prevent a random reflection in the photolithography process and to improve adhesive strength to the lower layer for an ArF photoresist layer. A photoresist layer 56 is formed on the antireflective coating layer 55 to form a predetermined pattern such as a gate electrode pattern. Organic materials may be used as the antireflective coating layer 55 and the photoresist layer 56 may be an ArF photoresist or any polymer of a COMA (CycloOlefin-Maleic Anhydride), Acrylate system and a mixture thereof.
Referring to FIG. 5B , the antireflective coating layer 55 and the third layer 54 for the third hard mask are etched using the photoresist layer 56 as an etching mask. By etching the antireflective coating layer 55 and the third layer 54 , an antireflective coating pattern 55 ′ and a hard mask pattern 54 ′ are formed and a pattern area is defined. At this time, the photoresist layer 56 is partially etched with the formation a photoresist pattern 56 ′.
Referring to FIG. 5C , a photoresist strip process is carried out to remove the photoresist pattern 56 ′ and the antireflective coating pattern 55 ′ and the second layer 53 is etched using the hard mask pattern 54 ′ to form a stacked structure of the hard mask pattern 54 ′ and a hard mask pattern 53 ′. At this time, the top portion of the hard mask pattern 54 ′ is lost when the hard mask pattern 53 ′ is formed so that a spire-shaped mask pattern 54 ″ is formed.
On the other hand, it is possible to naturally remove the photoresist pattern 56 ′ and the antireflective coating pattern 55 ′ at the formation of the hard mask pattern 53 ′ without carrying out the photoresist strip process.
In the first embodiment of the present invention, since the spire-shaped mask pattern 54 ″ can be projected to the lower layer, the spire-shaped mask pattern 54 ″ (shown in dotted lines) is removed by a wet etching process using SC- 1 (NH 4 OH:H 2 O 2 :H 2 O=1:4:20) solution. Also, since the spire-shaped mask pattern 54 ″ is used as a sacrificial layer and is the same material as the conducting layer 51 , the conducting layer 51 may be lost by the wet etching process. Accordingly, the first layer 52 for a first hard mask is positioned on the conducting layer 51 .
Referring to FIG. 5D , the first layer 52 and the conducting layer 51 are etched using the hard mask pattern 53 ′ as an etching mask, thereby forming a stacked hard mask pattern of a hard mask pattern 53 ′ and a hard mask pattern 52 ′ on a conducting pattern 51 ′.
In this embodiment, since the triple hard mask structure is used and the spire-shaped mask pattern 54 ″ is removed with the planarization on the hard mask pattern 53 ′, the etching profile of the hard mask pattern 52 ′ and the conducting layer 51 is not damaged.
FIG. 6A to 6D are cross-sectional views illustrating a method for forming a conducting layer pattern in a semiconductor device according to a second embodiment of the present invention.
First, referring to FIG. 6A , a conducting layer 61 to be etched is formed on a semiconductor substrate 60 on which different elements have been formed to implement a semiconductor device and a first layer 62 for a first hard mask, a second layer 63 for a second hard mask and a third layer 64 for a third hard mask are respectively formed in this order. The conducting layer 61 is a material selected from the group consisting of a tungsten layer, a titanium layer, a tungsten silicide layer and a titanium nitride layer.
The first layer 62 for the first hard mask is a LPCVD (Low Pressure Chemical Vapor Deposition) oxynitride layer and the second layer 63 for the second hard mask is a PECVD (Plasma Enhancement Chemical Vapor Deposition) oxynitride layer. The PECVD method produces the oxynitride layer at a high deposition rate. Since the density of the oxynitride formed by the LPCVD method is higher than that formed by the PECVD method, the thickness of the LPCVD oxynitride layer can be thinner than that of the PECVD oxynitride layer. To maximize this characteristic in this embodiment, the thickness of the second layer 63 of the PECVD oxynitride layer is two or more times as thick as the first layer 62 of the LPCVD oxynitride layer.
Since the third layer 64 for the third hard mask is used as a sacrificial layer, this may be selected from the same materials as the conducting layer 61 .
In case the third layer 64 and the conducting layer 61 are the same tungsten layers, since the tungsten layers are etched by SF 6 /N 2 plasma, a change of the ArF photoresist pattern can be minimized by using CF 4 /CHF 3 /Ar plasma at the time of etching a nitride layer. Accordingly, in the ArF photolithography process, a third layer 64 is preferably selected for the tungsten layer rather than a nitride layer.
An antireflective coating layer 65 is deposited on the third layer 64 in order to prevent a random reflection in the photolithography process and to improve adhesive strength to the lower layer for an ArF photoresist layer.
A photoresist layer 66 is formed on the antireflective coating layer 65 to form a predetermined pattern such as a gate electrode pattern. Organic materials may be used as the antireflective coating layer 65 and the photoresist layer 66 is an ArF photoresist or any polymer of a COMA (CycloOlefin-Maleic Anhydride), Acrylate system and a mixture thereof.
Referring to FIG. 6B , the antireflective coating layer 65 and the third layer 64 for the third hard mask are etched using the photoresist layer 66 as an etching mask. By etching the antireflective coating layer 65 and the third layer 64 , an antireflective coating pattern 65 ′ and a hard mask pattern 64 ′ are formed and a pattern area is defined. At this time, the photoresist layer 66 is partially etched with the formation a photoresist pattern 66 ′.
Referring to FIG. 6C , a photoresist strip process is carried out to remove the photoresist pattern 66 ′ and the antireflective coating pattern 65 ′ and the second layer 63 and the third layer 62 are etched using the hard mask pattern 64 ′ to form a triple stacked structure of the hard mask pattern 64 ′, a hard mask pattern 63 ′ and a hard mask pattern 62 ′. At this time, the top portion of the hard mask pattern 64 ′ is lost when the hard mask pattern 63 ′ is formed so that a round-shaped mask pattern 64 ″ is formed at the top thereof.
On the other hand, it is possible to naturally remove the photoresist pattern 66 ′ and the antireflective coating pattern 65 ′ at the formation of the hard mask pattern 63 ′ and the hard mask pattern 62 ′ without carrying out the photoresist strip process.
Referring to FIG. 6D , the conducting layer 61 is etched using the round-shaped mask pattern 64 ″, the hard mask pattern 63 ′ and the hard mask pattern 62 ′ as an etching mask, thereby forming a stacked hard mask pattern of the hard mask pattern 63 ′ and the hard mask pattern 62 ′ on a conducting pattern 61 ′. This embodiment can carry out an additional step of eliminating the round-shaped mask pattern 64 ″; however, the round-shaped mask pattern 64 ″ can be removed at the time of etching the conducting layer 61 without such an additional step.
In the second embodiment of the present invention, the spire-shaped mask pattern 64 ″ and the conducting pattern 61 ′ can be the same materials. The round-shaped mask pattern 64 ″ (shown in dotted lines) is removed at the time of patterning the conducting layer 61 .
As stated above in the first and second embodiments, since the triple hard mask structure is used for making the conducting pattern and the spire or round-shaped mask pattern is removed, the projection of the spire or round-shaped mask pattern is prevented and the etching profile of the lower mask patterns are not damaged.
FIG. 7A to 7E are cross-sectional views illustrating a method for forming a conducting layer pattern in a semiconductor device according to a third embodiment of the present invention.
First, referring to FIG. 7A , a conducting layer 70 to be etched is formed on a semiconductor substrate (not shown) on which different elements have been formed to implement a semiconductor device and a first layer 71 for a first hard mask and a second layer 72 for a second hard mask are respectively formed on the conducting layer 70 in this order.
The first layer 71 for the first hard mask is a nitride layer, such as an oxynitride layer or a silicon nitride layer and the second layer 72 for the second hard mask is a material selected from the group consisting of a tungsten layer and a tungsten nitride layer.
Next, an antireflective coating layer 73 is deposited on the second layer 72 in order to prevent a random reflection in the photolithography process and to improve adhesive strength to the lower layer for an ArF photoresist layer. A photoresist layer 74 is formed on the antireflective coating layer 73 to form a predetermined pattern such as a gate electrode pattern. The conducting layer 70 is a material selected from the group consisting of a tungsten layer, a titanium layer, a tungsten silicide layer and a tungsten nitride layer.
Organic materials may be used as the antireflective coating layer 73 and the photoresist layer 74 is an ArF photoresist or any polymer of a COMA (CycloOlefin-Maleic Anhydride) systems and a mixture thereof.
Referring to FIG. 7B , the antireflective coating layer 73 and the second layer 72 for the second hard mask are etched using the photoresist layer 74 as an etching mask. By etching the antireflective coating layer 73 and the second layer 72 , an antireflective coating pattern 73 ′ and a hard mask pattern 72 ′ are formed and a pattern area is defined. At this time, the photoresist layer 74 is partially etched with the formation of a photoresist pattern 74 ′.
Referring to FIG. 7C , the first layer 71 for the first hard mask is etched using the photoresist pattern 74 ′, the antireflective coating pattern 73 ′ and the second hard mask pattern 72 ′ as etching masks, thereby forming a stacked structure of the hard mask pattern 71 ′ and the spire-shaped mask pattern 72 ″. The top portion of the hard mask pattern 72 ′ is lost when the hard mask pattern 71 ′ is formed so that a spire-shaped mask pattern 72 ″ is formed. At this time, the photoresist pattern 74 ′ and the antireflective coating pattern 73 ′ are naturally removed.
In the third embodiment of the present invention, since the hard mask pattern 71 ′ can also have such a spire-shaped pattern when the spire-shaped mask pattern 72 ″ is projected to the lower layer, the spire-shaped mask pattern 72 ″ is removed.
FIGS. 7D and 7E cross-sectional views illustrating a method of removing the spire-shaped mask pattern 72 ″.
First, as shown in FIG. 7D , a flowable insulation layer or an organic polymer 75 is deposited on the resulting structure having the first hard mask pattern 71 ′ and the spire-shaped mask pattern 72 ″. The flowable insulation layer or the organic polymer 75 includes a SOG or APL layer and has a gap-fill characteristic with the flowing and planarization ability.
As shown in FIG. 7E , the polymer 75 and the spire-shaped mask pattern 72 ″ are removed by three steps of wet etching processes. If the flowable insulation layer is used, it is an oxide layer and a fluoride solution is used as an etchant. If the organic polymer is used, O 2 plasma is used as an etchant. Since the spire-shaped mask pattern 72 ″ is a tungsten material, SC- 1 (NH 4 OH:H 2 O 2 :H 2 O=1:4:20) solution is used as an etchant.
A portion of the flowable insulation layer 75 is removed by a wet etching process using the fluoride solution and the height of the removed portion is a half of that of the first hard mask pattern 71 ′ (see reference numeral “ 76 ”). The spire-shaped mask pattern 72 ″ is removed by a wet etching process using SC- 1 (NH 4 OH:H 2 O 2 :H 2 O=1:4:20) solution (see reference numeral “ 77 ”). A remaining insulation layer from the flowable insulation layer 75 is removed by a wet etching process using the fluoride solution (see reference numeral “ 78 ”). Further, the conducting layer 70 is patterned using the first hard mask pattern 71 ′ as an etching mask, which is not shown.
FIG. 8 is a photograph taken by a SEM showing a conducting layer pattern according to the present invention.
Referring to FIG. 8 , the first hard mask pattern 71 ′ is subjected to a planarization process through the deposition of the flowable insulation layer 75 and the removal of the spire-shaped mask pattern 72 ″ via three step wet etching processes with only a limited attack on the conducting layer 70 . In FIG. 8 , the reference SUB denotes a substrate and 70 ′ denotes a conducting layer pattern.
In the third embodiment of the present invention, a dual hard mask is used when patterning the conducting layer, the second hard mask pattern having a spire shape at the top thereof is removed by the deposition of the flowable insulation layer and three step wet etching processes. As a result, the spire-shaped mask pattern is not projected to the lower layer so that a continuous generation of spire shape is not prevented.
As apparent from the present invention, a tapered profile of the hard mask is prevented and the yield of the semiconductor devices increases.
While the present invention has been described with respect to the particular embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. Although the conducting layer in the present invention is illustrated, for example, the conducting layer is applicable to a bit line or other metal wires. | The present invention relates to a method for fabricating a conducting layer pattern using a hard mask of which an upper surface is flattened by the use of ArF exposure light source. The method includes the steps of: forming a conducting layer on a semiconductor substrate; forming hard mask layers on the conducting layer; forming a photoresist pattern on the hard mask layers using an ArF exposure light source in order to form a predetermined pattern; forming a first hard mask pattern by etching a second hard mask layer using the photoresist pattern as an etching mask; etching a first hard mask layer and forming a second hard mask pattern, thereby forming a first resulting structure; depositing an insulation layer on the first resulting structure; and patterning the conducting layer using the second hard mask pattern as an etching mask. | 7 |
FIELD OF THE INVENTION
[0001] This invention relates generally to safes, including wall safes, floor safes and free-standing safes and safe inserts with multiple security features.
BACKGROUND OF THE INVENTION
[0002] Until 1820, safes, or so-called “iron chests,” were designed to protect against burglars, but not fire. Safes that successfully protected against major building fires were not marketed until the early 1840s. After that, safes were routinely used in offices to protect against both fire and burglars. (See www.officemuseum.com or www.earlyofficemuseum.com.)
[0003] In 1826, Jesse Delano patented one of the earliest commercial fire-proof safes wherein a wooden enclosure was coated with a composition of clay and lime, plumbago and mica, or saturating the wood in a solution of potash lye and alum, to render it incombustible. In 1833, C. J. Gayler patented a ‘double’ fire-proof chest that consisted of two enclosures with spaces between them to enclose air or any known non-conductors of heat.
[0004] In 1830, Daniel Fitzgerald of New York patented a reliable fire proof safe using plaster of Paris as an insulating material. Fitzgerald was granted U.S. Pat. No. 3,117 on Jun. 1, 1843, for an “improvement in fire-proof chests and safes,” specifically the construction of what the patent identifies as a “Salamander Safe” made of heavy iron plates and filled with a three-inch layer of plaster of Paris in liquid form. Fitzgerald assigned the patent to Enos Wilder, who left it to his heir, Benjamin G. Wilder, and it became known as the “Wilder patent.” Between 1840 and 1860, numerous companies in New York City and Boston manufactured fire-proof Salamander safes under the Wilder patent.
[0005] Around 1870, Herring & Co. began to construct burglar-proof safes using boiler-plate wrought iron, with an inner safe of hardened steel, and then filled the space between with a casting of Franklinite, the hardest of all known metallic ores, which in casting was incorporated with rods of soft steel, those on one side running vertically, and those on the other horizontally. It was said that the castings resist the best drills for many hours. This proved the most complete protection against burglars so far invented.
[0006] Safes have evolved substantially since the nineteenth century. U.S. Pat. No. 6,040,771 describes “an intelligent safe system” that includes a housing, a lockable door and a central processing unit that controls access to the safe by operating the lockable door. The system further includes a card reader for reading access codes from an access card to control the lockable door and a sensor for detecting security violations. A modem transmits alarm signals from the CPU to indicate a security violation and for receiving external control data to lock or open the lockable door, and an audio alarm device indicates security violations. The central processing unit may further include a memory for storing the card numbers. A sensor may be coupled to the housing for detecting the locking an opening of the lockable door. A display may also be coupled to the housing for displaying acceptance of access codes. The sensor may include a horizontal detection sensor for detecting horizontal movement of the housing, a shock-detection sensor for detecting shock inflicted to the safe, and a thermo-detection sensor for detecting thermo-conditions being inflicted to the safe.
[0007] Though not a safe, the Gun Box (Lehi, Utah) is a handgun storing box that uses an on-board RFID scanner that syncs with a wristband/ring that has RFID chip for this specific functionality and with one wave over the box provides instant access to the contents. Apart from the RFID identification technique the Gun Box also opens using biometric fingerprint recognition and features alert notifications that send SMS text to a phone if it is tampered with, opened or moved from its original storage location. If stolen, in-built GPS technology will show its precise current location.
[0008] Despite such advances, safes that are used to secure firearms or valuables in a home have a flaw in pragmatic use. For example, a homeowner is sleeping at night and is awoken to the sounds of someone breaking into their home. Very likely the home is dark. The homeowner has a choice of turning on the light to access their safe and thereby inadvertently alerting the perpetrator(s) to their awareness of the break-in as well as his/her location. The home owners other option is to leave the lights off, causing him/her to fumble around in an attempt to access the safe in the dark, thereby loosing critical time for action, or not being able to open the safe in time at all.
[0009] Further, existing digital keypads (biometrics, etc.) can be compromised over a period of time by testing different codes/pins or access methods. Sometimes standard safes may have a notification that consists of a small warning light or an audible beeping upon next access. The problem with these methods are that the warning 1.) is only available when standing at the safe itself, 2.) temporary, as the notification clears itself out upon next access, and 3.) non-specific, only letting the owner know there was some kind of attempt, and 4.) most importantly, may not be noticed for a by the owner for a long time after the event, if at all. Some safes have a “lock-out” function, whereas after a factory specified number of failed attempts (3 to 5) the safe disallows another attempt for a specified amount of time, usually 60 seconds to 5 minutes. After the “lock-out” clears, more access attempts can be made. The owner would never know how many attempts were made or how many times the “lock-out” function was engaged.
SUMMARY OF THE INVENTION
[0010] This invention is directed to a secure safe system including tamper detection in the preferred embodiments. The safe system includes an enclosure having an outer surface and an inner compartment accessible through a door, and a door lock mechanism. An access device is provided for unlocking the door lock mechanism, thereby enabling a user to gain access to the compartment. An electronic controller, disposed within the enclosure, is interconnected to the access device and the door lock mechanism. The controller is operative to receive a signal from the access device and unlock the door lock mechanism for an authorized user. The outer surface of the enclosure is touch sensitive, and the controller is further operative to determine if a person has touched the touch-sensitive surface and, if so, cause a safe-related function to be performed. The outer surface of the enclosure may be metallic, or the enclosure may be covered or coated with a touch-sensitive surface. In the preferred embodiments the access device is also touch-sensitive. The touch-sensitive surface is preferably capacitive touch-sensitive.
[0011] The controller is interconnected to an external source of power, and a battery disposed in the enclosure is recharged by the controller in the event that power is interrupted. The access device includes an illuminated keypad, in which case the safe-related function may include illuminating the keypad. The system may further including communications circuitry to which the controller is interconnected, and the safe-related function may include sending a signal to a receiver remote from the enclosure. Such a signal may be wired or wireless. The system may further include a memory to which the controller is interconnected, in which case the safe-related function may include sending event information to the memory. The controller may be further operative to store an event log in the memory regarding successful and unsuccessful attempts to unlock the door lock mechanism through the access device. The memory may also store multiple access codes for different authorized users. The system may further include an RFID sensor disposed within the enclosure, with the controller being operative to scan and store information regarding items placed and locked in the enclosure.
BRIEF DESCRIPTION OF THE INVENTION
[0012] FIG. 1 is a perspective drawing of a safe unit constructed in accordance with the invention; and
[0013] FIG. 2 is a block diagram of important functional components.
DETAILED DESCRIPTION OF THE INVENTION
[0014] This invention improves upon existing safes with a combination of features that provide tamper-resistance and ultra-high security. As shown in FIG. 1 , the safe (or stand-alone device to be installed in a pre-existing safe or container, hereafter referred to as the “safe-unit” 100 ) contains an enclosure 102 with an outer surface, an access device 104 , and a control unit 110 internal to the enclosure.
[0015] The control unit includes a processing unit 122 and memory for logging, user administration of options, and event notifications, and smart decisions based on formulas of events and timing. Communication components network interface [wired and wireless], analog/voice phone, and/or a GSM/cellular), and various sensors, such as; capacitance sensor, door open/close sensor, key lock cylinder sensor.
[0016] The access device may be a keypad, key lock, combination dial, biometric device, or other appropriate mechanism. In contrast to existing systems, the entire outside surface of the unit is touch-sensitive. This includes the surface of the enclosure and the controls associated with the access method. In the preferred embodiments, these surfaces are made touch-sensitive using capacitive sensing technology. The outer surface of the enclosure is either metallic or coated with a touch-sensitive layer, and the keypad, lock, dial, biometric device, or other access device(s) is also rendered touch-sensitive.
[0017] FIG. 2 is a block diagram of the unit illustrating major components and attendant functionality. The controller 110 includes a controller board 112 including a processing unit and memory. The board 112 is interfaced to the capacitance touch sensors 114 , door-open sensor 116 , and reset/program button 118 . The controller also receives signals from the keypad 119 (if used) and communicates with key lock cylinder 121 and/or electro-magnetic lock 133 .
[0018] The controller also receives signals from a camera, and multiple data communication capabilities including one or more of an RJ-45 jack 122 to a local network; WiFi interface 124 ; RJ-11 phone jack 126 ; and cellular phone interface 130 . The invention is not limited in terms of communications capabilities, and may take advantage of any existing or yet-to-be-developed technologies. The controller may further include an interface to a premise alarm system at 132 , and may output current conditions to status/warning lights 136 . The system is powered with an AC power transformer/input 140 , but with long-lasting battery back-up 142 for added security. An interior light 134 comes on when the door 106 of the unit is opened.
[0019] Capacitive sensor(s) 114 detect if someone is touching any exposed surface of the unit, as well as the access control, cover over the video camera, etc. Upon detection of touch, the processing unit 112 will 1) illuminate the locking mechanism (digital keypad, combination lock dial, key bezel, biometric pad, or other devices used for limited access locking) 2) log the event, and 3) notify owner via a method(s) chosen by owner in device administration, such as SMS (text), email, prerecorded voice call, or smartphone app.
[0020] The use of touch-sensitive surfaces provides numerous advantages in accordance with the invention. Unless unarmed in advance, touching any part of the unit illuminates the keypad (or other access method), allowing the owner to utilize the keypad easily, and thereby access the safe-unit quickly and without turning on lights in the room. The capacitive sensing is also used in combination with various available communication methods providing the ability to notify the owner of specific events or combinations thereof in real-time. This solves several deficiencies of modern safes.
[0021] The unique and advantageous solution of using capacitive-sense in conjunction with access methods (keypad code inputs, door open, etc.) and communications allows the owner to receive immediate notification of the specific status of the unit as well as the ability to determine if immediate action is necessary. For example, if the safe-unit face, bezel, or keypad is touched, the owner is informed immediately. Additional individual notifications are sent to the owner if someone tried an invalid pin-code, a valid pin-code, and if the door was opened. The safe-unit would continue to send notifications for each new or repeated event. The safe-unit system will log each event with a date-time stamp, its type, and relevant information such as a specific pin code attempted.
[0022] If the safe-unit is hidden behind a picture, it can be assumed that no one except the owner or authorized persons would be touching the safe-unit, even accidentally. Of course there are always exceptions (maybe the housekeeper is dusting and moved the picture), but with the notification sent by the safe-unit, the owner would have knowledge of such an event, and be able make a decision of whether or not to investigate or take action. If the owner receives notification that the safe-unit was touched and then a short time later an invalid pin-code was attempted, he/she would have even more information to make a decision whether or not to investigate and/or take action. For instance, a home in which a troubled teenager resided, whereas the teenager decided to attempt different codes to access the safe-unit. With most safes the teenager could try many different pin-codes every day after school, and may eventually hit the correct pin-code. With this safe-unit the teenagers actions immediately known and intent would evident.
[0023] In addition, the ability of the safe-unit to use user-specific pin codes and the built-in camera would also either identify the person accessing the safe-unit or making the attempt, make it clear of intent if the camera was covered during such attempt, or give clues to how the pin-code may have been compromised by logging the attempted pin-code or valid pin-code used.
[0024] Furthermore, to make sure that the above features and notifications are not circumvented, there are 3 contingencies.
[0025] 1) A “stay-alive” ping function that works with a smartphone app. If someone wanted to make access attempt and circumvent the notifications by disconnecting the safe-unit from the network switch or router, the smartphone app would detect lost communication by failure to receive a response from pings sent at preset intervals, and notify the owner.
[0026] 2) The battery back-up in combination with event logging would circumvent attempts to stop notifications from being sent by cutting power to the unit or network. The safe-unit would continue to monitor itself and keep a log of events. Upon network power recovery, the unit would send the notifications. Event logs could also be viewed via the html interface via the LAN (local area network) at the owner's leisure.
[0027] 3) To prevent attempted circumvention of both communications and power disruption and continue real-time notifications, an internal cellular/GSM unit would continue to send notifications via voice/SMS/data. The cellular/GSM unit may be built-in or may be an optional add-on connected via a USB port on the unit.
[0028] The combination of AC power with a battery back-up serves the secondary function of power reliability in emergency situation whereas the safe must be accessed immediately.
Overview of Preferred and Alternative Embodiments
[0029] In broad and general terms, this invention applies to different types of safes, including wall, floor, and free-standing safes. In addition, the principles of this invention are applicable to secure inserts received by existing safes. Accordingly, in accordance with this disclosure, “safe” should be taken to include wall, floor, and free-standing safes, as well as inserts therefor. In preferred embodiments, these safes include some form of digital access method (keypad, biometric, etc.) and/or key locks.
[0030] Unique to the invention is touch-sensitive tamper notification. When the front-face, door or keypad (or other utilized electronic access method) is contacted by human touch, alarms may be generated, the event is logged, and a notification is sent to the safe owner/user via the communication(s) method chosen in the administration. Event logging keeps track of and saves data regarding sensor inputs (date/time stamped, which user or access code or attempted access code). Capacitive Sensing (touch-sensitive) may be provided on the front face bezel and/or door. Capacitive sensing also used for “tamper” network notifications.
[0031] Certain embodiments may include touch-sensitive keypad illumination. The keypad lights/illuminate upon contact of human touch to faceplate, bezel, door, keypad (or other utilized electronic access method) or unlocking handle. Interior LED lights (ON while door is open). A disable switch may be located on the door interior, or an ON/OFF switch located on door interior not operated by door) (optional auto disable when operating on battery back-up). A “door-open” sensor (magnetic contact or other) may be used to turn on interior lights. A “door-left-open” notification; door opened by key (keypad bypass) notification; and/or alarm system notification may be provided in accordance with appropriate parameters. Notification lights may be located on front of safe. Different colors, combinations of colors, or flashing to be alternate method of notification to owner/user of events or status. Alternatively, keys or keypad could be used as alternative method of notifications.
[0032] Communication components are provided to send notifications of events or predetermined combinations of events. Such components may include, without limitation, wired network(s), wi-fi, cellular phone, analog phone, and premise alarm connection(s). Event notifications may be delivered via email, SMS and DDNS Phone App connection (via home network wi-fi or wired, analog phone line, or cellular network).
[0033] The units are preferably AC powered with battery back-up. Safe electrical components are powered by premise wired AC electrical power. In the event of a premise wired AC power failure the safe will automatically switch to the built-in battery back-up power source. The system preferably remembers notification states after power loss (ex; invalid access attempt notification LED).
[0034] To ensure fail-safe operation, the safe battery is rechargeable and replaceable. Charging is controlled by the devices CPU by method known as “smart charging” to prevent overcharging. The CPU's smart charging method will also be able to detect decreased battery capacity (from age and/or use) and notify the owner/user that the battery is in need of replacement. Safe interiors may contain lights inside the body (storage area) to allow persons accessing the safe to better see its contents. When provided, light will illuminate when the door is open. This function can be limited to AC power operation only, AC and battery power, or turned off completely as chosen by owner/user.
[0035] Administration may be provided via html interfaces through standard wired/wireless network access. The owner/user can use a networkable device (such as a desktop PC, laptop, tablet or phone) that uses some form of internet browser software, to view/change administration settings (such as communication, network, notification types, notification messages, users, access codes, user permissions, interior lights, and power settings) and view logs. “Stay alive” constant monitoring of connections may be provided warn of disrupted communications. Phone software application sends ping to safe at predetermined intervals, safe answers ping. When no response to ping is received from the safe by the phone app, disrupted communications will be assumed and phone app will alert owner/user.
[0036] Certain embodiments may be multiple user access code/identification capable. That is, multiple users may be given access codes or can be granted access via other access methods that may be used (such as biometric finger prints). To be used for access/unlocking of safe, notifications and event logs stating which specific user accessed safe. To ensure premise security system compatibility, output connection(s) to be connected to premise alarm systems (for standard alarm system zone and/or duress).
[0037] Ultra-secure embodiments will provide cut-out deterrent systems. Reinforcement “rails” prevent or slow down process of safe being forcibly removed or cut out of wall. Elongated rails or bar-like structures attached to exterior of safe body sides and wall studs. Made from suitable material to make cutting by manual or machine methods as difficult as possible, and may be up to full height of wall studs. Provided structures may also contain wire that, when cut, will be part of the safes event notification system.
[0038] A peg-board system in rear wall and sides of the safe may be provided for accessory attachments (shelves, pistol holder, etc.) Holes in grid pattern allowing for flexibility of placement and a variety of, and different size, accessories. Holes may be threaded for secure attachment of accessories.
[0039] RFID sensors may be used to provide item inventory detection; that is, to track items with RFID tags placed in the safe. This capability may be used to view current contents of safe via html interface or mobile app, or for notification when RFID tagged item is removed from or placed in safe.
[0040] Notification of changes to admin may be generated to ensure seamless transitions between owners/users. “Old” contact info may be stored for future reference. A lock-out function may be used after X number of invalid attempts within a predetermined period of time. Lock-out can be reset manually by method yet to be determined (such as opening safe door with physical key or opening safe via electronic keypad and/or pressing reset button located inside safe). In addition, an html administration interface may effectuate lock-out after X number of invalid login attempts within a predetermined period of time. Lock-out can be reset manually by method yet to be determined (such as by manual safe access via key or keypad).
[0041] The systems are preferably direct wired (AC powered) with Battery back-up). A jack for an AC Adapter to power/recharge may be provide on front face of safe (in case of no in-wall wiring ability or in event of problem with in-wall wiring). Battery back-up will preferably be a standard rechargeable NiMH or Li-ion battery pack, or may be customized for device. Battery back-up may last several months without AC power supply for extended security in the event of a power loss. As such, in the event of a power loss from premise wired AC power supply everything will continue to operate normally under battery back-up with the following specifications. Other options include:
[0042] 1) network connection will power off to reserve battery power (if network connection loss is detected);
[0043] 2) Smart phone app will detect that there is no connection to safe and alert user;
[0044] 3) Safe will continue to monitor trigger events (keypad attempts, capacitive sense, door openings, etc.);
[0045] If trigger event occurs, the safe will still:
a) log event; and b) power on network connection (via battery) for just long enough to send alerts via sms, email, app, etc.
[0048] Upon AC power resumption, logged events will “sync” with app or be sent via notification methods.
Typical Functions/Programming
[0049] A primary access code will be programmed for safe entry via specific method using the keypad in possible combination of other safe inputs, such as the reset button located inside safe. The owner/user enters access pin-code to unlock safe allowing door to be opened (or other “code” depending on method of digital access used, such as finger, thumb or hand print in the case of biometric digital access).
[0050] Network functions. log data, camera images, and safe settings are preferably accessible via local area network (LAN). Event logging may include valid access and invalid access attempts, by user access code, etc. Multiple users (non-admin) may be accommodated for access logging purposes. View/save camera images may be time-stamped and recorded by event (date and time). Wide Area Network (WAN) data may be limited to only outgoing for email/SMS/app and incoming ping for “stay-alive” function.
[0051] The primary password may be programmable via keypad as well as possibly through html/WAN administration. A button procedure may be provided for “Reset to Default”/set main pin# (lost password, must access via physical key)
Event Notifications Sent by Safe Unit
[0052] Valid access via keypad (or other digital or biometric method)
[0053] Keypad bypassed access (door opened without use of use of keypad (or other digital or biometric method)
[0054] Invalid access attempt (incorrect access pin entered) (or invalid fingerprint or other biometric entered)
[0055] Lock-out has been enabled due to too many invalid pin-code access attempts
[0056] HTML administration lock-out has been enabled do to too many invalid password attempts
[0057] Capacitive/touch sense positive (tamper notification)
[0058] Pin change via keypad
[0059] Change made to administration and/or set-up. (if contact method is changed, notification is sent via old contact method(s) prior to completion of saving new settings.
[0060] Door left open. If door is left open for a specified period of time a notification is sent.
[0061] Diminished battery capacity. Batteries become old and wear out. When the batteries capacity falls below a predetermined level a notification is sent.
[0062] Emergency lock release via mobile app has been activated. Safe can be unlocked via the mobile app without revealing access pin-code. If this occurs, notification is sent.
[0063] AC power loss. If enough power left in back-up battery and connection is still live, notification is sent upon loss of premise wired AC power. If not enough power left in battery notification is sent upon resumption of power.
[0064] Duress signal—When specialized “duress” pin code is entered, door is unlocked AND device sends signal to premise alarm notifying alarm company that hostage/burglary situation is in progress. (Note: duress functions are common in monitored commercial alarm systems)
Smartphone/Mobile Phone App
[0065] A smart or mobile phone “app” may be provided to receive some or all of the notifications from the safe as set forth above. Other capabilities may include the following:
[0066] “Stay-alive” function. The mobile app monitors the connection between itself and the safe by sending “pings” at specified intervals and awaits a response from the safe. If no response is received a connection failure is assumed and app user is notified (possible indications are that there is a power loss or communications failure at the safe).
[0067] Emergency remote lock release. The mobile app user may enter an access pin-code to unlock the safe remotely, and thereby not reveal the pin-code to the person it is being opened for.
[0068] Safe remembers notification state and events after power loss sends to app and other notification methods after AC power resumes.
Camera Functionality
[0069] The unit may be provided with a camera to capture pictures of anyone attempting to open, or tampering with/touching, the safe. The camera records images at specified intervals (ex. 1 to 30 images per second). Images are temporarily stored for a specified amount of time (ex. 1 to 60 minutes) based on the size of an allocated portion of the devices memory for this purpose. The newest images replace the oldest on a rolling basis. At time of predetermined events, all current pictures/video are saved (removed from allocated rolling memory and saved for later viewing). Pictures can be viewed via app after user receives notification of event and/or user can view or download saved images from the safe via device connected to local network using the html administration interface.
Physical Considerations
[0070] Safes and inserts constructed in accordance with this invention may be provided in various sizes and configurations. Wall, floor and free-standing configurations may be of varying depths, heights and widths, including small (i.e., square); medium (i.e., vertical rectangle), and rifle height. Floor safe configurations may be provided in multiple sizes including standard and rifle). | A secure safe system with tamper detection includes an enclosure having an outer surface and an inner compartment accessible through a door, and a door lock mechanism. An access device is provided for unlocking the door lock mechanism, thereby enabling a user to gain access to the compartment. An electronic controller, disposed within the enclosure, is interconnected to the access device and the door lock mechanism. The controller is operative to receive a signal from the access device and unlock the door lock mechanism for an authorized user. The outer surface of the enclosure is touch sensitive, and the controller is further operative to determine if a person has touched the touch-sensitive surface and, if so, cause a safe-related function to be performed. The outer surface of the enclosure may be metallic or covered or coated with a touch-sensitive surface. The access device is also preferably touch-sensitive. | 4 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 12/412,880 filed Mar. 27, 2009, which claims priority to U.S. Provisional Application No. 61/191,887 filed Sep. 13, 2008. The disclosures of both applications is hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present application relates to container systems and, more particularly, to bag-in-box container systems for interaction with spraying or dispensing systems.
BACKGROUND
[0003] Humans apply many products to their bodies for cosmetic purposes. These products include moisturizers, sunscreens, anti-aging treatments, UV tanning accelerators, sunless tanning products, and so on. Numerous forms of artificial tanning products are currently available, including lotions, creams, gels, oils, and sprays. These products are typically mixtures of a chemically-active skin colorant or a bronzer, in combination with moisturizers, preservatives, antimicrobials, thickeners, solvents, emulsifiers, fragrances, surfactants, stabilizers, sunscreens, pH adjusters, anti-caking agents, and additional ingredients to alter the color reaction.
[0004] Systems exist for applying artificial tanning products including spraying booths for fluid containment used in conjunction with handheld sprayers, and closed booths equipped with automated spraying systems. These spraying systems may use high pressure compressed air nozzles along with sunless tanning composition fluids supplied to the nozzle to create atomized sprays directed towards the body. Sunless tanning composition fluids, as well as fluids in countless other applications, must be packaged in containers suitable for transportation of the fluids, for interaction with spraying or dispensing systems, and for economically efficient disposal.
[0005] Conventionally, fluids have been packaged in rigid containers that provide satisfactory interaction with spraying or dispensing systems. However, these rigid containers are inefficient in terms of storage and disposal of empty containers because they retain their volume even after the fluids have been exhausted. Flexible containers such as bag-in-box containers provide more economically efficient containers in terms of storage and disposal. However, conventionally, these flexible containers have been used in applications that rely on pressurized air for evacuation of fluid from the bag while the bag-in-box system is sitting upright. Conventional, bag-in-box systems do not provide a sufficiently rigid container for proper interaction with spraying and dispensing systems that require upside-down installation for gravity to assist, at least in part, in the evacuation of the contents in the bag. Some of these upside-down applications may require also require a blind connection to be made between the bag-in-box system and dispensing machinery.
SUMMARY
[0006] In one embodiment, a method of providing fluid to a dispensing machine includes providing a bag having a dispensing end, the bag having fluid disposed therein. The method further includes providing a box in a first orientation. The box has a first wall with an opening disposed therein. The method also includes providing a dispensing machine having a holder configured to receive the dispensing end of the bag. The method further includes inserting the bag in the box, and closing the box with a portion of the dispensing end of the bag protruding through the opening in the first wall, wherein the first wall is a top surface of the box in the first orientation. The method also includes securing the portion of the dispensing end outside of the box and inverting the box to a second orientation, such that the first wall is a bottom surface of the box in the second orientation. The method further includes inserting the dispensing end of the bag into the holder of the dispensing machine.
[0007] In another embodiment, a method of employing a bag-in-box container system in a dispensing machine includes providing a bag-in-box container system. The bag-in-box container includes a box having a first wall with an opening disposed therein. The first wall is a top surface when the box is in a first orientation and the first wall is a bottom surface when the box is in a second orientation. The bag-in-box container system further includes a bag disposed inside the box, the bag having a dispensing end that protrudes through the opening in the first wall of the box. The method further includes providing a dispensing machine having a holder configured to receive the dispensing end of the bag. The method also includes placing the bag-in-box container system in the second orientation, and inserting the dispensing end of the bag into the holder of the dispensing machine.
[0008] In yet another embodiment, a method of employing a bag-in-box container system in a dispensing machine includes placing a box in a first orientation, inserting a bag in the box, and closing the box with a portion of a dispensing end of the bag protruding through an opening in a first wall of the box. The first wall is a top surface of the box in the first orientation. The method further includes securing the portion of the dispensing end outside of the box and inverting the box to a second orientation, such that the first wall is a bottom surface of the box in the second orientation. The method also includes inserting the dispensing end of the bag into a holder of a dispensing machine.
BRIEF DESCRIPTION OF DRAWINGS
[0009] The accompanying drawings, together with the detailed description provided below, describe exemplary embodiments of the claimed invention. In the drawings and description that follow, like elements are identified with the same reference numerals. The drawings are not to scale and the proportion of certain elements may be exaggerated for the purpose of illustration.
[0010] FIG. 1 illustrates a perspective front view of an embodiment of a bag-in-box container system.
[0011] FIG. 2 illustrates a perspective rear view of an embodiment of a bag-in-box container system.
[0012] FIG. 3 illustrates a perspective front exploded view of an embodiment of a bag-in-box container system.
[0013] FIG. 4 illustrates a perspective front exploded view of an embodiment of a bag-in-box container system with a clip.
[0014] FIG. 5 illustrates an exploded view of an embodiment of a bag-in-box container system.
[0015] FIG. 6 illustrates a perspective view of an embodiment of a bag-in-box container system
[0016] FIG. 7A illustrates a perspective front view of an embodiment of a bag-in-box container system.
[0017] FIG. 7B illustrates a perspective top view of an embodiment of a bag-in-box container system.
[0018] FIG. 8 illustrates a partially assembled example application for a bag-in-box container system.
[0019] FIG. 9 illustrates an expanded or close up view of the partially assembled example application for bag-in-box container systems of FIG. 8 .
[0020] FIG. 10 illustrates a completely assembled example application for a bag-in-box container system.
[0021] FIG. 11 illustrates an expanded or close up view of the completely assembled example application for a bag-in-box container system of FIG. 10 .
DETAILED DESCRIPTION
[0022] The following includes definitions of selected terms. The definitions include various examples or forms of components that fall within the scope of a term. The examples are not intended to be limiting.
[0023] FIG. 1 illustrates a perspective front view of an embodiment of a bag-in-box container system. The example container system 100 includes a box 1 . Box 1 may be constructed of various different materials (cardboard, plastic, and so on) to give box 1 suitable rigidity, weight, etc. for the specific application. Example container system 100 also includes a bag 2 . Bag 2 may contain liquids such as those used for sunless tanning, as well as other liquids for various other uses. Bag 2 may have a valved fitting or dispensing end 3 that may provide a fluidic path for the fluid in bag 2 . Example box 1 has an opening on one of its walls for the dispensing end 3 to partially come through. Dispensing end 3 may have annular ringed flanges or ribs for, among other functions, connecting system 100 to equipment or machinery using the fluids inside of bag 2 . Dispensing end 3 may also include a collar (not shown) of a larger perimeter than the opening in box 1 such that the collar contacts the inside of box 1 around the opening. The contact between the collar and the inside of box 1 resists bag 2 from being pulled out of the box through the opening. Dispensing end 3 may also include a flange, rib, or set of flanges or ribs forming a groove or slot for a clip 4 , a spring clip (not shown), or some other means of engagement to engage dispensing end 3 and resist a force pushing in a direction towards the inside of box 1 .
[0024] FIG. 2 illustrates a perspective rear view of an embodiment of a bag-in-box container system 100 . In the example embodiment, dispensing end 3 includes a groove 5 . The example embodiment also includes a clip 4 that engages groove 5 to hold dispensing end 3 in place relative to box 1 . Engagement of groove 5 and clip 4 causes clip 4 to resist a force urging dispensing end 3 inside box 1 by, for example, force exerted on dispensing end 3 when connecting system 100 to dispensing or spraying machinery. During and after connection to the machinery, clip 4 distributes, at least partially, the force exerted on dispensing end 3 along the opening end outside wall of the box contributing to the rigidity of system 100 .
[0025] Clip 4 may have an opening for sliding in place into groove 5 in dispensing end 3 . Groove 5 may be formed by two spaced walls or flanges radially extending from dispensing end 3 . Groove 5 may be located in dispensing end 3 so that the proximal most wall or flange of groove 5 is flush with the outside surface of the opening wall of box 1 . In this example embodiment, groove 5 is disposed immediately outside of box 1 near the opening. Clip 4 may then engage dispensing end 3 at groove 5 with at least some surface area of clip 4 remaining in contact with the outside surface of the opening wall of box 1 , providing for very little, if any, play of dispensing end 3 in and out of box 1 .
[0026] Engaging a portion of dispensing end 3 outside box 1 may be accomplished by various other means. In an example prophetic embodiment, engagement of a groove 5 is accomplished by a flap integral to box 1 that slides into groove 5 and prevents dispensing end 3 from pushing into box 1 through the opening. In another prophetic embodiment, dispensing end 3 may be engaged by inserting a grooved insert into a flange in dispensing end 3 . Dispensing end 3 may be alternatively or additionally engaged by a spring clip (not shown) that engages groove 5 . Various other methods of engagement may be used.
[0027] FIG. 3 illustrates a perspective front exploded view of an embodiment of a bag-in-box container system. In the example embodiment, bag-in-box container system 100 includes box 1 and bag 2 . To assemble bag-in-box system 100 , bag 2 is inserted inside box 1 , and box 1 is closed with a portion of dispensing end 3 protruding through opening 6 . Dispensing end 3 may also include a collar 7 of a larger perimeter than opening 6 such that collar 7 contacts the inside surface of top wall 8 around opening 6 . The contact between collar 7 and the inside surface of top wall 8 resists bag 2 from being pulled out of the box through opening 6 . Bag 2 may be manufactured of a flexible material. Box 1 may be designed and manufactured such that when fully assembled, bag-in-box system 100 with clip 4 engaged in groove 5 mimics a single, stable, rigid container.
[0028] In example system 100 , opening 6 and collar 7 are shown to have circular geometries. In the example embodiment, the perimeters of opening 6 and collar 7 would be their respective circumferences. However, opening 6 and collar 7 may be of various non-circular geometries (square, oval, rectangular, and so on). In an alternate embodiment, collar 7 would be reinforced or supported by an additional clip (not shown) disposed inside box 1 and held in position with or without an additional groove on dispensing end 3 .
[0029] FIG. 4 illustrates a perspective front exploded view of an embodiment of a bag-in-box liquid container system 100 with a clip 4 . In the example embodiment, after bag 2 has been inserted inside box 1 with dispensing end 3 protruding through opening 6 , clip 4 may be inserted or slid into groove 5 . Clip 4 has a shape complimentary to groove 5 such that clip 4 tightly fits on to groove 5 when pressed into engagement position. In this embodiment, clip 4 has a U-shaped opening. The U-shaped opening defines an engaging surface 9 for clip 4 to engage groove 5 of dispensing end 3 protruding through opening 6 in a wall of box 1 . In a prophetic embodiment, engaging surface 9 may be part of a flap, integral to or separable from box 1 , that slides into groove 5 to secure dispensing end 3 in place. In another prophetic embodiment, the engaging surface may be part of a spring clip or similar structure that engages groove 5 or some other portion of dispensing end 3 to secure dispensing end 3 in place. In other embodiments, engaging surface 9 could be formed by a discontinuous engaging surface or multiple engaging surfaces.
[0030] In one embodiment, clip 4 has top and bottom surfaces 10 and 11 , respectively. In the example embodiment, when clip 4 is fully inserted into groove 5 , top surface 10 contacts the distal wall of groove 5 preventing dispensing end 3 from recessing into box 1 through opening 6 . The bottom surface 11 , in turn, distributes at least some of the force applied to dispensing end 3 across the top wall 8 of box 1 . This distribution of force along the larger area of top wall 8 makes bag-in-box system 100 relatively rigid. The rigidity of system 100 makes it suitable for connecting to dispensing equipment even when system 100 is inverted upside-down and connected to dispensing equipment in a blind connection where substantial force may be exerted on system 100 to permit dispensing end 3 to connect to a mating fitting fixed to dispensing machinery. System 100 may be sufficiently rigid to be self supporting in such an application when mounted by means of dispensing end 3 in an inverted angled or upside-down orientation.
[0031] In one embodiment, engaging surface 9 may have dimples for a snap engagement between clip 4 and groove 5 . In another embodiment, engaging surface 9 may have a total engaging circumference in excess of half the outside circumference of groove 5 for a snap engagement. Clip 4 , among other embodiments, could also be a spring clip (not shown) that may be compressed, placed over groove 5 , and released to engage groove 5 . Clip 4 may be fabricated of various known materials (e.g. plastic, metal, and so on).
[0032] After the contents of bag 2 have been exhausted, the bag-in-box system 100 may be removed from the dispensing machinery, clip 4 may be removed from groove 5 , box 1 opened, bag 2 removed from box 1 , and both box 1 and bag 2 may be collapsed to a relatively small volume to be discarded or recycled.
[0033] FIG. 5 illustrates an exploded view and FIG. 6 illustrates a perspective view of an embodiment of a bag-in-box container system 500 . The example container system 500 includes a box 12 . Box 12 may be constructed of various different materials (cardboard, plastic, and so on) to give box 12 suitable rigidity, weight, etc. for the specific application. Example container system 500 also includes a bag 13 , which may contain liquids such as those used for sunless tanning, as well as other liquids for various other uses. Bag 13 may have a valved fitting or dispensing end 14 that may provide a fluidic path for fluid in bag 13 . Dispensing end 14 may also have annular ringed flanges or ribs for, among other functions, connecting system 500 to equipment or machinery for dispensing the fluids inside of the bag.
[0034] Example box 12 has an opening 15 on one of its walls. Dispensing end 14 may include a flange, rib, or set of flanges or ribs forming a groove or slot 16 and opening 15 may incorporate two different diameters for dispensing end 14 to partially come through the larger diameter and engage into the smaller diameter at groove or slot 16 to resist a force pushing in a direction towards the inside of box 12 . Dispensing end 14 may also include a collar 17 of a larger perimeter than the smaller diameter in opening 15 such that the collar contacts the inside of box 13 around the smaller diameter resisting bag 13 from being pulled out of box 12 through opening 15 . Engagement at groove or slot 16 resists a force urging dispensing end 14 inside box 12 by, for example, force exerted on dispensing end 14 when connecting system 500 to dispensing or spraying machinery. During and after connection to the machinery, this force exerted on dispensing end 14 is distributed along the wall surface of box 12 around opening 15 contributing to the rigidity of system 500 .
[0035] In one embodiment, system 500 may include a lid 18 for closing the bag-in-box container. After the contents of bag 13 have been exhausted, the bag-in-box system 500 may be removed from the dispensing machinery, lid 18 removed, bag 13 removed from box 12 , and bag 13 may be collapsed to a relatively small volume to be discarded or recycled. Box 12 may be “refilled” with a full bag 13 , reassembled and reinstalled on the dispensing machinery.
[0036] FIGS. 7A and 7B illustrates a perspective front view and a top view, respectively, of an embodiment of a bag-in-box container system 700 . The example container system 700 includes a box 19 . Box 19 may be constructed of various different materials (cardboard, plastic, and so on) to give box 19 suitable rigidity, weight, etc. for the specific application. Example container system 700 also includes a bag 20 . Bag 20 may contain liquids such as those used for sunless tanning, as well as other liquids for various other uses. Bag 20 may have a valved fitting or dispensing end 21 that may provide a fluidic path for the fluid in bag 20 . Dispensing end 21 may have annular ringed flanges or ribs for, among other functions, connecting system 700 to equipment or machinery for dispensing the fluids inside of bag 20 . Example box 19 has an opening on one of its walls, in this example top wall 23 , for dispensing end 21 to partially come through the opening.
[0037] To assemble bag-in-box system 700 , bag 20 is inserted inside box 19 with a portion of dispensing end 21 protruding through the opening on wall 23 . Dispensing end 21 may also include a collar (not shown) of a larger perimeter than the opening in box 19 such that the collar contacts the inside of wall 23 around the opening. The contact between the collar and the inside of wall 23 resists bag 20 from being pulled out of box 19 through the opening. Dispensing end 21 may also include a flange, rib, or set of flanges or ribs forming a groove or slot for a clip 22 , a spring clip (not shown), or some other means of engagement to engage dispensing end 21 and resist a force pushing in a direction towards the inside of box 19 .
[0038] In the example embodiment, clip 22 engages dispensing end 21 at a groove in dispensing end 21 and holds bag 20 in place relative to box 19 . Engagement of dispensing end 21 and clip 22 causes clip 22 to resist a force urging dispensing end 21 inside box 19 by, for example, force exerted on dispensing end 21 when connecting system 700 to dispensing or spraying machinery. During and after connection to the machinery, clip 22 distributes, at least partially, the force exerted on dispensing end 21 along the opening end outside wall of box 19 , in this case top wall 23 , contributing to the rigidity of system 700 .
[0039] Clip 22 may have an opening for sliding in place into the groove in dispensing end 21 . The groove may be formed by two spaced walls or flanges radially extending from dispensing end 21 . The groove may be located in dispensing end 21 so that the proximal most wall or flange of the groove is flush with the outside surface of the opening wall of box 19 . In this example embodiment, the groove is disposed immediately outside of box 19 near the opening on wall 23 . Clip 22 may then engage dispensing end 21 at the groove with at least some surface area of clip 22 remaining in contact with the outside surface of wall 23 , providing for very little, if any, play of dispensing end 21 in and out of box 19 .
[0040] Bag 20 may be manufactured of a flexible material. Box 19 may be designed and manufactured such that when fully assembled, bag-in-box system 700 with clip 22 engaged mimics a single, stable, rigid container.
[0041] In the example embodiment, after bag 20 has been inserted inside box 19 with dispensing end 21 protruding through the opening on wall 23 , clip 22 may be inserted or slid into the groove in dispensing end 21 . Clip 22 has a shape complimentary to the groove such that clip 22 tightly fits on to the groove when pressed into engagement position. In the example embodiment, when clip 22 is fully inserted into the groove, it prevents dispensing end 21 from recessing into box 19 through the opening. A bottom surface of clip 22 , in turn, distributes at least some of the force applied to dispensing end 21 in the direction to the inside of box 19 across the top wall 23 . This distribution of force along the larger area of top wall 23 contributes in making bag-in-box system 700 relatively rigid. The rigidity of system 700 makes it suitable for connecting to dispensing equipment even when system 700 is inverted upside-down and connected to dispensing equipment in a blind connection where substantial force may be exerted on system 700 to permit dispensing end 21 to connect to a mating fitting fixed to dispensing machinery. System 700 may be sufficiently rigid to be self supporting in such an application when mounted by means of dispensing end 21 in an inverted angled or upside-down orientation.
[0042] FIG. 8 illustrates a partially assembled example application 800 for bag-in-box container systems interacting with portions of a dispensing machinery 810 . FIG. 9 illustrates an expanded or close-up view of the partially assembled example application 800 of FIG. 8 . In example application 800 , multiple bag-in-box liquid systems 100 a, 100 b, and 100 c may be inserted into fixed holders 820 a, 820 b, and 820 c that may be part of dispensing machinery 810 . Bag-in-box system 100 a, for example, is inverted for connection to holder 820 a. When system 100 a is inverted a force F 1 including the weight of the liquid inside system 100 a, is exerted on the collar that forms part of the dispensing end against the inside surface of the opening end wall of the box. The weight tends to push the dispensing end in a direction outside of the box through the opening. The collar resists the dispensing end from being pushed out the box by force F 1 .
[0043] FIG. 10 illustrates a completely assembled example application 1000 for bag-in-box container systems interacting with portions of dispensing machinery 810 . FIG. 11 illustrates an expanded or close-up view of the completely assembled example application 1000 of FIG. 10 . In example application 1000 , multiple bag-in-box systems 100 a, 100 b, and 100 c have been inserted into fixed holders 820 a, 820 b, and 820 c, respectively, that may be part of dispensing machinery 810 . Bag-in-box system 100 b, for example, is inverted for connection to holder 820 b. Once system 100 b is inverted and connected to holder 820 b, a force F 2 representing the entire weight of system 100 b, including the weight of the liquid inside system 100 b, is exerted on the dispensing end pushing the dispensing end in the direction of the inside of system 100 b. However, one of the walls that form the groove in the dispensing end transfers the weight to the clip engaging the dispensing end or other means of engagement, and effectively distributes at least some of the weight of system 100 b along the opening surface of the box. The distribution of weight makes system 100 b more rigid, stable, and reliable than a comparable system without the weight distribution attributes of the clip or other means of engagement. Moreover, in the example embodiment, system 100 b is sufficiently strong to withstand force F 2 even when force F 2 includes force applied to the dispensing end in excess of the weight of system 100 b to achieve the blind connection of system 100 b to holder 820 b.
[0044] After the contents of the bag have been exhausted, the bag-in-box system 100 b may be removed from machinery 810 , the clip (if one is used in the application) may be removed from the groove, the box opened, the bag removed from the box, and the bag or both the box and the bag may be collapsed to a relatively small volume to be discarded or recycled.
[0045] To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” is employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. See, Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms “in” or “into” are used in the specification or the claims, it is intended to additionally mean “on” or “onto.”
[0046] While the present application illustrates various embodiments, and while these embodiments have been described in some detail, it is not the intention of the applicant to restrict or in any way limit the scope of the claimed invention to such detail. Departures may be made from such details without departing from the spirit or scope of the applicant's claimed invention. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. | A method of employing a bag-in-box container system in a dispensing machine includes placing a box in a first orientation, inserting a bag in the box, and closing the box with a portion of a dispensing end of the bag protruding through an opening in a first wall of the box. The first wall is a top surface of the box in the first orientation. The method further includes securing the portion of the dispensing end outside of the box and inverting the box to a second orientation, such that the first wall is a bottom surface of the box in the second orientation. The method also includes inserting the dispensing end of the bag into a holder of a dispensing machine. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to a fuel delivery system for a hand-held lighter of the type which employs liquid fuel, and more particularly to an inexpensive and reliable fuel delivery system for a lighter which stores its fuel as a liquid but utilizes it as a gas.
Recently, disposable hand-held lighters which utilize butane or mixtures of low molecular weight hydrocarbons as fuel have come into extensive use. These lighters have a reservoir which maintains the fuel in a liquid state under pressure and a manually operable valve, which when open, allows a flow of gaseous hydrocarbon fuel to the combustion compartment of the lighter. A conventional serrated wheel and flint provide a spark to ignite the fuel as it mixes with air in the combustion compartment.
Because the fuel is used in only very small increments, and because the lighters can be manufactured quite inexpensively, the user gets literally thousands of lights without replenishing the fuel, and it becomes economical to discard the lighter when the fuel is exhausted.
With most of these lighters, liquid fuel is vaporized at a flow-controlling pressure drop associated with the manually operable valve. The function of the orifice of the burner in these lighters is to direct the flow of gas at atmospheric pressure to the combustion compartment. Recently, improvements have been made which provide a wind-proof burner which requires a uniform flow of gaseous fuel under pressure for proper operation. In this case, the orifice itself produces the controlling pressure drop and drives a jet pump for aspiration of air for combustion. (see, for example, U.S. Pat. Nos. 3,844,707 and 3,915,623) Accordingly, there is a need for a simple and inexpensive fuel delivery system which will ensure that any fuel entering the orifice of such a burner be gaseous. Such a fuel delivery system must be simple and extremely small, made of inexpensive materials, and capable of being mass produced and easily installed in the lighters.
To accomplish these goals, the present invention utilizes a well known principle which has been employed in portable hand torches for providing a steady flow of gas from a liquid fuel reservoir. Specifically, it is known to provide a pressure reducing valve in the discharge passage leading from the fuel reservoir to the torch burner which seats against the gas pressure in the reservoir and is resiliently forced toward the seated position. This arrangement isolates the liquid fuel in the reservoir from the burner until the pressure beyond the valve combined with the valve's biasing force is insufficient to hold it in its seated position. Any liquid in the conduits therefore quickly volatilizes in the reduced pressure environment, and an even, uniform flow of gas to the burner is provided. However, the application of this principle to lighters of the type described is fraught with problems, i.e., the system must be simple, very small, and capable of manufacture and installation at a very low cost.
SUMMARY OF THE INVENTION
In general, the invention features a cigarette lighter fuel delivery system for feeding gaseous fuel to the burner of the lighter from its reservoir of volatile liquid fuel. The system comprises a fuel vaporizing chamber in the liquid fuel reservoir, one end of which communicates with the burner through a manually operable valve, the other end of which has a passage defining a valve seat for passing fuel from the reservoir to the chamber. A valve is placed in the passage which is biased to seal the passage and opens to allow fuel therethrough only when the pressure in the vaporizing chamber falls a selected amount below the pressure in the reservoir. The valve comprises an anchoring portion in contact with a wall of the chamber, a poppet for blocking the passage, and one or more resilient arms extending from the anchoring portion to the poppet for maintaining a selected biasing force on the poppet under varying conditions of temperature. In preferred embodiments, the system may also include a dip tube in communication with the passage which extends into the reservoir and a filter interposed between the passage and the manually operable valve. The vaporizing chamber is preferably generally cylindrical, and the anchoring portion of the valve may comprise a ring which frictionally engages the side walls of the cylindrical chamber. The various embodiments of the valve useful in the system of the invention are designed to be inexpensive to manufacture, yet to maintain an essentially constant biasing force on the valve poppet despite change in temperature and contact with liquid fuel.
Accordingly, it is an object of the invention to provide a fuel delivery system capable of delivering only gaseous fuel to the burner of a cigarette lighter from a reservoir of volatile liquid fuel.
Another object of the invention is to provide such a fuel delivery system which is capable of mass production, is dependable, and is inexpensive to manufacture.
Another object of the invention is to provide a valve for a fuel delivery system useful in a hand-held lighter which is capable of maintaining a substantially constant biasing pressure under conditions of use.
Other objects and features of the invention will be apparent to those skilled in the art from the following description of the preferred embodiments and from the drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a plan view of a lighter with some parts in phantom and others broken away to show the fuel delivery system of the invention;
FIGS. 2, 4, 6, and 8 show four embodiments of the valve useful in the fuel delivery system of FIG. 1 in cross-section;
FIGS. 3, 5, 7, and 9 are views of the valves of FIGS. 2, 4, 6, and 8 taken, respectively, along line 3--3 of FIG. 2, line 5--5 of FIG. 4, line 7--7 of FIG. 6, and line 9--9 of FIG. 8; and
FIG. 10 is a cross section of the resilient art of the valve of FIGS. 8 and 9.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a lighter 10 is shown which comprises a fuel reservoir 12 containing a supply of liquid fuel 74, a combustion compartment 14 fed by a burner 15, and an ignition apparatus 16 consisting of a serrated wheel 18, a flint 20, and a manually operable valve 22.
The fuel delivery system of the lighter comprises a delivery tube 24, a vaporizing chamber 28, and a valve 38. The delivery tube 24 communicates between the vaporizing chamber 28 and the burner 15, and if desired, a filter 26 may be positioned therein. The vaporizing chamber 28 comprises a generally cylindrical elongate structure, about 1/8 to 1/4 inch or smaller in diameter, having side walls 30 and an end wall 32. Both the delivery tube 24 and vaporizing chamber 28 may conveniently be made from plastic material, e.g., nylon, using well known techniques such as injection molding. End wall 32 defines a passage 34, more clearly shown in FIGS. 2, 4, 6, or 8, and a valve seat 44. Extending from the exterior of wall 32 is a dip tube 36 which may be omitted if desired. Vaporizing chamber 28 and delivery tube 24 together comprise a conduit means for communicating between the reservoir 12 and burner 15.
Referring to FIGS. 2-9, four embodiments of the valve useful in the fuel delivery system of FIG. 1 are shown. FIGS. 2 and 3 provide a detailed view of the valve 38 in its position at the bottom of vaporizing chamber 28. This valve comprises an annular anchoring portion 40 which is frictionally held in position by its contact with side walls 30 and end walls 32, a poppet 42 nested in the passage 34 on a valve seat 44, and a pair of resilient arms 46, integral with anchoring ring 40 and in contact with poppet 42, which urge the poppet 42 toward the nested position. The poppet 42 may be made of a castable rubber, e.g., one sold under the tradename Buna-N. The anchoring ring 40 and resilient arms 46 are fashioned from a resilient material, e.g., brass.
FIGS. 4-9 show three embodiments of a one piece valve which may be made from a castable rubber and used in place of valve 38.
Valve 48 of FIGS. 4 and 5 comprises an annular anchoring portion 50, an elongate poppet 52, and a pair of resilient arms 54 extending therebetween for urging the poppet 54 toward the valve seat 44. As can be seen in FIG. 4, the arms 54 extend upwardly from anchoring ring 50 and connect with poppet 52 at its uppermost extremity.
Valve 56, as seen in FIGS. 6 and 7, comprises an anchoring portion 58, a poppet 60, and a single resilient arm 62 extending therebetween. Valve 56 is held in position by the frictional fit of anchoring portion 38, reinforced by means of a pair of lips 62 which are recessed into the side wall 30 of vaporizing chamber 28.
A fourth embodiment of the valve 64, as seen in FIGS. 8 and 9, is adapted for use with an expansion chamber having a modified bottom wall 33. Valve 64 comprises an anchoring portion 66, a poppet 68, and a pair of spiral resilient arms 70. A section of a spiral arm 70 is shown in FIG. 10 to point out that the arm's axial dimension is considerably greater than its radial dimension. Valve 64 can be cast in a planar mold, and when placed in position in the bottom of a vaporizing chamber having a modified end wall 33, will be deformed to the shape shown, i.e., the middle, poppet section of the valve will be displaced axially out of the plane of attachment of the end wall 33 and side wall 30 so that the original planar configuration is deformed to a cone-like configuration. This arrangement provides an axial biasing force on the poppet 68, and may also be employed, for example, on the valve of FIGS. 4 and 5.
All four embodiments of the valve illustrated are designed to maintain a selected axial biasing pressure in the direction of closure of the poppet during varying conditions of temperature and while exposed to liquid fuel, i.e., conditions encountered during operation of the lighter of the invention. It is important that the biasing force exerted on the poppet remain substantially constant during operation of the lighter to maintain a constant pressure differential between reservoir 12 and chamber 28. For a valve seat approximately 1/16 inch in diameter and an operable pressure differential on the order of 6 p.s.i., a force close to 0.003 pound must be maintained. Some variations in this differential is tolerable, but in no event should it be greater than about 10 p.s.i. Obviously, minute variations in the biasing force exerted on the poppet can significantly change this pressure differential.
Because of the repetitive vaporizations of fuel in the vaporizing chamber 28, and because of widely varying external temperatures, the walls 30 and 32 of vaporizing chamber 28 and the materials with which the valve is constructed undergo small but significant thermal expansions and contractions during use of the lighter. Such behavior by the walls, especially wall 30, results in changes in the radially directed forces exerted on the annular anchoring portions 40, 50, 58, and 66, respectively, by the side walls. If such changes in force were allowed to be transmitted to the poppet, the axial biasing force on the poppet exerted by the arms would vary. Specifically, when during vaporization of liquid fuel, the walls of the vaporizing chamber cool and contract, the axial force exerted on a poppet by a plurality of radially directed resilient arms would vary. However, according to one important aspect of this invention, valves 38, 48, 56, and 64 are designed to minimize the effect of radial stress and to maintain the biasing force on the poppets at a more or less constant level despite shrinkage or expansion of the valve material and vaporizing chamber 28.
In valve 38, this is accomplished by providing a two part valve wherein the resilient arms 46 are not joined with poppet 42. In this circumstance, radial forces exerted on the anchoring portion 40 result in radial movement of resilient arms 46. These forces thus do not affect the downward force exerted by arms 46, but rather result in a slight repositioning of the contact points 72 bearing on the poppet 42. In the case of valve 48, the effect of expansion and contraction of the vaporizing chamber side wall 30 on anchoring ring 50 is transferred only minimally to poppet 52 because of the configuration of the resilient arm 54, i.e., the biasing force on poppet 52 supplied by the elastic extension of arms 54 is only negligibly affected by radial forces exerted on the ring 50. In the case of valve 56, the anchoring portion 58 is attached to vaporizing chamber side wall 30 by tabs 62 recessed within the wall. Since this embodiment of the valve has only a single resilient arm 62, radial forces exerted on anchoring ring 58 will not develop hoop stress in the poppet 60, but rather will merely result in slight misalignment of the poppet 60 with valve seat 44. The valve of FIGS. 6 and 7 may be modified to a construction (not shown) wherein the anchoring portion comprises a single tab recessed in the wall 30, and this configuration would also avoid hoop stress. The valve seat and poppet can be shaped to accomodate the small misalignment without seriously affecting the operation of the valve. In the case of valve 64, radial forces on the anchoring ring 66 are absorbed by the spiral resilient arm 70 and do not affect the axial force generated by the deflection of spiral arm 70 from a planar configuration. The cross-section of the spiral arm 70, as shown in FIG. 10, facilitates this behavior.
In operation, the user rotates the serrated wheel 18 and simultaneously depresses the lever of the ignition apparatus 22, which releases gaseous fuel contained in delivery tube 24 or vaporizing chamber 28 into the burner 15 and generates a spark to ignite the mixture of gas and air in the combustion compartment 14. As fuel exits from the vaporizing chamber and delivery tube, the pressure within the vaporizing chamber 28 drops. When the pressure of the vapor in the vaporizing chamber 28 and the axially directed force on the poppet together equal less than the vapor pressure of the fuel 74, the poppet is displaced axially upward and fuel enters through dip tube 36 and passage 34. If any liquid fuel enters vaporization chamber 28, it quickly volatilizes until the force exerted by the pressure in the chamber together with the biasing force on the poppet is equal to the force on the poppet exerted by the vapor pressure of the fuel or until all the liquid has been converted to a gas. This change of state is, of course, endothermic, and the walls of the chamber 28 give up heat to the liquid trapped therein until equilibrium is attained. Since vaporizing chamber 28 lies within the fuel 74, and since the chamber walls conduct heat, the temperature of the fuel in the reservoir and the temperature of the fuel within the chamber equalize.
After prolonged use of the lighter, and when enough fuel has been consumed so that the liquid level is below the vaporizing chamber 28, the dip tube, which is an optional feature of the fuel delivery system of the invention, serves to conduct fuel in the reservoir to the vaporization chamber 28 and can serve as a heat conductor to assist thermal equilibration between the fuel in the reservoir and vaporizing chamber. If preferred, the dip tube may be omitted, since, when the level of the fuel in the reservoir falls below the level of end wall 32, it is less likely that any liquid will enter through passage 34, and the thermal considerations of the system become less critical.
Those skilled in the art will appreciate that many modifications of the instant invention may be made without departing from the spirit and scope thereof. For example, it may be desirable to use an adhesive to cement the anchoring portion of the valve in place or to provide a recess in the side wall 30 of the vaporization chamber 28 to receive anchoring portions of other configurations. The ring configuration of the anchoring portion is preferred because of its ease of installation. The filter 26 is provided in delivery tube 24 as an optional feature, and doubles as a wick to absorb possible small amounts of condensed fuel formed in the vaporizing chamber resulting from severe temperature fluctuations.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. | The fuel delivery system disclosed herein operates to deliver gaseous fuel to the burner of a hand-held, liquid fueled cigarette lighter from a reservoir of volatile liquid fuel. The system employs a vaporizing chamber communicating with the burner and extending into the reservoir which defines a passage for passing fuel into the vaporizing chamber. A valve, positioned on a valve seat in the passage, comprises an anchoring portion, a poppet nested on the valve seat, and one or more resilient arms integral with the anchoring portion and extending to the poppet for urging the poppet toward the valve seat. The system isolates the pressurized liquid fuel in the reservoir until the biasing force of the valve together with the pressure in the vaporizing chamber is insufficient to hold the poppet in the closed position. Thus, a reduced pressure environment is maintained in the vaporizing chamber which ensures that all the fuel in the chamber will vaporize before passing to the burner. | 5 |
This is a Division of application Ser. No. 09/535,748 filed Mar. 27, 2000, which is a CIP of application Ser. No. 09/147,760 filed May 4, 1999, which is a 371 of PCT/EP97/04842 filed Sep. 5, 1997. The disclosure of the prior applications is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTION
The invention relates to a catalyst which consists of amorphous carbon with molecular planes that have curved surfaces and contain six-membered and non-six-membered carbon rings, optionally having at least one catalytically active, low-valency metal covalently bound thereto. The invention also relates to methods of producing the catalyst and applications thereof.
In many applications involving the use of catalytically active metals on a support system, it is of advantage if the latter is a carbon-based system. However, the use of graphitic material as support has the disadvantage that, due to the graphite's planar layering, there is only little interaction with the metals. As a result, the metal is apt to agglomerate, especially under reaction conditions and in particular at elevated temperatures. Agglomeration of the catalytically active metal means that the surface area thereof is reduced, which in turn causes a reduction in the catalytic activity of the system and thus, especially in the case of valuable metals, inadequate exploitation of the system's catalytic capacity.
In patent specification DE 43 24 693.1, the inventor has already suggested over-coming this disadvantage by using metal-fullerene intercalation compounds. These have the advantage of being defined compounds which are not only highly stable on account of their bonding strongly to the catalytically active metals, but can also be reproduced exactly. This is largely due to the fact that direct covalent bonds are formed between the carbon atoms of the fullerene molecule and a metal atom.
One disadvantage of using metal-fullerene intercalation compounds as catalysts is the fact that the supporting material is expensive. In addition, it would be beneficial if the catalytic efficacy—expressed in terms of the content of catalytically active metal or metal compound used in each case—could be enhanced further by making the metal more accessible for the components of the catalysed reaction. The object of this invention is thus to overcome the above-mentioned disadvantages of catalysts with a carbon-based support.
SUMMARY OF THE INVENTION
This object is achieved by means of a catalyst which consists of amorphous carbon with molecular planes that have curved surfaces and contain six-membered and non-six-membered carbon rings, optionally having at least one catalytically active, low-valency metal covalently bound thereto.
The invention is based on the surprising discovery that amorphous, carbon with molecular planes exhibiting curved surfaces and containing not only six-membered but also non-six-membered carbon rings are suitable as catalysts and/or as supporting material for catalytically active metals, and have especially desirable properties that result in superior catalysts. Without being bound by theory, it is assumed that this is due to the presence of curved sp 2 -hybridized carbon layers. The curvature of the layers is not due in this case to simple “rolling” or “bending” of otherwise intact graphite layers, but is due to the incorporation of non-six-membered rings in the sp 2 -hybridized carbon layers. The curvature produced thus in the carbon layers is associated with significant differences compared to the geometric and electronic structure of a planar, graphitic sp 2 -hybridized carbon layer. Besides a considerable stress-induced increase in potential energy, the π electrons are not completely delocalized within these curved areas, so that the curved carbon layers can be seen to a certain extent as conjugated double-bond systems.
Thus, the presence of non-six-membered rings in the carbon network not only introduces curvature into the surface of the materials described, but also a modulation of its electronic structure. The combined action of these two effects gives rise to the presence of anchoring sites for metal particles as well as of catalytically active sites.
When used as supporting materials for catalytically active low-valency metals, the carbon material used in the catalysts of the invention, like electron-deficient olefins, are able to form chemical bonds with transition metals in low formal oxidation states. These bonds are chemical bonds formed directly between the metal and the carbon support. They do not, as is the case with conventional carbon supports such as activated charcoal, anchor the metal atoms primarily by way of interactions with terminal heteroatom functionalities, predominantly oxygen.
The amorphous carbon contained in the catalysts of the invention consists of interlacing 6-C rings in which additional rings, mainly 5-C rings, are incorporated. The curved surfaces may be concave or convex. This structure, which is an essential feature of the amorphous carbon used in the catalyst of the invention, can be determined by physical methods, especially x-ray absorption spectroscopy (XAS), as is described by H. Werner et al., in Chem. Phys. Letters 194 (1992), 62-66. The curved areas can also be characterized by their special chemical reactivity; corresponding reaction products have been characterized by IR spectroscopy after partial oxidation of these carbon materials (M. Wohlers, A. Bauer, R. Schlögl, Microchim. Acta, submitted 1995, printing). An example of the materials suitable in the context of the invention is the product known as “Krätschmer soot”. This is a product which, during the production of fullerenes by the Krätschmer method, is left behind when the fullerenes are separated off. As described in more detail below, the amorphous carbon of the catalyst of the invention may also be obtained by methods other than the one described by Krätschmer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows CO conversion and product selectivity with a ruthenium-containing catalyst according to the invention and with ruthenium-AFS-graphite. In the lower half of FIG. 1, the gas-chromatographically determined amount of CO converted in the presence of each of the catalysts is compared at different temperatures. CO conversion is a measure of the catalytic activity of the heterogeneous systems. In the upper half of FIG. 1, the methane selectivity of the two systems is compared. The methane selectivity is given by the percentage of methane in the resulting hydrocarbon mixture, which contains, among other compounds, ethane, ethene and other aliphatics, right up to octane. This part of FIG. 1 shows clearly that at low temperatures, the catalyst of the invention produces a greater proportion of hydrocarbons with a higher molecular weight than the corresponding ruthenium-graphite catalyst does.
FIG. 2 shows, in analogy to FIG. 1, a comparison of the catalytic activities and the product selectivities of ruthenium deposited on the cathode carbon deposit, as described in the invention, and Ru-AFS-graphite It is apparent from this graph that the catalyst containing cathodic-deposited carbon and ruthenium bound thereto, while showing almost identical product selectivity to that of the graphitic reference system, shows significantly higher catalytic activity at high temperatures. The drop in the catalytic activity of the graphitic system was found to be due to agglomeration of the metal particles, which caused a reduction in the surface area of the catalytically active metal. FIG. 2 thus demonstrates that the catalysts of the invention boast better thermal stability under reaction conditions.
FIG. 3 shows that a catalyst according to the invention without a catalytically active metal, i.e., a catalyst which consists only of the amorphous carbon in accordance with the invention (TB 74) exhibits a much higher mass yield compared to natural graphite (AF-S), activated carbon (Norit A) and a technical silver catalyst (Ag) between about 670 and 720° K. This yield is obtained at a temperature which basically lies below the value commonly used in industrial practice, which contributes considerably to energy saving.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Metal particles containing 10 to 1000 atoms are able to form the covalent bonds characteristic of the catalysts of the invention. With larger metal particles, the strength of the bonds decreases. As the size of the metal particles increases, the binding strength finally decreases to a value which, for the size of the metal particles, is no longer significantly greater than the binding strengths of conventional carbon supports.
The amorphous carbon contained in the catalysts of the invention differ from fullerenes in that the reactive double bonds in the curved carbon layers are an integral component of the amorphous carbon of the invention, whereas fullerenes consist of defined, individual molecules. Among the amorphous carbon materials which are suitable for the catalysts of the invention, for example, are fullerene soot residue and the product known as “onion carbon”. It has onion-like structures with a diameter of 100 Å or more, which are embedded firmly in the surrounding carbon. Fullerenes, by contrast, have a diameter of about 10 Å, and are molecular.
Besides the aforementioned Krätschmer method, with subsequent separation of the fullerenes, there are other methods of producing the amorphous carbon materials contained in the catalyst of the invention. These include, in particular, the high frequency vaporization of graphite, laser vaporization of graphite, and the pyrolysis of hydrocarbons under suitable conditions. A preferred method of obtaining the amorphous carbon is to vaporize pure graphite in an enclosed apparatus containing at least two electrodes and having an inert atmosphere to produce a vaporized composition containing fullerene soot residue and which may also contain more-or-less fully-formed fullerenes, rapidly cool the vapor to deposit the composition on a surface of the apparatus and/or the electrodes and then remove any fullerenes contained in the composition by way of solvent extraction.
The superior catalytic properties of the metal-containing catalysts described in the invention are attributed to the fact that all the catalytically active metal is anchored at the surface and therefore very readily accessible for the components of the reaction being catalysed. In the case of the transition metal/fullerene compounds, by contrast, a significant proportion of the catalytically active metal is in the interior of the macroscopic particles of transition metal/fullerene compound, and therefore inaccessible for the components of the reaction being catalysed. The superior stability of the metal-containing catalysts of the invention compared to graphite-based catalysts is attributed to the covalent bonds formed with the metal.
Low-valency metals are understood in the context of this invention to mean metals in the avalent, monovalent and divalent states. Preference is given to metals in the avalent state, with the familiar stabilizing ligands such as carbonyls, isonitriles, phosphines, phosphites, alkenes, polyalkenes, heteroalkenes, alkines and cyclically conjugated systems such as benzene or cyclopentadienyl anions. Examples of suitable avalent, catalytically active metal complexes include triruthenium dodecacarbonyl, platinum dibenzylidene acetone, palladium dibenzylidene acetone, palladium tetrakistriethyl phosphine, nickel tetracarbonyl, iron pentacarbonyl, nonacarbonyldiiron, dodecacarbonyltriiron and so on. Some of these compounds are commercially available, while others can be prepared using standard methods, such as are described in the Handbuch der präparativen anorganischen Chemie, vol. 3, publishing house F. Encke in Stuttgart, Germany. Suitable mono- or divalent compounds include such compounds as can be reduced to the avalent state under reaction conditions, if necessary by adding a reagent that acts as reducing agent, for example, molecular hydrogen, carbon monoxide or sodium borohydride. Suitable catalytically active metals are preferably metals from groups Ib, VIIb or VIIIb of the periodic table, rare-earth metals that form low-valency compounds, or titanium or vanadium. Special preference is given to platinum, ruthenium, palladium and iron.
Other suitable metals include, eg, nickel, cobalt, manganese, osmium, iridium and rhenium, and also titanium and vanadium provided they can be reduced to the low valency state.
A particularly interesting aspect of the invention is the qualitative change which can be achieved in the catalytic properties of the bound metal. It was possible to demonstrate that the structural properties of the metal particles contained in the systems described in the invention differed markedly from those of the metals in comparable metal/graphite systems. These structural differences are attributed to qualitatively different attractive interactions between the metal particles and the carbon support system in question. The structural differences in the metal particles are not, however, exclusively of geometrical nature; it is assumed that there are also differences in the electronic structure, as a result of which the active centers at the surface of the metal, which are crucial for the heterogeneous catalysis of a reaction, exhibit different properties. For example, when the catalysts of the invention are used in the hydrogenation of carbon monoxide, one achieves a shift in selectivity to products of higher molecular weight, these being the products primarily sought after in this process.
Compared to catalysts with graphite as supporting material, the catalysts of the invention have the general advantage of retaining their stability at elevated temperatures. Besides this, they are often quantitatively superior under otherwise comparable conditions, and in other cases also exhibit qualitatively different catalytic properties.
An additional subject of the invention is a method of producing the new catalysts. According to the method of the invention, graphite is vaporized in a non-oxidizing atmosphere by means of an electric arc struck between at least two graphite electrodes in a vacuum apparatus, during which process one
a) works with a.c. or d.c. under a pressure of 100 Pa or less in a vacuum apparatus the walls of which are cooled, the product being deposited on the cooled walls, or
b) works with d.c. under a pressure of 1 to 100 kPa and arc lengths of 0.1 to 20 mm, the product accumulating on the electrode connected to the negative pole of the power supply, or
c) with a.c. under a pressure of 1 to 100 Pa and arc lengths of 0.1 to 20 mm, the product accumulating on the carbon electrodes.
Optionally, according to one embodiment of the present invention, thereafter the product of a), b) or c) may be reacted with a thermolabile, low-valency compound or complex of a catalytically active metal.
The graphite used should be as pure as possible. It is preferable to work in a noble-gas atmosphere, most preferably of helium, argon or a mixture of helium and argon. Use can also be made, e.g., of hydrogen, nitrogen or ammonia.
If the amorphous carbon is produced according to procedure a), it is expedient to cool the walls of the vacuum apparatus with water. However, other cooling methods or coolants can be used in a similar manner. For preparing the amorphous carbon it is also of advantage to work with two graphite electrodes, since this is how a commercially available apparatus is usually equipped. However, for the method of the invention it is also possible to use modified electric-arc equipment with more than two graphite electrodes.
As mentioned earlier, the amorphous carbon may also be one prepared according to the method of Krätschmer (W. Krätschmer et al., Chemical Physics Letters, vol. 170 (1990), p. 167-170), which has been freed from fully-formed fullerenes by extraction thereof.
The reaction of the amorphous carbon with the metal compound is preferably performed in the absence of air in a suspension of the supporting carbon in a solvent in which the metal compound is soluble. It is of advantage to work at an elevated temperature, preferably at the reflux temperature of the solvent. Under these conditions, the reaction is generally allowed to proceed for between 1 and 50 hours, preferably between 15 and 30 hours. If the support material contains fullerenes, these are removed prior to the reaction, preferably by extraction with a suitable organic solvent.
The general temperature range for the reaction of the amorphous carbon with the metal is between the solidification point of the solvent and its boiling point. The boiling point of the solvent can be raised according to standard practice by applying pressure; pressures up to 100 MPa, preferably up to about 10 MPa, may be used.
Suitable solvents include aromatics, halogenated aromatics, organo-chlorinated compounds and heterocyclics such as benzene, toluene, xylene, ethylbenzene, chlorobenzene, dichlorobenzene, carbon tetrachloride, chloroform, dichloromethane and tetrahydrofuran.
The catalysts of the invention are generally suitable for reactions which proceed under transition-metal catalysis. The hydrogenation of carbon monoxide is a preferred application. Other reactions for which the catalysts of the invention are especially suitable are, e.g., liquid-phase hydrogenations of organic molecules, these being conducted preferably at a temperature between the solidification point of the compound to be hydrogenated or of the solvent used and 150° C.
Furthermore, the catalysts of the invention are especially suitable for partial oxidation reactions of organic molecules. Using the catalysts of the invention, the reaction can be carried out either in the liquid phase or by passing a gaseous mixture of the reagents over the catalyst, e.g., in a fixed-bed reactor. Partial oxidations of this kind are suitable, e.g., for the oxidation of alcohols, aldehydes, alkanes and the dehydrogenation of hydrocarbons.
Liquid-phase hydrogenations of this kind are suitable, e.g., for the hydrogenation of olefins, ketones, aromatic nitro compounds and substances of comparable reactivity. These hydrogenations can be conducted directly with the substance in question (provided the compound to be reduced is liquid under the conditions of the hydrogenation reaction) or with the substance in solution. Suitable solvents in the latter case include tetrahydrofuran, dichloromethane and toluene.
The following examples serve, together with the drawings, to explain the invention in more detail.
EXAMPLES
1a. Production of the Ruthenium Catalyst
(1) In a helium atmosphere and under a pressure of 100 Pa, graphite was vaporized in an electric arc struck between two a.c.-operated graphite electrodes in a water-cooled vacuum apparatus. The desired product was deposited on the water cooled walls of the apparatus. After vaporization had been concluded and the apparatus had cooled, the product was collected and suspended in toluene. Triruthenium dodecacarbonyl Ru 3 (CO) 12 was added to this suspension at room temperature and dissolved therein. The suspension was then brought slowly to the boil, and refluxed for one day. The insoluble catalyst was then separated from the solvent, washed with solvent and dried at room temperature under vacuum. The catalyst obtained was not subjected to any additional pretreatment prior to use.
(2) In a helium atmosphere and under a pressure of 0.6 kPa, graphite was vaporized in a 1-mm electric arc struck between two d.c.-operated graphite electrodes in a vacuum apparatus. The product deposited on the cathode was removed as described in section (1), was ground and then converted into ruthenium catalyst.
1b. Hydrogenation of Carbon Monoxide
The heterogeneous hydrogenation of carbon monoxide was carried out in a fixed-bed continuous reactor under atmospheric pressure and at a temperature in the range from 200 to 300° C. As contact catalyst, use was made of a 2 cm-high pouring comprising 100 mg of catalyst obtained according to 1a.(1) and the same amount of inert glass beads. The repurified educt gases were used in a H 2 :CO ratio of 3:1 at a total flow rate of 20 ml/min. The product gases were determined by means of a gas chromatograph coupled to the synthesizing apparatus.
The procedure was repeated under the same conditions using ruthenium catalysts bound to graphite. The results are recorded in the FIGS. 1 and 2.
2a. Production of an Amorphous Carbon Catalyst
Graphite was vaporized at 400 mbar under helium atmosphere in an electric arc generated by d.c. and the product was stripped off the water-cooled walls of the apparatus after the arc was turned off. Soluble fullerenes were stripped off the amorphous carbon by extraction with refluxing toluene in a Soxhlet apparatus, subsequently removing any solvent adhering to the residue in vacuo. The amorphous carbon catalyst is termed catalyst TB74.
2b. Partial Oxidation of Methanol
The heterogeneously catalyzed oxidation of methanol to formaldehyde was carried out in a solid bed reactor at a temperature range of 200 to 450° C. The educt gases CH 3 OH and O 2 were applied at a ratio of 3:1 at a constant space velocity of 11 700 h −1 . The product gases were determined via ion molecule reaction-mass spectrometry (IMR-MS). The results are recorded in FIG. 3 . | A catalyst which consists of amorphous carbon with molecular planes that have curved surfaces and contain six-membered and non-six-membered carbon rings, optionally having at least one catalytically active, low-valency metal covalently bound thereto. Methods of producing the catalyst and applications thereof are included. | 1 |
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/689,702, filed Apr. 17, 2015 and titled Fuel Cell System and Desulfurization System, which is a division of application Ser. No. 12/837,084, filed Jul. 15, 2010 and titled Fuel Cell System and Desulfurization System, now U.S. Pat. No. 9,034,527, both of, which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to desulfurization systems and fuel cell systems with desulfurization systems.
BACKGROUND
[0003] Fuel cell systems and desulfurization systems that effectively remove or reduce sulfur content in fuel remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.
SUMMARY
[0004] One embodiment of the present invention is a unique fuel cell system. Another embodiment is a unique desulfurization system. Yet another embodiment is a method of operating a fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and desulfurization systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:
[0006] FIG. 1 schematically depicts a fuel cell system in accordance with an embodiment of the present invention.
[0007] FIG. 2 schematically depicts a desulfurization system in accordance with an embodiment of the present invention.
[0008] FIG. 3 is a plot illustrating a comparison of sulfur breakthrough results for different sulfur oxidation catalysts.
[0009] FIG. 4 is a plot comparing the performance of a platinum sulfur oxidation catalyst with synthetic natural gas and compressed pipeline natural gas feeds.
[0010] FIG. 5 is a plot comparing the performance of sulfur oxidation catalysts with a compressed natural gas feed.
[0011] FIG. 6 is a plot of average sulfur removal efficiency versus oxygen breakthrough.
DETAILED DESCRIPTION
[0012] For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the invention is intended by the illustration and description of certain embodiments of the invention. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as being within the scope of the present invention.
[0013] Referring to the drawings, and in particular FIG. 1 , a non-limiting example of a fuel cell system 10 in accordance with an embodiment of the present invention is schematically depicted. In one form, fuel cell system 10 is a mobile electrical power generation system. In other embodiments, fuel cell system 10 may be a fixed electrical power generation system.
[0014] Fuel cell system 10 includes a fuel cell stack 12 , a reformer 14 and a desulfurization system 16 . Fuel cell system 10 is configured to provide electrical power to an electrical load 18 , e.g., via electrical power lines 20 . In one form, fuel cell stack 12 is a plurality of electrochemical cells. In various embodiments, any number of electrochemical cells may be used to form fuel cell stack 12 . Each electrochemical cell includes (not shown) an anode, a cathode and an electrolyte disposed between the anode and the cathode. In one form, the electrochemical cells are in the form of solid oxide fuel cells (SOFC). In other embodiment, other types of fuel cells may be employed, such as alkali fuel cells, molten-carbonate fuel cells (MCFC), phosphoric acid fuel cells (PAFC), and proton exchange membrane (PEM) fuel cells.
[0015] Reformer 14 is in fluid communication with fuel cell stack 12 . Desulfurization system 16 is in fluid communication with reformer 14 . In one form, reformer 14 is a steam reformer. In one form, reformer 14 receives steam as a constituent of a recycled fuel cell product gas stream, and receives heat for operation from fuel cell 12 electro-chemical reactions. In other embodiments, other types of reformers may be employed in addition to or in place of a steam reformer, e.g., including but not limited to waterless partial oxidation reformers and/or auto-thermal reformers.
[0016] In one form, reformer 14 is a catalytic reactor configured to receive a fuel and an oxidant and to reform the fuel/oxidant mixture into a synthesis gas (syngas). During fuel cell system 10 operation, the syngas is supplied to the anodes of fuel cell stack 12 . In one form, the syngas produced by reformer 14 consists primarily of hydrogen (H 2 ), carbon monoxide (CO), and other reformer by-products, such as water vapor in the form of steam, and other gases, e.g., nitrogen and carbon-dioxide (CO 2 ), methane slip (CH 4 ), as well as trace amounts of higher hydrocarbon slip. In other embodiments, the syngas may have different compositions. The synthesis gas is oxidized in an electro-chemical reaction in the anodes of fuel cell stack 12 with oxygen ions received from the cathodes of fuel cell stack 12 via migration through the electrolytes of fuel cell stack 12 . The electro-chemical reaction creates water vapor and electricity in a form of free electrons on the anodes that are used to power electrical load 18 . The oxygen ions are created via a reduction of the cathode oxidant using the electrons returning from electrical load 18 into cathodes of fuel cell stack 12 .
[0017] The fuel supplied to fuel cell system 10 is a hydrocarbon fuel. In one form, the fuel is natural gas. In other embodiments, other fuels may be employed, in liquid end/or gaseous forms, in addition to or in place of natural gas. For example, in some embodiments, methane and/or liquefied petroleum gas may be employed in addition to or in place of natural gas. In one form, the oxidant employed by fuel cell 12 during operation is air. In other embodiments, other oxidants may be employed. In liquid and/or gaseous forms, in addition to or in place of air.
[0018] It is desirable to provide relatively clean fuel to reformer 14 and fuel cell stack 12 . However, some fuels include substances that have deleterious effects upon the systems that receive and/or employ the fuel. For example, in a fuel cell application, such substances may have deleterious effects on the catalyst in reformer 14 , fuel cell stack 12 , and/or other components. Some fuels, such as natural gas and compressed natural gas (CNG), as well as other hydrocarbon fuels, may contain sulfur in one or more forms, e.g., sulfur-containing compounds. Sulfur, e.g., in the form of sulfur-containing compounds, is known to damage certain systems. For example, in a fuel cell system, sulfur-containing compounds may poison the reformer 14 catalyst and/or fuel cell stack 12 , e.g., the anodes of fuel cell stack 12 . In order to reduce or prevent damage to reformer 14 and/or fuel cell stack 12 , embodiments of the present invention employ desulfurization system 16 to remove sulfur (e.g., sulfur-containing compounds) from the fuel. In other embodiments, desulfurization system 16 is employed to remove sulfur from a hydrocarbon fuel for use in other systems and processes. Various embodiments may be configured to remove all or substantially all of the sulfur-containing compounds, or to reduce the content of the sulfur-containing compounds by some amount and/or to some selected level, e.g., an amount or level commensurate. with achieving a desired downstream component catalyst life, such as reformer 14 catalyst life and/or fuel cell stack 12 life.
[0019] Desulfurization system 16 is configured to remove sulfur-containing compounds from a hydrocarbon feedstock supplied as fuel to fuel cell system 10 . In one form, desulfurization system 16 is configured to desulfurize fuel, which is supplied to reformer 14 , which is supplied to fuel cell stack 12 . In other embodiments, desulfurization system 16 may be configured to desulfurize a hydrocarbon feed for ether purposes. For example, desulfurization system 16 may be configured to desulfurize liquid hydrocarbons, e.g., such as gasoline, diesel and/or jet fuels. One of many possible methods includes, for example, vaporizing the liquid fuel, desulfurizing the vaporized fuel, and then re-liquefying the fuel for subsequent use in a hydrocarbon fueled machine.
[0020] The sulfur-containing compounds in the fuel (hydrocarbon feed) may be in one or more of many forms, including one or more organic and/or inorganic compounds. Examples of inorganic compounds that desulfurization system 16 is configured to remove include, but are not limited to, hydrogen sulfide, carbonyl sulfide and carbonyl disulfide. Examples of organic sulfur-containing compounds that desulfurization system 16 is configured to remove include, but are not limited to mercaptans, sulfides and thiophenes that may also be present in the hydrocarbon mixture being treated. The sulfur content of the fuel to be desulfurized may vary widely, e.g., in the range of 0.05 to 200 ppmV or more. Natural gas may contain, for example, 0.1 to 10 ppmV sulfur, while LPG may contain higher sulfur levels, for example, 10-170 ppmV sulfur. Other hydrocarbon feedstocks may have a sulfur content significantly above the levels mentioned herein. Various embodiments of desulfurization system 16 may be configured to reduce or eliminate sulfur from hydrocarbon feeds having a wide variety of sulfur content levels, including and beyond the levels mentioned herein.
[0021] Referring to FIG. 2 , a non-limiting example of an embodiment of desulfurization system 16 in accordance with an embodiment of the present invention is schematically depicted. Desulfurization system 16 is configured to desulfurize a hydrocarbon feedstock. By “desulfurize,” “desulfurized” and “desulfurization,” it is meant that the sulfur content in the hydrocarbon feedstock, e.g., sulfur-containing compounds, is reduced or eliminated. Desulfurization system 16 includes a catalytic reactor 22 and a sulfur oxide trap 24 . Catalytic reactor 22 includes a catalyst 26 . In one form, catalyst 26 is disposed on a carrier 25 . Carrier 28 is operative to support catalyst 26 . In other embodiments, catalyst 26 may not be disposed on a carrier or may be disposed on any convenient surface. Sulfur oxide trap 24 is configured to capture sulfur oxides from a hydrocarbon and oxidant feed that includes sulfur oxides. In one form, oxide trap 24 includes an adsorbent 30 , and is operative to trap the sulfur oxide compounds by adsorbing them with adsorbent 30 . In other embodiments, oxide trap 24 may be any device and/or system capable of trapping or capturing sulfur oxide compounds or otherwise removing sulfur oxides from a gaseous and/or liquid feed stream.
[0022] Catalyst 26 is an oxidation catalyst. Catalyst 26 is configured to oxidize sulfur, e.g., sulfur-containing compounds, to form sulfur oxide compounds, e.g., S x compounds. Examples of SO x compounds formed in catalytic reactor 22 via catalyst 26 include, but are not limited to, sulfur dioxide, sulfur trioxide and mixtures thereof.
[0023] During operation, a feed stream 32 including the hydrocarbon feedstock and an oxygen-containing oxidant is supplied to catalytic reactor 22 . In one form, the oxidant is air. In other embodiments, other oxidants may be employed in addition to or in place of air. In various embodiments, the oxidant may be in gaseous, liquid and/or solid form. In a solid form, the oxidant may be, for example, particulates entrained in a gas and/or liquid stream, or in the form of a particulate bed. The amount of oxidant added to the hydrocarbon feedstock is selected so as to provide a sufficient oxygen concentration to effect the selective oxidation of the sulfur-containing compounds to yield the sulfur oxide compounds, and to minimize the combustion of hydrocarbons.
[0024] The O 2 /C ratio in the feed stream is selected to promote oxidation of the sulfur-containing compounds, to limit the amount of hydrocarbon oxidation and combustion, and is substoichiometric. That is, the ratio of the molecular oxygen (O 2 ) relative to carbon atoms (C) in the hydrocarbon feedstock is significantly less than that required for partial oxidation or complete combustion, e.g., as shown for methane in reactions (1) and (2), respectively, below.
[0000] 2CH 4 +O 2 →2CO+4H 2 Reaction (1)
[0000] CH 4 +2O 2 →CO 2 +2H 2 O Reaction (2)
[0025] In one form, the O 2 /C ratio of feed stream 32 is in the range of about 0.001 to 0.3. In a preferred form, the O 2 /C ratio in the feed stream is in the range of about 0.001 to 0.05. In other embodiments, other O 2 /C ratios may be employed, e.g., up to 0.5. In one form, the O 2 /S ratio of the feed stream is 10 or greater. In other embodiments, other O 2 /S ratios may be employed.
[0026] In one form, feed stream 32 is pre-heated prior to its entry into catalytic reactor 22 . In other embodiments, the feed stream may be heated in catalytic reactor 22 in addition to or in place of pre-heating. In still other embodiments, the feed stream may not be heated. In one form, the hydrocarbon feedstock and oxidant are mixed prior to entry into catalytic reactor 22 . In other embodiments, the hydrocarbon feedstock and oxidant may be mixed in catalytic reactor 22 in addition to or in place of prior mixing. The mixing may be passive mixing, e.g., simply injecting oxidant into the hydrocarbon feedstock, or active mixing, e.g., employing a mechanized mixing system and/or one or more tortuous flowpaths to induce mixing.
[0027] Feed stream 32 is contacted with catalyst 26 in catalytic reactor 22 , which oxidizes sulfur-containing compounds in feed stream 32 to form sulfur oxide compounds. The amount of sulfur-containing compounds that are oxidized may vary with the application. The feed rate for the process may be provided at any suitable space velocity to achieve the desired level of sulfur removal. Space velocities for the process may vary with the application, and may range, for example, from 1,000 to 50,000/hr. In some embodiments, it may be desirable to employ a feed rate from 5000-20,000/hr. In other embodiments, other suitable feed rates may be employed.
[0028] The desulfurization process may be effectively operated at ambient or elevated pressures and at any suitable temperature. In one form, desulfurization system 16 is operated at elevated temperatures to achieve desired levels of sulfur removal, and to ensure that the hydrocarbon feed is fully vaporized under the process conditions. In other embodiments, desulfurization system 16 may be operated at lower temperatures suitable for the particular application and hydrocarbon. In one form, desulfurization system 16 operates at a process temperature in the range of 225° C. to 350° C. In some embodiments, desulfurization system 16 operates at a temperature in the range of 200° C. to 450° C. In other embodiments, desulfurization system 16 may operate at other process temperatures, e.g., in the range of about 150° C. to about 600° C. In other embodiments, desulfurization system 16 may operate at other temperatures and/or within other temperature ranges.
[0029] In order to improve the overall efficiency of fuel cell system 10 , it is desirable to operate the desulfurization system 16 at lower temperatures and O 2 /C feed ratios. Operating at lower temperatures and O 2 /C feed ratios reduces the amount of energy needed to preheat the fuel stream, and the amount of fuel that is catalytically combusted in desulfurization system 16 , respectively, relative to desulfurization systems operating at higher temperatures and O 2 /C feed ratios.
[0030] In addition, because sulfur can adversely affect the performance of the reformer and/or fuel cell, it is desirable that the process regime of desulfurization system 16 effectively remove sulfur from the hydrocarbon stream to yield a discharge feed stream having a sulfur content that permits a desired operating life for fuel cell system 10 components, including reformer 14 and fuel cell stack 12 . In one form, desulfurization system 16 is configured to remove enough sulfur to achieve levels of less than about 100-200 ppbv in the feed stream supplied to reformer 14 . In other embodiments, desulfurization system 16 may be configured to achieve greater or lesser discharge feed stream sulfur levels.
[0031] In order to reduce sulfur levels, it is desired to maintain a high combustion activity (oxidation activity) in catalytic reactor 22 . Combustion activity is a function of (among other things), the catalyst material, both the level and the type of sulfur-containing compounds that are present in the hydrocarbon feedstock, and the process temperature and pressure. One skilled in the art would be able to determine the combustion activity based on the information provided herein and other information known to those skilled in the art. The combustion activity may be varied by, among other things, adjusting the process temperature. Higher process temperatures are typically used as the sulfur level increases, and with less reactive sulfur compounds, e.g., such as thiophenes. However, higher temperatures may not be ideal for or may not be suited for certain applications, e.g., some fuel cell systems.
[0032] In order to maintain high combustion activity in a catalytic reactor, it is generally desirable to use catalysts with high combustion activity. The use of catalysts with high combustion activity facilitates operation at lower temperatures and reduces the size of the catalytic reactor relative to those systems that employ catalysts having relatively lower combustion activity. Where the desulfurization system is employed in conjunction with a fuel cell system, particularly a portable fuel cell system, which may be desirably compact, the desulfurization system, e.g., desulfurization system 16 , has a high degree of thermal and mechanical integration with the fuel cell system. Hence, it is desirable that the desulfurization system be configured, chemically, thermally and mechanically, to provide the desired desulfurization at pressures and temperatures suitable for its integration with the fuel cell system.
[0000]
TABLE 1
Hydrocarbon combustion Activity of Selected Catalyst Materials
Pt >> (Pd~CuO~Cr2O3~MnO~CoO) > NiO > Fe2O3
500
4-5
0.5
0,02
[0033] The catalytic combustion activity of various oxidation catalyst materials varies greatly. For example, as illustrated in TABLE 1, above, platinum has roughly two orders of magnitude more combustion activity than palladium and the base metal oxides of copper, chromium, cobalt and manganese; approximately three orders of magnitude more combustion activity than nickel oxide; and approximately four orders of magnitude more activity than iron oxide. Platinum containing catalysts have the highest combustion activity and consequently are particularly preferred for fuel cell and other desulfurization processes requiring high degrees of compactness and thermal and sulfur removal efficiencies. The use of platinum catalysts allows the desulfurization process to be carried out at lower temperatures than other combustion catalysts, which is particularly advantageous for fuel cell systems. However, platinum is very expensive, and hence it is desired to use only limited amounts of platinum in commercial applications, to reduce component cost.
[0034] Given that iron oxide has such a low activity, which is more than four orders of magnitude less than the activity of platinum, and which is more than two orders of magnitude less than the activity other typical potential catalysts, conventional wisdom would not consider iron oxide to be a suitable catalyst for a desulfurization unit, such as desulfurization unit 16 . Given that compactness and low temperature operation is desirable in some embodiments, including fuel cell applications and particularly portable fuel cell power plant applications, one would be even less likely to consider iron oxide as a suitable catalyst for a desulfurization unit, such as desulfurization unit 16 . However, the inventor has discovered that a catalyst that includes both iron and a Group VIII noble metal provides surprising and unexpected desulfurization results that substantially exceed the results of using the highest combustion activity catalyst, platinum, alone.
[0035] The iron (Fe) concentration in the oxidation catalyst that provides the surprising and unexpected desulfurization results may be in the range of 0.5% to 40% by weight. In some embodiments, the iron concentration in the oxidation catalyst is in the range of 1% to 30% by weight. In some embodiments, the iron concentration in the oxidation catalyst is in the range of 2% to 10% by weight. In some embodiments, the iron concentration in the oxidation catalyst is in the range of 3% to 7% by weight. In some embodiments, the iron concentration in the oxidation catalyst is in the range of 4% to 6% by weight. The iron concentrations mentioned herein do not include the weight of the oxygen in any iron oxides that form in the catalyst during processing and/or use of the catalyst. In other embodiments, other iron concentrations may be employed. The iron concentration may Vary with the needs of the particular application.
[0036] The catalyst 26 compositions suitable for use in desulfurization system 16 include at least one Group VIII noble metal and iron (Fe). Preferably the Group VIII noble metal is platinum, palladium, sodium, iridium or a combination thereof. In one form, the catalyst is supported on carrier 28 . Suitable carriers are known in the art and include refractory oxides such as silica, alumina, titania, zirconia and tungsten oxides, and mixtures thereof. Mixed refractory oxides comprising at least two cations may also be employed as carrier materials for the catalyst. In other embodiments, the catalyst may be supported on any convenient solid and/or porous surface or other structure. In still other embodiments, the catalyst may not be supported on a carrier or any other structure. In some embodiments, the catalyst also includes promoter elements to further promote sulfur oxidation. Examples of promoter elements include, but are not limited to, elements selected from Groups IIa-VIIa, Groups Ib-Vb, Lanthanide Series and Actinide Series (e.g. using the old International Union of Pure and Applied Chemistry (IUPAC) version of the periodic table).
[0037] The catalytically active noble metal, iron and optional promoter elements may be deposited on the carrier by techniques known in the art. In one form, the catalyst is deposited on the carrier by impregnation, e.g., by contacting the carrier material with a solution of the catalyst metals, followed by drying and calcining the resulting material. The catalyst may include the catalytically active noble metal in any suitable amount that achieves the desired sulfur conversion. Typically the catalyst comprises the active noble metals in the range of 0.01 to 20 wt %, preferably from 0.1 to 15 wt %, and more preferably 0.5 to 5 wt %. Promoter elements may be present in amounts ranging from 0.01 to about 10 wt % and preferably 0.1 to 5 wt %. Embodiments of the present invention may also include greater or lesser percentages of active noble metals and/or promoter elements.
[0038] In various embodiments, catalytic reactor 22 may be configured to provide any suitable reaction regime that provides contact between the catalyst and the reactants during the desulfurization process. In one form, catalytic reactor 22 is a fixed bed reactor, in which the catalyst 26 is retained within a reaction zone in a fixed arrangement. In one form, catalyst 26 and carrier 28 form catalyst pellets that are employed in the fixed bed regime, e.g., retained in position by conventional techniques. In other embodiments, other reactor types and reaction regimes may he employed, e.g., such as a fluid bed reactor, where catalyst 26 and carrier 28 form small particles fluidized by the stream of process gas.
[0039] In some embodiments, the fixed bed arrangement may take other forms, e.g., wherein catalyst 26 and carrier 28 are disposed on a monolithic structure. For example, some typical embodiments may include catalyst 26 being supported on carrier 28 and wash-coated onto the monolithic structure. Suitable monolithic structures include refractory oxide monoliths, ceramic foams and metal foams, as well as other structures formed of refractory oxides, ceramics and/or metals. A preferred type of monolithic structure is one or more monolith bodies having a plurality of finely divided flow passages extending therethrough, e.g., a honeycomb, although other types of monolithic structures may be employed. The monolithic supports may be fabricated from one or more metal oxides, for example alumina, silica-alumina, alumina-silica-titania, mullite, cordierite, zirconia, zirconia-spinel, zirconia-mullite, silicon carbide, etc. The monolith structure may have a cylindrical configuration with a plurality of parallel gas flow passages of regular polygon cross-section extending therethrough. The gas flow passages may be sized to provide from about 50 to 1500 gas flow channels per square inch. Other materials, size, shapes and flow rates may also be employed, including flow passages having greater or smaller sizes than the ranges mentioned herein. For example, a monolithic structure may be fabricated from a heat and oxidation resistant metal such as stainless steel or the like. Monolith supports may be made from such materials, e.g., by placing a flat and a corrugated sheet one over the other and rolling the stacked sheets into a tubular configuration about an axis to the corrugations to provide a cylindrical structure having a plurality of fine parallel gas flow passages. The flow passages may be sized for the particular application, e.g., from 200 to 1200 per square inch of end face area of the tubular roll. The catalytic materials may be coated onto the surface of the honeycomb by one or more of various known coating techniques.
[0040] The catalytic oxidation of sulfur compounds in feed stream 32 yields a modified feed stream 34 that contains SO x compounds. Subsequent to the catalytic oxidation of the sulfur compounds in feed stream 32 to SOx, modified feed stream 34 is supplied to oxide trap 24 to remove the sulfur oxides from the process stream. In one form, modified feed stream 34 is contacted with adsorbent 30 in oxide trap 24 , which traps and removes sulfur oxides from modified feed stream 34 to yield the output of oxide trap 24 , which is desulfurized feed stream 36 . In one form, desulfurized feed stream 36 is supplied to reformer 14 and subsequently to fuel cell stack 12 , e.g., the anode of fuel cell stack 12 . In other embodiments, desulfurized feed stream 36 may be supplied to other fuel cell system components in addition to or in place of reformer 14 and the anode of fuel cell stack 12 . In still other embodiments, desulfurized feed stream 36 may be supplied to any device or system that preferably receives a desulfurized feed stream.
[0041] Adsorbent 30 may be any adsorbent that is capable of adsorbing SOx at the desired temperature, pressure and flow conditions. In one form, adsorbent 30 is an alkali metal oxide. In other embodiments, adsorbent 30 may be any adsorbent configured to adsorb sulfur oxide compounds. Examples of materials for adsorbent 30 include, but are not limited to, alkali metal oxides, alkaline earth oxides and/or base metal (Fe, Ni, Cu, Zn) oxides. In one form, adsorbent 30 is supported on a porous material, e.g., such as alumina or silica. In one form, adsorbent 30 is in the form of pellets. In other embodiments, adsorbent 30 may take any suitable form, e.g., including one or more washcoated monolithic structures.
[0042] In examples set forth below, the inventor has shown that the sulfur breakthrough using a platinum and iron catalyst is less than half (˜42%) of that for platinum alone, which means that use of the platinum and iron catalyst provides more than twice the sulfur removal than platinum alone. The examples also illustrate that platinum used in conjunction with other Group VIII base metals that have over two orders of magnitude higher combustion activities than iron in the catalyst yields worse desulfurization results than platinum alone. For example, that the sulfur breakthrough using a platinum and iron oxide oxidation catalyst is less than half of that for platinum and manganese oxide, and approximately one quarter or less of that of catalysts formed of platinum and nickel oxide, and platinum and cobalt oxide. The examples illustrate the unexpected improvement in sulfur removal efficiency and catalyst durability that results from the addition of iron to a noble-metal containing sulfur oxidation catalyst. In the examples set forth herein, a platinum-containing sulfur oxidation (SO) catalyst (referred to herein as a Pt—SO catalyst), alone and platinum in combination with base metals, and a SO x adsorbent (DP-20, ⅙″ spheres) were used. The Pt—SO catalyst and DP-20 adsorbent were purchased from BASF Catalysts LLC (formerly Engelhard Corporation), of Islen, N.J., USA. The monolith catalyst was placed in a reactor upstream of the SO x trap. The SO x trap used in the examples effectively removes SO 2 and SO 3 from the hydrocarbon stream. It will be understood that the examples set forth are for comparative purposes only, and that embodiments of the present invention may provide greater or lesser degrees of sulfur removal, e.g., depending upon the parameters associated with the particular desulfurization system and the needs of the particular application.
[0043] The pipeline natural gas used for the testing contained approximately 93% methane, 3.08% ethane, 0.54% propane, 0.23% butanes, 0.09% pentanes, 0.14% hexane plus, 1.86% carbon dioxide, 1.23% nitrogen and 0.93 ppmV sulfur. In order to differentiate and demonstrate the superior performance of the sulfur oxidation catalysts of this invention, the sulfur content of the pipeline natural gas in Examples 1-6, was increased to about 8 ppmV by blending (spiking) it with 2020 ppmV methyl mercaptan in nitrogen.
[0044] Comparative Example 1 (noble metal only). Example 1 illustrates the performance of a Pt—SO catalyst which employs platinum as the only active metal. “Spiked” pipeline natural gas, containing about 8 ppmv sulfur, was blended with air at the catalytic reactor inlet such that the oxygen to carbon feed ratio was 0.01. The mixture of the hydrocarbon feed and air was passed over the Pt—SO catalyst at approximately 7 psig pressure, 300° C. inlet temperature and 20,000/hr space velocity. A total sulfur analyzer was used to analyze the reactor inlet and outlet gas compositions. The average sulfur content of the gas exiting the reactor was 367 ppbV.
[0045] Comparative Example 2 (noble metal plus nickel). Example 2 illustrates the effect of adding nickel to the Pt—SO catalyst formulation. The platinum-nickel SO catalyst was prepared as follows: a Pt—SO catalyst was impregnated with an aqueous nickel nitrate solution (nickel concentration=12.5 w/v-%). After removing the excess liquid, the catalyst was dried at 125 C, calcined at 400° C. and tested as in Example 1.
[0046] The average sulfur content of the gas exiting the reactor was 652 ppbV. The platinum-nickel SO catalyst was therefore less effective than the Pt—SO catalyst for sulfur removal, since the sulfur breakthrough was substantially greater using the platinum-nickel SO catalyst than the sulfur breakthrough using the Pt—SO catalyst.
[0047] Comparative Example 3 (noble metal plus cobalt). Example 3 illustrates the effect of adding cobalt to the Pt—SO catalyst formulation. The platinum-cobalt SO catalyst was prepared as follows: a Pt—SO catalyst was impregnated with an aqueous cobalt nitrate solution (cobalt concentration=12.5 w/v-%). After removing the excess liquid, the catalyst was dried at 130° C., calcined at 400° C. and tested as in Example 1. The average sulfur content of the gas exiting the reactor was 557 ppbV. The platinum-cobalt SO catalyst was therefore less effective than the Pt—SO catalyst for sulfur removal, since the sulfur breakthrough was substantially greater using the platinum-cobalt SO catalyst than the sulfur breakthrough using the Pt—SO catalyst.
[0048] Comparative Example 4 (noble metal plus manganese). Example 4 illustrates the effect of adding manganese to the Pt—SO catalyst formulation. The platinum-manganese catalyst was prepared as follows: a Pt—SO catalyst was impregnated with art aqueous manganese nitrate solution (manganese concentration=12.6 w/v-%). After removing the excess liquid, the catalyst was dried at 130° C., calcined at 400° C. and tested as in Example 1, The average sulfur content of the gas exiting the reactor was 397 ppbV. The platinum-manganese SO catalyst was therefore slightly worse than, but roughly comparable to the platinum-only (Pt—SO) catalyst, since the sulfur breakthrough was greater using the platinum-manganese SO catalyst than the sulfur breakthrough using the Pt—SO catalyst.
[0049] Example 5 (noble metal plus iron). Example 5 illustrates the enhanced SO catalyst performance that results from the addition of iron to the Pt—SO catalyst formulation. The platinum-iron SO catalyst was prepared as follows: a Pt—SO catalyst impregnated with an aqueous ferric nitrate solution (iron concentration=10 w/v-%). After removing the excess liquid, the catalyst was dried at 130° C., calcined at 400° C. and tested as in Example 1. The average sulfur content of the gas exiting the reactor was 154 ppbV, The platinum-iron SCSO catalyst thus showed significantly improved performance relative to the Pt—SO catalyst and the platinum plus other base-metal SO catalysts, since the sulfur breakthrough was substantially lower using the platinum-iron SO catalyst than the sulfur breakthrough using the Pt—SO catalyst and the platinum plus other base-metal SO catalysts.
[0050] Table I, below, summarizes the results of the SO catalyst evaluations detailed in Examples 1-5, and highlights the unexpected performance advantage of the platinum-iron catalyst. The addition of iron to the base platinum catalyst resulted in an almost 60% reduction in the level of sulfur breakthrough. In contrast, the other two Group VIII base-metals (cobalt and nickel) had a negative effect on SO catalyst performance, while the Group VIIa metal, manganese, had only limited negative effect.
[0000]
TABLE 1
Sulfur Oxidation Catalyst Performance at 300° C.
Example
Catalyst
S out (ppbv)
1
Pt
367
2
Pt + Ni
652
3
Pt + Co
557
4
Pt + Mn
397
5
Pt + Fe
154
[0051] Example 6 (relative catalyst performance at different temperatures). The performance of the SO catalysts used in Examples 1-5 were further evaluated at catalytic reactor inlet temperatures of 325° C. and 350° C. with an O 2 to carbon feed ratio of 0.01 and space velocity of 20,000/hr. FIG. 3 illustrates a plot P 1 comparing the sulfur breakthrough results for the SO catalysts of Examples 1-5 over the 300° C.-350° C. temperature range. Curve 40 represents the platinum-only SO catalyst; curve 42 represents the platinum-nickel SO catalyst; curve 44 represents the platinum-cobalt SO catalyst; curve 46 represents the platinum-manganese SO catalyst; and curve 48 represents the platinum-iron SO catalyst. The superior performance of the platinum-iron catalyst in terms of sulfur removal is an unexpected advantageous property of the platinum-iron catalyst in terms of sulfur oxidation, and hence sulfur removal, in particular, given the known relatively low hydrocarbon combustion activity of iron. In addition, the fact that the sulfur removal was significant over the 300° C.-350° C. temperature range, a relatively low temperature range, further demonstrates the unexpected advantageous property of the platinum-iron catalyst in terms of sulfur oxidation, and hence sulfur removal, given the known low activity of iron. The platinum-only, platinum-cobalt, platinum-nickel and platinum-manganese catalysts had sulfur exit levels in the 140-226 ppbV range at 325° C. inlet temperature. In contrast, the platinum-iron catalyst had no sulfur breakthrough at an inlet temperature of 325° C., which is surprisingly greater than expected desulfurization result.
[0052] Example 7 (effect of natural gas impurities on SO catalyst performance). Referring to FIG. 4 , the performance of the Pt-only SO catalyst on synthetic natural gas (SNG—approximately 96 v-% methane and 4 v-% ethane) and compressed pipeline natural gas (CNG) feeds at an inlet feed temperature of 225° C., oxygen-to-carbon feed ratio of 0.02, GHSV-20,000 h −1 and pressure of 120 psia is compared in a plot P 2 . The CNG and SNG feeds both contained about 1 ppm sulfur. FIG. 4 illustrates the reactor skin temperature at the mid-point of the SO catalyst bed as a function of time-on stream for both the CNG and SNG feed streams (curves 50 and 62 , respectively), and also illustrates the feed stream temperature measured at the inlet to the catalytic reactor (curve 54 ). The “mid-skin” temperature (curves 50 and 62 ) is directly related to the combustion activity of the catalyst. A reduction in temperature over the course of time indicates a loss of catalyst combustion activity. FIG. 4 illustrates that the catalyst performance is adversely affected by impurities in the CNG at elevated pressure With an inlet temperature of 225° C. No performance decline was observed with synthetic natural gas.
[0053] Referring to FIG. 6 , the performance Of the Pt—SO catalyst (curve 60 ) and platinum-iron SO catalyst (curve 62 ), under the same conditions with a CNG feed, are compared in a plot P 3 . The platinum-iron SO catalyst was more robust, with its performance being only slightly affected by the impurities in the CNG.
[0054] Example 8 (Sulfur removal efficiency and oxygen breakthrough). Referring to FIG. 6 , a composite plot of average sulfur removal efficiency versus oxygen breakthrough for Examples 1-6 is illustrated via curve 64 . Oxygen breakthrough is a measure of combustion activity; the higher the combustion activity, the lower the oxygen breakthrough. FIG. 6 illustrates that sulfur removal efficiency increases with increasing catalyst combustion activity, which illustrates the heretofore conventional wisdom that catalysts with high combustion activity are required for effective sulfur removal. however, as set forth herein, the addition of iron (a low combustion activity material) to the platinum catalyst substantially increases sulfur removal efficiency.
[0055] It has been surprisingly found that the addition of iron (a metal with relatively low combustion activity) to a combustion catalyst comprising a Group VIII noble metal significantly improves the combustion activity, sulfur removal efficiency and durability of the catalyst. When ether more active base metal oxides were added to a platinum containing SO catalyst in place of iron, no improvement in combustion activity or sulfur removal efficiency was observed. The addition of iron to the catalyst formulation has very little impact, if any, on catalyst cost. However, the addition of iron to the catalyst formulation improves the process economics by allowing more efficient operation, lower temperature operation, and reduced maintenance requirements (longer periods of operation before catalyst change-outs are required).
[0056] Embodiments of the present invention include desulfurization by contacting a gaseous feed mixture of the hydrocarbon gas and a gas containing molecular oxygen with a catalyst at a temperature of at most 500° C., the catalyst comprising a Group VIII noble metal or a combination thereof and iron, supported on a catalyst carrier, wherein the feed mixture has an oxygen-to-carbon (O 2 /C) mole ratio within the range of about 0.005 to 0.03, and then contacting the hydrocarbon gas mixture with an adsorbent capable of adsorbing sulfur oxides (SOx), wherein at least a portion of the SOx is adsorbed on the adsorbent.
[0057] Embodiments of the present invention include a fuel cell system, comprising: a fuel cell; a catalytic reactor having a sulfur oxidation catalyst including at least one Group VIII noble metal and iron; wherein the catalytic reactor is configured to contact a sulfur-containing hydrocarbon fuel and an oxidant with the sulfur oxidation catalyst; wherein the sulfur oxidation catalyst is configured to oxidize sulfur-containing compounds to form sulfur oxides; and wherein the iron concentration in the catalyst is in the range of 0.5% to 40% by weight; and an adsorbent fluidly disposed between the catalytic reactor and the fuel cell, wherein the adsorbent is configured to adsorb the sulfur oxides, wherein the catalytic reactor and the adsorbent are operative to remove sulfur-containing compounds from the sulfur-containing hydrocarbon fuel prior to supplying the hydrocarbon fuel to the fuel cell.
[0058] In a refinement, the iron concentration in the sulfur oxidation catalyst is in the range of 1% to 30% by weight.
[0059] In another refinement, the iron concentration in the sulfur oxidation catalyst is in the range of 2% to 10% by weight.
[0060] In yet another refinement, the iron concentration in the sulfur oxidation catalyst is in the range of 3% to 7% by weight.
[0061] In still another refinement, the iron concentration in the sulfur oxidation catalyst is in the range of 4% to 6% by weight.
[0062] In yet still another refinement, the at least one Group VIII noble metal concentration in the sulfur oxidation catalyst is in the range of 0.01% to 20% by weight.
[0063] In a further refinement, the at least one Group VIII noble metal is platinum.
[0064] In a still further refinement, the fuel cell system further comprises a reformer, wherein the adsorbent is fluidly disposed between the catalytic reactor and the reformer.
[0065] Embodiments of the present invention include a desulfurization system, comprising: a catalytic reactor operative to oxidize sulfur-containing compounds in a feed stream having a sulfur-containing hydrocarbon fuel and an oxidant, wherein the catalytic reactor includes a catalyst including platinum as a first active metal and iron as a second active metal; wherein the iron concentration in the sulfur oxidation catalyst is in the range of 0.5% to 40% by weight; and wherein the sulfur oxidation catalyst is configured to oxidize sulfur-containing compounds to form sulfur oxides; and a sulfur oxide trap disposed between the catalytic reactor and the fuel cell, wherein the sulfur oxide trap is configured to capture sulfur oxides from the feed stream.
[0066] In a refinement, the desulfurization system is configured to desulfurize a feed stream having an O 2 /C ratio of about 0.001 to 0.3.
[0067] In another refinement, the desulfurization system is configured to desulfurize a feed stream having an O 2 /C ratio of about 0.001 to 0.05.
[0068] In yet another refinement, the desulfurization system is configured to desulfurize a feed stream having an O 2 /S ratio of at least 10.
[0069] In a further refinement, the catalyst further includes promoter elements configured to promote sulfur oxidation.
[0070] In a yet further refinement, the promoter elements include at least one element selected from Groups IIa-VIIa, Groups Ib-Vb, Lanthanide Series and Actinide Series.
[0071] Embodiments of the present invention include a desulfurization system, comprising: a catalytic reactor operative to oxidize sulfur-containing compounds in a feed stream having a sulfur-containing hydrocarbon fuel and an oxidant, wherein the catalytic reactor includes a catalyst including platinum as a first active metal and iron as a second active metal; and wherein the sulfur oxidation catalyst is configured to oxidize sulfur-containing compounds to form sulfur oxides; and a sulfur oxide trap disposed between the catalytic reactor and the fuel cell, wherein the sulfur oxide trap is configured to capture sulfur oxides from the feed stream, wherein an iron concentration in the sulfur oxidation catalyst is selected to provide greater desulfurization of the sulfur containing hydrocarbon fuel than that provided by catalysts having platinum as the only active metal and catalysts having platinum and other base metals as the active metals.
[0072] In a refinement, the iron concentration is selected to yield at least fifty percent less sulfur breakthrough downstream of the sulfur oxide trap than catalysts having platinum as the only active metal and catalysts having platinum and other base metals as the active metals.
[0073] Embodiments of the present invention include a method of operating a fuel cell system, comprising: providing a catalytic reactor having a sulfur oxidation catalyst including at least one Group VIII noble metal and iron; wherein the catalytic reactor is configured to contact a sulfur-containing hydrocarbon fuel and an oxidant with the sulfur oxidation catalyst; wherein the sulfur oxidation catalyst is configured to oxidize sulfur-containing compounds to form sulfur oxides; and wherein the iron concentration in the catalyst is in the range of 0.5% to 40% by weight; and providing a sulfur oxide trap configured to capture sulfur oxides; supplying the sulfur-containing hydrocarbon fuel and the oxidant to the catalytic reactor; contacting the sulfur-containing hydrocarbon fuel and the oxidant with the sulfur oxidation catalyst; oxidizing sulfur-containing compounds in the hydrocarbon fuel using the oxidant and the sulfur oxidation catalyst; capturing sulfur oxides using the sulfur oxide trap; and providing desulfurized fuel to a component of the fuel cell system.
[0074] In a refinement, the method further comprises providing an adsorbent configured to adsorb the sulfur oxides.
[0075] In another refinement, the component is a reformer.
[0076] In yet another refinement, the at least one Group VIII noble metal is platinum.
[0077] 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 embodiment(s), 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 permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary. | One embodiment of the present invention is a unique fuel cell system. Another embodiment is a unique desulfurization system. Yet another embodiment is a method of operating a fuel cell system. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for fuel cell systems and desulfurization systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith. | 7 |
This is a Continuation of application Ser. No. 08/060,565, filed May 12, 1993, now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to a series-shed loom including a rotor having reeds which comb through the warp threads. The warp threads are inserted by laying elements in shedding high and low points of guide elements in the direction of rotation right up to a beater bar. The laying elements are spaced apart from the reeds.
From EP 0 456 599 is known a series-shed loom having a shedding rotor, into which picks are inserted. The rotor is covered with shedding guide elements and with reeds, into which laying elements lay in warp threads by displacement at right angles to the direction of rotation. During shedding the majority of warp threads experience an excursion at right angles to the direction of rotation, which is not stopped until the removal of the guide elements before the beat up, so that the warp threads are newly straightened. The warp threads partially overlap adjacent the rotor. During the laying-in of the warp threads by the reverse movement of the laying elements there is the danger that two crossing warp threads touch at a point of intersection and are obstructed by the mutual friction, with the result that the two warp threads no longer extend in the stretched condition but at the point of contact have an additional bending point and are therefore no longer in the planned position. Another danger is that the warp threads are not inserted as planned into the shedding high and low points of the rotor and/or that the warp threads can not be combed out as planned and therefore skip the reed. Errors are produced in the fabric because of the warp threads not being inserted in the rotor in the way planned. Furthermore, during the laying-in operation there is the danger that the warp threads, which can be moved by laying elements at right angles to the direction of rotation, are laid in the guide elements as planned and are guided by the guide elements in the transverse direction, but that further transverse movements of the warp threads under some circumstances cause a slanting-off so that the warp threads can not be combed out and therefore skip the reed.
SUMMARY OF THE INVENTION
The invention offers a remedy to these problems. The object of the invention is to avoid trouble during the laying-in operation of the warp threads into the shedding high and low points of the guide elements, which is caused by contact between crossing warp threads or by warp threads skipping over the reed. The object is achieved according to the invention forwardly displacing a point of intersection of adjacent warp threads in a fabric. The point of intersection is forwardly displaced by providing a minimum pitch between the laying elements or by assigning adjacent warp threads to laying elements in an appropriate manner so that the minimum pitch is provided which cross directly in front of the reeds being inserted, have a point of intersection forwardly displaced in the direction of rotation; and means for ensuring, for a warp repeat, that the laying elements of the adjacent warp threads have a minimum pitch by assigning of the warp threads to the laying elements in a manner which provides said minimum pitch or by increasing a spacing between the laying elements.
The advantages of the invention are regarded as being that, apart from a reduction in fabric errors, fabrics with smaller warp thread spacings or higher number of threads in the warp can also be produced, and that warp threads experience less stress and thus even threads having a greater surface roughness, e.g. threads made from staple fibre material, can be processed. The fact that the area of the angle of rotation of the rotor, inside which the warp threads could again jump out of the guide elements because of slanting-off, is reduced also has an advantageous effect. Therefore between two guide elements a larger area for the angle of rotation is produced, inside which the laying elements can move the warp threads in the transverse direction without the risk of skipping.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a shows a section through a loom rotor and associated laying elements, in which the warp threads between two consecutive guide elements form an intersection point directly in front of an inserted reed;
FIG. 1b shows a perspective view of the guide elements and of the crossing warp threads;
FIG. 1c shows a top view of the rotor and also the path of the crossing warp threads;
FIG. 2 shows a section according to FIG. 1a, in which intersection points displaced forwardly with the laying elements are formed in front of an inserted reed;
FIG. 3 shows the spacings of the laying elements in the direction of rotation with a 2 thread repeat and forwardly displaced intersection points;
FIG. 4 shows the spacings of the laying elements in the direction of rotation with a 4 thread repeat and forwardly displaced intersection points;
FIG. 5 shows the spacings of the laying elements in the direction of rotation with a 6 thread repeat and forwardly displaced intersection points;
FIG. 6 shows the arrangement of laying elements and warp threads at the edge of a fabric in order to form a list; and
FIG. 7 shows a list with half twist.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1a a rotor 7 is covered with shedding guide elements 22 in the circumferential direction. The reeds 8 may also be used to beat-up the picks 10 at a fabric knock-off, depending on the design of the guide elements 22. The guide elements 22 also comprise high guides 11 and low guides 12, into which one warp thread or several warp threads is/are laid in by the laying elements 14. In the guide element 22 there is also integrated a pick channel 9, through which the pick 10 can be inserted into the shed 13 between the warp threads 1-6 kept open by the high guide 11 and the low guide 12.
The reed spacing angle α, which also corresponds to the spacing angle of the guide elements 22, is an integral fraction of 360°, i.e. 30°. To insert several picks 10 simultaneously, several sheds 13 are formed by guide elements 22. The laying elements 14 are disposed on the periphery with a spacing in the order of magnitude of several reed spacing angles α starting from the knock-off in the direction opposite to the direction of rotation 15 of the rotor 7.
The individual laying elements 14 are disposed parallel to the axis of the rotor 7 by a mutual spacing 23 in the direction of rotation 15 of the rotor 7, the laying elements 14 having a width 18. If the guide element 22 is also used as a reed or if separate reeds without shedding high and low points are provided between the guide elements 22, in the direction of the axis of the rotor 7 or in the direction of rotation 15, the distance 21 from the laying elements 14 to the highest point of the reeds 8 normally lies within a range of up to and is preferably less than 10 mm. The laying elements 14 are normally disposed along a segment of a circle, the radial center of which corresponds to the center of rotation of the rotor 7. The laying elements 14 may lie parallel to the axis of rotation of the rotor 7 in surfaces formed in a different way, e.g. a surface having a different radial center, or in a plane in which the laying elements 14 are disposed one behind the other.
The laying elements 14 consist of bars with guide holes or with notches having a spacing of integral multiples of the warp thread repeat. A laying element 14, e.g. having warp threads 1, 1', 1", etc is controlled at right angles to the direction of rotation 15 of the rotor 7 according to a program and the warp threads are laid into holes provided for insertion in guide element 22, in coordination with the rotation of the rotor 7. In the present example the laying elements 14 lay their warp threads alternately into high guides 11 and low guides 12, so that sheds 13 are formed.
The guide elements 22 having reeds 8, high guides 11 and low guides 12, which rotate past the laying elements 14, run into the warp threads 1-6, 1'-6', etc supplied tangentially by the laying elements 14 and comb these threads through in the direction of rotation 15 until they are abandoned by the warp threads in the direction of the fabric knock-off. During the insertion of the guide elements 22 into the warp threads 1-6, 1'-6', etc. the reeds 8 have the task of guiding the warp threads so that the warp threads come to lie in the high and low guides provided.
During the insertion of the warp threads, two warp threads, e.g. the adjacent warp threads 1 and 2 in FIG. 1b, form a point of intersection 16 by mutual contact. The warp threads 1, 2 normally inserted in the stretched condition between guide element 22 and laying element 14 into the rotor 7 have an additional bending point at the point of intersection 16, which hinders the freedom of movement of the warp threads 1 and 2, in particular in the direction of movement 14a of the laying elements 14. The freedom of movement of the warp threads is restricted thereby, in a manner which partly could not be foreseen, as a result of which there is the danger that the warp threads do not come to lie in the high and low guides provided.
FIG. 1c shows the same situation as FIG. 1b in a top view of the rotor 7. The warp threads 1 and 2, which touch one another, may have an additional bending point at the point of intersection 16, which is more or less marked, depending on the mutual friction. If the warp threads did not touch one another, they would lie as shown in position 1a, shown by broken lines, and an intersection point 16a would be produced.
With the point of intersection 16, the freedom of movement of the warp threads 1 and 2 in the direction of movement 14a of the laying components 14 is considerably restricted in comparison with point of intersection 16a. The guide points provided for the warp threads 1 and 2 are the laying elements 14 and also the guide element 22, into the high and low guides 11, 12 of which the warp threads 1 and 2 have already been inserted. The excursion of any sections of the warp threads 1 and 2 between guide element 22 and laying element 14 in direction 14a is calculated according to geometric principles. By intersection point 16 the freely moveable length of the warp threads 1 and 2 with respect to laying element 14 in direction 14a is reduced. The closer a touching intersection point 16, in relation to the free length of movement of the warp threads 1 and 2 between guide element 22 and laying element 14, comes to lie against the laying element 14, the more pronounced is the deviation of the actual position of the warp threads 1 and 2 from the desired position 1a, 2a. In particular with a high number of threads in the warp, there is the danger that warp threads which touch one another and obstruct one another are not inserted into the guide element 22 as planned. As seen in FIG. 1c, if the mutual contact of adjacent warp threads at a point of intersection 16 cannot be prevented, a positive effect on the freedom of movement in the direction 14a is attained if the point of intersection 16 between laying element 14 and guide element 22 is moved as close as possible to the guide element 22.
There is also the danger that the two warp threads 1 and 2 rub against one another at contact point 16 and such frictional forces are produced that the warp threads 1 and 2 can not be combed out, but are raised from the edge 8a of the reed 8 acting on intersection point 16, and intersection point 16 slips over the highest point of the reed 8 into the following space between two guide elements 22. The warp threads 1 and 2 are thus incorrectly inserted into the high and low guide.
From FIG. 1a can be seen a further problem of crossing warp threads. The warp thread 4 lies at the high point 11 of guide element 22. The warp thread 5 would lie in position 5a shown by broken lines in the absence of inserted guide element 22a and would therefore not cross the warp thread 4 between laying element 14 and guide element 22. The guide element 22a dipping into the warp threads 1-6 raises the warp thread 5 and between warp threads 4 and 5 produces two additional intersection points 16b and 16c, in which however no mutual contact should take place under any circumstances. Intersection point 16c in particular lies close to laying components 14, and as a result because of the reverse movement there is the danger that the two warp threads 4 and 5 can touch during laying-in at intersection point 16c and can therefore hinder one another.
In comparison with FIG. 1a the warp threads 1-6, which lie next to one another in ascending numbering at right angles to the direction of rotation 15, are distributed differently over the laying element 14 in FIG. 2. The warp thread 2 lying next to the warp thread 1 in the fabric 20 to be produced is inserted into the guide element 22 by a laying element 14 offset by at least one further spacing 23 in the direction opposite to direction of rotation 15 in comparison with FIG. 1a. In other words, the warp threads 1 and 2 are engaged by laying elements which are spaced apart by at least one additional laying element, and preferably by more than one additional laying element so that, starting from the point of intersection 16, there is produced a forwardly displaced point of intersection 17a, which can be seen in FIG. 2. The remaining warp threads 4-6 also have forwardly displaced points of intersection 17. The properties of a forwardly displaced point of intersection 17 are briefly illustrated by means of the warp threads 1 and 2. The piece of thread 1b lying between laying element 14 and the forwardly displaced point of intersection 17a is relatively long when compared with FIG. 1a with point of intersection 16, whereas the piece of thread 1a lying between point of intersection 17a and the following guide element 22 is relatively short. According to geometric principle this arrangement, with warp threads 1 and 2 which did not originally touch, permits a greater excursion 14a of the laying elements 14, until the warp threads 1 and 2 touch. A forwardly displaced point of intersection 17a influences the deviation of the warp threads from the specified position less strongly than a point of intersection 16 when there is mutual contact between the warp threads 1 and 2.
With an inserted guide element 22a there is the danger, as already mentioned, that a touching point of intersection 16 can not be combed out and skips the reed 8. A forwardly displaced intersection point 17 reduces the angle of rotation of the rotor, which is required to lay the respective warp threads completely in the high and low guides of guide elements 22. Furthermore a forwardly displaced intersection point 17 normally lies lower down between the inserted guide element 22a and the advancing guide element 22, or alternatively closer to the surface of the loom rotor 7. The inserted reed 8 may therefore dip further into the warp threads 1-6, until it encounters a forwardly displaced intersection point 17, which possibly exists. Therefore a greater force is required to raise an intersection point 17 along edge 8a of a reed 8 over the highest point of the reed. The risk of a reed 8 being skipped is therefore reduced and therefore yarn with a rougher surface can also be safely combed out.
In FIG. 3 is shown an arrangement of the laying elements 14 and also of the warp threads 1-2, 1'-2', 1"--etc accordingly influenced thereby for a basket weave. For this type of weave forwardly displaced intersection points 17, for example, can be produced with an arrangement as shown in FIG. 3 The warp threads 1-2, 1'-2', 1"-etc. lie in two laying elements 14, the laying elements being spaced by at least one minimum pitch 19. The minimum pitch 19 is selected so that, for example, it corresponds to at least twice the width 18 of a laying element 14 in the direction of rotation 15. The forwardly displaced point of intersection 17 may of course be further forwardly displaced by the insertion of guide element 22 in the direction of rotation 15, by the spacing between the two laying elements 14 being increased beyond the minimum pitch 19. As a result the distance from the intersection point 17 to the surface of the rotor 7 is also by necessity reduced.
FIG. 4 shows an arrangement of the laying elements 14 and the associated warp threads 1-4, 1'-4', etc for a warp thread repeat of 4 threads. With this arrangement the laying elements 14 can be disposed extremely compactly in direction of rotation 15 so that two warp threads adjacent in the fabric 20 have a forwardly displaced intersection point 17 with a minimum pitch 19.
FIG. 5 shows an arrangement of the laying elements 14 and the associated warp threads 1-6, 1'-6', etc for a warp thread repeat of 6 threads. With this arrangement the laying elements 14 can be disposed next to one another in an extremely compact and space-saving manner in the direction of rotation 15 so that two warp threads adjacent in the fabric 20 lie on laying elements having a spacing of at least one minimum pitch 19, and because of this the warp threads have a forwardly displaced intersection point 17.
Of course forwardly displaced intersection points 17 may also be achieved in that the laying elements 14 have the same appropriate spacing in the direction of rotation. FIG. 3 to FIG. 5 show advantageous arrangements of laying elements 14 and warp threads which enable, with forwardly displaced intersection points 17, all the laying elements to be disposed in an angular region which is as small as possible with respect to the direction of rotation 15 of the loom rotor 7.
The edge of a fabric is normally designed as a list, whereby the list has a weave which is different when compared to the remaining fabric. For a warp repeat of six threads FIG. 6 shows an arrangement of the laying elements 14 and the associated warp threads 1-6, 1'-5' and also the associated selvedge warp threads K1, K2, K3.
Each selvedge warp thread K1, K2, K3 lies separately on a laying element 14, so that the selvedge warp threads K1, K2, K3 can be moved independently of the other warp threads 1-6. All adjacent warp threads, including the selvedge warp threads, have a minimum pitch 19, for which reason the warp threads 1-6, K1, K2, K3 have forwardly displaced intersection points 17.
FIG. 7 shows an example of a list, consisting of three warp threads K1, K2, K3, whereby these are inserted into the guide elements 22 in such a way that a list, consisting of crossing threads K1, K3 and a stationary thread K2, is formed. | A series-shed loom for weaving a fabric from warp threads and weft threads. The loom has a rotor with reeds that comb through the warp threads and carries guide elements which define high points and low points. A multiplicity of elongated laying elements oriented parallel to the axis of rotation of the rotor guide the warp threads towards the rotor and insert them in the high and low points of the guide elements thereon. The laying elements are spaced from the rotor surface, they have a width in the direction of rotation, and warp threads which are adjacent in the fabric are guided over laying elements which are separated from each other by a pitch of at least twice the pitch between adjacent laying elements so that a point of intersection between the warp threads which are adjacent in the fabric is moved relatively further away from the laying elements and so that the point of intersection is further moved closer towards the rotor. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the filing benefit under 35 U.S.C. §119(e) of provisional U.S. Patent Application Ser. No. 61/197,074 filed on Oct. 23, 2008, as well as International Patent Application No. PCT/US09/61737, both of which are incorporated herein in their entirety.
FIELD OF INVENTION
The present invention relates to an apparatus for an epicyclic joint. More specifically, the present invention provides a wide angle, constant power, multi-axis joint with epicyclic gearing.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
No federal funds were used to develop or create the invention disclosed and described in the patent application.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
Not Applicable
AUTHORIZATION PURSUANT TO 37 C.F.R. §1.72(d)
A portion of the disclosure of this patent document contains material which is subject to copyright and trademark protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyrights whatsoever.
BRIEF DESCRIPTION OF THE FIGURES
In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limited of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings.
FIG. 1 provides a perspective view of one embodiment of a multi-axis epicyclic joint not rotated about either axis of rotation.
FIG. 2 provides another perspective view of one embodiment of a multi-axis epicyclic joint at an extreme position about the first axis of rotation and not rotated about the second axis of rotation.
FIG. 3 provides another perspective view of one embodiment of a multi-axis epicyclic joint not rotated about the first axis of rotation and at an extreme position about the second axis of rotation.
FIG. 4 provides another perspective view of one embodiment of a multi-axis epicyclic joint at an extreme position about the first axis of rotation and an extreme position about the second axis of rotation.
FIG. 5A provides a perspective view of one embodiment of a multi-axis epicyclic joint at an intermediate position about the first axis of rotation and an intermediate position about the second axis of rotation.
FIG. 5B provides another perspective view of one embodiment of a multi-axis epicyclic joint at an intermediate position about the first axis of rotation and an intermediate position about the second axis of rotation.
FIG. 6A provides a detailed view of one embodiment of a center frame that may be used with a multi-axis epicyclic joint.
FIG. 6B provides a partial exploded view of one embodiment of a center frame that may be used with a multi-axis epicyclic joint.
FIG. 7A provides an end view of one embodiment of a planetary gear head that may be used with a multi-axis epicyclic joint.
FIG. 7B provides a perspective view of one embodiment of a planetary gear head that may be used with a multi-axis epicyclic joint.
DETAILED DESCRIPTION
Listing of Elements
ELEMENT DESCRIPTION
ELEMENT #
Epicyclic joint
10
First axis of rotation
12
Second axis of rotation
14
First frame
20
First frame splitter support
22
Input shaft
23a
Input gear
23b
Right split shaft
24a
First right split gear
24b
Second right split gear
24c
Left split shaft
25a
First left split gear
25b
Second left split gear
25c
Right transfer support
26
Right transfer shaft
27a
First right transfer gear
27b
Second right transfer gear
27c
Left transfer support
28
Left transfer shaft
29a
First left transfer gear
29b
Second left transfer gear
29c
Center frame
30
Right center shaft
31a
First right miter gear
31b
Second right miter gear
31c
Right planetary gear head
32
Right spur gear
33
Left center shaft
35a
First left miter gear
35b
Second left miter gear
35c
Left planetary gear head
36
Left spur gear
37
Center frame journal
38
Top center shaft
41a
First top miter gear
41b
Second top miter gear
41c
Top planetary gear head
42
Top spur gear
43
Bottom center shaft
45a
First bottom miter gear
45b
Second bottom miter gear
45c
Bottom planetary gear head
46
Bottom spur gear
47
First compensation shaft support
52
First compensation shaft
53a
First compensation gear
53b
Second compensation shaft support
54
Second compensation shaft
55a
Second compensation gear
55b
Second frame
60
Second frame splitter support
62
Output shaft
63a
Output gear
63b
Top split shaft
64a
First top split gear
64b
Second top split gear
64c
Bottom split shaft
65a
First bottom split gear
65b
Second bottom split gear
65c
Top transfer support
66
Top transfer shaft
67a
First top transfer gear
67b
Second top transfer gear
67c
Bottom transfer support
68
Bottom transfer shaft
69a
First bottom transfer gear
69b
Second bottom transfer gear
69c
Planetary gear head
70
Input shaft
71
Sun gear
72
Planet carrier
73
Planet gear
74
Annulus
75
Annulus recess
76
DETAILED DESCRIPTION
Before the various embodiments of the present invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “front”, “back”, “up”, “down”, “top”, “bottom”, and the like) are only used to simplify description of the present invention, and do not alone indicate or imply that the device or element referred to must have a particular orientation. In addition, terms such as “first”, “second”, and “third” are used herein and in the appended claims for purposes of description and are not intended to indicate or imply relative importance or significance.
General Description of the Components
A description of the several components required for one embodiment of the epicyclic joint follows. A more detailed description of the operation and relation of the several elements are disclosed in the figures and the remainder of the specification.
It is contemplated that one type of epicyclic gearing system that may be used with the epicyclic joint 10 is a planetary gearing system. Planetary gearing systems typically include one sun gear and a plurality of planet gears. Such gearing systems are well known to those skilled in the art and therefore will not be described in further detail herein for purposes of clarity. U.S. Pat. Nos. 4,644,822, 4,618,022, and 4,727,954, all of which are incorporated by reference herein in their entireties, disclose common uses of planetary gear sets. Another type of epicyclic gearing system that may be used with the epicyclic joint 10 is a common differential with beveled gears. U.S. Pat. Nos. 2,608,261 and 3,400,610, both of which are incorporated by reference herein in their entireties, disclose apparatuses using differentials with beveled gears. Accordingly, the scope of the epicyclic joint 10 is not limited by the type of epicyclic gearing and/or gear sets used, and any such gearing and/or gear sets known to those skilled in the art may be used without departing from the spirit and scope of the epicyclic joint 10 as disclosed herein.
Operation of the Exemplary Embodiment
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIGS. 1-5 provide perspective views of one embodiment of the epicyclic joint 10 . In the embodiment of the epicyclic joint 10 shown in FIGS. 1-5 , the epicyclic joint 10 operates to allow a rotational energy input from the input shaft 23 a to be rotated about a first axis of rotation 12 and a second axis of rotation 14 to an output shaft 63 a . However, the epicyclic joint 10 may be configured for a single axis of rotation or for more than two axes of rotation within the spirit and scope of the epicyclic joint 10 as disclosed and claimed herein.
The embodiment of the epicyclic joint 10 pictured herein is comprised of three main portions: (1) a first frame 20 and the elements associated therewith (generally horizontally oriented in FIGS. 1-5 ); (2) a central frame 30 and the elements associated therewith; and, (3) a second frame 60 and the elements associated therewith (generally vertically oriented in FIGS. 1-5 ). The first frame 20 is pivotally mounted to the central frame 30 about the first axis of rotation 12 , and the second frame 60 is pivotally mounted to the central frame 30 about the second axis of rotation 14 . The first axis of rotation 12 and the second axis of rotation 14 are perpendicular to one another in the embodiment of the epicyclic joint 10 pictured herein, although other it may be configured for other orientations without departing from the spirit and scope of the epicyclic joint 10 as disclosed and claimed herein. In an embodiment not pictured herein, the epicyclic joint 10 includes only one axis of rotation, and in another embodiment not pictured herein, the epicyclic joint 10 includes more than two axes of rotation.
The first frame 20 in the embodiment shown is generally U-shaped, and includes a first frame splitter support 22 , which in the embodiment pictured herein is comprised of U-shaped member wherein each surface is perpendicular to the adjacent surface. Right and left transfer supports 26 , 28 , respectively, may be mounted to each side of the first frame 20 . These various elements of the first frame 20 may be separately formed and then joined together, or they may be integrally formed as one continuous structure. Furthermore, the orientations and/or configurations of the various elements of the first frame 20 may be different in other embodiments not pictured herein. The material used to construct the main frame 20 and/or the various components thereof may be any material known to those skilled in the art and suitable for the particular application. Such materials may include metals, alloys, synthetic materials such as polymers, wood, combinations thereof, or any other material known to those skilled in the art.
As indicated, the first frame 20 may be generally U-shaped, with the first frame splitter support 22 and right and left transfer supports 26 , 28 formed as protrusions thereon. An input shaft 23 a is rotatably mounted to the first frame 20 , as shown in FIG. 1 . Affixed to and rotatable with one end of the input shaft 23 a is an input gear 23 b , which is formed as a miter gear in the embodiment pictured herein. As rotational force is applied to the input shaft 23 a , that force is directly communicated to the input gear 23 b . A miter gear is one type of rotational translator that may be used with the epicyclic joint 10 .
Intermeshed with the input gear 23 b are a first right split gear 24 b and a first left split gear 25 b The first right and left split gears 24 b , 25 b rotate about an axes that is perpendicular to that of the input gear 23 b . Accordingly, it will be obvious to those skilled in the art that as the input gear 23 b rotates, it causes the right and left first split gears 24 b , 25 b to rotate in opposite directions. The first right split gear 24 b is affixed to and rotatable with a right split shaft 24 a , which may be pivotally mounted to said first frame splitter support 22 in the embodiment pictured herein. The first left split gear 25 b is affixed to and rotatable with a left split shaft 25 a , which also may be pivotally mounted to said first frame splitter support 22 in the embodiment pictured herein. Also affixed to the right split shaft 24 a and rotatable therewith is a second right split gear 24 c , and a second left split gear 25 c is affixed to and rotatable with the left split shaft 25 a . Accordingly, the right split shaft 24 a and associated components and left split shaft 25 a and associated components are one type of symmetrical splitter that may be used with the epicyclic joint 10 to divide the rotational energy of the input shaft 22 and translate that energy by ninety degrees. The first and second right split gears 24 b , 24 c , first and second left split gears 25 b , 25 c are one type of rotational energy dividing member, but other structures and/or methods known to those skilled in the art may be used to divide the rotational energy of the input shaft 22 as described in detail below.
A right transfer support 26 may be affixed to the first frame 20 , and a complimentary left transfer support 28 may also be affixed to the first frame 20 . A right transfer shaft 27 a may be pivotally mounted to the right transfer support 26 and a left transfer shaft 29 a may be pivotally mounted to the left transfer support 28 , as in the embodiment pictured in FIGS. 1-5 . A first right transfer gear 27 b may be mounted to and rotatable with one end of the right transfer shaft 27 a so that the first right transfer gear 27 b intermeshes with the second right split gear 24 b . A first left transfer gear 29 b may be mounted to and rotatable with one end of the left transfer shaft 29 a so that the first left transfer gear 29 b intermeshed with the second left split gear 25 b . Accordingly, the right transfer shaft 27 a together with the first and second right transfer gears 27 b , 27 c comprise one type of transfer member, as do the left transfer shaft 29 a together with the first and second right transfer gears 29 b , 29 c.
A center frame 30 may be positioned adjacent the first frame 20 on the end thereof that is opposite the input shaft 23 a . One embodiment of the center frame 30 is shown in detail in FIGS. 6A and 6B , in which embodiment the center frame 30 is generally square in shape. As with the first frame 20 , the components of the center frame 30 may be separately formed and then joined together, or they may be integrally formed as one continuous structure. The material used to construct the center frame 30 and/or the various components thereof may be any material known to those skilled in the art and suitable for the particular application. Such materials may include metals, alloys, synthetic materials such as polymers, wood, combinations thereof, or any other material known to those skilled in the art.
In the embodiment pictured herein, the first frame 20 is engaged with the center frame 30 via the cooperation of the right center shaft 31 a , left center shaft 35 a , right planetary gearhead 32 , and left planetary gearhead 36 . The right center shaft 31 a may be pivotally supported by the first frame 20 , and a first right miter gear 31 b may be affixed to and rotatable with the right center shaft 31 a . The left center shaft 35 a may be pivotally supported by the first frame 20 , and a first left miter gear 35 b may be affixed to and rotatable with the left center shaft 35 a.
A right planetary gearhead 32 may be positioned adjacent the first right miter gear 31 b . One type of planetary gearhead 70 that may be used with the epicyclic joint as disclosed herein is shown in FIGS. 7A and 7B . The planetary gearhead 70 shown in FIGS. 7A and 7B includes a sun gear 72 that may be affixed to and rotatable with the input shaft 71 (e.g., the right center shaft 31 a in an embodiment of the right planetary gearhead 32 ). In a typically planetary gearhead 70 , a plurality of planet gears 74 (three in the embodiment shown in FIGS. 7A and 7B , but which may be greater or fewer in other embodiments not pictured herein) are pivotally mounted to a planet carrier 73 , and the planet gears 74 are intermeshed with the sun gear 72 . An annulus 75 may be placed around the planet carrier 73 such that the annulus also is intermeshed with the planet gears 74 . The exterior surface of the annulus 75 includes an annulus recess 76 , which may be fashioned to pivotally engage a center frame journal 38 . In the embodiment of the planetary gearhead 70 shown in FIGS. 7A and 7B , the size and configuration of the sun gear 72 , planet gears 74 , and annulus 75 result in a three-to-one reduction in the rotational speed of the planet carrier 73 with respect to the sun gear 72 (and input shaft 71 , accordingly). However, because the embodiment of the epicyclic joint 10 shown herein transfers rotational energy from an input shaft 71 to a planet carrier 73 , and then from another planet carrier 73 back to an input shaft 71 (via the interaction of the second right miter gear 31 c , second left miter gear 35 c , second top miter gear 41 c , and second bottom miter gear 45 c ), the rotational speed of the output shaft 63 a on the second frame 60 is equal to that of the input shaft 23 a on the first frame 20 . This ratio may be different in other embodiments of the epicyclic joint 10 , and is therefore in no way limiting.
In the embodiment of the epicyclic joint 10 pictured in FIGS. 1-5 , right planetary gearhead 32 is pivotally mounted to the center frame 30 about the center frame journal 38 formed in the right side of the center frame 30 . The sun gear 72 in the right planetary gearhead 32 may be affixed to and rotatable with the right center shaft 31 a . The planet carrier 73 in the right planetary gearhead 32 may be affixed to and rotatable with the second right miter gear 31 c . A right spur gear 33 may be affixed to and rotatable with the annulus 75 of the right planetary gearhead 32 .
A first compensation shaft support 52 may be affixed to the center frame 30 . A first compensation shaft 53 a may be pivotally supported by the first compensation shaft support 52 . In the embodiment shown in FIGS. 1-5 , two first compensation gears 53 b are affixed to and rotatable with the first compensation shaft 53 a . One first compensation gear 53 b may be intermeshed with the right spur gear 33 and the other first compensation gear 53 b may be intermeshed with the left spur gear 37 , which is explained in detail below. The first compensation shaft support 52 may be affixed elsewhere on the epicyclic joint 10 in other embodiments thereof not pictured herein. The first compensation shaft support 52 may have any convenient orientation or configuration as long as it does not interfere with the other components of the epicyclic joint 10 and allows the appropriate components to engage one another
In a manner analogous to the right planetary gearhead 32 , a left planetary gearhead 36 may be positioned adjacent the first left miter gear 35 b . The left planetary gearhead 36 may be pivotally mounted to the center frame 30 about the center frame journal 38 formed in the right side of the center frame 30 . The sun gear 72 in the right planetary gearhead 36 may be affixed to and rotatable with the left center shaft 35 a . The planet carrier 73 in the left planetary gearhead 36 may be affixed to and rotatable with the second left miter gear 35 c . A left spur gear 37 may be affixed to and rotatable with the annulus 75 of the left planetary gearhead 36 .
Because the planet carrier 73 in the right planetary gearhead 32 rotates in the opposite direction of the planet carrier 73 in the left planetary gearhead 36 , the first compensation shaft 53 a and first compensation gears 53 b bind the right and left planetary gearheads 32 , 36 together. As is apparent from the description and various figures included herein, the right center shaft 31 a , right planetary gearhead 32 , left center shaft 35 a , and left planetary gearhead 36 cooperate to engage the first frame 20 with the center frame 30 about a first axis of rotation 12 . The first frame 20 is allowed to rotate with respect to the center frame 30 about the first axis of rotation 12 through the cooperation of the right and left planetary gearheads 32 , 36 with the first compensation shaft 53 a and first compensation gears 53 b.
More specifically, because the right spur gear 33 (which is affixed to and rotatable with the annulus 75 of the right planetary gearhead 32 ) may rotate independently from the second right miter gear 31 c (which is affixed to and rotatable with the planet carrier 73 of the right planetary gearhead 32 ), and because the left spur gear 37 (which is affixed to and rotatable with the annulus 75 of the left planetary gearhead 36 ) may rotate independently from the second left miter gear 35 c (which is affixed to and rotatable with the planet carrier 73 of the left planetary gearhead 36 ), both by virtue of the epicyclic qualities of the planetary gearhead 70 , the first frame 20 may pivot with respect to the center frame 30 about the first axis of rotation 12 (which also causes the annuluses 75 of the right and left planetary gearheads 32 , 36 to rotate about their respective center frame journals 38 ) without lashing of any of the gears in the epicyclic joint 10 . During rotation of the first frame 20 with respect to the center frame 30 , the first compensation shaft 53 a does not rotate, but instead requires that the right and left spur gears 33 , 37 rotate in the same direction by the same magnitude, even though the second right miter gear 31 c and second left miter gear 35 c are counter rotating. Accordingly, a stationary gear may be positioned to intermesh with either the right or left spur gear 33 , 37 to achieve the same functionality as that of the epicyclic joint 10 pictured herein.
In an embodiment not pictured herein, a single output gear (not shown) is pivotally supported by the center frame 30 and arranged to intermesh with both the second right and left miter gears 31 c , 35 c . The single output gear may be affixed and rotatable with an output shaft (not shown), such that the arrangement creates a single-axis epicyclic joint 10 . In light of the present disclosure it will become apparent to those skilled in the art that in an embodiment not pictured herein, the right spur gear 33 may be affixed to and rotatable with the planet carrier 73 of the right planetary gearhead 32 , and the second right miter gear 31 c may be affixed to and rotatable with the annulus 75 of the right planetary gearhead 32 with an analogous configuration for the elements on the left side of the epicyclic joint 10 to yield a similarly functional first axis of rotation 12 . Furthermore, it will also become apparent to those skilled in the art in light of the present disclosure that the right and left planetary gearheads 32 , 36 and first compensation shaft and gears 53 a , 53 b may be positioned adjacent the first frame splitter support 22 if spur transfer gears (not shown) are employed in lieu of the right and left transfer shafts and gears 27 a , 29 a , and 27 b , 27 c , 29 b , 29 c , respectively.
As is apparent from the detailed description and several figures included herein, the various elements of the first frame 20 may cooperate to divide a single rotational input into two counter-rotating rotational energy sources with axes of rotation perpendicular to that of the rotational input. Each counter-rotating rotational energy source may then be transferred to an epicyclic gearhead (which is shown as a planetary gearhead 70 in the embodiment pictured herein) and eventually combined to produce an output rotational energy source with an axis of rotation parallel to that of the rotational input.
To yield a second axis of rotation 14 as in the embodiment of the epicyclic joint 10 shown herein, a top and bottom planetary gearhead 42 , 46 may be pivotally mounted to the center frame 30 about respective center frame journals 38 . The top and bottom portions of the center frame 30 and second frame 60 are analogous to the right and left portions of the center frame 30 and first frame 20 , respectively. The top and bottom portions of the center frame 30 and second frame 60 are mirror images of the right and left portions of the center frame 30 and first frame 20 rotated along a horizontal axis by negative ninety degrees. Accordingly, the second top miter gear 41 c may be affixed to the planet carrier 73 of the top planetary gearhead 42 and the top spur gear 43 may be affixed to the annulus 75 of the top planetary gearhead 42 . The second bottom miter gear 45 c may be affixed to the planet carrier 73 of the bottom planetary gearhead 46 and the bottom spur gear 47 may be affixed to the annulus 75 of the bottom planetary gearhead 46 . The second top and bottom miter gears 41 c , 45 c may be intermeshed with both the second right miter gear 31 c and second left miter gear 35 c , such that the counter-rotating second right and left miter gears 31 c , 35 c cause the second top and bottom miter gears 41 c , 45 c to counter rotate. Accordingly, the configuration of the second right and left miter gears 31 c , 35 c and second top and bottom miter gears 41 c , 45 c translate the axis of rotation of the rotational energy by negative ninety degrees (i.e., from horizontal to vertical as shown in the orientation pictured in FIG. 5A ).
The rotation of the second top and bottom miter gears 41 c , 45 c causes the rotation of planet carriers 73 in the top and bottom planetary gearheads 42 , 46 , respectively. A second compensation shaft support 54 may be affixed to the center frame 30 to pivotally support a second compensation shaft 55 a , which second compensation shaft may have two second compensation gears affixed thereto and rotatable therewith. The second compensation shaft support 54 may be affixed elsewhere on the epicyclic joint 10 in other embodiments thereof not pictured herein. The second compensation shaft support 54 may have any convenient orientation or configuration as long as it does not interfere with the other components of the epicyclic joint 10 and allows the appropriate components to engage one another
The second compensation gears 55 b may be intermeshed with the top and bottom spur gears 43 , 47 , respectively. Because the top and bottom spur gears 43 , 47 may be affixed to and rotatable with the annuluses 75 of the top and bottom planetary gearheads 42 , 46 , respectively, the configuration of the second compensation shaft and gears 55 a , 55 b require that the rotation of the planet carrier 73 results in rotation of the sun gear 72 and top and bottom center shafts 41 a , 45 a . In a manner completely analogous to that explained in detail above for the first frame 20 and center frame 30 , the top center shaft 41 a (which may be pivotally supported by the second frame 60 ), top planetary gearhead 42 , bottom center shaft 45 a (which may be pivotally supported by the second frame 60 ), and bottom planetary gearhead 46 cooperate to engage the second frame 60 with the center frame 30 about a second axis of rotation 14 , which in the embodiment of the epicyclic joint 10 shown herein is perpendicular to the first axis of rotation 12 . The second frame 60 is allowed to rotate with respect to the center frame 30 about the second axis of rotation 14 through the cooperation of the top and bottom planetary gearheads 42 , 46 with the second compensation shaft 55 a and second compensation gears 55 b.
The first top miter gear 41 b , which may be affixed to and rotatable with the top center shaft 41 a (i.e., input shaft 71 ) and sun gear 72 in the top planetary gearhead 42 , may be intermeshed with the second top transfer gear 67 c . The first bottom miter gear 45 b , which may be affixed to and rotatable with the bottom center shaft 45 a (i.e., input shaft 71 ) and sun gear 72 in the bottom planetary gearhead 46 , may be intermeshed with a second bottom transfer gear 69 c . This engagement translates the rotational energy with axes of rotation in two primarily vertical directions (in the orientation shown in FIG. 1 ) to rotational energy with axes of rotation in two primarily horizontal directions (in the orientation shown in FIG. 1 ).
In a manner analogous to that of the first frame 20 , the second top and bottom transfer gears 67 c , 69 c , may be affixed to and rotatable with top and bottom transfer shafts 67 a , 69 a , respectively, and first top and bottom transfer gears 67 b , 69 b , may also be affixed to and rotatable with the top and bottom transfer shafts 67 a , 69 a , respectively. As in a manner similar to that described above for the first frame 20 , the top transfer shaft 67 a is pivotally supported by the top transfer support 66 , and the bottom transfer shaft 69 a is pivotally supported by the bottom transfer support 68 . Furthermore, the first top and bottom transfer gears 67 b , 69 b may be intermeshed with a second top and bottom split gear 64 c , 65 c respectively. As is readily apparent from FIG. 1 , this engagement translates the rotational energy with axes or rotation in two primarily horizontal directions (in the orientation shown in FIG. 1 ) to rotational energy with axes of rotation in two primarily vertical directions (in the orientation shown in FIG. 1 ).
The second top and bottom split gears 64 c , 65 c may be affixed to and rotatable with top and bottom split shafts 64 a , 65 a , respectively. In the embodiment pictured herein, the top and bottom split shafts 64 a , 65 a are each pivotally supported by the second frame 60 adjacent the second frame splitter support 62 , all of which is completely analogous to the first frame 20 . First top and bottom split gears 64 b , 65 b may be affixed to and rotatable with the top and bottom split shafts 64 a , 65 a , respectively. The first top and bottom split gears 64 b , 65 b , in turn, may be intermeshed with an output gear 63 b , which in the embodiment pictured herein combines two rotational energy sources into one single source transferred to the output shaft 63 a , to which the output gear 63 b may be affixed and with which the output gear 63 b may be rotatable. The first and second top split gears 64 b , 64 c , first and second left split gears 65 b , 65 c are one type of rotational energy combing member, but other structures and/or methods known to those skilled in the art may be used to divide the rotational energy of the output shaft 62 .
As with the first frame 20 and center frame 30 , the components of the second frame 60 may be separately formed and then joined together, or they may be integrally formed as one continuous structure. The material used to construct the second frame 60 and/or the various components thereof may be any material known to those skilled in the art and suitable for the particular application. Such materials may include metals, alloys, synthetic materials such as polymers, wood, combinations thereof, or any other material known to those skilled in the art.
In the embodiment of the epicyclic joint 10 pictured herein, the center frame 30 in combination with the second right, left, top, and bottom miter gears 31 c , 35 c , 41 c , 45 c , respectively serves as a type of translator. That is, the various elements associated with these components of the center frame 30 function to translate the axis of rotation for rotational energy into a different orientation, which in the embodiment pictured herein is from an axis that is generally horizontal to one that is generally vertical.
The epicyclic joint 10 is not limited by the number of planet gears 74 used for any of the planetary gear sets. Accordingly, any type of planetary gear set may be used with the epicyclic joint 10 without departing from the spirit and scope of the present invention. Furthermore, as previously mentioned, in light of the preceding disclosure, it will be apparent to those skilled in the art that a differential gear set may be used with the epicyclic joint 10 in place of a planetary gear set. Therefore, the specific type of epicyclic gear set used with the epicyclic joint 10 in no way limits the scope of the epicyclic joint 10 , and any type of epicyclic gear set known to those skilled in the art may be used with epicyclic joint 10 without departing from the spirit and scope thereof.
In other embodiments of the epicyclic joint 10 not pictured herein, other structures and/or methods other than the right transfer shaft 27 a and associated right transfer gears 27 b , 27 c , left transfer shaft 29 a and associated left transfer gears 29 b , 29 , top transfer shaft 67 a and associated top transfer gears 67 b , 67 c , and bottom transfer shaft 69 a and associated bottom transfer gears 69 b , 69 c may be used to transport the rotational energy from a rotating member positioned on the first frame 20 to the center frame 30 and/or from the center frame 30 to the second frame 60 . For example, large spur gears (not shown) may be used, as may chains with sprockets, or any other structure and/or method known to those skilled in the art.
In light of the present disclosure, it will be obvious to those skilled in the art that the symmetry associated with the embodiment of the epicyclic joint 10 shown in the various figures herein possesses certain inherent advantages. The input rotational energy is symmetrically divided about the first frame 20 , which rotational energy is then symmetrically translated by ninety degrees about the center frame 30 , which rotational energy is then transmitted along the second frame 60 before being combined into one rotational energy output at the output shaft 63 a.
Other embodiments of the epicyclic joint 10 may not require the level of symmetry contained in the embodiment pictured herein. In fact, in other applications it is contemplated that non-symmetrical configurations may be advantageous. For example, in another embodiment of the epicyclic joint not pictured herein, the rotational energy is not symmetrically divided about the first frame 20 and/or not symmetrically translated about the center frame 30 . Furthermore, the rotational energy may be transferred along the second frame 60 and combined adjacent thereto in a non-symmetrical fashion. Such non-symmetrical embodiments of the epicyclic joint 10 may employ torque vectoring apparatuses, such as that disclosed in U.S. Pat. No. 7,491,147, which is incorporated herein in its entirety.
As will be obvious to those skilled in the art in light of the present disclosure and accompanying drawings, the length of the first frame 20 with respect to the size of the center frame 30 and second frame 60 is an important factor in determining how far the first frame may rotate with respect to the center frame 30 about the first axis of rotation 12 . For example, if the first frame 20 is sufficiently lengthened with respect to the second frame 60 , but the center frame 30 remains in proportion to the second frame 60 as shown in the various figures contained herein, the epicyclic joint 10 may be configured to allow the first frame 20 to rotate three hundred and sixty degrees with respect to the center frame 30 about the first axis of rotation 12 . In a similar manner, the epicyclic joint 10 may be configured to allow the second frame 60 to rotate three hundred and sixty degrees with respect to the center frame 30 about the second axis of rotation 14 . Accordingly, the degree of freedom of motion for either the first frame 20 or second frame 60 with respect to one another or the center frame 30 in no way limits the scope of the epicyclic joint 10 as disclosed and claimed herein.
It will be apparent to those skilled in the art in light of the present disclosure that the epicyclic joint 10 may be configured with more than two axes of rotation. In such an embodiment, another frame similar to the center frame 30 would be positioned adjacent the second frame 60 for engagement therewith. The output shaft 63 a could be affixed to and rotatable with a miter gear (not shown), the cooperated with two other miter gears (not shown) to divide the rotational energy of the output shaft 63 a into corresponding phases. The orientation of various axes of rotation of such an epicyclic joint 10 may be configured differently depending on the specific application, as may the maximum angle or rotation of any component about such an axis. The fact that the first and second axes of rotation 12 , 14 are perpendicular to one another and that both are perpendicular to the longitudinal axis of the input shaft 23 a in the embodiment pictured herein is in no way limiting. Accordingly, the epicyclic joint 10 may be used with any number of rotational axes in any number of orientations within the spirit and scope of the epicyclic joint 10 as disclosed and claimed herein.
The various advantages of the epicyclic joint 10 as disclosed and described herein will be apparent to those skilled in the art in light of the present disclosure. For example, one advantage the epicyclic joint 10 is increased range of motion about the first and second axes of rotation 12 , 14 . In the embodiment pictured herein, the range of motion for each axis of rotation 12 , 14 may greater than two hundred and seventy degrees. As explained above, in other embodiments not pictured herein the range of motion for one axis 12 , 14 may be as large as 360 degrees. Another advantage of the epicyclic joint 10 is the lack of rotating frame members. In the epicyclic joint 10 , the first frame 20 , central frame 30 , and second frame 60 do not rotate in a manner dependent on the rotational energy of any of the components thereof. Instead, the first, center, and second frames 20 , 30 , 60 rotate about either the first axis of rotation 12 and/or the second axis of rotation 14 so that the epicyclic joint 10 may be oriented in the most advantageous direction for the specific application. The compensators (first compensation shaft and gears 53 a , 53 b and second compensation shaft and gears 55 a , 55 b in the embodiment pictured herein) allow the epicyclic joint 10 to be configured in an infinite number of orientations without additional shock, vibrations, or other perturbations imparted to the other components of the epicyclic joint 10 as rotational energy is being transmitted through the epicyclic joint 10 .
The epicyclic joint 10 and various elements thereof may be constructed of any suitable material known to those skilled in the art. In the embodiment as pictured herein, it is contemplated that various frame elements, shaft elements, and gear elements will be constructed of metal, aluminum, metallic or aluminum alloys, polymers, or combinations thereof. However, other suitable materials may be used.
Other methods of using the epicyclic joint 10 will become apparent to those skilled in the art in light of the present disclosure. Accordingly, the methods and embodiments pictured and described herein are for exemplary purposes only, and are not intended to limit the scope of the epicyclic joint 10 in any way. The scope of the epicyclic joint 10 is not limited by the embodiments pictured and described herein, but is intended to apply to all similar apparatuses and methods for allowing a rotational energy to be transmitted about one or more axes or rotation, which one or more axes or rotation are distinct from the axis of rotation of the rotational energy source. Modifications and alterations from the described embodiments will occur to those skilled in the art without departure from the spirit and scope of the epicyclic joint 10 .
It is understood that the epicyclic joint 10 as disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the epicyclic joint 10 . The embodiments described herein explain the best modes known for practicing the epicyclic joint 10 and will enable others skilled in the art to utilize the same. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art. | The various embodiments disclosed and pictured herein are directed to an epicyclic joint with at least one axis of rotation. The epicyclic joint includes rotational members mounted to frame members in such a manner that rotational energy may be transposed along multiple axes of rotation without the need for the frame members to rotate. Epicyclic gear sets and compensation gears and shafts are employed to mitigate vibration, stress, and perturbation of the rotating members when the orientation of the epicyclic joint is varied along any of the axes of rotation. Planetary gear sets or differential gear sets may be used with the epicyclic joint, as may spur gears and miter gears. | 5 |
This application is a continuation of application Ser. No. 616,705, filed June 4, 1984, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sheet loading device for causing sheets (cut sheets or paper leaves) put out one after another from a sheet output apparatus such as a laser beam printer or a copying apparatus onto a sheet receiving member to be loaded in orderly, mutually superposed relationship without being deviated from one another.
2. Description of the Prior Art
An apparatus such as a laser beam printer which puts out a great quantity of sheets generally has at the sheet output portion thereof a sheet loading device (a stacker) provided with sheet aligning mechanism.
FIG. 1 of the accompanying drawings is a perspective view showing the essential portions of an example of such device. Reference numerals 1 and 1 designate a pair of sheet discharge rollers provided on the side of a sheet output apparatus such as a laser beam printer, not shown, and reference numeral 2 denotes an output sheet supporting bed as a sheet receiving member disposed in front of the pair of sheet discharge rollers. Sheets P are discharged one after another onto this supporting bed 2 and piled thereon. The supporting bed 2 is initially raised to a level slightly lower than the sheet output portion of the pair of sheet discharge rollers 1 and 1 by a vertically moving mechanism, not shown, and it is automatically lowered little by little as the piling of sheets progresses, and can support thereon a great quantity of sheets before it reaches its lowermost limit of downward movement.
The sheet aligning mechanism serves to bring the sheets discharged one after another onto the bed 2 into an orderly piled condition and comprises a pair of sheet guide bars 3 and 3 vertically disposed as discharged sheet front side positioning members on the front side of the sheet supporting bed 2, a pair of paddles 4 and 4 disposed between the pair of sheet guide bars 3 and 3, a sheet guide plate 5 vertically disposed as a discharged sheet left side positioning member on the left side of the sheet supporting bed 2 and parallel to the left side edge of the bed 2, and a putter 6 disposed on the right side of the sheet supporting bed 2. These members 3-6 are positioned and supported on an immovable member, not shown.
The sheet guide bars 3 and 3 and the sheet guide plate 5 are disposed in a relation in which a plane containing the sheet guide bars 3 and 3 and a plane containing the sheet guide surface of the sheet guide plate 5 intersect each other perpendicularly to each other.
Each of the paddles 4 comprises a rotary member 41 and a plurality of radially extending vane members 42 formed of a flexible material such as rubber sheet strips or the like and mounted around the rotary member 41, and may be rotatively driven in the direction of arrow by a motor 43 through a shaft 44, whereby the vane members 42 are rotated in friction contact with the upper surface of the piled sheets on the bed 2 in such a manner that they strike said upper surface, and thus, a gathering force toward the sheet guide bars 3 and 3 acts on the uppermost one of the piled sheets on the bed 2.
The putter 6 swings to right and left about a vertical shaft 62 with the intermittent supply of power to an electromagnetic solenoid-plunger 61 and strikes the right side edge of the piled sheets P on the bed 2, whereby a gathering force toward the sheet guide plate 5 acts on the piled sheets P on the bed 2.
Thus, the sheets P discharged one after another onto the bed 2 are positively gathered toward the sheet guide bars 3 and 3 which are the sheet front side positioning members by the paddles 4 and 4 and the front side of the sheets strikes against the sheet guide bars 3 and 3 and the sheets become positioned thereby. Also, the sheets are positively gathered toward the sheet guide plate 5 which is the sheet left side positioning member by the putter 6 and the left side of the sheets strikes against the surface of the sheet guide plate 5 and the sheets become positioned thereby. Thus, the individual discharged sheets P are piled on the bed 2 in orderly, mutually superposed relationship with the sheet guide bars 3, 3 and the sheet guide plate 5 as the sheet front side and left side positioning members.
Now, to enable the above-described sheet loading device to be used correspondingly with various sheet sizes, the sheet guide plate 5 which is the sheet left side positioning member may be fixed, but the sheet guide bars 3, 3 which are the sheet front side positioning members, the paddles 4, 4 and the putter 6 must be designed to be movable and adjustable in position. However, the entire device becomes complicated and its operability is poor when the members 3, 3, 4, 4 and 6 are designed to be movable in two different directions and adjustable in selected positions.
Also, the loading device of this type has heretofore been constructed as follows:
(1) The output sheets are loaded onto the pallet;
(2) The pallet is vertically movable by a lift device to keep the supporting surface constant;
(3) When a predetermined quantity of sheets has been loaded, the lift device is lowered to its lowermost limit;
(4) That condition is a condition in which the sheets and the pallet have become contained in the container; and
(5) The container is installed on a bed which can be drawn out, and the bed may be drawn out and the container with the sheets and the pallet contained therein may be removed and carried.
Such construction has led to the undesirable possibility that during sheet loading operation, the bed may be drawn out by mistake and the sheets become jammed. Also, the container must be set on the bed while containing the pallet therein, but when the operator forgets to place the pallet into the container, the sheets may again become jammed and this has sometimes led to the undesirable possibility of damaging the device.
SUMMARY OF THE INVENTION
It is an object of the present invention to enable discharged sheets to be reliably and properly aligned in a sheet loading device provided with a sheet receiving member for supporting thereon the discharged sheets in mutually superposed relationship.
It is a further object of the present invention to provide a sheet loading device in which the position of a sheet aligning mechanism relative to the sheet receiving member may be changed corresponding to the size of the sheets to enable the sheet loading device to be used correspondingly to various sheet sizes and which is simple in construction and excellent in operability.
It is still a further object of the present invention to prevent the jamming by malfunctioning or the damaging of the device which has been a problem peculiar to the prior art.
The present invention is characterized in that a sheet positioning member constituting the sheet aligning mechanism and means for frictionally contacting the upper surface of the sheets piled on the sheet receiving member and gathering the sheets toward the sheet positioning member are mounted and supported on a member which is free to reciprocally move and position and the support member is moved in accordance with the size of the sheets put out onto the sheet receiving member to position the sheet aligning mechanism mounted and supported on said member at a position corresponding to and matching the size of the sheet.
According to this feature of the present invention, positional adjustment of the sheet aligning mechanism corresponding to various sheet sizes may be effected in one direction X-X' and therefore, the construction of the mechanism becomes simple and the device is excellent in operability and practical and thus effectively can achieve its intended purposes.
Also, the present invention is characterized in that in a sheet loading device for loading discharged sheets in mutually superposed relationship, a locking mechanism is provided on a bed which can be drawn out and the bed is pushed in only when the container and the pallet have been set in predetermined states and during sheet loading operation, the bed cannot be drawn out.
According to this feature of the present invention, when the container and the pallet are to be set on the bed, every malfunctioning can be prevented and also, the malfunctioning of drawing out the bed during loading can be prevented and thus, the jamming of sheets or the damaging of the device which is attributable to such malfunctioning can be prevented. Accordingly, further, the container and the pallet are always in proper positions and therefore, the intended purpose of properly aligning the sheets can also be achieved.
The invention will become more fully apparent from the following detailed description thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the essential portions of the device according to the prior art.
FIG. 2 is a partly cut-away perspective view of an embodiment of the device of the present invention.
FIG. 3 is a perspective view for illustrating the operation of the pallet of FIG. 2.
FIG. 4 is a perspective view showing a condition in which a bed has been drawn out.
FIG. 5 is a perspective view showing the bed.
FIG. 6 is a perspective view showing a container.
FIG. 7 is a cross-sectional view showing a projection of the container.
FIG. 8 is a perspective view showing a pallet.
FIG. 9 is a side cross-sectional view the details of a locking mechanism.
FIG. 10 is a side cross-sectional view of the locking mechanism when the container is not set.
FIG. 11 is a side cross-sectional view of the locking mechanism when the container is invertedly set.
FIG. 12 is a side cross-sectional view of the looking mechanism when the pallet is not set.
FIG. 13 is a side cross-sectional view of the locking mechanism when the pallet is reversely set.
FIG. 14 is a side cross-sectional view of the locking mechanism when the bed is pushed in.
FIG. 15 is a side cross-sectional view of the locking mechanism when the pallet is elevated.
FIG. 16 is a side cross-sectional view showing another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 shows an embodiment of the present invention. In FIG. 2, reference numeral 110 designates a supporting bed which can be moved in and out axially of a pair of sheet discharge rollers 1 and 1 by slide rails 111 and 111. Denoted by 152 is a container positioned and supported on the bed 110. The placement of the container 152 onto the bed 110 may be accomplished by drawing out the bed 110 toward this side, and then sufficiently pushing back the bed 110 into the apparatus until it is stopped by a stopper member (not shown), whereupon the container 152 on the bed 110 is moved to the front of the pair of sheet discharge rollers 1 and 1 and is positioned thereat. Letter S designates a sensor adapted to be switched on by being pushed by the moved container 152 and detects that the container 152 is present in the device. Reference numeral 153 designates a movable pallet contained in the container 152. The pallet 153 is a member corresponding to the sheet supporting bed 2 shown in FIG. 1 and is vertically moved with its underside supported by a lift member 154 vertically moved by a vertically moving mechanism, not shown.
Reference numerals 115 and 115 denote a pair of horizontal, parallel rail members disposed above the container 152 in the device and above the pair of sheet discharge rollers 1 and 1 and extending in the forward and backward direction (X-X'), reference character 115a designates support members for supporting the opposite ends of each of the rail members, and reference numeral 116 denotes a sheet aligning mechanism mounting board mounted to and supported by the rail members through slide locks 117. Accordingly, the board 116 is slidable back and forth along the rail members 115 and 115. Reference numeral 118 designates a handle formed of a plate spring having its base secured to the board 116 to operate the board, and reference numeral 119 denotes a handle restraining comb-tooth plate formed with a plurality of recesses 119a in which the handle 118 may fit. The handle 118 formed of a plate spring may be disengaged from a recess 119a of the comb-tooth plate 119 by being slightly upwardly flexed as indicated by dots-and-dash lines against the resiliency thereof to thereby operate and move the board 116, and the handle 118 may be again engaged with a recess 119a at the required position to thereby position the board 116.
Reference numerals 120, 120, 121 and 122 designate sheet front side positioning members, a paddle and a sheet left side positioning member, respectively, as the components of the sheet aligning mechanism. These members correspond to the members 3, 3, 4, 4 and 5 in the device of FIG. 1, and are mounted and supported in predetermined positional relations to the underside of the board 116 as by screws.
The paddle 121, unlike the paddle shown in FIG. 1, has its axis of rotation disposed in the corner at which a plane containing the sheet front side positioning members 120 and 120 intersects a plane containing the surface of the sheet left side positioning member 122 obliquely with respect to the plane containing the sheet front side positioning members 120 and 120. By so disposing the paddle, a sheet discharged toward the pallet 153 which is the sheet supporting bed is subjected to a gathering force in an oblique direction Z toward the corner at which the plane containing the sheet front side positioning members 120 and 120 intersects the plane containing the surface of the sheet left side positioning member 122, by the paddle 121, and by the component of the gathering force in the oblique direction Z which is toward the members 120 and 120 and the component of said gathering force which is toward the member 122, the front side and left side of the sheet finally bear against the members 120, 120 and the member 122 and thus, the sheet is positioned. Accordingly, even if the putter 6 as shown in the apparatus of FIG. 1 is not disposed, there can be obtained a sheet aligning action similar to that of the FIG. 1 apparatus.
Thus, correspondingly to the size of the sheet P put out from the sheet output apparatus, the board 116 is moved along the rail members 115 and 115 by the handle 118 in the forward direction X in which the spacing between the pair of sheet discharge rollers 1, 1 and the sheet front side positioning members 120, 120 widens or in the backward direction X' in which said spacing narrows, whereby the position of the board 116 is adjusted. By this operation of moving the board 116, the sheet aligning mechanism 120, 120, 121, 122 integrally mounted and supported on the board 116 is also moved in the forward and backward direction X-X' and can be positioned at a position corresponding to the required sheet size, and that position is fixed by fitting the handle 118 into one of the restraining recesses 119a.
When it is detected by a sheet-amount sensor, not shown, that the loading of sheets onto the pallet 153 and the sequential downward movement of the pallet 153 progress and the amount of sheets loaded on the pallet has reached the maximum capacity of the container, a warming of fully loaded container is output by the detection signal. Alternatively, the operation of the present machine is automatically H) interrupted. Then, the lifter 154 lowers to its home position which is the lower limit of downward movement and the weight of the pallet 153 and of the sheets supported thereon shifts from the lifter 154 toward the bottom plate of the container 152 and thus, the pallet 153 is disconnected from the lifter 154. Also, the supporting bed 110 is unlocked.
Thus, by sufficiently drawing out the supporting bed 110 toward this side of the stacker device by utilization of a handle 110a, the container in which a great quantity of sheets is supported and contained is drawn out, and then is removed from the bed 110 by utilization of a handle 152a and carried to a required working station.
Even when the quantity of sheets supported on the pallet 153 is not the maximum capacity thereof, if a pallet-lowering switch, not shown, is depressed, the lifter 154 will lower to its home position and it will become possible to remove the container 152.
In the device of the above-described embodiment, the movement standard lines of sheets of various sizes are the left side of the sheets, but in a case where the right side of the sheets is the movement standard line, a sheet right side positioning member may be disposed instead of the sheet left side positioning member 122 and the paddle 121 may be disposed so as to rotate in contact with the upper surface of the right corner of the front side of a sheet.
The movement of the board 116, namely, the sheet aligning mechanism 120, 120, 121, 122, in the forward and backward direction X-X' need not always be effected by manual operation using the handle 118, but design may also be made such that said movement is accomplished by the drive of a motor or that said movement and positioning of the board is automatically accomplished in accordance with the sheet size information from the sheet output apparatus.
The container 152 may be interchanged correspondingly to the sizes of output sheets. The sheet supporting device itself may also be of the type in which the sheet supporting bed is fixedly disposed.
FIG. 3 is a perspective view for explaining the upward and downward movements of the pallet 153 of FIG. 2.
The present device will be further described by reference to FIG. 3. The paddle 121 has its tip ends formed of an elastic material such as rubber and is rotated in the direction of arrow by the drive of a motor 146. This paddle 121 contacts the paper sheet P and draws the paper sheet P toward guides 120 and 122 by the friction force thereof with the paper sheet and aligns the paper sheet P. Also, the pallet 153 is of a U-shape having downwardly bent legs 153a and 153b and supports paper sheets P on the flat surface 153c thereof. Reference numeral 154 designates a lift device for keeping the level of the sheet supporting surface always constant. The lift device 154 is vertically movable along rails 160 (FIG. 4) by a motor (not shown).
FIG. 4 is a perspective view showing a condition in which the bed 110 has been drawn out from its predetermined loaded position by sliding the rails 111.
When the bed 110 is pushed in, it is positioned so that a fork 154a which is the fore end of the lift device 154 positioned at its lowermost limit enters the space 162 between the container 152 and the pallet 153 (between the bottom surface 152f of the container 152 and the flat surface 153c raised by the legs 153a and 153b). Reference numeral 163 designates a hole designed to be engaged by the tip end 164b of a detecting lever 164. Reference numeral 165 denotes a stopper designed to be engaged with the detecting lever 164 as will later be described in detail.
FIG. 5 is a perspective view showing a condition in which the container 152 and pallet 153 in FIG. 4 have been removed and also illustrating the bed 110.
In FIG. 5, apertures 131-143 are formed in the bed 110 and are used to install the container 152 at a predetermined location on the bed 110.
FIG. 6 is a perspective view showing the container 152.
Positioning projections 152a, 152b, 152c. 152d and 152e are provided on the bottom surface 152f of the container 152. The projections 152a 152d are provided at the corners of the bottom surface 152f and the projection 152e is provided near the projection 152c.
The shape of each projection is shown in FIG. 7. The projection 152a is illustrated as the representative in this Figure. An aperture 152al is formed at the center of the projection 152a. Likewise, apertures 152bl-152dl are formed centrally of the projections 152b-152d respectively. The projections 152a, 152b, 152c, 152d and 152e fit in the apertures 131, 136, 137, 138 and 139, respectively, formed in the bed 110, whereby the container 152 may be positioned on the bed 110. The apertures 132-135 and 140-143 of the bed 110 are formed as the apertures for a container corresponding to another paper size.
FIG. 8 is a perspective view showing the pallet 153.
This pallet 153 is provided with positioning projections 153d, 153e, 153f and 153g at the bottom of the inwardly bent portions 153al and 153bl of the legs 153a and 153b. The projections 153d-153g fit in the downwardly facing recesses a-e of the projections 152a, 152b, 152c and 152d provided on the bottom surface 152f of the container 152, whereby the pallet 153 is positioned relative to the container 152. Also, this pallet 153 is point-symmetrical and can be set on the container 152 by being rotated by 180°.
FIG. 9 is a side cross-sectional view showing the details of a locking mechanism.
A detecting lever 164 as detecting means is hook-shaped as shown. The rear end 164a of the detecting lever 164 is in light contact with the projection 153d fitting in the recess of the container 152 and positioning the pallet 153 at a predetermined position relative to the container 152. This detecting lever 164 is pivotally mounted on a shaft 166 fixed to the bed 110, and a force which tends to rotate the detecting lever 164 in the direction of arrow F by the weight of the lever 164 itself is acting on the detecting lever 164. The container 152 is positioned at a predetermined position relative to the bed 110 by the projection 152a thereof fitting in the aperture 131 of the bed 110.
Operation of the sheet loading device having the above-described construction will now be described.
Description will first be made by reference to FIG. 3.
First, for example, a start button (not shown) is depressed and the pallet 153 is moved up to a position A by the use of the lift device 154. Paper sheets P put out one after another are placed onto the upper surface of the pallet 153. At this time, the lift device 154 lowers (to a position B indicated in FIG. 3) so as to keep the position of the supporting surface constant by a well-known technique. When the pallet 153 lowers to a position C indicated in FIG. 3 and supports paper sheets P thereon, a full load detecting mechanism, not shown, operates to stop the inputting of paper sheets thereafter and lowers the lift device 154 to its lowermost position. Thus, the pallet 153 comes to a position D indicated in FIG. 3 and the contact between the lift device 154 and the pallet 153 is released. Therefore, in this state, the bed 110 can be drawn out from its predetermined loaded position without any hindrance and the container 152 can be removed and carried.
Description will now be made of a case where the empty container 152 is set on the bed 110.
When, as shown in FIG. 9, the container 152 having the supporting bed positioned at a predetermined position by the projections 153d-153g fitting H' in the recesses a-d of the container 152 is positioned at a predetermined position on the bed 110 by the projections 152a-152d thereof fitting in the apertures 131-134 of the bed 110, the projection 153d of the pallet 153 strikes the rear end 164a of the detecting lever 164 and the fore end 164b of the detecting lever 164 pivots counter-clockwise about the shaft 166 and comes out of contact with the stopper 165.
Accordingly, when the pallet and the container have been set normally, it becomes possible to push the bed 110 into its predetermined loaded position.
FIG. 10 shows a case where the container 152 is not set on the bed 110. In this case, the fore end 164b of the detecting lever 164 pivots clockwise due to its own weight and, when it is displaced to push the bed 110 into its loaded position, the fore end of the detecting lever comes to bear against the stopper 165 (this state is indicated by dot-and-dash line).
Accordingly, if the container 152 is not set, the bed 110 cannot be pushed in and thus, malfunctioning can be prevented.
FIG. 11 shows a case where the container 152 has been set on the bed 110 in the reverse direction. In this case, the projections 152a, 152b, 152c, 152d and 152e of the container 152 are asymmetrically arranged and therefore cannot fit in the apertures 131, 136, 137, 138 and 139 of the bed 110. That is, as shown, for example, the projection 152e strikes against the bed 110. Accordingly, the container 152 floats up from the bed 110 and the projection 153d cannot push the rear end 164a of the lever 164 and thus, the detecting lever 164 comes into contact with the stopper 165.
Accordingly, where the container 152 has been set in the reverse direction, the bed 110 cannot be pushed into its predetermined loaded position and malfunctioning can be prevented.
FIG. 12 shows a case where only the container 152 is set on the bed 110 and the pallet 153 is not set. The rear end 164a of the lever 164 is not pressed and likewise, the bed 110 cannot be pushed in and thus, malfunctioning can be prevented.
Further, FIG. 13 is a side cross-sectional view showing a case where the pallet 153 has been set invertedly. Again in this case, the rear end 164a of the lever 164 is not pressed and likewise, the bed 110 cannot be pushed in and thus, malfunctioning can be prevented.
FIG. 14 is a side cross-sectional view showing a case where the container 152 and the pallet 153 have been set normally on the bed 110 and the bed 110 has been pushed into its predetermined loaded H; position
The rear end 164a of the detecting lever 164 which has so far projected into the container 152 through the aperture 131 of the bed 110 and the aperture 152al of the projection 152a by its own weight is depressed by the projection 153d of the pallet 153, and the fore end 164b of the lever 164 pivots clockwise and comes into the aperture 163 of the rear side plate 170 of the body.
FIG. 15 is a side cross-sectional view showing a condition in which the pallet 153 has been elevated for the purpose of loading paper sheets thereonto.
Since the pallet 153 is elevated during paper sheet loading, the detecting leve r 164 pivots clockwise from its position shown in FIG. 14 by its own weight with the upward movement of the pallet 153 and the fore end 164b thereof comes into engagement with the aperture 163 of the rear side plate 170 of the body. Accordingly, the bed 110 cannot be drawn out during paper sheet loading and malfunctioning is prevented.
When the paper sheet loading is terminated and the pallet 153 lowers to its lowermost position, the state shown in FIG. 14 is restored and the bed 110 can be drawn out.
FIG. 16 is a side cross-sectional view of another embodiment showing a condition in which the bed 110 has been pushed in.
In the present embodiment, a photointerrupter 171 is attached to the rear side plate 170. When the container 152 and the pallet 153 are set in their regular state and the bed 110 is pushed into its predetermined loaded position, the detecting lever 164 interrupts the photointerrupter 171 and it is detected that the container and the pallet have been set normally. Thereafter, control is effected so that the lift device 154 moves up in response to the detection signal.
Accordingly, the set condition can be reliably detected. Also, when the lift device 154 is to be lowered after the paper sheet loading, control is effected so that the lift device 154 is stopped when the photointerrupter 170 detects the detecting lever 164 (the arrival of the detecting lever 164 at the solid-line position from the position indicated by dots-and-dash line is detected, thereby stopping the lift device).
In the present embodiment, as described above, the movement of the pallet 153 is directly detected and this leads to the possibility of accomplishing the most reliable detection.
The detecting means is not limited to the detecting lever shown in the embodiments, but may also be one constructed by utilization of a link mechanism, for example. The stopper member is neither limited to the stopper shown in the embodiments, but may be one which permits displacement of the bed when the detecting means detects that the container or the pallet has been mounted at a predetermined position, such as a member having a protrusion disengageably engaged with the recess of the detecting means. Further, the control means is not limited to the apertures shown in the embodiments, but may also be, for example, a member having a protrusion disengageably engaged with the recess of the detecting means. | This invention relates to a sheet loading device for causing sheets put out one after another from a sheet output apparatus such as a laser beam printer or a copying apparatus onto a sheet receiving member to be loaded in orderly, mutually superposed relationship without being deviated from one another. The sheet loading device is provided with a sheet receiving member for supporting thereon discharged sheets in mutually superposed relationship, a sheet loading positioning member, gathering device for frictionally contacting the upper surface of the sheets supported on the sheet receiving member and gathering the sheets in an oblique direction, and a support member free to move and position and supporting the gathering device and the positioning member, and is characterized in that the support member is moved in accordance with the size of the sheets put out onto the sheet receiving member to thereby position the gathering device and the positioning member mounted on the support member at positions corresponding to and matching the size of the sheets. The sheet loading device is also characterized in that during sheet loading operation, the sheet receiving member cannot be placed out of the device and the sheet receiving member cannot be inserted into the device unless it is properly prepared. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
Priority is claimed from UK Patent Application No. 0504061.3 filed Feb. 28 2005 under 35 USC 119, the disclosure of which is incorporated herein in its entirety by reference.
All references cited in the specification, and their references, are incorporated by reference herein in their entirety where appropriate for teachings of additional or alternative details, features and/or technical background.
US GOVERNMENT RIGHTS
Not applicable.
FIELD OF THE INVENTION
The present invention relates to a diversity transmitter, to a base station, a mobile radio communication device and a broadcast transmitter each comprising such a diversity transmitter; and to a method of transmitting data in an OFDM system.
BACKGROUND TO THE INVENTION
Orthogonal frequency division multiplexing (OFDM) based systems are the most promising candidates for 4th generation broadband mobile communication networks. Such systems deployed with multiple-input multiple-output (MIMO) techniques promise satisfaction of the ever growing demands of multi-media services and applications. OFDM has been successfully used in standards for digital audio broadcasting (DAB), terrestrial digital video broadcasting (DVB-T), and wireless local area networks (WLANs), for example. It reduces receiver complexity in the equalization and symbol decoding stages by transmitting each symbol over a single flat sub-channel. However, OFDM's inability to extract multipath diversity (inherently present in the broadband wireless channel) and to guarantee symbol detection, when channel nulls occur on parallel sub-channels, are two adverse effects associated with its simplicity.
Diversity techniques are proven to be very effective for combating time varying multipath fading in broadband wireless channel environments. In these techniques, some less attenuated replicas of the transmitted signal, either in the time, frequency or spatial domain, or a combination of all three, are provided to the receiver. These replicas minimize the degrading channel imperfections and enhance the system performance. Temporal diversity is widely achieved by using forward error correction (FEC) coding in combination with (random) time interleaving, whereas frequency diversity can be exploited by using non-linear equalizers or Rake receivers in a single carrier system or with a FEC in an OFDM based system. Spatial diversity in the form of spatially separated, cell sectoring, or polarized antennas have also been of major interest in the research community. All of the above mentioned diversity methods are severely dependent on channel scenarios, transmission data rate, Doppler spread and channel delay spread. Therefore, it is very difficult to realize all forms of diversity in one particular system; for example, in case of slow fading channels with large delay spreads, random time interleaving with FEC or channel coding becomes ineffective. Similarly, frequency interleaving becomes useless for channel environments showing a typical frequency-flat profile. In contrast, spatial diversity is the best approach towards mitigating the channel impairments and enhancing performance, as long as signals at the transmit and receive antenna elements are sufficiently de-correlated.
In connection with diversity transmitters, different concepts are being discussed for multi-carrier, in particular OFDM systems. OFDM is ideally suited for broadband frequency selective channels as it gives the opportunity to use the existing transmit diversity techniques (designed for flat fading channels) in such environments. The design and performance criteria for broadband MIMO OFDM systems promises an excellent diversity level, which is multiplicative of transmit and receive antennas, and the number of multipath components of the broadband channel (with an ideal assumption like equal power in all multipath components and fixed delay between them) [1]. However, the orthogonal space-time block code (STBC) processing scheme proposed in [2] and generalized in [3] failed to extract any or almost no multipath diversity in OFDM. Space-time trellis codes (STTC) of [4], promise diversity as well as coding gain but become unattractive due to their complexity in practical realizations. Other transmit diversity techniques like non-orthogonal block codes also faced the same dilemma of lack of frequency or multipath diversity. This gave a research challenge to design new set of codes for OFDM based systems that would extract at least some of the promised advantages of MIMO OFDM.
Nevertheless, some transmitter diversity schemes, in particular Delay Diversity (DD), when modified to be used in OFDM systems gives excellent simplicity and performance. This technique can be found in many forms, where it differs slightly in terms of its placement in the system. Cyclic Delay Diversity (CDD) (a time domain equivalent of Phase Diversity (PD)) is an improved version of DD. In particular, CDD addresses the adverse effects of DD by introducing cyclic time delays instead of simply time delays [5]. For OFDM based systems, CDD is the simplest approach for extracting frequency diversity that itself has no built-in diversity. It converts the spatial diversity into frequency diversity by artificially increasing the channel delay spread. However, it requires an outer channel or a FEC facility to benefit from the induced selectivity.
Over the years, the search for optimal transmit diversity schemes for MIMO OFDM systems led to many transmitter diversity processing structures and configurations. All these proposed schemes tackled the problem of achieving the maximum (spatial plus multipath) diversity and coding gain in frequency selective environments. By trading complexity, additional processing and incorporating pre-coding arrangements, it was shown that theoretical diversity limits could be achieved. The most noticeable diversity transmitters in this regard can be found in [6], [7], [8] and [9].
In [6], a MIMO-OFDM scheme with variable multiplexing gains was presented. This scheme traded data rate for full diversity (spatial and multipath) by employing an arbitrary space-time code (STC), and to achieve maximum spatial diversity OFDM sub-carriers were encoded. On top of this, an outer codec was used for achieving multipath diversity. The amount of frequency diversity is related to the redundancy introduced by this outer codec, making this scheme severely dependent on the outer codec and the number of resolvable multi-paths. Only a fraction of the available frequency diversity could be exploited when considering an affordable rate loss and practical scenarios.
In [7] and [8], linear constellation pre-coding (LCP) based OFDM diversity transmitters were presented. The design of LCP with STC techniques was discussed in [7]. This approach used existing STCs of [3] and [4], and relied on combining these codes with redundant or non-redundant pre-coders. This scheme achieved maximum diversity and coding gain at the expense of spectral efficiency. Another LCP based diversity transmitter was presented in [8]. This scheme did not rely on STC techniques and used digital phase sweeping (DPS) or circular block delay diversity (CBDD), which are the same as CDD or PD. To achieve the full diversity, this scheme was again dependent on the LCP. The design of this LCP has severe implications on realistic channel conditions and restricted the number of diversity braches.
The scheme in [9] used a mapping approach to design full diversity codes from the existing STC techniques for arbitrary power delay profiles, again suffering from severe rate loss for attaining maximum diversity.
Drawbacks of aforementioned techniques include loss of data rate and/or additional transmitter and receiver complexities. Incorporating LCP or some other codecs to extract multipath diversity may not be the best solution. In all wireless and mobile communication systems channel or FEC coding techniques have become an integral part. These techniques can provide a much simpler and cost effective solution in extracting the frequency diversity in broadband scenarios. We have realised that a hybrid of STC schemes and CDD may offer an improved diversity transmitter and method measured in terms of performance, cost and complexity for multi-carrier systems.
WO 03/015334 (Hottinen) discloses a diversity transmitter for use in CDMA systems. The transmitter applies fixed complex weights in the frequency domain to symbols to be transmitted. Hottinen's scheme is not suitable for use in systems that employ OFDM for broadband, as it requires additional processing at the transmitter. Hottinen's scheme would require significant modification to be useful in OFDM systems.
SUMMARY OF THE INVENTION
Preferred embodiments of the present invention are based on the insight that in a broadband multi-carrier system it is possible to improve performance by utilising diversity coding techniques to extract spatial diversity, and at the same time to use cyclic time delays to improve frequency diversity in the broadband channel.
It is an aim of at least preferred embodiments of the present invention to provide an improved and less complex diversity transmitter and a transmission method for OFDM based systems, in which the drawbacks of complexity and spectral efficiency are mitigated.
According to the present invention there is provided a diversity transmitter for use in an OFDM transmission protocol which diversity transmitter comprises:
a diversity generator for receiving and diversifying OFDM transmit symbols, and outputting diversified OFDM symbol matrices (DOSM), DOSM symbols within each DOSM being divided into at least two primary streams each comprising different DOSM symbols;
a transmit processor for receiving said at least two primary streams of DOSM symbols, and for transforming said each DOSM symbol from the frequency domain into the time domain, and outputting time domain OFDM symbols (TDOSs); and
a cyclic delay circuit for dividing at least one of said primary streams of TDOSs into at least two branches of identical TDOSs, each branch for supplying a respective spatial channel for transmission to a receiver;
the arrangement being such that, in use, said cyclic delay circuit applies a cyclic time shift to a TDOS in at least one of said branches before transmission. The diversity transmitter may be implemented entirely in software or hardware, or a combination of both. One particular advantage of the present invention is that channel selectivity is improved; more frequency selective channels help the receiver to extract multipath diversity gain in conjunction with channel coding (although with Trellis codes for example channel coding is not mandatory to achieve this advantage). Furthermore the use of additional antenna branches to transmit cyclically delayed replicas of symbols output from the diversity generator does not incur a rate loss. Still further the additional branches of the transmitter do not require any changes at the receiver other than channel estimation to cater for longer impulse responses that are artificially created by the cyclic time shift. Thus the diversity transmitter is very simple to implement. The diversity transmitter can form part of a MISO (multiple input single output) and/or MIMO link.
It will be appreciated that the number of branches in a cyclic delay circuit can be varied (and be different between cyclic delay circuits) according to the channel characteristics where the transmitter is to be used. For example, increasing the number of branches (i.e. the number of cyclic time shifted symbol replicas) can help to make the wideband channel more frequency selective at the carrier frequencies of the OFDM system. For wideband channels that are already highly frequency selective, the use of one or two extra branches enables similar performance with fewer total spatial channels than diversity transmitters that use only space-time coding for example.
Thus the diversity transmitter is very simple whilst achieving good spectral efficiency. Further features are set out in claims 2 to 16 to which attention is hereby directed.
According to another aspect of the present invention there is provided a method of transmitting data in an OFDM system, which method comprises the steps of:
(1) using a diversity generator to receive and diversify OFDM transmit symbols, and output diversified OFDM symbol matrices (DOSM);
(2) dividing DOSM symbols within each DOSM into at least two primary streams each comprising different DOSM symbols;
(3) transforming each DOSM symbol from the frequency domain into the time domain, and outputting time domain OFDM symbols (TDOSs);
(4) dividing at least one of said primary streams of TDOSs into at least two branches of identical TDOSs, each branch for supplying a respective spatial channel for transmission to a receiver; and
(5) applying a cyclic time shift to a TDOS in at least one of said branches before transmission.
Further steps of the method are set out in claims 18 to 29 to which attention is hereby directed.
A diversity transmitter and method according to the invention may bring about some of the following advantages: improvement of performance without any additional complexity at the receiver; increased frequency selectivity for low selective and low delay spread channels; conversion of spatial diversity into frequency diversity assisted by channel coding; spectral efficiency is dependent only on the diversity generator; simple implementation of cyclic time shifts (performance of the cyclic time shift in the time domain eases computational overhead for example); cyclic time shift can be set according to the system guard period; any diversity generator can be used, although full rate STBC are preferred for greater spectral efficiency.
According to another aspect of the present invention there is provided a computer program product storing computer executable instructions for performing the method set out above. The computer program product may be, for example, embodied on a record medium, in a computer memory, in a read-only memory.
There is also provided a diversity transmitter and a transmission method in which there is first channel coding, e.g. by a Turbo/Convolutional codes, the output is modulated, e.g. phase shift keying, the modulated output is subjected to diversification for example STBC, serial to parallel converted, OFDM processed (e.g. inverse fast Fourier transform or inverse discrete fast Fourier transform), parallel to serial converted, each or at least one of the diversified output is subjected to a plurality of at least two branches, in each or at least one branch the symbol sequence is subjected to a cyclic time shift with in each symbol and then transmitted from the parallel spatial channels after insertion of guard period in each branch.
Thus by virtue of the present invention the drawbacks in terms of rate and complexity inherent to known prior art arrangements may be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of how the invention may be put into practice, preferred embodiments of the invention will be described, by way of example only, to the accompanying drawings, in which:
FIG. 1 is a block diagram of an OFDM wireless communication system employing a diversity transmitter according to the present invention;
FIG. 2 is a block diagram of a first embodiment of a diversity transmitter in accordance with the present invention;
FIG. 3 is a block diagram of a second embodiment of a diversity transmitter in accordance with the present invention;
FIG. 4 is a block diagram of a third embodiment of diversity transmitter in accordance with the present invention;
FIG. 5 is a block diagram of a fourth embodiment of diversity transmitter in accordance with the present invention;
FIG. 6 is a graph of BER versus SNR per bit for a computer simulation of another diversity transmitter in accordance with the present invention;
FIG. 7 is a graph of BER versus SNR per bit for a computer simulation of another diversity transmitter in accordance with the present invention;
FIG. 8 is a graph of BER versus SNR per bit for a computer simulation of another diversity transmitter in accordance with the present invention;
FIG. 9 is a graph of BER versus SNR per bit for a computer simulation of various diversity transmitters in accordance with the present invention at two different channel orders;
FIG. 10 is a graph of BER versus SNR per bit for a computer simulation of a diversity transmitter in accordance with the present invention and transmitter using STBC; and
FIG. 11 is a graph of BER versus SNR per bit for a computer simulation of a diversity transmitter in accordance with the present invention and a transmitter using a space-time-multipath coding scheme.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 a functional block diagram generally identified by reference numeral 100 shows the basic elements of an OFDM based wireless digital communication system equipped with a diversity transmitter according to the present invention. An information source 101 provides an output that may be either any analog signal, such as audio or video signal, or any digital signal, such as the output of a compact disc player, that is discrete in time and has a finite number of characters. A source encoder 102 converts the output (or “messages”) from the information source 101 into a sequence of binary digits. Ideally, the information source 101 output is represented by as few binary digits as possible. In other words, an efficient representation of the source output that results in little or no redundancy. The process of efficiently converting the output of either an analog or digital source into a sequence of binary digits is called source encoding or data compression.
The sequence of binary digits from the source encoder is passed to a channel encoder 103 that introduces, in a controlled manner, some redundancy in the binary information sequence that can be used at the receiver to overcome the effects of noise and interference encountered in the transmission of the signal through the channel. Thus the added redundancy serves to increase the reliability of the received data and improves the fidelity of the received signal.
The binary sequence at the output of the channel encoder 103 is passed to a symbol mapper 104 (also known as a digital modulator). Since nearly all of the communication channels encountered in the practice are capable of transmitting electrical signals or waveforms, the primary purpose of the digital modulator is to map the binary information sequence into signal waveforms.
The mapped bits or symbols are then sent for diversification in a diversity generator 105 which generates OFDM symbols for transmission. Following that a guard period 106 is added to each OFDM symbol to reduce intersymbol interference (ISI). Finally each OFDM symbol is transmitted from a respective antenna 107 .
When multiple transmit antennas (i.e. at least two) are used for the purpose of achieving spatial diversity, then the combination of the diversity generator 105 and the multiple antennas 107 can be called a diversity transmitter. The hardware for implementing a diversity transmitter comprises: a baseband processing unit with outputs for each antenna; at least one amplifier before and/or after up-conversion for each antenna; one or more RF up-conversion block (usually performed in steps with several blocks); and at least two antennas. The baseband processing unit comprises: ROM storing data processing algorithms (described in greater detail below) for processing the incoming symbol stream from the symbol mapper 104 ; RAM for buffering the incoming symbol stream; Application Specific Integrated Circuits (ASICs) and/or Digital Signal Processors (DSPs); and data buses for handling movement of data through the baseband processing unit. The incoming symbol stream is processed and handled at a symbol level by the ASICs and/or DSPs, as well as the ROM, RAM and data buses.
Functionally, the diversity generator 105 comprises a spatial diversifier 108 and a cyclic delay diversifier 109 . The spatial diversifier 108 comprises a diversifier 110 that implements space time coding and produces multiple outputs depending on the type of block or trellis coding used. Each output is subjected to multi-carrier (MC) modulation (also known as OFDM processing) by a transmit processor comprising three blocks: serial to parallel converter 111 , IFFT 112 and parallel to serial converter 113 to generate ODFM symbols. The transmit processor is, in a functional sense, between the spatial diversifier 108 and the cyclic delay diversifier 109 ; physically the transmit processor may form part of the aforementioned baseband processing unit. The principle of multi-carrier modulation is to map a serial high rate source stream onto multiple parallel low rate substreams and to modulate each substream on another subcarrier. Since the symbol rate on each subcarrier is much less than the serial source symbol rate, the effects of delay spread significantly decrease, reducing the complexity of the equalizer. OFDM is a relatively simple technique to bandwidth-efficiently modulate multiple subcarriers by using the digital signal processing as IFFT or IDFT on the transmit side and FFT or DFT at the receiver side. One of the main design goals for an MC transmission scheme based on OFDM in a mobile radio channel is that the channel can be considered as time-invariant during one OFDM symbol and that the fading per subcarrier can be considered as flat. Thus, the OFDM symbol duration should be smaller than the coherence time of the channel, and the subcarrier spacing should be smaller than the coherence bandwidth of the channel. By fulfilling these conditions, the realization of relatively simple receivers is possible.
After the OFDM processing each OFDM symbol is replicated on multiple branches for cyclic delay processing by cyclic delay circuits 114 , 115 . Each cyclic delay circuit 114 , 115 comprises at least two branches, OFDM symbols in one or more branch being cyclically rotated (i.e. applies a cyclic time shift) in a controlled manner as more fully described below. The functionality of the cyclic delay circuits 114 may be implemented in the digital baseband domain using one or more Field Programmable Gate Array (FPGA) in the baseband processing unit. Finally, a guard period is added to each cyclically rotated OFDM symbol to mitigate inter symbol interference (ISI) and the signals are transmitted from the antennas 107 .
A receiver 120 receives the signals via an antenna 121 . The receiver 120 processes the received signals in a reverse manner, starting with guard period removal, serial to parallel conversion, FFT processing, back to serial and finally fed to decoders. First a space time decoder 122 , then a demodulator 123 processes the channel corrupted signal and reduces the waveforms to a sequence of numbers that represent estimates of the transmitted data symbols. The sequence of numbers is passed to a channel decoder 124 , which attempts to reconstruct the original information sequence from knowledge of the code used by the channel encoder and the redundancy contained in the received data. A measure of how well the demodulator 123 and channel decoder 124 perform is the frequency with which the errors occur in the decoded sequence. More precisely, the average probability of bit-error at the output of the channel decoder 124 is a measure of the performance of the demodulator-decoder combination. In general the probability of error is a function of code characteristics, the types of waveform used, the diversification employed (space-time block or trellis and combination of cyclic delay diversity), the transmit power, the wireless channel, the noise at receiver, the nature of interference, number of transmit and receive antennas, etc., and the method of demodulation and decoding.
Finally, for an analog output, a source decoder 125 accepts the output sequence from the channel decoder 124 and from the knowledge of source encoding method used, attempts to reconstruct the original signal from the information source 101 .
In the diversity transmitter and method according to the present invention there are multiple parallel transmissions out of at least three spatial channels (which may be antennas or beams) and preferably four or more. Out of the at least three parallel channels at least one of the said spatial channel is shifted by a cyclic shift, the cyclic shift being a fraction/multiple of the system guard period. There may be at least three (logical) parallel channels at a given receiver, although the invention does not place any structural requirements on the receiver.
FIG. 2 shows a generic block diagram of the diversity transmitter. Transmissions out of antennas (representing an example of spatial channels) X 11 , L, X 1M , L, X P1 , L, X PM are experiencing the influence of respective transmission channels h 11 , L, h 1M , L, h P1 , L, h PM before reception at a receiver. In general, an OFDM symbol sequence/vector/matrix s to be transmitted is processed at the transmitter, transmitted via the transmission channels and received at the receiver, where it is subjected to reception processing in order to reconstruct the initially transmitted signal. Reception processing involves channel estimation in order to compensate for the influence of the transmission channels. (Note that the symbol s as well as the transmission channels, i.e. channel impulse response a thereof, are in matrix notation).
Referring to FIG. 2 , a diversity transmitter generally identified by reference numeral 10 comprises a transmit symbol input 1 for inputting OFDM transmit symbols (symbol matrix or a sequence of symbols) into a diversity generator 2 . The transmit symbol input 1 is the output from a channel encoder and symbol mapper (modulator) in the form of a channel coded sequence. The channel coded sequence may be generated by Turbo coding, convolutional coding, block coding, or Trellis coding for example, and the symbol mapper may employ phase shift keying or quadrature amplitude modulation for example. The diversity generator 2 facilitates diversity using orthogonal transmit diversity (OTD) or any other diversity mechanism by applying a generator (e.g. a generator matrix) to each OFDM transmit symbol sequence/matrix and outputs a stream of diversified OFDM symbols s each of size N where N is the number of sub-carrier frequencies in the OFDM system. The stream of diversified OFDM symbols is supplied to a transmit processor 3 a where the stream is divided into P primary streams. As shown in the FIG. 1 , first diversified OFDM symbol s 1 is supplied to a transmit processor 31 , while the pth diversified signal s P is supplied to a transmit processor 3 P. The processor 3 a converts each OFDM symbol from the frequency domain into the time domain by inverse fast Fourier transform or inverse discrete Fourier transform i.e. OFDM processing, and outputs P time domain OFDM symbols. Each of the P primary streams is input to a respective cyclic delay circuit 41 . . . 4 P. Each cyclic delay circuit 41 . . . 4 P comprises M branches, each branch having a copy of the respective time domain OFDM symbol output by the transmit processor 3 a . Furthermore each branch m comprises a respective transmit antenna X 11 , L, X 1M , L, X P1 , L, X PM . In use each cyclic delay circuit 41 . . . 4 P applies a cyclic time shift to some of the time domain OFDM symbols using a cyclic delay matrix Cd m . The cyclic delay matrix Cd m effects a shift of δcy m samples of the time domain OFDM symbol modulo the total number of samples in a time domain OFDM symbol. The effect of this cyclic time shift is to increase the overall delay spread of the channel, at the receiver, as explained in greater detail below.
Each cyclic delay circuit 41 . . . 4 P applies a cyclic time shift to one or more copies of the time domain OFDM symbol s on its M branches. For example the cyclic delay circuit 41 of FIG. 1 receives symbol x on both branches. The upper branch applies δcy m =0 (i.e. no time delay), whereas the lower branches applies δcy m . This generates two output OFDM symbols: x 11 to be transmitted from antenna X 11 and x 12 to be transmitted from antenna X 12 . The same procedure takes place at the other cyclic delay circuits 42 . . . 4 P on the other time domain OFDM symbols. After this processing and addition of the usual guard period (or cyclic prefix) all OFDM symbols are transmitted substantially simultaneously from the antennas X 11 , L, X 1M , L, X P1 , L, X PM . It will appear to the receiver that the signal comes from only P antennas, each with longer channel impulse responses, despite the fact that PM antennas have been used for transmission. To extract this multipath diversity reliance is placed on channel coding techniques (e.g. convolutional codes), already part of many system standards. If a STTC encoder is used as the diversity generator 2 , reliance on channel coding to extract the multipath gain is not necessary.
The cyclic delay matrix Cd m takes the form:
Cd
m
=
[
0
I
(
m
-
1
)
(
L
+
1
)
I
N
-
(
m
-
1
)
(
L
+
1
)
0
]
,
m
∈
[
1
,
M
]
where I A is the identity matrix of order A×A, N is the number of sub-carrier frequencies in the OFDM system, M is the total number of branches in the cyclic delay circuit 41 . . . 4 P where Cd m is to be applied, and (L+1) is number of non-zero taps assumed in the channel transfer function. The transmitted OFDM symbols from different antennas are cyclically delayed replicas of each time domain OFDM symbol. Furthermore the construction of the cyclic delay matrix Cd m ensures that the delay applied to each OFDM symbol on the first antenna of each stream p is zero i.e. the original diversity encoded OFDM symbol is transmitted. Cyclically delayed versions are transmitted from the other antennas at the same time.
In FIG. 2 each cyclic delay circuit 41 . . . 4 P is identical to the others and cyclic delay matrix Cd m effects only the lower branches (M≧2) in each circuit. Each cyclic delay circuit 41 . . . 4 P can have differing numbers of branches. Alternatively, cyclic delay matrix Cd m may be used in the upper branch instead of the lower branch or in any number of branches. The symbols sequence/matrix s needs to be defined differently depending upon the diversity generator used. This will be explained in greater detail with reference to FIG. 3 .
Referring to FIG. 3 a diversity transmitter generally identified by reference numeral 20 comprises four spatial channels X 11 , X 12 , X 21 , X 22 i.e. both P, M=2 (transmit antennas) with the transmit symbol input 1 and the diversity generator 2 generally similar to those described in connection with FIG. 1 . The diversity generator 2 is a full rate space-time block encoder such as that described in [2]. A first diversified OFDM symbol s 1 is supplied to a transmit processor 31 , while a second diversified OFDM symbol s 2 is supplied to a transmit processor 32 . As the symbols s 1 and s 2 belong to the space-time block code matrix, they become s 1 =(c 1 c 2 ) and s 2 =(−c 2 *c 1 *) (or any combination of two OFDM symbols with orthogonal structure), where c 1 and c 2 are complex OFDM symbols and c* represents the complex conjugate of symbol c. The complex OFDM symbols are separable (in fact orthogonal) due to the properties of space-time block codes. Note that in this case the symbol rate remains at 1 since it takes two time intervals to transmit two symbols due to the properties of STBC. However, the diversity order is doubled.
When considering diversification with some other technique for example, STTC one needs to define the symbols s differently depending upon the memory order of the trellis encoder (see [4] for example).
Next the transmit processor 3 a converts the OFDM symbols streams s 1 and s 2 from the frequency domain to the time domain (‘OFDM processing’) e.g. using an IFFT, and outputs two time domain OFDM symbols: c 1 followed by −c 2 * on stream p=1, and c 2 followed by c 1 * on stream p=2. Following this the time domain OFDM symbols in each stream are forwarded to respective cyclic delay circuits 41 , 42 , where they are processed by the cyclic delay matrices Cd m as follows. At time t=0, symbol c 1 is given a cyclic shift of δcy 1 =0 on branch m=1, and a cyclic shift of δcy 2 =16 samples on branch m=2 of the cyclic delay circuit 41 . At the same time symbol c 2 is given a cyclic shift of δcy 1 =0 on branch m=1, and a cyclic shift of δcy 2 =16 samples (assuming the guard period of the considered OFDM system is 16 samples) on branch m=2 of the cyclic delay circuit 42 . At time t=1, symbol −c 2 *; is given a cyclic shift of δcy 1 =0 on branch m=1, and a cyclic shift of δcy 2 =16 samples on branch m=2 of the cyclic delay circuit 41 . At the same time symbol c 1 * is given a cyclic shift of δcy 1 =0 on branch m=1, and a cyclic shift of δcy 2 =16 samples on branch m=2 of the cyclic delay circuit 42 . This results in the following symbols being transmitted from the diversity transmitter 20 at times t=0 and t=1:
X11
X12
X21
X22
t = 0
c 1
c 1 · δcy 2
c 2
c 2 · δcy 2
t = 1
−c 2 *
−c 2 * · δcy 2
c 1 *
c 1 * · δcy 2
The choice of cyclic time shift is purely dependent on the channel memory (number of resolvable multipath components or taps). As the channel memory is assumed not known at the diversity transmitter, it can be compensated with the guard period of the OFDM system. The guard period (or cyclic prefix) is used in OFDM systems to compensate for the delay spread of the channel and helps to reduce intersymbol interference (ISI). Thus the magnitude of the cyclic time shift (or delay) may be chosen as a function of the guard period. For example in the Hiperlan II standards the number of OFDM sub-carriers is 64 and a compulsory guard period of 16 samples is prescribed. When considering the diversity transmitter of FIG. 2 for Hiperlan II standards the cyclic delay matrices Cd 2 should shift each OFDM symbol in the lower branch m=2 by 16 samples; the cyclic shift neither increases the length of the subject OFDM symbol nor increases compulsory guard period of the system. The cyclic shift effects a shift of the OFDM symbol in the time domain that appears to the receiver as a multipath component (and therefore useable to obtain a diversity gain).
When considering more than two branches in each cyclic delay circuit 41 . . . 4 P, the cyclic delays are chosen as multiple of guard period on successive parallel branches. This will be explained with reference to FIG. 4 .
Referring to FIG. 4 a diversity transmitter generally identified by reference numeral 30 generally similar to the diversity transmitter 10 , comprises six spatial channels X 11 , X 12 , X 13 , X 21 , X 22 , X 23 with a full rate STBC as the diversity generator 2 . The diversity generator 2 generates P=2 diversified OFDM symbol streams each of which is input to a cyclic delay circuit 41 and 42 respectively. Each cyclic delay circuit 41 , 42 comprises M=3 branches and thus there are six spatial channels in total.
In each cyclic delay circuit 41 , 42 the time domain OFDM symbols are operated on by a respective cyclic delay matrix Cd m . The cyclic delay matrices Cd m in each cyclic delay circuit 41 , 42 cyclically shift each time domain OFDM symbol by a different number of samples. The difference between cyclic time shift(s) in each branch of cyclic delay circuits 41 , 42 is a maximum by which is meant that the shift in samples should be such that the symbols transmitted from the different spatial channels should not overlap, whereby the receiver sees longer impulse responses coming from the respective primary stream p, no matter how many branches there are in the corresponding cyclic delay circuit. This can be achieved by choosing the cyclic time shift (in samples) as different multiples of the system guard period in successive branches in each cyclic delay circuit 41 , 42 .
Taking the Hiperlan II example, the cyclic shift in each of upper branch of each cyclic delay circuit 41 , 42 is zero i.e. no cyclic shift; and the original diversified and OFDM processed symbol is transmitted; in second branch of both cyclic delay circuits 41 , 42 the cyclic delay matrices Cd 2 apply a cyclic shift δcy 2 =16 samples; lastly, in third branches in both cyclic delay circuits 41 , 42 the cyclic delay matrices Cd 3 apply a cyclic shift δcy 3 =2.δcy 2 =32 samples. This results in the following symbols being transmitted from the diversity transmitter 30 at times t=0 and t=1.
X11
X12
X13
X21
X22
X23
t = 0
c 1
c 1 · δcy 2
c 1 · δcy 3
c 2
c 2 · δcy 2
c 2 · δcy 3
t = 1
−c 2 *
−c 2 * · δcy 2
−c 2 * · δcy 3
c 1 *
c 1 * · δcy 2
c 1 * · δcy 3
Any combination of P and M can be used. This will be explained with an example with reference to FIG. 5 .
Referring to FIG. 5 a fourth embodiment of a diversity transmitter generally identified by reference numeral 40 generally similar to diversity transmitter 30 (like reference numerals indicate like parts), comprises six spatial channels X 11 , X 12 , X 21 , X 22 , X 31 , X 32 and a diversity generator 2 that uses sporadic or half rate STBC. In the diversity transmitter 40 the six spatial channels are provided with a combination of P=3 and M=2, rather than P=2 and M=3 of transmitter 30 .
To assess the performance of the diversity transmitters 10 , 20 , 30 and 40 , a computer simulation based on the HIPERLAN 2 Standards (see [10]) was carried out to examine Bit Error Rate (BER). The following results show BER versus SNR per bit (defined as the transmitted bit energy over the noise power spectral density (E b /N 0 )). A total bandwidth of 20 MHz with 64 sub-carriers and a guard period of 16 samples was used to counteract ISI. A 64 point IFFT was employed to generate each time domain OFDM symbol as described above. A half rate convolutional encoder (R=½, (133, 171) 8 ) was used for channel encoding, and a soft Viterbi decoder was used for channel decoding. Perfect channel estimation and a Maximum Ratio Combining (MRC) detection scheme was used at the receiver. All of the simulations were performed with one receive antenna. Unless otherwise stated full rate space-time block codes (based on [2]) was used as the diversity generator 2 .
To emphasize the importance of multipath diversity, the simulation used various transmit antenna configurations in the presence of varying channel taps. In all antenna combinations described below, only the number of branches M has been varied. Ignoring the cyclic prefix, the rate achievable with the diversity transmitters is 1 bit/s/Hz using QPSK modulation. The channel taps are independent identically distributed (i.i.d.) complex Gaussian with variance σ 1 2 =1/(L+1); three channel orders L=0, 2, 5 were used. Referring to FIGS. 5 , 6 and 7 (the simulation results for different diversity transmitters with varying channel taps. Referring to FIG. 6 a graph 50 shows the simulation results for a diversity transmitter with three antennas two of which transmit time domain OFDM symbols with δcy 1 =0 and the other with δcy 2 =16. For a given E b /N 0 the BER can be seen to improve with increasing channel taps; this is as expected and results from the increased multipath diversity with more channel taps. Referring to FIG. 7 a graph 60 shows the simulation results for a diversity transmitter with four antennas P=2 and M=2; one branch in each of the two cyclic delay circuits applies a cyclic delay of δcy 2 =16 samples. Comparing graph 60 with graph 50 it will be seen that approximately the same BER rates can be obtained with three antennas when L=5 as with four antennas when L=2. The graph 60 supports the conclusion that addition of one more cyclic delay chain gives better performance even with less number of multipaths available in the channel.
Referring to FIG. 8 a graph 70 shows the simulation results for the diversity transmitter 40 i.e. with six antennas and P=2 and M=3. Again the further improvement in BER for a given E b /N 0 is apparent. In particular comparing graph 50 with graph 70 it will be seen that approximately the same BER rates can be obtained with three antennas and L=5, as with six antennas (P=2 and M=3) when L=0 i.e. only one signal path. Accordingly, for different channel scenarios it is possible to increase the number of branches M where naturally occurring multipath is limited, without increasing complexity at the receiver.
Referring to FIG. 9 a graph 80 shows the results obtained for a diversity transmitter with combinations of P and M as follows: P=2 and M=1 (three antennas in total i.e. for branch p=1, M=1 and for branch p=2, M=2); P=2 and M=2; and P=2 and M=4; all at L=0, 6 respectively. It is readily seen how increasing the number of cyclic delay branches M improves BER. This effect is yet further enhanced when the number of channel taps L (i.e. multipath) is increased.
Following the first simulation, an 18-tap Rayleigh channel model corresponding to a typical large open space environment in Non Line of Sight (NLOS) conditions was further used to compare the diversity transmission method to the following earlier proposals: (1) the space-time block encoding scheme of [3], and (2) the space-time-multipath scheme proposed in [8]. The 18-tap model has an overall and average rms delay spread of 730 ns and 100 ns respectively. The channel taps were generated using the model in Jakes [11].
Referring to FIG. 10 a graph 90 shows the results of comparison (1). In particular the BER curves are plotted against E b /N 0 for ST-block codes of [3] with two, four and six antennas respectively. The diversity transmitter of the present invention had the following combinations: P=2 and M=1; P=2 and M=2; and P=2 and M=4. 16-QAM was used to compensate for the rate loss as reported in [3] when four and six antennas were simulated for STBCs; for all other simulations QPSK was used. It is immediately apparent that all of the simulated diversity transmitters according to the invention outperform the best performance available with ST-block codes.
Referring to FIG. 11 a graph 100 shows the results of comparison (2). The space-time-multipath (STM) scheme was simulated with ½ rate convolutional codes with QPSK modulation; this makes the rates of the diversity transmission method of the invention and the STM scheme the same. According to the STM scheme employing four transmit antennas requires 64 sub-carriers as the model has a delay spread of 16 samples. Therefore STM becomes sub-optimal for more than four transmit antennas. The diversity transmitter of the present invention was simulated in the following combinations: P=2 and M=1 i.e. three antennas in total (for branch p=1, M=1 and for branch p=2, M=2), and P=2 and M=2. The present invention outperforms STM scheme in both cases.
The spectral efficiency of the transmit scheme according to the present invention depends on the rate of the employed diversity generator 2 . The ST-block codes for more than two diversification branches P>2 and complex signals suffer from a half or sporadic rate loss [3]. Loss in spectral efficiency makes the diversity transmitter of FIG. 4 less desirable and it is preferred that full rate STBC with any number of cyclically delayed branches are used. However, there is no limitation in using any diversity generator for better performance by trading spectral efficiency.
The diversity transmitter may be part of a mobile terminal or a base station for example, and the receiver may be a base station or another mobile terminal. Alternatively the diversity transmitter may be part of a broadcast transmitter such as a digital broadcast transmitter (e.g. DVB). Furthermore, the spatial channel may include polarization diversity channels. Some of the branches can have different cyclic delays and may provide a different quality of service and performance. There may be different channel coding, different diversity generators and even parallel transmission with necessary changes to the receiver.
The diversity generator may be adapted to subject said diversified OFDM symbol matrices to at least one of orthogonal transmit diversity (OTD), orthogonal space-time block code (STBC) processing, non-orthogonal STBC processing, space-time Trellis code (STTC) processing, or space-time turbo code processing.
Whilst the present invention is presented in terms of a comparatively simple OFDM transmission protocol, it is applicable to all OFDM based systems such as: Orthogonal Frequency Division Multiple Access (OFDMA); multi-carrier code division multiple access (MC-CDMA); MC direct-sequence CDMA (MC DS-CDMA); multitone CDMA (MT-CDMA); orthogonal MC DS-CDMA and MC DS-CDMA system with no sub-carrier overlapping, etc.
DOCUMENTS MENTIONED IN THE SPECIFICATION
[1] H. Bölcskei and A. Paulraj, “Space-frequency coded broadband OFDM systems,” Wireless Commun. Networking Conf., Chicago, Ill., pp. 1-6, Sep. 23-28, 2000.
[2] S. M. Alamouti, “A simple transmit diversity technique for Wireless Communications,” IEEE Journal on Selected Areasin Communications Vol. 16, pp. 1451-1458, October 1998.
[3] V. Tarokh, H. Jafarkhani and A. R. Calderbank, “Space-time block codes from orthogonal design,” IEEE Transactions on Information Theory, Vol. 45, pp. 1456-1467, July 1999.
[4] V. Tarokh, N. Seshadri and A. R. Calderbank, “Space-time codes for high data rate wireless communication: Performance criterion and code construction,” IEEE Transactions on Information Theory, Vol. 44, pp. 744-765, March 1998.
[5] A. Dammann and S. Kaiser, “Standard conformable antenna diversity techniques for OFDM and its application to DVB-T system,” IEEE Global Telecommunications Conference (GLOBECOM 2001), pp. 3100-3105, November 2001.
[6] H. Bölcskei, M. Borgmann and A. Paulraj, “Space-frequency coded MIMO OFDM with variable multiplexing-diversity tradeoff,” International Conference on Commun. (ICC), pp. 2837-2841, May 2003.
[7] Y. Xin, Z. Wang and G. Giannakis, “Space-time diversity systems based on linear constellation precoding,” IEEE Trans. on Wireless Commun., vol. 2, pp. 294-309, March 2003.
[8] X. Ma and G. Giannakis, “Space-time-multipath coding using digital phase sweeping or circular delay diversity,” to appear in IEEE Trans. Signal Processing, 2004.
[9] W. Su, Z. Safar, M. Olfat and K. J. Ray Liu, “Obtaining full-diversity space frequency codes from space-time codes via mapping,” IEEE Trans. on Signal Processing, vol. 51, NO. 11, November 2003, pp. 2905-2916.
[10] European Telecommunications Standard Institute ETSI, “Broadband Radio Access Networks (BRAN); HIPERLAN Type 2; Physical Layer”, V1.1.1 (2000-04)
[11] W. C. Jakes “Microwave Communications”, Wiley, 1974. | A diversity transmitter for use in an OFDM transmission protocol which diversity transmitter comprises:
a diversity generator ( 2 ) for receiving and diversifying OFDM transmit symbols, and outputting diversified OFDM symbol matrices (DOSM), DOSM symbols within each DOSM being divided into at least two primary streams each comprising different DOSM symbols, a transmit processor for receiving said at least two primary streams of DOSM symbols, and for transforming said each DOSM symbol from the frequency domain into the time domain, and outputting time domain OFDM symbols (TDOSs), a cyclic delay circuit ( 41 . . . 4 P) for dividing at least one of said primary streams of TDOSs into at least two branches of identical TDOSs, each branch for supplying a respective spatial channel for transmission to a receiver, the arrangement being such that, in use, said cyclic delay circuit ( 41 . . . 4 P) applies a cyclic time shift to a TDOS symbol in at least one of said branches before transmission. | 7 |
This invention relates to the production of new turfgrass cultivars of seashore zoysiagrass (Zoysia sinica Hance), an obscure grass species that has never before been commercially developed as turfgrass. Cultivars produced by selective breeding from this species offer advantages in plant density, disease resistance, and turf quality over genetic plant material found in nature.
BACKGROUND
Homeowners and turfgrass managers in the United States rely on fewer than 20 plant species for all their grassing needs. Moreover, nearly all of these 20 grasses originate from the same general region of Eurasia. An estimated 46.5 million acres of turfgrasses are presently grown in the US (Grounds Maintenance magazine, May 1996, p. 10.). Concentrating this few number of species over a vast agricultural landscape is bound to produce problems over time as disease or insect organisms build up and become virulent against existing grasses. This type of pandemic actually occurred in the US in recent years, when large acres of the corn belt were decimated by an outbreak of southern corn leaf blight when a mutated strain of the disease arose.
The solution to this dilemma lies in species diversity. Agriculturists have found that by increasing the number and breadth of species, there is increased genetic diversity and less chance that a particular parasite will devastate a substantial acreage of plants.
Another factor urgently needed is diversity in where species originate. Most of the common turfgrasses grown in this country--Kentucky bluegrass (Poa pratensis L.), creeping bentgrass (Agrostis stolonifera L.), fine fescue (Festuca spp.), tall fescue (F. arundinacea Schreb.), and perennial ryegrass (Lolium perenne L.)--species that comprise the bulk of turf in the temperate zone--derive from the same region of Europe. Only one turfgrass species originates from here in North America (Buchloe dactyloides [Nutt.] Engelm.) and only two from Eastern Asia (Zoysia japonica Willd. and Eremochloa ophiuroides [Munro.] Hack). To increase the breadth of genetic origin, more turfgrasses are needed that originate from a broader sector of world geography, to bolster the diversity of today's turfgrasses.
Another advantage of seeking out additional turf species is to help reduce turf maintenance levels. Present-day turfgrasses are better suited to high maintenance than low. They perform best when given a steady diet of water, fertilizer, and chemical pesticides. In theory, grasses native to a particular locale should be able to withstand local growing conditions better than exotics, without the need for additives and preservatives. Grass species that can survive on less input of water or other scarce natural resources offer benefits for reducing maintenance and improving environmental friendliness of lawns.
But finding and developing new grass species from nature is difficult, time consuming, and expensive. The developer must sift through thousands of prospective grasses listed in botanical literature, identify promising grasses, and travel thousands of miles to locate, isolate, identify, transport, quarantine, grow, test, and breed these grasses. This process can take more than 10 years to develop acceptable cultivars. Furthermore, as it turns out, most prospective grasses in nature have no commercial turf value, due to their inability to generate an acceptable ground cover when mowed. The vast majority of natural grasses cannot produce a plush lawn under continuing defoliation.
Also, few grasses found in nature have the ability to produce marketable quantities of seed--a critical necessity for commercialization of a new grass species. Raw germplasm of most native grasses seldom tops 100 lbs. per acre in seed production (R. S. Sadasivaiah and J. Weijer, 1981, The utilization of native grass species for reclamation of disturbed land in the alpine and subalpine regions of Alberta. In Reclamation in mountainous areas. Proc. 6th ann. meeting Can. Land Reclam. Assoc.); this level of production is not high enough for economic viability. By contrast, popular grasses like tall fescue have been cultivated and selected since prehistoric times for cattle fodder. Only high yielding plant lines have persisted through the ages. Many of today's tall fescue cultivars top 1 ton per acre in seed production.
Yet another complexity facing the plant developer is the unresponsiveness of many wild grasses to plant breeding. The vast majority of wildland grasses lack genetic potential for refinement into desirable turfgrass cultivars. Only after considerable investment in collection and breeding does the developer discover which grass species can be successful bred and which cannot.
Eastern China is the center of origin for three zoysia species: Z. japonica, Z. sinica, and Z. macrostachya. Zoysia japonica, commonly known as Japanese zoysia, is a popular turfgrass in the Asia Pacific Rim countries and in the US mid-Atlantic region. Several vegetatively propagated cultivars have been developed from this species, including `Meyer,` `El Toro,` `Belair,` and `Midwest.` All of these cultivars are clonally propagated by means of vegetative cuttings. Only in recent years has there been effort to develop seeded cultivars of Z. japonica, due to the fact that breeding of the species is slow and tedious (S. H. Samudio, 1996, Whatever became of the improved seeded zoysia varieties? Golf Course Mgmt. August 1996, p. 57-60). Only two seeded Z. japonica cultivars, `W3-2` and `Zenith,` have been sold commercially.
To date, Zoysia sinica Hance and Zoysia macrostachya Franch. et Sav. have never been commercially developed. In China and its neighboring countries, these two grasses are native to the seashore. They are found along coastal plains with seawater often washing their roots. Scientists have speculated that these two grasses may be halophytes--plants that actually require salt as part of their metabolism (K. B. Marcum, M. C. Engelke, and S. J. Morton, 1993, Salt tolerance and associated salt gland activity of zoysiagrasses, Agronomy Abstr., Amer. Soc. Of Agronomy, Madison, Wis.). Hence, these species hold the potential for soil stabilization in areas of high salt soils or saline irrigation water. More and more, salt intrusion is becoming a concern in many areas of the US, including Florida, Texas, and most of the West.
Zoysia sinica has no common (English) name. Therefore, the name "seashore zoysiagrass" is proposed for this species to designate its seaside origins.
Vegetatively, seashore zoysiagrass is quite similar in appearance to Japanese zoysia. The main differentiating point is seed length. Seed of Z. sinica are about twice as long as those of Z. japonica, making identification possible even with a single seed.
Quantities of Chinese common zoysia seed have been produced and imported into the US in recent years. While most of this seed is Z. japonica, a minute amount is Z. sinica and Z. macrostachya. Chinese zoysia seed is hand-harvested in the wilds, throughout mountains and along the seashore. Although the harvesters are pursuing the much-sought-after Z. japonica seed, they sometimes inadvertently harvest patches of Z. sinica or Z. macrostachya. Hence, a small amount of Z. sinica makes its way into this country each year, albeit incognito.
Dong and Chen (L. S. Dong and B. X. Chen, 1991, Zoysia germplasm resource investigation in the Jiaozhou Bay, Qingdao Lawn Construction Development Co., Qingdao, Shandong, PRC) characterize Z. sinica as:
Root-shaped creeping stems, and height of 7-15 cm, thread-shaped coniferous leaves with hard textures and a length of 3-7 cm and a width of 3 mm. The leaf edges bent inward with long soft hairs around the leaf sheath, the ligule is a circle with long soft hairs, the total ear length is 3-4 cm and the width, 2 mm. The spikelet is light purple with a length of 3-4 cm and a width of 1.5 mm and coniferous leaves. The stem of the spikelet is 1-2 mm. The blooming stage is May-July and the seed-setting time is July-August.
In Korea, Hong et al. (K. Hong, H. Yeam, and Y. Do, 1985, Studies on interspecific hybridization in Korean lawngrass [Zoysia spp.], J. Korean Soc. of Hort. Sci. 26(2):169-178) describe Z. sinica as being taller growing than Z. japonica. And they found differences between the two species in their natural occurrence. They describe the indigenous habitat of Z. japonica as inland "fields," versus the habitat of Z. sinica as the "slime along the shore." Hong et al. characterized the average seed length of Z. sinica as 5.3 mm, compared to 2.4 mm for Z. japonica. The leaf width of Z. sinica was a finer 2.9 mm, versus 5.1 mm for Z. japonica. They found that Z. sinica was capable of producing viable seed when pollinated with Z. macrostachya, suggesting a genetic connection between the two species.
SUMMARY OF THE INVENTION
The present invention provides for the development of novel cultivars of an obscure grass species never before exploited for turf purposes. Cultivars developed from this species demonstrate enhanced turfgrass properties, as demonstrated in the section to follow, including improvements in mite tolerance, shoot density, fineness of leaf, and overall turfgrass quality.
More specifically, the present invention relates to a Zoysia sinica plant having the characteristics of an average seedhead density of greater than zero.
The present invention further relates to a Zoysia sinica plant having an average shoot density of greater than 0.56 shoots per cm 2 .
The invention further relates to a method of making an F 1 hybrid by crossing the plant of the present invention with another Zoysia sinica plant.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
In the description and tables which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:
Average Shoot Density: As used herein, the term average shoot density means the number of grass shoots measured in four plugs. During the process of blade width measurement, the number of grass shoots for each genotype are counted in the four plugs of a 2 inch×5 inch area. A grass shoot is defined as an autonomous unit possessing a vertical sheath segment, and a minimum of two leaves, including the vertical or bud leaf. Shoot counts per plug are converted numerically into shoots per cm 2 , based on the exact measured area of the plug.
Leaf Color: The term leaf color means the leaf color is evaluated visually on a 1 to 9 integer rating scale, in a manner similar to turfgrass quality. With leaf color evaluation, a rating of 1 would equate to yellow-green turf, 5 to average green turf, and 9 to intensely dark green turf color. Ratings are taken when the turf is actively growing, when regular mowing is taking place, and when no stresses such as drought or disease are apparent.
Seedhead Density: The term seedhead density refers to the relative number of seedheads (inflorescences) expressed under controlled, unmowed conditions. After seedheads, also called inflorescences, protrude, the plants are evaluated on a visual rating scale of 1 to 9, with 1 equal to no visible heads, 5 equal to an average number of seedheads, and 9 equal to an exceptionally high number of seedheads. An analysis of variance is used for differentiating replicates of like plants, using the same type of analysis as for turf quality.
Significant Difference: As used in the tables, the indication of "*", "**", and "***" asterisks indicate significant differences at the p≦0.05, 0.01, and 0.001 levels, respectively.
Stolon Internode Length: The term stolon internode length defines plants that are established in an unclipped, bare-ground, spaced plant nursery, using greenhouse-grown, vegetatively potted plants of at least 6 months of age. The field plants are grown for 3 summer months in a location climatologically similar to Post Falls, Idaho (where the data in this experiment were collected). Stolons (lateral, surface-creeping stems) are permitted to naturally grow. The length of the stolon internode is measured as the distance between two successive nodes once the stolon reaches a length of at least 4 inches. The measurement is taken between the 3rd and 4th nodes, counted inward from the apex of the stolon. Readings are taken in millimeters from the center of one node to the next.
Turfgrass Quality: The term turfgrass quality is determined in the following manner: Grasses are seeded into plots 4 feet×6 feet or 5 feet by 5 feet at a seeding rate (seed grams per square meter) equal to commercial rates listed in turf textbooks. Plots are maintained under fertilization and watering to minimize stress, and at a weekly mowing height of 3/4 inch to 11/2 inch. Four plots of Variety A are planted in a randomized complete block design arrangement with four plots of Variety B. Visual ratings are taken monthly during the growing season on a 1 to 9 rating scale, with 1 equal to bare ground, 2 equal to thin, brown turf, 3 equal to substandard turf, 4 equal to marginally acceptable turf, 5 equal to average turf, 6 equal to slightly above average turf, 7 equal to dense, robust turf, 8 equal to turf of exceptional quality, and 9 equal to ideal turf quality. Only integer values are recorded. Ratings are conducted by a university-trained specialist with a graduate degree in Turfgrass Science. Monthly data ratings are analyzed using a statistical procedure known as the analysis of variance and either a t-test or LSD test, at the 0.05 level of probability. A significant analysis indicates the two varieties, A and B, are different, and that the difference is not due to random error or natural plant and soil variability. A non-significant analysis would indicate that the varieties A and B were indistinguishable in turf quality and could be considered to be identical.
Vegetative propagules: As used herein, the term vegetative propagules means sprigs, plugs, stolons and sod.
Yield Estimate: As used herein the term yield estimate is determined on plants which are grown as previously described for "seedhead density." Yield ratings are based on a combination of factors, including the seedhead density, reproductive length of the seedhead, width of the seedhead. Ratings are based on a 1 to 9 scale with 1 equaling no yield productivity, 5 equaling average productivity, and 9 equaling exceptionally high productivity. An analysis of variance is used for differentiating replicates of like plants, using the same type of analysis as for turf quality.
The novel turfgrass cultivars developed by this invention may be produced by following the detailed descriptions listed below. The process began with identification of species with turfgrass potential through an exhaustive search of the botanical literature. Numerous promising grass species were identified, located, tested, and rejected before Z. sinica were entered into plant breeding. The plant breeding phase of this invention follows conventional breeding methods as outlined in a number of plant breeding textbooks, using a method called modified recurrent selection. The net result of their breeding is a series of cultivars with enhanced turfgrass performance. The improvements instilled into these cultivars are quantifiable and distinctive. Raw germplasm of these species from nature performs poorly as mowed turf, if it survives at all. The enhanced cultivars perform competitively with other popular turf cultivars.
Germplasm collection trips were mounted to Japan in 1987 and to China in 1990, 1991, and 1993 to bring seed of Zoysia sinica back for testing and development. Seed, as opposed to vegetative plant material, was brought into the US to avoid unnecessary quarantine delays. Introduction of seed also avoided the problem of unwittingly importing a virus or insect along with the germplasm.
Following quarantine inspection, imported seed was sprouted in a greenhouse and transplanted to spaced-plant, field observation nurseries near Visalia, Calif., Phoenix, Ariz., Post Falls, Id., and Lakeland, Ga. The latter site proved most satisfactory for propagating and breeding seashore zoysiagrass.
J-14, an improved Z. sinica cultivar, was assembled from superior seashore zoysiagrass clones planted in nurseries near Lakeland, Ga., in 1991 and 1993. During the spring of 1994, 36 clones were moved to an isolated crossing block labeled, 94-0014. Plants were individually harvested in June, 1994. Seed was treated and germination was tested: 16 lines were dropped based on poor germination. Seed from the remaining 20 lines was used to plant a 1200-plant breeder block in August, 1994. In 1995, the plants were still relatively small, but several clones were discarded to increase uniformity; coarse textured, light green, and bluish plants were removed.
During 1996, we determined that some of the lines were actually Z. sinica×Z. japonica interspecific hybrids. These plants were rogued from the breeder block. First breeder seed will be produced in 1997; commercial seed should be available by 1999.
Visual ratings and botanical measurements were taken from the J-14 cultivar and from various unimproved seashore zoysiagrass plants in the nurseries which are plants derived directly from nature without breeding intervention. Data were analyzed using analysis of variance and unpaired t-tests to determine statistical differences between the groups as shown in Tables 1 and 2. The genetic improvements in Z. sinica instilled by the breeder are: 1) Improved seedhead density and seed yielding ability with 2) enhanced turfgrass quality which is a function of the visual attractiveness of the turf; a composite of disease and insect resistance, vigor, density, color, and growth habit, 3) higher shoot density in mowed turf; and 4) a shorter stolon internode length (indicating the plants were better adapted for dense turf conditions).
In Table 1, data is shown on J-14, an improved seashore zoysia (Zoysia sinica Hance) cultivar versus unimproved, raw germplasm collected from nature (Qingdao, China). This spaced-plant nursery near Lakeland, Ga., was planted in May, 1993, and was evaluated through April, 1996.
The common Z. sinica in this table represents means from several sources originating from seed of unimproved Z. sinica landraces collected near Qingdao, China. Unimproved germplasm sources include: 92-124-1, 92-124-2, 92-124-3, 92-124-4, 92-124-6, 92-124-7, 92-125-1, 92-125-2, 92-125-3, 92-127-1, 92-128-1, 92-128-2, 92-128-3, 92-130-1, 92-130-2, 92-132-1, 92-132-2, 92-132-3, 92-132-4, 92-132-5, 92-133-1, 92-133-2, 92-134-1, 92-134-10, 92-134-11, 92-134-2, 92-134-3, 92-134-4, 92-134-5, 92-134-6, 92-134-7, 92-134-8, 92-134-9, 92-135-1, 92-135-10, 92-135-11, 92-135-12, 92-135-13, 92-135-14, 92-135-15, 92-135-16, 92-135-17, 92-135-18, 92-135-9, 92-135-2, 92-135-20, 92-135-21, 92-135-22, 92-135-23, 92-135-24, 92-135-25, 92-135-26, 92-135-27, 92-135-28, 92-135-29, 92-135-3, 92-135-30, 92-135-31, 92-135-32, 92-135-33, 92-135-34, 92-135-35, 92-135-36, 92-135-37, 92-135-38, 92-135-39, 92-135-4, 92-135-40, 92-135-41, 92-135-42, 92-135-43, 92-135-44, 92-135-45, 92-135-46, 92-135-47, 92-135-48, 92-135-49, 92-135-5, 92-135-50, 92-135-51, 92-135-52, 92-135-53, 92-135-54, 92-135-54, 92-135-55, 92-135-56, 92-135-57, 92-135-58, 92-135-59, 92-135-6, 92-135-60, 92-135-61, 92-135-62, 92-135-63, 92-135-64, 92-135-65, 92-135-66, 92-135-67, 92-135-68, 92-135-69, 92-135-7, 92-135-70, 92-135-71, 92-135-72, 92-135-73, 92-135-74, 92-135-75, 92-135-76, 92-135-77, 92-135-78, 92-135-79, 92-135-8, 92-135-80, 92-135-81, 92-135-82, 92-135-83, 92-135-84, 92-135-85, 92-135-86, 92-135-87, 92-135-88, 92-135-89, 92-135-9, 92-135-90, 92-135-91, 92-135-92, 92-135-93, 92-135-94, 92-135-95, 92-135-96, 92-137-1, 92-137-2, 92-137-3, 92-137-4, 92-138-1, 92-138-10, 92-138-11, 92-138-12, 92-138-13, 92-138-2, 92-138-3, 92-138-4, 92-138-5, 92-138-6, 92-138-7, 92-138-8, and 92-139-1.
J-14 was bred from sources collected near Qingdao, China and Centerville, Tenn., including: 91-34, 92-95-3, 92-101-2, 92-108-17, 92-110-10, 92-110-13, 92-110-2, 92-111-1, 92-113-17, 92-120-21, 92-120-22, 92-120-31, 92-120-32, 92-120-8, 92-122-3, 92-123-13, 92-124-5, and 92-138-14.
Visual ratings were based on a 1 to 9 scale where 9=best turf quality, finest leaves, highest yield (based on a combination of number of seedheads per plant and the length of the seedheads), or most seedheads per plant.
TABLE 1______________________________________ Seedhead Yield Leaf Turfgrass density estimate texture quality Group† April 96 April 96 March 96 October______________________________________ 93J-l4 Zoysia sinica 6.6 4.4 5.4 5.4 Common Z. sinica 4.4*** 2.9** 5.8* 3.9**______________________________________
In Table 2, morphological evaluations of J-14, an improved seashore zoysia (Zoysia sinica Hance) cultivar are shown versus unimproved, common Z. sinica landraces from China. Common Z. japonica grown in China from landraces is also included as a reference standard. Plants in this trial were established in Post Falls, Id., as 6-inch plugs in June, 1996; measurements were taken September, 1996. Natural height was measured as the freestanding height of plants without seedheads. Stolon internode length was measured between nodes 3 and 4 from the meristem.
TABLE 2______________________________________ Stolon Natural vegetation internode Group† height (mm) (mm)______________________________________J-14 Z. sinica 144 27 Common Z. sinica 111* 34* Sunrise® brand Chinese common 101* 38*______________________________________
Morphological evaluations of improved Zoysia sinica Hance versus unimproved wild-type Z. sinica are shown in Table 3. Plants in this trial originated from individual sprigs, planted in the field in Post Falls, Id. in June, 1996. Plants were grown through the summer and fall, and on Oct. 10, 1996, 1 inch diameter plugs were removed and planted into 6 inch (15 cm) Promix-filled pots in the greenhouse. The greenhouse air temperature was maintained at an average of 68° F. during the day and 55° F. at night. Soil in the pots was continually warmed to 70° F. using underneath, hot-water heating. Air relative humidity was 55%. Daylight and photoperiod were supplemented with artificial sodium light from 3:45 p.m. to 10:00 p.m. daily. Pots were watered once a day by mist for two minutes. Fertilization was 2.7 lbs. Nitrogen per 1000 ft 2 from Peter's 20-20-20 once a month, and 2 lbs nitrogen per 1000 ft 2 from PFC 18-10-10-7 every three weeks. Plants were not clipped. Measurements were taken Feb. 10, 1997. Statistical differences were based on a total of 19 pots, with data analyzed using unpaired t-tests. Probabilities less than 0.05 are statistically significant.
As shown in Table 3, the average shoot density for the present invention was 0.72 versus the mean of 0.47 for previous Zoysia sinica germplasm. The present invention also had an average seedhead density of 22 and mite tolerance of 64 versus average seedhead density of 0 and mite tolerance of 95 for the unrefined Zoysia germplasm.
TABLE 3______________________________________ Zoysia sinica Zoysia sinica Present Invention Unimproved Standard Standard Avg Deviation Probability n Avg Deviation______________________________________Shoot density 0.72 0.15 .00024 19 0.47 0.09 (shoots/cm.sup.2) Seedhead 22 7 .00000 19 0 0 density (influor- escences per pot) Mite Tolerance 64 16 .00002 19 95 7 (% of total leaves showing mite damage based on 10 leaves per pot Stolon count 1.8 1.6 .00004 19 9.0 3.5 (perpot)______________________________________
DEPOSIT INFORMATION
Zoysia sinica seed of this invention has been placed on deposit with the American Type Culture Collection (ATCC), Manassas, Va. 20110, under Deposit Accession Number, 97951 on Mar. 13, 1997.
Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the appended claims. | A Zoysia sinica turfgrass variety is disclosed. The invention relates to the seeds, the plants, and to methods for producing a Zoysia plant having the characteristic of a seedhead density of greater than zero. | 0 |
STATEMENT OF PRIORITY
[0001] The present patent application claims priority from U.S. Provisional patent application having Ser. No. 61/679,289, filed on Aug. 3, 2012, by Pfahnl et al. and entitled DISPENSING AND ASPIRATING SYSTEM INCLUDING A SYRINGE HOLDING AND ACTUATION DEVICE.
FIELD OF THE INVENTION
[0002] The invention relates generally to systems and methods for controlling the motion of two elements using a compact transmission whose modes of actuation can be easily selected on demand. An example application of the invention includes injecting and/or aspirating fluids using a syringe in combination with a syringe holding and actuation device. More specifically, the present invention relates to such systems and methods in which a holding and actuation device includes a compact transmission to allow a user to easily select the direction of the motion, e.g., an actuating mechanism can be moved forward or in reverse on demand. In the case of fluid delivery, it is possible to switch between the aspiration or dispensing modes of function on demand.
BACKGROUND OF THE INVENTION
[0003] Syringes are available in a variety of sizes and are intended to dispense (inject) as well aspirate (extract) a variety of substances, most often fluids but also dispersions, gels, solids such as powders, or gases. Syringes are used to inject or aspirate fluid in several therapeutic and diagnostic medical procedures such as the following illustrative examples:
1) Centesis Procedures—including Thoracentesis (removal and optional analysis of fluid in the chest, Paracentesis (removal and optional analysis of fluid in the abdomen), Pericardialcentesis (removal and optional analysis of fluid from the pericardial space around the heart), and Arthrocentesis (removal and optional analysis of fluid from a joint). 2) Abscess Aspiration—removal and optional analysis of fluid collection sites common in the body particularly the breast, brain or kidneys. 3) Contrast Media Injection—special fluid to better visualize blood vessels for cardiology procedures. Aspiration is used to verify the needle puncture into a vasculature, and injection is used to deliver the contrast media into the vasculature. 4) Exchange Transfusions—including slow and careful replacement of blood for adult and pediatric blood diseases. 5) Surgical Wound Irrigation—including high velocity cleansing of traumatic injuries. A syringe aspirates saline, for example, from a reservoir and irrigates a wound site.
[0009] The nature of these procedures typically involves extensive manipulation of the syringe and stabilization of the injection/aspiration site. These tasks are more difficult with high viscosity fluids and/or larger syringes.
[0010] Syringes can be manually operated with one or two hands, can be manually operated with the assistance of a holding/actuation accessory, or can be used with a variety of automatic devices which aide in controlling the movement of the substance within the syringe. Automation comes with additional cost, size, and maintenance disadvantages compared to manual activation.
[0011] Larger size syringes, such as 60 mL ones, are common and well-suited for many procedures. However, larger sized syringes are more challenging to use manually with one hand, even when used in combination with conventional actuation accessories. This difficulty could compromise patient safety, delivery and aspiration accuracy, and/or extend procedure times. Having a second person assist in helping resolve these issues increases procedure cost.
[0012] Syringe accessories in the form of hand pieces or devices have been described and developed that address some of the challenges associated with using syringes to accomplish aspiration. A handheld device used with syringes to provide aspiration function is depicted in patents such as U.S. Pat. No. 5,469,860 and USD337821. A commercially available device is available from Inrad, Inc. (Kentwood, Mich.) under the trade designation Aspiration Biopsy Syringe Gun. Several devices also have been described that are used with syringes to dispense syringe contents. See, e.g., USD576273.
[0013] Some syringes include features to assist with single handed aspiration. These features include loops or rings to facilitate finger and thumb action. These features can facilitate both dispensing and aspiration. Several variations of an early control syringe exist. See, e.g., U.S. Pat. No. 4,516,969.
[0014] Commercially available devices with trigger-actuated ratchet mechanisms are used in so-called caulk guns for dispensing adhesives and caulking materials from prefilled cartridges. The guns and cartridges are available in different sizes. Illustrative products are and manufactured by companies such as 3M Co. (St. Paul, Minn.) and Henkel Corp. (Rocky Hill, Conn.). A recent patent US7757904B2 is an example of such a device for caulk cartridges.
[0015] Commercially available bar clamping devices exist that utilize ratchet mechanism principles. Examples are US8074340B2 and U.S. Pat. No. 4,926,722. Some of these clamps can be reconfigured to a spreading bar clamp as described in U.S. Pat. No. 5,009,134. These devices illustrate how high forces can be used to create a clamping or spreading motion. A bar clamp that uses a switching mechanism to select between clamping and spreading functions is described in US7325797B2. A third example device is marketed by Avanca Medical Devices, Inc and described in US7967793B2. This device allows the dispensing and aspiration of a syringe with a single hand. A fourth example is a balloon inflation device that utilizes a threaded plunger that is rotated clockwise or counterclockwise to advance or retract the plunger of a syringe. See, e.g., U.S. Pat. No. 5,057,078.
[0016] There are other applications where it is desired to have an ability to control motion of one or more components and the direction of such motion. Some additional applications involve controlling the motion of a fluid (e.g., to dispense, inject, or aspirate a fluid). Other applications involve controlling the position of one or more solid items.
[0017] Many conventional designs can limit or impede a user from dispensing and aspirating syringes, particularly large sized ones with one hand when one hand operation is desired. Therefore, in light of these challenges, it is desired to have a compact and lightweight device that can provide easy dispensing and aspirating modes when used with a syringe, the ability to switch between the two modes and do all this with one hand if desired without requiring outside assistance or requiring setting the syringe down at any point. It is also desirable that the device be able to provide mechanical advantage so that the user-applied force can be leveraged for very high dispensing or aspiration forces. It also is desired that the device be MRI safe and compatible, since therapeutic and diagnostic procedures using syringes may be conducted under Magnetic Resonance Imaging (MRI).
SUMMARY
[0018] The present invention provides actuation mechanisms that incorporate a transmission assembly that allows the mechanisms to cause actuation in a plurality of transmission modes (e.g, at least one forward transmission mode and at least one reverse transmission mode). The mechanisms preferably are trigger-actuated by hand (i.e., manually) to cause movement of a workpiece in a desired direction. Desired directions can be linear or nonlinear. The same hand used for trigger action can also be used to change transmission modes in many modes of practice, even while using substantially the same grip used for trigger actuation. In other instances, actuation can be automated rather than manual. The transmission assembly is compact, elegantly simple in design, easy to manufacture and assemble, and easy to use (even with one hand if desired) to switch between transmission modes on demand. The actuation mechanism is useful in any application in which it is desired to move a workpiece, which can be a solid, liquid, or gas, in multiple directions, e.g., forward and reverse, gripping and releasing, etc. Exemplary uses include actuating syringes, actuating caulk cartridges, actuating mechanical clamps, actuating vacuum gripping devices, actuating furniture componentry to change the configuration of furniture (e.g., raising and lowering the height of a chair seat or changing the angle of a desk top), actuating toy water guns, actuating spray containers, and the like.
[0019] For example, the present invention provides systems and methods in which a syringe actuation device is coupled to and then used with a syringe to aspirate or dispense, on demand, the syringe. In preferred modes, trigger actuation is used to operate the syringe. Using the transmission assembly to select the desired transmission mode, the same trigger action can be used both to dispense and aspirate syringe contents as desired. Advantageously, actuation and switching between dispensing and aspiration modes can be accomplished with one hand. In illustrative embodiments, the actuation devices of the present invention include a configurable transmission assembly that couples an actuation force to different motions of a syringe carriage. In one mode, the carriage actuates the syringe in a dispensing mode in which syringe contents are dispensed. In another mode, the carriage actuates the syringe in an aspiration mode to draw material into the syringe.
[0020] The present invention offers numerous advantages over other syringe dispensing and aspiration devices. In many embodiments, the devices are made of materials that allow the devices to be used in diverse environments including with Magnetic Resonance Imaging equipment. For example, representative embodiments can be made of non ferrous materials including plastics that are suitable for use in procedures that also involve use of Magnetic Resonance Imaging equipment, which creates a strong magnetic field around the patient.
[0021] Preferred embodiments allow, if desired, single-handed aspiration and dispensing of even very large syringes that otherwise would have a large plunger stroke or require much actuation force. Furthermore, an ergonomically designed and placed clutch of a configurable transmission system allows the same hand performing the aspiration and dispensing to also switch between these two modes without requiring a second hand or having to set the device down. Other preferred embodiments may remove or add features of the clutch and configurable transmission system to create aspiration only versions of the invention, or dispensing only versions, or ones with a neutral position (neither aspirating or dispensing).
[0022] In one aspect, the present invention relates to a syringe actuation system, comprising:
a) a syringe comprising a plunger and a syringe body having a first open end and a second open end, wherein the plunger fits into the first open end of the syringe body and is slideable to be moved into the syringe body toward the second open end and is slideable to be pulled from the syringe body away from the second open end; and b) a syringe holding and actuation device
i. a first portion that holds the plunger; ii. a second portion that holds the syringe body, wherein the first and second portions are moveable relative to each other such that the plunger can be moved into and pulled from the syringe body; iii. an actuation mechanism coupled to at least one of the first and second portions, wherein actuation of the mechanism causes relative motion between the first and second portions; and iv. a transmission coupled to at least one of the first and second portions and to the actuation mechanism, said transmission comprising:
1. a first transmission mode that causes relative movement of the first and second portions in a manner effective to cause the plunger to be moved into the syringe body when the actuation mechanism is actuated; 2. a second transmission mode that causes relative movement of the first and second portions to cause the plunger to be pulled from the syringe body when the actuation mechanism is actuated; and 3. a clutch system comprising a first configuration that causes the transmission to be in the first transmission mode and a second configuration that causes the transmission to be in the second transmission mode, wherein the clutch system comprises a rotatable shaft having an axis of rotation, wherein rotation of the shaft causes relative movement of the first and second portions in the first and second transmission modes, and wherein the shaft is shiftable along the axis of shaft rotation in a manner such that shifting the shaft along the axis of shaft rotation shifts the transmission between the first and second transmission modes on demand.
[0032] In another aspect, the present invention relates to a syringe holding and actuation device for actuation of a syringe comprising a syringe body and a plunger, said device comprising:
a) a first portion that holds the plunger; b) a second portion that holds the syringe body, wherein the first and second portions are moveable relative to each other such that the plunger can be moved into and pulled from the syringe body; c) an actuation mechanism coupled to at least one of the first and second portions, wherein actuation of the mechanism causes relative motion between the first and second portions; and d) a transmission coupled to at least one of the first and second portions and to the actuation mechanism, said transmission comprising:
i. a first transmission mode that causes relative movement of the first and second portions in a manner effective to cause the plunger to be moved into the syringe body when the actuation mechanism is actuated; ii. a second transmission mode that causes relative movement of the first and second portions to cause the plunger to be pulled from the syringe body when the actuation mechanism is actuated; and iii. a clutch system comprising a first configuration that causes the transmission to be in the first transmission mode and a second configuration that causes the transmission to be in the second transmission mode, wherein the clutch system comprises a rotatable shaft having an axis of rotation, wherein rotation of the shaft causes relative movement of the first and second portions in the first and second transmission modes, and wherein the shaft is shiftable along the axis of shaft rotation in a manner such that shifting the shaft along the axis of shaft rotation shifts the transmission between the first and second transmission modes on demand.
[0040] In another aspect, the present invention relates to a method of actuating a syringe, comprising the steps of:
a) providing a syringe actuation device according to claim 2 ; b) loading a syringe into the device; c) selecting a mode of actuation selected from dispensing and aspiration; d) causing the actuation device to be in the desired mode of actuation; and e) actuating the device to cause corresponding actuation of the syringe.
[0046] In another aspect, the present invention relates to a syringe holding and actuation device for actuation of a syringe comprising a syringe body and a plunger, said device comprising:
a) a first portion comprising (i) a slideable carriage that holds the plunger and (ii) gear teeth provided along at least a portion of the slideable carriage such that rotational motion applied to said gear teeth causes generally linear translation of the carriage back and forth corresponding to the direction of the applied rotational motion; b) a second portion that holds the syringe body, wherein the carriage is slideably attached to the second portion such that the carriage is linearly translatable relative to the second portion such that the plunger held by the carriage can be moved into and pulled from the syringe body held by the second portion as the carriage translates; c) an actuation mechanism coupled to at least one of the first and second portions, wherein actuation of the mechanism causes linear translation of the carriage relative to the second portion; and d) a transmission mounted in the second portion and coupled to the translatable carriage, said transmission comprising:
i. a rotatably driven gear coupled to the gear teeth of the carriage, said rotatably driven gear being driveable in first and second rotational directions to cause corresponding linear translation of the carriage in first and second linear directions relative to the second portion; ii. a first selectively driven gear rotationally coupled to the rotatably driven gear in a manner effective to cause rotation of the rotatably driven gear in the first rotational direction when the first selectively driven gear is selectively driven; iii. a second selectively driven gear rotationally coupled to the rotatably driven gear in a manner effective to cause rotation of the rotatably driven gear in the second rotational direction when the second selectively driven gear is selectively driven; iv. a clutch system comprising a first configuration that causes the transmission to be in a first transmission mode that selectively drives the first selectively driven gear and a second configuration that causes the transmission to be in a second transmission mode that selectively drives the second selectively driven gear, wherein the clutch system comprises a rotatable shaft having an axis of rotation, wherein the rotatable shaft is rotatably driven by actuation of the actuation mechanism, wherein rotation of the shaft rotatably drives one of the first and second selectively driven gears on demand, and wherein the shaft is shiftable along the axis of shaft rotation in a manner such that shifting the shaft along the axis of shaft rotation shifts the transmission between the first and second transmission modes on demand.
[0055] In another aspect, the present invention relates to an actuation device to control motion of a workpiece, comprising:
a) a moveable component coupled to the workpiece; b) a transmission coupled to the moveable component, said transmission comprising:
i. a first transmission mode that causes the moveable component to be actuated in a first manner when the actuation device is actuated; ii. a second transmission mode that causes the moveable component to be actuated in a second manner when the actuation device is actuated; and iii. a clutch system comprising a first configuration that causes the transmission to be in the first transmission mode and a second configuration that causes the transmission to be in the second transmission mode, wherein the clutch system comprises a rotatable shaft having an axis of rotation, wherein rotation of the shaft causes the transmission to actuate the moveable component, and wherein the rotatable shaft is shiftable along the axis of shaft rotation in a manner such that shifting the shaft along the axis of shaft rotation shifts the transmission into the first or second transmission modes on demand.
[0061] In another aspect, the present invention relates to an actuation device to control motion of a workpiece, comprising:
a) a moveable component coupled to the workpiece; b) a transmission coupled to the moveable component, said transmission comprising:
i. a rotatably driven gear coupled to the moveable component, said rotatably driven gear being driveable in first and second rotational directions to cause corresponding first and second motions of the moveable component; ii. a first selectively driven gear rotationally coupled to the rotatably driven gear in a manner effective to cause rotation of the rotatably driven gear in a first rotational direction when the first selectively driven gear is selectively driven; iii. a second selectively driven gear rotationally coupled to the rotatably driven gear in a manner effective to cause rotation of the rotatably driven gear in a second rotational direction; and iv. a clutch system comprising a first configuration that causes the transmission to be in a first transmission mode that selectively drives the first selectively driven gear and a second configuration that causes the transmission to be in a second transmission mode that selectively drives the second selectively driven gear, wherein the clutch system comprises a rotatable shaft having an axis of rotation, wherein the rotatable shaft is rotatably driven and wherein rotation of the shaft rotatably drives one of the first and second selectively driven gears on demand, and wherein the shaft is shiftable along the axis of shaft rotation in a manner such that shifting the shaft along the axis of shaft rotation shifts the transmission between the first and second transmission modes on demand.
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate several aspects of the present invention and together with description of the exemplary embodiment serve to explain the principles of the invention. Additionally, foregoing and other objects, features and advantage of the invention will be apparent from the following description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. A brief description of the drawing is as follows:
[0069] FIG. 1 (prior art) is a perspective view of a typical syringe with the plunger separated from the syringe body.
[0070] FIG. 2 (prior art) is a perspective view of the syringe of FIG. 1 with the plunger assembled in the syringe body.
[0071] FIG. 3 (prior art) is a perspective view of the syringe of FIG. 1 with a user hand gripping the syringe to dispense or inject.
[0072] FIG. 4 (prior art) is a perspective view of the syringe of FIG. 1 with a user hand gripping the syringe to aspirate.
[0073] FIG. 5 is a perspective view of a preferred embodiment of an injection and aspiration device according to the present invention.
[0074] FIG. 6 is a perspective view of the embodiment of FIG. 5 coupled to a syringe.
[0075] FIG. 7 is a perspective closeup view of select components of the transmission assembly within the device of FIG. 5 .
[0076] FIG. 8 is a bottom view of select components of FIG. 7 .
[0077] FIG. 9 is the same view as FIG. 8 except with the components inside one of the gears shown exploded from the main assembly.
[0078] FIG. 10 is a perspective view of select transmission components from FIG. 7 with the ratchet and pawl components shown exploded from the main assembly.
[0079] FIG. 11 is a perspective view of the components from FIG. 10 with a trigger attached.
[0080] FIG. 12 is a perspective view of select components of the clutch mechanism of the device of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
[0081] Exemplary embodiments of the present invention are described in the following with reference to the drawings. It should be understood that such embodiments are by way of example only and merely illustrative of the many possible embodiments which can represent applications of the principles of the present invention. Various changes and modifications obvious to one skilled in the art to which the present invention pertains are deemed to be within the spirit, scope and contemplation of the present invention as further defined in the appended claims. The exemplary embodiments of the present invention described herein are not intended to be exhaustive or to limit the present invention to the precise forms disclosed in the following detailed description. Rather the exemplary embodiments described herein are chosen and described so those skilled in the art can appreciate and understand the principles and practices of the present invention.
[0082] Referring to FIGS. 1 and 2 , a typical syringe 100 is shown disassembled in FIG. 1 and assembled in FIG. 2 . Syringe 100 is a type of syringe that is easily used in many modes of practice of the present invention. One illustrative system of the present invention that incorporates these types of syringes is described further below. The syringe 100 includes a plunger 101 and a syringe body 102 . The end of the plunger often is made of a material and of a diameter that allow end 103 and optionally other portion(s) of plunger 101 to seal against the inner wall of the main part of the syringe body 102 along which the plunger 101 moves. Syringe body 102 defines a reservoir 119 for holding material(s) (not shown) to be dispensed from or aspirated into body 102 . The open tip 104 of the syringe body 102 is opposite the end 109 through which the plunger 101 is inserted. Tip 104 has an opening 112 through which the fluid passes into and out of the syringe body 102 as the plunger 101 is moved accordingly. This opening 112 is typically smaller than the main portion or bore of the syringe body 102 along which the plunger 101 including 103 travels so that tip 104 can be connected to other components like needles, tubing, and catheters, for example. The exterior of the syringe body 102 typically has a flange 105 to facilitate a user or equipment to interface with the syringe body. In FIG. 1 , flange 105 is shown with two extensions or tabs 106 and 107 . The plunger 101 typically also has a plunger flange 108 that is used to facilitate a user or equipment to interface with the plunger 101 .
[0083] The process of injecting or dispensing material that may be within reservoir 119 of the syringe body 102 is accomplished by moving the plunger 101 towards the tip 104 of syringe body 102 as indicated by arrow 110 in FIG. 2 . For purposes of the present invention, this first mode of actuation of plunger 101 is referred to as the forward or dispensing mode of actuation. The process of aspirating material into the syringe body 102 is accomplished by moving the plunger 101 away from the tip 104 of the syringe body 102 as indicated by arrow 111 in FIG. 2 . For purposes of the present invention, this second mode of actuation of plunger 101 is referred to as the reverse or aspirating mode of actuation. Using syringe 100 by itself, injection and aspiration can be done manually by a user with a single hand if the syringe is not too large. Manual actuation, particularly one-handed actuation, is more difficult with larger syringes. In contrast, manual actuation is substantially easier using principles of the present invention, even with larger syringes. Moreover, the systems of the present invention described below also allow a user to easily select either the forward or reverse actuation modes on demand. In preferred modes of practice, the same hand that actuates the system also can be used to select the desired actuation mode.
[0084] FIG. 3 illustrates one manner in which a user would hold a syringe 200 for dispensing with a single hand 201 without assistance from an actuation accessory of the present invention. In this example, two fingers 202 and 203 are placed on the tabs 204 and 205 of the syringe body flange 206 , and the thumb 207 on the plunger flange 208 . When the syringe 200 gets larger in length and cross section size, such as with a 60 mL size syringe, the ability to squeeze a fully filled syringe with a single hand becomes very difficult. One factor contributing to this difficulty is the increasing distance 209 that the fingers 202 and 203 must reach. As this distance 209 approaches the maximum reach of the hand 201 , the squeeze force a user can apply decreases. For users with small hands, the distance 209 may be so large that a user may not even be able to reach between the plunger flange 206 and the syringe body flange 208 with one hand to start dispensing.
[0085] FIG. 4 illustrates one manner in which a user would hold a syringe 300 for aspirating with a single hand 301 without assistance from an actuation accessory of the present invention. In this example, two fingers 302 and 303 are placed on the plunger flange 304 , and the thumb 305 pushes on one of the tabs 306 of the syringe body flange 307 . If the syringe 300 were to be larger in length and cross section size, such as with a 60 mL size syringe, the ability to fully extend the plunger 308 with a single hand becomes very difficult due to the increasing distance 309 that the fingers 302 and 303 must reach. As this distance 309 approaches the maximum reach of the hand 301 , the pushing force a user can apply decreases. But even more significant is that the reach is largely limited by the reach of the thumb finger 305 relative to fingers 302 and 303 . In some cases, a user may not even be able to fully extend the plunger 308 to completely fill the syringe 300 using only one hand.
[0086] FIGS. 3 and 4 illustrate single hand positions holding a relatively large syringe for dispensing and aspiration, respectively. It can be seen that these two hand positions are very different. To switch between the two holds is awkward and cumbersome without setting the syringe down between the holds or without assistance from a second hand. There are other methods in which the syringe can be held with one hand that are not shown. However, in any position, the hand must span both the syringe flange as well as the plunger flange, and, therefore, the stroke is limited by the size of the user's hand.
[0087] Referring now to FIGS. 5 and 6 a preferred embodiment of a system 50 of the present invention that includes device 500 and syringe 550 coupled to device 500 . System 50 can be used to both dispense and aspirate syringe contents (not shown). System 50 also easily switches between these two modes, advantageously with the same hand holding and actuating the device 500 if desired. FIG. 5 shows just the device 500 and FIG. 6 shows the device 500 with a typical syringe 550 mounted to it.
[0088] The device 500 has a main housing or chassis 513 made of two halves 501 and 520 , each with a holder 502 and 523 respectively, which interface with the syringe body flange 552 of the syringe body 551 . The two housing halves 501 and 520 are held together in this example with fasteners 519 and 522 . Any number of fasteners could be used and alternative fastening methods could also be used such as snaps or adhesives for bonding the two halves. Housing half 501 also has guide rail 504 incorporated into it, and housing half 520 has guide rail 503 incorporated into it.
[0089] The carriage 505 is a component with a tooth pattern 509 incorporated into the bottom side along at least a portion of the length of carriage 505 . Each side of carriage 505 has a channel (only one channel 506 can be seen in these views) that is along its entire length in this embodiment for purposes of illustration. The rear of the carriage 505 has a protruding structure 521 into which a retention feature or holder 507 is incorporated. The other end (not seen in the figures because the view is obstructed by the holder 502 ) does not have any protruding features in this embodiment, but may include such features in other embodiments. The plunger 553 of the syringe 550 has plunger flange 554 , which interfaces with and is held by the carriage holder 507 . The side channels (only 506 is seen in these views) of carriage 505 slidingly interface with mating rails 503 and 504 . The carriage 505 also has a tooth pattern 509 to which the tooth pattern of the main drive gear 701 interfaces.
[0090] Referring now also to FIGS. 7 through 12 , the device 500 has transmission assembly 700 which includes clutch system 531 and gear system 541 . Clutch system 531 includes clutch 511 , trigger 510 , pawl holder plate 840 , threaded ball plunger 831 , pawls 801 and 802 , and ratchet gear 800 , which has a D-shape shaft opening 803 . The clutch 511 has grooves 832 and 833 , a shaft 532 , and a clutch plate 705 that has holes 706 . Pawl 801 has a shaft 804 and flex arm 805 . Pawl 802 has a shaft 810 and flex arm 806 . Gear system 541 includes gears 701 , 702 , 703 , and 704 , gear holder plate 841 , and post plate 714 and spring 715 that comprise post assembly 712 for gear 702 .
[0091] Depending upon which operation mode is selected, transmission assembly 700 can drive carriage 505 forward (first or dispense mode) or in reverse (second or aspiration mode). Forward mode presses plunger 553 into syringe body 551 . This creates pressure that dispenses syringe contents. Reverse mode pulls plunger 553 out of syringe body 551 . This creates aspiration that pulls contents into syringe 550 from an external source. Transmission assembly 700 includes clutch features to easily shift between forward and reverse modes on demand.
[0092] The transmission assembly 700 transmits the actuation force imparted by the user on the trigger 510 to the carriage 505 . The transmission assembly 700 can change the rotational direction of the main drive gear 701 when the clutch 511 is shifted from one side to the other along its axis as indicated by the arrow 512 . This unique transmission assembly 700 allows a user to move the plunger 553 of the syringe 550 in either direction (aspiration or dispensing) using the same trigger actuation of the trigger 510 towards the grip 513 of the chassis 501 . The clutch 511 is designed and positioned in a way that a user can easily move it from side to side. Advantageously, this can be accomplished using a finger and/or thumb of the same hand that is holding and pulling the trigger 510 if desired. A torsion compression type spring 860 is incorporated between the inside of the trigger 510 and the housing 513 to keep the trigger 510 biased open (starting position) and away from the housing 513 .
[0093] Referring to FIG. 7 , the transmission assembly 700 is shown in greater detail with just a portion of the housing half 520 shown. The teeth of the main gear 701 engage with the teeth 509 of the carriage 505 . There are two gears 702 and 703 that directly engage with the main gear 701 . Gear 703 also engages directly with gear 704 . Clutch 511 causes one of gears 702 and 704 to be selectively engaged and driven by trigger actuation at one time. The clutch 511 has a clutch plate 705 with a number of holes 706 that are used to selectively engage the clutch 511 with one of gears 702 and 704 . The shaft of the clutch 511 passes through the bore of gears 702 and 704 , and through ratchet 800 (also called ratchet gear 800 ). As will be shown later, the bore of ratchet 800 has a key feature to rotationally lock it to the shaft of the clutch 511 . The ratchet 800 engages with pawl 801 that is mounted to trigger 510 and pawl 802 that is mounted to housing 501 .
[0094] Now referring also to FIG. 8 , a bottom view of select components of the transmission assembly 700 is shown further illustrating the gears 702 and 703 that directly engage with the main gear 701 . The gears 702 and 704 that also directly engage with the clutch 511 are shown. In this view, a plurality of posts 710 that extend from gear 702 and a plurality of posts 711 that extend from gear 704 are visible. These posts 710 and 711 selectively pass into the holes of the clutch plate 705 to rotationally lock the clutch plate 705 to the corresponding gear being engaged at the time. In FIGS. 7 and 8 the clutch 511 is shown engaged with gear 704 , and posts 711 help secure clutch plate 705 to gear 704 .
[0095] FIG. 9 shows the same components as in FIG. 8 but with an exploded view of the post assembly portion 712 for gear 702 . The posts 710 extend from a common plate 714 through which the shaft of the clutch 511 also passes. A spring 715 , shown as a wavy spring, presses against the post plate 714 on one side and is held against housing 501 (not shown in this FIG.) to create a force to bias plate 714 toward clutch plate 705 . The spring 715 also has the shaft of the clutch 511 pass through it. The spring 715 allows the posts 710 to be depressed by the clutch plate 705 if holes 706 do not happen to align with the posts 710 at the time the clutch 511 initially is shifted to engage with gear 702 . A similar type of assembly as post assembly portion 712 exists for the other gear 704 , so that clutch 511 can engage gear 704 to rotate gear 701 , and hence drive carriage 505 , in the other direction.
[0096] From these descriptions of the gear and clutch components of transmission assembly 700 illustrated in FIGS. 7 through 9 , it can now be seen how, as the clutch 511 selectively engages gears of transmission assembly 700 , trigger actuation can move the carriage 505 forward or backwards, which correspond to dispensing and aspirating the syringe, respectively. The forward or reverse mode is selected depending upon whether clutch 511 is engaged with gear 702 or 704 .
[0097] Now referring to FIGS. 10 and 11 , ratchet features are shown in more detail that describe how the ratchet 800 can be controlled using pawls 801 and 802 to only rotate ratchet 800 in one (forward) direction 809 . For purposes of illustration, the ratchet 800 and pawls 801 and 802 are removed from the shaft of the clutch 511 in FIG. 10 to show how the D-shape bore 803 of the ratchet 800 interlocks with the mating D-shape portion 807 of the clutch 511 . As a result of this interlock, any rotation of the ratchet 800 will cause a rotation of the shaft 532 of the clutch 511 . The shaft 804 of pawl 801 engages with the trigger 510 and allows pawl 801 to pivot about the shaft 804 . Flexure 805 of pawl 801 is flexed against the inside of the trigger 510 . This creates a bias force that keeps the pawl 801 pressed against the ratchet 800 and yet allows pawl 801 to ride over the teeth of the rotating ratchet 800 . The orientation of pawl 801 to the ratchet 800 is such that, as the trigger 510 is squeezed or pulled towards the grip 513 ( FIGS. 5 and 6 ), the teeth of the pawl 801 interlock with the teeth of the ratchet 800 and cause the ratchet 800 to rotate in direction 809 . This in turn causes the clutch 511 to rotate also in forward direction 809 . When the trigger 510 is released, spring 860 shown in FIGS. 5 & 6 moves the trigger 510 back outward and it is during this motion that the pawl 801 rides over ratchet 800 teeth. In short, trigger 510 is operatively coupled to ratchet 800 via pawl 801 so that trigger actuation rotationally drives ratchet 800 forward in direction 809 and hence the shaft 532 of the clutch 511 . This motion will cause the carriage 505 to move either forward or backward depending on which gear, 702 or 704 , the clutch plate 705 selectively engages. The second pawl 802 prevents backward rotation (opposite 809 ) of ratchet 800 .
[0098] Pawl 802 also has a shaft 810 that interfaces to the housing 513 shown in FIGS. 5 and 6 , and allows pawl 802 to pivot about this shaft 810 . Flexure 806 of pawl 802 is flexed against the inside of the housing 501 and creates a bias force that biases the pawl 802 against the ratchet 800 to help prevent backwards rotation (opposite 809 ) of ratchet 800 , but yet allows pawl 802 to ride over the teeth of the rotating ratchet 800 to allow forward rotation in direction 809 of ratchet 800 . The orientation of pawl 802 to the ratchet 800 is such that as the trigger 510 is squeezed or pulled towards the grip 513 ( FIGS. 5 and 6 ), the teeth of the pawl 802 pass over the rotating ratchet 800 . When the trigger 510 is released, spring 860 shown in FIGS. 5 and 6 push the trigger 510 back open, while the teeth of pawl 802 engage the ratchet 800 and prevent counter rotation (opposite 809 ) of the ratchet 800 and therefore motion of the transmission 700 and carriage 505 . The two pawls 801 and 802 therefore only allow the ratchet 800 to rotate in one direction indicated by arrow 809 in FIG. 10 and help to prevent counter rotation. This is the main principle of these components and the design described herein is the preferred embodiment. Alternative embodiments are possible, and one example would be to make the pawls 801 and 802 completely rigid components and use a compression coil spring to provide the bias forces against the pawls.
[0099] Referring now to FIG. 12 , select components of the device 500 shown in FIG. 1 are shown that show how the clutch 511 is held in the different positions. As has been described previously and shown in the figures in this preferred embodiment, the clutch 511 can move side to side so that its clutch plate 705 can selectively engage with gears 702 and 704 . To ensure that the clutch 511 maintains the engaged position and provides a tactile feedback to the user that the engagement has been achieved, the housing 520 has a threaded hole 830 into which a standard type of threaded ball plunger 831 is placed. The ball plunger 831 interfaces with the shaft of the clutch 511 and extends into groove 832 when the clutch 511 is moved to engage with gear 704 , and extends into groove 833 when the clutch 511 is moved in the other direction to engage with gear 702 . The holding force provided by the ball plunger 831 prevents the clutch 511 from being pushed back as it is shifted against one of the gears 702 or 704 when the holes 706 of clutch plate 705 do not happen to align with the respective posts 710 or 711 . When this happens, clutch plate 705 depresses the posts 710 or 711 , which compresses the respective spring, for example spring 715 for posts 710 , until the posts 710 or 711 align with the holes 706 of the clutch plate 705 . This allows the posts 710 or 711 to extend into the holes 706 to create selective engagement between the clutch 511 and the respective gear 702 or 704 .
[0100] The preferred embodiment presented in FIGS. 5 through 12 provides the features to allow a syringe to be dispensed and aspirated by moving a rotating clutch between two positions. The rotation of the shaft 532 of clutch 511 is always in one forward rotationally direction 809 in this illustrative embodiment. Shaft rotation occurs when a user pulls on trigger 510 . The forward rotational direction 809 of clutch 511 is controlled by two pawls, 801 and 802 , and ratchet gear 800 . In the dispensing mode, the clutch 511 is moved to engage gear 704 that meshes with a second gear 703 . Gear 703 in turn meshes with a final drive gear 701 that finally meshes with the teeth 509 of carriage 505 . These series of gears are necessary so that the single forward rotational direction 809 of clutch 511 moves the carriage 511 forward to dispense contents of a syringe. In the aspiration mode, the clutch 511 is moved to engage gear 702 , which meshes directly with the final drive gear 701 that again meshes with the teeth 509 of carriage 505 . In this way, the single forward rotational direction 809 of clutch 511 can also move the carriage 511 backwards to aspirate material into the syringe. The single forward rotational direction 809 of clutch 511 is created by having a pawl 801 attached to trigger 510 . This pawl 801 drives the rotation of ratchet gear 800 which is directly coupled to clutch 511 . When the user releases trigger 510 , the spring 860 pushes the trigger 510 back open to the starting trigger position for the user to squeeze the trigger 510 again. The second pawl 802 prevents the ratchet gear 800 and therefore the directly coupled clutch 511 from rotating in the backwards rotational direction (opposite direction 809 ) as the trigger 510 is pushed back to the starting trigger position.
[0101] An alternative embodiment of a different configuration is one in which an additional groove is provided, e.g., placed between the two 832 and 833 that are used to engage the gears 702 and 704 . This additional groove would allow a neutral position where the clutch plate 705 does not engage either set of gears 702 or 704 . In another preferred embodiment, an aspiration-only configuration is created by removing gears 704 and 703 . In yet another preferred embodiment of a dispensing-only configuration, gear 702 is removed. In yet another preferred embodiment, the holder 502 and 523 can be detached from the housing halves 501 and 520 , and connected to its own carriage that is connected by additional gears to the main gear 701 so that it moves in a direction opposite the carriage 505 .
[0102] Advantageously, all of the components described herein can be made of non-ferrous materials which would make them suitable for use with MRI. The gears and housing in particular can also be cost effectively mass produced with injection molded plastic. Additionally, the relative sizes of the gears can be modified to generate different amounts of mechanical advantage for the force transmitted to the syringe by the trigger independently for each direction.
[0103] There are other applications where it is desired to have an ability to control motion of one or more components and the direction of such motion. Some additional applications involve controlling the motion of a fluid (e.g., to dispense, inject, or aspirate a fluid). Other applications involve controlling the position of one or more solid items. The present invention would be suitable to control actuation in multiple directions in a wide variety of such applications, including but not limited to the following exemplary uses.
[0104] General barrel plunger devices are conceptually similar to a fluid syringe but instead are configured so that a plunger is coupled to a solid object instead of a fluid. The principles of the present invention can be used to control actuation of the barrel plunger in both forward and reverse directions.
[0105] Some gripping devices control the movement of gases in order to grip and release items. For example, one device (known as a pooter device) allows small insects to be gently collected and held against an intake membrane such as a filter by steady intake of air through the membrane. The insect can be transferred to a container or other target by reversing operation and dispensing air or other gas through the membrane in the other direction. Vacuum gripping devices also are used in the microelectronic industry to hold workpieces. The principles of the present invention can be used to control actuation of pressurizing and aspirating components that cause the gas to provide gripping and releasing forces on demand.
[0106] Manual positioning systems can be used to control the position of items. An example is to control the height position of a chair via positive manual actuation to raise, lower, twist, or otherwise modify the chair configuration. Conventionally, gravity often is used to create a downward motion and a mechanical force would be used for upward motion. This conventional system would be replaced by a mechanism of the present invention that allows a user to control and move the chair in both directions via mechanical actuation, preferably without needing to stand up to raise or lower the height of the chair.
[0107] In another type of manual positioning system, one or more clamps are used to maintain the position of an object. Releasing the clamp allows the object to be re-positioned. A specific example includes the clamps that are used to position the legs of a camera tripod. The principles of the present invention can be used to control actuation of the clamps to both grip and release objects.
[0108] The present invention can also be used in toy water guns to control pressure and dispensing mechanisms. For instance, a transmission of the present invention can be used to actuate one or more components in a manner effective to aspirate water into the barrel of a toy water gun. The transmission mode can then be switched to actuate one or more components in a manner effective to dispense the water as a jet. Alternatively, the transmission of the present invention can be used to actuate one or more components in a manner effective to pressurize at least one chamber that to dispense the water. In some embodiments this could replace a typical two-handed pump action and allow pressurizing and dispensing to be accomplished with one hand.
[0109] The principles of the present invention also can be incorporated into other kinds of gripping tools such as clamps used to hold items together for gluing, welding, bolting, nailing, screwing, other fastening, or other treatment. Examples of these include clamps used in wood and metalworking. Other examples include golf shaft extractors that both grip a golf shaft and push against a club head to remove the head from the shaft. Transmissions of the present invention can be used to create the force that grips and releases the club and/or the force that pushes against the club head relative to the shaft.
[0110] The present invention has now been described with reference to figures of an exemplary embodiment thereof. The entire disclosure of any patent or patent application identified herein is hereby incorporated by reference for all purposes. The foregoing disclosure has been provided for clarity of understanding by those skilled in the art of injection and aspiration devices. No unnecessary limitations should be taken from the foregoing disclosure. It will be apparent to those skilled in the art that changes can be made in the exemplary embodiment described herein without departing from the scope of the present invention. Thus, the scope of the present invention should not be limited to the exemplary structures and methods described herein, but only by the structures and methods described by the language of the claims and the equivalents of those claimed structures and methods. | The present invention provides actuation mechanisms that incorporate a transmission assembly that allows the mechanisms to cause actuation of workpieces according to a plurality of transmission modes (e.g., at least one forward transmission mode and at least one reverse transmission mode) on demand. Motion, direction, and/or force can be controlled by selecting the corresponding transmission mode. The mechanisms preferably are trigger-actuated by hand (i.e., manually) to cause movement of a workpiece in a desired direction. Desired directions can be linear or nonlinear. The same hand used for trigger action can also be used to change transmission modes in many modes of practice, even while using substantially the same grip used for trigger actuation. In other instances, actuation can be automated rather than manual. Preferably, both actuation and witching among transmission modes can be accomplished with one hand, even while maintaining substantially the same grip that is used for actuation. | 0 |
BACKGROUND
The present description relates to a method of controlling an internal combustion engine, and more particularly relates to a method of feedback controlling an air fuel ratio of air fuel mixture supplied to an internal combustion engine using a heated exhaust gas oxygen sensor.
There is known and presented, for example in U.S. Pat. No. 6,848,439, an exhaust gas oxygen sensor arranged in an exhaust passage between an internal combustion engine and a catalytic converter. The sensor is capable of outputting a signal that corresponds linearly to the oxygen concentration in the exhaust gases. The '439 patent also shows a method of using the sensor output for feedback controlling an air-fuel mixture to an internal combustion engine. The exhaust gas oxygen sensor outputs a linear signal when its temperature is within a higher operative temperature range, between 700-800° C. for example. On the other hand, the sensor outputs a non-linear signal around the stoichiometric air-fuel ratio at a lower operative temperature range, between 300-400° C. for example. The exhaust gas oxygen sensor is provided with a heater, which may be used to heat the sensor temperature to the operative range.
When the exhaust gas oxygen sensor is cooled down after an engine stop and an internal combustion engine is started again, a water content of the exhaust gas or combusted gas may be partly condensed by contacting the sensor surface. If the heater is then used to heat the exhaust gas oxygen sensor, the condensed water may cause the sensor output to degrade. The '439 patent describes a method to avoid such degradation by choosing the lower temperature range as its target temperature. The '439 patent also describes using the sensor at lower operating temperatures to provide feedback control of engine air fuel mixtures around the stoichiometric air fuel ratio within a predetermined time period after an engine start.
However, it is possible under certain circumstances to increase the amount of water in the exhaust gas that condenses on the sensor surface. For example, when hydrogen is used as a fuel instead of fossil fuels, such as gasoline, combustion of hydrogen may create more water in the exhaust gas because hydrogen readily combines with air to produce water. As the amount of the condensed water increases, it may make it difficult to heat the sensor after an engine start, even to the lower target temperature. Further, since combusted hydrogen exhibits lower exhaust gas temperatures, the time period that condensation occurs in the exhaust system can be increased when compared to combusted fossil fuels. The condensation may make it difficult to precisely feedback control the engine air-fuel ratio based on feedback from the sensor output. Consequently, engine emissions and fuel economy may be degraded when exhaust gases condensate into water in the exhaust system.
Therefore, there is a need to improve the prior art method of feedback controlling an air-fuel ratio using a heated exhaust gas oxygen sensor.
SUMMARY
Accordingly, there is provided, in one aspect of the present description, a method of controlling an internal combustion engine system. The method comprises supplying a first amount of electric energy to heat to an upstream sensor located in an exhaust gas passage from the internal combustion engine and upstream of an exhaust gas after-treatment device and adjusting an air fuel mixture supplied to the internal combustion engine based on an output of the upstream sensor during a first engine operating condition. The method further comprises supplying a second amount of electric energy, which is smaller than the first amount, to heat the upstream sensor and adjusting the air-fuel mixture based on an output of a downstream sensor located in the exhaust gas passage and downstream of the exhaust gas after-treatment device during a second engine operating condition.
By adjusting the air fuel-ratio based on an output of the downstream sensor during the second engine operating condition, the air fuel-ratio can be adjusted under less influence from the condensed water. Since the downstream sensor is located downstream of the exhaust gas after-treatment device, much of the water vapor in the exhaust gas may be condensed before the exhaust gases reach the downstream sensor. This allows the downstream sensor to operate with less influence from the condensing water vapor. Therefore, during the second engine operating condition, the engine air fuel ratio can be more precisely adjusted so that engine exhaust emissions and fuel economy may be improved.
In another aspect, the method comprises adjusting an air-fuel mixture supplied to the internal combustion engine by more heavily weighting an output of the downstream sensor than an output of the upstream sensor during a first predetermined period, and adjusting the air-fuel mixture by more heavily weighting the output of the upstream sensor than the output of the downstream sensor after the first predetermined period. By adjusting the air-fuel mixture by more heavily weighting the output of the downstream sensor prior to more heavily weighting the output of the upstream sensor, the air-fuel mixture can be adjusted under less influence of the water in the exhaust gas because the water is less likely to condense as the period goes by and the engine system temperature increases. Therefore, the engine air fuel ratio can be more precisely adjusted over time.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages described herein will be more fully understood by reading an example of embodiments in which the above aspects are used to advantage, referred to herein as the Detailed Description, with reference to the drawings wherein:
FIG. 1 shows a schematic view of an engine system in accordance with an embodiment of the present description;
FIG. 2 is a circuit diagram showing an upstream sensor which detects an oxygen concentration in the exhaust gas and has an electric heater in accordance with the embodiment;
FIG. 3 is a circuit diagram the electric heater of the upstream sensor in accordance with the embodiment;
FIG. 4 is a map which defines engine operating regions on an engine speed and desired engine torque;
FIG. 5 is a flowchart showing a routine to control the engine system in accordance with the embodiment of the present description;
FIG. 6 shows time charts of temperatures of exhaust gas oxygen sensors, heater control, and fuel control; and
FIG. 7 shows a graph of NOx emission versus air fuel ratios.
DETAILED DESCRIPTION
An embodiment of the present description will now be described with reference to the drawings, starting with FIG. 1 , which shows a schematic view of an engine system including an internal combustion engine 1 fueled with gaseous hydrogen. The engine system is mounted on a vehicle, such as an automotive vehicle, and its output is transmitted to vehicle driving wheels through a power transmission mechanism as is well known in the art.
The engine system comprises an intake air passage 2 for inducting fresh air to the engine 1 , an exhaust gas passage 3 for expelling an exhaust gas from the engine 1 , and an exhaust gas recirculation (EGR) passage 4 for circulating a part of the exhaust gas back to the intake air passage 2 .
The engine 1 is a rotary piston engine having two substantially triangular shaped rotors 11 and 21 . The rotary piston engine 1 has two rotor housings 10 and 20 , which are arranged at both sides of an intermediate housing not shown and between front and rear housings also not shown. The rotors 11 and 21 are housed respectively within the rotor housings 10 and 20 . The inner periphery of the rotor housing 10 , the outer periphery of the rotor 11 , and the intermediate and front housings collectively define three combustion chambers, while the inner periphery of the rotor housing 20 and the others define three combustion chambers as well. The rotors 11 and 21 are arranged rotatably around eccentric shafts 12 and 22 , which have a common rotational axis also common with an output shaft of the engine 1 . When the output shaft makes one rotation, each rotor makes three rotations and causes the operational chambers to change the volumes and make an engine cycle (Otto cycle).
An intake port 2 a is arranged in one of the rotor, intermediate and front or rear housings so as to communicate to a combustion chamber in an intake stroke. Also, an exhaust port 3 a is arranged in one of the housings so as to communicate to a combustion chamber in an exhaust stroke.
Pairs of spark plugs 13 and 23 are arranged in ones of the housings so as to face a combustion chamber in compression and expansion strokes. The spark plug is coupled to an ignition circuit not shown. The ignition circuit is controlled by an engine controller 100 so that the spark plug can spark at desired timing determined by the engine controller 100 .
Direct fuel injectors 14 and 24 are also arranged in one of the housings respectively so as to face an operational chamber in intake and compression strokes. The direct fuel injectors 14 and 24 are supplied with gaseous hydrogen fuel from a hydrogen storage tank, such as a metal hydrate tank, through a fuel supply system not shown. The direct fuel injector has a solenoid valve inside. The solenoid valve is actuated by a driver circuit not shown which is controlled by the engine controller 100 . Therefore, the direct fuel injector can directly inject gaseous hydrogen directly into a combustion chamber in a compression stroke or an intake stroke at desired timing determined by the engine controller 100 . As is known in the art, when the fuel is injected in a compression stroke, the air-fuel mixture can be combusted even if an overall air fuel ratio of the charged mixture is substantially leaner than the stoichiometry. At that time, the air-fuel mixture is stratified. On the other hand, when the fuel is injected in an intake stroke, the air-fuel mixture will be homogeneous.
Also, port fuel injectors 15 and 25 are arranged in the intake ports 2 a . The port fuel injector is also supplied with gaseous hydrogen fuel from the hydrogen storage tank through the fuel supply system, and has a solenoid valve that is actuated by a driver circuit which is controlled by the engine controller 100 . The port fuel injector can inject gaseous hydrogen into the intake port 2 a at desired timing determined by the engine controller 100 . Therefore, the port fuel injector can inject gaseous hydrogen fuel into the intake port 2 a at desired timing determined by the engine controller 100 . When the injected fuel and air are inducted from the intake port 2 a into a combustion chamber, the air and fuel mixture is substantially homogeneous.
In the intake passage 2 , an airflow meter 30 and a throttle valve 31 are arranged in that order from the upstream side. The airflow meter 30 detects airflow through the intake passage 2 and outputs a corresponding signal to the engine controller 100 . A throttle valve actuator 42 actuates the throttle valve 31 and adjusts its opening in accordance with a signal from the engine controller 100 .
In the EGR passage 4 , an EGR valve 35 is arranged, and actuated by an EGR actuator 43 which adjusts an opening of the EGR valve 35 in accordance with a signal from the engine controller 100 .
In the exhaust passage 3 , a three-way catalyst converter 32 is arranged. The three-way catalyst converter 32 has a conventional structure comprising a casing and a catalyst brick sustained in the casing. The catalyst brick comprises a honeycomb shaped carrier, and a catalyst layer coated on the carrier. The honeycomb shaped carrier may be made of porous material such as cordierite. Upstream of the catalyst converter 32 in the exhaust passage 3 , an upstream oxygen sensor 33 is arranged, which detects a concentration of oxygen in the exhaust gas and outputs electric current in proportion to the detected oxygen concentration as described in greater detail below. It may be called a linear sensor because of linearity of its output.
Downstream of the catalyst converter 32 in the exhaust passage 3 , a downstream oxygen sensor 34 is arranged, which also detects a concentration of oxygen in the exhaust gas, but outputs electric current that abruptly changes around the stoichiometric air fuel ratio. Therefore, it may be called a lambda sensor since the stoichiometric air fuel ratio corresponding to an excessive air ratio λ (lambda)=1. The downstream sensor may be arranged on the casing of the catalyst converter for a simpler assembly process of an entire exhaust system. It is preferably arranged downstream of the catalyst brick, while it can be arranged between the bricks if there are a plurality of bricks.
FIG. 2 shows a detailed structure of the upstream sensor 33 . It comprises a sensor element portion 33 a , a heater 33 b that is basically comprised of an electric resistor and arranged in the proximity of the sensor element part 33 a and can heat it by transmitting electrically generated heat, a sensor circuit 33 c , and a heater circuit 33 d that can keep the sensor element portion 33 a at a predetermined temperature.
The sensor element portion 33 a has an oxygen cell element 33 e and an oxygen pump element 33 f made of oxygen ion conductive solid electrolyte material such as zirconia. The oxygen cell element 33 e generates electricity at its both sides in dependence on a ratio of oxygen concentrations between at its both sides, while the oxygen pump element 33 f pumps oxygen from its one side to the other in dependence on electricity applied to its both sides. Electrode layers 33 e ′ are formed on the both sides of the oxygen cell element 33 e , and electrode layers 33 f ′ are formed on the both sides of the oxygen pump element 33 f.
A dispersion chamber 33 h is defined by the pair of oxygen pump elements 33 e and 33 f , a part of a casing of the sensor element 33 a , and a dispersion layer 33 g . The dispersion chamber 33 h communicates with the exhaust passage 3 through the dispersion layer 33 g so that the exhaust gas flows between the exhaust passage 3 and the dispersion layer 33 g at constant dispersion rate. A relative oxygen concentration chamber 33 i is formed at one side of the oxygen cell element 33 e , and an oxygen concentration therein is maintained constant, for example, by communicating to the atmosphere.
The sensor circuit 33 c is connected to the sensor element portion 33 a , and comprises an operational amplifier 33 j , a resister 33 k , and output terminals 33 m.
When the oxygen ion conductive solid electrolyte material used for the oxygen cell element 33 e and the oxygen pump element 33 f is arranged between two chambers of different oxygen partial pressures (or concentrations), oxygen ions pass through the element depending on a ratio of the oxygen partial pressures of the both chambers until the equilibrium, and generate electromotive force, thereby functioning as an electric cell. On the other hand, when there is a voltage difference between the both sides of the material, it pumps oxygen from one side to the other.
Then, the operational amplifier 33 j adjusts current flowing to the oxygen pump element 33 f in accordance with change of voltage generated at the oxygen cell element 33 e . When oxygen in exhaust gas in the dispersion chamber 33 h increases, the oxygen pump element 33 f pumps out the oxygen from the dispersion chamber 33 h to the outside. When oxygen in exhaust gas in the dispersion chamber 33 h decreases, the oxygen pump element 33 f pumps oxygen into the dispersion chamber 33 h from the outside. The pumping function of the oxygen pump element 33 e is going to maintain a state corresponding to the stoichiometric air fuel ratio in the dispersion chamber 33 h . But, the exhaust gas flows into the dispersion chamber 33 h through the dispersion layer 33 g at the constant rate, and the pumping function does not stop unless an oxygen concentration in the dispersion chamber 33 h matches to the stoichiometric air fuel ratio. Therefore, an amount of the oxygen pumped out by the oxygen pump element 33 f is in proportion to a difference between an oxygen concentration in the exhaust passage 3 and an oxygen concentration in the dispersion chamber 33 h which is supposedly corresponding to the stoichiometric air fuel ratio due to the function of the oxygen cell element 33 e . Then, the current adjusted by the operational amplifier 33 j for actuating the oxygen pump element 33 f flows through the resister 33 k . At the terminals 33 m , a voltage in proportion to the current and the oxygen concentration in the exhaust passage 3 can be output.
FIG. 3 shows the heater 33 b and the heater circuit 33 d . The heater 33 b is basically comprised of a resistor, and the heater circuit 33 d is basically constituted with a bridge circuit including resistors 33 n , 33 p and 33 q , a transistor 33 r , and an operational amplifier 33 s . The resistor of the heater 33 b changes its electric resistance depending on its temperature, as is well known in the art. On the other hand, the resistors 33 n , 33 p and 33 q do not substantially change their resistances. Therefore, a voltage at a point between the heater 33 b and the resistor 33 p changes depending on the temperature of the heater 33 b . On the other hand, a voltage at a point between the resistors 33 n and 33 q does not substantially change, therefore it can be used as a reference voltage at the operational amplifier 33 s . Output of the operational amplifier 33 s is input to the transistor 33 r , and it regulates electric current to the heater 33 b in accordance with the temperature of the heater 33 b . Therefore, it is feedback controlled to be a temperature corresponding to the reference voltage at the operational amplifier 33 s . Although it is not shown, electric supply to the heater circuit 33 d can be shut down by a switching relay or a power transistor known in the art, which is controlled by the engine controller 100 .
The downstream lambda sensor 34 basically consists of an oxygen cell element, and does not have an oxygen pump element. Therefore, an output signal of the downstream lambda sensor 34 rapidly changes between below and above a predetermined oxygen concentration. That is, the lambda sensor 34 outputs voltage of about 1 volt at an oxygen concentration of exhaust gas generated when mixture richer than the stoichiometric air fuel ratio is combusted and flows, and outputs voltage of about 0 volt when mixture leaner than the stoichiometric air fuel ratio is combusted and flows. Consequently, it is possible to determine an air fuel ratio of mixture supplied to a combustion chamber is richer or leaner than the stoichiometric air fuel ratio.
By arranging the linear oxygen sensor 33 and the lambda oxygen sensor 34 upstream and downstream of the three way catalyst converter 32 , degradation of the catalyst 32 can be detected. In particular, when the catalyst 32 functions normally, oxygen in exhaust gas is adsorbed by the catalyst 32 so that an oxygen concentration detected by the downstream lambda sensor 34 is relatively smaller than an oxygen concentration detected by the upstream linear sensor 33 . However, when the catalyst 32 is degraded, oxygen storage capacity is decreased so that detected values by the both sensors 33 and 34 are made similar, and based on this, the degradation of the catalyst 32 can be detected. Also, by providing the two sensors 32 and 33 , a variation caused by an individual difference or aging can be adjusted as well.
The engine controller 100 is a microprocessor based controller well known in the art, and as shown in FIG. 1 , receives signals from the airflow meter 30 , the upstream linear sensor 33 , the downstream lambda sensor 34 , an engine speed sensor 40 for detecting an engine rotational speed, an accelerator sensor detecting a position of an accelerator pedal which a driver operates, and other sensors. Based on those input signals, the engine controller 100 computes and outputs signals directly or indirectly, for example through a driver circuit, to the fuel injectors 14 , 15 , 24 , and 25 , the spark plugs 13 and 23 , the throttle actuator 42 , the EGR actuator 43 , the switching relay of the heater 33 b of the upstream linear sensor 33 , and other actuators. Although the heater circuit 33 d adjusts electricity supplied to the heater 33 b of the upstream linear sensor 33 , the engine controller may digitally perform the same function as the analogue heater circuit 33 d does.
The engine controller 100 stores in its memory an operational map 110 , as shown in FIG. 4 , which defines three operational modes in accordance with an engine speed which is detected by the engine speed sensor 40 and a desired engine torque which predominantly corresponds to the signal output from the accelerator sensor 41 . The operational map defines a λ=1 mode in a lower speed and higher torque region 112 , a lean mode (1<λ≈2) in a lower speed and lower torque region 114 , and a high power lean region (λ=1.4-1.6) in a higher speed region 116 .
The engine controller 100 computes a target opening of the throttle valve 31 based on the desired torque, the engine speed and the target air fuel ratio, and controls the throttle actuator 42 to meet the target throttle opening. A base fuel injection amount is computed based on the desired torque, the engine speed and the target air fuel ratio, as well.
When a predetermined time period, for example two minutes, has passed, the engine controller 100 adjusts an air fuel ratio of air and fuel mixture supplied to the engine 1 with reference to the operational map 100 . At this time, the engine controller 100 closed the switching relay or power transistor between the power supply and the heater circuit 33 d of the upstream linear sensor. Therefore, the heater 33 b can receive electricity and maintain the upstream sensor 33 at the predetermined temperature, therefore the sensor 33 is fully operative. The fuel injection amount is feedback controlled using based on the base fuel injection amount and the output of the upstream linear oxygen sensor 33 to meet the target air fuel ratio. At this time, the output of the downstream lambda sensor 34 may be used for a correction of the output of the upstream linear sensor 33 .
In the lower speed and higher torque region 112 , a target air fuel ratio is set the stoichiometric air fuel ratio (corresponding to λ=1). The EGR valve 35 is opened so that the exhaust gas is re-circulated through the EGR passage 4 to the intake passage 2 . The exhaust gas re-circulated into the combustion chamber decreases a combustion temperature, and reduces NOx generation during the combustion. The direct fuel injectors 14 and 24 inject fuel directly to the combustion chambers.
In the lower speed and lower torque region 114 , the target air fuel ratio is set an air fuel ratio leaner than the stoichiometric air fuel ratio, for example corresponding to λ=2. The EGR valve 35 is closed, and direct fuel injectors 14 and 24 inject fuel directly to the combustion chambers.
In the higher speed region, the target air fuel ratio is set an air fuel ratio leaner than the stoichiometric air fuel ratio, for example corresponding to λ=1.4-1.6, which is, in the case of using gaseous hydrogen as fuel, the leanest air fuel ratio as far as pre-ignition that is self ignition before spark ignition by the spark plugs 13 or 23 does not occur. The EGR valve 35 is closed. The direct fuel injectors 14 and 24 inject fuel directly to the combustion chambers, and at the same time, the port fuel injectors 15 and 25 inject fuel to the intake ports 2 a , for higher engine output.
Control of the engine system, particularly the fuel injectors 14 , 15 , 24 , and 25 , and the EGR valve 35 will now be described with reference to a flowchart of FIG. 5 showing a control routine executed by the engine controller 100 . At a step S 1 , the engine controller 100 reads various signals from the airflow meter 30 , the upstream linear sensor 33 , the downstream lambda sensor 34 , the engine speed sensor 40 , and the others. The routine proceeds to a step S 2 , and determines whether or not 20 seconds has passed since an engine start by reading a counter which is integrated into the engine controller 100 as is well known in the art, and has started when the engine 1 is determined to start a self rotation and counts up as time goes by. Alternatively, the counter may count number of rotations of the engine 1 or number of combustion cycles of the engine 1 , from the fuel injection pulse signal sent to the fuel injectors from the engine controller 100 .
If it is determined that 20 seconds has not passed since the engine start at the step S 2 (NO), the routine proceeds to a step S 3 , and stops to supply electricity to the heater 33 b of the upstream linear sensor 33 , for example by the engine controller 100 controlling to open the switching relay. Then, it proceeds to a step S 4 , and sets the target air fuel ratio to correspond to λ=1. After the step S 4 , the routine proceeds to a step S 5 , and computes the base fuel injection amount based on the engine speed, the desired torque and the target air fuel ratio without taking account of the outputs of either of the upstream linear sensor 33 or the downstream lambda sensor 34 (open control). Then, it proceeds to a step S 6 , and the engine controller 100 actuates the direct fuel injectors 14 and 24 to inject the base fuel amount determined at the step S 5 at a desired timing without actuating the port fuel injectors 15 and 25 (direct injection). At the same time, the engine controller 100 controls the throttle actuator 42 to regulate intake airflow to the engine 1 , thereby causing the direct fuel injectors 14 and 24 and the throttle valve 31 to function collectively as an air-fuel regulator to adjust the air-fuel mixture supplied to the engine 1 . Finally, the routine proceeds to a step S 7 , and the engine controller 100 controls the EGR actuator 43 to close the EGR valve 35 . Then, the routine returns.
During the steps S 3 through S 7 , as shown in a time chart of FIG. 6 , the upstream linear sensor 33 and the downstream lambda sensor 34 are likely not to reach active temperatures. Then, it may be difficult to make precise feedback control based on the outputs of these sensors 33 and 34 . Therefore, the feedback control is not made, but the open control is made with the target air fuel ratio to be the stoichiometry. At this time, catalytic reaction of the exhaust gas over the three-way catalyst converter 32 occurs and generates heat to increase the gas temperature downstream of the catalyst converter 32 . Therefore, the downstream lambda sensor 34 increases its temperature at a greater rate, as shown in FIG. 6 by a line A. The time period of 20 seconds for the determination at the step S 2 may be predetermined from an experiment or test, not limited to 20 seconds, but may be a time period sufficient for the lambda sensor 34 to reach the active temperature.
On the other hand, if at the step S 2 , it is determined that 20 seconds has passed after the engine start (YES), since it is a state where the downstream lambda sensor 34 has reached the active temperature (see the line A in FIG. 6 ), but the upstream linear sensor 33 has not reached the active temperature (see the line B in FIG. 6 ). Therefore, the routine proceeds to a step S 8 , and determines whether or not two minutes has passed after the engine start by reading the counter described above. If it is determined that two minutes has not passed after the engine start at the step S 8 (NO), the routine proceeds to a step S 9 , and continues to stop electricity supply to the heater of the linear sensor 33 . Then, it proceeds to a step S 10 , and sets the target air fuel ratio to correspond to λ=1. After the step S 10 , the routine proceeds to a step S 11 , and computes the base fuel injection amount based on the engine speed, the desired torque and the target air fuel ratio, and computes the fuel injection amount based on the base fuel injection amount and an output signal from the downstream lambda sensor 34 (feedback control). Then, it proceeds to a step S 12 , and the engine controller 100 actuates the direct fuel injectors 14 and 24 at a desired timing without actuating the port fuel injectors 15 and 25 (direct injection). Finally, the routine proceeds to a step S 13 , and the engine controller 100 controls the EGR actuator 43 to close the EGR valve 35 . Then, the routine returns.
During the steps S 9 through S 13 , the downstream lambda sensor 34 has reached the active temperature as shown in FIG. 6 . Also, even if the exhaust gas temperature is lower and water content of the exhaust gas is likely to condense, the catalyst converter 32 , particularly the honeycomb shaped carrier of the catalyst brick, may block the water content from getting condensed on the downstream lambda sensor. Therefore, the air fuel ratio can be precisely feedback controlled to be the stoichiometry (λ=1). This feedback control is configured that the output signal by the lambda sensor 34 and a signal corresponding to the stoichiometric air fuel ratio (λ=1) are compared, and based on this comparison result, a correction amount to correct the base fuel injection amount is calculated. Alternatively, while still heavily weighting the output of the lambda sensor 34 , the output of the upstream linear sensor 33 may be taken account of to some extent for a purpose of watching the function of the lambda sensor 34 .
Then, the combustion at λ=1 raises a temperature of exhaust gas, and may promote heating of the linear sensor 33 . The time period of two minutes for the determination at the step S 8 may be predetermined from an experiment or test, not limited to two minutes, but may be a time period sufficient for the linear sensor 34 to reach the active temperature. Further, it may be number of rotations or combustion events of the engine 1 as described above.
Also, if it is determined that two minutes has passed after the engine start at the step S 8 (YES), it is a state where both of the linear sensor 33 and the lambda sensor 34 have reached the active temperatures (see the line B of FIG. 6 ). The routine proceeds to a step S 14 , and supplies electricity the heater 33 b through the heater circuit 33 d of the linear sensor 33 by the engine controller 100 closing the switching relay. Then, the heater circuit 33 d , as described above, controls the heater 33 b to maintain the linear sensor 33 at the predetermined temperature. Then, the routine proceeds to a step S 15 , and determines the engine operating condition is in which of the regions 112 , 114 , and 116 in the map 110 of FIG. 4 , based on the desired torque and the engine speed.
If it is determined at the step S 15 that the engine operating condition is in the lower speed and higher torque region 112 , the routine proceeds to a step S 16 , and sets the target air fuel ratio to be the stoichiometry (λ=1). Then, it proceeds to a step S 17 , and feedback controls the air fuel ratio (λ=1) based on the output of the upstream linear sensor 33 that has reached the active temperature as described above. This feedback control is configured that the output signal of the linear sensor 33 and a value corresponding to the stoichiometric air fuel ratio (λ=1) are compared, and based on this comparison result, a feedback amount for the base fuel injection amount is calculated.
Further the feedback correction amount to the base fuel injection amount at the step S 17 is corrected by the output of the lambda sensor 34 . That is, the output signal of the lambda air fuel ratio sensor 34 and the stoichiometric air fuel ratio (λ=1) are compared. Based on the comparison result, the feedback amount for the basic fuel injection amount is corrected. In particular, if an air fuel ratio corresponding to the output of the lambda sensor 34 is determined leaner than the stoichiometric air fuel ratio, the feedback amount by the output of the linear sensor 33 is decrementally corrected by a predetermined amount, and if the lambda sensor 34 determines it is richer than the stoichiometry, the feedback correction amount by the output of the linear sensor 33 is incrementally corrected by a predetermined amount.
After the step S 17 , the routine proceeds to a step S 18 , and the engine controller 100 actuates the direct fuel injectors 14 and 24 at a desired timing without actuating the port fuel injectors 15 and 25 (direct injection). Finally, the routine proceeds to a step S 19 , and the engine controller 100 controls the EGR actuator 43 to open the EGR valve 35 to re-circulate part of exhaust gas to the intake passage 2 through the EGR passage 4 . With this exhaust gas recirculation, the combustion temperature can be decreased to reduce the NOx emission. Then, the routine returns.
If it is determined at the step S 15 that the engine operating condition is in the lower speed and lower torque region 114 , the routine proceeds to a step S 20 , and sets the target air fuel ratio to be an air fuel ratio leaner than the stoichiometry (λ=2). Then, it proceeds to a step S 21 , and feedback controls the air fuel ratio (λ=2) based on the output of the upstream linear sensor 33 that has reached the active temperature as described above. This feedback control is configured that the output signal of the linear sensor 33 and a value corresponding to the target lean air fuel ratio (λ=2) are compared, and based on this comparison result, a feedback amount for the base fuel injection amount is calculated.
FIG. 7 shows a relationship between NOx emission and an excess air ratio λ. The NOx emission increases from a little more than λ=1 corresponding to the stoichiometric air fuel ratio to λ=1.3. Then, it decreases to approximately zero around λ=1.8-2.0. Accordingly, when the operating condition is in the lower speed and lower torque region 112 , the target air fuel ratio will be set corresponding to λ=2 for the substantially zero NOx emission.
After the step S 21 , the routine proceeds to a step S 22 , and the engine controller 100 actuates the direct fuel injectors 14 and 24 at a desired timing without actuating the port fuel injectors 15 and 25 (direct injection). Finally, the routine proceeds to a step S 23 , and the engine controller 100 controls the EGR actuator 43 to close the EGR valve 35 . Then, the routine returns.
If it is determined at the step S 15 that the engine operating condition is in the higher speed region 114 , the routine proceeds to a step S 24 , and sets the target air fuel ratio to be an air fuel ratio leaner than the stoichiometry (λ=1.4-1.6). Then, it proceeds to a step S 25 , and feedback controls the air fuel ratio (λ=1.4-1.6) based on the output of the upstream linear sensor 33 that has reached the active temperature as described above. This feedback control is configured that the output signal of the linear sensor 33 and a value corresponding to the target lean air fuel ratio (λ=1.4-1.6) are compared, and based on this comparison result, a feedback amount for the base fuel injection amount is calculated. Then, the routine proceeds to a step S 26 , and the engine controller 100 actuates the direct fuel injectors 14 and 24 and the port fuel injectors 15 and 25 at respective desired timings (direct injection plus port injection). At the same time, the engine controller 100 controls the throttle actuator 42 to regulate intake airflow to the engine 1 , thereby causing the direct fuel injectors 14 and 24 , the port fuel injectors 15 and 25 and the throttle valve 31 to function collectively as the air-fuel regulator to adjust the air-fuel mixture supplied to the engine 1 . Finally, the routine proceeds to a step S 27 , and the engine controller 100 controls the EGR actuator 43 to close the EGR valve 35 . Then, the routine returns.
As described above, in an engine start, electricity supplied to the heater 33 b of the upstream linear sensor is stopped at the step S 3 or S 8 until two minutes after an engine start when it is supposed that the upstream linear sensor 33 has reached the active temperature and there is substantially no condensed water on the surface of the upstream linear sensor. Therefore, the linear sensor 33 may not have any distortion on its surface due to the condensed water and the heater.
During this two minute period, the downstream lambda sensor 34 arranged has substantially no condensed water on its surface thanks to the catalyst converter 32 arranged upstream of the downstream lambda sensor 34 . Also, the exhaust gas reacted and heated at the catalyst converter 32 may cause the lambda sensor 34 to more quickly reach the active temperature so that the air fuel ratio can be precisely feedback controlled based on the output of the lambda sensor 34 .
In the embodiment above, the oxygen sensors 33 and 34 are supposed to reach the respective active temperatures by determining a time period since an engine start at the steps S 2 and S 8 . Alternatively, a temperature sensor may be provided and detect a temperature of the linear sensor 33 or the lambda sensor 34 . Then, at the step S 2 or S 8 of the control routine of FIG. 5 , it may be determined whether or not the detected temperature of the sensor 33 or 34 is higher than a predetermined temperature. Further alternatively, the temperatures of the sensors 33 and 34 may be estimated based on cumulated rotations of the engine 1 since an engine start, cumulated fuel injection amount since an engine start, other parameters including the time period since an engine start, an engine temperature, and an atmospheric temperature, or a combination of any of the above.
The engine 1 is not limited to the rotary piston engine, but may be any type of internal combustion engines including a spark ignited engine having a reciprocating piston with direct fuel injection or port fuel injection. The fuel supplied to the engine is not limited to the gaseous hydrogen described above, but it may be hydrocarbon based fuels including gasoline, diesel oil and ethanol.
The upstream sensor 33 is not limited to the specific type of linear sensor described above, but may be a different type of sensor showing a linearity of the output without the oxygen pump element, or a lambda sensor like the downstream sensor 34 if the target air fuel ratio is always set the stoichiometry.
The heater 33 b and the heater circuit 33 d are not limited to the above described. Specifically, instead of turning on and off the electricity to the heater, the engine controller 100 may adjust the electricity by controlling a power transistor such as the transistor 33 r in FIG. 3 . In that case, instead of stopping the electricity to the heater 33 b at the steps S 3 and S 9 , small amount of electricity can be supplied to the heater 33 b . That amount is much smaller than what may be supplied at the step S 14 . Then, the upstream linear sensor can more quickly reach the active temperature without a risk of the excessive surface distortion.
While in the above embodiment, the downstream sensor 34 does not have any heater, the sensor 34 may have an electric heater. Since the downstream sensor 34 is arranged downstream of at least one brick of the catalyst converter 33 which blocks water from condensing on the sensor 34 , the heater of the downstream sensor 34 may be activated just after an engine start so that an air fuel ratio feedback control can be started further earlier.
It is needless to say that the invention is not limited to the illustrated embodiments and that various improvements and alternative designs are possible without departing from the substance of the invention as claimed in the attached claims. | A method of controlling an internal combustion engine system. The method comprises supplying a first amount of electric energy to heat to an upstream sensor located in an exhaust gas passage upstream of an exhaust gas after-treatment device and adjusting an air-fuel mixture supplied to the internal combustion engine based on an output of the upstream sensor during a first engine operating condition, and supplying a second amount of electric energy, which is smaller than the first amount, to heat the upstream sensor and adjusting the air-fuel mixture based on an output of a downstream sensor located in the exhaust gas passage and downstream of the exhaust gas after-treatment device during a second engine operating condition. | 5 |
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application 60/492,288, filed Aug. 5, 2003, the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to telephony, and more particularly to a method and a system for detecting when a party has been added to a pre-existing telephone call.
BACKGROUND OF THE INVENTION
[0003] Modern phone companies offer a number of convenient services to their customers. One such service is called conference-calling, third-party calling or “three-way” calling. This allows an originating caller and a recipient caller, who establish a conversation, to engage the phone system to dial and connect a third party into the conversation as well.
[0004] Three-way calling is a convenient feature in many situations, but poses a problem in others. Imates in correctional facilities have the ability to originate phone calls to others, but typically are not able to call those numbers on a given inmate's “restricted-number” list. Persons on the restricted list may include judges, prosecutors, other lawyers, victims of the inmate's crimes, or even other family members (especially in the case of protection-from-abuse (PFA) cases). By using three-way calling, inmates are able to contact people on these restricted lists. They first call a number not on the restricted list (a friend, for example), then have the friend perform a three-way call to the restricted number.
[0005] Although current prior art and patented devices attempt to solve the three-way call problem, they all suffer from one major limitation; namely, they are not 100% effective at detecting such calls. Inventions such as this are useful in correctional-institutes telephony markets, but some percentage of inmate calls (as much as 10%, 20%, or even 30%) which use three-way calling to get another party on the line, in violation of call-restriction rules, will get past the modern three-way call-detection system undetected and on to the intended party. Commercial pressures exist for the accuracy rates to be higher, and if possible, to be 100% to handle those calls that escape detection by present equipment and techniques.
SUMMARY OF THE INVENTION
[0006] Particular implementations of the present invention, which have yielded reliable and accurate three-way call detection systems and methods, will now be described. These present inventions use steganography to create efficiencies and improve the reliability of three-way call detection.
[0007] Disclosed herein is a three way call detection system for detecting the addition of a third party to an pre-existing telephonic connection between a first party and a second party, said system comprising an ID generator for generating identification data; a spread spectrum modulator for imposing the identification data onto a carrier signal, said modulator outputting a modulated identification signal having frequency components that are capable of being transmitted via a telephonic connection; a source telephone for participating in a telephone conversation; a signal combiner for adding the modulated identification signal to the telephone conversation to form an encoded telephone signal, the modulated identification signal being imperceptible to a human listener of the telephone conversation; a remote telephone for receiving the encoded telephone signal; and a spread spectrum demodulator for demodulating the modulated identification signal to extract the identification data. The identification data preferably is selected from the following: a personal identification number, a user number, an inmate identification number, a user name, data identifying the local telephone exchange of the source telephone, a telephone number of the source telephone, and data identifying the institution where the source telephone is located. The system further may comprise a processor for extracting the modulated identification signal from the encoded telephone signal. The spread spectrum modulator may impose the identification data onto a carrier signal by subdividing the identification data into a plurality of subdivisions and encoding the plurality of subdivisions on a plurality of frequency bands using a predetermined sequence. The spread spectrum demodulator optionally may demodulate the modulated identification signal, extract the plurality of subdivisions of the identification data and assemble the plurality of subdivisions of the identification data into the identification data using the predetermined sequence. The predetermined sequence preferably is a predetermined pseudo-random code. The system further may comprise a code generator for generating a pseudo-random code, and the predetermined sequence may be a pseudo-random code generated by the code generator. The signal combiner passively may add the pseudo-random code to the telephone conversation at a predetermined plurality of frequencies.
[0008] Also disclosed herein is a method for detecting the addition of a third party to an pre-existing telephonic connection between a first party and a second party, comprising generating identification data; subdividing the identification data into a plurality of subdivisions; encoding the plurality of subdivisions on a modulated identification signal, the modulated identification signal comprising the subdivisions of the identification data encoded on a plurality of frequency bands using the predetermined sequence; adding the modulated identification signal to a telephone signal to form an encoded telephone signal, the modulated identification signal being imperceptible to a human listener of the telephone signal; transmitting the encoded telephone signal across a telephonic connection; receiving the encoded telephone signal at a remote location; extracting the modulated identification signal from the encoded telephone signal; and demodulating the modulated identification signal to extract the plurality of subdivisions of the identification data; and assembling the plurality of subdivisions of the identification data to re-create the identification data using the predetermined sequence.
[0009] Also disclosed herein is a system for identifying a source telephone, said source telephone having identification data associated therewith, the system comprising a spread spectrum modulator for encoding the identification data into a spread spectrum signal using a spreading code; and a telephone interface for coupling to a telephone to add the spread spectrum signal to an output of the telephone. The system further may comprise a processor for coupling to a telephone to extract identification data using a spread spectrum demodulator and a spreading code. The spread spectrum modulator may be a selected one of a BPSK modulator, an MPSK modulator, and a QPSK modulator. The telephone interface may be coupled to a selected one of a telephone handset, a TIP/RING pair of a standard analog POTS line, and a digital telephone interface. The telephone interface preferably passively adds the spread spectrum signal to a telephone signal by a selected one of transformer coupling and capacitive coupling.
[0010] Also disclosed herein is a system for decoding a modulated identification signal imbedded in a telephone signal wherein the identification signal is capable of identifying a source of the identification signal, the system comprising a receiver for receiving a telephone signal, which telephone signal comprises an audio signal and a modulated identification signal, said modulated identification signal having identification data embedded therein; and a spread spectrum demodulator for demodulating the modulated identification signal to extract the identification data. The system further may comprise a processor, coupled to the receiver, for extracting the modulated identification signal from the telephone signal. The system further may comprise a comparator for comparing the identification data to a predetermined set of restricted data; and a restricted call response module for executing at least a selected one of the following responses if the identification data matches any of the predetermined set of restricted data: (1) turning off a microphone of a telephone, (2) disconnecting a telephone call, (3) recording any conversation that may occur on a call, (4) playing a prerecorded message, (5) recording call data, (6) disabling the speaker of a telephone, and (7) adding a disruptive signal to a telephonic connection. The system further may comprise a code generator for generating a pseudo-random code; a spread spectrum modulator for imposing the identification data onto a carrier signal using the pseudo-random code, said modulator outputting a modulated identification signal having frequency components that are capable of being transmitted via a telephonic connection; and a signal combiner for adding the modulated identification signal to an audio signal of a telephone microphone, said combiner producing a telephone signal as an output.
[0011] Also disclosed herein is a method for identifying a source telephone comprising providing a data identification pattern for identifying a source telephone; generating a reference spreading code using a random number generator; encoding the data identification pattern into an identification signal using the spreading code and a spread spectrum modulator, thereby generating a modulated identification signal; combining the modulated identification signal with an audio signal of a microphone output of a telephone to form a composite telephone signal, the modulated identification signal being imperceptible to a human listener of the composite telephone signal; and transmitting the composite telephone signal across a telephonic connection. The method further may comprise receiving the composite telephone signal from a source telephone at a remote location; multiplying the composite telephone signal by the reference spreading code to form a signal product; filtering or correlating the signal product to extract the modulated identification signal from the digital data; comparing the modulated identification signal with a predetermined set of restricted data signals to determine if the modulated identification signal matches at least one of a predetermined set of restricted data signals. The method further may comprise performing an envelope detection on the filtered signal product, if needed; and comparing the output of the envelope detection with a threshold value to determine if the signal product matches at least one of a predetermined set of restricted data signals. The method further may comprise initiating a restricted call response if the signal product matches at least one of a predetermined set of restricted data signals, the restricted call response being selected from the group of following choices: (1) turning off a microphone of a telephone, (2) disconnecting a telephone call, (3) recording a call, (4) playing a prerecorded message, (5) recording call data, (6) disabling the speaker of a telephone, and (7) adding a disruptive signal to a telephonic connection. The step of receiving the composite telephone signal further may comprise providing an analog-to-digital converter; and converting the composite telephone signal from an analog signal to a digital signal. The method further may comprise demodulating the modulated identification signal to extract the data identification pattern using a reference spreading code.
[0012] Also disclosed herein is a method for identifying a source of a telephone signal received by a remote telephone comprising receiving a composite telephone signal from a source telephone at a remote location, the composite telephone signal comprising an audio signal representative of a telephone conversation and a modulated identification signal, the modulated identification signal having identification data that was embedded therein using a reference spreading code; extracting the modulated identification signal; and analyzing the extracted modulated identification signal to determine if the identification signal contains data that matches at least one of a predetermined set of restricted data signals. The step of extracting the modulated identification signal further may comprise multiplying the composite telephone signal by the reference spreading code to form a signal product; and extracting the modulated identification signal. The method preferably comprises initiating a restricted call response if the signal product matches at least one of a predetermined set of restricted data signals, the restricted call response being selected from the group of following choices: (1) turning off a microphone of a telephone, (2) disconnecting a telephone call, (3) recording a call, (4) playing a prerecorded message, (5) recording call data, (6) disabling the speaker of a telephone, and (7) adding a disruptive signal to a telephonic connection. The step of receiving the composite telephone signal further may comprise providing an analog-to-digital converter; and converting the composite telephone signal from an analog signal to a digital signal. The method further may comprise demodulating the modulated identification signal to extract the identification data using a reference spreading code.
[0013] Also disclosed herein is a three way call detection system for detecting the addition of a third party having a third phone to an pre-existing telephonic connection between a first party having a first phone and a second party having a second phone comprising an ID generator for generating identification data; a spread spectrum modulator for imposing the identification data onto a carrier signal, said modulator outputting an identification signal having frequency components that are capable of being transmitted via a telephonic connection; a signal combiner for adding the identification signal to an output from a microphone of the first phone, thereby producing a combined output signal, said identification signal being added at a level that is imperceptible to a human ear that hears the combined output signal; a signal receiver coupled to a third phone, for receiving the combined output signal after transmission across a telephonic connection from the first phone to the third phone; a spread spectrum demodulator for demodulating the identification signal to extract the identification data; and a processor to analyze the identification data. The output from the microphone may comprise a digital signal and the signal combiner may comprise a selected one of a digital adder or a microcontroller that digitally adds the identification signal to the output from the microphone. The output from the microphone may comprise an analog signal and the signal combiner may comprise a transformer for coupling the identification signal to the output from the microphone. The system further may comprise a digital signal processor coupled to the signal receiver for extracting the identification signal from the combined output signal. The processor preferably analyzes the identification data to determine whether the connection is authorized. The third phone optionally is a component of a local telephone system, and the processor optionally analyzes the identification data and reports its analysis to the local telephone system. The combined output signal may travel a telephonic connection between the first phone to the second phone, and travels a telephonic connection between the second phone and the third phone.
[0014] Also disclosed herein is a detection system for detecting a telephonic connection between a first phone and a second phone comprising an ID generator for generating identification data; a spread spectrum modulator for imposing the identification data onto a carrier signal, said modulator outputting an identification signal having frequency components that are capable of being transmitted via a telephonic connection; a signal combiner for adding the identification signal to an output from a microphone of a first phone, thereby producing a combined output signal, said identification signal being added at a level that is imperceptible to a human ear that hears the combined output signal; a signal receiver for receiving the combined output signal after transmission across a telephonic connection; a spread spectrum demodulator for demodulating the identification signal to extract the identification data; and a processor to analyze the identification data. The system further may comprise a digital signal processor coupled to the signal receiver for extracting the identification signal from the combined output signal. The first phone may be a restricted phone, and the processor may determine whether the connection between the restricted phone and the second phone is unauthorized. The processor may be coupled to the second phone, and upon the detection of an unauthorized connection, the processor may cause one or more of the following actions to occur: a) recording a conversation between the restricted phone and the second phone; b) terminating the connection between the restricted phone and the second phone; c) disabling a speaker of the second phone; d) adding an audible disruptive signal to the telephonic connection; and e) adding an audible warning message to the telephonic connection. The second phone may be a restricted phone, and the processor may determine whether the connection between the first phone and the restricted phone is unauthorized. The processor may be coupled to the second phone, and upon the detection of an unauthorized connection, the processor may cause one or more of the following actions to occur: a) recording a conversation between the restricted phone and the second phone; b) terminating the connection between the restricted phone and the second phone; c) turning off a microphone of the restricted phone; d) adding an audible disruptive signal to the telephonic connection; and e) adding an audible warning message to the telephonic connection. The signal receiver may be coupled to a third phone that is a component of a local telephone system, and the processor may analyze the identification data and report its analysis to the local telephone system.
[0015] The present invention overcomes the problems and disadvantages associated with conventional systems and methods, and provides improved systems and methods whereby the additions of new parties to a telephone call may be detected.
[0016] Other embodiments and advantages of the invention are set forth in part in the description that follows, and in part, will be obvious from this description, or may be learned from the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 represents a block diagram of one embodiment of the transmitter portion of the present invention. FIG. 1 shows five distinct subsystems: the data ID pattern, the random number generator, the spread spectrum modulator, the drive circuitry, and the phone interface.
[0018] FIG. 2 illustrates the operation of a BPSK Modulator of one embodiment of the present invention.
[0019] FIG. 3 represents a block diagram of one embodiment of the receiver portion of the present invention. FIG. 3 shows three distinct subsystems: the signal interface, code acquisition & tracking, and the data demodulator.
[0020] FIG. 4 represents an expanded block diagram of the embodiment of FIG. 3 showing the elements of the code acquisition & tracking subsystem.
[0021] FIG. 5 represents a sample spectral plot of 4095 1-bit samples coming out of a 12-bit LFSR noise generator used in one embodiment of the present invention.
[0022] FIG. 6 represents a sample plot of a speech waveform used in testing of one embodiment of the present invention.
[0023] FIG. 7 represents a plot of the speech samples as in FIG. 6 , but with the 12-bit LFSR noise sequence of FIG. 5 added to it.
[0024] FIG. 8 represents a sample plot of the results of correlating the 4095 sample PRN sequence of FIG. 5 with the signal+noise waveform of FIG. 7 and the PRN sequence itself.
[0025] FIG. 9 represents a sample plot of the results of a correlation between the clean speech signal of FIG. 6 and the PRN sequence of FIG. 5 .
[0026] FIGS. 10-13 illustrate four possible operating modes for the present invention: (1) on a typical wired telephone, attached to an analog POTS phone line as shown in FIG. 10 and FIG. 13 ; (2) between a telephone and its handset as shown in FIG. 11 ; (3) with an external microphone and a cellular phone as shown in FIG. 12 ; and (4) attached to an analog POTS phone line with multiple wired telephones as shown in FIG. 13 .
DETAILED DESCRIPTION OF THE INVENTION
[0027] When an end-user listens to a signal such as a radio station, he adjusts his radio set to a number, for example 91.5, on the FM band. For the FM band, the 91.5 means 91.5 MHz, which is the frequency of the signal carrying the music (or “carrier” frequency).
[0028] Each radio station transmits its music or other content on a separate carrier frequency, such as 91.5 MHz, 91.7 MHz, or 96.3 MHz. The end-user selects a desired station by tuning the radio to receive a predetermined carrier frequency. The advantage of such a transmission system is its simplicity, which leads to very low cost products.
[0029] The disadvantage comes when you need to send a signal between multiple points, say between two soldiers in the field, in such a way that no one else can pick up the signal. If one soldier sent the signal at one frequency, 150 MHz, and the other soldier tuned his radio to the same 150 MHz, he would receive the signal. But, so would everyone else who tuned his or her radio to 150 MHz as well. This is the situation that spread spectrum was invented to solve.
[0030] The idea behind direct sequence spread spectrum is to take a signal that needs to be transmitted, to electronically take the power that normally would lie at a fixed frequency (i.e. 150 MHz), to divide the signal into many subdivisions, and to transmit each one at a different frequency at much lower power levels for each frequency. For a more detailed discussion of steganography, see U.S. Pat. No. 6,330,335, which patent is hereby incorporated by reference in its entirety.
[0031] The receiving device in this situation needs to know exactly how the signal was subdivided in the first place, so it can gather all the pieces from the various frequency bands and reconstruct the signal. Since an eavesdropper needs to know: (1) where all the pieces of the signal are placed after being subdivided; (2) exactly how to put them all back together correctly; and (3) have the technical competence to gather up all the signal subdivisions across wide frequency bands, it makes intercepting the signal(s) extremely difficult.
[0032] Since the subdivisions of the signal are all transmitted at much lower signal levels (volume) than the original signal, they can be easily hidden inside of another signal, such as a telephone conversation.
[0033] Any spread spectrum or other communication system consists of at least two parts: a transmitter and a receiver. The receiver portion can be implemented any number of ways; either within the phone system or outside of it; either by hardware equipment and minimal software, or by normal phone company hardware and lots of software.
[0034] The present invention will transmit a known set of data patterns onto the POTS phone line of an attached telephone, using direct sequence spread spectrum (DSSS). The resulting amplitude of the DSSS signal is low enough so as to be virtually imperceptible to either the originator or the recipient of the phone call.
[0035] As will be clear to one of ordinary skill in the art, the present invention has applications outside of 3-way call detection. Caller-ID, for example, identifies a phone line and not an individual phone, which is of limited utility considering the rapid proliferation of cell phones. This invention—if embedded in cell phones—could identify the phone identity as well as (w/caller ID) the phone number being used by it.
[0036] Furthermore, it can be used to send data over the phone lines as a person is talking, without their knowledge. For example, a modification of the present invention could be hooked to sensors for gas and electric meters. A consumer can simply place a call to the electric company; listen to a recording, and in the meantime, meter readings are sent right to the utility's computers, eliminating the need for meter readers.
[0037] In a preferred embodiment of the present invention as shown in FIG. 1 , the block marked “Data ID Pattern” contains digital codes that the user of the present invention wishes to pass from a phone being monitored to another phone or system. Example codes include a serial number and a short digital string such as “XYZ Company, Model ABC, Serial No. 123456.” These digital codes are preferably unique to the particular phone line and are stored in the invention in a non-volatile memory such as an EPROM, PROM or EEPROM. In the correctional institution context, an inmate is preferably required to enter a user ID or access code to gain access to the inmate telephone system. In that case, the embedded Data ID Pattern will preferably uniquely identify the inmate as the source of the original phone call. This can be accomplished either by generating an inmate specific code or by appending the user ID or other inmate specific code to the phone-line-unique code. As part of device operation, the patterns are sent to the “spread spectrum modulator” block to be encoded and transmitted across the phone line.
[0038] The receiver portion of the present invention preferably is installed on a restricted destination phone, such as a phone belonging to a judge, prosecutor, or victim. If an inmate-unique or a phone-line-unique Data ID Pattern is identified by the present invention in a call received at one of the above restricted destination phones, this will indicate that an inmate has placed a three-way call to that restricted phone in violation of institutional calling restrictions, or otherwise managed to bypass the phone restrictions of the inmate telephone system. Appropriate action, such as terminating or recording the phone call, can then be taken. An advantage of an inmate-unique identifier is that it permits calls to particular numbers to be restricted by individual inmate and allows the inmate originator of a restricted call to immediately be identified, and not just the originating phone line within the prison.
[0039] The block marked “random number generator” is an integral part of a spread spectrum system. Its purpose is to generate a random or pseudo-random number, referred to interchangeably as random numbers herein, to provide the order in which the pieces of the signal are subdivided or modulated and sent to the spread spectrum receiver. The more random the generator, the tougher it is to intercept, recover and reconstruct the transmitted signal at the receiver device. If the generator doesn't produce numbers that are very random, it will be relatively easy to intercept the transmitted signal (and data ID pattern), as well as easy to reconstruct the signal at the receiving device. Depending on the desired performance of the system, the randomness of the generator can be adjusted accordingly.
[0040] The block marked “spread spectrum modulator” is the method used to produce a modulated random signal containing the Data ID Pattern for transmission across the phone line. This invention preferably uses a BPSK modulator for its simplicity, low cost, and ease of use when transmitting digital data. Other modulators such as MPSK or QPSK can also be used.
[0041] The output from the BPSK modulator is applied to driver circuitry as shown in FIG. 1 ; such drivers also contain bandpass filtering. The modulated output resembles random-noise, and with the appropriate driver amplitude, can be driven onto a phone line with a level that is just barely perceptible, or even imperceptible, to most listeners.
[0042] Two possible implementations of the block marked “Phone Interface” on the block diagram are: (1) attaching the device to the handset of a telephone, and (2) attaching the device to the TIP/RING pair of a standard analog POTS (Plain Old Telephone System) line. In both implementations, the circuitry preferably is designed in such a way that the steganographic signal (spread spectrum-modulated Data ID Patterns or data) is passively added to the existing conversation on the line. For analog POTS phones, the steganographic signal preferably is transformer coupled onto the phone line. For digital phones, the digital values of the spread spectrum code preferably are added to the digital data representing a phone call. The analog circuit preferably uses a transformer to perform the passive adding function, while the digital circuit preferably uses a digital adder or a microcontroller running software that performs the add operation. Generally, it is not desirable for correctional institutions to modify the signals of conversations of its inmates. A recording of a conversation that has been manipulated may be excluded from use in a courtroom, and thus, for at least this reason, it is preferred that the steganographic signal is passively added to the phone lines so as to not jeopardize the integrity of the underlying conversation. Thus, this invention preferably uses transformer- or capacitive-coupling to passively add the steganographic signal to any existing conversations.
[0043] The block marked “Signal Interface” in FIG. 3 preferably consists of digital telecom circuitry comprising filtering, an Analog-to-Digital (A/D) converter (preferably implemented with a telecom codec), and other control circuitry to output digital data representing a received telephone signal. In modern, all-digital phone systems, the filtering and A/D converter just described aren't required, so the signal interface comprises just control circuitry, as in a T1 telecom interface.
[0044] The block marked “Data Demodulator” performs the function of extracting transmitted data from the spread spectrum signal and presenting it to the controlling correctional telephony system and computer(s). Decisions can be made by the controlling system, based on this received data, as to whether to continue or cancel the call, whether to start a recording device or not, or to take other appropriate actions.
[0045] The block marked “Code Acquisition & Tracking” is the most important, and most difficult, part of a spread spectrum receiver to implement. A typical Code Acquisition & Tracking function is shown in FIG. 4 .
[0046] Refer back to FIG. 1 and notice the block marked Random Number Generator. Remember that this random number is key to spread spectrum modulation, or “spreading” of the transmitted signal across the transmission bandwidth. The same random number sequence is required in the receiver, and is shown in FIG. 4 marked as “Reference Spreading Code.” The same sequence is used for both spreading and despreading.
[0047] The Reference Spreading Code function is shown with two variable parameters that affect the sequence being multiplied by the received signal—namely, Frequency and Phase. The Frequency parameter affects the rate of the random number generator's clock. This is required when oscillator instabilities and drift cause the clocks on the transmitter to differ slightly from those on the receiver. The Phase parameter affects the starting sequence loaded into the random number generator of the receiver or its sequence position compared to the same generator on the transmitter.
[0048] After being multiplied by the random number sequence and bandpass filtered, the received signal passes through an energy detector, which typically performs an envelope detection. The output of the envelope detection is compared to a threshold value and a “HIT” decision is made. If the detected output is above a pre-determined (or variable) threshold, a decision is made that the correct code acquisition sequence has been hit. Otherwise the HIT output is false.
[0049] If the code acquisition has not been hit (the HIT output is false), adjustments to the frequency and/or phase parameters may be made to help accelerate the likelihood of a hit occurring, or to decrease the time needed to detect the random number sequence phase whereby a hit occurs.
[0050] The bases for changing these parameters are well documented in the literature, and form a number of algorithms by which code acquisition can be made more robust and/or faster. Some examples of potential algorithms include: single search algorithms; single dwell and multiple dwell algorithms, and recursion-aided sequential estimation (RASE) algorithms. Each of these algorithms has its associated advantages and disadvantages, and thus, one may be preferred over others in any given situation depending on the characteristics of the processing circuitry available in the receiver, allowable cost of the receiver circuitry, and other factors.
[0051] The characteristics of the random number (RN) generator used in both the transmitter and the receiver play a significant role in the required performance of the spread spectrum receiver. RN generators are available which generate very long sequences before repeating, and others are available with very short sequences. If a single-search code acquisition algorithm is used, for example, all possible phase settings for a given RN sequence are correlated with the received signal in an attempt to get a hit. For long sequences, this can take a very long time or require tremendous amounts of circuitry. For short sequences, the task will be more reasonable.
[0052] Longer sequences provide more resistance to jamming, and provide less chance of having the signal intercepted and decoded. Shorter sequences provide less jamming protection and less security when intercepted, but also require less circuitry, leading to lower-cost products.
[0053] Besides simply the length of the RN sequence affecting its performance, the mathematical structure of the code affects its performance. Such sequences as Barker Codes, Gold codes and others are well documented in the literature.
[0054] In one preferred embodiment, a 12-tap Linear Feedback Shift Register (LFSR) is used as a pseudorandom noise (PRN) source, as is well known in the art. A LFSR design can be selected with an arbitrary number of bits, but the more bits used, the longer the random number sequence before it repeats and starts over again. Security systems and Government radios typically use LFSR sequences with 40, 50, or even 60 bit LFSR circuits so the random numbers don't repeat for hundreds of years—providing a good level of security in the radio link.
[0055] For the present invention, it is desirable for the PRN sequence to repeat to make the demodulation circuitry and software easier and more cost-effective. A 12-bit LFSR circuit generates a pseudorandom pattern that repeats every 4095 clock cycles. For example, with an 8 kHz clock rate, the pattern will repeat approximately every±2 second, allowing a 3-way call detection system to detect the call more than once every second.
[0056] FIG. 5 shows a spectral plot of the 4095 1-bit samples coming out of the 12-bit LFSR noise generator. The spectral shape is substantially flat. This gives the PRN signal a very good “white-noise” sound when added to a telephone conversation. This signal is almost undetectable when the amplitude levels are set correctly and added to phone conversations. Typical POTS phone systems have an approximately 40-45 dB dynamic range.
[0057] In summary, the spread spectrum receiver used with the present invention can be a standard DSSS receiver that implements any number of algorithms for its code-acquisition and tracking functions. The required demodulator is preferably a BPSK type, and the input signal is preferably digital, having been processed by telephony circuitry and passed through telephony codecs.
[0058] A number of tests were conducted to validate the effectiveness of one embodiment of the present invention. The test system was equipped with handset and phone line interfaces and utilized a microcontroller programmed with detection software that is designed to run continuously and output a digital bit (one or zero) every 125 μsec (which equates to an 8 kHz output rate). Each digital bit is output as the result of a Pseudo-Random Noise Generator (“PRN generator”), implemented in software. The PRN consisted of a single data register (implemented as a software variable) with feedback. The timing of the software is important, as the calculations on the PRN register must be completed in time for a valid bit to be output at the desired interval, which was 125 μsec for the test embodiment. Timing can be verified by using an oscilloscope to monitor a debug pin on the microcontroller, which is toggled every 125 μsec. The microcontroller used for the foregoing tests had internal RAM for variables, FLASH for storing the program, I/O pins for toggling the required signals, and an internal timer for measuring the 125 μsec period. MATLAB was used for the DSP and signal processing portion of the system design. Segments of speech from the industry standard “TIMIT” speech database were used for testing. TIMIT is a collection of carefully chosen speech utterances that have special phonetic qualities that stress speech recognition systems and is widely used for speech research. The database comprises 10 spoken sentences for each of 420 speakers, some male and some female. FIG. 6 shows a plot of the speech waveform used in this testing. FIG. 7 shows a plot of the speech samples as in FIG. 6 , but with the 12-bit LFSR noise sequence added to it.
[0059] FIG. 8 shows the results of correlating the 4095 sample PRN sequence with the signal+noise waveform and the PRN sequence itself. Each of the vertical “spikes” in FIG. 11 represents a point in time (during exactly ONE sample period of the 8 kHz clock) where the PRN noise sequence of the present invention and the noise in the signal are in perfect phase, causing the correlation output to jump up to a maximum value. Each of the spikes occur 4095 samples apart, because that is the repetition interval of the LFSR noise generator in the tested embodiment. The dashed line on FIG. 8 is an example threshold that is preferably set in the system software portion of the demodulator to indicate when a three-way call has been detected.
[0060] FIG. 9 shows the results of a correlation between the clean speech signal and the PRN sequence. FIG. 9 maintains the same relative scaling as FIG. 8 . Because the speech waveforms are not well correlated to the PRN noise sequence, the correlation peaks of FIG. 9 have a significantly lower magnitude than those of FIG. 8 . In the absence of the PRN signal, as would be the case when there is no three-way call taking place, even the correlation peaks do not exceed the detection threshold.
[0061] FIG. 10 shows the invention used with a typical POTS (plain old telephone system) analog telephone. Telephone 1 is connected to the incoming phone line 4 by means of a standard 2-wire or 4-wire phone cable 2 . Invention 3 is also connected to the incoming phone line by means of a similar cable. Circuitry within invention 3 allows it to generate a signal that also gets driven onto the phone line 4 along with the signal from the telephone 1 . The scenario shown in FIG. 10 can also be used with cordless (but not wireless cellular) phones. Attaching invention 3 to the phone line 2 can be done with a cordless phone 1 as well as with a standard old-style (handset attached to the base) telephone.
[0062] An alternative scenario is shown in FIG. 11 where the invention 5 is connected between the phone 7 and its handset 6 . This scenario can be used for single-phone installations where only a single phone needs the invention and not all the phones on a POTS line as shown in FIG. 11 . This scenario also has advantages in physical size and not requiring FCC compliance, which can help reduce its development and production costs.
[0063] The invention can also be used with wireless (cellular) phones, as shown in FIG. 12 . Invention 11 is attached to a microphone 9 by means of a microphone cable 10 , as well as to the cell phone 13 by means of another cable 12 . Invention 11 receives the signal from the microphone 9 as the user speaks, adds the steganographic signal to the microphone signal, and then drives the resulting signal into cell phone 13 for transmission.
[0064] FIG. 13 shows a scenario similar to FIG. 11 , but for a multiple-phone installation such as in a home or business. Invention 16 generates the steganographic signal and drives it onto the phone line 15 along with the signal from one or more phones 14 for transfer to the POTS line 17 .
[0065] Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The specification and examples should be considered exemplary only with the true scope and spirit of the invention indicated by the following claims. As will be understood by those of ordinary skill in the art, variations and modifications of each of the disclosed embodiments can be easily made within the scope of this invention as defined by the following claims. | Three-way call detection is an important component of correctional facility telephone equipment because it helps restrict calling access by certain persons to certain restricted telephone numbers. Various three-way call detection methods exist, but all of these implementations suffer from one major limitation—the detection accuracy is not as high as is desired by the industry. The present invention improves detection accuracy, using “steganography.”Steganography involves hiding one set of data or signals within another signal or carrier in such a way that its presence is virtually imperceptible to the end recipient, and potential even the originator of the carrier signal. Television producers use steganographic methods to encode data in video signals for security, distribution monitoring, piracy-control, and other reasons. The present invention involves a device that connects to a telephone, either at the line or handset interfaces, and produces a known signal that is steganographically hidden within the user's normal voice signal. Detection equipment, residing at another location, monitors signals on telephone calls and tests for the presence of the hidden signal or data generated by the invention. Once detection is achieved, appropriate action, such as terminating or recording the call, may be taken. Improved accuracy is achieved by choosing the appropriate hidden signal(s)—ones that never occur in the course of normal conversation and never get generated by telephone company equipment. Once detected, the presence of the signal guarantees the call was made to the restricted party from a particular phone line. | 7 |
TECHNICAL FIELD
The invention relates to a gas bag module for a vehicle occupant restraint device.
BACKGROUND OF THE INVENTION
Gas bag modules usually have a gas generator and a gas bag with a wall, and a diffusor which surrounds the gas generator and has a cup-shaped section. The diffusor and the gas generator are distinct, separate components.
In order to increase the safety of gas bags which are filled by means of pyrotechnic gas generators, among other things provision may be made to clean the gas, flowing out from the gas generator, from particles. By flowing through the filter, the temperature of the gas arriving into the gas bag is also reduced.
It is an aim of the invention to achieve such a function with a gas bag module which is favorably priced and is simple to manufacture.
BRIEF SUMMARY OF THE INVENTION
According to the invention, a gas bag module for a vehicle occupant restraint device comprises a gas generator and a gas bag having a wall. The module further includes a diffusor which surrounds the gas generator and has a cup-shaped section. The cup-shaped section has a filter section consisting of at least one fiber, through which filter section gas flows out from the gas generator. In prior art, the diffusor always had outflow openings which were very large, so that no filter function was provided. Therefore also none of the particles released on combustion of pyrotechnic material were retained in the diffusor. The invention makes provision that the cup-shaped diffusor, which usually consists of a side wall, a cover and a ring-shaped flange projecting outwards on the edge of the side wall opposite the cover, is used for cooling and filtering the gas. Thus, it is either possible to arrange a smaller dimensioned filter inside the gas generator which has a closed outer housing, or to do without a filter at all. The good filter action of the diffusor is achieved in that the filter section consists of one or more fiber(s), for example made of a textile, knitted mesh, knitted or woven fabric or a fleece or an irregular connection of the one or more fiber(s).
According to a first and preferred embodiment, at least the entire cup-shaped section, preferably even the entire diffusor, is made of the material consisting of the one or more fiber(s), i.e. the textile or the like.
According to a second embodiment, only the side wall of the cup-shaped section is made of the material consisting of the one or more fiber(s).
A third embodiment makes provision that the diffusor consists of a metal sheet with openings which is covered by the material of the one or more fiber(s).
The preferred embodiment, as already mentioned, makes provision that the entire diffusor is formed from the material consisting of the one or more fiber(s). It has been surprisingly found that such material, in particular a woven or knitted material, is sufficiently inherently stable to undertake the function of a gas bag support, for example.
Hereby, several advantages present themselves. The number of components is reduced, because no support has to be provided additionally to the external filter. At the same time, the weight and overall size of the gas bag module are reduced. A further advantage lies in that standard gas generators can be used even on occasions in which, with a small amount of available space, an additional filtering of the gas is desired.
The cup-shaped section of the diffusor can at least partially surround the gas generator and at the same time serve as a spacer for the gas generator to the wall of the gas bag.
The material, in particular the knitted mesh or woven fabric, is designed such that it acts as a particle filter for gas flowing through it, e.g. by the mesh size and the wire diameter being selected accordingly or by using several superimposed layers of knitted mesh. Here, it is particularly advantageous if the gas on its way from the gas generator to the gas bag flows through the diffusor over an as large an area as possible, because an optimum filter effect can thus be achieved.
The material, in particular the knitted mesh or woven fabric, additionally provides for a uniform distribution of the gas emerging from the gas generator. Through the design of the filter material of the cup-shaped section, the speed at which the gas flows into the gas bag can also be influenced, in order to carry out a coordinating of the restraint device.
It is, in fact, particularly advantageous if the diffusor serves as a particle filter; however, it is also possible to use a coarse-meshed knitted mesh or woven fabric with a large fiber spacing, which merely prevents the contact of the gas generator with the wall of the gas bag and, for example, serves as bearing surface and support for the gas bag in the folded state.
Preferably, the material consists of metal wire fibers.
In an advantageous embodiment of the invention, the cup-shaped section of the diffusor is designed as a deformation element. For this, an upper face of the cup-shaped section is preferably spaced apart from the gas generator, so that in the case of an impact of a vehicle occupant, a portion of the impact energy can be reduced by the deformation of the diffusor. Through the design of the knitted mesh, the energy required for the deformation can be determined in advance in relatively narrow limits, so that a flexible adaptation of the restraint device is possible.
In a preferred embodiment of the invention, the gas generator is mounted by an elastical bearing so as to be able to oscillate. In this case, the diffusor made from the fiber material serves as a so-called vibration-reducing cage which is able to absorb at least part of the oscillation energy occurring in the form of vibrations of the gas generator. As in such case a gas bag support which separates the gas generator from gas bag wall is absolutely necessary, a particularly great saving on space and weight can be achieved through the use of a diffusor of, for example, knitted mesh or woven fabric.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a diffusor of a gas bag module according to the invention;
FIG. 2 shows a diagrammatic sectional view of a gas bag module according to the invention with the diffusor of FIG. 1 ;
FIG. 3 shows a perspective view of a further embodiment of the diffusor;
FIG. 4 shows a half section through the diffusor according to FIG. 3 along line IV—IV;
FIG. 5 shows a half sectional view through a diffusor according to a third embodiment;
FIG. 6 shows a half section through the diffusor according to a fourth embodiment;
FIGS. 7 a to 7 c show detail views of various materials which are used in the gas bag module according to the invention in the cup-shaped section of the diffusor; and
FIG. 8 shows a cross-sectional view through a diffusor according to a fifth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 shows a gas bag module 10 with a gas bag 12 shown in the inflated state. A gas generator 14 is mounted on elastical bearings B so as to be able to oscillate and is connected with a vehicle-fixed part 16 , e.g. a steering wheel. The gas generator is partially surrounded by a diffusor 18 , a so-called vibration-reducing cage, which is illustrated in detail in FIG. 1 . This vibration-reducing cage has a cup-shaped section 19 with a cylindrical side wall 30 and a cover 32 . The side wall 30 , or the entire cup-shaped section consisting of side wall 30 and cover 32 , is completely made from filter material. A ring-shaped flange 21 adjoins the edge of the side wall 30 facing away from the cover 32 . The diffusor 18 is fastened to the vehicle-fixed part 16 by means of pins 20 which engage on the flange 21 . The edge of an inflow opening of the gas bag 12 is clamped between the flange of the diffusor and the vehicle-fixed part 16 . The diffusor is an element which is structurally separate from the gas generator and surrounds the latter on all sides with a defined spacing. The vertically deformed edges of the flange 21 and the cover 32 to which the filter is attached can be omitted.
The diffusor 18 is arranged between the gas generator 14 and the wall 22 of the gas bag 12 . In the folded state, the gas bag 12 lies on the upper face of the cup-shaped section 19 . The wall 22 of the gas bag 12 can therefore at no point come in direct contact with the gas generator 14 which is hot during operation. The gas generator 14 is arranged spaced apart from the diffusor 18 such that it can perform its function as a vibration damper unimpeded inside the diffusor 18 .
At least the cup-shaped section 19 of the diffusor 18 consists of a material of one or more fibers F of metal wire, examples of which are illustrated in FIGS. 7 a to 7 c . The material can be a textile, for example a woven fabric of warp- and weft threads F ( FIG. 7 a ), a knitted fabric or knitted mesh of one or more threads F ( FIG. 7 b ), or of a type of fleece ( FIG. 7 c ) consisting of irregular metal wire fibers F hooked into each other. In the embodiment according to FIG. 1 , the entire cup-shaped section 19 is of the special material of a metal wire, and gas can arrive into the interior of the gas bag 22 over the entire cup-shaped section 19 , so that the entire cup-shaped section 16 forms a filter section. The material of the metal wire is engineered such that particles are filtered out which are contained in the gas G flowing out from the gas generator 14 . No further component, such as for instance a gas bag support consisting of sheet metal, is provided between the gas generator 14 and the gas bag wall 22 . The flange 21 can likewise consist of a knitted mesh.
The material of the cup-shaped section 19 can be constructed in a single layer ( FIG. 2 ) or in several layers ( FIG. 8 ).
In addition to the function as a vibration-reducing cage and a particle filter, the diffusor 18 in the example shown here additionally serves as a deformation element, in order for example to damp the impact of the head of a vehicle occupant. The knitted mesh of the cup-shaped section 19 is deformed, as indicated by the dashed line in FIG. 2 , on impact of a body part and thus reduces the impact energy in order to protect the vehicle occupant from injury.
The diffusor 18 shown here can of course also be used together with a gas generator which is not mounted so as to be able to oscillate.
The gas generator possibly no longer has to have a filter, because this function may be fulfilled completely by the diffusor.
In the embodiment according to FIG. 3 , the flange 21 and the cover 32 are made of sheet metal. Almost the entire side wall 30 (except only a short rim on the cover 32 and on the flange 21 ) is formed by the filter section 34 , which is produced from the above-mentioned material of one or more fibers F. In the actual case according to FIG. 3 , this is a woven fabric of metal wire. The filter section is closed peripherally and represents the only bridge between the cover 32 and the flange 21 , i.e. is arranged so as to be load-bearing between these sections.
In the embodiment according to FIG. 5 , the diffusor is produced from a deep-drawn metal sheet which has numerous outflow openings 36 in the region of the side wall 30 . On the inner face, a filter section 34 is provided which covers the outflow openings 36 and therefore defines a filter section 34 in the region of the outflow openings 36 . In this embodiment, the material which defines the filter section is likewise formed from one or more fibers; in the present case, this is preferably a knitted mesh or knitted fabric.
The embodiment according to FIG. 6 corresponds substantially to the one shown in FIG. 5 , with the difference that the filter material does not lie against the side wall 30 on the inner face, but rather on the outer face.
FIG. 8 shows a further embodiment of a diffusor, which consists of several layers of woven fabric, knitted mesh and/or fleece. The entire diffusor, i.e. also the flange 21 , is made from this material.
The production of the diffusor shown in FIGS. 1 and 8 preferably takes place from a flat material which is worked by deep-drawing. | A gas bag module for a vehicle occupant restraint device comprises a gas generator and a gas bag having a wall. The module further includes a diffusor which surrounds the gas generator and has a cup-shaped section. The cup-shaped section has a filter section consisting of at least one fiber, through which filter section gas flows out from the gas generator. | 1 |
The present invention relates to a planer and in particular to debris collection containers for a planer and airflow and chip removal in a planer.
BACKGROUND OF THE INVENTION
Planers comprise a body mounted on a shoe. A rotatable cutting drum is mounted within the body which is rotatingly driven by an electric motor also mounted within the body. An aperture is formed through the shoe through which part of the periphery of the cutting drum extends. Cutting blades are mounted on the drum which, as the drum rotates, periodically pass through the aperture and below the shoe. In use, the shoe is located on a work piece and the drum is rotatingly driven by the motor. When the blades pass through the aperture and move below the shoe, the blades engage with the workpiece and remove a thin slice of the workpiece from the surface of the workpiece, producing shavings or chips. Due to the rotational movement of the drum, the shavings or chips are thrown in a generally forward and upward direction in relation to the planer. One problem is the removal of the shavings or chips from the cutting area of the planer. A second problem is the collection of the shavings or chips for disposal.
In some designs of planer, the chips or shaving are directed using a deflector which directs the shavings or chips side ways from the planer. A fan or impeller mounted on the drive shaft of the motor can be used to generate an airflow which can be used to assist in the removal of the shavings or chips. DE19512262 discloses such a system. However, the problem with existing designs are that they are not efficient at mixing the air flow with the shavings or chips to entrain them for removal.
In order to collect the chips or shavings, a debris collection container is attached to the aperture through which the chips or shavings are ejected from the body of the planer. Existing designs of debris collection containers comprise a metal wire frame which is covered by a cloth bag such as a canvas bag. A tubular connector is attached to the metal wire frame and cloth bag and which can be attached to the ejection aperture so that the chips or shavings can pass through the connector from the planer to the debris collection container. A zipper is sewn into the side of the cloth bag which, when opened forms an aperture through which the shavings or chips can be emptied from the cloth bag. A problem with this design is that the hole formed by the unopened zipper is narrow making emptying the bag difficult. Furthermore, it is difficult for an operator to insert a hand into the bag to assist in the removal of the shavings or chips. The zipper can also scratch the hand of the operator. The shavings or chips can further interfere with the operation of the zipper.
BRIEF DESCRIPTION OF THE INVENTION
Accordingly there is provided a planer comprising a body mounted on a shoe, the shoe having an aperture formed through it;
a cutting drum rotatably mounted within a recess formed by a wall within the body, a part of the periphery of the cutting drum projecting through the aperture in the shoe; a motor mounted within the body to rotatingly drive the cutting drum; at least one cutting blade mounted on the periphery of the drum capable of planing a work piece when the drum is rotating; an airflow generator which creates an air flow when the planer is in use within the body for use for entraining debris created by the cutting action of the blade to assist in the removal of the debris; directional means which directs the airflow within the body towards the area where the cutting blade cuts a work piece in order to entrain the debris in the airflow within the body for removal from the body; and a deflector for guiding the air flow and entrained debris from within the body to outside of the body wherein in use the directional means directs the airflow from the airflow generator over the top of the deflector prior to directing it forward of the cutting drum, downwards to the area where the cutting blades cuts a work piece in order to entrain any debris generated by the cutting action of the cutting blade before it is guided by the deflector to outside of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
A number of embodiments of the invention will now be described with reference to the following drawings of which:—
FIG. 1 shows a side view of the planer with the deflector removed;
FIG. 2 shows a side view of the planer of FIG. 1 with the deflector inserted;
FIG. 3 shows the design of the deflector for use in the planer;
FIG. 4 shows a lengthwise vertical cross section of the planer of FIG. 1 through the centre of the planer (excluding the motor and handle);
FIG. 5 shows a lengthwise vertical cross section taken through the planer of FIG. 1 at the position indicated by dashed line Z in FIG. 2 (excluding the handle);
FIG. 6 shows a perspective view of the first embodiment of a debris collection container;
FIG. 7 shows an exploded view of the debris collection container of FIG. 6 excluding the cloth bag and circular end piece;
FIG. 8 shows a perspective view of the debris collection container of FIG. 6 with the cap detached from the receptacle;
FIG. 9 shows a side view of the second embodiment of the debris collection container;
FIG. 10 shows a side view of the debris collection container of FIG. 9 with the cap detached;
FIG. 11 shows a sketch of the connection mechanism of the debris collection container of FIG. 9 ;
FIG. 12 shows a sketch of a top view of the planer of FIG. 1 with the debris collection container of FIG. 9 attached;
FIG. 13 shows a lengthwise vertical cross section of the second embodiment of the planer through the centre of the planer (excluding the motor and handle);
FIG. 14 shows a lengthwise vertical cross section taken through the planer of FIG. 13 (excluding the handle);
FIG. 15 shows a downward side view of the planer of FIG. 13 with the deflector inserted;
FIG. 16 shows a lengthwise vertical cross section taken through the third embodiment of the planer (excluding the handle);
FIG. 17 shows a vertical cross-section of the deflector located in a first position within the planer in accordance with the fourth embodiment of the planer; and
FIG. 18 shows a vertical cross-section of the deflector located within the planer in a second position in accordance with the fourth embodiment of the planer.
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the planer will now be described with reference to FIGS. 1 to 5 . The planer comprises a body 2 having a handle 4 attached to the top of the body 2 . A cutting drum 6 is rotatingly mounted within a recess 50 in the body 2 of the planer. The body 2 of the planer is mounted on a shoe formed from two pieces 8 , 10 . The rear part 8 is mounted rearwardly of the drum 6 . The forward part 10 is mounted forward of the drum 6 . An aperture 18 in the shoe is formed by the front 10 and rear sections of the shoe through which part of the periphery 20 of the cutting drum 6 extends. The height of the forward part 10 of the shoe can be adjusted in relation to the body 2 by the rotation of a knob 12 mounted on the front of the body 2 of the planer. The operation of the knob 12 is well known and will not therefore be discussed any further.
Mounted within a cavity 14 of the body 2 of the planer is an electric motor (not shown). The electric motor rotatingly drives the cutting drum 6 via a drive belt (not shown). Cutting blades 16 are mounted within the cutting drum 6 and which cut the workpiece upon which the planer is mounted on the cutting drum rotates. The cutting blades, as the drum rotates, periodically pass through the aperture 18 and below the shoe to cut the workpiece in well known manner. The construction of the electric motor, the cutting drum 6 , the cutting blades 16 and the belt drive system are well known in the art and are therefore not discussed any further.
Formed through the full width of the body 2 of the planer is a tubular-shaped exhaust aperture 24 . A deflector 26 which is described in more detail below can be inserted into the exhaust aperture 24 from either side. This enables the shavings or chips to be directed to either side of the planer. A plastic cap (not shown) is used to seal up the other aperture.
Referring to FIG. 3 , the deflector 26 in accordance with the present invention is shown. The deflector 26 comprises two sections 28 , 30 . The first outer section 28 is a tube of circular cross-section which, when the deflector 26 is inserted into the exhaust aperture 24 of the planer, projects from the body 2 of the planer as shown in FIG. 2 . The second section 30 is a curved section. The curved section has a substantially U-shaped cross-section which forms a trough 31 which curves over its length. The sides 32 of the U-shaped curved trough 31 have been flattened as best seen in FIGS. 4 and 5 . This results in a ridge 34 along the length of the curved section 30 where the flat surface 32 meets with a curved surface 36 of the U-shaped cross-section. The shape of the cross-section of the curved section 30 of the deflector 26 is such that it fits snugly into the exhaust aperture 24 in the side wall of the body 2 of the planer in order to hold the deflector securely and prevent it from rotating within the exhaust aperture 24 . Formed between the two sections 28 , 30 is an annular rib 38 which surrounds the circumference of the deflector 26 . The outer diameter of the annular rib 38 is greater than the diameter of the exhaust aperture 24 and thus prevents the deflector 26 from being inserted too far into the planer. When the deflector 26 is located within the body 2 of the planer, the rib 38 abuts against a side wall of the body 2 of a planer, the tubular section 28 remaining outside of the body. The rib 38 is angled as shown by axis 35 in relation to the longitudinal axis 33 of the tubular section 28 so that it is less than ninety degrees as shown in FIG. 3 . This is to allow the tubular section to point upwards when located within the body of the planer. The deflector 26 is formed as a one-piece construction and is made from plastic molded into the appropriate shape.
Mounted on the drive spindles of the motor 15 is a fan 39 (shown schematically) which generates an airflow. The air is directed into a cavity 40 formed in the body of the planer. The air then passes through a conduit 42 over the top wall 44 which forms the top wall of the exhaust aperture 24 . The direction of the airflow is indicated by the Arrows W. The airflow is then directed downwardly to an area 46 in the body 2 forward of the wall 48 of the recess 50 in which the drum 6 is mounted. An expulsion aperture 52 is formed in the wall 48 of the recess 50 forward of the cutting drum 6 through which any debris created by the cutting action of the blades 16 would be thrown by the rotating blades 16 . The airflow W is directed within the body through a port 46 A located below the expulsion aperture 52 in the wall of the recess and is directed to be blown across the aperture 52 within the body in a direction W having an acute angle to the direction of travel of any debris (shown by Arrow T) in order to entrain the debris in the airflow within the body.
The airflow and entrained debris is directed upwardly through an exhaust passage portion 42 A of the conduit 42 until it engages with the underside of the curved section 30 of the deflector 26 which is located within the exhaust aperture 24 when the planer is in use. The airflow and entrained debris is then directed out of the side of the planer through the tubular section 28 and into a debris collection container.
A second embodiment of the planer will now be described with reference to FIGS. 13 to 15 . Where the same features are shown in second embodiment as those in the first, the same reference numbers have been used. The second embodiment is exactly the same as the first embodiment except that the curved section 30 of the deflector forms the lower wall of the conduit 42 through which the airflow is directed over the deflector 26 . The aperture has no upper wall within the body 2 of the planer.
When the deflector 26 is located is located within the exhaust aperture 24 the flat side walls 32 of the deflector 26 engage with internal walls 54 of the body and form an air tight seal preventing air which is passing over the deflector 26 from travelling between the flat walls 32 of the deflector and the internal wall 54 of the body ensuring it travels forward and downward to the point 46 below the expulsion aperture 52 for entraining of the debris.
Because the deflector 26 is angled downwardly by the angle 35 of the rib 38 being non perpendicular to the longitudinal axis 33 of the deflector, a large cavity is formed above the deflector 26 allowing air to easily pass over the top of the deflector 26 . FIG. 15 shows a planer according to the second embodiment. The curve section 30 can be seen through the entrance of the exhaust aperture 24 .
A third embodiment of the planer will now be described with reference to FIG. 16 . Where the same features are shown in third embodiment as those in the first, the same reference numbers have been used. The third embodiment is exactly the same as the first embodiment except that a vent or nozzle 56 has been added within the body above the port 46 A in the body 2 forward of the wall 48 of the recess 50 in which the drum 6 is mounted. The nozzle 56 directs air into the path of the air with entrained debris at an acute angle approximately at the same height as the top of the expulsion aperture 52 formed in the wall 48 of the recess 52 forward of the cutting drum 6 through which any debris created by the cutting action of the blades 16 would be thrown by the rotating blades 16 . It will be appreciated that the nozzle 56 can be located slightly lower down relative to the aperture 52 .
A fourth embodiment of the planer will now be described with reference to figures 17 and 18 . Where the same features are shown in the fourth embodiment are the same as those shown in the first embodiment, the same reference numbers have been used. The fourth embodiment is similar to the first embodiment except that a curved pivotal flap 200 is pivotally mounted within the exhaust aperture 24 where the deflector 26 is located.
The curved pivotal flat 200 is mounted about an axis 202 which extends in a vertical plane through the centre of the width of the body 2 of the planer. The axis 202 is angled downwardly by a small amount relative to the horizontal so that the curved pivotal flap 200 pivots between an internal wall 206 of the body of the planer forming the top wall of the exhaust aperture 24 to the bottom side wall 208 of the entrance of the aperture. The curved pivotal flap 200 extends from the axis of pivot 202 to the right side 204 of the body of the planer as shown in FIGS. 17 and 18 . The curved pivotal flap 200 is capable of pivoting from a position indicated by reference letter Q through the position indicated by the reference letter R shown in dashed lines in FIG. 17 to a position indicated by reference letter S also indicated in FIG. 17 by dashed lines but shown as a solid line in FIG. 18 . A spring (now shown) biases the curved pivotal flap to the lower position indicated by reference letter Q as shown in FIG. 17 .
When the deflector 26 is not located within the planer, the curved pivotal flap 200 is biased to a downward position indicated by reference letter Q. When the flap 200 is located in this position, it forms an upper wall for right half of the exhaust aperture 24 as viewed in FIG. 17 which is aligned with the upper wall 210 of the left hand side of the exhaust aperture 24 formed by the internal structure of the body 2 of the planer to produce a continuous curved upper surface of the exhaust aperture 24 . When the curved pivotal flap is in its downward position, it completely blocks the right hand entrance 212 to the exhaust aperture 24 from the chamber 214 where the air and entrained debris pass from the drum in order to be expelled.
When the deflector 26 is inserted into the exhaust aperture 24 from the left-hand side as shown in FIG. 17 , the second section 30 of the deflector 26 is located adjacent the upper wall 210 of the left hand side of the exhaust aperture 24 formed by the internal structure of the body 2 and by the curved pivotal flap 200 on the right hand side of the exhaust aperture 24 . The insertion of the curved second section 30 of the deflector 26 causes no movement of the curved pivotal flap 200 . The shape of the curved pivotal flap 200 , both in cross-section and lengthwise, is such that it lies flush against the end part of the curved second section 30 of the deflector 26 .
When an operator tries to insert the deflector 26 from the right-hand side of the planer as shown in FIGS. 17 and 18 , the curved second section 30 of the deflector 26 is prevented from entering the exhaust aperture 24 by the curved pivotal flap 200 being located in its lower position indicated by reference letter Q due to the biasing force of the spring. In order for an operator to insert the deflector 26 into the exhaust aperture 24 , the operator pivots the curved pivotal flap 200 against biasing force of the spring from the position indicated by reference letter Q to the position indicated by reference letter S as shown in FIG. 18 . The operator can then insert the deflector 26 into the exhaust aperture 24 . When the curved second section 30 of the deflector 26 is located within the body of the planer, the curved pivotal flap 200 is sandwiched between the internal wall of the body of the planer and the second section 30 of the deflector, the shape of the curved pivotal flap 200 again being such that it lies flush against the curved second section of the deflector 26 .
A grip portion 216 is attached to the end of the curved pivotal flap 200 to enable the fingers of an operator to push the curved pivotal flap against biasing force of the spring.
The deflector 26 deflects the air and any entrained debris or chips either to the left when the deflector 26 is located from the left-hand side as shown in FIG. 17 in the direction indicated by reference letter T or to the right when the deflector 26 is located from the right-hand side of the planer as shown in FIG. 18 indicated by letter W. When the deflector is not inserted into the exhaust aperture 24 , the curved pivotal flap 200 is in its lowest position as indicated by reference letter Q, blocking the right hand entrance 212 of the aperture. As such, if the planer is operated without the deflector 26 inserted, the curved shape of the curved pivotal flap with the internal wall will direct the air and any entrained debris or chips towards the left enabling the planer to operate as if the deflector 26 was inserted into the left hand side of the body of the planer.
FIGS. 6 to 8 show a first embodiment of a debris collection container which can be used with any of the four embodiments of planer previously described. The debris collection container comprises two sections, an end cap section 60 and the receptacle 70 . The end cap section 60 is manufactured in a one-piece construction from transparent plastic. The end cap section 60 comprises a tubular connection section 62 which connects to the first tubular section 28 of the deflector 26 . The tubular connection section 62 has a circular aperture (not shown) at one end whilst the other end meets with a dome shaped section or part spherical section 64 . The dome shaped section 64 comprises a rim 66 which surrounds a large aperture formed in the base of the dome shape section 64 . The rim 66 comprises an L-shaped slot 68 which forms part of a bayonet connection system for use in connecting the end cap section 60 to the receptacle 70 . Air and entrained debris pass through the aperture in the end of the tubular connection section 62 , through the tubular connection section 62 and into the dome shape section 64 before being expelled from the end cap section 60 through the large aperture in the base of the dome 64 . The shape of the dome is such that it acts as a deflector, bending the air and entrained debris through ninety degrees so that the air and entrained debris are travelling perpendicular to the direction they were travelling in when they were passing through the tubular connection section 62 . By constructing the dome shape section 64 in transparent plastic, the operator of the planer can look into the debris collection container to determine how full container is. Furthermore, as the planer is operating, the operator will be able to see the entrained debris passing through the tubular connection section 62 and pass through the dome section thereby enabling the operator to see that the planer is working correctly.
The receptacle 70 comprises one end of an annular plastic ring 72 which surrounds a large circular aperture which forms the entrance to the receptacle 70 . The annular plastic ring 72 is divided lengthwise into two halves, a front half 74 having a diameter less than that of the diameter of the rim 66 of the dome shaped section 64 of the end cap section 60 , and a second rear half 76 having a diameter equal to that of the outer diameter of the rim of the dome shape section 64 of the end cap section 60 . A lip 78 is formed between the front and rear sections 74 , 76 which abuts against the side of the rim of the dome shaped section 64 of the end cap section 60 when the end cap section is connected to the receptacle. Two pins 80 project radially outwardly from the surface of the front half. The pins are used as part of a bayonet connection to connect the end cap section to the receptacle by sliding into the L-shaped slot 68 formed in the rim 66 of the end cap section in connecting receptacle to the end cap section 60 in well known manner.
Located at the other end of the receptacle is a circular end piece 82 formed from plastic. The circular end piece forms a base of the receptacle and can be manufactured from transparent plastic material to enable an operator to view inside the receptacle from the base. The circular end piece 82 has a diameter which is the same as that of the annular plastic ring 72 . A helical spring 84 having the same diameter as that of the annular plastic ring 72 and the circular end piece 82 connects between the annular plastic ring 72 and the circular end piece 82 and holds the relative positions of the two parts. A tubular shaped cloth bag 86 connects between the plastic annular ring 72 and the circular end piece 82 and surrounds the helical spring. The spring acts to maintain the shape of the circular receptacle and to keep the circular cloth sheaf in shape.
Formed on the annular plastic ring is a plastic catch 88 . Formed on the circular end piece is a U-shaped plastic loop 90 which extends from that the circular end piece 82 towards the annular plastic ring 72 . The location of the U-shaped plastic loop 90 results in that when that the helical spring 84 is compressed by moving the circular end piece 82 towards the annular plastic ring 72 , the loop 90 engages with and attaches to the plastic catch 88 . This is ideal for storage. During use, the U-shaped plastic loop 90 is released from the catch and allows the helical spring 84 to bias the circular end piece 82 away from the annular plastic ring 72 to maximize the volume of space within the receptacle 70 . The helical spring maintains the shape of the receptacle the relative positions of the plastic annular is ring 72 and the circular end piece 82 . However, due to the resilient nature of the helical spring 84 , the structure allows some relative movements between the two enabling flexibility within the receptacle. However, when the receptacle is not in use, the helical spring 84 can be compressed so that the circular end piece 82 is moved towards the annular plastic ring 72 until the U-shaped plastic loop 90 engages with the plastic catch 88 to secure the circular end piece 82 to the annular ring 72 maintaining the helical spring 84 under compression and substantially reducing the volume of the space within the receptacle. This is ideal for storage purposes.
In use, the tubular connection section of the end cap is connected to the deflector 26 on the planer. The receptacle 70 is connected to the end cap section by use of the bayonet connector. The circular end piece 82 is disconnected from the catch 88 on the annular plastic ring 72 to allow the helical spring 84 to bias the circular end piece 82 away from the plastic annular ring 72 generating the shape of the container.
Referring to FIGS. 9 to 11 , a second embodiment of the debris collection container is shown. The debris collection container comprises an end cap 100 and a receptacle 102 which is capable of being attached to the end cap 100 . The end cap 100 is manufactured in a one-piece construction from transparent plastic. The end cap 100 comprises a tubular connection section 104 which connects to the first outer section 28 of the deflector 26 . The tubular connection section 104 has a circular aperture at one end whilst the other end meets with a dome shaped or semi-spherical section 106 . The dome shape section 106 is mounted on a rectangular base 108 which comprises a rectangular rim 110 which surrounds a large aperture formed in the base of the dome shape section 106 . The rim 110 comprises a T-shaped slot 112 which forms part of a connection system for use in connecting the end cap 100 to the receptacle 102 . Air and entrained debris pass through the aperture in the end of the tubular connection section 104 , through the tubular connection section and into the dome shape section 106 before being expelled from the end cap 100 through the large aperture in the base 108 of the dome. The shape of the dome 106 is such that it acts as a deflector for the air and entrained debris and causes it to bend through ninety degrees so that the air and entrained debris are travelling perpendicular to the direction they were travelling in when they were passing through the tubular connection section 104 . By constructing the end cap 100 in transparent plastic, the operator of the planer can look into the debris collection container to determine how full the container is. Furthermore, as the planer is operating, the operator will be able to see the entrained debris passing through the tubular connection section and pass through the dome section thereby enabling the operator to see that the planer is working correctly.
The receptacle comprises a rectangular plastic frame 114 which acts as an entrance for the receptacle 102 . Attached to the rectangular plastic frame 114 is a large rectangular metal frame (not shown) made from stiff metal wire which forms of the structure of the receptacle. Attached to the rectangular plastic frame 114 and covering the large rectangular metal frame is a bag 116 made from cloth. The use of a cloth bag covering a metal frame is well know whether such will not be discussed any further.
Mounted within the rectangular plastic frame are two C shaped locking members 118 as shown in FIG. 11 which are used to lock the receptacle 102 tote end cap 100 . The method of mounting is not shown. The two C shaped locking members 118 are mounted within the rectangular plastic frame 114 so that the ends 120 of each of the two arms of the C shaped locking members 118 face each other as shown in FIG. 11 . Formed on the ends of the two arms of the two C shaped locking members 118 are pegs 122 which project outwardly. Helical springs 124 are mounted between the ends 120 of each pair of corresponding arms in order to bias the two C shaped locking members 118 outwardly away from each other as indicated by Arrows X. Rod 126 is mounted within the helical springs to keep the helical springs 124 in position. Holes are formed within the rectangular plastic frame to enable the fingers of an operator to engage with the two C shaped locking members to push them towards each other against the biasing force of the springs 124 .
In order to attach the receptacle 102 to the end cap 100 , an operator would squeeze the two C shaped locking members 118 together against the biasing force of the springs 124 moving the pegs 122 formed on the ends 120 of the arms 118 of each of the two C shaped locking mechanisms 118 towards each other. Whilst held in this position, the pegs 122 are able to pass through the entrance of the T-shaped slot 112 in the end cap 100 . The operator can then the push the end cap 100 towards the receptacle 102 , the pegs 122 moving further into the T-shaped slot 112 until they become aligned with the top section of the T-shaped slot 112 . The operator then releases the C shaped locking members 118 to allow them to move outwardly due to the biasing force of the springs 124 causing the pegs 122 to travel outwardly in the top section of the T-shaped slot 112 thus locking the receptacle 102 to the end cap 100 .
FIG. 12 shows a view of the second embodiment of the debris collection container attached to the planer. As can be seen, the debris collection container is located along side the planer and the longitudinal axis 132 of the debris container extends in parallel to the longitudinal axis 130 of the planer. | A planer comprising: a body; the body including a wall and the wall defining a recess; a cutting drum rotatably mounted within the recess, the cutting action of the drum creating debris and ejecting it from the recess; an airflow generator for producing an airflow; a conduit defined within the body for directing the airflow, the conduit connected to the recess for entraining and removing the debris ejected from the recess; a deflector connectable to the conduit for guiding the air flow and entrained debris from within the body to outside of the body, the deflector having an interior and exterior; and wherein the conduit directs the airflow from the airflow generator, over the exterior of the deflector, then downward to the vicinity of the recess where debris is entrained by the airflow, and then to the deflector before it is guided by the deflector to outside of the body. | 1 |
DESCRIPTION
1. Field of the Invention
The present invention relates to a power supply circuit for discharge lamps of the type comprising a power supply with inverter and a load circuit, into which the lamp is inserted, and which has an LC type resonant circuit in series with the electrodes of the lamp.
2. State of the Art
Circuits for the power supply of discharge lamps of the type mentioned above are known in the art. Examples of such circuits can be found for example in EP-A-O 610 642, EP-A-O 113 451, NL-A-9000175.
Represented in FIG. 1 is a simplified diagram of a circuit for the power supply of a discharge lamp 1.
The circuit has an inverter section, generically indicated by 1, made in a manner known per se to those skilled in the art and not described in greater detail. This typically has two electronic circuit breakers in a half-bridge arrangement which are alternately switched on and off. Upstream of the inverter is arranged a rectifier bridge (not shown) interposed between the power supply network and the inverter.
Between the lamp ζ and the inverter 1 is arranged an LC type oscillating circuit with an inductance L arranged between a first pole 3 of the inverter 1 and a first electrode 5 of the lamp ζ and with a capacitance C between the second pole 7 of the inverter 1 and the second electrode 9 of the lamp ζ. C 2 indicates a capacitor in parallel with the lamp ζ.
Upon ignition the inductance L and the capacitance C 2 in parallel with the lamp resonate such that an alternating voltage with a high peak value, of the order of 1000 V is developed between the electrodes 5 and 9. Following ignition of the lamp, a potential difference of around 100 V is developed between the electrodes 5 and 9 and resonance occurs between the inductance L and the capacitance C. Under these conditions the voltage at the point P 1 is given by the sum of an alternating voltage which oscillates between -200 and +200 V approximately, and a constant voltage of approximately +200 V, whereas at the point P2 the voltage is given by the sum of a voltage oscillating between approximately -30 V and +30 V and a constant voltage of approximately 200 V. The two waveforms of the voltage at the points P 1 and P 2 are represented diagrammatically in the two graphs on the right of FIG. 1. Specifically, therefore, the point P 1 exhibits a potential to earth which varies greatly between two positive and negative values, whereas the potential at the point P 2 oscillates slightly about a constant value. This entails a differing leakage of current to earth through the effect of the stray capacitances of the load circuit. Consequently, the current which passes through the lamp is not the same along the whole length of the latter. Since the electrode 5 undergoes a much higher voltage variation than the electrode 9 not all of the current which leaves the electrode 5 reaches the electrode 9, rather some of it leaks away through the effect of the stray capacitances. Consequently this gives a non-constant brightness of the lamp, especially noticeable in the case of a "dimmed" lamp; i.e. when the lamp is operated at a lower luminous intensity than the maximum allowed.
The effect of the leakage capacitances is even more noticeable in the case in which two lamps are placed in series in the same circuit. In this case, to avoid unacceptable variations in brightness along the extent of the two lamps, a particularly complex circuit solution of the type shown in FIG. 2 is currently resorted to. The lamps are indicated by l 1 and l 2 , whilst L 1 and L 2 indicate two inductances which resonate with the capacitance C. C 2 ' and C 2 " indicate the two capacitances in parallel with the lamps L 1 and L 2 . The power supply inverter represented diagrammatically is again indicated by 1. Essentially, when the load circuit provides for the application of two lamps, the resonant circuit is divided. In order to have the same current in both resonant circuits there is provision for the addition of a compensation transformer indicated generically by 11, whose common-core windings belong to the two resonant circuits associated with the lamps l 1 and l 2 respectively.
This circuit solution avoids the non-uniformity of brightness of the two lamps in series, but entails a high cost of the circuit, in so far as the two lamps are associated with two independent resonant circuits and furthermore the use of three magnetic components' is required, the third of which (the transformer 11) entails an appreciable increase in the overall cost of the circuit.
SUMMARY OF THE INVENTION
The purpose of the present invention is to produce a circuit for the power supply of discharge lamps which avoids the drawbacks of conventional circuits.
More particularly the purpose of the present invention is to produce a circuit for discharge lamps which makes it possible, with simple and economical structural solutions, to avoid variation in brightness along the lamp, even in the dimmed lamp condition. A further purpose of the present invention is to produce a particularly simple circuit which makes it possible to power two or more lamps in series without additional magnetic elements, with a single oscillating circuit and while eliminating the variation in brightness of the lamps in series.
These and further purposes and advantages which will become clear to those skilled in the art from reading the text which follows are obtained essentially by providing for the LC resonant circuit in series with the lamp to be a balanced resonant circuit. Balanced is understood to mean a circuit in which the values of capacitance and inductance between the lamp and the two terminals of the inverter are substantially equal.
This is obtained in particular for example by arranging an inductance and a capacitance between one pole of the inverter and the first electrode of the lamp, and a second capacitance and a second inductance between the other electrode of the lamp and the second pole of the inverter. When there are two lamps, they can be arranged in series with each other and in series with a single resonant circuit with the same configuration as described above.
In this way an oscillation in voltage between the same maximum and minimum values occurs at the two terminals of the lamp, or at the two terminals of an assemblage of two or more lamps in series. The leakage of current through the effect of the stray capacitances is therefore uniform along the entire lamp or along the lamps in series, thereby obtaining constant brightness under any operating conditions.
In a particularly advantageous configuration of the circuit according to the invention the two inductances are integrated and wound on the same core. In this way the power supply circuit contains a single magnetic component and is particularly economical and compact.
Further advantageous embodiments of the circuit according to the invention are indicated in the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by following the description and the appended drawing which shows a practical non-limiting example of the circuit according to the invention. In particular the drawing shows:
In FIGS. 1 and 2, two circuit solutions respectively with one lamp and with two lamps according to the prior art, as described above;
In FIG. 3, a power supply circuit according to the invention with two lamps in series.
DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION
In the circuit of FIG. 3 parts which are identical or which correspond to those of the above-described circuits of FIGS. 1 and 2 are indicated with the same reference numerals. More particularly, l 1 and l 2 indicate two discharge lamps in series, powered by a power supply with inverter 1, of which only a diagrammatic representation is given and the two connections of which are indicated by 3 and 7.
A capacitance C 2 is arranged in parallel with the lamps l 1 and l 2 . The electrodes of the lamp l 1 are indicated by 5 and 5' and the electrodes of the lamp l 2 are indicated by 9 and 9'.
Arranged in series with the assemblage consisting of the two lamps l 1 and l 2 and of the corresponding capacitor in parallel C 2 is a resonant circuit generically indicated by 12, which between the pole 3 of the power supply 1 and the electrode 5 of the lamp l 1 comprises a first capacitance C' in series with a first inductance L'. A second capacitance C" in series with a second inductance L" is arranged between the pole 7 and the electrode 9. The two inductances L' and L" are integrated and wound on the same winding core. The two capacitances C' and C" have substantially equal values as do also the two inductances L' and L", so that the resonant circuit 12 is perfectly balanced with respect to the load and consequently an oscillation of voltage between two substantially equal values with a consequent cancelling out of the inhomogeneity of brightness of the lamps on account of the stray capacitances occurs at the points P 1 and P 2 of the load circuit.
The same configuration can be used in a circuit for powering a single lamp ζ which in this case will be arranged between the electrodes 5 and 9, with the capacitance C 2 in parallel therewith and the balanced resonant circuit 12 between the lamp and the power supply with inverter 1.
It is to be understood that the drawing shows merely one example given solely by way of practical demonstration of the invention, it being possible for the invention to vary in its forms and arrangements without however departing from the scope of the concept which underlies the invention. The possible presence of reference numerals in the enclosed claims has the purpose of facilitating the reading of the claims with reference to the description and the drawing, and does not limit the scope of the protection represented by the claims. | The invention relates to a lamp arrangement having a resonant circuit arrangement that is balanced and has two LC series circuits each connected between a respective inverter output terminal and a lamp terminal. The two inductive elements being coupled together via a single core. | 8 |
CROSS REFERENCE TO RELATED APPLCIATIONS
[0001] This application is a continuation of U.S. application Ser. No. 09/617,793 filed Jul. 17, 2000.
[0002] This application is related to concurrently filed U.S. application (Attorney Docket 31713-164687) which is a continuation of U.S. application Ser. No. 09/617,974.
BACKGROUND OF THE INVENTION
[0003] The invention relates to a method for stacking containers that have been shaped and punched from a sheet of thermoplastic plastic in a shaping tool, and guided to stack magazines, as defined in the preamble to the main claim. The invention further relates to an apparatus for executing the method.
[0004] It is known to stack containers that have been shaped and punched from a sheet of thermoplastic plastic in stack magazines, and to remove the stacks from the stack magazines when a specific length or specific piece number is attained, then supply them to successive devices. In these successive devices, either processing takes place, such as bordering of the container edge, or the rods are packaged in foil and transferred to cartons. It is also known to shape the containers in a plurality of rows, with several containers per row, and to guide the stacks consecutively with a transfer device, so they pass through a single bordering station, for example. Stack magazines for receiving the total batch of containers shaped per cycle in the shaping tool are disposed in front of the shaping tool, which is pivoted into the transfer position.
[0005] Transporting stacks of specific lengths out of the stack magazines stipulates a certain amount of time. During this time, the shaping tool must continue producing, and the containers must be able to be stacked. German utility model application DE 298 02 318 U 1 proposes to arrange a stationary stack magazine in the stacking station, and above it, a movable stack magazine, with the movable stack magazine being displaceable in both the stacking direction and the direction transverse thereto. The containers are first transferred into the stationary stack magazine, then enter the movable stack magazine after a specified stack height has been attained.
[0006] German Patent DE-PS 26 48 563 C 2 likewise discloses transferring the containers into a stationary, lower stack magazine initially, then into a stack magazine that is adjustable in height and lifts a stack once it reaches a specific length or a specific number of containers. A lateral sliding element transfers these stacks to a horizontal receiving sheet.
[0007] Handling stacks in this manner does not provide consecutive guidance of the stacks. They would have to be taken up again, a process that would be susceptible to disturbances. A disadvantage of the two cited publications is that, during the time in which the stacks are transferred from the stack magazines, the number of stacked containers depends on the cycle number of the shaping tool. The transfer time of the stacks is constant because of the established paths and speeds of the drives. This means, however, that a varying number of containers is shaped and stacked during this transfer time. This is significant, and is associated with control problems, if stacks are to be formed from a specific number of containers. A further drawback of the two stacking methods is that the containers must be pressed over two stacking edges, which always poses a risk of deformation. As the movable stack magazine returns, it must be pushed across the standing stacks, which can also cause deformation, because each container edge of the standing containers must be guided by these retaining elements. This method of gripping containers is highly susceptible to disturbances, which may necessitate shutting down the shaping machine, cleaning the stack magazines or organizing the containers located in the stack magazines.
[0008] It is the object of the invention to execute the method in order to create stacks of a predetermined number of containers, regardless of the cycle number of the shaping tool, and independently of the time required for transferring the stacks to successive devices, even if the apparatus is shut down. The method is intended to be insusceptible to disturbances, and able to be executed even with high cycle numbers of the shaping tool. Furthermore, the method should permit the transfer of container stacks in rows to a successive device, and a fast changeover of the apparatus for a different batch of containers.
SUMMARY OF THE INVENTION
[0009] The above object generally is achieved according to a first aspect of the invention by a method for stacking containers that have been shaped and punched from a sheet of thermoplastic plastic in a shaping tool, and guided to stack magazines, and for transferring the stacks to a successive device, wherein the containers are transferred into a first stack magazine at a stacking station; after a predetermined number of containers per stack has been attained in the first stack magazine, the first stack magazine is displaced into a stack-removal station, and a second stack magazine is transferred out of the stack-removal station into the stacking station, between two cycles of the shaping tool; and while the containers are being stacked in the second stack magazine at the stacking station, the first stack magazine is emptied, and the removed stacks are guided to a successive device.
[0010] The above object generally is achieved according to a second aspect of the invention by an apparatus for stacking containers that have been ejected from a shaping tool after being shaped and punched out with, for executing the method
[0011] according to the invention wherein two stack magazines, which can be displaced between a stacking station and a
[0012] stack-removal station are provided.
[0013] The method is described in detail in conjunction with the schematic drawings of various embodiments of the apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a side view of the apparatus according to the invention.
[0015] [0015]FIG. 2 is a plan view of the apparatus according to the invention.
[0016] [0016]FIGS. 3 and 4 are views in the direction X of FIG. 2 in two phases of the method for a first embodiment of the apparatus.
[0017] [0017]FIG. 5 is a side view of a second embodiment of the apparatus according to the invention.
[0018] [0018]FIGS. 6 and 7 are a side view and plan view, respectively, of a third embodiment of the apparatus according to the invention.
[0019] [0019]FIG. 8 is a plan view of an apparatus according to a fourth embodiment of the invention.
[0020] [0020]FIGS. 9 and 10 show a variation of the invention having pivotable and possibly traveling stack magazines.
[0021] [0021]FIGS. 11 and 12 show a variation of the invention having a pallet belt.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Referring now to FIG. 1, the apparatus for executing the method of the invention is disposed downstream of a thermoforming machine, which employs a shaping tool 1 to shape and punch containers 2 from a heated sheet 3 of thermoplastic plastic. In the illustrated examples, one half of the shaping tool 1 is embodied to pivot to a horizontal position, so that the containers 2 are ejected horizontally from the shaping tool 1 by, for example, push-rods. Other directions of ejection are also feasible for the method of the invention, such as with the pivoting of the shaping tool 1 by only 75 rather than 90° from the vertical.
[0023] In an apparatus according to a first embodiment, as illustrated in FIGS. 1 through 4, a first stack magazine 4 is disposed sufficiently close to the opening of the pivoted shaping tool 1 that the containers 2 can be stacked directly in the magazine—this position is referred to as the stacking station 33 . Retaining elements retain the containers 2 in a known manner. The stack magazine 4 is adjustable in height, and can be lowered from the stacking station 33 (position A in FIG. 3) while a second stack magazine 5 is brought into position A. This movement occurs between two work cycles of the shaping tool 1 . The lowered stack magazine 4 can now be displaced horizontally by a motorized or pneumatic drive, not shown, by a distance greater than its structural width, until it reaches the position B in FIG. 3. The magazine is supported and guided by guides 6 . From this position B, the magazine is raised in stages into a stack-removal station 32 , where first the upper row of stacks 7 stops at the height of a transverse transport belt 8 having transverse supports 9 (position shown in FIG. 4). Sliding elements or push-rods 10 eject a row of stacks 7 onto the transport belt 8 . The transport belt 8 guides the stacks 7 —possibly via a further transport belt—to a site of further processing or handling. The stack magazine 4 is raised again, so the next row of stacks 7 can be ejected. With three-row stack magazines, the third stack row is cleared in the same manner.
[0024] Once the stack magazine 4 has been emptied, it is lowered and guided back into the position A. It waits there until the predetermined number of containers 2 per stack 7 has been attained in the stack magazine 5 . Then, the stack magazines 4 and 5 are exchanged between two cycles of the shaping tool 1 , with the stack magazine 5 being raised into the position D and the stack magazine 4 assuming its stacking position. The stack magazine 5 can be adjusted in height by way of a drive, and displaced horizontally by way of a second drive, until it reaches the position E (FIG. 3), thereby being guided and supported by guides 11 . From the position E, the magazine is lowered in stages, so the individual stack rows can be guided in front of the transport belt 8 and ejected.
[0025] After the stack magazine 5 has been emptied, it is transferred into the position D and kept ready for the next magazine exchange, so the exchange can be performed very quickly with a short travel path. The arrows 12 , 13 illustrate the directions of movement of the two stack magazines 4 , 5 .
[0026] This method permits all of the containers 2 to be stacked directly, without a further transfer, in stack magazines 4 , 5 , and permits counted stacks 7 to be produced simply. The apparatus can be reset simply for a different container shape through an exchange of the two stack magazines 4 , 5 and a programming of the stroke required for clearing the individual stack rows. This can be done quickly and simply. With this method, the containers are not subjected to any large movements in the free atmosphere, which could cause the growth of microorganisms on the container surface.
[0027] [0027]FIG. 5 illustrates an expansion of the stacking method, in which the containers 2 are rotated by 180° prior to stacking; that is, they are pushed bottom-first into the stack magazines 4 , 5 . This is particularly advantageous for stack formation and the further guidance of the stacks to successive devices. In this case, a turning device 14 is disposed, as a transfer device, between the tipped shaping tool 1 and the stack magazines 4 , 5 . The turning device takes up the ejected containers 2 via of a suction plate 15 , possibly having centering arbors 16 , then rotates the containers and transfers them into the stack magazines 4 , 5 , which, in this embodiment, are disposed to be displaced in the same manner—only at a distance from the shaping tool 1 .
[0028] A variation of the method that is described in conjunction with the apparatus according to FIGS. 6 and 7 permits an improved accessibility of the shaping tool 1 , e.g., for exchanging, cleaning and observing it. Also in this case, the ejected containers 2 are transferred to a transfer device in the form of a retaining or vacuum plate 15 , which can be displaced transversely on guides 16 , until it is in front of a stack magazine 17 , into which the containers 2 are transferred. This transfer is effected by a relative movement between the stack magazine 17 and the retaining plate 15 by way of a drive, not shown, which operates at the stack magazine 17 or the retaining plate 15 . This stack magazine 17 can be exchanged with a stack magazine 18 in the manner illustrated in FIG. 3. The stacks 7 are ejected in the same way, by means of an ejection device 19 , onto a transport belt 20 and possibly onto a further transport belt 21 .
[0029] In an apparatus according to FIG. 8, the method is modified such that the containers 2 are transferred alternatingly in two directions by means of two retaining plates 22 , 23 . The retaining plate 22 guides the containers 2 on one side to a stacking station 33 with the stack magazines 24 , 25 (as indicated by the dotted illustration of the plate 22 ), while the other retaining plate 23 guides them to a second stacking station 33 with the stack magazines 26 , 27 . Thus, two ejection devices 28 , 29 and two transport belts 30 , 31 are used. The stack magazines 24 , 25 and 26 , 27 are exchanged as described above.
[0030] This method offers the additional advantage that it can be used with very high cycle numbers of the shaping tool 1 if a cycle time in the order of magnitude of 1.5 seconds is insufficient to guide the containers 2 that have been taken up by the transfer device to a lateral stacking station 33 , and back in front of the shaping tool 1 .
[0031] In the examples illustrated in FIGS. 1 through 8, the stacking is effected horizontally from the shaping tool. If the process is effected at a diagonal, as shown in FIGS. 9 and 10, it can be advantageous to pivot the stack magazines 34 disposed in the stack-removal station 32 into the horizontal position, as shown in FIG. 9, before the stacks 7 are ejected, and possibly move the magazines in the stacking direction, as indicated in FIG. 10, so they lie in front of a transverse conveyor belt 35 .
[0032] [0032]FIGS. 11 and 12 illustrate a modification of the method in which, prior to stacking, the containers 2 are transferred into a circulating pallet belt 36 having pallets 37 that are provided with holes. From these pallets, the containers are transferred into the vertical stack magazines 38 , 39 , which are alternatingly guided via a pallet 37 , and thus into a stacking station 33 , beneath which an ejection device 42 is disposed. These figures illustrate, by way of example, that the stack magazines 38 , 39 are guided from the stacking station 33 to two stack-removal stations 32 , so after the stack magazines 38 , 39 have been raised and tipped in this stack-removal station 32 , the stacks 7 are guided onto two transport belts 40 , 41 . The stacks 7 can be transported out in rows by a stack-removal device 43 through a corresponding lowering of the stack magazines 38 , 39 . It is also possible in the same manner, however, to guide the two stack magazines 38 , 39 to a single stack-removal station 32 , as in the other embodiments, through a corresponding U-shaped movement of the two stack magazines 38 , 39 .
[0033] The invention now being fully described, it will be apparent to ne of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein. | A method to improve the stacking of containers comprising thermoplastic plastic, and the transfer of the stacks to a successive device. Stacks of a predetermined number are intended to be produced without disturbances, even with a high cycle number of the shaping tool. This is achieved in that the containers are stacked in a first stack magazine, which is exchanged for an adjacent stack magazine between two cycles of the shaping tool after the predetermined number has been reached. The containers are stacked in the stack magazines directly from the shaping tool, or by an intermediate transfer device. | 1 |
BACKGROUND OF THE PRIOR ART
This invention relates generally to multiple fluid pumps, and in particular to multiple fluid pumps requiring an accurate ratioing of fluids being pumped.
A number of pumping systems of the prior art used devices to detect the end of stroke of the piston.
These devices for detecting the end of the piston stroke included toggle switches, induction switches and proximity switches of various types. The primary purpose of these devices was to count the number of piston strokes and thus measure the volume of fluid pumped knowing the piston diameter and length of stroke.
All of the prior art systems were designed to pump a single fluid or slurry.
They were not interested in accurate ratioing of two or more fluids.
Those devices that were interested in ratioing of two or more fluids utilized, variously, pumps which were mechanically geared together to cause them to pump at different rates.
When pumping fluids of different viscosities, these mechanically configured pumping systems could not accurately ratio the fluids at all pumping speeds without taking into consideration special design features relative to the differences in viscosity of each fluid.
For these prior art multiple fluid pumping systems, it was extremely difficult to change the pumping ratio.
SUMMARY OF THE INVENTION
A first component pump and a second component pump are driven by separate pneumatically actuated piston and cylinder combinations, each pneumatic piston comprising a magnet attached thereto with a pair of top and bottom stroke reed switches spaced apart along the exterior of the pneumatic cylinder for detecting the respective top and bottom stroke position of the piston. The top stroke reed switches are connected in series to the top stroke coil of a two position pneumatic solenoid valve while the bottom stroke reed switches are connected in series to the bottom stroke coil of the two-position pneumatic solenoid valve. An air supply is connected to the air input side of the two-position solenoid valve. The outlet side of the solenoid valve associated with the top stroke solenoid coil is connected in fluid communication with the top end of the two pneumatic cylinders while the outlet side of the two-position solenoid valve associated with the bottom stroke solenoid coil is connected in fluid communication with bottom end of the two pneumatic cylinders. Means are provided for adjusting the length of stroke of the piston of each piston and cylinder combination.
It is, therefore, an object of the present invention to provide a multiple fluid pumping system,
It is a further object of the present invention for provide a multiple fluid pumping system in which the ratioing of the fluids is adjustable.
It is still a further object of the present invention to provide a multiple fluid pumping system in which viscosity of the fluids does not affect accuracy of ratioing or operation of the system.
It is another object of the present invention to provide a multiple fluid pump utilizing a pneumatic actuating system for the fluid pumps.
These and other objects of the present invention will become manifest upon study of the following detailed description when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of the multiple fluid pumping system of the present invention showing the general configuration and relationship of the operating elements to each other.
FIG. 2 is a cross-sectional, elevational view of the pneumatic piston and cylinder combination used to operate the positive displacement fluid pumps.
FIG. 3 is a schematic diagram of a further embodiment of the multiple fluid pumping system of the present invention showing a method for using the devices for detecting piston position as the means for regulating piston stroke length.
FIG. 4 is a cross-sectional, elevational view of a further embodiment of the present invention utilizing disposable cartridges in which pneumatically driven, disposable plungers are arranged to automatically compensate for differences in fluid viscosities and track each other along the length of the disposable cartridge.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, there is illustrated a schematic diagram of the multiple fluid pumping system of the present invention comprising, basically, a first pneumatic piston and cylinder combination 10a and a second pneumatic piston and cylinder combination 10b.
The two pneumatic piston and cylinder combinations 10a and 10b are identical. The corresponding structural elements of each pneumatic piston and cylinder combination and equipment operated thereby, are identified by the same number, however, with the letter suffix "a" or "b" depending upon whether it is first pneumatic piston and cylinder combination 10a or second piston and cylinder combination 10b. In FIG. 2, the letter suffixes "a" and "b" are not used when identifying corresponding elements of the pneumatic piston and cylinder combinations 10a and 10b of FIGS. 1 and 3.
First piston and cylinder combination 10a comprises, basically a piston rod 12a connected to piston 14a on which is attached a magnet 16a, a cylinder 18a and an adjustment screw 20a proximate the top of cylinder 18a used to adjust the end of the top of stroke of piston 14a.
Piston rod 12a of first piston and cylinder combination 10a is used to actuate positive displacement pump 30a which is in fluid communication with liquid containing reservoir 32a.
In a like manner, second piston and cylinder combination 10b actuates positive displacement pump 30b which is in fluid communication with liquid containing reservoir 32b.
The outlet port 34a of positive displacement pump 30a feeds into conduit 36a as does outlet port 34b of positive displacement pump 30b.
The two fluids coming in opposite directions in conduit 36 from pumps 30a and 30b are fed into static mixing chamber 38 there they are mixed together prior to being ejected from nozzle 40.
The system for controlling pneumatic piston and cylinder combinations 10a and 10b comprises, basically, a first top stroke reed switch 50a located proximate the top of cylinder 18a adjacent piston 14a and magnet 16a when piston 14a reaches the top of its stroke, and a bottom stroke reed switch 52a located proximate the bottom of cylinder 18a adjacent magnet 16a when piston 14a reaches the bottom of its stroke.
A similar configuration of reed switches is arranged for piston and cylinder combination 20b.
Reed switches 50a, 50b, 52a and 52b are used to control the supply of air to piston and cylinder combinations 10a and 10b.
The specific function is to prevent the piston in one of the piston and cylinder combinations from beginning its return stroke until the piston in the other piston and cylinder combination has completed its corresponding stroke.
To accomplish this function, top stroke reed switch 50a, top stroke reed switch 50b and down stroke coil 60 of two-position pneumatic solenoid valve 62 and connected in series for power supply 64. Up stroke air vent solenoid valve 68 is connected in parallel with down stroke coil 60 in order to vent air from the bottom of cylinders 18a and 18b.
In a like manner, bottom stroke reed switch 52a, bottom stroke reed switch 52b and up stroke coil 66 of two-position solenoid valve 62 are connected in series to power supply 64. Down stroke air vent solenoid valve 70 is connected in parallel wth up stroke coil 66 in order to vent air from the top of cylinders 18a and 18b.
Air is supplied to inlet port 80 of two-position pneumatic solenoid valve 62 from air supply 82.
Downstroke air is supplied to downstroke air conduit 84 from outlet port 86 of two-position pneumatic solenoid valve 62.
Upstroke air is supplied to upstroke air conduit 88 from outlet port 90 of two-position pneumatic solenoid valve 62.
Downstroke air conduit 84 fluidly communicates outlet port 86 with the top of respective cylinders 18a and 18b, while upstroke air conduit 88 fluidly communicates outlet port 90 with the bottom of respective cylinders 18a and 18b.
With reference to FIG. 2, there is illustrated as cross-sectional, elevational view of a typical pneumatic piston and cylinder combination 10a and 10b, identified in FIG. 2 merely as pneumatic piston and cylinder combination 10.
As previously described, piston and cylinder combination 10 comprises a piston rod 12 connected to piston 14 to which is attached magnet 16, all of which is enclosed in cylinder 18.
In addition, piston and cylinder combination 10 further comprises a top cap 102 hermetically sealed to the top of cylinder 18 and a bottom cap 104 hermetically sealed to the bottom of cylinder 18.
Piston stroke adjustment screw 20 is adapted to pass through and engage the center of top cap 102.
Downstroke air inlet port 106 is provided in top cap 102 and is connected to be in fluid communication with downstroke air conduit 84.
Upstroke air inlet port 108 is provided in bottom cap 104 and is connected to be in fluid communication with upstroke air conduit 88.
Piston 14 comprises a packing seal member 114 sandwiched between pressure plates 116 and 118. By tightening nut 120, pressure is applied to plates 116 and 118 and packing 114 against collar 122.
Magnet 16 is shown in FIG. 2 as an annular ring attached to pressure plate 118 in which the magnetic field is adapted to extend radially outward for detection by and actuation of reed switches 50 and 52 when adjacent their location.
Operation
To operate the multiple fluid pumping system of the present invention, air is supplied from air supply 82 to inlet port 80 of two-position pneumatic solenoid valve 62 and is directed, as shown in FIG. 1, to upstroke outlet port 90 by energizing upstroke coil 66 of pneumatic two-position solenoid valve 62.
Air pressure is thus provided to upstroke conduit 88. Upon detection of air pressure in upstroke conduit 88 by pressure switch 69, normally closed pneumatic solenoid valve 70 is actuated to the open position in order to allow air in upper part cylinders 18a and 18b to vent to the atmosphere.
Air is thus supplied by conduit 88 to inlet ports 108a and 108b proximate the bottom of pneumatic piston and cylinder combinations 10a and 10b, respectively, causing respective piston 14a and 14b to begin their up stroke. As piston 14a and 14b rise in their respective cylinders 18a and 18b, fluid from reservoirs 32a and 32b are drawn into positive displacement pumps 30a and 30b, respectively.
Since adjustment screws 20a and 20b may be set at different point to stop the upward travel of pistons 14a and 14b, and since friction forces for each piston and cylinder combination and positive displacement pump may be different, either piston 14a or 14b may arrive at its top position before the other.
For example, if piston 14b arrived at its top position prior to piston 14a, reed switch 50b would be actuated by magnet 16b to the closed position.
Since piston 14a has not yet reached its top position, magnet 16a has not yet actuated reed switch 50a, thus it remains open.
Since reed switches 50a and 50b are connected in series, no current flows to downstroke coil 60 of pneumatic two-position solenoid valve 62.
When piston 14a reaches its top position, reed switch 50a is actuated to the closed position thus completing the circuit to downstroke coil 60 of two-position pneumatic air valve 62 and switching air from upstroke outlet port 90 to downstroke outlet port 86.
Air is then supplied by downstroke air conduit 84 to the top end of cylinders 18a and 18b through inlet ports 106a and 106b, respectively, causing pistons 14a and 14b to change direction and travel downwardly driving fluids in positive displacement pumps 30a and 30b into conduit 36 to be mixed together in static mixing chamber 38 prior to ejection from nozzle 40.
In a like manner, as described when the pistons reach the top of their stroke, as pistons 14a and 14b approach the bottom of their stroke proximate reed switches 52a and 52b, respectively, should piston 14a arrive at the bottom of its stroke first and actuate reed switch 14a first, because reed switch 14b if still open, and since reed switches 52a and 52b are connected in series, no current is able to reach upstroke coil 66 of two-position pneumatic solenoid air valve 62.
The moment reed switch 52b is actuated to the closed position by magnet 16b attached to piston 14b, the circuit to coil 66 is closed and two-position pneumatic solenoid valve 62 is switched to cause air to now flow out of upstroke outlet port 90 to repeat the pumping cycle.
With reference to FIG. 3, there is illustrated a further embodiment of the present invention in which adjustment screws 20a and 20b are eliminated.
For the embodiment illustrated in FIG. 3, the top-of-stroke position or piston stroke length is controlled by the location of reed switches 50a and 50b along the outside of their respective cylinders 18a and 18b.
By thus controlling the top position of each piston, the length of stroke can be more easily adjusted to more easily adjust for different ratios of fluid volume.
The apparatus for pumping fluids from reservoirs 32a and 32b in FIG. 3 can be identical to the apparatus shown in FIG. 1 with the exception that a pair of control relays 120a and 120b are controlled by top-of-stroke reed switches 50a and 50b, respectively.
In addition, normally open solenoid valves 122a and 122b are placed in upstroke air conduit 88 proximate ports 108a and 108b, respectively, of cylinders 18a and 18b.
The purpose of normally open solenoid valves 122a and 122b is to hold either piston 14a or 14b in its top position pending arrival of the the other piston to its top position.
Control relays 120a and 120b are identical and comprise an actuating solenoid coil 126 (126a, 126b), two normally open contacts 128 (128a, 128b) and 130 (130a, 130b) and one normally closed contact 132 (132a, 132b).
Where, in FIG. 1, reed switches 50a and 50b were used to actuate solenoid coils 60 and 66, respectively, of two-position solenoid valve 62, in FIG. 3 reed switches 50a and 50b are used to actuate solenoid coils 126a and 126b of control relays 120a and 120b, respectively.
The contacts of control relays 120a and 120b are connected to control the flow of air into and out of cylinders 18a and 18b in a manner similar to that for FIG. 1.
Power supply 64 is connected in parallel to one side of reed switches 50a, 50b and 52a.
The other side of reed switch 52a is connected in series to reed switch 52b and then to upstroke coil 66 of pneumatic two-position solenoid valve 62.
Power supply 64 is also connected in parallel to one side of normally open solenoid valve 122a, one side of normally open relay contact 130a (relay 120a) and one side of normally open solenoid valve 122b.
The other side of normally open solenoid valve 122a is connected to one side of normally open relay contact 128a.
In a similar manner, the other side of normally open solenoid valve 122b is connected to one side of normally open relay contact 128b.
Normally open relay contact 128a (control relay 120a) is connected in series with normally closed relay contact 132b (control relay 120b) to ground.
In a similar manner, normally open relay contact 128b (control relay 120b) is connected in series to normally closed relay contact 132a (control relay 120) to ground.
Normally open relay contact 130a (control relay 120a) is connected in series with normally open relay contact 130b (control relay 120b) to downstroke coil 60 of pneumatic two-position solenoid valve 62.
Operation
To operate the multiple fluid pumping system of FIG. 3, air pressure is supplied to pneumatic two-position solenoid valve 62, in the position shown, providing air to outlet port 90 and air pressure to upstroke air conduit 88.
Pressure in conduit 88 actuates pressure switch 69 which in turn actuates solenoid valve 70 to vent exhaust air from the upper portion of cylinders 18a and 18b through downstroke conduit to the atmosphere.
As pistons 14a and 14b are forced upward by air entering ports 108a and 108b, reed switches 50a and 50b will remain in the the open or unactuated position.
Control relays 120a and 120b will also remain in the open or unactuated position as shown in FIG. 3.
Relay contacts 128a and 128b, which are used to control normally open solenoid valves 122a and 122b, will also remain in the open position so that air will continue to flow through normally open solenoid valves 122a and 122b into ports 108a and 108b, respectively.
As pistons 14a and 14b rise in cylinders 18a and 18b, respectively, the drag forces on each piston and positive displacement pump combination will be different due to friction as well as viscous drag forces. This will cause each piston to rise at a different rate of speed.
If, for example, piston 14a reaches the top of its stroke before piston 14b whereby reed switch 50a is actuated by magnet 16a, reed switch 50a will close causing current to flow from power supply 64 through actuating coil 126a of control relay 120a.
Upon actuation, normally open relay contacts 128a and 130a will close and normally closed relay contact 132a will open.
When relay contact 128a is closed, because it is connected in series with normally closed relay contact 132b (control relay 120b), solenoid valve 122a will be energized to the closed position entrapping the air in the lower portion of cylinder 18a thus preventing air from entering or leaving cylinder 14a through port 108a. Thus piston 14a will be held in its top-of-stroke position as determined by the location of reed switch 50a along the outside surface of cylinder 18a.
Piston 14b will continue its upward travel
With relay contact 130a closed and relay contact 130b still open, no power can be provided to downstroke coil 60 of pneumatic two-position solenoid valve 62 to alter the flow of air to piston 14b.
As soon as piston 14b reaches the top of its stroke whereby reed switch 50b is actuated to the closed position by magnet 16b, solenoid coil 126b of control relay 120b is actuated causing normally open contacts 128b and 130b to close and normally closed contact 132b to open.
In this position, normally open solenoid valve 122b would typically be energized to close and entrap air in the lower portion of cylinder 18b thus holding piston 14b at the top of its stroke.
However, since relay contact 132a (control relay 120a) is open, and relay contact 128b (control relay 120b) is connected in series with relay contact 132a, solenoid valve 122b will not be energized. In addition, since relay contact 132b (control relay 120b) is now open and is connected in series with relay contact 128a (control relay 120a) controlling solenoid valve 122a, solenoid 122a will be de-energized and be cause to open thus allowing air entrapped in the lower portion of cylinder 18a to escape to upstroke air conduit 88.
Concurrently, since both contacts 130a and 130b are now closed, downstroke coil 60 of pneumatic two-position solenoid valve 62 is energized causing air from air supply 82 to be switched to outlet port 86 to provide air pressure to downstroke conduit 84.
In a manner similar to that described for the apparatus of FIG. 1, pistons 14a and 14b are now driven downwardly to the bottom of their stroke and the pumping cycle is again repeated.
It can be seen, that by adjusting the position of reed switches 50a and 50b along the outside of their respective cylinders 18a and 18b, the upward length of piston travel and thus pumping volume can be adjusted.
Furthermore, since neither piston can begin either its upward or downward stroke before the other, any delays in piston travel due to differences in viscosity of the fluids being pumped is automatically compensated for during each piston stroke.
With respect to FIG. 4, there is illustrated a further embodiment of the present invention in which a pair of reed switches are used in conjunction with a permanent magnet to control the movements of plungers in adjacent, parallel disposed, disposable cartridges.
Each cartridge can be of a different diameter but must be of the same length.
For a two-component epoxy resin combination, the ratio of cartridge diameters determines the ratioing of the resin components.
The embodiment illustrated in FIG. 4 comprises, basically, a first disposable cartridge 202 having a necked down top opening 204 and having an open bottom end 206 adapted to receive a disposable first plunger 208, and a second disposable cartridge 212 having a necked down top opening 214 and an open bottom end 216 adapted to receive a disposable second plunger 218.
The bottom end 206 of first disposable cartridge 202 is also adapted to engage the end of first air supply plenum 220 to form an air-tight seal.
The bottom end 216 of second disposable cartridge 212 is also adapted to engage the end of second air supply plenum 222 to form an air-tight seal.
The output side 226 of first plenum solenoid valve 228 is connected in fluid communication with first plenum 220 through conduit 230, while the output side 234 of second plenum solenoid valve 236 is connected in fluid communication with second plenum 222 through conduit 238. The input side 242 of first plenum solenoid valve 228 and the input side 244 of second plenum solenoid valve 236 are connected in common and are in fluid communication with the output side 246 of main air supply solenoid valve 248, through conduit 250, whose input side 252 is in fluid communication with air supply 254 through conduit 256.
Top end or neck 204 of first disposable cartridge 202 and top end or neck 214 of second disposable cartridge 212 are connected in fluid communication and in common to static mixing chamber 260 from which the mixed fluids are ejected through nozzle 262.
In order to detect the relative positions of first plunger 208 and second plunger 218, a first reed switch 270 and a second reed switch 272 are attached to the inside of first plunger 208 and spaced apart longitudinally along plunger 208.
A permanent magnet 274 is attached to the inside of second plunger 218 in magnetic proximity to first and second reed switches 270 and 272, respectively.
First and second reed switches 270 and 272 are electrically connected in series through electrical conductor 276, with one side of first reed switch 270 electrically connected to one side of first plunger solenoid valve 228 through electrical conductor 278 and with one side of second reed switch 272 electrically connected to second plunger solenoid valve 236 through electrical conductor 280. The other side of first solenoid valve 228 and the other side of second solenoid valve 236 are connected to ground.
One side of main air solenoid valve 248 is electrically connected to the load side of normally open pushbutton. The line side of pushbutton 282 is electrically connected to the output side 284 of power supply 286.
The other side of main air solenoid valve 248 is connected to ground.
To supply electrical energy to reed switches 270 and 272, the load side of pushbutton 282 is electrically connected through conductor 288 to conductor 276 which electrically connects reed switches 270 and 272 in series.
Operation
To operate the embodiment of FIG. 4, first and second reed switches 270 and 272, respectively, are attached to the inside of first disposable plunger 208 as by self-adhesive tape or the like. In a similar manner, permanent magnet 274 is attached to the inside of second disposable plunger 218 as by self-adhesive tape or the like.
The bottom end 206 of first disposable cartridge 202 is placed in air-tight sealed relation onto first air plenum 220. In a like manner, the bottom end 216 of second disposable cartridge 212 is placed in air-tight sealed relation to second air plenum 222.
After nozzle 262 is placed in position to inject the adhesive mixture, pushbutton 282 is depressed to electrically connect main air solenoid valve 248 and first and second reed switches 270 and 272, respectively, to power supply 286.
Thus energized, main air supply solenoid valve 248 is actuated to supply pressurized air from air supply 254 to input side 242 of first plenum solenoid valve 228 and input side 244 of solenoid valve 236 through conduit 250.
While pushbutton 282 remains depressed, first reed switch 270 and second reed switch 272 will be supplied a voltage through electrical conductor 288 and series conductor 276.
If magnet 274 is located approximately equidistant between first reed switch 270 and second reed switch 272, both reed switches will be actuated thus providing electrical energy to first plenum solenoid valve 228 and second plenum solenoid valve 236 causing them to be actuated to provide air pressure to first plenum 220 and second plenum 222. The air pressure will then cause first disposable plunger 208 and second disposable plunger 218 to be pushed toward first neck 204 and second neck 214, respectively.
Because of the differences in viscosities of the fluids in each disposable container 202 and 212, the velocities of each plunger will be different whereby one plunger will tend to overtake the other plunger.
Should plunger 218 begin to overtake plunger 208, the magnetic field of magnet 274 will become less effective on second reed switch 276 as magnet 274 moves farther away. At that point, second reed switch 272 will open causing second plenum solenoid valve 236 to close thus cutting off the air supply to plenum 222 and causing plunger 218 to stop advancing any further toward neck 214.
In the meanwhile, air is still being supplied to plenum 220 permitting first plunger 208 to move further toward first neck 204 and to bring second reed switch 272 closer to permanent magnet 274. When second reed switch 272 is again activated by the magnetic field of magnet 274, air is again supplied to plenum 222 causing plunger 218 to resume its movement toward second neck 214.
In a like manner, if first plunger 208 advances toward first neck 204 faster than second plunger 218, reed switch 270 would become inactivated causing first solenoid valve 228 to close thus cutting off the air supply to first plenum 220. This would cause first plunger 208 to stop until the movement of second plunger 218 was sufficient to cause the magnetic field of magnet 274 to actuate first reed switch 270. Thus energized, first plenum solenoid valve would again provide air pressure to first plenum 220 to cause first plunger 208 to resume its movement toward first neck 204.
Thus, first plunger 208 and second plunger 218 are caused to move in unison toward their respective neck ends 204 and 214, independent of any differences in viscosity of the fluids in each disposable container or friction between the plungers and their respective disposable containers.
In some cases it may be desirable to "fine tune" the magnetic field strength of magnet 274. In such case, magnet 274 can comprise an iron core solenoid in which the DC electrical current to the solenoid can be adjusted using a variable resistance, potentiometer or the like (not shown). By "fine tuning" or adjusting the DC current in magnet 274 so that smaller movements of plungers 208 and 218 can be detected by reed switches 270 and 272, the accuracy of ratioing can be further controlled.
Although the apparatus of the present invention has been described in detail, it is intended that the scope of this invention shall not be limited by such detailed description except as provided in the claims. | A multiple fluid pumping system uses two or more fluid pumps each driven by a pneumatic piston or plunger and cylinder combination whose piston top stroke and bottom stroke positions are detected by reed switches in combination with a magnet attached to the piston. The top stroke reed switches are connected in series with one side of a two position pneumatic solenoid valve while the bottom stroke reed switches are connected in series with the other side of a two position penumatic solenoid valve. The circuit is designed to prevent one of the pistons from changing the direction of its stroke prior to the other piston reaching the end of its stroke. A further embodiment utilizes a magnet mounted on one pneumatically driven piston or plunger and a pair of reed switches mounted on the other penumatically driven piston or plunger to prevent one piston or plunger from moving faster or slover than the other piston or plunger. | 5 |
This Application is a divisional of co-pending application Ser. No. 09/500,468, filed on Feb. 9, 2000, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is in the field of propulsive machines cooperating with internal combustion, free piston engines and compressors to produce motive power, lifting, or other uses. This invention also relates to a self-actuated fuel injector that may be utilized in such an engine.
2. Background of the Invention
Numerous inventions known in the prior art have been developed, and many proposed which are based on the Newtonian principle of reactive propulsion. Propellers and helicopter rotors, jet engines, and rockets are the principal examples of that genre.
Propellers and rotors, however, require complex internal combustion or gas turbine engines to supply rotating torque to airfoil shaped blades. Large amounts of unconstrained, low pressure air is propelled aftward of the propeller/rotor due to the lift and screw action of the airfoil shaped blades, creating thrust and invoking the concomitant slip, drag, and kinetic energy air stream losses. The total fuel efficiency of these systems is determined primarily by the engine and propeller inefficiencies. In the present invention, there are no propeller losses, and engine losses and engine weight are minimized by the elimination of piston rods, crankshafts, flywheels, transmissions, and, in the case of turbines, high soak temperature turbine blading, adjunct compressors, and internal flow losses.
Chemical thermal-jet engines utilize ram air and axial flow or centrifugal compressors to force air into an engine inlet and raise its pressure in a combustion chamber. In the combustion chamber, fuel is injected and burned creating high temperature, high velocity gases. Part of the gas velocity energy is used up driving turbine blades for the compressor, and the gas then exits a nozzle to produce thrust. Large thermal losses are incurred due to the extreme temperatures at which the jet engine must operate. Rocket engines carry fuel and oxidizer internally and generate their propulsive gasses from within.
Free piston internal combustion engine and compressor combinations are well known, and the prior art contains many examples of various concepts and configurations. None were found which incorporates a power stroke at each end of a single cylinder and uses an unadorned, simple piston whose only functions are to separate the combustion and compression chambers and provide inertial energy storage. Free piston engines and compressors disclosed in the literature are complex and heavy devices which go to great lengths to counteract cylinder reaction to the acceleration of the piston(s) by the use of elaborate spring-counterweight mechanisms or tandem pistons synchronized by rack and pinions, linkages, gears, or other mechanical means.
However, there are no feasible, chambered high pressure propulsion systems that utilize unheated atmospheric air, on a continuous basis, as the main propellant medium. The reason for this is undoubtedly the difficulty of conceiving an engine and compressor combination that is simple and lightweight enough to make it practical.
SUMMARY OF THE INVENTION
The present invention involves a major change in the concept of vertical lifting and locomotion in each of the primary modes of land, air, and marine propulsion. As a necessary prerequisite to invention of the atmospheric propulsion engine, the unicycle free piston engine was invented as described herein. The combination of atmospheric air propellant and unicycle free piston engine are part of the unique and defining elements of the present invention.
The single cycle free piston engine disclosed herein uses a simple lightweight piston which minimizes the reactive movement of the cylinder assembly (this movement being a function of the ratio of piston mass-to-cylinder assembly mass).
This present invention is an atmospheric propulsion engine, firing its free piston at each end of the cylinder, scavenging of exhaust products, and natural self cooling due to the large internal ingestion of atmospheric air.
As an indication of the efficacy of the atmospheric propulsion engine, a simple calculation is presented. A cylinder 1.5 inches in diameter, and 18 inches long contains a volume of 31.8 in 2 and has a weight of air equal to 0.0014 lbs. at standard atmospheric conditions. When this mass of air is expelled at 70° F. (520° R), at sonic velocity, in 0.010 seconds through a thrust-producing nozzle, a force of 4.83 lbs. is generated. If this same mass of air is expelled at the temperature and pressure corresponding to a 10 to 1 compression ratio (1300° R and 370 psi), the force generated would be 7.71 lbs.
The atmospheric propulsion engine will produce a thrust (force) somewhere between the above numbers, and a computer simulation of the above configuration indicates that an average thrust of 6.4 lbs. can be achieved. Using aircraft type construction, it is estimated that such a device would weigh about 2.1 lbs., yielding an engine thrust-to-weight ratio of 3-to-1. Based on this evaluation, the atmospheric propulsion engine would be suitable for flying and hovering applications, as well as numerous other uses discussed in the following descriptions.
Note: The above performance calculations are based on the following formulas:
Thrust=Mass of air X Sonic velocity/time
Sonic velocity={square root over (kXgXRXT)}
Where:
k=Ratio of specific heat for air=1.4
g=Gravity constant=386.4 in./sec 2
R=Gas Constant=640 in-lb/lb-° F.
T=Temperature ° R
The specific impulse of the above configuration is calculated to be in the 2000 to 4000 lb-sec/lb range using standard automotive gasoline or diesel fuel.
A comparison of existing art with the present invention of the atmospheric propulsion engine reveals the superior characteristics of the concept and method.
This invention directly converts the fuel's thermal energy primarily into mechanical Pressure/Volume (PV) forces, compressing atmospheric air and expelling it at sonic velocity to efficiently generate thrust. The only major moving part in the atmospheric propulsion engine system is the internally shared engine/compressor piston which presents another major advantage of this invention, especially in the case of helicopters, by the elimination of noisy and dangerous external rotating propellers and rotor blades.
In the present invention, most of the fuel's thermal energy is used up in the PV expansion process of the working fluid to drive the piston, thus, after the compressed air propellant is expanded in the thrust nozzles, a relatively cool, benign gas is expelled. No compressor is required as atmospheric pressure is adequate to refill the expulsion gas chamber. However, superchargers, or in applications involving moving vehicles, ram air, can be utilized to raise the compressor inlet pressure, thus enhancing compressor volumetric efficiency and increasing the engine's thrust-to-weight ratio.
Applications for an independent, free standing thrust engine are manifest.
Given a nominal engine thrust to weight ratio of 3 to 1, coupled with the benignity of the exhaust products, it becomes feasible to design and market a personal passenger vehicle which can fly to its destination without having to concern itself with roads, bridges, or other ground based obstacles. This thrust to weight ratio also may make the engine applicable to “backpack” individual flying machines. Steering, stability and control of such flying machines can be accomplished through thrust vector control mechanisms such as movable nozzles or jet vanes as shown in FIGS. 10 and 11, or may be implemented by other well known aerodynamic means available in the existing art.
Much effort has been expended in the quest for reducing weight and increasing the efficiency of automobiles to combat air pollution. An automobile designed using the lightweight atmospheric propulsion engine disclosed herein would preclude the necessity for flywheels, crankshafts, piston rods, cooling systems, transmissions, driveshafts, differentials, and drive axles. This would eliminate the weight, power losses, and thermal inefficiencies due to these components. Probably, 50% or more of an automobile's weight could be eliminated and fuel requirements reduced considerably. In addition, the propulsion drive would make vehicle acceleration independent of tire traction. A passenger car could be designed with forward and rearward facing thruster nozzles to control acceleration and braking (thrust reversal, as shown in FIG. 6 ), and vectored nozzles could control steering to effect a vehicle which is independent of road and tire friction. Or, a hybrid of conventional braking and steering with propulsive drive could be contrived. These same characteristics apply to travel over water, snow, and ice.
Present ground effect machines (GEM) require substantial amounts of air to create sufficient pressure in the vehicle-to-surface interface plenum with which to support the gravity load and provide sufficient surface clearance. This is normally accomplished by the use of large, noisy, inefficient fans. The present invention could be used to provide partial lift from its propulsion engine(s), while using the nozzle exhaust to pressurize the GEM interface plenum. The small plenum back pressure would have little effect on the nozzle's thrust efficiency.
Aircraft propulsion would benefit from this invention's enhanced engine specific impulse and from the availability of high speed ram air to increase the propulsion chamber's volumetric efficiency, thus minimizing the size and weight of the overall propulsion system. The availability of simple, full engine thrust reversal would greatly increase aircraft braking capabilities and reduce runway rollout.
The atmospheric propulsion engine can be slidably mounted to its structure with a simple centering spring mechanism and allowed to traverse a small distance back and forth as shown in FIG. 8 . This engine can also be configured in tandem opposed end-to-end combinations to eliminate reactive engine movement, with synchronization being accomplished by a correct starting procedure, metering of fuel, and timing of the ignition process. FIG. 7 shows schematically how two tandem engines could be configured.
In addition to its use in the atmospheric propulsion engine, the simplicity and lightweight of the single cycle free piston engine disclosed herein is desirable for other engine applications such as air compressors and power tools.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a schematic cross section of the atmospheric propulsion engine of a first embodiment made up of the unicycle free piston engine and propulsion components;
FIG. 2 is the schematic of FIG. 1 with the piston in firing position at the left end of the cylinder;
FIG. 3 is the schematic of FIG. 1 with the piston crossing the inlet/exhaust ports at the left-of-center cylinder region;
FIG. 4 is the schematic of FIG. 1 with the piston crossing the nozzle port on the right end of the cylinder;
FIG. 5 is the schematic of FIG. 1 with the piston in firing position at the right end of the cylinder;
FIG. 6 is the schematic of FIG. 1 showing an engine configuration with discrete thrust reversal nozzles and valving;
FIG. 7 is a configuration of engines in tandem to eliminate reactive cylinder movements;
FIG. 8 shows a spring centered, slidably mounted engine to allow reactive movements;
FIG. 9 is a schematic of an integrated atmospheric propulsion system with fuel, compressed air, and electrical components;
FIG. 10 shows a conventional swivel nozzle concept that may be utilized in conjunction with the inventive engine;
FIG. 11 shows a conventional jet vane concept that may be utilized in conjunction with the inventive engine;
FIG. 12 is a schematic cross section of a second embodiment of the inventive engine;
FIG. 13 is the schematic of FIG. 12, with the piston in firing position at the left end of the cylinder;
FIG. 14 is the schematic of FIG. 12 with the combustion in the left combustion cylinder in progress;
FIG. 15 is the schematic of FIG. 12 with the piston at the midpoint of its stroke and at maximum velocity;
FIG. 16 is the schematic of FIG. 12 compressing the right combustion chamber;
FIG. 17 is the schematic of FIG. 12 in firing position at the right end of the cylinder;
FIG. 18 is a schematic of an inventive self-actuated fuel injector that may be utilized with the second embodiment of the inventive engine;
FIG. 19 is a schematic of the inventive self-actuated fuel injector of FIG. 18 during an injection phase of operation; and
FIG. 20 is a schematic of the inventive self-actuated fuel injector of FIG. 18 during a reset phase of operation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The first embodiment of the atmospheric propulsion engine is illustrated schematically in FIG. 1, and generally by reference numeral 1 . It is a single-cycle (unicycle), spark ignition engine and compressor having a cylinder 02 with cylinder heads 012 a and 012 b on each end and having a piston 03 slidably interposed therebetween, forming alternate combustion and compression chambers 010 a and 010 b . Cylinder heads 012 a , 012 b contain fuel injectors 08 a , 08 b and igniters 09 a , 09 b . The engine has thrust nozzles 04 a , 04 b with associated valves 06 a , 06 b and actuators 014 a , 014 b which sense piston 03 obturation of nozzle ports 011 a , 011 b to effect appropriate valve, fuel injection, and ignition timing for sustained operation as further explained below.
The engine also has common exhaust/inlet ports 07 a , 07 b which perform the dual functions of exhausting combustion gasses and admitting atmospheric air for propulsion, scavenging, and cooling. Exhaust/inlet ports 07 a , 07 b are opened and closed by valves 05 a , 05 b and-associated actuators 013 a , 013 b which sense obturation of exhaust/inlet ports 07 a and 07 b and enforce the appropriate valve action of valves 05 a , 05 b , 014 a , and 014 b.
The valves, actuators, fuel injectors, and igniters for the first embodiment are conventional elements whose description will be omitted here for the sake of brevity.
The operational cycle is defined as follows:
Referring to FIG. 2, piston 03 is positioned in cylinder 02 such that the air charge and fuel mixture in chamber 010 a is at the required combustion pressure. With piston 03 in this position, igniter 09 a is energized to initiate combustion in chamber 010 a and begin the cycle. As further shown in FIG. 2, nozzle valve 6 b is open, nozzle valve 06 a is closed, and valves 05 a , 05 b are closed at this part of the cycle and piston 03 begins accelerating to the right due to the combustion pressure in chamber 010 a (dashed line arrows indicate movement).
As piston 03 moves to the right under the impetus of the combustion pressure in chamber 010 a , the air/exhaust mixture in 010 b is compressed and expelled through nozzle port 011 b , open nozzle valve 06 b and thrust nozzle 04 b , thus generating the thrust Tb.
As shown in FIG. 3, when piston 03 crosses exhaust/inlet ports 07 a , actuator 013 a senses port 07 a closure and opens nozzle valve 06 a and causes actuator 13 a to open exhaust/inlet port 07 a via the valve 05 a . FIG. 4, shows the opened state of nozzle valve 06 a and exhaust/inlet port 07 a . At this point, piston 03 reaches its maximum velocity.
The remaining unexpanded low-pressure combustion gasses are then exhausted through exhaust/inlet port 07 a and nozzle port 011 a , nozzle valve 06 a , and thrust nozzle 04 a . Meanwhile, piston 03 continues to travel to the right in cylinder 02 due to its inertial energy. The continuing rightward movement of piston 03 , draws atmospheric air into chamber 010 a through exhaust/inlet port 07 a and nozzle 04 a . Nozzle 04 a is open at this event time to provide scavenging and dilution of the exhaust products.
The distance between nozzle port 011 b and cylinder wall 012 b is prefixed such that the mass of air charge required for subsequent combustion in chamber 010 b is attained as piston 03 crosses and obturates nozzle port 011 b as shown in FIG. 4 .
At this point, the loss of high pressure in port 011 b sensed by actuator 014 b initiates five actions, shown in FIG. 4 : the actuator 013 a for slide valve 05 a closes off exhaust/inlet ports 07 a ; the actuator 014 b closes nozzle port 011 b ; the injector 08 b injects a metered amount of fuel into chamber 010 b ; actuator 014 a for nozzle valve 06 a opens nozzle port 011 a to nozzle 04 a ; and a delayed signal is sent to fire the igniter 09 b when piston 03 achieves maximum compression in chamber 010 b as shown in FIG. 5 . The remaining inertial energy of piston 03 is dissipated in achieving the required combustion pressure in chamber 010 b.
The atmospheric propulsion engine has completed one cycle and is in position to repeat the next cycle in the opposite direction. The sequence of this next cycle can be followed by substituting the a and b components for one another and reversing the piston's direction.
FIG. 6 illustrates how the inventive engine can be utilized to generate reverse thrust. Essentially, the thrust assembly including nozzle port, valve, actuator and thrust nozzle is duplicated. Specifically, nozzle port 011 c is disposed opposite to nozzle port 011 a and has attached thereto a valve 06 c , actuator 014 c and reverse thrust nozzle 04 c . A corresponding nozzle port 011 d is disposed opposite to nozzle port 011 b and has attached thereto a valve 06 d , actuator 014 d and reverse thrust nozzle 04 d . To generate reverse thrust, valves 06 c and 06 d would be activated instead of valves 06 a and 06 b , but with the same timing relationship as for valves 06 a and 06 b described above. The result is the generation of reverse thrust Tc and Td.
FIG. 7 illustrates a tandem engine design in which two engines 1 are mounted back to back as shown. A tandem configuration joining structure 015 is utilized to affix the two engines 1 to each other in the tandem configuration. In the tandem configuration fuel injection and ignition are synchronized to eliminate reactive engine movements. This synchronization may be accomplished via conventional rack and pinions, linkages, gears, or other mechanical means. Of course, the tandem design may also include a reverse thrust arrangement like the one shown in FIG. 6 .
FIG. 8 shows a spring centered, slidably mounted engine to allow reactive movements. In other words, the atmospheric propulsion engine can be slidably mounted to a vehicle structure 018 via slidable engine mounts 016 a and 016 b and a centering spring mechanism 017 as shown in FIG. 8 . In this way, the engine 1 can traverse a small distance back and forth with slidable engine mounts 016 a , 016 b and centering spring mechanism 017 compensating for reactive forces generated by the engine 1 .
FIG. 9 is a schematic showing how the unicycle engine indicated by reference 1 can be integrated into an operating system containing adjunct fuel and electrical systems. Gas lines 019 with check valves 028 a and 028 b are picked off of cylinder 02 to pressurize high pressure gas reservoir 020 and feed the pressurized fuel tank 021 and turbine generator 023 . The fuel lines 022 feed fuel to fuel injectors 08 a and 08 b . Turbine generator 023 charges battery and electronics package 024 which transmits a timed firing signal to igniters 09 a and 09 b at the predetermined event time through electrical lines 025 . Appropriate. sensors may be utilized to sense the position of the piston via obturation of ports 07 a , 07 b , 011 a , and 011 b so that the actuators 013 a , 013 b , 014 a , 014 b as well as the fuel injectors 08 a , 08 b and igniters 09 a , 09 b can be activated at the correct timing relationship that is described above. These sensors and activators may be, for example, electrical or pneumatic.
Description of Second Embodiment
Referring to FIG. 12, the primary elements of a second embodiment of the invention which is essentially a free piston intermittent pulse rocket engine includes two combustion cylinders, 2 a and 2 b , coaxially located within, and separated by, a thrust chamber cylinder 7 . The combustion pistons 3 a , 3 b and thrust piston 4 are connected and slidably inserted into cylinders 2 a , 2 b , and 7 respectively, forming combustion chambers 5 a , 5 b and thrust chambers 6 a , 6 b . Intake check valve assemblies 20 a , 20 b provide a valved inlet for air into thrust chambers 6 a , 6 b via thrust intake ports 19 a , 19 b.
The opposing ends of combustion cylinders 2 a , 2 b are closed by cylinder heads 21 a , 21 b that contain fuel injectors 18 a , 18 b , respectively. Fuel injectors 18 a and 18 b are fed by the pressurized fuel supply line 28 . The opposing ends of thrust chambers 6 a , 6 b are closed by thrust chamber flanges 8 a , 8 b.
Injector control gas ports 16 a , 16 b are provided in cylinders 2 a , 2 b and are connected to injector gas control lines 17 a , 17 b , respectively. The other ends of injector gas control lines 17 a , 17 b are, in turn, connected to fuel injectors 18 a , 18 b . As further described below, injector control gas ports 16 a , 16 b activate fuel Injectors 18 a , 18 b as combustion pistons 3 a , 3 b cross respective injector control gas port 16 a , 16 b while moving on the compression stroke.
Exhaust ports 9 a , 9 b formed in combustion chambers 2 a , 2 b allow for expulsion and scavenging of burnt combustion gases via exhaust ducts 10 a , 10 b and exhaust thruster nozzles 11 a , 11 b . Scavenge purge lines 14 a , 14 b allow high pressure air from thrust chambers 6 b , 6 a to scavenge combustion chambers 5 a , 5 b through scavenge ports 12 a , 12 b and scavenge inlet ports 15 a , 15 b , when pistons 3 a , 3 b opens combustion chambers 5 a , 5 b to exhaust. Scavenge port check valves 13 a , 13 b prohibit counter-flow during the combustion, expansion and compression cycles of each combustion cylinder as further described below. Thrust chamber exhaust separators 24 a , 24 b ensure separation of exhaust from combustion chambers 5 a , 5 b to thrust chambers 6 a , 6 b.
Main thruster check valves 22 a , 22 b interconnect main thruster nozzles 23 a , 23 b with thruster ports 25 a , 25 b and thrust chambers 6 a , 6 b , respectively.
Pneumatic starter valves 26 a , 26 b allow compressed air from a compressed air source (not shown) to enter combustion chambers 5 a , 5 b and permit engine starting.
Operation of Second Embodiment Engine
Operation of the engine will be described here, while construction and operation of the preferred fuel injector 18 will be described in following paragraphs.
Assume that piston 3 a is in its compression position to the left of cylinder 2 a as shown in FIG. 13 . When piston 3 a is in its compression position, the volume of chamber 5 a is at its minimum, and compression pressure therein is at a maximum. Fuel injection has been accomplished and combustion is underway. Piston 3 b has opened chamber 5 b to exhaust through ports 9 b , exhaust duct 10 b and exhaust nozzle 11 b . Thrust chamber 6 a has completed expulsion of its thrust gas and its pressure is approaching atmospheric. Thrust chamber 6 b has completed its air intake stroke and is near atmospheric pressure. Injector gas control port 16 a is at atmospheric pressure through exhaust port 9 a . Check valve 13 a is closed since thrust chamber 6 b is at low intake pressure.
As the combined piston ( 3 a - 4 - 3 b ) begins moving to the right under the impetus of compression pressure and fuel combustion, the following actions occur:
Thrust chamber 6 a begins intake of air through check valve 20 a , while check valve 25 a prevents entry of air through nozzle 23 a.
Pressure builds up in thrust chamber 6 b with the subsequent expulsion of air and generation of thrust through thruster port 25 b , check valve 22 b and nozzle 23 b . Check valve 20 b prevents loss of air through the inlet port 19 b.
Piston 3 b begins closure of cylinder 2 b exhaust ports 9 b.
As shown in FIG. 14, when the combined piston ( 3 a - 4 - 3 b ) has moved right to the point where piston 3 b has closed cylinder 2 b exhaust ports 9 b , the following actions have taken place or now occur:
Piston 3 b begins compression of the combustion air in chamber 5 b.
Piston 3 a has uncovered scavenge port 12 a , but check valve 13 a prevents any flow.
Piston 3 a has uncovered injector gas control port 16 a and reset of the injector 18 a for the next cycle has begun. This will be explained in a following paragraph describing injector operation.
Expansion of combustion gas in chamber 5 a is increasing the velocity of piston 3 a - 4 - 3 b to the right.
Under the impetus of piston 4 , pressure is increasing in chamber 6 b , with the resultant increase of mass flow and thrust out of nozzle 23 b.
Chamber 6 a is ingesting atmospheric air through valve 20 a.
As shown in FIG. 15, when piston 3 a is around mid point of its stroke in cylinder 2 a , its maximum velocity is attained, and it begins to decelerate due to the pressure degradation in chamber 5 a and the opposing forces generated by the increase in pressures in chambers 6 b and 5 b.
As shown in FIG. 16, when piston 3 a crosses exhaust ports 9 a , the following events have taken place or now occur:
Chamber 5 a is vented to atmosphere through ports 9 a and exhaust nozzle 11 a, with some thrust generation.
The pressure in chamber 5 a drops below the pressure in chamber 6 b , thus allowing fresh air from chamber 6 b to enter chamber 5 a through port 15 b , line 14 a , check valve 13 a , and port 12 a . This air then scavenges chamber 5 a through exhaust ports 9 a and exhaust nozzle 11 a . Note that the scavenged air is not wasted, but used to generate thrust through exhaust nozzle 11 a.
Piston 3 b is approaching the point of maximum compression in chamber 5 b.
Piston 3 b has crossed injector gas control port 17 b and communicated it with exhaust ports 9 b and nozzle 11 b.
This begins activation of fuel injector 18 b . This function will be explained in a paragraph describing injector operation.
Chamber 6 b is reaching maximum pressure, mass flow through check valve 25 b and nozzle 23 b , and is generating maximum engine thrust output.
As shown in FIG. 17, the mass inertia of piston 3 a - 4 - 3 b then carries it to the point of maximum compression pressure in chamber 5 b , and its velocity reaches zero. At this time, the following conditions exist and the engine repeats the foregoing cycle in the opposite direction as follows:
Fuel injector 18 b is injecting fuel into combustion chamber 5 b and combustion has begun.
The pressure in thrust chamber 6 b has decayed to atmospheric and scavenging of chamber Sa is complete, while chamber 5 a remains open to exhaust and check valve 13 a ceases interflow between 6 b and 5 a.
Thrust chamber 6 a has ingested its maximum volume of air and is at near atmospheric pressure.
Starting of the engine may be accomplished via pneumatic starter valves 26 a , 26 b . Specifically, a source of compressed air may be connected to at least one of the pneumatic starter valves 26 a or 26 b . For example, compressed air may be passed through pneumatic starter valve 26 a and enter combustion chamber 5 a thereby moving the piston ( 3 a - 4 - 3 b ) to the right until the operational state shown in FIG. 17 is achieved. At this point, the fuel injector 18 b injects fuel into combustion chamber 5 b , combustion begins, and the engine starts. Alternatively, a conventional igniter can be added to at least one of the cylinder heads 21 a , 21 b and utilized as a starting means with appropriate utilization of the pneumatic starter valves to inject compressed air to move the combined piston 3 a - 4 - 3 b to a desired position, actuate a fuel injector 18 and thereby start the engine. Furthermore, pneumatic starter valves could also be added to the engine 1 of the first embodiment as an alternative method of starting that engine.
Furthermore, the system shown in FIG. 9 can be utilized with the engine of the second embodiment as indicated by the common usage of pressurized fuel line 022 .
Fuel Injector
The engine of the second embodiment is preferably equipped with the fuel injector shown in FIG. 18 . For ease of reference, fuel injectors 18 a and 18 b will be collectively referred to as fuel injector 18 it being understood that the same fuel injector 18 design is used for both 18 a and 18 b.
As shown in FIG. 18, the self-actuated, uniaxial fuel injector 18 consists of an injector body 50 into which is slidably mounted an intensifier piston 53 containing a slidably mounted fuel pintle 52 , closure spring 56 , and pintle stop 55 . All of these elements are coaxially located. An annular intensifier piston cylinder stop 54 is attached on the combustion chamber side of the injector body 50 to constrain motion of the intensifier piston 53 . On the opposite end, a fuel quantity plug and stop 51 with seal 64 is centrally located and threadably inserted into the injector body 50 .
The fuel quantity plug and stop 51 contains the pressurized fuel inlet connection 36 , fuel inlet passage 62 , and check valve 63 . The check valve 63 allows fuel to flow into the fuel cavity 65 when the cylinder pressure PI is less than the inlet fuel pressure P 4 , enabling the fuel cavity 65 to refill and reset the intensifier piston 53 when the combustion cylinder enters the exhaust phase. The threaded insertion of the fuel quantity and plug 51 into the injector body 50 allows for simple adjustment of the amount of fuel metered for each injection cycle.
When installing the fuel injector 18 , the pressurized fuel inlet connection is connected to pressurized fuel line 022 .
Operation of Fuel Injector
The fuel injector 18 accomplishes the following functions: meter the amount of fuel required for a single combustion action; contain that fuel until injection is required; multiply the fuel injection pressure by the ratio of A 1 to A 2 above the cylinder compression pressure; inject the fuel into the combustion chamber when the engine piston crosses the gas control port; reset the pintle and intensifier piston, and refill the injector for the next cycle.
Refer to FIGS. 12 and 18 and assume that injector 18 is filled with fuel (fuel cavity 65 and passages 62 and 66 ) and ready to perform the injection function. As pressure (P 1 ) rises in the cylinder chamber 5 during compression, the control gas inlet 28 (P 3 ) and chambers 58 , 60 and 61 track this pressure through gas control port 16 and injector gas control line 17 until piston 3 crosses gas control port 16 .
During this period, the annular volume and area 60 (P 3 ) is at the same pressure as the compression chamber 5 (P 1 ), thus, that portion of A 2 is counterbalanced and the effective area under P 1 is equal to A 1 . Since the top area of the slidable intensifier piston 53 in contact with the incompressible fuel in fuel cavity 65 is also equal to A 1 , the pressure in fuel cavity 65 (P 2 ) is equal to P 1 . Also, since the gas control pressure P 3 is communicated to control gas pintle cavity 61 , the areas and pressures on top and bottom of the pintle 52 being equal, this allows the pintle closing spring 56 to maintain the pintle 52 in the closed position, thus preventing fuel flow into the cylinder chamber 5 .
When the piston 3 has crossed gas control port 16 , control gas inlet 28 (P 3 ), passage 57 and chambers 58 , 60 , and 61 are vented to atmosphere through injector gas control line 17 , gas control port 16 , exhaust port 9 , and exhaust nozzle 11 . When this occurs, the effective area of the intensifier piston 53 exposed to the compression pressure P 1 is now equal to A 2 , while the effective area on the opposite end in contact with the fuel in cavity 65 (P 2 ) is still equal to A 1 . Thus, the fuel injection pressure P 2 increases in the ratio of A 2 to A 1 (P 1 ×A 2 =P 2 ×A 1 ). This pressure increase is consistent with the operation of a conventional intensifier piston.
Typically, a cylinder compression pressure P 1 of 1000 psi, might yield a fuel injection pressure P 2 of 4000 psi, but this can be tailored for any specific design by appropriately adjusting, for example, A 2 and A 1 . At the same time, the release of pressure in pintle cavity 61 allows compression pressure P 1 and the increased fuel injection pressure P 2 to act on the pintle 52 nose at injection nozzle 67 , overcoming the force of the pintle closing spring 56 and causing the pintle to snap open. Fuel is now injected into combustion chamber 5 at pressure P 2 until the fuel cavity 65 is depleted and the intensifier piston 53 contacts fuel quantity stop and plug 51 as shown in FIG. 19 . Pressure P 2 then drops to the more benign pressurized fuel inlet value P 4 , and any further fuel flow through the fuel delivery passage 66 is prevented by its inlet being in contact with the stop 51 . This state and mechanical condition of fuel injector 18 remains constant until there is a change in the gas control pressure P 3 .
As piston 3 in cylinder 2 reverses direction for its power stroke under the impetus of compression pressure and combustion, piston 3 recrosses injector gas control port 16 , again communicating control gas inlet 28 (P 3 ) with combustion pressure P 1 through injector gas control port 16 and gas control line 17 . Gas control chambers 58 , 60 , and 61 then rise pressures equal to P 1 . Pintle 52 now has equal pressures on both ends, therefore, the pintle closing spring 56 causes the pintle 52 to return to its closed position as shown in FIG. 20, expelling any residual fuel in its cavity. Intensifier piston 53 , however, has an effective area of A 1 exposed to pressure P 1 , and since P 1 is much higher than the fuel supply pressure P 4 , intensifier piston 53 will remain against stop 51 until piston 3 uncovers exhaust ports 9 , and P 1 in combustion member 5 decays to near atmospheric pressure. At this point, the fuel supply pressure P 4 is greater than the chamber 5 pressure P 1 , fuel cavity 65 refills until intensifier piston 53 reaches piston cylinder stop 54 . The fuel injector 18 is now reset, primed and ready for the next injection cycle.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | A simple propulsion engine utilizing unheated atmospheric air as the propellant, and driven by a single cycle (unicycle) engine with internal combustion cylinder and free piston is disclosed. A free piston with an annularly arranged thrust piston to divide a dual-diameter cylinder into two combustion chambers and two thrust chambers is provided. Scavenge feeder lines connected the thrust chambers to the combustion chambers via check valves provide exhaust scavenging, additional thrust output through exhaust nozzles, and feeding of fresh air into the combustion chambers. Also, pressure-actuated fuel injectors utilize pressure changes in respective combustion chambers to inject fuel at the appropriate time. The fuel injector includes an intensifier piston and pintle to raise the fuel pressure. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Japanese Patent Application No. 2005-176456, filed on Jun. 16, 2005, the contents of which are hereby incorporated by reference into the present application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a battery and a method of producing the same. The term “battery” as used in this specification is a general term for devices that utilize stored energy to supply electrical power, and refers to various secondary batteries and capacitors.
[0004] 2. Description of the Related Art
[0005] A battery having an electrode unit formed from a plurality of electrode plates and a single fixing and conducting plate is known. Usually, the plurality of electrode plates are positioned parallel with each other, leaving a gap between adjacent electrode plates such that the plurality of edges, of the plurality of electrode plates, is aligned in the same plane. The fixing and conducting plate is arranged perpendicular to the plurality of electrode plates, and makes contact with the abovementioned plurality of edges of the plurality of electrode plates aligned in the same plane. The abovementioned plurality of edges of the plurality of electrode plates aligned in the same plane are fixed to the fixing and conducting plate, whereby as a result, the plurality of electrode plates are fixed in the position parallel with each other, leaving a gap between adjacent electrode plates such that the plurality of edges of the plurality of electrode plates are aligned in the same plane. Moreover, the plurality of electrode plates is connected electrically.
[0006] At present, the electrode plates and the fixing and conducting plate perpendicular thereto are connected together by soldering. In a case where nickel (Ni) is used as a solder material, the technology for soldering-the electrode plates and the fixing and conducting plate is disclosed in Japanese unexamined patent application publication 2001-93505, for example. Specifically, a method for soldering the fixing and conducting plate to electrode plates is disclosed, wherein the electrode plate edges are coated with Ni solder material, the fixing and conducting plate is arranged perpendicular to the electrode plates, and then an energy beam is radiated onto a surface of the fixing and conducting plate on the side opposite that which contacts the electrode plates, causing the Ni solder to melt.
[0007] According to the method disclosed in Japanese unexamined patent application publication 2001-93505, when the electrode plate edges are coated with Ni solder material, variations in the thickness of the coated Ni solder material are unavoidable. If the thickness of the coated Ni solder material varies, the electrical resistance at the contacts between the fixed and conducting plate and the electrode plates will also vary.
[0008] Thus, the present invention provides an electrode unit capable of stabilizing the electrical resistance at the contacts between the electrode plates and the fixing and conducting plate that is perpendicular to the electrode plates. Additionally, the present invention provides a manufacturing method capable of stabilizing the electrical resistance at those contacts.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention proposes a battery which uses an electrode unit that ensures stability of the electrical resistance at points of contacts between electrode plates and a fixing and conducting plate that is perpendicular to the electrode plates. The present invention also proposes and a battery production method which uses the electrode unit having the stable electrical resistance at the points of contacts.
[0010] A battery of the present invention has an electrode unit in which the edges of a plurality of parallel electrode plates are fixed to a fixing and conducting plate arranged in a direction approximately perpendicular to the electrode plates. The fixing and conducting plate is used for mechanically fixing the plurality of the electrode plates and maintaining electric conductivity among the plurality of the electrode plates. At least one projection is formed on a portion of the edge of each electrode plate. In the state where the electrode plates are fixed to the fixing and conducting plate, each of the abovementioned projections is surrounded by material that forms the fixing and conducting plate. The material that surrounds each of the abovementioned projections is formed by melting and then solidifying the metal forming the fixing and conducting plate.
[0011] In the abovementioned electrode unit, the fixing and conducting plate itself is connected strongly to the projecting part of each electrode plate. The fixing and conducting plate and the electrode plates are connected together securely. Consequently, the electrical resistance is low at points of contact between the fixing and conducting plate and the electrode plate. In particular, when electrode units are mass-produced, the stable electrical resistance with low variation among points of contacts between the fixing and conducting plate and the electrode plates is extremely advantageous. As a result, high-performance batteries can be mass-produced stably. Moreover, this electrode unit does not require solder material as had been necessary in the past. A low-cost battery can be obtained, without incurring expenses for the cost of the solder material itself and for manufacturing costs associated with the application of the solder material.
[0012] Here, the term “electrode unit” refers to an integrated unit that integrates a plurality of electrode plates with a fixing and conducting plate. A “positive electrode unit” has positive electrode plates coated with positive active material, and a “negative electrode unit” has negative electrode plates coated with negative active material.
[0013] The present invention provides technical advantages when applied to at least either a positive electrode unit or a negative electrode unit, and the present invention does not necessarily require the use of both a positive electrode unit and a negative electrode unit. Of course, it is preferable that the present invention be utilized with both a positive electrode unit and a negative electrode unit.
[0014] There is no restriction to the number of electrode plates that may be used with the present invention, and this is particularly useful in the case where a large number of electrode plates is connected to a common fixing and conducting plate. In this case, the electrode unit is comprised of a plurality of electrode plates stacked so as to be parallel with each other, such that adjacent electrode plates are separated by a gap, and edges of the electrode plates are connected to a common fixing and conducting plate.
[0015] In the electrode unit of the present invention, at least one projection is formed on a portion of each of the electrode plate edges. The projections are formed at positions that overlap each other when viewed from a direction perpendicular to the plurality of electrode plates. The plurality of projections on the plurality of electrode plates are inserted into the same groove formed on the fixing and conducting plate. Each projection is surrounded at least by metal forming the fixing and conducting plate that has been melted and then solidified.
[0016] If the electrode unit has a plurality of electrode plates, a wide surface area of the active material layer can be ensured. A battery equipped with this type of electrode unit will have a high-capacity, high-power output.
[0017] Each electrode plate is preferably formed with a hole, such that the hole positions of the plurality of electrode plates overlap when viewed from a direction perpendicular to the electrode plates.
[0018] These holes can be used to align electrode plates when manufacturing a battery. By inserting an aligning rod through the holes, the holes of the electrode plates are aligned into the same position when viewed from the abovementioned direction. As a result, the edges of the electrode plates are aligned in the same plane, and the projections formed on the edges of the electrode plates are aligned into the same position when viewed from the abovementioned direction. Consequently, the projections can be inserted into a common groove formed on the fixing and conducting plate, and the area surrounding each projection can be filled uniformly with molten metal.
[0019] The abovementioned electrode unit has the significant advantage of providing stable electrical resistance at points of contacts between the fixing and conducting plate and the electrode plates. A battery comprising this electrode unit will have a high-capacity, high-power output. This electrode unit is easy to manufacture, and batteries that contain this electrode unit can be easily mass-produced.
[0020] The present invention also provides a new battery production method. A method of producing a battery of the present invention comprises the following steps, that is, positioning a plurality of electrode plates parallel with each other leaving a gap between adjacent electrode plates such that edges of the electrode plates are aligned in a plane. At least one projection is formed at a portion of the edge of each electrode plate. The method further comprises steps of fixing a fixing and conducting plate to the edges of the electrode plates such that the projections of the electrode plates are accepted within a groove formed on the fixing and conducting plate; and radiating an energy beam along the groove of the fixing and conducting plate from a side opposite the electrode plates. In this step, metal forming the fixing and conducting plate is melted at the groove, and the molten metal surrounds the projections. When the radiating step is completed and the molten metal is cooled, electrode plates are fixed to the fixing and conducting plate by their projections being surrounded by the metal that was melted and then solidified.
[0021] With this method, a battery can be obtained in which each projection of each electrode plate is connected strongly and securely to a common fixing and conducting plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is an exploded perspective view of a battery in an embodiment of the present invention.
[0023] FIG. 2 is a schematic diagram showing a general outline of a cross-section of a negative electrode plate and a negative fixing and conducting plate in the same embodiment.
[0024] FIG. 3 is an explanatory drawing showing the shape and method of formation of a groove in the negative fixing and conducting plate in the same embodiment.
[0025] FIG. 4 is a partial detail drawing showing the state when a projection of an electrode' plate is inserted into a groove of the negative fixing and conducting plate in the same embodiment.
[0026] FIG. 5 is a drawing showing the radiation path of an energy beam in the same embodiment.
[0027] FIG. 6 is a partial detail drawing showing the appearance of a projection of the electrode plate and a fixing part of the fixing and conducting plate in the same embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Preferred features to practice the present invention are described below.
[0000] (Feature 1 ) Holes are formed on electrode plate areas (lead areas) that have not been coated with active material.
(Feature 2 ) Projection has an approximate triangular shape.
(Feature 3 ) Projection has a semicircular shape.
(Feature 4 ) The present invention is widely applicably to batteries having electrode units in general. In the electrode unit, an electrode plate contacts a fixing and conducting plate that is approximately perpendicular to the electrode plate. The present invention is not limited to certain types of batteries. For example, the present invention is applicable to secondary batteries such as nickel-metal hydride secondary batteries, nickel cadmium batteries, lithium secondary batteries (lithium-ion secondary batteries), and to primary batteries such as manganese batteries and lithium batteries. A battery (such as a nickel-metal hydride secondary battery) having a stacked-type electrode body comprised of positive electrode plates and negative electrode plates stacked in alternating layers with a separator interposed therebetween is a typical example of a battery to which the present invention may be applied.
Preferred Embodiment
[0029] A general description of a battery 10 relating to this embodiment is presented with reference to FIG. 1 .
[0030] FIG. 1 is an exploded perspective view showing the configuration of a battery 10 .
[0031] FIG. 1 shows an internal structure that has been removed from a battery case 12 along lines of alternating long and short dashes, the internal structure having been separated into a negative electrode unit 40 , a positive electrode unit 20 and a separator 30 .
[0032] The battery 10 of this embodiment is comprised of a negative electrode unit 40 in which a plurality of negative electrode plates 44 are connected to a common negative fixing and conducting plate 42 , a positive electrode unit 20 in which a plurality of positive electrode plates 24 are connected to a common positive fixing and conducting plate 22 , a separator 30 arranged so as to be interposed between each negative electrode plate 44 and each positive electrode plate 24 , and a battery case 12 for housing these elements internally. The negative fixing and conducting plate 42 may also be used as a sealing plate (cover) for closing the battery case 12 .
[0033] The negative fixing and conducting plate 42 fixedly secures the plurality of negative electrode plates 44 , and electrically connects them with each other. The positive fixing and conducting plate 22 fixedly secures the plurality of positive electrode plates 24 , and electrically connects them with each other
[0034] FIG. 2 shows a cross-sectional profile of a negative electrode plate 44 and its corresponding negative fixing and conducting plate 42 of the present embodiment.
[0035] The negative electrode plate 44 is comprised of a flat plate made of nickel and formed into an approximate rectangular shape. As shown in FIGS. 1 and 2 , both faces of the negative electrode plate 44 are covered with a negative active material layer 48 containing a hydrogen-storing metal alloy powder. In the vicinity of an edge 47 of the negative electrode plate 44 , the plate material of the negative electrode plate 44 is exposed and is not covered with the negative active material layer 48 . The area in which the plate material of the negative electrode plate 44 is exposed is called a lead area 46 . The edge 47 of the negative electrode plate 44 is connected to the negative fixing and conducting plate 42 . The negative electrode plate 44 is configured such that the vertical length of the lead area 46 in FIG. 2 is shorter than the vertical length of the negative active material layer 48 . Holes 45 a and 45 b are provided in the lead area 46 . One hole 45 a is circular, and the other hole 45 b is elliptical. The negative electrode plate 44 may also be made from a nickel punching metal.
[0036] On the edge 47 that connects with the negative fixing and conducting plate 42 are formed projections 50 a , 50 b , 50 c and 50 d , having an approximate triangular shape that protrudes outward in the direction toward the negative fixing and conducting plate 42 . As shown in FIG. 1 , an external negative electrode pin 51 is formed on the upper portion of the negative fixing and conducting plate 42 . The spacing at which projections 50 a , 50 b and 50 c are formed is narrower in the vicinity of the external negative electrode pin 51 . The internal resistance of the battery 10 is decreased by concentrating, in the vicinity of the external negative electrode pin 51 , the projections 50 that are points of contacts between the negative fixing and conducting plate 42 and the negative electrode plates 44 .
[0037] The negative fixing and conducting plate 42 is perpendicular to the negative electrode plates 44 . Moreover, the edges 47 of the negative electrode plates 44 are positioned to face the negative fixing and conducting plate 42 . In other words, the plurality of edges 47 of the plurality of negative electrode plates 44 are aligned so as to be positioned in the same plane. The negative fixing and conducting plate 42 is formed from a nickel-plated steel plate. As shown in FIG. 2 , formed in the negative fixing and conducting plate 42 are a groove 52 a that accepts the projections 50 a , a groove 52 b that accepts the projections 50 b , a groove 52 c that accepts the projections 50 c , and a groove 52 d that accepts the projections 50 d . Hereafter, the collective term “projection 50 ” shall be used when describing a phenomenon common to projections 50 a , 50 b , 50 c and 50 d , and the collective term “groove 52 ” shall be used when describing a phenomenon common to grooves 52 a , 52 b , 52 c and 52 d . This rule is also applied to other members.
[0038] FIG. 3 shows the shape in the vicinity of the groove 52 of the negative fixing and conducting plate 42 . The groove 52 is formed in a curved shape, with the corners at the bottom of the groove rounded. The groove 52 is formed by placing a pressure roller at the positions indicated by arrows X and Y, and then rolling the pressure roller. The groove 52 is formed in the valley between the two ribs 53 and 54 formed by press working. The two ribs 53 and 54 that form the groove 52 are also shown in FIG. 1 .
[0039] FIG. 6 shows the state in which the negative electrode plate 44 is connected to the negative fixing and conducting plate 42 . As shown in FIG. 6 , the vicinity of the projection 50 of the negative electrode plate 44 is surrounded by metal material 62 that has been melted and then solidified, the metal material 62 being the metal material that forms the negative fixing and conducting plate 42 (nickel-plated steel plate component) or both the metal material that forms the negative fixing and conducting plate 42 and the metal material that forms the lead area 46 . Because the melted and then solidified, metal material 62 surrounds the vicinity of the projection 50 and is connected strongly to the projection 50 , the electrical resistance is low at the point of contact between the negative electrode plate 44 and the negative fixing and conducting plate 42 . Additionally, the connection between the negative electrode plate 44 and the negative fixing and conducting plate 42 has a high mechanical strength.
[0040] As shown in FIG. 1 , the positive electrode plate 24 is comprised of a flat plate made of nickel that has been formed into an approximate rectangular shape. A positive active material layer 28 containing nickel hydroxide is formed on both faces of the positive electrode plate 24 . A lead area 26 of exposed plate material is formed in the vicinity of an edge 27 of the positive electrode plate 24 that connects to the positive fixing and conducting plate 22 . The positive electrode plate 24 is configured such that vertical length of the lead area 26 is shorter than the vertical length of the active material layer 28 . Holes 25 a and 25 b are provided in the lead area 26 . One hole 25 a is circular, and the other hole 25 b is elliptical.
[0041] The positive electrode plate 24 may also utilize a configuration in which the interior of a nickel foam plate is filled with active material. In this case, the lead area 26 may adopt a configuration in which the active material of unfilled metal foam is pressurized and compressed, and a nickel lead plate is welded to one side of the lead area.
[0042] On the edge 27 of the positive electrode plate 24 are formed projections at four locations spaced apart at predetermined intervals and having an approximate triangular shape that protrudes outward in the direction toward the positive fixing and conducting plate 22 . (These projects are similar to the projections 50 on the negative electrode plates 44 , and are not shown in the drawings.) The spacing intervals are formed such that the points of contacts between the positive electrode plates 24 and the positive fixing and conducting plate 22 do not correspond to the positions of external positive electrode pins 14 , formed at two locations on the battery case 12 .
[0043] The positive fixing and conducting plate 22 is perpendicular to the positive electrode plates 24 . The edges 27 of the positive electrode plates 24 are positioned to face the positive fixing and conducting plate 22 . In other words, the plurality of edges 27 of the plurality of positive electrode plates 24 are aligned so as to be positioned in the same plane. The positive fixing and conducting plate 22 is formed from a nickel-plated steel plate. In the positive fixing and conducting plate 22 is a formed a groove that accepts the projections formed on the edges 27 of the positive electrode plates 24 , the groove being formed at a position corresponding to that of the projections. The shape of the groove and method of forming the groove are the same as for the negative electrode side, and therefore a redundant description is omitted here.
[0044] The vicinity of each projection of each positive electrode plate 24 is surrounded by a metal material that has been melted and then solidified, the metal material being the metal that forms the positive fixing and conducting plate 22 (nickel-plated steel plate component) or both the metal that forms the positive fixing and conducting plate 22 and the metal that forms the lead area 26 of the electrode plate 24 . If the metal that forms the positive fixing and conducting plate 22 surrounds the vicinity of the projection of the positive electrode plate 24 and is connected strongly to the projection, the electrical resistance will be low at the point of contact between the positive electrode plate 24 and the positive fixing and conducting plate 22 . Moreover, the mechanical strength of the connection between the positive electrode plate 24 and the positive fixing and conducting plate 22 will increase. The appearance of this connection is the same as shown in FIG. 6 .
[0045] The separator 30 is a single long sheet of porous polypropylene that has been folded back into pleats. Each electrode plate 24 and 44 is separated by being inserted between the pleats of the separator 30 . Furthermore, a porous sheet comprised of another olefin resin (such as polyethylene, for example) or a nonwoven fabric comprised of a polyamide (such as nylon, for example) may be used as the separator 30 . Moreover, the separator 30 may adopt a bag-like configuration. In this case, the separator 30 houses each electrode plate 24 and 44 internally, and separates them.
[0046] The battery case 12 of the battery 10 of the present embodiment houses a predetermined number of negative electrode plates 44 and positive electrode plates 24 that are stacked (as a layered body) in alternating layers, with the separator 30 interposed between each layer. When electrode plates 24 and 44 are housed as a layered body, an optimal gap is formed between electrode plates 24 and 44 . For example, sandwiched between two adjacent negative electrode plates 44 and 44 are a single positive electrode plate 24 and two separators 30 . As a result, a gap having a total thickness that is the sum of the thicknesses of the single positive electrode plate 24 and two separators 30 is formed between adjacent negative electrode plates 44 and 44 .
[0047] The negative active material layer 48 of the negative electrode plate 44 and the positive active material layer 28 of the positive electrode plate 24 have the same dimensions and shape, and face each other with the separator 30 interposed between each layer. The lead area 46 of the negative electrode plate 44 extends from the layered portion toward the negative fixing and conducting plate 42 , and the lead area 26 of the positive electrode plate 24 extends from the layered portion toward the positive fixing and conducting plate 22 . Holes 45 a and 45 b of the negative electrode plate 44 and holes 25 a and 25 b of the positive electrode plate 24 are located at positions on the lead area outside the layered portion.
[0048] Component elements of the battery 10 (the positive electrode unit 20 , the negative electrode unit 40 , and the separator 30 ) are housed inside the battery case 12 shaped approximately as a rectangular cuboid with an opening on one end. The external positive electrode pins 14 that connect to the positive fixing and conducting plate 22 are formed on the bottom face of the battery case 12 , when the opening is at the top. A safety valve 16 for releasing internal pressure is provided on the sidewall of the battery case 12 .
[0049] The negative fixing and conducting plate 42 is also the cover for the battery case 12 . As a result, the negative fixing and conducting plate 42 seals the opening of the battery case 12 . The external negative electrode pin 51 is formed on the external face of the negative fixing and conducting plate 42 . The battery 10 is sealed by inserting the negative fixing and conducting plate 42 into the opening of the battery, case 12 , and then connecting the edge portion of the battery case 12 to the edge portion of the negative fixing and conducting plate 42 by means of laser welding or the like. An insulating gasket or the like is used to insulate the positive fixing and conducting plate 22 and the external positive electrode pins 14 from the battery case 23 .
[0050] The electrolytic solution of the battery 10 is injected into the battery case 12 . The electrolytic solution impregnates the separator 30 and is maintained in that state. An alkaline electrolytic solution having potassium hydroxide as its main solute is used as the electrolytic solution. Further, other alkaline electrolytic solutions having alkaline components (such as sodium hydroxide, for example) as the main solute may also be used.
[0051] The method of producing the negative electrode unit 40 is described below with reference to FIGS. 2 to 6 . FIG. 4 shows the state when the projection 50 of the negative electrode plate 44 is inserted into the groove 52 of the negative fixing and conducting plate 42 .
[0052] FIG. 5 shows the radiation path 58 of an energy beam at the time when the plates are connected together. FIG. 6 shows the appearance of the metal material 62 , after having been melted by an electron beam 60 and then solidified, surrounding the vicinity of the projection 50 .
[0053] Since the positive electrode unit 20 may be manufactured in the same manner as the negative electrode unit 40 , a detailed explanation of the method of producing the positive electrode unit 20 is omitted here.
[0054] Firstly, a layered body is manufactured in which a predetermined number of negative electrode plates 44 and positive electrode plates 24 are stacked in alternating layers, with the separator 30 interposed between each layer. At this time, four aligning rods (not shown) are arranged in a parallel configuration, and then the aligning rods are inserted into the holes 25 a , 25 b , 45 a and 45 b of the respective electrode plates 24 and 44 to align the electrode plates 24 and 44 . When the aligning rods are inserted, the holes 25 a , 25 b , 45 a and 45 b become aligned in the same position when viewed, from the stacking direction. As a result, the projections 50 are aligned in the same position when viewed from the stacking direction. The holes 25 a , 25 b , 45 a and 45 b are formed on lead areas 26 and 46 . Consequently, the aligning rods for holes 25 a and 25 b do not interfere with the stacked layers of negative electrode plates 44 , and the aligning rods for holes 45 a and 45 b do not interfere with the stacked layers of positive electrode plates 24 . By inserting the aligning rods in the holes 25 a , 25 b , 45 a and 45 b , the layered body maintains an aligned state.
[0055] When the layered body is manufactured, an optimal gap is formed between electrode plates 24 and 44 . For example, sandwiched between two adjacent negative electrode plates 44 and 44 are a single positive electrode plate 24 and two separators 30 . As a result, a gap having a total thickness that is the sum of the thicknesses of the single positive electrode plate 24 and two separators 30 is formed between adjacent negative electrode plates 44 . Similarly, a gap having a total thickness that is the sum of the thicknesses, of a single negative electrode plate 44 and two separators 30 , is formed between adjacent positive electrode plates 24 .
[0056] Next, each row of projections 50 a , 50 b , 50 c and 50 c of the aligned negative electrode plates 44 is inserted into the respective grooves 52 a , 52 b , 52 c and 52 d of the negative fixing and conducting plate 42 . The aligning rods maintain the stacked state of the plurality of negative electrode' plates 44 . As a result, the task of inserting the projection 50 rows into the grooves 52 is easy to accomplish.
[0057] In this embodiment, the projection 50 of the negative electrode plate 44 is formed in an approximately triangular shape. The groove 52 of the negative fixing and conducting plate 42 is formed with a curved shape at the bottom part of the groove. When the projection 50 of the negative electrode plate 44 is inserted into the groove 52 , a space 56 is formed between the groove 52 and the projection 50 . (See FIG. 4 .)
[0058] Then, an electron beam 60 (see FIG. 6 ) is radiated from the exterior onto the negative fixing and conducting plate 42 . As a result, the projection 50 of the negative electrode plate 44 is connected to the groove 52 of the negative fixing and conducting plate 42 .
[0059] The metal material (nickel-plated steel plate component) of the negative fixing and conducting plate 42 melts when the electron beam 60 is radiated from the exterior onto the negative fixing and conducting plate 42 . As shown in FIG. 5 , the electron beam 60 radiates along a path 58 . With this type of radiation path 58 , the metal material that forms the negative fixing and conducting plate 42 melts in a strip-shape at the area forming the groove 52 . The molten metal material enters the space between the groove 52 and the projection 50 , and solidifies. The melted and then solidified metal material 62 (see FIG. 6 ) fills the area around the projection 50 . Because the metal material melts in the vicinity of the points of contact during the connection processing and then flows into the abovementioned space 56 , the contour of the negative fixing and conducting plate 42 after processing is more level than before the connection processing (see FIG. 6 ). As described above, the plurality of negative electrode plates 44 are stabilized by the aligning rods. Consequently, the task of connecting together the projection 50 and the negative fixing and conducting plate 42 is easy to implement.
[0060] As shown in FIG. 6 , when the electron beam 60 is radiated upon the negative electrode plates 44 , it melts the negative fixing and conducting plate 42 along the radiation path 58 . A surface of the projection 50 may also be melted.
[0061] The negative electrode plates 44 and the negative fixing and conducting plate 42 are connected together as described above, are joined strongly by the melted and then solidified metal material 62 . At the connection between the negative electrode plate 44 and the negative fixing and conducting plate 42 , fluctuation in mechanical connection strength is reduced. Moreover, in a battery 10 that uses this type of negative electrode unit 40 , the above-mentioned connection is highly reliable, and electrical resistance and mechanical strength are at desired levels and are stable.
[0062] After the connection processing of the negative fixing and conducting plate 42 and the negative electrode plates 44 is complete, the connection processing of the positive fixing and conducting plate 22 and the positive electrode plates 24 is implemented. Also at this time, the projections are aligned into the same position when viewed from the stacking direction, and can easily be received in the groove formed on the positive fixing and conducting plate 22 . When the electron beam is radiated onto the exterior face of the positive fixing and conducting plate 22 , the positive fixing and conducting plate 22 , or the positive fixing and conducting plate 22 and the projection surface, melt in the vicinity of the projections of the positive electrode plates 24 , and then the molten metal material solidifies to fill that area and to connect the positive fixing and conducting plate 22 to the positive electrode plates 24 . The connection process is the same as for the negative electrode unit. The connection processing itself is performed in the same manner as for the negative fixing and conducting plate 40 , and therefore a redundant description is omitted here.
[0063] The connection processing may also be implemented first for the positive electrode side, and then for the negative electrode side. Alternatively, the connection processing for the positive electrode side and for the negative electrode side may be implemented simultaneously.
[0064] After the connection processing for the positive electrode side and the connection processing for the negative electrode side are completed, the aligning rod is removed. Thus the electrode unit is produced.
[0065] Batteries of this embodiment are manufactured as follows.
[0066] The electrode unit containing the negative electrode unit 40 , the positive electrode unit 20 and the separator 30 is housed inside the battery case 12 such that the positive fixing and conducting plate 22 contacts the external positive electrode pins 14 . Then, the positive fixing and conducting plate 22 and the external positive electrode pins 14 are connected together by laser welding.
[0067] The negative fixing and conducting plate 42 also serves as a cover that seals the battery case 12 . The edge portion of the battery case 12 and the edge portion of the negative fixing and conducting plate 42 are connected together by laser welding.
[0068] Then, the electrolytic solution is injected through an electrolytic solution injection port (later becoming the safety valve 16 ) on the sidewall of the battery case 12 . The nickel-metal hydride secondary battery 10 of this embodiment is completed when the safety valve 16 is installed so as to block the injection port.
[0069] Various modifications, revisions, changes and/or improvements to the above-described embodiment are possible. Various modifications can be implemented without departing from the gist and scope of the present invention. Therefore, the apparatus and method relating to the present invention are intended to include all modifications, revisions, changes and/or improvements that are publicly known or will be developed later.
[0070] For example, the electrode plates that configure the electrode unit need only to have a projection formed at a predetermined position on the edge that connects with the fixing and conducting plate, and there are no special restrictions on other elements.
[0071] The constituent material of the electrode plates may be selected as a material traditionally used in electrode plates for the type of battery to be adopted. For example, electrode plates made of nickel are selected for the positive electrode unit in a nickel-metal hydride secondary battery, and electrode plates made of aluminum are selected for the positive electrode unit in a lithium secondary battery.
[0072] There are also no special restrictions for the shape of the projections formed on the electrode plate edge connecting to the fixing and conducting plate. Typical shapes include an approximately triangular shape, an approximately semicircular shape and an approximately trapezoidal shape. Moreover, the surface of the projections may be processed (for example, the surface may be roughened) to increase wettability with respect to the metal material of the fixing and conducting plate.
[0073] The position and number of projections formed on each electrode plate are set appropriately according to the shape and configuration of the battery.
[0074] For example, in the case of application to a package-shaped battery having an electrode unit formed by stacking a plurality of flat electrode plates made from flat plates having an approximately rectangular shape, and then connecting the edges thereof to a fixing and conducting plate, it is preferable that the projections formed on each edge are provided at a plurality of locations spaced apart by predetermined intervals. This preferred embodiment enables uneven response of the electrode at the electrode surface (electrode plate surface) to be suppressed, and power to be obtained more efficiently. Further, the spacing intervals do not have to be uniform. For example, in order to reduce the internal resistance during usage, the projections may be spaced more closely together in the vicinity of the external pins. If, due to a plurality of projections, a single electrode plate connects to a fixing and conducting plate at a plurality of locations, the status of the connection between the electrode plate and the fixing and conducting plates will improve, and the connection reliability will increase.
[0075] Additionally, it is preferable that the position and number of formed projections are the same for all electrode plates. In this case, since a row of projections is formed in the stacking direction of the electrode plates, radiation with an energy beam is easy to implement during the connection processing. Moreover, this preferred embodiment prevents variation in the connections between each projections and the fixing and conducting plate, thereby improving reliability further.
[0076] It is preferable that each electrode plate used is provided with holes for aligning (for positioning). The use of this type of electrode plate enables the electrode plates to be aligned with less positional variation by simply inserting an aligning rod through the holes while the electrode plates are in a stacked state. (In other words, the provision of these holes in advance simplifies the positioning of the electrode plates.) The combination of the holes and the aligning rod further simplify the connection processing.
[0077] The provision of two or more holes is preferable. In the case where two holes are provided, by giving one hole a circular shape and the other hole a semicircular or ellipse shape, the dimensional tolerance of the electrode plates can be absorbed and the electrode plates can be aligned stably.
[0078] The present invention is also applicable to batteries in which the electrode unit has a wound structure formed by winding one or a plurality of electrode plates, such as a cylindrical battery, for example. Even in an electrode unit having such a structure, projections for contacting with the fixing and conducting plate are formed on the edge of the lead area of the electrode plate. Although there are no special restrictions concerning the location and number of projections, it is preferable that the projections be provided at a plurality of locations and be separated by an appropriate distance. For example, when using an electrode plate configured with a row of projections extending in a radial pattern from the winding center, the present invention can be preferably implemented in the same manner as a battery having the above-described stacked electrode plates.
[0079] The fixing and conducting plate of the electrode unit should be constructed from a metal material that can be melted by an energy beam, and there are no other special restrictions on the fixing and conducting plate. For example, in the case where the present invention is applied to a nickel-metal hydride secondary battery, a ferrous metal (such as nickel-plated steel plate) used in the fixing and conducting plate of conventional nickel-metal hydride secondary batteries is used. An electron beam or the like can easily melt a fixing and conducting plate made of ferrous metal.
[0080] Because the connection between the fixing and conducting plate and the electrode plates (projections on the electrode plates) is implemented by melting with an energy beam the metal material of the fixing and conducting plate, or by melting both the metal material of the fixing and conducting plate and the metal material of the projections, the fixing and conducting plate and the electrode plates can be integrated together strongly. Moreover, the use of a metal material to configure the fixing and conducting plate enables the reliable conduction of electrical power generated by an electrode reaction.
[0081] A recessed section that accepts projections of the electrode plates is preferably located on the side surface of the fixing and conducting plate that contacts the electrode plates. The recessed section is formed to accept the electrode plate projections, one by one. For example, in the case where a plurality of electrode plates is aligned to form a row of projections, it is preferable to provide a groove capable of accepting the row of projections collectively in a group. The method of forming the groove may be selected appropriately from among conventional metal processing techniques, and a detailed description is omitted herein as the groove forming method does not characterize the present invention. Typically, the groove is formed by a press process or roll press process.
[0082] Moreover, the groove may be formed with a shape that closely adheres to the shape of the projection on the electrode plate when the projection is inserted into the groove, however a shape that leaves some space inside the groove when the projection is inserted is preferable. For example, when connecting to an electrode plate having a projection of approximately triangular shape, a fixing and conducting plate is used in which the bottom portion of the groove thereon is rounded.
[0083] Metal material of the fixing and conducting plate, having been melted by an energy beam, flows into the space inside the groove, and the molten metal solidifies to fill that space. This type of metal material connects the fixing and conducting plate to the electrode plate, and increases the connection strength of both.
[0084] The fixing and conducting plate of the present invention may also serve as a part of the battery container. For example, in the case where the battery container is comprised of a main container housing an electrode body (core part including a positive electrode plate, a negative electrode plate, and a separator) and electrolytic matter, and a sealing plate (cover) for sealing the main container, a fixing and conducting plate of either polarity may be used as the sealing plate. Moreover, if a fixing and conducting plate is formed in the shape of a container, that fixing and conducting plate itself may be used as the main container. It is possible to use a fixing and conducting plate of one polarity as the main container and a fixing and conducting plate of another polarity as the sealing plate. Moreover, in the case where open-cylinder-shaped containers are used as separate members on both ends, at least one of the ends may be sealed with one of the fixing and conducting plates.
[0085] The battery container itself does not characterize the present invention, and thus a detailed description is omitted herein.
[0086] When constructing the electrode unit, the energy beam required to connect together the electrode plate and the fixing and conducting plate should be capable of melting local areas of the object being radiated, i.e., the fixing and conducting plate, and the vicinity thereof, and conditions such as the material and thickness of the fixing and conducting plate may be selected appropriately. Examples of this type of energy beam include an electron beam, as well as various laser beams such as a YAG laser, CO 2 laser, semiconductor laser, and excimer laser.
[0087] A nickel-metal hydride secondary battery was described in the embodiment above, but the present invention is also applicable to secondary batteries such as a lithium secondary battery, and to various primary batteries, for example. Moreover, in the above-described embodiment, the present invention was applied to both a negative electrode unit formed by connecting together negative electrode plates and a negative fixing and conducting plate, and to a positive electrode unit formed by connecting together positive electrode plates and a positive fixing and conducting plate, however the present invention may also be applied only to an electrode unit of either polarity. | A battery having an electrode unit in which edges of electrode plates are mechanically and electrically connected to a fixing and conducting plate is obtained. A projection is formed at an edge of each electrode plate, and projections are inserted into a grove formed on the fixing and conducting plate. Energy beam is radiated to the fixing and conducting plate along a wall defining the groove, and metal forming the groove is melted and fills a gap between the projection and the groove. The filling metal is solidified at a condition that the melted metal surrounds the projection. The electrode plate is firmly connected to the fixing and conducting plate by a combination of the projection and the surrounding metal. The electrode plates are stably maintained at a positional relationship that the electrode plates extend parallel with each other leaving a gap between adjacent electrode plates, and the electrode plates are connected to the fixing and conducting plate with a reliable electric conductivity. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to hand tools and more particularly is directed towards a new and improved safety handle for use with Allen wrenches and similar L-shaped tools.
2. Description of the Prior Art
Allen wrenches have been in common use for a great many years and are employed in variety of assembly and repair procedures for turning Allen screws. Similar L-shaped tools may be fitted with sockets or other heads for various purposes. The wrench normally is of the same dimensions throughout and, in practice, is fabricated from a length of hexagonal cross-section stock steel rods that are bent into an L-shape. The resulting tool is somewhat slender and therefore difficult to use when applying pressure, particularly in the smaller sizes. Also, the long end of the tool tends to be somewhat short so as to provide insufficient leverage in many instances. A more serious drawback with the Allen wrench is that under excessive pressure the wrench will snap, usually at the bend. When the wrench snaps, often times pieces of metal will fly from the broken tool presenting a hazard to those in the immediate vicinity.
While various types of handles have been proposed for use with Allen wrenches, none of these has been proven to be entirely satisfactory from the standpoint of simplicity, safety, each of changing tools and the like.
Accordingly, it is an object of the present invention to provide a new and improved handle for use with Allen wrenches and similar L-shaped tools.
Another object of this invention is to provide a handle for use with Allen wrenches and the like which allows for the quick and easy exchange of Allen wrenches of different sizes.
Another object of this invention is to provide a handle for an Allen wrench or the like which substantially fully encloses the wrench during use as a protection in the event of breakage of the wrench from excessive pressure applied thereto.
SUMMARY OF THE INVENTION
This invention features a handle for use with an Allen wrench or the like, comprised of an elongated shank portion formed with an axial passage therein open to at least one end of the shank to receive the long end of an Allen wrench inserted therein. A head mounted at the one end of the shank portion is formed with a socket open to the shank passage and to one side of the head to receive the short portion of the Allen wrench and to allow the driving tip thereof to extend from the side of the head. Releasable retaining means are provided across the open end of the socket to hold the wrench in place during use thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of an Allen wrench handle made according to the inventiton,
FIG. 2 is a sectional view in side elevation thereof,
FIG. 3 is a sectional view in side elevation of a modified Allen wrench handle made according to the invention,
FIG. 4 is a view in front elevation thereof,
FIG. 5 is an end view thereof,
FIG. 6 is a perspective view thereof,
FIG. 7 is a perspective view showing a modification of the invention
FIG. 8 is a view in side elevation of the FIG. 7 device,
FIG. 9 is a detailed front view showing the head portion thereof,
FIG. 10 is an exploded perspective view showing another modification of the invention, and,
FIG. 11 is a sectional view in side elevation of the FIG. 10 device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and to FIGS. 1 and 2 in particular, the reference character 10 generally indicates a handle for use with a standard Allen wrench 12 generally comprised of an elongated shank portion 14 and a head portion 16 at one end thereof. The handle may also be used with other L-shaped hand tools. The handle may be made up in a wide variety of different sizes depending upon the sizes of Allen wrenches to be used with it. However, by way of example, when using the handle with an Allen wrench having a length of about 3" on the long leg thereof, a handle 10 with an overall length of about 5" is employed. An Allen wrench in a 3" length typically is about 3/16" in diameter and has a short driving neck about 1" long.
The shank 14 and head 16 preferably are fabricated from a high strength metal and for this purpose aluminum, steel or brass may be used to advantage. Other high strength material such as certain strong, rigid plastics may also be employed. The shank portion is formed with an axial passage 18 extending over substantially the entire length thereof and may, if desired, extend the full length thereof. The depth of the passage in any event should be sufficient to accommodate the long end of an Allen wrench inserted therein and the width should similarly be dimensioned to accommodate a wrench of that size. For a handle intended for use with a wrench of the size indicated above, the depth of the passage should be 32/3 to 4" and its width should be on the order of 1/2". Obviously, these dimensions are only by way of example and may be varied through a wide range depending upon the particular sizes of wrenches intended to be used with the handle.
The outer surface of the shank portion should provide a frictional grip and for this purpose the surface may be knurled, as illustrated, grooved or ribbed or provided with some other type of textured finish to enhance the grip thereon.
The head 16 typically is generally cylindrical in shape although other configurations may also be used. The head may be fabricated integral with the shank portion or may be a separate piece attached to the end of the shank portion by means of press fitting the same thereon or by a screw fit in which the left hand of the shank portion as viewed in FIG. 1 is threaded about its outer end while the head is formed with a tapped socket to receive the threaded end of the shank portion.
In any event the head 16 is formed with a rear wall 20 side walls 22 and 24 and a bottom wall 26 which define a socket 28 which is open at the end and at the side of the head to allow insertion and removal of an Allen wrench 12. Typically, the head 16 may be on the order of 1" in length in a handle 10 of the size described above. The head should be more or less centered on the end of the shank portion so that rear wall 20 extends from the surface of the shank portion by a sufficient distance for the head to be gripped by the fingers for initial turning of the handle when starting to turn a screw into place. For this purpose the outer cylindrical surface of the head near the back wall may be knurled as indicated at 30 in FIG. 1.
The socket 28 in the above size typically extends about one inch from the open end to the back wall of the socket and has a depth of about 2/3" from the open side to the base of the socket to define a generally U-shaped socket the bottom wall of which is flush with the inner end of the shank portion as best shown in FIG. 2. The width of the socket typically is about 1/2" which is sufficient to accommodate the short end of the Allen wrench in several sizes.
The wrench 12 is held in position by means of a latch 32 pivoted near one end thereof by a pin 34 passing through the head 16 near the back wall of the socket. The latch 32 in the illustrated embodiment is generally cylindrical and is formed with a relatively large opening 36 to receive the relatively narrow pin. It has been found that the large opening provides a good snap action for the latch when it is being opened and closed. The inner end of the latch forms into a bevelled tip 38 which bears against a leaf spring 40 at the rear of the socket. The action between the latch 32 and the leaf spring is such that the latch may be snapped into either an open or a closed position. The outer end of the latch is tapered to facilitate opening the latch as by the use of the thumb.
The leaf spring 40 is formed with a relatively narrow straight portion 42 terminating in a narrow lip 44 at its lower end which is mounted between the head and the head end of the wrench handle 10. The outer end 46 is somewhat broader than the the lower portion and is bent forwardly to apply pressure to the bevelled tip 38 to provide the snap action for the latch. With the latch open the wrench 12 may be inserted in or removed from the handle. With the wrench in place, the latch is snapped down against the end of the wrench to hold it in place.
Referring now to FIGS. 3-6, there is illustrated a modification of the invention and, in this embodiment, a wrench 12 is held in position by means of spring clip 48 which is attached to the head by means of a rivet or screw 50 along the side of the head between the back wall and the start of a socket 52. The spring clip is formed with a flat portion 54 extending from the screw 50 to the point where it forms into a reversing U-bend 56 extending into the socket 52 by a distance sufficient to engage the side of the Allen wrench 12 placed therein. The pressure is sufficient to hold the wrench in place, but, by applying a lifting pressure to the spring clip, it may be raised out of the socket and pushed to one side to allow the wrench to be removed or replaced.
With the wrench in place it is held tightly and snugly within the handle with the driving tip of the wrench extending by a distance of perhaps 1/2" from the socket 52 sufficient to engage an Allen screw or the like with which the tool is being used. The long shank portion provides increased leverage and the relatively thick shank portion provides a much firmer and fuller grip to allow more pressure to be applied when needed. Insofar the shank portion extends fully into the head portion there is almost no pressure applied to the head portion so that there is no risk of the head being displaced from the shank portion since virtually all pressure is between the shank portion of the handle and the Allen wrench. In the event that excessive pressure is applied and the wrench snaps, all of the parts will be retained within the handle with very little risk of any part flying loose therefrom. If it is desirable to turn the wrench around in order to reach a deeply located Allen screw, it is a simple matter to remove the wrench from the handle and insert the short end of the wrench in its passage 58 with the long end thereof extending out through the socket 52.
In practice, it has been found desirable to make the back wall of the head somewhat concave in order to provide a position for a thumb when using the tool. The concave cup on the head assures a firmer and a more positive grip on the handle when using the device to turn screws and the like.
Referring now to FIGS. 7, 8 and 9, there is illustrated another modification of the invention and, in this embodiment, a handle 60, generally similar to the handle 10 of the principal embodiment, is provided with different means for holding a wrench 12 in position. In the embodiment in FIGS. 7 through 9 a pair of spring loaded retainers 62 and 64 are provided across a socket 66. The retainers typically are relatively short cylindrical pieces of metal or plastic, one on either end of a C-shaped spring clip 68 extending about a head 70. The retainers 62 and 64 are seated in semi-cylindrical grooves 72 formed in the head on opposite sides of the socket with sufficient clearance to allow the retainers to spread apart by an extent sufficient to pass the wrench 12 therethrough. The wrench may be initially placed in position by passing the long end of the wrench between the retainers, causing them to spread apart, and then forcing the wrench into the handle so that the driving tip extends from the head in the manner illustrated. Once the short portion of the wrench passes into the socket and seats therein, the retainers will snap together, closing the socket along the end thereof and engaging the short portion of the wrench as best shown in FIG. 9. The tool may be readily removed by the pulling of the tip of the wrench with a force sufficient to spread the retainers apart and allow the tool to be fully withdrawn.
Referring now to FIGS. 10 and 11, there is illustrated another modification of the invention and, in this embodiment a spring-loaded keeper 74 is employed to hold a wrench 12 in a handle 76. The handle 76 and its head 78 are similar to those in the principal embodiment. However, instead of a spring clip to hold the wrench in place, the keeper 74 is utilized. The keeper 74 is hinged near the back of a head socket 80 by means of a roll pin 82. The keeper is provided with a spring 84, one end of which engages the inner end of the keeper and the other end of which engages the head with the center portion coiled about the pin. The spring normally urges the keeper into the closed position shown in full line in Fig. 11 to bear against that portion of the wrench within the socket. By raising the keeper into the open position shown in dotted line, the wrench may be removed or replaced.
While the invention has been described with particular reference to the illustrated embodiments, numerous modifications thereto will appear to those skilled in the art. | A handle is provided for use with an Allen wrench by means of which leverage and grip on the wrench is improved and protection is provided in the event that the wrench should break during use. The handle is comprised of an elongated shank portion having an axial passage therein to receive the long end of the wrench. A head is provided at the end of the shank portion and formed with a recess perpendicular to and open to the shank passage to receive the short end of the wrench. Releasable retaining means are provided to hold the end of the wrench within the handle during operation thereof. | 1 |
[0001] This application claims the benefit of U.S. Provisional Application No. 61/781,931 filed Mar. 14, 2013, the entirety of which is incorporated herein by reference.
FIELD
[0002] This disclosure relates to machines such as miter saws which include protective systems configured to rapidly stop rotational movement of a shaping device.
BACKGROUND
[0003] A number of power tools have been produced to facilitate forming a work piece into a desired shape. One such power tool is a miter saw. Miter saws present a safety concern because the saw blade of the miter saw is typically very sharp and moving at a high rate of speed. Accordingly, severe injury such as severed digits and deep lacerations can occur almost instantaneously. A number of different safety systems have been developed for miter saws in response to the dangers inherent in an exposed blade moving at high speed. One such safety system is a blade guard. Blade guards movably enclose the saw blade, thereby providing a physical barrier that must be moved before the rotating blade is exposed. While blade guards are effective to prevent some injuries, a user's finger is nonetheless in proximity to the moving blade, particularly when attempting to secure a work piece as the miter saw is used to shape the work piece.
[0004] Miter saw safety systems have been developed which are intended to stop the blade when a user's hand approaches or touches the blade. Various stopping devices have been developed including braking devices which are physically inserted into the teeth of the blade. In general, upon detection of a person in the vicinity of the blade, a signal is processed and sent to a brake mechanism to stop blade rotation within a short period of time. One such system is disclosed in U.S. Patent Publication No. 2011/0048197. In other systems, a mechanical or electrical brake is used. In all of these systems, however, the short stopping time of the blade generates a large angular momentum that will either swing the head up or down (depending on blade or motor rotation direction for miter saws) with a high force which is destructive to the structure of the tool. In addition to posing a danger to the tool, the high angular momentum forces pose an additional injury risk to the user.
[0005] What is needed therefore is a simple and reliable configuration which reduces the potential for transferring high angular momentum forces to a tool thereby causing movement of the tool.
SUMMARY
[0006] In one embodiment, an automatic braking system for a pivoting power tool includes a cutting assembly, a cutting arm supporting the cutting assembly, a hinge supporting the cutting arm through a pivot, a primary braking system operably connected to the cutting assembly, a secondary braking system operably connected to the hinge, and a safety circuit configured to sense an unsafe condition and, in response to sensing the unsafe condition, (i) control the primary braking system to oppose rotation of a blade supported by the cutting assembly, and (ii) control the secondary braking system to oppose rotation of the cutting arm.
[0007] In another embodiment, a method of operating an automatic braking system for a pivoting power tool includes supporting a cutting assembly with a cutting arm, sensing an unsafe condition using a safety circuit, controlling with the safety circuit a primary braking system to oppose rotation of a blade supported by the cutting assembly in response to sensing the unsafe condition, and controlling with the safety circuit a secondary braking system to oppose rotation of the cutting arm in response to sensing the unsafe condition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 depicts a front right perspective view of a miter saw assembly;
[0009] FIG. 2 depicts a schematic diagram of the power transfer train between the motor and the blade including a clutch and a primary braking system;
[0010] FIG. 3 depicts a simplified plan view of the right side of the power transfer train; and
[0011] FIG. 4 depicts a simplified left side plan view of a the miter saw assembly of FIG. 1 showing torque generated by activation of the primary braking system.
DESCRIPTION
[0012] For the purposes of promoting an understanding of the principles of the disclosure, 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 disclosure is thereby intended. It is further understood that the present disclosure includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the disclosure as would normally occur to one skilled in the art to which this disclosure pertains.
[0013] Referring now to FIG. 1 , there is shown a miter saw assembly 100 . The miter saw assembly 100 includes a base 102 and a turntable 104 that is rotatable on the base 102 . The miter saw assembly 100 further includes a cutting head 106 mounted on a cutting head support assembly 108 . The cutting head 106 (which may also be referred to herein as a “cutting assembly”) includes a motor 110 that is operable to rotate a circular saw blade 112 . The cutting head support assembly 108 is attached to the turntable 104 and configured to support the cutting head 106 such that the cutting head 106 may move over the turntable 104 and perform cutting operations on a work piece supported by the turntable 104 . A rip fence 114 attached to the base 102 may be used to align a work piece thereon.
[0014] The cutting head support assembly 108 includes a bevel arm 116 , a cutting arm 118 , a first pivot mechanism 120 , and a second pivot mechanism 122 . The bevel arm 116 (also referred to herein as a “bevel post”) provides a bevel support structure for the miter saw assembly 100 . The bevel arm 116 is pivotally attached to the turntable 104 by the first pivot mechanism 120 . The first pivot mechanism 120 includes a hinge arrangement that enables the bevel arm 116 of the support assembly 108 to pivot with respect to the turntable 104 during a setup procedure. In particular, this arrangement is configured to enable the bevel arm 116 to pivot from a vertical position (as shown in FIGS. 1-2 ) to an angle of 45° (not shown) or more in the leftward direction or rightward direction prior to a cutting operation. This pivoting allows the blade 112 of the cutting assembly 106 to approach the table 104 from a bevel angle and perform angled cuts on a work piece supported on the table 104 , as is well known in the art.
[0015] The cutting arm 118 of the support assembly 108 provides a support for the cutting assembly 106 . The cutting arm 118 is pivotably connected to the hinge F via the pivot F. The pivot F enables pivoting movement of the cutting assembly 106 in relation to the turntable 104 and the base 102 during a cutting operation. This pivoting allows the blade 112 of the cutting assembly 106 to move toward and away from the horizontal turntable 104 to perform a cutting operation. In other embodiments, the cutting arm 118 , may be mounted to the hinge F component and the hinge F component is mounted on rails (slide miter saws). Another configuration is for the cutting arm 118 to be mounted on directly on bevel arm 116 with pivot at second pivot 122 (chop saw—non sliding or gliding miter saws).
[0016] The cutting assembly 106 includes a handle 126 connected to the cutting arm 118 to facilitate movement of the cutting assembly 106 in relation to the turntable 104 . The handle 126 is designed and dimensioned to be grasped by a human hand when performing a cutting operation. This allows the user to easily pivot the cutting assembly 106 . A switch (not shown) may be provided on the handle 126 to allow the user to easily energize and de-energize the electric motor 110 during a cutting operation. A blade guard 128 covers the top portion of the circular saw blade 112 . A lower blade guard 124 , shown in shadow for purpose of clarity, is rotatably mounted to the cutting head assembly 106 . The lower blade guard 124 is configured to rotate in a clockwise direction with respect to the cutting head assembly 106 when the cutting head assembly 106 is pivoted toward the turntable 104 thereby exposing the circular saw blade 112 .
[0017] The connection between the motor 110 and the saw blade 112 is further described with reference to FIGS. 2 and 3 . The motor 110 has an output shaft 130 which drives a pinion gear 132 . The pinion gear 132 is operably connected to a gear 134 that drives a clutch/brake assembly 133 . The output of the clutch/brake assembly is the primary braking assembly 138 . The primary braking assembly 138 in one embodiment is the braking assembly described in U.S. Patent Application Publication No. 2011/0048197, the entire contents of which are herein incorporated by reference.
[0018] The primary braking assembly 138 drives a pulley 140 which is operably connected to a pulley 142 by a belt 144 . In some embodiments, the pulley system is replaced by a geared drive system. The pulley 142 is operably connected to a gear 146 which drives a gear 148 operable connected to a drive shaft 150 on which the blade 112 is mounted. The motor 110 , along with the gears and pulleys, are configured such that the blade 112 rotates downwardly.
[0019] The pinion gear 132 is also connected to a reversing gear 152 . The reversing gear 152 drives a gear 154 that drives a secondary clutch/brake assembly. The secondary braking assembly is operatively connected to the hinge F.
[0020] FIG. 2 further shows a safety circuit 160 that is operably connected to the clutch/brake assembly 133 , a blade sensor 162 (located adjacent to the drive shaft 150 in this embodiment), and the motor 110 . The safety circuit 160 includes a processor 164 and a memory 164 . Program instructions within the memory 164 are executed by the processor 164 to perform at least some of the actions ascribed to the safety circuit herein. The safety circuit 160 detects when a user approaches too closely or touches the blade 112 and issues a signal which disengages the clutch 136 and activates the primary braking assembly 138 to rapidly stop as discussed in more detail in the '197 Publication.
[0021] The safety circuit 160 is further connected to the clutch 156 and the secondary braking assembly 158 . Upon sensing a safety condition, a signal is sent to an electromagnet in the clutch/brake assembly 133 and the clutch 156 is released and the secondary braking assembly 158 is activated. Trigger timing of the secondary braking assembly 158 can occur simultaneously with that of the primary braking assembly 138 or after a predetermined time. The timing in some embodiments depends on the particular application (e.g., on miter saw or circular saw). In some miter saw applications such as the embodiment of FIG. 1 , the trigger timing is also a function of the rotational position of the cutting head 106 . The safety circuit in some embodiments is configured to perform availability/operability testing on the primary and secondary braking systems. In the event of a fault detection of the primary braking system and/or secondary braking system, the safety circuit in some embodiments disables the saw from operating. In other embodiments, in the event of a fault detection of the primary braking system, the safety circuit in some embodiments disables the secondary braking assembly and the saw from operating.
[0022] Because the secondary braking assembly 158 works in parallel with the primary braking system 138 , a dynamic balancing mechanism is applied to the saw 100 . The secondary braking assembly 158 is selected to be similar to the primary braking system 138 to reduce destructive energy generated from the primary braking system 138 . The two braking components are sized accordingly.
[0023] Accordingly, when the blade 112 is rotating in the direction of the arrow 200 of FIG. 3 and the primary braking system 138 is activated, a large angular momentum in the direction of the arrow 202 of FIG. 4 is generated which forces the cutting arm 118 to pivot about the pivot 122 in the direction of the arrow 202 . The secondary braking system 158 , however, is rotating in a direction opposite to the primary breaking system 138 because of the reversing gear 152 as indicated by the arrows 204 and 206 in FIG. 3 . Thus, the secondary braking system 158 generates a large angular momentum in the direction opposite to the arrow 202 of FIG. 4 . Sizing of the secondary braking system 158 is necessary as it is desired to minimized the overall tool weight and size. The secondary braking system can be smaller and weigh less than the primary braking system but needs to rotate faster than the primary braking system in order to counteract the force generated by the primary braking system. Other modifications may be used to provide the desired moment arm to counteract the force generated by the primary braking system 138 for other differences between the two systems, such as the location of the systems.
[0024] By way of example, in systems which do not include a hinge, the systems described above are modified such that the secondary brake operates on the housing or base of the system. Accordingly, the primary braking system stops rotation of the saw blade in the same manner described above, while the secondary braking system acts, at the same time as, or shortly after activation of the primary braking system, upon the housing or base to reduce movement of the housing or base.
[0025] In accordance with the above disclosure, a dynamic mechanism is implemented with a primary brake to reduce output force to the structure of a power tool to enable for braking within a predetermined time to mitigate potential injuries. The dynamic mechanism enables balance and control of a power tool such as miter saw head assemblies and circular saws.
[0026] In some embodiments, the dynamic mechanism is a mechanical brake similar to that of the '197 Publication.
[0027] In various embodiments, the dynamic mechanism is sized accordingly based on its rotation speed and the primary brake's rotation speed and its moment of inertia.
[0028] The dynamic mechanism can be configured with the motor spinning in clockwise or counter-clockwise direction depending upon the particular embodiment.
[0029] In some embodiments, the dynamic mechanism is a mechanical brake where braking force can be directed to the blade teeth, blade walls, output shaft, or any drive mechanism. For example, a primary brake can be a mechanical brake such as an aluminum block that makes contact with the blade teeth, or any friction material that makes contact with the blade walls, output shafts, or any drive mechanism
[0030] In some embodiments, the dynamic mechanism is a pyrotechnic mechanism ejecting a mass. In other embodiments, the dynamic mechanism is an electronic brake generated within the motor assembly.
[0031] While shown in a particular configuration, a dynamic mechanism can be configured in any orientation for compactness other than the shown orientation.
[0032] While the disclosure 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 disclosure are desired to be protected. | In one embodiment, an automatic braking system for a pivoting power tool includes a cutting assembly, a cutting arm supporting the cutting assembly, a hinge supporting the cutting arm through a pivot, a primary braking system operably connected to the cutting assembly, a secondary braking system operably connected to the hinge, and a safety circuit configured to sense an unsafe condition and, in response to sensing the unsafe condition, (i) control the primary braking system to oppose rotation of a blade supported by the cutting assembly, and (ii) control the secondary braking system to oppose rotation of the cutting arm. | 8 |
CROSS-REFERENCE
This is a division of Ser. No. 042,431, filed May 25, 1979.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to tools for testing earth formations in boreholes and more particularly for making formation pressure measurements, acquiring information concerning formation permeability and productivity, and retrieving samples of formation fluids.
2. Description of the Prior Art
Formation testing tools of the prior art of which I am aware have a number of deficiencies. It is important that such tools should have an effective failsafe arrangement to assure that the parts that are extended into contact with the formation when the tool is set can be retracted in the event of power failure, so that the tool can be removed from the borehole. The fail-safe arrangements of the prior art that I know of are actuated by a tensioning of the tool suspension cable to shear a pin or the like, and are subject to problems such as unintentional shearing of the pin, or inability to exert the requisite tensioning force due to cable key seating.
Formation testing tools conventionally provide a pre-test chamber or chambers into which a small quantity of formation fluid (typically about 20 c.c.) can be drawn in order to make formation shut in pressure measurements and obtain indications of formation permeability and potential production. Once the pre-test procedure has been initiated, the entire pre-test chamber capacity must be filled with formation fluid before shut in pressure can be determined, which in the case of low permeability formations can consume considerable time. In addition, the lack of control between the initiation and completion of the pre-test procedure precludes desirable flexibility.
Formation testing tools are typically quite long, and a considerable portion of their length is in the sample chamber portion, which is conventionally rigidly attached below the seal pad. While the tool is set, or when attempting to free the tool, this sample chamber portion can be jammed against the wall of the borehole and become differentially stuck.
Formation testing tools of the prior art that I know of have had problems in maintaining isolation of the formation at the seal pad when testing in unconsolidated formations.
Patents that exemplify prior art formation testing tools are U.S. Pat. Nos. 3,811,321, 3,813,936, 3,858,445, 3,859,850, 3,859,851, 3,864,970, 3,924,468, and 3,952,588.
SUMMARY OF THE INVENTION
A first objective of the present invention is to provide an improved failsafe arrangement to ensure the retracting of the seal pad means and backup pad means in the event of equipment malfunction. This is accomplished by providing electrically powered means controllable at aboveground equipment for generating and applying hydraulic setting pressure to extend and set the seal pad means and backup pad means; means for generating signals to be transmitted to above ground equipment, which signals are a measure of the hydraulic setting pressure, and power supply means for the signal generating means; and means operable in response to a failure of the power supply means to effect release of the hydraulic setting pressure and permit retraction of the seal pad means and backup pad means. In one aspect of the invention, the electrically powered means comprises a reversible electric motor coupled to driving means for moving a piston longitudinally of a cylinder which contains hydraulic fluid, and fluid passage means communicating between the cylinder and the seal pad means and backup pad means; and an electromagnetic clutch interposed in the driving means and operable in response to a failure of the power supply means to disengage the driving means. In a further aspect of the invention, the driving means comprises first and second gear reductions and a ball screw and ball nut, with the piston moveable with the ball nut; the electromagnetic clutch is interposed between the first and second gear reductions and has an energizing coil; the energizing coil being connected in series with the power supply means for the signal generating means; and spring bias means within the cylinder and exerting a force on the piston sufficient to overcome the frictional forces present in the ball screw and ball nut and second gear reduction when the electromagnetic clutch is de-energized, such that the piston is moved in the direction to increase the hydraulic fluid volume within the cylinder, thereby effecting release of the hydraulic setting pressure and permitting retraction of the seal pad means and backup pad means.
Another objective of the invention is to provide improved apparatus for achieving formation "shut-in" pressure measurements and for obtaining indications of formation permeability and potential production, and for obtaining formation fluid samples. The improved apparatus provides a formation fluid mini-sample chamber having variable volume, and fluid passage means for communicating between the mini-sample chamber and the formation at the seal pad location; electrically powered means controllable at aboveground equipment to vary at the will of an operator the volume of the mini-sample chamber; means for generating signals to be transmitted to aboveground equipment, which signals are a measure of fluid pressure within the mini-sample chamber; and means for generating further signals to be transmitted to aboveground equipment, which further signals are a measure of the volume of the mini-sample chamber. In accordance with a further aspect of the invention, the electrically powered means comprises a reversible electric motor coupled through a gear reduction to a ball screw and ball nut; with the variable volume mini-sample chamber comprising a cylinder having a sealed upper end and being moveable with the ball nut; a floating piston is disposed within the cylinder and is pressure biased so as to normally close fluid passage means communicating between the formation at the seal pad location and a formation sample chamber; and means are provided to move the floating piston upwardly to open the last mentioned fluid passage means upon a predetermined upward movement of the cylinder.
Another objective of the invention is to provide structure to alleviate the problem of sticking the tool in the borehole. The tool is made up of upper and lower elongated tool body sections and a pivot structure is provided connecting the lower end portion of the upper body section to the upper end portion of the lower body section for limited pivoting movement, with the axis of the pivoting movement being normal to the direction of movement of the seal pad means for extension and retraction. In another aspect of the invention, this pivot structure incorporates a seal valve for the formation sample chamber which is located in the lower tool body section. In accordance with another aspect of the invention, the seal valve comprises a body portion having a cylindrical exterior surface which acts as the pivot pin or journal for the pivot structure. In a further aspect of the invention, the valve body portion has cylindrical interior portions which carry respective first and second pistons disposed at opposite ends of a piston rod; formation fluid passage means communicates between the formation at the seal pad location and the formation sample chamber via the cylindrical interior portion, with the first piston interposed in the passage and movable to open or close the passage; hydraulic fluid passage means communicates between the means for generating and applying setting pressure to the seal pad means and the second piston; and spring bias means is provided to urge the first piston in the direction to close the formation fluid passage. In accordance with a still further aspect of the invention there is provided a third piston reciprocable within a cylinder which on one side of the third piston is open to the exterior of the tool and which on the other side is open to the valve body cylindrical interior portion which carries the first piston, such that force exerted on the third piston in the direction of closing the seal valve is mechanically transmitted to the first piston, while force exerted on the third piston in the direction of opening the seal valve is independent of the first piston.
Another objective of the invention is to provide improved means for maintaining isolation of the formation at the seal pad location when testing in unconsolidated formations. This improved means comprises formation isolation means including hydraulically controlled extendable and retractable seal pad means and backup pad means; the extendable and retractable seal pad means comprising a seal pad, first piston means having a central bore and fixed to the seal pad, and first cylinder means sealingly engaged by said first piston means; closure means sealingly closing the outer end of the first cylinder means and having a central cylindrical bore; a sand screen assembly comprising an elongated piston shaft, sand screen spring means, and piston shaft return bias means; the elongated piston shaft having a first end portion sealingly engaging the closure means central cylindrical bore and movable longitudinally thereof and a first end face, with the first end face being exposed to the well bore annulus when the tool is in operation; the seal pad means having a central opening communicating between the central bore of the first piston means and the earth formation to be tested when the seal pad is set in a well bore; the elongated piston shaft having a second end portion mating with the seal pad central opening and moving longitudinally thereof, and a second end face, with the second end face abutting the earth formation to be tested when the seal pad is set in a well bore; the sand screen spring means comprising a spirally wound spring having numerous turns that are normally separated sufficiently to permit flow of formation fluids as well as sand therethrough, with the inner diameter of the spring loosely mating with the exterior surface of the elongated piston shaft, and means fixing the spring at its outer end portion to the seal pad, with the free portion of the spring extending inwardly along the piston shaft; passage means communicating between the piston shaft second end face and its exterior surface along the length of the spring and beyond the inner end of the spring; abutment means fixed to said piston shaft adjacent the inner end of said passage means, for engaging the spring upon predetermined movement of the piston shaft outwardly toward the earth formation; such that the passage means can become limited to the spaces between the turns of the spring, which spaces are limited to the diameters of sand particles trapped therebetween. In a further aspect of the invention, the passage means are flutes in the exterior surface of the piston shaft. In a further aspect of the invention, the abutment means is a collar fixed to the piston shaft at the inner end of the flutes and mating with or integral with the exterior surface of the piston shaft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing the tool of the present invention suspended in a borehole, with above ground equipment shown as a block.
FIG. 2 is a schematic showing of information that may be produced by a strip chart recorder during operation of the tool.
FIGS. 3-7 are schematic longitudinal section views which, when joined end to end consecutively, show from top to bottom the makeup of a tool in accordance with a preferred embodiment of the invention.
FIG. 8 is a schematic longitudinal section view showing the sample chamber seal valve incorporated in a pivot joint in accordance with a preferred embodiment of the invention.
FIG. 9 is a schematic longitudinal section view showing a sand screen device in accordance with a preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is shown a tool 11 of the present invention suspended in a borehole at the location of a formation to be tested, with a seal pad 13 and backup pads 15 in the set condition. The tool 11 is made up of two primary sections which may be termed the upper tool section 17 and the lower tool section 19. As will be hereinafter more fully explained, the lower section 19 is pivotally connected to the upper section 17 so as to provide limited relative pivoting movement about an axis 21 which is normal to the direction of travel of the seal pad 13 and backup pads 15 when they are being extended or retracted. The cable 23 and winch means 25 by which the tool 11 is suspended and traversed along the borehole, as well as the aboveground equipment shown as a block 27, are conventional, and consequently, need not be described in detail herein.
FIGS. 3-7 show the entire tool 11 in a series of schematic longitudinal section views, with all parts shown as they would be as the tool 11 is being run into the borehole.
The body of the upper tool section 17 may be regarded as made up of several elements, which observing from top to bottom in FIGS. 3-6, are a head sub 29, upper pressure jacket 31, pressure jacket connector sub 33, lower pressure jacket 35, pad block sub 37, and pad block 39.
The head sub 29 is threaded at its upper end portion for connection to a conventional cable head (not shown) and is threaded at its lower end portion for connection to the upper end of the upper pressure jacket 31. Suitable conventional cable connectors 41 are provided to make the electrical connections from the cable head through the head sub 29 to the interior of the upper pressure jacket 31. Since the manner of making the necessary electrical connections in the tool is a matter of conventional practice, the details of such connections are not shown or described herein. The lower end of the upper pressure jacket 31 is threadedly connected to the upper end of the pressure jacket connector sub 33. The upper end of the lower pressure jacket 35 mates in sliding engagement with the exterior surface of the pressure jacket connector sub 33 and is secured thereto by bolts. The lower end of the lower pressure jacket 35 is threadedly connected to the upper end of the pad block sub 37 and the upper end of the pad block 39 is fixed to the lower end of the pad block sub 37 by threaded compression connector means. O-rings 105 are provided at suitable locations at the connections of the body elements of the upper tool section 17 to seal out well bore fluids.
Apparatus for generating and controlling hydraulic pressure to extend and set seal pad means and backup pad means and to release same, may be referred to as the hydraulic power assembly. The hydraulic power assembly is contained within the portion of the upper tool section 17 shown by FIGS. 3 and 4, and comprises an electric motor 43, a first gear reduction 45, an electromagnetic clutch 47, a second gear reduction 49, a ball screw and ball nut assembly 51, and a hydraulic piston and cylinder assembly 53.
The hydraulic power assembly is supported within the upper pressure jacket 31 by the pressure jacket connector sub 33. A primary cylinder 55 of the hydraulic piston and cylinder assembly 53 is threadedly connected at its lower end to the upper end of the pressure jacket connector sub 33 and is threadedly connected at its upper end to the lower end of a bearing assembly retainer structure 57, which in turn is threadedly connected at its upper end to the lower end of a first cylindrical frame structure 59, which is fixed by bolts at its upper flanged end to the lower flanged end of a second cylindrical frame structure 61, which has an upper flanged end. The electric motor 43 (sometimes referred to herein as the setting motor) and its associated first gear reduction 45 are mounted on and fixed by bolts to the upper flanged end of the second cylindrical frame structure 61, with the first gear reduction 45 protruding into the interior of the second cylindrical frame structure 61.
The electric motor 43 drivingly engages the first gear reduction 45 which is connected by coupling means 63 to one side of the electromagnetic clutch 47, the other side of which is connected by coupling means 65 to one side of the second gear reduction 49, which in turn is connected on its other side by coupling means 67 to the upper end of a bearing hub 69 of the ball screw and ball nut assembly 51.
The electric motor 43 is a reversible 110 volt direct current motor which may typically be of the type manufactured by Globe Industries, Inc., of Dayton, Ohio, model number M100M13. Typically, the first gear reduction 45 may be 14:1 and the second bear reduction 49 may be 55:1. The electromagnetic clutch 47 may typically be of a type manufactured by Magtrol, Inc., of Buffalo, New York, model number FC1090313.
The hydraulic piston and cylinder assembly 53 comprises the primary cylinder 55, a secondary cylinder 71, a setting piston 73 and a setting piston return spring 75. The secondary cylinder 71 is disposed within a central bore 77 of the pressure jacket connector sub 33; is fixed therein by a retainer 79 which threadedly engages the lower end of the central bore 77 and protrudes downwardly beyond the retainer 79. The setting piston 73 has a head 81 which sealingly mates with the interior surface 83 of the primary cylinder 55, and an integral tubular extension 85 which protrudes into said secondary cylinder 71 and sealingly engages the interior surface 87 of the secondary cylinder 71 adjacent to entrance thereto. The setting piston 73 has a central bore 89 which extends throughout its length.
The ball screw and ball nut assembly 51 comprises the bearing assembly retainer structure 57, the bearing hub 69, a ball screw 91 and a ball nut 93. The bearing hub 69 is secured by suitable means for rotation within the bearing assembly retainer structure 57 and has a threaded upper extension portion 95 upon which there is mounted an actuator nut 97 which carries a limit switch actuator 99. The travel of the actuator nut 97 is related to the travel of the setting piston 73 so as to limit the latter in both upward and downward directions by actuating a respective limit switch 101, 103 to open the circuit to the setting motor 43. The ball screw 91 is fixed at its upper end to the lower end of the bearing hub 69 and extends downwardly the full length of the primary cylinder 55 and protrudes partially into the setting piston central bore 89. The ball nut 93 engages the ball screw 91 and is threadedly fixed at its lower end to the head 81 of the setting piston 73. The setting piston return spring 75 bears at its upper end against the bearing assembly retainer structure 57 which closes the upper end of the primary cylinder 55, and bears at its lower end on the head 81 of the setting piston 73.
Apparatus for conducting various formation tests and for providing and controlling flow valve means may be referred to for convenience as the mini-sample apparatus. The mini-sample apparatus is contained within the portion of the upper tool section shown by FIGS. 5 and 6, and comprises an electric motor 107, a gear reduction 109, a ball screw and ball nut assembly 111, and a mini-sample cylinder and piston assembly 113.
The mini-sample apparatus is supported within the lower pressure jacket 35 by the pad block sub 37. A third cylindrical support structure 115 is threadedly connected at its lower end to the upper end portion of the pad block 39 and is threadedly connected at its upper end to the lower end of a fourth cylindrical support structure 117. The electric motor 107 (sometimes referred to herein as the mini-sample motor) and its associated gear reduction 109 are mounted on and fixed by bolts to the upper end of the fourth cylindrical support structure 117, with the gear reduction 109 protruding into the interior of the fourth cylindrical support structure 117.
The electric motor 107 drivingly engages the gear reduction 109 which is connected by coupling means 119 to the upper end of a bearing hub 121 of the ball screw and nut assembly 111.
The mini-sample electric motor 107 may be of the same type as the setting motor 43. Typically, the mini-sample motor gear reduction 109 may be 445:1.
The mini-sample piston and cylinder assembly 113 comprises a primary piston structure 123, a primary cylinder 125, a floating piston 127, and a flow line valve body 129. The primary piston structure 123 comprises a piston head portion 131 and a cylindrical housing portion 133 having first and second central bores 135, 137. The piston head portion 131 is threadedly connected to the lower end of the cylindrical housing portion 133 which is also the lower end of the first central bore 135. The piston head portion 131 is reciprocable within the primary cylinder 125 formed by a central bore in the lower end of the pad block sub 37. The upper end of the first central bore 135 is sealingly closed by a pressure sensor adapter 139. The second central bore 137 has a threaded connection at its upper end to the ball nut 141 of the ball screw and ball nut assembly 111, and the second central bore 137 receives the ball screw 143 of the ball nut and screw assembly 111 as the ball nut 141 is moved upwardly.
The flow line valve body 129 is a generally cylindrical structure having a flanged upper end portion merging with an exterior threaded portion which in turn merges with cylindrical exterior sealing surfaces. The flow line valve body has a central bore 145, an annular exterior groove 147 disposed between said sealing surfaces, and flow passages communicating between the annular groove 147 and the central bore 145. The pad block 39 is provided a bore 149 for threadedly receiving said flow line valve body 129 and matingly receiving said sealing surfaces.
The floating piston 127 has a head portion 151 in sealing engagement with and reciprocable within the first central bore 135 of the primary piston structure 123 and an integral downwardly extending tubular extension 153 having an exterior sealing surface 155 at its lower end portion which is matingly received by the flow line valve body central bore 145. The upper surface of the floating piston head portion 131, the lower surface of the pressure sensor adapter 139 and the portion of the primary piston structure first central bore 135 between these surfaces formed a mini-sample chamber 159 having variable volume, as will be hereinafter explained. The floating piston 127 has a fluid passage 161 communicating between the mini-sample chamber 159 and the lower end of the pad block bore 149.
The ball screw and ball nut assembly 111 comprises a bearing assembly retainer structure 157, the bearing hub 121, the ball screw 143, and the ball nut 141. The bearing hub 121 is secured by suitable means for rotation within the bearing assembly retainer structure 157. The ball screw 143 is fixed at its upper end to the lower end of the bearing hub 121 and extends downwardly through the ball nut 141.
A limit switch actuator 163 is mounted on the primary piston structure 123 and is movable with the ball nut 141 between upper and lower limit switches 165, 170. The limit switches 165, 170 are connected in the power supply circuit of the mini-sample motor 107 so as to stop the motor when actuated. Thus, the travel of the ball nut 141 (and hence the primary piston structure 123) is limited.
A series of longitudinally extending cam notches 169 are provided on the exterior surface of the upper end portion of the primary piston structure for coaction with the cam actuator 171 of a microswitch 173 which is mounted to the third cylindrical support structure 115. The microswitch 173 produces an output pulse each time the cam actuator 171 traverses a cam notch 169. Each cam notch 169 represents an increment of mini-chamber 159 volume (typically 2 c.c.).
The tool 11 has an electronics section 175 comprising various components mounted on a chassis 177 located in a space between the upper end of the mini-sample motor 107 and the lower end of the secondary cylinder 71 of the hydraulic piston and cylinder assembly 53. The electronics section chassis 177 is secured at its upper end to the lower end portion of the secondary cylinder 71.
A hydraulic fluid or seal pad setting pressure sensor 179 is mounted in the end of the secondary cylinder 71. A formation fluid pressure sensor 181 is mounted in the pressure sensor adapter 139 of the mini-sample apparatus.
Power (110 volts direct current) is supplied from the aboveground equipment via cable 23 and connectors 41 separately to each of the setting motor 43 and the mini-sample motor 107 in series with respective limit switches 101, 103 and 163, 165, so that each motor 43, 107 can be separately controlled by the aboveground operator. Power (26 volts direct current) is also supplied from the aboveground equipment to the electronics section 175, in series with the energizing coil of the electromagnetic clutch 47, so that the electromagnetic clutch 47 is de-energized to disengage when and if there is a failure in the 26 volt direct current power supply. The electronics section 175 includes a power supply and amplifiers for the pressure sensors 179, 181 and also a power supply and amplifier for the circuit of microswitch 173. Output signals from each pressure sensor amplifier and the microswitch circuit amplifier are transmitted to the aboveground equipment via the cable 23. Since the electronics section, the power supply conductors and various electrical connections are matters within the scope of conventional practice, these are not shown or described in detail herein.
An inner cylindrical jacket 183 is received within the lower pressure jacket 35 and is matingly and sealingly received at its upper end by a cylindrical external surface portion 185 of the pressure jacket connector sub 33 and is further matingly and sealingly received at its lower end by an exterior cylindricl surface 187 at the upper end of the pad block sub 37.
The pad block 39 carries a sealing pad assembly 189, upper and lower backup pad assemblies 191, 193 and an equalizer valve assembly 195.
The sealing pad assembly 189 comprises a sealing pad 197, sealing pad retainer 199, sealing pad plate 201, upper and lower sealing pad guide rods 203, 205, sealing pad piston 207, sealing pad piston plug 209, and sealing pad cylinder 211. The sealing pad 197 is made of a resilient material such as rubber, which typically may be 60-90 durometer nitrile rubber, and has a generally rectangular shape, with some curvature in transverse section so as to generally conform to the borehole wall curvature. The sealing pad plate 201 is a metal plate that can cover a large portion of the inner surface of the sealing pad 197. The upper and lower sealing pad guide rods 203, 205 are secured by bolts to the sealing pad plate 201 adjacent its respective upper and lower edges and are reciprocable in respective mating bores (not shown) in the pad block 39. The sealing pad retainer 199 is generally cylindrical having a flanged outer end, a cylindrical exterior portion 200 matingly received by a sealing pad central bore, and an exterior threaded portion at its inner end which engages internal threads at the outer end of the sealing pad piston 207. When the sealing pad retainer 199 is in place, the sealing pad 197 is clamped between the retainer flanged outer end and the sealing pad plate, and the sealing pad plate is clamped between the sealing pad inner surface and the outer end face of the sealing pad piston 207. Thus, the sealing pad 197 and sealing pad plate 201 are securely fixed relative to the sealing pad piston 207.
The sealing pad retainer 199 has a cylindrical bore 202 at its inner end portion which merges with a threaded intermediate bore 204 of smaller diameter which in turn merges with an outer end bore of still smaller diameter, for a purpose to be hereinafter explained. The sealing pad piston 207 has a first exterior cylindrical surface 206 that extends over about half its length from the center portion outwardly toward the sealing pad 197 and a second cylindrical exterior surface 208 of smaller diameter extending from the center portion inwardly to the inner end. The sealing pad piston 207 has a cylindrical central bore 210 extending between the internal threads 222 at the outer end portion and internal threads 224 at the inner end portion, which cylindrical central bore 210 merges with and has the same diameter as the cylindrical bore 202 at the inner end of the sealing pad retainer 199.
The pad block 39 has a central transverse bore 213 having a first cylindrical portion 212 matingly and sealingly receiving the first exterior cylindrical surface of the sealing pad piston 207 and merging with a second cylindrical portion 214 of increased diameter for providing a fluid flow passage to and around the sealing pad piston 207, and merging with a third cylindrical portion 216 of further increased diameter for receiving a cylindrical exterior portion of the sealing pad cylinder 211, and merging with a fourth cylindrical portion 218 of further increased diameter for matingly and sealingly receiving a second cylindrical exterior portion of the sealing pad piston 207, and merging with a fifth cylindrical threaded portion 220 of further increased diameter for receiving a threaded exterior portion of the sealing pad cylinder 211.
The sealing pad piston plug 209 has a cylindrical exterior portion 215 that matingly and sealingly engages a first cylindrical interior surface 217 of the sealing pad cylinder 211 and merges with a threaded cylindrical portion 219 of reduced diameter which engages the threads 224 at the inner end portion of the sealing pad piston 207. The threaded cylindrical portion 219 has a plurality of longitudinally extending grooves 221 which extend to communicate with corresponding lateral bores 223 to provide fluid passages between the second exterior cylindrical surface 208 of the sealing pad piston 207 and its interior. The sealing pad cylinder 211 has a second interior cylindrical surface 225 of lesser diameter than the first cylindrical interior surface 217 and which matingly and sealingly engages the second exterior cylindrical surface 208 of the sealing pad piston 211. A shoulder 227 on the exterior surface of the sealing pad piston at the juncture of the first and second exterior cylindrical surfaces 206, 208 of the sealing pad piston 211 abuts the inner end surface of the sealing pad cylinder 211 to provide a stop for the sealing pad piston 211 in the retracting direction.
The upper backup pad assembly 191 comprises a piston shaft 229, a backup pad 231, a seal plug 233, and a guard pad 235. A transcerse bore 237 in the pad block 39 receives the piston shaft 229 and seal plug 233. The backup pad 231 is made of metal; is generally disc shaped; and is fixed to the outer end of the piston shaft 229. The seal plug 233 is fixed to the pad block 39 at the entrance to the transverse bore 237 by threads 239 and has a circumferential groove 241 in its exterior surface to provide a fluid passage. The piston shaft 229 matingly and sealingly engages a first interior cylindrical portion 243 of the seal plug 233 located at the seal plug outer end portion; which interior cylindrical portion 243 merges with a second interior cylindrical portion 245 of greater diameter, which second interior cylindrical portion 245 in turn merges with an interior cylindrical portion 247 of the transverse bore 237. The guard pad 235 is sealingly fixed to the pad block exterior surface by bolts and serves to protect the sealing pad 197. The guard pad 235 has a central cavity 249 which receives the inner end portion of the piston shaft 229.
The lower backup pad assembly 193 is like the upper backup pad assembly 191 except that its seal plug 251 does not incorporate circumferential groove 241 and consequently does not provide the associated fluid passage.
The equalizer valve assembly 195 comprises a piston 253, a seal ring 255, a retainer plug 257 and a bias spring 259. The pad block 39 is provided a bore 261 for receiving the equalizer valve assembly 195. The piston 253 matingly and sealingly engages adjacent its inner end a portion 263 of the pad block bore 261 and adjacent is outer end a central bore 265 of the seal ring 255. The inner end of the piston is exposed to a hydraulic fluid flow passage, while the outer end is exposed to well bore fluid. The retainer plug 257 threadedly engages the outer end portion of the pad block bore 261 to hold the seal ring 255 in place within a portion of the pad block bore 261. The bias spring 259 bears at one end on the seal ring 255 and at the other end on a shoulder on the piston 253, so as to urge the piston inwardly for a purpose to be hereinafter explained.
The lower tool section 19, with the exception of the pivot assembly 277, is of a conventional design and consequently will be described only briefly herein. The body of the lower tool section 19 may be regarded as made up of several elements, which, observing from top to bottom in FIG. 7, are a bleed off sub 267, a formation sample chamber 269, a chamber connector sub 271, a cushion chamber 273, and a bull plug 275.
The bleed off sub 267 is threadedly connected at its lower end portion to the upper end portion of the formation sample chamber 269 which is threadedly connected at its lower end portion to the upper end portion of the chamber connector sub 271 which is threadedly connected at its lower end portion to the upper end portion of the cushion chamber 273 which is threadedly connected at its lower end portion to the bull plug 275.
The bleed off sub 267 has a transverse bore 279 which on one side carries a seal plug 281 and on the other side carries a bleed off valve 283. A formation sample fluid passage 285 in the bleed off sub communicates from the pivot assembly 277 via the bleed off valve 283 to the volume of the sample chamber interior above a sample chamber piston 287. The sample chamber volume below the sample chamber piston 287 contains water which is forced via a choke assembly 289 carried by the chamber connector sub 271 into the volume of the cushion chamber 273 above a cushion chamber piston 291, as the sample chamber piston 287 is moved downwardly. The cushion chamber volume below the cushion chamber piston 291 contains air. A separate fluid passage 293 communicates between the lower end of the formation sample chamber 269 and the upper end of the cushion chamber 273 via the chamber connector sub 271 and a check valve 295. Suitable seals are provided within the lower tool section by various O-rings 297.
As hereinbefore stated, the lower tool section 19 is pivotally connected to the upper tool section 17 so as to provide limited relative pivoting movement about an axis 21 which is normal to the direction of travel of the seal pad 13 and backup pads 15 when they are being extended or retracted. The pivot assembly 277 (see FIG. 8) comprises first and second upper tool section pivot bearing protrusions 299, 301, a lower tool section pivot bearing protrusion 303, and a formation sample chamber seal valve assembly 305 which comprises a seal valve body 307, a piston rod 309 having first and second pistons 311, 313 carried on its opposite ends, a bias spring 331, a third piston 315, and a retainer cylinder 317.
The first and second upper tool section pivot bearing protrusions 299, 301 are integral with and extend downwardly from the lower end of the pad block 39 in parallel juxtaposed relation and have respective coaxial transverse bores 319, 321 of equal diameter. The lower tool section pivot bearing protrusion 303 is integral with and extends upwardly from the upper end of the bleed off sub 267 and into the slot 322 formed between the first and second protrusions 299, 301. The lower tool section pivot bearing protrusion 303 has a transverse bore 325 coaxial with and of the same diameter as the respective bores 319, 321 of the first and second protrusions 299, 301. These transverse bores form the bearing box or bearing surfaces for the pivot pin or journal of the pivot assembly 277, which in the embodiment shown, is the seal valve body 307.
The seal valve body 307 has a cylindrical exterior surface 327 that is sealingly and matingly received within the transverse bores 319, 321 325. The transverse bore 321 of the second bearing protrusion 301 does not extend all of the way through the protrusion, and a chamber is formed at the inner end portion of the seal valve body 307 which communicates with a hydraulic fluid flow passage 329 in the pad block 39.
The retainer cylinder 317 threadedly and sealingly engages the outer portion of the transverse bore 319 and has a cylindrical interior portion 343 which matingly and sealingly engages the third piston 315. The seal valve body 307 has a first cylindrical interior surface 333 that matingly and sealingly receives the second piston 313 and a second cylindrical interior surface 335 of smaller diameter that matingly and sealingly receives the first piston 311. Fluid passage means 337 is provided at the inner end portion of the retainer cylinder to communicate with a formation fluid flow passage 339 in the pad block 39. Another fluid passage means 341 is provided in the seal valve body 307 to communicate between the valve body interior and a formation fluid flow passage 285 in the bleed off sub 267.
When the tool 11 is operated in a borehold where unconsolidated formations may be encountered, the sand screen assembly 345 shown by FIG. 9 is utilized. To install the sand screen assembly 345, the sealing pad piston plug 209 (see FIG. 6) is removed and the sand screen assembly 345 is inserted in the cavity made up of the cylindrical bore 202 of the sealing pad retainer 109, the cylindrical central bore 210 of the sealing pad piston 207 and the space vacated by the piston plug 209.
The sand screen assembly 345 comprises a sand screen plug 347, an elongated piston shaft 349, a sand screen spring 351 and a bias spring 353. The sand screen plug 347 is like the sealing pad piston plug 209 that it replaces, except that the sand screen plug 347 has a central bore 355 for matingly and sealingly receiving the outer portion of the piston shaft 349 for reciprocable movement therein. The outer end face of the piston shaft 349 is thus exposed to the well bore when the tool 11 is in operation. The inner end portion of the piston shaft 349 is received by the outer end bore of the sealing pad retainer 199, so that the outer end face of the piston shaft 349 can move into abutting relation with the earth formation being tested when the tool 11 is in operation. The bias spring 353 bears at one end on a shoulder formed at the juncture of the sealing pad retainer cylinder bore 202 and the threaded intermediate bore 204, and at the other end on a ring 357 which is held against outward movement by roll pins 359 carried by the piston shaft 349. When the bias spring 353 is relaxed, the piston shaft 349 is positioned such that its outer end is flush with the outer face of the sand screen plug 347. The sand screen spring 351 is a spirally wound spring having numerous turns that are normally separated sufficiently to permit flow of formation fluids as well as sand therethrough. The inner diameter of the sand screen spring 351 mates loosely with the exterior surface of the piston shaft 349 and the sand screen spring is secured at its inner end by threading onto the threaded intermediate bore 204 of the sealing pad retainer 199. The sand screen spring 351 typically may have fifty turns in about 11/2" of length when relaxed and shortens to about 11/8" when fully compressed. The piston shaft 349 is provided passage means (shown as spiral flutes 361) communicating between the outer end face of the piston shaft 349 and its exterior surface along the length of the sand screen spring 351 and a short distance (typically about 1/4") beyond the inner end of the sand screen spring 351. Abutment means, shown as a collar 363, is fixed to the piston shaft 349 adjacent the inner end of the passage means 361, for engaging the sand screen spring 351 upon predetermined movement of the piston shaft 349 outwardly toward the earth formation. Passage means 365 are provided between the outer end face of the piston shaft 349 and the spiral flutes 361. The inner and outer end faces of the piston shaft 349 have equal diameters, so that the piston shaft 349 will not move as the tool 11 is being traversed into the borehole, since well bore fluid pressures on the end faces of the piston 349 are balanced.
When the tool 11 has reached the test site and the sealing pad assembly 189 has been extended and set in sealing engagement with the formation and the volume of the mini-sample chamber 159 has been expanded, then the pessure force on the inner face of the piston shaft 349 will be less than that on the outer face, so that the piston shaft 349 will be continually urged into contact with the formation. Initially, the turns of the sand screen spring 351 will be separated and formation fluid including sand can pass through the turns of the sand screen spring 351 and also through the space between the outer end of the sand screen spring 351 and the inner end of the collar 363. As the unconsolidated formation is eroded, the piston shaft 349 moves inwardly so that the inner end face of the collar 363 abuts the outer end of the sand screen spring 351 and compresses same. The sand screen spring 351 will not fully compress because of sand particles that become trapped between the spring turns. Thus, eventually, the only flow path from the formation via the piston shaft passage means 365 to the interior of the sealing pad piston 207 is between the compressed turns of the sand screen spring 351. Since no more sand can pass between the turns of the sand screen spring 351, the formation ceases to erode and only formation fluid is passed through the sand screen spring. When the formation test is completed and well bore fluid pressure again acts on the inner end of the piston shaft 349, the pressure forces on the ends of the piston shaft 349 will again be balanced, allowing the bias spring 353, which was compressed by movement of the piston shaft 349 inwardly, to move to its relaxed position, returning the piston shaft 349 to its original position. As the piston shaft 349 returns toward its original or initial position, the turns of the sand screen spring 351 are wiped by the spiral flutes 361 to clean off the sand particles.
It will be convenient to describe the operation of the tool 11 with reference to FIG. 2 which schematically presents certain information that is produced by a strip chart recorder and is observed by the operator at the aboveground equipment location during operation of the tool.
In FIG. 2, the trace A represents hydraulic pressure sensed by hydraulic fluid pressure sensor 179 on a scale of 0-5,000 p.s.i. The trace B represents the pulses produced each time the cam actuator 171 traverses a cam notch 169. In the embodiment shown, each pulse represents a two c.c. volume increment of mini-chamber 159 volume. The digital printout column C shows in p.s.i., at predetermined time intervals (typically 5 seconds), the pressure sensed by formation fluid pressure sensor 181. Trace D represents the pressure sensed by the formation fluid or hydrostatic pressure sensor 181 on a scale of 0-10,000 p.s.i.; while trace E represents the pressure sensed by the formation fluid pressure sensor 181 on a scale from 0-1,000 p.s.i.
As the tool 11 is run into the borehole, all parts are in the positions shown by FIGS. 3-7. When the tool 11 is stopped at the depth of the earth formation to be tested, the operator energizes the setting motor 43 for rotation in the direction to cause ball nut 93 to move upwardly, bringing with it the setting piston 73. As the setting piston 73 moves upwardly, hydraulic fluid is forced out of the primary cylinder 55 and via various fluid passage means to the interior of the sealing pad piston 207 and the interiors of the upper and lower backup pad assemblies 191, 193, thus causing the sealing pad 197 and the backup pads 231 to be extended into contact with the wall of the well bore. This hydraulic fluid flow path can be traced from the interior of the primary cylinder 55 through the ball nut 93, through the setting piston central bore 89 to the interior of the secondary cylinder 71 and via a passage 367 to the space between the lower pressure jacket 35 and the inner cylinder jacket 183 to a hydraulic fluid pressure passage 369 in pad block sub 37 and through a connector valve assembly 371 to a hydraulic fluid passage 373 in pad block 39. This hydraulic fluid flow path is isolated by means of various o-ring seals. When the hydraulic fluid pressure reaches a value which is about 1,5000 p.s.i. above the well bore pressure, then the sealing pad 197 is considered to be set, thus isolating the formation at the sealing pad location. In FIG. 2 it can be seen that this event occurs at the point 375 of trace A and at a readout of about 1,623 pounds on trace C. When the point 375 is observed by the operator, he de-energizes setting motor 43.
Next, the operator energizes the mini-sample motor 107 for rotation in the direction to cause ball nut 141, and consequently primary piston structure 123, to move upwardly. Upward movement of the primary piston structure 123 causes the volume of mini-sample chamber 159 to begin to increase. The mini-sample chamber communicates with the formation being tested at the seal pad location via passage means which can be traced from the mini-sample chamber 159 through the floating piston fluid passage 161 to the circumferential groove 241 in seal plug 233, through a passage in the pad block 39 to the pad block bore 261 for the equalizer valve assembly 195 and through a further passage in pad block 39 to the third cylindrical portion 216 of the pad block central transverse bore 213 and through openings in the wall of sealing pad cylinder 211 and through bores 223 and sealing pad piston plug 209 and the grooves 221 in threaded cylinder portion 219 of sealing pad piston plug 209 to the interior of the sealing pad piston 207 which is exposed to the earth formation at the sealing pad location. This formation fluid path is isolated by means of various o-ring seals, so long as the equalizer valve 195 is closed.
The pressure forces acting on the upper end of the floating piston 127 are always greater than those acting on its lower end because of unequal surface areas, and consequently the floating piston is always urged downwardly by the differential pressure forces. Thus, the floating piston 127 remains in its extreme downward position as the primary piston structure 123 is moved upwardly. In the example shown by FIG. 2, the operator permits the primary piston structure 123 to move upwardly until five pulses have been generated on trace B, showing that the mini-sample chamber volume 159 has increased to 10 c.c. Observing trace E of FIG. 2, it will be seen that the fluid pressure in the mini-sample chamber 159, as sensed by the formation fluid pressure sensor 181 rapidly decreases as the mini-sample chamber volume is increased. As seen by the pressure readout in column C, the mini-sample chamber pressure has decreased from 1,623 p.s.i. to 1,087 p.s.i. and soon thereafter increases and stabilizes at about 1,279 p.s.i. (see also trace E). This is the "shut-in" pressure of the formation being tested.
It will be observed that it was only necessary for the operator to open the mini-sample chamber sufficiently to cause the pressure therein to drop to a point considered to be below the likely formation shut-in pressure and then de-energize the mini-sample motor 107 and wait for the mini-sample chamber pressure to build up and stabilize, at which point the formation "shunt-in" pressure will have been reached. When the formation being tested has a low permeability, only a small amount (perhaps only 2 c.c.) of formation fluid need be drawn into the mini-sample chamber to achieve formation "shunt-in" pressure. If it were necessary to wait for a large test sample chamber to fill before formation "shunt-in" pressure is achieved, this could take a long time in the case of low permeability formations. An important feature of the present invention is the provision for a variable volume mini-sample chamber which can be monitored at aboveground equipment and controlled at the will of an operator.
Next, the mini-sample motor 107 is again energized in the direction to continue upward movement of the ball nut 141 and consequently the primary piston structure 123, generating a second series of pulses on trace B of FIG. 2. After a predetermined upward movement of the primary piston structure 123, a shoulder on the upper end of piston head portion 131 engages a shoulder on the lower side of the head portion 151 of the floating piston 127, forcing the floating piston 127 to move upwardly away from seal means 377 to open a flow passage from the floating piston fluid passage 161 to the groove 147 in the flow line valve body 129 and through passage means including fluid flow passage 339 in the pad block 39 and via the seal valve 305 and a further formation fluid flow passage 285 in the bleed off sub 267 and through the bleed off valve 283 and further fluid flow passage 285 into the formation sample chamber 269.
It should be noted (see FIG. 8) that the sample chamber seal valve 305 is normally urged to its closed position under the force of bias spring 331 because the second and third pistons 313, 315 have the same diameter and are exposed to well bore pressure. The piston 313 is exposed to hydraulic fluid via the hydraulic fluid flow passage 329. The piston 313 is subjected to hydraulic fluid pressure generated by the action of the setting motor 43 and consequently the piston rod 309 and first piston 311 are moved outwardly to open the seal valve 305 thus permitting formation to flow from passage 339 to the interior of the seal valve body 307. The equalizer valve inner end face is also subjected to hydraulic fluid pressure generated by the action of the setting motor 43 and is moved to the closed position by such hydraulic fluid pressure.
The opening of the formation fluid flow line (upon sufficient upward movement of floating piston 127) results in a drastic pressure drop within the mini-sample chamber as sensed by the formation fluid pressure sensor 181. This event is observed by the operator at point 379 on trace A and also in the pressure readout column C where the pressure reading suddenly drops from 1,183 p.s.i. to 159 p.s.i. At this point, the operator stops the mini-sample motor 107 (or it is stopped by a limit switch) and waits for the formation sample chamber 269 to fill. As the formation sample chamber 269 is filled, the formation pressure readings (in column C of FIG. 2) gradually increased until the formation "shut-in" pressure is again reached (when the column C readouts show about 1,272 p.s.i.). After the formation "shut-in" pressure has again been reached, indicating that the formation sample chamber 269 is full, the operator again energizes mini-sample chamber motor 107 to rotate in the reverse direction, thus moving the primary piston structure 123 downwardly, permitting the floating piston 127 to move downwardly to its lower most position, thus closing the formation fluid flow passage through the flow line valve body 129. Then, downward movement of the primary piston structure 123 is continued in order to expel the formation sample fluid from the mini-sample chamber 159. The operator, monitors the volume condition of the mini-sample chamber 159 by watching the series of pulses on trace B of FIG. 2.
Next, the operator energizes the setting motor 43 in the reverse direction to cause the setting piston 73 to move downwardly, increasing the volume of the primary cylinder 55 thus reducing the hydraulic fluid pressure. This hydraulic fluid pressure reduction permits the equalizer valve 195 to open, and the seal valve 305 to close. Thus, the formation sample chamber 269 is sealed. Also, well bore fluid is admitted to the interior of the sealing pad piston 207 and consequently onto the formation at the sealing pad location, which results in equalization of pressures on the sealing pad 197 causing it to release its contact with the formation. Differential pressures on the sealing pad assembly 189 and the upper and lower backup pad assemblies 191, 193 cause them to retract to their running in positions. The rapid reduction in hydraulic pressure resulting from the reversing of the setting motor 43 may be noted on trace A of FIG. 2 between the points 381 and 383. The operator can also notice from column C of FIG. 2 that the equalizer valve has opened when the pressure readout returns to normal well bore pressure (at about 1,495 p.s.i.).
It should be noted that the herein disclosed arrangement of mini-sample apparatus makes it possible to open and close the flow line path at the flow line valve body 129 and vary the volume of the mini-sample chamber 159 independently of any other function of the tool 11. This makes possible certain operator options. First, as hereinabove mentioned, the waiting time for achieving formation "shut-in" pressure can be greatly reduced. Second, the formation fluid flow line can be opened and re-closed during a sample test in order to unplug the flow path by injecting fluid in the mini-sample chamber 159 back through the system and into the formation at the seal pad location. Third, a formation "shut-in" pressure test can be performed at any time either while the formation fluid sample chamber 269 is being filled, or thereafter, by closing the formation flow line passage at the flow line valve body 129. Further, all of the functions above-mentioned can be performed independently of the sealing pad setting function. | A tool for testing earth formations in boreholes provides a failsafe function for retracting the sealing pad elements of a formation isolation device, in the form of elements operable in response to failure of downhole power supply for the tool to effect release of hydraulic setting pressure on the seal pad elements. The tool further provides a formation mini-sample chamber of variable volume with elements permitting aboveground monitoring and control of same independently of any other tool function. The mini-sample chamber control device also controls the operation of a formation fluid sample flow line valve. The tool is divided into upper and lower pivotable sections to alleviate the problem of becoming differentially stuck. A unique pivot structure incorporating sample chamber seal valve assembly, is provided. A unique sand screen device is provided to permit the tool to function when working wih unconsolidated formations. | 4 |
CROSS REFERENCE TO OTHER APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/589,006, entitled STREAM SEGREGATION FOR STEREO SIGNALS filed Oct. 27, 2006 now U.S. Pat. No. 7,315,624, which is incorporated herein by reference for all purposes, which is a continuation of application Ser. No. 10/163,168, now U.S. Pat. No. 7,257,231, entitled STREAM SEGREGATION FOR STEREO SIGNALS filed Jun. 4, 2002 which is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
The present invention relates generally to audio signal processing. More specifically, stream segregation for stereo signals is disclosed.
BACKGROUND OF THE INVENTION
While surround multi-speaker systems are already popular in the home and desktop settings, the number of multi-channel audio recordings available is still limited. Recent movie soundtracks and some musical recordings are available in multi-channel format, but most music recordings are still mixed into two channels and playback of this material over a multi-channel system poses several questions. Sound engineers mix stereo recordings with a very particular set up in mind, which consists of a pair of loudspeakers placed symmetrically in front of the listener. Thus, listening to this kind of material over a multi-speaker system (e.g. 5.1 surround) raises the question as to what signal or signals should be sent to the surround and center channels. Unfortunately, the answer to this question depends strongly on individual preferences and no clear objective criteria exist.
There are two main approaches for mixing multi-channel audio. One is the direct/ambient approach, in which the main (e.g. instrument) signals are panned among the front channels in a frontally oriented fashion as is commonly done with stereo mixes, and “ambience” signals are sent to the rear (surround) channels. This mix creates the impression that the listener is in the audience, in front of the stage (best seat in the house). The second approach is the “in-the-band” approach, where the instrument and ambience signals are panned among all the loudspeakers, creating the impression that the listener is surrounded by the musicians. There is an ongoing debate about which approach is the best.
Whether an in-the-band or a direct/ambient approach is adopted, there is a need for better signal processing techniques to manipulate a stereo recording to extract the signals of individual instruments as well as the ambience signals. This is a very difficult task since no information about how the stereo mix was done is available in most cases.
The existing two-to-N channel up-mix algorithms can be classified in two broad classes: ambience generation techniques which attempt to extract and/or synthesize the ambience of the recording and deliver it to the surround channels (or simply enhance the natural ambience), and multichannel converters that derive additional channels for playback in situations when there are more loudspeakers than program channels. In the latter case, the goal is to increase the listening area while preserving the original stereo image. Multichannel converters can be generally categorized in the following classes:
1) Linear matrix converters, where the new signals are derived by scaling and adding/subtracting the left and right signals. Mainly used to create a 2-to-3 channel up-mix, this method inevitably introduces unwanted artifacts and preservation of the stereo image is limited.
2) Matrix steering methods which are basically dynamic linear matrix converters. These methods are capable of detecting and extracting prominent sources in the mix such as dialogue, even if they are not panned to the center. Gains are dynamically computed and used to scale the left and right channels according to a dominance criterion. Thus a source (or sources) panned in the primary direction can be extracted. However, this technique is still limited to looking at a primary direction, which in the case of music might not be unique.
While the techniques described above have been of some use, there remains a need for better signal processing techniques for multichannel conversion and developing better techniques for manipulating existing stereo recordings to be played on a multispeaker system remains an important problem.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
FIG. 1 is a block diagram illustrating how upmixing is accomplished in one embodiment.
FIG. 2 is a block diagram illustrating the ambience signal extraction method.
FIG. 3A is a plot of this panning function as a function of α.
FIG. 3B is a plot of this panning function as a function of α.
FIG. 4 is a block diagram illustrating a two-to-three channel upmix system.
FIG. 5 is a diagram illustrating a coordinate convention for a typical stereo setup.
FIG. 6 is a diagram illustrating an up-mix technique based on a re-panning concept.
FIGS. 7A and 7B are plots of the desired gains for each output time frequency region as function of α assuming an angle θ=60°.
FIGS. 7C and 7D are plots of the modification functions.
FIGS. 8A and 8B are plots of the desired gains for θ=30°.
FIGS. 8C and 8D are plots of the corresponding modification functions for θ=30°.
FIG. 9 is a block diagram illustrating a system for unmixing a stereo signal to extract a signal panned in one direction.
FIG. 10 is a plot of the average energy from an energy histogram over a period of time as a function of F for a sample signal.
FIG. 11 is a diagram illustrating an up-mixing system used in one embodiment.
FIG. 12 is a diagram of a front channel upmix configuration.
DETAILED DESCRIPTION
It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, or a computer readable medium such as a computer readable storage medium or a computer network wherein program instructions are sent over optical or electronic communication links. It should be noted that the order of the steps of disclosed processes may be altered within the scope of the invention.
A detailed description of one or more preferred embodiments of the invention are provided below along with accompanying figures that illustrate by way of example the principles of the invention. While the invention is described in connection with such embodiments, it should be understood that the invention is not limited to any embodiment. On the contrary, the scope of the invention is limited only by the appended claims and the invention encompasses numerous alternatives, modifications and equivalents. For the purpose of example, numerous specific details are set forth in the following description in order to provide a thorough understanding of the present invention. The present invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the present invention is not unnecessarily obscured.
Stereo Recording Methods
It is possible to use certain knowledge about how audio engineers record and mix stereo recordings to derive information from the recordings. There are many ways of recording and mixing a musical performance, but we can roughly categorize them into two classes. In the first class, or studio recording, the different instruments are recorded in individual monaural signals and then mixed into two channels. The mix generally involves first panning in amplitude the monaural signals individually so as to position each instrument or set of instruments in a particular spatial region in front of the listener (in the space between the loudspeakers). Then, ambience is introduced by applying artificial stereo reverberation to the pre-mix. In general, the left and right impulse responses of the reverberation engine are mutually de-correlated to increase the impression of spaciousness. In this description, we refer to two channel signals as left and right for the purpose of convenience. It should be noted that the distinction is in some cases arbitrary and the two signals need not actually represent right and left stereo signals.
The second class, or live recording, is done when the number of instruments is large such as in a symphony orchestra or a jazz big band, and/or the performance is captured live. Generally, only a small number of spatially distributed microphones are used to capture all the instruments. For example, one common practice is to use two microphones spaced a few centimeters apart and placed in front of the stage, behind the conductor or at the audience level. In this case the different instruments are naturally panned in phase (time delay) and amplitude due to the spacing between the transducers. The ambience is naturally included in the recording as well, but it is possible that additional microphones placed some distance away from the stage towards the back of the venue are used to capture the ambience as perceived by the audience. These ambience signals could later be added to the stereo mix at different levels to increase the perceived distance from the stage. There are many variations to this recording technique, like using cardioid or figure-of-eight microphones etc., but the main idea is that the mix tries to reproduce the performance as perceived by a hypothetical listener in the audience.
In both cases the main drawback of the stereo down-mix is that the presentation of the material over only two loudspeakers imposes a constraint on the spatial region that the can be spanned by the individual sources, and the ambience can only create a frontal image or “wall” that does not really surround the listener as it happens during a live performance. Had the sound engineer had more channels to work with, the mix would have been different and the results could have been significantly improved in terms of creating a realistic reproduction of the original performance.
Upmixing
In one embodiment, the strategy to up-mix a stereo signal into a multi-channel signal is based on predicting or guessing the way in which the sound engineer would have proceeded if she or he were doing a multi-channel mix. For example, in the direct/ambient approach the ambience signals recorded at the back of the venue in the live recording could have been sent to the rear channels of the surround mix to achieve the envelopment of the listener in the sound field. Or in the case of studio mix, a multi-channel reverberation unit could have been used to create this effect by assigning different reverberation levels to the front and rear channels. Also, the availability of a center channel could have helped the engineer to create a more stable frontal image for off-the-axis listening by panning the instruments among three channels instead of two.
To apply this strategy, we first undo the stereo mix and then remix the signals into a multi-channel mix. Clearly, this is a very ill-conditioned problem given the lack of specific information about the stereo mix. However, the novel signal processing algorithms and techniques described below are useful to achieve this.
A series of techniques are disclosed for extracting and manipulating information in the stereo signals. Each signal in the stereo recording is analyzed by computing its Short-Time Fourier Transform (STFT) to obtain its time-frequency representation, and then comparing the two signals in this new domain using a variety of metrics. One or many mapping or transformation functions are then derived based on the particular metric and applied to modify the STFT's of the input signals. After the modification has been performed, the modified transforms are inverted to synthesize the new signals.
FIG. 1 is a block diagram illustrating how upmixing is accomplished in one embodiment. Left and right channel signals are processed by STFT blocks 102 and 104 . Processor 106 unmixes the signals and then upmixes the signals into a greater number of channels than the two input channels. Four output channels are shown for the purpose of illustration. Inverse STFT blocks 112 , 114 , 116 , and 118 convert the signal for each channel back to the time domain.
Ambience Information Extraction and Signal Synthesis
In this section we describe a technique to extract the ambience of a stereo recording. The method is based on the assumption that the reverberation component of the recording, which carries the ambience information, is uncorrelated if we compare the left and right channels. This assumption is in general valid for most stereo recordings. The studio mix is intentionally made in this way so as to increase the perceived spaciousness. Live mixes sample the sound field at different spatial locations, thus capturing partially correlated room responses. The technique essentially attempts to separate the time-frequency elements of the signals which are uncorrelated between left and right channels from the direct-path components (i.e. those that are maximally correlated), and generates two signals which contain most of the ambience information for each channel. As we describe later, these ambience signals are sent to the rear channels in the direct/ambient up-mix system.
Our ambience extraction method utilizes the concept that, in the short-time Fourier Transform (STFT) domain, the correlation between left and right channels across frequency bands will be high in time-frequency regions where the direct component is dominant, and low in regions dominated by the reverberation tails. Let us first denote the STFT's of the left s L (t) and right s R (t) stereo signals as s L (m,k) and s R (m,k) respectively, where m is the short-time index and k is the frequency index. We define the following short-time statistics
Φ LL ( m,k )=Σ S L ( n,k ). S L *( n,k ), (1a)
Φ RR ( m,k )=Σ S R ( n,k ). S R *( n,k ), (1b)
Φ LR ( m,k )=Σ S L ( n,k ). S R *( n,k ), (1c)
where the sum is carried over a given time interval n (to be defined later) and * denotes complex conjugation. Using these statistical quantities we define the inter-channel short-time coherence function as
Φ( m,k )=|Φ LR ( m,k )|.[Φ LL ( m,k ).Φ RR ( m,k )] −1/2 . (2)
The coherence function Φ(m,k) is real and will have values close to one in time-frequency regions where the direct path is dominant, even if the signal is amplitude-panned to one side. In this respect, the coherence function is more useful than a correlation function. The coherence function will be close to zero in regions dominated by the reverberation tails, which are assumed to have low correlation between channels. In cases where the signal is panned in phase and amplitude, such as in the live recording technique, the coherence function will also be close to one in direct-path regions as long as the window duration of the STFT is longer than the time delay between microphones.
Audio signals are in general non-stationary. For this reason the short-time statistics and consequently the coherence function will change with time. To track the changes of the signal we introduce a forgetting factor λ in the computation of the cross-correlation functions, thus in practice the statistics in (1) are computed as:
Φ ij ( m,k )=λΦ ij ( m− 1 ,k )+(1−λ) S i ( m,k ). S j *( m,k ). (3)
Given the properties of the coherence function (2), one way of extracting the ambience of the stereo recording would be to multiply the left and right channel STFTs by 1−Φ(m,k) and to reconstruct (by inverse STFT) the two time domain ambience signals a L (t) and a R (t) from these modified transforms. A more general form that we propose is to weigh the channel STFT's with a non-linear function of the short-time coherence, i.e.
A L ( m,k )= S L ( m,k ) M [Φ( m,k )] (4a)
A R ( m,k )= S R ( m,k ) M [Φ( m,k )], (4b)
where A L (m,k) and A R (m,k) are the modified, or ambience transforms. The behavior of the non-linear function M that we desire is one in which the low coherence values are not modified and high coherence values above some threshold are heavily attenuated to remove the direct path component. Additionally, the function should be smooth to avoid artifacts. One function that presents this behavior is the hyperbolic tangent, thus we define M as:
M [Φ( m,k )]=0.5(μ max −μ min )tan h {σπ(Φ o −Φ( m,k ))}+0.5(μ max +μ min ) (5)
where the parameters μ max and μ min define the range of the output, Φ o is the threshold and σ controls the slope of the function. In general the value of μ max is set to one since we do not wish to enhance the non-coherent regions (though this could be useful in other contexts). The value Of μ min determines the floor of the function and it is important that this parameter is set to a small value greater than zero to avoid spectral-subtraction-like artifacts.
FIG. 2 is a block diagram illustrating the ambience signal extraction method. The inputs to the system are the left and right channel signals of the stereo recording, which are first transformed into the short-time frequency domain by STFT blocks 202 and 204 . The parameters of the STFT are the window length N, the transform size K and the stride length L. The coherence function is estimated in block 206 and mapped to generate the multiplication coefficients that modify the short-time transforms in block 208 . The coefficients are applied in multipliers 210 and 212 . After modification, the time domain ambience signals are synthesized by applying the inverse short-time transform (ISTFT) in blocks 214 and 216 . Illustrated below are values of the different parameters used in one embodiment in the context of a 2-to-5 multi-channel system.
Panning Information Estimation
In this section we describe another metric used to compare the two stereo signals. This metric allows us to estimate the panning coefficients, via a panning index, of the different sources in the stereo mix. Let us start by defining our signal model. We assume that the stereo recording consists of multiple sources that are panned in amplitude. The stereo signal with N s amplitude-panned sources can be written as
s L ( t )=Σ i (1−α i ) s i ( t ) and s R ( t )=Σ i α i s i ( t ), for i= 1 , . . . , N s . (6)
where α i are the panning coefficients. Since the time domain signals corresponding to the sources overlap in amplitude, it is very difficult (if not impossible) to determine which portions of the signal correspond to a given source, not to mention the difficulty in estimating the corresponding panning coefficients. However, if we transform the signals using the STFT, we can look at the signals in different frequencies at different instants in time thus making the task of estimating the panning coefficients less difficult.
Again, the channel signals are compared in the STFT domain as in the method described above for ambience extraction, but now using an instantaneous correlation, or similarity measure. The proposed short-time similarity can be written as
Ψ( m,k )=2 |S L ( m,k ). S R *( m,k )|[| S L ( m,k )| 2 +|S R ( m,k )| 2 ] −1 , (7)
we also define two partial similarity functions that will become useful later on:
Ψ L ( m,k )=| S L ( m,k ). S R *( m,k )|.| S L ( m,k )| −2 (7a)
Ψ R ( m,k )=| S R ( m,k ). S L *( m,k )|.| S R ( m,k )| −2 . (7b)
The similarity in (7) has the following important properties. If we assume that only one amplitude-panned source is present, then the function will have a value proportional to the panning coefficient at those time/frequency regions where the source has some energy, i.e.
Ψ( m,k )=2 |αS ( m,k ).(1−α) S *( m,k )|[|α S ( m,k )| 2 +|(1−α) S ( m,k )| 2 ] −1 ,
=2(α−α 2 )(α 2 +(1−α) 2 ) −1 .
If the source is center-panned (α=0.5), then the function will attain its maximum value of one, and if the source is panned completely to one side, the function will attain its minimum value of zero. In other words, the function is bounded. Given its properties, this function allows us to identify and separate time-frequency regions with similar panning coefficients. For example, by segregating time-frequency bins with a given similarity value we can generate a new short-time transform, which upon reconstruction will produce a time domain signal with an individual source (if only one source was panned in that location).
FIG. 3A is a plot of this panning function as a function of α. Notice that given the quadratic dependence on α, the function Ψ(m,k) is multi-valued and symmetrical about 0.5. That is, if a source is panned say at α=0.2, then the similarity function will have a value of Ψ=0.47, but a source panned at α=0.8 will have the same similarity value.
While this ambiguity might appear to be a disadvantage for source localization and segregation, it can easily be resolved using the difference between the partial similarity measures in (7). The difference is computed simply as
D ( m,k )=Ψ L ( m,k )−Ψ R ( m,k ), (8)
and we notice that time-frequency regions with positive values of D(m,k) correspond to signals panned to the left (i.e. α<0.5), and negative values correspond to signals panned to the right (i.e. α>0.5). Regions with zero value correspond to non-overlapping regions of signals panned to the center. Thus we can define an ambiguity-resolving function as
D ′( m,k )=1 if D ( m,k )>0 for all m and k (9)
and
D ′( m,k )=−1 if D ( m,k )<=0 for all m and k.
Shifting and multiplying the similarity function by D′(m,k) we obtain a new metric, which is anti-symmetrical, still bounded but whose values now vary from one to minus one as a function of the panning coefficient, i.e.
Γ( m,k )=[1−Ψ( m,k )]. D ′( m,k ), (10)
FIG. 3B is a plot of this panning function as a function of α. In the following sections we describe the application of the short-time similarity and panning index to up-mix (re-panning), un-mix (separation) and source identification (localization). Notice that given a panning index we can obtain the corresponding panning coefficient given the one-to-one correspondence of the functions.
Two-Channel to N-Channel Up-mix
Here we describe the application of the panning index to the problem of up-mixing a stereo signal composed of amplitude-panned sources, into an N-channel signal. We focus on the particular case of two-to-three channel up-mix for illustration purposes, with the understanding that the method can easily be extended to more than three channels. The two-to-three channel up-mix case is also relevant to the design example of the two-to-five channel system described below.
In a stereo mix it is common that one featured vocalist or soloist is panned to the center. The intention of the sound engineer doing the mix is to create the auditory impression that the soloist is in the center of the stage. However, in a two-loudspeaker reproduction set up, the listener needs to be positioned exactly between the loudspeakers (sweet spot) to perceive the intended auditory image. If the listener moves closer to one of the loudspeakers, the percept is destroyed due to the precedence effect, and the image collapses towards the direction of the loudspeaker. For this reason (among others) a center channel containing the dialogue is used in movie theatres, so that the audience sitting towards either side of the room can still associate the dialogue with the image on the screen. In fact most of the popular home multi-channel formats like 5.1 Surround now include a center channel to deal with this problem. If the sound engineer had had the option to use a center channel, he or she would have probably panned (or sent) the soloist or dialogue exclusively to this channel. Moreover, not only the center-panned signal collapses for off-axis listeners. Sources panned primarily toward on side (far from the listener) might appear to be panned toward the opposite side (closer to the listener). The sound engineer could have also avoided this by panning among the three channels, for example by panning between center and left-front channels all the sources with spatial locations on the left hemisphere, and panning between center and right-front channels all sources with locations toward the right.
To re-pan or up-mix a stereo recording among three channels we first generate two new signal pairs from the stereo signal. FIG. 4 is a block diagram illustrating a two-to-three channel upmix system. The first pair, s LF (t) and s LC (t), is obtained by identifying and extracting the time-frequency regions corresponding to signals panned to the left (α<0.5) and modifying their amplitudes according to a mapping function M L that depends on the location of the loudspeakers. The mapping function should guarantee that the perceived location of the sources is preserved when the pair is played over the left and center loudspeakers. The second pair, s RC (t) and s RF (t), is obtained in the same way for the sources panned to the right. The center channel is obtained by adding the signals s LC (t) and s RC (t). In this way, sources originally panned to the left will have components only in the s LF (t) and s C (t) channels and sources originally panned to the right will have components only in the s C (t) and S RF (t) channels, thus creating a more stable image for off-axis listening. All sources panned to the center will be sent exclusively to the s C (t) channel as desired. The main challenge is to derive the mapping functions M L and M R such that a listener at the sweet spot will not perceive the difference between stereo and three-channel playback. In the next sections we derive these functions based on the theory of localization of amplitude panned sources.
FIG. 5 is a diagram illustrating a coordinate convention for a typical stereo setup. The perceived location of a “virtual” source S=[xy] T is determined by the panning gains g L =(1−α) and g R =α, and the position of the loudspeakers relative to the listener, which are defined by vectors S L =[x L y L ] T and S R =[x R y R ] T . FIG. 6 is a diagram illustrating a coordinate convention for a typical stereo setup. At low frequencies (f<700 Hz) the perceived location is obtained by vector addition as [6]:
s=βS.g
where
S=[s L s R ] T
and
g=[g L g R ] T
The scalar β=(g T u) −1 with u=[11] T , is introduced for normalization purposes and it is generally assumed to be unity for a stereo recording, i.e. g L =1−g R . At high frequencies (f>700 Hz) the apparent or perceived location of the source is determined by adding the intensity vectors generated by each loudspeaker (as opposed to amplitude vectors). The intensity vector is computed as
s=γS.q
where
q=[g L 2 g R 2 ] T
and the scalar γ=(q T u) −1 is introduced for power normalization purposes. Notice that there is a discrepancy in the perceived location in different frequency ranges.
FIG. 6 is a diagram illustrating an up-mix technique based on a re-panning concept. The right loudspeaker is moved to the center location s c . In order to preserve the apparent location of the virtual source, i.e. s=s′, the new panning coefficients g′ need to be computed. If we write the new virtual source position at low frequencies, as
s′=S′.g′
where
S′=[s L s c ] T
and
g′=[g L ′g LC ] T
then the new panning coefficients are easily found by solving the following equation:
S.g=S′.g′.
If the angle between loudspeakers is not zero, then the solution to this equation exists and the new panning coefficients are found as
g ′=( S ′) −1 S.g.
Notice that these gains do not necessarily add to one, thus a normalization factor β′=(g′ T u) −1 needs to be introduced. Similarly, at high frequencies we obtain
q ′=( S ′) −1 S.q,
where
q′=[g L ′2 g LC 2 ] T ,
and the power normalization factor is computed as γ=(q′ T u) −1 .
The re-panning algorithm then consists of computing the desired gains and modifying the original signals accordingly. For sources panned to the right, the same re-panning strategy applies, where the loudspeaker on the left is moved to the center.
In practice we do not have knowledge of the location (or panning coefficients) of the different sources in a stereo recording. Thus, the re-panning procedure needs to be applied blindly for all possible source locations. This is accomplished by identifying time-frequency bins that correspond to a given location by using the panning index Γ(m,k), and then modifying their amplitudes according to a mapping function derived from the re-panning technique described in the previous section.
We identify four time-frequency regions that, after modification, will be used to generate the four output signals s LF (t), s LC (t), s RC (t) and s RF (t) as shown in FIG. 4 . Let us define two short-time functions Γ L (m,k) and Γ R (m,k) as
Γ L ( m,k )=1 for Γ( m,k )<0, and Γ L ( m,k )=0 for Γ( m,k )>=0
Γ R ( m,k )=1 for Γ( m,k )>=0, and Γ R ( m,k )=0 for Γ( m,k )<0,
The four regions are then defined as:
S LL ( m,k )= S L ( m,k )Γ L ( m,k )
S LR ( m,k )= S R ( m,k )Γ L ( m,k )
S RL ( m,k )= S L ( m,k )Γ R ( m,k )
S RR ( m,k )= S R ( m,k )Γ R ( m,k ),
where S L (m,k) and S R (m,k) are the STFT's of the left and right input signals, L and R respectively. The regions S LL and S LR contain the contributions to the left and right channels of the left-panned signals respectively, and the regions S RR and S RL contain the contributions to the right and left channels of the right-panned signals respectively. Each region is multiplied by a modification function M and the output signals are generated by computing the inverse STFT's of these modified regions as:
s LF ( t )=ISTFT{ S LL ( m,k ) M LF ( m,k )}
s LC ( t )=ISTFT{ S LR ( m,k ) M LC ( m,k )}
s RC ( t )=ISTFT{ S RL ( m,k ) M RC ( m,k )}
s RF ( t )=ISTFT{ S RR ( m,k ) M RF ( m,k )}
Thus the modification function in FIG. 4 are such that M L is equal to Γ L (m,k)M LF (m,k) for the left input signals and Γ L (m,k)M LC (m,k) for the right input signal, and similarly for M R . To find the modification functions, we first find the desired gains for all possible input panning coefficients as described above. FIGS. 7A and 7B are plots of the desired gains for each output time frequency region as function of α assuming an angle θ=60°.
The modification functions are simply obtained by computing the ratio between the desired gains and the input gains. FIGS. 7C and 7D are plots of the modification functions. While a value of θ=60° is typical, it is likely that some listener will prefer different setups and the modification functions will greatly depend on this. FIGS. 8A and 8B are plots of the desired gains for θ=30°. FIGS. 8C and 8D are plots of the corresponding modification functions for θ=30°.
Source Un-mix
Here we describe a method for extracting one or more audio streams from a two-channel signal by selecting directions in the stereo image. As we discussed in previous sections, the panning index in (10) can be used to estimate the panning coefficient of an amplitude-panned signal. If multiple panned signals are present in the mix and if we assume that the signals do not overlap significantly in the time-frequency domain, then the Γ(m,k) will have different values in different time-frequency regions corresponding to the panning coefficients of the signals that dominate those regions. Thus, the signals can be separated by grouping the time-frequency regions where Γ(m,k) has a given value and using these regions to synthesize time domain signals.
FIG. 9 is a block diagram illustrating a system for unmixing a stereo signal to extract a signal panned in one direction. For example, to extract the center-panned signal(s) we find all time-frequency regions for which the panning metric is zero and define a function Θ(m,k) that is one for all Γ(m,k)=0, and zero otherwise. We can then synthesize a time domain function by multiplying S L (m,k) and S R (m,k) by Θ(m,k) and applying the ISTFT. The same procedure can be applied to signals panned to other directions.
To avoid artifacts due to abrupt transitions and to account for possible overlap, instead of using a function Θ(m,k) like we described above, we apply a narrow window centered at the panning index value corresponding to the desired panning coefficient. The width of the window is determined based on the desired trade-off between separation and distortion (a wider window will produce smoother transitions but will allow signal components panned near zero to pass).
To illustrate the operation of the un-mixing algorithm we performed the following simulation. We generated a stereo mix by amplitude-panning three sources, a speech signal s 1 (t), an acoustic guitar s 2 (t) and a trumpet s 3 (t) with the following weights:
s L ( t )=0.5 s 1 ( t )+0.7 s 2 ( t )+0.1 s 3 ( t ) and s R ( t )=0.5 s 1 ( t )+0.3 s 2 ( t )+0.9 s 3 ( t ).
We applied a window centered at Γ=0 to extract the center-panned signal, in this case the speech signal, and two windows at Γ=−0.8 and Γ=0.27 (corresponding to α=0.1 and α=0.3) to extract the horn and guitar signals respectively. In this case we know the panning coefficients of the signals that we wish to separate. This scenario corresponds to applications where we wish to extract or separate a signal at a given location. Other applications that require identification of prominent sources are discussed in the next section.
Identification of Prominent Sources
In this section we describe a method for identifying amplitude-panned sources in a stereo mix. In one embodiment, the process is to compute the short-time panning index Γ(m,k) and produce an energy histogram by integrating the energy in time-frequency regions with the same (or similar) panning index value. This can be done in running time to detect the presence of a panned signal at a given time interval, or as an average over the duration of the signal. FIG. 10 is a plot of the average energy from an energy histogram over a period of time as a function of F for a sample signal. The histogram was computed by integrating the energy in both stereo signals for each panning index value from −1 to 1 in 0.01 increments. Notice how the plot shows three very strong peaks at panning index values of Γ=−0.8, 0 and 0.275, which correspond to values of α=0.1, 0.5 and 0.7 respectively.
Once the prominent sources are identified automatically from the peaks in the energy histogram, the techniques described above can be used extract and synthesize signals that consist primarily of the prominent sources.
Multi-Channel Up-mixing System
In this section we describe the application of the ambience extraction and the source up-mixing algorithms to the design of a direct/ambient stereo-to-five channel up-mix system. The idea is to extract the ambience signals from the stereo recording using the ambience extraction technique described above and use them to create the rear or surround signals. Several alternatives for deriving the front channels are described based on applying a combination of the panning techniques described above.
Surround Channels
FIG. 11 is a diagram illustrating an up-mixing system used in one embodiment. The surround tracks are generated by first extracting the ambience signals as shown in FIG. 2 . Two filters G L (z) and G R (z) are then used to filter the ambience signals. These filters are all-pass filters that introduce only phase distortion. The reason for doing this is that we are extracting the ambience from the front channels, thus the surround channels will be correlated with the front channels. This correlation might create undesired phantom images to the sides of the listener.
In one embodiment, the all-pass filters were designed in the time domain following the pseudo-stereophony ideas of Schroeder as described in J. Blauert, “Spatial Hearing.” Hirzel Verlag, Stuttgart, 1974 and implemented in the frequency domain. The left and right filters are different, having complementary group delays. This difference has the effect of increasing the de-correlation between the rear channels. However, this is not essential and the same filter can be applied to both rear channels. Preferably, the phase distortion at low frequencies is kept to a small level to prevent bass thinning.
The rear signals that we are creating are simulating the tracks that were recorded with the rear microphones that collect the ambience at the back of the venue. To further decrease the correlation and to simulate rooms of different sizes, the rear channels are delayed by some amount Δ.
Front Channels
In some embodiments, the front channels are generated with a two-to-three channel up-mix system based on the techniques described above. Many alternatives exist, and we consider one simple alternative as follows.
The simplest configuration to generate the front channels is to derive the center channel using the techniques described above to extract the center-panned signal and sending the residual signals to the left and right channels. FIG. 12 is a diagram of such a front channel upmix configuration. Processing block 1201 represents a short-time modification function that depends on the non-linear mapping of the panning index. The signal reconstruction using the inverse STFT is not shown. This system is capable of producing a stable center channel for off-axis listening, and it preserves the stereo image of the original recording when the listener is at the sweet spot. However, side-panned sources will still collapse if the listener moves off-axis.
System Implementation
The system has been tested with a variety of audio material. The best performance so far has been obtained with the following parameter values:
Parameter
Value
Description
N
1024
STFT window size
K
2048
STFT transform size
L
256
STFT stride size
λ
0.90
Cross-correlation forgetting factor
σ
8.00
Slope of mapping functions M
Φ o
0.15
Breakpoint of mapping function M
μ min
0.05
Floor of mapping functions M
Δ
256
Rear channel delay
N p
15
Number of complex conjugate poles of G(z)
These parameters assume that the audio is sampled at 44.1 kHz. The configuration shown in FIG. 4 is used for the front channel up-mix.
In general, the ambience can be effectively extracted with using the methods described above. The ambience signals contain a very small direct path component at a level of around −25 dB. This residual is difficult to remove without damaging the rest of the signal. However, increasing the aggressiveness of the mapping function (increasing σ and decreasing Φ o and μ min ) can eliminate the direct path component but at the cost of some signal distortion. If μ min is set to zero, spectral-subtraction-like artifacts tend to become apparent.
The parameters above represent a good compromise. While distortion is audible if the rear signals are played individually, the simultaneous playback of the four signals masks the distortion and creates the desired envelopment in the sound field with very high fidelity.
Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing both the process and apparatus of the present invention. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims. | Separating a source in a stereo signal having a left channel and a right channel includes transforming the signal into a short-time transform domain; classifying portions of the signals having similar panning coefficients; segregating a selected one of the classified portions of the signals corresponding to the source; and reconstructing the source from the selected portions of the signals. | 7 |
BACKGROUND OF THE INVENTION
Field of the Industrial Application
The present invention relates to an electrically actuated date-stamping apparatus.
A type of date-stamping system is known from Japanese Patent Disclosure No. 58-211289 which includes an electric motor energized by clock signals at regular time intervals to perform the forward movement of printing belts automatically. In this system, printing belts are driven by an electric motor energized by a clock signals. If each of the printing belts has a smooth backface, it is difficult to make a positive advancement of that printing belts since there is slippage between the smooth backface of the printing belt and the surface of the corresponding pulley. In order to overcome this problem, a proposal is made in the above Patent Disclosure to roughened the backface of each printing belt. However, the roughened backface raises another problem in that an irregularity of density is created in the stamped characters and the characters are deformed.
A system in which printing characters are formed on the peripheral face of a disc formed with a gear wheel at the side of the disc is known from by Japanese Utility Model Disclosure No. 61-180751 and Japanese Patent Disclosure No. 85-233877. Although such a disc-type structure can positively overcome the aforementioned problem, each of the printing discs will necessarily have an increased external diameter when numerals corresponding to the days in one month are formed on the peripheral face of the disc. This will increase the overall size of the date-stamping device, and make it inconvenient to handle.
It is therefore an object of the present invention to provide a date-stamping apparatus in which no slippage results between each of belt-driving wheels and a corresponding endless printing belt.
It is a further an object of the present invention to provide a date-stamping apparatus which avoids any irregularity of density of the stamped characters and any deformation of the stamped characters, even if the character portion of the stamping belt is made from soft, cellular rubber to absorb ink.
It is another object of the present invention to provide a date-stamping apparatus in which, even if an endless printing belt is larger than the conventional belt, whole belt assembly can be easily housed in a compact casing.
SUMMARY OF THE INVENTION
According to the present invention, the above objects can be accomplished by a date-stamping apparatus comprising a casing, a bridge member located at the lower end of the casing, a tension roller located above the casing and forced upwardly, an endless date-printing belt having printing characters on its outside surface and spanned between the bridge member and the tension roller, a date-belt driving wheel located within the casing at a substantially intermediate portion thereof, having a circumferential engagement section co-operating with the belt and being contacted by the outside surface of the belt, and an electric motor intermittently energized by a timing circuit and operatively connected with the belt driving wheel.
In a preferred embodiment of the present invention, the printing characters are made from cellular rubber.
Another preferred embodiment of the present invention includes a time-printing belt and a time-belt driving wheel. The time-belt driving wheel is connected with an electric motor and the belt driving wheel is connected with the time-belt driving wheel through a carrying wheel, which makes the belt driving wheel rotate by an amount corresponding to one day when the time-belt driving wheel is driven by an amount corresponding to 24 hours.
Further objects, features and advantages of the present invention will become apparent from the following DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT and the attached figures of drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view, partially broken away, of a date-stamping apparatus which is one embodiment of the present invention;
FIG. 2 is a side view, partially broken away, of the date-stamping apparatus shown in FIG. 1 as viewed from the right-hand side; and
FIG. 3 is a side view, partially broken away, of the date-stamping apparatus shown in FIG. 1 as viewed from the left-hand side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in connection with an embodiment illustrated in the drawings.
A date-stamping apparatus constructed according to the present invention comprises a casing (1) including a time display section (2) on its front and upper portion. The casing (1) also includes a cover (3) vertically slidably mounted on the casing (1) at its central portion to conceal belt feed wheels which will be described later. The casing (1) further includes a small electric motor (4) energized by clock signals from a timing circuit (5) at regular time intervals, and a reduction mechanism (6) including a plurality of gear wheels operatively connected with the motor (4). The gear wheels in the reduction mechanism (6) are engaged by a gear wheel (4a) in the motor (4). The final gear wheel (6a) in the reduction mechanism (6) is provided with three engaging pawls (7) and three engaging grooves (8). The three engaging pawls (7) are angularly arranged with a spacing of 120 degrees from one another; the three engaging grooves are similarly arranged with a spacing of 120 degrees from one another. When one hour's time has passed one hour, each of the engaging pawls (7) is rotated to engage the corresponding engaging pawl (14a) on a time-printing belt driving wheel (10a) contacted by the external face of a time-printing belt (10). Thus, the time-printing belt driving wheel (10a) will be rotated by one notch corresponding to one hour. Reference numerals (10a), (11a), (12a) and (13a) respectively denote time-printing, day-printing, month-printing and year-printing belt driving wheels which are juxtaposed and journalled within the casing (1).
Each of the belt driving wheels contacts, under pressure, with one side of a corresponding endless belt, e.g., time-printing, day-printing, month-printing and year-printing belts (10), (11), (12) and (13), respectively. Each of the belts is spanned between corresponding tension roller (17) or (18), and a bridge member (9), all of which will be described later. Each of the belt driving wheels (10a), (11a), (12a) and (13a) is provided with twelve engaging pawls (14a), (14b), (14c) and (14d) formed thereon at angular intervals of 30 degrees.
There is further provided a carrying wheel (15) having two-lobed cam (15a) and four-lobed cam (15b) formed therein in a juxtaposed fashion. When the four-lobed cam (15b) is moved through 180 degrees to engage a projection (16) on one of the engaging pawls (14a) of the time-printing belt driving wheel (10a) two times (after twenty-four hours through which the time-printing belt driving wheel (10a) has been rotated completely two times), two-lobed cam (15a) causes the day-printing belt driving wheel (11a) engaged by the printing face of the endless day-printing belt (11) to rotate by one notch. As a result, the endless day-printing belt (11) will be moved forward by one day.
The printing belts 10, 11, 12, 13 are made from cellular material. Absorption of stamping ink by the belts enables the date-stamping apparatus to continue stamping without stamp-pad contact. In another embodiment, only the stamping characters of the belts could be made from cellular material.
Reference numeral (17) designates a tension roller over which the day-printing belt (11) passes. This tension roller (17) is supported at each end of a spring (17a) for vertical fine-movement such that the endless day-printing belt (11) is always tensioned under a given tension. There is another tension roller (18) around which the endless time-printing, month-printing and year-printing belts (10), (12) and (13) are wound. Similarly, the tension roller (18) is supported at each end by a spring (18a) for vertical fine-movement such that a given tension will be always applied to each of the endless printing belts.
In the drawings, furthermore, reference numeral (19) denotes a guide roller around which the endless day-printing belt (11) is wound; (20) a guide roller around which the endless printing belts are wound; (21) a ratchet mechanism for preventing the carrying wheel (15) from being rotated in the backward direction; (22) a ratchet mechanism for preventing the belt driving wheels from being rotated in the backward direction; (23) a spring for biasing the ratchet mechanism (22); (24) a battery; and (25) a platen biased by the spring (25a). The platen (25) includes an opening (25b) through which the printing faces of the endless printing belts can be exposed externally during stamping. Reference numeral (26) designates a switch including a spring-biasing type movable contact (26a) and a stationary contact (26b). The motor (4) continues to be energized until the movable contact (26a) of the switch (26) is engaged by the engaging groove (8) of the final gear wheel (6a) and then disengaged from the stationary contact (26b).
It is now assumed that such a date-stamping apparatus has been set, for example, at 1:00 a.m. on Dec. 1, 1988. As the present time becomes 2:00 a.m., the motor (5) is energized by the timing circuit (5) to cause the engaging pawls (7) on the final gear wheel (6a) of the reduction mechanism (6) to engage the respective engaging pawls (14a) on the time-printing belt feed wheel (10a) around which the endless time-printing belt (10) is wound. Thus, the time-printing belt driving wheel (10a) will be rotated by one notch to move the 2 hour character on the endless time-printing belt (10) to the bottom face of the bridge member (9) whereat the two-hour letter will be displayed. At this time, the movable contact (26a) of the switch (26) engages the engaging groove (8) of the final gear wheel (6a) and then disconnected from the stationary contact (26b) to de-energize the motor (4). After one further hour, the similar cycle is repeated to display the 3 hour character on the endless time-printing belt (10) at the bottom face of the bridge member (9). Since the engaging pawl (14a) of the time-printing belt driving wheel (10a) includes the projection (16) functioned to rotate the four-lobed cam (15b) of the carrying wheel (15) through 90 degrees at twelve o'clock (noon), the two-lobed cam (15a) can be rotated through 180 degrees at the second twelve o'clock (in the next day) to rotate the day-printing belt feed wheel (11a) urged against the printing face of the endless day-printing belt (11) by one notch to forwardly move the endless day-printing belt (11) by an amount corresponding to one day. When one month has passed in such a manner, the cover (3) is opened to expose the belt driving wheels such that the belt driving wheel (14c) urged against the endless month-printing belt (12) can be manually rotated by one notch corresponding to one month.
As will be apparent from the foregoing, the present invention provides a date-stamping apparatus wherein the endless time-printing, day-printing, month-printing and year-printing belts are spanned between a bridge member on the lower portion of the casing and an upper tension roller, each of the endless belts having its external printing face urged against the peripheral engaging face of the corresponding belt driving wheel adapted to drive that endless printing belt and wherein the time-printing belt driving wheel is rotated by an electric motor through a reduction mechanism. Therefore, each of the belt driving wheels can be rotated at lower speed while moving the corresponding endless printing belt. As a result, no slippage will be created between each of the belt driving wheels and the corresponding endless printing belt. Furthermore, this provides another advantage in that the printing face of each of the printing belts can be engaged by one of the corresponding belt driving wheels without any damage. Since the date-stamping apparatus is of the endless belt type, it can use a compact casing. Even if any one of the endless printing belts is larger than the other belts, the whole belt assembly can be easily housed in such a compact casing. Thus, the date-stamping apparatus constructed according to the present invention has an increased practical value by overcoming all the problems of the prior art date-stamping systems. | A date-stamping apparatus having a casing, a bridge member located at the lower end of the casing, a tension roller located above the casing and forced upwardly, an endless date-printing belt having printing letters on its outside surface and spanned between the bridge member and the tension roller, a date-belt driving wheel located within the casing at a substantially intermediate portion. The date of driving wheel has a circumferential engagement section co-operating with the belt and being contacted by the outside surface of the belt, and an electric motor intermittently energized by a timing circuit and operatively connected with the belt-driving wheel, so that stamped date is electrically adjusted. | 1 |
RELATED APPLICATIONS
[0001] This application is based on my patent application GB 1214909.2 of 21 Aug. 2012, which is incorporated by reference.
FIELD OF INVENTION
[0002] Radiant heating and cooling applied to domestic and commercial living and working spaces.
[0003] More specifically, the present invention concerns the use of thermal bridging to improve heat transfer through a number of forms of interior cladding:
Plasterboard Screed Fiberboard Particleboard Oriented Strand Board Plywood Engineered wood flooring Laminate flooring Carpet underlay Tufted carpet and carpet tiles
[0014] Efficient thermal bridging enables the beneficial application of low temperature hydronic radiant systems (LTRHS).
BACKGROUND OF INVENTION
Cited Patents
DE7408063, 1974: Bosch
EP0133631, 1983: Evans
EP0089012, 1983: Wenger
DE3511510, 1986: Wenger
DE3710060, 1987: Wenger
DE3211970, 1983: Pirchl
DE2535522, 1975: Pruefling
DE2538830, 1977: Hahn
DE2621938, 1977: Hahn
NL1034848, 2007: Senden
US59311381, 1997: Fiedrich
US2010/0313504: Li
US2012/0301727: Chul et al
US2013/0099013: Asmussen
Energy Saving
[0015] The invention disclosed here applies thermal bridging to reduce the temperature drop across multiple forms of interior cladding. This enables the use of low-temperature radiant heating systems (LTRHS) (and high temperature radiant cooling systems), thereby:
improving efficiency of energy use in heating and cooling living spaces. enabling efficient use of renewable heat sources.
[0018] In both instances, there is an associated reduction in carbon emissions.
[0019] Energy saving in residential and commercial space heating is a significant opportunity since space heating is a large component of total national energy use. For example, in the US, such space heating is around 12% of total energy use. In the UK the equivalent figure is approximately 18%.
Choice of Radiant Systems and Cladding
[0020] Additionally, the invention enables a wider choice of radiant systems for living spaces and of cladding systems for living spaces, where cladding means any individual layers or laminated multiple layers of material installed on or in the interior floor, wall or ceiling, including layers that are load-bearing, insulating, protective or decorative. Living spaces include all spaces both domestic and commercial that are heated or cooled for human or animal comfort.
Benefits of LTHRS
[0021] The efficiency of space heating can be improved by using a low-temperature hydronic radiant system (LTHRS). A similar radiant system can be adapted to cooling.
[0022] A LTHRS delivers heat using surface temperatures typically between 21 and 25 degrees C. and using large radiant areas: usually floor, wall or ceiling surfaces.
[0023] The energy-saving benefits of a LTHRS are:
Boiler efficiency raised by around 25%. The low temperature of return water allows effective recovery of heat from the exhaust gases of a condensing boiler, especially the latent heat of condensing water vapor. Efficient use of a heat pump. A heat pump moves heat from a lower temperature renewable heat source (such as the ground, the air or a pond: all indirect sources of solar heat) to a higher temperature destination. The amount of electricity required to deliver a given quantity of heat by electrical resistive heating divided by the amount of electricity required to drive the heat pump to deliver the same quantity of heat is called the Coefficient of Performance (COP). The COP of a pump falls as the difference in temperature between heat source and heat destination rises. For example, if the heat source is ground at 5 degrees C. and the destination is a LTHRS with water at 35 degrees C., then a typical modern heat pump COP is around 4. The COP for a heat destination at say 70 degrees C.—a temperature typical of conventional wall radiator panels—is around 2 ie the efficiency gain from using a LTHRS is 100%. Every degree reduction in temperature of operation of a LTHRS improves heat pump efficiency by around 3%. Efficient use of solar thermal heating. Modern evaporative solar thermal systems can deliver and store water at 30-40 degrees C. even in winter with outside temperatures as low as minus 8 degrees C. Water at these temperatures can be used in a LTHRS without supplementary heating. Efficient use of waste heat and geothermal heat. Low temperature waste heat and geothermal heat can be used in a LTHRS. Efficient control. A LTHRS can be configured to have low thermal mass, enabling it to be controlled to be responsive to varying outside temperatures. The estimated efficiency improvement compared with high thermal mass systems is around 5%. Efficient provision of comfort. The floor to ceiling temperature profile achieved by an under-floor LTHRS is almost ideal for comfort. By contrast, the same profile for a conventional wall radiator system is inferior, with much heat carried by convection to upper levels of the living space. As a result, a LTHRS can deliver greater comfort at a lower temperature, with consequent energy savings estimated to be 2-5%.
[0036] The ‘ideal’ temperature profile of the heated space that is achievable with under-floor heating does not mean that heating embedded in the ceiling or wall is less preferable. For example, in many living spaces, the ceiling is the largest uncluttered surface and can, in principle, provide even radiant heating for the entire space. Radiant heating in the ceiling acts on the human body in the same way that the body is acted upon by radiant heat from the sky outdoors.
Types of LTHRS
[0037] Currently available LTHRS used in space heating fall into two groups:
Wet systems that involve burying heating pipes in some setting material: a wet screed, usually based on hydrates of calcium sulphate or calcium silicate. Wet systems are limited to floors and walls. In a typical installation on a ground floor, the floor is first covered with dense plastic foam insulation and the edges are sealed with an upright tape that serves as the containing rim for the poured setting material. Using a clipping or guiding system, one or more flexible plastic pipes made of cross-linked high-density polythene (PEX tube) are placed in a continuous serpentine on the insulation and then covered with the setting material. This method is widely used. If wet screed is used on upper floors, the additional structural loads involved must be dealt with. The thermal resistance of the screed helps to provide uniform heating across the floor but raises the water temperature required by several degrees C. compared with the best of the dry systems (see below). The thermal mass of the screed causes inefficiency of control. Dry systems that carry and cover heating pipes using panels of solid material. Almost all modern dry systems use PEX tube arranged in a serpentine. Such systems can be used in floors, walls and ceilings. The most common installation in domestic living spaces is in the floor. In commercial living spaces, the LTHRS often employs pre-assembled panels suspended from the ceiling.
[0040] The main varieties of dry LTHRS for under-floor heating are:
Under-subfloor systems in which PEX tube is attached to the underside of a subfloor (which may be timber planks or particleboard or similar) and between joists. Aluminum plates or ‘heat-spreaders’ are attached to the pipes and insulation is attached under the pipes. Modular panels can also be fitted between the joists. The panel bears channels that grip the PEX tube. This method is convenient for adding radiant heating to an existing building but requires operation at relatively high temperatures to drive heat through the subfloor. Floating floor systems in which PEX tube is attached to panels that sit on the existing subfloor. The panels are insulating, being made of engineered wood (plywood, strand board or particleboard) or dense foam polystyrene or similar. Again, the panels bear channels that grip the PEX tube and are of sufficient depth for further layers of floor to be directly laid on the panel. This type of LTHRS is suited both to new construction and to renovation. Integrated systems in which the insulating panel also functions as the load-bearing subfloor.
Reducing the Temperature Drop in the Radiant Thermal Path
[0044] In order for the LTHRS to run at the lowest possible water temperature, the temperature drop from hot water to radiant surface must be as small as possible.
[0045] The main elements of the thermal path of a typical under-floor LTHRS are, in sequence:
Water PEX tube wall Heat spreader (usually aluminum plate or foil) Subfloor Screed Floor underlay Floor board or tile Carpet or rug underlay Carpet or rug
[0055] Some of these elements may be absent. For example:
A heat-spreader may not be used if the tube is embedded in screed. Subfloor is not on the thermal path if the heating tubes are installed above the subfloor. Screed is used in wet systems and omitted in dry systems. Carpets, rugs and associated underlays may not be present.
[0060] A similar, and simpler list can be constructed for a heating or cooling system that is placed in the wall or ceiling. This list may include plasterboard, for example.
[0061] The present invention is not directly concerned with the temperature drop across water, tube wall and the heat spreader adjacent to the tube.
[0062] The general equation for each of the remaining elements is:
1. F=QA 2. Q=K×delta T/W 3. delta T=QW/K or FW/KA
where:
F=the total heat flow, watts
Q=heat flow rate, watts/m 2
A=area perpendicular to heat flow, m 2
K=thermal conductivity, watts/m ° C.
delta T=the temperature drop across the element, ° C.
W=the width of the element (length of thermal path), m
[0066] In a space-heating application, F is the total heat flow required to compensate for heat loss, which is determined by the exterior insulation of the space and the difference between interior and exterior temperatures. A modern well-insulated home with double-glazing will have a peak annual heat loss rate of Q=50-60 watts/m 2 of floor area. A typical older home in a moderate climate (like the UK) has a peak annual heat loss rate of Q=70-90 watts/m 2 . These are average figures. A room with a large window area and high ceilings may require Q=100 watts/m 2 .
[0067] From equation 3, we can reduce delta T by:
Reducing F This can be done by improving insulation. But all materials are thermally conductive, there are radiation losses from windows and there will be heat losses due to air exchange with the exterior. Reducing W There are limits to how far W can be reduced, usually because of mechanical properties (an element that is too thin will crack, leak, break or wear too quickly and so on). For example, the minimum recommended value of W for a wet screed over under-floor heating is around 30 mm. As another example, the minimum thickness of ceramic floor tile is around 5 mm (porcelain on a very stable underlay). Increasing A This can be done by extending the heated radiant area in the floor, walls or ceiling. This extension is enabled by the present invention which permits standard cladding used in walls and ceilings to be used as radiant surfaces. Increasing K For example, granite or marble tile has a thermal conductivity up to 4× higher than standard ceramic tile and up to 20× higher than wood. Therefore, putting other criteria to one side, a sole objective of efficient under-floor radiant heating implies a preference for granite or marble floors. In an example, a resilient and sound-absorbing flooring underlay may be made of a rubber compound. By selecting polyurethane rubber rather than natural rubber, K is doubled. K can also be increased by using a composite material. For example, the conductivity of tiles can be increased by adding alumina. In a reported case, 20% by weight of alumina raised conductivity by 50%. A rubber/carbon composition with around 20% by weight of carbon powder is reported to improve conductivity three-fold. Evans et al in EP0133631, filed in 1983, describe how the thermal conductivity of screed above under-floor heating pipes can be improved by using a combination of resin, fiber and sand. However, the conductivity of such composites is always dominated by the least conductive constituent. As an example, the thermal conductivity of rubber with almost 90% by volume of aluminum powder is 100× less than the conductivity of the pure metal.
[0081] The effective value of K can also be increased by thermal bridging. This method overcomes the limitations just mentioned and can be applied with significant effect to most forms of interior cladding. It is the subject of the present invention and is discussed further below.
Thermal Bridging
[0082] Thermal bridging refers to the bypassing of an insulating layer by a heat-conducting element or thermal shunt. Conventionally, thermal bridging in building construction derives from an error in design or construction, leading to loss of heat from the building: it is to be avoided.
[0083] The present invention applies thermal bridging to any interior cladding that lies on the thermal path of a radiant heating or cooling system.
Thermal Bridging Defined
[0084] In the present invention, thermal bridging always involves three elements:
The thermal shunt: one or more heat-conducting components that are aligned with the radiant thermal path and that penetrate the cladding. On the heat absorbing side of the cladding, a heat-collecting layer aligned with the cladding, with this layer thermally connected to the thermal shunt. On the heat emitting side of the cladding, a heat-dispersing layer aligned with the cladding, with this layer thermally connected to the thermal shunt.
Thermal Bridge Geometry
[0088] The ideal thermal shunt provides a thermal path through the cladding that is as short as possible ie it traverses the cladding at right angles to the plane of the cladding. It follows that the preferred geometry of a thermal bridge across cladding is rectangular.
[0089] The average thermal path through the entire thermal bridge should also be as short as possible. This means that a preferred configuration of thermal shunt is as a uniform array of elements that is perpendicular to the plane of the cladding, so spreading the thermal load on the heat-collecting layer and on the heat-dispersing layer.
Relative Levels of Thermal Conductivity
[0090] The material of a thermal bridge is always of higher conductivity than the material of the cladding.
[0091] The definition of high and low thermal conductivity is both absolute and relative. There is agreement that materials of low thermal conductivity—usually called insulators—include materials such as foam polyurethane, felt, cork and softwood. The thermal conductivities of these insulators are, respectively, K=0.03, 0.04, 0.07 and 0.12 watts/m° C. There is also general agreement that materials of high thermal conductivity include metals such as stainless steel, iron, aluminum and copper, with thermal conductivities that are, respectively, K=16, 55, 240 and 400 watts/m° C. It is evident that metals can be used for effective thermal bridges across cladding made of insulating material.
[0092] However there is also a range of materials used in cladding that have thermal conductivities with values that lie between the conductivities of obvious insulators and of metals. In such cases, and in general, it is useful to consider the ratio of the thermal conductivity of the bridge to the thermal conductivity of the cladding. As an example, standard tile porcelain (K=1.3 watts/m° C.) is ten times as conductive as most soft woods. Therefore, in principle, a relatively small volume of tile porcelain (say 10% of the volume of the wood) can significantly reduce the temperature drop across softwood for a given rate of heat transfer and so can be a practical material for a thermal bridge across softwood. However, standard tile porcelain is only five times as conductive as dense plasterboard (K=0.24 m° C.) and is therefore a questionable material for a thermal bridge across such cladding.
[0093] Cladding as defined here can be a multi-layer laminate. In general, each layer in such cladding has its own value of thermal conductivity. In this case, the thermal conductivity relevant to thermal bridging of the cladding is the effective conductivity across all layers.
The Need for Heat Collecting/Dispersing Layers
[0094] The need for heat-collecting and heat-dispersing layers in addition to thermal shunts is easily shown by considering a shunt comprising a material with relatively high thermal conductivity (say copper with K=400 watts/m° C.) traversing a thermally insulating cladding (say softwood with K=0.12 watts/m° C.). In this case, copper can conduct the same flow of heat over the same temperature drop as the softwood cladding with a cross-section that is only 100×0.12/400=0.03% of the cladding area. So for a given heat flow, such a thermal shunt can in principle halve the temperature drop across the cladding. But if the thermal shunt is perpendicular to the cladding surface this also means that only 0.03% of the cladding surface is highly conductive. As a result the average radiant thermal path is through the relatively insulating surface of the cladding and the average temperature drop across the cladding is hardly affected by the shunt.
Reducing Thermal Contact Resistance
[0095] Thermal contact resistance in any joins between the shunt and the heat-collecting layer and between the shunt and the heat-dispersing layer should be reduced to a minimum. Contact resistance is preferably eliminated by making the three elements of the thermal bridge—the thermal shunt, the heat-collecting layer and the heat-dispersing layer—out of the same continuous piece of material. Alternatively contact resistance can be kept to a minimum by constructing the thermal bridge from elements of the same malleable conductive material and forcing the three elements together so as to effectively bond together without gaps, preferably with a bonding agent.
[0096] Thermal contact resistance between abutting metal parts can be very high and is due to air gaps, which can be present at a microscopic level. Contact resistance is reduced by:
Exact fit of parts, for example, perfectly flat plate to perfectly flat plate. Smooth surfaces. High contact pressure. Experiments show that contact resistance between bare metal plates falls as contact pressure rises and falls to zero when cold welding pressure is reached. A flowing filler or bonding agent: this fills the air gaps. To reduce resistance across the bond line, the bond line should be as thin as possible. For a given contact pressure, a filler can reduce contact resistance between flat metal plates by a factor of up to 20.
[0101] By bonding aluminum to aluminum under pressure, contact resistance can be reduced to the point that a thermal bridge so constructed may be considered to be effectively seamless.
Effect of Thermal Bridge on Temperature Drop
[0102] Assuming a complete thermal bridge with no or negligible contact resistance, the effect of the bridge on temperature drop across the cladding can be calculated as follows:
[0103] For parallel thermal resistances, in units of ° C./watt:
[0000] 1/ R= 1/ R 1 +1/ R 2 4.
Where:
[0104] R is the combined resistance of cladding and thermal shunt
R 1 is the resistance of the cladding
R 2 is the resistance of the thermal shunt
[0105] Obviously, for a given rate of heat transfer (watts), the temperature drop varies with R.
[0106] In the copper/softwood example given above, the reduction in temperature drop across the cladding for different cross-sections of thermal shunt as % of cladding planar area can be calculated:
[0000] 0.03% area of thermal shunt results in R 2 =R 1 so that from 4:
1/R=2/R 1 or R=R 1 /2 ie the temperature drop across the cladding is reduced by 50%
0.06% area of shunt results in R 2 =R 1 /2 so that from 4:
1/R=3/R 1 ie the temperature drop across the cladding is reduced by 66%
0.12% area of shunt results in R 2 =R 1 /4 so that from 4:
1/R=5/R 1 ie the temperature drop across the cladding is reduced by 80%
[0107] This is a striking result: small quantities (by volume) of highly conductive material can, in principle, significantly reduce the temperature drop across an insulator. However, these figures underestimate the quantity of heat-conducting material required because the volumes of the heat-collecting layer and the heat-dispersing layer are omitted. The temperature drop is also an overestimate because the temperature drop along the average thermal path through the heat-conducting layers on each side of the cladding is omitted.
[0108] The volume of these layers as a % of total cladding volume partly depends on the thickness of the cladding: the thicker the cladding the smaller this % becomes. The temperature drop along the average thermal path partly depends on the distance between adjacent elements of the thermal shunt.
[0109] In an example, the cladding is 20 mm thick, the layers on each side of the cladding are 0.1 mm thick (this is 10× thicker than standard kitchen aluminum foil). The volume of layers as a % of cladding volume is 100×2×0.01/20=1%. This figure must be added to the shunt % area figures given above.
[0110] In an example, the planar distance between uniformly distributed elements of the thermal shunt is 20 mm. The maximum distance travelled by heat dispersing to or from an element of the thermal shunt is 10 mm. The average distance is approximately 5 mm. If the thermal shunt and the heat collecting/dispersing layers are the same continuous material, then as an equivalent, approximately 5 mm of thermal path is added to each end of the shunt, increasing the resistance of the shunt in this case by (2×5)/20=50%.
[0111] The reduction in temperature drops across the cladding for different volumes of thermal bridge as % of total cladding volume becomes:
[0000] 1.03% volume: 40%
1.06% volume: 57%
1.12% volume: 73%
[0112] In this example, the improvement in temperature drop is almost entirely due to increasing the cross-sectional area of the shunt.
Selecting Material for a Thermal Bridge
[0113] A suitable material for thermal bridging is aluminum of high purity (exceeding 99.6%). This is a soft metal with high thermal conductivity: around 230 watts/m° C. Most aluminum used commercially is in the form of a hard alloy. But typical hard aluminum alloys have thermal conductivities that are 20-40% lower than the pure metal. If thermal bridging does not require the metal to bear structural loads, the soft pure metal is to be preferred.
[0114] Other heat-conducting materials can also be used. Pure copper might seem to be suitable since it has a thermal conductivity that is 74% higher than pure aluminum. However, copper is both 3.3× denser than aluminum and also (in 2012) around 4× more expensive per kg. So the ratio of conductivity to cost per cc compared with aluminum is 1.74/(3.3×4)=0.13.
[0115] The same calculation can be made for cheaper metals. For example, standard carbon steel is half the price per kg of aluminum (in 2012). But it is 2.9× denser and has a thermal conductivity that is only 17% of aluminum. Therefore the ratio of conductivity to cost per cc compared with aluminum is 0.17/(2.9×0.5)=0.12.
[0116] Ceramics with high thermal conductivities such as aluminum nitride, boron nitride, silicon carbide and alumina have significantly lower conductivities than pure aluminum without being sufficiently cheaper. Porcelain is an option that is up to 20× cheaper than aluminum on a volume basis. However, in its standard form, porcelain has a thermal conductivity around 100× less than aluminum so that the ratio of conductivity to cost per cc compared with aluminum=0.2
[0117] The same calculation can be made for graphite. Depending on how this is processed it has widely varying properties. Lightweight expanded graphite has an in-plane thermal conductivity that is around 80% of pure aluminum. Its density relative to aluminum is 0.37 and the price per kg (in 2012) is around 8× higher. The ratio of conductivity to cost per cc compared with aluminum is 0.8/(0.37×8)=0.27.
[0118] Dense graphite sheet can have an in-plane thermal conductivity that is up to 2.6× that of pure aluminum. Its density relative to aluminum is 0.6 and the price per kg (in 2012) is around 10× higher. The ratio of conductivity to cost per cc compared with aluminum is 2.6/(0.6×10)=0.43.
[0119] Advanced graphite foils have in-plane thermal conductivities up to 1500 watts/m° C. or 6.5× the conductivity of pure aluminum. These foils, developed for cooling electronic components, are expensive.
[0120] It is possible that at some future date, carbon compounds will emerge that combine high thermal conductivity with low cost.
[0121] The cheapest heat-conducting constructional material is cement or concrete, which can be up to 30× cheaper than aluminum sheet on a volume basis. The thermal conductivity of these materials can be increased by formulations that reduce porosity and include conductive fillers. For example, inclusion of quartz sand can increase thermal conductivity of concrete up to K=3.5 watts/m° C. or 70× less conductive than aluminum. The ratio of conductivity to cost per cc compared with aluminum is 30/70=0.43.
Improving Emissivity of Aluminum
[0122] The thermal path of a radiant system may include radiant heat transfer between different layers of the system: for example between thermally bridged underlay and thermally bridged carpet. Untreated aluminum has very low emissivity, reflecting up to 97% of radiated heat. Aluminum surfaces engaged in radiant heat transfer in the thermal path of the radiant system should be treated to increase emissivity, for example by anodizing or by dyeing or by painting.
PRIOR ART
[0123] Wenger EP0089012, filed 1983. This is similar to DE3209091, filed 1983. An insulating panel has thermally conductive faces connected by thermal shunts that penetrate the panel. Two examples are given: conductive cylindrical sleeves inserted into holes in the panel and nails or screws penetrating the panel.
Comment
[0124] The combination of heat-collecting layer, heat-dispersing layer and thermal shunt meets the proposed definition of a thermal bridge given above. However this solution is flawed since it wastes material, weakens the panel and is likely to incur significant contact resistance between the shunts and the surface layers.
[0125] Wenger DE3511510, filed 1986. Wenger states that his earlier patent is deficient since it involves boring holes in the insulating panel and inserting relatively expensive metal shapes. He describes a composite panel, for example, particleboard, with upper and lower heat-conducting surfaces: these are thermally connected by conducting sheets that are inserted through an array of pairs of parallel slots cut in the panel. The sheets are folded over to connect thermally with the upper and lower heat-conducting surfaces.
Comment
[0126] This arrangement also qualifies as a thermal bridge. A sheet conductor as a thermal shunt is likely to be significantly cheaper than a shaped insert. However, milling the slots involves material wastage and can weaken the panel. There is still contact resistance between the shunt and the heat-conducting surfaces.
[0127] Wenger DE3710060, filed 1987. A composite insulating panel is constructed from elements wrapped at intervals with conductive sheet and bonded together so that the wrapped sheet is in thermal contact with upper and lower conductive surfaces.
Comment
[0128] This invention reproduces the 1983 invention but avoids the need for cutting slots by cutting an insulating panel into pieces and bonding such pieces together. The use of upper and lower conductive sheets is redundant and therefore an unnecessary cost, both in materials and in manufacturing complexity. There is also an avoidable thermal contact resistance between the upper and lower conductive surfaces and the wrapped sheet. The heat-transfer capacity of the thermal bridge is limited by the number and size of pieces of insulating panel that it is economical to cut up and by the effect on mechanical properties. There is wastage in cutting up the panel and additional expense in cutting it and bonding it back together.
[0129] Pirchl DE3211970, filed 1983. An insulating panel is penetrated by holes each containing an inserted sleeve made of, for example, resin, and inside each sleeve is a heat-conductive material, for example, a ceramic cement. The holes are given conical cross-sections, so that the heat-conducting material also provides a heat spreading and dispersing function. A manufacturing process is also described.
Comment
[0130] Pirchl's invention is similar to Wenger (DE3710060) but inferior. It is a less effective thermal bridge because the heat spreader and diffuser cover only a small fraction of the panel surface: otherwise an amount of original panel would have to be removed that would be a large waste of material and would significantly change the physical properties of the panel, including its load-bearing capability. Also most ceramics are significantly poorer thermal conductors than most metals.
[0131] Pruefling DE2509841, filed 1975. Pruefling describes an underfloor heating system with fast thermal response. A heat-conducting layer is shaped into uniform castellations, with the heated conduit fitted between the castellations. The castellated layer, made for example, of thin steel, has a backing of rigid foamed plastic insulation. Flooring material, for example, carpet, is placed directly on the castellated surface; the conduit is protected from foot traffic by inserts made, for example, of wood fiber.
Comment
[0132] This is not a thermal bridge across an insulating panel; it is an example of a heat spreader that has channels for holding the heating conduit. There are many examples of heat-spreaders without thermal shunts: for example Fiedrich US59311381, Chul US2012/0301727, Asmussen US2013/0099013
[0133] Pruefling DE2535522, filed 1975: The castellated underfloor heating system of DE2553522 is further described. In one version ( FIG. 3 ), dry screed above the heating circuit is penetrated by a corrugated conductive layer.
Comment
[0134] The conductive layer is described as an embossed continuous sheet. This may be suitable for in situ poured flooring where the ‘valleys’ on the upper side of the embossed sheet can be simply filled with screed. But where an insulating panel is pre-manufactured it is a significant advantage for a thermal bridge to have an open structure that enables the material of the panel (for example, plaster or wood composite) to form a coherent connected mass without weakening voids.
[0135] Hahn DE2621938, filed 1977 and Hahn DE2538830/FR2322248, filed 1977.
[0136] Heat transfer across an insulating material such as screed is improved by incorporating conducting powders, granules, grids and preformed inserts.
Comment
[0137] Hahn describes varying the density of particles across the screed.
[0138] He also describes an embedded zig-zag thermally-conductive grid but provides little description. The zig-zag shape shown is not an ideal thermal shunt because it does not provide the shortest thermal path across the insulator. This is not a thermal bridge because there is no heat-collecting layer or heat-dispersing layer connected to the shunt.
[0139] Senden NL1034848, filed 2007. An insulating construction panel includes heat conducting material that conducts heat through the panel. In a first example, fins of conductive material radiate through the panel from a heated conduit on the rear surface of the panel.
Comment
[0140] This does not provide uniform heating to the front of the panel. It does not constitute a complete thermal bridge.
[0141] In a second example, fins of conductive material connect to heat conducting surfaces on the back and front of an insulating panel.
Comment
[0142] This is a complete thermal bridge. The construction of the fins is not explained nor is the connection of shunt and surface layers explained
[0143] In a third example, a composite heating panel is described, comprising a back panel of rigid polystyrene foam; next to this, a layer of aluminum, incorporating a channel carrying a heated conduit; next to this a second layer of rigid foam; next to this a second layer of aluminum; next to this a front panel of plaster. Conductive sheet is wrapped round blocks of the second layer of foam, so providing a thermal shunt.
Comment
[0144] This is a complete thermal bridge across the rigid foam and appears similar to the description in Wenger's last patent (DE3710060). The second aluminum layer is unnecessary and entails unnecessary contact resistance. With a suitable arrangement of the heat source, the first aluminum layer is also unnecessary. The inventor's claims are specific to a thermal bridge across low-density materials with very low thermal conductivity, such as plastic foam. In this third example, the insulating plaster front panel has no thermal bridge.
[0145] Li US 20100313504, filed 2009. Li describes a heated flooring system comprising wooden boards connected by thermally conductive members. Each member comprises a hollow lower section that conducts heat transfer fluid and an upper solid section that locks together adjacent boards and provides a thermal path to the upper surface.
Comment
[0146] This is a poor thermal bridge. The thermal shunt is effective but the upper heat-dispersing surface covers only a small fraction of the floor surface. As a result the heating from the radiant surface is uneven.
[0147] In summary, although relevant invention dates to at least 1974 (Bosch, DE7408063), prior art does not describe radiant thermal bridges for interior cladding that are sufficiently efficient, cost-effective and manufacturable.
Advantages
[0148] The present invention significantly improves on prior art by:
Reducing the temperature drop across common forms of cladding using thermal bridges of high efficiency and low cost. Doing so with minimal material wastage. Doing so with minor modifications to the standard manufacturing and installation processes for such cladding. Doing so without significantly compromising the desired properties of the cladding: for example, strength.
SUMMARY OF INVENTION
[0153] A rigid or pliable interior cladding for the floor, wall or ceiling of a domestic or commercial living space that is part of the thermal path of a radiant heating or cooling system is constructed with thermal bridges: using material of higher thermal conductivity to bypass the thermal resistance of material of lower thermal conductivity.
[0154] The present invention describes the construction of thermal bridges that:
Use the shortest possible thermal shunts ie shunts that are substantively at right angles to the plane of the cladding. Use heat-collecting layers and heat-dispersing layers that are parallel to the cladding surface and on the surface and preferably covering most of the surface. As a consequence of 2 and 3, use thermal bridges of substantively rectangular shape. Use continuous, seamless material for shunt and heat-conducting layers so that contact resistance in the bridges is nil. Otherwise, contacting elements of the bridge are pressed together and bonded in place under significant pressure, where this means at least 50 psi and preferably over 500 psi. Are arranged in a uniform planar array. Are installed in cladding preferably as an integral part of the standard cladding manufacturing process. Have an open structure, meaning a geometry that allows moldable material to flow through a uniform arrangement of gaps in the bridges and so to form a uniform coherent mass that protects the structural integrity of the cladding. Use primarily aluminum for the material of the thermal bridges.
[0163] Corresponding adaptations of standard cladding manufacturing processes are also described.
[0164] The appropriate embodiment of thermal bridging varies with the size of the cladding element, the manufacturing process and the rigidity of the element. For example, plasterboard is a rigid cladding in the form of relatively large panels, constructed by molding. Composite wood panels such as fiberboard and particleboard are molded under high pressure. Timber flooring is an example of rigid cladding in the form of relatively small units (planks) constructed by dividing up larger pieces of material. Carpet underlay is an example of flexible cladding made in large continuous sheets. These claddings are addressed by embodiments of the present invention. In each case the aim is to make the incorporation of a thermal bridge into the cladding an easy adaptation of current manufacturing processes.
[0165] The described embodiments of thermal bridge are:
Honeycomb shunt Rectangular spirals Rectangular loops or rolls Rectangular corrugated mesh Rectangular loop pressed sheet Flapped pressed sheet Arrays of L-shaped flaps Embedded cuboids Wrapped sections Embedded wrapped cuboids Deformed spirals Penetrating pressed sheet Molded bridges Folded conductive thread loops Conductive granules
Plasterboard
[0181] Plasterboard is a common interior cladding for walls and ceilings. It is available in a wide variety of special forms: for example, to resist fire, suppress vibration, block moisture and resist impact. Where a radiant heating or cooling system is operating through a wall or ceiling, plasterboard is an option as a radiant surface.
Advantages
[0182] The advantages of using plasterboard as the radiant surface are:
The radiant surface can be large The radiant surface can be inconspicuous It is a constructional panel that is well-understood and well-accepted. It is mass-produced and therefore cost-effective; the methods describe here require only minor changes to the manufacturing process It is easy to install It allows a wide choice of decorative finishes The methods described here allow normal treatment of the panel such as sawing, nailing, installing electric cabling, hanging pictures and so on.
Properties
[0190] Plasterboard is used in a range of densities and thicknesses. Common thicknesses for walls are 9.5 mm and 12.5 mm. For wide spans on ceilings, 15 mm may be preferred. For sound suppression and fire resistance, the thickness may be up to 25 mm. The thermal conductivity of standard plasterboard is around 0.18 watts/m° C., rising to 0.25 watts/m° C. for high-density board.
Temperature Drop
[0191] From equation 3, the temperature drop across standard 12.5 mm plasterboard for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.0125/0.18=3.5° C. to 7° C.
[0192] This temperature drop makes conventional plasterboard a poor choice for radiant heat transfer.
[0193] Small quantities of aluminum used as a thermal bridge can significantly increase the thermal conductance of plasterboard. For example, high-purity aluminum has a thermal conductivity that is 1280× higher than standard plasterboard. So 1/1280 (=0.08%) by volume of aluminum embedded in a given area of plasterboard could, if combined with heat collecting/dispersing layers, double the rate of heat transfer for a given temperature drop or halve the temperature drop for a given rate of heat transfer. This is possible in principle if an embedded aluminum shunt is used in the form of straight fibers, pins or walls, bridging the board at right angles to the plane of the board and uniformly distributed.
Honeycomb
[0194] In an embodiment of the present invention, a uniform density of perpendicular thermal shunts is achieved by embedding high-purity aluminum honeycomb inside the plasterboard, with the thickness of the honeycomb panel equal to the thickness of the plasterboard panel. Aluminum honeycomb is an affordable solution since it is mass-produced by a simple process from bonded foil, mainly for constructing strong but light composite panels. To improve rigidity, the foil is usually an alloy. Adhesion between the foil and the plaster can be improved by treating the surface of the foil, for example, by abrasion, by anodizing or by phosphating and by adding adhesive polymer to the plaster. Perforations in the foil used to construct the honeycomb allow mechanical bridging of plaster between honeycomb cells.
[0195] Aluminum sheet laminated to each side of the panel is bonded to the honeycomb under pressure. If the aluminum sheet is 0.05 mm thick, say, then, for a 12.5 mm plasterboard these constitute an additional 0.1/12.5=0.8% by volume of the total board.
Trial
[0196] In a trial, commercial honeycomb made of 0.07 mm aluminum alloy foil was embedded in plaster and 0.05 mm high-purity aluminum foil was bonded to each side of the honeycomb using epoxy cement. The honeycomb was 2.4% by weight of the plaster/honeycomb composite, equivalent to 0.6% by volume. The block of plaster/honeycomb composite and an identical block also with facing foil but without the honeycomb were placed on the same heated plate. The heated plate was 5 mm aluminum over a serpentine of constant output resistance wire. The samples were fixed to the plate using mastic and the temperatures were measured using K thermocouples in mastic.
[0197] The temperature drop across the plaster/honeycomb composite was around 70% less than the temperature drop across the same thickness of plaster alone (ie the effective conductivity of the plaster was increased by a factor of 3×).
Manufacture
[0198] Plasterboard is manufactured by grinding and calcining gypsum, mixing the powder with fibers of wood, paper or glass and other additives, adding water, extruding a layer of wet plaster paste on to a lower layer of paper, feeding through rollers with an upper layer of paper, slicing into panels and drying the panels.
[0199] A minor modification of this manufacturing process allows aluminum honeycomb to be embedded in the plaster. The lower and upper layers of paper are replaced or supplemented by flexible heat-conducting materials that act as heat-collector and heat-diffuser. To enable drying of the wet plaster, the material must also be permeable to moisture. In an embodiment, the lower and upper layers are fine paper laminated with inner surfaces of perforated aluminum foil. Metallized or graphitized paper or fabric can also be used. The moving lower layer of perforated aluminum foil is coated with adhesive. Honeycomb panels are fixed to the foil. Wet plaster is poured over the honeycomb. Vibration ensures that the plaster paste fills the honeycomb without voids. The upper layer of perforated foil is also coated with adhesive and is pressed on the top of the honeycomb.
Rectangular Spirals
[0200] In another embodiment of the present invention, rectangular spirals of aluminum wire or strip are embedded side by side in plaster, with the depth of the spirals equal to the thickness of the finished plasterboard.
[0201] The portions of the spiral that span the depth of the plaster serve as a thermal shunt; the outer edges of the spiral serve as heat-collecting and heat-dispersing layers. The thermal shunt is most effective when it is perpendicular to the faces of the plasterboard and heat collecting/dispersing layers are most effective when parallel to the faces of the plasterboard. Therefore the most suitable geometry is rectangular.
Rectangular Loops or Rolls
[0202] In another embodiment, rectangular loops of aluminum wire or strip are constructed by weaving. In effect, the coils of a spiral are displaced at right angles to the spiral axis so that the spiral loops are edge to edge. A parallel series of such loops can be held in place by wires woven at right angles to the loops. In this manner, a linked planar array of rectangular loops is constructed. Alternatively, the rectangular spirals can be replaced by rectangular rolls made of sheets of woven wire or tape or by sheets of expanded mesh or by perforated sheets.
Rectangular Corrugated Mesh
[0203] In another embodiment of the present invention, a roll of flat aluminum mesh is fed into crimping rollers to produce a corrugated mesh with a depth of corrugation equal to the thickness of the finished plasterboard. The corrugated mesh is fed on to the lower layer of paper. The wet plaster paste flows through the mesh and the manufacturing process is completed as already described.
[0204] The walls of the corrugation serve as a thermal shunt and the extremes of the corrugation serve as heat-collecting and heat-dispersing layers. The corrugation can be most effective as a thermal shunt when the wall of the corrugation is perpendicular to the plasterboard. It can be most effective in heat-collection and heat-dispersion when the extremes of the corrugation are aligned with the plasterboard surfaces. These conditions are met by a rectangular corrugation.
Mesh and Expanded Mesh
[0205] A mesh means any material in the form of a sheet covered in a dense uniform array of apertures. A mesh may be made by weaving wire, strip or fiber (there are multiple weave patterns), by twisting wire, by welding wire, by perforation of sheet or by slitting and expanding sheet.
[0206] In its most common form, expanded mesh is made by slitting metal sheet to create a pattern of staggered parallel slits. By stretching the sheet at right angles to the slits, a uniform lattice is formed, comprising curved strands surrounding rhomboidal apertures. The curved strands alternately curve above and below the plane of the mesh. This is called a raised expanded mesh. If this raised mesh is used directly to make a corrugated thermal bridge, the thermal path through the shunt follows the curves of the strands. This thermal path can be made significantly shorter, improving heat transfer, by flattening the mesh, for example by passing the mesh through rollers. Manufacture of such mesh is simple and low cost with negligible material wastage.
Raised Mesh
[0207] A raised expanded mesh can be incorporated directly in a molded panel to form a thermal bridge. The thickness of such raised mesh varies with the length of the slits made before expansion. As an example, a raised aluminum mesh is made with the same thickness as finished plasterboard. The mesh is placed on a paper layer and wet plaster is poured on to the mesh. Due to the open structure of the mesh, plaster fills all the voids between the metal. Manufacture of the plasterboard then continues in the normal way.
Rectangular Loop Pressed Sheet
[0208] In an embodiment of the current invention, rectangular loops are pressed from aluminum sheet. Aluminum sheet is slit into a uniform array of pairs of slits. The sheet between each pair of slits is pressed at right angles to the plane of the sheet so that this portion of sheet is drawn into an open rectangular loop, forming a planar array of rectangular loops seamlessly connected to a planar base. The height of the loops is the same as the thickness of the finished plasterboard. The manufacturing process for this looped pressed sheet is simple and material wastage is insignificant.
[0209] The looped pressed sheet is placed on the plasterboard platform with the loops facing upwards and wet plaster paste is poured around the loops, flowing through the loops, until the top surface of the loops is aligned with the top surface of the wet plaster. The plasterboard manufacturing process is then completed.
[0210] The result is a uniform array of seamless rectangular thermal bridges through the panel.
[0211] If the loops are stretch-formed, then the geometry of the loops is limited by the maximum practical elongation of the aluminum alloy used. This can be up to 25%. The length of a rectangular loop is the length of the pair of slits plus 2× the thickness of the panel. If, for example, the panel is 12 mm thick, then the required length of the slits, L, is given by: 24/L=0.25 or L=at least 96 mm
Flapped Pressed Sheet
[0212] In an embodiment of the current invention, rectangular flaps are pressed from aluminum sheet. Aluminum sheet is slit into a uniform array of pairs of slits and each pair of slits is joined at one end by a cut at right angles to the slits. The result is a cut in a rectangular U-shape. The sheet between each pair of slits is pressed at right angles to the plane of the sheet so that this portion of sheet becomes a vertical flap, so forming a planar array of vertical flaps seamlessly connected to a planar base. The height of the flaps exceeds the thickness of the finished plasterboard. The manufacturing process for this flapped pressed sheet is simple and material wastage is insignificant.
[0213] The flapped pressed sheet is placed on the plasterboard platform with the flaps facing upwards and wet plaster paste is poured around the flaps until the required thickness of paste is achieved. At this point the flaps project vertically from the surface of the paste.
[0214] By moving the paste layer under a roller, the exposed vertical section of each flap is bent over and flattened against the upper surface of plaster. The result is an array of rectangular thermal bridges (each rectangle is of course missing one side). Depending on the orientation of the flapped pressed sheet relative to the roller, each flap and its connecting base sheet forms either a rectangular C-shape or a rectangular S-shape. The plasterboard manufacturing process is then completed.
[0215] As an alternative, the exposed sections of each flap are not bent over until the plaster has set. In this case a more rectangular profile may be achieved, but an adhesive layer must be added to the flaps so that the flaps can be laminated to the surface of the dry plaster.
[0216] The result is a uniform array of seamless rectangular thermal bridges through the panel.
L Shaped Strips
[0217] In an embodiment that closely resembles the use of flapped pressed sheet, L-shaped strips of aluminum mesh or of aluminum sheet or of perforated aluminum sheet are bonded in a uniform array to the lower layer of plasterboard paper before the plaster paste is added. The upright portions of the L-shaped strips are equivalent to the flaps described in the last section.
Embedded Cuboids
[0218] In another embodiment of the present invention, heat-conducting elements with a diameter equal to the thickness of the plasterboard are dispersed in the wet paste.
[0219] Suitable shapes for such an element have open geometries, allowing bridging of plaster across the metal/plaster matrix. Again a rectangular profile is desirable so that a complete thermal bridge is constructed out of continuous heat-conducting material. This can be achieved with, for example, a wire cuboid or a cuboid cylinder. If the cylinder has a square cross-section and is elongate and is wrapped round its circumference with heat-conducting sheet, it will automatically orient itself on a flat platform so that the sheet provides a rectangular thermal path. Shapes can be constructed so that they have asymmetric density (for example, by wrapping a cylinder in 1.5 rotations). These shapes will orient themselves uniformly if vibrated on a tray. To avoid air bubbles inside the shapes, they can be pre-filled with plaster before the main manufacturing process. Spherical heat-conducting shapes can provide a short thermal path regardless of orientation. Possible alternative shapes include a spiral with spherical outline, or a sphere made of wire hoops, or a wire cube or a wire tetrahedron.
[0220] The result is a dispersed array of approximately rectangular seamless thermal bridges.
Wrapped Sections
[0221] In another embodiment, the thermal shunt is added after a plasterboard panel has been made, by wrapping segments of the panel in a heat-conducting layer.
[0222] A heat-conducting layer is wrapped round the edges of the panel and laminated to each side of the panel. In this way, the three elements of the thermal bridge are made out of a continuous piece of material. Standard plasterboard panels are too wide at 0.6 to 1.35 m to be effectively bridged by thermal shunts on the edges of the panel alone. In an embodiment of the present invention this problem is solved by:
Cutting the panel into narrower sections or making narrower sections Wrapping heat-conducting foil round each section and bonding the foil to the plaster Bonding the sections back together.
[0226] In a related embodiment, narrow sections of finished plaster are wrapped in heat-conducting foil and these segments are fed back into the plasterboard manufacturing process. If the foil is spiral or perforated, there is a mechanical bridge between old and new plaster. This is equivalent to the method of embedded pre-filled cuboids described in the previous section.
Other Molded Cladding
[0227] Plasterboard is an example of a cladding produced by molding. The methods described for thermal bridging of plasterboard are applicable to other similar molded cladding: for example, products containing:
Clay, cement or other minerals Wood, bamboo, paper, straw, wool or other natural fibers Rubber or other elastomers Plastics
Screed
[0232] A significant number of radiant heating systems consist of under-floor tubing carrying hot water, with the tubing embedded in a so-called wet screed that is mixed and applied in situ and allowed to set. Wet screed is a setting layer like plasterboard and the thermal bridges applicable to plasterboard are also applicable to screed.
Wet Screed
[0233] Wet screed is usually based on hydrates of calcium sulphate or calcium silicate and typically when set has a thermal conductivity of around K=1.1 watts/m° C. The required depth of screed over the pipes depends on the screed composition—for example, the inclusion of reinforcing fibers—and is between 30 and 40 mm.
Temperature Drop for Wet Screed
[0234] From equation 3: the temperature drop across 40 mm screed for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.040/1.1=2° C. to 4° C. approximately
[0235] By using thermal bridging as described here, this temperature drop can be significantly reduced at low cost.
Rectangular Spirals
[0236] As an example, before pouring the screed, rectangular spirals of aluminum are laid across the heating tubes in a uniform pattern at right angles to the tubes. The spirals have a height equal to the desired depth of screed above the tubes. The spirals can be held in place temporarily by gravity, for example by dense rods arranged inside the spirals. The spirals can also be held in place temporarily by using dabs of tacky adhesive placed on each end of a spiral where it contacts the tubing. Wet screed is then poured over and into the spirals, so that when the screed layer is complete, the upper surface of the spirals is continuous with the upper surface of the screed. The result is a uniform array of seamless rectangular thermal bridges across the screed.
[0237] The spirals can be pre-filled with set screed. The spirals can be substituted by rectangular cylinders of flat aluminum mesh. The spirals can also be substituted by an aluminum mesh that is folded into a planar rectangular corrugation. A suitable mesh is made by flattening expanded aluminum.
Dry Screed
[0238] Wet screed can be substituted by dry screed floor panels. These resemble plasterboard but are load-bearing and so, typically, are reinforced with fibers and used at thicknesses of 30-40 mm. The dry screed panels typically have tongue and groove edges. Commercial dry screed panels have a thermal conductivity of K=0.44 watts/m° C.
Temperature Drop for Dry Screed
[0239] From equation 3, the temperature drop across a 40 mm panel for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.040/1.1 0.44=4.5° C. to 9° C. approximately
[0240] Dry screed panels can be thermally bridged in the same way as plasterboard.
[0000] Molded Cladding with Compression
[0241] Plasterboard is an example of a molded, setting cladding that does not require compression during manufacture. Other forms of molded cladding, including wood composite (or engineered wood) panels—for example, medium-density and high-density fiberboard (MDF and HDF), particleboard and oriented strand board (OSB)—involve compression.
Wood Composite Manufacturing
[0242] The above-named wood composite claddings have similar manufacturing processes: wood particles or pieces are cut, sieved, dried, combined with resin, formed into a mat on a forming line, which can be a horizontal plate or belt, and compressed in a hot press at a temperature of 150-250° C. and a pressure of 200 to 1000 psi. The hot press may be preceded by a cold press that expels air from the mat. The hot press may also be preceded by a pre-heater that accelerates the press cycle. For special applications, other materials may be added to the wood particles: for example, to protect against water, fungal attack, insects and fire. A primary difference between these wood composite products is in wood particle geometry.
[0243] Wood particles for MDF and HDF are fine wood fibers generally with a length from 1 to 5 mm and a diameter of under 0.1 mm. Such fine particles compress into a dense uniform board that is easily machined. It is widely used for interior furniture and doors. It is also used in cladding for walls and ceilings, usually covered with a veneer. It can be molded to form shaped skirtings, architraves and window boards and for decorative effect. It is also used as core material in laminate flooring.
[0244] Wood particles used in particleboard are typically much larger than used in MDF and HDF, with length in the range 2 to 15 mm and a diameter of 0.2 to 1.2 mm. The mechanical and decorative properties of the panel are improved by a density gradient across the panel, with finer particles in the outer layers. Finer particles can be separated by blowing or sieving. An array of rotating discs may also be used to orient the coarser wood material. Particleboard is less dense than fiberboard. It has similar uses. For example, faced with melamine it is used for furniture. It is also widely used for subfloor and roofing.
[0245] An OSB panel consists of mats of wood flakes (or strands) that are much larger than the particles in particleboard. Strands are cut to controlled dimensions—usually up to 150 mm long and 25 mm wide—from debarked small diameter logs. The strands are sifted and dried, treated with resin and conveyed to a forming line. Usually an OSB panel has three layers: outer layers sharing a common orientation of the grain in the strands and an inner core layer in which the grain of the strands is generally at right angles to the grain in the outer layers. The three layers are hot-pressed together.
[0246] OSB is stronger than particleboard and is a cheaper substitute for plywood. It is used in load-bearing applications, for example as subfloor or as components of bracing and I-beams.
Inserting Thermal Bridges During Manufacture
[0247] In all these instances of wood composite cladding, a description is given here of thermal bridges inserted during manufacture using minor variations of standard manufacturing processes. The advantages gained include low cost and low material wastage. By using thermal bridges with an open geometry, the wood composite retains its coherent structure and the mechanical properties of the cladding are not significantly compromised.
[0248] Where aluminum thermal bridges are embedded in wood composite panel, the panel containing aluminum thermal bridges can be sawed and nailed and machined in a normal fashion.
Bridges Effect on Productivity, Quality
[0249] Thermal bridges inserted during manufacture of wood composite can improve the productivity of the fiberboard production line because the improved heat transfer to the middle of the compressed mat speeds up the resin hardening. Product quality can also be improved using thermal bridges because faster, more even heating provides a more uniform product. Slow pressing times for thicker panels—up to 10 minutes per batch for panels over 12 mm—are considered to be a problem in the molded panel industry. See, for example, comments in US 20130048190 (Gupta et al).
[0250] Because the thermal bridge is incorporated before compression and resin hardening, it forms part of a coherent mass and so avoids significantly compromising the mechanical properties of the panel so made.
Protecting the Press
[0251] In molded wood production lines, metal detectors and magnets are used to find and remove any metal accidentally included in the formed mat. Therefore any metal thermal bridges incorporated in the mat should be added after unwanted metal has been detected and removed. The purpose of metal removal is to prevent damage to the moving parts of the line and especially to the presses. The thermal bridges used must be primarily of relatively soft material, such as aluminum, to avoid such damage. As additional protection, a replaceable shield layer, for example, a sheet of hardened steel, can be placed on the forming platform and/or on top of the mat. Where protection is required for a woven belt in a cold press, the shield layer can be perforated to allow removal of air in the mat, for example using a fine, flexible steel mesh.
Effect of Compression
[0252] In the above-mentioned products, the mat is compressed by a ratio of 5-10× in the hot press. As a result, any thermal bridge placed in the mat before pressing may be subject to significant deformation. The deforming behavior will vary by type of product. In the case of fiberboard, the homogenous mass of fine fibers can flow round the thermal bridge. Consequently, it is possible to insert into the fiber mat thermal bridges that have dimensions fitting the final thickness of the panel and to compress the mat without significant crushing of the bridges. In the case of particleboard and OSB, the non-homogenous arrangement of larger particles impedes penetration of the mat by the thermal bridge. One solution to this problem is to insert an over-sized thermal bridge into the mat and to allow this to be crushed by pressing.
Penetrating Thermal Bridge
[0253] Another solution is a penetrating thermal bridge. The compressive force of the cold or hot press can be exploited to create a substantively rectilinear thermal shunt in compressively molded cladding by placing suitable heat-conducting shapes in and on the mat. When compressed, these shapes penetrate the mat, are forced into intimate contact with each other, and are fixed in position by curing a binding agent. Bonding under pressure can greatly reduce contact resistance. Suitable shapes can be arranged to create a uniform array of substantively rectangular, effectively seamless thermal bridges.
Aluminum Adhesion
[0254] In all these instances, where aluminum is used for the thermal bridges, the embedded thermal bridges preferably constitute an open structure, permitting formation of a coherent mass of cured wood composite. This is because binding agents commonly used in wood composites—for example, urea formaldehyde resin—do not provide a wood-metal bond that is as strong as a wood-wood bond. To improve wood-metal adhesion, the resin can be modified (suitable commercial products are available) and the surface of the aluminum can be treated for example, by anodizing or with phosphonic acid, and pre-coated with resin. Suitable heat-cured adhesives for aluminum include single component epoxies and polyurethane glues: these can be used as the binding agent for the wood composite.
Fiberboard
[0255] The advantages listed above for plasterboard as a radiant surface also apply to fiberboard. Fiberboard is widely used as a layer in laminate flooring and is also used, usually as a laminate, in wall and ceiling panels.
[0256] Fiberboard is available in a range of thicknesses: from 2 mm (⅛ inch) to 60 mm (1⅜ inch). 12 mm is a typical thickness for decorative cladding.
[0257] The thermal conductivity of fiberboard varies with density, varying from 0.10 watts/m° C. (MDF) to 0.14 watts/m° C. (HDF).
Temperature Drop
[0258] From equation 3, the temperature drop for 12 mm MDF cladding used for radiant heating or cooling, for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.012/0.10=6° C. to 12° C.
[0259] This is a large temperature drop, making the use of MDF panels without thermal bridging inefficient as radiant panels.
[0260] High-purity aluminum is up to 2300× more thermally conductive than fiberboard so that, in principle 0.05% by volume of high-purity aluminum used as a thermal shunt can cut the temperature drop across the board by 50%. If the heat-collecting/dispersing layers on each side of the board are 0.05 mm thick, then, for a 12 mm board these constitute an additional 0.1/12=0.8% by volume of the total board. So less than 1% by volume of aluminum can, in principle, halve the temperature drop across a 12 mm panel of fiberboard
[0261] A thermal bridge can be constructed in fiberboard using the methods already described for plasterboard:
Honeycomb shunt Rectangular spirals Rectangular loops and rolls Rectangular corrugated mesh Rectangular loop pressed sheet Flapped pressed sheet Embedded cuboids Wrapped sections
Honeycomb
[0270] As an example, in an embodiment of the present invention, a sheet of aluminum honeycomb having a height equal to the thickness of the finished fiberboard panel is bonded to a flat aluminum sheet that rests on the forming platform. Fine resinated wood fibers are poured over the honeycomb until the full height of the mat is reached. Then the mat is covered by a second flat aluminum sheet that carries a curable adhesive layer. During hot pressing, the honeycomb is forced into intimate contact with the upper flat aluminum sheet and is bonded in place, so that thermal contact resistance is low. The result is a uniform array of effectively seamless rectangular thermal bridges across the panel.
[0271] To avoid shear forces on the honeycomb, any pre-pressing is preferably carried out with a vertically operating press.
Rectangular Spirals
[0272] As an example, a uniform planar array of spirals of aluminum wire is placed on the forming platform. The axes of the spirals are aligned with one of the sides of the panel being produced. The spirals are rectangular in cross-section with a height equal to the thickness of the final panel. One face of the rectangular spirals is against and parallel to the forming platform. Fine wood fibers are poured on to the spirals, flowing between and over the spiral coils. After hot pressing, portions of the spiral wire are on the two surfaces of the panel and parallel to the plane of the panel. These portions of the spirals act as heat-collecting and heat-diffusing surfaces. This surface wire is joined seamlessly by wire that is straight and perpendicular to the mat, acting as a thermal shunt. The result is a uniform array of rectangular and seamless thermal bridges across the panel.
[0273] The spirals can be made crush-resistant by selecting a strong aluminum alloy and by increasing the wire diameter. The wire can also be flattened vertically to align with the motion of the press.
[0274] Spirals can be substituted by woven rectangular loops or by rectangular rolls of mesh.
Rectangular Corrugated Mesh
[0275] Mesh with rectangular corrugations can be made crush-resistant. A sheet of such corrugated mesh made with a height equal to the thickness of the finished panel can be embedded in the pre-press mat. On pressing, the fine fibers flow through the apertures of the mesh and the mesh does not deform. On hot pressing, the mesh is fixed in place by curing of the binding agent, resulting in a uniform array of seamless rectangular thermal bridges across the panel.
Rectangular Loop Pressed Sheet
[0276] A sheet with pressed rectangular loops can be made crush-resistant, for example, by twisting the loops so that the loops have edges aligned with the motion of the press. A sheet of such loops made with a height equal to the thickness of the finished panel can be embedded in the pre-press mat. On pressing, the fine fibers flow round the loops and the loops do not deform. On hot pressing, the loops are fixed in place by curing of the binding agent, resulting in a uniform array of seamless rectangular thermal bridges across the panel.
Embedded Cuboids
[0277] Dispersed heat-conducting shapes can be made crush-resistant by, for example, pre-filling such shapes. For example, fiberboard can be pressed in the form of fiberboard rods with a square cross-section. Aluminum sheet is wrapped round the rods, for example, in a continuous spiral and bonded to the rods. The rod is cut into sections, forming elongated cuboids wrapped in aluminum, the wrapped cuboids having a height that equals the thickness of the finished panel. The wrapped cuboids are arranged in a uniform planar array on the forming platform or simply dispersed uniformly on the forming platform, noting that elongated cuboids are self-righting. Fibers are poured on to the cuboids and, on pressing, flow round them. On hot pressing, the cuboids are fixed in place by curing of the binding agent, resulting in a uniform or dispersed array of seamless rectangular thermal bridges across the panel.
[0278] If, for example, the cuboids are uniformly spaced so as to occupy 50% of the area of the forming platform, then the resulting panel will also be 50% cuboids by volume and the volume of mat required will be 50% of the volume required without cuboids. Varying the percentage of cuboids changes the thermal and mechanical properties of the panel.
[0279] Pre-filled cuboids can be filled with conductive material. For example, conductive porcelain can be pressed and fired in the form of cuboids that are then wrapped with aluminum sheet.
[0280] In all these instances of crush-resistant thermal bridges, the fibers must be able to flow round the bridges during pressing. This flow can be improved by adding lubricants in the pre-press mat: for example, by suspending the wood particles in water as is done in the so-called wet-manufacturing process used for making fiberboard. This wet process is similar to the dry process, except that the pre-press mat is drained before hot pressing.
Deformed Spirals
[0281] Instead of using crush-resisting thermal bridges, the elements of the thermal bridge can be deliberately deformed. As an example and as an alternative embodiment of the present invention, a uniform array of aluminum spirals is placed on the forming platform. The spirals are circular in cross-section and have a diameter exceeding the final thickness of the panel. Fibers are poured into and over the spirals to from a mat. Hot-pressing deforms the circular spirals into flat ovoid spirals that bridge the final panel. The initial spacing of circular spirals on the forming platform determines the gaps between flat ovoid spirals in the final panel. The spacing can be selected so that the ovoid spirals are separated or abut each other or intersect.
[0282] The spirals described above can be made of aluminum strip. Spirals can be substituted by rolls that are constructed of folded perforated sheet or folded woven aluminum wire or strip or folded expanded aluminum mesh.
[0283] If hot-pressing increases the density of the pre-press mat by a factor of 10×, then the horizontal length of a flat ovoid spiral, assuming no stretching of the spiral material, is πR 2 /10t where R is the radius of the spiral and t is the intended thickness of the panel. If, for example, t is 12 mm and R is 60 mm—easily large enough to accommodate wood strands up to 50 mm wide—then the length of the ovoid is 94 mm. Therefore, in principle, a forming platform that is say, 2440 mm (8 feet) wide can be loaded with an aligned array of filled circular spirals, with the number of such spirals being 2440/94=26. With this number of spirals, the spacing between circular spirals is such that the resulting ovoid spirals abut each other and, with ideal spacing of the spirals, the ovoid spirals press together to form substantively rectangular spirals. With wider spacing, additional thermal shunts or wood particles can be placed on the forming platform between the spirals before pressing.
Penetrating Thermal Bridges
[0284] An alternative form of thermal bridge exploits the compression step in the panel manufacturing process. Heat conducting elements that are initially separate are brought together forcefully during pressing and are fixed in place by curing of the binding agent.
Penetrating Pressed Sheet
[0285] As an example of a penetrating thermal bridge and as an embodiment of the present invention, penetrating members (teeth, edges or spikes) are pressed from aluminum sheet and are continuous with that sheet. In an instance, aluminum sheet is slit into a uniform array of cross-shaped slits. Each cross of slits is pressed at right angles to the plane of the sheet to form four vertical V-shaped teeth, where the angle of the V is a right angle. By crossing three cuts and pressing, six teeth are formed each with a V-shape of 60 degrees. By using more cuts, more teeth can be formed.
[0286] Alternatively, aluminum sheet is slit in an array of pairs of slits and each pair of slits is joined in the middle by a right-angle cut, a diagonal cut or by a zigzag cut. When the sheet between the cuts is pressed at right angles to the plane of the sheet, vertical flaps are formed with straight, guillotine and saw-tooth profiles respectively.
[0287] In all these instances, to enable effective penetration of the mat without deformation of the thermal bridge:
The pressed sheet can be made of a hard alloy such 2000 series or 7000 series aluminum. These alloys can contain up to 15% of other metals, notably including copper and zinc respectively. Increased hardness is at the price of reduced thermal conductivity. The aluminum sheet can be cut at an angle so that the edge of the penetrating member is sharp. Before cutting the aluminum sheet, each area to be cut can be stretch-pressed into a curve, so that each penetrating member is curved around the vertical axis.
[0291] In all these instances, the manufacturing process for the penetrating pressed sheet is simple and material wastage is insignificant.
Drawn Edges and Spikes
[0292] Alternatively, the sheet is pressed and drawn to form an array of circular edges or an array of conical indentations. Circular edges are more crush-resistant than linear edges and so permit the use of penetrating bridges with less aluminum or softer (and more conductive) aluminum. Conical indentations (or spikes) are especially suited to penetrating wood composite with a ply structure: any linear edge will interfere with at least one ply layer. Additionally a conical geometry is crush-resistant. Conical indentations of 15 mm length (the thickness of typical OSB subfloor) or more, pressed out of thin sheet, require a malleable alloy: for example 3000 series, as used in deep drawing of aluminum cans. Circular edges and conical indentations both require use of female draw cavities so that the metal is molded and not simply stretched thinner. Multiple drawings are required.
[0293] A sheet with an array of conical indentations must also have an array of small holes punched in it if it is used as the upper layer of a pre-press mat. The small holes allow air to be evacuated when pressing the mat.
[0294] In all these instances of penetrating pressed sheet, it is preferable to have a pattern of pressing that is staggered to avoid forming aligned cuts in the panel with consequent weakening.
[0295] In all these instances, the height of the penetrating members is at least the thickness of the final panel.
[0296] Aluminum sheet is placed on a protective plate on the forming platform and wood fiber is poured on to the sheet until the mat has reached its desired thickness. Preferably the aluminum sheet is a malleable alloy. The protective plate can be a thin panel of wear-resistant hardened steel. Such steel can have a Mohs hardness that is up to three times higher than aluminum. The penetrating pressed sheet is placed on top of the mat with the penetrating members facing vertically downwards. During hot pressing the penetrating members are driven into forceful contact with the lower aluminum sheet. Edges penetrate the lower aluminum sheet and are molded into the sheet by the hard protective plate. The assembly is fixed in place by curing of the binding agent.
[0297] The result is a uniform array of effectively seamless rectangular thermal bridges through the panel.
[0000] Pressing with Soft Resilient Layer
[0298] In an alternative adaptation of the standard manufacturing process, the panel is pressed using a soft resilient layer. Penetrating pressed sheet is arranged on a forming platform, with penetrating members pointing upwards. The fiber mat is placed on the array of members. On top of the mat is a plain aluminum sheet and on top of the sheet is a soft resilient layer and above this layer is a hardened steel plate. The steel plate can be attached to the top face of the press. The penetrating members are longer than the final thickness of the panel. In a cold press cycle, the members pierce the mat, the aluminum sheet and the soft layer to create an array of members that project through the aluminum sheet. The soft layer is removed and the upper surface of the aluminum sheet is sprayed with bonding agent. The array of projections is folded over by a roller and then the panel is hot-pressed so that the projections are laminated to the aluminum sheet. Bonding of aluminum under pressure reduces the contact resistance to a low value. The soft layer is usable for a limited number of press cycles and should be cheap. As an example, the soft layer can be a resilient natural or mineral felt. The used felt retains value as material for insulation and as filler for composite board.
[0299] By using a sufficient density and length of penetrating members, the folded over members can act as a heat-collecting or diffusing layer, so that the upper aluminum sheet can be omitted. This solution is a variant of the flapped pressed sheet method described under plasterboard. Because this version of thermal bridge is seamless, there is no contact resistance.
Penetrating Troughs and Caps
[0300] As an alternative to using a pressed sheet, the penetrating members can be made individually and arranged in an array. For example, the individual member can have a ‘bottle-cap’ shape that is easily mass-produced to the required depth on existing machinery. As another example the member can have the shape of a trough.
[0301] As an example of a penetrating bridge, in an embodiment of the present invention, aluminum sheet is cut into parallel strips and each strip is folded into an elongate trough shape with a rectangular U-shape cross-section. The walls of the U-shape have a height that is slightly more than the thickness of the finished panel. This is a simple procedure with no material wastage. A flat aluminum sheet is placed on the forming platform and the fiber mat is poured on to this sheet. A uniform array of troughs is placed on top of the mat, with the U-shape inverted. During hot pressing, the troughs penetrate the mat, come into forceful contact with the lower aluminum sheet and are fixed in place. The result is a uniform array of seamless rectangular thermal bridges across the panel.
Penetrating Pressed Sheet Used in Uncompressed Setting Layers
[0302] Penetrating pressed sheet can also be used for uncompressed setting layers such as plasterboard, wet screed and dry screed. In an example, a penetrating pressed aluminum sheet is placed on a horizontal forming platform, with the penetrating members upright. The paste for dry screed panel is poured on to the pressed sheet until the required thickness is achieved. The penetrating members are sufficiently long to project above the paste. The paste is allowed to set, then a plain sheet of aluminum is arranged to cover the array of tips of the projecting members and a hardened steel plate is placed on the plain sheet. Downward pressure is applied to the plain sheet so that the tips of the penetrating members are driven into the plain sheet and molded into the sheet.
[0303] The result is a uniform array of effectively seamless rectangular thermal bridges through the panel.
Particleboard
[0304] Variations of the methods described so far can also be applied in the manufacture of particleboard.
[0305] The advantages listed above for plasterboard as a radiant surface also apply to particleboard. Particleboard is widely used as a subfloor, as a layer in engineered wood flooring and is also used, usually as a laminate, in wall and ceiling panels.
[0306] Particleboard is available in a range of thicknesses: from 2 mm (⅛ inch) to 40 mm (1⅜ inch). 19 mm is a typical thickness for subfloor.
[0307] The thermal conductivity of particleboard varies with density, varying from 0.07 watts/m° C. to 0.18 watts/m° C.
Temperature Drop
[0308] From equation 3, the temperature drop for 19 mm light particleboard subfloor over a radiant heating or cooling source, for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.019/0.07=13.5° C. to 27° C.
[0309] Without thermal bridging through the subfloor, it is not efficient to run an under-floor radiant system with the heating or cooling source under a particleboard subfloor.
[0310] The larger and elongate particles of particleboard prevent the easy flow of particles around an embedded thermal bridge. Solutions include thermal bridges with crushed shunts and penetrating bridges.
Deformed Spirals
[0311] As an example of a crushed thermal bridge, a uniform and aligned array of rectangular spirals of aluminum wire is placed on a forming platform. The spirals are preferably oriented to reduce interference with elongate particles in the core of the mat. The axes of the spirals can be at right angles to the preferred orientation of the elongate particles, with gaps between spiral turns sufficiently wide to enable migration of elongate particles into the gaps. Alternatively the axes of the spirals can be aligned with the elongate particles and the spirals are prefilled with particles. The height of the spirals initially equals the height of the mat. Hot pressing deforms the vertical portions of the spirals. The result is a uniform array of seamless thermal bridges with rectilinear heat-collecting and heat-dispersing surfaces.
Penetrating Bridges
[0312] All the instances of penetrating bridges already described under fiberboard are applicable.
Oriented Strand Board (OSB)
[0313] The thermal bridging methods described in the case of particleboard above can also be applied in the manufacture of OSB.
[0314] The advantages listed above for plasterboard as a radiant surface also apply to OSB. OSB is widely used as a load-bearing constructional panel in floors, walls and ceilings.
[0315] OSB is commonly made in three layers. The thicknesses of three-layer OSB panel range from 6 mm (¼inch) to 18.5 mm (¾inch). OSB is available up to 38 mm. 15 mm is a typical thickness for subfloor.
[0316] The thermal conductivity of OSB is typically 0.13 watts/m° C.
Temperature Drop
[0317] From equation 3, the temperature drop for 15 mm OSB subfloor over a radiant heating or cooling source, for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.015/0.13=6.3° C. to 11.5° C.
[0318] Without thermal bridging through the subfloor, it is not efficient to run an under-floor radiant system with the heating or cooling source under an OSB subfloor.
Deformed Spirals
[0319] The combination of the three layers with differing strand orientation makes it difficult to incorporate a single continuous thermal bridge that does not interfere with the mechanical properties of at least one layer of the OSB panel. In an alternative embodiment of this invention, pre-filled circular spirals of aluminum wire or strip are placed in each layer of the uncompressed mat, with the height of the spirals at least equal to depth of the mat in which the spiral is embedded. Adjacent layers have spirals with axes at right angles. Hot pressing deforms the circular spirals in each layer to flat ovoid spirals, The ovoid spirals in adjacent layers are forced together and fixed in place by curing of the binding agent. The result is a uniform array of effectively seamless and substantively rectangular thermal bridges across the three layers.
[0320] Perforated cylinders can be substituted for circular spirals. In this case, pre-filling can be achieved by folding perforated sheet into a curved trough, filling the trough with strands that are generally aligned with the trough and folding the trough into a cylinder. The perforated sheet can, for example, be flattened expanded aluminum mesh.
Penetrating Pressed Sheet
[0321] All the instances of penetrating bridges already described under fiberboard are applicable.
[0322] Such bridges may be applied across all the OSB layers at one time or separate bridges may be installed in each layer and then forced together.
[0323] In an example, a penetrating pressed sheet of aluminum, with upright penetrating members, is placed on the forming platform and three layers of strands are poured on to the sheet. An aluminum mesh is placed on top of the mat. During hot-pressing, the strands are penetrated, these penetrating members come into forceful contact with the upper aluminum layer and are fixed in place by curing of the binding agent. The result is a uniform array of effectively seamless and substantively rectangular thermal bridges across the three layers.
[0324] In an alternative example, an aluminum sheet is placed on the forming platform. The lower layer of strands is poured on to this sheet. A penetrating pressed sheet of aluminum is placed on this lower layer with penetrating members pointing downwards and these members having edges aligned with the general orientation of strands in the lower layer.
[0325] The middle layer of strands is poured and a penetrating pressed sheet of aluminum is placed on this middle layer with penetrating members pointing downwards and these members having edges aligned with the general orientation of strands in the middle layer.
[0326] The upper layer of strands is poured and a penetrating pressed sheet of aluminum is placed on this upper layer with penetrating members pointing downwards and these members having edges aligned with the general orientation of strands in the upper layer.
[0327] During hot pressing, the members penetrate the layers of the mat and are forced together and in the lower layer, members are forced against the lower sheet, and fixed in place by curing of the binding agent. The result is a uniform array of effectively seamless and substantively rectangular thermal bridges across the three layers.
Plywood
[0328] Plywood is used in floors, walls and ceilings. As an example, plywood provides a stabilizing layer for floor coverings such as tile and linoleum. Where there is under-floor radiant heating this layer represents a significant thermal resistance, which can be reduced by thermal bridging.
[0329] Conventional plywood is not a molded product. Instead it is produced by peeling veneer from rotated logs and gluing veneers together at temperatures of at least 140° C. and pressures of 80 to 300 psi. Again there is an opportunity to use this compression to form an effective thermal bridge across the plywood panel.
Penetrating Pressed Sheet
[0330] In an embodiment of the present invention, before pressing, a stack of veneers is placed on a sheet of aluminum. On the upper face of the stack of veneers is arranged a penetrating pressed sheet of aluminum with penetrating members pointing downwards. In the hot press, the troughs are driven through the veneers into forceful contact with the lower aluminum sheet and fixed in place. The result is a uniform array of seamless rectangular thermal bridges.
[0331] To assist penetration, veneers can be temporarily softened, for example by spraying with an aqueous solution of plasticizer.
[0332] By staggering the array of penetrating members in both dimensions of the panel, the risk of splitting a veneer is reduced.
Engineered Wood Floorboard
[0333] If cost and low thermal resistance were the only criteria, most floors would be covered by thin vinyl. Aesthetic appeal means that wood flooring is often preferred in domestic living spaces. But wood is a thermal insulator. At peak heat flows, the temperature drop across a thick wood floor can rise to over 9° C. Since the surface temperature needs to be around 21-23° C., this requires a subsurface temperature over 30° C., exceeding the limits set by most wood-floor suppliers to avoid potential problems of warping. European regulations, dating to 2001, limit the temperature drop across the floor, including any underlay or further covering, to 7.5° C. The problem is worsened by use of rugs. The warping risk is greatly reduced by using an engineered wood floor, comprising an upper veneer of hardwood bonded to one or more lower layers of less expensive softwood, plywood or fiberboard. But the large temperature drop remains and this reduces the efficiency of the heating system.
Temperature Drop
[0334] A typical engineered wood floorboard comprises 1 to 6 mm of hardwood veneer bonded to 8 to 13 mm of other wood material. As an example, the hardwood veneer is 4 mm, the other wood material is 10 mm, and average thermal conductivity is K=0.14 watts/m ° C.
[0335] From equation 3, the temperature drop across the floor for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.014/0.14=5° C. to 10° C.
[0336] The upper hardwood layer cannot be thermally bridged without changing its appearance. Thermal bridging is therefore applicable only to the lower layers of the engineered wood floor. As a result, bridging offers diminishing returns. In the example given, even if the thermal resistance of the lower layers is reduced to zero, there will be a temperature drop of:
[0000] (5−10)×4/14=1.4° C. to 2.8° C.
Thermal Bridging
[0337] In an embodiment, engineered wood floor is thermally bridged by using thermally bridged wood composite such as high density fiberboard for the layers below the hardwood veneer. Any of the methods already described for bridging wood composite can be used. The composite can be molded to be the entire layer below the hardwood veneer, including molded tongue and groove.
Molded Ceramic Bridge
[0338] In another embodiment, layers of wood below the hardwood veneer are bridged by heat-conducting ceramic. For example, the thermal conductivity of porcelain of standard commercial composition can be improved to K=2 watts/m° C. by extended heating at higher than normal temperatures. The result is inexpensive porcelain with increased density and lower porosity. This is 20× the thermal conductivity of, for example, pine. Therefore a thermal shunt of porcelain bridging just 5% of the area of a softwood layer can halve the temperature drop across this layer. The ceramic thermal shunt can be bonded to a heat-collecting layer and a heat-dispersing layer that are both aluminum sheet. This embodiment can be described as a tile/board hybrid: having the desirable thermal properties of tile combined with the desirable appearance and handling of tongue and groove floor board.
Wrapped Sections
[0339] In another embodiment, engineered wood floor is thermally bridged by:
Dividing the lower layers of the floorboard into elongate sections. Wrapping heat-conducting sheets round each section and bonding the sheets to the wood Bonding the sections together.
[0343] In this instance, the three elements of the thermal bridge are all provided by the same continuous sheets.
[0344] By increasing the number (ie reducing the width) of the wrapped elongate bonded sections in a floorboard, the number of thermal shunts embedded in the floorboard is increased and the overall thermal path across the board is shortened, so improving heat transfer performance. However, the cost of manufacture and material wastage is also increased. Therefore it can be advantageous to use fewer elongate sections per floorboard and to fix additional thermal shunts between the bonded sections: for example, fixing molded ceramic shunts between sections.
Trials
[0345] In a series of trials, foils of different thicknesses were wrapped around insulating segments of different thicknesses and the temperature drops were compared.
[0346] In an example, an engineered floorboard 125 mm wide was created from a top ‘veneer’ of 3.8 mm plywood and a core of 12 mm MDF. The MDF was split into two longitudinal sections and each section was wrapped in a 0.15 mm layer of high-purity aluminum foil, crossing the thickness of the MDF only on the inside of the board. The volume of aluminum used was 2.7% of the total volume of the board. The temperature drop across the modified floorboard was reduced by approximately 50% compared with the untreated floorboard.
Laminate Floorboard
[0347] In another embodiment of the present invention, the cladding is a laminate floorboard. This differs from an engineered wood floorboard by not having a hardwood veneer. Instead, the upper surface comprises a decorative layer, usually simulating wood, protected by a transparent wear layer of paper impregnated with melamine resin. Below this is a core layer usually of fiberboard. Below the core layer is a stabilizing layer of resin-saturated paper.
[0348] Laminate floors are usually 8-10 mm thick and can be up to 12 mm thick. The wear layer is from 1 to 4 mm thick and the decorative layer is 0.2-0.3 mm thick.
[0349] An alternative laminate has an upper surface of decorative vinyl, a core layer of fiberboard, usually HDF and a lower layer of cork. The thickness of these layers is typically 2 mm, 7 mm and 1 mm respectively.
[0350] In an example of melamine laminate, the laminate board core and stabilizing layer is 8 mm thick and has an average thermal conductivity of 0.10 watts/m° C.
Temperature Drop
[0351] From equation 3, the temperature drop across the core for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.008/0.10=4° C. to 8° C.
[0352] The wear layer is 3 mm thick. The thermal conductivity of the wear layer is 0.4 watts/m ° C. The temperature drop across this is only 0.1-0.2° C. Therefore a thermal shunt across the core layer has a potentially large effect on temperature drop across the whole board.
[0353] As an embodiment, the core layer (for example, particleboard or fiberboard) has embedded thermal bridges as already described. If a honeycomb thermal shunt is used as previously described for plasterboard, with a reduction in temperature drop of 70%, then the overall temperature drop is reduced from 4.1° C.-8.2° C. to 30%×(4° C. to 8° C.)+(0.1° C. to 0.2° C.)=1.3° C. to 2.6° C. ie an overall reduction of 68%
[0354] The options for thermal bridging of laminate floorboard are the same as the options for thermal bridging of engineered wood floorboard.
Carpet Underlay
[0355] Underlay for carpet improves ‘feel’, wear and insulation and under wood or laminate floors provides resilience, acoustic and thermal insulation and a buffer against an uneven subfloor. Such underlay is flexible and compressible and typically made of sponge or crumb rubber or plastic foam or wood fiber or felt. Typical underlay of this kind has a thickness from 2 mm to 6 mm under wood and 4 mm to 12 mm under carpet. The thermal conductivity of uncompressed nitrile rubber sponge is around 0.04 watts/m ° C. The conductivity of plastic foam or felt can be less than this; the conductivity of a dense crumb can be slightly more.
Temperature Drop
[0356] From equation 3, the temperature drop across typical 6 mm carpet underlay for Q=50 to 100 watts/m 2 is:
[0000] delta T =(50-100)×0.006/0.04=7.5° C. to 15° C.
[0357] This is not suitable for efficient under-floor heating.
[0358] By using carbon filler and a dense rubber sponge, thermal conductivity has been increased in a commercial product to 0.087 watts/m ° C. For a thickness of 6 mm, from equation 3, the associated temperature drop is:
[0000] delta T =(50-100)×0.006/0.087=3.5° C. to 7.0° C.
[0359] Combined with the temperature drop across typical carpet, this remains too high for an efficient radiant heating system.
Thermal Bridges for Pliable Cladding
[0360] A requirement for underlay is that the thermal bridges be pliable and compliant with repeated cycles of compression. Aluminum sheet is a suitable material, having a typical fatigue life of several million cycles. An embedded honeycomb is unsuitable since it cannot flex. Embedded wires are also unsuitable because the wires when flexing will tend to cut the surrounding material. Embedded thermal bridges described in previous sections are applicable, using flexible heat-conducting material, including:
Rectangular spiral strips where the strips are wide and flat Rectangular rolls of mesh Rectangular corrugated flat mesh, for example, flattened expanded aluminum sheet Rectangular folded L-shapes, including use of a flapped pressed sheet Rectangular loop pressed sheet where the loops are wide Embedded cuboids Wrapped and bonded sections Penetrating pressed sheet.
Extruded Underlay
[0369] In an example, underlay is manufactured by extruding foam plastic or rubber on to a moving belt and passing it through rollers. The plastic or rubber can be laminated with polymer or natural fiber layers.
[0370] In an example of the present invention, rectangular spirals of aluminum strip are fed on to the moving belt to form a uniform planar array. Foam is extruded on to the spirals and penetrates between the coils of the spirals. The spirals are the same height as the desired thickness of the underlay. The open structure of the spirals—ie the gaps between adjacent coils of the spirals—means that the cured foam of the underlay forms a continuous coherent mass. When the foam has set, the result is a uniform array of seamless rectangular thermal bridges across the underlay.
[0371] The spirals can be substituted by rectangular rolls of aluminum mesh, for example, flattened expanded aluminum. The spirals can also be substituted by a rectangular corrugated aluminum mesh or by a pressed aluminum sheet with rectangular loops or by a pressed aluminum sheet with flaps. In the last case, the flaps project above the foam layer. When the foam has set, the flaps are folded over by a roller to lie flat on the top surface of the foam layer.
[0372] Underlay is also manufactured by using granulating recycled rubber tires, or recycled plastic foam.
Rubber Crumb
[0373] In the former case, fine rubber granules (crumb) are mixed with aqueous latex and poured on to a textile or paper backing. The mixture is skimmed to the desired thickness and cured by heat. Aluminum spirals, mesh rolls, corrugated sheet or pressed sheet can all be covered by the aqueous latex-crumb mixture before curing to form uniformly distributed seamless rectangular thermal bridges across the underlay.
Rebonded Plastic Foam
[0374] In the latter case, shredded foam is mixed with a polyurethane binder and compressed and cured. In a batch process, the mix is pressed in a cylindrical mold. The resulting solid cured ‘log’ is then rotated and peeled into layers by a cutter. In a continuous process, the mix is pressed between rollers and the solid cured sheet is peeled into layers. Individual layers may be laminated to a plastic film or non-woven backing.
[0375] In a variation of this continuous process, cured sheet is produced at the desired thickness without peeling. This permits the underlay to be thermally bridged by the methods already described.
Wrapped Sections
[0376] Peeled foam underlay can be thermally bridged by cutting into sections, wrapping in aluminum sheet and bonding the sections back together.
Penetrating Pressed Sheet Using Soft Resilient Layer
[0377] Peeled foam can also be thermally bridged by using penetrating pressed sheet as described under the fiberboard section. A layer of peeled foam is arranged on a penetrating pressed aluminum sheet, with the penetrating members pointing vertically up. These members are longer than the final thickness of the foam. On the upper side of the peeled foam is laminated a plain sheet of aluminum. On top of the aluminum is a layer of resilient felt, made, for example, of wool. The sandwich of felt, aluminum sheet, peeled foam and penetrating pressed sheet is compressed so that the penetrating members pass through the foam and the plain aluminum sheet and into the felt. After pressing, the felt layer is removed for later use, leaving penetrating members projecting through the foam. The upper surface of the plain aluminum sheet is sprayed with bonding agent. A roller is passed over the peeled foam and folds the projecting penetrating members on to the plain sheet. The sandwich is then pressed again and the folded members and sheet are bonded together under pressure.
[0378] Since both foam and felt are easily penetrated, the required penetrating pressed sheet can be much thinner than is needed for penetrating wood composite. Using a sufficiently dense and long array of penetrating members, the upper aluminum sheet can be dispensed with, since the members become the upper heat-conducting surface. This is a variant of thermal bridging using flaps, as described for plasterboard.
[0379] Any weakening of the foam layer caused by penetration is easily compensated by laminating the foam to a tough backing layer, for example, non-woven fabric, before placing the foam layer on the penetrating pressed sheet.
[0380] The result is a uniform array of seamless rectangular bridges across the plastic foam underlay.
Rollability of Bridged Underlay
[0381] Underlay is stored and distributed in rolled form. The thermal bridges described here can accommodate rolling. For example, an array of parallel spirals embedded in foam rubber or plastic or in rubber crumb in cured latex allows rolling in a direction at right angles to the spiral axes. Likewise, penetrating pressed sheets can be applied in parallel strips, so allowing rolling in a direction at right angles to the strips.
Trial
[0382] In a trial, 10 mm rubber crumb carpet underlay was completely wrapped in 100 mm sections with soft 0.05 mm aluminum tape and the sections were then taped together. The volume of aluminum used was 1.1% by volume of the taped underlay. The temperature drop across the underlay was reduced by 50% at the section seams and by 16% at the section midpoints or around 30% on average. The average temperature drop across the underlay could be increased by increasing the density of seams (ie reducing the width of taped sections) and/or by increasing the thickness of the aluminum tape.
Tufted Carpet and Carpet Tiles
[0383] Over 70% of all carpet sold in the US and Europe is tufted. It is manufactured by inserting yarn through a primary backing fabric, cementing the yarn in place and then covering the primary fabric with a secondary backing fabric. The yarn is cut to create a tufted pile. The yarn fiber may be natural (usually wool) or artificial (usually nylon, polypropylene, polyester or acrylic) or a combination of these. The backing fabrics may be woven or non-woven. A typical tufted carpet has a tuft depth of around 8 mm and a total backing thickness of 3 mm. Carpet tiles typically have shorter tufts: between 3 and 5 mm with a 3 mm backing layer of vinyl reinforced with glass fiber. The yarn may be left looped.
Temperature Drop
[0384] The thermal resistance of carpets is usually described by the tog rating, defined as 10× the temperature drop that transmits one watt per m 2 . Typical domestic tufted carpets have tog ratings between 1 and 2. The temperature drop for Q=50 to 100 watts/m 2 is therefore:
[0000] delta T =(50-100)×(1-2)/10=5° C. to 10° C. for the lower tog rating and 10° C. to 20° C. for the higher tog rating
[0385] The upper end of this range is unacceptable for an efficient under-floor heating system.
[0386] The backing layer is usually made of natural and/or artificial fibers and latex. Thermal conductivities for relevant materials: polypropylene, jute and latex are 0.22 watts/m° C., 0.05 watts/m° C. and 0.14 watts/m° C. respectively. The overall conductivity is assumed to be 0.15 watts/m° C.
[0387] From equation 3, the estimated temperature drop across the backing layer alone is:
[0000] delta T =(50-100)×0.003/0.15=1° C. to 2° C.
[0388] The backing therefore represents 10-20% of the thermal resistance of the carpet.
[0389] The British Standard EN 1264 advises a maximum tog of 1.5 for carpet and underlay together, implying that many combinations of carpet and underlay are unsuitable for heated floors. However, a 2005 study by the UK Building Services Research Association (BSRA) indicates that carpet tog ratings are systematically over-stated: the BSRA tog results for a sample of tufted carpets plus underlay are, on average, 40% below the published figures. This implies that the backing layer represents as much as 30% of the thermal resistance of the carpet.
Reducing Thermal Resistance of Carpet; Prior Art
[0390] The thermal resistance of tufted or looped carpet may be reduced by:
Using shorter tufts or loops. Using a lower density of tufting. Changing the composition of the yarn. For example, by adding synthetic graphite to Nylon 6-6, the thermal conductivity can be increased from 0.3 watts/m° C. to 1.8 watts/m° C. Changing the composition of the materials of which the primary and secondary backing layers are made. Changing the composition of the adhesives used. Using thermal bridging in the backing layers.
[0397] Prior art describes electrically conductive carpet intended to avoid build-up of static charge. Such carpet typically uses yarn with carbon-coated fibers that will conduct a charge of several thousand volts to a backing that is made electrically conductive using a carbon-impregnated latex or by also using carbon-coated fibers. Carbon-coated fibers limit the appearance of the yarn, which may not be important in commercial applications but is unacceptable in domestic use. This arrangement will not conduct significant amounts of heat. Prior art describes electrically conductive yarn using 20-50% by weight of electrically conductive filler, attached to a backing made of resin with similar quantities of conductive filler. Large percentages of electrically conductive filler also improve thermal conductivity but require significantly more added conductive material than an efficient thermal bridge, Prior art also describes attaching a very thin metal foil layer to the underside of the backing so that the foil grounds any static voltage in the yarn. This arrangement on its own does not increase the transfer of heat through the backing.
Folded Thread Loops
[0398] In an embodiment of the present invention, the backing is thermally bridged by an adaptation of the standard manufacturing process:
Incorporating heat-conducting threads into the primary backing layer: this becomes the heat-dispersing layer. Incorporating heat-conducting threads into the secondary backing layer: this becomes the heat-collecting layer. Weaving or pulling loops of heat-conducting thread out of the lower side of the primary backing layer. If the heat-conducting threads are loose in the primary backing layer then they will be pushed out when tufts are pushed through the backing. When latex solution is sprayed on to the primary backing layer to anchor the tufts, these loops project through the latex. When the secondary backing layer is added, the loops are bent over. The loops are the thermal shunt.
[0402] Instead of using latex, hot-melt glue can be used: for example, by including hot-melt fibers in the primary backing layer.
[0403] This method is a variation of the thermal bridge already described that is based on bending an L-shaped strip in a molded cladding.
Conductive Granules
[0404] In another embodiment of the present invention, the backing is thermally bridged by another adaptation of the standard manufacturing process:
Incorporating heat-conducting threads into the primary backing layer: this becomes the heat-dispersing layer. Incorporating heat-conducting threads into the secondary backing layer: this becomes the heat-collecting layer. Incorporating heat-conducting spherical granules into the cement that joins the primary and secondary backing layers. The granules have a diameter equal to the gap between primary and secondary backing layers. The diameter is greater than the spacing between threads in the backing layers, so that the granules are trapped between these layers. As a result of cementing under compression, the granules migrate to the voids between tufts and provide a thermal shunt that connects the heat-dispersing layer with the heat-collecting layer. In the case of standard 3 mm backing, the granule diameter is around 1.5 mm.
[0408] This method is a variation of the thermal bridge already described using heat-conducting shapes with a cross-section equal to the width of the bridged cladding layer.
[0409] In an embodiment, the heat-conducting threads are high-purity aluminum wire and the heat-conducting granules are smooth spheres of high-purity aluminum. The aluminum wire can be anodized to improve radiant heat transfer.
[0410] The heat-conducting threads can also be polymer fiber filled with conductive particles: for example, polypropylene loaded with graphite. The heat-conducting granules can be graphite.
[0411] In an embodiment, a heat-conducting foil is bonded to the top of the primary backing layer: this becomes the heat-dispersing layer. The foil is soft and is perforated by the tufting process. A heat-conducting foil is bonded to the bottom of the secondary backing layer: this becomes the heat-collecting layer. In an embodiment, these foils are high-purity aluminum.
Penetrating Pressed Sheet
[0412] Thermal bridges across tufted carpet backing can also be constructed using a version of the penetrating pressed sheet already described under fiberboard. Penetrating pressed sheet is laminated to the secondary backing layer so that the penetrating members penetrate the secondary backing layer. Liquid latex is applied to the secondary backing layer so that the penetrating members project through the latex. The primary backing layer incorporates aluminum threads and so is heat-conducting. Tufts are inserted in the primary backing layer and this tufted layer is pressed down on the latex. The penetrating members engage with the aluminum threads in the primary backing layer. The latex is cured. The resulting layers comprise, in sequence: tufted yarn, heat-conducting primary backing layer, cured latex bridged by penetrating members, secondary backing layer, base of penetrating pressed sheet.
[0413] The result is a uniform array of rectangular thermal bridges.
[0414] The described thermal bridges also prevent the build-up of static charge in the carpet.
BRIEF DESCRIPTION OF DRAWINGS
[0415] All figures are schematic and not to scale.
[0416] All figures illustrate embodiments of thermal bridges in cladding.
[0417] FIG. 1 a : cut-away plan view: panel with thermal bridge using honeycomb aluminum as a thermal shunt.
[0418] FIG. 1 b : cross-section of panel with thermal bridge using honeycomb.
[0419] FIG. 2 a : plan view: top of panel with thermal bridge using rectangular aluminum spirals.
[0420] FIG. 2 b : cross-section of panel with thermal bridge using rectangular aluminum spirals.
[0421] FIG. 3 a : plan view: panel with thermal bridge using rectangular corrugated aluminum mesh.
[0422] FIG. 3 b : cross-section of panel with thermal bridge using rectangular corrugated aluminum mesh.
[0423] FIG. 4 a : plan view: array of L-shaped aluminum strips.
[0424] FIG. 4 b : cross-section of array of L-shaped strips before moldable filler is added.
[0425] FIG. 4 c : cross-section: L-shaped strips embedded in a molded panel and bent into a rectangular reverse C shape.
[0426] FIG. 4 d : cross-section: L-shaped strips embedded in a molded panel and bent into a rectangular S shape.
[0427] FIG. 5 a : plan view: section of aluminum sheet with pattern of slits for flaps.
[0428] FIG. 5 b : perspective view: individual raised flap.
[0429] FIG. 5 c : plan view: section of aluminum sheet with pattern of slits for loops.
[0430] FIG. 5 d : perspective view: individual raised rectangular loop.
[0431] FIG. 6 a : cross-section: wrapped separate sections of cladding panel.
[0432] FIG. 6 b : cross-section: wrapped sections of panel joined together.
[0433] FIG. 6 c : cross-section: wrapped sections of panel joined together with a ceramic shunt.
[0434] FIG. 7 a : perspective view: single fiberboard cuboid wrapped in rectangular aluminum spiral.
[0435] FIG. 7 b : cross-section: cuboids embedded in pre-press mat.
[0436] FIG. 7 c : cross-section: cuboids embedded in panel.
[0437] FIG. 8 a : cross-section: array of circular aluminum spirals filled with pre-press mat.
[0438] FIG. 8 b : cross-section: array of spirals deformed into ovoid spirals in panel.
[0439] FIG. 8 c : perspective view: circular spirals in vertical arrangement for three-ply panel.
[0440] FIG. 8 d : cross-section: curved aluminum mesh trough filled with wood strands.
[0441] FIG. 8 e : cross-section: curved aluminum mesh trough folded to form cylinder.
[0442] FIG. 9 a : plan view: single cross-shaped cut in aluminum sheet.
[0443] FIG. 9 b : perspective view: teeth raised from single cross-shaped cut.
[0444] FIG. 9 c : plan view: single H-shaped cut in aluminum sheet.
[0445] FIG. 9 d : perspective view: straight edges raised from H-shaped cut.
[0446] FIG. 9 e : plan view: single H-shaped cut with slanted cross cut in aluminum sheet.
[0447] FIG. 9 f : perspective view: guillotine edges raised from slanted H-shaped cut.
[0448] FIG. 9 g : plan view: single H-shaped cut with zigzag cross cut in aluminum sheet.
[0449] FIG. 9 h : perspective view: saw-tooth edges raised from H-shaped cut with zigzag cross cut.
[0450] FIG. 9 i : plan view: single V-headed cut at the end of parallel cuts in aluminum sheet.
[0451] FIG. 9 j : perspective view: aluminum sheet with single raised V-headed member.
[0452] FIG. 10 a : cross-section: single raised V-headed member penetrating hot-pressed panel and resilient felt layer.
[0453] FIG. 10 b : cross-section: single raised V-headed member folded and laminated to aluminum sheet.
[0454] FIG. 11 a : plan view: staggered pattern of H-shaped cuts on aluminum sheet.
[0455] FIG. 11 b : cross-section: penetrating pressed aluminum sheet on pre-press mat.
[0456] FIG. 11 c : cross-section: penetrating pressed aluminum sheet embedded in panel.
[0457] FIG. 12 a : cross-section: engineered wood floorboard without thermal bridge.
[0458] FIG. 12 b : cross-section: engineered wood floorboard with lower layers thermally bridged by rectangular aluminum spirals.
[0459] FIG. 12 c : cross-section: engineered wood floorboard with lower layers thermally bridged by a ceramic thermal shunt and aluminum sheets.
[0460] FIG. 12 d : cross-section: engineered wood floorboard with sections thermally bridged by wrapped aluminum sheet.
[0461] FIG. 13 a : cross-section: aluminum thread loops projecting through carpet primary backing layer.
[0462] FIG. 13 b : cross-section: aluminum thread loops embedded in carpet backing cement and folded against the secondary backing layer.
[0463] FIG. 13 c : cross-section: aluminum granules embedded in carpet backing cement.
DETAILED DESCRIPTION OF INVENTION
[0464] FIG. 1 a : cut-away plan view: panel ( 1 ) with thermal bridge using honeycomb ( 2 ).
[0465] This figure is cut away to show the separate layers of a panel of molded cladding ( 1 ) that, for example, can be plasterboard or fiberboard. The panel ( 1 ) has an embedded thermal shunt that is an aluminum honeycomb ( 2 ). The cells of the honeycomb ( 2 ) are filled with the material or filler ( 3 ) of the cladding ( 1 ). (Only one cell is shown filled in the plan view). The filler ( 3 ) can be plaster or can be wood particles combined with resin or can be another moldable constructional material such as, for example, cement. The honeycomb ( 2 ) is bonded by adhesive to a first heat collecting/dispersing layer ( 4 ) that is aluminum sheet laminated to the lower side of the panel ( 1 ) (not shown in the plan view) and to a second heat collecting/dispersing layer ( 5 ) that is aluminum sheet laminated to the upper side of the panel ( 1 ). In the case of plasterboard, the heat-conducting layers ( 4 and 5 ) allow drying of the plaster, for example, by being perforated, as shown in the plan view. The outer layers of the plasterboard are paper ( 6 ). The honeycomb ( 2 ) and the laminated sheets ( 4 , 5 ) constitute a uniform array of rectangular thermal bridges across the panel ( 1 ).
[0466] FIG. 1 b : cross-section of panel ( 1 ) with thermal bridge using honeycomb ( 2 ).
[0467] FIG. 2 a : plan view: top of panel ( 1 ) with thermal bridge using rectangular spirals ( 7 ).
[0468] A panel of molded cladding ( 1 ) has an embedded thermal bridge that is a row of rectangular spirals ( 7 ) made of aluminum wire or strip. The spaces between the turns of the spirals ( 7 ) are filled with the filler ( 3 ) of the cladding ( 1 ) (the filler is not shown in the plan view). The upper edges of the spirals ( 7 ) serve as a first heat collecting/dispersing layer ( 4 ) and the lower edges of the spirals serve as a second heat collecting/dispersing layer ( 5 ). The spirals ( 7 ) constitute a uniform array of seamless rectangular thermal bridges across the panel ( 1 ). Using almost the same figure, spirals ( 7 ) can be substituted by rolls (or cylinders) of aluminum mesh (not shown), also with a rectangular cross-section. Cylinders of rolled mesh are referenced in FIGS. 8 d and 8 e.
[0469] FIG. 2 b : cross-section of panel ( 1 ) with thermal bridge using rectangular spirals ( 7 ).
[0470] An almost identical figure would show the spirals ( 7 ) substituted by rolls (or cylinders) of aluminum mesh (not shown), also with a rectangular cross-section.
[0471] In this instance, the panel ( 1 ) is plasterboard and has outer layers of paper ( 6 )
[0472] FIG. 3 a : plan view: panel ( 1 ) with thermal bridge using rectangular corrugated mesh ( 8 ).
[0473] An aluminum mesh ( 8 ) has corrugations with a rectangular profile. The mesh ( 8 ) can be substituted by an expanded sheet or by a perforated sheet. The voids in the corrugation are filled with the filler ( 3 ) of the cladding ( 1 ) (the filler is not shown in the plan view). The upper surface of the mesh ( 8 ) serves as a first heat collecting/dispersing layer ( 4 ) and the lower surface of the mesh ( 8 ) serves as a second heat collecting/dispersing layer ( 5 ). The mesh ( 8 ) constitutes a uniform array of seamless rectangular thermal bridges across the panel ( 1 ).
[0474] FIG. 3 b : cross-section of panel ( 1 ) with embedded rectangular corrugated mesh ( 8 ).
[0475] FIG. 4 a : plan view: array of L-shaped strips ( 9 ).
[0476] L-shaped strips ( 9 ) of aluminum sheet are bonded to a lower layer ( 6 ): in the example of plasterboard, this layer ( 6 ) can be paper. The strips are shown with perforations to assist cohesion with the moldable filler ( 3 , not shown)
[0477] FIG. 4 b : cross-section of array of L-shaped strips ( 9 ) before moldable filler ( 3 ) is added. The lower portions of the L-shaped strips ( 9 ) are the second heat collecting/dispersing layer ( 5 ).
[0478] FIG. 4 c : cross-section: L-shaped strips ( 9 ) embedded in a molded panel ( 1 ) and bent into a rectangular reverse C shape.
[0479] The upper portions of the strips ( 9 ) are laminated against the top surface of the panel ( 1 ). The upper portions of the L-shaped strips ( 9 ) are a first heat collecting/dispersing layer ( 4 ). The lower portions of the L-shaped strips ( 9 ) are a second heat collecting/dispersing layer ( 5 ). The folded C-shaped strips form a uniform array of seamless rectangular thermal bridges across the panel ( 1 )
[0480] FIG. 4 d : cross-section: L-shaped strips ( 9 ) embedded in a molded panel ( 1 ) and bent into a rectangular S shape.
[0481] The upper portions of the strips ( 9 ) are laminated against the top surface of the panel ( 1 ). The upper portions of the L-shaped strips ( 9 ) are a first heat collecting/dispersing layer ( 4 ). The lower portions of the L-shaped strips ( 9 ) are a second heat collecting/dispersing layer ( 5 ). The folded S-shaped strips form a uniform array of seamless rectangular thermal bridges across the panel ( 1 )
[0482] FIG. 5 a : plan view: section of aluminum sheet ( 10 ) with pattern ( 11 ) of slits for flaps ( 13 ).
[0483] An aluminum sheet ( 10 ) has a uniform array of pairs of slits ( 11 ). Each pair of slits ( 11 ) has a linking cut ( 12 ) across one end.
[0484] FIG. 5 b : perspective view: individual raised flap ( 13 ).
[0485] A flap ( 13 ) between each pair of slits ( 11 ) in an aluminum sheet ( 10 ) is lifted to a vertical position. A uniform array (not shown) of such flaps ( 13 ) can be used in the same way as the L-shaped strips ( 9 ) (see FIGS. 4 a to 4 d ) to form a uniform array of seamless rectangular thermal bridges across a panel ( 1 ).
[0486] FIG. 5 c : plan view: section of aluminum sheet ( 10 ) with pattern ( 14 ) of slits for loops ( 15 ).
[0487] An aluminum sheet ( 10 ) has a uniform array of pairs of slits ( 14 ).
[0488] FIG. 5 d : perspective view: individual raised rectangular loop ( 15 ).
[0489] The sheet between each pair of slits ( 14 ) is pushed up to form a rectangular loop ( 15 ). An array (not shown) of such loops ( 15 ) can be embedded in a molded panel ( 1 ) (not shown) to form a uniform array of seamless rectangular thermal bridges.
[0490] FIG. 6 a : cross-section: wrapped separate sections ( 16 ) of cladding panel ( 1 ).
[0491] Cladding panel ( 1 ) is divided into two sections ( 16 ). A aluminum sheet ( 10 ) is wrapped fully round each section ( 16 ) and bonded to each section ( 10 )
[0492] FIG. 6 b : cross-section: wrapped sections ( 16 ) of panel ( 1 ) joined together.
[0493] Two sections ( 16 ) of panel ( 1 ) are bonded together. The wrapped aluminum sheet ( 10 ) constitutes seamless rectangular thermal bridges across the panel ( 1 )
[0494] FIG. 6 c : cross-section: wrapped sections ( 16 ) of panel ( 1 ) joined together with a ceramic shunt ( 17 ).
[0495] A molded porcelain thermal shunt ( 17 ) is bonded between the sections ( 16 ).
[0496] The number and width of sections ( 16 ), the thickness of the wrapping layer ( 10 ) and the material and geometry of the shunt ( 17 ) can all be varied.
[0497] FIG. 7 a : perspective view: single fiberboard cuboid ( 18 ) wrapped in rectangular aluminum spiral ( 7 )
[0498] Cuboids ( 18 )—rods of fiberboard with a rectangular cross-section—are formed in a shaped hot press (not shown). The cuboids are wrapped in a rectangular aluminum spiral ( 7 ).
[0499] FIG. 7 b : cross-section: cuboids ( 18 ) embedded in pre-press mat ( 19 ).
[0500] Fiberboard cuboids ( 18 ) wrapped in aluminum spiral ( 7 ) are arranged in a uniform array on a forming platform ( 20 ) with gaps ( 21 ) between the cuboids ( 18 ).
[0501] FIG. 7 c : cross-section: cuboids ( 18 ) embedded in panel ( 1 ).
[0502] During pressing, the pre-press mat ( 19 ) flows into the gaps ( 21 ) between the cuboids ( 18 ).
[0503] The result is a uniform array of seamless rectangular thermal bridges across the panel.
[0504] FIG. 8 a : cross-section: array of circular spirals ( 22 ) filled with pre-press mat ( 19 ).
[0505] An array of aluminum spirals ( 22 ) (two are shown) of circular cross-section is filled with the pre-press mat ( 19 ).
[0506] FIG. 8 b : cross-section: array of spirals deformed into ovoid spirals ( 23 ) in panel ( 1 ).
[0507] During hot-pressing, the pre-press mat ( 19 ) is compressed by a ratio of 5-10×. Adjacent circular spirals ( 22 ), filled with fibers, are deformed by pressure into flat ovoid spirals ( 23 ) and fixed by curing of a binding agent. The ovoid spirals ( 23 ) are forced into contact. A series of parallel flat ovoid spirals ( 23 ) constitute a uniform array of seamless, rectangular thermal bridges across the panel ( 1 ).
[0508] FIG. 8 c : perspective view: circular spirals ( 22 ) in vertical arrangement for three-ply panel ( 1 ).
[0509] A pre-press mat ( 19 ) for an OSB panel comprises three layers ( 24 ) of circular spirals ( 22 ) (single spirals shown) each filled with wood strands ( 24 , not shown) that are generally oriented along the axes of each spiral ( 22 ). Spirals ( 22 ) in each layer ( 24 ) are arranged in a uniform planar array (not shown) at right angles to spirals ( 22 ) in adjacent layers ( 24 ).
[0510] During hot-pressing, the spirals ( 22 ) deform into ovoid spirals ( 23 , not shown), are pressed forcefully against adjacent spirals ( 22 ), are fixed in place by curing of a binding agent and form a uniform array of effectively seamless, near-rectangular thermal bridges across the panel ( 1 ).
[0511] FIG. 8 d : cross-section: curved aluminum mesh trough ( 26 ) filled with wood strands ( 25 ).
[0512] A curved trough ( 26 ) is made by folding perforated aluminum sheet, for example, flattened expanded aluminum mesh. The trough ( 26 ) is filled with wood strands ( 25 ), with the strands ( 25 ) generally aligned with the longer dimension of the trough ( 26 ).
[0513] FIG. 8 e : cross-section: curved aluminum mesh trough ( 26 ) folded to form cylinder ( 27 ).
[0514] The curved trough ( 26 ) shown in FIG. 8 d is folded over to form a perforated aluminum cylinder ( 27 ). A uniform array of such pre-filled cylinders ( 27 ) is placed on the forming platform (not shown). During hot pressing, the cylinders ( 27 ) deform into cylinders with a flat ovoid cross-section (not shown). The flattened cylinders (not shown) are fixed in place by curing of a binding agent and form a uniform array of effectively seamless, rectangular thermal bridges across the layer (not shown). Pre-filled cylinders ( 27 ) can be used to thermally bridge three-layer OSB using the arrangement described in FIG. 8 c.
[0515] FIG. 9 a : plan view: single cross-shaped cut ( 28 ) in sheet ( 10 ).
[0516] An aluminum sheet ( 10 ) is cut with a staggered pattern (not shown) of cross-shaped cuts ( 28 ).
[0517] FIG. 9 b : perspective view: teeth ( 29 ) raised from single cross-shaped cut ( 28 ).
[0518] The cross-shaped cuts ( 28 ) in the aluminum sheet ( 10 ) are pushed up to form an array (not shown) comprising four teeth ( 29 ) from each cross-shaped cut ( 28 ). The sheet ( 10 ) and the array of teeth ( 29 ) comprise a penetrating pressed sheet ( 42 , not shown).
[0519] FIG. 9 c : plan view: single H-shaped cut ( 30 ) in sheet ( 10 ).
[0520] An aluminum sheet ( 10 ) is cut with a staggered pattern (not shown) of H-shaped cuts ( 30 ).
[0521] FIG. 9 d : perspective view: straight edges ( 31 ) raised from H-shaped cut ( 30 ).
[0522] The H-shaped cuts ( 30 ) in the aluminum sheet ( 10 ) are pushed up to form an array (not shown) comprising two edges ( 31 ) from each H-shaped cut ( 30 ). The sheet ( 10 ) and the array of edges ( 31 ) comprise a penetrating pressed sheet ( 42 , not shown).
[0523] FIG. 9 e : plan view: single H-shaped cut with slanted cross cut ( 32 ) in sheet ( 10 )
[0524] An aluminum sheet ( 10 ) is cut with a staggered pattern (not shown) of H-shaped cuts with slanted cross cut ( 32 ).
[0525] FIG. 9 f : perspective view: guillotine edges ( 33 ) raised from slanted H-shaped cut ( 32 ).
[0526] The H-shaped cuts ( 32 ) in the aluminum sheet ( 10 ) are pushed up to form an array (not shown) comprising two guillotine edges ( 33 ) from each H-shaped cut ( 32 ). The sheet ( 10 ) and the array of edges ( 33 ) comprise a penetrating pressed sheet ( 42 , not shown).
[0527] FIG. 9 g : plan view: single H-shaped cut with zigzag cross cut ( 34 ) in sheet ( 10 ).
[0528] An aluminum sheet ( 10 ) is cut with a staggered pattern (not shown) of H-shaped cuts with zigzag cross cut ( 34 )
[0529] FIG. 9 h : perspective view: saw-tooth edges ( 35 ) raised from H-shaped cut with zigzag cross cut ( 34 ).
[0530] The H-shaped cuts ( 34 ) in the aluminum sheet ( 10 ) are pushed up to form an array (not shown) comprising two saw-toothed edges ( 35 ) from each H-shaped cut ( 34 ). The sheet ( 10 ) and the array of edges ( 35 ) comprise a penetrating pressed sheet ( 42 , not shown).
[0531] FIG. 9 i : plan view: single V-headed cut at the end of parallel cuts ( 36 ) in sheet ( 10 ).
[0532] An aluminum sheet ( 10 ) is cut with a staggered pattern (not shown) of V-headed cuts at the end of parallel cuts ( 36 ).
[0533] FIG. 9 j : perspective view: aluminum sheet ( 10 ) with single raised V-headed member ( 37 ).
[0534] The V-headed cuts ( 36 ) in the aluminum sheet ( 10 ) are pushed up to form an array (not shown) comprising a V-headed member ( 37 ) from each V-shaped cut ( 36 ). The sheet ( 10 ) and the array of V-headed members ( 36 ) comprise a penetrating pressed sheet ( 42 , not shown).
[0535] FIG. 10 a : cross-section: single raised V-headed member ( 37 ) penetrating hot-pressed panel ( 1 ) and resilient felt layer ( 39 ).
[0536] Arranged on a forming platform ( 20 ) is a penetrating pressed sheet ( 42 ) with a uniform array of V-headed members pointing upwards ( 37 , one only shown). Above the pressed sheet ( 42 ) are layers in the following sequence: a compressed panel ( 1 ), a plain aluminum sheet ( 10 ), a layer of resilient wool or mineral felt ( 39 ) and a plate of hardened steel ( 43 ). The cross-section shows the result of hot pressing. A mat ( 19 , not shown) has been compressed to form the panel ( 1 ). The V-headed member ( 37 ) has penetrated the panel, including the aluminum sheet ( 10 ) and also the felt ( 39 ).
[0537] FIG. 10 b : cross-section: single raised V-headed member ( 37 ) folded and laminated to aluminum sheet ( 10 ).
[0538] The press has been released, the felt layer ( 39 , not shown) has been peeled off the projecting V-headed member ( 37 ). The remaining layers have been compressed again so that the V-headed member ( 37 ) has been folded over and laminated against the aluminum sheet. ( 10 )
[0539] FIG. 11 a : plan view: staggered pattern ( 41 ) of H-shaped cuts ( 30 ) on aluminum sheet ( 10 ).
[0540] The pattern of cuts ( 41 ) is staggered so that the penetrating pressed sheet ( 42 ) is less likely to weaken the panel ( 1 )
[0541] FIG. 11 b : cross-section: penetrating pressed sheet ( 42 ) on pre-press mat ( 19 ).
[0542] A pre-pressed mat ( 19 ) is formed upon an aluminum sheet ( 10 ) that is placed on a steel plate ( 43 ), preferably made of hardened, wear-resistant steel. A penetrating pressed sheet ( 42 ) bearing an array of penetrating members ( 44 ) is placed on the top of a pre-press mat ( 19 ) with the members ( 44 ) facing downwards.
[0543] FIG. 11 c : cross-section: penetrating pressed sheet ( 42 ) embedded in panel ( 1 ).
[0544] During hot pressing, the penetrating members ( 44 ) are driven through the mat ( 19 ), come into forceful contact with the lower aluminum sheet ( 10 ) and are fixed in pace by curing of a binding agent. The steel plate ( 43 ) allows the penetrating members ( 44 ) to fully penetrate the aluminum sheet ( 10 ) without damage to the press (not shown). As a result a uniform array of effectively seamless, rectangular thermal bridges is formed across the panel ( 1 ).
[0545] FIG. 12 a : cross-section: engineered wood floorboard ( 45 ) without thermal bridge.
[0546] An engineered floorboard ( 45 ) has an upper hardwood layer ( 46 ), a central core layer ( 47 ) and a lower stabilizing layer ( 48 ). The edges ( 49 ) of the floorboard ( 45 ) are shaped so that adjacent boards ( 45 ) interlock. The simplest interlock—tongue and groove—is shown. More complex interlock geometries can also be used.
[0547] FIG. 12 b : cross-section: engineered wood floorboard ( 45 ) with lower layers thermally bridged by rectangular spirals ( 7 ).
[0548] An engineered wood floorboard ( 45 ) has a section of the core layer ( 47 ) and a section of the stabilizing layer ( 48 ) replaced by molded wood composite ( 50 ) in which there are embedded thermal bridges: in this case an array of rectangular spirals ( 7 ) of heat-conducting wire or strip, as described in FIGS. 2 a and 2 b . Other embedded thermal bridges described here can be used. The molded wood composite ( 50 ) can also replace all the core layer ( 47 ) including tongue and groove. (this variant not shown).
[0549] FIG. 12 c : cross-section: engineered wood floorboard ( 45 ) with lower layers thermally bridged by a ceramic thermal shunt ( 17 ) and aluminum sheets ( 10 ).
[0550] An engineered wood floorboard ( 45 ) has aluminum sheet ( 10 ) laminated between the upper hardwood layer ( 46 ) and the central core layer ( 47 ) and has aluminum sheet ( 10 ) laminated to the base of the stabilizing layer ( 48 ). The same sheet ( 10 ) is bonded to a ceramic thermal shunt ( 17 ).
[0551] FIG. 12 d : cross-section: engineered wood floorboard ( 45 ) with sections thermally bridged by wrapped sheet.
[0552] An engineered wood floorboard ( 45 ) is the same as shown in FIG. 12 c , except that a continuous aluminum sheet ( 10 ) is wrapped around sections of the core layer ( 47 ) and stabilizing layer ( 48 ). An additional thermal shunt ( 17 ) is omitted but can be included.
[0553] The thermal bridging methods applicable to engineered wood floorboards ( 45 ) are also applicable to laminate flooring (not shown). In laminate flooring the upper hardwood layer ( 46 ) shown in FIGS. 12 a to 12 d inclusive is replaced by a combination of protective and decorative upper layers.
[0554] FIG. 13 a : cross-section: aluminum thread loops ( 51 ) projecting through carpet primary backing layer ( 52 ).
[0555] Primary backing ( 52 ) for tufted or loop carpet comprises a net of fibers (not shown). Aluminum thread is woven through the primary backing layer ( 52 ) and protrudes in an array of loops ( 51 ).
[0556] FIG. 13 b : cross-section: aluminum thread loops ( 51 ) embedded in carpet backing cement ( 53 ) and folded against the secondary backing layer ( 54 ).
[0557] Laminated to the primary backing layer ( 52 ) is a layer of backing cement ( 53 ), for example, latex. The cement ( 53 ) anchors yarn (not shown), that has been pushed through the primary backing layer ( 52 ) and bonds to the secondary backing layer ( 54 ), which also comprises a net of fibers, including aluminum thread (not shown). The loops ( 51 ) are folded against the secondary backing layer ( 54 ). The loops ( 51 ) constitute thermal shunts, the primary backing ( 52 ) is the heat-dispersing layer, and the secondary backing ( 54 ) is the heat-collecting layer. In combination, the primary backing ( 52 ), the loops ( 51 ) and the secondary backing ( 54 ) constitute a distributed array of approximately rectangular thermal bridges.
[0558] FIG. 13 c : cross-section: aluminum granules ( 55 ) embedded in carpet backing cement ( 53 ).
[0559] The primary backing layer ( 52 ) and the secondary backing layer ( 54 ) both include aluminum thread (not shown). Heat-conducting spherical granules ( 55 ) are dispersed uniformly in the cement ( 53 ). The diameter of the granules ( 55 ) is slightly less than the overall width of the backing so that the granules ( 55 ) dispersed in the cement ( 53 ) provide a direct thermal path through the backing cement ( 53 ) between the two backing layers ( 52 , 54 ), creating a distributed array of effectively rectangular thermal bridges across the carpet backing.
SCOPE OF INVENTION
[0560] A number of embodiments of thermal bridging are described here, with reference to particular forms of interior cladding and in general preferring aluminum as material for thermal bridges. It is envisaged that various details of the invention may be modified without departing from the spirit and scope of the invention. For example, other variants of interior cladding and other materials for thermal bridging can be considered to be within the scope of the invention. The foregoing descriptions of alternative embodiments of the invention are for illustration and not for the purpose of limitation. | The efficiency of radiant space heating or cooling is improved and the use of renewable energy sources enabled by reducing the resistance of the thermal path through cladding used in the floor, walls or ceiling of a domestic or commercial living space. The resistance of the thermal path is reduced by constructing the cladding with an array of thermal bridges each comprising a thermal shunt connected to a heat-collecting layer and to a heat-dispersing layer. Such bridged cladding extends the range of choice of interior cladding and of configuration of radiant system. | 4 |
BACKGROUND OF THE INVENTION
1. Field
The present invention relates to thin compact absorbent incontinence pads and more particularly to absorbent incontinence pads to be applied onto the crotch region of a user for dealing with his or her light incontinence. The term “incontinence pads” is herein used to collectively refer to absorbent articles for incontinence uses and includes all articles generally called absorbent sheets, absorbent liners or absorbent cards. Also, for the sake of simplicity in designing articles according the amounts of urination, the term “light incontinence” is herein used generally as a term referring to 250 cc or less as the amount of urination, as opposed to the term “serious incontinence,” which generally refers to greater amounts of urination.
2. Related Art
In recent years, sanitary goods designed to address adult light incontinence have drawn much market attention, and many companies have actively joined the competition of developing such goods. Symptoms of light incontinence are more often observed with females: the degree of incontinence varies from extremely light (15 cc or less) to medium light (approximately 200 cc), and the age group of those suffering from such symptoms varies widely from the 20's to the 50's. Until now, there have been very few goods designed specifically to deal with adult light incontinence symptoms, and other articles, such as sanitary napkins and panty shields have been used as substitutes.
Articles such as sanitary napkins and panty shields, which were originally designed to deal with menstrual blood, cause many problems when they are used to address urinary incontinence. Articles designed and manufactured to address light urinary incontinence using wood pulp as the absorbent member have also been found to cause many problems.
One problem that articles currently used to treat adult light incontinence have is with leakage and discomfort, typically manifested as a sticky feeling, because they provide insufficient absorbance and performance. One cause of these and other problems is that in baby diapers and adult incontinence diapers one critically important feature is the ability to rapidly absorb large amounts of liquid exudates discharged at one time. This is known as the acquisition effect. In contrast, articles designed for light incontinence symptoms, must be able to efficiently and effectively handle liquid exudates which are usually discharged in small amounts and at more frequent intervals. Adult light incontinence articles which are designed based on baby diapers and adult incontinence diaperstypically use wood pulp fluff as their main component. When used to address adult light incontinence, the wood pulp fluff remains wetted on the surface, causing the skin of the wearer, which is in contact with the absorbent member, to erupt in a rash or become inflamed.
In order to solve such problems, it is preferred to design an adult light incontinence article which takes advantage of the performance of super absorbent polymers (SAP), which are excellent at gelatinizing liquid exudates. It is further preferred that such absorbent member has a high content of SAP, preferably nearly 100% content of SAP.
Another second problem with current absorbent articles is that the absorbent member remains wetted during use. To address this issue, it is critically important to create an absorbent member with an air permeable structure so that it remains breathable during use and does not become uncomfortably stuffy. In order to achieve such a structure, not only must the components such as the topsheet (surface sheet) and backsheet be air permeable, but the absorbent member itself musthave an air permeable structure.
A third problem that must be addressed by an adult light incontinence article is that those who suffer from light incontinence symptoms typically experience such symptoms unpredictably, instantaneously and at times of temporary physical tension or high stress. For example, light incontinence often results from changes in abdominal pressure caused by normal pregnancy, or by sneezing, sudden laughter, or physical exertion such as jumping. In other words, such symptoms are very often observed with those females who live normal and healthy life. It is therefore a very important that an incontinence article can be worn as inconspicuously as possible and has a very thin and compact form so that it additional or spare articles can be carried in a handbag or pocket.
A fourth problem that must be addressed by an incontinence article is that users come in a great variety of shapes and sizes. An absorbent article must have three-dimensional adaptability which can accommodate any difference in shape of the body region of a wearer on which it is applied.
The object of the present invention is to provide an absorbent incontinence pad satisfying all of the above-mentioned requirements.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided an absorbent incontinence pad comprising:
an absorbent unit comprising a non-woven fabric substrate, an absorbent zone consisting of a plurality of highly absorbent layer elements extending in the form of bands on the surface of the non-woven fabric substrate, and an air permeable zone abutting the non-woven fabric substrate formed in the area where the highly absorbent layers are not formed;
a back sheet wrapping the absorbent unit leaving part of a surface of the absorbent unit uncovered; and
an acquisition layer disposed on the surface of the absorbent unit covering at least part of the uncovered surface thereof.
Furthermore, the absorbent unit may be wrapped with a dispersion layer. In this case, it is preferable that an acquisition layer be disposed on the dispersion layer, covering at least part of the uncovered surface of the absorbent unit.
According to another aspect of the present invention, there is provided an absorbent incontinence pad comprising a topsheet consisting of a liquid pervious and air permeable sheet material and a liquid impervious and air permeable backsheet and an absorbent unit disposed between the topsheet and the backsheet. In this aspect of the invention, the absorbent unit is comprised of a non-woven fabric substrate, an absorbent zone formed by a plurality of highly absorbent layers extending in bands on the surface of the non-woven fabric substrate and an absorbent sheet having an air permeable zone in which no such highly absorbent layers exist.
The topsheet and backsheet can be bonded to each other around their perimeter so that a space is formed between the two sheets, and the absorbent unit can be located within this space.
The absorbent unit can be formed of a first absorbent sheet and a second absorbent sheet being folded on each other. In this structure, the first absorbent sheet may be made with highly absorbent layers in several absorbent zones. The second absorbent sheet may be constructed to have one or more highly absorbent layers in positions corresponding to one or all of the absorbent zones of the first absorbent layer.
In one embodiment, the absorbent unit has two absorbent zones. The first absorbent zone may be located in the central region of the first absorbent sheet, and the second absorbent zone being located in the laterally outboard regions of the first absorbent sheet. In such a configuration, it is preferable for the ratio of the width of the first absorbent zone (Aw) to the width of the second absorbent zone (Bw) (Aw:Bw) to be between 1:0.3 to 2.
It is preferred that the highly absorbent layer be made mostly from a super absorbent polymer. It is also preferred that the highly absorbent layer be divided into a plurality of sections or bands.
In addition, the non-woven fabric substrate of the absorbent sheet may be bonded to other elements of the absorbent incontinence pad in the air permeable zone. For example, the non-woven fabric substrate may be bonded to the topsheet, the backsheet, a dispersion sheet or other layers of absorbent sheets. Such bonding can be done by any number of appropriate means, such as adhesive bonding and heat seal bonding.
In addition, the topsheet, the backsheet, the absorbent unit and their component elements can be made of degradable materials.
One benefit of an absorbent incontinence pad manufactured according to the present invention is that it provides good air permeability through the pad, and provides extremely high absorbency. Such a pad provides very comfortable use, and prevents the humidity and body temperature of the user from rising when worn.
Another benefit of an absorbent incontinence pad manufactured according to the present invention is that the components, such as the top sheet, back sheet, absorbent unit, can be made of degradable material. Such a pad can be disposed of in a toilet without clogging the toilet system. Such a pad can also be disposed of by biodegradation or other types of degradation without causing a severe environmental impact.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing an absorbent incontinence pad in a first embodiment of the present invention;
FIG. 2 is a schematic cross-sectional view taken along section line A—A of FIG. 1;
FIG. 3 is a plan view showing an embodiment of an absorbent unit in the absorbent incontinence pad of FIG. 1;
FIG. 4 is a schematic cross-section view showing an absorbent incontinence pad in a second embodiment of the present invention;
FIG. 5 is a schematic cross-section view of an embodiment of an absorbent unit to be used in an absorbent incontinence pad shown in FIG. 4;
FIG. 6 is a schematic cross-sectional view showing an absorbent incontinence pad in the form of a third embodiment of the present invention;
FIG. 7 is a schematic cross-sectional view showing an absorbent incontinence pad in the form of a fourth embodiment of the present invention;
FIG. 8 is a schematic cross-section view showing an absorbent incontinence pad in the form of a fifth embodiment of the present invention;
FIG. 9 is a longitudinal cross-sectional view showing the structure of an embodiment of an absorbent unit to be applied to the present invention;
FIG. 10 is a longitudinal cross-sectional view showing the structure of another embodiment of an absorbent unit to be applied to the present invention;
FIG. 11A is a longitudinal cross-sectional view showing the structure of another embodiment of an absorbent unit to be applied to the present invention;
FIG. 11B is a longitudinal cross-sectional view showing the structure of still another embodiment of an absorbent unit to be applied to the present invention; and
FIG. 12 is a longitudinal cross-sectional view showing the structure of yet another embodiment of an absorbent unit to be applied to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the present invention will be described with reference to the accompanying drawings below:
FIG. 1 shows an embodiment of the present invention in the form of an absorbent incontinence pad designed for a small amount of urine. In FIG. 1, reference number 1 refers to a top sheet and 2 refers to a back sheet. The top sheet 1 , is made from a sheet of material, such as porous non-woven fabric or perforated film, which is highly liquid pervious and air permeable. The back sheet 2 is preferably made from film which is porous and through which air or steam can pass, but moisture cannot pass, or a laminate comprised of one or more layers of such a film bonded with one or more layers of non-woven fabric. Alternatively, the back sheet 2 can be comprised of a water resistant laminate of non-woven fabrics of polyethylene or polypropylene, such as a spunbonded-meltblown-spunbonded (S.M.S.) or spunbonded-meltblown-meltblown-spunbonded (S.M.M.S.) fabrics, which are well known in the art. In such a construction, a film, as described before, may not be necessary.
The top sheet 1 and back sheet 2 have at their periphery edges 3 formed by an appropriate means, such as heat sealing or ultrasonic sealing. In addition, an absorbent unit 4 is interposed between the top sheet 1 and the back sheet 2 . In one embodiment of the claimed invention, the main absorbent zone in the center of the top sheet 2 may be provided with embossed lines to improve its three-dimensional structure.
Referring now to FIGS. 2 and 3, in one embodiment of the claimed invention, an absorbent unit 4 may be comprised of an approximately rectangular non-woven fabric substrate 5 , which faces the back sheet 2 in this example, located adjacent to a highly absorbent region comprised of a plurality of strands of highly absorbent layers 6 , four of which are shown in this example. Between the highly absorbent layer strands 6 there are gaps, which expose the non-woven fabric substrate 5 . In this embodiment, the absorbent unit 4 has absorbent zones formed by the highly absorbent layers 6 and zones containing no highly absorbent layers 6 , which separate the highly absorbent layers 6 and form an air permeable zone that allows air to flow to the non-woven fabric substrate 5 .
The highly absorbent layers 6 are preferable comprised primarily of super absorbent polymer (SAP). In order to obtain as much compactness and absorbency as possible, the highly absorbent layers 6 should have as high a content of SAP as possible, preferably 60% or higher. Such highly absorbent layers 6 can be easily formed on a commercial scale, as described in JPA H10-168230, by applying a dispersion liquid in which particulate super absorbent polymer is deposited on the surface of a non-woven fabric using a device known as a line coater.
In a preferred embodiment of the claimed invention, a dispersion sheet 7 is interposed between the absorbent unit 4 and the top sheet 1 . The dispersion sheet 7 is comprised of a liquid pervious non-woven fabric of approximately the same size as the absorbent unit 4 . The dispersion sheet 7 traps liquid passing through the top sheet 1 and disperses the liquid in all directions. The dispersion sheet 7 , also called an acquisition layer, can be made larger or smaller than the absorbent unit 4 , and should preferably be more concentrated in the center zone. Similarly, in a preferred embodiment a piece of tissue 8 may be interposed between the absorbent unit 4 and the back sheet 2 . The tissue 8 improves the dispersion of the liquid and improves the dimensional stability of the absorbent incontinence pad. Alternatively, in the case of an absorbent incontinence pad for an extremely small amount of urine, the structure can be made simpler by omitting the dispersion sheet 7 and tissue 8 .
Although in the previous embodiment the dispersion sheet 7 is between the absorbent unit 4 and the top sheet 1 , this configuration may be reversed such that the top sheet 1 is between the acquisition sheet 7 and the absorbent unit 4 . Alternatively, as shown in FIGS. 7 and 8, the top sheet may be omitted and replaced by the acquisition layer 7 ′. Such an embodiment provides an advantage in that the absorbent unit can swell without the upper portion being restrained by the top sheet 1 . An acquisition layer for such purposes is preferably a bulky sheet having a weight of approximately 30 g/m 2 or compressed member of such material. For example, a bulky perforated film having a embossed thickness as high as 1184μ (such as that manufactured and sold by Tredegar under the trademark of “X-27373”) can be used. Also, a compressed sheet of cellulose sponge of about 100 g/m 2 or a bulky non-woven fabric made of hollow bicomponent fiber and having a density of about 50 g/m 2 may also be used.
In the present invention, a highly absorbent layer strips 6 are layers containing a super absorbent polymer (SAP). The super absorbent polymers are high polymer materials which can absorb a high volume of water per unit weight of SAP, and generally includes carboxymethyl cellulose, polyacrylic acid and its salts, cross-linked acrylate polymers, starch-acrylic acid graft copolymers, hydrolytes of starch-acrylonitrile graft copolymers, cross-linked polyoxyethylene, cross-linked carboxymethyl cellulose, partially cross-linked water swellable polymers such as polyethylene oxide and polyacrylamide, and isobutylene-maleic acid copolymers. By drying any such polymer, a particulate base polymer can be obtained. After drying, an after treatment is usually further applied to increase the cross-linked density of the surface of the polymer particles, and at the same time, an antiblocking agent is added to prevent the blocking of product particles due to absorption of moisture.
An absorbent incontinence pad structured in accordance with the present invention can, by means of the high absorbancy of super absorbent polymer contained in the highly absorbent layers 6 of the absorbent unit 4 , effectively absorb liquid discharged repeatedly and in small amounts, and at the same time maintain the surface of the top sheet 1 in a dry condition. Also, because the absorbent unit 4 has an air permeable zone between the highly absorbent layers 6 , exposing the non-woven substrate 5 to air flow, the surface of the top sheet 1 is further assisted in maintaining a dry state. Also, the air permeable zone can also easily bend and deform uniformly, allowing the absorbent article to deform three-dimensionally to match the contours of the wearer's body. Furthermore, the air permeable zone can also serve as a liquid passage to effectively and rapidly distribute discharged liquid to the surfaces of the highly absorbent layers 6 .
Since an absorbent light incontinence pad made according to the present invention may be discarded by being flushed down a toilet or discarded in the trash, it is preferred that a biodegradable SAP be used in the article. Biodegradable SAPs are known in the art, such as cross-linked polyolefin, cross-linked carboxymethyl cellulose (as described in the specification of Gelman U.S. Pat. No. 4,650,716), cross-linked alginic acid, crosslinked starch, cross-linked and polyamino acid. Also, by manufacturing the highly absorbent layers 6 with a combination of super absorbent polymer and microfibrillated-fibril-formed cellulose, a structure which may have higher absorbing rate can be obtained.
In the present invention an important component of the absorbent unit 4 is the non-woven fabric substrate 5 . The non-woven fabric substrate is may be comprised of what are generally called “non-woven fabrics,” such as wet process and dry process spun bonded and spun laced non-woven fabrics. It is preferred that the non-woven fabrics used in the present invention are as bulky as possible, such as spun laced non-woven fabric obtained by entangling carded web in the stream of water and thermally bonded non-woven fabric obtained by thermally bonding carded web. Also, in order to provide a degradable absorbent unit, as combined with the above-mentioned biodegradable SAP, it is preferred that a biodegradable cellulosic non-woven fabric or a non-woven fabric, collapsible in water containing Ca salt of CMC, be selected as the non-woven fabric substrate 5 .
It should be understood that the term “degradable absorbent unit” means not merely a degradable absorbent unit but also includes such absorbent units as are collapsible in water, biodegradable, decomposable in compost or decomposable in soil. It should also be understood that, although a degradable absorbent unit 4 has been described herein, an absorbent incontinence pad, as a whole, can be made degradable by appropriately selecting top sheet and back sheet material. For example, an entirely water-collapsible absorbent incontinence pad can be constructed by using an absorbent unit made of water collapsible material, a the top sheet made of non-woven fabric that is collapsible in water, and a back sheet made of material such as partially cross-linked P. V. A. film. Such a water-collapsible pad can be disposed of by flushing it down a toilet.
The following definitions apply to terms that are used in the present invention:
The term “collapsible in water or water-collapsible” means that a component material collapses easily in water in a flush toilet and is capable of dispersing in sufficient fineness so that it does not cause any clogging in a pipe or the like.
The term “biodegradable” means that a component material is decomposed into a safe low molecular weight material by the action of living organisms such as microorganisms, fungi, and enzymes in a natural environment or under artificially controlled conditions such as those for making composts.
The term “degradable in compost” means that a component material is decomposed into a safe low molecular weight material by the action of living organisms such as microorganisms, fungi, and enzymes in compost. For example, when 1 weight part (in dry state) of a degradable absorbent unit is made into 100 weight parts (in wet state) of inoculum of compost and processed at 58 degrees Celsius for 40 days, the dry weight of the degradable absorbent unit after being thus processed is reduced to 0% to 50 of the original dry weight of the degradable absorbent unit.
The term “decomposable in soil” means that a component material is biologically decomposed into a safe low molecular weight material by the action of microorganisms, fungi, or enzymes in soil when it is, for example, buried in soil. For example, when 1 weight part (in dry state) of a degradable absorbent unit is processed by being buried at 300 cm below the ground level of an agricultural field for six months, the dry weight of the degradable absorbent unit after being thus processed is reduced to 0% to 50% of the original dry weight of the degradable absorbent unit.
All of the aforementioned terms are understood to be used interchangeably for the purposes of this invention. Furthermore, and as stated before, all of the terms are included in the definition of the general term: “degradable.”
A second embodiment of a regular type absorbent incontinence pad as structured according to the present invention is explained with reference to FIG. 4 . In this embodiment, a dispersion sheet 7 is interposed in the space between the top sheet 1 and the back sheet 2 . Similarly, a piece of tissue 8 is disposed in the space between an absorbent unit 4 and the back sheet 2 . The dispersion sheet 7 and the tissue 8 are located to improve the dispersion of liquid and the dimensional stability of the absorbent incontinence pad as a whole. This structure is similar to the first embodiment as shown in FIGS. 1 through 3, but is different in several respects. One difference is that a fringe member 10 is bonded on the peripheral edge 3 of the back sheet 2 , and an elastic member 11 is attached to the inner peripheral edge of the fringe member 10 such that the fringe member 10 stands up towards the inside.
The absorbent unit 4 , of FIG. 4 is depicted in FIG. 5 . The absorbent unit 4 has a nearly rectangular non-woven fabric substrate 5 . A first absorbent zone A is adjacent to the center region of the non-woven fabric substrate 5 . The first absorbent zone A is comprised of three parallel highly absorbent layer strands 6 spaced by narrow air permeable zones C 1 . A pair of second absorbent zones B comprised of highly absorbent layers 6 are situated on both sides of the first absorbent zones A with the highly absorbent layers 6 placed in parallel with those of the first absorbent zone A. Wider air permeable zones C 2 separate the second absorbent zones B from the first absorbent zones A.
The ratio of the width of a first absorbent zone A (Aw) to the width of a second absorbent zone B (Bw), (Aw:Bw), is preferably in the range of 1:0.3 to 2 and more preferably in the range of 1:0.7 to 1.0. Also, it is preferred that the air permeable zone C 2 separating the first and second absorbent zones A and B occupies 10% or more of the total area of the absorbent unit and more preferably 15% to 50%.
By placing the first absorbent zone A in the center and the second absorbent zones B on both sides of the first absorbent zone A, it is easier to impart different absorbency properties in each zone and easier to tailor products having properties that meet various application requirements. At the same time, this embodiment provides for a structures that can easily be intentionally changed in form.
Furthermore, under conditions in which an absorbent incontinence pad will be wetted after an act of incontinence, the air permeable zones C 1 and C 2 function to impart excellent air permeability to the absorbent incontinence pad, preventing the pad from becoming hot, stuffy, or otherwise uncomfortable.
Referring back to FIG. 4, a heat seal 9 links the absorbent unit 4 to other elements, such as the dispersion sheet 7 , the tissue 8 , the top sheet 1 , and the back sheet 2 , and integrates all of these elements. Thus integrated, the absorbent unit 4 is secured in place and the absorbent unit 4 and the absorbent incontinence pad maintain their initial shape. Also, this heat seal 9 provides a passage through which liquid moves up and down and specifically functions as a short passage for the liquid moving from the top sheet down to the piece of tissue layer 8 .
FIG. 6 shows a third embodiment of the present invention in which an absorbent incontinence pad is designed, according to the present invention, to absorb more liquid for longer a period of time. In this example, there are two absorbent units 4 a and 4 b (a dual structure absorbent unit), each having a structure similar to that of the absorbent incontinence pad shown in FIG. 4 . The other elements in FIG. 6 are similar to, and use the same reference numbers as those of the absorbent incontinence pad shown in FIG. 4, and so no explanation of those elements is necessary here.
The embodiment depicted in FIG. 6 exhibits an extremely high absorbent capacity while maintaining outstanding air permeability. In this embodiment, the dispersion sheet 7 is located between the top sheet 1 and the upper non-woven fabric substrate 5 , however, the top sheet 1 may be located between the non-woven fabric substrate 5 and the dispersion sheet 7 .
In another embodiment of the present invention, shown in FIG. 7, two absorbent sheets 4 a and 4 b are connected together by heat seals 9 at two points, and are wrapped with a back sheet 2 having elastic bands 12 and 13 along the periphery thereof in such manner that the upper surface of the uppermost absorbent sheet 4 a is left uncovered. An acquisition layer 7 ′ is disposed on the uppermost absorbent sheet 4 a , covering all or part of the surface left uncovered by the back sheet 2 .
The embodiment shown in FIG. 7 may be modified as shown in FIG. 8 . In FIG. 8, the pair of absorbent sheets 4 a and 4 b are entirely enveloped by a dispersion sheet 14 . As in the previous example, a back sheet 2 having elastic bands 12 and 13 along its periphery is wrapped around the absorbent sheets 4 a and 4 b and the dispersion sheet 14 , leaving a portion of the dispersion sheet 14 exposed. An acquisition layer 7 ′ is located on all or part of the exposed portion of the dispersion sheet 14 .
In the embodiments shown in FIGS. 7 and 8, the top sheet is omitted, and only an acquisition layer 7 ′ is made adjacent to the uppermost absorbent unit 4 a , either directly or via the dispersion sheet 14 . One advantage of such arrangements is that the absorbent unit or units can swell and expand without any restraint caused by the top sheet on the upper surface thereof. In such embodiments, it is preferred that the acquisition layer be made from a bulky sheet having a weight of 30 g/m 2 or more, or a compressed sheet of such a material. Examples of such material include a bulky perforated film having an embossed thickness of 1184μ (such as that manufactured and sold by Tredegar under the trademark of “X-27373”), or a compressed sheet of cellulose sponge having a weight of approximately 100 g/m 2 , or a bulky non-woven fabric made of hollow bicomponent fiber and having a density of about 50 g/m 2 .
Another embodiment of an absorbent unit for use in an absorbent incontinence pad made according to the present invention is shown in FIG. 9 . The embodiment of the absorbent unit in FIG. 5 is comprised of two nearly rectangular non-woven fabric substrates 5 . The uppermost absorbent sheet 4 a is comprised of the upper non-woven fabric substrate 5 , to which an inboard set of four highly absorbent layers 6 are attached, extending in parallel and centered on the substrate. In addition, the uppermost absorbent sheet has an outboard pair of highly absorbent layers 6 , one of which is located on either side of the inboard strands. The lower absorbent sheet 4 b is comprised of a non-woven fabric substrate, attached to which are a pair of outboard highly absorbent layers located in a position corresponding to the positions of the outboard strands attached to the uppermost absorbent sheet 4 a . The absorbent sheets 4 a and 4 b are linked to each other, an possibly to other elements of the article, by means of heat seals 9 .
The embodiment of the absorbent unit depicted in FIG. 9 has a much higher absorbing capacity on either side than in the center. It may also be easily bent or deformed in the portion where the heat seal 9 is located. Such an absorbent unit is able to change shape and conform to the user's body, and is particularly useful in applications in which the user needs to be free from leakage from the sides.
In another embodiment of an absorbent unit depicted in FIG. 10, a first absorbent sheet 4 a has a structure similar to the one shown in FIG. 9 . The second absorbent sheet 4 b has a single highly absorbent layer strand 6 only in the second absorbent sheet's 4 b center portion. The first and second absorbent sheets 4 a and 4 b are linked to each other by means of a heat seal 9 . In this embodiment, the pad exhibits a very high absorbing capacity in the center portion and has a bulky area, also in the center portion, which swells as the absorbent unit absorbs liquid.
In yet another embodiment of an absorbent unit, shown in FIG. 11 a , the absorbent unit is comprised of a first absorbent sheet 4 a and a second absorbent sheet 4 b bonded to each other in the respective center portions of each sheet by means of a heat seal 9 . An absorbent unit of this embodiment becomes swollen on either side of the centerline after it has absorbed liquid, as shown in FIG. 11 B.
In an embodiment in which a heat seal is used, it is a general practice to have a thermally fusible fibrous material in coexistence inside the non-woven fabric substrate 5 . However, in an embodiment in which the non-woven fabric substrate 5 has no thermally fusible material, an adhesive such as a hot melt adhesive may be used to bond the non-woven fabric substrate 5 .
FIG. 10 shows an embodiment of an absorbent unit wherein a first absorbent sheet 4 a and a second absorbent sheet 4 b are bonded to each other by means of a hot melt adhesive layer 10 interposed between the sheets. By such bonding, liquid may much more easily move in the upward and downward directions.
Dual structure absorbent units, such as those depicted in FIGS. 6 to 12 , can be selected and configured to optimize the absorbing capacities and shape conforming abilities of the absorbent pad to meet the requirements of many different applications and user. Although the foregoing explanation has been focused on dual structure absorbent units comprised of two absorbent sheets, it is possible to have a triple structure, with three sheets, or even a quadruple structure of four absorbent sheets in order to obtain higher absorbency capabilities.
Although the embodiments of the present invention that have been discussed have indicated that the non-woven fabric substrate is located on the top with the highly absorbent layers on the bottom, it should be understood that the positional relation between the two may be reversed, such that the substrate is below the strands. Also, in embodiments in which a dual structure absorbent unit is used, the positional relation and orientation of either or both of the two absorbent sheets may be reversed and the highly absorbent layers may be placed such that they face each other, as in FIG. 12 . Furthermore, although in the many embodiments discussed herein the band-like highly absorbent layers have been described as extending in parallel with the longitudinal direction of an absorbent incontinence pad, they can also be designed to extend orthogonally to longitudinal direction of the absorbent incontinence pad. In an embodiment using a dual structure absorbent unit, one set of strands may be parallel with and the other orthogonal to the longitudinal direction of the absorbent incontinence pad.
Although the foregoing explanations have focused on embodiments of absorbent pads for light incontinence, it should be understood that the present invention may be applied to uses ranging from extremely light incontinence pads to baby and adult diapers, by simply changing the dimensions and proportions explained in the embodiments herein. | An absorbent incontinence pad is provided with a liquid impervious air permeable back sheet and an absorbent unit partly covered by the back sheet, wherein the absorbent unit has a non-woven fabric substrate, an absorbent zone formed by a plurality of highly absorbent layers extending in the form of bands on the surface of the non-woven fabric substrate and an air permeable zone where no such highly absorbent layer exists, which has sufficiently adequate properties to meet incontinence requirements and provides a comfortable feeling during use. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The apparatus of the present invention relates to measuring apparatus in general, and more particularly, to measuring apparatus for a refining unit.
SUMMARY OF THE INVENTION
Apparatus, which measures the wax contents of waxy oil, includes a boiling point analyzer receiving waxy oil and providing a signal corresponding to a boiling point of the waxy oil. A gravity analyzer receiving the waxy oil and providing a signal corresponding to the gravity of the waxy oil. A viscosity analyzer receiving the waxy oil and providing a signal corresponding to the viscosity of the waxy oil. A computing circuit receives signals from all the analyzers and provides a signal corresponding to the wax content of the waxy oil in accordance with the signals from the analyzers.
The objects and the advantages of the invention will appear hereafter from a consideration of the detailed description which follows, taking together with the accompanying drawings, wherein two embodiments of the invention are illustrated by way of example. It is to be especially understood, however, that the drawings are for illustration purposes only, and are not to be construed as defining the limits of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of apparatus, constructed in accordance with the present invention for measuring the wax content of waxy oil.
FIG. 2 is a block diagram of another embodiment of apparatus, constructed in accordance with the present invention, for measuring the waxy content of waxy oil.
DESCRIPTION OF THE INVENTION
The wax content W of waxy lubricating oil may be determined from the following equations.
W=C.sub.1 -C.sub.2 /H+C.sub.3 H-C.sub.4 (MW)-C.sub.5 (IP) (1)
ip= (λ) (sg) (2)
λ = [c.sub.6 (50%bp)]/mw (3)
sg=c.sub.7 /(a+c.sub.8) (4)
h=c.sub.9 log.sub.10 log.sub.10 (V+C.sub.10)+C.sub.11 (5)
mw=c.sub.12 +c.sub.13 a-c.sub.14 k-c.sub.15 (a) (k)+c.sub.16 a.sup.2 +c.sub.17 k.sup.2 (6)
l=∛50 %bp/sg (7)
an alternative equation for determining the wax content is
W=C.sub.18 -C.sub.19 (SG)+C.sub.20 H C.sub.21 (MW) (8)
in the foregoing equations C 1 through C 21 are constants; having preferred values of 168.60, 41.8319, 0.08643, 0.16286, 2.6377, 0.5555, 141.5, 131.5, 870, 0.6, 154, 7955.152, 107.0542, 1768.43, 12.14112, 0.3711237, 100.1778, 257.50, 239.206, 0.078178 and 0.10354; W is the wax content of the waxy oil by percent weight, H is the Bell and Sharp viscosity blending value for the temperature at which the viscosity is measured, MW is the average molecular weight of the waxy oil, IP is the internal pressure of the waxy oil, λ is the latent heat of vaporization of the waxy oil, SG is the specific gravity of the waxy oil, A is the API gravity, V is the kinematic viscosity and K is the Watson Characterization factor, and 50% BP is the 50 percent boiling point in degrees Rankin.
Referring to FIG. 1, waxy oil flows through a line 1. Conventional type boiling point analyzer 3, gravity analyzer 5 and viscosity analyzer 7, samples the waxy oil and provides signals E 1 , E 2 and E 3 , respectively, corresponding to the 50 percent boiling point, to the API gravity and to the kinematic viscosity, respectively, of the waxy oil. A logarithmic amplifier 9 provides a signal corresponding to the logarithm of signal E 1 . A multiplier 10 multiplies the signal from amplifier 9 with a direct current voltage E A , corresponding to a vaalue of 1/3, to provide a signal corresponding to 1/3 log 50% BP. A source of direct current voltages provides voltage E A along with voltages E B through E R . The voltage source is not shown for convenience.
The signal from multiplier 10 is provided to an anti-log circuit 11 which provide a signal corresponding to the cube root of the 50 percent boiling point. A multiplier 12 multiplies the signal E 1 with voltage E B , corresponding to the constant C 6 , to provide a signal corresponding to the numerator of equation 3.
Summing means 15 sums signal E 2 with voltage E C corresponding to the constant C 8 . A divider 16 divides voltage E D , corresponding to the constant C 7 , with the signal provided by summing means 15 to provide a signal SG corresponding to the specific gravity of the waxy oil in line 1. A divider 18 divides the signal from circuit 11 with signal SG to provide a signal K corresponding to the Watson characterization factor.
Signal K is multiplied with voltage E E by a multiplier 20 to provide a signal corresponding to C 14 K.
The K signal is effectively squared by multiplier 21 which provides a corresponding signal to another multiplier 22. Multiplier 22 multiplies the signal from multiplier 21 with voltage E F . Multiplier 22 provides a signal corresponding to the term C 17 K 2 in equation 6. A multiplier 23 multiplies the K signal with signal E 2 to provide a signal corresponding to the term [A] [K]. Another multiplier 25 multiplies the signal provided by multiplier 23 with voltage E G . Multiplier 25 provides a signal corresponding to the term C 15 [A] [K]. Summing means 28 sums the signals from multipliers 20, 25 to provide a signal to subtracting means 30.
A multiplier 31 multiplies signal E 2 with voltage E H to provide a signal corresponding to C 13 A in equation 6. Signal E 2 is effectively squared by multiplier 33 to provide a signal to another multiplier 34. Multiplier 34 multiplies the signal from multiplier 33 with voltage E I to provide a signal corresponding to the term C 16 A 2 . Summing means 36 sums the signals from multipliers 22, 31 and 34 with voltage E J to provide a sum signal to subtracting means 30. Subtracting means 30 subtracts the signal provided by summing means 28 from the signal provided by summing means 36 to provide a signal MW corresponding to the average molecular weight of the waxy oil in line 1.
A divider 40 divides the signal from multiplier 12 with the MW signal to provide a signal λ corresponding to the latent heat of vaporization. A multiplier 42 multiplies the λ signal with the SG signal to provide a signal IP corresponding to the internal pressure of the waxy oil.
The MW signal from summing means 30 is multiplied with voltage E K by a multiplier 43 to provide a signal corresponding to the term C 4 [MW] in equation 1. A multiplier 44 multiplies the IP signal with voltage E L to provide a signal corresponding to the term C 5 [IP].
Summing means 48 sums signal E 3 with voltage E M to provide a signal corresponding to the term [V+C 10 ]. The signal from summing means 48 is applied to a logarithmic amplifier 49 whose output in turn is applied to another logarithmic amplifier 50. Amplifier 50 provides a signal corresponding to the term log 10 log 10 [V+C 10 ]. A multiplier 52 multiplies the signal from amplifier 50 with voltage E N , corresponding to the term C 9 in equation (5). Summing means 52 sums the signal from multiplier 52 with the voltage E O corresponding to the term C 11 of equation (5) to provide a signal H corresponding to the term H in equation (5).
A divider 54 divides voltage E P corresponding to the constant C 2 , with the H signal to provide a signal corresponding to C 2 /H. Summing means 57 sums the signal form multipliers 43 and 44 with the signal from divider 54 to provide an input to subtracting means 60.
A multiplier 63 multiplies the H signal with voltage E Q to provide a signal corresponding to term C 3 H. Summing means 64 sums the signal from multiplier 63 with voltage E R , corresponding to constant C 1 in equation (1), to provide a signal to subtracting means 60. Subtracting means 60 subtracts the signal provided by summing means 57 from the signal provided by summing means 64 to provide a signal W corresponding to the wax content of the oil in line 1 to recording means 62.
Referring to FIG. 2, there is shown another embodiment of the present invention which uses equation 8. Those elements having the same elements as numbers shown in FIG. 1 perform the same functions. Thus, boiling point analyzer 3, gravity analyzer 5 and viscosity analyzer 7 provide signals E 1 , E 2 and E 3 , respectively, corresponding to the 50 percent boiling point, the API gravity, the kinematic viscosity, respectively, of the waxy oil flowing through line 1. Elements 9, 10 and 11 cooperate with analyzer 3, as hereinbefore explained, to provide a signal corresponding to the numerator in equation 7. Elements 15, 16 and 18 cooperate with analyzer 5 and circuit 11 to provide the K signal as hereinbefore explained. In addition to elements 9 through 18, multipliers 20, 21, 22, 23, 25, 31, 33 and 34, summing means 28 and 36 and subtracting means to cooperate as hereinbefore explained to provide the signal MW corresponding to the average molecular weight of the waxy oil in line 1.
Similarly, summing means 48 and 53, logarithmic amplifies 49 and 50, and multiplier 52 cooperate to provide the H signal as hereinbefore explained.
A multiplier 70 multiplies the SG signal with voltage E S to provide a signal corresponding to the term C 19 [SG]. A multiplier 71 multiplies the MW signal with voltage E T to provide a signal corresponding to the term C 21 [NW]. Summing means 72 sums the signals from multipliers 70, 71.
A multiplier 73 multiplies the H signal with voltage E U to provide a signal corresponding to the term C 20 H. Summing means 74 sums the signal from multiplier 73 with voltage E V corresponding to the term C 18 . Subtracting means 75 subtract the signal provided by summing means 72 from the signal provided by summing means 74 to provide signal W, corresponding to the wax content of the waxy oil in line 1, to recorder means 62.
The apparatus of the present invention hereinbefore described measures and records the wax content of waxy oil. The 50% boiling point, the API gravity and the kinematic viscosity of the waxy oil are sensed. The wax content is determined from the sensed parameters. | The 50% boiling point, the gravity and the viscosity of waxy oil are sensed by sensors which provide corresponding signals. A computing circuit connected to the sensors provides a signal corresponding to the wax content of the waxy oil in accordance with the signals from the sensors and equations hereinafter disclosed. | 6 |
FIELD OF THE INVENTION
[0001] This invention pertains to the field of pharmaceutical technology and relates to a pharmaceutical composition comprising topiramate.
BACKGROUND
[0002] Epilepsy is a disease of the nervous system which is caused by brain dysfunction due to excessive discharge of the nerve cells in the brain. It is estimated that the incidence rate of epilepsy is from about 0.3% to 0.5% globally. The morbidity rate is from about 5 to 10 people per 1000 people. Epilepsy is a serious threat to people's health and affects their daily lives.
[0003] Topiramate is a new type of antiepileptic drug and its chemical structure relates to amino-sulfamatemonosaccharide. Topiramate was first developed by Johnson & Johnson Company, Inc. USA. It was marketed under the brand name of Topamax in the UK in 1995. Based on in-vitro studies of neurons in electrophysiological and biochemical experiments, it was found that there were three mechanisms of antiepileptic action. Firstly, topiramate blocks the neuron's depolarization, which indicates that it can block sodium channels. Secondly, topiramate can increase the frequency of activation of γ-aminobutyrate (GABA) receptors by GABA and enhance the ability of influx of chloride ions which indicates that topiramate can enhance the role of inhibitory central neurotransmitters. Thirdly, topiramate can reduce the activity of glutamate AMPA receptors which indicates that topiramate can reduce the effect of excitatory central neurotransmitters.
[0004] The chemical name of topiramate is 2,3:4,5-Di-O-isopropylidene-β-D-fructo-pyranose sulfamate. The molecular formula is C 12 H 21 NO 8 S. Its molecular weight is 339.4. The chemical formula is:
[0000]
[0005] Topiramate is a white crystalline powder with a bitter taste. It is freely soluble in acetone, dimethyl sulfoxide, ethanol, and alkaline solutions containing sodium hydroxide or sodium phosphate. Its solubility in water is approximately 9.8 mg/mL at room temperature.
[0006] Topiramate is sensitive to heat and humidity. When exposed to moisture or heat, it can lead to the degradation of the topiramate in a solid dosage form. Topiramate degradation can be easily detected by the changing in physical appearance (tablet color changing from white to brown or black) and the formation of sulfate ions and organic degradation compounds. This degradation can be also detected by analytical testing methods such as HPLC.
[0007] In order to improve the stability of topiramate and to prevent the degradation of its active ingredient, WO01/89445 discloses topiramate in a blister package without desiccant. The blister pack comprises of a disc-like sheet for placing a pre-dried chamber with the topiramate and a cover sheet for sealing the disc-like sheet. The currently marketed topiramate tablets are mostly packaged in this type of blister pack. But this type of packaging is relatively expensive and the operation process is cumbersome. CN1726011 discloses a double or multiphase topiramate tablet and its preparation method. The tablet has one phase containing topiramate and another phase containing hygroscopic gum material which is selected from alginates, gum arabic or xanthan gum. This preparation is cumbersome, is easy to laminate, and has a low dissolution rate. WO2006/097946 discloses topiramate tablet preparation containing 5%-35% (w/w) of topiramate and 25%-70% (w/w) of spray-dried mannitol granules. The tablet is prepared by by direct compression. The tablet is easy to get capping and has poor content uniformity.
[0008] CN103417501A (201210162377.8) discloses a topiramate pharmaceutical composition containing pregelatinized starch to increase the stability of topiramate which in turn ensures the quality and safety of the composition. Pregelatinized starch also acts as a binder to ensure the hardness and low friability reducing the amount of excipients and cost. This invention also relates to a method of preparing topiramate pharmaceutical composition which includes a dry granulation process. The process is simple; granules have uniform particle size distribution after drying; and it is convenient for storage and transportation and suitable for commercial manufacturing. However, the dry granulation process is not suitable for a large-scale production. Additionally, the use of pregelatinized starch and disintegrating agent in the composition causes a very fast dissolution rate which can not achieve a delayed release effect.
[0009] Thus, to obtain a topiramate formulation with stable chemical properties and/or desired sustained release effect is highly desirable.
SUMMARY OF THE INVENTION
[0010] The purpose of this invention is to provide a solid pharmaceutical composition of topiramate with chemical stability and/or a designable extended release profile. It has been surprisingly found that the pharmaceutical compositions of the present invention have achieved the characteristics of all the above objections. Therefore, the present invention is accomplished by the above discovery.
[0011] Thus, this invention in the first aspect provides solid pharmaceutical compositions containing topiramate, cellulose derivatives, lipids, and optionally other pharmaceutical excipients.
[0012] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the weight ratio of topiramate to cellulose derivative is 100:10˜100.
[0013] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the weight ratio of topiramate to cellulose derivative is 100:15˜75.
[0014] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the weight ratio of topiramate to cellulose derivative is 100:20˜50.
[0015] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the cellulose derivative can be selected from the group consisting of: methyl cellulose, ethyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxypropylmethylcellulose and their combination. In one example, the cellulose derivative is hydroxypropyl methylcellulose.
[0016] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention the weight ratio of topiramate to lipid substance is 100:10˜100.
[0017] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the weight ratio of topiramate to lipid substance is 100:15˜75.
[0018] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the weight ratio of topiramate to lipid substance is 100:20˜50.
[0019] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the lipid substance mentioned above is a type of a strong lipophilic substance, including but not limited to: C16-C22 fatty acids, carnauba wax, C16-C22 fatty acid esters of glycerol, C16-C22 alkyl alcohol, bee wax, synthetic wax, hydrogenated vegetable oil and their combination. In one of the examples, the lipid substance can be selected from the group consisting of: C16-C22 fatty acids, carnauba wax, C16-C22 fatty acid glyceride, C16-C22 alkyl alcohol and any combination thereof. In one of the examples, the lipid substance is C16-C22 fatty acid esters of glycerol. In one of the examples, the lipid substance is glyceryl behenate. In one of the examples, glyceryl behenate can be selected from the group consisting of: behenic acid monoglyceride, diglyceride behenic acid, behenic acid triglyceride and any combination thereof.
[0020] The solid pharmaceutical composition according to any example of the solid pharmaceutical compositions described in the first aspect of the present invention has a topiramate content of from 1 to 99%, from 2 to 75%, or from 5 to 50% based on the total weight of the solid pharmaceutical composition. Because the present invention uses a lipid substance and a cellulose derivatives in combination with topiramate to form a solid pharmaceutical composition, excellent performance of the composition can be achieved. Thus, in addition to the lipid and the cellulose derivatives and topiramate, the amount of other pharmaceutical excipients is not particularly limited. These excipients are usually added in an amount suitable to impart a suitable dosage form of the composition. For example, when preparing tablets or capsules, pharmaceutical excipients may be added appropriately to lower the overall weight of the dosage form. For example, when the granules are prepared, the total weight of the dosage form may be higher, as well as the weight of the pharmaceuticals excipients.
[0021] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the pharmaceutical excipient is one or more selected from the group consisting of a filler, a disintegrant, a binder and a lubricant. In view of the present invention, it was surprisingly discovered that when topiramate is mixed with the lipid and the cellulose derivatives, the mixture enhances the stability of topiramate, i.e. the contribution of present invention to the current technology is the discovery of such mentioned combination. Thus, the combination may or may not include other pharmaceutical excipients.
[0022] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the fillers (generally also referred to as a diluents) include, but not limited to, starch or its derivatives such as corn starch, pregelatinized starch, modified starch, etc., cellulose or derivatives thereof such as microcrystalline cellulose, ethyl cellulose, methylcellulose etc; saccharides such as glucose, sucrose, lactose, mannitol, sorbitol; neutral minerals such as calcium carbonate, calcium hydrogen phosphate, and combinations thereof. As used herein, the term diluent or filler is defined as an inert material used for making up the weight and/or size of the pharmaceutical composition in the form of a substance in the composition or a mixture of compounds. Preferably, a diluent or filler is added when the amount of the active ingredient and other excipients are not enough to create a desired tablet size. The amount of the diluent or filler for the pharmaceutical composition according to the present invention may be determined according to conventional methods by a person skilled in the art, particularly after the amount of other excipients such as disintegrating agents, binders, lubricants etc. then the amount of diluents and/or fillers can be determined based on the size requirement.
[0023] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the disintegrant comprises, but is not limited to, cross-linked polyethylene polypyrrolidone, sodium starch glycolate, croscarmellose sodium, Hydroxypropylcellulose etc, and combinations thereof. Further, the pharmaceutical composition comprises 0 to 10% disintegrant, 0 to 8% disintegrant, or 0 to 5% disintegrant relative to the total percentage weight of the pharmaceutical composition, The use, not use, or use less quantity of disintegrants are also known to the person skilled in the art, such as erosion-type matrix sustained-release tablets. The solid pharmaceutical compositions of the present invention may in some cases have no disintegrants. For example, when the dosage form is capsule, the disintegrants may not be added to the solid pharmaceutical compositions of the present invention.
[0024] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the binder comprises, but is not limited to, polyethylene glycol, starch, polyvinylpyrrolidone, hydroxypropylmethylcellulose etc., and combinations thereof. Water can be used as a wetting agent in the present invention, and can also be used as a potential binder in wet granulation process because many excipients in solid pharmaceutical formulations have a certain degree of adhesiveness and water can be removed from the final product. In addition, many excipients in solid pharmaceutical formulations have adhesiveness and allow direct compression or encapsulation. Therefore, a binder may or may not be added to the pharmaceutical composition of the present invention. Even with the wet granulation technology, a binder may not be added. If a binder is added, the amount of the binder used is from 0.1 to 10%, 0.2 to 5%, or 0.5 to 2.5% relative to the total percentage weight of the pharmaceutical composition, or it may also be used based on the experience of a person skilled in the art.
[0025] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the lubricant (including a glidant) functions as the powder material which can assist powders to form a dosage form. For example, when a capsule is prepared, the powder material can be filled uniformly into the capsule shell. For example, when the tablet is compressed, the powder material can be filled uniformly into the tooling mold of the tablet press and compressed without stickingness. Examples of lubricants include, but are not limited to, magnesium stearate, calcium stearate, talc, starch, stearic acid, colloidal silica, polyethylene glycol, etc. If added, the amount of lubricant used is from 0.1 to 10%, 0.2 to 5%, or 0.2 to 2% relative to the total percentage weight of the pharmaceutical composition, or it may also be used based on the experience of a person skilled in the art.
[0026] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the pharmaceutical dosage form is selected from the group consisting of tablets, capsules, mini-tablet in capsules, etc. The term of mini-tablet in capsules refers to a form of formulation in which the small size tablets (e.g., 30 to 100 mg per tablet, for example, tablets each weighing 30 to 50 mg) are encapsulated into a hard shell capsule.
[0027] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the pharmaceutical dosage form is uncoated tablet or coated tablet with a coating material.
[0028] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the pharmaceutical dosage form is a coated tablet. Further, the coated tablet comprises a coating material of 1% to 6%, or 2% to 5% by percentage weight gain based on the total weight of the tablet. In one embodiment, the coating material is selected from the group consisting of ethyl cellulose, hydroxypropylmethylcellulose and methacrylic acid-alkyl acrylate copolymers. In one embodiment, the coating material is an aqueous dispersion of hydroxypropylmethylcellulose. In the other embodiment, the coating material is Opadry®, which is an aqueous dispersion of hydroxypropylmethylcellulose. Further, the coating material is selected from the group consisting of Opadry® 85F20694, Opadry® 85F32004, Opadry® 85F23452 and Opadry®85F18422.
[0029] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention comprises:
[0030] Topiramate: 100 parts by weight,
[0031] cellulose derivatives: 10 to 100 parts by weight,
[0032] lipid substances: 10 to 100 parts by weight,
[0033] pharmaceutical excipients: 0 to 500 parts by weight.
[0034] The solid pharmaceutical composition according to any example of the solid pharmaceutical compositions described in the first aspect of the present invention comprises:
[0035] Topiramate: 100 parts by weight,
[0036] cellulose derivative: 15 to 75 parts by weight,
[0037] lipid substances: 15 to 75 parts by weight,
[0038] pharmaceutical excipients: 0 to 250 parts by weight.
[0039] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention comprises:
[0040] Topiramate: 100 parts by weight,
[0041] cellulose derivatives: 20 to 50 parts by weight,
[0042] lipid substances: 20 to 50 parts by weight,
[0043] pharmaceutical excipients: 0 to 200 parts by weight.
[0044] According to any example of the solid pharmaceutical compositions described in the first aspect of the present invention, the pharmaceutical composition is placed at a 40° C. condition for 5 months, wherein the impurity of 2,3:4,5-di-O-(1-methylethylidene)-β-D-fructose fructose by weight (%) before and after high temperature treatment, is less than 100%, especially less than 80%, especially less than 70%: for example, from 40 to 100%, from 40 to 80%, or from 40 to 70%.
[0045] Furthermore, the second aspect of the present invention provides a method for preparing a solid pharmaceutical composition, (such as any example of the solid pharmaceutical compositions described in the first aspect of the present invention), comprising the steps of as follows:
[0046] (1) Each of the materials were pulverized to pass through a 60 mesh sieve, the amount of topiramate and cellulose derivatives, and lipid substances are mixed thoroughly to obtain a powder mixture;
[0047] (2) The solid pharmaceutical preparation is prepared by mixing the powder mixture in step (1) with an optional pharmaceutical excipient and making into suitable solid dosage form according to conventional solid pharmaceutical preparation.
[0048] According to any example of the methods described in the second aspect of the present invention, the solid pharmaceutical preparation prepared in step (2) is selected from the group consisting of tablets, capsules and minitabletin capsules.
[0049] According to any example of the methods described in the second aspect of the present invention wherein in the step (2), when the solid pharmaceutical preparation is prepared, the granules can be prepared by a wet granulation process or a dry granulation process, then compressed into tablets, or encapsulated into capsules, or encapsulated as the minitablets into capsules.
[0050] According to any example of the methods described in the second aspect of the present invention wherein in the step (2), when the solid pharmaceutical preparation is prepared, granulation step may not be necessary. The powder mixture can be compressed directly to tablets, encapsulated, or encapsulated as microtablets in capsules without the granulation steps.
[0051] According to any example of the methods described in the second aspect of the present invention, the pharmaceutical composition comprises of topiramate, cellulose derivative, lipid, and pharmaceutical excipients of choice.
[0052] According to any example of the methods described in the second aspect of the present invention, the weight ratio of topiramate to the cellulose derivative in the pharmaceutical composition is from 100:10 to 100.
[0053] According to any example of the methods described in the second aspect of the present invention, the weight ratio of topiramate to the cellulose derivative in the pharmaceutical composition is 100:15 to 75.
[0054] According to any example of the methods described in the second aspect of the present invention, the weight ratio of topiramate to the cellulose derivative in the pharmaceutical composition is 100:20 to 50.
[0055] According to any example of the methods described in the second aspect of the present invention, the cellulose derivative described in the pharmaceutical composition is selected from the group consisting of methylcellulose, ethyl cellulose, sodium carboxymethylcellulose, propylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose and combinations thereof. In one embodiment, the cellulose derivative is hydroxypropylmethylcellulose.
[0056] According to any example of the methods described in the second aspect of the present invention, the weight ratio of topiramate to the lipid substance in the pharmaceutical composition is 100:10 to 100.
[0057] According to any example of the methods described in the second aspect of the present invention, the weight ratio of topiramate to the lipid substance in the pharmaceutical composition is 100:15 to 75.
[0058] According to any example of the methods described in the second aspect of the present invention, the weight ratio of topiramate to the lipid substance in the pharmaceutical composition is 100:20 to 50.
[0059] According to any example of the methods described in the second aspect of the present invention, the lipid substance in the pharmaceutical composition is a lipophilic substance which include, but is not limited to, C16-C22 fatty acid, Brazil Palm wax, C16-C22 fatty acid glycerides, C16-C22 alkyl alcohols, beeswax, synthetic waxes, hydrogenated vegetable oils and mixtures thereof. In one embodiment, the lipid is selected from the group consisting of: C16-C22 fatty acids, carnauba waxes, C16-C22 fatty acid glycerides, C16-C22 alkyl alcohols and mixtures thereof. In one embodiment, the lipid is a C16-C22 fatty acid glyceride. In one embodiment, the lipid is glyceryl behenate. In one embodiment, the behenate is selected from the group consisting of monoglycerides, behenic acid diglycerides, behenic acid triglycerides, and mixtures thereof.
[0060] According to any example of the methods described in the second aspect of the present invention, the topiramate comprises from 1 to 99%, such as from 2 to 75%, such as from 5 to 50% of the total weight of the pharmaceutical composition. The present invention uses a lipid substance and a cellulose derivative in combination with topiramate to form a solid pharmaceutical composition with excellent property. Thus, in addition to the combination of the lipid and the cellulose derivative and the topiramate, the amount of the other pharmaceutical excipients are not particularly limited, usually, to make the desirable weight of certain dosage form. For example, when formulating tablets or capsules, because the amount of the lipid substance and cellulose derivative combination is fixed, the other pharmaceutical excipients can be adjusted due to the final total weight of the dosage form. For example, when prepare for granules, because the weight of the dosage form is increased, the amount of other pharmaceutical excipients will be increased.
[0061] According to any example of the methods described in the second aspect of the present invention, one or more excipients used in the described drug combination are selected from the following groups: filler, disintegrant, binder, lubricant. The surprising discovery of current invention is that the combination of topiramate, lipid, and the cellulose derivatives can provide an excellent chemical stability for topiramate. Because the particular contribution of the present invention to the prior art is the discovery of such a special combination, the described pharmaceutical excipients may or may not be included in the composition of the present invention.
[0062] According to any example of the methods described in the second aspect of the present invention, the filler (usually also referred to as diluent) in the solid pharmaceutical composition include but not limited to: starch or its derivatives such as corn starch, pregelatinized starch, modified starch, etc.; cellulose or its derivatives such as microcrystalline cellulose, ethyl cellulose, methyl cellulose, etc.; carbohydrates such as glucose, sucrose, lactose, mannitol, sorbitol; A neutralized minerals such as calcium carbonate, calcium hydrogen phosphate,etc and its combinations. As used herein, the term “diluent” or “filler” is defined as an inert material to increase the weight and/or size of the pharmaceutical compositions, which exists in the form of a substance or a mixture of compounds in the composition. Preferably, a diluent or filler is added when the amount of the active ingredient and other excipients is too small to obtain a tablet of a suitable size. The percentage weight of the diluent or filler necessary for the pharmaceutical composition, according to the present invention, may be determined by conventional methods well known to a person skilled in the art, especially a moderate amount of the diluent or filler will be added due to the requirement of the product size after the amount of other excipients such as disintegrating agents, binders, lubricants are confirmed.
[0063] According to any example of the methods described in the second aspect of the present invention, the disintegrant used in the described solid pharmaceutical composition includes but not limited to: cross-linked polyethylene polypyrrolidone, sodium starch glycolate, croscarmellose sodium, low-substituted hydroxypropylcellulose and their combinations. Furthermore, the pharmaceutical composition comprises 0 to 10%, from 0 to 8% or 0 to 5% of disintegrant relative to the total weight of the composition/The amount of the disintegrant also can be based on the experience of a technical personnel in the field to use no or less amount of disintegrant in drug product, such as dissolved-matrix type sustained-release tablets made for sustained-release purposes. The solid pharmaceutical compositions in the present invention may have no disintegrating properties in some cases. For example in some cases, for capsules formulation, the disintegrants may not be added to the solid pharmaceutical compositions of the present invention.
[0064] According to any example of the methods described in the second aspect of the present invention, the binder in the described solid pharmaceutical composition includes. but not limited to: polyethylene glycol, starch, polyvinylpyrrolidone, hydroxypropylmethylcellulose, etc and their combinations. Water as a wetting agent in the present invention can also be used as a potential binder because many excipients in solid pharmaceutical formulations have a certain degree of adhesiveness and can be used during wet granulation, although the water will be removed from the final product in the present invention. In addition, the excipients in the pharmaceutical solid formulations have adhesiveness and allow the materials to be directly compressed or filled into capsules. It can be seen that Therefore, the binder may or may not be added to the solid pharmaceutical composition of the present invention. During the wet granulation, the binder can be added or not be added. If added, based on the total weight of the pharmaceutical composition, the amount of the binder is from 0.1 to 10%, 0.2 to 5%, or 0.5 to 2.5%, and or it may also be used according to the experience of a person skilled in the art.
[0065] According to any example of the methods described in the second aspect of the present invention, the lubricant (including glidant) mentioned is used to make the powder material formed, for example, the powder material can be uniformly filled into the capsule shell during encapsulation process. For example, the powder material can be uniformly filled into the mold of the tabletting machine to avoid the sticking to the tablet tooling during compression. Examples of lubricants include but are not limited to: magnesium stearate, calcium stearate, talc, starch, stearic acid, colloidal silica, polyethylene glycol etc. If lubricant is added, the amount of lubricant used can be from 0.1 to 10%, 0.2 to 5%, or 0.2 to 2% relative to the total weight of the pharmaceutical composition, which may also be used according to the experience of a person skilled in the art.
[0066] According to any example of the methods described in the second aspect of the present invention, the described solid pharmaceutical composition is an uncoated or coated tablet with a coating material.
[0067] According to any example of the methods described in the second aspect of the present invention, the described solid pharmaceutical composition is a coated tablet. Furthermore, the coated tablets comprise a coating material of 1% to 6%, 2% to 5% based on the total weight of the tablet. In one embodiment, the coating material is selected from the group of ethyl cellulose, hydroxypropylmethylcellulose and methacrylic acid-alkyl acrylate copolymers. In one embodiment, the coating material is an aqueous dispersion of hydroxypropylmethylcellulose. In one embodiment, the coating material is Opadry® which is an aqueous dispersion of hydroxypropylmethylcellulose; Furthermore, the coating material may selected from one of the Opadry® 85F20694, Opadry® 85F32004, Opadry® 85F23452 and Opadry®85F18422.
[0068] According to any example of the methods described in the second aspect of the present invention, the described solid pharmaceutical composition includes:
[0069] Topiramate: 100 parts by weight,
[0070] cellulose derivatives: 10 to 100 parts by weight,
[0071] lipid substances: 10 to 100 parts by weight
[0072] pharmaceutical excipients: 0 to 500 parts by weight.
[0073] According to any example of the methods described in the second aspect of the present invention, the described solid pharmaceutical composition includes:
[0074] Topiramate: 100 parts by weight,
[0075] cellulose derivatives: 15 to 75 parts by weight,
[0076] lipid substances: 15 to 75 parts by weight,
[0077] The pharmaceutical excipients: 0 to 250 parts by weight.
[0078] According to any example of the methods described in the second aspect of the present invention, the described solid pharmaceutical composition includes:
[0079] Topiramate: 100 parts by weight,
[0080] cellulose derivatives: 20 to 50 parts by weight,
[0081] lipid substance: 30 to 50 parts by weight,
[0082] pharmaceutical excipients: 0 to 200 parts by weight.
[0083] According to any example of the methods described in the second aspect of the present invention, the described solid pharmaceutical composition placed at 40° C. temperature for 5 months, wherein the impurities of 2,3:4,5-di-O-(%) is less than 100%, especially less than 80%, especially less than 70%: for example, from 40 to 100%, from 40% to 80%, or from 40 to 70%.
[0084] It is known that the impurity of topiramate and its formulation composition is 2,3,4,5-di-O-(1-methylethylidene)-β-D-fructopyranose (which may be referred to as impurity A in the present invention, English chemical name is: 2,3:4,5-Bis-O-(1-methylethylidene)-β-d-fructopyranose, molecular formula:C 12 H 20 O 6 , molecular weight:260.28) which requires special attention, especially the changes during the long-term storage process. It is surprisingly found that the use of the cellulose derivatives, lipids and stearic acid or a salt thereof in combination with topiramate that can impart an excellent chemical stability. Especially, the impurity A does not increase with the extending of storage time.
[0085] Thus, the third aspect of the present invention provides a method for inhibiting the growth of topiramate impurity of 2,3:4,5-di-O-(1-methylethylidene)-β-D-fructopyranose in solid pharmaceutical compositions of. The method comprises a preparation of the solid pharmaceutical composition including topiramate, cellulose derivative, lipid substance, and altogether.
[0086] According to any example of the methods described in the third aspect of the present invention, the described solid pharmaceutical composition comprises topiramate, cellulose derivative, lipid, and optional other pharmaceutical excipients.
[0087] According to any example of the methods described in the third aspect of the present invention, the weight ratio of topiramate to the cellulose derivative in the solid pharmaceutical composition is from 100:10 to 100.
[0088] According to any example of the methods described in the third aspect of the present invention, the weight ratio of topiramate to the cellulose derivative in the solid pharmaceutical composition is from 100:15 to 75.
[0089] According to any example of the methods described in the third aspect of the present invention, the weight ratio of topiramate to the cellulose derivative in the solid pharmaceutical composition is 100:20 to 50.
[0090] According to any example of the methods described in the third aspect of the present invention, cellulose derivative in the solid pharmaceutical composition is selected from one of the following materials: methylcellulose, ethyl cellulose, sodium carboxymethylcellulose, hydroxypropyl Cellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose and its combinations thereof. In one embodiment, the cellulose derivative is hydroxypropylmethylcellulose.
[0091] According to any example of the methods described in the third aspect of the present invention, the weight ratio of topiramate to the lipids in the solid pharmaceutical composition is 100:10 to 100.
[0092] According to any example of the methods described in the third aspect of the present invention, the weight ratio of topiramate to the lipids in the solid pharmaceutical composition is 100:15 to 75.
[0093] According to any example of the methods described in the third aspect of the present invention, the weight ratio of topiramate to the lipids in the solid pharmaceutical composition is 100:20 to 50.
[0094] According to any example of the methods described in the third aspect of the present invention, the lipids described in the solid pharmaceutical composition refers to a lipophilic substance which includes but is not limited to: C16-C22 fatty acid, carnauba wax, C16-C22 fatty acid glycerides, C16-C22 alkyl alcohols, beeswax, synthetic waxes, hydrogenated vegetable oils and mixtures thereof. In one embodiment, the lipid is selected from:C16-C22 fatty acids, carnauba waxes, C16-C22 fatty acid glycerides, C16-C22 alkyl alcohols and mixtures thereof. In one embodiment, the lipid is a C16-C22 fatty acid glyceride. In one embodiment, the lipid is glyceryl behenate. In one embodiment, the behenate is selected from: monoglycerides, behenic acid diglycerides, behenic acid triglycerides, and mixtures thereof.
[0095] According to any example of the methods described in the third aspect of the present invention, the percent weight of topiramate in the described solid pharmaceutical composition is 1 to 99% based on the total weight of the solid pharmaceutical composition, for example 2-75% or 5-50%. In the present invention a lipid substance and a cellulose derivative are used in combination with topiramate to form a solid pharmaceutical composition, and the combination provides an excellent quality. Thus, in addition to the lipid, the cellulose derivatives, and the topiramate, the amount of the other pharmaceutical excipients are not particularly limited and are usually added in a suitable amount to impart a suitable dosage form of the composition. For example, when preparing tablets or capsules, the amount of these pharmaceutical excipients may be adjusted due to the overall weight of the dosage form. For example, when the granules are prepared, the amount of these pharmaceutical excipients may be increased due to overall increased weight of the dosage form.
[0096] According to any example of the methods described in the third aspect of the present invention, one or more pharmaceutical excipients in the solid pharmaceutical composition is selected from:filler, disintegrant, binder, lubricant.
[0097] According to any example of the methods described in the third aspect of the present invention, the filler (usually also referred to as diluent) in the solid pharmaceutical composition includes but isn't limited to: starch or its derivatives such as corn starch, pregelatinized starch, modified starch,etc.; cellulose or its derivatives such as microcrystalline cellulose, ethyl cellulose, methyl cellulose,etc.; Saccharides such as glucose, sucrose, lactose, mannitol, sorbitol; Neutralized minerals such as calcium carbonate, calcium hydrogen phosphate, and the like, and combinations thereof.
[0098] According to any example of the methods described in the third aspect of the present invention, the disintegrant in the described solid pharmaceutical composition includes but not limited to: cross-linked polyethylene polypyrrolidone, sodium starch glycolate, croscarmellose Sodium, low-substituted hydroxypropylcellulose and their combinations. Furthermore, relative to the total weight of the pharmaceutical composition, the pharmaceutical composition comprises 0 to 10%, 0 to 8%, or 0 to 5% of disintegrant, and its amount also can be decided based on the experience of a technical personnel in the field. It's common to use no or use less disintegrant in drug product, such as dissolved-matrix type of sustained-release tablets made for sustained-release purposes. Because the solid pharmaceutical compositions of the present invention may have no disintegrating properties in some cases, for example, encapsulation, the disintegrants may not be added to the pharmaceutical compositions.
[0099] According to any example of the methods described in the third aspect of the present invention, the binder in the described solid pharmaceutical composition includes but isn't limited to: polyethylene glycol, starch, polyvinylpyrrolidone, hydroxypropylmethylcellulose, etc, and their combinations. Because the material of many solid pharmaceutical formulations has a certain degree of adhesiveness during the wet granulation process, water can be used as a wetting agent. Water as a wetting agent in the present invention can also be used as a potential binder, although the water added are removed from the final product in the present invention. In addition, the materials used in the solid pharmaceutical formulations have adhesiveness and allow the powder to be directly compressed or filled into capsules. Therefore, the binder may or may not be added to the solid pharmaceutical formulation of the present invention. Even with the wet granulation process, the binder can still not be added. If added, based on the total weight of the pharmaceutical composition, the amount of the binder is 0.1 to 10%, 0.2 to 5%, or 0.5 to 2.5%, and may also be based on the experience of a technical person in the field.
[0100] According to any example of the methods described in the third aspect of the present invention, the lubricant (including glidant) in the described solid pharmaceutical composition is used to promote the powder material can be smoothly passing through hopper. For example, the powder material can be uniformly filled into the capsule shell during encapsulation. For example, the powder material can be uniformly filled into the mold of the tabletting machine and the sticking can be prevented during compression process. Examples of lubricants used include, but are not limited to: magnesium stearate, calcium stearate, talc, starch, stearic acid, colloidal silica, polyethylene glycol, etc. If added, the amount of lubricant used relative to the total weight of the pharmaceutical composition is 0.1 to 10%, 0.2 to 5%, or 0.2 to 2%. The amount of lubricant used can also be based on the experience of a technical person in the field.
[0101] According to any example of the methods described in the third aspect of the present invention, the solid pharmaceutical composition is a pharmaceutical dosage form selected from the following:tablets, capsules, mini-tablet incapsules, etc.
[0102] According to any example of the methods described in the third aspect of the present invention, the described solid pharmaceutical composition is an uncoated or coated tablet with a coating material.
[0103] According to any example of the methods described in the third aspect of the present invention, the described solid pharmaceutical composition is a coated tablet. Furthermore, the coated tablets comprise a coating material of 1% to 6%, 2% to 5% based on the total weight of the tablets. In one embodiment, the coating material is selected from:ethyl cellulose, hydroxypropylmethylcellulose, and methacrylic acid-alkyl acrylate copolymers. In one embodiment, the coating material is an aqueous dispersion of hydroxypropylmethylcellulose. In one embodiment, the coating material is Opadry® which is an aqueous dispersion of hydroxypropylmethylcellulose; Furthermore, the coating material is selected from:Opadry® 85F20694, Opadry® 85F32004, Opadry® 85F23452 and Opadry®85F18422.
[0104] According to any example of the methods described in the second aspect of the present invention, the described solid pharmaceutical composition includes:
[0105] Topiramate: 100 parts by weight,
[0106] cellulose derivative: 10 to 100 parts by weight,
[0107] lipid substance :10 to 100 parts by weight,
[0108] pharmaceutical excipients: 0 to 500 parts by weight.
[0109] According to any example of the methods described in the third aspect of the present invention, the solid pharmaceutical composition comprises:
[0110] Topiramate: 100 parts by weight,
[0111] cellulose derivative: 15 to 75 parts by weight,
[0112] lipid substance: 15 to 75 parts by weight,
[0113] pharmaceutical excipients: 0 to 250 parts by weight.
[0114] According to any example of the methods described in the third aspect of the present invention, the solid pharmaceutical composition comprises:
[0115] Topiramate: 100 parts by weight,
[0116] cellulose derivative: 20 to 50 parts by weight,
[0117] lipid substance: 30 to 50 parts by weight,
[0118] pharmaceutical excipients: 0 to 200 parts by weight,
[0119] According to any example of the methods described in the third aspect of the present invention, the described solid pharmaceutical compositions placed at 40° C. temperature for 5 months, wherein the impurity of 2,3:4,5-di-O-(1-methylethylidene)-β-D-pyran fructose is less than 100%, especially is less than 80%, especially is less than 70%, for example, 40 to 100%, 40% to 80%, or 40 to 70%.
[0120] Furthermore, the fourth aspect of the present invention provides a solid pharmaceutical agent comprising the first pharmaceutical part and the second pharmaceutical part which are independent of each other in physical space.
[0121] According to any example of the solid pharmaceutical agents described in the fourth aspect of the present invention, the first pharmaceutical part is a solid pharmaceutical composition described in any one of the first aspect of the present invention.
[0122] According to any example of the solid pharmaceutical agents described in the fourth aspect of the present invention, the second pharmaceutical part uses 900 ml of water as the dissolution medium. When the drug dissolution test is carried out at 50 rpm with paddle, the drug released at 45 minutes is more than that 70% of the amount of the drug contained in the second pharmaceutical part.
[0123] According to any example of the solid pharmaceutical agents described in the fourth aspect of the present invention, the second pharmaceutical part comprises 10 to 90% of topiramate and 10 to 90% of the pharmaceutical excipients. According to the dissolution performance of the above-mentioned the second part, it is apparent that the pharmaceutical excipients used therein are conventional pharmaceutical excipients other than sustained release pharmaceutical excipients, such as the pharmaceutical excipients described in the solid pharmaceutical compositions according to any examples of the pharmaceutical compositions in the present invention.
[0124] According to any example of the solid pharmaceutical agents described in the fourth aspect of the present invention, the weight ratio of topiramate is 1 to 5:1 between the first pharmaceutical part and the second pharmaceutical part.
[0125] According to any example of the solid pharmaceutical agents described in the fourth aspect of the present invention, the solid pharmaceuticals agents described in the first pharmaceutical part and the second pharmaceutical part independently exist in the form of bilayer tablets, minitablets in capsules, or pellet in capsules. The term “pellet capsule” is well known in the field as capsules formed by encapsulating the multiple pellets of the same or different types into capsules.
[0126] In the invention, any of the technical features of any of the aspects of the present invention or any of the embodiments may also apply to any of the other embodiments or any of the other aspects as long as they are not contradictory. When it's applicable for each other, if necessary, the corresponding features can be properly modified. The various aspects and features of the present invention will be further described below.
[0127] All references cited herein are hereby incorporated by reference. If the contents expressed in these documents are inconsistent with the present invention, the contents of the present invention is valid. In addition, the various terms and phrases used in the present invention have the general meaning that well known to a person skilled in the art. Even so, the present invention still wishes to provide a more detailed description and explanation of these terms and phrases, the terms and phrases mentioned. In the case of any inconsistency with the known meaning, the meaning expressed in the present invention shall prevail.
[0128] The various aspects of the invention are further described below.
[0129] In the present invention, % is a percentage of weight/weight unless otherwise stated.
[0130] The topiramate solid pharmaceutical compositions of the present invention can be used for newly diagnosed epilepsy patients as a monotherapy or epilepsy patients switching from a combination therapy to a monotherapy It can also be used as an additional treatment for adult and 2-16 year old children with partial seizures.
[0131] The topiramate solid pharmaceutical composition of the present invention is generally used in an amount such that both adults and children are recommended to start treatment from a low dose and then gradually increase the dosage to an effective dose. This product is effective in the treatment of partial seizures in adults and children. In the control plus therapy test, it was confirmed that the concentration of topiramate plasma was not associated with clinical efficacy. There is no evidence that topiramate is intolerant in humans, and dose finding experiments in adults with partial seizures have shown that doses higher than 400 mg/day (600, 800, and 1000 mg/day) do not increase efficacy. Application of this product in the treatment do not have to monitor the topiramate plasma concentration to achieve the best results. During the treatment with this product in combination with phenytoin, only a very small number of cases need to adjust the amount of phenytoin to achieve the best clinical efficacy. The amount of this product may need to be adjusted during the addition or discontinuation phenytoin and carbamazepinein the treatment. It is suitable to take this product with or without food.
[0132] During the add-on therapy, for adults (17 years old and above), the recommended dose is to 400 mg/day, divided into 2 doses. Daily dose of 200 mg/day produces lower consistency and efficacy than 400 mg/day. Recommended initial treatment is from 50 mg/day, gradually adjusted to an effective dose. For 2-16 year old children as a concomitant treatment, the recommended total daily dose is 5-9 mg/kg/day, divided into 2 doses. Dosage adjustments should be taken from 25 mg (or less, depending on the dose range of 1-3 mg/kg/day) for the first week aken at night. The the dose is adjusted at every 1 or 2 weeks by increasing 1-3 mg/kg/day (divided into 2 doses) until the best clinical results are reached. The dose adjustment should be based on the clinical results achieved.
[0133] For monotherapy, when the other concurrent antiepileptic drug is stopped and the treatment is converted to topiramate therapy alone, withdrawal effect on epilepsy control should be considered. Unless there is safety considerations for the rapid withdrawal of the other antiepileptic drugs, under the normal circumstances, the concurrent medicine should be withdraw slowly. It is recommended to reduce by about ⅓ of the dose every 2 weeks. During the withdrawal of enzyme induction type of medication, topiramate plasma concentration will increase. When the clinical symptom occurs, the topiramate dose should be decreased. Adult (17 years old and above) dose adjustment should start from 25 mg per night for 1 week. Subsequently, the dose is increased to 25-50 mg every week or every 2 weeks twice daily. If the patient is intolerant, adjust the dosage regimen, reduce the dose increment, or prolong the dose adjustment interval. Dosage should be adjusted based on the clinical efficacy. For adult topiramate monotherapy, the recommended daily total dose is 100 mg, and the maximum is 500 mg. Some patients with refractory epilepsy can tolerate up to a daily dose of 1000 mg. The above recommended dose is applicable to all adults, including the elderly and patients without kidney disorders. For children between ages 2 to 16, the dose adjustment should be performed from 0.5-1 mg/kg to start with for 1 week. Then increase by 0.5-1 mg/kg/day (2 doses) for every 1-2 weeks. If the child is intolerant, adjust the dosage regimen, reduce the dose increment, or prolong the dose adjustment interval. The dosage should be adjusted according to the clinical efficacy. For the topiramate monotherapy or single drug treatment, the recommended daily dose is from 3 to 6 mg/kg/day. For children newly diagnosed with partial seizures, the daily dose can be up to 500 mg/day.
DETAILED DESCRIPTION OF THE INVENTION
[0134] The following examples are provided for the purpose of illustration and are not intended to be used in any way and should not be considered as limitations for this invention. A person skilled in the art will recognize the conventional variations and modifications may be made to the following examples without departing from the spirit or scope of the invention.
[0135] In the following examples of the preparation of the composition unless otherwise stated, the tablets or capsules are prepared in a batch size of 10 kg. Each tablet or capsule contains 100 mg of the active ingredient listed as 100 mg of topiramate in the formulation.
[0136] In the following examples of the preparation of the composition, the various materials are milled by passing through the 80 mesh sieve, unless otherwise stated. In the present invention, various glyceryl behenate and other materials used are readily available in the market. In the following tests of the present invention, when glycerol behenate is used, glycerol dibehenate esters conformed to the British Pharmacopoeia or the European Pharmacopoeia of the version 7.0, unless otherwise specified. As described in the standard, it is a mixture of glyceryl monobeheneate, glyceryl dibehenate, glyceryl tribehenate. Unless otherwise stated, the materials used in the examples, especially the API, are all from the same batch.
Test Method Example Section
Test Method Example 1: HPLC Method for Determining the Amount of Active Ingredient
[0137] This test method can be used to test the amount of the active ingredient in the in-process samples, and the final product; the details of the examples are as followed:
[0138] It is determined according to the Chinese Pharmacopoeia of the 2010 edition, section 2, Appendix IA, the high performance liquid chromatography test method;
[0139] The chromatographic conditions and system suitability test:use octyl-bonded silica as a filler; the mobile phase consist of 0.01 mol/L of ammonium acetate solution (adjusted pH to 4.25±0.2 with acetic acid) and acetonitrile (3:1) as mobile phase; the detector is a refractive index detector, the detection temperature and column temperature are 35° C.; theoretical plate numbers for topiramate peak should not be less than 3000;
[0140] The test method:accurately weigh the amount of the test sample (equal to topiramate about 60 mg), transfer to a 200 ml volumetric flask, add acetonitrile-water (1:4) of 100.0 ml accurately, sealed and shake for 1 hour, centrifuged, filter the upper clear liquid with 0.2 μm filter, take the filtrate as the test solution; accurately weigh 60 mg of topiramate reference standard, transfer it to a 200 ml volumetric flask, add acetonitrile-water (1:4) 100.0 ml accurately, sealed and shake to dissolve, as the standard solution; inject 50 μl each from sample and standard solution, respectively, into the liquid chromatograph, record the chromatogram, use external standard method to calculate assay value of C12H21NO8S in sample.
Test Method Example 2: HPLC Method for Determining the Amount of Impurity A in Test Sample
[0141] The method can be used to test the amount of the impurity A in active pharmaceutical ingredient, the in-process samples, and the final product, details are as follows:
[0142] Test method:accurately weigh the amount of the test sample (equal to topiramate about 120 mg), transfer to a 25 ml-volumetric flask, add acetonitrile-water (1:4) mixture 10.0 ml accurately, sealed and shake for 1 hour, then centrifuged, filter the upper clear liquid with a 0.2 μm filter, take the filtrated solution as the test solution;
[0143] Transfer both 1 ml test solution and about 8 mg accurately weighed impurity A reference standard, onto a 200 mL-volumetric flask, add mobile phase to the mark, shake well, then used as the standard solution;
[0144] According to the chromatographic conditions in test method example 1, inject accurately measured of 50 μl of sample and standard solution, respectively, into the liquid chromatograph, adjust the sensitivity of the instrument to ensure that the peak area of the topiramate in the control solution could meet the requirement of correct integration. The chromatogram of the test solution should be recorded for double value of the main peak retention time/The external standard method should be used to calculate the value of impurities A with the peak area. Generally speaking, the value of impurity A in topiramate formulation should be less than 0.7%, as required by a person skilled in the art.
Test Method Example 3: Stability Study
[0145] Various test samples were placed in a sealed aluminum-plastic composite film bag to prevent the inside and outside air exchange. The test samples were then placed in a controlled 40° C. stability chamber for 5 months to perform a routine high temperature accelerated stability test.
[0146] The assay of the topiramate active ingredient in the samples are determined by using method in test method example 1, including samples in 0-month (not processed at 40° C.) and 5-month (processed at 40° C.) (Unit is mg/g which means the amount of topiramate (mg) in 1 g test sample), and using the following formula to calculate the residual value of topiramate (%) after high temperature treatment in each test sample:
[0000] The residual assay (%) of topiramate=[assay in 5-month/assay in 0-month]×100%
[0147] The closer to 100% of the above residual assay (%), the more stable the sample is. When the active ingredient is stored for a long time and the content is reduced due to various reasons, the residual assay should be more than 90% after 5 months stored at 40 □ generally. If it is less than 90%, the product is usually considered as unqualified.
[0148] The assay of the impurity A in the samples are determined by using method in test method example 2, including samples in 0 month (not processed at 40° C.) and 5 month (processed at 40° C.). The increase in the amount or increment (%) of impurity A in each test sample are calculated based on the following formula:
[0000] The increase in the amount (%) of impurity A =[(assay for impurity A in 5 months−assay for impurity A in 0 month)/assay of impurity A in 0 month)]×100%
[0149] The closer to 0% value of the above increase amount (%) is, the more stable the sample is; and when the increment is greater, it shows more impurity A in sample.
Example 1
Preparation of a Solid Pharmaceutical Combination Comprising Topiramate
[0150] According to Sample Number Ex1-01 to Ex1-11 in the following table 1, eleven blends can be prepared with different content of topiramate, glyceryl behenate and hydroxypropylmethylcellulose (HPMC). The preparation of the mixed sample is as follows: (1) Each ingredients was milled to fine powder which can pass 60 mesh sieve. The topiramate, glyceryl behenate and hydroxypropylmethylcellulose were mixed fully, and then divided equally into 2 portions. One portion of these mixture is encapsulated into capsule and the other portion compressed into tablets.
[0151] The stability of the tablets from the eleven samples was examined by the method described in Test Method Example 3. The remaining topiramate (%) after 5 months and the increment (%) of the impurity Aare calculated, the result is as follows shown on Table 1:
[0000]
TABLE 1
glyc-
Hydroxy-
the
eryl
propyl
the residual
increment
Sample
be-
methyl-
assay of the
of the
No.
Topiramate
henate
cellulose
topiramate
impurity A
Ex1-01
100
35
0
87.2%
258%
Ex1-02
100
35
5
95.3%
206%
Ex1-03
100
35
10
95.7%
144%
Ex1-04
100
35
20
98.4%
53%
Ex1-05
100
35
30
98.7%
45%
Ex1-06
100
35
35
98.4%
47%
Ex1-07
100
35
40
97.6%
46%
Ex1-08
100
35
50
96.9%
38%
Ex1-09
100
35
75
92.4%
45%
Ex1-10
100
35
100
88.5%
53%
Ex1-11
100
35
200
84.6%
47%
[0152] It has been surprisingly shown that when the topiramate and glyceryl behenate are mixed with more than 20 parts of hydroxypropylmethylcellulose and the mixture were stressed by mimicing the high temperature and long term storage condition, the concentration of the impurity A is less than that in the samples contained less HPMC or no HPMC. The rate of impurity A growth is very slow in the sample containing a small amount of hydroxypropylmethylcellulose and slower in the sample containing no HPMC. However, when the amount of hydroxypropylmethylcellulose is too high, for example, when the relative amount of hydroxypropylmethylcellulose is 75 parts by weight or more, the active ingredient degraded rapidly. Therefore, when 20 to 50 parts by weight of hydroxypropylmethylcellulose is incorporated in the case of 100 parts by weight of topiramate with glyceryl behenate, it is not only possible to maintain stable and high level of the active ingredient during long term storage, but also slow growth of impurity.
[0153] In addition, the tablets and capsules manufactured from the eleven mixed samples of Ex1-01 to Ex1-11 were analyzed. For each formulation, both the assay of topiramate and the increase of impurity A were reproducible (a difference of no more than 2%).
[0154] Comparative Test 11: referring to the formulations of Ex1-04, Ex1-06, Ex1-08 in the Example 1 above, the hydroxypropylmethylcellulose was replaced with the same amount of methylcellulose, hydroxypropylcellulose, or hydroxyethylcellulose, nine samples were obtained and tested in the same manner as in Test Method Example 3 for stability evaluation. The results showed that the assay (%) of topiramate was in the range of 94 to 97%, but the impurity A was increased by more than 180%, between the ranges of 183 to 252%, which indicated that other cellulose derivatives can not inhibit impurity A growth as hydroxypropylmethylcellulose did.
[0155] Comparative Test 12: referring to the formulations of Ex1-04, Ex1-06, Ex1-08 in the Example 1 above, the same amount of active ingredient, the methylcellulose, hydroxypropylcellulose, or hydroxyethylcellulose were added to the formulation, nine samples were obtained and tested in the same manner as in Test Method Example 3. The results showed that the assay of topiramate was in the range of 95 to 98%, and the increment for impurities A was less than 62%, both in the range of 40 to 62%, which indicated that the addition of the above-mentioned cellulose derivatives did not affect the action of HPMC.
Example 2
Preparation of a Solid Pharmaceutical Combination Comprising Topiramate
[0156] According to the table 2, sample number Ex2-01 to Ex2-11, there were eleven blends that were prepared with different content of topiramate, glyceryl behenate, and hydroxypropylmethylcellulose(HPMC). The preparation of the mixed sample was as follows: (1) each material was milled into fine powders that can pass 60 mesh sieves. The formula amount of topiramate, glyceryl behenate and hydroxypropylmethylcellulose were mixed fully to get a powder mixture. Then, the mixture was divided into 2 parts: one part encapsulated into capsule and the other half compressed into tablets.
[0157] The 5-month stability of the tablets manufactured from the eleven samples was evaluated by the method described in Test Method Example 3, and the residual assay (%) of the topiramate and the increment (%) of the impurity A were calculated. The results werelisted as follows in Table 2:
[0000]
TABLE 2
glyc-
hydroxy-
the
eryl
propyl-
the residual
increment
Sample
be-
methyl-
assay of the
of the
No.
Topiramate
henate
cellulose
topiramate
impurity A
Ex2-01
100
35
0
89.4%
271%
Ex2-02
100
35
5
94.5%
213%
Ex2-03
100
35
10
96.2%
136%
Ex2-04
100
35
20
98.7%
57%
Ex2-05
100
35
30
98.3%
44%
Ex2-06
100
35
35
98.5%
48%
Ex2-07
100
35
40
97.3%
43%
Ex2-08
100
35
50
96.4%
36%
Ex2-09
100
35
75
91.6%
43%
Ex2-10
100
35
100
89.3%
50%
Ex2-11
100
35
200
85.7%
49%
[0158] It has been surprisingly shown that when the topiramate and hydroxypropylmethylcellulose were mixed with equal to or more than 20 parts of glyceryl behenate, the concentration of the impurity A which should be controlled strictly is less, when compared with the mixture contains less or no glyceryl behenate. Hence, the rate of increase of impurity A is slow with a certain amount of glyceryl behenate, far less than samples containing no glyceryl behenate. However, when the amount of glyceryl behenate is too high, for example, when the relative amount of glyceryl behenate is more than 50 parts by weight, the amount of active ingredient decreases rapidly. Therefore, when 20 to 50 parts by weight of glyceryl behenate is incorporated in the mixture of 100 parts by weight of topiramate and in the presence of hydroxypropylmethylcellulose, it is not only possible to maintain a high and stable level of the active ingredient during long-term storage, but also slow impurity growth.
[0159] In addition, the tablets and capsules from the eleven mixed samples of Ex2-01 to Ex2-11 were tested. For each formulation, both topiramate assay and the amount of impurity A were reproducible (a difference was no more than 1.5%).
[0160] Comparative Test 21: referring to the formulation of Ex2-04, Ex2-06, Ex2-08 in the Example 2 above, the glyceryl behenate was replaced with the same amount of stearic acid, carnauba wax, or stearyl alcohol, there were nine samples obtained. Samples were tested in the same manner as in Test Method Example 3 for stability evaluation. The results showed that topiramate assay is in the range of 87 to 95%, but the impurity A is more than 194% increments, all were in the range of 194 to 242%, which indicates that stearic acid and other similar lipids can not inhibit impurity growth as combination of glyceryl behenate and hydroxypropylmethylcellulose did.
[0161] Comparative Test 22: referring to the formulation of Ex2-04, Ex2-06, Ex2-08 in the Example 2 above, the equal amount of stearic acid, carnauba wax, or stearyl alcohol as the active ingredient was additionally added to the formulation, a total of nine samples were obtained and examined as the same manner in Test Method Example 4. The results showed that topiramate assay was in the range of 95 to 98%, and the increment for impurities A was less than 60%, all were within the range of 40 to 60%, which indicated that the addition of the above-mentioned lipids did not affect the effect ofglyceryl behenate.
[0162] Comparative Test 23: Four finished products, the market product of topiramate tablets (Chinese Medicine Registration No. H20020557), the topiramate capsule (named as #444 capsules here in this study) based on the formulation and preparation of example 1-3 shown in the instruction of the patent CN1419444A(99803589.0), the pellets (named as #367 pellets here) based on the formulation and preparation of Example 6 (chapter from 0117 to 0127) shown in the instruction from CN102579367B (201210080716.8) and the tablet (named as #501 tablet here) based on the formulation and preparation of example 4 shown in the instruction from CN103417501A (201210162377.8), were placed at the 40 □ condition for 5 months. The data collected shows that assay of topiramate was within the range of 93.4 to 96.7%, which indicated that although it is acceptable, it was not as effective as the present invention; but the increment of the impurities A was in the range of 154 to 232%, which indicated that these products were far less effective than the present invention to slow the increment of the impurity A.
Example 3
Preparation of a Solid Pharmaceutical Combination Comprising Topiramate
[0163] The pharmaceutical compositions in the present invention were prepared according to the formulation shown in the table 3 below.
[0000]
TABLE 3
Ingredient
Weight(mg)
Topiramate
100
mg
Glyceryl behenate
35
mg
HPMC
Prescribed quantity
Microcrystalline cellulose
40
mg
Starch
30
mg
Sodium starch glycolate
5
mg
PVP K30
3
mg
Magnesium stearate
2
mg
[0164] Preparation: The ingredients were milled and passed through a 60 mesh sieve. The active pharmaceutical ingredient, glyceryl behenate, and the prescribed amount of hydroxypropylmethylcellulose were mixed evenly. Then, he microcrystalline cellulose and starch were added onto the mixture and mixed evenly. The above mixed powder was wet granulated with a 5% PVP K30 solution as a binder which prepared by using 50% ethanol to get soft material. Then, the wet granules were dried at 50° C. until the moisture content was less than 2.5%. The dry granules were mixed with the disintegrant and the lubricant evenly and divided in to 2 parts: half of the final blended material encapsulated into the hard capsule shell and the other half compressed into tablets.
[0165] According to the formulation in Table 3, hydroxypropylmethylcellulose was mixed with the amounts (parts by weight) of the topiramate and hydroxypropylmethylcellulose described in Sample of No. Ex3-01 to Ex3-07 listed in Table 4 below. Seven samples of tablets and capsules were obtained.
[0166] The stability of these seven samples was tested by the method in Test Method Example 3 for stability evaluation. The residual assay (%) of topiramate and the increment (%) of impurities A after 5 monthswere calculated. The results are shown in Table 4:
[0000]
TABLE 4
glyc-
the
eryl
the residual
increment
Sample
be-
assay of the
of the
No.
Topiramate
henate
HPMC
topiramate
impurity A
Ex3-01
100
35
0
83.5%
264%
Ex3-02
100
35
5
87.9%
213%
Ex3-03
100
35
20
96.4%
63%
Ex3-04
100
35
35
98.3%
68%
Ex3-05
100
35
50
95.9%
54%
Ex3-06
100
35
75
91.2%
67%
Ex3-07
100
35
100
86.5%
65%
[0167] The results show that even if other conventional excipients were added, these tablets still had a typical correlation with the amount of hydroxypropylmethylcellulose added in both the residual assay (%) of topiramate and the increment (%) of impurity A. Both these two parameters were not acceptable when the samples had less or no HPMC (<20 parts by weight), and when the amount of hydroxypropylmethylcellulose was too high (>50 parts by weight), the active ingredient assay was still not acceptable. When 20 to 50 parts by weight of hydroxypropylmethylcellulose was incorporated with respect to 100 parts by weight of topiramate, not only the active ingredient can be maintained at a high stable level during the long term storage, but also the impurity growth is slow.
Example 4
Preparation of a Solid Pharmaceutical Combination Comprising Topiramate
[0168] The pharmaceutical compositions in the present invention were prepared according to the formulation shown in the table 5 below.
[0000]
TABLE 5
Ingredient
Weight(mg)
Topiramate
100
mg
Glyceryl behenate
Prescribed quantity
HPMC
35
mg
Microcrystalline cellulose
40
mg
Starch
30
mg
Sodium starch glycolate
5
mg
PVP K30
3
mg
Magnesium stearate
2
mg
[0169] Preparation: The materials were milled and passed through a 60 mesh sieve. The active pharmaceutical ingredient, hydroxypropylmethylcellulose, and the prescribed amount of glyceryl behenate were mixed evenly. Then, microcrystalline cellulose as filler with starch was added and mixed evenly. The above mixed powder is wet granulated with a 5% PVP K30 solution as a binder which prepared by using 50% ethanol to get soft material. Then the wet granules were dried at 50° C. until the moisture content was less than 2.5%. The dry granules were mixed with the disintegrant and the lubricant evenly, and divided in to 2 parts: half of the final blended materials encapsulated into the hard capsule shell and the other half compressed into tablets.
[0170] According to the formulation in Table 6, glyceryl behenate was mixed with the amount of topiramate and glyceryl behenate described in Sample No. Ex4-01 to Ex4-07 listed below, and the seven mixture samples of tablets and capsules were obtained.
[0171] The stability of these seven samples was tested by the method of Test Method Example 4 for stability evaluation. The residual assay (%) of topiramate and the increment (%) of impurities A after 6 months were calculated. The results are shown in Table 6:
[0000]
TABLE 6
glyc-
the
eryl
the residual
increment
Sample
be-
assay of the
of the
No.
Topiramate
henate
HPMC
topiramate
impurity A
Ex4-01
100
35
0
93.5%
242%
Ex4-02
100
35
5
94.4%
194%
Ex4-03
100
35
20
96.3%
66%
Ex4-04
100
35
35
96.7%
55%
Ex4-05
100
35
50
96.3%
59%
Ex4-06
100
35
75
92.3%
64%
Ex4-07
100
35
100
87.2%
56%
[0172] The results show that even if other conventional excipients were added, these tablets still had a typical correlation with the amount of glyceryl behenate added in both the residual assay (%) of topiramate and the increment (%) of impurity A. Both these two parameters were not acceptable when the samples had less or no HPMC (<20 parts by weight) added, and when the amount of glyceryl behenate was too high (>50 parts by weight), the active ingredient assay was still not acceptable. When 20 to 50 parts by weight of glyceryl behenate was incorporated with respect to 100 parts by weight of topiramate, not only the active ingredient can be maintained at a high stable level during the long term storage, but also the impurity growth is slow.
Example 5
Preparation of a Solid Pharmaceutical Combination Comprising Topiramate
[0173]
[0000]
Ingredient
Weight(mg)
Topiramate
100
mg
Glyceryl behenate
35
mg
HPMC
35
mg
Microcrystalline cellulose (filler)
100
mg
PVP(binder, use 50% alcohol to get a solution
5
mg
with 5% concentration PVP)
Croscarmellose sodium (disintegrant)
8
mg
PEG6000(lubricant)
2
mg
[0174] Preparation: The materials were milled and passed through 60 mesh sieve. The active pharmaceutical ingredient, glyceryl behenate, and hydroxypropylmethylcellulose were mixed evenly. Then, the filler was added and mix evenly. The above blend was granulated with binder and dried at 50° C. until the moisture content was less than 2.5%. The granules were remixed with the disintegrant and the lubricant and divided into 2 parts: half of the blend materials encapsulated into the hard capsule shell and the other half compressed into tablets. Half of the compressed tablets was directly sealed and packaged as core tablets; and the other half of tablets were coated with Opadry® 85F20694 with the coating material account for 3% of the total weight of the final tablets.
[0175] The capsules, core tablets and coated tablets obtained in this example were sealed and tested for stability evaluation by the method in Test Method 3. The results showed that the residual assay of topiramate in capsules, core tablets and coated tablets was within the range of 97.3˜98.2%, and the increment of impurity A was within the range of 45˜60%, which indicated that these preparations have good chemical stability.
Example 6
Preparation of a Solid Pharmaceutical Combination Comprising Topiramate
[0176]
[0000]
Ingredient
Weight(mg)
Topiramate
100
mg
Glyceryl behenate
20
mg
HPMC
50
mg
Microcrystalline cellulose (filler)
40
mg
Corn starch (filler)
20
mg
PEG2000(binder, use water to get a solution with
5
mg
5% concentration PEG2000)
Crosslinked Polyvinylpyrrolidone (disintegrant)
8
mg
Colloidal silica (lubricant)
2
mg
Magnesium stearate (lubricant)
1
mg
[0177] Preparation: The materials were milled and passed through 60 mesh sieve. The active pharmaceutical ingredient, glyceryl behenate, and hydroxypropylmethylcellulose were mixed evenly. Then the filler was added and mixed evenly. The above mixed powder was wet granulated with a binder. Then, the granules were dried at 50° C. until the moisture content was less than 2.5%. The resulting dry granules were mixed with the disintegrant and the lubricant, and divided into 2 parts: half of the blend encapsulated into the hard capsule shell and the other half compressed into tablets. Half of the resulting tablets were directly sealed and packaged as a core tablet and the other half of the tablets were coated with Opadry®85F23452 with the coating material account for 3% of the total weight of the final tablets.
[0178] The capsules, core tablets, and coated tablets obtained in this example were sealed and tested for stability evaluation by the method of Test Method 3. The results showed that assay of topiramate in capsules, core tablets, and coated tablets were in the range of 96.5˜98.2%, and the increment of impurity A were in the range of 45˜55%, which indicated thatthepreparations have good chemical stability.
Example 7
Preparation of a Solid Pharmaceutical Combination Comprising Topiramate
[0179]
[0000]
Ingredient
Weight(mg)
Topiramate
100
mg
Glyceryl behenate
50
mg
HPMC
20
mg
Corn starch(filler)
60
mg
Water(binder)
Appropriate amount
Lowly substituted hydroxypropylcellulose
5
mg
(disintegrant)
Magnesium stearate (lubricant)
2
mg
[0180] Preparation: The materials were milled and passed through 60 mesh sieve. The active pharmaceutical ingredient, glyceryl behenate, and hydroxypropylmethylcellulose were mixed evenly. Then, the filler was added and mixed evenly. The above mixed powder was wet granulated with a binder. The wet granules were dried at 50° C. until the moisture content was less than 2.5%. The dry granules were mixed with the disintegrant and the lubricant, and divided into 2 parts: half of the material encapsulated into the hard capsule shells and the other half of compressed into tablets. Half of the tablets were then directly sealed and packaged as core tablets; and the other half of the tablets were coated with Opadry®85F32004 with the coating material account for 3% of the total weight of the final tablets.
[0181] The capsules, core tablets, and coated tablets obtained in this example were sealed and tested for stability evaluation by the method of Test Method 3. The results showed that assay of topiramate in capsules, core tablets, and coated tablets were within the range of 96.5˜97.8%, and the increment of impurity A were within the range of 44˜56%, which indicated that these preparations have good chemical stability.
[0182] In addition, referring to the formulation and preparation in the example 7 above, the glyceryl behenate is replaced by an equal amount of glyceryl behenate with monoester content more than 95%, glyceryl behenate with diester content more than 95%, or glyceryl behenate with triglyceride content more than 95%, to obtain three kinds of coated tablets which were numbered as Ex71, Ex72, Ex73 respectively. The three kinds of coated tablets were sealed and tested for stability evaluation according to the method of test method 4. The results showed that the residual assay of topiramate in these three coated tablets were all in the range of 96.6˜97.7%, and the increment of impurity A were all in the range of 43˜55%, which indicated that these preparations have good chemical stability.
Example 8
Investigation of Drug Properties
[0183] The tablets prepared from Ex1-06, Ex2-06, Ex3-04, Ex4-04, Example 5, Example 6, Example 7 were tested for dissolution, using 900 ml of water as the release medium with paddle at 50 rpm. The results showed that the release amount of the active from the tablets were in the range of 15 to 45% at 1 hour, and the release amount were in the range of 30 to 60% at 4 hours, and the release amount were in the range of 50 to 80% at 8 hours, and the release amount were in the range of 70 to 100% at 12 hours. This indicated that the solid pharmaceutical compositions of the present invention were capable of exhibiting sustained release characteristics.
Example 9
A Combination of a Medication That Has a Conventional Release Performance and a Medication That Has a Sustained Release Performance
[0184] Formulation 5a: According to the formulation and preparation of Example 5, the formulation was compressed into a tablet containing topiramate 20 mg and this tablet has a sustained release property.
[0185] Formulation 5b: According to the formulation and preparation of Example 5, glyceryl behenate and hydroxypropylmethylcellulose were not added. The formulation was compressed into tablets containing topiramate 20 mg, and the tablets had an immediate release property. That is, when using 900 ml of water as the release medium and paddling at 50 rpm speed to determine drug dissolution, more than 78% of the drug was released at 45 minutes.
[0186] Four tablets obtained from Formulation 5a and one tablet obtained from Formulation 5b were encapsulated into a hard capsule shell as a solid formulation having the characteristics described in any example of the solid pharmaceutical agents described in the fourth aspect of the present invention.
Example 10
A Combination of a Medication That Has a Conventional Release Property and a Medication That Has a Sustained Release Property
[0187] Formulation 6a: According to the formulation and preparation of Example 6, the formulation was compressed into a tablet containing topiramate 20 mg and this tablet has a sustained release property.
[0188] Formulation 6b: According to the formulation and preparation of Example 6, glyceryl behenate and hydroxypropylmethylcellulose were not added. The formulation was compressed into tablets containing topiramate 20 mg and the tablets had an immediate release property. That is, when using 900 ml of water as the release medium and paddling at 50 rpm speed to determine drug dissolution, more than 73% of the drug was released at 45 minutes.
[0189] Two tablets obtained from Formulation 6a and two tablets obtained from Formulation 6b were encapsulated into a hard capsule shell as a solid formulation having the characteristics described in any one example of the fourth aspect of the present invention.
Example 11
A Combination of a Medication That Had a Conventional Release Performance and a Medication That Had a Delayed Release Performance
[0190] Formulation 7a: According to the formulation and preparation of Example 7, the formulation was compressed into a tablet containing topiramate 20 mg and this tablet has a sustained release property.
[0191] Formulation 7b: According to the formulation and preparation of Example 7, glyceryl behenate and hydroxypropylmethylcellulose were not added. The formulation was compressed into tablets containing topiramate 20 mg, and the tablets had an immediate release property. That is, when using 900 ml of water as the release medium and paddling at 50 rpm speed to determine drug dissolution, more than 78% of the drug was released at 45 minutes.
[0192] The five tablets obtained from Formulation 7a and one tablet obtained from Formulation 7b are encapsulated into a hard capsule shell as a solid formulation having the characteristics described in any example of the solid pharmaceutical agents described in the fourth aspect of the present invention.
[0193] For Examples 9 to 11, the immediate release tablets and the sustained release tablets may be made into pellets, respectively. The pellets of these two release properties may be encapsulated into hard capsule shells in proportion as a solid formulation having the characteristics described in any example of the solid pharmaceutical agents described in the fourth aspect of the present invention.
[0194] In addition, for Examples from 9 to 11, it was also possible to compress the immediate release portion and the sustained release portion into a double layer tablet using a bi-layer tablet press, and similarly obtain a composition having the characteristics described in any example of the solid pharmaceutical agents described in the fourth aspect of the present invention.
INDUSTRY APPLICABILITY
[0195] The present invention provides a pharmaceutical composition comprising topiramate. The topiramate solid pharmaceutical composition of the present invention can be used as monotherapy for patients newly diagnosed with epilepsy or for epilepsy patients who have been previously treated with combination agents, and it can also be used for adult and for children of 2-16 year old as an add-on treatment for partial seizures. | The present invention relates to a pharmaceutical composition comprising topiramate, and more particularly, to a solid pharmaceutical composition comprising topiramate, a cellulose derivative, a lipid and optional pharmaceutical excipients, wherein the weight ratio of topiramate to the cellulose derivative is 100:10 to 100. The pharmaceutical compositions of the present invention have excellent formulation properties as well. The pharmaceutical compositions of the present invention can be used for monotherapy for patients who are newly diagnosed with epilepsy, or patients who have been previously treated with combination therapy and now for monotherapy. They can also be used for the add-on treatment of partial seizures in adults and children aged 2 to 16 years.
PCT Published Abstract
A solid pharmaceutical composition comprising topiramate and a process for the preparation thereof comprising:a topiramate, a cellulose derivative, a lipid and optionally a pharmaceutical adjuvant, wherein the weight ratio of topiramate to the cellulose derivative is 100:10˜100. | 0 |
FIELD OF THE INVENTION
[0001] The invention pertains to the field of aqueous adhesion promoter compositions.
DESCRIPTION OF THE PRIOR ART
[0002] Adhesion promoter compositions have been used for a long time to improve adhesion. Such compositions typically are based on organosilanes. Adhesion promoter compositions of this kind are used more particularly as primers, i.e., as an adhesion-enhancing undercoat. Compositions of this kind or primers typically contain inert, highly volatile solvents, in order to ensure rapid flashoff. Solvents, however, especially those referred to as VOCs (Volatile Organic Compounds) are increasingly coming under fire, and increasingly the market is calling for low-solvent, and especially solvent-free, or VOC-free, adhesion promoter compositions.
[0003] Aqueous adhesion promoter compositions are known. However, they are not without their disadvantages. EP-A-0 577 014, for instance, describes an aqueous primer containing an aminosilane or a mercaptosilane. WO 2005/093002 A1 discloses two-component adhesion promoter compositions, which in one preferred embodiment constitute an aqueous adhesion promoter composition comprising a mixture of an alkyl-trialkoxysilane with an aminoalkyl-trialkoxysilane and/or mercaptoalkyl-trialkoxysilane.
[0004] In the context of the present invention, however, it has surprisingly emerged that, in mixtures of this kind, the adhesion to glass, particularly after water storage, is greatly impaired when the fraction of alkylsilane exceeds a certain level.
[0005] One particularly important field of use of the adhesion promoter composition is in vehicle construction, particularly in the installation of glazing, i.e., the bonding of glazing sheets to vehicle bodies. The glazing sheets of the most recent generation feature integrated aerials and consequently, in the edge region of the sheet—where the adhesive is applied—feature surfaces of silver, silver-based compositions or alloys. On these surfaces, however, a major part of the polyurethane adhesives that are used have adhesion problems, even utilizing known adhesion promoter compositions.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention, therefore, to provide aqueous compositions which overcome the disadvantages of the prior art. Surprisingly it has now been found that aqueous adhesion promoter compositions of claim 1 achieve this object.
[0007] It has emerged, surprisingly, that, in the context of their use for moisture-curing one-component polyurethane adhesives, the adhesion promoter compositions of the invention result in effective adhesion to a multiplicity of substrates. In particular is has been possible to show that aqueous adhesion promoter compositions of this kind lead to effective adhesion on glass, ceramic, and silver, and silver-based compositions.
[0008] More particularly it has been found that the use of mercaptosilanes leads to a great improvement in the adhesion to silver, or to silver-based compositions or alloys.
[0009] This is especially important in vehicle construction for the installation using polyurethane adhesives of glazing sheets with an integrated aerial that contain regions of such surfaces.
[0010] It has further been found that very storage-stable adhesion promoter compositions of the invention can be formulated.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The present invention provides aqueous adhesion promoter compositions which comprise at least one aminosilane of the formula (I) or at least one aminosiloxane AS obtained from a condensation reaction of an aminosilane of the formula (I) with at least one further silane, and also at least one mercaptosilane of the formula (II) and either which has an alkylsilanes content of 0% to 45% by weight, more particularly 0% to 25% by weight, based on the weight of the aminosilane or aminosiloxane AS, or in which the ratio of the number of moles of alkylsilanes to the number of moles of aminosilane or aminosiloxane AS amounts to a value of 0-0.60, more particularly 0-0.33.
[0000]
where
R 1 is an n-valent organic radical having at least one primary and/or secondary amino group,
R 1′ is an m-valent organic radical having at least one mercapto group,
R 2 and R 2′ each independently are H or an alkyl group having 1 to 4 C atoms or are an acyl group;
R 3 and R 3′ each independently are H or are an alkyl group having 1 to 10 C atoms;
a and b each independently stand for a value of 0, 1 or 2;
and n and m each independently stand for the values 1, 2, 3, and 4.
[0019] The term “each independently” that is used herein denotes here not only “independently of the other ingredients” but also “independently within the same molecule”. Thus, for example, hydroxy-dimethoxy-aminosilanes (R 2 =methyl, R 2 =methyl, R 2 =H) are also possible.
[0020] Throughout the present document the terms “organosilanes” refer to silanes which contain at least one organic radical which is attached via an Si—C bond to the silicon atom. “Alkylsilanes” are organosilanes whose organic radical is a hydrocarbon group. These alkylsilanes contain no further organic radicals, attached via C—Si bonds, with functional groups having heteroatoms, such as amino groups or mercapto groups. “Aminosilanes” and “mercaptosilanes” are, respectively, organosilanes whose organic radical has an amino group or a mercapto group. In accordance with this definition, accordingly, “tetraalkoxysilanes” are not organosilanes. The term “aminosiloxane” refers to compounds which contain at least one Si—O—Si bond and have at least two organic radicals which are attached via an Si—C bond to the silicon atoms. At least one of these organic radicals in this case has an amino group.
[0021] The composition contains at least one aminosilane of the formula (I) or an aminosiloxane AS obtained from a condensation reaction of an aminosilane of the formula (I) with at least one further silane. Particular preference is given to alkoxysilanes, i.e. aminosilanes of the formula (I) in which R 2 is an alkyl group having 1 to 4 C atoms. Particularly preferred are methoxysilanes (R 2 =methyl) and ethoxysilanes (R 2 =ethyl). Aminosilanes with trialkoxy groups (a=0), more particularly trimethoxysilane groups, have proven particularly advantageous.
[0022] In the presence of water it is possible for alkoxysilanes to undergo hydrolysis, and silanols are formed, i.e., silanes with Si—OH moieties (R 2 =H). In this case it is possible in particular for partially hydrolyzed products to be formed as well. As an end stage of such hydrolysis reactions there are silanetriols.
[0023] Particularly suitable aminosilanes are aminosilanes which are selected from the group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyl-dimethoxymethylsilane, 3-amino-2-methylpropyltrimethoxysilane, 4-aminobutyl-trimethoxysilane, 4-aminobutyldimethoxymethylsilane, 4-amino-3-methylbutyl-trimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, 4-amino-3,3-di-methylbutyldimethoxymethylsilane, 2-aminoethyltrimethoxysilane, 2-amino-ethyldimethoxymethylsilane, aminomethyltrimethoxysilane, aminomethyldimethoxymethylsilane, aminomethylmethoxydimethylsilane, N-methyl-3-aminopropyltrimethoxysilane, N-ethyl-3-aminopropyltrimethoxysilane, N-butyl-3-aminopropyltrimethoxysilane, N-cyclohexyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methyl-3-amino-2-methylpropyltrimethoxysilane, N-ethyl-3-amino-2-methylpropyltrimethoxysilane, N-ethyl-3-aminopropyldimethoxymethylsilane, N-phenyl-4-aminobutyltrimethoxysilane, N-phenylaminomethyldimethoxymethylsilane, N-cyclohexylaminomethyldimethoxymethylsilane, N-methylaminomethyldimethoxymethylsilane, N-ethyl-aminomethyldimethoxymethylsilane, N-propylaminomethyldimethoxymethyl-silane, N-butylaminomethyldimethoxymethylsilane; N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane, bis(trimethoxysilylpropyl)amine, and also their analogs with ethoxy or isopropoxy groups in place of the methoxy groups on the silicon.
[0024] In one embodiment the aminosilane of the formula (I) is an aminosilane of the formula (V)
[0000] H 2 N—R 5 —Si(OR 2 ) (3-a) (R 3 ) a (V)
[0025] where R 5 is a linear or branched alkylene group having 1 to 6 C atoms, more particularly propylene. Considered particularly preferred in this context is 3-aminopropyltrimethoxysilane.
[0026] In one preferred embodiment the aminosilane of the formula (I) contains secondary amino groups. In particular these aminosilanes are of the formula (VI) or (VII) or (VIII).
[0000]
[0000] where R 5 is a linear or branched alkylene group having 1 to 6 C atoms, more particularly propylene. Those which have shown themselves to be particularly preferred are N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane and bis(trimethoxysilylpropyl)amine.
[0027] It has emerged as being particularly advantageous if there are two or more aminosilanes of the formula (I) in the composition. Preferably at least one of the aminosilanes has the formula (VI).
[0028] In one embodiment the composition contains aminosiloxanes AS. These aminosiloxanes are obtained from a condensation reaction of an aminosilane of the formula (I) with at least one further silane. To the person skilled in the art it is clear that the silanes involved in the condensation ought preferably to be hydrolyzed or at least partly hydrolyzed. Silanes involved are preferably alkylsilanes in particular. The product in this case is an aminosiloxane which as well as amino groups additionally contains alkyl groups. The degree of condensation may vary. There may be dimers, trimers or oligomers. The aminosiloxanes AS may also contain alkoxysilane groups. The aminosiloxanes AS can preferably be dispersed or are miscible or soluble in water. Aminosiloxanes AS of this kind are available commercially in the form, for example, of Dynasylan® HDYROSIL 2627, Dynasylan® HDYROSIL 2776 or Dynasylan® HDYROSIL 2929 from Degussa AG, Germany.
[0029] The composition contains at least one mercaptosilane of the formula (II). Particular preference is given to alkoxysilanes, i.e., mercaptosilanes of the formula (II) in which R 2′ is an alkyl group having 1 to 4 C atoms. Particular preference is given to methoxysilanes (R 2′ =methyl) and ethoxysilanes (R 2′ =ethyl). Mercaptosilanes with trialkoxy groups (b=0), especially trimethoxysilane groups, have proven particularly advantageous.
[0030] In the presence of water it is possible for alkoxysilanes to undergo hydrolysis, forming silanols, i.e., silanes with Si—OH moieties (R 2′ =H). In this case it is possible in particular for the products to include partially hydrolyzed products. The end stage of such hydrolysis reactions are silanetriols.
[0031] The mercaptosilane of the formula (II) preferably has the formula (IX):
[0000] HS—R 5′ —Si(OR 2′ ) (3-b) (R 3′ ) b (IX)
[0032] where R 5′ is a linear or branched alkylene group having 1 to 6 C atoms, more particularly propylene.
[0033] Particularly preferred mercaptosilanes are 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.
[0034] Additionally the aqueous adhesion promoter composition in one alternative has an alkylsilanes content of 0% to 45% by weight, more particularly 0% to 25% by weight, based on the weight of the aminosilane or the aminosiloxane. Alternatively the ratio of the number of moles of alkylsilanes to the number of moles of aminosilane or aminosiloxane AS in the aqueous adhesion promoter composition amounts to a value of 0-0.60, more particularly 0-0.33. If the alkylsilanes content is greater, the adhesion, particularly to glass, becomes increasingly worse. Preferably, however, the aqueous adhesion promoter composition is free of alkylsilanes. Alkylsilane-free aqueous adhesion promoter compositions of this kind exhibit effective adhesion both to glass and to silver or to silver-based compositions.
[0035] Alkylsilanes are, in particular, alkylsilanes of the formula (III):
[0000] R 1″ —Si(OR 2″ ) (3-c) (R 3″ ) c (III); where R 1″ is a saturated or unsaturated alkyl group or aryl or aralkyl group; R 2″ independently at each occurrence is H or an alkyl group having 1 to 4 C atoms or is an acyl group; R 3″ independently at each occurrence is H or is an alkyl group having 1 to 10 C atoms; and c is a value of 0, 1 or 2.
[0041] It has been found that alkylsilanes adversely affect the adhesion to glass.
[0042] Additionally it is preferred for the aqueous adhesion promoter composition to be substantially free, preferably free, of organosilanes OS whose organic radical which is attached via an Si—C bond to the silicon atom contains at least one functional group that is able to react with the amino group of the aminosilane of the formula (I) or of the aminosiloxane AS or with the mercapto group of the mercaptosilane of the formula (II).
[0043] With particular preference the aqueous adhesion promoter composition is substantially free, preferably free, of organosilanes whose organic radical which is attached via an Si—C bond to the silicon atom contains hydroxyl groups.
[0044] By “substantially free” here is meant an amount of less than 3% by weight, more particularly of less than 1% by weight, based on the weight of the aqueous composition.
[0045] It has, however, proven particularly advantageous for the aqueous adhesion promoter composition further to comprise at least one tetraalkoxysilane of the formula (IV)
[0000] Si(OR 4 ) 4 (IV)
[0046] where R 4 each independently is H or an alkyl group having 1 to 4 C atoms or is an acyl group, especially acetyl group. Examples of such tetraalkoxysilanes are tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrapropoxysilane, tetrabutoxysilane, and tetraacetoxysilane. Tetraethoxysilane has proven particularly preferred.
[0047] The aqueous composition may be comprised of further constituents. Such additional constituents are surfactants, acids, catalysts, cosolvents, biocides, antisettling agents, stabilizers, inhibitors, pigments, dyes, corrosion inhibitors, odorants, UV indicators, thixotropic agents, fillers, defoamers, further organosilanes, titanates, and the like.
[0048] Cosolvents are understood to be water-miscible solvents, such as alcohols or ethers or ketones, for example. It is preferred, however, for such solvents to be used only in a small amount, i.e., typically less than 10% by weight relative to the water. With particular preference the composition—apart from traces of alcohols which come about from the hydrolysis of the alkoxysilanes used in the aqueous composition—is free from such cosolvents. If a relatively large amount of solvent is used, the VOC problems are intensified, whereas avoiding VOCs is actually a principal reason for using aqueous compositions.
[0049] Surfactants are preferably additional constituents of the aqueous composition.
[0050] Surfactants which can be used include natural or synthetic substances which, in solutions, lower the surface tension of the water or of other liquids. Surfactants which can be used, also called wetting agents, include anionic, cationic, nonionic, and ampholytic surfactants or mixtures thereof.
[0051] Examples of anionic surfactants are surfactants containing carboxylate, sulfate, phosphate or sulfonate groups, such as, for example, amino acid derivatives, fatty alcohol ether sulfates, fatty alcohol sulfates, soaps, alkylphenol ethoxylates, fatty alcohol ethoxylates, and also alkanesulfonates, olefinsulfonates or alkyl phosphates.
[0052] The nonionic surfactants include, for example, ethoxylates, such as, for example, ethoxylated adducts of alcohols, such as polyoxyalkylene polyols, amines, fatty acids, fatty acid amides, alkylphenols, ethanol amides, fatty amines, polysiloxanes or fatty acid esters, and also alkyl or alkylphenyl polyglycol ethers, such as fatty alcohol polyglycol ethers, or fatty acid amides, alkylglycosides, sugar esters, sorbitan esters, polysorbates or trialkylamine oxides, but also esters and amides of poly(meth)acrylic acids, with polyalkylene glycols or aminopolyalkylene glycols, which may be capped at not more than one end with alkyl groups.
[0053] Examples of cationic surfactants are quaternary ammonium or phosphonium compounds, such as tetraalkylammonium salts, N-,N-dialkyl-imidazoline compounds, dimethyldistearylammonium compounds, or N-alkyl-pyridine compounds, especially ammonium chlorides.
[0054] The ampholytic or amphoteric surfactants include amphoteric electrolytes, known as ampholytes, such as aminocarboxylic acids, for example, and betaines.
[0055] Surfactants of this kind are widely available commercially.
[0056] Particular suitability is possessed by alkoxylated alcohols. Those which have shown themselves to be suitable include, in particular, alkoxylated nonionic fluorosurfactants, especially Zonyl® FSO-100, which is available commercially from ABCR, Germany, and alkoxylated alcohols or alkoxylated alkylphenols, especially Antarox FM 33, which in commercial terms is available commercially from Rhodia.
[0057] Additionally very preferred are alkoxylated fatty alcohols, particularly the one commercialized by Cognis as Hydropalat® 120.
[0058] Acids are likewise preferred additional constituents of the aqueous composition. The acid may be organic or inorganic. Organic acids are, on the one hand, carboxylic acids, especially a carboxylic acid selected from the group encompassing formic, acetic, propionic, trifluoroacetic, oxalic, malonic, succinic, maleic, fumaric, and citric acid, and also amino acids, especially aspartic acid and glutamic acid. Preferred acids are those which have a pK a of between 4.0 and 5. By “pK a ” the chemist means, as is known, the negative base-ten logarithm of the acid dissociation constant K a : pK a =−log 10 K a .
[0059] A preferred carboxylic acid is acetic acid.
[0060] Organic acids are on the other hand, in particular, those which contain a sulfur atom or a phosphorus atom. Organic acids of this kind are, in particular, organic sulfonic acids. An organic sulfonic acid is one of the compounds which contains an organic radical containing carbon atoms and also at least one functional group —SO 3 H.
[0061] The aromatic sulfonic acid may be monocyclic or polycyclic and there may be one or more sulfonic acid groups present. Examples of such include 1- or 2-naphthalenesulfonic acid, 1,5-naphthalenedisulfonic acid, benzenesulfonic acid or alkylbenzenesulfonic acids.
[0062] Preferred aromatic acids are those which have the formula (X)
[0000]
[0063] R in this formula is an alkyl radical having 1 to 18 atoms. Preferably R is a methyl or dodecyl group, more particularly a dodecyl group.
[0064] The acid may further be an inorganic acid. Inorganic acids which have shown themselves to be suitable are more particularly those which contain a sulfur atom or a phosphorus atom.
[0065] Acids containing phosphorus atoms are, in particular, phosphoric acid, phosphorous acid, phosphonic acid, and phosphonous acid.
[0066] Acids containing sulfur atoms are, in particular, sulfuric acids, especially sulfuric acid, sulfurous acids, persulfuric acid, disulfuric acid (i.e., pyrosulfuric acid), disulfurous acid, dithionic acid, dithionous acid, thiosulfuric acid or thiosulfurous acid.
[0067] In one preferred embodiment the aqueous adhesion promoter composition is composed of water, at least one aminosilane of the formula (I), at least one mercaptosilane of the formula (II), if desired, at least one tetraalkoxysilane, and also the possible hydrolysis and/or condensation products thereof.
[0068] In another preferred embodiment the aqueous adhesion promoter composition is composed of water, at least one aminosilane of the formula (I), at least one mercaptosilane of the formula (II), at least one surfactant, at least one acid, if desired, at least one tetraalkoxysilane, and also of the possible hydrolysis and/or condensation products thereof.
[0069] In another preferred embodiment the aqueous adhesion promoter composition is composed of water, at least one aminosilane of the formula (I), at least one mercaptosilane of the formula (II), and, if desired, a surfactant and an acid, more particularly an organic acid, and also of the possible hydrolysis and/or condensation products thereof.
[0070] In the aqueous adhesion promoter composition the weight fraction of the total of aminosilane of the formula (I), aminosiloxane AS, mercaptosilane of the formula (II), and water and also, if present, tetraalkoxysilane of the formula (IV) is advantageously more than 80% by weight, in particular more than 90% by weight, based on the weight of the aqueous adhesion promoter composition.
[0071] The weight fraction of the total of aminosilane of the formula (I), aminosiloxane AS, mercaptosilane of the formula (II) total and—if present—tetraalkoxysilane of the formula (IV) is advantageously more than 0.1% by weight, more particularly between 0.1% and 10% by weight, preferably between 0.1% and 5% by weight, most preferably between 0.5% to 2% by weight, based on the weight of the aqueous adhesion promoter composition.
[0072] The weight ratio of the sum of aminosilane of the formula (I) and aminosiloxane AS to mercaptosilane of the formula (II) is advantageously 1:10 to 10:1, more particularly 1:2 to 2:1, preferably 1:1.5 to 1.5:1.
[0073] The aqueous adhesion promoter composition is preferably in the form of a two-component composition composed of a first component K 1 and a second component K 2 . In this case it is advantageous if the first component K 1 comprises at least the aminosilane of the formula (I) or at least the aminosiloxane AS and the mercaptosilane of the formula (II) and—if present—the tetraalkoxysilane of the formula (IV), while the second component K 2 comprises at least water.
[0074] If the composition comprises a surfactant and/or an acid, said surfactant and/or acid may be part of the first component K 1 and/or of the second component K 2 . It is advantageous, however, for the surfactant to be part of the second component K 2 . With further advantage the acid is part of the second component K 2 .
[0075] A further aspect of the present invention is a packaging form. The packaging form is composed of a pack having two chambers, which has chambers separated from one another by at least one partition, and an aqueous two-component adhesion promoter composition as described above. Its first component K 1 is present in the first chamber and its second component K 2 in the second chamber.
[0076] FIGS. 1 a ) and 1 b ) represent, diagrammatically, cross sections through two embodiments. The packaging form 6 is composed of a pack 5 which has chambers 1 , 2 separated from one another by at least one partition 3 ; and of the two-component composition whose first component K 1 is present in the first chamber 1 and whose second component K 2 is present in the second chamber 2 .
[0077] FIG. 1 a ) shows an embodiment in which the partition 3 extends between the two outer walls 4 , 4 ′ of the first and second chambers 1 , 2 .
[0078] FIG. 1 b ) shows an embodiment in which the first chamber 1 is sited within the second chamber 2 and therefore the first chamber 1 is surrounded completely by the second chamber, and the first chamber 1 is bounded completely by the partition 3 .
[0079] Packaging forms of this kind are very well suited to the storage of the two-component adhesion promoter compositions. When needed, the two components can be mixed prior to application. If the partition 3 is fabricated from a material which ruptures or tears as a result of application of pressure, the mixing can be accomplished by applying a pressure to the outer walls 4 , 4 ′, whereby the partition 3 can be made to rupture or burst. Application of the pressure is typically done by the action of force. This action of force is preferably a striking action or bending of the pack. The material of the partition 3 is typically fabricated from glass, from aluminum, from aluminum alloy, from a thin plastic or from a composite material. The partition 3 must be fabricated in a thickness such that it does not rupture as a result of an unintended exposure to force, of the kind occurring typically, for example, in the course of transportation. The outer wall 4 , 4 ′ must be such that it does not rupture or tear when the pressure that leads to the rupture of the partition 3 is applied. The outer wall 4 , 4 ′ is fabricated either from a metal or from a flexible plastic. The mixing of the two components may be assisted by shaking. The mixed components can be applied and/or withdrawn through an outlet opening in the outer wall of the pack (not shown in FIGS. 1 a , 1 b ).
[0080] Further suitable embodiments are those as described in WO 2005/093002 A1, more particularly by FIGS. 1 to 11. The packs of WO 2005/093002 are, through incorporation by reference, an integrated part of the present document and may be filled with the aqueous adhesion promoter composition described in detail above, to form packaging forms of the invention.
[0081] The aqueous adhesion promoter composition described is especially suitable as a primer, preferably as a primer for adhesives and sealants. Use of such a primer enhances the adhesion.
[0082] Accordingly the invention also encompasses a method of adhesive bonding or of sealing. Of this method the following three versions are preferred in particular.
[0083] In the first version the method comprises the steps of
i) applying an aqueous adhesion promoter composition as described to a substrate S 1 to be bonded or sealed ii) applying an adhesive or sealant to the flashed-off composition located on the substrate S 1 iii) contacting the adhesive or sealant with a second substrate S 2 .
[0087] In the second version the method comprises the steps of
i′) applying an aqueous adhesion promoter composition as described to a substrate S 1 to be bonded or sealed ii′) applying an adhesive or sealant to the surface of a second substrate S 2 iii′) contacting the adhesive or sealant with the flashed-off composition which is located on the substrate S 1 .
[0091] In the third version the method comprises the steps of
i″) applying an aqueous adhesion promoter composition as described to a substrate S 1 to be bonded or sealed ii″) flashing off the composition iii″) applying an adhesive or sealant between the substrate surfaces S 1 and S 2 .
[0095] In all three versions the second substrate S 2 is composed of the same material as or different material to the substrate S 1 .
[0096] Typically step iii), iii′) or iii″) is followed by a step iv) of curing the adhesive or sealant.
[0097] The adhesive used can in principle be any adhesive. The advantageous improvements to adhesion have, however, been found in particular in the case of adhesives or sealants in which it is a polyurethane adhesive which comprises polyurethane prepolymers containing isocyanate groups. Polyurethane adhesives of this kind are widely available commercially, especially under the name Sikaflex® from Sika Schweiz AG.
[0098] The substrate S 1 and/or S 2 may be diverse in nature. Preferably at least one of the substrates, S 1 or S 2 , is glass or glass ceramic or aluminum or an aluminum alloy.
[0099] With further preference at least one of the substrates, S 1 or S 2 , is silver, more particularly a silver imprint on glass or glass ceramic.
[0100] It has been found that glass and ceramic react less sensitively to the adhesion promoter compositions in comparison to imprinted silver. It is therefore advantageous to use lower silane concentrations on glass and ceramic in order to determine differences in the individual aqueous adhesion promoter compositions between one another.
[0101] As and when necessary, the substrates may be pretreated before the sealant or adhesive is applied. Such pretreatments include, in particular, physical and/or chemical cleaning techniques, examples being abrading, sandblasting, brushing or the like, or treatment with cleaners or solvents, or the application of an adhesion promoter, adhesion promoter solution or primer.
[0102] The method is especially suitable for the adhesive bonding of glazing sheets. In one preferred embodiment, therefore, the substrate S 1 or S 2 , respectively, is glass or glass ceramic and the substrate S 2 or S 1 , is a paint or a painted metal or a painted metal alloy.
[0103] It has emerged in particular that mercaptosilanes lead to a strong improvement in adhesion of one-component polyurethane adhesives to silver or to silver-based compositions or alloys. Particularly good enhancement of adhesion is found on silver.
[0104] On the basis of this method, adhesively bonded articles are produced. Such articles preferably represent a means of transport, more particularly an automobile, bus, truck, rail vehicle, a boat or an aircraft.
[0105] It has emerged that the method described is especially suited to the adhesive bonding of glazing sheets having an integrated aerial. Aerial connection contacts of this kind are typically present on the glazing sheet, in the form of silver or silver-based compositions or alloys, more particularly in the form of silver imprints. Typically, parts of the edge region of the glazing sheet—where the adhesive is applied—feature surfaces of this kind. It is therefore important that the adhesive adheres well not only to glass and glass ceramic but also to silver-based compositions and/or alloys. FIG. 2 shows, diagrammatically, the tail view of an automobile 20 with a new-generation glazing sheet 7 with integrated aerial 12 .
[0106] FIG. 3 shows, diagrammatically, a glazing sheet 7 of this kind with integrated aerial 12 . The silver imprint for the aerial, 11 , is located at different places on the glass ceramic 10 in the edge region of the sheet 7 . Following installation, the aerials 12 are connected via the silver imprints 11 for the aerial, with an aerial connection piece 15 , to the send or receive apparatus (not shown) in the interior of the vehicle 20 . Additionally on the glass ceramic 10 there are also metal imprints 14 for connection to the glazing sheet heating system 13 .
[0107] FIG. 3 a shows an enlargement of an edge region of the sheet 7 with a silver imprint 11 of this kind which is connected to the aerial 12 , and which from the edge is sited into the interior of the sheet, in order to ensure good receiving and/or emitting. The sheet 7 has a glass ceramic imprint 10 in the edge region of the sheet. The polyurethane adhesive 17 is applied in the edge region along the bonding line 16 .
[0108] FIGS. 3 b and 3 c show a cross section through an installed glazing sheet 7 along the cross section A-A, and along the cross section B-B, respectively, in FIG. 3 a . On the glass 8 is the glass ceramic 10 . In FIG. 3 b the polyurethane adhesive 17 is direct with the glass ceramic 10 . In FIG. 3 c the polyurethane adhesive 17 adheres to the silver imprint 11 for the aerial. On the other side the adhesive 17 is connected to the flange 18 of the automobile 20 . The flange 18 is painted with an automobile paint. To ensure the adhesion, in the embodiment shown, a primer 19 is applied to the paint, and so there is a primer layer 19 present between painted flange 18 and adhesive 17 .
[0109] The invention is of course not confined to the exemplary embodiments described and shown. It is understood that the features of the invention identified above can be used not only in the specific combination indicated but also in other modifications, combinations, and versions, or on their own, without departing the scope of the invention.
LIST OF REFERENCE SYMBOLS
[0000]
1 first chamber
2 second chamber
3 partition
4 , 4 ′ outer walls
5 pack
6 packaging form
K 1 first component
K 2 second component
7 glazing sheet
8 glass
9 primer
10 glass ceramic
11 silver imprint for aerial
12 Aerial
13 glazing sheet heating system
14 metal imprint for heating connection
15 aerial connection piece
16 adhesive application line
17 polyurethane adhesive
18 Flange
19 Primer
20 Automobile
EXAMPLES
[0132] Different components K 1 were produced, consisting of the silanes as per the data (parts by weight) in table 1. Components 1 to 9 correspond here to inventive components K 1 , while the components R1 to R10 represent comparative components.
Raw Materials Used:
[0133]
[0000]
“A1120”
N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane
Silquest ® A1120, GE Silicones, Switzerland
“A1170”
Bis(trimethoxysilylpropyl)amine
Silquest ® A1170, GE Silicones, Switzerland
“A1110”
3-Aminopropyltrimethoxysilane
Silquest ® A1110, GE Silicones, Switzerland
“A189”
3-Mercaptopropyltrimethoxysilane
Silquest ® A189, GE Silicones, Switzerland
“TEOS”
Tetraethoxysilane
Fluka Chemie AG, Switzerland
“A171”
Vinyltrimethoxysilane
Silquest ® A171, GE Silicones, Switzerland
“MTMS”
Methyltrimethoxysilane
Fluka Chemie AG, Switzerland
Hydropalat ® 120, Cognis, Germany
“HS 2627”
Dynasylan ® HYDROSIL 2627, Degussa Deutschland
Aminosiloxane, amino-modified alkylpolysiloxane
[0000]
TABLE 1
Compositions of different components K1.
K1:
R1
R2
R3
R4
R5
1
2
3
4
5
6
7
8
9
R6
R7
R8
R9
R10
A1120
1
1
1
1
1
1
1
1
1
1
1
A1170
1
1
1
A1110
1
1
HS2627
1
1
A189
1
1
1
1
1
1
1
1
1
1
1
1
1
TEOS
1
1
1
A171
1
MTMS
1
0.1
0.2
0.4
0.5
1
0.5
[0134] From these different first components K 1 there were then produced, by mixing a second component K 2 , aqueous adhesion promoter compositions.
[0135] The substrates used were as follows
[0136] floatglass (tin side used for adhesion test), Rocholl, Germany
[0137] ESG ceramic, Ferro 14251, Rocholl, Germany
[0138] silver imprint: silver imprint regions on original BMW rear screen, 3 Series (series status July 2006)
[0139] For this purpose, for glass and ceramic as substrates, 0.5% by weight of the respective component K 1 was mixed with 99.5% of a component K 2 - 1 consisting of 0.5 part by weight of Hydropalat® 120, 1 part by weight of acetic acid (100%), and 98 parts by weight of water.
[0140] For silver imprint as the substrate, 1.5% by weight of the respective component K 1 were mixed with 98.5% of a component K 2 - 2 consisting of 0.5 part by weight of Hydropalat® 120, 1 part by weight of acetic acid (100%), and 97 parts by weight of water.
[0141] The aqueous adhesion promoter compositions produced in this way were applied to the respective substrate by means of a cellulose cloth soaked with them (Tela®, Tela-Kimberly Switzerland GmbH) and left to air for 10 minutes, and a triangular bead of Sikaflex®-250 DM-2 (“DM-2”), or Sikaflex®-250 PC-T (“PC-T”), at 23° C. and 50% relative humidity, was applied by means of an extrusion cartridge and nozzle. Both adhesives are one-component, moisture-curing polyurethane adhesives which comprise polyurethane prepolymers containing isocyanate groups, and are available commercially from Sika Schweiz AG.
[0142] The adhesive was tested after a cure time of 6 days of climate chamber storage (‘CS’) (23° C., 50% relative humidity), and also after subsequent water storage (‘WS’) in water at 23° C. for 6 days, and also after subsequent heat/humidity storage (‘HS’) of 6 days at 70° C., 100% relative humidity.
[0143] The adhesion of the adhesive was tested by means of the bead test. For this purpose, the bead is incised at the end just above the adhesion face. The incised end of the bead is held with round-end tweezers and pulled from the substrate. This is done by carefully rolling up the bead on the tip of the tweezers, and placing a cut vertical to the bead pulling direction down to the bare substrate. The rate of bead removal is selected so that a cut has to be made around every 3 seconds. The test length must amount to at least 8 cm. An assessment is made of the adhesive which remains on the substrate after the bead has been pulled off (cohesive fracture). The adhesive properties are evaluated by visual estimation of the cohesive fraction of the adhesion face:
[0144] The higher the fraction of cohesive fracture, the better the estimate of the adhesive bond. Test results with cohesive fractures of less than 50%, and especially less than 40%, are typically considered to be inadequate.
[0000]
TABLE 2
Adhesion results of DM-2 on floatglass for different
aqueous compositions consisting of component
K2-1 and different components K1.
K1:
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
CS
100
90
100
70
50
80
100
80
100
100
WS
5
50
75
20
20
30
30
50
70
20
HS
100
70
75
5
30
100
100
70
100
20
K1:
1
2
3
4
5
6
7
8
9
CS
100
100
100
100
100
100
100
95
100
WS
100
100
100
100
100
100
95
40
100
HS
100
100
100
100
100
100
100
100
90
[0000]
TABLE 3
Adhesion results of DM-2 on ESG ceramic for different aqueous compositions
consisting of component K2-1 and different components K1.
K1:
R1
R2
R3
R4
R5
R10
1
2
3
4
5
6
9
CS
100
100
10
0
5
100
100
100
100
100
100
100
100
WS
100
100
0
0
0
30
100
100
100
100
100
100
100
HS
100
100
10
0
0
10
100
100
100
100
100
100
60
[0000]
TABLE 4
Adhesion results of PC-T on silver coating for
different aqueous compositions consisting of
component K2-2 and different components K1.
K1:
R1
R2
R3
R10
1
2
4
5
9
CS
0
5
0
100
100
100
100
50
100
WS
0
0
0
0
80
90
80
50
100
HS
0
0
0
0
60
50
70
60
20
[0000]
TABLE 5
Adhesion results of DM-2 on silver coating for
different aqueous compositions consisting of
component K2-2 and different components K1.
K1:
R1
R2
R3
R4
R10
1
2
3
4
9
CS
0
5
0
0
0
100
80
50
100
100
WS
0
0
0
0
0
100
50
30
100
30
HS
0
0
0
0
0
0
0
0
0
30
[0145] The adhesion results of tables 2 to 5 show that good adhesion can be achieved simultaneously on glass, silver imprint, and ceramic with the composition of the invention, whereas in the case of the comparative examples there are weaknesses in respect of at least one of these substrates.
[0146] For table 6, aqueous compositions were produced which consist of 2% by weight of silane, or 2% by weight of silane mixture, mixed from the respective silanes in the parts by weight indicated, 0.5% by weight of Hydropalat® 120, 1% by weight of acetic acid (100%), and 96.5% by weight of water.
[0147] The storage stability of these aqueous adhesion promoter compositions was investigated by subjecting the aqueous composition to inspection after different numbers of days of storage at room temperature.
[0148] If the composition was clear, it was rated “OK” and evaluated as good. Where there was a slight turbidity, it was rated with a “st”. Where there was severe turbidity, i.e., a milky appearance, it was rated with a “T”. When there were instances of precipitation, an “A” was recorded. Evaluations with “T” and especially “A” are inadequate. Such compositions can in practice no longer be used as adhesion promoter compositions.
[0000]
TABLE 6
Stability of aqueous adhesion promoter compositions.
Storage time [d]
A1120
A189
0
1
7
14
21
28
R11
1
0
OK
OK
OK
OK
OK
OK
R12
0
1
OK
OK
A
A
A
A
10
1
10
OK
OK
St
A
A
A
11
1
5
OK
OK
OK
T
T
A
12
1
2
OK
OK
OK
st
T
A
13
1
1
OK
OK
OK
st
T
A
14
2
1
OK
OK
OK
OK
OK
OK
[0149] The results from table 6 show that aqueous compositions of mercaptosilanes of the formula (II) exhibit problems with storage stability. The results also show well, however, that by the addition of aminosilanes of the formula (I) it is possible greatly to reduce, or to eliminate, these storage problems. Inventive compositions can be produced which possess excellent storage stability. | Aqueous adhesion promoter compositions include at least one aminosilane and/or aminosiloxane and also at least one mercaptosilane. The adhesion promoter compositions are suitable more particularly as primers or adhesion-promoter undercoats for adhesives and sealants. They are especially suitable for the adhesive bonding of vehicle glazing. Exceptionally high adhesion has been found more particularly with glazing featuring applied silver prints. | 2 |
[0001] This is a Continuation-in-Part application of U.S. patent application Ser. No. 10/443,818 filed on May 23, 2003, which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to magnetic cards or keys for operating magnetic locks.
[0003] Such locks are already known and described for example in European Patents EP 0241323, 0024242, 0498465 and U.S. Pat. No. 3,995,460. The present invention relates to coded magnetic cards to operate such locks as described in the applicant's U.S. Pat. Nos. 3,611,763 and 4,077,242, the latter titled Metal Magnetic Key. Another is U.S. Pat. No. 3,995,460 describing an embodiment with a hole in the card being impaled by a pivoting pin. That pin however impales the card as the card is being inserted and not as the housing is being rotated as is the case in present embodiments to be described in detail herein.
[0004] To operate the prior locks, a coded magnetic card or key is inserted in the lock to unlock the lock and allow a door, gate or other barrier to be opened. Typically, the card must remain in the lock during unlocking but can be removed when the lock is unlocked. An externally exposed slot is provided for the card in a periphery of an exposed rotatable or fixed position body. The body may be, or form part of, a door catch release knob or handle that allows the magnetic card to be slidingly inserted. Without any inserted card, the lock housing with card slot may be free-turning, through 360 degrees. That is, only without an inserted card is the housing free-turning. The card slot may come to rest at a rotational position not convenient for subsequent card insertion. That random position may not be readily adjustable. It is desirable for the slot to be positioned uppermost for most convenient card insertion and easy visibility of the slot. However, when the lock is used externally in a building or in the open, for a gate way, an uppermost slot exposes the inside of the lock to rain, external surface water, debris and dirt so a side or bottom slot position is preferable.
[0005] In certain applications the magnetic card is retained in the lock during unlocking and locking, so it is not necessary to hold the card in place while rotating the lock body; the card being removable by pulling it out of the slot. However, there is sometimes a requirement that the card should not be removed when the locking mechanism is unlocked as it is not to be left in an unlocked mode. Means to adjust the slot position, return it to a selected null position when the card is removed and lock-in the inserted card when the lock is unlocked are disclosed in the parent case to which this application is a Continuation-in-Part.
[0006] If a standard type card containing an aperture to receive a lock-in pin is inserted into the slot of the card lock-in mechanisms described in the parent case and the user slightly releases pressure on it while rotating the housing, the card lock-in pin in the lock will jam against the card in a location other than the location of the pin aperture. This could make an unwanted depression in the card which could prevent the card from being easily withdrawn from the slot and further pressure could damage the card or the mechanism.
[0007] Also when the card is retained in the housing of such a lock, it is desirable to be able to release finger pressure on the inserted card when the housing is first rotated.
OBJECT OF THE INVENTION
[0008] It is the object of the present invention to provide a magnetically coded card that overcomes or substantially ameliorates one or more of the above disadvantages.
DISCLOSURE OF THE INVENTION
[0009] According to one aspect of the invention there is provided a magnetically coded card for use with the disclosed locks and comprising at least one dimple projecting therefrom and engaging with the slot upon insertion therein and providing resistance against removal from the slot.
[0010] The magnetically coded card typically comprises an aperture through which a card-impaling lock-in pin of the lock can pass when the card is fully inserted within the slot.
[0011] According to another aspect of the invention, there is provided a magnetically coded card for use with a lock having a slot into which the card is inserted to operate the lock, comprising an aperture for impaling by a card lock-in pin of the lock when the lock housing is subsequently rotated.
[0012] The lock would comprise means to hold the card fully inserted prior to rotation of the housing.
[0013] The magnetically coded card might further comprise at least one-dimple projecting therefrom and engaging with the slot upon insertion therein and providing resistance against removal of the card from the slot.
[0014] There is further disclosed herein a magnetically coded card for use with a lock having a slot into which the card is inserted to operate the lock, and an aperture through which a card-impaling lock-in pin or actuator pin of the lock can pass when the card is fully inserted within the slot, the card comprising a magnetic insert between a hard magnetic sheet and a soft non-magnetic sheet, the hard magnetic sheet having a large opening at the card aperture, and the non-magnetic sheet having a smaller opening flared into the card aperture.
[0015] Preferably, the hard magnetic sheet is made of metal.
[0016] There is further disclosed herein a combination comprising, a lock and a magnetically coded card, the lock comprising a slot into which the card is inserted to operate the lock, and a latching button extending into the slot, the card comprising an aperture for impaling by the latching button when the card is fully inserted within the slot, the aperture having openings of different dimension at each side of the card.
[0017] Preferably, the button has a bevelled upper surface to allow the card to pass by the button when force is applied to the card.
[0018] Preferably, the button is made of hardened steel.
[0019] Preferably, the lock further comprises a spring base having a spring leaf extending therefrom and on which the latching button is located.
[0020] Preferably, the lock further comprises a magnetic shield plate, a non-magnetic cover plate, and a spring plate having a hole therethrough and through which the latching button extends, the spring plate biasing the magnetic shield plate into contact with the non-magnetic cover plate to keep the slot closed when there is no card in the slot.
[0021] There is further disclosed herein a combination comprising a lock and a magnetically coded card, the lock comprising a slot into which the card is inserted to operate the lock, and a latching button extending into the slot, the card comprising a magnetic insert between a hard magnetic sheet and a soft non-magnetic sheet, the card having an aperture therethrough, the hard magnetic sheet having a large opening at the aperture, and the non-magnetic sheet having a smaller opening flared into the aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Preferred locks with which the magnetically coded card can be used, and preferred forms of the card itself will now be described by way of example with reference to the accompanying drawings, wherein:
[0023] [0023]FIG. 1 is a schematic parts-exploded perspective illustration of a magnetic card-operated lock;
[0024] [0024]FIG. 2A is a schematic parts-exploded perspective illustration of parts of the locking mechanism showing the configuration of the weights to position the card slot sideways for a left-handed door;
[0025] [0025]FIG. 2B is a schematic parts-exploded perspective illustration of parts of the locking mechanism showing the configuration of the weights to position the card slot sideways for a right-handed door;
[0026] [0026]FIG. 2C is a schematic parts-exploded perspective illustration of parts of the locking mechanism showing the configuration of the weights to position the card slot upward for a right-handed door;
[0027] [0027]FIG. 2D is a schematic parts-exploded perspective illustration of parts of the locking mechanism showing the configuration of the weights to position the card slot downward for a right-handed door;
[0028] [0028]FIG. 3 is a schematic cross-sectional view of a door handle incorporating a similar magnetic card-operated weighted card slot lock;
[0029] [0029]FIG. 4 is a schematic parts-exploded perspective illustration of one embodiment of a magnetic card-operated lock;
[0030] [0030]FIG. 5 is a schematic end elevational view of the tailpiece engagement parts of the lock of FIG. 4;
[0031] [0031]FIG. 6 is a schematic parts-exploded perspective illustration of means to hold-in the card using the same aperture in the card through which the lock-in pin passes;
[0032] [0032]FIG. 7 is a cross sectional side view of the assembled lock of FIG. 6 as the card is being inserted;
[0033] [0033]FIG. 8 is a similar view to FIG. 7 with the card fully inserted;
[0034] [0034]FIG. 9 is a cross section of a metal-clad card with hole for lock-in pin; and
[0035] [0035]FIG. 10 is a schematic perspective illustration of a spring base from which there extends a spring leaf and latch button forming part of the mechanism depicted in FIGS. 7 and 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Referring to the drawings, in FIG. 1 various components of the lock are shown which are not directly relevant to the present invention and so will not be specially mentioned in the description. More relevant, the lock has a cover 10 with a peripheral slot 11 for receiving a magnetic card 51 . The cover 10 and principal components of the lock, including a lock plate 12 and a magnet pin tumbler carrying lock core 13 , are mounted on a friction free bearing 14 to rotate, together with a securing plate 15 , about a common fixed central axis of the lock and a bearing bushing 29 . In order to operate the lock, a correctly magnetically coded card 51 is inserted in the slot 11 and then the cover 10 (and internal mechanism) is rotated through the arc, typically 90° or more, in a manner already well-known. At the same time, a card tailpiece actuator 20 is engaged and is also rotated. It functions in a manner to be described more fully below.
[0037] A null rotational position for the free-turning cover 10 is determined by two semi-circular weights 17 that are fixed by screws 18 to the securing plate 15 in holes 18 ′. In the FIGS. 1 and 2C the null position of the cover 10 is arranged so that the slot 11 is uppermost. However, the securing plate 15 is provided with four screw holes 19 ′ (FIG. 2) so as to be secured in any one of four rotational positions. Thus, the slot 11 can be set to come to rest due to the gravitational force on the weights either at the top as shown, or facing to the left (FIG. 2A), to the right (FIG. 2B) or downwards (FIG. 2D) according to the position of the weights relative to the lock housing 36 (FIG. 2). Thus, as pictured, four null positions for the slot 11 can be chosen. In each case the lock is operated in the same manner as before, that is by inserting a correctly coded magnetic card into the slot 11 to “unlock” the lock, and rotating the cover 10 from the null position. When the card is removed the weights return the slot to the null position. It will be appreciated that it is a simple matter to change the position of the weights at any time if a different null position is required.
[0038] The described lock can also include a card lock-in mechanism (FIG. 1), that includes a fixed body 16 , the lock actuator 20 and a tail piece driver 21 that operates a connected lock set (not shown) to extend and retract a latch and/or bolt so that a door can be opened or secured. The actuator 20 and the tailpiece driver 21 are mechanically coupled by a slot 22 in the rear face of the actuator that receives a flat finger 23 extending from the front face of the tailpiece driver 21 . Mechanical coupling between the slot 22 and the finger 23 is maintained effective even when the actuator moves a limited distance axially away from or towards the tailpiece driver. Both components 20 and 21 are contained within 1 through-hole 33 in the body 16 .
[0039] The actuator 20 has a peripheral spiral groove 24 into which a remote end of a fixed pin 25 in body 16 is located. The pin extends into the hole 33 to engage in the groove 24 . As a result, turning the cover 10 with a correctly coded card fully inserted and the tumbler carrying core 13 depressed, a driver pin 31 in the rear surface of core 13 engages a notch 37 in disc 30 which in turn rotates a flat portion 38 of the actuator 20 inserted into the axis slot of the disc 30 . This rotates the actuator 20 to move-axially through the body 16 towards the card slot 11 due to the fixed pin 25 in spiral groove 24 . A pointed finger 26 on the front of the actuator 20 enters and extends through a hole 50 provided in the inserted card 51 and thereafter prevents the card being pulled out of the slot 11 as the lock is unlocked. The card cannot be removed until the lock is again locked when the above action is reversed. That is, the card and slot is rotated in the opposite direction retracting the finger 26 from the centre hole 50 in the inserted card 51 . Then the actuator 20 is moved, by relative rotation of the groove 24 and the fixed pin 25 , towards the tailpiece driver 21 .
[0040] The slot 22 of tailpiece actuator 20 is axially movable over the flat finger 23 of the tailpiece driver 21 . The formed end of the tailpiece 32 is received within a slot 49 in the rear surface of the driver 21 . The tailpiece 32 can be provided with a number of transverse lines of weakness (not shown) enabling the tailpiece to be snapped into the required length by the lock installer to fit doors of various thickness. The tailpiece 32 rotates upon rotation of the driver 20 to thereby operate a lock (not shown) into which it extends.
[0041] There is a spring 34 and plunger 35 fitted within the body 16 that serves to prevent inadvertent rotational movement of the tailpiece 32 by the end of the plunger 35 pressing on a flat area of groove 39 around the circumference of tailpiece driver 21 . This feature prevents inadvertent locking or unlocking of the connected lock mechanism that might occur prematurely should the tailpiece 32 be allowed to rotate freely.
[0042] Should it be desirable to provide means to leave the lock in the unlocked mode, a coded unlocking card 52 is used. Such an unlocking card is formed with an open slot 53 , extending from a bottom edge of the card to and including the area of the central hole 50 in the card, to straddle the extended finger 26 . Such an unlocking card may be used to unlock the lock and then be removed in the unlocked position because the open slot 53 allows the card to be withdrawn from the slot 11 with the finger 26 extended, leaving the lock in the unlocked mode. The unlocking card must also be used for locking the lock if it has been left unlocked, because a normal card cannot be fully inserted in the slot 11 due to the extended finger 26 . In this case the cover 10 must first be rotated to the position of the card slot when the unlocking card was removed, then the unlocking card 52 can be inserted and the mechanism operated and the lock housing 36 rotated back to the locked mode where the finger 26 is retracted out of the slot 53 in the card. Then the unlocking card is removed.
[0043] The above described unlocking card as well as a second embodiment of the unlocking card is shown in the applicant's European Patent EP 0024242. A two-piece card 54 is inserted into the unlocked lock seriatim when the finger 26 is extended across card slot 11 then the two pieces are fitted together in the slot 11 . When both sides are joined around the finger 26 , the lock can be actuated and the housing 36 rotated back to the locked mode where the finger 26 is retracted from slot 11 and the card can be removed in one piece.
[0044] [0044]FIGS. 2A to 2 D illustrate how the cylinder code module 36 (comprising parts 10 , 11 etc) can be biased into a selected orientation by choice of attachment positions of the weighted securing plate 15 . Arrow A in each of the figures indicates the insertion direction of the magnetically coded card into the cylinder code module. That is, the card-insertion slot 11 can face upwardly, downwardly, left or right, or any angle in between. The two pre-tapped holes 40 in the cylinder code module cover 10 receive screws 19 by which the securing plate 15 is mounted thereto. The weights 17 attached to the securing plate 15 will bias the card-insertion slot 11 into the desired null-orientation by gravity. Four of such positions are depicted.
[0045] In FIG. 3, a lock similar to the lock of FIG. 2A-2D is mounted in a cylindrical lock door operating handle 27 having the rotatable cover 10 and slot 11 as before. The cover is oriented to a chosen position by weights in the manner described above. An important feature of the arrangement of FIG. 3 is a central lock spindle adapter 28 that can be provided to fit different lock spindle dimensions. This enables the same handle 27 to be used with different lock mechanisms or for such handles already installed on locks to be replaced with a magnetic card-operated lock/handle. It is particularly important that the slot 11 can be set to any desired rotational null positioning by selective positioning of the weights 17 . As a result, the lock can be provided with a keyed handle mounted on a left side or a right side of a door, and either inside or outside the door. In all positions the slot 11 , can be automatically positioned as desired due to the selective positioning of the securing plate 15 with weights 17 . If slot 11 is positioned either up or down no change is required for either left or right hand mounting as the slot remains in the desired position due to gravity when the handle points either right or left. For mounting with slot to either side, relocation of the securing plate with its attached weights is required. Such a handle lock can also contain a similar card Lock-in Mechanism as previously described.
[0046] In FIGS. 4 and 5 of the accompanying drawings there is depicted schematically an improved card-lock-in device. In this alternative embodiment, the tip end 56 of the card lock-in pin 45 enters the hole 50 in the inserted card 51 before the lock mechanism begins to unlock the attached lock. This is achieved by moving only the card lock-in pin through the hole in the card at the start of rotation of housing assembly 36 . The other components remain aligned in the body of the lock.
[0047] The card-lock-in pin 45 is L-shaped with its short rear end extending 90° radially. The longer part of the card lock-in pin 45 extends through actuator 47 that in turn is positioned for rotation in sleeve 48 . The tailpiece actuator 47 and sleeve 48 are fitted within the longitudinal hole 33 through body 16 . Rather than milling a spiral groove into the surface of the tailpiece actuator as in the embodiment of FIG. 1, there is a spiral slot cut through the wall of the sleeve 48 . The tailpiece actuator 47 extends through the sleeve 48 . The arc of the spiral slot in sleeve 48 only extends around half its circumference and this provides a more positive card lock-in pin movement. There is a spring 34 and plunger 35 that rides in the groove 39 of the tailpiece driver 43 as is the case with the embodiment of FIG. 1, serving to hold it in place and also to provide a detent flat surface to bias the tailpiece actuator to the “locked” position which is the starting point of rotation. There is a retention screw 42 passing radially through the body 16 to secure the sleeve 48 in place through hole 42 ′.
[0048] The tailpiece actuator 47 is slotted on one end with another slot on its side (not shown) to receive a spring 46 and the 90° bent over short end of card lock-in pin 45 . There is an axial hole through the tailpiece actuator into which the longitudinal part of card lock-in pin 45 extends such that its tip 56 may pass through the hole 50 in magnetic card 51 . As the card lock-in pin 45 moves forward such that its tip extends beyond the leading end of tailpiece actuator 38 , the 90° bent over end of card lock-in pin 45 compresses the spring 46 . That is, the spring urges the card lock-in pin 45 back to the starting position when the lock has returned to the locked mode.
[0049] The tailpiece driver 43 has an off-centre finger 44 extending from its front face. As shown in FIG. 5, the back end of the tailpiece actuator 47 has an hourglass shaped slot into which the finger 44 extends. The 90° bent end of the card lock-in pin 45 is also received in this slot. It should be noted that as a result of the configuration of FIG. 5, the tailpiece actuator 47 can rotate before contacting the finger 44 to begin rotation of the tailpiece driver 43 which unlocks the lock, this is termed “lazy cam” action. It allows the tip end 56 of the card lock-in pin 45 to enter hole 50 in card 51 to prevent its removal from card slot 11 as described in detail below.
[0050] The driver pin of the magnet-carrying core is normally positioned in the lower central area of the driver disc 30 . When a correct card is inserted into the code module it moves the magnet-carrying core 13 of the module downwards. The driver pin 31 in the rear of that core moves down into the open slot 37 of the driver disc 30 . Subsequent rotation of the code module 36 and core rotates the driver pin 31 which in turn rotates the driver disc 30 . The square hole in the disc receives the square portion 38 of the tailpiece actuator so it also is rotated. As the tailpiece actuator 47 carries the bent card lock-in pin 45 , the rotation causes the tip 55 of the pin to ride up the spiral slot in the sleeve 48 moving the pin forward into the card slot where it impales the card 51 through hole 50 , preventing its removal. A circlip 58 prevents disc 30 from moving axially into contact with the rear surface of the magnet pin-carrying core 13 , which could jam the mechanism. Reversing the rotation of the code module retracts the card lock-in pin 45 out of the hole 50 in the card and when fully retracted in the “locked” mode of the lock-in device, the card can be removed from the code module slot.
[0051] Although the card 51 is retained in the housing 36 as it is rotated, it is desirable to be able to release pressure on the inserted card when the housing is first rotated. To accomplish this the card 50 has stamped dimples 57 in its surface so that the initial pressure to insert the card will push the dimples fully into the slot 11 of cover 10 and hold the card in the fully inserted position as the housing is rotated. The dimples are pressed past the cover thickness at the card slot so they grip on the inside surface edge of the cover to offer resistance to the removal of the card.
[0052] [0052]FIGS. 6-9 show another method of holding in the inserted card without adding dimples to it.
[0053] In FIGS. 6-9 the card is of the same type as used with the dimples. It consists of an inner insert of a magnetic sheet material between two sheets of metal, the outer side being magnetic stainless steel and the inner side a non-magnetic material such as stainless steel, brass or aluminium. The use of the two different types of materials creates a card that can be encoded only on the non-magnetic side. The opposite side, being magnetic does not pass the magnetic fields of the internal encoded areas. It is a harder material than the opposing side. This non-magnetic side faces the magnetic pin tumblers in the lock. The harder side is usually stamped with an arrow to indicate which side is to be outwards when inserting the card in the slot. Such stamping must be made on the outside metal part before assembly of the card due to the hardness of the material. The non-magnetic side, being softer can be stamped with an individual serial number or other identification after manufacture. These features are important to the operation of the card lock-in mechanism to be described.
[0054] Although the card with dimples is quite practical, it takes more strength of the fingers to push the dimples past the card slot opening and if the same card is used in locks that do not have the card lock-in feature, the same strength is required to insert the card in those locks as well. Therefore an embodiment of a card that can be retained in the slot without the need for dimples is more acceptable in multi-lock systems.
[0055] [0055]FIG. 6 shows such a card and mechanism in partial exploded view. The card 59 has a through-hole 60 with different diameter openings 61 and 62 on either side of card 59 as shown in detail in FIG. 9. The hole 60 accepts the tip end 56 of lock-in pin 45 or pin 26 of actuator 20 when the card is fully inserted into the card slot 11 of lock cover 10 . The non-magnetic side 63 of the card 59 has the entry 61 flared into hole 60 in the card. The opposite side 64 of the card 59 is the harder material and has the larger diameter hole 62 in alignment with the smaller diameter flared hole 61 on the side 63 for a purpose to be described.
[0056] A spring base 67 with extended spring leaf 65 is located in the inside bottom of cover 10 . This part is shown separately in FIG. 10. At the tip end of spring leaf 65 is affixed a hardened steel latching button 66 . The button 66 extends through the hole 69 in the spring plate 68 . The spring plate biases the magnetic steel shield plate 70 into contact with the non-magnetic cover plate 71 to keep the slot 11 closed when there is no inserted card. Plate 70 also serves to attract all the locking pin tumblers 78 in the core 13 into their respective locking holes 79 of the locking plate 12 thus keeping the lock locked when there is no card in the card slot.
[0057] The latching button 66 also passes through hole 75 in shield plate 70 into the card slot area and when there is no inserted card in the card slot 11 , it also enters hole 76 in cover plate 71 and into hole 77 in lock plate 12 . However when card 59 is being inserted into the card slot 11 it pushes back the latching button 66 to the surface of shield plate 70 and when fully inserted in the card slot 11 the latching button 66 passes through the hole 60 in card 59 to retain the card in the fully inserted position in the card slot 11 .
[0058] [0058]FIG. 7 is a cross section side view of the assembled code module showing a card 59 partially inserted with its bottom end touching the latching button 66 . Note that the upper surface of the button is bevelled to allow the card to pass by the button when slight added force is applied to the card.
[0059] [0059]FIG. 8 is a similar cross section with the card 59 fully inserted and the internal magnet-carrying core 13 pushed down to its fully depressed position to unlock the lock. In so doing the coil spring 72 in plunger 73 , used to return the core 13 to locked position, has been fully compressed into the hole 74 in the bottom of the core 13 . To retain the card 59 fully inserted in the lock after the inserting force is removed requires a force greater than that of the compressed spring 72 which is biasing the core 13 back to the locked position. This larger force is supplied by the entry of the latching button 66 into the larger diameter hole 62 in the side 64 of the card 59 when the card is fully inserted into the lock. The contour of the bottom surface of the button 66 is formed to bear on the bottom edge of the hole 62 without allowing the hole to slip off the button, yet allow this slipping to occur when the card is withdrawn from the slot. As the repeated insertion of cards would cause unwanted wear on the button 66 and the hole 62 , both are preferably made of sufficiently hard metal to withstand these actions without appreciable wear. Due to the required size of the latching button 66 the hole 62 is larger in diameter than the hole 61 on the opposite side 63 of the card 59 .
[0060] The hole 61 has been flared in after assembly of the card to accept the tip 56 of the locking pin 45 or the pin 26 of the actuator 20 . As those pins are a smaller diameter than the base of the latching button 66 , a smaller hole 61 can be used. However the tip of the button 66 is sized to enter the smaller diameter hole 61 so it can extend completely through the hole 60 in the card 59 .
[0061] The locking pin tips 56 or 26 could push the latching button 66 out of the hole 60 in card 59 . If it does so the card 59 is still retained in the card slot 11 . Ideally the pin tips should not push the button 66 completely out of the card hole 60 . Partial insertion of the pin tips 56 or 26 into the card hole 60 is sufficient to retain the card in the slot. When the pin tips 56 or 26 are retracted from the card hole 60 the latching button 66 follows to continue to hold the card 59 in the fully inserted position until it is withdrawn from the card slot.
[0062] Thus has been described various types of cards with aperture for entry of a locking pin to retain the card in the card slot when the lock mechanism has been unlocked by rotation of the cover 10 . Also an improved mechanism to hold-in a card prior to and after said rotation of the cover has extended and then retracted a locking pin through the card aperture.
[0063] It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. | A magnetically coded card for use with a lock having a slot into which the card is inserted to operate the lock has an aperture through which a card-impaling lock-in pin of the lock can pass when the card is fully inserted within the slot, thus retaining the card in the slot when the lock is unlocked and releasing the card when the lock is again locked. The card can include at least one dimple projecting therefrom and engaging with the slot upon insertion therein and providing resistance against removal of the card from the slot. | 4 |
BACKGROUND
[0001] The reliability and performance of Nitride-based high electron mobility transistor (HEMT) semiconductors are very sensitive to damage at the surface of the semiconductor. The fabrication process can cause damage to an exposed surface by creating point defects, oxide layers, and contamination.
SUMMARY
[0002] The invention in one implementation encompasses an improved method for fabricating an HEMT device having active device layers deposited on a semiconductor substrate. In an embodiment, the improved method comprises the steps of depositing an AlN layer over the active device layers using a relatively low temperature vacuum process to form an amorphous layer protecting the active device layers from unnecessary exposure to fabrication processes, and selectively forming openings in the AlN layer to expose portions of the active device layers for imminent process steps.
[0003] The invention in another implementation encompasses an improved fabrication system for an HEMT device having active device layers deposited on a semiconductor substrate. In an embodiment, the improved fabrication system comprises means for depositing an AlN layer over the active device layers using a relatively low temperature vacuum process to form an amorphous layer protecting the active device layers from unnecessary exposure to fabrication processes, and means for selectively forming openings in the AlN layer to expose portions of the active device layers for imminent process steps.
DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 depicts a semiconductor device having an amorphous AlN cap.
[0005] FIG. 2 illustrates source and drain windows opened in the device of FIG. 1 .
[0006] FIG. 3 depicts source and drain contacts formed in the device of FIG. 2 .
[0007] FIG. 4 shows a gate window opened in the AlN cap of the device of FIG. 3 .
[0008] FIG. 5 illustrates gate formation by deposition of gate metal in the device of FIG. 4 .
[0009] FIG. 6 depicts the device of FIG. 5 with the remaining AlN layer removed.
[0010] FIG. 7 shows the surface of the completed device passivated with SiN.
[0011] FIG. 8 is a flow chart of a semiconductor fabrication process.
DETAILED DESCRIPTION
[0012] During device manufacture, unprotected surfaces can be affected by exposure to the fabrication environment. Air exposure leads to the formation of thin oxide layers on the surface of the semiconductor. Vacancies and other point defects are created during the high temperature anneal used to create ohmic contacts, as well as plasma cleaning treatments. Finally, diffusion of contaminants into the semiconductor can occur due to residues left on the surface during processing. Oxide layers, point defects, and contamination have been found to cause electron trapping at the surface that degrades performance and reliability.
[0013] A protective layer that can be selectively removed during the fabrication process can shield the surface from damage due to oxidation, high-temperature processing steps, plasma cleans, and contamination.
[0014] Low temperature AlN (aluminum nitride) deposited in situ under vacuum as part of the growth process protects the semiconductor surface from exposure to the fabrication environment. Due to the large difference in crystal structure between the AlN and the semiconductor, openings in the AlN layer can be selectively etched (wet or dry etching) to expose the semiconductor surface in the area that is immediately to undergo a processing step. For example, in an embodiment, immediately before depositing gate metal, an opening in the AlN is etched so that the gate metal is deposited on the barrier surface. This effectively eliminates any surface exposure of the area under the gate prior to this gate metallization step.
[0015] AlN is grown at low temperature in the deposition system under vacuum. The layer is designed to be polycrystalline/amorphous to avoid cracking. During the fabrication process, windows within the AlN are opened using wet or dry etching to expose the surface just before a processing step, only in the area required for the processing step (i.e., ohmic metal deposition, gate metal deposition, SiN deposition).
[0016] Using the process described herein, the semiconductor surface remains protected (covered with AlN) until just before metal deposition, SiN passivation, and during all high-temperature anneals. The surface is capped with AlN before exposure to air. The AlN can be easily removed before processing steps due to its selectivity during etching. In addition, the AlN can be grown thick without cracking.
[0017] FIG. 1 depicts a semiconductor device 101 having an amorphous AlN cap 102 . In an embodiment, the AlN layer is deposited using molecular beam epitaxy, or MBE. MBE is used to deposit the AlN cap 102 rather than chemical vapor deposition (CVD) or physical vapor deposition (PVD). MBE, CVD, and PVD are very different in how they deposit a material on a substrate. In the MBE technique, highly purified atomic species are created in source cells far from the substrate. During deposition, these atomic species are allowed to move through the vacuum and impinge on the substrate, creating a thin film. Due to the high reactivity of the atomic species, very little energy (heating) is required at the substrate to create the reacted film. Therefore, the deposition of the AlN can be carried out over a wide range of substrate temperatures that can change the crystal structure of the AlN from amorphous (low temperature) to highly crystalline (high temperature). This ability to tune the crystalline nature of the AlN is unique to MBE and is advantageous because it allows one to change the stress within the film, and to change the selectivity of the AlN etch process. CVD-generated layers have to be deposited at higher temperatures in order to create the reactive species. PVD-generated layers are deposited at lower temperatures, and utilize damaging plasmas near the substrate that can cause point defects in the semiconductor. In addition, to deposit PVD- or CVD-generated AlN films on nitride semiconductors grown by MBE, the substrate would have to be exposed to the air environment before the AlN deposition, allowing for the formation of an oxide layer. By depositing the AlN film in situ by MBE, the semiconductor surface is not exposed to air, and is protected from oxide formation.
[0018] Windows are then opened through the AlN cap for source and drain contacts, as shown in FIG. 2 , in which a source window 103 and drain window 104 are illustrated. Source and drain contacts 105 , 106 are then fabricated, as depicted in FIG. 3 . Next, a gate window 107 is opened in the AlN cap 102 as shown in FIG. 4 .
[0019] FIG. 5 illustrates the formation of a gate 108 by deposition of gate metal. The remaining AlN layer 102 is then removed as illustrated in FIG. 6 . FIG. 7 shows that the surface of the completed device is then passivated with SiN (silicon nitride) 110 .
[0020] As shown in FIG. 8 , a semiconductor fabrication process for a HEMT device begins by depositing active semiconductor layers and an AlN cap layer in step 801 . In the subsequent step ( 802 ) windows are opened through the AlN, using a mild etchant, for source and drain contacts. Source and drain contacts are then formed in step 803 .
[0021] In the next step ( 804 ), a window is opened through the AlN for the gate, and gate metal is then deposited (in step 805 ) to create the gate for the device. In the subsequent step ( 806 ), the remaining AlN is removed. In step 807 , the surface of the device is passivated with SiN.
[0022] The steps or operations described herein are intended as examples. There may be many variations to these steps or operations without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted, or modified.
[0023] Although examples of implementations of the invention have been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions, and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims. For example, the AlN layer described herein could be deposited by MBE on semiconductor films that are deposited using other epitaxial techniques, such as MOCVD or HVPE.
[0024] MOCVD, or metalorganic chemical vapor deposition, is a form of chemical vapor deposition used for epitaxial growth. In MOCVD, compound semiconductors are grown on a substrate, in a reactor, by introducing an organic compound in combination with a metal hydride. An epitaxial layer is formed by final pyrolysis at the substrate surface. This differs from MBE in that the epitaxy is deposited by a chemical reaction and not physical deposition. Instead of vacuum, the reactor environment moderate pressure. HVPE, or hydride vapor phase epitaxy (HVPE), is a similar process utilizing carrier gasses that may include Ammonia, Hydrogen, and various Chlorides. In the case where the semiconductor films are deposited using one of the above-described techniques, the surface would be exposed to the air environment before being placed into the MBE vacuum chamber for deposition of the AlN layer. | An improved method for fabricating an HEMT device having active device layers deposited on a semiconductor substrate. In an embodiment, the improved method comprises the steps of depositing an AlN layer over the active device layers using a relatively low temperature vacuum process to form an amorphous layer protecting the active device layers from unnecessary exposure to fabrication processes, and selectively forming openings in the AlN layer to expose portions of the active device layers for imminent process steps. | 7 |
[0001] This application claims the benefit of commonly owned and copending U.S. Provisional Application Serial No. No. 60/325,923, filed Sep. 28, 2001. The invention disclosed in this application is related to Disclosure Document No. 497692 filed on Jul. 30, 2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to gaming machines.
[0004] 2. Description of Related Art
[0005] In a standard bonus-game gaming machine, animation is utilized on a video screen or other display device to award monetary prizes in an entertaining fashion. The players interaction with the animated bonus event is limited to choosing symbols, characters etc. to reveal bonus credit amounts. The primary game animation or bonus animation may display intricate bonus events to the player and then award the player with the bonus prize. In addition the player may make a choice in the primary or bonus game that causes an animated or recorded real-life video loop to be played which will entertain and award the player with a prize. Alternately, the player may be presented by a randomly chosen and displayed number of characters, symbols or images which will reveal bonus amounts when chosen by the player said quantity of images displayed and corresponding bonus amounts randomly changing each time the player reaches the bonus round.
[0006] One particular interactive scenario used with gaming machines is IGT's “Little Green Men”. In the bonus event, the player is instructed to choose one of five characters sitting in front of a small farm house. Once the player has chosen a character, an alien space ship beams up the character and flies away. A few seconds later a newspaper spins toward the screen and stops once it grows large enough to cover the monitor. The newspaper displays the character that the player chose with a “Reward” amount displayed under the character's picture. The “Reward” amount equals the bonus credits won by the player. The player's choice in this game causes the game to display five different newspapers with different “Reward” amounts. The key premise or story-line in IGT's Little Green Men and similar other games does not change.
SUMMARY OF THE INVENTION
[0007] The present invention offers far greater entertainment value to players than current gaming machines because the player has the opportunity to interact with characters in a base or preferably a bonus game and through this interaction, alter or advance the story-line of the game. The ability to alter the story-line of the bonus game ensures that the players level of entertainment stays very high even if they have played the same game many times over.
[0008] In the preferred embodiment of the invention, the player will advance to an interactive bonus game after achieving a certain combination of symbols on a base game. Once the player has advanced to the bonus game they will have the opportunity to play a video based animated or real-life bonus game that varies depending on the players input. The player's input in the preferred embodiment will be via the base game display, which will be a touch screen LCD or video monitor and which has the dual purpose of displaying the base game during base game play and being the player interface during the bonus play which will be displayed on an LCD or video monitor in the top-box of the gaming device. The players input in the preferred embodiment will include but not be limited to answering questions posed by the characters in the game, making decisions for the characters in the game or assisting the characters in the game whether such assistance is in the form of shooting targets, picking up objects, choosing paths, steering vehicles or basically interacting with the primary characters of the storyline.
[0009] In an alternative embodiment the gaming machine based on the present invention has standard stepper motor driven reels for the base game, an LCD or video monitor to display the bonus game and buttons, joystick, track-ball or other mechanical input device for the player to interface with the bonus game.
[0010] In the preferred embodiment the gaming machine has ample storage in the form of hard-disk, DVD-ROM, or CD-ROM on which the bonus game scenes are stored and sufficient random access memory to allow for the seamless integration and display of the scenes that correspond the player interactivity.
[0011] In the preferred embodiment there will be many different variations of story-line, action within the story-line and monetary awards awarded within the story-line. The number of different story-line variations, monetary awards and action within the story-line can be in the thousands, tens of thousands or millions depending on the desire of the game designers.
[0012] In the preferred embodiment the processor will award monetary prizes for all story-line segments prior to play of the interactive story-line bonus game. In this embodiment a player that fails to kill a dragon allowing the dragon to fly away with the princess will be awarded a monetary award that was chosen randomly by the processor prior to the play of the bonus game. If the player had killed the dragon and saved the princess then the monetary award associated with this success would also have been chosen by the game processor prior to the play of the bonus game.
[0013] In the preferred embodiment the story-line advancement is a mixture of player interaction, randomly chosen scenes and preset scenes. The result of the mixture is that the player's successful interaction can be awarded with monetary awards if the game is skill based but if a skill based game is not desired the player can still interact for entertainment value but the game processor can randomly choose scenes that correspond to the player's interaction. In the latter case the player's skill or lack thereof has no affect on the monetary award received in the bonus game. For example if the game desire wanted the player involved in the slaying of the dragon but did not want the player's skill involved then the game characters would ask the player “Slay the dragon?” or “don't slay the dragon?”. If the player chose “slay the dragon” then the hero in the story-line would slay the dragon, the princess would be saved and a monetary award would be awarded to the player.
[0014] The primary object of the present invention is to provide a gaming machine that allows players to play an intricate bonus game where they can interact with characters in many different ways, win randomly assigned, skill based or pre-assigned monetary awards and through their interaction and alter the story-line of the bonus game.
[0015] Another object of the present invention is to provide a gaming machine where the player has the perception that their skill in the bonus game has advanced the game to a monetary award though even without skill or interaction on the player's part the monetary award would still have been received.
[0016] Yet another object of the present invention is to provide a gaming machine bonus game where the player makes a few key choices in the beginning of the bonus game thereby changing the overall story-line but not requiring constant interaction with the characters in the bonus game. In this embodiment the player slightly changes the story-line but they do not have to do much but sit back and watch the story-line play out per their initial decisions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a diagram illustrating a preferred embodiment of the gaming device of the present invention.
[0018] [0018]FIG. 2 is a flow chart illustrating how a player can win monetary awards during a interactive story-line bonus game in accordance with the present invention.
[0019] [0019]FIG. 3 is a block diagram of the basic electronic configuration of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In the interactive story-line gaming machine of the present invention, the player interacts with the animated or real life character or characters. The interaction with the animated or recorded real-life character can be led by the character and or the player. When the player interacts with the character, the story-line of the primary or bonus game changes as a result of the interaction and the monetary amount awarded to the player changes as a direct result of the players interactive choices or decisions.
[0021] For example, a character may greet the player and ask the player a series of questions the answers to which are communicated by the player to the game via a button, voice recognition, touch screen input, mouse pad, mouse ball, joy-stick, sword, pistol or any other form of player input commonly known and associated with player interactive games. The player's answers to the character's questions or the players decisions will cause the story-line of the game to change. For example, a player's answer of “yes” to whether or not they like sports and an answer of “no” to whether or not they like dessert may cause the bonus game to display a sporting event where animated or real-life baseball player tries to hit a home run with their success equaling the bonus payment to the player. If the player had answered “yes” to both questions, then the bonus game may have displayed animated or real characters playing a bowling game where the pins are characters and the bowler throws a pie at the pins in an effort to get a strike. Regardless of the players answer the gaming machine will award the player with a predefined or randomly chosen monetary award which will be awarded prior to, during or following the animated or real-life segment that is controlled by the processor and displayed to the player via the display device.
[0022] The purpose of the interactive story-line is to create an environment where the player has greater entertainment value because he or she is actively involved in the story-line of the game. The player gets to script or direct the story-line through the interaction with the characters. If the storyline is about police chasing the bad guys then the player gets to join in the chase as one of the policemen and the players decisions, answers to questions and actions change the storyline of the chase. One important benefit is that casino machines that incorporate this invention will be able to offer players many different versions of the primary and bonus games thereby ensuring that the player does not get bored.
[0023] The ensuing example illustrates one embodiment of the present invention. However, it is to be understood that this is just one example and that other more interactive examples and embodiments are possible.
EXAMPLE I
[0024] The ensuing example pertains to the use of the well-known character Betty Boop™ as one of the interactive characters in the gaming machine though any well known or new character could be used.
Scene 1: Opening Scene
[0025] Opening Scene: Betty is sitting in a traditional movie star style dressing room getting ready for the day. She greets the player and continues picking up one script and throwing it down, picking up another and throwing it down”.
[0026] Betty Boop: “Oohh this is too difficult. I have three great roles offered by the studio and I can't decide which one to take.”
[0027] Action: Betty looks into the mirror and notices that the player has walked into the room.
[0028] Betty Boop: “I am so happy you're here. I really need a good agent to help me with my career.”
[0029] Action: Betty spins around in her chair and looks at the player head on.
[0030] Betty Boop: “Please be my agent and pick the best movie to star in and I will pay you a bonus for your choice.”
[0031] Scene 2: Three Movie Posters—The player picks the movie.
[0032] Poster #1: “Betty in Circus Extravaganza”
[0033] Poster #2: “Betty in Cook-n-Cookies”
[0034] Poster #3: “Betty in Game Show Babe”
[0035] Action: The poster choice fades and reveals a small “signing” bonus amount.
[0036] Scene 3: Betty Boop back in her dressing room.
[0037] Action: Betty is still sitting in her dressing chair.
[0038] Betty Boop: “I love your choice, it will make me a bigger star than ever”
[0039] Betty Boop: “Now I have another offer for you. Why don't you be my director? The studio will pay you well.”
[0040] Action: Betty gets up out of her chair and walking out of the room glances back at the player.
[0041] Betty Boop: “See you on the set”
[0042] Action: Betty closes the door behind her.
[0043] Betty in Circus Extravaganza
[0044] Scene 4: Betty Enters the Circus
[0045] Action: Betty walks down on of the hallways to the center of the circus.
[0046] Circus Announcer—The Clown: “Ladies and gentleman the incredible, the great, the fearless, the woman you all have been waiting for . . . . Betty Boop”.
[0047] Action: Betty bows to the crowd and waives her hand in the air.
[0048] Betty Boop: “Thank you, thank you, thank you”
[0049] Circus Announcer—The Clown: “Now ladies and gentleman, I would like to ask you to choose the act that Betty will perform.
[0050] Action: The player decides whether Betty will be:
a) Riding the Elephants b) Taming the “nasty” tigers″ c) Swinging on the Trapeze d) Cannon Fodder
[0051] Betty Boop: Statements by Betty vary depending on the player's choice of the act.
[0052] Bonus Payouts: The manner in which Betty completes the act affect the bonus amounts won.
[0053] Scene 5—Taming the “nasty” Tigers:
[0054] Action: Betty keeps the tigers at bay with the whip and the chair.
[0055] Betty Boop: “Stay away you big, nasty beasts”
[0056] Action: As the tigers roar and swipe at Betty and she counters with the whip and chair, the player accumulates bonus points.
[0057] Scene 6—Cannon Fodder:
[0058] Action: Betty puts on her helmet and climbs up the ladder, climbs into the end of the cannon and waives to the crowd.
[0059] Action: The announcer walks up the cannon, lights the fuse and shoots Betty through the air.
[0060] Betty Boop: “Weeeeeeeeeeee”
[0061] Action: Betty lands on her feet, takes off the helmet and bows to the crowd.
[0062] Betty Boop: “Thank you, thank you, thank you”
[0063] Bonus Win: The bonus amount won depends on how far Betty flew out of the cannon.
[0064] Scene 7—Swinging on the Trapeze:
[0065] Premise: Betty's will ask the player to choose which trapeze to swing from and which flips and tricks to perform. The player's choices will alter the outcome of this scene allowing the player to win different bonus amounts depending on the final outcome.
[0066] Scene 8—Riding the Elephants:
[0067] Premise: Betty rides around the ring on the back of an elephant grabbing rings from circus members. Once Betty has the rings in her hands she will ask the player questions such as but not limited to how many she should juggle and should she balance on one foot while juggling. The player's choices will alter the outcome of this scene allowing the player to win different bonus amounts depending on the final outcome.
[0068] Betty in Cook-n-Cookies
[0069] Scene 9—The scene is Betty's kitchen. The kitchen door opens and Betty enters singing a tune.
[0070] Betty Boop: “I want to cook some cookies for my friends.
[0071] Action: Betty continues singing while she starts to roll the cookie dough.
[0072] Betty Boop: “Where is my cookie sheet?”
[0073] Action: Betty turns around to grab the cookie sheet from one of the lower cupboards. While turned around, Betty accidentally bumps into the table and knocks it over.
[0074] Action: The cookie dough, rolling pin and bag of flour go flying.
[0075] Action: Betty swings back around, catches her foot on the end of the table and falls down with her face going straight into the pile of flour.
[0076] Action: The flour goes flying up in a cloud and blankets Betty, covering her hair and face.
[0077] Action: Betty stands up and tries in vain to brush the flour off of herself.
[0078] Action: Pudgy the dog starts laughing.
[0079] Action: The little boy starts laughing.
[0080] Betty Boop: “You two be quiet. This isn't funny”
[0081] Action: The chair at the far end of the room morphs into a human character and starts laughing.
[0082] Betty Boop: “Everyone stop laughing or there will be no cookies for anyone”.
[0083] Action: Betty stamps her feet and pulls at her hair.
[0084] Action: The clock at the far end of the room morphs into a humanistic character and joins in the laughter.
[0085] Betty Boop: “Ooohh, I am getting so mad”
[0086] Action: Betty picks up the cookie dough and breaks off a piece.
[0087] Action: The screen tells the player to choose one of the four laughing characters.
[0088] Betty Boop: “You want a cookie, I will give you a cookie”
[0089] Action: Betty throws the cookie dough at the target. Sometimes hitting the target, sometimes missing the target causing her to throw again.
[0090] Action: Once the character is hit with the cookie dough, they continue to laugh and then they throw it back at Betty. A food fights ensues and Betty, while laughing, starts to through the dough back at the characters. Every throw by Betty and the other characters starts racking up bonus points as all characters are laughing and having a great time.
[0091] Action: The characters finally tire out and start to eat the cookie dough.
[0092] Betty in the Game Show Babe
[0093] Scene 10—A game show set with a large wall of 10-12 squares that can be spun around to reveal an image on their backside.
[0094] Action: Betty Boop walks out onto the floor in a game show host outfit and greets the crowd.
[0095] Betty Boop: “Hello everyone and welcome to the best game show in the world” “Today we have one luck contestant that can win a lot of money if they match the images on the big board.
[0096] Action: Betty walks over to the big boards.
[0097] Betty Boop: “If you can match three of the images on the rear of the squares, you will be a winner. The more matches you have the more you will win.”
[0098] Action: The player starts to touch the squares causing them to spin around and reveal images of Betty, Pudgy, the clown, the boy, Gramps, etc.
[0099] Betty Boop: Every spin of the square causes Betty of the characters in the symbols to say something funny.
[0100] Action: The images on the squares morph into animated characters and start to say things to Betty.
[0101] Action: The player continues to spin squares until they hit a stop square.
[0102] Bonus Amounts: Bonuses depend on the images matched. Certain images are worth more than others as depicted on a bonus win paytable.
[0103] Scene 11: Closing Scene:
[0104] Scene: Betty is back in the dressing room.
[0105] Action: Betty spins around in the chair and faces the player.
[0106] Betty Boop: “Thank you so much being my agent and director”. “I had a great time working with you and hope that we can work together on another film project sometime soon.”
[0107] The ensuing example illustrates yet another embodiment of the present invention. This example is more interactive than the first example, however, it is to be understood that this is just another example and that other more increasingly interactive examples and embodiments are possible.
EXAMPLE II The ensuing example pertains to a new character “Joe Jackpot™” that could be used as the central character in an interactive gaming machine.
[0108] Scene: Joe Jackpot is sitting in the drivers seat of a Ferrari sports-car. The Ferrari is idling in the middle of a freeway that branches like a “Y” to the right and left. The player who has reached the bonus round by lining up three Joe Jackpot symbols in the base game has been transported into the game so that they are now sitting in the passenger seat looking at Joe Jackpot from a first person perspective.
[0109] Action: Joe Jackpot looks at the player.
[0110] Joe Jackpot: “Hey ya big winner, we need to get to Casino Island quicker than a buzzard to road kill”. Joe points out the front window to the left and to the right and asks the player, “You choose our path, the road to the left leads to the bridge and the road on the right leads to the ferry?”.
[0111] Action: The player uses a physical button on the machine, the touch screen or a voice command to choose the road to the right that leads to the ferry.
[0112] Joe Jackpot: “I guess you don't get seasick . . . lets boogie”
[0113] Action: Joe Jackpot floors the Ferrari which burns rubber for a few seconds and then rockets towards and down the road to the right. The Ferrari flies down the hilly road for a few seconds and when it comes over the top of the third hill, the player can see a brightly lit ferry tied at the dock. Joe expertly pulls the Ferrari up the ramp and onto the ferry.
[0114] Joe Jackpot: “You still awake big winner?”
[0115] Action: The player is prompted to respond with a yes or no and the player used a button, the touch screen or a voice command to respond with a yes.
[0116] Joe Jackpot: “I'm mighty glad for your sake. If you had been asleep I would have pushed you out of the car and backed up off of the ferry but since you are awake, you can tell me if we should stay in the car for the short trip or go upstairs to get some chow?”
[0117] Action: The player chooses “Upstairs for Chow” instead of “sitting in the car”.
[0118] The preceding example reflects the possible beginning of an interactive bonus event in an interactive story line gaming machine although it could also be used as the beginning of a base game in an interactive story line gaming machine.
[0119] In this example, we see that the player is making decisions for a game character, in this case Joe Jackpot. Thus, the game character and story line is altered by the player's decisions. If the player had chosen the road to the left which was the bridge to Casino Island, then perhaps the player and Joe Jackpot would have run into traffic or the drawbridge could have been up to allow a cruise ship to pass. The player in this example of course chose the road to the right which led to the ferry to Casino Island. When Joe Jackpot asked the player whether or not they were asleep, the player could have answered “yes” instead of the “no” used in this example. A “yes” answer could have resulted in the bonus event ending with the player winning a smaller “participant” award or it could have resulted in Joe Jackpot turning up the stereo of the car to awaken the player. The player in this example of course answered “no” and then “upstairs for chow” instead of “sitting in the car”. “Upstairs for chow” may result in no more questions from Joe Jackpot or interaction from the player until they reach the food section of the ferry or perhaps Joe Jackpot will ask the player whether or not “they want some fresh air before they eat?”.
[0120] As seen in both examples, the interactive story-line can be very short and basic with only a few possible endings to the story as a result of the player's interaction or the interactive story-line can be much more intricate and involved resulting not only in longer base or bonus game playing time but also many different possible endings or variations to the story. The players level of involvement could also be far greater including but not limited to the player driving the Ferrari in the second example or shooting a gun from the passenger seat of the Ferrari if Joe Jackpot were a policeman and the player and Joe were chasing bad guys. Monetary bonus awards in both examples can be awarded immediately after the player has made a decision or during a particular segment of the interactive storyline game. If the player was driving the Ferrari and steering via a steering wheel mounted on the gaming machine they could drive over “cash bags” lying on the road and score bonus amounts every time they successfully drove over a bag.
[0121] In a preferred embodiment of the invention, the existing standard gaming machine hardware is used for an interactive story-line game and modifications are made only to the software programming. In this embodiment the standard gaming machine includes a video screen to play a video slot game and a second video screen to display the interactive story-line bonus. The software of the interactive story-line game will establish branches in the display of the story-line of the base or bonus game. The player's input causes the software to retrieve from a standard storage medium animated or recorded real-life video segments that correspond to the players input. In this embodiment the software may choose segments that directly respond to the player's input or the software may randomly choose from a series of segments that could correspond to the player's input. The number of branches in the story-line or segments that could be displayed is limited only by the intended average length of the base game or bonus game.
[0122] Hardware and software that may be used to implement the present invention are disclosed in U.S. Pat. Nos. 5,611,694, 5,873,057, 5,737,527, 5,161,034, 5,848,934, 4,445,187, 4,333,152, 4,569,026, and 4,305,131, the disclosures of which are herein incorporated by reference.
[0123] Referring to FIG. 1, there is shown one possible configuration of the invention gaming device 10 which is a standard video gaming machine with a video screen 12 in the top-box 13 which is used to display the present invention. It should be noted that this configuration is only one embodiment as the gaming device cabinet can be in any of the forms commonly known in the industry including but not limited to slant-top, upright, in-bar or sit-on bar style.
[0124] The base game of gaming device 10 is played in the video screen 11 and could be any base game including but not limited to video reel, poker, blackjack or keno as well as being a mechanical reel slot machine in which case stepper reels would take the place of video screen 11 in gaming device 10 . The base game may also be linked to a wide area progressive, local area progressive or any other type of bonus game.
[0125] Gaming device 10 can include the standard array of player input devices including but not limited to a handle 14 , coin-out button 16 , bet max button 17 , spin button 18 and for the present invention, a “yes” button 19 and a “no” button 20 in addition to a coin-in head 21 .
[0126] Gaming device 10 also includes belly glass 15 to display the game name. This belly glass could be replaced with an LCD screen or other display device in an alternative embodiment of the present invention.
[0127] [0127]FIG. 2 illustrates a general diagram of the electronic design of the present invention which includes RAM memory 20 and ROM memory 21 which are used to store game data, player decisions or actions, the story-line content of the present invention and a processor 27 , touch screen 26 which can be configured as the player interface for the player to interact with the characters in the present invention and speakers 22 to project sounds of the base game and bonus game to the player, standard player interface 23 , such as buttons or other mechanical devices which are used when the touch screen 26 is not used and coin/bill acceptor 24 which the player uses to input money into the gaming device and the display devices 25 which as seen in FIG. 1, can include but not be limited to two video displays to display the base game and the bonus game of the present invention.
[0128] Referring to FIG. 3, there is shown the players' interaction with the story-line Example II above. In step 40 , the character asks the player to decide whether to take the bridge or ferry to get to an island. In step 41 , the player chooses the bridge. The alternative step is step 42 wherein the player chooses the ferry. In a preferred embodiment of the present invention, processor 27 randomly picks awards for different player decisions prior to the start of the interactive story-line bonus game. Thus, if the player chooses the bridge (step 41 ), the player wins 100 credits. As a result, the player's choice of the bridge leads to one of three randomly chosen scenes, indicated by steps 43 , 44 and 45 , from the database of possible story-line segments. Step 43 describes a randomly chosen scene wherein the Ferrari jumps the drawbridge so that the Ferrari reaches the island (step 50 ) and the player wins a total of 200 credits in step 60 . In step 44 , the Ferrari drives across the bridge and reaching the island (step 50 ) resulting in the player to win 175 credits in step 61 . In step 45 , the Ferrari is delayed by traffic on the bridge and therefore, does not reach the island. As a result, the player wins only 125 credits in step 62 .
[0129] If the player chooses the ferry (step 42 ) instead of the bridge (step 41 ), then there are three possible story-line segments, indicated by steps 46 , 47 , 48 , that are randomly chosen by processor 27 (see FIG. 2) with different randomly chosen award amounts. If the player reaches the island (step 50 ) because processor 27 randomly chooses the step 47 , then the player wins 275 coins in step 64 and the game will continue. If processor 27 chooses the other story-line segments, indicated by steps 46 and 48 , then the player does not reach the island, the game ends and the player wins the credit amounts in step 63 or step 65 .
[0130] It is important to note that this is a very basic example of the present invention as any number of segments in the story-line can be chosen as well as the level of player interactivity can be enhanced so that the player is constantly making decisions or inputting actions via the player interface. The story-line segments can be preset or randomly chosen by the processor and the monetary awards can be preset or randomly chosen. The level of randomness not only in the story-line but also the monetary awards is limited only by the desired length of play of a base or bonus game incorporating the present invention.
[0131] While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention. | A gaming machine with interactive story line. In a preferred embodiment of the invention, the player will advance to an interactive bonus game after achieving a certain combination of symbols on a base game. Once the player has advanced to the bonus game, he or she will have the opportunity to play a video based animated or real-life bonus game that varies depending on the player's input. In a preferred embodiment, the player's input is through the base game display, which is a touch screen LCD or video monitor and which has the dual purpose of displaying the base game during base game play and functioning as the player interface during the bonus play which is displayed on an LCD or video monitor in the top-box of the gaming device. The player's input in the preferred embodiment includes answering questions posed by the characters in the game, making decisions for the characters in the game or assisting the characters in the game whether such assistance is in the form of shooting targets, picking up objects, choosing paths, steering vehicles or basically interacting with the primary characters of the storyline. | 6 |
FIELD OF THE INVENTION
This invention relates to a universally adjustable, frameless backpack for backpackers that can also be used by energetic runners, bikers, skiers, and joggers, providing comfort to the wearer and adaptability to vigorous body motion.
BACKGROUND OF THE INVENTION
The sport of backpacking has achieved an amazing growth in popularity in recent years. This has, in turn, produced a great increase in production of backpacks for hikers. It has also stimulated the development of many improvements in designs of pack assemblies for carrying clothes, food, equipment, and water.
There are four basic types of packs including: a frame pack having a shoulder harness and a hip belt for larger capacities (i.e., 3000 cubic inches and up); a frameless pack, having a shoulder harness and hip belt; a day pack having a shoulder harness; and, for a minimum load, a hip belt pack. Frameless packs are used for medium capacity loads (i.e., 1500-3000 cubic inches) and are desirable because of their lighter weight (i.e., 2-3 pounds), as compared with the frame packs which typically are 4-6 pounds.
Many improved designs have been based on the recent discovery that the backpack should be allowed to swing, to a restricted degree, with each stride of the load-carrying person. The hiker can carry his pack for a longer period of time, with less fatigue and greater comfort, if the pack load on his back is supported by the lumbar region and movable, within limits, so that his body does not jerk the pack through a series of forceful oscillations corresponding to the walking or running rhythm. The flexibility of the pack reduces the pounding on the hiker's back.
On the other hand, it is important that the swinging movement be not only restricted but also adjustable to the peculiar characteristics of each hiker. Every person has a slightly different body build, muscle distribution, and stride characteristic. Even the same person may prefer changing the adjustment of his pack assembly from time to time, in order to switch the load slightly from one set of muscles to another. In previously known moveable backpacks, a crude combination of restricted movement and adjustability has been achieved by simply loosening the canvas straps by which it has been customary to tie the lower end of the pack to a padded waist belt encircling the waist of the load-carrying person. Such flexible straps permit the pack frame to swing in unpredictable manners, not adequately restricted for the needs of comfort of the wearer. Also, adjustability has proven unreliable, since a canvas strap may stretch, or loosen.
Many expert backpackers prefer a pack assembly which includes connections directly to the sides of the waist belt. A person carrying such a pack feels the load on the sides of his hips, rather than as something hanging down behind him. Unfortunately, such a pack frame mounting precludes the use of the swinging feature, also desirable to most expert backpackers. It is a feature desired by many expert backpackers that the pack load be mostly carried by the waist belt.
It is another desire of active packers, such as runners, that the body of the runner be allowed to freely pivot at the shoulders and the hips while the pack and gear remain in a relatively neutral, vertical position. This pivoting motion occurs with runners' shoulders and hips, skiers' shoulders and hips, and bikers' hips.
It is, therefore, an object of this invention to provide a soft, comfortable backpack that supports the pack in the comfortable lumbar region of the back, which allows pivotal body motion at hips and shoulders and allows complete adjustability of load location and shoulder harness attachments. It is another object of this invention to provide easy access to water bottles that are contained within thermally insulated holsters.
SUMMARY OF THE INVENTION
In accordance with the present invention, a universally adjustable, frameless backpack is provided. The backpack of the present invention generally stated comprises a nylon cloth body having a plurality of compartments, including a main compartment accessible by a top zipper, two insulated side compartment bottle holsters, a triangular zipper pocket at a center portion of the pack, and, on larger models, a gussetted zipper pocket below the triangular pocket, a shoulder harness, and a hip belt.
A shoulder harness attaches pivotally to the body within a slot between a back pad and the body. It ca be adjusted up or down on a pivot buckle, thereby adapting to different body lengths. The shoulder harness also has adjustable and padded shoulder straps that can also be shortened or lengthened. The shoulder straps are maintained on the shoulders by a shoulder blade strap on the back and a sternum strap on the chest. The front portion of the straps have a diagonally fixed nylon mesh piece on each strap that has a buckle and a mesh piece strap attached to the pack body adjacent the bottle holsters at the sides.
A hip belt and attached hip pad are inserted in a slot between the body and a lumbar pad to support the bulk of the pack weight. It is attached to the body by hook-and-pile (Velcro™) fasteners at the back and a pair of side-support bi-directional compression straps, which each attach to the body at two points. The Velcro™ allows for removal of the belt. The pair of compression straps are attached to the belt by a loop, thereby allowing sliding engagement while maintaining constant compression as the hips rise and fall, for instance, during running or jogging. The angle of the belt on a front portion of the belt pad is also adjustable by another vertical Velcro™ attachment, thereby providing side support adjustment means.
Some of the advantages of the compartment designs include gussetted panels on the main compartment allowing for a neat pack when full or only partially loaded, and the gussetted pocket on the bottom back portion of the pack.
The diagonally oriented zipper on the holster pockets permits the backpacker to reach, unzip, and remove the water bottles from the insulated pockets while walking, without removing the pack from his back. The holster pocket top flaps also can be left open and Velcro™ hooked to the inside of the pocket, allowing quick access to the water bottle.
The triangular pocket is also a handy and convenient pocket for storage of flat objects or papers. It also provides a single attachment point for the torsolink buckle on the back of the harness, termed as the Torso Link Harness System by the inventor. As in most packs in the industry, each zipper has a zipper tab loop to aid in opening the zipper.
The unique Torsolink Harness System™ allows the body to pivot and move with agility while the pack and gear remain in a relatively neutral and vertical position, thus eliminating the horizontal swinging motion which tends to unbalance the athlete and reduce efficiency and speed of motion. This is accomplished by the single torsolink buckle attachment on the back of the pack, the free pivoting shoulder harness attachment at the pivot buckle, and the belt bi-directional compression straps, which allows hips to swivel without excess lower pack motion and the single belt Velcro™ fastener point at the lower center of the pack.
Other objects, advantages, and capabilities of the present invention will become more apparent as the description proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation of the backpack constructed in accordance with the present invention;
FIG. 2 is a back elevation of the invention;
FIG. 3 is a side sectional view of the backpack taken along lines 3--3 of FIG. 1; and
FIG. 4 is a cross-sectional view of a preferred embodiment of a hip pad and shoulder pad materials.
DETAILED DESCRIPTION OF THE INVENTION
A universally adjustable, frameless backpack constructed in accordance with the invention is illustrated in FIGS. 1-3. Referring to FIG. 1, the backpack 10 generally stated includes a body 12, an adjustable shoulder harness 14, and an adjustable and detachable belt 16. An inverted T-shaped back pad 18 is attached to an upper front portion of the body providing a horizontal shoulder harness slot 20. A lumbar pad 22 is attached to a lower body portion also providing a horizontal belt slot 24. The shoulder harness 14 slips into the shoulder harness slot 20 and is pivotally fixed to the body 12. In a similar manner, the belt 16 and attached hip pad 26 are removably fixed to the body 12 within the belt slot 24. FIG. 1 illustrates two of the four or five compartments, i.e., the insulated bottle holsters 28.
The shoulder harness 14 consists of shoulder straps 30 having length-adjusting cam-lock buckles 32. The strap 30 length adjustment permits the wearer to raise or lower the pack position on his back. The harness is held on the chest by a sternum strap 34 and on the shoulders by an adjustable shoulder blade strap 36, which maintain a fixed distance between the shoulder straps 30. Both of these straps can be raised or lowered by inserting the straps within different vertical slots on the shoulder straps. Shoulder pads 38 have a breathable material encased in a nylon mesh to carry moisture away from the backpacker's body. The front portion of the straps 30 are affixed to the body 12 by a diagonal nylon mesh piece 40 and mesh piece straps 42 which attach to the body adjacent to the bottle holsters 28, and are adjustable at typical adjusting belt loop 44.
Belt 16, in addition to being affixed to the body 12 within belt slot 24 is restrained to the body by a pair of bi-directional compression straps 46. These straps pass through belt loops 48 and allow sliding of the belt 46 within the loops 48 as the motion of the wearer's hips cause the belt 16 to move up and down while running, jogging, or ski-ing. The strap length is adjustable at adjusting belt loop 44. The angle of the belt 16 on the wearer's body is also adjustable by positioning the belt up or down on hook-and-pile fastener 50, e.g. Velcro™ or the like.
The pack is removed from the wearer by disengaging the quick-release belt buckle 52 and quick-release sternum buckle 54. The water bottle 56 can be removed from holster 28 by unzipping diagonal zipper 58. Additionally, the holster top flap 60 can be held open and affixed to the inside of the holster 28 by another Velcro™ piece 62 (shown in phantom) so as to give easy and quick access to bottle 56.
Referring now to the back view of FIG. 2, the plurality of compartments can be seen. The wedge-shaped main compartment 70 is accessible by a zipper 72 which runs from one side to the other across a top portion of the pack 10. The wedge shape is constructed by the use of gussets 74 on the lower portion of pack 10. There are also gussets on the bottom 76 of the main compartment 70.
Triangular zipper pocket 78 serves to contain small, flat articles and is also a tie point between shoulder harness 14 and a center portion 80 of body 12. Access to this pocket 78 is at zipper 82.
The tie point identified as torsolink 84 is a triangular shape nylon mesh that joins the two straps 30 as at 86. A torso quick-release buckle 88 joins the torsolink to the triangular pocket 78 so as to transfer a small portion of the pack weight to the shoulders and pulls the top of the pack tight against the back.
On larger pack sizes there is an additional gussetted pocket 90 affixed to a lower back portion of the body 12, having horizontal zipper 92.
The contents of the pack are compacted by a pair of horizontal compression straps 94 which are attached by horizontal quick-release buckles 96 to the bottle holsters and compress a mid-portion 80 and bottom portion 76 of the main compartment 70. The bottom portion 76 is also compacted vertically by a pair of vertical compression straps 98 attached to the body by vertical quick-release buckles 100. The bottom end of straps 98 may be attached to the bottom body portion 76 or to a bottom flap 102 (FIG. 3) which protects the pack 10 when setting on the ground.
Some attachments typical to the pack industry include grab loop 104 and lash point loops 106.
Referring now to the cross-section view of FIG. 3, the details of the harness 14 and pivotal attachment to body 12 can be seen. Shoulder pad V-section 110 and one end of strap 30 is attached to pivot buckle 112. This buckle 112 is adjustably affixed to a vertical harness strap 114 and can be located up or down so as to raise or lower the pack on the wearer's back. A tall person would have the pad 110 and buckle as shown, whereas a short person would locate the buckle 112 at a lower position 116. The back pad 18 and the harness strap 114 attach to the body 12 at a body upper portion 118 and body middle portion 120.
The shoulder straps 30 attach to a front portion 122 of harness 14 and connect together forming a V-shaped joint 86 (FIG. 2) at the back portion of the harness which attaches to the quick-release buckle 88. Buckle 88 which is removably affixed to the triangular pocket 78. The front portion 122 of the harness connects to the body front middle portion 120 adjacent the bottle holsters by the mesh piece strap 42.
One of the novel features of the shoulder harness 14 is the permanently curved contour of the pad 38 and strap 30. This is purposely done by sewing a shorter nylon fabric piece 128 (FIG. 4) on the inside and a longer piece 136 on the outside. This curvature prevents web material 128 from bunching up on the wearer's shoulder, typical of most other shoulder harnesses.
The belt 16 and hip pad 26 attachment behind lumbar pad 22 can be seen in body lower portion 124. Attachment of belt 16 to lower body portion 124 is done by hook-and pile piece 126. The belt comes in three sizes to suit a packer's waist and hip size.
A space above flap 102 can be used for bed roll or sleeping bag stowage by adjusting vertical compression ladder lock buckle 100.
A preferred embodiment of the shoulder pad 38 and hip pad 26 is shown in cross-section FIG. 4. An inside nylon mesh 128 is adjacent the wearer's body and covers a hydrophobic foam 130 that wicks water away from the body. Adjacent the hydrophobic foam 130 is a closed cell foam pad 132 having multiple apertures 134 allowing water vapor to pass through and exit through outer nylon mesh 136. This construction is used on the larger packs to better distribute the compression load from the belt and shoulder harness to the hips and shoulders of the backpackers.
It is apparent from the foregoing that a novel and unobvious backpack has been provided having many useful features that provide for comfort nd motion efficiency of the backpacker or sportsman. The pack is universally adjustable at the many quick-release buckles, belt loops, and cam lock buckles.
While a preferred embodiment of the invention has been disclosed, various modes of carrying out the principles disclosed herein are contemplated as being within the scope of the following claims. Therefore, it is understood that the scope of the invention is not to be limited except as otherwise set forth in the claims. | A universally adjustable frameless backpack is provided for use by the more active sportsperson. The pack has a pivoted shoulder harness that allows the pack to remain relatively stationary while the person's body and shoulders swing back and forth as in jogging, running, or cross-country skiing. The hip pad also has a novel attachment to the pack that allows hip motion without excessive swinging of the pack causing unbalance of the runner or jogger. | 0 |
FIELD OF THE INVENTION
Embodiments of the present invention are directed to photonic circuits and, more particularly, to combining vertical and angled facets in silicon photonic waveguides.
BACKGROUND INFORMATION
Silicon photonic circuits generally route optical signals in planar waveguides, and it is difficult to provide a path for light to enter/exit the circuits vertically. Routing light in or out of the wafer surface can be valuable for several reasons, such as coupling into a normal-incidence photodetector on the wafer surface, for wafer-level optical test/characterization, or other potential applications.
Of particular interest is the integration of planar silicon waveguides with Ge-based photodetectors. This is being addressed in several ways, all of which have various challenges. Planar photodetectors, in which the Ge is grown on top of the Si waveguide are quite large, because the optical coupling is inefficient and a long distance is needed for sufficient coupling of light to occur from the Si to the Ge.
To avoid this difficulty, trench sidewall photodetectors have been proposed, where the waveguide is terminated by a vertical facet. In this case, a facet with sufficient smoothness is difficult to form, and the epitaxial growth of the Ge-based photodetector can be very challenging.
Coupling light to and from planar silicon photonic devices, particularly in a low-cost, high volume manufacturing (HVM) compatible way, represents a significant challenge, and a major hurdle to commercialization. Currently, manual techniques are required to prepare facets on the edges of silicon photonics chips at the die level to couple light to and from the devices.
Currently, input facets are prepared manually by dicing and polishing at the die level. FIG. 1 shows a cross-sectional side view of a photonic waveguide including a Si handle wafer 100 , a buried oxide layer 102 , and an Si device layer 104 . A re-entrant mirror (REM) 106 may be formed in the device layer 104 as similarly described in co-pending application Ser. No. 12/567,601, herein incorporated by reference. A device, such as a photodetector 108 may be over the re-entrant mirror 106 . The coupling of light into and out of the silicon waveguide is done through facets 110 at the die edge that are prepared by dicing and mechanical polishing at die-level. This is a tedious manual process, which is not scalable to HVM. Grating couplers may also be used, but these have high loss for larger (>1 um) waveguide based devices and require a high-profile package, because they are inherently non-planar.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and a better understanding of the present invention may become apparent from the following detailed description of arrangements and example embodiments and the claims when read in connection with the accompanying drawings, all forming a part of the disclosure of this invention. While the foregoing and following written and illustrated disclosure focuses on disclosing arrangements and example embodiments of the invention, it should be clearly understood that the same is by way of illustration and example only and the invention is not limited thereto.
FIG. 1 is side view of a silicon photonic waveguide device having a diced and manually prepared input facet;
FIG. 2 is a top layout view of a silicon waveguide device with a bended waveguide according to one embodiment; and
FIGS. 3A-3G comprise side-by-side side and top views of a wafer illustrating the fabrication steps for creating waveguide device having a re-entrant total internal reflection (TIR) mirror device with an input facet according to one embodiment of the invention.
DETAILED DESCRIPTION
Described is a new way of creating vertical facets to enable light to be coupled edgewise into planar silicon photonic devices, using an HVM-compatible wafer-level crystallographic wet etch process. In addition, embodiments of the invention also describes how such facets may be combined with re-entrant mirrors (REMs) for out-of-plane reflection, which may be useful for SiGe based optical receiver modules, among other uses.
Reference throughout this specification to “one embodiment” or “an embodiment” 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 the phrases “in one embodiment” or “in an embodiment” 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.
FIG. 2 shows a layout top view of the device according to one embodiment. As shown, a Si (110) wafer includes vertical planes (111). A re-entrant (111) mirror may be formed therewith. A waveguide bends approximately 54.7° into the (100) direction waveguide to bring the light from the (111) input facet such that it impinges correctly on the re-entrant (111) mirror angled approximately 35.3° to the wafer plane. This is explained in greater detail below.
Referring to FIG. 3A , there is shown a top view and a side view of one embodiment of the inventive device in the first stages of fabrication. A silicon on insulator wafer comprises an epi Si device layer (110) 300 , atop a buried oxide layer (BOX) 302 on a handle wafer 304 .
FIG. 3B shows the device wafer 300 having a nitride layer 306 patterned 308 on its surface. As shown in FIG. 3C , the Si wafer 300 may be etched down to the buried oxide (BOX) 302 to create a trench 310 using, for example a deep reactive ion etch (DRIE). In FIG. 3D , the oxide layer 302 may be etched, such as by, for example, a wet etch in hydrofluoric acid (HF) to create an undercut area 312 beneath the Si device layer 300 .
Referring now to FIG. 3E , a vertical input (or output) facet 314 may be formed by patterning in the nitride layer 306 . Thereafter a dry etch may be used to etch down to the oxide layer 302 . This dry etch may result in a rather poor quality sidewall, not yet suitable for use as an input facet.
Referring to FIG. 3F the wafer 304 may be wet etched such as by being immersed in a crystallographic etchant such as potassium hydroxide (KOH). In some embodiments, ammonium hydroxide (NH4OH), ethylene diamene pyrocatechol (EDP) or tetramethyl ammonium hydroxide (TMAH) may be used. As shown, this wet etch creates a key hole cavity 320 in the Si waveguide layer 300 the BOX layer 302 and the handle wafer 304 . Optionally, if the handle wafer 304 is prior heavily boron-doped (˜1020 cm-3) by implantation, the handle wafer 304 may not be etched. As shown, this wet etch essentially polishes and creates a smooth surface vertical facet 318 suitable for the input/out of light and, in addition creates the re-entrant mirror (REM) 322 oriented at an angle approximately 35.3° to the horizontal wafer plane.
As shown in FIG. 3G , the nitride layer 306 may be optionally removed. The wafer 304 may be re-planarized by depositing and reflowing a thick oxide layer 400 , for example, to seal the key hole 320 and then dry etched. Alternately a polymeric material may be used for replanarization. According to embodiments, the waveguide 330 in the Si layer 300 should bend at approximately 54.7°, into (100) direction between the input facet 318 and the re-entrant mirror 322 . A photodetector (such as 108 shown in FIG. 1 ) may be formed on the surface of the wafer 300 , positioned above the mirror 322 . Such compact Ge photodetectors can be fabricated using standard surface processing.
In (110) silicon, two families of (111) planes are oriented vertically and 2 families of (111) planes are oriented at an angle of 35.3° to the wafer surface. By laying out the waveguide as shown in FIGS. 2 and 3G , one can combine the vertical input facet 318 with the re-entrant mirror facet 322 . In addition, the 35.3° angle is sufficient for total internal reflection, so the mirror 322 is essentially lossless.
The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation. | Embodiments of the invention use crystallographic etching of SOI wafers with a (110)-oriented epi layer to form both the vertical input facet and the re-entrant mirror. Proposed layout design combined with proposed orientation of the epi enables both vertical facets and re-entrant (upward-reflecting) mirror facets to be made in a single wafer-level wet etch process. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 10/471,327, filed Aug. 16, 2004, which is now U.S. Pat. No. 7,741,029 which is a National Stage application based on International Application No. PCT/CA02/00291, filed Mar. 7, 2002, which claims priority to U.S. Provisional Patent Application No. 60/273,941, filed Mar. 7, 2001, the disclosures of which are incorporated herein by reference.
INCORPORATION OF SEQUENCE LISTING
A computer readable form of the sequence listing, “02833 —0010 U2_Sequence_Listing2.txt” (76569 bytes), submitted via EFS-WEB and created on Oct. 13, 2010, is herein incorporated by reference.
FIELD OF THE INVENTION
The present invention provides novel compositions and methods for use in diagnosing the occurrence of certain serious disorders, especially certain bleeding disorders, and novel compositions and methods for use in treating such a disorder, in a person in which the disorder has occurred, and novel compositions and methods for use in avoiding such a disorder, in an individual who is susceptible thereto.
BACKGROUND OF THE INVENTION
Among the disorders, which the invention concerns, are those involving abnormal and excessive bleeding due to destruction of blood platelets (“platelets”).
These disorders include, but are not restricted to, post-transfusion purpura (“PTP”) and post-transfusion platelet refractoriness (“PTPR”), which are suffered by some persons who receive blood, platelets, leukocyte concentrates, or plasma from other persons by transfusion or the like.
The disorders also include one that is suffered by fetuses and newborns and is known as “neonatal alloimmune thrombocytopenia” (“NATP”). This disorder can cause death of fetuses and serious birth defects or death of newborns. NATP is estimated to affect about 1 in 1000 newborns. In NATP, fetal platelets, which enter the mothers blood stream, induce production in the mother of antibodies directed against fetal platelets. These maternal antibodies then pass with the mothers blood into the fetus and mediate destruction of platelets in the fetus.
A mother, whose fetus or newborn suffers from NATP, is at increased risk of suffering PTP or PTPR.
When platelets from a first human (a “donor”) are introduced into the blood system of a second human (a “recipient”) by transfusion, through the placenta (in the case of fetal blood entering the mother), or the like, the recipient may mount an immune response against the platelets from the donor. Such an immune response is referred to as an “alloimmune” response, because it involves antibodies reacting against antigens of a different individual of the same species. The alloimmune response to platelets is due to an immune response of the recipient against “alloantigens” (antigens of the same species as that mounting the immune response) on platelets from the donor. These alloantigens are found on membrane glycoproteins that occur in the cell membranes, which define the outer surfaces of platelets (“platelet membranes”). In this invention, the glycoprotein is anchored to the membrane in an atypical manner through an anchor consisting of glycosylphosphatidylinositol (GPI), which anchors an extracellular domain or segment of the glycoprotein exposed to the outside of the platelet. It is thought that alloantibodies, which are generated in an alloimmune response against platelet alloantigens, interact with the extracellular domains of the alloantigens.
The platelet alloantigens that a person has are determined by the person's genetics. A donor, because of his or her genetics, may have a platelet alloantigen, which a recipient, who receives blood, platelets, leukocytes or plasma from the donor, does not have, because of the recipient's genetics. In such a situation, the immune system of the recipient may recognize the donor's alloantigen as “non-self,” and raise an immune response against, the platelet alloantigen, which the donor has but the recipient does not.
Membrane glycoprotein alloantigens have been characterised for both human red blood cells and human platelets. It is noteworthy, however, that they also occur on other cell types, such as leukocytes and endothelial cells, where they may also occasion various disorders through alloimmune responses.
Recognised classes of red blood cell and platelet alloantigens have been described, over the past 30 years, based on observations of antibody reactions occurring when blood recipients have been exposed to blood from donors.
A recent review of human platelet alloantigen systems is provided by Ouwehand, W., and Navarrete, C., in Molecular Haematology , Provan, D. and Gribben, J. eds. Blackwell (1999).
Several biallelic platelet alloantigen “systems” have been characterised. In each of these systems, there are two alloantigens, each of which is provided by one of two alleles of the gene comprising the system. Because each gene occurs twice in the normal human genome, a person can be homozygous for one or the other of the two alloantigens, or heterozygous for the two alloantigens, comprising a biallelic system. The alloantigens described to date occur on glycoprotein molecules which may exist in various forms (transmembrane, GPI-linked and soluble, for example). In such a case, the alloantigens are found on each of the variant forms of the glycoprotein. For all of the biallelic platelet alloantigen systems that have been characterised at the level of protein and gene sequences, it has been found in all cases, except for one, that the difference between the two alleles is based on a single nucleotide polymorphism in the relevant gene.
One biallelic system of human platelet alloantigens is the Gov a /Gov b biallelic system associated with CD109, a membrane glycoprotein which occurs on platelets and various other cell types, including leukocytes and endothelial cells. Each Gov allele corresponds to one CD109 glycoprotein (Sutherland, D. R. et al, 1991; Smith et al., 1995; Berry, J. et al., 2000), consistent with the known tissue distribution of CD109. The frequencies for the Gov alleles are 0.4 for Gov a and 0.6 for Gov b in the Caucasian population. Thus, in this population, 40.7% are heterozygous for the Gov alleles, and will not mount an alloimmune response due to Gov incompatibility (not possessing the Gov alloantigen found on platelets received from another). In contrast, 19.8% of Caucasians are homozygous for the Gov a allele and thus may mount an immune response due to Gov alloantigen incompatibility against platelets received from anyone in the 80.5% of the Caucasian population that is not homozygous for the Gov a allele, while 39.8% are homozygous for the Gov b allele and thus may mount an immune response due to Gov alloantigen incompatibility against platelets received from anyone in the 60.2% of the Caucasian population that is not homozygous for the Gov b allele.
As indicated above, alloimmunization based on Gov incompatibility (the introduction into the blood stream of donor platelets bearing a Gov alloantigen not carried by the recipient) can result in bleeding disorders due to platelet destruction, including NATP, PTPR, and PTP. The location of the Gov antigens within the CD109 molecule, and the nature of the CD109 polymorphism which underlies the Gov a /Gov b alloantigen (both at the protein and at the gene level), have not heretofore been known.
Furthermore, it has not heretofore been possible to generate non-human antibody (polyclonal or monoclonal), as from a rat, mouse, goat, chicken, or the like, with specificity for the Gov a alloantigen but not the Gov b alloantigen (or vice-versa) sufficient for use in an immunoassay, for typing for Gov phenotype using platelets or CD109 molecules.
Previously developed technology, involving gene-specific amplification of platelet RNA-derived cDNA, followed by the determination of the nucleotide sequence of the amplified DNA, has been applied successfully to the elucidation of the molecular basis of other biallelic platelet alloantigen systems (Newman et al., J. Clin. Invest. 82, 739-744 (1988); Newman et al., J. Clin. Invest. 83, 1778-1781 (1989) (P1A or HPA-1 system); Lyman et al., Blood 75, 2343-2348 (1990) (Bak or HPA-3system); Kuijpers et al., J. Clin. Invest. 89, 381-384 (1992) (HPA-2 or Ko system); Wang et al., J. Clin. Invest. 90, 2038-2043 (1992) (Pen system). With one exception, it has been found in each case that a single amino acid difference at a single position differentiates the amino acid sequences of the two alleles, and that this difference arises from a single allele-specific nucleotide substitution in the coding region of the mRNA and gene. There remains a need to elucidate the molecular basis of the biallelic Gov platelet alloantigen system.
SUMMARY OF THE INVENTION
The Gova/Govb Cd109 Single Nucleotide Polymorphism
We have now discovered that a single amino acid difference in the CD109 glycoprotein distinguishes the Gov a and Gov b allelic forms. The two alleles differ at amino acid position 703 of the full-length 1445 amino acid CD109 molecule, with the Gov a allele [SEQ ID NO:2] containing a Tyr at this position, while the Gov b allele [SEQ ID NO:4] contains Ser.
Further, we have discovered that this difference in amino acid sequence between the allelic forms of CD109 is due to a single nucleotide polymorphism at position 2108 of the coding portion of full-length mRNA encoding CD109, or of the corresponding coding strand of the cDNA corresponding to this mRNA. Specifically, the Gov a allele [SEQ ID NO:1] contains adenine at position 2108, the second nucleotide of the codon encoding the amino acid at position 703 of the full-length CD109 protein, while the Gov b allele contains cytosine at position 2108, as shown in SEQ ID NO:3
The Gov a /Gov b single nucleotide polymorphism of CD109, lies at position 2108 in SEQ ID NO:1. SEQ ID NO:1 is the cDNA sequence encoding the full-length 1445 amino acid CD109 precursor encoding the Gov a allele In the Gov b allele form [SEQ ID NO:3], C occurs at position 2108, rather than A. The ATG at the 5′-end of the sequence in SEQ ID NO:1 corresponds to the translation start of the full-length precursor form (including leader peptide) of CD109. The triplet corresponding to the N-terminal amino acid of the mature CD109 protein is at positions 64-66 in SEQ ID NO:1.
The Gov a /Gov b single nucleotide polymorphism of CD109, lies at position 954 in SEQ ID NO:5. SEQ ID NO:5 is the genomic DNA sequence of human CD109 exon 19 and the contiguous introns, introns 18 and 19. The Gov a /Gov b single nucleotide polymorphism of CD109 is found within CD109 exon 19, and specifically is located at position 3 of CD109 exon 19. The sequence presented in SEQ ID NO:5 contains A at position 954, and thus corresponds to the Gov a allele. The corresponding Gov b sequence contains C at position 954 of SEQ ID NO:5 (nucleotide position 3 of exon 19).
In view of this discovery, it will be readily apparent to the skilled what the present invention provides:
Gov allele-specific oligonucleotides and polynucleotides: Based on the discovery, the present invention provides oligonucleotides and polynucleotides (seems repetitive), including (but not limited to) probes which can be used to determine whether a person is homozygous for one or the other of the Gov alleles, or heterozygous for these alleles, thereby to determine that person's Gov genotype, and by extension, their Gov phenotype (i.e., the Gov alloantigen(s) which their cells express). Further, the invention provides methods of using such oligonucleotides, and test kits to facilitate their use, in such Gov genotype and phenotype determinations. These oligonucleotides of the invention can be used to determine whether, in the CD109 gene, or in the mRNA encoding CD109, the internal nucleotide (nucleotide 2108) of the codon (in CD109 gene or in the mRNA encoding CD109) which corresponds to the amino acid at position 703 in the sequence of full-length CD109 is adenine or cytosine. Such probes will typically be cDNA but may be genomic DNA, mRNA or RNA, and may be labelled for detection. The oligonucleotides of the invention can be used as probes to detect nucleic acid molecules according to techniques known in the art (for example, see U.S. Pat. Nos. 5,792,851 and 5,851,788).
For example, an oligonucleotide of the invention may be converted to a probe by being end-labelled using digoxigenin-11-deoxyuridine triphosphate. Such probes may be detected immunologically using alkaline-phosphate-conjugated polyclonal sheep antidigoxigenin F(ab) fragments and nitro blue tetrazolium with 5-bromo-4-chloro-3-indoyl phosphate as chromogenic substrate.
Gov allele-specific antibodies: Still further, based on the discovery, which underlies the invention, of the molecular basis for the Gov a /Gov b alloantigen system, the invention provides non-human polyclonal and monoclonal antibodies, which can be used to distinguish one Gov allelic form of CD109 from the other, whether the CD109 is part of a complex embedded in or isolated from a membrane or is isolated. These antibodies of the invention, which are preferably provided in an aqueous buffer solution, and the immunoassays of the invention which employ such antibodies, are useful for determining whether a person has one or both of the Gov alloantigens and for Gov phenotyping. Methods of using the antibodies of the invention in the immunoassays of the invention, and in such determinations, are also encompassed by the invention. The invention also provides test kits to facilitate carrying out such immunoassays and determinations.
Gov allele-specific peptides and polypeptides: Again, based on the discovery that underlies the invention, of the molecular basis for the Gov a /Gov b alloantigen system, the invention provides peptides or polypeptides, which are useful for various purposes. These peptides or polypeptides are typically between 4 and 100, and more typically between 7 and 50, amino acids in length, and have amino acid sequences identical or having sequence identity to those of segments of the CD109 sequences, that include the amino acid at position 703 of full-length mature CD109. This amino acid (position 703) corresponds the triplet at positions 2107-2109 in the CD109 cDNA sequence presented in SEQ ID NO:1, or in the corresponding sequence for the CD109 cDNA that encodes the Gov b allelic form [SEQ ID NO:3]. These peptides or polypeptides may be synthetic, may be purified from native CD109 or may be prepared by recombinant means. For guidance, one may consult the following U.S. Pat. Nos. 5,840,537, 5,850,025, 5,858,719, 5,710,018, 5,792,851, 5,851,788, 5,759,788, 5,840,530, 5,789,202, 5,871,983, 5,821,096, 5,876,991, 5,422,108, 5,612,191, 5,804,693, 5,847,258, 5,880,328, 5,767,369, 5,756,684, 5,750,652, 5,824,864, 5,763,211, 5,767,375, 5,750,848, 5,859,337, 5,563,246, 5,346,815, and WO9713843. Many of these patents also provide guidance with respect to experimental assays, probes and antibodies, methods, transformation of host cells, which are described below. These patents, like all other patents, publications (such as articles and database publications) in this application, are incorporated by reference in their entirety.
Gov allele-specific peptides and polypeptides as antigens and immunogens, and Gov allele-specific polyclonal and monoclonal antibodies: These peptides or polypeptides are useful as antigens (usually coupled to a larger, immunogenic carrier [proteinaceous or otherwise], as known in the art) for making the polyclonal or monoclonal antibodies of the invention. The peptides or polypeptides are also useful in screening monoclonal antibody-producing cultures (hybridoma cultures/ E. coli cultures or so-called V gene phage antibodies) to identify those that produce monoclonal antibodies of the invention.
The invention also encompasses immunogenic compositions which comprise a peptide, polypeptide or fusion compound of the invention and which are immunogenic in a bird, including, without limitation, a chicken, or a mammal, such as, a mouse, rat, goat, rabbit, guinea pig, sheep or human. The compositions may include an immunogenicity-imparting “carrier” which may be but is not necessarily a protein as known in the art, that is immunogenic in a bird or mammal, coupled to at least one peptide or polypeptide of the invention, which has an amino acid sequence that is the same as that of a segment of the sequence for CD109, that includes the amino acid at position 703 of the full length CD109 molecule.
The present invention also provides methods of using the peptides, polypeptides and immunogenic compositions of the invention for making antibodies of the invention, and methods of using the peptides and polypeptides of the invention in screening monoclonal antibody-producing hybridoma cultures or bacterial clones for those that produce monoclonal antibodies or fragments thereof of the invention.
Therapeutic and diagnostic application of Gov allele-specific peptides, polypeptides, and antibodies: These peptides or polypeptides, as well as antibodies, which are specific for the Gov a [SEQ ID NO:2] or Gov b [SEQ ID NO:4], but not both, allelic forms of CD109 in the platelet membrane, and which can be produced by a mammal (including an human) immunized with the peptides or polypeptides, which themselves happen to be immunogenic, or the immunogenic compositions of the invention, are also useful both therapeutically and diagnostically. The invention also provides the methods of using the peptides and polypeptides of the invention, and antibodies made using the peptides that are immunogenic and the immunogenic compositions of the invention, in therapeutic and diagnostic applications.
The Gov allele-specific peptides or polypeptides can also be used diagnostically to detect the presence of Gov a or Gov b specific antibodies in human plasma or serum samples, using methods that are readily apparent to those skilled in the art. Such analyses would be useful in the investigation of cases of acquired alloimmune thrombocytopenia, including PTP, PTPR, and NATP. In the latter case, this approach could also be used to detect the presence of Gov allele-specific antibodies in the mother of the affected fetus or newborn. The presence of Gov allele-specific antibodies can also be detected using platelets of known Gov phenotype. However, this approach has numerous technical disadvantages that are eliminated by the use of Gov allele-specific peptides or polypeptides for Gov allele-specific antibody detection.
Administration to a person, who is suffering from, or at risk for, for example, PTP or PTPR, or a mother at risk for passing NATP-causing alloantibodies to her fetus, of one of the peptides or polypeptides, that would be bound by the anti-Gov alloantibodies in such a person, would inhibit the binding of the alloantibodies to the person's (or the fetus's platelets and thereby inhibit the platelet destruction and abnormal bleeding associated with the disorders. Alternatively, administration to such a person of antibodies (particularly human antibodies), which are produced using a peptide or polypeptide of the invention, which is immunogenic by itself, or an immunogenic composition of the invention, and which are specific for the Gov allelic form of the CD109 on the person's platelets which is associated with the PTP or PTPR, from which the person is suffering or may suffer, would induce the production of anti-idiotypic antibodies, which, in turn, would inhibit the platelet-destructive effects of the anti-Gov alloantibodies, which are generated by the person's own immune system and which are causing or threatening to cause the PTP, PTPR or NATP. These therapeutic applications of peptides and polypeptides of the invention would be especially useful in treating NATP in a newborn, because the alloantibody giving rise to NATP in the newborn is not continuously produced by the immune system of the newborn, but rather is acquired passively, and therefore in limited, non-replenished quantity, by the newborn from its mother.
Thus, in accordance with one aspect of the present invention, an oligonucleotideprobe is provided that hybridizes to a portion of the CD109 gene, or a portion of CD109-encoding mRNA or cDNA prepared from such mRNA, which portion includes a nucleotide corresponding to the internal nucleotide of the codon for the amino acid at position 703 of the full-length CD109 molecule, and that is capable of distinguishing one Gov allele from the other through the ability to hybridize under stringent conditions to the portion in question only when the nucleotide in question is A (or dA), when the probe is to detect the Gov a allele, or C (or dC), when the probe is to detect the Gov b allele. The nucleotide in question is at position 2108 of the coding region of the CD109 cDNA sequence and lies at position 2108 in SEQ ID NO:1. The cDNA sequence has A at this position, and so is the sequence corresponding to the Gov a allele. The nucleotide in question lies at position 954 of the sequence presented as SEQ ID NO:5 and contains an A in this position, and thus also corresponds to Gov a allele.
The Gov allele-specific oligonucleotide hybridization probes of the invention may comprise genomic DNA, cDNA, or RNA, although preferably it is DNA. Such oligonucleotide probes can be synthesised by automated synthesis and will preferably contain about 10-30 bases, although as understood in the oligonucleotide probe hybridization assay art, as few as 8 and as many as about 50 nucleotides may be useful, depending on the position within the probe where the potential mismatch with the target is located, the extent to which a label on the probe might interfere with hybridization, and the physical conditions (e.g., temperature, pH, ionic strength) under which the hybridization of probe with target is carried out.
In accordance with another aspect of the present invention, a test kit for Gov alloantigen typing is provided comprising:
(a) means for amplifying nucleic acid that comprises at least a portion of a CD109 gene, a CD109-encoding mRNA, or a CD109 cDNA made from such RNA, wherein the portion includes a nucleotide (nucleotide 2108 in SEQ ID NO:1, or nucleotide 954 in SEQ ID NO:5) corresponding to the internal nucleotide of the codon encoding amino acid 703 of the full length CD109 protein.
(b) an oligonucleotide probe of the invention, that distinguishes one Gov allele from the other. The “means for amplifying” will, as the skilled will readily understand, depend on the amplification method to be used. Thus, for example, these means might include suitable primers, a suitable DNA polymerase, and the four 2′-deoxyribonucleoside triphosphates (dA, dC, dG, dT), if amplification is to be by the PCR method. To cite another example, if the amplification is to be by a method relying on transcription, such as the 3SR method, the means will include two primers, at least one of which, when made double-stranded, will provide a promoter, an RNA polymerase capable of transcribing from that promoter, a reverse transcriptase to function in primer-initiated, DNA-directed and RNA-directed, DNA polymerization and possibly also in RNAse H degradation of RNA to free DNA strands from RNA/RNA hybrids, the four ribonucleoside triphosphates (A, C, G and U), and the four 2′-deoxyribonucleoside triphosphates. In another example, if the amplification is by the ligase chain reaction, the means will include two oligonucleotides (DNAs) and a suitable DNA ligase that will join the two if a target, to which both can hybridize adjacent to one another in ligatable orientation, is present.
The oligonucleotide probes of the invention will preferably be labelled. The label may be any of the various labels available in the art for such probes, including, but not limited to 32 P; 35 S; biotin (to which a signal generating moiety, bound to or complexed with avidin can be complexed); a fluorescent moiety; an enzyme such as alkaline phosphatase (which is capable of catalysing a chromogenic reaction); digoxigenin, as described above; or the like.
As indicated in the examples, RFLP analysis can be employed, using BstNI (or isoschizomers thereof), in analysing cDNA or genomic DNA (with or without amplification) to determine Gov genotype. As indicated further in the examples, electrophoretic SSCP analysis may be used to determine Gov genotype. And as indicated in the examples, the hybridization studies outlined above may use fluorescent probes, and may be directly coupled to the DNA amplification step, as in “Real-Time PCR” or related methods.
There has also been provided, in accordance with another aspect of the present invention, a method of typing for Gov allele-specific target sequence in a CD109 nucleic acid derived from a subject, comprising the steps of,
(a) obtaining, by a target nucleic acid amplification process applied to mRNA from human platelets, endothelial cells, or T cells, an assayable quantity of amplified nucleic acid with a sequence that is that of a subsequence (or the complement of a subsequence) of the mRNA that encodes a CD109 said subsequence including the nucleotide at the position in the mRNA corresponding to position 2108 in SEQ ID NO:1 or to nucleotide 954 in SEQ ID NO:5; and
(b) analyzing (e.g., in a nucleic acid probe hybridization assay employing an oligonucleotide probe or probes according to the invention) the amplified nucleic acid obtained in step (a) to determine the base or bases at the position in the amplified nucleic acid that corresponds to position 2108 in SEQ ID NO:1 or to nucleotide 954 in SEQ ID NO:5. It is noteworthy that, if the product of the amplification is double-stranded DNA, analysis for Gov genotype can be carried out by a RFLP (restriction fragment length polymorphism) analysis comprising exposing the amplified DNA to the restriction endonuclease BstNI (or isoschizomer thereof) under conditions whereby the DNA will be cleaved if it includes a site for cleavage by that enzyme. Such DNA, prepared from mRNA encoding the Gov b alloantigen, containing a C rather than an A at the position corresponding to nucleotide 2108 in SEQ ID NO:1 (or to nucleotide 954 in SEQ ID NO:5), includes a recognition site for that endonuclease, while such DNA prepared from mRNA encoding the Gov a alloantigen, does not. If the analysis, by whatever method, of the amplified nucleic acid reveals that there is only an A (or dA) at the position corresponding to position 12108, the platelets (and blood from which they came) have only the Gov a alloantigen, and the individual from whom the platelets came, is homozygous for Gov a . Alternatively, if the analysis of the amplified nucleic acid reveals that there is only a C (or dC) at the position corresponding to position 2108, the platelets (and blood from which they came) have only the Gov b alloantigen and the individual, from whom the platelets came, is homozygous for the Gov b allele. Finally, if the analysis indicates that there is either an A (or dA) or a C (or dC) at that position, the platelets (and blood from which they came) have both Gov alloantigens, and the individual from whom the platelets came, is heterozygous for Gov alloantigen.
In one application of the typing methods of the invention, the methods are applied to two individuals to determine whether blood or platelets from one would provoke an alloimmune response, and possibly PTP or PTPR, in the other. The typing method can be applied with a man and a woman, who are contemplating conceiving or have conceived a child together, to determine the risk that the child would be at risk for NATP and the risk that the woman would be at increased risk for PTP or PTPR. If the woman were heterozygous for the Gov alloantigens there would be, due to Gov alloantigen incompatibility, no risk of NATP and no increased risk for the woman of PTP or PTPR. If, however, the woman were homozygous for one of the Gov alloantigens, there would be, due to Gov alloantigen incompatibility, risk of NATP in a child and increased risk of PTP or PTPR for the woman, unless the man is homozygous for the same Gov alloantigen as is the woman.
In accordance with yet another aspect of the present invention, a method of typing an individual for Gov alloantigen is provided that comprises analyzing the genomic DNA of the individual to determine the Gov alloantigen(s) of the individual. Applications of this method are substantially the same as those of the method of the invention for typing for Gov alloantigen that begins with platelet, endothelial cell, or T cell mRNA.
This method of the invention, entailing analysis of genomic DNA, can be carried out in substantially the same way as outlined above for analysis of mRNA, namely first amplifying the genomic DNA and then analyzing to product of the amplification to ascertain whether there is only dA, only dC, or both dA and dC, at the position in the coding region of the genomic DNA corresponding to position 2108 in SEQ ID NO:1, or to nucleotide 954 in SEQ ID NO:5.
In accordance with a further aspect of the present invention, a test kit for Gov alloantigen typing is provided comprising a non-human antibody (or antibodies) that distinguishes the two allelic forms of CD109. The antibody (or antibodies) of the kit may be polyclonal, or preferably monoclonal, and in addition to its (their) specificity for either but not both Gov alloantigens (on the surface of platelets or separated therefrom) or the CD109 subunit of one but not both of such alloantigens, typically will recognise a polypeptide molecule encoded by a nucleotide sequence encoding at least amino acid 703 of a CD109 polypeptide (the amino acid at the position corresponding to nucleotides 2107-2109 in SEQ ID NO:1, or to nucleotides 953-955 in SEQ ID NO:5).
The invention relates to an oligonucleotide comprising a sequence which binds specifically to (i) a region of CD109 nucleic acid that includes a single nucleotide polymorphism that is distinctive of a Gov a allele and/or (ii) a region of CD109 nucleic acid that includes a single nucleotide polymorphism that is distinctive of a Gov b allele. The oligonucleotide optionally comprises 8 to 50 nucleotides. The oligonucleotide preferably specifically binds to one of (i) or (ii) under high stringency hybridization conditions. The stringent hybridization conditions optionally comprise 0.1×SSC, 0.1% SDS at 65° C. The CD109 nucleic acid optionally comprises genomic DNA, cDNA, or RNA corresponding to the Gov a allele of the CD109 gene or locus, or comprises genomic DNA, cDNA, or RNA corresponding to the Gov b allele of the CD109 gene or locus. The Gov a allele optionally comprises an A at a position corresponding to position 2108 of SEQ ID NO:1 and corresponding to position 954 of SEQ ID NO:5. The Gov b allele optionally comprises a C at a position corresponding to position 2108 of SEQ ID NO:3 and corresponding to position 954 of SEQ ID NO:5. The oligonucleotide optionally comprises a sequence complementary to the Gov a allele or to the Gov b allele. The oligonucleotide optionally comprises a sequence selected from the group consisting of:
(a) 8-50 nucleotides of SEQ ID NO:1;
(b) a sequence that is complementary to a sequence specified in (a); and
(c) a sequence having at least 70% sequence identity to a sequence in (a) or (b), wherein the sequence having identity is capable of hybridization to CD109 under high stringency hybridization conditions.
The oligonucleotide optionally comprises a sequence selected from the group consisting of:
(a) 8-50 nucleotides of SEQ ID NO:3;
(b) a sequence that is complementary to a sequence specified in (a); and
(c) a sequence having at least 70% sequence identity to a sequence in (a) or (b), wherein the sequence having identity is capable of hybridization to CD109 under high stringency hybridization conditions.
The oligonucleotide optionally comprises all or part of any one of SEQ ID NO:6-SEQ ID NO:14 or a complement thereof. The oligonucleotide optionally comprises 8 to 50 nucleic acids. The nucleic acid is capable of use as a probe in a hybridization assay. The nucleic acid sequence is typically detectably labelled. The detectable label optionally comprises:
(a) a fluorogenic dye; and/or
(b) a biotinylation modification; and/or
(c) a radiolabel.
The oligonucleotide sequence optionally comprises DNA, a DNA analog, RNA or an RNA analog. The oligonucleotide is optionally attached to a substrate. The oligonucleotide is optionally capable of use as a primer that will specifically bind proximate to, and/or cause elongation through, a CD109 sequence, including the single nucleotide polymorphism distinctive of the Gov a or Gov b alleles.
Another aspect of the invention relates to a Gov genotyping kit comprising a detection agent for detecting the presence of a Gov allele-specific target sequence in a CD109 nucleic acid derived from a subject. The detection agent optionally comprises a nucleic acid and/or a restriction enzyme. The kit optionally further comprises a container. The container optionally comprises a biological sample container for housing the detection agent. The kit optionally further comprises a plate having a plurality of wells and having bound thereto probes having a nucleic acid sequence which specifically binds to a CD109 sequence including a Gov a or a Gov b allele target sequence. The restriction enzyme is optionally selected from the group consisting of Bst2UI, BstNI, BstOI, EcoRII, MaeIII, MspR91, MvaI, ScrFI or an isoschizomer thereof. The kit optionally further comprises an amplification agent for amplifying the nucleic acid. The amplification agent amplifies a region of CD109 platelet, T cell, or endothelial cell mRNA including the single nucleotide polymorphism distinctive of a Gov a or Gov b allele. The amplification agent optionally comprises a primer set including first and second primers, wherein the first primer is a nucleic acid that will specifically bind proximate to, and/or cause elongation through, CD109 sequence that includes the single nucleotide polymorphism distinctive of a Gov a allele and the second primer is a nucleic acid that will specifically bind proximate to, and/or cause elongation through, CD109 sequence that includes the single nucleotide polymorphism distinctive of a Gov b allele. The nucleic acid is optionally obtained by amplification with all or part of the nucleic acid of any one of SEQ ID NO:6-SEQ ID NO:14 or the complement thereof. The kit optionally further comprises all or part of a CD109 gene, a CD109-encoding mRNA, or a CD109 cDNA made from a CD109-encoding mRNA. The kit optionally further comprises the oligonucleotide of the invention. The kit is useful for detecting that the subject has or is at risk of a disease, disorder or abnormal physical state, such as a blood disease, disorder or abnormal physical state which in some cases may comprise bleeding of the subject, or increased risk of bleeding, due to destruction of blood platelets. The blood disease, disorder or abnormal physical state will often be post-transfusion purpura (“PTP”), post-transfusion platelet refractoriness (“PR”) or neonatal alloimmune thrombocytopenia (“NAIT”). The nucleic acid for the kit and methods is usually obtained from mRNA from human platelets, T cells, endothelial cells, or human genomic DNA.
Another aspect of the invention relates to a method of Gov alloantigen genotyping a subject comprising:
(a) providing a CD109 nucleic acid sample derived from the subject; and
(b) detecting a region of CD109 nucleic acid that includes a single nucleotide polymorphism distinctive of a Gov a or a Gov b allele.
The method preferably comprises determining whether the subject is homozygous or heterozygous for the Gov alleles. The subject of the methods will typically be a human and the Gov genotype is used to determine that the subject has, or is at risk of a disease, disorder or abnormal physical state, such as a blood disease, disorder or abnormal physical state for example, comprising bleeding of the subject, or increased risk of bleeding, due to destruction of blood platelets. Examples of blood disease, disorder or abnormal physical state include post-transfusion purpura (“PTP”), post-transfusion platelet refractoriness (“PR”) or neonatal alloimmune thrombocytopenia (“NAIT”). The nucleic acid is typically obtained by amplifying the nucleic acid from the subject. The nucleic acid is preferably obtained by amplification with all or part of an oligonucleotide of the invention. The nucleic acid is typically obtained from mRNA from human platelets, T cells, endothelial cells, or human genomic DNA. The detection step optionally comprises determining the nucleotide sequence of the CD109 nucleic acid or contacting the nucleic acid with the oligonucleotide under high stringency conditions. In a hybridization step, the oligonucleotide will optionally selectively hybridize to (i) a region of CD109 nucleic acid that includes a single polymorphism distinctive of a Gov a allele or (ii) a region of CD109 nucleic acid that includes a single polymorphism distinctive of a Gov b allele. The detecting step optionally comprises:
(a) performing a restriction endonuclease digestion of the nucleic acid, thereby providing a nucleic acid digest; and
(b) contacting the digest with the oligonucleotide.
Hybridization optionally occurs either during or subsequent to PCR amplification and the analysis is optionally by “Real-Time” PCR analysis, or fluorimetric analysis. The detection step optionally comprises:
(a) incubation of the amplified nucleic acid with a restriction endonuclease under conditions whereby the DNA will be cleaved if the nucleic acid comprises a recognition site for the enzyme; and
(b) determining whether the nucleic acid contains a recognition site for the restriction enzyme characteristic of cDNA made from mRNA encoding a Gov a or Gov b allele of CD109.
The restriction enzyme is, for example, selected from the group consisting of Bst2UI, BstNI, BstOI, EcoRII, MaeIII, MspR91, MvaI, ScrFI or an isoschizomer thereof. The determination step optionally includes size analysis of the nucleic acid. The amplified nucleic acid is optionally analyzed by electrophoretic mobility and the mobility of the amplified nucleic acid is compared to the characteristic mobility of amplified nucleic acid fragments corresponding to the Gov a or Gov b alleles of CD109. The method of amplifying CD109 mRNA optionally comprises amplifying the mRNA by PCR using an oligonucleotide of the invention.
Another aspect of the invention relates to a Gov a specific antibody. The antibody that recognizes specifically a Gov a allele-specific CD109 epitope corresponding to the polypeptide encoded by a CD109 nucleic acid optionally contains an A at the position corresponding to position 2108 of SEQ ID NO:1 and position 954 of SEQ ID NO:5, and containing the amino acid Tyrosine at the position corresponding to position 703 of the CD109 protein encoded by SEQ ID NO:1. Another aspect of the invention relates to a Gov b specific antibody. The antibody that recognizes specifically a Gov b allele-specific CD109 epitope corresponding to the polypeptide encoded by a CD109 nucleic acid optionally contains a C at the position corresponding to position 2108 of SEQ ID NO:3 and position 954 of SEQ ID NO:5, and containing the amino acid Serine at the position corresponding to position 703 of the CD109 protein encoded by SEQ ID NO:3. The antibody is typically a monoclonal antibody or a polyclonal antibody and further comprises a detectable label. Another aspect of the invention relates to an immunogenic composition comprising a Gov specific antibody. The method of Gov alloantigen phenotyping a subject, optionally comprises:
(a) providing a CD109 polypeptide sample derived from the subject; and
(b) detecting the presence of a Gov a or a Gov b antigen in the CD109 polypeptide.
The CD109 is typically membrane bound CD109 or isolated CD109. The detection step optionally comprises contacting the polypeptide sample with an antibody described herein. A diagnostic kit for Gov alloantigen phenotyping a subject, optionally comprises a Gov a antibody and/or a Gov b antibody of the invention. The kit optionally further comprises a container.
The invention also includes an isolated polypeptide containing a Gov a allele-specific amino acid sequence and which is specifically reactive with a Gov a antibody. The invention also includes an isolated polypeptide containing Gov b allele-specific amino acid sequence and which is specifically reactive with a Gov b antibody. The isolated polypeptide optionally comprises between 4 and 100 amino acids. The isolated polypeptide also optionally comprises a full-length CD109 polypeptide, or a fragment of a CD109 polypeptide. The invention also includes an isolated CD109 polypeptide fragment, comprising a Gov a or a Gov b antigen.
The polypeptide fragment optionally comprises all of, or a fragment of, the protein encoded by SEQ ID NO:1, and in which the amino acid corresponding to position 703 of the protein encoded by SEQ ID NO:1 is a Tyrosine. The polypeptide fragment optionally comprises all of, or a fragment of, the protein encoded by SEQ ID NO:3, and in which the amino acid corresponding to position 703 of the protein encoded by SEQ ID NO:3 is a Serine. The polypeptide fragment optionally comprises between 4 and 100 amino acids. The polypeptide fragment optionally comprises between 7 and 50 amino acids. The polypeptide is optionally purified from native CD109, or is synthetic, or is prepared by recombinant means. The polypeptide fragment is optionally bound to a substrate. The invention also includes a fusion compound comprising the polypeptide of the invention connected to an immunogenic carrier. The fusion compound typically includes an immunogenic carrier comprising a proteinaceous carrier. The immunogenic carrier optionally comprises a detectable label. The invention also includes a Gov a or Gov b specific antibody recognizing the fusion compound. The invention also includes an immunogenic composition comprising the polypeptide, polypeptide fragment or fusion compound. Another aspect of the invention relates to a method of producing a Gov a or Gov b specific antibody, comprising contacting an animal with the immunogenic composition so that the animal produces antibodies against the immunogenic composition. The animal is typically a bird or a mammal.
The invention also includes a method of screening an antibody producing culture to determine whether the culture produces Gov a or Gov b specific antibody, comprising:
(a) contacting a polypeptide of the invention with the culture; and
(b) detecting Gov a or Gov b specific antibody.
The polypeptide typically comprises a detectable label. The polypeptide is optionally attached to a substrate. The invention also includes a method of purifying a Gov allele-specific antibody from a sample, comprising:
(a) contacting a Gov allele-specific antibody with a polypeptide of the invention comprising a Gov a or Gov b antigen, so that an antibody:polypeptide complex is formed;
(b) separating the complex from the sample; and
(c) next separating the antibody from the polypeptide.
The polypeptide is optionally bound to a substrate. The polypeptide optionally comprises a detectable label. Another aspect of the invention relates to a method of purifying a Gov polypeptide from a sample, comprising:
(a) contacting a Gov allele-specific antibody with a polypeptide of the invention containing a Gov a or Gov b -specific epitope, so that an antibody:polypeptide complex is formed;
(b) separating the complex from the sample; and
(c) next separating the antibody from the polypeptide.
The antibody is optionally bound to a substrate. The antibody optionally comprises a detectable label.
The invention also includes a method of screening a subject sample to determine whether the sample contains Gov a or Gov b -specific antibodies, comprising:
(a) contacting a polypeptide of the invention with the sample; and
(b) detecting the presence or absence of Gov a or Gov b specific antibody.
The polypeptide optionally comprises a detectable label. The polypeptide is optionally attached to a substrate. The subject optionally comprises a mother of a fetus or a newborn infant, or the fetus or newborn infant itself, and the presence of Gov a or Gov b -specific antibody indicates that the fetus or infant has, or is at risk of NAIT. In such a case, the presence of Gov a or Gov b specific antibody indicates that the subject has, or is at risk of a blood disease, disorder or abnormal physical state, for example, that comprises bleeding of the subject, or increased risk of bleeding, due to destruction of blood platelets. The blood disease, disorder or abnormal physical state typically comprises post-transfusion purpura (“PTP”), post-transfusion platelet refractoriness (“PR”) or neonatal alloimmune thrombocytopenia (NAIT). The sample optionally comprises human serum or plasma. Another aspect of the invention relates to a diagnostic kit for detection of Gov a or Gov b specific antibody, comprising a polypeptide described herein. The kit optionally further comprises a container.
Another aspect of the invention relates to a method of determining Gov antibody specificity, comprising:
(a) contacting an antibody with a first polypeptide comprising a Gov a antigen and a second polypeptide comprising a Gov b antigen; and
(b) determining whether the antibody binds to either or both of the first and second polypeptide.
Another aspect involves a method of blocking Gov a antibody binding to an antigen, comprising: contacting the antibody with a polypeptide of the invention comprising a Gov a antigen so that an antibody:polypeptide complex is formed. The polypeptide optionally comprises a detectable label. The polypeptide is optionally bound to a substrate. The invention also includes a pharmaceutical composition comprising the polypeptide. Another aspect of the invention relates to a method of immunizing a subject so that the subject will produce anti-idiotypic antibodies, comprising administering to the subject the immunogenic composition.
The invention also includes a method of blocking Gov a or Gov b specific antibodies from binding to CD109 in a subject, comprising: administering to the subject polypeptides of the invention capable of binding to Gov a and/or Gov b specific antibodies. The subject has or is at risk of a blood disease, disorder or abnormal physical state. The polypeptide optionally comprises a detectable label. The binding of the polypeptide to the Gov a or Gov b specific antibody prevents alloimmune cell destruction by the antibody. The binding of the polypeptide to the Gov a or Gov b -specific antibody depletes the antibody. The blood disease, disorder or abnormal physical state typically comprises bleeding of the subject, or increased risk of bleeding, due to alloimmune destruction of blood platelets, such as post-transfusion purpura (“PTP”), post-transfusion platelet refractoriness (“PR”) or neonatal alloimmune thrombocytopenia (“NAIT”).
DETAILED DESCRIPTION OF THE INVENTION
Definitions
The following definitions are provided in order to aid those skilled in the art in understanding the detailed description of the present invention.
The term “alloantigens” refers to antigens of an individual that are responsible for eliciting an alloimmune response.
The phrase “alloimmune response” refers to an immune response, which occurs when antibodies from one individual react against antigens of a different individual of the same species.
The phrase “anti-idiotypic antibodies” refers to antibodies which can bind endogenous or foreign idiotypic antibodies and which can be used to treat or prevent pathological conditions associated with an immune response to a foreign alloantigen.
The phrase “Gov a /Gov b biallelic system” refers to a system of human platelet alloantigens in which an individual can be homozygous for either Gov a or Gov b allelic forms of CD109, or an individual can be Gov a /Gov b heterozygous for CD109.
“GPI” refers to glycosylphosphatidylinositol.
The term “NATP” refers to neonatal alloimmune thrombocytopenia.
“Nucleic acid” includes DNA and RNA, whether single or double stranded. The term is also intended to include a strand that is a mixture of nucleic acids and nucleic acid analogs and/or nucleotide analogs, or that is made entirely of nucleic acid analogs and/or nucleotide analogs.
“Nucleic acid analogue” refers to modified nucleic acids or species unrelated to nucleic acids that are capable of providing selective binding to nucleic acids or other nucleic acid analogues. As used herein, the term “nucleotide analogues” includes nucleic acids where the internucleotide phosphodiester bond of DNA or RNA is modified to enhance biostability of the oligomer and “tune” the selectivity/specificity for target molecules (Ulhmann, et al., 1990, Angew. Chem. Int. Ed. Eng., 90: 543; Goodchild, 1990, J. Bioconjugate Chem., I: 165; Englisch et al., 1991, Angew, Chem. Int. Ed. Eng., 30: 613). Such modifications may include and are not limited to phosphorothioates, phosphorodithioates, phosphotriesters, phosphoramidates or methylphosphonates. The 2′-O-methyl, allyl and 2′-deoxy-2′-fluoro RNA analogs, when incorporated into an oligomer show increased biostability and stabilization of the RNA/DNA duplex (Lesnik et al., 1993, Biochemistry, 32: 7832). As used herein, the term “nucleic acid analogues” also include alpha anomers (α-DNA), L-DNA (mirror image DNA), 2′-5′ linked RNA, branched DNA/RNA or chimeras of natural DNA or RNA and the above-modified nucleic acids. For the purposes of the present invention, any nucleic acid containing a “nucleotide analogue” shall be considered as a nucleic acid analogue. Backbone replaced nucleic acid analogues can also be adapted to for use as immobilised selective moieties of the present invention. For purposes of the present invention, the peptide nucleic acids (PNAs) (Nielsen et al, 1993, Anti-Cancer Drug Design, 8: 53; Engels et al., 1992, Angew, Chem. Int. Ed. Eng., 31: 1008) and carbamate-bridged morpholino-type oligonucleotide analogs (Burger, D. R., 1993, J. Clinical Immunoassay, 16: 224; Uhlmann, et al., 1993, Methods in Molecular Biology, 20, “Protocols for Oligonucleotides and Analogs,” ed. Sudhir Agarwal, Humana Press, NJ, U.S.A., pp. 335-389) are also embraced by the term “nucleic acid analogues”. Both exhibit sequence-specific binding to DNA with the resulting duplexes being more thermally stable than the natural DNA/DNA duplex. Other backbone-replaced nucleic acids are well known to those skilled in the art and may also be used in the present invention (See e.g., Uhlmann et al 1993, Methods in Molecular Biology, 20, “Protocols for Oligonucleotides and Analogs,” ed. Sudhir Agrawal, Humana Press, NJ, U.S.A., pp. 335).
The term “PTP” refers to post-transfusion purpura.
The term “PTPR” refers to post-transfusion platelet refractorines.
“SNP” refers to single nucleotide polymorphism.
The standard, one-letter codes “A,” “C,” “G,” and “T” are used herein for the nucleotides adenylate, cytidylate, guanylate, and thymidylate, respectively. The skilled will understand that, in DNAs, the nucleotides are 2′-deoxyribonucleotide-5′-phosphates (or, at the 5′-end, possibly triphosphates) while, in RNAs, the nucleotides are ribonucleotide-5′-phosphates (or, at the 5′-end, possibly triphosphates) and uridylate (U) occurs in place of T. “N” means any one of the four nucleotides. On occasion herein, dA, dC, dG and dT might be used for the respective 2′-deoxyribonucleotides.
Unless otherwise specified or required by the context, “nucleic acid” means DNA or RNA and “nucleotide” means ribonucleotide or 2′-deoxyribonucleotide.
Reference herein to a “full-length” CD109 molecule or protein means the 1445-amino acid-long polypeptide, for which the amino acid sequence, deduced from a cDNA sequence, is provided in SEQ ID NO:1 and in SEQ ID NO:3 and which is denoted as the full-length translated product (i.e., including the amino-terminal leader peptide, and excluding carboxyl-terminal processing associated with GPI anchor addition). The Gov a alloantigen bearing form of CD109 may be referred to herein as 703 Tyr CD109. The Gov b alloantigen bearing form of CD109 may be referred to herein as 703 Ser CD109.
It has been determined that a single nucleotide of the CD109 gene is responsible for the Gov polymorphism in CD109. Extensive serological studies initially demonstrated that the polymorphism underlying the Gov system resides solely on the CD109 molecule [Sutherland, D. R. (1991); Smith et al. (1995)]. Further, extensive deglycosylation of CD109 does not affect the binding the anti-Gov a and anti-Gov b antibodies to molecules of the appropriate phenotype, or to cells bearing the appropriate CD109 variant, indicating that carbohydrate residues are not involved in the formation of Gov antigenic epitopes. Further work has indicated that the Gov allele-specific antibody binding can however, be abrogated by denaturation of CD109 with the detergent SDS [Smith et al. (1995)]. Taken together, these observations indicate that the Gov alleles of CD109 are protein epitopes that are likely defined by the primary amino acid sequence of CD109.
Following the isolation of a CD109 cDNA the nature of the two Gov alleles was characterised further using platelet RNA-derived cDNA in the polymerase chain reaction (“PCR”). Platelet mRNA transcripts were obtained from serologically defined Gov a/a , Gov a/b and Gov b/b individuals. The RNA was then converted to cDNA, and the entire CD109 cDNA coding region was then amplified as a series of overlapping PCR products. The Gov a [SEQ ID NO:1] and Gov b [SEQ ID NO:3] alleles differ by an A to C substitution at position 2108 of the coding region of the CD109 cDNA. This single nucleotide polymorphism also results in a BstNI restriction site in the Gov b allele that is not present in its Gov a counterpart. On the basis of this BstNI site, Gov a can by distinguished from Gov b by restriction fragment length polymorphism (RFLP) analysis. This single nucleotide polymorphism can also be detected by SSCP analysis, and by allele-specific hybridization studies, including “Real-Time” PCR analyses.
As a result of this A 2108 C single nucleotide polymorphism, the Gov a allele [SEQ ID NO:2] of CD109 contains a Tyr at position 703 of the full-length protein, while the Gov b allele [SEQ ID NO:4] contains a Ser in this position. The polymorphism does not alter the ability of Gov a and Gov b homozygous platelets to adhere to collagen types I, III and V. Additionally, the binding of anti-Gov a and anti-Gov b antibodies to platelets of the appropriate phenotype did not interfere with platelet adhesion to any of the above collagen types. Thus, while the Tyr 703 Ser results in the formation of the Gov alloantigen epitopes, it does not appear to impair platelet function.
Identification and characterisation of the Gov alloantigen system permits pre- and post-natal diagnosis of the Gov phenotype of an individual, providing a warning for the possibility of NATP, PTP and PTPR. Allelic Gov typing of CD109 equates with the Gov status of the CD109 protein of an individual. The Gov system led to diagnostic and therapeutic strategies to avoid or control diseases that result from Gov incompatibility. The present invention can be applied to these tasks and goals in a variety of ways, illustrative examples of which are discussed below.
For example, an oligonucleotide probe can be synthesized, in accordance with the present invention, that will hybridize to a cDNA segment, derived from CD109 mRNA, that contains the nucleotide G at polymorphic nucleotide 2108 (nucleotide=guanylate). Alternatively, an oligonucleotide probe can be synthesized that will hybridize with a CD109 cDNA segment containing the base adenine at nucleotide 2108 (nucleotide=adenylate). These allele-specific probes can be appropriately labelled and added to the generated cDNA segments under annealing conditions, such that only one of the allele-specific probes hybridizes and can be detected, thereby identifying the specific Gov a or Gov b allele. In accordance with conventional procedures, the design of an oligonucleotide probe according to the present invention preferably involves adjusting probe length to accommodate hybridization conditions (temperature, ionic strength, exposure time) while assuring allele-specificity. A length of ten to thirty nucleotides is typical.
Diagnostic kits can also be used, in accordance with the present invention, for the determination and diagnosis of alloantigen phenotypes via the procedures described herein. Such a kit can include, among others, antibodies or antibody fragments to an antigenic determinant expressed by either of the above-described Gov a - and Gov b -encoding sequences. These antibodies would react with the blood sample of an individual so as to indicate whether that individual has a Gov a or Gov b phenotype. Alternatively, all the reagents required for the detection of nucleotide(s) that distinguish the Gov alloantigens, by means described herein, can be provided in a single kit that uses isolated genomic DNA, platelet (or other cellular) mRNA or total RNA, or corresponding cDNA from an individual. A kit containing a labelled probe that distinguishes, for example, nucleotide 2108 of CD109 can be utilised for Gov alloantigen genotyping and phenotyping.
A further beneficial use of the nucleotide sequences that distinguish the Gov a allele from the Gov b allele is to obtain or synthesize the respective expression product, in the form of a peptide or polypeptide, encoded by these nucleotide sequences. These polypeptides can be used to generate antibodies for diagnostic and therapeutic uses, for example, with regard to pathological conditions such as PTP, PTPR or NATP. These polypeptides can also be used diagnostically to detect the presence of Gov a or Gov b specific antibodies in patient plasma or serum, or used therapeutically (see below; assays may be adopted, for example, from U.S. Pat. No. 5,851,788).
A polypeptide within the present invention which can be used for the purpose of generating such antibodies preferably comprises an amino-acid sequence that corresponds to (i.e., is coincident with or functionally equivalent to) a fragment of the CD109 molecule that includes amino acid 703. When amino acid 703 is Tyrosine, the polypeptide can be used, as described above, to produce antibodies that specifically bind the Gov a form of CD109; in contrast, when it is Serine, antibodies can be obtained that specifically recognise the Gov b form. The class of polypeptides thus defined, in accordance with the present invention, is not intended to include the native CD109 molecule, but does encompass fragments of the molecule, as well as synthetic polypeptides meeting the aforementioned definition.
Although the length of a polypeptide within this class is not critical, the requirement for immunogenicity may require that the polypeptide be attached to an immunogenicity-imparting carrier. Such carriers include a particulate carrier such as a liposome or a soluble macromolecule (protein or polysaccharide) with a molecular weight in the range of about 10,000 to 1,000,000 Daltons Additionally, it may be desirable to administer the polypeptide with an adjuvant, such as complete Freund's adjuvant. For artificial polypeptides, as distinguished from CD109 fragments, maximum length is determined largely by the limits of techniques available for peptide synthesis, which are currently about fifty amino acids. Thus, a synthetic polypeptide of the present invention is preferably between four to about fifty amino acids in length.
In the context of the present invention, the term “antibody” encompasses monoclonal and polyclonal antibodies produced by any available means. Such antibodies can belong to any antibody class (IgG, IgM, IgA, etc.) and may be chimeric. Examples of the preparation and uses of polyclonal antibodies are disclosed in U.S. Pat. Nos. 5,512,282, 4,828,985, 5,225,331 and 5,124,147 which are incorporated by reference in their entirety. The term “antibody” also encompasses antibody fragments, such as Fab and F(ab′) 2 fragments, of anti-Gov a or anti-Gov b antibodies, conjugates of such fragments, and so-called “antigen binding proteins” (single-chain antibodies) which are based on anti-Gov a or anti-Gov b antibodies, in accordance, for example, with U.S. Pat. No. 4,704,692, the contents of which are hereby incorporated by reference. Alternatively, monoclonal antibodies or fragments thereof within the present invention can be produced using conventional procedures via the expression of isolated DNA that encodes variable regions of such a monoclonal antibody in host cells such as E. coli (see, e.g., Ward et al., Nature, 341:544-546 (1989)) or transfected murine myeloma cells (see Gillies et al., Biotechnol. 7:799-804 (1989); Nakatani et al., Biotechnol. 7:805-810 (1989)). For additional examples of methods of the preparation and uses of monoclonal antibodies, see U.S. Pat. Nos. 5,688,681, 5,688,657, 5,683,693, 5,667,781, 5,665,356, 5,591,628, 5,510,241, 5,503,987, 5,501,988, 5,500,345 and 5,496,705 that are incorporated by reference in their entirety.
While human alloantisera currently used for serological typing are specifically excluded from this definition, the use of CD109 or Gov allele-specific peptides to detect anti-Gov antibodies in human plasma or serum, or to determine the specificity of such alloantibodies, are specifically included. Similarly, the use of such CD109 peptides or Gov allele-specific peptides to purify CD109 antibodies, or allele-specific CD109 antibodies from human serum is specifically included. Similarly, the use in vitro of such CD109 peptides or Gov allele-specific peptides to deplete allele-specific antibody activity from human serum samples, or to block CD109 antibody binding, or allele-specific antibody binding, is specifically included.
Diagnostic applications of these antibodies are exemplified, according to the present invention, by the use of a kit containing an anti-Gov a or an anti-Gov b antibody, which undergoes a reaction with a sample of an individual's blood to determine a Gov a or Gov b platelet phenotype. Such a reaction involves the binding of anti-Gov a antibody to Gov a antigen or the binding of anti-Gov b antibody to Gov b antigen. The observation of antibody-antigen complex in a blood sample would indicate a positive result. A kit of this type could be used to diagnose, or to help prevent the occurrence of pathological conditions like PTP, PTPR, or NATP.
A polypeptide of the present invention that is recognised specifically by anti-Gov a or anti-Gov b antibodies can also be used therapeutically. Thus, antibodies raised against such a polypeptide can be employed in the generation, via conventional methods, of anti-idiotypic antibodies, that is, antibodies that bind an anti-Gov a or anti-Gov b antibody. See, e.g., U.S. Pat. No. 4,699,880, the contents of which are hereby incorporated by reference. Such anti-idiotypic antibodies would bind endogenous or foreign anti-Gov antibodies in the blood of an individual, which would treat or prevent pathological conditions associated with an immune response to a “foreign” Gov alloantigen. Alternatively, a polypeptide within the present invention can be administered to an individual, with a physiologically-compatible carrier, to achieve the same qualitative effect, namely, the selective reduction or elimination of circulating anti-Gov antibodies from a patient suffering or at risk from an immune response, or the abrogation by competitive binding to administered peptide, of the binding of Gov-specific antibodies to the platelets of such an individual
The present invention is further described below by reference to the following, illustrative examples.
Example 1
PCR Amplification and Analysis of PCR Products
Platelet total RNA was isolated from EDTA anticoagulated blood of Gov aa and Gov bb individuals in the manner described in Lymann et al., Blood 75:2343-48 (1990). First, platelet mRNA in 10 μl aliquots was heated to 70° C. for 10 minutes and quickly cooled on ice before reverse transcription. The first strand cDNA was then synthesized using 10 μM oligo dT, 40 units RNAsin (Promega), 2 mM of each dNTP (dN triphosphate) (Pharmacia), 500 units of cloned MMLV reverse transcriptase and 5× enzyme buffer (Gibco) in a total volume of 50 μl. The cDNA synthesis was carried out at 42° C. for 45 minutes and was stopped by chilling to 0° C.
Overlapping sets of oligonucleotide primers (Table 2) based on the sequence of CD109 were then used to amplify by PCR the entire coding region of platelet CD109 in 8 overlapping segments that spanned the entire CD109 open reading frame.
TABLE 2
Annealing
Size
Temperature
Fragment
Sense Primer
Antisense Primer
(bp)
(° C.)
1
K1-80
(−24)
K1-650
544
568
59
5′ GTAGCCCAGGCAGACGCC 3′
5′ GTGACAACCACTGTTGGATCAA 3′
(SEQ ID NO: 15)
(SEQ ID NO: 23)
2
K1-1
445
K1-1120
1014
570
50
5′ CGCATTGTTACACTCTTCTC 3′
5′ TACATTTCTTGAAATACCTG 3′
(SEQ ID NO: 16)
(SEQ ID NO: 24)
3
K1-1022
910
K1-REV-1
1747
838
50
5′ GATTCTTCAAATGGACTTT 3′
5′ GGCTGTGTCACAGAGATC 3′
(SEQ ID NO: 17)
(SEQ ID NO: 25)
4
K1-1400
1291
GSP3
2165
875
55
5′ TGAATTCCCAATCCTGGAGGA 3′
5′ GCCACCCAAGAAGTGATAGA 3′
(SEQ ID NO: 18)
(SEQ ID NO: 26)
5
K1-M43
1898
6R4N
2998
1101
56
5′ TTCAGGAATGTGGACTCTGG 3′
5′ CGGCTTCAAGGAAACATCT 3′
(SEQ ID NO: 19)
(SEQ ID NO: 27)
6
K1-3080
2948
1-5N
3859
912
56
5′ CTGGGAGCACTTGGTTGTCA 3′
5′ CAGCAACATCTAAATCAAAGGC 3′
(SEQ ID NO: 20)
(SEQ ID NO: 28)
7
K1-3570
3462
7U3N
4337
876
50
5′ ACAATTTCAGACTTCTGAGG 3′
5′ CACAGCCAAAGTTCCATA 3′
(SEQ ID NO: 21)
(SEQ ID NO: 29)
8
K1-3920
3812
K1-4600
4489
678
55
5′ GACGAAGATCTATCCAAAATC 3′
5′ GCTAGGACCTGTTGTACACC 3′
(SEQ ID NO: 22)
(SEQ ID NO: 30)
Table 2 lists the position of the 5′ end of each oligonucleotide with respect to the CD109 cDNA sequence, which includes both 3′ and 5′ untranslated regions, is noted in parentheses. The CD109 ORF encompasses nucleotides 1-4335 of the published CD109 cDNA, and corresponds exactly to the CD109 cDNA sequence presented in SEQ ID NO:1. The size of each PCR product, and the annealing temperature used for the corresponding primer pair, is listed.
PCR reactions (50:1) containing 1×PCR buffer (Gibco Life Technologies), 1.5 mM MgCl 2 , 200:M of each dNTP, 1:M of each primer, 1.25 units Taq polymerase (Gibco Life Technologies), and 3:1 cDNA underwent 40 cycles of 94° C. (45 seconds), primer-specific annealing temperature (Table 2; 45 seconds), and 72° C. (45-60 seconds), using a Perkin Elmer 2400 thermocycler. PCR products (30:1) were subsequently size-separated electrophoretically on a 1.2% agarose/TAE gel containing 1:g/ml ethidium bromide. Bands were subsequently excised and purified (50:1) using the QIAquick (Qiagen) kit for direct sequencing and subcloning. Sequencing reactions (3-5:I purified product per reaction) were carried out using the Thermosequenase Cy5.5 dye terminator sequencing kit (Amersham Pharmacia Biotech) and the same primers that had been used for initial PCR amplification (Table 2), or selected internal CD109-specific primers as appropriate, and were subsequently analysed using the Open Gene automated DNA sequencing system (Visible Genetics). In parallel, PCR products were cloned into Pmel-digested pMAB1, a pBS SK(−) (Stratagene) derivative containing a Pmel restriction site within the polylinker. Resultant plasmid clones were analysed by alkaline lysis/restriction digestion, and as appropriate (and following an additional overnight 13% PEG/1.6 M NaCl precipitation), by DNA sequence analysis as above. By combining direct PCR sequencing and the analysis of subcloned fragments, it was ensured that the DNA sequence of each PCR-derived cDNA fragment was obtained independently at least twice, with each fragment being sequenced in both directions in its entirety.
This analysis revealed that the CD109 cDNA sequences of Gov aa and Gov bb individuals differed by a single nucleotide at position 2108 of the sequence shown in SEQ ID NO:1. Gov a/a
individuals have an A at position 2108, whereas Gov b/b individuals have a C at the same position. This change results in a Tyr-Ser amino acid polymorphism at residue 703 of the full-length CD109 polypeptide chain. This single nucleotide polymorphism also results in a BstNI restriction site in the Govb allele that is not present in the Gov a allele. Analysis of the other regions of the CD109 cDNA in their entirety revealed no other nucleotide differences that segregated with Gov phenotype (i.e., that could be used to distinguish the Gov a allele from the Gov b allele).
To facilitate subsequent genomic DNA analyses of the Gov a/b alleles, the intron/exon junctions of the exon bearing the putative Gov-specific nucleotide substitution identified above, as well as the DNA sequence of the flanking introns, were determined. CD109 cDNA-specific oligonucleotides binding in the vicinity of this substitution were used for the direct sequencing of p4L10, a pCYPAC — 1-derived PAC clone bearing the human CD109 locus using the Open Gene system (Visible Genetics) as above. The nucleotide sequence of the Gov polymorphism-containing exon, as well as of the flanking introns, is presented in SEQ ID NO:5. The Gov polymorphism lies at nucleotide position 954 in SEQ ID NO:5. Subsequent work has mapped the intron-exon structure of the entire human CD109 locus, and has determined that the Gov single nucleotide polymorphism of CD109 lies in exon 19 of the CD109 gene.
Example 2
RFLP Analysis of PCR Amplified Genomic DNA
The A-C Gov CD109 polymorphism corresponds to the internal nucleotide of the first complete codon of exon 19 of the CD109 gene. As this exon comprises only 118 nucleotides, and the Gov polymorphism lies almost at the extreme 5′ end of this exon, we determined the nucleotide sequence of both introns flanking this exon to facilitate subsequent genomic DNA analyses of the Gov a/b alleles. The DNA sequence of CD109 exon 19 and its flanking introns (CD109 introns 18 and 19) is presented as SEQ ID NO:5. To confirm that the A to C polymorphism at position 2108 of the CD109 open reading frame (nucleotide 2108, SEQ ID NO: 1; nucleotide 954, SEQ ID NO:5) segregates with the Gov phenotype, RFLP analysis was carried out on PCR amplified genomic CD109 DNA using the BstNI restriction endonuclease, which recognises the DNA sequence 5′ CCAGG 3′ found in the Gov b cDNA (nucleotides position 2108-2112 in SEQ ID NO:3; the corresponding Gov a sequence, 5′ ACAGG 3′, is nucleotides 2108-2112 in SEQ ID NO:1). This enzyme does not cleave at 5′ ACAGG 3′ (found in Gov a ; nucleotides 2108-2112 in SEQ ID NO: 1). A 448 bp genomic fragment was PCR-amplified from Gov aa , Gov ab , and Gov bb individuals using the pair of oligonucleotides SEQ ID NO:9 and SEQ ID NO:10. These oligonucleotides flank exon 19. The former binds within intron 18 (nucleotides 875-892 SEQ ID NO:5), while the latter binds within intron 19 to the sequence complementary to nucleotides 1305-1322 of SEQ ID NO:5). The resultant 448 bp PCR product, when digested with BstNI, yielded the restriction fragments predicted on the basis that the A to C polymorphism at position 2108 (SEQ ID NO: 1) segregates with the Gov phenotype.
Example 3
Hybridization Analysis of PCR Amplified Genomic DNA
To further confirm that the A to C polymorphism at position 2108 of the CD109 open reading frame (nucleotide 2108, SEQ ID NO:1; nucleotide 954, SEQ ID NO:5) segregates with the Gov phenotype, we also performed an alternative analysis involving the selective hybridization of Gov allele-specific DNA probes to PCR amplified genomic CD109 DNA. Two primers flanking the polymorphic A-C site at position 2108 (SEQ ID NO:1; position 954, SEQ ID NO:5) were designed to amplify by PCR a 105 bp genomic DNA fragment containing the polymorphic site from genomic DNA isolated from Gov aa , Gov ab , and Gov bb individuals. The first primer (SEQ ID NO:11) binds within intron 18 to nucleotides 902-928 of SEQ ID NO:5. The second primer (SEQ ID NO:12) binds within exon 19 to the sequence complementary to nucleotides 977-1106 of SEQ ID NO:5. Two additional nucleotide probes were designed—one specific for the target sequence of the Gov a allele of the CD109 gene, and the other for the Gov b allele of the CD109 gene. The first probe (SEQ ID NO:13) overlaps the CD109 intron 18/exon 19 junction, binds to the Gov a allele at nucleotides 935-974 of SEQ ID NO:5, and was tagged with the fluorescent dye 6-FAM. The second probe (SEQ ID NO:14), also overlapping the CD109 intron 18/exon 19 junction, binds to the Gov b allele at the position corresponding to nucleotides 935-971 of SEQ ID NO:5, and was tagged with the fluorescent dye VIC. Genomic DNA was isolated from Gov phenotyped human peripheral blood leukocytes, and PCR/hybridization analysis was carried out using Taqman real-time PCR technology (Perkin Elmer). Genomic DNA was amplified using primers SEQ ID NO:11 and SEQ ID NO:12, with each reaction additionally containing 100 nM FAM-labelled Gov a probe and 200 nM VIC-labelled Gov b probe. Allelic discrimination, based on allele-specific fluorescence, was then determined using a post-PCR plate reader (Perkin Elmer). In all cases, PCR/fluorescence-based Gov genotyping correlated with the Gov phenotype, indicating that the A to C polymorphism at position 2108 (SEQ ID NO: 1) does indeed segregate with the Gov phenotype.
Example 4
SSP Analysis of PCR Amplified Genomic DNA
To further confirm that the A to C polymorphism at position 2108 of the CD109 open reading frame (nucleotide 2108, SEQ ID NO:1; nucleotide 954, SEQ ID NO:5) segregates with the Gov phenotype, we also performed an alternative analysis involving SSCP analysis of PCR amplified genomic CD109 DNA. Two Gov allele-specific antisense oligonucleotides—SEQ ID NO:6 and SEQ ID NO:7—differing by a single 3′ nucleotide (and binding to sequence complementary to nucleotides 954-976 of SEQ ID NO:5, and of the Gov b counterpart of SEQ ID NO:5, respectively), were combined with a common sense primer—SEQ ID NO:8 binds within intron 18 and which corresponds to nucleotides 752-773 of SEQ ID NO:5, to amplify a 225 bp genomic DNA fragment containing the Gov polymorphic site from genomic DNA isolated from Gov aa , Gov ab , and Gov bb individuals. In all cases, complete concordance between PCR-SSP analysis and Gov phenotyping was observed.
SEQUENCES
SEQ ID NO: 1 consists of the entire 4335 nucleotide CD109 cDNA open reading frame encoding the Gov a allele. The Gov a allele comprises an A at nucleotide position 2108.
SEQ ID NO:2 consists of the entire 1445 aa protein sequence produced from CD109 Gov a cDNA. The Gov a allele comprises a Tyr at amino acid 703.
SEQ ID NO: 3 consists of the entire 4335 nucleotide CD109 cDNA open reading frame encoding the Gov b allele. The Gov b allele comprises a C at nucleotide position 2108.
SEQ ID NO: 4 consists of the entire 1445 aa protein sequence produced from the CD109 Gov b cDNA. The Gov b allele comprises a Ser at amino acid 703.
SEQ ID NO: 5 consists of the CD109 genomic DNA comprising CD109 exon 19 and the flanking introns, introns 18 and 19. The 118 nucleotide exon 19, comprising nucleotides 952-1069 of SEQ ID NO:5, corresponds to nucleotides 2106-2223 of SEQ ID NO: 1. The A to C Gov polymorphism of CD109 (corresponding to nucleotide 2108 of SEQ ID NO: 1) therefore corresponds to nucleotide 954 of SEQ ID NO:5. In the Gov a allele, nucleotide 954 is A, while in the Gov b allele nucleotide 954 is C. Thus, SEQ ID NO:5 corresponds to the Gov a allele of CD109. Within SEQ ID NO:5, nucleotides 1-951 correspond to CD109 intron 18, while nucleotides 1070-2608 correspond to intron 19.
We note that nucleotides 2108-2112 of SEQ ID NO: 1, and the corresponding nucleotides 954-958 of SEQ ID NO:5, which consist of the sequence 5′ ACAGG 3′ (and which contains the Gov a allele-specific polymorphic nucleotide at its 5′ end), is not cleavable by the restriction endonuclease BstNI. However, in the corresponding Gov b allele, the corresponding sequence—5′ CCAGG 3′—is cleavable by BstNI, and that the two Gov alleles can be discriminated on this basis. We note also that a group of restriction endonucleases—Bst2UI, BstNI, BstOI, EcoRII, MaeIII, MspR91, MvaI, or ScrFI (or one of their isoschizomers)—is capable of differentiating between the Gov a and Gov b alleles on this basis.
SEQ ID NO:6-SEQ ID NO:14 comprise oligonucleotides for the PCR amplification of Gov polymorphism containing CD109 sequence from RNA, cDNA derived from RNA, or from genomic DNA, and for the Gov typing analyses of such amplified DNA fragments.
SEQ ID NO:6.
SEQ ID NO: 3, an antisense oligonucleotide specific for the Gov a allele, binds to exon 19 sequence complementary to nucleotides 954-976 of SEQ ID NO:5. SEQ ID NO:6 and SEQ ID NO: 7 (see below) differ by a single allele-specific 3′ nucleotide
SEQ ID NO:7.
SEQ ID NO:7, an antisense oligonucleotide specific for the Gov b allele, binds to exon 19 sequence complementary to nucleotides 954-976 of the Gov b counterpart of SEQ ID NO:5. SEQ ID NO:6 (see above) and SEQ ID NO:7 differ by a single allele-specific 3′ nucleotide.
SEQ ID NO:8.
SEQ ID NO:8 binds within intron 18, and corresponds to nucleotides 752-773 of SEQ ID NO:5.
SEQ ID NO:9.
SEQ ID NO:9 binds within intron 18 (nucleotides 875-892 SEQ ID NO:5).
SEQ ID NO:10.
SEQ ID NO:10 binds within intron 19 to the sequence complementary to nucleotides 1305-1322 of SEQ ID NO:5.
SEQ ID NO:11
SEQ ID NO:11 binds within intron 18 to nucleotides 902-928 of SEQ ID NO:5.
SEQ ID NO:12.
SEQ ID NO:12, binds within exon 19 to the sequence complementary to nucleotides 977-1006 of SEQ ID NO:5.
SEQ ID NO:13.
SEQ ID NO:13, specific for the Gov a allele, overlaps the CD109 intron 18/exon 19 junction, and binds to the Gov a allele at nucleotides 935-974 of SEQ ID NO:5.
SEQ ID NO:14.
SEQ ID NO:14, specific for the Gov b allele, overlaps the CD109 intron 18/exon 19 junction, and binds to the Gov b allele at the position corresponding to nucleotides 935-971 of SEQ ID NO:5. | Based on the discovery of the nucleotide and amino acid differences which distinguish the Gov a and Gov b allelic forms of the membrane glycoprotein CD109, and which comprise the biallelic Gov platelet alloantigen system, compositions and methods are provided for determining the Gov genotype and phenotype of individuals. Also provided, on the basis of this discovery, are compositions and methods for treating disorders associated with Gov alloantigen incompatibility, such as the bleeding disorders post-transfusion purpura, post-transfusion platelet refractoriness, and neonatal alloimmune thrombocytopenia. The two allelic forms of CD109 differ by a single amino acid. The Gov a allelic form has Tyr at amino acid position 703 in the CD109 sequence. The Gov b allelic form has Ser at the same position. This amino acid difference is due to a single change, from A for the Gov a allele to C for the Gov b allele, in the CD109 gene. | 2 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to a semiconductor package, and more particularly to an inner lead bonding apparatus comprising a heat dissipation means for preventing heat from being transferred to the tape automated bonding tape during inner lead bonding process, and to a method for inner lead bonding using such an inner lead bonding apparatus.
2. Description of the Prior Art
Tape automated bonding thereinafter "TAB" which was introduced by General Electric Co. in 1960's is one of automated technologies for packaging a plurality of semiconductor devices in place of wire bonding technology. As TAB technology develops and the reliability of TAB increases, the application of TAB packages are gradually broadened to the fields requiring more stable and more excellent electrical properties such as Very High Speed ICs, Liquid Crystal Displays, Super Computers or and the like.
TAB process begins with the step of bonding, by using a thermo-compression bonding technique, a silicon chip to a patterned metal, for example, a copper pattern formed on a polymer tape (e.g., polyimide tape). Generally the tape used in TAB comprises an adhesive layer made of various adhesive materials including polyimides, epoxies, acrylics and phenolic-butyrals. The choice of an adhesive should be made based, with first priority, on its thermal stability, because a TAB package will be challenged during elevated temperature processes such as Inner Lead Bonding (here-in-after, referred to as `ILB`), encapsulation-curing, burn-in testing and outer lead bonding. In particular, an ILB process in which patterned inner leads are bonded to bumps formed on bonding pads of the semiconductor chips is carried out under a condition of 530°-550° C. in order to increase the pull strength of the junction interface between inner leads and the bumps. The ILB process is typically accomplished by either a single point bonding method or a gang bonding method. The gang bonding, method which is disclosed in U.S. Pat. No. 3,763,404 and U.S. Pat. No. 4,051,508, is widely used in mass production of TAB packages in a short processing cycle since TAB beam leads can be bonded simultaneously by methods including thermo-compression bonding, dynamic alloy formation, solder reflow, and the like.
FIG. 1 shows a prior art TAB package during ILB process is running. Referring to this Figure, inner leads 1 formed in a predetermined pattern by, for example, photolithography is attached by an adhesive 2 to a polymer (e.g., polyimide) layer 3 to form a three-layered tape. On the chip bonding pads 7 of a semiconductor device 8 are formed bumps 6 for electrical interconnection with the inner leads 1. In ILB, a plurality of semiconductor chips 8 are automatically pre-aligned by an xy-coordinate table (not shown) with reference to a bonding machine 5 such as a thermode. A supporting means or clamp 4 is used to fasten a lead frame of TAB, and the position of the former is preset, optimized so as to secure a stable fixation of the TAB leads. During the ILB process, a chip carrier (not shown) rises to the bond level, and the bonding machine 5 drops to apply heat and pressure through metallic leads 1 on the tape to the bumps 6 on the chip 8. At this time, the heat conducted to the adhesive 2 of the lead frame from the bonding machine 5 is likely cause a so called degradation phenomenon in which the thermally fragile adhesive is melted down. Even if this does not occur, high stress is inevitably put on the interface of the adhesive, which and the leads, because the adhesive expanded during ILB process contracts after ILB is finished. This kind of stress can be also applied to the junction point between the inner leads 1 and the bumps 6 because of the difference in their thermal expansion coefficients. This will result in breaking-off the ILB junction interface which will, in turn, cause critical electrical failures of the device.
The dwell time taken by the thermode 5 in thermo-compressing the leads just lying on the bumps, and the temperature of the thermode 5 have a very important influence upon the bonding strength of the ILB junction interface. This strength will be apparently increased in proportion to the temperature and the dwell time. However, the problems of stress, breaking-off of the interface and the melting down of the adhesive as described above will be likewise made more severe. Accordingly, a compromise of the two factors must be made.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide an inner lead bonding apparatus which can overcome the disadvantages caused by the thermal problems, and to provide a method for inner lead bonding using such an apparatus. It is another object of this invention to eliminate the limits of the temperature of the bonding machine and the dwell time, as well as to prevent degradation occurring near the adhesive, and to obtain high bonding performance of the inner leads to the bumps.
According to one aspect of the present invention, an apparatus for bonding bumps formed on bonding pads of a semiconductor chip to inner leads of patterned metal formed on a polymer tape by, for example, photo-lithography technology comprises a thermo-compressing means for providing heat and pressure to the bumps and an area of the each inner lead which will be directly bonded to the upper surfaces of the bumps, a supporting means for upholding the inner leads, and a heat dissipation means attached to the supporting means and to the inner leads near the area directly bonded to the bumps.
According to another aspect of the present invention, the heat dissipation means is coupled to the supporting means by screws and bolt holes, wherein the bolt holes are formed in the heat dissipation means and the transverse dimension of each of bolt hole is longer at one direction so that the position of the heat dissipation means can be adjusted to accommodate several kinds of differently sized TAB packages.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional view of the a TAB package which is subjected to an ILB process by using a conventional bonding machine.
FIG. 2A is a partial cross-sectional view of a TAB package which is subjected to an ILB process by using a bonding machine according to the present invention.
FIG. 2B is a plan view of a heat dissipation plate attached by a screw and a bolt hole to a clamp of the bonding machine according to the present invention.
FIG. 2C is a front view of the heat dissipation plate attached by the screw and the bolt hole to the clamp of the bonding machine according to the present invention.
FIG. 3 shows a simulation result for understanding of heat dissipation and heat conduction in plan view when a TAB-ILB process is accomplished using the ILB machine according to the present invention.
FIG. 4 shows a simulation result for understanding of heat dissipation and heat conduction in plan view when the TAB-ILB process is accomplished with using the conventional ILB machine.
FIG. 5 is an enlarged detail view of a portion around the bumps of FIG. 3.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The TAB-ILB process according to the present invention will be explained, with reference to FIG. 2A where the same constructional elements are denoted with the same reference numerals and detailed description thereof will not be given. Referring to the FIG. 2A, between the upper surface of a clamp 4 and inner leads 1 is mechanically connected heat dissipation plate L made of materials having good heat conductivity. As a material of the heat dissipation plate L, copper, copper alloy or alloy 42 (Nickel 42% and Fe 58%) may be used, or copper alloy or alloy 42 coated with diamond by a chemical vapor deposition method can be also used. Alternatively, the heat dissipation plate can be formed of a copper thin foil-clad alloy 42, in order to enhance the heat conductivity of the plate L while keeping the mechanical strength of the alloy 42.
Because the bonding machine 5 is constructed as shown in FIG. 2, the heat emanated from the machine 5 can be drawn out via the heat dissipation plate L which is contacted to the inner leads 1 at approximately the center position A of the inner leads between the region C proximate to the clamp 4 and the region B receiving heat directly from the bonding machine 5. As a result, heat conducted to the inner leads 1 from the bonding machine 5 is seldom transferred to the region C. And heat flux transferred to the leads by radiation or mostly convection is blocked by the plate L. It should be noted at this time that the heat dissipation plate L plays two roles, namely one of intercepting the conduction of heat, and another blocking the heat flux.
From the above description, it can be easily understood that the degradation phenomenon, in which the adhesive 2 peels out from the inner leads 1 at the position A can be prevented, as can electrical failure caused by the difference of the coefficients of thermal expansion of the inner leads 1 and the bumps 6, since temperature of the inner leads can be lowered. FIG. 2B is a plan view showing the structure of the heat dissipation plate L fixed to the clamp 4. A nut hole 11 which is shaped as a flat ellipse on the heat dissipation plate L is coupled to the clamp 4 by the fixing means 10. The elliptical nut hole 11 is for positioning of the heat dissipation plate L, and makes it possible for the heat dissipation fin of the present invention to be applied to different kinds of TAB packages without any additional treatments to determine which position of the heat dissipation plate to contact with the inner leads is most appropriate.
FIG. 2C is a front view of the heat dissipation plate L attached by the fixing means 10 and a bolt hole to the clamp 4 of the bonding machine according to the present invention. The fixing means 10 is, e.g., a screw and serves to mechanically fasten the heat dissipation plate L and the clamp 4.
In order to verify the effect of the heat dissipation plate of the present invention, the inventors have carried out a heat interpretation simulation by a well known Finite Volume Method (FVM). The FVM is suitable to interpret heat dissipation when heat transfers by conduction, convection and radiation are combined, and is evolved from the FDM (Finite Difference Method) obtaining solutions of the heat transfer equations by replacing the differential equations with finite differences.
FIG. 4 shows a simulation result of heat dissipation and heat transfer in plan view when the TAB-ILB process is accomplished with the conventional ILB machine. From this Figure, it can be seen that heat of the bonding machine is transferred to the lead and the adhesive.
FIG. 3 shows a simulation result of heat dissipation and heat transfer in plan view when the TAB-ILB process is accomplished with the ILB machine according to the present invention. Referring to this Figure, the conduction of heat from the bonding machine to the adhesive is intercepted by virtue of the heat blocking action of the heat dissipation plate. In addition to this, the convection of heat from the bonding machine to the leads is also considerably cut off.
FIG. 5 is an enlarged detail view of FIG. 3 for more explicitly showing the geographical distribution of heat in the bonding interface region of the lead frame and the bumps of the chip and in the region around the adhesive.
From the simulation results, the temperature around the adhesive is evidently lowered by about 30% by applying the heat dissipation plate to the conventional bonding machine. In conclusion, by applying the heat dissipation means of the present invention to the conventional inner lead bonding machine, the degradation phenomenon of the adhesive can be prevented, and the more elevated temperature and longer dwell time, which are requisites for increasing the number of TAB leads, can be applied to a TAB package in order to guarantee the reliability a multi-lead TAB package. Further, so called chip cratering which may occur in a TAB-ILB process can be reduced due to the fact that the amount of heat transferred from the hot bonding machine to the chip be decreased (i.e., the gradient of temperature from the bonding machine to the chip becomes lower). In other words, a chip is more likely to be damaged and crushed to craters in direct proportion to the temperature gradient, because the hotter the bonding machine the more stress will be built up in the chip.
Although the present invention is described with reference to the accompanying drawings, this is only for explanation and other embodiments can be practiced in still other ways without departing from the spirit or essential character thereof. For instance, even though the description hereinabove is given of a semiconductor chip having bumps on its electrode bonding pads, a bumped leaded TAB having the bumps formed on the inner leads may alternately be applied to the heat dissipation plate of the present invention. | An inner lead bonding apparatus having a heat dissipation plate attached to inner leads and to a support for upholding a lead frame of a tape automated bonding package. The heat dissipation plate is, during performance of an inner lead bonding process, located near the bonding interface of bumps formed on a semiconductor chip or on the inner leads and the inner leads, and includes a fastener for fixing itself to the support and elliptical bolt holes for enabling its contact position to the inner leads to be controllable. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent application Ser. No. 13/049,979, filed Mar. 17, 2011, pending, which is a divisional of U.S. patent application Ser. No. 11/376,839, filed Mar. 16, 2006, abandoned, which claimed priority to German Patent Application 10 2005 013 685.0, filed Mar. 18, 2005, all of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The invention concerns a tape magazine for a hand-held device for examining a body fluid comprising a test tape, a storage unit for unused test tape and a waste unit for used test tape where the waste unit is driven in order to wind forward the test tape.
BACKGROUND
[0003] In such tape magazines an unused section of test tape is pulled from a supply reel and guided over a receiving device where it takes up a sample of body fluid. Afterwards the section of test tape which is now used is wound onto a waste reel. A detection device which measures the sample and transfers the result of the measurement to an evaluation device is attached to the receiving unit.
[0004] Such tape magazines are preferably used in blood sugar measuring instruments for diabetics who depend on a continuous monitoring of their blood sugar values. The test tape allows a blood sugar test to be carried out inside the instrument after applying capillary blood for example from a finger pad. For this purpose a plurality of test sections or test fields are arranged consecutively on the test tape. An unused section of tape is moved into an active position by advancing the tape. Then the capillary blood is applied and analyzed. In order to simply dose very small amounts of blood and to position the test tape as exactly as possible relative to the detection device, the test tape is guided over a deflecting head inside the instrument. In this process there is a risk of erroneous measurements if the test tape slips off the deflecting head. For a successful measurement the test tape must remain at a well-defined position and rest against it evenly while maintaining a predetermined distance to the detection unit. This is necessary for at least as long as it takes to complete the measurement. Another challenge is that the test tape is very sensitive to contamination. Hence the unused area of the test tape should be spatially separated from the used area and also be screened from external influences which could impair the function of the test tape. Hence a direct drive coupling between the storage unit and the waste unit is very difficult.
[0005] Furthermore the hand-held devices of the prior art are designed for continuous use whereas the tape magazine is replaced. The hand-held devices are therefore relatively large and quite laborious to manufacture not least due to the complicated instrument technology.
SUMMARY
[0006] Hence an embodiment of the present invention is formed to provide a tape magazine which prevents malfunctioning due to slack tape.
[0007] An embodiment of the present invention is further is formed to provide a hand-held device which is compact and has a favorable design for manufacturing.
[0008] The combination of features stated in each of the independent patent claims is proposed. Embodiments and further developments of the invention are derived from the dependent claims.
[0009] The present invention provides a tape magazine apparatus for a hand-held device for analyzing a body fluid. The apparatus comprises a test tape, a storage unit formed for unused test tape, a waste unit formed for used test tape and to be driven in order to move forward the test tape from the storage unit, and an integrated brake that is formed to hold the test tape under tension between the storage and waste units.
[0010] The present invention provides a tape magazine apparatus for analyzing a body fluid. The apparatus comprises a test tape, a reel body for unused test tape and a reel body for used test tape, at least one reel body being driven in order to forward the test tape, and a hand-operated transport mechanism provided as a tape drive.
[0011] The present invention further provides a hand-held device for analyzing a body fluid. The device comprises a tape magazine, an analytical test tape located in the tape magazine, and device electronics based upon integrated polymer circuits.
[0012] Further, the present invention provides a method of dispensing a test tape for an analysis of body fluid. The method comprises providing a test magazine including a test tape, a storage unit formed for unused test tape, a waste unit formed for used test tape and to be driven in order to move forward the test tape from the storage unit, and an integrated brake, applying a brake force with the integrated brake to hold the test tape under tension between the storage and waste units, and actuating the test tape with a tensile force sufficient to move the test tape from the storage unit toward the waste unit.
[0013] Accordingly it is proposed that a brake that holds the test tape under tension is integrated into the tape magazine. This enables the required minimum tape tension to be maintained since the waste unit drive transports the test tape against this tension so that it is not pulled too far away from the storage unit or unintentionally wound off. This allows the test tape to be deflected at a well-defined position relative to the detection unit. In this process the minimum tape tension also prevents unintentional lateral displacement. The tape drive force should in any case be of a sufficient magnitude to overcome the effect of the braking means.
[0014] In particular, a braking force is applied to the storage unit which keeps the test tape under tension. This in particular prevents used test tape from being unintentionally wound off towards the application site. It also prevents areas of the test tape that have already been contaminated with blood from being pulled out of the tape magazine again which is an important hygienic advantage.
[0015] The braking means can exert a braking force directly on the test tape. Alternatively the braking means can act on a reel body for the test tape such that the test tape is indirectly braked. In the latter case no allowance has to be made for changes in the diameter of the tape spool. Furthermore, this does not apply additional mechanical stress to the test tape.
[0016] A simple embodiment provides that the braking means exert a constant braking force on the storage unit. This can be achieved by designing the braking means as a frictional element which in particular have a leaf spring as a frictional element. The braking means are formed by a seal which seals the storage unit at an opening for the test tape.
[0017] In a somewhat more elaborate embodiment the braking means act on the storage unit with a variable braking force. This enables the force required to pull out the test tape to increase to a lesser extent as the diameter of the supply spool decreases compared to the simple embodiment described above. In this connection it should be taken into consideration that the supply spool has a certain bearing friction which has to be overcome by the drive. Accordingly it is necessary to apply a torque which results from the momentary radius of the waste spool and the applied force to reel off the tape from the supply spool. Thus when the radius of the supply spool decreases with time, this force must increase. If the braking force decreases as a function of the tape tension, the overall increase in force can be kept lower.
[0018] An embodiment provides that the braking means have a deflector lever which is loaded with a braking force via a spring where the deflector lever deflects the test tape over a roller. As the tape tensile force decreases the deflector lever is unloaded. The deflector lever can for example be loaded with a leaf spring or pressure spring to exert the braking force and acts as a brake on a spool housing for the test tape.
[0019] Another improvement envisages that the braking force is not only modulated by the tape tension but also by the current spool diameter with the aid of a compensation mechanism so that the tape tension remains almost constant.
[0020] This object can be achieved with a compensation mechanism which has a spring-loaded rocker arm which probes the circumference of the tape spool wherein the spring loading decreases as the diameter of the tape spool decreases and the braking force is correspondingly reduced. Hence the tape tensile force remains constant.
[0021] In another embodiment a recoil locking device or recoil brake which acts in a form-fitting or frictional manner can be provided on the waste unit. If a recoil locking device is used as a locking mechanism, the drive for forwarding the test tape only has to overcome the friction of the storage unit which in particular spares the battery of the drive. This recoil safeguard should not act on the tape drive so that it is also effective when the tape magazine is removed from the hand-held device and prevents used tape from being unintentionally reeled out. The recoil locking device can be designed in a known manner as a safety catch which engages in gear teeth for example in the spool housing of the waste unit in such a manner that a form fit in the reverse direction prevents the waste unit from turning back. The waste unit is then restricted to the “wind on” direction of rotation. However, a frictional locking mechanism can also be provided. Various mechanisms are conceivable for this for example a wrap spring lock or a clamp roller free-wheel.
[0022] The tape magazine has a housing which encloses the test tape, the storage unit and the waste unit. The storage unit should be accommodated in a storage space that is screened from influences that could impair the test tape. This can for example be achieved by a wall of the storage space forming an overlapping area with a wall of the housing with an opening for the test tape being formed along the overlapping area. This opening should be provided with at least one sealing agent or with one sealing means in order to protect the test tape from external influences.
[0023] The present invention also concerns a tape magazine for a test tape in which a hand-operated transport mechanism is provided as a tape drive. An actuating lever is provided for this which engages in an advancing element (e.g. capstan or index wheel) via a feed member, in particular a pawl, in such a manner that the test tape can be moved mechanically. A battery power supply is thus unnecessary. The energy required for the actual measuring process can be generated by the manual actuation and especially by means of an inductive generator or piezo-electrically and for example stored temporarily in a capacitor or high-performance capacitor (supercap). The tape magazine also forms a hand-held device intended as a single-use article, a so-called disposable, which can be discarded after the test tape has been used due to the cost-effective construction.
[0024] The feed mechanism can for example be formed by a ratchet which engages in steps formed in the storage unit and/or waste unit. Such a construction is robust and simple to operate.
[0025] The test tape feed is synchronized by a perforation in such a manner that a test element is ready for a measurement when the lever is actuated at least once so that the measurement can be carried out particularly reliably and with great accuracy. Reference fields can be provided on the tape to further improve the feed accuracy.
[0026] Finally the present invention concerns a hand-held device which is directly formed by a tape mechanism and has instrument electronics, in particular a sensor unit, an evaluation unit and a display unit based on polymer electronics. Such a hand-held device can be constructed to be small and light, can be manufactured cost-effectively and can be used as a disposable unit.
[0027] In particular all disclosed embodiments of tape magazines and hand-held devices can be combined with one another. This applies especially to a hand-held device with electronic components based on polymer electronics combined with a mechanical drive for the test tape.
[0028] The invention is elucidated in more detail in the following on the basis of the embodiment examples shown in a schematic manner in the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 shows a first embodiment example of a tape magazine according to the invention in cross-section.
[0030] FIG. 2 shows a second embodiment example of a tape magazine according to the invention in a side-view in a partial cross-section.
[0031] FIG. 3 shows a third embodiment example of a tape magazine according to the invention in a side-view in a partial cross-section.
[0032] FIG. 4 shows an embodiment example of a mechanically operated tape device in a perspective view with a partially opened housing.
[0033] FIG. 5 shows the device according to FIG. 4 with a closed housing.
DETAILED DESCRIPTION
[0034] FIGS. 1 to 3 show various embodiment examples of a tape magazine according to the invention in which the test tape is held under tensile strain. FIG. 1 shows a tape magazine 10 with a housing 11 . The housing 11 is divided into a first holder 12 for a storage unit 20 and a second holder 13 for a waste unit 24 . The holders 12 , 13 are separated from one another by a dividing wall 14 so that the storage unit 20 is separated from the waste unit 24 . One side wall 12 a, 13 a of each of the holders 12 , 13 overlaps in the area 19 to form an opening 16 which is provided with a seal 17 . The seal 17 can act as a brake, sealing the storage unit 20 at the opening 16 for the test tape 30 . Another opening 15 is provided in the holder 13 for the waste unit 24 . A deflector head 18 for the test tape 30 is integrated into the housing 10 .
[0035] The storage unit 20 has a spool or reel housing 21 which holds an unused test tape 30 which is wound around a spool 22 to form a supply spool 23 . The waste unit 24 is similarly equipped with a spool housing 25 which holds the used test tape wound onto a spool 26 to form a waste spool 27 . The spool 26 is driven by a drive (not shown). The test tape 30 is divided into consecutive test areas. If the drive is actuated, the fresh test tape 30 is wound off the supply spool 23 and guided from the holder 12 through the opening 16 to the deflector head 18 where a single test area comes to rest exposed to the outside and can take up a test liquid such as a drop of blood. The test liquid is measured by a detection unit (not shown). When the drive is actuated again the test tape 30 is transported further. The used test tape 30 passes through the opening 15 into the holder 13 and is wound onto the waste spool 27 .
[0036] An integrated brake is formed to hold the test tape 30 under tension between the storage and waste units 20 , 24 . It is within the scope of the present invention that the brake be formed to apply a force to the storage unit 20 , to exert a direct braking force on the test tape 30 ; to act on a reel body 21 for the test tape 30 such that the test tape is indirectly braked, or to exert a constant braking force on the storage unit 20 . It is further appreciated that it is within the scope of the present invention that the brake is designed as a frictional element.
[0037] It is further appreciated that the brake may be formed to act on the storage unit with a variable braking force in accordance with this disclosure. In such an instance, the variable braking force may depend on the diameter of a tape spool of the storage unit 20 . Alternatively, the variable braking force may depend on the tape tensile force upon movement of the test tape 30 .
[0038] In an embodiment shown in FIG. 1 , the brake is a leaf spring 28 as a frictional element which acts upon the contact point 29 of the spool housing 21 . The spring 28 is provided on an inner wall of the holder 12 for the storage unit 20 . The leaf spring 28 is pretensioned with a constant spring force F spring . Therefore, the test tape 30 has to be reeled off against the corresponding brake torque at a certain tape tensile force F tape . This tape tensile force increases as the radius of the supply spool 23 decreases.
[0039] FIGS. 2 and 3 show two further embodiment examples of a tape magazine 40 , 50 according to the invention which only differ from the aforementioned tape magazine 10 with regard to the design of the brake. Hence identical components are labelled with the same reference numerals.
[0040] The tape magazine 40 shown in FIG. 2 also has a leaf spring 41 on an inner wall of the holder 12 below the dividing wall 14 which is pretensioned with a constant spring force F spring . In addition a rocking lever 43 is hinged around one axis 44 on the inner wall of the holder 12 . The free end of the rocking lever 43 is provided with a rotating deflector roller over which the test tape 30 is guided. The rocking lever 43 is arranged between the leaf spring 41 and the spool housing 21 and extends tangentially to the spool housing 21 . The rocking lever 43 touches the leaf spring 41 at a contact point 42 and the spool housing 21 at a contact point 45 . A constant spring force F spring is applied to the rocking lever 43 by the leaf spring 41 . Consequently a corresponding force is also applied to the spool housing 21 by the rocking lever 43 .
[0041] When the drive for the test tape 30 is actuated, it has to be reeled off at a certain tape tensile force F tape against the brake torque acting on the spool housing 21 . The tape tensile force acts upon the long lever arm of the rocking lever 43 via the deflector roller 46 and relieves the contact point 45 depending on the tape tensile force. Hence a lower tape tensile force has to be applied to reel off the test tape than in the case of the embodiment example shown in FIG. 1 as the diameter of the supply spool 23 decreases.
[0042] The embodiment example shown in FIG. 3 of a tape magazine 50 is formed to include a compensation mechanism that is loaded with a force that changes depending on the diameter of a tape spool of the storage unit. Tape magazine 50 has a rocking lever 51 on the inner wall of the holder 12 below the dividing wall 14 which is hinged on the inner wall around an axis 52 . The free end of the rocking lever 43 is also provided with a rotating deflector roller 53 over which the test tape 30 is guided. The rocking lever 51 also extends tangentially to the spool housing 21 and touches the spool housing 21 at a contact point that is not visible in the figure.
[0043] The compensation mechanism is formed by a rocker arm 54 that can rotate around an axis 55 is pivoted on the rocking lever 51 . The free end of the rocker arm 54 is provided with a follower roller 56 which rests on the circumference of the supply spool 23 at a contact point 58 . A pressure spring 57 which is pretensioned with a certain spring force F spring is braced against the dividing wall 14 and the rocker arm 54 such that this spring force is applied to the rocker arm 54 .
[0044] When the drive for the test tape 30 is actuated, it has to be reeled off with a certain tape tensile force F tape against the brake torque acting on the spool housing 21 . This tape tensile force acts upon the long lever arm of the rocking lever 43 and relieves the contact point between the rocking lever 51 and the spool housing 21 depending on the tape tensile force. At the same time the follower roller 56 of the rocker arm 54 runs on the circumference of the supply spool 23 . As the radius of the supply spool 23 decreases, the follower roller 56 travels towards the spool 22 so that the pressure spring 57 relaxes as the radius of the supply spool 23 decreases. Thus the contact point between the rocking lever 51 and the spool housing 21 is relieved as a function of the radius of the supply spool 23 . As a result the tape tensile force F tape that has to be applied by the drive remains constant as the radius of the supply spool 23 decreases.
[0045] FIGS. 4 and 5 show a combination of a hand-held device with polymer-based electronic components and a mechanical drive for the test tape.
[0046] The hand-held device 100 is a single-use device, a so-called disposable. It has a housing 101 made of plastic in which two reel bodies 102 , 103 are located. A test tape 104 with consecutive test fields is wound onto the reel bodies 102 , 103 . In an embodiment, device electronics are provided that are based upon integrated polymer circuits (IPC). A non-limiting example of which includes a photo-optic sensor 105 provided in the housing 101 in spatial vicinity to a measuring site 106 . At the measuring site 106 the test tape 104 is accessible from outside in order to take up a sample liquid such as blood for a blood sugar determination. The area between the emitter and receiver of the sensor and the test tape can be bridged by an optical path or light guide. The measured value recorded by the sensor 105 is transferred to an evaluation unit 109 . Here a display value such as the blood sugar content is calculated.
[0047] The photo-optical sensor consists of at least one light-emitting diode (LED) of a suitable wavelength, particularly an organic light-emitting diode (OLED), combined with one or more organic photodiodes (multi-photometer principle). LEDs of multiple wavelengths are also conceivable. It is further conceivable that the device may include an electrochemical detection system. In an embodiment, it is appreciated that the electrochemical sensor components are mounted on the test tape 104 and are connected to the device electronics at a measuring position.
[0048] The evaluation unit 109 comprises for example an amplifier, analog/digital (AD) converter, calculator, control mechanism, data store, energy supply and interfaces, and is connected to a display unit 110 which shows the determined display value on a display. The display unit can be designed in a known manner such that a display can be maintained until the next measuring process even without an energy supply for example by using so-called “electronic inks”.
[0049] The data store in the evaluation unit can consist of a read-only memory (ROM) or electrically erasable programmable read-only memory (EEPROM). It is mainly required to store batch-specific data which are determined during the manufacture of the disposables and are deposited thereon. Data transfer occurs by means of contact interfaces or radio-frequency identification (RF-ID) transponders. An electronic test field counter can also be realized using an EEPROM.
[0050] The electronic components of this hand-held instrument are known polymer-electronic components. Such components are described in for example in CA 2516490 A1 2004 May 27 the contents thereof being herewith incorporated into the disclosure of the present patent application. The use of such components enables all necessary electronic components to be integrated into a magazine housing so that the resulting tape magazine also constitutes a fully functional and very convenient single-use hand-held device. Such a single-use hand-held device is small and light, cost-effective and easy to operate. It is not necessary to change the tape magazine. It leaves room for further miniaturization of portable hand-held devices. It also obviates the necessity for a complicated construction of interfaces between the tape magazine and hand-held device.
[0051] All polymer-based electronic components can be printed in a known manner onto suitable moldings of the housing 101 of the hand-held instrument 100 .
[0052] The energy is supplied by high-performance capacitors (supercap) for example combined with solar cells/photovoltaic cells. Due to the low-energy density that can be achieved it is recommended to manually drive the spool bodies 102 , 103 of the described disposable hand-held device.
[0053] A transport mechanism is provided as a tape drive. For this purpose the reel bodies 102 , 103 have teeth or steps. A feed pawl 107 which is only indicated here engages in these teeth or steps. The feed pawl 107 is connected to a lever 108 provided on the outside of the housing. The test tape 104 is fed by operating the lever. This moves the reel bodies 102 , 103 exactly so far that a fresh test field of the test tape 104 is accessible from outside at the measuring site 106 . In order to synchronize the movement of the reel bodies 102 , 103 and test tape 104 , the latter is perforated such that teeth arranged on the reel bodies 102 , 103 (not shown) engage in the perforation. The test fields can also be spaced on the test tape in such a manner that a first operation of the lever 108 makes a fresh test field accessible at the measuring site 106 . A second operation of the lever 108 moves the test field which is now used away from the measuring site 106 without a new test field immediately appearing. This only occurs when the lever 108 is operated again.
[0054] The operation of the lever 108 can also generate in a known manner the energy of a few milliwatts required for the measurement which can for example be temporarily stored in a capacitor or supercap. A temporary mechanical store in the form of a spring can be provided to obtain energy by a generator or piezoelectrically which allows an adaptation to the various time constants.
[0055] A particularly environmentally friendly design of the device can be achieved by refraining from an electrochemical energy store. | The present invention concerns a tape magazine especially for a hand-held device for analyzing a body fluid with a test tape that can be unwound from a storage unit and wound onto a waste unit where the waste unit can be driven in order to wind forward the test tape. The invention provides that a lock which keeps the test tape under tension is integrated in the tape magazine at least on the storage unit. The present invention also concerns a hand-held device with such a tape magazine. The present invention also concerns a hand-held device with a mechanical drive for the test tape and a disposable hand-held device with polymer-based electronic components. | 8 |
This application is a continuation-in-part application of Ser. No. 385,166 filed Aug. 2, 1973, now U.S. Pat. No. 4,048,776.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a steel column base plate member for connecting a hollow or box-shaped steel column member having square, rectangular or annular section of a steel structure to concrete foundation therefor.
2. Description of the Prior Art
Steel column members of architectural buildings or construction structures are connected to concrete foundations, by means of base plates. It is well known that the steel column is stronger than the concrete of the foundation by a factor of not smaller than 10. To compensate for such difference of the strength between the concrete of the foundation and the steel column, the lower end of the column is joined to a steel plate, and the base plate is secured to the concrete foundation by means of anchor bolts embedded in the concrete foundation.
It has been suggested to provide a base for a column having a recess adapted to accommodate the lower end of the column as shown in U.S. Pat. No. 134,269 issued to J. Gray on Dec. 24, 1872. This base is formed at its center with the recess to reduce its thickness at the center so that the strength against a vertical force may become insufficient to support a load.
It has also been suggested to fit a foot within a lower end of a column which is then inserted into a bed-plate with a sleeve or socket to bring the foot into contact with the bed-plate, disclosed for example as in U.S. Pat. No. 198,072 issued to A. Bonzano on Dec. 11, 1877. This bed-plate will support a vertical force but insufficient to support a bending moment transmitted from the column which will probably been supported by the sleeve.
It has also been suggested to provide a base-socket having a supporting base member and an upwardly projecting portion containing a recess to receive the lower end of a column which is secured within the socket by riveting or the like. Such a socket has been disclosed in the U.S. Pat. No. 1,258,409 issued to T. Hill on Mar. 5, 1918. However, the socket has a configuration prone to give rise to a stress concentration and fails in smooth stress transmission through the socket from the column to a concrete foundation.
It has been proposed to join a tubular member to metal parts wherein the tubular member is fitted within a metal part and a plug or wedge is press fitted in the tubular member. Such a connection has been disclosed in the U.S. Pat. No. 1,488,128 issued to H. P. Macdonald on Mar. 25, 1924. However, this arrangement is not suitable for use in a construction to be subjected to great forces and bending moments.
It has also been proposed to join a tube to a metal part by the use of welding with the aid of beveling portions of the tube. Such a connection of tubing has been disclosed in the U.S. Pat. No. 2,867,036 issued to H. Hovelmann on June 6, 1959. In the method, however, it is required complicated machining for providing the beveling for welding which will increase cost of the connection.
Generally speaking, the base plate member is required to fulfill the following conditions.
1. Since the base plate will be subjected to various severe forces resulting from axial force, shearing force and bending moment acting upon the column member, the base plate must be in configuration to avoid any stress concentration and perform a smooth stress transmission from the column member to the foundation.
2. In order to decrease the cost of a construction as a whole, the working of column member should be minimized only to cutting of both ends thereof. If any grooves for welding are required, the base plate member should be formed with such grooves by the use of means of minimum possible cost.
3. If utilizing any welding method for connecting the base plate member to a column member, the base plate member should be of a configuration capable of applying the most effective welding method which is higher in reliability, minimum of consumed welding rods and carried out with ease. The configuration is also applicable of a best welding method of which characteristic meets stresses derived from forces and bending moments to which the column member is subjected.
4. The base plate member should be a configuration in agreement with a stress distribution acting thereupon resulting from axial and shearing forces and bending moment to which the column member is subjected.
5. The base plate member should be such a configuration that a base portion of the base plate member in contact with a concrete foundation will not be affected by heating derived from welding of the plate member with the column member.
6. The base plate member should be economical of manufacture and serve to decrease the cost of a construction as a whole.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a steel column base plate member for connecting a hollow steel column member to a concrete foundation which overcomes the above disadvantages in the prior art and fulfills the above requirements for this kind of the base plate.
It is another object of the invention to provide a steel column base plate member, which has a novel configuration to avoid any stress concentration to perform a smooth stress transmission from a column member to a foundation and to make it possible to perform a J-shaped groove welding between a lower end of column and base plate adapted to meet stresses acting upon the base plate.
It is further object of the present invention is to provide a novel base plate member, which is formed by casting or forging in a unitary body with grooves formed on the top surface of projections for effecting the J-shaped groove welding and has a configuration in agreement with a stress distribution acting thereupon and adapted not to be subjected to a detrimental effect of welding heating with the surface in contact with the foundation.
It is still more object of the invention to provide a base plate member for connecting a hollow steel column member to a concrete foundation, which is inexpensive of manufacture and serves to decrease the total cost of a construction.
In one aspect, the invention provides a base plate member for connecting a hollow steel column member to a concrete foundation, which base plate member is a unitary body comprising a steel column base plate member for connecting a hollow steel column member to a concrete foundation, which base plate member is a unitary body comprising a substantially planar bottom plate portion engageable with said concrete foundation, a projection upwardly extending from the planar bottom plate portion and having a top surface whose shape is substantially identical to but somewhat wider inwardly than cross sectional shape of the steel column member, J-shaped welding grooves formed along overall outer edges of said top surface of said projection facing to a lower end of said column member extending from outer peripheries of the top surface of said projection so as to effect J-shaped groove welding between said lower end of the column member and the J-shaped welding grooves, a sloped top surface formed between said projection and said bottom plate portion so as to increase the thickness thereof as the planar bottom plate portion extends toward said projection, and abutments formed on the planar bottom portion in a sufficient thickness and having anchor belt holes bored therethrough.
In another aspect, the invention provides a method of connecting a hollow steel column member to a base plate member, wherein said base plate member comrises a substantially planar bottom plate portion, a projection extending from the planar bottom plate portion and having a top surface whose shape is substantially identical to but somewhat wider inwardly than cross sectional shape of the steel column member, J-shaped welding grooves formed along overall outer edges of said top surface of said projection facing to lower ends of flanges of said column member, the improvement characterized by, the steps of connecting at least one strap to inside of the lower end of said steel column member by welding so as to substantially in opposition to a residual top surface formed with said J-shaped grooves for determining an axial position of said column member relative to the base plate member, placing the lower end surface of said column member onto said top surface of said base plate member in desired relation, and effecting J-shaped groove welding along said J-shaped grooves of said base plate member between bottom surface of said column member and said grooved surfaces of said base plate member.
BRIEF DESCRIPTION OF THE DRAWING
For a better understanding of the invention, reference is made to the accompanying drawing, in which;
FIG. 1 is an elevation of a steel column base plate member for supporting a hollow column member having a square section, according to the invention;
FIG. 2 is a plan view of the base plate member of FIG. 1;
FIG. 3 is a perspective view of a base plate member for a hollow column member having a circular section, according to the invention;
FIG. 4 is a perspective view of a base plate member for a box-shaped column member formed on its top surface with bosses according to the invention;
FIGS. 5a, 5b and 5c are sectional views explanatorily showing the butt welding and lower end of the column member;
FIG. 6 is a sectional view of a typical box-shaped column member for explaining the directions of the column member subjected to bending moments;
FIGS. 7a and 7b are schematic sectional views of J-shaped groove weld and L-shaped groove weld, respectively; and
FIG. 8 illustrates various reaction distributions depending upon the relation between bending moments and compressive forces.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a steel column base plate member 20 according to the present invention is to join a box-shaped steel column member or hollow steel column member having a square section 1 to a concrete foundation 2. The base plate member 20 itself is secured to the concrete foundation 2 by anchor bolts 17 and nuts 17a.
The base plate member 20 has a planar bottom plate portion 6 whose bottom surface area is large enough to distribute the load of the steel column member 1 to the concrete foundation 2 at a stress which is below an allowable limit to the concrete member of the foundation 2 through the interface between the base plate member and the concrete foundation. A projection 7 is integrally formed with the planar bottom portion 6 so as to form a top surface 7a whose shape is substantially identical to the cross section of the hollow steel column member 1, said top surface 7b of projection having a broader width than that of the steel column member 1, and a J-shaped groove 5 formed along all the edges of top surface 7a of projection, the width of which groove 5 is substantially identical to the bottom surface of flange of the steel column member so as to effect groove welding between the grooved surface of projection and the bottom surface of steel column member, and a residual top surface 7a of projection extending inwardly from the edge thereof.
Referring to FIG. 1, the height H of the projection 7 is determined on the basis of the ease of welding the column member 1 to the top surface 7a and the suppression of the welding strain or bending of the base plate member 20 due to the welding of the column member 1 thereto.
Smoothly curved surface portions 8 are formed where the projection 7 rises from the planar portion 6, so as to eliminate any stress concentration in the base plate member 20 due to the presence of sharp corners. Thus, the radius of curvature of the curved surface 8 must be chosen on the basis of effective suppression of the stress concentration. Whereby, the smooth transfer of the load of the column member 1 toward the concrete foundation 2 is ensured.
The planar portion 6 has a sloped or tapered top surface 6a, so that the thickness of the planar portion 6 increases as it extends toward the projection 7. With such sloped top surface 6a, the thickness of the planar portion 6 is increased at those parts where the stress is high, while allowing comparatively thin thickness to the less stressed parts thereof. As a result, the rigidity of the projection 7 is enhanced, too. Furthermore, superfluous thickness of the base plate 20 is eliminated.
Abutments 9 are integrally formed at the parts where anchor bolt holes 11 are bored through the base plate member 20. The top surface of the abutment 9 is made parallel to the bottom plane of the planar portion 6, so as to stabilize the contact surface between the nut 17a and the abutment 9. It is, of course, possible to insert suitable washers (not shown) between the abutment and the nuts 17a. Referring to FIGS. 1 and 2, the width and the thickness d of the abutment 9 are so chosen as to ensure smooth transfer of the load of the column member 1 toward the anchor bolts 17. Suitably curved surfaces 10 are formed at the junction between the abutment 9 and the projection 7, for preventing stress concentration thereat.
The steel column base plate member 20 of the aforesaid construction may be made by casting or by forging.
According to the present invention, the top surface of the projection has a width broader inwardly than that of the thickness of the column member.
The J-shaped groove 5 is formed along the edges of top surface 7a of projection, the width of which groove 5 is substantially identical to or broader than the thickness of the bottom surface of the steel column member so as to effect groove welding between the J-shaped grooved surface of projection and the bottom surface of the steel column member and the residual top surface 7a of projection extending inwardly from the edge of groove so as to determine a vertical position of the column relative to the base plate with the aid of straps later explained. The J-shaped welding grooves 5 are formed at the time of casting or forging of the base plate member 20 per se.
FIG. 3 illustrates a steel column base plate member 20 formed with an annular J-shaped welding groove 5 for welding a steel column member having a circular section.
Though the box-shaped or hollow column member has been shown as the square or circular sectional column member, it may have any other section such as triangular, rectangular, polygonal, elliptical or any other irregular section.
The base plate member may be preferably formed with a center line or center lines (not shown) at the time of casting or forging corresponding to scores marked in the column member by a scraper and lines marked in the concrete foundation for facilitating the correct registering of the base plate member 20 relative to the column member and the concrete foundation.
To facilitate the correct registering of the steel column member 1 relative to the base plate member 20, suitable bosses 12 may be provided at the top surface 7a of the projection as shown in FIG. 4.
In actual construction, in order to determine the position of the column member relative to the base plate member in a vertical direction, straps 16 are fixed to the insides of the column member at its lower end by means of welding as shown in FIG. 5. The strap 16 is preferably positioned slightly inside of the lower end of the column member such as a few millimeters, at most 5 millimeters. In this case there is no risk of extruding of J-shaped groove welded bead 14 into the inside of the column member, so that the straps are not necessarily provided on overall inside of the column member. A strap 16' of which end is flush with the lower end of the column member should be provided on overall inside of the column member to prevent the J-shaped groove welded bead 14 from extending into the inside of the column member. In this case, however, the lower end of the column member with the strap 16' is preferably machined after the welding of the strap. A strap 16" may be provided which slightly extends from the lower end of the column member. If a column member has a circular section, the strap 16 may be annular or annular segmental along the inside of the column member.
In the actual construction, J-shaped groove welding or butt welding is performed along the top surface 7a to form welding beads 14 as shown in FIG. 5. It is apparent to those skilled in the art that the use of bosses 12, as shown in FIG. 4, will facilitate the registration or indexing of the column member 1 with the base plate member 20.
In using the base plate member 20 according to the invention for a construction, the straps 16 or 16' are welded to the insides of the column member at its lower end and the top surface 7a is brought into contact with the lower end of the straps of the column member with the aid of the center lines of the plate member in registry with the scores of the column member. Tack welding is effected at several locations between the lower end of the column member and the grooves of the base plate member for fixing a relative position therebetween to facilitate the subsequent butt welding. Then J-shaped groove welding or butt welding is effected to form beads 14 between the lower end of the column member and the protrusion 7.
The column member and the base plate member thus united are brought onto a concrete foundation such that anchor bolts 17 extending from the foundation pass through the anchor bolt holes 11 and the center lines of the base plate member are in registry with the lines marked in the concrete foundation. The nuts 17a are threadedly engaged with the anchor bolts 17 and then tightened with a determined amount of torque as by means of a suitable equipment such as a constant torque wrench.
The base plate member for the H-shaped column member according to the present invention has following characteristics distinguishable over those in the prior art.
1. Outer configuration
The base plate member according to the present invention has the configuration as shown in FIGS. 1, 2, 3 and 4. There are smoothly curved surface portions 8 at the junctions between the projection 7 and the sloped top surface 6a and further smoothly curved surface portions at the junctions 10 between the abutments 9 and the planar bottom portion 6. These smooth surfaces prevent any stress concentration and serve to transmit smoothly the load from the column member to the concrete foundation.
The flaps 16 welded to the column member are in contact with the top surface of the base plate member to provide a metal contact which serves to keep an accuracy of the height of the column member and makes it easy to set the column member on the concrete foundation.
The J-shaped grooves for butt welding are integrally formed in the base plate in casting or forging so that the forming of the J-shaped grooves scarcely increases the cost of the base plate and the column member is not required to have any worked portion for butt welding. Accordingly, the working of column members will be simplified to save time and cost for manufacturing the construction.
2. Application of butt weldings
It has been known that shearing strengths of fillet and butt welded portions at their throats are substantially equal to each other, while the tensile strength of the butt welded portion is generally higher than that of the fillet welded portion.
Box-shaped or hollow section steel column members are used in the case that bending moments act on the column members in both x and y directions (FIG. 6). Accordingly, all four walls of a rectangular hollow column member are subjected to compressive and tensile forces due to the bending moments, so that the four walls of the column member are connected to the base plate member by butt welding or J-shaped welding which is more effective to resist to a tensile force. Therefore, the base plate member for the hollow column member according to the invention utilizes the characteristics in strength of the butt welding to enable the base plate to support a load in the most effective manner.
An amount of weld metal or deposited metal in the J-shaped welding is less than those in any other welding methods for the same purpose. The reliability in penetration or weld penetration in the proximity of the root of J-shaped groove weld is higher than those in any other methods and also higher than that in L-shaped groove weld as shown in FIG. 7. The J-shaped groove welding operation can be carried out with ease. In spite of these advantages, the J-shaped groove welding requires to form J-shaped grooves which are apt to increase the cost of welding. According to the invention by casting and forging the base plate member, J-shaped grooves can easily be formed in the base plate member, so that the base plate member can utilize the advantages of the J-shaped groove welding without increasing cost for providing the J-shaped grooves.
3. Dynamics on the base plate
The column member is subjected to the axial force N, the bending moment M and the shearing force Q which act between the base plate and the concrete foundation. Depending upon the magnitude of these forces and their combination, a reaction force between the base plate and the foundation varies in distibution and amount as shown in FIG. 8. FIG. 8A shows the reaction force in case of the bending moment is relatively small in comparison with the compressive force, FIG. 8B is in case of the bending moment is normal or intermediate and FIG. 8C is in case of the moment is a great value. In any case, these compressive force, bending moment and shearing force simultaneously act upon the column member, so that reaction forces are caused between the base plate member and the column member as shown in arrows in FIG. 8 wherein solid lines of the arrows show theoretical distribution of the reactions and dot-and-dash lines show actual distributions. In case of FIG. 8C, due to the great moment, one flange of the column member tends to raise to cause a great tensile force in anchor bolts.
When the base plate member is subjected to a great contact force in an axial direction of the column member which causes a bending action (a positive bending moment) on the plate member, so that the plate member is required to have sufficient yield strength and rigidity to resist to the bending action.
When the anchor bolts are subjected to a great tensile force as shown in FIG. 8C, a great reaction force is caused in the proximity of the holes for the bolts formed in the base plate and results in a bending action (a negative bending moment) on the plate member, so that the member is required to have sufficient yield strength and rigidity to resist to the action.
The bending moment and the shearing force generally act on the base plate member as alternate stresses. Accordingly, the base plate member is generally required to have a symmetrical yield strength and rigidity. The yield strength will resist to the stress so as not to be broken and the rigidity will resist to the stress so as to restrain a deformation.
At any rate, when the base plate member is subjected to reaction forces as shown in FIGS. 8A, 8B and 8C, the base plate will be subjected to a bending action of which bending stress is maximum at the place on the base plate member in opposition to the flanges and web of the column member.
Accordingly, the feature of the projection 7 of the base plate projecting from the base portion and corresponding to the sectional area of the column member and the feature of decreasing the thickness of the bottom plate portion toward the outer ends thereof provided a rational configuration in agreement with the stress distribution. In addition, with the configuration the top surface of the projection to be welded to the lower end of the column member is remote from the base portion of the base plate member so as to be remote from the portions subjected to violent heating for welding, thereby preventing the base portion from deforming in welding. The base plate member having a changing thickness can be advantageously made by casting or forging.
4. Cost comparison
We compared the cost of the cast steel base plate members according to the invention with that of the prior art steel base plates for box-shaped column members having one side of 550 mm. One example of the comparison is indicated in Table I.
Table I__________________________________________________________________________ Cast steel base plate Steel base plate (Present invention) (Prior art) Total Total Total Total Unit price weight cost weight cost__________________________________________________________________________ 640 lbs $387Casting $0.605/lb (Y400/kg) (290 kgs) (Y116,000) 0 0 1,072 lbs $162MaterialSteel plate $0.151/lb (Y100/kg) 0 0 (486 kgs) (Y48,600) cost 110 lbs $46.7Welding rod $0.423/lb (Y280/kg) 0 0 (50 kgs) (Y14,00) 640 lbs. $387 1,182 lbs $208.7 Total (290 kgs) (Y116,000) (536 kgs) (Y62,600)WorkingLabor cost $33.3/man (Y10,000/man) costIndirect $16.7/man (Y5,000/man) 0 0 4.96 man $248cost (74,400) Total $387 (Y116,000) $456.7 (Y137,000)Economical Comparison 85% 100%__________________________________________________________________________
A number of cast steel base plates of totally 640 lbs according to the invention were used in the comparison, which only require casting operation but not require any other operation such as working or welding operation for providing the base plates themselves. Accordingly, the total cost was $387. In contrast herewith the steel base plates of the prior art require the steel plates of 1,072 lbs and welding rods of 110 lbs for providing the number of the base plates equal to the above cast steel plates and further require the working operation with direct and indirect costs, so that the total cost was $456.7. The cost of the cast steel base plate according to the invention is only 85% of that of the welded steel base plate of the prior art.
As can be seen from the above description, the base plate member according to the invention has a various of novel features of the configuration making it possible to effect a J-shaped groove welding or butt welding to meet the stress condition acting upon the column member and the base plate; preventing the base portion from deforming in welding by arranging the welding portion on the top of the protrusion remote from the base portion; having an effective sectional shape to meet the bending stress distribution; and making it possible to effect the effective J-shaped groove welding.
It is understood by those skilled in the art that the foregoing description is a preferred embodiment of the disclosed base plate and that various changes and modifications may be made in the invention without departing from the spirit and scope thereof. | A steel column base member for connecting a hollow or box-shaped structural steel column member having square, rectangular or annular section, to a concrete foundation, which base plate member is an integral cast or forged body comprising a bottom plate member to engage the foundation, a box-shaped projection upwardly extending from the bottom plate member and having J-shaped grooves formed along overall outer edges of top surface of projection the width of web of projection being broader than thickness of column member, so as to effect groove welding between the bottom surface of the steel column member and the J-shaped grooved surfaces. A method of connecting an hollow or box-shaped steel column member to a base plate member is characterized by, effecting J-shaped groove welding along between J-shaped groove surfaces of base plate member and the bottom surfaces of steel column member. | 4 |
TECHNICAL FIELD
This invention pertains to the manufacture of gears. More specifically, this invention pertains to a new process for smoothing and shaping of gear tooth surfaces. It includes gear run-in or polishing in place for smoothing or re-shaping of tooth surfaces of newly formed gears.
BACKGROUND OF THE INVENTION
Gears have long been used in power transmitting machines and mechanisms to increase or decrease an applied torque or the direction in which a torque is applied. Gears are often formed as wheels, worm wheels or linear racks. Elegant gear manufacturing processes have been developed to form the teeth on the wheel or rack structure.
In the case of gear wheels, the basic gear form with unfinished teeth can be, e.g., cast or forged from a blank of a suitable metal alloy. A hardenable steel, such as AISI 5620, is often a material of choice. Teeth are cut into the circumference of the wheel using a hob or other suitable tool. The surfaces of the hobbed teeth are often then further machine finished or polished so that they are precisely shaped and smooth for good engagement with a counter-gear. Grinding, honing and/or chemical polishing are examples of such gear tooth finishing processes.
In the automotive industry, millions of gears are manufactured each year. In one particularly large manufacturing volume application, e.g., planetary gear sets are commonly used in automatic transaxles. Such planetary gear sets contain at least three main components: a sun gear, a carrier assembly with a plurality of planet pinion gears and an internal gear. The sun gear is located at the center of the planetary gear set and has planet pinion gears revolving around it. These planet pinion gears have gear teeth that are in constant mesh with the sun gear. An internal ring gear encompasses the entire gear set. Torque from the engine (input torque) is transferred to the gear set and forces at least one of these components to rotate. Since all three main components are in constant mesh with each other, the remaining components are often forced to rotate as a reaction to the input torque. After input torque passes through a gear set, it changes to a lower or higher torque value known as output torque. In a front wheel drive automobile transaxle, for example, two such suitably sized gear sets are combined and controlled to provide forward drive ratios and a reverse drive. The output torque from the second gear set then becomes the force that is transmitted to the vehicle's drive axles.
The automobile automatic transaxle is but one example of gear set containing mechanisms that must be carefully designed for minimum cost of manufacture and to sustain high loads over a long product life. The need for continuous improvement in automobile design has required engineers to obtain unreduced or greater output from smaller and lighter robust gear mechanisms.
It is observed that the operating life of a power transmitting mechanism such as an automotive automatic transaxle depends significantly on the fatigue life of the gears. There seem to be two main approaches to increasing the fatigue life of a gear set: improving tooth shape and contact area and increasing the hardness of tooth wear surfaces. The improvement of tooth shape and contact area has been accomplished by expensive machining operations and by unselective natural wear-in or run-in of a newly made and assembled set during the first hours of operation of the mechanism. The increase in the tooth hardness has been accomplished by metallurgical surface hardening, e.g., induction surface hardening of a hardenable steel, or carburization and heat treating of an iron or steel alloy, or by application of a thin coating of hard material such as diamond-like carbon, titanium nitride, boron carbide or the like. While such hardened surfaces increase the fatigue life of a gear set, care must be taken to polish the hard surface or it may cause excessive wear of the mating gear surface by abrasion.
The gear making art requires improvements in the manufacture of suitably shaped gear teeth, and the use of hardened gears, and in the assembly of such gears in a robust power transmission mechanism.
SUMMARY OF THE INVENTION
In a first embodiment, this invention provides an improved method of using a dummy or expendable counter-gear to smooth a hard surface-coated gear before assembly of such gear with an intended counter-gear in a power transmission mechanism. The goal of this smoothing is to remove sharp edges and asperity tips of the hard coating and to reduce the abrasiveness of the coated surface.
In another embodiment of the invention, an expendable hard surface coated counter-gear is used as a low cost and practical tool to run-in and re-shape softer complementary gears before assembly of such gears in a mechanism.
For purposes of illustration, but not limitation, the invention will be described for the case when the changes in the surface of a hard surface-coated sun gear include smoothing, polishing and reduction in its abrasiveness, while the changes in the surface of pinion gears, intended for assembly in a planetary gear set, include polishing and re-shaping.
In one example, an unpolished boron carbide coated sun gear is operated under substantially a design level load and operating temperature against a dummy pinion gear that may be essentially identical to the pinion gears that are to be assembled with the sun gear in a planetary gear set. It is found that a very few rotations of such a sun gear against the expendable pinion smoothes the rough surface asperities of the thin (2-3 micrometers) B 4 C coating. The run-in sun gear is then assembled with design specified pinion gears in the design assembly. The dummy pinion is used to smooth more hard-coated sun gears. From the initial operation of the newly assembled mechanism, the run-in sun gear provides the fatigue life benefits of its hardened teeth surfaces without undesirable abrasion of the pinion teeth.
In the converse example of this invention, a suitable sun gear with hard tooth surface is used to reshape pinion gears. After a group of pinions have been formed by a suitable and practical manufacturing process, one or more at a time are rotated at substantially design load and operating temperature against the dummy sun gear with hard tooth surface. The dummy sun gear is suitably identical to the gear designed for assembly with the pinion(s) and a brief rolling operation gives a “final” shape to the pinions prior to their assembly with the sun gear actually made for the machine.
Other objects and advantages of the invention will become more apparent from a detailed description of the invention which follows. Reference will be had to the drawing figures that are described in the following section.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an exemplary planetary gear set, components of which can be processed in accordance with this invention.
FIG. 2 shows split, greatly enlarged sections of a sun gear tooth illustrated in FIG. 1 . The left side of FIG. 2 shows schematically the rough, asperity carrying, as-formed coating of boron carbide on a steel tooth. The right side of FIG. 2 is a schematic view of the tooth after treatment in accordance with the invention.
FIG. 3 is an enlarged sectional view of a pinion tooth illustrated in FIG. 1 .
FIG. 4 is a schematic view of an apparatus for running-in sun gears and pinions in accordance with this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The practice of this invention will be illustrated in the making of sun gears and pinion gears for assembly into a planetary gear set. However, it will be recognized by those skilled in the art that this invention is applicable to the manufacture of many different gear and counter-gear combinations.
FIG. 1 is a perspective view of a portion of an illustrative planetary gear set 10 . Planetary gear set 10 includes sun gear 12 , four planetary gears 14 , a planetary gear carrier (not shown) and gear ring 16 with internal gear teeth 18 . Gear ring 16 encompasses the entire gear set. Sun gear teeth 20 mesh with the teeth 22 of planetary gears, which in turn mesh with the teeth 18 of the gear ring. Thus, the teeth of the three gear elements must be compatible and intermesh with each other. As illustrated, planetary gears 14 with their teeth 22 are substantially identical. If the sun gear is driven (by means not shown) in a clockwise direction as seen in FIG. 1, the four pinion gears would be driven in a counterclockwise direction. Gear ring 16 may or may not be permitted to rotate, depending on the intended purpose of the mechanism. A planetary gear set like that depicted at 10 often is used in cooperative combination with another gear set in automotive transmission devices.
Since sun gear 12 is often a power input gear and it interacts with four (for example) pinion gears, the surfaces of sun gear teeth 20 are often hardened or provided with a hard coating. When sun gear 12 is made of a hardenable steel, it is often a practice to simply induction harden the surfaces of its teeth 20 . In other practices, the sun gear may be formed of a ferrous alloy into which carbon may be introduced by a suitable carburization process so that the surfaces of teeth 20 become carbon enriched and therefore more hardenable. Following the carburization, a suitable heat treatment increases the hardness of teeth 20 of sun gear 12 . In still another practice, a suitable hard coating such as a coating of titanium nitride or of boron carbide may be applied by a deposition process to the surface of teeth 20 of sun gear 12 . The purpose of such hard coating is to increase the hardness of the tooth surfaces of the sun gear so that it becomes a more durable gear part; that is, it has a greater fatigue life when it is caused to transmit a torque applied to it to a plurality of pinion gears that work in cooperative engagement with it.
The surfaces of hardened teeth 20 of sun gear 12 are often quite rough as formed. The practice of carburizing and heat treating gears often leads to a rough surface. It is also recognized that the application of a thin, hard coating layer to the surfaces of teeth 20 also forms a rough abrasive surface layer that will interact with the usually relatively softer teeth of pinion gears 14 .
It is known that the abrasive action of a hard coating on a gear can change the surface morphology of gears against which it rubs. For example, a gear, bearing or other component that is coated with TiN, B 4 C or diamond-like carbon (DLC) can polish an uncoated gear or bearing against which it runs (a counterpart). Since the lifetime of these parts is controlled by rolling contact fatigue (RCF) which in turn is strongly affected by the roughness of the parts which rub together, such a polishing action may prolong the life of the coated parts and their counterparts. This mechanism has been proposed to explain why very thin coatings such as TiN, B 4 C and DLC can reduce rolling contact fatigue on gears, bearings and other components. On the other hand, a coating which is too abrasive can wear away so much material from a counterpart that the parts no longer function properly. In accordance with this invention, it is proposed that the abrasiveness of a coating be controlled by performing a run-in of a predetermined duration against a dummy counterpart.
It has been found during work on this invention that the rate at which a coating loses its abrasiveness is remarkably high. For example, the abrasiveness of DLC coatings is reduced by at least 60% on each cycle, i.e., one full rotation against a counter-gear. Under some conditions, the abrasiveness can be reduced nearly to zero on a single cycle. The explanation is that abrasiveness is caused by the presence of very sharp asperities, and the tips of these sharp asperities are subjected to the highest possible stresses, which crush them almost immediately. This is illustrated in FIG. 2 as follows.
FIG. 2 shows a split view of a single enlarged tooth 20 of sun gear 12 . Sun gear 12 has been formed of a hardened steel alloy AISI 5620 with increased manganese content. A coating 26 of boron carbide (B 4 C) about three micrometers thick has been deposited on the surface 24 of tooth 20 . In the as-deposited form, the surface of coating 26 is characterized by many abrasive asperities 28 . Other hard coatings and hardened iron or steel surface layers display rough, abrasive asperity containing surfaces like that depicted schematically in the left half of FIG. 2 . If a surface hardened gear is assembled in this as-formed condition with counter-gears, the abrasive surface is very likely to cause unwanted wear of the counter-gear. However, in accordance with this invention, the as-coated or hardened sun gear 12 is run-in over a few rotations (e.g., 1-3 rotations) against a dummy or expendable pinion gear (like pinion 14 ) and its abrasive surface smoothed so that it appears as illustrated in the right side of FIG. 2 . In particular, the rough edges and asperities which would have caused most of the excessive wear on a counterpart are removed.
The result is that the run-in process might well consist of only one or a few cycles, lasting less than one second. A feature of the subject invention is that each hard coated part be run against a dummy uncoated counterpart immediately after coating. This run-in practice is conducted to reduce the abrasiveness of the coating enough to avoid excessive wear of the counterpart while still leaving enough abrasiveness to give the coated part the ability to polish a future counterpart. Thus, in a preferred embodiment, a run-in process is sought for the hardened gear that removes its destructive abrasiveness while leaving its hardened surface capable of performing some useful polishing on the intended softer countergear.
In general, the reduction in the abrasiveness of the coating is proportional to the duration of the run-in process. By varying the duration of the run-in process, the abrasiveness may be adjusted.
To determine a preferred duration of the run-in process, a test may be set up in which a number of coated gears are run-in for different periods of time. The abrasiveness of the coating is then reduced more on gears run-in for longer time than on gears run-in for shorter time. Then each of these run-in gears is meshed with a typical counterpart under the typical conditions (load, speeds, lubrications, temperatures, etc.). One can measure the amount of the polishing of the counterparts and find the optimal amount. The coated gear that produced said amount is therefore run-in to an optimal abrasiveness. Duration of the run-in process applied to this coated gear is optimal and can be replicated for the other coated gears.
As an example of the embodiment of the proposed invention, the use of it as it pertains to coated gears is described. According to one of the methods of production, the gears are hobbed, shaved, carburized and coated with the hard, abrasive coating. In this invention, it is proposed to engage a freshly hardened or coated gear with a second gear, and the two gears are rolled one against another (i.e., run-in) for a time that is sufficient to remove the abrasiveness of the coated gear that would damage countergears intended to engage it. In a preferred embodiment, the duration of the coated gear run-in process is chosen to leave it with the capability to polish the future counterpart but not wear it excessively and is determined as described above. The second gear is a disposable dummy gear, used on a succession of coated gears. As a result of this operation of rolling against the dummy gear, the coated gear loses a predetermined amount of its abrasiveness.
In another embodiment of the invention, an unhardened gear such as a pinion gear 14 is briefly subjected to a run-in process for the purpose of giving the relatively soft gear its final desired configuration before assembly into a gear set. In the absence of expensive machining operations such as honing, final grinding and the like, the shape of a newly manufactured gear is not fully compliant to a countergear; that is, it is not ideally shaped for full conjugated motion with a counter-gear member in applications where they transmit heavy loads. These are possible sources of the imperfections:
1. The surface of the as-machined gears is relatively rough. Stress concentrations develop on the tops of asperities, squeezing the lubricant away. Undesirably small gear tooth areas with metal-to-metal contact may occur, resulting in high friction and accelerated wear.
2. There are inevitable manufacturing errors. For example, some teeth may have positioning errors; the gear axis may be misaligned. Another example of the manufacturing errors could be the deviation of the tooth surfaces from the true involute. Albeit small (of the order of microns or even less), these errors result in some teeth being loaded more and some teeth being loaded less. In similar fashion, some parts of the tooth may be loaded more and some parts of the tooth may be loaded less.
3. Gears and their teeth, as all elastic bodies, change their shape under load. These shape changes are proportional to the load and are similar to or bigger then the manufacturing errors. Although they are supposed to be compensated during manufacturing, it may not always be the case.
In accordance with this invention, a hardened counter-gear such as the sun gear 12 is employed solely for the purpose of giving softer gears such as pinion gears 14 a final brief shaping operation before the pinion gears are assembled in combination with the actual intended design sun gear. It is found that a relatively few cycles or complete rotations of one or more pinion gears against a hardened sun gear gives the pinion gears a slight final reshaping that better suits their actual compliance for lower stress operation in a finally-assembled gear set. This practice is illustrated schematically with the enlarged tooth portion 22 of pinion gear 14 . FIG. 3 is a greatly enlarged section view of a tooth 22 , and the dashed line 32 at the left side of the tooth shows the original shape of the tooth. The solid surface 30 with reference line 34 shows a slight change in the configuration of the tooth.
As a result of this re-shaping, asperities, initially protruding above the pinion tooth surface, are worn away. In general, any part of the tooth surface carrying overly high contact load is worn away as well. Hence, this re-shaping affects the distribution of contact stresses: The areas which initially bore high stress will be worn away, creating higher contact area and lower local pressure. Conversely, the areas initially unloaded (at the expense of heavier loaded areas) will be loaded more. Therefore, while the overall load carried by a particular tooth remains approximately the same, the load will be distributed more uniformly. Stress peaks, present originally, will be eliminated.
The practice of the invention is further illustrated schematically in FIG. 4 .
In FIG. 4, a surface hardened gear 112 of identical gear shape and configuration as sun gear 12 is adapted for rotation on a drive shaft 111 . Planetary gears 114 which have been newly made and shaped are also temporarily mounted on driven shafts 113 . Shafts 113 are rotatable and linearly translatable so that the newly-made pinion gears 114 can be rapidly inserted on them and brought into torque load engagement with the sun gear dummy 112 . The gears are rotated together for a few cycles of the pinion gears so that the hard toothed sun gear 112 gives preliminary wear-in shape to pinion gears 114 . Following their wear-in process in which their teeth are polished and reshaped, the pinion gears are quickly removed from shafts 113 and new pinions inserted for a like shaping operation. Pinion gears are given final shaping for assembly in a gear set with a design sun gear 12 . Of course, design sun gear 12 may have been pretreated against a dummy pinion gear just as pinion gears 114 were pretreated against a dummy sun gear 112 .
It is apparent that the apparatus in FIG. 4 is quite schematic. The dummy sun gear 112 would be mounted for extended usage, whereas the driven shafts 113 would be mounted for fast repositioning so that pinion gears 114 may be rapidly placed on the shafts and the shafts moved so that the pinion gears 114 are brought into engagement with the teeth of sun gear 112 . Subsequently, the shafts 113 are moved away and the newly-shaped pinion gears removed and replaced with other pinion gears to be processed. It is thus intended that a single dummy sun gear 112 could be employed in the reshaping of many pinion gears 114 .
Similarly, where a dummy pinion gear is used to remove the asperities from sun gears, it is intended that a single expendable or sacrificial pinion gear could be employed in the treatment of many sun gears to remove their surface roughness and smooth them for more robust operation in a gear set assembly.
While this invention has been described in terms of some specific embodiments, it will be appreciated that other forms can readily be adapted by one skilled in the art. Accordingly, the scope of this invention is to be considered limited only by the following claims. | The fatigue life of gears, for example, the gears in a sun gear-planetary gear set, is markedly improved by forming the respective gears by ordinary manufacturing practices and then running each new gear against a durable, but expendable, dummy of its counter-gear. The teeth of a dummy sun gear may be suitably hardened and used under suitable loads to minimally reshape the teeth of a plurality of newly-made pinions so that they are smoothed and better fit an intended sun gear. Similarly, the roughened teeth of a hardened or hard coated sun gear can be smoothed by running it for a few rotations against an expendable pinion. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/332,948, filed Nov. 13, 2001, the contents of which are incorporated by reference in its entirety for all purposes.
TECHNICAL FIELD
This invention relates to the field of laboratory science and more particularly to the systems, methods and apparatus that can be used in the laboratory.
BACKGROUND
Advances in science have made it possible to extract a wide variety of information about an individual from a biological sample obtained from that individual. For example, it can assess the health, identify possible future health issues, and provide the genetic makeup of the individual. The results of any analysis, however, loose much of their beneficial qualities when the analysis is attributed to the wrong individual or if the sample is processed incorrectly.
Much, if not all, of these analyses are processed in laboratories. The laboratory usually obtains its samples from institutions, such as the hospital, clinic, or police, and from individuals, such as samples sent to it from individuals using, for example, a Home HIV test kit. In these laboratories, many samples are processed daily where they may pass through many sets of hands and potentially be subjected to many different tests. Each time a sample is handled, there is the potential for an error to occur. In many cases, a human operator is the source of the error. For example, in the collection of the sample, the sample should be clearly identified, e.g., from whom the sample was obtained. Samples, however, once removed from their natural environment, such as an individual's person, tend to look very similar to other samples of like kind. Because of this, mix-ups have been known to happen when the information was incorrectly transcribed, labels were placed on the wrong samples, or the identifying information was inadvertently omitted or was incomplete. Moreover, errors can occur in the processing steps as well, such as the wrong reagents being used or the wrong tests being performed. It is, therefore, desirable that laboratories implement systems, methods, and apparatus for maintaining the fidelity of their work, i.e., the proper analysis on the right sample and being able to report the same to the person who ordered the test.
To prevent errors of this kind, elaborate and costly systems of paperwork are used. Current systems may also use barcodes to identify the samples, such as patient information, as well as barcodes to carry other information, such as instructions about tests to be run. Often, this leads to a need to use multiple barcodes, each directing a specific function or holding information related to the sample. Because of the limited space available for these barcodes on sample containers or of the risk of confusion, one barcode may need to be placed over another in order to run the slide on more than one test. Alternatively, the old barcodes can be removed; however, it must be done without removing the barcode holding needed information, such as the patient information. Moreover, since most barcodes look similar, the more widespread the use of barcodes for each specific task or bit of information, the greater the likelihood of placing the wrong barcode on a sample, possibly misidentifying the sample and/or providing incorrect instructions for handling the sample.
Once a sample is collected, it is labeled, or otherwise identified, and sent to a laboratory for further processing. For example, in a hospital setting, a health care provider will collect samples from a patient. These samples might be biopsies (pieces of tissue removed surgically) or other samples from a person including samples of blood, urine, stool, scrapings from the skin, or any other location, hair etc. Typically one or more samples are bagged, labeled and sent to a laboratory with a work order that specifies what diagnostic tests are to be performed on them. The laboratory may be in the same building as where the sample was collected or it may be in another facility or even in another country. The laboratory may even forward the sample or a portion of the sample to yet another laboratory to do tests it cannot perform.
Once the sample arrives at the laboratory to be processed, the sample is prepared for analysis. For example, the sample can be taken to a grossing station. At the grossing station, the sample is removed from its container and the desirable portions of the sample can be extracted and placed in the appropriate setting for further processing. For example, the portions can go into small baskets called cassettes, which are used to carry the samples while they are fixed and embedded in wax. Once embedded, the samples can be sliced on a microtome and placed on slides. Since the slices are very thin (microns) many slides can potentially be made from one cassette. While slides are described, other receptacles for holding the sample are used in the laboratory, and they are contemplated for use herein, for example, tubes, cuvettes, biochips, and microplates, to name just a few. In each case, the source of the extracted portions of the sample must be correctly identified.
From here, the slides with the sample may go on to be specifically treated for the test to be run on it, such as staining with reagents. The types of reagents used will depend upon the test that is to be performed. Slides can be stained with a variety of chemicals that will make relevant cells, germs or other structures visible. Once the slides are processed, they can be read by an automated microscope, such as an ACIS (Automated Cell Image System) or by an individual through a microscope. A pathologist can examine the slide or the image of the slide and issue a diagnostic report that can be sent back to the clinician. Throughout this process, the user should ensure that all the slides are identified properly and that the proper test is being performed.
A fluid sample can be processed in a similar manner except that, instead of the grossing and microtome steps, the cells in the sample can be spun down with a centrifuge and transferred to a slide. Smears may be applied directly to a slide by hand. There are a number of other patented and non-patented methods of getting cells onto a slide that could be used in conjunction with the system described herein.
SUMMARY
In one general aspect, the invention contemplates a laboratory or a network of laboratories equipped with readers (scanners) such as barcode readers, magnetic strip readers, keyboards, or a similar device that can “input” data directly or indirectly into a computer or computer system, such as Optical Character Recognition (OCR) readers. It is envisioned that these scanners can be located at desired area in the laboratory or throughout the facility, e.g., at one or more of the following areas, including but not limited to, the grossing stations, microtome, reagent dispensing stations, automated cell image analysis stations, or storage areas.
In another general aspect, the samples are assigned a unique identifier composed of numbers, letters, and/or symbols. The identifier can be in human readable text and/or computer readable text. In one embodiment, the identifier is a universal unique identifier (UUID). These identifiers are unique across both space and time. Use of UUIDs does not require a registration authority for each identifier; instead, it uses a unique value over space for each UUID generator. Methods and algorithms for generating unique identifiers are known in the art, for example, UUIDLib is a Macintosh shared library that generates UUID identifiers. Global unique identifiers (GUID) are used by Microsoft to identify anything related to its system. One source of information about unique identifiers is the world wide web. The unique identifier can be read by a human and/or by a computer (e.g., scanners). In other embodiments, the identifiers are generated from one source that dispenses identifiers sequentially. In still other embodiments, algorithms used in computers generate a unique 128 bit number. Other methods of generating a unique identifier are known to those skilled in the art.
Once assigned, the unique identifier remains associated with the particular sample. Other samples derived from the original sample, such as when the sample is being processed at the grossing station, are assigned their own unique identifier. In one embodiment, the unique identifier is merely an identifier. In another embodiment, the unique identifier can also provide information about the identifier, such as the location of where and/or when the identifier was assigned, based upon a characteristic of the identifier. For example, identifiers that begin with 01 can be designated to have originated from a particular facility. In certain embodiments, the identifier does not hold any information pertaining to the sample. In other words, the identifier does not hold any information about the source of the sample, the tests to be run on it, or what other samples may be related to it. The unique identifier can be read by scanners or otherwise inputted into a computer, such as by hand. Once in the computer, the information can be transmitted to a database.
In another general aspect, a central database can be utilized to house all the information associated with the sample. The central database can store any and all information about the sample, source information, the tests to be performed, the results obtained from the tests, and the location of the sample, to name just a few examples of the type of information. The data in the central database can be updated each time new information is received. In certain embodiments, the central database receives and stores information about the sample, such as the name of the patient (source) and other identifying information, type of sample, when collected, and who collected it. The central database can also receive and store information about what tests are to be performed. It can also receive and store information about when it was checked into the lab. The central database can also receive and store information about how the sample was processed, what reagents were used and when it was done, and whether there are other samples prepared from the original sample and information relating to them, or otherwise linking the data about the original sample and the data from all samples derived from it. The central database can receive and store the results of the tests. The central database can also receive and store information about additional tests to be run or changes to existing orders. The central database can also allow approved users to access this information. In certain embodiments, the data can be accessed from a terminal in close proximity to the laboratory or the database, or from a remote location, over the LAN, WAN, VPN or the world wide web.
In another general aspect, the central database may be in communication with the readers or scanners for inputting the unique identifies, such as the barcode readers. The central database may be in communication with the equipment in the laboratory, such as the microtome, centrifuge, reagent dispensers, and automatic image analyzer, to name just a few pieces of equipment found in laboratories. The readers or scanners may also be in communication with the equipment, so that all three, scanners, equipment, and the central database are in communication with each other.
In another general aspect, the invention contemplates a computer system including a database having records to the identity of a biological sample collected from a subject and the identity of a diagnostic analysis to be performed on the biological sample and a remote user interface, such as readers, scanners, display screens, printers and computer terminals, capable of receiving and/or sending the records, for use in matching the biological sample with the diagnostic analysis to be performed on the biological sample.
In another general aspect, the invention contemplates a computer-assisted method for processing a biological sample including: using a programmed computer including a processor, an input device, and an output device, including inputting into the programmed computer, through the input device (readers, scanners, mouse, keyboard), data including the identity of a biological sample collected from a subject and the identity of a diagnostic analysis to be performed on the biological sample; determining, using the processor, the parameters of the diagnostic analysis; and outputting, to the output device, display screens or printers, the results of the diagnostic analysis.
In another general aspect, the invention includes methods for the automated analysis of a biological sample, including the steps of: providing a user with a mechanism for electronically communicating the identity of a biological sample collected from a subject and the identity of a diagnostic analysis to be performed on the biological sample; providing the biological sample with a unique identifier; providing the diagnostic analysis with a unique identifier; optionally providing the user with an opportunity to communicate a desired modification to the diagnostic analysis; allowing the user to transmit any of the above identified information to a server; allowing a second user to obtain the information from the server; correlating the information with the biological sample; performing the diagnostic analysis on the biological sample; and inputting into a programmed computer, through an input device, data including the results of the diagnostic analysis.
In another general aspect, the invention contemplates methods of selecting a therapy for the patient based upon: obtaining a patient sample from a caregiver; identifying a diagnostic profile to be performed on the sample; providing a caregiver with a mechanism for electronically communicating the identity of the biological sample collected from the patient and the identity of the diagnostic profile to be performed on the biological sample to a server, wherein the patient and profile are given a unique identifier; and allowing a second user to obtain the information from the server. A diagnostic profile may include a series of tests to be run on a particular sample.
In another general aspect, equipment useful for the system can include a grossing station that can read the barcode, or otherwise input the identifier into the system. For example, a scanner reads the barcode on a sample bag and a list of tests to be done on the sample, to provide guidance to the pathologist doing the grossing, is displayed on a screen. It may also be able to print out the barcodes for the appropriate number of cassettes, sample tubes, or other sample holders. If the cassettes and tubes are prelabled with a barcode, the pathologist can scan the labels to associate the barcodes with the cassettes or tubes of samples. This method allows for the automatic entry of information to the database to maintain the linkage between the patient and sample and the intermediate sample carriers (cassettes and tubes).
Other equipment includes a microtome with a scanner that can read a barcode or other identifying mark. The scanner can read the barcode on the cassette or tube (i.e., the block of sample) and allow the database to transmit to the pathologist or technician information about what tests are to be performed on this block of sample and/or how many slides are to be prepared from the block of sample. It can then print out the required number of barcodes for each of the slides to be prepared. An autostainer and an automated microscope that can read the identifier and extract information from the database as well as transmit information to the database are contemplated as well.
The scanner, or similar device to input the identifier, such as a barcode reader, can be a component separate from the laboratory equipment or it can be integrated into the laboratory equipment. Even if the scanner is a component separate from the equipment, it may still be in communication with the equipment.
In still another aspect, a sample is assigned a unique identifier. In one embodiment, the unique identifier is in the form of a barcode. Information related to the sample is received by the central database and associated with the unique identifier. The sample is sent to the laboratory for processing. The laboratory is equipped with scanners for inputting the unique identifier, in this case barcode readers. At the laboratory, the user may scan the barcode of the sample to log in when the sample arrived in the laboratory. This information is received and stored by the central database. The user may take the sample to the grossing station. At the grossing station, the user may scan the barcode into a barcode reader. The unique identifier is received by the central database and it is noted that the sample is at the grossing station at a particular time. The database may also transmit to the user, for example on a display panel at the grossing station, information about how the sample is to be prepared.
The sample may then arrive at the microtome. The identifier of the sample is scanned, and the time and location is received by the central database. The central database can then transmit more information about processing the sample. For example, an order in the central database may state that five different slides of the sample are to be prepared from the original sample. There is, of course, no limitation on the number of slides that can be prepared. The central database may transmit this information to the user at the grossing station and may even automatically print out labels with unique identifiers to affix to each of the five slides with the biological sample, or the system may utilize another means of affixing the unique identifier to the slide, such as by encoding it by laser, stamping it, or encoded magnetic strip. Alternatively, the user may place the samples on slides already assigned a unique identifier. The central database stores information about the new samples (e.g., that the samples associated with the new five identifiers are derived from the original sample, when they were prepared, and other useful information). This recordkeeping can be done with very little input from the user.
The slides can now be prepared for their specific test. The central database stores the information about how the sample is to be prepared and what tests are to be run on them. At each station, e.g., sample fixer, reagent dispenser, or analyzer, the sample can be scanned. This would log in the sample providing information such as location and time to be stored in the central database. It can also ensure that the slide is being processed properly. For example, if the sample is at the wrong station, there might be a display indicting such, the station may refuse to process the slide, and/or the information is logged so that one looking at the history of the slide would know where the error occurred. All this can be recorded without the need for the user to take any notes.
Once the slide is processed and the test results transmitted to the central database, the slides may then be put aside for storage. At the storage area, the user can scan the slide to log it in, providing a time and location for the slide in the central database, and set it aside. If a loose slide is found, the unique identifier can be scanned into the system to allow the central database to transmit the identifying information back to the user, as well as logging in the information of when and where the slide was found by noting which scanner read the barcode and when it happened. Use of unique identifiers as described herein allows for real time tracking as well as a convenient way to create a complete history of the slide with minimal input from a user. It is further contemplated that a network of laboratories can be similarly equipped so that samples can be shared easily and effectively.
The invention may further include one or more of the following embodiments. The unique identifier can be assigned at the moment the sample is removed from the patient's person. The unique identifier may be assigned when the sample reaches the laboratory. It is further contemplated that scanners may be found throughout the facility, in areas not associated with equipment in the laboratory, such as a user's desk. In addition, while slides are the subject of this example, they are only one example of the types of devices that can be used in the examination of biological samples. Any device used to process biological samples, such as tubes, cuvettes, vials, cassettes, biochips, and microplates, are also contemplated in the practice of the invention. Moreover, a user can be assigned an identifier. She can scan in her identification when the sample is scanned so that the central database can record not only when and where the sample was scanned, but also who scanned it in.
In another general aspect, the invention contemplates labels designed to hold information used in a laboratory equipped with scanners or other devices for inputting data into the system. The information may be patient information and/or information concerning the tests to be run. The presence of the scanners reduces the need for a user to record the data, as well as providing an efficient way to track the slides.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description, drawings, and the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram of an exemplary organization of one embodiment of the invention.
FIG. 2 is a diagram of an exemplary architecture of one embodiment of the invention.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
In one aspect, a system for tracking the relevant samples and information is provided. It is designed to work for a single laboratory or for a network of laboratories and clients. In other aspects, the methods and apparatus for tracking samples and information are also provided. FIG. 1 shows one example of the flow of samples and information.
In this example, the identifier is a printed barcode number and the sample is a tissue to be analyzed under a microscope.
1) A sample bag is received at laboratory receiving 110 . The sender may have already used an accession workstation 180 , to enter information into the central database 200 about the sample, such as information about the source of the sample, patient information, the tests required, and the barcode number of the bag and each sample container. The accession workstation 180 can be local or it can be at a remote location, such as in the surgery room where the sample may have been collected. Inputting information can also be done at the management workstation 120 . The management workstation 120 can also allow configuration of all the instruments, as well as the laboratory information system (LIS), provide additional information or update information already in the system, and direct the processing of the sample.
2) A receiving clerk reads the bag barcode into the system. The clerk may also read the barcode on the package. This information could be linked to the delivery service so that the receipt of the package is automatically acknowledged to the delivery service. The central database finds the record of the shipment and displays a list of the expected contents for the clerk to check. If the individual samples do not have their own barcodes, the workstation can print them (as well as record the numbers).
3) At the grossing station 130 , the technician shows the sample barcodes to the barcode reader and a screen displays a list of how the samples are to be divided for the requested tests. Note that no paper documentation needs to follow the sample because from the sample's unique identifier, the database can send, receive, and store the needed information. The sample may be subdivided into the needed number of vials or cassettes, as the case may be. If these vials or cassettes are prelabeled with unique barcodes, the operator shows them to the reader when he is finished to note that they are in use, otherwise the system assigns unique identifies to be affixed to the vial or cassettes. The unique identifiers can be affixed in any way known in the art, such as by affixing a label to the slide or imprinting it into the slide.
4) At the microtome 140 , the same process is repeated, the operator shows the barcode of the cassette to the reader and a list appears of how many samples need to be cut for placement onto slides. Again, if the slides are not prelabeled, the station prints out the barcodes for the slides.
5) The labeled slides are loaded into an autostainer 150 , which reads the barcodes and checks the central database to see what stains need to be applied to each slide.
6) Next, the slides are loaded in the automated microscope 160 , which reads the barcode to see what magnification and other parameters to use to scan the slide. Automated microscopes include ACIS (automated cell image system) a device that scans the slides and presents images to the pathologist along with image processing tools to help in the diagnostic process. Apparatus for the automated analysis of samples are known in the art, for example, they are described in U.S. Pat. Nos. 6,215,892; 6,330,349; 6,418,236, the contents of which are incorporated by reference in their entirety.
7) Finally, an image is displayed to a pathologist who uses the image processing features of the review workstation 170 to study the image and arrive at a diagnosis.
These diagnostic quality review workstations 170 display the images captured by the image acquisition system. In order to assist the pathologist in interpreting a medical image, a view station may be able to perform a variety of image processing operations on the medical image. For example, the pathologist at the view stations may invoke algorithms to perform densitometry on selected regions of the medical image in order to identify concentration of a particular analyte within the tissue sample. Other image processing operations are useful for finding objects within the image such as the nuclei of the cells, computing an integrated optical density for the nuclei of the cells and reporting the number of molecules per cell. Most image processing operations output a fixed number (score), often falling within a predetermined range. Demographic data about the patient, which was irrelevant to the processing of the slide, might be fetched from the central database and displayed at this point.
Due to the size of some medical images for a single tissue sample, typically remote viewing is unworkable if there are bandwidth constraints. Compression algorithms can produce an image suitable for transmission, but the data lost during compression can lead to inaccurate results from the image analysis operations.
A system can be utilized in which a remote review workstation 170 is communicatively coupled to an image server and receives a compressed version of a source medical image. The remote review workstation 170 can uncompress and display the received medical image. The compressed medical image can be transmitted over a global packet-switched network such as the Internet. The remote review workstation 170 can select a region of the displayed medical image as a function of input received from a user. Based on the input, the remote review workstation 170 can transmit region information, such as a series of pixel coordinates, back to the image server. The image server can then apply image analysis operations to a region of the source medical image that corresponds to the selected region of the compressed medical image. In this manner, the data loss that occurs during image compression does not affect the image analysis operations. As such, the image analysis operations can produce more accurate results than if the operations were applied by the remote review workstation 170 on the compressed image. U.S. patent application Ser. No. 09/542,091, filed Apr. 3, 2000, the contents of which are incorporated by reference, describes a system in which images are viewed at a site remote from the location of the ACIS microscope that collects the images. It further describes a method for carrying out the image processing at a remote site that has uncompressed versions of the images while transmitting compressed images for human viewing. Other means for viewing large images electronically are known to the skilled artisan. Therefore, in situations where the review workstation 170 is connected to the system with a limited bandwidth, e.g., over the WAN, one method for transmitting data involves generating a compressed medical image, transmitting the compressed medical image to a remote view station for display, selecting a region of the displayed medical image, and applying image analysis operations to a region of the source medical image corresponding to the selected region of the compressed medical imaged. The image displayed for review might be compressed, but the user's requests for image processing or scoring algorithms might be sent back to the central database for execution on uncompressed images. However, if there is no need to review the images from a remote location, e.g., over the LAN, then there is no reason not to send an uncompressed image.
An optional feature of the system can include users being assigned their own identifying string, such as a barcoded badge. They can then log onto any one of the stations by scanning their barcoded badge. One method of utilizing the feature is to have the user log onto the station when they log in a slide. The system can then provide information about who has handled the slide at any given stage of its processing. This system can also be used to assess the quality and quantity of work being handled by an individual.
Still other features of the system can include apparatus adapted for use in the system. For example, an autostainer may be designed to use its barcode reader to read IDs on the bottles of reagent to track which slides are stained with which lot of reagent. A scanner, such as a barcode reader, on a refrigerator or other sample storage space can be used to check in or check out samples for tracking purposes. An undedicated reader, for instance at a supervisor's station, could be used to identify a loose slide. It is contemplated that other equipment generally found in laboratories, not herein described, can also be adapted to transmit information to and/or receive information from the database to track and provide information about the sample or the process it undergoes.
The system takes advantage of being able to assign unique identifiers, and utilize scanners that read them, to faithfully transmit the information to a database. Each time a slide or sample passes through some station, the database can record this event. It is, therefore, possible to provide more detailed reports and tracking information with less effort then can be done with paper based systems. For instance, if a slide is missing, the database can provide information about which station it was last logged in, when it was logged in and who logged it in, without a user having written any of this information into the system. If a batch of reagent becomes suspect, the database can provide information about all the samples that used the reagent and the test results from that use. If a stat (rush) result is needed on a sample, the database can provide in real time information about where the sample is in the process.
The system may utilize a centralized database. One of the benefits of using a centralized database is that it does not matter if some steps in the processing of the sample occur at one facility and some at another. Since all the information is being stored in one database, someone accessing the database will see only the seamless processing of the sample. Furthermore, if a sample is sent from one facility to another, no paperwork need accompany it as long as the sample has its unique identifier. When the sample arrives at the new facility, its unique identifier can be scanned to log it in, to indicate its new location and when it arrived.
FIG. 2 shows a block diagram of a system in which clients (who have review and accessioning workstations 310 ) are sending samples to reference laboratories 320 who are preparing slides and running them on an automated cell image system (ACIS). All of them are connected via the global Internet 330 to a data center 340 , which is storing all the information. Table 1 shows an exemplary division of work in the application of an exemplary system.
TABLE 1
RL = CCIC reference lab 320
Client = CCIC client
Sequence of
CW = Client's workstation 310
Operation:
DC = CCIC data center 340
Manual Event
Automatic Event
For each Slide:
Client enters acces-
DC captures accessioning information
sioning info
DC sends accessioning info to RL
Client sends
DC center captures shipping information
samples
DC notifies RL to expect shipment
RL receives
DC captures receiving information
shipment
RL prepares slides
RL ACIS sends lossless compressed images to DC
RL scans slides on
RL ACIS deletes images
ACIS
DC sends lossy compressed images to client
DC notifies Client slides are ready for review
Client uses review
CW sends region coordinates to DC
analysis program to
DC scores regions and sends scores back to CW
view slides and
select regions
Client releases cases
CW prints report
DC enters billing data in database
DC archives images if archive fee paid then deletes
from hard disk
At any time:
Client requests case
CW queries DC and displays results
status on status dis-
[if the RL had barcode readers at grossing and
play on Client
sectioning, the display could indicate the exact stage
workstation
of each slide]
Client requests re-
CW queries DC on availability of operator
review of archived
CW informs client how long tape mount will take
case (if they have
this service)
DC operator mounts
DC sends notification to Client
tape
Client reviews case
Although barcodes are referred to here, any globally unique system of identifiers could be used, for instance letters and numbers if Optical Character Recognition (OCR) readers were used. An OCR system that can distinguish 80 symbols can detect 10 quintillion (a billion billion) different 10-character labels.
In the system, each label is unique and is used to identify the information sent to the database and/or retrieved from the database. This allows any part of the system (within one laboratory or in other facilities) to work on the samples or slides without having to re-label for use with different equipment or for different processing steps.
Other components of the system may include an autostainer and an automated microscope that reads the same barcode and each extracts the information it needs from the database; a microtome with a barcode reader and printer, which can read the barcode on a cassette (block), look up in the database what tests are to be performed on slides cut from this block, and then print the required number of slide barcodes; and/or a grossing station that can read the barcode on a sample bag and display a list of tests to be done on this sample for the guidance of the pathologist doing the grossing. It would then either print the needed barcodes for the appropriate number of cassettes or sample tubes or otherwise encode the cassettes or samples. If they were prelabled it would read the labels. In either case, it would automatically make the required entries in the database to maintain the link between the patient, sample, and the intermediate sample carriers.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | Systems, methods, and apparatus are described for the handling of biological specimens for analysis. The systems, methods and apparatus are designed to reduce errors in misidentification, incorrect processing, and recordkeeping and reporting. The systems, methods, and apparatus can also provide real time tracking of samples at any stage, from collection to processing to analyzing to storage. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of and claims priority to U.S. patent application Ser. No. 14/454,635, filed Aug. 7, 2014, which claims priority to U.S. Provisional Application No. 61/863,401 filed Aug. 7, 2013, which are hereby incorporated by reference herein in their entirety.
BACKGROUND
[0002] Diagnostic tests for various diseases can provide important information for successful treatment. Diagnostic assays are used to detect pathogens, including bacteria and viruses. Many standard diagnostic assays, such as cell cultures and genetic testing with PCR amplification, require sending samples to labs and have long turnaround times of several days or weeks. Many patients, in such cases, do not return to the care provider to receive the results or treatments, and in some cases, the long turn-around can compromise the ability to properly treat the condition.
[0003] While some assays have been automated, many still require significant expertise or training. In many currently available systems the cells to be tested are not adequately processed prior to applying the tests, which can introduce inaccuracies. Alternative systems and methods for diagnostics, could be beneficial for improved patient outcomes, particularly in point of care applications.
SUMMARY
[0004] This application is directed to systems, devices and methods for preparing materials and samples to be used within a point of care device to improve its use in detecting target molecules within a patient's sample. In general, the systems, devices and methods relate to approaches to integrating agents and materials that can be used to prepare samples and react with the samples to detect target molecule. To provide an overall understanding of the systems, devices, and methods described herein, certain illustrative embodiments will be described. It is to be understood that the systems, devices, and methods disclosed herein, while shown for use in diagnostic systems for bacterial diseases such as Chlamydia, may be applied in other applications including, but not limited to, detection of other bacteria, viruses, fungi, prions, plant matter, animal matter, protein, RNA sequences, DNA sequences, as well as cancer screening and genetic testing, including screening for genetic traits and disorders.
[0005] Disclosed herein are systems, devices, and methods for detecting the presence of a pathogen in a biological host, such as in a point of care setting. In certain aspects, materials and methods improve point of care devices by providing pre-loaded, preferably dried, agents for performing one or more of sample lysis and signal enhancement inside the device.
[0006] The systems, devices, and methods described herein may be used for diagnosing a disease in a living organisms such as a human or animal. For example, Chlamydia is a bacterial disease that afflicts humans and is caused by the bacteria Chlamydia trachomatis. A caretaker, such as a nurse or physician, may obtain a sample from a patient desiring to receive a diagnosis for this disorder. For example, the caretaker may use a medical swab to wipe the surface of the vagina, to thereby obtain a biological sample of vaginal fluid and vaginal epithelial cells. If the patient is carrying the Chlamydia trachomatis bacteria, the bacteria would be present in the sample. Additional markers specific to the human genome would also be present. The caretaker or technician then uses the systems, devices, and methods described herein to detect the presence or absence of the bacteria or other pathogen, cell, protein, or gene in the sample.
[0007] In general, the diagnostic systems disclosed herein use probe molecules, preferably protein nucleic acid probes, to detect components within a sample that have matching genetic sequences to the nucleotide sequences of the probe. In that way, bacteria or virus other components of the sample can be detected. Under appropriate conditions, the probe can hybridize to a complementary target marker in the sample to provide an indication of the presence of target marker in the sample. In certain approaches, the sample is a biological sample from a biological host. For example, a sample may be tissue, cells, proteins, fluid, genetic material, bacterial matter or viral matter a plant, animal, cell culture, or other organism or host. The sample may be a whole organism or a subset of its tissues, cells or component parts, and may include cellular or non-cellular biological material. Fluids and tissues may include, but are not limited to, blood, plasma, serum, cerebrospinal fluid, lymph, tears, saliva, blood, mucus, lymphatic fluid, synovial fluid, cerebrospinal fluid, amniotic fluid, amniotic cord blood, urine, vaginal fluid, semen, tears, milk, and tissue sections. The sample may contain nucleic acids, such as deoxyribonucleic acids (DNA), ribonucleic acids (RNA), or copolymers of deoxyribonucleic acids and ribonucleic acids or combinations thereof. In certain approaches, the target marker is a nucleic acid sequence that is known to be unique to the host, pathogen, disease, or trait, and the probe provides a complementary sequence to the sequence of the target marker to allow for detection of the host sequence in the sample. Examples of probes and their use in electrochemical detection assays are disclosed in in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/US12/024015, and U.S. Provisional Application No. 61/700285, which are hereby incorporated by reference herein in their entireties.
[0008] In certain aspects, systems, devices and methods are provided to perform processing steps, such as purification and extraction and signal amplification, on the sample. Analytes or target molecules for detection, such as nucleic acids, are sequestered inside of cells, bacteria, or viruses. The sample is processed to separate, isolate, or otherwise make accessible, various components, tissues, cells, fractions, and molecules included in the sample. Processing steps may include, but are not limited to, purification, homogenization, lysing, and extraction steps, as well as signal amplification. The processing steps may separate, isolate, or otherwise make accessible a target marker, such as the target marker in or from the sample, and they may also or in addition help amplify the signal detected by the diagnostic system.
[0009] In certain approaches, the target marker is genetic material in the form of DNA or RNA obtained from any naturally occurring prokaryotes such, pathogenic or non-pathogenic bacteria (e.g., Escherichia, Salmonella, Clostridium, Chlamydia, etc.), eukaryotes (e.g., protozoans, parasites, fungi, and yeast), viruses (e.g., Herpes viruses, HIV, influenza virus, Epstein-Barr virus, hepatitis B virus, etc.), plants, insects, and animals, including humans and cells in tissue culture. Target nucleic acids from these sources may, for example, be found in biological samples of a bodily fluid from an animal, including a human. In certain approaches, the sample is obtained from a biological host, such as a human patient, and includes non-human material or organisms, such as bacteria, viruses, other pathogens.
[0010] In one aspect, a biological sample is processed to release or otherwise make accessible, the target molecules or analytes of interest, such as the target marker and control marker. For example, analytes, such as nucleic acids, may normally be sequestered inside of cells, bacteria, or viruses from which they need to be released prior to characterization. For example, mechanical approaches including, but not limited to, sonication, centrifugation, shear forces, heat, and agitation may be used to process a biological sample. Additionally or alternatively, chemical methods including, but not limited to, surfactants, chaotropes, enzymes, or heat may be applied to produce a chemical effect.
[0011] U.S. Application No. 61/700,285 describes diagnostic devices and systems that include an on-board lysis chamber for applying lysis techniques to a biological sample to release target markers from cells within the sample, prior to analyzing the contents of the sample. The contents of that application are hereby incorporated by reference. Lysis techniques disrupt the integrity of a biological compartment such as a cell such that internal components, such as RNA, are exposed to and may enter the external environment. Lysis procedures may cause the formation of permanent or temporary openings in a cell membrane or complete disruption of the cell membrane, to release cell contents into the surrounding solution. For example, a modulated electrical potential can be applied to a sample to release nucleic acids, and in particular, RNA, into the sample solution. Electrical lysis techniques are described in further detail in PCT application No. PCT/U.S.12/28721, the contents of which are hereby incorporated herein by reference. The device and systems of those earlier filed applications can also be modified to include a lysing chamber that uses a chemical lysing agent on board the device. A brief description of these techniques, as applied to the current system, is provided below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The foregoing and other objects and advantages will be appreciated more fully from the following further description thereof, with reference to the accompanying drawings. These depicted embodiments are to be understood to as illustrative and not as limiting in any way:
[0013] FIG. 1 depicts a lysis chamber that is configured to be integrated within a point of care device
[0014] FIG. 2 depicts a system for preparing and analyzing a biological sample that can be configured within a point of care device.
[0015] FIGS. 3A - FIG. 4 depict embodiments of an on-board lysing chamber structured to lyse biological samples using chemical lysing agents and which can be integrated into the system of FIG. 2 .
[0016] FIG. 5A depicts a cartridge system for receiving, preparing, and analyzing a biological sample.
[0017] FIG. 5B depicts an embodiment of a cartridge for an analytical detection system.
[0018] FIG. 6 depicts an automated testing system to provide ease of processing and analyzing a sample.
[0019] FIG. 7 depicts a hand-held point of care device.
[0020] FIG. 8 depicts in further detail components of this hand-held system illustrated in FIG. 8 .
[0021] FIGS. 9A-9E depict the use and operation of the system or the hand-held device illustrated in FIG. 8 .
[0022] FIG. 10 illustrates an example performed using the system.
DETAILED DESCRIPTION
[0023] FIG. 1 depicts a lysis chamber that is configured to be integrated within a point of care device. The example shown in FIG. 1 is an electrical lysis chamber but as discussed below, can be modified to provide a chemical lysis chamber on-board the device. Chamber 1200 includes a first wall 1202 and a second wall 1204 defining a space 1206 in which a sample is retained. For example, a sample may flow through the space 1206 of the lysis chamber 1200 . Chamber 1200 also includes at least one lysing source (as shown, two lysing sources are included—a first electrode 1208 and second electrode 1210 ). First lysing source ( 1208 ) and second lysing source ( 1210 ) are separated by a spacing 1212 .
[0024] First source 1208 and second source 1210 may be electrical or chemical lysing sources. For example, electrodes may be used that are composed of a conductive material. For example, first source 1208 and second source 1210 may comprise carbon or metal electrodes including, but not limited to, gold, silver, platinum, palladium, copper, nickel, aluminum, ruthenium, and alloys. First source 1208 and second source 1210 may comprise conductive polymers, including, but not limited to polypyrole, iodine-doped transpolyacetylene, poly(dioctyl-bithiophene), polyaniline, metal impregnated polymers and fluoropolymers, carbon impregnated polymers and fluoropolymers, and admixtures thereof. In certain embodiments, first source 1208 and second source 1210 comprise a combination of these materials.
[0025] In certain embodiments, the spacing 1212 separates the first source 1208 and the second electrode 1210 by a range of approximately 1 nm to approximately 2 mm. In certain embodiments, the first electrode 1208 and the second electrode 1210 are inter-digitated electrodes. For example, the first electrode 1208 may have digits 1214 spaced between digits 1216 of the second electrode 1210 . The spacing 1212 can be composed of an insulating material to further localize the applied potential difference to the electrodes. For example, spacing 1212 may comprise silicon dioxide, silicon nitride, nitrogen doped silicon oxide (SiOxNy), paralyene, or other insulating or dielectric materials.
[0026] In the example of FIG. 1 , first source 1208 and second source 1210 are planar electrodes, over which the sample flows. For example, first electrode 1208 , second electrode 1210 , and spacing 1212 are coplanar to form a base within space 1206 of the chamber 1200 . First electrode 1208 and second electrode 1210 may also comprise other configurations, including, but not limited to, arrays, ridges, tubes, and rails. First source 1208 and second source 1210 may be positioned on any portion of chamber 1200 , including, but not limited to sides, bottom surfaces, upper surfaces, and ends. The lysis chamber 1200 , first source 1208 , second source 1210 , and spacing 1212 may have any appropriate length L. Although depicted as having the same length L in FIG. 12 , each component of the chamber 1200 may have a different length. In certain approaches, the length L of the chamber 1200 is between approximately 0.1 mm and 100 mm. For example, the chamber 1200 may have a length L of approximately 50 mm. Similarly, the lysis chamber 1200 , first source 1208 , second source 1210 , and spacing 1212 may have any appropriate width W. Each component of the chamber may have a different width. In certain approaches, the width w of the chamber 1200 is between approximately 0.1 mm and 10 mm. For example, the chamber 1200 may have a width W of 2 mm. The chamber 1200 is depicted as linear or straight, however, in certain approaches, the chamber 1200 includes turns, bends, and other nonlinear structures.
[0027] In certain approaches, lysing pulses (either electrical by electrical pulses or chemical, e.g., by depositing aliquots of chemical lysing agents into the lysing chamber) are applied as the sample continuously flows through chamber 1200 . Lysis pulses may also be applied while the sample is immobile in the chamber, or during agitation of the sample. In embodiments using electrical lysis, the total application time of the pulses is between about 1 second and 1000 seconds. In certain approaches, the pulses are applied for about 2-3 minutes. In certain approaches, the pulses are applied for about 20 seconds or less.
[0028] In certain embodiments, the lysis procedure controllably fragments analyte molecules, such as DNA and RNA. Fragmentation can advantageously reduce the time required to detect or otherwise characterize the released analyte. For example, fragmentation of an analyte molecule may reduce molecular weight and increase speed of diffusion, thereby enhancing molecular collision and reaction rates. In another example, fragmenting a nucleic acid may reduce the degree of secondary structure, thereby enhancing the rate of hybridization to a complementary probe molecule. For example, RNA from a cell lysed by the application of a modulated potential to first electrode 1208 and second electrode 1210 may have an average length of over 2,000 bases immediately upon lysis, but are rapidly cleaved into fragments of reduced length under continued lysing conditions. The average size of such fragments may be up to about between about 20% and about 75% of the size or length of the unfragmented analyte. In certain approaches, the analyte is a RNA. For example, fragmented RNA may have a significant portion of molecules with lengths between approximately 20 and approximately 500 base pairs. in certain approaches, pulses are modulated to simultaneously lyse and fragment the sample and analytes. Additionally or alternatively, a second set of lysing (e.g., electrical or chemical) pulses may be applied and configured to provide specific, controlled fragmentation. For example, a first set of pulses may applied to provide lysis, and a second set of pulses may be applied to provide fragmentation. In certain approaches, the first pulse set for lysis and second pulse set for fragmentation are alternated.
[0029] FIG. 2 depicts a system for preparing and analyzing a biological sample that can be configured within a point of care device. System 1300 includes a receiving chamber 1302 , a first channel, 1304 , a lysis chamber 1306 , a second channel 1308 , an analysis chamber 1310 , and a third channel 1312 . Other processing chambers and channels may also be included. In practice, a user obtains a sample from a biological host and places the sample in receiving chamber 1302 . While in receiving chamber 1302 , the sample may undergo processing, such as filtering to remove undesirable matter, addition of reagents, and removal of gases. The sample is then moved from receiving chamber 1302 through channel 1304 and into lysis chamber 1306 . The sample may be moved by applying external pressure with fluids or gases, for example, with a pump or pressurized gas. In certain embodiments, lysis chamber 1306 is similar to lysis chamber 1200 of FIG. 1 and can be configured with electrical lysing agents such as electrodes. In other embodiments the lysis chamber 1306 is configured as a receptacle that contains one or more lysing chemical agents (as exemplified in FIGS. 3A-10 below). Inside the chamber 1306 , the sample undergoes a lysis procedure, such as an electrical or chemical lysis procedure that lyses the cells in the sample to release the analytes contained therein, including genetic material. The lysis procedure may also cause fragmentation of the analytes released from the cells, such as RNA, which serve as target markers and control marker.
[0030] FIGS. 3A - FIG. 4 depict embodiments of an on-board lysing chamber 1306 structured to lyse biological samples using chemical lysing agents and which can be integrated into the system of FIG. 2 . FIG. 3A depicts the chamber 1306 with inlet channel 1304 and outlet channel 1308 , as per FIG. 2 . Inside chamber 1306 is a compartment 102 that contains a chemical lysing agent 100 . Preferably, the lysing agent 100 is in solid, dried form within the compartment 102 . In use, a sample to be tested flows into the chamber 1306 via inlet line 1304 (depicted as arrow A1) and while inside the chamber 1306 flows into the compartment 102 , whereupon the liquid sample inlet mixes with and dissolves the lysing agent 100 . For example, the inlet sample could be a sample buffer containing bacteria or virus that the system is intended to analyze. That buffer, upon contacting the agent 100 within the chamber 102 , then dissolves the agent 100 , changes the pH of the sample which starts a lysing reaction that chemically lyses the cells within the sample. Lysing the cells also exposes the cellular analytes and other components to the lysing agent, which fragments and denatures the components. Included among those components, the genetic material from the cell will fragment when contacting that lysing agent, creating smaller fragments that can more readily bind to probe sequences and are more readily detectable by the diagnostic system contained in the analysis chamber 1310 of FIG. 2 . To that end, lysis exposure time is preferably controlled so that the nucleic acids in the sample are partially fragmented within the sample by the changed pH. The sample, after mixing and at least partial dissolution with the lysing agent, then exits the chamber 1306 via outlet 1308 (as depicted by arrow A2).
[0031] FIG. 4 depicts an alternative embodiment of lysing chamber 1306 . As shown, the chamber 1306 includes two chambers 104 and 106 . Chamber 104 includes compartment 102 a that has lysing agent 101 ; for example, a strong base such as NaOH that can lyse cells and denature and fragment genetic and biologic materials in a sample. The lysing reaction that occurs within the compartment 102 a (which is similar to the compartment 102 of FIG. 3A ) is preferably quenched after a certain period of time to stop the lysis of the materials, leaving them in fragmented form so as to prevent ultimate destruction and degradation of the materials beyond their usability in the detection system. Accordingly, second chamber 106 includes a second compartment 102 b that houses a neutralizing agent 103 . For example, this neutralizing agent could be a strong acid that lowers the pH of the sample after it is lysed by the base 101 , to thereby prevent further degradation and denaturation of the genetic material in the sample. In use, the sample flows into the chamber 1306 via inlet line 1304 (see arrow A1) and undergoes lysis and denaturation of its contents within the first chamber 104 , and after which it flows into the second chamber 106 via intermediate line 1305 (arrow A2), whereupon the reaction is quenched. The resulting sample flows out of the chamber 1306 via outlet line 1304 (see arrow A3).
[0032] The lysis chambers of FIGS. 2-4 allow lysis of target sample cells (e.g., virus or bacteria) to be performed on-board the device, preferably by a strong chemical agent (e.g., a base, such as NaOH). A detergent (e.g., sodium dodecyl sulfate (SDS), TWEEN, TRITON-X) is preferably also used in combination with the chemical agent (e.g., the base in the lysing chamber 104 ). In certain implementations, a base is selected as the chemical agent and deposited by drying it to the interior walls of the compartment 102 a inside the lysis chamber 104 . In one mode during lysis, hydroxide from the strong base attacks and breaks down the cells inside compartment 102 a and allows the detergent to create holes in the cellular membrane, thus lysing the bacteria and releasing its genetic material (DNA, RNA) into solution. The released material is then at least partially fragmented by the hydroxide solution. This reaction can then be neutralized in compartment 102 b with the addition of a strong acid to prevent further degradation/ denaturation of the genetic material. In certain implementations this lysis process is performed within a single use, hand-held cartridge containing fully active, dried down, long-term room temperature stable reagents.
[0033] In one advantage, the on-board lysing approach also helps stabilize the lysis agent. Many acids are easily dried down and maintain full activity. However, challenges exist in drying down NaOH and maintaining its activity over a period of time. NaOH in its dry form rapidly takes on moisture from its environment and allows dissolved CO 2 to change the base into sodium bicarbonate. This is potentially problematic when drying down liquid NaOH as dissolved CO 2 concentrates in the liquid. The approach described herein provides an elegant solution to that problem, allowing the base to be stabilized for longer term storage or use.
[0034] In the point of case implementation, to prepare the cartridge, the lysing agent(s) are actively dried onto a surface within the interior of the chamber 1306 . In the case of FIG. 4 , active spots of both base and acid are dried on the floor of the separate compartments ( 102 a and 102 b ) of the cartridge. For example, dry powder NaOH and Citric Acid are dissolved in a degassed DiH 2 O, forming two different liquids, thus preventing NaOH exposure to any dissolved CO 2 . These two liquids are then spotted (in μl volumes) in the separate compartments 102 a and 102 b of the cartridge. These spots are rapidly dried down in a vacuum oven, limiting exposure to air and reactive CO 2 . In certain implementations, the cartridge may optimally be quickly packaged into nitrogen purged moisture barrier bags preventing further exposure to moisture and CO 2 . These procedures and conditions allow for the activity of NaOH to remain stable under long-term, room temperature environments.
[0035] Using dry lysis reagents in separate chambers allows the use of a neutral pH sample buffer (e.g., containing a detergent) to flow the sample through the system. The buffer (e.g., phosphate buffered saline solution) carries the sample into the chamber 102 a containing the dry NaOH spot. As the sample buffer containing bacteria flows into the chamber, the buffer dissolves the NaOH spot, raising the pH of the buffer which causes the cells in the sample to lyse. As explained further below, after lysis in chamber 102 a, the sample fluid is then pushed into the compartment 102 b containing the dry acid spot 103 . The acid spot 103 is dissolved and mixed as the solution enters the compartment 102 b via fluid line 1305 (arrow A2). This lowers the pH of the buffer, neutralizing it, and prevents further degradation of the genetic material. The sample, in the neutralized buffer, is then sent to the analysis chamber 1310 (described below) through channel 1308 . Analysis chamber 1310 may include any of analysis chambers 400 , 500 , 600 , 700 , 800 , 900 , 1000 , and 1100 described in U.S. Provisional Application No. 61/700285.
[0036] The lysing process partially degrades and denatures target genetic material, which helps facilitate direct hybridization detection of nucleic acids of a target when inside the analysis chamber. Smaller fragments of RNA and denatured genomic DNA bind more readily to probe sequences as the secondary structures of these molecules are destroyed. This allows for both increased diffusion of these molecules in solution (increasing hybridization events) and increases accessibility of these to sequences (unfolding) for hybridization. Using separate compartments for base lysis and acid neutralization, the flow from chamber to chamber can be timed (and the on-board fluid pump controlled accordingly) to optimize efficient lysis in concert with adequate degradation/denaturation of genetic material for optimal detection.
[0037] Referring back to FIG. 2 , the analysis chamber 1310 includes one or more sensors, such as pathogen sensors, host sensors, and non-sense sensors. The target markers and control markers can hybridize with probes on the respective sensors. The presence of the target markers and control markers are analyzed at the sensors, for example, with electrocatalytic techniques, as described previously in relation to FIGS. 1-3 . In certain approaches, the sample is then pumped through channel 1312 to additional processing, storage, or waste areas. Further examples of sensor structures and applications are disclosed in U.S. Provisional Application No. 61/700,285, incorporated by reference herein.
[0038] The dimensions, such as lengths, widths, and diameters of the sections of system 1300 can be configured to adjust for different volumes, flow rates, or other parameters. FIG. 2 depicts channel 1308 with diameter d7, analysis chamber 1310 with diameter d8, and channel 1312 with diameter d9. In certain approaches, diameters d7, d8, and d9 are each approximately the same to provide an even flow into and through analysis chamber 1310 . In certain approaches, diameters d7, d8, and d9 have different sizes to accommodate for different flow rates, the addition of reagents, or removal of portions of the sample.
[0039] In certain approaches, the systems, devices, and methods described herein are used for diagnosing a disease in a human. The systems, devices, and methods may be used to detect bacteria, viruses, fungi, prions, plant matter, animal matter, protein, RNA sequences, DNA sequences, cancer, genetic disorders, and genetic traits. For example, the disorder Chlamydia is a bacterial disease caused by the bacteria Chlamydia trachomatis. A caretaker, such as a nurse or physician, may obtain a sample from a patient desiring to receive a diagnosis for this disorder. For example, the caretaker may use a medical swab to wipe a surface of the vagina, to thereby obtain a biological sample of vaginal fluid and vaginal epithelial cells. If the patient is carrying the Chlamydia trachomatis bacteria, the bacteria would be present in the sample. Additionally, markers specific to the human genome would also be present. The caretaker or technician may then use the systems, devices, and methods described herein to detect the presence or absence of the bacteria or other pathogen, cell, protein, or gene.
[0040] The systems, devices, methods, and electrode and lysis zone embodiments described above may be incorporated into a cartridge to prepare a sample for analysis and perform a detection analysis. FIG. 5A depicts a cartridge system for receiving, preparing, and analyzing a biological sample. For example, cartridge system 1600 may be configured to remove a portion of a biological sample from a sample collector or swab, transport the sample to a lysis zone where a lysis and fragmentation procedure are performed, and transport the sample to an analysis chamber for determining the presence of various markers and to determine a disease state of a biological host.
[0041] The system 1600 includes ports, channels, and chambers. System 1600 may transport a sample through the channels and chambers by applying fluid pressure, for example with a pump or pressurized gas or liquids. In certain embodiments, ports 1602 , 1612 , 1626 , 1634 , 1638 , and 1650 may be opened and closed to direct fluid flow. In use, a sample is collected from a patient and applied to the chamber through port 1602 . In certain approaches, the sample is collected into a collection chamber or test tube, which connects to port 1602 . In practice, the sample is a fluid, or fluid is added to the sample to form a sample solution. In certain approaches, additional reagents are added to the sample. The sample solution is directed through channel 1604 , past sample inlet 1606 , and into degassing chamber 1608 by applying fluid pressure to the sample through port 1602 while opening port 1612 and closing ports 1626 , 1634 , 1638 , and 1650 . The sample solution enters and collects in degassing chamber 1608 . Gas or bubbles from the sample solution also collect in the chamber and are expelled through channel 1610 and port 1612 . If bubbles are not removed, they may interfere with processing and analyzing the sample, for example, by blocking flow of the sample solution or preventing the solution from reaching parts of the system, such as a lysis electrode or sensor. In certain embodiments, channel 1610 and port 1612 are elevated higher than degassing chamber 1608 so that the gas rises into channel 1610 as chamber 1608 is filled. In certain approaches, a portion of the sample solution is pumped through channel 1610 and port 1612 to ensure that all gas has been removed.
[0042] After degassing, the sample solution is directed into lysis chamber 1616 by closing ports 1602 , 1634 , 1638 , and 1650 , opening port 1626 , and applying fluid pressure through port 1612 . The sample solution flows through inlet 1606 and into lysis chamber 1616 . In certain approaches, system 1600 includes a filter 1614 . Filter 1614 may be a physical filter, such as a membrane, mesh, or other material to remove materials from the sample solution, such as large pieces of tissue, which could clog the flow of the sample solution through system 1600 . Lysis chamber 1616 may be lysis chamber 1200 or lysis chamber 1306 described previously. When the sample is in lysis chamber 1616 , a lysis procedure, such as an electrical or chemical lysis procedure as described in the embodiments above, may be applied to release analytes into the sample solution. For example, the lysis procedure may lyse cells to release nucleic acids, proteins, or other molecules which may be used as markers for a pathogen, disease, or host. In certain approaches, the sample solution flows continuously through lysis chamber 1616 . Additionally or alternatively, the sample solution may be agitated while in lysis chamber 1616 before, during, or after the lysis procedure. Additionally or alternatively, the sample solution may rest in lysis chamber 1616 before, during, or after the lysis procedure.
[0043] Electrical lysis procedures may produce gases (e.g., oxygen, hydrogen), which form bubbles. Bubbles formed from lysis may interfere with other parts of the system. For example, they may block flow of the sample solution or interfere with hybridization and sensing of the marker at the probe and sensor. Accordingly, the sample solution is directed to a degassing chamber or bubble trap 1622 . The sample solution is directed from lysis chamber 1616 through opening 1618 , through channel 1620 , and into bubble trap 1622 by applying fluid pressure to the sample solution through port 1612 , while keeping port 1626 open and ports 1602 , 1634 , 1638 , and 1650 closed. Similar to degassing chamber 1608 , the sample solution flows into bubble trap 1622 and the gas or bubbles collect and are expelled through channel 1624 and port 1626 . For example, channel 1624 and port 1626 may be higher than bubble trap 1622 so that the gas rises into channel 1624 as bubble trap 1622 is filled. In certain approaches, a portion of the sample solution is pumped through channel 1624 and port 1626 to ensure that all gas has been removed.
[0044] After removing the bubbles, the sample solution is pumped through channel 1628 and into analysis chamber 1642 by applying fluid pressure through port 1626 while opening port 1650 and closing ports 1602 , 1612 , 1634 , and 1638 . Analysis chamber 1642 is similar to previously described analysis chambers, such as chambers 400 , 500 , 600 , 700 , 800 , 900 , 1000 , 1100 , and 1306 . Analysis chamber 1642 includes sensors, such as a pathogen sensor, host sensor, and non-sense sensor as previously described. In certain approaches, the sample solution flows continuously through analysis chamber 1642 . Additionally or alternatively, the sample solution may be agitated while in analysis chamber 1642 to improve hybridization of the markers with the probes on the sensors. In certain approaches, system 1600 includes a fluid delay line 1644 , which provides a holding space for portions of the sample during hybridization and agitation. In certain approaches, the sample solution sits idle while in analysis chamber 1642 as a delay to allow hybridization.
[0045] System 1600 includes a reagent chamber 1630 , which holds electrocatalytic reagents, such as transition metal complexes Ru(NH 3 ) 6 3+ and Fe(CN)6 3−, for amplifying electrochemical signals that arise when markers in the sample solution bind the probe. This amplification is discussed in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/US12/024015, and U.S. Provisional Application No. 61/700,285, which are hereby incorporated by reference herein in their entireties. In certain approaches, the electrocatalytic reagents are stored in dry form with a separate rehydration buffer. For example, the rehydration buffer may be stored in a foil pouch above rehydration chamber 1630 . The pouch may be broken or otherwise opened to rehydrate the reagents.
[0046] In certain approaches, a rehydration buffer is pumped into rehydration chamber 1630 , where it contacts the dried agents. Adding the buffer may introduce bubbles into chamber 1630 . Gas or bubbles may be removed from rehydration chamber 1630 by applying fluid pressure through port 1638 , while opening port 1634 and closing ports 1602 , 1624 , 1626 , and 1650 so that gas is expelled through channel 1630 and port 1634 . Similarly, fluid pressure may be applied through port 1634 while opening port 1638 . After the sample solution has had sufficient time to allow the markers to hybridize to sensor probes in the analysis chamber, the hydrated and degassed reagent solution is pumped through channel 1640 and into analysis chamber 1642 by applying fluid pressure through port 1638 , while opening port 1650 and closing all other ports. The reagent solution pushes the sample solution out of analysis chamber 1642 , through delay line 1644 , and into waste chamber 1646 leaving behind only those molecules or markers which have hybridized at the probes of the sensors in analysis chamber 1642 . In certain approaches, the sample solution may be removed from the cartridge system 1600 through channel 1648 , or otherwise further processed. The reagent solution fills analysis chamber 1642 . In certain approaches, the reagent solution is mixed with the sample solution before the sample solution is moved into analysis chamber 1642 , or during the flow of the sample solution into analysis chamber 1642 . After the reagent solution has been added, an electrocatalytic analysis procedure to detect the presence or absence of markers is performed, for example any of the analysis procedures described or referenced in U.S. Provisional Application No. 61/700,285 or in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/U.S.12/024015,may be applied to the solution to detect the presence or absence of target markers in the sample.
[0047] FIG. 5B depicts an embodiment of a cartridge for an analytical detection system. Cartridge 1700 includes an outer housing 1702 , for retaining a processing and analysis system, such as system 1600 . Cartridge 1700 allows the internal processing and analysis system to integrate with other instrumentation. Cartridge 1700 includes a receptacle 1708 for receiving a sample container 1704 . A sample is received from a patient, for example, with a swab. The swab is then placed into container 1704 . Container 1704 is then positioned within receptacle 1708 . Receptacle 1708 retains the container and allows the sample to be processed in the analysis system. In certain approaches, receptacle 1708 couples container 1704 to port 1602 so that the sample can be directed from container 1704 and processed though system 1600 . Cartridge 1700 may also include additional features, such as ports 1706 , for ease of processing the sample. In certain approaches, ports 1706 correspond to ports of system 1600 , such as ports 1602 , 1612 , 1626 , 1634 , 1638 , and 1650 to open or close to ports or apply pressure for moving the sample through system 1600 .
[0048] Cartridges may use any appropriate formats, materials, and size scales for sample preparation and sample analysis. In certain approaches, cartridges use microfluidic channels and chambers. In certain approaches, the cartridges use macrofluidic channels and chambers. Cartridges may be single layer devices or multilayer devices. Methods of fabrication include, but are not limited to, photolithography, machining, micromachining, molding, and embossing.
[0049] FIG. 6 depicts an automated testing system to provide ease of processing and analyzing a sample. System 1800 may include a cartridge receiver 1802 for receiving a cartridge, such as cartridge 1700 . System 1800 may include other buttons, controls, and indicators. For example, indicator 1804 is a patient ID indicator, which may be typed in manually by a user, or read automatically from cartridge 1700 or cartridge container 1704 . System 1800 may include a “Records” button 1812 to allow a user to access or record relevant patient record information, “Print” button 1814 to print results, “Run Next Assay” button 1818 to start processing an assay, “Selector” button 1818 to select process steps or otherwise control system 1800 , and “Power” button 1822 to turn the system on or off. Other buttons and controls may also be provided to assist in using system 1800 . System 1800 may include process indicators 1810 to provide instructions or to indicate progress of the sample analysis. System 1800 includes a test type indicator 1806 and results indicator 1808 . For example, system 1800 is currently testing for Chlamydia as shown by indicator 1806 , and the test has resulted in a positive result, as shown by indicator 1808 . System 1800 may include other indicators as appropriate, such as time and date indicator 1820 to improve system functionality.
[0050] The foregoing is merely illustrative of the principles of the disclosure, and the systems, devices, and methods can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation. It is to be understood that the systems, devices, and methods disclosed herein, while shown for use in detection systems for bacteria, and specifically, for Chlamydia Trachomatis, may be applied to systems, devices, and methods to be used in other applications including, but not limited to, detection of other bacteria, viruses, fungi, pions, plant matter, animal matter, protein, RNA sequences, DNA sequences, as well as cancer screening and genetic testing, including screening for genetic disorders.
[0051] FIGS. 7-9E illustrate an additional embodiment of a point of care device that integrates on-board dried agents that facilitate sample preparation and lysis as well as catalyzing and enhancing the signal in the analysis chamber. The embodiment shown in those figures includes lysis chamber 1306 , including the two compartments 102 a and 102 b discussed above, but it would be understood that the same point of care device could be configured with a single lysis chamber 1306 with a lysing agent such as a chemical lysing agent having a predetermined concentration sufficient to chemically lyse the cells and partially fragment the cell analytes contained in a patient sample that flows therein. In the depicted embodiment, the dual chamber system of FIG. 4 is used. This system is a variation on the system shown in FIGS. 4-6 , such that analytical data developed or obtained through the use of the system could be programmed and viewed and manipulated and recorded, printed and otherwise controlled by the testing system shown in FIG. 6 .
[0052] FIG. 7 depicts a hand-held point of care device 2000 having a sample inlet chamber 1602 , a lysing chamber 1306 , an analysis chamber with a sensor 1642 that receives fluid from the lysing chamber 1306 after it has been processed through the lysing chamber 1306 and reagent chamber 1630 a and 1630 b. The reagent chambers 1630 a and 1630 b perform a similar function and, in example embodiments, identical function as the reagent chamber 1630 in FIGS. 4-5 , in that they contain catalytic reagents that are dried to the interior surface of the chamber 1630 , and those reagents are hydrolyzed and deployed into the analysis chamber 1642 to amplify the signal from the sensor, as described above in the embodiments of FIGS. 4 and 5 . Applications of electrochemical techniques are described in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/U.S.12/024015, which are hereby incorporated by reference herein in their entireties.
[0053] In particular, in preferred embodiments the reagents included in the reagent chamber 1630 a are a redox pair having a first transition metal complex and a second transition metal complex, which together form an electrocatalytic reporter system (ECAT system) which amplifies the signal from the sensor, indicating a match between the genetic sequence fragments in the lysed sample and the sequences of the PNA probe. Examples of such pairs and amplification are Ru(NH 3 ) 6 3+ and Fe(CN) 6 3− , as further described in U.S. Provisional application No. 61/700285. These reagents are dried down to the interior walls of the chamber 1630 a. A blister 1631 contains a phosphate buffered salient solution (PBS) that is undiluted from a stock sample (thus the 1×). As will be explained below, after the sample buffer enters the tube 1602 , the blister 1631 is punctured and flows into the chamber 1630 b and thereafter mixes with the components of the ECAT system in 1630 a to form a rehydrated reagent solution. The rehydrated reagent solution later flows into the analysis chamber 1642 , where it meets with the lysate contents from the neutralization chamber 102 b after they are bound and annealed to the sensor, as explained previously and further described below.
[0054] FIG. 8 depicts in further detail components of this hand-held system 2000 , also referred to as a device 2000 . As shown, the neutralization chamber 102 b contains neutralization chemicals 103 (e.g., an acid) and the lysis chemical chamber 102 a contains a lysis agent (e.g., a strong base such as NaOH). As explained above in regard to FIGS. 3A-4 , the neutralization agent and lysis agents are preferably dried to the interior surface of their respective chambers 102 b and 102 a.
[0055] FIGS. 9A-9E depict the use and operation of the system 2000 or the hand-held device 2000 . In a first step as shown in FIG. 9A , the sample is inserted into the sample chamber by the inlet port 1602 and flows by tube 1308 into the lysing compartment 102 a. Inside the lysing compartment 102 a, a strong lysing agent is provided, for example a base such as NaOH. The lysing agent is preferably dried to the interior surface of the compartment 102 a. In certain implementations that agent may be dried within a well or separate receptacle located within the compartment 102 a. In a second step, as shown in FIG. 9B , the blister 1631 is ruptured and releases the PBS into the metering chamber 1630 b and is then pumped into the rehydrolysis chamber 1630 a where the electrode catalytic agents (e.g., the ruthenium and ferric agents identified above) are located and preferably dried to the interior surface of the chamber 1630 a. The chamber 1630 a in this embodiment serves as a multi-use flow chamber to which it can both store the electrode catalytic agents and serve as the locale for rehydrating them, and also function as a receptacle for the receipt of the sample after it has lysed in the lysing chamber 1306 , as described below.
[0056] After the blister 1631 has ruptured, the fluid in the blister flows into the metering chamber 1630 b and is pumped through channel 1635 into the rehydration chamber 1630 a whereupon it mixes with the catalytic agents which are dried to the interior surface of the chamber 1630 a. The dried agents are solubilized in the blister fluid and thereafter they are pumped in reverse direction through channel 1635 back into the metering chamber 1630 b, where they are stored for later use. Alternative designs could be used, where the solubilized electrocatalytic agents (e.g., the ECAT Ru and Fe components) are stored in the rehydration chamber 1630 a and then applied directly to the sensor area 1642 .
[0057] FIG. 9C depicts a next step (which could be applied in reverse order with the step of FIG. 9B ). In this step the sample, which was lysed previously in the lysate formed in the chamber 102 a, is pumped into the neutralization chamber 102 b, where it dissolves a spot of dried neutralizing agent (such as an acid). As that dissolving occurs, the buffer flowing with the sample from chamber 102 a is neutralized in its pH, achieving a pH that is less basic than the pH of the buffer while in chamber 102 a. In preferred implementations the neutralizing agent in chamber 102 b produces a solution of neutral pH such that the solution that exits the chamber 102 b via flow outlet 1038 is of neutral pH and is ready for application to the sensor. That sample leaves the neutralization chamber via flow tube 1308 and is identified in FIG. 9C as sample 1400 .
[0058] As shown in FIG. 9D , the sample 1400 which is preferably neutralized in its pH flows into the hydration chamber 1630 a, which in this embodiment has a multi-purpose use for not only storing the catalytic agents for rehydration, but also then stores the neutralized and lysed sample solution 1400 prior to application to the sensor. This neutralized sample flows through the rehydration chamber 1630 a and it slowly moved across the sensor 1642 where it is subject to the hybridization with the probe located in the sensor 1642 area. The neutralized sample flows down to the waste chamber 1646 after contacting the sensor area 1642 . As depicted in FIG. 9E , after loading the sample onto the sensor 1642 , the rehydrated electrocatalytic agents then flow slowly from the chamber 1630 b through the flow channel 1635 and back to the sensor plate in area 1642 . After the catalytic agents are applied to the sensor then analysis occurs as described above and as explained further in the U.S. Provisional Application No. 61/700,285, the contents of which are incorporated by reference. Applications of electrochemical analysis that can be used are also described in further detail in U.S. Pat. Nos. 7,361,470 and 7,741,033, and PCT Application No. PCT/U.S.12/024015, which are hereby incorporated by reference herein in their entireties.
[0059] FIG. 10 illustrates an example performed using the system 2000 , including illustrative dried components and their concentrations used in the point of care system 2000 . For example, the ECAT components are dried down separately in chamber 1630 a with Ru(NH 3 ) 6 3+ (30 μl at 0.017 mM) and Fe(CN) 6 3− (30 μl of 7.1 mM). Spots of those components are rehydrated with 213 μl of PBS, which is stored in blister 1631 . The lysis sources (chemical agents) are dried to the chambers 102 a and 102 b. The lysing agent (NaOH in this example) is provided in a 10 μl dried spot on surface 102 a. A sample buffer of 200 μl (0.2 M phosphate buffer at pH 7.2) containing CT bacterial cells is provided through the sample port 1602 . Dissolution of the NaOH spot raises the buffer pH to pH 11 and lyses the bacteria in approximately 3 minutes. Lysis is stopped by neutralizing the buffer to pH 7.2 in chamber 102 b, using Citric Acid. The Citric Acid (10 μl, of 1M) was dry spotted onto the interior surface of the chamber 102 b.
[0060] Variations and modifications will occur to those of skill in the art after reviewing this disclosure. The disclosed features may be implemented, in any combination and subcombination (including multiple dependent combinations and subcombinations), with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated in other systems. Moreover, certain features may be omitted or not implemented.
[0061] Examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the scope of the information disclosed herein. All references cited herein are incorporated by reference in their entirety and made part of this application. | Disclosed herein are systems, devices, and methods for detecting the presence of a pathogen in a biological host, such as in a point of care setting. In certain aspects, materials and methods improve point of care devices by providing pre-loaded, preferably dried, agents for performing one or more of sample lysis and signal enhancement inside the device. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Taiwan Patent Application No. 103137103, filed on Oct. 28, 2014, the contents of which are incorporated by reference herein.
FIELD
[0002] The present disclosure relates to a supporting apparatus.
BACKGROUND
[0003] When a portable electronic device, for example a tablet computer, is being used, one hand supports the portable electronic device and the other hand operates the functions of the portable electronic device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
[0005] FIG. 1 is an isometric view of a supporting apparatus in a first state according to an exemplary embodiment.
[0006] FIG. 2 is an exploded, isometric view of part of the supporting apparatus of FIG. 1 .
[0007] FIG. 3 is similar to FIG. 2 , but viewed from another angle.
[0008] FIG. 4 is an isometric view of the supporting apparatus of FIG. 1 in a second state.
[0009] FIG. 5 is an isometric view of the supporting apparatus of FIG. 1 supporting an electronic device.
DETAILED DESCRIPTION
[0010] It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.
[0011] Several definitions that apply throughout this disclosure will now be presented.
[0012] The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need not be exact. For example, “substantially cylindrical” means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series, and the like.
[0013] FIG. 1 illustrates a supporting apparatus 100 including a first connection member 10 , a second connection member 40 , a third connection member 50 , a fourth connection member 60 and a fifth connection member 70 .
[0014] FIGS. 2 and 3 illustrate that one end of the first connection member 10 defines a first clamping groove 13 , and the other end of the first connection member 10 defines a fixing groove 15 . In the embodiment, the first connection member 10 is a substantially cylindrical pole. The cylindrical pole includes two first clamp pieces 14 at one end of the cylindrical pole. The two first clamp pieces 14 are substantially parallel. The first clamping groove 13 is positioned between the two first clamp pieces 14 . The fixing groove 15 is defined at a lateral surface of the first connection member 10 .
[0015] The second connection member 40 includes a first pole 41 and a first rotation body 15 . The first pole 41 is a substantially cylindrical. The first pole 41 includes two second clamp pieces 44 at one end of the first pole 41 . The two second clamp pieces 44 are substantially parallel. A second clamping groove 43 is defined between the two second clamp pieces 44 . The first rotation body 45 is attached to the other end of the first pole 41 away from the second clamping groove 43 . The first rotation body 45 is received in the first clamping groove 13 . The first rotation body 45 is rotatable around a center axis of the first pole 41 in the first clamping groove 13 and rotatable around an axis Y perpendicular to an extended direction of the two first clamp pieces 14 . Thus, an angle between the second connection member 40 and the first connection member 10 is adjustable when the second connection member 40 rotates around the axis Y. The second connection member 40 further defines a connection hole 411 between the second clamping groove 43 and the first rotation body 45 . In the embodiment, the connection hole 411 is defined on a lateral surface of the second connection member 40 . The first rotation body is an elastic ball. A diameter of the ball is greater than a distance between the two first clamp pieces 14 . Therefore, the ball can be firmly received in the first clamping groove 13 .
[0016] The third connection member 50 has a structure similar to the second connection member 40 . The third connection member 50 includes a second pole 51 and a second rotation body 55 . The second pole 51 is a substantially cylindrical. The second pole 51 includes two third clamp pieces 55 at one end of the second pole 51 . The two third clamp pieces 55 are substantially parallel. A third clamping groove 53 is defined between the two third clamp pieces 55 . The second rotation body 55 is attached to the other end of the second pole 51 away from the third clamping groove 53 . The second rotation body 55 is received in the second clamping groove 43 . The second rotation body 55 is rotatable around a center axis of the second pole 51 in the second clamping groove 43 and rotatable around an axis L 1 perpendicular to an extended direction of the two second clamp pieces 44 . Thus, an angle between the third connection member 50 and the second connection member 40 is adjustable when the third connection member 50 rotates around the axis L 1 . FIG. 4 illustrates that a distal end of the two third clamp pieces 54 away from the second rotation body 55 can be received in the fixing groove 15 when the second connection member 10 rotates around the axis Y and the third connection member 50 rotates around the axis L 1 . Thus, the first connection member 10 , the second connection member 40 and the third connection member 50 form a triangle. In the embodiment, the first connection member 10 , the second connection member 40 and the third connection member 50 have a same length. Thus, the first connection member 10 , the second connection member 40 and the third connection member 50 form an isosceles triangle.
[0017] The fourth connection member 60 has a structure similar to the second connection member 40 . The fourth connection member 60 includes a third pole 61 and a third rotation body 65 . The third pole 61 is a substantially cylindrical. The third pole 61 includes two substantially parallel fourth clamp pieces 64 at one end of the third pole 61 . A fourth clamping groove 63 is defined between the two fourth clamp pieces 64 . The third rotation body 65 is attached to the other end of the third pole 61 away from the fourth clamping groove 63 . The third rotation body 65 is received in the third clamping groove 53 . The third rotation body 65 is rotatable around a center axis of the third pole 61 in the third clamping groove 53 and rotatable around an axis L 2 perpendicular to an extended direction of the two third clamp pieces 54 . Thus, an angle between the fourth connection member 60 and the third connection member 50 is adjustable when the fourth connection member 60 rotates around the axis L 2 .
[0018] The fifth connection member 70 has a structure similar to the second connection member 40 . The fifth connection member 70 includes a fourth pole 71 and a fourth rotation body 75 . The fourth pole 71 is a substantially cylindrical. The fourth pole 71 includes two substantially parallel fifth clamp pieces 74 at one end of the fourth pole 71 . A fifth clamping groove 73 is defined between the two fifth clamp pieces 74 . The fourth rotation body 75 is attached to the other end of the fourth pole 71 away from the fifth clamping groove 73 . The fourth rotation body 75 is received in the fourth clamping groove 63 . The fourth rotation body 75 is rotatable around a center axis of the fourth pole 71 in the fourth clamping groove 63 and rotatable around an axis L 3 perpendicular to an extended direction of the two fourth clamp pieces 64 . Thus, an angle between the fifth connection member 70 and the fourth connection member 60 is adjustable when the fifth connection member 70 rotates around the axis L 3 . The fifth connection member 70 further includes a fixing member 20 . The fixing member 20 is rotationally received in the fifth clamping groove 73 . An end of the fixing member 20 can be received in the connection hole 411 to support the second connection member 40 . In the embodiment, the fixing member 20 includes a ball 21 and a fixing portion 23 attached to the ball 21 . The ball 21 is rotationally received in the fifth clamping groove 73 . The fixing portion 23 is configured to be received in the connection hole 411 . FIG. 5 illustrates when the first connection member 10 , the second connection member 40 and the third connection member 50 are formed to a triangle and the fixing member 20 is received in the fixing hole 411 , the supporting apparatus 100 can support an electronic device 80 .
[0019] The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the details, including in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. | A supporting apparatus includes a first connection member, a second connection member defining a fixing groove, a third connection member, a fourth connection member and a fifth connection member. The first connection member, the second connection member and the third connection member are rotationally connected to each other head to hail to form a triangle and can be detached from each other. The fourth connection member is detachably attached to and rotatable around the third connection member. The fifth connection member is detachably attached to and rotatable around the fourth connection member. The second connection member defines a connection hole. A portion of the fifth connection member is detachably received in the connection hole to support the triangle. | 5 |
[0001] This relates to a fiber cement board which incorporates a modified cellulose pulp fiber.
BACKGROUND
[0002] The internal structures of houses and other buildings are commonly protected from environmental elements by exterior siding materials. These siding materials are typically planks or panels composed of wood, concrete, brick, aluminum, stucco, wood composites, or fiber-cement composites. Some common fiber-cement composites are fiber-cement siding, roofing, and trim which are generally composed of cement, silica sand, unbleached wood pulp, and various additives. Fiber-cement products offer several advantages over other types of materials, such as wood siding, because they are weatherproof, relatively inexpensive to manufacture, fire-resistant, and invulnerable to rotting or insect damage.
[0003] Most commercial fiber-reinforced cement siding products are made using the Hatsheck process. The Hatsheck process was initially developed for the production of asbestos composites, but it is now used for the manufacture of non-asbestos, cellulose fiber reinforced cement composites. In this process, bales of unbleached cellulose pulp fibers are re-pulped in water to provide substantially singulated fibers. The re-pulped fibers are refined and then mixed with cement, silica sand, clay, and other additives to form a mixture. The fiber-cement mixture is deposited on a felt band substrate, vacuum dewatered, layered and in some cases pressed, and then cured to form a fiber reinforced cement matrix in sheet form. The form may have the appearance of standard beveled wood siding.
[0004] Other commonly used fiber cement manufacturing processes known to those skilled in the art are: the Magnani process, extrusion, injection molding, hand lay-up, molding and the Mazza pipe process.
[0005] Cellulose pulp fibers have two roles in the manufacture of fiber cement products.
[0006] Cellulose pulp fibers act as a filter medium in the cement mixture slurry during the drainage process on the forming wire to help retain cement and silica particles while the excess water is being removed from the cement suspension. If there is no filter medium then a great deal of the solids from the slurry will be lost with the water during the drainage process. The purpose of the filter medium is to retain the cement mixture within the product while removing the water.
[0007] The fibers also reinforce the cement product. The fiber cement board manufacturers want good strength and good flexibility in the cement board. Strength is indicated by the modulus of rupture of the board. Flexibility is shown by the deflection of the board at maximum load. Maximum load is the amount of force that can be applied to the board before it breaks. Deflection at maximum load is how far the board deflects from the horizontal plane of the board before breaking in three point bending.
[0008] A standard against which other cellulose chemical pulp fibers are measured is the Douglas fir unbleached chemical pulp fiber. Other fibers must be comparable with Douglas fir unbleached chemical pulp fiber in modulus of rupture, maximum load and deflection at maximum load if they are to be considered for use in fiber cement board.
[0009] Fiber cement boards made with bleached cellulose pulp fibers usually have high strength but are brittle, resulting in poor flexibility. These boards tend to break if flexed and also tend to break when nailed. It would be advantageous to provide a fiber cement board made with bleached cellulose chemical pulp fibers that exhibits both high strength and good flexibility.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a graph comparing the modulus of rupture, maximum load and deflection at maximum load for fiber cement boards with different cellulose pulp fibers.
[0011] FIGS. 2 and 3 are charts of deflection curves of a bleached fiber and the oil treated bleached fiber.
DESCRIPTION
[0012] The fiber cement boards of the present invention may be manufactured by any of a number of processes. Typical processes are the Hatsheck process, the Magnani process, extrusion, injection molding, hand lay-up, molding and the Mazza pipe process.
[0013] In the manufacture of fiber cement board, bales of cellulose pulp fibers are re-pulped in water to provide substantially singulated fibers. The re-pulped fibers are refined and then mixed with cement, silica sand, and other additives to form a mixture. The mixture is then formed into a fiber cement board. In one process the fiber-cement mixture is deposited on a felt band substrate, vacuum dewatered, and cured to form a fiber reinforced cement matrix in sheet form. The sheets may take the form of standard beveled wood siding. They may also take the form of building sheets, panels, planks and roofing.
[0014] The usual composition of the fiber cement board is 10 to 90% by weight cement, 20 to 80% by weight silica sand, and 2 to 18% by weight cellulose pulp fibers. The other additives that are usually found in the fiber cement board are: density modifiers, weight modifiers, flame retardants, clay, kaolin, metakaolin, silica fume, fly ash, defoamers, viscosity modifiers, light weight aggregates, perlite, vermiculite, mica, pumice, ash, flocculants, alum, alumina trihydrate, waterproofing agents, wollastonite, calcium carbonate, resins, pigments, diatomaceous earth and resins.
[0015] The proportion of the cementitious binder, aggregate, density modifiers, and additives can be varied to obtain optimal properties for different applications, such as roofing, deck, fences, paving, pipes, siding, trim, soffits, backer for tile underlayment. For an air-cured product, a higher percentage of cement can be used, more preferably about 60-90%. In an air-cured embodiment, the fine ground silica is not used, although silica may be used as a filler.
[0016] The cementitious binder is preferably Portland cement but can also be, but is not limited to, high alumina cement, lime, high phosphate cement, and ground granulated blast furnace slag cement, or mixtures thereof. The aggregate is preferably ground silica sand but can also be, but is not limited to, amorphous silica, micro silica, silica fume, diatomaceous earth, coal combustion fly and bottom ashes, rice hull ash, blast furnace slag, granulated slag, steel slag, mineral oxides, mineral hydroxides, clays, magnasite or dolomite, metal oxides and hydroxides and polymeric beads, or mixtures thereof.
[0017] The density modifiers can be organic and/or inorganic lightweight materials. The density modifiers may include plastic hollow materials, glass and ceramic materials, calcium silicate hydrates, microspheres, and volcano ashes including perlite, pumice, shirasu balloons and zeolites in expanded forms. The density modifiers can be natural or synthetic materials. The additives can include, but are not limited to, viscosity modifiers, fire retardants, waterproofing agents, silica fume, geothermal silica, thickeners, pigments, colorants, plasticizers, forming agents, flocculents, drainage aids, wet and dry strength aids, silicone materials, aluminum powder, clay, kaolin, alumina trihydrate, mica, metakaolin, calcium carbonate, wollastonite, and polymeric resin emulsion, or mixtures of thereof.
[0018] Usually unbleached Douglas fir chemical pulp fibers are used in the manufacture of fiber cement board. These have been found in the industry to provide the best combination of modulus of rupture, maximum load and deflection at maximum load.
[0019] If unbleached Douglas fir cellulose pulp fibers are in short supply then it is necessary to find other pulp fibers that can be used. Usually other unbleached cellulose pulp fibers having lengths similar to Douglas fir have been used. Redwood is an example.
[0020] Bleached softwood chemical pulp fibers have been considered because of their length but have not been used because they tend to result in brittle boards. They tend to have strength that is the same or slightly higher than unbleached Douglas fir chemical pulp fiber but usually have flexibility that is far less than unbleached Douglas fir chemical pulp fibers.
[0021] The present invention can utilize a number of pulp fibers. Coniferous and broadleaf species can be used. These are also known as softwoods and hardwoods. Softwoods would normally be used because they have longer fibers than hardwoods. Typical softwood species are spruce, fir, hemlock, tamarack, larch, pine, cypress and redwood. Typical hardwood species are ash, aspen, cottonwood, basswood, birch, beech, chestnut, gum, elm, maple and sycamore. Recycled cellulosic material can be used as starting material for the fibers. The present invention can use chemical, mechanical, thermomechanical and chemithermomechanical pulp. Kraft, sulfite and soda chemical pulps can be used. The fibers can be bleached or unbleached. The present invention can be used with unbleached Douglas fir chemical pulp fibers.
[0022] Usually, softwood or coniferous species will be used because of fiber length. Hardwood or broadleaf species have a fiber length of 1-2 mm. Softwood or coniferous species have a fiber length of 3.5 to 7 mm. Douglas fir, grand fir, western hemlock, western larch, and southern pine have fiber lengths in the 4 to 6 mm range. Pulping and bleaching may reduce the average length slightly because of fiber breakage.
[0023] In the manufacture of pulp woody material is disintegrated into fibers either in a chemical or mechanical type process. The fibers can then be optionally bleached. The fibers are then slurried with water in a stock chest, The slurry then passes to a headbox and is then placed on a wire, dewatered and dried to form a pulp sheet. Additives may be combined with the fibers in the stock chest, the headbox or both. Materials may also be sprayed on the pulp sheet before, during or after dewatering and drying.
[0024] The fibers of the present invention are treated with two materials in either the stock chest or the headbox.
[0025] The first material is an oil. The oil can be either a vegetable oil or a mineral oil. The oil is in globule form. It may be treated with a surfactant in order to form the globules and to provide the anionic character. One such vegetable oil additive is Eka Soft F60. In use Eka Soft F60 is diluted with at least 20 times its volume of warm water at 30 to 40° C. and added to the thick stock in a stock chest. The amount of oil added to the pulp is two to five kg of oil per ton of bleached sulfate pulp and one to three kg of oil per ton of bleached sulfite pulp.
[0026] Other vegetable oils that might be used would be any vegetable oil that is liquid at the drying temperature of pulp, around 100° C. Vegetable oils that might be used could include, among others, apricot oil, argan oil, artichoke oil, babassu oil, ben oil, bladder pod oil, Borneo tallow nut oil, bottle gourd oil, buffalo gourd oil, canola oil, carob pod oil, caster oil, coconut oil, copaiba oil, corn oil, cottonseed oil, crambe oil, cuphea oil, false flax oil, flaxseed oil, grapeseed oil, hempseed oil, honge oil, jatropha oil, jojoba oil, kapok seed oil, mango oil, meadowfoam seed oil, milk bush oil, mustard oil, okra seed oil, olive oil, nut oils, palm oil, palm kernel oil, peanut oil, petroleum nut oil, quinoa oil, radish oil, ramtil oil, rapeseed oil, rice bran oil, sesame oil, soybean oil, and tall oil.
[0027] The other material is a cationic retention aid which attaches the oil globules to the pulp fibers. The retention aid can be a cationic polymer such as a polyamide, polyacrylamide or polyethylenimine. One such retention aid is Eka Soft F50. The retention aid is added after the oil to allow the globules of oil to be mixed with the cellulose fibers before being attached to the fibers. In making hand sheets the retention aid was added about 6 minutes after adding the oil. In the stock chest it could be added at the fan pump. A cationic retention aid will attach to the anionic sites on the cellulose fiber and the anionic sites on the oil globule. The amount of retention aid can be from 0.25 to 3.0 kg of retention aid per tonne of cellulose fiber.
[0028] Other retention aids that can be used can be organic retention aids such as polyacrylamides, polyamines, polyethylenimines, polyamidoamines, polyethylene oxides, polyionenes and polypyrrolidinium derivatives. Another retention aid could be a cationic starch. Inorganic retention aids could be aluminum sulphate or papermakers alum, polyaluminum chloride, sodium aluminate. Another inorganic retention aid could be an alkaline activated bentonite in conjunction with nonionic high molar mass polyacrylamides.
[0029] A fiber cement board which incorporates a bleached pulp fiber treated with globules of anionic oil that have been attached to the fibers by a retention aid, has a modulus of rupture that is comparable to a fiber cement board that incorporates an unbleached Douglas fir chemical pulp fiber or a fiber cement board that incorporates a bleached fiber treated with a quaternary ammonium dispersant, and has a deflection at maximum load that is much higher than a fiber cement board that incorporates unbleached Douglas fir chemical pulp fiber or a fiber cement board that incorporates a bleached fiber treated with a quaternary ammonium dispersant. The deflection of the oil boards with oil treated fibers could be more than double either of the other boards. The impact strength of the boards with oil treated fibers could be almost double that of the boards with bleached fiber or the boards with bleached fiber treated with a quaternary ammonium dispersant and approximately 25% higher than boards with the standard unbleached Douglas fir fiber.
[0030] It has been found that a fiber cement board which incorporates a bleached pulp fiber treated with the globules of anionic vegetable oil that have been attached to the fibers by a retention aid, has a modulus of rupture that is comparable to a fiber cement board that incorporates an unbleached Douglas fir chemical pulp fiber or a fiber cement board that incorporates a bleached fiber treated with a quaternary ammonium dispersant, and, surprisingly, has a deflection at maximum load that is much higher than a fiber cement board that incorporates unbleached Douglas fir chemical pulp fiber or a fiber cement board that incorporates a bleached fiber treated with a quaternary ammonium dispersant. In some instances the deflection is more than double either of the other boards. It was also found that the impact strength of the boards with oil treated fibers was almost double that of the boards with bleached fiber or the boards with bleached fiber treated with a quaternary ammonium dispersant and approximately 25% higher than the boards with standard unbleached Douglas Dir fiber.
[0031] The boards with oil treated fiber can have a flexure extension of greater than 30 mm, and even 40 or more mm, as compared with a flexure extension of less than 30 mm, or even less than 20 mm, for a board with bleached fibers.
[0032] While not wishing to be bound by theory, it is believed that the reason the higher deflection is obtained is that the larger globules coat the entire fiber and allow the fiber to move with respect to the cement board in the fiber cement board. This maximizes the frictional force energy of the fiber within the matrix instead of binding it tightly to the matrix resulting in the tensile strength of the fiber becoming the only component to resist the load. This allows the fiber cement board to have a greater deflection than a fiber which attaches to the cement in the fiber cement board. The cement fiber board incorporating bleached fiber treated with globules of vegetable oil which have been attached with a retention aid can have a deflection that is at least twice the deflection of a fiber cement board incorporating unbleached Douglas fir chemical pulp fiber, This is borne out in the following table. The following table compares the modulus of rupture, maximum load and deflection at maximum load for several fiber cement boards. The only difference in the boards and the method of manufacturing the boards is the fiber incorporated into the fiber cement board. The fibers are a control, a standard fiber cement grade unbleached kraft which is unbleached Douglas fir kraft pulp, and several bleached kraft fibers. The bleached kraft fibers are PW416 which is bleached untreated southern pine kraft pulp from the Port Wentworth, Ga., Weyerhaeuser pulp mill; NF401 which is a bleached southern pine kraft pulp from the Weyerhaeuser New Bern, N.C., pulp mill which was treated with ˜0.15% Ekasoft 509HA debonder; and NF405 which is a bleached southern pine kraft pulp from the Weyerhaeuser New Bern, N.C., pulp mill which was treated with ˜0.25% Ekasoft 509HA debonder, and a bleached southern pine pulp fiber, a Treated fiber of the invention, treated with an anionic vegetable oil Eka Soft F60 and a cationic retention aid Eka Soft F50. The bleached fibers are comparable except for the treatment of the fiber, whether the fibers have been treated and the material used to treat the fiber.
[0033] The following samples were made using a hand sheet mold, they were dewatered using vacuum and pressed. The mix design used follows the accepted industry practice of approximately 30 to 40% cement with 50 to 60% silica and between 4 to 12% cellulose fiber by weight. Small percentages of clay and additives were added to aid in board formation. The samples were cured in an autoclave and were then conditioned for testing. The boards were measured for thickness to make sure all boards were within tolerance for comparative testing. The sample strips were cut for testing and were tested for MOR, Deflection and Max Load using three point bending. Notched IZOD testing was also undertaken to measure the impact strength of the boards.
[0000]
Deflection at
maximum
Impact
MOR
Max. load
load
Strength
Fiber
(MPa)
(kgf)
(mm)
(lb · ft/in 2 )
Unbleached
1
12.83
4.15
9.731
Douglas fir
2
12.99
4.23
8.892
3
11.81
3.78
8.733
4
12.53
4.05
7.203
Avg.
12.54
4.05
8.640
0.98
PW416
1
13.52
4.4
3.966
2
13.12
4.27
4.137
3
14.47
4.72
4.93
4
14.29
4.65
5.834
Avg.
13.85
4.51
4.717
0.64
NF401
1
13.16
4.2
5.679
2
14.47
4.47
6.845
3
12.72
4.
5.74
4
14.11
4.43
6.066
Avg
13.62
4.23
6.083
0.70
NF405
1
15.26
5.05
8.52
2
14.39
4.93
8.61
3
15.17
5.06
9.01
4
15.63
5.24
9.39
Avg.
15.13
5.07
8.83
0.73
Treated fiber
1
13.91
4.21
21.58
2
14.62
4.37
21.16
3
14.44
4.38
21.19
4
13.65
3.65
24.65
Avg.
14.16
4.15
22.15
1.22
[0034] The fiber cement boards which incorporate bleached pulp fibers have a higher modulus of rupture and a higher maximum load than the fiber cement boards that incorporate unbleached Douglas fir chemical pulp fibers but only one, the fiber cement board incorporating NF405, has a deflection that is comparable to the boards incorporating Douglas fir fibers. The other boards incorporating bleached fibers have a deflection that is one-half to three-quarters that of the boards incorporating Douglas fir fibers.
[0035] The board with oil treated fiber had an MOR and maximum load that was equivalent to the board with Douglas fir fiber but had a deflection that was two and a half times that of the board with Douglas fir fiber. This can be explained if we consider that bleached fibers are bound far more tightly by the cement matrix than the unbleached. The impact strength of the board with oil treated fibers has improved over the standard fiber by almost 25%. The boards with oil treated fibes exhibits higher impact strength than all of the boards with bleached fibers as well as the boards with standard Douglas Fir fiber.
[0036] FIG. 1 is a graphic representation of the information in the table. The board using standard unbleached kraft fiber shows a good combination of MOR and deflection at max load. Boards with PW416, an untreated bleached southern pine kraft pulp fiber, have an increase in strength but a decrease in deflection at max load. Boards with NF401 or NF405, de-bonded southern pine kraft pulp fibers, have an increase in the flexibility of the board while maintaining the overall strength. Boards with the oil treated fiber are significantly different from the boards with the NF401 fiber or the NF405 fiber in that the strength of the board with the oil treated fiber is on par with that of boards with the standard unbleached kraft pulp fiber but the deflection at maximum load is almost two and a half times that of the board with either the standard fiber or the NF405.
[0037] FIGS. 2 and 3 are graphs of flexure load vs. flexure extension. The boards were formed as described above. FIG. 2 is a board using an untreated bleached southern pine fiber. FIG. 3 is a board using an oil treated fiber. There were four samples for each board. The graphs show the effect of the treatment which has altered the bond between the fiber and the cement matrix in such a way as to allow the treated fiber to pulled out of the matrix rather than being broken as in the case of the bleached fiber. The flexure at maximum load and maximum flexure for the board with oil treated fiber is greater than for the other boards. | A building material product comprising a cementitious binder, an aggregate and cellulose reinforcing fibers wherein the cellulose reinforcing fibers have been treated with oil which is bound to the fiber by a retention aid. The resulting fiber when included in a fiber cement composite results in improved deflection of the composite at peak loading as well as improved impact strength while maintaining overall board strength. | 8 |
FIELD OF THE INVENTION
The present invention relates to a peripheral device for a computer and in particular a computer navigation device.
BACKGROUND OF THE INVENTION
Software tools for preventing the automatic shutdown of a computer (or removal of a user's access to a computer network) in the absence of user activity therewith are well known. However, these software tools are subject to software failure and are designed to operate upon specific software platforms (e.g. MSWindows and Linux). Consequently, existing software tools for preventing the automatic shutdown of a computer system are typically inflexible and incapable of operation upon multiple software platforms.
A mouse is a well-known computer peripheral device. More specifically, a mouse is an input device to a host computer wherein the mouse is physically movable by a user to provide access to desired software features on the host computer. In use, movement of the mouse is detected by an on-board sensor (e.g. an infrared sensor) and the resulting sensor signal is transmitted to the host computer through a USB or PS2 port. Alternatively, the sensor signal may be transmitted to the host computer using a wireless technology such as Bluetooth. The format of the data transmitted by the mouse is typically standardized in accordance with protocols for a “Human Interface Device”. On receipt of a signal indicating movement of the mouse, the host computer's operating system moves a cursor on the host-computer's screen.
In addition with the above navigational functionality, a mouse is also typically provided with buttons which when pressed by the user typically activate a required program or software feature. While mice are manufactured with increasingly sophisticated on-board technologies (e.g. optical mice are provided with image processing features to facilitate image analysis), the output data from a mouse is nonetheless exclusively determined by a user's immediate input to the mouse (i.e. movement of the mouse or depression of a button).
While some operating systems (e.g. Windows 3.1) have facilities to record and replay keyboard and mouse movement sequences these facilities are typically dependent upon the specific operating system of the host-computer. Furthermore, the record and replay facility may be disabled to prevent virus activity and in many cases may not be easily reactivated by the user.
Some operating systems incorporate software to schedule programs at certain times, but these task scheduling software systems typically suffer from a number of limitations. For example, the CPU overhead of implementing task scheduling software typically slows the operation of a host computer. Furthermore, the task scheduling software may not be implemented or may be disabled on a host-computer. Finally, existing task scheduling software systems may not operate with programs requiring human interaction (e.g. games etc.). Consequently, existing task scheduling software systems may be unreliable insofar as they fail to carry out a required operation.
SUMMARY OF THE INVENTION
According to the invention there is provided a computer navigation device comprising a movement sensor or sensing means and a trigger or triggering means activated by a timer or timing means to periodically transmit to a host computer a pre-defined signal corresponding with the signal that would otherwise be generated by the movement sensing means on detection of specific movements of the computer navigation device.
According to a second aspect of the invention there is provided a computer navigation device comprising a movement sensor or sensing means, an at least one first user-selectable element, a storage device or means and a transmitter or transmission means, wherein movement of the computer navigation device detected by the movement sensing means and selection of the at least one first user-selectable element is storable in the storage means and retrievable from the storage means at a later date for transmission by the transmission means to a host computer.
Preferably, the computer navigation device is further provided with a trigger or triggering means connectable to the storage means to trigger the retrieval of previously stored movements of the computer navigation device and selections of the at least one first user-selectable element from the storage means. Preferably, the triggering means is activatable by a user. Optionally, the trigger or triggering means may be activatable by a timer or timing means at a predefined time. The computer navigation device may be provided with at least one second user-selectable element wherein the selection of the at least one second user-selectable element activates storage of detected movements of the computer navigation device and selections of the at least one first user-selectable element.
According to a third aspect of the invention there is provided a method of automating mouse-facilitated tasks comprising storing at least one of mouse movements and mouse button depressions in a storage device or means; triggering the retrieval of the stored mouse movements and/or mouse button depressions from the storage means; and transmitting a signal to a host computer, the signal corresponding with the retrieved mouse movements and/or mouse button depressions.
Preferably, the step of triggering the retrieval of the stored mouse movements and mouse button depressions from the storage means is activated by a user. Desirably, the step of triggering the retrieval of the stored mouse movements and mouse button depressions from the storage means is activated by at least one predefined time by a timer or timing means.
The first embodiment of the present invention provides a mechanism for providing a periodic signal to a host computer in the absence of a user input thereto to prevent the shutdown of software operating on the host computer. Consequently, the first embodiment of the present invention prevents or substantially reduces the performance of automatic shutdown tasks typically performed by a host computer in the absence of user interaction therewith.
In contrast with traditional task scheduling software systems the fourth embodiment of the present invention is a small self-contained unit where the correct operation of a simple task (comprising the issuance of a sequence of commands at a specified time) is more easily verified.
BRIEF DESCRIPTION OF THE DRAWINGS
Three embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram illustrating the operation of the first embodiment of the computer navigation device.
FIG. 2 is a schematic diagram illustrating the operation of the third embodiment of the computer navigation device.
FIG. 3 is a schematic diagram illustrating the operation of the fourth embodiment of the computer navigation device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
For the sake of clarity, the computer navigation device of the present invention will be referred to in the following description as an enhanced mouse. Referring initially to FIG. 1 , in a first embodiment of the present invention, the enhanced mouse 2 is provided with at least one button 4 . The depression of the button 4 (or the repeated depression of the button 4 in a pre-defined sequence) causes the enhanced mouse 2 to emit a periodic signal 6 to a host computer 8 .
The periodic signal 6 mimics the signal emitted from a conventional mouse when moved by a user. Accordingly, the transmitted signal 6 causes the host computer 8 to move a cursor 10 on the host computer screen 12 in a pre-determined fashion (e.g. five units right followed by five units left). The movement of the on-screen cursor 10 provides an indication to the host computer's operating system 14 that the host computer 12 is in use and should not be shutdown, disconnected or logged out from a network (not shown).
While the movement of an on-screen cursor will usually be sufficient to prevent an operating system from shutting down, it may not prevent an application from automatically logging off a computer network. Instead, the activation of an on-screen menu may be required in addition to (or instead of) the movement of an on-screen cursor to prevent the application from automatically logging off a computer network.
As will be recalled from the earlier discussion of conventional mouse devices, an on-screen menu element is typically activated by the depression of a button on a conventional mouse. Accordingly, the enhanced mouse in the second embodiment of the present invention prevents an application from automatically logging off a network by emitting a signal that mimics the signal emitted by a traditional mouse in response to the depression of a button.
To prevent the host computer from performing an unintended task, the periodic signal emitted from the enhanced mouse may also be adapted to cause the host computer to activate a specific menu without performing a further action. Furthermore, the periodic signal emitted by the enhanced mouse may also mimic the signal emitted by a traditional mouse when moved by a user (i.e. as described in relation to the first embodiment of the present invention).
The first embodiment of the enhanced mouse transmitted periodic signals to a host computer that mimicked the signal transmitted by a traditional mouse in response to movements thereof by a user. The second embodiment of the enhanced mouse also transmitted signals that mimicked the signals transmitted by a traditional mouse in response to the depression of a specific button thereon.
Many repetitive user tasks comprise interactions with a host computer that may be described by a sequence of mouse movements and mouse button depressions. Accordingly, it is possible to use the approach employed in the first and second embodiments of the present invention to provide a mechanism for automating many such repetitive user tasks. Take for example the task of starting an application. When using a traditional mouse, the task could typically involve the following steps:
(a) moving an on-screen cursor to the bottom right of the host-computer's screen; (b) activating an on-screen menu; (c) moving the on-screen cursor upwards by a pre-defined number of pixels (Mov A ); (d) activating an on-screen menu element (Click A ); (e) moving the on-screen cursor to the right by a pre-defined number of pixels (Mov B ); (f) activating an on-screen menu element (Click B ); (g) moving the on-screen cursor to the right by a pre-defined number of pixels and downwards by a predefined number of pixels (Mov C ); and (h) activating an on-screen element (Click C ).
Referring to FIG. 2 , the third embodiment of the enhanced mouse 102 comprises an on-board (preferably non-volatile) memory 16 , a sensor 18 (as in a conventional mouse) and at least one button 20 specifically dedicated to the storage and/or performance of repetitive user tasks. In use of the enhanced mouse 102 , a desired sequence of mouse operations (e.g. mouse movements Mov A , Mov B and/or mouse button depressions Click A , Click B ) are stored in the on-board memory 16 by moving the enhanced mouse 102 over a desired path and clicking as required.
Once the required sequence of mouse operations has been stored in the enhanced mouse's on-board memory 16 as a macro the macro can be activated by the user by pressing the specifically dedicated button 20 or pressing button(s) 20 in a pre-defined sequence. This will cause the enhanced mouse 102 to retrieve the mouse operations stored in the on-board memory 16 and transmit signals to the host computer corresponding with the retrieved mouse operations.
To establish a fixed absolute starting position for the on-screen cursor, the user must move the enhanced mouse 102 so that the on-screen cursor is moved to one corner of the screen (beyond which the cursor cannot be further moved).
The third embodiment of the present invention provides an enhanced mouse capable of causing a host computer to start an application with minimal human intervention (a single mouse press). This facility is an extension of a timed activation facility. With a timed activation facility, a user can cause an enhanced mouse to store a macro (comprising a sequence of mouse movements and mouse button depressions) using the procedure previously described for the third embodiment. However, instead of the macro being activated in response to a specific user demand as employed in the third embodiment, the enhanced mouse could be programmed to automatically activate the macro at a specific time.
Accordingly, referring to FIG. 3 the fourth embodiment of the present invention comprises an enhanced mouse 202 with an on-board (preferably non-volatile) memory 116 , a sensor 118 , at least one button 120 specifically dedicated to the storage of repetitive user tasks. The fourth embodiment of the present invention further comprises a real time clock 22 to determine the time and trigger events (via an alarm mechanism) for activating a stored macro.
Finally, the fourth embodiment of the present invention includes a mechanism 24 for setting the real time clock and alarm events. The real time clock could be set by a number of mechanisms including:
(a) dedicated switches; (b) “graffiti”/gesture recognition, wherein a user presses a button to enter the system software into a set mode and then draws the time with the mouse, the mouse then uses in-built μP/software to recognize the drawn numbers; (c) analog clock drawing, wherein a user draws the time as on an analog clock; (d) a mouse-pad for an optical mouse that has areas with
(i) patterns/textures corresponding to different numerals (for example black=0, white=9 (intensity modulated); (ii) fine pitch (dots spaced at 100 mm)=0 and coarse pitch (dots spaced at 1100 mm)=9; (iii) combination of intensity, contrast and pitch, e.g. 4 different shades of grey combined with 4 different dot-spacing gives 16 different possibilities.
There are similarly a number of options for enabling the enhanced mouse to confirm the time or provide some other user feedback, including:
(a) a low-cost audio signaling device; (b) a flashing LED; (c) a numeric LED (so the enhanced mouse could also be used as a clock) (d) outputting the time as a sequence of cursor movements and button presses (for example by actually drawing the numbers on the screen wherein the user would preferably start a simple drawing program, e.g. paint, XFig etc. and the text would be drawn on the screen by the mouse).
The timed activation technique could be extended to store several macros and issue them at different times or time intervals. For example, a user could program a sequence to start an application (for example start an audio recording program) at 19:00 and another sequence (end recording) at 19:15. The host computer would then carry out this action, unattended, at the specified times.
Modifications and alterations may be made to the above without departing from the scope of the invention. | A computer navigation device includes a movement sensor and a trigger device activated by a timer. The computer navigation device periodically transmits to a host computer a pre-defined signal corresponding with the signal that would otherwise be generated by the movement sensor on detection of specific movements of the computer navigation device. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention pertains to the machining of rotating workpieces by the use of broaching tools sequentially brought into engagement with the workpiece for removing metal therefrom.
[0003] 2. Description of the Related Art
[0004] It is known to mount a plurality of workpieces on a moving chain and move the workpieces past a fixed tool such as shown in U.S. Pat. Nos. 2,088,119 and 2,191,193. Further, it is known to mount a tool upon a moving chain, such as in a power chain saw, and attention is directed to U.S. Pat. Nos. 1,244,789 and 2,523,301.
[0005] However, the advantages of mounting a plurality of tools in such a manner as to permit the tools to be sequentially moved past a rotating workpiece in order to permit rapid metal removal from the workpiece and yet accurately control such removal and sizing of the workpiece has not been previously appreciated. It is this concept of the linear movement of broach type workpieces past a rotating workpiece with which the invention deals.
OBJECTS OF THE INVENTION
[0006] An object of the invention is to provide a broach machine tool system for use with a rotating workpiece wherein a high rate of production can be achieved at a high level of accuracy.
[0007] Another object of the invention is to provide a broach type machine tool for removing metal from a rotating workpiece wherein the tool moves in a linear path while engaging the workpiece.
[0008] A further object of the invention is to provide a broach type machine tool capable of removing metal from a rotating workpiece wherein a plurality of broach type tools are mounted upon a chain in a spaced manner wherein workpieces may be loaded and unloaded from supporting spindles intermediate machining operations.
SUMMARY OF THE INVENTION
[0009] In the practice of the invention, the linear broach machine includes a frame having spaced opposed rotating spindles defining a workpiece axis of rotation. One or both of the spindles can be powered by a controlled drive unit, and each of the spindles includes clamping mechanism whereby the workpiece may be accurately supported at each end. The machine of the invention was created particularly for heavy duty turning, such as turning the main bearings for internal combustion engine crankshafts. However, it will be appreciated that the invention may be utilized in any turning operation and is particularly suitable in those situations where it is desired to remove a considerable amount of metal in a relatively short time under high conditions of accuracy and tool life.
[0010] In the preferred embodiment of the invention, a combination of sprockets are located in a triangular relationship whereby the tool carriers may be mounted upon spaced parallel chains guided by the sprockets wherein the carriers will move through a triangular path. It is possible to only use two combinations of chain sprockets in the broad concept of the invention, but the use of three combinations of sprockets permits a greater length of chain to be used permitting a greater number of tool carriers to be mounted upon the chain, thereby providing increased flexibility of tool carrier spacing and the rate of chain movement.
[0011] Two of the chain sprocket combinations are spaced in such a relationship as to cause the tool carriers mounted upon the chains to move in a path of movement transverse, normally perpendicular, to the axis of workpiece rotation. In this manner, broaching tools mounted upon the tool carriers will move past the workpiece in a tangential manner. Preferably, the two chain sprocket combinations positioning the tool carriers during a cutting action are vertically spaced wherein the tool carriers and tools are moving in a downward direction during cutting.
[0012] Usually, two or more broaching turning tools are mounted upon a tool carrier, each subsequent tool being located closer to the axis of workpiece rotation wherein the last cutting tool will produce the finished diameter. With some turning operations, the broaching and turning tools necessary to make an entire cut may be located on adjacent tool carriers if it is necessary that three or four tools are required for a machining operation.
[0013] The tool carriers may be spaced along the chain as desired, and usually, sufficient spacing will exist between the carriers necessary to perform a workpiece operation, and the rate of tool carrier movement is such, that after turning, the workpiece spindles may be stopped, the finished workpiece removed from its supporting spindles, and a new workpiece mounted upon the spindles such that the next series of tools will engage the new workpiece and the turning cycle repeated with a new set of tools without stopping the tool carriage movement. The chain mounting of the tool carriers and tools permits a high rate of production with minimal wear upon any given tool, and turning machines constructed in accord with the invention are capable of high production turning operations for extended periods of time between tool replacement.
[0014] To ensure accuracy, the tool carriers are held upon a rigid bedway mounted on the machine frame during cutting. The tool carriers include guide surfaces firmly held against bedway guide surfaces (bearings) and as the bedway is well lubricated, it is possible to support the tool carriers on the bedway during cutting in a relatively movable relationship and yet hold the necessary tolerances to achieve accurate tool removal without chattering.
[0015] It will be appreciated that the aforedescribed machine meets all of the objects of the invention as set forth above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein:
[0017] [0017]FIG. 1 is a front elevational partially broken away view of a linear broach machine in accord with the invention,
[0018] [0018]FIG. 2 is a top plan view of the machine of FIG. 1,
[0019] [0019]FIG. 3 is an elevational view, partially broken, illustrating the machine of FIG. 1 as taken from the right side thereof,
[0020] [0020]FIG. 4 is a detail plan view, partially in section, illustrating the workpiece spindles and bedway construction as taken along Section 4 - 4 of FIG. 3, and
[0021] [0021]FIG. 5 is an elevational detail sectional view as taken through a tool carrier along Section 5 - 5 of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The machine of the invention includes a frame whose basic component is the frame plate 10 which constitutes the base for the spindle support cabinet 12 and the chain support structure 14 . Spindle housings 16 and 18 are mounted upon the spindle support 12 , and these housings rotatably support spindles 20 and 22 , respectively. The spindle 20 supports the workpiece chuck 24 while the workpiece chuck 26 is mounted upon the spindle 22 . The spindle 20 is rotated by the controlled drive unit 28 , FIG. 2, drivingly connected to spindle 20 by the power transmission component 30 .
[0023] The workpiece 32 is affixed between the chucks 24 and 26 for rotation by the controlled drive unit 28 . The workpiece 32 defines the axis of rotation of the apparatus. In the drawings, the workpiece 32 constitutes a crankshaft for internal combustion engines having main bearings 34 which are concentric to the axis of rotation. It will be understood that the particular configuration of the workpiece 32 constitutes no part of the invention as any workpiece to be shaped by turning may be supported upon the chucks 24 and 26 .
[0024] Behind the spindle support 12 , a pair of spaced parallel vertically extending sprocket supporting plates 36 are affixed to and arise from the frame base 10 . The sprocket plates 36 constitute the support for the three chain sprockets, each sprocket actually constituting a pair of axially aligned sprockets rotatably mounted upon an axle, the upper sprocket is designated at 38 , the lower sprocket 40 is located directly below sprocket 38 , and the rear sprocket 42 is located behind the sprocket 40 , and these relationships will be appreciated from FIG. 3. Each of the sprocket sets includes the usual chain links which intermesh with the teeth of the sprockets as the chain passes thereover. An controlled drive unit 44 through a transmission 46 and transmission drive shaft 48 , FIGS. 2 and 3, rotates the rear sprocket set 42 .
[0025] A pair of heavy duty link chains 50 extend over the sprockets 38 , 40 and 42 , and the chains 50 include a downwardly moving portion 52 , an upwardly moving portion 54 , and a rearward moving portion 56 between the sprockets 40 and 42 .
[0026] A plurality of tool carriers 58 are attached to and between the chains 50 by a pin or rod stud structure 59 , FIG. 4. In this manner, a plurality of tool carriers 58 are affixed to the chains 50 in any spacing arrangement desired. Usually, the separation between adjacent tool carriers is substantially the same, but under certain conditions, it may be desired to stagger the tool carrier spacing for reasons later apparent.
[0027] Movement of the tool carriers 58 during the cutting action is controlled by a pair of spaced bedway guides 60 , FIG. 4, rigidly affixed to the machine frame. The bedway guides each define oppositely positioned flat guide surfaces 62 whose planes are parallel to the axis of rotation. Also, the bedway guides 60 include inner end surfaces 64 .
[0028] Each of the tool carriers 58 includes bearing structure which slidably engages the guide surfaces of the bedway guides 60 . The tool carrier bearings 66 engage one of the guide surfaces 62 , while the tool carriage includes a guide surface 67 engaging the bedway guide surfaces 62 closest to the workpiece axis of rotation. End bearings 68 carried by the tool carriers 58 engage the flat bedway guide end surfaces 64 . Spring 70 , FIG. 4, bear against the bearings of the tool carriages, and upon the locking structure for the tool carriages' bearings, not shown, being loosened, the springs 70 will bias the bearings against the bedway guide surfaces. In this manner, the tolerances between the bedway guide 60 and the bearings of the tool carriers can be controlled to prevent tool chattering, and the bearings 66 and 68 will be firmly held against the bedway guide surfaces 60 once they are firmly locked to the tool carrier by their threaded set screw arrangements, not shown.
[0029] As will be appreciated from FIG. 5, each of the tool carriers 58 supports a tool rest plate 72 and is affixed thereto by threaded fasteners, and the tool holder plate 74 is attached to the rest plate 72 by threaded fasteners or tool locking mechanism 76 . The tool holders 78 are mounted upon the tool holder plate 74 by bolts or any locking mechanism, and as will be appreciated from FIG. 5, sequential broach type tools 80 , 82 and 84 are mounted upon the tool holders 78 , three of which are shown in the version of FIG. 5.
[0030] In operation, the workpiece 32 is mounted in the chucks 24 and 26 , and upon energizing of the controlled drive unit 28 , the workpiece 32 will be rotated at the desired rate of speed in a counterclockwise direction as viewed in FIG. 5. The motor 44 is energized which will drive the chains 50 in a counterclockwise direction of movement as viewed in FIG. 3. Accordingly, as the tool carriers 58 move along the bedway guides 60 , the tools 80 , 82 and 84 will come into sequential engagement with the workpiece 32 to remove metal from the main bearings 34 of the workpiece. As will be appreciated from FIG. 5, the tool 82 extends further toward the workpiece axis of rotation than the tool 80 , and thereby will remove metal from the workpiece in a second cut. As the tool 84 moves into engagement with the workpiece main bearing 34 , the fact that the finishing tool 84 is slightly closer to the axis of rotation than tool 82 , the tool 84 only needs to remove a small amount of metal from the workpiece to define the desired finished diameter of the workpiece bearing 34 . In most cases, the entire turning of the workpiece main bearings 34 can be accomplished by the three tools 80 , 82 and 84 .
[0031] From the above description, it will be appreciated that the tools moving along the bedway guides 60 on their associated tool carrier function as a broach wherein each tooth removes the appropriate amount of metal during its cutting action, which is a turning process.
[0032] It is to be understood that the chains and tool carriers 58 are being moved downwardly by the controlled drive unit 44 and transmission 46 at a rather slow rate as to not overload the tool 80 , and the movement of the chains 50 is such that after the finishing tool 84 has properly sized the workpiece main bearing 34 , the spindle controlled drive unit 28 may be stopped and the workpiece 32 removed from the chucks 24 and 26 and a new workpiece inserted in the clamping area. During this time of removal and reloading of workpieces, the chains 50 can continue to move the subsequent tool carrier downwardly toward the newly positioned workpiece and the tools mounted upon the subsequent tool carrier will turn the main bearings of the newly installed workpiece, and the cycle repeated.
[0033] As will be appreciated from FIG. 4, a plurality of tools may be mounted upon a tool carrier wherein all of the main bearings of the workpiece may be simultaneously machined. In FIG. 4, five main bearings are being machined which, of course, requires five sets of tools 80 , 82 and 84 to be mounted upon a common tool carrier 58 .
[0034] The linear broaching machine producing turning operations in accord with the aforedescribed structure is capable of the rapid machining of relatively large, yet complex, workpieces. As a different set of tools engages consecutive workpieces, the tools have adequate time to cool as the tools travel about the triangular configuration of the chains 50 as apparent from FIG. 3. While the disclosed apparatus may require a relatively large number of tools, the high production rate of the machine, and the long tool life achieved, renders this type of machine economically feasible.
[0035] It is also to be appreciated that the inventive concepts could be employed by using only a single tool carrier having tools mounted thereon. In such instance, the controls for the chain controlled drive unit 44 would accelerate chain movement between the unloading and loading of workpieces so as to maintain the desired high production rate. However, preferably, a number of sets of tools and tool carriers are mounted upon the chains so that high production can be achieved while yet attaining a long tool life.
[0036] It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention. | A linear broaching machine for machining rotating parts wherein a plurality of tooling carriages are mounted upon a moving chain and broach type tools are supported by the carriages wherein the tools are moved in a linear path into engagement with a rotating workpiece to remove metal from the workpiece and form an accurately sized cylindrical surface concentric to the workpiece axis of rotation. The tool carriages are spaced from each other providing non-machining access durations wherein the workpiece may be loaded or unloaded from its rotating support spindles. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a method for measuring the level of an item in a liquid and more particularly for measuring the chlorine level in swimming pool water.
By way of background, there are different systems in existence for adding indicating solutions to liquids and thereafter measuring the level of an item in the liquid. However, insofar as known, prior systems were relatively complex or could not provide an accurate output based solely on adding a measured amount of indicating solution to a single sample.
SUMMARY OF THE INVENTION
It is accordingly one object of the present invention to provide an improved electromechanical apparatus for measuring the amount of an item in a liquid by automatically adding an indicator solution to the liquid and comparing the light transmissibility of such solution with liquid which does not contain the indicator solution.
Another object of the present invention is to provide an improved method for measuring the level of an item in a liquid, and more particularly, for measuring the level of chlorine in pool water. Other objects and attendant advantages of the present invention will readily be perceived hereafter.
The present invention relates to apparatus for measuring the level of an item in a liquid comprising first means for placing said liquid into a first light-transmitting vessel, second means for placing said liquid plus an indicator solution into a second light-transmitting vessel, third means for passing a light of a predetermined color through said first and second vessels, and detector means for detecting the differences in light transmission of said liquids in said first and second vessels and for producing an output based thereon which is indicative of the level of said item in said liquid.
The present invention also relates to a method of testing the level of an item in a liquid comprising the steps of providing a first sample of the liquid containing the item, providing a second sample of the liquid with a measured amount of indicator solution therein, comparing the light transmissibility of said first and second samples, and providing an output which is a measurement of the level of said item in said liquid.
The various aspects of the present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary schematic view of an improved automatic chlorine level tester and regulator incorporated into the water pumping system of a swimming pool;
FIG. 2 is a fragmentary side elevational view primarily of the mechanical portion of the improved chlorine level tester and regulator;
FIG. 3 is a schematic electrical diagram of the improved chlorine level tester and regulator;
FIG. 4 is an enlarged fragmentary view of a portion of FIG. 2; and
FIG. 5 is a fragmentary enlarged detail view of a portion of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the following description is directed primarily to the use of the present invention for testing and regulating the chlorine level in swimming pool water, it will be appreciated that it can be used or modified to test other characteristics of water, including but not limited to the bromine level, pH and iron level.
Relative to the chlorine aspect of the present invention, summarizing briefly in advance, the chlorine level tester and regulator 10 is for installation in the water circulation circuit of a swimming pool. Tester and regulator 10 (FIG. 1) includes a combined mechanical and hydraulic component 11 (FIG. 2) and an electrical control component 12 (FIG. 3) with portions of the latter also being shown in FIG. 2. The tester and regulator 10 is designed to operate automatically during the filtration cycle of a swimming pool, or it can be actuated manually. The filtration cycle of the pool is initiated by a timer 13, which is connected to a suitable source of electrical current. Timer 13 periodically activates a pool pump 14 which receives pool water from conduit 15 and pumps it to pool filter 17 through conduit 19 and the water then passes back to the pool through conduit 20, as is well known.
The tester and regulator 10 of the present invention is automatically actuated in response to the energization of filtration cycle timer 13. The electrical power for the chlorine level tester and regulator 10 (hereafter referred to as tester) is obtained through electrical leads 21 and 22 coming from the timer 13, and, more specifically, leads 21 and 22 energize a suitable rectification system 23 (FIG. 3) which produces a regulated DC output. As soon as the power supply 23 is energized, a suitable timer 24, which is coupled thereto, is also energized. In the specific embodiment shown, the timer energizes motor 25, which is connected thereto by leads 27 and 29, after the timer 24 has been energized for fifteen minutes. This fifteen minute waiting period insures that the tester 10 will not be activated until the pool water passing through conduit 20 provides a fair representation of the chlorine level of the pool water.
Motor 25 is mounted on a board 30 with other components of the system. When motor 25 is energized, it will move bellcrank lever 31 in a clockwise direction so that arm 32 will move away from stop 33 and move to stop 34 and remain there for two seconds. In response to the movement of lever 31, lever 35, which is pivoted to board 30 at 37, will move to its dotted line position 35 because of its connection to lever arm 38 through link 39. When lever 35 moves to its dotted line position, pistons 40 and 41, which are pivotally connected to it at pivots 42 and 43, respectively, will move downwardly. A precise amount of pool water will be drawn into semi-transparent cylinder 43 through conduit 44 and check valve 45 by piston 41. Pool water will also be drawn into semi-transparent cylinder 47 by piston 40 from conduit 20 via conduit 49, check valve 50 and conduit 51. Also during the initial movement of lever 35 to its dotted line position, piston 52, which is pivotally connected to lever 35 at 53, will be moved downwardly to expel a precise amount of chlorine indicating solution from cylinder 54 into conduit 55 which is in communication with cylinder 43 via check valve 57. Thus, during the two-second dwell of lever arm 32 at stop 34, a precise amount of pool water is sucked into both cylinders 43 and 47, and, additionally, a precise amount of chlorine indicating solution is expelled from cylinder 54 and injected into cylinder 43. During the foregoing action of pistons 40, 41 and 52, the conduits leading to cylinders 43 and 47 are full of liquid to insure that precise amounts of all of the liquids are supplied to cylinders 43 and 47.
After the foregoing two-second dwell, the timer 24 and associated contacts therein cause reversal of motor 25 to cause bellcrank lever 31 to return to its position of FIG. 2, whereby lever 35 returns to its solid line position. Thus, pistons 40 and 41 will return to their positions of FIG. 2. Pool water will thus be expelled from cylinder 47 and then be dumped to a suitable location via conduits 51 and 59, check valve 60 and conduit 61. Also, the liquid will be expelled from cylinder 43 via check valve 62 and conduit 63 and dumped to a suitable location. At this time piston 52 will also be raised to its solid line position in cylinder 54, and thus a precisely measured charge of chlorine indicating solution will be drawn into cylinder 54 from tank 64 via conduit 65. The foregoing discharging of liquid from cylinders 43 and 47 is for the purpose of flushing to assure that they are cleaned out so that any liquid which they subsequently draw to be tested is a fair representation of the pool water at that time.
Check valves 45, 57 and 62 should be as close as possible to the cylinder 43 so that there will be practically no liquid left in cylinder 43 when piston 41 is in its uppermost position, thereby assuring the accuracy of the measurements because each new charge of liquid is not mixed with a significant amount of residual liquid from a previous filling.
Lever 35 will be maintained in its solid line position for two seconds, and thereafter timer 24 will cause a cycle to be repeated wherein motor 25 causes lever 35 to move to its dotted line position for two seconds to draw in clear pool water into cylinder 47 through the above described path and to draw in a mixture of a precise measured amount of chlorinated pool water and a precise measured amount of chlorine indicating solution into cylinder 43 through the above-described path. While a precise measured amount of chlorinated pool water is also drawn into cylinder 47, this precision is not critical to the subsequent measurement of the chlorine level. Motor 25 is then turned off by timer 24.
From FIG. 5 it can be seen that the ends of conduits 44 and 49 in conduit 20 essentially comprise Venturis so that water from conduit 20 will not be forced into these conduits as a result of the action of the pool pump 14. Water will only enter conduits 44 and 49 as a result of the operation of the pistons 40 and 41 when the tester 10 is actuated in the above-described manner. Alternately, normally closed solenoid valves may be installed in conduits 44 and 49, and these will be opened only in response to the energization of tester 10.
The timer 24 then activates the electrical measuring circuit of FIG. 3. In this respect, current is supplied to blue lamp 67, which may be a blue light emitting diode manufactured by Industrial Devices, Inc., which provides a blue light which shines through semi-transparent cylinder 43 onto photocells 69 and 70 and through semi-transparent cylinder 47 onto photocells 71 and 72. The photocells 69, 70, 71 and 72 are in a Wheatstone bridge type of circuit with amplifier 73. The photocells are of the cadmium sulfide type to respond to the wave length of the light transmitted through the solution. Variable resistors 74 and 75 are used to balance the legs of the circuit in which they are located. This balancing is effected with unchlorinated water in cylinders 43 and 47 prior to operating the system. Variable resistor 77 is used to calibrate the LCD 79 which is responsive to a one-shot input therein. A meter can be used instead of an LCD, if desired. Variable resistor 80 is utilized to vary the input signal strength to time delay unit 81, to increase or decrease the duration of time delay provided by the time delay unit 81. As noted hereafter, the time delay determines the amount of chlorine which is added to the pool water.
As noted above, cylinder 47 contains chlorinated pool water and cylinder 43 contains a mixture of a precise amount of chlorinated pool water plus a precise amount of chlorine indicating agent which in this instance is ortholidine and hydrochloric acid. The chlorinated pool water, without the indicator solution therein, varies in light transmissibility because of the amount of foreign matter therein, which is usually solid material which the filter 17 does not remove. The voltage drop across photocells 71 and 72 will therefore vary with the light they receive from lamp 67, which in turn depends on the amount of unfiltered foreign matter in the pool water. The greater the amount of foreign matter, the higher will be the resistance provided by photocells 71 and 72. However, since the same pool water is in both cylinders 43 and 47, the clarity of the pool water will not affect the voltage output to amplifier 73. In other words, the voltage drop across each of photocells 69, 70, 71 and 72 due to the foreign matter in the pool water will be the same so that the differences in clarity of pool water will not affect the output to amplifier 73.
As can be seen from FIG. 2, photocells 69 and 70 will receive less light than photocells 71 and 72 because the light transmission of liquid containing the chlorine indicating solution in cylinder 43 will be less than the light transmission through the chlorinated pool water in cylinder 47. This will cause a greater resistance of photocells 69 and 70 which, in turn, will cause an unbalance of the Wheatstone bridge. The amount of unbalance of the Wheatstone bridge is proportional to the amount of chlorine in the pool water which will be reflected as a voltage output from the Wheatstone bridge to amplifier 73, and this output in turn will be transmitted to time delay unit 81. In other words, the greater the amount of chlorine in the pool water, the greater will be the voltage output to amplifier 73. It is to be noted that because of the orientation of photcells 69 and 70 in the legs of the Wheatstone bridge, the voltage drop to amplifier 73 will be double as compared to the voltage drop obtained if only a single one of the photocells 69 and 70 was present. Amplifier 73 may be a No. 740 OP-AMP distributed by Radio Shack. Time delay unit 81 may be of any desired type. After two seconds the timer 24 turns power off to the blue light 67 and all of the photocells and the amplifier 73.
Based on the level of the signal received by the time delay unit 81, the latter will energize relay 82 for an inversely proportionate period of time which in turn will actuate chlorine feed pump 83 for that period of time, and the latter having a predetermined pumping cavity will provide a predetermined amount of chlorine to the pool through conduit 84 depending on the length of time for which the pump 83 is actuated. In the foregoing respect, the greater the voltage output from amplifier 73, the less will be the time delay from time delay unit 81 and the less will be the length of time of operation of pump 83.
The timer 24 will maintain power to the time delay 81 for approximately ten minutes. Time delay 81 in turn energizes relay 82 for up to 10 minutes, and then timer 24 will reverse the power to motor 25 to cause it to move back to its solid line position of FIG. 2. After two seconds, timer 24 shuts off all power to the electrical circuit of FIG. 3 and the timer will again be reset to produce the foregoing entire cycle when the filter pump is again turned on by the timer 13 as described above.
A manual switch 85 is associated with timer 24 to energize the circuit of FIG. 3 when it is desired to energize the chlorine level tester and regulator at will without having it operate in response to the actuation of the pool pump filter system as described above.
In a model of the above-described circuit of FIG. 3, the parts had the following approximate values and resistors 69, 70, 71 and 72 had the following approximate values when the blue light was energized and when there was clear water in cylinders 43 and 47:
______________________________________Part Resistor Value Ohms______________________________________69 2.4K70 2.6K71 2.1K72 4.2K74 0-12K75 0-12K77 0-10K80 0-10K______________________________________
The voltage supply is 18 volts. Cylinders 43 and 47 had volumes of approximately one cubic centimeter. The amount of indicator solution injected into cylinder 43 was approximately 0.06 cubic centimeters. The indication solution specifically was 0.1% OTO (contains ortholidine 0.1% and hydrochlorine acid 3.7%).
The above-described circuit having the above values was tested and provides the following results:
______________________________________Voltage output Chlorine level into amplifier 73 parts per million______________________________________.28 .4.40 .6.55 1.0.70 1.5.80 2.01.10 4.01.50 5.0______________________________________
While the above description has been directed to measuring the level of chlorine in swimming pool water, it will be appreciated that the same apparatus and procedure may be used with measuring other aspects of water chemistry such as bromine, pH and iron by the use of other suitable indicators and suitably colored lamps. When bromine is being tested, the above described circuit and the same indicator solution can be used as with chlorine.
The above circuit was also used to test pH. However, the indicator solution which was used was phenol red, and the lamp which was used was blue, as described above. The phenol red was the type marketed by Poolmaster, Inc. The following results were obtained from a test:
______________________________________Voltage output to amplifier 73 pH______________________________________.8 7.8.65 7.4.5 7.0.25 less than 7.0______________________________________
The above circuit was also used to test the concentration of dissolved iron. An "Iron Test Reagent" is used which is distributed by Biolab Inc. of Decatur, Ga. In this test a blue colored lamp was also used, as described above. The following results were obtained from a test:
______________________________________Voltage output to amplifier 73 Iron in PPM______________________________________ .85 1.01.20 3.02.75 5.5______________________________________
As noted above, a blue light was used for the above tests. However, it will be appreciated that lamps of other colors can also be used. The color of the lamp which is selected may be based on the spectrum of light that is most absorbed by the compounds in the cylinder as a result of mixing the reagent with the water to be tested. Generally one or more spectra of light will be absorbed to produce a color change.
While specific times have been set forth above in describing the cycles of operation, it will be appreciated that they are merely by way of example and not of limitation.
While preferred embodiments of the present invention have been disclosed, it will be appreciated that it is not limited thereto but may be embodied within the scope of the following claims. | Apparatus for measuring the level of an item in a liquid including first and second light transmitting cylinders, a first piston and an associated conduit for conducting liquid to the first cylinder, a second piston and an associated conduit for conducting liquid to the second cylinder, a third piston and an associated conduit for conducting indicator solution to the second cylinder, a light source for transmitting light through the first and second cylinders, and a detector for measuring the difference in light transmissibility of the liquids in the first and second cylinders and providing an output depending thereon. A method of testing the level of an item in a liquid including the steps of providing a first sample of the liquid containing the item, providing a second sample of the liquid with a measured amount of indicator solution therein, comparing the light transmissibility of the first and second samples, and providing an output which is a measurement of the level of the item in the liquid. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to computer software, and more particularly to a method, article, and system that provides for collaborative teaching and learning, while facilitating simultaneous and dynamic changes by multiple users.
[0003] 2. Description of the Related Art
[0004] A growing trend in education today is the use of the Internet to provide online educational coursework through electronic forums. Online courses offer exceptional accessibility, and are a flexible resource for gaining new skills, meeting professional development requirements, or advancing to a career with a program certificate. Online training allows for the convenience of “coming to class” whenever it's convenient, by choosing when and where to participate in class. Online courses are conducted according to a schedule, but there are no “live” classes to attend. Instead, lectures, coursework, and discussions all take place at one's convenience. Online students choose the place—at home, at school, at work—wherever they have access to a computer, modem, and an Internet Service Provider (ISP). Online students obtain the same high-quality instruction and course content that they demand, but without the day-to-day obstacles that prevent so many of them from pursuing their goals. With online learning, commuting to a campus is a thing of the past.
SUMMARY OF THE INVENTION
[0005] Embodiments of the present invention include a method, article, and system for collaborative teaching and learning, while facilitating simultaneous and dynamic changes by multiple users, the method includes: receiving a command to add or modify a topic record in a series of topic records in response to a user request; creating a new record in the event the received command is to add a new topic record; generating a modify token in the event the received command is to modify an existing topic record; deleting the modify token in response to completion of modifying the existing topic record; wherein the modify token prevents additional users from editing the existing topic record while the user is modifying the existing topic record; wherein in the event the modify token has been issued, the additional users can copy an existing record, modify the copy of the existing record, and assign a new name to the modified copy of the existing record while the existing record is being modified by the user; and wherein a collaboration engine generates and manages the modify token.
[0006] An article comprising one or more computer-readable storage media containing instructions that when executed by a computer enables collaborative teaching and learning, while facilitating simultaneous and dynamic changes by multiple users, wherein the method further includes: receiving a command to add or modify a topic record in a series of topic records in response to a user request; creating a new record in the event the received command is to add a new topic record; generating a modify token in the event the received command is to modify an existing topic record; deleting the modify token in response to completion of modifying the existing topic record; wherein the modify token prevents additional users from editing the existing topic record while the user is modifying the existing topic record; wherein in the event the modify token has been issued, the additional users can copy an existing record, modify the copy of the existing record, and assign a new name to the modified copy of the existing record while the existing record is being modified by the user; wherein a collaboration engine generates and manages the modify token; wherein in the event the user requests the subdivision of a topic record from the series of topic records the method further comprises: generating a subdivide token; releasing the subdivide token in response to the completion of the subdivision of the topic record; wherein in the event an additional user requests to edit the existing record while the subdivision token is in use by the user, a copy of the original record is generated to create a new record that is a subset of the original record; wherein in the event the modify token has been issued, the additional users can copy an existing record, modify the copy of the existing record, and assign a new name to the modified copy of the existing record while the existing record is being subdivided by the user; and wherein a collaboration engine generates and manages the subdivide token.
[0007] A system for collaborative teaching and learning, while facilitating simultaneous and dynamic changes by multiple users, the system includes: one or more server devices configured with a collaboration engine, a reconciliation engine, and a scheduling engine; the one or more server devices in communication with one or more client devices through a network; the server devices and the client devices configured to execute electronic software; wherein the electronic software is resident on storage mediums in signal communication with the client and server devices; wherein the electronic software comprises a series of instructions configured for: receiving a command to add or modify a topic record in a series of topic records in response to a user request; creating a new record in the event the received command is to add a new topic record; generating a modify token in the event the received command is to modify an existing topic record; deleting the modify token in response to completion of modifying the existing topic record; wherein the modify token prevents additional users from editing the existing topic record while the user is modifying the existing topic record; wherein in the event the modify token has been issued, the additional users can copy an existing record, modify the copy of the existing record, and assign a new name to the modified copy of the existing record while the existing record is being modified by the user; wherein the collaboration engine generates and manages the modify token; wherein in the event the user requests the subdivision of a topic record from the series of topic records the method further comprises: generating a subdivide token; releasing the subdivide token in response to the completion of the subdivision of the topic record; wherein in the event an additional user requests to edit the existing record while the subdivision token is in use by the user, a copy of the original record is generated to create a new record that is a subset of the original record; wherein in the event the modify token has been issued, the additional users can copy an existing record, modify the copy of the existing record, and assign a new name to the modified copy of the existing record while the existing record is being subdivided by the user; and wherein the collaboration engine generates and manages the subdivide token.
TECHNICAL EFFECTS
[0008] As a result of the summarized invention, a solution is technically achieved for a method, article, and system for providing collaborative teaching and learning, while facilitating simultaneous and dynamic changes by multiple users.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0010] FIG. 1 illustrates a Venn diagram showing the relationships between organizations, mentors and students in an educational system with private and open teams according to embodiments of the invention.
[0011] FIG. 2 is a domain model illustrating the relationships between entities required for a learning system according to embodiments of the invention.
[0012] FIG. 3 shows a flowchart for a method for adding and modifying topics in a learning system that matches topics, teachers, and students according to embodiments of the invention.
[0013] FIG. 4 shows a flowchart for a method for scheduling topics and courses in a learning system that matches topics, teachers, and students according to embodiments of the invention.
[0014] FIG. 5 shows a flowchart for a method for building a course in a learning system that matches topics, teachers, and students according to embodiments of the invention.
[0015] FIG. 6 is a block diagram illustrating an exemplary system that may be utilized to implement exemplary embodiments of the invention.
[0016] FIG. 7 is a functional block diagram of a learning system according to embodiments of the invention.
[0017] The detailed description explains the preferred embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION
[0018] Even with the advent of online education, many problems arise due to the coarse grained nature of traditional courses that offer training on particular subjects. Students encounter a significant overlap in content delivered through training they have already received, thereby diminishing the effectiveness of the course. In addition, there are a limited number of instructors available who have the expertise in all of the subjects within a course. Finally, collaboration programs presently do not allow simultaneous updates of records by different users, because a second record update will overwrite changes made by the first record update.
[0019] Embodiments of the invention provide a system and method that addresses the aforementioned problems that are associated with traditional educational approaches. Embodiments of the invention breakdown courses into fine-grained topics, where experts in particular subjects may define their own topics to share. In embodiments of the invention, individuals may sign up to be instructors to teach particular topics, while students may build their own courses by selecting topics. Students may also request topics that are not yet available. Individuals or mentors may build courses for their proteges by selecting topics. Embodiments of the invention, determine if topics are similar in order to increase the pool of instructors in a given subject area, while also matching up students and instructors in classes based on a certain threshold of requests for a topic or similar topic. In addition, embodiments of the invention maintain calendars for instructors and automatically schedule classes. Finally, in embodiments of the invention a collaboration engine manages tokens by modifying and subdividing the tokens to permit multiple access and simultaneous modification to records, under a set of system modification rules, while a reconciliation engine eliminates duplicate courses and topics.
[0020] Embodiments of the invention utilize software that capture topics, and present the topics for students to select. Participants who wish to teach a topic, or group of topics, may indicate their preferences via the software. The software will allow the students to construct their own classes from the list of topics. The software will match the topics and groups of topics with instructors. The software will determine if there is a need to increase the pool of instructors in a given topic. The software will match the topics with instructors with students and automatically schedule classes on the students and instructors calendars. A graphical user interface (GUI) may be implemented with the software to carryout embodiments of the learning system.
[0021] Embodiments of the invention may be offered as a software service on the Web, and may be managed from a central area. In an enterprise environment, organizations may have a directory with permissions for users. Each enterprise may have their own virtual service, where each enterprise may protect their content, and may also share their content if they choose to, as illustrated by the Venn diagram of FIG. 1 .
[0022] FIG. 1 illustrates a Venn diagram 100 showing the relationships between organizations, mentors and students in an educational system with private and open teams according to embodiments of the invention. The circles 102 represent separate organizations that are made up of one or more teams ( 104 , 106 ). The teams may be open 104 or private 106 . In embodiments of the invention, a pool of mentors, a variety of topics, and an audience of students may cross-organizational boundaries. The extent to which mentors and topics are made available across organizational boundaries is in the control of the originating organization through the use of private 106 or open teams 104 . Individuals belonging to teams ( 104 , 106 ) contained within the organizational circles 102 define access to topics and mentors. Overlapping organizational circles 102 show areas where topics and mentors are available across organizations.
[0023] FIG. 2 is a domain model 200 illustrating the relationships between entities required for a learning system according to embodiments of the invention. The domain model 100 is a model of the structure and relationships of real world entities required to support embodiments of the invention. The notation for the domain model 100 is defined using the Unified Modeling Language (UML). UML is a standardized specification language for object modeling. UML is a general-purpose modeling language that includes a graphical notation used to create an abstract model of a system, referred to as a UML model. Key elements within the domain model 200 of embodiments of the invention include topics 202 , learning paths 204 , material 206 , teams 208 , users 210 , experts 212 , contributors 214 , and learners 216 .
[0024] Continuing with FIG. 2 , a topic 202 is a nugget of learning, which is fine grained enough that it might be learned in a relatively short amount of time. The fine-grained nature of topics 202 , allows for topics 202 to be organized and re-organized into groups or learning paths 204 that provide broader learning objectives. The fine-grained nature of topics 202 also increases the likelihood of learners 216 to eventually become experts 212 that may train other learners 216 on the topic 202 . A learning path 204 defines a collection of topics 202 that when learned together result in a completion of a learning objective. Material 206 is all the content that makes up a topic 202 . Material 206 may be captured in a file that is uploaded, may be a uniform resource locator (URL) link to external content, or may be a Wiki. Material 206 may be shared by more than one topic 202 . A team 208 is formed with members with common concerns that band together to facilitate team specific learning. A team 208 may express interest in relevant topics 208 and learning paths 204 . A user 210 is any individual that performs a role within this invention. A user 210 may simultaneously be acting in many different roles (e.g., contributors 214 and experts 212 ) depending on their involvement in individual topics 202 . An expert 212 is someone one who may be consulted on a topic 202 on demand, and who may be willing to teach topics 202 in live or virtual interactive classes. An expert 212 may also accept requests to teach topics 202 . Any user 210 may sign up to become an expert 212 . A contributor 214 helps to define the content for a topic 202 , or learning path 204 . A user 210 automatically becomes a contributor 214 when adding, editing or removing topic 202 materials 206 . Finally, a learner 216 is someone who has learned a topic. A user 210 automatically becomes a learner 216 , if they view materials 206 for a topic 202 , and are not already identified as a contributor 214 or expert 212 for the topic 202 .
[0025] FIG. 3 shows a flowchart for a method for adding and modifying topics in a learning system that matches topics, teachers, and students according to embodiments of the invention. The process starts (block 300 ) with a user either adding (decision block 302 ) or modifying a topic (decision block 306 ). If the user wants to add a new topic (decision block 302 is Yes), a new topic is created (block 304 ). If the user wants to modify an existing topic (decision block 306 is Yes), the collaboration engine (see FIG. 7 ) will issue a modify token (block 308 ) that allows the to modify the topic (block 310 ). The modify token prevents other users from editing the record while the user is modifying the record. The issued modify token, however, does not prevent others from copying the record, and modifying it with a different assigned name, to create a new subset of the record that the other users in a learning system may modify. The copying of the record is used for subdividing a topic record. The modify token is deleted following the users completion of modification.
[0026] Continuing with FIG. 3 , if the user wants to subdivide the topic record (decision block 312 is Yes), a sub divide token is issued (block 314 ). The subdivide token does not prevent others from editing the record at the same time, by allowing a copy of the original record in order to create a new record that is a subset of the original record. Copying of the original record will occur even if there is someone editing the original record. The subdivide token is released following completion of the subdivision. A new subdivide record is created only if changes have occurred to the original record, otherwise the copy of the record is deleted. If the user wants to reconcile topics (decision block 316 ), a reconciliation of topics occurs (block 316 ), and duplicate topic records are eliminated. If the user wants to exit the learning system (decision block 318 is Yes), the process ends (block 320 ), or else the process repeats.
[0027] FIG. 4 shows a flowchart for a method for scheduling topics and courses in a learning system that matches topics, teachers, and students according to embodiments of the invention. The process starts (block 400 ) when the user wants to select topics and courses (decision block 402 is Yes), and the user selects the topics and courses (block 404 ), and a schedule engine (see FIG. 7 ) matches students with topics and courses. If the user wants to exit the learning system (decision block 408 is Yes), the process ends (block 410 ), or else the process repeats.
[0028] FIG. 5 shows a flowchart for a method for building a course in a learning system that matches topics, teachers, and students according to embodiments of the invention. The process starts (block 500 ) when a user wants to build or create a course (decision block 502 is Yes), and the user selects the topics for the courses (block 504 ). The course is built and validated for uniqueness (block 506 ). If the course is unique (decision block 508 is Yes) the process ends (block 512 ), otherwise the user is prompted as to whether they want to continue to build the course (decision block 510 ) and the process repeats or ends (block 512 ).
[0029] FIG. 6 is a block diagram illustrating an exemplary system 600 that may be utilized to implement a learning system according to embodiments of the invention. The system 600 includes remote devices in the form of multimedia devices 602 , and desktop computer devices 604 configured with display capabilities 614 for implementing graphical user interface (GUI) aspects of the invention described herein. The multimedia devices 602 may be mobile communication and entertainment devices, such as cellular phones and mobile computing devices that are wirelessly connected to a network 608 . The multimedia devices 602 have video displays 618 and audio outputs 616 for implanting the GUI described herein. The network 608 may be any type of known network including a fixed wire line network, cable and fiber optics, over the air broadcasts, satellite 620 , local area network (LAN), wide area network (WAN), global network (e.g., Internet), intranet, etc. with data/Internet capabilities as represented by server 606 . Communication aspects of the network are represented by cellular base station 610 and antenna 612 .
[0030] Software for carrying out features of embodiments of the invention may be resident on the individual multimedia devices 602 and desktop computers 604 , or stored within the server 606 or cellular base station 610 .
[0031] FIG. 7 is a functional block diagram of a learning system server 700 (corresponding to the server 606 of FIG. 6 ) according to embodiments of the invention. The server 700 has a collaboration engine 702 , a reconciliation engine 704 , and a scheduling engine that are configured to create and modify courses and topics in a learning system. The collaboration engine 702 manages tokens by modifying and subdividing tokens to permit multiple access and simultaneous modification to records, under a set of system modification rules. The reconciliation engine 704 eliminates duplicate courses and topics. The scheduling engine 706 is configured to schedule courses, topics, teachers, and students. Storage units 708 and 710 store information related to courses and topics, and schedules, respectively, and is in electrical communication with the server 700 . The server communicates with users via network 712 (corresponding to the network 608 of FIG. 6 ).
[0032] The capabilities of the present invention can be implemented in software, firmware, hardware or some combination thereof.
[0033] As one example, one or more aspects of the present invention can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer usable media. The media has embodied therein, for instance, computer readable program code means for providing and facilitating the capabilities of the present invention. The article of manufacture can be included as a part of a computer system or sold separately.
[0034] Additionally, at least one program storage device readable by a machine, tangibly embodying at least one program of instructions executable by the machine to perform the capabilities of the present invention can be provided.
[0035] The flow diagrams depicted herein are just examples. There may be many variations to these diagrams or the steps (or operations) described therein without departing from the spirit of the invention. For instance, the steps may be performed in a differing order, or steps may be added, deleted or modified. All of these variations are considered a part of the claimed invention.
[0036] While the preferred embodiments to the invention has been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described. | A method for collaborative teaching and learning, while facilitating simultaneous and dynamic changes by multiple users, includes: receiving a command to add or modify an existing topic record in a series of topic records in response to a user request; creating a new record in the event the received command is to add a new topic record; generating a modify token in the event the received command is to modify an existing topic record; deleting the modify token in response to completion of modifying the existing topic record; wherein the modify token prevents additional users from editing the existing topic record, but allows for the existing record to copied and modified while the first user is modifying the existing topic record; and wherein a collaboration engine generates and manages the modify token. | 6 |
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