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CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit under 35 USC §119(e) of U.S. Provisional Application Ser. No. 60/227,701 filed Aug. 24, 2000, entitled “Cryogenic Treatment of Cookware and Bakeware”.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to cookware and, more particularly, to stick resistant cook surfaces and methods of making the cook surface more stick resistant and more resistant to scratching, abrasion and marring.
2. Description of the Prior Art
In vessels that are used for cooking or baking, such as pots or pans and the like, it is desirable that the vessel warms or heats evenly across its bottom and sides when placed on a stovetop burner or into an oven. It is also desirable that the inner surface of the vessel, i.e., the cook surface that comes in contact with the food being prepared, be constructed such that the food being prepared does not deposit, adhere or stick to the inner surface. Although the properties above are important, it is also vital that cooking or baking vessels be resistant to damage if dropped as well as resistant to corrosion resulting from regular use and cleaning.
The use of multi-layer composites or clad metal products of three metal layers or less is well-known in the cookware and bakeware art. For example, stainless steel cooking utensils with a copper bottom are known, as well as aluminum cored stainless steel. A particular problem with cookware made from these types of materials is an inability to get quick and even heat transfer over the entire pan.
Many attempts have been made to overcome the above-mentioned problem. U.S. Pat. Nos. 4,103,076; 4,246,045; 4,646,935 and others to Ulam disclose multi clad cooking vessels. My more recent patents, U.S. Pat. Nos. 6,267,830 and 6,109,504 to Groll, are directed to improved copper core multi-layer component cookware and griddle plate, respectively. The disclosures of the above-mentioned Ulam patents as well as my own patents are incorporated by reference herein. An example of the disclosed cooking utensils is a nine-ply material consisting of a copper core clad on each side with layers of pure and alloyed aluminum, which is, in turn, clad on both sides with stainless steel. The utensils disclosed provide improved heat distribution and stick resistance, but there remains an ever-present demand to improve stick resistance of bare metal cook surfaces as well as to increase the mar resistance and increase the life of stick resistant coatings.
In order to overcome the problem of food sticking to the cooking surface, it has become common practice to coat the cooking surface of cooking or baking vessels with non-stick materials such as amorphous fluorocarbon polymers. Examples of commercially available amorphous fluorocarbon polymers are those sold under the trade name Teflon® by E. I. DuPont de Nemours Co., Inc. of Wilmington, Del. Examples of these types of coatings used in cookware and bakeware are disclosed in U.S. Pat. No. 5,863,608 to Swisher et al., which is also incorporated by reference herein. However, amorphous fluorocarbon polymer coated vessels for cooking and baking tend to lose their non-stick quality over time as the coating can be easily scratched, abraded or otherwise marred or worn away because of its generally soft texture and as the fluorocarbon polymer loses its lubricity over time. These fluorocarbon polymer coatings are oftentimes referred to as “PTFE” coatings.
I have found that metal surfaces can have improved non-stick or reduced friction properties if they are made harder. In the case of multi-layer clad cookware, where softer heat conducting metals such as aluminum and/or copper are used as the core metal, which is then laminated on both sides with a harder metal such as stainless steel, the cook surface is generally softer than might be attained without a laminated metal. Metals, such as stainless steel, can be hardened by austenitizing and tempering at very high temperatures. When a softer metal core, such as copper or aluminum, is used in a laminate, the ideal temperatures for tempering or austenitizing stainless steel would melt the lower melting point core metal. Such a heat treatment would result in warping or deformation of the multi-layer, composite cooking utensil. Therefore, optimum hardening temperatures for tempering and austenitizing steel cannot be used with composite metals containing aluminum and/or copper. This results in a less hard and less than ideal cook surface.
There remains an unmet need for cookware and bakeware that have excellent and uniform heat transfer properties while providing a reliable and durable non-stick cooking surface, be it a bare metal surface, a PTFE type coating or other coated surfaces such as vapor deposited ceramic nitrides.
SUMMARY OF THE INVENTION
The present invention is directed to cookware, bakeware and other food preparation surfaces such as grills and griddles that have increased surface hardness and improved stick resistance and longer life stick resistant coatings, in the case of coated cookware. The instant cookware, bakeware and other food preparation surfaces are made from metals, either bare or precoated with a non-stick coating, which have been cryogenically processed to increase their hardness.
The present invention is further directed to a method of making cookware, bakeware and like food preparation surfaces, hereinafter collectively referred to as “cookware”. The method includes the steps of forming a clad sheet of metal with a core of aluminum or copper laminated on one or both sides with stainless steel, aluminum or the like. The clad sheet is then cryogenically tempered at less than −100° F. and more preferably less than −275° F. Ideally, the cookware, in either a bare or coated condition, is subjected to a cyclic cryogenic treatment wherein the temperature is cycled between about −100° F. to −280° F. or −300° F. or lower for a period of time and then subjected to a temper treatment at about +280° F. to +300° F.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a typical cookware vessel according to the present invention;
FIG. 2 is an enlarged sectional view showing the wall of a cookware vessel according to an embodiment of the present invention;
FIG. 3 is an enlarged sectional view showing the wall of a cookware vessel according to an embodiment of the present invention;
FIG. 4 is an enlarged sectional view showing the wall of a cookware vessel according to an embodiment of the present invention;
FIG. 5 is an enlarged sectional view showing the wall of a cookware vessel according to an embodiment of the present invention; and
FIG. 6 is an enlarged sectional view showing the wall of a cookware vessel according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a sectional view of a cooking utensil 10 constructed for use in connection with the present invention. Cooking utensil 10 preferably has a horizontal bottom wall 12 , upstanding side walls 14 , and one or more handles 16 . The vessel may be formed from a single blank of metal which may have a plurality of plies roll bonded together using processes known in the art and subsequently cryogenically hardened as will be explained below. The utensil 10 may take various forms including the illustrated stockpot, skillets, fry and sauce pans, griddles, or numerous other bakeware and cookware items.
The wall of utensil 10 schematically shown in FIG. 2 has a core layer 20 made of a good heat conducting metal, such as aluminum or copper. An outer layer 22 made of a hard metal, such as stainless steel or carbon steel, is clad on an outer side 21 of core layer 20 . An inner layer 18 , made of a hard metal, such as stainless steel or carbon steel, is clad on an inner side 19 of core layer 20 . The inner layer 18 defines the cook surface of the utensil.
Another example of a utensil wall useful in connection with the present invention is shown in FIG. 3, which has a core layer 28 made of a good heat conducting metal, such as aluminum or copper. An outer layer 30 made of a hard metal, such as stainless steel or carbon steel, is clad on an outer side 29 of core layer 28 . An inner layer 26 made of a hard metal, such as stainless steel or carbon steel, is clad on an inner side 27 of core layer 28 . A non-stick coating 24 of PTFE or a vapor deposited layer of a ceramic nitride such as titanium nitride or zirconium is applied to inner cook surface 25 of inner layer 26 .
A further example of a utensil wall which is useful in connection with the present invention is shown in FIG. 4, which has a core layer 36 made of copper. An outer intermediate clad layer 38 made of aluminum is clad on an outer side 37 of core 36 . An outer layer 40 made of a hard metal, such as stainless steel or carbon steel, is clad on an outer side 39 of outer intermediate clad layer 38 . Conversely, it is also known in the art to dispense with the steel layer 40 and merely anodize the exposed surface of the aluminum layer 38 . An inner intermediate clad layer 34 made of aluminum is clad on an inner side 35 of core 36 . An inner layer 32 made of a hard metal, such as stainless steel or carbon steel, is clad on an inner side 33 of inner intermediate clad layer 34 .
Still another example of a utensil wall which is useful in connection with the present invention is shown in FIG. 5, which has a core layer 48 made of copper. An outer intermediate clad layer 50 made of aluminum is clad on an outer side 49 of core 48 . An outer layer 52 made of a hard metal, such as stainless steel or carbon steel, is clad on an outer side 51 of outer intermediate clad layer 50 . As in the embodiment of FIG. 4, the steel layer 52 can be eliminated by anodizing the outer surface of the aluminum layer 50 . An inner intermediate clad layer 46 made of aluminum is clad on an inner side 47 of core 48 . An inner layer 44 , made of a hard metal, such as stainless steel or carbon steel, is clad on side 45 of inner intermediate clad layer 46 . A non-stick coating 42 is applied to an outer surface 43 of inner layer 44 .
A final example of a utensil wall which is useful in connection with the present invention is shown in FIG. 6, in the form of a flat griddle plate which includes a base metal 56 which is a hard metal, such as stainless steel, carbon steel or titanium. A non-stick coating 54 is applied to surface 58 of base metal 56 .
The non-stick coating can be any such coating known in the art. Examples of commercially available PTFE amorphous fluorocarbon polymers are those sold under the trade name Teflon® by E. I. DuPont de Nemours Co., Inc. of Wilmington, Del. The amorphous fluorocarbon polymer coating can be applied directly to the metal surface. Preferably, an adhesion or primer layer is applied to the metal surface and an amorphous fluorocarbon polymer containing coating is applied on top of the adhesion layer. Most preferably, an adhesion layer is applied to the metal surface, a protective or midcoat layer is applied on top of the adhesion layer to help provide scratch resistance, and an amorphous fluorocarbon polymer containing coating is applied on top of the midcoat layer. U.S. Pat. No. 5,240,775 to Tannenbaum, herein incorporated by reference, discloses such non-stick coatings.
Alternatively, the non-stick coating can be a metal nitride or sulfide containing coating applied to the metal surface. Representatives of suitable metallic compounds for use herein are nitrides or sulfides of tungsten, molybdenum, lead, tin, copper, calcium, titanium, zirconium, zinc, chromium, iron, antimony, bismuth, silver, cadmium and alloys and mixtures thereof. Vapor deposited coatings of TiN, ZrN and WS 2 are presently preferred.
The non-stick coating composition of the present invention may also be a composition that contains both an amorphous fluorocarbon polymer and a metal nitride or sulfide. Such surface coating compositions are disclosed in U.S. Pat. Nos. 5,262,241 and 5,403,882 to Huggins, incorporated herein by reference.
The non-stick coating composition can be applied to the metal surface in any manner known in the art. For example, the non-stick coating can be applied by spraying, dipping or rolling the coating onto the metal surface. A preferred method for applying the non-stick coating to the metal surface is by vapor deposition. Such methods are well-known in the art, such as the methods disclosed in U.S. Pat. No. 5,340,604 to Atsushi which is also incorporated by reference herein. The non-stick coating will be of a thickness to allow it to perform its function. The thickness can vary from a few angstroms to several microns.
The metal substrate used to make the cooking utensils of the present invention can be any suitable metal known in the art for making such products. Acceptable metals include copper, aluminum, stainless steel, carbon steel, iron, Hasteloy® and titanium. Preferably, the metal will be a clad composite metal substrate with a core having good thermal conductivity, such as copper and/or aluminum. Examples of acceptable clad metal composite substrates are shown in FIGS. 2 and 4. Additional examples of acceptable composite metal substrates are disclosed in U.S. Pat. Nos. 4,103,076; 4,246,045; and 4,646,935 to Ulam, and U.S. Pat. Nos. 6,109,504 and 6,267,830 to Groll which collectively are, likewise, incorporated by reference herein.
The cooking utensils of the present invention are cryogenically tempered to harden the metal substrate and non-stick coating, if applied to the inner cook surface. Cryogenic tempering closes and refines grain structures, reduces retained stresses, reduces wear and surface roughness; increases dimensional stability and increases durability and hardness. It is believed that the improved hardness of the metal or non-stick surface leads to an improved non-stick characteristic for the resulting cooking utensil.
The cooking utensil may be cryogenically tempered as follows: the utensils are slowly cooled to less than −100° F., preferably less than −300° F. Any suitable rate of cooling can be used; however, it is presently preferred that the utensil is cooled at about one degree per minute. The utensil is then held at −100° F., preferably less than −300° F. for about one to sixty hours, depending on the particular utensil. After the cryogenic tempering, the utensil temperature is slowly raised to about 2500 to 350° F. Any suitable rate of heating can be used, but it is preferred that the utensil is heated at about one degree per minute. The utensil is then cooled to ambient temperature.
The cryogenic treatment is applicable to cookware having either a bare cooking surface or one coated with a PTFE or vapor deposited meal nitride or sulfide non-stick surface. Another presently preferred method of cryogenically tempering the cookware of the present invention comprises the steps of slowly cooling the cookware from an ambient temperature to a temperature below about −100° F., followed by cooling to about −300° F. and repeating the steps. The thermal cycle of cooling and heating the cookware at controlled rates between −100° F. and about −300° F. is repeated a number of times, such as, for example, 6-8 times wherein each cycle between heating and cooling may take about 1 to 1½ hours. After the last cycle, the cookware may be heated at a controlled rate to about +200° F.-300° F. and held for several hours for tempering purposes. The cryogenic tempering does not have to be applied to the final formed cooking utensil. Alternatively, a metal or metal clad sheet can be cryogenically tempered as described and subsequently formed into a cooking utensil. It is also contemplated as part of the present invention that the utensil, metal or clad metal may be coated with a non-stick coating, such as Teflon® or other non-stick coatings such as vapor deposited ZrN or TiN, WS 2 and the like, prior to cryogenic tempering. Cryogenic tempering of the coated utensil or metal sheet serves to harden both the substrate metal as well as the non-stick coating. In this way, the non-stick surfaces have improved non-stick properties, are more resistant to scratching, and retain their non-stick property over a longer period of time.
While multi-layer composite metal cookware is ideally suited for cryogenic hardening according to the present invention, it will be understood that cooking utensils of a single ply of, for example, iron, aluminum, stainless steel, titanium and the like, both bare and coated with the above-disclosed coatings, fall within the intended scope of the present invention.
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention.
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A method of making cookware and bakeware having a stick resistant and mar resistant cook surface comprising the steps of providing a cooking utensil having a cook surface, and cryogenically treating the cooking utensil at one or more selected temperatures comprising −100° F. to −300° F. or lower to harden said cook surface. The cooking utensil may have a bare metal cook surface, or it may be coated with a stick resistant coating such as one of a PTFE, metal nitride or sulfide coating or combinations thereof prior to the cryogenic hardening treatment.
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FIELD OF THE INVENTION
[0001] The present invention relates to fastening structure for coupling soil nails and reinforced soil retaining wall.
BACKGROUND OF THE INVENTION
[0002] In recent years, reinforced soil retaining walls have been extensively used to replace conventional concrete wall for fill work. For cutting areas, soil nailings are developed to reinforce the existing ground for preventing landslides. However, there is a need to combine soil nailing and reinforced soil structure if both cut and fill conditions are encountered at the same time.
SUMMARY OF THE INVENTION
[0003] The primary object of the invention is to fulfill aforesaid needs. The invention provides a fastening structure to couple soil nailing and reinforced soil retaining wall for forming an integrated structure.
[0004] Another object of the invention is to utilize resistant force of the reinforced retaining wall to increase the stability of the soil nailing on the excavation site and offers a construction method safer than conventional soil nailing construction technique.
[0005] Yet another object of the invention is to fasten the soil nailing and the reinforced soil retaining wall to become an integrated body to prevent sliding plane from passing through the interface of the two.
[0006] In order to achieve the foregoing objects, the retaining structure of the invention includes soil nailings, a fastening structure and a reinforced retaining wall. The soil nailings are installed and buried into the earth through the wall of the work site, and then the fastening structure is assembled to the soil nailing. Finally, the reinforced retaining wall is fastened to the fastening structure to complete the construction of the invention.
[0007] The construction thus combines and integrates the soil nailing and reinforced soil walls to increase the stability of the whole system. After a number of soil nailings have been installed into the slope wall, zinc coated and spot soldered wire meshes are laid with non-woven fabrics and water permeable gravel materials on sloped wall over the soil nailings, then fasten the reinforced retaining wall to the soil nailings.
[0008] The following is a detailed description of the invention with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic view of excavating a construction site on a slope land.
[0010] [0010]FIG. 2 is a schematic view of first soil nailing installation.
[0011] [0011]FIG. 3 is a schematic view of the completed set of soil nailings.
[0012] [0012]FIG. 4 is a schematic view of zinc coated and spot soldered wire meshes, non-woven fabrics and water permeable gravel materials laid on the excavated area.
[0013] [0013]FIG. 5A is a schematic view of fastening the reinforced retaining wall to soil nailing.
[0014] [0014]FIG. 5B is an enlarged view of FIG. 5A.
[0015] [0015]FIG. 6 is a schematic view of the fastening structure of the invention, coupling with a soil nailing.
[0016] [0016]FIG. 7 is an enlarged view of FIG. 5B, for a single reinforced layer.
[0017] [0017]FIG. 8 is a schematic view of the invention with the reinforced materials (geogrid or grill meshes) fastened to soil nailing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to FIGS. 1, 2 and 3 for an embodiment of the invention, prior to the construction and installation of the invention, setup a work site 1 by excavating a slope land. After the work site 1 is ready, install soil nailing 2 into the earth through the wall of the work site 1 . After complete installation of the soil nailing 2 , lay a zinc-coated and spot-soldered wire meshes 3 , non-woven fabrics 4 and water permeable gravel materials 5 on the slope wall over the soil nailing (as shown in FIG. 4) to ensure safety and convenience of the work in the later phases. Then the work for fastening the soil nailing 2 and reinforced retaining wall 6 (as shown in FIG. 5A) may be started.
[0019] Referring to FIGS. 5B and 6, to fasten the soil nailing 2 and reinforced retaining wall 6 , each soil nailing 2 is engaged with a fastening means 7 . The fastening means 7 includes a coupling element 71 and a strut 72 made of solid or hollow steel pipes. The coupling element 71 has an annular sleeve 712 to hold the strut 72 and a flange 711 engaging with the soil nailing 2 through a fasten element 21 made of a screw nut. A series of soil nailing 2 may be linked and fastened by a series of struts 72 (as shown in FIG. 8).
[0020] Referring to FIGS. 7 and 8, after the fastening means 7 is assembled on the soil nailing 2 , install the reinforced retaining wall 6 on the fastening means 7 .
[0021] The reinforced retaining wall 6 includes a reinforced grill mesh or geogrid 61 , a support beam 62 , a rope 63 and a clamp means 64 . The reinforced grill mesh or geogrid 61 is to reinforce retaining earth (not shown in the drawings).
[0022] The support beam 62 may be made of stainless steel pipe and is wrapped by the reinforced grill mesh or geogrid 61 . The reinforced grill mesh or geogrid 61 wraps around the support beam 62 and is overlapped and engaged with another reinforced grill mesh or geogrid 61 by clip devices 65 .
[0023] The rope 63 may be made of a steel cable to wind around the support beam 62 and strut 72 for anchoring the reinforced grill mesh or geogrid 61 . The rope 63 may be slid on the strut 72 up or down without breaking away.
[0024] The clamp means 64 clamps and fastens two free ends of the rope 63 after winding around the support beam 62 and strut 72 so that the reinforced grill mesh or geogrid 61 will be harnessed by the strut 72 without slipping away.
[0025] During construction of one layer of the reinforced retaining wall 6 , lay the reinforced grill mesh or geogrid 61 on the work site 1 , then lay and pile up sacks of retaining earth (not shown in the drawings) on the reinforced grill mesh or geogrid 61 and compact to desired density. Then wind the reinforced grill mesh or geogrid 61 around the support beam 62 to couple with another layer of reinforced grill mesh or geogrid 61 through the clip devices 65 . Then wind the rope 63 around the support beam 62 and strut 72 , and clamp the rope 63 at the two free ends thereof by the clamp means 64 to complete the installation of the reinforced retaining wall 6 .
[0026] As the rope 63 may be slid up or down on the strut 72 according geographical conditions, the fastening means may be free from stress concentration resulting from settlement of foundation or sagging of the reinforced materials.
[0027] Furthermore, the fastening means 7 can integrate the soil nailing 2 and reinforced retaining wall 6 to become one rigid body. Sliding at the interface between the two can be prevented from incurring. Construction thus can be done more rapidly to save time and work. Consumption of the soil nailing 2 can also be reduced, and the foundation width of the reinforced retaining wall 6 can also be decreased.
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A fastening system is invented for fasten the soil nails (which are used in cut areas) and the reinforced retaining structures (which are used in fill areas). The system is to connect the two and form an integrated body to prevent sliding plane passing through the interface of the two. The fastening system includes coupling elements, struts, flanges, steel pipes, cables, annular sleeve and clamps.
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[0001] This application claims the benefit of U.S. Provisional Application No. 61/670,310 filed Jul. 11, 2012, the entire contents of which is herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This disclosure relates to pressure transmitters and, more particularly, to a self-powered pressure transmitter for an objective measurement of pressure.
BACKGROUND
[0003] Monitoring of blood pressure by caregivers has become a well-established bio-monitoring tool. Knowledge of a patient's blood pressure is often essential to properly assess the patient's medical condition. Hypertension, hypotension, and shock are some examples of conditions monitored via blood pressure. Frequently, a sphygmomanometer (an instrument, often attached to an inflatable air-bladder cuff and used with a stethoscope, for measuring blood pressure in an artery) is used for such monitoring.
[0004] Continuous monitoring of the blood pressure enables medical personnel to immediately detect changes in the cardiovascular system indicating stress, and to respond rapidly with the appropriate action. While a sphygmomanometer is effective, continuous use of a sphygmomanometer is inconvenient. Accordingly, various approaches for continuous monitoring of blood pressure have been developed. One common approach involves inserting a needle into the artery or vein of a patient and exposing a catheter to the fluid pressure in the artery or vein. A sterile solution fills the catheter and the pressure of the cardiovascular system at that point in the body is transmitted through the sterile solution to a fluid pressure sensing device connected to the catheter outside the patient's body. A pressure-sensing device such as a pressure transducer is then used to produce an electric signal proportional to the fluid pressure of the blood at the open end of the catheter. While this type of system is useful when an individual is substantially immobilized, it is not useful for patients who are not confined to a bed.
[0005] One approach that overcomes some of the limitations of the above systems is the use of an implantable pressure monitor. U.S. Patent Publication Number 2004/0193058 describes an implantable pressure monitor. While the device in the '058 publication measures the blood pressure of an individual, the '058 device does not provide information as to the context of the particular blood pressure reading. For example, while a given blood pressure may be acceptable during and shortly after heavy exercise, that same blood pressure while an individual has been at rest for a period of time may indicate a problem in the individual.
[0006] Therefore, an improved implantable blood pressure sensor is needed. It would be advantageous if the blood pressure sensor provided insight as to the context of a particular blood pressure reading. A system which did not require external power sources to operate would be further beneficial.
SUMMARY
[0007] The embodiments herein provide a device and method for measuring blood pressure of a body while providing context of the blood pressure reading. In one embodiment, an implantable pressure sensor assembly includes an accelerometer that produces current as an individual moves. The produced current charges a capacitor. When the capacitor is charged to a predetermined threshold, a gate element automatically discharges the capacitor. The discharged current is directed to a pressure sensor which detects the blood pressure of the individual and generates a signal associated with the detected blood pressure. The accelerometer thus produces the power used by the implantable pressure sensor assembly. Additionally, the period required to charge the capacitor is directly related to the amount of activity of the user. Thus, more pressure readings are obtained as the activity of the user increases. The frequency of the readings is thus directly related to the activity level of the individual.
[0008] In another embodiment, a pressure sensor assembly includes an accelerometer configured to produce a first current upon movement of the accelerometer, a capacitor configured to receive the first current thereby charging the capacitor, a gate element operably connected to the capacitor and configured to discharge a second current from the capacitor upon the capacitor attaining a threshold voltage, a pressure sensor configured to receive the discharged current to produce a first signal corresponding to at least one pressure reading of the pressure sensor, and a transmitter operably connected to the pressure sensor and configured to transmit a second signal based upon the first signal to an external device configured to store data corresponding to the second signal.
[0009] In yet another embodiment, a method for measuring blood pressure by a pressure sensing assembly, includes attaching a pressure sensing assembly with an accelerometer to an individual, producing a first current with the accelerometer, charging a capacitor with the first current, automatically discharging a second current from the capacitor with a gate element when the capacitor reaches a predetermined voltage, powering a pressure sensor with the second current to generate a first signal associated with at least one first pressure sensed by the pressure sensor, transmitting a second signal based upon the first signal to an external device, and storing the second signal at the external device.
[0010] In some embodiments an RFID (Radio frequency identification) element is provided within the pressure sensor assembly. The RFID provides a unique identification code for the pressure sensor assembly. Accordingly, when the pressure sensor assembly transmits a pressure reading signal to an external receiver, the unique identification code is also transmitted.
[0011] In some embodiments, a system includes an external device which receives the signal transmitted by the pressure sensor assembly. The external device stores and displays the received data. The external device can be used to provide feedback to the user of the user's activity level and associated blood pressure.
[0012] In one embodiment, a method for measuring blood pressure with a pressure sensor assembly includes producing a current using an accelerometer. The produced current is used to charge a capacitor. A gate element automatically discharges the capacitor when the capacitor is charged to a predetermined threshold. Current from the capacitor is used to power a pressure sensor which generates a signal associated with a measured pressure. The generated signal, along with identification data of the pressure sensor assembly is transmitted from the pressure sensor assembly to an external device. The external device stores and displays received blood pressure data along with data indicating the activity level of the user.
[0013] Other features of the embodiments herein will be apparent from the drawings, and detailed description that follows below
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 depicts a block diagram illustrating an implantable pressure sensor assembly according to one embodiment of the disclosure;
[0015] FIG. 2 depicts a block diagram illustrating an implantable pressure sensor assembly with an RFID element;
[0016] FIG. 3 depicts a block diagram of an implantable pressure sensor assembly communicating blood pressure and pressure sensor assembly identification data to an external device; and
[0017] FIG. 4 depicts a flow chart of a method of measuring pressure using a pressure sensor assembly.
DESCRIPTION
[0018] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
[0019] FIG. 1 illustrates a general block diagram of a pressure sensor assembly 100 . The pressure sensor assembly 100 includes an accelerometer 102 , a capacitor 104 , a gate element 106 , a pressure sensor 108 , and an RF transmitter 110 . The accelerometer 102 , capacitor 104 , gate element 106 , pressure sensor 108 , and RF transmitter 110 are positioned within a housing 112 . The housing 112 is constructed of biologically compatible material and is hermetically sealed. Accordingly, the pressure sensor assembly 100 can be implanted into an individual.
[0020] The accelerometer 102 is configured to generate an electrical current upon movement of the accelerometer. The accelerometer 102 in one embodiment is a tri-axial accelerometer configured such that changes in movement along any of its three coordinate axes produces electrical current. More specifically, a change in momentum of the accelerometer 102 results in a burst of current. Accordingly, when the pressure sensor assembly 100 is implanted in an individual, or even borne by an individual, changes in momentum of the individual result in generation of electrical current. The electric current produced by the accelerometer 102 is thus substantially proportional to the activity of the individual. To with, as the individual is more active, more bursts of electrical current are produced.
[0021] The electric current produced by the accelerometer 102 is directed to an energy storage device which in this embodiment is capacitor 104 . The bursts of current from the accelerometer thus charge the capacitor 104 . The rate at which the capacitor 104 is charged is directly related to the rate at which electric current is produced by the accelerometer 102 . Accordingly, as an individual's activity increases, the capacitor is charged more quickly.
[0022] The gate element 106 is configured to initially electrically isolate the capacitor 104 from the elements of the pressure sensor assembly 100 other than the accelerometer 102 . When the charge of the capacitor 104 reaches a predetermined threshold, the gate element 106 is configured to discharge the capacitor 104 by electrically connecting the pressure sensor 108 and the transmitter 110 to the capacitor 104 . The gate element 106 in some embodiments is s a diode and in other embodiments is configured to operate a switch to provide discharge of the capacitor 104 .
[0023] The gate element 106 thus discharges the capacitor 104 whenever the capacitor 104 is charged to the threshold voltage. Because the rate at which the capacitor 102 is charged is related to the activity level of the individual, the frequency at which the capacitor 104 is discharged is also related to the activity level of the individual.
[0024] The discharging capacitor 104 provides a periodic current that powers the pressure sensor 108 . The pressure sensor 108 is a low power sensor which, upon energization, generates a signal associated with a sensed pressure. Depending upon the particular configuration of the system, the signal may include data associated with a discrete pressure or data associated with pressure over a short time span. Consequently, the data may include a full cycle of pressure data. A “full cycle” of pressure data means sufficient pressure data to capture the highest value of a cyclical pressure and the lowest value of the cyclical pressure, e.g., one cardiac cycle.
[0025] The signal associated with a sensed pressure is passed to the transmitter 110 which is also powered by the discharging capacitor 104 in this embodiment. The transmitter 110 transmits a signal including the pressure data. In some embodiments a full cycle of pressure data is transmitted. In other embodiments, only an instantaneous pressure data is transmitted.
[0026] In any event, each time the capacitor reaches the threshold voltage, a transmission occurs. Therefore, regardless of the duration of the transmission, the frequency of transmission is related to the activity level. Consequently, even if there is no pressure data, the frequency of transmission provides activity data. Accordingly, some embodiments do not include a pressure sensor and provide only activity data.
[0027] FIG. 2 depicts another embodiment of a pressure sensor assembly. The pressure sensor assembly 150 of FIG. 2 is similar to the pressure sensor 100 and includes an accelerometer 152 , a capacitor 154 , a gate element 156 , a pressure sensor 158 , and an RF transmitter 160 housed within a housing 162 . The pressure sensor assembly 150 further includes an RFID element 164 . The RFID element 164 may be an active or passive element. The RFID element 164 provides a unique identifier to the transmitter 110 which uniquely identifies the pressure sensor assembly 150 . Accordingly, data transmitted by the transmitter 110 is uniquely associated with the individual even if multiple pressure sensor assemblies are transmitting.
[0028] While the above described embodiments include a transmitter which is powered by an internal component, in some embodiments the transmitter is powered by an external device. In such embodiments, a memory (not shown) may be provided. The data generated by the pressure sensor 108 is then stored in the memory along with a time stamp for later transmission. Some of these embodiments utilize a radio frequency identification (RFID) transmitter which is powered by an external device such as an RFID reader.
[0029] As noted above, the pressure sensor assemblies 100 and 150 are configured to transmit pressure data externally. For example, FIG. 3 depicts the pressure sensor assembly 100 wirelessly transmitting data to an external device 200 . The external device 200 includes an RF receiver (not shown). In some embodiments, one or more of a memory for storing received data and a display for displaying the received data is included in the external device 200 .
[0030] The external device 200 in one embodiment is configured to provide feedback to a user. For example, training program goals may be stored in the external device 200 and the feedback may provide details about deviation from the stored goals. In some embodiments, a training program is initially calibrated to the particular individual using interactive sessions. In the interactive session, specific activities are undertaken while the individual's activity level and blood pressure are monitored by the pressure sensor assembly 100 . A baseline is thus established and used to establish training goals for the individual.
[0031] The external device 200 may further be used to monitor, map, and compare the user's data with reference data of a specialist trainer stored on the external device 200 . The device 200 may further be configured to provide a health management report detailing energy burned, weight loss etc. Accordingly, the pressure sensor assembly is useful in a variety of applications where monitoring of an individual is desired.
[0032] Additionally, while FIG. 3 depicts a direct communication link between the pressure sensor assembly 100 and the external device 200 , in some embodiments an intermediate device is used to transmit the data from the pressure sensor assembly 100 to the external device 200 . For example, in embodiments wherein the external device is a server, a cellular phone, PDA, smartphone, or other fixed or mobile device may be configured to receive the data transmitted from the pressure sensor assembly 100 and retransmit the data to the external device 200 . The user may then access the stored data through a network.
[0033] While the embodiments described above are directed to implantable devices, the devices need not be implanted. For example, the device may be configured to be strapped to an individual. Consequently, an individual about to begin an exercise period need only attach the pressure sensor assembly by, for example, positioning a wrist strap with an embedded pressure sensor assembly on the individual's wrist. The individual's activity level and blood pressure can then be monitored during the exercise period. At the completion of the exercise period, the individual simply removes the pressure sensor assembly.
[0034] In some embodiments, the pressure sensor assembly is integrated with a network of sensor devices to provide multiple physiological measurements. Each of the sensors may be provided with an energy harvesting system such as the accelerometer and capacitor of FIG. 1 .
[0035] FIG. 4 depicts a process 210 for measuring activity and pressure of an individual using a pressure sensor assembly as described above. Initially, a pressure sensor assembly 100 is either implanted in an individual or otherwise attached to the individual (block 212 ). As the individual moves with the attached pressure sensor assembly 100 , momentum changes cause the accelerometer 102 to generate bursts of electricity (block 214 ). The bursts of electricity charge the capacitor 104 (block 216 ).
[0036] As the capacitor voltage (V c ) increases, the gate element 106 checks the V c against a threshold voltage (V T ). Such “checking” may be a passive function of the gate element 106 . If the V c is less than the V T (block 218 ), the process returns to block 214 and additional current is generated. If the V c is greater than or equal to the V T , the process continues to block 220 and the gate element 106 automatically discharges the capacitor 104 .
[0037] Upon discharge of the capacitor 220 , the pressure sensor 108 is energized and generates a signal associated with the blood pressure of the individual (block 222 ). The generated signal is passed to the RF transmitter 110 and transmitted to an external device (block 224 ) as transmitted pressure data. In some embodiments, the transmitted signal includes a unique identified for the pressure sensor assembly 100 . The process then continues to block 214 .
[0038] Additionally, the transmitted data is received by an external device 200 , time stamped, and stored (block 226 ). When desired, the stored data is displayed either by the external device 200 or at another user interface operably connected to the external device 200 (block 228 ). The displayed data includes the pressure data obtained from the pressure sensor 108 at block 222 . Additionally, by comparing the time between received data (using the time stamps), activity data is generated and displayed.
[0039] The process 210 may be modified for different embodiments. For example, in embodiments which do not include a pressure sensor 108 , block 222 is omitted. Accordingly, the external device 200 displays only activity data by comparing time stamps of received transmissions.
[0040] In embodiments with an internal memory, the data is time stamped and stored in the pressure sensor assembly 100 after block 222 . The transmission of data (block 224 ) then occurs at a later time.
[0041] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
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In one embodiment, a pressure sensor assembly includes an accelerometer configured to produce a first current upon movement of the accelerometer, a capacitor configured to receive the first current thereby charging the capacitor, a gate element operably connected to the capacitor and configured to discharge a second current from the capacitor upon the capacitor attaining a threshold voltage, a pressure sensor configured to receive the discharged current to produce a first signal corresponding to at least one pressure reading of the pressure sensor, and a transmitter operably connected to the pressure sensor and configured to transmit a second signal based upon the first signal to an external device configured to store data corresponding to the second signal.
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FIELD OF THE INVENTION
This invention relates to a process and an arrangement for the recovery of wastes from polyol production processes.
BACKGROUND OF THE INVENTION
One method for forming polyol involves polymerizing glycol in the presence of a potassium or sodium hydroxide catalyst. Wastes from polyol production via glycol polymerization include polyol, potassium or sodium phosphate and magnesium silicates. Such wastes are considered to be hazardous industrial wastes by the Environmental Protection Agency. Disposing of polyol production wastes is a problem; neither landfilling nor conventional incineration is acceptable. Further, to the extent such waste is disposed of rather than recovered, it represents the loss of potentially valuable products.
There is a need, therefore, for a method to process polyol production wastes which recovers polyol, potassium or sodium phosphate and magnesium silicates as commercially saleable products.
SUMMARY OF THE INVENTION
The aforementioned problems are solved by a novel process and arrangement for separating and recovering polyol production wastes using commercially available processing equipment.
The process according to the present invention comprises first combining the waste, along with excess potassium or sodium phosphate (caustic salt) solution, in an emulsification/de-emulsification reactor to effect a phase separation.
A first stream containing magnesium silicates and some polyol oil and caustic salt solution is withdrawn from the emulsification/de-emulsification reactor and then waterwashed. The water-washed magnesium silicate, along with the caustic salt solution, is fed to a centrifugal dehydrator to remove moisture from the magnesium silicate. Solid magnesium silicate is withdrawn and then desiccated, resulting in commercial grade magnesium silicate.
Caustic salt solution is withdrawn from the centrifugal dehydrator and then vacuum dehydrated to remove moisture. Potassium or sodium phosphate is crystallized via two-stage crystallization and then desiccated to yield anhydrous potassium or sodium phosphate. A portion of the caustic salt solution drawn off the centrifugal dehydrator may be recycled to the emulsion reactor.
A second stream containing polyol oil and some magnesium silicate is withdrawn from the emulsification/de-emulsification reactor and subsequently filtered and dehydrated to yield a commercial grade polyol.
The water that is liberated as the caustic salt solution is dehydrated may be recovered and used as water wash make-up thereby minimizing waste products from the present invention. Further, the risk of combustion and/or explosion is reduced since water, rather than an organic solvent, is used to facilitate separation of the various components of the polyol production waste. Since substantially all of the components from the polyol waste are recovered into commercially saleable products, the process according to the present invention generates substantially no waste products.
The arrangement according to the present invention is a combination of commercially available equipment, as mentioned above, to accomplish the aforementioned process steps.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of the invention will become more apparent from the following detailed description of specific embodiments thereof when read in conjunction with the accompanying drawing wherein:
FIG. 1 shows a flow diagram of the process and arrangement according to the present invention;
FIG. 2 shows an embodiment of a crude crystallizer suitable for use in the present invention; and
FIG. 3 shows an embodiment of a recrystallizer suitable for use in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block flow diagram of a process and an arrangement according to the present invention. The feed 1, which is a mixture of polyol, potassium or sodium phosphate (caustic salt) and silicates, is charged to an emulsification/de-emulsification reactor 3 for separation of these components. The feed is in the form of a filter cake. The filter cake is a damp-sticky-slurry-like material which is most easily fed manually to the reactor. Alternatively, suitable materials handling devices may be used for delivering the feed 1 to the emulsification/de-emulsification reactor.
The polyol will typically have a molecular weight ranging from about 100 to 8000 and a hydroxide number ranging from about 24 to 500. The silicates are typically magnesium silicates.
The feed 1 is mixed with additional caustic salt solution. The additional caustic solution should be about 0.5 to 2 times the weight of the feed 1. The salt concentration of the caustic solution should be such that salt does not drop out of solution in the emulsification reactor 3. A 30 weight percent solution has been found to give satisfactory results. The reactor 3 charge may also include a caustic salt solution recycle stream 19, which is recycled from downstream processing.
The emulsification/de-emulsification reactor 3, like all equipment used in the arrangement according to the invention, is a conventional, commercially available vessel, well known to those skilled in the art. The emulsification/de-emulsification reactor 3 should have means for agitating the reactor contents, such as a variable-speed motor connected to a shaft having blades or paddles, and a means for temperature control such as a steamheating system.
The emulsification/de-emulsification reactor 3 is operated so that the mixture stratifies into three layers or phases. The top layer is composed of polyol, typically containing about 2 to 10 weight percent of water. The middle layer is an aqueous caustic salt solution, typically containing about 1 to 5 weight percent of polyol. The bottom layer is primarily composed of magnesium silicates, typically containing about 1 to 10 weight percent polyol.
To stratify the waste components as described above, the emulsification/de-emulsification reactor 3 should first be operated at low temperature and agitated at high speed to emulsify feed and caustic salt solution. An agitation rate of about 400 rpm for about 30 minutes has been found to be suitable to emulsify the mixture. Temperature should be maintained between about 120° to 205° F. (49° to 96° C.). In a preferred embodiment, the temperature is initially set at about 120° F. and heat is applied during agitation to a maximum reactor temperature of about 205° F. During this step, it is important to avoid boiling the contents of the reactor.
The emulsification/de-emulsification reactor 3 is next operated at lower agitation speeds and higher temperatures to de-emulsify the reactor contents. The temperature should be raised to at least 210° F. (99° C.), and preferably raised to the boiling point of the mixture. Boiling should occur at about 220° F. (104° C.), which varies with the specific composition of the mixture being processed. An agitation rate of about 200 rpm for about 90 minutes has been found to be suitable to de-emulsify the mixture.
Finally, the agitation rate is further reduced and the temperature is decreased to about 200° to 205° F. After about 30 minutes at low agitation and 200° to 205° F., the reactor contents should stratify into three layers as described above. An agitation rate of about 50 rpm has been found to be suitable for this step.
After stratification, the upper-most layer comprising polyol and the lower-most layer comprising magnesium silicates are removed from the emulsification/de-emulsification reactor 3 for further processing. At least two outlets are provided for this purpose. The polyol phase outlet is preferably located on the side of the emulsification/de-emulsification reactor 3 at an appropriate location as a function of the operating liquid level in the reactor 3. A slurry outlet for the magnesium silicates is typically located at the bottom of the reactor 3.
A slurry stream 6 of magnesium silicate solids, some caustic salt solution, and a minor quantity of polyol is fed to a counter-current water wash 8. Make-up water is supplied to the water wash 8 via stream 10. A minimal amount of make-up water is required as moisture recovered in downstream processing of the caustic salt solution can be recycled to the water wash 8. A stream 12 containing water-washed magnesium silicate solids and the caustic salt solution is removed from the water wash 8 and charged to a centrifugal dehydrator 14 where the moisture content of the magnesium silicate solids is reduced and the caustic salt solution and polyol is separated from the magnesium silicate solids. A recycle 16 of dehydrated magnesium silicate to the water wash 8 is established. This may be a manual operation. A dehydrated magnesium silicate product 18, now free of potassium/sodium phosphate contaminants, is fed to a desiccator 20 for final moisture removal. Desiccation yields commercial grade magnesium silicates 22. Typically, the moisture content of the desiccated product 22 is below 0.3% and the organic impurities are less than 0.5%.
Substantially all of the caustic salt solution that was removed from the emulsification/de-emulsification reactor 3 is withdrawn via stream 15 from the centrifugal dehydrator 14. A portion of the flow of stream 15 may be recycled to the emulsification/de-emulsification reactor 3 as the caustic salt solution recycle 19. The balance of stream 15, identified in FIG. 1 as stream 17, is dehydrated in vacuum dehydrator 21. A concentrated caustic salt solution 23 from the vacuum dehydrator 21 is then subjected to two-stage crystallization. In the first stage, concentrated solution 23 is fed to a crude crystallization tank 25. The crude crystalline product 27 is charged to a recrystallizer 29 to yield a finely crystallized potassium/sodium phosphate product 31 having a particle size smaller than 1 millimeter. The finely crystallized product 31 is desiccated in desiccator 33 to yield commercial grade anhydrous potassium/sodium phosphate powder 35.
Where a recycle is employed, stream 17 contains substantially all the potassium or sodium phosphate that enters the process from the filter cake feed 1. Thus, a balance is maintained between the caustic entering and leaving the system. If the present invention is operated without the caustic salt solution recycle 19, substantially all the caustic withdrawn with the magnesium silicates will be recovered as the anhydrous powder 35. Since more caustic may be removed than enters in the filter cake feed 1, additional caustic make-up may be required to maintain the desired amount of excess caustic solution when operating without a caustic recycle 19.
As previously noted, the caustic salt solution typically contains 1 to 5 weight percent polyol. This polyol will contaminate the caustic salt product if not removed. As shown in FIG. 2, a polyol-absorbing material 41, such as a polypropylene fiber cloth, should contact the caustic solution in both the crude crystallization tank 25 and the recrystallizer 29 to remove the polyol. As the moisture content of the solution decreases, polyol will be absorbed by the fiber cloth.
The crystallizers, which may be static-tank crystallizers or other suitable crystallizers known to those skilled in the art, should be modified to prevent the crystallized material from contacting the polyol which is removed. One way to modify the crystallizers is shown in FIGS. 2 and 3, wherein inner tanks and a crystallizer-feed distributor are provided. The crystallizers should be operated in a multi-pass manner for optimum recovery. This may be accomplished by recycling the caustic solution.
FIG. 2 shows an embodiment of the crude crystallizer 25. Concentrated caustic salt solution 23 charged to the crude crystallizer contacts a polyol-absorbing material 41 and is then distributed to the inner tanks 45 via the crude crystallizer-feed distributor 43. A screen 46 is located near the bottom of each inner tank 45. The screen 46 functions as a sieve to retain the material that crystallizes. The screen should be selected to retain material having a particle size greater than about 1 millimeter. The inner tanks 45 are bottomless so that the caustic solution flows out the bottom of the inner tanks. Effluent caustic solution 28 is drained from the crude crystallizer 25 at valve 47. Some of the caustic drained from the crude crystallizer is recycled via recycle pump 48. Recycled caustic 26 is heated by a heating device 49 before it is reintroduced into the crude crystallizer.
FIG. 3 shows an embodiment of the recrystallizer 29. Crude crystalline product 27, effluent caustic solution 28 from the crude crystallizer 25 and recycled caustic 30 are mixed in the crystalline dissolving tank 52. The mixture, as well as fresh water 50, contacts the polyol absorbing material 41 and is then distributed to the inner tanks 45 via the recrystallizer feed distributor 54. The lower portion of each inner tank 45 contains a screen 46 as in the crude crystallizer. As will be appreciated by those skilled in the art, this screen should be sized to retain crystallized material suitable for commercial sale after dessication. Effluent caustic solution 32 is drained from the recrystallizer 29 at valve 47. Some of the effluent caustic is recycled via recycle pump 48. Some recycled caustic 30 is heated by a heating device 49 before re-introduction into the recrystallizer. It should be understood that other modifications for preventing polyol contact with crystallized material will occur to those skilled in the art, which modifications are within the contemplated scope of the present invention.
Stream 5, containing predominately polyol with some moisture, caustic salt and other solid impurities, is removed from the emulsification/de-emulsification reactor 3 and fed to a filtration unit 7 to remove solid impurities including caustic salt. The filtrate 9 flows to a dehydrator 11, such as a vacuum dehydrator, where moisture is removed to yield a commercial grade polyol product 13. The vacuum dehydrator should be operated at about 100 torr and 212° F. The moisture content of the product 13 should be less than about 0.2 percent and the potassium and sodium content below 50 ppm.
Thus, magnesium silicates and polyol are removed from the emulsification/de-emulsification reactor 3, leaving caustic solution. The caustic solution remaining in the reactor is substantially all the additional caustic which was mixed with the feed 1 prior to emulsification/de-emulsification. The caustic solution is suitable for re-use with additional feed 1 as long as the salt concentration is such that the salt remains in solution. If the salt concentration is too high, the caustic solution should be drained from the emulsification/de-emulsification reactor 3 and processed like stream 17 to recover potassium or sodium phosphate powder.
Polyol production wastes were treated by a process and arrangement according to the present invention. The results are shown in Table 1 below.
TABLE 1______________________________________Treatment of Polyol Production Wastes Sample 1 Sample 2 Sample 3 Sample 4______________________________________PolyolMolecular Wt. 400 1000 4800 7000Hydroxyl No. 280 112 35 24Stream Comp., Wt %Polyol 45 40 49 51Potassium Phosphate 13 14 12 12Magnesium Silicates 42 46 39 37Excess KH.sub.2 PO.sub.3 1.25 1.50 1.50 1.80(30% sol.)Excess to FeedConversion Temp. 205 210 214 215(°F.)Polyol Recovery, 97.4 98.1 97.7 99.0wt %______________________________________
The caustic salt recovered from samples 1-4 using the process according to the invention was 99.8 percent pure.
It should be understood that the embodiments described herein are illustrative of the principles of this invention and that modifications may be implemented by those skilled in the art without departing from the scope and spirit of the invention.
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A process and arrangement for separating and recovering polyol production wastes, including polyol, potassium or sodium phosphate and magnesium silicates, is disclosed. According to the invention, the polyol product waste and caustic salt are combined in a vessel, emulsified and then deemulsified. This causes the contents of the vessel to stratify into three layers. A first stream containing primarily magnesium silicates and a minor amount of caustic salt solution is withdrawn from the vessel and then waterwashed. The water-washed magnesium silicates are then dehydrated and desiccated to obtain commercial grade magnesium silicates. The minor amount of caustic salt solution is dehydrated, crystallized and then desiccated to yield commercial grade anhydrous potassium or sodium phosphate. A second stream containing predominantly polyol oil is withdrawn from the vessel and subsequently filtered and dehydrated to obtain commercial grade polyol. The aforementioned process steps can be accomplished by an arrangement of commercially available equipment.
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This application claims priority of U.S. Provisional Patent Application Ser. No. 61/144,177, filed Jan. 13, 2009, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
The preservation of biopharmaceutical materials is essential in the manufacture and storage of these productions. One traditional method used to preserve these pharmaceutical materials is through freezing, also known as cryopreservation.
Biopharmaceutical materials are often frozen and thawed throughout the manufacturing process, as well as afterwards, such as during shipping. Freezing these materials reduces the chances of degradation, microbial contamination and denaturing that can occur at room temperature. For example, cryopreservation allows materials to be partially prepared, and then stored in an intermediate condition, thus decoupling the various activities involved in the manufacture of the product. In order to do so, they are often placed in storage containers, often referred to as biocontainers, ranging in size from a few milliliters to thousands of liters. In some instances, the biocontainers are made from a plastic material with a fixed form. Other biocontainers are more flexible and can take on a multitude of forms. In certain instances, these biocontainers are placed within frames, carriers or other structures that define their shape.
However, in order for cryopreservation to be successful, careful attention must be paid to the operating parameters. It has been reported that the rate at which biopharmaceutical materials are frozen is critical to their continued utility. For example, if the material is frozen too slowly, the diffusion of solutes in liquid bulk is exacerbated, leading to potential issues such as a pH shift, increased ionic strength, and phase separation. In addition, problems such as the formation of small ice crystals within the biopharmaceutical material, e.g., within a protein structure, can stress the material causing, for example, denaturation of the protein. Denaturation is often indicated by unfolding of the protein, thereby causing it to lose its efficacy, and potentially aggregating.
Within a bulk sample, denaturation of material can occur non-uniformly due to non-uniformities in the heat cycles. For instance, a frozen sample exposed to an instantaneous heat source during transport can cause the outer surface to melt. Ideally, a uniform freeze rate across the sample would reduce local denaturation as molecules within the interface layer may experience excessive shear.
To attempt to mitigate several of these issues, custom freezers have been developed, e.g., where the freezer has one or more temperature sensors that are an integral part of the freezer. These integral temperature sensors are either placed inside the biocontainer or positioned such that they abut the biopharmaceutical container, thereby allowing them to record the temperature of the contents of the biocontainer. Based on the measured reading of such a sensor, the freezer adjusts its operating parameters, either attempting to cool more quickly or to maintain the temperature.
While such freezers may be useful in proper cryopreservation, there are many drawbacks. For example, the user is forced to buy a complete system in order to receive the benefits. In addition, the capacity of the freezer may be limited, or the number of temperature sensors may be limited. In other words, while one biocontainer may have a temperature sensor to monitor its temperature profile during the freezing process, other biocontainers within the same freezer may not be properly monitored. This can be problematic as the temperature profile varies within the freezer enclosure. For example, a biocontainer near the door may experience condensation thereby creating different heat conduction pathways. Biocontainers located near the interior walls may freeze more quickly. Furthermore, these freezers only monitor the temperature of the biopharmaceutical material while in the freezer. Any variations in temperature experienced during transit or during the thawing process are not monitored.
Therefore, there exists a need for a low cost, simple solution that enables the user to monitor the temperature profile of each biopharmaceutical container during the cryogenic process, so as to insure the integrity of each biocontainer. Furthermore, a method of monitoring the temperature during the thawing process and during transit would be advantageous.
SUMMARY OF THE INVENTION
The present invention provides a biopharmaceutical container (biocontainer) having an integrated temperature sensor.
The biocontainer of the present invention provides a low cost, simple solution for many of the problems encountered during shipping, freezing and thawing of biopharmaceutical materials. The present invention enables a user to monitor the temperature profile of each biopharmaceutical container during the cryogenic process, so as to ensure the integrity of materials within each biocontainer. In order to meet the requirements of the biopharmaceutical freezing process, the biopharmaceutical container includes a pre-installed and pre-sterilized temperature sensor. Also provided herein are methods of monitoring the temperature during the freezing and thawing process.
In some embodiments, the sensor assembly is positioned within the biocontainer so as to be at or near the thermal center of the material. In certain embodiments, a sensor attachment mechanism, which is attached to one or more points on the biocontainer, is used to hold the sensor assembly in place. Since it is necessary that the interior of the biocontainer be sterile before the introduction of the pharmaceutical material, the sensor components are constructed of materials that can be readily sterilized. In certain embodiments, the temperature sensor is constructed utilizing Silicon on Insulator (SOI) technology, so that it can withstand sterilization, such as gamma sterilization, after it has been inserted into the biocontainer.
The presence of an integrated temperature sensor in the biopharmaceutical container allows numerous functions to be performed. In some embodiments, the sensor assembly includes a wireless transmitter and is capable of transmitting information regarding the measured reading. In other embodiments, the sensor assembly includes a processing unit, which determines whether the temperature profile is acceptable. In a further embodiment, an indicator, such as a visual indicator, is included, such that the processing unit may indicate whether the biopharmaceutical material has been properly frozen. In other embodiments, the sensor assembly also includes a storage element, which is capable of storing various parameters during the freezing process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a first embodiment of an apparatus of the present invention;
FIG. 2 shows the outer surface of the biocontainer of the present invention;
FIG. 3 shows a second embodiment of an apparatus of the present invention;
FIG. 4 shows the internal circuit components according to one embodiment of the present invention;
FIG. 5 shows another embodiment of the present invention;
FIG. 6 shows a flowchart of a freezing process;
FIG. 7 shows a flowchart of a thawing process; and
FIG. 8 shows a flowchart for monitoring the material temperature while in transit.
DETAILED DESCRIPTION OF THE INVENTION
As described above, the need to monitor and insure the temperature profile of a biopharmaceutical material while it undergoes cryopreservation is imperative. Furthermore, it is important to be able to monitor the temperature of a biopharmaceutical material during other steps in the manufacturing and delivery process, such as transit.
In various embodiments according to the present invention, the biopharmaceutical material can be, but is not limited to, an amino acid, a peptide, a protein, a DNA molecule, an RNA molecule, a drug, an enzyme, an antibody or fragment thereof, a tissue or fragment thereof, an organ or fragment thereof, a preservative, a blood product, a cell, a cellular organelle, an inclusion body, and a cellular aggregate. Furthermore, the material may be serum, blood, plasma, an amino acid formulation, a protein formulation, a nucleic acid formulation, and a cell culture media formulation
FIG. 1 shows a first embodiment of an apparatus of the present invention. A biocontainer 100 is used to hold a biopharmaceutical material. This biocontainer is typically constructed of a suitable plastic, such as polyethylene or a laminate material like the Millipore PureFlex™ film. This material is preferable as it is flexible, low cost and able to withstand sterilization, such as gamma irradiation. A sensor assembly 110 is affixed within the biocontainer 100 , such as via a sensor attachment mechanism 120 . In some embodiments, this attachment mechanism 120 is a sleeve that can be sealed, so as to protect the sensor assembly from the biopharmaceutical material. In certain embodiments, the plastic sleeve is sealed after the sensor is installed. In other embodiments, the attachment mechanism is a flexible material with an overcoating or sealable enclosure located at a predetermined location. The sensor assembly is located within this overcoating or sealable enclosure. The attachment mechanism 120 is preferably constructed of materials similar to those used for the biocontainer so as to retain the overall flexibility and usefulness.
The biocontainer 100 , attachment mechanism 120 and sensor assembly 110 may then all be sterilized simultaneously. This sterilization can be of any suitable means, including but not limited to autoclaving, gas sterilization, such as using ETO (ethylene oxide) gas, and gamma sterilization. To allow the sensor assembly to be positioned within the attachment mechanism during sterilization, it is preferable that it be manufactured using a process with a high resistance to gamma radiation, such as Silicon on Insulator (SOI). In other embodiments, traditional semiconductor manufacturing processes are used to produce the sensor assembly, and the assembly is sterilized using autoclaving. Once the biocontainer has been sterilized, it is ready for use.
Regardless of the mechanism used to hold and protect the sensor assembly, the temperature sensor is preferably positioned within the biocontainer such that, when the biocontainer is full or nearly full, the temperature sensor is roughly at the thermal center of the material. This is preferably achieved by locating the temperature sensor at or near the geometric center of a filled biocontainer. The geometric center is determined based on the shape of the filled biocontainer. For example, the geometric center of a rectangular prism is found by connecting opposite diagonals. The intersection of these diagonals is the geometric center. In the case of a cylinder, the geometric center is the center of the circle, located at a position equal to one half of the height. Similarly, those of ordinary skill in the art are able to determine the center of other volumetric shapes.
By being located at the geometric center of the filled biocontainer, the temperature sensor is able to take temperature measurements of the last point within the biocontainer to freeze, as the geometric center of a filled biocontainer is the same location as the thermal center of the material, assuming the density and composition of the biopharmaceutical material is uniform throughout the biocontainer. Of course, if the biocontainer is less than completely filled to its volumetric capacity, the geometric center of the biocontainer may not correspond to the thermal center of the material.
Without wishing to be bound by theory, it is contemplated that even in instances where the biocontainer is not intended to be filled to its full volumetric capacity, one of ordinary skill in the art may incorporate a temperature sensor at or near the thermal center of a predetermined volume of liquid placed inside the biocontainer. For example, a biocontainer may be intended to be filled to less than full volumetric capacity, however, to a predetermined volume. Accordingly, the position at which the temperature sensor is placed inside the biocontainer may be calculated based on the thermal center of a predetermined volumetric capacity of the liquid contained inside the biocontainer, where the thermal center does not necessarily correspond to the geometric center of the biocontainer, but to the thermal center of the predetermined volume of liquid. Accordingly, such a biocontainer can be subsequently provided for use with the specific predetermined volume of liquid. In a further embodiment, a biocontainer including a temperature sensor is provided with instructions for use with a predetermined volume of liquid, where the temperature sensor is positioned at or near the thermal center of the predetermined volume of liquid.
Since placing the sensor at exactly the geometric center of a filled container may be difficult, the present invention also includes placing the sensor near the geometric center. It is obvious to one skilled in the art, that placement close to, but not at, the geometric center will achieve all of the benefits described herein. Thus, the expression “at the geometric center” also includes those locations within proximity such that their thermal behavior is similar to that of the actual geometric center.
Returning to FIG. 1 , the sensor attachment mechanism 120 is shown as extending across the center of a biocontainer. In certain embodiments, exemplified in FIG. 2 , a seam 130 exists along the outer edges of the biocontainer. When the various pieces of plastic are being assembled and fused together, the attachment mechanism 120 is inserted into the seam 130 on opposite sides of the biocontainer 100 . In this way, the attachment mechanism 120 is fused directly to the biocontainer 100 during the biocontainer manufacturing process, thereby minimizing manufacturing steps and handling.
While FIG. 1 shows the attachment mechanism 120 extending horizontally across the biocontainer, the attachment mechanism 120 can be installed in any orientation, as long as it passes through the geometric center of the filled biocontainer. FIG. 3 shows an alternate embodiment, wherein the sensor 110 is held in place via an attachment mechanism 120 that is connected at the upper left corner and lower right corner. Other attachment points are also envisioned and within the scope of the invention.
In another embodiment, a larger piece of plastic is used. This piece is then folded over onto itself, and fused along the open edges. In this embodiment, the attachment points, such as those shown in FIG. 3 , must be located where the open edges are fused together.
As seen in the above Figures, the sensor attachment mechanism 120 includes a physical extension from the sidewalls of the biocontainer to the enclosed electronics. This extension may include a thin film or a plastic strand or string to retain the electronics within the thermal center. In some embodiments, a thermoplastic material of similar construction to that of the biocontainer is used. The shape and size of the extension preferably has a minimal effect on the overall thermal signature of the biocontainer. This is particularly important so as to reduce thermal abnormalities due to conduction along the extension.
FIG. 5 shows another embodiment used to position the sensor assembly 120 in the proper location. In this embodiment, the biocontainer 100 includes ports 150 which are typically attached to the biocontainer 100 using a fusing or welding process. In other words, the ports are attached to the biocontainer 100 over preexisting openings in the biocontainer 100 so that biological material can enter or exit the container. The sensor attachment mechanism 120 can be attached to the biocontainer 100 using these ports 150 . In one embodiment, the sensor attachment mechanism 120 is fused to the port and biocontainer while the port 150 is being affixed to the biocontainer 100 . In another embodiment, the sensor attachment mechanism 120 is affixed via mechanical means to the port 150 . For example, the sensor attachment mechanism 120 may have ends that can be mechanically affixed onto or over the ports 150 . A loop at the end of the sensor attachment mechanism 120 can be used to loop over the external protruding port 150 .
The sensor attachment mechanism 120 is used to position the sensor assembly in the proper location. As described above, in some embodiments, the attachment mechanism contains a protective overcoating or enclosure, such as a plastic enclosure, in which the sensor assembly is located and sealed. This provides a fluid tight barrier between the sensor assembly and the biopharmaceutical material. In other embodiments, a plastic sleeve is used in which the sensor is placed prior to being fused to the other plastic pieces of the biocontainer. Other common methods of isolating electronics from the environment include epoxy coatings or thermal plastic in-molding.
Within the enclosure is a sensor assembly, which includes a temperature sensor, capable of measuring the temperature of the surrounding biopharmaceutical material. To minimize the number of connections, and the potential for contamination and error, the sensor assembly preferably has no wires extending out of the biocontainer. Thus, the sensor assembly preferably operates wirelessly.
A temperature sensor can be employed in a number of ways. In one embodiment, the temperature sensor is unpowered, and simply relays the current temperature measurement when energized by a remote reader, such as a RFID reader. Thus, in one embodiment, the sensor assembly includes at least one temperature sensor, an attached antenna to receive and transmit RFID signals, and the power circuit needed to convert the electromagnetic power from the RFID reader to electrical power to operate the at least one temperature sensor. Also, a remote RFID reader must query the sensor at regular intervals to determine the temperature profile of the biopharmaceutical material during the cryopreservation process.
In another embodiment, a temperature sensor is powered. In certain embodiments, the sensor assembly is powered by a battery contained within the enclosure. The battery is housed such that it is unaffected during the sterilization process. In still other embodiments, the sensor assembly is powered wirelessly, such as via electromagnetic waves or magnetic induction fields. These electromagnetic fields are created by a remote powered antenna. In some embodiments, the remote powered antenna is located within the freezer to maximize energy transfer. In a further embodiment, an unpowered focusing coil is also used to enhance the field near the biocontainer(s). To capture the transmitted electromagnetic waves, the sensor assembly may also contain an antenna. This antenna receives electromagnetic waves, which it then converts to electrical power, which is used to operate the sensor and other electrical components.
In another embodiment, the sensor assembly includes a storage element, such as a memory device. In some embodiments, nonvolatile memory is used, due to its ability to retain data even in the absence of electrical power. The storage element is used to store temperature readings at various times, such as at regular intervals. Later, when the biocontainer is thawed, the operator can interrogate the embedded storage element via a wireless protocol to determine the temperature profile that the biopharmaceutical material underwent. By comparing the stored data to predetermined acceptable limits, the operator can determine whether the material was properly frozen and/or thawed and is therefore acceptable to use.
To perform this query, a variety of wireless protocols including, but not limited to Zigbee, Bluetooth, RFID, Wifi, and 802.11a/b/g/n, may be used.
In another embodiment, shown in FIG. 4 , a processor 200 and a storage element 210 are incorporated in the sensor assembly with the temperature sensor 220 . In addition to storing data as described above, the storage element may contain instructions for the execution of the processor 200 . The incorporation of a processor 200 allows the biocontainer to have increased functionality. In some embodiments, the sensor assembly also contains an indicator 230 , such as a visual indicator, that is used to alert the user as to whether the material was properly frozen. In this embodiment, the processor 200 analyzes the sensor readings in comparison to acceptable limits and determines whether the material was properly frozen and is therefore useable. For example, the measured temperature values may be compared to a reference temperature profile. This reference temperature profile may include a range of acceptable temperatures as a function of time. In another embodiment, the processor 200 may compare the current measured temperature to one or more previous measured temperatures to determine whether the freezing process was properly completed. This determination is then conveyed via the indicator 230 . In one example, a red LED is used to convey failure; in other embodiments, a green LED conveys success.
In another embodiment, this determination of the success of the freezing process is stored in the storage element 210 . In this way, the operator simply queries the storage element 210 to determine the result. In yet another embodiment, a wireless signal is transmitted from a transmitter 240 on the sensor assembly, conveying the status of the freezing process. While the above description discloses several ways in which the results of the freezing process can be conveyed, this list is not intended to be inclusive. Other methods of conveying the results are contemplated and within the scope of the invention.
FIG. 6 shows a flowchart of the steps used to monitor the freezing process of a material. First, as shown in Box 600 , a sterilized biocontainer having a predetermined volumetric capacity is provided. This biocontainer includes a wireless temperature sensor positioned at or about the geometric center of the biocontainer. The biocontainer is then filled with biopharmaceutical material, as shown in Box 601 . The biocontainer is then placed in the freezer as shown in Box 602 .
The temperature sensor is then used to monitor the temperature within the biocontainer as the material freezes, as shown in Box 603 . In some embodiments, the measured temperature values are stored in a storage element, which is in communication with the temperature sensor. In other embodiments, the measured temperature values are transmitted wirelessly by a transmitter in communication with the wireless transmitter.
In other embodiments, a processing unit is in communication with the temperature sensor and performs additional functions. For example, the processor may compare the measured temperature value to a second temperature, as shown in Box 604 . This second temperature may be a previously measured temperature value. In other embodiments, this second temperature is obtained from a reference temperature profile, which is stored in the storage element.
In the event that the comparison indicates that the freezing process is defective, an indicator is actuated, as shown in Box 605 . This indicator may be an alarm, such as an audio or visual alarm. In other embodiments, the indicator may be a data pattern written to the storage element. In other embodiments, the measured temperatures may all be stored in the storage element. These can then be read by the operator at a later time.
This functionality also allows the present invention to serve as a validation tool. In another words, once the biocontainer has been successfully frozen (as determined using one or more of the techniques described above), the operator can be confident that the freezing profile used would be applicable to freeze other biocontainers containing the same material. Thus, one or more such biocontainers can be used to validate a new or modified freezing profile quickly.
In addition to being used to monitor and verify the freezing process, the sensor assembly can also be used to control it. The ability to measure temperature and wirelessly communicate allows the sensor assembly to feedback information to the freezer. In some embodiments, the sensor assembly simply transmits the current temperature of the material. The freezer, using techniques known and described in the prior art, then adjusts its cooling process based on this information. If multiple biocontainers are placed within a single freezer, then the freezer can determine not just the temperature of each biocontainer, but also develop a map of the entire freezer enclosure.
While this sensor assembly is useful during the actual freezing process, it can serve other purposes as well. For example, the sensor assembly may also monitor the temperature profile of the material as it is thawed to ensure that the profile meets acceptable parameters. For example, the thawing process may include a reference temperature profile. This profile may include a range of acceptable temperatures as a function of time. As the material is thawed, the temperature is compared to this reference profile and a determination is made as to whether the thaw process is acceptable. In another embodiment, the thawing process is tracked by measuring the change in the temperature of the material between successive readings. If the deviation of the measured temperature from this second temperature (either the reference temperature or the previous measurement) is too great, an indicator is actuated. The indicator may be an audio or visual alarm, or in other embodiments, may be a data pattern stored in the storage element. In other embodiments, all of the measured temperatures are stored in the storage element. The integrity of the process is then checked at a later time by reviewing the values stored in the storage element. A flowchart of a representative thawing process is shown in FIG. 7 .
Additionally, the sensor assembly can be used to verify the integrity of the material as it is moved in transit to other locations. For example, while in transit, the material may have to remain within predetermined temperature limits. The sensor assembly may continually monitor the temperature of the material to insure that it remains within this range. The actual measured temperature may be compared to a reference temperature or a reference range. The results of this comparison can then be indicated to the user. In one embodiment, the results of the comparison are stored in a storage element in communication with the temperature sensor. In another embodiment, an alarm, such as an audio or visual signal, may be actuated in response to the results of the comparison. In other embodiments, all of the measured temperatures are stored in the storage element. The integrity of the process is then checked at a later time by reviewing the values stored in the storage element.
FIG. 8 shows a flowchart that illustrates the monitoring of biopharmaceutical material in transit. As before, a biocontainer having a temperature sensor located at or near its geometric center is used, as shown in Box 700 . The bag is filled with material, as shown in Box 801 . The temperature sensor than monitors the temperature of the material, as shown in Box 802 . The measured temperature may be compared to a second temperature, as shown in Box 803 . This second temperature may be a previous measured temperature (in case the rate of temperature change is of interest), or may be a reference temperature or range. If the deviation of the measured temperature from this second temperature is too great, an indicator is actuated, as shown in Box 804 . The indicator may be an audio or visual alarm, or in other embodiments, may be a data pattern stored in the storage element.
In another embodiment, a plurality of temperature sensors is used. As described above, the first sensor is located in the geometric or thermal center of the biocontainer. Additional sensors may be located along the outer edges. These sensors are particularly useful in detecting biopharmaceutical material thaw. For example, a sensor located along the upper and lower end of the sensor attachment mechanism in FIG. 3 would allow monitoring of the biocontainer at two opposite locations where premature or unintended thawing may take place.
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The biocontainer of the present invention provides a low cost, simple solution of many of the problems encountered during shipping, freezing and thawing of biopharmaceutical materials. The present invention enables a user to monitor the temperature profile of each biopharmaceutical container during the cryogenic process, so as to ensure the integrity of materials within each biocontainer by using a pre-installed and pre-sterilized temperature sensor. In some embodiments, the sensor assembly includes a wireless transmitter and is capable of transmitting information regarding the measured reading. In other embodiments, the sensor assembly includes a processing unit, which determines whether the temperature profile is acceptable. In a further embodiment, an indicator is included, such that the processing unit may indicate whether the biopharmaceutical material has been properly frozen. In other embodiments, the sensor assembly also includes a storage element, which is capable of storing various parameters during the freezing process.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to the field of headwear and, more particularly, to headwear able to accommodate a range of head sizes, automatically fitting the wearer's head while remaining comfortable for extended use.
2. Description of the Related Art
A baseball style cap generally includes a crown main body, a visor portion that is secured to the forward edge of the crown and extends outwardly therefrom, a headband attached to the lower part of the inside of the crown, and a size controller attached to an underside of the rear of the cap. The size of the cap is adapted to fit the wearer's head using the size controller. This can be inconvenient as the wearer often must adjust the size each time the cap is worn.
To overcome this inconvenience, cap headbands have been constructed that include an elastic band made of fabric which includes spandex yarn, giving the headband size flexibility while eliminating the size controller. It has been found, however, that such a cap exerts pressure against the wearer's head which can become uncomfortable after the cap is worn for an extended period of time. In addition, the size adjustability of such a cap is limited by the lack of elasticity in the thread used to sew the headband and/or the joint between the headband and the crown.
Accordingly, a need exists for a free-size cap having a headband that can accommodate a wider range of head sizes without imposing undue pressure on the wearer so as to remain comfortable over extended time periods.
SUMMARY OF THE INVENTION
In view of the foregoing, one object of the present invention is to provide headwear with a headband that can stretch to accommodate different head sizes without a separate size controlling mechanism.
Another object of the present invention is to provide automatic size-adjusting headwear that does not exert undue pressure on the head when worn.
A further object of the present invention is to provide a cap having wider size range accommodation through the use of nylon stretch thread and rubber thread sewn in a chain-like pattern along the headband.
Yet another object of the present invention is to provide a cap in which the crown part and the headband are joined using rubber thread and nylon thread.
A still further object of the present invention is to provide a headband folded to have a tunnel-like construction at least partially enfolding an insert of spongy material for increased cushioning and moisture absorption.
In accordance with these and other objects, the present invention is directed to headwear having a crown portion and a headband attached to and extending around the lower inside edge of the crown portion. The headband is made of a stretchable material and is folded over an insert of spongy material. A visor part may also be attached to the underside of the crown portion. The sewing thread used on the headband includes rubber thread and nylon stretch thread sewn together in a chain-like pattern to provide expandability and thereby increase the number of different wearer head sizes that may be accommodated by the headband. With this construction, a wide range of automatic size adjustment is obtained without imposing undue elastic pressure on the wearer.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially sectioned view of a baseball-style cap with a headband according to the present invention;
FIG. 2 is a top view of a visor cap with the headband according to the present invention;
FIG. 3 is a top view of another hat, style with the headband according to the present invention;
FIG. 4 is an outer perspective view of the headband having a spongy material insert and sewn with rubber and nylon stretch threads according to the present invention;
FIG. 5 is an inner perspective view of the headband shown in FIG. 4 ;
FIG. 6 is a cross-sectional view of a conventional stitching pattern; and
FIG. 7 is a cross-sectional view of the chain-like stitching pattern according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing preferred embodiments of the invention illustrated in the drawings, it is to be understood that these embodiments are given by way of illustration only. It is not intended that the invention be limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. Also, in describing the preferred embodiments, specific terminology will be resorted to for the sake of clarity. It is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
The present invention is directed to headwear of various types, each having a headband sewn with rubber thread and nylon stretch thread in a chain-like pattern to provide automatic size adjustment to accommodate a wider range of head sizes and with greater comfort than is possible using prior art headwear structures and sewing methods.
According to a first embodiment as illustrated in FIG. 1 , the present invention is directed to a baseball-style cap including a crown main body, generally designated by the reference numeral 1 , a visor portion, generally designated by the reference numeral 2 , and a headband, generally designated by the reference numeral 3 . The crown part 1 is generally made of more than one piece of fabric. The visor portion 2 is secured to the forward edge of the crown main body 1 , and the headband 3 is secured to the lower peripheral edge of the interior of the crown 1 . The visor 2 may include a stiffening member 4 covered with the visor fabric. The headband 3 is folded to have a tunnel-like shape and is secured using a plurality of stitching lines 5 , each of which is composed of rubber thread and nylon stretch thread.
In addition, the joint between the crown main body 1 and the headband 3 (not shown) is sewn using rubber thread and nylon thread, further enhancing the stretchability of the cap. The stitching of such joint may be sewn so as to be visible on the outer surface of the crown main body 1 , or may be sewn so as to be visible only from the inside of the cap such that the consistency of the outer appearance of the cap is not disturbed.
A second embodiment of the headwear in accordance with the present invention, namely that of a visor, is shown in FIG. 2 . The visor includes a crown part, generally designated by the reference numeral 6 , a visor part 2 attached to the front side of the crown part 6 , and a headband, generally designated by the reference numeral 8 . The headband 8 is attached to the lower peripheral edge of the interior of the crown part 6 . The headband 8 is folded to have a tunnel-like shape and is secured using a plurality of stitching lines 9 , each of which is composed of rubber thread and nylon stretch thread. The elastic threads may be readily stretched in the direction of the periphery of the crown part 6 to accommodate various head sizes. As with the cap, the joint between the crown part 6 and the headband 8 is sewn using rubber thread and nylon thread.
A third embodiment of the headwear in accordance with the present invention, namely that of a brimmed hat, is shown in FIG. 3 . The brimmed hat includes a crown part, generally designated by the reference numeral 10 , a brim part, generally designated by the reference numeral 11 , and a headband, generally designated by the reference numeral 12 . The crown part 10 is generally made of more than one piece of fabric. The headband 12 and the brim part 11 are each attached to the lower peripheral edge of the interior of the crown part 10 . The headband 12 is folded to have a tunnel-like shape and is secured using a plurality of stitching lines 13 , each of which is composed of rubber thread and nylon stretch thread. As with the baseball-style cap and the visor, the elastic threads used to stitch the headband of the brimmed hat may be readily stretched in the direction of the periphery of the crown part 10 to accommodate various head sizes, and the joint between the crown part 10 and the headband 12 is sewn using rubber thread and nylon thread.
As shown in each of FIGS. 1-3 , the respective headwear is constructed without a separate size controlling element so that, upon wearing thereof, the fabric of the headband and the stitching thereon are stretched as necessary to fit the wearer's head. The headband may be made of a textile containing no spandex yarn to limit the stretchability of such band or may, alternatively, be made of a textile which includes spandex yarn for increased size adjustability. According to a preferred embodiment, the headband is made of a stretchable material so as to provide expandability in nearly every direction.
FIG. 4 illustrates a headband, generally designated by the reference numeral 14 , according to a preferred embodiment of the present invention. As shown, the headband includes a length of material folded along each longitudinal edge to form a tunnel-like construction. At least partially enfolded within the headband is an insert 22 made of spongy material. The insert 22 provides increased cushioning for the wearer as well as moisture absorbency. While specified herein as a spongy material, other materials having similar cushioning and absorbency characteristics may also be used. When the headband is made of stretchable material, the resulting combination of the headband with insert is very flexible, providing enhanced wearer comfort.
The headband is sewn with rubber thread and nylon stretch thread, visible from the outer side 18 , with “outer” referring to that side of the headband which directly contacts the wearer's head when the headwear bearing the headband is worn. Conversely, FIG. 5 illustrates a view of the inner side 19 of the headband 14 , with “inner” referring to that side of the headband opposite the outer side 18 and contacting the inner surface of the lower edge of the, crown part of the headwear bearing the headband. The headband 14 shown in FIGS. 4 and 5 is representative of each of the headbands 3 , 8 , 12 depicted in the various embodiments of FIGS. 1-3 .
As shown in FIGS. 4 and 5 , the headband 14 preferably includes four lines of stitching, generally designated by the reference numeral 15 . Each line of stitching 15 is formulated using at least two threads, which may be made of different materials, with only one of the threads being visible on one of the sides of the headband. Particularly, as shown in FIG. 4 , the outer portion of the lines of stitching 15 a, namely that portion visible on the outer side 18 of the headband 14 , represents only an outer thread 20 and has an appearance like that of conventional stitching; an example of conventional stitching is shown in FIG. 6 . However, according to the present invention, the inner portion of the lines of stitching 15 b, namely that portion visible on the inner side 19 of the headband 14 , shown in FIG. 5 , includes both the outer thread 20 and an inner thread 21 which, as shown in greater detail in FIG. 7 , are sewn together in a chain-like pattern.
According to the conventional stitching method as shown in FIG. 6 , an upper thread 16 and a lower thread 17 are interwoven in a tongue-and-groove type relationship to each other through the space between the outer fabric 18 and the inner fabric 19 . The resulting lines of stitching look the same on both the outer fabric 18 and inner fabric 19 , with a single one of the threads 16 , 17 being visible on each fabric, respectively.
According to the method of sewing with rubber thread according to the present invention, shown in FIG. 7 , the outer thread 20 and the inner thread 21 are interwoven in a chain-like pattern. Starting at the outer fabric 18 (for purposes of description), the outer thread 20 goes through both the outer fabric 18 and the inner fabric 19 , and then weaves down and up through a double loop of the inner thread 21 , as shown, to form a chain-like pattern on the inner portion 15 b of the lines of stitching. The outer thread 20 then goes back through the inner fabric 19 and the outer fabric 18 to form a generally linear pattern on the outer portion 15 a of the lines of stitching 15 . As shown, only the outer thread passes through the outer and inner fabric layers 18 , 19 of the headband, and the outer thread 20 goes through a double loop of said inner thread 21 in between each pass through such headband fabric layers 18 , 19 .
According to a preferred embodiment, the outer thread 20 is nylon stretch thread and the inner thread 21 is rubber thread. It is also possible to use rubber thread for both the outer thread 20 and the inner thread 21 , or to use nylon stretch thread for both threads, but best results are obtained with the nylon stretch outer thread and the rubber inner thread in accordance with the preferred embodiment.
Through the use of elastic thread elements and the chain-like pattern as described and illustrated herein, particularly in combination with stretchable headband material, the headband according to the present invention achieves good expandability, accommodating a wide range of head sizes with a high degree of comfort for the wearer.
The foregoing descriptions and drawings should be considered as illustrative only of the principles of the invention. The invention may be configured in a variety of shapes and sizes and is not limited by the dimensions of the preferred embodiment. Numerous applications of the present invention will readily occur to those skilled in the art. For example, the headband may be incorporated into hats, caps and visors of other styles. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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Headwear having a crown portion and a headband attached to and extending around the lower inside edge of the crown portion. The headband is preferably made of stretchable material and includes a layer of spongy material. The sewing thread used on the headband includes rubber thread and nylon stretch thread sewn together in a chain-like pattern to provide expandability and thereby increase the number of different wearer head sizes that may be accommodated by the headband. With this construction, a wide range of automatic size adjustment is obtained without imposing undue elastic pressure on the wearer.
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[0001] This application is a continuation of PCT application number PCT/IL99/00616, filed Nov. 21, 1999 and published as WO 01/38656 on May 31, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to methods and devices for releasing additives, such as disinfectants, cleaning agents, colorants, perfumes and the like into the toilet flush water, and in particular to those designed to locate within the cistern or a flush pipe of a toilet.
BACKGROUND OF THE INVENTION
[0003] The application of additives to water flushing toilet bowls serves numerous purposes, such as cleansing, avoiding deposit of sediments, disinfecting, perfuming and even coloring of the water for aesthetic purposes. The application of such additives has long been a problem of interest in the art. An example of the efforts to solve such problems is the use of a soluble solid cake holding the required additives. The cake is immersed in the water stored in the flush water tank or cistern that is conventionally attached to the toilet bowl. The cake gradually dissolves in the water and so the additives reach the toilet bowl with every flush of the water. However, the soluble materials of the cake dissolve at a constant rate, irrespective of the frequency of the flushing of water or the duration of quiescent periods, i.e. the periods between successive flushes. Thus, the dosage of metered amount of solid additives dissolving in the water of the cistern is either impossible or requires awkward solutions. Other attempts in the prior art involve the use of liquid additives. Liquids may be rationed more easily into the water, by their manipulation within chambers, from which they are released, with the aid of means such as siphons, conduits, buoys, valves, dilution chambers and so forth. However, the viscosity of the liquid additives poses a major obstacle. Highly viscous liquids tend to clog water passages and deposit layers that cling to valves and buoys and the like and so obstruct their functioning. Low viscosity of liquids reduces dramatically the possible concentration of the additives and results with inefficient use thereof, as well as requires very large containers for the liquids. No wonder, that the user is seldom given with the capability to adjust his desired amount of additives rationed.
[0004] There is thus a widely recognized need for, and it would be highly advantageous to have an in-tank dispensing device for dosing a toilet liquid additive, free of clogging problems, provides for the use of highly viscous liquid additives and that provides for user adjustable dosage capabilities.
[0005] It is therefore an object of this invention to provide an in-tank dispensing device for dosing a toilet liquid additive without the disadvantages entailed with the prior art.
[0006] Further objects of this invention are to provide an in-tank dispensing device for dosing a toilet liquid additive whereby the device efficiently releases rationed amounts of liquid additives into the water stored in the toilet system in each flushing cycle, irrespective of the duration of quiescent periods between flushing cycles, durable, easy to manufacture, requires mere hanging on the spot by unskilled personnel, adapted to couple to conventional toilet cisterns, allows the use of refillable container or replacement of disposable refills or provides for an entirely disposable device.
[0007] These and other objects will become more apparent when viewed in light of the accompanying drawings and following detailed description.
SUMMARY OF THE INVENTION
[0008] In its broadest aspects the present invention comprises an in-tank passive dispenser for dosing and issuing a predetermined amount of a relatively viscous, moderately soluble, having specific density heavier than water, dispensable liquid, into the cistern tank and the bowl of a flushable toilet as the flush water is draining therefrom with each flush cycle of the toilet.
[0009] The dispenser is capable of varying the amount of dispensable liquid added to the toilet flush water, wherein the dispensable liquid contains additives to the flush water such as a disinfectant, a detergent, a cleaner, a stain inhibitor, a bleach, a dye, a colorant, a fragrance, a perfume, a deodorant or a compatible mixture of two or more thereof.
[0010] The dispenser comprises an inverted container in which a volume of dispensable liquid is stored, the container comprises a downwardly directed discharge spout positioned on the container below the dispensable liquid level within the container and below the water level in the tank during quiescent periods intermediate flush cycles, the dispensable liquid in the container is maintained in an isolated condition from the cistern water surrounding the dispenser regardless of the depth to which the dispenser is immersed in the cistern water by the airlock created.
[0011] The dispenser also features hanger means adapted to suspend the dispenser in the cistern water from an upper portion of the cistern and enabling adjustability of the position or level of the container in the cistern, preferably comprising an elongated portion having at an upper end, means to attach to an upper edge of a cistern side wall, the elongated portion being dimensioned to co-operate with a connection means on the dispenser, in a manner so as to permit the dispenser to be adjustable therealong.
[0012] The hanger means may optionally comprise an elongated flat bar horizontally and removably attached to the inverted container and having a bent down portion at a first end adapted to attach to an upper edge of a cistern wall. The flat bar comprises a groove cut therealong, and the container comprises an upward projecting clasp located a the upper portion of the container, adjacent the cistern wall. The clasp comprises an Elongated portion adapted to be guided along the groove. The elongated portion comprises upper side flanges extending beyond the width of the groove for clinging the flat bar to the top of the container when the elongated portion is inserted in the groove. The the groove comprises a broadened aperture at the second end of the bar, through which aperture the clasp may be removably inserted.
[0013] Further optionally, the hanger means may comprise a curving bar adapted for its affixing to the cistern wall, wherein the bar comprises a central portion curving toward the container, the central portion comprises a vertical slit open at its top and closed at its bottom, the container comprises a clasp projecting toward the cistern wall adjacent the top of the container, the clasp comprises an elongate portion adapted to be guided along the slit, and the elongate portion comprises external side flanges extending beyond the width of the slit for clinging the bar to the container when the elongated portion is inserted in the slit.
[0014] The clasp may be mounted on a depressed section of the container wall for ensuring that the clasp does not protrude beyond the level of the other non-depressed section of the same container wall.
[0015] Preferably, the inverted container comprises a substantially flat wall adapted to facilitate adjacent positioning against the cistern wall when the container is placed in the cistern.
[0016] The dispenser further comprises a basin located below the discharge spout for receiving the predetermined amount of dispensable liquid from the container, the basin comprises basin attaching means for affixing the basin to the container wherein the discharge spout mouth is adjacently disposed above the basin floor, the basin floor is disposed above the water level of the cistern when the cistern is emptied during the flush cycle, upstanding basin side walls extending upwards above the dispensable liquid level of the predetermined amount of dispensable liquid (alternatively referred to as ‘metered amount’), and below the water level in the tank during quiescent periods, so that cistern water fill the basin above the predetermined amount of dispensable liquid during quiescent periods, and a siphon in the form of an inverted U-shaped conduit having a short stand pipe joined by a U shaped bend—extending above the level of the predetermined amount of dispensable liquid in the basin but below the water level during quiescent periods, to a long standpipe, the inlet mouth of the siphon is disposed at the lower end of the short standpipe and being immersed in the predetermined amount of dispensable liquid contained in the basin, and in fluid communication therewith, and the outlet mouth of the siphon is disposed at the lower end of the long standpipe below the bottom of the basin in fluid communication with the cistern water.
[0017] The basin may also comprise discharge control means that provide for a restrained discharge of disposable liquid from the discharge spout, preferably the discharge spout comprises an externally threaded end compatibly receivable by rotary movement relative to, and within an internally threaded upstanding sleeve attached to the basin and encircling the threaded end, the sleeve comprises at least one aperture or cut-out area, the extent of exposure of which is defined by the vertical adjustment of the threaded end within the sleeve, and a surface tension moderator in the form of ribs mounted in the mouth of the discharge spout or in the form of an upright projecting from the basin floor and overlappingly penetrating the mouth of the discharge spout.
[0018] Thus, on intake of flush, water and/or dispensable liquid is siphoned out of the siphon as the cistern flush water drops below the siphon outlet mouth so that the emptied siphon draws dispensable liquid from the basin, a further amount of dispensable liquid enters the basin as air penetrates said container via said discharge spout, until the water level in the cistern rises to its level during quiescent periods. Thus, the cyclic rise and fall of the cistern water results in the controlled discharge-by a siphoning action, of a rationed amount of dispensable liquid from the container.
[0019] Further features and advantages of the invention will be apparent from the description below, given by way of example only.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention will be further understood and appreciated from the following detailed description, taken in conjunction with the following enclosed drawings in which like numerals designate correspondingly analogous elements or sections throughout, and in which:
[0021] [0021]FIG. 1 is a schematic side cross sectional view of one preferable embodiment constructed and operative according to the invention;
[0022] [0022]FIG. 2 is a top view of a dosage basin of the embodiment shown in FIG. 1;
[0023] [0023]FIG. 3 is a bottom view of an attaching means to the toilet cistern wall, of the embodiment shown in FIG. 1;
[0024] [0024]FIG. 4 is a side view of a liquid container of embodiment shown in FIG. 1;
[0025] [0025]FIG. 5 is a cross sectional side view of the dosage basin of FIG. 2;
[0026] [0026]FIG. 6 is a cross sectional top view of a dosage basin of another preferable embodiment constructed and operative according to the invention;
[0027] [0027]FIG. 7 is a cross sectional detailed side view of the embodiment of FIG. 6;
[0028] [0028]FIGS. 8 a and 8 b are top view and side view, respectively, of an enclosure cap of the dosage basin of FIG. 6;
[0029] [0029]FIG. 9 illustrates an optional surface tension moderator that may be used in conjunction with a liquid container constructed and operative in accordance with the invention;
[0030] [0030]FIG. 10 is a side view of a liquid container of a further preferable embodiment constructed and operative according to the invention;
[0031] [0031]FIG. 11 is a top view of the liquid container of FIG. 10;
[0032] [0032]FIG. 12 is a top view of one preferable embodiment of hanger means that may be used in conjunction with the liquid container of FIG. 10;
[0033] [0033]FIG. 13 is a side view of the hanging means of FIG. 12;
[0034] [0034]FIG. 14 is a side view of another preferable embodiment of hanger means that may be used in conjunction with the liquid container of FIG. 10;
[0035] [0035]FIG. 15 is a top view of the hanging means of FIG. 14;
[0036] [0036]FIG. 16 is a partial top view of the liquid container of FIG. 10 assembled with the hanging means of FIG. 14; and
[0037] [0037]FIGS. 17 a - 17 c illustrate, in registration, a side view of a liquid container, a partially cross-sectional side view of a dosage basin, and a top cross-sectional view of the same dosage basin, of a further preferable embodiment constructed and operative according to the invention.
[0038] [0038]FIGS. 18 a - 18 b , 19 a - 19 b depicts different views of portions of the preferred embodiment of the invention, better suited for production, but operating according to similar principles. FIG. 18 a is a top perspective view, and FIG. 18 b is bottom perspective view of a top portion, cooperating with a bottom portion shown in top view in FIG. 19 a and in a cutout side view in FIG. 19 b.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] In general, the present invention is of an in-tank passive dispenser for dosing and issuing a predetermined amount of a dispensable liquid. The term “in-tank” refers to devices that are designed to locate in the cistern tank. By the term “dispensable” reference is made to the dispensing capability of the liquid with the flush water, namely, its being soluble within water, whether as a solution or in an emulsified manner. “Dispensable” also refers to the possibility of refilling the dispenser with fresh supply of liquid, or the disposable nature of the dispenser or a container thereof that holds the liquid.
[0040] The dispensable liquid is preferably relatively viscous—as characterizes a concentrated liquid for adequate effectiveness of a small amount. The dispensable liquid contains additives to the flush water such as a disinfectant, a detergent, a cleaner, a stain inhibitor, a bleach, a dye, a colorant, a fragrance, a perfume, a deodorant or a compatible mixture of two or more thereof. Preferably, the dispensable liquid is only moderately soluble and having a specific density heavier than that of water, for allowing its manipulation in the manner described below. Such requirements are not difficult to meet as most such liquids already inherently acquire the required qualities.
[0041] The dispenser is designed for dosing and issuing a predetermined amount of a dispensable liquid into the cistern tank and the bowl of a flushable toilet as the flush water is draining therefrom with each flush cycle of the toilet. As will be apparent from the following description the dispenser is capable of varying the amount of dispensable liquid added to the toilet flush water.
[0042] Reference is now made to FIGS. 1 to 5 in which a first embodiment of the invention is illustrated, with particular reference to a second embodiment of FIGS. 6 to 8 b , in describing the differences with respect to the first embodiment.
[0043] Dispenser 1 comprises an inverted container 3 in which a volume of dispensable liquid is stored. Container 3 comprises a downwardly directed discharge spout 5 positioned on container 3 below the dispensable liquid level, such as illustrated by level 7 , within container 3 —which may vary from the top to the bottom of container 3 as more liquid is consumed therefrom. Discharge spout 5 must also be located below the water level in the tank during quiescent periods intermediate flush cycles, such as represented by level 9 -which may vary from well over the top to the bottom of container 3 , depending on its position within the cistern. The dispensable liquid in container 3 is maintained in an isolated condition from the cistern water surrounding the dispenser, regardless of the depth to which the dispenser is immersed in the cistern water by the airlock created. As will be appreciated by those skilled in the art, the air above level 7 prevents gravitational flow of the dispensable liquid from container 3 , as long as discharge spout 5 is immersed in water and thus prevents penetration of air into container 3 . Container 3 may be either refillable when emptied, or be disposable and replaceable by a full container—with or without the other parts that form dispenser 1 . Plug 10 is therefore an optional feature that seals container 3 , and is removed prior to the attachment of container 3 to the other parts of dispenser 1 .
[0044] Dispenser 1 further comprises hanger means 11 adapted to suspend dispenser 1 in the cistern water from an upper portion of the cistern and preferably enabling adjusting the position or level of container 3 in the cistern. Hanger means 11 preferably comprises an elongated portion 13 having at an upper end 15 that comprises means to attach to an upper edge of a cistern side wall such as a hook or a bent edge 17 . Elongated portion 13 is dimensioned to co-operate with a connection means on the dispenser, such as open ring 19 in a manner so as to permit dispenser 1 to be adjustable therealong. Such manner may be easily achieved, for example, by a friction tight or a snap-fit engagement between ring 19 and container 3 . An optional broadened portion 21 of container may also serve as a stop means for preventing excessive sliding of container 3 from ring 19 .
[0045] Dispenser 1 also comprises a deck or basin 23 located below discharge spout 5 for receiving a predetermined amount of dispensable liquid from container 3 . Basin 23 comprises basin attaching means for affixing basin 23 to container 3 , wherein discharge spout mouth 25 is adjacently disposed above the basin floor 27 . Basin floor 27 is disposed above the water level of the cistern when the cistern is emptied during the flush cycle. Preferably, discharge spout 5 comprises an externally threaded end 29 compatibly receivable by rotary movement relative to, and within an internally threaded upstanding sleeve 31 attached to basin 23 and encircling threaded end 29 . In order to provide for fine tuning capabilities of the amount of liquid discharged each flush cycle, threaded end 29 and sleeve 31 preferably comprise, in registration, relatively fine threading—allowing fine adjustment of threaded end 29 within sleeve 31 .
[0046] For those skilled in the art wishing to implement the invention, it was found that the following dimensions of discharge spout 5 provide for excellent performance: height—7 mm; internal diameter—8 mm; diameter of its external threaded end—{fraction (7/16)}″.
[0047] Basin 23 further comprises upstanding basin side walls 33 extending upwards above the dispensable liquid level 35 of the predetermined amount of dispensable liquid, and below the water level in the tank during quiescent periods, so that cistern water fill the basin above level 35 of the predetermined amount of dispensable liquid during quiescent periods. Since the dispensable liquid is relatively viscous, moderately soluble, and having specific density heavier than water it will remain as a lower layer in the bottom of basin 23 , with negligible amounts mixing in the surrounding water.
[0048] It will be appreciated by those skilled in the art that as long as discharge spout mouth 25 is immersed in dispensable liquid in basin 35 , and as long as the dispensable liquid in basin 35 can not escape from basin 35 , no further liquid will evacuate from container 3 ; The forces of the water column above level 35 during quiescent periods, the atmospheric pressure above the water and within sealed container 3 (approximately) and the qualities of the dispensable liquid, namely—being relatively viscous, moderately soluble, and having specific density heavier than water, and the relatively narrow passage via discharge spout 25 and the gap to basin 23 , overcome the gravitational force that draws down dispensable liquid from container 3 ; The latter can provide for the drawing only during such time when such counter forces are temporarily nullified, as is achieved by the processes described below.
[0049] Basin 23 further comprises a siphon 37 in the form of an inverted U-shaped conduit having a short stand pipe 39 joined by a U shaped bend 41 extending above metered amount of dispensable liquid level 35 but below the water level 9 during quiescent periods, to a long standpipe 41 . The inlet mouth 45 of siphon 37 is disposed at the lower end of short standpipe 39 and being immersed in the predetermined amount of dispensable liquid contained in the basin floor (below level 35 ) and in fluid communication therewith. The outlet mouth 47 of siphon 37 is disposed at the lower end of long standpipe 43 below the bottom 27 of basin 23 in fluid communication with the cistern water. The affixing of siphon 37 to basin 23 may be achieved by means such as clasp 44 . On intake of flush, the cistern empties rapidly, and water and/or dispensable liquid that is within siphon 37 is siphoned out of the siphon as the cistern flush water drops below the siphon outlet mouth. Thence, the pressure within emptied siphon 37 drops dramatically and thus siphon 37 draws dispensable liquid from basin 23 , in the amount predetermined according to the structure and size of siphon 37 or the amount present in basin 23 , as well as the small amount of water still in the basin 23 . Once the basin is emptied, air can freely penetrated into container 3 via discharge spout 5 and further dispensable liquid will flow into basin 23 , until the flush cycle is over and the water level therein rises again to flood basin 23 . It will be appreciated that the cyclic rise and fall of the cistern water thus results in the controlled discharge—by a siphoning action, of a rationed amount of dispensable liquid from container 3 .
[0050] Preferably, basin 23 further comprises discharge control means that provide for a restrained discharge of disposable liquid from discharge spout 5 . Such control means preferably may use an externally threaded end 29 of discharge spout 5 that is compatibly receivable by rotary movement relative to, and within an internally threaded upstanding sleeve 31 that is attached to basin 23 and encircles threaded end 29 , as already explained above. Sleeve 31 preferably comprises at least one aperture or cut-out area 49 , the extent of exposure of which is defined by the vertical adjustment of threaded end 29 within sleeve 31 .
[0051] Due to excessive viscosity the smooth streaming of dispensable liquid through discharge spout 5 and area 49 may be hampered. An optional surface tension moderator in the form of an upright 51 that projects from basin floor 27 and overlappingly penetrates the mouth 25 of discharge spout 5 can relieve such hindrance.
[0052] Another example of surface tension moderator may be in the form of ribs mounted on the mouth of discharge spout 5 , such as ribs 53 illustrated in FIG. 9. Ribs 53 preferably comprise upper sharp edges 55 for facing the dispensable liquid when incoming from container 3 . Sharp edges enhance the tension moderating character of the ribs. Ribs 53 may be in the form of a cross shaped moderator, as in FIG. 9, but it will be appreciated that many variations of such form may be well suited for this function.
[0053] Referring now to FIGS. 6 to 8 b , another embodiment of the present invention is shown. This embodiment is a compact, easy to manufacture, variation of the embodiment of FIGS. 1 to 5 . Discharge spout 5 is inserted in a similar manner into ring 131 that features an opening 149 through which dispensable liquid flows on basin floor 127 of basin 123 . Basin 123 comprises two conduits—a short conduit 139 with a closed bottom, and a long conduit 143 extending through basin floor 127 and having its outlet mouth 147 below basin floor 127 . Conduits 139 and 143 may be drilled in a solid portion of basin 123 for ease of manufacture. An upper passage 141 connects the upper portions of conduits 139 and 143 . A passage 155 connects the inner hollow parts of basin 123 to conduit 139 . An enclosure and sealing element 157 completes the structure of basin 123 . Element 157 has an L-shaped cross-section and comprises a roofing portion 159 and a side potion 161 . Portion 159 conceals, in a substantially water tight manner the upper portion of chunk 153 and thus forms an upper roof to passages 141 and 155 , and conduits 139 and 143 . Portion 161 partially covers passage 155 , but its main function is to hold portion 159 in place. Element 157 is disposed in place by inserting portion 161 through guiding rails 163 that are carved on walls 133 between chunk 153 and projections 165 .
[0054] Reference is now made to FIGS. 10 to 16 in which further alternate embodiments of container 3 and hanger means are presented. Hanger means in FIGS. 10 - 13 comprise an elongated flat bar 201 removably horizontally attachable to inverted container 3 and having a downward bent portion 203 at its first end 205 , adapted to attach to an upper edge 207 of a cistern wall. Flat bar 201 comprises a groove 209 cut therealong. Container 3 comprises a clasp 211 projecting upwards on the top portion of the container, adjacent the cistern wall 207 . Clasp 211 comprises an elongate portion 213 adapted to be guided along groove 209 . Elongated portion 213 comprises upper side flanges 215 extending beyond the width of groove 209 for clinging flat bar 201 to the top of container 3 when elongated portion 213 is inserted in groove 209 . Groove 209 comprises a broadened aperture 217 at the second end 219 of bar 201 , through which aperture 217 clasp 211 may be removably inserted. Bar 201 may be adjusted along elongated portion 213 in a friction tight manner to firmly grip cistern wall 207 , and released whenever removal of container 3 is desired.
[0055] A further alternate embodiment of hanger means 11 is shown in FIGS. 10 to 11 and 14 to 16 . Hanger means 11 further comprise a curving bar 221 adapted to be fixed to cistern wall 207 , by any known manner, such as by the permanent bonding, riveting or fastening of lateral ears 222 to the cistern wall 207 . Bar 221 comprises a central portion 223 curving toward container 3 , and central portion 223 comprises a vertical slit 225 open at the top 227 and closed at the bottom 229 . Container 3 comprises a clasp 231 projecting toward cistern wall 207 adjacent the top of container 3 . Clasp 231 comprises an elongated portion 233 adapted to be guided along slit 225 . Elongated Portion 233 comprises external side flanges 227 extending beyond the width of slit 225 in curving bar 221 to support container 3 when elongated portion 233 is inserted in slit 225 .
[0056] Preferably, clasps 211 or 231 are mounted on a depressed section 235 or 237 , correspondingly, of the wall of container 3 to ensure that clasp 211 or 231 does not protrude beyond the level of the other non-depressed section 239 or 241 , correspondingly, of the same wall of container 3 . Such configuration ensures that clasps 211 and 231 do not interfere with the contiguous attachment of container 3 to cistern wall 207 or its juxtaposing to upper cover of the cistern (not shown). Container 3 further preferably comprises a substantially flat wall 241 adapted to be contiguously positioned against cistern wall 207 when container 3 is placed the cistern, to eliminate movement and to stabilize container 3 while the cistern water turmoil.
[0057] In reference to FIGS. 17 a to 17 c , a further embodiment of the present invention is shown. This embodiment is a further variation of the embodiment of FIGS. 1 to 5 and is particularly similar to that shown in FIGS. 6 to 8 b . The main difference being in the addition of an intermediate conduit, such as a flexible plastic pipe 301 , between liquid container 3 and basin 323 . The addition of pipe 301 allows the mounting of liquid container 3 remotely from basin 323 . The separation between container 3 and basin 323 provides, among others, for positioning container 3 outside the cistern. This configuration saves the need to hang dispenser 1 in its entirety within the cistern. Some flushing tanks may pose a difficulty for the insertion, placing or hanging of container 3 there within. This is the case when there is lack of sufficient clearance from the flushing mechanism inside the tank or when opening and closing of the tank-cover is inconvenient. Moreover, basin 323 may be made small enough to permit installation in the flushing conduits rather than in the tank itself. In such a case the specific weight or density of the dispensing liquid need not be heavier than that of water.
[0058] Discharge spout 5 is inserted in a similar manner into adapter ring 310 that features an extended conduit 311 that can be water-tightly inserted into the end of pipe 301 .
[0059] The other end of pipe 301 is similarly tightened to an extended conduit 335 of ring 330 that is in fluid communication with opening 349 , through which dispensable liquid flows on basin floor 327 . Ring 330 may preferably feature adjusting capabilities allowing adjustment of its height above basin floor 327 . Such capabilities allow calibrating the degree of exposure of opening 349 , thence regulating the rate of flow and eventually the amount of dispensable liquid released therefrom with each flush cycle.
[0060] For example, extended conduit 335 may comprise an externally threaded portion 329 compatibly receivable by rotary movement relative to, and within an internally threaded ring 330 encircling threaded portion 329 . In order to provide for fine tuning capabilities of the amount of liquid discharged each flush cycle, threaded end 29 and sleeve 31 preferably comprise, in registration, relatively fine threading allowing fine adjustment of threaded end 329 within ring 31 . An alternate flow calibration control may be provided by an externally threaded end 329 ′ of conduit 335 that is compatibly receivable by rotary movement relative to and within an internally threaded upstanding apertured sleeve 331 . Sleeve 331 is attached to basin 23 and encircles threaded end 329 ′, save its cut out aperture 349 . The operation of such structure is corresponding to what has been explained above.
[0061] Basin 323 comprises two conduits—a short conduit 339 with a closed bottom, and a long conduit 343 extending through basin floor 127 and having its outlet mouth 147 below basin floor 327 . Conduits 339 and 343 may be drilled in a solid portion of basin 323 for ease of manufacture. An upper passage 341 connects the upper portions of conduits 339 and 343 . A passage 363 connects the inner hollow parts of basin 323 to conduit 339 . An enclosure and sealing element 357 completes the structure of basin 323 . Element 357 has an L-shaped cross-section and comprises a roofing portion 359 and a side potion 361 . Portion 359 conceals, and substantially makes watertight, the upper side of passages 341 , and conduits 339 and 343 . Portion 361 partially covers passage 363 but its main finction is to hold portion 359 intact in place. Element 357 is held in place by inserting portion 361 through guiding rails 363 that are carved on walls 333 .
[0062] While the invention has been described with respect to specific embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.
[0063] With the foregoing description, it is believed apparent that the present invention enables the attainment of the objects initially set forth herein.
[0064] It should be understood, however, that the invention is not intended to be limited to the specifics of the illustrated embodiment, but rather is defined by the accompanying claims.
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A dispenser for dispensing metered amount of liquid into a toilet cistern, comprising a basin adapted to receive a metered amount of dispensable liquid received from a container via a discharge spout. An airlock prevents further discharge of a liquid above a predetermined amount in the basin when the discharge spout is covered vy the dispensable liquid. A siphon inlet is in liquid communication with the metered amount in the basin, and the siphon outlet is in liquid communications with the cistern water at quiescent times. Upon flush, the siphon siphons out the dispensable liquid in the basin, breaking the airlock, and allowing a new metered amount of dispensable liquid to flow to the basin, ready for the next flush.
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FIELD OF THE INVENTION
This invention relates generally to optical storage products (and other optical devices such as holographic and binary diffractive elements). More particularly this invention relates to optical storage products where diffractive or refractive features on the order of a few microns or less are embossed on the surface of a substrate and coatings may be applied to these devices by vacuum evaporation, sputter, vapor deposition or other vacuum coating techniques.
BACKGROUND OF THE INVENTION
The widespread adoption of optical storage products such as the "Compact Disc" (CD) has made it desirable to manufacture these products by processes which have the potential to greatly increase throughput and decrease cost. Optical storage products made by such a process could greatly increase the dissemination of information while reducing the need for paper production with its negative environmental impact and improving the accessibility and archivability of the information.
Continuous processes most notably roll to roll are known to be more effective in making large volumes of products at low cost. The well known "floppy" magnetic disks are one good example of this. In fact rolls of the disk material structures are commonly sold as product in the "floppy industry." However optical disks and other elements are almost exclusively made by discrete batch injection molding based processes. As a consequence of this history several attempts have been made to manufacture optical media in continuous processes. The article "Continuous manufacturing of thin cover sheet optical media" by Slafer et. al. (including the present inventor) in the Proceedings of the SPIE (Vol. 1663 pg. 324) describes one approach. U.S. Pat. No. 4,831,244 ('244) discloses optical card structures with disk patterns made using the approach of this publication. The book, "Optical Recording--a Technical Overview, by Alan B. Marchant, published by Addison-Wesley Publishing Co. 1990 presents a good view of prior art techniques, especially the section on Mastering, page 327. The article in the Proceedings of the SPIE and the book are both hereby incorporated by reference herein as if laid out in full text. In the SPIE article a continuous roll embossing process is used to create optical features on the surface of a substrate which is then coated with appropriate absorptive, active, reflective and or refractive layers to produce functional optical media or elements. Land in U.S. Pat. No. 4,366,235 ('235) describes the general outline of the process of embossing a roll of substrate with appropriate optical features using an embossing drum and fluid. These process steps are characterized as "known in the art". A similar approach is described by Beaujean in U.S. Pat. No. 4,543,225 (225). Another similar approach by Foster U.S. Pat. No. 4,836,874 ('874) uses roll embossing with a fluid that has a dye included for improving the feature forming by absorbing laser light. All of these approaches are characterized by one or more of the following elements: lamination of a thin web to a cover sheet, embossing by a fluid, manufacture of a special embossing drum, and separate processing steps.
The past attempts to manufacture optical media and components in a continuous process have shared the characteristic that they have not been truly continuous but rather have been segmented and in many cases multiple substrate processes. In the case of the above cited U.S. Pat. Nos. '244, '225, and '874, two substrate webs are used and a chemical fluid based embossing process is employed. This requires that the vacuum coating of recording and or reflective layers be done in a separate segmented step.
Another problem associated with a chemical embossing process is the drum used to effect the embossing. If the drum does not have a seamless surface, fluids can accumulate in and flow out of the seams onto the substrate thus destroying the fine structure tolerance features which are necessary for optical grade devices and media. Seamless drums are difficult to fabricate, time consuming, and consequently expensive especially in wide web systems. One would like to use discrete embossing tools individually mounted on a drum as they are easy to manufacture using existing optical mastering and electroforming technology, they allow mounting across web as a means to work with wide webs, and as is disclosed later they can be compensated for distortions resulting from wrapping them on a drums' surface. Also discrete embossing tools can be easily changed for short run, quick turn around situations. An additional problem with earlier processes is the need for an high cleanliness environment laminating step in order to provide a low defect bond line between the thin web which is vacuum coated and the thick web optical cover sheet that provides isolation from surface defects and makes the structure sufficiently rigid and flat.
In an attempt to avoid the consequences of the earlier fluid based embossing U.S. Pat. Nos. 5,423,671, 5,368,789, 5,281,371, 5147,592, and 5,075,060 combine embossing into the process of extruding or molding of a thick substrate. Unfortunately this approach has similar problems to the earlier efforts when it comes to the need for a seamless embossing tool, as now the tool is part of the extrusion process. To achieve proper gauge thickness and tolerance along with avoiding "flashing" into the seams of a drum with discrete tools mounted on its surface is very difficult. As the gauge thickness appropriate to higher numerical aperture optics systems decreases, these problems will magnify. This will compromise the speed of the extrusion process, the bulk material birefringence, and its cost. Most important this approach makes it very difficult to integrate the embossing step into a single continuous vacuum machine as extrusion is combined with embossing. A consequence of this unintegrated process architecture is that the most critical surface in the structure the embossing is vulnerable to damage via handling before the vacuum coatings and protective layers can be added to complete the manufactured structure.
Generally speaking it is essential to avoid the use of fluids or liquids in embossing and to separate the extrusion of the substrate from the embossing step. This eliminates as much as possible the potential for outgassing and other vacuum compromising effects and allows extrusions to be made off line at maximal widths and web speeds. Also it is mandatory that only micron dimensional volumes of material be activated and or enabled to participate in the embossing step thus eliminating the potential for structural compromise like dimensional changes, stress, birefringence, and other distortion producing effects and material movement into interstitial boundaries between discrete embossing tools. These principles are the basis for developing a machine architecture which combines all process steps into one machine, uses a single substrate, and employs individual embossing tools so quick turnaround with high volume is realizable. It is important to emphasize that the novel object of this invention is to create a process architecture compatible with the environment in a vacuum coating chamber not that a vacuum be used to make the embossing. Bussey et. al. in U.S. Pat. No. 3,957,414 disclose the use of a vacuum between a substrate and an embossing "screen", but it is evident that this approach would not work in a vacuum chamber where there would be no gas to apply pressure to the substrate.
Another problem inherent with drum embossing is the distortion due to the curved contour of a drum. While is easy to master rectilinear features directly on a drum tool as would be the case for tape or card stripes, the use of a standard disk mastering recorder is essential to making precision circular tracks as found on disks. This however requires the tools (stampers) to be wrapped around a drum circumference and results in the distortion of the circular track patterns. When a planar tool of finite thickness is wrapped on a drum, patterns on the outside surface are elongated and patterns on the inside are shortened in the circumferential direction. Thus circles become prolate ellipse like patterns on the outside of tools wrapped on a drum. In the case where a substrate is wrapped around the tool and then returned to a flat geometry, the same effect occurs but patterns on the inside are elongated and so the problem is compounded. One solution to this problem is to precompensate for this effect using the mastering machine to record oblate rather than circular track patterns, but this approach has problems and limitations if the substrate is thick (0.1 mm or greater) as will be the case for single substrate disk or card manufacturing processes as contemplated in the preferred continuous single machine.
It is an object of the present invention to provide a method and a single integrated apparatus, which in a single pass continuously embosses and coats a continuous substrate.
It is another object of the present invention to provide a system without using any liquids, or molten/fluid state materials.
It is yet another object of the present invention to provide a conditioning of a substrate immediately prior to embossing, wherein the conditioning prepares the substrate and stamper for impressing the embossing pattern.
Yet another object of the present invention is to provide an embossing process that is compatible with the coating environment, such that the embossing and coating can be accomplished in the same environment.
Another object of the present invention is to provide uninterrupted process starting with a roll of substrate and ending with a roll of finished embossed and coated structures ready for cutting from the web.
Still another object of the present invention is provide a process and apparatus that is compatible with discrete embossing tools as this gives greater flexibility, quicker turnaround with higher volumes and lower cost to the process.
It is still another object of the present invention to provide a single environment wherein the entire embossing and coating is accomplished.
It is still another object of the present invention to compensate for embossing distortion found when embossing using stamper tools with a finite thickness are mounted on drums. A related object is to provide such compensation for distortion effects on a single thick substrate.
SUMMARY OF THE INVENTION
The above objects are met with a single machine continuous system where the embossing step is integrated with the requisite environmental (vacuum in a preferred embodiment) chamber coating steps in a single pass process. This results in a continuous uninterrupted process and system wherein a roll or sheet of substrate is embossed and coated.
Due to the large base of materials science and production capability in this field, in a preferred embodiment, it is advantageous to work with the existing molding materials as much as is practical. Three of the more common methods and materials of molding are: 1) thermoforming of polymers (e.g. polycarbonate), 2) cross linking of resists (photo-chemical materials), and 3) curing of thermosetting resins. However, as mentioned above these molding methods normally utilize polymers in fluid or molten states to form optical disk or element substrates that are incompatible with use in a vacuum.
The present invention uses no liquids, and in a preferred embodiment advantageously uses directed energy beams to assist in the creation of "micro molds" by conditioning the surface of a substrate just prior to embossing in a continuous manner. Directed energy beams of electrons, ions, nuclear particles, photons, etc. have a unique ability to concentrate depth dose profiles of ionizing or direct thermal excitation radiation in shallow profile surface volumes of materials. These beams can and often must be generated and propagated in vacuum environments, which is the environment used for coating (vacuum evaporation or sputtering and the like) the embossed substrates. The use of electrostatic, electromagnetic, refractive, reflective, and other techniques for shaping beams and/or scanning them are well known and powerful tools for directing energy deposition in timely and efficient ways. The embossing assist technique herewith disclosed is the use of directed energy beams concentrated in or near a nip created between a substrate and an embossing tool by virtue of a pressure roll and a mounting drum. This assist to conventional thermal and pressure embossing creates an effective mold in said nip region whose volume and temporal duration are sufficiently constrained so that an impression on the surface of the embossing tool can be transferred to the substrate surface and retained with requisite fidelity and speed to make optical media and similar elements in high volumes with low labor, overhead, and other costs. The substrates can be solid embossable plastics such as extruded polycarbonate or carrier mechanical webs (e.g. polyester) coated with appropriate embossable layers.
The above described distortion problem and limitation of the prior art processing using a drum for embossing is relieved in the present inventive approach which uses the deformation process itself (or in conjunction with mastering) to compensate for the distortion. With reference to FIG. 2, the second generation tool ("mother"--M) which is used to make the final tool(s) (stamper) is made with a conventional electroforming cell. It is mounted on an electrode E1 in an electroforming cell with a significantly smaller radius R1 than the radius of curvature R2 of the embossing drum. The stamper plated in the curved cell will be formed with a somewhat oblate pattern on the outside of a curved surface by virtue of the curvature of the mother and/or some precompensation. When the stamper is somewhat flattened onto the more modest radius of curvature R2 of the embossing drum, it will deform to produce a more oblate pattern. This pattern when transferred to a substrate which is subsequently flattened will result in a circular track pattern. This approach requires the embossing process to be compatible with individual tools obtained by this compensation method.
In a preferred embodiment of the present invention, a single machine provides continuous manufacture on a web (roll, sheet, as defined herein) substrate of optical media and/or optical component elements. The economic impact of this is to make the manufacturing costs distinctly lower especially for complex structures (e.g. phase change and other multi layer vacuum coated recordable media). This is because the cycle time per unit can be significantly shorter i.e. fractions of a second rather than seconds, and the use of a single machine reduces the handling and set up time of using several machines and processes. Moreover, the reduced handling decreases the breakage and the rejection rates. This means that depreciation, labor and other costs are absorbed over many more units. Also of even greater economic impact is the potential for quick turnaround very high volume production from a single machine making possible the distribution of time sensitive matter like that found in magazines and newspapers. An additional advantage of the present invention is the ability to produce optical media and elements simultaneously in the same web (e.g. ROM and holographic optical elements), thus the value of such a structure output from the inventive process is significantly enhanced.
Other objects, features and advantages will be apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross sectional diagram of an embossing machine/station showing the principal elements combined in a vacuum chamber with vacuum coating stations and indicating a connecting pathway to contiguous chambers which may contain other coating stations as well as roll take up or sheeting components of the disclosed continuous single machine architecture.
FIG. 2 is a diagram of the embossing tool distortion correction process. It shows electroforming of a stamper in a curved electroforming cell and then partial flattening on an embossing drum to produce a compensating correction to distortions in the surface relief patterns of the embossing tool and the embossed substrate.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1. shows a diagram of one possible configuration of the embossing machine/station. A drum 1 and pressure roll(s) 2, 3 confine a web (roll or sheet) substrate material 4 to produce a nip 11 with an embossing tool which is clamped or bonded to the drum at its leading edge 5 as is the case for multiple other individual tools 6. Herein "web" is defined as the bulk forms of substrates as delivered form manufacturers, including but not limited to sheets, rolls, tapes, and the like. Directed energy is concentrated into the nip area from source position A for beam quanta which are directly absorbed by the substrate or alternatively from source position B for those quanta which can penetrate the substrate and deposit energy at the opposite surface either by virtue of the quanta energy chosen and/or surface treatment of the substrate. The energy is directed into the substrate and the embossing tool surfaces in proportions which are dictated by the nature of the polymer molding mechanism which is employed (i.e. thermoforming, cross linking, or thermosetting). The entire machine is contained in a vacuum pumped chamber 7 which can hold a vacuum similar to that used for typical vacuum coating purposes as diagrammed by the coating heads 8. Enhancement of the surface of the substrate, prior to embossing, can be accomplished by vacuum metalization, ion implanting, dye/polymer coatings, and/or other treatments can be done for example by the coater head(s) 9. Also, the surface of the stamper tools can be cleaned, preheated, coated or otherwise conditioned by directing energy from plasma ion infrared photon, and other sources at locations 10. This chamber can be a single large vessel containing all process steps or a compartmentalized structure if isolation of the process steps produces better conditions due to differential pumping, baffling or similar krnown vacuum system designs. It should be noted that pressure roll 3 is optional and not necessary if wrapping the substrate on the drum can be avoided as is desirable since this produces less pattern distortion.
In a preferred embodiment the polymer molding mechanism is thermoforming and the directed energy is infrared photons or electrons, both of which can produce depth dose profiles of a few microns. They can be supplied from high current filament sources or lasers. Examples include a linear resistive filament with a parabolic reflector, an electron gun similar to that used in a cathode ray tube or X-ray tube, a CO2 laser, etc. The beam can be directed into the nip vicinity by a variety of known techniques such as reflector collimators, electrostatic optics, cylindrical refractive elements, and a variety of other known art elements. Scanning by electric fields in the case of electrons or for photons: acousto-optic deflectors, polygons, or galvanometers can also be used so long as the scan rate is sufficient to assure continuous uniform depth dosing of the active mold volume. A small Gaussian scanning spot has the advantage that it can be monitored, shaped and guided easily. From the standpoint of simplicity, a linear extended spot stretching across the nip is desirable and can be formed with simple optical techniques in the case of photons.
Various enhancements to this embodiment may be employed. For example the surface of the substrate may be textured during extrusion to improve absorption and reflection characteristics. In addition co-extrusion or coating of an absorption enhancing layer may be done in line with the substrate extrusion or in the embossing chamber at location 9 in FIG. 1 using vacuum techniques. Thin layers of ion implanted, metal evaporated, or polymer vapor vacuum coatings are particularly useful especially in conjunction with texturing. The surface of the embossing tools can also be coated or otherwise treated at location 10 to optimize the absorption to reflection ratio for the particular beam quanta chosen. In the case of media where the recording/reading is not done through the substrate (e.g. tape or near field disks) a reflector layer on the surface of a mechanical carrier web with a thin embossable coating on top will produce a high depth dose concentration in the coating layer.
Another embodiment of directed energy embossing using thermoforming is with the beam directed through the substrate as from position B in FIG. 1 (or alternatively the back side of the nip roller 2). In this case the beam quanta must be capable of penetrating the substrate and depositing energy at the surface adjacent to the embossing tool and/or the tool surface. It is well known that charged particles have ranges in materials characterized by a relationship to their energy and that a substantial portion of the energy is deposited at the end of range for the case of ions so they are a natural candidate for this approach. Also near infrared and visible photons can pass through substrates and interact with the surface of the embossing tools or with enhancing surface layers on the substrate as described above.
It is important to note that grazing incidence is of significant importance in coupling the directed energy into the surfaces of the substrate and tool and that the disclosed source positions are essential in providing said angle of incidence. Small angle incidence reduces the depth dose into the substrate by about the sine of the angle. If photons are used and the direction is through the substrate at the "critical" angle, total internal reflection will result and coupling to the surface will be very good. Also with the disclosed direction of beam energy it is possible to apportion the dose between the substrate surface and the tool. Small angle incidence will result in forward scattering off the tool and substrate thus propagating more energy deep into the nip. In addition the use of two sources one at each of the disclosed positions is readily achievable. For example a CO2 laser could be used in position A and a near IR resistive filament/parabolic reflector source can be positioned at B. A third source option would be resistive electrical heating of the stampers at this point. Also with IR/parabolic reflector or plasma ion sources mounted around the circumference 10 of FIG. 1 and directed at the tools on the drum, it is possible to controllably modulate the temperature of the tools so that they are near the Vicat or thermoplastic softening temperature on entrance to the nip where they can transfer energy via conductive and radiant processes. After passing the nip roller they can be rapidly cooled through appropriate choice of the insulators mounted between the drum and tool backside. This will aid the embossing process by reducing the required directed energy in the nip and limiting the temperature cycle shock the tools experience.
Generally, in preferred embodiments, the depth dose required is 0.9 microns or less and the quanta ranges of interest are on the order of microns so the grazing incidence angle of optimal effect is in the neighborhood of 10 to 20 degrees.
As previously stated another embodiment of the disclosed embossing technique works with thermosetting resins (e.g. epoxies) which are 100% solids materials with viscous or thixatropic flow character and can be coated on a substrate in vacuum by known processes like gravure and slot head coating. The above described techniques for effecting embossing in thermoforming plastics will also work with thermosetting resins.
Yet another embodiment employs the ionizing nature of certain directed energy beams such as charged particle and UV photons to crosslink or polymerize monomer and copolymer precursors. Yializis in U.S. Pat. No. 4,954,371, Shaw et. al. in U.S. Pat. No. 5,725,909 and others disclose methods for vacuum vapor depositing and coating these materials thus making it possible to integrate these into vacuum micro embossing at position 9 as described above. Froehlig in U.S. Pat. No. 4,294,782 teaches liquid molding of these materials but the disclosed process teaches the use of molds transparent to the radiation used rather than directing energy into a nip in a vacuum, so the approach is not consistent with using standard electroformed tools and an integrated single machine.
In the case of thermosetting or thermoforming the impression and fixing mechanisms rely on heating in different ways and thus require somewhat different geometry's and proportionality. Thermoforming requires that the surface of the substrate receive sufficient energy to soften the material so that it will accept the impression of the embossing tool, but fixing the features rapidly requires that the bulk of the substrate remain cool so that the embossing is rapidly frozen in place as heat diffuses into the bulk of the substrate. Directing energy into the tool can aid this process by conducting energy into the nip contact point and simultaneously making its distribution across the nip more uniform. The nip pressure must be sufficiently great and uniform and the tool should be insulated from the drum so thermal loss time can be made long enough to aid in forming but short enough to fix the features rapidly. Thermosetting requires no softening so the energy dose should be directed at the embossing tool. In fact it is important to avoid dosing the resin until it has met the embossing tool as otherwise it may harden without taking the impression from the tool. With thermosetting, the dwell time on the drum may need to be extended to assure adequate cure whereas with thermoforming it is desirable to keep this time to a minimum to increase throughput and reduce distortion. With crosslinking it is also desirable to keep the energy beam away from the active substrate surface until the embossing tool nip has been engaged. With charged particles like electrons there is an added enhancing element in the form of secondary electrons and X-rays which can be exploited to increase ionization if the beam strikes the tool at an appropriate grazing angle. The substrate's active coating must be shielded appropriately but a shield may also be a secondary radiation converter if the primary beam incidence is chosen properly.
A preferred embodiment for compensation of thick web distortions encountered in the continuous linear embossing drum method disclosed herein is to use the deformation process itself (or in conjunction with mastering) to compensate. This approach is illustrated in FIG. 2. The second generation tool ("mother"--M) which is used to make the final embossing tool ("stamper") is made in a standard planar electroforming cell. It is mounted on a curved electrode E1 in an electroforming cell which has a radius of curvature R1 significantly smaller than the embossing drum's radius R2. A disk pattern on the surface of the mother with a circular diameter D (indicated by the double headed arrow) is made using standard mastering techniques. When curved to conform to the electrode the double arrow dimension is distorted to a length D-d. The stamper plated in the curved cell will be formed with an oblate circular pattern on the outside of its curved surface by virtue of being plated against the curved mother in the curved geometry of the cell. When the stamper is somewhat flattened onto the more modest radius of curvature of the embossing drum, it will deform to produce an even more oblate pattern with a double headed arrow dimension D-d-c where the added distortion of wrapping on the drum is characterized by the dimension c. This pattern when transferred to a substrate web (W) which is subsequently flattened as shown (coming off the drum) will result in a track pattern diameter double headed arrow of length D-d-c+e. Where e is the prolate expansion that occurs when the thick substrate is returned to a flat geometry. If one wants the final diameter to end up at the value D as shown in the figure then one must arrange that D-d-c+e=D or d+c=e. This is done by calculating the value of R2/R1 and the thicknesses of m and s which will produce the sum of oblate distortions d+c which cancel the prolate distortion e.
In the case where a thin substrate is used and very little effect is encountered in flattening the web, it may actually be necessary for the electroforming cell to have a radius comparable to or larger than the embossing drum (i.e. c may need to have a negative value).
Obviously the above approach will only work with discrete embossing tools that can be manufactured and compensated in this manner, thus requiring the embossing process to be compatible with individual tools obtained by this compensation method.
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.
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Various configurations of a directed energy assisted micro embossing machine/station in a vacuum chamber utilized in a continuous manufacturing process and the web structure products made by that process (optical disks, cards, tapes, holographic reflectors, diffusers, binary optical elements, etc.) are disclosed. The configurations can include a single machine roll to roll system for embossing optical features on the surface of a single substrate and applying appropriate metallic, dielectric, semiconductor, polymer and other coatings all in a vacuum chamber.
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BACKGROUND OF THE INVENTION
The invention relates to a cylinder roller for a textile machine with the cylinder roller having working points, for example the licker-in roll, main cylinder or doffer of a card or the cleaning roller of a blow room machine.
Such cylinder rollers are equipped, depending on the particular task, with a spiked clothing or with a saw tooth clothing and, depending on the particular use, the spikes can be formed by wires of different thickness and the teeth can be executed with different tooth spacings and different sizes. In the case of a spike clothing the wires forming the working points are mainly anchored into a fabric strip. In the case of a saw tooth clothing the teeth are stamped out of an appropriate sheet metal strip and are subsequently ground in order to precisely set the tooth form and to reduce the tooth width in comparison to the base part, whereby in practical use lateral spacings arise between adjacent rows of saw teeth. Both products, i.e. spike clothings and saw tooth strips are available by the meter and are wound during the manufacture of cylinder rollers having working points around the circumference of a drum-like base structure.
In practical use these expensive clothings must be exchanged after longer periods of time due to the effects of wear. It can also transpire that such clothings have to be prematurely exchanged because of locally restricted damage to the working points. In both cases a fairly extensive dismantling of the textile machine is necessary in order to insert the newly clothed cylinder roller. It is also known to draw the saw tooth clothings onto the textile machine itself, whereby the expense of dismantling is substantially smaller. Nevertheless a draw-on process of this kind still requires a relatively large amount of work.
After the draw on process it can be necessary to grind the cylinder roll having the working points so that all working points have precisely the same radial spacing from the rotational axis of the cylinder roll.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a novel cylinder roll having working points of the initially named kind which is cost favorable to manufacture and which enables the repair of damaged regions, or the interchanging of all the working points, without having to build the cylinder roller completely out of the machine. Furthermore, subsequent grinding procedures should be avoided as far as possible.
In order to satisfy this object, provision is made, in accordance with the invention, that the cylinder roller comprises a base structure and clothing segments which are attached thereto and which have the working points, wherein the clothing segments have a regular geometrical shape and are securable adjacent to one another on the base structure to the latter in a repeating arrangement which results in the cylindrical shape.
In this way it is possible, in the event of damage to the working points of the cylinder roller to exchange only one, or, if necessary several clothing segments without having to interchange the entire cylinder roller or the entire working points. When the total cylinder roller is worn, it is possible to exchange the clothing segments while the roller is built into the textile machine, whereby the cost of work and the costs of renewing the working points are likewise reduced. Through the mounting of the working points on the clothing segments, it is also straightforwardly possible to pre-grind these segments in a jig so that the working points have the nominal radial spacing from the axis of rotation of the cylinder roller, or have the radial spacing of the other already installed working points.
In the simplest case, the clothing segments comprise at least two semi-cylindrical shells. Even with this simple embodiment the segments can be interchanged individually or together, since the circumferential extent of the segments, which amounts to less than the half of the cylinder roller, permits the extraction of the latter in a radial direction, which is mainly possible by removing the normal cladding of the machine and turning the roller into a favourable angular position. In this way, it is in most cases not necessary to dismantle the support for the cylinder roller at its end faces.
An even number of semicylindrical shells is preferably provided, which can be mounted pairwise in two or more rows alongside one another on the base structure. An arrangement of this kind is particularly preferred in which, as seen in the circumferential direction of the roller, each row is arranged displaced relative to the neighboring rows. In this manner, the grooves between the working points, which are generally difficult to avoid at the abutting edges between neighboring segments, are so distributed over the circumference of the cylinder roller that they are not disturbing in operation, or only disturb to an insignificant degree. With only two semi-cylindrical shells or several shells aligned in the circumferential direction, empty spaces would extend over, the entire width of the cylinder roller between neighboring shells and these empty spaces are really undesired.
The semi-cylindrical embodiment of the segments does not necessarily represent an optimum. With large cylinder rollers in particular, for example with a tambour (main cylinder of a card), one prefers arrangements in accordance with the invention in which the clothing segments comprise three or more partly cylindrical segments. In this way, the circumferential extent of the individual segments is smaller which makes them easier to handle during installation and dismantling. With this embodiment, with partly cylindrical segments which extend over less than half the circumference of the cylinder roller, one also prefers an arrangement where the clothing segments are arranged in several rows which are each displaced relative to neighboring rows in the circumferential direction of the roller.
A further embodiment which has the special advantage that the abutment regions between the neighboring segments have a shorter linear extent, is characterized in that the segments have a cylindrically curved shape which is polygonal in plan view, for example a triangular, hexagonal or diamond-like shape with part segments optionally being providable at the end edges of the cylinder roller.
In order to secure the segments to the base structure, a particular preferred embodiment of the invention provides that the base structure is a drum having an opening at at least one end face; and that the segments are securable to the drum by means of fastening elements which are accessible from the interior of the drum. In the simplest case, these fastening elements can comprise screws which engage into corresponding threads in the segments. It would also be possible to secure the segments to the drum from the outside, with the securing screws then engaging into threaded bores of the jacket surface of the drum. An arrangement of this kind has, however, the disadvantage that the working tips cannot be straightforwardly provided in the region of the screw heads so that empty spaces arise here which are not absolutely desirable.
In accordance with the invention various other embodiments are, however, also provided for the securing of the segments to the base structure. A particular preferred embodiment is characterized in that the segments are releasably held on the base structure by means of grooves which extend in the circumferential direction and/or in the transverse direction in the base structure or in the segments, with the grooves being in form-locked connection with correspondingly shaped ribs formed on the other respective part.
By way of example, the segments can have dovetail-like grooves or projections at their radially inwardly facing side opposite to the base structure, with these grooves or projections cooperating with projections or grooves of complementary shape in the base structure. It is simplest with an arrangement of this kind when the dovetail-like grooves are provided in the transverse direction of the base structure, since the clothing segments can then be easily inserted from the one end face of the base structure. It is, however, also possible to provide grooves and projections which extend in the circumferential direction of the base structure, although here the grooves and projections must be locally interrupted to enable the introduction of the segments. According to the invention, it is also possible for the segments to have bores which extend in the transverse direction of the roller and for them to be securable to the base structure by means of bars which extend through these bores.
In the case of a spike clothing which is formed by a clothing with a support fabric having wire tips, the support fabric is preferably bonded to the clothing segments, with the fabric preferably having the shape of the segments as seen in plan view. Through this construction regions lacking in points at the abutment edges between the individual clothing segments can be largely avoided. The spike clothing is thus similarly constructed to the spike clothing of a revolving flat.
As an alternative to this, the working points can be formed by a saw tooth clothing which is secured in form-locked manner to the clothing segments, with the saw tooth clothing taking the form of strips curved in the circumferential direction of the cylinder roller. The form-locked mounting can, for example, take place by lip-like projections of the segments which engage over the ends of the strips, and these lip-like projections can be plastically deformed around the ends of the strips or into grooves of these strips provided for this purpose so as to clamp the strips to the segments.
The possibility also exists, amongst other things, of providing the saw tooth strips with dovetail-like grooves of projections at their side facing the segments, with the grooves or projections cooperating with corresponding projections or grooves at the outer surface of the segments and bringing about a form-locked mounting of the strips on the segments. It is, however, also conceivable to provide holes at regular intervals in the saw tooth strips and to then secure these strips to the segments by means of wires which extend in the axial direction of the cylinder roller. Such bores or dovetail-like grooves of projections can be stamped out at the same time as the working points are stamped out, so that the manufacturing complexity is hardly any greater.
Although an exchange of the segments is possible in many cases by radial removal from the base structure, the segments are preferably so provided that they are removable from one end face of the base structure. Depending on the layout of the segments, this is in many cases possible without one having to dismantle the mounting for the cylinder roller, so that the basic alignment of the cylinder roller with the textile machine is not impaired. In this way it is generally also possible to avoid having to dismantle the drive means for the cylinder roller.
Finally, it must also be mentioned that it would basically be possible to provide the segments in ring form. For example, the individual rings could be pushed from one end face onto a drum-like base structure and secured to the latter by axial clamping. A construction of this kind admittedly requires further dismantling of the textile machine at one end face of the cylinder roller than the other embodiments. However, one would in this way largely be able to avoid empty spaces at the abutting edges between the individual segments.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of the invention will now be explained in the following in more detail with reference to the drawings, which show:
FIG. 1 a perspective representation of a first embodiment of the concept of the invention with only two half shells,
FIG. 2 a further embodiment of the concept of the invention with several half shells,
FIG. 3 an embodiment similar to that of FIG. 2, however with part shells which adopt less than half the circumference of the cylinder rollers,
FIG. 4 a perspective illustration of an embodiment of the concept of the invention having several elongate strips,
FIG. 5 a perspective illustration of three variants of the concept of the invention with diamond-like, triangular and hexagonal clothing segments,
FIG. 6 an end view of a clothing segment with wire points,
FIG. 7 an end view of a clothing segment in accordance with the invention having saw-tooth strips which are secured to the segment by means of lip-like projections, with the mounting to the base structure also being shown,
FIG. 8 a further schematic illustration of a clothing segment in accordance with the invention in which individual saw-tooth strips are secured in form-locked manner to the clothing segments by means of dovetail-like grooves and projections, with the mounting to the drum-like base structure also being shown here,
FIG. 9 a further embodiment of a clothing segment in accordance with the invention in which saw tooth strips which themselves form the segments are directly securable to the drum,
FIG. 10 a perspective illustration of an end view of a base structure to which clothing segments are securable by means of dovetail-like guides,
FIG. 11 a perspective illustration of an alternative base structure in which clothing segments are securable by means of dovetail-like guides extending in the circumferential direction of the base structure,
FIG. 12 a schematic illustration of an alternative possibility of securing the clothing segments to the base structure, with the illustrated parts of the clothing segment and of the base structure being shown as a straight line rather than a curve, simply for the sake of illustration,
FIG. 13 a schematic illustration corresponding to FIG. 12, however of a further alternative,
FIG. 14 a schematic illustration corresponding to FIG. 13, however of a yet further alternative, and
FIG. 15 a greatly simplified perspective illustration of a cylinder roller with rows of working points inclined in the circumferential direction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 first shows a cylinder roller 10, for example a doffer of a card which consists of a drum-like base structure 12 and two half shells 14. Each half shell 14 extends over an angle of 180° about the axis of rotation 16 of the roller. The half shells carry a needle clothing of wires 18 at their surface, with the total surface of the two half shells being covered with these wires, although in FIG. 1 only a part region is shown provided with needles in order not to make the drawing unnecessarily complicated.
The abutment edges between the two half shells are characterized by 20. With this wire-spike embodiment it is also possible to bring the needles very close to the abutment edges 20 so that no particular disruption of the needle covered surface occurs in the region of the abutment edges 20.
FIG. 1 also shows how the drum-like base structure 12 is secured by means of radially extending arms 22 to the hub part 24, which is necessary for the mounting of the cylinder roller in the textile machine. This mounting is not shown here because it does not belong to the present invention. Similar radial arms 22 and hub parts 24 are also provided in the further embodiments.
As will later be explained in more detail in connection with FIG. 6 the wire needles 18 are firmly anchored into a fabric which is bonded to fixed metallic segments. The mounting of the segments to the drum 12 takes place by means of screws which are inserted from the inside of the drum and engage into threads provided in the segments, as will be explained later with reference to FIG. 6. Simply for the sake of illustration, the head of a screw 26 is shown in FIG. 1 and one can see that this head is accessible through the opening 28 between the arms 22.
The working tips of the half shells 14 of the embodiment of FIG. 1 do not have to consist of wire needles, they can for example equally consist of saw-tooth segments as will be explained later in connection with FIG. 7.
In this case it is simpler, for technical manufacturing reasons, to provide the half shells with a somewhat smaller axial length. FIG. 2 shows an embodiment of this kind in which four pairs of half shells 14.1 are arranged alongside one another. For the sake of illustration, the base structure, i.e. the drum 12 in FIG. 2, is omitted. The abutting edges 20.1 between the pairs of half shells are displaced in each row relative to the adjacent rows so that no regions which are devoid of saw teeth and which extend over the whole axial length of the roller are present at the abutment edges 20.1.
The displacement of the individual half shells in the individual rows can be so effected that the abutting edges in one row are displaced relative to the abutting edges in all other rows. This is however not shown in FIG. 2.
The present invention is in no way restricted to two half shells. FIG. 3 shows an arrangement with a total of 40 shell segments which are arranged in four rows of ten segments each, with each segment 14.2 having an angular extent of 36°. Here the abutting edges 20.2 are also displaced relative to the abutting edges of neighboring rows. In addition, the base structure has also been omitted here for the sake of illustration.
FIG. 4 again shows a segment arrangement with 16 strip segments 14.3 which each extend over the full length of the cylinder roller. An arrangement of this kind is suitable for a needle clothing with wire needles which are embedded and held in a fabric, with this fabric being bonded in strip form to the segments 14.3, with the strips having the shape of the segments 14.3, which is only indicated regionally at 30 in FIG. 4. The strips having the needle clothing can be formed in the manner which is customary for the needle clothings of revolving flats.
FIG. 5 shows three further alternative types of segment which are here formed as mosaic tiles. In the first case the segments 14.4 are diamond-like segments. In place of this the segments could also have a triangular shape 14.5 or a hexagonal shape 14.6, and finally any form of polygonal shape is possible providing the segments can fully cover a surface. In some embodiments of the mosaic tiles, half segments must be provided in order to also achieve a continuous cover of the base structure at the end edges of the cylinder roller, as is for example indicated at 14.7.
FIG. 6 now shows an end view as to how a segment, for example a segment such as 14.2 of FIG. 3, can be secured to the drum-like surface of the base structure 12. As evident, the segment 14.2 has a curved inner surface 32 which has precisely the same curvature as the outer surface 34 of the drum. Four threaded bores 36 are provided in the segment 14.2 of which only two are visible in FIG. 6. The segments can be drawn tight onto the base structure by means of screws 26, the drive heads of which are located in the internal space of the drum-like base structure 12. The segments can also have a nose 38 and a recess 40 at their respective edges in the circumferential direction so that each segment 14.2 is held in form-locked manner at the circumferential edge by the neighboring segment 14.2. With suitable shaping, the noses and the recesses can be so laid out that it is nevertheless possible to release individual segments from the drum, for example by first releasing two neighboring segments and then tightening them again pairwise onto the drum surface by means of the screws 26.
FIG. 6 shows in detail how the wire tips 18 project out of a fabric 30, with the fabric 30 frequently being bonded to the curved outer surface of the segment 14.2. In this manner, no circumferential grooves arise at the abutment edges 20.2 because the wire spikes can be led at least substantially up to the edge of the strips.
FIG. 7 shows an embodiment similar to that of FIG. 6 in which the segments 14.8 are likewise drawn onto the drum surface by means of screws 26. For the sake of brevity the parts in FIG. 7 which correspond to parts of FIG. 6 are designated by the same reference numerals and will not be specially described. The embodiment of FIG. 7 is equipped with saw-tooth strips, with these saw-tooth strips having a curvature corresponding to the curvature of the outer surface of the segment 14.8 and being secured at their end edges by means of inwardly deformed edge parts 42 of the segments 14.8. Although not shown in FIG. 7, several saw-tooth strips are placed alongside one another on the segment, with each strip having in known manner a broader shoulder region 44 and a narrower width at the working points, so that the working points 46 are spaced from each other. At the abutment edge between two segments, for example at 20.2 a small spacing arises here having the width of one tooth.
FIG. 8 shows a further embodiment of securing the saw-tooth strips 41 to the segments 14.9. In this embodiment parts which are already known are designated with the same reference numerals as before and will not be specially described. In the embodiment of FIG. 8, one sees that the segment 14.9 has dovetail-like guides 48 at its outer side, with these guides engaging into complementary dovetail-like openings 50 in the saw-tooth strips 41 and thus securing the saw-tooth strips in form-locked manner to the segment. This embodiment has the special advantage that individual saw-tooth strips on individual segments are interchangeable.
In the embodiment of FIG. 9, the saw-tooth strips themselves form the segments. For this purpose they are made somewhat deeper than previously in the radial dimension and provided with throughgoing holes 52. The matching drum structure is constructed as a bird cage, with the individual cage bars extending through the holes 52. The exchanging of the saw-tooth strips is possible here by pulling the bars out regionally and removing the corresponding saw-tooth strips. As an alternative to the this, the base structure can have the form of a drum with a plurality of radially outwardly projecting flanges, with grooves into which the saw-tooth strips are inserted being provided between the ring-like flanges. These flanges also have bores corresponding to the bores 52 so that the bars can pass both through the saw-tooth strips and also through the flanges. A mounting of this kind is particularly suitable for a cylinder roller of a cleaning machine where a relatively coarse tooth form is used.
FIG. 10 shows an embodiment for mounting individual segments 14.10 to the drum-like base structure 12.1 by means of dovetail-like guides 54 which extend in the transverse direction of the roller and which engage into dovetail-like grooves 56 of complementary shape in the inner sides of the segments 14.10. For the sake of illustration, the working points are omitted here. They can, however, be executed as wire points or as saw-tooth points and can, for example, be secured to the segments 14.10 in accordance with the previously described embodiments.
FIG. 10 also shows a flange 58 at the rear end edge of the cylinder roller as seen in the drawing, with this flange serving as an abutment for the segments 14.10 which are inserted in the axial direction. In order to show this flange 58 the other segments in FIG. 10 are broken away.
FIG. 10 also shows a further alternative, namely the mounting of the segments 14.10 to the base structure 10 by means of throughgoing strips 57. The strips 57 can have the cross-sectional shape of two oppositely directed dovetail guides which are secured to one another. In this case, corresponding dovetail guides are provided both in the segments and also in the base structure. The strips can be inserted sideways in the form of prefinished strips. They can, however, also be produced by casting the corresponding spaces out with lead, a low melting point alloy, a resin composition or plastic. In this case, the mounting between the clothing segments and the base structure is finished after hardening or curing of the material.
The dovetail-like guides do not necessarily have to extend in the transverse direction of the roller but rather they can extend in the circumferential direction as shown in FIG. 11. The embodiment of FIG. 11 would, for example, be suitable for a segment shape in accordance with FIG. 4, i.e. segments which have a length corresponding to the length of the cylinder roller which are, however, relatively narrow in width. To enable the introduction of the segments the drum has at least one row of positions 59 where the circumferentially extending dovetail guides 54.1 are interrupted. The individual strips can be inserted at these positions and then displaced in the circumferential direction. The regions 59 are thus to be regarded as filling slots. After inserting the last strip, all the strips are displaced backwards by one half strip so that the two last inserted strips are also carried by the dovetail-like guides 54.1. A secure mounting of the last inserted strips can then be achieved with other mechanical means, for example with a screw which engages into a threaded bore formed at the joint between the two strips, i.e. with one half of the threaded bore in the one strip and the other half of the threaded bore in the other strip.
A further embodiment lies in dividing the circumferentially extending dovetail-like guides 54.1 into various narrow strips, for example as shown in 54.2. The segments to be inserted then have a corresponding subdivision of the dovetail-like groove recesses, so that they can be inserted radially. After radial insertion, the strips are displaced through half their width so that they are held in form-locked manner.
The above described embodiments only represent some of all the contemplated embodiments which exist for realizing the invention in practice.
Further embodiments are shown in FIGS. 12 to 15.
In FIG. 12 the clothing segments, which can, for example, be formed in correspondence with the segments 14.2 of FIG. 3, are secured by means of throughgoing screws 26.1 to the base structure 12. In so doing, the screws 26.1 thereby pass through radial bores 60 and 60.2 which are aligned with one another and which are formed in the clothing segments 14.3 and in the base structure 12, respectively. The bores 60 are formed as stepped bores so that the head of the screw 26.1 can be arranged sunk beneath the radially outer surface of the clothing segment 14.3. The threaded part of the screw 26.1 engages into the bore 62 of the base structure 12 with this bore being formed as a threaded bore.
FIG. 13 shows a similar construction, however with a somewhat different securing means 26.2. Here the securing means 26.2 has a claw 64 at its lower end which is connected by means of a limb 66 with the head of the screw 26.2. The claw is so constructed that it can be inserted through the mutually aligned bores 60 and 62 and then passes behind the radially inner surface of the base structure 12 and is anchored here by rotation of the head of the screw, for example by means of the screw driver slot 68. In order to facilitate this, the claw 64 has a surface 64.1 which is formed as a ramp which also makes it possible to tighten the screws 26.2.
In the securing means of FIG. 14 a spreading dowel 70 is used in order to realize the fastening.
After mounting the segment 14.3 on the base structure 12, the dowel 70 is pushed through the mutually aligned bores 68 and 62.1 with the conical shape of the bore 62.1 preventing the dowel 70 which is inserted from migrating too far inwardly. Finally, the screw 26.3 is inserted through the dowel and tightened, whereby the nut 72, which cooperates with the screw 26.3, takes care of the spreading of dowel 70 and, thus, the anchoring of the clothing segment 14.3 on the base structure 12. The use of a nut 72 of this kind is not absolutely essential. The screw 26.3 could, for example, bring about adequate spreading of the dowel to ensure the anchoring without the nut.
In the examples of FIG. 12 to 14, the heads of the screws can, if desired, be covered over with covers, including covers which themselves carry needle clothings. These covers could, for example, be bonded onto the screw heads or could be provided with screws which can be threaded into corresponding threaded bores of the screws 26.1, 26.2 or 26.3 respectively, i.e. approximately in the manner of cover caps with bathroom mirrors.
Finally, FIG. 15 shows that the roWs of working points of clothing segments which follow one another in the circumferential direction of the cylinder roller can form an angle with the circumferential direction. This has the special advantage that the "alleys" between the rows of working points are not straight and aligned in the circumferential direction of the cylinder roller but rather form a zig-zag track, with individual fibres being repeatedly brought back into the working region of the working tips, so that on the whole a high degree of efficiency is achievable.
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A cylinder for a textile machine to be used as a licker-in, main cylinder or doffer has working clothing attached to the base structure. The clothing is attached in segments that have a regular geometric shape and a width less than the cylinder width. The segments are secured to the base structure so that the junctions, in the peripheral direction, are displaced from one another. Each segment is provided with a form locking edge to innerlock the segments in the cylindrical form.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to a wind turbine.
Modern wind turbines are divided into two major categories: horizontal axis turbines and vertical axis turbines. Horizontal axis wind turbines typically comprise a tower and a fan-like rotor mounted at the top of the tower for rotation about an axis substantially parallel to the earth's surface. The rotor of a horizontal axis wind turbine must face either into or away from the direction of the wind and a yaw mechanism is required to rotate the rotor about the vertical axis of the tower to keep the rotor in proper alignment with the wind flow. Since a mechanical means of delivering power to the ground could cause the rotor to yaw out of alignment with the wind, energy conversion devices, such as generators; power transmission equipment; and related equipment are typically also mounted atop the tower. A structurally robust and costly tower is required to support the weight of the elevated equipment. In addition, the tower structure must be resist oscillation and fatigue resulting from pressure pulsations produced by the interaction of the moving rotor blades and the tower. Likewise, the pressure pulse created by the wind shading of the tower causes the blades of the rotor to flex inducing fatigue in the blades and other rotor components. Maintenance of horizontal axis turbines can be complex because the equipment is located at the top of the tower. A large crane is typically required to replace equipment or to support the rotor during bearing replacement or maintenance. While horizontal axis wind turbine installations are relatively complex and expensive, they are the most common wind turbine configurations in current use.
Vertical axis wind turbines comprise, generally, a central shaft arranged vertically with respect to the ground and rotatably supporting a plurality of blades or vanes arrayed around the shaft and roughly perpendicular to the wind flow. Vertical axis turbines do not require a yaw mechanism to align the blades with the wind and the generator or other energy converter and related power transmission equipment may be mounted on the ground at the base of the turbine, potentially substantially reducing the complexity and cost of the installation.
Vertical axis wind turbines are divided generally into lift- and drag-types. Drag-type vertical axis wind turbines, exemplified by the three-cup anemometer and the Savonius wind turbine, are rotated by the force produced by the wind impinging on the exposed area of cups, buckets, or paddles arranged around a vertical shaft. Savonius, U.S. Pat. No. 1,697,574, incorporated herein by reference, discloses a vertical axis wind turbine that can be described as a barrel cut in half lengthwise with the halves offset to form two scoops and mounted on a vertical shaft. The efficiency of a Savonius turbine is limited because power produced by the gathering side of the rotor is offset by drag produced by the other side of the rotor. In addition, since the area of the scoops exposed to the wind flow varies as the turbine rotates, the torque is not even throughout a revolution of the shaft and no torque will be produced to initiate rotation if the rotor is improperly aligned with the wind flow. Further, the maximum velocity of the cups or paddles of a drag-type turbine is substantially equal to the velocity of the wind (tip speed ratio≈1). While this type of turbine can produce high torque and can be useful for pumping water and similar tasks, the speed of rotation is generally too slow for efficient production of electricity, a major use of commercial wind turbines.
Lift-type vertical axis turbines rely on the lift force generated as the wind flows over an air foil to obtain tip speeds exceeding the wind's velocity. Darrieus, U.S. Pat. No. 1,835,018, incorporated herein by reference, discloses a wind turbine typifying lift-type vertical axis wind turbines. The Darrieus wind turbine is the only vertical axis wind turbine ever manufactured commercially in any volume. The Darrieus wind turbine may comprise C-shaped rotor blades attached at their top and bottom ends to a vertical central shaft or rectilinear blades arranged parallel to the shaft in a cylindrical drum or squirrel cage arrangement (sometimes referred to as a “Giromill”). Darrieus turbines typically have two or three blades. Since lift forces provide the torque for rotation, the tip speed of the blades can exceed the speed of the wind. Darrieus wind turbines can have a tip speed ratio exceeding three making this type of turbine suitable for electric power generation.
While vertical axis wind turbine installations are potentially less complex and costly than horizontal axis turbines, the lack of commercial success of vertical axis turbines is indicative of substantial drawbacks of this type of turbine. Since no tower is required, a major cost of a wind turbine installation is eliminated. However, wind speeds close to the ground are very low and turbulent due to boundary layer effects. As a result, the output of a vertical axis turbine, particularly the lower half of the rotor, is limited and the overall efficiency is relatively low. Further, guy wires may be required to stabilize the vertical shaft which may make the turbine impractical in extensively farmed or built-up areas. While the power conversion equipment can be mounted at ground level, a crane is typically required to lift the vertical shaft and blades for bearing replacement or maintenance. In addition, lift-type vertical axis turbines are not self starting, but an electric generator connected into a power grid can be used as a motor to start the turbine.
What is desired, therefore, is a wind turbine combining the lower cost and reduced complexity of a vertical axis wind turbine with the higher efficiency and performance of a horizontal axis wind turbine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cut-away perspective view of an electric power generation installation incorporating a vertical axis embodiment of the wind turbine.
FIG. 2 is a sectional view of the elevation of the electrical power generation installation of FIG. 1 .
FIG. 3 is a sectional view of an elevation of the inventive wind turbine.
FIG. 4 is an elevation view of a wind turbine.
FIG. 5 is a section view of the wind turbine of FIG. 4 along line Z—Z of FIG. 4 .
FIG. 6 is a bottom view of the wind turbine of FIG. 4 .
FIG. 7 is a schematic illustration of a method of generating the shape of a vane of the wind turbine.
FIG. 8 is a section view of a vane of the wind turbine along line v—v of FIG. 4 .
FIG. 9 is a perspective view of a horizontal axis embodiment of the inventive wind turbine.
DETAILED DESCRIPTION OF THE INVENTION
Referring in detail to the drawings wherein similar parts of the invention are identified by like reference numerals, and, more specifically to FIGS. 1 and 2 , a wind power energy converter for generating electricity 20 is illustrative of a vertical axis embodiment of the inventive wind turbine system. The energy converter installation 20 comprises, generally, a foundation or base 22 supporting a tower 24 which, in turn, supports the wind turbine 26 . One or more electric power generators 28 are located on the foundation 22 and driven by a flywheel 34 . The generators 28 are connected to the flywheel 34 by drive shafts 30 that are connected to a right-angle drive 32 that is rotatably connected to the flywheel. The right angle drive 32 may also include variable ratio gearing or other power transmission components, such as a hydrostatic pump and motor, to control the speed of rotation of the generator 28 under variable wind conditions. A power transmission apparatus rotatably connects the flywheel 34 and the wind turbine 26 at the top of the tower 24 . The exemplary power transmission apparatus, as illustrated in FIGS. 1 and 2 , includes a clutch 33 to selectively connect the flywheel 34 to a main drive shaft 36 that is connected to and rotated by the wind turbine 26 . However, other known power transmission apparatuses could be used to transfer power from the wind turbine 26 to the flywheel 34 . For example, a hydraulic pump connected to be driven by the wind turbine 26 could supply pressurized fluid to drive a hydraulic motor connected to rotate the flywheel 34 . While the illustrated energy converter installation 20 incorporates electrical generators, pumps or other energy conversion devices attached to the flywheel could be used to convert the rotational energy of the wind turbine to an elevated fluid or another form of energy. Likewise, the energy converter installation 20 includes a right angle drive 32 , but the generator 28 , other energy conversion devices, and power transmission devices could be mounted in-line with the main drive shaft 36 .
The tower 24 is typically cylindrical and may be constructed of any convenient material providing the necessary strength, rigidity, and other desired properties. For example, the tower 24 may comprise multiple pre-cast, tubular, reinforced concrete units with internal post tensioned cables, if necessary, for tower stabilization. The tower 24 is attached to the foundation 22 which may surface mounted or completely or partially buried, as determined by the installation's siting limitations. Referring to FIG. 3 , the turbine 26 is rotatably supported at the top of the tower 24 by upper 40 and lower 42 bearings. The upper bearing 40 bears on an upper bearing support 44 attached to the tower 24 and on a hub 46 at the center of an upper vane support 48 . The hub 46 of the upper vane support 48 is bolted 50 to a flange on the end of the main drive shaft 36 so that the main drive shaft will rotate with the upper vane support. At its lower end, the turbine 26 is rotationally supported by the lower bearing 42 that bears against a lower bearing support 52 attached to the tower 24 and a hub 53 of a lower vane support 54 .
The shells of a plurality of hydraulic rams 56 are attached to the tower 24 . The movable piston rods 58 of the rams can be extended to bear against the hub 46 of the upper vane support 48 . When replacing the upper 40 and lower 42 bearings, the turbine 26 can be raised to facilitate bearing removal by extending the piston rods 58 of the appropriate hydraulic rams 56 .
The wind turbine 26 typically comprises 5–15 vanes 80 attached to vane attachment rings 60 , 62 supported by spokes 64 , 66 radiating from the central hubs 46 , 53 of the upper 48 and lower 54 vane supports, respectively. Referring to FIGS. 5 and 6 , when viewed in the direction of the rotational axis 82 of the turbine 26 , the vanes 80 form an annular envelope with an open center. The shape of the exterior envelope of the turbine 26 is typically that of a prolate spheroid. The height 91 (indicated by a bracket) of the wind turbine 26 is typically less than 50% of the height of the tower 24 to limit the forces acting on the tower and the resultant stress in the tower components. Turbines having a diameter to height ratio between 0.45 and 0.90, and, preferably, between 0.60 and 0.80 provide a desirable balance of speed and torque, producing ample power and limiting stress on the turbine components.
The vanes 80 of the wind turbine 26 comprise a surface 94 bounded by a leading edge 100 , a trailing edge 102 , a upper end 86 , and a second end 88 . A line connecting and approximately bisecting the upper end 86 and the lower end 88 defines a substantially longitudinal axis 90 of the vane 80 . A line extending transverse to the longitudinal axis defines a substantially lateral, chord axis 96 of the vane 80 . Referring to FIG. 7 , the shape of the surface 94 of the vane 90 substantially corresponds to a portion of the surface of a prolate spheroid 150 that would be overlaid if a planar blank 156 of the vane was aligned with its longitudinal axis 152 skewed relative to the polar axis 154 of the spheroid and then wrapped over the surface of the spheroid. Typically, the longitudinal axis 152 of the blank is skewed between 30° and 60° to the polar axis of the spheroid for the purpose of generating the surface but other lesser or greater angles of skew can be used. The leading 100 and trailing 102 edges of the vane 80 are elongated S-curves extending between the upper 86 and lower 88 ends of the vane. The elongated S-curves result from overlaying the blank 156 of the vane, having edges spatially corresponding to the leading 100 and trailing 102 edges of the vane and defined by sine waves having neutral axes substantially parallel to the longitudinal axis of the vane,on the surface of the spheroid 150 .
Referring to FIG. 8 , when viewed in the direction of the longitudinal axis 90 , the surface 94 of the vane 80 has an elliptical profile. The shape of the ellipse is determined by the lengths of a minor axis 180 extending perpendicular to the surface 94 and a major axis 182 (indicated by a bracket) extending in the direction of the chord axis 96 of the vane 80 . The minor axis 180 varies in length from the upper end of the vane to the lower end of the vane so that the elliptical profile of the surface 94 takes the form of a truncated, conical ellipse. When viewed in the direction of the longitudinal axis 90 , the vane 80 is substantially planar at its upper end 86 , as illustrated in FIG. 5 , and substantially curved at its lower end 88 , as illustrated in FIG. 6 . Air flowing over the curved surface 94 of the vane 80 generates a lift force to rotate the turbine and the cupped profile of the reverse surface 95 of the vane enhances turbine start-up by catching the wind.
Referring to FIG. 3 , when attached to the upper 48 and lower 49 vane supports, a vane 80 is positioned such that the longitudinal axis 90 of a first length of the vane, approximately midway between the upper 86 and lower 88 ends, is skewed at a first angle 104 to the rotational axis 82 of the wind turbine 26 . The first angle 104 is greater than 15° and less than 90° and typically, in the range of 22°–44° to the rotational axis of the wind turbine. Skewing the longitudinal axis 90 of the vane 80 relative to the rotational axis 82 of the turbine 26 increases the chord line of the airfoil as defined by Bernoulli's Law and increases the ram pressure exerted on the vane by the wind to increase the lift force and reduce drag forces. The elongated S-curve of the leading 100 and trailing 102 edges causes the portions of the longitudinal axis extending through a second length and a third length proximate the upper 86 and lower 88 ends of the vane 80 to be substantially parallel to each other and skewed at an angle to the rotational axis of the turbine that is greater than the first angle, reducing the effects of vortices at the tips of the blades and improving the ability of the vane to catch the wind during startup.
The vanes 80 are mounted with the leading edge 100 of each vane projecting radially outward of the trailing edge 102 of the adjacent vane. The shape and arrangement of vanes maximize surface exposure and lift coefficient and minimize wind shading effects produced by the preceding vane. In addition, the air flow through the turbine 26 raises the air pressure in the interior of the annular turbine. The higher pressure in the center of the turbine produces thrust on the wind wane side of the vanes 80 for additional turbine speed and torque. Wind flowing horizontally from any direction at any speed, or wind shear flowing parallel to the axis of rotation 82 of the turbine 26 will create a force to rotate the turbine.
A cap 27 , attached to the upper vane mounting 48 , covers the exposed upper ends 86 of the vanes 80 . The cap 27 reduces turbulence in the air flow and stabilizes the turbine.
While the tower 24 elevates the turbine 26 to take advantage of the higher velocity, less turbulent wind above the earth's surface, the structural requirements and cost of the tower are less than that required for a typical horizontal axis turbine. The tower is not required to support the weight of the generator and mechanical power transmission equipment. Further, tower oscillation and fatigue caused by the pressure wave produced by the interaction of the tower and the blades of a horizontal axis turbine and the pitch and yaw forces generated by the rotor are substantially reduced or eliminated, reducing structural requirements and improving tower stability. There is no appreciable wind shading interaction between the centrally located tower 24 and the turbine 26 .
Rotation of the turbine 26 is transferred to the generator 28 through the main drive shaft 36 connecting the hub 46 of the upper vane support and a clutch 33 at the input to the right-angle drive 32 . A variable mass flywheel 34 is also attached to the input to the right-angle drive 32 to modulate speed fluctuations produced by gusting winds and prolong the output of the generator 28 when the wind dies down. The variable mass flywheel 34 comprises a hollow ring torus 120 connected to a radially centered hub 124 by a plurality of tubular spokes 122 . The hollow toroidal tube 120 is elevated relative to the hub 124 so that a fluid, such as water, in the torus 120 will flow toward the hub, through the tubular spokes 122 , when the flywheel is stationary or turning slowly. On the other hand, when flywheel 34 is rotating, centrifugal force causes fluid pumped into the hub 124 by a pump 128 and controlled by the fluid control 130 , to flow outward through the spokes 122 to the toroidal tube 120 . Baffles internal to the torus 120 cause the fluid to rotate with the flywheel 34 . Adding fluid to the flywheel 34 increases the mass and inertia of the flywheel increasing the amount of energy that can be stored by the flywheel and enabling the flywheel to absorb greater speed fluctuations. Draining fluid from the flywheel 34 reduces the mass and inertia of the flywheel to ease turbine start-up.
Referring to FIG. 9 , the innovative turbine can also be constructed as a horizontal axis wind turbine 200 . The horizontally extending central shaft 202 is supported in a yoke 204 that is rotatable on a base 206 to facilitate yaw to align the shaft parallel to the wind flow. The turbine is responsive to wind flow substantially parallel to the shaft, either wind shear in a vertical axis configuration or wind flow parallel to the earth's surface in a horizontal configuration 200 . A horizontal axis is desirable when the overall height of the turbine is limited, for example, when the turbine is used to power a ship.
The detailed description, above, sets forth numerous specific details to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuitry have not been described in detail to avoid obscuring the present invention.
All the references cited herein are incorporated by reference.
The terms and expressions that have been employed in the foregoing specification are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims that follow.
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A wind turbine operable as either a vertical axis wind turbine or a horizontal axis wind turbine is disclosed.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/713,902, filed Oct. 15, 2012, which is hereby incorporated by reference herein in its entirety.
BACKGROUND
[0002] Existing digital orthodontic systems utilize digitized images of the teeth to generate a customized treatment system of brackets, transfer jigs and wires. This system assumes that all of the custom designed brackets and transfer jigs can be placed on the facial or labial surface of the tooth. Unfortunately, for some patients a tooth may be rotated or otherwise malpositioned such that the facial surface is not facing outward or the tooth has not fully erupted through the gums. In these situations, the orthodontist must first recognize the problem condition and then use manual techniques to de-rotate or otherwise move the tooth so that the “customized” system can then be placed. Given the cost of such customized systems, it then becomes less desirable to use a customized orthodontic set because the orthodontist must use traditional techniques in addition to the customized versions.
[0003] The devices, systems, and methods disclosed herein overcome one or more of the deficiencies of the prior art.
SUMMARY
[0004] In a first aspect, the present disclosure provides a method for computer aided tooth alignment correction. The disclosed method includes determining sequential brackets and placement locations on the same tooth to accomplish a computer aided treatment plant. In one aspect, the method can include receiving digital information regarding initial teeth positions; determining desired final teeth positions and a treatment plan of ideal brackets, jigs and wires for achieving the final teeth positions; identifying whether there will be interferences between at least one of the ideal brackets, jigs, wires, teeth and gums; and upon identification of interferences, generating one or more sequential treatment modules addressing the identified interference. In a further aspect, the method further includes packaging the ideal brackets and jigs along with the sequential treatment module.
[0005] In a further embodiment, the present disclosure provides a tooth correction system that can be applied in a sequential manner to the same tooth. In one aspect, the correction system includes a first transfer jig having an occlusal surface configured to engage the occlusal surface of a tooth and a mounting surface having a bracket holding feature, the mounting surface configured for orientation with a first surface of the tooth having a first plane offset at a first acute angle from the tooth longitudinal axis. In another aspect, the system includes a second transfer jig configured to engage the occlusal surface of the tooth and having a second mounting surface having a second bracket holding feature, the second mounting surface configured for orientation with a second surface of the tooth having a second plane offset at a second acute angle from the tooth longitudinal axis. Still further, the system can include a plurality of ideal transfer jigs in addition to the first transfer jig and the second transfer jig, each of the plurality of ideal transfer jigs adapted for engaging different teeth within a patient's mouth and having a mounting surface having a bracket holding feature, the mounting surface configured for orientation with a facial surface of the tooth.
[0006] In yet a further aspect, the present disclosure contemplates a tooth correction kit comprising a plurality of tooth brackets and a plurality of transfer jigs for positioning the tooth brackets at a predetermined location on the teeth, wherein at least two of the tooth brackets are designed for sequential placement on the same tooth. The tooth correction kit can further included at least two transfer jigs configured for engaging the same tooth at two different angular positions with respect to the longitudinal axis of the tooth.
[0007] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings illustrate embodiments of the devices and methods disclosed herein and together with the description, serve to explain the principles of the present disclosure. Throughout this description, like elements, in whatever embodiment described, refer to common elements wherever referred to and referenced by the same reference number or character. The characteristics, attributes, functions, interrelations ascribed to a particular element in one location apply to those elements when referred to by the same reference number or character in another location unless specifically stated otherwise.
[0009] The figures referenced below are drawn for ease of explanation of the basic teachings of the present disclosure only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the following embodiments will be explained or will be within the skill of the art after the following description has been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following description has been read and understood.
[0010] The following is a brief description of each figure used to describe the present invention, and thus, is being presented for illustrative purposes only and should not be limitative of the scope of the present invention.
[0011] FIG. 1 is a stylized view of a portion of a computer aided treatment plan according to a prior art system.
[0012] FIG. 2 is a stylized view of a portion of a computer aided treatment plan according to an as aspect of the present disclosure.
[0013] FIG. 3A is top view of a transfer jig and bracket system being applied to a series of teeth.
[0014] FIG. 3B is a partial cross sectional side view of the transitional jig and bracket of FIG. 3A .
[0015] FIG. 4 is a top view of the transitional bracket of FIG. 3A bonded to the tooth and attached to the wire in an initial position.
[0016] FIG. 5 is a top view of the transitional bracket of FIG. 3A bonded to the tooth and attached to the wire in a first transitional position.
[0017] FIG. 6A is top view of a second transfer jig and bracket system being applied to the series of teeth.
[0018] FIG. 6B is a partial cross sectional side view of the second transitional jig and bracket of FIG. 6A .
[0019] FIG. 7 is a top view of the second transitional bracket of FIG. 6A bonded to the tooth and attached to the wire in a first transitional position.
[0020] FIG. 8 is a top view of the second transitional bracket of FIG. 6A bonded to the tooth and attached to the wire in a second transitional position.
[0021] FIG. 9 is a top view of an ideal bracket of FIG. 1 bonded to the tooth in the second transitional position of FIG. 8 .
[0022] FIG. 10 illustrates the ideal bracket of FIG. 9 attached to the wire.
[0023] FIG. 11 illustrates the ideal bracket of FIG. 9 with the tooth shown in the finished rotational position.
[0024] FIG. 12 is a stylized version of a bracket and transfer jig system for treating a patient's teeth according to one aspect of the present disclosure.
[0025] FIG. 13 is an exemplary derotation module associated with the bracket and transfer jig system of FIG. 12 according to another aspect of the present disclosure.
[0026] FIG. 14 is a block diagram of a process flow implementing at least one aspect of a computer aided sequential treatment system.
DETAILED DESCRIPTION
[0027] For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately. For simplicity, in some instances the same reference numbers are used throughout the drawings to refer to the same or like parts.
[0028] Referring initially to FIG. 1 , there is shown a graphic representation of the output of a computer aided bracketing system treatment plan. Features of such systems are described in the U.S. Pat. Nos. 5,368,478; 6,358,044; 6,846,179; 7,641,473; and 7,869,983 the disclosure of each of with is incorporated by reference herein in their entirety. Stylized images of digitized teeth T 1 , T 2 and T 3 are shown in their original starting position. Each tooth T 1 , T 2 , and T 3 has a longitudinal axis L 1 , L 2 , and L 3 generally aligned with trough 158 , 258 and 358 , respectively. Teeth T 1 and T 3 have generally aligned axes L 1 and L 3 with facial surfaces 150 and 350 , and lingual surfaces 156 and 356 of teeth T 1 and T 3 each oriented facial and lingually, respectively. As shown in FIG. 1 , the axis L 2 of tooth T 2 is rotationally offset from the axis L 1 of the adjacent tooth T 1 by an angle A 2 . In the illustrated embodiment, the angle A 2 is approximately 70 degrees, although this angle could range from 15-110 degrees. Given the rotational offset of the tooth T 2 with respect to the adjacent teeth, the facial surface 250 is facing tooth T 1 while the lingual surface 256 is facing tooth T 3 . Similarly, the side surface 252 is oriented facially along with the more highly curved transition zone 254 extending between the facial surface 250 and the side surface 252 . The side surface 253 opposing the surface 252 is disposed generally lingually in the illustration of FIG. 1 while the lingual surface 256 is substantially facing toward tooth T 3 .
[0029] Existing computer aided orthodontic appliance planning systems utilize the starting position of the digitized teeth to develop a placement plan for a bracket and wire system to move the teeth to a desired finished position. In the illustrated version, the system determines the “ideal position,” generally the midpoint, 160 , 260 , and 370 of the facial surface of each tooth T 1 , T 2 and T 3 , respectively. The system then assigns a bracket to be placed on the tooth in the ideal position to accomplish the movement to the final position. Based on calculations performed by a processor executing a treatment program, the brackets I 1 , I 2 and I 3 are considered the “ideal” brackets to accomplish the tooth movement from the starting position into the final, finished position. In the ideal position, the axis of each ideal bracket intersects the tooth axes L 1 , L 2 , and L 3 , respectively, at a substantially perpendicular angle. For example, in the ideal position 260 , the axis LI 2 of the ideal bracket I 2 for tooth T 2 intersects the tooth axis L 2 at a substantially perpendicular angle.
[0030] However, as shown in FIG. 1 , bracket 12 has an overlap zone 230 with adjacent tooth T 1 . It will be appreciated that the bracket I 2 cannot be placed in the ideal position 260 on the facial surface 250 of tooth T 2 in the current orientation because there would be interference between the bracket I 2 and adjacent tooth T 1 . Other forms of interference can also be determined by the computer aided design system, such as bracket to tooth, jig to tooth, bracket to gum, and wire to tooth interferences. When such interferences are identified, the proposed computer aided treatment plan must be abandoned in favor of a traditional manually defined treatment plan or the tooth T 2 must be manually realigned before the computer aided treatment plan can be applied. In either situation, the healthcare provider must make adjustments to the position of at least tooth T 2 based on observation and without the benefit of a computer aided treatment plan that will lead the to the fastest, most accurate correction of the teeth.
[0031] Referring now to FIG. 2 , there is shown an output of a computer aided treatment plan to move teeth T 1 , T 2 and T 3 into a final position. As illustrated, the computer aided treatment plan has determined that based on the angle of rotation A 2 of tooth T 2 , two rotational brackets A and B will be need before the ideal bracket 12 can be applied to at the ideal position central facial surface. Thus, a transitional tooth module has been defined by the system to include three brackets A, B and 12 , each being placed at a different angular location on the tooth in relation to axis L 2 . A description of the system for determining whether a derotation module will be initiated and what the components will is described below in relation to FIG. 14 .
[0032] As shown in FIG. 2 , while there is minimal overlap between bracket B and tooth T 1 , the system determined that the transfer jig 600 (shown in dashed lines) needed to properly place bracket B created a zone of overlap 602 , thus requiring placement of the initial bracket A. The bracket A will be placed at a first offset position on a plane of the tooth T 2 with the bracket axis LA intersecting the tooth axis L 2 at a first offset angle A 3 . The first offset angle A 3 is an acute angle relative to the tooth axis L 2 . In the first offset position, at least a portion of a mounting pad 603 of the bracket A is bonded to the side surface 252 and the transition surface 254 . The term “offset” is used to describe a bracket position on a surface of the tooth that is offset from the ideal position calculated by the computer aided planning system. As shown in FIG. 3A , the jig needed to place bracket A in the first offset position is configured to avoid a zone of overlap with adjacent teeth.
[0033] According to the defined treatment plan illustrated in FIG. 2 , the bracket B will then be placed at a second offset location on a plane of the tooth closer to the ideal position with bracket axis LB forming a second offset angle A 3 ′ (larger than the first acute angle) with respect to tooth axis L 2 . The second offset position has the bracket B positioned more facially with a portion of the pad bonded to the facial surface 250 and a portion bonded to the transition surface 254 . It will be appreciated that one or more rotational brackets can be used to move the tooth. Further, as illustrated, the centers of the transitional brackets A and B do not align with the center 260 of the facial surface 250 . As shown in FIG. 2 , the bracket 12 can later be positioned at the ideal position 260 to form a substantially perpendicular angle A 3 ″ with the axis L 2 .
[0034] Referring to FIGS. 3A and 3B , there is a shown a further portion of a transitional module according to another aspect of the present disclosure. More specifically, as is known with existing systems, custom designed transfer jigs 400 and 410 are provided to apply the ideal brackets I 1 and I 3 , respectively, to the designated teeth. As shown in FIG. 3A , a transitional transfer jig 420 is shown with the rotational bracket A positioned on tooth T 2 . The transfer jig 420 is oriented along the direction of arrow 480 with side walls 450 and 452 positioned at a non-orthogonal angle with respect to axis L 2 . As shown in FIG. 3B , the jig 420 extends across a trough 258 to span the tooth from the side surface 252 to the opposing side surface 253 . The jig 420 is maintained in position by the engagement of recesses 442 and 444 with tooth peaks 272 and 274 , respectively. In this position, a recessed sidewall portion 454 is positioned adjacent tooth T 1 and a front wall 456 is positioned generally facially. The engagement of the transitional jig 420 allows the rotational bracket A to be held in place in the position calculated by the computer aided treatment system as shown in FIG. 2 .
[0035] FIG. 4 illustrates the rotational bracket A offset position on tooth T 2 . The bracket A is interconnected with the brackets I 1 and I 3 via a wire W. The wire W is configured to partially rotate tooth T 2 . The remaining portions to the sequential treatment brackets B and I 2 are shown below T 2 and are retained by the orthodontist for later installation on the tooth.
[0036] Referring now to FIG. 5 , the bracket A is shown aligned along the wire W with the brackets I 1 and I 3 . Tooth T 2 has been rotated by an angle of A 1 from the initial position at L 2 to a first intermediate rotational position L 2 ′. In one embodiment, A 1 is in the range of approximately 15-30 degrees. Once the teeth positioning has progressed to the positions shown in FIG. 5 , the treatment plan may be continued with the second module of the transitional treatment plan.
[0037] Referring now to FIGS. 6A and 6B , the bracket A has been removed from tooth T 2 . The brackets I 1 and I 3 remain on teeth T 1 and T 3 , respectively. A second transitional transfer jig 600 is shown with the rotational bracket B positioned on tooth T 2 . The transfer jig 420 is oriented along the direction of arrow 680 with side walls 650 and 652 positioned at a non-orthogonal angle with respect to axis L 2 ′, although the angle of orientation is not less than the angle A 2 from FIG. 1 .
[0038] As shown in FIG. 6B , the jig 600 extends across the trough 258 to span the tooth T 2 from the side surface 252 to the opposing side surface 253 . The jig 600 is maintained in position by the engagement of the occlusal surfaces or recesses 642 and 644 with the occlusal tooth surfaces or tooth peaks 272 and 274 , respectively. In this position, a sidewall portion 654 is positioned adjacent tooth T 1 and a front wall 656 positioned generally facially with the bracket B contacting at least a portion of the facial surface 250 of tooth T 2 . The engagement of the transitional jig 600 allows the intermediate rotational bracket B to be held in place in the offset position calculated by the computer aided treatment system as shown in FIG. 2 . The intermediate rotational bracket B may be bonded to tooth T 2 in the offset position shown in FIGS. 6A and 6B .
[0039] FIG. 7 illustrates the intermediate rotational bracket B positioned on tooth T 2 . The bracket B is interconnected with the brackets I 1 and I 3 via the wire W. The wire W is configured to partially rotate tooth T 2 . The remaining portion of the sequential treatment system, the bracket I 2 , is shown below T 2 and is retained by the orthodontist for later installation on the tooth.
[0040] Referring now to FIG. 8 , the wire W has effected additional rotation of tooth T 2 through bracket B such that longitudinal axis L 2 ″ is now offset from the starting longitudinal axis L 2 by an angle of A 1 ′ (which is larger than the angle A 1 of FIG. 5 , but is still smaller than the original offset angle A 2 of FIG. 1 ).
[0041] Referring now to FIG. 9 , tooth T 2 has been rotated by the application of rotation module brackets A and B sufficiently to apply the ideal bracket 12 to the facial surface 250 of tooth T 2 in the calculated ideal position (e.g., position 260 shown in FIGS. 1-2 ). In other words, the tooth T 2 has been rotated sufficiently to reduce the interferences or areas of overlap enough to allow for the placement of the bracket 12 in the ideal position (e.g., position 260 shown in FIG. 1 ). As shown, the bracket 12 is positioned substantially in line with arrow 680 ′ which is substantially perpendicular to the axis L 2 ″ of tooth T 2 .
[0042] With reference to FIG. 10 , the wire W may not be interconnected with the brackets in a traditional fashion to complete the computer generated treatment plan.
[0043] As shown in FIG. 11 , upon completion of the treatment, the tooth T 2 has been rotated through an angle A 1 ″ substantially matching the original offset angle A 2 . Similarly, a longitudinal axis L 2 ′ of the tooth T 2 is generally aligned with the axis L 1 of tooth T 1 and the axis L 3 of tooth T 3 . While the illustrated embodiment is shown with substantially linearly aligned teeth for ease of illustration, it will be appreciated that teeth structures in the mouth vary and that often teeth are aligned along a curve or arc rather than in a pure linear fashion. The description of the alignment of teeth is illustrative, it being understood that the rotation of the intermediate tooth to affect the computer aided treatment plan allows final positioning of the teeth in the desired position.
[0044] Referring now to FIG. 12 , there is shown a treatment system kit 1200 according to another aspect of the present disclosure. More specifically, the treatment system kit 1200 includes a series of brackets and transfer jigs necessary to implement a traditional computer aided tooth correction plan. However, in the illustrated embodiment a cap 1210 covers one of the brackets and transfer jigs. The cap 1210 provides a visual indicator to the user that the underlying bracket and jig should not be used in the initial installation on the teeth. Instead, the user must first apply one or more sequential treatment modules to the tooth of interest before the final treatment bracket positioned under cap 1210 can be applied. As described above, the sequential treatment needed may be a derotation of a tooth, such that the cap is an indicator that rotation sequence has been engaged by the computer aided treatment plan.
[0045] Thus, FIG. 12 illustrates a computer designed orthodontic treatment system kit with user indication signaling the need for sequential treatment of at least one tooth. A sequential treatment module package 900 is shown positioned centrally in the packaging of the treatment system. As discussed above, the computer aided design system determines the treatment plan for movement of the teeth including whether any teeth need sequential treatment by one or more preliminary offset brackets before placement of the final, ideal brackets. In the pictured embodiment, the sequential treatment module package 900 includes a series of a sequential treatment modules 910 and 920 .
[0046] FIG. 13 illustrates an enlarged view of the package 900 having the series of sequential treatment modules 910 and 920 according to at least one aspect of the present disclosure. Although for some patients, only a single treatment module will be needed before sequentially applying the final treatment bracket, the illustrated version includes two pre-final, offset brackets A and B as previously described along with their associated transfer jigs. As set forth above, the brackets and transfer jigs of each module have been computer designed based on imaging of the teeth to provide a custom fit for the tooth at an initial offset starting position for the module 910 and at a calculated intermediate offset position for module 920 . In addition, since more than one treatment module is included in the sequential treatment system, a cover 930 is positioned over the intermediate module 920 to indicate to the user to apply the module 910 first and retain the module 920 for later application.
[0047] Although the sequential treatment module package 900 is shown positioned within the packaging of the ideal bracket system, it will be appreciated that the modules may be packaged completely separately. In addition, it is contemplated that in an alternative form, the position of the tooth needing sequential treatment may have a layered packaging system such that the user peels away layers to expose the next bracket and jig module needed to affect the desired treatment. Still further, while the description is in relation to derotation of a tooth, it will be appreciated that the description is not limited to any particular tooth misalignment and the general concepts disclosed herein can be applied to other misalignments including partially erupted teeth, baby teeth, and overlapped starting alignments of adjacent teeth or interference between top and bottom teeth.
[0048] Referring now to FIG. 14 , there is shown a block diagram of an implementation flow diagram 1400 of how the sequential treatment system may be implemented in at least one embodiment. The following description is made in relation to enhancement of existing computer aided treatment systems such as described above and incorporated by reference herein. At step 1402 , a computer system receives digitized information representative of the initial tooth positions within the mouth. Often, this information is obtained via a scan of the mouth, although other forms of obtaining such information are contemplated. The computer system then determines the desired final tooth positions at step 1404 . At step 1406 , the computer system determines the plan for moving each tooth from the initial position to the final position. As part of this determination, the system determines the type of ideal bracket needed for each tooth, its ideal bonding location on the tooth and the shape of a transfer jig necessary to align the bracket with the desired position on the tooth. At step 1408 , the system then determines if there are any interferences between the teeth, gums, ideal brackets, jigs or wires at any point during the treatment path. If there are no interferences identified, then the system moves on to sending instructions for manufacturing the custom components in step 1430 . If interferences are detected at step 1408 , then the system alerts the user at step 1410 and asks whether the system should implement sequential treatment modules to address the identified interferences. The system may be configured such that the system always performs the sequential module without waiting for user input. In the illustrated embodiment, at step 1410 the user indicates whether a computer aided sequential module should be initiated. If no, the system moves to step 1430 . If yes, the system moves to step 1420 and generates the necessary sequential treatment modules needed to move at least one tooth into position to receive the ideal bracket system previously identified at step 1406 . Although not illustrated, it will be appreciated that the user can approve or reject computer aided design options for the sequential modules and may have access to modify the proposed sequential modules.
[0049] Once the sequential treatment modules have been developed, the computer system next determines the package layout or configuration at step 1422 such that the manufacturing portion of the system will provide the sequential treatment system in a unique form to the end user, such as an orthodontist, in a manner that will alert the user to the existence of at least two treatment brackets for a single tooth. The computer aided designs along with packaging information are then forwarded, typically by sending electronic data, at step 1430 to the manufacturing system. The components of the system are selected from inventory or custom manufactured as necessary and then packaged in step 1440 according to the packaging instructions. The complete sequential treatment system, including sequential modules, may then be shipped to the end user at step 1450 . In an alternative form, only the brackets and jigs needed for the initial installation are shipped initially with the sequential brackets following separately based on the timing determined by the computer aided treatment plan.
[0050] Persons of ordinary skill in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the particular exemplary embodiments described above. In that regard, although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the present disclosure.
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A system providing transitional bracket and transfer jig modules that have been custom designed to address a rotated or partially erupted tooth in advance of applying a computer aided bracketing system to the tooth. The transfer jigs and brackets are used until the problem tooth is moved into a position that will allow positioning of the “ideal” bracket. Once the ideal brackets are position, the treatment plan can proceed as it would with existing systems to reach the final ideal position. The transitional modules are integrated into the customized treatment plan such that the orthodontist just follows the digitized plan, including correction of misaligned teeth. The computer system that assists with defining the treatment plan takes into account the starting position of the teeth and can adjust the plan, as well as use of transitional brackets, to accommodate many more patients that have one or more problem teeth needing correction.
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FIELD OF THE INVENTION
The invention relates to positioning fences for lumber or timber in sawmills or planermills and methods of using the positioning fences.
BACKGROUND OF THE INVENTION
In sawmills, various lumber or timber handling machinery is provided to cut and shape the lumber or timber into saleable wood products. One of the required operations in a mill, after sawing or forming to the desired cross section, is end trimming individual boards or timbers to a specified length. The term “sawmills” includes planermills.
To cut the material to length, a typical arrangement of transport equipment has a conveyor that has a lug chain table to transport the lumber pieces to length cutting saws. The lumber pieces are carried along the conveyor in equidistantly spaced succession based on the lug spacing of the lug chains. The conveyor has a set of lateral alignment rollers. The lateral alignment rollers form a roller bed system placed at right angles to the lug chain, which operate to urge one end of the lumber material toward a stop or fence, also referred to as a paddle. In this arrangement, each successive piece of lumber is spaced from the other in the direction of travel along the lumber conveyor by the lugs of the lug chain and one of the ends of the lumber is laterally aligned to the stop or fence.
The piece to be cut to length is positioned for contact with a saw or series of saws. In the configuration of sawmill conveyor equipment just described, the saws are stationary relative to the conveyor and the board is laterally positioned on the conveyor relative to the saw blade. A positioning fence, which one end of the lumber piece abuts against, controls the lateral position of the lumber piece on the feed conveyor. Numerous prior art arrangements for adjustable positioning fences for use with such a feed conveyor arrangement have been proposed in the past. For example a step positioning fence is disclosed in the published Canadian Patent application 2,241,481 of Wight et al. The stepped positioning fence of Wight has a plurality of rigid elevated faces, or steps that extend longitudinally along a side of the fence in an adjacent stepped array of differing offset spacing. The fence is oriented to present one of the steps for contact with the lumber piece to align the lumber end to the corresponding offset of that step. The lumber is urged into contact with the fence by the lateral alignment rollers resulting in alignment of the lumber end to the fence step offset. The stepped fence provides fixed incremental ending settings and a positioning mechanism to ensure the board is presented with a step suitable to obtain the desired or intended lateral translation of the board piece.
Another flexible trimmer position fence is disclosed in Canadian Patent 2,191,390 to Jackson, which discloses a board positioning fence comprised of a plurality of adjustable fence elements each staged one after the other in the downstream direction of travel of the lumber to be positioned. The lumber is urged against the positioning fence by lateral alignment or ending rollers. The ending rollers urge the lumber laterally across the feed conveyor into contact with the successive fence elements of the board positioning fence. When the desired lateral positioning of the board is achieved, lift skids are engaged to remove the lumber from contact with the lateral urging end rollers. This arrangement has multiple flexible fence elements, which are adjusted to allow the board to be ended to the desired positioning or ending location. Once the board has been displaced laterally to the desired position offset, skids are engaged that lift the positioned lumber piece away from the ending rollers.
Another arrangement to provide board lumber end positioning is disclosed in the Canadian patent 2,236,508 of Hannebauer et al. Hannebauer discloses a circulating paddle positioning fence with a flexible guide track. Actuators position the flexible guide track, which results in corresponding positioning of a paddle to a desired offset or ending position.
And yet another positioning mechanism is disclosed in the published Canadian Patent application 2,345,872 of Jobin, for apparatus for positioning pieces of wood for precise cutting. Jobin discloses an adjustable barrier, which is provided with actuators to position the barrier to the desired offset location. Various forms of adjustable barriers are shown including ones which have a face that remains perpendicular to the board as well as providing for incline planes that have a set displacement selected by an actuator to achieve an ending or offset of the lumber laterally to the desired offset amount.
A further positioning mechanism is disclosed in U.S. Pat. No. 7,419,047. This patent discloses a continuous moving track loop having a plurality of paddles laterally positionable across the width of the track. Complex mechanical brake mechanisms, positioning cams and reset cams are used to position the paddles.
It is very difficult to accurately position the paddles on the track and often the paddles are not locked at the desired location. There is a need for a device which checks the locked paddle position and adjusts the final locked paddle position.
SUMMARY OF THE INVENTION
An objective of the invention is to provide a device which checks the locked paddle position and then adjusts the locked paddle position by moving the track if the paddle is not locked in the desired position.
Another objective of the invention is to provide a device in which the paddle is locked in a rough position and the final position of the locked paddle is performed by moving the track if the locked paddle is not in the desired position.
A further objective of the invention is provide an infinite number positions for the locked paddle.
Another objective is to provide an apparatus for retrofitting conventional position fences to provide a greater accuracy of the final locked paddle position.
The invention relates to an apparatus for positioning a lumber piece comprising:
a continuous track loop having an in-feed end and an out-feed end; a plurality of paddles spacedly disposed along the length of the continuous track loop, at least one paddle slideably mounted along a bearing way coupled to the track loop so that the paddle is laterally displaceable across a width of the track loop, and wherein the paddle comprises a lumber surface for contacting a surface of the lumber piece and stopping the lumber piece in a desired position perpendicular to a longitudinal direction of the track loop during use; a paddle locking mechanism constructed to lock the paddle in a desired position on the bearing way; a paddle moving device constructed to place the paddle in a desired position where the paddle is locked in position on the bearing way by the paddle locking mechanism; a paddle position sensor constructed to measure the position of the locked paddle; a track moving device constructed to move at least the out-feed end of the track in a lateral direction; and a controller connected to the paddle position sensor and track moving device, the controller constructed to compare the measured position of the locked paddle to the desired position of the locked paddle and if the measured position of the locked paddle is other than the desired position the controller is constructed to activate the track moving device to move at least the out-feed end of the track so that the locked paddle is placed in the desired position.
The invention also relates to a method for positioning a lumber piece using an apparatus comprising:
a continuous track loop having an in-feed end and an out-feed end; a plurality of paddles spacedly disposed along the length of the continuous track loop, at least one paddle slideably mounted along a bearing way coupled to the track loop so that the paddle is laterally displaceable across a width of the track loop, and wherein the paddle comprises a lumber surface for contacting a surface of the lumber piece and stopping the lumber piece within 5 inches of a desired position perpendicular to a longitudinal direction of the track loop during use; a paddle locking mechanism constructed to lock the paddle on the bearing way; a paddle moving device constructed to place the paddle within 5 inches of a desired position where the paddle is locked in position on the bearing way by the paddle locking mechanism; a paddle position sensor constructed to measure the position of the locked paddle; a track moving device constructed to move at least the out-feed end of the track in a lateral direction; and a controller connected to the paddle position sensor and track moving device, the controller constructed to compare the measured position of the locked paddle to the desired position of the locked paddle and if the measured position of the locked paddle is other than the desired position the controller is constructed to activate the track moving device to move at least the out-feed end of the track so that the locked paddle is placed in the desired position, the method comprising; operating the track; moving a paddle to a desired position on the bearing way; locking the paddle in position on the bearing way using the paddle locking mechanism; measuring the position of the locked paddle using the paddle position sensor; comparing the position of the locked paddle to the desired position of the paddle using the controller; and if the position of the locked paddle is different from the desired position, activating the track moving device to move at least the out-feed of the track in a lateral direction and move the locked paddle to the desired position.
The invention further relates to retrofit position fence table comprising:
a table top sized and constructed to mount a position fence on top of the table top, the table top having an in-feed end and an out-feed end which correspond to an in-feed end and an out-feed end of a position fence when mounted on the table top; a table base, the table top being mounted to the table base so that at least the out-feed end of the table top is moveable in a lateral direction; a track moving device constructed to move at least an least the out-feed end of the table top in a lateral direction; a paddle position sensor constructed to measure a position of a locked paddle when a position fence is mounted on the table top; and a controller connected to the paddle position sensor and track moving device, the controller constructed to compare the measured position of the locked paddle to the desired position of the locked paddle and if the measured position of the locked paddle is other than the desired position the controller is constructed to activate the track moving device to move at least the out-feed end of the table top so that the locked paddle is placed in the desired position.
The invention also relates to a method for positioning a lumber piece using an apparatus comprising:
a position fence comprising;
a continuous track loop having an in-feed end and an out-feed end; a plurality of paddles spacedly disposed along the length of the continuous track loop, at least one paddle slideably mounted along a bearing way coupled to the track loop so that the paddle is laterally displaceable across a width of the track loop, and wherein the paddle comprises a lumber surface for contacting a surface of the lumber piece and stopping the lumber piece in a desired position perpendicular to a longitudinal direction of the track loop during use; a paddle locking mechanism constructed to lock the paddle in a desired position on the bearing way; and a paddle moving device constructed to place the paddle in a desired position where the paddle is locked in position on the bearing way by the paddle locking mechanism; and
a retrofit position table comprising:
a paddle position sensor constructed to measure the position of the locked paddle; a table top having the position fence mounted thereon, the table top having an in-feed end and an out-feed end which correspond to the in-feed end and the out-feed end of a position fence; a table base, the table top being mounted to the table base so that at least the out-feed end of the table top is moveable in a lateral direction; a track moving device constructed to move at least an least the out-feed end of the table top and out-feed end of the track in a lateral direction; and a controller connected to the paddle position sensor and track moving device, the controller constructed to compare the measured position of the locked paddle to the desired position of the locked paddle and if the measured position of the locked paddle is other than the desired position the controller is constructed to activate the track moving device to move at least the out-feed end of the table top and track so that the locked paddle is placed in the desired position, the method comprising;
operating the track; moving a paddle to a desired position on the bearing way; locking the paddle in position on the bearing way using the paddle locking mechanism; measuring the position of the locked paddle using the paddle position sensor; comparing the position of the locked paddle to the desired position of the paddle using the controller; and if the position of the locked paddle is different from the desired position, activating the track moving device to move at least the out-feed end of the table top and the out-feed end of the track in a lateral direction and move the locked paddle to the desired position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of an embodiment of the positioning fence;
FIG. 2 is a top view of an embodiment of the positioning fence;
FIG. 3 is a side view of the positioning fence of FIG. 1 ;
FIG. 4 is a side view of the positioning fence of FIG. 2 ;
FIG. 5 is a side view of an embodiment of the retrofit positioning fence table;
FIG. 6 is side view of an embodiment of the retrofit positioning fence table;
FIG. 7 is a side view of a positioning fence mounted on top of a the retrofit positioning fence of FIG. 6 ;
FIG. 8 is a top view of the retrofit positioning fence table of FIG. 5 ;
FIG. 9 is a top view of the retrofit positioning fence table of FIG. 6 .
DETAILED DESCRIPTION
The inventions will now be explained with reference to the non-limiting Figures.
FIGS. 1 and 2 show embodiments of the positioning fence of the present invention. Positioning fences are now well known and any positioning fence can be modified according to the present invention. Suitable examples of positioning fences are disclosed in Canadian Patent Application Nos. 2,191,390; 2,236,508; 2,241,481; and 2,345,872; and U.S. Pat. No. 7,419,047, the complete disclosures of which are incorporated herein by reference. A preferred positioning fence is shown in my U.S. patent application Ser. No. 12/781,845, filed 18 May 2010, the complete disclosure of which is incorporated herein by reference.
The positioning fence is generally depicted by reference numeral 10 . The positioning fence has a continuous loop track 16 extending between an opposed set of end rollers (not shown). The width of the track 16 is generally about 3 feet, but any desired width can be used. The top of the track 16 moves in a left to right direction, as shown by the arrow A. The track 16 includes a plurality of paddles 18 spaced along the continuous track 16 corresponding to the lumber spacing of the individual lumber pieces that the lumber position fence will be used to position. The paddles 18 have a surface 19 for interacting with the lumber pieces 14 .
At least one of end rollers is driven to cause the track 16 and the paddles 18 to move in a longitudinal direction, that is in the direction of travel of the lumber 14 , which is generally depicted by arrow A. An end roller can be driven by and in time with the lumber conveyor or by a separate drive that follows the movement of the lumber conveyor exactly. At least one of the paddles 18 is mounted for lateral sliding movement across the width of the track loop along a bearing way 20 . The bearing way 20 is oriented for lateral movement of the paddle 18 , which is a direction perpendicular to the longitudinal direction of the track 16 .
The paddle 18 has a paddle locking mechanism 22 constructed and arranged to lock the lateral position of the at least one paddle. The paddle locking mechanism 22 can comprise any suitable locking mechanism. Preferably, the locking mechanism uses detents and a pin, as described in my U.S. patent application Ser. No. 12/781,845, filed 18 May 2010. Without the claimed invention, the preferred distance between detents was about 0.5 inch apart. However, with the claimed invention, the preferred distance between detents is greater than 1 inch and less than 3 inches, more preferably from 1 to 2 inches. With the present invention, the paddle 18 can be locked at a rough position, usually within 1 inch of the desired position. If the locked position is not the desired position, the present invention moves the locked paddle 18 to the desired position. Furthermore, conventional position fences 10 are limited to locked paddle 18 positions at the detents, while the present invention allows an infinite number of positions for the locked paddle 18 .
As the detents become closer together, the accuracy of stopping the paddle locking mechanism 22 in the correct detent so that the locked paddle 18 is in the desired location becomes more difficult. Furthermore, if there is no detent at the desired position, the paddle 18 cannot be locked in the desired position. Moreover, when locking mechanisms 22 rely upon other methods to secure the location of the locked paddle 18 , such as by friction, the paddle 18 often is not locked in the desired position. The present invention solves this problem by adding a final adjustment to the paddle 18 after the locking mechanism 22 locks the paddle in position on the bearing way 22 . Thus, the present invention can be used to retrofit existing position fences 10 .
The present invention incorporates a track moving device 32 , such as a hydraulic, electric or pneumatic actuator, or other motorized device, which moves at least the out-feed end of the track 16 in a lateral direction shown by the arrows B. The track moving device 32 preferably includes a feedback device 33 that confirms the location of the track 16 or the table top 50 . While any feedback device 33 can be used, the feedback device 33 can be for example a transducer or an encoder. Commercial examples of a track moving device 32 having a feedback device 33 includes any of the electric Moog linear motors, disclosed at www.calinear.com. A commercial example of a transducer type of feedback device 33 is the MTS temposonic transducer, disclosed at http://www.acshydraulics.com/temposonic.html. Hydraulic or pneumatic actuators can be used in conjunction with a servo or proportional valve to control the speed and position of the cylinder. The feedback device 33 is connected to the controller 34 .
In FIGS. 1 and 3 , the track 16 is mounted on the in-feed end using a pivot 40 and a movable base 42 on the out-feed end. In this manner, when the track moving device 32 is activated, the out-feed end of the track 16 rotates about the pivot 40 , which includes a lateral movement component, and thus the out-feed end of the track 16 moves laterally in either of the directions shown by the arrows B. The movable base 42 can be any as desired, such as wheels or slides. In this embodiment, preferably the movable base 42 uses wheels. For example, the wheels can be flat or mounted on tracks in an arc about the pivot point.
In FIGS. 2 and 4 , the track 16 is mounted on a movable base 44 so that both the in-feed and out-feed ends of the track 16 move laterally as shown by the arrows B. The movable base 44 can be any as desired, such as wheels, slides, or bearings. The wheels can be flat, curved, or on tracks, such as a v-track. In this embodiment, preferably the movable base 44 uses slides. The movable base 44 preferably also includes an optional rack-and-pinion 58 so that both ends of the track 16 move at the same time no matter where the track moving device 32 is mounted. The optional rack-and-pinion 58 is described with reference to FIG. 5 below, with the rack-and-pinion 58 being connected between the track 16 and the floor, such as by a metal plate 52 mounted on the floor.
Preferably, the track moving device 32 is capable of moving the track 16 at least 0.1 inch in either direction shown by the arrows B, more preferably up to 3 inches, and even more preferably up to 1 inch. In most cases, the track 16 will be moved in either of the lateral directions shown by the arrows B by 0.75 inch or less.
In the present invention, a paddle position sensor 30 , such as a laser sensor, is located on the out-feed side of the track 16 and is used to determine the actual position of the locked paddle 18 . A programmable computer controller 34 is used to control the operation of the paddles 18 and is connected to the paddle position sensor 30 and track moving device 32 . A commercial example of the programmable computer controller 34 is an A.B. ControLogix 5000 series. However, any suitable controller 34 can be used. With the addition of a paddle position sensor 30 connected to the controller 34 , the exact location of the locked paddle 18 can be determined and compared to the desired position. If the locked paddle 18 is not in the desired position, the controller 34 is constructed to activate the track moving device 32 and move the track 16 in a lateral direction so that the locked paddle 18 is located in the desired position without unlocking the paddle 18 .
The invention also includes a retrofit position fence table 48 as shown in FIGS. 5-9 . The retrofit position fence table 48 includes a table top 50 and table base 52 . The table top 50 is sized and constructed to have a position fence 10 mounted thereon, as shown in FIG. 7 . In this manner, conventional position fences 10 can be easily upgraded to practice the present invention.
An embodiment of the retrofit position fence table 48 is shown in FIG. 5 . The table top 50 is mounted on the table bottom 52 by a movable base 44 so that both the in-feed and out-feed ends of the table top 50 move laterally, as shown by the arrows B in FIG. 9 . The movable base 44 can be any as desired, such as wheels, slides, or bearings. The wheels can be flat, curved, or on tracks, such as a v-track. In this embodiment, preferably the movable base 44 uses slides. The movable base 44 preferably also includes an optional rack-and-pinion 58 so that both ends of the table top 50 , and when the position fence 10 is mounted on the table top 50 , both ends of the track 16 move at the same time no matter where the track moving device 32 is mounted. The rack-and-pinion 58 includes racks 60 mounted to opposite ends of the table top 50 , gears 62 engaged with the racks 60 , and the gears 62 being connected by an equalizer shaft 64 .
Another embodiment of the retrofit position fence table 48 is shown in FIG. 6 . The table top 50 is mounted to the table bottom 52 by a pivot 40 on the in-feed end and a movable base 42 on the out-feed end. A track moving device 32 is connected to the table top 50 . In this manner, when the track moving device 32 is activated and a position fence 10 is mounted on the table top 50 , the out-feed end of the table top 50 rotates about the pivot 40 , which includes a lateral movement component, and thus the out-feed end of the table top 50 moves laterally in either of the directions shown by the arrows B, as shown in FIG. 8 . Thus, when a position fence 10 is mounted on the retrofit position fence table 48 , the out-feed end of the track 16 moves laterally, as shown by the arrows B, when the track moving device 32 is activated. The movable base 42 can be any as desired, such as wheels or slides. In this embodiment, preferably the movable base 42 uses wheels. For example, the wheels can be flat or on tracks mounted in an arc about the pivot point.
The invention also relates to a method of locating a piece of lumber 14 on a conveyor that is transporting the lumber with one end of the lumber contacting the surface 19 of the paddle 18 . During use, a piece of lumber 14 being transported on the conveyor is urged toward the paddle 18 traveling on track 16 . The paddle 18 prevents further movement of the lumber in a direction perpendicular to the travel of the track 16 when the locking mechanism 22 is switched to a closed position which locks the paddle 18 in place on the bearing way 20 . The paddle position sensor 30 determines the location of the locked paddle 18 and sends the information to the controller 34 . The location of the locked paddle 18 is compared to the desired location and if the location of the locked paddle 18 is not at the desired position, the track moving device 32 is activated to move the track 16 in a lateral direction so that the locked paddle 18 is located in the desired position without unlocking the paddle 18 . The position of the track 16 is confirmed by the feedback device 33 . Once the locked paddle 18 is in the desired position, the lumber 14 urged against the surface 19 of the locked paddle 18 will be in the desired position. The lumber 14 will continue to be transferred downstream to a trimmer where the lumber can be cut to size. After the lumber has exited the track 16 , the paddle 18 is returned to a starting position.
In another embodiment of the method, the retrofit position fence table 48 is utilized, with a position fence 10 mounted on the table top 50 . During use, a piece of lumber 14 being transported on the conveyor is urged toward the paddle 18 traveling on track 16 . The paddle 18 prevents further movement of the lumber in a direction perpendicular to the travel of the track 16 when the locking mechanism 22 is switched to a closed position which locks the paddle 18 in place on the bearing way 20 . The paddle position sensor 30 determines the location of the locked paddle 18 and sends the information to the controller 34 . The location of the locked paddle 18 is compared to the desired location and if the location of the locked paddle 18 is not at the desired position, the track moving device 32 is activated to move the table top 50 and track 16 in a lateral direction so that the locked paddle 18 is located in the desired position without unlocking the paddle 18 . The position of the table top 50 or track 16 is confirmed using the feedback device 33 . Once the locked paddle 18 is in the desired position, the lumber 14 urged against the surface 19 of the locked paddle 18 will be in the desired position. The lumber 14 will continue to be transferred downstream to a trimmer where the lumber can be cut to size. After the lumber has exited the track 16 , the paddle 18 is returned to a starting position.
While the claimed invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one of ordinary skill in the art that various changes and modifications can be made to the claimed invention without departing from the spirit and scope thereof.
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Provided is a positioning fence for use in lumber sawmills and method of using the positioning fence that facilitates automated positioning of lumber for cutting and a method of positioning lumber for cutting. Also provided is a retrofit position fence table and a method of using the retrofit position fence table. A continuous moving track loop has a plurality of paddles laterally positionable across the width of the track. A track moving device is used to adjust the final locked position of the paddles if the paddles are not locked in the desired position.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 09/198,752, filed Nov. 24, 1998 and entitled “Biogas Flaring Unit” and claims priority therefrom. Application Ser. No. 09/198,752 is incorporated herein in its entirety.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
This invention relates to a system for flaring biogas generated by landfill sites or waste water facilities, and, more particularly, to a system that decreases harmful combustion products.
In landfills and waste water treatment, oftentimes it is necessary to dispose of waste gases, such as methane, generated by the disposal and decay of biological products. Flaring systems are used to burn off or combust such biogases to prevent environmental, explosion, and worker safety hazards. Various flare units are utilized to combust the biogas. Assignee of this application manufactured a unit having a stack with a plurality of burners located therein. The burners are fed via a supply line containing biogas. The biogas is fed directly to the burners without any premixture of air. The tip of each of the burners is disposed in an aperture formed in a false bottom within a stack. The false bottom is insulated with refractory or other suitable heat-resistant material to ensure that excess heat generated by flames extending from the burner tip is not transferred to the burner manifold located below the false bottom within the stack. An annular gap exists between the burner tip and the aperture formed in the false bottom. Air from a chamber below the false bottom flows upwardly through these annular gaps and is utilized to accomplish the combustion of the biogas exiting the burner tip, and further to potentially quench the temperature in the stack if necessary to reduce and control the heat generated within the stack. The air is drawn into the chamber below the false bottom via dampers positioned in the outer wall of the stack. The dampers can be actuated to control the combustion and quench air that flows to the flame via the annular apertures in the false bottom.
This biogas flaring system suffers from various disadvantages. First, it is difficult to finely adjust the amount of combustion air utilized in the process by utilizing the air delivery structures of the prior art system. More specifically, a correct premixture of air and fuel, prior to combustion, can reduce the emissions of various harmful gases, such as nitric/nitrous oxide (NOx) and carbon monoxide (CO). The prior air supply structures do not allow a proper premixing of air with fuel prior to combustion. Further, if the biogas must seek combustion air within the stack, flames will often extend upwardly from the burner tip to substantial heights, thus requiring a substantial height of the stack to conceal the flames.
In prior systems, each flame generated by a burner tip is generally unrestricted after it exits the burner tip, and oftentimes flows in a nonturbulent manner. This type of flame structure can result in an unstable flare system which can generate a significant amount of combustion instability noise. Added to the noise generated by combustion instability is the noise of the quench air flowing through the blades of the dampers located in the stack wall of the prior art system.
Therefore, a flaring system is needed which alleviates the problems of the prior art discussed above.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a flaring system that reduces the emission of nitric oxide.
It is a further object of the present invention to provide a flaring system which reduces the emission of carbon monoxide even at lower combustion temperatures.
A still further object of the present invention is to provide a flaring system that decreases the flame length to decrease the size of stack required.
Another object of the present invention is to provide a flaring system that reduces noise resulting from combustion and noise resulting from air flowing across the damper blades and into the stack.
Yet another object of the present invention is to provide a flaring system that increases flame temperature resulting in an increase in destruction efficiency in unburned hydrocarbons.
Accordingly, the present invention provides for at least one burner for igniting a mixture of biogas and air. A main supply line supplies the mixture to the burner. A biogas supply line feeds into the main supply line. An air supply line also feeds into the main supply line. A mixer structure is utilized to ensure that the biogas and air are mixed prior to being supplied to the burner.
The invention also provides for a flame stability device for use in conjunction with the burner. The device includes an enclosure generally surrounding and extending upwardly from a burner tip. The enclosure has an inner surface that is exposed to a flame generated from the burner tip. A stability surface extends generally from the inner surface to the burner tip. The stability surface surrounds the burner tip and creates a turbulent zone also surrounding the burner tip. The flame generated by the burner tip reattaches to the inner surface above the stability surface.
The invention further provides for an ignition arrangement for a plurality of burners. The arrangement includes at least one enclosure surrounding one of the burners and extending upwardly from the burner tip. A pilot is used to ignite the enclosed burner. An ignition port extends from the enclosed burner to at least one adjacent burner such that when the pilot lights the enclosed burner, combustion gases from the enclosed burner travel through the ignition port to ignite the adjacent burner.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which form a part of this specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:
FIG. 1 . is a side elevational view of a biogas flare system embodying the principles of this invention, parts being broken away and shown in cross section to reveal details of construction;
FIG. 2 is a cross-sectional view taken generally along line 2 — 2 of FIG. 1 and showing the arrangement of a plurality of burners utilized in the flaring system of the present invention;
FIG. 3 is an enlarged view of a portion of the central area in FIG. 2, and showing the ignition ports extending from a main burner to adjacent burners;
FIG. 4 is a cross-sectional view taken generally along line 4 — 4 of FIG. 3 and showing a flame stability device associated with a burner; and
FIG. 5 is a top perspective view of two flame stability devices according to the present invention shown installed on two adjacent burners;
FIG. 6 is a graph depicting experimental results at a biogas (or fuel) flow rate of 1,500 standard cubic feet per minute (scfm) for a particular gas makeup;
FIG. 7 is a graph depicting experimental results at a flow rate of 500 scfm for the same gas as in FIG. 6;
FIG. 8 is a graph depicting experimental results at a flow rate of 500 scfm for a different gas makeup;
FIG. 9 is a graph depicting experimental results at a flow rate of 1,000 scfm for a still further gas makeup; and
FIG. 10 is a graph depicting experimental results at a flow rate of 500 scfm for the same gas as in FIG. 9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in greater detail, and initially to FIGS. 1-3, a biogas flaring system designated by the reference numeral 10 as shown. System 10 includes a biogas supply line 12 and an air supply line 14 , which feed into a main supply line 16 . Biogas in supply line 12 is introduced into the line from the landfill or waste water site where it has been collected utilizing methods and structures well known in the art. Air is introduced into supply line 14 via use of a variable speed fan 18 shown diagrammatically in FIG. 1 . After air and biogas are introduced into main supply line 16 , they are forced through a static mixer 20 disposed in line 16 . Mixer 20 typically is of a corrugated plate variety and ensures adequate interaction between the biogas and air. One type of static mixer that has been found suitable is a mixer identified by the model number SMF-LF, manufactured by Koch Engineering Company, Inc., of Wichita, Kans.
The amount of air and biogas entering main supply line 16 from supply lines 12 and 14 is controlled by a controller 22 . More specifically, controller 22 can actuate and control variable speed fan 18 and also possibly a variable speed fan (not shown) or valve coupled to line 12 in a manner well-known in the art. Controller 22 can be utilized to adjust the ratio of biogas to air, as will be more fully described below. One suitable type of controller for adjusting the biogas/air ratio is identified by the model number TSX 3721001, manufactured by Modicon of Palatine, Ill.
After gas exits mixer 20 , it flows to a burner manifold 24 disposed in a generally cylindrical shell or stack 26 . Stack 26 has an open top where combustion gases generated in the stack are emitted into the environment. Located adjacent the lower end of stack 26 is a plurality of motorized dampers 28 . Dampers 28 are of a construction well-known in the art and are utilized to supply quench air to stack 26 , as will be more fully described below. Additionally, dampers 28 can also be electrically controlled by controller 22 . A suitable construction for dampers 28 can include a plurality of mutually actuated blades, or further, a single blade-type actuation mechanism.
Extending upwardly from burner manifold 24 is either one or a plurality of burners 30 and 32 . More specifically, the burners are arranged in a pattern such that there is a central burner 30 and secondary burners 32 disposed and generally surrounding central burner 30 , as best shown in FIGS. 2, 3 , and 5 . The mixture of air and biogas supplied to manifold 24 is equally divided and supplied to burners 30 and 32 .
With reference to FIG. 4, each burner includes a burner tip 34 to which the biogas/air mixture is supplied and from which a flame extends upwardly. Associated with each burner tip is a generally cylindrical flame stability device or tile 36 . Stability devices 36 generally surround burner tips 34 and extend upwardly therefrom. Each device 36 has a generally annular primary stability surface 38 , an intermediate generally annular ridge 40 extending inwardly from an inner surface 42 of device 36 , and a top generally annular lip 44 extending inwardly from inner surface 42 . Ridge or ring 40 forms a generally annular primary retention surface 46 on its lower end, and a generally annular secondary stability surface 48 on its upper end. Additionally, lip 44 forms a generally annular secondary retention surface 50 adjacent its lower surface.
Primary stability surface 38 and primary retention surface 46 cooperate with inner surface 42 to form a generally cylindrical primary stability zone 52 . Secondary stability surface 48 and secondary retention surface 50 cooperate with inner surface 42 to form a secondary stability zone 54 . The purpose of annular surfaces 38 , 46 , 48 , and 50 and zones 52 and 54 will be more fully described below. Stability devices 36 can be made of any suitable heat-resistant material, for instance, a ceramic refractory, or high grade stainless steel. One such suitable material is identified by the trademark THERMBOND®, available from John Zink Company (a division of Koch-Glitsch, Inc.), of Tulsa, Okla.
With reference to FIGS. 2 through 5, central burner 30 has a plurality of ignition ports 56 extending from its stability device 36 to the stability devices 36 of secondary burners 32 . Ignition ports 56 are in the form of tubes, which can be made of the same material as devices 36 . Each tube 56 defines an inner bore 60 which serves to spatially connect central burner 30 with each of secondary burners 32 . Ports 56 are utilized to light secondary burners 32 after central burner 30 has been lit. More specifically, combustion gases in central burner 30 flow through bore 60 to ignite the adjacent burners, as will be more fully described below. Central burner 30 is lit utilizing a pilot assembly 62 which can be actuated externally of shell 26 . Again, controller 22 can be utilized to automatically actuate pilot assembly 62 , in a manner as is well-known in the art.
In operation, the premixing of the biogas with air in mixer 20 provides a significant advantage over prior art flare systems. More specifically, it has been found that the premixing of biogas and air prior to ignition in a burner can significantly reduce the nitric oxide and carbon monoxide emissions. More specifically, experimental data has shown that a primary air/fuel mixture can reduce nitric oxide by a factor of five to ten when compared with a conventional raw gas landfill flare. Additionally, typically carbon monoxide emissions dramatically increase as the temperature inside a conventional biogas flare decreases below approximately 1500° F. Premixing can allow the carbon monoxide emissions to remain very low, even if the temperatures in the stack decrease below 1500° F. The proper ratio of biogas to air is governed by controller 22 and is dependent upon the makeup of the biogas being flared. FIGS. 6-10 reflect experimental emissions data of the invention for various flow rates of various biogas/air mixtures for various compositions of gas compared to a standard prior art nonpremix burner. In the figures:
NOx
=
nitric oxide
CO
=
carbon monoxide
EA
=
excess air
TNG
=
Tulsa Natural Gas (93.4%-CH 4 ; 2.7%-C 2 H 6 ; 0.6%-
C 3 H 8 ; 0.2%-C 4 H 10 ; 2.4%-N 2 ; 0.7%-CO 2 )
CO 2
=
carbon dioxide
Std. burner
=
prior nonpremix burner
Generally, it is advantageous to have a ratio of biogas to air that has approximately 20% or greater excess air; further, a range of 20% to 50% excess air is preferable. Controller 22 is utilized in a manner well-known in the art to accomplish these ratios. It has also been found that premixing of air with biogas prior to combustion substantially reduces the soot formation in the flame resulting in a flame with a lower radiant fraction.
The premixing has been found to decrease the flame height within the stack by approximately thirty to fifty percent (30%-50%) as compared with conventional biogas flare systems.
Stability devices or tiles 36 are utilized to aid ignition of the system and provide flame stability. Devices 36 also reduce noise by blocking or shielding the combustion noise. More specifically, with reference to FIG. 4, stability zones 52 and 54 create generally annular turbulent areas 66 at locations surrounding burner flame 68 . These turbulent areas 66 increase the turbulent burning velocity, thus increasing the stability of the flame. In order to maximize the turbulence and hence flame stability within areas 66 , it has been found advantageous to have the width w P and w s of primary and secondary stability surfaces 38 and 48 designed such that the reattachment of the flame occurs near locations 70 and 72 which are below the locations of primary and secondary retention surfaces 46 and 50 , respectively, as best shown in FIG. 4 . It has been found advantageous to have the height h P of primary stability zone approximately seven to ten times the width w P of primary stability surface 38 . Further, it has been found advantageous to have the height h s of secondary stability zone 54 seven to ten times the width w s of secondary stability surface 48 . The ratios of these dimensions tend to allow the re-attachment of the flame prior to the primary and secondary retention surfaces 46 and 50 . Preferably, a positive pressure is maintained in the primary stability zone 52 . The positive pressure in primary stability zone 52 operates to force combustion gases through ignition ports 56 to light secondary burners 32 . More specifically, once central burner 30 is lit utilizing pilot assembly 62 , the positive pressure within primary stability zone 52 forces hot combustion gases from central burner 30 through ignition ports 56 to ignite biogas/air mixtures flowing through secondary burners 32 . In this manner, each of secondary burners 32 can be easily lit simply by lighting central burner 30 .
In addition to devices 36 reducing combustion noise via shielding within stack 26 , the premixing of air and biogas also reduces the amount of air that must flow through dampers 28 so as to reduce the noise generated at dampers 28 . More specifically, because the air is premixed with the fuel, there is no necessity for combustion air to flow though dampers 28 , and only quench air flows through dampers 28 . Dampers 28 can also be used and controlled by controller 22 in response to temperature sensed via thermocouple 64 . The purpose of controlling the temperature inside the unit is to help reduce emissions and control potentially harmful structural temperatures and flame height.
From the foregoing, it will be seen that this invention is one well-adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims since many possible embodiments may be made of the invention without departing from the scope thereof. It is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
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A biogas flare system for burning biogas generated primarily by a landfill includes at least one burner for igniting a mixture of biogas and air. A main supply line supplies a mixture of biogas and air to the burner. A biogas supply line feeds biogas into the main supply line. An air supply line feeds air into the main supply line. A mixer structure mixes the biogas and air prior to the mixture being supplied to the burner.
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BACKGROUND OF THE INVENTION
The present invention relates to collapsible clotheslines and has particular reference to a clothesline of the kind having divergent arms extending from a centre support and lines extending between the arms.
Generally, collapsible clotheslines are designed to be removed from the use location when not required or else to be stored above ground at this location in a collapsed or otherwise partially disassembled state. The removal of a clothesline from its use location naturally involves a measure of inconvenience, which frequently results in the clothesline being left in place even when not in use, thus defeating the advantages offered by that type of clothesline, while storage of a collapsed or partially disassembled clothesline above ground has aesthetic disadvantages, particularly if posts or other such supports remain in place. In addition, collapsing and subsequent re-erection of the clothesline is usually carried out manually, which involves extra time and inconvenience, especially for elderly or handicapped persons.
OBJECTS OF THE INVENTION
One object of the present invention is therefore the provision of a closthesline which can be collapsed and stored in situ in the ground, thereby to conserve space and to conceal the clothesline from view.
Another object of the invention is to provide a clothesline of the kind referred to which can be erected by hydraulic pressure, for example mains water pressure, and collapsed by relief of such pressure.
Other objects and advantages of the invention will be apparent from the following description.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention there is provided a collapsible clothesline comprising a casing, a telescopic stem telescopically retractible into and extensible from the casing, the stem comprising an outer stem element and inner stem element which in use is telescopically retractible downwardly into and extensible upwardly from the outer stem element, first sealing means disposed between the casing and outer stem element to hydraulically seal the casing and outer stem element together, second sealing means disposed between the outer and inner stem elements to hydraulically seal the elements together, a plurality of arms carried by the outer stem element and pivotable between a use position in which they extend subtantially radially of the stem and a storage position in which they extend alongside the stem, a plurality of lengths of line interconnecting the arms, and a plurality of support ties so connecting the arms to the inner stem element at its upper end as to cause the arms to pivot from the storage position to the use position on extension of the inner stem element from the outer stem element and to permit the arms to pivot from the use position to the storage position on retraction of the inner stem element into the outer stem element, the casing being provided with inlet and outlet means for admission and exhaust of liquid under pressure and the inner and outer stem elements being provided with means actable on by such liquid under pressure to effect extension of the outer stem element from the casing and the inner stem element from the outer stem element.
A clothesline according to the invention may be constructed as a self-contained unit which can be stored in a collapsed state in the ground completely out of sight except for the top of the clothesline at ground level. By the admission of liquid under pressure, for example water from a mains source, into the casing the outer stem element can be extended from the casing and the inner stem element in turn from the outer stem element, the extension of the inner stem element simultaneously raising the arms to the use position. The inner and outer stem elements can be retracted simply by relief of such pressure, that is by exhausting the liquid from the casing, and the actions of admitting liquid to and exhausting the liquid from the casing can be carried out by the use of such simple controls as conventional taps or other stop cocks.
For preference the stem is rotatable relative to the casing so that the clothesline can be used in the manner of a conventional rotary clothesline.
The first sealing means expediently comprises a seal fitted on the lower end of the outer stem element and serving as the means actable on by liquid under pressure to effect extension of the outer stem element from the casing. The second sealing means may comprise a similar seal fitted on the lower end of the inner stem element. The sealing means and the means actable on by liquid under pressure can, however, be separate components and the sealing means can be arranged in other locations, for example the second sealing means may comprise a seal fitted to the outer element at its upper end.
Expediently, the arms are pivotally mounted on carrier means at the upper end of the outer stem element, the carrier means preferably being detachably mounted on the outer stem element so as to facilitate disassembly for servicing of the clothesline.
The ties, which preferably comprise flexible connections such as cords, ropes, wires or chains, are for preference connected to the arms intermediate the ends thereof and to a cover member at the upper end of the inner stem element, the cover member serving to cover the upper end of the casing in the collapsed state of the clothesline.
According to a second aspect of the invention there is provided a collapsible clothesline in accordance with the first aspect of the invention, the casing of the clothesline being located in a substantially vertical bore in the ground or equivalent support base.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:
FIG. 1 is a schematic, partly sectioned vertical elevation of a collapsible clothesline according to the said embodiment, the clothesline being in the collapsed state; and
FIG. 2 is a schematic elevation of the clothesline of FIG. 1 in the erected state.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is shown a collapsible clothesline, indicated generally at 10, comprising a tubular plastics casing 11 located in a substantially vertical bore in the ground. The casing 11 is closed at its lower end by a cap 12 and is open at its upper end, the depth of the bore being such that the open end of the casing is substantially flush with the surface of the ground. A concrete surround 13 may be provided around the open end of the casing.
A telescopic stem indicated generally at 14 is mounted in the casing 11 to be rotatable therein and to be telescopically extensible from and retractible into the casing, the stem consisting of an outer and lower plastics pipe 15 and an inner and upper galvanised iron pipe 16 of somewhat smaller diameter than the pipe 15, the pipe 16 being extensible from and retractible into the pipe 15. As can be seen in FIG. 1, the length of the pipe 15 is almost as great as that of the casing 11 while the length of the pipe 16 is about half that of the pipe 15.
The pipe 15 is provided at its lower end with an annular rubber or plastics seal 17 having a peripheral wall which resiliently bears against the inner wall surface of the casing 11 to effect a hydraulic seal between the casing 11 and pipe 15. Between its peripheral wall the pipe 15, the seal 17 has a generally planar pressure surface 17a against which water under pressure acts to raise the stem 14, as will be subsequently explained.
A short distance above the seal 17, the pipe 15 carries a guide 18 equipped with a plurality of wheels 19 running on the inner wall surface of the casing 11. Balls, rollers or other rollable elements may be used in place of the wheels 19. The guide 18 together with the seal 17 centres the pipe 15 in the casing 11 and guides the pipe during its extension from and retraction into the casing. The range of extension of the pipe 15 from the casing 11 is limited by a stop means in the form of an annular abutment 20 arranged at the upper end of the casing to be contacted by and to arrest upward movement of the wheels 19 of the guide 18.
Detachably mounted on the upper end of the pipe 15 is a carrier member 21 provided with four guide channels in which are pivotally mounted four equidistantly spaced metal arms 22, the carrier member 21 being supported on the pipe 15 by means of a collar 23 secured to the pipe. The carrier member 21 is structured so that the arms are pivotable between a storage position in which they extend alongside and thus generally parallel to the pipe 15, as shown in FIG. 1, and a use position in which they extend generally radially of the pipe 15, as shown in FIG. 2. The carrier member 21 includes a peripheral flange portion 24 at its upper end serving as a stop means to limit pivotal movement of the arms beyond the described use position.
The arms 22 are interconnected by lengths of line 25 (shown in FIG. 2 only) which act as supports for laundry or other articles to be aired on the clothesline. For preference, two or more parallel lengths of such line extend between each pair of adjacent arms.
The pipe 16 is similarly provided at its lower end with a rubber or plastics seal 26 which is plugged into the end of the pipe 16 and which has a peripheral wall resiliently bearing against the inner wall surface of the pipe 15 to effect a hydraulic seal between the two pipes 15 and 16. In the area enclosed by its peripheral wall, the seal 26 has a generally planar pressure surface 26a against which water under pressure acts to extend the pipe 15 out of the pipe 16, as will be described in more detail later.
Mounted on the upper end of the pipe 16 is a conical metal cover member 27, the diameter of which is greater than the external diameter of the casing 11 and which provides a closure for the upper end of the casing 11 in the collapsed state of the clothesline as shown in FIG. 1. Four ties 28, for example ropes, cords, wires, chains or other flexible or rigid connections, are each attached at one end to the cover member 27 and at the other end to a respective one of the arms 22 at a point approximately midway along the length of that arm. The arrangement is such that with the pipe 15 substantially completely extended from the casing 11, extension of the pipe 16 from the pipe 15 will cause the ties 28 to pivot the arms 22 from the storage position to the use position. The upward travel of the pipe 16 is arrested when the arms 22 contact the flange 24 of the carrier member 21.
At a location just above the seal 26, the pipe 16 is formed with an opening 29 which is arranged so as to be disposed above the upper end of the pipe 15 when the pipe 16 is fully extended and which serves for the reception of a pin or other locking element bearing on the upper end of the pipe 15 to prevent retraction of the pipe 16. By this means, the pipe 16 can be locked to the pipe 15 with the arms 22 raised in the use position.
The clothesline is also equipped with means for gathering in the lengths of line 25 during lowering of the arms 22 to the storage position, and with reference to FIG. 2 such means consists of four cords or wires 30 which are each connected to the lengths of line 25 between a respective pair of the arms 22 and at a point midway between the arms, extend over a respective pulley 31 mounted on the carrier member 21, and are attached to a common annular counterweight 32 slidably engaged on the pipe 15. When the arms 22 are raised to the use position, the splaying of the arms results in the counterweight 32 being drawn up the pipe 15 and, in effect, suspended by the cords or wires 30 from the lengths of line 25 so that the latter are held in tension, and when the arms are lowered to the storage position the counterweight 32 slides down the pipe 15 to pull the lengths of line 25 towards the carrier member 21.
In an alternative arrangement, which is not illustrated in the drawings, the means for gathering in the lengths of line 25 comprises a respective cord or wire connected to the lenghts of line 25 between each pair of adjacent arms at a point midway between the arms, and a coil spring connecting the cord or wire, or the innermost one of the lengths of line 25, to the carrier member 21. The spring is tensioned when the arms are in the use position and relaxed during movement of the arms to the storage position, so as to draw the lengths of line 25 towards the carrier member 21.
Finally, the casing 11 is provided in its base cap 12 with inlet and outlet means for admission and exhaust of water under pressure, the inlet and outlet means being provided by respective openings in the cap 12 through which extend, or with which communicate, a pair of water pipes 33 each incorporating a tap or other stop cock (not shown). One of the water pipes 33, acting as an inlet pipe, is connected to a source of mains water and the other water pipe, acting as an outlet pipe, is arranged to discharge into a drain, gutter or other receptacle or simply onto the ground.
In used of the clothesline 10 hereinbefore described, the clothesline is located in position by insertion of the casing 11 into a suitable bore drilled or dug in the ground at a chosen site, the water pipes 33 are laid in, and the concrete surround 13 is poured or placed around the upper end of the casing 11.
To erect the clothesline, the tap or stop cock in the inlet water pipe is opened to allow water under pressure to flow into the casing 11 and the interior of the pipe 15 below the seal 26. The water pressure acts on the pressure surfaces 17a and 26a of the seals 17 and 26 to initially extend the pipe 15 out of the casing 11 and then with the arms 22 clear of the casing, to extend the pipe 16 out of the pipe 15. As the pipe 16 is extended out of the pipe 15, the ties 28 act to pull the arms 22 up from the storage position of FIG. 1 to the use position of FIG. 2, the counterweight 32 being drawn up the pipe 15 and acting to tension the lengths of line 25. Once the clothesline is fully erected, the tap or stop cock of the inlet water pipe may be turned off, the tap or stop cock of the outlet water pipe of course remaining closed.
The clothesline is now ready for use in the conventional manner and clothes or other items of laundry can be suspended from the lenghts of line 25, the stem 14 being rotatable in the casing 11 so that the clothesline functions as rotary clothesline.
When it is desired to collapse the clothesline, the tap or stop cock in the outlet water pipe is opened to allow the water to escape from the casing 11 and the interior of the pipe 15, which thus relieves the pressure applied to the pressure surfaces 17a and 261 of the seals 17 and 26. The construction and arrangement of the clothesline 10 is such that initially the pipe 16 is fully retracted into the pipe 15, with the arms lowering to the storage position under their own weight and the weight of the counterweight 32 gathering in the lengths of line 25, and then the pipe 15 together with the pipe 16 and arms 22 is retracted into the casing 11. When the pipe 15 is fully retracted into the casing, the cover member 27 comes to bear on the concrete surround 13 and thus covers over and conceals the rest of the clothesline.
The tap or stop cock of the outlet water pipe may now be turned off so that the clothesline is in readiness for re-erection.
If it is desired to adjust the height of the fully erected clothesline, a pin or other fastening element can be inserted in the opening 29 in the pipe 16 to lock the pipes 15 and 16 together with the arms in the use position, and a quantity of water can be bled-off by opening the tap or stop cock of the outlet water pipe. This will result in the stem 14 descending in the casing 11 to an extend governed by the amount of water bled-off, thus placing the lengths of line 25 at a lower level to facilitiate the attachment or removal of laundry. The stem 14 can of course be raised back to its fully extended position simply by admitting a replacement quantity of water into the casing 11.
It will be readily apparent that modifications to the clothesline may be made without departing from the scope of the invention as defined in the appended claims, for example different arrangements may be made for the supply and exhaust of water under pressure, including the coupling of a simple garden hose, the seals maya be arranged in different locations, additional seals may be used and the pressure surfaces may be entirely separate from the seals.
The clothesline hereinbefore described is thus convenient and economical to operate, does not require lengthy or awkward assembly and disassembly by hand, and is always available at the use location, yet concealed from view.
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A collapsible clothesline intended to be stored in situ in the ground and to be erected by water pressure. The clothesline comprises a casing intended to be located in a bore in the ground and a stem which is retractible into and extensible from the casing. The stem itself consists of an inner and an outer stem element, with the former being retractible downwardly into and extensible upwardly from the latter. A number of arms, linked by lines for supporting laundry, are pivoted to the other stem element and are connected by ties to the upper end of the inner stem element. When the inner stem element is extended from the outer stem element, with the other stem element already extended from the casing, the ties pull the arms up from a storage position, in which they lie alongside the stem, to a use position, in which they extend radially from the stem. The clothesline is erected by supplying water pressure to the casing interior and collapsed by relieving such pressure.
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FIELD OF THE INVENTION
The present invention relates to shelters, such as tents and canopies, formed from flexible membranes. In particular, the present invention relates to an inflatable shelter that has few parts, that is simple to manufacture and that is to easy to set up and repair.
BACKGROUND OF THE INVENTION
Portable shelters, such as tents and canopies, are employed to provide cover and protection from the elements such as sun, rain and wind. Such portable shelters generally include a flexible lightweight membrane, such as canvas, which is supported by poles or inflated members. Although more easily erected as compared to pole supported shelters, inflatable shelters are typically more expensive to manufacture, are more subject to failure and are more difficult to repair. Conventional inflatable shelters utilize either a single extremely complex shaped inflatable member or multiple tubes that have axial ends that converge at the apex of the shelter or that overlap one another at the apex of the shelter. Shelters that employ a single inflatable member are extremely complex and difficult to manufacture. Moreover, once damaged, the entire shelter must be replaced. Shelters employing multiple tubes that have axial ends converging at the apex of the structure require a greater number of parts, are time consuming to assemble and are subject to leakage. Shelters employing multiple tubes that overlap one another at the apex of the structure result in the outer perimeter of the shelter being multi-tiered such that the shelter is difficult to cover with a fly. Moreover, such shelters are unattractive due to the outer surface discontinuity.
As a result, there is a continuing need for an inflatable structure or shelter that is easy to manufacture, requires fewer parts, is easy to assemble, is easily erected and is easily repaired.
SUMMARY OF THE INVENTION
The present invention provides an inflatable shelter that includes a flexible membrane, a first elongate inflatable tube supported by the flexible membrane and a second elongate inflatable tube supported by the flexible membrane. The first tube has first and second axial ends and a first intermediate portion between the first and second axial ends. The second tube has third and fourth axial ends and a second intermediate portion between the third and fourth axial ends. The first, second, third and fourth axial ends terminate in a plane. The first and second intermediate portions converge towards one another such that the first and second tubes form four legs supporting the membrane.
The present invention also provides for an inflatable shelter including a first sleeve defining a first lumen, a second sleeve defining a second lumen, a first inflatable tube received within the first lumen, and a second inflatable tube received within the second lumen. The first sleeve has first and second axial ends and a first intermediate portion between the first and second axial ends. The second sleeve has third and fourth axial ends and a second intermediate portion between the third and fourth axial ends. The first and second intermediate portions converge. The first and second lumens are separated by at least one divider panel extending parallel to the first and second lumens.
The present invention also provides an inflatable shelter including a plurality of sleeves defining a plurality of lumens, a plurality of wall panels coupled to and extending between the plurality of sleeves and a plurality of elongate inflatable tubes disposed within the plurality of sleeves, respectively. Each of the plurality of tubes are insertable into and removable from the plurality of sleeves such that each of the plurality of tubes may be replaced.
The present invention also provides a shelter shell for being supported by a plurality of inflatable tubes, whereby inflation of the tubes supports the shell. The shelter shell includes a plurality of sleeves providing a plurality of lumens configured to removably receive the plurality of inflatable tubes, respectively, and a plurality of wall panels coupled to and extending between the plurality of sleeves. Each of the sleeves is preferably air permeable and is configured to completely surround a circumference of the tube disposed therein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view schematically illustrating an inflatable shelter supported by a plurality of inflatable tubes in an inflated state.
FIG. 2 is a fragmentary perspective sectional view of the shelter of FIG. 1 taken along lines 2 — 2 .
FIG. 3 is a fragmentary sectional view of the shelter of FIG. 2 taken along lines 3 — 3 .
FIG. 4 is a sectional view of a first axial end of one of the inflatable tubes of FIG. 1 .
FIG. 5 is a sectional view of a second axial end of the inflatable tube of FIG. 4 .
FIG. 6 is a fragmentary top elevational view of an exemplary manifold and set of air lines of the shelter of FIG. 1 .
FIG. 7 is a side elevational view of the manifold of FIG. 6 with the air lines shown in section.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a perspective view schematically illustrating an inflatable shelter 10 in an inflated state. As shown by FIG. 1, shelter 10 generally includes cover or membrane 12 , inflatable tubes 14 , 16 , 18 , manifold 20 , inflation lines 24 , 26 , 28 and pump 30 . Membrane 12 comprises a flexible sheet or a series of sheets stitched, bonded or otherwise connected together to form sleeves 32 and panels 33 . Sleeves 32 comprise fabric tubes sized to receive inflatable tubes 14 , 16 and 18 . Sleeves 32 extend between and are interconnected to panels 33 . Sleeves 32 provide a flexible and collapsible framework for panels 33 and the remainder of shelter 10 . Upon inflation of tubes 14 , 16 and 18 within sleeves 32 , sleeves 32 rigidify to support panels 33 .
Panels 33 comprise single sheets which are stitched or otherwise affixed to and between sleeves 32 . Panels 33 provide a majority of the covering provided by shelter 10 . Panels 33 are preferably formed from a water resistant, yet breathable imperforate fabric. Alternatively, panels 33 may be at least partially formed from a perforated fabric. For example, when used as a tent shelter, panels 33 may include portions which are perforated to provide increased ventilation to the interior of shelter 10 . In such embodiments, imperforate or water resistant or panels may be additionally positioned over the perforated portions of panels 33 to prevent the ingress of water and moisture. In the exemplary embodiment, panels 33 are formed from a typical tent material having a relatively large degree of flexibility such as breathable nylon.
Tubes 14 , 16 and 18 (schematically shown in FIG. 1) are substantially identical to one another and comprise individual inflatable members having axial ends 34 , 36 and intermediate portions 38 . Axial ends 34 and 36 of each tube 14 , 16 , 18 terminate in a single plane 42 . Depending upon the particular application of shelter 10 , plane 42 will either extend along the ground or other surface supporting shelter 10 or will comprise a lower most extending portion of a roof or cover which is elevated above the ground by poles or additional inflatable structures.
As further shown by FIG. 1, each tube 14 , 16 , 18 extends along a generally arcuate path such that intermediate portions 38 converge towards one another above plane 42 . As a result, tubes 14 , 16 , 18 , upon being inflated, form a self-supporting framework which is stronger at the junctions of intermediate portions 38 to better carry loads placed upon shelter 10 . In addition, each individual tube 14 , 16 , 18 provides multiple legs of the framework. As a result, shelter 10 requires fewer parts, is less expensive to manufacture, is easier to assemble and is less prone to damage or leakage.
Manifold 20 directs pressurized air via inflation lines 24 , 26 , 28 to each of tubes 14 , 16 , 18 to inflate tubes 14 , 16 , 18 . Manifold 20 is configured to simultaneously inflate tubes 14 , 16 and 18 . Alternatively, manifold 20 may be configured to provide selective and independent inflation of tubes 14 , 16 and 18 . Although less desirable, manifold 20 may be omitted, whereby tubes 14 , 16 and 18 would have to be individually inflated one at a time.
Pump 30 is conventionally known and provides pressurized air to manifold 20 . Pump 30 preferably comprises an electrically powered air pump. In the exemplary embodiment, pump 30 includes a conventionally known electrical connector 46 configured for being plugged into a conventional vehicle cigarette lighter 48 . As a result, shelter 10 may be easily inflated at a remote location where electrical outlets are not available by simply plugging pump 30 into cigarette lighter 48 of a vehicle. Alternatively, shelter 10 may be provided with other mechanisms for providing pressurized air to manifold 20 and tubes 14 , 16 and 18 . For example, pump 30 may alternatively comprise a manually actuated air pump or an air compressor.
FIGS. 2 and 3 illustrate sleeves 32 of membrane 12 and intermediate portions 38 of tubes 14 and 16 in greater detail. FIG. 2 is a fragmentary perspective view of shelter 10 taken along lines 2 — 2 of FIG. 1 . FIG. 3 is a fragmentary sectional view of shelter 10 taken along lines 3 — 3 of FIG. 2 . As shown by FIGS. 2 and 3, sleeves 32 are generally tubular walls which define inner lumens 52 that receive tubes 14 , 16 and 18 (shown in FIG. 1 ). Sleeves 32 are preferably formed from a non-stretchable material. In the exemplary embodiment, sleeves 32 are formed from sail cloth or Dacron. Each lumen 52 has a diameter less than or equal to the maximum diameter of each of tubes 14 , 16 , 18 when inflated. As a result, sleeves 32 prevent tubes 14 , 16 , 18 , which preferably comprise bladders, from being over-inflated. Sleeves 32 also protect tubes 14 , 16 and 18 from abrasion and other damage. Moreover, because sleeves 32 are not required to be airtight, sleeves 32 are still functional despite minor abrasion and wear over time. When normally and safely inflated, tubes 14 , 16 and 18 have maximum outer diameter greater than the inner diameter of sleeves 32 . Although not shown in a fully inflated state, tubes 14 , 16 and 18 , upon being sufficiently inflated, expand against the tubular walls forming sleeves 32 to place sleeves 32 and panels 33 in tension for increased strength and load capacity. Although sleeves 32 are illustrated as being formed from fabric sheet sewn together and further sewn to panels 33 extending between sleeves 32 , sleeves 32 may alternatively be formed as part of a single fabric sheet or may be independently formed and secured to membrane 12 by various other attachment methods such as stitching, heat welding, adhesives or fasteners. Although less desirable, inflatable tubes 14 , 16 and 18 may alternatively have a maximum outer diameter less than or substantially equal to the inner diameter of sleeves 32 , whereby the tubes, upon being inflated, support sleeves 32 and panels 33 without placing sleeves 32 and panels 33 in great tension.
As best shown by FIG. 3, sleeves 32 preferably include multiple branches or segments 56 . Each segment 56 extends between the junctions of intermediate portions 38 at which the segments 56 angle away from one another. For example, at the junction of intermediate portions 38 of tubes 14 and 16 , shelter 10 includes four sleeve segments 56 a , 56 b , 56 c and 56 d . Sleeve segments 56 a and 56 b provide an elongate continuous lumen 52 which receives tube 14 . Sleeve segments 56 c and 56 d provide an elongate continuous lumen 52 which receives tube 16 . As shown by FIG. 3, segments 56 a , 56 b , 56 c and 56 d are interconnected with one another in a generally X-shaped configuration such that the continuous lumens 52 provided by segments 56 a , 56 b and segments 56 c and 56 d converge towards one another. As a result, intermediate portions 38 of tubes 14 and 16 converge towards one another. More importantly, segments 56 a and 56 b retain tube 14 along a non-linear axis while segments 56 c and 56 d retain tube 16 along a non-linear axis. As a result, tubes 14 and 16 may comprise inexpensive elongate linear bladders or tubes which are inserted through the sleeves prior to inflation. In addition, tubes 14 and 16 may be easily removed from sleeves 32 for replacement or repair.
As further shown by FIG. 3, sleeves 32 include a divider panel 60 extending between the lumens 52 provided by segments 56 a , 56 b , 56 c , 56 d . Divider panel 60 preferably extends parallel or tangent to adjacent portions of tubes 14 and 16 . Divider panel 60 is preferably formed from the same material as that of sleeves 32 and membrane 12 . In particular, divider panel 60 is formed from a flexible sheet of material which is generally unstretchable. Alternatively, divider panel 60 may be formed from a variety of alternative materials. Divider panel 60 serves as a partition between the lumen 52 provided by segments 56 a , 56 b and the lumen provided by segments 56 c , 56 d to prevent over-inflation of either of tubes 14 and 16 while permitting tubes 14 and 16 to extend as close as possible to one another so as to produce a stronger, more rigid and more visually appealing junction. In addition, because tubes 14 and 16 extend adjacent one another in a side-by-side relationship without vertically overlapping one another, the outer perimeter of shelter 10 is cleaner such that supplemental covers such as flys may be more easily positioned over shelter 10 . Although sleeves 32 are illustrated as including a single divider panel 60 at the junction of segments 56 a , 56 b , 56 c and 56 d , sleeves 32 may alternatively include more than one divider panel 60 . For example, segments 56 a , 56 b may be continuously joined and segments 56 c , 56 d may be continuously joined, wherein the wall joining segments 56 a , 56 b is fastened to the wall joining segments 56 c , 56 d such that the two walls partition the side-by-side lumens from one another.
FIGS. 4 and 5 illustrate opposite axial ends 34 , 36 of tube 14 in greater detail. As shown by FIG. 4, axial end 34 of tube 14 is axially sealed by cap 62 but includes an inflation port 73 through which the interior 66 of tube 14 is inflated. As shown by FIG. 5, axial end 36 of tube 14 is completely sealed by cap 64 . In the exemplary embodiment, cap 62 generally includes plug 68 , closure 70 and fastener 72 . Plug 68 comprises a member having an outer diameter sized for being received in the axial end of tube 14 . Plug 68 defines inflation portion 64 and includes a nipple 77 adapted for being connected to inflation line 24 .
Closure 70 is a generally cup-shaped member having a bottom 74 , an annular portion 76 and a passage 78 through which inflation line 24 extends to be connected to nipple 77 of plug 68 . Annular portion 76 has an inner diameter greater than the outer diameter of tapered plug 68 . As shown by FIG. 4, annular portion 76 and plug 68 cooperate to capture the wall of tube 14 therebetween. In the exemplary embodiment, plug 68 is tapered so as to have an enlarged diameter at end 75 such that as plug 68 is drawn towards bottom 74 of closure 70 , tube 14 is compressed between plug 68 and annular portion 76 . As will be appreciated, annular portion 76 or both annular portion 76 and plug 68 may alternatively be tapered or otherwise provided with an enlarged diameter at one end such that tube 14 is compressed between plug 68 and annular portion 76 as plug 68 and closure 70 are drawn towards one another.
Fastener 72 interconnects plug 68 to closure and draws plug 68 towards closure 70 . Fastener 72 preferably comprises a threaded member which is threadably received within plug 68 and which upon being rotated draws plug 68 towards bottom 74 .
FIG. 5 illustrates axial end 36 of tube 14 . As shown by FIG. 5, axial end 36 includes cap 64 . Cap 64 is identical to cap 62 except that cap 64 includes plug 88 in lieu of plug 68 closure 90 including annular portion 96 in lieu of annular portion 76 . Plug 88 and closure 90 are identical to plug 68 and closure 70 except that plug 88 is generally imperforate so as to completely occlude the axial end of tube 14 . Annular portion 96 omits passage 78 .
As further shown by FIGS. 4 and 5, sleeve 32 receives axial ends 34 and 36 of tube 14 as well as a majority of closure 70 . Each end of sleeve 32 includes an end flap 92 which extends across axial ends of sleeve 32 . Each end flap 92 is preferably made of the same material as the remainder of sleeve 32 and is secured by stitching to the remainder of sleeve 32 . Each end flap 92 includes an opening 94 sized to enable tube 14 with either plug 68 and annular portion 76 or plug 88 and annular portion 96 to be inserted therethrough. During insertion, plug 68 and 88 and annular portion 76 and 96 are turned sideways. Once inserted plug 68 , 88 and annular portion 76 , 96 are reoriented to face bottom 74 with flap 92 captured between bottom 74 and annular portion 76 at end 34 or annular portion 96 at end 36 . As a result, as fastener 72 draws either plug 68 or 88 towards bottom 74 , fastener also secures flap 92 and sleeve 32 to closures 70 and 90 . End flaps 92 assist in maintaining the shape of sleeve 32 when tube 14 is fully inflated against sleeve 32 to place sleeve 32 in tension. End flaps 92 further prevent tube 14 from extending past the axial ends of sleeves 32 when fully inflated.
Overall, caps 62 and 64 enable shelter 10 to utilize elongate inflatable tubes or hoses having open axial ends. Consequently, the manufacture of shelter 10 is simpler and less expensive. Moreover, because caps 62 and 64 may be easily disconnected from tube 14 , caps 62 and 64 may be reused when tube 14 is replaced. Although not illustrated in detail, the axial ends 34 and 36 of tubes 16 and 18 are identical to the axial ends 34 and 36 of tube 14 , respectively.
FIGS. 6 and 7 illustrate an exemplary embodiment of manifold 20 and air supply lines 24 , 26 and 28 in greater detail. As shown by FIGS. 6 and 7, manifold 20 generally includes housing 100 , valve actuator 102 , and connectors 104 . Housing 100 forms the main body of manifold 20 and defines an inlet port 106 and three outlet ports 108 , 110 and 112 which communicate with an internally defined and conventionally known valve mechanism (not shown) situated between port 106 and ports 108 , 110 , 112 . Port 106 receives air intake line 31 extending from pump 30 (shown in FIG. 1 ). Ports 108 , 110 and 112 provide openings by which air lines 24 , 26 and 28 are connected.
Actuator 102 preferably comprises a large ergonomic knob connected to the internal valve. Rotation of actuator 102 about axis 116 moves the internal valve between a closed position in which pressurized air flowing through line 31 from pump 30 as indicated by arrow 118 is sealed or closed off from air lines 24 , 26 and 28 , and an opened position in which air line 31 pneumatically communicates with each of air lines 24 , 26 and 28 such that pressurized air provided by pump 30 through line 31 further flows through air lines 24 , 26 and 28 as indicated by arrows 124 , 126 and 128 , respectively, to simultaneously inflate each of tubes 14 , 16 and 18 , respectively. Although actuator 102 and the internally formed, conventionally known valve are illustrated and described as being configured for providing the aforementioned closed and opened states wherein pressurized air is simultaneously supplied to each of air lines 24 , 26 and 28 , actuator 102 and the internally formed valve may alternatively be configured, in a conventionally known manner, to have multiple positions wherein pressurized air may be supplied to air lines 24 , 26 and 28 simultaneously as well as independently of one another.
As best shown by FIG. 7, housing 100 of manifold 20 preferably has a concave side 132 such that housing 100 conforms to the diameter of one of sleeves 32 when one of tubes 14 , 16 or 18 is inflated. As a result, manifold is more visually appealing when positioned adjacent to shelter 10 . In addition, manifold 20 may be more easily secured and reliably mounted to shelter 20 by connectors 104 .
Connectors 104 secure manifold 20 to shelter 10 . At the same time, connectors 104 enable manifold 20 to be disconnected from shelter 10 such as when shelter 10 is being collapsed for storage or transportation or such as when either shelter 10 or manifold 20 requires repair or replacement. Connectors 104 preferably comprise conventionally known shock cords which are snapped inside housing 100 . As a result, connectors 104 releasably secure manifolds 20 to shelter 10 regardless of whether shelter 10 is in an inflated or a deflated state. Furthermore, because connectors 104 preferably comprise shock cords, connectors 104 reliably connect manifold 20 to shelter 10 without any rigid or sharp protruding edges which could puncture membrane 12 and without the need for rigid fasteners or other adhesives. Although less desirable, manifold 20 may be otherwise secured to shelter 10 utilizing adhesives, fasteners or other mounting mechanisms.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. The present invention described with reference to the preferred embodiments and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element also encompass a plurality of such particular elements.
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An inflatable shelter includes a flexible membrane, a first elongate inflatable tube supported by the flexible membrane and a second elongated inflatable tube supported by the flexible membrane. The first tube has first and second axial ends and a first intermediate portion between the first and second axial ends. The second tube has third and fourth axial ends and a second intermediate portion between the third and fourth axial ends. The first, second, third and fourth axial ends terminate in a plane. The first and second intermediate portions converge towards one another such that the first and second tubes form four legs supporting the membrane. The flexible membrane preferably includes first and second sleeves defining first and second lumens receiving the first and second inflatable tubes, respectively, and a plurality of wall panels coupled to and extending between the first and second sleeves. The first and second lumens of the first and second sleeves are separated by at least one divider panel extending substantially parallel to the first and second tubes. The first and second tubes are insertable into and removable from the first and second sleeves, respectively, such that the first and second tubes are replaceable.
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FIELD OF THE INVENTION
[0001] The present invention relates to a synthetic fiber rope consisting of strands that are arranged in at least one layer of strands, a strand consisting of twisted yarns and a yarn consisting of synthetic fibers, at least one strand having at least one layer of strands of indicator fibers or at least one indicator yarn to monitor the service life of the rope.
BACKGROUND OF THE INVENTION
[0002] From Patent Application EP 1 371 597 A1 a sheathed rope used as suspension means for elevators has become known. The rope has inner strand layers and outer strand layers, a strand layer consisting of several twisted strands and the direction of twist of the inner strand layer being opposite to the direction of twist of the outer strand layer. The tensile strength of the inner strand layer is higher than the tensile strength of the outer strand layer. Each strand is constructed of twisted and impregnated aramid synthetic fibers. The service life of the outer strand layer is less than the service life of the inner strand layer. For the purpose of monitoring the rope, individual strands of the outer strand layer are provided with electrically conducting wires, every two adjacent strands being provided with electrically conducting wires that mutually abrade and thereby promptly detect the expiration of the service life of the rope or the end of the rope life of the rope.
[0003] From Patent Application EP 0 731 209 A1 a sheathed rope used as suspension means for elevators has become known. The rope has inner strand layers and outer strand layers, a strand layer consisting of several twisted strands and the direction of twist of the inner strand layer being in the same direction as the direction of twist of the outer strand layer. Each strand is constructed of twisted and impregnated aramid synthetic fibers. For the purpose of monitoring the rope service life or state of wear of the synthetic fiber rope, in each case one strand of a layer of strands is provided with electrically conductive carbon fibers. In regular operation, it is always the case that the carbon fibers either as a result of excessive stretching or an excessive number of reverse bendings snap or break sooner than the load-bearing aramid fibers of the strand. With the aid of a voltage source, the number of snapped carbon fibers can be determined. So that the residual load-bearing capacity of the synthetic fiber rope can be assured, only a certain percentage of the carbon fibers may fail. The elevator is then automatically driven to a predetermined stop and switched off.
SUMMARY OF THE INVENTION
[0004] It is here that the present invention sets out to provide a remedy. The present invention solves the problem of creating a synthetic fiber rope with increased sensitivity for monitoring the rope service life.
[0005] Monitoring of the rope service life is a basic problem of all synthetic fiber ropes, especially such ropes that are surrounded by a sheath.
[0006] According to the present state of the art, the carbon fibers can be selected and arranged according to the load situation in the rope. A disadvantage of this method can be that the parameters that should be conditioned cannot be optimally adapted to each other and the suspension means must be replaced too early so as to be sufficiently far away from the critical condition. In elevator construction, synthetic fiber ropes that serve as suspension means can be used up to 60% to 80% of the residual breaking strength relative to the normal breaking strength. The more accurately this point can be reached, the more economically the suspension means can be used.
[0007] Depending on the type, field of application, and safety requirements of the synthetic fiber rope application, the requirements for the monitoring sensitivity of the indicator strands of the synthetic fiber rope are increased. Correct responsive behavior and reproducibility depending on the requirement are advantageous characteristics of the synthetic fiber rope according to the present invention. It is known that synthetic fiber ropes serving as suspension means for elevators are permanently electrically monitored by means of yarns of carbon fiber that are integrated in the rope strands. This has the advantage that the synthetic fiber ropes are monitored over their entire length including areas that are not visible as, for example, the areas in the rope sockets. The synthetic fiber ropes detect the abrasive wear within the rope and reliably detect damage acting from outside and give the elevator user a maximum of safety through the continuous connection to the elevator control which in case of need can respond quickly and uncompromisingly.
[0008] The requirements for a modern monitoring of suspension means have increased relative to the past. So that the synthetic fiber rope can be taken to its limit of failure, and thus the economic potential of the new type of suspension means more fully exploited, or the user can set a sensitivity for detection of the state of wear of the rope that is needed for his requirements, the strands with indicator fibers must be even better adjustable in their response behavior, the indicator fibers of the strands having a high probability of losing their electrical conductivity depending on a number of reverse flexures and residual breaking force and thereby detecting a worn rope.
[0009] An indicator fiber or an indicator yarn can be of any material that in any form is conductive, as for example fibers with light-conducting properties or metal coated technical fibers, carbon fibers, etc. that are electrically conductive, the fibers with direct contact wearing sooner than the load-bearing fibers.
[0010] For permanent monitoring, the conductive indicator fibers are contacted at the rope-end and connected to instruments. At one rope-end, the indicator fibers are connected to a signal transmitter and at the other rope-end the indicator fibers are connected to a signal receiver. The transmitter signal is measured by means of the signal receiver and the condition of the indicator fibers is evaluated on the basis of the measured or absent signal. EP 0 731 209 A1 shows an example of an indicator fiber monitoring by means of electric signals.
[0011] A synthetic fiber rope consists of a plurality of twisted strands that are arranged in different layers, each strand consisting of twisted yarns, a yarn consisting of, for example, 1000 synthetic fibers. A raw yarn consists either of unidirectional synthetic fibers or, for better processability, already has from the factory a protective twist of, for example, 15 turns per meter. In general, “fiber” is used as a length-independent generic term for all textile fiber materials. “Filament” is the term used in chemical fiber manufacturing for textile fibers of great, or virtually endless, length. The direction of twist of the yarn in the strands is so foreseen that the individual fiber is advantageously aligned in the direction of tension of the rope or in the longitudinal axis of the rope. The synthetic fiber rope can be constructed of chemical fibers as, for example, aramid fibers or fibers of related type, polyethylene fibers, polyester fibers, glass fibers, etc. The synthetic fiber rope can consist of one or two or three or more than three layers of strands. At least one strand of at least one layer of strands has indicator fibers or at least one indicator yarn for monitoring the rope service life.
[0012] According to the present invention, the plastic, also called matrix, that surrounds the strand that is provided with at least one indicator fiber or indicator yarn has a lower resistance to abrasion than the matrix of the other strands.
DESCRIPTION OF THE DRAWINGS
[0013] The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
[0014] FIG. 1 is a schematic diagram of an elevator system using a synthetic fiber rope according to the present invention; and
[0015] FIG. 2 is a schematic cross-sectional view of the rope shown in FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical.
[0017] In the synthetic fiber rope according to the present invention, the matrix material or resin that surrounds the strands of the strands with indicator fibers or indicator yarns consists of a softer plastic (for example Shore hardness scale A) than the matrix materials (for example Shore hardness scale D) of the neighboring or other strands, as a result of which these strands relative to a strand without indicator fibers or indicator yarn has a lower resistance to abrasion. As an alternative to the softer plastic, the matrix material can be impregnated with a softener. For this purpose, known softeners can be used. As a result of the poorer abrasion behavior of the strands with indicator fibers, through the movement relative to the adjacent strands that arises during bending, an early onset of wear and thus an earlier failure of the indicator fibers in the strands is provoked. The strand with indicator fibers or indicator yarn acts as intended breaking point. The strand with indicator fibers or indicator yarn is referred to hereafter as an “indicator strand”. Depending on the type and amount of the selected softener, the increase in wear can be controlled.
[0018] Phthalate and adipate are typical softeners that maker the strands softer, their lateral rigidity lower, and their resistance to abrasion lower. Through a selected weight ratio of 1% to 30% on the matrix of the indicator strand, the matrix can be executed “softer” relative to the neighboring strands, the abrasion behavior worsening with increasing amount of softener depending on the degree of softness.
[0019] Furthermore, the matrix material of the neighboring strand or other strands (strand without indicator fibers or indicator yarn) that is identical to the matrix material of the indicator strands can be impregnated with an additive that reduces the friction relative to the indicator strand. Examples of additive that can be added are waxes or small amounts of Teflon (1 to 3% wax or 5 to 15% Teflon powder relative to the solid content of the matrix excluding the fiber content).
[0020] Further, the matrix material of the indicator strand that is identical to the matrix material of the neighboring strand can be treated during manufacture in such manner that the plastic matrix degrades until the hardness and the wear resistance diminish. This is achieved by a temperature treatment of the indicator strand at a temperature greater than 230° F. and a treatment time of more than 20 seconds. As a result of the temperature, the long molecule chains that are required for the material properties separate to such an extent that on cooling the molecules no longer completely recombine. To support this process, water molecules can be added to the strands matrix, which prevents a complete recombination of the molecule chains. As substitute, other molecules are conceivable that impair or prevent the recombination. An initial degradation of the matrix occurs that causes a sharply lower abrasion resistance and thereby provokes a failure of the indicator fibers or of the indicator yarn. The abrasion protection is caused to deteriorate in targeted manner.
[0021] The indicator fibers or indicator yarn are/is located near to the surface of the strand and participates in the spiral structure of the synthetic fibers or of the synthetic fiber yarn. On account of the softer strands matrix, the indicator fibers or the indicator yarn are worn through. The permanent monitoring of the load-bearing strand is thereby interrupted and detected as wear before the other load-bearing strands are affected. This assures that the indicator strands not only have a different performance capacity on account of the different extension to breaking elongation, but also that a reliable failure probability is generated as a result of the different hardness of the matrix. (The breakage extension is the extension of a fiber, a yarn, or a strand until it breaks.)
[0022] There is also the further possibility of positioning the indicator strands in a multilayer synthetic fiber rope in such manner that the load that is absorbed is higher than that in the neighboring strands. For example, in a synthetic fiber rope with three strand layers, the two inner concentric strand layers absorb a higher proportion of the load since although the length of lay relative to the outermost layer is constant, the angle of lay relative to the midpoint of the synthetic fiber rope constantly decreases. In a laid rope, the strands lie significantly steeper, as a result of which the strands are shorter or longer depending on the layer. In view of the geometrical limitation, the innermost strands are the shortest and therefore bear the greater load. It is therefore advisable to arrange further indicator fibers or indicator yarns in individual strands of the two inner strand layers. In the case of a three-layer rope, the middle strand layer is to be preferred since on account of the different wrapping radii and therefore different bending speeds this layer is subject to higher stress loads.
[0023] Furthermore, for the strand construction of the strand without indicator fibers a synthetic fiber with very good dynamic reverse bending capacity can be used. For the indicator yarn of the indicator strand the indicator fibers (for example carbon fibers) can be combined with synthetic fibers (for example carbon fibers) whose dynamic reverse bending capacity is inferior to that of the other synthetic fibers of the indicator strands or that of the strand without indicator fibers. The superior synthetic fibers exist for the application of running suspension means on the basis of co-polymers, for example copolyterephthalamide, the under these conditions inferiorly functioning fibers can be of poly-p-phenylenterephthalamide. (The dynamic reverse bending capacity is the reverse bending capacity under changing loads.)
[0024] Furthermore, for the construction of the indicator yarn, the indicator fibers (for example carbon fibers) can be combined with synthetic fibers which, relative to the other synthetic fibers of the indicator strand or relative to the synthetic fibers of the strand without indicator yarn, have a higher modulus of elasticity. For the synthetic fibers that are combined with the indicator yarns in the indicator strands, Twaron (registered trademark) fibers, for example, with a modulus of elasticity of 100,000 to 120,000 N/mm 2 , can be used. The other fibers of the non-indicator strands can consist of, for example, Technora (registered trademark) fibers with 76,000 N/mm 2 . Twaron fibers and Technora fibers are manufactured by Teijin Aramid BV, the Netherlands.
[0025] The aforementioned measures to monitor the rope service life can also be combined. For example, the resistance to abrasion can be provided by changing the strands matrix and, at the same time, the indicator yarn can consist of indicator fibers and synthetic fibers that in relation to stress are inferior to the other synthetic fibers.
[0026] FIG. 1 shows an elevator installation incorporating a synthetic fiber rope 1 according to the present invention. An elevator car 12 is suspended from one end of the rope 1 . A motor 13 drives a traction sheave 14 that engages the rope 1 and moves the car 12 vertically in an elevator shaft 15 . An opposite end of the rope 1 is attached to a counterweight 16 in the shaft 15 . A signal transmitter 17 is connected to the end of the rope 1 at the car 12 and a signal receiver 17 ′ is connected to the end of the rope 1 at the counterweight 16 . The positions of the signal transmitter 17 and the signal receiver 17 ′ can be reversed and they cooperate to detect the condition of the indicator fibers by the presence or absence of a signal generated by the transmitter through the indicator fibers to the receiver. A buffer 18 is provided in the bottom of the shaft 15 .
[0027] FIG. 2 shows the synthetic fiber cable 1 according to the present invention. The synthetic fiber cable 1 comprises several strand layers, an outer strand layer 2 , a first inner strand layer 3 , a second inner strand layer 4 and a core layer 5 . A cable sheathing is denoted by 6 . Construction and diameter of the strands 7 of the outer strand layer 2 are identical. The first inner strand layer consists of, in diameter, larger strands 8 and smaller strands 9 . The larger strands 8 approximately correspond in diameter with the strands 10 of the second inner strand layer 4 and of the core strand 5 . The strands 7 of the outer strand layer 2 are larger in diameter than the larger strands 8 of the first inner strand layer 3 and of the strands 10 of the second inner strand layer 5 . The larger strands 8 of the inner strand layers 3 , 4 are larger in diameter than the smaller strands 9 of the first inner strand layer 3 . The larger strands 8 of the first strand layer 3 and the strands 10 of the second inner strand layer 4 are, in diameter, of approximately the same size as the core strand 5 . The strands 10 of the second inner strand layer 4 are stranded around the core strand 5 , the strands 8 , 9 of the first inner strand layer 3 are stranded around the second strand layer 4 and the strands 7 of the outer strand layer 2 are stranded around the first inner strand layer 3 . FIG. 2 is similar to FIG. 1 of co-pending application Ser. No. 11/863,401 filed on Sep. 28, 2007 incorporated herein by reference.
[0028] Indicator fibers or yarns 11 can be provided in any of the strands of any of the strand layers. For example, as shown in FIG. 2 , one or more of the strands 7 of the outer strand layer 2 can include the fibers or yarns 11 , one or more of the strands 8 and 9 of the first inner strand layer strand layer 3 can include the fibers or yarns 11 , and one or more of the strands 10 of the second inner strand layer 4 can include the fibers or yarns 11 .
[0029] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
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A synthetic fiber rope can be used to the limit of failure by setting a sensitivity of detection of the state of wear of the rope. Strands of the rope have indicator fibers or indicator yarn that have a high probability of losing electrical conductivity and thereby indicate a worn cable. The indicator yarn consists of indicator fibers and of synthetic fibers, the indicator yarn fibers being inferior in relation to stress than the synthetic fibers of the strands.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This claims priority from U.S. provisional patent application Ser. No. 60/469,829 filed May 13, 2003 and European patent application No. 03076048.2 filed Apr. 10, 2003, both incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a wrought Al—Zn—Mg—Cu aluminium type (or 7000- or 7xxx-series aluminium alloys as designated by the Aluminum Association). More specifically, the present invention is related to an age-hardenable, high strength, high fracture toughness and highly corrosion resistant aluminium alloy and products made of that alloy. Products made from this alloy are very suitable for aerospace applications, but not limited to that. The alloy can be processed to various product forms, e.g. sheet, thin plate, thick plate, extruded or forged products.
[0003] In every product form, made from this alloy, property combinations can be achieved that are outperforming products made from nowadays known alloys. Because of the present invention, the uni-alloy concept can now be used also for aerospace applications. This will lead to significant cost reduction in the aerospace industry. Recycleability of the aluminium scrap produced during the production of the structural part or at the end of the life-cycle of the structural part will become significant easier because of the uni-alloy concept.
BACKGROUND OF THE INVENTION
[0004] Different types of aluminium alloys have been used in the past for forming a variety of products for structural applications in the aerospace industry. Designers and manufacturers in the aerospace industry are constantly trying to improve fuel efficiency, product performance and constantly trying to reduce the manufacturing and service costs. The preferred method for achieving the improvements, together with the cost reduction, is the uni-alloy concept, i.e. one aluminium alloy that is capable of having improved property balance in the relevant product forms.
[0005] The alloy members and temper designations used herein are in accordance with the well-known aluminium alloy product standards of the Aluminum Association. All percentages are in weight percents, unless otherwise indicated.
[0006] State of the art at this moment is high damage tolerant M2x24 (i.e. M2524) or AA6x13 or AA7x75 for fuselage sheet, AA2324 or M7x75 for lower wing, AA7055 or AA7449 for upper wing and M7050 or AA7010 or M7040 for wing spars and ribs or other sections machined from thick plate. The main reason for using different alloys for each different application is the difference in the property balance for optimum performance of the whole structural part.
[0007] For fuselage skin, damage tolerant properties under tensile loading are considered to be very important, that is a combination of fatigue crack growth rate (“FCGR”), plane stress fracture toughness and corrosion. Based on these property requirements, high damage tolerant AA2x24-T351 (see e.g. U.S. Pat. No. 5,213,639 or EP-1026270-A1) or Cu containing AA6xxx-T6 (see e.g. U.S. Pat. No. 4,589,932, U.S. Pat. No. 5,888,320, US-2002/0039664-A1 or EP-1143027-A1) would be the preferred choice of civilian aircraft manufacturers.
[0008] For lower wing skin a similar property balance is desired, but some toughness is allowably sacrificed for higher tensile strength. For this reason M2x24 in the T39 or a T8x temper are considered to be logical choices (see e.g. U.S. Pat. No. 5,865,914, U.S. Pat. No. 5,593,516 or EP-1114877-A1), although M7x75 in the same temper is sometimes also applied.
[0009] For upper wing, where compressive loading is more important than the tensile loading, the compressive strength, fatigue (SN-fatigue or life-time) and fracture toughness are the most critical properties. Currently, the preferred choice would be AA7150, AA7055, AA7449 or M7x75 (see e.g. U.S. Pat. No. 5,221,377, U.S. Pat. No. 5,865,911, U.S. Pat. No. 5,560,789 or U.S. Pat. No. 5,312,498). These alloys have high compressive yield strength with at the moment acceptable corrosion resistance and fracture toughness, although aircraft designers would welcome improvements on these property combinations.
[0010] For thick sections having a thickness of more than 3 inch or parts machined from such thick sections, a uniform and reliable property balance through thickness is important. Currently, M7050 or AA7010 or AA7040 (see U.S. Pat. No. 6,027,582) or C80A (see US-2002/0150498-A1) are used for these types of applications. Reduced quench sensitivity, that is deterioration of properties through thickness with lower quenching speed or thicker products, is a major wish from the aircraft manufactures. Especially the properties in the ST-direction are a major concern of the designers and manufactures of structural parts.
[0011] A better performance of the aircraft, i.e. reduced manufacturing cost and reduced operation cost, can be achieved by improving the property balance of the aluminium alloys used in the structural part and preferably using only one type of alloy to reduce the cost of the alloy and to reduce the cost in the recycling of aluminium scrap and waste.
[0012] Accordingly, it is believed that there is a demand for an aluminium alloy capable of achieving the improved proper property balance in every relevant product form.
SUMMARY OF INVENTION
[0013] The present invention is directed to an AA7xxx-series aluminium alloy having the capability of achieving a property balance in any relevant product that is better than property balance of the variety of commercial aluminium alloys (AA2xxx, AA6xxx, AA7xxx) nowadays used for those products.
[0014] A preferred composition of the alloy of the present invention comprises or consists essentially of, in weight %, about 6.5 to 9.5 zinc (Zn), about 1.2 to 2.2% magnesium (Mg), about 1.0 to 1.9% copper (Cu), about 0 to 0.5% zirconium (Zr), about 0 to 0.7% scandium (Sc), about 0 to 0.4% chromium (Cr), about 0 to 0.3% hafnium (Hf), about 0 to 0.4% titanium (Ti), about 0 to 0.8% manganese (Mn), the balance being aluminium (Al) and other incidental elements. Preferably (0.9Mg−0.6)≦Cu≦(0.9Mg+0.05).
[0015] A more preferred alloy composition according to the invention consists essentially of, in weight %, about 6.5 to 7.9% Zn, about 1.4 to 2.10% Mg, about 1.2 to 1.80% Cu, and preferably wherein (0.9Mg−0.5)≦Cu≦0.9Mg, about 0 to 0.5% Zr, about 0 to 0.7% Sc, about 0 to 0.4% Cr, about 0 to 0.3% Hf, about 0 to 0.4% Ti, about 0 to 0.8% Mn, the balance being Al and other incidental elements.
[0016] A more preferred alloy composition according to the invention consists essentially of, in weight %, about 6.5 to 7.9% Zn, about 1.4 to 1.95% Mg, about 1.2 to 1.75% Cu, and preferably wherein (0.9Mg−0.5)≦Cu≦(0.9Mg−0.1), about 0 to 0.5% Zr, about 0 to 0.7% Sc, about 0 to 0.4% Cr, about 0 to 0.3% Hf, about 0 to 0.4% Ti, about 0 to 0.8% Mn, the balance being aluminium and other incidental elements.
[0017] In a more preferred embodiment, the lower limit for the Zn-content is 6.7%, and more preferably 6.9%.
[0018] In a more preferred embodiment, the lower limit for the Mg-content of 1.90%, and more preferably 1.92%. This lower-limit for the Mg-content is in particular preferred when the alloy product is being used for sheet product, e.g. fuselage sheet, and when used for sections made from thick plate.
[0019] The above mentioned aluminium alloys may contain impurities or incidental or intentionally additions, such as for example at most 0.3% Fe, preferably at most 0.14% Fe, at most 0.2% silicon (Si), and preferably at most 0.12% Si, at most 1% silver (Ag), at most 1% germanium (Ge), at most 0.4% vanadium (V). The other additions are generally governed by the 0.05-0.15 weight % ranges as defined in the Aluminium Association, thus each unavoidable impurity in a range of <0.05%, and the total of impurities <0.15%.
[0020] The iron and silicon contents should be kept significantly low, for example not exceeding about 0.08% Fe and about 0.07% Si or less. In any event, it is conceivable that still slightly higher levels of both impurities, at most about 0.14% Fe and at most about 0.12% Si may be tolerated, though on a less preferred basis herein. In particular for the mould plates or tooling plates embodiments hereof, even higher levels of at most 0.3% Fe and at most 0.2% Si or less, are tolerable.
[0021] The dispersoid forming elements like for example Zr, Sc, Hf, Cr and Mn are added to control the grain structure and the quench sensitivity. The optimum levels of dispersoid formers do depend on the processing, but when one single chemistry of main elements (Zn, Cu and Mg) is chosen within the preferred window and that chemistry will be used for all relevant product forms, then Zr levels are preferably less than 0.11%.
[0022] A preferred maximum for the Zr level is a maximum of 0.15%. A suitable range of the Zr level is a range of 0.04 to 0.15%. A more preferred upper-limit for the Zr addition is 0.13%, and even more preferably not more than 0.11%.
[0023] The addition of Sc is preferably not more than 0.3%, and preferably not more than 0.18%. When combined with Sc, the sum of Sc+Zr should be less then 0.3%, preferably less than 0.2%, and more preferably at a maximum of 0.17%, in particular where the ratio of Zr and Sc is between 0.7 and 1.4.
[0024] Another dispersoid former that can be added, alone or with other dispersoid formers is Cr. Cr levels should be preferable below 0.3%, and more preferably at a maximum of 0.20%, and even more preferably 0.15%. When combined with Zr, the sum of Zr+Cr should not be above 0.20%, and preferably not more than 0.17%.
[0025] The preferred sum of Sc+Zr+Cr should not be above 0.4%, and more preferably not more than 0.27%.
[0026] Also Mn can be added alone or in combination with one of the other dispersoid formers. A preferred maximum for the Mn addition is 0.4%. A suitable range for the Mn addition is in the range of 0.05 to 0.40%, and preferably in the range of 0.05 to 0.30%, and even more preferably 0.12 to 0.30%. A preferred lower limit for the Mn addition is 0.12%, and more preferably 0.15%. When combined with Zr, the sum of Mn+Zr should be less then 0.4%, preferably less than 0.32%, and a suitable minimum is 0.14%.
[0027] In another embodiment of the aluminium alloy product according to the invention the alloy is free of Mn, in practical terms this would mean that the Mn-content is <0.02%, and preferably <0.01%, and more preferably the alloy is essentially free or substantially free from Mn. With “substantially free” and “essentially free” we mean that no purposeful addition of this alloying element was made to the composition, but that due to impurities and/or leaching from contact with manufacturing equipment, trace quantities of this element may, nevertheless, find their way into the final alloy product.
[0028] In a particular embodiment of the wrought alloy product according to this invention, the alloy consists essentially of, in weight percent:
Zn 7.2 to 7.7, and typically about 7.43 Mg 1.79 to 1.92, and typically about 1.83 Cu 1.43 to 1.52, and typically about 1.48 Zr or Cr 0.04 to 0.15, preferably 0.06 to 0.10, and typically 0.08 Mn optionally in a range of 0.05 to 0.19, and preferably 0.09 to 0.19, or in an alternative embodiment <0.02, preferably <0.01 Si <0.07, and typically about 0.04 Fe <0.08, and typically about 0.05 Ti <0.05, and typically about 0.01 balance aluminium and inevitable impurities each <0.05, total <0.15.
[0038] In another particular embodiment of the wrought alloy product according to this invention, the alloy consists essentially of, in weight percent:
Zn 7.2 to 7.7, and typically about 7.43 Mg 1.90 to 1.97, preferably 1.92 to 1.97, and typically about 1.94 Cu 1.43 to 1.52, and typically about 1.48 Zr or Cr 0.04 to 0.15, preferably 0.06 to 0.10, and typically 0.08 Mn optionally in a range of 0.05 to 0.19, and preferably of 0.09 to 0.19, or in an alternative embodiment <0.02, preferably <0.01 Si <0.07, and typically about 0.05 Fe <0.08, and typically about 0.06 Ti <0.05, and typically about 0.01 balance aluminium and inevitable impurities each <0.05, total <0.15.
[0048] The alloy product according to the invention can be prepared by conventional melting and may be (direct chill, D.C.) cast into ingot form. Grain refiners such as titanium boride or titanium carbide may also be used. After scalping and possible homogenisation, the ingots are further processed by, for example extrusion or forging or hot rolling in one or more stages. This processing may be interrupted for an inter-anneal. Further processing may be cold working, which may be cold rolling or stretching. The product is solution heat treated and quenched by immersion in or spraying with cold water or fast cooling to a temperature lower than 95° C. The product can be further processed, for example by rolling or stretching, for example at most 8%, or may be stress relieved by stretching or compression at most about 8%, for example, from about 1 to 3%, and/or aged to a final or intermediate temper. The product may be shaped or machined to the final or intermediate structure, before or after the final ageing or even before solution heat treatment.
DETAILED DESCRIPTION OF THE INVENTION
[0049] The design of commercial aircraft requires different sets of properties for different types of structural parts. An alloy when processed to various product forms (i.e., sheet, plate, thick plate, forging or extruded profile etc.) and to be used in a wide variety of structural parts with different loading sequences in service life and consequently meeting different material requirements for all those product forms, must be unprecedentedly versatile.
[0050] The important material properties for a fuselage sheet product are the damage tolerant properties under tensile loads (i.e. FCGR, fracture toughness and corrosion resistance).
[0051] The important material properties for a lower wing skin in a high capacity and commercial jet aircraft are similar to those for a fuselage sheet product, but typically a higher tensile strength is wished by the aircraft manufactures. Also fatigue life becomes a major material property.
[0052] Because the airplane flies at high altitude where it is cold, fracture toughness at minus 65° F. is a concern in new designs of commercial aircrafts. Additional desirable features include age formability whereby the material can be shaped during artificial aging, together with good corrosion performance in the areas of stress corrosion cracking resistance and exfoliation corrosion resistance.
[0053] The important material properties for an upper wing skin product are the properties under compressive loads, i.e. compressive yield strength, fatigue life and corrosion resistance.
[0054] The important material properties for machined parts from thick plate depend on the machined part. But, in general, the gradient in material properties through thickness must be very small and the material properties like strength, fracture toughness, fatigue and corrosion resistance must be a high level.
[0055] The present invention is directed at an alloy composition when processed to a variety of products, such as, but not limited to, sheet, plate, thick plate etc, will meet or exceed the desired material properties. The property balance of the product will out-perform the property balance of the product made from nowadays commercially used alloys.
[0056] It has been found very surprisingly a chemistry window within the AA7000 window, unexplored before, that does fulfil this unique capability.
[0057] The present invention resulted from an investigation on the effect of Cu, Mg and Zn levels, combined with various levels and types of dispersoid former (e.g. Zr, Cr, Sc, Mn) on the phases formed during processing. Some of these alloys were processed to sheet and plate and tested on tensile, Kahn-tear toughness and corrosion resistance. Interpretations of these results lead to the surprising insight that an aluminium alloy with a chemical composition within a certain window, will exhibit excellent properties as well as for sheet as for plate as for thick plate as for extrusions as for forgings.
[0058] In another aspect of the invention there is provided a method of manufacturing the aluminium alloy product according to the invention. The method of manufacturing a high-strength, high-toughness AA7000-series alloy product having a good corrosion resistance, comprising the processing steps of:
a.) casting an ingot having a composition as set out in the present description; b.) homogenising and/or pre-heating the ingot after casting; c.) hot working the ingot into a pre-worked product by one or more methods selected from the group consisting of: rolling, extruding and forging; d.) optional reheating the pre-worked product and either, e.) hot working and/or cold working to a desired workpiece form; f.) solution heat treating (SHT) the formed workpiece at a temperature and time sufficient to place into solid solution essentially all soluble constituents in the alloy; g.) quenching the solution heat treated workpiece by one of spray quenching or immersion quenching in water or other quenching media; h.) optionally stretching or compressing of the quenched work piece or otherwise cold worked to relieve stresses, for example levelling of sheet products; i.) artificially ageing the quenched and optionally stretched or compressed workpiece to achieve a desired temper, for example, the tempers selected from the group comprising: T6, T74, T76, T751, T7451, T7651, T77 and T79.
[0068] The alloy products of the present invention are conventionally prepared by melting and may be direct chill (D.C.) cast into ingots or other suitable casting techniques. Homogenisation treatment is typically carried out in one or multi steps, each step having a temperature preferably in the range of 460 to 490° C. The pre-heat temperature involves heating the rolling ingot to the hot-mill entry temperature, which is typically in a temperature range of 400 to 460° C. Hot working the alloy product can be done by one or more methods selected from the group consisting of rolling, extruding and forging. For the present alloy hot rolling is being preferred. Solution heat treatment is typically carried out in the same temperature range as used for homogenisation, although the soaking times can be chosen somewhat shorter.
[0069] In an embodiment of the method according to the invention the artificial ageing step i.) comprises a first ageing step at a temperature in a range of 105° C. to 135° C. preferably for 2 to 20 hours, and a second ageing step at a temperature in a range of 135° C. to 210° C. preferably for 4 to 20 hours. In a further embodiment a third ageing step may be applied at a temperature in a range of 105° C. to 135° C. and preferably for 20 to 30 hours.
[0070] A surprisingly excellent property balance is being obtained in whatever thickness is produced. In the sheet thickness range of at most 1.5 inch the properties will be excellent for fuselage sheet, and preferably the thickness is at most 1 inch. In the thin plate thickness range of 0.7 to 3 inch the properties will be excellent for wing plate, e.g. lower wing plate. The thin plate thickness range can be used also for stringers or to form an integral wing panel and stringer for use in an aircraft wing structure. More peak-aged material will give an excellent upper wing plate, whereas slightly more over-ageing will give excellent properties for lower wing plate. When processed to thicker gauges of more than 2.5 inch up to about 11 inch or more excellent properties will be obtained for integral parts machined from plates, or to form an integral spar for use in an aircraft wing structure, or in the form of a rib for use in an aircraft wing structure. The thicker gauge products can be used also as tooling plate or mould plate, e.g. moulds for manufacturing formed plastic products, for example via die-casting or injection moulding. When thickness ranges are given hereinabove, it will be immediately apparent to the skilled person that this is the thickness of the thickest cross sectional point in the alloy product made from such a sheet, thin plate or thick plate. The alloy products according to the invention can also be provided in the form of a stepped extrusion or extruded spar for use in an aircraft structure, or in the form of a forged spar for use in an aircraft wing structure. Surprisingly, all these products with excellent properties can be obtained from one alloy with one single chemistry.
[0071] In the embodiment whereby structural components, e.g. ribs, are made from the alloy product according to the invention having a thickness of 2.5 inch or more, the component increased elongation compared to its AA7050 aluminium alloy counterpart. In particular the elongation (or A50) in the ST testing direction is 5% or more, and in the best results 5.5% or more.
[0072] Furthermore, in the embodiment whereby structural components are made from the alloy product according to the invention having a thickness of 2.5 inch or more, the component has a fracture toughness Kapp in the L-T testing direction at ambient room temperature and when measured at S/4 according to ASTM E561 using 16-inch centre cracked panels (M(T) or CC(T)) showing an at least 20% improvement compared to its M7050 aluminium alloy counterpart, and in the best examples an improvement of 25% or more is found.
[0073] In the embodiment where the alloy product has been extruded, preferably the alloy products have been extruded into profiles having at their thickest cross sectional point a thickness in the range of up to 10 mm, and preferably in the range of 1 to 7 mm. However, in extruded form the alloy product can also replace thick plate material which is conventionally machined via high-speed machining or milling techniques into a shaped structural component. In this embodiment the extruded alloy product has preferably at its thickest cross sectional point a thickness in a range of 2 to 6 inches.
BRIEF DESCRIPTION OF THE DRAWINGS
[0074] FIG. 1 is an Mg—Cu diagram setting out the Cu—Mg range for the alloy according to this invention, together with narrower preferred ranges;
[0075] FIG. 2 is a diagram comparing the fracture toughness vs. the tensile yield strength for the alloy product according to the invention against several references;
[0076] FIG. 3 is a diagram comparing the fracture toughness vs. the tensile yield strength for the alloy product according to this invention in a 30 mm gauge against two references;
[0077] FIG. 4 is a diagram comparing the plane strain fracture toughness vs. the tensile yield strength for the alloy products according to the invention using different processing routes.
[0078] FIG. 1 shows schematically the ranges for the Cu and Mg for the alloy according to the present invention in their preferred embodiments as set out in dependent claims 2 to 4 . Also shown are two narrower more preferred ranges.
[0079] The ranges can also be identified by using the corner-points A, B, C, D, E, and F of a hexagon box. Preferred ranges are identified by A′ to F′, and more preferred ranges by A″ to F″. The coordinates are listed in Table 1. In FIG. 1 also the alloy composition according to this invention as mentioned in the examples hereinafter are illustrated as individual points.
TABLE 1 Coordinates (in wt. %) for the corner-points of the Cu—Mg ranges for the preferred ranges of the alloy product according to the invention. (Mg, Cu) (Mg, Cu) more Corner (Mg, Cu) Corner preferred Corner preferred point wide range point range point range A 1.20, 1.00 A′ 1.40, 1.10 A″ 1.40, 1.10 B 1.20, 1.13 B′ 1.40, 1.26 B″ 1.40, 1.16 C 2.05, 1.90 C′ 2.05, 1.80 C″ 2.05, 1.75 D 2.20, 1.90 D′ 2.10, 1.80 D″ 2.10, 1.75 E 2.20, 1.40 E′ 2.10, 1.40 E″ 2.10, 1.40 F 1.77, 1.00 F′ 1.78, 1.10 F″ 1.87, 1.10
EXAMPLES
Example 1
[0080] On a laboratory scale alloys were cast to prove the principle of the current invention and processed to 4.0 mm sheet or 30 mm plate. The alloy compositions are listed in Table 2, for all ingots Fe <0.06, Si <0.04, Ti 0.01, balance aluminium. Rolling blocks of approximately 80 by 80 by 100 mm (height×width×length) were sawn from round lab cast ingots of about 12 kg. The ingots were homogenised at 460±5° C. for about 12 hrs and consequently at 475±5° C. for about 24 hrs and consequently slowly air cooled to mimic an industrial homogenisation process. The rolling ingots were pre-heated for about 6 hrs at 410±5° C. At an intermediate thickness range of about 40 to 50 mm the blocks were re-heated at 410±5° C. Some blocks were hot rolled to the final gauge of 30 mm, others were hot rolled to a final gauge of 4.0 mm. During the whole hot-rolling process, care was taken to mimic an industrial scale hot rolling. The hot-rolled products were solution heat treated and quenched. Most were quenched in water, but some were also quenched in oil to mimic the mid and quarter-thickness quenching-rate of a 6-inch thick plate. The products were cold stretched by about 1.5% to relieve the residual stresses. The ageing behaviour of the alloys was investigated. The final products were over-aged to a near peak aged strength (e.g. T76 or T77 temper).
[0081] Tensile properties have been tested according EN10.002. The tensile specimens from the 4 mm thick sheet were flat EURO-NORM specimen with 4 mm thickness. The tensile specimens from the 30 mm plate were round tensile specimens taken from mid-thickness. The tensile test results in Table 1 are from the L-direction. The Kahn-tear toughness is tested according to ASTM B871-96. The test direction of the results on Table 2 is the T-L direction. The so-called notch-toughness can be obtained by dividing the tear-strength, obtained by the Kahn-tear test, by the tensile yield strength (“TS/Rp”). This typical result from the Kahn-tear test is known in the art to be a good indicator for true fracture toughness. The unit propagation energy (“UPE”), also obtained by the Kahn-tear test, is the energy needed for crack growth. It is believed that the higher the UPE, the more difficult to grow the crack, which is a desired feature of the material.
[0082] To qualify for a good corrosion performance, the exfoliation corrosion resistance (“EXCO”) when measured according to ASTM G34-97 must be at least “EA” or better. The inter-granular corrosion (“IGC”) when measured according MIL-H-6088 is preferable absent. Some pitting is acceptable, but preferably should be absent also.
[0083] In order to have a promising candidate alloy suitable for a variety of products, it had to fulfil the following requirements on lab-scale: A tensile yield strength of at least 510 MPa, an ultimate strength of at least 560 MPa, a notch toughness of at least 1.5 and a UPE of at least 200 kJ/m 2 . The results for the various alloys as function of some processing are listed in Table 2 also.
[0084] In order to meet all those desired material properties, the chemistry of the alloy has to be carefully balanced. According to the present results, too high values for Cu, Mg and Zn contents were found to be detrimental to toughness and corrosion resistance. Whereas too low values were found to be detrimental for high strength levels.
TABLE 2 Invention Specimen Alloy Thickness Mg Cu Zn Zr Others No. (Y/N) (mm) Temper (wt %) (wt %) (wt %) (wt %) (wt %) 1 yes 30 T77 1.84 1.47 7.4 0.10 — 2 yes 30 T76 1.66 1.27 8.1 0.09 — 3 yes 4 T76 2.00 1.54 6.8 0.11 — 4 no 4 T76 2.00 1.52 5.6 0.01 0.16 Cr 5 no 4 T76 2.00 1.53 5.6 0.06 0.08 Cr 6 yes 4 T76 1.82 1.68 7.4 0.10 — 7 yes 30 T76 2.09 1.30 8.2 0.09 — 8 yes 4 T77 2.20 1.70 8.7 0.11 — 9 yes 4 T77 1.81 1.69 8.7 0.10 — 10 no 4 T76 2.10 1.54 5.6 0.07 — 11 no 4 T76 2.20 1.90 6.7 0.10 — 12 no 4 T76 1.98 1.90 6.8 0.09 — 13 no 4 T77 2.10 2.10 8.6 0.10 — 14 no 4 T77 2.50 1.70 8.7 0.10 — 15 no 4 T77 1.70 2.10 8.6 0.12 — 16 no 4 T77 1.70 2.40 8.6 0.11 — 17 no 4 T76 2.40 1.54 5.6 0.01 — 18 no 4 T76 2.30 1.54 5.6 0.07 — 19 no 4 T76 2.30 1.52 5.5 0.14 — 20 yes 4 T76 2.19 1.54 6.7 0.11 0.16 Mn 21 no 4 T76 2.12 1.51 5.6 0.12 — Invention Specimen Alloy Rp Rm UPE No. (Y/N) (MPa) (MPa) (kJ/m 2 ) Ts/Rp 1 yes 587 627 312 1.53 2 yes 530 556 259 1.76 3 yes 517 563 297 1.62 4 no 473 528 232 1.45 5 no 464 529 212 1.59 6 yes 594 617 224 1.44 7 yes 562 590 304 1.64 8 yes 614 626 115 1.38 9 yes 574 594 200 1.47 10 no 490 535 245 1.53 11 no 563 608 — 1.07 12 no 559 592 — 1.32 13 no 623 639 159 1.31 14 no 627 643 117 1.33 15 no 584 605 139 1.44 16 no 598 619 151 1.42 17 no 476 530 64 1.42 18 no 488 542 52 1.54 19 no 496 543 155 1.66 20 yes 521 571 241 1.65 21 no 471 516 178 1.42
[0085] But, very surprisingly, a higher Zn-level is increasing the toughness and crack growth resistance. Therefore, it is desirable to use higher Zn level and combine these with lower Mg and Cu levels. It has been found that the Zn-content should not be below 6.5%, and preferably not below 6.7%, and more preferably not below 6.9%.
[0086] Mg is required to have acceptable strength levels. It has been found that a ratio of Mg/Zn of about 0.27 or lower seems to give the best strength-toughness combination. However, Mg levels should not exceed 2.2%, and preferably not exceed 2.1%, and even more preferably not exceed 1.97%, with a more preferred upper level of 1.95%. This upper-limit is lower than in the conventional AA-windows or ranges of presently used commercial aerospace alloys like M7050, AA7010 and M7075.
[0087] In order to have a desirably very high crack growth resistance (or UPE) Mg levels must be carefully balanced and should preferably be in the same order or slightly more than the Cu levels, and preferably (0.9×Mg−0.6)≦Cu≦(0.9×Mg+0.05). The Cu-content should not be too high. It has been found that the Cu-content should not be higher than 1.9%, and preferably should not exceed 1.80%, and more preferably not exceed 1.75%.
[0088] The dispersoid formers used in M7xxx-series alloys are typically Cr, as in e.g. AA7x75, or Zr, as in e.g. M7x50 and AA7x10. Conventionally, Mn is believed to be detrimental for toughness, but much to our surprise, a combination of Mn and Zr shows still a very good strength-toughness balance.
Example 2
[0089] A batch of full-size rolling ingots with a thickness of 440 mm thick on an industrial scale were produced by a DC-casting and having the chemical composition (in wt. %): 7.43% Zn, 1.83% Mg, 1.48% Cu, 0.08% Zr, 0.02% Si and 0.04% Fe, balance aluminium and unavoidable impurities. One of these ingots was scalped, homogenised at 12 hrs/470° C.+24 hrs/475° C.+air cooled to ambient temperature. This ingot was pre-heated at 8 hrs/410° C. and then hot rolled to about 65 mm. The rolling block was then turned 90 degrees and further hot rolled to about 10 mm. Finally the rolling block was cold rolled to a gauge of 5.0 mm. The obtained sheet was solution heat treated at 475° C. for about 40 minutes, followed by water-spray quenching. The resultant sheets were stress relieved by a cold stretching operation of about 1.8%. Two ageing variants have been produced, variant A: for 5 hrs/120° C.+9 hrs/155° C., and variant B: for 5 hrs/120° C.+9 hrs/165° C.
[0090] The tensile results have been measured according to EN 10.002. The compression yield strength (“CYS”) has been measured according to ASTM E9-89a. The shear strength has been measured according to ASTM B831-93. The fracture toughness, Kapp, has been measured according to ASTM E561-98 on 16-inch wide centre cracked panels [M(T) or CC(T)]. The Kapp has been measured at ambient room temperature (RT) and at −65° F. As reference material a high damage tolerant (“HDT”) AA2x24-T351 has been tested as well. The results are listed in Table 3.
TABLE 3 L-TYS LT-TYS L-UTS LT-UTS L-T CYS T-L CYS Ageing (MPa) (MPa) (MPa) (MPa) (MPa) (MPa) INV Variant A 544 534 562 559 554 553 INV Variant A 489 472 526 512 492 500 HDT- T351 360 332 471 452 329 339 2 × 24 L-T T-L RT RT −65° F. −65° F. Shear Shear L-T Kapp T-L Kapp L-T Kapp L-T Kapp Ageing (MPa) (MPa) MPa · m MPa · m 0.5 MPa · m 0.5 MPa · m 0.5 INV Variant A 372 373 103 100 — — INV Variant B 340 338 132 127 102 103 HDT- T351 328 312 — 101 — 103 2 × 24
[0091] The exfoliation corrosion resistance has been measured according ASTM G34-97. Both variant A and B showed EA rating.
[0092] The inter-granular corrosion measured according to MIL-H-6088 for variant A was about 70 μm and for variant B about 45 μm. Both are significantly lower than the typical 200 μm as measured for the reference AA2x24-T351.
[0093] From Table 3 it can be seen that there is a significant improvement with the alloy according to the invention. A significant increase in strength at comparable or even higher fracture toughness levels. Also the alloy according to the invention at a low temperature of minus 65° F., outperforms the nowadays standard high damage tolerant fuselage alloy AA2x24-T351. Note that also the corrosion resistance of the inventive alloy is significant better than the AA2x24-T351.
[0094] The fatigue crack growth rate (“FCGR”) has been measured according to ASTM E647-99 on 4-inch wide compact tension panels [C(T)] with an R-ratio of 0.1. In Table 3 the da/dn per cycle at a stress range of ΔK=27.5 ksi.in 0.5 (=about 30 MPa.m 0.5 ) of the inventive alloy has been compared with the reference high damage tolerant AA2x24-T351.
[0095] It can be clearly seen from the results in Table 4 that the crack growth of the inventive alloy is better than that of the high damage tolerant AA2x24-T351.
TABLE 4 Crack growth per cycle at a stress range of deltaK = 27.5 ksi in 0.5 INV Variant A L-T 96% INV Variant A T-L 84% INV Variant B L-T 73% INV Variant B T-L 74% HDT-2x24 T351 L-T 100%
Example 3
[0096] Another full-scale ingot taken from the batch DC-cast from Example 2 was produced into a plate of 6-inch thickness. Also this ingot was scalped, homogenised at 12 hrs/470° C.+24 hrs/475° C.+air cooled to ambient temperature. The ingot was pre-heated at 8 hrs/410° C. and then hot rolled to about 152 mm. The obtained hot-rolled plate was solution heat treated at 475° C. for about 7 hours followed by water-spray quenching. The plates were stress relieved by a cold stretching operation of about 2.0%. Several different two-step ageing processes have been applied.
[0097] The tensile results have been measured according to EN 10.002. The specimens were taken from the T/4-position. The plane strain fracture toughness, Kq, has been measured according to ASTM E399-90. If the validity requirements as given in ASTM E399-90 are met, these Kq values are a real material property and called K 1C . The K1c has been measured at ambient room temperature (“RT”). The exfoliation corrosion resistance has been measured according to ASTM G34-97. The results are listed in Table 5. All ageing variants as shown in Table 5 showed “EA” rating.
[0098] In FIG. 2 a comparison is given versus results presented in US-2002/0150498-A1, Table 2, incorporated herein by reference. In this US patent application an example (example 1) is given of a similar product, but with a different chemistry that is stated to be optimised for quench sensitivity. In our inventive alloy we have obtained a similar tensile versus toughness balance as in this US patent application. However, our inventive alloys shows at least superior EXCO resistance.
[0099] Furthermore, also the elongation of our inventive alloy is superior to that disclosed in U.S. 2002/0150498-A1, Table 2. The overall property balance of alloy according to the present invention when processed to 6-inch thick plate is better than that disclosed in US-2002/0150498-A1. In FIG. 2 also documented data for thick gauges of 75 to 220 mm are shown for the M7050/7010 alloy (see AIMS 03-02-022, December 2001), the M7050/7040 alloy (see AIMS 03-02-019, September 2001), and the M7085 alloy (see AIMS 03-02-025, September 2002).
TABLE 5 L-TYS L-UTS L-A50 L-T K1C Ageing process (MPa) (MPa) (%) (MPa · m 0.5 ) EXCO 5 hrs/120° C. + 453 497 9.9 — EA 11 hrs/165° C. 5 hrs/120° C. + 444 492 12.5 44.4 EA 13 hrs/165° C. 5 hrs/120° C. + 434 485 13.0 45.0 EA 15 hrs/165° C. 5 hrs/120° C. + 494 523 10.5 39.1 EA 12 hrs/160° C. 5 hrs/120° C. + 479 213 8.3 — EA 14 hrs/160° C.
Example 4
[0100] Another full-scale ingot taken from the batch DC-cast from Example 2 was produced to plates of respectively 63.5 mm and 30 mm thickness. The cast ingot was scalped, homogenised at 12 hrs/470° C.+24 hrs/475° C.+air cooled to ambient temperature. The ingot was pre-heated at 8 hrs/410° C. and then hot rolled to respectively 63.5 and 30 mm. The obtained hot-rolled plates were solution heat treated (SHT) at 475° C. for about 2 to 4 hrs followed by water-spray quenching. The plates were stress relieved by a cold stretching operation of respectively 1.7% and 2.1% for the 63.5 mm and 30 mm plates. Several different two-step ageing processes have been applied.
[0101] The tensile results have been measured according to EN 10.002. The plane strain fracture toughness, Kq, has been measured according to ASTM E399-90 on CT-specimens. If the validity requirements as given in ASTM E399-90 are met, these Kq values are a real material property and called K 1C . The K 1C has been measured at ambient room temperature (“RT”). The EXCO exfoliation corrosion resistance has been measured according to ASTM G34-97. The results are listed in Table 6. All ageing variants as shown in Table 6 showed “EA”-rating.
TABLE 6 TYS UTS A50 TYS UTS A50 Thickness Ageing MPa MPa (%) L-T K1C (MPa) (MPa) (%) T-L K1C (mm) (° C.-hrs) L-direction MPa · vm LT-direction MPa · m 0.5 63.5 120-5/ 566 594 10.7 42.4 532 572 9.8 32.8 150-12 63.5 120-5/ 566 599 11.9 40.7 521 561 11.2 33.0 155-12 63.5 120-5/ 528 569 13.0 51.6 497 516 11.6 40.2 160-12 30 120-5/ 565 590 14.2 46.9 558 582 13.9 36.3 150-12 30 120-5/ 557 589 14.4 51.0 547 572 13.6 39.2 155-12 30 120-5/ 501 548 15.1 65.0 493 539 14.3 46.8 160-12
[0102] In Table 7 the values are given of nowadays state of the art commercial upper wing alloys, and are typical data according to the supplier of that material (Alloy 7150-T7751 plate & 7150-T77511 extrusions, Alcoa Mill products, Inc., ACRP-069-B).
TABLE 7 Typical values from ALCOA tech sheet on AA7150-T77 and AA7055-T77, both plates of 25 mm. TYS UTS A50 TYS UTS A50 Thickness MPa MPa (%) L-T KIC (MPa) (MPa) (%) T-L KIC (mm) Ageing L-direction MPa · m 0.5 LT-direction MPa · m 0.5 25 7150-T77 572 607 12.0 29.7 565 607 11.0 26.4 25 7055-T77 614 634 11.0 28.6 614 641 10.0 26.4
[0103] In FIG. 3 a comparison is given of the inventive alloy versus AA7150-T77 and AA7055-T77. From FIG. 3 it can be clearly seen that the tensile versus toughness balance of the current inventive alloy is superior to commercial available AA7150-T77 and also to AA7055-T77.
Example 5
[0104] Another full-scale ingot taken from the batch DC-cast from Example 2 (hereinafter in Example 5 “Alloy A”) was produced to plates of 20 mm thickness. Also one other casting was made (designated “Alloy B” for this example) with a chemical composition (in wt. %): 7.39% Zn, 1.66% Mg, 1.59% Cu, 0.08% Zr, 0.03% Si and 0.04% Fe, balance aluminium and unavoidable impurities. These ingots were scalped, homogenised at 12 hrs/470° C.+24 hrs/475° C.+air cooled to ambient temperature. For further processing, three different routes were used.
Route 1: The ingots of alloy A and B were pre-heated at 6 hrs/420° C. and then hot rolled to about 20 mm. Route 2: Ingot of alloy A were pre-heated at 6 hrs/460° C. and then hot rolled to about 20 mm Route 3: Ingot of alloy B were pre-heated at 6 hrs/420° C. and then hot rolled to about 24 mm, subsequently these plates were cold rolled to 20 mm.
[0108] Thus, four variants were produced and identified as: A1, A2, B1 and B3. The resultant plates were solution heat treated at 475° C. for about 2 to 4 hrs followed by water-spray quenching. The plates were stress relieved by a cold stretching operation of about 2.1%. Several different two-step ageing processes have been applied, whereby for example “120-5/150-10” means 5 hrs at 120° C. followed by 10 hrs at 150° C.
[0109] The tensile results have been measured according to EN 10.002. The plane strain fracture toughness, Kq, has been measured according to ASTM E399-90 on CT specimens. If the validity requirements as given in ASTM E399-90 are met, these Kq values are a real material property and called K 1C or KIC. Note that most of the fracture toughness measurement in this example failed the meet the validity criteria on specimen thickness. The reported Kq values are a conservative with respect to K 1C , in other words, the reported Kq values are in fact generally lower than the standard K 1C values obtained when specimen size related validity criteria of ASTM E399-90 are satisfied. The exfoliation corrosion resistance has been measured according to ASTM G34-97. The results are listed in Table 8. All ageing variants as shown in Table 8 showed “EA”-rating for the EXCO resistance.
[0110] The results of Table 8 have are shown graphically in FIG. 4 . In FIG. 4 lines have been fitted through the data to get an impression of the differences between A1, A2, B1 and B3. From that graph it can be clearly seen that alloy A and B, when comparing A1 and B1, have a similar strength versus toughness behaviour. The best strength versus toughness could be obtained by either B3 (i.e. cold rolling to final thickness) or by A2 (i.e. pre-heat at a higher temperature). Also note that the results of Table 8 show a significant better strength versus toughness balance than M7150-T77 and M7055-T77 as listed in Table 7.
TABLE 8 T-L TYS UTS A50 TYS UTS A50 KIC Ageing MPa (MPa) (%) MPa MPa (%) MPa · Alloy (° C.-hrs) L-direction LT-direction m 0.5 B3 120-5/ 563 586 13.7 548 581 12.5 38.4 150-10 B3 120-5/ 558 581 14.4 538 575 13.1 38.7 155-12 B3 120-5/ 529 563 14.6 517 537 13.7 40.3 160-10 B1 120-5/ 571 595 13.4 549 581 13.4 36.5 150-10 B1 120-5/ 552 582 14.3 528 568 13.9 37.1 155-12 B1 120-5/ 510 552 15.1 493 542 14.5 39.4 160-12 A1 120-5/ 574 597 13.7 555 590 14.0 33.7 150-10 A1 120-5/ 562 594 14.4 548 586 13.9 37.1 155-12 A1 120-5/ 511 556 15.0 502 550 14.3 37.6 160-12 A2 120-5/ 574 600 14.0 555 595 13.9 36.7 150-10 A2 120-5/ 552 584 14.3 541 582 13.1 38.0 155-12 A2 120-5/ 532 572 14.8 527 545 12.4 39.8 160-12
Example 6
[0111] On an industrial scale two alloys have been cast via DC-casting with a thickness of 440 mm and processed into sheet product of 4 mm. The alloy compositions are listed in Table 9, whereby alloy B represents an alloy composition according to a preferred embodiment of the invention when the alloy product is in the form of a sheet product.
[0112] The ingots were scalped, homogenized at 12 hrs/470° C.+24 hrs/475° C. and then hot rolled to an intermediate gauge of 65 mm and final hot rolled to about 9 mm. Finally the hot rolled intermediate products have been cold rolled to a gauge of 4 mm. The obtained sheet products were solution heat treated at 475° C. for about 20 minutes, followed by water-spray quenching. The resultant sheets were stress relieved by a cold stretching operation of about 2%. The stretched sheets have been aged thereafter for 5 hrs/120° C.+8 hrs/165° C. Mechanical properties have tested analogue to Example 1 and the results are listed in Table 10.
[0113] The results of this full-scale trial confirm the results of Example 1 that the positive addition of Mn in the defined range significantly improves the toughness (both UPE and Ts/Rp) of the sheet product resulting in a very good and desirable strength-toughness balance.
TABLE 9 Chemical composition of the alloys tested, balance impurities and aluminium Alloy Si Fe Cu Mn Mg Zn Ti Zr A 0.03 0.08 1.61 — 1.86 7.4 0.03 0.08 B 0.03 0.06 1.59 0.07 1.96 7.36 0.03 0.09
[0114]
TABLE 10
Mechanical properties of the alloy products tested for two testing directions.
L-direction
LT-direction
Rp
Rm
A50
Ts/
Rp
A50
Ts/
Alloy
MPa
MPa
(%)
TS
UPE
Rp
MPa
Rm
(%)
TS
UPE
Rp
A
497
534
11.0
694
90
1.40
479
526
12.0
712
134
1.49
B
480
527
12.9
756
152
1.58
477
525
12.8
712
145
1.49
Example 7
[0115] On an industrial scale two alloys have been cast via DC-casting with a thickness of 440 mm and processed into a plate product having a thickness of 152 mm. The alloy compositions are listed in Table 11, whereby alloy C represents a typical alloy falling within the M7050-series range and alloy D represents an alloy composition according to a preferred embodiment of the invention when the alloy product is in the form of plate, e.g. thick plate.
[0116] The ingots were scalped, homogenized in a two-step cycle of 12 hrs/470° C.+24 hrs/475° C. and air cooled to ambient temperature. The ingot was pre-heated at 8 hrs/410° C. and then hot rolled to final gauge. The obtained plate products were solution heat treated at 475° C. for about 6 hours, followed by water-spray quenching. The resultant plates were stretched by a cold stretching operation for about 2%. The stretched plates have been aged using a two-step ageing practice of first 5 hrs/120° C. followed by 12 hrs/165° C. Mechanical properties have been tested analogue to Example 3 in three test directions and the results are listed in Table 12 and 13. The specimens were taken from S/4 position from the plate for the L- and LT-testing direction and at S/2 for the ST-testing direction The Kapp has been measured at S/2 and S/4 locations in the L-T direction using panels having a width of 160 mm centre cracked panels and having a thickness of 6.3 mm after milling. These Kapp measurements have been carried out at room temperature in accordance with ASTM E561. The designation “ok” for the SCC means that no failure occurred at 180 MPa/45 days.
[0117] From the results of Tables 12 and 13 it can be seen that the alloy according to the invention in comparison with AA7050 has similar corrosion performance, the strength (yield strength and tensile strength) are comparable or slightly better than AA7050, in particular in the ST-direction. But more importantly the alloy of the present invention shown significantly better results in elongation (or A50) in the ST-direction. The elongation (or A50), in particular the elongation in ST-direction, is an important engineering parameter of amongst others ribs for use in an aircraft wing structure. The alloy product according to the invention further shows a significant improvement in fracture toughness (both Kic and Kapp).
TABLE 11 Chemical composition of the alloys tested, balance impurities and aluminium. Alloy Si Fe Cu Mn Mg Zn Ti Zr C 0.02 0.04 2.14 — 2.04 6.12 0.02 0.09 D 0.03 0.05 1.58 0.07 1.96 7.35 0.03 0.09
[0118]
TABLE 12
Tensile test results of the plate products for three testing directions.
TYS
TYS
TYS
UTS
UTS
UTS
Elong
Elong
Elong.
Alloy
(MPa)
(MPa)
(MPa)
(MPa)
(MPa)
(MPa)
(%)
(%)
(%)
L
LT
ST
L
LT
ST
L
LT
ST
C
483
472
440
528
537
513
9.0
7.3
3.3
D
496
486
460
531
542
526
9.2
8.0
5.8
[0119]
TABLE 13
Further properties of the plate products tested.
L-T KIC
T-L KIC
S-L KIC
L-T Kapp
Alloy
(MPa.m 0.5)
(MPa.m 0.5)
(MPa.m 0.5)
(MPa.m 0.5)
EXCO
SCC
C
27.8
26.3
26.2
45.8(s/4)
52(s/2)
EA
ok
D
30.3
29.4
29.1
62.6(s/4)
78.1(s/2)
EA
ok
Example 8
[0120] On an industrial scale two alloys have been cast via DC-casting with a thickness of 440 mm and processed into a plate product having a thickness of 63.5 mm. The alloy compositions are listed in Table 14, whereby alloy F represents an alloy composition according to a preferred embodiment of the invention when the alloy product is in the form of plate for wings.
[0121] The ingots were scalped, homogenized in a two-step cycle of 12 hrs/470° C.+24 hrs/475° C. and air cooled to ambient temperature. The ingot was pre-heated at 8 hrs/410° C. and then hot rolled to final gauge. The obtained plate products were solution heat treated at 475° C. for about 4 hours, followed by water-spray quenching. The resultant plates were stretched by a cold stretching operation for about 2%. The stretched plates have been aged using a two-step ageing practice of first 5 hrs/120° C. followed by 10 hrs/155° C.
[0122] Mechanical properties have been tested analogue to Example 3 in three test directions are listed in Table 15. The specimens were taken from T/2 position. Both alloys had a EXCO test result of “EB”.
[0123] From the results of Table 15 it can be seen that the positive addition of Mn results in an increase of the tensile properties. But most importantly the properties, and in particular the elongation (or A50), in the ST-direction are significantly improved. The elongation (or A50) in the ST-direction is an important engineering parameter for structural parts of an aircraft, e.g. wing plate material.
TABLE 14 Chemical composition of the alloys tested, balance impurities and aluminium. Alloy Si Fe Cu Mn Mg Zn Ti Zr E 0.02 0.04 1.49 — 1.81 7.4 0.03 0.08 F 0.03 0.05 1.58 0.07 1.95 7.4 0.03 0.09
[0124]
TABLE 15
Mechanical properties of the products tested for three testing
directions.
L-direction
LT-direction
ST-direction
TYS
UTS
Elong.
TYS
UTS
Elong.
TYS
UTS
Elong.
Alloy
(MPa)
(MPa)
(%)
(MPa)
(MPa)
(%)
(MPa)
(MPa)
(%)
E
566
599
12
521
561
11
493
565
5.3
F
569
602
13
536
573
9.5
520
586
8.1
[0125] Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made without departing from the spirit or scope of the invention as hereon described.
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An Al—Zn—Mg—Cu alloy with improved damage tolerance-strength combination properties. The present invention relates to an aluminium alloy product comprising or consisting essentially of, in weight %, about 6.5 to 9.5 zinc (Zn), about 1.2 to 2.2% magnesium (Mg), about 1.0 to 1.9% copper (Cu), preferable (0.9Mg−0.6)≦Cu≦(0.9Mg+0.05), about 0 to 0.5% zirconium (Zr), about 0 to 0.7% scandium (Sc), about 0 to 0.4% chromium (Cr), about 0 to 0.3% hafnium (Hf), about 0 to 0.4% titanium (Ti), about 0 to 0.8% manganese (Mn), the balance being aluminium (Al) and other incidental elements. The invention relates also to a method of manufacturing such as alloy.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/208,541, filed Feb. 25, 2009, U.S. Provisional Application Ser. No. 61/269,944, filed Jul. 1, 2009, U.S. Provisional Application Ser. No. 61/271,364 filed Jul. 20, 2009, and U.S. Provisional Application Ser. No. 61/279,293, filed Oct. 19, 2009, which are herein incorporated in their entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention is directed to compositions of (a) bendamustine, (b) a charged cyclopolysaccharide, and (c) a stabilizing agent.
BACKGROUND OF THE INVENTION
[0003] Bendamustine, 4-[5-[bis(2-chloroethyl)amino]-1-methylbenzimidazol-2-yl]butanoic acid, is used in the treatment of leukemia and certain lymphomas. However, this compound has limited chemical stability in plasma, thereby requiring high or repeated doses in order to achieve a therapeutic effect. Thus there is a need for formulations of this drug which will exhibit increased stability.
[0004] Attempts have been made to increase the stability of bendamustine by complexing such molecule with polymeric materials. However, the approaches taken have only achieved marginal success. Thus, Pencheva et al; “HPLC study on the stability of bendamustine hydrochloride immobilized onto polyphosphoesters; J. Pharma. Biomed. Anal; (2008) attempted to improve the stability of bendamustine by complexing such compound with polyphosphoesters. However, FIG. 2 of such article shows that even the most stable complex decreases by a full log point (90%) in about 45 minutes at pH 7.
[0005] Somewhat similarly Evjen; “Development of Improved Bendamustin-Liposomes”; Masters Thesis; University of Tromso (2007) employed dual asymmetric centrifugation to incorporate bendamustine into liposomes. According to Table 18 (on page 79), these formulations only provide a marginal increase of stability relative to free bendamustine (20 minutes half-life vs. 14 minutes half-life for free bendamustine when dispersed in a cell culture medium).
[0006] Accordingly, there is a need for improved formulations of bendamustine which will provide enhanced stability in aqueous solutions, particularly plasma.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a composition comprising: (a) bendamustine, (b) a charged cyclopolysaccharide, and (c) a stabilizing agent; preferably a stabilizing agent having a charge opposite to that of the cyclopolysaccharide. Such composition provides unexpectedly desirable stability in reactive environments such as plasma, coupled with unexpectedly desirable anticancer activity. Such composition is suitable for injection or infusion into patients in need of treatment with bendamustine.
DETAILED DESCRIPTION
[0008] The present invention is directed to a composition comprising: (a) bendamustine, (b) a charged cyclopolysaccharide, and (c) a stabilizing agent having a charge opposite to that of the cyclopolysaccharide.
[0009] Preferably, the proportion of active ingredient to cyclopolysaccharide, by weight, is between about 1:12,500 and about 1:25; is more preferably between about 1:5,000 and about 1:50; is even more preferably between about 1:2,500 and about 1:75 and most preferably between about 1:1,500 and 1:100.
[0010] The stabilizing agent is typically present in a weight ratio to the cyclopolysaccharide of between about 5:1 and about 1:1000; preferably of between about 2:1 and about 1:200.
Cyclopolysaccharides
[0011] The cyclopolysaccharides which may employed in the practice of this invention include cyclodextrins, cyclomannins, cycloaltrins, cyclofructins and the like. In general, cyclopolysaccharides comprising between 6 and 8 sugar units are preferred.
[0012] Among the preferred cyclopolysaccharides which may be employed are cyclodextrins.
[0000] Cyclodextrins are cyclic oligo-1-4-alpha-D-glucopyranoses comprising at least 6 sugar units. The most widely known are cyclodextrins containing six, seven or eight sugar units. Cyclodextrins containing six sugar units are known as alpha-cyclodextrins, those containing seven sugar units are known as beta-cyclodextrins and those consisting of eight sugar units are known as gamma-cyclodextrins. Particularly preferred cyclopolysaccharides are beta-cyclodextrins.
[0013] The cyclopolysaccharides employed are modified with one or more chargeable groups. Such chargeable groups may be anionic, in which case the stabilizing agent is cationic; or such charged groups may be cationic, in which case the stabilizing agent is anionic. Preferred anionic groups include carboxyl, sulfonyl and sulphate groups; while preferred cationic groups include quarternary ammonium groups.
[0014] As employed herein the term “charged cyclopolysaccharide” refers to a cyclopolysaccharide having one or more of its hydroxyl groups substituted or replaced with a chargeable moiety. Such moiety may itself be a chargeable group (e.g., such as a sulfonyl group) or it may comprise an organic moiety (e.g., a C 1 -C 6 alkyl or C 1 -C 6 alkyl ether moiety) substituted with one or more chargeable moieties. Preferred substituted cyclopolysaccharides include, but are not limited to, sulfobutyl ether beta-cyclodextrin, beta-cyclodextrin substituted with 2-hydroxy-N,N,N-trimethylpropanammonium, carboxymethylated-beta-cyclodextrin, O-phosphated-beta-cyclodextrin, succinyl-(2-hydroxy)propyl-beta-cyclodextrin, sulfopropylated-beta-cyclodextrin, heptakis(6-amino-6-deoxy)beta-cyclodextrin, O-sulfated-beta-cyclodextrin, and 6-monodeoxy-6-mono(3-hydroxy)propylamino-b-cyclodextrin; with sulfobutyl ether beta-cyclodextrin being particularly preferred.
Cationic Stabilizing Agents
[0015] In those embodiments wherein the cyclopolysaccharide is modified with anionic groups, the stabilizing agent is selected from cationic agents, or from polycationic compounds. Cationic agents which may be employed include primary amines, secondary amines, tertiary amines or quaternary ammonium compounds, such as N-alkyl-N,N-dimethylamines, N-alkyl-N,N-diethylamines, N-alkyl-N—N-diethanoloamines, N-alkylmorpholine, N-alkylpiperidine, N-alkylpyrrolidine, N-alkyl-N,N,N-trimethylammonium, N,N-dialkyl-N,N-dimethylammonium, N-alkyl-N-benzyl-NN-diimethylammonium, N-alkyl-pyridinium, N-alkyl-picolinium, alkylamidomethylpyridinium, carbalkoxypyridinium, N-alkylquinolinium, N-alkylisoquinolinium, N,N-alkylmethylpyrollidinium, and 1-alkyl-2,3-dimethylimidazolium. Particularly preferred cationic adjuvants include sterically hindered tertiary amines, such as N-alkyl-N—N-diisopropylamine, N-alkylmorpholine, N-alkylpiperidine, and N-alkylpyrrolidine; and quaternary ammonium compounds such as cetylpyridinium chloride, benzyldimethyldodecylammonium chloride, dodecylpyridinium chloride, hexadecyltrimethylammonium chloride, benzyldimethyltetradecylammonium chloride, octadecyldimethylbenzylammonium chloride, and domiphen bromide.
[0016] Polycationic compounds such as oligo- or polyamines, or pegylated oligo- or polyamines may also be employed as the stabilizing agent. Preferred polycationic compounds include oligoamines such as spermine, spermidin, putrescine, and cadaverine; polyamines: such as polyethyleneimine, polyspermine, polyputrescine, and polycadaverine; and pegylated oligoamines and polyamines of the group listed above. Particularly preferred is PI2080, polyethyleneimine 2000 conjugated with PEG 8000.
[0017] One preferred class of cationic stabilizing agents are polypeptides comprising from about 5 to about 50, more preferably between about 6 and about 20, amino acids; wherein at least about 50% of such amino acids contain a positive charge. Most preferably, such charged amino acid is arginine. Particularly preferred members of this class of peptides include arginine rich peptides comprising at least one block sequence of 4 arginines. Another particularly preferred member of this class of peptides is protamine which has been digested with thermolysin (hereinafter referred to as Low Molecular Weight Protamine or “LMWP”).
[0018] Hydrophobically modified oligo- or polyamines may also be employed. Preferred stabilizing agent of this type include acetyl spermine, acetyl polyspermine, acetyl polyethyleneimine, butyryl spermine, butyryl polyspermine, butyryl polyethyleneimine, lauroyl spermine, lauroyl polyspermine, lauroyl polyethyleneimine, stearoyl spermine, stearoyl polyspermine, and stearoyl polyethyleneimine,
[0019] In addition, cationic polysaccharides and synthetic polycationic polymers may also be employed. Illustrative of such cationic polysaccharides are chitosan, deacetylated chitosan, quaternized cellulose, quaternized amylo se, quaternized amylopectine, quaternized partially hydrolyzed cellulose, quaternized partially hydrolyzed amylose and quaternized partially hydrolyzed amylopectine. Illustrative of such synthetic polycationic polymers are Polyquaternium 2 (poly[bis(2-chloroethyl]ether-alt-1,3-bis[3-dimethylamino)propyl]-urea quaternized); Polyquaternium 11 (poly(1-vinylpyrrolidone-co-dimethylammonioethyl methacrylate) quaternized); Polyquaternium 16 and 44 (copolymer of vinylpyrrolidone and quaternized vinylimidazole); and Polyquaternium 46 (copolymer of vinylcaprolactam, vinylpyrrolidone and quaternized vinylimidazole).
Anionic Stabilizing Agents
[0020] In those embodiments wherein the cyclopolysaccharide is modified with cationic groups, the stabilizing agent is selected from anionic agents, or from polyanionic polymers.
[0000] Preferably, such anionic agent is selected from compounds comprising a carboxy-, sulfate-, sulfono-, phosphate-, or phosphono-group.
[0021] One class of anionic agents that may be employed are anionic surfactants such as sodium 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, sodium N-lauroylsarcosinate, sodium dodecyl sulfate, sodium dodecylbenzylsulfonate and the like.
[0022] Cationic polysaccharides may also be employed as the stabilizing agent. Illustrative of such compounds are chondroitin sulfate, dermatan sulphate, kappa-carrageenan, iota-carrageenan, lambda-carrageenan, mu-carrageenan, xi-carrageenan, psi-carrageenan, tau-carrageenan, furcellaran, heparan sulphate, keratin, fucoidan, hyaluronic acid, alginic acid, poly(sulfonylbutylo)cellulose, poly(sulfonylpropylo)cellulose, poly(sulfonylpropylo)dextran, poly(sulfonylbutylo)dextran, poly(sulfonylbutylo)amylase and poly(sulfonylpropylo)amylase.
[0023] The stabilizing agent may also be a polyanionic polymer selected from polyacrylates, polymethacrylates, and their copolymers.
Excipients
[0024] The compositions of this invention may further contain pharmaceutically acceptable excipients, such as sugars, polyalcohols, soluble polymers, salts and lipids.
[0025] Sugars and polyalcohols which may be employed include, without limitation, lactose, sucrose, mannitol, and sorbitol.
[0026] Illustrative of the soluble polymers which may be employed are polyoxyethylene, poloxamers, polyvinylpyrrolidone, and dextran.
[0027] Useful salts include, without limitation, sodium chloride, magnesium chloride, and calcium chloride.
[0028] Lipids which may be employed include, without limitation, fatty acids, glycerol fatty acid esters, glycolipids, and phospholipids.
Preparation
[0029] The composition of the invention may be prepared by the dissolution of solid bendamustine in an aqueous solution of the cyclopolysaccharide; or by mixing an aqueous solution of the cyclopolysaccharide with an aqueous stock solution of bendamustine. Such resulting mixture is vigorously mixed and optionally subjected to the action of ultrasound waves to obtain an homogenous and equilibrated aqueous solution. When the cyclopolysaccharide is a cyclodextrin, it is preferred that the aqueous solution of cyclodextrin used for the preparation of composition contains at least 4% of cyclodextrin; more preferably such solution contains at least 10% of cyclodextrin.
[0030] The stabilizing agent and excipient (if present) are preferably introduced to the composition by their addition to a pre-prepared aqueous homogenous and equilibrated solution of bendamustine with the cyclopolysaccharide. Such agents may be added either as pure substances or as aqueous solutions and are preferably mixed employing gentle agitation.
[0031] Preferably, the final composition is filtered before use for injection.
[0032] The composition may be optionally freeze-dried to produce a solid material suitable for dissolution in injection media before its use. It is preferred that compositions comprising amines as stabilizing agents are freeze dried prior to the addition of such stabilizing agent, with such agent being introduced into the composition after reconstitution, shortly before use.
[0033] In one embodiment the composition of this invention is prepared by mixing the components and incubation.
[0034] In another embodiment the composition of this invention is prepared by mixing the components and applying ultrasound to the mixture.
[0035] In another embodiment the composition of this invention is prepared by mixing the components, incubation, and freeze-drying the product.
[0036] In a preferred embodiment the composition of this invention is prepared by mixing the components, applying ultrasound to the mixture, and freeze-drying the product.
[0037] The compositions of this invention demonstrate enhanced stability in aqueous solution and when introduced into plasma, both under in vitro and under in vivo conditions. Thus, such formulations will exhibit a half-life in plasma which is greater than that of non-formulated bendamustine; which half-life may be extended by more than 50% and preferably more than 100%.
[0038] In addition, the compositions of this invention exhibit unexpectedly improved activity against tumors relative to compositions comprising bendamustine and a cyclopolysaccharide; as well as relative to bendamustine alone.
EXAMPLES
Example 1
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Chondroitin
[0039] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 20% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was incubated at 20° C. for 15 minutes on ultrasonic bath and mixed with 1 mL of 25% solution of chondroitin sulfate.
Example 2
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Poly(Sulfonylbutylo)Cellulose
[0040] 6 mg of bendamustine hydrochloride are dissolved in 1 ml of 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution is preincubated at 10° C. for 15 minutes on ultrasonic bath. After that the solution is mixed with 1 ml of 2% solution of poly(sulfonylbutylo)cellulose sodium salt. The sample is incubated on ultrasonic bath for 30 minutes at 10° C.
Example 3
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Hyaluronic Acid
[0041] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was preincubated at 10° C. for 15 minutes on ultrasonic bath. After that the solution was mixed with 1 mL of 0.1% solution of hyaluronic acid sodium salt. The sample was incubated on ultrasonic bath for 30 minutes at 10° C.
Example 4
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Dextran
[0042] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 20% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was incubated at 20° C. for 15 minutes on ultrasonic bath and then mixed with 1 mL of 50% solution of dextran 40 (MW 40000) and sonicated for another 15 minutes.
Example 5
Preparation of a Bendamustine Composition with 2-Hydroxypropyl-β-Cyclodextrin and Dextran
[0043] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 20% w/w solution of 2-hydroxypropyl-β-cyclodextrin. The solution was incubated at 20° C. for 15 minutes on ultrasonic bath and then mixed with 1 mL of 50% solution of dextran 40 (MW 40000) and was sonicated for another 15 minutes.
Example 6
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Quaternized Cellulose
[0044] 2 mg of quaternized cellulose (hydrochloride salt) were dissolved in 1 mL of water. After 4 hours of preincubation on an ultrasonic bath (at room temperature), the solution was mixed with a solution of 6 mg of bendamustine hydrochloride in 1 mL of 20% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was well mixed and incubated for 15 minutes on ultrasonic bath.
Example 7
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Polyvinylpyrrolidone
[0045] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was incubated at 20° C. for 15 minutes on an ultrasonic bath and then mixed with 1 mL of 20% solution of PVP (MW=10000) and sonicated for 20 minutes.
Example 8
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Cetylpyridinium Chloride
[0046] 6 mg of bendamustine hydrochloride and 8.5 mg of mannitol were dissolved in 0.8 g of 50% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was incubated at 20° C. for 15 minutes on ultrasonic bath and then mixed with 0.2 mL of 2.5% solution of cetylpyridinium chloride.
Example 9
Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and PI2080
Preparation of PI2080
[0047] Polyethyleneimine (PEI, MW 2000) was purchased from Aldrich. Poly(ethylene glycol) monomethyl ether (PEG, MW 8500) was purchased from Polymer Sources Inc. PI2080, a conjugate of PEG and PEI, was prepared following the procedure described by Vinogradov S. V. et al. in Bioconjugate Chem. 1998, 9, 805-812.4 g of PEG was reacted with 1,1′-carbonyldiimidazole in 20 mL anhydrous acetonitrile. The product of the reaction was dialysed twice against water using SpectraPor 3 membrane, MWCO 3500, and freeze-dried. The freeze-dried material was dissolved in 32 mL of methanol, mixed with 2.9 g of PEI and incubated for 24 hours at 25° C. The product was dialysed twice against water using SpectraPor 3 membrane, MWCO 3500, and the product PI2080 was freeze-dried.
[0000] Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and PI2080.
[0048] 2.5 mg of bendamustine hydrochloride and 4.3 mg of mannitol were dissolved in 0.8 g of 50% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was incubated at 20° C. for 15 minutes on ultrasonic bath and then mixed with 0.2 mL of 5% solution of PI2080.
Example 10
Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and with Protamine Sulphate
[0049] 2.5 mg of bendamustine hydrochloride and 4.3 mg of mannitol were dissolved in 0.800 g of 50% w/w solution of Sodium sulfobutyl ether β-cyclodextrin. Solution was shaken at 20° C. for 90 minutes and then incubated for 30 minutes in an ultrasonic bath. Then the mixture was transferred into a suspension of 30 mg of protamine sulfate in 0.163 g of water and vigorously mixed for 15 minutes.
Example 11
Pharmacokinetics of Bendamustine Dosed to Rats in Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Cetylpyridinium Chloride
[0050] The Tested Compositions:
[0000] Control: 6 mg/mL bendamustine hydrochloride, 10.2 mg/mL of mannitol in 0.9% NaCl; dose of 20 mg/kg
Inventive Composition: 5 mg/g bendamustine hydrochloride, 40% w/w sodium sulfobutyl ether β-cyclodextrin, 0.5% cetylpyridinium chloride, 8.5 mg/g mannitol in water (produced following the procedure of Example 8); dose of 20 mg/kg.
Animals:
[0051] Female Sprague-Dawley rats (250-350 g). The animals were kept three per cage with an air filter cover under light (12 h light/dark cycle, light on at 06 h00) and controlled temperature 22° C.+/−1° C. All manipulations with the animals were performed under a sterilized laminar hood. The animals had ad libitum access to Purina mouse chow and water. The animals were fasted overnight and anesthetized, before dosing.
Dosing and Sampling:
[0052] The inventive bendamustine composition and control were administered intravenously to rats in tail vein. After time intervals of 5, 15, 30, 45 min, 1, 1.5, 2 and 3 hrs post-injection, blood samples were collected. The rats were anesthetized by general inhalation of isoflurane. The blood samples were collected from the jugular vein with heparinized tube and kept on ice. Blood was immediately centrifuged, and plasma was separated. The plasma samples were immediately extracted.
Sample Extraction and Analysis:
[0053] The plasma samples 0.100 mL were transferred to plastic tubes. The samples were extracted with 0.400 mL of 100 mM HCl in acetonitrile while being shaken vigorously for 30 seconds. The samples were centrifuged at 10000 RPM for 5 minutes. The supernatant was separated. The samples were frozen in dry ice and kept at −80° C. until HPLC analysis. 20 microliter aliquots were injected into the HPLC for analysis.
The HPLC Conditions:
[0054] C18 reversed phase column 50×4.6 mm, Symmetry/Shield 3.5 micrometer
Column temperature 30° C.
Flow rate 1.5 mL/min
Injection volume 20 microliters
Fluorescence detection at wavelengths: excitation 327 nm, emission 420 nm
Mobile phase: Buffer A: 5% acetonitrile 0.1% TFA
Buffer B: 90% acetonitrile 0.1% TFA
Run time: 10 min
[0055] The improved pharmacokinetic profiles of bendamustine for tested composition versus the control is shown in Table 1 below.
[0000]
TABLE 1
Concentration of bendamustine in rat plasma vs. time post injection
Control
Inv. Composition
Time
[ng/mL]
[ng/mL]
[hours]
Mean (SEM)
Mean (SEM)
0.08
12304 (2498)
16721 (1981)
0.25
7625 (536)
10713 (1458)
0.5
3046 (260)
4855 (874)
0.75
966 (192)
2165 (101)
1
414 (143)
1108 (104)
1.5
133 (80)
418 (57)
2
54 (34)
197 (25)
3
9 (6)
57 (24)
SEM—standard error of mean
[0056] The above data show that the stability of bendamustine in plasma is greatly increased in the inventive compositions of this invention.
Example 12
Pharmacokinetics of Bendamustine Dosed to Rats in Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and PI12080
The Tested Compositions:
[0057] Control: 2.5 mg/mL bendamustine hydrochloride, 4.25 mg/mL of mannitol in 0.9% NaCl; dose of 10 mg/kg
Inventive Composition: 2.5 mg/mL bendamustine hydrochloride, 40% w/w sodium sulfobutyl ether β-cyclodextrin, 1% PI2080, 4.3 mg/g mannitol in water (prepared according to the procedure set forth in Example 9); dose of 10 mg/kg.
Animals:
[0058] Female Sprague-Dawley rats (250-350 g). The animals were kept three per cage with an air filter cover under light (12 h light/dark cycle, light on at 06 h00) and controlled temperature 22° C.+/−1° C. All manipulations with the animals were performed under a sterilized laminar hood. The animals had ad libitum access to Purina mouse chow and water. The animals were fasted overnight and anesthetized, before dosing.
Dosing and Sampling:
[0059] Inventive bendamustine composition and control were administered intravenously to rats in tail vein. Blood samples were collected after time intervals of 5, 15, 30, 45 min, 1, 1.5, 2 and 3 hrs post-injection. The rats were anesthetised by general inhalation of isoflurane. The blood samples were collected from the jugular vein with heparinized tube and kept on ice. The blood was immediately centrifuged, and plasma was separated. The plasma samples were immediately extracted.
Sample Extraction and Analysis:
[0060] The plasma samples 0.100 mL were transferred to plastic tubes. The samples were extracted with 0.400 mL of 100 mM HCl in acetonitrile while being shaken vigorously for 30 seconds. The samples were centrifuged at 10000 RPM for 5 minutes. The supernatant was separated. The samples were frozen in dry ice and kept at −80° C. until HPLC analysis. The aliquots of 20 microliters were injected into HPLC for analysis.
The HPLC Conditions:
[0061] C18 reversed phase column 50×4.6 mm, Symmetry/Shield 3.5 micrometer
Column temperature 30° C.
Flow rate 1.5 mL/min
Injection volume 20 microliters
Fluorescence detection at wavelengths: excitation 327 nm, emission 420 nm
Mobile phase: Buffer A: 5% acetonitrile 0.1% TFA
Buffer B: 90% acetonitrile 0.1% TFA
Run time: 10 min
[0062] The improved pharmacokinetic profiles of Bendamustine for tested inventive composition versus the control is shown in Table 2 below.
[0000]
TABLE 2
Concentration of bendamustine in rat plasma vs. time post injection
Control
Inv. Composition
Time
[ng/mL]
[ng/mL]
[hours]
Mean (SEM)
Mean (SEM)
0.08
6045 (388)
6124 (508)
0.25
2428 (250)
2814 (392)
0.5
520 (105)
1234 (92)
0.75
145 (35)
549 (95)
1
48 (11)
314 (118)
1.5
8 (1)
188 (97)
2
2 (1)
118 (60)
3
0 (1)
48 (23)
SEM—standard error of mean
[0063] The above data demonstrates that the stability of bendamustine in plasma is greatly increased in the compositions of the present invention.
Example 13
Pharmacokinetics of Bendamustine Dosed to Rats in Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Protamine Sulphate
The Tested Compositions:
[0064] Control: 2.5 mg/mL bendamustine hydrochloride, 4.25 mg/mL of mannitol in 0.9% NaCl; dose of 10 mg/kg
Inventive Composition: 2.5 mg/mL bendamustine hydrochloride, 40% w/w sodium sulfobutyl ether β-cyclodextrin, 3% protamine sulfate, 4.3 mg/g mannitol in water (produced according to the process described in Example 10); dose of 10 mg/kg.
Animals:
[0065] Female Sprague-Dawley rats (250-350 g). The animals were kept three per cage with an air filter cover under light (12 h light/dark cycle, light on at 06 h00) and controlled temperature of 22° C.+/−1° C. All manipulations with the animals were performed under a sterilized laminar hood. The animals had ad libitum access to Purina mouse chow and water. The animals were fasted overnight and anesthetized, before dosing.
Dosing and Sampling:
[0066] Bendamustine composition and control were administered intravenously to rats in tail vein. After time intervals 5, 15, 30, 45 min, 1, 1.5, 2 and 3 hrs post-injection, the blood samples were collected. The rats were anesthetized by general inhalation of isoflurane. The blood samples were collected from the jugular vein with heparinized tube and kept on ice. Blood was immediately centrifuged, and plasma was separated. The plasma samples were immediately extracted.
Sample Extraction and Analysis:
[0067] The plasma samples 0.100 mL were transferred to plastic tubes. The samples were extracted with 0.400 mL of 100 mM HCl in acetonitrile while being shaken vigorously for 30 seconds. The samples were centrifuged at 10000 RPM for 5 minutes. The supernatant was separated. The samples were frozen in dry ice and kept at −80° C. until HPLC analysis. 20 microliter aliquots were injected into HPLC for analysis.
The HPLC Conditions:
[0068] C18 reversed phase column 50×4.6 mm, Symmetry/Shield 3.5 micrometer
[0000] Column temperature 30° C.
Flow rate 1.5 mL/min
Injection volume 20 microliters
Fluorescence detection at wavelengths: excitation 327 nm, emission 420 nm
Mobile phase: Buffer A: 5% acetonitrile 0.1% TFA
Buffer B: 90% acetonitrile 0.1% TFA
Run time: 10 min
[0069] The improved pharmacokinetic profiles of Bendamustine for tested composition versus the control is shown in Table 3 below.
[0000]
TABLE 3
Concentration of bendamustine in rat plasma vs. time post
injection
Control
Inv. Composition
Time
[ng/mL]
[ng/mL]
[hours]
Mean (SEM)
Mean (SEM)
0.08
6045 (388)
3853 (787)
0.25
2428 (250)
2416 (716)
0.5
520 (105)
1100 (313)
0.75
145 (35)
595 (154)
1
48 (11)
415 (140)
1.5
8 (1)
139 (20)
2
2 (1)
126 (36)
3
0 (0)
47 (18)
4
19 (9)
SEM—standard error of mean
[0070] The above data shows that the stability of the cyclopolysaccharide composition is greatly increased when compared to that of bendamustine alone.
Example 14
Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Luviquat FC370
[0071] 6 mg of bendamustine hydrochloride was dissolved in 1 mL of 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was preincubated at 10° C. for 15 minutes on ultrasonic bath; and then mixed with 1 mL of 0.1% solution of Luviquat FC370.
[0000] Luviquat FC370 (Polyquaternium-16) is a copolymer of vinylpyrrolidone and quaternized vinylimidazole (CAS No. 95144-24-4 (BASF). The sample was incubated on ultrasonic bath for 30 minutes at 10° C.
Example 15
Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Luviquat Hold
[0072] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was preincubated at 10° C. for 20 minutes in an ultrasonic bath; and then mixed with 1 mL of 0.15% solution of Luviquat HOLD. Luviquat HOLD (Polyquaternium-46) is 1H-imidazolium, 1-ethenyl-3-methyl-methyl sulphate polymer with 1-ethenylhexahydro-2Hazepin-2-one and 1-ethenyl-2-pyrrolidinone, CAS No. 174761-16-1, (BASF). The sample was incubated in an ultrasonic bath for 30 minutes at 10° C.
Example 16
Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Quaternized Poly(Vinylpyrrolidone-co-2-Dimethylaminoethyl Methacrylate)
[0073] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was preincubated at 10° C. for 15 minutes in an ultrasonic bath. After that the solution was mixed with 1 mL of 0.1% solution of quaternized poly(vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate). The sample was incubated in an ultrasonic bath for 30 minutes at 10° C.
Example 17
Preparation of a Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Quaternized Poly(Vinylpyrrolidone-co-2-Dimethylaminoethyl Methacrylate)
[0074] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was preincubated at 10° C. for 15 minutes in an ultrasonic bath. After that the solution was mixed with 1 mL of 0.1% solution of quaternized poly(vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate). The sample was incubated in an ultrasonic bath for 30 minutes at 10° C.
Example 18
Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Chitosan
[0075] 5 mg of low-weight chitosan were suspended in 5 mL of 0.2M chydrochloric acid and mixed overnight. The content of the vial was filtered through a 0.45 um glass fiber filter and lyophilized. 2 mL of a 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin were added to the lyophilized material. The mixture was incubated at 20° C. for 24 hours and filtered through a 0.45 um glass fiber filter. 1 mL of said solution was used to dissolve 6 mg of bendamustine hydrochloride. The solution was incubated at 10° C. for 20 minutes in an ultrasonic bath.
Example 19
Preparation of Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Quaternized poly(bis(2-chloroethyl)ether-alt-1,3-bis[3-dimethylamino)propyl]-urea
[0076] 6 mg of bendamustine hydrochloride were dissolved in 1 mL of a 30% w/w solution of sodium sulfobutyl ether β-cyclodextrin. The solution was preincubated at 10° C. for 15 minutes in an ultrasonic bath. After that the solution was mixed with 1 mL of a 0.05% solution of quaternized poly(bis(2-chloroethyl)ether-alt-1,3-bis[3-dimethylamino)propyl]-urea. The sample was incubated in an ultrasonic bath for 30 minutes at 10° C.
Example 20
a. Preparation of Low Molecular Weight Protamine (LMWP)
[0077] 2 g of protamine sulfate were dissolved in 70 mL 0.1 M ammonium acetate buffer, pH 7 to form a protamine sulphate solution. 20 mg of thermolysin were dissolved in 10 mL 50 mM Tris buffer, pH 7.4 to form a thermolysin solution. The thermolysin solution was added to the protamine sulfate solution, followed by 70 microliters of 1 M aqueous calcium chloride. The mixture was incubated for 30 minutes at room temperature. 0.7 mL 0.7 M EDTA solution was added to the mixture. The mixture was lyophilized. The dry material was redissolved in 0.2% aqueous acetic acid, 100 mg per 1 mL and filtered through 0.22 micrometer filter. 5 mL of the solution was injected into RP-HPLC column Vaydac 218TPI52050, 5×25 cm. The sample was eluted with gradient ethanol in water comprising 0.2% acetic acid. The fraction containing the product was collected and lyophilized.
b. Preparation of Bendamustine Composition with Sodium sulfobutyl Ether (3-Cyclodextrin (“SBECD”) and Low Molecular Weight Protamine (“LMWP”)
[0078] 400 mg of sodium sulfobutyl ether β-cyclodextrin were mixed with 0.600 mL of water and shaken until completely dissolved. 16 mg of bendamustine hydrochloride and 27.3 mg of mannitol were added to this solution and shaken for 90 minutes. 20 mg of LMWP were dissolved in 936.8 mg of water, and mixed with the bendamustine solution. The product was stored at 4° C. The product was assessed for bendamustine content using analytical RP-HPLC chromatography as follows. 10 μL samples were separated using Waters SymmetryShield RP-18 3.5 μm column (4.6×50 mm) at the flow of 1.5 mL/min of acetonitrile-water gradient containing 0.1% TFA. Peak detection has been performed by means of UV absorption detection at 260 nm. The area of the peak of bendamustine was used to evaluate the rate of drug stability, in triplicates. The area under the peak of bendamustine after 24 hours was 101.8% of the initial (standard deviation 2%).
Example 21
Preparation of Lyophilised Bendamustine Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Low Molecular Weight Protamine
[0079] The composition of Example 20 was lyophilised. The product was amorphous white solid, soluble in water. The product before use was reconstituted with 1.536 mL of water.
Example 22
Cytotoxicity of Bendamustine Compositions
[0080] H460, RPMI8226, and MDA-MB-231 cells were maintained in appropriate medium, containing 10% foetal bovine serum (FBS) and antibiotics. 24 h after plating bendamustine (BM); BM in the presence of 0.1% sodium sulfobutyl ether β-cyclodextrin (SBECD): and BM in the presence of 0.1% SBECD and 0.002-0.005% low molecular weight protamine (LMWP) were added in different concentrations to cell cultures and cells were grown for three days. The drug cytotoxicity was evaluated using WST-1 procedure.
[0081] IC50 values were estimated for bendamustine, bendamustine formulated in SBECD, and bendamustine formulated in SBECD/LMWP. Table 4 shows the increase in BM potency produced by formulation of the drug in SBECD or SBECD/LMWP. As a measure of change in BM cytotoxic activity the ratios of BM IC50 to IC50 of BM in SBECD or SBECD/LMWP formulation were calculated. For each cell line, these ratios represent averages for 3-12 independent experiments.
[0000]
TABLE 4
Increase in BM potency (BM IC50/formulation
IC50, in parentheses standard error).
Cell line
Composition
H460
RPMI8226
MDA-MB-231
BM
1.0
1.0
1.0
BM + SBECD
1.2 (0.2)
1.6 (0.1)
1.6 (0.5)
BM + SBECD + LMWP
1.9 (0.3)
2.5 (0.4)
2.2 (0.1)
[0082] SBECD formulation increased potency of BM, decreasing its IC50. Addition of LMWP to SBECD formulation further substantially decreased BM IC50. In two cell lines, H460 and RPMI8226, effect of LMWP was statistically significant, p=0.036 and 0.018, respectively. In MDA-MB-231 cells effects of both formulations were not significantly different. For these three cell lines, average decrease in IC50 of BM was 1.5- and 2.2-fold for SBECD and SBECD/LMWP, respectively.
Example 23
Cytotoxicity of Bendamustine Compositions Pre-Incubated with Media
[0083] BM and SBECD/LMWP formulation (40 mg/ml BM in 20% SBECD, 1% LMWP) were incubated in DMEM medium containing 10% FBS for 0, 1, or 4 h and then were added in varying concentrations to RPMI8226 cells. During BM treatment, concentrations of SBECD and LMWP were kept constant in culture medium at 0.1 and 0.05%, respectively. Cells were then grown for 72 h. The drug cytotoxicity was evaluated using WST-1 procedure. The results are presented in Tables 5 and 6 below.
[0000]
TABLE 5
Cell growth of RPMI8226 cells treated with bendamustine,
pre-incubated in cell culture medium for 0, 1, or 4 h.
Bendamustine,
BM 0 h
BM 1 h
BM 4 h
uM
Cell growth, %
1
100
100
100
15
83
100
100
31
70
100
100
62
46
106
104
125
11
20
105
250
−23
−45
75
500
−87
−85
8
1000
−98
−102
−99
[0000]
TABLE 6
Cell growth of RPMI8226 cells treated with SBECD/LMWP
formulation of bendamustine, pre-incubated in cell culture
medium for 0, 1, or 4 h.
BM/SBECD/
LMWP
BM/SBECD/LMWP
BM/SBECD/LMWP
Bendamustine,
0 h
1 h
4 h
uM
Cell growth, %
1
100
100
100
15
71
71
114
31
35
37
51
62
21
39
29
125
−14
−25
8
250
−99
−98
−104
500
−99
−98
−101
1000
−96
−98
−108
[0000] TABLE 7 IC50 of bendamustine and BM/SBECD/LMWP formulation, pre- incubated in cell culture medium for 0, 1, or 4 h, in RPMI8226 cells. Time of pre- IC50 of bendamustine, uM incubation, h BM BM/SBECD/LMWP 0 62 32 1 106 38 4 390 53 IC50, TGI, and LC50 parameters were calculated for each time of pre-incubation. IC50, μM/h TGI, μM/h LC50, μM/h BM 85 +/− 10 98 +/− 18 107 +/− 11 SBECD/LMWP 5.2 +/− 0.2 6.0 +/− 0.1 3.5 +/− 0.9 formulation Where: IC50 - concentration of a drug that causes 50% growth inhibition of cells; TGI - concentration of a drug that causes total growth inhibition of cells; LC50 - concentration of a drug that causes 50% death of cells.
The results show that the composition of BM, SBECD and LMWP retains potency longer than BM alone.
Example 24
Cytotoxicity of Bendamustine Composition Comprising SBECD and LMWP
[0084] RPMI8226, H69, MDA-MB-231, and H460 cells were maintained in appropriate medium, containing 10% FBS and antibiotics. 24 h after plating, bendamustine, and bendamustine formulated in SBECD/LMWP (40 mg/ml BM in 20% SBECD, 1% LMWP) were added in different concentrations to cell cultures and cells were grown for three days. The drug cytotoxicity was evaluated using WST-1 procedure. The results are presented in the Table 8 below.
[0000]
TABLE 8
Cell Line
BM
SBECD/LMWP
RPMI8226
117
61
H69
254
119
H460
601
228
MDA-MB-231
600
321
[0085] The above data shows that the compositions of this invention possess enhanced cytotoxicity.
Example 25
Pharmacokinetics of Bendamustine Dosed to Rats in Composition with Sodium Sulfobutyl Ether β-Cyclodextrin and Low Molecular Weight Protamine (LMWP)
[0086] The following compositions were prepared for testing:
[0000] Control: 5 mg/mL bendamustine hydrochloride, 10.2 mg/mL of mannitol in 0.9% NaCl; dose of 10 mg/kg
Composition 25A
[0087] 5 mg/mL bendamustine hydrochloride, 20% w/w sodium sulfobutyl ether β-cyclodextrin, 10.2 mg/g mannitol in water; dose of 10 mg/kg.
Composition 25 B
[0088] 5 mg/mL bendamustine hydrochloride, 20% w/w sodium sulfobutyl ether β-cyclodextrin, 1% LMWP, 10.2 mg/g mannitol in water; dose of 10 mg/kg.
Animals:
[0089] Female Sprague-Dawley rats (250-350 g). The animals were kept three per cage with an air filter cover under light (12 h light/dark cycle, light on at 06 h00) and controlled temperature 22° C.+/−1° C. All manipulations with the animals were performed under a sterilized laminar hood. The animals had ad libitum access to Purina mouse chow and water. The animals were fasted overnight and anesthetized, before dosing.
Dosing and Sampling:
[0090] The bendamustine compositions and control were administered intravenously to rats via a tail vein. Blood samples were collected 5, 15, 30, 45 min, 1, 1.5, 2, 3 and 4 hrs post-injection. The rats were anesthetized by general inhalation of isoflurane. The blood samples were collected from the jugular vein with a heparinized tube and kept on ice. The sample was immediately centrifuged, and the plasma separated. The plasma samples were immediately extracted.
Sample Extraction and Analysis:
[0091] The plasma samples 0.100 mL were transferred to plastic tubes. The samples were extracted with 0.400 mL of 100 mM HCl in acetonitrile while being shaken vigorously for 30 seconds. The samples were centrifuged at 10000 RPM for 5 minutes. The supernatant was separated. The samples were frozen in dry ice and kept at −80° C. until HPLC analysis. The aliquots of 20 microliters were injected into HPLC for analysis.
The HPLC Conditions:
[0092] C18 reversed phase column 50×4.6 mm, Symmetry/Shield 3.5 micrometer
Column temperature 30° C.
Flow rate 1.5 mL/min
Injection volume 20 microliters
Fluorescence detection at wavelengths: excitation 327 nm, emission 420 nm
Mobile phase: Buffer A: 5% acetonitrile 0.1% TFA
Buffer B: 90% acetonitrile 0.1% TFA
Run time: 10 min
[0093] The pharmacokinetic profiles of Bendamustine for tested composition versus the control is shown in Table 9 below.
[0000]
TABLE 9
Concentration of bendamustine in rat plasma vs. time post injection
Control
Composition
Composition
Time
[ng/mL]
25A [ng/mL]
25B [ng/mL]
[hours]
Mean (SEM)
Mean (SEM)
Mean (SEM)
0.08
6045 (388)
5233 (143)
3629 (1286)
0.25
2428 (250)
1702 (217)
1915 (708)
0.5
520 (105)
307 (73)
852 (251)
0.75
145 (35)
72 (25)
468 (80)
1
47 (11)
36 (17)
317 (53)
1.5
8 (1)
16 (10)
160 (32)
2
2 (1)
5 (4)
93 (27)
3
0 (0)
0 (0)
47 (20)
4
12 (5)
SEM—standard error of mean
[0094] The example shows that the presence of LMWP in Bendamustine composition with SBECD considerably increased the half-life time of BM in plasma.
Example 26
Efficacy of Bendamustine Compositions on Murine Experimental Lung Metastasis Model
Animals
[0095] Female Charles Rivers C57B1/6 mice, aged 5 to 6 weeks, were purchased from Charles River Canada Inc. The animals were kept 5 per cage with an air filter cover under light (12 light/dark cycle, light on at 6H00) and temperature (22°±1° C.)-controlled environment. All manipulations of animals were performed under a sterilized laminar hood. The animals had ad libitum access to Purina mouse chow (Pro Lab PMH 4018, Trademark of Agway, Syracuse, N.Y.) and water. These animal studies were conducted according to the “Guidelines for Care and Use of Experimental Animals”.
Tumor Cell Culture:
[0096] Lewis Lung carcinoma 3LL cells were cultured in the appropriated culture medium. The cells were harvested in their logarithmic growth phase for the preparation of tumor implantation.
Tumor Implantation:
[0097] Lewis Lung carcinoma 3LL cells (2.0 to 5.0×105 cells in 200 ul PBS) were implanted intravenously by tail vein to establish experimental lung metastasis tumor models.
Treatments:
[0098] The treatments were performed on day after tumor implantation. The animals were dosed with the following dosing solutions.
Control: (0.9%, NaCl)
Compositions:
[0099] non-formulated bendamustine (BM), (50 mg/kg)
[0100] Bendamustine (50 mg/kg) in 20% SBECD, 1% LMWP
Efficacy Evaluation:
[0101] Metastasis formation was evaluated by counting the numbers of metastasis spots on the lung surface. Routine metastasis examination were done for all organs at the end of the study.
[0102] The results of efficacy evaluation are presented in Table 10 below.
[0000]
TABLE 10
Inhibition on
Inhibition on
metastasis
Lung metastasis
metastasis
formation vs not
number (animal
formation vs
formulated BM
Treatment
number)
control, (%)
(%)
Control
65.5 ± 7.8 (8)
0
—
BM (50 mg/kg)
56.1 ± 9.5 (9)
14.4
0
BM (50 mg/kg),
37.0 ± 8.1 (9)
43.5**
34.0*
20% SBECD,
1% LMWP
**Statistically significant, p < 0.01
*Statistically significant, p < 0.05
[0103] The results show statistically significant improvement of efficacy of the composition comprising SBECD and LMWP vs. non-formulated drug.
Example 27
Efficacy of Bendamustine Compositions on Human Breast Carcinoma (MDA-MB 231) Subcutaneous (s.c.) Solid Tumours in Nude Mice
Animal:
[0104] balb/c mice aged 5 to 6 weeks were purchased from Charles River Canada Inc. The animals were kept 5 per cage with an air filter cover under light (12 light/dark cycle, light on at 6H00) and temperature (22° C.±1° C.)-controlled environment. All manipulations of animals were performed under a sterilized laminar hood. The animals had ad libitum access to Purina mouse chow (Pro Lab PMH 4018, Trademark of Agway, Syracuse, N.Y.) and water. These animal studies were conducted according to the “Guidelines for Care and Use of Experimental Animals”.
Tumor Cell Culture:
[0105] Human breast cancer cells MDA-MB 231 were cultured in the appropriated culture medium. The cells were harvested in their logarithmic growth phase for the preparation of tumor implantation.
Tumor Implantation:
[0106] Human tumor or myeloma cells (2.5 to 5.0×10 6 cells) were implanted subcutaneously in 0.200 mL of medium containing 30% Matrigel on the two flanks of balb/c nu/nu mice through a 1 to 2 cm long 20-gauge needle.
Treatments:
[0107] 2 to 3 weeks after tumor cell implantation, animals that developed s.c. solid tumors were selected and divided into several homogeneous groups (n=5 animals per group or dose) with respect to tumor size (0.5 to 0.8 cm in diameter). The treatments were performed next day. The animals were dosed with the following dosing solutions.
Control: (0.9%, NaCl)
Compositions:
[0108] non-formulated Bendamustine, (35 mg/kg)
[0109] Bendamustine (35 mg/kg) in 40% SBECD, 1% protamine sulfate (formulated BM)
Efficacy Evaluation:
[0110] Subcutaneous solid tumor measurements were performed on the day of first injection and at 3- to 4-day intervals thereafter. The two largest perpendicular diameters of each tumor were measured with calipers and tumor sizes were estimated using the formula:
[0000] TV=L×W/2 where TV: tumor volume; L: length; W: width.
The body weights of animals were also noted.
[0111] The results are presented in Table 11 below.
[0000] TABLE 11 Body Tumor Inhibition weight volume on % vs Groups on day day 14 (g) control (number of 14 (number of (on day animals) (g) tumors) 14) Remarks Control (0.9%, 19.9 ± 0.35 1.80 ± 0.19 — 1 of 5 dead on day 11 due to NaCl) (5) (4) (8) tumor metastasis. All animals were sacrificed on day 14 due to protocol limit points with tumor size. BM (35 mg/kg) 18.1 ± 0.39 0.54 ± 0.06 70.2% (5) (5) (10) BM (35 mg/kg), 18.6 ± 0.30 0.32 ± 0.09 82.0% 3 of 5 mice were dead on day 40% SBECD, (2) (4) 4 after treatments. 1% PS (5)
Table 12 shows the effect of BM and its compositions on the growth of tumors.
[0000]
TABLE 12
Tumor weight after treatment in human breast carcinoma
MDA-MB 231 s.c. solid tumors in nude mice
Non-treated
BM (35 mg/kg),
Control
BM (35 mg/kg)
40% SBECD,
Time
[g]
[g]
1% PS [g]
[days]
Average (SEM)
Average (SEM)
Average (SEM)
0
0.277 (0.031)
0.237 (0.008)
0.247 (0.012)
2
0.329 (0.034)
0.250 (0.028)
0.242 (0.039)
4
0.436 (0.052)
0.294 (0.027)
0.151 (0.045)
7
0.615 (0.065)
0.313 (0.030)
0.182 (0.046)
9
0.838 (0.095)
0.349 (0.038)
0.216 (0.046)
11
1.164 (0.149)
0.417 (0.046)
0.232 (0.065)
14
1.803 (0.185)
0.537 (0.055)
0.324 (0.092)
SEM—standard error of mean
[0112] The results show unexpected toxicity and good efficacy of the composition comprising SBECD and protamine sulfate.
Example 28
Efficacy of Bendamustine Compositions on Human Breast Carcinoma MDA-MB 231 s.c. Solid Tumors in Nude Mice
[0113] The experiment was performed as described in example 27, using the following compositions for treatment:
Control: (0.9%, NaCl)
Compositions:
[0114] non-formulated bendamustine, (30 mg/kg)
[0115] Bendamustine (30 mg/kg) in 40% SBECD (formulated BM)
[0116] The treatment was performed on days 1, 2, 9, and 10.
[0117] The results are presented in Table 13.
[0000]
TABLE 13
Real Tumor
Tumor weight on day
weight on day 19
19 estimated from
in autopsy
Groups
measurements of the
(g)
(number of
Treatment
tumor size (g)
(number of
animals)
Schedules
(number of tumors)
tumors)
G1. Control
Day 1, 2,
1.70 ± 0.15 (10)
0.855 ± 0.105
(0.9%, NaCl) (5)
9, 10
(10)
G2.
Day 1, 2,
0.684 ± 0.10 (10)
0.275 ± 0.052
BM (30 mg/kg)
9, 10
(10)
(5)
G3.
Day 1, 2,
1.05 ± 0.18 (10)
0.413 ± 0.067
BM (30 mg/kg),
9, 10
(10)
40% SBECD (5)
[0118] Table 14 shows the effect of BM and its compositions on the growth of tumors.
[0000]
TABLE 14
Tumor weight after treatment in human breast carcinoma
MDA-MB 231 s.c. solid tumors in nude mice
Non-treated
BM (30 mg/kg),
Control
BM (30 mg/kg)
40% SBECD,
Time
[g]
[g]
[g]
[days]
Average (SEM)
Average (SEM)
Average (SEM)
0
0.252 (0.020)
0.203 (0.028)
0.200 (0.024)
2
0.288 (0.019)
0.238 (0.023)
0.245 (0.022)
5
0.384 (0.029)
0.267 (0.022)
0.300 (0.027)
7
0.536 (0.028)
0.313 (0.028)
0.392 (0.038)
9
0.693 (0.044)
0.388 (0.045)
0.522 (0.060)
12
1.034 (0.049)
0.497 (0.060)
0.641 (0.071)
14
1.174 (0.065)
0.550 (0.075)
0.756 (0.090)
16
1.456 (0.104)
0.594 (0.084)
0.853 (0.125)
19
1.704 (0.145)
0.684 (0.098)
1.051 (0.176)
SEM—standard error of mean
[0119] The above data shows that a two component system comprising bendamustine and a charged cyclodextrin (without an oppositely charged stabilizing agent) is less than that of bendamustine alone.
Example 29
Efficacy of Bendamustine Compositions on Human Breast Carcinoma MDA-MB 231 s.c. Solid Tumors in Nude Mice
[0120] The experiment was performed employing the procedures described in Example 28, using the following compositions for treatment:
Control: (0.9%, NaCl)
Compositions:
[0121] non-formulated Bendamustine, (30 mg/kg)
[0122] Bendamustine (30 mg/kg) in 20% SBECD, 1% LMWP (formulated BM)
[0123] The treatment was performed on days 1, 2, 9, and 10.
[0124] The results are presented in Table 15.
[0000] TABLE 15 Tumor weight on Inhibition % vs Groups (animal Treatment day 16 (g) control (on day number) Schedules (number of tumors) 16) G1. Control (0.9%, Day 1, 2, 0.789 ± 0.056 (6) — NaCl) (6) 9, 10 G2. Day 1, 2, 0.487 ± 0.067 (6) 38.3 BM (30 mg/kg) (6) 9, 10 G3. Day 1, 2, 0.364 ± 0.028 (6) 53.9 BM (30 mg/kg), 9, 10 20% SBECD, 1% LMWP (6) Note. The tumors implanted in the left flank were much smaller than those in the right flank due to the lower number of tumor cells inoculated. The volume of these tumors is not included in the data presented.
The results show that Bendamustine composition with 20% SBECD and 1% LMWP is more active than non-formulated drug—a result which is unexpected in view of the results obtained in Example 28 above.
[0000]
TABLE 16
Tumor weight after treatment in human breast
carcinoma MDA-MB 231
s.c. solid tumors in nude mice
Non-treated
BM (30 mg/kg),
Control
BM (30 mg/kg)
20% SBECD,
Time
[g]
[g]
1% LMWP [g]
[days]
Average (SEM)
Average (SEM)
Average (SEM)
0
0.161 (0.007)
0.139 (0.013)
0.140 (0.018)
2
0.187 (0.011)
0.178 (0.027)
0.163 (0.016)
4
0.233 (0.024)
0.202 (0.039)
0.167 (0.016)
6
0.288 (0.036)
0.259 (0.049)
0.188 (0.010)
8
0.344 (0.027)
0.295 (0.054)
0.216 (0.014)
10
0.422 (0.031)
0.319 (0.044)
0.234 (0.013)
12
0.508 (0.041)
0.361 (0.050)
0.258 (0.012)
14
0.589 (0.057)
0.417 (0.054)
0.319 (0.022)
16
0.789 (0.056)
0.487 (0.067)
0.364 (0.028)
SEM—standard error of mean
Example 30
Bendamustin Chemical Stability in Compositions with Sulfobutyl Beta Cyclodextrin (SBECD) and Low Molecular Weight Protamine (LMWP) in Phosphate Buffer
[0125] 4% SBECD (w/w) in phosphate buffer (SBECD/PB) was prepared by dissolving SBECD in 5 mM phosphate buffer and adjusting pH to 7.2.
[0126] The following compositions were prepared and tested:
[0000] Control: 0.6 mg/mL Bendamustine Hydrochloride (BM) in water, prepared by dissolving BM in 5 mM phosphate buffer (PB) pH 7.2
Composition 30-1: 0.6 mg/mL BM in 4% SBECD prepared by dissolving BM in SBECD/PB
Composition 30-2: 0.6 mg/mL BM in 4% SBECD and 0.2% LMWP, prepared by dissolving BM in SBECD/PB, and adding LMWP
Composition 30-3: 0.6 mg/mL BM in 4% SBECD and 1% LMWP, prepared by dissolving BM in SBECD/PB, and adding LMWP
Composition 30-4: 0.6 mg/mL BM in 4% SBECD and 0.2% LMWP, prepared by dissolving LMWP in SBECD/PB, and adding BM
Composition 30-5: 0.6 mg/mL BM in 4% SBECD and 0.2% LMWP, prepared by dissolving LMWP in SBECD/PB, and adding BM.
[0127] The compositions were incubated at 25° C., and were periodically analyzed by HPLC as follows. 10 μL samples were separated on HPLC using Waters SymmetryShield RP-18 3.5 μm column (4.6×50 mm) at the flow of 1.5 mL/min of acetonitrile-water gradient containing 0.1% TFA. Peak detection was performed by means of UV absorption detection at 260 nm. The area of the peak of bendamustine was used to evaluate the rate of drug decomposition in the first order kinetics model. The results expressed as decomposition half times (T1/2) are presented in Table 17 below.
[0000]
TABLE 17
Composition
T½
Control: 0.6 mg/mL BM
44 min
Composition 30-1: 4% SBECD, 0.6 mg/mL BM
642 min
Composition 30-2: 4% SBECD, 0.6 mg/mL BM, 0.2% LMWP
707 min
Composition 30-3: 4% SBECD, 0.6 mg/mL BM, 1% LMWP
789 min
Composition 30-4: 4% SBECD, 0.2% LMWP, 0.6 mg/mL BM
673 min
Composition 30-5: 4% SBECD, 1% LMWP, 0.6 mg/mL BM
729 min
[0128] The results show that LMWP increases the stability of BM in a solution of BM and SBECD. The results also show that the stabilizing effect of LMWP is larger if this compound is added to the pre-prepared mixture of BM and SBECD (Composition 30-3 vs. 30-5, and composition 30-2 vs. 30-4 respectively).
Example 31
Bendamustine Chemical Stability in Plasma
[0129] Heparinized human plasma was spiked, 20 μL into 780 μL of plasma, with the following bendamustine (BM) compositions:
[0000] Control: 0.6 mg/mL Bendamustine hydrochloride (BM) in water, prepared by dissolving BM in water.
Composition 31-A: 0.6 mg/mL BM in 4% SBECD, prepared by dissolving BM in 4% (w/w) solution of SBECD in water
Composition 31-B: 0.6 mg/mL BM in 8% SBECD, prepared by dissolving BM in 8% (w/w) solution of SBECD in water
Composition 31-C: 0.6 mg/mL BM in 20% SBECD, prepared by dissolving BM in 20% (w/w) solution of SBECD in water
Composition 31-D: 0.6 mg/mL BM in 40% SBECD, prepared by dissolving BM in 40% (w/w) solution of SBECD in water
Composition 31-1: 0.6 mg/mL BM in 4% SBECD and 3% PI2080, prepared by dissolving BM in 4% (w/w) solution of SBECD in water, and adding PI2080
Composition 31-2: 0.6 mg/mL BM in 8% SBECD and 3% PI2080, prepared by dissolving BM in 8% (w/w) solution of SBECD in water, and adding PI2080
Composition 31-3: 0.6 mg/mL BM in 20% SBECD and 3% PI2080, prepared by dissolving BM in 20% (w/w) solution of SBECD in water, and adding PI2080
Composition 31-4: 0.6 mg/mL BM in 40% SBECD and 3% PI2080, prepared by dissolving BM in 40% (w/w) solution of SBECD in water, and adding PI2080
[0130] The concentration of bendamustine in plasma after spiking was initially 0.015 mg/mL. The spiked plasma samples were incubated at 37° C. A sample of 50 μL was periodically withdrawn from spiked plasma, and transferred into 200 μL of 100 mM HCl solution in acetonitrile, mixed and centrifuged. 50 μL of the supernatant was diluted 20 times with 95% acetonitrile, then 20 μL of diluted samples were separated on Waters SymmetryShield RP18 3.5 μm column (4.6×50 mm) using gradient of acetonitrile (0.1% TFA) in water (0.1% TFA), flow 1.5 mL/min. Peak detection was performed by means of fluorescence detection with extinction at 327 nm and emission at 420 nm. The area of the peak of Bendamustine was used to evaluate the rate of drug decomposition in the first order kinetics model. The results expressed as decomposition half times (T1/2) are presented in Table 18 below.
[0000] TABLE 18 T½ in Formulation plasma Control: 0.6 mg/mL BM 123 min Composition 31-A: 0.6 mg/mL BM, 4% SBECD 134 min Composition 31-B: 0.6 mg/mL BM, 8% SBECD 137 min Composition 31-C: 0.6 mg/mL BM, 20% SBECD 174 min Composition 31-D: 0.6 mg/mL BM, 40% SBECD 242 min Composition 31-1: 0.6 mg/mL BM, 4% SBECD, 3% PI2080 182 min Composition 31-2: 0.6 mg/mL BM, 8% SBECD, 3% PI2080 251 min Composition 31-3: 0.6 mg/mL BM, 20% SBECD, 3% 297 min PI2080 Composition 31-4: 0.6 mg/mL BM, 40% SBECD, 3% 302 min PI2080
The results show that PI2080 increases stability of BM in plasma.
[0131] The examples and representative species described herein are for illustrative purposes and are not meant to limit the scope of the invention. From the foregoing description, it will be apparent that variations and modifications may be made to the invention described herein to adopt it to various usages and conditions. Such embodiments are also within the scope of the following claims.
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The present invention is directed to pharmaceutical compositions comprising: (a) bendamustine, (b) a charged cyclopolysaccharide, and (c) a stabilizing agent having a charge opposite to that of the cyclopolysaccharide. Such composition provides unexpectedly desirable stability in reactive environments such as plasma, coupled with unexpectedly desirable anticancer activity. Such compositions are suitable for injection or infusion into patients in need for treatment with bendamustine.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a noise reduction apparatus for a digital camera, and in particular to noise reduction in long time exposure operations such as night-view imaging and astrophotography imaging.
[0003] 2. Description of the Related Art
[0004] When a long time exposure operation is carried out in a digital camera which has an imaging device such as a CCD, there is a problem that a dark output by a certain picture element of the imaging device, becomes bigger than that of other picture elements due to the influence of the dispersion of dark current in each picture element on the imaging device, so that the dark output by a certain picture element turns out as a bright point in a dark area on the image.
[0005] Even for an optical black output, which is obtained when a partly shaded CCD is used, the dark current component is not able to be cut and removed, so that an image having generally increased brightness and damaged image quality is obtained.
[0006] Japanese unexamined patent publication (KOKAI) No. 2000-209506 discloses a noise reduction apparatus that images normally (normal exposure operation), stores the time length of an exposure operation, immediately exposes again while shading the CCD (the dark exposure operation) for the same length of time as the time length of the normal exposure operation, and reduces noise components by taking away a dark output obtained by the dark exposure operation from a normal output obtained by the normal exposure operation, for every picture element. In other words canceling the dark output of each picture element in the normal exposure operation by using the dark output of each picture element in the dark exposure operation, is the usual method of reducing the fixed pattern noise occurring due to dispersion of dark current in each picture element.
[0007] However, the above-discussed conventional noise reduction method does not consider the rise in temperature of the CCD associated with the time length of the dark exposure operation which is carried out immediately after the normal exposure operation. Dark current occurs due to heat, and the temperature of a CCD goes up according to the time length of the exposure operation.
[0008] Accordingly, an error results between the dark current component Im, obtained from the normal exposure operation, and the dark current component Id, obtained from the dark exposure operation, for every picture element. That is to say, the temperature of the CCD further goes up in the dark exposure operation, because the CCD has been used continuously from the normal exposure operation, so that the dark current in the dark exposure operation is more than the dark current in the normal exposure operation, corresponding to the rise in temperature of the CCD (Im<Id). The images obtained by taking away the dark current component Id, obtained from the dark exposure operation, from the normal output obtained by the normal exposure operation, create a condition where the dark output is pulled too much, accordingly the color balance of the image collapses and the brightness decreases (under exposure).
SUMMARY OF THE INVENTION
[0009] Therefore, an object of the present invention is to provide a noise reduction apparatus for a digital camera which uses an imaging device such as a CCD, that can reduce noise in a long time exposure image, caused by the dispersion of dark current in each picture element of the CCD. The noise-reduction apparatus must consider the temperature rise of the CCD associated with continuous use.
[0010] According to the present invention, a noise reduction apparatus for a digital camera which has an imaging device for imaging a photographic subject, comprises a dark exposure processor, a representative value calculating processor, a ratio calculating processor, a noise component calculating processor, and a noise reducing processor.
[0011] The dark exposure processor carries out a specified number of dark exposure operations to obtain the same specified number of dark output values for each picture element of the imaging device, in which the photographic subject is imaged, under the condition where the imaging device is shaded, after a normal exposure operation in which the photographic subject is imaged.
[0012] The representative value calculating processor calculates a representative value for each dark exposure operation, based on the dark output values.
[0013] The ratio calculating processor calculates a ratio of each representative value.
[0014] The noise component calculating processor calculates noise components caused by the dark current in each picture element of the imaging device in the normal exposure operation, on the basis of the ratio.
[0015] The noise reducing processor reduces the noise components from respective output values of each picture element in the normal exposure operation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which:
[0017] FIG. 1 is a block diagram of the digital camera of this embodiment;
[0018] FIG. 2 is a flowchart showing the normal exposure operation and the dark exposure operation;
[0019] FIG. 3 is a timing chart showing the normal exposure operation and the first and second dark exposure operations;
[0020] FIG. 4 is a timing chart showing the normal exposure operation and the dark exposure operation; and
[0021] FIG. 5 is a graph showing the change of the dark current over time.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The present invention is described below with reference to the embodiments shown in the drawings. FIG. 1 shows a block diagram of a digital camera of this embodiment.
[0023] The digital camera 1 which is a single-lens reflex camera, having mount pins 12 and 13 , a CPU 31 , and an iris driving circuit 32 . An interchangeable lens 11 is connected with electric circuits of the digital camera 1 , through the mount pins 12 and 13 . A lens barrel of the interchangeable lens 11 has a front lens 14 , a rear lens 15 , an iris 16 , and a lens control circuit 17 . The iris 16 is set between the front lens 14 and the rear lens 15 . Focusing is carried out by moving the front and rear lenses 14 and 15 along an optical axis LX and is controlled by the lens control circuit 17 . The lens control circuit 17 is controlled by control signals which are transmitted from the CPU 31 through the mount pin 12 . The iris 16 is controlled by control signals which are transmitted from the iris driving circuit 32 through the mount pin 13 , in such a way that a degree of opening of the iris 16 is adjusted. The iris driving circuit 32 is controlled by the CPU 31 .
[0024] The digital camera 1 has a quick return mirror 21 in line with the optical axis LX of the front and rear lenses 14 and 15 . The quick return mirror 21 can be changed between an inclined down position which is depicted, and a level up position which is above the inclined position.
[0025] The digital camera 1 has a focusing glass 22 above the quick return mirror 21 in the level condition, a pentagonal prism 23 above the focusing glass 22 , and an ocular lens 24 of a view finder at the rear of the pentagonal prism 23 (the opposite side of the interchangeable lens 11 ).
[0026] The digital camera 1 has a shutter 25 at the rear of the quick return mirror 21 , an infrared cut off filter 26 and an optical low-pass filter 27 at the rear of the shutter 25 . A CCD (an imaging device) 33 is located at the rear of the optical low-pass filter 27 . Accordingly, the quick return mirror 21 , the shutter 25 , the infrared cut off filter 26 , the optical low-pass filter 27 , and the CCD 33 are in line with the optical axis LX of the front and rear lenses 14 and 15 .
[0027] The digital camera 1 has a mirror driving circuit 34 and a shutter driving circuit 35 . The rotation of the quick return mirror 21 is driven by the mirror driving circuit 34 . The opening and closing action of the shutter 25 is driven by the shutter driving circuit 35 . Further, the mirror driving circuit 34 and the shutter driving circuit 35 are controlled by the CPU 31 .
[0028] The quick return mirror 21 is usually in the inclined position, so that the light which enters the changeable lens 11 is guided to the pentagonal prism 23 by the quick return mirror 21 . At this time, the shutter 25 is closed, so that the light path toward the CCD 33 from the changeable lens 11 is blocked by the shutter 25 .
[0029] During the imaging process, the quick return mirror 21 is rotated upward by the mirror control circuit 34 , so that the quick return mirror 21 is leveled. The shutter 25 is opened by the shutter driving circuit 35 corresponding to the rotation of the quick return mirror 21 , so that the light which passes through the changeable lens 11 is guided to the light-receiving surface of the CCD 33 . An image obtained through the front and rear lenses 14 and 15 , is formed on the light-receiving surface of the CCD 33 , so that imaging signals corresponding to the image are formed by the CCD 33 .
[0030] The digital camera 1 has a DSP (Digital Signal Processor) 40 , an AF (Auto Focus) sensor 52 , a photometric sensor 53 , an operation switch 54 , and a setting indicating apparatus 55 . The lens control circuit 17 , the iris driving circuit 32 , the DSP 40 , the AF sensor 52 , the photometric sensor 53 , the operation switch 54 , and the setting indicating apparatus 55 are connected to the CPU 31 , and are controlled by the CPU 31 , so that the CPU 31 controls the action of the changeable lens 11 which is mounted on the digital camera 1 , and also the digital camera 1 , generally.
[0031] In this embodiment, a dark exposure operation is carried out in addition to the normal exposure operation when the digital camera 1 images a photographic subject for a long time exposure operation which is defined as an exposure operation that has an exposure time over a specified time (a first and second standard time). In this embodiment, a normal exposure operation is defined as an operation where the digital camera images the photographic subject normally, and a dark exposure operation is defined as an operation where the digital camera obtains an image while shading the CCD 33 .
[0032] The first standard time is 60 seconds, and the second standard time is 1 second.
[0033] The dark exposure operation is carried out one time or two times depending on the time length of the normal exposure operation (the normal exposure time Tv), and the first and second standard times.
[0034] The DSP 40 is a control circuit for controlling the exposure operation of the CCD 33 and for processing the image data obtained by the exposure operation. Therefore, the DSP 40 runs the image processes for noise reduction from the data obtained from the normal exposure operation. The noise reduction processes are carried out on the basis of the image data etc. obtained during the normal exposure operation and during the dark exposure operation, both of which are controlled by the CPU 31 .
[0035] The digital camera 1 has a memory 41 which has sufficient capacity to store the digital image data corresponding to images of the photographic subject in the normal exposure and the first and second dark exposure operations, and is connected to the DSP 40 . The memory 41 stores a normal exposure time Tv, and first and second standard times which are used for comparison with the length of the normal exposure time Tv.
[0036] The digital camera 1 has a PPG (Programmable Pulse Generator or Pulse Pattern Generator) circuit 37 , a CCD driving circuit 38 , and an A/D (Analogue/Digital) converter 39 . The PPG circuit 37 is connected with the DSP 40 , so that the PPG circuit 37 generates various pulse signals according to the DSP 40 . The CCD driving circuit 38 is driven on the basis of these various pulse signals, so that the action of the CCD 33 is controlled by the CCD driving circuit 38 . That is, the imaging signals which are read out from the CCD 33 , are converted to digital signals by the A/D converter 39 , and are subjected to specified image processes by the DSP 40 .
[0037] An AFE (Analogue Front End) 36 is composed of the PPG circuit 37 , the CCD driving circuit 38 , and the A/D converter 39 . The AFE 36 outputs a vertical synchronous signal Vd to the CCD 33 with a first or a second cycle, every stated period. The start of the exposure operation, the termination of the exposure operation, and the reading of the data obtained in the exposure operation are carried out according to the vertical synchronous signal Vd and the drive pulse for transferring electric charge.
[0038] The first cycle is shorter than the second cycle. The first cycle is 5 ms. The second cycle is 168.3 ms which is equal to the time needed for the exposure data for one field to be read out.
[0039] The vertical synchronous signal Vd is output with the first cycle except during the normal exposure operation, the dark exposure operations, and the reading of the exposure data, because the response speed corresponding to the setting of the AFE 36 etc. should be high, and because the image which is indicated should be changed with proper timing for the through image.
[0040] The vertical synchronous signal Vd is output with the second cycle during the normal exposure operation, the dark exposure operations, and the reading of the exposure data.
[0041] A noise reduction apparatus relating to the present invention is composed of the CPU 31 , the AFE 36 , and the DSP 40 .
[0042] The digital camera 1 has a monitor interface 42 , a card interface 43 , and a PC interface 44 . The monitor interface 42 , the card interface 43 , and the PC interface 44 are connected to the DSP 40 and are controlled by the DSP 40 .
[0043] The digital camera 1 has an LCD (Liquid Crystal Display) driving circuit 45 , a backlight 46 , an LCD device 47 , a card connector 48 , a PC connector 49 , a video output driving circuit 50 , and a video output terminal 51 .
[0044] The monitor interface 42 is connected with the backlight 46 and the LCD device 47 through the LCD driving circuit 45 , and is connected with the video output terminal 51 through the video output circuit 50 . The LCD driving circuit 45 is controlled on the basis of the image data read out from the memory 41 , so that the image corresponding to the image data is indicated on the LCD device 47 . The image data is converted to the specified format by the video output driving circuit 50 , so that the converted image data is output to external output devices which are not depicted, through the video output terminal 51 .
[0045] The card interface 43 is connected with the card connector 48 , and the PC interface 44 is connected with the PC connector 49 . The card connector 48 can be fixed to the IC memory card which can store image data etc. and is not depicted. The PC connector 49 can be connected to a personal computer which is not depicted.
[0046] The AF sensor 52 and the photometric sensor 53 are connected with the CPU 31 . The AF sensor 52 measures the focus adjustment condition of the front and rear lenses 14 and 15 . The photometric sensor 53 carries out the photometry to automatically decide the degree of opening of the iris 16 during the normal exposure operation and the electric charge accumulation time (the time length of the normal exposure operation).
[0047] The operation switch 54 and the setting indicating apparatus 55 are connected with the CPU 31 . The operation switch 54 has a photometric switch and a release switch etc. The digital camera 1 has a release button which is not depicted. The photometric switch is turned to the on state when the release button is half way depressed. When the photometric switch is in the on state, the photometry is carried out by the photometric sensor 53 . The shutter release switch is tuned to the on state when the release button is fully depressed. And, the shutter 25 is opened and closed, so that the CCD 33 is exposed, and the CCD 33 generates imaging signals corresponding to the image of the photographic subject. The setting indicating apparatus 55 has an LCD device which indicates the various settings of the digital camera 1 .
[0048] Next, the flow of the normal exposure operation and the dark exposure operations is explained (see FIGS. 2 to 4 ). FIG. 3 shows a timing chart for the case where the normal exposure time Tv is longer than the first standard time. FIG. 4 shows a timing chart for the case where the normal exposure time Tv is longer than the second standard time and is shorter than or equal to the first standard time.
[0049] The horizontal axes of FIGS. 3 and 4 represent time. FIGS. 3 and 4 show the timings where the vertical synchronous signal Vd is output and where pixel data accumulated by the CCD 33 during a normal exposure operation and a dark exposure operation, is read in, corresponding to the pulse input (the release sequence) at the start and termination of the long time exposure operation.
[0050] The flowchart in FIG. 2 shows the action of the DSP 40 controlled by the CPU 31 after the power switch (not depicted) is turned on.
[0051] The flow starts in step S 11 . It is judged whether the release switch is in the on state by the operator, in step S 12 . When the release switch is in the on state (T 11 in FIG. 3 , and T 21 in FIG. 4 ), the normal exposure operation is started (T 12 in FIG. 3 , and T 22 in FIG. 4 ), in step S 13 .
[0052] The time length of the normal exposure operation (the normal exposure time Tv) which is the period from T 12 to T 13 in FIG. 3 is manually set by the operator or is automatically set by the photometry before the release switch is turned to the on state. When the operator manually sets the normal exposure time Tv with the bulb exposure, the length of time during the on state of the release switch is controlled by the operator.
[0053] Immediately after the normal exposure operation is terminated (T 13 in FIG. 3 , and T 23 in FIG. 4 ), the operation mode of the AFE 36 is changed from a first mode for the exposure operation, to a second mode for the reading of the data obtained in the exposure operation, from the vertical synchronous signal output point (T 14 in FIG. 3 , and T 24 in FIG. 4 ).
[0054] The first mode for the exposure operation of the AFE 36 is the operation mode where electric charge signals, which occur in the imaging device, due to light striking the light-receiving surface of the imaging device and forming the electric charge, are accumulated.
[0055] The second mode for reading of the data obtained in the exposure operation of the AFE 36 is the operation mode where accumulated electric charge is transferred from a receiving-unit in the imaging device to a transferring-unit in the imaging device; the transferring-unit is driven by the transferring-drive pulse signals (not depicted); and the electric charge from the imaging device is gradually read.
[0056] In FIG. 3 , the normal exposure time is strictly from point T 12 to point T 14 , however during the short time from point T 13 to point T 14 , the exposure operation under the condition of shading of the CCD 33 , is carried out, so that the normal exposure time is actually from point T 12 to point T 13 . Similarly in FIG. 4 , the normal exposure time is strictly from point T 22 to point T 24 , however during the short time from point T 23 to point T 24 , the exposure operation under the condition of shading of the CCD 33 , is carried out, so that the normal exposure time is actually from point T 22 to point T 23 .
[0057] After the operation mode of the AFE 36 is changed to the second mode for reading of the data obtained in the exposure operation (T 15 in FIG. 3 , and T 25 in FIG. 4 ), the exposure data of the normal exposure operation is read for every field, or the reading of the electric charge that was accumulated in each picture element of the CCD 33 for every field, is carried out.
[0058] In the first field, the exposure data of the normal exposure operation is read in for 168.3 ms from point T 15 in FIG. 3 or point T 25 in FIG. 4 . In the second field, the exposure data of the normal exposure operation is read in for 168.3 ms from a point which is 168.3 ms passed point T 15 in FIG. 3 or point T 25 in FIG. 4 .
[0059] In the normal exposure operation, accumulation of the electric charge is carried out under the condition that the CCD 33 receives light from the photographic subject, so that the accumulated electric charge is composed of the accumulated electric charge corresponding to the light from the photographic subject, and the accumulated electric charge corresponding to the dark current of the CCD 33 . In other words, the accumulated electric charge is the sum of the accumulated electric charge corresponding to the light from the photographic subject, and the accumulated electric charge corresponding to the dark current of the CCD 33 .
[0060] When the reading in the accumulated electric charges in the first and second fields is terminated (T 16 in FIG. 3 , and T 26 in FIG. 4 ), the length of the normal exposure time Tv is stored in the digital camera 1 in step S 14 , so that the dark exposure operation is carried out.
[0061] The number of dark exposure operations, and whether or not the dark exposure operation is carried out, are judged according to the length of the normal exposure time Tv. The judgment is carried out according to the first and second standard times which are stored in the memory 41 in advance, and the length of the normal exposure time Tv.
[0062] In step S 15 , it is judged whether or not the length of the normal exposure time Tv is longer than the first standard time (60 sec). When the length of the normal exposure time Tv is longer than 60 sec, the dark exposure operation is carried out two times (step S 16 -S 19 in FIG. 3 ).
[0063] When the length of the normal exposure time Tv is shorter than or equal to 60 sec, it is judged whether or not the length of the normal exposure time Tv is longer than the second standard time (1 sec). When the length of the normal exposure time Tv is longer than 1 sec, the dark exposure operation is carried out one time (step S 21 -S 22 in FIG. 4 ).
[0064] This is because there is little temperature rise of the CCD 33 associated with the time length of the dark exposure operation, even when using the noise reduction method in the prior art, where the dark output value due to the dark current at the time of the normal exposure operation is calculated from the dark output value due to the dark current in one dark exposure operation, in the case where the normal exposure time is comparatively short, for example from 1 sec to 60 sec.
[0065] When the length of the normal exposure time Tv is shorter than or equal to 1 sec, the dark exposure operation is not carried out. This is because a dark current has little influence on the dark output value for a normal exposure time, which is comparatively short, for example below 1 sec.
[0066] The case where the dark exposure operation is carried out twice is explained below. In step S 16 , the first dark exposure operation is started (T 16 in FIG. 3 ). The first dark exposure operation is terminated (T 17 in FIG. 3 ), after only half of the normal exposure time Tv. That is to say, half the distance from point T 12 to point T 13 which is the normal exposure time Tv, is equal to the distance and therefore the time from point T 16 to point T 17 .
[0067] After the first dark exposure operation, the exposure data of the first dark exposure operation is read for every field, or the reading of the electric charge that has accumulated in each picture element of the CCD 33 for every field is carried out (T 17 in FIG. 3 ).
[0068] In the first dark exposure operation, the imaging and thereby the accumulating of the electric charge is carried out under the condition that the CCD 33 does not receive light from the photographic subject, so that the accumulated electric charge is composed of the accumulated electric charge corresponding to the dark current of the CCD 33 .
[0069] When the reading of the accumulated electric charge for the first and second fields is terminated (T 18 in FIG. 3 ), the second dark exposure operation is carried out.
[0070] Next, in step S 17 , the second dark exposure operation is started (T 18 in FIG. 3 ). The second dark exposure operation is terminated (T 19 in FIG. 3 ), after half of the normal exposure time Tv. That is to say, half the distance from point T 12 to point T 13 which is the normal exposure time, is equal to the distance and therefore the time from point T 18 to point T 19 , similar to the first dark exposure operation.
[0071] After the second dark exposure operation, the exposure data of the second dark exposure operation is read for every field, or the reading of the electric charge that has accumulated in each picture element of the CCD 33 for every field is carried out (T 19 in FIG. 3 ).
[0072] In the second dark exposure operation, the imaging and thereby the accumulating of the electric charge is carried out under the condition that the CCD 33 does not receive light from the photographic subject, so that the accumulated electric charge is composed of the accumulated electric charge corresponding to the dark current of the CCD 33 , as in the first dark exposure operation.
[0073] When the reading of the accumulated electric charges in the first and second fields is terminated (T 20 in FIG. 3 ), a mean value, which corresponds to the integration value Sd of the dark current, of the data that is output from each picture element due to the dark current in the normal exposure operation is calculated on the basis of mean values, which respectively correspond to the integration values S2 and S3 of the dark current, of the data that is output from each picture element due to the dark current in the first and second dark exposure operations, in step S 18 .
[0074] In step S 19 , an output value which is deducted from the influence of the dark current of each picture element in the normal exposure operation, in other words which is reduced noise components in the normal exposure operation, is calculated on the basis of the calculated mean value. In step S 23 , the flow is terminated. The method in steps S 18 and S 19 is described later.
[0075] Next, the case where the dark exposure operation is carried out once is explained. After step S 20 , the dark exposure operation is started (T 26 in FIG. 4 ), in step S 21 . The dark exposure operation is terminated (T 27 in FIG. 4 ), after the normal exposure time Tv. That is to say, the length of time corresponding to the distance between point T 22 and point T 23 , which is the normal exposure time Tv, is equal to the distance and therefore the time between point T 26 and point T 27 .
[0076] After the dark exposure operation, the exposure data of the dark exposure operation is read for every field, or the reading of the electric charge that has accumulated in each picture element of the CCD 33 for every field, is carried out (T 27 in FIG. 4 ).
[0077] In the dark exposure operation, the imaging and thereby the accumulating of the electric charge is carried out under the condition that the CCD 33 does not receive light from the photographic subject, so that the accumulated electric charge is composed of the accumulated electric charge corresponding to the dark current of the CCD 33 .
[0078] When the reading of the accumulated electric charges in the first and second fields is terminated (T 28 in FIG. 4 ), an output value which is deducted from the influence of the dark current of each picture element in the normal exposure operation, in other words which is reduced noise components in the normal exposure operation, is calculated, in step S 22 . In step S 23 , the flow is terminated.
[0079] The dark output value obtained by using the dark current in the dark exposure operation is regarded as equal with the dark output value obtained by using the dark current in the normal exposure operation, in the calculating method of step S 22 .
[0080] When the dark exposure operation is not carried out, the flow is terminated in step S 23 , after step S 20 .
[0081] The calculation for reducing the dark output value of the dark current for the normal exposure data in steps S 18 and S 19 in the case where the dark exposure operations are carried out twice, is explained.
[0082] It can be assumed that the normal exposure operation, the first dark exposure operation, and the second dark exposure operation are continuously carried out. This is because it can be assumed that the normal exposure time (T 12 ˜T 13 in FIG. 3 ), the first dark exposure time (T 16 ˜T 17 in FIG. 3 ), and the second dark exposure time (T 18 ˜T 19 in FIG. 3 ) are sufficiently longer than the time (T 17 ˜T 18 in FIG. 3 ) etc. required to read the accumulated electric charges.
[0083] Accordingly, the increase in the dark current corresponding to the rise in temperature of the CCD 33 over time in the case where the normal exposure operation, the first dark exposure operation, and the second dark exposure operation are continuously carried out, is like that shown in FIG. 5 . The horizontal axis of FIG. 5 represents time and the vertical axis of FIG. 5 represents the value of the dark current.
[0084] The integration value of the dark current for a certain time section corresponds to the mean value of the dark outputs from each picture element of the CCD 33 for that certain time section.
[0085] In FIG. 5 , the normal exposure time Tv is given by the time between t0 and t2, which is equal to the time between T 12 and T 13 in FIG. 3 . Similarly, in FIG. 5 , the first dark exposure time is given by the time between t2 and t3, which is equal to the time between T 16 and T 17 in FIG. 3 . Similarly, in FIG. 5 , the second dark exposure time is given by the time between t3 and t4, which is equal to the time between T 18 and T 19 in FIG. 3 .
[0086] In FIG. 5 , the point where only half of the normal exposure time Tv has passed is defined as t1.
[0087] The integration values of the dark current which respectively correspond to the mean values of the dark output values that are output from each picture element of the CCD 33 for the time between t0˜t1, t1˜t2, t2˜t3, t3˜t4, t4˜t5, and t5˜t6, are defined as S0, S1, S2, S3, S4, and S5.
[0088] The electric charge corresponding to only the dark current is accumulated in the first and second dark exposure operations. Accordingly, the integration value of the dark current in the first dark exposure operation S2 is obtained on the basis of the output values which are the same as the dark output values and which are output from each picture element of the CCD 33 in the first dark exposure operation. Similarly, the integration value of the dark current in the second dark exposure operation S3 is obtained on the basis of the output values which are the same as the dark output and which are output from each picture element of the CCD 33 in the second dark exposure operation.
[0089] However, because the electric charge corresponding to not only the dark current, but also the light from the photographic subject is accumulated in the normal exposure operation, the integration value of the dark current in the normal exposure operation Sd (=S0+S1) can not be directly obtained on the basis of output values which are output from each picture element of the CCD 33 in the normal exposure operation. Accordingly, the integration value Sd needs to be obtained from the integration values S2 and S3.
[0090] When the increase curve of the dark current is a linear shape, as shown in FIG. 5 , the integration values S0, S1, S2, and S3 have the following relationship (S0<S1<S2<S3):
S1 ≈ S2 × ( S2 ÷ S3 ) S0 ≈ S1 × ( S1 ÷ S2 ) ( 1 ) = S2 × ( S2 ÷ S3 ) × ( S2 ÷ S3 ) ( 2 )
[0091] The integration value Sd has the following relationship on the basis of equations (1) and (2).
Sd = S0 + S1 ≈ S2 × ( S2 ÷ S3 ) × ( S2 ÷ S3 ) + S2 × ( S2 ÷ S3 ) = S2 × { ( S2 ÷ S3 ) × ( S2 ÷ S3 ) + ( S2 ÷ S3 ) } ( 3 )
[0092] The integration value of the dark current Sd is calculated by multiplying the integration value S2 by a coefficient which is calculated on the basis of the ratio of the integration values S2 and S3. The equation (3) is applied to the calculation of the dark current of each picture element, so that the calculation of the dark current component in each picture element data, that is to be removed, is decided.
[0093] The output value of a particular picture element in the normal exposure operation is defined as Pm, similarly the dark output value of the particular picture element in the first dark exposure operation is defined as Pd1. The output value Pm′ of the particular picture element for a normal exposure operation, where the dark output by the dark current, or the noise component, has been removed, is given by the following equation.
Pm′=Pm−Pd 1×{( S 2÷ S 3)×( S 2 ÷S 3)+( S 2 ÷S 3)} (4)
[0094] If equation (4) is applied to all the picture elements, it becomes possible to calculate the output value for each picture element, where the dark output component (the noise component) of the dark current, in the normal exposure operation, has been removed.
[0095] Accordingly, the mean values, which respectively correspond to the integration values S2 and S3, of the dark outputs in the first and second dark exposure operations, are calculated in steps S 16 and S 17 in FIG. 2 , so that the mean value, which corresponds to the integration value Sd, of the dark outputs in the normal exposure operation, is calculated in step S 18 in FIG. 2 on the basis of the integration values S2 and S3. Then the output value of each picture element, where the dark output component of the dark current, is removed, is calculated in step S 19 in FIG. 2 .
[0096] Furthermore, in this embodiment, it is explained that the integration value of the dark current corresponds to the mean value of the dark output values that are output from each picture element of the CCD 33 , however the integration value of the dark current may correspond to the total value of the dark output values that are output from each picture element of the CCD 33 .
[0097] The mean or total value of the dark output values, for each dark exposure operation, may be determined on the basis of some of the picture elements of all the picture elements of the CCD 33 .
[0098] For simplicity of calculation, the lengths of the first and second dark exposure times are half of the length of the normal exposure time, for carrying out the calculation of the dark current component and the reduction of the dark output value, however the length of the dark exposure time is not limited to this.
[0099] However, if the exposure times were different from the above exposure times, another set of calculation equations whereby the dark output value of the dark current in the normal exposure operation is calculated on the basis of two dark output values of the dark current in the first and second dark exposure operations, would be needed, and the same effect would be obtained.
[0100] The number of dark exposure operations is set at two to perform the calculation quickly. However, the number of dark exposure operations may be set to three or more, so that the accuracy of the calculation for the dark output value of the dark current in the normal exposure operation, becomes high, on the basis of the ratios of a plurality of mean values.
[0101] Furthermore, the length of the first standard time is not limited to 60 seconds, similarly the length of the second standard time is not limited 1 second.
[0102] The digital camera in this embodiment is a single-lens reflex camera, however the digital camera is not limited to this.
[0103] Although the embodiment of the present invention has been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in this art without departing from the scope of the invention.
[0104] The present disclosure relates to subject matter contained in Japanese Patent Application No. 2003-308457 (filed on Sep. 1, 2003), which is expressly incorporated herein by reference, in its entirety.
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A noise reduction apparatus of a digital camera which uses an imaging device for imaging a photographic subject, carries out a specified number of dark exposure operations, to obtain the same specified number of dark output values for each picture element of the imaging device, in which the photographic subject is imaged, under the condition where the imaging device is shaded, after a normal exposure operation in which the photographic subject is imaged. The apparatus calculates a representative value for each dark exposure operation, based on the dark output values. The apparatus calculates a ratio based on the representative values. The apparatus calculates noise components caused by the dark current in each picture element of the imaging device in the normal exposure operation on the basis of the ratio. The apparatus reduces the noise components from respective output values of each picture element, produced in the normal exposure operation.
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RELATED APPLICATION
The applicant is the inventor of the invention shown, described and claimed in utility patent application Ser. No. 09/494,448 filed Jan. 31, 2000, and entitled “METHOD AND APPARATUS FOR REMOVING ACOUSTICAL CEILING AND REPLACEMENT THEREOF WITH TEXTURED CEILING”.
BACKGROUND OF THE INVENTION
The background of the invention will be discussed in two parts.
1. Field of the Invention
This invention relates to apparatus for the process of applying a textured ceiling that includes, if necessary, the removal of acoustical ceiling, and more particularly to improved tooling providing for a faster, cleaner and less expensive process.
2. Description of the Prior Art
Textured ceilings are common in the building industry and have become quite popular during renovation and remodeling, especially during remodeling of older residences. In such instances, it is often necessary that an existing acoustical ceiling must first be removed before applying the new textured ceiling
Prior art methods of both the application of a textured ceiling, and where necessary, removal of acoustical ceiling, have been cumbersome, messy, labor extensive and time consuming. For example, the application of a textured ceiling generally is by use of compressed air guns that are extremely messy by nature. Additionally, in the removal of acoustical ceiling, common hand-held putty knifes have been used as ceiling scrapers which necessitate the use of such structures as “A” frame ladders, scaffolding, and even stilts, to reach the ceiling. Use of such ladders, scaffolding or stilts is time consuming in set-up and relocation. Further, such means are dangerous due to the necessity for working above the floor in a commonly slippery area to access the ceiling.
Additionally, the use of such conventional methods in application of a textured ceiling, and as is usually the case in renovation of older residencies, the removal of an existing acoustical ceiling, generally results in excessive contamination of the work area as well as areas adjacent to the work area. Also, the use of such conventional methods is unnecessarily labor extensive, which thus increases time for job completion. As an example, use of these conventional methods, when coupled with corresponding necessary clean up, commonly takes 3-5 days for a typical residence. The same process in accordance with the apparatus and method of the present invention commonly takes no more than one day for the typical residence.
Thus, prior art procedures are unsatisfactory in that they are comparatively inefficient, time consuming, expensive and dangerous. Accordingly, it is a feature of this invention to provide improved apparatus, and method of use thereof, for both the application of textured ceiling, and where necessary the removal of existing acoustical ceiling, that is comparatively more quick, clean, less expensive, and safer for the workers than conventional methods
SUMMARY OF THE INVENTION
The invention provides improved tooling and method of use thereof for the application of a textured ceiling, and if necessary, the removal of acoustical ceiling. Use of the tooling as described does not include the use of ladders, scaffolding or other such dangerous structures
In accordance with the invention, improved tooling having handle extension means is used to enable the user to access the ceiling while standing on the floor beneath the ceiling. In applying a textured ceiling, a spreading tool is first used to apply thin amounts of drywall “mud” to cover exposed drywall tape joints and other flaws. An application pad is then used to apply the new texture, such as a coat of drywall “mud”, to the ceiling. The texture is then spread over the ceiling as desired with the use of the spreading tool. If desired, the texture applicator can have surface means thereon for applying a design to the ceiling.
When removal of acoustical ceiling is desired, the area is first moisturized, by application of a fine mist of water, to loosen the ceiling including any clinging debris. The loosened ceiling and debris is then removed with an improved scraping tool, after which an improved ceiling brush is used to further clean the ceiling and to prepare it for readily accepting the new ceiling texture material. Both the scraping tool and ceiling brush embody handle extension means
The scraping tool, ceiling brush, spreading knife, and texture applicator are specially designed to perform their respective functions. As more completely explained below, there is provided universal mating means for easy acceptance, and replacement, of the improved tooling apparatus so as to optimize their use in performance of their respective work functions.
It is thus an aspect of the invention to provide improved tooling for application of a textured ceiling, and where desired removal of acoustical ceiling, that is comparatively more quick, clean, less expensive, and safer for the workers than conventional methods.
Other objects, features and advantages of the invention will become apparent from a reading of the specification, when taken in conjunction with the drawings, in which like reference numerals refer to like elements in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of specialized tooling in accordance with the invention assembled for use and showing the combination of the tool holder, handle bracket, tool locking means, handle bracket sleeve, and a first embodiment of the apparatus tool,
FIG. 2 is an exploded view of the specialized tooling of FIG. 1;
FIG. 3 is a partial sectional view showing the tool holder, apparatus tool, and tool locking means of FIG. 1, taken along lines 3 — 3 of FIG. 1,
FIG. 4 a is a sectional view showing positioning of the locking and release tabs for attachment and locking of the bracket sleeve to the handle bracket, taken along lines 4 — 4 of FIG. 1;
FIG. 4 b is a sectional view showing operation of the locking and release tabs for releasing the handle bracket from the bracket sleeve;
FIG. 5 is an end view of the ceiling brush, in accordance with the invention;
FIG. 6 is a back view of the ceiling brush showing the method of attachment of the brush to the brush mounting plate;
FIG. 7 is a bottom view of the ceiling brush showing the brush bristles as extending across the mounting plate;
FIG. 8 is a bottom view of the spreading knife in accordance with the invention;
FIG. 9 is a bottom view of the texture application pad;
FIG. 10 is a side view of the texture application pad of FIG. 9; and
FIG. 11 is a perspective view of an alternate embodiment of the specialized tooling in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the tooling in accordance with the invention is described while referring to designated figures of the drawings, and relates to specialized tooling for an improved process of applying a textured ceiling and, if necessary, the removal of an existing acoustical ceiling. The improved tooling and method of use provides for a faster, cleaner, less expensive and safer process.
Prior to describing the specialized tooling, the method of application of the tooling will be addressed. When applying a textured ceiling, or especially if removing an existing acoustical ceiling, best results are realized when the work area is first sufficiently isolated to protect surrounding areas, as described below, to insure a clean process with minimum escape of ceiling material, moisture, dust, etc.
When applying a textured ceiling, and after the work area is isolated from surrounding areas, the ceiling is brushed, or swept, clean with ceiling brush 16 (See FIGS. 5 - 7 ). Then, spreading knife 17 (See FIG. 8) is used to apply thin amounts of drywall “mud” to cover all ceiling tape joints and other flaws. Texture application pad 18 (See FIG. 9) is then used to apply a texture coating coat of drywall “mud” to the ceiling. In this step, pad 18 is dipped into a container of “mud” of desired consistency and then pressed firmly against the properly scraped and swept ceiling. Spreading knife 17 is then used as necessary to finish the applied texture.
Although not shown, if desired the face of application pad 18 can be provided with a pattern that can be transferred to the ceiling upon pressing of the patterned pad against the ceiling
When it is desired to remove an acoustical ceiling, the ceiling is first moistened with a fine spray or mist of water to loosen the acoustical material and any accumulated debris. It has been found satisfactory to use a high-pressure (300-psi) construction grade water hose having attached thereto a garden type adjustable spray nozzle. The nozzle is adjusted to provide a fine spray or mist that loosens the ceiling material while decreasing any contaminants, such as dust, from being blown from the ceiling.
After the acoustical material is sufficiently moistened, the ceiling is scraped with scraper tool 13 (See FIG. 1) and then swept with ceiling brush 16 to remove any remaining acoustical material and associated debris. This prepares the ceiling for accepting the new texture material as described above. After completion of the ceiling renovation, the means for protecting areas adjacent to the work area is detached, collected to contain the debris resulting from the ceiling project and removed from the work area.
Referring now to the drawings, and more particularly to FIGS. 1 and 2, there is shown, generally designated 10 , the assembled combination of the tool holder 11 , handle bracket 12 composed of two identical halves generally designated 12 a , apparatus tool 13 , tool locking knobs 14 , and handle bracket sleeve 15
Tool holder 11 is of an elongated, hollow, substantially square, both inside and outside, configuration with generally planar surfaces. Tool holder 11 can satisfactorily be constructed of stamped, bent, and welded anodized aluminum. As shown in FIG. 2, two longitudinal slots 11 a are shown in dotted lines on the underside of holder 11 for receiving the two upturned portions 13 a of tool 13 Tool 13 is positioned in holder 11 as shown in FIGS. 1 and 3 such that non-threaded holes 11 b of holder 11 match up with threaded holes 13 b of tool 13 when upturned, or curved, tool portions 13 a are fully inserted through slots 11 a . Tool 13 has two cutouts 13 d to permit insertion of upturned portions 13 a sufficiently into holder 11 to align holes 11 b and 13 b
Tool 13 is then secured to tool holder 11 , as indicated in FIG. 3, by means of threaded knobs 14 passing through non-threaded holes 11 b and securely threaded into threaded holes 13 b to thereby effect a secure and firm attachment of the tool 13 to tool holder 11 .
Tool holder 11 is secured to tool handle 20 by means of handle bracket 12 and sleeve 15 As seen in FIG. 2, handle bracket 12 is comprised of two identical halves, generally designated 12 a , each of which include semi-circular portions 12 b , hook means comprised of planar portions 12 c , 12 d , and 12 e , and finger 12 f including locking tab 12 g . When hook portions 12 e of halves 12 a are hooked onto slot 11 c of tool holder 1 , joined together as a cylindrical unit, and partially encompassed by sleeve 15 , tool holder 11 and bracket 12 become securely locked together and function as one single unit. Tool 13 has a cutout 13 c between upturned portions 13 a to permit insertion of hook portions 12 e into slot 11 c to capture holder 11 .
Handle bracket 12 can be stamped from an appropriate planar metal sheet with semi-circular portions 12 b , hook means 12 c-e , and locking tabs 12 g formed as indicated. The semi-circular portions 12 b can be formed from the planar metal sheet in a conventional manner. To form appropriate hook means, in each case, planar hook portion 12 d is bent downwardly from portion 12 c at 90 degrees in the same direction as semi-circular portion 12 b , and portion 12 e is bent rearwardly at 90 degrees from portion 12 d to be substantially parallel with portion 12 c
FIG. 12 f is stamped into the planar metal sheet with the open end, or finger tip, bent upwardly and away from the surface of the sheet to form tab 12 g . In order to function as locking means as will hereafter be explained, it is necessary that the metal composition of the sheet provides sufficient spring resiliency such that tab 12 g returns to its original position after depression and release.
Bracket sleeve 15 (See FIGS. 1, 2 , 4 a and 4 b ) is typically an aluminum tube having an inside diameter sufficient to slip over semi-circular brackets 12 a after they have been joined with tool holder 1 and collapsed to form a complete cylindrical unit. In the locking operation collapsed halves 12 a are positioned in sleeve 15 so that tabs 12 g fit into and protrude from holes 15 a , as shown in FIG. 4 a , thereby securely locking the sleeve 15 , tool holder 11 , and tool 13 into a single operational unit. To unlock the unit it is only necessary to depress tabs 12 g and disengage brackets 12 a from sleeve 15 , as indicated in FIG. 4 b . In this manner the various specialized tools of the invention may be interchanged
Sleeve 15 may be an integral portion of handle 20 of a desired length, such as to provide access to the ceiling by a user standing on the floor of the room, or may be affixed a handle of another material in any conventional manner. For instance, a handle may be extendible into various lengths by any conventional means such as sections of tubing having interlocking means such as snap-in spring tabs, or by telescoping tubes as is known in the art
As described above, ceiling brush 16 is used to sweep the acoustical debris from the ceiling. An end view of brush 16 is shown in FIG. 5, brush 16 being mounted to base plate 16 a as indicated in the back view of brush 16 shown in FIG. 6 FIG. 7 is a bottom view of brush 16 showing brush bristles extending across base plate 16 a Brush 16 has dimensions generally of 1×18 inches. Base plate 16 a is spring steel of any convenient dimensions.
After the ceiling is brushed clean and it is desired to replace the removed acoustical ceiling with a desired textured ceiling, spreading, or floating, knife 17 (see FIG. 8) is used to apply thin amounts of drywall “mud” to cover all drywall tape joints and other flaws. Spreading knife 17 is made of thin, flexible, hardened steel with dimensions of approximately 6×18 inches, 18 inches being the width of the leading edge. The thickness is generally about 0.020 inches.
After preparation of the ceiling, texture applicator 18 (FIGS. 9 and 10) is used to apply texture to the ceiling as heretofore described. Pad 18 is comprised of a metal base plate 18 a to which is added a surface pad 18 b composed of a high density, light weight, flexible foam material similar to that of the “boogie” board familiar to water sports enthusiasts. Base plate 18 a is formed of thin, flexible, hardened steel with dimensions of approximately 12×24 inches, 24 inches being the width of the leading edge. The thickness is generally about 0.020 inches. Surface pad 18 b is added to the surface of plate 18 a in any conventional manner
In the removal of an existing acoustical ceiling, the scraping tool, or blade, 13 is used. Scraping tool 13 is shown attached to tool holder 11 in FIGS. 1 and 2. Blade 13 is generally made from a plate of stiff, smooth surfaced, hardened spring steel, 6×14 inches, 14 inches being the width of the front or leading edge. The thickness of the blade is about 0.028 inches. The combination of stiff hardened material and the smooth surface of blade 13 provide for efficient scraping and removal of the moistened ceiling. After adjusting the handle length as described, the moistened acoustical ceiling is removed by scraping with tool 13 until the drywall joints and the paper of the drywall sheet are exposed. For ceilings having a different pitch, any of the above tools may be manufactured with different “strike angles”, that is, the angle of the working surface of the tool with respect to the handle as indicated by the angle α in FIGS. 5 and 10.
An adequate means for protecting areas adjacent to the work area consists of isolating the area with plastic sheeting, applied in a manner to ensure quick and easy clean up of debris. A preferred method includes first sticking sufficient lengths of masking tape, generally a two-inch strip, to select spots on the interior walls with the remainder of such strips not stuck to the wall but left hanging loose toward the floor. A sheet of plastic is then placed under the loose portions of tape and stuck against the respective exposed adhesive sides of the tapes. In order for the tape to properly hold the plastic sheeting in place it is necessary to use sufficiently lightweight sheeting since heavy plastic sheeting will lift the adhesion of the sheeting from the tape. After attachment to the respective tape portions, the remainder of the plastic sheet is placed to lie upon and cover the floor. As required, additional sheets of plastic are cut to fit the dimensions of the other wall surfaces and likewise attached until the protective envelope is completed. The tape portions covering the floor, and other areas as required, such as each corner where plastic has been taped to the wall, are reinforced as necessary to provide the desired protection.
In accordance with the invention there has been shown and described improved apparatus, and method of use thereof, for the application of a textured ceiling, and if necessary the removal of an acoustical ceiling. It is to be understood that various other adaptations and modifications may be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention. For instance, FIG. 11 shows an embodiment omitting the bracket 12 a , sleeve 15 being welded or otherwise connected directly to holder 11
While there has been shown and described a preferred embodiment, the invention is not limited to the specific form as described and illustrated but rather limited only by the literal interpretation of the claims herein.
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A unique, clean, fast and low cost method for the application of a textured ceiling, and if necessary the removal of acoustical ceiling, including improved tooling that does not include the use of ladders, scaffolding or other such dangerous structures. The tooling includes a unique changeable tool holder for readily exchanging the tools required, such as a ceiling scraping tool, ceiling brush, texture application pad, and spreading blade. Improved means for isolating the work area are disclosed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stopper for stopping the rotation of a bobbin case in a lock stitch sewing machine.
2. Description of the Prior Art
In a known vertical full rotation shuttle device, a bobbin case retaining member is fixed on a sewing machine body in order to arrest the rotation of a bobbin case. After a needle thread and a bobbin thread are tied to make a loop, the loop must pass through the retaining member and the contacting surface part of the bobbin case. The mutual contact pressure at this contacting position is unstable, and the tension of the needle thread fluctuates, which results in uneven thread tightening.
This problem conventionally has been solved by an opener mechanism, wherein when the needle thread passes through the contact position, the bobbin case is slightly moved angularly by a collision piece in a direction opposite to the direction of rotation of the loop taker, and a free space is formed for a moment in the contact position, so that the needle thread may pass through the space smoothly. In this method, however, since the bobbin case is angularly moved by the collision piece so that a free space may be produced between the retaining member and the bobbin case, noise due to the collision of the collision piece and the bobbin case, and of the retaining member and the bobin case cannot be avoided.
It is an object of the present invention to provide a stopper device for lock stitch sewing machine which is capable of passing the needle thread smoothly and quietly between the bobbin case and the retaining member.
SUMMARY OF THE INVENTION
In order to fulfill the objective mentioned above, in a stopper device for a lock stitch sewing machine according to this invention, a contacting face of a retaining member is moved in the downstream direction with respect to the rotary running direction of the loop taker from the bobbin case contacting face when the needle thread loop passes between the bobbin case contacting face and the contacting face of the retaining member, in order to facilitate the passing of the needle thread loop, and a drive means is provided to return the retaining member in the upstream direction.
According to this invention, when the needle thread loop passes between the bobbin case contacting face and the contacting face of the retaining member, the retaining member is moved in the downstream direction while the retaining member is kept in contact with the contacting face of the bobbin case with the needle thread held therebetween at a small pressure, so that the needle thread loop may pass smoothly without the generation of noise.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing, in a simplified form, an embodiment of the present invention;
FIG. 2 is a perspective view of part of another embodiment of the invention; and
FIG. 3 is a perspective view of part of another embodiment according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, embodiments of the invention are described below.
FIG. 1 is a plan view showing a simplified form of one embodiment. A loop taker 2 is fixed on a rotary shaft 1 having a horizontal axis, and a bobbin case 3 is inserted in the loop taker 2. A bobbin case contacting face 5 is defined by a recess 4 formed in the outer end face of the bobbin case 3. A rotation retaining member 6 is supported by a support member 8 for movement in an upstream direction (to the right as viewed in FIG. 1) and a downstream direction (to the left as viewed in FIG. 1) with respect to the rotary running direction 7 of the loop taker 2, in relation to the contacting face 5. Thus, the retaining member 6 can be moved reciprocally in the directions of arrow 9. A protuberance 11 formed on the retaining member 6 extends into the recess 4, and a contacting face 10 of the retaining member is formed to be directed upstream with respect to the rotary running direction 7. When the bobbin case contact face 5 and the contacting face 10 are in mutual contact, the bobbin case 3 is held stationary regardless of the rotation of the loop taker 2. Drive shaft 1 is affixed to a bevel gear 12 which is engaged with another bevel gear 13. The bevel gear 13 is fixed on a rotary shaft 14 which is linked to a drive source.
An end of the retaining member 6 is a follower 15 which abuts against the cam surface of an eccentric cam 16. A spring 17 pushes the retaining member 6 so that the follower 15 will contact with the cam surface of the cam 16. The cam 16 is driven by a drive shaft 18. The drive shaft 18 has a bevel gear 19 mounted thereon, and this bevel gear 19 meshes with another bevel gear 20 fixed on the rotary shaft 14. The drive shaft 18 responsible for rotation of the cam 16 rotates at a speed equal to half the speed of the drive shaft 1 which drives the loop taker 2, due to the reduction ratio of bevel gears 12, 13, 19, 20.
When a needle thread loop passes between the bobbin case contacting face 5 and contacting face 10, the cam 16 moves the follower 15 and the retaining member 6 to the left as shown in FIG. 1, or downstream, with regard to the running direction 7, and then returns it to the right or upstream. At this time, the contacting face 10 of the retaining member 6 holds the needle thread in contact with the contacting face 5 while the needle thread is passing, and then slowly returns to the contacting face 5. Therefore, the thread of the needle thread loop may be passed smoothly without the emission of noise.
FIG. 2 is a perspective view of another embodiment. In this example, which is similar to the previous embodiment, the same or similar reference numbers are employed for corresponding parts. The retaining member 6a is affixed to one end of a support shaft 25 which is held by a bearing 26. The axial line of the shaft 25 is vertical to the axial line of the drive shaft 1 (see FIG. 1). A follower 27 is affixed to the other end of the support shaft 25, and this follower 27 is abutted against an eccentric cam 16a by means of a spring 28. While the drive shaft 1 rotates two revolutions, the drive shaft 18 completes one revolution, and when the needle thread loop passes between the contacting face 5 and a contacting face 10a, the eccentric cam 16a moves the follower 27 in the direction of arrow 29. As a result, the support shaft 25 is rotated angularly. The retaining member 6a is rotated angularly in the same direction as the rotary running direction 7 of the loop taker. Therefore, the needle thread loop can smoothly pass between the contacting face 5 and contacting face 10a. After the passing of the needle thread loop, the follower 27 returns in a direction opposite to the direction of arrow 29, and the retaining member 6a returns to the original position.
FIG. 3 is a perspective view of part of another embodiment. The same or similar reference numbers are employed for corresponding parts. What is of note is that a retaining member 31 has a contacting face 10b which abuts against the contacting face 5 of the bobbin case 3. This retaining member 31 has a contacting face 32 which is concave in the downstream direction with regard to the rotary running direction 7 of the loop taker. Face 32 is joined to contacting face 10b by a curved communicating surface 38. A support shaft 33 is fixed to retaining member 31 and extends orthogonal to the axis of rotation of the loop taker (see FIG. 1). A follower 34 is fixed to support shaft 33. The follower 34 is urged by a spring 35 to abut against the cam surface of an eccentric cam 16b.
When the needle thread loop passes between the contacting face 5 and retaining member 31, the follower 34 is rotated angularly in the direction of arrow 37 by means of the eccentric cam 16b. As a result, the contacting face 5 abuts against the contacting face 32. Therefore, the needle thread loop may pass smoothly between the contacting face 5 and the contacting face 32 of the retaining member 31. After the passing of the needle thread loop, the follower 34 is rotated in a direction opposite to the direction of arrow 37, and the contacting face 5 moves from the contacting face 32, along communicating surface 38, to again abut the contacting face 10b of the retaining member, thereby returning to the original position. The communicating surface 38 smoothly connects the contacting face 10b and the contacting face 32, which permits smooth movement of the bobbin case 3 in the direction 7 and the reverse direction at the time of angular movement of the retaining member 31.
In the embodiment in FIG. 3, retaining member 31 is driven so as to be pivoted reciprocally, but it is also possible to provide another embodiment, by continously rotating a retaining member having a continuous contacting face in the peripheral direction contacting with the contacting face 5, forming the contacting plane 32 for slipping out the needle thread loop partly in the peripheral direction, and forming a contacting face 10b of the retaining member in the remaining part in the peripheral direction.
In another example, the present invention may be equally applied to horizontal full rotation shuttles or semi-rotation shuttles.
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.
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A stopper device for a lock stitch sewing machine includes a retaining member having a contacting face and which is moved in the downstream direction, with respect to the rotary running direction of the loop taker, when a needle thread loop passes between a contacting face of the bobbin case and such contacting face of the retaining member. This facilitates the passing of the needle thread loop. An arrangement returns the contacting face of the retaining member in the upstream direction.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application relates and claims priority to U.S. Provisional Patent Application, Ser. No. 61/868,228, filed Aug. 21, 2013, the entirety of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to private branch exchange systems, and more particularly to such systems that map and display the structure of private branch exchange systems.
2. Description of the Related Art
Private branch exchange systems are ubiquitous in office spaces, buildings, and corporations. These systems are often managed by a hosted PBX system. However, hosted PBX systems offer no visual aid for user to understand the structure of the private branch exchange. Rather, understanding the layout of a private branch exchange may be a difficult and tedious task. As a result, managing a private branch exchange in an office building is complex and time-consuming. Accordingly, there is a need in the art to provide a user with a simple visual representation of a private branch exchange, so the user can quickly understand the structure of a private branch exchange and easily make any necessary changes.
SUMMARY OF THE INVENTION
The present invention provides a system and method for mapping a private branch exchange. By providing a visual representation of a private branch exchange, the process for making changes to the PBX is made easier and may be done quickly and accurately.
In accordance with an embodiment of the present invention, a system for mapping a hosted private branch exchange is provided. The system generally comprises a first database in which data representative of the hosted private branch exchange is stored. A communications module permits a user to request data from this first database, and a second database stores the data that was requested from the first database. The requested data comprises data representative of, for example, phone numbers, users, auto attendants, hunt groups, call centers, and physical phones and devices. A database management module provides the functions of: parsing and storing the data requested from the first database into first and second categories, wherein the second category comprises at least five distinct categories in which objects representative of predetermined data are assigned; the function of generating call paths between said objects; the function of generating logical connections between the objects; the function of creating directional relationships between pairs of said objects; and the function of generating an interactive map. A graphical interface is further provided that is in communication with the database and adapted to provide a visual representation of said interactive map on a display, thereby permitting the user to visually see the PBX and be able to make changes to it as necessary.
Another aspect of the present invention provides a method for mapping a private branch exchange the data representative of which is stored in a first database. The method generally comprise the steps of: requesting data from the first database and storing the requested data in a computer readable second database. The data is then parsed and stored into first and second categories, wherein the second category comprises at least five distinct categories in which objects representative of predetermined data are assigned. Call paths are then generated between the objects and logical connections are also generated between the objects. Based on these connections, directional relationships between pairs of said objects are then established. An interactive map is then constructed based on the objects and their connections and relationships. A graphical interface is provided that is in communication with the second database and adapted to provide a visual representation of the interactive map on a display. A user can therefore use the graphical interface as a tool to see and edit if necessary the PBX, with any edits made being saved to the database.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
FIG. 1 illustrates a high level diagram of an embodiment of the present invention.
FIG. 2 illustrates an embodiment of the graphical user interface generated by an embodiment of the present invention.
FIG. 3 illustrates a high level diagram of an embodiment of the method of the present invention.
FIG. 4 illustrates a diagram of an embodiment of the method of the present invention.
FIG. 5 illustrates a diagram of an embodiment of the method of the present invention.
FIG. 6 illustrates a sample of data from a hosted PBX system.
FIG. 7 illustrates a sample of data converted by an embodiment of the present invention into an organized structure.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein like reference numerals refer to like parts throughout, FIG. 1 illustrates a high level diagram of an embodiment of the present invention. Referring to FIG. 3 , the embodiment of the present invention comprises a system 002 for querying and receiving data from a hosted PBX system (in the present embodiment, Broadsoft Services) and organizing the received data in a way that can be displayed to and easily modified by a customer.
As shown in FIG. 1 , system 002 is embodied as a web-based application, and generally comprises three parts: backend services 004 , a viewer 006 , and a cache 008 . Backend services 004 represents a collection of program modules/services conducted by the backend. Broadly speaking, backend services 004 queries hosted PBX system 010 (for example, for data such as all users, auto attendants, hunt groups, call centers, and devices. In the preferred embodiment, backend services 004 next parses all received data and transforms the data into an object oriented structure. In an alternative embodiment, any structure for storing information in memory known in the art may be used; memory refers to the physical devices used to store programs (sequences of instructions) or data (e.g. program state information) on a temporary or permanent basis for use in a computer or other digital electronic device. The data, now in an object oriented structure, is stored within cache 008 for quick response times, as well as to maintain a list of changes for differential comparison. The cache may consist of JSON files, XML files, a database, or any other equivalent storage unit known in the art.
As shown in FIG. 1 , system 002 may be embodied as a web-based application; however, in alternative embodiment system 002 may exist as a local application. According to the embodiment in shown in FIG. 1 , a customer, using a browser, will log in to system 002 via viewer 004 . In the present embodiment, viewer 004 is comprised of a servlet/JSP architecture. Viewer 004 may prompt the user for an ID and password. Passwords may be stored as SHA-256 hash values, or alternatively as any other cryptographic hash function or encryption known in the art. In one embodiment, once a customer has logged into system 002 , the customer will be presented with a graphic interface representing the structure of the PBX system, generated from the data stored in the cache.
FIG. 2 shows an embodiment of the present graphic interface. Although FIG. 2 depicts the interface as a tree structure, any other structure or format could be used. Displaying the structure of the private branch exchange greatly enhances the usability of a PBX system.
System 002 , its methods, and alternative embodiments of both, are described in detail below. FIG. 3 shows a high-level flow chart of an embodiment of a method of the present invention. FIG. 3 shows three broad steps: (1) initial user log on step; (2) data retrieval and storage step; (3) generate call path step.
FIG. 4 shows a flow chart of an embodiment of the login step. Once the user enters his or her ID and password, backend services 004 sends the user's credentials to hosted PBX system 010 . Hosted PBX system 010 returns access rights and permission levels to backend services 004 . Next, viewer 006 directs user's interface to display a list of available companies/phone systems for user to select from. Once the user selects a particular company/phone system, backend services 004 checks cache 006 to ascertain whether the data for that company/phone system has been cached from a prior session. If the data has not been stored from a prior session, or was not stored from a recent prior session, backend services 004 may automatically refresh the data. If the data has been stored from a recent prior session, viewer 004 will display the most recent cached version of the data; however, the user will be given the option to refresh the data if he or she chooses.
If the user elects to refresh or a refresh is required, backend services 004 begins the process of obtaining current data from hosted PBX system 010 . First, a list of data is requested from hosted PBX system 010 , which typically includes phones numbers, users, auto attendants, hunt groups, call centers, and physical phones and devices. Next a database framework is created for storing the data received from hosted PBX systems 010 . Once the data is received and parsed from hosted PBX systems 010 , backend services 004 stores the data into one of two categories: All Numbers Map and All Objects Map. All Numbers Map stores all number data received from hosted PBX system 010 . All Objects Map is comprised of at least five distinct categories: (1) users, (2) auto attendants, (3) hunt groups, (4) call centers, and (5) devices. All data stored in the All Objects Map is put within its respective category. Next, for each object stored in the database, backend services 004 iteratively requests profile information, assigned services list, and assigned services detail. These requests continue until all data from hosted PBX system 010 is retrieved for every object and stored in the database.
FIG. 5 illustrates a flowchart of an embodiment of the next broad sequence of steps for generating call paths between the objects stored in the prior step. First, all phone numbers must be stored in the database with consistent formatting. Hosted PBX systems often store phone numbers in a variety of formats—numbers can be stored with or without dashes, area codes, etc. Often hosted PBX systems will even store feature access codes, such as *69, with the numbers. In order to be used in a system that enables call flow, numbers must first be identified and then normalized to fit a specific format structure. To accomplish this, backend services 004 first looks up the list of feature access codes. Next, the database is searched for phone number fields, and all found fields are stored in a “Referenced Phone Number List.” The feature access codes are then searched for and removed from the “Reference Phone Number List,” leaving only the numbers. Finally, the remaining numbers are then given a consistent formatting scheme by removing any “+1,” hyphens, parenthesis, etc. For example, backend services 004 first looks up a list of feature access codes, and finds one to be *55. Next, “Reference Phone Number List” is cross-referenced for the feature access code *55. If an option on the main auto attendant is *556315551212, the number is stripped of *55, reformatted simply as 6315551212 and stored again in “Reference Phone Number List”.
Once the data is formatted consistently, backend services 004 must generate connections between the objects stored in the database. For example, if auto attendant is automatically directing all phone calls to the voicemail of a device within the network, a connection will need to be made between the auto attendant and the device that the auto attendant is directing calls to. The first step of this process is to search each object stored in the database for each number stored in the “Reference Phone Number List.” Each object that contains a particular number in the “Reference Phone Number List” is grouped, together with that number, in the “Matched Number List.” In conducting its search, backend services 004 first searches for the extension, then the full number, and finally the partial number. For example, first the database is searched for each number in the “Reference Phone Number List” beginning with 6315551212. Next, once a device having the assigned number of 6315551212 is found, and an auto attendant is found with an option of 6315551212, both are added with the number to “Matched Number List.”
Once the “Matched Number List” is created, backend services 004 uses “Matched Number List” to search the database for each object that contains a number belonging to another object and creates a directional relationship between the two. For example, if an object is found with assigned number or extension matching 6315551212, and an auto attendant with the option *556315551212 is also found, a directional relationship is created between the two. Next, backend services 004 follows all paths for each object assigned with a number. Backend services 004 starts with the first object that has an assigned phone number and then, using the “Referenced Phone Number List,” follows the outbound call paths from the object until it reaches the end of the call path or a circular reference. Backend services 004 repeats this process for each top level object. Finally, using the previous steps, a list of nodes and edges are generated. Nodes represent individual objects and edges represent where two objects connect. In the preferred embodiment, the list of nodes and edges are the final format used to generate an interactive format (in the present embodiment, a mindmap) that can be easily understood and altered.
In the preferred embodiment, during the broad step of generating call paths, an output as GoJS readable JSON file is generated and used for the front end visual interface to display the interactive format. Every time data is retrieved or a connection is made, it is stored in a format readable by GoJS. In an alternative embodiment, the data is stored in XML files or mapped into a database. In an alternative embodiment, all data is stored in a separate step, after the call paths have been generated.
Although the present invention has been described in connection with a preferred embodiment, it should be understood that modifications, alterations, and additions can be made to the invention without departing from the scope of the invention as defined by the claims.
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A system and method for mapping a private branch exchange is provided whereby a visual representation of a private branch exchange is graphically displayed. Once the PBX is mapped, a user can then make changes to the connections and other data in the branch exchange and save those changes such that the PBX will then follow the edited structure.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is entitled to the benefit of, and claims priority to, provisional U.S. Patent Application Ser. No. 60/492,063 filed Aug. 1, 2003 and entitled “SUSCEPTOR FOR SUPPORTING WAFERS DURING SEMICONDUCTOR MANUFACTURE,” the entirety of which is incorporated herein by reference.
BACKGROUND OF THE PRESENT INVENTION
[0002] 1. Field of the Present Invention
[0003] The present invention relates generally to the manufacture of substrate wafers of the type used in producing semiconductor devices, and, in particular, to susceptors and other substrate wafer holders for use in a substrate supporting mechanism in a reaction chamber during semiconductor manufacturing processes.
[0004] 2. Background
[0005] Typical wafer holders are described in U.S. Pat. Nos. 4,821,674 and 5,427,620. These wafer holders are typically used to support a single substrate wafer during various wafer processes during the manufacture of integrated circuits. Such process applications may include silicon application processes such as chemical vapor deposition (“CVD”) and physical vapor deposition (“PVD”), thermal process applications used for treatment of semiconductor wafer substrates such as rapid thermal processing (“RTP”) and high temperature etch processing, and the like.
[0006] To save process time, substrate wafers must be loaded at an elevated temperature, and when the wafers are placed on a flat, smooth, unbroken surface, the heat-related convection currents affect the ability of the substrate wafer to settle uniformly. Thus, as shown in the aforementioned patents, a series of intersecting channels is typically machined or otherwise applied to the wafer contact surface of the holder, the intent of which is to provide a free flow of gases between the substrate and holder to avoid undesired movement of the substrate during loading and unloading operations. The presence of the intersecting channels alleviates the substrate settling issue by allowing the hot gases to escape from underneath the wafer. The intersecting channels also facilitate loading the wafers using the Bernoulli principle.
[0007] The above cited patents depict a wafer holder with only a limited number of intersecting channels. However, in practice, the number of channels required is very large because of the need to maintain a uniform temperature profile over the surface of the substrate wafer which the holder supports. In addition, it is difficult to maintain the uniformity of the channeled surface, which is critical to avoiding issues such as image transfer to the process wafer. Both temperature uniformity and image transfer issues must be avoided to ensure proper electrical and physical properties of the process wafer along with any deposited coatings.
[0008] U.S. Pat. No. 5,403,401 cites a number of manufacturing issues involving wafer holders made with a substrate contact face possessing a series of underlying, intersecting channels, a typical example of which is shown in FIGS. 1A-1C . Specifically, wafer holders of this design are difficult to maintain flat during manufacture if the channels exist only on one face of the holder. After machining, these wafer holders, which are typically machined from graphite, receive a coating, such as silicon carbide (SiC), deposited by CVD at high temperatures. As the holder cools to room temperature, differential shrinkage between the holder substrate and the coating generally leads to a state of stress, wherein the coating is under compression and the substrate under tension (although this stress state may be reversed, depending upon the properties of the substrate and the coating). The amount of stress that develops is dependent in part upon the surface area. As a result, large surface area differences between the two faces of the same holder, such as those that may exist when only one face is machined, can lead to large differences in stress, which in turn cause the part to distort or warp.
[0009] To alleviate this problem, the above-cited patent suggests that similar machining detail should be added to both faces of the wafer holder in order to avoid the differences in stress and thus ensure that the part remains flat after coating. Unfortunately, adding machining detail to both sides of the wafer holder can significantly increase its manufacturing cost. Another solution cited in the above patent is to tailor the thickness of the coating so that a controlled coating differential is maintained between the two opposite faces. In principle, this is an appropriate fix; however, in practice it can be difficult to maintain a consistent coating thickness differential between faces. There is also the problem that the amount of thickness differential required is a function of the differential in coefficient of thermal expansion (“CTE”) between the holder substrate and the surface coating. Unfortunately, certain holder substrate materials, such as graphite, have CTE's which span a range, which complicates this process. For example, the range for graphite is affected by the type of coke used in its manufacture, binder levels, particle sizing, and processing temperatures.
[0010] There is also a need to minimize the total contact area between the wafer holder and substrate wafer in order to maintain a uniform temperature profile across the surface of the wafer as well as to minimize any markings to the backside of the substrate wafer. In order to minimize total contact area, the number of channels is intentionally high, which means that the grids formed at the channel intersections are kept small. It is the tops of these individual grid areas, formed by the channels, that provide support for the wafer substrate. The problem with small grids is that they are relatively weak areas of the holder surface, and thus are prone to damage. This in turn can affect the lifetime of the wafer holder if one or more grids become damaged.
[0011] One additional drawback of wafer holders having a high number of intersecting channels on one or more faces is that such wafer holders are more prone to developing pinholes in the surface coating. This will also cause the wafer holder to be rejected, since once the coating is breached, the substrate beneath the coating is exposed to the process environment. The higher occurrence of pinholes through the surface coating on parts machined with a high number of channels is due to coating thickness variations along with cleaning issues, which are more problematic at the base of the machining detail. (Pinhole formation occurs over a period of time during use of the holder. This is generally a surface erosion problem, which can be affected by cleanliness.)
[0012] One final drawback to wafer holders machined with a high number of intersecting channels is that it is often desired to machine a concave-shaped profile into the face of the holder that is in contact with the substrate wafer, particularly for large diameter wafers and/or lower temperature processes which require a higher level of temperature uniformity. The presence of a high amount of surface detail greatly increases the complexity of machining such a profile, which further adds to the cost of the part.
SUMMARY OF THE PRESENT INVENTION
[0013] The wafer holder described in the present invention has a number of advantages over present state-of-the-art wafer holders. For example, it requires a smaller amount of machining and requires less complex machining, making it easier to incorporate concave surface profiles, especially for large substrate wafer diameters. This, in turn, provides improved part-to-part consistency. It is also more damage tolerant, making it easier to maintain dimensional control during manufacture, and provides improved wafer holder performance.
[0014] Broadly defined, the present invention according to one aspect is a wafer holder for holding semiconductor substrate wafers in a chemical vapor deposition system, including: a holder body having a top surface; a circular wafer recess in the top surface of the holder body, the wafer recess having an outer perimeter and an interior area; and a plurality of slots arranged in the top surface of the holder body, each beginning adjacent the outer perimeter of the wafer recess and extending toward and terminating in the interior area of the wafer recess.
[0015] In features of this aspect, the wafer holder further includes a circular groove extending around the outer perimeter of the wafer recess; substantially all of the slots extend radially from the circular groove toward the interior area of the wafer recess; the holder body is formed from at least one of the following: graphite, silicon, silicon nitride, silicon carbide, quartz or aluminum oxide; a surface coating may be applied to at least the top surface of the holder body; the surface coating is formed from at least one of the following: silicon carbide, silicon nitride, pyrolytic graphite, pyrolytic carbon, diamond, aluminum nitride, aluminum oxide, silicon dioxide or tantalum carbide; the wafer recess may encompass a concave surface; the concave surface of the wafer recess is adapted to aid in gas flow beneath a substrate wafer disposed in the wafer recess; the concave surface of the wafer recess is adapted to help maintain a uniform temperature profile across the surface of a substrate wafer disposed in the wafer recess; the number of slots is selected to minimize negative effects on the thermal profile of a substrate wafer disposed in the wafer recess; and the number of slots is selected to allow sufficient gas flow beneath the substrate wafer to aid in proper loading and unloading operations.
[0016] In other features of this aspect, the dimensions of the slots are selected to minimize negative effects on the thermal profile or backside markings of a substrate wafer disposed in the wafer recess; the dimensions of the slots are selected to provide effective gas flow beneath substrate wafers for the purpose of aiding in proper loading and unloading operations; each of the plurality of slots is between 0.030 in. and 1.000 in. in length, and preferably between 0.035 in. and 0.065 in. in length; each of the plurality of slots is between 0.010 in. and 0.030 in. in width, and preferably between 0.015 in. and 0.025 in. in width; and each of the plurality of slots is at least 0.001 in. deep, and preferably between 0.004 in. and 0.008 in. deep.
[0017] In other features of this aspect, the wafer holder is a susceptor; the wafer holder further includes a circumferential ledge for supporting the edges of a wafer; the plurality of slots are disposed at least partly in the circumferential ledge; and the wafer recess. is a first wafer recess, the plurality of slots is a first plurality of slots, and the wafer holder further includes a second circular wafer recess in the top surface of the holder body adjacent the first circular wafer recess, the wafer recess having an outer perimeter and an interior area, and a second plurality of slots arranged in the top surface of the holder body, each beginning adjacent the outer perimeter of the second wafer recess and extending toward and terminating in the interior area of the second wafer recess.
[0018] The present invention according to another aspect is a wafer holder for holding semiconductor substrate wafers in a chemical vapor deposition system, including: a holder body having a top surface; a circular wafer recess in the top surface of the holder body, the wafer recess having an outer perimeter and an interior area; and a plurality of non-interesting slots arranged in the top surface of the holder body, each beginning adjacent the outer perimeter of the wafer recess and extending toward and terminating in the interior area of the wafer recess.
[0019] In features of this aspect, the wafer holder further includes a circular groove extending around the outer perimeter of the wafer recess; substantially all of the slots extend radially from the circular groove toward the interior area of the wafer recess; the holder body is formed from at least one of the following: silicon, silicon nitride, silicon carbide, quartz or aluminum oxide; a surface coating may be applied to at least the top surface of the holder body; the surface coating is formed from at least one of the following: silicon carbide, silicon nitride, pyrolytic graphite, pyrolytic carbon, diamond, aluminum nitride, aluminum oxide, silicon dioxide or tantalum carbide; the wafer recess may encompass a concave surface; the concave surface of the wafer recess is adapted to aid in gas flow beneath a substrate wafer disposed in the wafer recess; the concave surface of the wafer recess is adapted to help maintain a uniform temperature profile across the surface of a substrate wafer disposed in the wafer recess; the number of slots is selected to minimize negative effects on the thermal profile of a substrate wafer disposed in the wafer recess; and the number of slots is selected to allow sufficient gas flow beneath the substrate wafer to aid in proper loading and unloading operations.
[0020] In other features of this aspect, the dimensions of the slots are selected to minimize negative effects on the thermal profile or backside markings of a substrate wafer disposed in the wafer recess; the dimensions of the slots are selected to provide effective gas flow beneath substrate wafers for the purpose of aiding in proper loading and unloading operations; each of the plurality of slots is between 0.030 in. and 1.000 in. in length, and preferably between 0.035 in. and 0.065 in. in length; and each of the plurality of slots is between 0.010 in. and 0.030 in. in width, and preferably between 0.015 in. and 0.025 in. in width; and each of the plurality of slots is at least 0.001 in. deep, and preferably between 0.004 in. and 0.008 in. deep.
[0021] In other features of this aspect, the wafer holder is a susceptor; the wafer holder further includes a circumferential ledge for supporting the edges of a wafer; the plurality of slots are disposed at least partly in the circumferential ledge; and the wafer recess is a first wafer recess, the plurality of slots is a first plurality of slots, and the wafer holder further includes a second circular wafer recess in the top surface of the holder body adjacent the first circular wafer recess, the wafer recess having an outer perimeter and an interior area, and a second plurality of slots arranged in the top surface of the holder body, each beginning adjacent the outer perimeter of the second wafer recess and extending toward and terminating in the interior area of the second wafer recess.
[0022] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Further features, embodiments, and advantages of the present invention will become apparent from the following detailed description with reference to the drawings, wherein:
[0024] FIG. 1A is a top view of a typical prior art wafer holder;
[0025] FIG. 1B is a side cross-sectional view of the prior art wafer holder of FIG. 1A , taken along line 1 B- 1 B;
[0026] FIG. 1C is a side cross-sectional view of the prior art wafer holder of FIG. 1B , shown with a wafer positioned thereon;
[0027] FIG. 2 is a block diagram of a conventional chemical vapor deposition system;
[0028] FIG. 3 is a perspective view of the wafer holder of FIG. 2 , shown in isolation, in accordance with the preferred embodiments of the present invention;
[0029] FIG. 4A is a top view of the wafer holder of FIG. 3 ;
[0030] FIG. 4B is a partial side cross-sectional view of the wafer holder of FIG. 4A , taken along line 4 B- 4 B;
[0031] FIG. 4C is a partial side cross-sectional view of the wafer holder of FIG. 4B , shown with a wafer positioned thereon;
[0032] FIG. 5 is a top view of a multiplexed wafer holder, where two wafer recesses are arranged side by side in a single holder body, in accordance with an alternative embodiment of the present invention;
[0033] FIG. 6A is a perspective view of a prior art stepped-type wafer holder; and
[0034] FIG. 6B is a partial side cross-sectional view of the wafer holder of FIG. 6A , taken along line 6 B- 6 B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Referring now to the drawings, in which like numerals represent like components throughout the several views, the preferred embodiments of the present invention are next described. The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0036] The preferred embodiments of the present invention will be described with reference to an otherwise-conventional chemical vapor deposition (“CVD”) system 10 , because CVD is an example of a typical process for which the wafer holder of the present invention may find application. However, it should be understood that the wafer holder of the present invention may be used in a wide variety of wafer processes, including physical vapor deposition (“PVD”), rapid thermal processing (“RTP”), high temperature etch processing, and other thermal processing, and generally including any other process in which a semiconductor wafer must be lifted from a generally flat surface.
[0037] FIG. 2 is a block diagram of a conventional chemical vapor deposition (“CVD”) system 10 . The CVD system 10 includes a reaction chamber 12 and a support mechanism 14 . The reaction chamber 12 may be of any conventional design, including the type sometimes referred to as a horizontal flow reaction chamber such as that disclosed in U.S. Pat. No. 5,427,620, the entirety of which is incorporated herein by reference.
[0038] The support mechanism 14 is preferably rotatable and may be likewise generally similar to that disclosed in the '620 patent. Of particular relevance, the support mechanism 14 includes a wafer holder 16 disposed within the reaction chamber 12 . The wafer holder 16 may be of a type often referred to as a susceptor, which typically is heated inductively, or of other types known to those skilled in the art.
[0039] FIG. 3 is a perspective view of the wafer holder 16 of FIG. 2 , shown in isolation, in accordance with the preferred embodiments of the present invention. As illustrated therein, the wafer holder 16 primarily includes a solid body 18 in the general shape of a flattened cylinder. The body 18 may be formed from any conventional wafer holder body material, most commonly including pure graphite but alternatively composed of silicon, silicon nitride, silicon carbide, quartz, aluminum oxide or another ceramic material or metal or metal alloy. The selection of material conventionally depends on the end-user's process requirements.
[0040] FIG. 4A is a top view of the wafer holder 16 of FIG. 3 , and FIG. 4B is a partial side cross-sectional view of the wafer holder 16 of FIG. 4A , taken along line 4 B- 4 B. Of particular interest, and as perhaps best understood with reference to FIGS. 4A and 4B , the holder body 18 includes a top surface 20 and a bottom surface 22 . Centered on the top surface 20 is a wafer recess 24 formed by a slight depression in the holder body 18 , explained below, and defined by an outer circumferential rim 26 . At the perimeter of the recess 24 , immediately inside the outer rim 26 , is arranged a continuous circular groove 28 . The wafer recess 24 is adapted to support a wafer 30 therein, and the size of the wafer recess 24 , and thus the location of the circular groove 28 , is selected in conjunction with the selection of the size of the wafer 30 . FIG. 4C is a partial side cross-sectional view of the wafer holder 16 of FIG. 4B , shown with a wafer 30 positioned thereon. As shown, the wafer 30 fits comfortably within the wafer recess 24 , with the outer edge of the wafer 30 preferably positioned directly above the circular groove 28 .
[0041] Though not strictly necessary, the circular groove 28 helps ensure uniform gas flow under the wafer 30 during processing. By increasing the size of the groove 28 , the gas flow may be more easily controlled; however, temperature uniformity issues dictate against enlarging the groove too much. The size of the groove 28 is thus generally controlled by conventional principles, and the selection of an appropriately-sized groove may be dependent on the manufacturing process in which the wafer holder 16 is to be used. However, it is known that grooves 28 having a semicircular profile that is 0.035 in. wide and 0.035 in. deep have been used successfully as described herein below.
[0042] The top surface 20 further includes a ring of narrow, non-intersecting slots 32 which extend inward from the groove 28 a fixed distance toward the center of the wafer recess 24 . The slots 32 are preferably radial in orientation, such that each slot 32 extends directly toward the geometric center of the wafer recess 24 , but it will be apparent that the orientation or angle of the slots 32 may vary considerably while still providing a path between the circular groove 28 and the interior area of the wafer recess 24 , and that such arrangements are within the scope of the present invention. The depth of each slot is preferably at least 0.001 in., and preferably in the range of 0.004-0.008 in., though other depths may be feasible. The fixed length of the slots 32 , along with their width and number, are dependent on the diameter and thickness of the wafer 30 in order to effectively lift the wafer 30 during loading and unloading utilizing the Bernoulli principle.
[0043] It is important that the distance that the radial slots 32 extend underneath the wafer 30 (referred to herein as the amount of “slot overlap” with the substrate wafer 30 ) encompass both CTE-related growth and the possible off-center loading of the substrate wafer 30 in the substrate wafer recess 24 . The amount of slot overlap must also be controlled so as not to be so great that it affects temperature uniformity of the substrate wafer 30 or contributes to backside markings on the substrate wafer 30 . It is known that extending the slots 32 all the way to the actual center of the interior area of the wafer recess 24 is problematic. However, it is further believed that successful results may be achieved with slots 32 of an inch in length, at least with wafer holders 16 designed to accommodate 6-in. diameter wafers 30 . On the other hand, the overlap must be of a minimum length so as to provide sufficient gas flow to facilitate substrate wafer loading and unloading operations using Bernoulli principle. Although neither the minimum or maximum lengths are known, it is known that slots 32 of 0.040-0.060 in. have been used successfully as described herein below.
[0044] It is also important to control the number of slots 32 in that, based on a given slot area, a minimum number of slots 32 is required in order to properly engage a substrate wafer 30 during loading and unloading operations. The minimum number is primarily dependent on the surface area of the slots 32 relative to the surface area of the wafer recess 24 , since this results in a corresponding lift force. Thus, the number of slots 32 may depend on the width and length of the slots 32 used, as well as the size of the wafer recess 24 . Wide slots 32 , however, are to be avoided as they will lead to localized thermal effects, and the length of the slots 32 should be controlled as described previously. Exact limits on the number of slots 32 and their width are unknown, but it is known that 96 slots 32 , each 0.019 in. wide, have been used successfully in wafer holders 16 designed to accommodate 6-in. diameter wafers 30 as described herein below.
[0045] It is also believed that the slots 32 must be arranged in a generally uniform pattern around the perimeter of the wafer recess 24 in order to maintain temperature uniformity and the like. Thus, the spacing between slots 32 is preferably constant around the entire perimeter, and the length, width and depth of each slot 32 is preferably constant. However, it may be possible to use uniform patterns of slots 32 having a uniformly-varying pattern of lengths, widths, or spacings without departing from the scope of the present invention.
[0046] The bottom surface 22 of the holder body 18 is of conventional design. A circular support groove 34 may be disposed in the bottom surface 22 such that the wafer holder 16 may be placed or mounted on an appropriate structure in the support mechanism 14 , such as the spider-type pedestal, typically composed of quartz, shown in U.S. Pat. No. 5,427,620.
[0047] The holder body 18 may or may not be covered with a surface coating 36 composed of one of the following: silicon carbide, silicon nitride, pyrolytic graphite, pyrolytic carbon, diamond, aluminum nitride, aluminum oxide, silicon, silicon dioxide or tantalum carbide. Conventionally, the coating 36 is applied to the entire substrate, including but not limited to the top and bottom surfaces 20 , 22 .
[0048] The slight depression forming the wafer recess 24 may have a slightly concave profile, perhaps best seen in FIG. 4C , that may be created by machining the top surface 20 of the holder body 18 . The depression further aids in releasing the substrate wafer 30 from the holder 16 by allowing gases to flow freely beneath the wafer 30 and preventing the wafer 30 from sticking to an otherwise flat surface. Concave surface profiles are desired for improved wafer temperature uniformity due to the tendency of wafers 30 to sag at high temperatures. The deformity caused by the sag will be a function of substrate wafer diameter as well as the end-user's process conditions. Moreover, because temperature uniformity may be optimized when the gap between the sagging wafer 30 and the top surface of the holder body 18 is relatively uniform, the profile of the wafer recess 24 preferably matches or approximates that of the sagging wafer 30 . Thus, because the profile of a wafer 30 when sagging is assumed to be roughly spherical, the concavity of the wafer recess 24 may be spherical as well. However, it will be apparent that closer analysis of the profile of a wafer 30 when sagging will likely reveal non-spherical characteristics, and thus the profile of the wafer recess 24 may be varied accordingly.
[0049] In general, larger diameter wafers 30 and lower end-use process temperature conditions favor the use of profiles that have a larger dished shape. Reasons for this include the fact that larger wafers 30 are heavier so the need to minimize adhesion between the wafer 30 and the mating face of the substrate holder 16 is more critical. In addition, larger wafers 30 will sag more at temperature than smaller wafers 30 , so a larger dished profile may help achieve improved temperature uniformity. The concavity of conventional wafer recesses used in wafer processing may range from 0.002 in. to 0.010 in., with greater concavity required for particularly sensitive processing.
[0050] Six susceptor-type wafer holders designed and manufactured according to the principles described herein were tested under standard process conditions. The wafer holder included a wafer recess sized to accommodate wafers having a diameter of 6 in. Each wafer holder included 96 radial slots, each 0.007 in. deep and 0.019 in. wide and 0.040 in. long. The wafer recess of each wafer holder was 0.017 in. deep and concave in profile by 0.002 in., and the continuous groove of each wafer holder was 0.035 in. wide and 0.035 in. deep. The six test parts worked successfully (successful release of a semiconductor wafer from the wafer holder using Bernoulli principle-based pickup) in up to 10,000 runs, which compares very favorably to the typical lifetime experienced in the industry, for conventional wafer holders such as the one illustrated in FIGS. 1A-1C , of approximately 2,000 to 4,000 runs.
[0051] In view of such success, a susceptor-type wafer holder designed and manufactured according to the principles described herein was used in a silicon epitaxy deposition process. The wafer holder included a wafer recess sized to accommodate wafers having a diameter of 6 in. The wafer holder included 96 radial slots, each 0.060 in. long, 0.005 in. deep and 0.019 in. wide. The wafer recess was 0.017 in. deep and concave in profile by 0.0025 in. The continuous groove was 0.035 in. wide and 0.035 in. deep. The wafer holder was used successfully in 178 runs before use was discontinued for an unrelated issue. General performance was equal to that of conventional wafer holders such as the wafer holder illustrated in FIGS. 1A-1C , but significantly, all wafer coatings carried out using the test wafer holder were of high quality with no indication of the temperature uniformity problems or image transfer issues described previously.
[0052] Alternative configurations of the wafer holder of the present invention will be apparent to those of ordinary skill in the art. For example, FIG. 5 is a top view of a multiplexed wafer holder 66 , where two wafer recesses 74 are arranged side by side in a single holder body 68 , in accordance with an alternative embodiment of the present invention. Each wafer recess 74 includes a circular groove 78 and a plurality of slots 82 , similar to the groove 28 and slots 32 provided in the wafer holder 24 previously described. Other than the inclusion of a second wafer recess 74 and the second plurality of slots 82 , the wafer holder 66 of FIG. 5 is generally similar to the first wafer holder 16 .
[0053] Such a configuration may be useful in maximizing the number of wafers 30 produced in a particular reaction chamber 12 . For example, a particular reaction chamber 12 may be designed to accommodate the manufacture of 8-in. wafers 30 , but a manufacturer sometimes wishes to use the reaction chamber 12 in the manufacture of wafers 30 that are only 4 in. in diameter. Manufacture of either wafer size may be accomplished through the use of an appropriately-sized wafer holder 16 of the type described herein. However, the manufacture of 4-in. wafers 30 in the 8-in. reaction chamber 12 may be optimized by using a wafer holder 66 such as the one shown schematically in FIG. 5 . This approach may further be utilized to design wafer holders (not shown) having other numbers, sizes and arrangements of wafer recesses as will be readily apparent to those of ordinary skill in the art.
[0054] The teachings of the present invention may be applied to other types of wafer holders as well. For example, FIG. 6A is a perspective view of a prior art stepped-type wafer holder 116 , and FIG. 6B is a partial side cross-sectional view of the wafer holder 116 of FIG. 6A , taken along line 6 B- 6 B. The stepped-type wafer holder 116 includes a circumferential ledge 119 around the perimeter of a wafer recess 124 for supporting the outer edges of a wafer 30 . During processing, the wafer 30 conventionally sags into the wafer recess 124 in similar manner to that of the wafer holder 16 of the present invention. Typically, stepped-type wafer holders 116 use lift pins, disposed underneath the wafer 30 and arranged to project through openings 125 in the wafer recess 124 , to raise the wafer 30 off the top of the holder 116 from underneath, rather than using a Bernoulli-type pickup to raise the wafer 30 from above. Although not specifically illustrated, the principles of the present invention may likewise be applied to stepped-type wafer holders 116 by applying slots (not shown) to the ledge 119 . This would permit a stepped-type wafer holder 116 to use a conventional Bernoulli-type pickup during unloading operations.
[0055] Based on the foregoing information, it is readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those specifically described herein, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing descriptions thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for the purpose of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended to be construed to limit the present invention or otherwise exclude any such other embodiments, adaptations, variations, modifications or equivalent arrangements; the present invention being limited only by the claims appended hereto and the equivalents thereof. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for the purpose of limitation.
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An improved wafer holder design is described which has manufacturing and performance advantages over present state-of-the-art holders used in various wafer processing applications. The new wafer holder design incorporates a series of short radial grooves. The grooves extend from the base of a circular channel, which runs along the outside diameter of the substrate wafer recess, to a fixed radial location which varies based on wafer size and thickness. The grooves provide a slight overlap with the wafer to facilitate the free exchange of gases beneath the wafer necessary for wafer loading and unloading operations. The short length of the radial grooves make the wafer holder easier to manufacture and offer more robust performance compared to the present state-of-the-art holders.
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FIELD OF THE INVENTION
[0001] The present invention relates to the connection of an application to a resource manager selected from a plurality of resource managers.
BACKGROUND OF THE INVENTION
[0002] A bus may contain many resource managers that are inter-connected such that every resource manager in the bus has at least one route to every other resource manager in the bus.
[0003] For ease, the following explanation will be given in terms of messaging engines and a messaging bus. It should however be appreciated that the invention is not limited to such.
[0004] A messaging engine typically permits an application to retrieve information from a destination (e.g. via get message request from queue x), to request processing of some work (e.g. a put message request to queue y, requesting the update of a database) and to connect to another messaging engine via the bus in order to access a destination (e.g. queue) owned by such a messaging engine. The bus provides location transparency, enabling an application connected to one engine in the bus to reach any part of the bus via that engine. See for example, http://www.sonicsoftware.com/news_events/docs/the451 — 022304.pdf
[0005] An application may use a set of properties to control how they wish to be connected to a resource manager. These properties can contain such information as the name of the bus and the type of protocol to use. With no other constraints, in principle, an application may be connected to any messaging engine. However, while this will work functionally, connecting to an arbitrary engine may be undesirable in some situations. A performance critical application may need to connect to a particular engine—for example one that is “close” (proximate) to the application in terms of network delay.
[0006] During the Atlanta Olympics, a load balancing technique was used for managing access to the official Olympics website. When a client browser visited the website for the first time, a server hosting the site would send details of the client's IP address to each server via which access to the site could be gained. Each server would then ping the client and use this to record which server was the closest (in terms of network delay) to the client. Future attempts to access the Olympics site by the same client would then be redirected to the closest server. This is described in the article “Atlanta Olympics WOMplex” by Andy Stanford-Clark in AIXexpert Magazine, March 1997. The contents of this article was also presented at “Get Connected Technical Interchange '96 at IBM Hursley in October 1996. This process is however transparent to the client.
[0007] Other systems are known, whereby an application is connected to a server chosen by for example an IP sprayer (see http://64.233.167.104/search?q=cache:SURFepov5M0J:content.websitegear.com/article/load_balance_types.htm+%22IP+Sprayer%22&hl=en). The choice may be a random one or may be based on a factor such as load. Load Balancers are well-known—e.g. Network Dispatcher from IBM. Once again however, all of the above is transparent to the client.
SUMMARY OF THE INVENTION
[0008] According to a first aspect, the invention provides a method for determining which resource manager of a plurality of resource managers an application may be connected to, given a connection request, the method comprising: receiving a connection request specifying a connection scope, the connection scope specifying the desired proximity of a suitable resource manager relative to the application's location; determining the application's location; determining which resource managers satisfy the received connection request; and informing the connection requester of at least one resource manager that satisfies the received connection request.
[0009] In one embodiment connection scope is specified in terms of a maximum acceptable network delay. For example a user could specify an acceptable maximum network delay of 5 seconds. Statistics could be maintained and used to determine which resources are capable of meeting such a requirement. Such statistics could be gathered by resources sending out data packets such that network throughput can be measured.
[0010] Alternatively an application might specify that the selected resource manager should be located, relative to the application itself, in one of: the same host, same node, same application server, same process, same cluster, same bus. Naturally the second option is an implicit specification of acceptable network delay. For example, a resource manager in the same process as the application will have no network delay as compared with a resource manager in the same cluster or host.
[0011] Other criteria could also be used as indicative of proximity—e.g. response time, number of network hops etc.
[0012] The invention preferably provides a way of controlling network traffic. The closer a resource manager is to a requesting application, the less traffic routed through the network to get to that resource manager.
[0013] Note, an application's location may be information that is transmitted with the connection request but this does not have to be the case. Instead, an application's location may be configured information which is accessed remotely. Other variations are possible.
[0014] The step of determining which resource managers satisfy the connection request, may involve receiving such information from another entity.
[0015] In one embodiment, the selection of a resource manager comprises determining that at least two connections points satisfy the connection request and selecting a resource manager from the at least two.
[0016] Determining which of the resource managers to select may be based on the resource manager having the greatest proximity to the application (e.g. in terms of network delay etc.).
[0017] In one embodiment, information is maintained about the location of resource managers and this is used to determine which resource managers satisfy the connection request. This information may be maintained by a separate entity to the original receiver of the connection request from the application. This receiver may forward the request onto the separate entity and that entity may either select a resource manager or provide a list of possible resource managers to the receiver for selection of one thereat. In order for the receiver to make an informed choice when provided with a selection of possible resource managers, the separate entity preferably provides resource manager location information to the receiver. Alternatively, the choice may be a random one or one based on user configured preferences (these may specify a priority order of choice).
[0018] According to a second aspect, the invention provides an apparatus for determining which resource manager of a plurality of resource managers an application may be connected to, given a connection request, the apparatus comprising: means for receiving a connection request specifying a connection scope, the connection scope specifying the desired proximity of a suitable resource manager relative to the application's location; means for determining the application's location; means for determining which resource managers satisfy the received connection request; and means for informing the connection requester of at least one resource manager that satisfies the received connection request.
[0019] According to a third aspect, the invention provides a method for an application to indicate what constitutes a suitable resource manager for the application to connect to when a plurality of resource managers are available, the method comprising: specifying a connection request having a connection scope, the connection scope specifying a location of a suitable resource manager relative to the application's location; and receiving information about at least one resource manager, the at least one resource manager satisfying the connection scope specified in the connection request.
[0020] According to a fourth aspect, the invention provides an apparatus for an application to indicate what constitutes a suitable resource manager for the application to connect to when a plurality of resource managers are available, the apparatus comprising: means for specifying a connection request having a connection scope, the connection scope specifying a location of a suitable resource manager relative to the application's location; and means for receiving information about at least one resource manager, the at least one resource manager satisfying the connection scope specified in the connection request.
[0021] Preferably the resource manager returned to the receiving step/receiving means is connected to.
[0022] In one embodiment, a plurality of resource managers satisfy the connection request. Information is received about one of the plurality of resource managers where the use of that resource manager is specified as mandatory.
[0023] It will be appreciated that the present invention may be implemented in computer software.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] A preferred embodiment of the present invention will now be described, by way of example only, and with reference to the following drawings:
[0025] FIG. 1 is a component diagram of the environment in which the present invention can operate in accordance with a preferred embodiment;
[0026] FIG. 2 illustrates the detail of the workload manager (WLM) of FIG. 1 in accordance with a preferred embodiment of the present invention;
[0027] FIG. 3 illustrates the detail of the Topology Routing Manager (TRM) of FIG. 1 , in accordance with a preferred embodiment of the present invention;
[0028] FIG. 4 illustrates the processing of the TRM in accordance with a preferred embodiment of the present invention; and
[0029] FIG. 5 shows the processing of the WLM in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0030] Below is provided a glossary of the terms used throughout the specification. Such a glossary is not intended to be limiting on the present application but is provided to aid explanation:
[0000] Glossary
[0000]
Host: Computer
Node: “Virtual Host”—A host may be partitioned into one or more nodes, each with their own identity
Process: A context within an operating system having its own address space. Each process runs within a node and one or more processes typically collaborate to provide an application. For example, one process may display a GUI, whilst another may print a file.
Application: One or more processes working together to provide some functionality—e.g. email capability.
Application Server: The means by which an application may be executed.
Cluster: A group of application servers with some commonality. For example, an organising function (e.g. finance); or for the purpose of availability.
Bus: The means by which a set of resource managers may be connected together for the purpose of communicating with one another.
Messaging Engine (ME) The means by which each application server connects to a bus and achieves the processing of work/retrieval of information.
[0039] The present invention operates, in accordance with a preferred embodiment, in the environment shown in FIG. 1 . A system 5 is shown having a plurality of hosts 10 , 20 . A host may accommodate one or more individually addressable nodes. Host 10 , for example has two nodes 10 . 1 , 10 . 2 , whilst host 20 has two nodes 20 . 1 , 20 . 2 . Each node has at least one application server 10 . 1 . 1 , 10 . 1 . 2 , 10 . 2 . 1 , 20 . 1 . 1 , 20 . 1 . 2 , 20 . 2 . 1 . Each application server typically executes one or more processes which collaborate together to provide application functionality 40 , 60 . For example application server 10 . 1 . 1 executes processes p 1 , p 2 , p 3 (which together denote an application—not referenced), whilst application server 10 . 1 . 2 executes processes p 4 , p 5 , p 6 . The processes making up applications 40 and 60 do exist but are not shown in the figure.
[0040] Certain application servers may be grouped together into clusters (one shown) 30 . Certain processes run a messaging engine (ME) thereby enabling an application to access the destinations owned by the ME and to connect to a bus 70 , 80 in order to access destinations owned by other MEs. For example p 1 on application server 10 . 1 . 1 executes ME 1 which owns destinations (not shown) and which provides a connection to bus 70 .
[0041] Via busses 70 and 80 , application servers are able to communicate with one another.
[0042] Client 50 also runs an application 60 which communicates with ME 5 and is thus able to access bus 80 .
[0043] The present invention, in accordance with a preferred embodiment, enables an application to specify a scoping constraint (connection scope), when connecting to a messaging engine. Such a scoping constraint can be used to enforce the use of a suitably “close” (proximate) messaging engine. In the preferred embodiment, “close” means any engine that may be connected to whilst avoiding or minimising networking delays.
[0044] TRM (Topology Routing Manager) component 90 collaborates to achieve a connection request with a WLM component 100 . WLM keeps track of all the constituent parts of the environment described with reference to FIG. 1 . When a messaging engine connects to a bus, it registers with WLM.
[0045] Note, there may be more than one WLM, each WLM being responsible for a subset of the environment—E.g. A group of hosts, nodes or application servers.
[0046] WLM is described in more detail with reference to FIG. 2 . WLM includes a registration component 120 . When a messaging engine connects to a bus, that engine registers with WLM using component 120 . Such a registration involves providing, by way of example, WLM with the following information:
[0047] ME id; bus name; cluster id; host id; node id; application server id; and process id.
[0048] The ME of course knows its own id and the name of the bus that it connects to. The ME queries its owning process for its process id, the process queries its application server for an application server id, the ME queries whether it is part of a cluster and so on. In this way, suitable information is provided to the ME and the ME in turn provides this to WLM upon registration.
[0049] Such information is then stored by WLM in directory 110 . Thus it can be seen that ME 1 connects to bus 70 , is not part of a cluster, is owned by process 1 , within application server 10 . 1 . 1 . That application server is on node 10 . 1 and the node sits on host 10 .
[0050] WLM also includes an ME Sub-Setter component 130 but this will be described in more detail later.
[0051] FIG. 3 illustrates the TRM component in more detail and FIGS. 4 and 5 show the processing of the preferred embodiment. FIG. 4 is from the point of view of TRM and FIG. 5 is from the perspective of WLM.
[0052] TRM receives connection requests from applications. An application may reside on a client 50 or on an application server. Such connections are received by Connection Request Receiver 170 (step 200 ) A connection request may include the location of the requesting application (alternatively this may be determined from administrator configured information or from the context in which the request is made etc.), a bus name (if there are multiple possibilities); and a connection scope. The connection scope may be tailored in accordance with the following options:
[0053] Connect to a messaging engine in the same:
Cluster; Application Server; Process; Node; or Host.
[0059] If “same bus” is specified, then any messaging engine on a particular bus may be chosen.
[0060] The connection request is received from the application, information is then extracted from such a request and is provided at step 210 to WLM (WLM Querier 180 ). Extracted information may include the requesting application's location, the name of the bus to connect to, and a connection scope.
[0061] WLM operates using such information to recommend an appropriate ME to the application (step 300 ). WLM queries its directory 110 using ME Sub-Setter Component 130 (step 310 ). A subset of MEs satisfying the specified connection scope is provided to TRM (step 320 ). The results are received by TRM's Receiver Component 190 (step 220 ). TRM then selects an appropriate ME (step 230 ) and informs the application of the ME to which it is to connect (Application Informer 195 , step 240 ).
[0062] For example, the application comprising processes p 1 , p 2 and p 3 may specify that a connection scope of “same process” is required. From WLM's directory WLM would determine that ME 1 satisfies the required criterion.
[0063] On the other hand, the same application may specify “same host”. From FIG. 1 it can be seen that this would provide a choice of ME 1 , ME 2 or ME 3 .
[0064] WLM provides the subset of ME's to TRM and TRM would then select one of the MEs. In accordance with a preferred embodiment, TRM is likely to select the ME with the closest proximity to the application. This can be determined by querier WLM's directory information. Thus once again a suitable choice is ME 1 since this sits within the same process as the application itself.
[0065] Note, in order for TRM to be able to determine which ME of a subset is the most suitable, WLM needs to provide TRM with information from its directory 110 about each ME in the Subset. In an alternative embodiment, WLM does not provide TRM with subset information but rather selects an appropriate ME from the subset itself.
[0066] Thus the present invention, in accordance with a preferred embodiment, permits an application to specify a connection scope. In this way an application's connection to a messaging engine may be controlled resulting in increased performance.
[0067] For example, certain nodes may have access to particular resources (e.g. databases). By specifying a connection scope of “same node”, it is ensured that the application will have access to appropriate resources.
[0068] Clusters can be used for certain functions, an example being that a cluster may be managing a particular messaging destination. By specifying a connection scope of “same cluster” an application can ensure that it will be granted a connection to an ME that is locally performing physical processing related to that destination.
[0069] A connection scope property of “same host” eliminates any network communications.
[0070] A connection scope of “same application server” permits interprocess communications but again eliminates network communication. Such an option may be chosen for reasons of communication efficiency.
[0071] Thus the present invention permits applications to scope their connections to a set of resource appropriately.
[0072] Note, whilst the present invention has been described in terms of messaging and messaging engines, the invention is not limited to such. Rather, the invention may apply to any set of connected resource managers and their resources.
[0073] Note, the connection scope information may be obtained in a number of different ways. For example, it may be hard-coded into the application itself; it may be obtained by reading separate profile information; a user may be prompted for the information etc.
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Disclosed is a method, apparatus and computer program for determining which resource manager of a plurality of resource managers an application may be connected to, given a connection request. A connection request is received which specifies a connection scope. The connection scope specifies the desired proximity of a suitable resource manager relative to the application's location. The application's location is determined and so are any resource managers that satisfy the connection request. The connection requester is then informed of at least one resource manager which satisfies the connection request.
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RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 07/518,040 filed May 2, 1990, now pending which is a continuing application of U.S. Ser. No 07/199,556 filed May 27, 1988, now U.S. Pat. No. 5,108,790, which is a continuation-in-part of U.S. Ser. No. 07/101,908 filed Sep. 28, 1987, now U.S. Pat. No. 4,839,115, which is a divisional of U.S. patent Ser. No. 07/053,561 filed May 21, 1987, now U.S. Pat. No. 4,732,782, which is a continuation-in-part of U.S. Ser. No. 06/843,316 filed Mar. 24, 1986, now abandoned. U.S. Ser. No 07/518,040 is also a continuation-in-part of U.S. Ser. No. 07/168,715 filed Mar. 16, 1988, now U.S. Pat. No.; 5,219,222, which is (a) a continuation-in-part of application U.S. Ser. No. 07/053,561, filed May 21, 1987, now U.S. Pat. No. 4,732,782, which is a continuation-in-part of U.S. Ser. No. 06/843,316, filed Mar. 24, 1986, now abandoned; and (b) a continuation-in-part of U.S. Ser. No. 07/049,906, filed May 15, 1987, now U.S. Pat. No. 4,747,878, which is a division of U.S. Ser. No. 07/843,316 filed Mar. 24, 1986, now abandoned. All of the foregoing applications and patents are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the treatment of hazardous waste produced by industry, and preferably liquid hazardous wastes.
2. Prior Art
One of the most desirable ways of disposing of hazardous waste chemicals, e.g. radioactive waste, carcinogenic waste, etc., and reducing hazards to acceptable levels, is to solidify such chemicals. Many studies have been made on mixing such hazardous materials with concrete composed of cement, sand and gravel and sometimes other additives to make a solid mass. Such a method poses problems in contamination of the mixing vehicles, spillage and ventilation problems. Additional methods used are to build containers of concrete, steel, glass and combinations thereof to contain such chemicals for an indefinite period. Such methods have proven to have unacceptably high failure rates. To date, concrete encasement is probably the best method. Concrete, however, as presently used in industry has a high percentage of water of hydration leaving little opportunity for the cement fraction to absorb the excess hazardous liquids to immobilize the waste therein, i.e. the high percentage of the water of hydration uses up most of the concrete's ability to absorb liquid.
It is a common practice to process liquid hazardous or radioactive materials by adding absorbants in an attempt to simplify handling and transportation as well as eventual storage thereof. The materials that have been used heretofore include diatomaceous earth, vermiculite or expanded mica such as zonolite and krolite, Portland and Gypsum cements, as well as clay materials such as calcium bentonites. The problem with such materials is that only a relatively small amount of liquid can be absorbed or otherwise treated with less than satisfactory results and complicated mixing equipment is required which becomes contaminated. For example, liquid materials may be transported and disposed of in fifty-five gallon drums. However, it has been found that with the use of these absorbants, solid compositions cannot be achieved or if temporarily achieved, liquid separation occurs during transportation or storage. Any separated or free standing liquids are especially undesirable because of the potential danger of leakage from a ruptured or open container.
The following patents are relevant hereto:
______________________________________U.S. Pat. No. Inventor______________________________________3,983,050 Mecham4,116,705 Chappell4,174,293 Colombo, et al4,775,494 Rowsell et al.4,855,083 Kagawa et al.4,913,835 Mandel et al.______________________________________
Mecham (U.S. Pat. No. 3,983,050) describes the use of dry cement powder which is added to a metal canister containing dry radioactive calcined wastes so that the cement powder is in contact with the inner surface of the wall of the canister before the canister is sealed. If the container wall fails moisture from the environment contacts the cement and solidifies the cement to thereby seal the wall. In an embodiment the cement is mixed with the dry waste and placed in the metal canister.
Chappell (U.S. Pat. No. 4,116,705) describes a process which comprises treating hazardous waste with (i) an aluminum silicate or an aluminosilicate and (ii) a Portland cement, in the presence of water to form a slurry and allowing the slurry to set into rock and a crystal matrix having encapsulated therein the hazardous waste.
Rowsell et al., (U.S. Pat. No. 4,775,494) discloses the concept of disposing of radioactive or hazardous liquid waste by placing the liquid in a container and adding sodium montmorillonite over intervals until the composition is substantially solid in the container.
Colombo et al. (U.S. Pat. No. 4,174,293) describes a process for disposing of aqueous waste solutions by dispersing the solution in situ throughout a mass of powdered Portland cement in a container, curing the cement and thereafter impregnating the cured cement with a mixture of a monomer and polymerization catalyst and polymerizing the monomer. The container is then appropriately stored.
Kagawa et al. (U.S. Pat. No. 4,855,083) describes a solidifying agent comprising slag dust, silicates, water-soluble, high molecular weight compounds, metal salts of an organic acid and calcium carbonate. The solidifying agent is mixed with organic halogenides, such as PCB, to form solid composites which are subsequently burned.
Mandell et al. (U.S. Pat. No. 4,913,835) teaches spraying a particulate composition containing an organic acid neutralizing agent on a hazardous alkali spill.
Still further, at present, it is generally essential that a cementitious composition is mixed with water before placement in order to moisten the cementitious particles for the start of hydration and lock in place the hazardous waste. Generally, some type of mixing is required. Some manufacturers of premixes, usually in a container having instructions thereon, have put a dry premix cementitious composition in a hole or container and then recommended adding the water on top or through tubes. Some manufacturers have put premixes in bags and dropped the mixes, while in bags, through the water, then after the bags are in place, letting water penetrate through the bag to the mix. However, these systems do not permit full hydration of the cementitious composition. Mortar mixers, concrete mixers and hand mixing have been utilized to obtain a uniform distribution of the appropriate amount of water in the cement. According to the prior art, the quantity of water to be mixed with the cement must be controlled to a very narrow range, and too little or too much water will produce an ineffective or unusable material. Cementitious mixtures could not be placed in a dry state directly into water or on to a wet surface without first wetting and mixing the dry components with water.
In summary, solidification of waste materials with cementitious compositions is known, however, such is accomplished by either mixing the waste material with the cementitious composition to obtain essentially complete hydration or adding the liquid to the cementitious composition with or without mixing. There is no teaching or suggestion in the art of adding the cementitious composition to the hazardous waste without mixing to produce a solidified mass.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of this invention to provide a method of solidifying hazardous waste compositions so that when transported or buried, they will not be environmentally hazardous.
A method is provided for immobilizing hazardous waste comprising:
providing a dry, optionally fast setting, cementitious composition, the cementitious composition having a set time and in the form of finely divided particles of at least one cement binder;
providing a volume of water containing an amount of hazardous waste; and
placing, e.g. an amount of dry cementitious composition into the volume of water. Preferably the volume of water being greater than the amount necessary for hydration of the amount of the cementitious composition. The water contacts the particles of the cementitious composition and hydrates the particles.
The major portion of the particles of the cementitious composition have approximately the same drop rate through the volume of water, allowing the cementitious composition to drop through the water, displacing the excess water as a result of the dropping of the cementitious composition. The hydrated cementitious composition is then allowed to form into a cured substantially non-segregated mass immobilizing the amount of hazardous waste.
What we have discovered is that by using dry cementitious formulas with or without aggregate of all sizes, with or without additives for various functions (e.g. increasing impermeability, strength, absorption control or drop rate) by pumping, blowing and pouring through liquid hazardous waste (which may or may not have been modified or diluted) we can form a solid mass which immobilizes the hazardous waste for reasonable, safe disposal and transportation.
Using such a dry cementitious mixture, the cement, with or without additional absorbants or with or without the addition of neutralizing chemicals, can increase multi-fold the amount of chemicals that can be absorbed and solidified on a unit volume basis. The method may be applied to small volumes of chemicals as well as multi-tons of chemicals in open pits. Additive chemicals and/or neutralizers that allow the dry system to hydrate the liquid waste can be added to either the dry cementitious portion or the liquid chemical portion.
The dry cementitious composition has finely divided particles of at least one cement binder. The composition is usually in a container, e.g. a bag having instructions associated therewith. The cement may be Portland cement, gypsum, high aluminum cement, or mixtures thereof, but is not restricted thereto. Magnesium phosphate or other fast-setting compounds may also be used. The major proportion of particles have approximately the same drop rate in water, so that when poured through water containing the hazardous waste the material does not appreciably segregate.
The cementitious composition may further include a filler component of sand or aggregate particles or a combination thereof, provided that the major portion of those particles have a drop rate in water containing the hazardous waste which is approximately the same as the cement particles. Also, the cementitious mixture should be able to absorb and/or combine with water in the amount approximately 50% by volume. The higher the amount of water the cementitious mixture can tolerate, the better the final product.
It is possible to use other additives in the cementitious compositions. Such additives may include, but are not limited to, accelerators, water reducing compounds, waterproofing agents, polymers, drying shrinkage inhibitors, wet shrinkage inhibitors, lime, pigments and the like, and may be added to improve or impart a particular property to the composition. A preferred additive is a "neutralizer" for the hazardous waste. By the use of the term "neutralizer" herein it is meant a compound or composition which converts the hazardous waste to a substantially less hazardous waste and/or prevents substantial leakage of the waste from the solidified cementitious composition.
This improved method of treating hazardous waste materials can be utilized by placing the water and hazardous waste in a fifty-five gallon drum and then by treating by the above procedure. Optionally lagoons, ponds, e.g. settling ponds may be so treated. The resulting composition may be handled, transported, and stored under a variety of conditions for extended periods of time without evidence of liquid separation or deterioration or leakage. These and other advantages will be more particularly described in the following detailed description.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention relates to dry cementitious compositions which are poured, trowled, tremied (elephant trunk) or sprayed through excess water or onto wet surfaces, said water containing a hazardous waste, without mixing, to hydrate the cement component and obtain solidified products after setting and curing which have immobilized therein the hazardous waste. Cementitious compositions of Portland cements, gypsums, high alumina cements, other specialty cements and combinations, as well as other chemicals such as magnesium phosphates, all can be successfully used, the only limitation being that at least one component of the cementitious composition is hydrated by or reacts with water.
The method of solidifying and immobilizing the hazardous liquid waste compositions according to this invention may be applied to a great variety of such materials. For example, in the radioactive waste disposal field, liquids which must be treated and disposed of include reactor plant liquid such as turbine, cutting and lubricating oils, solvent sludges which are used to decrease the reactor components such as Freon TF, cleaning solvents such as Stoddard solvents, decontamination solvents and aqueous mixtures of the above noted hydrocarbon materials, particularly those containing between from five to about seventy-five percent hydrocarbons and even up to one hundred percent hydrocarbons. In addition a great quantity of such wastes are aqueous liquids containing over about ninety-five percent water contaminated with a radioactive material, such as grease from reactor plant turbines. Hospital sourced contaminated liquids contain radioactive materials used in cancer treatments. From such sources, particularly common materials include the radioactive cobalts such as cobalt 57, cobalt 58, and cobalt 60, cesium, plutonium and uranium isotopes, and the like. However, it is to be understood according to this invention, that any radioactive waste materials may be treated according to the method of this invention.
Other common hazardous waste materials include acids, bases, chlorinated hydrocarbons including PCB, dioxins, and the like. Again, these as well as the radioactive materials may be in substantially aqueous liquids, particularly those having ninety-five percent or more water, or they may be in aqueous mixtures containing substantial amounts of hydrocarbons.
The hazardous waste may also contain aluminum, boron, cadmium, chromium, copper, iron, lead, manganese, nickel, tin, zinc, arsenic, antimony, barium, cobalt, gallium, hafnium, mercury, molybdenum, niobium, strontium, tantalum, thorium, titanium, vanadium, zirconium, selenium, or silver or a compound of any of the elements. It may contain anions such as fluoride, sulphate, phosphate, nitrate, nitrite, sulphite, cyanide, sulphide, thiocyanate, thiosulfate, potassium ferricyanide or ferrocyanide and it may contain an acid, alkali, protein, carbohydrate, fat, drug, Prussian or Turnbulls blue, detergent, mineral oil, tar or grease.
Other examples of wastes which may be treated by this invention are:
Mining and Metallurgy Wastes e.g. mine tailings, drosses, especially those containing As, Cd, Cr, Cu, CN, Pb, Hg, Se, Zn or Sb; Paint Wastes, paint wastes stripped of solvent produced by heavy industry; Sulphide Dye Liquors; Inorganic Catalysts used in a wide range of industry e.g. petrochemical, general chemical or dyestuff industries; Electrical and Electronic Industry Wastes such as printed circuit wastes; Printing and Duplicating Wastes; Electroplating and Metal Finishing Wastes; Explosives Industry Wastes; Latex Wastes and cyanide, mercury and zinc waste produced by the rubber and plastics industry; Electric Battery production wastes; Textile wastes; Cyanide, arsenic, chromium or other inorganic waste produced by the petrochemical industry; Leaded Petrol Sludges; Pulp and Paper Industry Wastes; Leather Industry Wastes; Inorganic sludges produced by general chemical industry; Asbestos Waste; Scrubbing Liquors from incinerators and gas cleaning equipment; Silts and dredgings from waterways; Spent Oxides for gas purification; Cement and Lime Industry Wastes, such as dusts collecting in electrostatic precipitators; Cyanide Case Hardening Wastes; Incineration Ashers e.g. fuel oil ashes from burning fuel oil in power stations, ash from burning domestic refuse and sewage sludge, etc.; Sewage Sludges; Smelting and Metal Refining Industry Wastes e.g. from metal smelting and refining, e.g. aluminum, zinc, copper or lead; Iron and Steel Industry Wastes; Sulphide Wastes e.g. calcium or sodium sulphide; and Acid and Alkaline Wastes.
As stated previously, it is preferred to use a "neutralizer" for the hazardous waste as an additive to the cementitious composition, although this invention also contemplates the addition of this "neutralizer" to the hazardous waste.
This invention is not limited to the waste substances and "neutralizers" or combinations thereof previously mentioned.
By the use of the term "neutralizer" herein it is meant a compound or composition which converts the hazardous waste to a substantially non-hazardous waste and/or prevents substantial leakage of the waste from the solidified cementitious composition.
The specific neutralizer and amounts used is highly dependent on the type of hazardous waste. Specific neutralizers and effective amounts thereof for specific hazardous wastes are as follows:
______________________________________Hazardous Waste Neutralizer Effective Amount______________________________________Barium K.sub.2 SO.sub.4 and Fumed Silica Total neutralizer(s)Mercury Sulfur and Fumed Silica is present in at leastNickel Na.sub.2 CO.sub.3 and Fumed the stoichmetric Silica equivalent weight ofPhenylenediamine Resorcinol and Ca(OH).sub.2 the hazardousPhenol Vinyl Acetate-Ethylene waste. CopolymerLead Lumnite Cement (HAC)Mercury Sulfur and Fumed Silica______________________________________
Fast setting cementitious compositions can be used. By the use of the term "fast setting" herein it is meant a cementitious composition which sets faster than the most common Portland cement, i.e., type I or type II.
By the use of the term "cement binder" herein it is meant is a material, usually of a cementitious nature, which sets or cures upon contact with water by hydration to form a solid mass which is useful for forming blocks, shapes, structures, walls, floors, or other surfaces for use as a supporting or load bearing member. The cement binder may be used alone or with various additives and fillers, usually sand or aggregate, to form the desired member after setting and curing. In addition to the well known cement binders, such as Portland cement, modified Portland cement, aluminous cement, gypsum and its variations, magnesium phosphate cements and the like, other materials, such as the silicates, are also contemplated as being within the scope of this term since they perform in a manner similar to the cements. Aluminum silicate is a specific example of this type material, and it is used for specialty applications due to its relatively high cost compared to the other cement materials previously mentioned. Other specialty cements may be utilized.
When the formulations of these cementitious compositions are properly controlled, the problems of thorough wetting of the cement without overwetting, of segregation of components, and of loss of compressive strength of the cured product are greatly reduced or eliminated.
Where cement coatings are desired, the surface area to be coated is first pre-wetted and saturated with water containing the hazardous waste. The dry cementitious mixture is placed on the surface, instantly reacting with the wet surface. If additional layers or a greater thickness of the coating is needed, the first cement layer can be pre-wetted and the dry composition sprayed directly thereupon to increase the thickness and structural strength of the overall coating.
On horizontal surfaces, which may or may not have a hazardous waste thereon, the area to be poured with cement is flooded with water containing a hazardous waste, then the dry cementitious compositions of the invention can be poured into the water. The excess water is displaced by the cementitious composition, and the composition is then allowed to cure immobilizing the hazardous waste therein. This provides a fast, simple immobilization of the hazardous waste with cement without the need for tools, mixing apparatus, water measurement aids or the like.
Controlling the rate of hydration may lead to many applications. For instance, for coating vertical surfaces, a very fast setting cementitious composition can be used to eliminate the problems of running, sagging or failure to bond. For situations where the surface particles have not been properly wetted, additional water may be applied to the surface for more activation and further finishing. Preferred set times for immobilizing hazardous waste are less than about 10 minutes and, where desirable less than about 5 minutes, with longer set times preferred for larger volumes of liquid. It may also be desirable to provide for "long" set times, e.g. over one day to minimize the heat of hydration, to obtain more complete reaction to enhance the formation of a monolithic structure or for long installation requirements.
In the past, there has always been difficulty in controlling the amount of water for immobilizing hazardous waste. This problem is solved by this invention because the amount of water is controlled by the formulation of the dry cementitious composition itself. For example, water containing the hazardous waste can be placed a container, e.g. drum, and then the dry cementitious material may be placed therein by pouring, spraying, or screening into the container until the desired level is reached. The rate of setting of the cementitious mixture can be designed to meet the needs of the particular application. The amount of water required depends on the specific composition and application used.
In certain circumstances, a cavity, e.g. waste disposal pit, could have a small amount of water placed into it and then the first part of the cementitious mixture placed into the water. While this placement is taking place, additional water containing hazardous waste could then be placed into the hole by various methods simultaneously with the placement of the rest of the cementitious mixture. When the final quantity of the cementitious mixture is reached, the entire surface area could be sprayed for trowling or other finishing purposes as could be done when the entire mixture is poured through water.
In the situation where the cavity or container is porous and cannot hold water, it is possible to thoroughly wet the surfaces of the cavity and then introduce a fast setting cementitious mixture to partially seal the surfaces of the hole to retain water. It is then possible to pour the water containing the hazardous waste into the lined container and proceed as discussed above.
The control of density and size of the dry components and the rate of drop through water is essential for the proper performance of the cementitious mixtures. The ability to use materials of various sizes and densities, whose drop rate would otherwise be higher if a slow setting cementitious mixture was used, is enhanced by the increased rate of the water activation of the cementitious particles to form a homogeneous mixture.
The use of specific cementitious compositions may be varied or adjusted to meet the needs of the particular application. The most ideal situation is to balance the drop rate for all the dry ingredients and to control the setting time of the cement so that all particles will be properly hydrated and integrated with the aggregates, if any. The setting time of the binders can be accelerated to a few seconds or slowed up for days, depending upon the selection of cement component.
In some compositions, no curing agent is required. Furthermore, the compositions may contain numerous chemicals or additives that are compatible to the system for the purpose of improving or imparting certain properties. Additives such as accelerators, water reducers, bonding agents, curing agents, or pumping or waterproofing aids may be added to the compositions of the invention. These additives or modifying agents can be added to the water or to the cement mix, in any order or combination.
If aggregates are found to be too heavy, smaller aggregates or lighter weight aggregates can be used to keep the density of the overall system in balance.
The present invention provides the following:
1. Dry cement can be used.
2. Cement and sand can be used.
3. Cement, sand and aggregates can be used.
4. All types of cements can be used.
5 All types of cementitious particles, such as gypsums, limes and so forth can be used.
6. All types of chemical cements, even with water soluble parts, can be used.
7. No wet mixing or blending equipment is required.
8. No addition of water to cementitious mixes is required before placement, thus avoiding clean up of equipment and waste.
9. When placements under deep water conditions where tremes, elephant trunks or pipes would be required, the material herein can be placed dry in the tube and activated by available water at the end of the line, thus keeping all conveyances clear of wet cement or contaminated water. too low in mixtures to prevent
10. When cement contents are proper strength development or prevent over-absorption of water, resulting in weak or segregated mixes, more cement may be added, or water absorption material may be added, to prevent excess water from decreasing the quality of the mix.
Cement mixes which are too low in absorbent capacity should have some additional water absorption agent in the mix to prevent overwatering and segregation. Ideally, cementitious compositions of the mixtures should have the maximum amount of water absorbency possible. The higher the ratio of chemical bonded water to the binder, the better and more versatile a product will be achieved.
Cementitious mixtures containing about 20 percent by weight cement may or may not need additional cements or water absorbers, depending on the application. Generally, at least 35 percent by weight of a cement binder is preferred for use in the composition and methods of this invention.
The cement composition can be altered with any of a multitude of cement binders including, but not limited to, Portland cement, magnesium phosphate cement, magnesium cement, high aluminous cement and other cementitious compositions whether totally cement binder and/or Portland cement binder and/or polymers. These compositions are then poured into the liquid waste and left to hydrate and solidify. These solidifications can take place in minutes, hours or days depending on conditions. A deep pour of a dry cementitious composition may be done in layers or in mass, by pouring slowly, with the required set times determined by the situation.
In many cases some of these hazardous waste chemicals can be solidified by merely diluting with water and/or additives in order for the cementitious binder to hydrate into a solid mass using up the waste chemicals.
These solidified wastes, if properly formulated, can be used for foundations and many other building functions provided leaching of radioactive or otherwise harmful materials is controlled by using impermeable cementitious mixtures, waterproofing coatings, radiation shielding, impermeable coatings, and certain chemical coatings that would not react with the basic mass.
There are an indeterminate number of waste chemical compositions and job conditions which must be handled. Each situation must be analyzed carefully, but the principle of using a cementitious binder in the dry state and pouring it into the container of whatever size or into the spillage area of whatever coverage and solidifying the harmful waste into an acceptable mass for disposal is the most effective way known today to rapidly eliminate hazardous liquid waste situations.
The same method may be used to dispose of solid hazardous wastes, e.g. radioactive solids (for example, metal or concrete parts). This may be accomplished by encasing these solid hazardous waste materials in a container, covering them with water and pouring the specially adjusted cementitious compositions through water to solidify the mass.
For situations where the radioactivity is extremely strong or the fumes or chemicals particularly hazardous, the cementitious composition can be modified to contain the additives, i.e. neutralizers, necessary to modify the chemicals so that they would react to form a solid mass with the cementitious composition, which can be then blown or pumped dry into the liquid waste from a safe distance without injuring individuals or causing unnecessary pollution to mixing equipment. The encased end of the blowing or pumping unit can be cut off and forms a part of the encasement or solidification.
The solidified composition produced according to this invention may be used for example, for landfill, hardcore, in the manufacture of constructional materials, in the preparation of grout, for the encapsulation of other wastes such as domestic refuse, or in land reclamation from diffused mines, quarries, excavations, lakes, estuaries and the sea. Domestic wastes which do not lend themselves to the process of the invention may however, be buried in a mass of the slurry or rock and this will overcome the hazards of odor and rodents often associated with their disposal.
While using liquids other than water, such as two component thermosetting organic compounds, an aggregate or sand can be dropped through the liquid or chemicals, causing the final mixture to be blended by gravity or by the solid ingredients passing through the liquid, which will result in a hardened mass of aggregate or sand and chemical.
EXAMPLES
The scope of the invention is further described with the following examples which illustrate preferred embodiments of the invention and which are not to be construed as limiting the scope of the invention.
In the examples that follow, the components of each cementitious composition were manufactured of finely divided particles having substantially the same drop rate in water, so that the advantages previously discussed could be achieved.
Example No. 1
IMMOBILIZATION BY SOLIDIFICATION OF A HAZARDOUS SOLUTE (BARIUM)
______________________________________DRY BLEND______________________________________70% Lumnite Cement20% K.sub.2 SO.sub.410% EMS - 960 Fumed Silica______________________________________
POURED DRY BLEND INTO WATER (CONTROL)
Poured dry blend into 3 cubes with 60 ml of water in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 3 Days 250______________________________________
Material absorbed all liquid without any spillage. Top surface sprayed.
POURED DRY BLEND INTO TEST SOLUTION (5% BARIUM ACETATE AND 95% WATER)
Poured dry blend into 3 cubes with 60 ml of Test Solution in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 3 Days 250______________________________________
Material absorbed all liquid without any spillage. Top surface sprayed.
Example No. 2
IMMOBILIZATION BY SOLIDIFICATION OF A HAZARDOUS SOLUTE (MERCURY)
______________________________________DRY BLEND______________________________________80% Lumnite Cement20% Sulfur10% EMS - 960 Fumed Silica______________________________________
POURED DRY BLEND INTO WATER (CONTROL)
Poured dry blend into 2 cubes without 60 ml of water in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 4 Days 675______________________________________
Material appears hydrophobic. Material absorbed all liquid; top surface sprayed.
POURED DRY BLEND INTO TEST SOLUTION
Mercuric Chloride, a 5% Solution, 95% Water
Poured dry blend into 3 cubes with 60 ml of Test Solution in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 4 Days 475______________________________________
Hydrophobic material absorbed all liquid; top surface sprayed.
Example No. 3
IMMOBILIZATION BY SOLIDIFICATION OF A HAZARDOUS SOLUTE (NICKEL)
______________________________________DRY BLEND______________________________________80% Lumnite Cement10% Sodium Carbonate10% EMS - 960 Fumed Silica______________________________________
POURED DRY BLEND INTO WATER (CONTROL)
Poured dry blend into 2 cubes with 60 ml of water in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 4 Days 300______________________________________
Material absorbed all liquid; top surface sprayed.
POURED DRY BLEND INTO TEST SOLUTION
Nickel Sulfate, a 5% Solution, 95% Water
Poured dry blend into 3 cubes with 60 ml of Test Solution in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 4 Days 125______________________________________
Material absorbed all liquid; top surface sprayed.
Example No. 4
IMMOBILIZATION BY SOLIDIFICATION OF A HAZARDOUS SOLUTE (PARA-PHENYLENEDIAMINE)
______________________________________DRY BLEND______________________________________68% Portland Type II Cement 2% Resorcinol10% Ca(OH).sub.220% Fly Ash______________________________________
POURED DRY BLEND INTO WATER (CONTROL)
Poured dry blend into 2 cubes with 60 ml of water in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 4 Days 225______________________________________
Cube colores--yellow, red. Material absorbed all liquid; top surface sprayed.
POURED DRY BLEND INTO TEST SOLUTION
P-Phenylenediamine, a 1% Solution in 99% Water
Poured dry blend into 3 cubes with 60 ml of Test Solution in each 2" cube mold.
______________________________________Cube # Age Psi______________________________________1 4 Days 187______________________________________
Cube colors--yellow, dark brown, reddish brown. Cement agglomerates would skate around on water surface during addition. Material absorbed all liquid; top surface sprayed.
While is apparent that the invention disclosed herein can fulfill the objects above stated, it will be appreciated that numerous modifications and embodiments may be devised by those skilled in the art, and it is intended that the appended claims cover all such modifications and embodiments as fall within the true spirit and scope of the present invention.
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A method of immobilizing a hazardous waste is provided. The method comprises providing a dry cementitious composition capable of hardening and in the form of finely divided particles of at least one cement binder, placing an amount of the dry cementitious composition into the hazardous waste with or without an additional added volume of water, without any type of physical mixing of the cementitious composition and water other than the mixing which occurs merely by applying the cementitious composition into the water. The major portion of the particles of the cementitious composition have approximately the same drop rate through the volume of water. The water contacts the dry cementitious composition when poured into the volume of water to hydrate the particles of the dry cementitious composition, the particles of cementitious composition dropping through the water to displace excess water and form the hydrated cementitious composition particles in a substantially non-segregated mass. The hydrated cementitious composition is then allowed to set and cure to a solid mass. The set time may vary from less than a few seconds to many hours and even days to immobilize the hazardous waste. The cementitious composition may have a neutralizer for the hazardous waste.
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BACKGROUND OF THE INVENTION
This application is a continuation-in-part of application Ser. No. 07/847,294, filed Mar. 6, 1992, entitled "Therapeutic Frequency Modulator", which application is herein incorporated by reference, abandoned.
1. Field of the Invention
The present invention concerns therapeutic radiation devices used in the treatment of the human body. More particularly, the present invention concerns therapeutic radiation devices which help effect the reduction of pain and swelling relating to physical trauma incurred by the human body.
2. Description of Prior Art
The use of therapeutic radiation devices to assist in treating physical trauma to the human body is a well known. One therapeutic device, through the application of light rays, treats skin conditions. Examples of such devices are found in U.S. Pat. Nos. 2,183,726 and 3,658,068. In U.S. Pat. No. 2,183,726, issued Dec. 19, 1939 to Sommer et alia and entitled "APPARATUS FOR THE TREATMENT OF THE SKIN OR THE LIKE", the skin treating device thereof utilizes an electric lamp to provide heat and light rays to the skin. The heat and light rays condition the skin to receive skin food or cream which is massaged into the skin by the skin treating device. The light rays from the bulb are filtered through red or blue colored filters. This device is dedicated to skin treatment and does not treat or otherwise address the pain and swelling accompanying trauma to the human body.
U.S. Pat. No. 3,658,068 issued Apr. 25, 1972 to McNall and is entitled "METHOD OF TREATING HYPERBILIRUBINEMIA". McNall teaches is a therapeutic device for treating hyperbilirubinemia, also known as "bilirubin" in newborn infants. This device is a mercury vapor lamp dedicated to treating this one condition. The lamp does not treat any pain or swelling connected with trauma to the human body.
Another type of therapeutic devices are the devices that have direct contact with the human body and use electric current to provide therapeutic benefit to body surfaces. For example, U.S. Pat. No. 785,366, issued Mar. 21, 1905 to Machlett and entitled "VACUUM ELECTRODE", teaches a method of destroying germ organisms by direct contact of the therapeutic device upon the diseased area of the body or skin. This is accomplished by applying electric current through an electrode directly onto the surface of the body. The electrode focuses the current directly to that portion of the diseased skin tissue to be treated thereby destroying microorganisms and germs located at the treatment site. The electric current also aids healthy tissue growth. This electrode does not treat any deep seated traumas, swelling and deep pain, that are present at the site.
Another example, U.S. Pat. No. 2,745,407, issued May 15, 1956 to Mueller et alia and entitled "OZONE THERAPEUTIC DEVICE", is a device which uses a gas tube, charged by an electrode, to charge the environment at or near the diseased skin or tissue area. This device initiates an electric charge which produces a positive ozone environment which changes the oxygen environment surrounding the diseased tissue thereby facilitating healing. There is no teaching in this patent of any treatment of swelling or deep seated pain caused by trauma.
In a further example, U.S. Pat. No. 1,266,287, issued May 14, 1918 TO Longoria and entitled "HIGH FREQUENCY APPARATUS", teaches a high frequency device used for therapeutical treatment of the body. The device discloses an electrode which applies ultraviolet rays directly to the skin surface. Different electrodes are used depending on the area, internal or external, of the body to be treated. Again, the device treats the immediate area of the skin which it touches, but does not affect the deep-seated pain or swelling that may be caused by trauma.
U.S. Pat. No. 4,930,504 issued to Diamantopoulos et alia and is entitled "DEVICE FOR BIOSTIMULATION OF TISSUE AND METHOD FOR TREATMENT OF TISSUE". Diamantopoulos et alia teaches a device of laser light technology to provide therapeutic radiation to treat portions of the body of a patient. The device uses multiple laser diodes to produce infrared and ultraviolet radiation to treat such injuries as inflammations, burns, wounds, ulcers, deficient circulation, pain, nerve degeneration, shingles infections, muscle and ligament damage, arthritis and other types of injuries. This device treats injuries with deep penetrating radiation, but the device must not touch the skin or it could cause surface tissue damage and the device is expensive.
It would be desirable to provide a therapeutic device which filters the energy delivered by a radiating unit to provide treatment to reduce swelling and pain to traumatized portions of the body, which permits contact with the skin and which is relatively inexpensive.
SUMMARY OF THE INVENTION
The therapeutic radiation device of the present invention is used to overcome deep seated swelling and pain from diseases and traumas, as well as surface diseases and trauma of the body. The radiation device comprises:
(a) a housing, the housing comprising:
(1) a hollow body, the body having a first portion and a second portion; and
(2) a handle, the handle integrally formed with the body proximate the first portion;
(b) a resonator coil being disposed within the housing;
(c) a radiation source, the radiation source being disposed within the housing, the radiation source having a first end and a second end, the first end of the radiation source being removably connected to the resonator coil, the second end of the radiation source extending beyond the housing, the resonator coil energizing the radiation source, the radiation source emitting a beam of radiation;
(d) an interchangeable lens module, the lens module having a plurality of silicon granules and diamond granules disposed therein, the silicon and diamond granules being attached to each other, the lens module being substantially cone shaped and having a cavity formed therein for attaching onto the radiation source, the lens module being removably connected to the housing;
(e) means for energizing the resonator coil, the means for energizing being electrically connected to the resonator coil; and
(f) a transformer, the transformer being electrically connected to the means for energizing, the transformer having a means to regulate the power supplied to the means for energizing.
The silicon and diamond granules cooperate to filter and diffuse the beam of radiation emitted by the radiation source.
The radiation source produces light waves when charged by the resonator coil. The light waves are filtered and diffused by the lens module. The extent of the filtering and diffusion is dependent upon the selection and diffusion of the silicon and diamond granules, and the color of the lens body. The lens is envisioned as being of different colors. Also, the light rays may experience some limited filtering by a lens module not made with silicon and diamond granules.
The amount of radiation to be filtered and diffused is controlled by the transformer. The transformer may have a means for adjustment which can manually or automatically regulate the amount of radiation emitted by the radiation source. Also, the transformer may provide for selection between continuous and remote operation. The transformer is connected to a standard 110 volt power source. When the transformer charges the therapeutic radiation device, radiation produced by the device is then used to treat swelling and pain within the human body.
Various features and advantages and other uses of the present invention will become more apparent by referring to the following detailed description and the drawings in which like reference characters refer to like parts throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present invention;
FIG. 2 is a cross-sectional side view of the preferred embodiment of the housing of the present invention;
FIG. 3 is a cross-sectional side view of a second embodiment of the lens module of the present invention; and
FIG. 4 is a bottom plan view with schematics of the transformer of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and more particularly to FIGS. 1 and 2, there is depicted therein a first embodiment of the therapeutic radiation device 10 of the present invention. The therapeutic radiation device 10 comprises a housing 20, a radiation source 22 disposed within the housing 20, means 24 for energizing the radiation source 22 and means 26 for engaging the means 24 for energizing the radiation source 22.
The housing 20 comprises a generally cylindrical first portion 30. The first portion 30 has a forward end, a rearward end, a top and a bottom. Formed of plastic or a lightweight metallic alloy, the first poriton 30 is sealed at its rearward end by a cap 36 threadingly engaged thereto. The cap 36 is formed of material similar to the first portion 30.
The housing 20 further comprises a second portion 32 formed materially similarly to the first portion 30. The second portion 32, as depicted in FIGS. 1 and 2, is formed in a truncated conical form, with the forward end having a smaller opening than the rearward end. The second portion 32 is connected, and preferrably threadingly engaged, at the rearward end thereof to the forward end of the first portion 30, in a manner commonly known. The extension of the second portion 32 is formed such that a radiation source 12 such as a bulb may be seated securely therein, as described herein further below.
A handle 34, comprising a generally cylindrical member formed of material similar to the first portion 30, is threadingly attached to the bottom of the first portion 30. An access slot 35 is formed at the base of the handle 34, such that electrical connection means 72 may be fed therethrough, as shown in FIG. 1. In an alternate embodiment, the handle 34 may be unitarily formed to the first portion 30.
The radiation produced by the present device 10 is generated by the interaction of the radiation source 22, the means 24 for energizing the radiation source 22, and the means 26 for engaging the means 24 for energizing. All of the elements 22, 24, 26 are contained within the housing 20, as set forth herein below.
The radiation source 22 comprises, in the preferred embodiment, an elongated light emitting bulb. The bulb 23 22 has a rearward end 46 and a forward end 48. The interior surface 33 of the second portion 32 is formed such that the rearward end 46 of the bulb 23 may be securely seated therein. The forward end of the bulb 23 extends beyond the forward end of the second portion 32 of the housing 20.
The bulb 23 is a gas-filled bulb, preferrably filled with xenon gas. The xenon bulb, when charged, emits a white light that is both a continuous light source and approximates the color spectrum of daylight. Thus, the beam of light produced from a xenon bulb is of the radiation wavelengths of the visible color spectrum, exhibiting strong infrared and nearinfrared radiation between 800 and 1000 nanometers, and demonstrate a large amount of ultraviolet radiation between 250 and 400 nanometers. While the therapeutic effects of light waves of the visible spectrum is undetermined, the therapeutic value of the waves from the infrared and ultraviolet light waves are amply demonstrated, as will be discussed herein further below.
Alternately, other types of bulbs may be used. One such alternative is a vacuum bulb produced and sold by P. J. Supply Co. of Chicago, Ill. The vacuum is not a true vacuum electrode, but is essentially a near vacuum electrode. The clear glass bulb has all the gas removed except for some gas remaining to, when electrically charged, emits a blue light, as is known. The blue light is a narrower color spectrum of the band; thus, it emits a smaller band of infrared rays. Also, other inert or noble gases may be used within the bulb 22. Like the vacuum electrode, the available treatment bands are narrower than xenon gas.
The bulb 23 receives an electrical charge from the means 24 for energizing the radiation source. The means 24 for energizing is, in the preferred embodiment, a resonance coil 38, which is well known. Alternately, the means 24 for energizing may comprise a resonator transformer of the variety known in the art and commonly available. The means 24 for energizing passes a charge into the bulb 23. The resonance transformer is commercially available from Electro-Tech of Chicago, Ill.
The means 26 for engaging the means 24 for energizing the radiation source is disposed within the handle 34. The means 26 for engaging comprises, in the preferred embodiment an electrical switch. The switch comprises a push-button switch 50, however other types of switches, such as a selector switch, may be elected. Such switches are well known and commercially available. The means 26 is connected to the means 24 for energizing and to electrical connection means 72 connected to a transformer, as set forth herein below.
The device 10 is connected to a transformer 70 by electrical connection means 72 means such as an electrical line at the handle 34. The transformer 70 controls the amount of energy received by the radiation device 10. The transformer 70 is connected by a cord 74 having a plug 76 to an electrical outlet, such as a wall outlet, so as to draw a 110 volt current, as is well known. The transformer 70 has means 78 for regulating the power supplied to the device 10, generally comprising a power adjustment switch 80, a preposition selector switch 82, a continuous use light 84 and a remote use light 86. The preposition switch 82 is positioned either in the "off" position, "continuous-use" position, or the "remote-use" position. All of the elements of the transformer 78 are well known and commercially available.
The power adjustment switch 80 permits the power to the radiation device 10 to be adjusted. Preferably, the transformer 78 should be able to provide power from a range of 0 volts to 50,000 volts. Settings between 60 to 70% of this full power have been found to be most effective for most treatments. Since each human being is different in need, the exact settings for treatment for an individual is adjustable to accommodate all needs.
The device 10 further comprises a lens module 52. The lens module 52 is disposed at the forward end of the second portion 32 of the housing 20. The module 52 comprises a mixture of silicon granules and carbon granules, indicated at 54. The silicon granules are, preferably, sand. The carbon granules are, preferably, diamond fragments. The carbon and silicon granules 54 are held together with a clear epoxy adhesive material, as is commonly known and commercially available.
The lens module 52 is, preferably, formed in a conical shape, with the point thereof truncated. This conical shape is preferred as it increases the amount of surface 56 for the body treatments. However, other suitable shapes may be elected, if desired. A channel is formed axially within the module 52, such that the forward end of the bulb 23 may be received therein.
The lens module 52 modulates the wavelength of light being emitted from the radiation source 22. The silicon and carbon granules 54 filter the light. The percentage of frequency modulation may also vary with the type of radiation source 22 used, but the frequency will always be less with a module 52 than without a module 52.
As noted, the lens module 52 may be different colors such as red, white, blue, green, orange, purple, yellow or any other color that would be translucent. The different colors not only alter the frequency of the light waves, but also filter out certain light wave colors. For example, the red module filters a portion of the infrared and near infrared wavelengths and the blue module filters ultraviolet wavelengths.
Referring to FIG. 3, there is shown another embodiment of the lens module 60 made from translucent plastic. However, a translucent glass may also be used. Also, the different colors may be used with the non-silicon lens body module in such a manner as to reduce the harmful effects of light from placing the radiating device 10 close to or upon the surface of the skin tissue of a human body.
Tests have demonstrated that the frequency of the light wave energy emitted by the radiation source is altered by 10% to 30% by the lens module 52 as measured at one-half inch from the module 52.
______________________________________MODULE COLOR MODULATION______________________________________No module 0%White 14% less freq.Blue 28% less freq.Red 14% less freq.Green 18% less freq.Orange 9% less freq.Yellow 19% less freq.Purple 7% less freq.______________________________________
Which lens module 52, 60 is used, or the color selected for that module, will be dictated by the nature of the injury to be treated. If the injury is on or near the surface of the skin, a lens module 52 that would provide for deep wavelength penetration would not be required. Also, a lens module 52 that would provide for surface absorption only would not be applicable.
In use, the therapeutic radiation device 10 is positioned on or near the area of the body to receive therapeutic treatment. The lens module 52 is placed on or near the skin surface of the traumatized area. The transformer 80 is turned on to either continuous use or remote use. The power supply from the transformer 70 is set by the adjustable switch at the desired setting. When the operator is ready to operate the radiation device 10, the operator pushes the push-button switch 50 on the handle 34 of the device 10. This thereby releases energy through the means for energizing 24, preferably a resonance coil 38 to the radiation source 22. The radiation source 22 illuminates, causing light waves to be directed to the portion of the body which is to be treated. The device 10 hereof reduces swelling of human body parts caused by trauma and diseases and thereby facilitates healing.
Ultraviolet radiation does not penetrate very far into human tissue. Therefore, the effects of the ultraviolet radiation on a human body is generally limited to surface or near surfaces effects such as treating skin diseases; for example, psoriasis, pityriosis rosea, acne and bacteria related to infections. However, there are serious side effects from ultraviolet radiation that must be guarded against, such as sunburn and certain forms of skin cancer.
Infrared radiation, on the other hand, is absorbed by the human body near the surface of the tissue and, in some spectrum ranges (780 to 1400 nm) will penetrate as far as the blood vessels. The deep penetrating infrared radiations are used to therapeutically treat such injuries as sprains, strains, bursitis, peripheral vascular diseases, arthrities, muscle pain and other aches and pains for which the infrared heat can give relief.
The application of heat to the human body skin surface produces effects in the deeper portions of the body, such as muscle relaxation, increased blood supply, and stimulated metabolic activity. Relaxation of the muscle tissue results in relief of pain, improved blood supply and reduced swelling, which all contribute to facilitating the healing process.
As noted, the radiation device 10 may also be used to treat surface or near surface injuries and diseases.
The present invention has been used to treat various conditions in clinical settings. The results of those clinical treatments have been reported by several chiropractic practitioners who have agreed to test the present invention. The results are summarized in the following examples.
EXAMPLE I
A female patient, age 55, complained of swelling in her knee. She demonstrated the swelling by attempting to place her hands around her knee, in an effort to touch her fingers, with no success. The patient was treated with a white lens module for three minutes. The patient experienced immediate reduction in swelling and was able to grip her knee with her hands and touch her fingers.
EXAMPLE II
A male patient, age 28, suffered constant pain from swelling of a broken arm that was confined in a cast. The patient was treated for two minutes with the present invention. The patient experienced immediate reduction of the swelling and pain was relieved.
EXAMPLE III
A male patient, age 38, complained of sinus swelling which interfered with his sleeping. A single treatment with the present invention for one minute relieved the sinus swelling and the accompanying sinus headache.
EXAMPLE IV
A male patient, age 35, complained of an unusual pressure or swelling with pain in his ear. The patient was treated with the present invention for thirty seconds and experienced immediate relief from the pressure and pain.
EXAMPLE V
A female patient, age 52, complained of pain and swelling in her back and left wrist. She also had some apparent skin lacerations. The patient was treated with the present invention for thirty seconds. The patient experienced a reduction of the swelling, relief from pain and reported significant healing of the skin lacerations the next morning.
EXAMPLE VI
A female patient, age greater than 60, suffered from a skin lesion on her ear, which had been described as being possibly cancer. The patient received eight treatments of twenty to thirty seconds which resulted in the lesion disappearing.
EXAMPLE VII
A patient complained of severe sinus headaches. The patient experienced relief after one treatment with the present invention for thirty seconds.
EXAMPLE VIII
A patient experienced severe joint pain for approximately eight years. The patient received two treatments of thirty-second duration, resulting in relief of the pain.
EXAMPLE IX
A lymphectomy performed on a patient induced arm swelling and pain after the operation. Two treatments, within one week of each other, relieved the pain and swelling.
EXAMPLE X
A stroke victim was unable to open and close a hand. The patient received one treatment which resulted in resolution of the problem.
The early indications are that the present invention may be used for various therapeutic purposes. Also, the treatments demonstrate that shorter and fewer treatment periods using the radiation device 10 produce more immediate and greater relief than the longer and greater number of treatment periods demonstrated by the prior art devices.
The instant invention has been described as being used for treatment of swelling and pain as a result of trauma in the human body and skin diseases and lesions. This description is not in any way intended to limit the therapeutic uses for the invention. A person trained in the art of healing may find many therapeutic uses for the radiation device.
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A radiation device for therapeutic use in the human body allows the application of light waves to an affected area of the body. A bulb, preferrably a xenon bulb, produces light which is passed through a lens module having silicon and carbon granules therein. By applying different lenses to the device, a variation in the wavelengths of light and radiation applied to an area is achieved. The device has a pistol-like housing to allow for controlled application of the radiation.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application of copending Ser. No. 560,519, filed Dec. 2, 1983, now abandoned.
FIELD OF THE INVENTION
The present invention relates to aqueous solutions having dilatant properties in which the aqueous solution contains an interpolymer complex which is a water soluble polymer backgone containing an anionic comonomer and a copolymer of a water soluble polymer backbone containing a cationic comonomer.
BACKGROUND OF THE INVENTION
In recent years, interpolymer complexes have received considerable attention in the literature due to their interesting and unique properties. In most instances, these complexes are formed by intimately mixing aqueous solutions containing high-charge density polyelectrolytes possessing opposite charge. When these polymer molecules meet in solution, the interaction between oppositely charged sites will cause the release of their associated counterions forming the complex. The counterions are now free to diffuse into the bulk solution. Normally, phase separation occurs upon prolonged standing in these high-charged density complexes. As a result, these materials have poor rheological properties. In recent work we have found that low-charge interpolymer complexes are soluble and effective in viscosifying aqueous solution systems. More importantly, these complexes possess a substantially higher viscosity than the corresponding individual low-charge density copolymer components. These characteristics are unexpected since high-charge density complexes are insoluble in these conventional solution systems. Therefore, it is anticipated that few detailed rheological studies of these latter materials appear in the literature. In particular, shear rate measurements are markedly absent.
Polymeric materials are useful as viscosity enhancers when dissolved in the appropriate solvent system. The principle reason for this behavior is due primarily to the large volume which a single macromolecular chain can occupy within the solvent. An increase in the size of the chain produces a concomitant enhancement in the solution viscosity. However, when the polymer chain is placed in a shear field, segmental orientation takes place in the direction of the shearing force. The viscosity of the fluid dramatically drops due to this orientation phenomena. Such shear thinning behavior is typical of most solutions containing dissolved polymer materials. However, if the polymer molecule has a very high molecular weight with a relatively flexible backbone and the solvent viscosity is sufficiently high, different behavior can be anticipated. It has been shown by several groups that, with increasing shear rates, the viscosity should show a decrease, followed by a minimum value and a subsequent small increase in cases where both solvent viscosity and polymer molecular weight are very high. This latter effect gives rise to a very mild dilatant behavior. However, the above-mentioned conditions required for the appearance of shear thickening behaviour in these polymeric solution systems are not applicable for many technologically interesting fluids. In most of the common synthetic polymers, it is difficult from a synthetic viewpoint to obtain sufficiently high molecular weight and even when obtained it is easily degraded under shear, in addition, most solvents (for example, water) have rather low viscosities.
This invention discloses the novel and unexpected result that soluble interpolymer complexes of lower molecular weight are capable of enhancing the viscosity of aqueous solutions under relatively broad shear conditions. With these unique polymeric materials, dilatant behaviour occurs in aqueous fluids which are of extreme technological utility. It is further observed that under the identical experimental conditions, the viscosity of the individual copolymer components show the normal shear thinning behavior.
Polymers with very high molecular weight can be used to modify a solvent for a variety of technological applications. In this invention it is disclosed that an alternative to ultra high molecular weight additives are lower molecular weight polymers which are capable of associating in solution, thereby building a network of a very high molecular weight. A way for achieving such networks is the complexation of two dissolves polymers, one having anionic charges along its backbone and the other having cationic charges along its backbone. The complex can be achieved by dissolving each polymer alone in the solvent and combining the two solutions. Alternatively, each polymer can be codissolved in the same solution system. When polymer moleculees of opposite charges meet in solution, an interaction occurs between oppositely charged sites forming a complex which involves the associated counterions that may have been present in one or both polymers. The interaction of the two polymers in solution is not an acid-base neutralization reaction which would occur at a stoichiometric ratio of anionic/cationic polymer of 1/1 but is a formation of a polymer complex.
In order to avoid phase separation of the complex in solution, the charge density along the polymer backbones should be relatively low. The resulting solution of such a complex is then significantly more viscous than solutions containing the individual polymers, provided that the total numbers of negative and positive charges are correctly balanced. Upon addition of a strongly polar agent such as water soluble inorganic salts alcohol the complex can be disturbed and the viscosity reduced.
It was found that for a given balance of the various parameters that may be varied in an interpolymer complex solution, an unexpected shear thickening (dilatant) behaviour may be obtained. These parameters include:
Backbone nature of each of the polymers (or copolymers).
The charge densities along the polymer backbones.
The molecular weight of each polymer.
The ratio between the polymers introduced into solution.
The solvent (and cosolvent, if any).
The concentration of polymer in solution.
As explained above, most solutions of high molecular weight polymers are expected to exhibit a shear thinning behaviour. Interpolymer complexes under narrow conditions seem on the other hand to possess an ability to establish even larger networks or act as if networks are larger under high shear rates resulting in shear thickening.
For example, shear thickening behavior can be useful in affecting antimisting characteristics. Such a solution can behave as a fairly low viscosity fluid at low shear rates. However, the viscosity begins to rise as the shear rate is progressively increased. Accordingly, the solution can more effectively resist breakup into a mist of minute droplets. This is a very desirable attribute in a variety of fluids of technological interest. Another desirable attribute is to be able to reverse (or erase) the above-mentioned antimisting behaviour and render it atomizable. With regard to interpolymer complexes, this is readily achieved through addition of a soluble component capable of weakening or totally disrupting the ionic linkages which hold the complex together. Such a component should be highly polar, soluble in the solution containing the dissolved interpolymer complex and capable of efficiently migrating (and disrupting) to the ionic linkages. Water soluble salts, acids, bases and amines are some possible examples.
SUMMARY OF THE INVENTION
The present invention relates to aqueous solutions having dilatant properties in which the aqueous solution contains a polymer complex which is a water soluble polymer backbone containing an anionic comonomer and a copolymer of a water soluble polymer backbone containing a cationic comonomer.
GENERAL DESCRIPTION OF THE INVENTION
The aqueous solution of the instant invention, which exhibits dilatant properties, is formed by the interaction of a mixture of two different polymers in aqueous solutions. There are a number of copolymers which are suitable for forming the complexes.
A preferred system is comprised of a mixture of (A) copolymers of acrylamide and a neutralized styrene sulfonate where the sulfonate content ranges from about 0.1 weight percent up to about 50 weight percent and (B) copolymers of acrylamide and a quaternary ammonium salt such as methacrylamidopropyltrimethylammonium chloride: ##STR1## wherein the level of ionic monomer again ranges from about 0.1 mole percent to about 50 mole percent.
Alternatively, a preferred system comprises a mixture in an aqueous solution of a sulfonated copolymer and cationic monomer containing copolymer.
The number of ionic groups contained in the individual copolymers of the polymer complex is a critical parameter affecting this invention. The number of ionic groups present in the polymer can be described in a variety of ways such as weight percent, mole percent, number per polymer chain, etc. For most polymer systems of interest in this invention, it is desirable to employ mole percent. For vinyl homopolymers, such as polyacrylamide, the sulfonated analog having a sulfonate content of 1.0 mole percent means that one out of every 100 monomer repeat units in the polymer chain is sulfonated. In the case of copolymers, the same definition applies, except for the purposes of this calculation, the polymer can be considered to be prepared from a hypothetical monomer having an average molecular weight, which is the average of the two monomer components.
A variety of other polymer systems can be employed in this invention with the following constraints. Copolymers (A) and (B) should be based on largely water soluble polymer backbones containing an anionic or cationic comonomer respectively. The nonionic water soluble monomer component of copolymer (A) and (B) is selected from the group consisting of acrylamide, N,N dimethylacrylamide, alkyl substituted acrylamides, n-vinyllactones, methacrylates, vinylpyrolidone, ethylene oxide, vinyl alcohol and methacrylamide and the like wherein acrylamide is preferred. The anionic comonomer of copolymer (A) is selected from the group consisting of styrene sulfonate, vinyl sulfonate, allyl sulfonate, acrylate, 2-sulfoethylmethacrylate acrylic acid, 2-methyl propane sulfonic acid, (methyl)acrylic acid, and the like, wherein the sulfonate groups are neutralized with an ammonium cation or a metal cation selected from the group consisting of Groups IA, IIA, IB and IIB of the Periodic Table of Elements. The cationic comonomer of copolymer (B) is selected from the group consisting of methacrylamidopropyltrimethylammonium chloride, dimethyldiallylammonium chloride, diethyldiallylammonium chloride, 2-methacryloxy-2-ethyltrimethylammonium chloride, trimethylmethacryloxyethylammonium methosulfate, 2-acrylamido-2-methylpropyltrimethylammonium chloride, vinylbenzyltrimethylammonium chloride, and the like. Copolymer (A) or (B) contains about 0.1 to about 50 mole percent of the anionic comonomer, more preferably about 0.5 to about 30 and most preferably about 1 to about 10. The number average molecular weight of copolymer (A), as determined for example by osmotic pressure measurements or gel permeation chromatography, is about 10 4 to about 10 8 , more preferably about 10 5 to about 10 7 , and most preferably about 10 5 to about 10 6 .
Alternatively, the molecular weight, as derived from intrinsic viscosities, for the copolymers of acrylamide/sodium styrene sulfonate (or methacrylamidopropyltrimethylammonium chloride) is about 1×10 4 to about 1×10 8 , more preferably about 1×10 5 to about 1×10 7 and most preferably about 1×10 5 to about 1×10 6 . The means for determining the molecular weights of the water soluble copolymers from the viscosity of solutions of the copolymers comprises the initial isolation of the water soluble copolymers, purification and redissolving the copolymers in water to give solutions with known concentrations at an appropriate salt level (normally sodium chloride). The flow times of the solutions and the pure solvent were measured in a standard Ubbelhode viscometer. Subsequently, the reduced viscosity is calculated through standard methods utilizing these values. Extrapolation to zero polymer concentration leads to the intrinsic viscosity of the polymer solution. The intrinsic viscosity is directly related to the molecular weight through the well-known Mark-Houwink relationship.
Copolymers (A) and (B) are prepared by a free radical copolymerization in an aqueous medium which comprises the steps of forming a reaction solution of acrylamide monomer and sodium styrene sulfonate monomer [or methacrylamidopropyltrimethylammonium chloride monomer (50 wt.% solution in water)] in distilled water, wherein the total monomer concentration is about 1 to about 40 grams of total monomer per 100 grams of water, more preferably about 5 to about 30, and most preferably about 10 to about 20; purging the reaction solution with nitrogen; heating the reaction solution to 50° C. while maintaining the nitrogen purge; adding sufficient free radical initiator to the reaction solution at 50° C. to initiate copolymerization of the acrylamide monomer and sodium styrene sulfonate monomer, (or methacrylamidopropyltrimethyl ammonium chloride monomer); copolymerizing said monomers of acrylamide and sodium styrene sulfonate (or methacrylamidopropyltrimethylammonium chloride) at a sufficient temperature and for a sufficient period of time to form said water soluble copolymer; and recovering said water soluble copolymer from said reaction solution.
Copolymerization of the acrylamide monomer and sodium styrene sulfonate monomer, (or methacrylamidopropyltrimethylammonium chloride monomer) is conducted at a temperature of about 30° to about 90° C., more preferably at about 40 to about 70, and most preferably at about 50 to about 60 for period of time of about 1 to about 24 hours, more preferably about 3 to about 10, and most preferably about 4 to about 8.
A suitable method of recovery of the formed water soluble copolymer from the aqueous reaction solution comprises precipitation in acetone, methanol ethanol and the like.
Suitable free radical initiators for the free radical copolymerization of the acrylamide monomer, and sodium styrene sulfonate monomer, (or the methacrylamidopropyltrimethyl ammonium chloride monomer) are selected from the group consisting of potassium persulfate, ammonium persulfate, benzoyl peroxide, hydrogen peroxide, and azobisisobutyronitrile and the like. The concentration of the free radical initiator is about 0.001 to about 2.0 grams of free radical initiator per 100 grams of total monomer, more preferably about 0.01 to about 1.0 and most preferably about 0.05 to about 0.1.
It should be pointed out that neither the mode of polymerization (solution, suspension, or emulsion polymerization technique and the like), nor the initiation is critical, provided that the method or the products of the initiation step does not inhibit production of the copolymer or chemically modify the initial molecular structure of reacting monomers.
The interpolymer complex of the anionic copolymer and the cationic copolymer is typically formed by forming a first solution of the anionic copolymer in an aqueous solution. A second solution of the cationic copolymer is formed by dissolving the copolymer in an aqueous solution. The concentration of the anionic copolymer in the solution is about 0.001 to about 10.0 g/dl, more preferably about 0.01 to 5.0 g/dl, and most preferably about 0.1 to 4.0 g/dl. The concentration of the cationic copolymer in the second solution is about 0.001 to about 10.0 g/dl, more preferably about 0.01 to 5.0 g/dl, and most preferably about 0.1 to 4.0 g/dl. The first solution of the anionic copolymer and the second solution of the cationic copolymer are mixed together, thereby permitting the interaction of the anionic and cationic copolymers to form a water soluble interpolymer complex. Alternatively, both polymers can be simultaneously codissolved in water. The molar ratio of anionic monomer units in the copolymer to the cationic monomer units in the copolymer in the interpolymer complex is about 0.05 to 20, more preferably about 0.1 to about 10, and most preferably about 0.2 to about 5. The concentration of the interpolymer complex in the aqueous solution is about 0.01 to about 10 g/dl, more preferably about 0.1 to about 7, and most preferably about 0.2 to about 5.
An important characteristic of the materials employed in this invention is the stoichiometry of the ionic species when polymers (A) and (B) are blended together. A wide variation in such stoichiometries has been explored wherein the ratio of anionic/cationic species varies from 20/1 to 1.1/1 and 0.9/1 to 1/20. An even wider range of from 45/1 to 1.1/1 and 0.9/1 to 1/45 for such stoichiometries is believed to be within the scope of this invention.
Accordingly, the preferred ratio of the anionic/cationic can be from about 20/1 to 1.1/1 and about 0.9/1 to 1/20.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following examples illustrate the present invention without; however limiting the same hereto.
EXAMPLE I
Copolymer Synthesis and Complex Preparation
A representative example for the synthesis of the anionically-charged acrylamide-sodium styrene sulfonate (SSS) copolymer is outlined below.
Into a one-liter, 4-necked flask add:
60 mole % acrylamide
40 mole % sodium styrene sulfonate
500 ml. distilled water.
The solution is purged with nitrogen gas for one hour to remove dissolved oxygen. As the nitrogen gas purge began, the solution is heated to 50° C. At this point, 0.05 g potassium persulfate is added to the solution. After 24 hours, the polymer is precipitated from solution with acetone. Subsequently, the resulting polymer is washed several times with a large excess of acetone and dried in a vacuum oven at 60° C. for 24 hours. Elemental analysis shows a sulfur content of 9.13 weight percent, which corresponds to 32.9 mole percent sodium styrene sulfonate.
A representative example for the synthesis of a cationically-charged acrylamide-methacrylamidopropyltrimethylammonium chloride (MAPTAC) copolymer is essentially identical to the previous polymerization, except for the substitution of SSS for an appropriate quantity of MAPTAC, as presented below.
90 mole % acrylamide
10 mole % MAPTAC (50% solution).
The reaction is carried out utilizing the above specifications. Elemental analysis shows a chlorine content of 1.68 weight percent corresponding to 3.7 mole percent MAPTAC.
As is well-known to those versed in the art, the level of ionic monomers incorporated in the growing polymer chain is directly related to the initial concentration of the reacting species. Therefore, modulation of the ionic charge within the polymer structure is accomplished through changes in the initial anionic or cationic vinylic monomer concentration.
The interpolymer complexes were formed by dissolving the appropriate weight of each copolymer into an aqueous solution to the desired polymer level. The solutions are added together and vigorously mixed. The specific overall charge level within this solution is calculated by assuming that a reaction will take place between all unlike charges leaving any residual charge unaffected. This assumption is quite reasonable since low-charge density copolymers are used in this instant invention.
EXAMPLE II
The following table is a typical example of the viscosity-shear rate behavior of an aqueous solution containing an interpolymer complex at 25° C. The complex was prepared so that the solution possessed a residual charge as designated by the ionic monomer molar ratio, i.e., SSS/MAPTAC:1.15/1.0. The polymer concentration was 1 g/dl.
______________________________________Shear Rate (sec.sup.-1) Viscosity (cps)______________________________________ 3.0 3606.0 3109.0 28012.0 27022.0 23030.0 26550.0 29075.0 310105. 260110. 240225. 180250. 160300. 150______________________________________
The data shows that at relatively low shear rates, the viscosity drops as anticipated. However, the viscosity begins to rise at shear rates greater than approximately 22 sec -1 (dilatant behavior). Further enhancement is observed even as the shear rate approaches 100 sec -1 . The individual copolymer components of the complex show a monotonic decrease in viscosity under identical experimental conditions. Therefore, it is readily observed that the soluble low-charge density interpolymer complex is effective as a dilatant fluid in aqueous solutions and, in addition, is an effective viscosifier over a wide shear rate range.
The mechanism for this viscosity enhancement in these solutions is believed to be due primarily to the increase in the apparent molecular weight of the complex through formation of intermolecular ionic linkages. The number of linkages increases through segmental orientation of the complex backbone in the shear field. Furthermore, the breadth of the viscosity enhancement is a direct function of the charge density level, molecular weight of the individual copolymer and the complex concentration. An increase in any of these factors will markedly enhance the viscosity-shear rate profile.
These types of polymeric materials may be useful as a dilatant agent in a variety of well control and workover fluids. Other areas of applications include fire fighting, drag reduction, hydraulic fluids, enhanced oil recovery, antimisting applications and a host of systems containing an aqueous solution.
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The present invention relates to aqueous solutions having dilatant properties in which the aqueous solution contains a polymer complex which is a water soluble polymer backbone containing an anionic comonomer and a copolymer of a water soluble polymer backbone containing a cationic comonomer.
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BACKGROUND OF THE INVENTION
Many molded flexible polyurethane articles contain a structural support attached to or incorporated into them in their finished form. These structural supports are commonly referred to as inserts. These inserts are used, for example, as latches, hinges, and the like used to assemble polyurethane articles for their end use. Common examples of the composition of these inserts are Acrylonitrilebutadiene styrene (ABS), polycarbonate (PC), and ABS/PC alloys and the like. The problem with using polycarbonate inserts with molded flexible polyurethane articles is that in some cases the vapors given off by the polyurethane foam have been found to attack and degrade the polycarbonate causing early failure of the finished end use article.
It has been found that the chemicals in flexible polyunethane foam formulation that were causing the polycarbonate degradation are the tertiary amine catalysts. While the use of tertiary amine catalysts to produce the molded flexible polyurethane is preferred, a system which will not attack and degrade the polycarbonate inserts is needed.
SUMMARY OF INVENTION
The present invention relates to molded flexible polyurethane compositions having an improved polycarbonate compatibility. Polycarbonate compatible molded flexible polyurethane foams are prepared by reacting an organic polyisocyanate with a polyol in the presence of a reactive tertiary amine catalyst. The improvement for producing this improved polycarbonate compatibility comprises employing a catalyst composition comprising only reactive amine catalysts that become part of the polyurethane network.
In another embodiment of the invention molded flexible polyurethane compositions having an improved polycarbonate compatibility are prepared by reacting an organic polyisocyanate with a polyol in the presence of tertiary amine catalysts and amine scavengers, such as phosphate esters.
The use of such catalyst compositions according to the invention for the manufacture of polycarbonate compatible molded flexible polyurethane articles provide the advantage of greatly reducing or eliminating the degradation of the polycarbonate caused by use with said polyurethane articles while retaining the necessary advantageous characteristics of such polyurethane foams for this desired use.
BRIEF DESCRIPTION OF THE INVENTION
This invention may be briefly described as being a molded flexible polyurethane composition having an improved polycarbonate compatibility which comprises an organic polyisocyanate, a polyol, and a reactive tertiary amine catalyst containing at least one active hydrogen and/or hydroxyl group in its structure. It also encompasses a molded flexible polyurethane composition having an improved polycarbonate compatibility which comprises a reacting an organic polyisocyanate, a polyol, a non-reactive tertiary amine catalyst, and an effective amount of a composition which acts as an amine scavenger. The invention also encompasses a process for producing a molded flexible polyurethane composition having an improved polycarbonate insert compatibility which comprises reacting an isocyanate and a polyol in the presence of a reactive tertiary amine catalyst containing at least one active hydrogen and/or hydroxyl group in its structure within a mold or in the alternative reacting an isocyanate and a polyol in the presence of a non-reactive tertiary amine catalyst and a composition which acts as an amine scavenger in a mold and thereby producing said polycarbonate compatibility and proved molded flexible polyurethane composition.
DETAILED DESCRIPTION OF THE INVENTION
The amine catalysts of this invention comprise reactive tertiary amine catalysts. As used herein reactive tertiary amine catalysts are those tertiary amines containing at least one active hydrogen and/or hydroxyl group in its structure. Preferred, are linear tertiary amines containing at least one active hydrogen and/or hydroxyl group in its structure. Said catalysts being generally used in amounts of from about 0.1 weight percent to about 2.8 weight percent, preferably from about 0.3 weight percent to about 1.3 weight percent of the total composition. Examples suitable reactive tertiary amine catalysts include, for example, (CH 3 ) 2 N(CH 2 ) 3 NH 2 and (CH 3 ) 2 NCH 2 CH 2 OH. These cataylsts are available commercially from supplies such as Texaco Chemical Co., Air Products and Chemicals, Inc. and others well know in the art.
In another embodiment of the invention fugitive tertiary amine catalysts may be used, alone or in combination with reactive tertiary, in conjunction with amine scavengers, such as, for example, phosphate esters. Suitable phosphate esters include, for example, trischloroethylphosphate, tricresylphosphate, ammonium phosphate and ammonium polyphosphate. These amine scavengers are used in amounts which effectively tie up the unreacted non-reactive amine catalysts. These amine scavengers are generally used in an effective amount to provide the desired effect and range from about a 2:1 ratio to about a 10:1 ratio with said non-reactive tertiary amine catalysts. These phosphate esters are well known and available commercially from companies such as Akzo Chemie America.
The polyisocyanates useful as starting components for the production of such resins using the novel catalyst system according to the present invention may be any aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic polyisocyanates, such as those described, for example, by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136. These include, for example, ethylene diisocyanate; tetramethylene-1,4-diisocyanate; hexamethylene-1,6-diisocyanate; dodecane-1,2-diisocyanate; cyclobutane-1,3diisocyanate; cyclohexane-1,3- and 1,4diisocyanate and mixtures of these isomers; 1-isocyanato-3,3,5-trimethyl-5ioscyanatomethylcyclohexane (U.S. Pat. No. 3,401,190); hexahydrotolylene-2,4- and -2,6-diisocyanate and mixtures of these isomers; hexahydrophenylene-1,3- and/or 4,4,diisocyanate; phenylene-1,3- and -1,4-diisocyanate; tolylene-2,4- and -2,6-diisocyanate and mixtures, of these isomers; diphenylmethane-2,4- and/or 4,4 -diisocyanate; naphthylene-1,5-diisocyanate; triphenylmethane-4,4 ,4 triisocyanate; polyphenyl-polymethylene polyisocyanate which may be obtained by aniline/formaldehyde condensation followed by phosgenation and which have been described, for example, in British Pat. Nos. 874,430 and 848,671; m- and p-isocyanato-phenylsulphonylisocyanates according to U.S. Pat. No. 3,454,606; perchlorinated aryl polyisocyanates as described, e.g. in U.S. Pat. No. 3,277,138; polyisocyanates containing carbodiimide groups as described in U.S. Pat. No. 3,152,162; the diisocyanates described in U.S. Pat. No.3,492,330; polyisocyanates containing allophanate groups as described, e.g.: in British Pat. No. 994,890, Belgian Pat. No. 76I,626 and published Dutch Patent Application 7,102,524; polyisocyanates containing isocyanurate groups as described, e.g. in U.S. Pat. No. 3,001,973, in German Pat. Nos. 1,022,789; 1,222,067 and 1,027,394 and in German Offenlegungsschriften Nos. 1,929,034 and 2,004, 048; polyisocyanates containing urethane groups as described, e.g. in Belgian Pat. No. 752,261 or in U.S. Pat. No. 3,394,164; polyisocyanates containing acylated urea groups according to German Pat. No. I,230,778; polyisocyanates containing biuret groups as described, e.g. in German Pat. No. 1,101,394 (U.S. pat. Nos. 3,124,605 and 3,201,372) and in British Pat. No. 889,050; polyisocyanates prepared by telomerization reactions as described, e.g. in U.S. Pat. No. 3,654,106; polyisocyanates containing ester groups as mentioned, for example, in British Pat. Nos. 965,474 and I,072,956, in U.S. Pat. No. 3,567,763 and in German Pat. No. 1,231,688; reaction products of the above-mentioned isocyanates with acetals according to German Pat. No. 1,072,385; and polyisocyanates containing polymeric fatty acid groups according to U.S. Pat. No. 3,455,883.
The distillation residues obtained from the commercial production of isocyanates which still contain isocyanate groups may also be used, optionally dissolved in one or more of the above-mentioned polyisocyanates. Mixtures of the above-mentioned polyisocyanates may also be used.
The commercially readily available polyisocyanates are generally preferred. These include, for example, tolylene2,4- and -2,6-diisocyanate and mixtures of these isomers ("TDI"); polyphenylpolymethylene polyisocyanates, which may be obtained by aniline/formaldehyde condensation followed by phosgenation ("crude MDI"); and polyisocyanates containing carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, urea groups or biuret groups ("modified polyisocyanates⃡).
The amount of isocyanate used in a given formulation is dependent on the amount of water in the formulation as well as the choice of polyols and isocyanates and the index used to process the foam. All of this is well understood in the art and requires no undo experimentation to understand and use Applicants' invention.
The starting components used for the production of isocyanate polyaddition resins with the aid of the novel catalyst systems according to the present invention also include compounds which contain at least two hydrogen atoms capable of reacting with isocyanates and which generally have a molecular weight of from about 400 to about 10,000. These may be compounds containing amino groups, thiol groups or carboxyl groups, but are preferably polyhydroxyl compounds, and in particular compounds having from 2 to 8 hydroxyl groups and especially those having a molecular weight of from 800 to 10,000 and preferably from 1000 to 7000. These include, for example, polyesters, polyethers, polythioethers, polyacetals, polycarbonates and polyester amides containing at least 2, generally from 2 to 8 and preferably from 2 to 4 hydroxyl groups, such as those known for the production of both homogeneous and cellular polyurethanes.
The hydroxyl group-containing polyesters used may be, for example, reaction products of polyhydric, preferably dihydric alcohols, optionally with the addition of trihydric alcohols, and polybasic, preferably dibasic carboxylic acids. Instead of using the free polycarboxylic acids, the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols or mixtures thereof may be used for preparing the polyesters. The polycarboxylic acids may be aliphatic, cycloaliphatic, aromatic and/or heterocyclic and they may be substituted, e.g. with halogen atoms, and/or be unsaturated. The following are mentioned as examples: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic acid anhydride, endomethylene tetrahydrophthalic acid anhydride, glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, dimeric and trimeric fatty acids, such as oleic acid, optionally mixed with monomeric fatty acids, dimethyltere phthalate and terephthalic acid-bis-glycol esters. Suitable polyhydric alcohols include, e.g. ethylene glycol; propylene glycol-(1,2) and -(1,3); butylene glycol(1,4) and -(2,3); hexanediol (1,6); octanediol-(1,8); neopentyl glycol; cyclohexane dimethanol (1,4-bishydroxymethylcyclohexane); 2-methyl-1,3-propanediol; glycerol; trimethylolpropane; hexanetriol-(1,2,6); butanetriol-(1,2,4); trimethylolethane; pentaerythritol; guinitol; mannitol and sorbitol; methylglycoside; diethylene glycol; trethylene glycol; tetraethylene glycol; polyethylene glycols; dipropylene glycol; polypropylene glycols; dibutylene glycol and polybutylene glycols. The polyesters may also contain carboxyl end groups. Polyesters of lactones, such as e-caprolactone, and hydroxycarboxylic acids, such as w-hydroxycaproic acid, may also be used.
The polyethers used according to the present invention which contain at least 2, generally from 2 to 8 and preferably 2 or 3 hydroxyl groups are known. They may be prepared, for example, by the polymerization of epoxides, such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin, either each on its own, (e.g. in the presence of BF3), or by chemical addition of these epoxides, optionally as mixtures or successively, to starting components having reactive hydrogen atoms, such as water, alcohols or amines, e.g. ethylene glycol,,propylene glycol-(1,3) or - 1,2), trimethylol propane, 4,4 dihydroxydiphenylpropane, aniline, ammonia, ethanolamine or ethylenediamine. Sucrose polyethers which have been described, for example in German Auslegeschriften Nos. 1,176,358 and 1,064,938 may also be used according to the present invention. It is frequently preferred to use polyethers which contain predominantly primary OH groups (up to 90%, by weight, based on all the OH groups present in the polyether. Polyethers which have been modified with vinyl polymers, for example the compounds obtained by the polymerization of styrene and acrylonitrile in the presence of polyethers (U.S. Pat. Nos. 3,383,351; 3,304,273; 3,523,093 and 3,110,695 and German Pat. No. 1,152,536) are also suitable. Polybutadienes containing OH groups may also be used.
Among the polythioethers which should be particularly mentioned are the condensation products obtained from thiodiglycol on its own and/or with other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids or amino alcohols. The products obtained are polythio mixed ethers, polythio ether esters or polythioether ester amides, depending on the co-components.
Suitable polyacetals include, e.g. the compounds which may be obtained from glycols,, such as diethylene glycol, triethylene glycol, 4,4 -dioxethoxy-diphenyldimethylmethane or hexanediol, and formaldehyde. Polyacetals suitable for the purpose of the present invention may also be prepared by polymerizing cyclic acetals.
Suitable polycarbonates containing hydroxyl groups are known and may be prepared, for example, by the reaction of diols, such as propanediol-(1,3), butanediol-(1,4) and/or hexanediol-(1,6), diethylene glycol, triethylene glycol or tetraethyleneglycol, with diarylcarbonates, e.g. diphenyl carbonate, or phosgene.
Suitable polyester amides and polyamides include, e.g. the predominantly linear condensates obtainable from polybasic saturated and unsaturated carboxylic acids or their anhydrides and polyvalent saturated and unsaturated amino alcohols, diamines, polyamines or mixtures thereof.
Polyhydroxyl compounds already containing urethane or urea groups as well as modified or unmodified natural polyols, such as castor oil, carbohydrates or starch may also be used. Additionally, products of alkylene oxides and phenol/formaldehyde resins or of alkylene oxides and urea/formaldehyde resins are also suitable according to the present invention.
Representatives of these compounds which may be used according to the present invention have been described, e.g. in High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology:, by Saunders-Frisch, Interscience Publishers, New York, London, Volume I, 1962, pages 32-42 and pages 4454 and Volume II, 1964, pages 5-6 and 198-199 and in Kunststoff-Handbuch, Volume VII, Vieweg-Hochtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 45 to 71.
Mixtures of the above-mentioned compounds containing at least two hydrogen atoms capable of reaction with isocyanates and having a molecular weight of from about 400 to about 10,000 may, of course, also be used, e.g. mixtures of polyethers and polyesters.
The starting components used according to the present invention optionally also include compounds having a molecular weight of from 32 to about 400 which contain at least two hydrogen atoms capable of reacting with isocyanates. These are also compounds containing hydroxyl groups and/or amino groups and/or thiol groups and/or carboxyl groups, preferably compounds containing hydroxyl groups and/or amino groups. They serve as chain lengthening agents or cross-linking agents. They generally contain from 2 to 8 hydrogen atoms capable of reacting with isocyanates, preferably 2 or 3 such hydrogen atoms. The following are mentioned as examples of such compounds; ethylene glycol; propylene glycol-(1,2) and -(1,3); butylene glycol-(1,4) and -(2,3); pentanediol-(1,5); hexanediol-(1,6); octanediol-(1,8); neopentylglycol; 1,4-bis-hydroxymethylcyclohexane; 2-methyl-1,3-propanediol; glycerol; trimethylolpropane; hexanetriol-(1,2,6); trimethylolethane; pentaerythritol; quinitol; mannitol and sorbitol; diethylene glycol; triethylene glycol; tetraethylene glycol; polyethylene glycols having a molecular weight of up to 400; dipropylene glycol, polypropylene glycols having a molecular weight of up to 400; dibutylene glycol; polybuty,lene glycols having a molecular weight of up to 400; 4,4 -dihydroxydiphenylpropane; dihydroxymethylhydroquinone; ethanolamine; diethanolamine; triethanolamine; 3-aminopropanol; ethylenediamine; 1,3-diaminopropane; 1-mercapto-3aminopropane; 4-hydroxyphthalic acid or 4-aminophthalic, acid; succinic acid; adipic, acid; hydrazine; N,N dimethylhydrazine and 4,4 -diaminodiphenylmethane.
Here again, mixtures of various compounds having a molecular weight of from 32 to 400 and containing at least two hydrogen atoms capable of reacting with isocyanate may be used.
Production of the isocyanate polyaddition resins with the aid of the novel catalyst systems according to the present invention is frequently carried out with the use of water and/or readily volatile organic substances as blowing agents. Suitable organic blowing agents include, e.g. acetone; ethyl acetate; halogenated alkanes, such as methylene chloride, chloroform, ethylidene chloride, vinylidene chloride, monofluorotrichloromethane, chlorodifluoromethane or dichlorodifluoromethane, butane; hexane; heptane or diethylether. The effect of a blowing agent may also be obtained by adding compounds which decompose at temperatures above room temperature to liberate gases, such as nitrogen, e.g. azo compounds, such as azoisobutyric acid nitrile. Other examples of blowing agents and details about the use of blowing agents may be found in Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 108 and 109, 453 to 455 and 507 to 510.
Other known catalysts may, of course, be used in addition to the catalyst combinations according to the present invention, particularly if particular effects may hereby be obtained.
Silaamines having carbon-silicon bonds as described, e.g. U.S. Pat. No. 3,620,984 may also be used as additional catalysts, for example, 2,2,4-trimethyl-2-silamorpholine and 1,3-diethylaminomethyltetramethyldisiloxane. Production of the polyurethane resins with the aid of the new catalyst combinations according to the present invention may also be carried out with the addition of surface active agents (emulsifiers and/or foam stabilizers).
Suitable emulsifiers include, e.g., the sodium salts of ricinoleic sulphonates or salts of fatty acids and amines, such as oleic acid diethylamine or stearic acid diethanolamine. Alkali metal or ammonium salts of sulphonic acids, such as dodecylbenzene sulphonic acid or dinaphthylmethane disulphonic acid, or of fatty acids, such as ricinoleic acid, or of polymeric fatty acids may also be used as surface active additives.
The foam stabilizers used are mainly polyether siloxanes, especially those which are water-soluble. These compounds generally have a polydimethylsiloxane group attached to a copolymer of ethylene oxide and propylene oxide. Foam stabilizers of this type have been described, for example, in U.S. Pat. Nos. 2,834,748; 2,197,480 and 3,629,308.
According to the present invention reaction retarders may also be added e.g. compounds which are acid in reaction, such as hydrochloric acid or organic acid halides. Known cell regulators, such as paraffins or fatty alcohols or dimethylpolysiloxanes; pigments; dyes; known flame retarding agents, such as trischloroethylphosphate, tricresylphosphate or ammonium phosphate or polyphosphate; stabilizers against aging and weathering; plasticizers; fungistatic and bacteriostatic substances; and fillers, such as barium sulphate, kieselguhr; carbon black or whiting may also be used.
Other examples of surface active additives, foam stabilizers, cell regulators, reaction retarders, stabilizers, flame retarding substances, plasticizers, dyes, fillers and fungistatic and bacteriostatic substances which may also be used according to the present invention and details concerning the use and action of these additives may be found in Kunststoff-Handbuch, Volume VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 103 to 113.
The various amounts of materials, aside from the catalyst system itself, is dependent upon the ultimate product desired, and may, accordingly, be varied widely in manners know and used in the art.
According to the present invention, the components are reacted together by the known one-shot process, in many cases using mechanical devices, such as those described in U.S. Pat. No. 2,764,565. Details about processing apparatus which may also be used according to the present invention may be found in Kunststoff Handbuch, Volume VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich, 1966, e.g. on pages 121 to 205. As is known in the art, in a one-shot process, either all the components (both reactive and non-reactive) are mixed at one time, or the non-isocyanate reactive components are first mixed with the active hydrogen containing materials and the resultant pre-mix is then mixed with the isocyanate component.
For producing foams according to the present invention, the foaming reaction may be carried out inside molds. The reaction mixture is introduced into a mold made of a metal, such as aluminum, or of a synthetic material, such as an epoxide resin. The reaction mixture foams inside the mold to form the shaped product. This process of foaming in molds may be carried out to produce a product having a cellular structure on its surface or it may be carried out to produce a product having a non-cellular skin and cellular center. According to the present invention, the desired result may be obtained by either introducing just sufficient foamable reaction mixture into the molds to fill the mold with foam after the reaction or introducing a larger quantity of foamable reaction mixture, in which case the process is said to be carried out under conditions of overcharging, a procedure which has already been disclosed, for example, in U.S. Pat. Nos. 1,178,490 and 3 182,104.
When foaming is carried out in molds, so-called "external mold release agents" such as silicone oils, are frequently used, but so-called "internal mold release agents" may also be used, optionally in combination with external mold release agents, for example those disclosed in German Offenlegungsschriften Nos. 2,121,670 and 2,307,589.
Cold setting foams may also be produced according to the present invention (see British Pat. No. 1,162,517, German Offenlegungsschrift No. 2,153,086).
On the other hand, foams may, of course, be produced by the process of block foaming or by the known laminator process.
The following Examples serve to illustrate the invention. The figures quoted represent parts by weight or percentages by weight unless otherwise indicated.
EXAMPLE I
Isocyanate
______________________________________Lupranate ® M20S Polymeric MDI 55.0%Lupranate ® MS Pure MDI 25.0%Lupranate ® MI Pure MDI 20.0% 100.0%______________________________________ Free NCO = 32.4%
Resin
______________________________________WUC-32380-R 98.9%a resin blend availablefrom BASF Corp.Catalyst* 1.10% 100.00%______________________________________ *The particular catalyst for each sample is given in Table.
Using this combination of resin and isocyanate and using conventional polyurethane production processes, foam blocks measuring 12"×12"×1" were molded to a density of 5.5 to 6.0 pounds per cubic foot. These molded foams were demolded to 5 minutes after being poured. Within one hour of demolding, the blocks were diced into small pieces (approx. 1"×1" in size). 100 grams of the diced foam of each sample was placed in separate 2-quart mason jars. A piece of injection molded Lexan® 141 polycarbonate, available from General Electric, having approximate dimension of 2"L×1" W×1/4" H was placed in each jar and the jars were sealed. The jars were placed in a convection oven at 180° F. until failure of the polycarbonate was observed.
Failure of the polycarbonate was defined as, a change in the appearance of the surface of the polycarbonate. The most common failure involved the surface of the polycarbonate becoming glossy, with the formation of small droplets also occurring. Another type of failure observed was the whitening of the surface of the polycarbonate. In all cases, the strength of the polycarbonate was lowered.
For each sample, the time from start of oven heating until the polycarbonate failed was recorded. The results are shown in Table I.
The results clearly show that the samples (1-9) using reactive amine catalysts in the absence of non-reactive amine catalysts have superior compatibility with polycarbonate inserts over those using only non-reactive amine catalysts (samples 10-17).
EXAMPLE II
Using the same isocyanate and resin and following the same procedure as in Example I, the following eight samples were produced and tested as per Example I to show the advantageous effect of amine scavengers with non-reactive amines. These results clearly illustrate the advantageous effects of using amine scavengers in conjunction with non-reactive amines. In reactive amine systems some additional positive effect is also realized using the amine scavengers in Samples 2-3 but a determental effect occurred in Example 4. No such corresponding determental effect was found with this amine scavenger and non-reactive amines.
TABLE I__________________________________________________________________________ZF-10 0.4 0.4 0.4 -- -- -- -- -- --ZR-70 0.7 -- -- -- -- 0.7 0.7 -- --PC-17 -- 0.7 -- -- 0.7 -- -- 0.7 --PC-15 -- -- 0.7 0.7 -- -- -- -- 0.7DMEA -- -- -- 0.4 0.4 0.4 -- -- --Dabco T -- -- -- -- -- -- 0.4 0.4 0.4A-1 0.4 0.4 0.4 0.4 0.4 -- -- --33LV 0.7 -- -- -- -- -- -- --PC-8 -- 0.7 -- -- -- -- -- 0.7DMP -- -- 0.7 -- -- -- -- --XDM -- -- -- 0.7 -- -- 0.7 --TEA -- -- -- -- -- 0.4 0.4 0.4PC-9 -- -- -- -- 0.7 0.7 -- --Index 95 → → → → → → → → → → → → → → → →Time to FailDays 5 5 6 10 5 5 5 5 5 0 2 2 2 2 2 2 2Hours 17 0 16 16 0 17 17 0 17 14 23 6 6 3 18 6 6__________________________________________________________________________
TABLE II______________________________________REACTIVE CATALYSTS vs NON-REACTIVECATALYSTS IN THE PRESENCEOF AMINE SCAVENGERS 1 2 3 4 5 6 7 8______________________________________ZF-10 0.4 0.4 0.4 0.4 -- -- -- --ZR-70 0.7 0.7 0.7 0.7 -- -- -- --A-1 -- -- -- -- 0.4 0.4 0.4POLYCAT 9 -- -- -- -- 0.7 0.7 0.7 0.7FRYOL CEF -- 2.9 -- -- -- -- -- 2.9FRYOL -- -- 2.9 -- -- -- 2.9 --DMMPTHERMOLIN -- -- -- 2.9 -- 2.9 -- --101TOTAL PBW 100 102.9 → → 100 10.29 → →IN RESINBLENDINDEX 100 → → → → → → →DAYS TO 12 15 19 6 11 21 21 15FAILURE______________________________________
Although the invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that such detail is solely for that purpose and that variations can be made therein by those skilled in the art without departing from the spirit and scope of the invention except as it may be limited by the claims.
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A molded flexible polyurethane composition having improved polycarbonate compatibility comprising an organic polyisocyanate, a polyol and reactive tertiary amine catalyst. This catalyst contains at least one active hydrogen and/or hydroxyl group in its structure. Another embodiment of this invention relates to a molded flexible polyurethane composition having improved polycarbonate compatibility comprising an organic polyisocyanate, a polyol, a non-reactive tertiary amine catalyst and, an amine scavenger composition which may or may not also contain reactive tertiary amine catalysts. Also disclosed are processes for making said molded flexible polyurethane compositions having improved polycarbonate compatibility.
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FIELD OF THE INVENTION
The present invention relates to a method for selective hydrogenation of acetylene to ethylene.
BACKGROUND ART
The hydrogenation of acetylene in industrial scale is typically used for purification of ethylene produced by ethane stream cracking from small amounts (0.5-0.9 mol-%) of acetylene.
U.S. Pat. No. 4,585,897 discloses a process for hydration and condensation of acetylene in a crude acetylene stream containing water in the presence of a zirconia-alumina catalyst containing water.
U.S. Pat. No. 2,723,299 discloses a process for preparing styrene and benzene by heating a mixture of acetylene and monovinyl acetylene to a specific temperature under a specific pressure in the presence of a nickel-based catalyst.
U.S. Pat. No. 4,009,219 discloses a process of producing benzene wherein lithium carbide which has been produced is hydrolysed to produce acetylene which is subsequently cyclysized to produce benzene.
Further, U.S. Pat. No. 4,982,032 discloses a process for the conversion of a wet acetylene-containing stream to a product rich in the aromatics benzene, toluene and xylene, wherein the acetylene-containing stream is contacted with a promoted catalyst composition comprising a minor amount of zinc ion incorporated in a major amount of a borosilicate molecular sieve composited in an inorganic matrix.
U.S. Pat. No. 4,227,025 discloses a process for the effective removal of acetylene from a first gas feed which comprises feeding said gas together with hydrogen at an acetylene removal temperature in contact with a noble metal hydrogenation catalyst.
U.S. Pat. No. 4,227,025 discloses in detail the hydrogenation of acetylene in ethylene-containing mixture for purification of ethylene from about 2.200 ppm of acetylene in the presence of a catalyst of Pd supported on Al 2 O 3 .
Further, U.S. Pat. No. 4,128,595 discloses a process for the selective hydrogenation of acetylenic compounds in the liquid phase which comprises contacting hydrogen and a gaseous hydrocarbon stream containing acetylene with a supported catalyst comprising a group VIII metal under hydrogenation conditions.
Up to now, Pd based industrial catalysts on a support can operate only at low concentrations of acetylene (0.5-0.9 mol-%), and even at these concentrations the catalyst deactivates because of the formation of heavy hydrocarbons, which are called green oil. Therefore, for such processes deep hydrogenation reactions are characteristic, which lead to the loss of ethylene.
The typical gas compositions from methane pyrolysis step contain 8-10 wt.-% acetylene, and the existing catalyst systems cannot work in the presence of this amount of acetylene due to the very fast deactivation of the catalyst by formation of coke fragments. Therefore, traditional catalytic acetylene hydrogenation has the following disadvantages:
Acetylene hydrogenation to ethylene is used only for purification of ethylene from small amounts of acetylene. These methods cannot be used for hydrogenation of high amounts of acetylene for production of ethylene. Traditional processes of gas phase purification of ethylene from acetylene hydrogenation lead to the loss of some ethylene because of low selectivity of these catalysts. During traditional gas phase acetylene hydrogenation on Pd-based catalysts the formation of green oil on the surface of catalysts takes place leading to the deactivation of the catalyst. The traditional gas phase hydrogenation processes are limited with regard to the ratio of hydrogen to acetylene which has to be controlled specifically for keeping a high selectivity of ethylene. The traditional gas phase hydrogenation processes require the specific control of the reaction temperature, run away of the temperature leads to a sharp decrease of selectivity. Further, traditional gas phase hydrogenation processes require the specific control of the amount of carbon monoxide in the feed; without the addition of carbon monoxide the selectivity of ethylene is low, whereas at high concentrations of carbon monoxide, for example more than about 1.200 ppm, the conversion of acetylene decreases almost to zero due to the strong adsorption of carbon monoxide.
Due to these problems, it is very difficult to realize the hydrogenation of acetylene at high concentrations for production of ethylene from acetylene.
U.S. Pat. No. 5,118,893 discloses a catalytic conversion of acetylene in the presence of nickel or cobalt-containing zeolite catalyst with the addition of hydrogen to the acetylene feed. It was observed that acetylene conversion in the presence of zeolite-containing catalyst leads to the rapid deactivation of catalyst due to very fast polymerization of acetylene on the surface of the catalyst.
It was reported that with the increase of acetylene concentration in the mixture deactivation of catalyst proceeds very fast.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method for selective hydrogenation of acetylene to ethylene which overcomes the drawbacks of the prior art, especially to provide a method which enables the production of ethylene with high conversion of acetylene and high selectivity of ethylene, utilizing increased acetylene concentrations in the feed.
This object is achieved by a method for selective hydrogenation of acetylene to ethylene, comprising the steps of: i) introducing a feed comprising acetylene and hydrogen into a reactor containing a supported catalyst, wherein the reactor is a fixed bed reactor containing the supported catalyst additionally diluted with a solid diluent, or the reactor being a wash coated reactor wherein the supported catalyst is coated on reactor walls; and ii) hydrogenating of acetylene to ethylene in the presence of the supported catalyst.
Preferably, the catalyst is selected from group VIII of the periodic system of elements, preferably palladium.
Moreover the feed may be obtained from thermal pyrolysis of methane.
In one embodiment, the amount of acetylene in the feed is from about 0.1 to about 20 wt.-%, preferably from about 8 to about 20 wt.-%, preferably from about 10 to about 15 wt.-%, based on the total weight of the feed.
Preferably, the method is carried out at a temperature of about 30 to about 500° C., preferably about 40 to about 230° C.
Conveniently, the method is carried out at a space velocity of about 1.000 to about 2.000.000 h −1 , preferably about 2.500-170.000 −1 .
Preferably, the support is SiO 2 , ZrO 2 , Al 2 O 3 , TiO 2 , or a mixture thereof.
More preferably, the diluent is SiO 2 , ZrO 2 , Al 2 O 3 , TiO 2 or a mixture thereof.
Most preferably, the molar ratio of hydrogen to acetylene in the feed is from about 5 to about 10, preferably from about 6 to about 7.
The feed may additionally comprise methane, carbon monoxide, nitrogen, carbon dioxide, water, or liquid hydrocarbons, or mixtures thereof.
In one embodiment, the reactor is a quartz, ceramic or metallic reactor.
Preferably, the reactor wall comprises metal gauze or metal mesh. Then, any shape can be used for that gauze or mesh, also resulting in a high surface area.
The flow rate of the feed may be from about 100 to about 1.000 cm 3 /min.
Preferably, the molar ratio of support to catalyst is from about 80 to about 1.000, more preferably from about 90 to about 200 and the particle size of the supported catalyst is from about 45 to about 60 mesh.
Even preferred, the method is carried out in gas or liquid phase and may be carried out under isothermal or non-isothermal conditions and a pressure of about 1 to about 25 bar.
More preferred, the supported catalyst is additionally modified with one of the elements selected from the group consisting of Cu, Co, Cr, K, Pt, Ru, Au, Ag or mixtures thereof.
In one embodiment, the supported catalyst has been reduced with hydrogen for 1-48, preferably 2-20 hours, prior to employment.
Further, the internal diameter of the reactor may be from about 4 to about 45 mm, preferably from about 4 to about 25 mm.
Finally, it is preferred that the weight ratio of diluent to supported catalyst is from about 200 to about 1, preferably from about 50 to about 170.
Surprisingly, it was found that with the method of the present invention acetylene may be converted into ethylene at high concentrations with high conversion and high selectivity. In detail, acetylene concentrations of more than about 10 wt.-% may be utilized. A feed-containing acetylene concentration of about 10 wt.-% may be obtained from thermal pyrolysis of methane. The yield of ethylene in the inventive method is very high, about 80%.
It was found that it is difficult with the traditional fixed bed catalyst to keep high selectivity of ethylene due to the high exothermity of the reaction and runaway of the temperature inside of the catalyst bed. Therefore, the present invention utilizes a specific loading of the catalyst in the reaction zone and a specific shape design of the catalyst which eliminates the dehydrogenation of ethylene to ethane through effective way of heat transfer. This is achieved by the first alternative of the inventive process, wherein a supported catalyst is used in a fixed bed reactor wherein the supported catalyst is additionally diluted with a solid diluent. Further, this is achieved by the second alternative of the inventive method wherein the reactor has been wash coated and the supported catalyst is coated on reactor walls. In the first alternative, the dilution contributes to the dissipation of the reaction heat in long diluted catalyst beds. In the approach with the wash coated reactor, it is quite easy to remove the heat produced during the reaction on the reactor wall.
Further, it was surprisingly found that the acetylene hydrogenation catalyst should have a low concentration of catalyst on the support which is necessary for high selectivity. For the supported catalyst used in the inventive method it was found that palladium supported on TiO 2 was most effective.
Palladium dispersed in such a diluted catalyst system allows to produce a stable catalyst with complete conversion of acetylene at high ethylene selectivity.
The supported catalyst used in the inventive method may be prepared according to any method of catalyst deposition on a support, such as chemical vapor deposition, coating with traditional impregnation methods, deposition by electrochemical methods, such as a method of electrophoresis deposition.
The inventive method may be carried out at very high ratios of hydrogen to acetylene without consecutive ethylene conversion reactions and selectivity decrease. In the inventive method no formation of a green oil and oligomer productions because of the specific reaction performance is observed.
One further advantage of the inventive method is the high selectivity for ethylene over the relatively wide temperature range and high selectivity over a wide range of acetylene conversion and concentration. It is assumed that the inventive method realizes an easy desorption of ethylene from the catalyst surface.
Additionally, a preferred parameter to improve the selectivity and catalyst stability is the temperature of the catalyst pretreatment with hydrogen. Preferably, the catalyst is reduced with hydrogen in isothermal or non-isothermal condition in a temperature range of 150-500° C. with a pretreatment duration of 1-24 hours.
Further, the heat release from the reaction zone can be easily achieved by the inventive method. Especially, in the case of high space velocity conditions there is effective recovery of the reaction heat and an effective dissipation through the catalyst bed is achieved.
Due to the high ratio of hydrogen to acetylene it is assumed that the formation of green oil and heavy hydrocarbons will be very low.
The productivity of the inventive method can be increased even to 2.000.000 cm 3 /g.h, which is significantly increased compared to the productivities given in the literature.
The hydrogenation is carried out without accumulation of coke fragments.
The effect of carbon monoxide to catalyst activity is not significant for the inventive method.
The contact time in the inventive method can be the same as in short residence time pyrolysis process which make the integration of these processes possible, that is as a result a process for conversion of methane to ethylene via pyrolysis of methane to acetylene, followed by hydrogenation of acetylene to ethylene.
Additional advantages and features of the present invention will become apparent from the following examples section, which examples are not considered to limit the scope of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Experimental
Catalyst Preparation
The necessary amount of support, such as TiO 2 , SiO 2 , has been prepared in the form of a gel or a dense suspension. The support was then promoted by palladium by ion adsorption method, from organic or inorganic salts, such as Pd(NO 3 ) 2 or PdCl 2 , or compositions, such as Pd(NH 3 ) 4 (OH) 2 . The supported catalyst was dried at 120° C. and was then crushed to a particle size of 40-60 mesh and was, if desired, diluted with quartz particles of the same size and was finally reduced by hydrogen for one hour before the reaction.
The thus obtained diluted and supported catalyst was used in a fixed bed reactor. On the other hand, the supported (and undiluted) catalyst was utilized to prepare the wash coated reactor as follows:
The internal reactor walls, having, e.g., an internal diameter of ¼ or ⅛ inch were washed three times from top to the bottom of the reactor inside a hot furnace at 250° C. with a suspension of TiO 2 . The concentration of TiO 2 in the suspension was about 2% by weight. After drying, the reactor was then washed three times with a solution of Pd(NO 3 ) 2 . The amount of palladium relative to TiO 2 was about 0.8% by weight.
An EM analysis showed the presence of Ti on the wall with 10% relative to the internal wall surface. Palladium could not be detected due to the low concentration thereof. The reactor was, after washing, treated with hydrogen at 400° C. for one hour, before the hydrogenation process was started.
The reaction conditions and process parameters are illustrated in the following examples.
Example 1
A method according to the present invention was carried out in a metallic reactor having an internal diameter of 4 mm using a mixture of 10% C 2 H 2 +20% CH 4 +60% H 2 and 10% CO 2 . The catalyst provided in the reactor has been treated with hydrogen at 350° C. for 2 hours and then the mixture was fed into the reactor with a flow rate of 120 cm 3 /min at a temperature of 230° C. The reactor was kept at non-isothermal conditions and had a temperature profile of 230° C. at the inlet side and 90° C. at the outlet side of the reactor. The pressure in the reactor was atmospheric.
After reduction of the catalyst with hydrogen at 350° C., at this temperature full conversion of acetylene was observed, but selectivity to ethane was very high. Cooling of the reactor to 60° C. increased the selectivity to ethylene and even at this low temperature full conversion of acetylene was observed. To achieve high stable selectivity to ethylene with very high conversion of acetylene, the temperature of the reactor was kept in the range of 150-198° C. The reaction products of acetylene hydrogenation are C 2 H 4 , C 2 H 6 and CH 4 .
The following table 1 illustrates the process parameters obtained in metallic reactor with 4 mm I.D. All data shown in the following tables are given in mol-%.
In example 1, the conversion of acetylene in catalyst assisted 4 mm I.D. metallic wash coated reactor in the presence of carbon dioxide is shown; flow rate: 120 cm 3 /min; feed composition: 10% C 2 H 2 +60% H 2 +20% C 4 +10% CO 2 ; temperature: 198° C.
TABLE 1
Time, Hours
6
21
44
74
C 2 H 2 conversion, %
97.0
95.2
93.0
90.3
C2H4 concentr. in Outlet gas, %
8.7
8.6
8.5
8.5
C 2 H 4 selectivity, %
84.2
85.1
86.0
88.2
C 2 H 6 Selectivity %
7.8
6.2
5.4
3.8
CH4 Selectivity %
8.0
8.7
8.6
8.0
Example 2
In example 2 the conversion of acetylene in a wash coated metallic reactor provided with a catalyst at a flow rate of 120 cm 3 /min at different temperatures is shown; feed composition: 10% C 2 H 2 +60% H 2 +30% CH 4 .
TABLE 2
Temperature, ° C.
130
188
200
Time, day
1
2
3
C2H2 conversion, % mole
100
95.2
96.3
C2H4 concentration in outlet gas, % mole
9.1
9.5
9.4
C2H4 selectivity, % mole
84.6
90.0
91.5
C2H6 selectivity, % mole
4.8
4.5
3.1
CH4 selectivity, % mole
10.6
5.5
5.4
Example 3
In example 3 the effect of the flow rate and temperature to acetylene conversion in a quartz reactor provided with a fixed bed catalyst is shown. Feed composition: 10% C 2 H 2 +60% H 2 +30% C 4 , reaction time: 40 hours.
TABLE 3
Temperature, ° C.
160
200
Flow rate, cc/min
60
120
C2H2 conversion, %
87.0
90.2
C2H4 concentration, %
8.7
9.0
C2H4 selectivity, % mole
86.0
85.2
C2H6 selectivity, %
2.7
3.6
CH4 selectivity, %
11.3
11.2
Example 4
In example 4 the results of acetylene conversion in a quartz reactor provided with a fixed bed catalyst at 230° C. are given; flow rate: 120 cm 3 /min; feed composition: 10% C 2 H 2 +60% H 2 +30% CH 4 ; reaction time: 60 hours.
TABLE 4
C2H2 conversion, % mole
96.0
C2H4 concentration in the outlet gas, %
9.1
C2H4 selectivity, % mole
86.0
C2H6 selectivity, % mole
10.2
CH4 selectivity, % mole
3.9
Comparative Example 5
In comparative example 5 the conversion of acetylene in the presence of a fixed bed of 2% Pd/H 3 PO 4 +HZSM-5 catalyst at different temperatures is given: catalyst: 0.4 mg.
TABLE 5
Temperature ° C.
300
350
400
500
Feed total flow rate, cc/mm
10
10
10
3
C 2 H 2 conversion, %
27.4
47.3
57.1
45
C 2 H 4 selectivity, % mole
2.2
5.2
5.5
5.3
Example 6
In example 6 the results of acetylene conversion in a quartz reactor provided with a fixed bed catalyst at 60° C. are given; flow rate: 500 cm 3 /min; catalyst: 0.02 g; feed composition: 10% C 2 H 2 +60% H 2 +30% CH 4 ; reaction time: 60 hours.
TABLE 6
C2H2 conversion, % mole
90.0
C2H4 concentration in the outlet gas, %
8.7
C2H4 selectivity, % mole
89.2
C2H6 selectivity, % mole
4.2
CH4 selectivity, % mole
6.6
Example 7
In example 7 the results of acetylene conversion in a metallic reactor provided with the fixed bed catalyst (Pd-containing catalyst modified with Ag) at 199° C. are given; flow rate: 200 cm 3 /min; feed composition: 9% C 2 H 2 +61% H 2 +30% CH 4 ; reaction time: 60 hours.
TABLE 7
C2H2 conversion, % mole
91.5
C2H4 concentration in the outlet gas, %
8.45
C2H4 selectivity, % mole
90.0
C2H6 selectivity, % mole
5.8
CH4 selectivity, % mole
4.2
Example 8
In example 8, the results of acetylene conversion in a fixed bed reactor are given, filled with glass cylinders, (3 mm ID, 6 mm length), coated with catalyst material and reduced with hydrogen at 380° C. Flow rate 100 cm 3 /min; feed composition: 11.9% C 2 H 2 +64.9% H 2 +23.2% N 2 .
TABLE 8
C2H2 conversion, % mole
97.7
C2H4 concentration in the outlet gas, %
11.06
C2H4 selectivity, % mole
82.6
C2H6 selectivity, % mole
1.7
CH4 + heavy hydroc. selectivity, % mole
15.7
C2H4 yield, % mole
80.7
Example 9
0.12 g metal gauze with more than 65 mesh was used as a support and impregnated with TiO 2 with 30% relative to the weight of qauze. After drying the obtained material, it was impregnated with Pd(NO 3 ) 2 , dried and reduced with hydrogen for one hour at 400° C., whereupon the hydrogenation reaction was started. Flow rate of the mixture is 400 cm 3 /min; gas composition: 20.26% C 2 H 2 , 20.27% N 2 , 59% H 2 .
TABLE 9
C2H2 conversion, % mole
100
C2H4 concentration in outlet gas, %
19.57
C2H4 selectivity, % mole
86.5
C2H6 selectivity, % mole
6.5
CH4 + heavy hydrocarbon selectivity, % mole
7
According to the present invention, the method may be carried out in the presence of a supported catalyst prepared by coating any shape of quartz or ceramic particles, glass cylinders or metal gauze materials with the supported catalyst.
Example 10
Example 10 demonstrates the performance of a reactor coated with TiO 2 +Pd+Ag; Ag/Pd=2, 138 cm 3 /min in the presence of water; gas flow rate 40 cm 3 /min; temperature 269° C.; water amount 0.04 ml/min or 120 cm 3 /min at reaction conditions; gas composition: 12.5% C 2 H 2 +27.5% N 2 +60% H 2 .
TABLE 10
C2H2 conversion, % mole
99
C2H4 concentration in outlet gas, %
12
C2H4 selectivity, % mole
87.8
C2H6 selectivity, % mole
1.5
CH4 + heavy hydrocarbon selectivity, % mole
11.7
As can be seen from the above examples, the conversion of acetylene in the inventive method is stable after 140 hours, and the catalyst in the inventive method is much more stable in comparison to methods of the prior art, where acetylene conversion and ethylene selectivity decreases from the beginning of the reaction.
In case of high acetylene concentrations, the catalyst is stable for 14 days without formation of any coke fragments and activity decrease. In any case of catalyst deactivation during long time screening activity can be restored by treatment consequently with air and hydrogen. During treatment of the catalysts with air there was not observed formation of any amount of carbon monoxide or carbon dioxide.
The features disclosed in the foregoing description or in the claims may, both separately and in any combination thereof, be material for realizing the invention in diverse forms thereof.
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The present invention relates to a method for selective hydrogenation of acetylene to ethylene, comprising the steps of: i) introducing a feed comprising acetylene and hydrogen into a reactor containing a supported catalyst, wherein the reactor is a fixed bed reactor containing the supported catalyst additionally diluted with a solid diluent, or the reactor being a wash coated reactor wherein the supported catalyst is coated on reactor walls; and ii) hydrogenating of acetylene to ethylene in the presence of the supported catalyst.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national stage application of International Application Serial No. PCT/NL2013/050268 filed Apr. 12, 2013, which claims priority to Netherlands Application No. 2008639 filed on Apr. 13, 2012, the contents of each application are hereby incorporated by reference.
BACKGROUND
The present invention relates to a system, a device, and vehicle for recording panoramic images.
A panoramic image is an image with an elongated field of view (FOV). Normally, an optical camera records an image with a limited field of view as defined by the photosensitive component and lens system of the camera. In order to obtain a image of a wider format, one has to use different additional lenses, such as a fisheye lens, or one has to combine multiple images to provide the impression of one large image. The latter process requires stitching of the images. Normally, the multiple images have a slight overlap in their field of view such that an interpolation process can be used to determine the image properties in the overlapping region.
A drawback of combining multiple images is that it is prone to parallax errors. These errors originate from the fact that the multiple images are not recorded from the same position. A solution to this problem is to use rotatable cameras which are mounted on a stand. By making sure that the entrance pupil of the camera remains substantially at the same position, albeit rotated, one can reduce parallax errors to an acceptable degree.
Using a single camera to record a plurality of images that are later combined into a single panoramic image limits the applicability of the technique to the recording of static environments only. Moreover, such technique is not suitable for recording movies as this would require the camera to rotate at impractical speeds. Moreover, such system is not suitable for applications in which the camera itself is moving. Examples of such applications are the recording of panoramic images for navigational systems or derivatives thereof such as Google Street View.
A solution to this problem has been disclosed in U.S. 2002/0089765 A1. The system described therein uses a reflective pyramid in which the reflective sidewalls are under a 45° angle with respect to the base of the pyramid. Cameras are positioned relative to each of the sidewalls such that each camera appears to record an image from a virtual reference point inside the pyramid. In other words, the images recorded by these cameras are identical to the images that would have been recorded by a virtual optical camera positioned at the reference point. Here, reference point corresponds to the position of the entrance pupil of the virtual camera. Using a pyramid with four sidewalls therefore results in four images from four different orientations which can later on be combined into one panoramic image. Moreover, the images making up the larger panoramic image, the so called partial images, appear to have been recorded at substantially the same position of the entrance pupil, thereby reducing or eliminating parallax errors.
A recent trend or desire is to obtain panoramic images with very high resolution, for instance for making detailed measurements in those images. Furthermore, to be able to derive useful information from these images, they need to be metrically correct. These desires can only be partially met by the abovementioned system. Given an optical camera with a predefined resolution one can increase the resolution of the panoramic image by increasing the number of cameras used. This allows a camera to use its full resolution for a relatively small field of view.
A solution to this problem is presented in EP 0 982 946 A1. This system resembles that of U.S. 2002/0089765 A1 with the exception that it describes how different pyramids may be stacked in the vertical direction.
A drawback of the abovementioned system is that it is difficult to stitch the various partial images that are capture by the cameras. To ensure proper stitching, an overlapping region in adjacent partial images is preferred. By using cameras with overlapping FOVs, as disclosed in EP 0 982 946 A1, such overlap can be realized. Unfortunately, the regions of overlap correspond to physical boundaries of the system, such as edges of mirrors or lenses. These boundaries introduce unwanted deformations in the partial images, thereby deteriorating the stitching process.
SUMMARY
It is therefore an object of the present invention to provide a solution to the abovementioned problem such that high resolution parallax error free panoramic images can be recorded.
According to a first aspect of the invention, this object is at least partially achieved with a system for recording panoramic images as defined in claim 1 .
The system of the present invention comprises a device for recording panoramic images, wherein the panoramic images are formed using a plurality of partial images. The device comprises a frame and a plurality of optical pairs, each optical pair comprising a light directing element and an optical camera having an entrance pupil. The light directing element of each optical pair is arranged at a point on a respective parabola, perpendicular to a tangent thereof. The respective parabola has an axis of symmetry and a focus point. The axis of symmetry runs through the vertex and focus point of the parabola.
The light directing element and optical camera of each optical pair are connected to the housing in such a manner that the optical camera records an image obtained via the light directing element as if it were positioned with its entrance pupil at the respective focus point. Hence, each optical pair is assigned a respective focus point and the optical camera appears to have its entrance pupil positioned at the respective focus point.
Each optical pair defines a field of view (FOV) representing a segment of an environment of the device from which light can be captured via directing thereof by the light directing element onto an entrance pupil of the respective optical camera.
The respective focus points of the plurality of optical pairs substantially overlap each other. This allows a parallax error free or error reduced panoramic image. The wording substantially is used here because for some embodiments a slight offset between focus points is desired as will be described later.
The axes of symmetry of the respective parabolas of at least two optical pairs of the plurality of optical pairs are substantially parallel. FOVs defined by these at least two optical pairs are adjacent in a direction parallel to the substantially parallel axes of symmetry.
For instance, if the axes of symmetry extend along a vertical direction, the FOVs defined by the at least two optical pairs are arranged one above the other. The FOVs defined by the at least two optical pairs can be arranged in a stacked manner in the direction parallel to the substantially parallel axes of symmetry.
Alternatively or additionally, the FOVs defined by the at least two optical pairs can overlap in the direction parallel to the substantially parallel axes of symmetry for forming an overlapping region in the form of a ribbon that extends in a circumferential direction with respect to the substantially parallel axes of symmetry. The ribbon generally has a curved shape but is not restricted thereto. The ribbon facilitates the stitching process as will be elucidated later on.
The positioning of the light directing elements is determined by the mathematical concept of a parabola. Because the relevant optical camera is positioned such that it appears to be recording images at the corresponding focus point, its position is also determined by the parabola, albeit indirectly. The respective focus points of optical pairs corresponding to adjacent FOVs are preferably slightly offset relative to each other for allowing a slight overlap between the adjacent FOVs to improve stitching of the plurality of partial images into the panoramic image. The skilled person is aware of various techniques with which the information from overlapping FOVs can be used to obtain a reduced or error free transition between the partial images. This technique is particularly useful for reducing artifacts caused by the mechanical construction of the device. For instance, some parts of the frame may block incident light. Mostly, these elements cause disturbances near the edges of the FOV. Similarly, imperfections in the light direction elements, for instance at the edges thereof, may be a further cause for artifacts.
The parabola has the attracting feature that light incident parallel to the axis of symmetry are directed towards the focus point of the parabola. Consequently, the optical axis of every camera for which the corresponding light directing element is placed on the same parabola is parallel to the axis of symmetry. This allows for a very compact configuration as most cameras are elongated along their optical axes. Aligning these axes allows the cameras to be placed in close proximity to each other.
The system according to the invention further comprises a controller to individually and independently trigger each optical camera to record a partial image. A motion calculator is employed to calculate a distance travelled by the system in a movement direction. A processing unit to calculate a timing difference between optical cameras based on the relative offset of their focus points in the direction of movement.
The controller is arranged to trigger the optical cameras using the calculated timing difference in a manner such that the optical cameras record partial images as if their entrance pupils were at substantially the same position in the direction of movement at the time of recording the partial image. For instance, if two optical cameras are used of which, in a direction of movement, the corresponding focus points are separated by a distance D, the triggering of the camera in the rear will trail the triggering of the camera in the front by D/v seconds, wherein v represents the velocity of the system. This ensures that the camera in the rear records an image at the same position with reference to the environment as the camera in front.
The present invention provides an improved stitching process whereby the deteriorating effects of physical boundaries in the optical system are alleviated by a combination of an intentional shift of the focus points of the cameras from their ideal position and a suitable triggering to compensate for the parallax errors introduced by the intentional shift.
At least the device for recording panoramic images may be mounted on a moveable vehicle, wherein the respective focus points of the plurality of optical pairs are positioned along a substantially straight line that corresponds to a default direction of movement of said moveable vehicle. In this manner, parallax errors can be removed substantially entirely. Other components of the system for recording panoramic images may also be mounted on the vehicle. Alternatively, parts of the system are mounted on the vehicle while other parts are not. Wireless technology may be used for communication between the different parts of the system. In a preferred embodiment, the system is entirely mounted on the vehicle.
If the device is moving along the straight line and the individual cameras are properly triggered, it can be achieved that at the time of recording an image, the virtual entrance pupils of the respective cameras, i.e. the respective focus points, are at the same position.
It is also advantageous if the optical axes of the optical cameras of said at least two optical pairs are substantially parallel. Preferably, the parabolas of the at least two optical pairs are substantially overlapping.
Herein, the wording substantially is used to indicate that small deviations with respect to the ideal mathematical shape of a parabola are not excluded from the scope of the present invention. For instance, the skilled person will appreciate that by not placing the light directing element exactly at a point on the parabola, the optical axis of the optical camera will not be exactly parallel to the axis of symmetry. Moreover, for some applications, small deviations will be acceptable or desirable.
The axes of symmetry of the respective parabolas are preferably substantially parallel to a common axis of symmetry. It is further advantageous if the curvature of the parabolas is substantially equal whereby the plurality of respective parabolas substantially defines a paraboloid.
It is further advantageous if the device has a conical or pyramid shape and/or is elongated in the direction of the common axis of symmetry. In addition, in some embodiments it is possible to divide the plurality of optical pairs into at least two groups, wherein each group is arranged for recording a circumferential ribbon of adjacent partial images around a longitudinal axis of the conical or pyramid shape, or the common axis of symmetry, albeit at a different longitudinal position.
The skilled person will understand that, given the fact that a slight offset must exist for the focus points to improve the stitching process, the combination of parabolas will not amount to a perfect mathematical ideal paraboloid.
In addition, it is advantageous if the light direction elements of each optical pair in the same group have substantially the same longitudinal position and if the optical cameras of each optical pair in the same group have substantially the same longitudinal position.
The previous embodiments, in which a light directing element was used in combination with an optical camera, can be combined with an optical camera arranged substantially at one of the focus points. Preferably, this optical camera has an optical axis substantially parallel to one of the axis of symmetry of a previously mentioned parabola. When this camera is combined with the configuration of the groups of cameras, a device is obtained with which a semi-sphere or similar shape around the device can be captured at high resolution.
For each optical pair the distance between the respective focus point and the corresponding point on the parabola is preferably equal to the distance between the corresponding point and the entrance pupil of the respective optical camera. This ensures that the optical camera operates as a virtual camera with its entrance pupil at the respective focus point. Here, the optical axis of the virtual camera crosses the corresponding point on the parabola.
The light direction element could for instance be an optical reflective element, such as a mirror, or a combination of mirrors. In a further embodiment, each of a plurality of the optical pairs comprise a mirror that is part of an integrally formed curved mirror. Hence, instead of a plurality of discrete mirrors, a single integrally formed mirror can be used. Such mirror would reduce the artifacts normally attributed with the edges of the mirrors. When different groups of optical pairs are used, it is advantageous if the mirrors of each group are part of a respective integrally formed curved mirror.
Instead of or in addition to the reflective element, the light direction element could be a refractive element, such as a prism or a ray bender.
The skilled person is aware of various technologies in which to implement the various components of the present invention. Here, the wording optical camera is used to indicate any element, device or system that is capable of recording an optical image by using a light sensitive component such as a charge coupled device (CCD) or light sensitive film.
Due to the compact nature of the device according to the present invention, it becomes feasible to realize at least one of the light direction elements and/or optical cameras in Micro Electro Mechanical Systems (MEMS) technology.
According to second and third aspect, the present invention also provides a moveable vehicle and a device for recording panoramic images as defined in claims 17 and 18 , respectively. In a preferred embodiment, the moveable vehicle is a motorized vehicle, such as a car.
DESCRIPTION OF THE DRAWINGS
Next, the invention will be described in more detail using the appended figures, in which:
FIG. 1 illustrates an embodiment of a device for recording panoramic images according to the present invention;
FIG. 2 depicts a schematic side view of the embodiment in FIG. 1 ;
FIGS. 3A-3E explain the arrangement of the optical mirrors and cameras of the embodiment in FIG. 1 ;
FIGS. 4A-4C present a three-dimensional representation of the segments covered by the optical cameras described in conjunction with FIGS. 3A-3E ;
FIGS. 5A-5B illustrate the principle of overlapping field of views to facilitate the stitching process; and
FIG. 6 illustrates a further example of overlapping field of views to facilitate the stitching process.
DETAILED DESCRIPTION
FIG. 1 illustrates an embodiment of a device for recording panoramic images according to the present invention. This embodiment comprises 2 groups of optical pairs. The first group comprises six optical cameras 1 and six associated optical mirrors 1 ′. Similarly, the second group comprises six optical cameras 2 and six associated optical mirrors 2 ′. In FIG. 1 , a separate optical camera 6 is arranged in between optical mirrors 1 ′.
The field of view (FOV) indicates a segment of an environment of the device from which light can be captured via directing thereof by the optical mirrors 1 ′, 2 ′ onto an entrance pupil of the optical cameras 1 , 2 . For instance, segments 3 and 4 represent the FOV corresponding to one of the optical cameras of the first and second group, respectively. Segment 5 corresponds to the optical camera that is arranged within optical mirrors 1 ′. Light incident on this camera is not reflected by an optical mirror.
It is clear from FIG. 1 that each optical camera 1 , 2 captures only a relatively small segment of the environment of the device. Hence, such segment is photographed using a relatively high resolution. This allows a high resolution panoramic image to be obtained.
FIG. 2 depicts a schematic side view of the embodiment in FIG. 1 . Here, only a single optical camera 1 , 2 per group is illustrated. Moreover, mirrors 1 ′, 2 ′ are indicated by a straight line. The dotted lines indicate a two-dimensional representation of the FOV that corresponds to each optical camera 1 , 2 , and 6 .
In FIG. 2 , a parabola P is illustrated according to which optical mirrors 1 ′, 2 ′ are placed. Moreover, a single optical camera 6 , corresponding to segment 5 , is placed with its entrance pupil at the focus point of parabola P.
Next, the arrangement of optical cameras 1 , 2 and optical mirrors 1 ′, 2 ′ is explained using FIGS. 3A-3E . Here, FIGS. 4A-4C present a three-dimensional representation of the segments covered by the optical cameras described in conjunction with FIGS. 3A-3E .
Firstly, FIG. 3A shows that single optical camera 6 is arranged with its entrance pupil at focus point 7 of parabola P. Also illustrated in FIG. 3A is axis of symmetry I for parabola P, which coincides with the optical axis of optical camera 6 .
FIG. 3B shows the orientation of a virtual camera 8 , having its entrance pupil at focus point 7 , which would allow segment 3 to be captured. Here, point 10 illustrates where optical axis 9 intersects parabola P.
FIG. 3C illustrates optical camera 1 which is arranged such that the distance between the entrance pupil of optical camera 1 and point 10 equals the distance between point 10 and focus point 7 . The orientation of optical mirror 1 ′ is such that segment 3 is covered. Moreover, actual optical camera 1 and virtual camera 8 are each other mirror images with respect to optical mirror 1 ′. Consequently, the light captured by optical camera 1 equals that which would have been captured by virtual camera 8 . Moreover, the apparent position of the entrance pupil of optical camera 1 is focus point 7 . Hence, images taken by optical cameras 1 and 6 appear to have been taken from the same point, i.e. focus point 7 . At this point, it should be noted that in this explanation, the offset between the various focus points is not included. This will be elucidated with reference to FIGS. 5A and 5B .
FIG. 3D illustrates a virtual optical camera 11 that is positioned to cover segment 4 . Optical axis 12 of camera 11 intersects parabola P at point 13 . FIG. 3E shows the arrangement of actual optical camera 2 and optical mirror 2 ′. Again the distance between the entrance pupil of optical camera 2 and point 13 equals that of the distance between point 13 and focus point 7 . The orientation of optical mirror 2 ′ is such that segment 4 is covered. Optical camera 2 and virtual optical camera 11 are each other mirror images with respect to optical mirror 2 ′.
Optical cameras 1 , 2 both have their optical axis parallel to axis of symmetry I depicted in FIG. 3A . Also, referring back to FIG. 1 , it is apparent that every optical camera has its optical axis parallel to axis of symmetry. This also allows a close stacking of optical cameras. Furthermore, the focus points corresponding to the various parabolas used for arranging the optical cameras and optical mirrors in correspondence with the method disclosed in FIGS. 3A-3E are substantially overlapping. In reality a small offset must be employed to improve the stitching process as will be described later on.
The respective parabolas corresponding to the optical pairs in FIG. 1 define a paraboloid having a single focus point that corresponds substantially to the focus points of the individual parabolas. Although preferred, the present invention does not exclude the possibility that different parabolas are used for different optical pairs. For instance, one optical pair could be placed in accordance with a parabola having a larger curvature than other optical pairs, albeit having substantially the same focus point.
FIGS. 5A-5B illustrate the principle of overlapping field of views to facilitate the stitching process.
When stitching the partial images that are recorded by the optical cameras, distortion may occur near the edges of the light direction elements and/or parts of the frame may block incident light in particular near the region of overlap. To prevent these deteriorating effects or to reduce their effect in the final panoramic image, it is advantageous to ensure a certain overlap between neighboring FOVs. The information contained in the overlap can be used to at least reduce the impact of the distortions.
FIG. 5A illustrates, in a top view, how the overlap can be achieved. By introducing an offset between the focus points 20 , 21 corresponding to neighboring FOVs, an overlap 14 occurs near the edges of the segment. Here, point 20 represents the overlapping focus points corresponding to the optical pairs with respect to the remaining three segments. This is illustrated in more detail in FIG. 5B . Here, dots 16 , 15 illustrate the actual position of optical camera 17 and the corresponding virtual camera 18 , respectively, with respect to the positions based on overlapping focus points coinciding with focus point 7 . In this example, the position of optical mirror 19 has not changed compared to the position corresponding to overlapping focus points.
In FIG. 5B , dot 15 represents the position of the entrance pupil of virtual camera 18 which would result in the desired overlap. If required, optical camera 17 can be chosen such that it has a larger angle of view. Dot 16 corresponds to the position of the actual optical camera 17 . At this position, the light that would be captured by virtual camera 18 at the position indicated by dot 15 , corresponds to that captured by optical camera 17 .
Although this positioning produces the desired overlap it introduces parallax errors because the partial images are not taken from the same position. To solve this problem in the specific case where the device is moving in a direction indicated by arrow A, optical camera 17 is triggered to record an image when the position of its apparent entrance pupil 15 , or at least a component thereof in the direction of movement, is the same as that of the other cameras at the time of recording the image. In a system comprising a plurality of cameras, this would involve the individual triggering of each camera such that the position of the entrance pupil of the virtual camera, or at least a component thereof in the direction of movement, would be the same for each camera at the time of recording an image by that camera.
FIG. 6 presents a different arrangement of focus points corresponding to the respective optical pairs. Compared to FIG. 5A , it is apparent that these focus points all lie on a straight line that corresponds with a direction of movement indicated by arrow A. Here, focus points ( 36 , 37 , 38 , 39 ) correspond respectively to field of views ( 30 , 31 + 35 , 32 + 34 , 33 ), where “+” indicates that these field of views correspond to an identical focus point. By individually triggering the various optical cameras, such that at the time of recording an image the virtual entrance pupil of each optical camera (i.e. the corresponding focus point) is at the same position, parallax errors can be completely eliminated. This is contrary to FIG. 5B , where a small shift perpendicular to the direction of movement remains.
It should be apparent to the skilled person in the art, that various other types of offset are possible to generate the desired overlap.
The present invention is particularly well suited for applications in which the panoramic images should be metrically correct. In such systems it is important to detect deformations of the optical system such that these deformations can be corrected or accounted for. Such detecting of deformations can be made part of a calibration of the system.
Several options may be used by which the system can be calibrated. As a first option, fiducials may be placed on reflective components, such that they appear in parts of the partial image that are not used in the final panoramic image. For instance, fiducials may appear in the overlapping regions.
As a second option, fiducials may be placed on reflective components, such that they appear in parts of the partial image that are used in the final panoramic image. In this case, the fiducials could be realized with special paint that is only visible when applying special light, such as infrared light. An infrared light source, such as a light emitting diode, can be part of the system for illuminating the fiducials during calibration.
As a third option, auxiliary light sources can be placed on known positions with respect to the reflective components. By capturing the light from these auxiliary light sources using the cameras, information can be obtained about the reflective components.
It should further be apparent to the skilled person that the present invention is not limited to recording still images only. The recording of moving images, for the construction of a high-resolution panoramic movie, also falls within the scope of the invention.
Although the present invention has been described using embodiments thereof, it is not limited thereto. Various modifications to these embodiments are possible without departing from the scope of protection that is defined by the appended claims.
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The present invention relates to a system, a device, and vehicle for recording panoramic images. According to the present invention, panoramic images can be obtained using a plurality of optical cameras and light directing elements which are arranged based on a parabola. This allows a compact device to be obtained while ensuring that each camera records a partial image as if it were at substantially the same focus point as the other cameras. By arranging the plurality of cameras and light directing elements such that the respective focus points are slightly offset relative to each other, a slight overlap between adjacent field of views can be obtained to improve stitching of the partial images to from the panoramic image.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to belts for use on conveyors, treadmills, and the like, and more particularly to an interwoven belt fabric for use in such belts.
[0003] 2. Background Art
[0004] Endless belts are typically formed by joining opposite ends of a section of belt material and used in a number of different applications. One commonly known application for such endless belts is in physical exercise equipment such as treadmills, as well as in various material handling applications such as check-out counters in stores, and the like.
[0005] In a treadmill used for physical exercise, a motor driven belt extends over a flat running deck. The typical treadmill belt consists of woven material provided with a top layer of polyvinyl chloride or the like. Since the woven belt material forming the bottom surface of the woven belt is forced into contact with the top surface of the running deck by the weight of the person using the exercise equipment, the belt preferably has specific characteristics such that the belt has a low coefficient of friction with the deck, has a consistent stability when under load, produces a minimum noise and provides enhanced performance with the addition of lubricants between the surface of the deck and the belt.
[0006] The type of fabric used, to a very large extent, determines certain characteristics of the belt, such as the coefficient of friction, ability to dissipate heat, ability to absorb lubricants, stability, and noise generation. Typically, in prior art belts, the quieter belts have a higher coefficient of friction and belts made with a multi-filament warp yarns (i.e., yarns with long staple lengths) tend to have a lower coefficient of friction than spun warp yarns (i.e., yarns with short staple lengths). Furthermore, treadmill belts made with a typical plain weave fabric using multi-filament warp yarns and monofilament fibers in the weft generally have a relatively low coefficient of friction, but generate a relatively high level of noise.
[0007] In a typical prior art plain weave fabric, multi-filament warp yarn is alternately woven over and under a series of adjacently disposed monofilament weft fibers. In one prior art belt fabric, referred to as a one-by-three whisper weave-broken twill fabric, a multi-filament warp extends over one monofilament weft and under three monofilament controller is manually operable from a location remote from the latches such that the latches are manually and remotely controlled
[0008] In another embodiment, the present invention is a fingerboard having at least one fingerboard row for storing a plurality of threaded tubulars. A plurality of latches are connected to the at least one fingerboard row, wherein each of the plurality of latches is biased into a locked position and movable between the locked position and an unlocked position. A piston having an elongated rod is slidingly engaged with a casing, wherein the casing has a plurality of exhaust ports in fluid connection therewith, and wherein each of the plurality of exhaust ports is connected to a corresponding one of the plurality of latches. An air source is in fluid connection with the casing, wherein the elongated rod is movable between a fully retracted position and a plurality of extended positions corresponding to each of the plurality of exhaust ports, wherein in the fully retracted position each of the exhaust ports are covered by the elongated rod, such that air from the air source cannot flow therethrough allowing each of the corresponding latches to be biased in the locked position, and wherein in each successive one of the plurality of extended positions a successive one of the plurality of exhaust ports is uncovered such that air flows therethrough to force a successive one of the corresponding latches to move from the locked position to the unlocked position.
[0009] In yet another embodiment, the present invention is a fingerboard having at least one fingerboard row for storing a plurality of threaded tubulars. A plurality of latches are connected to the at least one fingerboard row, wherein each of the plurality of latches is biased into a locked position and movable between the locked position and an unlocked position. A piston having an elongated rod is slidingly engaged with a casing, wherein the casing has a plurality of exhaust ports in fluid connection therewith. Each of a plurality of conduits fluidly connects one of the plurality of exhaust ports to a corresponding one of the plurality of latches. An air source is in fluid connection with the casing, wherein the elongated rod is movable between a fully retracted position and a plurality of extended positions corresponding to each of the plurality of exhaust ports, wherein in the fully retracted position each of the exhaust ports are covered by the elongated rod, such that air from the air source cannot flow therethrough allowing each of the corresponding latches to be biased in the locked position, and wherein in each successive one of the plurality of extended positions a successive one of the plurality of exhaust ports is uncovered such that air flows therethrough to force a successive one of the corresponding latches to move from the locked position to the unlocked position. A piston guide is connected to the piston and has a plurality of stop positions, wherein each of the plurality of stop positions corresponds to one of the plurality of extended positions of the elongated rod.
[0010] In still yet another embodiment, the present invention is a method of storing a plurality of threaded tubulars in a fingerboard including providing a fingerboard row for storing the plurality of threaded tubulars; providing a casing having a plurality of exhaust wefts. Another prior art belt fabric, referred to as an interwoven fabric, has a layer of upper monofilament weft yarns and a layer of lower monofilament weft yarns. The two layers are separated by a light denier yarn and each of a plurality of multi-filament warp binder yarns extend under one of the lower monofilament weft yarns and over an adjacent upper monofilament weft yarn.
[0011] A problem with the prior art one-ply plain weave and whisper weave belts, when used in a treadmill belt or the like, is that they lack the desired stiffness required under various loads and at various speeds. When such materials are used, a two ply belt is typically required to obtain the desired stiffness. However, two ply belts are considerably more expensive to produce than single ply belts. For example, the manufacture of a two-layer belt may require as many as five passes through a belt making machine, one for the inner layer, one for the cover and three for the glue layers.
[0012] Prior art interwoven fabrics are generally considered to be undesirable for use in belts, because belts made of such fabrics are relatively noisy and the fabric typically has to be saturated with a plastic material to prevent the weft yarns from migrating out of the side of the belt.
[0013] Treadmill belts typically are operated at a higher speed than standard conveyer belts used for material handling and are typically subjected to greater concentrated loads as a result of the running action of a person on the belt. Hence, treadmill belts must be relatively stiff, particularly in the lateral direction. Such stiffness is generally obtained in prior art belts by making a thicker one-ply belt or by using two-ply belts.
[0014] Prior art one-ply and two-ply belts are comprised of a single layer of fabric or a double layer of a fabric, respectively, and a top cover layer of rubber or vinyl, or the like. The majority of such belts use monofilament yarns in their weft since material of that construction typically provides a relatively stable belt that lays flat, does not bunch up, and tracks straight. Generally, thicker belts are more stable than thinner belts and two-ply belts are more stable than one-ply belts.
[0015] However, thicker belts are typically relatively heavy and stiff in the longitudinal direction, thereby presenting a relatively higher load to the electric motor used to drive the belt. The higher load to the motor requires that a larger, more expensive motor be used which typically draws more current, all of which adds to the cost of the equipment and its operation. Therefore, a light weight, highly flexible, low friction belt is clearly desirable for applications such as treadmills. Furthermore, treadmill belts are subjected to much greater speed variations than standard conveyer belts. Hence, a belt for use in a treadmill application must be stable at high speeds as well as at low speeds.
[0016] To reduce power consumption and the generation of heat, it is desirable to reduce friction between the belt and the running deck. Hence, belts with a low coefficient of friction are preferred. Additionally, lubricants are often applied between the belt and the running deck to further reduce friction. A lubricant such as paraffin wax, Teflon®, or solventless silicone is commonly used to reduce friction between the belt and the deck. In order for a lubricant to be used effectively, however, the belt must be able to absorb a certain amount of the lubricant. Certain prior art plain weave and interwoven belts having monofilament yarns in their weft, have the desirable properties that they tend to lay flat, do not bunch up, and track straight. However, such belts do not absorb or hold lubricants well.
[0017] An interwoven fabric disclosed in U.S. Pat. No. 6,328,077 is two-ply fabric made of two layers of weft yarns in couplets, with warp yarns extending over and under adjacent couplets in a pattern where warp yarns extend under more couplets in the lower layer than extend over couplets in the upper layer. A central warp yarn of standard light denier extends between the upper and lower layers. This fabric works well as a solution to the aforementioned problems, but an improvement has been discovered that more effectively performs.
SUMMARY OF THE INVENTION
[0018] According to the invention, a belting fabric comprises a plurality of adjacently disposed couplets of weft yarns, a plurality of binder warp yarns, and a plurality of middle warp yarns. The couplets form an upper layer of weft yarns and a lower layer of weft yarns. The binder warp yarns each extend over at least one of the couplets of weft yarns in the upper layer and under at least two of said adjacently disposed couplets of weft yarns in the lower layer. The middle warp yarns extend between the upper layer and the lower layers and are sufficiently straight and inelastic to bear loads under tension without twisting or stretching.
[0019] Preferably, the middle warp yarns are formed of PET and have a denier of at least 550. Also, preferably, the middle warp yarns are heat set under tension.
[0020] In another aspect of the invention a method of making a belting fabric includes the steps of arranging a plurality of couplets of weft yarns adjacent one another into an upper layer of weft yarns and a lower layer of weft yarns and weaving a plurality of middle warp yarns between the upper and lower layers. Also, a first warp yarn is woven over a first of said couplets of weft yarns and under a second and a third of the couplets of weft yarns, disposed adjacent the first of the couplets, a second warp yarn over a second of the couplets of weft yarns and under a third and fourth of the couplets of weft yarns, disposed adjacent the second of the couplets; and a third warp yarn over a third of the couplets of weft yarns and under fourth and fifth of the couplets of weft yarns, disposed adjacent the third of the couplets. Finally, the middle warp yarns are heat set.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is side elevational view of a section of conveyer belting material incorporating the principles of the invention;
[0022] FIG. 2 is an enlarged side elevational view of the belting fabric of FIG. 1 , having a weave pattern in accordance with principles of the invention;
[0023] FIG. 3 illustrates the pattern of a single warp binder yarn in the weave pattern of FIG. 2 ;
[0024] FIG. 4 is an enlarged side elevational view of a section of conveyer belting fabric of FIG. 1 having an alternate weave pattern in accordance with principles of the invention; and
[0025] FIG. 5 illustrates the pattern of a single warp binder yarn in the weave pattern of FIG. 4 .
DETAILED DESCRIPTION
[0026] Shown in FIG. 1 is a section of conveyor belting material 100 comprising a fabric layer 101 and a cover layer 102 . The cover layer 102 may be a standard rubber or plasticized polyvinyl material or the like. One embodiment of a belting fabric 100 in accordance with the invention is illustrated in FIG. 2 in an enlarged side elevational view of a portion of the belt 100 . The belting fabric of FIG. 2 includes an upper layer of monofilament weft yarns 105 and a lower layer of monofilament weft yarns 106 . The individual weft yarns of layer 105 are disposed in substantial alignment with individual weft yarns of layer 106 , forming a plurality of couplets, 110 through 119 . The monofilament weft yarns preferably have a diameter of approximately 0.3 mm.
[0027] The two layers of weft yarns 105 , 106 are separated by inelastic middle warp yarns 107 in accordance with the invention. The middle warp yarns are sufficiently straight and inelastic to bear loads under tension without twisting or stretching. Each middle warp yarn 107 is preferably formed of PET having a denier of 550, although any polymer, rendered effectively inelastic, will suffice. The middle warp yarns 107 are heat set under tension to make them straight and inelastic.
[0028] A plurality of binder warp yarns 120 , 121 , 122 are woven on the weft yarns to form a belt fabric. The fabric layer 101 is woven in a repeating weaving pattern wherein three binder warp yarns 120 , 121 , and 122 are woven through a plurality of adjacently disposed couplets formed from aligned pairs of weft yarns of layers 105 and 106 , in a specified pattern. In this pattern the first binder warp yarn 120 extends over a first aligned couplet of weft yarns 110 and under second and third couplets 111 , 112 , respectively; the second binder warp yarn 121 extends over the second couplet 111 and under third and fourth couplets 112 , 113 , respectively; and the third binder warp yarn 122 extends over the third couplet 122 and under fourth and fifth couplets 113 , 114 , respectively.
[0029] The specific pattern of the warp yarns shown in FIG. 2 is further illustrated in FIG. 3 in which the pattern of a single binder warp yarn 120 is shown separate from the other binder warp yarns.
[0030] FIG. 4 depicts an alternate embodiment of a belt 200 in accordance with the invention wherein the fabric 201 comprises four binder warp yarns 220 , 221 , 222 , and 223 woven into two layers of weft yarns 206 , 207 . The layers of weft yarns 206 , 207 are separated by inelastic middle warp yarns 208 in accord with the invention. As before, each middle warp yarn 107 is preferably formed of PET having a denier of 550, although any polymer, rendered effectively inelastic, will suffice. The middle warp yarns 107 are heat set under tension to make them straight and inelastic.
[0031] The binder warp yarns 220 , 221 , 222 , 223 are preferably 1,000 denier yarns and the weft yarns 206 , 207 are preferably approximately 0.3 mm monofilament yarns. The fabric 201 is woven in a repeating weaving pattern wherein four binder warp yarns 220 , 221 , 222 and 223 are woven in a specified pattern through a plurality of couplets formed from pairs of aligned weft yarns of layers 206 , 207 . In this pattern the first binder warp yarn 220 extends over a first aligned couplet of weft yarns 210 and under the second, third and fourth couplets 211 , 212 and 213 , respectively; the second warp yarn 221 extends over the second couplet of weft yarns 211 and under the third, fourth and fifth couplets 212 , 213 and 214 , respectively; the third warp yarn 222 extends over the third couplet of weft yarns 212 and under the fourth, fifth and sixth couplets 213 , 214 and 215 , respectively; and the fourth warp yarn 223 extends over the fourth couplet of weft yarns 213 and under the fifth, sixth and seventh couplets 214 , 215 and 216 , respectively.
[0032] The specific pattern of the binder yarns of FIG. 4 is further illustrated in FIG. 5 in which the pattern of a single binder warp yarn, yarn 221 , is shown separate from the other binder warp yarns.
[0033] Belt material in accordance with the present invention is preferably manufactured by feeding the woven belt fabric, e.g., 100 , 200 , from a roll of the fabric into a well-known belt coating apparatus. Such apparatus typically includes a feeding mechanism extending the belt between a roller and a coating knife. Liquid PVC, such as a well-known product referred to in the trade as “Plastisol,” is applied in a standard fashion. The belt material with the newly applied coating is then fed into an oven and heated by infrared lamps or the like to dissolve the applied PVC. After passing through the oven, the belt material with the applied PVC is fed between a roller and a cooling drum while cooling the belt. This causes the PVC to be forced into cavities in the woven material.
[0034] One advantage of the belting fabric is that it has cavities of substantial size that provide for proper adhesion of the PVC layer to the fabric. As a result, glue lining required for belts made of prior art belt fabrics is not required. The application of such a glue lining requires that the belt material be fed through a glue application mechanism, similar to the PVC application mechanism. Accordingly, a belt made in accordance with the present invention is substantially less expensive to manufacture. More importantly, however, the stronger middle warp yarns are believed to be the ones primarily under tension during operation of the belt. Since they are the load-carrying yarns, the upper and lower layers on either side of the middle warp yarns are under no load, an thus do not wear as quickly as belts of the prior art. The result is a more durable belt.
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An interwoven belting fabric for use in conveyors, including treadmills, is constructed of a dual layer of weft yarns comprising adjacent couplets, a plurality of middle warp yarns, and a plurality of binder warp yarns. Each middle warp yarn is heat set under tension so that it is sufficiently straight and inelastic to bear loads under tension without twisting or stretching.
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This application claims benefit of provisional application No. 60,083,671 filed Apr. 30, 1998.
TECHNICAL FIELD OF THE INVENTION
This invention relates to a modular masonry step and deck assembly for entering an elevated entrance to a building, the assembly including a plurality of dry stacked like-shaped risers and a plurality of like-shaped treads that can be assembled into a variety of shapes, sizes and heights to provide a custom fit for a variety of buildings, each tread having one of a few designs on its surface that combine to produce a continuous, integrated design.
BACKGROUND OF THE INVENTION
Foundations and entrances of buildings are typically elevated above ground level. Steps and a deck or stoop are provided to allow a person to walk or climb up to or near the level of the threshold of the door. Each step has a given rise and a given depth to allow the person to safely negotiate the step. A series of steps requires a certain amount of surface area in front of the door. The deck or stoop forms a platform with enough surface area for a person to safely open and enter or exit through the door. The size and shape of the available area for constructing the steps and deck varies due to obstructions, such as the building foundation, adjacent structures, driveways, walkways, trees, bushes and gardens. Other considerations, such as the locations of widows, mail boxes and sitting areas can also affect the location, size and shape of the step and deck construction.
A variety of approaches have been developed for constructing steps and decks leading into building. While some of these approaches provide flexible constructions that are easily adapted to the size and shape of a specific area, they lack durability and maintainability. Other approaches provide constructions that are durable and easy to maintain, but lack the flexibility to adapt to a variety of applications. These constructions can also be difficult to alter or remove. Providing a continuous, integrated design in the surface of conventional step and deck constructions creates further problems for conventional approaches.
Wooden step and deck assemblies are flexible and can be custom fit to the contours of a specific building, mobile home or trailer and its landscaping. A problem with wooden step and deck constructions is that they lack long term durability and require frequent upkeep due to the loosening of nails, screws, bolts or other fixtures, as well as the need for routine applications of weather inhibitors to slow down rotting caused by rain, wind, snow and ice. Additional types treatments are used to reduce the rate of deterioration of the wood resulting from the constant wear and tear of use, salt, gravel, dirt and even snow and ice removal. The smooth and frequently slippery surface of lacquered wood requires the use of anti-skid mats or strips to be applied to the walking surfaces. In addition, wooden step and deck constructions are typically anchored by several posts or supports embedded in the ground. These posts or supports can shift and heave over time, especially in regions subject to frequent freezing and thawing. Digging up and resetting these post or supports can be difficult and labor intensive, particularly in the cramped areas next to the building and its landscaping.
Precast concrete step and deck constructions are typically more durable and require less upkeep than wooden assemblies. However, the large slabs that form the steps and decks are heavy to lift and move, and difficult to align during installation. Motorized construction equipment or special tools are usually required. For cost reasons, manufacturers tend to massproduce a limited selection of precast step and deck slabs, each slab having a specific shape and size. The limited selection is frequently unable to conform to the size and shape of the area allocated for the step and deck construction. While custom precast concrete step and deck slabs are possible, the manufacturing and shipping costs result in significantly greater unit prices. Moving, removing, altering or adding to a large precast step or deck construction can also be labor intensive and expensive.
Poured concrete step and deck constructions conform to the specific building and landscape design. However, these constructions require the time and expense of building forms and the delivery or mixing of the concrete. Special layout, carpentry, and concrete finishing skills are also required. Poured concrete steps and decks are also prone to cracking due to the settling or freezing and thawing of the ground supporting the steps and deck. The removal or replacement of these larger poured concrete slabs can also be prohibitive. Again, large construction equipment can be required. As with precast constructions, removing, altering or adding to the precast construction can be labor intensive and expensive should the owner want to move, expand or add a handicap access ramp to the construction.
While dry stacked constructions have been developed to form retaining walls and building walls, the instability of a multi-column, multi-row, multi-tier dry stacked assembly has inhibited its adoption in step and deck constructions. Even a single column wall system will utilize a mechanism for securing the risers together. For example, many retaining wall systems utilize a projection extending from the lower surface of the block to grip the block beneath it. A variety of hardware fastening systems can also be used to secure the single column of blocks together. Retaining wall constructions typically stagger the blocks laterally from tier to tier to form a running bond construction that increases the strength of the wall. Each tier or course of blocks is also set back from its lower tier so that the wall leans into the hill it is retaining. While a staggered running block construction utilizing a set back is appropriate for a dry stacked retaining wall construction, such attributes render the blocks inappropriate for a step and deck assembly.
Some conventional warehouse wall constructions utilize a column of dry stacked blocks between poured concrete pillars. A fiberglass reinforced plastered sheet is placed on each side of the dry stacked blocks to keep them in place. The expense of forming poured concrete pillars and applying reinforced plaster sheets renders such a construction inappropriate for a step and deck assembly. Pouring concrete down the hollowed out cores of the dry stacked blocks to hold them in place is also known. However, such constructions include the expense of a significant amount of concrete, as well as the mess of mixing and filling the cores of the stacked blocks. Such constructions are also difficult to remove or alter.
Incorporating a continuous, integrated pattern into the walking surface of a masonry step and deck construction further complicates its design. While a precast step and deck slab construction can incorporate a pattern on its surface, these patterns make it even more difficult to integrate two separate slabs. Poured concrete constructions require a skilled mason to form the design into the concrete while it is setting, which further adds to the cost and inconvenience of such constructions. Extending the continuous pattern into the walkway leading to the steps and deck creates further problems. Precast concrete steps and decks are not sized or shaped to create walkways. Poured concrete walkways with hand formed designs add to an already expensive construction technique.
The present invention is intended to solve these and other problems.
BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a modular masonry step and deck assembly consisting of a plurality of like-shaped risers and a plurality of like-shaped treads that enable the assembly to have a variety of shapes, sizes and heights to provide a custom fit to a variety of buildings, mobile homes or trailers. The risers are dry stacked in a multi-tier, multi-column, multi-row arrangement to form a base of the assembly. An inwardly expanding groove is formed in each corner of each riser. When aligned flush with adjacent risers and dry stacked one atop the other in a stacked bond arrangement, the groves form a continuous vertical channel. A semi-flexible locking key is formed inside the channel to secure the risers together, but accommodate movements caused by the freezing and thawing of the ground. Four differently shaped treads are used to form the walking surface of the step and deck assembly. Each tread shape is used to form a specific portion of the walking surface. A plurality of each like-shaped tread is used to form its specific portion of the walking surface to create a continuous lip around the perimeter of the steps and deck. Each of the four like-shaped treads has a specific design on its top surface to form an integral, continuous pattern on the steps and deck. The treads can be used to continue the design into a walkway.
One advantage of the present masonry step and deck assembly is that the modular structure of its components provides the flexibility to produce a customized fit to accommodate the size and shape of the available area for various buildings. The number of tiers, rows and columns of risers forming the base of the assembly can be varied to accommodate the height of the door, the shape of the building foundation, adjacent structures, driveways, walkways, and landscaping, such as trees, bushes and gardens. The step and deck assembly can also be constructed to accommodate the locations of widows, mailboxes and sitting areas. The modular construction also allows the components to be sized so that a homeowner can lift and align them by themselves without the aid of motorized equipment or special tools.
A further advantage of the present masonry step and deck assembly is that the semi-flexible locking keys permit a degree of movement between adjacent risers. This gives the unitary base the ability to absorb movements in the ground caused by freezing and thawing. No mortar is needed which would inhibit the flexibility of the base and crack over time. Instead, the semi-flexible keys continue to hold the risers together to form the unitary base even when the risers are moved out of direct flush contact with their adjacent risers. The flexible keys also allow the risers to move back into direct flush contact when the ground settles back to its unfrozen condition. Instead of using embedded posts, the entire unitary base can be said to float on the ground.
Another advantage to the present masonry step and deck assembly is its durability and relatively maintenance free upkeep. The masonry treads are capable of handling heavy traffic for over relatively long periods of time without showing signs of war and tear, even when subjected to salt, gravel, dirt, and snow and ice removal. No nails, screws or bolts need to be tightened. Weather inhibitors and other protective coatings are not necessary to prevent or reduce the rate of deterioration of the masonry components.
A still further advantage of the present masonry step and deck assembly is that it enables a home owner to easily customize the step and deck assembly to fit their specific home, identify and procure the necessary components, and install the assembly. No, special layout, carpentry, and concrete finishing skills are also required. No forms need to be built, and no concrete needs to be delivered or mixed. The unitary base is constructed entirely of whole risers. No splitting of risers is required as in a staggered running bond arrangement.
A still further advantage to the present masonry step and deck assembly is that its modular design is readily disassembled for moving to a new location or discarded. The assembly can also be altered or additional sections can be added to enlarge the step and deck assembly. Moving and modifying the assembly can be done by an individual homeowner without the need of motorized equipment or special tools. The assembly can be easily removed from a tight area without disturbing the surrounding. Once installed the design can be readily altered or expanded as desired, such as to add a handicap access ramp.
A still further advantage to the present masonry step and deck assembly is the limited number of differently shaped components that are required to complete any size, shape or height. Only a single riser and four treads are required to construct a wide variety of step and deck designs. This limited number of components provides significant economies in the manufacturing, distribution, retail sales, construction, and repair or redesign of the assembly. During manufacture, there are fewer forms to design, maintain and store. Fewer manufacturing set ups and down times are required to produce a complete assembly. Fewer risers and treads need to be maintained in inventory and tracked during shipping. These savings are again realized at the retail level, where space is limited and expensive. The limited number of components also assists the home owner in designing, hauling and constructing a deck and step assembly for their home.
A still further advantage of the present masonry step and deck assembly is that the treads form a continuous lip around the steps and deck. The lip increases the depth dimension of each step, without requiring an increase in the depth dimension of the risers. The narrower the risers, the more possibilities there are to vary the overall depth of the unitary base. This improves the overall flexibility of the step and deck assembly and the ability to achieve a custom fit for a particular home or building.
A still further advantage to the present masonry step and deck assembly is that the treads provide grooves near the outer edges of each step. These grooves provide traction for a person walking up or down the steps.
A still further advantage to the present masonry step and deck assembly is that it incorporates a continuous, integrated pattern on the walking surface of a step and deck assembly. Each of the four differently shaped treads has a different pattern of grooves formed into its upper surface. The grove pattern is dependent on the specific portion of the walking surface in which it is placed, and the intended overall design of the step and deck assembly. By placing each tread in its specific portion of the assembly, the design of each tread will be integrated with the design of the treads placed in adjacent portions of the assembly. The treads can also be used to form a walkway. Accordingly, the continuous, integrated pattern can be extended from the surfaces of the steps and deck to include the walkway as well.
Other aspects and advantages of the invention will become apparent upon making reference to the specification, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the modular masonry step and deck assembly having three tiers, four rows and six columns to provide a custom fit for a specific house, and with its continuous design extending across the walking surface of the assembly and down a walkway.
FIG. 2 is a perspective view of a first embodiment of a riser with a light slot formed in one longitudinal wall and a wiring notch in the opposite longitudinal wall.
FIGS. 3A-E are perspective, front plan, side plan, rear plan and top views of a second embodiment of the riser with a light slot formed in one longitudinal wall and a vertical groove with an inwardly expanding cross-sectional area formed in each vertical corner.
FIG. 4 is a perspective view of a semi-flexible, locking key having a crossectional area with a clover-like shape.
FIG. 5 is a top view of a clover-shaped locking key inserted into a channel formed by four flushly aligned risers with their side wall surfaces in direct contact.
FIG. 6 is a top view showing a third embodiment of the riser with a light slot formed in one longitudinal wall and a groove having an inwardly expanding cross-sectional area formed at the central point of the other three walls.
FIG. 7 is a perspective view of a semi-flexible, locking key having a crossectional area with an hourglass-like shape.
FIG. 8 is a top view of an hourglass-shaped locking key inserted into a channel formed by two flushly aligned risers with their side wall surfaces in direct contact.
FIGS. 9A-D are perspective, front plan, side plan and top views respecively of a corner tread having a pair of parallel grooves formed into its upper surface along three of its edges.
FIGS. 10A-D are perspective, front plan, side plan and top views respectively of a front tread having a pair of parallel grooves formed into its upper surface near two opposed edges.
FIGS. 11A-D are perspective, front plan, side plan, and top views respectively of a side tread having a pair of parallel grooves formed into its upper surface near one of its edges.
FIG. 12 is perspective view of an inner tread having a smooth surface.
FIGS. 13A-D are perspective, front plan, side plan, and top views respectively of a corner tread having an alternate design with a pair of parallel grooves formed into its upper surface along two of its edges.
FIG. 14 is a perspective view of a partially assembled step and deck assembly showing the placement of the risers and treads and the injection of a foam spray to form one of the semi-flexible locking keys.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
While this invention is susceptible of embodiment in many different forms, the drawings show and the specification describes in detail a preferred embodiment of the invention. It should be understood that the drawings and specification are to be considered an exemplification of the principles of the invention. They are not intended to limit the broad aspects of the invention to the embodiment illustrated.
FIG. 1 shows a house 5 with a concrete foundation 6 , walls 7 and a door or entrance 8 . The door 8 has a threshold 9 elevated a specific height above the level of the ground 10 in an area 15 in front of the door. Several obstructions are located around the door 8 . These obstructions include a tree 21 located to the left of the door 8 , a garden 22 located to the right, a walkway 23 leading to a driveway 24 in front of the house, and the foundation 6 located directly beneath the door 8 . The house 5 also includes structural features such as a window 26 located to the right of the door 8 and a mailbox 28 located to the left. These obstructions and features define the usable area 15 for constructing a step and deck constructions, such as the modular step and deck assembly identified as reference number 30 . While the building is shown to be a house setting on a foundation, it should be understood that the building could also be a mobile home or a portable trailer such as the type found on a construction site.
The modular masonry step and deck assembly 30 includes a unitary base 31 and a walking surface 32 . The assembly 30 has a lower surface 34 that rests on the ground 10 , and a rear surface 35 that abuts a planar surface of the foundation 6 below the door 8 . The assembly 30 has a step portion 36 that includes a plurality of steps 37 located in front of the door 8 , and a deck portion 38 located proximal the door. Although the step portion 36 is shown in front of the door 8 with the deck portion 38 in between, it should be understood that the assembly could be constructed with the step portion located to the right or left of the door.
The unitary base 31 is formed by a plurality of like-shaped risers 50 . The risers 50 are formed of a high strength cementitious material, such as concrete formulated to ASTM specification C-936. Concrete of such specification is designed for use as interlocking paving blocks and has a strength of 8,000 psi. The risers 50 can take several different forms as shown in FIGS. 2, 3 and 6 . Each embodiment 51 , 52 or 53 of the riser 50 includes a main body 61 having a planar top surface 62 that is parallel to its planar bottom surface 63 . The risers 51 - 53 also includes four side walls 64 - 67 , which for the purpose of clarity may be referred to as the front wall 64 , rear wall 65 and opposed side walls 66 and 67 . The front and rear or longitudinal walls 64 and 65 are longer than the side or transverse walls 66 and 67 to give the riser its rectangular shape.
Each side wall 64 - 67 of the riser 50 has a planar outside surface 71 - 74 . Each outside surface 71 - 74 intersects its adjacent outside surfaces and the top and bottom surfaces 62 and 63 at a right angle. The outside surfaces 71 and 72 of front and rear walls 64 and 65 are parallel, as are the outside surfaces 73 and 74 of side walls 66 and 67 . These parallel surfaces 62 - 67 give the rectangular riser 50 a uniform height dimension of about 8 inches from top to bottom 62 and 63 , a uniform width dimension of about 15 and ⅝ inches from side to side 66 and 67 , and a uniform depth dimensions of about 9 and ⅝ inches from front to rear 64 and 65 . The outside surfaces 71 - 74 of the risers have a decorative pattern (not shown) consisting of many closely spaced vertical corrugated ridges. The side walls 64 - 67 have inside surfaces 76 - 79 that define a hollow inner core 80 that passes completely through the riser 50 .
As shown in FIG. 2, the first embodiment 51 of riser 50 includes a first slot 82 for holding a light fixture (not shown). The slot 82 is formed into the top surface 62 of the riser 51 at the center of the front wall 64 . The slot 82 has a sloped lower surface that produces a larger recess in the outer surface 71 and a smaller recess in the inside surface 76 . A notch 83 is formed in the inside recess to accommodate a wire (not shown) of the light fixture. A second slot 85 is located in the top surface 62 toward the center of the rear wall 65 . A notch is formed in the lower surface of the slot 85 for routing the electrical wire to the light fixture. Adjacent outside surfaces 71 - 74 meet to form the vertical corners 90 of the riser 51 .
The second embodiment 52 of the riser 50 is shown in FIGS. 3A-E. Riser 52 includes the slot 82 for the light fixture, but omits slot 85 . The electrical wires can be routed down through the inner core 80 of the riser and underground. Vertical grooves 100 are formed into the corners 90 of the riser 52 . Each groove 100 has an inwardly expanding cross-sectional shape 101 formed by an arcuate shaped wall 102 having a narrow neck 104 near the surfaces 71 - 74 of the riser 52 and a wider circular inner portion 106 formed in the walls 64 - 67 . Each groove 100 maintains this uniform cross-sectional shape 101 as it spans from the top 62 to the bottom 63 surface of the riser 52 . When four risers 52 are aligned in a side-by-side arrangement with their outside surfaces 71 - 74 aligned flush and in direct contact as in FIG. 5, the corner grooves 100 of the risers combine to form a single channel 110 with a cloverleaf-shaped cross-sectional area, each leaf being formed by one groove of each riser.
The third embodiment 53 of the riser 50 is shown in FIG. 6 . Riser 53 also includes the slot 82 for the light fixture, but omits slot 85 . Vertical grooves 120 are formed along the center points of both rear wall 65 and side walls 66 and 67 . Each groove 120 has an inwardly expanding cross-sectional shape 121 formed by angled walls 122 that come together near the surfaces 72 - 74 of the riser 53 to form a narrow neck 124 , and a widening trapezoidal shaped inner portion formed in the walls 65 - 67 . Each groove 120 maintains this uniform cross-sectional shape 121 as it spans from the top 62 to the bottom 63 surface of the riser 53 . When two risers 53 are aligned in a side-by-side arrangement with their outside surfaces 71 - 74 aligned flush and in direct contact as in FIG. 8, the grooves 120 combine to form a single channel 130 with an hourglass-like cross-sectional shape, each half of the hourglass being formed by one groove 120 of each riser.
The risers 50 are dry stacked to form several tiers 150 . The tiers 150 include a ground tier 152 and several stacked tiers 154 , including an upper tier 156 . Each tier 150 is arranged into multiple rows 160 and multiple columns 162 of risers 50 . Each tier has the same number of rows 160 , but the ground tier 152 has the largest number of columns 162 . Each stacked tier 154 is placed atop an immediately lower tier 164 . Each tier 150 has a pair of opposed end rows 165 and 166 and a front column 168 . Each stacked tier 154 has one fewer columns 162 than its immediately lower tier 164 . The stacked tier 154 is staggered from the front column 168 of its immediately lower tier 164 .
Each of the front columns 168 has two opposed corner risers 170 , and a remaining front portion 172 that includes two more risers. The end rows 165 and 166 of the upper tier 156 includes a corner riser 170 . The end rows also include a remaining side portion 174 that includes three more risers. The upper tier also has an interior portion 176 of risers 50 . The rear surface 35 of the assembly 30 is formed by the tiers 150 . This rear surface 35 forms a common planar surface 178 adapted for alignment with the foundation 6 of the building 5 .
The risers 50 forming the unitary base 31 are dry stacked in a stacked-bond arrangement, each stacked riser 50 setting directly atop another. The side wall surfaces 71 - 74 of each stacked riser 50 is in coplanar alignment with the side wall surfaces 71 - 74 of the riser on which it is stacked. Adjacent risers 50 in the same tier 150 are aligned in a side-by-side arrangement with their outside surfaces 71 - 74 in aligned flushly and in direct contact as in FIG. 5 . The corner grooves 100 of the risers 150 combine to form the cloverleaf-shaped channel 110 . Because of the stacked-bond arrangement of the risers 50 , each channel 110 formed by four adjacent risers of a given tier 150 is aligned with the channel 110 formed by the four adjacent risers upon which they are stacked. Accordingly, the channels 110 of each tier 150 combine in a linear manner to form a continuous channel 130 .
A plurality of elongated locking keys 201 or 202 of the type shown in FIGS. 4 and 7 are used to secure the tiers 150 , rows 160 and columns 162 of risers 50 together to form the unitary base 31 . These locking keys 200 are made of a semi-flexible material. While generally maintaining its shape to secure the risers 50 in place, the semi-flexible keys 200 will bend and stretch to a limited degree. The limited amount of bending and stretching allows the risers 50 forming the unitary base 31 to move slightly with respect to each other.
A clover-shaped locking key 201 is used with risers 52 having a vertical groove 100 in the corners of the side walls 64 - 67 as shown in FIG. 4 . An hourglass-shaped key 202 is used with risers 52 having a vertical groove 100 in the center of the side walls 64 - 67 as shown in FIG. 7 . Both keys have a narrow central body portion 204 and an outwardly expanding wider portion or finger 205 . The clover-shaped key 201 has four fingers or lobs 205 . Each finger 205 has a narrow neck portion 210 and a wider outer circular portion 212 . Each finger or lob 205 is shaped to snugly fit into one of the vertical groove 100 of riser 52 . The hourglass-shaped key 202 has a narrow middle portion 220 formed by two parallel walls. Two expanding trapezoidal extensions 222 extend from opposite ends of the middle portion 220 . Each extension 222 has a pair of angled walls 224 that diverge away from the narrow middle portions 220 . extensions 222 extend from opposite ends of the middle portion 220 . Each extension 222 has a pair of angled walls 224 that diverge away from the narrow middle portions 220 .
One locking key 201 or 202 is inserted into each continuous channel 130 . Each elongated locking key 200 extends from the bottom surface 63 of the risers 50 forming the ground tier 152 , to the top surface 62 of the risers forming the upper tier 156 . The locking key 200 may also be formed directly in the continuous channels 130 by injecting a foam spray into the continuous channels. When sprayed from a can as shown in FIG. 14, the foam expands to fill the cavity formed by the continuous channel 130 . The foam spray is believed to be made of a polyurethane intermediate which is made up of polymeric diisocyanate polyols and a hydrocarbon gas mixture.
As shown in FIGS. 9-12, a plurality of like-shaped corner treads 250 , like-shaped front treads, 260 , like-shaped side treads 270 and like-shaped inner treads 280 are place on the risers 50 to form the walking surface 32 . These treads are made of the same masonry material as the risers 50 . Each tread 250 , 260 , 270 and 280 has substantially planar top 251 , 261 , 271 and 281 and bottom 252 , 262 , 272 and 282 surfaces, and front 253 , 263 , 273 and 283 , rear 254 , 264 , 274 and 284 , and opposed side 255 , 265 , 275 and 285 wall surfaces. Each tread has a uniform height dimension from top 251 , 261 , 271 and 281 to bottom 252 , 262 , 272 and 282 . Each of these wall surface is substantially at a right angle to its adjacent wall surfaces.
As best seen in FIG. 14, each corner tread 250 is placed on the upper surface 62 of one corner risers 170 . Each corner tread 250 has uniform width and depth dimensions that is about one inch greater than the respective width and depth dimensions of the like-shaped risers 50 . Two adjacent side wall surfaces of each corner tread 250 are coplanar with two of the side wall surfaces 71 - 74 of the riser 50 on which it is placed. Each front tread 260 has a uniform width dimension that is equal to the width dimension of the risers 50 and a uniform depth dimension that is equal to said depth dimension of the corner treads 250 . Each of the side treads 270 has a uniform width dimension that is equal to the width dimension of the corner treads 250 and a depth dimension that is equal to the depth dimension of the risers 50 . Each of the front and side treads 260 and 270 has three side wall surfaces that are coplanar to the side wall surfaces of the riser 50 on which they are placed. Each inner tread 280 has uniform width and depth dimensions that are equal to the respective width and depth dimensions of the risers 50 . Each of the side wall surfaces 283 , 284 and 285 of the inner tread 280 are coplanar with the side wall surfaces 71 - 74 of the riser 50 on which they are placed.
The corner treads 250 and front treads 260 combine to form a plurality of steps 290 on the front columns 168 of each tier 150 . One corner tread 250 is placed on each of corner risers 170 . One front tread 260 is placed on each of risers 50 in the remaining front portion 172 of the front column 168 . The side treads 270 and inner treads 280 combine to form a deck 300 . One side tread 270 is placed on each of the risers forming the remaining side portions 174 of the upper tier 156 . One of the inner treads 280 is placed on each of the risers 50 forming the interior portion 176 of said upper tier 156 . The non-coplanar side wall surfaces of the corner 250 and front 260 treads extend outward from their respective risers 50 , and combine to form a continuous lip 310 of about one inch around each of step 290 . The corner 250 , front 260 and side 270 treads form the continuous lip 310 around the step and deck of the upper tier 156 .
Parallel grooves 320 are formed into the top surfaces 251 , 261 and 271 of corner 250 , front 260 and side 270 treads. As shown in FIG. 9A, each like-shaped corner tread 250 has three pairs of grooves 320 . One pair of grooves is formed along each of its front and rear edges as well as one side edge to produce a first design 331 . As shown in FIG. 10A, each like-shaped front tread 260 has two pairs of grooves 320 . One pair of grooves is formed along each of its front and rear edges to produce a second design 332 . As shown in FIG. 11A, each like-shaped side tread 270 has one pair of grooves 320 formed along one of its side edges to produce a third design 333 . As shown in FIG. 12, the like-shaped inner treads have a completely smooth top surface to produce a blank design 334 . Alternated designs are possible for the treads 250 , 260 , 270 and 280 . FIGS. 13A-D show a possible alternate design 355 for a corner tread 250 . This alternate design would require the removal of one pair of grooves from the front tread 260 .
As shown in FIGS. 1 and 14, the individual designs 331 , 332 , 333 and 334 of the treads 250 , 260 , 270 and 280 combine to produce a continuous, integral design 340 across the walking surface 32 of the step and deck assembly 30 . By shaping and sizing the treads 250 , 260 , 270 and 280 as noted above, placing the different treads in different predetermined locations such as on corner risers 170 , remaining front portions 172 , remaining side portions 174 and inner portions 176 , and forming the grooves 320 at specific spaced locations from the edges of the treads, a continuous, integral design 340 is produced. The grooves 320 of one tread align integrally with the grooves of adjacent treads to produce the continuous design 340 . By placing corner 250 and front 260 treads on the ground 10 in front of the steps 290 , the design 340 can be continued down an associated walkway 23 .
As shown in FIG. 14, a bed of gravel 360 is spread on the ground in the usable area 15 adjacent the entranceway 8 . A sheet 365 of construction grade expanded polystyrene can placed over the gravel 360 to provide a stable, flat base for the placement of the ground tier 152 of risers 50 . Risers 50 are then positioned to form the base 31 . The weight of the risers is such that they can be lifted and placed in position by hand. Because the assembly 30 incorporates a dry stacked and stacked-bond riser assembly, the number of tiers 150 determines the total height of assembly 30 , the number of rows 160 determines its total width, and the number of columns determines the total depth.
Risers 52 are engaged by pairs of locking key slots to rigidly secure adjacent pairs of risers 90 together. Once the risers 52 have been positioned and locked in engagement with each other by keys 201 , treads 250 , 260 , 270 and 280 are adhered to the top surfaces 62 of the risers 50 with an adhesive 350 to complete formation of the step assembly. Preferably, the adhesive should not become rigid upon curing, but should remain somewhat viscous to accommodate for the varying outside temperature conditions that the adhesive will encounter. A preferred adhesive for use in the present invention is a mastic cement, such as that sold under the name “Paverbond”. A set of railings 370 may be secured to the assembly by expandable fasteners 371 placed into openings 372 drilled into the treads of the assembly 30 .
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the broader aspects of the invention.
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The modular masonry step and deck assembly consists of a plurality of like-shaped risers and a plurality of like-shaped treads that enable the assembly to have a variety of shapes, sizes and heights to provide a custom fit to a variety of buildings, mobile homes or trailers. The risers are dry stacked in a multi-tier, multi-column, multi-row arrangement to form a base of the assembly. An inwardly expanding groove is formed in each corner of each riser. When aligned flush with adjacent risers and dry stacked one atop the other in a stacked bond arrangement, the groves form a continuous vertical channel. A semi-flexible locking key is formed inside the channel to secure the risers together, but accommodate movements caused by the freezing and thawing of the ground. Four differently shaped treads are used to form the walking surface of the step and deck assembly. Each tread shape is used to form a specific portion of the walking surface. A plurality of each like-shaped tread is used to form its specific portion of the walking surface to create a continuous lip around the perimeter of the steps and deck. Each of the four like-shaped treads has a specific design on its top surface to form an integral, continuous pattern on the steps and deck. The treads can be used to continue the design into a walkway.
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BACKGROUND
The technical field of the invention is the field of methods allowing to acquire the coordinates of a trigger point of a projectile on a trajectory and above a field part on which a target is located.
In particular, the invention relates to fire-control systems which can be associated with a weapon firing explosive projectiles, or bursts of such projectiles.
The fire-control systems allow to provide the coordinates of a trigger point for a projectile fired by the weapon.
It is common to implement a fire-control system associating a laser range finder with a ballistic computer. The range finder allows to determine the distance to a target. The computer determines, based on this distance, the elevation and bearing angles to be given to the weapon as well as the programming to be provided to the projectile to be fired, such as the timing to fire the projectile.
The known fire-control systems are particularly well adapted when the target is visible, has a sufficient size and can be easily spotted, thus when the distance to the target can be easily measured.
However, these fire-control systems are unsuited for the acquisition of targets which are small-sized, scattered or temporarily or partially hidden. Indeed, it is almost impossible to find the range of such targets. The operator therefore has to perform several adjustment fires so as to determine the correct distance to trigger projectiles.
SUMMARY
The invention is intended to provide a method for acquiring the coordinates of a trigger point of a projectile, the method allowing to immediately engage with a high probability of interception a target of a small-size, scattered or hidden.
Thus, the invention relates to a method for acquiring the coordinates of a trigger point of a projectile or of a burst of projectiles on a trajectory and above a field part on which a target is located, characterized in that the method comprises the following steps:
emitting from a laser source at least one laser pulse having a determined duration and directed towards the field part where the target is located,
receiving the images reflected by the field part with a receiver equipped with means for the synchronous visualization of the reflection of the laser pulses under the form of a piece of observation of the field part, the piece having a width which can be possibly modified by selecting a duration for the laser emission or reception, and the distance of the piece of observation with respect to the receiver can be modified by adjusting a delay between the emission and the reception of the laser pulse,
recovering the coordinates of a desired trigger point by the operator when the operator has chosen a suitable location after having moved the piece of observation with respect to the receiver and possibly adjusted the width of the piece, the trigger point being within said piece.
Advantageously, the width of the piece will be chosen substantially equal to the depth of an area of effectiveness of the projectile or burst.
According to a particular embodiment, an image of the piece observed will be displayed on means for visualization intended for an operator, the image comprising a superimposed image of the area of effectiveness of the projectile or burst, when fired at a trigger point associated with said area of effectiveness and positioned within the piece of observation, the operator having the option to move the area of effectiveness with respect to the image of the piece, the coordinates of the trigger point being determined after the area of effectiveness was moved.
The invention also relates to a fire-control system which can be associated with a weapon firing projectiles or bursts of projectiles and allowing to provide the coordinates of a trigger point for a projectile or a burst fired by the weapon, the fire-control system implementing the method according to the invention and characterized in that the fire-control system comprises:
at least one synchronized pulses laser observation means associating a laser source or emitter which can emit pulses having a determined duration with a receiver equipped with means for the synchronous visualization of the reflection of the laser pulses under the form of a piece of observation of the field part having a width which can possibly be modified by selecting a duration for the laser emission or reception, and whose distance with respect to the receiver can be modified by adjusting a delay between the emission and the reception,
a computer which can rebuild, using a suitable algorithm, an image of the piece of observation acquired by the observation means, the image being displayed on a means for visualization,
first control means intended for a user and allowing to position and move said piece of observation at a greater or shorter distance from the observation means,
second control means allowing the operator to position and move, on the image of the piece observed, a superimposed image of an area of effectiveness of the projectile or burst, when fired at a trigger point chosen in the piece of observation,
the computer continuously determining the coordinates of the trigger point associated with the area of effectiveness and positioned within the piece when the operator activates the first and second control means to move the piece of observation and the area of effectiveness,
validation means allowing the user to choose a particular location of the area of effectiveness, the computer thus providing the coordinates of the desired trigger point for the projectile or burst.
According to an embodiment, the receiver is a camera equipped with a shutter synchronized with the laser emission and opening the camera at the end of at least one delay determined with respect to the emission, the delay between the emission and the reception allowing to adjust the distance of the piece of observation with respect to the receiver.
According to an embodiment, the synchronized shutter also allows to adjust the width of the piece of observation.
The image of the area of effectiveness can advantageously be semi-transparent.
The image of the area of effectiveness can have a color different from the color of the rest of the image.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood upon reading the following description of a particular embodiment, the description being made in reference with the appended drawings in which:
FIG. 1 shows a field part on which targets are located, and a vehicle equipped with a weaponry system and a fire-control system according to the invention,
FIGS. 2 a and 2 b depict the operation of an observation means used by the invention,
FIG. 3 shows an image of the field such as viewed by the gunner from a conventional camera without implementing the invention,
FIG. 4 depicts the tomographic acquisition of image planes of the field,
FIG. 5 is a diagram showing the architecture of the fire-control system according to the invention,
FIG. 6 shows an image of the field after implementation of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
When referring to FIG. 1 , it is shown a field part 1 on which is located a vehicle 2 provided with a turret 2 a carrying a gun barrel 3 .
The gun barrel 3 is intended to fire explosive projectiles 4 towards targets 5 a , 5 b , 5 c scattered on the field 1 . Only one projectile 4 is shown here on its trajectory 6 .
The gun barrel 3 can be oriented in elevation and in bearing with respect to the vehicle. Thus, the turret 2 a can rotate about a vertical axis (bearing setting) and the barrel 3 can pivot with respect to the turret 2 a along a substantially horizontal axis (elevation setting). Suitable motorizations are associated with these elevation and bearing adjustments of the gun barrel 3 .
The turret 2 a also carries observation means 7 constituted here by an active laser sensor 7 , associating a laser emitter with a receiver and allowing to synchronously visualize the reflection of the laser pulses under the form of a piece of observation of the field.
These active-imagery sensors implement the technology known as “Sliding Range Gating”.
FIGS. 2 a and 2 b schematically show the structure of such a sensor 7 and the operation thereof.
The sensor or observation means 7 comprises a laser 20 (emitter) operating in the range of wavelengths from 1.06 micrometers to 1.54 micrometers. This laser 20 emits pulses towards a target 5 and is controlled by control electronics 21 . The control electronics 21 allows to pilot the duration of the pulses 23 which are emitted. The duration of the pulse allows to define the width δ of a piece of analysis T of the field.
The sensor or observation means 7 also comprises a camera 22 (or receiver) driven by the control electronics 21 . The camera comprises a shutter (not shown) synchronized with the laser emission and which opens the camera at the end of at least one delay R determined with respect to the emission of the pulse 23 . The shutter is driven by the control electronics 21 .
This delay R corresponds to the duration necessary for the light to travel twice the distance D separating the sensor 7 from the target 5 , the delay between the emission and the reception allowing to adjust the distance between the piece of observation T and the receiver 22 , thus between the piece T and the sensor 7 .
Thus, the camera 22 is closed to all lights backscattered by the field and by the pulse 23 , and is opened only to receive a part 24 of the pulse 23 reflected by the target 5 .
With this technique, it is thus possible to acquire, by the observation means 7 , images from a piece T of field with a width δ and located at a distance D from the sensor 7 . The distance D and the width δ can be modified by the operator.
According to another embodiment, it is possible to implement a laser 20 emitting pulses, the duration of which allows to define a width greater than the width δ desired for the piece of analysis T of field. In this case, this radar will be associated with a camera or receiver 22 equipped with a shutter, synchronized with the laser emission but having an opening duration allowing to keep only the signals relating to a piece of field with a width δ. In this case, the shutter allows to define both the width δ (by its opening duration) and the distance D (by the delay R between its opening and the laser emission).
The observation means 7 is coupled to a fire-control system (not shown in FIG. 1 ) which is within the turret 2 a and allows to control the motorizations ensuring the laying of the turret 2 a and of the barrel 3 of the weapon towards the targets 5 a , 5 b , 5 c.
The fire-control system will also ensure the programming of projectiles fired by the barrel. This programming comprises the configuration, by a (conventional and not shown) programming interface, in a memory of the projectile fuze, of a projectile triggering time at the end of the firing time.
The targets 5 a , 5 b , 5 c have small sizes, for example lightweight vehicles or groups of combat soldiers.
The targets are further partially hidden with respect to the vehicle 2 by landscape elements, such as trees 8 a , 8 b , 8 c , the foliage of which is not entirely opaque to the light.
The observation section of the observation means 7 is shown in FIG. 1 by a dotted-line cone. Thus, the observation means 7 faces the field along a direction S 1 which corresponds to the axis of the cone 9 .
FIG. 3 shows the image of the field 1 as it is directly displayed on a screen of the fire-control system from a conventional camera which does not implement the invention.
It can be noted that the targets 5 a , 5 b and 5 c are partially hidden by the trees 8 a , 8 b and 8 c . A range finding of the targets from the fire-control system is thus difficult or even impossible.
The trees 8 a , 8 b , 8 c intercept the signals of laser range finding, resulting in a bad programming of the triggering time of the projectile 4 on its trajectory.
A programming error results in a significant reduction of the hit probability. For firing a burst of ten projectiles at a distance of 1,200 meters, it was shown that a programming error of 10 meters results in a reduction up to 50% of the hit probability.
In addition, if the foliage is not entirely opaque, the targets 5 a , 5 b and 5 c are viewed with a maximum signal/noise ratio because the light backscattered by the foliage is not detected by the camera 22 , the shutter inhibiting the reception of the backscattered light.
FIG. 4 shows the operational implementation of the method according to the invention.
With this method, the observation means 7 described above will be used to observe only the radiations reflected by the objects located in a piece T of field with a width δ which is located at a distance D from the observation means 7 . This piece T is materialized in FIG. 4 by two planes 10 a and 10 b . Thus, the vision of the target 5 a , 5 b , 5 c is less hidden by the obstacles located between the vehicle and the target, such as the trees 8 a , 8 b , 8 c.
FIG. 5 shows a fire-control system 11 according to the invention.
This fire-control system 11 is intended to provide the coordinates of the trigger point P for the projectile 4 on its trajectory.
The fire-control system comprises the laser observation means 7 which allows to observe pieces T of the field 1 observed, and the thickness 5 and the distance D of the pieces can be adjusted by the operator. The value of the width δ of the piece T is adjusted by modifying the duration of each emitted (or received) pulse.
The distance D is adjusted by the operator by modifying the delay between the emission and reception of the laser pulse, thus the delay after an emission of pulse 23 and at the end of which the optics of the camera 22 is opened to receive the reflected pulses 24 .
As mentioned above, it is also possible to adjust the width δ by the opening duration of the synchronized shutter of the camera 22 .
Advantageously, for the piece T, a fixed value of the width δ will be chosen, which corresponds to the depth of an area of effectiveness of the projectile 4 . Such an arrangement allows the operator to determine more easily the optimum trigger point for the projectile by varying only the observation distance D.
The fire-control system also comprises a computer 12 which handles the functions of the control electronics 21 of the observation means 7 .
The fire-control system 11 also comprises first control means 25 which are, for example, a rotating thumbwheel allowing to adjust the value of the delay R between the emission and the reception, and therefore to modify the distance D by moving the piece of observation T.
During this operation for modifying the distance D, the operator can observe, on means for visualization, such as a screen 14 , the presence of potential targets.
FIG. 6 shows what is seen by the operator on the screen 14 after implementing the synchronized-opening observation means 7 . The targets 5 a , 5 b and 5 c are not hidden anymore by the trees 8 .
FIG. 6 shows a plane view projected on the plane of the figure. It is well understood that the screen 14 of the fire-control system allows to view an image of the piece of field in relief.
The fire-control system 11 also comprises second control means 15 implemented here as a lever (or joystick) which can be maneuvered along two orthogonal directions J 1 and J 2 .
Once an acquisition piece T is chosen, the user uses the joystick 15 to position and move, on the image of the field 1 , the image of an area of effectiveness 16 ( FIGS. 1 and 5 ).
This area 16 is an image, built by the computer 12 , of a geometrical volume or surface which allows to view the volume or surface area of effectiveness of the fragments generated by the projectile when fired at a trigger point P ( FIG. 1 ).
This area of effectiveness is shown in the figures as a cone or as its elliptical sections to simplify the description. It is well understood that the volume, which will be superimposed on the image of the field, can have a different shape which will depend on the characteristics of the projectile 4 implemented. The geometrical characteristics of the area of effectiveness 16 associated with different trigger points P are incorporated in memory means 17 coupled to the computer 12 .
It is common, during the definition of a projectile, to measure the distribution of fragments generated by the explosion of the projectile at different distances from the projectile.
Then, the area of effectiveness 16 of a projectile 4 , initiated at a given point P, can be geometrically modeled and constitute a database allowing to associate different areas of effectiveness 16 with different initiation points P.
Thus, each movement of the area of effectiveness can be automatically associated, by the computer 12 , with coordinates of an associated initiation point P.
For simplification purposes, the geometrical volume of the area 16 will be chosen such that it corresponds to a distribution of the fragments generated, allowing to ensure a given hit or neutralization probability. Such a probability corresponds, for example, to a minimum energy level for the fragments and/or to a minimum fragment density.
It is understood that the data are for a given type of projectile and do not depend on the characteristics of the field 1 and of the targets located therein.
A geometrical volume 16 can thus be systematically associated with any point in space, the geometrical volume 16 corresponding to the desired hit probability when the projectile 4 is initiated at this point.
According to the invention, this volume is moved by the user on the bi-dimensional or three-dimensional image of the field 1 . This image of the area of effectiveness 16 is semi-transparent and does not hide the potential targets 5 a , 5 b and 5 c . It also could have a color different from the color of the rest of the image so as to facilitate its visualization.
The width of the piece T being chosen equal to the depth of effectiveness of the projectile, it is just necessary to suggest to the operator a surface or volume 16 giving the shape of the area of effectiveness in the considered piece T.
Thus, the user can easily move, using the joystick 15 , the area of effectiveness 16 along the directions D 1 and D 2 ( FIG. 6 ). It allows the user to visually determine the position allowing to neutralize one or more targets 5 a , 5 b , 5 c with the desired hit probability.
When moving the area 16 using the joystick 15 , the computer 12 continuously determines the coordinates of the trigger point P corresponding to the position chosen for the area of effectiveness 16 . Indeed, these coordinates are closely related to the geometry of the area 16 which is moved, and a movement of the area 16 corresponds in fact to a movement of the point P, the data being associated in the memory means 17 .
The piece T having a width equal to the width of the area of effectiveness, the point P is located in a plane located in the middle of the piece, within equal distance from the planes 10 a and 10 b.
When the user has chosen a particular location for the area of effectiveness 16 , he/she activates validation means (for example, a control switch B 1 of the joystick 15 ).
The computer 12 thus provides to a laying module and a programming module 19 the coordinates of the desired trigger point P for the projectile, that was read in the memory means 17 .
These coordinates are conventionally used by the laying module 18 to control the elevation and bearing layings of the gun barrel 3 .
The coordinates are used by the programming module 19 to program the triggering time of the projectile 4 on the trajectory.
The invention was described for simplification purposes with respect to a use for controlling the firing of a single projectile.
The invention can be implemented in a similar way for controlling the firing of a burst of projectiles. A burst comprises a number of projectiles (4 to 10 for example) successively fired at the rate of fire of the weapon.
As it is possible by conception to define an area of effectiveness of a single projectile, it is also possible to geometrically define an area of effectiveness of a burst comprising a number of projectiles of a given type.
The means of the invention are implemented in the same way as described above.
However, what is visualized on the screen is not the area of effectiveness of a single projectile anymore, but the area of effectiveness of a burst. The trigger point P thus corresponds to a mean point, the barycenter of the trigger points of the different projectiles of the burst. Based on the selection of the area of effectiveness, a burst ensuring an initiation, with a statistical distribution of the initiation times of the projectiles of the burst in the considered piece, can also be defined in the fire-control system.
Once the area of effectiveness is positioned by the user, the computer 12 transmits as previously to the laying module 18 and the programming module 19 the different firing parameters (laying angles) and burst managing parameters (programming of the triggering time of each projectile).
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The invention relates to a method for acquiring the coordinates of a trigger point (P) of a projectile ( 4 ) above a field part ( 1 ) on which a target ( 5 a, 5 b, 5 c ) is located. The method is characterized in that it comprises the following steps: emission of at least one laser pulse having a pre-determined duration and directed towards the target ( 5 a, 5 b, 5 c ); reception of the images reflected with a receiver equipped with means for the synchronous visualization of the laser pulses originating from a piece of observation of the field part ( 1 ); recovery of the coordinates of a desired trigger point (P) when the operator has chosen a location after the piece of observation was moved. The invention also relates to a fire-control system using such a method.
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BACKGROUND OF THE INVENTION
This invention relates to the acquisition, at different levels in a borehole, of seismic signals generated by a source placed in the vicinity of the surface opening of the borehole.
When the seismic waves produced by a source are recorded by means of a detector at different levels in a borehole, a series of seismic signals is obtained which are gathered, after suitable processing, to form a vertical seismic profile. The analysis of such a profile provides precious information on the structure of the geological formations traversed by the borehole, and notably on the position and the dip of the reflecting layers, including those which are located at a depth from the surface greater than the borehole bottom.
For a complete analysis, the recordings must be carried out at a very large number of different levels, for example 200 or more. This takes a very long time, especially as several measurements are carried out at each level in order to improve the quality of the signals.
SUMMARY OF THE INVENTION
The present invention aims to accomplish the acquisition of seismic signals in a borehole in an optimum manner relative to both the speed of acquisition and the quality of the signals acquired.
The object of the invention, according to one aspect, is a method for seismic signal acquisition at successive levels in a borehole, comprising the following operations:
(i) to a first level is lowered, by means of a cable, a sonde comprising an elongated body member, seismic wave detection means and an anchoring pad placed at the end of a support arm articulated on the body member and subject to extension under a spring force, said arm being maintained in the retracted position substantially along the body member during the lowering;
(ii) at a desired level, in the borehole, the arm is deployed to place the pad in contact with the borehole wall;
(iii) through the arm, a force is applied capable of anchoring the pad to the wall;
(iv) a seismic wave source is actuated to produce at least one detection signal;
(v) through the arm, a force is applied capable of releasing the pad from its anchored position on the wall;
(vi) the sonde is raised by means of the cable to another level, the pad remaining in contact with the wall under the action of the extended arm; and
(vii) the sequence of operations (iii) to (vi) is repeated for the next levels.
By keeping the support arm in the extended position during the movements between successive levels a significant time saving is effected since it is thus possible to avoid having to retract the arm at the end of the measurements at one level and to extend it upon reaching the next level.
This characteristic of the arm extension mechanism is moreover exploited to obtain a log of the formations during these movements from level to level, for example a microresistivity measurement may be obtained by means of an electrode placed on the pad which remains constantly in contact with the wall. This additional measurement makes it possible to determine accurately the depth of the different seismic measurement levels, by, for example, correlation between this log and other logs carried out in the same borehole.
According to another aspect, it is the object of the invention to provide a sonde for seismic signal acquisition at different levels in a borehole, comprising:
an elongated body member;
seismic wave detection means placed in the body member;
a pad designed to be anchored in the borehole wall;
a pad support articulated on the body member and capable of occupying a retracted position substantially along the body member;
an elastic device acting to extend the pad away from the body member;
a drive device capable of furnishing a torque in both directions of rotation;
a clutch drive mounted at the output of the drive device; and
a transmission device mounted between the output of the clutch device and the pad support to extend the pad away from or retract it toward the body member according to the direction of the torque.
In accordance with one aspect of the invention the force which is applied to the pad, through its support, is effected by means of a drive device placed in the body. This force, exerted on the pad, is constantly measured by means of a force transducer placed in the pad, and the drive device is stopped when the force value thus measured reaches a given value. Preferably this value is selected to be equal to about twice the weight of the sonde in air.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject invention will be better understood through the following description given with reference to the appended drawings.
In the drawings:
FIG. 1 represents an installation for seismic prospecting in a borehole;
FIG. 2 illustrates in a larger scale the seismic acquisition sonde represented in FIG. 1;
FIG. 3 is a schematic view of the sonde anchoring section;
FIG. 4 illustrates, in axial section, the anchoring section device;
FIG. 5 illustrates a detail of the coupling device;
FIG. 6 represents the articulation of the anchoring arm on the sonde;
FIG. 7 is a section along the plane VII--VII of FIG. 6;
FIG. 8 is a longitudinal section of the anchoring pad;
FIG. 9 illustrates the force transducer housed in the pad;
FIG. 10 illustrates the electrode device housed in the pad.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 is represented an exploratory borehole 10 going through geological formations. A seismic wave source 11 such as an air gun is placed on the surface with a certain offset in relation to the surface opening or head of the borehole. The seismic shocks produced by the source are detected by means of a seismic acquisition sonde 12 lowered into the borehole.
The sonde 12 is suspended from the end of an electric cable 13 which runs over pulleys on the drilling tower 14 and is wound on a winch 15 carried by surface equipment 16. The surface equipment furnishes the sonde 12, through the cable 13, with electric power supply and control signals necessary for its operation. The returning seismic signals produced by the sonde are carried to the surface by the cable and recorded by the surface equipment. A device shown schematically at 17, associated with the winch 15, measures the travel of the cable and makes it possible to determine the depth of the sonde in order to match each seismic signal recorded with the depth of the sonde during the recording.
As illustrated in FIG. 2, the sonde 12 comprises essentially for sections; a detection section 20, an anchoring section 21 over the section 20 designed to enasure proper coupling of the detection section with the geological formation, an upper electronic cartridge 22 connected to the cable by a connection head 23, and an electronic cartridge 24 forming the lower end of the sonde. The cartridge 24 is connected electrically to the head 23 and contains circuits for the pre-processing of the detection signals produced by the section 20 and a telemetering device constituting the interface with the cable 13 for signal transmission. The upper cartridge 22 furnishes the power supply voltage to the anchoring section according to the signals addressed by the surface equipment and by other sections of the sonde.
The detection section 20 comprises at least one detector such as a geophone or an accelerometer. In a suitable manner are provided three such detectors placed in a triaxial configuration.
To obtain signals of satisfactory quality, it is indespensable to couple the detection section of an optimum manner with the formation. To accomplish this, the anchoring section comprises a pad 30, designed to be anchored to the borehole wall, carried by two arms 31 and 32 articulated on the sonde body member and at least substantially parallel. On the side opposite the anchoring pad, the detection section and the cartridge 22 include respective bearing elements 33 and 33a furnishing a suitable contact surface with the wall.
FIG. 3 is a functional diagram of the anchoring section. The anchoring force is transmitted to the pad 30 through the lower arm 31. The swiveling of the arm 31 is produced by the travel of an actuating rod 34. The connection between the arm 31 and the rod 34 will be described in detail below. The anchoring force is furnished by a reversible asynchronous motor 35 of the torque motor type equipped with an output reducer 36 and an electromagnetic brake 37 active in the absence of current. The output shaft 38 of the reducer 36 is connected via a coupling device 39, which will be described in detail below, to a ball screw 40 engaging with a nut 41 which drives the actuating rod 34. In addition, a loading device 43 loads the arms 31, 32 constantly in their outward extension direction.
Also shown schematically in FIG. 3 is a potentiometer 44 which makes it possible to measure the movement of the nut 41 and hence the distance between the anchoring pad and the sonde, this distance being indicative of the borehole diameter.
Joints 45 allow the travel movement of the rod 34 while preventing ingress of drilling mud into the internal space 46 containing the motor assembly 35-38, the coupling device 39 and the screw-nut system 40-41. A pressure compensation device 47 of a well known type in logging soundes is placed at the lower end of the anchoring section. Its function is to place the internal space 46 in pressure equilibrium with the drilling mud. Pressure on the opposite faces of the joints 45 is thus substantially the same.
The coupling device 39 as represented in FIG. 3 comprises essentially a clutch device 50, a mechanical logic 51 controlling clutch engagement or disengagement according to the direction of rotation of the motor and the forces exerted on the pad, a spring 52 and a stop 53, and a torque limiter 54.
These elements will be described in detail below with reference to FIGS. 4 and 5.
In FIG. 4 is shown the reducer 36 and its output shaft 38, on one side, and the end of the ball screw 40 on the opposite side. Also shown is the external sheath 55 forming part of the sonde body member and a tubular envelope 56 attached to the sheath 55.
The shaft 38 includes a splined portion 57 and an end portion 58 of smaller diameter which is threaded.
On the end of the shaft 38 is screwed a ring 60. A bushing 61 slidingly surrounds the ring 60 and includes splines 61a engaging with the splines of the shaft portion 57; the bushing 61 being up against the case of the reducer 36. The ring 60 and the bushing 61 thus rotate with the shaft 38. A pin 62 goes through the bushing 61 and into a groove 63 formed on the periphery of the ring 60. This pin allows the extraction of the bushing 61 when the ring 60 is unscrewed.
Around the bushing 61 is placed a clutch sleeve 65. The sleeve 65 is connected to the bushing 61 by the engagement of two diametrically opposite rollers 66 mounted on respective studs 67 fixed on the sleeve 65. The studs 67 are fixed in respective helical cam slots 68 formed in the outer periphery of the bushing 61. FIG. 5 shows, in a developed view, the form of the slots 68. Each cam slot 68 comprises two sections 68a, 68b symmetrical with respect to a generatrix G of the bushing. The sections 68a, 68b meet on the side of the drive shaft in the central portion 68c. The preferred value for the angle between the cam slot sections 68a and 68b is about 90°, as shown in FIG. 5.
Means are provided for blocking the rotation of the sleeve 65 when its axial position is within a given range so that the rotation of the shaft 38 and hence of the bushing 61 causes the traveling of the sleeve 65. For this purpose, the sleeve 65 includes, on the drive side, a part 70 of smaller outer diameter than the part which carries the studs 67. In the annular space thus provided between the sleeve and the fixed envelope 56 is placed a friction ring 71 connected in rotation with the sleeve 65 but mobile axially in relation to this sleeve. The ring 71 includes, internally, an axial keyway 72 into which is engaged a key 73 fixed on the sleeve 65. The friction ring 71 has an outer surface 74 of spherical form, and the inner surface of the envelope 56 opposite the ring 71has a truncated part 75. A helical spring 77 is mounted between the shoulder terminating the small-diameter part 70 and the frinction ring 71. When the surfaces 74, 75 are in contact, as shown in FIG. 3, the friction due to the force exerted by the spring 77 is such that the sleeve 65 is prevented from turning with the bushing 61. A rotation of the bushing 61 will then cause the sleeve 65 to travel.
Furthermore, a circlip 80 is mounted in a groove in the vicinity of the reducer side end of the sleeve 65. This circlip is used to push the friction ring 71 against the action of the spring 77 after a certain axial movement of the sleeve, thereby providing a lost motion-connection between the ring 77 and the sleeve 65. The movement of the ring 71 resulting therefrom causes the friction between the surfaces 74, 75 to disappear and enables the sleeve 65 to be driven in rotation by the shaft.
Moreover, an electric contact 82 connected to the tubular envelope 56 is placed in the vicinity of the reducer 36. This contact is actuated by the sleeve 65 when the latter occupies its end position near the reducer. The pulse produced by this contact serves to cut off the power supply of the motor 35.
The sleeve 65 includes, at its end opposite the reducer, a toothed plate 85 designed to mesh with a toothed plate 86 formed on a counter-ring 87. The toothed plates 85 and 86 comprise radial teeth of triangular section.
The counter-ring 87 is mounted rotatably around a splined bushing 88 rotable with the screw 40, whose end 89 comprises corresponding splines. Stop circlips 90 and 91 are mounted respectively on the screw 40 and on the bushing 88 to serve as an axial stop respectively for the bushing 88 and the counter-ring 87.
On the opposite side, the radial surface of the counter-ring 87 is separated by a small clearance from a collar 92 extending the bushing 88 radially. The collar 92 comprises a plurality of axially directed holes 95 each of which receives a ball 96, and the counter-ring 87 comprises similarly a plurality of radial grooves 97 into which the balls 96 penetrate respectively. Each of the balls 96 is loaded elastically against the bottom of the corresponding groove 97 by a helical spring 98 bearing on a U-section ring 99, this ring being blocked in rotation in relation to the bushing 88. The ring 99 is positioned axially by an adjustment ring 100 screwed on the threaded outer surface of the collar 92 and comprising a radial portion 101 in contact with the ring 99.
The assembly made up of the bushing 88, the balls 96 and the elements 98-100 constitutes the above-mentioned torque limiter. In fact, the balls 96 maintained against the bottom of the grooves 97 by the action of the springs 98 transmit normally the torque of the counter-ring 87 to the bushing 88. However, after a certain value, the balls move away from the bottom of the grooves, compressing the springs 98, and the torque is no longer transmitted.
A ring 105 is screwed on a threaded part 106 of the screw 40, following the end 89. The ring 105 comprises successively, from the end of the screw, a small-diameter portion 107 which, with its radial end face, forms a stop for the bushing 88 and constitutes the stop 53 mentioned above with reference to FIG. 3, an intermediate-diameter portion 109 and a larger-diameter part 110 which serves as a support for the helical spring 52 also mentioned above, said spring acting on the radial portion 101 of the adjustment ring 100, and hence indirectly on the counter-ring 87 carrying the toothed plate 86.
The screw-nut system 40, 41 has no particular feature requiring a detailed description. The nut 41 is, in a classical manner, required to move only in translation, so that a rotation of the ball screw 40 in one direction causes a translation of the nut 41 in the corresponding direction.
FIGS. 6 and 7 show in greater detail the articulation of the arms 31 and 32 on the sonde. The upper arm 32 is connected to the sonde body member 29 by a pivot 110. The lower arm 31 which transmits the forces to the pad 30 is made up of two identical parallel side plates connected by spacers such as 109, which are extended by identical hooks 111, 112 spaces away from each other. The hooks 111, 112 are traversed by a pivot 113 connected to the sonde body member, the pins of the pivots 110 and 113 being perpendicular to the axis of the sonde and equidistant from this axis.
The hooks 111, 112 surround, at their end, a part 115 of the actuating rod 34, said part comprising flat portions 116 parallel to the pivoting plane of the arm 31. On each side of this part 115 are fixed rollers 121. The hooks 111, 112 each comprise an elongated slot 123 engaged around a roller 121 so that a movement of the rod 34 causes a swivelling of the arm 31 around the axis 113. In FIG. 6, the solid line represents the maximum extension position of the arm 31 and the broken line the retraction position.
The walls 124, 125 of the slots 123 in contact with the rollers 121 have substantially the form of circle involutes. An involute is the geometrical locus of a point of a line D which rolls without sliding on a circle C. In the present case, the line D is the axis of the rod 34 and the circle C is centered on the center of rotation of the arm 31, i.e. the axis of the pivot 113, and tangent to the axis of the rod 34. During the rotation of the arm 31, a point connected to the rod 34 and in contact with a side plate of the arm 31 will thus describe an involute. These curves have the property of having a tangent which is constantly perpendicular to the line D, i.e. in this case to the rod 34. The advantage is that a force can be transmitted to the arm without introducing any radial component of the actuating rod 34.
It will also be noted, with reference to FIGS. 6 and 7, that a leaf spring 43a forming part of the loading device 43 mentioned above is fixed on the sonde body member 29 in the vicinity of the pivot 110 of the upper arm 32 and that it passes between the hooks 111, 112 of the arm 31. Further, the rod 34 traverses, on each side of the engagement zone with the arm 31, cases 125, 126 within which are mounted the joints 45 mentioned above. The oil placed under the pressure of the drilling mud by the compensation device 47 can flow up to the end of the rod 34 through a central passage 127.
Also represented in FIG. 6 are conducted 130 carried by the arms 32, which connect the pad 30 to the cartridge 22 and, in FIG. 7, sheaths 131 receiving the electrical conductors which connect the cartridge 22 to the detection section and to the anchoring section, notably for the control of the motor 35.
FIG. 8 shows the arrangement of the loading device 43. The leaf spring 43a mentioned above with reference to FIG. 6, which is fixed at one end to the sonde body member, acts through its opposite end 133 on a web part 134 of the arm 31 placed between the side plates, a relative sliding between the end 133 and the part 134 occurring during the swiveling of the arm 31. A second spring 43b, made up of a single leaf and hence lighter than the spring 43a, is fixed by one end 135 to another web piece 136 of the arm 31, placed closer to the pivot 113 than the part 134. The other end 137 of the spring 43b acts on the upper arm 32 in the vicinity of its end, also with a sliding when the arms swivel.
FIG. 8 shows in greater detail the anchoring pad 30. The pad 30, as was seen, is mounted at the end of the upper arm 32 and the lower arm 31, only one side plate of which is shown in the sectional view of FIG. 8, said side plates surrounding the pad.
The pad 30 comprises a hollow body 140 on the inside and a wear plate 141 intended to come into contact with the wall, fixed on the pad body 140. The wear plate 141 is provided on its surface with grooves in order to optimize its anchoring in the wall.
The pad body 140 is connected to the upper arm 32 by a pivot 142. It also comprises, substantially in its middle, openings 143 made in its side walls. The openings 143 have the form of rectangles with rounded apexes, and receive a pivot 144 connected to the side plates of the lower arm 31.
A force transducer, designated as a whole by the reference 150, is housed in the pad body 140. This transducer, shown in greater detail in FIG. 9, has strain gauges as its sensitive elements. It includes a pressure-resistant sheath 151 of rectangular section within which is placed a bending element 152 carrying the strain gauges 153.
The sheath 151 is extended on the upper side by two side plates 154 provided with holes 155 which snuggly receive the pivot 144 connected to the arm 31. The sheath 151 also has, roughly in its middle, two rollers 158 engaged in elongated slots 159 formed in the lateral walls of the pad body. In the vicinity of its lower end, the sheath 151 has a hole 160 in which is engaged a rod 161 whose ends penetrate respectively into the slots 159.
Summarizing, the pad body 140 is mounted swivelably in relation to the upper arm 32 and it is connected to the lower arm 31 through the force transducer 150 which, on the one hand, can move in translation relative to the pad body and, on the other, is connected to the arm 31 by the pivot 144, the clearance between the pivot 144 and the pad body being limited by the edges of the openings 143 formed in the pad body. The result is that the pad has the possibility of rocking slightly in one direction or the other in relation to the middle position, parallel to the axis of the sonde, which is that shown in FIG. 8. When the pad moves away from its middle position, the upper arm 32 swivels slightly in relation to the sonde while moving away from its position parallel to the lower arm 31.
This ability to rock enables the pad 30 to mate closely with the borehole wall even if this wall has an irregularity at the point of contact with the pad. This is advantageous for obtaining good anchoring. In addition, the forces on the pad will be distributed regularly over its entire surface so that the measurement carried out by means of the force transducer, which is related to the force at the level of the pivot 144, will be representative of the force on the entire pad.
It will be noted that the design of the loading device, with the two springs 43a and 43b, eliminates the risk of the arm-pad assembly jamming in the retracted position which could have resulted from the rocking of the pad.
As concerns the force transducer, it should be indicated that the bending element has a lower end 165 similar to a ball joint engaged in the bottom of the recess formed inside the sheath 151. The strain gauges 153 are placed on inclined flat portions 166 formed on the opposite sides of the bending element. On each flat portion are placed two gauges, and the four gages are connected in a "complete bridge" arrangement in a manner which is customary in the technique of strain gauge measurements. The bending element has conduits such as 167 for the passage of electric conductors 168 connecting the circuit of the gauges to four connectors 169 (two for the power supply and two for transmitting the detection signal) which go through a sealing block 170 fixed to the sheath 151. Conductors, not shown in FIG. 8 and carried by the arm 32, connect these connectors to the electronic cartridge 22.
The force transducer thus inserted into the pad furnishes an indication of the actual force on the pad. The measurement of the anchoring force furnished by the transducer gives excellent reproducibility because, since what is involved is a measurement made directly at the level of the pad, the error factors are minimized. This measurement is used for stopping the operation of the motor 35 when the anchoring force has reached a given value considered as satisfactory. This value is chosen in a suitable manner equal to about twice the weight of the sonde in air.
In addition, the measurement value furnished by the transducer is transmitted via the cartridge 24 to the surface equipment, making it possible to monitor the quality of the anchoring during the series of firings carried out at the same level. It may occur, particularly in soft formations, that the anchoring force decreases after a few firings. Thanks to the transducer mounted on the pad, this decrease will be detected and it will be possible to remedy the situation by restarting the motor, which will stop automatically once the anchoring force has come back to the desired value. Such a possibility is of great value considering the fact that, as was seen, the anchoring force is an essential parameter for the quality of the seismic detection signals.
The pad also has a devide 180 designed to emit an electric current to evaluate the resistivity of the surface zone of the formation traversed by the borehole. This device, shown in greater detail in FIG. 10, includes an electrode 181 in conducting material placed on an insulation 182 itself contained in a hollow of a support 183 in conducting material acting as a ground. This support has a conduit for the passage of an electric conductor 184 connected to the electrode 181. The return of the electric current thus emitted can be effected by the connection head 23 connecting the cartridge 22 to the cable 13. It is thus possible to obtain a microresistivity log which may be correlated with other logs carried out in the same borehole to determine accurately the depth of the anchoring levels.
The operation of the sonde described above will now be described during a complete measurement cycle.
The sonde is lowered into the borehole with the arms 31, 32 in the retracted position. In this position, the motor 35 is not supplied and is blocked by its brake 37. The coupling device is clutched, i.e. the toothed plates 85, 86 are engaged and the bushing 88 is up against the part 107. The resistant torque furnished by the motor opposes the extension of the arms under the action of the leaf spring 43. Each of the rollers 66 occupies an advanced position F in the section 68a of its cam slot, in contact with the lower wall L of said section.
When the sonde reaches the level H 1 corresponding to the first measurement planned, the motor 35 is started up in the counterclockwise direction. The arms 31, 32 can then move away under the action of the leaf springs 43. In this extension phase, the motor 35 acts only to limit the arm extension speed. The rollers 66 are kept in contact with the lower walls L by the action of the springs 43, so that the spring 52 cannot act to move the bushing 88 away from the stop 107.
When the pad 30 comes into contact with the borehole wall, the action of the springs 43 ceases. With the motor 35 continuing to rotate in the same direction, the rollers 66 come into contact with the upper walls H of the sections 68a of the cam slots. The spring 52 then drives the bushing 88 away from its contact with the stop 107 and also the sleeve 65. The friction ring 71 moved with the sleeve rubs against the conical surface 75.
When the bushing 88 comes up against the circlip 90, the action of the spring 52 ceases. The pursual of the rotation of the motor 35, since the rotation of the sleeve 65 is blocked by the friction of the ring 71, causes a movement of the wheels 66 in the cam slots toward the middle portion 68c (position D of wheels). The sleeve 65 thus moves in the direction of the reducer, this movement bringing about complete decoupling of the toothed plates 85, 86. The device is thus placed in the unclutched position. When the sleeve 65 reaches the end position shown in FIG. 4, the microswitch 82 is energized and the pulse produced stops the motor 35.
To anchor the pad in the wall, the motor 35 is started up again, still in the opposite direction. The wheels 66 then advance in the sections 68b of the cam slots. The toothed plate 85 comes into contact with the plate 86. During this first movement of the sleeve, the friction ring 71 is not moved.
With the rotation of the motor continuing, the rollers 66 continue to advance and the sleeve 65 drives the bushing 88 against the action of the spring 52. With this, the circlip 80 drives the friction ring 71 back so that the friction which prevented the sleeve 65 from turning disappears gradually. However, the motor torque is not really transmitted to the bushing 88 until the latter is in contact with the stop 107. Until then, the motor torque has served only to overcome the action of the spring 52. When this contact takes place, the rollers 66 have reached their end position A in the sections 68b.
As of this contact, the coupling device being in the clutched position, the motor torque is transmitted to the screw 40. The rod 34 connected to the nut 41 moves in the direction of the reducer to anchor the pad in the wall. This movement of the rod is very limited, of the order of a few millimeters.
The transducer 150 sends to the cartridge 22 a signal representative of the anchoring force on the pad. When the force reaches the above-mentioned predetermined value, corresponding to a satisfactory anchoring, the cartridge 22 stops the motor 35.
The phase which follows is the seismic acquisition phase proper at the considered level. Several successive firings are carried out by means of the source 11, and the seismic waves which are propagated on the formations are detected by the detection section. The detection signals produced following the respective firings are transmitted by the cartridge 24 and the cable 13 to the surface equipment 16 where they are recorded on a graphic medium and on magnetic tape.
Throughout this phase, the position of the elements of the anchoring section does not vary: motor blocked by its brake, coupling device clutched. The only difference compared with the retracted position is that the rollers 66 are in the slot sections 68b instead of being in the slot sections 68a.
As indicated above, the monitoring of the anchoring force makes it possible to remedy any reduction in this force during the seismic acquisition. To accomplish this, it is sufficient to start up the motor 35 again, still in the opposite direction. The motor will be stopped as soon as the anchoring force reaches the desired value.
After this measurement phase, the pad 30 must be dislodged from the wall. The motor 35 is started up in clockwise direction (direct direction), thereby ending the action of the brake 37. As long as a force on the pad due to the elasticity of the formation is exerted in the disanchoring direction on the screw 40, the rollers 66 remain in the position A. When this force is cancelled, the spring 52 drives back the bushing 88 out of contact with the stop 107. The corresponding movement of the sleeve 65 allows the friction ring 71 to come back into contact with the conical surface 75. The action of the spring 52 ceases when the bushing 88 comes up against the circlip 90. The rotation of the sleeve 65 is then blocked and, owing to the rotation of the motor, the sleeve undergoes a translation in the direction of the reducer, after which the toothed plate 85 ceases to be engaged with the toothed plate 86.
At the end of this movement, the rollers 66 have reached the position D in the central part of the cam slots, and the sleeve 65 actuates the switch 82 so that the motor 35 stops. The pad 30 is kept in contact with the borehole wall by the springs 43.
The next phase is the movement of the sonde from the level H 1 to a second measurement level H 2 , by winding the cable 13 on its winch. During this movement, the motor 35 remains stopped, the coupling device remains in the unclutched position, the rollers 66 remaining in position D, and the pad slides over the borehole wall, the contact being maintained with the wall by the springs 43.
During this movement, the electrode 181 thus remains in contact with the wall. It is supplied with current throughout the movement. The current which flows through the formation is, as seen, indicative of the resistivity of a zone of small thickness around the borehole.
When the sonde has reached the second measurement level H 2 , the anchoring, seismic acquisition and disanchoring operations are repeated and the sonde is brought up to a third measurement level H 3 , and so on.
It will be observed that since the pad remains constantly in contact with the wall, the only mechanical operations to be carried out at each level are the anchoring and disanchoring of the pad, and that there is no need to extend and retract the arms carrying the pad at each level. This represents a time saving, especially as the total number of measurement levels for a complete cycle can be more than a hundred.
Once the disanchoring of the pad is completed at the last measurement level, the arms 31, 32 must be retracted to bring the sonde back up to the surface. For this purpose, the motor 35 is started up in the direct direction. The rotation of the sleeve 65 is initially blocked by the friction ring 71, and the rollers 66 in the position D corresponding to unclutching.
Owing to the rotation of the motor, the wheels advance in the groove section 68a.
The sleeve 65 moves until contact is made between the toothed plates 85, 86 then, with the springs 43 exerting a resistant torque on the bushing 88, the sleeve 65 continues its travel while driving back the bushing 88 against the action of the spring 52. When the bushing 88 comes into contact with the stop 107, the motor torque is transmitted to the bushing 88 and overcomes the resistant torque offered by the springs 43 to cause the swivelling of the arms 32, 32 up to their retracted position along the sonde bodey member.
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The present invention relates to the acquisition of seismic signals at different levels in a borehole, in response to the generation of seismic waves by a source placed on the surface or in the vicinity of the surface. The acquisition is carried out by means of a sonde suspended in the borehole from a cable and equipped with an anchoring pad. At each acquisition level, the pad is anchored in the borehole wall to couple the sonde to the formation, and then the pad is released from the wall once the acquisition is over. The signals acquired are then sent to the surface by means of the cable. The force with which the pad is anchored in the wall is controlled by means of a feedback arrangement which includes a sensor arranged in the pad itself. During the sonde movements from one level to another, the pad is kept in contact with the wall.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part application of U.S. patent application Ser. No. 10/669,971 filed on Sep. 24, 2003. The disclosure of the above application is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to prosthetic implants. In particular, the present invention relates to a humeral resurfacing implant.
BACKGROUND OF THE INVENTION
The humerus is the longest and largest bone of the human upper extremity. It is divisible into a body and two extremities. The upper extremity comprises a head that is joined to the body by a constricted portion generally called the neck. The head is nearly hemispherical in form and articulates with the glenoid cavity of the scapula or shoulder blade. The humerus is secured to the scapula by the rotator cuff muscles and tendons.
It is not uncommon for the exterior surface of the humeral head to be damaged or defective. Conventionally, a variety of humeral head resurfacing implants exist for repairing humeral head surfaces. While conventional humeral head resurfacing implants are suitable for their intended uses, such implants are subject to improvement.
Conventional humeral head resurfacing implants fail to accommodate patients having inadequate rotator cuff muscles. Specifically, conventional implants do not permit articulation between the implant and the concave undersurface of the coracoacromial arch of the scapula, the coracoacromial arch being a structural component of the shoulder comprising the coracoacromial ligament, coracoid process, and acromion. Thus, there is a need for a humeral head resurfacing implant that permits articulation with the coracoacromial arch in patients having inadequate rotator cuff muscles.
SUMMARY OF THE INVENTION
In one embodiment, the present invention provides for a resurfacing implant comprising a head and an extended articulating surface protruding from a portion of the head operable to articulate with at least one of a bone and a ligament. The head has an exterior articulating surface, an interior surface opposite the exterior articulating surface, and an anchoring device extending from the interior surface.
In another embodiment, the present invention provides for a humeral head resurfacing implant comprising a humeral head having an articulating surface, an engagement stem extending from the head, and an extended surface protruding from the head operable to articulate with at least one element of a coracoacromial arch.
In yet another embodiment, the present invention provides for a method for resurfacing a humeral head of an implant site. The method comprises preparing the humeral head and implanting an implant at the humeral head. The implant has an exterior articulating surface, an interior surface opposite the exterior surface, a stem extending from the interior surface, and an extended articulating surface operable to articulate with at least one element of a coracoacromial arch.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a perspective view of an implant according to the present invention;
FIG. 2 is bottom view of the implant of FIG. 1 ;
FIG. 3A is a cross-sectional view taken along line 3 - 3 of FIG. 2 ;
FIG. 3B is a cross-sectional side view of the implant of the present invention according to an additional embodiment;
FIG. 4 is a perspective view of a typical implantation site prepared to receive the implant of FIG. 1 ;
FIG. 5 is a perspective view of the implant of FIG. 1 implanted at the implantation site of FIG. 4 ;
FIG. 6 represents a monolithic implant according to an embodiment of the invention;
FIGS. 7A-7D represent a modular prosthetic head;
FIGS. 8A-8D represent an alternate modular prosthetic;
FIGS. 9 and 10 represent an alternate modular prosthetic utilizing a snap-ring fixation mechanism;
FIG. 11 represents a tool for use to implant the prosthesis shown in FIGS. 7A-10 ; and
FIGS. 12-22 represent the preparation of a humerus to accept the implant shown in FIGS. 7A-10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
With initial reference to FIGS. 1 through 3 , a resurfacing implant according to the present invention is illustrated and identified at reference numeral 10 . The implant 10 is typically divided into, as illustrated in FIG. 3 , a lateral region A and a medial region B, which is in relation to the implant position in the patient. The implant 10 generally includes a resurfacing head 12 , an anchoring device or stem 14 , and an extended surface 16 . The extended surface 16 may be located in the lateral region A, as illustrated, or at any other position about a periphery of the head 12 . The head 12 includes an exterior surface 18 and an interior surface 20 opposite the exterior surface 18 . The exterior surface 18 is generally convex, or dome-shaped, and smooth. The interior surface 20 is generally concave.
The interior surface 20 is also generally dome-shaped and substantially mirrors the exterior surface 18 . The interior surface 20 is generally concave. The interior surface 20 may be smooth or may include features, such as pores or coatings that facilitate bonding of the interior surface 20 to a resurfaced implant site. The interior surface 20 may be bonded to the implant site with or without bone cement. The interior surface 20 optionally terminates at an annular rim 24 .
The stem 14 extends from the interior surface 20 . The stem 14 may optionally be tapered such that the diameter of the stem 14 is at its greatest at the interior surface 20 . To facilitate cooperation between the stem 14 and the implant site, the stem 14 may optionally include one or more details, such as flutes 26 . In addition to or in place of flutes 26 , the stem 14 may include surface features, such as pores or coatings, to enhance the creation of a bond between the stem 14 and the implant site.
In some applications, the extended surface 16 is located in the lateral region A to engage a surface or bone, such as at least one portion of the coracoacromial arch. However, the extended surface 16 may be located at any other position about the rim 24 to engage a variety of different bones and/or ligaments. The extended surface 16 is generally comprised of an outer surface 28 , a base surface 30 , and an inner surface 32 . The outer surface 28 is typically a continuation of the exterior surface 18 . The outer surface 28 may be of any suitable shape or configuration, however, in many instances, the outer surface 28 is curved or rounded to follow the general shape of the exterior surface 18 . The outer surface 28 extends about a portion, but less than an entirety of the annular rim 24 . The extended surface 16 generally extends beyond an equator of the hemispherical head 12 , which is generally defined by the rim 24 . As seen in FIG. 3A , the extended surface 16 extends from the head 12 in a planar and/or cylindrical manner.
The base surface 30 generally extends from the outer surface 28 toward the stem 14 at approximately a right angle to the outer surface 28 . The base surface 30 may be generally planar or may include various surface features to enhance interaction between the base surface 30 and the implantation site. The base surface 30 is typically shaped to accommodate the curvature of the annular rim 24 . The length of the base surface 30 determines, in part, the width of the extended surface 16 .
The inner surface 32 extends from the base surface 30 toward the interior surface 20 . The inner surface 32 extends from the base surface 30 at an approximate right angle to the base surface 30 . The inner surface 32 may be of any suitable shape but is typically shaped to generally accommodate the curvature of the annular rim 24 . In some applications, the inner surface 32 may be wedged shaped, typically in the shape of a “V”, to generally facilitate interaction between the implant 10 and the implantation site by providing a surface that matches the shape of a prepared bone that is to receive the implant 10 . The shape of the inner surface 32 , such as the wedge shape, may be used to act as a further aide to maintain the implant 10 in its desired position and prevent rotation of the implant 10 at the implantation site.
If the extended surface 16 is of a relatively small width, the inner surface 32 may be an extension of the interior surface 20 ( FIG. 3A ). As illustrated in FIG. 3B , if the extended surface 16 is of a relatively large width, the inner surface 32 is not a continuation of the interior surface 20 , but is connected to the interior surface 20 by an upper surface 34 . The upper surface 34 runs generally parallel to the base surface 30 and may be, for example, planar or curved. The upper surface 34 forms a step on the extended surface 16 .
The implant 10 may be made of any suitable biocompatible material, but is typically made from a metal such as cobalt chrome or titanium. The interior surface 20 may be coated with a suitable material, such as titanium plasma spray or hydroxyapatite, to enhance the adhesion of the interior surface 20 to the implantation site or to enhance the effectiveness of any material, such as bone cement, that may be used to affix the interior surface 20 to the implantation site. The stem 14 may optionally be provided with a blasted finish, with or without hydroxyapatite, or a micro-bond finish, with or without hydroxyapatite. As a further option, bone cement may be used as an aide to retain the implant 10 in position.
The implant 10 may be of various different sizes and dimensions depending on the sizes and dimensions of the implant site. For example, to accommodate patients having large humeral heads, the implant 10 may be of a greater overall size than that required to accommodate patients having smaller humeral heads. Further, the shape of the exterior surface 18 may be customized to insure proper articulation at the implant site. Implants 10 of various different shapes and sizes may be packaged together and sold in a single kit.
With reference to FIGS. 4 and 5 , the implantation and operation of the implant 10 will be described in detail. While the implant 10 is generally described as a humeral head resurfacing implant, it must be noted that the implant 10 may be used in a variety of different applications. The implantation site generally includes a humerus 36 and a shoulder blade or scapula 38 . The humerus 36 is generally comprised of a head 40 , a neck 42 , and a stem 44 . The scapula 38 is generally comprised of a glenoid cavity 46 that receives the head 40 , a coracoacromial arch 48 , and a coracoid process 50 .
To receive the implant 10 , a portion of the exterior surface of the humeral head 40 is resurfaced and/or removed to accommodate the resurfacing head 12 of the implant 10 such that, when implanted, the implant head 12 does not generally increase the overall dimensions of the humeral head 40 . The head 12 is further resected at 52 to accommodate the extended surface 16 . This resection at 52 may be performed with or without the use of a resection jig. To minimize bone loss, the resection at 52 often takes the shape of a “V”, however, the resection 52 may be of various other shapes or configurations. The “V” shape may also prevent rotation of the head 12 , even though the interaction between the stem 14 and the implant site is more than adequate to secure the head 12 into position.
To receive the stem 14 , which is generally referred to as a short stem 14 , a peg hole 54 is formed within the head 40 using conventional instruments and techniques. The hole 54 is formed with dimensions substantially similar to the dimensions of the stem 14 and is positioned such that when the stem 14 is seated within the hole 54 , the exterior surface 18 closely approximates the outer surface of the humeral head 40 . The hole 54 extends generally only through a portion of the humeral head 40 and does not necessarily extend to the stem 44 or within the intramedullary canal of the humerus. To ensure proper placement of the implant 10 , a trial implant (not shown) may be positioned at the implantation site before the implant 10 is implanted.
The trial implant is substantially similar to the implant 10 . A stem of the trial implant is placed within the hole 54 and the shoulder joint is reduced. If necessary, the head 40 is reamed to better approximate the size and shape of the interior surface 20 . After the proper position of the trial implant is noted, the trial is removed and the stem 14 of the implant 10 is seated within the hole 54 . The implant 10 is then positioned such that it is in substantially the same position as the trial implant. The particular size of the implant 10 is chosen according to the size and dimensions of the patient's humeral head 40 and scapula 38 . It must be noted that typically the stem 14 only extends through a portion of the head 40 and does not enter, or replace, the natural stem 44 of the humerus 36 .
As illustrated in FIG. 5 , the implant 10 is orientated at the humeral head 40 such that the extended surface 16 is positioned at or near the coracoacromial arch 48 . The extended surface 16 may either abut, or closely abut, the coracoacromial arch 48 . When the patient's rotator cuff muscles are inadequate, the extended surface 16 typically contacts the coracoacromial arch to provide metal on bone articulation with the coracoacromial arch 48 . However, the extended surface 16 may be rotated to any other position to engage other bones, ligaments, or surfaces other than, or in addition to, the coracoacromial arch 48 .
While interaction between the stem 14 and the hole 54 is typically suitable to secure the implant 10 within the hole 54 , the stem 14 may optionally be secured within the hole 54 using a suitable adhesive, such as bone cement 56 . The optional bone cement 56 may be inserted within the hole 54 , typically before the implant 10 is placed within the hole 54 . The flutes 26 of the stem 14 assist in forming a cement mantle between the stem 14 and the hole 54 to receive the bone cement 56 . The optional tapered configuration and blasted finish of stem 14 further enhances the bond between the implant 10 and the head 40 by providing a mechanical interface. To still further secure the implant 10 to the head 40 , a suitable adhesive, such as bone cement, may be placed between the interior surface 20 and the head 40 and various coatings may be applied to the interior surface 20 , such as titanium plasma, to create a bond between the interior surface 20 and the head 40 .
With the implant 10 in place upon the humeral head 40 , patients with inadequate rotator cuff muscles are provided with a device that permits articulation between the humerus 36 and the coracoacromial arch 48 . This articulation between the humerus 36 and the coracoacromial arch 48 enhances range of motion in the patient's shoulder and reduces patient discomfort.
FIG. 6 represents a monolithic resurfacing implant according to the teachings of an alternate embodiment. The implant 60 includes a resurfacing head 62 , an anchoring device or stem 64 and an extended bearing member 66 . The head 62 has a generally spherical articulating bearing surface 68 and an interior coupling surface 70 .
The stem 64 is coupled to the interior surface 70 and can have various surface features 72 to facilitate the coupling of the implant to a resected humerus. Disposed between the articulating surface 68 and the internal surface 70 of the implant 60 is a base surface 71 . The base surface 71 is congruent with the base surface 73 of the bearing member 66 . The internal surface 70 defines a generally spherical surface 74 , which seats against a resected spherical bearing surface 76 of the humerus. Additionally, the interior surface 70 defines three flat intersecting surfaces 78 A-C. Optionally, the surfaces 78 A and B intersect with surface 78 C at obtuse angles. The surfaces 78 A-C are supported by the corresponding resected surfaces in the humeral head.
As shown in FIGS. 6 , 7 A- 7 D and 8 A- 8 D, the extended surface can vary in radial width W and length L. As shown in FIG. 7A-8D , the extended surface can be an additional modular component 80 , which can be coupled to the head using varying fixation mechanisms 81 . In this regard, the fixation mechanism can optionally take the form of a pair of interference fit members, such as a Morse taper. Additionally, as shown in FIGS. 8B-8D , the fixation member can be a fastener such as a screw.
As shown in FIGS. 7A-7D , the modular component 80 has an exterior articulating surface 84 which can have varying radii of curvature which are congruent with the articulating surface 68 . The modular component 80 can have a male or female Morse taper which corresponds with a complimentary structure on the interior coupling surface 70 . Additionally shown is an anti-rotation member 86 in the form of a pin. As shown in FIGS. 8A-8D , the additional modular components 80 can be coupled to the implant 60 via the threaded bore 89 . The threaded bore 89 can optionally be parallel or perpendicular to the fixation stem 64 .
FIGS. 9 and 10 represent cross-sectional and exploded views of an alternative prosthetic. The additional modular component 80 is coupled to the interior coupling surface 70 via a ring lock 87 . The ring 87 is configured to couple the annular modular component 80 ′ using the groove 88 defined on the bearing surface 68 , and a groove 90 defined on an interior surface 92 of the modular component 80 ′.
FIG. 11 represents a cutting guide 98 which allows for the preparation of the humerus. In this regard, the cutting guide 98 allows for the removal of tuberosities to make room for an extended implant. The cutting guide 98 has a main body 100 and a cannulated handle 102 . The underside 104 of the main body has a spherical concave surface 108 that relates to the spherical radius of a spherical cutter 109 used to prepare the humerus. The guide 98 is configured to be fully seated on the resurfaced humeral head 76 . A plurality of slots 106 are formed within the main body 100 for viewing the resurfaced head to determine if the guide is well seated. Additional holes 107 are formed in the guide main body 100 , which accept a plurality of guide pins 110 . These pins 110 prevent the rotation of the cutting guide 100 during the resection of the humerus.
Further defined in the cutting guide main body 100 are a plurality of angled cutting slots 112 , which are configured to match the flats 78 A- 78 C created on the inner surface on the resurfacing implant. In this regard, the angled slots 112 can form compound angles with respect to each other. Additional groups can be formed on an exterior peripheral surface of the main body to facilitate the removal of material. To insure the cutting guide is properly oriented, markings 114 can be formed on the outside surface of the cutting guide. These markings are intended to allow the relative rotation and placement of the cutting guide with respect to predetermined or known anatomical locations, such as the bicipital groove.
The handle 102 defines a through passage 116 or aperture, which is configured to slidably accept a Steinmann pin 118 . It is envisioned that the handle can be removable from the body portion to facilitate the resection through the number of slots in the main body.
FIGS. 12-22 represent the preparation of the humerus to accept any of the aforementioned prosthetics. FIG. 12 represents the first step in inserting the extended articulating surface humeral resurfacing head. First, a drill guide 120 is used to locate the center of the humeral head. The drill guide 120 has a generally spherical concave inner surface 122 , which is configured to conform to the generally spherical surface of the humeral head. The drilling guide has a cannulated handle 124 , which is used to direct the placement of the Steinmann pin 118 .
As shown in FIG. 12 , the Steinmann pin 118 is disposed through the guide to mark the location of the center of the head. As also shown in FIG. 13 , a spherical surface cutter 126 is placed over the Steinmann pin and used to ream the surface of the head to remove a predetermined amount of biological tissue (see FIG. 14 ). Optionally, the reaming continues until bone is shown coming through a plurality of holes 128 within the cutter.
The cutting guide 100 , as shown in FIG. 16 , is placed over the Steinmann pin 118 . The cutting guide 100 is rotated so that the marking 114 on the exterior surface of the cutting guide is lined up with the bicipital groove. The additional guide pins 110 are then placed through the guide holes 107 in the guide to prevent relative rotation of the cutting guide 100 with respect to the humerus during the resection of the humeral head.
At this point, a rotational or reciprocal cutting tool 130 is placed within the cutting grooves 112 formed in the cutting guide 100 . This tool is used to form a plurality of flat surfaces 132 on the humerus. At this point, the anti-rotation pins and cutting guide are removed from the resected humerus. A spade bit 134 is placed over the Steinmann pin 118 and rotated until a stop ledge 136 touches the humeral head. Both the spade bit 134 and Steinmann pin 118 are removed from the humerus. A trial head (see FIG. 19 ) is then placed onto the resurfacing bone and used to check the full range of motion and correct soft tissue tensioning. Lastly, the final prosthetic is placed onto the bone and impacted into place.
FIGS. 20-22 represent the placement of the prosthetic 60 onto the prepared humerus. As can be seen, the exterior portion 66 is positioned to allow proper articulation of the repaired joint. A trialing head 60 ′ is positioned to the prepared humerus. The head 60 is then coupled to the resected humerus as previously described.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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A resurfacing implant comprising a head and an extended articulating surface protruding from a portion of the head operable to articulate with at least one of a bone and a ligament. The head has an exterior articulating surface, an interior surface opposite the exterior articulating surface, and an anchoring device extending from the interior surface.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to a synthetic resin molded article having a good and durable antistatic property and a process for the preparation thereof.
(2) Description of the Related Art
At the present, many synthetic resin molded articles having many good properties are marketed, but since they generally have a high electric resistance and are easily charged with electricity by friction or the like, they attract dust and dirt, and thus the appearance thereof becomes poor.
As the means for imparting an antistatic property to synthetic resin molded articles, there can be mentioned (1) internal addition of a surface active agent, (2) surface coating with a surface active agent, (3) surface coating with a silicon compound and (4) surface modification by a plasma treatment. Of these methods, methods (3) and (4) are not practical because of the high cost thereof, and methods (1) and (2) are generally adopted.
In the method of the internal addition of a surface active agent, since a surface active agent is incorporated or dispersed in a synthetic resin-forming starting material before the polymerization or a synthetic resin before the molding, the preparation steps can be simplified, but to obtain a required antistatic property, it is generally necessary to increase the amount of a surface active agent. This increase of the amount of the surface active agent added, however, tends to result in a lowering of the mechanical strength of the synthetic resin, and the obtained antistatic property is easily lost when washed with water or by rubbing.
The method of coating the surface with a surface active agent is advantageous in that the physical properties of the synthetic resin as the substrate are not lowered and a good antistatic property can be obtained with a small amount of the surface active agent. On the other hand, since the surface-coating step is necessary, an additional cost is required, and there is a danger that the beautiful appearance inherently possessed by a synthetic resin molded article will be lost. Moreover, the method has a problem in that the obtained antistatic property is easily lost by water washing or rubbing.
The inventors previously disclosed a cationic antistatic polymer having a quaternary ammonium base therein in Japanese Unexamined Patent Publication No. 63-108040, but this cationic polymer has a poor heat stability, and thus the polymer is adversely affected by heat.
SUMMARY OF THE INVENTION
In view of the foregoing, a primary object of the present invention to provide a synthetic resin molded article having a good and durable antistatic property and retaining the inherent physical properties of the synthetic resin.
The inventors carried out research with a view to achieve the above object, and as a result found that, by forming a film of a specific anionic polymer on the molding surface of a casting mold and polymerizing a synthetic resin-forming starting material for a synthetic resin substrate by using this casting mold, a synthetic resin molded article having a good and durable antistatic property is obtained.
More specifically, in accordance with the present invention, there is provided a synthetic resin molded article having a good antistatic property, which comprises a synthetic resin substrate and a film of an antistatic polymer formed on the surface of the synthetic resin substrate, said antistatic polymer being formed by polymerizing an anionic monomer represented by the following general formula (I) or a mixture comprising at least 20% by weight of said anionic monomer and up to 80% by weight of at least one monomer copolymerizable therewith: ##STR2## wherein R 1 represents a hydrogen atom or a methyl group, A 1 represents ##STR3## X represents a nitrogen atom or a phosphorus atom, R 2 , R 3 , R 4 and R 5 independently represent an alkyl, aryl or aralkyl group having 1 to 18 carbon atoms which may have a substituent, n is 0, 1 or 2, B represents an alkylene, arylene or aralkylene group having 1 to 18 carbon atoms which may have an ester bond, and R6 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
This molded article can be prepared by forming a film of the antistatic polymer on the molding surface of a casting mold by polymerizing the above-mentioned monomer or monomer mixture, casting a synthetic resin-forming starting material for the synthetic resin substrate into the casting mold, polymerizing and curing the starting material to transfer the film to onto the synthetic resin substrate from the mold surface and withdrawing the obtained molded article from the casting mold.
The anionic antistatic polymer has a good heat stability, and little deterioration of the polymer occurs at the polymerizing and curing step and heat processing step where the temperature is elevated, and from this viewpoint, the anionic antistatic polymer is advantageous over cationic antistatic polymers.
BRIEF DESCRIPTION OF THE DRAWING
The drawing illustrates an embodiment of the apparatus for the continuous preparation of the synthetic resin molded article of the invention in the form of a methacrylic resin plate, which apparatus is provided with a film-forming starting material-coating device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The anionic monomer used in the present invention is represented by the following general formula (I): ##STR4##
As specific examples of the anionic monomer of general formula (I), there can be mentioned tetramethylammonium vinylsulfonate, benzyltrimethylammonium vinylsulfonate, tetraethylammonium allylsulfonate, benzyltriethylammonium methallylsulfonate, methyltriethylolammonium sulfoethylmethacrylate, lauryltrimethylammonium sulfoethylacrylate, tetramethylammonium 2-acrylamido-2-methylpropanesulfonate, methyltriethylammonium 2-methacrylamido-2-methylpropanesulfonate, methyltriethylolammonium styrenesulfonate/ethylene oxide adduct, tetrabutylammonium α-methylstyrenesulfonate, tetraethylphosphonium vinylsulfonate, tetrabutylphosphonium vinylsulfonate, tetramethylolphosphonium vinylsulfonate, tetrabutylphosphonium allylsulfonate, tetralaurylphosphonium methallylsulfonate, tributylmethylphosphonium sulfoethylmethacrylate, triethylbutylphosphonium sulfoethylacrylate, tetrabutylphosphonium sulfopropylacrylamide, trimethylolbutylphosphonium sulfopropylmethacrylamide, tetrabutylphosphonium styrenesulfonate, tetramethylolphosphonium styrenesulfonate and triethylmethylphosphonium α-methylstyrenesulfonate.
Among these anionic monomers, an appropriate monomer is freely selected according to the kind of the synthetic resin substrate used. For example, when a methyl methacrylate resin is used as the synthetic resin substrate, in view of the compatibility with the methyl methacrylate resin and the easy availability of the starting material, ammonium salts of 2-acrylamido-2-methylpropanesulfonic acid, sulfoethylmethacrylic acid and sulfoethylacrylic acid are preferably used, and tetramethylammonium salts thereof are especially preferably used.
A monomer of general formula (I), in which at least one of R 2 through R 5 is a hydrogen atom, is not preferable because the resistance against thermal deterioration is lowered and discoloration occurs at the polymerizing and curing step and heat processing step at which the temperature is elevated, and the compatibility with the substrate synthetic resin and the adhesion to the synthetic resin substrate are reduced.
A known monomer can be used as the monomer copolymerizable with the anionic monomer of general formula (I). For example, there can be mentioned methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, acrylic acid esters such as methyl acrylate and ethyl acrylate, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, acid anhydrides such as maleic anhydride and itaconic anhydride, maleimide derivatives such as N-phenylmaleimide, hydroxyl group-containing monomers 2-hydroxyethyl acrylate and 2-hydroxypropyl methacrylate, nitrogen-containing monomers such as acrylamide and acrylonitrile, epoxy group-containing monomers such as allyl glycidyl ether and glycidyl acrylate, bifunctional monomers such as allyl methacrylate and allyl acrylate, and polymeric monomers such as methacrylate-terminated polymethyl methacrylate, styryl-terminated polymethyl methacrylate, methacrylate-terminated polystyrene, methacrylate-terminated polyethylene glycol and methacrylate-terminated acrylonitrile/styrene copolymer.
As the copolymerizable monomer, there are preferably used compounds represented by the following general formula (II): ##STR5## wherein R 7 represents a hydrogen atom or a methyl group, R 8 represents a hydrogen atom or an alkyl, aralkyl or aryl group having 1 to 18 carbon atoms, which has no copolymerizable functional group, A 2 represents an alkylene group having 2 to 4 carbon atoms, and m is an integer of from 0 to 500, and copolymerizable compounds having at least two unsaturated double bonds. Especially preferably, at least two compounds selected from the foregoing two types are used in combination.
As the compound of general formula (II) in which m is 0, there can be mentioned methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, benzyl methacrylate, phenyl methacrylate, cyclohexyl methacrylate and 2-hydroxyethyl methacrylate.
As the compound of general formula (II) in which m is from 2 to 500, there can be mentioned polyethylene glycol(4) monomethacrylate, polyethylene glycol(23) monoacrylate, polyethylene glycol(23) monomethacrylate, polyethylene glycol(300) monomethacrylate, polypropylene glycol(23) monomethacrylate, polybutylene glycol(23) monomethacrylate, polyethylene glycol(23) monomethacrylate monomethyl ether, polyethylene glycol(23) monomethacrylate monobutyl ether, polyethylene glycol(23) monomethacrylate monostearyl ether, polyethylene glycol(23) monomethacrylate monophenyl ether, polyethylene glycol(23) monomethacrylate monobenzyl ether and polyethylene glycol(23) monomethacrylate mono-oleyl ether. Note, each parenthesized value indicates the number of alkylene glycol units in the polyalkylene glycol.
In view of the adhesion between the antistatic property-imparting copolymer and the synthetic resin substrate, the copolymerizable monomer is preferably the same as the monomer constituting the substrate synthetic resin, or a monomer forming a synthetic resin having a good compatibility with the synthetic resin substrate.
For example, when the synthetic resin substrate is a polymer comprising methyl methacrylate as the main component, if a monomer of general formula (II) in which m is 0 is used, a good adhesion is obtained between the synthetic resin substrate and the antistatic property-imparting copolymer. Therefore, in this case, the film of the antistatic property-imparting copolymer is not left in the casting mold at the time of peeling, and a stable antistatic property can be manifested regardless of kind of the casting mold used. If a monomer of general formula (II) in which m is from 2 to 500 is used, the release property of the synthetic resin molded article from the casting mold, especially the release property at a high temperature, is improved, and an antistatic synthetic resin molded article can be stably obtained.
As the copolymerizable monomer having at least two unsaturated double bonds, there can be mentioned allyl acrylate, methallyl acrylate, vinyl acrylate, allyl methacrylate, methallyl methacrylate, vinyl methacrylate, 1-chlorovinyl methacrylate, isopropenyl methacrylate, N-methacryloxymaleimide, ethylene glycol dimethacrylate, butanediol dimethacrylate, polyethylene glycol dimethacrylate, allyl vinyl ether, allyl vinyl ketone, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate and triallyl cyanurate.
When the copolymerizable compound having at least two unsaturated double bonds is used, the copolymer film of the present invention has a crosslinked portion and a residual double bond, which contribute to an improvement of the strength of the film per se, formation of a semi-IPN structure of the synthetic resin substrate and formation of a chemical bonding to the substrate by graft polymerization of the monomer to the residual double bonding, and a result, the surface hardness of the molded article and the adhesion of the copolymer film to the synthetic resin substrate, i.e., the durable antistatic property, can be improved.
Especially, when one of the functional groups is a functional group having a polymerizability lower than that of the methacryloyl group or acryloyl group, such as an allyl group, a methallyl group, a vinylidene group or a vinylene group, an unreacted double bond is left in the polymeric antistatic agent and performs a graft polymerization during the polymerization for the synthetic resin substrates, and therefore, a good adhesion is obtained between the film of the antistatic property-imparting polymer and the synthetic resin substrate.
As the monomer copolymerizable with the anionic monomer represented by general formula (I), when the synthetic resin substrate is a methyl methacrylate polymer, there is preferably used a combination of (a) a compound of general formula (II) in which m is from 2 to 0, (b) a compound of general formula (II) in which m is 0, especially methyl methacrylate, and (c) a copolymerizable compound having at least two unsaturated double bonds, especially allyl methacrylate or allyl acrylate.
The antistatic polymer of the present invention comprises 20 to 100% by weight, preferably 20 to 80% by eight, of units derived from an anionic monomer represented by general formula (I), and 0 to 80% by weight, preferably 20 to 80% by weight, of units derived from a copolymerizable monomer. If the amount of the anionic monomer of general formula (I) is smaller than 20% by weight, a good antistatic property cannot be given to an obtained synthetic resin molded article, for example, a methacrylic resin cast plate. From the viewpoint of the adhesion of the antistatic polymer to the synthetic resin substrate, the copolymerizable monomer other than the monomer of general formula (I) is preferably used in an amount of at least 20% by weight.
When the synthetic resin substrate is a methyl methacrylate resin, an antistatic polymer comprising 20 to 70% by weight of units derived from an anionic monomer of the general formula (I), and as the copolymerizable monomer, (a) 24.9 to 74.9% by weight of units derived from a monomer of general formula (II) in which m is from 2 to 500, (b) 5 to 55% by weight of units derived from a monomer of the general formula (II) in which m is 0 and (c) 0.1 to 10% by weight of units derived from a copolymerizable compound having at least two unsaturated double bonds, is especially preferably used.
Preferably, the molecular weight of the antistatic polymer used in the present invention is at least 1,000. If the molecular weight of the antistatic polymer is lower than 1,000, a film having a good and durable antistatic performance is difficult to obtain.
A durable antistatic property is attained according to the present invention because the film of the antistatic polymer is integrated with the synthetic resin substrate. More specifically, the film formed on the surface of the casting molding is swollen with a synthetic resin-forming starting material at the polymerization for the synthetic resin substrate, and in this state, the polymerization is advanced and the film is integrated with the as-polymerized surface portion of the molded article obtained according to the present invention, the antistatic property thereof is not lowered, when washed with water or by rubbing and the molded article of the present invention is advantageous in this point over a product obtained according to the coating method using a surface active agent. Moreover, according to the present invention, since the film of the antistatic polymer is present only on the surface of the molded article, a good antistatic performance can be obtained even with a small amount of the antistatic polymer.
The starting material used for the synthetic resin substrate is not particularly critical. For example, there can be mentioned methyl methacrylate, styrene and other polymerizable monomer, partial polymerization products thereof, a polyol and a polyisocyanate, an oligomer having epoxy groups at both the terminals and a polyamine or polyamide, an unsaturated polyester, a novolak polymer and a bisoxadorine, a reactive silicone rubber oligomer, and a polycarbonate cyclic oligomer.
A methacrylic resin prepared from methyl methacrylate, a monomer mixture comprising at least 50% by weight of methyl methacrylate and up to 50% by weight of at least one monomer copolymerizable therewith, or a partial polymerization product thereof is most preferably used as the synthetic resin substrate.
As the monomer copolymerizable with methyl methacrylate, there can be mentioned methacrylic acid esters such as ethyl methacrylate, butyl methacrylate and 2-ethylhexyl methacrylate, acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid, acid anhydrides such as maleic anhydride and itaconic anhydride, maleimide derivatives such as N-phenylmaleimide, N-cyclohexylmaleimide and N-t-butyl-maleimide, hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate, nitrogen-containing monomers such as acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, diacetone acrylamide and dimethylaminoethyl methacrylate, epoxy group-containing monomers such as allyl glycidyl ether, glycidyl acrylate and glycidyl methacrylate, styrene monomers such as styrene and α-methylstyrene, and crosslinking agents such as ethylene glycol diacrylate, allyl acrylate, ethylene glycol dimethacrylate, allyl methacrylate, divinylbenzene and trimethylolpropane triacrylate, although the copolymerizable monomers that can be used are not limited to those exemplified above. The kind and amount of the copolymerizable monomer added are determined according to the intended synthetic resin molded article.
Additives such as colorants, release agents, ultraviolet absorbers, heat stabilizers and various fillers can be incorporated in the starting material for the synthetic resin substrate used in the present invention.
As examples of the casting mold used in the present invention, there can be mentioned those made of inorganic glasses such as tempered glass, metals such as stainless steel, aluminum and a chromium plated metal, and resins such as a polyester resin. The surface of the casting mold is generally a mirror-polished surface, but a surface which has been subjected to a delustering treatment by forming fine undulations on the surface can be used according to the intended object.
A method in which a solution of the copolymer in water and/or an organic solvent is coated on the casting mold surface is a simple and advantageous method for the formation of a film of the copolymer on the surface of the casting mold. When the synthetic resin substrate is a methacrylic resin, in view of the adhesion to the synthetic resin substrate and the spreading of the solvent, there is especially preferably used a method in which methyl methacrylate or a mixture comprising 50% by weight of methyl methacrylate and up to 50% by weight of a monoethylenically unsaturated monomer copolymerizable therewith, or a partial polymerization product thereof, is coated on the surface of the casting mold.
Additive components such as release agents, defoaming agents, levelling agents, monomers and crosslinking agents can be incorporated into the above-mentioned solution or mixture, as long as the antistatic performance of the film obtained from the solution or mixture, the polymerizability of the synthetic resin substrate-forming starting material and the physical properties of the synthetic resin substrate, are not lowered.
As the means for coating the above-mentioned solution or mixture, there can be mentioned a spray coating method, a flow coating method, a bar coating method, and a dip coating method.
When a plate-shaped methacrylic resin molded article is prepared according to the present invention, from the viewpoint of the productivity, there is preferably adopted a continuous casting process using as a casting mold two confronting stainless steel endless belts each having one mirror-polished surface, which are moved in the same direction at the same speed.
The present invention will now be described in detail with reference to the following examples, that by no means limit the scope of the invention. In the examples, parts are by weight.
All of the electric properties of the samples were determined after they had been moisture-conditioned at a temperature of 20° C. and a relative humidity of 65% for 1 day. The charge half-value time was measured under conditions of an applied voltage of 10,000 V, a sample-rotating speed of 1,550 rpm, a voltage application time of 30 seconds, a measurement temperature of 20° C., and a measurement relative humidity of 65%. The voltage of the sample at the application of the voltage was designated as the initial voltage (V), and the time required for the voltage of the sample to fall from the initial voltage to 1/2 thereof was designated as the charge half-value time (sec). The surface resistivity (Ω) after 1 minute from the point of application of a voltage of 500 V was measured at a measurement temperature of 20° C. and a measurement relative humidity of 65%, as the surface resistivity by a high megohm meter (Model TR-8601 supplied by Takeda Riken).
The surface resistivity after water washing was measured by the above-mentioned high megohm meter after the obtained plate had been cut into a test piece having a size of 40 mm ×40 mm, and the test piece had been strongly wiped 60 times with a gauze in running water.
The surface hardness was determined according to the pencil scratch test of JIS K-5400 (usual test methods for paints).
The transparency was evaluated based on the haze value by using an integrating sphere haze meter (Model SEP-H-SS supplied by Nippon Seimitsu Kogaku).
EXAMPLE 1
A glass flask equipped with stirring vanes was charged with 312.4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 450 parts of methanol, and 550.3 parts of a 25% by weight solution of tetramethylammonium hydroxide in methanol was added dropwise with violent stirring so that the temperature was held below 30° C. after the dropping, the mixture was stirred for 30 minutes to obtain an anionic monomer (M-1), then, 4 parts of azobisisobutyronitrile, 3 parts of n-octylmercaptan, 38 parts of methanol, and 423 parts of polyethylene glycol(23) monomethacrylate monomethyl ether were added to the obtained anionic monomer (M-1) solution, and polymerization was carried out at 60° C. for 4 hours in a nitrogen atmosphere. The reaction product was then vacuum-dried to obtain an antistatic polymer (P-1).
Then, 5 parts of the polymer (P-1) were dissolved in 95 parts of ethanol to prepare a film-forming starting material. On a mirror-polished surface of a stainless steel plate having a length of 600 mm, a width of 450 mm and a thickness of 3 mm, the film-forming starting material was spray-coated and dried. By using a pair of the thus-treated stainless steel plate and gaskets, a casting mold was constructed so that the thickness of the cast product was 3 mm. A synthetic resin-forming starting material prepared by dissolving 0.05 part of 2,2'-azobisisobutyronitrile in 100 parts of partially polymerized methyl methacrylate having a viscosity of 1,000 cP as determined at 20° C. and a polymerization conversion of 20%, and removing dissolved air under a reduced pressure, was cast into the casting mold, and polymerization was carried out at 60° C. for 10 hours and further at 110° C. for 4 hours. Then, the temperature was lowered to the normal temperature, and the molded product was parted from the casting mold.
The surface resistivity of the obtained methacrylic resin plate was 9.2×10 10 Ω, the charge half-value time was 1 second, and the haze value was 1.0%. The surface hardness was B as determined according to the pencil scratch test of JIS K-5400.
The obtained plate was washed with water and the antistatic property immediately evaluated, and it was found that the surface resistivity of the obtained methacrylic resin plate was 3.5×10 10 Ω and the charge half-value time was 1 second.
EXAMPLE 2
A glass flask equipped with stirring vanes was charged with 312.4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 450 parts of methanol, and 1042.8 parts of a 40% by weight solution of tetrabutyl phosphonium hydroxide in methanol was added dropwise with violent stirring so that the temperature was held below 30° C. After the dropping, the mixture was stirred for 30 minutes to obtain a solution of an anionic monomer (M-2), and to the obtained anionic monomer (M-2) solution were added 4 parts of azobisisobutyronitrile, 3 parts of n-octylmercaptan, 200 parts of methanol, and 702 parts of polyethylene glycol(23) monomethacrylate monomethyl ether, and polymerization was carried out at 60° C. for 4 hours in a nitrogen atmosphere. The polymerization product was directly vacuum-dried to obtain an antistatic polymer (P-2), and a methacrylic resin plate was prepared in the same manner as described in Example 1 by using the obtained polymer (P-2).
The surface resistivity of the obtained methacrylic resin plate was 4.3×10 10 Ω, the charge half-value time was 1 second, and the haze value was 1.0%. The surface hardness was B as determined according to the pencil scratch test of JIS K-5400.
The obtained plate was washed with water and the antistatic property immediately evaluated, and it was found that the surface resistivity was 9.5×10 10 Ω and the charge half-value time was 1 second.
EXAMPLE 3
A glass flask equipped with stirring vanes was charged with 156.7 parts of 2-acrylamido-2-methylpropanesulfonic acid and 220 parts of methanol, and 276.1 parts of a 25% by weight solution of tetramethylammonium hydroxide in methanol was added dropwise with violent stirring so that the temperature was held below 30° C. After the dropping, the mixture was stirred for 30 minutes to obtain a solution of an anionic monomer (M-1), and to the obtained anionic monomer (M-1) solution were added 3 parts of azobisisobutyronitrile, 2 parts of n-octylmercaptan, 80 parts of methanol, 283 parts of polyethylene glycol(23) monomethacrylate monomethyl ether, 212 parts of methyl methacrylate and 18 parts of allyl methacrylate, and polymerization was carried out at 60° C. for 5 hours in a nitrogen atmosphere to obtain a solution of an antistatic polymer (P-3). Then a methacrylic resin plate was prepared in the same manner as described in Example 1 by using the obtained polymer (P-3).
The surface resistivity of the obtained methacrylic resin plate was 5.8×10 10 Ω, the charge half-value time was shorter than 1 second, and the haze value was 1.0%. The surface hardness was 3H as determined according to the pencil scratch test of JIS K-5400.
The obtained plate was washed with water and the antistatic property immediately evaluated, and it was found that the surface resistivity was 4.3×10 10 Ω and the charge half-value time was shorter than 1 second.
EXAMPLE 4
A glass flask equipped with stirring vanes was charged with 156.7 parts of 2-acrylamido-2-methylpropanesulfonic acid and 220 parts of methanol, and 523.1 parts of a 40% by weight solution of tetrabutylphosphonium hydroxide in methanol was added dropwise with stirring so that the temperature was held below 30 minutes, to obtain a solution of an anionic monomer (M-2), and to the obtained anionic monomer (M-2) solution were added 3 parts of azobisisobutyronitrile, 2 parts of n-octylmercaptan, 80 parts of methanol, 470 parts of polyethylene glycol(23) monomethacrylate monomethyl ether, 352 parts of methyl methacrylate and 35 parts of allyl methacrylate, and polymerization was carried out at 60° C. for 5 hours in a nitrogen atmosphere to obtain a solution of an antistatic polymer (P-4). A methacrylic resin plate was prepared in the same manner as described in Example 1 by using the obtained polymer (P-4).
The surface resistivity of the obtained methacrylic resin plate was 6.3×10 10 Ω, the charge half-value time was 1 second, and the haze value was 1.0%. The surface hardness was 3H as determined according to the pencil scratch test of JIS K-5400.
The obtained plate was washed with water and the antistatic property immediately evaluated, and it was found that the surface resistivity was 6.5×10 10 Ω and the charge half-value time was 1 second.
COMPARATIVE EXAMPLE 1
A methacrylic resin plate having a thickness of 3 mm was prepared in the same manner as described in Example 1, except that a mirror-polished stainless steel plate not treated with the antistatic polymer was used.
The surface resistivity of the plate was higher than 10 16 Ω, the charge half-value time was longer than 120 seconds, the haze value was 1.0%, and the surface hardness was 3H.
EXAMPLE 5
A methacrylic resin plate having a thickness of 3 mm was prepared in the same manner as described in Example 1 except that tempered glass sheets having a length of 600 mm, a width of 450 mm, and a thickness of 6 mm was used as the casting mold. The surface resistivity of the obtained resin plate was 7.8×10 9 Ω, the charge half-value was 1 second, the haze value was 1.0%, and the surface hardness was HB.
After the water washing, the surface resistivity was 2.3×10 10 Ω and the charge half-value time was 1 second.
EXAMPLE 6
30 A laminate formed by bonding a polyester film (Lumilar supplied by Toray; standard type having a thickness of 250 μm) to the surface of a stainless steel plate having a length of 600 mm, a width of 450 mm, and a thickness of 3 mm was used as the casting mold, and a methacrylic resin plate having a thickness of 3 mm was prepared in the same manner as described in Example 1. The surface resistivity of the obtained resin plate was 7.2×10 9 Ω, the charge half-value time was 1 second, and the surface hardness was B.
After the water washing, the surface resistivity was 5.6×10 10 Ω and the charge half-value time was 1 second.
EXAMPLE 7
A methacrylic resin plate having a thickness of 3 mm was prepared in the same manner as described in Example 1, except that a mixture of 2.0 parts of polymer (P-1), 51.0 parts of methyl methacrylate and 47.0 parts of partially polymerized methyl methacrylate having a viscosity of 100 cP and a polymerization conversion of 8% was coated as the film-forming starting material on the casting mold by a bar coater. The surface resistivity of the obtained resin plate had a surface resistivity of 2.3×10 10 Ω, a charge half-value shorter than 1 second and a haze value of 1.0%. The surface hardness was H as determined according to the pencil scratch test of JIS K-5400.
After the water washing, the surface resistivity was 2.5×10 10 Ω and the charge half-value time was shorter than 1 second.
EXAMPLE 8
A methacrylic resin plate was prepared in the same manner as described in Example 2 except that 5 parts of ethylene glycol dimethacrylate was used instead of allyl methacrylate. The surface resistivity of the obtained resin plate was 5.3×10 10 Ω, the charge half-value time was shorter than 1 second, and the haze value was 1.0%.
After the water washing, the surface resistivity was 6.4×10 10 Ω and the charge half-value time was shorter than shorter than 1 second. The surface hardness was 3H as determined according to the pencil scratch test of JIS K-5400.
EXAMPLES 9 THROUGH 15
Polymers (P-5) through (P-11) shown in Table 2 were prepared in the same manner as described in Example 1, by using the monomer (M-1) solution. Methacrylic resin plates having a thickness of 3 mm were prepared in the same manner as described in Example 1, by using these polymers. The evaluation results are shown in Table 2.
In Examples 9, 10 and 15, monomeric methyl methacrylate was used instead of the partially polymerized methyl methacrylate as the substrate resin-forming starting material.
In Examples 9 and 15, the parting from the casting mold was very difficult.
EXAMPLES 16 THROUGH 21
Monomers were prepared in the same manner as described in Example 1 or 2 except that a sulfonic acid-containing monomer shown in Table 1 and a quaternary ammonium base or quaternary phosphonium base shown in Table 1 were used.
TABLE 1______________________________________Mono- Sulfonic Acid-Containingmer Monomer Quaternary Base______________________________________M-3 Allylsulfonic acid Tetramethylammonium hydroxideM-4 Sulfoethyl methacrylate Lauryltrimethylammonium hydroxideM-5 Styrenesulfonic acid Benzyltrimethylammonium hydroxideM-6 Allylsulfonic acid Tetraethylphosphonium hydroxideM-7 Sulfoethyl methacrylate Benzyltriethylphospho- nium hydroxideM-8 Styrenesulfonic acid Tetrabutylphosphonium hydroxide______________________________________
Polymers (P-12) through (P-17) shown in Table 2 were prepared in the same manner as described in Example 1 or 2, by using solutions of monomers (M-3) through (M-8) shown in Table 1.
Methacrylic resin plates having a thickness of 3 mm were prepared in the same manner as described in Example 1 by using these copolymers. The evaluation results are shown in Table 2.
EXAMPLE 22
An apparatus for the continuous production of a methacrylic resin plate as shown in the accompanying drawing was used as the casting mold.
Referring to the accompanying drawings, belts 1 and 1'are endless stainless steel belts having a mirror-polished surface, a width of 1.5 m and a thickness of 1 mm. The belts were moved at a speed of 2 m/min by driving a main pulley 2, The initial tension on the belts was given by hydraulic cylinders arranged on pulleys 2 and 2' and set at 10 kg/mm 2 of the sectional area of the belts. Also reference numerals 3 and 3' represent pulleys.
Film-forming starting materials 5 and 5' comprising 2.0% by weight of copolymer (P-3), 96.0% by weight of methyl methacrylate and 2.0% by weight of methanol were coated on the mirror-polished surfaces of belts 1 and 1' by roll coaters 6 and 6'.
The film-formed belts were arranged to confront each other, and both side portions thereof were sealed by hollow pipe gaskets 15 of polyvinyl chloride charged with a considerable amount of a plastizier. A synthetic resin substrate-forming starting material 14 comprising 100 parts of partially polymerized methyl methacrylate (the content of a polymer having an average degree of polymerization of 1,800 was 21%), 0.05 part of 2,2'-azobis(2,4-dimethylvaleronitrile) and 0.01 part of Tinuvin P was supplied between the belts through a casting device by a metering pump.
The total length of the polymerization zone was 96 m. In the former part having a length of 66 m, the distance between the confronting surfaces of the belts as controlled by a plurality of idle rollers 4 and 4' arranged at intervals of 15 cm and warm water maintained at 80° C. was spray-scattered on the outer surfaces of the belts. In the latter part having a length of 30 m, the belts were supported by idle rollers arranged at intervals of 1 m, and the cast material was heated at about 130° C. by an infrared heater and then cooled. after the cooling, the product was peeled from the belts, and thus a methacrylic resin plate having a thickness of 3 mm was continuously prepared.
The surface resistivity of the obtained resin plate was 2.0×10 10 Ω, the charge half-value time was shorter than 1 second, and the haze value was 1.0%. The surface hardness was 3H as determined according to the pencil scratch test method of JIS K-5400.
After the water washing, the surface resistivity was 1.3×10 10 Ω, and the charge half-value time was shorter than 1 second.
COMPARATIVE EXAMPLES 2 AND 3
Polymers (P-18) and (P-19) shown in Table 2 were prepared in the same manner as described in Example 1, by using the solution of monomer (M-1). Methacrylic resin plates having a thickness of 3 mm were prepared in the same manner as described in Example 1 by using these polymers. The evaluation results are shown in Table 2.
COMPARATIVE EXAMPLE 4
A methacrylic resin plate having a thickness of 3 mm was prepared in the same manner as described in Example 1, except that a 10% by weight solution of a coating type antistatic agent having a quaternary ammonium base (Statiside supplied by Analytical Chemical Laboratories) in methanol was used as the film-forming starting material.
The surface resistivity of the obtained resin plate was 1.6×10 9 Ω and the half-value time was shorter than 1 second, but many fine undulation defects were formed on the surface of the resin plate by a partial peeling from the surface of the casting mold during the polymerization.
COMPARATIVE EXAMPLE 5
A glass flask equipped with stirring vanes was charged with 312.4 parts of 2-acrylamido-2-methylpropanesulfonic acid and 450 parts of methanol, and a mixture of 102.8 parts of 25% by weight aqueous ammonia and 240 parts of methanol was added dropwise with violent stirring so that the temperature was held below 30° C. The mixture was stirred for 30 minutes to obtain an anionic monomer (M-9) solution, and to the obtained anionic monomer (M-9) solution were added 3.2 parts of azobisisobutyronitrile, 2.4 parts of n-octyl-mercaptan, 30 parts of methanol and 360 parts of polyethylene glycol(23) monomethacrylate monomethyl ether, and polymerization was carried out at 60° C. for 4 hours in a nitrogen atmosphere. After the polymerization, the polymerization product was directly dried in vacuo to obtain an antistatic polymer (P-18).
A methacrylic resin plate was prepared in the same manner as described in Example 1 by using the obtained polymer (P-18). Parting of the plate from the stainless steel plate as the casting mold was not good, and a peeling phenomenon in which the antistatic polymer was left on the stainless steel plate was observed, and the surface of the methacrylic resin plate was slightly yellowed.
From the results of Comparative Example 5, it is seen that if counter cations R 2 through R 5 in general formula (I) are hydrogen atoms, the compatibility with the resin and the resistance against thermal deterioration are lowered.
TABLE 2__________________________________________________________________________ Surface resistivity Monomers Surface after Hazer Amount Amount Amount resistivity washing value Polymer Kind (parts) Kind (parts) Kind (parts) (Ω) (Ω) (%)__________________________________________________________________________Example 9 P-5 M-1 100 -- -- -- -- 1.5 × 10.sup.10 3.6 × 10.sup.12 1.2Example 10 P-6 M-1 80 PEG(23) 20 -- -- 1.3 × 10.sup.10 2.2 1.0mes. 10.sup.1Example 11 P-7 M-1 20 PEG(23) 40 Methyl 40 5.3 × 10.sup.11 5.1 1.0mes. 10.sup.1 methacrylateExample 12 P-8 M-1 50 PEG(9) 50 -- -- 2.3 × 10.sup.11 8.5 1.0mes. 10.sup.1Example 13 P-9 M-1 50 PEG(500) 50 -- -- 5.3 × 10.sup.10 9.8 1.0mes. 10.sup.1Example 14 P-10 M-1 30 PEG(23) 40 Methyl 30 3.8 × 4.5 1.0mes. 10.sup.1 acrylateExample 15 P-11 M-1 50 Methyl 50 -- -- 1.2 × 10.sup.11 9.8 1.0mes. 10.sup.1 methacrylateExample 16 P-12 M-3 50 PEG(23) 50 -- -- 2.5 × 10.sup.11 7.3 1.0mes. 10.sup.1Example 17 P-13 M-4 50 PEG(23) 50 -- -- 3.8 × 10.sup.11 9.1 1.0mes. 10.sup.1Example 18 P-14 M-5 50 PEG(23) 50 -- -- 7.3 × 10.sup.10 3.6 1.0mes. 10.sup.1Example 19 P-15 M-6 50 PEG(23) 50 -- -- 1.5 × 10.sup.10 8.5 1.0mes. 10.sup.1Example 20 P-16 M-7 50 PEG(23) 50 -- -- 8.7 × 10.sup.10 2.2 1.0mes. 10.sup.1Example 21 P-17 M-8 50 PEG(23) 50 -- -- 2.1 × 10.sup.10 5.3 1.0mes. 10.sup.1Comparative P-18 M-1 10 PEG(23) 90 -- -- 5.3 × 10.sup.14 9.3 1.0mes. 10.sup.1Example 2Comparative P-19 M-1 10 PEG(23) 10 Methyl 80 8.9 × 10.sup.14 1.3 1.0mes. 10.sup.1Example 3 methacrylate__________________________________________________________________________ Note PEG(23): polyethylene glycol(23) monomethacrylate monomethyl ether PEG(9): polyethylene glycol(9) monomethacrylate monomethyl ether PEG(500): polyethylene glycol(500) monomethacrylate monomethyl ether Note, each parenthesized value indicates the number of alkylene glycol units in the polyalkylene glycol.
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A synthetic resin molded article having a good antistatic property, which including a synthetic resin substrate and a film of an antistatic polymer formed on the surface of the substrate. The antistatic polymer is prepared by polymerizing an anionic monomer represented by the formula (I) or a mixture of the anionic monomer and a monomer copolymerizable therewith: ##STR1## R 2 , R 3 , R 4 and R 5 independently represent an alkyl, aryl or aralkyl group which may have a substituent, n is 0, 1 or 2, B is an alkylene, arylene or aralkylene group which may have an ester bond, and R 6 is H or an alkyl group.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an equipment for mechanical ventilation which is used to ventilate a patient, comprising at least a ventilator and an endotracheal tube or a ventilatory mask. In addition the invention relates to a method to ventilate a patient, in which operating parameters are measured during mechanical ventilation which are used to control ventilation.
[0003] 2. Description of the Prior Art
[0004] Artificial or mechanical ventilation takes place either in the controlled mode or in a mode of (supported) spontaneous breathing. In the first case the ventilator has complete control over the respiratory pattern, whereas in the second case the—at least—partially spontaneously breathing patient has a considerable influence on the respiratory pattern. However, a feature which is common to all modes of mechanical ventilation is that the ventilator exclusively exerts influence on the inspiratory phase. The ventilator takes over the mechanical work of breathing exclusively during the inspiratory phase. The expiration—from the perspective of the ventilator—occurs passively, that is the energy stored in the elastic tissue elements of lung and thorax generates the drive for expiration. Consequently, the passive deflation of the lung follows an exponential decay curve with a time-constant which is determined by the volume distensibility (compliance) of the respiratory system as well as by the sum of the airway resistances of the biological and artificial airways (Guttmann J, Eberhard L, Fabry B, Bertschmann W, Zeravik J, Adolph M, Eckart J, Wolff G. Time ConstantNolume Relationship of Passive Expiration in Mechanically Ventilated ARDS Patients. Eur Respir J 8(1):114-20, 1995).
[0005] On the part of the ventilator only the end-expiratory pressure level (PEEP) and the expiratory time which is available is actively influenced up to now.
[0006] A technical realization is already known in which the patient is relieved from the flow-dependent airflow resistance of the endotracheal tube. This mode of support is called ATC (Automatic Tube Compensation) (Fabry B, Guttmann J, Eberhard L, Wolff G. Automatic compensation of endotracheal tube resistance in spontaneously breathing patients. Technol Health Care 1: 281-291, 1994). (ATC: registered trademark (Dräger Medical, Lübeck, Germany)
[0007] In German Patent 101 31 653 C2 a method and a device for supply of respiratory gas to a person is proposed. In the context of sleep related breathing disorders preferentially in the frame of homecare ventilation, the airway pressure at the breathing mask can selectively be set either lower or higher than the level of ambient pressure. By decreasing the airway pressure below ambient pressure, the need of mechanical stabilization of the upper airways by overpressure can be determined. Furthermore a screening of snoring syndromes as well as of the susceptibility of obstruction in asthma is possible. In the frame of respiratory therapy, this method can also be applied to reduce the airway pressure below ambient pressure during the expiratory cycles.
[0008] From German Patent 195 16 536 C2 a method and a ventilator are known in which the advantages of pressure-controlled ventilation by controlling the airway pressure, and the volume-controlled ventilation by controlling the respiratory volume and the free (Durchatembarkeit) should be combined. By stepwise adaptation of the inspiratory pressure level, a pressure-controlled ventilation with an adjustable tidal volume can be applied. There are setpoints allowed for the inspiratory and expiratory airway pressure, which produce switching from one respiratory phase to the other in the case they are exceeded due to active inspiratory or expiratory efforts.
[0009] From WO 02/082997 A2 a control device to preset an airway pressure level is known. Using this device should allow determination of those characteristics of airway pressure which are advantageous with respect to the momentary physiological status of the patient. The setting of airway pressure is realized in dependence of automatically detected respiratory events like apneas or hypopneas. Accordingly, the therapeutic airway pressures are adapted.
SUMMARY OF THE INVENTION
[0010] The present invention provides a ventilatory equipment that allows advanced diagnostics including the analysis of respiratory mechanics of the respiratory system (lung and thorax) and an advanced therapy with respect to practically all indications of artificial ventilation are possible.
[0011] The ventilatory equipment of the invention controls the expiratory phase with controllable actuators for providing active manipulation of the expiration and for generation of a user-defined pattern of expiration during the expiratory phase.
[0012] In particular the expiratory patterns can be generated by forced time-dependent courses of airflow and/or of airway pressure and/or of respiratory gas volume.
[0013] Preferentially a controller unit is provided to force an expiratory pattern for an expiratory phase, whereby a measuring device which is connected with the control unit records the course of expiration during an expiratory phase at the natural exhalation of the patient as well as means for limitation or acceleration of the patient' expiration are provided which are connected to the control unit.
[0014] According to the present invention, one expiratory pattern is predefined for one expiratory phase at a time and the natural exhalation of the patient is adapted at the predefined expiratory pattern either by limitation or by acceleration of the exhalation during the expiratory phase.
[0015] For registration of the expiratory pattern during natural exhalation of the patient, the airway pressure and/or the airflow rate and/or the gas volume are measured during the expiratory phase and are compared with the corresponding data of the predefined expiratory pattern and the actual expiration is affected.
[0016] According to the present invention the respiratory pattern (airflow, airway pressure and breathing volume) during the expiratory phase follows a certain time course. Consequently an active control of the respiratory pattern is introduced particularly by a change of the courses of airway pressure and airflow rate during the expiratory phase.
[0017] The method can be applied during controlled ventilation as well as during spontaneous breathing both for diagnostics and therapeutic purposes.
[0018] For example in patients with obstructive ventilatory disorders, the airways can be mechanically stabilized by setting a higher airway pressure during a high expiratory flow compared to the pressure at a lower expiratory flow (imitation of the expiratory flow limitation due to purse one's lips). In patients with acute pulmonary distress, the formation of atelectases and the concomitant occurrence of ventilator induced lung injury (VILI) can be reduced by a specific limitation of the expiratory flow. The latter is realized by a reduction of the effective shear forces.
[0019] An active manipulation of the respiratory pattern during the expiratory phase is notedly reasonable and desirable with regard to diagnostics as well as to therapy.
[0020] In a preferential embodiment, the control unit with its sensors and with the actuators of the ventilation equipment comprises a functional unit. The functional unit can be implemented in an existing ventilator or can be connected with a ventilator as an external device.
[0021] To implement this functional unit into a medical device the technology of modern ventilators can be utilized because in principle an active manipulation of the expiratory pattern is already possible. The expiratory valve can perform the function of reducing the expiratory flow. If required, a supplementary subathmospheric pressure source could be implemented into the ventilator.
[0022] If realized as a separate unit, the elements (actuators) influencing the pneumatic system can be attached directly to the expiratory connector of the ventilator.
[0023] Furthermore, an upgrade of hardware and/or software of existing ventilators can be realized in an advantageous way.
[0024] Finally the realization as an external device allows an extension of functionality in already existing older ventilators.
[0025] A preferential design of the invention provides sensor inputs in the control unit to allow for a closed-loop control based on pressure and/or flow- and/or volume sensors, that is using measured respiratory data. Optionally already one measurement category may be sufficient to adjust the desired expiratory pattern. However, it is particularly advantageous with respect to patient safety to typically consider the airway pressure in the control loop. The combination of several sensory inputs results in an advantageous improvement of the precision of control.
[0026] According to an alternative design, the control unit may contain inputs for anthropometrical or physiological data. Inputs for anthropometric data allow in an advantageous manner an automatically adapted ventilatory setting for example according to height and weight of the patient. Inputs for physiologic data typically but not exclusively include informations about the illness or about the actual status of the patient's illness. By using inputs for such types of data, the control system can be advantageously adapted to the individual disease pattern.
[0027] Advantageously—especially when the control unit is realized as an external device—this unit influencing the respiratory airflow course is realized according to the principle of a controller with fixed setpoints. The desired expiratory pattern can be simply realized by a fixed mechanical coupling of typically a volume pump (without controller).
[0028] In all other cases it is advantageous if a closed-loop control is used with sensor inputs—typically but not exclusively—respiratory measuring data like pressure, flow and volume. By using respiratory measuring data, the safety of the method can be improved in an advantageous manner. For example—but not exclusively, by considering the airway pressure, short-term pressure peaks due to coughing or pressing can be avoided. By incorporation of non-respiratory measured data, the influence of the expiratory pattern, for example on the cardiovascular system, can be considered in an advantageous manner.
[0029] If applicable, the manipulation of the respiratory airflow course can be realized according to the principle of a controller with fixed setpoints. This type of manipulation can be selected in an advantageous manner particularly in the case where the control-loop of the ventilation equipment cannot react fast enough to realize the desired manipulation.
[0030] A complementary design of the invention provides that either the airway pressure or the flow rate or the volume during the expiratory phase are controlled typically as a function of time and/or of pressure and/or of flow and/or of volume. This type of control can be particularly selected in an advantageous manner, when the changes of expiration should be realized in dependence of the respiratory mechanics of the diseased lung.
[0031] Optionally the manipulation of the expiration is realized in dependence or in independence of the respiratory pattern during inspiration and of the ventilatory type. In this way, it can be achieved in an advantageous manner, that—depending on the wish of the user—either the expiratory pattern is exclusively set (independent manipulation) or a simplified combination mode (dependent manipulation) can be selected.
[0032] According to another embodiment of the invention the manipulation of the expiration can be applied during controlled mechanical ventilation, during supported or during non-supported spontaneous breathing.
[0033] Thereby the manipulation (influence) of the expiration can be achieved in an advantageous manner for every possible application of respiratory therapy and the active manipulation of the expiration can be combined respectively with every ventilatory type and mode in an advantageous manner.
[0034] The manipulation of the expiration can be applied in an advantageous manner during endotracheal intubation or during ventilation via a breathing mask. Consequently, the manipulation of the expiration can be applied independently from the access to the airways. In addition the influence of the access to the airways on the expiratory pattern can be considered.
[0035] Advantageously the shape/course of the expiratory function can be arbitrarily, it can be for example a simple ramp or a half-sine-wave. Good approximations towards complex control functions with a physiological rationale can be achieved in an advantageous manner with technically simply realizable functions—typically when using a controller with fixed setpoints—.
[0036] Optionally the expiratory function is combined with positive end-expiratory pressure (PEEP) or replaces the latter. The active manipulation of the expiratory pattern can be combined with the set PEEP, without changing it. In an advantageous manner the expiratory function can be designed such that it replaces the PEEP or it takes over the role of PEEP.
[0037] According to an embodiment of the invention, the change of pressure, of flow or of volume, which is effected by the control unit compared to a passive expiration, can have a positive or a negative sign or also changing signs.
[0038] The limitation of the expiratory flow causes an increase of the mean pulmonary volume during the expiration, which has a mechanically stabilizing effect on the diseased lung. Particularly at a short expiratory time an airflow acceleration which follows an airflow limitation can keep constant the expiratory volume in an advantageous manner and can avoid an overinflation (intrinsic PEEP) of the lungs.
[0039] If appropriate the duration of the controlling phase can be variable. The period of active control of the expiration may be independent from the duration of the expiratory phase (typically shorter). Thereby the period of control is determined exclusively by the clinical demands.
[0040] In addition there exists the alternative that the duration of the controlling phase exceeds the duration of a single expiration. Advantageously the manipulation of the expiratory pattern can be realized over a variable number of breaths according to a presetting “A”, than can be inactivated or can be continued according to a new presetting “B” in terms of polymorphous ventilation.
[0041] The shape/course of the expiratory function can act in accordance with the special application and with the goals which are to be achieved by using the controlling technique. The high variability of the controlling technique guarantees that the expiratory pattern can be approximated on the individual patient as well as on the relative demands of the treating physician for example with respect to the analysis of the respiratory mechanics during expiration.
[0042] It is advantageous if the shape/course of the expiratory function is particularly adapted during the controlling period. By this means—dependent from the clinial demands—the presettings for controlling the expiratory pattern can be changed within a breath (intratidal) or breath-by-breath.
[0043] Advantageously, the settings of the controller can be realized manually or automatically, particularly in an adaptive way. The advantageous plasticity in the application of the method enables that the physician can pursuit typically short-term goals, or the physician can declare goals with the system, which the system tries to reach within a selectable period of time.
[0044] As the case may be, several functions can be superimposed or can alternate. Thereby an adaptation to fast or slow properties of respiratory mechanics (time constants) of the respiratory system is possible.
[0045] The period of time of the expiration can either be given by the ventilator or by the patient or by a combination of both. Advantageously the system recommends presettings for the expiratory time.
[0046] If required the expiratory time can be prolonged or shortened. Consequently, the system considers in an advantageous manner accomplished changes of the expiratory time.
[0047] Advantageously, parameters of respiratory mechanics are measured such as for example resistance, compliance or expiratory flow limitation. Advantageously the variables pressure, flow and volume can be interconnected in terms of a complex controlling.
[0048] Further advantageous designs of the invention are described in the other subclaims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] In the following the invention is explained in detail by means of figures.
[0050] It shows:
[0051] FIG. 1 is a schematic illustration of a functional unit according to the present invention including a control unit as well as actuators;
[0052] FIG. 2 a to 2 d are different pressure-volume-diagrams;
[0053] FIG. 3 shows flow, pressure and volume curves during inspiration and expiration;
[0054] FIG. 4 is a schematic illustration of alveoli in the collapsed status;
[0055] FIG. 5 is a schematic illustration of alveoli in the native status;
[0056] FIG. 6 is a diagram showing the dynamic pressure-volume-loop of a breath; and
[0057] FIG. 7 is a diagram showing the expiratory flow-time-curve of a breath.
DETAILED DESCRIPTION OF THE INVENTION
[0058] FIG. 1 schematically shows ventilation equipment WITH a functional unit 8 with three main components, namely a preferentially electronic control unit 1 and as actuators a controllable electromechanical unit 3 for changing the airflow resistance and a controllable unit 2 for changing the expiratory pressure.
[0059] The control unit 1 includes signal inputs 4 for pressure signals 4 a, flow signals 4 b and volume signals 4 c as well as a signal input for the setpoint input 5 for the desired expiratory breathing pattern. The control unit 1 provides control signals to both actuators 2 and 3 as well as via the output 6 to the expiration controller of the ventilator.
[0060] The control unit 1 can be set up in combination with the sensors which are connected with the inputs and with the actuators a functional unit. With respect to the connection of the complete functional unit with the ventilator, there are in principle two types of realization possible. On the one hand an implementation into a ventilator is possible. The technology of modern ventilators enables in principle an active manipulation of the expiratory pattern. Here the expiratory valve can take over the role of limiting the expiratory flow and in addition a source of subathmospheric pressure 2 can be implemented into the ventilator if required. On the other hand a separate functional unit can be utilized, whereby then the actuators are directly connected with the expiratory connector 7 of the ventilator.
[0061] As already mentioned, an active manipulation of the respiratory pattern during the expiration phase is most reasonable and desirable with respect to diagnostics as well as to therapy. For this some examples are given in the following:
[0062] Diagnostics: It is known that the mechanical properties of the respiratory system differ between inspiration and expiration. One of the reasons is a phenomenon called intratidal alveolar recruitment. In other words: there is alveolar tissue recruited during inspiration that collapses in the following expiration. It is expected that the difference between inspiratory and expiratory respiratory mechanics allows a quantification of the amount of intratidal recruitment/derecruitment. Hence, there is a considerable interest on the part of the intensive care doctors to analyze respiratory mechanics of lungs of the critically ill separately in inspiration and expiration (respiratory monitoring). This differentiation has failed up to now due to the nonlinear flow pattern of the expiratory phase. The lung is - in the mechanical sense - a passive elastic body with a more or less linear relationship between pressure and volume as this is shown in FIG. 2 a. The slope of the pressure-volume curve equals the Elastance E (=1/Compliance). As volume continuously changes during expiration—volume decreases from the tidal volume (VT)—the driving pressure for expiration decreases at the same time. The consequence is an exponential shape of the expiratory flow-time curve. ( FIG. 7 ). The concurrent change of gas flow and volume makes the differential equation that describes the mechanical properties of the respiratory system (equation of motion) insolvable. A distinct solution would be possible, however, if the flow would be (as an example) constant during the whole expiration. The latter is the case when the driving pressure would be steady (or not volume dependent) during the whole expiration (compare FIG. 2 b ). For this case, two areas are to be distinguished (compare FIG. 2 c ):
[0000] (A) the intrapulmonary pressure is above the set pressure; and
(B) the intrapulmonary pressure is below the set pressure.
For the area (A) this means that the “elastic” pressure of the lung would generate a higher expiratory flow than the flow that is given by the set pressure difference. In this case expiratory flow has to be “slowed down”. This could be reached exemplarily by increasing the flow resistance by actuator 3 ( FIG. 1 ). For the area (B) the intrapulmonary pressure obviously is not sufficient to generate an expiratory flow as is expected by the set pressure difference. In this case a flow increase is necessary; this can be realized, for example, by adding a regulated negative pressure source 2 ( FIG. 1 ). Generally spoken, the expiratory flow has to be reduced any time a situation (A) is desired, and the expiratory flow has to be increased any time a situation (B) is desired. To emphasize this, FIG. 2 d shows another example with which the Exspiration should be realized by three phases of steady flow.
[0063] A specific application for the diagnostic use is the analysis of nonlinear, dynamic respiratory mechanics. In the critically ill, I the mechanical properties of the lung (elasticity and resistance) are not constant, but they change even within the taking of a breath. The variability of respiratory mechanics manifests in many patients in a considerable intra-breath non-linearity.
[0064] FIG. 6 schematically shows the dynamic pressure-volume-loop of a breath during controlled mechanical ventilation. The change in slope of the dynamic PV-loop expresses the nonlinearity of the compliance, the different width of the PV-loop expresses the nonlinearity of flow resistance. New diagnostic procedures permit the analysis of nonlinear respiratory mechanics within the breath. To do so, the PV-loop is divided into several volume segments of equal size (SLICES) ( FIG. 6 ) and respiratory mechanics are analyzed for each segment separately using a mathematic procedure (Guttmann J, Eberhard L, Fabry B, Zapping D, Bernhard H, Lichtwarck-Aschoff M, Adolph M, Wolff G. Determination of Volume-Dependent Repiratory System Mechanics in Mechanically Ventilated Patients Using the Ne SLICE Method. Technol Health Care 2: 175-191, 1994).
[0065] It was not possible to date to perform the analysis of respiratory mechanics separately for inspiration and expiration. To stabilize the algorithm, in- and expiratory data had to be included into the analysis. According to the present invention, however, the gas flow during expiration could be set segment-wise constant.
[0066] FIG. 7 shows an expiratory flow-time curve of a breath. The dotted line shows the natural, exponential shape of the flow curve. To the exponential flow curve, a stair-shaped flow curve is adapted, the length of single steps being different. The solid line in FIG. 7 shows such a realization of an adapted stepwise liberalized expiratory flow. The different durations of the phases with constant flow correlate with the SLICE volume (compare FIG. 6 ). Therefore algorithmic stability is given and a separate analysis in inspiration and expiration is possible. In principle, according to the invention, any expiratory flow pattern and pressure pattern may be realized. This includes increasing and decreasing ramps with variable slope, proportionality to time, volume and flow as well as any nonlinear functions as sine or sawtooth or others.
[0067] Therapeutic use: In Patients with an obstructive disease, collapse of small airways during expiration is a common phenomenon. This mechanism not only causes increased work of breathing and under-ventilation of the lung. The impediment of expiration leads to an increase of intrathoracic pressure (dynamic hyperinflation) with serious consequences for the hemodynamic stability up to severe shock. An active change of expiratory flow in terms of a slowing down could correct the pathomechanism by splinting the airway.
[0068] In patients with acute or chronic respiratory failure, mechanical ventilation promotes additional damage to the already injured lung (ventilator associated lung injury-VALI). Above all, the shear forces that are induced by repeated closure of alveoli during expiration and their reopening during early inspiration have been linked to VALI (atelectrauma). Up to now, only by setting a constant end-expiratory pressure (PEEP) was used to influence the global strain within the lung. An active change of the expiratory flow pattern (in terms of slowing down the expiratory flow) might selectively stabilize instable alveoli. By active circumvention of high expiratory flows the global shear forces within the lungs could be reduced and VALI could be prevented.
[0069] On the other hand, the disturbed gas exchange in these patients obliges the caregiver to increase the breathing frequency thereby reducing the expiratory time. As a result expiration may become incomplete and increased intrapulmonary pressure may occur (intrinsic PEEP). A controlled increase of expiratory flow could remove PEEPi in this situation.
[0070] The artificial airways (endotracheal tube, tracheal cannula) prevent the natural cough and expectoration in ventilated patients. On one hand the tube is the major barrier for bronchial secretions and it prevents the glottic closure and tracheal collapse during coughing. In addition, the patients cough is reduced by sedatives and opioids. A specific manipulation (for example, biphasic) of the expiratory flow the transport of secretions and expectoration might be notably improved.
[0071] Patients that need mechanical ventilation have a high demand of sedatives. It has been proven that survival is negatively correlated with the amount of administered sedatives. Sedatives are needed, because mechanical ventilation is felt to be extremely unpleasant by the patient. It is known that the ventilation mode during inspiration influences patient comfort. During spontaneous breathing, the decrease of inspiratory muscle activity controls expiratory flow. In contrast, no such mechanism is available during mechanical ventilation. Imitation of a natural breathing pattern (by a specific presetting of the ventilator) would significantly increase patient comfort.
[0072] The severely ill lung is characterized by mechanical nonlinearity and by mechanical inhomogeneity. Active expiratory control will lead to a more homogeneous ventilation as possible to date with passive expiration. The latter includes the variation of expiratory control on y breath-by-breath base (polymorphous ventilation).
[0073] FIG. 3 shows a scheme for the therapeutic use of active expiratory control. In the example shown, the dotted lines show the natural course of passive expiration. The course is accomplished as from the beginning of passive expiration the pressure difference between alveoli and atmospheric pressure is decreasing. Therefore alveolar pressure which causes the peak flow at the beginning of the expiratory phase decreases quickly after onset of expiration. The risk of collapse of alveoli ( 9 ) is increased in the early phase of expiration due to the high transmural pressures. The injured lung is at high risk due to the formation of atelectasis. Cyclic collapse and reopening of alveoli ( 9 ) induces irreversible damage of the lung tissue. FIG. 5 shows alveoli ( 9 ) in their native situation.
[0074] Due to active expiratory control ( FIG. 3 solid line) gas is retained within the lung during the first half of expiration as compared to passive expiration (dotted line). Therefore the lung is mechanically stabilized and the injurious alveolar collapse is reduced. Early in expiration flow is markedly reduced (A). As, compared to passive expiration, less air is being exhaled in this phase, the intrapulmonary gas volume in higher (B). Because the flow rate is increased at the end of expiration (C), the same volume is exhaled during the complete expiration. Alveolar collapse is prevented, because in the second half of expiration the transalveolar pressure gradient is reduced as compared to the first half of the expiration phase. In both cases, the end-expiratory volume is the same (D). As the schematic illustration shows, it is possible to implement a biphasic modification of expiration without reducing the pressure below the set positive end-expiratory pressure (PEEP).
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The invention relates to a respiratory device for ventilating a patient. The respiratory device comprises a respirator that is or can be linked with an endotracheal tube or a respiratory mask. The respiratory device is provided with a control/regulation unit ( 1 ) for controlling and checking the expiration phase and with actuators ( 2, 39 ) controlled by the unit for actively influencing expiration and producing any expiration pattern during the expiration phase.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to geodesic domes, and more specifically to a prefabricated plastic tile and a strut designed for use together to create a strong, yet easy-to-assemble, geodesic dome.
[0003] 2. Background of the Invention
[0004] Structures in the form of geodesic domes have been being built since their invention by Buckminster Fuller in the 1950's, however their construction, until now, has involved a complicated and difficult procedure. A geodesic dome comprises a configuration of repeating geometric shapes, such as triangles, which form the dome's surface. The architecture of the dome structure is typically a series of struts which link to hubs to create the dome's framework. The area, or space, created between any three contiguous struts, i.e. the area of the triangles formed by these repeated struts and hubs, must necessarily be sub-divided, enclosed, and covered, as they are of a sizable dimension which is interdependent with the diameter of the dome itself.
[0005] In some prior art domes, a plurality of geometric tiles are secured together to form a three-dimensional geometric shape, which is assembled with other such secured-together three-dimensional geometric shapes in order to form the dome. This method of assembly is arduous and inefficient.
[0006] One prior art method of constructing geodesic domes involves manipulating polygonal panels of the dome so that they slide into lateral pockets formed on each side of a generally I-beam shaped strut. Such manipulation may not be difficult when inserting a first side of the panel, but once a first side is locked into place, it appears impractical, if not impossible, to angle and manipulate subsequent sides of the panel into place within the pockets of other struts.
[0007] Some prior art panels for geodesic domes are manufactured in layers, with inner and outer faces secured to intermediate support structure. Such a manufacturing method is more complicated and costly than desired.
[0008] In some prior art domes, in order to finish the interior of the dome after assembling the outer structure, panels of sheetrock or some other finishing material must be individually and precisely cut to fit the unique shape of each geometric section of the dome, and then taped and painted. This is a very time consuming and difficult process.
[0009] Prior art geodesic domes are manufactured by a process that involves many steps, and includes a complex structure to attach adjacent tiles to the struts that support them. The tiles of the prior art are not designed for, nor capable of, supporting significant amounts of weight, as would be necessary if the dome is to be earth-sheltered.
[0010] It is known that earth-sheltering a structure provides advantages in the energy needs for heating and cooling that structure. In order to be earth-sheltered, a structure must be capable of supporting the significant weight of the dirt located above the structure. Prior art panels and systems for building geodesic domes are not designed to bear such heavy loads.
[0011] There is a need in the art for a strong, lightweight preformed, easy-to-manufacture tile designed to support a significant amount of weight. There is a need for the tile and the struts which support it to be capable of being assembled to form a geodesic dome quickly and easily, with a minimal amount of skill and tools required. In addition, the tile should either be provided with an interior surface that is manufactured as a finished surface, or have a system that enables a finished surface to be quickly and easily attached thereto.
SUMMARY OF THE INVENTION
[0012] The present invention sets forth a tile for use in building a geodesic dome. The tile is a preformed plastic panel having a polygonal, typically triangular, footprint. The superior surface of the panel has a non-planar, three-dimensional surface, formed with planar surfaces extending up at an angle from respective side edges of the panel until they meet at a high point at the geometric center of the panel. The inferior surface of the panel includes a recessed portion extending along at least a portion of each side edge of the panel.
[0013] The panel may also include any combination of a variety of additional features, including beveled side edges, internally located molded reinforcing ribs for increased strength, an embedded reinforcing member of steel or some other suitable material, a flange extending outwardly from the upper surface of the panel at each of its side edges, and cut-away portions where each of two adjacent sides of the panel meet to accommodate a hub that joins supporting struts of the geodesic dome. Further, the underside of the panel may either comprise a finished interior surface, molded integrally with the rest of the tile, or the underside could comprise a separate sheet of finishing material sized and shaped to cover the exposed molded reinforcing ribs and including connecting structure on the separate sheet of finishing material and on the underside of the rest of the panel, whereby the separate sheet can snap into place on the underside of the panel to quickly and easily provide a finished interior surface of the dome.
[0014] The present invention further sets forth a strut for use with the inventive tile. A first configuration of the strut has a cross-section in the shape of an I-beam, with an L-shaped bracket seated upon a portion of the length of the lower lateral member of the “I”, such that one leg of the bracket rests along the vertical central member of the “I”, and the other leg of the bracket rests along and extends beyond the lower lateral member of the “I”. A second configuration of the strut has a cross-section substantially in the shape of an inverted “T”, with the two lateral legs of the “T” forming an obtuse angle with the longer, vertical leg of the “T”.
[0015] In use, once the framework for a geodesic dome is built, by connecting together a series of the inventive struts using a plurality of hubs which support the struts at their respective free ends to thereby create polygonal openings bound by a plurality of struts and hubs, the size and shape of the polygonal openings corresponding to the size and shape of the inventive tiles, the tiles of the invention are dropped into respective openings in the framework and secured thereto.
[0016] It is therefore an object of the invention to provide a tile for use in building a geodesic dome, wherein the tile is easy to manufacture and light weight, yet strong enough to support substantial loads.
[0017] It is another object of the invention to provide a strut which can, when linked together with additional struts, provide a bound opening designed to easily receive and securely support a tile of the invention thereon.
[0018] It is a further object of the invention to provide a strut and tile system, wherein once the struts are assembled to form a dome structure, the tiles can quickly and easily be dropped into openings bound by the assembled struts, and be secured to the struts.
[0019] These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0021] FIG. 1 is a top view of a first embodiment of the tile of the invention.
[0022] FIG. 2 is a cross-sectional side view of the tile of FIG. 1 in combination with a first embodiment of the strut of the invention.
[0023] FIG. 3 is a bottom view of the tile of FIG. 1 .
[0024] FIG. 3A is a top view of a separate sheet of finishing material for attachment to the underside of the tile of FIG. 1 .
[0025] FIG. 4 is a side view of the tile of FIG. 1 .
[0026] FIG. 5 is a top view of a second embodiment of the tile of the invention.
[0027] FIG. 6 is a side view of the tile of FIG. 5 in combination with a second embodiment of the strut of the invention.
[0028] FIG. 7 is a cross-sectional side view of the strut of FIG. 6 .
[0029] FIG. 8 is a cross-sectional view from below of the tile of FIG. 6 .
[0030] FIG. 9 is a bottom view of the tile of FIG. 6 .
[0031] FIG. 10 is a cross-sectional side view of a portion of two of the tiles of FIG. 6 in combination with the strut of FIG. 6 , as well as a sealing strip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] FIGS. 1 to 4 depict a first embodiment of the tile and strut construction system of the invention. FIG. 1 shows a top view of a tile 100 of the first embodiment. As viewed from above, the tile 100 is substantially triangular in shape, with three side edges 102 . Where each of the points of the triangle of the tile 100 would be, a small section is cut away leaving a curved free edge 104 whose purpose is to accommodate, during assembly of a geodesic dome, a rounded hub (not shown) that receives and supports a free end of the struts 200 which will serve to support and constrain the tile 100 of the invention when it is used to build a geodesic dome, as discussed further below. The upper surface of the tile 100 is three-dimensional, formed by three triangular portions 106 , with each portion having a lower, base side formed by a respective side edge 102 of the tile 100 , the triangular portions 106 each being angled upward until the upper corners meet together at a point 108 located at the center of the tile 100 , as viewed from above, giving the upper surface of the tile 100 the appearance of a three-faceted diamond. Because the tile and strut construction system is intended to build a geodesic dome that is earth-sheltered, this faceted shape of the upper surface of the tile 100 is important because it serves to deflect the weight of earth resting upon the tiles 100 away from the less supported center 108 of each tile 100 and towards the side edges 102 thereof, where the tile 100 is supported by struts 200 . While the tile 100 is being discussed in terms of a triangular shape, it is understood that the tile can be formed in any suitable polygonal shape.
[0033] FIG. 2 shows a cross-sectional side view of a portion of the tile 100 of the invention in combination with a strut 200 of the invention. The tile 100 can be seen to include triangular portion 106 forming the superior surface of the tile 100 , with a flange 110 extending beyond the side edge 102 of the tile 100 at the superior surface of the tile 100 . Cut into the corner where the side edge 102 and the inferior surface 112 of the tile 100 meet is a recess 114 that extends along a portion of the length of the side edge 102 . The lower portion of each side edge 102 includes such a recess 114 , whose purpose will be discussed shortly.
[0034] The strut 200 shown in FIG. 2 can be seen to include an I-beam having a vertical central member 202 , an upper lateral member 204 and a lower lateral member 206 . The upper and lower lateral members 204 , 206 serve as nailers, meaning that they are capable of receiving fasteners therein. If they are not made of a material, such as wood or plastic, that is soft enough to be nailed or screwed into directly, then the lateral members could have predrilled holes located at intervals along their length. This enables tile 100 which is supported by strut 200 to be securely attached thereto by means of a fastener. Strut 200 further includes an L-bracket 208 having a first leg 210 that extends along vertical central member 202 of the I-beam, and a second leg 212 that rests upon and extends beyond lower lateral member 206 of the I-beam. The L-bracket is made of a strong material, such as metal or a very strong plastic, which is capable of supporting significant weight thereon. In use, once a series of struts 200 and hubs (not shown) are assembled to provide the framework for a geodesic dome, with adjacent struts 200 and hubs together forming a substantially triangular opening, the tile 100 of the invention is dropped down within the opening. The recesses 114 on each of the edges 102 of the lower surface 112 of the tile 100 receive the L-bracket 208 of the strut, whereby the L-brackets 208 support the weight of the tile 100 , and each of the flanges 110 extending from the upper surface beyond side edges 102 of the tile 100 extend over and seal against the top of upper lateral member 204 of their respective struts 200 . The inferior surface 112 of tile 100 can be seen to extend below a lower surface of second leg 212 of L-bracket 208 , but not so far down as to be flush with the lower surface of lower lateral member 206 of strut 200 . This allows for a separate finishing sheet to be attached thereto, as will be discussed further below.
[0035] As seen in FIG. 3 , a series of reinforcement ribs 116 can be molded in unitary fashion into the cavity formed by triangular portions 106 and side edges 102 of the tile 100 . These ribs 116 add strength to the tile 100 while minimizing its weight. The size, number, shape, and arrangement of the ribs 116 shown in the drawings are to be considered merely illustrative. Any size, number, shape, and arrangement of the ribs determined to be desirable are considered to be within the scope of the invention. To further enhance the strength of the tile 100 , the tile 100 may optionally be reinforced by the inclusion of elements of a stronger material, such as by the inclusion of steel re-bars 105 , as seen in phantom in FIG. 1 .
[0036] It is desirable for the interior surface of the dome to be a smooth, finished surface that is aesthetically pleasing. As seen in FIG. 3A , a separate sheet of finishing material 120 sized and shaped to cover the underside of the tile 100 is provided with a plurality of first structural elements 122 located on a superior surface thereof. These first structural elements 122 are designed to mate with corresponding second structural elements 118 positioned in corresponding locations on the underside of tile 100 , whereby positioning of separate sheet 120 against the underside of tile 100 such that first structural elements 122 mate with second structural elements 118 causes separate sheet 120 to quickly and easily be secured to the underside of the tile 100 , thereby providing an aesthetically pleasing finished interior on the dome. It is understood that the number and location of structural elements 118 , 122 shown in the drawing are merely illustrative in nature, and that any suitable number and location of such structural elements is considered to be within the scope of the invention. Similarly, any type of mating structural elements 118 , 122 that will enable the separate sheet of finishing material 120 to be securely fastened to the underside of tile 100 is considered to be within the scope of the invention.
[0037] If a builder prefers to provide some other form of finished surface, they need merely forego use of the separate sheet of finishing material 120 and attach whatever other form of finishing is desired, such as drywall or paneling, to the underside of the tile 100 . This is not difficult to do because the tile 100 of the invention may be screwed or nailed into.
[0038] In use, a framework for a geodesic dome will be constructed by taking a plurality of the struts 200 of the invention and supporting them at their free ends using hubs (not shown), with each hub typically supporting 4 , 5 , or 6 struts 200 , whereby the struts and hubs together form a series of substantially triangular openings all over the framework of the dome. A tile 100 of the invention is dropped into each of the substantially triangular openings with the flanges 110 of each tile 100 sealing to an upper surface of the adjacent struts 200 and the weight of each tile 100 being supported by the L-brackets 208 on the adjacent struts 200 . Each tile 100 is then secured to its adjacent struts 200 using a plurality of fasteners, such as nails or screws, through the lateral members of the struts 200 . The interior surface of the dome will be finished, either by securing the separate sheet of finishing material 120 to the underside of the tile 100 using the structural elements 118 , 122 provided, or by securing an alternative finishing material to the underside of each tile using an alternative means of fastening, such as screws.
[0039] A second embodiment of the tile and strut construction system of the invention is seen in FIGS. 5 to 10 . FIG. 5 shows a top view of a tile 300 of the second embodiment of the invention. As viewed from above, the tile 300 is substantially triangular in shape, with three side edges 302 . Where each of the points of the triangle of the tile 300 would be, a small section is cut away leaving a curved free edge 304 whose purpose is to accommodate, during assembly of a geodesic dome, a rounded hub (not shown) that receives a free end of the struts 400 which will serve to support and constrain the tile 300 of the invention when it is used to build a geodesic dome, as discussed further below. The upper surface of the tile is three-dimensional, formed by three triangular portions 306 , with each portion having a lower, base side formed by a respective side edge 302 of the tile 300 , the triangular portions 306 each being angled upward until the upper corners meet together at a point 308 located at the center of the tile 300 , as viewed from above, giving the upper surface of the tile 300 the appearance of a three-faceted diamond. While the tile 300 is being discussed in terms of a triangular shape, it is understood that the tile can be formed in any suitable polygonal shape.
[0040] FIG. 6 shows a side view of the tile 300 of the invention in combination with two struts 400 of the invention. The tile 300 can be seen to include triangular portion 306 forming the superior surface of the tile 300 . Cut into the corner where the side edge 302 and the inferior surface 312 of the tile 300 meet is a recess 314 that extends along the full length of the side edge 302 . The lower portion of each side edge 302 includes such a recess 314 , whose purpose will be discussed shortly. The side edges 302 of tile 300 can be seen to be beveled 303 , being wider at the top than at the bottom. This beveling facilitates the mating of the tiles 300 with adjacent struts 400 at the appropriate angle necessary for formation of the dome.
[0041] FIG. 7 shows a side edge view of strut 400 , whose cross-section is substantially in the shape of an inverted “T”, with two lateral legs 404 each forming an obtuse angle with the longer, vertical leg 402 of the “T”, the obtuse angle typically being less than 100 degrees. While each of the lateral legs 404 is shown in this Figure to form identical obtuse angles with vertical leg 402 , this is not necessarily the case. It is possible that each of the lateral legs 404 in strut 400 form a different obtuse angle with vertical leg 402 from the obtuse angle formed by the other lateral leg 404 . As seen in FIG. 6 , each of the recesses 314 of the tile 300 receives one of the lateral legs 404 of an adjacent strut 400 , whereby the inferior surface 312 of tile 300 extends down below the recess 314 to be flush with a lower surface of lateral leg 404 of strut 400 . The strut 400 of this embodiment would be made of any suitable material that is strong enough to support tiles 300 thereon, including, but not limited to steel. Additionally, because the tile 300 to be used with strut 400 is molded of plastic, it is possible, rather than having the lateral legs 404 form an obtuse angle with vertical leg 402 , to have lateral legs 404 made to form a right angle with vertical leg 402 , with tile 300 formed to compensate by changing the angle of the bevel 303 and the recess 314 .
[0042] As seen in FIG. 8 , a series of reinforcement ribs 316 can be molded in unitary fashion into the cavity formed by triangular portions 306 and side edges 302 of the tile 300 . These ribs add strength to the tile while minimizing its weight. The size, number, shape, and arrangement of the ribs shown in the drawings are to be considered merely illustrative. Any size, number, shape, and arrangement of the ribs determined to be desirable are considered to be within the scope of the invention. To further enhance the strength of the tile 300 , the tile 300 may optionally be reinforced by the inclusion of elements of a stronger material, such as by the inclusion of steel re-bars 305 , as seen in phantom in FIG. 5 .
[0043] FIG. 9 shows a bottom view of the tile 300 . It can be seen that this embodiment may me manufactured to include a molded, unitary solid lower finished surface 313 which would be flush with a lower surface of lateral legs 404 of the struts 400 supporting it, whereby upon assembly of the tiles 300 to the struts 400 to form a dome (not shown), the interior surface of the dome would have a smooth, finished surface, eliminating the need to cut and fashion sheetrock or some other finishing material to each of the individual panels of the completed dome. In the alternative, as is done in the first embodiment, the lower surface 318 may be manufactured in the form of a separate sheet of finishing material sized and shaped to mate with the underside of tile 300 , the separate sheet of finishing material including structural elements that cooperate with mating structural elements on the underside of tile 300 to allow the separate sheet of finishing material to quickly and easily attach to the underside of the tile 300 , preferably by snapping into place thereon.
[0044] FIG. 10 shows a cross-sectional side view of strut 400 with two tiles 300 supported thereby. Because the tile 300 of the second embodiment does not have an upper flange to form a seal with the adjacent strut 400 (as the tile 100 of the first embodiment does), after assembly of the tiles 300 on opposing sides of a strut 400 , a sealing strip 500 , typically made of plastic, would be placed over the seams of the tiles 300 and the strut 400 . The sealing strip 500 could attach to the tiles 300 themselves, and/or to the exposed end of vertical leg 402 of strut 400 .
[0045] In use, a framework for a geodesic dome will be constructed by taking a plurality of the struts 400 of the invention and supporting them at their free ends using hubs (not shown), with each hub typically supporting 4 , 5 , or 6 struts 400 , whereby the struts and hubs together form a series of substantially triangular openings all over the framework of the dome. A tile 300 of the invention is dropped into each of the substantially triangular openings with each lateral leg 404 of each strut 400 being received within a respective recess 314 of the tile, with the weight of each tile 300 being supported by the lateral legs 404 of the adjacent struts 400 . Each tile 300 is then secured to its adjacent struts 400 using a plurality of fasteners, such as nails or screws, through the lateral members of the struts 400 . If the tile 300 includes an integrally molded smooth finishing surface on its underside, then no further finishing work need be done. If the tile 300 does not include an integrally molded smooth finishing surface on its underside, then the interior surface of the dome will be finished, either by securing the separate sheet of finishing material to the underside of the tile 100 using mating structural elements provided, or by securing an alternative finishing material to the underside of each tile using an alternative means of fastening, such as screws.
[0046] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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The present invention sets forth a tile and strut construction system for a geodesic dome. The tile has a generally triangular shape, with the corners cut out to accommodate hubs which retain supporting struts in position. The tile has a faceted 3-dimensional upper surface, integrally molded reinforcing ribs, a recess in the lower surface at each of its 3 edges.
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BACKGROUND OF THE INVENTION
The invention concerns a mold jaw half for a corrugator for the production of transversely ribbed tubes, as are used for example as installation tubes.
DE 200 09 030 U1 discloses a mold jaw half for a corrugator for the production of transversely ribbed tubes, wherein the mold jaw half has two mutually spaced end faces which are arranged in a common plane, and a semicylindrical base surface connecting the two end faces. The semicylindrical base surface of the mold jaw half is provided with ridges and troughs or channels, which alternate in the axial direction. Releasably mounted to the ridges and in the channels are molding insert elements in the form of a semicircular arc and which each have two diametrally oppositely disposed molding element end faces which are in planar alignment with the end faces of the mold jaw halves if they are arranged precisely correctly. In the case of that known mold jaw half the molding insert elements of a semicircular arcuate configuration are guided movably in their peripheral direction so that they can undesirably project from the respective end face of the mold jaw half.
EP 0 544 680 B1 discloses an apparatus, that is to say a corrugator for the extrusion of tubes of thermoplastic plastic with smooth inner and outer walls which are free from any projecting ribs, the height of which is greater than the thickness of the tube. That apparatus has molding blocks which provide a forwardly moving molding tunnel for molding the tube. The molding tunnel has an upstream end and a downstream end and a cylindrical longitudinal tunnel passage extending between those ends. The molding blocks of that known apparatus are formed by co-operating molding block portions which close at the upstream end of the molding tunnel in order to provide a closed molding block with a molding block bore forming a part of the longitudinal tunnel passage. The molding block portions open at the downstream end of the molding tunnel to release the tube which has been shaped within the longitudinal molding tunnel. The cylindrical bore walls of the molding blocks and thus the wall of the tunnel bore are provided with shallow corrugations for assisting with the transportation movement of the shaped tube. The depth of the corrugations is small in comparison with the thickness of the tube and the width thereof is greater than the depth. The corrugations have alternately shallow grooves and crests, the width of the grooves being at least as great as that of the crests. The grooves and the crests are of a rectangular cross-sectional profile. The corners of the grooves and crests can be rounded off or may involve a curved contour.
A corrugator for the production of tubes, in particular corrugated, that is to say transversely ribbed, tubes, with at least two successions of circulating molding jaws which form a molding passage along a predetermined portion is known from DE 199 14 974 A1. The successions of molding jaws are guided in associated circulatory guide means. The apparatus has at least one change-over molding jaw with a different tube molding configuration, wherein the apparatus has at least one change device along at least one of the circulating guide means.
EP 0 435 446 A2 describes molding jaw halves for a corrugator for the production of transversely ribbed tubes having a plurality of sub-blocks which are fixedly connected together. Each sub-block has an arcuate molding surface which has not more than one corrugation length of ribs and channels. Each sub-block also has two end faces spaced from each other in the longitudinal direction. A vacuum passage is provided at an end face of each sub-block. In the assembled condition of the sub-blocks the vacuum passages form vacuum ducts, leading to mold channels which can be brought into flow communication with an external vacuum source.
U.S. Pat. No. 3,784,346 and U.S. Pat. No. 3,864,446 disclose corrugators or mold jaw halves for corrugators, wherein the respective mold jaw half has two mutually spaced end faces arranged in a common plane and a semicylindrical base surface which connects the two end faces and to which are mounted molding insert elements determining the outside surface of the transversely ribbed tube to be produced. Those molding insert elements involve relatively short elements so that the ribs of the transversely ribbed tube to be produced can be formed with correspondingly short recesses.
DE 199 46 571 C1 describes an apparatus for the production of transversely ribbed tubes. The apparatus has mold jaw halves which move along two paths which are closed in themselves and they form a common mold section and two return sections. Provided at each of the two return sections is a respective turning device at which two mold jaw halves are disposed, by means of a holding and release device. One of those mold jaw halves has a socket contour so that this apparatus can be used to produce transversely ribbed tubes with sockets.
WO 93/25373 discloses a corrugator having mold jaw halves forming a common molding tunnel, wherein the tunnel has a number of mold cavities which are provided in mutually parallel relationship. The mold cavities are connected to a vacuum source, wherein the vacuum can be independently controlled in each mold cavity.
Apparatuses, that is to say corrugators, for the production of transversely ribbed tubes with mold jaw halves which have two mutually spaced end faces arranged in a common plane and a semicylindrical base surface connecting the two end faces are also known for example from DE 197 02 637 C1, DE 197 02 645 C1 and DE 197 02 547 C1.
An apparatus, that is to say a corrugator, for the production of a transversely ribbed tube which can be opened in its longitudinal direction and closed again is described in DE 199 16 641 A1. For that purpose, the transversely ribbed tube produced with that known apparatus has a hook profile and a counterpart hook profile which extend in the longitudinal direction of the corrugated tube. The corrugator of that known apparatus has first and second mold jaw halves, wherein the first mold jaw halves each have a respective radially stepped longitudinal recess which has a first recess to provide the hook profile and a second recess to receive an insert. The insert is provided with a longitudinal channel at its inward side to form the counterpart hook profile.
DE 199 22 726 A1 discloses an apparatus for the production of transversely ribbed tubes. That known apparatus has chill mold halves. The chilled mold halves each have a main body comprising a metal with a higher level of thermal conductivity and of lower specific weight than steel. The respective main body is provided to receive a core, that is to say a mold jaw half. The respective mold jaw half has two mutually spaced end faces arranged in a common plane and a semicylindrical base surface connecting the two end faces. The semicylindrical base surfaces form along a common molding passage a mold recess in which the transversely ribbed tubes are shaped. The mold jaw halves have vacuum passages. Specific respective mold jaw halves are required for the production of transversely ribbed tubes of respectively different configurations.
The object of the invention is to provide a mold jaw half for a corrugator for the production of transversely ribbed tubes, wherein the mold jaw halves are combined or can be combined with molding insert elements which can be easily very reliably positioned and fixed on the respective mold jaw half.
SUMMARY OF THE INVENTION
The foregoing object is achieved by way of the present invention by providing a mold jaw half for a corrugator for the production of transversely ribbed tubes, wherein the mold jaw half has two mutually spaced end faces arranged in a common plane and a semicylindrical base surface which connects the two end faces and to which there are releasably mounted molding insert elements which are in the shape of a semicircular arc and which determine the outside surface of the transversely ribbed tube and which each have two diametrally oppositely disposed molding element end faces which are in planar alignment with the end faces of the mold jaw half, wherein each of the two end faces of the mold jaw half, adjoining the semicylindrical base surface, have a number of first recesses, which corresponds to the number of molding insert elements, and the two molding element end faces of the respective molding insert element, adjoining the two end faces of the mold jaw half, are each provided with a respective second recess, wherein a fixing element extends between the respective first recess and the associated second recess for fixing the respective molding insert element to the mold jaw half.
In general, in mold jaw halves for a corrugator for the production of transversely ribbed tubes, the semicylindrical base surface connecting the two end faces of the mold jaw half is itself directly and immediately formed with transverse ribs and transverse channels which alternate in the axial direction of the mold jaw half, in a fashion corresponding to the outside surface of the transversely ribbed tube to be produced. Mold jaw halves of that configuration are therefore only suitable for the production of transversely ribbed tubes of a given tube diameter and a given lengthwise corrugation configuration. In comparison for example first-mentioned DE 200 09 030 U1 discloses a mold jaw half with molding insert elements in order to be able to produce transversely ribbed tubes of various tube diameters and/or with various longitudinal profile configurations, by a choice of the respectively appropriate molding insert elements in combination with the respectively associated mold jaw half. In the case of that known mold jaw half the molding insert elements however are only secured to prevent unwanted movement in the radial direction, that is to say radially centrally into the mold passage, when the mold jaw half and the associated molding insert elements are temporarily connected together in positively locking relationship for example by dovetail connections or the like. That positively locking connection however means that it is not possible to prevent mobility of the respective molding insert element in its peripheral direction, which means that, along the common molding path section of the corrugator, or in particular along its entry or initial portion, damage can occur to molding insert elements which project from the respective molding jaw half. It is here that the invention provides a remedy, with a molding jaw half for a corrugator for the production of transversely ribbed tubes, wherein the mold jaw half has two mutually spaced end faces arranged in a common plane and a semicylindrical base surface which connects the two end faces and to which there are releasably mounted molding insert elements which are in the shape of a semicircular arc and which determine the outside surface of the transversely ribbed tube and which each have two diametrally oppositely disposed molding element end faces which are in planar alignment with the end faces of the mold jaw half, wherein each of the two end faces of the mold jaw half, adjoining the semicylindrical base surface, have a number of first recesses, which corresponds to the number of molding insert elements, and the two molding element end faces of the respective molding insert element, adjoining the two end faces of the mold jaw half, are each provided with a respective second recess, wherein a fixing element extends between the respective first recess and the associated second recess for fixing the respective molding insert element to the mold jaw half. By means of the respective fixing element, the associated molding insert element is releasably secured to the semicylindrical base surface of the mold jaw half so that the molding insert elements are reliably prevented from undesirably projecting from an end face of the corresponding mold jaw half. The mold jaw half of such a configuration also affords the advantage that individual molding insert elements can be easily replaced by other molding insert elements, without taking up a great deal of time, in order to be able to convert the mold jaw halves of a corrugator for the production of transversely ribbed tubes of a given tube diameter and a given lengthwise corrugation configuration, while involving relatively short conversion times.
In the case of the mold jaw half according to the invention, the semicylindrical base surface of the mold jaw half can have crests and channels which alternate in the axial direction, wherein first molding insert elements having a convex cross-sectional edge contour can be releasably mounted to the crests and second molding insert elements having a concave cross-sectional edge contour can be releasably mounted in the channels. In that case the first and the second cross-sectional edge contours can adjoin each other directly, while another option is that the first and the second cross-sectional edge contours of the first and second molding insert elements are each at a respective given spacing from each other, which spacing is bridged over by a corresponding portion of the respective mold jaw half. While in the first-mentioned case therefore the first and second molding insert elements alone determine the outside surface of the transversely ribbed tube to be produced, the last-described configuration provides that the first and second molding insert elements, jointly with the portions bridging same of the respective mold jaw half, determine the outside surface of the transversely ribbed tube to be produced.
In the case of the mold jaw half according to the invention, another option provides that the semicylindrical base surface of the mold jaw half is simply semicylindrical with mutually axially spaced channels of small depth, wherein a molding insert element is associated with each channel. In that case each molding insert element axially centrally has a convex cross-sectional rib edge contour and adjoining same at both sides a respective half concave cross-sectional channel edge contour. In that way it is possible to produce for example transversely ribbed tubes with transverse ribs and transverse channels which are at least approximately equidistantly spaced from each other, of at least approximately identical axial dimensions. It is however also possible that arranged between molding insert elements which have a convex cross-sectional rib edge contour and adjoining same on both sides thereof a respective half concave cross-sectional rib edge contour is at least one half-annular molding element, wherein the at least one half-annular molding element steplessly adjoins the adjacent molding insert element with a convex cross-sectional rib edge contour. A mold jaw half of such a configuration makes it possible to produce ribbed tubes with transverse channels which are at a large axial spacing from each other, in comparison with the internal channel width.
It is advantageous if each molding insert element is provided at the rear side with a securing member which is fitted into a securing channel, adapted thereto in respect of cross-section, in the semicylindrical base surface of the mold jaw half. It is particularly advantageous in that respect if the securing member and the securing channel adapted thereto in respect of shape are of a simply rectangular configuration, because it is then possible for the respective molding insert element to be easily fitted into the semicylindrical base surface of the mold jaw half from the side, without the need for the molding insert element in the form of a semicircular arc to be introduced in its peripheral direction into the associated securing channel in the mold jaw half. The amount of time and work involved in combining the mold jaw half with molding insert elements is consequently correspondingly slight. It will be appreciated that it is also possible for the securing member of the respective molding insert element and the respective securing channel, which is adapted thereto in respect of shape, in the semicylindrical base surface of the mold jaw half to be provided with undercut configurations, for example in the form of dovetail guides.
Desirably the molding insert elements have vacuum slots and the respective mold jaw half desirably has a vacuum passage system. The vacuum passage system is in flow communication with the vacuum slots. In this case the vacuum passage system can have at least one first passage portion which opens out of one of the end faces of the mold jaw half and which can be connected to a vacuum source and at least one second passage portion which is connected to the first passage portion and which opens out into the vacuum slots.
BRIEF DESCRIPTION OF THE DRAWINGS
Further details, features and advantages will be apparent from the description hereinafter of embodiments illustrated in the drawing of the mold jaw half according to the invention for a corrugator for the production of transversely ribbed tubes. In the drawing:
FIG. 1 is a perspective view of a portion of a first embodiment of the mold jaw half for the production of a transversely ribbed tube,
FIG. 2 is a cross-section through the portion of the mold jaw half shown in FIG. 1 ,
FIG. 3 shows the detail III in FIG. 2 on a larger scale,
FIG. 4 shows a front view of the mold jaw half of FIG. 1 viewing in the direction of the arrow IV, without the fixing elements immovably fixing the molding insert elements to the mold jaw half,
FIG. 5 shows a front view corresponding to FIG. 4 with the fixing elements for fixing the molding insert elements to the mold jaw half,
FIG. 6 is a front view similar in principle to FIG. 4 of another embodiment of the mold jaw half with molding insert elements for producing a transversely ribbed tube with transverse channels which are of a small axial internal width in comparison with the axial spacing of adjacent transverse channels,
FIG. 7 shows the mold jaw half of FIG. 6 , similarly to the mold jaw half of FIG. 5 , also showing the fixing elements for fixing the molding insert elements to the mold jaw half,
FIG. 8 shows a perspective view of an embodiment of the mold jaw half with molding insert elements, wherein the semicylindrical base surface of the mold jaw half is of a simple semicircular-cylindrical configuration with axially mutually spaced channels,
FIG. 9 shows the mold jaw half of FIG. 8 , illustrating a molding insert element spatially spaced from the mold jaw half, that is to say in an exploded view,
FIG. 10 shows an exploded perspective view similar in principle to FIG. 9 of an embodiment of the mold jaw half, wherein provided between two axially outer molding insert elements with a rib edge contour is a molding insert element which is in the form of a semi-annular molding element, without a rib contour,
FIG. 11 shows a mold jaw half for the production of a transversely ribbed tube—similar to the mold jaw half of which part is shown in FIG. 7 , wherein however the semicylindrical base surface of the mold jaw half—as in the structures shown in FIGS. 8 through 10 —is of a simple semicircular-cylindrical configuration with axially mutually spaced channels,
FIG. 12 shows the detail of FIG. 11 on a larger scale,
FIG. 13 shows a perspective view of a mold jaw half similar to that shown in FIG. 1 , the molding insert elements having vacuum slots,
FIG. 14 shows a view of the detail XIV in FIG. 13 on a larger scale,
FIG. 15 shows a front view of a mold jaw half similar to those shown in FIGS. 8 through 10 , the molding insert element having vacuum slots,
FIG. 16 showing a section along line XVI-XVI in FIG. 15 through the mold jaw half with its molding insert elements and the fixing elements fixing the molding insert elements in the mold jaw half,
FIG. 17 shows the detail XVII of FIG. 16 on a larger scale,
FIG. 18 is a view similar to FIG. 15 of an embodiment of the mold jaw half, wherein however the vacuum slots extend along the entire peripheral extent of the molding insert elements,
FIG. 19 is a section taken along line XIX-XIX in FIG. 18 , and
FIG. 20 is a section taken along line XX-XX in FIG. 18 .
DETAILED DESCRIPTION
FIG. 1 is a perspective view showing a portion of a configuration of the mold jaw half 10 for a corrugator for the production of transversely ribbed tubes. The mold jaw half 10 has two mutually spaced end faces 12 which are provided in a common plane. Only one of those end faces 12 is shown in FIG. 1 . The mold jaw half 10 also has a semicylindrical base surface 14 which extends between the two end faces 12 , that is to say it connects them together. The semicylindrical base surface 14 of the mold jaw half 10 has crests 16 and channels 18 which alternate in the axial direction of the mold jaw half 10 . Molding insert elements 20 are fitted to the crests 16 . Second molding insert elements 22 are mounted in the channels 18 . The molding insert elements 20 have a convex cross-sectional edge contour 24 and the molding insert elements 22 have a concave cross-sectional edge contour 26 . The crests 16 and the channels 18 of the semicylindrical base surface 14 of the mold jaw half 10 and the convex cross-sectional edge contour 24 of the molding insert elements 20 and the concave cross-sectional edge contour 26 of the molding insert elements 22 are of such configurations that the cross-sectional edge contours 24 and 26 directly and immediately steplessly adjoin each other. The edge contours 24 and 26 of the molding insert elements 20 and 22 determine the outside surface of the transversely ribbed tube to be produced.
As can also be seen in particular from FIGS. 2 and 3 the molding insert elements 20 and 22 have end faces 28 which are in diametrally opposite relationship and which are disposed in a common plane. The end faces 28 of the molding insert elements 20 and 22 are in planar alignment with the end faces 12 of the mold jaw half 10 , that is to say they define a common plane with the end faces 12 .
Each of the two end faces 12 of the mold jaw half 10 is provided with a number of first recesses 30 which adjoin the semicylindrical base surface 14 of the mold jaw half 10 , the number of first recesses 30 corresponding to the number of molding insert elements 20 and 22 . The two end faces 28 of the respective molding insert element 20 , 22 have second recesses 32 provided in adjoining relationship with the corresponding end face 12 of the mold jaw half 10 , so that the first and the second recesses 30 and 32 respectively form a common recess which serves to receive a fixing element 34 . The fixing elements 34 are for example in the form of a small plate member with a stepped hole 36 therethrough. A screw 40 is screwed through the respective through hole 36 into an associated blind screwthreaded hole 38 in the mold jaw half 10 in order to fix the respective fixing element 34 in the first recess 30 and to fixedly connect the associated molding insert element 20 or 22 to the mold jaw half 10 in such a way that the end faces 12 of the mold jaw half 10 and the end faces 28 of the molding insert elements 20 , 22 are in mutually planar alignment, as can be clearly seen from FIGS. 2 and 3 . The fixing elements 34 are of such dimensions that the face 42 thereof is also in planar alignment with the end faces 12 and 28 .
FIG. 4 shows a portion of a mold jaw half 10 having a semicylindrical base surface 14 which—as in the structure shown in FIG. 1 —has crests 16 and channels 18 , wherein provided on the crests 16 are molding insert elements 20 and provided in the channels 18 are molding insert elements 22 —corresponding to the configuration shown in FIG. 1 —, the cross-sectional edge contours 24 and 26 of which directly and immediately adjoin each other. FIG. 4 shows in particular vacuum slots 44 which are provided in the molding insert elements 22 50 that, in the production of the respective transversely ribbed tube, the extruded tube material is caused to bear closely against the concave cross-sectional edge contour 26 of the molding insert elements 22 . In that case, as will be appreciated, the tube material automatically bears closely against the convex cross-sectional edge contour 24 of the molding insert elements 20 . The vacuum slots 44 are in flow communication with a vacuum passage system (not shown in FIG. 4 ) of the associated mold jaw half 10 . That vacuum passage system is further described hereinafter with reference to FIG. 20 where it is identified by reference numeral 46 .
FIG. 4 also shows that the molding insert elements 20 and 22 are each provided at their rear side, that is to say at their side which is radially remote from the cross-sectional edge contour 24 , 26 , with a securing member 48 . In this embodiment the securing members 48 have a trapezoidal cross-section in the manner of a dovetail guide. The semicylindrical base surface 14 of the mold jaw half 10 , which has crests 16 and channels 18 , is provided with securing channels 50 which correspond in cross-section to the securing members 48 .
The same details are identified in each of FIGS. 1 through 3 and in FIG. 4 by the same reference numerals.
FIG. 5 only differs from FIG. 4 in that the molding insert elements 20 and 22 are immovably secured, that is to say fixed, to the semicylindrical base surface 14 of the mold jaw half 10 , by means of the fixing elements 34 . Identical features are identified in FIG. 5 by the same reference numerals as in FIGS. 1 through 4 so that there is no need for all those features to be described in detail once again with reference to FIG. 5 .
FIGS. 6 and 7 show an embodiment of the mold jaw half 10 without fixing elements (see FIG. 6 ) and with fixing elements 34 (see FIG. 7 ), wherein the semicylindrical base surface 14 of the mold jaw half 10 —like the structures shown in FIGS. 1 through 5 —has axially alternate crests 16 and channels 18 . In the embodiment shown in FIGS. 6 and 7 however a molding insert element 20 with a convex cross-sectional edge contour 28 is only mounted to one crest 16 while the remaining crests 16 and channels 18 are combined with molding insert elements 52 and 54 which provide for a smooth surface 56 for the mold jaw half 10 and thus a correspondingly smooth outside surface for the transversely ribbed tube to be produced. In other respects the design of the mold jaw half 10 shown in FIGS. 6 and 7 is similar to that shown in FIGS. 4 and 5 so that there is no need for all features which are identified in FIGS. 6 and 7 by the same reference numerals as in FIGS. 4 and 5 to be described once again in detail in connection with FIGS. 6 and 7 .
FIGS. 4 and 5 and FIGS. 6 and 7 are intended to serve in particular to make it clear that the mold jaw half 10 can be combined as desired with any molding insert elements 20 , 22 , 52 , 54 in order to produce transversely ribbed tubes having the respectively desired outside surface. The respective molding insert elements 20 , 22 , 52 , 54 can also be replaced as desired by other corresponding molding elements. For that purpose, it is only necessary to release the corresponding fixing elements 34 , replace the molding elements and fix the new molding elements in place again on the mold jaw half 10 by means of the fixing elements 34 .
FIGS. 8 and 9 show a perspective view of a mold jaw half 10 in which the semicylindrical base surface 14 does not have crests and channels but is of a simply semicircular-cylindrical configuration with axially mutually spaced channels 58 , with a molding insert element 60 being associated with each channel 58 . The respective molding insert element 60 axially centrally has a convex cross-sectional edge contour 62 , which is adjoined at each of its two sides by a respective half concave cross-sectional edge contour 64 . In the assembled condition the molding insert elements 60 adjoin each other closely and steplessly in order to form an inside surface corresponding to the outside surface of the transversely ribbed tube to be produced. The molding insert elements 60 are again fixed in the mold jaw half 10 by means of fixing elements 34 or by means of screws 40 for securing the fixing elements 34 in the recesses 30 in the end faces 12 of the mold jaw half 10 .
This design configuration also provides that each molding insert element 60 is provided on its rear side with a securing member 48 which extends in the peripheral direction along the associated molding insert element 60 and which is provided adjoining the respective end face 28 with a second recess 32 (see for example FIGS. 2 and 3 ).
FIG. 10 is a perspective view of a mold jaw half 10 which differs from the embodiment shown in FIGS. 8 and 9 in particular in that a semi-annular molding element 66 is provided between molding insert elements 60 of which that shown at the right is spaced from the mold jaw half 10 , that is to say as an exploded view. While mold jaw halves 10 as shown in FIGS. 8 and 9 , in a per se known corrugator, are used to produce transversely ribbed tubes with corrugation troughs and corrugation crests in which the corrugation crests and the corrugation troughs are of at least approximately equal dimensions in the axial direction, mold jaw halves 10 as shown in FIG. 10 produce a transversely ribbed tube in which the corrugation crests are long axially in comparison with the axial length of the corrugation troughs.
Identical features are identified in FIGS. 8 , 9 and 10 by the same references as in FIGS. 1 through 7 so that there is no need for all those features to be described in detail once again with reference to FIGS. 8 through 10 .
FIGS. 11 and 12 are intended to show a design configuration for the mold jaw half 10 , wherein the semicylindrical base surface 14 between the two end faces 12 is of a semicircular-cylindrical configuration with axially mutually spaced channels 58 —similarly to the structures shown in FIGS. 8 , 9 and 10 . Fixed to the semicylindrical base surface 14 by means of fixing elements 34 or screws 40 are molding insert elements 68 , 70 which are suitable and intended for the production of a transversely ribbed tube—similarly to the structure shown in FIG. 7 .
FIGS. 13 and 14 show a mold jaw half 10 which is of a similar configuration to the mold jaw half shown in FIG. 1 , wherein the second molding insert elements 22 fixed in the channels 18 of the semicylindrical base surface 14 of the mold jaw half 10 have vacuum slots 44 .
Identical features are denoted in FIGS. 13 and 14 by the same references as in FIGS. 1 through 12 so that there is no need for all features to be described in detail once again with reference to FIGS. 13 and 14 .
FIG. 15 is an end view of a mold jaw half 10 —similar to the embodiments of the mold jaw half 10 which are shown in FIGS. 8 , 9 , 10 and 11 and 12 respectively—wherein the semicylindrical base surface 14 is of a semicircular-cylindrical configuration with axially mutually spaced channels 58 . As can be seen in particular from FIGS. 8 and 10 , the securing members 48 provided at the rear side of the molding insert elements 60 are of a simple configuration of rectangular cross-section. The securing channels 50 are of a corresponding configuration with a rectangular internal cross-section so that it is easily possible, without involving a great deal of time, for the molding insert elements 60 not to have to be threaded into the mold jaw half 10 in the peripheral direction, but rather it is possible for the molding insert elements 60 to be easily fitted from the side into the mold jaw half 10 . Thereafter the molding insert elements 60 are fixed by means of fixing elements 34 in the mold jaw half 10 , using screws 40 . The molding insert elements 60 have vacuum slots 44 .
FIG. 16 shows a section taken along line XVI-XVI in FIG. 15 through the mold jaw half 10 and through a molding insert element 60 fixedly connected thereto and through the two fixing elements 34 fixing the corresponding molding insert element 60 . FIG. 17 shows the detail XVII in FIG. 16 . Identical features are also denoted in FIGS. 15 through 17 by the same reference numerals as in FIGS. 1 through 14 .
FIG. 18 shows a mold jaw half 10 similar to that diagrammatically shown in FIG. 15 , but in this case the molding insert elements 60 have vacuum slots 44 extending along the entire peripheral extent of the respective molding insert element 60 , as can also be seen in particular from FIG. 20 . The vacuum slots 44 are in flow communication with the vacuum passage system 46 which is provided in the mold jaw half 10 and which has already been mentioned hereinbefore. The vacuum passage system 46 has a first passage portion 72 which can be connected to a vacuum source (not shown) and which opens out of one of the end faces 12 of the mold jaw half 10 in order to communicate the associated molding jaw halves 10 with the vacuum source. The first passage portion 72 is in flow communication with at least one second passage portion 74 which opens out into the vacuum slots 44 . If the vacuum slots 44 extend over the entire peripheral length of the respective molding insert element 60 , then a single second passage portion 74 can be sufficient. If the molding insert elements 60 —as shown for example in FIG. 15 —have short and mutually spaced vacuum slots 44 , it will be appreciated that it is then necessary for the respective vacuum slot groups to be associated with a respective associated second passage portion 74 .
The Figures of the drawings show various configurations of the mold jaw half 10 with different molding insert elements for producing corresponding transversely ribbed tubes, in which respect it will be appreciated that the invention is not limited to the embodiments illustrated in the drawings but is defined by the claims.
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A half-mold for a corrugator for making pipes with transverse ribs. The half-mold comprises two sides located spaced apart from each other and a semi-cylindrical base surface linking the two sides. Directly mounted forming elements bent in the shape of a semicircle which define the outer surface of the pipe with transverse ribs are removably fixed on the base surface. The directly mounted forming elements bent in the shape of a semicircle are removably fixed with fixing elements on the half-mold.
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RELATED APPLICATION
[0001] This application relies for priority upon Korean Patent Application No. 2001-46775, filed on Aug. 2, 2001, the contents of which are herein incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an EEPROM memory cell structure and a method of forming the same. More specifically, the invention is directed to an EEPROM memory cell structure and a method of forming the same, which can not only maintain operation characteristics, but also reduce area of an EEPROM cell.
BACKGROUND OF THE INVENTION
[0003] An EEPROM memory is a nonvolatile memory that is semi-permanently capable of retaining data in a memory cell even while power is not applied. In particular, the EEPROM memory is an electrically programmable and erasable memory device.
[0004] [0004]FIG. 1 is a top plan view showing a typical EEPROM memory cell, and FIGS. 2 and 3 are cross-sectional views taken along lines I-I and II-II of FIG. 1, respectively.
[0005] Referring to FIGS. 1 to 3 , the EEPROM memory cell consists of two transistors that are connected in series along an active region 11 formed long in one direction. One of the transistors is a sensing transistor having a floating gate 19 , and the other is a selection transistor having a single gate. A bit line contact 25 is connected to a drain region 35 of the selection transistor. A source region 21 of the selection transistor corresponds to a drain region of the sensing transistor. The drain region 21 of the sensing transistor is widened to the substrate under the floating gate 19 constituting the sensing transistor. The sensing transistor includes a tunnel insulation layer 23 surrounded by gate insulation layer 31 . The tunnel insulation layer 23 is interposed between the floating gate 19 and the drain region 21 . A source region 37 of the sensing transistor is widened to be connected to a common source line 39 . In the EEPROM memory cell array, the memory cells are arranged in a matrix of rows and columns. Gate electrodes of the selection transistors in a row are connected with each other to form a word line 13 across the active regions, whereas gate electrodes of the sensing transistors in a row are connected with each other to form a sensing line 15 across the active regions.
[0006] In particular, referring to FIGS. 2 and 3, the selection transistor includes the gate insulation layer 31 , the gate electrode, the drain region 35 , and the source region. The gate insulation layer 31 is interposed between the word line 13 and the active region. The word line 13 corresponds to the gate electrode of the selection transistor. The drain region 35 is formed by doping first-type impurity ions into one end of the active region. The bit line contact 25 is connected to the drain region 35 . The source region serves as the drain region of the sensing transistor.
[0007] The sensing transistor includes the gate insulation layer 31 and the tunnel insulation layer 23 formed on a substrate. The tunnel insulation layer 23 is surrounded by a region where the gate insulation layer 31 is formed. The floating gate 19 , a dielectric layer pattern 27 and a control gate (a gate electrode of the sensing transistor; 15 ) are sequentially formed on the gate insulation layer 31 and the tunnel insulation layer 23 . The common source line 39 is typically formed by doping first-type impurity ions at a high concentration. The common source line 39 is connected to the sensing transistor through the source region 37 . A substrate 10 is doped by second-type impurity ions at a low concentration. Generally, the bit line contact 25 is formed in a contact region and penetrates an interlayer insulation layer 29 to connect a bit line to the active region.
[0008] The floating gate 19 is formed wider than the active region enough to stretch over a device isolation layer. Also, the floating gate 19 is isolated from the substrate 10 by the gate insulation layer 31 . Likewise, the floating gate 19 is isolated from the control gate 15 by the dielectric layer pattern 27 and sidewall oxide layers 18 . Data may be stored in a memory cell by injecting and emitting electric charges in the floating gate 19 through the tunneling insulation layer 23 .
[0009] For example, while the common source line is grounded or floated and the bit line is grounded, high voltages of 15 to 20V are applied to a word line and the sensing line. Under such conditions, electrons in the substrate are injected into the floating gate through the tunneling insulation layer. That is, the memory cell is under a state of erasion. In this case, a threshold voltage of the sensing transistor is increased up to 3 to 7 V.
[0010] By contrast, while the common source line is at a low positive voltage or floated, high voltages are applied to the bit line and the gate line, and a zero voltage is applied to the sensing line. Under such conditions, the electrons in the floating gate are emitted through the tunneling insulation layer. Thus, a threshold voltage of the sensing transistor is decreased to −4 to 0V.
[0011] To improve erase and program operations of the memory cell, a coupling ratio (CR) must be high. The coupling ratio (CR) is defined as the following equation 1. ‘Cono’ is a capacitance of a capacitor comprising a control gate, a dielectric layer and a floating gate. ‘Ctun’ is a capacitance of another capacitor comprising a floating gate, a tunnel insulation layer and a substrate.
CR = Cono Cono + Ctun [ Equation 1 ]
[0012] Assuming that the ‘Ctun’ is a predetermined value, the coupling ratio (CR) is increased with the value ‘Cono’. Assuming that a dielectric ratio of the dielectric layer is a predetermined value, the capacitance is proportional to areas of opposite electrodes and inversely proportional to a thickness of the dielectric layer. Accordingly, where other conditions are the same, the area of the floating gate should be increased and the thickness of the dieletric layer should be decreased in order to improve the erase and program operations of the memory cell. However, as integration level of memory devices gradually increases, horizontal dimensions of the EEPROM memory cell should be reduced. Accordingly, it is difficult to widely form the floating gate on the substrate. Also, the dielectric layer must have a thickness sufficient to maintain an insulating reliability. Therefore, a thickness of the dielectric layer cannot be continuously decreased.
[0013] Meanwhile, due to a breakdown voltage limit, an electric field of the insulation layer cannot be continuously increased with an increase in a voltage applied to the control gate. In addition, the memory device must further comprise a voltage pumping circuit region so as to raise a voltage. And, various portions of a semiconductor device should be formed to endure a high voltage.
SUMMARY OF THE INVENTION
[0014] It is therefore a feature of the present invention to provide an EEPROM memory cell and a method of forming the same, which can erase and program data with reliability, and also can reduce each area of a cell region and a floating gate to achieve a high integration of a semiconductor device.
[0015] It is another feature of the present invention to provide an EEPROM memory cell and a method of forming the same, which can reduce a minimum value of an operating voltage in order to erase and program data with reliability.
[0016] The present invention is directed to an EEPROM memory cell that includes a floating gate that is conformally formed in a trench formed at a substrate.
[0017] The memory cell comprises a device isolation layer disposed on a predetermined region of the substrate to define an active region in one direction. Source and drain regions are separately formed in a predetermined region of the active region. The trench is formed at the active region between the source and drain regions. A word line crosses the active region between the trench and the drain region. The floating gate is conformally formed on a bottom and sidewalls of the trench. A sensing line crosses the floating gate and is disposed in parallel with the word line. A dielectric layer pattern is interposed between the sensing line and the floating gate, and a tunneling insulation layer pattern is interposed between the floating gate and the active region. A gate insulation layer is interposed between the word line and the active region, and disposed also in the vicinity of the tunneling insulation layer pattern between the word line and the active region. A cell junction region is formed in the active region between the word line and the sensing line.
[0018] In accordance with another aspect, the invention is directed to a method of fabricating an EEPROM memory cell that includes a floating gate that is conformally formed in a trench formed at a substrate. The method comprises forming a trench at a predetermined region of the substrate, forming a tunneling insulation layer pattern and a gate insulation layer on an entire surface of the substrate where the trench is formed. The tunneling insulation layer pattern is formed on a trench bottom or on a predetermined region adjacent to the trench. The gate insulation layer is formed on an entire surface of the substrate surrounding the tunneling insulation layer pattern. A first conductive layer is conformally formed on an entire surface of the substrate where the tunneling insulation layer pattern and the gate insulation layer are formed. Thereafter, a dielectric layer is conformally formed on the resultant structure where the first conductive layer is formed. The dielectric layer and the first conductive layer are successively patterned to form a floating gate and a dielectric layer pattern. The floating gate covers a bottom and sidewalls of the trench and the dielectric layer pattern is formed on the floating gate. A second conductive layer is then formed on an entire surface of the resultant structure where the floating gate and the dielectric layer pattern are formed. The second conductive layer is patterned to form a sensing line and a word line. The sensing line crosses the floating gate, while the word line is separated from the sensing line by a predetermined interval and formed in parallel with the sensing line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing and other objects, features and advantages of the invention will be apparent from the more particular description of a preferred embodiment 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.
[0020] [0020]FIG. 1 is a top plan view showing a typical EEPROM memory cell.
[0021] [0021]FIGS. 2 and 3 are cross-sectional views taken along lines I-I and II-II, respectively, of FIG. 1.
[0022] [0022]FIG. 4 is a top plan view showing an EEPROM memory cell in accordance with a first embodiment of the present invention.
[0023] [0023]FIGS. 5 and 6 are cross-sectional views taken along lines I-I and II-II, respectively, of FIG. 4.
[0024] [0024]FIGS. 7 through 17 are cross-sectional views illustrating a method of forming an EEPROM memory cell in accordance with the embodiment of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] [0025]FIG. 4 is a top plan view showing an EEPROM memory cell in accordance to a first embodiment of the present invention. FIGS. 5 and 6 are cross-sectional views taken along lines I-I and II-II of FIG. 4, respectively.
[0026] Referring to FIG. 4, a device isolation layer is formed to define an active region 111 in one direction. A common source line 139 is formed perpendicularly to the active region 111 . A bit line contact 125 is formed at the active region 111 . A sensing line 115 and a word line 113 are formed across the active region between the common source line 139 and the bit line contact 125 . A trench 120 is formed at the active region 111 under the sensing line 115 . Generally, an upper part of the trench 120 is formed wider than a bottom of the trench 20 . A floating gate 119 is formed over the trench 120 . The floating gate 119 is wider than the upper part of the trench 120 by a certain width to all directions. A tunneling insulation layer 123 is formed in the trench 120 . The tunneling insulation layer 123 is an insulation layer thinly formed to induce carrier tunneling. An impurity doped region 121 is formed at the trench bottom under the tunneling insulation layer 123 .
[0027] Referring to FIG. 5, a surface of the active region ( 111 of FIG. 4) excluding the bit line contact region 125 is covered with a gate insulation layer 131 that is a silicon oxide layer. The tunneling insulation layer 123 is formed in a portion of the trench bottom. The tunneling insulation layer 123 is formed thinner than the gate insulation layer 131 . The floating gate 119 is conformally formed on the trench 120 . The width of the floating gate 119 is wider than that of the trench 120 by a certain width. A dielectric layer pattern 127 is conformally formed on the floating gate 119 . Each sidewall of the floating gate 119 is covered with a sidewall oxide layer 118 . The sensing line 115 is formed to fill a gap region of the floating gate 119 and to cover a predetermined portion of the floating gate. The dielectric layer pattern 127 is interposed between the sensing line 115 and the floating gate 120 . The word line 113 is formed across the active region between the sensing line 115 and the bit line contact 125 . Lightly doped N-type regions 135 and 143 a are formed in the active region located at both sides of the word line 113 . A heavily doped N-type region 141 is formed in the active region under the bit line contact 125 . The heavily doped N-type region 141 is connected to the lightly doped N-type region 135 . The lightly doped N-type region 143 a between the sensing line 115 and the word line 113 is widened to a sidewall of the trench 120 . An N-type doped region 121 is formed at the bottom of the trench 120 in the substrate. The lightly doped N-type region 143 a is connected to an N-type doped region 121 . The lightly doped N-type region 143 a and the N-type doped region 121 correspond to a cell junction region. The sidewall of the trench 120 facing the common source line 139 forms a channel of the sensing transistor. A source region 137 is formed between the common source line 139 and the floating gate 119 . The source region 137 is a lightly doped region and the common source line 139 is a heavily doped region. A spacer 145 is formed on sidewalls of the sensing line and the word line. Both gate lines are covered with an interlayer insulation layer 129 .
[0028] Referring to FIG. 6, a sensing transistor is formed between device isolation layers 12 . The device isolation layer 12 is formed at both sides of the active region. A gate insulation layer 131 , a floating gate 119 , a dielectric layer pattern 127 and a sensing line 115 are formed on the active region. The gate insulation layer 131 is formed in the trench 120 to be in contact with the substrate of the trench bottom. The floating gate 119 and the dielectric layer pattern 127 are extended from both sidewalls of the trench to its peripheral region by a certain width. The sensing line 115 is formed to fill a gap region surrounded by the dielectric layer pattern 127 and to cover the dielectric layer pattern 127 . The sidewall of the floating gate 119 is covered with a sidewall oxide layer 118 or a dielectric layer. The sidewall oxide layer 118 or the dielectric layer is formed during an annealing process. As a result, the floating gate 119 remains isolated from the sensing line 115 . An N-type doped region 121 is formed in the substrate constituting the trench bottom.
[0029] [0029]FIGS. 7 through 17 are cross-sectional views for illustrating a method of forming an EEPROM memory cell shown in FIG. 4.
[0030] Referring to FIG. 7, an etch-stop layer 8 and a pad oxide layer 9 are formed on a substrate 10 having a device isolation layer. The etch-stop layer 8 is composed of silicon nitride. A first photoresist pattern 7 as an etch mask is formed on the substrate 10 . Thereafter, the etch-stop layer 8 , the pad oxide layer 9 and the silicon substrate 10 are successively etched to form a trench 6 at the sensing transistor region of the active region. The substrate is a P-type substrate on which P-type impurity ions are lightly doped. The first photoresist pattern 7 is removed after etching the etch-stop layer or the pad oxide layer, or after forming the trench 6 .
[0031] Referring to FIG. 8, the remaining etch-stop layer 8 and pad oxide layer 9 are removed from the substrate 10 having the trench 6 . The substrate surface is thermally oxidized to form a gate insulation layer 131 . P-type impurity ions may be implanted before or after the thermal oxidation in order to prevent a punch through phenomenon and adjust an operating voltage.
[0032] Referring to FIG. 9, a second photoresist pattern 52 is formed to expose the trench bottom. N-type impurity ions are then implanted into the substrate 10 . As a result, an N-type doped layer is formed. In this case, impurity ions should be implanted at a high energy sufficient to penetrate the gate insulation layer 131 . In one embodiment, impurity ions are implanted at a dose of 10 13 ions/cm 2 and higher, preferably, about 2×10 13 to 5×10 13 ions/cm 2 . The second photoresist pattern 52 is then removed.
[0033] Referring to FIG. 10, a third photoresist pattern 53 is formed to expose a portion of the trench bottom. The exposed gate insulation layer 131 is then etched. After removing the third photoresist pattern 53 , the exposed substrate is thermally oxidized to form a thin insulation layer that is suitable for a tunneling. In this case, the tunneling insulation layer may be an oxide nitride layer instead of an oxide layer. The second photoresist pattern 52 for an ion implantation mask (shown in FIG. 9) may be used as the third photoresist pattern during the process of FIG. 10. However, during the process of FIG. 9, a line-type photoresist pattern may be formed to stretch over the active region and the device isolation layer. Also, during the process of FIG. 9, the photoresist pattern may be formed wider than the region including the tunneling insulation layer. For this reason, the second and third photoresist patterns are typically formed separately.
[0034] Referring to FIG. 11, a fourth photoresist pattern 54 is formed to expose a sidewall of the trench and to cover the upper side of the substrate. An N-type region 143 is formed in the substrate of the trench sidewall adjacent to a bit line contact by an oblique ion implantation. The oblique ion implantation enables impurity ions to be implanted into lower corners of the trench. Preferably, the photoresist pattern has a thickness of less than 1 mm. The N-type region 143 is formed at a higher energy and at a lower or similar dose as compared with an implantation into a lightly doped region of a typical LLD-type transistor. At this time, impurity ions are implanted with 60 to 90 KeV and a dose of 10 13 ion/cm 2 . Accordingly, the N-type region 143 of the trench sidewall is formed at a lower dose as compared with a lightly doped region of a typical transistor.
[0035] The fourth photoresist pattern 54 may be formed by using it as it is or processing the third photoresist pattern 53 of FIG. 10. For example, the third photoresist pattern 53 of FIG. 10 can be isotropically ashed and a surface thereof recessed to form the fourth photoresist pattern 54 of FIG. 11. In this case, after implanting impurity ions as shown in FIG. 11, the fourth photoresist pattern 54 is removed. Thereafter, the substrate is thermally oxidized to form a tunneling insulation layer 123 .
[0036] Referring to FIG. 12, the fourth photoresist pattern is removed from the substrate. Thereafter, a first polysilicon layer 119 ′ and a dielectric layer 127 ′ are sequentially stacked on the substrate where a gate insulation layer 131 including a tunneling insulation layer 123 is formed. The dielectric layer is generally an oxide-nitride-oxide (ONO) layer or a combination of a silicon nitride layer and a silicon oxide layer. When the polysilicon layer 119 ′ and the dielectric layer 127 ′ are stacked on the substrate, a thickness of the stacked layers should be adjusted to remain a predetermined space in an inside of the trench.
[0037] Referring to FIG. 13, a fifth photoresist pattern 55 is formed to cover at least a trench region. The dielectric layer and the first polysilicon layer are etched by using the fifth photoresist pattern 55 as an etch mask. As a result, the floating gate 119 is formed and covered with a dielectric layer pattern 127 .
[0038] Referring to FIG. 14, the fifth photoresist pattern is removed by ashing and wet stripping. A sidewall of the floating gate 119 is annealed to cure etching damage. Also, the exposed sidewall of the floating gate is thermally oxidized to form a sidewall oxide layer 118 . A second polysilicon layer 115 ′ is stacked on an entire surface of the substrate. A sixth photoresist pattern 56 corresponding to a sensing line and a word line is formed on the second polysilicon layer 115 ′.
[0039] Referring to FIG. 15, the second polysilicon layer is etched to form a sensing line 115 and a word line 113 . The sensing line 115 may be formed wider or narrower than a floating gate 119 , though the sensing line 115 must be wide enough to fill the remaining space of the trench. At this time, although not shown in the drawings, a patterning process is preferably performed together to form a gate electrode of an NMOS transistor in a peripheral circuit region.
[0040] After removing the sixth photoresist pattern 56 , a seventh photoresist pattern 57 is formed. The seventh photoresist pattern exposes high-voltage regions adjacent to the word line 113 in a cell memory active region. Although a peripheral region of the memory device is not shown, the seventh photoresist pattern 57 is typically formed in consideration of formation of a high-voltage NMOS transistor in a peripheral region. N-type impurity ions are implanted into the substrate by using the seventh photoresist pattern 57 as an ion implantation mask to form lightly doped N-type regions 135 and 143 a . N-type impurity ions are implanted into the active region at a low dose of about 10 13 ions/cm 2 and at a high energy of about 60 KeV so as to obtain a required breakdown voltage.
[0041] Considering the whole memory device, P-type impurity ions may be implanted to form a high-voltage PMOS transistor in a peripheral circuit region. In this case, P-type impurity ions are implanted using a separate photoresist pattern like the foregoing N-type impurity ion implantation. Generally, after forming the lightly doped N-type regions 135 and 143 a , the seventh photoresist pattern 57 is removed. Thermal diffusion is then performed to achieve a predetermined junction depth and a predetermined concentration. At this time, sidewalls of the gate line may be cured by the thermal diffusion.
[0042] Referring to FIG. 16, after the seventh photoresist pattern is removed, an eighth photoresist pattern 58 is formed to expose a source region of the sensing transistor. N-type impurity ions are then implanted at a dose of about 3×10 13 ions/cm 2 and at a low energy of about 20 KeV to form a lightly doped region corresponding to a source region 137 . Considering the whole memory device, low-concentration impurity ions may be implanted into a peripheral circuit region to form an NMOS transistor. Also, P-type impurity ions may be implanted using a separate photoresist pattern like the foregoing N-type impurity ion implantation. The eighth photoresist pattern 58 is then removed.
[0043] Referring to FIG. 17, an insulation layer such as a silicon nitride layer is stacked on the lightly doped substrate. Continuously, the insulation layer is etched using an anisotropic etch process to form a spacer 145 on each sidewall of the floating gate 119 , the sensing line 115 , the word line 113 and peripheral gate pattern (not shown). A ninth photoresist pattern 59 is then formed on the substrate. The ninth photoresist pattern 59 covers the sensing line 115 , the word line 113 , and the substrate therebetween. High-concentration impurity ions are implanted into the active region using the ninth photoresist pattern 59 as an ion implantation mask. This results in formation of a heavily doped region such as a common source line 139 and a contact region 141 . The high-concentration impurity ions are implanted with a dose of about 10 15 ions/cm 2 and about 60 to 90 KeV. Impurity ions may be implanted into a heavily doped region of the NMOS transistor source/drain along with the foregoing ion implantation. P-type impurity ions may be implanted into a PMOS transistor using a separate photoresist pattern like the foregoing N-type impurity ion implantation.
[0044] In the subsequent processes, an interlayer insulation layer is stacked; a contact hole is formed on a contact region; and a bit line contact and a bit line are formed. In some cases, impurity ions may be implanted into the contact region during a high-concentration impurity ion implantation. That is, impurity ions may be implanted into the contact region after forming a contact hole in the interlayer insulation layer.
[0045] According to the present invention, a floating gate is formed at a trench to increase an opposite area to a control gate. As a result, a coupling ratio of a sensing transistor in a cell memory may be increased. Furthermore, data can be erased and programmed in the memory cell with reliability at a comparatively low voltage.
[0046] While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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An EEPROM memory cell and a method of forming the same are provided. A portion of a floating gate is formed on walls of a trench formed on the substrate. An inside of the trench is filled with a gate electrode layer constituting a sensing line. This leads to increases in opposite areas of a floating gate and a control gate of a sensing transistor, and a decrease in an area of the floating gate in the substrate. The method of forming an EEPROM memory cell comprises forming a trench in an active area in which a sensing transistor of the substrate will be formed; forming a gate insulation layer including a tunneling insulation layer on an entire surface of the substrate including an inside of the trench; conformally forming a first conductive layer covering the inside of the trench after forming the gate insulation layer; conformally forming a dielectric layer on the first conductive layer; forming a floating gate by patterning the first conductive layer; and stacking and patterning a second conductive layer on the dielectric layer to form a word line and a sensing line.
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TECHNICAL FIELD
The present invention relates in general to an improved safety valve and a method of using it to control the flow of a fluid. The invention more particularly relates to a safety shut off valve which provides vibration and excess flow protection and which automatically reset following a seismic disturbance in the absence of any downstream fluid leakage according to a novel automatic resetting method.
BACKGROUND ART
There have been many different types and kinds of valves used to facilitate the controlling of fluid flow in the event of unwanted and undesired downstream leakage. For example reference may be made to the following U.S. Pat. Nos.: 2,215,044; 2,569,316; 2,585,316; 2,949,931; 3,747,616; 4,212,313; 4,245,814; 4,382,449; 4,485,832; 4,565,208; 4,715,394; 4,785,842; 4,844,113; 4,874,012; 5,010,916; 5,052,429; 5,119,841; 5,203,365 5,409,031 and 5,603,345.
Seismic responsive shut off valves have been encouraged in certain parts of the United States and other parts of the world for fluid delivery systems in both residential and commercial settings. In this regard, the function of such a safety shut off valve is to interrupt the flow of gas, generally at the meter, whenever a sizable perturbation in stability occurs to facilitate the prevention of explosions and fires caused by gas leakage through broken or damaged downstream pipes.
The typical seismic responsive shut off valve however, is only sensitive to seismic shock wave and other shock forces for fluid shut off purposes and is not otherwise concerned with sensing excess flow for providing excess flow protection. Flow protection valves on the other hand, are only sensitive to excess flow conditions and are not otherwise concerned with shutting off gas flow during sizable perturbations in stability.
Therefore it would be highly desirable to have a new and improved safety shut off valve which provides shut off capabilities for both seismic vibrations of a predetermined magnitude as well as excess flow protection.
A typical shut off valve responsive to seismic movements generally includes a ball or plate that falls into a fluid communication path during a seismic occurrence to block the fluid passageway. The ball or plate must thereafter must be manually reset to once again restore the normal fluid flow.
While such a valve may shut off the flow of fluids in the event of a large or sizable perturbation in stability, such a valve has not proven to be entirely satisfactory. In this regard, before the value can be reset, there must be an inspection of the fluid delivery system downstream of the value for possible damage. The valve therefore must not be reset until an assessment of downstream pipe breakage and leakage has been completed and repaired by a trained technician. Then, and only then, may the valve be manually reset. Therefore, even if there is no pipe damage or leakage, a skilled technician must nevertheless be called out to reset the valve. Such activities overtly increase the responsibility of the fluid supplier and can place an extraordinary demand on the resources of the supplier to restore services after the occurrence of an earthquake of any sufficient magnitude to cause a valve shut off condition.
Therefore it would be highly desirable to have a new and improved safety shut off valve that interrupts fluid flow during sizable perturbations in stability and that automatically resets to restore normal fluid flow without the need of a trained and qualified technician performing an assessment to determine whether there is a downstream broken or leaking pipe. Such a valve should also be easy to install and be relative inexpensive to manufacture.
SUMMARY OF INVENTION
Therefore the principal object of the present invention is to provide a new and improved safety shut off valve which provides shut off capabilities for both seismic vibrations of a predetermined magnitude as well as excess flow protection.
Another object of the present invention is to provide such a new and improved safety shut off valve that interrupts fluid flow during sizable perturbations in stability and that automatically resets to restore normal fluid flow without the need of an assessment by a trained and qualified technician for determining whether there is a downstream broken or leaking pipe.
Another object of the present invention is to provide such a new and improved earthquake and shut off valve that is easy to install and that is relatively inexpensive to manufacture.
Briefly, the above and further objects of the present invention are realized by providing a new and improved safety shut off valve which automatically shuts off in response to seismic or other shock wave forces a predetermined magnitude and thereafter automatically reset when there is no discernible excess gas flow due a downstream broken or leaking pipe.
The earthquake shut off valve generally includes a housing adapted to be fixed in line within an existing gas delivery system having a mass spring system mounted therein for translating lateral seismic and other shock forces exerted against the housing to an axially movable magnet for decoupling a valve member plate attracted thereto allowing it to block the downstream fluid communication path. A small bypass flow permits the valve member plate to be automatically reset in engagement with the magnet with the atmospheric pressure across the plate is equalized.
BRIEF DESCRIPTION OF DRAWINGS
The above-mentioned and other objects and features of this invention and the manner of attaining them will become apparent, and the invention itself will be best understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a pictorial view of a safety shut off valve assembly which is constructed in accordance with the present invention;
FIG. 2 is an enlarged sectional elevational view of the valve assembly of FIG. 1, taken substantially on line 2--2 thereof;
FIG. 3 is a sectional view of the valve assembly of FIG. 2, taken substantially on line 3--3 thereof;
FIG. 4 is a fragmentary sectional elevational view of another safety shut off valve assembly which is constructed in accordance with the present invention; and
FIG. 5 is a fragmentary sectional elevational view of another safety shut off valve assembly which is constructed in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and more particularly to FIG. 1 thereof, there is shown a safety shut off valve assembly 10 which is constructed in accordance with the present invention, The shut off valve assembly 10 is adapted to be mounted in line in a fluid delivery system 11 in an upright or vertical orientation for substantially preventing the flow of fluid downstream therefrom when the assembly 10 is subjected to seismic or vibrational shockwave forces of a predetermined magnitude. The shut off valve assembly 10 upon the subsidence of the seismic forces automatically resets itself to restore fluid flow in accordance with the method of the present invention.
The shut off valve assembly 10 generally comprises an elongated hollow housing member 12 and a shut off valve arrangement 14 which is disposed within the hollow interior of the housing member 12. The housing 12 is hollow throughout its entire length having an interior wall 13 that is generally cylindrical shape for coupling the valve assembly 10 in line with a conventional threaded pipeline, such as a gas pipeline 17. Both ends of the housing 12, are internally threaded at about 15 and 16 respectively to permit the shut off valve assembly 10 to be easily installed in an upright manner at any convenient location in the fluid delivery system. In this regard, the assembly 10 is installed in the fluid delivery system 11 in the same convenient manner as a conventional pipe coupling.
Although in the preferred embodiment of the present invention the housing 12 is described as having internal threads, those skilled in the art will understand that external threads or a combination of internal and external threads may be employed.
The housing member 12 defines an elongated fluid communication path indicated generally at 18 that extends between an inlet 20 that receives upstream fluids from the fluid delivery system 11 and an outlet 22 that discharges the received fluids downstream into the fluid delivery system 11.
In order strengthen the housing member 12 against lateral and omni directional forces created by a seismic disturbance, the interior of the housing is divided into a set of chambers by an upstream web member 24 and a downstream web member 26. The upstream web member 24 is integrally connected to the interior wall 13 of the housing 12 and has an annular shape that reinforces the interior wall 13 of the housing 12. The upstream web member 24 is spaced from the inlet 20 a sufficient distance to define an inlet or spring receiving chamber 28 that is in fluid communication with the upstream fluids being delivery by the fluid delivery system 11.
The downstream web member 26, is spaced from the upstream web member 24 and the outlet 22 and helps to define an interior or magnet chamber 30 and an outlet or valve seat chamber 32, each being in fluid communication with the inlet chamber 28. The downstream web member 26 is annular shaped and integrally connected to interior wall 13 of the housing member 12 for wall reinforcement purposes.
The shut off valve arrangement 14 includes two basic components a translation assembly 34 and a magnetically actuated valve assembly 36. The translation assembly 34 responds to seismic induced lateral and omni directional vibrational forces by generating an oscillatory force along a rectilinear path of travel 38 that extends along the longitudinal axis (L) of the housing member 12, which in turn, causes a magnet 37 to move in an oscillatory manner away from and toward the downstream web member 26. In this regard, whenever the seismic force exceeds a predetermined magnitude, the translation assembly 34 will cause the magnet 37 to move a sufficient distance away from the downstream web member 26 to enable the valve assembly 36 to be actuated from an open position to a close position as best seen in FIG. 2, to effect blockage of the fluid communication path 18.
Following the seismic disturbance, the valve assembly 36 responds to the attracting forces generated by the magnetic flux of the magnet 37 and automatically reset to its normally open position so long as downstream pressure in the fluid delivery system is substantially the same as the upstream pressure in the fluid delivery system. If there is a pressure differential between the upstream pressure and the downstream pressure, the valve assembly 36 will not reset but instead will remain in a closed position until the pressure differential is equalized. Once the pressure is equalized, the valve assembly 36 automatically reset to the normally open position.
In operation, whenever a lateral force is exerted against the shut off valve assembly 10 by a seismic disturbance, the seismic force is coupled to the translation assembly 34 and the valve assembly 36 via the housing member 12. The translation assembly 34 responds to the seismic force by converting the lateral displacement of the housing member 12 into an oscillatory force that moves along the rectilinear path 38 coextending in part with the longitudinal axis (L) of the housing member 12. The vertically directed force generated by the translation assembly 34 is coupled to the magnet 37, which in turn, moves away from and toward the downstream web member 26. As the natural frequency of the translation assembly 34 and seismic disturbance move toward synchronization, the vertical displacement of the magnet 36 from the downstream web member 26 becomes greater and greater until the distance from the magnet 37 and the downstream web member 26 is sufficiently great to enable the valve assembly 36 to actuate from its normally open position to the closed position as best seen in FIG. 2.
Once the seismic disturbance has subsided, the translation assembly 34 causes the magnet 37 to be moved into engagement with the downstream web member 26 so that the magnet 37 can exert a sufficient attracting force against the valve assembly 36 to causes it to move from its closed position to its normally open position in the absence of any pressure differential between the fluid delivery system downstream of the valve assembly 10 and the fluid delivery system upstream of the valve assembly 10. In the event the seismic disturbance has cause pipe breakage downstream or in the event there is leak of sufficient volume to create a pressure differential, the resulting force exerted by the pressure differential across the valve assembly 36 via a small by-pass hole 60 is sufficient to prevent the valve assembly 36 to be restored to its normally open position. The valve assembly 36 will therefore remain in the closed position until the upstream and downstream pressure have been equalized relative to the valve assembly 10.
From the foregoing it should be understood by those skilled in the art that the safety shut off valve assembly 10 also functions as an excess flow check valve whenever a pressure differential of sufficient magnitude to overcome the attracting force of the magnet 37 relative to the valve assembly 36 established. More specifically, whenever the fluid drag force on the valve assembly 36 due to a flow rate or pressure differential above a predetermined limit overcomes the attracting force of the magnet 37 on the valve assembly 36, the valve assembly 36 moves to its closed position to shut off fluid flow and remains in the closed position until pressure differential upstream and downstream is equalized.
Considering now the upstream web member 24 in greater detail with reference to FIG. 2, the upstream web member 24 includes a plurality of holes or apertures, such as an opening 62 and an opening 64, that allows fluid to freely flow from the inlet chamber 28 into the interior chamber 30. A large rod receiving hole 25 is centrally disposed with the upstream web member 24 for facilitating supporting of the magnet 37 for rectilinear movement as will be explained hereinafter in greater detail.
Considering now the translation assembly 34 in greater detail with reference to FIG. 2, the translation assembly 34 generally includes a spring 40 which is supported from below by the upstream web member 24 within the upstream inlet chamber 24. The spring 40 is coupled to a mass 42 by an upper support rod 44 that is attached at its proximal end to a spring plate 41 and at its distal end to a top portion 43 of the mass 42. The support rod 44 extends through the rod receiving hole 25 a sufficient distance to position the mass 42 at about an equal distance from the upstream web member 24 and the downstream web member 26 so the mass 42 can freely oscillate within the interior chamber 30. In order to facilitate unobstructed substantially friction free movement of the rod 44 relative to the hole 25, a bearing sleeve member having a set of bearings (not shown) is mounted within the hole 25.
As best seen in FIG. 2, the magnet 37 is coupled to the mass 42 by a lower support rod 46 that extends along the longitudinal axis (L) of the housing 12 between a bottom portion 45 of the mass 42 and the magnet 37. When at rest, the overall length of the upper support rod 44, the mass 42 and the lower support rod 46 is sufficient to position a bottom portion 48 of the magnet 37 adjacent to the downstream web member 26 so that its magnetic flux travels through the web plate member 26 to exert a sufficient restraining or attracting force against the valve assembly 36 to hold it in its normally open position.
In order to control the rectilinear path of travel followed by the mass 42 and the magnet 37 during lateral movement of the shut off valve assembly 10, the magnet 37 is enclosed within the interior of an elongated housing 49 that is centrally disposed on the downstream web member 26 within the interior chamber 30. The housing 49 is generally cylindrical in shape and is dimensioned to receive therein for relatively friction free rectilinear movement the magnet 37. The housing 49 is attached removable to the downstream web member 26 by conventional means not shown.
The top portion of the housing 49 is threaded for receiving therein a threaded stop 50. The stop 50 form a barrier at the top end of the housing 49 that limits the upward path of travel followed by the magnet 37. In this regard, when the magnet 37 moves under the oscillatory force of the spring 40 and mass 42 it travels along a rectilinear path of travel 52 within the interior of the housing 48. The limits of the path of travel 52 include an upper limit defined by the stop member 50 and a lower limit defined by the downstream web member 26. The overall length of the path of travel 52 is sufficient to cause the valve assembly 36 to move to its closed position when the magnet 37 is disposed at the stop member 50, and to its open position when the magnet 37 is disposed at the downstream web member 26.
Considering now the magnetically actuated valve assembly 36 in greater detail with reference to FIG. 2, the valve assembly 36 generally includes a valve member or annular plate 54 and a valve seat 56 which are both disposed within the outlet chamber 32. The valve seat 56 is an annular shaped wall that projects inwardly a distance (d) from the interior wall 13 of the outlet chamber 32. The valve seat 56 is spaced apart from the downstream web member 26 by a distance (D), where the distance (D) is not a sufficient distance to prevent the valve member 54 from being attracted to the downstream web member 26 when the magnet 37 is disposed adjacent thereto and the valve member 54 is disposed on the seat 56. The distance (D) is however, a sufficient distance to prevent the valve member 54 from being attracted to downstream web member 26 when the magnet 37 is disposed adjacent thereto and the valve member 54 is disposed on the seat 56 and there is a pressure differential of () pounds per square inch applied across the valve member 54. In this regard, when there is the absence of a pressure differential of (P) pounds per square inch applied across the valve member 54, the valve member 54 will be attracted back to its normally closed position when the magnet 37 is disposed adjacent to the downstream web member 26.
From the foregoing those skilled in the art will appreciate that the shut off valve assembly 10 has a dual function. In a first mode of operation, the assembly 10 functions as a fluid shut off valve that prevents the supply of fluid downstream of the assembly 10 whenever the assembly 10 is subjected to a seismic force of at least a predetermined magnitude that causes the magnet 37 to be moved under control of the spring 40 and mass 42 into engagement with the stop 50. In this first mode of operation the shut off valve assembly 10 automatically resets itself when the magnet 37 comes to rest at the downstream web member 26 and there is no downstream leakage to cause a pressure differential of (P) pounds per square inch to be exerted across the valve member 54. Thus whenever such a downstream leak is repaired the shut off valve assembly 10 will automatically rest itself.
In the second mode of operation, whenever a downstream leak or break occurs to cause a pressure differential of at least (P) pounds per square inch to be applied across the valve member 54, the valve member 54 will move to the valve seat 56 and be held their until the pressure differential is eliminated or at least reduce to some pressure below (P) pounds per square inch. Again when the pressure across the valve member 54 is equalized, the magnet 37 will cause the valve member 54 to be moved to its open position adjacent the downstream web member 26.
Considering now the downstream web member 26 in greater detail with reference to FIGS. 2 and 3, the downstream web member 26 is generally circular in shape having a set of equally spaced apart radially inwardly projections 80-83 for defining a set of openings, such as the openings 70-73 that are inwardly spaced from the outer periphery of the web member 26.
The web member 26 is supported from belw by a hollow cylindrically shaped spacer 88 having a height (H) and a diameter (W). The spacer 88 is received in the interior of the housing 12 ain a friction tight fit and is supported from below by a valve set base meber having the upwardly projecting valve seat 56 integrally connected thereo at the interior periphery thereof.
The height (H) of the spacer 88 is selected form spacing the web 26 from the valve seat 56 by a predetermined distance X. In this regard, spacers pf doffetremt jeogts H may be utilized to calibrate the distance X to accomodate magnets having different magnetic strengths for different environmental applications. Thus for example the assembly 10 may be employed not only for earthquake conditions but also for hurricane and tornado conditions. The diameter (W) of the spacer is selected to permit the valve member 54 to slide in a relative friction free manner within the interior chamber 32 defined by the spacer 88.
In order to secur the web 26 within the housing 12, the web 26 is ahesively bonded to the upstream end of the spacer 88 by means not shown. Although the spacer 88 is described as being secured in the housing 12 in a friction tight fit, it is contemplated that a set screw (not shown) passing through the wall of the housing 12 can also be employed to secure the spacer 88 in the interior of the housing 12.
Considering now the valve member 54 in greater detail with reference to FIG. 2, the valve member 54 is a flat annular or circular shaped plate which is dimensioned for relative friction free rectilinear movement within the outlet chamber 32. The valve member 54 has an overall diameter that is substantially greater than the diameter of the annular opening formed by the valve seat 56. In this regard the valve seat 56 functions as a stop to prevent the valve member 54 from passing downstream beyond the valve seat 56.
Referring now to the drawings and more particularly to FIG. 4, there is shown another shut off valve assembly 100 which is constructed in accordance to the present invention. The assembly 100 is substantially similar to the shut off valve assembly 10 except as will be explained hereinafter in greater detail. The shut off valve assembly 100 generally includes a hollow housing member 112 having disposed on its interior an upstream web member 124, and a downstream web member 126 that cooperate with one another to help define a three chamber construction including an upstream or inlet chamber 128, an interior chamber 130 and a downstream or outlet chamber 132. A translation assembly 134 is disposed partially within the upstream and interior chambers 128 and 130 respectively and a magnetically actuated valve assembly 136 is disposed within the downstream chamber 132.
The translation assembly 134 is substantially similar to the translation assembly 34 and includes a mass 142 having a top portion 143 connected to the distal end of an elongated rod 144. The translation assembly 134 further includes another elongated rod 146 which is attached to the mass 142 at its proximal end and which is attached at its distal end to a magnet 137 disposed within an interior housing 149. The housing 149 is integrally connected to the downstream web member 126 and extends perpendicularly upwardly therefrom a sufficient distance D1 to support from below the mass 142. In this regard, a top lip portion 150 of the housing 149 functions as an interior stop that limits the downward path of travel followed by the mass 142 as it travels along a rectilinear path of travel 152 within the interior chamber 130. In order limit the upward path of travel followed by the mass 142, the upstream web member 124 includes a centrally disposed downwardly depending hollow stop member 158 that is disposed in the path of travel 152 followed by the mass 142.
The safety shut off valve assembly 100 operates in substantially the same manner as the safety shut off valve assembly 10 except that the rectilinear path of travel followed by the magnet 137 is limited by the lip 150 and the stop 158 that determine the path of travel limits followed by the mass 142.
Referring now to the drawings and more particularly to FIG. 5, there is shown a safety shut off valve assembly 200 which is constructed in accordance with the present invention. The shut off valve assembly 200 is substantially similar to the valve assembly 10 except as will be explained hereinafter in greater detail. The shut off valve assembly 200 generally includes a hollow housing member 212 having disposed on its interior a downstream web member 226 that helps define a three chamber construction that includes an interior chamber 230 and an outlet chamber 232. A translation assembly 234 is partially disposed within the interior chamber 230 and a magnetically actuated valve assembly 236 is disposed within the downstream chamber 232. The translation assembly 234 includes a magnet 237. The valve assembly 236 is substantially similar to the valve assembly 36 and will not be described hereinafter in greater detail.
The translation assembly 234 is similar to the translation assembly 34 except that it does not include a separate mass, such as the mass 42. Instead as will be explained hereinafter in greater detail, the mass of the translation assembly 234 is confined to the magnet 237.
Considering the translation assembly 234 in greater detail with reference to FIG. 5, the translation assembly 234 includes a spring 240 and a single elongated rod 244 that is coupled at its proximal end to the spring 240 and attached at its distal end to the magnet 237. An interior housing 249 directs the rectilinear path of travel 252 followed by the magnet 237. In order to cause the translation assembly 234 to oscillate in response to a seismic force of a predetermined magnitude, the magnet 237 has a weight of about K kilograms that is substantially equal to the weight of the magnet 37, the mass 42, and the elongated rods 44 and 46 in order to effect substantially the same oscillatory response as exhibited by the translation assembly 34 in response to a seismic force of a predetermined magnitude.
While particular embodiments of the present invention have been disclosed, it is to be understood that various different modifications are possible and are contemplated with the true spirit and scope of the appended claims.
For example different types of materials may be employed for construction of the valve assembly, and such materials may include plastic and metallic materials. It is also contemplated that the valve assembly 10 can be encapsulated within a separate housing in order to insert the assembly within the interior of a existing fluid delivery system.
There is no intention, therefore, of limitations to the exact abstract or disclosure herein presented.
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An safety shut off valve automatically shuts off in response to seismic or other shock wave forces of a predetermined magnitude and thereafter automatically reset when there is no discernible excess gas flow due a downstream broken or leaking pipe. The shut off valve generally includes a housing having a mass spring system mounted therein for translating lateral seismic and other shock forces exerted against the housing to an axially movable magnet for decoupling a valve member plate attracted thereto allowing it to block the downstream fluid communication path. A small bypass flow permits the valve member plate to be automatically reset in engagement with the magnet when the atmospheric pressure upstream of the plate is substantially equal to the atmospheric pressure downstream of the plate.
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BACKGROUND OF THE INVENTION
The present invention relates, in general, to subsea well apparatus and is directed specifically to subsea well apparatus such that in only one trip between the vessel or platform on the water surface and the subsea well, a casing string is run into the well bore and cemented in place, a wear bushing is positioned within the well bore for protecting the surrounding wellhead during subsequent drilling operations, and the annular seal region between a casing hanger body and the surrounding wellhead bore is sealed and tested.
Still more specifically, this invention improves such apparatus by providing in such apparatus means by which the running tool can be released rapidly prior to moving the seal into the annular seal region and means by which the wear bushing is positioned in its final operating position when the apparatus is initially landed in the well bore. Also included in the means for rapid release of the running tool is means for releasing the drive elements of the running tool upon application of low torque and a safety feature to prevent accidental release of the running tool for the casing hanger.
In the drilling of oil and gas wells at an underwater location, a casing string is run into a well bore, and supported by a casing hanger (also referred to as hanger body) resting on complementary seats within a surrounding wellhead. After the casing string is cemented in place, a suitable seal assembly, referred to as a packoff assembly, is actuated (energized) to packoff (seal) the annular seal region between the exterior of the casing hanger and the surrounding wellhead for later drilling operations to take place within the wellhead. Energizing the packoff (seal) is also referred to as setting the packoff. Apparatus for such operations is illustrated in a number of U.S. patents, such as, for example, U.S. Pat. Nos. 3,313,030, 3,468,558, 3,468,559, 3,489,436, 3,492,026, 3,797,864 and 3,871,449. These patents not only show examples of casing hangers (hanger bodies), axially deformable elastomeric packing seals (packoff assemblies), and seat protectors (now called wear bushings depending on their function, although in these patents the terms were used interchangeably), but they also show the seat protectors being lowered into position in one trip of the running tool between the vessel or platform and the well. However, none of the patents show a seat protector (wear bushing) positioned in its final position upon landing of the running tool in the well bore. A lowering of the seat protector (wear bushing) into place was required later. Reference is also made to the U.S. patent application of Goris and Pettit, Ser. No. 719,383, filed Apr. 2, 1985 now U.S. Pat. No. 4,611,663 entitled "Casing Hanger and Running Apparatus", which discloses apparatus in which seating the casing hanger within the wellhead, cementing the casing hanger in place, packing off the seal region and pressure testing off the seal for leakage is accomplished in one trip between the vessel or platform and the well. However, no wear bushing is disclosed in this referenced application.
SUMMARY OF THE INVENTION
This invention includes a running tool comprising a stem with a plug, a running nut, a wedge, a cam ring, and a bottom nut which together releasably connect and support a casing hanger, wear bushing, and packoff assembly thereon. The bottom nut threaded on the stem supports the cam ring which is externally profiled to engage complementary profiles on the casing hanger and is wedged into engagement therewith by axial movement of the running nut, due to rotation of the stem, urging the wedge to expand the cam ring. A packoff assembly is threaded on external threads on the top of the casing hanger and is keyed to the wear bushing for rotational movement therewith. The wear bushing is likewise keyed to the plug so that rotation of the plug rotates the wear bushing and the packoff assembly.
The casing hanger, wear bushing and packoff assembly are lowered together into position within the wellhead on the running tool. In its initial landed position, the wear bushing is positioned without further movement being required and a flowby path is available during the circulating and cementing operations. After cementing has been completed, the running tool is released by rotation of the stem which raises the running nut, disengages the wedge from the expanded cam ring and allows the cam ring to disengage the casing hanger. The running nut is splined to the stem and is provided with a thread having a significantly high angle thread lead (helix) of 10° to 15° for rapid axial movement. A dead band area between the wedge and running nut allows considerable amount of axial movement of the running nut before disengagement of the wedge from the cam ring as a safety feature against accidental disengagement of the casing hanger and running tool. Continued rotation raises the running nut to its uppermost position where it becomes a driving element to rotate the plug and wear bushing to thread the packoff assembly downwardly into the annular seal region between the exterior of the casing hanger and the surrounding wellhead and to energize the packoff seal portion thereof to seal the annular seal region.
It will be apparent to those skilled in the art after a review of the drawings and the Detailed Description that the arrangement of this invention provides a means by which the diameter of the inner bore (ID) of the wear bushing and the inner bore (ID) of the casing hanger are substantially the same so that wear of one or the other will not differ significantly during subsequent operations in the well and that the high angle thread on the running nut is effectively a releasable thread that allows high torque to be applied to the running nut in its driving position, but also allows the running nut be be backed off from its driving position with much less torque being applied to facilitate preparing the running tool for reuse.
It will also become apparent that with this invention the running tool is capable of being released if desired, even though the packoff assembly has not been placed in proper sealing position, for whatever reason, to allow the running tool to be retrieved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view, in section, illustrating the running tool, casing hanger, wear bushing and packoff assembly landed within a well housing,
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1,
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 1,
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 1,
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 1,
FIG. 6 is an enlarged view of the detail of the latching mechanism and key in the wear bushing in the area surrounding by the arrow 6 in FIG. 1,
FIG. 7 is an enlarge detail of part of the packoff assembly in the area encircled by arrow 7 in FIG. 1,
FIG. 8 is an elevational view in section illustrating the packoff assembly having landed and the casing hanger being free of the running tool,
FIG. 9 is an enlarged detailed view similar to FIG. 6 showing the latching mechanism having latched the packoff drive ring to the wear bushing in the area encircled by the arrow 9 of FIG. 8, and
FIG. 10 is an enlargement of the area encircled by arrow 10 in FIG. 8 and showing the packoff assembly sealed in the seal annulus.
DETAILED DESCRIPTION
In FIG. 1 of the drawings, the invention is depicted already landed in the wellhead housing 10 with a casing hanger 12 shown supported on a suitable outwardly facing seat or shoulder (not shown) in the bore of the wellhead housing. The casing hanger 12, wear bushing 14 and packoff assembly 16 were assembled (made up) on a running tool 20 while on the vessel or platform and were lowered from the vessel or platform to the wellhead housing 10 by having a stem 22 connected by a tapered thread connection 24 to the lower one of a string of tubing, such as drill pipe. As shown, the wear bushing 14 is nested in the casing hanger 12 and the packoff drive nut 26 of the packoff assembly 16 is threaded on, and thus supported by, the casing hanger 12. In the position shown, circulating and cementing operations can be conducted in the usual manner. After completion of the cementing operation, the annular seal space 28, between the cylindrical inner wall or bore of the wellhead housing 10 and the opposing cylindrical wall of the casing hanger 12, is sealed by the packoff assembly 16.
The running tool 20 comprises the following components: the stem 22 with a running nut 30, a wedge 32, a cam ring 34 and a bottom nut 36 at the lower end thereof, a plug 40 and stabilizing fins 42 near the upper end of the stem 22. The running tool 20 with its attendant components are retrievable as will be understood from the description hereinafter.
The depicted casing hanger 12 is typical and comprises a main body section 44 provided with a cylindrical inner bore and circulating passages 46 and a packoff actuating shoulder 50. External threads 52 are located near the upper thin end section 54 of the casing hanger and shown in threaded engagement with internal threads 56 on the packoff nut 26. The threads 52 are right-handed so that right hand rotation of the wear bushing will lower the packoff nut toward the seal annulus 28.
The lower end of the running tool stem 20 supports the bottom nut 36 on external threads 60 on the stem. A set screw 62 holds the bottom nut 36 in place after the latter is threaded on the stem 20. This bottom nut 36 supports the cam ring 34 which is provided with an external latching profile 64 for engaging a complimentary internal latching profile 66 formed on the inner bore of the casing hanger. The cam ring 34 is a split ring and is biased out of engagement with the casing hanger latching profile, but is forced radially outwardly into engagement with the casing hanger profile by the wedge 32. This cam ring 34, when in engagement with the casing hanger profile 66, supports the casing hanger 12 on the running tool stem 22 together with the wear bushing 14 and packoff assembly 16. Retraction of the cam ring 34, on the other hand, not only permits initial assembly of the casing hanger and its supported equipment onto the running tool stem 22, but also allows disengagement of the running tool 20 for retrieval at the appropriate time. The outer diameters of the bottom nut and the cam ring in its collapsed position, respectively, are less than the internal bore of the wear bushing so that the bottom nut and cam ring are retrievable along with the rest of the running tool.
The wedge 32 is the lower enlarged end of an integral sleeve 70 which rotates freely on the outer periphery of the stem 22 and is moved in and out of engagement with the cam ring 34, i.e., moved axially of the stem 22, by the running nut 30. The running nut 30 is also a elongated sleeve with its lower end telescoped over the sleeve 70 of the wedge 32 and is provided with a radially inwardly extending rim 72 which is engagable with a radially outwardly extending rim 74 on top of the sleeve 70. The top portion 76 of the running nut 30 is keyed into an axial keyslot 80 formed on the outer periphery of the stem 22 so that rotation of the stem 22 will also rotate the running nut 30. FIG. 1 shows only one key slot 80, but there are several, as shown in FIG. 4. The external surface of the top portion 76 of the running nut 30 is provided with external threads 82 which threadably engage internal threads 84 of the plug 40.
The plug 40 is cylindrical with an inner bore spaced from the periphery of the stem 22 a distance sufficient to accommodate the top portion 76 of the running nut 30. During assembly of the casing hanger 12, wear bushing 14 and packoff assembly 16 on the running tool, this plug 40 is held stationary with respect to the stem 22 so that rotation of the stem 22 will thread the running nut 30 axially of the stem 22. Thus, rotation of the stem 22 to the left, i.e., counter clockwise as viewed from the vessel or platform, will move the running nut 30 downwardly so that the end 86 of the running nut 30 will engage a shoulder 88 between the wedge and sleeve 70 urging the cam ring 34 and its profile 64 into engagement with the profile 66 on the casing hanger 12. This is the position of the components in FIG. 1. The plug is provided with a position indicator in the form of a stick 90 located in a longitudinal throughbore 92. The stick engages the running nut 30 and provides an indication that the cam ring 34 is positioned correctly in the casing hanger profile 66. When the stick is not in use, it may be inserted in a blind bore 94 in the plug and the through bore 92 is suitably sealed as by a cap (not shown) to prevent a leakage path through the through bore. Also, the plug has a relatively thin tubular member 96, attached as by welding, which extends downwardly with the bore of the wear bushing and overlaps the top of the cam ring. This tubular member 96 protects the inner bore of the wear bushing at this time.
The wear bushing 14 is bell shaped and is supported on an upwardly facing conical surface 100 on the casing hanger between the main body section 44 and the upper thin end section 54 of the casing hanger 12 and is provided with an offset, relatively thin, relatively long, cylindrical neck portion 102. The inner bore 104 of the wear bushing is substantially the same as the inner bore 106 of the casing hanger so that neither will wear significantly different than the other during subsequent operations on the well. In the lower end of the neck portion 102, immediately above the casing hanger 12, is a key 108 (FIG. 4) fastened in a recess 110 in the wear bushing by a bolt 112 (one shown). Key 108 extends radially outwardly beyond the outer wall of casing hanger 12 to engage a keyslot 114 in the packoff drive nut 26. As more clearly shown in FIG. 6, on the inner side of the wear bushing and above the first mentioned key 108 is a keyslot 116 to receive a second key 118 fastened in a recess 120 to the plug 40 by bolts 122 so that rotation of the plug 40 will transmit torque through the key 118 to the wear bushing 14 which, in turn, will rotate the packoff assembly 16 via the first key 108. Again, while only one set of key/key slots are shown, more such sets are provided around the periphery of the components.
Thus, as mentioned previously, counter-clockwise rotation of the stem 22 will move the running nut 30 axially downwardly against the wedge 32 to urge the cam ring 34 outwardly and into engagement with the casing hanger. Clockwise rotation of the stem 22, on the other hand, will thread the running nut 30 upwardly so that its rim 72 will eventually engage the rim 74 of the wedge sleeve 70 pulling the wedge 32 upwardly and out of engagement with the casing hanger. The dead band or free axial movement of the running nut 30 upwardly for some distance before running nut rim 72 engages the rim 74 of the wedge sleeve, provides a safety factor against accidental release of the running tool for the casing hanger. Also, the splines together with the high lead threads 82 and 84 on the running nut and plug provide a rapid transport and thus rapid release of the running tool from the casing hanger. The continued rotation of the stem 22 and continued upward movement of the running nut 30 will cause the top end 124 of the running nut 30 to engage a shoulder 126 on the plug 40. Since further rotation is prevented when the running nut 30 is in this position, the running nut 30 becomes a driving element whereby continued rotation of the stem will drive the plug 40 to ultimately transmit rotational movement to the packoff assembly 16. It is also pointed out that due to the high pitch of the threads 82 and 84, the running nut will not be tightly engaged in its position against the shoulder 126 such that the running nut can be easily broken out for further use of the running tool despite the high torque applied through the running nut to set the packoff seal.
The wear bushing neck portion 102 adjacent the key 108 has a latching mechanism 130. One is shown in FIGS. 6 and 9, although more are shown disposed around the wear bushing in FIG. 4. This latching mechanism 130 comprises a relatively flat leaf spring 132 positioned in a recess 134 in the wear bushing 14 and fastened to the wear bushing by screw 136. The leaf spring 132 has a radially outwardly extending finger 140 which engages the inner wall (threads 56) of the packoff drive nut 26 and is held in retracted position against the bias of the leaf spring 132 when the packoff drive nut 26 is in the position as shown in FIG. 1 and FIG. 6. When the packoff drive nut 26 is driven to its packoff set position, the bias of the leaf spring 132 will urge the finger 140 into a slot 142 formed in the top of the packoff drive nut 26, thus latching the wear bushing 14 to the packoff assembly 16 (see FIGS. 8 and 9). The bias of the leaf spring 132 will not prevent disengagement and retrieval of the wear bushing 14 by a subsequent running tool operation. The wear bushing is provided with J-slots (not shown) for connection to a tool to retrieve the bushing when desired.
The packoff assembly 16, as more clearly shown in FIG. 7, includes the packoff drive nut 26 with internal threads 56 in engagement with the external threads 52 on the casing hanger and a packoff seal portion 144 connected to the packoff drive nut 26. The drive nut is also provided with ports 145 and passages 146 for flowby during the cementing operation. While the packoff seal portion 144 is conventional, and more fully described in the U.S. Pat. No. 3,797,864, supra, it can be seen to includes a swivel connection accomplished by a split retainer ring 148 (FIGS. 3, 4, 7 and 8) mounted in an internal groove 150 in a support ring 152 and an external groove 154 in the packoff drive nut 26. A thrust bearing 156 is provided between the packoff drive nut 26 and the support ring 152 so that the packoff drive nut 26 can be rotated without rotating the support ring 152. The lower end of the support ring 152 engages and supports the upper end of a cylindrical resiliently deformable packing ring 160 by a dovetail connection 162. A lower abutment ring 164 is connected to the packing ring 160 by a dovetail connection 166.
Attention is now directed to FIGS. 1, 5 and 8 and to the top of the plug 40 and running tool stem 22.
The centralizer fins 42 are radially outwardly extending, relatively thin plates, each fixed, as by welding, at its lower end to a retaining ring 170 which surrounds and engages the plug 40. The ring 170 is connected to the plug 40 by a plurality of bolts 172 through a split ring 174 with a rim 176 in a suitable groove 180. Groove 180 thus forms a flange 182 between the rim 176 and the retainer ring 170 to latch the fins 42 to the plug. The upper end of the plates are each provided with a second retainer ring 186, attached as by welding thereto, surrounding and engaging the stem. Ring 186 is similar to ring 170 and like ring 170 has a split ring 190 seated in a groove 192 in the stem. Split ring 190 is attached to ring 186 by bolts 194. The ring/bolt/groove assemblies 170-194 attach the centralizer fins to the plug 40 and stem 22. The centralizer fins are L-shaped in elevation as shown in FIG. 1 and extend radially outwardly to engage the inside surface of the wellhead housing and serve to space and orient the running tool 20 vertically within the wellhead as well as to act as a bushing between the stem and the wellhead housing bore. A protector ring 196 surrounds the fins to protect and help maintain the fins oriented. The centralizer fins via the ring/bolt/groove assemblies 170-194 also serve to retain the plug in position relative to the stem 22.
From the foregoing, it can be seen that for certain circulating and cementing operations, there is a flowby through the passages 46, the annular seal area 28, the ports 145 and passages 146 in the packoff drive nut (FIGS. 1, 3, 7 and 8) through the ports 200 in the wear bushing and out through the spaces between the centralizer fins. This is represented by the arrow 204 in FIG. 1.
Again, after the circulating and cementing operation, clockwise rotation of the stem 22 will cause upward movement of the running nut 30 on the threads on the plug 40 and at the same time a downward movement of the packoff assembly 16 by reason of rotation of the running nut 30, plug 40 and wear bushing 14. Continued rotation of the stem 22 will cause the packoff drive nut 26 to engage the lower seat 50 on the casing hanger and expand the elastomeric seal 160 thus sealing the angular seal area 28 against leakage. This is depicted in FIG. 10. The lower abutment ring 164 also engages a conical shoulder 206 on a split ring 210 to urge the latter into a groove 212 in the wellhead housing 10 to lock the casing hanger within the well bore. The split ring 210 is supported on a ring 214 threaded on the casing hanger.
At this time, the efficacy of the seal is tested by pressurizing the area above the running tool, etc. The O-ring seals 216 between the casing hanger and wear bushing (two seals shown) and O-ring seals 218 between the wear bushing and plug (three shown) prevent leakage between these named components so that the seal of the set packoff can be tested.
It should be pointed out also at this time that rotation of the packoff drive could begin before the running nut reaches its uppermost position due to friction, debris, etc., causing the plug and wear bushing to rotate, but in any event, as the packoff assembly begins to set, this frictional phenomena will be overcome and the running nut will continue to thread upwardly until it reaches its uppermost position where it becomes a drive element. The ability of the running tool to be released prior to the setting of the packoff also has the advantage of retrieving the running tool in the event the packoff cannot be properly set for whatever reason.
The running nut 30, in the meantime, has freed the cam ring 34 of engagement with the casing hanger so that the plug 40, running nut 30, wedge 32, cam ring 34 and bottom nut 36 are now free to be withdrawn.
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A running tool (20) comprising a stem (22) with a plug (40), a running nut (30), a wedge (32), a cam ring (34), and a bottom nut (36) together releasably connect and support a casing hanger (12), wear bushing (14) and packoff assembly (16) thereon. The bottom nut (36) supports the cam ring (34) and is wedged into engagement with the casing hanger (12) by downward axial movement of the running nut (30). A packoff assembly (16) is threaded on the casing hanger (12) and arranged so that rotation of the plug (40) and stem (22) rotates the wear bushing (14) and the packoff assembly (16) to set the packoff.
The casing hanger (12), wear bushing (14) and packoff assembly (16) are lowered on the running tool (20) into final position within the wellhead. The running tool (20) is released by rotation of the stem (22) which raises the running nut (30), disengages the wedge (32) and allowing the cam ring (34) to disengage the casing hanger (12). A dead band between the wedge (32) and running nut (30) prevents accidental release of the running tool (30) form the casing hanger (12), and on further rotation, the running nut (30) becomes a driving element for threading the packoff assembly (16) so as to set the packoff.
Important features of the invention include releasability of the running tool (20) before setting the packoff, if necessary, the aforementioned safety feature, and the capability of releasing the running nut (30) upon the application of low torque after the application of high torque thereto as a driving element.
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TECHNICAL FIELD
This invention relates to winglets adapted to reduce the induced drag created by an aircraft's wings when they create lift. More particularly, it relates to the provision of a winglet that is continuously curved from where it joins the outer end of the wing out to its outer end or tip and the curvature at least closely approximates the curvature of a conical section, viz. has elliptical, parabolic or hyperbolic curvature.
BACKGROUND OF THE INVENTION
Lifting surfaces (wings) create drag when they create lift. This drag-due-to-lift is called “induced drag.” Aerodynamic theory shows that for essentially planar wings (wings that line essentially in the x-y plane), that the induced drag is minimized if the lift on the wing is distributed elliptically along the span of the wing. That is, the lift per unit span as a function of spanwise position should vary elliptically, with the largest lift per unit span at the wing centerline, and with the lift per unit span gradually dropping in an elliptical manner as the tip is approached. This theoretical result is well known, and many aircraft wings have been constructed with elliptical wing planforms to ensure that the lift does, in fact, vary in an elliptical fashion. The British Spitfire is a classic example of an aircraft wing constructed in an elliptical shape to take advantage of this theoretical result.
The purpose and operation of “winglets” is described in “Aerodynamics, Aeronautics and Flight Mechanics”, by Barnes W. McCormick, and published 1979 by John Wiley & Sons, Inc. (pages 215-221). Known winglet constructions in the patent literature are disclosed by U.S. Patents: No. 4,017,041, granted Apr. 12, 1977 to Wilbur C. Nelson; No. 4,190,219, granted Feb. 26, 1980, to James E. Hackett; No. 4,205,810, granted Jun. 3, 1980, to Kichio K. Ishimitsu; No. 4,240,597, granted Dec. 23, 1990, to Roger R. Ellis, W. Martin Gertsen and Norman E. Conley; No. 4,245,804, granted Jan. 20, 1981, to Kichio K. Ishimitsu and Neal R. Van Devender; No. 4,714,215, granted Dec. 22, 1987, to Jeffrey A. Jupp and Peter H. Rees; No. 5,275,358, granted Jan. 4, 1994 to Mark I. Goldhammer and Karela Schippers; No. 5,348,253, granted Sep. 20, 1994 to Lewis B. Gratzer and No. 5,407,153, granted Apr. 18, 1995 to Phillip S. Kirk and Richard Whitcomb.
FIGS. 1-4 of the drawing are identical to FIGS. 1, 2, 4 and 11 in U.S. Pat. No. 5,275,358. Referring to FIG. 1, the aircraft ( 2 ) basically comprises an aircraft body ( 4 ), left and right wings ( 6 ), and a tail section ( 8 ). A winglet ( 10 , 110 ) is shown at the outer end of each wing ( 6 ). A coordinate system is defined for the aircraft ( 2 ) in the following manner. A longitudinal axis (x) is defined to extend through the center of w the aircraft body ( 4 ) in the fore and aft directions. Further, a vertical axis (z) is defined in the up and down directions, while a transverse axis (y) is defined in the left and right directions. The longitudinal axis (x), vertical axis (z) and transverse axis (y) are orthogonal to each other and meet at an origin located at the foremost plane of the aircraft ( 2 ).
Referring to FIGS. 2 and 3, a winglet ( 16 ), which is generally trapezoidal in shape, is joined to the wingtip ( 12 ) so that the winglet ( 16 ) upwardly extends from the wing ( 6 ). A strake is indicated by reference character ( 16 a ) in FIG. 2 . The wing ( 12 ) (FIG. 2) has upper and lower wing surfaces ( 18 ) and ( 20 ), a wing leading edge ( 22 ), and a wing trailing edge ( 24 ). Similarly, the winglet ( 16 ) has upper and lower winglet surfaces ( 26 ) and ( 28 ), a winglet leading edge ( 30 ), a winglet trailing edge ( 32 ), and a wing/winglet intersection ( 14 ). Conventionally, the terms “upper” and “lower” used in reference to the winglet ( 16 ) generally corresponds to the “inner” and “outer” directions, respectively. This convention will be followed herein. The winglet ( 16 ) is swept back at an angle (α) from the vertical z-axis at least equal to the sweep angle of the leading edges of the wings at the wing tip ( 14 ) relative to the transverse y-axis (FIG. 2 ). The winglet ( 16 ) is also canted at a cant angle from a plane parallel to the (x) and (y) axis (FIG. 3 ). Two methods of defining the curvature of the aft portions of the air foils of the wing ( 12 ) and winglet ( 16 ) are set forth in U.S. Pat. No. 5,275,358, commencing in column 4, at line 7, and continuing into column 5.
FIG. 4 in the drawing is identical to FIG. 11 in U.S. Pat. No. 5,275,358. It is prior art to the present invention and constitutes the invention of Pat. No. 5,275,358. Referring to FIG. 4, the tip of the wing ( 6 ) is designated ( 112 ). Point ( 114 ) is where the wing reference plane ( 148 ) intersects the winglet reference plane ( 150 ). The winglet ( 116 ) is generally trapezoidal in shape. It extends upwardly from the wing tip ( 112 ) and the inner section ( 114 ). The wing tip ( 112 ) has upper and lower wing surfaces ( 118 and 120 ), a wing leading edge ( 122 ) and a wing trailing edge. The winglet ( 116 ) has upper and lower winglet surfaces ( 126 and 128 ), a winglet leading edge ( 130 ), a winglet trailing edge and a winglet root. Generally, the wing/winglet configuration ( 110 ) of U.S. Pat. No. 5,275,358 (FIG. 4) has three primary features. Firstly, the aft portion of the upper wing and winglet surfaces ( 118 and 129 ) are flattened to prevent flow separation at the wing/winglet intersection ( 114 ). Secondly, the wing and winglet leading edges ( 122 and 130 ) are drooped downwardly to prevent premature shockwave development. Thirdly, the winglet ( 116 ) is not canted outwardly, so the wing bending moments are not substantially increased by the addition of the winglet ( 116 ). These primary features and certain secondary features are described in detail in U.S. Pat. No. 5,275,358.
FIG. 5 of the drawing is identical to FIG. 1B of U.S. Pat. No. 5,348,253. Referring to FIG. 5, what is referred to as “a blended winglet” is shown connected to a typical wing end portion ( 1 ). The winglet chord equals the wing tip chord at the attachment line ( 3 ). A transition section ( 2 ) is bounded by the transition line ( 3 ) and a chordwise line ( 4 ) designating the transition end of the winglet ( 9 ). The nearly planar outer portion of the winglet ( 9 ) is generally straight from the transition end ( 4 ) to the tip ( 5 ). A first feature of the FIG. 5 wing/winglet arrangement is a continuous monotonic chord variation bounded by a leading edge curve and a trailing edge curve ( 8 ). These curves are tangent to the wing leading edge and trailing edge respectively at the winglet attachment line ( 3 ) and are also tangent to the leading edge and trailing edges respectively of the straight section ( 9 ) at line ( 4 ). The leading edge curve ( 7 ) is selected to provide a smooth gradual chord variation in the transition and also, to limit the leading edge sweep angle to less than about 65°. This is necessary to avoid vortex shedding from the leading edge which would comprise the surface loading and thereby increase drag. The shape of the trailing edge curve ( 8 ) is generally not critical but is selected to correspond to the airfoil chord and twist required to achieve optimum loading. This restriction will usually allow the wing and winglet trailing edges to lie in the same plane which is desirable functionally and esthetically.
The second feature is a continuous monotonic variation of cant angle. It is stated that the rate of curvature R must be large enough to accommodate the chord variation in the transition section and allow the practical achievement of optimum aerodynamic loading and minimum interference between wing and winglet. The radius and curvature criteria is given below in terms of a parameter, K r having fairly narrow limits: R h = K R cos ( φ 4 2 + π 4 ) / cos φ 4 ; 35 < K R < .50
where,
h=winglet height measured along a normal to the wing chord plane
φ 4 =cant angle of the planar section
Λ H =maximum sweep angle of the leading edge curve 7
K R =curvature parameter (select lower limit if practical)
More details respecting the winglet curvature are set forth in U.S. Pat. No. 5,348,253.
BRIEF SUMMARY OF THE INVENTION
The present invention includes the discovery that when winglets are attached to the wing tips, the minimum induced drag is obtained when the lift is distributed in a generally elliptical fashion both in the spanwise and vertical directions. The present invention utilizes winglets having a generally elliptical shape in the z-y plane, assuring that the wing loading closely approximates the ideal lift distribution. This results in minimum induced drag and reduced fuel consumption. The present invention also includes the discovery that the winglets will provide reduced induced drag when the winglets have a generally parabolic shape or a generally hyperbolic shape in the y-z plane.
The present invention includes providing the wings of an aircraft with winglets of a unique curvature. Each wing has an inner end, an outer end, an upper surface, a lower surface, a leading edge and a trailing edge. Each winglet has an inner end, an outer end, an upper surface, a lower surface, a leading edge and a trailing edge. The inner end of each winglet is connected to the outer end of its wing. The upper and lower surfaces of the winglets and the leading and trailing edges of the winglets are continuations of the upper and lower surfaces of the wing and the leading and trailing edges of the wing. Each winglet follows a generally elliptical curve as it extends from its inner end out to its outer end. The generally and said elliptical curve has a major axis that extends substantially perpendicular to the wing reference plane and substantially intersects the location where the outer end of the wing is joined to the inner end of the winglet.
In preferred form, the generally elliptical curve has a minor axis substantially perpendicular to the major axis, and that is spaced above the outer end of the winglet. The minor axis intersects the major axis at a center and a diagonal line extends from the center out to the outer end of the winglet and makes an acute angle of about forty-five to ninety (45°-90°) degrees with the major axis.
In preferred form, at its outer end the winglet has a cant angle of substantially about forty-five to about ninety degrees (45°-90°).
In preferred form, each wing has a dihedral angle of substantially about zero to fifteen degrees (0°-15°).
Other objects, advantages and features of the invention will become apparent from the description of the best mode set forth below, from the drawings, from the claims and from the principles that are embodied in the specific structures that are illustrated and described.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Like reference numerals are used to designate like parts throughout the several views of the drawing, and:
FIG. 1 is a pictorial view taken from above and looking towards the front, top and one side of an airplane that includes winglets on its wings, such view also constituting FIG. 1 of the aforementioned U.S. Pat. No. 5,275,358;
FIG. 2 is a cross sectional view taken through the right wing of FIG. 1, showing the main wing span in section and sending a side elevational view of a winglet, such view also constituting FIG. 2 of U.S. Pat. No. 5,275,358;
FIG. 3 is a fragmentary front elevational view of the winglet of FIG. 2 and enjoining portion of the main span of the wing, such view also constituting FIG. 4 of U.S. Pat. No. 5,275,358;
FIG. 4 is a view like FIG. 3, but of a different prior art winglet, such view also constituting FIG. 11 of U.S. Pat. No. 5,275,358;
FIG. 5 is a view like FIGS. 3 and 4 but of yet another prior art winglet, such view also constituting FIG. 1B of U.S. Pat. No. 5,348,253;
FIG. 6 is a view like FIGS. 3-5, but of a winglet constructed in accordance with the present invention;
FIG. 7 is a fragmentary pictorial view of the winglet shown by FIG. 6, looking towards its forward edge and lower surface;
FIG. 8 is a top plan view of a wing for a MD-80 with winglets;
FIG. 9 is a view that combines FIGS. 5 and 6, such view showing the FIG. 5 winglet in broken lines and showing the FIG. 6 winglet in solid lines;
FIG. 10 is a drawing of an ellipse taken from a geometry text;
FIG. 11 is a drawing of a parabola taken from the same geometry text as FIG. 10;
FIG. 12 is a drawing of a hyperbola taken from the same geometry text as FIGS. 10 and 11;
FIG. 13 is a graph plotting induced drag coefficient with lift coefficient; and
FIG. 14 is a graph plotting percentage in reduction in induced drag versus lift coefficient showing the improvement obtained with the elliptical winglet in comparison to the prior art.
DETAILED DESCRIPTION OF THE INVENTION
The aircraft shown by FIG. 1 includes winglets 10 , 110 which are representative of both the prior art winglets and the winglets of the present invention. The prior art winglets shown by FIGS. 2-5 have been described above. The winglets of the present invention will now be described with respect to FIGS. 6-11.
Referring first to FIG. 6, showing an embodiment of the invention, the outer end of the wing 200 meets the inner end of the winglet 202 at intersection 204 . The major axis 206 of an ellipse is shown to extend perpendicular to the wing reference plane and to coincide with the intersection 204 . The minor axis 208 of the ellipse extends perpendicular to the major axis and intersects the major axis at center 210 . If one were to draw a diagonal line 212 from the center 210 to the outer end or tip 214 of the winglet 202 , an acute angle 216 would be defined between the line 212 and the major axis 206 . In FIG. 6, the dihedral angle of the wing 200 is designated 218 . The winglet height is designated 220 and the winglet span is designated 222 . The wing tip cant angle is designated 224 . According to the invention, the winglet 202 curves upwardly and outwardly from intersection 204 to the outer end or tip 214 of the winglet 202 .
A cross sectional view taken at intersection 204 and looking outwardly towards the winglet 202 in elevation would look substantially like FIG. 2 . The winglet 202 has a generally trapezoidal shape in side elevation (FIG. 7) and the leading edge makes an angle α with a vertical line, as best shown in FIG. 2 .
The winglet 202 preferably has a curvature in the y-z plane that at least approximates a sector of an ellipse measured from intersection station 204 outwardly to the winglet outer end or tip 214 . At intersection station 204 , the curvature of the winglet surfaces meets the wing surfaces substantially at a tangent. As the winglet 202 extends outwardly from intersection station 204 , its curvature in the y-z plane changes in substantially the same way that an elliptical surface changes. The elliptical sector is identified in FIG. 10, between major axis 204 and point 214 representing the position of the winglet tip 214 on the ellipse.
Referring to FIGS. 6-8, the wing 200 has a forward edge 226 , a rearward or trailing edge 228 , an upper surface 230 and a lower surface 233 (FIG. 6 ). The winglet 202 has a forward edge 232 , a rearward edge 234 , an upper surface 236 (FIG. 6) and a lower surface 238 . As best shown by FIGS. 6 and 7, the upper and lower surfaces 236 , 238 of the winglet 202 , and the leading and trailing edges 232 , 234 of the winglet 202 , are continuations of the upper and lower surfaces 230 , 232 and the leading and trailing edges 226 , 228 of the wing 200 .
Referring to FIG. 8, the wing 200 has a sweep angle 201 . The wingspan extending from the aircraft centerline C/L out to where the wing 200 meets the winglet 202 is designated WS. The span of the winglet is designated WS′. The distance WS is smaller and the distance WS′ is larger than it is in the prior art aircraft. This results in reduced induced drag.
The invention differs from all prior art winglet designs in two important aspects. First, in preferred form, the present design closely follows the ideal elliptical shape, while no prior winglet follows the ideal elliptical shape, or even attempts to approximate it. The other conic sections, viz. a parabolic section and a hyperbolic section, include curves that approximate the ideal elliptical shape and thus they are included in the invention. These curves are shown by FIGS. 11 and 12.
FIG. 13 is a graph plotting induced drag coefficient with lift coefficient. This graph shows that the elliptical winglet of the present invention reduces induced drag on the MD-80 aircraft by ten percent (10%). It is believed that a near elliptical curvature and parabolic and hyperbolic curvatures will also significantly reduce induced drag. Second, the present design is continuously curved in the y-z plane (front view), while all prior winglets have an essentially planar winglet shape when viewed from the front, perhaps with a brief curved transition section between the wing and the winglet. Owing to the conical section nature of the winglet curvature in the y-z plane, the radius of curvature is at a minimum at 204 where the outer end of the wing 200 meets the inner end of the winglet 202 . As the winglet 202 extends outwardly from intersection 204 , the radius of curvature progressively and continuously increases following generally at least a conical section curvature and preferably following an elliptical curvature.
The superior performance of the elliptical winglet design in comparison to the prior art is illustrated in FIG. 14 . This figure shows the percentage reduction in induced drag obtained when an MD-80 aircraft is fitted with an elliptical winglet, and a winglet designed in conformance with Pat. No. 5,348,253. The figure shows that the elliptical winglet reduces the MD-80 induced drag by approximately ½ percent in comparison to the prior art. This ½ percent reduction in induced drag would result in an annual fuel cost savings of approximately $15,000 for an MD-80 in commercial airline service, based on a fuel cost of approximately $0.90 per gallon. This savings clearly illustrates the value of the elliptical winglet described in this patent.
The illustrated embodiments are only examples of the present invention and, therefore, are non-limitive. It is to be understood that many changes in the particular structure, materials and features of the invention may be made without departing from the spirit and scope of the invention. Therefore, it is my intention that my patent rights not be limited by the particular embodiments illustrated and described herein, but rather determined by the following claims, interpreted according to accepted doctrines of claim interpretation, including use of the doctrine of equivalents and reversal of parts.
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An aircraft with swept back wings has winglets ( 202 ) at the outer ends of its wings ( 200 ). The winglets ( 202 ) curve upwardly as they extend outwardly from their intersection ( 204 ) with the wings ( 200 ). The curvature of the winglets ( 202 ) at least approximates a conical section curvature, e.g. an elliptical based on an ellipse having a major axis that extends vertically and coincides with the intersection ( 204 ) of the outer end of the wing ( 200 ) and the inner end of the winglet ( 202 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. patent application Ser. Nos. 08/904,084, 08/904,085, 08/904,086 and 08/904,088; all of the aforementioned applications were filed on Jul. 31, 1997 and are owned by LSI Logic Corporation.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of multimedia systems, and more particularly to a video decoding device having the ability to meet particular predetermined transmission and display constraints. The video decoding device is particularly suited for Motion Picture Expert Group (MPEG) data compression and decompression standards.
2. Description of the Related Art
Multimedia software applications including motion pictures and other video modules employ MPEG standards in order to compress, transmit, receive, and decompress video data without appreciable loss. Several versions of MPEG currently exist or are being developed, with the current standard being MPEG-2. MPEG-2 video is a method for compressed representation of video sequences using a common coding syntax. MPEG-2 replaces MPEG-1 and enhances several aspects of MPEG-1. The MPEG-2 standard includes extensions to cover a wider range of applications, and includes the addition of syntax for more efficient coding of interlaced video and the occurrence of scalable extensions which permit dividing a continuous video signal into multiple coded bitstreams representing video at different resolutions, picture quality, or frame rates. The primary target application of MPEG-2 is the all-digital broadcast of TV quality video signals at coded bitrates between 4 and 9 Mbit/sec. MPEG-1 was optimized for CD-ROM or applications transmitted in the range of 1.5 Mbit/sec, and video was unitary and non-interlaced.
An encoded/compressed data stream may contain multiple encoded/compressed video and/or audio data packets or blocks. MPEG generally encodes or compresses video packets based on calculated efficient video frame or picture transmissions.
Three types of video frames are defined. An intra or I-frame is a frame of video data including information only about itself. Only one given uncompressed video frame can be encoded or compressed into a single I-frame of encoded or compressed video data.
A predictive or P-frame is a frame of video data encoded or compressed using motion compensated prediction from a past reference frame. A previous encoded or compressed frame, such as an I-frame or a P-frame, can be used when encoding or compressing an uncompressed frame of video data into a P-frame of encoded or compressed video data. A reference frame may be either an I-frame or a P-frame.
A bidirectional or B-frame is a frame of video data encoded or compressed using motion compensated prediction from a past and future reference frame. Alternately, the B-frame may use prediction from a past or a future frame of video data. B-frames are particularly useful when rapid motion occurs within an image across frames.
Motion compensation refers to the use of motion vectors from one frame to improve the efficiency for predicting pixel values of an adjacent frame or frames. Motion compensation is used for encoding/compression and decoding/decompression. The prediction method or algorithm uses motion vectors to provide offset values, error information, and other data referring to a previous or subsequent video frame.
The MPEG-2 standard requires encoded/compressed data to be encapsulated and communicated using data packets. The data stream is comprised of different layers, such as an ISO layer and a pack layer. In the ISO layer, packages are transmitted until the system achieves an ISO end code, where each package has a pack start code and pack data. For the pack layer, each package may be defined as having a pack start code, a system clock reference, a system header, and packets of data. The system clock reference represents the system reference time.
While the syntax for coding video information into a single MPEG-2 data stream are rigorously defined within the MPEG-2 specification, the mechanisms for decoding an MPEG-2 data stream are not. This decoder design is left to the designer, with the MPEG-2 spec merely providing the results which must be achieved by such decoding.
Devices employing MPEG-1 or MPEG-2 standards consist of combination transmitter/encoders or receiver/decoders, as well as individual encoders or decoders. The restrictions and inherent problems associated with decoding an encoded signal and transmitting the decoded signal to a viewing device, such as a CRT or HDTV screen indicate that design and realization of an MPEG-compliant decoding device is more complex than that of an encoding device. Generally speaking, once a decoding device is designed which operates under a particular set of constraints, a designer can prepare an encoder which encodes signals at the required constraints, said signals being compliant with the decoder. This disclosure primarily addresses the design of an MPEG compliant decoder.
Various devices employing MPEG-2 standards are available today. Particular aspects of known available decoders will be described.
Frame Storage Architecture
Previous systems used either three or two and a half frame storage for storage in memory.
Frame storage works as follows. In order to enable the decoding of B-frames, two frames worth of memory must be available to store the backward and forward anchor frames. Most systems stored either a three frame or two and a half frames to enable B-frame prediction. While the availability of multiple frames was advantageous (more information yields an enhanced prediction capability), but such a requirement tends to require a larger storage buffer and takes more time to perform prediction functions. A reduction in the size of memory chips enables additional functions to be incorporated on the board, such as basic or enhanced graphic elements, or channel decoding capability. These elements also may require memory access, so incorporating more memory on a fixed surface space is highly desirable. Similarly, incorporating functional elements requiring smaller memory space on a chip is also beneficial.
Scaling
The MPEG-2 standard coincides with the traditional television screen size used today, thus requiring transmission having dimensions of 720 pixels (pels) by 480 pixels. The television displays every other line of pixels in a raster scan The typical television screen interlaces lines of pels, sequentially transmitting every other line of 720 pels (a total of 240 lines) and then sequentially transmitting the remaining 240 lines of pels. The raster scan transmits the full frame at 1/30 second, and thus each half-frame is transmitted at 1/60 second.
For MPEG storage method of storing two and a half frames for prediction relates to this interlacing design. The two and a half frame store architecture stores two anchor frames (either I or P) and one half of a decoded B frame. A frame picture is made up of a top and a bottom field, where each field represents interlaced rows of pixel data. For example, the top field may comprise the first, third, fifth, and so forth lines of data, while the bottom field comprises the second forth, sixth, and so on lines of data. When B frames are decoded, one half the picture (either the top field or the bottom field) is displayed. The other half picture must be stored for display at a later time. This additional data accounts for the "half frame" in the two and a half frame store architecture.
In a two frame store architecture, there is no storage for the second set of interlaced lines that has been decoded in a B-frame. Therefore, an MPEG decoder that supports a two frame architecture must support the capability to decode the same picture twice in the amount of time it takes to display one picture. As there is no place to store decoded B-frame data, the output of the MPEG decoder must be displayed in real time. Thus the MPEG decoder must have the ability to decode fast enough to display a field worth of data.
A problem arises when the picture to be displayed is in what is called the "letterbox" format. The letterbox format is longer and narrower than the traditional format, at an approximately 16:9 ratio. Other dimensions are used, but 16:9 is most common. The problem with letterboxing is that the image is decreased when displayed on screen, but picture quality must remain high. The 16:9 ratio on the 720 by 480 pel screen requires picture on only 3/4 of the screen, while the remaining 1/4 screen is left blank. In order to support a two-frame architecture with a letterboxing display which takes 3/4 of the screen, a B-frame must be decoded in 3/4 the time taken to display a field of data.
The requirements to perform a two frame store rather than a two and a half or three frame store coupled with the desire to provide letterbox imaging are significant constraints on system speed which have not heretofore been achieved by MPEG decoders.
It is therefore an object of the current invention to provide an MPEG decoding system which operates at 54 Mhz and sufficiently decodes an MPEG data stream while maintaining sufficient picture quality.
It is a further object of the current invention to provide an MPEG decoder which supports two frame storage.
It is another object of the current invention to provide a memory storage arrangement that minimizes on-chip space requirements and permits additional memory and/or functions to be located on the chip surface. A common memory area used by multiple functional elements is a further objective of this invention.
It is yet another object of the current invention to provide an MPEG decoder which supports signals transmitted for letterbox format.
SUMMARY OF THE INVENTION
According to the current invention, there is provided a system for decoding an MPEG video bitstream comprising several macroblocks of data. The system operates at 54 Mhz and has the ability to perform 2 frame store and decode letterbox format video data. The system comprises a macroblock core (MBCORE) which includes a processor for processing the video bitstream data. The MBCORE also includes a variable length decoder that extracts DCT coefficients from the encoded bitstream. These DCT coefficients are used to perform IDCT in subsequent stages of decoding.
The MBCORE also includes a parser which parses the video bitstream macroblocks into multiple data blocks used in subsequent stages of decoding.
The system further includes a transformation/motion compensation core (TMCCORE) which is divided into multiple stages. The TMCCORE includes an inverse discrete cosine transform first stage, an intermediate memory (transpose RAM), and an inverse discrete cosine transform second stage. The inverse discrete cosine transform first stage passes data to the memory. The inverse discrete cosine transform second stage receives data from memory.
The inverse discrete cosine transform first stage has the ability to operate on a first data block while the inverse discrete cosine transform second stage simultaneously operates on a second data block. Further, the MBCORE has the ability to operate on one macroblock while the TMCCORE simultaneously operates on a second macroblock. This staggered processing architecture provides the ability to perform two-frame store of letterbox format video data within the 54 Mhz constraints.
The TMCCORE receives the discrete cosine transform data from the MBCORE and calculates and reconstructs a frame therefrom using motion compensation. Motion compensation is provided using the video bitstream information as processed by the MBCORE as well as data available from a reference subsystem. The MBCORE has the ability to operate on a first set of data, such as data from a first macroblock, while the TMCCORE simultaneously operates on a second set of data, such as data from a second macroblock. Thus the MBCORE and the TMCCORE can operate simultaneously on two separate macroblocks of video data.
The system has the ability to reconstruct a picture from the inverse discrete cosine transformed data and motion data received from the reference subsystem. The TMCCORE reconstructs the picture from one macroblock while the inverse discrete cosine transform first and second stages simultaneously operate on data from the macroblock. Alternately, reconstruction may occur while second stage processing and MBCORE functions occur.
The system also decodes fixed length data words comprising multiple variable length objects. The system has the ability to decode a VLD (variable length DCT (discrete cosine transform)) in every clock cycle. The MBCORE receives one DCT coefficient per cycle. Data in the bitstream is compressed, and thus the MBCORE must extract the necessary symbols from the bitstream, which may vary in size. The largest symbol which must be extracted is 32 bits according to the MPEG standard. The inventive method and system disclosed herein, also called the data steering logic, enables the MBCORE to read the symbols irrespective of symbol size.
The MBCORE receives compressed video data in a linear fashion. As the MBCORE parses the data, compressed data consumed by the system is flushed out of the register and new data is shifted into the register. This flushing of consumed data and maintenance of unconsumed data is performed by the data steering logic.
The inventive system includes multiple floating point registers, preferably two, for holding the fixed length data words. The system also includes an arrangement for tracking a total number of used bits and a rotating shift register, which is a circular buffer. The system has a multiplexer arrangement which transfers variable length objects from the floating point registers to the rotating shift register. The tracking arrangement counts the bits used in transferring variable length objects to the rotating shift register. Further, the floating point registers access additional fixed length data words when emptied.
The tracking arrangement comprises a summation block and a total used bits register, wherein the summation block sums bits used for each variable length object with the contents of the total bits used register to form the total number of used bits. The total used bits are fed back and summed within the total used bits register.
The multiplexer arrangement comprises multiple multiplexers, preferably two, where each multiplexer is associated with one floating point register and is capable of receiving new data. The multiplexers feed data back to each floating point register, and each multiplexer transfers data from its associated floating point register to the rotating shift register. The transfer of variable length objects may require data contained in more than one floating point register and transfer using more than one multiplexer.
The system also includes a resultant floating point register, where the rotating shift register shifts complete data words data to the resultant floating point register.
Performance of the system is as follows. The system, including the various registers and bit counters, are initialized. Subsequently, the system loads at least one fixed length data word into the floating point register. The system then determines the size of each variable length data object and computes a total number of used bits based on each variable length data object size. The system then transfers the variable length data object from at least one register to the rotating register and refills any empty floating point registers with an additional fixed length data word. The system repeats the determining, computing, transferring, and refilling steps until all registers are empty and no further fixed length data words are available. The system further comprises a horizontal half pixel compensation arrangement including multiple adders and multiplexers which perform horizontal half pixel compensation using an addition function, a division function, and a modulo function on pixel data. The system has a register bank which provides the ability to store an array of reference data when vertical half pixel compensation is required. The system also has a vertical half pixel compensation arrangement, which also includes multiple adders and multiplexers which perform vertical half pixel compensation using an addition function, a division function, and a modulo function on pixel data.
The system includes an odd pixel interface, such that it accepts reference data at a predetermined uniform rate while accepting odd pixel data from the odd pixel interface one pixel at a time. Reference data and odd pixel data are transferred into and within said system by transferring odd pixel data in a first predetermined cycle, transferring selected reference data in the same first predetermined cycle and transferring additional reference data in at least one subsequent predetermined cycle. Reference and odd pel data may comprise either luma or chroma data. Different picture types, prediction types, and pixel compensation requirements yield different data fetching schemes for luma and chroma data, and different reference motion vector data causes different luma and chroma transference to the motion compensation unit. Luma reference data is shipped in units of 8×16 while chroma reference data is shipped in units of 4×8. All luma reference data is shipped before chroma reference data.
The system also performs reference data averaging between various frames using a B-picture compensation unit, which operates when B-pictures with backward and forward motion vectors or P-pictures with dual-prime prediction occur.
The result of the implementation is a throughput of four pixels per cycle while performing right and down half pixel compensation, and performs half pixel and B-picture and dual prime averaging.
The system also performs an inverse discrete cosine transform (IDCT) calculation within the TMCCORE based on DCT data received from the MBCORE. The system is IEEE compliant and transforms one block (8×8) of pixels in 64 cycles.
The TMCCORE receives the DCT input, produces the matrix (QX t Q)P, or X Q P, in IDCT Stage 1 and stores the result in transpose RAM. IDCT Stage 2 performs the transpose of the result of IDCT Stage 1 and multiplies the result by P, completing the IDCT process and producing the IDCT output.
The IDCT processor receives 12 bits of DCT data input. The system performs a sign change to convert to sign magnitude, yielding eleven bits of data and a data bit indicating sign. The system performs the matrix function QX t Q, where X represents the DCT data and Q is a predetermined diagonal matrix. The resultant value is adjusted by discarding selected bits, and the system then postmultiplies this with the elements of a predetermined P matrix, and discards selected bits.
The system converts the sign magnitude to 2's complement. The system adds four blocks into each buffer, with the buffers having 22 bits each. A sign change is performed to obtain QX t QP. This completes first stage processing, and data is passed to transpose RAM.
The system subsequently initiates IDCT stage 2, and performs a matrix transpose of QX t QP, yielding (QX t QP) t , performs a 2's complement to sign-magnitude, clips the least significant bit, and postmultiplies the result by the P matrix. This value is sign-magnitude converted back to 2's complement, and altered to obtain the elements of (QX t QP) t P.
Other objects, features, and advantages of the present invention will become more apparent from a consideration of the following detailed description and from the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the MPEG video decoder 100 according to the current invention;
FIG. 2 is a detailed illustration of the TMCCORE in accordance with the current invention;
FIG. 3 presents the timing diagram for the transmission of data through the TMCCORE;
FIG. 4 shows the staggered timing of data transmission through the TMCCORE;
FIG. 5A illustrates the data blocks received by the MBCORE;
FIG. 5B shows the data blocks received by the MBCORE after 16 bits of data have been transmitted to the system;
FIG. 6 shows the hardware implementation of the Data Steering Logic;
FIG. 7 is a flowchart illustrating operation of the Data Steering Logic;
FIG. 8 is a flowchart of the DCT processor multiplication logic;
FIG. 9 illustrates the implementation of IDCT Stage 1 which functionally calculates X Q P;
FIG. 10 is the design for IDCT stage 2, which transposes the result from IDCT Stage 1 and multiplies the resultant matrix by P;
FIG. 11 shows the system design for performing the final functions necessary for IDCT output and storing the values in appropriate positions in IDCT OUTPUT RAM;
FIG. 12 represents the numbering of pels for use in motion compensation; and
FIG. 13 is the mechanization of the motion compensation unit used to satisfy two frame store and letterboxing requirements.
DETAILED DESCRIPTION OF THE INVENTION
The requirements for supporting a two frame architecture as well as letterbox scaling are as follows, using NTSC. Letterbox scaling only transmits 3/4 of a full screen, leaving the top and bottom eighth of the screen blank at all times. For letterbox scaling, a total of 360 (or 3/4 * 480) lines of active video must be displayed. For a two frame store system, with a 45 by 30 macroblock picture, 360 lines of active video divided by 30 * 525 seconds is available, or approximately 0.02286 seconds are available to decode the 45 by 30 macroblock arrangement. With 30 rows of macroblocks, the time to decode one full row of macroblocks is (360/(30 * 525))/30 seconds, or approximately 761.91 microseconds. The time to decode one macroblock is 761.91/45 or 16.391 microseconds. With two frame store, double decoding is necessary, and the time available to decode a macroblock is 16.391/2 microseconds, or 8.465 microseconds.
Decoder Architecture
FIG. 1 illustrates the MPEG video decoder 100 according to the current invention. The system passes the compressed bitstream 101 to MBCORE 102 (Macro Block core), which passes data to TMCCORE 103 (Transformation/Motion Compensation core) and Reference Subsystem 104. TMCCORE 103 passes information to MBCORE 102, and produces reconstructed macroblocks.
The MBCORE 102 operates as both a controller and a parser. The MBCORE 102 primary function is to parse the compressed bitstream 101 and generate DCT coefficients and motion vectors for all macroblocks. The DCT coefficients then pass to the TMCCORE 103 for further processing, and the MBCORE 102 passes the motion vectors to the Reference Subsystem 104 for further processing.
The MBCORE 102 comprises video bitstream symbol extractor 105 and state machines 106. MBCORE 102 reads the compressed bitstream 101 and if the compressed bitstream is in VLC (Variable Length Coding), the MBCORE decompresses the bitstream using the video bitstream symbol extractor 105, detailed below. The MBCORE further comprises DCT processor 107, which enables the MBCORE 102 to calculate and provide DCT coefficients to the TMCCORE 103 and motion vectors to the Reference Subsystem 104.
The TMCCORE 103 receives DCT and motion vector information for a series of macroblocks and performs the inverse discrete cosine transfer for all data received. The TMCCORE 103 receives the discrete cosine transfer data from the MBCORE 102, computes the inverse discrete cosine transform (IDCT) for each macroblock of data, computes a motion vector difference between the current frame and the reference frame by essentially "backing out" the difference between the current frame and reference frame, and combines this motion vector difference with the IDCT coefficients to produce the new frame using motion compensation. The TMCCORE 103 also executes pel compensation on reference data received from the Reference Subsystem 104, and reconstructs the new frame using information from the Reference Subsystem 104 and the MBCORE 102.
The Reference Subsystem 104 receives motion vectors from the MBCORE 102. The Reference Subsystem 104 determines the location of necessary motion related information, such as previous frame data and current frame data, to support the TMCCORE 103 in compensation and reconstruction. The Reference Subsystem 104 acquires such information and provides it to the TMCCORE 103.
As noted above, the timing for performing the necessary parsing, coefficient generation, transmission, and picture reconstruction functions is critical. Data is transmitted to the MBCORE 102 as follows: a slice header and macroblock data passes to the MBCORE 102, followed by the DCT coefficient data for a particular macroblock of data. The slice header and macroblock data take 30 cycles for transmission, and thus the MBCORE does not transmit DCT data for 30 cycles. Transmission of one macroblock of data requires the initial 30 cycle period, followed by six 64 cycle transmissions, and then the procedure repeats.
The MBCORE 102 takes 50 cycles to parse the video bitstream from the slice start code, i.e. a data block indicating the beginning of a particular bitstream arrangement, to generating the first coefficients for the IQ stage of the TMCCORE 103.
Operation of the MBCORE is as follows. The MBCORE initially accepts and parses the 50 cycles up to the block layer. The MBCORE then generates one DCT coefficient per cycle, and takes a total of (64+1) * 5+64 cycles, or 389 cycles, to generate all the DCT coefficients for a given macroblock. The MBCORE passes a total of 384 DCT coefficients (64 * 6) to the TMCCORE 103, which accepts one block of coefficient data into IDCT Stage 1.
A detailed illustration of the TMCCORE is presented in FIG. 2. After a full block of IDCT coefficient data passes through the IDCT Stage 1 data path, which can conceptually be analogized to a pipeline, IDCT Stage 2 computation begins on the IDCT Stage 1 processed data. Hence IDCT Stage 1 data is stored by the system in RAM and the IDCT Stage 1 data is subsequently received by IDCT Stage 2 within the TMCCORE 103. IDCT Stage 1 operates as soon as it receives the data from the MBCORE 102. IDCT Stage 2, however, is one block delayed due to the processing, storage, and retrieval of the IDCT data. The arrangement of the timing of the IDCT stages and the transmission of data within the TMCCORE 103 are presented below.
Data Transmission Method
FIG. 3 presents the timing diagram for the transmission of data through the TMCCORE 103. From FIG. 3, the zero block of data, comprising 64 units of data and taking 64 cycles, is processed in the IQ/IDCT Stage 1 pipeline initially. A gap occurs between the six 64 blocks of data, taking one cycle. The one block of data is subsequently processed by the IQ/IDCT Stage 1 pipeline at the time the IDCT Stage 2 processes the zero block data. Processing continues in a staggered manner until the four block is processed in IDCT Stage 1 and the three block in IDCT Stage 2, at which time the system begins reconstruction of the picture.
With the 4:2:0 ratio, the TMCCORE 103 receives four luminance pixels and two chrominance pixels. At the end of the four luminance pixels, the TMCCORE 103 initiates reconstruction of the picture.
Total time for the process is 64 cycles multiplied by 6 blocks=384 cycles, plus five one cycle gaps, plus the 35 cycles for header processing, plus a trailing five cycles to complete reconstruction, for a total of 429 cycles. Reconstruction takes 96 cycles.
The staggered timing arrangement for processing the data permits the functions of the MBCORE 102 and TMCCORE 103 to overlap. This overlap permits the MBCORE 102 to operate on one macroblock of data while the TMCCORE 103 operates on a second macroblock. Prior systems required full loading of a single macroblock of data before processing the data, which necessarily slowed the system down and would not permit two-frame store and letterbox scaling.
FIG. 4 shows the MBCORE/TMCCORE macroblock decoding overlap scheme. Again, header data is received by the MBCORE 102, followed by zero block data, which are passed to IQ/IDCT Stage 1 processing. TMCCORE IDCT Stage 2 subsequently processes the zero block data, at the same time IQ/IDCT Stage 1 processes one block data. The staggered processing progresses into and through the reconstruction stage. During reconstruction, the five block is received and processed in IDCT Stage 2, at which time the MBCORE begins receipt of data from the subsequent macroblock. Five block and picture reconstruction completes, at which time zero block for the subsequent macroblock is commencing processing within IQ/IDCT Stage 1. This is the beneficial effect of overlapping processing.
In order to perform full merged store processing, wherein the IDCT data and the motion vector data is merged within the TMCCORE 103, both sets of data must be synchronized during reconstruction. From the drawing of FIG. 4, the motion vector data is received at the same time the IDCT Stage 2 data is received and processed. The sum of the IDCT Stage 2 data and the motion vector data establishes the picture during reconstruction, and that picture is then transmitted from the TMCCORE 103.
The total number of cycles required to decode the video bitstream from the slice header and ship out six blocks of coefficients is 429 cycles. The TMCCORE IDCT Stage 2 and Reconstruction takes fewer cycles than the MBCORE parsing and shipping of data. With the staggered processing arrangement illustrated above, the MPEG video processor illustrated here can decode the bitstream in 429 cycles (worst case).
From the requirements outlined above for the letterbox format and two frame store, the minimum frequency at which the MBCORE 102 and the TMCCORE 103 must operate at to achieve real time video bitstream decoding is 1/8.465 microseconds/429 cycles, or 50.67 Mhz. Thus by overlapping the decoding of the macroblocks using the invention disclosed herein, the MBCORE and the TMCCORE together can perform MPEG-2 MP/ML decoding with a two frame store architecture and letterbox decoding with a clock running at 54 Mhz.
Video Bitstream Symbol Extractor/Data Steering Logic
The decoder of FIG. 1 must have the ability to decode a VLD (variable length DCT) in every clock cycle. The MBCORE 102 receives one DCT coefficient per cycle, and comprises in addition to an inverse DCT function a video bitstream symbol extractor 105. Data in the bitstream is compressed, and thus the MBCORE 102 must extract the necessary symbols from the bitstream, which may vary in size. The largest symbol which must be extracted is 32 bits according to the MPEG standard. The data steering logic for the video bitstream symbol extractor permits enables the MBCORE 102 to read the symbols irrespective of symbol size.
The MBCORE 102 receives compressed video data in a linear fashion as illustrated in FIG. 5A. W0,0 represents Word 0, bit 0, while W1,31 represents Word 1, bit 31, and so forth. Time progresses from left to right, and thus the data bitstream enters the video decoder from left to right in a sequential manner as illustrated in FIG. 5A. As parsing is performed, compressed data consumed by the system is flushed out of the register and new data is shifted into the register. This flushing of consumed data and maintenance of unconsumed data is performed by the data steering logic.
FIG. 5B illustrates the appearance of the data after a 16 bit symbol is consumed. The data comprising W0,0 . . . 15 is consumed by the system, leaving all other data behind. The problem which arises is that upon consuming a 16 bit symbol, the next symbol may be 30 bits in length, thereby requiring excess storage beyond the 32 bit single word length. The tradeoff between timing and space taken by performing this shifting function is addressed by the data steering logic.
Data steering logic is presented in FIG. 6. According to the data steering logic, the CPU first instructs the data steering logic to initiate data steering. Upon receiving this initiation signal, the data steering logic loads 32 bit first flop 601 and 32 bit second flop 602 with 64 bits of data. The data steering logic then resets the total -- used -- bits counter 603 to zero and indicates that initialization is complete by issuing an initialization ready signal to the CPU.
Once the MBCORE 102 begins receiving video data, state machines 106 within the MBCORE 102 examine the value coming across the data bus and consume some of the bits. This value is called "usedbits" and is a six bit ([5:0]) bus. The total number of used bits, total -- used[5:0], is the sum of total -- used -- bits[5:0] and usedbits[5:0]. total -- used -- bits are illustrated in FIG. 6 as flop 604. Bit usage via flop 604 and total -- used -- bits counter 603 is a side loop used to track the status of the other flops and barrel shifter 605.
Data is sequentially read by the system and passed to the barrel shifter, and subsequently passed to resultant data flop 608.
For example, the initial value of usedbits is 0. A consumption of 10 bits, representing a 10 bit symbol, by the state machines 106 yields a total used bits of 10. Hence the total -- used is 10. These 10 bits are processed using first flop bank MUX 606 and loaded into barrel shifter 605.
total -- used is a six bit wide bus. The range of values that may be stored using total -- used is from 0 to 63. When the value of total -- used -- bits is greater than 63, the value of total -- used -- bits wraps back around to zero.
When total -- used is greater than 32 and less than or equal to 63, first flop bank 601 is loaded with new data. When total -- used is greater than or equal to zero and less than 32, the data steering logic loads second flop bank 602 with data.
Continuing with the previous example, the first 10 bit symbol is processed by first flop bank MUX 606 and loaded into barrel shifter 605, usedbits set to 10, total -- used set to 10, and total -- bits -- used set to 10. The next symbol may take 12 bits, in which case the system processes the 12 bit symbol using first flop bank MUX 606 and passes the data to barrel shifter 605. usedbits is set to 12, which is added to total -- used -- bits (10) in total -- used -- bits counter 603, yielding a total -- used of 22.
The next data acquired from RAM may be a large symbol, having 32 bits of length. Such a symbol spans both first flop 601 and second flop 602, from location 23 in first flop 601 through second flop 602 location 13. In such a situation, usedbits is 32, and the data is processed by first flop bank MUX 606 and second flop bank MUX 607 usedbits is set to 32, which is added to total used bits (22) in total used bits counter 603, yielding a total -- used of 54.
With a total -- used of 54, the system loads new data into first flop 601 and continues with second flop 602.
Barrel shifter 605 is a 32 bit register, and thus the addition of the last 32 bit segment of processed data would fill the barrel shifter 605. Hence the data from barrel shifter 605 is transferred out of barrel shifter 605 and into resultant data flop 608. The 32 bits from first flop bank MUX 606 and second flop bank MUX 607 pass to barrel shifter 605.
Continuing with the example, the next symbol may only take up one bit. In such a situation, used bits is one, which is added to total -- used -- bits (54) yielding a total -- used of 55. The system processes the bit in second flop bank MUX 607 and the processed bit passes to barrel shifter 605.
The next symbol may again be 32 in length, in which case data from the end of second flop 602 and the beginning of first flop 601 is processed and passed into the barrel shifter 605. usedbits is 32, which is added to total -- used -- bits (54), which sums to 87. However, the six bit size of the total -- used indicates a total of 23, i.e. the pointer in the barrel register 605 is beyond the current 64 bits of data and is 23 bits into the next 64 bits of data.
With a value in excess of 32 bits, the single bit residing in barrel shifter 605 passes to resultant data flop 608, and the 32 bits pass to barrel shifter 605. The system then sequentially steps through all remaining data to process and pass data in an efficient manner.
The operation of the process is illustrated graphically in FIG. 7. The first and second flop banks are loaded in step 701 and the system initialized in step 702. The system reads data in step 703 and determines total -- used in step 704. The system then determines whether total -- used -- bits is greater than 32 in step 705, and, if so, first flop bank is loaded with new data in step 706. Step 707 determines whether total -- used is greater than or equal to 0 and less than 32. If so, step 708 loads the second flop bank with data.
As long as usedbits is not equal to zero, steps 704 through 708 are repeated. If the CPU initializes the data steering logic in the middle of the operation, the process begins at step 701.
The advantage of this implementation is that it is hardware oriented and requires no interaction from a CPU or microcontroller. Only a single shift register is used, which provides significant area savings. The system obtains the benefits of using the shift register as a circular buffer in that the system uses total bits as a pointer into the shift register and loads shifted data into the resultant data register 608.
IDCT Processor/Algorithm
The TMCCORE 103 performs the IDCT transform using IDCT processor 107. The Inverse Discrete Cosine Transform is a basic tool used in signal processing. The IDCT processor 107 used in MBCORE 102 may be any form of general purpose tool which performs the IDCT function, but the preferred embodiment of such a design is presented in this section.
The application of the IDCT function described in this section is within a real time, high throughput multimedia digital signal processing chip, but alternate implementations can employ the features and functions presented herein to perform the inverse DCT function.
The implementation disclosed herein is IEEE compliant, and conforms with IEEE Draft Standard Specification for the Implementations of 8×8 Inverse Discrete Cosine Transform, P1180/D1, the entirety of which is incorporated herein by reference.
Generally, as illustrated in FIG. 1, the MBCORE 102 receives DCT data and initially processes symbols using the video bitstream symbol extractor 105 and subsequently performs the IDCT function using IDCT processor 107.
The system feeds DCT coefficients into IDCT processor 106 in a group of eight rows of eight columns. Each DCT coefficient is a 12 bit sign magnitude number with the most significant bit (MSB) being the sign bit. The IDCT processor 106 processes a macroblock comprising an 8×8 block of pixels in 64 cycles. After processing, the IDCT processor transmits a data stream of eight by eight blocks. Each output IDCT coefficient is a nine bit sign magnitude number also having the MSB as a sign bit.
The Inverse Discrete Cosine Transform is defined as: ##EQU1##
where i,j=0 . . . 7 is the pixel value, X(k,l), k,l=0 . . . 7 is the transformed DCT coefficient, x(i,j) is the final result, and ##EQU2##
Equation 1 is mathematically equivalent to the following matrix form: ##EQU3## where X Q (i,j)=QQ(i,j)X(j,i), QQ=Q * Q, where Q is a matrix and QQ is the product of matrix Q with itself. P from Equation 3 is as follows: ##EQU4## where Q is: ##EQU5## and I is a unitary diagonal identity matrix, a is 5.0273, b is 2.4142, c is 1.4966, and r is 0.7071.
The matrix representation of the IDCT greatly simplifies the operation of the IDCT processor 106, since each row of the P matrix has only four distinct entries, with one entry being 1. This simplification of the number of elements in the IDCT matrix means that in performing a matrix multiplication, the system only needs three multipliers instead of eight, the total number of elements in each row.
The system performs IDCT processing by performing multiplications as illustrated in FIG. 8. The IDCT processor 107 receives 12 bits of DCT data input in 2's complement format, and thus can range (with the sign bit) from -2048 to +2047. The first block 801 performs a sign change to convert to sign magnitude. If necessary, block 801 changes -2048 to -2047. This yields eleven bits of data and a data bit indicating sign. Second block 802 performs the function QX t Q, which uses 0+16 bits for QQ, yielding one sign bit and 20 additional bits. Block 802 produces a 27 bit word after the multiplication (11 bits multiplied by 16 bits), and only the 20 most significant bits are retained. Block 803 multiplies the results of block 802 with the elements of the P matrix, above. The P matrix is one sign bit per element and 15 bits per element, producing a 35 bit word. The system discards the most significant bit and the 14 least significant bits, leaving a total of 20 bits. The result of block 804 is therefore again a one bit sign and a 20 data bits.
Block 805 converts the sign magnitude to two's complement, yielding a 21 bit output. The system adds four blocks into each buffer, with the buffers having 22 bits each. Block 805 transmits all 22 bits. Block 806 performs a sign change to obtain QX t QP, and passes 22 bits with no carry to block 807.
Block 807 performs a matrix transpose of QX t QP, yielding (QX t QP) t . Block 807 passes this transpose data to block 808 which performs a twos complement to sign-magnitude, yielding a one bit sign and a 21 bit word. Block 809 clips the least significant bit, producing a one bit sign and a 20 bit word. This result passes to block 810, which multiplies the result by the P matrix, having a one bit sign and a 15 bit word. The multiplication of a 20 bit word with 1 bit sign by a 15 bit word with 1 bit sign yields a 35 bit word, and the system discards the two most significant bits and the 13 least significant bits, producing a 20 bit word with a 1 bit sign out of block 810. The result of block 810 is sign-magnitude converted back to 2's complement, producing a 21 bit result in block 811. Block 812 performs a similar function to block 805, and adds the four products into each buffer. The buffers have 22 bits each, and the output from block 812 is 22 bits. This data is passed to block 813, which performs a sign switch to obtain the elements of (QX t QP) t P. Output from block 813 is a 22 bit word, with no carry. Block 814 right shifts the data seven bits, with roundoff, and not a clipping. In other words, the data appears as follows:
SIGNxxxxxxxxxxxxxXYxxxxxx (22 bit word)
and is transformed by a seven bit shift in block 813 to:
SIGNxxxxxxxxxxxxxX.Yxxxxxx
Depending on the value of Y, block 814 rounds off the value to keep 15 bits. If Y is 1, block 814 increments the integer portion of the word by 1; if Y is 0, block 814 does not change the integer part of the word.
The result is a 15 bit word, which is passed to block 815. In block 815, if the 15 bit value is greater than 255, the block sets the value to 255. If the value is less than -256, it sets the value to -256. The resultant output from block 815 is the IDCT output, which is a 9 bit word from -256 to 255. This completes the transformation from a 12 bit DCT input having a value between -2048 and 2047, and a 9 bit inverse DCT output, having a value between -256 and 255.
The efficiencies for matrix multiplication are as follows. The four factors used which can fully define all elements of the QQ and P matrices are as follows: ##EQU6##
The parameters for all elements of the QQ and PP matrix are: ##EQU7##
For the P matrix, ##EQU8##
The entire IDCT is implemented in two stages. IDCT Stage 1, illustrated in FIG. 9, implements X Q P. The second stage, illustrated in FIG. 10, transposes the result and multiplies it by P again.
From FIG. 2, and as may be more fully appreciated from the illustrations of FIGS. 8 through 11, the TMCCORE 103 receives the DCT input, produces the matrix (QX t Q)P, or X Q P, in IDCT Stage 1 (i.e., from FIG. 8, completes through block 806) and stores the result in transpose RAM 923. IDCT Stage 2 performs the transpose of the result of IDCT Stage 1 and multiplies the result by P, completing the IDCT process and producing the IDCT output.
As may be appreciated from FIG. 9, the representation disclosed is highly similar to the flowchart of FIG. 8. From FIG. 9, IDCT Stage 1 pipeline 900 receives data from the IQ block in the form of the matrix X. The Q matrix is available from a row/column state machine in the IQ pipeline, depicted by state machine registers 902. The state machine registers 902 pass data from register 902c to QQ matrix block 903 which contains QQ matrix generator 904 and QQ matrix register 905. QQ data is passed to QX t Q block 901 which multiplies the 16 bit QQ matrix by the X block having one sign bit and 11 data bits in QX t Q multiplier 906 This multiplication is passed to QX t Q register 907, which transmits a one bit sign and a 20 bit word. QX t Q block 901 thereby performs the function of block 802. Output from register 902d is a column [2:0] which passes to P matrix block 908. P matrix block 908 comprises P matrix generator 909 which produces a sign bit and three fifteen bit words to P matrix register 910.
QX t Q block 901 passes the one bit sign and 20 bit word to (QX t Q)P block 911, which also receives the three fifteen bit words and one sign bit from P matrix block 908. (QX t Q)P block 911 performs the function illustrated in block 803 in three multiplier blocks 912a, 912b, and 912c. The results of these multiplications is passed to (QX t Q)P MUX 913, which also receives data from register 902e in the form row[2:0]. Data from register 902e also passes to read address generator 914, which produces a transpose RAM read address. The transpose RAM read address passes to transpose RAM 923 and to first write address register 915, which passes data to write address register 916. The write address from write address register 916 and the read address from read address generator 914 pass to transpose RAM 923, along with the P matrix read row/column generator state machine 1001, illustrated below. (QX t Q)P MUX 913 thus receives the output from the three multiplier blocks 912a, 912b, and 912c as well as the output from register 902e, and passes data to (QX t Q)P register 917, which passes the (QX t Q)P matrix in a one bit sign and 20 bit word therefrom. As in block 804, these four data transmissions from (QX t Q)P block 911 pass to matrix formatting block 918. Matrix formatting block 918 performs first the function illustrated in block 802 by converting sign-magnitude to two's complement in two's complement blocks 919a, 919b, 919c, and 919d. The values of these four blocks 919a-d are added to the current values held in transpose RAM 923 in summation blocks 920a, 920b, 920c, and 920d. The transpose RAM 923 value is provided via register 921. Transpose RAM 923 is made up of 4 eight bit by 88 bit values, and each 22 bit result from the four summation blocks 920a, 920b, 920c, and 920d pass to register 922 and subsequently to transpose RAM 923. This completes processing for IDCT Stage 1.
Processing for IDCT Stage 2 1000 is illustrated in FIG. 10. P matrix read row/column generator state machine 1001 receives a transpose RAM ready indication and provides row/column information for the current state to transpose RAM 923 and to a sequence of registers 1002a, 1002b, 1002c, 1002d, and 1002e. The information from 1002b passes to Stage 2 P matrix block 1003, comprising Stage 2 P matrix generator 1004 and P matrix register 1005, which yields the one bit sign and 15 bit word for the P matrix.
From transpose RAM 923, two of the 22 bit transpose RAM elements pass to transpose block 1006, wherein transpose MUX 1007 passes data to registers 1008a and 1008b, changes the sign from one register using sign change element 1009 and passes this changed sign with the original value from register 1008b through MUX 1010. The value from MUX 1010 is summed with the value held in register 1008a in summer 1011, which yields the transpose of QX t QP, a 22 bit word. Thus the value of the data passing from the output of summer 1011 is functionally equal to the value from block 807, i.e. (QX t QP) t . Two's complement/sign block 1012 performs the function of block 808, forming the two's complement to sign-magnitude. The LSB is clipped from the value in LSB clipping block 1013, and this clipped value is passed to register 1014, having a one bit sign and a 20 bit word.
The output from transpose block 1006 is multiplied by the P matrix as functionally illustrated in block 810. This multiplication occurs in Stage 2 P multiplication block 1015, specifically in multipliers 1016a, 1016b, and 1016c. This is summed with the output of register 1002c in MUX 1017 and passed to register 1018. This is a matrix multiplication which yields (QX t QP) t P. Conversion block 1019 converts this information, combines it with specific logic and stores the IDCT values. First two's blocks 1020a, 1020b, 1020c, and 1020d convert sign-magnitude to two's complement, as in block 811, and sum this in adders 1021a, 1021b, 1021c, and 1021d with current IDCT RAM 1024 values, which comprise four 22 bit words. The sum of the current IDCT RAM values and the corrected (QX t QP) t P values summed in adders 1021a-d pass to IDCT RAM 1024.
IDCT RAM 1024 differs from transpose RAM 923. IDCT RAM 1024 provides a hold and store place for the output of IDCT Stage 2 values, and comprises two 88 by 1 registers. Note that IDCT RAM 1024 feeds four 22 bit words back to adders 1021a-d , one word to each adder, and passes eight 22 bit words from IDCT Stage 2 1000.
RAM also utilizes values passed from register 1002d, i.e. the position of read/write elements or the state of the multiplication. Register 1002d passes data to read additional combined logic element 1022, which calculates and passes a read add indication and a write add indication to RAM to properly read and write data from adders 1021a-d.
Data also passes from register 1002d to register 1002e, which provides information to output trigger generator 1023, the result of which is passed to RAM as well as out of IDCT Stage 2 1000. The output from RAM is eight 22 bit words and the output from output trigger generator 1023. The result functionally corresponds to the output from block 812.
FIG. 11 illustrates the implementation which performs the final functions necessary for IDCT output and stores the values in appropriate positions in IDCT OUTPUT RAM 1115. Sign corrector 1101 receives the eight 22 bit words from IDCT Stage 2 1000 and multiplexes them using MUX 1102 to four 22 bit words passing across two lines. These values are summed in summer 1103, and subtracted in subtractor 1104 as illustrated in FIG. 11. The output from subtractor 1104 passes through register 1105 and reverse byte orderer 1107, and this set of 4 22 bit words passes along with the value from summer 1103 to MUX 1107, which passes data to register 1108. This sign corrector block produces an output functionally comparable to the output of block 813, essentially providing the elements of (QX t QP) t P. Shift/roundoff block 1109 takes the results from sign corrector 1101, converts two's complement to sign/magnitude in element 1110, shifts the value right seven places using shifters 1111a, 1111b, 1111c, and 1111d, rounds these values off using round off elements 1112a, 1112b, 1112c, and 1112d, and passes these to element 1113. The rounded off values from round off elements 1112a-d functionally correspond to the output from block 814. The value is limited between -256 and +255 in element 1113, the output of which is a 15 bit word passed to sign block 1114, which performs a conversion to two's complement and passes four nine bit words to IDCT OUTPUT RAM 1115.
Output from the Output Trigger Generator and the chroma/luma values from CBP Luma/Chroma determine the stage of completeness of the IDCT RAM OUTPUT. IDCT RAM address/IDCT Done indication generator 1116, as with elements 914, 915, and 916, as well as elements 1022 and 1023, are placekeepers or pointers used to keep track of the position of the various levels of RAM, including the current position and the completion of the individual tasks for various levels of processing, i.e. IDCT Stage 1 progress, IDCT Stage 2 progress, and completion of the Stages. It is recognized that any type of bookkeeping, maintenance, or pointing processing can generally maintain values and placement information for reading, writing, and providing current location and completion of task indications to blocks or elements within the system while still within the scope of the current invention. The purpose of these elements is to provide such a bookkeeping function.
IDCT RAM address/IDCT Done indication generator 1116 receives output trigger generator 1023 output trigger information and CBP Luma/Chroma indications and provides a write address and a Luma Done/Chroma Done IDCT indication, signifying, when appropriate, the receipt of all necessary luma/chroma values for the current macroblock.
The system writes IDCT information to IDCT OUTPUT RAM 1115, specifically the information passing from sign block 1114 to the appropriate location based on the write address received from IDCT RAM address/IDCT Done indication generator 1116. IDCT OUTPUT RAM 1115 is broken into Luma (Y0, Y1, Y2, and Y3) locations, and Chroma (Cb and Cr) locations. The values of IDCT OUTPUT RAM 1115 represent the complete and final IDCT outputs.
The design disclosed herein provides IDCT values at the rate of 64 cycles per second. The design stores two blocks worth of data in transpose RAM 923 between IDCT Stage 1 and IDCT Stage 2.
Motion Compensation
Motion compensation for the two frame store and letterbox scaling for MPEG decoding operates as follows.
For a 2×7 array of pixels, i.e. 14 pels, the numbering of pels is illustrated in FIG. 12.
The system performs a half-pel compensation. Half-pel compensation is compensating for a location between pixels, i.e. the motion is between pixel x and pixel y. When the system determines the data in FIG. 12 must be right half pel compensated, or shifted right one half pel, the system performs the operation(s) outlined below.
0'=(0+1)/2; if (0+1)mod 2==1, 0'=0'+1;
1'=(1+2)/2; if (1+2)mod 2==1, 1'=1'+1; . . .
5'=(5+6)/2; if (5+6)mod 2==1, 5'=5'+1.
When the system determines the data in FIG. 12 must be down half pel compensated, or shifted downward one half pel, the system performs the operation(s) outlined below.
0'=(0+7)/2; if (0+7)mod 2==1, 0'=0'+1;
1'=(1+8)/2; if (1+8)mod 2==1, 1'=1'+1; . . .
6'=(6+13)/2; if (6+13)mod 2==1, 6'=6'+1.
Alternately, the system may indicate the desired position is between four pels, or shifted horizontally one half pel and down one half pel. When the system determines the data in FIG. 12 must be right and down half pel compensated, or shifted right one half pel and down one half pel, the system performs the operation(s) outlined below.
0'=(0+1+7+8)/4; if (0+1+7+8)mod 4==1, 0'=0'+1;
1'=(1+2+8+9)/2; if (1+2+8+9)mod 4==1, 1'=1'+1.
The aforementioned logic is implemented as illustrated in FIG. 13. As may be appreciated, a right half pel shift may require the system to point to a position one half-pel outside the block. Thus the system must compensate for odd-pel shifting.
From FIG. 13, the motion compensation unit 1300 comprises horizontal half pel compensatory 1301 and vertical half pel compensator 1302, as well as four banks of 36 flops 1303a, 1303b, 1303c, and 1303d. Registers 1304a, 1304b, 1304c, 1304d, and 1304e contain motion compensation data having 32 bits of information. These registers pass the motion compensation data to horizontal compensation MUXes 1305a, 1305b, 1305c, and 1305d, as well as horizontal adders 1306a, 1306b, 1306c, and 1306d as illustrated in FIG. 13. For example, register 1304e passes motion compensation data to horizontal compensation MUX 1305d, which subsequently passes the information to horizontal adder 1306d and adds this value to the value received from register 1304d. Register 1304a passes data to adder 1306a but does not pass data to any of the horizontal compensation MUXes 1305a-d. This summation/MUX arrangement provides a means for carrying out the right half-pel compensation operations outlined above. The result of the horizontal half pel compensator 1301 is four summed values corresponding to the shift of data one half pel to the right for a row of data.
As a luma macroblock has dimensions of 16×16, movement of one half pel to the right produces, for the 16th element of a row, a shift outside the bounds of the 16×16 macroblock. Hence a right shift produces a 16×17 pixel macroblock, a vertical shift a 17×16 pixel macroblock, and a horizontal and vertical shift a 17 by 17 pixel macroblock. The additional space is called an odd pel.
The compensation scheme illustrated in FIG. 13 determines the necessity of compensation and thereby instructs the MUXes disclosed therein to compensate by adding one half pel to each pel position in the case of horizontal pixel compensation. Thus out of the 32 bits from reference logic, data for each pel may be shifted right one pel using the MUX/adder arrangement of the horizontal half pel compensator 1301.
Vertical pel compensation operates in the same manner. For each of the pels in a macroblock, the data is shifted downward one half pel according to the vertical compensation scheme outlined above. Vertical half pel compensator 1302 takes and sums results from the horizontal half pel compensator 1301 and receives data from the four banks of 36 flops 1303a, 1303b, 1303c, and 1303d. Data from horizontal half pel compensator 1301 passes to vertical adders 1308a, 1308b, 1308c, and 1308d along with MUXed data from the four banks of 36 flops 1303a, 1303b, 1303c, and 1303d.
In cases where vertical and horizontal half pel compensation are required, the four banks of 36 flops 1303a, 1303b, 1303c, and 1303d are used by the system to store the extra row of reference data expected for down half-pel compensation. This data storage in the four banks of 36 flops 1303a-d provides the capability to perform the computations illustrated above to vertically and horizontally shift the data one half pel. The result is transmitted to register 1309, which may then be B-picture compensated and transmitted to motion compensation output RAM 1311.
Reference data averaging may be necessary for B-pictures having backward and forward motion vectors, or with P pictures having a dual-prime prediction. Either function is accomplished within the B-picture compensator 1310.
Prediction may generally be either frame prediction, field prediction, or dual-prime. Frame pictures for half pel compensation appear as follows.
In frame prediction, the luma reference data pointed to by a motion vector contains either 16×16 (unshifted), 16×17 (right half-pel shifted), 17×16 (down half-pel shifted), or 17×17 (right and down half-pel shifted) data. The chroma component, either Cr or Cb, contains either 8×8 (unshifted), 8×9 (right half-pel shifted), 9×8 (down half-pel shifted) or 9×9 (right and down half-pel shifted) data.
In field prediction as well as dual-prime predictions, the luma reference data pointed to by a motion vector contains either 8×16 (unshifted), 8×17 (right half-pel shifted), 9×16 (down half-pel shifted) or 9×17 (down and right half pel shifted) data. The chroma reference data, either Cr or Cb, contains either 4×8 (unshifted), 4×9 (right half-pel shifted), 5×8 (down half-pel shifted) or 5×9 (right and down half-pel shifted) data.
Field pictures for half-pel compensation may utilize field prediction, 16×8 prediction, or dual-prime. Field prediction and dual-prime prediction are identical to frame prediction in frame pictures, i.e. the luma and chroma references are as outlined above with respect to frame prediction (16×16, 16×17, 17×16, or 17×17 luma, 8×8, 8×9, 9×8, or 9×9 chroma). 16×8 prediction is identical to field prediction in frame pictures, i.e., luma and chroma are identical as outlined above with respect to field prediction (8×16, 8×17, 9×16, or 9×17 luma, 4×8, 4×9, 5×8, or 5×9 chroma).
The motion compensation unit 1300 accepts reference data 32 bits (4 pels) at a time while accepting odd pel data one pel at a time on the odd pel interface, The system ships luma reference data in units of 8×16 and chroma reference data in units of 4×8. Luma reference data is transferred before chroma reference data, and Cb chroma is shipped before Cr chroma.
In accordance with the motion compensation unit 1300 of FIG. 13, transfer of luma and chroma data occurs as follows.
For luma data, assuming that luma reference data is represented by luma [8:0] [16:0], or that data requires both right and down half-pel compensation. On a cycle by cycle basis, luma data is transferred as follows using motion compensation unit 1300:
______________________________________Cycle Reference Data Odd-Pel Data______________________________________1 Luma [0] [12:15] Luma [0] [17]2 Luma [0] [8:11]3 Luma [0] [4:7]4 Luma [0] [0:3]5 Luma [1] [12:15] Luma [1] [16]6 Luma [1] [8:11]7 Luma [1] [4:7]8 Luma [1] [0:3]. . . . . . . . .33 Luma [8] [12:15] Luma [8] [16]34 Luma [8] [8:11]35 Luma [8] [4:7]36 Luma [8] [0:3]______________________________________
For chroma reference data represented by Chroma [4:0][8:0]. The motion compensation unit 1300 transfers data on a cycle by cycle basis as follows:
______________________________________Cycle Reference Data Odd-Pel Data______________________________________1 Chroma [0] [4:7] Chroma [0] [8]2 Chroma [0] [0:3]3 Chroma [1] [4:7] Chroma [1] [8]4 Chroma [1] [0:3]. . . . . . . . .9 Chroma [4] [4:7] Chroma [4] [8]10 Chroma [4] [0:3]______________________________________
Data expected by motion compensation units for the combinations of picture type, prediction type, and pel compensation are as follows:
______________________________________ Data fetched byPicture Prediction Pel vector (in pels)Type Type Compensation Luma/Chroma______________________________________Frame Frame None 16 × 16/8 × 8 Right 16 × 17/8 × 9 Vertical 17 × 16/9 × 8 Right/Vert. 17 × 17/9 × 9 Field None 8 × 16/4 × 8 Right 8 × 17/4 × 9 Vertical 9 × 16/5 × 8 Right/Vert. 9 × 17/5 × 9 Dual-Prime None 8 × 16/4 × 8 Right 8 × 17/4 × 9 Vertical 9 × 16/5 × 8 Right/Vert. 9 × 17/5 × 9Field Field None 16 × 16/8 × 8 Right 16 × 17/8 × 9 Vertical 17 × 16/9 × 8 Right/Vert. 17 × 17/9 × 9 16 × 8 None 8 × 16/4 × 8 Right 8 × 17/4 × 9 Vertical 9 × 16/5 × 8 Right/Vert. 9 × 17/5 × 9 Dual-Prime None 16 × 16/8 × 8 Right 16 × 17/8 × 9 Vertical 17 × 16/9 × 8 Right/Vert. 17 × 17/9 × 9______________________________________
Reference data transfer to the TMCCORE 103 occurs as follows.
______________________________________Reference Motion Transfer Order toVector Data Motion Compensation Unit 1300______________________________________Luma Data17 × 17 1) 9 × 17 2) 8 × 1716 × 16 1) 8 × 16 2) 8 × 1617 × 16 1) 9 × 16 2) 8 × 1616 × 17 1) 8 × 17 2) 8 × 17 8 × 16 8 × 16 9 × 16 9 × 16 8 × 17 8 × 17 9 × 17 9 × 17Chroma Data9 × 9 1) 5 × 9 2) 4 × 98 × 9 1) 4 × 9 2) 4 × 99 × 8 1) 5 × 9 2) 4 × 98 × 8 1) 4 × 8 2) 4 × 84 × 8 4 × 84 × 9 4 × 95 × 8 5 × 85 × 9 5 × 9______________________________________
The maximum amount of reference data (in bytes) that the system must fetch for any macroblock conforming to the 4:2:0 format occurs in a frame picture/field prediction/B-picture, a field picture/16×8 prediction/B-picture, or a frame picture/dual prime. The amount of luma reference data expected, excluding odd pel data, is 4 * 9 * 16 or 576 bytes of data. The amount of luma reference data (for both Chroma blue and Chroma red, excluding half-pel data, is 2 * 4 * 5 * 8 or 320 bytes.
Data may be processed by the motion compensation unit 1300 at a rate of 4 pels per cycle. The total number of cycles required to process the data is 576+320/4, or 224 cycles. This does not include odd pel data which is transferred on a separate bus not shared with the main data bus.
While the invention has been described in connection with specific embodiments thereof, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptations of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within known and customary practice within the art to which the invention pertains.
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A system and method for decoding an MPEG video bitstream comprises, comprising a macroblock core (MBCORE) which processes video bitstream data and computes discrete cosine transform data and a parser which parses the video bitstream macroblocks into multiple data blocks used in subsequent stages of decoding. fixed length data words comprising variable length objects using a novel rotating register arrangement. A multistage transformation/motion compensation core (TMCCORE) uses intermediate memory. The IDCT first stage has the ability to operate on a first data block while the second stage simultaneously operates on a second data block. The TMCCORE receives the discrete cosine transform data from the MBCORE and calculates and reconstructs a frame therefrom using motion compensation. The MBCORE can operate on data from a first macroblock while the TMCCORE simultaneously operates on data from a second macroblock. The TMCCORE reconstructs the picture from one macroblock while the IDCT first and second stages simultaneously operate on data from the macroblock. Additionally, a horizontal and vertical half pixel compensation arrangement is included which has multiple adders and multiplexers.
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FIELD OF THE INVENTION
[0001] The invention generally relates to compositions, articles and methods for scavenging by-products of an oxygen scavenging reaction.
BACKGROUND OF THE INVENTION
[0002] It is well known that limiting the exposure of an oxygen-sensitive product to oxygen maintains and enhances the quality and “shelf-life” of the product. In the food packaging industry, several means for regulating oxygen exposure have already been developed.
[0003] These means include modified atmosphere packaging (MAP) for modifying the interior environment of a package; gas flushing; vacuum packaging; vacuum packaging combined with the use of oxygen barrier packaging materials; etc. Oxygen barrier films and laminates reduce or retard oxygen permeation from the outside environment into the package interior.
[0004] Another method currently being used is through “active packaging.” The inclusion of oxygen scavengers within the cavity or interior of the package is one form of active packaging. Typically, such oxygen scavengers are in the form of sachets which contain a composition which scavenges the oxygen through chemical reactions. One type of sachet contains iron compositions which oxidize. Another type of sachet contains unsaturated fatty acid salts on a particulate adsorbent. Yet another type of sachet contains metal/polyamide complex.
[0005] One disadvantage of sachets is the need for additional packaging operations to add the sachet to each package. A further disadvantage arising from the use of some sachets is that certain atmospheric conditions (e.g., high humidity, low CO 2 level) in the package are required in order for scavenging to occur at an adequate rate.
[0006] Another means for limiting the exposure to oxygen involves incorporating an oxygen scavenger into the packaging structure itself. This achieves a more uniform scavenging effect throughout the package. This may be specially important where there is restricted air circulation inside the package. In addition, such incorporation can provide a means of intercepting and scavenging oxygen as it passes through the walls of the package (herein referred to as an “active oxygen barrier”), thereby maintaining the lowest possible oxygen level throughout the package.
[0007] One attempt to prepare an oxygen-scavenging wall involves the incorporation of inorganic powders and/or salts. However, incorporation of these powders and/or salts causes degradation of the wall's transparency and mechanical properties such as tear strength. In addition, these compounds can lead to processing difficulties, especially in the fabrication of thin films, or thin layers within a film structure. Even further, the scavenging rates for walls containing these compounds are unsuitable for some commercial oxygen-scavenging applications, e.g. such as those in which sachets are employed.
[0008] Other efforts have been directed to incorporating a metal catalyst-polyamide oxygen scavenging system into the package wall. However, this system does not exhibit oxygen scavenging at a commercially feasible rate.
[0009] Oxygen scavengers suitable for commercial use in films of the present invention are disclosed in U.S. Pat. No. 5,350,622, and a method of initiating oxygen scavenging generally is disclosed in U.S. Pat. No 5,211,875. Both applications are incorporated herein by reference in their entirety. According to U.S. Pat. No. 5,350,622, oxygen scavengers are made of an ethylenically unsaturated hydrocarbon and transition metal catalyst. The preferred ethylenically unsaturated hydrocarbon may be either substituted or unsubstituted. As defined herein, an unsubstituted ethylenically unsaturated hydrocarbon is any compound which possesses at least one aliphatic carbon-carbon double bond and comprises 100% by weight carbon and hydrogen. A substituted ethylenically unsaturated hydrocarbon is defined herein as an ethylenically unsaturated hydrocarbon which possesses at least one aliphatic carbon-carbon double bond and comprises about 50% - 99% by weight carbon and hydrogen. Preferable substituted or unsubstituted ethylenically unsaturated hydrocarbons are those having two or more ethylenically unsaturated groups per molecule. More preferably, it is a polymeric compound having three or more ethylenically unsaturated groups and a molecular weight equal to or greater than 1,000 weight average molecular weight.
[0010] Preferred examples of unsubstituted ethylenically unsaturated hydrocarbons include, but are not limited to, diene polymers such as polyisoprene, (e.g., trans-polyisoprene) and copolymers thereof, cis and trans 1,4-polybutadiene, 1,2-polybutadienes, (which are defined as those polybutadienes possessing greater than or equal to 50% 1,2 microstructure), and copolymers thereof, such as styrene-butadiene copolymer. Such hydrocarbons also include polymeric compounds such as polypentenamer, polyoctenamer, and other polymers prepared by cyclic olefin metathesis; diene oligomers such as squalene; and polymers or copolymers with unsaturation derived from dicyclopentadiene, norbornadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 4-vinylcyclohexene, or other monomers containing more than one carbon-carbon double bond (conjugated or non-conjugated).
[0011] Preferred substituted ethylenically unsaturated hydrocarbons include, but are not limited to, those with oxygen-containing moieties, such as esters, carboxylic acids, aldehydes, ethers, ketones, alcohols, peroxides, and/or hydroperoxides. Specific examples of such hydrocarbons include, but are not limited to, condensation polymers such as polyesters derived from monomers containing carbon-carbon double bonds, and unsaturated fatty acids such as oleic, ricinoleic, dehydrated ricinoleic, and linoleic acids and derivatives thereof, e.g. esters. Such hydrocarbons also include polymers or copolymers derived from (meth)allyl (meth)acrylates. Suitable oxygen scavenging polymers can be made by trans-esterification. Such polymers are disclosed in WO 95/02616, incorporated herein by reference as if set forth in full. The composition used may also comprise a mixture of two or more of the substituted or unsubstituted ethylenically unsaturated hydrocarbons described above. While a weight average molecular weight of 1,000 or more is preferred, an ethylenically unsaturated hydrocarbon having a lower molecular weight is usable, provided it is blended with a film-forming polymer or blend of polymers.
[0012] As will also be evident, ethylenically unsaturated hydrocarbons which are appropriate for forming solid transparent layers at room temperature are preferred for scavenging oxygen in the packaging articles described above. For most applications where transparency is necessary, a layer which allows at least 50% transmission of visible light is preferred.
[0013] When making transparent oxygen-scavenging layers according to this invention, 1,2-polybutadiene is especially preferred for use at room temperature. For instance, 1,2-polybutadiene can exhibit transparency, mechanical properties and processing characteristics similar to those of polyethylene. In addition, this polymer is found to retain its transparency and mechanical integrity even after most or all of its oxygen capacity has been consumed, and even when little or no diluent resin is present. Even further, 1,2-polybutadiene exhibits a relatively high oxygen capacity and, once it has begun to scavenge, it exhibits a relatively high scavenging rate as well.
[0014] When oxygen scavenging at low temperatures is desired, 1,4-polybutadiene, and copolymers of styrene with butadiene, and styrene with isoprene are especially preferred. Such compositions are disclosed in U.S. Pat. No. 5,310,497 issued to Speer et al. on May 10, 1994 and incorporated herein by reference as if set forth in full. In many cases it may be desirable to blend the aforementioned polymers with a polymer or copolymer of ethylene.
[0015] Other oxygen scavengers which can be used in connection with this invention are disclosed in U.S. Pat. Nos. 5,075,362 (Hofeldt et al.), 5,106,886 (Hofeldt et al.), 5,204,389 (Hofeldt et al.), and 5,227,411 (Hofeldt et al.), all incorporated by reference herein in their entirety. These oxygen scavengers include ascorbates or isoascorbates or mixtures thereof with each other or with a sulfite, often sodium sulfite.
[0016] Still other oxygen scavengers which can be used in connection with this invention are disclosed in PCT patent publications WO 91/17044 (Zapata Industries) and WO94/09084 (Aquanautics Corporation), both incorporated by reference herein in their entirety. These oxygen scavengers include an ascorbate with a transition metal catalyst, the catalyst being a simple metal or salt or a compound, complex or chelate of the transition metal; or a transition metal complex or chelate of a polycarboxylic or salicylic acid or polyamine, optionally with a reducing agent such as ascorbate, where the transition metal complex or chelate acts primarily as an oxygen scavenging composition.
[0017] Yet other oxygen scavengers which can be used in connection with this invention are disclosed in PCT patent publication WO 94/12590 (Commonwealth Scientific and Industrial Research Organisation), incorporated by reference herein in its entirety. These oxygen scavengers include at least one reducible organic compound which is reduced under predetermined conditions, the reduced form of the compound being oxidizable by molecular oxygen, wherein the reduction and/or subsequent oxidation of the organic compound occurs independent of the presence of a transition metal catalyst. The reducible organic compound is preferably a quinone, a photoreducible dye, or a carbonyl compound which has absorbence in the UV spectrum.
[0018] Sulfites, alkali metal salts of sulphites, and tannins, are also contemplated as oxygen scavenging compounds.
[0019] As indicated above, the ethylenically unsaturated hydrocarbon is combined with a transition metal catalyst. While not being bound by any particular theory, the inventors observe that suitable metal catalysts are those which can readily interconvert between at least two oxidation states. See Sheldon, R. A.; Kochi, J. K.; “Metal-Catalyzed Oxidations of Organic Compounds” Academic Press, New York 1981.
[0020] Preferably, the catalyst is in the form of a transition metal salt, with the metal selected from the first, second or third transition series of the Periodic Table. Suitable metals include, but are not limited to, manganese II or III, iron II or III, cobalt II or III, nickel II or III, copper I or II, rhodium II, III or IV, and ruthenium II or III. The oxidation state of the metal when introduced is not necessarily that of the active form. The metal is preferably iron, nickel or copper, more preferably manganese and most preferably cobalt. Suitable counterions for the metal include, but are not limited to, chloride, acetate, stearate, palmitate, caprylate, linoleate, tallate, 2-ethylhexanoate, neodecanoate, oleate or naphthenate. Particularly preferable salts include cobalt (II) 2-ethylhexanoate and cobalt (II) neodecanoate. The metal salt may also be an ionomer, in which case a polymeric counterion is employed. Such ionomers are well known in the art.
[0021] The ethylenically unsaturated hydrocarbon and transition metal catalyst can be further combined with one or more polymeric diluents, such as thermoplastic polymers which are typically used to form film layers in plastic packaging articles. In the manufacture of certain packaging articles well known thermosets can also be used as the polymeric diluent.
[0022] Polymers which can be used as the diluent include, but are not limited to, polyethylene terephthalate (PET), polyethylene, low or very low density polyethylene, ultra-low density polyethylene, linear low density polyethylene, polypropylene, polyvinyl chloride, polystyrene, and ethylene copolymers such as ethylene-vinyl acetate, ethylene-alkyl (meth)acrylates, ethylene-(meth)acrylic acid and ethylene-(meth)acrylic acid ionomers. Blends of different diluents may also be used. However, as indicated above, the selection of the polymeric diluent largely depends on the article to be manufactured and the end use. Such selection factors are well known in the art.
[0023] Further additives can also be included in the composition to impart properties desired for the particular article being manufactured. Such additives include, but are not necessarily limited to, fillers, pigments, dyestuffs, antioxidants, stabilizers, processing aids, plasticizers, fire retardants, anti-fog agents, etc.
[0024] The mixing of the components listed above is preferably accomplished by melt-blending at a temperature in the range of 50° C. to 300° C. However alternatives such as the use of a solvent followed by evaporation may also be employed. The blending may immediately precede the formation of the finished article or preform or precede the formation of a feedstock or masterbatch for later use in the production of finished packaging articles.
[0025] Although these technologies offers great potential in packaging applications, it has been found that oxygen scavenging structures can sometimes generate reaction byproducts which can affect the taste and smell of the packaged material (i.e. organoleptic properties), or raise food regulatory issues. These by-products can include acids, aldehydes and ketones.
[0026] The inventors have found that this problem can be minimized by the use of zeolites (such as organophilic zeolites) which absorb odor-causing reaction byproducts. The zeolites can be incorporated into one or more layers of a multilayer film or container which includes an oxygen scavenging layer. However, one of ordinary skill in the art will readily recognize that the present invention is applicable to any oxygen scavenging system that produces by-products such as acids, aldehydes, and ketones.
DEFINITIONS
[0027] “Film” (F) herein means a film, laminate, sheet, web, coating, or the like which can be used to package a product.
[0028] “Zeolite” herein refers to molecular sieves, including aluminophosphates and aluminosilicates with a framework structure enclosing cavities occupied by large ions and/or water molecules, both of which have considerable freedom of movement permitting ion exchange and reversible dehydration. The framework may also contain other cations such as Mn, Ti, Co, and Fe. An example of such materials are the titanosilicate and titanoaluminosilicate molecular sieves. Unlike amorphous materials, these crystalline structures contain voids of discrete size. A typical naturally occurring zeolite is the mineral faujasite with formula
Na 13 Ca 11 Mg 9 K 2 Al 55 Si 137 O 384 .235H 2 O.
[0029] Ammonium and alkylammonium cations may be incorporated in synthetic zeolites, e.g. NH 4 , CH 3 NH 3 , (CH 3 ) 2 NH 2 , (CH 3 ) 3 NH, and (CH 3 ) 4 N. Some zeolites have frameworks of linked truncated octahedra (Beta-cages) characteristic of the structure of sodalite. Numerous synthetic zeolites are available.
[0030] “Oxygen scavenger” (OS) and the like herein means a composition, article or the like which consumes, depletes or reacts with oxygen from a given environment.
[0031] “Actinic radiation” and the like herein means any form of radiation, such as ultraviolet radiation or electron beam irradiation, disclosed in U.S. Pat. No. 5,211,875 (Speer et al.).
[0032] “Polymer” and the like herein means a homopolymer, but also copolymers thereof, including bispolymers, terpolymers, etc.
[0033] “Ethylene alpha-olefin copolymer” and the like herein means such heterogeneous materials as linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE) and very low and ultra low density polyethylene (VLDPE and ULDPE); and homogeneous polymers such as metallocene catalyzed polymers such as EXACT (™) materials supplied by Exxon, and TAFMER (™) materials supplied by Mitsui Petrochemical Corporation. These materials generally include copolymers of ethylene with one or more comonomers selected from C 4 to C 10 alpha-olefins such as butene-1 (i.e., 1-butene), hexene-1, octene-1, etc. in which the molecules of the copolymers comprise long chains with relatively few side chain branches or cross-linked structures. This molecular structure is to be contrasted with conventional low or medium density polyethylenes which are more highly branched than their respective counterparts. Other ethylene/alpha-olefin copolymers, such as the long chain branched homogeneous ethylene/alpha-olefin copolymers available from the Dow Chemical Company, known as AFFINITY (™) resins, are also included as another type of ethylene alpha-olefin copolymer useful in the present invention.
[0034] As used herein, the term “polyamide” refers to polymers having amide linkages along the molecular chain, and preferably to synthetic polyamides such as nylons. Furthermore, such term encompasses both polymers comprising repeating units derived from monomers, such as caprolactam, which polymerize to form a polyamide, as well as copolymers of two or more amide monomers, including nylon terpolymers, also referred to generally as “copolyamides” herein.
[0035] “LLDPE” herein means linear low density polyethylene, which is an ethylene alpha olefin copolymer.
[0036] “EVOH” herein means ethylene vinyl alcohol copolymer.
[0037] “EVA” herein means ethylene vinyl acetate copolymer.
SUMMARY OF THE INVENTION
[0038] In one aspect of the invention, an article of manufacture comprises an oxygen scavenger and a zeolite.
[0039] In a second aspect of the invention, a package comprises an article and a container into which the oxygen sensitive article is disposed, the container including a component comprising an oxygen scavenger and a zeolite.
[0040] In a third aspect of the invention, a method of making an article of manufacture having reduced migration of by-products of an oxygen scavenging reaction comprises providing an article comprising an oxygen scavenger and a zeolite and exposing the article to actinic radiation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The invention may be further understood with reference to the drawings wherein FIGS. 1 through 5 are schematic cross-sections of various embodiments of a film of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] The invention can be used to make various articles of manufacture, compounds, compositions of matter, coatings, etc. Two preferred forms are sealing compounds, and flexible films, both useful in packaging of food and non-food products.
[0043] It is known to use sealing compounds in the manufacture of gaskets for the rigid container market. Large, wide diameter gaskets are typically made using a liquid plastisol. This plastisol is a highly viscous, liquid suspension of polymer particles in a plasticizer. In the manufacture of metal or plastic caps, lids, and the like, this liquid plastisol is applied to the annulus of a container such as ajar, and the container with the applied plastisol is “fluxed” in an oven to solidify the plastisol into a gasket. The result is a gasket formed around the annulus of the container.
[0044] Smaller gaskets are typically made for use in beer crowns in bottles. A polymer melt is applied by cold molding to the entire inner surface of the crown. Both PVC and other polymers are used in this application.
[0045] Discs for plastic caps are typically made by taking a ribbon of gasket material and making discs, and inserting the discs into the plastic cap.
[0046] In all of these applications, the use of an oxygen scavenger and zeolite beneficially provides removal of oxygen from the interior environment of the container, while controlling undesirable by-products of the oxygen scavenging reaction.
[0047] Thus, a gasket includes a polymeric composition, an oxygen scavenger, and a zeolite. The gasket adheres a metal or plastic lid or closure to a rigid or semi-rigid container, thus sealing the lid or closure to the container.
[0048] Referring to FIG. 1, a multilayer film 10 is shown, having layer 12 and layer 14 .
[0049] [0049]FIG. 2 shows a multilayer film with layers 12 , 14 , and 16 . Layers 12 , 14 , and 16 are preferably polymeric.
[0050] Layer 12 comprises a zeolite. Preferred materials are the molecular sieves of the type disclosed in U.S. Pat. No. 4,795,482 (Gioffre et al.), incorporated herein by reference in its entirety. Also useful in the present invention are zeolites supplied by the Davison division of W. R. Grace & Co.-Conn. Preferred particle sizes for zeolites used in the present invention are between 0.1 and 10 micrometers, and more preferably between 0.5 and 3 micrometers.
[0051] Layer 14 comprises an oxygen scavenger, preferably a polymeric oxygen scavenger, more preferably one of the materials described above.
[0052] Layer 16 comprises an oxygen barrier material, such as ethylene vinyl alcohol copolymer (EVOH), Saran (vinylidene chloride copolymer), polyester, polyamide, metal, silica coating, etc.
[0053] [0053]FIG. 3 shows a laminated film in which a three layer film is adhered to a second film. Layers 32 , 34 , and 36 correspond functionally and compositionally to 12 , 14 , and 16 respectively of FIG. 2, and layer 38 is an intermediate layer which can comprise any polymeric material such as polyolefin, more preferably ethylenic polymers such as ethylene/alpha-olefin and ethylene/unsaturated ester copolymers, more preferably ethylene/vinyl acetate copolymer. Layer 31 represents a conventional adhesive such as polyurethane adhesive. Comparative 2 in Table 6 exemplifies the laminated film of FIG. 3.
[0054] [0054]FIG. 4 shows a laminated film in which a four layer film is adhered to a second film. Layers 42 , 44 , 46 and 48 correspond functionally and compositionally to layers 32 , 34 , 36 and 38 respectively of FIG. 3. Layer 49 is an innermost heat sealable layer which can comprise any polymeric material such as polyolefin, more preferably ethylenic polymers such as ethylene/alpha-olefin and ethyene/unsaturated ester copolymers, such as ethylene vinyl acetate copolymer. Layer 46 provides oxygen barrier to the film structure, and adheres to layer 48 by means of conventional adhesive 41 . This adhesive corresponds to layer 31 of FIG. 3, and is shown simply as a thickened line. Examples 2 and 3 of Table 6 exemplify the laminated film of FIG. 4.
[0055] [0055]FIG. 5 shows a nine layer film. Example 1 and Comparative 1 in Table 2 exemplify the film of FIG. 5.
[0056] Layer 57 is an abuse-resistant layer useful as an outermost layer of a film when used in a packaging application.
[0057] Layers 54 and 56 correspond functionally and compositionally to layers 14 and 16 respectively of FIGS. 2 and 3, as well as to layers 44 and 46 respectively of FIG. 4.
[0058] Layers 52 , 53 , 58 and 59 comprise an adhesive. The adhesive is preferably polymeric, more preferably acid or acid anhydride-grafted polyolefins. In addition, these layers can comprise a zeolite.
[0059] Layer 55 comprises a heat resistant material. This can be any suitable polymeric material, preferably an amide polymer such as nylon 6 , or a polyester such as polyethylene terephthalate.
[0060] Layer 51 comprises a heat sealable material. This can be any suitable polymeric material, preferably an olefinic polymer such as an ethylenic polymer, more preferably an ethylene alpha olefin copolymer. In addition, layer 51 can further comprise a zeolite.
[0061] The invention may be further understood by reference to the examples shown below. Table 1 identifies the materials used in the examples. The remaining tables describe the films made with these materials, and organoleptic or migration data resulting from testing some of these films.
TABLE 1 MATERIAL TRADENAME SOURCE DESCRIPTION PE 1 Dowlex ™ 3010 Dow LLDPE, an ethylene/1- octene copolymer with a density of 0.921 gm/cc PE 2 Dowlex ™ 2244 A Dow LLDPE, an ethylene/1- octene copolymer with a density of 0.916 gm/cc PE 3 Poly-eth 1017 Chevron low density polyethylene PE 4 AC-9A Allied polyethylene powder AB 1 10,075 ACP Sy- Tecknor 89.8% low density poly- loid ™ antiblock Color ethylene (Exxon LD concentrate 203.48) + 10% synthetic amorphous silica (Syloid ™ 74X6500 from Davison Chemical) + 0.2% calcium stearate PP 1 Escorene Exxon polypropylene PP292.E1 Z 1 10414-12 zeolite Colortech masterbatch of 80% concentrate LLDPE and 20% UOP Abscents ® 3000 zeolite Z 2 10417-12 zeolite Colortech masterbatch of 80% concentrate LLDPE and 20% UOP Abscents ® 2000 zeolite Z 3 USY zeolite Grace zeolite Davison Z 4 ZSM-5 zeolite Grace zeolite Davison Z 5 ZN-1 Grace zeolite Davison Z 6 X5297H Engelhard titanium silicate zeolite AD 1 Plexar ™ 107 Quantum anhydride-grafted EVA AD 2 Adcote 530 and Morton mixture of silane, isocy- Coreactant 9L23 Inter- anate, glycol, and alkyl national acetate PA 1 Ultramid ™ KR BASF nylon 6 4407-F (polycaprolactam) OB 1 LC-H101BD Evalca ethylene/vinyl alcohol copolymer with 38 mole % ethylene OS 1 RB-830 JSR 1,2-polybutadiene OS 2 VISTALON ™ Exxon ethylene-propylene-diene 3708 terpolymer OS 3 VECTOR ™ 8508- Dexco styrene/butadiene copoly- D mer with 30% by weight of the styrene comonom- er, and 70% by weight of the butadiene comonomer EV 1 MU-763 Quantum ethylene/vinyl acetate copolymer EV 2 PE 1375 Rexene ethylene/vinyl acetate copolymer with 3.6 wt. % vinyl acetate comonomer EV 3 LD-318.92 Exxon ethylene/vinyl acetate copolymer with 9 wt. % vinyl acetate comonomer EB 1 Lotryl 30BA02 Atochem ethylene/butyl acrylate copolymer with 30 wt. % butyl acrylate copolymer PI 1 benzophenone Sartomer photoinitiator PI 2 benzoylbiphenyl — photoinitiator TC 1 TENCEM ™ 170 OMG cobalt neodecanoate, a transition metal catalyst TC 2 cobalt oleate Shepherd a transition metal catalyst F 1 50m-44 Mylar ™ DuPont Saran-coated polyeth- ylene terephthalate film
[0062] Certain materials were blended together for some of the film structures, and these blends are identified as follows:
PEB 1 =90% PE 1 +10% AB 1 .
PEB 2 =90% PE 1 +10% PEB 3 .
PEB 3 =80% PE 3 +20% PE 4 .
PPB 1 =60% PP 1 +40% EB 1 .
PPB 2 =40% PP 1 +60% EB 1 .
OSB 1 =76.5% OS 1 +13.5% OS 2 +9.2% EV 1 +0.5% PI 1 +0.3% TC 1 .
OSB 2 =50% OS 3 +40% PE 3 +8.54% EV 1 +0.90% TC 1 +0.50% PI 1 +0.05% calcium oxide+ 0.01% antioxidant (Irganox 1076).
OSB 3 =60% OS 3 +38.83% EV 3 +1.06% TC 2 +0.10% PI 2 +0.01% antioxidant (Irganox 1076).
OSB 4 =40% OS 3 +58.83% EV 3 +1.06% TC 2 +0.10% PI 2 +0.01% antioxidant (Irganox 1076).
ZB 1 =87% PE 1 +10% AB 1 +3% Z 1 .
ZB 2 =90% PE 2 +10% Z 1 .
ZB 3 =90% PE 2 +10% Z 2 .
ZB 4 =90% PE 2 +6% PE 3 +2% PE 4 +1% Z 3 +1% Z 4
ZB 5 =80% PE 2 +20% Z 2 .
ZB 6 =80% PE 3 +20% Z 2 .
[0063] In Table 2, a nine-layer film structure in accordance with the invention, and a comparative film, are disclosed. These were each made by coextrusion of the layers.
TABLE 2 EXAMPLE STRUCTURE 1 PEB 1 /AD 4 /OB 1 /AD 4 /OSB 1 /AD 4 /PA 1 /AD 4 /ZB 2 COMP. 1 PEB 1 /AD 4 /OB 1 /AD 4 /OSB 1 /AD 4 /PA 1 /AD 4 /PEB 1
[0064] The target (and approximate actual) gauge (in mils) of each layer of the nine-layer film is shown below. Layer 9 would preferably form the food or product contact layer in a typical packaging application.
layer layer layer layer layer layer layer layer layer 1 2 3 4 5 6 7 8 9 1.35 0.20 0.50 0.20 0.50 0.20 1.00 0.20 1.35
[0065] The films of Example 1 and Comparative 1 were subjected to food law migration tests to evaluate whether zeolites could reduce the concentration of extractables. The films were triggered by ultraviolet light according to the procedure disclosed in U.S. Pat. No 5,211,875. The films were converted into 280 cm 2 pouches and the pouches were filled with a food simulant. The filled pouches were then retorted at 100° C. for 30 minutes and stored at 50° C. for 10 days. The food simulant was decanted from the pouches and analyzed. Table 3 shows a list of potential extractables. Table 4 shows the concentration of the same extractables, where the films were extracted with 8% ethanol solution as the food simulant. Table 5 shows the concentration of the same extractables, where the films were extracted with water as the food simulant. In both Tables 4 and 5, the concentration of each extractable is in units of nanograms/milliliter. Zeolites can reduce the concentration of certain extractables which could cause regulatory issues.
TABLE 3 ABBREVIATION DESCRIPTION E 1 benzophenone E 2 triphenyl phosphine oxide E 3 Permanax ™ WSP (antioxidant)* E 4 dilauryl thiodipropionate E 5 methyl formate E 6 ethyl formate E 7 methanol E 8 formaldehyde E 9 acetaldehyde E 10 acetone E 11 acrolein (2-propenal) E 12 propanal
[0066] [0066] TABLE 4 EX. E 1 E 2 E 3 E 4 E 5 E 6 E 7 E 8 E 9 E 10 1 21 21 <10 <5 <600 <300 3,310 1,400 6,700 100 COMP. 1 <20 40 <10 <5 <600 <300 2,960 1,600 7,800 80
[0067] [0067] TABLE 5 EX. E 1 E 2 E 3 E 4 E 5 E 6 E 7 E 8 E 9 E 10 1 22 13 <10 <5 <600 <300 <600 320 780 50 COMP. 1 21 16 <10 <5 <600 <300 <600 310 730 50
[0068] In Table 6, two five-layer laminate structures in accordance with the invention, and one comparative four-layer laminate structure, are disclosed. The two five-layer structures were each made by laminating a coextruded four-layer film, using a conventional adhesive, to a second film (=layer 5 ). The comparative structure was made by laminating a coextruded three-layer film, using a conventional adhesive, to a second film (=layer 4 ).
TABLE 6 EXAMPLE STRUCTURE 2 PE 2 /ZB 2 /OSB 2 /EV 2 //AD 2 //F 1 3 PE 2 /ZB 3 /OSB 2 /EV 2 //AD 2 //F 1 COMP. 2 PE 2 /OSB 2 /EV 2 //AD 2 //F 1
[0069] The target (and approximate actual) gauge (in mils) of each layer of the laminate structures of the invention was:
layer 1 layer 2 layer 3 layer 4 adhesive layer 5 0.20 0.20 0.50 1.00 (minimal) 0.50
[0070] The target (and approximate actual) gauge (in mils) of each layer of the comparative laminate structures was:
layer 1 layer 2 layer 3 adhesive layer 4 0.40 0.51 1.04 (minimal) 0.50
[0071] The film of Examples 2 and 3 were subjected to food law migration tests to evaluate whether zeolites could remove oxidation by-products. Their efficacy was compared with Comparative 2. The list of extractables can be found in Table 3. The test results from the extraction of the films with Miglyol 812 (available from Hüls America), a fatty food simulant, are summarized in Table 7. Zeolites can reduce the concentration of certain extractables which could cause regulatory issues.
TABLE 7 Migrant (ppb) COMP. 2 EX. 2 EX. 3 E 9 <Q.L. <Q.L. <Q.L. E 10 <Q.L. <Q.L. <Q.L. E 11 <D.L. <D.L. <D.L. E 1 980 1000 ± 5 875 ± 23 E 8 <D.L. <D.L. <D.L. E 12 <D.L. <D.L. <D.L.
[0072] D.L.=detection limit=50 parts per billion (food equivalent).
[0073] Q.L.=quantifiable limit=150 parts per billion (food equivalent).
[0074] In Table 8, three five-layer laminate structures in accordance with the invention, and one comparative five-layer laminate structure, are disclosed. The five-layer structures were each made by laminating a coextruded four-layer film, using a conventional adhesive, to a second film (=layer 5 ).
TABLE 8 EXAMPLE STRUCTURE 4 PE 2 /ZB 2 /OSB 3 /EV 2 //AD 2 //F 1 5 PE 2 /ZB 3 /OSB 3 /EV 2 //AD 2 //F 1 6 PE 2 /ZB 4 /OSB 3 /EV 2 //AD 2 //F 1 COMP. 3 PE 2 /PEB 2 /OSB 3 /EV 2 //AD 2 //F 1
[0075] The target (and approximate actual) gauge (in mils) of each layer of the laminate structures of the invention and the comparative was:
layer 1 layer 2 layer 3 layer 4 adhesive layer 5 0.15 0.15 0.50 1.00 (minimal) 0.50
[0076] Sliced turkey breast was stored in packages made from the films of Examples 4, 5, 6 and Comparative 3. A sensory panel tasted the turkey slices to evaluate whether or not zeolites can reduce the off-flavor caused by byproducts of the oxygen-scavenging reaction.
[0077] The films were triggered by ultraviolet light according to the procedure disclosed in U.S. Pat. No 5,211,875. The films were converted into packages on a Multivac® R7000 packaging machine. Cryovac® T6070B film was used as the bottom web of the packages. Each package contained one slice of turkey. Each package was flushed with a gas mixture consisting of 99% N 2 and 1% O 2 . Packages were stored in the dark for 7 days at 40° F.
[0078] A sensory panel rated the taste of the turkey slices. The scale ranged from 1 to 6, with 1 indicating extreme off-flavor and 6 indicating no off-flavor. The average scores are summarized in Table 9. In some cases, zeolites can reduce the off-flavor caused by the byproducts of the oxygen-scavenging reaction.
TABLE 9 Film Average Score 4 2.3 5 3.9 6 2.5 COMP. 3 2.6
[0079] In Table 10, two five-layer laminate structures in accordance with the invention, and two comparative five-layer laminate structure, are disclosed. The five-layer structures were each made by laminating a coextruded four-layer film, using a conventional adhesive, to a second film (=layer 5 ).
TABLE 10 EXAMPLE STRUCTURE 7 ZB 5 /PPB 1 /OSB 4 /ZB 6 //AD 2 //F 1 COMP. 4 PE 2 /PPB 1 /OSB 4 /PE 2 //AD 2 //F 1 8 ZB 5 /PPB 2 /OSB 4 /ZB 6 //AD 2 //F 1 COMP. 5 PE 2 /PPB 2 /OSB 4 /PE 2 //AD 2 //F 1
[0080] The target (and approximate actual) gauge (in mils) of each layer of the laminate structures of the invention and the comparative was:
layer 1 layer 2 layer 3 layer 4 adhesive layer 5 0.15 0.15 0.50 1.00 (minimal) 0.50
[0081] Sliced turkey breast was stored in packages made from the films of Examples 7 and 8 and Comparatives 4 and 5. A sensory panel tasted the turkey slices to evaluate whether or not zeolites can reduce the off-flavor caused by the byproducts of the oxygen-scavenging reaction.
[0082] The films were triggered by ultraviolet light according to the procedure disclosed in U.S. Pat. No 5,211,875. The films were converted into packages on a Multivac® R7000 packaging machine. Cryovac® T6070B film was used as the bottom web of the packages. Each package contained one slice of turkey. Each package was flushed with a gas mixture consisting of 99% N 2 and 1% O 2 . Packages were stored in the dark for 7 days at 40° F.
[0083] A sensory panel rated the taste of the turkey slices. The scale ranged from 1 to 6, with 1 indicating extreme off-flavor and 6 indicating no off-flavor. Table 11 summarizes the percentage of the panelists which did not taste an off-flavor (i.e. a score of 6) in the packaged turkey slices. In some cases, zeolites can significantly reduce the off-flavor caused by the byproducts of the oxygen-scavenging reaction.
TABLE 11 Percentage of Panelist which did not taste an off-flavor in the Film packaged turkey 7 39% COMP. 4 17% 8 17% COMP. 5 13%
[0084] A headspace gas chromatography (GC) method was used to determine the ability of a material to absorb aldehydes. The material (either 6 to 7 mg of powder or 25 mm disk of LLDPE film containing 4% absorber) was placed in a headspace GC vial (22 mL), and 2 μL of an aldehyde mixture containing about 0.1% each of the indicated aldehydes in methanol was injected into each vial. The vials were incubated at 80° C. for 1 hour and were injected into a GC. The data in Table 12 shows the percent change in the aldehyde concentration for each material relative to an appropriate control (vial with no absorber or LLDPE disk).
TABLE 12 Percent of Aldehydes Absorbed by Candidate Absorbers Sample Propenal Pentanal Hexanal Heptanal Octanal Percent Change Relative to Aldehyde Control Z 5 −77 4 −18 −21 −28 Z 6 −57 −93 −99 −100 −100 Percent Change Relative to LLDPE Control Z 4 −95 n/t c −100 −85 n/t Z 3 −92 n/t −77 −100 n/t
[0085] The data in Table 12 shows that various zeolites are capable of reducing the migration of aldehydes. In addition, due to specificity of various materials it can be seen that blends of materials can be advantageous.
[0086] Films of the invention can been made by any conventional means, including coextrusion, lamination, extrusion coating, or corona bonding, and then optionally irradiated and/or oriented. They can be made heat shrinkable through orientation or tenterframing if desired, at orientation ratios of 1:2 to 1:9 in either or both of the machine and transverse directions. For shrink applications, they can be made to have a free shrink of at least 10%, more preferably at least 20%, most preferably at least 30%, in either or both directions at 90° C.
[0087] Gasket compositions of the invention can be made by any conventional process, including, but not limited to, extrusion compounding for thermoplastic compositions, and conventional mixing equipment for plastisol compositions. The gasket compositions of the invention can then be formed into gaskets on lids by any conventional process, including but not limited to, cold molding processes, inserted discs, application of liquid plastisols via pressurized nozzles followed by solidification in an oven, etc.
[0088] Various changes and modifications may be made without departing from the scope of the invention defined below. For example, a blend of different zeolites can be used in the same article (e.g. film or sealing compound). In films, although it is preferred that the zeolite be used in the film and as a packaging material such that the zeolite is disposed closer to the contents of the package, which can be food or any oxygen-sensitive product, than the oxygen scavenger, there may be applications where the zeolite is disposed “outside of” the oxygen scavenger, such that the oxygen scavenger-containing layer is disposed closer to the contents of a package made from the film, than the zeolite-containing layer. The zeolite can alternatively be disposed on both sides of the oxygen scavenger. Also, within the same film, a first zeolite can be used in a first layer, and a second zeolite, different from the first zeolite, can be used in another layer of the film.
[0089] Alternatively, the zeolite, in addition to or instead of the arrangements described above, can be disposed in the same layer or layers as the oxygen scavenging material. Thus, by way of example, any of layers 14 , 34 , 44 , and 54 of the examples and figures can include any suitable percent, by weight of the layer, of a zeolite. A preferred blend of oxygen scavenging and zeolite in such a blend layer is between 95% and 99.5% oxygen scavenger, and between 0.5% and 5% zeolite. Any suitable polymeric materials can be employed in films containing the zeolites, and are not limited to those listed herein.
[0090] The amount of zeolite used in a film of the present invention is preferably between 0.1 % and 5% of the layer in which it occurs. These percentages are based on the zeolite material (e.g. zeolite) per se, with suitable adjustment to be made if the zeolite material is used as a masterbatch with another material such as polyethylene. Above 5% of the layer, optics of the film can be compromised to some extent, although the film can still be used in many applications. In end-use applications where optics are not a critical feature of the package, such as opaque films or gaskets for containers, higher amounts of zeolites can be beneficially used.
[0091] Zeolites disclosed herein can be used with or in films or coatings, or absorbed into a variety of other supports for scavenging or other uses, such as a layer or coating on another object, or as a bottle cap or bottle liner, as an adhesive or non-adhesive insert, sealant, gasket, fibrous matte or other inserts, or as a non-integral component of a rigid, semi-rigid, or flexible container.
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An article of manufacture includes an oxygen scavenger and a zeolite. The article can be in the form of e.g. a film or sealing compound. A package can be made from the article for containing an oxygen-sensitive article such as food. The zeolite reduces migration of odor causing by-products of the oxygen scavenging process. A method of making an article of manufacture having reduced migration of by-products of an oxygen scavenging reaction includes providing an article including an oxygen scavenger and a zeolite; and exposing the article to actinic radiation.
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BACKGROUND OF THE INVENTION
The present invention relates to a method of generating conversion formulas for obtaining analysis values and more particularly, to a method wherein such formulas enables the analysis value obtainable by, for example, an analyzer manufactured to be delivered to a customer, to coincide with those obtained by a reference analyzer.
There is a conventional analyzer in which a specimen such as blood and serum is dripped onto a slide to be analyzed that comprises a transparent support provided thereon at least one reagent layer and that exhibits change in optical density once a specimen adheres thereto, thereby reflected density is measured in order to determine presence/absence of a specific component or amount of the component. In such an analyzer, a slide to be analyzed is irradiated with light, and reflected light is collected, thereby based on the reflected light, progress, results or the like of specimen-reagent reaction is determined, and the measurement value is arithmetically processed to determine an analysis value.
However, the degree of reaction on a slide to be analyzed is not linear relative to the optical density of the reflected light. Therefore, if a measurement value is based on an optical reflection density, some conversion formula is indispensable for converting the optical density into the analysis value of concentration of a specific component in a specimen or of enzyme concentration.
With respect to such a conversion formula, it is noted in "Spectrometry in Clinical Biochemical Tests" (by Yoshino and Ohsawa, Gakkai Shuppan Center) that the correlation between a reflectance and concentration of substance can be defined by Kubelka--Munk's formula. This literature further mentions application of Williams--Clapper's formulas and those based on Beer's law. A technique using a conversion formula is disclosed in Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 32344/1987, while the same applicant proposes introduction of conversion formulas represented by hyperbolas, in Japanese Patent Open to Publication No. 111446/1988.
SUMMARY OF THE INVENTION
Such a conversion formula should be necessarily incorporated into another analyzer other than a reference analyzer. In doing so, one possible measure is as follows: the reference analyzer that has a built-in conversion formula is first prepared, and then, an analysis value obtained by another analyzer is adjusted to that of the reference analyzer, thereby measuring accuracy is improved. According to this arrangement, when incorporating an appropriate conversion formula into another analyzer by dripping a specimen onto an actual slide that is measured by a reference analyzer as well as by the other analyzer, where the analysis value of the other analyzer is adjusted to that of the reference analyzer, there occurs a problem due to fluctuation in analysis values based on dripped specimen. Dripping a specimen incurs more problems; for example, this technique involves a reaction time, and, accordingly, time for determining an analysis value becomes disadvantageously long.
With the above-mentioned problems taken into account, the present invention has for its object to provide a method of readily generating a conversion formula for obtaining an analysis value based on a measured value, at a lower cost, and in a shorter duration.
There is provided, to achieve the above-mentioned object, a method for generating a conversion formula wherein, on the basis of the measured values which are obtained by measuring a plurality of reference slides by a reference analyzer as well as by another analyzer, the conversion formula corresponds the analysis value of the other analyzer to the analysis value of the reference analyzer.
In the method embodying the present invention, a plurality of reference slides, which are prepared preliminarily and do not require dropping of a specimen thereon, are subjected to the measurement by both a reference analyzer and another analyzer so as to obtain measured values; the other analyzer is incorporates a conversion formula which makes its analysis values correspond to those of the reference analyzer on the basis of the measured values by the two analyzers.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings appended illustrate preferred embodiments of the present invention, wherein:
FIG. 1 is a block diagram explaining the invention as to its basic constitution;
FIG. 2 is an analyzer represented in a schematic elevational view in perspective;
FIG. 3 illustrates the operation control panel of the analyzer in FIG. 2;
FIG. 4 is an exploded view of a slide to be analyzed in perspective;
FIG. 5 represents a cross section of a slide to be analyzed;
FIG. 6 illustrates the mechanism of an analyzer in a schematic as well as block diagram;
FIG. 7 is a cross section taken along line VII--VII in FIG. 6;
FIG. 8 is a top plan view of the disk;
FIG. 9 illustrates the optical system in a cutaway view as well as block diagram;
FIG. 10 is a flowchart explaining the operation sequence of this analyzer;
FIG. 11 is a flowchart explaining how a conversion formula is obtained; and
FIG. 12 is a block diagram explaining another preferred embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention will be described hereunder with reference to the drawings appended.
FIG. 1 shows a first preferred embodiment of the present invention in a block diagram explaining its basic constitution.
Numeral 1 in this diagram indicates a reference slide, which is made of color paper, plastic, ceramic or the like, and has a shape identical to that of a slide 2 to be analyzed. In this embodiment, a plurality of reference slides 1 are prepared, and each of reference slides 1 is dyed in a predetermined color and is designed to give a specified reflection density when subjected to the measurement. The plurality of reference slides 1 are measured by both a reference analyzer 3 and another analyzer 4.
Measurements (reflection density) are obtained by means for obtaining measurement 5, 6 provided respectively on the analyzers 3, 4. A plurality of measurements obtained from the plurality of reference slides 1 by each analyzer are entered into means for obtaining primary regression formula 7 so as to obtain a primary regression formula that represents a relation between the measurements.
The so-obtained primary regression formula is substituted into the measurement term in the conversion formula in the reference analyzer 3 by "means for obtaining conversion formula for another analyzer" 8 so as to obtain a conversion formula whereby the analysis value obtained by the other analyzer 4 is made to agree with that of the reference analyzer 3. This conversion formula for obtaining an analysis value (concentration of a substance or enzyme activity value of a component of a specimen) from a measurement is incorporated into the other analyzer 4 so that an analytical curve corresponding to an item of measurement of a slide to be analyzed 2 can be determined.
One useful conversion formula possibly incorporated into the reference analyzer 3 is as follows: ##EQU1## which is described in Japanese Patent Open to Publication No. 111446/1988.
In the conversion formula (1), Y represents an analysis value which is the concentration of a substance as a component of a specimen, or the enzyme activity value; X represents a measurement which, in the case of end point measuring technique, is determined based on the reflection density, and, in the case of rate measuring technique, is determined based on change in reflection density that occurs as time elapses; A, B and C are constants determined based on the type of a slide to be analyzed and on characteristic values of the analyzer.
Accordingly, if the primary regression formula obtained by the means for obtaining primary regression formula is, for example:
X=ax'+b (2)
wherein X represents a measurement obtained by reference analyzer 3 and X' represents a measurement obtained by another analyzer 4. When the primary regression formula (2) is substituted into the measurement term of the aforementioned conversion formula (1), there can be obtained and loaded onto the other analyzer 4 a conversion formula expressed as ##EQU2##
Therefore, when a slide to be analyzed 2 is subjected to measurement by this analyzer 4 the conversion formula (3) enables the analyzer to produce from the reflection density measured an analysis value which agrees with that obtainable by the reference analyzer 3.
This conversion formula is generated by a computer provided outside the analyzer. It is also possible to obtain the formula by analyzer alone, by loading numerical data, which are processed by processing raw data, into the analyzer.
FIG. 2 shows a front elevational view of an analyzer embodying the present invention. In the analyzer body 11, there are provided a slide insertion part 12, specimen dripping part 13, slide discharge part 14, display 15, printer 16 and operation/control section 17. The display 15 indicates a description of an operation, error messages and the like.
FIG. 3 shows the operation/control section 17 provided with a set of numerical keys 18 for entering the date, etc.; minus key 19 for entering negative values; cancel key 20 for cancelling wrong entries such as in numerals; enter key 21 for entering numerals; paper feed key 22 for feeding recording sheet; reset key 23 used when a wrong slide has been loaded or the dripping of specimen is stopped; calibration key 24 for correcting the regression with the measurement by another analyzer or for calibrating a slide to be analyzed; control key 25 for making conversion formulas, decreasing warm-up time, for changing the indication on the display during the dripping, accessing stored data, changing the unit of measurement, changing the date, and the like; insertion complete/dripping start key 26 used once a slide to be analyzed has been loaded, and this key is also used to start dripping a specimen; and dripping complete key 27 used when the dripping has been completed.
FIG. 4 illustrates, in an exploded perspective view, and FIG. 5, in a cross-sectional view, "a slide to be analyzed" 2. The slide to be analyzed 2 comprises a mount base 28 having in its central recess a through hole 28a for photometry, wherein into the recess is loaded an analyzing element 29 having a reagent; a mount cover 30 centrally having a through hole 30a for specimen dripping is fitted to the mount base 28, and covers the analyzing element 29, wherein the mount base 28 and the mount cover 30 are bonded together with bonding means such as ultrasonic bonding. The mount base 28 is stepped at two sides 28b as a guide for insertion in place and the mount cover 30 has on the surface indications which are an arrow 31a showing the direction of loading a slide, measurement item description 31b, and a measurement item ID code 32 for recognition of the measurement item.
There are differences among the "slides to be analyzed" 2 with respect to the method and time of the photometric measurement as well as the measurement item. The slides suitable for end-point measurement are set for photometric measurement after an interval of 7 minutes following the completion of the dripping, examples of such slides being those of glucose (Glu), total cholesterol (T-Cho), hemoglobin (Hb), urea nitrogen (BUN), urea acid (UA), total protein (TP), albumin (Alb), triglyceride (TG), and total bilirubin (T-Bil). The slides 2 which are suitable for rate measurement are divided into two groups; the first group, such as glutamic-oxaloacetic transaminase (GOT) and glutamin-pyruvic transaminase (GPT), is set for the first photometric measurement after an interval of 7 minutes and the second measurement 11 minutes after the dripping and the second group, such as alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), is set for the first photometric measurement after an interval of 3.5 minutes and for the second measurement both 7 minutes after the dripping.
The reasons for the first photometric measurement in the rate measurement technique, i.e. 3.5 minutes after specimen dripping are that this allows longest possible duration for specimen dripping, and that this time setting, 3.5 minutes, can attain required measurement accuracy. The reason why, for some slides, the first measurement is performed 7 minutes after specimen dripping as in the case of the end point measurement technique is that, as known from experimental results and as described in Japanese Patent Application No. 75997/1986, there is little, if any, adverse effect by interfering substances, hence higher accuracy.
FIG. 6 schematically illustrates the mechanism and configuration of an analyzer embodying the present invention.
Once a slide to be analyzed 2 is inserted through a slide insertion part 12 with the stepped side 28b fitted on an insertion frame 33 so as to be carried into an incubation unit 36 by a slide roller 35 driven by an insertion motor 34. A CPU 39 controls the insertion motor 34 via a driving circuit 37 and via an interface 38 so that the motor is actuated only when the slide 2 can be inserted, thereby insertion of slides 2 is restricted to a number within the processing capacity.
The incubation unit 36 comprises, as shown in FIG. 7, a constant temperature heater plate 41 whose temperature is kept constant by heat radiating liquid 40 it houses; and a disk 43 which is transporting means axially supported on a rim 42 placed on the constant temperature heater plate 41. The heat radiating liquid 40 is provided with a temperature sensor 44, wherein the liquid temperature is regulated using an unshown heater that is controllingly actuated by the CPU 39 via a temperature control circuit 45 based on temperature data from the temperature sensor 44. A thermostat 46 is also provided as means for secure control of the temperature in order to prevent overheating. The disk 43 moves the slides to be analyzed 2 in a circumferential circle. This disk 43 has a heat-insulating cover 47 over it with a certain space therebetween.
Along the circumferential edge of the disk 43, there are disposed slide receivers 48 therein, each at an equal angle relative to an adjacent one, as shown in FIG. 8, being open at the circumference, wherein an opening 48a formed on the upper face of each receiver 48 is closed with an air-tight sealing lid 49 that serves as a closure means and fits into position. The sealing lid 49 is designed to resiliently press the inserted slide 2 from above. Radially from the circumference of the disk 43 there are formed grooves 43a therein, one between two adjacent slide receivers 48, and there is provided a revolving plate 50 with its axis coinciding with the circumference of the disk 43 and holding a pin 51 eccentrically positioned at the bottom which fits into and comes out of the grooves 43a as the revolving plate 50 is rotated in the direction of the arrow by a driving motor 52 placed thereabove. This driving motor 52 is actuated based on a signal from the driving circuit 37 so as to rotate the disk 43. There is also provided a disk-stopping device 53 which stops the disk 43 always at a correct position.
The embodiment described here has 20 such slide receivers 48, identified as address 1 through address 20 as shown in FIG. 8, of which address 1 is set as a part for calibration and the remaining 19 slide receivers, address 2 through address 20, are left open to 19 slides to be analyzed 2. Once a power switch provided on an appropriate position on the analyzer body 11 is turned ON, the disk 43 rotates in order to discharge possibly remaining slides which will be described later, and then stops with the slide receiver 48 of Address 2 at the position aligned with the slide insertion part 12 on the front of the analyzer body 11. Once a first slide to be analyzed 2 is inserted into the slide receiver 48 of Address 2, the insertion is detected by a slide insertion sensor 55 mounted on a sensor mount 54, and an insertion complete signal relevant thereto is loaded into the CPU 39 through the interface 38, and the CPU 39, upon receiving this signal, actuates the driving motor 52 through the driving circuit 37, moving the disk 43 forward one receiver position, so that a slide receiver 48 of Address 3 is aligned with the slide insertion part 12 to allow a second slide 2 to be inserted. Having been moved forward one receiver position, the first slide to be analyzed 2 positioned at Address 2 is now temporarily placed facing a disk address reading sensor 56 and a measurement item ID code-reading sensor 57, thereby the address on the disk 43 as well as the measurement item ID code are read by the sensors. The above-mentioned operation is repeated in sequence for a set number of slides to be analyzed, and the CPU 39 processes the data readout transferred via the interface 38, storing the addresses on the disk and the measurement items in a RAM 59 and selecting a measurement mode out of 0, 1, 2 and 3, which will be described later. A ROM 58 has a pre-written program that controls the CPU 39. Based on this program, the CPU 39 reads external data as required via the interface, or communicates data with the RAM, in order to perform arithmetic operations, and the CPU 39 loads data, generated as required, into the interface 38.
The specimen dripping part 13 mentioned previously has a specimen dripping hole 60 positioned outside of the disk 43. This specimen dripping hole 60 is closed by a shutter 62 under the force of a spring 61 when not in use. Slide reciprocating means 63 is provided inside the disk 43 in order to align the analyzing element 29 of the slide to be analyzed 2 with the specimen dripping hole 60. This slide reciprocating means 63 has a slide-pushing plate 64, which is slidably movable radially, and is connected via a link 65 with a plunger 66a of a dripping solenoid 66. The link 65 is pivotally movable on an axle 67. The dripping solenoid 66 is controlled by the CPU 39, and once it is energized, the plunger 66a is drawn against the force of the spring 68, causing the slide-pushing plate 64 to move in the arrow direction "a", thereby the slide 2 is pushed outward. Accordingly, the shutter 62 is pushed back against the force of the spring 61, thereby the dripping hole 60 is exposed, and the analyzing element 29 of the slide 2 is brought exactly under the specimen dripping hole 60 hole, completing a state where the specimen can be dripped.
The slide reciprocating means 63 is driven in a manner as follows: for first specimen dripping, once the "dripping start" key 26 on the "operation/control section" 17 on the analyzer body 11 is pressed, the CPU 39 energizes the dripping solenoid 66, causing a slide 2 to be pushed outside the slide receiver 48. For next specimen dripping onwards, the slide reciprocating means 63 operates automatically. After completion of specimen dripping, once the the "dripping complete" key 27 is pressed, the dripping solenoid 66 is turned off, and the slide-pushing plate 64, drawn by the spring 68, is retracted in the direction of the arrow "b", thus the slide 2 undergone specimen dripping returns to the corresponding slide receiver 48.
At the slide discharge port 14, there is provided a slide-discharging means 69 that discharges, outside the analyzer, the slides 2 having undergone photometric measurement. The slide-pushing plate 70 of this slide-discharging means pushes out the slides 2 as it moves in the direction of the arrow "a". The slide-pushing plate 70 is connected to the plunger 72a of a discharging solenoid 72 via a link 71 which is pivotally movable on the axle 73 and, when at rest, is pressed toward the inside of the disk 43, as drawn by a spring 74. When the discharging solenoid 72 is turned on to draw the plunger 72a in counter action against the force of the spring 74 so that the analyzed slide 2 in a slide receiver 48 is discharged from the analyzer. Once the discharging solenoid 72 is turned off, the slide-pushing plate 70 is retracted in the direction of the arrow "b". This retraction of the slide-pushing plate 70 is detected by a slide discharge sensor 5. The above-mentioned slide-discharging operation is repeated until all the analyzed slides 2 are discharged, and then the slide discharge sensor 75 outputs a signal signifying the completion of the discharge.
FIG. 9 illustrates an optical system embodying the present invention. This optical system comprises an irradiation unit 76 and a photometric part 77, and is designed to optically measure the reaction, as to the status or result, of a liquid specimen dripped on a slide 2 with a reagent which is contained in the analysis element 29 in the slide 2, particularly by examining the change in density of the color caused by the reaction. The system is arranged in a sealed box 78, protected from dust and other extraneous matter. In the irradiation unit 76, the light rays generated by a tungsten lamp, halogen lamp, or the like at the light source 79 are made into a light beam of a specified wavelength relevant to the slide to be analyzed 2 (wavelength relevant to the measurement item) by transmission through a cold filter 80, interference filter 81, lens 82, diaphragm 83 and lens 84, deflected on a mirror 85, and, after being transmitted through a transparent glass plate 86, the beam is projected on the measurement surface of the slide 2 through an irradiation part 88 formed in a converging unit 87. The reflected light is, via an optical fiber 89 of the photometric part 77, directed to a photoelectric element 90, where converted into an electrical signal, thereby the reflection density, i.e. optical density is determined. Then, referring to the calibration curve generated by the CPU 39 based on a conversion formula for each measurement item, the CPU 39 determines an analysis value based on the resultant measurement value, and then, a printer 16 prints the analysis value onto a roll of recording sheet, and the print-out leaves an exit formed on the upper face of the analyzer body 11. As shown in FIG. 6, above the photometric part 77 is disposed a presser mechanism 91b that is energized by a presser solenoid 91a. The presser mechanism 91b in the course of a photometric operation presses a slide to be analyzed downward for stabilization, in order to ensure accurate measuring.
Numeral 92 represents a calibration mechanism. This is calibration means that calibrates the photometric system at earliest possible timing before a slide is subjected to photometric operation, and this calibration is necessary because the intensity of a lamp in the light source 79 may not be always constant due to aging, electrical noise, or the like. The calibration mechanism 92 is a unit that is capable of accurately measuring an optical density, and has a slide 95 comprising a first reference plate 93 of a pre-measured low density level and a second reference plate 94 of a higher optical density, wherein the slide 95 is linearly reciprocated by a motor 96.
The calibration mechanism 92 verifies the light intensity of the light source 79. More specifically, the slide 95 is reciprocated both before and after insertion (before specimen-dripping) of a slide 2, wherein the light from the light source 79 reflected by, for example, the second reference plate 94 of a higher optical density, and the reflected light is transmitted via the optical fiber 89 to the photoelectric element 90, where converted into an electrical signal. The CPU 39 determines light intensity based on the optical density, and verifies the light intensity of the light source 79.
Based on a predetermined reference light intensity for verification, the CPU 39 estimates the remaining service life of the light source 79 and checks insufficiency in light intensity. A warning may appear on the display 15 as to the remaining service life of the light source 79. At this state, however, the analyzer is still operatable. In the case of insufficiency of light intensity of the light source 79, an error message appears on the display 15, and the operation of the analyzer is inhibited.
The operation sequence according to the present preferred embodiment of the invention is hereunder described referring to FIG. 10.
Once the power switch is turned on (Step a), the analyzer is initialized, where whether the calibration mechanism 92 is in an operatable position is detected and/or if there is a slide 2 not completely inserted into the slide insertion part 12, the slide 2 is pushed into position by the slide insertion roller 35 (Step b). Additionally, once the power switch is turned on, the incubation unit 36 is adjusted to a reaction temperature, and then, the measurement item ID code-reading sensor 57 detects whether there is a slide 2 in the disk 43, and, if there is a slide 2 remaining there, a slide receiver of an address of the remaining slide 2 is shifted to the position of the slide discharge part 14, and the slide is dischraged. Once that no slide receiver 48 has a slide 2 is detected, a slide receiver 48 of Address 2 is shifted to a position aligned with the slide insertion part 12 (Step c), and then, according to a specific requirement, an operator enters the current date, and specimen ID, by using numerical keys 18 on the operation/control section 17 (Step d).
Once the above-mentioned entry is complete, the slides to be analyzed 2 are loaded into position via the slide insertion part 12 (Step e). Once a first slide 2 is loaded into a slide receiver 48 of Address 2, the loading is detected by the slide insertion detection sensor 55, and the disk 43 is rotated one receiver position, and accordingly, a slide receiver of Address 3 is moved to the slide insertion part 12 on the analyzer body 11.
When a slide receiver 48 of Address 3 is aligned with the slide insertion part 12 on the analyzer body 11, the already inserted slide 2 of Address 2 rests in the halt position next to the slide insertion part 12, and at this position, an measurement item is read out using a code 32 (Step f), thereby the CPU selects a relevant measurement mode (Step g). Based on the so-read measurement item, the RAM 59 stores the data on which address's slide receiver 48 has a slide 2 of what measurement item, for example, GPT (rate measurement technique) or BUN (end point measurement technique).
Once all the slides to be subjected to photometric operation are loaded, the operator presses the insertion complete key 26 (Step h). Several seconds after, the slide insertion roller 35 stops, and Address 1 having not received a slide 2 and being vacant is moved to the photometric part 77. Then the calibration mechanism 92 disposed in the photometric part 77 is actuated to perform calibration (Step i). Next, the slide in the slide receiver 48 of Address 2 is shifted to the specimen dripping part 13 (Step j). Arrival of the slide 2 to the dripping part 13 is indicated by a buzzer or the like. Additionally, a specimen ID No., measurement item and the like appear on the display 15. Once verifying the indications on the display, the operator fills a pippet with a specimen being analyzed, and press the drip start key 26 on the operation/control section 17.
Pressing the drip start key 26 actuates the slide reciprocating means 63 so as to position the analysis element of the slide 2 exactly below the specimen dripping hole 60, and, at the same time, this positioning action allows the slide 2 press the shutter 62 to expose the specimen dripping hole 60. Next, the specimen in the pippet is dripped onto the analysis element 29 of the slide to through the specimen dripping hole 60 (Step k). Meanwhile, a duration from when the slide 2 is positioned exactly below the specimen dripping hole 60 to when the specimen is actually dripped is regulated by the CPU 39, in order to prevent from the shutter being open for an excessively long period.
Once specimen dripping is complete as mentioned above, the operator presses the dripping complete key 27. Then the slide reciprocating means 63 returns to its original position, and returns the slide 2 having received the specimen to the corresponding slide receiver 48 on the disk 43. Accordingly, the disk 43 rotates one receiver position, shifting a next address's slide 2 to the specimen dripping part 13. Once the dripping complete key 27 is pressed, the CPU 39 controls the duration from completion of dripping to photometric operation, for each slide to be analyzed; duration from dripping for a first slide to a photometric operation thereof (incubation duration); and a duration to second dripping.
Once all sides 2 have undergone specimen dripping, and when a predetermined time has elapsed, rotation of the disk 43 sequentially move the slide 2 of Address 2 onwards to the photometric part 77. The photometric part 77 performs a photometric operation (Step 1), and the printer 16 prints the analysis value onto a roll of recording sheet, that is discharged from the exit.
Once photometric operations with all the loaded slides 2 (slides undergone specimen dripping) are complete, these slides are sequentially transported to the slide discharge part 14, and are sequentially discharged outside (Step m). Once the discharging operation is complete, Address 2 is shifted to the slide insertion part 12, thus one cycle of analyzing operation is complete.
The slides to be analyzed 2 are subjected to a measurement operation in such a manner. Meanwhile, to generate a conversion formula for obtaining an analysis value based on a measurement value obtained by the analyzer, the control key 25 is pressed, as in Steps a and b of FIG. 10, following initializing, and after Address 2 of the disk 43 is transferred to the slide insertion part 12. A flow chart for generating a conversion formula of another analyzer 4 is given in FIG. 11.
The reference analyzer 3 has, for example, the previously mentioned conversion formula (1).
Once the control key 25 on the analyzer 4 is operated, in Step a, which input of the control key 25 is judged; and in Step b, whether the conversion formula generation mode has been selected is judged. If the current mode is not the generation mode, in Step c whether another mode for example the cleaning mode has been selected is judged. If another mode has been selected, processing based on this mode is performed in Step d.
Once the conversion formula generation mode is selected, the slide insertion roller 35 is rotated (Step e) so as to insert predetermined numbers of the reference slides 1 into the currently vacant Addresses on and after 2 (Step f). Once the predetermined numbers of reference slides 1 are inserted, the slide insertion roller 35 stops rotating (Step g). Next, Address 1 is transferred to the photometric part 77 (Step h), and then, the calibration mechanism 92 disposed on the photometric part 77 is actuated, and the interference filter 81 whose characteristic wave length being one appropriate for measurement is fit into position thereby calibration is performed (Step i).
Next, whether light intensity is insufficient is judged (Step j). If the light intensity is insufficient, an error message appears on the display 15 (Step k), stopping the analyzer (Step 1). If the light intensity is sufficient, whether the service life of the light source 79 is terminating is judged (Step m). If the service life of the light source 79 is nearing its end, "CHANGE LAMP" message appears (Step n).
The reference slide 1 loaded into the slide receiver 48 in Address 2 is transferred to the photometric part (Step o), and subjected to a photometric operation (Step p). The obtained measurement value on optical reflection density is stored in the RAM 59 (Step q). Thereafter, next reference slides 1 being loaded in addresses on and after 3 are sequentially transferred to the photometric part, thereby predetermined numbers of measurements are obtained (Step r).
A measurement operation, using the reference slides 1, in such a manner is also performed with the reference analyzer 3. The measurement values obtained by the reference analyzer 3 are read by a personal computer connected to the analyzer 3 (Step s). Based on this measurement values as well as based on a measurement values read from the RAM 59 of the analyzer 4 (Step t), the primary regression formula relevant to these measurement values is generated (Step u). Then the primary regression formula is substituted into the term in the conversion formula on the reference analyzer 3, thereby the conversion formula (3) relevant to the another analyzer 4 is generated (Step v), and the so-obtained conversion formula (3) is loaded into the RAM 59 (Step w), thereby an analytical curve is generated.
From then onwards, an analysis value of the analyzer 4 is determined by referring to the analytical curve generated using the conversion formula (3) based on a measurement value of a slide to be analyzed 2, wherein the analysis value is same as a measurement value of the reference analyzer 3. In this way, generating a conversion formula is performed using a reference slide 1. Accordingly, in contrast with a conversion formula generating technique based on specimen dripping onto a slide to be analyzed 2, this technique of the invention can reduce fluctuation in measurement values, and can decrease operation cost since the reference slide 1 is reusable, and, in addition, this technique eliminates an incubation duration, thereby an analyzer is readily matched with the reference analyzer 3.
FIG. 12 shows another preferred embodiment of the invention.
In this embodiment, using a reference analyzer 3 and another analyzer 4, a reference slide 1 is subjected to measurement specific times corresponding with a number of constants in a conversion formula that obtains an analysis value based on a measurement value.
For example, when generating a conversion formula (1) mentioned previously, three reference slides 1 are subjected to measuring, and independent means for obtaining measurement values 5 and 6 determine measurement values, correspondingly, X 11 , X 12 , and X 13 ; and X 21 , X 22 , and X 23 . Otherwise, using one such means, and using a plurality of reference slides, the obtained measurement values may be averaged.
Next, using means 9 for obtaining reference analysis value, reference analysis values Y 11 through Y 13 are determined based on the measurement values X 12 through X 13 that have been obtained by the reference analyzer 3, wherein conversion formulas used are: ##EQU3## wherein constants A 1 , B 1 , and C 1 in the formulas are predetermined ones.
Using means for obtaining conversion formula 10, constants are obtained based on the so-obtained reference analysis values as well as based on the measurement values obtained by the analyzer 4.
For example, based on reference analysis values Y 11 through Y 13 as well as based on the measurement values X 21 through X 23 , constants A 2 , B 2 , and C 2 are determined using the conversion formulas below: ##EQU4## wherein the conversion formulas into which these constants have been substituted are written onto a RAM 59 on the analyzer 4. Instead of being written onto the RAM 59, these conversion formulas may be stored in a ROM 58.
As can be understood from the description above, according to the method of the invention for generating a conversion formula that is used for obtaining analysis values, a plurality of reference slides are subjected to measuring operations with a reference analyzer as well as another analyzer, wherein based on each of the so-obtained measurement values, the analysis values of another analyzer are adjusted to those of the reference analyzer. Therefore, actually dripping a specimen onto a slide to be analyzed is not necessary, thereby measurement value fluctuation possibly caused by actual specimen dripping is eliminated. Additionally, use of a reference slide eliminates specimen dripping and reaction time, thereby the conversion formula is readily incorporated into an analyzer other than the reference analyzer, at a lower cost, in a shorter period.
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A method of producing an analytical curve for an analyzing apparatus which provides an analysis result on the basis of the analytical curve in response to a measurement value obtained by photoelectrically measuring light intensity reflected from a slide to be analyzed. A plurality of reference slides are measured by first analyzing apparatus which has a predetermined analytical curve, thereby obtaining a plurality of first measurement values and providing a plurality of first analysis results. The plurality of reference slides are further measured by second analyzing apparatus, thereby obtaining a plurality of second measurement values. Analytical curve for the second analyzing apparatus for produced on the basis of a relation between the first measurement values and the second measurement values so that a plurality of second analysis results correspond to the plurality of first analysis results.
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BACKGROUND OF THE INVENTION
This invention relates to an assembly for a display table.
For use in retail outlets, it is desirable to have a display table for merchandise which is easy to assemble and disassemble, yet sturdy enough to tolerate the strains and loads imposed by the quantities of merchandise on display and customer jostling.
To allow for change of display and easy storage, it has always been preferable to provide display table kits, which, after assembly, may be disassembled.
Traditionally, the parts of such display tables are fastened with bolts or screws, and generally require at least two people to assemble.
In order to ensure that the assembled table is sturdy, the bolts or screws must be fastened tightly, but this then makes disassembly much more difficult. It is also difficult to keep control of a number of bolt or screw fasteners, which easily become misplaced, preventing assembly of the table.
SUMMARY OF THE INVENTION
The present invention is directed to an improved construction for a display table which may be easily assembled by one person, and provides a sturdy display table which is also easy to disassemble for relocation and storage, and which does not rely on mechanical fasteners for stability.
In one embodiment, a table assembly is provided consisting of a tabletop frame which is constructed with an upper inwardly- and downwardly-directed peripheral flange forming a narrow channel. The tabletop frame is also constructed with a lower inwardly-directed flange which has at least three L-shaped apertures defined in it. A plurality of legs of angle-section (corresponding to the number of L-shaped apertures) is also provided. Each leg is upwardly receivable through one of the L-shaped apertures and is snugly receivable in the channel of the upper flange.
Preferably, the tabletop frame is of rectangular configuration, with an L-shaped aperture formed at each corner.
Also, two struts of angle-section may be mounted on two adjacent corners of the tabletop frame for mounting an upper shelf between them.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the complete display unit.
FIGS. 2 through 4 are partial perspective views showing the bottom part of the display unit in sequential stages of assembly.
FIGS. 5 and 6 are views similar to FIGS. 2 through 4 showing the top part of the display unit in sequential stages of assembly after that shown in FIG. 4.
FIG. 7 is a vertical cross-sectional fragmentary view, taken through line 7--7 of FIG. 1, showing the display unit.
FIG. 8 is a view, similar to FIG. 7, taken through line 8--8 of FIG. 3, showing the bottom portion of the display unit.
FIG. 9 is a perspective view of a tapered plug fastener used in assembling the display unit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a completely assembled display unit, according to the present invention is illustrated.
The assembled display unit includes a recessed rectangular table surface 1 bounded on all four sides by a tabletop frame 2. The tabletop frame 2 is mounted on four legs 3 of angle-section in the manner described below.
A lower shelf 4 is mounted between the four legs, and acts as a bottom brace to sturdy the entire structure.
Two struts 5 of angle-section are each provided with tongues 6 which are engageable in apertures 7 in adjacent rear corners 8 of the tabletop frame 2 for mounting the struts 5 to extend vertically upward from the tabletop frame 2.
A shelving bracket 9 is mounted on each strut, for supporting upper shelf 10.
FIGS. 2 through 6 illustrate the stages of assembly of a display unit according to the invention.
As shown in FIG. 2, the tabletop frame 2 is a rectangular rail, preferably of stamped and bent metal, formed in two sections, a front section 11 and a rear section 12.
Each section is provided with upper and lower peripheral flanges, 13 and 14 respectively. Lower flange 14 is provided with lip 14a to form a channel section (FIG. 6). Upper flange 13 is hemmed or rolled flat against the rail of the tabletop frame throughout most of the periphery except at the corners of the tabletop frame 2 where upper flange 13 is outwardly offset to form corner channels 13a. It is preferable if a V-notch is made in both upper and lower flanges 13 and 14 at each corner to facilitate the rolling in.
The hemming of the upper flange 13 against the rail of the tabletop frame 2 performs a reinforcing or stiffening function, as well as eliminating sharp edges which could damage displayed merchandise or be dangerous for customers.
To assemble, the front section 11 and rear section 12 are joined by inserting male ends 15 of the front section 11 into the channels formed by the upper flange 13 at 13a and by the lower flange 14, both of the rear section 12. Male ends 15 are offset so that a flush surface is formed on insertion with the rear section 12.
In order to completely secure the tabletop frame, the joints between the offset portions 15 and the sides 12 may then be spot-welded.
As illustrated in FIG. 2, the tabletop frame 2 is turned upside down to facilitate mounting of legs 3.
The legs 3 may be of any length required to provide a display table of useable height.
Preferably, legs 3 will be formed of bent metal, and therefore, customizing the height of the table to the retailer-customer's needs will be facilitated.
To mount the tabletop frame 2 on legs 3, L-shaped apertures 16 are provided in the lower flange 14 at each corner of the tabletop frame.
Each leg 3 is simply inserted into one of the L-shaped apertures 16 as shown at 17 in FIG. 2, and is snugly received under the corner channel 13a of the upper flange 13.
The corner channel flange 13a acts as an abutment or stop engaging longitudinally and locating laterally the tops of legs 3, so that when the display assembly is turned right side up, as shown in FIGS. 3 through 5, the tabletop frame rests on legs 3 at the upper corner channel 13a, and the upper ends of legs 31 held against movement away from corners of the frame, preventing swaying.
The legs 3 may be secured in place to prevent detachment when the display unit is being moved or lifted, through insertion of tapered plugs 18 (fully illustrated in FIG. 9) at the corners, securing tabletop frame 2 to each leg 3, but in the assembled, upright position, the display table does not rely on the plugs 18 for its stability. Only one plug 18 is required to be inserted at each corner.
Other fasteners such as screws and bolts may also be used, but are not needed and are not as easily removable for disassembly as the tapered plugs illustrated in FIG. 9.
The bottom of each leg 3 is folded over or beaded forming a foot flange 19 on each surface of the angle section. This eliminates any sharp edges, resulting from cutting the metal leg, which could damage floor surfaces.
The next stage of assembly, as illustrated in FIG. 3, requires that the display assembly be righted.
Lower shelf 4 is tilted to allow it to be inserted between the four legs 3 and is then rotated to the horizontal position and pushed downwardly as shown in FIG. 3 to provide a bottom brace to the display unit. The lower shelf 4 has outer sides with a peripheral circumference to provide lower bracing for the assembly by the action of the outer sides urging the legs resiliently outwardly, thereby preventing the legs from buckling due to loads placed on the display table assembly.
The legs 3 will be prevented from skewing outwardly by the opposite action of the tabletop rail 2 combined with the upper corner channels 13a on the tops of the legs 3.
The edge of the lower shelf 4 is provided with peripheral flange 21 which is rolled under to form a lip flange 21a engaging the foot flange 19 on each angle surface of each leg 3 to provide an abutment for the lower shelf 4 (FIGS. 7 and 8).
FIG. 4 illustrates the assembly of the table surface, composed of three rectangular leaves 22, which rest on the lower hem flange 14 of the tabletop frame in side-to-side abutment.
As shown in FIG. 7, the leaves will preferably be of similar construction to the lower shelf 4, that is provided with a peripheral flange 23. However, as shown in FIG. 6, the peripheral flange 23 is provided with notches 23a toward either end of each leaf 22 for accommodating lip 14a of lower flange 14 on the tabletop frame 2. In this way, leaves 22 hook onto lip 14a of lower flange 14.
Notches 23a interacting with lip 14a increase the rigidity of the table assembly by providing bracing for the upper portion of the table in one direction.
In order to increase the display capacity of the unit, according to the invention, an upper shelf may be added as illustrated in FIGS. 5 and 6, and as previously described.
Struts 5 are mounted on the rear corners 8 of the tabletop frame 2 by engaging tongues 6 projecting from each strut into corresponding apertures 7 provided in both the tabletop frame 2 and the inserted leg 3. The apertures 7 are preferably formed with a sloping lower edge so that the tongues 6 will tend to wedge into the apertures.
As shown in FIG. 2, all four legs 3 may be provided with apertures 7, thereby being interchangeable, to facilitate manufacture and ease of assembly. For the legs which become forward legs in the assembled display unit, the apertures 7 are hidden by the unbroken wall of the front section 11 of the tabletop frame 2.
The mounting of struts 5 on the tabletop frame 2 may be secured by insertion of a tapered plug 18 at each corner.
Preferably, a single tapered plug 18 may be used at each of the rear corners 8 to secure both the strut 5 and the leg 3 to the tabletop frame 2.
In addition, apertures 18a may be provided on each side of the tabletop frame for mounting store displays, such as sign holders (not shown) using tapered plug 18.
Each strut 5 is provided with a plurality of aligned slots 24, capable of receiving opposed upper and lower L-shaped projections 25a and 25b on shelving bracket 9, to mount the shelving bracket 9 on strut 5 as shown at 26.
Preferably, the aligned slots 24 will be provided on both angle surfaces of each strut so that the struts are interchangeable, thereby contributing to ease of assembly.
Upper shelf 10 is then placed on the two shelving brackets as shown in FIGS. 6 and 7.
Preferably an indentation 27 of channel section is formed between upper L-shaped projection 25a and the rear edge of bracket 9. As similar but narrower indentation 30 of channel section is also formed between the lower L-shaped projection 25b and the rear edge of bracket 9, but indentation 30 is preferably only wide enough to allow the lower L-shaped projection 25b to hook through one of the slotted apertures 24 on strut 5 with very little lateral allowance.
By contrast, indentation 27 formed with the upper L-shaped projection 25a is much wider, to allow projection 25a to be hooked first through one of the slotted apertures 24 with bracket 9 tilted upwardly, then allowing lateral sliding as the bracket is pivotted to the horizontal for hooking of projection 25b through a lower slotted aperture 24 on the same strut 5.
As shown in FIGS. 6 and 7, upper shelf 10 is preferably provided along its front and rear edges with rear flange 28 which engages in channel 27 in the bracket 9, and with the front flange 29 which hooks over the front of bracket 9, thus laterally securing the upper shelf 10 in place.
From FIG. 7, it will be observed that rear flange fits relatively snugly into indentation 27, thereby serving to lock the bracket 9 on strut 5 by reacting between the bracket and strut to urge the strut resiliently out into contact with the upper L-shaped projection 25a. Lower L-shaped projection 25b cooperates by being oppositely urged against strut 5 at its lower location on the strut.
Upper shelf 10 is further provided with back wall 30 which prevents displayed merchandise from falling off the back of the display unit.
From the foregoing description it will be obvious that three-legged display tables could also be constructed according to the invention with either round or triangular tabletop surfaces and modification in the angle of the angle-section legs and receiving apertures.
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A display table is provided which is easily assembled and disassembled for re-location and storage. The display table assembly includes a tabletop frame which is provided with an upper inwardly- and downwardly-directed peripheral flange forming a narrow channel, and a lower inwardly-directed flange. The lower flange has at least three L-shaped apertures defined in it. Where the tabletop frame is of rectangular configuration, an L-shaped aperture is formed at each corner. A plurality of legs of angle-section, with each leg being upwardly receivable through one of the L-shaped apertures and snugly receivable in the channel of the upper flange, are also provided. The table surface is formed of several leaves which rest on the lower flange of the tabletop frame. A base frame for urging the legs resiliently outward, may also be provided for improved stability of the assembled structure.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to programming and/or reprogramming of data stored in a point to point communication apparatus, particularly a portable communication apparatus such as a radiopager. It further relates to the combination of a programming apparatus and a point to point communication apparatus.
2. Description of the Realted Art
It is customary to program, reprogram or read a program store coupled to a microcontroller in a portable point to point radio apparatus, such as a radiopager, either by means of electrical contacts provided in the pager, for example in the battery compartment, or by over-air messages carrying a special identification which causes the processor to permit access to the RIC or configuration store. The use of electrical contacts has the disadvantages of reliability due to wear and contamination, cost of supply and fitting and the need to partially disassemble the equipment to gain access to them. Over air programming or reprogramming requires the provision of a pre-programmed default condition, and special radio identification code (RIC). This technique has a disadvantage that, due to falsing on error correction of a message, an equipment can be reprogrammed accidentally or incorrectly.
SUMMARY OF THE INVENTION
An object of the present invention is to program or reprogram a point to point communications apparatus in a reliable but cost effective manner.
According to one aspect of the present invention there is provided a point to point communication apparatus comprising radio receiving means, signal decoding means coupled to the radio receiving means, processing means for controlling the operation of the radio receiving means and the decoding means, a program memory coupled to the processing means, an electrically programmable store coupled to the processing means, optical radiation sensing means coupled to the processing means for providing an electrical version of received optical radiation, the processing means in response to recognising electrical versions of coded optical radiation signals received by the sensing means, causing said electrically programmable store to be programmed or reprogrammed.
According to a second aspect of the present invention there is provided a combination of a programming apparatus and a point to point communication apparatus, the programming apparatus comprising a controller, means for inputting program data coupled to the controller, an optical radiation emitting device and means coupled to the controller and the optical radiation emitting device for providing a version of the program data suitable for transmission by the optical radiation emitting device, and the communication apparatus comprising radio receiving means, signal decoding means coupled to the radio receiving means, processing means for controlling the operation of the radio receiving means and decoding means, a program memory coupled to the processing means, an electrically programmable store coupled to the processing means, optical radiation sensing means coupled to the processing means for providing an electrical version of received optical radiation, and means for providing an optical interface between the optical radiation emitting device and the optical radiation sensing means, the processing means in response to recognising electrical versions of coded optical radiation signals received by the sensing means causing said electrically programmable store to be programmed or reprogrammed.
Programming/reprogramming the electrically programmable store using optical radiation signals avoids the disadvantages noted above in respect of the known techniques. The electrically programmable store may comprise a radio identification code (RIC) and/or configuration store.
If desired the communication apparatus may comprise light emitting means, driver means having an input coupled to the processing means and an output coupled to the light emitting means, whereby the processing means causes optical signals to be emitted in response to reading-out of the RIC or configuration store. The provision of light emitting means enables signals to be read-out from the RIC or configuration store in a reliable manner, thus enabling verification of programmed data.
The apparatus may further comprise a LCD panel for displaying data, drive means for driving the LCD panel, the drive means being coupled to the processing means and means for back lighting the LCD panel, wherein the output of the optical radiation sensing means is also used by the processing means to sense ambient light conditions, said processing means causing the back lighting means to be energised when data is to be displayed on the LCD panel under adverse ambient light conditions. In such an apparatus the optical radiation sensing means serves a dual function which avoids having to provide a second light sensing means on the housing of the apparatus where space is a premium.
It is known from U.S. Pat. No. 4,754,275 to provide a pager with a LCD panel with a back light to permit viewing under adverse lighting conditions and a light sensor to enable the ambient light to be monitored and thereby the energisation of the back light to be controlled.
JP 59-169237 discloses a contactless connection system for optically communicating data in both directions between a portable terminal and a data transmitter using specially provided light emitters and detectors which are juxtaposed when data is being transferred. There is no suggestion of transmitting programming or reprogramming data via an optical interface, and more particularly of using an already provided light detector so as to obtain the advantages of saving the cost of supplying and fitting an additional optical radiation detector on the casing, which on physically small equipments can be difficult.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, wherein
FIG. 1 is a block schematic diagram of a digital radiopaging system including a radiopager having a back lit LCD panel and a programmer optically coupled to the radiopager,
FIG. 2 is a block diagram of an alternative arrangement for programming/reprogramming the radiopager,
FIG. 3 is a flow chart relating to the normal operation of a back light in the radiopager,
FIG. 4 is a flow chart relating to programming/reprogramming a RIC or configuration store of a radiopager using the ambient light detector, and
FIG. 5 is a flow chart relating to programming/reprogramming a RIC or configuration store of a radiopager not having an ambient light detector.
In the drawings, the same reference numerals have been used to indicate corresponding features.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The radiopaging system shown in FIG. 1 comprises a base station 10 and a radiopager RP which is able to roam in and out of the radio coverage area of the base station 10.
The base station 10 comprises a controller 12, a radio transmitter 14 and an antenna 16. The controller 12 carries out a variety of tasks, known per se, including encoding and formatting address and data codewords in accordance with a predetermined protocol such as the CCIR Radiopaging Code No. 1 (otherwise known as POCSAG).
The radiopager RP comprises an antenna 18 coupled to a radio receiver 20, for example an integrated receiver type UAA 2080T produced and marketed by Philips Semiconductors. A decoder 26 is connected to the receiver 20 for decoding address and message codewords. A processor or controller 22 is connected to an output of the decoder 26. The decoder 26, for example an OM 1057 produced and marketed by Philips Semiconductors, performs a variety of tasks amongst which are switching the receiver on and off, synchronisation and error checking and correcting the received address and, if sent, message codewords. The controller 22 is controlled by software stored in a non-volatile program memory 24, such as an EPROM or masked ROM and processes messages received by the receiver and decoder for storage and subsequent display. Messages are stored in a random access memory (RAM) 28 for later recall. A keypad 30 is connected to the controller 22 for entering manual commands. An electrically programmable store 32 for storing one or more RICs assigned to the radiopager RP and pager configuration information is coupled to the decoder 26 which includes means for comparing the received address codewords with the or each RIC and in the event of a match the decoder 26 supplies an appropriate output signal to the controller 22. In operation, the receiver 20 is energised for the duration of a pre-determined frame and if a received RIC corresponds to the or one of those stored in the RIC store 32 then the controller 22 energises an annunciator 40 and/or a light emitting diode 42 thereby alerting a user to the receipt of a paging signal. If the received RIC is followed by data codewords, these are decoded in the decoder 26 and the result is either stored in the RAM 28 or displayed. The stored data is read-out of the RAM 28 in response to a command entered by way of the keypad 30 and supplied to a liquid crystal display (LCD) driver 44 which energises a LCD panel 46 accordingly.
A back light 48 is provided in order to be able to view data displayed on the LCD panel 46 under adverse lighting conditions, for example darkness. However since the back light 48 is not required under good lighting conditions and in order to conserve battery power, a light detector 50, for example a light sensitive transistor, is coupled to the controller 22. When the ambient light is below an arbitrary threshold level then the output of the light detector 50 causes the controller to energise the back light 48 when message information is displayed. A timer 52 is connected to the controller Z2 and amongst its functions is that of causing the back light 48 to be energised for a predetermined period of time after which the back light 48 is switched-off to save battery power.
In order to program or reprogram the radiopager RP, that is enter or alter the software in the RIC or configuration store 32 and perhaps also a part of the program memory 24, a programmer 54 comprising a personal computer is coupled optically to the radiopager RP. The programmer 54 comprises a processor 56 to which is coupled a keyboard 58, a disk drive 60 for reading disks, a video display unit 62 and a modem 64 for encoding electrical signals to a form suitable for transmission by a light emitting diode (LED) 66 and decoding optical signals received by a photo sensitive device 68.
In accordance with the present invention, programming or reprogramming is carried by optically coupling the LED 66 to the light detector 50, for example by an optical fibre 70. The light detector 50 is coupled to the RIC store 32 by the controller 22 in response to relatively high rate, for example 1200 baud and greater, pulse signals being received. The pulse repetition rate and protocol of the light signals from the LED 66 is such that for example the mains flicker from a fluorescent lamp is not interpreted as a coded signal. Thus depending on the current status of the radiopager RP, the light detector 50 serves either one of two functions. In a non-illustrated embodiment of the present invention not having an ambient light detector or having a separate ambient light detector, the light detector 50 is provided for the sole purpose of being able of program/reprogram data in the RIC store 32.
Verification of any programming or reprogramming instructions are relayed optically to the programmer 54 using a LED driver 72 and the LED 42. An optical fibre 74 conveys the verification signals to the photosensitive device 68.
The optical sequences supplied by the LED 66 may be in accordance with a protocol which the controller 22 recognises as being suitable for programming or reprogramming the RIC store 32. Alternatively and/or additionally the keypad may be operated to select a special screen for programming or to place the pager in a special mode after which the optical interface is used to transfer programming data.
FIG. 2 illustrates a programmer 54 comprising a slot 76 of a size and shape to receive a radiopager RP. The walls of the slot 76 form a light shield. A LED 66 is disposed in a wall of the slot 76 so as to be opposite the light detector 50 and a photo sensitive device 68 is located in a wall of the slot 76 at a position opposite the LED 42. For the sake of completeness a controller 22 has been illustrated having connections to the light detector 50 and the LED 42.
The programming and/or reprogramming is carried out in a similar manner as with the arrangement shown in FIG. 1.
FIG. 3 is a flow chart of the basic operation of the light detector 50 and the back light 48 when displaying a newly received message or a message read-out of the RAM 28 and supplied to the LCD driver 44. The controller 22 includes means for energising the back light 48 for a predetermined time period in response to a user actuating a switch to display the message. If the predetermined time period expires before the entire message has been read, then re-actuation of the switch will cause re-energisation of the back light 48 for another predetermined time period. The sub-routines identified as P, Q and R are also used in FIG. 4.
Referring to FIG. 3, the flow chart commences with a check being made to see if the read display switch has been actuated, block 80. If the answer is Yes (Y) then a sub-routine identified by the letter P is followed. This sub-routine commences with the block 81 which relates to displaying a message from the RAM 28 on the LCD panel 46. In block 82 a check is made if it is too dark for the message to be viewed. If the answer is Yes (Y), then in block 83, the back light 48 is energised. Simultaneously, in block 84, timer 52 is actuated to commence the time-out period for the energisation of the back light 48.
If the answer in the block 82 is No (N), then the flow chart from that block together with that from the block 84 proceeds to a process block 85 which relates to the process of incrementing the time out.
Reverting to the block 80, if the answer is No (N), then a check is made if a new paging message has been received, block 86. If the answer is No (N), then flow chart proceeds to the block 85. If the answer is Yes (Y) then a sub-routine identified by the letter Q is followed. This sub-routine commences with a block 87 which relates to the process of storing the newly received paging message in the RAM 28. Block 88 relates to the process of displaying the newly received paging message on the LCD panel 46. In block 89 a check is made to see if it is dark. If the answer is No (N) then the flow chart proceeds to the block 85. If the answer is Yes (Y), then in blocks 90,91, which correspond to the blocks 83,84, the back light 48 is energised and the timer 52 is actuated to commence the time out period. The flow chart then proceeds to the block 85.
Continuing from the process block 85, in a block 92 a check is made if the back light time out period has elapsed. If the answer is Yes (Y) then in block 93, identified as sub-routine R, the back light 48 is de-energised. If the answer is No (N) then the flow chart from that block and from the block 93 reverts to the block 80.
In the case of programming or reprogramming the radiopager, a data terminal, such as a programmer 54 (FIG. 1), is optically coupled to the light detector 50 for example by the optical fibre 70. Coded signals are then transmitted to the light detector 50 and passed to the controller 22. The transmission commences with a special sequence which on being recognised by the controller 22 causes it to access the RIC store 32 to enable it to be programmed/reprogrammed as required in accordance with the received data. In the event of a paging message being received by the receiver 20, it will be decoded and stored in the RAM 28. A tone only message will be treated normally and the annunciator 40 is energised.
FIG. 4 is a flow chart of the sequence of operations involved when the light detector 50 receives coded data for programming/reprogramming the RIC store 32. The flow chart begins at block 100 which relates to the operations of starting the timer 52 (FIG. 1) and receiving programming data. Block 102 relates to checking to see if the keypad 30 has been actuated to read out message data from the RAM 28. If the answer is Yes (Y) then the sub-routine P in FIG. 3 is followed. If the answer is No (N) then a check is made to see if a new call has been received, block 104. If the answer is Yes (Y) then the sub-routine Q in FIG. 3 is followed. If the answer is No (N) then a check is made in block 106 to see if the back light has timed out. If the answer is Yes (Y) then the sub-routine R in FIG. 3 is followed. A No (N) answer causes the flow chart to proceed to block 108 in which a check is made as to whether the data input timer has elapsed. If the answer is No (N) then in block 110 a check is made to see if the light detector 50 is receiving data. In block 112, a check is made to see if data has been detected. A No (N) answer from this block or a Yes (Y) answer from the block 108 causes the flow chart to revert to the block 102. A Yes (Y) answer from the block 112 leads to the block 114 in which a check is made to see if any commands have been received. A Yes (Y) answer leads to a block 116 which relates to the process of defining the store address. Block 118 relates to defining whether the instruction is a read/write instruction. Finally in this leg of the flow chart, the data input timer is reset. The flow chart then reverts to the block 102.
If the answer from the block 114 is No (N), a check is made to see if the command is a read or a write command. If the command is "write", the input data is stored at the addressed location, block 124. Thereafter the flow chart reverts to the block 102. If the command is "Read", data is read-out from the addressed locations, block 126, and is either displayed on the LCD panel 46 (FIG. 1) or supplied to LED driver 72 (FIG. 1), block 128. Thereafter the flow chart reverts to the block 102.
FIG. 5 is a flow relating to programming/reprogramming the RIC store of a pager which has a separate light detector for programming/reprogramming, no back light control for an LCD panel or no LCD panel for displaying numeric and alphanumeric messages, for example a tone only pager. This flow chart is a simplified version of that shown in FIG. 4 because the operations associated with back light control have been omitted as they are not required. In the interests of brevity the entire sequence of operations will not be described. However it is sufficient to say that the flow chart commences with a block 101 which relates to putting the pager in a programming mode. An output of this block 101 is coupled to the block 110 which relates to checking the light detector 50 for data input, block 110. A check is made in block 110 to see if data has been detected and if it has (Y) then the flow chart proceeds to block 114 as described previously. However if it has not (N), the flow chart reverts to block 110.
Blocks 126 and 128 relate to verifying that the data received by way of the optical interface is correct by either displaying it on the LCD panel 46, if provided, and/or relaying it back to the programmer 54 by way of the LED 42.
Finally, from the blocks 120, 124 and 128, the flow chart passes to a decision block 130 which relates to the step of checking whether the programmable mode has timed out. If the answer is No (N) the flow chart reverts to the block 110. However if the answer is Yes (Y) the flow chart proceeds to exit block 132.
Although the present invention has been described with reference to a radiopager, it is to be understood that the teachings of the present invention can be applied to any suitable point to point communication apparatus, such as a cordless or cellular telephone or a private mobile radio transceiver, irrespective of whether it has an LCD panel which can be back lit in response to a light sensor detecting poor ambient lighting conditions.
From reading the present disclosure, other modifications will be apparent to persons skilled in the art. Such modifications may involve other features which are already known in the design, manufacture and use of radio apparatus and component parts thereof and which may be used instead of or in addition to features already described herein.
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A point to point communication apparatus, such as a digital radiopager (RP), having a non-volatile electrically programmable store which stores a radio identification code (RIC) or apparatus configuration information. The store can be programmed/reprogrammed by sending coded light signals to a light sensor. The coded programming/reprogramming light signals are supplied from an external source, such as a personal computer, and conform to a protocol which on being recognized causes a controller to permit access to the programmable store. The light sensor may also be used to sense the ambient light and control energization of a back light of a LCD panel.
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BACKGROUND
[0001] The present specification relates to the field of instant messaging exchanges. Specifically, the present specification relates to the field of user-generated multimedia content in instant messaging exchanges.
[0002] Instant messaging allows parties to communicate remotely with each other via computers, mobile devices, or other electronic devices capable of such exchanges. Instant messaging is a type of real-time communication between two or more people that is generally based on typed text. The text may be conveyed by devices electronically or wirelessly connected over a network, such as the Internet or a cellular phone network.
[0003] Instant messaging has become widely used in many different applications and allows people to communicate with each other in a low attention, low commitment, passive exchange, while being able to continue to perform other tasks simultaneously. Some businesses also use instant messaging for quick, textual exchanges that generally produce better responsiveness than email and are less intrusive than phone calls or other remote methods of communication.
BRIEF SUMMARY
[0004] A method for displaying multimedia content created by a user of a first computerized messaging device to a user of a second computerized messaging device communicatively coupled to the first computerized messaging device by a network includes: displaying, with the second computerized messaging device, a textual instant messaging exchange between the user of the first computerized messaging device and the user of the second computerized messaging device; receiving the multimedia content at the second computerized messaging device over the network; and dynamically embedding a player for the multimedia content in-line in the display of the textual instant messaging exchange at the second messaging device.
[0005] An instant messaging system includes: a computerized messaging device having a processor and memory communicatively coupled to the processor. The computerized messaging device is configured to: exchange textual instant messages with a remote device over a network and display the textual instant messages to a user; receive multimedia content from the remote device, the multimedia content being related to the textual instant message exchange; and dynamically embed a player for the multimedia content in-line in the display of the textual instant messages to the user.
[0006] A computer program product for incorporating user-generated multimedia content in an instant message exchange includes a computer readable storage medium having computer readable program code embodied therewith. The computer readable program code includes computer readable program code configured to: exchange textual instant messages with a remote device over a network and display the textual instant messages to a user; receive multimedia content from the remote device, the multimedia content being related to the textual instant message exchange; and dynamically embed a player for the multimedia content in-line in the display of the textual instant messages to the user.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0007] The accompanying drawings illustrate various embodiments of the principles described herein and are a part of the specification. The illustrated embodiments are merely examples and do not limit the scope of the claims.
[0008] FIG. 1 is a diagram of an illustrative system for an instant messaging exchange, according to one exemplary embodiment of principles described herein.
[0009] FIG. 2 is a diagram of an illustrative system for incorporating user-generated multimedia content in an instant messaging exchange, according to one exemplary embodiment of principles described herein.
[0010] FIG. 3 is a diagram of an illustrative system for incorporating user-generated multimedia content in an instant messaging exchange, according to one exemplary embodiment of principles described herein.
[0011] FIG. 4 is a diagram of an illustrative system for incorporating user-generated multimedia content in an instant messaging exchange, according to one exemplary embodiment of principles described herein.
[0012] FIG. 5 is a flowchart showing an illustrative method of incorporating user-generated multimedia content in an instant messaging exchange over a network, according to one exemplary embodiment of principles described herein.
[0013] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.
DETAILED DESCRIPTION
[0014] The present specification discloses a method, system, and computer program product relating to incorporating user-generated multimedia content into an instant messaging exchange. According to the principles described herein, a user may record or otherwise generate multimedia content at a first messaging device to be sent to a second messaging device that has an established instant messaging exchange connection using an instant messaging client. The user-generated multimedia content may be embedded in the instant messaging client in-line with other text in the instant messaging exchange.
[0015] As used in the present specification and appended claims, the term “instant messaging exchange,” “instant messaging,” or “chat” refers to a real-time text-based exchange over a remote connection, such as a wired or wireless network. The instant messaging exchange may take place via an instant messaging client on at least two devices capable of instant messaging, such as a computer, a cellular phone, a personal digital assistant, and others. Specifically, the instant messaging client allows a user to record user-generated multimedia on a first messaging device to be sent to and displayed on a second messaging device.
[0016] As used in the present specification and appended claims, the term “user-generated multimedia content” refers to video, audio, or other multimedia content that is recorded or created by the user through either a microphone, camera, or other multimedia capturing device.
[0017] As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
[0018] Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
[0019] A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
[0020] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wire line, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
[0021] Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java, Smalltalk, C++ or the like. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0022] The present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions.
[0023] These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0024] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
[0025] The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0026] With reference now to FIG. 1 , an illustrative system ( 100 ) capable of and instant messaging exchange is shown. The system includes first and second messaging devices ( 105 , 110 ) in communication with each other through a network ( 115 ). The messaging devices ( 105 , 110 ) may be any device capable of real-time text-based communication through a remote connection, including, but not limited to, desktop computers, laptop computers, cellular phones, personal digital assistants (PDAs), or any combination of the aforementioned devices. The network ( 115 ) may be either a wired network or a wireless network, or a combination of both.
[0027] The instant messaging exchange may take place using an instant messaging client. Many such instant messaging clients exist as individual applications or in-browser clients, for example. Instant messaging is an increasingly popular and widely used method of communicating between two remote points on a network. Instant messaging is a form of text-based communication that allows users to communicate through a low attention, low commitment exchange. Modern instant messaging systems allow for a variety of multimedia connections to be established between messaging devices in which users can either hear or see each other through audio or video connections. These connections are generally created when a first user sends a request to a second user to initiate a multimedia connection and the second user accepts the request. Additionally, such connections may require a higher level of attention and commitment than simple text-based conversations. Because of the attention and commitment required, users may be hesitant to engage in such exchanges.
[0028] The system of the present specification allows multimedia content such as audio and video to be sent between users without requiring the attention and commitment that the multimedia connections typically included in other instant messaging clients. Accordingly, a first user at the first messaging device ( 105 ) may engage in an instant messaging exchange with a second user at the second messaging device ( 110 ). While the present description refers principally to first and second messaging devices ( 105 , 110 ), the instant messaging exchange may also include more than two users/devices in a group exchange.
[0029] During the exchange, a first user involved in the exchange may desire to send video or audio to a second user in the exchange. Rather than establishing a real-time multimedia connection with the second user, the first user is able to record the multimedia content at the first messaging device ( 105 ) and send it to the second messaging device ( 110 ) as part of the instant messaging exchange. When the multimedia content has been transmitted to the second messaging device ( 110 ), the multimedia content may be played back at the second messaging device ( 110 ) for the second user. In this manner, the first user is able to record audio or video and send it to the second user without the need to set up an actual video or audio connection. The ability to send video or audio without committing to a direct speech or video based conversation may be preferred at times when the users do not have time to devote much or all of their attention to a potentially complex or involved conversation. Sending user-generated multimedia content in this manner also provides a method for the users to explain elements of the conversation more effectively than through text exchange only.
[0030] With reference now to FIG. 2 , an illustrative system for incorporating user-generated multimedia content in an instant messaging exchange is shown. The instant messaging exchange may take place on an instant messaging client ( 200 ). As with may typical instant messaging clients, the client ( 200 ) shows the text ( 205 ) exchange between the users involved in the conversation in the chat transcript ( 240 ), as well as which user entered each text entry. The client ( 200 ) may also list all of the users or chat participants ( 210 ) that are presently participating in the chat. The client ( 200 ) also includes a text entry field ( 215 ) where users may input text to be submitted to the conversation, as shown at the bottom of the client ( 200 ) in FIG. 2 . The client ( 200 ) may also include other chat information, as well as a menu ( 220 ) or toolbar.
[0031] The menu ( 220 ) may have options that allow the user to customize various visual aspects of the client ( 200 ) interface, for example customizing the font size, style, and color of the text during the chat, or customizing which information is displayed in the client interface. In addition to customizing options, the menu ( 220 ) may also include an option to open a recording interface ( 225 ) in order to record user-generated multimedia content for submitting to the chat. Alternatively, the recording interface ( 225 ) may be part of the original client interface and may have buttons that allow the user to record multimedia content without opening a separate recording interface window.
[0032] Using the recording interface ( 225 ), the user may have the option to record different types of multimedia, such as audio, video, or both. The recording interface ( 225 ) may be divided according to the type of multimedia that the user desires to record, as shown. If the user desires to record audio, the user clicks a record button in the audio recorder ( 230 ). If the user desires to record video, the user clicks a record button in the video recorder ( 235 ). The video recorder ( 235 ) may also record audio simultaneously with the video. The user may need multimedia input devices connected to or built into the messaging device in order to record user-generated multimedia content, such as a microphone and/or a camera.
[0033] When the user clicks the record button in the recording interface ( 225 ), the specified input device is activated and begins recording. The recording interface ( 225 ) may display feedback to indicate that the input device is operating correctly. For example, the video recorder ( 235 ) may display the video that is being recorded by the camera. The audio recorder ( 230 ) may display a frequency response of the audio input. The recording interface ( 225 ) may also allow the user to play back the multimedia that has been recorded in order to verify that the recording includes the correct content and that no errors occurred during the recording. After recording the multimedia content, the user may click a submit button on the recording interface ( 225 ) to submit the content to the instant messaging exchange. According to another embodiment of the chat client, the multimedia content is sent automatically when the user presses a stop button.
[0034] With reference now to FIG. 3 , another illustrative embodiment of a system for incorporating user-generated multimedia content into an instant messaging exchange is shown. After submission, the multimedia content ( 305 ) is published or embedded in-line in the chat transcript ( 240 ) with the text of the chat transcript so that all participants of the chat may see the content in the client ( 200 ).
[0035] The multimedia content ( 305 ) is embedded in the chat transcript ( 240 ) chronologically, so that the users may see when the multimedia content ( 305 ) was entered, which may help in understanding the context of the multimedia content ( 305 ), particularly if a user desires to view the exchange at a later time. The entire content of the instant messaging exchange may be saved for later viewing after the client interface or chat window has been closed. Multimedia content ( 305 ) embedded in the chat transcript ( 240 ) may be stored with the transcript of the text, or the content ( 305 ) may be stored in a separate folder such that the users may look at all of the multimedia content ( 305 ) that has been exchanged. In embodiments where the multimedia content ( 305 ) is stored in a separate folder, the transcript may contain a link to the multimedia content ( 305 ) such that the content is still in-line with the text for viewing by a user. The stored multimedia content ( 305 ) may also be stored in folders according to date or instant messaging exchange, according to the desired organization. This ability to go back and view the multimedia content ( 305 ) at a later time provides an advantage over real-time video and audio connections that are present in instant messaging clients of the prior art, which typically do not provide a way for the multimedia exchange to be recorded.
[0036] After the multimedia content ( 305 ) is embedded in the chat transcript ( 240 ), the conversation may continue with additional text ( 310 ) following the multimedia content ( 305 ) in the transcript ( 240 ). Additional multimedia content may be added such that the chat transcript ( 240 ) may contain several instances of multimedia content. Consequently, it is possible that a majority of an instant messaging exchange may be user-generated multimedia content that has been exchanged between the chat participants ( 210 , FIG. 2 ). The multimedia content ( 305 ) may be useful for explaining concepts that would be more difficult to explain through text, and therefore may reduce the length of the chat transcript ( 240 ), making navigation through the transcript ( 240 ) easier.
[0037] With reference now to FIG. 4 , another illustrative embodiment of a system for incorporating user-generated multimedia content into an instant messaging exchange is shown. According to some embodiments, the user-generated multimedia content ( 305 ) may be replaced or succeeded by a transcript ( 400 ) of the audio portion of the recording. The audio transcript ( 400 ) may be created by a speech-to-text conversion process after the content ( 305 ) is recorded. The audio transcript ( 400 ) may be attached to the multimedia content ( 305 ) when the multimedia content ( 305 ) is embedded in the chat transcript ( 240 ). Either the audio transcript file or the multimedia content file, or both, may include a tag linking to the other. For example, the tag may include key words relating to the multimedia content ( 305 ), or it may contain the title name of the multimedia content ( 305 ). By linking the files together, the files may be found simultaneously when the user searches for the multimedia content ( 305 ).
[0038] An audio transcript ( 400 ) of the multimedia content ( 305 ) may also be created by the user who creates the multimedia content ( 305 ). Doing so may take more time than a speech-to-text conversion process, but it may also allow the user to highlight the most important aspects of the multimedia content ( 305 ) by creating a simple outline of the content. This may be particularly helpful when referring back to the transcript to find the most important details of the exchange. The manually created audio transcript ( 400 ) may be sent in addition to an automatically generated audio transcript ( 400 ) so that the most important aspects as well as the finer details of the exchange may both be found relatively easily.
[0039] According to another embodiment, the instant messaging exchange may be configured to send the user-generated multimedia content ( 305 ) in several different files or sections. This may be useful with slower connections or with very long recordings, so that the user receiving the multimedia content ( 305 ) is able to see portions of the content before all of the content is completely finished downloading. In other embodiments, the multimedia content ( 305 ) may be played back through an established streaming channel. The streaming channel may be established when the chat connection is first established, when the user first begins recording the multimedia content ( 305 ), or when the user finishes recording the multimedia content ( 305 ). The streaming channel may also be setup to play the multimedia content ( 305 ) in real-time as the content is downloaded, or on a buffered delay. The instant messaging client may provide options for changing the properties of the recording or the playback, including playback size and quality.
[0040] Referring now to FIG. 5 , a flowchart showing an illustrative method ( 500 ) for incorporating user-generated multimedia content in an instant messaging exchange is shown. The method ( 500 ) includes providing ( 505 ) an instant messaging client configured to establish a connection between a first messaging device ( 105 , FIG. 1 ) and a second messaging device ( 110 , FIG. 1 ) in a network ( 115 , FIG. 1 ). As previously mentioned, the instant messaging client ( 200 , FIG. 2 ) may be a stand-alone program for use with an operating system, or the client may be an in-browser client for use in a particular website, for example. When the connection has been established the users at each of the messaging devices may engage in a real-time conversation through the use of the client.
[0041] The method further includes recording ( 510 ) user-generated multimedia content in a recording interface ( 225 , FIG. 2 ) of the instant messaging client at the first messaging device. The recording interface may be part of the original client interface window, or the recording interface may be opened in a separate window. The user-generated multimedia content may be any multimedia content, including video and audio, produced by the user, rather than by a third party.
[0042] After recording the user-generated multimedia content, the first messaging device sends ( 515 ) the content to the second messaging device. The multimedia content ( 305 , FIG. 3 ) is displayed in the client on both messaging devices and may be in chronological order of entry with the rest of the text of the conversation.
[0043] The multimedia content may be played in the client either automatically upon receipt or upon request by the user. The client may have playback options which allow the users to determine how the content is played, for example, whether the content is played automatically or upon request, or whether the content is streamed or downloaded before playing, among other options. Playback may also be based on at least one policy rule. Such a policy rule may depend on one or more factors, including, but not limited to, the identity of the remote user (user at the second messaging device), location of the users, time of day, and ambient noise measurements. For example, if the ambient noise measurements at one or both of the messaging devices are too loud, the automatic playback may not be effective if the output sound level of the multimedia content is not sufficiently loud so as to be heard over the ambient noise.
[0044] The instant messaging client may apprise the first user of the existence and status of any policy rules which may be in effect at each of the messaging devices. This may help the first user to avoid recording something that should not be played automatically, such as sensitive information that should not be played back in a public area. The second user may also be at a messaging device attached to a public network, rather than a private network, which may also adversely compromise the privacy of the conversation. Consequently, if the policy rule defines that the content not be automatically played over a public network, the second user may need to request that the content be played back by pressing a play button or similar request. According to one embodiment, the first user may be able to override the policy rule. The override may be a manual override accomplished by setting a flag that dictates whether or not certain content should be played automatically. Alternatively, the override may be due to another policy rule or meta policy rule based on a broad set of policies.
[0045] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
[0046] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0047] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
[0048] Having thus described the invention of the present application in detail and by reference to embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
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A method for displaying multimedia content created by a user of a first computerized messaging device to a user of a second computerized messaging device communicatively coupled to the first computerized messaging device by a network includes: displaying, with the second computerized messaging device, a textual instant messaging exchange between the user of the first computerized messaging device and the user of the second computerized messaging device; receiving the multimedia content at the second computerized messaging device over the network; and dynamically embedding a player for the multimedia content in-line in the display of the textual instant messaging exchange at the second messaging device.
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RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 60/978,336, filed Oct. 8, 2007, the entire disclosure of which is incorporated herein by reference.
TECHNICAL FIELD
The present invention pertains generally to medical devices and more particularly to medical devices such as sphincterotomes.
BACKGROUND
In procedures such as endoscopic sphincterotomy, a sphincterotome may be used in conjunction with an endoscope to provide surgical cutting inside of a patient. Exemplary sphincterotomes are disclosed in commonly assigned U.S. Pat. Nos. 5,547,469 and 5,868,698 to Rowland et al., the disclosures of which are incorporated herein by reference. The sphincterotome may, for example, be used to partially cut open the sphincter muscle for treatment such as removal of common bile duct stones forming an obstruction. A sphincterotome may include a cutting wire that can be activated by bending the sphincterotome, thereby permitting the cutting wire to extend from the sphincterotome.
However, when activating the cutting wire, it may be difficult to control the exact positioning of the cutting wire. In some instances, it may be desirable to position the activated cutting wire in an angular configuration commonly referred to in the art as the “12 o'clock” position, or in any other desirable angular configuration.
There remains a need, therefore, for an improved sphincterotome that is configured such that, when activated, the cutting wire assumes a desired cutting position at or near the “12 o'clock” position, or any other desired angular configuration. A need remains for an improved sphincterotome with controlled bending characteristics.
SUMMARY
The invention pertains to an improved sphincterotome that is configured such that, when activated, the cutting wire assumes a desired cutting position at or near the “12 o'clock” position or any other desired angular configuration. In some cases, activating the cutting wire may include application of an electrical current, but this is not required. The invention pertains to an improved sphincterotome having controlled bending characteristics.
Accordingly, an illustrative but non-limiting example of the invention may be found in a sphincterotome having an elongate shaft and a cutting element lumen extending through the elongate shaft. A micromachined hypotube may be disposed within a distal region of the elongate shaft. A cutting element may be disposed within the cutting element lumen such that an exposed portion of the cutting element is disposed exterior to the micromachined hypotube.
Another illustrative but non-limiting example of the invention may be found in a sphincterotome that is movable between a cutting position and a non-cutting position. The sphincterotome includes an elongate shaft that defines a cutting wire lumen extending within the elongate shaft. A cutting wire may be disposed within the cutting wire lumen. The sphincterotome includes apparatus or structure disposed exterior to the elongate shaft that is configured to limit a bending plane of the elongate shaft.
Another illustrative but non-limiting example of the invention may be found in a sphincterotome that has an elongate shaft that defines a cutting wire lumen. A cutting wire may be disposed within the cutting wire lumen. A distal region of the elongate shaft may be configured to have a greater flexibility in an activating bending plane and a lesser flexibility in an orthogonal bending plane.
The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The Figures, Detailed Description and Examples which follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
FIG. 1 is a view of a sphincterotome in accordance with an illustrative but non-limiting example of the invention;
FIG. 2 is a cross-sectional view taken along line 2 - 2 of FIG. 1 ;
FIG. 3 is a cross-sectional view taken along line 3 - 3 of FIG. 1 ;
FIG. 4 is a view of a micromachined hypotube that may be incorporated into the sphincterotome of FIG. 1 , in accordance with an illustrative but non-limiting example of the invention;
FIG. 5 is a top view of a distal portion of the sphincterotome of FIG. 1 , incorporating the micromachined hypotube of FIG. 4 in accordance with an illustrative but non-limiting example of the invention; and
FIG. 6 is a side view of a distal portion of the sphincterotome of FIG. 1 , incorporating the micromachined hypotube of FIG. 4 in accordance with an illustrative but non-limiting example of the invention, shown in a curved configuration.
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
DETAILED DESCRIPTION
For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.
All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the terms “about” may include numbers that are rounded to the nearest significant figure.
The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
The following description should be read with reference to the drawings wherein like reference numerals indicate like elements throughout the several views. The drawings, which are not necessarily to scale, depict illustrative embodiments of the claimed invention.
The present invention generally pertains to a sphincterotome 10 , as illustrated in FIG. 1 . The sphincterotome 10 can be seen as including a proximal section 12 and a distal section 14 . A handle 16 is disposed within the proximal section 12 and an elongate shaft 18 extends distally therefrom. The handle 16 may be formed of any suitable metallic or polymeric material, such as those discussed hereinafter. The elongate shaft 18 itself has a distal region 20 defining a distal end 22 and a proximal region 24 defining a proximal end 26 . In some instances, it is contemplated that part of the elongate shaft 18 may undergo processing that may impart a curve or bias thereto, although this is not required. The elongate shaft 18 may be formed of or include any suitable polymeric material. In some cases, the elongate shaft 18 may include portions made from or including polytetrafluoroethylene, better known as TEFLON®.
A hub 26 may be disposed within the proximal region 24 of the elongate shaft 18 . In some instances, if desired, the hub 26 may include a first hub portion 28 having a side port 30 that may be used to gain fluid access to an interior of the elongate shaft 18 . The hub 26 may also include a second hub portion 32 that may, if desired, provide guidewire access to the interior of the elongate shaft 18 via a guidewire port 34 that is provided within the second hub portion 32 . The elongate shaft 18 can be seen as extending distally to a distal end 22 of the elongate shaft 18 . The elongate shaft 18 may be considered as including the hub 26 , first hub portion 28 and second hub portion 32 . The hub 26 and defined portions thereof may be formed of any suitable polymeric material.
As noted, the elongate shaft 18 includes an interior. FIGS. 2 and 3 , which are cross-sections taken through the elongate shaft 18 , provide illustrative but non-limiting examples of an interior of the elongate shaft 18 . In FIG. 2 , which is taken through a relatively proximal portion of the elongate shaft 18 , it can be seen that the elongate shaft includes a first lumen 36 and a second lumen 38 . In some instances, the elongate shaft 18 may include only one lumen, or may include three or more lumens.
In the illustrated embodiment, the first lumen 36 may, for example, be a guidewire lumen in communication with the guidewire port 34 disposed within hub 32 . The second lumen 38 may, if desired, accommodate a cutting element 40 . The cutting element 40 may extend from the handle 16 to a position within the distal region 20 of the elongate shaft 18 . In some instances, the cutting element 40 may be a cutting wire, as known in the art. In some cases, the cutting element 40 may be a stranded or braided wire.
FIG. 3 is a cross-section taken through a relatively distal portion of the elongate shaft 18 . In this view, only a single lumen 42 is present. In some cases, the first lumen 36 and the second lumen 38 may merge into a single lumen 42 . In some cases, the second lumen 38 (through which the cutting element 40 is disposed) may terminate at a position proximal of where this cross-section is taken as the cutting element 40 itself may extend external to the shaft or terminate proximal of the cross-section point. In other cases, the elongate shaft 18 may include one, two, three or more lumens that extend all the way to the distal end 22 of the elongate shaft 18 . In some cases, the elongate shaft 18 may be configured to provide rapid exchange capability and thus may include a short guidewire lumen (not illustrated) extending through a distal portion of the elongate shaft 18 .
Returning to FIG. 1 , it should be noted that the cutting element 40 (seen in FIG. 2 ) has a distal end (discussed later with respect to FIGS. 5 and 6 ) and a proximal end 44 . In some cases, the proximal end 44 may be secured to the handle 16 . More particularly, the handle 16 may include a stationary portion 46 and a movable portion 48 . The stationary portion 46 may be secured to the elongate shaft 18 while the proximal end 44 of the cutting element 40 may be secured to the movable portion 48 . The movable portion 48 may be slidingly disposed on the stationary portion 46 .
The stationary portion 46 may, if desired, include a thumb ring 50 while the movable portion 48 includes one or more finger rings 52 . Thus, a physician or other professional may activate the sphincterotome 10 by holding the thumb ring 50 in his or her thumb and using their fingers to pull the finger rings 52 (and thus the movable portion 48 ) proximally.
The handle 16 may also, if desired, include a connector block 80 that may be used to provide communication between the cutting element 40 and a RF heating source, as is known in the art, in order to energize the cutting element 40 .
The distal region 20 of the elongate shaft 18 may, as illustrated, include one or more marker bands 54 . The marker bands 54 , if present, may be formed of any suitable radiopaque material and may have any appropriate dimensions and/or axial spacing, as desired. In some cases, the marker bands 54 may be visually evident during use, and therefore in some instances, the marker bands 54 may not be formed of a radiopaque material but may instead simply be applied using a material of a different color. The marker bands 54 may aid in positioning the sphincterotome 10 during a procedure.
The distal region 20 of the elongate shaft 18 also includes elements not expressly illustrated in FIG. 1 . In particular, FIG. 4 provides a view of a micromachined hypotube 56 that may be disposed within or about at least a portion of the distal region 20 of the elongate shaft 18 . The micromachined hypotube 56 has a proximal portion 58 defining a proximal end 60 and a distal region 62 defining a distal end 64 . The micromachined hypotube 56 has a first side 66 and a second side 68 . The first side 66 may include a first plurality of slots 70 while the second side 68 includes a second plurality of slots 72 . At least some of the first plurality of slots 70 may be parallel. At least some of the second plurality of slots 72 may be parallel.
Each of the first plurality of slots 70 and each of the second plurality of slots 72 extend only partially around the circumference of the micromachined hypotube 56 . In some instances, as illustrated, each of the first plurality of slots 70 and each of the second plurality of slots 72 are at least substantially equally sized in length and width, and start and stop along common lines. While not illustrated, it is contemplated that the relative axial spacing and/or width of some of the slots within the first plurality of slots 70 and/or the second plurality of slots 72 may vary in order to provide customized flexibility control.
It can be seen that the micromachined hypotube 56 will have a greater flexibility in a first bending plane in which, for example, at least some of the first plurality of slots 70 open while at least some of the second plurality of slots 72 close. Conversely, the micromachined hypotube 56 will have a reduced flexibility in a second bending plane that is orthogonal to the first bending plane. It can be seen that the first bending plane may be referred to as an activating bending plane while the second bending plane might be referred to as an orthogonal bending plane.
Each slot within the first plurality of slots 68 and the second plurality of slots may be formed to be at least largely rectangular in shape. In some instances, at least some of the slots may not extend all the way through micromachined hypotube 56 . Each slot may be formed using any suitable technique, such as saw cutting, a laser, or even by electrical discharge machining (EDM). Additional suitable techniques include chemical etching and abrasive grinding.
The micromachined hypotube 56 may be formed of any suitable polymeric or metallic material. In some cases, the micromachined hypotube 56 may be formed of a suitably stiff polymer such as carbon fibers, liquid crystal polymers, polyimide, and the like. In some instances, the micromachined hypotube 56 may be formed of a metallic material such as stainless steel or a nickel-titanium alloy such as Nitinol or other metallic or polymeric shape-memory material. The micromachined hypotube 56 may include a combination of metal tubes and polymer tubes, if desired. In some cases, the micromachined hypotube 56 may be formed as an integral part of the elongate shaft 18 , or in some instances, the slots may instead be formed within the elongate shaft 18 itself.
The micromachined hypotube 56 may be formed having any desired length, width, material thickness, and slot size as required to satisfy the requirements of any particular application. Additional details concerning micromachined hypotube 56 , including the manufacture thereof, can be found, for example, in U.S. Pat. No. 6,766,720 and U.S. Patent Publication No. 2004/0181174A2, each of which are incorporated by reference herein to the extent that they do not conflict with the present disclosure.
FIGS. 5 and 6 clarify operation of the sphincterotome 10 . In FIG. 5 , the micromachined hypotube 56 has been disposed about or within the distal region 20 of the elongate shaft 18 . In some cases, the micromachined hypotube 56 may be disposed about an exterior of the elongate shaft 18 . If desired, and to electrically isolate the micromachined hypotube 56 from the cutting element 40 , a polymeric coating or sheath may be applied to the micromachined hypotube 56 . In some instances, the micromachined hypotube 56 may be molded within the polymeric or other material forming the elongate shaft 18 , as desired.
The cutting element 40 includes an exposed cutting portion 74 that extends from a distal end 76 of the cutting element 40 to a port 78 disposed within the elongate shaft 18 . As illustrated, the distal end 76 of the cutting element 40 is secured directly to the distal region 62 of the micromachined hypotube 56 . In some cases, it is contemplated that the cutting element 40 could instead pass through an aperture (not illustrated) or rest within a slot or channel within the micromachined hypotube 56 such that the distal end 76 of the cutting element 40 could instead be anchored directly to the elongate shaft 18 .
As noted previously, the cutting element 40 extends proximally to the handle 16 . The port 78 is an aperture formed within the wall of the elongate shaft 18 and may, if desired, include reinforcing structure (not illustrated). In FIG. 5 , the exposed cutting portion 74 can be seen to be in a non-cutting position in which the exposed cutting portion 74 of the cutting element 40 is at least substantially parallel with the elongate shaft 18 .
In FIG. 6 , however, the exposed cutting portion 74 of the cutting element 40 is in a cutting position in which the exposed cutting portion 74 of the cutting element 40 has pulled away from the elongate shaft 18 as a result of proximal movement of the movable portion 48 relative to the stationary portion 46 . It can be seen that the micromachined hypotube 56 provides at least part of the distal region 20 with a smooth curvature that is free of kinks.
As discussed above, the micromachined hypotube 56 is configured to be more flexible in a first bending plane and less flexible in a second, orthogonal bending plane. The micromachined hypotube 56 may be secured to the elongate shaft 18 oriented in such a way that when a tensile force is applied to the cutting element 40 , the first bending plane corresponds to the “12 o'clock” direction. As a result, the sphincterotome 10 will reliably or predictably bend in a desired direction.
In some instances, it is contemplated that the cutting element 40 may not actuate in exactly a desired direction or plane. This may occur, for example, as a result of manufacturing tolerances, interference from the anatomy, influence from an endoscope, and the like. Nevertheless, the sphincterotome 10 will, as a result of micromachined hypotube 56 , reliably and repeatedly bend in a desired plane.
The devices described herein may include a variety of different materials. These materials may include metals, metal alloys, polymers, metal-polymer composite, and the like, or any other suitable material. Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic or super-elastic nitinol, nickel-chromium alloy, nickel-chromium-iron alloy, cobalt alloy, tungsten or tungsten alloys, MP35-N (having a composition of about 35% Ni, 35% Co, 20% Cr, 9.75% Mo, a maximum 1% Fe, a maximum 1% Ti, a maximum 0.25% C, a maximum 0.15% Mn, and a maximum 0.15% Si), hastelloy, monel 400, inconel 825, or the like; other Co—Cr alloys; platinum enriched stainless steel; or other suitable material.
Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, for example, DELRIN® available from DuPont), polyether block ester, polyurethane, polypropylene (PP), polyvinylchloride (PVC), polyether-ester (for example, ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (for example, butylene/poly(alkylene ether) phthalate and/or other polyester elastomers such as HYTREL® available from DuPont), polyamide (for example, DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide/ethers, polyether block amide (PEBA, for example available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low density polyethylene (for example REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly paraphenylene terephthalamide (for example, KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers thereof, polymer/metal composites, and the like.
In addition, the devices described herein may also be doped with or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids the user of filtering device in determining their location. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, molybdenum, palladium, tantalum, tungsten or tungsten alloy, plastic material loaded with a radiopaque filler, and the like.
The invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention as set out in the attached claims. Various modifications, equivalent processes, as well as numerous structures to which the invention can be applicable will be readily apparent to those of skill in the art upon review of the instant specification.
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A sphincterotome including a cutting wire may be configured such that, when activated, the cutting wire assumes a desired cutting position at or near the “12 o'clock” position or any other desired angular configuration. A sphincterotome may have controlled bending characteristics. A distally located micromachined hypotube may, in some instances, provide desired bending characteristics to a sphincterotome.
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BACKGROUND
[0001] Natural methane (CH 4 ) emissions have gained much attention over the past few decades due to the importance of methane as a potent greenhouse gas. Methane's lifetime in the atmosphere is much shorter than carbon dioxide (CO 2 ), but CH 4 is more efficient at trapping radiation than CO 2 (i.e., pound for pound, the comparative impact of CH 4 on climate change is over 20 times greater than CO 2 over a 100-year period). Methane is emitted by natural sources such as wetlands, as well as human activities such as leakage from natural gas systems and the raising of livestock. In 2012, CH 4 accounted for about 9% of all U.S. greenhouse gas emissions from human activities (http://epa.gov/climatechange/ghgemissions/gases/ch.4.html#content). Of the various sources for natural methane emissions identified, the wood-feeding termite group is arguably the most significant, to the point where termites have been reported to be the largest source of greenhouse gases (methane) emissions on the planet Earth.
[0002] Bacterial methanogenesis is a ubiquitous process in most anaerobic environments. There are three major substrates used by methanogens to produce methane: i) CO 2 , ii) compounds containing a methyl group, or iii) acetate. The association of bacterial methanogenesis with anaerobic decomposition of organic matter in microbial habitats such as the intestinal tract of animals, sewage, sludge digester, muds of various aquatic habitat etc., has been well established. Thus, gas production commonly observed in nature is mainly the result of the growth of methanogens under specific energy sources that were formed as a result of microbial decomposition of organic matter.
[0003] Methanogens belong to the domain Archaea. The diversity of archaea found in the rumen of many organisms has been reviewed by many researchers. Most archaea identified in the rumen of animals belong to known methanogen clades with a predominance of Methanobrevibacter spp. The pooled data from several surveys show that the Methanobrevibacter clade accounts for nearly two-thirds of rumen archaea. The remaining one-third was composed, of roughly equal parts by phylotypes belonging to methanomicrobium and the rumen cluster C.
[0004] Most rumen methanogens do not contain cytochromes and although they are less efficient at obtaining energy through the production of methane than their cytochrome-containing relatives of the order methanosarcinales, they are better adapted to the environmental conditions prevailing in the rumen. They have a lower threshold for hydrogen (H 2 ) partial pressure, a faster doubling time, that can be as short as 1 h, and they have the potential to develop better at the mesophilic temperature and the near neutral pH of the rumen.
[0005] Termites are eusocial insects that belong to the order isoptera and play a major role in tropical ecosystem. Their basic food is plant matter, both living and dead. The main diet of most of the termite species consists of wood, foliage, humus or a mixture of these foods. It is not known whether isopteran have a significant role in rumen methanogenesis but methanogens attached to the gut epithelium have been described in termites, and in such a microaerobic environment they are capable of producing methane and reducing oxygen at the same time.
[0006] Termites are divided into two groups, i) lower termites, and ii) higher termites. Lower termites is a group of six evolutionary distinct termite families (the microbial community in the gut of phylogenetically lower termites) comprising both flagellated protists and prokaryotes. This group includes approximately 85% of all termite species that also harbors a dense and diverse population of gut prokaryotes that typically lack eukaryotic flagellated protists. Higher termites secrete their own digestive enzymes and are independent of gut microorganisms in their nutrition. The lower termites also possess this ability, but their production of cellulolytic enzymes is apparently inadequate. Hence, lower termites mostly depend on the activity of gut microorganisms for their nutrition, which are present in the hind gut region. Methanogens play a crucial role in this community of gut microbiota: if methanogens are disrupted or impeded the ecology of the system fails and the host organism will suffer.
[0007] Methanogenesis is an important component of microbial carbon metabolism in the hind gut termite digestive system. Methanogenic bacteria share physiological and biochemical characters such as ability to anaerobically oxidize hydrogen and reduce carbon dioxide to methane. One of the most fascinating nutritional symbioses exists between termites and their intestinal microflora: a symbiosis that permits termites to live by xylophagy, or the consumption of wood. The termite gut represents an excellent model of highly structured micro-environments. Apart from its natural role of conversion of woody and cellulosic substances into useful products of termite gut, microbiota contribute significantly to greenhouse gas effect through methane generation.
[0008] FIG. 1 illustrates a gut of a termite and reaction chains that are taking place therewithin. The adult termite gut consists of fore gut (which includes the crop and muscular gizzard), the tubular mid gut (which as in other insects is a key site for secretion of digestive enzymes and for absorption of soluble nutrients) and relatively, a voluminous hindgut (which is also a major site for digestion and for absorption of nutrients). The morphological diversity of the termite gut microbiota is remarkable and has been documented for both lower and higher termites. Although some bacteria colonize the foregut and midgut, the bulk of intestinal microbiota is found in the hindgut, especially in the paunch, which is, the region immediately posterior to the enteric valve. The hindgut compartments harbor the bulk of the intestinal microbiota. These tracts were initially considered as ‘fermentation chambers’ analogous to the rumen of sheep and cattle (e.g. anoxic environments for an anaerobic, oxygen-sensitive microbiota).
[0009] Researchers have reported that arthropod gut provides a suitable niche for microbial activity, but the nature of microflora and their distribution depended on the physicochemical conditions like pH, redox potential and temperature of that region. Further research supported that the presence of large number of aerobic, facultative and anaerobic microflora showed that hindguts are a purely anoxic environment together with steep axial pH gradients in higher termites. Among the different physiochemical conditions, pH and redox potential are the important factors which determine the type of microflora in the gut, while the pH of the foregut and midgut is around neutrality, whereas the paunch, colon and rectum appear to be slightly acidic.
[0010] FIG. 2 identifies known reductive reactions that occur in the gut of the termites. The most important metabolic activities traditionally attributed to the gut microbiota are, first, hydrolysis of cellulose and hemicelluloses, second, fermentation of the depolymerization products to short-chain fatty acids, which are then resorbed by the host, and third, intestinal nitrogen cycling and dinitrogen fixation. In the phylogenetically lower termites, a large fraction of hindgut volume (up to one-third of the body weight of a termite) is occupied by anaerobic flagellates, which phagocytize and degrade the wood particles comminuted by the termite. The phylogenetically higher termites do not harbor flagellates within their gut. Instead, an acquisition of cellulases with the food (in case of the fungus-cultivating termites) or a host origin of the cellulolytic activities has been suggested.
[0011] FIG. 3 illustrates a carbohydrate metabolism in wood and litter feeding termites. Termites are good sources of wood degrading enzymes such as cellulase-free xylanase, laccases that are potentially involved in phenolic compounds degradation suitable for paper and pulp industry and glucosidases. The metagenomic analysis of hindgut microbiota of higher termite shows the presence of diverse endoxylanases, endoglucanases, phosphorylases, glucosidases, nitrogenases, enzymes for carbon dioxide reduction and enzymes used in new ways for producing lignocelluloses based biofuels production and acetate production. Daily hydrogen turnover rates were 9-33 m 3 H 2 per m 3 hindgut volume, corresponding with the 22-26% respiratory activity of the termites. This makes H 2 the central free intermediate during lignocellulose degradation and the termite gut, with its high rates of reductive acetogenesis, the smallest and most efficient natural bioreactor currently known.
[0012] Termites inhabit many different ecological regions, but they are concentrated primarily in tropical grasslands and forests. Symbiotic micro-organisms in the digestive tracts of termites (flagellate protozoa in lower termites and bacteria in higher termites) produce methane. Termites emit large quantities of methane, carbon dioxide and molecular hydrogen into the atmosphere. Significant studies have been performed on diversity, social structure, physiology and ecology of the termites as source of methane contributing to the sources of atmospheric greenhouse gas. Methane production by termites was first reported by Cook (1932) who observed the evolution of a gas from a species of termite.
[0013] FIG. 4 illustrates the results of studies showing large variations in amount of methane produced (in a termite's digestive track during the breakdown of cellulose by symbiotic micro-organisms) for different species. Research also found average methane production rates of 0.425 μg CH 4 /termite/day for the lower termite species and 0.397 μg CH 4 /termite/day for the higher termite families. Environmental conditions such as light levels, humidity, temperature, as well as carbon dioxide and oxygen presence play a key part in methane production. Termites prefer the absence of solar radiation, an immobile atmosphere, saturated or nearly saturated, relative humidity, high and stable temperatures and even elevated levels of carbon dioxide. Although termite populations are active in the middle latitude environments, the vast concentrations of mounds and nests are found in the lower latitude tropical forests, grasslands and savannahs of Africa, Asia, Australia and South America. It is estimated that these regions contribute approximately 80% of global termite emissions.
[0014] Researchers performed laboratory experiments using termite mounds under glass enclosures, with varying diet patterns and temperatures, while all other variables remained stable. It was found that the capacity of termites to produce methane varied from species to species, within groups from different mounds or nests of a particular species. But all species produced methane which indicates that methanogens are active components of their biology. The six different species studied produced methane at rates that ranged over more than two orders of magnitude. Raising the temperature by 5° C. within each species' caused a 30-110% increase in the measured methane emissions. Prior laboratory and field research seems to show that termites preferred temperatures in excess of 10° C. above the ambient air temperatures, determined by their geographical locations. A positive correlation between amounts of biomass consumed and methane emitted was observed, with the average being 3.2 mg CH 4 per gram of wood.
[0015] Methanogenic bacteria have been associated with protozoa in termites. Though methanogens are generally strict anaerobes, their metabolic responses to the presence of oxygen and their sensitivity to it vary with the species. Methanobacterium sp. was isolated from the termite hindgut. Methanobrevibacter cuticulam and M. curvatus were isolated from the hindgut of the termite Reticulitermes flaviceps. The presence of M. arboriphilicus and Methanobacterium bryantii in the guts of wood eating higher termites has also been reported.
[0016] Termite guts are the world's smallest bioreactors. The presence of carbohydrate-fermenting bacteria and protozoa, high levels of volatile fatty acids in the gut fluid and the occurrence of typical anaerobic activities such as homoacetogenesis and methanogenesis resemble the situation encountered in the rumen of sheep and cattle.
[0017] Methane is a metabolic end product in the hindgut of most termites. It has been estimated that these insects contribute approximately 2 to 4% to the global emissions of this important greenhouse gas. Methanogenic archaea, which are easily identified by their coenzyme F 420 autofluorescence, have been located in several microhabitats within the hindgut. Depending on the termite species, these organisms can be associated either with the hindgut wall or with filamentous prokaryotes attached to the latter, or they can occur as ectosymbionts or endosymbionts of certain intestinal flagellates.
[0018] FIG. 5 illustrates annual emissions of methane and carbon dioxide in the atmosphere by termites as calculated by various researchers. The annual emission rates of methane and carbon dioxide were estimated by researchers using the equation P=C Σ n 1=1 A i B i F i where, P is the annual emission of the trace gas (in grams), A i is the area of an ecological region (in square meters), B i is the biomass of termites in that region (in grams per square per square meter) and F i is the flux of the trace gas (in grams of gas per grams of termites per hour).
[0019] FIG. 6 illustrates a termites life cycle. As a xylophagous termite grows and develops, methanogens clearly play an integral role in the reproduction, growth, development and overall activity of the organism. The microbes play similar roles in the life-cycles of other wood-boring insects and cellulose consumers such as xylophagous beetles.
[0020] A series of termite control methods have been implemented historically with varying measurements of success. A brief description of those techniques is presented below.
[0021] Fumigation: Fumigation (“tenting”) has been the only method used for over forty years which insures complete eradication of all drywood termites from a structure. The phase-out of methyl bromide in the U.S. has positioned sulfuryl fluoride as the leading gas fumigant. Fumigation is a highly technical procedure which involves surrounding the structure with a gas-tight tarpaulin, releasing the gas inside the seal, and aerating the fumigant after a set exposure time.
[0022] Heat: Heat treatments are used to eradicate drywood termites. During the heat treatment the infested area is cordoned off with polyethylene or vinyl sheets. Temperature probes are placed in the hardest-to-heat locations and heat is applied with a high-output propane heater. After a lethal target temperature is achieved, the area can be cooled quickly.
[0023] Cold: Excessive cold is primarily applied by using liquid nitrogen, which is pumped into the targeted area until the temperature drops to a level lethal to drywood termites. Temperature probes are used to insure that lethal temperatures are attained.
[0024] Wood Injection: Wood injection or “drill-and-treat” applications have been used since the 1920s to treat drywood termite infestations which are accessible and detectable. An insecticide is injected into small holes drilled through any wood surface into termite galleries delivering the treatment directly to the pest population. This is the simplest and most direct method of treatment. The amount of drilling required and the effectiveness of this treatment depend on the chemical used and the nature of the infestation. Most chemicals will remain active in the wood after treatment to thwart resurgent colonies.
[0025] Borates: Spray and foam applications of products containing boron salts are applied to raw, uncoated wood surfaces. Because penetration depths of borate solutions and depth of drywood termite galleries vary, injections into existing infestations are usually being performed.
[0026] Microwave: Microwave energy, applied to relatively small sections of infested wood, kills termites by heating them. Thermocouples are inserted into treated members to ensure that adequate microwave energy is delivered.
[0027] Electrocution: The probe of a hand-held “gun” is passed slowly over the infested wood surface and inserted directly into pellet “kick-out” holes. The high voltage and low current energy emitted by the probe electrocutes termites in the immediate application area. There is no way to measure a lethal dose at a given location in wood with this device. In some cases, holes must be drilled into wood and wires inserted to improve penetration.
[0028] The most common delivery methods for the targeted treatment methods are baits and sprays. The baits consist of paper, cardboard, or other palatable food, combined with a slow-acting substance lethal to termites. The bait must be “tasty” enough that termites will readily consume it, even in the presence of competing tree roots, stumps, woodpiles and structural wood.
[0029] If the bait kills too quickly, sick or dead termites may accumulate in the vicinity of the bait stations, increasing the chance of avoidance by other termites in the area. Delayed-action also enhances transmission of the lethal agent to other termites, including those that never fed on the bait. Entire colonies can be eliminated in this manner, although total colony elimination is not always necessary to afford structural protection. The lethal compounds could also be made into a spray for use on susceptible wood surfaces or surfaces exhibiting infestation where pests need to be controlled. It could also be used incorporated into a sugar solution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 illustrates a gut of a termite and reaction chains that are taking place therewithin.
[0031] FIG. 2 identifies known reductive reactions that occur in the gut of the termites.
[0032] FIG. 3 illustrates a carbohydrate metabolism in wood and litter feeding termites.
[0033] FIG. 4 illustrates the results of studies showing a large variations in amount of methane produced for different species.
[0034] FIG. 5 illustrates the annual emissions of methane and carbon dioxide in the atmosphere by termites that have been calculated by various researchers.
[0035] FIG. 6 illustrates a termites life cycle.
[0036] FIG. 7 is a table that lists the volume of biogas production, pH values, and the concentrations of COD, ORP, and TDS measured in the Control and Test reactors during the studies.
[0037] FIG. 8 is a table that lists the methane content measured in the biogas generated in the reactors during the 17-day study period.
[0038] FIG. 9 is a graph of the methane concentrations listed in FIG. 8 .
[0039] FIG. 10 is a table that lists the methane content measured in the biogas generated in the reactors during the 19-day study period.
[0040] FIG. 11 is a table that defines the tests performed for different essential oils.
[0041] FIGS. 12-14 are tables showing the results of the FIG. 11 tests for the 3 time intervals (day 3, day 7 and day 12 respectively).
[0042] FIG. 15 is a graph showing the results for the tests of FIG. 11 for the different time intervals.
[0043] FIG. 16 illustrates an example feed bait process.
DETAILED DESCRIPTION
[0044] Methane fermentation is a versatile biotechnology capable of converting almost all types of polymeric materials to methane and carbon dioxide under anaerobic conditions. This is achieved as a result of the consecutive biochemical breakdown of polymers to methane and carbon dioxide in an environment in which a variety of microorganisms which include fermentative microbes (acidogens); hydrogen-producing, acetate-forming microbes (acetogens); and methane-producing microbes (methanogens) harmoniously grow and produce reduced end-products. Anaerobes play important roles in establishing a stable environment at various stages of methane fermentation.
[0045] The methanogenic Archaea (methanogens) occupy a variety of anaerobic habitats, where they play essential roles in the conversion of hydrogen and other intermediates to methane. Most species are capable of reducing carbon dioxide (CO 2 ) to a methyl group with either a molecular hydrogen (H 2 ) or formate as the reductant. Methane production pathways in methanogens that utilize CO 2 and H 2 , involve specific methanogen enzymes, which catalyze unique reactions using unique coenzymes.
[0046] Several cofactors are involved in biological methane formation. Coenzyme B (HS-CoB, 7-mercaptoheptanoylthreonine phosphate) and coenzyme F 420 (a 5-deazaflavin derivative with a mild point potential of −360 mV) function as electron carriers in the process of methanogenesis. F 420 is the central electron carrier in the cytoplasm of methanogens, which replaces nicotinamide adenine dinucleotides in many reactions.
[0047] Methanogenesis from H 2 +CO 2 , formate, methylated C 1 -compounds and acetate, proceeds by a central, and in most parts reversible pathway. When cells grow on CO 2 in the presence of molecular hydrogen, carbon dioxide is bound to methanofuran (MFR) and then reduced to formyl-MFR. This endogenic reaction is driven by the electrochemical ion gradient across the cytoplasmic membrane. In the next step the formyl group is transferred to H 4 MPT and the resulting formyl-H 4 MPT is stepwise reduced to methyl-H 4 MPT. Reducing equivalents are derived from reduced F 420 (F 420 H 2 ), which is produced by the F 420 -reducing hydrogenase using hydrogen as a reductant. Furthermore, F 420 H 2 is the electron donor for F 420 H 2 -dependent methylenetetrahydromethanopterin dehydrogenase (Mtd), one of two enzymes that reduce methenyl-H4MPT. The other enzyme, H 2 -dependent methylenetetrahydromethanopterin dehydrogenase (Hmd), uses H 2 directly. mRNA abundance for mtd increased markedly under hydrogen-limited growth conditions, suggesting that Mtd may be more important when H 2 is limiting.
[0048] Sharma et al. (2011) determined a 3D model structure of the F 420 -dependent NADP oxidoreductase enzyme from M. smithii. Based on their protein model, they detected that these residues are making a ligand binding site pocket, and they found that ligand F 420 binds at the protein cavity. The inhibitor compounds lovastatin and compactin (mevastatin) show more affinity for the model protein as compare to the natural ligand F 420 . They share the same cavity as by F 420 and surround by similar residues. Therefore, the inhibitor compounds lovastatin and compactin (mevastatin) were very effective in blocking the activity site for methane production since the enzyme was unable to bind with the substrate, resulting in decreased methane production.
[0049] Monacolin K, as an example statin, can also inhibit methanogenic archaea because cell membrane production in archaea shares a similar pathway with cholesterol biosynthesis (Miller and Wolin, 2001). More specifically, bacterial cell walls are predominantly comprised of murein (peptidoglycan). Archaea, however, do not produce murein; rather, their cell walls are composed of various sulfated-heteropolysaccharides, proteins and glycoproteins/lipids along with pseudomurein—a structural analogue of murein—which is biosynthesized via activity similar to that of HMG-CoA reductase which yields cholesterol in humans.
[0050] In the presence of a statin, HMG-CoA reductase is inhibited, pseudomurein biosynthesis pathway is interrupted, and methanogens are restricted from growth and proliferation. And since methanogens are so uniquely different than bacteria, the inhibitory effect of statins is not observed in microbes.
[0051] The compound 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, is another enzyme that is very critical in methane production, and Archaea are the only bacteria known to possess biosynthetic HMG-CoA reductase (Miller and Wollin, 2001). Garlic oil has been hypothesized to inhibit the biosynthesis of HMG-CoA (Busquet et al., 2005; Fraser et al, 2007). At higher concentrations, various essential oils have exhibited wider range anti-microbial activity so the dosage and applications strategies are wide and variable.
[0052] Anti-methanogenic compounds are compounds designed to inhibit methane production in environments where methanogens are established and active. It is believed that anti-methanogenic compounds could inhibit the methane production in the gut of termites and other wood-boring and cellulose digesting pests. Limiting the production of methane causes dysfunctioning of the pests' digestive system thus impeding their growth and development. The impediment of their growth and development would thus make this an effective non-toxic method of controlling termites and other similar pests.
[0053] Anti-methanogenic compounds may include one or more unique compounds that either alone or in combination with one another effect the production of methane. Red yeast rice is believed to be an anti-methanogenic compound. In order to determine the effectiveness of red yeast rice for inhibiting methane, two bench scale studies were performed.
Laboratory Study 1
[0054] Two anaerobic reactors were utilized, a control and a test reactor. The two reactors were seeded with biomass treating expired dietary supplement, which contained an active methanogenic population. The reactors were fed once per week, and were operated as anaerobic sequencing batch reactors.
[0055] During the first week of startup, the reactors contained only the methanogenic culture, without soil. After one week, silty sand was added, resulting in a slurry having a solids concentration of 20% by weight. The reactors were operated for another week with the silty sand, to ensure that the sand did not affect methanogenic activity. The bioreactors were 2.5 L in volume, containing 2 L of slurry. The reactors were airtight and were especially designed for anaerobic reactions. The reactors were maintained at laboratory temperature 22° C.-24° C. The reactors were operated by feeding with dietary supplement once a week. The target initial chemical oxidation demand (“COD”) concentration after feeding was 2000 mg/L.
[0056] Throughout the week, the volume of biogas produced was measured as follows. A syringe was inserted periodically into a septum-filled port in the top of the reactor to collect a gas sample for methane content. The methane content of the biogas samples was then quantified by injecting into a gas chromatograph with a flame ionization detector (GC-FID). The reactors had dedicated probes to measure pH and oxidation reduction potential (“ORP”). After each cycle (i.e., before feeding), a probe was inserted into the reactor to measure total dissolved solids (“TDS”), and a sample was collected to measure COD. The mixer was turned off during sampling and feeding to minimize the introduction of oxygen into the reactor contents.
[0057] The test reactor was initially dosed with a 40 g/L concentration of red yeast rice. One week later the control was dosed with 20 mg/L red yeast rice.
Laboratory Study 2
[0058] Two test aliquots were prepared under a nitrogen atmosphere in a glove box as follows: (1) a 240 mL amber glass screw-cap septum bottle was filled with 100 g of dry soil (˜70 mL); (2) deoxygenated deionized water was slowly added to the soil to saturate the soil; an additional 40 mL of water was then added to the soil; and (3) manure slurry was added to yield a 1 weight percent manure dose to the soil.
[0059] Once the bottle was sealed it was removed from the glove box. The soil was kept in the dark (by wrapping with foil) at room temperature (˜22° C.). A needle connected to a polyethylene tube was pushed through the bottle septum and the tube outlet was placed in an inverted graduated cylinder in a water bath. The gas generation rate was recorded as the water was displaced over a period of 10 days.
[0060] The methane reduction trial included two sample formulations, with and without red yeast rice, for a total of 4 samples. The bottles were sampled 0.5, 1.5, 5, 12, and 19 days following the sample preparation.
[0061] Results for Laboratory Study 1
[0062] The first two weeks of the studies were the startup period, and the second two weeks were the test period. The startup period established the methanogenic population in the two reactors. During the first week of startup, the reactors were operated without the silty sand, and the second week they were operated with the silty sand (20% by weight). The test period started with the dosing of the test reactor with red yeast rice (40 g/L). During the first week of the test period the control was maintained as a proper control, with no red yeast rice added. Because the 40 mg/L dose of red yeast rice reduced methane production in the test reactor, it was decided to dose the control reactor with 20 g/L of red yeast rice during the second week of the test period. The test period lasted 17 days.
[0063] FIG. 7 is a table that lists the volume of biogas production, pH values, and the concentrations of COD, ORP, and TDS measured in the control and test reactors during the studies. The volume of biogas produced each feed cycle (i.e., each week) in the reactors ranged between 72-82 mL. It is notable that the volume of gas was not affected by the introduction of silty sand during week 2 of the startup period. The addition of 40 mg/L of red yeast rice to the test in the first week of the test period and the addition of 20 mg/L of red yeast rice during the second week of the test period did not appreciably impact biogas volume in the reactors. The COD measurements after each sequencing batch reactor cycle ranged from 56 to 108 mg/L. The reactors were fed 2000 mg/L each cycle, so the COD concentrations in FIG. 7 demonstrate that the COD was consumed by the anaerobic culture. Values of pH ranged between 6.1 and 6.4. Values of ORP were all close to −300 mV, which is typical of methanogenic conditions. The TDS in the reactors ranged from approximately 1200 to 1250 mg/L.
[0064] FIG. 8 is a table that lists the methane content measured in the biogas generated in the reactors during the 17-day test period.
[0065] FIG. 9 is a graph of the methane concentrations listed in FIG. 8 . During the Startup Period, methane concentrations varied from approximately 55% to 70%, which indicates an active methanogenic culture. The red yeast rice dose of 40 mg/L in the Test reactor reduced the methane content of biogas from 62% to below detection (0.05%) after 11 days. The methane concentration remained below detect in the Test reactor until day 17, when the reactors were dismantled. The red yeast rice dose of 20 mg/L in the Control reactor on day 7 reduced the methane content of biogas from 65% to below detection (0.05%) by day 17 (i.e., after 10 days). During the Test period, the volume of biogas produced in the Test and Control reactors did not change appreciably only the methane concentration of the biogas was changed.
Results for Laboratory Study 2
[0066] FIG. 10 is a table that lists the methane content measured in the biogas generated in the reactors during the 19-day study period. The first soil formulation (SF1) that contains 20% of the red yeast rice (approximately 40 mg/L in solution) showed great effectiveness in inhibiting the methane production by 96% during the 19-day sampling interval. Similarly at the same time fragment the second soil formulation (SF2) resulted into a 25% decrease in methane production.
[0067] The above tests clearly illustrate the effectiveness of red yeast rice in inhibiting methane. By contacting the termites with red yeast rice (e.g., having the termites digest the red yeast rice) it is believed that this would provide a green, organic and non-toxic (to humans) way to control damage and pestilence induced by wood-boring insects that harbor methanogens in order to digest or metabolize cellulose.
[0068] Utilizing organic statins (some of which can be present in red yeast rice extract as well as biomass of other organisms) may inhibit the methanogenic enzyme and coenzyme systems essential to the growth and development of wood-boring insects. Thus disrupting their digestive tracts/life-cycle stages by limiting their effectiveness in producing methane and causing dysfunctioning of the pests' digestive system thus impeding their growth and development.
[0069] Essential oils are also believed to be an anti-methanogenic compound. Laboratory studies were performed to comparatively evaluate the anti-methanogenic potential of multiple essential oils (e.g., Garlic Oil [GO], Cinnamon Bark Oil [CO], Cinnamon Bark Powder containing 4% CO [CB] and lemongrass Oil [LO]).
Laboratory Study 3
[0070] Manure and groundwater samples were collected from a site in Monticello, Wis. at 1:1 ratio. The collected samples were added to 125 mL amber glass bottles equipped with PTFE-lined open septum caps (VOA vials). The testing program included 40 vials each filled with 20 g manure slurry and 20 g groundwater. All samples were sacrificial and disposed after completion of the analyses. Five (5) vials were used to indicate the onset of anaerobic conditions by measuring pH, ORP and methane over a 2-week period.
[0071] FIG. 11 is a table that defines the tests performed. A total of 27 vials were prepared to analyze the 9 tests defined in FIG. 11 over 3 time intervals (day 3, day 7, day 12). Finally 8 vials were setup as replicate samples.
[0072] Gas samples from the sample container headspace were analyzed for methane in the gas phase using a gas chromatograph (GC) with a flame ionization detector (FID). After these analyses were completed, pH and ORP were also measured.
[0073] FIGS. 12-14 are tables showing the results of the 9 tests for the 3 time intervals (day 3, day 7 and day 12 respectively). FIG. 15 is a graph showing the results for all the tests for the different time intervals. As illustrated, it is apparent that all essential oils were successful in decreasing the amount of methane produced, with the Garlic Oil [GO] appearing to be the most effective of all.
[0074] As a termite xylophagous termite grows and develops, methanogens clearly play an integral role in the reproduction, growth, development and overall activity of the organism. The microbes play similar roles in the life-cycles of other wood-boring insects and cellulose consumers such as xylophagous beetles. As such, the anti-methanogenic compounds (e.g., red yeast rice, essential oils) could be utilized to control termites and all other wood-boring and cellulose digesting pests including but not limited to: i) the Emerald Ash Borer, ii) weevils, iii) wood-boring caterpillars ( Lepidoptera ) such as Carpenterworms ( Prionoxystus robinae ), and iv) wood-boring Bostrichidae beetles (formerly referred to as the family Lyctidae ). The socioeconomic cost and destruction caused by such organisms is significant, and a means to control them using safe, natural, sustainable means is of great benefit to society.
[0075] The anti-methanogenic materials, described herein, can be applied in a myriad of ways (feed baits, aerial applications, dustings, coatings, pellets, powders) at various stages of the targeted organisms life cycle to yield effective treatment under various scenarios. The feed baits, aerial applications, dustings, coatings, pellets, and/or powders could be applied to locations where the pests are known to inhabit or feed. According to one embodiment, the anti-methanogenic compound is incorporated into cellulose based building materials.
[0076] FIG. 16 illustrates an example feed bait process.
[0077] By controlling the activity of methanogens as disclosed, this provides a unique and important means of pest management.
[0078] It is understood that the invention is not limited to the disclosed embodiments and examples, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
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A method for inhibiting methane production in the digestive tract of methanogenic Archaea (e.g., termites, other wood boring pests). The inhibiting of the critical biochemical pathways specific to the methanogenic Archaea is achieved by having the methanogenic Archaea ingest an anti-methanogenic compound. The anti-methanogenic compound may include, for example, naturally-occurring statins or derivatives thereof, linoleic acid or related compounds, essential oils, or some combination thereof. The naturally-occurring statins can be found in the red yeast rice extract or related biomass. As a result, the effectiveness of the methanogenic Archaea to produce methane is compromised, which subsequently results into the malfunctioning of the xylophages' digestive system. This provides a safe, natural, green and sustainable means of controlling many pests such as the Asian Beetle, Emerald Ash borer, Weevils, Deathwatch Caterpillars, and termites.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a divisional application of U.S. Utility patent application Ser. No. 11/752,254 filed May 22, 2007, which application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/808,083 filed May 24, 2006.
FIELD OF TECHNOLOGY
The technology disclosed in this specification is in the field of lithographic plate management and handling for web offset printing. The technology embodies a bar coded (or other coded) apparatus and process for transporting lithographic plates to a press cylinder.
BACKGROUND
The apparatus and process for transporting lithographic plates to a press cylinder described in this specification has particular (albeit not exclusive) application to management and handling of thin, flexible, lithographic printing plates in high rotational speed press operations.
An embodiment of an apparatus for transporting lithographic plates described herein is comprised of an indexer, a pod, and a pod elevator. Another embodiment of an apparatus for transporting lithographic plates is comprised of an indexer and a cart pod.
An embodiment of the process for transporting lithographic plates to a press cylinder most often operates in conjunction with an over-arching lithographic plate management and handling system. The system directs the operation of the indexer, pod, and pod elevator. Among other duties under its control, the system codes each plate. The code contains information, which the system PLC reads at various steps along the way of preparing lithographic plates for use on a printing press. The system uses the information to direct the plate along the correct and ultimate route to the printing press, including delivering the plate to an indexer, signaling the indexer to load the plate into various pod compartments, and using a pod elevator for transporting the plates to a press cylinder.
The indexer, pod, and pod elevator may be used to load, contain, and transport lithographic plates for web-offset printing, for non web-offset printing, or for non-printing applications. The operation of the indexer, the pod, and the pod elevator is described in this specification in conjunction with computerized system. However, the indexer, pod, and pod elevator may be operated without direction from a computerized system.
The web offset printing operation is highly automated. The heart of the operation is one or more high speed presses designed for efficient mounting and removal of lithographic plates. Each plate must be precisely mounted on the press' plate-mounting cylinder to ensure that the lithographic plate image is in exact registration, i.e., “square” with the press cylinder when in the manufacturer's locked-up position.
In addition to the high rotational speed press—the hub of the operation—the printing operation must have a high speed means of management and handling of the lithographic plates. Management and handling includes identification of each lithographic plate in the system and on-time transportation of the plate to the press or presses. The means of identification and transportation of plates includes a plethora of modules, of which an indexer, pod, and pod elevator are a part. Such modules may perform (a) imaging and processing of plates, including bar coding of each plate for identification purposes; (b) image to plate registration and plate to cylinder registration; (c) plate punching, bending, shearing, corner notching/cutting; (d) direction of work flow and plate traffic routing, including optical registration verification, plate inspection, bar-code scanning, and remote diagnostics; (e) on-time delivery of plates to the press, including sorting, stacking, and conveying the plates (using, for example, plate entry modules, rotators, indexers, stackers, crossover bridges, elevators, thru-the-wall transport modules, dual highway modules, auto plate feeders, dummy plate loaders, and conveyors; (f) plate storage (in pods or on stacking cart pods), delivery of pods to storage, and rack storing of pods; and (g) automated retrieval from storage of the indexed plates. The identification and transportation of plates (and the modules which carry-out these functions) must be synchronized with one another and with the press to ensure that the plates are transported to the correct place at the correct time and the various operations on the plates are done timely and properly.
The competitive, low-margin economics of the printing business requires that the press not only be high speed, but so must the management and handling of lithographic plates. In this environment, the plate management and handling infra-structure must be fast, efficient, automated, and reliable to complement the printing process and workflow environment. The plate management and handling system employed cannot be allowed to contribute to press down time and image register problems. The system must ensure the continuous process flow of press-ready, in-register plates for each press cylinder with repeatable results.
The embodiments of the lithographic plate management and handling system of the present invention and its automated and synchronized, modular components are designed to meet these goals by integrating the entire printing workflow into one efficient system. The lithographic plate management and handling system feeds the press with the lithographic plates. The integrated system is designed to fully automate plate management and handling and reduce operator involvement in the printing process and workflow environment, whether it be in-line or off-line. Such integrated system spans the photographic process of imprinting an image on a lithographic plate to locking up the plate on the press.
The embodiments of an indexer, pod, and pod elevator and the other components of the system are all designed to automate the workflow of a printing production environment and to produce press-ready plates for applications using different levels of press technology, multiple press types, and multiple press register requirements. No one printing operation is the same, so the indexer, pod, and pod elevator and the other components of system are designed to be flexible in design and configuration. They are designed to be an integrated system with the flexibility to be custom-configured in many different ways. Moreover, the indexer, pod, and pod elevator and the other components of the system described herein range from fully automated to un-automated, depending upon the needs of a particular user application.
SUMMARY
The process for transporting lithographic plates uses an indexer to load plates into a pod compartment for delivery to a press cylinder. The plates are imprinted with a machine readable code, such as bar code. The process includes imaging and processing the plates and punching, bending, shearing, and corner notching the plates. Registration of the plate to a press cylinder occurs during imaging and bending the plate. Registration of the plates occurs when a plate can be precisely located on a press cylinder in accordance with the press manufacturer's plate lock-up specifications, including tolerances.
A conveyor moves the imaged plate to an indexer. The plates delivered to the indexer are already imaged, processed, punched, bent, sheared, and corner notched, as required, and in register. They are loaded into the indexer and the indexer moves the loaded plates into a position in alignment with designated pod compartments corresponding to bar code information. The indexer loads the plates into each of the designated pod compartment by indexed movement of the indexer's elevator to align the designated plates with each of the plates corresponding pod compartments. A pod elevator moves the pods proximate to a press cylinder where the plates are manually unloaded from the pod and loaded onto a press cylinder.
A computing device, such as a PLC, directs the process. The computing device has a memory for storing parameters corresponding to virtual locations of modules, such as a conveyor, the indexer, the pod, a pod compartment, a pod elevator, and a press cylinder. The computer stores physical locations of all of the plates at the various stages along the way to the press cylinder, machine readable codes on the plates, feedback information from the modules, and instructions for directing movement of the plates along routes based upon preset parameters. The computer includes a processor for executing the instructions, an input channel for receiving and storing the commands and the parameters, and an output channel for sending the instructions to a module for directing an operation and moving the plates along prescribed routes on a non-collision basis. A vision system is used for sensing information from a module and from a plate for feedback to a PLC, which initiates operations of a module and for bar-code scanning.
The plate indexer has a box frame, housing, elevator, indexer conveyor, plate centering assemblies, and plate finger pushers. An internal frame is secured to the box frame for support of the elevator. The elevator is vertically movable within the frame and the housing and in a first position the elevator is in a plate loading position and in a second position the elevator is in a plate exiting position. The elevator is raised and lowered by a drive motor having a worm gear assembly and a speed reduction adapter. The indexer conveyor has one or more horizontally, rollable conveyor belts and a means for rollably moving the belts. The plate centering assemblies include a means for pushing the plate into lateral registration with the belts. At least one assembly positioned on each longitudinal side of the plate. Finger pushers are mounted on each longitudinal side of the plate for gripping the plate with the finger springs and thereby move the plate into registration with the bed of the elevator. The plate assist assembly has a rodless cylinder mounted over the top of the indexer conveyor in a direction parallel to movement of the belts, a first a sensor for detecting the trailing edge of a plate and in response thereto the PLC signals the plate assist assembly to move the plate into a pod compartment and thereafter return to its start position.
The pod is a combination of a housing, partitioned compartments within the housing, a support bracket spanning the housing for rotatably mounting the pod in a pod elevator, a hangar for supporting a plate when the pod is in a vertical position within the pod elevator, a means for engaging a bend on the plate with the hangar, and a means for ejecting a plate from of the pod. The housing includes an enclosure, a retainer opposite the enclosure, the partitioned compartments between the enclosure and the retainer, and a support bracket spanning the enclosure, the compartments, and the retainer for rotatably mounting the pod in a pod elevator.
Each pod has multiple compartments, support brackets, hangars, a dual rod cylinder for engaging a bend on the plate, an ejecting for ejecting the plate. The compartments are vertically spaced apart parallel partitions. Upper pod support brackets are on an upper pod and lower pod support brackets are on a lower pod. The plates are loaded in a horizontal position. The assigned pod compartments are successively loaded with corresponding coded plates by incremental movement of the indexer elevator.
The pod elevator employed swivels the pods and their contained plates into a vertical position and transports the pods in a pod elevator proximate to a press cylinder. The support brackets have apertures for rotatable engagement with a pivot shaft of the pod elevator. A signal is sent to open a pod door, eject the plate from a designated pod compartment, and upon reaching the end of a plate ejector's travel retract the ejector to its home position.
The pod elevator transports the pods proximate the press cylinder. It is comprised of a frame, an outer carriage movable within the frame, an upper pod movable within the outer carriage, an inner carriage movable within the outer carriage, and a lower pod movable within the inner carriage. The frame is constructed of frame members, mounting frame members, back frame members, stabilizers, cross-members, and legs. The frame is built in two sections, which are a frame top portion and a frame bottom portion. The top portion is cantilevered over the bottom portion. The outer carriage is a combination of a frame with left and right side channels and top and bottom angle brackets, a guide rail affixed to the inside of the left channel, a guide rail affixed to the inside of the right channel, two guide roller assemblies mounted on the top angle bracket positioned to the left and right of the side channels, two guide roller assemblies mounted on the bottom angle bracket positioned to the left and right of the side channels, a cable cylinder mounted to the top and the bottom angle brackets and a cable attached to a top angle bracket of the inner carriage by a cable travel stop, a rotatable shaft in opposing end bearings, the bearings affixed to the left and the right side channels, a pivot affixed at one end in a pre-determined angular position to the shaft and rotatably connected at the other end to a cylinder and the top end of the cylinder rotatably connected to the bottom of the top angle bracket. The inner carriage includes a frame with left and right side channels and top and bottom angle brackets, four guide roller assemblies mounted on the top and the bottom angle brackets positioned outside of the left and right side channels, a shaft in end bearings, a pivot affixed between the shaft and a cylinder rod and the cylinder pivotally affixed to the top angle bracket. The pod elevator can have a number of pods within it, but the embodiment shown in this specification has two pods. Support brackets are on top of the upper pod and support brackets are on the bottom of the lower pod. The outer carriage has a rotatable shaft in opposing end bearings, the bearings affixed to left and right side channels and one end of a pivot affixed to the shaft in a pre-determined angular position, the other end of the shaft rotatably affixed to a cylinder, and the top end of the cylinder rotatably affixed to the top angle bracket.
An upper pod is rotatably affixed on the shaft by insertion of the shaft though apertures in the upper support brackets. The outer carriage cylinder is actuated to extend the rod downward to clockwise rotate the shaft and the upper pod 90° upward.
The inner carriage is comprised of a rotatable shaft in opposing end bearings, the bearings affixed to the left and right side channels and one end of a pivot affixed to the shaft in a pre-determined angular position, the other end of the shaft rotatably affixed to a cylinder, and the top end of the cylinder rotatably affixed to the top angle bracket. The lower pod is rotatably affixed on the shaft by insertion of the shaft though apertures in the lower support brackets. The inner carriage cylinder is actuated to extend the rod downward to clockwise rotate the shaft and the lower pod 90° upward.
The elevator has the following modes of operation: load plate mode, separate pod mode, rotate pod mode, lower pod mode, eject plate mode, and return home mode.
In the load plate mode, the upper pod is positioned horizontally on the upper shaft in the outer carriage, the lower pod is positioned horizontally on the lower shaft in the outer carriage, the bottom of the upper pod abuts the top of the lower pod, whereby the indexer can load the upper and lower pods as if they were a single pod.
In the separate pod mode, the horizontal upper pod remains stationary and the horizontal lower pod separate from the upper pod by movement of the inner carriage downward to the bottom of the outer carriage at least a distance from the outside of the channel shaped retainer to the outside of the enclosure.
In the rotate pod mode the upper and lower pods are rotated upward from their horizontal positions to vertical positions.
In the lower pod mode the outer carriage moves along with the vertical upper pod, towards the bottom of the elevator, the inner carriage, located at the bottom of the outer carriage, moves along with the vertical lower pod to the bottom of the elevator, wherein the upper pod remains in it vertical position about the vertically positioned lower pod.
In the eject plate mode designated plates are ejected from compartments in the upper and lower pods.
In the return home mode the elevator is directed to return to its home position for loading. The inner carriage cylinder is actuated to extend the rod downward to clockwise rotate the shaft and the lower pod 90°.
DESCRIPTION OF DRAWINGS
FIG. 1 is a diagrammatic view of an embodiment of a production line configuration of the system, which includes an indexer and pod;
FIG. 2 is a perspective view of an embodiment of the indexer with its plate elevator in an up position;
FIG. 3 is a perspective view of an embodiment of the indexer with its plate elevator in a down position;
FIG. 4 is another perspective view of an embodiment of indexer with its plate elevator in an up position;
FIG. 5 is an exploded view of a portion of the embodiment of indexer illustrated in FIG. 4 ;
FIG. 6A is a perspective view of a conveyor module of an embodiment of the indexer of FIG. 1 ;
FIG. 6B is an exploded view of the conveyor module of an embodiment of indexer of FIG. 1 ;
FIG. 7A is a perspective view of plate assist assembly of an embodiment of the indexer;
FIG. 7B is an exploded view of a plate assist assembly employed in an embodiment of the indexer;
FIG. 8 is a perspective view of finger pusher assemblies used in an embodiment of the indexer;
FIG. 9 is a perspective view of an embodiment of an upper pod, fully loaded with plates;
FIG. 10 is a perspective view of an embodiment of a lower pod, fully loaded with plates;
FIG. 11 is a perspective view of an embodiment of the upper pod with one partially loaded plate;
FIG. 12 is a perspective view of an embodiment of the lower pod with one partially loaded plate;
FIG. 13 is a perspective view of an embodiment of the upper pod shown without any plates loaded;
FIG. 14 is an exploded view of an embodiment of the upper pod;
FIG. 15 is a perspective view of an embodiment of the lower pod without any plates loaded;
FIG. 16 is an exploded view of an embodiment of the lower pod;
FIG. 17 is an exploded view of an embodiment of the upper pod partition and ejector;
FIG. 18 is an exploded view of an embodiment of the lower pod partition and ejector;
FIG. 19 is a perspective view of an embodiment of the pod elevator in the load plate mode;
FIG. 20 is a perspective view of an embodiment of the pod elevator in the pod separation mode;
FIG. 21 is a perspective view of an embodiment of the pod elevator in the rotate pod mode;
FIG. 22 is a perspective view of an embodiment of the pod elevator in the lowering pod mode;
FIG. 23 is a perspective view of an embodiment of the pod elevator in the ejecting plate mode;
FIG. 24 is a perspective view of an embodiment of an outer carriage of the pod elevator with the inner carriage in the up position;
FIG. 25 is a perspective view of an embodiment of an outer carriage of the pod elevator with the inner carriage in the down position;
FIG. 26 is an exploded view of an embodiment of the outer carriage of the pod elevator with the inner carriage in the up position;
FIG. 27 is a perspective view of an embodiment of inner carriage of the pod elevator;
FIG. 28 is an exploded view of an embodiment of the inner carriage of the pod elevator; and
FIG. 29 is a perspective view of an embodiment of the inner carriage of the pod elevator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
System Level
The lithographic plate management system of the present invention is comprised of modules arranged in differing configurations to form myriad work flow arrangements. The main working modules are the imager 18 , image processor 9 , punch/bender 19 , indexer 2 , pod 3 , and pod elevator 4 ( FIG. 19 ). These modules are serviced by transport modules of various kinds. The system provides plate traffic control and tracking along the entire transport route. Some transport modules 8 , under control of a system PLC, transport plates forward or backward and right or left. They pause, hold, stop, start, slow down, speed up, rotate, index, sort, stack, elevate, or eject. The transport modules move press-ready plates to designated printing press locations.
Selected Modules
Plate indexer 2 receives the press-ready lithographic plates from belt transporter 8 or some other module in system 1 and loads each plate into a designated compartment of a pod 3 for delivery to the press. Pod 3 has several compartments that are separated from one another by parallel partitions, each of which is in a separate vertically spaced position. A pod elevator 4 moves the pods vertically from indexer 2 level to a second level on which the printing press is located.
A system controller (not shown) includes a programmable logic controller (PLC). It is the operating brain of system. It supervises the entire plate management and handling system. Among other things, it manages, monitors, and controls plate flow, system operation, alarms, and fault detection. It reports the need for preventative maintenance and does trouble-shooting.
Production Line Configurations
An embodiment of the lithographic plate management and handling system is illustrated in FIG. 1 , a plan view. The main elements of system include imaging module 18 , plate rotation module (not shown), multi-directional plate transfer module to change the direction of flow of the plate after leaving the imaging module 18 , processor 9 for developing the image, a plate stacker, and a plate punch/bender module 19 .
Indexer
Indexer module 2 is part of an integrated group of devices for transporting, loading, ejecting, and orienting lithographic plates. Indexer 2 pushes plates into a container (a pod 3 ) in succession by moving a plate elevator incrementally as the plates are loaded into the pod by the pusher, resulting in plates being stacked in individual positions one above another as best seen in FIG. 9 . The container or pod can be swiveled through an arc of 90 degrees.
After the printing plates pass through bender 19 (such as that described in U.S. Pat. No. 5,970,774) to form bends at the edges of the plate, they are placed sequentially on a multi-directional transporter, a dual lift up conveyor, or a belt transporter 8 and transported horizontally for delivery to indexer 2 . An embodiment of indexer 2 is shown in FIGS. 2-3 . Plate indexer 2 receives the press-ready lithographic plates, one at a time, from belt transporter 8 , which is configured in-line with indexer conveyor 154 ( FIG. 6A ). Indexer conveyor 154 is a loading module. It loads each of the plates in a pod 3 (or a cart pod 3 a ) designated by a PLC in the system for delivery to the press. The constructional features of pod 3 are shown in FIGS. 9-18 . As mentioned, pod has several compartments that are separated from one another by parallel partitions 219 , each of which is in separate vertically spaced positions.
As a plate begins to exit belt transporter 8 , it enters indexer conveyor 101 ( FIG. 2 ). A first sensor of indexer 2 , senses the entry of the leading edge of incoming plate and automatically initiates forward movement of the belts of indexer conveyor 101 . Indexer conveyor 101 operates at the same speed as does belt transporter conveyor 8 . Indexer conveyor 101 moves the plate to a position proximate a second sensor, which stops further plate movement. At the point when the plate is stopped, the plate is fully loaded into indexer conveyor 101 . Elevator motor 102 , operating under control of the PLC system controller, moves the indexer conveyor 101 vertically so that it (with encoded information on the plate, such as a bar code) is in horizontal alignment with the bar coded plate's assigned pod compartment. A look-up table in the memory of the system controller PLC is pre-programmed with an index of all of the compartments of pod 3 . The system controller associates each of the imprinted bar codes with a single one of the indexed compartments of each pod 3 . Typically, each of the printing plates moving within the system is imprinted with a bar code during, for example, the plate's initial entry into the system. Each indexed compartment is at a pre-determined vertical position of indexer 2 and that position is stored in system controller. In one embodiment, there may be 16 compartments. Therefore, for example, if a plate with bar code AAA is loaded into indexer conveyor 101 , the system controller PLC will sense the AAA bar code, associate it with the plate assigned to a particular compartment (9 th compartment, for example), and signal elevator motor 102 to move the index conveyor up or down, as the case may be, to the 9 th compartment. The now vertically moving index conveyor acts as an elevator and will sense when it has reached the vertical location of the 9 th compartment by reference to the indexer's linear encoder, which senses conveyor/elevator's position, and will stop moving at the 9 th compartment. At this juncture, plate pusher finger assemblies 106 (for example, 2 opposing assemblies proximate each side of plate) orient the plate so it's alignment on the plate conveyor elevator is in alignment with its assigned pod compartment. The plate is then ready for interference free movement into the assigned pod compartment. At the pre-determined vertical position, the system controller PLC signals the conveyor feature of the indexer conveyor/elevator 101 to begin forward movement of plate into its assigned compartment. When the trailing edge of the plate is sensed by the second sensor, the system controller signals the plate assist assembly 151 ( FIG. 7A ) to push the trailing edge of the plate fully into its compartment. After insertion of the bar coded plate into pod 3 , the system controller signals indexer conveyor/elevator motor 102 to return to the position associated with the belt transporter 8 level for receipt of another plate from the belt transporter 8 . The indexer handles one plate at a time. After receipt of the plate, the indexer conveyor elevator again begins its stepwise vertical movement under control of motor 102 until it reaches the designated compartment for the next plate, at which point the conveyor/elevator stops. As described previously, the next plate is placed in its respective indexed compartment and so begins anew the next series of cycles until a pod is fully loaded.
Indexer 2 is configured so that the PLC system controller can pause the operation of indexer 2 and thereby stop movement of press-ready plates already in indexer 2 . The system controller can also pause the operation of any conveyor 8 and thereby stop movement of any plate enroute to indexer 2 . The system controller is programmed to direct indexer 2 and other modules in the system when, for example, other plates are on a trajectory to intersect press-ready plates already in indexer 2 or enroute on a conveyor 8 to indexer 2 . In a highly configured system, the system controller may need to frequently control traffic due to multipathing of plates to multiple presses and the intersection of the multi-paths. The system controller thus acts like a stop and go light; stopping movement on some pathways while allowing movement on an intersecting pathway for higher priority plates for collisions avoidance.
FIG. 2 is a perspective view of an embodiment of indexer 2 with its conveyor/elevator 100 in an up position. FIG. 3 is a perspective view of an embodiment of indexer 2 with its conveyor/elevator 100 in a down position. FIGS. 2-3 illustrate indexer 4 with its conveyor/elevator 100 in-line with side horizontal frame members 110 A. FIG. 4 is also a perspective view of an embodiment of indexer 2 with its conveyor/elevator 100 in an up position.
Indexer 2 is comprised of frame 114 , conveyor/elevator 100 , elevator drive system 102 B, indexer conveyor 101 , plate centering assembly 105 , and plate finger pusher assembly 106 ( FIG. 8 ).
An embodiment of frame 114 is a box frame, as shown in FIGS. 2-3 , with side horizontal frame members 110 A, end horizontal frame members 110 B, vertical frame members 111 , and leveling pads 112 . Leveling pads 112 are adjustable for leveling indexer 2 . Horizontal and vertical frame members 110 A, 110 B, and 111 must be of an adequate size and have adequate strength to steadily support conveyor/elevator 100 and the other parts of frame 114 with little flexing. Tubular or square steel tubing is acceptable for this purpose.
Housing 113 is secured to frame 114 . Housing 113 provides an internal frame for conveyor/elevator 100 , elevator drive motor 102 B, and worm gear box 103 . Housing 113 comprises horizontal frame members 114 , vertical frame members 111 , side plates 116 ( FIG. 4 ), and drive motor support 117 ( FIG. 2 ).
Elevator 100 is movable vertically within frame 114 and housing 113 . Elevator 100 is formed of lightweight side box beams 124 A and end box beams 124 B FIG. 3 ) with a plurality of spaced-apart parallel top cross members 127 extending laterally between parallel side box beams 124 A for lateral strength. Elevator 100 can be in a down position to receive a lithographic plate and then raised to an elevated position for exiting the plate from indexer 2 into a selected compartment of pod 3 or plate rack 10 for delivery to the press. Alternatively, elevator 100 can be in an elevated position to receive a lithographic plate and then lowered to a down and/or up position for exiting the plate from indexer 2 into pod 3 or plate rack 10 for delivery to the press.
The elevator drive system raises and lowers elevator 100 . As seen in FIG. 5 , it is comprised of drive motor 102 B, 4:1 helical adapter 147 , worm gear box 103 , drive shafts 120 A and 120 B, bearings 142 A and 142 B, side plates 116 A and 116 B, spacer plates 135 A and 135 B, taper lock adapters 143 A and 143 B, upper drive belt pulleys 118 A, lower drive belt pulleys 118 B, open drive belt 109 , open drive belt clamp plate 119 , open drive belt clamps 166 , side plate 160 , single split collar 141 , taper lock idler 149 , idler mount 134 , take-up bolt 136 , take-up mount 133 , top plate 121 , linear shafts 108 , linear shaft mounting block 137 , and linear bearings 107 .
Drive motor 102 B, an AC motor, is connected to 4:1 helical adapter 147 , which reduces the drive motor's speed to ¼ its output rpm. The output of 4:1 helical adapter 147 is delivered to worm gear box 103 and then to drive shafts 120 A and 120 B. Drive shafts 120 A and 120 B run in bearings 142 A and 142 B. Bearings 142 A and 142 B are mounted on the backside of side plates 116 A and 116 B. Spacer plates 135 A and 135 B offset side plates 116 A and 116 B inwardly from frame 114 for clearance from outside of frame 114 . Drive shafts 120 A and 120 B extend through an aperture in each side plate 116 A and 116 B and are engaged by taper lock adapters 143 A and 143 B, which are affixed inside lower drive belt pulleys 118 B. Open drive belt 109 engages upper and lower drive belt pulleys 118 A and 118 B. Upper drive belt pulleys 118 A include taper lock idlers 149 fixedly engaged within the hubs of upper drive belt pulley 118 A. Shaft 134 B of idler mount 134 A rotatably extends through apertures in taper lock idlers 149 and are held in place by single split collars 141 . Idler mounts 134 A are held in place by take-up mounts 133 , which are affixed to horizontal frame members 110 and to top plates 121 . Top plates 121 are also affixed to horizontal frame members 110 A. Take-up bolt 136 is adjustable to increase or decrease tension in open drive belts 109 and it extends through top plates 121 for easy access. The ends of open drive belt 109 attach to open drive belt clamp plate 119 and are clamped to open drive belt support 119 by open drive belt clamps 166 . Open drive belt clamp plate 119 is attached to elevator 100 . Motor drive shafts 120 A and 120 B protrude through side plates 116 A and 116 B and connect with their respective upper and lower drive belt pulleys 118 A and 118 B. Side plates 116 A and 116 B are attached to vertical housing members 115 at the bottom of the vertical housing members. Each linear shaft 108 is fixed at its ends within a mounting block 137 , so that it neither rotates or moves vertically. Linear bearings 107 are attached to elevator 100 . Each linear shaft 108 rides within two linear bearings 107 allowing elevator 100 to move smoothly in a vertical direction. Upper drive belt pulleys 118 A and 118 B are indirectly attached to upper horizontal housing members 114 . Elevator drive motor 102 is seated on drive motor support 117 and fastened to horizontal frame member 114 . Motor drive shafts 120 A and 120 B extend from each side of elevator gear drive box 103 and extend through side plates 116 A and 116 B and into lower drive belt pulleys 118 A and 118 B on each side of indexer 2 . Elevator drive motor 102 B is configured with 60:1 speed reducer 147 for transmission of power from its armature, which is contained in drive motor 102 B housing.
FIGS. 6A-6B best illustrate indexer conveyor 154 of conveyor/elevator 100 . A series of web pulleys 125 are affixed to drive shafts 126 . The ends of each drive shaft 126 are rotatably affixed into bearings 128 . Bearings 128 are affixed to side box beams 124 A parallel to top cross members 127 near end box beams 124 B. The two web pulley 125 /drive shaft 126 combinations are mounted near each end box beams 124 B and in parallel to each, so flat web belts 104 can be rollably affixed to in-line web pulleys 125 near each end box beam 124 B. Flat web belts 104 move around web pulleys 125 in parallel with side box beams 124 A and other web pulleys 125 . Web pulleys 125 move longitudinally by chain drive 130 connected to sprockets 131 on drive shafts 126 . Chain drive 130 is driven by an electric motor (not shown).
Plate centering assembly 155 ( FIG. 6B ) is mounted perpendicular to side box beams 124 A. It may be comprised of a pneumatic or electrical actuator assembly. The push rod of a pneumatic actuator moves the lithographic plate laterally after it enters onto conveyor/elevator 100 . In one embodiment, there are four plate centering assemblies 105 . The number of plate centering assemblies depends to some extent upon the size of the plate. Smaller plates may be centered by two or three such assemblies. Indexer 2 is programmed so that each of the plate centering assemblies 105 work in conjunction with one another to move the plate in a lateral registration position. After the plate has entered indexer 2 , plate finger pusher assembly 106 ( FIG. 4 ) adjusts the position of a plate on bed conveyor 132 of conveyor/elevator 100 to be in registration with the bed. The registration position on the bed is established so that when the plate begins to be ejected from indexer 2 it will travel in a pre-set direction within the ambit of a defined path that is in-line with the entry point of a designated compartment of pod 3 . If the plate is not in registration, it may jam within indexer 2 or with pod 3 as it is ejected from indexer 2 .
Plate finger pusher assemblies 106 A and B are best illustrated in FIG. 8 . FIG. 8 is a perspective view of assemblies 106 A, of which there are three, and is an exploded view of assembly 106 B, of which there is one. Assemblies 106 A and 106 B are identical to one another. Two assemblies 106 are mounted on each side of the lithographic plate and move the plate for proper positioning on the bed of indexer 2 . Assembly 106 is comprised of dual rod cylinder 171 , finger spring 168 A, finger spring block 168 B, cylinder bracket 169 , and flow control fitting 170 . Two finger pusher assemblies 106 are attached to each side box beam 124 of elevator 101 by cylinder bracket 169 , as shown in FIG. 4 . Dual rod cylinder 171 is operated pneumatically. Flow control fitting 170 has a port, the size of which is manually adjustable by a port handle to decrease or increase the amount of air entering the cylinder and thereby driving the movement of the cylinder. Too much air may over-drive the rod and damage the plate. Too little may not move the plate into position. Finger spring 168 A is a compliance spring. It is attached to block 168 B. It introduces some give or resiliency when it connects with the plate so the plate will not be damaged. V-portion 168 C is the contact point with the plate.
Plate assist assembly 151 is illustrated in FIGS. 7A-7B . When the trailing edge of a plate is sensed by second sensor 185 , the system controller not shown signals plate assist assembly 151 to push the trailing edge of the plate fully into its compartment 200 . Plate assist assembly 151 is mounted over the top of indexer conveyor/elevator 101 . Plate assist mounts 153 B are mounted between side box beams 124 A on elevator 100 . A rear plate assist mount 153 B is mounted proximate the plate exit point of indexer conveyor/elevator 101 and the front plate assist mount 153 B is mounted proximate the center of indexer conveyor/elevator 101 . Rodless cylinder mounts 172 are affixed on plate assist mounts 153 B at the center-line of each mount 153 B and rodless cylinder 179 is mounted to rodless cylinder mounts 172 . Rodless cylinder 179 is mounted in a direction parallel to movement of flat web belts 104 on indexer conveyor bed 154 . Base cylinder mount 174 is affixed to rodless cylinder 179 and slides forward from its position near centrally disposed front plate assist mount 153 B when the system controller signals it to push a plate into its respective compartment 200 . A pusher assembly is mounted to base mount cylinder 174 at its leading edge when pushing a plate. The pusher assembly is comprised of two pusher blocks 177 , respective cylinders 182 , respective cylinder mounts 175 . When base cylinder mount 174 moves a plate into compartment 200 , it passively pulls electrical conduit chain 180 with it. When base cylinder mount 174 completes its task of pushing a plate into compartment 200 , electrical conduit chain 180 deliveries the signal to rodless cylinder 179 to return to home at its start position in readiness for pushing the next plate. Electrical conduit chain 180 is supported by chain guide 176 . Electrical conduit chain 180 is connected at one end to the top of base cylinder mount 174 and at the other end to the bottom of chain guide 176 . Each end is connected to their respective locations by small brackets 181 .
Pod
As will be illustrated with respect to an embodiment of pod elevator 4 described infra, pod elevator 4 has two pods which are integral parts of pod elevator 4 .
Pod 3 of FIG. 1 is more particularly shown in FIGS. 9-18 and comprises a container that receives bar coded plates from indexer 2 (the pod loading machine) and loads the pod with the plates. The plates are loaded in a horizontal position. Pod 3 is then transported to a station in close proximity to a printing press. A press person extracts each plate from the pod, one by one, and locks-down each plate on the selected press cylinder. Pod 3 has several compartments 200 that are separated from one another by parallel partitions 201 (consisting primarily of rails 219 , see in FIG. 11 ), each of which are in separate vertically spaced positions. Indexer 2 loads the bar coded plates into the various compartments 200 of pod 3 , as designated by the system's PLC, in succession by moving indexer elevator 100 incrementally up or down until it is in horizontal alignment with the bar coded plate's assigned pod compartment 200 , resulting in plates being stacked in individual compartments 200 , one above another. In one embodiment of pod 3 , there are 16 compartments 200 .
Pod 3 can be integrated with a pod elevator 4 shown in FIGS. 19-23 for movement of the plates stored in pod 3 to the press. Pod 3 is in a horizontal position in pod elevator 4 after it is loaded with plates. The pod can then be swiveled through an arc of 90° to bring it into a vertical position within the pod elevator 4 for vertical movement by the pod elevator 4 . The plates ride within pod 3 in an upright-vertical position, suspended by a bend along one edge of the plate, the bend having been made by punch/bender 19 . Vertically hung pod 3 is transported (lowered or raised, as the case may be) by pod elevator 4 to a station where the plates contained therein will be manually removed and loaded onto a designated press cylinder by a press operator, according to each plate's bar coded information.
Each parallel compartment 200 of pod 3 is provided with a plate hanger 202 . Plate hangar 202 is designed to enable the relatively fragile plates to be rotated 90° from their horizontal positions to vertical positions without damage to the plates and image thereon. After rotation, the plates are automatically suspended on hangers 202 (FIG. 17 ) in vertical positions. Hangers may be made of a plastic material for avoidance of plate scratching. Hanger 202 is affixed longitudinally to enclosure base 223 . Hanger 202 is comprised of a top bracket 202 A connected to an angled bracket 202 B. Top bracket 202 A is in-parallel with the bottom surface of the plate and the bottom surface of the plate rests on top bracket 202 A. Projecting downward from top bracket 202 A and from the bottom surface of the plate is angled bracket 202 B. Angled bracket 202 B projects downward at an angle that is over 90° from top bracket 202 A to form an anvil shaped hanger assembly 202 . The bend formed along one edge of the plate is tucked around the point where the top bracket 202 A and the angled bracket 202 B meet, thereby hooking the anvil shaped bend on the edge of the plate over hanger 202 .
FIG. 9 is a perspective view of an embodiment of upper pod 3 , fully loaded with plates. FIG. 10 is a perspective view of an embodiment of lower pod 3 , fully loaded with plates. FIG. 11 is a perspective view of an embodiment of upper pod 3 with one partially loaded plate. FIG. 12 is a perspective view of an embodiment of lower pod 3 with one partially loaded plate extending outward from a front end portion of the pod. Enclosure 217 ( FIG. 9 ) is comprised of base 233 , cover 214 , and two end caps 205 . Opposite enclosure 217 is channel shaped retainer 208 ( FIG. 10 ). Enclosure and channel shaped retainer are tied together by a support member 226 affixed from a first end of enclosure 217 to a first end of channel shaped retainer 208 . Another support member 226 is affixed in the same manner between the second end of enclosure 217 and the second end of channel shaped retainer 208 . Two L-shaped supports 206 extend, in parallel, across the top of pod 3 and provide rigid transverse bracing between enclosure 217 and channel shaped retainer 208 . L-shaped supports 206 are respectively affixed at their ends to enclosure cover 214 and to the top of channel shaped retainer 208 A and to the face of channel shaped retainer 208 B. A plurality of curvilinear rails 219 are connected between support members 226 at both ends of pod 3 . Curvilinear rails 219 support the lithographic plates and form the partitions 201 between the compartments 200 of the pod. Each compartment 200 comprises a separate envelope for a separate plate.
Facing mounting blocks 207 are affixed to those portions of L-shaped supports 206 that are in contact with channel shaped retainer 208 . Mounting blocks 207 provide rigidity to that portion of the L-shaped supports 206 . Mounting blocks 207 also include keyless hubs 209 with apertures for insertion of pivot shaft 310 between opposing keyless hubs 209 . As will later be explained, pivot shaft 310 is used by a pod elevator 4 to vertically move pod 3 .
Two dual rod cylinders 212 ( FIG. 9 ) are mounted in enclosure 217 . Both cylinders 212 act to gently push the plate towards channel shaped retainer 208 and bring the apex of the anvil shaped bend of the plate in mating contact with the apex of anvil shaped hanger 202 A. The effect is that the plate is held firmly in place in pod 3 during movement of the pod and damage to the plate is virtually eliminated.
FIG. 13 is a perspective view of an embodiment of upper pod 3 without any plates loaded. FIG. 14 is an exploded view of an embodiment of upper pod 3 . FIG. 15 is a perspective view of an embodiment of lower pod 3 without any plates loaded. FIG. 16 is an exploded view of an embodiment of lower pod 3 .
FIG. 17 is an exploded view of an embodiment of the partition and ejector of upper pod 3 . FIG. 18 is an exploded view of an embodiment of the partition and ejector of lower pod 3 . Partition 201 is comprised of six curvi-linear rails 219 . The rails 219 are connected to transverse rail supports 226 at the first and second ends of pod 3 with snap lock clips 227 . Snap lock clips 227 are fastened to rail supports 226 and the ends of rails 219 are snapped into the top of snap lock clips 227 . As shown in the figures, pinch lock clips 230 hold rails 219 together in pairs at the point where rails 219 abut one another. Support shaft 233 extends transversely across rails 219 . Pinch lock clips 230 are spaced on shaft 233 so each clip 230 locks onto a single rail 219 where rails 219 abut one another. The spacing is shown in FIGS. 17-18 . Spacing is maintained by round spacers 229 lying in between the spacers on support shaft 233 . As shown in the figures, there are three such support shafts 233 supporting each of the partitions. However, there can be more or fewer shafts depending upon the length of the rails/partitions. A T-clamp 228 is attached to hanger 202 at the end of support shaft 233 and tied into channel shaped retainer 208 ( FIG. 14 ). The top of hanger 202 is in the same plane as the top of rails 219 .
A plate ejector 215 ( FIG. 17 ) is comprised of a single rod cylinder 225 and mounting bracket 232 . The cylinder is mounted on mounting bracket 232 and the bracket is affixed to support member 226 on the second end of each pod compartment 200 . Ejection cylinder 215 extends in a direction from the second end of each pod compartment 200 to the first end of each pod compartment 200 . As the ejection cylinder 215 is extended it ejects the plate from its compartment towards the second end of pod 3 , one at a time, into the hands of a printer who will place the plate on the press cylinder. Plate ejector cylinder 215 retracts its piston 225 upon reaching its maximum travel point. To eject the plates, the printer signals the system controller to open a pod door. When the pod door opens, plate ejector 215 associated with a designated compartment 200 dispenses the plate from that compartment into the hands of the printer.
Pod elevator 4 can be scaled up or down to move more or less than two pods 3 . The basic configuration of pod elevator 4 is the same regardless of pod capacity, except that the size of elevator 4 is scaled up or down (in for example, its height, pod capacity, or the size of the lithographic plate) to meet the needs of a customer's pre-press configuration.
Cart Pod
The cart pod (not shown) serves a similar function as does the previously described pod, albeit in a less automated manner. Primarily the cart pod is less automated because it cannot interface with the pod elevator and it is generally a wheeled device. It does however fully interface with the indexer and is loaded by the indexer in the same manner the indexer loads the pod. Once it is loaded with plates it is transported proximate the press cylinder, where the plates are unloaded and locked-up on a press cylinder. The cart pod is configured to be loaded with plates one at a time by the indexer. The configuration includes dimensional attributes that allows the cart pod to be in alignment with the pusher end of the indexer as if it were a pod. In this manner the pusher end of the indexer is in-line compatible with the cart pod. Moreover, the cart pod is configured to accept the same size plates as does the pod. The pusher assembly of the indexer pushes the plate into the cart pod in the same manner as it does with the pod. The cart pod also has separate vertically spaced compartments as does the pod. The indexer pushes plates into the separate cart pod compartments in succession by lowering the plates relative to the compartments incrementally as the plates are loaded by the pusher assembly, whereby the plates become stacked in individual positions one above another. Parallel partitions separate the cart pod into pod compartments. The elevator moves a plate in a vertical direction into horizontal alignment with the cart pod compartment that corresponds to a code on the plate. The compartments are indexed at a pre-determined vertical position of the indexer. A linear encoder senses the point at which the elevator has reached a specified vertical location corresponding to the assigned cart pod compartment, at which point the elevator stops. Pusher finger assemblies proximate each side of the plate align the plate with the elevator and the assigned cart pod compartment. Upon completion of alignment of the plate with the elevator and assigned cart pod compartment the indexer conveyor initiates forward movement of the plate into the assigned cart pod compartment and upon sensing the trailing edge of the plate by the second indexer sensor means, a plate assist assembly pushes the trailing edge fully into the assigned cart pod compartment.
Pod Elevator
The structure of pod elevator 4 is described, followed by the description of its operation.
FIG. 19 best illustrates the frame of pod elevator 4 . The frame is comprised of multiple frame members 300 , 300 A, 300 B and 300 C. These frame members form the skeleton of pod elevator 4 . Pod elevator 4 is most often mounted to a wall by mounting pads 304 . To assure stability, pod elevator 4 is also floor-mounted by, for example, bolting the elevator into the floor through mounting frame members 300 A. The top and bottom portions of elevator 4 are bolted together through top assembly pad 305 A, located at the end of back frame member 300 B of the top portion, and through a bottom assembly pad, located at the end of back frame member 300 B of the bottom portion. The bottom portion of elevator 4 also has two front, upward extending legs 300 C, each with an assembly pad which are bolted together. The top portion of elevator 4 is cantilevered over the bottom portion. The bottom portion of elevator 4 is sized to fit through an opening provided in a first floor ceiling of a two-story building. The cantilevered top portion is above the ceiling and bolted to the bottom portion of elevator 4 . The top portion has a larger footprint than that of the bottom portion. Diagonal stabilizers 303 strengthen elevator frame members 300 and act as sway bracing, among other things.
The operating parts of pod elevator are outer carriage 301 and inner carriage 302 . FIGS. 24-26 illustrate the structure of outer carriage 301 and to some degree, inner carriage 302 . FIG. 24 illustrates inner carriage 302 in an up-position relative to outer carriage 301 . FIG. 25 illustrates inner carriage 302 in a down-position relative to outer carriage 301 . FIG. 26 is an exploded view of the structure of outer carriage 301 and to some degree, inner carriage 302 . FIGS. 27-29 illustrate inner carriage 302 .
The exploded view of FIG. 26 best illustrates the structure of outer carriage 301 . The frame of outer carriage 301 includes bottom angle bracket 318 , left and right side channels 317 , and top angle bracket 315 . Each frame member is securely bolted or welded together. Left and right guide rails 319 are affixed to the insides of left and right side channels 317 and run more or less the full length of left and right side channels 317 . Four guide roller assemblies 316 lie outboard of side channels 317 ; a pair mounted on the top of bottom angle bracket 318 and a pair on the bottom of top angle bracket 315 . Shock absorbers 329 are mounted on shock mounts 320 at the top and the bottom of guide rails 319 . They project upward from the bottom of the guide rails 319 and downward from the top of guide rails 319 to absorb whatever light shock may occur when inner carriage 302 bottoms out at the end of its downward travel along guide rails 319 and when it tops out at the end of its upward travel along guide rails 319 . Cable cylinder 306 A is attached to bottom angle bracket 318 by intermediate mount 307 . Mount 307 offsets cylinder 306 A from bracket 318 to allow clearance between inner carriage 302 and the cable cylinder. Likewise, cylinder plate mounts 312 perform the same function at the top of cable cylinder 306 A. Cable 313 A is attached to the top angle bracket of inner carriage 302 by cable travel stop 313 B so that cable cylinder motor 306 B is able to move inner carriage 302 up and down within outer carriage 301 as and when signaled to do so by the system PLC (not shown).
FIGS. 27-29 illustrate inner carriage 302 . Inner carriage 302 is similar in certain respects to outer carriage 301 . Inner carriage 302 is comprised of left and right side channels 333 A and 333 B. Each channel has mounting bracket at its top and bottom for mounting channels 333 A and 333 B to top angle bracket 331 and to bottom angle bracket 332 . Guide roller assemblies 336 B are affixed to the top surface of bottom angle bracket 332 and to the bottom surface of top angle bracket 331 . With reference to FIG. 28 , guide roller assemblies 336 A include rollers 336 B and mounting brackets 336 C on which rollers 336 B are rotatably affixed. Shaft 334 A has bearing 335 A at each end. Each bearing has a mounting flange 335 C. Mounting flanges 335 C are attached to bearing mounts 335 B, which in turn are affixed to side channels 333 A. Pivot 334 B is affixed to shaft 334 A between bearings 335 A. Pivot arm 334 B is connected to the cylinder rod of cylinder 330 A by a cylinder attachment assembly. This assembly includes, for example, a threaded bolt u an aperture 337 C in a cylinder rod end, a spacer 337 D, and an aperture 337 E in pivot arm 334 B. Cylinder 330 A is attached to a clevis mounting plate inserted by pin 338 B through eyes 338 B of cylinder 330 A and through eye 338 D of clevis mounting plate 338 A. Mounting plate 338 A is mounted to the bottom of top angle bracket 331 .
FIGS. 19-23 illustrate pod elevator 4 with two pods 3 mounted therein. Pods 3 are initially stacked horizontally in elevator 4 , prior to putting the elevator in service. The pods are an integral part of elevator 4 . They are not intended to be removed in the normal course of the printing operation. However, the pods can be removed with little difficulty and used to store the lithographic plates for use at a later time.
As previously mentioned and as shown in FIG. 19 , an embodiment of elevator 4 has two pods 3 . The upper pod is held by outer carriage 301 of FIG. 24 . The lower pod is held by inner carriage 302 . L-shaped supports 206 can be seen on the top of the upper pod. FIG. 26 shows shaft 310 A. The shaft extends through keyless hubs 209 in each L-shaped support of the upper pod. Shaft 310 A is rotatably held in bearings 326 , which are affixed to left and right side channels 317 of elevator 4 ( FIGS. 24-26 ). Shaft 310 A inserts into an aperture in one end of pivot 310 B of the upper pod and is non-rotatably affixed in the angular position shown in FIGS. 24 and 26 . Cylinder rod 325 B of cylinder 325 A is rotatably connected to pivot arm 310 B at the other end of pivot 310 B. The top end of cylinder 310 A is pivotally connected to the bottom of top angle bracket 315 . When cylinder 310 A is actuated by the system controller, rod 325 B moves downward, rotates shaft 310 A clockwise 90°, and likewise rotates upper pod 3 clockwise 90°. Shaft 310 A rotates pod 3 clockwise 90° due to the fact that shaft 310 A is gripped by the two keyless hubs 209 on pod 3 . The clockwise rotation of pod 3 around shaft 310 A forces enclosure 217 of the upper pod to also rotate 90° with the result that the formerly horizontal upper pod is now vertical with enclosure 217 above channel shaped retainer 208 , as can be seen in FIG. 21 . Rotation of the lower pod occurs in the same manner as for the upper pod. The difference is that lower pod 3 is pivoted around shaft 334 A of inner carriage 302 rather than shaft 310 A of outer carriage 301 . Lower pod is also oriented differently than upper pod, in that L-shaped supports 206 are on the bottom of lower pod 3 . L-shaped supports 206 mounted in this manner so that the two pods are abutting one another in the load plate mode. When abutting, the spacing of the partitions of pod 3 are close enough together so that the upper and lower pods appear to indexer 2 to be a single larger pod. This allows for more efficient loading of the two pods by indexer 2 .
The operation of elevator 4 includes six sequential modes.
The first mode shown in FIG. 19 is the “load plate” mode. In the load plate mode, indexer 2 loads bar coded plates into an identified compartment 200 of an identified pod 3 , of which there are two. Prior to loading the plates, a bar code reader on indexer 2 reads the bar code of the plate to be loaded. Identifiers for pod 3 and for the compartment 200 (in which the plate will be loaded) in identified pod 3 are sensed by magneto-resistive transducer 144 mounted on indexer 2 . Transducer 144 senses each indexed position of the indexer's elevator 100 as it moves upwardly or downwardly within indexer housing 113 . Each indexed position corresponds to the position of a specific compartment 200 in a specific pod 3 . The identifier for the compartment, the identifier for the pod, and the bar coded information on the plate is fed back to the system PLC of the plate management and handling system and are stored in the PLC's memory. As shown in FIG. 19 , upper pod 3 is hung on outer carriage 301 by shaft 310 A and is affixed to shaft 310 A by keyless hubs 209 of upper pod 3 . Lower pod 3 is hung on inner carriage 302 by shaft 334 A and is affixed to shaft 334 A by keyless hubs 209 of lower pod 3 .
The second mode shown in FIG. 20 is the “separate pod” mode. In this mode, adjacent upper and lower pods 3 of FIG. 19 are vertically separated. During separation, upper pod 3 remains stationary in the load plate position. Upper pod 3 is connected to outer carriage 301 , which consequently also remains stationary. Lower pod 3 is connected to inner carriage 302 . Inner carriage 302 rides within outer carriage 301 . Separation of lower pod 3 from upper pod 3 occurs when inner carriage 302 moves downward within outer carriage 301 . Inner carriage 302 moves downward when it receives a signal do so from the system PLC. Upon receiving the signal, inner carriage 302 is moved down to the bottom of outer carriage 301 by inner carriage cable 313 A and its associated parts, comprising four inner carriage cable roller assemblies 336 A, inner carriage cable attachment point 313 B, inner carriage cable cylinder 306 A, and inner carriage cable motor 306 B. Inner carriage 302 rides up and down on inner carriage rails 319 A and B. Rails 319 A and B are captured by the three guide rollers 336 B of guide roller assembly 336 A. The lower pod is separated from the upper pod by at least a distance equal to the width of pod 3 . The width of pod 3 is defined by the distance from the outside of channel shaped retainer 208 to the outside of enclosure 217 . During and initially after pod separation, the pods remain in a horizontal position.
The third mode shown in FIG. 23 is the “rotate pod” mode. In this mode, as previously described, each pod is rotated upwards 90° from its horizontal orientation to a vertical orientation.
The fourth mode shown in FIG. 24 is the “lower pod” mode. In this mode, both of the vertically hung pods of FIG. 23 are moved downwards to the bottom of elevator 4 . Downward movement of both of the pods occurs simultaneously by downward movement of outer carriage 301 . Outer carriage 301 contains inner carriage 302 and its associated pod. Inner carriage 302 was moved in the lowest position within outer carriage 301 during the “separate pod” mode. Outer carriage 301 moves downward when it receives a signal from system controller to do so. Upon receiving the signal, outer carriage 301 is moved down to the bottom of pod elevator 4 by outer carriage cable 308 B and its associated parts, comprising four outer carriage cable roller assemblies 316 , outer carriage cable attachment point (not shown), outer carriage cable cylinder 308 A, and outer carriage cable motor 308 D. Outer carriage 301 rides up and down on outer carriage rails 319 . Rails 319 are captured by guide roller assemblies 316 , which are each comprised of 3-rollers.
The fifth mode shown in FIG. 25 is the “eject plate” mode. After the pod elevator's delivery of the plate to a press area, the system controller sends the plate's bar coded information and identifiers for compartment 200 and pod 3 (sometimes referred to as the plate address) to the press-person. The information is most conveniently provided on an electronic display. Among other information, the information tells the press-person on which cylinder the ejected plate is to be placed. In this mode, the press-person signals the system controller to eject the identified plate out of its pod compartment 200 into the hands of the press operator. The press operator then locks the plate on the cylinder designated by the information sent to the display by the system controller.
The sixth mode is the “return home mode.” In this mode, the system controller directs pod elevator to return to its home position for further loading of the pods by indexer 2 . The sixth mode reverses the sequence of the previously described five modes.
Although the apparatus for loading lithographic plates into a container for transport to a press cylinder and the process thereof have been described with reference to the embodiments, those skilled in the art will recognize that numerous changes may be made in form and detail without departing from the spirit and scope of the apparatus and process.
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Transportation of a lithographic plate uses an indexer to load plates into pods for delivery to a press cylinder via a pod elevator or a pod cart. The plates are imprinted with a bar code, imaged, punched, bent, sheared, corner notched, and registered to a press cylinder. The plates are loaded into the indexer, which moves the loaded plates into a position in alignment with designated pod compartments, and loads the plates into each of the designated pod compartments by indexed movement of an elevator within the indexer. The pod elevator or the pod cart moves the pods proximate to a press cylinder where the plates are unloaded from the pod and loaded onto a press cylinder. A computing device, such as a PLC, directs the process. A vision system senses information from the indexer, pod, pod elevator, and the plate for feedback to a PLC, which initiates all of the foregoing operations.
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RELATED APPLICATION
This application claims priority to U.S. Provisional Application No. 60/324,825 filed Sep. 25, 2001. The content of the application is herein incorporated by reference in their entirety.
PRIORITY DOCUMENTS
This application is a 371 application of PCT/US02/30197, filed Sep. 24, 2002, which claims priority to U.S. Provisional application 60/324,835, filed Sep. 25, 2001.
FIELD OF THE INVENTION
This invention relates to the field of reagents and diagnostics for the preparation of pathogen antigen, DNA, and RNA for pathogen detection and quantification by the formation and establishment of stable chronically expressing pathogen containing cell lines.
BACKGROUND OF THE INVENTION
Most, if not all pathogens, destroy their host cell during pathogen replication. Death of living cells can follow more than one possible scenario. It may result from an external injury, from cell killing during acute infection with cytopathic pathogens, or it may be the outcome of activating an internal pathway for cell suicide—programmed cell death. Programmed cell death or apoptosis is a controlled process by which unwanted cells are selectively eliminated. Apoptosis is a normal physiological process of eliminating unwanted cells from living organisms during embryonic and adult development, but can also be induced in cells following exposure to a pathogen.
The mechanism by which pathogens cause cell death—either direct killing or indirect—varies with the pathogen and the host cell in question. Controversy surrounds the cause of pathogen-induced cell death in even in the most extensively studied pathogens. For example, in human immunodeficiency virus type 1 (HIV-1)-initiated killing of CD4+ cells T cell death has been reported to be caused by syncytium formation-interaction of the envelope glycoprotein (gp120) with CD4 and subsequent fusion of the cells; influenced by type 1/type 2 cytokine modulation; mediated by specific cell death proteases (caspases) that function in the distal portions of the proteolytic cascades involved in apoptosis; membrane tumor necrosis factor induced cooperative signaling of tumor necrosis factor membrane receptors p55 and p75; Fas-induced apoptosis; and direct interaction of HIV gp120 envelop with the T cell CD4 molecule. Although agreement in the mechanism of cell death is disputed, it is clear that pathogen replication results in host cell destruction.
Pathogens replication can only occur inside host cells, commandeering the cell's machinery to reproduce. Infection typically begins when a pathogen encounters a cell with a specific cellular surface receptor molecule that matches the proteins found on the virus. The membranes of the virus and the cell will fuse, followed by release of viral nucleic acids, proteins and enzymes into the cell. Cell-to-cell spread of the pathogen also can occur through the fusion of an infected cell with an uninfected cell. The pathogen nucleic acid moves to the cell nucleus, where in most cases is spliced into the host DNA (for RNA-based pathogens, pathogen encoded reverse transcriptase converts RNA into DNA). Once incorporated into the cellular genome, RNA copies are made that are read by the host cell protein-malcing machinery. After the MRNA is processed in the cell nucleus, it is transported to the cytoplasm. The pathogen co-opts the cellular protein-making machinery to make long chains of viral proteins and enzymes, using the pathogen MRNA as a template. Newly made pathogen proteins, enzymes and nucleic acids gather inside the cell, while the pathogen envelope proteins aggregate within cellular membranes. An immature viral particle forms and pinches off from cellular membranes, acquiring an envelope. Depending on the pathogen, the mature virus particle is either released into the cytoplasm of the cell or released external to the cell.
In the case of HIV-1, the outer coat of the virus, known as the viral envelope, is composed of 72 copies (on average) of a complex HIV protein that protrudes from the envelope surface. This protein, known as Env, consists of a cap made of three or four molecules called glycoprotein (gp) 120, and a stem consisting of three or four gp41 molecules that anchor the structure in the viral envelope. Within the envelope of a mature HIV particle is a bullet-shaped core or capsid, made of 2,000 copies of another viral protein, p24. The capsid surrounds two single strands of HIV RNA, each of which has a copy of the virus genes—nine genes in total. Three of these, gag, pol and env, contain information needed to make structural proteins for new virus particles. The env gene, for example, codes for a protein called gp160 that is broken down by a viral enzyme to form gpl20 and gp41, the components of Env. Three regulatory genes, tat, rev and nef, and three auxiliary genes, vif, vpr and vpu, contain information necessary for the production of proteins that control the ability of HIV to infect a cell, produce new copies of virus, or cause disease. The core of HIV also includes a protein called p7, the HIV nucleocapsid protein; and three enzymes that carry out later steps in the virus life cycle: reverse transcriptase, integrase and protease. Another HIV protein called p17, or the HIV matrix protein, lies between the viral core and the viral envelope.
The ability to either molecularly clone and subsequently express a gene by recombinant technology, isolate whole pathogens, or purify specific pathogen gene(s), has led to the development of sensitive assay systems for detecting pathogens and for measuring immune responses to their infection. Because early pathogen infection often causes no symptoms, a doctor or other health care worker relies on testing a person's blood for the presence of antibodies (disease-fighting proteins) to the pathogen in question for diagnosis. By early testing, treatment at a time when the individuals' immune systems are most able to combat the pathogen and thus prevent the spread the virus to others could occur. Medical diagnose of pathogen's infection is normally performed by using two different types of antibody tests, ELISA and Western Blot. Diagnostic studies with a number of pathogens show that pathogen burden predicts disease progression. That is, people with high levels of pathogen in their bloodstream are more likely to develop pathogen-related symptoms or to die than individuals with lower levels of pathogen. Methods are available to detect specific antigens or nucleic acid sequences. These techniques can detect pathogen exposures that occur before antibody responses are established. Diagnostic detection for most pathogens exist in first-, second-, and third-line screening procedures and the use of Western Blot analysis is routinely established as a recognized confirmatory method.
SUMMARY OF THE INVENTION
This invention provides for the formation and establishment of stable chronically expressing pathogen cell lines for the preparation of pathogen antigens and nucleic acids. The established cell lines continually express the pathogen and contain the pathogens DNA stably integrated into the host cells DNA without detrimental effects on cellular viability. Once the line is established, reproducible preparations of pathogen antigens and nucleic acids can be prepared for reagent and diagnostic purposes. The invention is intended for in vitro use for the purpose of pathogen detection and quantification, although purification of native antigens and/or amplification of specific pathogen nucleic acid sequences, therapeutic vaccines, and monitoring or elucidating immune responses in vitro or in vivo can also be envisioned.
Establishing continually expressing pathogen antigen(s) cell lines has several advantages over procedures utilizing direct infection of host cell lines for obtaining enriched preparations of pathogen antigens and nucleic acids. Established lines allow reproducibility between preparations by controlling the rate, amount, and level of pathogen antigen transcription and translation. By fixing the number of pathogen genome integration sites in an established cell line (a process that is essentially uncontrollable when cells are directly infected) the level of antigen expression is controlled and synchronize. Synchrony can be achieved by enhancing expression coordinately by treatment with know inducers that up-regulate transcriptional and/or translational/post-translational events. However, even without induction, continuous expression and assemble of virus particles released from cells that cumulate in the culture media during expansion can significantly increase pathogen antigen yields. The chronic expressing pathogen containing cell lines can be established by standard infection procedures, transfection of pathogen containing nucleic acid sequences, transduction of pathogen containing nucleic acid sequences, or by genetically engineering the pathogen antigen of interest by recombinant techniques and assembling the pathogen antigen within a pathogen structures different from the natural native pathogen structure for that antigen of interest. Swapping of pathogen antigens or hybrid chimeric pathogen constructions could be extremely useful for preparations of pathogen antigens that are either not able to be grown, poorly expressed, or poorly released from cellular membranes in culture [such as, but not limited to hepatitis A, B, C, human herpesvirus (HHV)-6, -7, -8 viruses]. In addition, swapped or hybrid pathogen constructions could be a means to express pathogens whose structures are unstable during production and/or purification of the native pathogen that naturally express that antigen (such as, but not limited to Rubella). The present invention simplifies the process of pathogen antigen production over direct infection of host cells by decreasing: (i) labor, (ii) manipulation time, and (iii) expense associated with pathogen antigen production by establishing a process that is generic in design.
In one aspect, the invention provides a pathogen antigen preparation containing and expressing all possible antigens by either the introduction of the pathogen by direct infection with the pathogen itself, or transfection by chemical and/or mechanical means by the introduction of a molecular clone of the pathogen into a pre-screened cell line shown to be resistant to or capable of adapting to pathogen antigen expression that are normally detrimental to cell survival. In one embodiment of this aspect, the molecular clone or a nucleic acid preparation containing the pathogen genetic sequence is introduced into a cell line by transfection, which bypasses the cellular membrane to gain access to the cellular chromatin structure. Integration occurs and the cell adapts to the pathogen cytopathic deleterious effect on the cell by decreasing (down-regulating) or eliminating the pathogen cell surface membrane receptors. By this process or by other processes (presently identified or not) that similarly result in the ability of the pathogen-harboring-cell to survive and propagate in culture, a chronically expressing pathogen containing cell line is established (see EXAMPLE 1). In another embodiment, the established pathogen containing line is induced by chemical or mechanical means to enhance the production (on the DNA, RNA, protein, or release level) of pathogen output and hence, the ultimate yield of the pathogen antigens. Yield enhancement could occur by one or more inducers (chemical, mechanical or biological) added simultaneously or sequentially in order to obtain the desired results (see EXAMPLE 2).
In another aspect, the invention provides a method to virally transduce [including but not limited to murine leukemia virus (MuLV), adenovirus, adeno-associated virus (AAV), lentivirus, and canarypox vectors] specific pathogen antigen(s) into a cell line for the purpose of over-expressing one or more of the pathogen antigens. In one embodiment of this aspect, the transduced specific pathogen antigen is membrane-bound in the transduced cell in such a fashion that the pathogen antigen will be specifically incorporated or acquired (by either a passive or active process). In this embodiment, the transduced over-expressed pathogen antigen(s) associate with expressed competent intact virus or virus-like particle (VLP) core structures. Association of the specific pathogen antigen(s) with the released competent intact virus—replication competent, or not—or VLP could be enhanced by the inclusion of known sequences in a hybrid recombinant construction with the pathogen antigen, but these hybrid constructions are not necessarily required. These specific sequences could be intracellular/transmembrane sequences or sequences identified to enhance the association of the pathogen antigen to the competent intact virus or VLP. In addition, the competent intact virus or VLP that provides the “carrier function” for the pathogen antigen need not be related to the pathogen antigen in question, but could be a heterologous competent intact virus and/or VLP. However, it could be the pathogen and/or VLP itself and in that case (where the “carry function” is being performed by a VLP of the pathogen), the hybrid recombinant construction with the pathogen antigen could be required for VLP release from the cell. Preferably, the transduced cell line is an established cell line expressing either competent intact viruses or VLP, although it could be a cell line where establishment of the chronic competent intact virus or VLP is introduced after pathogen antigen transduction (see EXAMPLE 3). The invention allows for the “swapping” of antigens with similar functions between pathogen and hybrid constructions, where fusion molecules are created for the purpose of expressing specific pathogen antigens within the backbone structure of another pathogen. The second pathogen provides only a carrier function and is there solely for the expression of the specific pathogen antigen of interest. The swapping or inclusion of antigens could be variant-forms of the same pathogen antigen (see EXAMPLE 4). This concept allows pathogen antigen cassettes to be created for specific antigens of interest into a particular carrier platform (see EXAMPLE 5).
In another aspect the invention provides a reproducible source of pathogen specific nucleic acid preparations of DNA and RNA for detection and quantification purposes. This nucleic acid material could be used in nucleic acid based detection and/or quantification test systems as a positive control reagent, but need not be limited to this role. The number of copies of pathogen-specific sequences could be quantified by comparing signal intensities (ELISA-based probe-dependent readings) with cloned fragments after oligonucleotide-dependent polymerase chain reactions (PCR) assays. For RNA, a reverse transcriptase step would be performed prior to PCR analysis. In another embodiment of this aspect, instead of using the purified nucleic acids with known copy number, intact virus particles obtained from harvested supernatants of chronic pathogen containing cell lines could be quantified for pathogen nucleic acid copy number and used in known amounts “spiked” into duplicate samples to determine percent recovery of pathogen specific material from human specimens and/or tissues. In this way the present invention can serve as reagent material for both antigen-based and nucleic acid-based detection kits for the research and diagnostic industry.
In another aspect the invention relates to any antigen that could be expressed on, in, or within a virus or virus-like-particle. In one embodiment of this aspect, the antigen is a tumor antigen for a particular form of cancer and used as a diagnostic indicator for progression of the disease. In another embodiment of this aspect, the tumor antigen is a therapeutic product and used to alert the immune system to mount a response against the tumor (see EXAMPLE 6). The invention allows the expression of any protein used for reagent, diagnostic, research, or therapeutic purposes assembled into a virus or virus-like-particle that is released from an established chronically expressing cell line for the purpose of harvesting the antigen by collecting and/or concentrating the virus or virus-like-particle released into the culture supernatant. The major advantage of associating the antigen with a virus or virus-like-particle is the ease of recovering said antigen at a lower cost using generic technology to harvest the antigen when associate with a particle released from an established expressing cell line rather than the antigen released in a soluble-form. Once harvested from the culture supernatant, the antigen-associated particle could be used directly, the particle could be disrupted to form a lysate, or the antigen could be partially and/or fully purified from particle associated material by standard methods used in the art of protein purification. Harvesting could be by ultracentrifugation or by low-speed centrifugation either by differential sedimentation or in combination with techniques to remove or precipitate particulate material from culture fluids. The invention improves current methods of antigen production by providing a method that increase yield, stability, and concentrates antigens of interest. Once concentrated, downstream processing and/or purification of the antigen(s) are simplified. This aspect expands the concept of antigen production from pathogen antigens to the production of any antigen/protein of choice.
In summary, the formation and establishment of stable chronically expressing pathogen containing cell lines has a wide range of applications, including but not limited to, in vitro preparation of pathogen antigens, DNA, and RNA for pathogen detection and quantification for use as reagents in diagnostic test for research and industry. The present invention provides a method to form pathogen expressing cell lines. These lines are formed by either direct infection by standard methods or by bypassing cell surface receptors to introduce the pathogen nucleic acid material into a cell of choice. The cell of choice could be prescreen to tolerate the continuous expression and assemble of pathogen particles that are released from the cell, or can be introduced into a cell that does not naturally express the receptor needed for entry, or can be genetically modified to harbor and expression the host pathogen by specific addition or deletion of signals that maintains cellular viability. Specific pathogen antigens can be expressed: (i) as the entire pathogen integrated into the cellular chromatin structure; (ii) as a specific pathogen antigen whose expression is required for the assemble of the pathogen particle; or (iii) as a specific pathogen antigen that associates with another pathogen strain (related or distal to the pathogen of interest) that provides a carrier function to said pathogen antigen. In the latter two cases, the pathogen antigen can be unmodified containing its innate sequence or could be genetically modified by standard procedures to enhance its incorporation into either homologous or heterologous pathogen particles. Thus, disclosed are methods for the formation and establishment of chronic expressing pathogen containing cell lines.
The present invention particularly concerns:
A method for establishing a cell line that expresses a pathogen to levels 10-to 1,000-fold greater than that attained by standard procedures of direct infection and expansion. This level of pathogen production is attained by establishing conditions to generate multiple integration of the pathogen genome into the host cell line, maintaining the cell line through the critical period of adaptation to tolerate this level of pathogen production, elucidating through experimentation the sequence and timed additions of reagents to the culture to further increase pathogen production, and elucidating a method for efficient intact pathogen isolation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further described by the accompanying drawings and the description thereof herein, although neither is a limitation of the scope of the invention.
FIG. 1 shows analysis by SDS-PAGE gel electrophoresis (Lane 2) of protein bands associated with proteins endogenous to an uninfected CD4 positive T-lymphocyte cell line (A3.01), and (Lane 3) the absence of cellular proteins in lysates (detergent disrupted preparation) made from particles released into the culture fluid of the same CD4 positive cell line that chronically expresses human immunodeficiency virus type-1 (HIV-1 HXB2 ) particles. Further analysis of the HIV-1 containing lysate by Western Blot illustrates the detection and the presence of all HIV-1 processed and unprocessed proteins. The env gene codes for a protein called gp160 that is broken down by a viral enzyme to form gp120 and gp41, the components of Env. The gag gene codes a precursor p61/55/51 that is then cleaved to p24 and p17—the HIV matrix protein; the pol gene codes for the p31 protein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to the establishment of cell lines containing and expressing pathogens that have been constructed in such a way as to not kill the host cell. The cell lines maintain continuous pathogen expression without cellular destruction, because the cells are modified or adapted in such a way that pathogens that are normally detrimental to the cell are no longer detrimental to the cell due to said changes in cellular physiology. The pathogen could be the entire pathogen genome integrated in the host cell line, or be composed of sequences expressing a pathogen antigen(s) of interest that is dependent on packaging and exportation from a given cell by a virus dependent carrier process. In the case of the entire pathogen genome, expression of the pathogen is dependent on the intrinsic ability of the pathogen to assemble pathogen particles that are released from the cell without cellular destruction. Pathogen expression without cell death allows for continuous pathogen expression and accumulation of the pathogen particles in the culture supernatant. The pathogen particles can be collected by procedures of ultracentrifugation or preferably by selective dehydration and precipitation (use of polyethylene glycol or similar agents), affinity and/or size dependent chromatography: (i) to increase yield; (ii) to prevent shearing of external pathogen antigens from the pathogen surface during pathogen harvest and concentration; (iii) to decrease costs associated with labor, equipment, and machinery; (iv) to decrease the volume of culture supernatant required to obtain the same quantities of pathogen needed by more conventional methods. By harvesting the said pathogens by these non-conventional methods the final product is improved, allowing better performance, over a shorter period of time, and at lower production costs. Conventional method of large-scale pathogen formation where the pathogen is infected into a host cell line with the addition of uninfected cells to support pathogen propagation, monitoring the infection to insure viral spread, maintenance and release of the pathogen, and continuous flow ultracentrifugation are all eliminated. The conventional process is replaced with a process generic in design—cellular expansion of an established pathogen containing cell line, followed by low-speed centrifugation harvest.
The present invention relates to, but is not limited to, reagents and diagnostics. The enriched pathogen preparation can be inactivated by standard procedures (that include, but not limited to UV-AMT, gamma-irradiation, zinc-finger inhibitors) that maintain pathogen particle integrity for use in vaccine preparations in vivo, therapeutic immune enhancement in vivo or in vitro, a reagent to monitor therapeutic or immune responses in vivo or in vitro, and for quantification and/or detection purposes. For similar therapeutic, diagnostic, and/or reagent use, the enriched pathogen preparation can be detergent disrupted and use as a lysate containing pathogen antigens, DNA, and RNA for protein and nucleic acid purification, or as a partial fractionated or unfractionated pathogen containing preparation. The present invention provides for use of intact or disrupted pathogens as an immunoprophylactic, immunotherapeutic, or vaccine candidate to treat, for example, infectious diseases, cancer, neurological disorders, exposure to toxins, and as an alternative to conventional drug and/or antibiotic therapies on which host resistance has developed. In pursuant of the present invention, HIV-1 was chosen as an example of a pathogen in which a permanent cell line continuously expressing HIV-1 was established. However, permanent cell line expressing any pathogen can be established. Although the introduction of the entire pathogen genome may generally be desired, in some cases, whether it is due to the cells selected or to the pathogen being expressed, nuances related to the pathogen life cycle or expressed genes, the invention can also relate to virus-like-particles (VLPs). Noninfectious viral particles can also be engineered to contain structural core proteins that assemble or acquire specific pathogen antigen(s) either homologous or heterologous to the viral structural core proteins. These synthetic particles do not replicate, but rather produce pseudovirions that carry a particle pathogen antigen(s) that are released from the cell and allow harvesting of the pathogen from the culture supernatant in a non-infectious form. The invention is envisioned as a general way of constructing and expressing pathogen antigens. Virus and/or virus-like-particles are easier to produce and purified than recombinant pathogen antigens and as such the present invention has advantages over recombinant procedures to produce pathogen antigens. Production of these antigens in mammalian cells further insures appropriate post-modification (that include, but not limited to glycosylation, polyADP-ribosylation, myristylation) of the pathogen antigen—modifications that enhance antibody-antigen reactivity/avidity and induction of immune responses.
The chronic expressing pathogen containing cell lines described herein establish an ideal system for obtaining enriched preparations of pathogen antigen, DNA, and RNA that could be used in assessing the presence of a pathogen in human tissues and/or bodily fluids. Those infected with a pathogen usually respond to the pathogen by stimulating the production of antibodies against proteins coded by the pathogen. Diagnose of pathogen infection can be determined by antibody testing. Large numbers of samples are screened by enzyme-linked immunosorbent assay (ELISA) analysis to evaluate the presence of antibodies in the general population of samples being tested. Further testing of positive samples are required and recommended by testing positive samples with assays demonstrating increased sensitivity and specificity; Western Blot analysis often function as such a confirmatory test. These diagnostic tests, whether for clinical or research purposes, require pathogen material in the form of a lysate to detect the specific pathogen infection. Since it may take antibodies against a pathogen as long as six months to be produced, diagnostic assays based on the presence of pathogen antigen and/or nucleic acids are also being developed, in addition to antibody-based testing. These assays detect the pathogen itself, instead of the immune response against the pathogen. Further tests being developed are measuring the ability of the patients' immune system to respond to a pathogen. These responses can form the bases of vaccine and/or therapeutic intervention strategies to test the ability of an intervention or preventative experimental procedures to demonstrate efficacy in an individual before initiating the study—a putative entrance criteria. The present invention is intended as a consistent supply of pathogen-derived material for the above purposes.
Pathogens against which the present invention may be applicable in the formation of chronic pathogen antigen(s) expressing cell lines include, but are limited to bacteria, parasites, protozoa, fungi, prion, and viruses. Viruses are infectious agents (pathogens) including hepatitis B, hepatitis C, herpes simplex virus, varicella zoster, Epstein-Barr virus, cytomegalovirus, human herpesvirus-6, -7, -8, HIV-1, HIV-2, HTLV-1, HTLV-2, Rubella, Rubeola, Influenza, Rotavirus, West Nile, Dengue and other emerging flaviviruses. Prions are the transmissible pathogenic agents responsible for diseases such as scrapie, bovine spongiform encephalopathy, and associated human diseases. Fungi, protozoa and parasites include Toxoplasma, trypanosomes, babesia, rickettsia, malaria, and enteric pathogens. Bacteria include species of Chlamydia, Helicobacter, Neisseria, Mycobacteria, (especially M. tuberculosi ). The scientific literature identifies 1,415 species of infectious organism known to be pathogenic to humans, including 217 viruses and prions, 538 bacteria and rickettsia, 307 fungi, 66 protozoa and 287 helminthes. Out of these, 868 (61%) are zoonotic, that is, they can be transmitted between humans and animals, and 175 pathogenic species are associated with diseases considered to be “emerging”. Over 100 viruses have been associated with acute central nervous system infections, causing among other diseases encephalitis and meningitis; Nipah virus in Malaysia and neurovirulent enterovirus (70 strains) that cause severe neurological disease; vector borne disease agents include Japanese encephalitis, Barmah Forest, Ross River, and Chikungunya viruses; hendra virus, formerly called equine morbillivirus a rabies-related virus, Australian bat lyssavirus, and a virus associated with porcine stillbirths and malformations, Menangle virus. Most emerging viruses are zoonotic and because of the large number of present and emerging pathogens that infect human are zoonotic, veterinary viral-delivered vaccinology strategies are also encompassed within the scope of the invention.
Antigens against which the present invention may be applicable in the formation of chronic antigen(s) expressing cells lines include polypeptides encoded by the pathogen listed above. The multitudes of antigens encoded by these agents that may be expressed include, but are not limited to external surface proteins and structure proteins including enzymes, transcription factors, and other cell regulatory molecules. For example, antigens encoded by any genes of the HIV-1 genome including gag, pol vif vpr, vpu, tat, rev, env, and nef may be all present as either intact antigens or immune dominate peptides. Another example is the pathogenic prion protein (PrPSc) template and endogenous cellular prion protein (PrPC). In addition, tumor antigens are included in the scope of this invention. Two types of antigens have been identified on tumor cells: Tumor-specific transplantation antigens (TSTAs) that are unique to cancer cells, and tumor-associated transplantation antigens (TATAs) that are found on both cancer and normal cells. Thus, tumor antigens consist of TSTAs, TATAs, and oncogene proteins. Tumor-specific antigens have been identified on tumors induced by chemical and physical carcinogens and some virally induced tumors. The antigen(s) can be present within the chronic expressing pathogen containing cell line as part of an infectious process, naturally native to the cell, transduced or transfected by biological (viral vectors), chemical (liposomes), or mechanical (electroporation) methods. The pathogen antigen could be expressed and assembled into the pathogen itself, or associated with a different pathogen particle.
The following examples further illustrate experiments using established chronic pathogen containing cell lines that have demonstrated reduction to practice and utility of selected preferred embodiments of the present invention, although they are in no way a limitation of the teachings or disclosure of the present invention as set forth herein.
EXAMPLE 1
Electroporation of a Molecular Clone of HIV-1 HXB2 into a Cell Line Screened to Support HIV-1 Expression while Maintaining Host Cell Survival and Propagation
Establishment of a cell line that continuously produces and expresses infectious HIV-1 demonstrates the principle of this invention.
A series of transformed CD4 positive T-lymphocyte cell lines were tested by infection of the cells with infectious HIV-1 and determining the ability of the cells to continue to grow in culture. All lines infected with HIV-1 expressed virus as monitored by p24 antigen capture assay analyses and after 2 to 4 weeks stopped growing, appearing to die. Cultures were keep in a 37° C. incubator for an extended period of time and one cell line after 3 months started to grow as first detected by a change in the color of the media (from deep red to yellow) due to the oxidation of phenol-red present in the media. This line was further propagated by the addition of fresh media and assayed for HIV-1 coded p24 released into the supernatants of the culture. The assay showed the presence of HIV-1, suggesting that the recovered cells were propagating in the presence of the continuous expression of HIV-1.
To increase the number of copies (and presumably virual expression) of HIV-1 integrated into the cellular genome, a molecular clone of HIV-1—HXB2, was electroporated into the uninfected parental cell line. The parental line was the CD4 positive T-lymphocyte cell line, A3.01, that propagated in the presence of continuous HIV-1 expression. The procedure introduces the viral genome into the host cell for integration into the host cell chromatin structure; bypassing the usual CD4 receptor mediated entry of this pathogen into cells. After months of incubation at 37° C., a cell line immersed that propagated HIV-1 continuously without cell death. The cell population was cloned in 96-well microtiter plates by limited-dilution and the cell line established. A Western Blot of a lysate of particles released from this cell line exposed to a HIV-1 positive plasma sample is shown in FIG. 1 .
This line is unlike any HIV-containing cell line previously made (which include, for example ACH-2 and U1) in that expression of infectious virus does not require induction. This cell line constitutively express >4×10 6 picograms of p24 antigen per milliliter within the first 16 hours (>0.4 ug/rl/hr) when cultured in fresh media.
EXAMPLE 2
Established Chronic HIV-Expressing Cell Lines can be further Induced to Increase Pathogen Expression
The principle of this invention is further demonstrated by the ability to enhance HIV-1 pathogen expression by physical, chemical and/or biological methods.
Conditions were established to transiently further increase HIV-1 production from the established continually HIV-1 expressing cell line. Different inducers in combination and at different times of addition were tested to determine the maximal expression of HIV-1 possible from the established continual HIV-1 expressing cell line. The result of an experiment is shown in the accompanying table.
TABLE 1 HIV-1 p24 Antigen Expression Treatment (per ml per 2days) without 20 ug with 290 ug 1,000 × conc. 12 mg
The ability to grow, induce, and concentrate an enriched preparation of the HIV-1 pathogen to over 10 mg per liter of supernatant allows gram quantities of this pathogen from 100 liters of culture.
EXAMPLE 3
Transduction of Cells with Specific Pathogen Antigen(s) and Incorporation of the Antigen(s) into a Virus or a Virus-Like-Particle
The principle of this invention could be further demonstrated by experiments using established pathogen expressing cell lines transduced with a heterologous pathogen antigen or antigens that are incorporated or acquired by a virus particle during virus assembly and is therefore released from the cell and can be recovered in the supernatant. The assembled virion could be an infectious pathogen or a non-infectious virus-like-particle. Furthermore, the heterologous pathogen antigen or antigens could contain sequences that would allow specific incorporation into the assembling virion as a prerequisite for virion release or to insure association with the released virion. The heterologous pathogen antigen or antigens could be expressed as a membrane bound molecule on the transduced established pathogen expressing cell lines where it would be displayed on the released virion surface or could be non-membrane bound and associate with the released virion core structure.
EXAMPLE 4
Transduction of a Pathogen Antigenic Region from Different Strains or Isolates to Broad or Direct Immune Responses
The principle of this invention could be further demonstrated by experiments where modified antigenic sequences are transduced into pathogen established cell line in order to broad or enhance the immune response. This approach could be most useful with pathogens that are continually changing to evade immune responses or to pathogens strains or isolated found prevalent to a particle geographical area. An example is HIV/AIDS disease and Influenza/Flu disease (but not limited to these pathogens), where viral coat protein evades host immune responses by sequence variations. In this case, different envelope sequences could be expressed and displayed on the same virus particle.
EXAMPLE 5
Construction of Hybrid Envelope Cassette Structures that Assembled into a Virus Particle within a Viral Packaging Cell Line
The principle of this invention could be further demonstrated by experiments using hybrid envelope cassette cloning vectors where an established packaging cell line is constructed. The cloning vector would allow an in-phase translational reading of the pathogen antigen fused to an intracellular-transmembrane sequence that is incorporated into the virus by the components supplied by the established packaging cell line. This would be most useful for those pathogens that are either hard to grow, not fully characterized, or difficult to purify. Examples of such pathogen include, but not limited to rubella and hepatitis, where the surface antigens of these pathogens could be cloned and expressed on a virus assembled in a retrovirus, herpesvirus, or other vector within an established packaging cell line.
EXAMPLE 6
Transduction of Tumor Antigens and Inclusion into Cellular Releases Particles
The principle of this invention could be further demonstrated by experiments using established cell lines expressing virus or virus-like-particle incorporating a tumor antigen called Globo H. This antigen is found on the surface of many cancers, including prostrate and breast cancer. Chronic cell lines expressing Globo H could be constructed and the particles released from the cell and harvested from the culture supernatant could be used as reagents for diagnostic purposes or therapeutically for the induction of immune responses.
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as maybe applied to the essential features herein before set forth.
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This application provides a method to establish and construct cell lines expressing pathogens without destruction of the host cells. The invention allows for the formation of cell lines for the purpose of continuous expression, release, and harvesting of the pathogen and maintain the consistency of the final biological pro duct. Although the invention is intended for pathogen antigen expression, the invention allows for the production of any antigen by the described methods. The establishment of a chronically infected celline can be used for reagent, diagnostic, quantification, or vaccine purposes. We have used the procedure to select for a host cell line that naturally adapts to HIV-1 replication without affecting the host cell's ability to survive. This allowed for the establishment of a chronic HIV-1 expressing cell line that continuously expresses HIV-1 particles.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/123,582, filed on Mar. 10, 1999.
BACKGROUND
This disclosure relates to integrated circuit fabrication.
As integrated circuit (IC) fabrication technique advances, semiconductor manufacturers continue to develop techniques to construct integrated circuits with structures having dimensions in the sub-micron range on a semiconductor substrate. Improvements in photolithographic processing techniques have substantially contributed to the miniaturization of active semiconductor devices to dimensions below a single micron. The fabrication of these semiconductor devices often involves the transfer of circuit patterns from a photolithographic mask or reticle onto a photoresist layer. The process uses an imaging lens apparatus.
The reticle is often itself constructed from a substrate of silicon dioxide. The reticle can be patterned with areas of differing transmissivity thereon. The patterned areas of the reticle represent either the positive or negative images of an integrated circuit structure. After being properly positioned and aligned over the semiconductor wafer, the reticle is subjected to electromagnetic radiation. The radiation passes through transparent portions of the reticle, striking portions of the photoresist layer on the wafer. The resist coating is developed and etched so as to impart a positive or negative image of the reticle pattern onto the photoresist layer remaining on the wafer.
Conventional photolithographic methods of fabricating integrated circuits on a substrate often involve stepping a reticle and imaging apparatus across a photoresist coated wafer. The methods also involve repeatedly transferring the reticle image pattern to adjacent areas on the wafer. Each of the individual areas on the wafer containing the circuitry image is termed a die. The wafer is cut or otherwise segmented at the end of the fabrication process so that the dice are separated from one another for subsequent packaging as individual integrated circuit chips.
As integrated circuits become increasingly complex, however, the integrated circuit structures within an individual die have become significantly smaller and denser. Larger reticles are often required to transfer larger and more complex circuit images to substrate fields of increased dimensions. Because of inherent image resolution limitations associated with conventional photolithographic processes, imaging and alignment errors are often introduced when fine line structures having sub-micron dimensions are produced on relatively large reticles. Further, steppers used in photolithographic process also set the limit on the size of the printed circuit.
SUMMARY
The inherent limitations associated with producing relatively large reticles having structures with sub-micron dimensions have motivated development of different types of integrated circuits (IC) with larger fields. One type of circuit includes a plurality of circuit blocks formed on a semiconductor substrate. The circuit blocks are stitched together by appropriately connecting input and output lines of the plurality of circuit blocks. The circuit also includes connecting circuits coupled to the plurality of circuit blocks. The connecting circuits provide low voltage drop across boundaries where the plurality of circuit blocks are stitched together.
BRIEF DESCRIPTION OF THE DRAWINGS
Different aspects of the disclosure will be described in reference to the accompanying drawings wherein:
FIG.1 shows a substrate having a composite field fabricated using stitching technique in accordance with one aspect of the present invention;
FIG. 2 shows sub-fields on a reticle corresponding to each function block;
FIG. 3 is a schematic diagram of a row select circuit in accordance with one aspect of the present invention; and
FIG. 4 is a schematic diagram of a shift register in accordance with one aspect of the present invention.
DETAILED DESCRIPTION
The inherent limitations associated with producing relatively large reticles having structures with sub-micron dimensions have motivated development of new methods of fabricating integrated circuits (IC) with larger fields. One such photocomposition method, known as “stitching,” is directed to producing larger reticle fields by sub-dividing the circuitry pattern. The sub-field patterns are then stitched or recomposed to form a large composite circuit field thereon.
As illustrated in FIG. 1 of the drawings, a substrate having a field 100 is shown as a composite field fabricated using the stitching technique. Often, a field 100 is image patterns of an integrated circuit structure. In the illustrated embodiment, the field 100 is a representation of the image patterns of a large image sensor having a large pixel sensor array 102 - 116 . The large image sensors are well suited for stitching because many parts of the sensors are duplicative.
The substrate circuit is constructed by first photolithographically patterning smaller sub-fields 120 , 130 , 140 , 150 , with each sub-field bearing a portion of the image pattern of the integrated circuit structure. The sub-fields 120 , 130 , 140 , 150 are then stitched together along stitching boundaries 124 , 134 , 144 , 152 , 160 , 170 , 180 to form the composite field 100 . The image patterns of sub-fields 120 , 130 , 140 , 150 substantially adjoin each other with a high accuracy in order to avoid any alignment errors that otherwise occur with respect to the millions of fine line interconnections necessary to “re-connect” adjacent sub-fields along the stitching boundaries 124 , 134 , 144 , 152 , 160 , 170 , 180 . Each of the sub-fields 120 , 130 , 140 , 150 contains one or more functional blocks, which together form a complex integrated system.
For some embodiments of the large image sensors, there are areas near the stitching boundaries 124 , 134 , 144 , 152 , 160 , 170 , 180 where there are no pixel coverage. To minimize the area with no pixel coverage, a shift register for the row select and reset select circuit have been incorporated into the middle of the pixel array. The circuit field 100 of the large image sensor includes a pixel sensor array 102 - 116 , pixel signal routing areas 122 , 132 , 136 , 142 , 146 , a row logic 134 , 144 , a column logic 154 , and a readout logic 156 .
Individual sets of reticles are initially patterned with images representative of the circuitry structures comprising each of the function blocks 102 - 116 , 122 - 124 , 132 - 136 , 142 - 146 , 152 - 156 . Each function block is preferably defined within a single field on the reticle 200 as shown in FIG. 2 . For example, the field 1 corresponds to the function blocks 106 - 112 while the field 3 corresponds to the function blocks 102 , 104 . The image patterns comprising each of the fields on the reticle 200 corresponding to the function blocks 102 - 116 , 122 - 124 , 132 - 136 , 142 - 146 , 152 - 156 are then transferred to the substrate. Upon completion of the initial transfer of function block image patterns from the individual fields to the substrate, each of the function block patterns on the field 100 can be considered to be electrically independent with respect to all other function blocks. Considering, for example, function blocks 102 - 116 , a plurality of row and column pixel currents flow through the lines and preferably terminate at predetermined locations along the perimeters of the blocks 102 - 116 . To minimize the voltage drops across the areas between the blocks 102 - 116 , the areas 124 , 134 , 144 , 152 have been designed with stitching circuits, such as row and column select circuits having shift registers. These circuits are designed with minimal power dissipation.
FIGS. 3 and 4 illustrate the row select circuit 300 and the shift register 400 in accordance with one aspect of the present invention. To minimize the logic, the shift register 400 shown in FIG. 4 can implement the column select logic as well. The row select circuit 300 selects the row 302 indicated by the input 304 at the edge of the clock signal 306 . The input 304 can be reset with a reset signal 308 . The selected row 302 can be reset with an Srst signal 310 . The global reset signal 312 , Grst, resets the entire array.
The shift register 400 receives a clock signal and sends the signal to the gate terminals of the transistors Q 1 , Q 2 , and Q 4 . The input signal drives the gate terminal of the transistor Q 3 . The transistor Q 3 , in conjunction with the transistor Q 4 , drives the node 402 either to high (V DD ) or low voltage (V SS ), depending on the voltage level of the input signal. The node 402 can be pulled up through the transistors Q 10 and Q 11 . The pull-up is triggered by the clock signal using the transistors Q 9 , Q 12 , and Q 13 . The node 402 can be pulled down through the transistors Q 3 and Q 4 . The pull-down is triggered by the inverse clock signal using the transistors Q 5 and Q 6 . The transistor Q 5 drives the output. The transistors Q 14 to Q 19 drive the inverse output. The shift register 400 can be reset by a reset signal through the transistor Q 7 .
With the stitched circuit of the present invention, resolution can be increased without reducing the field size or increasing the lens size. An area larger than the maximum reticle size can be formed by appropriately stitching the blocks with row and column select circuits and shift registers in accordance with some aspects of the present invention. The resultant area has increased the resolution producible with lens without increasing the lens size or decreasing the field size.
Accordingly, the complexity and functionality of each function block may be dramatically increased, resulting in large part from the ability to utilize a maximum available reticle field area for the integrated circuitry defining each function block.
Above described aspects and embodiments are for illustrative purposes only. Other embodiments and variations are possible. For example, the concept of connecting the seams with select circuits and shift registers can be used in circuits other than the image sensors, such as any integrated circuits having large duplicative areas.
All these are intended to be encompassed by the following claims.
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A circuit having a plurality of circuit blocks formed on a semiconductor substrate is disclosed. The circuit blocks are stitched together by appropriately connecting input and output lines of the plurality of circuit blocks. The circuit also includes connecting circuits coupled to the plurality of circuit blocks. The connecting circuits provide low voltage drop across boundaries where the plurality of circuit blocks are stitched together.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to a glass composition for electric lamps, and more particularly to a glass composition substantially free of lead for use in electric lamps.
[0002] Glass compositions with approx. 20% lead oxide content have been used widely in lighting industry to produce stems and exhaust tubes for different lamp families as well as envelopes for automotive and compact fluorescent lamps. Since lead oxide is a harmful pollutant, it shall be ensured that electrical and electronic equipment put on the market does not contain lead in accordance with the Directive 2002/95/EC of the European Parliament and Council.
[0003] In the last decades, oxy-fuel firings of glass melting furnaces were implemented in glass production lines of lighting industry. Gas-oxygen firing results in a firing atmosphere of high partial vapour pressure of water, which influences glass fining process.
[0004] EP Patent No. 603 933 describes a lead free glass composition for use in electric lamps as stem glass as well as envelopes for compact fluorescent lamps. CeO2 is added in an amount of up to 0.2% by weight to improve UV absorption of the glass composition. In a starting batch of the glass composition, Na 2 SO 4 is used as a fining agent.
[0005] U.S. Pat. No. 5,843,856 discloses a lead free glass composition for electric lamps comprising SiO 2 , Al 2 O 3 , Na 2 O, K 2 O and B 2 O 3 as well as optionally Li 2 O, CaO, MgO, SrO, Sb 2 O 3 , Fe 2 O 3 , MnO 2 and/or CeO 2 . In addition, the glass composition contains ZnO and optionally TiO 2 and/or P 2 O 5 .
[0006] U.S. Pat. No. 5,843,855 describes a lead free glass composition for electric lamps, in which the glass contains only a small amount of BaO and production cost of the glass does not differ considerably from that of a traditional glass containing lead.
[0007] U.S. Pat. No. 5,885,915 describes a glass composition for electric lamps comprising neither PbO nor BaO or optionally ZnO while its characteristics determining the use for electric lamps are equivalent to or better than known compositions containing BaO.
[0008] None of the glass compositions disclosed in the patents above simultaneously fulfills all the requirements of electrically highly resistive stem glass, highly effective UV absorption up to 320 nm and stable fining and melting process with improved capability for production of good quality low cost glass even in oxy-fuel fired furnaces.
[0009] There is a particular need for developing an economic lead free glass composition with more effective UV absorption and produced by oxy-fuel fired furnaces for stems and envelopes of electric lamps and even for envelopes of compact fluorescent lamps that include bulky plastic parts or fit into plastic fixtures.
SUMMARY OF THE INVENTION
[0010] In an exemplary embodiment of the invention, a glass composition is provided for parts of electric lamps that is substantially free of PbO and comprises components in percentage by weight as follows:
SiO 2 60-72 Al 2 O 3 1-5 Li 2 O 0.5-1.5 Na 2 O 5-9 K 2 O 3-7 MgO 1-2 CaO 1-3 SrO 1-5 BaO 7-11 Fe 2 O 3 0.03-0.06 Sb 2 O 3 0.1-0.5 CeO 2 0.3-0.7
[0011] The use of this glass composition has substantial advantages over the prior art. The glass material of this composition has an excellent UV absorption, which also meets the requirements of compact fluorescent lamps with plastic fixtures. Melting, fining and shaping processes are better controlled. This glass composition can replace the lead containing glass materials used widely in all area of lamp production.
BRIEF DESCRIPTION OF DRAWINGS
[0012] The invention will now be described with reference to enclosed drawings where:
[0013] FIG. 1 shows a graph of UV absorption curves varying with the quantity of CeO 2 content in the glass,
[0014] FIG. 2 shows a graph of the area fraction of bubbles in the glass melt during melting process,
[0015] FIG. 3 shows a view of a compact fluorescent lamp with bulky plastic parts, and
[0016] FIG. 4 shows a schematic view of a stem for an electric lamp.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The glass material made of the proposed lead free glass composition fulfills the requirement of improved UV absorption of envelopes of compact fluorescent lamps that have bulky plastic parts and fit into plastic fixtures. Due to technical parameters of this glass material, it can be used in all area of lamp production lines instead of lead containing glass material. Fining package composed for the production of this glass material makes the production process more economical and better controlled.
[0018] UV absorption properties of a glass composition can be improved by addition of selected components, which have absorption band in the UV range of the light. For example, iron in oxidized form has an absorption peak in UV range up to 400 nm, though absorption coefficient of this component is relatively low. Higher quantity of iron would be necessary to accomplish the required UV absorbing effect, however light transmittance in the visible range is also significantly influenced in that case, and remarkable lumen loss and colour change of the lamp appear.
[0019] Inclusion of rare earth elements, primarily cerium, has effective UV absorption in the required region without significantly influencing the light transmittance in the visible range. The UV absorption increases with increasing quantity of cerium, however absorption properties are also influenced by other glass components and the redox state of the glass.
[0020] Glass compositions were melted with different fining packages in laboratory and UV light transmittance was tested. It was found that 0.33% by weight of CeO 2 addition resulted in UV light transmittance of 1.06% at 285 nm in a glass composition with sodium sulphate, while light transmittance was 0.55% at the same wavelength in a glass composition with 0.33% by weight of CeO 2 together with antimony and nitrate. The glass was more oxidized with a fining package of antimony and nitrate. These data show that in order to accomplish improved UV absorption, it is more preferable to keep the glass in oxidized state than in reduced one.
[0021] UV absorption curves varying with the quantity of CeO 2 content can be seen in FIG. 1 . The transmittance ratio (T %) of lead free glass compositions with different CeO 2 content and leaded glass material with 0.4% by weight of CeO 2 content were measured and plotted as a function of wavelength in nanometers. To find optimum quantity of the UV absorbing component, glass compositions with different cerium-oxide contents were melted and the UV light transmittances of samples were tested. A fining package with antimony and nitrate was used. It was found by the tests that 0.5% by weight CeO 2 in a lead free glass composition provided the same absorption effect as 0.4% by weight of CeO 2 content in lead containing glass with full cut off of UV light up to 320 nm. The reason for the fact that higher quantity of CeO 2 is needed into lead free glass composition can originate from an interaction between the glass matrix and the UV absorbing components of the glass and the possible changing of redox during melting. In a further embodiment of the invention, CeO 2 in an amount of 0.4-0.6% by weight is used in order to accomplish the UV cut off at 320 nm.
[0022] The fining process of the glass depends on solubility and diffusion of gases in the melt, which are basically determined by nature of the gases, partial pressure of the gases, basicity, surface tension of the glass melt and temperatures used. Fining agents have to be selected taking these factors into account. Chemically bonded gas components of raw materials and air between grains of raw materials result in gas bubbles in the glass melt. These gaseous inclusions must be removed during the fining process and fining agents are added to the glass melt in order to support elimination of gas bubbles. The fining agents have the function of producing fining gases that will diffuse into the gas bubbles resulting in growth of these bubbles and consequent ascending and release of them.
[0023] The fining agents used mostly in glass industry are sodium sulphate and antimony trioxide. Potassium or sodium nitrate is added to ensure that antimony is dissolved in the melt in the form of Sb 2 O 5 . Sb 2 O 5 is an effective fining agent and makes the glass to be sufficiently oxidized. In a further embodiment of the invention, the glass composition, in which CeO 2 in an amount of 0.4-0.6% by weight is used, also comprises Sb 2 O 3 in an amount of 0.2-0.4% by weight. Sodium sulphate is less suitable as a fining agent in glasses, which have to be melted under strongly oxidizing conditions. The released gases in high barium content glass compositions with sulphate fining cause formation of high viscous foam in conditions of oxy-fuel melting.
[0024] Laboratory tests were made on batch samples with different fining packages in a specially designed high temperature observation furnace. In FIG. 2 , the area fraction variation of bubbles during the melting process is plotted as a function of time. Experimental conditions of laboratory furnace were set according to the atmosphere of oxy-fuel furnaces. Following the fining process, we monitored the number and growth of the bubbles in the melt after the melting temperature was reached. Batch compositions with antimony showed quick release of the bubbles. In these compositions, proportion of the antimony to the nitrate was selected from the range of 1-5 parts Sb 2 O 3 to 10-20 parts KNO 3 in a glass unit of 1000 parts and the ratio of KNO 3 /Sb 2 O 3 was in the domain of 4-8. Rate of cullet during the tests was in the range of 0-40%.
[0025] In spite of using antimony and nitrate as fining agents, in the event that a batch contained sulphate, dense foam was observed at the beginning of a melting process and a longer time was required to reach the bubble free state.
EXAMPLE
[0026] Industrial test was made with natural gas and oxygen furnace in a continuous working glass production line. Glass was melted from a batch of usual glass raw materials and cullet. The batch consisted of quartz sand, soda ash, potash ash, lithium feldspar, dolomite, barium carbonate, strontium carbonate, lithium carbonate, fining agents of antimony oxide and potassium nitrate. Cerium-oxide was added as UV absorbing dope material. The batch and the cullet were charged continuously by a screw charger. The resulted glass composition by chemical analysis was in weight percentage as follows:
SiO 2 (%) 68 Na 2 O (%) 7.3 K 2 O (%) 4.8 Li 2 O (%) 1.1 BaO (%) 8.5 SrO (%) 3 CaO (%) 1.9 MgO (%) 1.3 Al 2 O 3 (%) 3.3 Fe 2 O 3 (%) 0.04 CeO 2 (%) 0.42 Sb 2 O 3 (%) 0.20
[0027] The temperature of the furnace was controlled between 1400 and 1470° C. Melting and fining processes were stable with controllable batch blanket flow. Any unacceptable foaming was not experienced.
Tested physical properties Thermal expansion coefficient α (50-350), (1/C.) 96.4*10 −7 Glass transition temperature, Tg (C.) 478 Softening point (Littleton) T L (C.) 670 Temperature at the viscosity of 10 4 dPas, Tw(C.) 1014 Density, d (g/cm 3 ) 2.621 DC electric resistivity Tk 100 (C.) 288 UV light transmittance at λ = 300 nm for 1 mm 0 wall thickness (%) UV light transmittance at λ = 320 nm for 1 mm 0.01 wall thickness (%) UV light transmittance at λ = 340 nm for 1 mm 8.4 wall thickness (%)
[0028] In FIG. 3 , a compact fluorescent lamp of 2D form is shown. The lamp has an envelope 12 and a plastic base part 11 . The envelope of the lamp was made of a glass material originated from the industrial test above. The UV absorption of the envelope 12 was at least equal to that of an envelope made of lead containing glass composition used widely. It is envisaged that the plastic base part 11 and the plastic fixture receiving the lamp will not be adversely affected by the UV radiation of the envelope 12 made of the proposed glass compared with an envelope of lead glass, that is significant discoloration will not occur before the end of life of the lamp.
[0029] In FIG. 4 , a stem of an incandescent lamp is shown. The stem was made of the above glass material. The stem consists of a flare 22 , lead in wires 25 L, 25 R, a filament 27 and an exhaust tube 26 . The filament 27 is clamped to upper portions 29 L, 29 R of lead in wires. During the production process, the flare 22 is heated and the exhaust tube 26 and the flare 22 are melted together and an aperture in the exhaust tube 26 is blown out. An inner end 24 of the flare 22 is sealed to the upper portions 29 L, 29 R of lead in wires by pinching. The glass composition originated from the industrial test described above fulfills all of the requirements concerning technological steps of melting, tube drawing, shaping, aperture blowing and pinching. The sealing was sufficient so that no air leakage appeared.
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A glass composition for parts of electric lamps is disclosed, which is substantially free of lead and comprises the following components in percentage by weight: SiO2 60-72 Al2O3 1-5 Li2O 0.5-1.5 Na2O 5-9 K2O 3-7 MgO 1-2 CaO 1-3 Sro 1-5 BaO 7-11 Fe2O3 0.03-0.06 Sb2O3 0.1-0.5 CeO2 0.3-0.7
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical converter for generating, in response to an input optical pump beam from a laser, multi-wavelength optical output signals with variable wavelength distribution.
2. Description of the Related Art
Stimulated Raman scattering (SRS) was discovered in 1962, and has been extensively studied in atomic and molecular gasses, numerous liquids, and solids. The generation of tunable coherent radiation by means of stimulated Raman techniques is widely employed as a method for creating intense radiation over a wide range of wavelengths. A basic treatise on stimulated Raman scattering is found in "Tunable Lasers", by J. C. White, Springer Series Topics in Applied Physics, vol. 59, Springer, Berlin, Heidelberg, 1987, pp. 115-207.
It is desirable in certain applications to generate an optical signal which contains a plurality of component waves of different wavelengths, and to be able to vary the distribution of the wavelengths in the signal. Vibrational SRS in a single Raman cell in response to an input optical pump beam from a laser generally generates a single Stokes wave with a relatively large frequency shift. Rotational Raman scattering (SRRS) produces a smaller frequency shift than vibrational SRS, enabling the generation of two, or possibly three Stokes shifted waves. However, increasing the intensity of the input pump beam in an attempt to generate more Stokes shifted waves causes optical breakdown of the Raman medium in the cell at a lower intensity than that at which more waves would be generated.
Where the Raman medium is a gas such as hydrogen, methane, or deuterium, the pressure can be varied to selectively promote the generation of rotationally or vibrationally shifted waves. However, a substantial length of time is required to produce pressure variation, and at higher pressure levels which support vibrational SRS, various other phenomenon, such as stimulated Brillouin scattering (SBS), compete with SRS for pump energy. Thus, the generation of an optical signal with a variable distribution of more than two or three component wavelengths has not been achieved utilizing SRS.
SUMMARY OF THE INVENTION
In accordance with one embodiment of the present invention, a Raman converter is provided in which an input optical pump beam from a laser propagates through first and second Raman cells and causes Stokes shifted waves to be generated therein, and a polarizer, such as a Pockels cell or rotatable quartz waveplate, is disposed between the Raman cells. The polarizer is switchable to cause the Stokes shifted waves from the first Raman cell to be circularly or linearly (or optionally elliptically) polarized, thereby causing the Stokes shifted waves in the second Raman cell to be generated as rotationally shifted or vibrationally shifted waves respectively. The polarizer may be switched to the selected circular or linear polarization, or may be periodically switched therebetween at regular or pseudorandom intervals. In accordance with a preferred embodiment of the present invention, a second polarizer is disposed upstream of the first Raman cell for selectively switching the polarization of the input pump beam. In yet another embodiment of the present invention, the polarizer upstream of the first Raman cell may be used without the polarizer between the two Raman cells. Combinations of rotational and vibrational Stokes shifted waves generated in the two Raman cells provide multi-wavelength optical output signals with variable wavelength distributions.
The present invention overcomes the limitations of prior art single Raman cell converters by providing two or more Raman cells with variable polarization input to each cell. The first cell produces relatively high intensity Stokes shifted waves which act as seeds for the second and subsequent cells, thereby enabling the generation of more, and higher order SRS shifted waves than can be generated in a single Raman cell. Wavelengths may be generated in the dark red and near infrared region of 680-750 nanometers 15 (nm), in addition to the visible region of 532-630 nm to which the prior art using a 532 nm pump is currently limited. Periodic polarization switching enables rotational and vibrational Stokes shifted waves to be generated in selectable combinations, thereby providing a greater diversity of waves than has been possible in the prior art. As a further advantage of the present invention, the polarization states may be periodically switched at a speed which is much higher than that at which the pressure of the medium in the Raman cells can be varied, thereby enabling the generation of an optical wave having a time-varying wavelength distribution.
These and other features and advantages of the present invention will be apparent to those skilled in the art from the following detailed description, taken together with the accompanying drawings, in which like reference numerals refer to like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a Raman converter in accordance with one embodiment of the present invention incorporating a polarizer upstream of the first Raman cell.
FIG. 2 is a block diagram of a Raman converter in accordance with an alternative embodiment of the present invention incorporating a polarizer between two Raman cells.
FIG. 3 is a block diagram of a Raman converter in accordance with a preferred embodiment of the present invention incorporating two polarizers and two Raman cells.
FIG. 4 is a schematic diagram of a variable polarization control system for use in the present invention, employing a mechanically rotatable wave plate.
FIG. 5 is a schematic diagram of a variable polarization control system for use in the present invention, employing an electrically variable electro-optic cell.
FIGS. 6 to 12 are graphs showing relative intensity at various wavelengths measured for various embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 a Raman converter with variable wavelength distribution embodying the present invention is generally designated as 100, and includes a Raman cell 12 for generating Stokes shifted waves 14 in response to an input optical pump beam 16 from a laser 18. The pump beam 16 is focused into the Raman cell 12 by a converging lens 20; and the Stokes shifted waves 14 are re-collimated by a converging lens 22 and may be introduced into a second Raman cell (not shown).
In accordance with the present invention, a variable polarizer 32 is disposed upstream of the Raman cell 12, between the laser 18 and lens 20, and is switchable by a control unit 36 between at least two polarization states. Polarizer 32 allows the polarization of the input pump beam to be selectively switched during operation of the converter.
FIG. 2 shows an alternative embodiment of the present invention generally designated as 101, and incorporating the laser 18, optical pump beam 16, converging lenses 20 and 22, and Raman cell 12 as in FIG. 1. As shown in FIG. 2, a second Raman cell 24 is disposed downstream of the cell 12 for generating a second set of Stokes shifted waves 26 in response to the first set of Stokes shifted waves 14 from the first Raman cell 12. The waves 14 are re-collimated by converging lens 22, and then are focused into the cell 24 by a converging lens 28. The output waves 26 are re-collimated by a converging lens 30. The waves 14 also constitute a seed for the cell 24, enabling the generation of a second set of higher-order Stokes shifted waves than can be produced by a single Raman cell. A variable polarizer 34 is disposed between the lenses 22 and 28 and is switchable by control unit 36 between at least two polarization states, as described in further detail below. It should be noted that the terms "upstream" and "downstream" are used herein to designate relative position along the wave being generated, before and after, respectively, a reference point.
FIG. 3 shows a Raman converter in accordance with a preferred embodiment of the present invention, generally designated as 103, in which two polarizers are used. FIG. 3 contains all the elements of FIGS. 1 and 2, including pump beam 16 from laser 18 which passes through a first variable polarizer 32 and is then focused by converging lens 20 into first Raman cell 12. The first set of Stokes shifted waves 14 is re-collimated by converging lens 22 and is introduced into a second variable polarizer 34. The output from the second polarizer 34 is re-collimated by lens 28 and is introduced into a second Raman cell 24. The output 26, which is a second set of Stokes shifted waves from the second Raman cell 24, is re-collimated by converging lens 30. Polarizers 32 and 34 are switchable by control unit 36 between at least two polarization states. Although only two Raman cells are illustrated herein, it is within the scope of the present invention to use more than two Raman cells.
The manner in which the Stokes shifted waves are generated in the cells 12 and 24 varies in accordance with the polarization of the respective input optical beam. Generally, circular polarization will cause generation of rotational Stokes shifted waves, whereas linear polarization will cause generation of vibrational Stokes shifted waves. Elliptical polarization will cause a combination of rotational and vibrational Stokes shifted waves, depending on the degree of ellipticity.
The arrangement shown in FIG. 3 enables generation of the Stokes shifted waves 26, which constitute the optical output signal of the converter 10, with four maximally diversified wavelength distributions and an infinite number of intermediate wavelength distributions. The maximally diversified wavelength distributions result from the following polarization combinations.
(1) Polarizer 32 circular; polarizer 34 circular.
(2) Polarizer 32 circular; polarizer 34 linear.
(3) Polarizer 32 linear; polarizer 34 circular.
(4) Polarizer 32 linear; polarizer 34 linear.
The intermediate distributions result from at least one of
the polarizers 32 and 34 causing elliptical polarization of the respective optical signal.
The control unit 36 may be constructed to enable the polarizers 32 and 34 to be merely switched back and forth between, and maintained at, two or more selected polarization states at a predetermined time during a single operation sequence of the laser to provide the input optical signal to the Raman cell. Alternatively, the control unit 36 may be constructed to automatically switch the polarizers 32 and 34 between two or more polarization states during laser operation. The automatic switching may be done at regular intervals, or at pseudo-random intervals under control of a random number generator or the like (not shown) in the control unit 36. The frequency of the polarizer switching is determined by the desired output and final use. When the input optical signal is provided by a pulsed laser, the polarizer may be controlled to switch between successive input pulses so that the output spectrum distribution shifts from pulse to pulse.
The polarizers 32 and 34 may be embodied in a number of different forms within the scope of the present invention. As illustrated in FIG. 4, either or both of the polarizers 32 and 34 may include a waveplate 38 which is mechanically rotatable by a motor drive 40 under control of the control unit 36. A treatise on waveplates is found in a textbook entitled "Optics", by E. Hecht et al, Addison-Wesley, Reading, MA 1975, pp. 246-251. The most suitable material for the waveplate 38 is quartz, although the invention is not so limited. Switching between circular and linear polarization is possible, for example, where the wave plate 38 is a quarter wave plate and the respective input beam is oriented at 45° to a principal axis of the plate 38. Rotation of the plate 38 by 45° in opposite directions will generate a phase shift range of 90°, and circular or linear polarization at the respective ends of the range. Rotation to angles other than at the ends of the range will cause elliptical polarization to a degree which varies in accordance with the direction and amount of rotation.
As illustrated in FIG. 5, either or both of the polarizers 32 and 34 may include an electro-optic cell 42 such as a Pockels cell which is electro-optically variable within a range of birefringent states by means of a voltage generator 44 under control of the control unit 36. A treatise on electro-optic cells is found in a textbook entitled "Solid-State Laser Engineering", by W. Koechner, Springer-Verlag 1976, pp. 411-14 418. The Pockels cell 42 is capable of continuously varying the polarization from circular through elliptical to linear in response to a variable voltage applied to the cell 42.
Other polarizers such as a Fresnel Rhomb described in the previously referenced text by Hecht, may be utilized in practicing the present invention, although not illustrated.
The laser 18 may be a conventional frequency doubled Nd:YAG unit which produces the pump beam 16 at a wavelength of 532 nm. The beam 16 as produced by the laser 18 is coherent. The Raman cells 12 and 24 may be filled with any suitable medium which exhibits the Raman scattering effect,. including, but not limited to, hydrogen (H 2 ), deuterium (D 2 ), or methane (CH 4 ) gases. The Raman cells 12 and 24 may be filled with the same or different gases. In addition, one or both of the Raman cells may be filled with a mixture of gases.
The operation of the Raman converter of the present invention will be described with reference to FIGS. 6 to 12, which illustrate experimental results obtained for the embodiment shown in FIG. 3 with H 2 in both Raman cells. For FIGS. 6 to 11, a pump wavelength of 532 nm was used. For FIG. 12, a pump wavelength of 266 nm was used. The pressure in cell 12 and 11 pounds per square inch gauge (psig) or 0.77 kilograms per centimeter 2 (kg/cm 2 ) and the pressure in cell 24 was 25 psig or 1.76 kg/cm 2 . The input pump beam 16 had an energy of 200 millijoules (mJ) per pulse, with a 25 nanosecond (ns) pulse width, full width half maximum (FWHM). The laser 18 and lenses 20, 22, 28 and 30 were designed for focussing the respective optical signals in the cells 12 and 24 at a ratio of F/100. The polarizer was a waveplate as previously described and was manually rotated.
H 2 produces a rotational Stokes shift of 587 cm -1 , and a vibrational Stokes shift of 4155 cm -1 . These shifts result in the generation of the Stokes shifted wavelengths shown in Table I, in response to an input pump beam at 532 nm, where to notation RSx denotes a rotational Stokes shifted wave of xth order, and VSx denotes a vibrational Stokes shifted wave of xth order.
TABLE I______________________________________STOKES SHIFTED WAVELENGTHS FOR H.sub.2STOKES SHIFTED WAVELENGTHWAVE (NANOMETERS)______________________________________RS1 549RS2 567RS3 587RS4 608RS5 630RS6 655VS1 683VS1 + RS1 712VS1 + RS2 743VS1 + RS3 776VS1 + RS4 813VS1 + RS5 854VS1 + RS6 899VS2 954VS2 + RS1 1010VS2 + RS2 1074VS2 + RS3 1146______________________________________
The data illustrated in FIGS. 6 to 12 was generated with an Optical Multichannel Analyzer (not shown), obtained from EG&G Princeton Applied Research, Model No. OMA-III, consisting of a monochrometer to spectrally disperse the output Stokes shifted waves 26 after re-collimation by the lens 30, a linear detector to measure the relative intensities of the component wavelengths, and a computer/software system to analyze and display the results.
FIG. 6 illustrates the embodiment where both polarizers 32 and 34 were switched to cause circular polarization. The residual pump beam at 532 nm is designated as RP. Although circular polarization caused the wavelength distribution to consist mainly of the shorter wavelength rotational Stokes shifted waves RS1 to RS6, smaller amplitude vibrational Stokes waves VS1 +RSx were also present. This is not unexpected, since the higher pressure in the Raman cell 24 promoted generation of vibrational rather than rotational Stokes shifted waves.
FIG. 7 illustrates the embodiment where the polarizer 32 was switched to circular polarization and the polarizer 34 was switched to linear polarization. It will be noted that in FIG. 7 the relative amplitudes of the rotational Stokes shifted waves are lower than in FIG. 6, whereas the relative amplitudes of the vibrational Stokes shifted waves are higher than in FIG. 6. In FIG. 7, the wavelengths of RSx are in the visible spectral region, whereas the wavelengths of VS1 and VS1+RSx are in the dark red to near infrared region, providing a wavelength range and diversity which were unobtainable in the prior art.
FIG. 8 illustrates the embodiment where the polarizer 32 was switched to linear polarization and the polarizer 34 was switched to circular polarization. The wavelength distribution is radically different from FIGS. 6 and 7. The output optical signal in FIG. 8 includes the residual input pump wave RP, first rotational Stokes shifted wave RS1, first vibrational Stokes shifted wave VS1, and the combination VS1+RS1, with all other wavelengths having minimal amplitude.
FIGS. 9 and 10 illustrate the embodiment where both polarizers 32 and 34 were switched to linear polarization, over different wavelength regions. The output optical signal shown in FIGS. 9 and 10 includes the residual pump wave RP, and the first and second vibrational waves VS1 and VS2 respectively. The origin of a spike which appears at approximately 880 nm in FIG. 9 is unknown.
FIG. 11 illustrates the embodiment where the polarizer 32 was switched to elliptical polarization and the polarizer 34 was switched to linear polarization. The wavelength distribution shows a combination of rotational and vibrational Stokes shifted waves. This distribution includes a first anti-Stokes wave AS1. The elliptical/ linear polarization was found to produce a more desirable distribution than the circular/linear polarization (of FIG. 8).
The pressures (11 psig and 25 psig) of the H 2 gas in the Raman cells 12 and 24 respectively were determined through a combination of knowledge of the dependence of rotational and vibrational Raman gain on pressure, and through experimentation. For the pump conditions employed, at low pressures of less than approximately 25 psig, the rotational gain exceeds the vibrational gain, and at higher pressures the opposite is true.
If the pressure in the first cell exceeds 25 psig, some photons of the vibrational wavelengths are generated and amplified in the second cell even with circular input polarization. This effect would make it impossible to achieve a substantially pure rotational wavelength distribution. Conversely, if the pressure in the second cell were significantly below 25 psig, it would be difficult to achieve a substantially pure vibrational wavelength distribution. Thus, the pressure in the first cell is optimized for generation of rotational Stokes shifted waves, whereas the pressure in the second cell is set at the threshold where the generation of rotational and vibrational shifted waves are equally promoted.
Table II gives the measured wavelength distributions as percentages of the input beam intensity for the embodiments of FIGS. 6 through 11.
TABLE II______________________________________MEASURED WAVELENGTH DISTRIBUTIONS CellWave Wavelength (nm)Cell 12 Circular Circular Linear Linear EllipticalCell 24 Circular Linear Circular Linear Linear______________________________________AS1 0 0 0 0 1.8RP 9.9 13 18.6 22.5 16.0RS1 19 17.3 19.8 0 21.4RS2 16.2 14.9 2.4 0 7.7RS3 13.7 13.4 0 0 2.0RS4 12.1 10.6 0 0 0.5RS5 6.8 5.3 0 0 0.3RS6 1.3 1.4 0 0 1.5VS1 0.5 1.0 20.4 50 9.0VS1 + RS1 1.3 1.4 22.7 0 17.8VS1 + RS2 1.8 2.9 1.2 0 6.5VS1 + RS3 2.5 3.8 0 0 1.3VS1 + RS4 0 0 0 0 0VS2 0 0 0 12.5 0______________________________________
In each case shown in Table II, the total equals 85% of the pump input energy, since 15% of the energy is lost due to heating of the Raman medium, large angle scattering, etc. FIG. 12 illustrates the embodiment of the present invention where both polarizers were oriented for circular polarization. The pump beam for FIG. 12 was 266 nm, rather than the 532 nm used in the FIGS. 6-11. FIG. 12 corresponds to FIG. 6 except that a pump wavelength of 266 nm was used in the former. As can be seen from FIGS. 6-12, the present invention is effective at various pump wavelengths. While several illustrative embodiments of tho invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art, without departing from the scope of the invention. Accordingly, it is intended that the present invention not be limited solely to the specifically described illustrative embodiments. In particular, the present invention is not limited to a pump wavelength of 532 nm or 266 nm as specifically described, but may have any pump wavelength within the ultraviolet, visible, and near infrared regions. Further, the present invention is not limited to the gaseous Raman medium which was described in exemplary embodiments, but includes any known liquid or solid Raman medium which has a polarization-dependent Raman gain. Moreover, the present invention may be used with a pulsed laser input as well as with a continuous laser input. Various modifications are contemplated and can be made without departing from the scope of the invention as defined by the appended claims.
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A Raman converter comprising an input optical pump beam (16) from a laser (18) that propagates through first and second Raman cells (12,24) and causes Stokes shifted waves (14,26) to be generated therein, and a polarizer (34) disposed between the Raman cells (12,24). The polarizer (34) is switchable during laser operation to cause the Stokes shifted waves (14) from the first Raman cell (12) to be circularly or linearly polarized, thereby causing the Stokes shifted waves (26) in the second Raman cell to be generated as rotationally shifted or vibrationally shifted waves respectively. The polarizer (34) may be switched to the selected circular or linear polarization, or may be repeatedly switched therebetween at regular or pseudo-random intervals. A second polarizer (32) may be disposed upstream of the first Raman cell (12) for selectively switching the polarization of the input pump beam (16) during laser operation. The polarizers (32) and (34) may each be used alone or in combination with each other. Combinations of rotational and vibrational Stokes shifted waves generated in the two Raman cells (12,24) provide multi-wavelength optical output signals with variable wavelength distributions.
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CROSS-RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent application Ser. No. 12/070,794, filed Feb. 21, 2008, which is incorporated herein in its entirety by reference.
FIELD
[0002] The present teachings pertain to compositions and methods for preventing corrosion and deposition within a cooling tower, and to processes for operation of evaporative cooling towers with minimal or no blowdown.
BACKGROUND
[0003] Evaporative cooling towers are the most cost effective means to provide cooling for commercial air conditioning and industrial processes. From 75% to 80% of the incoming heat load to an evaporative cooling tower is removed by evaporation of cooling water. As the cooling water evaporates, removing heat from the system, the dissolved solids present in makeup water, added to replace the evaporated water and maintain cooling water level in the cooling tower, become more concentrated. At some point, the dissolved materials exceed the solubility limit(s), commonly called the saturation point, which results in precipitation and formation of undesirable scale (usually calcium carbonate).
[0004] Blowdown is water intentionally drained from the cooling tower to restrict the buildup of dissolved solids to levels below their saturation point. Cycles is a term used to denote the concentration of dissolved solids in the system water as compared to the makeup water. For instance, two cycles indicates that the dissolved solids in the system water are twice (two times) the level in the makeup water.
[0005] Blowdown constitutes a major environmental impact from cooling tower system operation as it is “wasted” water, water run to sewers that must be replaced with fresh water. For instance, a 1000 ton rated cooling tower running at two cycles will evaporate 25,000 gallons per day (gpd) with a blowdown of 25,000 gpd. If the cycles are increased to four, the blowdown would be reduced to 12,000 gpd. Basically, evaporation equals 25.0 gpd/ton cooling (one ton cooling is defined as 12,000 btu/hr) while blowdown is calculated as evaporation/cycles−1.
[0006] Cooling towers are routinely operated at two to six cycles and are generally treated with a variety of scale, corrosion, and biological control (biocide) control chemicals. As a result, cooling tower blowdown has high dissolved solids content and often contains substantial amounts of toxic materials, primarily biocides. The high dissolved solids and biocide content of cooling tower blowdown create an adverse environmental impact when discharged to the public sewers or surface waters. In addition, environmental restrictions on discharge of some active corrosion inhibitors, such as phosphate, zinc, and molybdate, have placed restrictive limits on the amount of cooling tower blowdown that can be discharged.
[0007] A small amount of water is also lost from an operating cooling tower in the air stream passing through the unit; this is commonly termed “windage” and can vary, for example, from about 0.1% to about 0.3% of the cooling water recirculation rate. Windage limits the maximum number of cycles that can be obtained in a cooling tower as it constitutes a water loss from the system. Maximum cycles are obtained at that point where windage equals the amount of blowdown. Generally, maximum cycles are limited to values between 12 and 20. Once maximum cycles are obtained, there is no blowdown from operation of the cooling tower.
[0008] Operation at higher cycles generally results in saturation limits being exceeded. As a result, acid or scale inhibitors must be added to the water to prevent scale formation. In practice, acid is not recommended due to health, safety and control issues. The use of scale inhibiting products generally limits the system to a maximum of 150 to 200 times saturation, such as taught in U.S. Pat. No. 6,645,384, herein incorporated by reference in its entirety. In most cases, the cycles obtained by use of a scale inhibitor is far less than the maximum cycles needed to obtain no blowdown and in cases of hard, alkaline makeup waters can often be as low as 2 or 3, requiring a large blowdown discharge to maintain the system scale and deposit free.
[0009] Due to drought conditions, water pollution, and continuing increased usage of fresh water supplies, many areas of the country are experiencing water shortages. In these situations where fresh water is in short supply, it is desirable to limit, or eliminate, cooling tower blowdown to conserve as much water as possible.
[0010] The United States Green Building Council (USGBC) has implemented a building certification plan for retrofitted and new buildings, Leadership in Energy and Environmental Design (LEED). The LEED certification program awards “points” for building features that improve energy usage and reduce building operation environmental impact. Reduction, or elimination, of cooling tower blowdown can provide LEED points due to reduced water use and lessened environmental impact. The USGBC LEED program is another driver towards reduction, or elimination, of cooling tower blowdown.
[0011] Many methods have been proposed for decreasing, or eliminating, blowdown from cooling towers. In one approach described in U.S. Pat. No. 4,931,187, herein incorporated by reference in its entirety, the amount of scale causing calcium added to a cooling tower is carefully controlled, by operation of a complex system of cooling water analysis, makeup softening, and controlled hard water bypass, under computer control, to maintain the cooling water saturation below a level at which scale formation would occur. This approach is costly and has proven to be impractical in practice due to analytical and control difficulties.
[0012] Another approach, as described in U.S. Pat. No. 5,730,879, herein incorporated by reference in its entirety, is to equip the cooling tower with a bypass cation resin exchanger operated in the hydrogen (strong acid) mode with bypass of cooling water through the exchanger governed by the pH of the cooling water. The rate of bypass flow is governed by the desired pH, which is selected so as to maintain the cooling water below saturation thus preventing scale as the cycles are increased. Problems with this approach involve plugging of the resin exchanger with suspended solids typically found in cooling water and the need for constant replacement of the cation resin as its acid charge is used. An additional potential problem is that if control of the bypass flow through the acid cation resin is lost, either severe scale formation will occur or acid induced corrosion of the cooling tower structure can result. A modification is given in U.S. Pat. No. 4,532,045, herein incorporated by reference in its entirety, with the addition of a bypass filter to remove suspended solids and use of weak acid mode cation resin to reduce the possibility of severe corrosion from loss of pH control. This method still suffers from the constant replacement of the cation resin as its weak acid charge is used and from control difficulties.
[0013] In yet another bypass method, U.S. Pat. No. 7,157,008, herein incorporated by reference in its entirety, describes the use of bypass chemical precipitation of hardness causing calcium from the cooling water, thus allowing higher cycles and potential elimination of blowdown. This process involves strict chemical addition of precipitating agents to the bypass cooling water flow, removal of the formed solids, and produces a liquid sludge, containing scale causing materials, for disposal. Equipment costs are quite high with this process and process control requirements are substantial.
[0014] Another method of increasing cycles to minimize blowdown is described in U.S. Pat. No. 7,122,148, herein incorporated by reference in its entirety. This process involves softening the makeup water and increasing the cycles to a point where no blowdown would be needed. No additional products are used for corrosion control. Corrosion control is due to the buildup of silica in the water by cycling and silica precipitation is prevented by maintaining a high pH in the cooling water by either natural elevation due to cycling or by the addition of sodium hydroxide. This method does not work well in current practice as cycled softened water is extremely corrosive to most materials used to construct cooling towers, in particular steel, galvanized steel, zinc, and yellow metal alloys.
[0015] None of these methods are in current common use to increase cycles to minimize, or eliminate, blowdown from evaporative cooling towers. There is a need for compositions to control and methods to prevent, corrosion and deposition within cooling towers. There is also a need for a practical process to reduce or eliminate cooling tower blowdown.
SUMMARY
[0016] The present teachings describe a composition for controlling corrosion and deposition within a cooling tower. According to various embodiments, the composition can comprise an aqueous solution of softened water, 2-acrylamido-2-methylpropyl sulfonic acid (AMPS) acrylic terpolymer, sodium silicate, phosphate, and polyphosphate. In some embodiments, the phosphate can be in the form of phosphate ions provided from phosphoric acid or from various inorganic phosphates such as monosodium phosphate, disodium phosphate, trisodium phosphate, other inorganic phosphate salts, combinations thereof, and the like. The polyphosphate can be in the form of polyphosphate ions provided from, for example, tetrapotassium pyrophosphate, sodium metaphosphate, combinations thereof, and the like. In some embodiments, the phosphate is in the form of an orthophosphate. In some embodiments, the phosphate comprises an orthophosphate and the ratio of orthophosphate to polyphosphate, measured as phosphate ions, can be, for example, from about 0.6:1 to about 1.5:1, or from about 0.8:1 to 1.1:1, or from about 0.8:1.5 to 1:1.5, or from about 1:1 to about 1.1:1. In some embodiments, the composition can comprise at least one of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and phosphonobutane tricarboxylic acid. The composition can comprise an aqueous solution having a pH of about 12.0 or higher. In some embodiments, a composition can further comprise at least one of sodium tolytriazole, sodium mercaptobenzothiazole, zinc oxide, sodium molybdate dihydrate, sodium toluene sulfonate, sodium lauroyl sarcosinate, tetramethyl-5-decyndiol, copper phthalocyanide quad sulfonate, sodium nitrate, and combinations thereof.
[0017] According to various embodiments, a composition for controlling corrosion and deposition can be used to minimize corrosion of a cooling system to a level below generally accepted maximum corrosion rates, for example, for mild steel, yellow metal alloys, zinc and galvanized steel, and aluminum and aluminum alloys. According to various embodiments, a composition for controlling corrosion and deposition within a cooling tower can be used in a method to reduce or eliminate blowdown from evaporative cooling tower operation.
[0018] The present teachings also provide a method for preventing corrosion and deposition within a cooling tower. The method can reduce or eliminate blowdown from the operation of evaporative cooling towers. In some embodiments, a method can comprise (1) using softened water as makeup water for the cooling tower, (2) filtering the cooling water by a bypass filtration system, (3) adding to the cooling water a composition comprising an aqueous solution of AMPS acrylic terpolymer, sodium silicate, phosphate, and polyphosphate, and (4) using a biocide to control biological growth. The aqueous solution can comprise softened water. In such methods, the composition used can also comprise at least one of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and phosphonobutane tricarboxylic acid. The pH of the aqueous solution can be about 12.0 or higher, for example, 12.2 or higher, 12.4 or higher, 12.6 or higher, or from about 12.0 to about 13.0 in some embodiments.
[0019] According to various embodiments, a combination of above steps (1) through (4) can permit the cycles of an operating cooling tower to be increased to any level desired, up to and including a maximum value where windage equals blowdown and the cooling tower can operate with no blowdown.
[0020] The present teachings further provide a process for operating an evaporative cooling water system with minimal or no blowdown. According to various embodiments, the process can comprise (i) using sodium cation exchange softening of all makeup water, (ii) using bypass filtration for removal of suspended solids from the cooling water, (iii) using a composition added to the cooling water to control corrosion and deposition within the cooling water system, and (iv) using electrolytic bromine as a biocide added to the cooling water.
[0021] Additional features and advantages of the present teachings will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present teachings. It is to be understood that both the foregoing summary and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present teachings, as claimed.
DETAILED DESCRIPTION
[0022] According to various embodiments, a composition for controlling corrosion and deposition within a cooling tower can comprise an aqueous solution of 2-acrylamido-2-methylpropyl sulfonic acid (AMPS) acrylic terpolymer, sodium silicate, phosphate, and polyphosphate. In some embodiments, the phosphate can be in the form of phosphate ions provided from phosphoric acid or from various inorganic phosphates such as monosodium phosphate, disodium phosphate, trisodium phosphate, other inorganic phosphate salts, combinations thereof, and the like. The polyphosphate can be in the form of polyphosphate ions provided from, for example, tetrapotassium pyrophosphate, sodium metaphosphate, combinations thereof, and the like. In some embodiments, the phosphate is in the form of an orthophosphate. In some embodiments, the phosphate comprises an orthophosphate and the ratio of orthophosphate to polyphosphate, measured as phosphate ions, can be, for example, from about 0.6:1 to about 1.5:1, or from about 0.8:1 to 1.1:1, or from about 0.8:1.5 to 1:1.5, or from about 1:1 to about 1.1:1.
[0023] In some embodiments, the composition can further comprise at least one of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and phosphonobutane tricarboxylic acid. In some embodiments, the composition can comprise an aqueous solution having a final pH of about 12.0 or higher, for example, 12.2 or higher, 12.4 or higher, 12.6 or higher, or from about 12.0 to about 13.0 in some embodiments.
[0024] According to various embodiments, the composition can have a pH of at least 10.0. In some embodiments, a composition can have a pH of about 12.0 or higher, for example, a pH in a range of from about 12.0 to about 14.0, of from about 12.0 to about 12.5, or of from about 13.2 to about 13.8.
[0025] According to various embodiments of a composition, the AMPS acrylic terpolymer can be present in the composition in an amount of at least about 1.0% by weight, for example, in an amount in a range of from about 1.5% by weight to about 10% by weight, in an amount in a range of from about 2.0% to about 5.0% by weight, or in an amount in a range of from about 2.5% to about 3.5% by weight, based on the total weight of the composition.
[0026] According to various embodiments, sodium silicate can be present in the composition in an amount of at least 1.0% by weight, for example, in an amount in a range of from about 1.0% to about 10% by weight, in an amount in a range of from about 2.0% to about 8.0% by weight, or in an amount in a range of from about 3.5% to about 6.0% by weight, based on the total weight of the composition. In some embodiments the sodium silicate can be present in a form comprising sodium polysilicate. The sodium silicate can comprise, for example, grade 40 sodium silicate, available from the Oxy division of Occidental Chemical Corporation, of Dallas, Tex. In some embodiments, the sodium silicate can comprise or be provided in the form of an aqueous solution comprising about 9.1% by weight Na 2 O, about 29.2% by weight SiO 2 , and about 61.7% by weight H 2 O, based on the weight of the sodium silicate solution. In various embodiments, the sodium silicate can comprise an SiO 2 /Na 2 O weight ratio in a range of from about 2.0 to about 4.0, for example, from about 3.0 to about 3.5, or from about 3.2 to about 3.3. In some embodiments, additional SiO 2 can be added to a grade 40 sodium silicate solution, and then heated, or otherwise processed, to increase the stoichiometric ratio of SiO 2 to Na 2 O.
[0027] According to various embodiments, the composition can comprise phosphate ions as PO 4 , for example, provided from phosphoric acid. In some embodiments, the composition can comprise a polyphosphate ions as PO 4 , for example, provided from tetrapotassium pyrophosphate. In some embodiments, the composition can comprise a combination of phosphate ions and polyphosphate ions, for example, provided from phosphoric acid and tetrapotassium pyrophosphate. In some embodiments, the phosphate ions are provided in the form of a phosphoric acid that is made up of about 96.7% phosphate ions, and the polyphosphate ions are in the form of a tetrapotassium pyrophosphate that is made up of about 56.8% polyphosphate ions. According to various embodiments, both phosphate ions and polyphosphate ions can be present in the composition, for example, in a stoichiometric ratio of from about 1:0.7 to about 1:1.6, or within a range of from about 1:0.9 to about 1:1.3, or at a ratio of about 1:1.1. In some embodiments, the high end of the range can be from about 1.0:1.1 to about 1.0:1.6, and the lower end of the range can be from about 1:0.6 to about 1:1.1. In some embodiments, the total weight of combined phosphate ions and polyphosphate ions can be from about 1.0% by weight to about 6.0% by weight, for example, from about 5.0% by weight to about 6.0% by weight, based on the total weight of the composition.
[0028] According to various embodiments, the composition can comprise hydroxyethylidene diphosphonic acid. In some embodiments, the composition can comprise aminotrimethylene phosphonic acid. In some embodiments, the composition can comprise phosphonobutane tricarboxylic acid. In some embodiments, the composition can comprise any combination of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and phosphonobutane tricarboxylic acid.
[0029] According to various embodiments, one or more of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and phosphonobutane tricarboxylic acid can be present in the composition, each independently in an amount of, for example, up to about 1.0% by weight, up to about 3.0% by weight, or up to about 6.0% by weight, based on the total weight of the composition. In some embodiments, one or more of these is present in an amount of at least about 1.0% by weight.
[0030] According to various embodiments, the composition can comprise potassium hydroxide. In some embodiments, the composition can comprise potassium hydroxide in an amount of at least 1.0% by weight, for example, present in an amount in the range of from about 1.0% by weight to about 25.0% by weight, in a range of from about 2.0% by weight to about 20.0% by weight, or in a range of from about 4.0% by weight to about 13.0% by weight, based on the total weight of the composition. According to various embodiments, the composition can further comprise an alkaline hydroxide, such as sodium hydroxide, potassium hydroxide, a combination of sodium hydroxide and potassium hydroxide, or the like.
[0031] According to various embodiments, the composition can comprise softened water, for example, ion-exchanged softened water. As an example, sodium cation-exchanged softened water can be used. In some embodiments, the softened water can be essentially free of cations, for example aluminum, barium, calcium, iron, magnesium, and manganese ions, or contain levels of less than about 0.001% by weight of these metals. In some embodiments, the softened water can comprise a hardness level, measured as a calcium carbonate equivalent, of about 10 mg/l or lower. In some embodiments, the hardness level of the softened water can be 5 mg/l or lower, 2 mg/l or lower, 1 mg/l or lower, or 0.5 mg/l or lower.
[0032] According to various embodiments, the composition can further comprise at least one of sodium tolytriazole, sodium mercaptobenzothiazole, zinc oxide, sodium molybdate dihydrate, sodium toluene sulfonate, sodium lauroyl sarcosinate, tetramethyl-5-decyndiol, copper phthalocyanide quad sulfonate, sodium nitrate, or a combination thereof. In some embodiments, the composition can comprise sodium tolytriazole in an amount of up to about 6.0% by weight, for example, from about 2.0% to about 4.0%, sodium mercaptobenzothiazole in an amount up to about 6.0% by weight, for example, from about 2.0% to about 4.0%, zinc oxide in an amount up to about 0.2% by weight, sodium molybdate dihydrate in an amount up to about 4.0% by weight, sodium toluene sulfonate in an amount up to about 1.5% by weight, sodium lauroyl sarcosinate in an amount up to about 2.3% by weight, tetramethyl-5-decyndiol in an amount up to about 1.0% by weight, copper phthalocyanide quad sulfonate in an amount up to about 1.0% by weight, and/or sodium nitrate in an amount up to about 5.0% by weight. In some embodiments, the amounts of each of these components can independently be double the amount mentioned above, half of the amount mentioned above, or within the range of from about half to about double of each respective amount mentioned above. Each can independently be present in the composition, or absent.
[0033] According to various embodiments, the composition can further comprise one or more of sodium tolytriazole, sodium mercaptobenzothiazole, zinc oxide, sodium molybdate dihydrate, sodium toluene sulfonate, sodium lauroyl sarcosinate, tetramethyl-5-decyndiol, copper phthalocyanide quad sulfonate, and sodium nitrate, for example, each independently present in an amount of up to about 1.0% by weight, or from about 0.1% by weight to about 0.9% by weight, based on the total weight of the composition.
[0034] According to various embodiments, an exemplary composition for controlling corrosion and deposition can have the formulation shown below in Table 1. Unless indicated otherwise, all amounts, percentages, ratios, and the like, described herein, are by weight. All of the components are commercially available.
[0000]
TABLE 1
Component
CAS Number
Weight %
potassium hydroxide
1310-58-3
4.0 to 13.0
hydroxyethylidene diphosphonic acid
2809-21-4
0.0 to 3.0
aminotrimethylene phosphonic acid
6419-19-8
0.0 to 3.0
phosphonobutane tricarboxylic acid
37971-36-1
0.0 to 3.0
AMPS acrylic terpolymer
151066-66-5
2.0 to 3.5
phosphoric acid
7664-38-2
1.1 to 6.0
tetrapotassium pyrophosphate
7320-34-5
1.9 to 9.5
sodium tolytriazole
64665-57-2
0.0 to 6.0
sodium mercaptobenzothiazole
2492-26-4
0.0 to 6.0
sodium silicate
6834-92-0
3.5 to 6.0
zinc oxide
1314-13-2
0.0 to 0.2
sodium molybdate dehydrate
7631-95-0
0.0 to 4.0
sodium toluene sulfonate
12068-03-0
0.0 to 1.5
sodium lauroyl sarcosinate
137-16-6
0.0 to 2.3
tetramethyl-5-decyndiol
126-86-3
0.0 to 1.0
copper phthalocyanide quad sulfonate
0.0 to 1.0
sodium nitrate
7631-99-4
0.0 to 5.0
Balance soft water, final formulation pH above 12.0
[0035] More specific exemplary compositions for controlling corrosion and deposition can have the formulations shown below in Tables 2-4.
[0000]
TABLE 2
Component
CAS Number
Weight %
potassium hydroxide
1310-58-3
12.0
hydroxyethylidene diphosphonic acid
2809-21-4
2.5
AMPS acrylic terpolymer
151066-66-5
2.5
phosphoric acid
7664-38-2
2.0
tetrapotassium pyrophosphate
7320-34-5
2.2
sodium mercaptobenzothiazole
2492-26-4
4.0
sodium silicate
6834-92-0
3.5
zinc oxide
1314-13-2
0.2
sodium toluene sulfonate
12068-03-0
1.0
sodium lauroyl sarcosinate
137-16-6
1.0
Balance soft water, final formulation pH in range 13.2 to 13.8
[0000]
TABLE 3
Component
CAS Number
Weight %
potassium hydroxide
1310-58-3
12.0
hydroxyethylidene diphosphonic acid
2809-21-4
2.5
AMPS acrylic terpolymer
151066-66-5
2.5
phosphoric acid
7664-38-2
2.0
tetrapotassium pyrophosphate
7320-34-5
2.2
sodium mercaptobenzothiazole
2492-26-4
1.5
sodium silicate
6834-92-0
4.0
sodium molybdate dehydrate
7631-95-0
3.5
sodium toluene sulfonate
12068-03-0
1.0
sodium lauroyl sarcosinate
137-16-6
1.0
Balance soft water, final formulation pH in range 13.2 to 13.8
[0000]
TABLE 4
Component
CAS Number
Weight %
potassium hydroxide
1310-58-3
9.4
hydroxyethylidene diphosphonic acid
2809-21-4
2.5
AMPS acrylic terpolymer
151066-66-5
2.5
phosphoric acid
7664-38-2
2.0
tetrapotassium pyrophosphate
7320-34-5
2.2
sodium tolytriazole
64665-57-2
2.0
sodium silicate
6834-92-0
3.5
sodium toluene sulfonate
12068-03-0
0.4
sodium lauroyl sarcosinate
137-16-6
1.0
tetramethyl-5-decyndiol
126-86-3
0.2
copper phthalocyanide quad sulfonate
0.66
Balance soft water, final formulation pH in range 12.0 to 12.5
[0036] As can be seen, common to the formulations shown in Tables 2-4 is the presence of sodium silicate, AMPS acrylic terpolymer, phosphate from phosphoric acid, and polyphosphate from tetrapotassium pyrophosphate. According to the present teachings, phosphate and polyphosphate in the proper proportions in combination with sodium silicate can provide an excellent primary corrosion control barrier to protect various materials from accelerated corrosion. The AMPS acrylic terpolymer can control deposition on various materials and can prevent accelerated corrosion via deposit corrosion.
[0037] According to various embodiments, the formulation of the composition can be adjusted dependent upon the materials used in the cooling system construction. In some embodiments, the composition can comprise sodium nitrate when aluminum is known to be present as a material of the cooling system construction. In some embodiments, the composition can comprise sodium tolytriazole when yellow metal components are utilized, for example, brass, bronze, copper alloys, and the like. In some embodiments, a specific composition formulation can be adjusted to be used with, for example, soft steel, zinc, or galvanized steel.
[0038] According to various embodiments, in addition to sodium silicate, AMPS acrylic terpolymer, phosphoric acid, and tetrapotassium pyrophosphate, other components can be provided in the composition, for example, one or more of sodium lauroyl sarcosinate, and zinc oxide. These components can be used, for example, to increase the corrosion control ability of a composition. This effect can be additive such that the more components present the higher a degree of corrosion control that can be achieved. Of course, with more components, a higher product cost results, such that a trade-off can generally be made between cost, due to the number of components present, and the degree of corrosion control desired.
[0039] According to various embodiments, a method for preventing corrosion and deposition within a cooling tower can comprise (1) using softened water as makeup water for the cooling tower, (2) filtering the cooling water by a bypass filtration system, (3) adding to the cooling water a composition of the present teachings, and (4) using a biocide to control biological growth. In some embodiments, the composition can comprise an aqueous solution of softened water, AMPS acrylic terpolymer, sodium silicate, phosphoric acid, and tetrapotassium pyrophosphate. In some embodiments, the composition can be as described above and/or can further comprise at least one of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and phosphonobutane tricarboxylic acid. In some embodiments, the composition can comprise an aqueous solution having a pH of about 10.0 or higher, for example, of about 12.0 or higher. In some embodiments, the method can provide for increased cycles of an operating cooling tower. The cycles can be increased, for example, up to and including a maximum value whereat the loss of water through windage equals blowdown. According to various embodiments of the method, the cooling tower can be operated with no blowdown.
[0040] According to various embodiments, the softened water used in the method as makeup water for the cooling tower can comprise ion-exchanged softened water, for example, sodium cation-exchanged softened water. Sodium cation exchange softening of the makeup water can be used to totally remove or essentially remove, all cations, for example, all of aluminum, barium, calcium, iron, magnesium, and manganese ions. These cations are known to form scale in cooling towers operated at high cycles. In various embodiments, no pH adjustment or conversion of anion content of the makeup water is made. As a result, the cycled cooling water can become quite alkaline and experience an increase in pH over that of the makeup water. For example, the cooling water can reach a pH value of about 9.0 to about 9.8. At high pH and alkalinity values, the solubility of known scale-forming materials, for example, silica, substantially increases, eliminating scale formation caused by such material.
[0041] Various methods for sodium cation exchange water softening can be used, as are known to those of skill in the art.
[0042] In general, it has been determined that a practical limit to the number of cycles without a means to remove suspended solids from the cooling water is approximately six. Since much higher levels of cycles are desired, according to various embodiments, bypass filtration can be provided to remove suspended solids from the cooling water. A variety of filtration methods can be used for this task, for example backwashing media filters, using disposable cartridge filters, using hydrocyclonic filters, using membrane filters, and the like. In some embodiments, the cooling water can be filtered using a bypass filtration system at a rate of from about 5% to about 15% of the total cooling water recirculation rate. Alternatively, a bypass filtration system can provide from about 1 to about 10 cooling water system volume turnovers per day. In some embodiments, the filters utilized have a capability of removing a significant amount of suspended solids down to a size range of less than about 10 microns, for example, of less than about about two microns.
[0043] According to various embodiments, a method for preventing corrosion and deposition within a cooling tower is provided and uses a composition comprising an aqueous solution of softened water, AMPS acrylic terpolymer, sodium silicate, phosphoric acid, and tetrapotassium pyrophosphate, and at least one of hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and phosphonobutane tricarboxylic acid. The composition can be added to the cooling water. Depending on the cooling tower construction material, a specified formulation of a composition can be added. For example, in some embodiments, a composition can further comprise at least one of sodium tolytriazole, sodium mercaptobenzothiazole, zinc oxide, sodium molybdate dihydrate, sodium toluene sulfonate, sodium lauroyl sarcosinate, tetramethyl-5-decyndiol, copper phthalocyanide quad sulfonate, sodium nitrate, or a combination thereof. In some embodiments, the aqueous solution can have a pH of about 10.0 or higher, for example, a pH of about 12.0 or higher. In some embodiments, the softened water can comprise sodium cation-exchanged softened water.
[0044] Given the extreme corrosiveness of cycled softened water, the method for preventing corrosion and deposition within a cooling tower can utilize a composition of the present teachings to prevent corrosion and subsequent deposition of products of corrosion onto the cooling system materials, for example, onto the surfaces of tanks and piping within the cooling system. According to various embodiments, the method can comprise using a composition at a dosage level in a range of from about 100 mg/L to about 700 mg/L, for example, from about 200 mg/L to about 500 mg/L, or from about 250 mg/L to about 350 mg/L.
[0045] According to various embodiments, the method can provide corrosion prevention below generally accepted maximum corrosion rates of, for example, about 3 mil/yr for mild steel, about 0.5 mil/yr for yellow metal alloys, about 5 mil/yr for zinc and galvanized steel, and about 5 mil/yr for aluminum and aluminum alloys. In some embodiments, the method can reduce corrosion products deposition below corrosion rates of less than about 2 mil/yr for mild steel, less than about 0.2 mil/yr for yellow metal alloys, less than about 3 mil/yr for zinc and galvanized steel, and less than about 2 mil/yr for aluminum and aluminum alloys. In other embodiments, the method can prevent accelerated corrosion of zinc or galvanized steel that can occur at cooling water pH values in excess of 8.2, commonly referred to as “white rust”.
[0046] According to various embodiments, dosage control of the composition can be affected by manual or automatic analysis of the cooling water and subsequent manual or automatic addition of the composition. In some embodiments, dosage control can be affected by measurement of the volume of makeup water added to the cooling tower with subsequent automatic addition of a proportional amount of composition to maintain established control levels, for example, via a chemical pump. In other embodiments, dosage control can be affected by an automatic product level determination, for example, via methods, products, and processes as disclosed in U.S. patent application Ser. No. 11/700,643, filed Jan. 31, 2007, which is herein incorporated by reference in its entirety.
[0047] According to various embodiments, the method can comprise using a biocide for control of biological growth within a cooling tower and associated system. In some embodiments, the biocide can comprise bromine. In other embodiments the biocide can comprise electrolytic bromine as the sole biocide, as described, for example, in U.S. patent application Ser. No. 11/807,402, filed May 29, 2007, which is herein incorporated by reference in its entirety. In some embodiments, additional biocides can be utilized with acceptable results such as, for example, ozone, chlorine dioxide, chlorine, sodium hypochlorite, various organic biocides, hydrogen peroxide, combinations thereof, and the like.
[0048] According to various embodiments, a process for operating an evaporative cooling water system with minimal or no blowdown is provided and can comprise (i) using sodium cation exchange softening of all makeup water, (ii) using bypass filtration for removal of suspended solids from the cooling water, (iii) using a composition of the present teachings added to the cooling water to control corrosion and deposition within the cooling water system, and (iv) using electrolytic bromine as a biocide added to the cooling water.
[0049] The present teachings will be further explained with reference to the examples shown below, which are illustrative only and not intended to be limiting.
EXAMPLE 1
[0050] A specific composition formulation optimized for a cooling system to be treated was selected by considering the system construction materials and the degree of corrosion and deposition control desired. The composition had the formulation described below in Table 4, because the composition is good for use with water systems constructed of steel and yellow metal alloys, and because a high degree of corrosion and deposition control was desired. The composition was selected to give a working range of from about 250 mg/L to about 350 mg/L in the treated water, utilizing automated determination of the amount of copper phthalocyanide quad sulfonate for dose control.
[0051] The composition was dosed into a cooling tower system in which 100% of the makeup water was sodium cation-exchanged softened water softened to a maximum hardness level measured as calcium carbonate equivalent of less than about 10 mg/L in the softened water. The cooling system was equipped with a bypass media filter sized to turnover the cooling system volume about two times per day and capable of removing suspended solids down to about 2 microns in size. Biocide was added on a twice a week basis using an electrolytic bromine generator to maintain a total bromine level from about 0.5 mg/L to about 1.0 mg/L following completion of the dose.
[0052] The cooling tower was operated with no blowdown. The cycles were increased to a maximum allowed by the cooling tower windage loss, which was a function of the cooling tower construction, operating flow rate, and air flow through the unit. A maximum cycle value in a range of from about 12 to about 20 was reached, although lower and higher values were possible.
EXAMPLE 2
[0053] A study for the City of Tempe, Ariz., showed a water use reduction of 756,000 gallons per year on a 176 ton cooling tower by going from three cycles to no blowdown operation using the described process and material composition with backwashing media bypass filtration and electrolytic bromine as the biocide. This particular study was a result of a USGBC LEED certification for a new transportation center building being constructed by the City of Tempe.
[0054] Other embodiments will be apparent to those skilled in the art from consideration of the present specification and practice of the present teachings disclosed herein. It is intended that the present specification and examples be considered exemplary only.
|
A method and composition are provided for the operation of an evaporative cooling tower with minimal, or no, blowdown. In some embodiments, the method involves using sodium cation-exchanged softened water as makeup water for the cooling tower, providing a bypass filter for suspended solids removal from the cooling water, treating the cooling water with a composition for control of corrosion and deposition, and using an effective biocide for control of biological growth within the cooling tower system. In some embodiments, a composition is provided that comprises AMPS acrylic terpolymer, sodium silicate, phosphate ions, and polyphosphate ions. When dosed at the recommended levels, the composition controls corrosion of cooling system materials to generally acceptable levels in spite of the extremely corrosive environment resulting from the cycling of sodium cation-exchanged softened water in the cooling tower.
| 2
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to seismic data processing and more particularly, to wavelet extraction and deconvolution during seismic data processing.
[0003] 2. Description of the Related Art
[0004] Reflection seismology is a process which records as seismic data for analysis the reflected energy resulting from acoustic impedance changes in the earth due to the location and presence of subsurface formations or structure of interest. The reflected energy results from the transmission of short duration acoustic waves into the earth at locations of interest in a format which is known as a wavelet. The responses to the wavelet were in effect a combined product or convolution of the wavelet and the vertical reflectivity of the earth. To increase the resolution of the data and provide for enhanced ability in its interpretation, it has been common practice to subject the data to a processing technique known as deconvolution. Deconvolution involved removal of the effects of the wavelet on the recorded data.
[0005] For several reasons, the actual nature and characteristics of the actual wavelet sent into the earth were not precisely determinable. Two approaches have been used in attempt to take this into account. The first approach has been to assume that the wavelet was of an ideal form known as a zero phase or minimum phase wavelet. In seismic processing, if only seismic data exists, in order to obtain wavelet and proceed deconvolution, routinely a zero phase or minimum phase is assumed followed by inverting the wavelet and applying deconvolution. The conventional wavelet extraction and deconvolution requires zero or minimum phase assumption with two steps of procedure in frequency domain. But in fact the real wavelet is neither zero nor minimum phase.
[0006] The second approach was known as blind deconvolution, where a statistical estimate of the form of the wavelet was postulated, based on experience, field data and the like. Various forms of blind deconvolution have been proposed, one of which used what is known as the Markov Chain Monte Carlo (or MCMC) method. Recently, the MCMC method has gained attention in research to address higher order statistics features and thus obtain the wavelet with phase and reflectivity simultaneously. However, the MCMC method as a blind solution for simultaneous wavelet estimation and deconvolution has ambiguity problems, as well as other practical limitations which prevent the algorithm from being practically applied in seismic processing. The Markov Chain Monte Carlo approach appears to solve both wavelet and deconvolution at the same time. However, challenges prevent the algorithm to be practically applied to seismic industry. The first is that a maximum energy position is required, but such a position is usually unknown. Second, the extracted wavelet has possessed frequencies which were mostly out of the seismic input frequency band. Third, the deconvolution outcome resulting from trace to trace operation sometimes has broken and weakened the seismic events since multiple wavelets are extracted from multi-channel traces.
[0007] Blind deconvolution using the MCMC approach has thus been a research topic in recent years. Unlike traditional power spectrum approaches in the frequency domain done in wavelet extraction and deconvolution, the MCMC approach has treated the deconvolution processing as a problem of parameter estimation to model the reflectivity, wavelet and noise with different statics distributions by multiple sampling in the time domain. After adequate iterations of sampling, the wavelet and reflectivity series have been intended to converge to the real geological model.
[0008] The MCMC approach to blind deconvolution has, so far as is known, made certain assumptions prior to parameter estimations and then apply what is known as a Bayes approach for the implementation. The reflectivity sequence has been assumed to be random (white noise) and susceptible to being modeled statistically by what is known as a Bernoulli-Gaussian process. Another assumption has been that the wavelet can be represented by a multivariate Gaussian function. A further assumption has been that any noise present is uncorrelated, and therefore can be modeled by an independent identically distributed Gaussian function with mean zero, i.e. Inversed Gamma, distribution.
SUMMARY OF THE INVENTION
[0009] Briefly, the present invention provides a new and improved computer implemented method of processing seismic data obtained in the form of seismic traces from a reflection seismic survey of subsurface portions of the earth for analysis of subsurface features of interest, the computer implemented method comprising the steps of: forming a postulated wavelet from the seismic survey data; resolving a time of occurrence of maximum energy in the wavelet from the seismic survey data; forming a normalized amplitude of energy for the postulated wavelet from traces in the seismic survey data; forming a composite trace at the resolved time of occurrence and normalized amplitude from an ensemble of the traces in the seismic survey data; applying a time filter to the postulated wavelet based on the composite trace to form a resultant deconvolution wavelet having a main frequency in the seismic frequency band; and performing a deconvolution operation by applying the resultant deconvolution wavelet to the seismic data.
[0010] The present invention also provides a new and improved data processing system for processing seismic data obtained in the form of seismic traces from a reflection seismic survey of subsurface portions of the earth for analysis of subsurface features of interest, the data processing system comprising: a processor performing the steps of forming a postulated wavelet from the seismic survey data; resolving a time of occurrence of maximum energy in the wavelet from the seismic survey data; forming a normalized amplitude of energy for the postulated wavelet from traces in the seismic survey data; forming a composite trace at the resolved time of occurrence and normalized amplitude from an ensemble of the traces in the seismic survey data; applying a time filter to the postulated wavelet based on the composite trace to form a resultant deconvolution wavelet having a main frequency in the seismic frequency band; and performing a deconvolution operation by applying the resultant deconvolution wavelet to the seismic data.
[0011] The present invention further provides a new and improved data storage device having stored in a computer readable medium computer operable instructions for causing a data processing system to process seismic data obtained in the form of seismic traces from a reflection seismic survey of subsurface portions of the earth for analysis of subsurface features of interest, the instructions stored in the data storage device causing the data processing system to perform the following steps: forming a postulated wavelet from the seismic survey data; resolving a time of occurrence of maximum energy in the wavelet from the seismic survey data; forming a normalized amplitude of energy for the postulated wavelet from traces in the seismic survey data; forming a composite trace at the resolved time of occurrence and normalized amplitude from an ensemble of the traces in the seismic survey data; applying a time filter to the postulated wavelet based on the composite trace to form a resultant deconvolution wavelet having a main frequency in the seismic frequency band; and performing a deconvolution operation by applying the resultant deconvolution wavelet to the seismic data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a simplified functional block diagram or flow chart of a conventional sequence for processing seismic data in exploration for subsurface hydrocarbon reserves.
[0013] FIG. 2 is a functional block diagram or flow chart of a sequence of simultaneous wavelet extraction and deconvolution in the time domain according to the present invention.
[0014] FIG. 3 is a functional block diagram in more detail of a portion of the diagram of FIG. 2 .
[0015] FIG. 4 is a functional block diagram in more detail of a portion of the diagram of FIG. 2 .
[0016] FIG. 5 is a functional block diagram in more detail of a portion of the diagram of FIG. 2 .
[0017] FIG. 6 is a functional block diagram in more detail of a portion of the diagram of FIG. 2 .
[0018] FIG. 7 is a schematic diagram of a computer system for simultaneous wavelet extraction and deconvolution in the time domain according to the present invention.
[0019] FIG. 8A is a plot of a wavelet illustrating a time shift effect according to the prior art.
[0020] FIG. 8B is a plot of reflectivity based on the wavelet of FIG. 8A , also illustrating a time shift effect according to the prior art.
[0021] FIGS. 9A and 9B are plots of wavelets illustrating a scale ambiguity effect according to the prior art
[0022] FIGS. 10A , 10 B and 10 C are schematic illustrations of the effect of reflectivity sequence shift.
[0023] FIG. 11A is a plot of a comparison of an actual and a predicted wavelet obtained from processing according to the present invention.
[0024] FIG. 11B is a plot of reflectivity from an actual and a predicted wavelet obtained from processing according to the present invention.
[0025] FIGS. 12A , 12 B and 12 C are plots of seismic records illustrating effects of deconvolution on seismic data.
[0026] FIGS. 13A , 13 B, 13 C, 13 D, 13 E and 13 F are plots illustrating the effects of time domain filtering according to the present invention.
[0027] FIGS. 14A and 14B are plots of extracted wavelets from various types of seismic energy sources with and without time domain filtering according to the present invention, respectively.
[0028] FIG. 15 is a set of synthetically generated Ricker wavelets with different phase shifts in them.
[0029] FIG. 16 is a group of synthetic seismic data generated using the synthetically generated Ricker wavelets of FIG. 15 .
[0030] FIG. 17 is a set of plots of extracted wavelets based on the synthetic seismic data of FIG. 16 obtained according to the present invention.
[0031] FIG. 18A is a plot of a wavelet obtained by pre-stack wavelet extraction with conventional processing from an area where wavelet form is known based on well data.
[0032] FIG. 18B is a comparison plot of an original seismic trace and the result of convolution of the wavelet of FIG. 18A with reflectivity data from the same seismic trace.
[0033] FIG. 19A is a plot of an actual wavelet obtained from processing according to conventional processing methods.
[0034] FIG. 19B is a plot of an actual wavelet obtained from processing according to the present invention.
[0035] FIG. 19C is a plot of the power spectrum of the wavelet of FIG. 19A .
[0036] FIG. 19D is a plot of the power spectrum of the wavelet of FIG. 19B .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] In the drawings, FIG. 1 illustrates schematically a diagram of the basic general sequence S of processing data from seismic acoustic surveys to obtain images of the location of subsurface features in the earth. During a step 20 , the field recoded seismic trace data are edited and identified, and arranged into proper form for subsequent processing. The data are then subject to deconvolution processing during step 22 as has been described above. As will be set forth the present invention has developed processing techniques by which the results of the deconvolution processing of seismic data can be greatly enhanced. Step 24 involves statics correction where a bulk time shift of is applied to the trace data to compensate the effects of near surface features and anomalies in the earth, as well as for differences in topography and elevations of sources and receivers. Step 26 is velocity analysis processing to determine a seismic velocity function represent the velocity of energy travel through the earth as a function of depth. Step 28 involves moveout correction to adjust for differences in signal arrival time at different receiver positions. Step 30 is the process of stacking or summing the individual seismic trace to improve the signal-to-noise ratio of the data. Step 32 is a data filtering process to remove undesirable portions of the data for certain purposes such as improving signal-to-noise ratio, removing certain frequencies, amplitudes or other unwanted information. Step 34 is the migration process during which reflections in seismic data are moved to their correct spatial locations from those based on time measured in the recorded and processed seismic data. The migrated data are then stored in memory and displays formed for analysis and interpretations.
[0038] As has been set forth, it is important to obtain an accurate version of the seismic wavelet, and in some cases the process of blind deconvolution is used for this purpose. One such technique of blind deconvolution of seismic data is the Markov Chain Monte Carlo, also known as MCMC, simulation method.
[0039] A typical such blind deconvolution technique of Markov Chain Monte Carlo simulation with Gibbs sampling is described, for example, in “Monte Carlo Methods for Signal Processing”, IEEE Signal Processing Magazine, 2005, p. 152-169. The method described for obtaining samples according to the several assumptions mentioned above: that reflectivity is random (white noise) and susceptible to being modeled statistically by what is known as a Bernoulli-Gaussian process; that the wavelet can be represented by a multivariate Gaussian function; and any noise present is uncorrelated, and therefore can be modeled by an independent identically distributed Gaussian function of a certain type.
[0040] It is also presumed that the joint posterior distribution of a given t (trace) is known to be: P(w,r,n|t), where t is trace, r is reflectivity, w is the wavelet, and n represents noise. Accordingly, the wavelet indicating the wavelet content W, reflectivity r, and noise n can be randomly sampled from the measure P by the procedure of Gibbs sampling. The processing sequence is as follows:
[0041] Step 1: Set initial values (w 0 , r 0 , n 0 )
[0042] Step 2: Generate w 1 from P(w 0 |r 0 ,n 0 ,t), r 1 from
P(r 0 |w 1 ,n 0 ,t) and n 1 from P(n 0 |w 1 ,r 1 ,t)
[0045] Step 3: Repeat step 2 for K times until the minimum mean-square error (MMSE) calculated in step 4 is acceptably within a specified limit
[0046] Step 4: Calculate
[0000]
(
w
,
r
,
n
)
MMSE
=
1
K
J
∑
K
=
J
+
1
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(
w
k
,
r
k
,
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[0047] Normally, the first J samples that are not stationary are discarded during the calculation step as indicated. This is done to eliminate possible correlations between samples of different iterations.
[0048] The MCMC techniques described above generate non-unique wavelet and reflectivity pairs have then been convolved in an attempt to match the input seismic trace, within the estimation error. However, the derived wavelets and reflectivity series so obtained are not unique. This problem is well documented in the literature, such as in “Simultaneous Wavelet Estimation and Deconvolution of Reflection Seismic Signals”, IEEE Transactions on Geosciences and Remote Sensing, Vol. 34, No. 2, p. 377-384 (1996). The problem is based on what are known time shift and scale ambiguity problems. See FIGS. 8A and 813 , as well as FIGS. 9A and 9B for details. There are multiple pairs of wavelet and reflectivity which when convolved satisfies the seismic input. However, among these multiple pairs, only one pair is the true solution. The resultant wavelet is the shifted wavelet of the true wavelet, and the reflectivity series will be shifted inversely (in the opposite direction). Scale ambiguity behaves the same; if amplified wavelet exceeds to amplitude scale, the reflectivity scale will be de-amplified to compensate for the amplified wavelet amplitude to yield the same seismic input. The present invention reduces ambiguity of those pairs reveals a true reflectivity and wavelet pair in both position and amplitude.
[0049] A known solution to address time shift ambiguity has been to assign a maximum energy position to the wavelet. However, in most cases such a maximum energy position has been hard to determine in the data. Noisy data leads to poor extracted wavelets. Further, the short seismic time windows which have to be used do not in a number of cases satisfy the random sampling feature required in the processing technique. For these reasons, the MCMC processing results have, so far as is known, in cases proven not accurately representative of the geophysical model. Practical application and utilization of the prior art MCMC processing techniques for seismic deconvolution have not, so far as is known, been achieved.
[0050] With the present invention, a flow chart F ( FIG. 2 ) illustrates the structure of the logic of the present invention as embodied in computer program software. The flow chart F is a high-level logic flowchart which illustrates a method according to the present invention of simultaneous wavelet extraction and deconvolution in the time domain. Those skilled in the art appreciate that the flow charts illustrate the structures of computer program code elements that function according to the present invention. The invention is practiced in its essential embodiment by computer components that use the program code instructions in a form that instructs a digital data processing system D ( FIG. 7 ) to perform a sequence of processing steps corresponding to those shown in the flow chart F.
[0051] The flow chart F of FIG. 2 contains a preferred sequence of steps of a computer implemented method or process for simultaneous wavelet extraction and deconvolution in the time domain according to the present invention is illustrated schematically. The process of the present invention provides several improvements to the conventional MCMC methodology performed during the deconvolution processing such as that shown at process step 22 of FIG. 1 . The present invention utilizes the assumptions which serve as the basis for the conventional MCMC approach, but overcomes the limitations discussed above regarding the MCMC processing, as will be discussed.
Solving Time Shift Ambiguity
[0052] According to the present invention, a sampling procedure known as Metropolis-Hastings (M-H) procedure is performed during a step 40 ( FIG. 2 ) as a sampling acceptance rule in connection with the generation of the wavelet W i during the MCMC processing to solve the time shift ambiguity. Further details of the step 40 are shown in FIG. 3 . In solving the time shift ambiguity, a new sample of the wavelet parameter is formed during a step 41 based on a previous one by using a jumping distribution. If during step 42 the increased likelihood of an acceptable amplitude sample being present is determined, then the new sample is accepted during step 43 . A jumping time distribution is applied during step 44 and processing returns to step 41 for formation of a new wavelet at a time established according to the applied distribution. If the likelihood of an acceptable amplitude is determined during step 42 to be decreasing, then the new sample is accepted during step 45 , but with a probability a defined as follows:
[0000]
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?
indicates text missing or illegible when filed
[0053] The probability is a different parameter than the reflectivity previously mentioned. See FIGS. 10A , 10 B and 10 C for example illustrations of reflectivity sequence shifts. The circular shift can be illustrated by the following example: given a series data of 10 numbers: w 1 , W 2 , W 3 , w 4 , w 5 , w 6 , w 7 , w 8 , w 9 , w 10 . If circular left shift is applied, the new series will become: w 2 , w 3 , w 4 , w 5 , w 6 , w 7 , w 8 , w 9 , w 10 . If circular right shift is applied, the new series will then become w 10 , w 1 , w 2 , w 3 , w 4 , w 5 , w 6 , w 7 , w 8 , W 9 .
[0054] Processing from step 45 also returns to step 41 for formation of a new wavelet. An explanation of the theoretical details of time shift ambiguities is set forth, for example, in Labat et al., “Sparse Blind Deconvolution Accounting for Time Shift Ambiguity” IEEE International Conference on Acoustics, Speech and Signal Processing, p. 616-619, 2006.
[0055] This article describes the problem of the MCMC approach providing several possible times where an occurrence of maximum amplitude being present, which does not physically occur with an impulse wavelet in seismic data acquisition.
Amplitude Scale Shifting
[0056] The resultant estimated wavelet samples resulting from each performance step 40 are shifted and scaled versions of each other. The estimated wavelets are brought by the time shifting processing of step 50 ( FIG. 2 ) within a format compatible with what is known as the Gibbs sampling procedure. However, a direct sample average is not applicable. Normally, averaging non-correlated Gibbs samplings will yield minimum mean-squared error (MMSE) estimates, here it means: wavelet. With the present invention, an effort is made not to set a maximum energy point in the initial wavelet. Instead, a Metropolis-Hastings (M-H) procedure is applied to resolve time-shift ambiguity, the wavelet from each Gibbs sampling iteration has no-unified amplitude. Therefore direct averaging samples as a Gibbs sampling method used without amplitude scaling and shifting cannot give an approximated wavelet.
[0057] Accordingly, resealing and shifting the amplitude scale of the samples appropriately before averaging is necessary. Details of the step 50 of FIG. 2 are shown in FIG. 4 . Thus, during an initial step 51 of step 50 an optimal estimate of wavelet amplitude is specified or determined. Then, the wavelets in the data are adjusted in amplitude during step 52 to minimize the total error of the wavelet from the optimal estimate. An average of the adjusted wavelet amplitude is then formed during step 53 to update the optimal estimate average. A scaling-shifting procedure is adopted to constrain the amplitude scale of the wavelet out of wavelets from different iterations.
[0058] The Labat article cited above presents full theoretical descriptions. FIG. 8A displays various wavelets result from Gibbs Sampling with Metropolis-Hastings procedure. Those wavelets vary in amplitude scale and in phase. A scale-shifting technique applied to average those wavelets will give closest target wavelet as shown in FIG. 8B .
Super or Composite Trace
[0059] For the purposes of the present invention, it is assumed that the wavelet in a seismic record with multiple channels remains unchanged in each of the multiple channels in the record. Therefore, according to the present invention, a super trace or composite trace is combined during step 60 ( FIG. 2 ) by summing the traces of a seismic trace ensemble or grouping. Details of step 60 are set forth in FIG. 5 . During a step 61 , a trace ensemble is assembled form the entirety of traces of the survey data being processed. The seismic ensemble from which the super trace is formed may be chosen from several types of groupings, such as shot point or common depth point (CDP), or even over a specified space and time window. The assembled traces in the ensemble are then summed during step 62 . With the present invention, forming a super trace has been found to be preferable to previous techniques which extracted multiple wavelets. The advantage of the super trace according to the present invention is to conserve the energy coherence of the deconvolution image, and thus provide as an output a unique wavelet.
[0060] After the super trace is formed it is decoded to multiple traces during step 63 after extraction to recover the deconvolution image. FIG. 12A shows a raw seismic record. FIG. 12B shows the data from the seismic record of FIG. 12A after conventional blind deconvolution using a wavelet extracted from each trace in deconvolution of each trace separately. FIG. 12C illustrates the seismic record of FIG. 12A after deconvolution using a more coherent wavelet formed from treating the entire record as a super trace according to the present invention. It is apparent that significant amounts of noise evident in the record of FIG. 12B have been removed from the trace of FIG. 12C . If desired, the Beta and σ 2 distribution as well as noise control parameter γ and acceptance percentage ratio η may each be coded as adjustable according to data signal-to-noise ratio (SNR) and features in the data during step 63 . Further descriptions of features of such adjustable coding are contained, for example, in “Simultaneous Wavelet Estimation and Deconvolution of Reflection Seismic Signals” IEEE Transactions on Geosciences and Remote Sensing”, Vol. 34, No. 2, p 377-384 (1996).
Time Domain Constraint
[0061] In most cases, it has been found with the present invention not possible to achieve an acceptable wavelet even after the steps 40 and 50 are performed. This is because the output wavelet so formed may mathematically fit all parameters, but the output wavelet still occurs at frequencies out of the seismic frequency band. The results of processing which exhibit an out of seismic frequency band wavelet are clearly undesirable because various reasons might cause this inconsistency: noisy data; the geological information might not exactly satisfy the statistics assumption; a parameter used to proximate the distribution might not be optimized, and the like.
[0062] Therefore, according to the present invention, a time filter constraint is imposed during step 70 on the wavelet being formed. Further details of step 70 are shown in FIG. 6 . The time constraint is imposed during step 70 to ensure true and accurate geophysical meaning to the deconvolution processing output. A measure of the average power spectrum of the input seismic data record is formed during step 71 , and a time filter is applied to obtain the main seismic frequency from the input seismic record during step 72 . A deconvolution Ricker wavelet is then synthesized during step 73 having that determined main seismic frequency. The synthesized Ricker wavelet is then convolved in each iteration during deconvolution to ensure its frequency content.
[0063] An actual 3D post stack gather is used ( FIG. 13A ) as input for step 70 . The seismic main frequency is determined from a measure of an average power spectrum ( FIG. 13B ) of the traces of FIG. 13A to be about 20 HZ. An extracted Ricker wavelet formed from the seismic data of FIG. 13A without time domain filtering is shown in FIG. 13C , in which there can be seen to be significant noise present. Further, a power spectrum ( FIG. 13E ) can be seen to be distorted.
[0064] However, by inclusion of a Ricker wavelet, with a main frequency of 20 HZ as a time domain filter, posted into the extracted wavelet during step 70 in every iteration as discussed, a Ricker deconvolution wavelet ( FIG. 13D ) and power spectrum ( FIG. 13F ) are obtained. As can be seen, application of time domain constraints according to the present invention reproduces the wavelet and its power spectrum to a geophysically realistic form.
[0065] As illustrated in FIG. 7 , a data processing system D according to the present invention includes a computer C having a processor 80 and memory 82 coupled to the processor 90 to store operating instructions, control information and database records therein. The computer C may, if desired, be a portable digital processor, such as a personal computer in the form of a laptop computer, notebook computer or other suitable programmed or programmable digital data processing apparatus, such as a desktop computer. It should also be understood that the computer C may be a multicore processor with nodes such as those from Intel Corporation or Advanced Micro Devices (AMD), or a mainframe computer of any conventional type of suitable processing capacity such as those available from International Business Machines (IBM) of Armonk, N.Y. or other source.
[0066] The computer C has a user interface 84 and an output display 86 for displaying output data or records of processing of seismic data survey measurements performed according to the present invention for simultaneous wavelet extraction and deconvolution in the time domain. The output display 86 includes components such as a printer and an output display screen capable of providing printed output information or visible displays in the form of graphs, data sheets, graphical images, data plots and the like as output records or images.
[0067] The user interface 84 of computer C also includes a suitable user input device or input/output control unit 88 to provide a user access to control or access information and database records and operate the computer C. Data processing system D further includes a database 90 stored in computer memory, which may be internal memory 82 , or an external, networked, or non-networked memory as indicated at 92 in an associated database server 94 .
[0068] The data processing system D includes program code 96 stored in memory 82 of the computer C. The program code 96 , according to the present invention is in the form of computer operable instructions causing the data processor 80 to perform simultaneous wavelet extraction and deconvolution, as will be set forth.
[0069] It should be noted that program code 96 may be in the four of microcode, programs, routines, or symbolic computer operable languages that provide a specific set of ordered operations that control the functioning of the data processing system D and direct its operation. The instructions of program code 96 may be may be stored in memory 82 of the computer C, or on computer diskette, magnetic tape, conventional hard disk drive, electronic read-only memory, optical storage device, or other appropriate data storage device having a computer usable medium stored thereon. Program code 96 may also be contained on a data storage device such as server 94 as a computer readable medium, as shown.
[0070] The method of the present invention performed in the computer C can be implemented utilizing the computer program steps of FIG. 4 stored in memory 82 and executable by system processor 80 of computer C. The input data to processing system D are the input field seismic record and other data including, for example, wavelet length, main seismic frequency, and maximum number of iterations, etc. to run the algorithm.
[0071] FIGS. 14A and 14B illustrate examples of how the time domain filter is important to provide an acceptable output wavelet to meet seismic processing needs. FIG. 14A illustrates an extracted wavelet 100 a for an air gun source, and extracted wavelets 102 a for a vibratory source, 104 a for a dynamite source and 106 a for a combined source. FIG. 14B illustrates wavelets processed according to the present invention on which time domain constraints are imposed for the same sources: a wavelet 100 b for an air gun source, and wavelets 102 b for a vibratory source, 104 b for a dynamite source and 106 b for a combined source. As can be seen, the wavelets of FIG. 14B are more representative of actual wavelets than those of FIG. 14A .
Synthetic Test Data Experiments
[0072] The processing techniques of the present invention were investigated on synthetic data. A time invariant random number generator was introduced for sampling. A sparse reflectivity sequence was generated by Gaussian distribution with accept probability of 0.03, with 0.05 variance of additive Gaussian noise.
[0073] Four Ricker wavelets ( FIG. 15 ) each with a main frequency of 30 Hz were produced with different phase: a wavelet 112 with phase of 0°, a wavelet 114 with phase of 45°, a wavelet 116 with a phase of 90° and a wavelet 118 with phase of 120°. The four wavelets were used to convolve with sparse random reflectivity to generate the synthetic data plotted in FIG. 16 . By supplying the synthetics as input, four corresponding wavelets ( FIG. 17 ) were then obtained. The extracted 0° phase wavelet 112 and the extracted 120° phase wavelet 118 , respectively, can be seen to match their original form wavelet exactly. The wavelets 112 and 118 extracted for the 90° degree and 120° wavelets each has a polarity reversal (180° phase difference) from its original form; reflectivity and wavelet cannot be differentiated for polarity reversal. In a word, two pairs of wavelets appear to meet the parameter fittings. One pair is a 180° polarity reversal of the other pair, as is evident from FIG. 17 . However, this should not hinder any practical utilization for the purposes of either deconvolution or processing quality control.
Actual Field Seismic Data Example
[0074] The processing techniques of the present invention were also applied to a set of pre-stack data. A shot record from an actual survey was chosen, which was pre-processed through basic seismic processing flow with sample rate of 2 ms. Thirteen traces were combined together to form a super trace, which was used as input. A wavelet length of 50 samples was specified with 2000 cycles of iteration. The object function η is 0.90, with noise control parameter Gamma supplied equal to 1.0. The results are shown in FIGS. 18A and 18B FIG. 18A is the extracted wavelet. It appears sound in a geophysical context and appears to have a form of a zero phase wavelet, though no comparison result was performable. The simulation result listed in FIG. 18B indicates the error between the original input seismic trace and convolved seismic trace is so small that for practical purposes it is ignorable.
[0075] In addition, an angle-stack CDP-order 3D post stack section was used as the model. The field seismic data was tested by currently available (Jason's Geophysical) software, in comparison with that of the present invention. The time window of 1000˜2500 ms and 15 traces from cross-line CDP were included. The parameters for processing according to the present invention were: an assigned wavelet length of 100 ms; noise parameter of Gamma 2, the acceptance η of 0.95, and the number of iteration cycles was 4000. An extracted wavelet ( FIG. 19B ) and associated power spectrum ( FIG. 19D ) were compared with a wavelet ( FIG. 19A ) and power spectrum ( FIG. 19C ) obtained from Jason's Geophysical software as to wavelet shape and power spectrum. The phase of the wavelet in FIG. 19B differs very slightly from zero phase, but the wavelet is very close in both shape and amplitude spectrum to that of FIG. 19 A. The power spectrum in FIG. 19D of the wavelet of FIG. 19B is not as smooth as the amplitude spectrum in FIG. 19C . However, this is as a result of the use of a totally different estimation principles with the present invention illustrated. The data in the FIG. 19C wavelet was estimated from both seismic and well log data as input where reflectivity is extracted from well log data thus making the extraction more precisely determinable. The present invention obtains two unknowns: wavelet and reflectivity from the seismic data alone without well log data.
[0076] Also, the statistical inversion naturally contains some vibratory energy different from traditional approaches. Again, this should not affect deconvolution or process quality control.
[0077] From the foregoing, it can be seen that with the present invention, it is feasible to apply a time domain approach to extract a mixed phase wavelet and obtain a deconvolution image simultaneously without requiring well log information. The present invention when applied in conjunction with the MCMC methodology appears to remedy both the wavelet time shift and scale ambiguity problems typically seen in known blind deconvolution techniques.
[0078] A time filter constructed from a seismic major frequency offers another layer of geophysical constraint to the output wavelet. The super or composite trace formed according to the present invention and utilized in data preparation improves the deconvolution image resolution and coherency.
[0079] The present invention when implemented in conjunction with MCMC processing has been found to address the issues associated with blind deconvolution according to the prior art. The present invention modifies the MCMC sampling step to solve MCMC's inherent time shift ambiguity and uses a unified energy coefficient and averaging of wavelets to solve scale ambiguity. The present invention also reduces dependency on input data for deconvolution and provides a good wavelet in theory as synthetic test confirms.
[0080] The invention has been sufficiently described so that a person with average knowledge in the matter may reproduce and obtain the results mentioned in the invention herein Nonetheless, any skilled person in the field of technique, subject of the invention herein, may carry out modifications not described in the request herein, to apply these modifications to a determined structure, or in the manufacturing process of the same, requires the claimed matter in the following claims; such structures shall be covered within the scope of the invention.
[0081] It should be noted and understood that there can be improvements and modifications made of the present invention described in detail above without departing from the spirit or scope of the invention as set forth in the accompanying claims.
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Blind wavelet extraction and de-convolution is performed on seismic data to enable its practical usage in seismic processing and to provide quality control of data obtained in areas where data from wells are not available. The wavelet extraction and deconvolution are realized in the time domain by iteration, producing a mixed phase wavelet with minimal prior knowledge of the actual nature of the wavelet. As a result of the processing, the de-convolved seismic reflectivity is obtained simultaneously.
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RELATED APPLICATIONS
[0001] This application is related to U.S. patent application Ser. No. 11/612,613, filed Dec. 19, 2006, and entitled “System and Method for Generating Hydrogen Gas.”
FIELD OF THE INVENTION
[0002] The field of the present invention is mechanical fluid turbine systems, including turbines for capturing wind energy using a mechanical catching, concentration, and energy extraction system. More particularly, the present invention relates to harvesting of renewable sources of environmentally available kinetic and radiation energy employing low wind, wind, small stream hydroelectric, and wave action. Accompanying driving principles of energy generation include concentration, channeling, energy source chaos reduction, internal capture and control, and a Venturi system to enhance captured energy flow from the system. The organized systems and methods produce leverage to generate electricity employing one or more rotary generation,
[0003] Background of the Invention
[0004] The availability of inexpensive supplies of carbon-based fuels enabled the United States to develop a dynamic and vibrant national economy through most of the twentieth century. Today, even though U.S. sources of high-quality fossil fuel feedstocks are mostly exhausted, 85 percent of U.S. energy comes from fossil fuels. To meet the demand for these fuels, the United States imports more and more fuel. Today 61 percent of our petroleum and 17 percent of our natural gas are imported.
[0005] The current trend to high prices of petroleum and natural gas is not likely to change, as reserves are limited and demand is increasing. Known reserves of petroleum and natural gas are projected to last no more than 25 years and 45 years, respectively, if consumed at the rate projected for a growing global economy (Source: U.S. Energy Information Administration (EIA) 2007 http://www.eia.doe.gov). Others (President Obama's speech Mar. 29, 2012 in Las Vegas) indicate that there is fewer than 100 years of oil reserves available in the United States along with Newt Gingrich, candidate for President, saying on March 15, 2012 that there are in ground reserves for 125 years of natural gas. One hundred years of society is not a very long time. In view of certain recent increased supplies of natural gas in the United States increasing its use to generate energy only increases the CO2 and other pollutants put into the atmosphere and the lands we all use. Employing more efficient renewables and sustainable energy technologies such as described here provides an improved environment. Thus, it is evident that there is a tremendous need for on-site generated renewable energy harvested from environmental sources such as is described in the unobvious and novel designs in this patent.
[0006] Electrical generation by wind has been primarily carried out by large utilities and/or companies setting up large wind turbines in usually remote high wind mountain areas. The major electricity generation methods used today are based on consuming coal, oil, or natural gas to fire large steam turbines. Often long transmission lines are required over great distance and at high cost and loss of energy. Hoover Dam is an example of a hydroelectric energy source that is located a long distance from major populations. Nuclear plants are generally located some distance from the uses and require long distance transmission power lines to transport the electricity to users and are subject to decommissioning, dismantling, and low-level waste disposal problems.
[0007] The need for low wind electric generators is evident, wherein nearly all large wind bladed, 8′ and larger, generators do not start turning until approximately 18 mile per hour wind comes up (#4 on the Beaufort Code). The design of the present low wind generators are expected to begin turning on the Beaufort Code, at #2 which is 4-7 miles per hour, or 6-11 kilometers per hour and which is described as a light breeze where leaves rustle, wind can be felt, and wind vanes move. Many places in the United States have regular low wind such as ocean shores, lake shores, and low lying foot hills. Where the vast majority of people reside there is often low wind rather than high wind that is required by supper sized wind generators. An example is seen where 20 miles inland from the ocean shore the daily weather report on air speed is usually 5 to 10 miles per hour wind.
[0008] Nearly all wind turbines at the utility level and the smaller individual type employ three rotating blades or there are certain methods using rotating towers and/or vertical circular shapes that may not be acceptable by property covenant in some commercial, industrial, and residential areas. However, no practical way is known to generate electricity on-site where the energy is need, exclusively from the available renewable environmental energy sources, for individual and commercial needs, employing typically available low wind, employing no open turning blades or high obtrusive towers with vertical rotation. The present invention is planned for application in populated areas where code and public acceptance in urban, rural, and remote locations where there is prohibition of obtrusive noisy rotating large or small propeller blades. In some cases those open rotating blades may even be restricted by local codes and building ordinances.
[0009] The National Laboratory at ARCO Idaho made a nationwide study of the small streams in the United States. There are many more such streams than a casual review might identify and people have a great preference to locate their residence and vacation homes on these streams and have an accompanying need for electricity. In August 2010 the Natural Resources Water and Power Subcommittee of the U.S. House of Representatives introduced the Small-Scale Hydropower Enhancement Act (H.R. 5922) to promote efforts to produce more hydropower from smaller sources. Often utility electricity is not available in many of these locations; therefore the need for on-site small stream electricity has wide-spread appeal. These government actions help establish the need and economic growth possibilities for an invention such as is proposed here.
DESCRIPTION OF THE PRIOR ART
[0010] Gagnon, U.S. patent application No. 61/245,461, does attempt to use a funneling effect, but still employs propeller blades that cannot take advantage of the increased air flow. The air is actually directed off the blades by the convex shape and rounded edges of the traditional propeller blades, reducing the power effect of the incoming wind. This system does not include a venturi effect for exiting air.
[0011] Lodewyk, U.S. Pat. No. 4,045,144, shows a wind concentrator. However it is a very open system not allowing for any building of the pressure of the incoming air.
[0012] U.S. Pat. No. 6,887,031 shows concentration through a series of circular fan blades, one set of blades feeding the air to the next, but it is also a very open system with convex propeller blades and no funneling effect of incoming air, nor any means to keep the incoming air in the path of the blades.
[0013] T. J. van der Horn, U.S. Pat. No. 6,713,893, uses two fan blades rotating in opposite directions. The blades are typical convex design with little ability to catch wind and with the opposite direction rotation very likely reduces generation capability in low wind.
[0014] Tocher, U.S. Pat. No. 6,887,031, uses concentrator wings that reportedly draw wind into the front of centralized concentric wings providing wind to the turbine impeller blades that are smaller than popular designs. The impeller blades are propeller shape with a convex and rounded edge design that allows the air to easily slide off the blade, rather than pushing on them.
[0015] Vertical axis wind turbines show no concentration or wind capturing devices while they may include concave shapes, but are open on the sides and ends, which allow sloughing off of the air moving. Attey, U.S. patent application Ser. No. 12/478,597, proposes catching wind interior to a vertical axis rotation, but the catchers are rounded and there is no way to keep the air interior, and the air can slip off the arms, because there are only three where space is open between the rounded sections. There is nothing to keep the air interior to the vertical unit.
SUMMARY
[0016] An efficient turbine is disclosed for converting kinetic fluid energy into a usable form, such as electricity. The turbine generation system has a turbine within a casing, with box-like catchers positioned in the turbine to efficiently capture the fluid, extract its energy, and direct the fluid to an exhaust. A compressive intake and channelizers cooperate to concentrate and direct the fluid into the boxes. A second compressive intake is also connected with the exhaust, and includes a Venturi structure that increases the velocity of the exhaust fluid, thereby assisting in the efficient exhausting of the fluid from the turbine or concentration and pressurized boxes of the present system.
[0017] There is a widespread movement and interest by individuals, commercial, and government and military preference for renewable environmentally harvested energy in view of the energy raw materials shortages and high prices for user and for utility energy throughout the country. The present disclosure provides a distinct combination and application of three aspects of environmentally available kinetic and radiation energy. An aspect of the present invention provides widespread environmentally available low wind harvesting generator system employing a case with unique collectors, concentrators, fluid pressure capturing boxes, and a rotating shaft connected to an electrical turbine generator. Attached to the shaft are a series of members that catch incoming environmental fluid kinetic energy and concentrate and channel that captured energy to drive and rotate the shaft to turn an electrical turbine. A weatherized case is provided to handle environmental fluid flow conditions for harvesting the natural energy sources available.
[0018] A major aspect of one embodiment the present invention provides a kinetic energy flow capturing turbine generator system with an exterior funnel that directs, concentrates, and channelizes the in-coming random air movement into the case. This acts to pressurize the available energy that is focused, funneled, and channelized into the unique square boxes that capture the uniquely funneled and channelized environmental energy, which boxes are attached to the drive shaft and consequently to the electrical turbine in the electrical generating engine. This capturing and directing system overcomes the usual random, wobbling, and slipping of fluid flows that nature generally provides on rotating propeller blades. Incoming flows from nature are always mixed, random, and flocculating and they twist, turn, and shift in the forceful movements they have. Very seldom will wind, stream, or steam flows present a flat front face against any obstacle.
[0019] An important novel feature of this application is the Venturi air system that draws the kinetic energy flow out of the case, so used energy in the boxes will not block the incoming pressure of the fresh incoming fluid. This basic Venturi system provides fluid flow to the turbine generator system in which the concentrated and channelized energy flow enters and passes through the case with a Venturi as part of the energy exit system providing an increase in flow or a drawing of the flow by means of a lower pressure area acting to pull the fluid stream out of the case. This Venturi construction of a section of the flow exit system has large concentrating openings at the beginning of the case ends with a constricted section of the Venturi in the middle creating suction and/or vacuum for pulling the exiting flow and thus providing additional pull on the kinetic energy loaded box system attached to the drive shaft of the electrical turbine.
[0020] This renewable energy harvesting and storage system is designed to capture widely available natural fluid energy sources including low wind, and small stream hydro. By capturing these natural and renewable energy sources in this novel system these energy sources can be converted to electrical energy and employed to generate storable hydrogen, an energy carrier, which can then be used as needed in fuel cells for electricity, for heating and cooling in commercial, industrial and government and military applications as well as for fueling automobiles and other transportation engines.
[0021] A major aspect of one embodiment of the present invention provides a kinetic energy turbine generator system that has box-like attachments on the arms of the rotating shaft to keep the kinetic energy that moves into the box-like attachments so the moving energy is captured and changed from a chaotic movement to controlled energy in the smaller individual boxes, rather than being able to freely move from side to side or up and down. This system of closely attached boxes open on the outer face and individually constitute a square with a flat bottom with sides higher than the base width. This system of boxes with open faces, when facing the channelized rectangle opening of the fluid intake, will fill the entire opening as the individual sets of boxes rotate on the central shaft. This feature keeps the wind and fluid pressure in the box-like catchers, rather than allowing the moving fluid to fall off, to mix, spread, and weaken as air can do on all traditional fan blades, thus keeping the energy pressure in the boxes attached to the arms of the rotating system. The box-like wind catcher attachments provide greater pressure to the rotation wheel arms and consequently on the drive shaft rather than those employing traditional propeller convex blades or even rounded-bottom cup-like attachments. Without the square wind catching boxes on the arms, incoming energy can flow and mix with other chaotic movement, which thus has a less forceful push on the arms and drive shaft and on into the electrical turbine. In order to drive the natural forces with even more pressure upon the drive shaft and the electrical turbine the box catchers may also be treated with textured coatings containing both small and medium sized particles (1 or 2 cm up to 5 cm or as appropriate considering the box size) on the interior walls of the boxes.
[0022] An additional aspect of one embodiment of the present invention provides a wind turbine generator system designed to harvest low wind in the 2 to 15 mile per hour wind speed compared to other competing 8 to 12 foot and larger bladed turbines that do not start turning until 15 to 18 MPH or higher wind. To operate with low wind this novel and unobvious systems of wind concentration, channelizing, and unique box-like designs with accompanying Venturi suction of exiting air, all help to keep control of the available chaotic wind and other fluid flows rather than have such flatten out on convex propeller blades and disappear in unwanted directions. A shroud is also included to contain the air where it is wanted with exit ports to allow it to be sucked out in the proper place in the Venturi fluid movement cycle. There is also a transmission or gear system to match the wind velocity with the electrical turbine to take advantage of low wind in many locations where people live and work.
[0023] The intake boxes on the arms of the drive shaft are attached directionally to produce a starting motion from even very low intake kinetic fluid movement. This attachment of the boxes provides direction and starting leverage to the boxes, where without this there could be a non-directional push on the boxes.
[0024] It is anticipated that this energy system can be constructed with moderately low cost materials that are readily available. The case can be sheet metal or thermoformed of plastic sheets; the wind catcher boxes can be assembled out of plastic or metal sheets or inexpensively thermoformed of plastic. The front concentrator set may be made of metal or plastic, as can the fluid exit Venturi.
[0025] A major embodiment of the present invention is an energy exit Venturi, which construction, creates a higher pressure and a low velocity prior to the exiting air intake ports followed by a physically smaller air flow area that functions to create a lower pressure than in the front section of the Venturi with an accompanying higher exit air flow out the exit port yielding a suction process drawing exiting air from the fluid turbine case, because of the lower pressure in that section of the Venturi. This reduces possible back pressure on the box-like energy catchers on the rotating shaft and is designed to add vacuum suction that will pull on the box-like wind catchers, increasing turning pressure on the shaft. This fluid moving process operates on Daniel Bernoulli's principle which states that, where the velocity is high, pressure is low, and where the velocity is low, the pressure is high, increasing air movement in the channel.
[0026] This Venturi system draws on the pressurized flow being released from the boxes on the arms of the shaft at an approximate position of half way around inside the case. At this position the Venturi principal activates to suck air out of the boxes and the case passageway and thus is removing any drag that would otherwise be on the loaded push on the catcher boxes. This will increase pressure on the arms of the rotating shaft.
[0027] The Venturi system is powered by an opening on the front of the case allowing kinetic flow to pass from the front to the rear of the case, and making a drawing effect on the air in the case to get air out of the case, increasing the continual fluid stream through the case. This Venturi system has flanges extending outside the case to gather and harvest additional kinetic energy and pressurize it into the Venturi opening, thus to increase the overall Venturi effect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a side view cut-away diagram of the low wind turbine generation system and method in accordance with the present invention.
[0029] FIG. 2 is a front view cut-away of the low wind turbine generation system and method in accordance with the present invention.
[0030] FIG. 3 is a perspective view of the low wind electrical generating system and method in accordance with the present invention.
[0031] FIG. 4 a is a front view of propeller blades for a low wind generator in accordance with the present invention. Each blade of the propeller is illustrated with attached wind catching boxes.
[0032] FIG. 4 b is a side view of a low wind generator in accordance with the present invention.
[0033] FIG. 4 c is a side view of an individual catching box for attachment to a propeller blade of a low wind generator in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Referring to FIG. 1 and FIG. 2 , a case 1 houses a turbine with rotating box 4 units attached to a shaft 5 , the box units 4 accepting environmental fluid kinetic energy in the form of wind at intake 2 to activate gears and a transmission 15 to drive an electric generator 17 for generating electricity employing the kinetic energy of the wind. The new system is able to perform particularly effectively in relatively low wind conditions as compared to larger open bladed wind turbines with the traditional three large extended blades or other vertical designs and compared to fin based small hydroelectric generators. This electrical generation system has a kinetic energy intake 2 , including extended flanges 3 , that increase the open face wind collection area of the case, and consequently gathers more kinetic energy that is concentrated, directed, and funneled into the channelizing squares 25 ; thereby increasing the usable energy to drive the electrical turbine 17 and generate electricity.
[0035] The case 1 positions a shaft 5 extending across the case that carries the box fluid catchers 4 that are attached to separating disks and by connecting arms 8 to the shaft 5 . The shaft drives the wind power to the gear box 16 and transmission 15 that controls and drives the electrical generating turbine 17 . Although shown generally as rectangular blocks, it will be appreciated that the fluid catching boxes may take other geometric shapes 4 . Further, the boxes 4 are illustrated being wider at the top and narrower at the bottom to facilitate orientation around the shaft 5 . It will be understood that other shapes may be used.
[0036] In FIG. 1 there is a fixed shroud or housing 6 that circles part of the turning wind catchers 4 and arms 8 of the shaft. This shroud is placed to keep flow pressure in the area of the wind catcher boxes 4 . Catcher boxes may have a texture coating inside 27 . In addition there is an exit port 7 out of the shroud and Venturi case to provide exit flow 13 by the suction of the Venturi to aid in drawing the used energy out of the case.
[0037] FIG. 1 and FIG. 2 disclose the Venturi system 11 . The Venturi 11 has a system of extending structures 9 built in that creates the Venturi effect. The Venturi flow intake 10 in the front of the case is exposed to the incoming wind, has flanges 3 to collect and concentrate additional flow over the amount of air flow the exact shape of the Venturi case would gather. In the first section of the Venturi 11 , at the structures 9 , the velocity is lowered and the pressure is higher than the incoming flow as compared to the intake 10 . In the exit side 13 of the Venturi the velocity of the flow movement is higher and pressure is lower. This causes a lower pressure area that assists in pulling the exhaust wind out of the Venturi case 11 and exit through the exit 13 .
[0038] In FIG. 2 the forward facing extended flanges 3 are visible on all four sides of the entrance space 2 for funneling and concentrating the incoming environmental energy. These flanges 3 are in place to capture and harvest increased amounts of kinetic energy over what would enter the case without the extended flanges. In FIG. 2 note that a screen 14 is in place over the entire structure to prevent birds and other objects from entering the case. On the side of the case 1 is transmission case 15 that may include gear driven 16 ratio, both or either of which are in place to manage the power that is in the drive shaft 5 that drives the electrical generating turbine 17 in order to derive electricity from the available power of the incoming and processed kinetic energy. The case has a base system 20 for stabilizing the case to a foundation whether it is in an elevated position on a stand, a roof, or attached at ground level. In FIG. 2 there is a swivel system 21 and orientation apparatus 22 (in FIG. 1 ) to maintain the case 1 in a position for constant facing into the environmental energy source with accompanying brake 23 and air flow system 24 (in FIG. 1 ) that protects the case from possible damaging high winds. FIG. 3 . shows a perspective view of the generator described with reference to FIG. 1 and FIG. 2 . FIG. 3 . does not illustrate the intake channelizers 25 ( FIG. 1 ) to assist in understanding the relationship between the channelizers and the other turbine structures. One skilled in the art will readily recognize that the channelizers will extend across the entire opening. It will also be appreciated that other structures may be used to direct the driving wind from the concentrator portion through the channelizers to the wind-catching boxes. FIG. 3 also has a cut-away portion on the lower exhaust path that shows the Venturi structure discussed with reference to FIGS. 1 and 2 . It will be understood that other shapes and placements for the Venturi structure may be used consistent with this disclosure. FIG. 3 shows the series of receiver boxes 4 facing out to receive incoming wind flow that are attached to the shaft 5 .
[0039] In FIGS. 1 , 2 , & 3 one skilled in the art can visualize and understand that although the drawing depicts principles, device, and machines that lend themselves to the fluid flow processing wind the same principles apply to flowing water, and steam that can pass through the system making electricity with the same noted flow compression technologies and the same Venturi forces to help deplete and make the boxes ready for new income flows of the several fluids that flow through the electric generator.
[0040] The disclosed renewable energy system provides a method and system to provide concentrated, and channelized multiple sources from the available powerful environmental energy flows for application to fulfill human energy needs for residential, commercial, industry, government, and defense department that reduces the demand for fossil fuel such as wood, coal, oil, natural gas, biofuels, nuclear, and utility electricity, the latter of which mostly comes from fossil fuel. Harvesting available environmental energy of localized low wind and available small stream hydro energy, through concentration and channelizing to make electricity also provides opportunity to fill energy needs such as cooking, heating, air conditioning, furnaces, kilns, vehicles, etc. To take further advantage of this renewable energy method and system also provides the opportunity to produce clean hydrogen by splitting water with this source of electrical energy without the burden of fossil fuels and their expense of electrolyzers and disadvantages of deep well drilling and oil importing from the several foreign hostile nations. Hydrogen is clean and renewable and from the present application can be used to address all of the above noted human energy needs.
[0041] In accordance with the present disclosure, the fluid flow is managed by concentration, channeling, and small box containment to drive an electrical generating turbine using directed openings. There is an accompanying intake for a fluid flow powered Venturi opening with pressurized flow exit to aid in suction and pull on exiting flows through the system. Employment of the Venturi principle in this patent is novel and unobvious, separating this application from all other low flow wind and small stream patents.
[0042] There is an axle positioned in the enclosure with a set of members extending radially. A plurality of flow catching boxes are attached to the respective radial members. Major features of this application are the flow concentrators and channeling positioned to harvest stream flows through the opening that is positioned in such a manner that the concentrated flow is secondarily concentrated and is directed into the flow catching boxes. The funneling and concentration system on the front of the case provides 6 to 10 times the flow kinetic pressure into the enclosure as compared to no concentration and no channeling that other wind and small hydro generators offer.
[0043] In this scenario of incoming flow of low wind and small stream flow, all of which appear in random and chaotic conditions are captured and controlled and not allowed to act randomly or move around in the box-type wind catchers as compared to the slipping, sliding, and rolling off as on all other types of blades, propellers, and fans with their convex rounded surfaces. The multiple box catchers are open to all incoming concentrated flow, rather than operating as traditional three propeller or fan bladed generators. A gear and transmission system with accompanying computerized control is included to provide additive adjustments for varying flow speeds for turning the turbine.
[0044] [45] These combined designs including the leveraging of concentration and channeling with Venturi suction applied in low flow wind generators and small stream hydroelectric systems make it more feasible to harvest these lower energy values from renewable sources for on-site, remote, rural, and/or urban renewable electricity. This otherwise un-captured energy is useful for a wide range of energy markets in many clean energy applications such as general purpose electricity as well as for battery charging, hydrogen production, for residential, industrial, telecommunications, commercial, government, and defense department use.
[0045] FIG. 4 illustrates another embodiment of the present invention. FIG. 4 c has an electrical generating turbine 66 that has fan blades 61 that extend radially from the generator 66 . The illustrated generator 66 has 3 blades, but more or fewer may be used. In use, the generator 66 is typically mounted on a pole or other elevated structure. The design and implementation of an electrical wind generator is well known, so will not be described in detail.
[0046] Advantageously, a set of capture boxes 64 are attached to each fan balde 61 to assist in the capture and conversion of wind 60 into electrical energy. As illustrated, the boxes 64 protrude above the surface of the blade 61 , but it will be appreciated that the boxes may be integrally formed into the blade 61 itself. In one case, the externally projecting boxes would be useful for a retrofit application where the capture boxes 64 are attached to fans blades that are already built or installed.
[0047] Referring now to FIG. 4 b , each capture box 64 has a concentrator 63 that captures and concentrates wind into the main cavity 65 of the capture box 64 . The incoming air passes through the concentrator 63 , into the main cavity 65 , and exists through a cavity exit port 7 . Each capture box 64 also has a lower channel 66 that accepts wind through a second concentrator flange 63 . The wind received into the lower channel 66 passes through the Venturi structure 9 , which causes a lower pressure area adjacent to the exit 13 . This lower pressure area at the exit port 13 acts to draw air more efficiently from the main cavity 65 and out the exit port 13 . Accordingly, more of the wind's energy may be captured and converted to electrical energy by the use of the Venture-aided capture boxes 64 . It will be appreciated that the boxes may take many different shapes, sizes, placement, and density consistent with this disclosure. It will also be appreciated that the interior of the boxes many be coated or textured to enhance wind capture or to reduce friction.
[0048] While particular preferred and alternative embodiments of the present intention have been disclosed, it will be appreciated that many various modifications and extensions of the above described technology may be implemented using the teaching of this invention. All such modifications and extensions are intended to be included within the true spirit and scope of the appended claims.
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Briefly, an efficient turbine is disclosed for converting kinetic fluid energy into a usable form, such as electricity. The turbine generation system has a turbine within a casing, with box-like catchers positioned in the turbine to efficiently capture the fluid, such as wind, and extract its energy, and direct the fluid to an exhaust. A compressive intake and channelizers cooperate to concentrate and direct the fluid into the boxes.
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PRIORITY STATEMENT
This is a Continuation-In-Part of U.S. application Ser. No. 12/925,359 filed on Oct. 20, 2010, now U.S. Pat. No. 9,161,554, which is a Continuation of U.S. application Ser. No. 11/706,123 filed Feb. 14, 2007 (which issued as U.S. Pat. No. 7,851,210 on Dec. 14, 2010), which is a Continuation-In-Part of U.S. application Ser. No. 10/607,691 filed Jun. 30, 2003 (which issued as U.S. Pat. No. 7,226,778 on Jun. 5, 2007), the entire contents of each application and patent being incorporated herein by reference.
BACKGROUND
1. Field
Example embodiments relate, in general, to apparatuses and processes for naturally recycling protein waste into feed and, more specifically, to apparatuses and processes for enzymatically digesting, emulsifying and drying protein waste including feathers for use in animal feed.
2. Description of the Related Art
A mass of waste is accumulated on a regular basis in such operations as poultry production facilities. Protein waste such as carcasses from animal production facilities pose problems for disposal. For example, such problems include odor and generation of bacteria in building. Carcasses are currently disposed of in many ways including land filling and burning. Natural gas production from waste materials is also known in the art and such processes typically also result in a byproduct which is used as animal feed or fertilizer. Some facilities process the protein waste to produce a component for animal feed but these plants often are not designed to provide a mostly closed system and, consequently, air, moisture, and other contaminants may enter creating an environment where microorganisms can multiply and destroy the quality or usefulness of the processed protein waste.
And, although there may be processing plants at which protein waste may be disposed and recycled, there is not an efficient way to remove the waste from the site to the processing plant in such time and condition as necessary for efficient processing. The timing of such disposal is essential to managing toxicity and odors yet it is not feasible for each animal production plant to also operate a processing plant for its protein waste.
Animal feed requires a protein component. In addition to the carcasses which can be processed for protein recovery, feathers are inexpensive and also high in protein, however, feathers are difficult for animals to digest. And, although there are processes known for forming feather meal, often these processes require steam which, if too hot, will denature the proteins in the feathers and reduce their nutritional values. It is also known that certain bacterial strains produce keritinase which is an enzyme capable of degrading feathers and that, properly employed, such degradation can result in material that can be used in animal feeds. See U.S. Pat. Nos. 4,908,220; 4,959,311.
In addition, it is known in the art to provide a means to grind swine or poultry waste and then mix it with ingredients that will facilitate fermentation of the protein waste. See U.S. Pat. No. 5,713,788. The invention disclosed therein provides a specific grinding mechanism which includes a grinding drum with a helical groove on its outer surface in which a length of chainsaw chain, teeth side out, is positioned. This invention does not include a way to re-circulate and thoroughly mix the ground protein and catalyst but, instead, depends on a metered application of catalyst to the ground protein waste as it moves past the grinder wherein the metering of the catalyst is triggered by the load on the grinder. This is deficient in that no additional mixing of the ground protein waste and catalyst is contemplated such that there is substantial risk that it will not be appropriately mixed and the catalytic action will be hampered.
What is needed is a way for the animal production facilities to efficiently and timely dispose of animal waste in such a way that is non-toxic and odor free. In addition, the system has to be affordable for the animal production facilities and the resultant recycled product must be usable. Preferably, a mostly closed system should be used to eliminate environmental contaminants and to provide avenues for recycling by-products. Finally, for any disposal of feathered animals, the system must provide a method of breaking down not only softer protein sources, but also feathers and in a manner that does not denature or destroy the food value of the proteins.
Example embodiments provide a system wherein animal protein waste is processed in such a way that a portion of the system may be mobile and can be taken from one animal production facility to another or simply positioned at one facility until it reaches capacity.
Example embodiments also provide a protein processing system which is capable of degrading feathers without destroying their food value.
Example embodiments also provide a way for many different and maybe distant animal production facilities to have routine access to a processing facility.
Example embodiments also provide a means for recycling and breaking down the animal protein wastes and to recycle by-products of the process.
Example embodiments also provide an apparatus with mixing and grinding capabilities associated with one another in a manner that results in a mostly closed system which may be an efficient process for digesting, emulsifying and drying the recycled protein waste while also providing a means for recycling other byproducts such as water and for minimizing growth of damaging micro organisms. Example embodiments also provide an apparatus for recycling animal protein that produces fuel from the digesting or fermentation of animal protein waste.
Example embodiments also provide an apparatus for animal protein recycling that produces fuel and uses the produced fuel to power portions of the apparatus.
SUMMARY
Example embodiments provide an apparatus and process for naturally recycling poultry carcasses or parts thereof for use as a nutritional supplement. The apparatus may have four modules: (1) a pH adjustable enzymatic digest medium mixing assembly, (2) a mobile grinding assembly which may be mounted on a truck trailer; (3) a digesting and emulsifying assembly which may include a heated tank and separator or alternatively a fermentation assembly; and (4) a drying system.
The enzymatic digest medium of example embodiments may include protease/keritinase, inedible egg or a waste fluid that includes protein with or without fat, water as needed, and a preservative. The amount of preservative to be added to the medium may be determined by a circuit using data from a load sensor on the grinding means to control a variable frequency drive which may control the speed of a preservative pump. The digest medium mixing assembly may be equipped with a pH probe and monitor which may trigger the addition of an acidic solution as needed to adjust a pH of the enzymatic digest.
The mobile grinding assembly may be moved from one animal production facility to another or may remain at one facility. The mobile grinding assembly of example embodiments may be mounted on a trailer and may include a holding tank for the enzymatic digest medium and a conveyor for loading carcasses into a grinder. The remainder of the grinding assembly may be a closed system. Once through the grinder, the ground carcasses or portions or parts thereof may be pumped into a storage tank with the enzymatic digest medium to produce a protein solubles mixture. This mixture may then be recirculated through a chopper pump for a few minutes to further reduce particle size of the ground protein waste and assure adequate mixing of the digest and the proteins and then pumped into a tanker truck for transport. Multiple batches of the protein solubles mixture may be generated so that the storage tanks may be filled and emptied as many times as necessary until all the waste has been disposed. Then, the mobile grinding assembly can be moved to another location or it can simply remain until it is needed again.
The protein solubles mixture created by the mobile grinding assembly may then be moved to a centralized and stationary processing plant and transferred from the tanker truck to the digesting and emulsifying assembly. An enzyme digest of the present invention in the protein solubles mixture may work best between about 100 and 130 degrees Fahrenheit while other enzyme digests disclosed work best under 125 degrees Fahrenheit. Therefore, the digesting and emulsifying assembly may heat the mixture if needed and only periodically recirculate it until the enzymatic digest has altered the protein solubles to a mostly liquid state. For embodiments that include digestion of parts that include fats, or for enzyme digest mediums that include fat content, it may be preferred to emulsify the digested protein solubles to completely disperse the fats and proteins. The digested and emulsified proteins may then pumped into a separator tank and the bottom layer of water may be drained off periodically, leaving the emulsified proteins. The water layer may then recycled back to the portion of the system where the enzymatic digest is made. The remaining emulsified proteins may then be transferred to the drying system.
In example embodiments, fats may be collected from the digest and emulsification assembly via a closeable connection and a first fats tank. Fats may be separated from the protein solubles mixture by addition of acid from an acid tank via a pump. A valve on the recirculation means may close to allow transfer of fats from the digest tank through an open closeable connection. Fats in the first fats tank may be separated from water in a centrifuge and stored in a second fats tank. The water collected may be recycled back into the digester tank.
In alternative to the digest and emulsification assembly, the apparatus may include a fermentation assembly. In the fermentation assembly the protein solubles mixture is broken-down by bacteria which produces gas. Gas may be collected by a piping and compressed by a compressor into a pressure tank. Check valves along the piping prevent backflow of gas. The compressor may be controlled by a pressure sensor on the fermentation tank.
The dryer system may use a carrier for surface absorption of moisture, extrusion, air flow, and heat to accomplish the removal of moisture. A carrier such as cereal, soybean meal, corn or wheat mids may be fed through a volumetric feeder to a mill where it may be finely ground to provide ample surface area for absorption. The carrier may then be conveyed to a mixer where it may be mixed with the emulsified proteins until a doughlike consistency is reached. At this point, the dough is fed into an extruder to remove additional moisture and to extrude dough pellet-like pieces which may then moved by oscillating belt to the drying apparatus.
The drying apparatus may include a dryer bed which, in example embodiments, may be a conveyor belt enclosed in a housing. The housing may alternate air flow direction and have heat zones for removing yet more moisture content and a cooling zone to return the pellet-like pieces to near room temperature. The pellet-like pieces may then be moved progressively through the air flow, the heat zones and the cooling zone by the conveyor. In example embodiments, the pellet-like pieces may be sized and then run over a vibrating screen to separate the non-uniform sized pieces. Finally, the appropriately and uniformly sized pellet-like pieces may be packaged.
Other objects, features, and advantages of example embodiments will be readily appreciated from the following description. The description makes reference to the accompanying drawings, which are provided for illustration of example embodiments. However, example embodiments do not represent the full scope of the invention. The subject matter which the inventor does regard as his invention is particularly pointed out and distinctly claimed in the claims at the conclusion of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a mobile grinding assembly portion in accordance with example embodiments;
FIG. 2 is a diagram showing an enzymatic digest mixing assembly portion in accordance with example embodiments;
FIG. 3 is a side view of a mobile grinding assembly portion in accordance with example embodiments;
FIG. 4 is an enlarged plan view of the mobile grinding assembly of FIG. 3 ;
FIG. 5 is a side view of a digesting and emulsifying assembly portion in accordance with example embodiments;
FIG. 6 is a side view of a fermentation assembly portion in accordance with example embodiments;
FIG. 7 is a block diagram showing the components of a dough mixing apparatus and an extruder of a drying system portion in accordance with example embodiments;
FIG. 8 is a block diagram of a drying apparatus of the drying system portion in accordance with example embodiments;
FIG. 9 is a flow diagram showing the steps for the process for natural recycling of protein waste in accordance with example embodiments;
FIG. 10 is a diagram showing an enzymatic digest mixing assembly portion in accordance with example embodiments; and
FIG. 11 is a plan view of a mixing device and a grinding assembly in accordance with example embodiments.
DETAILED DESCRIPTION
Example embodiments provide an apparatus and process usable for, amongst other things, naturally recycling protein waste. In example embodiments, the apparatus and process for naturally recycling protein waste may include an enzymatic digest mixing assembly shown generally as 15 in FIG. 2 , a mobile grinding assembly shown generally as 40 in FIGS. 3 and 4 , a digesting and emulsifying assembly shown generally as 100 in FIG. 5 or a fermentation assembly shown generally as 200 in FIG. 6 , and a drying system shown generally as 126 in FIGS. 7 and 8 . These components may all be present on a movable platform or separated; for example, the mobile grinding assembly may be movable while the enzymatic digest mixing assembly is stationary.
In example embodiments, the process, as is shown in the flow chart depicted in FIG. 9 , may include an enzymatic digest medium 12 of a particular pH level that may be prepared and stored until such time as it is needed. The enzymatic digest medium 12 of example embodiments may include enzymes 14 , inedible egg 16 , a preservative 18 , and water. The enzymes 14 may include protease to break down and digest most proteins, and keritinase to aid in digestion of feathers. The preservative 18 may restrict multiplication of bacteria or microorganisms which could adversely affect the end product. Although inedible egg is a logical choice when the process is used in conjunction with poultry production, other fluid wastes such as outdated ice cream, molasses, milk by products, and others that include proteins, fat, and water or proteins without fat such as blood could be appropriately substituted.
In example embodiments, a pH of the enzymatic digest medium 12 may be adjusted by a measured addition of an acid. One such acid may be phosphoric acid, to maintain a level of pH 5 or within the range of about 4-6 or 4-8. Using phosphoric acid to effect a change in pH include the added benefit of adding phosphorous to the medium and, in turn, provides a high phosphorous product which may enhance the desirability of the additive for animal feed. Other acidic solutions may also be used. For example, lactic acid is one such reasonable alternative. In the case where lactic acid is used, the fermentation process which occurs as a natural consequence of the use of lactic acid, (in addition to digestion by enzymes) also acts to break down the protein waste and lowers the pH at the same time.
In example embodiments, protein waste 216 , which may be in the form of spent hens or some portions thereof, may be ground and the enzymatic digest medium 12 and ground protein waste 216 may be thoroughly mixed and re-circulated through a chopper pump 88 to produce a protein solubles mixture 84 . The protein solubles mixture 84 may be maintained at or heated to a temperature optimal for enzyme digestive action which may range between about 90 degrees Fahrenheit and about 125 degrees Fahrenheit and may be recirculated periodically until the mixture is mostly liquid. The heat created by the exothermic digestive process and the friction of recirculation in certain conditions may be enough to maintain the optimal temperature and, if not, additional heat may be provided. For example, the mixture may be recirculated for 1 hour every 12 hours for 3-4 days, however, the speed of the process may be increased if additional enzyme is used. Further, the speed is effected by the nature and content of the protein solubles mixture and may be dramatically shortened. For example, in one embodiment, digestion may be complete in as little as about 30 minutes to about 1½ hours. In example embodiments, the protein solubles mixture 84 may be strained and when the number of quills remaining in the strainer is acceptable, the digestion is complete. In example embodiments, the protein solubles mixture 84 may be emulsified to disperse fats and proteins and the protein solubles mixture 84 may be allowed to separate. A resulting water layer 125 may be drained off and recycled to be re-used for mixing enzymatic digest medium 12 and the emulsified proteins 121 may be mixed with a carrier 132 . In example embodiments, the resulting water layer 125 may be drained several times before the emulsified proteins 121 are mixed with a carrier 132 .
In example embodiments the carrier 132 may be delivered to a high speed mixer 140 by volumetric feeder 130 . The carrier 132 may comprise a relatively high surface area to volume ratio which acts to absorb some of the moisture. Upon mixing with the emulsified proteins 121 , a doughlike mixture is produced. The doughlike mixture may then be extruded into a plurality of pellet-like pieces 146 and the pellet-like pieces may be passed through a drying apparatus 126 which may use air flow, multiple heat zones, and at least one cooling zone for further removal of moisture. The pellet-like pieces may be finally sized through a mill 166 to a uniform, granular size. In example embodiments the mill 166 may be a hammer mill. The off-size pellet-like pieces may be removed and the remaining uniform, granular pellet-like pieces may be packaged. An apparatus usable to accomplish the foregoing process is described below.
An example of an enzymatic digest mixing assembly 15 is shown in FIG. 2 . In example embodiments, the enzymatic digest mixing assembly 15 may be used to mix enzymes 14 , inedible egg 16 , and a preservative 18 with water to form an enzymatic digest medium 12 of a given, predetermined, preset, or optimal pH level. The enzymatic digest mixing assembly 15 may include at least one enzymatic digest mixing tank 22 , pumping means 24 , a re-circulating assembly 26 , and means for adjusting the pH level of the enzymatic digest medium 12 which, in example embodiments, may be a pH adjustment assembly 28 . The pumping means 24 of example embodiments may comprise a first centrifugal pump and the re-circulating assembly 26 may comprises a first inductor nozzle 27 associated with the pumping means 24 and a return pipe 29 for circulating the enzymatic digest medium 12 . In example embodiments, the enzymatic digest mixing assembly 15 may further include load cells 25 associated with a digital scale 25 a and positioned such that addition of the enzymes 14 , preservatives 18 , and inedible egg 16 can be measured. It is also contemplated that, in addition to external measuring of the ingredients, other internal measurement options such ultrasound and light beams may be used to monitor the amounts of each ingredient as it is added.
The pH adjustment assembly 28 of example embodiments may include a pH probe 30 , a pH monitor 32 , and a first positive displacement pump 34 all electrically associated, and a supply of acidic solution 36 fluidly connected to the positive displacement pump 34 and to the enzymatic digest mixing tank 22 through a check valve 38 . The first positive displacement pump 34 of example embodiments may include a variable speed motor. In example embodiments, the variable speed motor may be configured to pump 1-10 gallons per minute. In example embodiments, the enzymatic digest medium 12 may be formed and or placed in the mixing tank 22 and recirculated while a pH of the enzymatic digest medium 12 is monitored by the pH monitor 32 . For example, the enzymatic digest medium 12 may be recirculated for at least 3-5 minutes while the pH probe 30 provides a pH level to the pH monitor 32 . In example embodiments, the pH monitor 32 may compare the pH level with an optimal, preset, predetermined, or given level and send a signal to the positive displacement pump 34 to move the acidic solution 36 into the mixing tank 22 where recirculation continues. The re-circulating assembly 26 may continue to mix the enzymatic digest medium 12 , the pH probe 30 may again measure the pH level, and the monitor 32 may compare the level to the optimal, preset, predetermined, or given level, and again determine whether acidic solution 36 should be added to the mixing tank 22 . When the pH level reaches the optimal, preset, predetermined, or given level, the enzymatic digest medium 12 is ready to be used or stored.
A particular example of the enzymatic digest medium 12 includes, per ton, about 2½ pounds of protease and keritinase 14 , about 2 pounds of preservative 18 , and the remaining pounds inedible egg 16 and water. In this example, the pH was lowered to about 5 by addition of phosphoric acid 36 . This pH level is optimal for this particular enzymatic digest medium, however a range from about 4-6 may be effective and the amount of enzyme may be altered according to the speed of digestion desired and the enzymes used.
In example embodiments, once the enzymatic digest medium 12 has been prepared, it can either be stored or it can be moved via a transporting device 37 , such as a tanker truck, to the mobile grinding assembly 40 where it may be mixed with ground protein waste 216 . Referring now to FIGS. 3 and 4 , the mobile grinding assembly 40 comprises a movable platform 42 which may include a front portion 43 , a mid portion 44 and a rear portion 45 , a conveyor belt 56 for moving protein waste, a holding tank 58 in which the enzymatic digest medium 12 is stored, at least one prep tank 60 , 62 , and a pump 64 to move the enzymatic digest medium 12 from the holding tank 58 to the at least one prep tank 60 , 62 , in example embodiments, the movable platform 42 may be a semi trailer. The mobile grinding assembly 40 may further comprise a grinding means 66 which may include a grinder inlet 67 positioned near the conveyor belt 56 , a grinder plate 68 , a grinder outlet 69 , and at least one grinder knife 70 , wherein the grinder outlet 69 is positioned such that output from the grinder outlet 69 may flow by closed connection 71 into a hydro pump 82 the hydro pump 82 having a lower outlet 74 . A specific non-limiting example of the grinding means 66 is a Weiler Meat Grinder utilizing a 7/16″ plate. However, different plate combinations may be used such as double-cut, double-knife combinations with a ¾″ or ⅜″ plate in this situation, one knife may be positioned on the inside of the grinder plate 68 and another on the outside of the grinder plate 68 .
The grinding assembly 40 may further comprise a mixing means 80 which, in example embodiments, may comprise at least one second positive displacement pump 72 , which may be fluidly connected to the at least one prep tank 60 , 62 and to the hydro pump 82 of the grinding means 66 such that the enzymatic digest medium 12 can be moved to the hydro pump 82 where output from the grinder outlet 69 is mixed with the enzymatic digest medium 12 to form a protein solubles mixture 84 . The enzymatic digest medium 12 may be pumped against the grinder outlet 69 and may wash ground protein waste down into the hydro pump 82 . The lower outlet 74 of the hydro pump 82 is fluidly connected to a centrifugal chopper pump 88 which is further associated with the at least one prep tank 60 or 62 and a recirculation piping system 92 including an inductor nozzle 90 . This arrangement provides a way to move the protein solubles mixture 84 through the chopper pump 88 and into the prep tank 60 via the inductor nozzle 90 which may be positioned to generate a circular flow in the prep tank 60 . The mixture 84 may be continually recirculated through the chopper pump 88 until it is of desired consistency and thoroughly mixed. This may require several minutes.
The protein solubles mixture 84 may then transported to the digesting and emulsifying assembly 100 , an example of which is shown in FIG. 5 , either via pumping it directly or by pumping it first to a tanker truck 94 and then to the assembly 100 . The mobile grinding assembly 40 may be a closed system wherein the grinder inlet 67 is the only input open to the environment.
Where more than one prep tank 60 , 62 is present, one prep tank 60 may be recirculated or unloaded while another is being filled and recirculated. In this example embodiment, a separate chopper pump may be associated with each prep tank.
In example embodiments, the front portion 43 of the movable platform 42 may be occupied by a power source 75 , for example, a generator, the mid portion 44 of the movable platform 42 may be occupied by the holding tank 58 and prep tanks 60 , 62 , and the rear portion 45 may be occupied by the grinding means 66 . The conveyor belt 56 may be associated with or occupy the rear portion 45 . In example embodiments, the at least one prep tank 60 , 62 may be a cone-bottomed tank.
The apparatus of example embodiments may further include an electronic load sensor 96 , a programmable logical computer circuit 97 , a variable frequency drive 98 , and a preservatives pump 99 to deliver preservative 18 to the enzymatic digest medium 12 . The load sensor 96 may be located on the grinding means 66 to sense a load of the grinding means 66 . The variable frequency drive 98 controls the preservatives pump 99 . The load sensor 96 and variable frequency drive 98 may be connected to the programmable logical computer circuit 97 . The programmable logical computer circuit 97 may be programmed with a program to determine the amount of preservative to pump based on a load.
In example embodiments, a relationship may be established between the amperage load on the grinding means 66 and the desired revolutions per minute to run the preservatives pump 99 . The following program is usable in example embodiments:
Grinder Amp
Load
Preservative Pump RPM
40 amps
no load
0
RPM
50 amps
25% load
437
RPM
60 amps
50% load
875
RPM
70 amps
75% load
1300
RPM
80 amps
Full load
1800
RPM
The digesting and emulsifying assembly 100 of example embodiments may be stationary or mobile or some portions may be mobile, while others are stationary. A non-limiting example of the digesting and emulsifying assembly 100 is shown in FIGS. 5 and 6 . As shown in FIGS. 5 and 6 , the digesting and emulsifying assembly 100 may include a digester tank 101 for digesting the protein solubles mixture 84 , a means 102 for heating the mixture 84 , a means 103 for recirculating the mixture 84 for periodic mixing, a means 107 for collecting fats from the digester tank 101 , and an emulsifier 105 . In example embodiments, the means 103 for recirculating the mixture 84 may include a centrifugal pump 104 . The emulsifier 105 may be fluidly connected to a pump 106 , the digester tank 101 , and a separator tank 108 .
In example embodiments, the digester tank 101 may be a non-pressure tank with a cone bottom 109 enclosed within a housing 110 . The heating means 102 of example embodiments may include a heating element 111 and water (not shown) enclosed in the housing 110 . The housing 110 of example embodiments may be a vented water jacket. The heating element 111 of example embodiments may heat the water in the housing to about 120° F. and in turn may warm the protein solubles mixture 84 from about 90° F. to about 110° F. The protein solubles mixtures 84 may be recirculated while it digests. In certain conditions friction from circulation and the exothermic digestion may provide heat sufficient to maintain the digest medium at an optimal temperature and reduce or negate the need for additional heat.
The fat collection means 107 of example embodiments may include an acid storage tank 112 , a positive displacement pump 113 , the centrifugal pump 104 , a first fats storage tank 117 , a centrifuge 118 , and a second fats storage tank 119 . After digestion of the protein solubles mixture 84 in the digest tank 101 , the fat (not shown) may be separated from the protein solubles 84 by recirculating the protein solubles 84 with acid (not shown). In example embodiments, acid may be stored in the acid storage tank 112 and pumped into recirculation means 103 by the positive displacement pump 113 while the protein solubles 84 are recirculated. Alternatively, the acid could be pumped solely by the centrifugal pump 104 . A pH probe 114 in the digest tank 101 may control the pump 113 and/or the centrifugal pump 104 to stop the pumps at a desired pH level.
Because acid may be introduced into the protein solubles 84 , the pH of the protein solubles 84 may drop causing fat (not shown) to settle out of the digest tank 101 . The settled fat may be pumped out of the digester tank 101 using the centrifugal pump 104 . The recirculation means 103 includes a recirculation valve 115 and a closable connection 116 connecting the digest tank 101 to the first fat storage tank 117 . During recirculation, the recirculation valve 115 is open and the closeable connection 116 is closed. During collection of fat the recirculation valve 115 is closed and the closeable connection 116 is open. In example embodiments the centrifugal pump 104 may stop pumping fat when all of the fat in the digester tank 101 has been removed as confirmed by visual operation.
The centrifuge 118 may be fluidly connected to the first storage tank 117 and the second fat storage tank 119 . The centrifuge 118 may act to pump the fat from the first storage tank 117 and separate water from fat. The separated water (not shown) may be recirculated back into the protein solubles mixture 84 and water may be recycled in example embodiments. Separated fats may be stored in the second storage tank 119 . The stored fats may be used as a fuel source for the drying system 120 or for other purposes.
After digestion and removal of fat, the protein soluble mixture 84 may be pumped into the emulsifier 105 for further removal of fats. Emulsification produces emulsified proteins 121 which may be transferred to a separator tank 108 . The separator tank 108 may have a closeable opening 123 in fluid connection with the enzymatic digest mixing tank 22 . A water layer 125 may form in the separator tank 108 and the water layer 125 may be drained for use in mixing additional digest medium 12 .
Referring to FIGS. 7 and 8 , the emulsified proteins 121 may be moved to the drying system 120 which may include a dough mixing apparatus 122 , an extruder 124 and a drying apparatus 126 . An example of the dough mixing apparatus 122 is shown in FIG. 7 . As shown in FIG. 7 , the dough mixing apparatus 122 may comprise a volumetric feeder 130 for measuring an absorbing carrier 132 which may be mixed with the emulsified proteins 121 . In example embodiments, the dough mixing apparatus 122 may be positioned over a mill 134 for finely grinding the absorbing carrier 132 . The mill 134 may, for example, be a high speed hammer mill or disc mill. The dough mixing apparatus may further include a second conveyor belt 136 which may move the absorbing carrier 132 from the mill 134 to a high speed continuous mixer 140 . A third positive displacement pump 142 may be associated with the separator tank 108 and may move the emulsified proteins 121 to the high speed mixer 140 where it may be mixed with the absorbing carrier 132 to produce a doughlike mixture. In example embodiments, the absorbing carrier 132 may be a substance with characteristics like wheat mids, soybean meal, corn, or a previously dried material made for such purpose and the third positive displacement pump 142 may be of the variable speed variety.
In example embodiments, the doughlike mixture may be moved to the extruder 124 which may pressure-force moisture out and produce a plurality of pellet-like pieces 146 . In example embodiments the pellet-like pieces may have a thickness of about 3/16″ and of random length. The pellet-like pieces 146 may be extruded onto an oscillating belt 148 which may distribute the pellet-like pieces 146 evenly and connect the extruder 124 to the drying apparatus 126 . Additional moisture may be removed by the drying apparatus 126 using heat and air movement. An example of the drying apparatus 126 , as shown best in FIG. 8 , may comprise a dryer bed 150 positioned to receive the pellet-like pieces 146 from the oscillating belt 148 , a housing 152 through which a dryer bed conveyor belt 154 may move and convey the pellet-like pieces 146 and which may include at least one heating zone 156 , 158 , 160 , at least one cooling zone 162 , and means to direct airflow 164 . The mill 166 may receive the pellet-like pieces 146 after they emerge from the housing 152 and size the plurality of pellet-like pieces 146 to a uniform size. A vibrating screen 170 may be used to remove any of the plurality of the pellet-like pieces 146 which are of a non-uniform size. In example embodiments, the means to direct airflow 164 may comprise fans positioned to alternate the flow of air to provide uniformity in drying. In example embodiments, the heat zones 156 , 158 , 160 may provide temperatures of 300, 275, and 250 Fahrenheit, in this order, such that the maximum temperature of the plurality of pellet-like pieces does not exceed 250 Fahrenheit. If the heat of the pellet-like pieces 146 exceeds this level their taste may be too bitter and the amino acids may be degraded. The cool zone 162 may return the pellet-like pieces 146 to within about 10 degrees of ambient temperature. Vents may return the heated air from the cool zone 162 to the heat zones.
The protein solubles mixture 84 may alternatively be digested through fermentation. In this example embodiment, the pH of the enzymatic digest medium 12 may be adjusted using lactic acid. The fermentation itself replaces the enzymatic digest and a fermentation assembly 200 replaces the digest and emulsification assembly 100 . The fermentation assembly 200 may include a non-vented low pressure tank 202 , a means 264 for recirculating protein solubles 84 , and a means 206 for collecting gas.
In example embodiments, the fermentation tank 202 may have a means 208 for heating the mixture 84 comprising a cone bottom 210 surrounded by a housing 212 filled with water (not shown) and heated by a heating element 214 . The heated water in turn heats the protein solubles mixture 84 and microorganisms (not shown) within the tank 202 . The microorganisms in the tank 202 may be bacteria that produce methane gas. In example embodiments, the recirculation means 264 may include a centrifugal pump 216 that may recirculate the contents of the tank 202 . In example embodiments, the gas collection means 206 may comprise piping 218 in fluid connection with the tank 202 , a compressor 220 , and a pressure tank 222 . During recirculation, the bacteria may produce gas (not shown) and may increase pressure in the tank 202 . In example embodiments, the tank 202 may include a pressure sensor 224 to monitor pressure in the tank 202 . At the appropriate pressure, the pressure sensor 224 may activate the compressor 220 which may compress the gas for storage in the pressure tank 222 . As a safety measure, the pressure tank 222 may include a pressure guage 226 . To prevent backflow of gas, the piping 218 may include check valves 228 located before and after the compressor 220 . The stored methane gas may be used as a fuel source for the dryer system 120 or for other purposes. After digestion and collection of gas, the protein soluble mixture 84 may be pumped into the emulsifier 105 for further removal of fats consistent with the earlier described example digest and emulsification assembly 100 .
Example embodiments provide a process to treat animal byproducts or only portions of animal carcasses. For example, some embodiments provide a method to treat blood and feathers which are waste products of a poultry processing plant, and to treat this mixture on site at least to the degree necessary to avoid bacterial contamination and reduce other negative effects of a rendering plant. The method reduces or minimizes problems associated with odor and bacteria, such as salmonella and E. coli . Embodiments also provide a method of treating byproducts in a manner that is sanitary. The various embodiments will provide a product that is a high protein material. One use of the high protein material is as an additive to existing animal foods and/or as a new ingredient for animal foods. For example, the high protein material may be added to a feed additive.
In example embodiments, blood and feathers, and optionally offal, necks, backs and/or wings, may be collected on site of a rendering plant or a slaughter plant. These products may be collected into stationary or mobile tanks. In example embodiments, the blood may be combined with enzymes and preservatives to form an enzymatic digest medium; the enzymatic digest medium, in turn, may be combined with the feathers, and optionally offal and/or other parts remaining. Preferably the feathers are ground prior to addition to the enzymatic digest medium which will decrease the time necessary to achieve the degree of digestion required. The enzymes in the enzymatic digest medium will liquefy substantially all of the feathers (and offal, if present) and the progress of the digestion can be monitored by checking the level of quills remaining. Once the number of quills or quill parts is at the desired level, the digestion process may be allowed to end by removing the heat supply, or adjusting the pH or by other known means. The digested mixture may be stored for a relatively long period of time. It may be used in its liquid state or dried using heat, and thereafter milled in the presence of cereal that operates as a carrier or combined with another material prior to or during drying.
Where offal is included in the digest medium, or added to the digest medium at a later time, fat will be present. The fat may be separated as described herein, and the remaining portion be emulsified, with drying of the material to follow.
In example embodiments, the processes may occur in a mobile or a stationary system. The digest equipment may include a tank for producing the digest medium and another tank for the actual digestion process. The second tank may be equipped with a means to stir the enzymatic digest and the animal byproducts and a means to pump the material out when finished. The first and second tanks may be configured with a heating system to heat the mixture of the animal byproducts and the enzymatic digest medium while the mixture is mixing.
FIG. 10 is a view of an enzymatic digest mixing assembly 15 ′ in accordance with example embodiments. In example embodiments, the enzymatic digest mixing assembly 15 ′ of FIG. 10 is similar to the example enzymatic digest mixing assembly 15 of FIG. 2 . For example, as shown in FIG. 10 , the enzymatic digest mixing assembly 15 ′ may include an enzymatic digest tank 22 ′ which may be configured to receive a preservative 18 ′, at least one enzyme 14 ′, an organic material 16 ′, and water. In example embodiments, the preservative 18 ′, the at least one enzyme 14 ′, the organic material 16 ′, and the water may be mixed in the enzymatic digest tank 22 ′ to form an enzyme digest medium 12 ′. In example embodiments, a moisture content of the enzyme digest medium 12 ′ may be about 65% or greater to render the enzyme digest medium 12 ′ usable for digesting animal byproducts (for example, feathers, to be explained later).
In example embodiments the organic material 16 ′ may be blood, for example, avian blood such as chicken or turkey blood. The at least one enzyme 14 ′ may be a protease, a lipase, a keratinase, an amylase, or a combination thereof. Thus, the at least one enzyme 14 ′ may be capable of breaking down proteins or fats that may be present in the enzyme digest medium 12 ′ or proteins or fats that may be combined with the enzyme digest medium 12 ′. For example, the enzymatic digest medium 12 ′ may be combined with feathers either during the production of the enzymatic digest medium 12 ′ or added to the enzymatic digest medium 12 ′ at a later time.
In example embodiments, the preservative 18 ′ may be a preservative or an agent that prevents or reduces microbial growth. For example, non-limiting examples of the preservative 18 ′ are sodium bisulfate, meta-bisulfate, a reducing agent, potassium sorbate, sodium sulfate, phosphoric acid, and hydrochloric acid. The proper selection of a preservative or a combination of preservatives depends on the materials to be digested and the enzyme digest itself. In example embodiments, the enzyme digest medium 12 ′ may be stably stored for a long period of time due to the presence of a preservative 18 ′. For example, the enzymatic digest medium 12 ′ may be stored for several months prior to its use.
In example embodiments, the enzymatic digest mixing tank 22 ′ may be further configured to receive a pH controlling medium 36 ′. In example embodiments, the pH controlling medium 36 ′ may be a basic medium or an acidic medium. For example, non-limiting examples of the pH controlling medium 36 ′ may be sodium hydroxide or phosphoric acid. The addition of the pH controlling medium 36 ′ may be helpful in regulating a pH of the enzyme digest medium 12 ′. In example embodiments, the pH controlling medium 36 ′ may be added to the enzymatic digest mixing tank 22 ′ by a pH adjustment assembly 28 ′ which may be comprised of a pump 34 ′, a pH monitor 32 ′, and a pH probe 30 ′. In example embodiments, the pH probe 30 ′ may be exposed on an inside of the enzymatic digest tank 22 ′ and thus may be exposed to the enzymatic digest medium 22 ′.
In example embodiments, the pH probe 30 ′, the pH monitor 32 ′, and the first positive displacement pump 34 ′ may be electrically associated, and a supply of pH controlling medium 36 ′ may be fluidly connected to the positive displacement pump 34 ′ and to the enzymatic digest mixing tank 22 ′ through a check valve 38 ′.
The first positive displacement pump 34 ′ of example embodiments may include a variable speed motor. In example embodiments, the variable speed motor may be configured to pump 1-10 gallons per minute. In example embodiments, the enzymatic digest medium 12 ′ may be formed or placed in the mixing tank 22 ′ and recirculated while a pH of the enzymatic digest medium 12 ′ is monitored by the pH monitor 32 ′. For example, the enzymatic digest medium 12 ′ may be recirculated for at least 3-5 minutes while the pH probe 30 ′ provides a pH level to the pH monitor 32 ′. In example embodiments, the pH monitor 32 ′ may compare the pH level of the enzymatic digest medium with a predetermined, preset, or optimal pH level and send a signal to the positive displacement pump 34 ′ to move the pH controlling medium 36 ′ into the mixing tank 22 ′ where recirculation continues. The re-circulating assembly 26 ′ may continue to mix the enzymatic digest medium 12 ′, the pH probe 30 ′ may again measure the pH level, and the monitor 32 ′ may compare the pH level to the predetermined, preset, or optimal pH level and again determine whether the pH controlling medium 36 ′ should be added to the mixing tank 22 . When the pH level reaches the predetermined, preset, or optimal pH level, the enzymatic digest medium 12 ′ is ready to be used or stored.
In example embodiments, the enzymatic digest mixing assembly 15 ′ may be used to mix the at least one enzyme 14 ′, the preservative or preservatives 18 ′, the organic material 16 ′, and water. The enzymatic digest mixing assembly 15 ′ may also be usable for mixing the pH controlling medium 36 ′ with the enzymes 14 ′, the preservative 18 ′, the organic material 16 ′, and the water to form the enzymatic digest medium 12 ′ of a predetermined, preset, or optimal pH level. For example, the enzymatic digest mixing assembly 15 ′ may produce an enzymatic digest medium 12 ′ having a pH of about 7. In example embodiments, the enzymatic digest mixing assembly 15 ′ may include a pump 24 ′ and a re-circulating assembly 26 ′. The pump 24 ′ of example embodiments may comprise a first centrifugal pump and the re-circulating assembly 26 ′ may comprise a first inductor nozzle 27 ′ associated with the pump 24 ′ and a return pipe 29 ′ for circulating the enzymatic digest medium 12 ′. In example embodiments, the pump 24 ′ may alternatively be another type of pump, for example, a chopper pump.
In example embodiments, the enzymatic digest mixing assembly 15 ′ may further include load cells 25 ′ associated with a digital scale 25 a ′ and positioned such that addition of the at least one enzyme 14 ′, preservatives 18 ′, and organic material 16 ′ can be measured. It is also contemplated that, in addition to external measuring of the ingredients, other internal measurement options such ultrasound and light beams may be used to monitor the amounts of each ingredient as it is added.
In example embodiments, the enzymatic digest mixing assembly 15 ′ may be a stationary structure. For example, the enzymatic digest mixing assembly 15 ′ may be a stationary structure used at a slaughter house. In this case, the organic material 16 ′ may be blood, for example, avian blood, and the blood may be transferred to the mixing tank 22 ′. In this particular nonlimiting example embodiment, the avian blood produced as part of a slaughter operation may be mixed with the at least one enzyme 14 ′ and the preservative or preservatives 18 in the enzymatic digest mixing tank 22 ′. Due to the presence of the preservative 18 , the mixture of the blood, the enzymes 14 ′, and the preservative 18 ′ may be stored for a relatively long period of time. Thus, the enzymatic digest medium 12 ′ may be stored in the mixing tank 22 ′ for an indefinite period of time or may be pumped to a holding tank for an indefinite period of time. In example embodiments, a pH of the enzymatic digest medium 12 ′ may be controlled via the pH adjustment assembly 28 ′. For example, the pH of the enzymatic digest medium 12 ′ may be controlled to be around 7.
In example embodiments, the mixing tank 22 ′ may be transportable and thus may be moved from one facility to another facility. In the alternative, the enzymatic digest medium 12 ′ may be pumped from the mixing tank 22 ′ to a holding tank which may be loaded on a truck. Example embodiments, however, are not limited thereto. For example, the entire enzymatic digest mixing assembly 15 ′ may be truck mounted. Thus, the entire enzymatic digest mixing assembly 15 ′ may be mobile.
In example embodiments, the enzymatic digest medium 12 ′ may be usable for digesting proteins, for example, proteins from feathers. For example, an avian slaughtering operation may produce by products such as blood, offal, and feathers. The blood may be used as the organic material 16 ′ in producing the enzymatic digest medium 12 ′. At least one of the feathers and offal may be collected, ground, and added to the enzymatic digest medium 12 ′ either during a production of the enzymatic digest medium 12 ′ or afterwards.
FIG. 11 is a view of a mixing system 80 ′ that may be usable for mixing animal products, for example, feathers and/or offal, with the enzymatic digest medium 12 ′. The mixing system 80 ′ may be substantially the same as the mixing system 80 illustrated in FIG. 4 . For example, the mixing system 80 ′ may comprise at least one second positive displacement pump 72 ′, which may be fluidly connected to the at least one prep tank 60 ′, 62 ′ and to the hydro pump 82 ′ such that the enzymatic digest medium 12 ′ can be moved to a hydro pump 82 ′ where output from the grinder outlet 69 ′ is mixed with the enzymatic digest medium 12 ′ to form a protein solubles mixture 84 ′. The enzymatic digest medium 12 ′ may be pumped against the grinder outlet 69 ′ and may wash ground protein waste down into the hydro pump 82 ′. The lower outlet 74 ′ of the hydro pump 82 ′ may be fluidly connected to a centrifugal chopper pump 88 ′ which may be further associated with the at least one prep tank 60 ′, 62 ′ and a recirculation piping system 92 ′ including an inductor nozzle 90 ′. This arrangement provides a way to move the protein solubles mixture 84 ′ through a chopper pump 88 ′ and into the at least one prep tank 60 ′, 62 ′ via the inductor nozzle 90 ′. The system may be arranged to generate a circular flow in the at least one prep tank 60 ′, 62 ′. The mixture 84 ′ may be continually recirculated through the chopper pump 88 ′ until it is of desired consistency and thoroughly mixed. This may require several minutes, for example, sixty (60) minutes.
In example embodiments, animal byproducts, such as feathers and offal, may be ground by grinding means 66 ′ which may be substantially the same as the grinding means 66 . As in the previous non-limiting example embodiments, the animal by products, for example, the feathers and/or offal, may mix with the enzyme digest medium 12 ′ in a closed connection 71 ′ which may be substantially the same as the closed connection 71 .
In example embodiments, the at least one prep tank 60 ′, 62 ′ may be a jacketed prep tank that may be heated by injecting steam into the jacket. For example, the at least one prep tank 60 ′, 62 ′ may be a conventional cone bottomed tank. Thus, the at least one prep tank 60 ′, 62 ′ may be heated during the mixing process. For example, the at least one prep tank 60 ′, 62 ′ may be heated such that a temperature of the mixture 84 ′ is heated to about 110° F. or to a range up to about 125° F. or below.
In example embodiments, the at least one prep tank 60 ′, 62 ′ may be a truck mounted or may be part of a fixed structure. Thus, the at least one prep tank 60 ′, 62 ′ may be stationary or mobile.
In example embodiments, after the mixture 84 ′ of the animal product and the enzymatic digest medium 12 ′ has been thoroughly mixed in the at least one prep tank 60 ′, 62 ′ and the animal byproducts have been properly liquefied by the enzymatic digest medium 12 ′, the mixture 84 ′ may be sent to a dryer, for example, a drum dryer, a conveyor dryer, a spray dryer, or a fluid bed dryer, which may be used to dry the mixture 84 ′.
In example embodiments, when only feathers are used as the animal byproducts, the enzymatic digest medium 12 ′ may only contain keritinase and the enzymatic digest medium 12 ′ may be controlled to have a pH of between about 6 and about 8, for example, about 7. In addition, when only feathers are used as the animal byproducts, the mixture 84 ′ may be thoroughly digested provided it is mixed for a time, for example, greater than about twenty minutes up to about 1½ hours, at a temperature of about 100 F to a temperature at or below about 125 F. Applicants have found that a mixture of one part blood and preservative to about two parts feathers is acceptable for producing a mixture 84 ′ which is thoroughly digested within about an hour. In this particular embodiment, because feathers contain relatively little fat, the mixture 84 ′ may be dried in the dryer without a need to remove fat therefrom.
In example embodiments, the mixture 84 ′ may be stored for a relatively long time. For example, the mixture 84 ′ may be stored for several months. In addition, because the mixture 84 ′ is substantially liquid, the mixture 84 ′ may be pumped from the at least one prep tank 60 ′ and 62 ′ to a holding tank. The holding tank may be a stationary structure. In the alternative, the holding tank may be movable by a truck. Thus, the mixture 84 ′ may be moved from one location to another location. Because the mixture 84 ′ may be moved, a location of a dryer may vary. For example, the dryer may be at a slaughterhouse. In the alternative, the dryer may be located at a site which is remote from the slaughterhouse. In example embodiments, the dryer may be located between slaughterhouses. For example, if a certain region includes two slaughterhouses separated by fifty miles, the dryer may be located between to the two slaughterhouses, for example, twenty five miles from each slaughterhouse.
In example embodiments, when only feathers and offal are used as the animal byproducts, the enzymatic digest medium 12 ′ may contain keritinase, protease, lipase or some combination thereof and may be mixed to have a pH of about 7. In addition, when only feathers and offal are used as the digested protein, the mixture 84 ′ may be thoroughly digested in about fifteen minutes to about one hour provided it is mixed at a temperature of about 110 F to about 120 F and not above about 125 F. Applicants have found that a mixture of one part blood and preservative to about two parts feathers and offal is acceptable for producing the mixture 84 ′ which may be digested within about an hour. In this particular embodiment, because feathers and offal contain relatively little fat, the substantially liquefied mixture 84 ′ may be dried in the dryer without a need to remove fat therefrom, however, the fat may optionally be separated prior to drying the remaining substantially liquefied mixture.
Example embodiments are not limited to treating only feather and offal. For example, the apparatus of example embodiments may also be usable for digesting other animal byproducts such as heads, feet, necks, and backs of birds along with blood and offal or without offal. As in the earlier explained embodiments, at least one of the feet, necks, and backs may be fed into the grinding means 66 ′ and then mixed with the enzymatic digest medium 12 ′ in the at least one prep tank 60 ′ and 62 ′. For example, the ground heads, feet, neck, and backs may be mixed with the enzymatic digest medium 12 ′ for greater than about twenty minutes (for example, about one hour) at a temperature between 100 F and 120 F and a pH of between about 6 and about 8, for example, about 7. In example embodiments, the enzymatic digest medium 12 ′ may include at least one of lipase, protease, and amylase to digest at least one of the ground heads, feet, neck and backs.
Thus, example embodiments has been described in an illustrative manner. It is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than of limitation.
Many modifications and variations of example embodiments are possible in light of the above teachings. For example, it may be possible for all parts of the system to be made in mobile form or for none of the system to be mobile. Many different pumps are available and may be used according to need. The enzymatic digest medium can be altered to accommodate different protein/bone/feather combinations. Therefore, within the scope of the appended claims, the inventor so defines his invention.
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Example embodiments provide an apparatus that is useful for recycling protein waste and producing fuel from protein waste. Waste is ground by a grinding means and digested by a enzyme digest medium composed of enzymes, preservatives, inedible egg and or a waste fluid that may include other protein sources with or without fat. The ground proteins are digested with the enzyme in recirculated digest tanks. Fat can be collected from the tank by addition of acid and separation of fat from water with a centrifuge. Alternatively the ground protein and enzyme can be fermented and gas collected from the digest tank in a pressure tank with a compressor. The protein solubles are emulsified, separated from water, and extruded before drying. Either fat or gas can be used to fuel a dryer. Example embodiments provide a highly digestable paletable food stuff from protein waste which is usable for pet, livestock, or an aquaculture diet.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 13/069,513, filed Mar. 23, 2011 (now U.S. Pat. No. 8,088,469) which, in turn is a divisional application of U.S. patent application Ser. No. 12/151,256, filed May 5, 2008 (now U.S. Pat. No. 7,935,406).
BACKGROUND OF THE INVENTION
The invention relates to an assembly of several sheet pile wall components and at least one pair of connecting profile strips with constant cross section as viewed longitudinally to join two sheet pile wall components, whereby the first of the two connecting profile strips includes a base attached to a first sheet pile wall component in the assembly, a neck strip projecting from the base along a prescribed main assembly direction, and a head strips provided on the free end of the neck strip of larger cross section onto which a claw strip partially surrounding the head strips, and the second of the two connecting profile strips includes a base attached to a second sheet pile wall component and a claw strip onto which a head strips may be hung. Further, the invention relates to a welded-on strip for use in such an assembly.
Assemblies of the type mentioned at the outset consist of sheet pile wall components such as sheet piles and carrier elements (for example, tubular piles T-carriers, and double T-carriers). The longitudinal edges of the sheet piles are equipped with lock strips that are engaged together when the sheet pile wall is erected. So-called connecting profiles equipped with corresponding locking configuration into which to secure the sheet piles serve to connect the carrier elements. The connecting profile strips are either provided with connection strips by means of which the connecting profile strip is pressed onto the form elements such as carrier flanges provided on the carrier elements, or alternatively each of the connecting profile strips is equipped with a base instead of connection strips. The connecting profile strip is attached directly to the carrier element, preferably by welding, or also by bolting or riveting, by means of this base. The connecting profile strips may also be attached to a spar of the sheet pile between the longitudinal edges provided with locks in order to be able to couple the sheet pile with, for example, another sheet pile or with a carrier element.
Further, assemblies are also erected using sheet pile wall components that are formed exclusively of carrier elements coupled together, for example tubular piles. The carrier elements are subsequently equipped with corresponding connecting profile strips in order to connect the carrier elements together. A pair of welded-on profile strips is known from DE 202 20 446 U1 that serves to connect together two tubular piles. Further, it is known from the state of the art to use slotted tubes and T-carriers as connection elements to connect tubular piles. For this, a longitudinally-slotted tube of smaller diameter is welded onto a tubular pile while the T-carrier is so attached to an adjacent tubular pile such that its T-beam is inserted into the slotted tube for connection, while the spar of the T-carrier welded to the tubular pile extends through the slot of the slotted tube.
SUMMARY OF THE INVENTION
Based on this state of the art, it is the principal objective of the present invention to provide an assembly of the type mentioned above, as well as a welded-on profile strip useable for such an assembly, that may be more universally used than is the state of the art, and that the most varied configurations of the most varied sheet pile wall components may be realized by its use.
Based on the invention, the objective is achieved in a connecting profile strip of the type described above, wherein the head strips of the first connecting profile strips serve both to secure the claw strip of a sheet pile as a sheet pile wall of the second connecting profile strip, and wherein the claw strip of the second connecting profile strip serves both to secure the head strips of a sheet pile as a sheet pile wall and to secure the head strips of the first connecting profile strip.
In the assembly based on the invention, a pair of connection element elements equipped with a so-called ball-and-socket lock configuration is used, namely a head strips on the first connecting profile strip and a claw strip on the second connecting profile strip. The head strips and the claw strip are so configured that they may directly coupled first with the head strips and claw strips of conventional sheet pile, particularly PZ and PZC sheet piles, and second, directly with one another, whereby the main assembly direction is determined by the longitudinal direction of the neck strips along which the head strips and claw strips are engaged with one another in a neutral position. This makes it possible simply to connect PZ and PZC sheet piles with carrier elements such as tubular piles and T-carriers or double-T-carriers, to which the base of each connecting profile strip is connected by means of welding, bolting, or riveting.
Thus, in an advantageous embodiment of the assembly based on the invention, it is proposed that the second connecting profile strip include a neck strip projecting along a specified main assembly direction at whose end the claw strip is provided. The additional provision of a neck strip between the claw strip and bas of the second connecting profile strip makes it possible to couple directly together carrier elements for which a minimum separation between the carrier elements must be maintained. The problem thus often exists that, because of conventional ramming and vibration tools currently available to the market by means of which sheet pile walls are driven into the ground, when installing tubular piles and double-T-carriers, adequate space must be maintained between them to allow proper operation of the tools. Provision of a properly-dimensioned neck strip for both the first and the second connecting profile strip allows tubular piles and double-T-carriers to connect them directly together and simultaneously drive them into the ground.
The neck strips of the two connecting profile strips are of such length dimensions that a defined minimum separation is maintained between the two sheet pile walls provided with the connecting profile strips when the two connecting profile strips are engaged directly with each other. This minimum distance for this is dependent on the type of tool used to drive the sheet pile walls, and preferably is approximately within the range of 160 to 200 mm, and most preferably at 180 mm.
In order to ensure the most uniform loading possible of the mounting points of the connecting profile strips, it is advantageous for the length of the neck strip of the second connecting profile strip viewed along the main assembly direction is at least approximately the same as the length of the neck strip of the first connecting profile strip. In this manner, it is ensured that the torque at the mounting points caused by cross forces perpendicular to the longitudinal direction of the connecting profile strip during the driving of the sheet pile walls into the ground at the head strips or claw strip is approximately the same, particularly when they are directly engaged with each other.
Since the sheet pile walls often tend to become twisted longitudinally because of ground conditions such as large underground rocks, it is advantageous for the locks engaged with each other allow pivoting movement to a limited extent within the locks without the lock strips engaged together may separate. Tubular piles tend to rotate slightly viewed along the longitudinal axis while being rammed into the ground. Based on the invention, it is recommended in an advantageous expansion of the assembly based on the invention to form the head strips of the first connecting profile strip such that the head strips possesses an oval or round cross section while the claw strip of the second connecting profile strip forms a lock chamber to receive the head strips in which the jaw and the lock chamber themselves are so dimensioned that the head strips and the claw strip may pivot by an angle in the range of ±15° to ±25°, preferably ±20°, about the main assembly direction without the head strips becoming separated from the claw strip.
In order to erect as strong a wall of sheet pile walls as possible, it is proposed for an embodiment of the assembly based on the invention to attach at least one of the two connecting profile strips to a sheet pile wall formed as a carrier element. For this, a tubular pile, a T-carrier, or a double-T-carrier is suitable as a carrier element. It is further conceivable to provide carriers that are directly adjacent to each other with a first and a second connecting profile strip, whereby the two connecting profile strips are directly engaged with each other. In this manner, walls of tubular piles or double-T-carriers may be erected. For this, it is of particular advantage that the length of the neck strips of the two connecting profile strips be so selected that the afore-mentioned tool may be used with no problems. It is also conceivable to attach one of the connecting profile strips directly to the sheet pile wall itself but at a separation from the longitudinal edges provided with the lock strips while the other of the two connecting profile strips is attached to a carrier element, for example a tubular pile and is engaged with the connecting profile strip attached to the sheet pile wall. A sheet pile wall of sheet piles may be simply and elegantly supported in this manner.
Alternatively, it is proposed to attach the two connecting profile strips to carrier elements and to insert at least one sheet pile between the two connecting profile strips.
The above-described assemblies may be combined with one another in several ways so that several pairs of connecting profile strips and a large number of varying sheet pile wall may be coupled together in a suitable manner.
According to an additional aspect, the invention relates to a welded-on profile strip as defined in claim 10 , which may be used in the assembly based on the invention. The welded-on of has a claw strip and a welded-on base to attach the welded-on profile strip to a sheet pile wall, preferably to a carrier element. To solve the above-mentioned task, a neck strip is formed at a separation from the welded-on base along a specified assembly direction at whose end the claw strip is provided.
In an advantageous extension of the welded-on profile strip, the claw strip is formed of two arc-shaped, preferably mirror-reflected claw strips that form a lock chamber to receive a head strips and whose free ends facing each other form a jaw. The arc-shaped progression of the claw strips provide the lock chamber with an essentially round or oval cross section within which a head strips with round or oval shape is first held securely, and second, may be pivoted through a limited range that is suitable for insertion into the ground. For a head strips with oval cross section in which the main axis of the oval extends perpendicular to the main assembly direction, the lock chamber of the claw strip is preferably also oval, whereby here the main axis of the oval is also perpendicular to the main assembly direction. For this, the largest dimension of the lock chamber perpendicular to the main assembly direction is larger than the largest dimension of the head strips perpendicular to the main assembly direction by a factor of 1.2 to 1.4 times.
In order to allow adequate pivoting motion of the head strips within the claw strip, it is further proposed in a particularly advantageous embodiment to form the jaw of the claw strip such that the center lines of the free ends of the two claw strip intersect the axis of symmetry of the claw strip at a point outside the jaw. For this, the distance from this intersection point to the jaw is preferably 0.5-1.5 the value of the wall thickness of the hook strip.
According to another embodiment of the welded-on profile strip according to the invention, the claw strip of the second connecting profile strip includes a cross spar perpendicular to the longitudinal dimension and two connecting strips that extend at least approximately rectangular to the cross spar and that are at a distance from one another whose ends are shaped into hooks, whereby the free ends of the claw strip facing each other define a jaw of a lock chamber formed by the cross spar, the connecting strips, and the hook strip. In this manner, a lock chamber results that possesses a rectangular or square cross section.
The jaw width of the lock chamber is selected to be smaller than the largest dimension of the head perpendicular to the main assembly direction of the head strips to be secured, whereby the largest dimension of the head of the head strips is preferably 1.3 to 1.6 times the jaw width. The width of the lock chamber perpendicular to the main assembly direction is thus preferably 1.3 to 1.6 times the largest dimension of the head perpendicular to the main assembly direction of the head strips to be secured. The length of the lock chamber may vary according to application, and lies preferably within the range of 1.2 to 1.6 times the width of the lock chamber. If these shape properties are maintained for the lock chamber, it is first ensured that the head strips cannot escape from the lock chamber even though both pivoting movement and longitudinal movement may occur relative to the welded-on profile strip. For this, the dimension of the lock chamber viewed along the longitudinal direction of the neck strip is at least 0.5 as great as the length of the neck strip of the welded-on profile strip.
In specific application cases such as the use of the welded-on profile strip to erect sheet pile walls along waterways, it is necessary to seal the interface between head strips and welded-on profile strip. It is proposed for this purpose to provide a guide channel for a seal at the cross spar of the welded-on profile strip. Suitable seal material may be inserted via this guide channel that at least partially fills the lock chamber and thus provides a seal.
For a full understanding of the present invention, reference should now be made to the following detailed description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 top view of the front face of an embodiment of a first connecting profile strip based on the invention with a head strips, a neck strip, and a base for attachment to a sheet pile wall.
FIG. 2 top view of the front face of a first embodiment of a second connecting profile strip with a claw strip of C-shaped cross section, a neck strip, and a base for attachment to a sheet pile wall.
FIG. 3 top view of the front face of a second embodiment of a second connecting profile strip with a claw strip of square cross section.
FIG. 4 top view of a mutation of the second connecting profile strip shown in FIG. 3 .
FIG. 5 top view of an assembly of several tubular piles that are coupled together by means of the connecting profile strips shown in FIGS. 1 and 2 .
FIG. 6 enlarged top view of a detail of the assembly from FIG. 5 , in which the two connecting profile strips engaged with each other are shown enlarged.
FIG. 7 top view of an assembly of several tubular piles that are coupled together by means of the connecting profile strips shown in FIGS. 1 and 3 .
FIG. 8 enlarged top view of a detail of the assembly from FIG. 7 in which the two connecting profile strips engaged with each other are shown enlarged.
FIG. 9 top view of an assembly of several double-T-carriers whose flanges are coupled together by means of the connecting profile strips shown in FIGS. 1 and 3 .
FIG. 10 top view of an assembly of two PZ sheet piles coupled together that are coupled to two tubular piles by means of the two connecting profile strips shown in FIGS. 1 and 2 .
FIG. 11 top view of an assembly of two PZ sheet piles coupled together that are coupled to two double-T-carriers by means of the two connecting profile strips shown in FIGS. 1 and 2 .
FIG. 12 top view of an assembly of four PZ sheet piles coupled together, whereby two of the PZ sheet piles are coupled to two tubular piles by means of the two connecting profile strips shown in FIGS. 1 and 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will now be described with reference to FIGS. 1-12 of the drawings. Identical elements in the various figures are designated with the same reference numerals.
FIG. 1 is a top view of the front face of an embodiment example of a first connecting profile strip 10 based on the invention. The connecting profile strip 10 possesses constant cross section when viewed longitudinally, and is in the form of a welded-on strip. For this, the connecting profile strip 10 possesses a base 12 shown to the left in FIG. 1 that possesses a slightly arched cross-sectional shape. The arched shape of the base 12 simplifies welding of the base onto surfaces with either flat or arched cross section.
A neck strip 14 projects from the base 12 along a main assembly direction X whose free end is shaped into a head strip 16 . The head strips 16 possesses an oval cross section, whereby the main axis of the oval head strips 16 extends perpendicular to the main assembly direction X. The head strips 16 matches the shape and form of a head strips of a conventional ball-and-socket connection.
The greatest dimension a of the head strips 16 along the main assembly direction X is about 2 to 2.5 times as great as the wall thickness of the neck strip 14 . The length c of the neck strip 14 viewed along the main assembly direction X is approximately five times of the greatest dimension d of the head strips 16 viewed along the main assembly direction X, as is shown by the dashed imaginary projection of the oval.
FIG. 2 shows a top view of the front face of a first embodiment example of a second connection profile strip 20 based on the invention. The connection profile strip 20 also possesses a base 22 with arched shape, from which a neck strip 24 projects along the main assembly direction X. A claw strip 26 with C-shaped cross section is formed at the free end of the neck strip 24 .
The C-shaped claw strip 26 is formed of two arc-shaped, mirror-image claw strip 28 that form a lock chamber 30 and whose free ends pointing toward each other define a jaw 32 . The arc-shaped progression of the claw strip 28 provides the lock chamber 30 with an essentially oval cross section. The lock chamber 30 is thus of such dimensions that it can receive the head strips 16 of the first connecting profile strip 10 shown in FIG. 1 .
In the illustrated embodiment example, the greatest dimension e of the lock chamber 30 perpendicular to the main assembly direction X is larger than the greatest dimension a of the head strips 16 of the connecting profile strip 10 perpendicular to the main assembly direction X by a factor of 1.2.
The jaw 32 of the claw strip 26 is in turn to be shaped such that the center lines 34 of the free ends of the two claw strip 28 intersects with the axis of symmetry of the claw strip 26 at a point S outside the jaw 32 . For this, the separation of the intersection point S to the jaw 32 is preferably 0.5 to 1.5 times the value profile strip the wall thickness f of the claw strip 28 . The length g of the hook strip 28 essentially corresponds to the length c of the hook strip 14 of the first connecting profile strip 10 .
The lock chamber 30 of the claw strip 26 thus dimensioned first ensures a secure hold of the claw strip 16 , while the head strips 16 on the other hand may be pivoted within a predetermined pivot range within the lock chamber 30 , as will be explained later.
FIG. 3 shows a top view of the front face of a second embodiment example of a second connecting profile strip 50 based on the invention. Here also, the connecting profile strip 50 includes a base 52 and a neck strip 54 extending along the main assembly direction X. The end of the neck strip 54 is formed into a claw strip 56 with rectangular cross section.
The claw strip 56 includes a cross spar 58 extending perpendicular to the longitudinal direction of the neck strip 54 and two straight connection element strips 60 extending at least approximately perpendicular to the cross spar 58 and separated from one another. The free ends of the two connection element strips 60 are formed into claw strip 62 , whereby the free ends of the claw strip 62 are facing each other, forming a jaw 64 . The cross spar 58 , the two connection element strips 60 , and the two claw strip 62 enclose a lock chamber 66 with rectangular cross section.
The width h of the jaw 64 profile strip the lock chamber 66 is of smaller dimension than the greatest dimension a of the head strips 16 of the first connecting profile strip 10 viewed perpendicular to the main assembly direction X. The width y of the lock chamber 66 perpendicular to the main assembly direction X is approximately 1.5 times the value of the greatest dimension a of the head strips perpendicular to the main assembly direction X, while the length x of the lock chamber 66 is approximately 1.2 times the value of the width y of the lock chamber 66 . The length x of the lock chamber in the illustrated embodiment example represents about 0.5 times the value of the length I of the neck strip 54 of the connecting profile strip 50 .
FIG. 4 is a top view of a connecting profile strip 70 , a mutation of the second connecting profile strip 50 shown in FIG. 2 whose neck strip 72 is formed to be shorter while the claw strip 74 is formed correspondingly longer. The essential shape characteristic of this mutation is an access channel 78 formed on the cross spar 76 of the claw strip 74 , by means of which suitable seal material may be inserted that at least partially fills the lock chamber 80 , thus providing a seal.
The previously-described connecting profile strips 10 , 20 , 50 , and 70 are suited to connect different sheet pile walls such as tubular piles 90 , double-T-carriers 92 , and PZ or PZC sheet piles 94 . Subsequently, a few minor assembly versions are shown regarding how the connecting profile strips 10 , 20 , and 50 may be used in combination with one another in order to couple the previously-described sheet pile walls together.
FIG. 5 shows in top view a first assembly 100 of several tubular piles 90 . The tubular piles 90 positioned adjacent to one another are coupled together by means of the two connecting profile strips 10 and 20 shown in FIGS. 1 and 2 . The connecting profile strips 10 and 20 are welded onto the mantle surface of the tubular piles 90 , and extend along the entire axial length of the tubular pile 90 .
FIG. 6 shows an enlarged top view of a detail of the assembly from FIG. 5 , in which the connecting profile strips 10 and 20 engaged with each other are shown in an enlargement in order to make clear that, because of the configuration of the connecting profile strips 10 and 20 , first, a pivoting of the connection profile strips 10 and 20 through a pivot-angle range α of approximately ±20° is possible, whereby because of the lengths of the neck strips 14 and 24 , the pivot point lies approximately in the center between the two tubular piles 90 . Second, the tubular piles are maintained at a predetermined minimum separation distance z.
FIG. 7 shows a top view of a second assembly 110 of several tubular piles 90 that are coupled together by means of the connecting profile strips 10 and 50 shown in FIGS. 1 and 3 . Here also, the connecting profile strips 10 and 50 are welded onto the mantle surface of the tubular piles 90 , and extend along the entire axial length of the tubular piles 90 .
FIG. 8 shows an enlarged top view of a detail of the assembly 110 from FIG. 7 , in which two connecting profile strips 10 and 50 engaged with each other are shown enlarged. As with the embodiment example shown in FIG. 6 , the two connecting profile strips 10 and 50 allow pivoting movements through a pivot-angle range α of approximately ±20°.
FIG. 9 is a top view of an assembly 120 of several double-T-carriers 92 , whose flanges 96 are coupled together by means of the connecting profile strips 10 and 50 shown in FIGS. 1 and 3 .
FIG. 10 shows a top view of an assembly 130 of two PZ sheet piles 94 coupled together that are coupled to two tubular piles 90 by means of the two connecting profile strips 10 and 20 shown in FIGS. 1 and 2 .
FIG. 11 shows a top view of an assembly 140 of two PZ sheet piles 94 coupled together that are coupled to two double-T-carriers by means of the two connecting profile strips 10 and 20 shown in FIGS. 1 and 2 . For this, the two connecting profile strips 10 and 20 are welded to the spars 98 of the double-T-carrier 92 .
FIG. 12 shows a top view of an assembly 150 of a total of four PZ sheet piles 96 coupled together, whereby two of the PZ sheet piles 96 are coupled to two tubular piles 90 by means of the two connecting profile strips 10 and 20 shown in FIGS. 1 and 2 .
The embodiments shown in FIGS. 5 through 12 show only a small portion of potential combinations. Particularly essential to the invention is the fact that the connecting profile strips 10 , 20 , 50 , and 70 are so configured that they may be connected to conventional ball-and-socket joints or to themselves in a simple manner.
There has thus been shown and described a novel arrangement of multiple sheet pile components and welding profile therefor which fulfills all the objects and advantages sought therefor. many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. all such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.
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An interlocking sheet profile connector comprises a first and a second connecting profile. The first connecting profile includes a base attached to the first sheet pile wall element, a neck strip projecting from the base and a head strip of larger cross section on the free end of the neck strip. The second connecting profile possesses a base attached to a second sheet pile wall element and a claw strip to secure a head strip. The head strip of the first connecting profile is thus configured both to secure the claw strip of a sheet pile as a sheet pile wall element and to secure the claw strip of the second connecting profile, while the claw strip of the second connecting profile serves both to secure the head strip of a sheet pile as a sheet pile wall element and to secure the head strip of the first connecting profile.
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BACKGROUND OF THE INVENTION
This invention relates to a top chord member used in the construction of the sidewalls of a gondola or hopper type railway car. It relates particularly to an aluminum top chord member especially suitable for railway cars constructed substantially of aluminum sheet and plate. It also relates to an aluminum top chord member especially adapted for use in railway cars which are unloaded in a rotary car inversion unloading device or in a vibrating shakeout machine both of which facilitate the unloading of bulk material from the car.
Open top gondola or hopper type railway cars are generally comprised of a metal floor, sidewalls and end walls. While such cars have most frequently been made of steel, many cars are being made substantially of aluminum sheet and plate to reduce the overall weight of the car and thereby increase its carrying capacity. The sidewalls of the gondola and hopper cars are stiffened and reinforced by a plurality of spaced, parallel, vertical side posts. A longitudinal top chord member extends along the tops of each sidewall and the side posts to further strengthen the sidewalls of the car.
Open top gondola railway cars that are used to carry bulk materials, such as coal, are frequently unloaded in a rotary car dumper which is a device that clamps onto the top chords of the sidewalls of the car and rotates the entire car and its contents to an inverted position to quickly unload the contents. Another unloading device, often used for hopper cars, is a car shaker that also clamps onto the top chords of the sidewalls of the car and imparts vibrating or shaking forces to the car to dislodge its contents and facilitate its unloading. Both of these car unloading devices impart concentrated and unusual localized forces to the top chord members of the car.
In the past, railway car designers have recognized the need for special top chord members to accept these unloading operations.
U.S. Pat. Nos. 2,748,723, and 4,561,361 disclose hot rolled steel bulb sections which are especially designed to accommodate rotary car dumpers or car shaker devices. While these rolled bulb sections have proven satisfactory for cars and top chord members made of steel, they have lacked sufficient strength and integrity when used for aluminum cars and top chord members. U.S. Pat. No. 4,840,127 is an example of a top chord member designed especially for use in aluminum gondola or hopper cars in which the top chord member is a rectangular, tubular extrusion having a thickened stem portion to better resist bending moments where the top chord is fastened to the sheets and posts that make up the sidewall of the car. Such a top chord, while more suitable for aluminum cars than the rolled bulb angle, lacks sufficient strength and integrity for extended use in the rotary or shaker type car unloading devices.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a top chord member for an aluminum gondola or hopper railway car that is strong, lightweight and suitable for extended use in rotary or shaker type car unloading devices.
It has been discovered that the foregoing objectives can be attained by a rectangular, tubular top chord member made from an aluminum extrusion in which the top chord member is comprises of parallel top and bottom walls, parallel sidewalls and an attachment leg extending below the bottom wall as an extension of one of the sidewalls. The top wall of the top chord member has portions adjacent to the sidewalls which are considerably thicker than the center portion of the top wall and the sidewalls and the bottom wall.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of an open top gondola car of this invention having a top chord member according to this invention.
FIG. 2 is a sectional view of the gondola car of FIG. 1, taken along section lines 2--2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the top chord member of this invention is shown in FIGS. 1 and 2. FIG. 1 illustrates an open top gondola railway car 1 having a pair of sidewalls 2, a pair of end walls 3 and a concave floor structure 4. The sidewalls 2 are stiffened and reinforced by a plurality of spaced, parallel, vertical side posts 5. A longitudinal top chord member 6 extends along the top of each sidewall 2 and the tops of side posts 5 and is fastened to further strengthen the sidewalls 2 of the car 1.
As best shown in sectional view FIG. 2, the top chord member 6 comprises a rectangular, tubular aluminum extrusion having a top wall 10 and a bottom wall 11 parallel to each other and an inner sidewall 12 and an outer sidewall 13 parallel to each other. An attachment leg 14 extends below the bottom wall 11 as an extension of inner sidewall 12. As shown in FIG. 2, this attachment leg 14 is used to fasten the top chord member 6 to the sidewall sheets 2 and side posts 5 with rivets 18 or other suitable fasteners. The bottom wall 11 of the top chord member 6 bears directly on the tops of the side posts 5.
The top wall 10 of top chord member 6 has an inner portion 15 and an outer portion 16 adjacent to the respective sidewalls 12 and 13 which are considerably thicker than the central portion 17 of the top wall 10 or the sidewalls 12 and 13 on the bottom wall 11. The thicker portions 15 and 16 serve as a pair of contact surfaces or wear pads which contact the rotary car dumper or car shaker devices and transfer the forces from those unloading devices to the car structure. Having a pair of such contact points not only reduces the wear on the top chord member 6 but provides better protection to the top chord member 6 from damage as these car unloading devices are clamped onto the top chord member 6. The pair of contact surfaces or wear pads 15 and 16 insures that the forces from the unloading devices are uniformly distributed between the sidewalls 2 and the side posts 5. In addition, the use of a thinner portion 17 between the two thicker portions 15 and 16 of the top wall 10 of the top chord member 6 provides a better and more uniform distribution of lateral bending stress in the top chord member 6.
A specific examples of a top chord member 6 of this invention used a 5 inch (12.7 cm) square tubular extrusion of 6061-T6 aluminum with a 3.25 inch (8.255 cm) long attachment leg 14. Sidewalls 12 and 13, and attachment leg 14 were all 0.30 inches (0.76 cm) thick. Bottom wall 11 was 0.25 inches (0.635 cm) thick. Top wall 10 had thicker portions on wear pads 15 and 16, 1.1875 inches (3.02 cm) wide and 0.625 inches (1.59 cm) thick. The central portion 17 was 0.30 inches (0.76) thick and 2.62 inches (6.65 cm) wide.
The foregoing description and preferred example explain and illustrate the invention and the invention is not limited thereto, except as defined by the claims. Those skilled in the art of rail car design will be able to make modifications and variations without departing from the scope of this invention.
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A sidewall and top chord member for an open top gondola or hopper railway car. The top chord member is a lightweight rectangular tubular extrusion of aluminum having a pair of spaced wear pads on the top surface thereof to contact rotary or shaker type car unloading equipment.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of application Ser. No. 10/753,423, filed Jan. 9, 2004, entitled GUARD RAIL SYSTEM, which is a Continuation-in-Part of application Ser. No. 09/994,736, filed Nov. 28, 2001, entitled GUARD RAIL SYSTEM, which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] This invention relates to guard rail systems. In particular, this invention relates to a prefabricated guard rail system, components for a guard rail system and kits of components for a guard rail system, which is strong, inexpensive, easy to assemble and self-aligning, and meets the requirements of local building codes.
BACKGROUND OF THE INVENTION
[0003] Guard rails are used around decks, staircases and other elevated structures, to prevent injury and possible death from falling off of the edge of such structures. Most building codes have rigid requirements for guard rails, both in terms of when they are required and certain construction parameters, including for example the maximum spacing between balusters, length of span, height and load requirements.
[0004] The installation of guard rail systems can be a very labour intensive procedure. Balusters must be installed at precise intervals, and be substantially true to the vertical, both to comply with building code requirements and to be aesthetically acceptable.
[0005] Guard rails can be constructed from lumber, and frequently are in order to keep costs down. In a typical lumber guard rail construction balusters or pickets are nailed or screwed to top and bottom rails, which in turn are nailed to posts secured to or around the structure. A considerable amount of attention is required to ensure that the balusters are evenly spaced and vertical, and there is a limit to the aesthetic appeal which can be achieved. Moreover, the resulting guard rail is subject to separation, warping and other weathering effects over time, due to limits on the strength and degree of structural integration which can be achieved using nails and lumber.
[0006] The fabrication of components for guard rail systems can be facilitated by extruding components, for example out of a synthetic wood composition, plastic, aluminium or another suitable material. However, whether cut from lumber or extruded, the assembly and installation of the guard rail requires considerable skill, labour and time in order to construct a guard rail which is both structurally secure and appealing.
[0007] There is accordingly a need for a guard rail system which is easy to assemble, inexpensive, and produces a durable, structurally integrated guard rail which both meets building code requirements and is aesthetically appealing.
SUMMARY OF THE INVENTION
[0008] The present invention overcomes these disadvantages by providing a guard rail system fabricated from standard-sized components, which is strong enough to meet and exceed building code requirements. According to the invention, balusters which are preferably (but not necessarily) extruded are fastened to a lower rail and to an upper retainer at fixed intervals. The balusters are provided with central bores for receiving fasteners such as screws through predrilled holes in the upper retainer and lower rail. A hand rail is slip-fitted over the upper retainer in locking relation, to provide integrated guard rail sections. In the preferred embodiment guard rail sections so assembled are fastened by means of a special bracket system to end posts to provide a safe, secure and aesthetically appealing guard rail.
[0009] The invention provides a versatile, easy to assemble and structurally secure guard rail system which can be used in any application where conventional guard rails are used.
[0010] The present invention thus provides a guard rail system, comprising a top retainer and a bottom rail affixed between at least two posts, a plurality of hollow balusters extending between the top retainer and the bottom rail, each baluster comprising a plurality of inner webs affixed to a wall of the baluster and to a bore for a fastener disposed within the baluster wall, and a hand rail affixed to the top retainer, wherein the balusters are affixed between the top retainer and the bottom rail by fasteners disposed through the top retainer and the bottom rail and into the bore.
[0011] The present invention further provides a guard rail system, comprising a top retainer and a bottom rail affixed between at least two posts, a plurality of hollow balusters extending between the top retainer and the bottom rail, each baluster comprising a plurality of inner webs affixed to a wall of the baluster and to a bore for a fastener disposed within the baluster wall, and a hand rail affixed to the top retainer, the hand rail having a bearing plate supported by an upper surface of the upper retainer, wherein the upper retainer has an exterior surface having a pair of opposed channels and the hand rail has an internal surface having a pair of complementary projections, whereby the hand rail is affixed to the upper retainer by sliding engagement between the projections and the channels.
[0012] In further aspects of the guard rail system of the invention: the top retainer and the bottom rail each have a series of pre-drilled holes for receiving the fastening members, to thereby align the balusters; a front of the bottom rail is provided with an upstanding lip spaced from the series of holes by a distance substantially corresponding to a distance between the bore and a front face of the baluster; the upper retainer has an exterior surface having a pair of opposed channels and the hand rail has an internal surface having a pair of complementary projections, whereby the hand rail is affixed to the upper retainer by sliding engagement between the projections and the channels; the hand rail is provided with a bearing plate supported by an upper surface of the upper retainer; a portion of the hand rail above the bearing plate is hollow; the balusters have a substantially square cross section and a substantially central bore; the webs extend from corners of the baluster wall to the bore; the posts are hollow and provided bosses disposed along an interior wall of the post, for abutting against a structural member disposed through each post; and/or the top retainer and bottom rail are affixed to the posts by a bracket comprising a flanged arm having depending flanges spaced apart so as to nest in grooves formed in the top retainer and bottom rail, to thereby interlock the bracket with the top retainer and bottom rail.
[0013] The present invention further provides a method of assembling a guard rail, comprising the steps of: a. pre-drilling a top retainer and a bottom rail for attachment to a plurality of hollow balusters, the top retainer having an exterior surface having a pair of opposed channels and each baluster comprising a plurality of inner webs affixed to a wall of the baluster and to a bore for a fastener disposed within the baluster wall, b. disposing fasteners through the holes into the bores to affix the balusters between the top retainer and bottom rail, c. sliding a hand rail having an internal surface having a pair of projections complementary to the channels over the upper retainer to engage the projections in the channels, and d. affixing the top retainer and the bottom rail to posts.
[0014] In further aspects of the method of the invention: the hand rail comprises a bearing plate supported by an upper surface of the upper retainer; the method includes, before step a., the step of extruding the top retainer, bottom rail, balusters and hand rail; each post is hollow and the method includes the steps of anchoring a structural member and disposing the post over a structural member; and/or the top retainer and bottom rail are affixed to the posts by a bracket comprising a flanged arm having depending flanges spaced apart so as to nest in grooves formed in the top retainer and bottom rail, to thereby interlock the bracket with the lower rail and upper retainer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In drawings which illustrate by way of example only a preferred embodiment of the invention,
[0016] FIG. 1 is an elevation of a guard rail system according to the invention on a sun deck;
[0017] FIG. 2 is a cross sectional front elevation of the guard rail system of FIG. 1 ;
[0018] FIG. 3 is a cross sectional end elevation of the guard rail system of FIG. 1 ;
[0019] FIG. 4 is a cross section of a baluster of FIG. 1 ;
[0020] FIG. 5 is a cross section of an end post of FIG. 1 ;
[0021] FIG. 6 is a cross section of the upper retainer of FIG. 1 ;
[0022] FIG. 7 is a cross section of the lower rail, baluster, upper retainer, and handrail of an embodiment of the invention;
[0023] FIG. 8 is a side elevational view of a bracket for fastening the guard rail sections to the end posts, according to one embodiment of the invention;
[0024] FIG. 9 is a plan view of a bracket, according to a further embodiment of the invention; and
[0025] FIG. 10 is an exploded perspective view of a bracket according to yet a further embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0026] FIG. 1 illustrates a guard rail system 10 according to the present invention. The guard rail system 10 is illustrated in the environment of a sun deck for purposes of example only, however it will be appreciated that the guard rail system is adaptable to any environment in which a conventional guard rail system may be used.
[0027] In a preferred embodiment the components of the guard rail system are entirely extruded, for example in accordance with the technique described in U.S. Pat. No. 5,516,472 for an Extruded Synthetic Wood Composition and Method for Making Same issued May 14, 1996 to Strandex Corporation, and Canadian Patent No. 2153659 issued Feb. 23, 1999 to Strandex Corporation, which are incorporated herein by reference. However, the components of the invention may alternatively be milled from wood, molded or extruded from plastic or metal, or otherwise suitably formed. The particular material or materials from which the components of the guard rail are formed is limited only by the requirement for sufficient structural strength in the finished railing to comply with building code requirements. FIGS. 2 and 3 illustrate the various components of the invention, comprising an end post 20 , a lower rail 30 , an upper retainer 40 , balusters 50 and a hand rail 60 . In the preferred embodiment the invention further includes a specially designed bracket 70 for fastening the guard rail sections to the end posts.
[0028] The end post 20 , illustrated in FIG. 5 , is preferably hollow and has an interior dimension which allows the end post 20 to be slip-fitted over a structural member 2 (shown in phantom in FIG. 5 ) such as a 4×4 pressure treated post, 2×4 pressure treated lumber or a 3½ inch steel pipe (for example of the type used in chain link fencing), which is anchored into the ground, deck substructure or other foundation for the guard rail 10 . In the preferred embodiment the end post 20 comprises vertical ridges 22 which snugly abut the four by four post 2 in order to fix the end post 20 in a stable, vertical position.
[0029] Rail sections are formed by a series of balusters 50 fastened to the lower rail 30 and the upper retainer 40 . The lower rail 30 and upper retainer 40 are preferably predrilled at the desired positions for the balusters, for example 4 inches on-center (OC).
[0030] The lower rail 30 , shown in FIG. 7 , preferably comprises a hollow body 32 having decorative flanges 34 depending therefrom, serves to impart aesthetic appeal to the lower rail 30 and to hide the hardware such as screws 4 which secure the balusters 50 and brackets 70 (shown in FIG. 9 ) which secure the lower rail 30 to the end post 20 . In a preferred embodiment, an alignment lip (not shown) serves the purposes of both aligning the balusters 50 along the lower rail 30 and concealing any small gap between the balusters 50 and the body 32 of the lower rail 30 after the balusters 50 have been fastened thereto.
[0031] The upper retainer 40 , shown in FIG. 6 , comprises an abutment plate 42 extending axially along the upper retainer 40 which abuts the top ends of the balusters 50 , and a pair of wings 44 which are preferably dimensioned to overlap the sides of the balusters 50 , holding the balusters 50 in place and keeping them from rotating, as shown in FIG. 3 . Preferably the row of drill holes 8 is contained within a longitudinal recess 46 , so that the heads of fasteners such as screws 6 or recessed relative to, or at least are flush with, the top face 43 of the upper retainer 40 , thereby avoiding the need to countersink screws 6 when the balusters 50 are fastened to the upper retainer 40 .
[0032] The hand rail 60 , shown in FIG. 7 , has an exterior surface 61 configured in any desired shape or pattern for usability and aesthetic appeal. The interior surface 63 of the hand rail 60 is configured to slip-fit over the upper retainer 40 . The hand rail 60 is slip-fit over the upper retainer 40 . Preferably the interior surface 63 has a bearing plate 64 having ridges or bosses 66 which bear on the top surface 43 of the upper retainer 40 , to snugly secure the handrail 60 in position. Preferably there is a hollow between the bearing plate 64 and the upper surface of the hand rail 60 , which increases strength, and reduces the cost and weight of the hand rail 60 . Also, a slight flexibility in the bearing plate 64 and the wings 62 allows the hand rail 60 to grip the upper retainer 40 when slip-fitted thereto.
[0033] The balusters 50 , shown in FIG. 4 , may be formed in any desired decorative shape, and may be symmetrical in cross section. Each baluster 50 is hollow and provided with inner webs 52 affixed to the wall of the baluster 50 and supporting a bore 54 , which preferably extends along the entire length of the baluster 50 . In the embodiment shown the balusters 50 each have a square cross section and the webs 52 extend from the corners of the baluster wall toward a central bore 54 .
[0034] The spacing between the bore 54 and the front outer face 56 of the baluster 50 corresponds to the spacing between the predrilled holes 8 and the wings 44 of the upper retainer 40 , and to the spacing between the predrilled holes 9 and the lip 36 of the lower rail 30 . Thus, when assembled in the manner described below, the balusters 50 will self align against the wings 44 and the lip 36 to align the balusters relative to one another, and to square the balusters relative to the rail section when the upper retainer 40 and lower rail 30 are affixed to the end post 20 .
[0035] Preferably, the upper retainer 40 and lower rail 30 are affixed to the end post 20 by a bracket 70 , illustrated in FIG. 8 , comprising a flat arm 72 having screw holes 78 , extending generally perpendicular to an arm 74 having screw holes 78 . The bracket 70 may be stamped or otherwise suitably formed from metal. In a preferred embodiment, depending flanges 76 are provided on the arm 74 , and are spaced apart so as to nest in grooves or recesses 31 and 41 respectively formed in the underside of lower rail 30 and upper retainer 40 , as can be seen in FIGS. 9 and 10 , thus interlocking with the lower rail 30 and upper retainer 40 for increased strength and stability. In a preferred embodiment, the bracket 70 is configured to permit the upper retainer 40 and the lower rail 30 to be affixed to the end post 20 at an angle. As shown in FIG. 10 , the bracket 70 may comprise a flat arm 72 having screw holes 78 for affixing to an end post 20 . The bracket 70 further comprises a generally perpendicular flanged arm 74 rotatably mounted on the flat arm 72 by means of a fastener 90 , such as a rivet or another suitable fastening means. The perpendicular flanged arm 74 is provided with screw holes 78 and depending flanges 76 , which are spaced apart so as to nest in the grooves or recesses 31 and 41 formed in the underside of lower rail 30 , and upper rail 40 . The flat arm 72 and the flanged arm 74 may likewise be stamped or otherwise formed from metal. While the fastener 90 in the rotating bracket 70 shown in FIG. 10 provides rotational movement over a full 360°, when the bracket 70 is mounted in a guard rail assembly, full rotation may be restricted to a range of less than 360°, since full rotation will be hampered by the interference of the upper retainer 40 , lower rail 30 , and the end post 20 . However, with the rotating bracket 70 , the guard rail assembly may be configured to surround an irregularly (non-rectangular) shaped area.
[0036] In a further embodiment, the bracket 70 is shaped to fit around a vertex of an end post 20 . Referring to FIG. 9 , the bracket 70 is provided with an angled arm 92 , which is shaped to fit around the corner of an end post 20 , preferably at a 90° angle. The angled arm 92 is provided with screw holes 78 for mounting to the end post 20 . A generally perpendicular flanged arm 74 extends from the angled arm 92 . and is provided with screw holes 78 and depending flanges 76 , which are spaced apart so as to nest in the grooves or recesses 31 and 41 formed in the underside of lower rail 30 and upper rail 40 . In the preferred embodiment, the vertex 93 of the angled bracket 70 shown in FIG. 12 truncated to provide an edge for the join 95 between the angled arm 92 and the flanged arm 74 . If the angled bracket 70 is integrally formed, for example by metal stamping or another suitable method, when formed the bracket 70 may be bent along the join 95 . Alternatively, if the bracket 70 is formed from a separate flanged arm 74 and an angled arm 92 , the join 95 may be formed by spot welding or other means.
[0037] To assemble the guard rail of the invention, the end posts 20 are fitted over suitably dimensioned structural posts 2 such as four-by-four treated lumber, and positioned to rest on the deck, floor, stair or other elevated structure. The rail sections are assembled by driving fasteners such as screws 6 through the predrilled holes 8 in the upper retainer 40 into the bores 54 in the balusters 50 . The lower rail 30 is similarly fastened to the bottom ends of the balusters 50 by driving fasteners such as screws 6 through the predrilled holes 9 into the bores 54 . The rail section so constructed is integrated and structurally secure. The rail sections may be constructed to any suitable length, and can be assembled to a single length of lower rail 30 and upper retainer 40 , depending upon the material from which the rail section is formed.
[0038] A length of hand rail 60 is cut to match the length of the assembled rail section, and slip-fitted over the upper retainer 40 by aligning ridges or bosses 62 with channels 48 and sliding the hand rail 60 along the upper retainer 40 until the upper retainer 40 is fully concealed. The rail section is then mounted between end posts 20 by brackets 70 affixed to the upper retainer 40 and lower rail 30 using suitable fastening members, in the case of a wood composite or synthetic wood composite, preferably bolts with wood or other suitable inserts (not shown), and preferably screws 6 extending through the wall of the end post 20 into the structural member 2 for strength.
[0039] It will be appreciate by those skilled in the art that the particular configurations of the components of the guard rail system of the invention may be altered to suit specific installation parameters and/or aesthetic or decorative requirements. For example, the embodiment illustrated shows plain-faced, square-shaped balusters 50 , however the balusters 50 can be formed in any other desired configuration as long as the bore 54 is spaced from the front face 56 of each baluster in a manner which allows the front face 56 to align with the lip 36 of the lower rail 30 . In the embodiment shown the side faces 58 of the balusters 50 are equidistant from the bore 54 , however this is not essential and a precise on-center spacing between balusters 50 can be obtained even if the baluster 50 is not laterally symmetrical relative to the bore 54 .
[0040] Various embodiments of the present invention having been thus described in detail by way of example, it will be apparent to those skilled in the art that variations and modifications may be made without departing from the invention. The invention includes all such variations and modifications as fall within the scope of the appended claims.
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A guard rail system fabricated from standard-sized components, preferably extruded, comprises balusters fastened to a lower rail and to an upper retainer at fixed intervals. The balusters are provided with central bores for receiving fasteners such as screws through predrilled holes in the upper retainer and lower rail. A hand rail is slip-fitted over the upper retainer in locking relation, to provide integrated guard rail sections. Guard rail sections so assembled are fastened to end posts, preferably using mounting brackets having a flanged arm which nests in grooves or recesses in the upper retainer and lower rail to provide a safe, secure and aesthetically appealing guard rail.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. Utility application Ser. No. 14/210,101, filed Mar. 13, 2014, which application claims priority to U.S. Provisional Application No. 61/782,897, having a filing date of Mar. 14, 2013. These referenced applications are incorporated herein in their entireties by this reference.
FIELD OF THE INVENTION
[0002] The inventions herein relate to devices and methods to impart charge to batteries. Still further, the present invention incorporates pulse charging methods and systems related thereto that provide improvements in charging speed, efficiency and additional benefits.
BACKGROUND OF THE INVENTION
[0003] Inadequacy of battery charging processes, especially in lithium ion (“Li-ion”) batteries, is a critical problem today. Generally speaking, while the construction of and chemical aspects of Li-ion batteries have progressed significantly since their market introduction in the early 1990's, the methods used to charge them have not changed markedly. This lack of technical progress in battery charging is felt more acutely today as society becomes more reliant on Li-ion batteries to power a myriad of mobile devices and vehicles not only in the U.S., but throughout the world.
[0004] The most prevalent method used to charge Li-ion batteries today is commonly termed “constant current/constant voltage” (“CC/CV”). A representative prior art CC/CV charging process is shown in FIG. 1 . Here, charge is applied in a constant current as long as the battery voltage remains below about 4.2 V, which is the rated V max for this cell. If the Li-ion cell exceeds its rated V max , dangerous conditions may result or, at a minimum, the battery may quickly fail. To mitigate the effects of constant current charging, charging current will taper to maintain a constant voltage; in other words, charging will switch from the constant current portion (“CC”) to the constant voltage (“CV”) portion. Maintaining the cell at constant voltage necessarily results in significant reduction in the Li-ion battery charging rate.
[0005] Practically speaking, CC/CV charging of a Li-ion battery cell means that the battery will acquire about 60-80% state of charge (“SOC”) during the CC portion. The SOC level at which transition from CC to CV occurs depends on a number of factors, including the electrode configuration and chemical composition. For the specific prior art Li-ion charge process shown in FIG. 1 , CC/CV charging of the 1000 mAh cell mobile device battery at the stated 1C rate progresses for about 36 minutes at constant current to result in about 60% SOC, at which time the constant voltage portion commences and current decreases. After about 1 hour of total charging time—about 20 minutes of constant voltage—this cell reaches about 85% SOC; however, it takes close to 2.5 hours for the cell to reach 100% SOC using CC/CV charging. A greater than 2 hour total charging time for Li-ion “energy” batteries to attain 100% SOC is the status quo today.
[0006] Somewhat counterintuitively, increasing the current does not greatly hasten attainment of the full % SOC. The battery reaches the voltage peak (i.e., approaches V max ) more quickly at application of higher current and, therefore, the constant voltage portion commences earlier. It then follows that the total time required to achieve 100% SOC will depend on the duration of the constant voltage step. The rate at which current is applied simply alters the time required for each stage. While high current can quickly fill the battery to about 70% SOC, the remaining battery capacity will be “left on the table” if the charging process is terminated at this time. If the full capacity of the Li-ion battery is desired, the user must leave the battery plugged into the charger so the constant voltage period can be completed. Put another way, the voltage response invariably resulting when a high charging current is applied to Li-ion batteries using status quo charging processes requires a tradeoff between % SOC acquisition and the ability to leverage the full available capacity of the battery to power the device (or vehicle) in which the battery is used. If one wishes to have a short charging time, one must accept less than 100% SOC; if one wishes to utilize the full capacity of the battery, one has to accept extended charging times.
[0007] As noted, for users of today's mobile devices, such as smartphones, the characteristic Li-ion battery voltage response results in a full charge requiring up to 3 hours. While the device software often indicates that the battery is at about 100% charge in about an hour, users do not actually obtain full capacity in this time, and the user will experience the need to recharge their device more frequently due to the battery having only partial capacity. Moreover, this type of battery—sometimes called an “energy” battery—is intended to provide long device use times, while still at the same time being lightweight and small to ensure appropriate use in mobile devices. Such requirements restrict the ability to use faster charging Li-ion batteries. Accordingly, fast charging is not readily available to users of mobile devices today and users must choose to either charge their batteries for longer times to enable longer periods of use or they must charge their batteries frequently and lose mobility.
[0008] Similar to “energy” batteries used for mobile devices, Li-ion electric vehicle (“EV”) battery packs in use today utilize CC/CV charging processes to achieve 100% SOC. These high rate Li-ion “power” batteries are capable of accepting charge at a higher rate than their “energy” battery counterparts, however, the trade-off for this higher charging rate is lower energy density and higher cost.
[0009] Typically, an EV user desires to achieve as much SOC as possible—which equates to vehicle range—in the shortest possible time period, so it is common for EV battery pack charging to occur at the fastest available rate given the charging system available. Level 1 charging, which uses 110 V household-type power outlets, is typically used to charge smaller battery packs such as that in the Chevy Volt®. Level 2 charging, which uses 240 V power outlets, is commonly used to charge larger batteries in household settings, as well as in public charging stations. However, for most EV battery packs, Level 2 charging will take four or more hours to achieve significant SOC/vehicle range from a single charging event.
[0010] Many commentators believe that widespread availability of low cost DC fast charging stations will be needed to accelerate adoption of EVs in the US. Accordingly, a DC charging infrastructure is now being established throughout the U.S using DC fast charging equipment (typically 480 V AC input). These high rate chargers can markedly improve charging speeds. However, much confusion exists in regard to EV fast charging times today because there is no universally agreed-to protocol to measure charging performance or to describe battery capacity. Instead, each manufacturer reports charging performance using information tailored for its specific marketing efforts. Nevertheless, a DC fast charger generally can add about 60 to 80 miles of range to a light duty PHEV or EV in about 20 minutes.
[0011] More specifically, as reported by the manufacturer, a Tesla Motors® SuperCharger station can charge to 50% of the rated battery capacity of the Model S 85 kWh battery—or 150 miles—in about 20 minutes and 80% in 40 minutes; however, it takes fully 75 minutes to achieve 100% SOC. This charging behavior is shown in FIG. 2 , where the characteristic voltage behavior resulting from application of a high charging rate is shown by the deviation of the SOC curve from linear after the battery reaches 50% SOC. Tesla Motors' marketing materials indicate that charging of the final 20% SOC takes approximately the same amount of time as the first 80% SOC due to a necessary decrease to charging current to help top off the cells. As stated in Tesla Motors marketing literature: “It's somewhat like turning down a faucet to fill a glass to the top without spilling.” Put another way, while Tesla Motors' SuperCharger stations can supply the necessary power to fully charge the battery pack in about 40 minutes, the voltage response that invariably results from application of a high constant charging current does not allow the battery to be charged to 100% SOC unless the charging process is extended to more than 1 hour.
[0012] Similarly, a car configured for use with a CHAdeMO DC fast charging system, such as that used with the Nissan Leaf®, can recharge from empty to 80% SOC in about 30 minutes. Reportedly, the Leaf does not allow the battery to be charged beyond 80% SOC, presumably due to manufacturer's concerns regarding voltage behavior upon repeated fast charging to high SOC percentages.
[0013] The behavior of Li-ion EV battery packs in DC Fast Charging comports with the charging process shown in FIG. 1 in that application of a high rate constant current causes a voltage response that prevents charge from being accepted by the battery at the highest application of constant current for extended periods. Certainly, each automotive OEM seeks to extract as much performance as possible using sophisticated battery management systems and other types of power controls. However, by using conventional DC fast charging frameworks, the % SOC achievable is limited by the inherent voltage behavior of the battery resulting from application of fast charging.
[0014] The voltage behavior resulting from constant current fast charging also negatively influences EV performance in ways that impact the consumer beyond charging speed delays and % SOC concerns, namely in relation to battery sizing and the downsides related thereto.
[0015] As is well-known, today's high cost of Li-ion batteries makes EVs much more expensive than comparable gasoline-powered vehicles. Overall cost of the battery is, of course, directly related to the materials used to fabricate the battery. To improve overall performance of the EV, many OEMs have elected to oversize EV battery packs. For example, in a Chevy Volt®, about 20% of the battery is not considered when capacity-related specifications are reported, which means that the rated capacity of the Volt battery pack is about 20% less than the actual capacity as measured by the materials used in the battery pack. While actual data about other battery packs is hard to come by due to the proprietary nature of EV batteries, it is generally understood by experts that such oversizing is present in all EVs today. Certainly, some of the oversizing results from the need to keep discharge/driving behavior within a required % SOC where driving operation (i.e., discharge behavior) is more consistent. However, much of today's battery oversizing is also conducted to provide additional battery material that will become usable for power when battery % SOC begins to decline over the required life of the battery pack (currently 10 years).
[0016] Even assuming that oversizing battery packs does not add cost to the EV (that is, assuming that marked price reductions will be achieved in the near future), larger-than-necessary battery packs impact available consumer space and increase vehicle weight while not adding any additional range. If Li-ion EV battery packs could be charged faster without causing as much stress to the Li-ion battery as that seen from conventional DC fast charging, there would be less need to oversize the battery pack. This would enable additional design freedom for EV OEMs (e.g., space for passengers and luggage) and would also allow modest additional vehicle range at no cost due to lower battery weight. Perhaps more importantly, keeping battery size and/or footprint the same as today could allow the entire battery capacity to be used so as to provide additional vehicle range without any modification to the existing battery materials. Such a large increase in range on an essentially cost neutral basis could be significant in the EV marketplace.
[0017] The inability of Li-ion batteries to accept high current for an extended period of time without experiencing unacceptable voltage responses is also relevant to regenerative braking efficiency. The energy capture efficiency from vehicle momentum is directly related to the ability of the battery to accept the energy at the currents provided during vehicle deceleration. It is this charged battery that, in turn, powers the vehicle's electric traction motor. In an all-electric vehicle, this motor is the sole source of locomotion. In a hybrid, the motor works in partnership with an internal combustion engine. However, this motor is not just a source of propulsion—it is also a generator. If a Li-ion battery could accept an increased charging rate while attaining higher SOC levels than possible today using conventional charging methods, energy capture would be greater and the battery would be charged more fully during driving. In short, the ability to apply a higher charging rate to a battery from each regenerative braking event could allow smaller gasoline-power motors to be used to provide required power to the vehicle, thus further improving emissions reductions seen with PHEV adoption.
[0018] There have been efforts to improve the charging behavior of Li-ion batteries given their importance to consumers today and in the future. Battery management systems and software algorithms, usually in combination with more advanced and expensive chargers, can allow some charging speed improvements. However, improvements to date have been only modest. For most applications, the charging speed increases achievable with use of conventional fast charging processes do not justify the added cost, complexity and battery damage that invariably result.
[0019] Some recently announced battery chemistries are reported to provide somewhat faster charging. However, these likely will not gain broad utility in the marketplace at least because modifications that enable faster charging generally reduce energy density. Researchers are also identifying new electrode configurations and the like that allow faster charging, but batteries containing these features are many years from being ready for the marketplace, if they ever are at all, due to the parallel need to fund, develop and validate corresponding production facilities and tools.
[0020] To summarize, the voltage behavior that results when constant current is applied to batteries at high rates negatively influences performance in a number of dimensions. A battery charging process that allowed high rate charging while at the same time substantially reducing attendant voltage response would improve Li-ion battery performance.
[0021] It would be highly desirable to obtain improvements in Li-ion battery charging without the requirement to modify the chemistry of the battery or without making other, often expensive and complex, modifications to the battery, device or vehicle. Still further, it would be desirable to be able to provide faster charging and less damaging charging of existing Li-ion batteries without causing battery damage seen with prior art fast charging methodologies.
[0022] The present invention provides these, as well as other, needed benefits.
SUMMARY OF THE INVENTION
[0023] The present invention comprises charging methodology that allows battery cells, such as Li-ion, to be charged using high effective charging rates during substantially the entire charging process. Still further, the present invention comprises methods and battery charging systems suitable for providing such charging methods wherein a plurality of charging pulses is applied to a battery at an average rate of at least about 1C or greater, wherein the plurality of instantaneous open circuit voltages (OCV inst ) existing during the charging process substantially remain below V max for substantially the entire duration of the charging pulse application. Unlike other methods of charging batteries at comparably high rates batteries charged according to the methodology herein are characterized by a substantial reduction of the characteristic voltage response that requires current to be reduced after the battery reaches higher % SOC. A wide variety of battery cells can be charged in accordance with methods and systems of the present invention including, but not limited to, batteries used to provide power for electric vehicles, automated guided vehicles, robots, mobile devices and wearable devices.
[0024] Still further, the plurality of voltage pulses applied to the battery cells in accordance with the invention herein comprises voltage pulses. The voltage pulse can further comprise an offset voltage, a duty cycle and a frequency. In further aspects, the present invention comprises battery charger systems configured to suitably provide the inventive charging pulses.
[0025] In addition to Li-ion cells of various types, the present invention also has application to a variety of batteries including alkaline, lead acid, nickel metal hydride, nickel cadmium and the like.
[0026] Additional advantages of the invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combination particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 illustrates a prior art CC/CV battery charging process applied to a 1000 mAh Li-ion mobile device type battery.
[0028] FIG. 2 illustrates an exemplary prior art DC fast charging process for the Tesla Motors® 85 kWh Model S, a current commercial electric vehicle.
[0029] FIGS. 3 a and 3 b are prior art exemplary equivalent circuit battery models from the literature that include models of battery internal impedance.
[0030] FIG. 4 includes three conceptual sketches, 4 a , 4 b , and 4 c (not to scale), of various aspects of charging frameworks according to the present invention.
[0031] FIG. 5 is an exemplary analog implementation of the inventive charging process.
[0032] FIG. 6 is an exemplary OCV estimation protocol in an analog implementation of the inventive charging process.
[0033] FIG. 7 is an exemplary offset voltage reference stage in an analog implementation of the inventive charging process.
[0034] FIG. 8 is an exemplary voltage summation stage in an analog implementation of the inventive charging process.
[0035] FIG. 9 is an exemplary voltage limiting stage in an analog implementation of the inventive charging process.
[0036] FIG. 10 is an exemplary power stage setup in an analog implementation of the inventive charging process.
[0037] FIG. 11 is an exemplary digital implementation of the inventive charging process.
[0038] FIG. 12 is a representation of the inventive charging process applied at 1C to a mobile device-type Li-ion “energy” battery.
[0039] FIG. 13 is a representation of the inventive charging process applied at 4C to a radio-controlled helicopter Li-ion “power” battery.
[0040] FIG. 14 presents a prophetic example of an estimated comparison of the inventive charging process in a commercial electric vehicle in comparison to a prior art DC fast charging process.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Many aspects of the disclosure can be better understood with reference to the drawings presented herewith. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. While several implementations are described in connection with these drawings, there is no intent to limit the disclosure to the implementations or implementations disclosed herein. To the contrary, the intent is to cover all alternatives, modifications, and equivalents.
[0042] The term “substantially” is meant to permit deviations from the descriptive term that do not negatively impact the intended purpose. All descriptive terms used herein are implicitly understood to be modified by the word substantially, even if the descriptive term is not explicitly modified by the word “substantially.”
[0043] “Battery” means an electrochemical battery or electrochemical cell. As would be appreciated by one of ordinary skill in the art, a battery is used to store energy for use in, for example, a device or vehicle. “Battery pack” is a group of individual electrochemical batteries or electrochemical cells arranged in series and/or in parallel. The words “battery” and “cell” may be used together or individually herein. The battery charging method and systems herein can suitably be used to charge battery packs.
[0044] “Battery charger system” means a device, apparatus or method for providing electrical energy to a battery cell and/or pack for storage and use at a later time by a device or vehicle configured to be powered by such Li-ion battery cells and/or packs. The battery charger system of the present invention can comprise one or more implementations as discussed herein. The battery charger systems of the present invention can also comprise any suitable configuration (e.g., analog, microprocessor controlled, etc.) that will allow the charging processes of the present invention to be suitably conducted.
[0045] “State of charge” (“SOC”) is a fraction calculated as the amount of charge in the battery at a particular time divided by the maximum amount of charge that the battery can store. SOC is typically indicated as a percentage.
[0046] “Open circuit voltage” (“OCV”) means the electrical potential between two terminals of a battery when disconnected from any external circuit.
[0047] “OCV eq ” means the equilibrium open circuit voltage. As is known by those of ordinary skill in the art, the OCV eq depends substantially on SOC. The OCV of a battery during charge or discharge deviates from OCV eq due to the effects of cell polarization. When charging or discharging ceases, the OCV measured for the battery changes over time and converges to a long-term value, OCV eq , as polarization dissipates.
[0048] OCV inst is an instantaneous value measured for OCV. Generally, if OCV inst is measured a short time after charging or discharging has ceased, then OCV inst ≠OCV eq . During application of the inventive charging pulses, OCV inst will vary, as least in relation to % SOC. As such, each charging process will comprise a plurality of OCV inst .
[0049] Battery impedance (“Z Batt ”) means that aspect of a battery that behaves as an electrical impedance in series with an ideal voltage source whose output voltage is OCV eq as defined herein below. This battery impedance comprises the Thevenin equivalent impedance of the battery modeled as an electrical component and arises from internal components of the battery, in particular, from the materials of construction of the battery and the physical configuration of such materials in the battery. The impedance may be modeled as a battery series resistance and a battery complex impedance network, as diagrammed in FIG. 3 a.
[0050] The battery series resistance (“R s ”) comprises the part of the battery impedance that behaves as a resistance in series with, and not parallel to, any reactive components of the battery impedance (such as equivalent capacitances or inductances). This resistance is comprised principally of the resistances of physical components and particles that make up the battery, the contact resistances between the components or particles, and the electrolyte resistance. The battery series resistance is one of several battery characterization parameters that battery manufacturers may supply to producers integrating batteries into end-item products and can be determined by one of ordinary skill in the art according to known methods.
[0051] As known, and as represented by the exemplary battery models of FIGS. 3 a and 3 b , a battery also comprises a number of capacitive features that reside in a complex impedance network topologically in series between the battery series resistance and the Thevinen equivalent ideal voltage source. These capacitive features comprise, for example, the double layer capacitances, C dl , formed at the interface between the electrolyte and the electrodes and a pseudocapacitance, C φ , that arise due to a time-varying, non-linear functional relationship between applied voltage and state of charge during the battery charging process. Still further, the inventors herein understand, not wishing to be bound by theory, that the capacitances of a battery under charge can be somewhat substantial as discussed elsewhere herein.
[0052] “Battery current” (“I Batt ”) is the electrical current flowing through the battery. When describing battery charging processes, positive values of I Batt correspond to net electrical current flowing into the positive terminal of the battery, so as to reflect positive progress in the charging process, and negative values of I Batt correspond to net electrical current flowing out of the positive terminal of the battery, as would occur in battery discharge events.
[0053] If battery current changes or varies during the window of time of a particular process, the battery process average current, I BattPavg , is the average of battery current across the time window of the entire process. If a battery current varies and the variation has a periodic component, the battery cycle average current, I BattCavg , is the average of battery current across the time window of one cycle of periodicity. If the battery current also has a component of variation that is not periodic, the battery cycle average current may vary from cycle-to-cycle.
[0054] “V max ” means an upper limit specified for the maximum voltage to apply to a battery under charge. Battery designers specify V max by taking into account battery chemistry, the details of construction, the likely charge/discharge regime in use and the consequences of failure. For example, in a typical lithium ion battery used in mobile electronic products (also termed an “energy battery” or “energy cell”), the generally recognized V max , is about 4.3 V or less for constant current/constant voltage charging, and more commonly 4.2 V. V max , is defined for each specific battery chemistry and construction in accordance with methodologies well-known to those of skill in the art. The value of V max can be determined according to battery supplier specifications, regulations and standards, and other product development considerations. Determination of V max is not a part of this invention.
[0055] Under charging conditions: V Batt >OCV inst and the incremental voltage of V Batt above OCV is commonly referred to as “overvoltage.”
[0056] “Charging pulse” means any pulse of current or voltage of any shape applied across the battery terminals. A charging pulse has a “pulse period” comprising an “ON-time,” also known as a “pulse width,” during which current is supplied to the battery to increase the SOC, and an “OFF-time,” during which no current is supplied to the battery and the external circuit may present substantially the nature of an open circuit to the battery. The charging pulse may also be characterized in terms of “duty cycle.” “Duty cycle” is the fraction of time that a system is in an “active” state. For example, in an ideal pulse train (one having rectangular pulses), the duty cycle is the pulse width divided by the pulse period. For a pulse train in which the pulse width is 1 μs and the pulse period is 4 μs, the duty cycle is 0.25. The duty cycle of a square wave is 0.5, or 50%.
[0057] “Offset voltage” is the incremental amount of voltage applied to the battery in accordance with the inventive charging methods herein. Offset voltage is illustrated, for example, in FIGS. 4 a , 4 b and 4 c , as well as the Examples hereinafter.
[0058] The “charging pulse frequency” is the reciprocal of the charging pulse period.
[0059] A battery “voltage peak” is the portion of a charging pulse associated with ON-time during which the battery voltage is substantially at the maximum voltage level attained during that ON-time. The “peak voltage” is the maximum voltage level attained during a voltage peak.
[0060] A battery voltage “trough” is the portion of a charging pulse associated with OFF-time during which the battery voltage is substantially at the minimum voltage level attained during that OFF-time and at which time the external battery charging circuit is presenting to the battery the nature of an open circuit.
[0061] In broad terms, the present invention comprises charging methodologies and systems incorporating such charging methodologies that allow electrochemical cells such as Li-ion and other cell types to be charged using high effective charging rates during substantially the entire charging process. Still further, the present invention comprises methods and battery charging systems suitable for providing such charging methods wherein a plurality of charging pulses are applied to a battery at an average rate of at least about 1C or greater for substantially the entire charging process, wherein OCV inst remains below V max for substantially the entire duration of the charging pulse application.
[0062] Unlike other methods of charging Li-ion batteries at comparably high rates, batteries charged according to the methodology herein can be characterized by a substantial reduction of the characteristic voltage response seen when charging Li-ion batteries at high rates as compared to prior art constant current charging methodologies. The unique and beneficial voltage response of batteries charged in accordance with the present invention permits charging of Li-ion batteries to significant % SOC in 1 hour or less. In further aspects, the present invention comprises a charging methodology and systems incorporating such charging methodology that allows charging of batteries at 1C or greater to a % SOC of at least about 80%, or at least about 85%, or at least about 90% or at least about 95% or up to about 100%, substantially without need for application of a constant voltage portion.
[0063] In some aspects, the inventive charging methodology comprises a charging pulse. Still further, the charging pulse of the present invention comprises a voltage pulse. The charging pulse of the present invention can consist essentially of a voltage pulse. Yet further, the voltage pulse of the present invention comprises one or more of an offset voltage, a frequency and a duty cycle as set forth in more detail herein. Still further, the voltage pulse of the present invention consists essentially of a voltage pulse. The voltage pulse of the present invention can further consist essentially of an offset voltage, a frequency and a duty cycle.
[0064] As would be understood by those of ordinary skill in the art, battery capacity, C, can be expressed in Amp-hours (Ah) or milliamp-hours (mAh). Battery charging rate (C-rate) is often described in normalized units of capacity per hour. For example, a 1000 mAh battery charging with a charging current of 1000 mA (or 1 A) would be charging at a C rate of 1C. For a 100 mAh capacity battery, the current corresponding to 1C is 100 mA (or 0.1 A). The present invention supports charging of Li-ion battery cells at effective C rates of at least about 1C or at least about 1.5C or at least about 2.0C or at least about 2.5C or at least about 3.0C or at least about 3.5C or at least about 4.0C or at least about 4.5C or at least about 5.0C or greater substantially without the battery experiencing deleterious effects normally expected from prior art fast charging processes. Such deleterious effects include, but are not limited to, voltage rise greater than V max , side reactions, unacceptable temperature increases or even fires.
[0065] As would be recognized by those of skill in the art, the characteristic voltage behavior occurring in Li-ion batteries resulting from application of high constant charging current requires the current to be greatly reduced during the later stages of charging or even be terminated to keep the battery voltage from exceeding V max . A typical prior art voltage response of a 1000 mAh mobile device battery—that is, an “energy” battery—is shown in FIG. 1 . If the battery charging process is terminated due to the battery voltage attaining V max , the % SOC of the battery will remain below the available capacity of the battery. In FIG. 1 , application of a 1C charge rate results in about 60% SOC in about 36 minutes (or 0.6 hour). At about 36 minutes, the current decreases and the rate of increase of % SOC similarly declines. At about 1 hour, the battery only has about 80% SOC vs. the 100% SOC if the rate had continued at 1C for the entire 60 minutes. As seen in FIG. 1 , to achieve the full 100% SOC of this battery, the battery must remain connected to the charger for close to 3 hours.
[0066] The characteristic voltage response from an exemplary prior art high rate Li-ion battery charging of EV batteries is shown in FIG. 2 . In this representation of the charging process of a Model S 85 kWh battery having a reported 300 mile range as reported by Tesla Motors (http://teslamotors/supercharger), one sees that 20 minutes of high rate charging will provide 150 miles of range (i.e., 50% SOC). This amounts to an about 1.5C charging rate. However, a charge time of 40 minutes is required to attain 240 miles (i.e., 30% more SOC), signifying that the charging rate between 20 and 40 minutes decreases to an average of about 0.9C. It takes an additional 35 minutes to acquire the final 20% SOC—that is, to achieve the full 300 mile range for the 85 kWh Model S—which means that the C rate for this last charging stage slows to an average C rate of about 0.34C.
[0067] As should be apparent from the data presented for the prior art charging processes in FIGS. 1 and 2 , in order to achieve a faster overall charging process, the user must accept a lower available battery capacity, and thus a shorter run time for the device or vehicle being powered by that battery. In other words, to employ a constant high charging rate, the user is required to forego using a portion of the full storage capacity available in the battery. In contrast, if a constant voltage step is applied after the constant current step, more of the available capacity of the battery can be utilized, allowing longer runtime available for the device or vehicle. However, to obtain this full capacity after an initial constant current charging process, the user must accept a longer charging time. Conventional battery charging therefore requires a trade-off between charging time and battery capacity. Such a trade-off is substantially not required with the charging processes of the present invention.
[0068] A wide variety of Li-ion battery cells can be charged in accordance with the methods and systems of the present invention including, but not limited to, batteries and battery packs used to provide power for electric vehicles, automated guided vehicles, robots, mobile devices and wearable devices.
[0069] In applying current for charging in accordance with the methodology of the present invention, the appropriate C rate in a particular instance will depend, in part, on the Li-ion battery being charged. For example, for “energy” batteries—that is, those batteries intended for use in mobile and similar devices—conventional constant current processes maintained at over about 1C gives rise to significant possibility battery failure, either immediately or over continued use. Such “energy” batteries are typically lithium cobalt oxide chemistry, and can be the form of 18650 cells or configured in soft packs. For such batteries, the inventive battery charging process allows the batteries to be charged at an effective charging rate of least about 1C for substantially all of the duration of the charging process, and beyond the point where the voltage of the battery would exceed acceptable levels in prior art charging methodologies. Still further, with lithium cobalt oxide “energy” batteries, the effective charging rate can be at least about 1C, 1.25C, 1.5C, 1.75C or 2C or more for substantially the entire duration of the charging process, where the OCV inst remains substantially below V max for all or substantially all of the charging process. This is in contrast to prior art charging methods in which application of a constant current charge at a rate of about 1C or greater results in battery OCV inst approaching the V max of the cell at about 60 to 70% SOC. It has surprisingly been found that lithium cobalt oxide cells charged in accordance with the inventive voltage pulse can be charged at a much higher effective C rates without experiencing the heat or voltage increases that are recognized as damaging or dangerous and that prevent these cells from being charged at high C rates unless comprehensive cooling and fireproofing systems are used. One example of such cooling and fireproofing systems is disclosed in U.S. Pat. No. 8,263,250 (assigned to Tesla Motors), the disclosure of which is incorporated herein in its entirety by this reference.
[0070] In “power” batteries—that is, those Li-ion batteries intended for use in EVs, robots, power tools and the like—higher C rates can be applied both using conventional constant current processes and with the inventive pulse charging method. These batteries include lithium iron phosphate and the like. For such batteries, the inventive battery charging process nonetheless allows the batteries to be charged at even higher effective rates to achieve higher % SOC than possible with prior art constant current charging processes. In particular, the inventive charging process allows charging of at least about 1C for substantially all of the duration of the charging process. Still further, with Li-ion “power” batteries, the effective charging rate can be at least about 1C, 1.25C, 1.5C, 1.75C, 2C, 2C, 2.5C, 2.5C, 2.75C, 3C, 3.25C, 3.5C, 3.75C or 4C or more for substantially the entire duration of the charging process, where the battery voltage remains substantially below V max , for all or most of the charging process. This is in contrast to prior art charging methods in which application of constant current at a rate of at least about 1C to 1.5C or even greater results in a voltage response that requires reduction in the current applied to the battery, as is illustrated in FIG. 2 , for example.
[0071] An aspect of the present invention relates to the characteristics of the charging pulse applied to the battery. In this regard, the charging pulse applied to the battery during the charging process comprises a plurality of voltage pulses whose application results in the inducement of a battery current pulse as a response to the voltage pulse. Yet further, the charging pulse applied to the battery does not comprise a current pulse of controlled current magnitude that is imposed upon the battery independently of battery voltage. Yet still further, the charging pulse applied to the battery substantially does not switch to a current pulse.
[0072] In another aspect of the charging method of the present invention, when the battery charger system is not transferring energy to the battery, any voltage reading at the battery terminals would be a representation of the open cell potential measured in real time, in other words, the nature of an open circuit would be presented to the battery. In one aspect, such real time voltage measurement is incorporated in the invention herein as OCV inst .
[0073] As used herein, the OCV inst typically differs from equilibrium OCV (“OCV eq ”), where the latter results by allowing the battery to relax for some time after application of charging pulse is stopped. OCV eq is understood to be generally synonymous with the complete or substantially complete relaxation of transient or non-equilibrium conditions within a battery. An example of a non-equilibrium state would be the presence of a transient concentration gradient in the electrolyte. Reports of the time required to achieve OCV eq vary substantially in the literature, however, it is generally believed that relaxation takes at least seconds, or minutes or even hours to achieve for various battery types.
[0074] Still further, it has been found that the beneficial properties of the charging methodology of the present invention can be achieved by applying an offset voltage during the charging process without actual measurement of OCV inst In other words, a constant or substantially constant offset voltage can be applied to the battery during all or substantially all of the charging process, as long as the battery charger system applies a suitable charging pulse to the battery. While measurement of the OCV inst and applying an offset voltage in response to each measured OCV inst can provide the ability to achieve the benefits of the inventive charging process, the ability to substantially achieve the inventive charging benefits without the need to implement expensive power electronics controls potentially can improve the applicability of the present invention to lower costs applications, such as consumer products.
[0075] Whether applied in relation to determination of the OCV inst or otherwise, the offset voltage can be kept constant for the entire charging process, or it can be varied. In some aspects, the offset voltage can be about 50 mV, 75 mV, 100 mV, 150 mV, 200 mV, 250 mV, 300 mV, 350 mV, 400 mV, 450 mV, 500 mV, 550 mV, 600 mV, 650 mV or 700 mV greater than the OCV inst while the battery is undergoing charge, where any value can form an upper or lower endpoint as appropriate.
[0076] Still further, the offset voltage can comprise any voltage that, when applied in the form of a plurality of charging pulses as described herein, results in the ability to apply a high charging rate (e.g., 1C or greater) to the battery to allow the voltage to rise in a linear or nearly linear fashion. Still further, the offset voltage can comprise any voltage that, when applied in the form of a charging pulse as described herein, results in the ability to apply a high charging rate to be applied to the battery in a constant rate to achieve at least about 80%, or 85% or 90% or 95% or up to about 100% SOC with the OCV inst substantially remaining below V max for substantially the entire charging process. In other aspects, the offset voltage can comprise any voltage that, when applied in the form of a charging pulse as described herein, results in the ability to apply a high charging rate substantially without resulting in the characteristic voltage response requiring application of a constant voltage portion.
[0077] A further characteristic of the charging pulse of the present invention relates to the duty cycle. In this regard, the duty cycle can be substantially constant within all or substantially all of a pulse sequence or plurality of pulse sequences that make up a charging operation according to the present invention. In some aspects, the duty cycle of the voltage pulse can be about 99, or 95 or 90 or 85 or 80 or 75 or 70 or 65 or 60 or 55 or 50%, where any value can comprise an upper or lower endpoint as appropriate.
[0078] Still further, the duty cycle of the voltage pulses can vary within all, substantially all or during of the charging operation in accordance with the present invention. In a further aspect of the present invention, the duty cycle of each of the charging pulses applied to the battery substantially do not vary during substantially all of the charging process. In a further aspect, the duty cycle of the plurality of charging pulses applied to the battery each, independently, do not vary more than about 1% or 5% or 10% or 15 or 20% during all or substantially all of an entire charging process. In yet a further aspect, there is substantially no pulse width modulation applied to the battery terminals during all or a substantial portion of a charging process. However, one could use pulse width modulation internal to the charger to achieve the voltage(s) applied to the battery terminals during pulse ON-times; i.e., use “very-fine” pulses of a switchmode circuit to construct the broader charging pulses of invention, whose widths, while broader than those of the switchmode circuit, are substantially not determined through pulse width modulation. In some aspects, use of such a switchmode charger could be more power-efficient, and thus be particularly suitable in some applications. Such regulation may not be needed for some applications because a voltage offset pulse can suitably be applied without fine measurement of the real time behavior of the battery under charge.
[0079] A further characteristic of the charging pulse of the present invention is frequency. While the frequency may vary depending on the other variables relevant to the charging process of the present invention (e.g., offset voltage and duty cycle), it has been found that periods of less than about 200 or 100 or 50 ms can be particularly suitable to achieve the beneficial effects of the present invention. In particular, the period of the voltage pulse can be equal to or less than about 200 or 100 or 50 or 40 or 30 or 20 or 10 or 1 or 0.1 ms, where any value can form an upper or lower endpoint, as appropriate. The frequency of the inventive voltage pulse can be represented in Hz. In this regard, the frequency of the voltage pulses that make up the plurality of voltage pulses can also be from about 1 to about 200 Hz. Yet further, the frequency of the voltage pulses can be about 1, 5, 10, 25, 50, 75, 100, 125, 150, 175 or 200 Hz, where any value can form an upper or lower endpoint, as appropriate. Still further, the frequency of the voltage pulses can be less than 50 Hz or less than 25 Hz.
[0080] In a further aspect, the inventive battery charging process can be voltage regulated with respect to the battery's OCV inst for all or substantially all of an application of a plurality of charging pulses, where such plurality of charging pulses is used in a process of charging a battery or a battery pack. This is in contrast to prior art voltage regulated pulse charging processes that are regulated with respect to battery V max . Such processes are generally current limited and do not provide much improvement in charging rates because, for example, the application of high charging currents in accordance with prior art processes quickly results in V max being reached or exceeded which, in turn, means that the charging rate must be reduced before the battery cell attains sufficient % SOC.
[0081] As currently understood by the inventors herein, the beneficial features of the charging process of the present invention, at least in part, relates to the unique voltage response of the battery undergoing charge from application of the plurality of charging pulses in accordance with the present invention. This voltage response is believed to result in little to no formation of “overpotential” as such term is defined in U.S. Pat. No. 8,368,357, the disclosure of which is incorporated herein in its entirety by this reference. The absence or substantial reduction of a voltage response resulting from application of a charging signal means that the method herein substantially does not require the calculation of an “overpotential” as defined in the '357 patent, and adaption of the charging process in response to such measurement. In contrast, in some aspects, the present invention operates to apply to the battery an optimum or substantially optimum amount of offset voltage necessary to induce as a result the efficient and effective charge transfer through and among the various components of a battery as appropriate for each battery in real time.
[0082] Existing pulse charging methods, such as that of the '357 patent and those of U.S. Pat. No. 5,694,023 (Podrazhansky et al.) and U.S. Pat. No. 6,040,685 (Tsenter et al.), each of which are incorporated herein in their entireties by this reference, seek to impart charge as quickly as possible before the battery exhibits adverse effects that require dramatic subsequent reduction of charging rate. To accomplish this, prior art methods define various algorithms and/or apply various battery management regimens to minimize adverse effects resulting from charging while also seeking to extract improved charging speeds. The '357 patent asserts that it represents an improvement over prior art methods by recognizing the benefits of controlling overpotential that includes closely monitoring the behavior of the battery during charging. Rather than pre-defining the pulse charging sequence to be applied (see for example, the Podrazhansky '023 patent), the '357 patent seeks to adjust the pulse charging sequence of a battery during charge. The '357 patent method therefore describes “on the fly” modification of a pulse charging sequence based upon calculation of an overvoltage in real time, where the overpotential is an adverse consequence of the pulse charging process applied therein, where such overpotential is defined by reference to the battery's V max .
[0083] In contrast, in significant aspects, the method of the present invention operates by referencing the real time voltage of the battery while being charged during application of the inventive charging process herein. An incremental voltage that is “just enough” over this real-time voltage is applied so that minimum “overpotential” (as such term is defined in the '357 patent) is developed.
[0084] How much offset voltage is just enough to provide the beneficial results from the inventive charging process can be determined a priori in designing a battery charger system in accordance with the present invention such as by using information from equivalent circuit models of a subject battery, or can be determined through use of dynamic feedback of measured battery current, I Batt or measured battery cycle average current, I BattCavg . Still further, the amount of offset voltage needed to achieve the benefits of the present invention can be determined experimentally by varying the various parameters relevant to the inventive charging method (e.g., offset voltage, pulse frequency and duty cycle) for a battery cell, pack or system using methods know to those of skill in the art. Yet further, the appropriate offset voltage level can be determined by estimation from measurement of battery terminal voltage during application of the plurality of charging pulses.
[0085] A battery can be modeled using an equivalent circuit comprising standard electrical features. One example of a prior art battery equivalent circuit is shown in FIG. 3A . A second example of a battery equivalent circuit is found in FIG. 3B . The inventors herein have found that the equivalent circuit models of FIGS. 3A and 3B can be used in simulations of the present invention virtually interchangeably, albeit with adjustments to equivalent circuit parameter values to yield approximately similar overall impedance characteristics. Without being bound by theory, and in certain aspects, the inventors hypothesize that the beneficial aspects of the present invention result, at least in part, from leveraging a battery's series resistance and equivalent circuit to influence charging behavior. Unlike the OCV, the series resistance behavior of the battery does not change as substantially as a function of the state of charge for much of the useful range of % SOC, that is, above about 5% or about 10% or about 15% or about 20% or about 25% SOC.
[0086] The series resistance of a battery is a property of each specific battery type and design. This value is a known or knowable feature of each battery type. This value is typically provided to battery end-use product integrators/producers by the manufacturer for a specific battery design or even for a specific lot of batteries. If not supplied by the manufacturer, the series resistance of a battery is readily determinable by one of ordinary skill in the art without undue experimentation.
[0087] As known, and as represented by the exemplary battery models of FIGS. 3A and 3B , a battery also comprises a number of capacitive features. These capacitive features comprise, for example, the double layer capacitances formed at the interface between the electrolyte and the electrodes and a pseudocapacitance that arises due to a non-constant functional relationship between applied voltage and state of charge during the battery charging process. Still further, the inventors herein understand, not wishing to be bound by theory, that the capacitances of a battery under charge can be somewhat substantial. In some aspects, the capacitances of a battery under charge can be at least about 1F, 1.5F, 2F, 2.5F, 3F, 3.5F, 4F, or 5F or even as large as 25F in some circumstances. In accordance with the pulse charging processes of the present invention, the inventors herein believe that the dissipation of charge from at least some of the capacitive features present in a battery can be very fast (e.g., as low as 20 μs) in the substantial absence of an applied charging pulse. In other words, the inventors have found that application of short duration charging pulses, for example the incremental voltage pulses discussed herein, can impart charge to a battery for storage substantially without also resulting in creation of substantial overvoltage, where such overvoltage is believed to be created in whole or in part by charging of one or more of the capacitive features of a battery. Additionally, the inventors have recognized that the more residual charge remaining on the battery capacitances during a charging process, the more overvoltage will remain in the battery.
[0088] In accordance with one aspect of the present invention, the OFF-times substantially allow at least a portion of the capacitive features in the battery to dissipate their accumulated charge(s) at least in part prior to application of a subsequent charging pulse. The inventors hypothesize that the dissipation of accumulated charge during OFF-times is a contributor to the absence or substantial reduction of overvoltage in one or a plurality of charging pulse applications
[0089] In some aspects, by focusing on charging by applying the lowest amount of charging pulse energy needed to impart a suitable charge for a particular battery cell and/or pack, the inventive battery charging process seeks to leverage existing battery internal capacitive features to absorb charging current, while at the same time effectively reducing or eliminating overvoltage-related resistance to charge.
[0090] In a feature of the inventive process, a substantially low level of charging of the capacitive features of the battery occurs during application of a single charging pulse. Moreover, the present invention results in a substantially low level of capacitive charging during application of a plurality of charging pulses. It has been discovered by the inventors herein that with this minimum of charging of the capacitive features, a minimum amount of energy will generally be needed to charge the battery effectively and efficiently. Faster overall charging can also occur without substantially without incurring increased temperatures and voltage spikes as compared to prior art charging methodologies. Moreover, long term battery behavior can be improved, such as in less capacity fade over extended use.
[0091] In a relevant aspect of the present invention, when the capacitive features of the battery are kept substantially uncharged or, at least, less fully charged than in other rapid or pulse charging methodologies, battery charging can effectively and efficiently result when an applied voltage is sufficient to address the series resistance so that a suitably high average current can be applied to the battery substantially without causing the deleterious effects generally expected from fast charging processes.
[0092] In the battery charging process of the present invention, as well as with the attendant battery charging systems, the charging pulse applied to charge the battery can be, in some aspects, characterized as substantially the minimum offset voltage needed to overcome the potential existing in real time.
[0093] Suitable operation of the inventive battery charging processes herein generally does not necessitate knowledge of the exact value of R s . As such, I BattCavg in the present invention can comprise the desired cycle average current applied during the ON-time and, accordingly, can be used to approximate the actual instantaneous current, if the charger implementation already measures I BattCavg as a process control variable. I BattCavg can also be estimated from I Batt , if the charger implementation already measures instantaneous current as part of transient process control, as such controls are known to one of ordinary skill in the art. Use of a priori knowledge of R s is only one potential means of reducing charger circuit hardware cost by marginalizing the need for current sensing hardware.
[0094] In further aspects, the voltage applied to the battery in the plurality of charging pulses can comprise an instantaneous terminal voltage applied to the battery (V Batt ) and can be calculated according to the following formula.
[0000] V Batt =I Batt ×R s +OCV inst
[0000] and
[0000] I Batt =I BattCavg ×(pulse period)/(ON-time duration),
[0095] wherein the desired [instantaneous] battery current, I Batt , is derived from the battery cycle average current, I BattCavg , desired for a particular portion of an overall charging process, R s is internal series resistance as discussed previously, and OCV inst is the instantaneous OCV existing in the battery in real time, also as defined previously. In one aspect of the present invention, OCV inst can be measured, sensed, estimated or otherwise determined at one or more times, during each of a plurality of OFF-times. OCV inst will generally be lowest (and more informative) at or near the end of the respective OFF-times—that is, at or near the end of the trough portion of the applied voltage pulses. As such, when OCV inst can be measured, sensed, or otherwise determined in the OFF-time, it may be sufficient to acquire information about OCV inst only one time during the OFF-time, namely, where such one time is at or near the end of the OFF-time.
[0096] The inventive charging processes can also be suitably obtained by using either instantaneous or cycle average current (or approximation of cycle average current) as a feedback signal to control a voltage source that applies during ON-times the proper voltage to induce the desired instantaneous current subject to the battery charging voltage limitation. In some aspects, use of such dynamic feedback can provide more consistent delivery of cycle average current and incorporation of such capability can be beneficial when the additional cost and package space of incorporating current feedback is appropriate for certain applications.
[0097] Regardless of whether an application designer chooses to use OFF-time OCV inst estimation and a fixed incremental offset voltage or to use on-time dynamic feedback of battery current information, the periodic OFF-time duration of the inventive voltage pulse can be substantially uniform through the charging process or it can be designed to vary. The duration of the OFF-time can be from about 10 μs to about 10 ms. In some aspects, the duration of the OFF-time can be from about 0.1, 0.5, 1, 2, 5, 7, or about 10 ms.
[0098] Optimal ON-time will vary according to battery characteristics. In general, however, longer ON-times could be found to result in greater charge accumulations within the capacitances of the battery internal impedances, and thus higher V res levels; shorter ON-times, however, may generally necessitate the use of greater ON-time voltages to achieve greater instantaneous currents in the shorter ON-time. Longer OFF-times may reduce induced current cycle averages (and overall charging rate); while shorter OFF-times may interrupt the opportunities for charge to dissipate from the battery internal impedances.
[0099] The inventors have found the inventive charging processes herein to be generally applicable for pulses whose overall periods range from about 100 μs to about 100 ms and whose ON-time duty cycles range from about 50% to about 90%. Still further, the duty cycles of the voltage pulse of the present invention can comprise from about 50, 55, 60, 65, 70, 75, 80, 85, or 90%, where any value can comprise an upper or lower endpoint, as appropriate. Selection of pulse period and corresponding ON-time duty cycle may generally be dependent upon battery characteristics, the desired charging rate, and allowable battery thermal power dissipation rate and is thus dependent, in part, upon the battery and the application in which the battery is to be used.
[0100] As would be recognized by those of ordinary skill in the art, Li-ion battery voltage progressively increases as the SOC increases within the range of 0% to 100%. At some point during the charging process of the present invention, the sum of the battery OCV inst and the offset voltage reference could exceed V max . It has been found that as long that the OCV inst during the OFF-time voltage trough remains below V max , the beneficial effects of the present invention can still be obtained, including improvement of times needed to achieve high % SOC. A not-to-scale exemplary representation of the voltage and current behavior using a fixed incremental voltage pulse in this is illustrated in FIG. 4 a . An implicit aspect of this finding is that the charging process of the inventive method can be terminated when the OCV inst during the OFF-time voltage trough reaches V max .
[0101] In some aspects, the fast charge stage of the inventive method can be terminated or restricted when the measured voltage pulse to be applied substantially reaches V max for the respective battery. If the charge is restricted, the charging rate will be slower than if the charging process is permitted to proceed without restriction, however, charging rates will still exceed those attainable with conventional CC/CV charging. In accordance with this aspect, the voltage applied substantially does not exceed the specified V max of the battery under charge. A not-to-scale exemplary representation of the voltage and current behavior using feedback of I Batt or I BattCavg to adjust incremental voltage is illustrated in FIG. 4 b.
[0102] In separate aspects, the inventive charging pulse can be terminated or restricted when the battery has reached at least about 60% or about 70% or about 75% or about 80% or about 85% or about 90% SOC. At this point, a voltage limited stage can commence if desired as a form of restricted continuation of charging. Such a voltage-limited stage can be omitted and the battery process terminated if it is deemed suitable to use the battery that is less than about 100% SOC. A partial application of the inventive charging pulse with or without a subsequent constant voltage stage could be desirable to reduce battery damage over time in comparison to that seen from application of a prior art constant current charging. In laymen's terms, the inventive charging process can be termed a “kinder and gentler” charging process.
[0103] One can use any of a myriad of pulse shapes to provide features of the inventive charging pulse of the present invention. It should be noted that since dissipated power is proportional to the square of offset voltage but only proportional to the width of a pulse, minimization of dissipated parasitic power means minimization of RMS pulse height across any given pulse period. For the same cycle average current I BattCavg within a pulse period, the minimum RMS pulse height can be achieved with application of a rectangular pulse of the maximum allowable ON-time width. In some aspects, appropriate pulse shapes comprise those that suitably provide an offset voltage beyond OCV inst during the ON-time that is less than the target value. In further aspects, constant voltage pulses are particularly suitable for use herein. A not-to-scale exemplary representation of the voltage and current behavior for a non-rectangular/square pulse shape is illustrated in FIG. 4 c.
[0104] In one aspect, the charging process can be terminated by applying a limit to sensed average current and average voltage and not to the instantaneous current and instantaneous voltage. Any of a number of methods exist and are appropriate for determining the time to terminate the charging process, so determining time to terminate the charging process and terminating the process are known to those of ordinary skill in the art. Similarly, methods for sensing average current and average voltage are known and consequently are known to those of ordinary skill in the art.
[0105] Throughout the fast charging stage and voltage limited charging stage, each charging pulse maximum voltage during an ON-time can be a function of a charge increment strategy and the battery terminal voltage during a preceding OFF-time can be subject to a maximum voltage limitation. Accordingly, the battery charger of the present invention, as well as the processes used for charging, can, in some aspects, be dynamically dependent upon period-to-period feedback from the battery.
[0106] At low % SOC the R s may change quickly. In some aspects, at low % SOC, for example, less than about 20% or less than about 10% SOC, it could be helpful to closely monitor the series resistance behavior to ensure that the amount of offset voltage applied to the battery under charge is as close as possible to the minimum amount necessary to effect efficient charge. Such monitoring can be in accordance with known methods as would be known to one of ordinary skill in the art. In some implementations, monitoring of series resistance can be useful during all or part of the charging process.
[0107] Yet further, in the inventive charging methods there may be substantially no need to change modes such as by moving from average current charging to average voltage charging, because, in some aspects, the present invention can automatically limit the target battery terminal voltage as appropriate to yield the target battery terminal voltage.
[0108] The charging processes and systems incorporating such processes are applicable to a wide variety of Li-ion batteries including lithium cobalt oxide, lithium manganese dioxide, lithium iron phosphate, and lithium iron disulfide etc. It should be noted that some fast charging Li-ion chemistries do exist today. For example, lithium titanate is reported to allow charging as fast as 10C. Such fast charging batteries nonetheless result in lower energy densities. In other words, they do not provide as energy per unit of weight as do other Li-ion battery types.
[0109] As would be recognized by one of ordinary skill in the art, the operating voltage characteristics of a particular Li-ion cell will be a function of the anode and cathode materials combined to form the cell. For example, the reported voltage for a lithium cobalt oxide cell comprising a carbon anode is about 3.8 V, but for a cell comprising lithium titanate as the anode, the nominal operating voltage is about 2.4V. The higher voltage of the lithium cobalt oxide cell brings higher energy density, but fewer safety features—including lesser ability to accept faster charging. In contrast, cells with lower operating voltage like lithium titanate have better safety features, such as safer fast charging. Generally speaking, Li-ion “power” batteries have lower operating voltages and can accept prior art charges at higher rates, such as greater than about 2C for at least some of the charging process. Li-ion “energy” batteries have higher operating voltages and are generally not charged for extended periods at rate above about 1C unless safety and cooling systems are included, such as those disclosed in U.S. Pat. No. 8,263,250, previously incorporated by reference.
[0110] In the present invention, it has surprisingly been found that safe and generally non-damaging fast charging can be applied to Li-ion batteries having operating voltages of greater than about 3.0 V, or greater than about 3.2 V. Such batteries include, for example, lithium iron phosphate/graphite (≈3.2 V), lithium manganese oxide/graphite (≈3.7 V), lithium nickel cobalt aluminum oxide/graphite (≈3.6 V), lithium nickel manganese cobalt oxide/graphite (≈3.65 V or more) and lithium cobalt oxide/graphite (≈3.8 V). In further aspects, the present invention does not include lithium titanate and similar Li-ion battery chemistries having operating voltages of less than about 3.0 V or less than about 3.2 V.
[0111] In regard to types of secondary batteries other than Li-ion, such batteries comprise capacitive features. As such, a charging pulse that is applied in relation to OCV inst is suitable for use with a wide variety of battery types. While much of the disclosure herein, including exemplary implementations and data, is presented in the context of circuitry or techniques applicable to a Li-ion technology/chemistry based battery/cells, the battery charging processes set out herein can also be suitably implemented in conjunction with other electrochemical cell chemistries including, for example, nickel-cadmium, nickel metal hydride, alkaline and lead acid. As such, the aspects herein discussed in relation to Li-ion based batteries/cells/packs are exemplary only.
[0112] The battery charger systems of the present invention, as well as the attendant processes and methods, can be utilized in conjunction with one or more existing battery management systems. Such battery management systems, which generally utilize integrated circuitry to control power management during battery charging, are commonly incorporated in modern electronic devices and other products that are powered by batteries.
[0113] Moreover, the present invention can be utilized with, or operationally incorporated within, one or more adaptive battery charging techniques. Such adaptive methods are disclosed, for examples, in U.S. Pat. No. 8,638,070, the disclosure of which is incorporated herein in its entirety.
[0114] An overall charging system and process can include the invented charger and method in conjunction with higher-level charging system process controls. FIG. 5 is a block diagram of an exemplary analog implementation of an inventive battery charger system with interface points for supervisory charging system process controls, but does not show the details of the higher-level process controls, as they do not comprise part of the present invention.
[0115] For example, as shown in FIG. 5 , a battery charger 10 according to the present invention for suitably charging battery 50 can include about five internal functional subsystems: OCV estimation/sample 100 , offset voltage reference 200 , voltage summation 300 , target battery voltage limitation 400 and power stage 500 , each of which may or may not be implemented as discrete physical entities, depending upon economic and space considerations.
[0116] FIG. 6 illustrates a suitable implementation of the OCV inst estimation or sampling subsystem 100 having the following features: battery voltage buffer 110 , D pulldown 115 , R pull-up 120 , C hold 125 , C hold voltage buffer 130 , D track 135 , R pulldown 140 and voltage buffer 145 . In use, implementation of the OCV inst estimation or sampling subsystem 100 will provide, for example, an OCV estimation. In FIG. 6 , the OCV inst estimation or sampling subsystem 100 can provide the battery charger 10 (not shown) with an estimate of the battery OCV inst as practicably close in time as possible to the end of a periodic OFF-time. Estimation can be through battery terminal voltage minimum-tracking or through use of a sample-hold that obtains a sample of the battery terminal voltage or other methods known to those of skill in the art. The specific components suitable for a specific implementation will depend, in part, on how accurate the OCV inst estimation is desired to be in a particular circumstance, as well as the desired cost and space available in a particular use case.
[0117] Voltage minimum tracking generally requires no sample-hold clock synchronization and can be implemented through use of analog circuits or microcontroller analog-to-digital sampling and subsequent data processing, but estimation accuracy requires design consideration for chosen charging ON-time.
[0118] While use of a sample-hold requires timing control for sampling, sample-hold circuits and associate timing controls are commonly utilized in low-cost microcontrollers and hold behavior can be less sensitive to variations in chosen charging ON-times. If the overall charging system will include a microcontroller, that microcontroller may already include timing controls for data sampling, and the sampling and conversion yields a digital number handy for use in other decision-making. Microcontrollers suitable for use in a battery charger working in accordance with the present invention are available from any of a number of electronic device manufacturers, including but not limited to Analog Devices, Atmel, Cypress Semiconductor, Freescale Semiconductor, Infineon, Samsung, Texas instruments, ST Microelectronics.
[0119] Referring to FIG. 7 , in an exemplary configuration of a suitable charging system in accordance with the present invention, the offset voltage reference system 200 can comprise voltage reference 205 , R VrefDivider1 210 , R VrefDivider2 , R isolator 220 , offset voltage reference buffer 225 and offset voltage reference input 230 . The implementation in FIG. 7 of the offset voltage reference subsystem 200 comprises a default constant voltage reference and includes a provision for application of an optional overriding external offset voltage reference level. In FIG. 7 , the offset reference subsystem 200 can determine the offset voltage during the charging period ON-time that the charger will impose on the battery above and beyond the OCV inst estimate obtained at the end of a previous charging OFF-time, that is, during a previous trough. In one aspect, the offset voltage reference comprises a constant, or substantially constant, incremental voltage whose value can be determined during design of the charger and can be dependent, in part, upon the target maximum average charging current, an approximation of the battery impedance component comprised of battery electrical connection interface resistance and battery electrolyte resistance, and a target for battery power dissipation during charging at the target maximum average charging current.
[0120] Implementations of the battery charger 10 , and attendant processes that are in analog form can be, but are not limited, a simple voltage reference, for which a myriad of implementation options are known. Implementations in microprocessor- or microcontroller-based forms can, for example, comprise a constant reference parameter in software or an analog voltage reference read by an analog-to-digital converter.
[0121] The offset voltage reference subsystem 200 can also include provision for adjustment of the offset voltage magnitude in order to compensate for battery impedance variations in end-products whose batteries are replaceable by the end-product user.
[0122] In some aspects, adjustment of the offset voltage magnitude may be desirable in order to compensate for variations in average charging current. Adjustment of the offset voltage magnitude also may be desirable in order to compensate for other system behavioral variations, such as variation in thermal behavior. Any of a number of techniques can be used to determine the magnitude of offset voltage magnitude adjustment, if such adjustment is desired. In some aspects, the inventive battery charger system, as well as attendant processes and methods, can include the ability to adjust the magnitude but does not include the in-process techniques for determining the amount of adjustment.
[0123] For analog implementations, such adjustment ability may include, but is not limited to, inclusion of an augmenting summation or differential amplifier and associated analog filters and buffers that facilitate the scaling and summing or subtracting of signals inputs to said augmenting amplifiers with a nominal offset voltage reference level and thus effect adjustment of the offset voltage magnitude reference. For example, designers of low-power analog implementations may choose to scale analog signal levels to be as low as possible in order to minimize charging circuit power dissipation and then scale up only the final power stage output voltage to a level suitable for battery charging. The level of such scaling may be dependent upon application-specific details, such as available lower-level power supply levels, but the scaling in itself does not generally change the logic of methodology. As another example, many charging process controllers can include features to request a lower charging current in the event of detection of overheating either in the charging circuit or the battery. The request can be of a proportional level but often takes the form of discrete levels. In some implementations of the inventive process, the exact nature of or motivation for a corresponding level of offset voltage magnitude adjustment may not be determined. For some digital implementations, such as those including use of a microprocessor or microcontroller in order to implement the offset voltage reference subsystem, adjustments include, but are not limited to, an adjustment variable that is added to or subtracted from a nominal offset voltage magnitude or nominal offset voltage scale factor. A suitable example for such a scenario would be the software implementation of the offset voltage magnitude adjustment due to detection of process thermal events.
[0124] In further aspects, the voltage summation 300 and limitation subsystem 400 can determine the target battery terminal voltage to be applied during charging pulse ON-time. In this regard, as shown in FIG. 8 , the voltage summation subsystem 300 provides a nominal target battery terminal voltage that can be, for example the [scaled] sum of the offset reference and the OCV inst estimate from a proceeding proximate or an immediately preceding charging pulse OFF-time. The voltage limitation subsystem 400 (see FIG. 9 ) can then assist in mitigating violation of a relevant maximum battery terminal voltage, V max , by performing a limiting operation after the summation of the offset reference and the OCV inst estimate, so that the output of the limiting operation will be substantially no higher than V max . The output of the limiting operation can be the target battery terminal voltage or a scaled proxy thereof. Alternatively, the functionality of voltage limitation subsystem 400 can also be imposed on the output of the power stage. Numerous methods for doing so exist, such as those commonly used to protect sensitive electronics systems and/or components from power supply spikes or surges. Use of this alternative location of limiting function can result in the need for components that can divert higher current, so the location of limitation can, in some aspects, be upstream of the power stage in the low-power control computation portion of the invented process.
[0125] In a further implementation, voltage summation in analog form can be, but is not limited to, use of operational amplifier summation circuits. FIG. 8 shows the schematic diagram of an analog circuit implementation of a voltage summation subsystem. Referring to FIG. 8 , in an exemplary implementation, voltage summation 300 can comprise the following features: R sum2 305 , R sum2 310 , R sum1 315 , R sum1 320 , R sum1 325 , summation amplifier/buffer 330 , R sum2 335 and nominal target voltage 340 . Voltage limitation in analog form can be achieved by applying to the output of the voltage summation circuit any of a number of known voltage clamping circuits. FIG. 9 shows the schematic diagram of an analog circuit implementation of a voltage limitation subsystem that also provides a scaled-down proxy for the target battery terminal voltage in order to avoid exceeding the allowable input common mode voltage range of the power stage. Referring to FIG. 9 , an exemplary implementation of the voltage limitation subsystem comprises D clamp 405 , clamp voltage buffer 410 , R Vclampdivider1 415 , R Vclampdivider2 420 , R VTgtdivider1 425 and R VTgtdivider2 430 . Voltage summation in microprocessor/microcontroller implementations generally comprises the summing of two variables in software. Voltage limitation in microprocessor/microcontroller aspects generally comprises relatively simple comparison logic in software that assigns an ON-time terminal voltage variable the lower value between the nominal target battery terminal voltage and the reference maximum.
[0126] The power stage of the invention can provide to a battery under charge sufficient current to achieve the target battery terminal voltage during the relevant charging pulse ON-time, and can present to the battery the nature of an open circuit during charging pulse OFF-time. One aspect of the power stage during the charging pulse ON-time can be that of a source that does not attempt to instantaneously impose a current on the battery. This can be due, for example, to the presence of inductance(s) in the internal impedance of many batteries. Imposition of a sudden current pulse upon such inductances can result in battery terminal voltage transients. For charging pulses associated with high charging rates, such resultant battery voltage transients can exceed the V max limit. Accordingly, it can be beneficial for the battery charger power stage to comprise primarily or comprise exclusively a voltage source that induces a charging current pulse.
[0127] The power stage during the charging pulse OFF-time can be useful for at least three reasons. First, the power stage can implement open circuit behavior during the periodic charging pulse OFF-times. As a result, the battery under charge has time to relax and for the capacitive features to suitably discharge during the OFF-times the concentrations of charge and ions that may have accumulated during the charging pulse ON-times. Presentation of an open circuit can assist in the discharge of accumulated charge that can flow into the battery, and not back out into the charger. Second, the power stage can implement open circuit behavior for termination of the charging process as can be directed by an external system-level process oversight control. Third, the power stage of an open circuit behavior can facilitate non-termination pauses in a charging process that an external system process control may deem necessary due to process needs, such as, but not limited to, a need to temporarily suspend charging upon detection of excessive battery or charger temperatures.
[0128] A useful implementation of a power stage can be a switchmode amplifier or power converter with an output during ON-time that tracks the target battery terminal voltage and whose switchmode output includes the ability to implement the OFF-time open circuit behavior. The use of switchmode output converters in battery chargers is already widespread in practice. Alternatively, a switchmode amplifier or converter can be used, where an output ripple remains small relative to an output voltage and current from the amplifier or converter remains continuously on (otherwise known as “continuous mode”) until the end of process. In one aspect of the present invention, the amplifier or converter operational frequency (50 kHz or higher, and not uncommonly over 1 MHz) can be implemented to be sufficiently high to achieve small output ripple, but the maintenance or following of the output voltage generally only occurs during charging pulse ON-time. During charging pulse OFF-time, the switchmode amplifier or converter generally sources substantially no current and consequently revisits discontinuous current delivery at the much lower frequency (for example, about 10 kHz or lower) corresponding to the charging pulse period (for example, about 100 μs to about 100 ms).
[0129] Use of a switchmode power stage, while efficient and common, can provide the need to account for ON-time battery voltage ripple. In various aspects, the sum total voltage of the target battery terminal voltage plus the switchmode output voltage ripple can be maintained to be substantially no greater than V max . FIG. 10 shows a schematic diagram of an exemplary power stage implementation 500 that utilizes an analog amplifier and a unipolar common collector power follower stage. Referring to FIG. 10 , exemplary power stage 500 comprises: summation amplifier/buffer 505 , R VTgtDivider1 510 , R VTgtDivider2 515 , power driver 520 , flyback diode D Flyback 525 , R CurrentSense 530 , periodic switching source 535 and open collector switch 540 .
[0130] The particular exemplary implementation in FIG. 10 includes gain-setting resistors R VTgtdivider1 510 and R VTgtDivider2 515 in order to provide a scale-up gain to compensate for the scale-down of target battery terminal voltage from the voltage limitation subsystem of FIG. 9 . An open-collector pull-down circuit controlled by a timing circuit can either allow the amplifier to follow the target battery terminal voltage during charging pulse ON-time or cause the amplifier to attempt replication of a voltage lower than the battery OCV inst during charging pulse OFF-time. The latter situation will cause the unipolar power driver 520 to switch off when the amplifier output voltage drops lower than battery OCV inst , and thus the amplifier and unipolar driver generally approximate open circuit switch behavior when the charging pulse is OFF. The particular implementation in FIG. 10 also includes an optional high-side current sense resistor, R CurrentSense 530 , between the collector of the power follower stage and the circuit power supply. Should one desire to measure ON-time current in order to adjust the offset voltage, the voltage across R CurrentSense 530 is proportional to current delivered by the power follower stage and can be used as input to compensating feedback circuitry, and this current sensing arrangement is one of several ways familiar to those knowledgeable in the art. Such an implementation of a power stage is fairly straightforward because it can implement the OFF-time switch functionality and poses lower probability of obtaining ON-time voltage ripple whose maximum exceeds V max . Nonetheless, an analog power stage can be less efficient and can be likely to dissipate more heat in a battery charger.
[0131] Irrespective of whether the power stage comprises analog or digital implementation, it can be beneficial to incorporate protection for the switch device against flyback currents from battery internal inductances that might occur during the transition from being a low-impedance ON-time voltage source to being a high-impedance OFF-time open circuit. Such protection appears in most switchmode power converters, but is not always present in analog output stages. Due to impedance switching nature, various implementations of the battery charger systems of the present invention, as well as the attendant processes and methods, can include output flyback protection, such as flyback diode D Flyback 525 , as a feature. Also irrespective of whether the power stage comprises analog or digital implementation, target battery terminal voltage limiting subsystem can be included with the power stage, as opposed to including that functionality with the offset voltage summation subsystem.
[0132] The inventive charging process may also be implemented in a printed circuit board configuration. Methods to fabricate printed circuit boards suitable to generate and apply the inventive charging pulse are known to those of ordinary skill in the art. Such printed circuit board implementations could be particularly well-suited for high-volume, low cost applications, such as used with mobile devices such, such as smartphones, tablets and other such devices.
[0133] The inventive charging process may be implemented using algorithms suitable for generating and providing the inventive charging processes. In other words, an algorithm configured with componentry suitable to provide a charging rate of at least about 1C, wherein such high charging rate can be applied until the battery cell reaches at least about 80% or about 90% or about 95% SOC substantially without exceeding the cell V max . Such algorithms may be deliverable to/implemented by a processing device which may include any existing electronic control unit or dedicated electronic control unit, in many forms including, but not limited to, information permanently stored on non-writable storage media such as ROM devices and information alterably stored on writeable storage media such as floppy disks, magnetic tapes, CDs, RAM devices, and other magnetic and optical media. Such algorithms may also be implemented in a software executable object. The algorithms may also be embodied in whole or in part using suitable hardware components, such as Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), state machines, controllers or hardware components or devices, or a combination of hardware, software and firmware components.
[0134] FIG. 11 is a block diagram that shows the relationships between major physical subsystems of an implementation of the inventive charger that employed a microcontroller for sensing, control, and communication; and a switch-mode power supply (SMPS) for power stage. The microcontroller sensed feedback signals corresponding to battery voltage from the resistive voltage divider comprised of resistors R 1 and R 2 , battery current from the sense resistor R sense , and battery temperature from the thermistor/resistor voltage divider comprised of the thermistor R TH and the reference resistance R THRef . The microcontroller supplied a reference voltage for temperature sensing via use of a thermistor, so that the voltage from the thermistor/resistor voltage divider would correlate with the reference voltage used by the microcontroller for its internal Analog to Digital Converter (ADC). The microcontroller used the feedback signals as inputs to software processes that can implement the signal processing and control functionalities of OCV trough voltage estimation, offset voltage reference determination, voltage summation and limitation. Any of a number of software logic flows may be used for the inventive process, so long as the information flow corresponds to that of FIG. 5 .
[0135] After calculation of the target battery voltage, the microcontroller can use an internal Digital-to-Analog Converter (DAC) and a buffer operational amplifier to issue a voltage signal that can control the output voltage of the SMPS and, thus, controlled V Batt during ON-time. The microcontroller can separately control the ON/OFF status of the SMPS by providing correspondingly a digital switching to the Enable (EN) input of the SMPS. An exemplary SMPS is a Texas Instruments reference design evaluation circuit that that, when enabled, allows regulation of its output voltage to present the desired battery voltage, V Batt . When disabled, the SMPS's power switch can inherently implement the desired open-circuit between charger and battery. The SMPS can include its own flyback diode that handles OFF-time inductive transients. A particular digital implementation can utilize a microcontroller to supervise a SMPS with its own regulation controller, but those schooled in SMPS implementations will recognize that it is also possible to have the microcontroller directly control the power switch and perform voltage regulation. While not necessary for all applications of the inventive charging process, the implementation in FIG. 11 also permits the microcontroller to communicate charging process information to a supervising host device.
EXAMPLES
[0136] The following Examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the present invention is practiced, and associated processes and methods are constructed, used, and evaluated, and are intended to be purely exemplary of the invention and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.) but some errors and deviations should be accounted for. Unless indicated otherwise, temperature is as specified or is at ambient temperature, and pressure is at or near atmospheric.
[0137] An inventive circuit conforming to the set-up of FIG. 11 was used in both Examples 1 and 2 below. The power stage of the inventive circuit comprised a switching regulator (LM22677EVAL board, Texas Instruments) and a unity-gain buffer (AD4638-1, Analog Devices). The microprocessor control was a FRDM-KL25Z (Freescale). The circuit was connected to a generic laptop computer having a software program configured to operate the circuit for application of the inventive charging process and to log data from the charging process.
[0138] Each cell was first discharged to 3.0 V at 0.2C using an off-the-shelf battery charger/discharger (Venom® Pro C, Amain.com). Each discharged cell was connected to the inventive circuit and current was applied from a generic regulated lab-scale power supply. The software control for the circuitry was suitably configured so that the inventive circuit configuration provided the inventive charging pulse with a 9 ms on-time, 1 ms off-time and thus a 90% duty cycle at the desired C rate. The current applied to each cell to achieve the desired C rate was adjusted to account for the inventive pulse having a 90% duty cycle. Results are reported in actual C rate applied to each cell as adjusted for % duty cycle.
[0139] The cell was charged at the desired C rate using the inventive circuit configuration until a measured OCV inst reached the rated V max of 4.2V for each cell, when the software was configured to stop current flow into the cell.
Example 1
[0140] A new 3.7 V 1150 mAH lithium ion “energy” cell for use in mobile devices configured with no protection circuit (Tenergy 503565, Allcell.com) was discharged to 3.0 V at 0.2 V using the off-the-shelf charger/discharger. The discharged cell was connected to the inventive circuit and current sufficient to supply a 1C charge was applied until cell OCV inst reached 4.2V, at which time the current was terminated. The cell was touched periodically during the charging process, and no rise in temperature was noted.
[0141] As shown in FIG. 12 , the cell charged for approximately 1 hour at 1C without OCV inst exceeding V max . As discussed previously, this OCV inst represents the voltage reading during the OFF-time (i.e., when no charge pulse is applied).
[0142] The voltage response resulting from application of the inventive charging process to the Li-ion cell is markedly different from that resulting from the representative prior art 1C constant DC current applied to a similar mobile device-type cell as that shown in FIG. 1 . In particular, the inventive charging process allows a full 1C charge to be applied without the characteristic voltage response that occurs with a 1C constant current and which requires the current to be decreased so as to prevent cell voltage from exceeding V max . Namely, the voltage response resulting from charging with the inventive charge pulse, as shown from OCV inst , is gradual, in comparison to the more pronounced rise with the 1C constant current charge. Using OCV inst as the relevant voltage, one sees that the inventive charge pulse allows the cell to be charged at 1C for the entire charging process which, in turn, allows 100% cell capacity to be reached in much faster as compared to prior art CC/CV charging.
[0143] The offset voltage for the inventive charging process, that is the voltage applied in each pulse in relation to measured OCV inst , was consistently about 150 mV throughout the charging process.
[0144] When the 1150 mAH cell charged according to the inventive methods was discharged using the off-the-shelf charger/discharger, the reported cell capacity was within 5% of a same cell type charged using a 1C CC/CV charging process with the off-the-shelf charger.
Example 2
[0145] A new 3.7V 250 mAH lithium ion “power” cell for use in a radio controlled (“RC”) helicopter (Heli-Max®, Amazon.com) with the protection circuit removed was discharged to 3.0 V at 0.2C. The inventive circuit was used to charge the cell at 4C until OCV inst reached 4.2V. The cell was touched periodically during the charging process and no significant increase in temperature was noted.
[0146] As shown in FIG. 13 , when charged at 4C, the voltage rise over the course of the charging process was gradual. This result shows that the inventive charging process allows an RC-type cell, which in large respects mirrors the charge/discharge behavior of a Li-ion cell used in EV cell packs, to be charged at a high rate to 100% capacity.
[0147] The offset voltage for this charging process, that is the voltage applied in each pulse in relation to measured OCV inst , was consistently about 250 mV throughout the charging process. The higher offset voltage with this cell is thought to be a result of the lower internal resistance of this “power” cell.
[0148] When the 250 mAH cell charged according to the inventive methods was discharged using the off-the-shelf charger/discharger, the reported cell capacity was within 5% of a same cell type charged using a 1C CC/CV charging process with the off-the-shelf charger. (Note that 1C CC/CV is the recommended rate for charging this RC cell.)
Example 3
Prophetic
[0149] Tesla Motors® has recently introduced a DC fast charging infrastructure on interstate highways in the US. Tesla Motors has reported that the Model S 85 kWh battery, which has an approximately 300 mile range at 100% SOC, can be charged to 50% in 20 minutes, 80% in 40 minutes, and 100% in 75 minutes using the company's SuperCharger charging system. This translates to an about 1.5C charging for the first 50% SOC, about 0.9C for the next 20 minutes and about 0.34C for the final 35 minutes. It can then be inferred that the reduction in charging rate seen after 20 minutes, and the more marked reduction after 40 minutes results from the characteristic voltage rise from this prior art fast charging process.
[0150] As disclosed herein, the inventive charging process substantially does not cause the characteristic voltage rise seen with conventional DC fast charging. In a prophetic example, the inventive charging process could reduce the time to charge the Tesla Model S 85 kWh to 100% SOC from the 75 minutes required currently to 40 minutes and reduce the time needed to achieve 80% SOC from 40 minutes to 30 minutes or possibly less. A graph comparing the current Tesla Motors SuperCharger battery charging system to prophetic results with the inventive charging process applied using the same charging rate is shown in FIG. 14 . The time savings would likely be comparable in other vehicles, such as the Nissan Leaf® and Chevy Spark®.
[0151] While the invention has been described in detail, various modifications to the specific implementations illustrated will be readily apparent to those of skill in the art. Such modifications are within the spirit and scope of the present invention defined in the appended claims. The following are non-limiting examples of such modifications:
[0152] Any US patents and patent applications referred to herein are hereby incorporated by reference in their entireties by this reference.
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The inventions herein relate to devices and methods to impart charge to battery cells. Still further, the present invention incorporates to pulse charging methods and systems related thereto that provide improvements in charging speed, efficiency and additional benefits.
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This application is a file wrapper continuation of U.S. application Ser. No. 07/598,169, filed Oct. 16, 1990, for SYSTEM AND METHOD FOR NONINVASIVE HEMATOCRIT MONITORING, now abandoned.
BACKGROUND
1. The Field of the Invention
This invention relates to systems and methods for noninvasively measuring one or more biologic constituent values. More particularly, the present invention relates to noninvasive spectrophotometric systems and methods for quantitatively and continuously monitoring the hematocrit and other blood parameters of a subject.
2. The Prior Art
Modern medical practice utilizes a number of procedures and indicators to assess a patient's condition. One of these indicators is the patient's hematocrit. Hematocrit (often abbreviated as Hct) is the volume, expressed as a percentage, of the patient's blood which is occupied by red corpuscles (commonly referred to as red blood cells).
Human blood consists principally of liquid plasma (which is comprised of over 90% water with more than 100 other constituents such as proteins, lipids, salts, etc.) and three different corpuscles. The three corpuscles found in blood are red corpuscles, white corpuscles, and platelets.
The chief function of red corpuscles is to carry oxygen from the lungs to the body tissues and carbon dioxide from the tissues to the lungs. This critical life supporting function is made possible by hemoglobin which is the principal active constituent of red corpuscles. In the lungs, hemoglobin rapidly absorbs oxygen to form oxyhemoglobin which gives it a bright scarlet color. As the red corpuscles travel to the tissues, the oxyhemoglobin releases oxygen, i.e., is reduced, and the hemoglobin turns a dark red color.
The oxygen transportation functions of the body rely essentially entirely on the presence of hemoglobin in the red corpuscles. Red corpuscles greatly outnumber other corpuscles being about 700 times greater than the number of white corpuscles in a healthy human subject.
Medical professionals routinely desire to know the hematocrit of a patient. In order to determine hematocrit using any of the techniques available to date, it is necessary to draw a sample of blood by puncturing a vein or invading a capillary. Then, using a widely accepted technique, the sample of blood is subjected to a high speed centrifuge treatment for several minutes (e.g., 7 or more minutes). The centrifuging process, if properly carried out, separates the corpuscles into a packed mass. The volume occupied by the packed corpuscles, expressed as a percentage of the total volume of the plasma/corpuscle combination, is taken as the hematocrit.
It will be appreciated that the centrifuge process provides a hematocrit value which includes all corpuscles, not just red corpuscles. Nevertheless, the vastly greater numbers of red corpuscles in a healthy subject allows the hematocrit value obtained by the centrifuge process to be clinically usable in such healthy subjects. Nevertheless, in subjects with low hematocrit or dramatically high white corpuscle content, it may be desirable to diminish the effect of the non-red corpuscles when obtaining an hematocrit value.
There have, been various techniques and devices introduced which have automated and increased the precision of obtaining a hematocrit value. Nevertheless, all the previously available techniques have one or more drawbacks.
Specifically, the previously available techniques all require that a sample of blood be withdrawn from the patient for in vitro analysis. Any invasion of the subject to obtain blood is accompanied by the problems of inconvenience, stress, and discomfort imposed upon the subject and also the risks which are always present when the body is invaded. Drawing blood also creates certain contamination risks to the paramedical professional. Moreover, even in a setting where obtaining a blood sample does not impose any additional problems, e.g., during surgery, the previously available techniques require a delay between the time that the sample is drawn and the hematocrit value is obtained. Still further, none of the previously available techniques allow continuous monitoring of a subject's hematocrit, as might be desirable during some surgical procedures or intensive care treatment, but require the periodic withdrawal and processing of blood samples.
In view of the drawbacks inherent in the available art dealing with invasive hematocrit determinations, it would be an advance in the art to noninvasively and quantitatively determine a subject's hematocrit value. It would also be an advance in the art to provide a system and method for noninvasive hematocrit monitoring which can be applied to a plurality of body parts and which utilizes electromagnetic emissions as an hematocrit information carrier. It would be another advance in the art to provide a system and method which can provide both immediate and continuous hematocrit information for a subject. It would be yet another advance to provide repeatable and reliable systems for noninvasive monitoring of a subject's hematocrit. It would be still another advance in the art to noninvasively and accurately determine a subject's blood oxygen saturation while accounting for the patient's low or varying hematocrit and/or under conditions of low perfusion.
BRIEF SUMMARY AND OBJECTS OF THE INVENTION
The present invention is directed to apparatus and methods for determining biologic constituent values, such as the hematocrit value, transcutaneously and noninvasively. This is achieved by passing at least two wavelengths of light onto or through body tissues such as the finger, earlobe, or scalp, etc. and then compensating for the effects body tissue and fluid effects. As used herein, the term biologic constituent includes proteins, red cells, metabolites, drugs, cytochromes, hormones, etc.
In one embodiment within the scope of the present invention, the wavelengths of light are selected to be near or at the isobestic points of reduced hemoglobin and oxyhemoglobin to eliminate the effects of variable blood oxygenation. At an isobestic wavelength, the extinction coefficient, ε, is the same for both reduced and oxygenated hemoglobin. Thus, at isobestic wavelengths, the amount of light absorption is independent of the amount of oxygenated or reduced hemoglobin in the red cells.
Means are provided for delivering and detecting those wavelengths of light and for analyzing the light intensities. The sensing and radiation emitting elements are preferably spatially arranged to allow ease of use and to be accessible to a patient's exterior body parts. The configuration of the sensing and emitting elements is important to give optimum repeatability of the signals and data derived therefrom.
Memory and calculation means are included which are capable of storing, manipulating, and displaying the detected signals in a variety of ways. For instance, the continuous pulse wave contour, the pulse rate value, the hematocrit value and the continuous analog hematocrit curve in real time, the hematocrit-independent oxygen saturation value, and the oxygen content value of the blood, all as digital values or as continuous analog curves in real time are capable of being displayed.
An important advantage of monitoring and analyzing each individual pulsatile signal is that averaging algorithms may be performed for identifying and rejecting erroneous data. In addition, such techniques also improve repeatability.
Another significant advantage of the present invention is the capability of monitoring multiple wavelengths (including nonisobestic wavelengths) for the simultaneous real time computation and display of the hematocrit-independent oxygen saturation value. Techniques in prior art oximetry have all suffered inaccuracies due to hematocrit sensitivities.
Rather than apply AC-DC cancellation techniques only, it is also within the scope of the present invention to detect and analyze multiple wavelengths using a logarithmic DC analysis technique. In this embodiment, a pulse wave is not required. Hence, this embodiment may be utilized in states of low blood pressure or low blood flow.
It is, therefore, a primary object of the present invention to provide a system and method for noninvasively and quantitatively determining a subject's hematocrit or other blood constituent value.
It is another object of the present invention to noninvasively determine the hematocrit of a subject by utilizing electromagnetic radiation as the transcutaneous information carrier.
It is another object of the present invention to provide a noninvasive hematocrit monitor which may be used on various body parts and which provides accurate quantitative hematocrit values.
It is another object of the present invention to provide a system and method which can provide immediate and continuous hematocrit information for a subject.
It is yet another object of the present invention to provide a repeatable and reliable system for noninvasive monitoring of a subject's hematocrit.
It is still another object of the present invention to provide a system and method for noninvasively determining a subjects's blood oxygen saturation (S a O 2 ) independent of the subject's hematocrit.
It is still another object of the present invention to provide a system and method for noninvasively determining a subject's hematocrit and/or blood oxygen saturation even under conditions of low perfusion (low blood flow).
These and other objects and advantages of the invention will become more fully apparent from the description and claims which follows, or may be learned by the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first presently preferred embodiment of the present invention.
FIG. 1A is an enlarged cross sectional view of the body part (finger) and system components represented in FIG. 1 used in a transmission mode.
FIG. 1B is an enlarged cross sectional view of the body part (finger) and associated system components represented in FIG. 1 used in a reflective mode.
FIG. 2 is a chart showing the optical absorption coefficients of oxyhemoglobin (HbO 2 ), reduced hemoglobin (Hb), and water (H 2 O) versus wavelength.
FIG. 3 is a chart showing the relationship between the extinction coefficient of light at three different wavelengths versus hematocrit for whole blood.
FIG. 4 is a chart showing the relationship between the ratio of the extinction coefficients of two rays having differing wavelengths versus hematocrit.
FIGS. 5A-5D provide a flow chart showing the steps carried out during one presently preferred method of the present invention using the pulsatile component of the subject's blood flow to provide accurate hematocrit and blood oxygen saturation values.
FIG. 6 is a perspective view of a second presently preferred system of the present invention which is applied to the ear and includes structures to squeeze out the blood to blanch the ear tissues.
FIG. 6A is an enlarged cross sectional view of the ear and system components represented in FIG. 6.
FIG. 7 provides a detailed schematic diagram of the low level sensor circuitry included in the presently preferred system of the present invention.
FIGS. 8A-8C provide a detailed schematic diagram digital section circuitry included in the presently preferred system of the present invention.
FIGS. 9A-9D provide a detailed schematic diagram of the analog section circuitry included in the presently preferred system of the present invention.
FIGS. 10A-10C provide a detailed schematic diagram of the power supply and input/output (I/O) section included in the presently preferred system of the present invention.
FIG. 11 is a graph showing variation in oxygen saturation as a function of hematocrit.
FIG. 12 is a graph of ε b805 /ε b970 versus Hematocrit.
FIGS. 13A-13B are graphs of ε versus Hematocrit at two non-preferred wavelengths and ε 1 /ε 2 versus Hematocrit at those non-preferred wavelengths.
FIGS. 14A-14B are graphs of ε versus Hematocrit at two non-preferred wavelengths and ε 1 /ε 2 versus Hematocrit at those non-preferred wavelengths.
FIG. 15 illustrates vertical sensor-emitter alignment and the resulting non-identical ΔX b regions.
FIG. 16 illustrates horizontal sensor emitter alignment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is directed to apparatus and methods for determining biologic constituent values, such as the hematocrit value, transcutaneously and noninvasively. This is achieved by passing at least two wavelengths of light onto or through body tissues such as the finger, earlobe, or scalp, etc., and then compensating for the effects of body tissue and fluid by modifying the Beer-Lambert Law. The principles within the scope of the present invention may also be utilized to provide a hematocrit-independent oxygen saturation and oxygen content measurements as well as noninvasive measurement of blood constituents such as glucose, cholesterol, bilirubin, creatinine, etc.
Although the present invention will describe in great detail the transillumination of various body parts, it will be appreciated that reflectance spectrophotometry may alternatively be employed where transillumination is difficult to accomplish. As used herein, the term "body part" is intended to include skin, earlobe, finger, lip, forehead, etc. Because the principles within the scope of the present invention can be adapted by those skilled in the art for in vitro measurement of hematocrit and other blood constituents, the term "body part" is also intended to include various in vitro blood containers such as tubes and cuvettes.
1. Spectrophotometric Methods
Spectrophotometric methods have been described in the prior art which monitor various metabolites in body fluids. Radiation, typically in the visible or near infrared region, is directed onto an exterior body part for transcutaneous penetration of the radiation. The radiation is then monitored reflectively or transmissively by a photodetector or similar sensor. Radiation spectra are chosen at wavelengths where the metabolite or compound sought for either absorbs highly or poorly. Some examples of such spectrophotometric methods are described in U.S. Pat. No. 4,653,498 for pulse oximetry, U.S. Pat. No. 4,655,225 for blood glucose monitoring, and more recently U.S. Pat. No. 4,805,623 for monitoring various blood metabolites (glucose, cholesterol, etc.).
A theoretical basis for the spectrophotometric techniques is the Beer-Lambert Law:
I=I.sub.0 e.sup.-εXd (1)
Equation (1) may also be written:
ln(I/I.sub.0)=-εXd (1a)
wherein I 0 is the incident intensity of the source radiation, I is the transmitted intensity of the source through the sample, ε is the extinction coefficient of the sought for component, X is the concentration of the sample component in the tissue itself, and d is the optical path length (distance).
The Beer-Lambert Law (1) vitro solute concentration determinations. However, quantitative measurements have not been possible in the body since the scattering of the incident photons passing into and through the integument and subdermal regions is extensive and highly variable. This scattering spoils the Beer-Lambert Law by adding a variable loss of radiation to the measurement and also extends the path length of the incident photons by an unknown amount as well.
Even though optical pulse rate monitors, plethysmographs, and pulse oximeters are known, their development has been accelerated by techniques which allow for cancellation of the optical scattering effects to a large extent. This development began with U.S. Pat. No. 2,706,927 and was further refined by Yoshiya, et. al. (Med. and Biol. Eng. and Computing, 1980 Vol. 18, Pages. 27-32), Koneshi in U.S. Pat. No. 3,998,550, and Hamaguri in U.S. Pat. No. 4,266,554, which utilized a technique of analyzing the resultant opto-electronic signal by dividing it into its AC and DC components. The AC and DC components are manipulated with logarithmic amplifiers in such a way as to eliminate the above-mentioned transdermal optical effects (the variable amount of radiation loss due to scattering in the tissue and the unknown and variable amounts of optical path length increase).
Until now, the AC-DC cancellation techniques have not been successfully adapted for the measurement of hematocrit or hematocrit-independent blood oxygen saturation.
2. Noninvasive Differential-Ratiometric Spectrophotometry
It is assumed that incident radiation passing onto or into a living tissue will pass through a combination of blood, tissue, and interstitial fluid compartments. The light attenuated by such a living tissue can be expressed by the modified Beer-Lambert equation:
I=I.sub.0 e.sup.-(ε.sub.b (X.sub.a +X.sub.v)+ε.sub.t X.sub.t +ε.sub.i X.sub.i)d+G (2)
Equation (2) may also be written
ln(I/I.sub.0)=-(ε.sub.b (X.sub.a +X.sub.v)+ε.sub.t X.sub.t +ε.sub.i X.sub.i)d+G (2a)
Where ε b , ε t , and ε i represent the extinction coefficient in the blood, tissue, and interstitial fluid compartments, respectively; X a and X v represent the arterial and venous blood concentration (X b =X a +X v ), X t represents the concentration of the tissue absorbers, and X i represents the relative concentration of water and dissolved components in the interstitial fluid compartment; d represents the intrasensor spacing; and G is a constant of the geometric configuration.
As the blood layer pulsates, the concentration terms change. The term d can be fixed by the geometric configuration of the device. Taking the partial derivatives of equation (2) with respect to time and dividing by equation (2) gives: ##EQU1## which can be simplified at each compartment and wavelength by letting X'=θX/θt, and G'=θG/θt, and ##EQU2## to give
V'.sub.λ =(ε.sub.b (X'.sub.a +X'.sub.v)+ε.sub.t X'.sub.t +ε.sub.i X'.sub.i)d+G' (4)
Assuming that X t and G do not vary significantly over the pulse time interval, then G'=0 and X' t =0, and equation (4) can be simplified to
V'.sub.λ =(ε.sub.b (X'.sub.a +X'.sub.v)+ε.sub.i X'.sub.i)d (5)
Examining the transport between X a and X v , we can form a proportionality constant K v such that X' v =-K v X' a , representing the reactionary nature of the venous component, and further reduce the above equation to
V'λ=(ε.sub.b (1-K.sub.v)X'.sub.a +ε.sub.i X'.sub.i)d(6)
Since X' a and X' i are not wavelength (λ) dependent, V'.sub.λ values at different wavelengths can be differentially subtracted to produce a hematocrit independent term which contains only ε i X' i information. Although the term V' 805 /V' 1310 provides useful information regarding relative changes in hematocrit, it should be recognized that the simple V' 805 /V' 1310 ratio is not sufficiently accurate for hematocrit value determination unless the ε i X' i term is known or eliminated. For example, the ε i X' i805 term can be neglected since ε i805 is extremely small, whereas the ε i X' i1310 term is about 25%-50% of the ε b1310 value of blood itself and cannot, therefore, be neglected without affecting accuracy.
FIGS. 3 and 12 suggest that a linear combination of V'.sub.λ at λ=805 nm and λ=970 nm will have a near constant value for a range of Hct values. Since the extinction coefficients ε i805 and ε i970 are well known, or can be empirically determined, a precise proportionality constant R 1 can be found to produce
ε.sub.i970 X'.sub.i =V'.sub.970 -R.sub.1 V'.sub.805(7)
This correction term can now be applied with a second proportionality constant R 2 (where R 2 is approximately equal to ε i1310 /ε i970 ) to the V' 1310 term to exactly remove its ε i1310 X' i sensitivity, hence:
ε.sub.b1310 (1-K.sub.v)X'.sub.a =V'.sub.1310 -R.sub.2 (V'.sub.970 -R.sub.1 V'.sub.805) (8)
This corrected term can now be used ratiometrically with V' 805 to remove the (1-K v )X' a and leave the pure extinction coefficient ratio represented by Equation (9) below and shown graphically in FIG. 4. ##EQU3##
It should be noticed that the following assumptions and requirements are essential in hematocrit determinations (but in the case of pulse oximetry these requirements may not be of the same degree of significance).
A. Even though wavelengths λ=805 nm and λ=1310 nm are near isobestic, the actual function of ε versus Hematocrit at each given wavelength must hold hematocrit information that is different in curvature, or offset, or linearity, or sign from the other. See FIG. 3. If the functions ε.sub.λ versus hematocrit are not sufficiently different, then the ratio ε b λ1 /ε b λ2 will not hold hematocrit information. See FIGS. 13A and 13B and FIGS. 14A and 14B. Even though the foregoing discussion refers to the isobestic wavelengths of λ=805 nm and λ=1310 nm, it will be appreciated that other isobestic wavelengths, such as λ=570 nm, λ=589 nm, and λ=1550 nm, may also be utilized.
B. Further, the wavelengths should be selected close enough to one another such that the optical path lengths, d, are approximately the same. Longer wavelengths are preferred since they exhibit less sensitivity to scattering, s: ##EQU4##
C. The geometric or spatial relationship of the emitters and sensors is important. For instance, if vertically aligned emitters are used in an earlobe-measuring device, then the top-most emitter may illuminate a different amount of blood filled tissue than the lower emitter. If only one sensor is used, then there will be a disparity between X' b at each wavelength. See FIG. 15, wherein X b1 >X b2 >X b3 . Furthermore, the sensor-emitter spatial separation distance is very important because the pressure applied to the tissue between the sensor and emitters affects the arteriolar and capillary vessel compliance. This changes the X' as the pressure (or distance) changes. This change in X' then modulates the V'.sub.λ function. Therefore, the sensor-emitter separation distance must be such that the pressure applied to the earlobe, fingertip, or other body member, does not affect the V'.sub.λ function. This sensor separation distance is empirically determined and should generate less than 40 mm Hg applied transmural pressure.
A horizontal alignment (FIG. 15) of the emitters with respect to the single sensor can be arranged so that the emitters and sensors illuminate and detect identical regions of θX.sub.λ1 and θX.sub.λ2. It is important to note that the term d, the sensor-emitter separation, will be different between λ 1 and λ 2 by the cosine of the angle between the sensor and emitter. Therefore, if any misalignment from normal occurs, the term d will not cancel to obtain equation (9).
The preferred arrangement is wherein all the emitters (660, 805, 950, and 1310 nm) are located on the same substrate. This is preferred because the emitters will then illuminate essentially the same X b region.
D. In the case of reflectance spectrophotometry, an aperture for tile sensor and each emitter is required. See FIG. 1B. Also, a sensor-emitter separation is required so that the reflectance of the first layer of tissue, R t , (a non-blood layer of epithelium) does not further exaggerate a multiple scattering effect, i.e. the total reflectance, R, measured would contain spurious information of the epithelial layers'reflectance as well, where: ##EQU5## where R is the total reflectance, R t is the reflectance due to the first tissue-epithelial layer, R b is the reflectance due to the blood layer, and T t is the transmission through the first tissue layer.
The reflectance equations describing R t or R b must now sum all of the backscattered light that the sensor detects, i.e.,:
R.sub.b =∫∫∫(source function )·(scattering function)(12)
While equation (9) describes the theory of the noninvasive hematocrit device, the four assumptions (A-D) are important to the repeatability and accurate functioning of the hematocrit device.
Assuming items A through D are dealt with appropriately, then (9) becomes: ##EQU6## where s is a scattering constant and k is an absorption constant, and where in whole blood:
s=σ.sub.s Hct(1-Hct) (14)
k=σ.sub.a Hct (at isobestic wavelengths) (15)
where σ s is the scattering cross section and σ a is the absorption cross section.
From the foregoing, ε, the extinction coefficient, is not a simple function of the absorption coefficient, k, normally determined in pure solutions. Rather, it contains a diffusion or scattering term, s, which must be accounted for in a non-pure solution media such as whole blood and tissue.
Finally, substituting (14) and (15) into (13): ##EQU7##
Therefore, the ratio ε.sub.λ1 /ε.sub.λ2 is a function of hematocrit. From FIG. 4, a look up table or polynomial curve fit equation may be obtained and utilized in the final displayed hematocrit results. Knowing the actual hematocrit value, it is straightforward to see (FIG. 2) that a wavelength at 660 nanometers can be selected to obtain an e ratio wherein the hematocrit-independent oxygen saturation value is derived. For example, equation (16) would become: ##EQU8## Equation (17) shows both the hematocrit and oxygen saturation dependence on each other.
FIG. 11 graphically demonstrates the need for a hematocrit-independent blood saturation device. As either the hematocrit value or percent oxygen saturation decreases, the percent saturation error becomes unacceptable for clinical usage. For example, it is not uncommon to see patients with a low hematocrit (about 20%) who have respiratory embarrassment (low oxygen saturation) as well. Hence, the clinician simply requires more accurate oxygen saturation values.
Knowing tile hematocrit and oxygen saturation values, the computation of the Oxygen Content is trivial and may be displayed directly (a value heretofore unavailable to the clinician as a continuous, real-time, noninvasive result):
[Oxygen Content]=Hct·S.sub.a O.sub.2 ·K (18)
where K is an empirically determined constant.
Referring to the equations (16) and (9) a decision must be made by the computer as to the suitability of utilizing the Taylor expansion approximation to the logarithm. This algorithm is maintained in the software as a qualifying decision for the averaging and readout algorithms. The Taylor approximation is only valid for small θI/θt vlaues.
3. Nonpulsatile Applications
a. Valsalva's Maneuver to Simulate Pulsatile Case
It is interesting to see the similarities between this AC pulsatile derivation and an analogous DC technique. By taking the logarithm of two intensity ratios, values of ε b and ε i can be obtained from the modified Beer-Lambert equation (equation (2a)). These same extinction coefficients can be manipulated by the identical proportionality constants R 1 and R 2 found previously to exactly eliminate ε i1310 X i and yield ##EQU9## Where the term ##EQU10## represents the logarithm of intensity ratios at X b values of X 1 and X 2 .
It should also be noted that the two derivations (AC and DC) fold into one another through the power series expansion of the ln (1+Z) function: ##EQU11## When the value ΔI=I 2 -I 1 , it can be seen that ##EQU12## which means that for small changes in X b , the AC (partial derivative) and DC (logarithmic) derivations are similar and can each be precisely compensated through this differential-ratiometric technique to provide an noninvasive ε b805 /ε b1310 ratio which is independent of both the constant and time-varying tissue and interstitial fluid terms.
One currently preferred method of obtaining the two intensity ratios is to have the patient perform Valsalva's maneuver. Valsalva's maneuver is an attempt to forcibly exhale with the glottis, nose, and mouth closed. This maneuver increases intrathoracic pressure, slows the pulse, decreases return of blood to the heart, and increases venous pressure. Obtaining intensity measurements before and during Valsalva's maneuver provide sufficiently different intensity ratios to utilize equation (19). Even a deep breath can be enough to obtain sufficiently different intensity ratios.
b. Stepper Motor Technique
Another technique to simulate pulsatile blood flow and to eliminate the skin's optical scattering effects, while at the same time preserving the blood-borne hematocrit and oxygen saturation information, is described below. By utilizing a stepper motor 9 in the earlobe clip assembly 10 on an earlobe 11 of a patient, such as that illustrated in FIGS. 6, 6A, 15, and 16, one can produce a variation of X b sufficient to utilize equation 19. The stepper motor 9 could even produce a bloodless (X b =0) state, if required. However, equation 19 shows that only a difference between X b1 and X b2 is needed.
The major advantage of this technique is that under clinical conditions of poor blood flow, poor blood pressure, or peripheral vascular disease, where pulse wave forms are of poor quality for the (θI/θt)/I technique, this DC-stepper motor technique could be utilized.
c. Oxygen Saturation Determination
The above techniques describe conditions and equations wherein isobestic wavelengths are chosen such that the hematocrit value obtained has no interference from oxygen saturation, hence an independently determined hematocrit value.
One, however, may choose λ 2 (the reference wavelength) in equation (13) at 1550 nm as well. In the radiation region 900 to 2000 nm the blood absorption coefficients depend on hematocrit and water, whereas at 805 nm the blood absorption coefficient only depends on hematocrit. Therefore, utilizing in combination, wavelengths of 660, 805, and 1550 will also give a technique to determine hematocrit (ε 805 /ε 1550 ) and oxygen saturation (ε 660 /ε 805 ).
These 3 wavelengths are particularly important since 660, 805, and 1550 nm (or 1310 nm) are readily available LEDs, such as, respectively, MLED76-Motorola, HLP30RGB-Hitachi, and ETX1550-EPITAXX (or NDL5300-NEC), with the benefits of low cost and low optical power (reducing any question of possible eye damage).
The manufacturing of a multi-chip LED emitter becomes reasonable, cost-wise, and provides increased accuracy since the LED sources have practically no separation distances and appear as a single point source.
This invention may be applied to the determination of other components (included, but not limited to, glucose, or cholesterol) in any range of the electromagnetic spectrum in which spectrophotometric techniques can be utilized.
4. Currently Preferred Apparatus
An earlobe clip assembly 10 as in FIGS. 6, 6A, 15, and 16 (with or without the stepper motor 9 shown in FIG. 6A) and a finger clip assembly 6 used on a finger 7 of a patient as shown in FIGS. 1, 1A, and 1B, are two currently preferred embodiments for practicing the present invention. The photodiodes 3 and emitters 1 and 2 in each are placed in accordance with appropriate alignment.
Consider first the sensor technology in the transmissive mode of operation. An earlobe or fingertip housing can be provided with discreet emitters and two photodiode chips (of different sensitivity ranges, 600-1000 nm and 1000-1700 nm ranges) placed on one substrate, such as a TO-5 can (Hamamatsu K1713-03). The emitters likewise can be two or more emitter chips (i.e., λ=805, 1310, 660, and 950 nm) placed on a common substrate and illuminated through a TO-39 can.
Finally, a single substrate multi-wavelength emitter and a multi-wavelength detector, assembled in one small physical housing for each, make alignment and detection sensitivity more repeatable, and hence more accurate.
The preferred emitter chips would have wavelengths, for hematocrit-only measurements, at 805 nm, 950 nm, and 1310 nm (or 805 nm, 950 nm, and 1550 nm). Although in theory, an emitter having a wavelength of 970 nanometers, rather than 950 nm, would provide more accurate information, 970 nm emitters are not presently available commercially. These wavelengths are currently preferred because of the different curvature and baseline offset of the ε versus Hematocrit at those wavelengths. See FIG. 3. Hence, the hematocrit information will exist in the ratio ε.sub.λ1 /ε 12 . See FIG. 4.
Furthermore, the choice of 805 nm and 1310 nm (or 1550 nm) rather than 570 nm and 805 nm is because there is no water absorption in the 570 nm (or 589 nm) and 805 nm isobestic wavelengths. However, there is tremendous water absorption at 1310 nm and 1550 nm. Hence, the ratio of 570 nm to 805 nm, as a reference, would not yield hematocrit information because there would be no offset due to water in the plasma. See FIGS. 13A and 13B and FIGS. 14A and 14B.
If hematocrit-independent oxygen saturation is desired then the emitter chip wavelengths would be 660 nm, 805 nm, 950 nm, and 1310 nm (or 1550 nm) (the 660 nm is MLED76, Motorola or TOLD 9200, Toshiba). Likewise, the photodetector single substrate could house at least two chips, such as a Hamamatsu K1713-03.
It will be appreciated that those skilled in the art would be able to add other chips to the single substrate at wavelengths sensitive to other metabolites (glucose, cholesterol, etc.). The above mentioned emitter and detector connections can be seen in the analog schematic diagram illustrated in FIGS. 7 and 9B-9D.
The sensor technology in the reflectance mode must conform to two embodiment parameters. See FIG. 1B. The diameter and thickness of the aperture 8 of finger clip assembly 6 in which finger 7 is received in combination with the sensor-emitter separation distances are important to provide a detection region within the subdermis 12 at points a and b of FIG. 1B, where the radiation impinges on blood-tissue without the multiple scattering effects of the epithelial layer, R t . The determination of optimum sensor 3 separation and aperture 8 sizes is done empirically from numerous finger 7 with varying callous and fingernails 13. Minimum sensor separation and aperture diameters can be established wherein R t , of equation (14) is eliminated.
FIGS. 7, 8A-8C, 9A-9D, and 10A-10B detail the electronics of one circuit suitable for use within the scope of the present invention. The memory and computation means (FIGS. 8A-8C) are connected via a "bus" structure between PROMS (U110, U111), microprocessor MC68HC000 (U106), static RAMS (U112, U113), and isolation buffers to the low-level analog circuitry (FIG. 7). A crystal controlled oscillator circuit (U101A,B) is divided by 2 to provides a symmetric master clock to the microprocessor; this clock is further subdivided and used to provide clocking for the analog-to-digital converter (U208) and timer (U109). Strobe lines are generated through a decoder arrangement to drive each of the subsystems of the device and also control the isolation bus buffers (U201,U202).
Timer outputs are fed back into the microprocessor and encoded (U104) to produce interrupts at specific intervals for system functions. One timer is shared by subsystems which control the liquid crystal display means, the keyboard entry means, the audible indicator, and the cycling background system self-test. Another timer is dedicated exclusively to provide a high priority interrupt to the microprocessor; this interrupt drives software which controls the basic sensor sampling mechanism. An expansion connector (J101) is included to allow extended testing of the device or connection to external data-logging equipment such as a printer or computer interface.
The local bus isolates the sensitive analog circuitry from the main digital circuitry. This prevents spurious crosstalk from digital signals into the analog circuitry and thereby reduces superimposed noise on the measured signals. It is on this local bus that the Digital-to-Analog Converters (DAC) and Analog-to-Digital Convertors (ADC) transmit and receive digital information while processing the low-level analog signals.
The Low Level Sensor electronic section, FIG. 7, combines subsystems to both measure and modulate the current produced from each optical sensor. Since the pulsatile component of the optical energy transmitted through or reflected off of tissue comprises only a small part of the overall optical energy incident on the sensor, means are provided to "null out" in a carefully controlled and accurately known way the non-pulsatile component of the light-produced current in the sensing detector. The remaining signal can then be dc-amplified and filtered in a straightforward manner and presented to the ADC (U208) for conversion into a digital value representative of the relative AC pulsatile component. Furthermore, because the relationship between the nulling current and the average value of this AC component is known, the DC component can easily be calculated as a function of the sensing means' sensitivities and the electronic stages' gains. The functions determining these AC and DC values can (if necessary) be trimmed in software by calibration constants which are stored in EEPROM (U307) and retrieved each time the unit is powered on.
The current which modulates the optical sources (LEDs or Laser Diodes) is also controlled (U203) and precisely adjusted (U306) to optimize signal reception and detection. Through software control, the modulation current can be adjusted on a pulse-by-pulse basis to minimize noise-induced inaccuracies. Furthermore, by sampling the sensors with the modulation sources disabled appropriately, background noise (such as 60 Hz) can be rejected digitally as common-mode noise. Thus, by controlling the optical source energy and modulating the nulling current in the photosensor circuitry, it is possible to effectively cancel the effects of ambient radiation levels and accurately measure both the static (DC) and time-varying (AC) components of transmitted or reflected light.
Interrupt-driven software algorithms acquire the sensor data, provide a real-time pulse wave contour, and determine pulse boundaries. Completed buffers (i.e. one entire pulse per buffer) of sensor data are then passed to the foreground software processes for computation. This involves the determination of the background-compensated AC pulsatile and DC static values of intensities for each wavelength. Through averaging and selective elimination of abnormal values, results are then calculated using equation (9) and displayed on the LCD. The modulating and nulling currents are (if necessary) also adjusted to utilize the electronic hardware efficiently and optimally.
5. Summary
Although the foregoing discussion has related to noninvasive analysis of blood hematocrit information, it will be appreciated that the above-mentioned emitters, sensors, and circuitry may be adapted for invasive in vitro analysis of blood hematocrit values. The principles within the scope of the present invention which compensate for spatial, geometric, and tissue variations may be used to compensate for similar variations in an in vitro blood container. Such a device would allow hematocrit values to be determined rapidly and accurately.
Those skilled in the art will also appreciate that the methods within the scope of the present invention for determining blood hematocrit values may be adapted for determining non-hematocrit biologic constituent values such as glucose, cholesterol, etc. To determine biologic constituent information, the effects of competing blood, tissue, and interstitial fluid constituents must be eliminated. It is believed that these effects may be eliminated by appropriate modification of the differential ratiometric techniques described above.
It is important to recognize that the present invention is not directed to determining the tissue hematocrit value. The tissue hematocrit value, in contrast with the blood hematocrit value, reflects the amount of red blood cells in a given volume of tissue (blood, interstitial fluids, fat, hair follicles, etc.). The present invention is capable of determining actual intravascular blood hematocrit and hemoglobin values.
From the foregoing, it will be appreciated that the present invention provides a system and method for noninvasively and quantitatively determining a subject's hematocrit or other blood constituent value. The present invention determines the hematocrit noninvasively by utilizing electromagnetic radiation as the transcutaneous information carrier. Importantly, the present invention may be used on various body parts to provide accurate quantitative hematocrit values.
It will also be appreciated that the present invention also provides a system and method which can provide immediate and continuous hematocrit information for a subject. The present invention further provides a system and method for noninvasively determining a subjects's blood oxygen saturation (S a O 2 )independent of the subject's hematocrit. In addition, the present invention provides a system and method for noninvasively determining a subject's hematocrit and/or blood oxygen saturation even under conditions of low blood perfusion.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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A system for determining the hematocrit transcutaneously and noninvasively. Disclosed are a finger clip assembly and an earlobe clip assembly, each including at least a pair of emitters and a photodiode in appropriate alignment to enable operation in either a transmissive mode or a reflectance mode. At least two, and preferably three, predetermined wavelengths of light are passed onto or through body tissues such as the finger, earlobe, or scalp, etc. and the extinction of each wavelength is detected. Mathematical manipulation of the detected values compensates for the effects of body tissue and fluid and determines the hematocrit value. If a fourth wavelength of light is used which is extinguished substantially differently by oxyhemoglobin and reduced hemoglobin and which is not substantially extinguished by plasma, then the blood oxygen saturation value, independent of hematocrit, may be determined.
It is also disclosed how to detect and analyze multiple wavelengths using a logarithmic DC analysis technique. Then a pulse wave is not required so, this method may be utilized in states of low blood pressure or low blood flow.
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BACKGROUND OF THE INVENTION
The present invention relates to mattresses for beds. In particular, the invention relates to liquid-filled pads that substitute for conventional waterbed mattresses.
A unique attribute of a waterbed mattress is the floating sensation experienced by a user reclining on the mattress. This comfortable floating feeling, and the way in which the surface yields and conforms to the user's body, have contributed greatly to the commercial success enjoyed by waterbed mattresses. There are, however, certain disadvantages with ordinary waterbed mattresses that have limited their use and enjoyment.
One such disadvantage, occurring because of the compliance of the waterbed, is the possibility of excessive flexure of the user's spinal column into the waterbed mattress as the person lies on the mattress. Another disadvantage is the wearisome duration of wave motion of the water, that begins upon rapid movement by the reclining occupant and may continue for an extended time afterward.
A further disadvantage of existing waterbed mattresses is their inability to support concentrated pressure, resulting in a tendency to be depressed in the places where a person pushes upon the mattress to rise away from it. This can be particularly troublesome to persons who are restricted in the movement of their limbs.
Other disadvantages result from the large quantity of water utilized in a waterbed mattress. For example, the heavy weight of the filled mattress may overstress the structure of older buildings and makes transport of a filled waterbed mattress impractical even for short distances within a room. Additionally, the large body of contained water must be kept heated on a continual basis to avoid uncomfortable chilliness as the water absorbs heat from the user's body. Furthermore, there is an ever present danger of water leakage and consequent damage.
To address these problems, one approach used has been to use a waterbed mattress containing less water. It has been found, however, that a reduction in waterbed mattress height below four inches causes an undesirable "bottoming out" effect. The volume of water displaced when the user suddenly shifts position or sits up may be great enough that a portion of the occupant's body collides with the board or other rigid material used to support the underside of the waterbed mattress.
As disclosed by Rodinsky, U.S. Pat. No. 3,958,286, a pad for use atop a conventional mattress to extinguish fires and to provide desired support characteristics comprises a bladder having opposite upper and lower sheets interconnected with each other to define a number of individual, but internally interconnected, water compartments. Such pads, however, are not intended for nor apparently capable of providing the floating sensation that provides a waterbed with its unique character and advantages.
What is desired, then, is an improved bedding structure that provides the sensation of floating provided by a waterbed mattress, in conjunction with the firmness and the handling convenience of an innerspring mattress, while avoiding the disadvantages of previously available waterbed mattresses.
SUMMARY OF THE INVENTION
The present invention provides a bed having the comfort and feel of a waterbed and overcomes the aforementioned shortcomings of previously available waterbed mattresses, by providing a novel flotation cover for use on a conventional mattress. The flotation mattress cover of the present invention comprises a flexible liquid-filled bladder of much smaller height than an ordinary waterbed mattress. In a preferred embodiment the height between the top and bottom members of the bladder is at least 1 inch while not exceeding 2 inches. With a smaller bladder height the desired floating sensation may not be experienced by a heavy person reclining on the mattress cover of the invention. Because the cover is intended for use on a conventional mattress such as an innerspring mattress, if a person sits or presses on the flotation cover in a way that pushes the top member of the bladder down into contact with the bottom, the support and cushioning of the conventional mattress is available rather than the hard support board underlying conventional waterbeds.
To reduce loss of body heat to the water contained within the bladder, and to provide firmness at the top surface of the bladder, a preferred embodiment of the invention includes an insulative layer of padding atop the bladder.
Another aspect of the present invention is a recognition that the desirable floating sensation results in part from a certain amount of wave action or displacement of part of the liquid contained in the bladder. This is made possible by use of an undivided bladder containing the liquid which provides support. Instead of relying on compartmentation or internal baffles that resist bladder distortion but entirely damp the wave action within the bladder, the bladder is filled with only a shallow layer of liquid of insufficient amount to sustain wave action for an unpleasantly long time. However, a preferred embodiment of the present invention does seek to further shorten the duration of wave movement somewhat while not eliminating it completely. To achieve the desired amount of damping, a preferred embodiment of the invention includes a layer of loose fibrous material inside the bladder to resist wave movement of the liquid. The construction of the bladder being of sufficiently flexible sheet material also allows partial absorption of the waves, providing a system in which waves are adequately damped for comfort.
A liner of plastic film material surrounding part of the bladder is preferably provided to temporarily contain any leakage from the bladder itself.
It is therefore a principal object of the present invention to provide a bedding structure having the desirable features of both waterbeds and conventional mattresses.
Another object of the present invention is an improved bedding structure of relatively light weight having the comfort and feel of an ordinary waterbed mattress.
Yet a further object of the present invention is to provide an improved bedding structure wherein a liquid-filled bladder of relatively small height provides the comfort and floating sensation associated with an ordinary waterbed mattress, but without spinal discomfort, sinking, or bottoming out.
A feature of the flotation cover of the present invention is that it is light enough in weight to be portable conveniently even when filled.
An advantage of the flotation mattress cover of the present invention is that it provides the sensation associated with an ordinary waterbed mattress without the need for the great weight of previously available waterbeds.
Another advantage of the flotation mattress cover of the present invention is that it provides the floating sensation of an ordinary waterbed mattress without requiring artificial heating to avoid uncomfortable chilliness.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an exemplary liquid-filled flotation cover embodying the present invention, situated on a conventional mattress and supporting a reclining occupant.
FIG. 2 is a top plan view, at a reduced scale, of the mattress and flotation cover of FIG. 1, shown partially cut away to reveal additional features of the flotation cover.
FIG. 3 is a side view of the mattress and flotation cover shown in FIGS. 1 and 2, taken along line 3--3 of FIG. 2.
FIG. 4 is a sectional view of a portion of the flotation cover shown in FIG. 2, taken along line 4--4, at an enlarged scale.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings which form a part of the present disclosure, FIG. 1 shows a bed 8 having an exemplary flotation cover 10 resting atop a conventional innerspring mattress 12 with an occupant in reclining position on the flotation cover 10. Referring also to FIGS. 2 and 4, the flotation cover 10 comprises a flexible watertight bladder 14, having a top wall 16, a bottom wall 18, and side walls 20. The side walls 20 may be formed by a thermal butt weld 22 (FIG. 4) between marginal portions of top wall 16 and bottom wall 18, or by another conventional fabrication process. The top and bottom walls 16 and 18 are of a length 9 and width 11 substantially coextensive with the length and width of the conventional innerspring mattress 12 (FIG. 2). The bladder 14 is filled with water 24 (FIG. 4) or another suitable liquid to provide floating support, yet the flotation cover 10 remains light enough to be moved fairly conveniently while positioned either on or off the mattress. As contrasted with conventional waterbed mattresses, the weight of the contained volume of water 24 is not sufficient to overstress the framework of older buildings. However, the flotation cover 10 is heavy enough to remain on the mattress 12 without slipping out of place and without a need for separate fastenings.
In a preferred embodiment, the respective walls of the bladder 14 are fabricated of vinyl plastic film thick enough to result in the bladder being substantially inelastic. With this material, for example, the bladder walls 16, 18 and 20 should each have a thickness of at least 15 mils.
Referring to FIG. 2, an inlet tube 26 communicates with the interior of the bladder 14 for filling it with water. A cap 28 is provided as a closure for the inlet tube 26, and may be threaded for secure sealing engagement with the inlet tube 26.
Referring to FIGS. 1 and 4, with the flotation cover 10 atop the mattress 12, when the bladder 14 has been filled with a suitable liquid, such as water, the top wall 16 of the bladder is supported by the contained liquid, providing a flexible movable surface upon which a person may rest. The effect achieved is to provide the sensation of floating similar to that which is felt while floating in an open body of calm water. One factor contributing to this effect is the controlled height 29 of the bladder 14 defined between its top wall 16 and its bottom wall 18 (FIG. 4). Preferably, the height 29 is at least 1 inch but not exceeding 2 inches, and is established by the shape of the bladder 14 and, in particular, by the height of the vertical or side walls 20. This provides a sufficient depth of water within the bladder 14 to create the desired floating sensation. At the same time, the top 30 of the mattress 12 prevents the heavier bodily parts of the occupant, such as the chest region 31, from sinking too deeply into the flotation cover 10 relative to other portions of the person (FIG. 1). This avoids the excessive flexure of the spine that can occur in conventional waterbed mattresses.
Because the flotation cover 10 is supported by the innerspring mattress 12, no discomfort results from displacement of the liquid to the full depth of the bladder 14. A large and sudden exertion of downward pressure on the flotation cover 10, such as when the user suddenly sits up, may at worst bring the user indirectly into contact with the padding of the mattress 12, rather than with a hard supporting board as is used beneath conventional waterbed mattresses. As suggested by FIG. 1 there may be some portions of the top wall 16 and bottom wall 18 forced into mutual contact by displacement of the liquid 24, where the weight of a person is most concentrated, as in the chest region 31, so that such portion of the person is supported more nearly directly atop mattress 12, depending on the concentration of weight, the volume of liquid, and the elasticity of the bladder walls. However, provided there is sufficient buoyancy for the remainder of the person, a small portion supported directly by the mattress 12 does not significantly reduce the floating sensation imparted to the occupant.
Another factor contributing to the desired free-floating sensation provided by the flotation cover according to the invention is the controlled thickness of the flexible material forming the bladder 14. When the preferred bladder material, vinyl plastic film, is used, the thickness of the top wall 16, the bottom wall 18, and the side walls 20 should be at least 15 mils. Referring to FIG. 4, if the thickness of the respective walls of the bladder 14 were made much smaller than 15 mils there would be a tendency for the bladder 14 to swell or balloon up when the bladder 14 was filled with water at all beyond its properly filled state, or in response to increased pressure resulting from a person's weight carried on part of the bladder 14. That is, the walls, if thinner, would be too elastic to contain the water satisfactorily within a substantially fixed volume having the desired rectangular form depicted. Although such ballooning could be controlled by using an extensive network of internal webs or the like between the top wall 16 and bottom wall 18, or by using an extensive network of seams directly interconnecting the top and bottom walls, such methods would be costly and detrimental to the floating sensation that gives waterbed mattresses their unique advantage. Some interconnection is not inconsistent with the present invention, but the amount of interconnection should only damp the duration of the wave motion rather than eliminate it entirely. On the other hand, the walls of the bladder are preferably of plastic film no thicker than 50 mils, so that wave energy encountering the respective walls is partially dissipated in moving the walls, and so that the bladder is comfortably flexible.
Again referring to FIG. 4, it has been found that effective damping of the wave motion may be accomplished by arranging a loosely packed fibrous material 32, such as long, loosely matted, fine polyester filaments within the bladder 14. Proper arrangement of the fibrous material 32 will resist wave motion of the water within the bladder 14 enough to damp out large waves quickly, yet leave enough wave motion to preserve the floating sensation desired of a waterbed.
To protect against possible water leakage and resultant damage to items in the vicinity of the flotation cover 10, a flexible liner 34 partially surrounds the bladder 14, preferably being fitted to the bottom wall 18, side walls 20 and peripheral edges of the top wall 16 as depicted in FIGS. 2 and 4. The liner 34 may be made by welding together the edges of a single sheet of plastic film material to form corner seams 35, as shown in FIG. 2, with each corner extending diagonally over a corner portion of the upper member 18 of the bladder 14, as shown at 36. A marginal portion 37 of the liner 34 extends along each side edge and end edge of the upper member 18 of the bladder 14, while the central portion of the sheet covers the entire bottom of the bladder 14. The liner 34 thus retains itself beneath and around the margins of the bladder 14. If a hole then develops in the bladder 14, the liner 34 will contain all or most of the leakage until the bladder 14 can be emptied for repair or replacement. Preferably, the flexible liner 34 is made of vinyl plastic film having a thickness within the range of 2 to 7 mils.
Referring to FIGS. 3 and 4, the bladder 14 is enclosed by a casing 38 of suitably strong cloth such as mattress ticking. The casing 38 contains and protectively covers an insulative and supportive upper layer of padding, preferably of high density polyurethane foam, including an inner layer 40 and outer layer 42 which are quilted together with the top fabric of the casing 38. The layers 40 and 42 of padding, preferably having a combined thickness 44 in the range of 3/4 inch to 1 inch, serve to capture small pockets of stationary air, thereby insulating the bladder 14 and eliminating the need to heat the water inside the bladder. The quilting stitches 46 and 48 extend through the padding and prevent the respective layers 40 and 42 from bunching up on each other and keep them properly positioned on the bladder 14. The layers 40 and 42 provide vertical support for a person resting on the bed 8, while they are flexible enough to permit enough movement to provide a floating sensation. The padding also spreads the area of application of pressure on the top of the flotation cover 10 somewhat, improving the ability to support a person and still provide flotation. The combined assembly of the filled bladder 14, the layers of padding 40, 42 and the casing 38 provide a flotation cover 10 having an overall thickness 50 in the range of 13/4 to 3 inches.
The fabric casing 38 includes a closure, such as a slide fastener 52, for selectively opening the fabric casing 38 to receive the bladder 14. Instead of a slide fastener 52, closure may be effected by hook-and-portion loop fasteners such as the material well known by the trademark VELCRO, or by snap fasteners (not shown).
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
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A mattress cover for use on a conventional innerspring mattress to give the same feeling as is provided by a waterbed, including a liquid-filled flat bladder having a small height from its top wall to its bottom wall. Insulative padding is included in a casing and held in position atop the bladder to reduce loss of a user's body heat to the liquid, and to provide support. The floating sensation imparted by the flotation cover is facilitated by a wall construction being of sufficient thickness to contain the water within a substantially fixed volume. Fibrous material may be arranged within the bladder to damp wave action of the liquid to a limited degree. A liner surroundingly encloses the lower parts of the bladder within the fabric casing to contain liquid leakage.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to acoustic surface wave devices and, more particularly, to an acoustic surface wave device and method in which an acoustic surface wave propagation path is folded through the use of an acoustic discontinuity in the surface of an acoustic substrate to thereby provide increased time delays and/or bulk wave discrimination.
2. State of the Prior Art
Acoustic surface wave devices have become exceedingly useful in a variety of systems as signal processing elements. For example, acoustic surface wave devices are particularly useful as signal filters and signal delay lines in various frequency ranges because of the flexibility of design characteristics of such devices.
Typical acoustic surface wave delay lines are fabricated on substrates of various materials depending upon the range of frequencies at which the delay line is designed to operate. In the higher frequency ranges on the order of hundreds and megahertz to gigahertz, crystalline materials are typically employed as the acoustic substrate. In the lower frequency ranges on the order of 10 to 30 megahertz, amorphous glasses, fused quartz, or steel strip substrates may be employed. To achieve long delays with acoustic surface wave delay lines, a surface wave is typically propagated along the surface of a moderate or low loss acoustic surface wave propagating substrate material in a single path which is long enough to provide the desired delay. Such single path structures may require a relatively large, one piece substrate for the long delay which may be encountered. Moreover, for delay lines of wide fractional bandwidth, the surface wave mode may overlap bulk wave modes at the optimum frequencies for generating surface waves with interdigital transducers. The surface wave and bulk wave modes usually propagate with different velocities and, in a surface device, the bulk wave modes thus represent spurious energy which may cause large non-linear delays.
OBJECTS AND SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a novel method and acoustic surface wave device which provides discrimination against undesired bulk wave modes.
It is another object of the invention to provide a novel method and acoustic surface wave device for achieving long signal delays through the folding of the surface wave propagation path.
It is yet another object of the invention to provide a novel method and acoustic surface wave device for achieving long signal delays and bulk wave mode discrimination through the folding of the surface wave propagation path by the selective reflection of surface waves with very little reflection of bulk waves.
These and other objects and advantages are accomplished in accordance with the present invention through the provision of a surface wave device formed on an acoustic substrate having an acoustic discontinuity at one surface thereof. The acoustic discontinuity defines a reflecting surface which extends beneath the substrate sufficiently to reflect a substantial amount of incident surface wave energy, propagated along the surface of the substrate without reflecting a substantial amount of bulk wave energy propagated through the substrate. Surface waves are launched along a first propagation path intersecting the reflecting surface defined by the acoustic discontinuity. The first propagation path preferably intersects the reflecting surface at an acute angle so that the surface waves are reflected along a second propagation path differing from the first path while most of the bulk wave energy continues past the reflecting surface along the first path. A suitable pickup or detector may be placed in the second path to detect the relatively pure, reflected surface wave mode.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial, schematic representation of one embodiment of a surface wave device constructed in accordance with the present invention; and,
Fig. 2 is a plan view schematically illustrating a variable tapped delay line constructed in accordance with the present invention.
DETAILED DESCRIPTION
Referring now to FIG. 1, a surface wave device according to the present invention may include a suitable acoustic substrate 10 having one or more acoustic discontinuities 12 and 12' in one surface 14 thereof. A suitable input transducer 16 may be energized by an input signal source 18 to launch acoustic surface waves along the surface of the substrate 14 in a propagation path generally indicated at 20.
The input transducer 16 may be any suitable conventional transducer such as a piezoelectric transducer or an interdigital transducer of the type disclosed in U.S. Pat. No. 3,611,203 assigned to the assignee of the present invention. As is described in the referenced patent, such an interdigital transducer launches surface waves with considerable directivity and can produce both surface and bulk waves in the acoustic substrate 10. In accordance with the present invention, the input transducer 16 is disposed on the surface 14 of the substrate 10 such that generated surface waves (and undesired bulk waves) propagate along the propagation path 20 and intersect the acoustic discontinuity 12 preferably at an acute angle a, i.e., an angle a less than 90°. The acoustic discontinuity 12 defines a reflecting surface which extends beneath the surface of the substrate sufficiently to reflect a substantial amount of incident surface wave energy propagated along the path 20 without reflecting a substantial amount of bulk wave energy propagated through the body of the substrate 10. The acoustic discontinuity 12 may be formed in the surface of the substrate 10 as will hereinafter be described.
Surface waves launched along the propagation path 20 strike the reflective surface defined by the acoustic discontinuity 12 and are reflected along a reflection path 22 which preferably differs from the propagation path 20. The major portion of bulk wave energy propagated along the path 20 is distributed through the body of the substrate 10 and passes beneath the reflecting surface defined by the acoustic discontinuity 12. A suitable bulk wave energy absorber 24 may be provided as is generally indicated in FIG. 1 to absorb the undesired bulk wave energy.
The surface wave energy reflected by the acoustic discontinuity 12 along the reflection path 22 may be again reflected by the acoustic discontinuity 12' along a second reflection path 26. A suitable output transducer 28 such as an interdigital transducer may be disposed in the reflection path 26 to detect the reflected surface waves and to provide an output signal representative thereof at output terminals generally indicated at 30. Of course, if a second reflection of the surface waves is not desired, there is no need for the second acoustic discontinuity 12' and the output transducer 28 may be disposed in the reflection path 22.
In operation, an electrical signal supplied from the input signal source 18 to the input transducer 16 generates surface waves which propagate along the propagation path 20. As was previously mentioned, undesirable bulk waves may also be produced. The surface waves strike the reflecting surface defined by the acoustic discontinuity 12 and are reflected along the reflection path 22.
If the device is to be employed for relatively short, highly accurate signal delays or for other applications in which bulk wave discrimination is the primary concern, the acoustic discontinuity 12 may extend beneath the surface 14 of the substrate 10 by an amount sufficient to reflect a substantial portion of the acoustic surface wave energy propagating along the path 20 without reflecting a substantial amount of bulk wave energy. Thus, most of the bulk wave energy will continue in the direction of the propagating path 20 beyond the acoustic discontinuity 12 and only relatively pure surface mode energy will be reflected along the reflection path 22.
If a relatively long signal delay is required, it may be necessary to fold the path of the surface wave energy through several reflections thereof. Under such circumstances, the acoustic discontinuity 12 and thus the reflecting surface defined thereby may necessarily extend beneath the surface 14 of the substrate 10 by a greater amount to insure that substantially all of the incident surface wave energy is reflected. Otherwise, there may be insufficient surface wave energy at the output transducer 28 to provide a useful output signal due to losses in the substrate material 10. Since most of the acoustic surface wave energy is propagated in the uppermost λ/2 of the substrate, the depth of the acoustic discontinuity may range from about λ/2 to several λ (where λ is an acoustic wavelength in the substrate) depending upon the particular application.
The transucers 16 and 28 and the acoustic discontinuities 12 defining the reflecting surfaces may be arranged in various ways to provide, for example, highly versatile acoustic surface wave delay lines. One such configuration is illustrated schematically in FIG. 2.
Referring now to FIG. 2, wherein like numerical designations have been utilized to designate elements previously described in connection with FIG. 1, the input transducer 16 may be disposed on the surface 14 of the substrate 10 to propagate wave energy along propagation paths 20 and 20'. A signal input transducer of the interdigital type may be utilized since interdigital transducers of the type disclosed in the referenced patent have bidirectional propagation characteristics.
Acoustic discontinuities 12 and 12' may be equidistantly spaced from the input transducer 16 in the propagation paths 20 and 20' to reflect surface waves along the respective reflection paths 22 and 22'. Suitable bulk wave absorbers 24 and 24' may be provided along the edges of the substrate 10 to absorb bulk waves passing beneath the reflecting surfaces defined by the acoustic discontinuities 12 and 12'. A portion of the surface wave energy propagated along the reflection paths 22 and 22' may again be reflected by acoustic discontinuities 32 and 34 disposed in the respective reflection paths 22 and 22'. The portion of surface wave energy reflected by the respective acoustic discontinuities 32 and 34 may be directed along reflection paths 36, 38 and 40 toward an output transducer 28a. Portions of the surface wave energy not reflected by the acoustic discontinuities 32 and 34 may continue along the respective reflection paths 22 and 22' toward additional reflecting surfaces defined by acoustic discontinuities 42 and 44, respectively, disposed in the respective paths 22 and 22'. The surface wave energy reflected by the acoustic discontinuities 42 and 44 may similarly be directed toward an output transducer 28b.
Additional acoustic discontinuities may be provided in the reflection paths 22 and 22' to direct surface wave energy toward additional output transducers 28c-28n at spaced intervals along the paths 22 and 22' as desired. Because the surface waves detected by each of the output transducers traverse different path lengths, each output transducer provides a different delay between the input signal and the output signal. The configuration of FIG. 2 thus provides a plurality of taps from which a variety of signal delays may be obtained.
To facilitate an understanding of the configuration of FIG. 2, it should be noted that surface waves generated by the input transducer 16 typically propagate along a path having some finite width W related to the size of the input transducer. Each acoustic discontinuity in the reflecting path 22 may be split, as illustrated, to reflect a substantial portion of the surface waves propagating along the edges of the reflection path 22 and to pass surface wave energy propagated centrally of the path 22. Each acoustic discontinuity disposed in the reflection path 22' may be of slightly less length than the width W of the reflection path 22' so that surface wave energy along the edges of the path continues along each acoustic discontinuity. Thus, for example, surface wave energy directed toward the output transducer 28a from the reflection paths 22 and 22' is detected and combined by the output transducers and that energy which continues beyond the output transducer 28a bypasses the reflectors formed by the acoustic discontinuity in the reflection paths.
Moreover, each succeeding acoustic discontinuity disposed in the reflection path 22 may be of slightly greater length than the previous one so that it will reflect some of the surface wave that was allowed to pass unreflected by the previous discontinuity. Similarly each succeeding acoustic discontinuity disposed in the reflection path 22' may be of slightly greater length than the previous one so that it will reflect some of the surface wave that was allowed to pass unreflected by the previous discontinuity. In this manner, surface wave energy is detected at different times by each of the detectors 28a-28n thereby providing a variable delay device.
The substrate 10 may be any suitable material preferably presenting a moderate or low loss propagation path to surface wave energy. If an amorphous material is utilized, the propagation paths and reflection paths may be oriented in any desired manner. However, with a crystalline material such as a silicon crystal, it is preferred that a propagation and reflection path be oriented along predetermined axes or directions in crystalline planes so that undesired mode conversion or surface wave to bulk wave conversion does not occur. Accordingly, the choice of angle for the discontinuity with respect to the propagation paths may be selected so that the angle of incidence plus the angle of reflection will deflect the propagation of surface wave energy from one pure mode to another, i.e., from one crystalline axis or direction to another in the plane. Thus, for example, with a crystalline material having orthogonal crystalline axes or direction in a plane, the initial propagation path may be along one of the crystalline axes or direction and the reflecting surface formed by the acoustic discontinuity may be oriented at a 45° angle relative to the propagation path. Upon reflection, the surface waves will thus propagate along a reflection path which also coincides with a crysalline axis or direction in the plane.
For example, a piezoelectric transducer may be formed on a silicon substrate using materials such as zinc oxide. The angle between pure mode axes or directions in a plane in the silicon substrate may be on the order of 116° and thus, by orienting the transducer so that the direction of propagation is in one of the crystalline directions in the use of a 32° reflecting surface will change the direction of propagation of the energy to another crystalline direction in the plane resulting in pure mode propagation in both the crystalline directions in the plane with no undesired mode conversion. In other words, the surface waves are deflected a total of 64° so that the direction of propagation is in the axes or directions in the plane oriented at 116° relative to each other (i.e., 180° - 64° = 116°).
The acoustic discontinuities previously described may be formed in any suitable manner. For example, an acoustic discontinuity may be formed in the surface of most substrate materials by etching or otherwise forming a shallow groove in the surface of the substrate. Since the groove is a complete acoustic discontinuity and its sides form the reflecting surface, the orientation of the groove may be varied in accordance with the desired angle of reflection. The depth of the groove determines the depth of the acoustic discontinuity and since most of the surface wave energy is propagated in the upper λ/b 2 depth of the substrate, a groove of depth λ or slightly greater will reflect most of the surface wave energy. Of course, for maximum reflection of surface waves the depth of the groove may be increased. However, the reflection requirements may be balanced against the bulk wave discrimination requirements of a particular application in determining the depth of the groove. Maximum discrimination against bulk waves, i.e., minimum reflection of bulk waves, will occur with a relatively shallow acoustic discontinuity.
Discontinuities in the propagation constant of a material other than a complete discontinuity provided by the above described reflecting grooves may also provide the necessary acoustic discontinuity for reflection. For example, the surface of the substrate may be loaded or stressed in a line along which it is desired to form the reflecting surface. This loading at the surface of the substrate changes the propagation constant of the material along the line of loading thereby providing an acoustic discontinuity along that line. The effect of the discontinuity on surface waves propagated along the surface of the substrate may be varied by varying the amount of loading.
The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed 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.
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The disclosure relates to an acoustic surface wave device and method for long signal delays and bulk wave discrimination through the folding of a surface wave propagation path. A surface wave device is formed on the surface of an acoustic substrate and a surface wave, acoustic discontinuity is formed in the propagation path of surface waves propagated along the surface of the substrate. The acoustic discontinuity defines a reflecting surface for acoustic surface waves thereby deflecting incident surface waves along a reflecting path differing from the propagation path. Substantially all of the bulk waves propagated along the propagation path continue along this path and can be absorbed or otherwise dissipated. As a result, a substantially pure surface wave mode signal can be detected along the reflecting path. The surface waves may be reflected in this manner, i.e., by folding the path of the surface waves, a number of times as required to obtain a desired delay.
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OVERVIEW
[0001] A pipe coupling and assembly according to the present invention is well suited for use with coaxial pipe systems, such as that disclosed by U.S. Pat. Nos. 5,297,896 and 5,927,762, both to Webb and incorporated herein by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] [0002]FIG. 1 shows a coupling assembly of the present invention in longitudinal cross section.
[0003] [0003]FIG. 2 shows a coupling assembly of the present invention in plan.
DETAILED DESCRIPTION
[0004] [0004]FIG. 1 shows a coupling assembly in longitudinal cross section, generally identified by the numeral 10 . The pipes 20 of the system include an inner tubular member 22 , an outer tubular member 24 and an interstice 26 therebetween. The embodiment of the coupling assembly 10 shown in the Figures comprises two pipe engaging members 30 , which are the same in all material respects. The two pipe engaging members 30 , appearing as mirror images of each other, are shown connected to pipes engaged with a “T” fitting 28 . For purposes of clarity, some elements have been labeled on only one of the two pipe engaging members 30 shown in the Figures.
[0005] A pipe engaging member 30 , preferably metal, is adapted to be secured to the end of a pipe 20 . The pipe engaging member 30 has a proximal end 32 for engaging the pipe, and a distal end 34 for engaging a pipe fitting 28 or second run of pipe. A connecting member is disposed on the distal end 34 , optimally in the form of a threaded locking collar 36 for engaging a corresponding fitting. Alternatively, the connecting member may comprise other coupling means, such as a reducing coupling, straight run of pipe for accepting a coupling, or the like.
[0006] The proximal end 32 of the pipe engaging member 30 comprises a ferrule 38 for engaging the outside surface of the outer tubular member 24 of the pipe 20 . Optimally, the ferrule 38 includes teeth 40 or other suitable means disposed on its inside surface for gripping the outside surface of the outer tubular member 24 and forming a fixed engagement therewith. If the engagement between ferrule 38 and the outer tubular member 24 does not form a seal, sealing means (not shown), such as one or more “O” rings may be provided.
[0007] The proximal end 32 further includes an insertion length 42 for engaging the inside surface of the inner tubular member 22 . The outside surface of the insertion length 42 is preferably provided with teeth 44 or other suitable means for engaging the inside surface of the inner tubular member 22 and forming a fixed engagement therewith. If the engagement between the insertion length 42 and the inner tubular member 22 does not form a seal, sealing means (not shown), such as one or more “O” rings may be provided.
[0008] When the pipe engaging member 30 is installed with a pipe and engaged with a fitting 28 (as described below) or second run of pipe, fluid within the inner tubular member 22 is in communication with the interior 46 of the pipe engaging member 30 , as well as the interior volume 48 of the fitting.
[0009] The pipe engaging member 30 is provided with a groove 50 disposed between the ferrule 38 and the insertion length 42 , preferably between the end of the teeth 40 , 44 and a region 52 at which the ferrule 38 and the insertion length 42 converge. The groove 50 is in fluid communication with the interstice 26 of pipe 20 . A test port 56 is disposed adjacent region 52 in fluid communication with groove 50 and, thus, with interstice 26 . The test port 56 is preferably threaded to allow engagement of a relatively small pipe fitting or elbow 58 . Pipe fitting or elbow 58 is provided with a tube 60 , shown cut away in FIG. 1. Tube 60 connects the two elbows 58 of each coupling insert 30 . Thus, fluid within the two interstices 26 of two pipes 20 is in communication via two grooves 50 , test ports 56 , elbows 58 and tube 60 .
[0010] As noted above, a connecting member, preferably a threaded locking collar 36 , is disposed on the distal end 34 of the pipe engaging member 30 . The locking collar 36 is free to rotate about the longitudinal axis of the pipe engaging member 30 ; but, the locking collar 36 is restricted from moving longitudinally past the distal end 34 of the pipe engaging member 30 by a lip 62 . Thus, the locking collar 36 is free to engage corresponding threads on a fitting 28 . An extended groove 64 is provided adjacent the region 52 (opposite groove 50 , and between region 52 and the lip 62 ). The extended groove 64 allows the locking collar 36 , to be unscrewed from a threaded engagement with the fitting 28 . In embodiments of the inventions employing an alternative connecting member, the extended groove 62 may be modified or omitted as necessary.
[0011] [0011]FIG. 2 shows a side view of the assembly of FIG. 1. The “T” fitting 28 is engaged with two pipes 20 via two pipe engaging members 30 . The proximal end 32 of each pipe engaging member 30 comprises a ferrule 38 and an insertion length (element 42 in FIG. 1), of which only the ferrule 38 is visible in FIG. 2. The distal end 34 comprises a connecting member, preferably a locking collar 36 .
[0012] An elbow 58 is engaged with a test port (element 56 in FIG. 1) of each pipe engaging member 30 , the test port being disposed adjacent a region 52 where the ferrule 38 and the insertion length converge. The test ports, and, in turn, the elbows 58 are in fluid communication with the respective interstices of pipes 20 as shown in FIG. 1 and described above with regard thereto. The two elbows 58 are connected to one another and in fluid communication via tube 60 .
[0013] Thus, the coupling assembly 10 provides fluid communication between the interstices 26 of two pipes 20 engaged to opposite sides of a fitting, such as a “T” fitting, while keeping the fluid therein isolated from the interior 46 of the coupling, as well as the interior volume 48 of the fitting. The invention provides said communication without the need for unwanted cutting of the pipe or provision of adapters required by former attempts to achieve similar goals.
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A pipe coupling assembly for double-wall pipe having an interstice between an inner pipe and an outer pipe, which joins the terminal ends of adjacent sections of the double-wall pipe to a fitting element, as a tee or elbow fitting, as well as to a connector tube bypass assembly. The coupling assembly provides fluid communication between the interstices of the adjacent sections of the double-wall pipe and the connector tube bypass assembly but does not permit fluid from the interstices of the pipes to pass through the pipe fitting.
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This application is a Continuation-in-Part of U.S. patent application Ser. No. 08/449,557 filed May 24, 1995 which is now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to cordless telephones. More particularly, it relates to a cordless headset telephone for providing hands-free cordless telephone communication.
2. The Prior Art
The patent to Silver, U.S. Pat. No. 4,882,745, discloses a cordless headset telephone. The invention consists of a headset having one earpiece connected to a headband and a mouthpiece connected to the earpiece and extending in front of the users mouth. The invention includes a battery within the headset, a charger for the battery in the base unit, a memory for phone numbers, 2-way paging, an intercom, a speaker phone built into the base and a multiuser multi-link capability. The base unit shown, contains a keypad for dialing and using the phone without the headset.
U.S. Pat. No. 5,113,428 to Fitzgerald, discloses a cordless telephone headset. The invention consists of cordless telephone incorporated into a headset. The headset has two earpieces, a microphone flexibly mounted to the headset and a supplemental headstrap. The headset includes buttons disposed on the outside of each earpiece. One set of buttons are for dialing the phone. The second set of buttons provide a plurality of functions such as, for example, MEMORY, FLASH and REDIAL. The supplemental headstrap provides further support and comfort during operation. The headset contains the battery, and the base unit charges the battery when the headset is not in use.
U.S. Pat. No. 4,741,030 to Wilson, discloses a communications headset. The invention consists of a cordless telephone incorporated into a hands free headset. The headset has a head band with one earpiece and a mouthpiece extending from the earpiece and disposed in front of the mouth of the user. The mouthpiece of the invention has a plurality of dialing buttons disposed around the microphone for dialing a desired number. A rechargeable battery pack is disposed on the headband portion of the headset. An ear support member opposite the earpiece, rests on the users other ear to provide comfort and support during use.
SUMMARY OF THE INVENTION
The present invention provides a cordless headset telephone having an adjustable headband formed by joining a first and a second curved portion. In one embodiment, the first curved portion has an end battery compartment for receiving a rechargeable battery and a pivotable pad disposed on the inside surface thereof. The pivotable pad provides comfort and support of the headset against the users head during operation. The second curved portion of the headband includes a flexible ribbed portion at the top side where the first and second curved portions are joined. On the inside surface of the second curved portion is an earpiece for placement on the user's ear.
An extended microphone arm is rotatably connected to the second curved portion at the base of the earpiece. The extended microphone arm has three operable positions and includes a rotatable microphone attached to the end thereof. The first operable position of the microphone arm is in a first headset position where it extends outwardly to the front of the users mouth. The second operable position is a handset position where the microphone arm is rotated and positioned such that it extends along the inside surface of the curved portions of the headset. This allows the headset to be held as a conventional handset with the microphone disposed adjacent the pivotable support pad. The third operable position of the microphone arm is in a second headset position whereby said microphone arm is displaced approximately 180 degrees from the first operable headset position to allow the use of the headset with the other ear. The rotatable microphone has multiple separate positions for providing multiple different functions, and includes a multi-color LED mounted therein for indicating the present position and function of the microphone.
The headset includes a ringer built therein and disposed near the top of the headset. A dial switch with volume control enables the user to control the use of the ringer and the volume thereof. A releasable keypad is contained within the second curved portion of the headset opposite the earpiece. The keypad can be released from the headset and used as any conventional phone keypad. A retractable wire connects the keypad to a retracting mechanism within the headset and allows for selectively releasing and retracting the keypad out of and into the headset.
In a second embodiment of the invention, a plurality of control buttons are added to the headset for controlling the telephone operation and special functions thereof. An external antenna is provided for sending and receiving the cordless transmissions. In addition, a clip is added to the removable keypad to enable the connection of the keypad to the clothing of the user.
In a third embodiment of the invention, the battery compartment for receiving the rechargeable battery is disposed underneath the removable keypad on the second curved portion of the headset.
In a fourth embodiment of the invention, the battery compartment for receiving the rechargeable battery is disposed within the removable keypad. Furthermore, the antenna for sending and receiving signals is internal and incorporated into the adjustment band of the headset.
Further embodiments of the invention replace the use of an extended microphone arm and microphone with an combined earpiece speaker/microphone. The elimination of the extended microphone arm streamlines the headset, and makes it easier to use.
It is therefore an object of the present invention to provide a cordless headset telephone that has two operable positions as a headset and one operable position as a handset.
Another object of the invention is to provide a cordless headset telephone that is adjustable to allow the user to place the earpiece on the ear of their choice.
It is another object of the invention to provide a cordless headset telephone that includes a releasable keypad for enabling the dialing of the phone without removing the headset.
Yet another object of the invention is to provide a cordless headset telephone that includes a ringer built therein and positioned away from the ears of the user.
It is still another object of the invention to provide a cordless headset telephone that does not require an additional phone for performing any telephone functions.
Yet another object of the invention is to provide a cordless headset telephone that utilizes a combined earpiece/microphone.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings which disclose four embodiments of the present invention. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.
In the drawings, wherein similar reference characters denote similar elements throughout the several views:
FIG. 1 is a perspective view of a first embodiment of the cordless headset telephone according to the invention;
FIG. 2 is a perspective view of a second embodiment of the cordless headset telephone according to the invention;
FIG. 3 is perspective view of a third embodiment of the cordless headset telephone according to the invention;
FIG. 4 is a perspective view of a fourth embodiment of the cordless headset telephone according to the invention;
FIG. 5 is a perspective view of the cordless headset telephone in its second operable position;
FIG. 6 is the keypad of the cordless headset telephone according to the invention;
FIG. 7 is the microphone of the cordless headset according to the invention;
FIG. 8 is a perspective view of a fifth embodiment of the cordless headset according to the invention;
FIG. 9 is a perspective view of a sixth embodiment of the cordless headset according to the invention;
FIG. 10 is a perspective view of a seventh embodiment of the cordless headset according to the invention; and
FIG. 11 is a perspective view of an eighth embodiment of the cordless headset according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Turning now in detail to the drawings, FIG. 1 shows a first embodiment of cordless headset 10 having a first curved portion 12 and a second curved portion 14 adjustably connected together to form the headband of the cordless headset. First curved portion 12 includes a battery compartment 20 for receiving a rechargeable battery and a pivotable comfort/support pad 22 for providing comfortable support on the user's head when headset 10 is in its first operable position. Battery compartment 20 can include contacts (not shown) for engaging a charging device which charges the rechargeable battery while contained in said compartment.
Second curved portion 14 has a flexible headband portion 18 which is connected to first curved portion 12 via adjustment band 16. Flexible portion 18 can be configured in any suitable known form. As shown, flexible portion 18 is a plurality of small rectangular members connected together in next adjacent relation with each other. Flexible portion 18 is designed to be resilient and allow the opposite free ends of first curved portion 12 and second curved portion 14 to be extended outward for fitting the headset on the users head. Adjustment band 16 slides in and out flexible headband 18 as indicated by the direction arrow B.
The second curved portion 14 has a keypad 26 releasably connected thereto through a wire 34. Release button 40 on curved portion 14 engages the keypad lock receptacle 42 on keypad 26 to lock the keypad into the headset. A retraction mechanism within curved portion 14 (not shown) is activated by button 38 and retracts wire 34, and thereby keypad 26, into curved portion 14. Keypad 26 can be removed from curved portion 14 of headset 10 and used to dial the phone without having to remove the headset. The retraction mechanism maintains keypad wire 34 under tension when being withdrawn from curved portion 14 and subsequently locks wire 34 in place when the withdrawal action stops. Thus, the retraction mechanism maintains wire 34, and thereby keypad 26, in the desired position until released by release button 40. Wire 34 is thin enough to allow for easy withdrawal and retraction of keypad 26, but is strong enough to stand up against consistent use.
An earpiece 28 is disposed on the inside surface of curved portion 14 for engaging the user's ear. Earpiece 28 is generally made from a soft material such as foam rubber, but may be made of any suitable known material. A microphone arm 30 is connected to curved portion 14 at the base of earpiece 28, and extends outwardly therefrom. Microphone arm 30 terminates with a microphone 32 at its end. Microphone arm 30 is rotatably displaceable about earpiece 28 as indicated by direction arrow A. Microphone 32 at the end of microphone arm 30 is rotatable thereon as indicated by arrow directions C. Microphone 32 can be a condenser microphone or any other suitable known type of microphone.
In the position shown in FIG. 1, microphone arm 30 is disposed such that earpiece 28 will be placed on the left ear of the user. Microphone arm 30 can be rotated approximately 200°-250° in the direction of arrow A such that the user may position earpiece 28 on the right ear. This is a third operable position of headset 10.
In this embodiment, cordless headset 10 includes an internal antenna that is built directly into said headset. The antenna enables the headset to transmit and receive information to and from a base unit associated therewith. The base unit (not shown) can be a standard base of any suitable known type. FIG. 8 shows an alternative embodiment of the headset 10 shown in FIG. 1. In this embodiment, microphone arm 30 with microphone 32 have been replaced with an combined earpiece speaker/microphone 29. The technology for combined earpiece speaker/microphone devices is shown in U.S. Pat. Nos. 5,208,867, 4,972,491, and 3,258,533 which are hereby incorporated by reference. Other existing speaker/microphone combinations may also be incorporated without departing from the scope of the invention. The use of earpiece speaker/microphone 29 eliminates the need for the extended microphone arm and microphone on the end thereof, and prevents any loss of transmission caused by ambient noise, or the microphone and extended microphone arm not being directly disposed in front of the users mouth.
FIG. 2 shows a second embodiment of headset 10 with an external antenna 60 mounted on curved portion 14 for sending and receiving signals. A rotatable dial switch 56 is disposed on the side of curved portion 14 and enables the switching on and off of the ringer in addition to controlling the volume of the ringer. A plurality of control buttons 58 have been added to curved portion 14 for providing a plurality of telephone functions at the headset itself. For example, buttons 58 can be memory buttons for dialing regularly called numbers or can be buttons for hold, mute, intercom, channel changing, etc. Keypad 26 includes a clip 54 mounted on the outside surface thereof for allowing the placement of said keypad on the belt or other convenient remote location on the users body. FIG. 9 shows the headset 10 according to FIG. 2 with the addition of the combined earpiece speaker/microphone 29.
FIG. 3 shows a third embodiment of the headset 10 incorporating the features of the previous embodiments, except that the battery compartment 62, for receiving a rechargeable battery, is disposed on curved portion 14 and underneath keypad 26 when said keypad is disposed in the fully retracted position. In this embodiment, external antenna 60 is positioned on curved portion 12. FIG. 10 shows an alternative embodiment of headset 10 of FIG. 3 with the combined earpiece speaker/microphone 29.
FIG. 4 shows a fourth embodiment of the invention where battery compartment 64, for receiving a rechargeable battery, is disposed within keypad 26. Furthermore, headset 10 has an internal antenna that is incorporated into adjustment band 16 which eliminates the need for an additional external antenna. FIG. 11 shows the use of combined earpiece speaker/microphone 29 in earpiece 28 as an alternative to microphone arm 30 and microphone 32.
FIG. 5 shows headset 10 in its second operable position. Microphone arm 30 is connected to a rotating disk 50 mounted at the base of earpiece 28. Rotating disk 50 rotates independently from earpiece 28 which does not rotate. Microphone arm 30 has been rotated approximately 100° from its first operable position to extend down along the inside surface of headset 10. Curved portions 14 and 12 and flexible portion 18 are in their most closed position allowing the user to hold the headset as a handset. In this configuration, microphone 32 is now disposed adjacent battery compartments 20 and comfort pad 22, and thereby allows the user to place earpiece 28 on the ear while situating microphone 32 in front of their mouth for receiving communication.
When headset 10 is in this second operable position, earpiece 28 can be placed on either the left or right ear of the user without interfering with or changing the operation thereof.
FIG. 6 shows keypad 26 with the wire 34. Keypad 26 provides all of the basic telephone operations and may include other functions such as redial, pause, flash, mute, hold, and channel changing. Keypad 26 with retractable wire 34 can be removed from headset 10 and positioned in a remote location on the user's body, such as, for example, in their shirt pocket or on their belt to enable easy access to the dialing keypad without having to remove or displace headset 10 from the users head.
FIG. 7 shows rotatable microphone 32 having a tri-color LED 46. Microphone 32 has three separate positions for providing three separate functions of the microphone. Microphone 32 can control such functions as, mute, hold, on hook, off hook, etc. Tri-color LED 46 has specific colors designated to indicate the present position of rotating microphone 32 and can have a flashing mode for indicating that the phone is ringing. In another embodiment, microphone 32 can have multiple separate positions for providing multiple separate functions of the microphone. In addition, LED 46 would be multi-colored such that for each of the separate multiple positions, LED 46 would have a separate color for each position of microphone 32.
All embodiments of cordless headset telephone 10 include an on/off switch 36 which enables the user to manually answer the phone from the headset without having to go to the base or an external extension to answer the phone. Headset 10 and its respective parts can be manufactured from plastics or any other suitable known material.
FIGS. 8, 9 and 10 show a fifth, sixth and seventh embodiment of the invention where the microphone and extended arm have been removed and replaced with a combined earpiece speaker/microphone 29. The technology for combined earpiece speaker/microphone devices is shown in U.S. Pat. Nos. 5,208,867, 4,972,491, and 3,258,533 which are hereby incorporated by reference. The use of earpiece speaker/microphone 29 eliminates the extended microphone, and prevents any loss of transmission caused by the microphone and extended microphone arm not being directly disposed in front of the users mouth.
While several embodiments of the present invention has been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims.
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A cordless headset telephone for cordless hands free telephone communication between a base unit and the headset. The cordless headset has a first and third operable position as a headset and a second operable position as a hand held telephone receiver. A further embodiment of the cordless telephone headset replaces the extended microphone arm and microphone with a combined earpiece speaker/microphone.
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BACKGROUND OF THE INVENTION
The present invention relates to a process for sterilization, especially for the sterilization of packaging materials (and in particular plastic materials and materials having a plastic coating), by wetting with an active-chlorine-containing sterilizing solution.
Processes of this type are used, for example, in the sterilization of packaging for milk or other drinks or foodstuffs, where the packaging material is a web of plastic material or plastic-coated foil. In known processes, the packaging material is sterilized by an approximately 30% solution of hydrogen peroxide at a high temperature (about 90° C.). Such a process should destroy all bacteria spores which could spoil the food or lead to food poisoning. However, the heating required for such a process is complex and expensive, and the subsequent elimination of the hydrogen peroxide, which is used in high concentration, may be dangerous for the operators. Also because of the high hydrogen peroxide concentration, there is the risk of dangerous residues remaining in the packaged foodstuff.
We have now discovered a reliable process for sterilizing the surfaces of packaging materials, which process will destroy bacterial spores at a relatively low temperature while allowing the sterilization solution to be handled without danger and without any undesirable residues remaining in the packaged product.
SUMMARY OF THE INVENTION
Thus, the present invention consists in a process for sterilizing an article by wetting said article with a sterilizing solution having an active-chlorine concentration of from 500 to 20,000 mg/1 and treating the thus sterilized article with an aqueous solution of hydrogen peroxide to deactivate any remaining active chlorine.
For the sterilization itself active-chlorine-containing solutions of relatively high concentration are used, whereas in known methods they are not used because of the residues that result. In the process of the present invention the harmful active-chlorine residues are made harmless by the addition of hydrogen peroxide, the concentration of which may be kept so low that the usual disadvantages of hydrogen peroxide treatment do not occur.
BRIEF DESCRIPTION OF THE DRAWING
Two preferred embodiments of the process of the present invention are illustrated in the accompanying drawing:
FIG. 1 is a diagrammatic representation of a preferred apparatus for carrying out the process according to the invention; and
FIG. 2 is a diagrammatic illustration of a modification of the apparatus shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus of FIG. 1 and FIG. 2 can conveniently be used for sterilizing strips of polyethylene coated packaging material such as is used in the production of milk cartons. In FIG. 1, a tank 1 contains a chlorine bleach solution (pH 12 and active chlorine concentration about 100 g/l) and is connected by a pipe 2 having a valve 3 to a storage vessel 4 (capacity about 3 1). The solution is continuously recycled by a pump 6 through a pipe 7 between the vessel 4 and an immersion bath 5.
The temperature of the sterilizing solution in the immersion bath 5 is preferably maintained at about 60° C. A tank 8 is connected by a pipe 9 and a valve 11 to the storage vessel 4. The tank 8 is a container for an acid (conveniently 70% phosphoric acid) or an alkali which is used to adjust the pH of the solution in the vessel 4 and bath 5. Sensors 12 and 13 (which measure redox potential and pH respectively) in conjunction with a redox control circuit 14 and a pH control circuit 15 are used to operate the valves 3 and 11 to control the active chlorine concentration and the pH of the solution in the storage vessel 4 (the preferred values are 10,000 mg/l and 8 respectively). The absolute active-chlorine concentration may also be determined simply by titration with sodium thiosulphate, giving a value in ppm of chlorine instead of in mg/l. Active chlorine as referred to herein means this titratable chlorine.
A web of packaging material 16 to be sterilized is led over a roller 17 in the bath 5. The wetted web is then passed through a chamber 18 (about 2 meters in length), at such a speed that about 10 seconds are available for sterilization, at the end of which are disposed two squeeze rollers 19 for removing the major part of the sterilizing solution adhering to the packaging material. About 300 ml/hour of sterilizing solution passes beyond the squeeze rollers 19 when the running speed of the packaging material is the optimum value of about 20 cm/second for a chamber 2m. in length.
In order to remove the remaining active-chlorine, the web 16 is fed through a wash bath 21 containing an aqueous solution of hydrogen peroxide (preferably 0.2% by weight). Pipes 22 and a pump (not shown) connect the wash bath 21 to a tank 23 which stores the aqueous hydrogen peroxide (preferably at room temperature e.g. 20° C). The capacity of the tank 23 is such that the hydrogen peroxide concentration in the wash bath 21 during one production day does not fall by more than 10% as a result of the reaction with the active chlorine. Squeeze rollers 24 or a powerful jet of sterile air are used to remove excess liquid from the web 16. A packaging container may then be constructed from the web and filled with, for example, milk. It has been found that in the worst case a maximum of about 0.1 ml of 0.2% aqueous hydrogen peroxide can remain in a 1 liter container. This concentration (0.2 mg/l) is approximately the same as that achieved by other substantially more complicated processes.
The apparatus shown in FIG. 2 differs from that shown in FIG. 1 in that the web 16 is sterilized by spraying a fine film using two turbo atomizers 25 instead of by passing it through an immersion bath. The diameter of the droplets produced by the atomizers may be about 10μ.
An advantage of the process of the present invention is that a sufficiently reliable sterilization can be obtained, without the use of a high temperature and the necessary costly equipment. The residues remaining on the packaging material after treatment do not contravene foodstuffs regulations.
The reduction in the bacteria spore count after sterilization may be determined in the following manner: a sterilizing solution is poured over dry bacteria spores (with garden earth as the carrier) and/or dry mould spores (with sea sand as the carrier); after 15 seconds a part of the resulting suspension is added to a sodium thiosulphate solution to deactivate the sterilizing solution. The surviving spore or germ count is then determined by Koch's plate method. This count is then compared with that after heating for 10 minutes at 80° C. This latter treatment, known as "water control", destroys vegetative germs. Applying the following formula to the two germ counts gives the "decimal destruction rate" (R) which is a measure of the effectiveness of the sterilization process. Values of R between 3 and 4 (a reduction in the spore count by a factor of from 1,000 to 10,000) are accepted as sufficient in foodstuffs chemistry. ##STR1##
The effectiveness of the process of the present invention can be seen from Tables 1 and 2 below. Table 1 relates to conventional sterilization using an approximately 30% aqueous solution of hydrogen peroxide. It can be seen from this Table that only at very high temperatures is a satisfactory R value obtained. Table 2 shows the R value for sterilization according to the present invention, the last line of Table 2 indicates that if the active chlorine concentration is too low the sterilization is insufficient. Earth spores and Aspergillus niger bacteria were used for this comparison.
Table 1______________________________________ R values ofSterilization Earth Aspergillusmedium Temperature spores niger______________________________________30% H.sub.2 O.sub.2 by wt. 20° C 1.76 4.0530% H.sub.2 O.sub.2 by wt. 60° C 2.13 6.3030% H.sub.2 O.sub.2 by wt. 90° C 3.61 over 7.5______________________________________
Table 2______________________________________ R values ofSterilization Earth Aspergillusmedium Temperature spores niger______________________________________2.0 g/l Cl (pH 8) 20° C 3.43 4.829 g/l Cl (pH 8) 20° C 3.18 4.171.1 g/l Cl (pH 8) 60° C 3.46 5.100.11 g/l Cl (pH 8) 60° C 1.65 3.75______________________________________
The following substances are suitable for preparing sterilizing solutions, preferably aqueous sterilizing solutions, according to the present invention:
sodium hypochlorite;
calcium hypochlorite;
chlorinated trisodium phosphate;
chlorine dioxide;
sodium p-toluenesulphochloroamide;
p-toluenesulphonsulphochloroamide;
N-chlorosuccinimide;
1,3-dichloro-5, 5-dimethylhydantoin;
trichloroisocyanuric acid and salts thereof;
dichloroisocyanuric acid and salts thereof;
trichloromelamine or dichloroglycoluril.
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A process for sterilizing an article, more particularly packaging material, by wetting the article with a sterilizing solution having an active-chlorine-concentration in the range of 500 to 20,000 mg/l, and treating the sterilized article with an aqueous solution of hydrogen peroxide to deactivate any remaining active-chlorine.
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CROSS REFERENCE TO RELATED APPLICATION
This application is related to my copending patent application Ser. No. 345,835, filed Feb. 4, 1982, now abandoned.
FIELD OF THE INVENTION
The present invention relates to a method to prevent and/or treat dry skin and loss of natural oiliness by the external application of effective dosages of the free alcohol of dehydroepiandrosterone or its derivatives, for example, acetate, in suitable vehicles.
BACKGROUND OF THE INVENTION
Almost all menopausal and post-menopausal women, many women over thirty-five, and most women over forty years of age, and some older men frequently complain that the natural oiliness of their skin is markedly diminished.
A paper entitled "The Effect of Aging on the Activity of the Sebaceous Gland in Man" by Pochi. P. E. and Strauss, J. S. that was published in Advances in Biology of Skin, Vol VI: Aging, edited by Montagna, W., Pergamon Press, N.Y. (1965), described the reduction in mean sebum (oil) secretion in males and females in relation to advancing age. FIG. 1 herein illustrates this reduction in mean sebum production with aging.
Testosterone therapy increases skin oil production in menopausal and post-menopausal women. However, it produces unwanted superfluous facial and body hair and other systemic masculinizing side effects and is therefore rarely used.
Dehydroepiandrosterone is a steroid. It and its sulfate are secreted by the adrenal glands, circulate in the bloodstream, and are excreted in urine as derivatives of dehydroepiandrosterone.
As shown in FIG. 2, dehydroepiandrosterone sulfate levels in the blood have been shown to reach a peak in early adult life and then gradually decline with advancing age (Orentreich Foundation for the Advancement of Science, Inc., Annual Report, 1979).
The structure for dehydropiandrosterone is as follows: ##STR1##
In a study entitled "Biological Activity of Dehydroepiandrosterone Sulfate in Man" by Drucker, W. D., Blumberg, A. M., Gandy, H. M., David, R. R., and Verde, A. L., that was published in the Journal of Clinical Endocrinology and Metabolism, 35: 48-54 (1972), sebum production was used as a measure of androgenic activity associated with the oral administration of dehydroepiandrosterone sulfate. Drucker et al., however, did not address the problem of dry skin in normal older women and some older men. Indeed, the experiments of Drucker et al. were conducted with five abnormal, androgen-deficient, hypogonadal males, ages 15, 20, 30, 34 and 35, and a three-month-old female with 21-trisomy syndrome.
In U.S. Pat. No. 4,005,200, a new use of dehydroepiandrosterone sulfate as a parturient canal conditioning agent was disclosed. U.S. Pat. No. 4,005,200 describes systemic administration of dehydroepiandrosterone sulfate to a pregnant female during the 37th to 39th week of pregnancy to improve the maturity of the parturient canal and the sensibility of the uterine musculature to oxytocin. U.S. Pat. No. 4,005,200 mentions that it had been proposed to use dehydropiandrosterone sulfate clinically in combination with estrogens in the treatment of various syndromes associated with climacterium, but the problem of skin dryness was not addressed in this patent.
In recent articles (Jan. 17, 1982 edition of Science News, "Antiobesity Drug May Counter Cancer, Aging"; Jan. 22, 1981 edition of the Chicago Tribune, "Amazing New Drug That May Lead to Longer Life", Kotulak, R.), uses of dehydroepiandrosterone and analogs thereof were described to counter obesity and prevent cancer. These articles did not, however, address the problem of skin dryness.
I previously discovered a method (described in my prior copending application Ser. No. 345,835 now abandoned) for treating dry skin in humans by internally administering an effective dosage of the alcohol and/or one or more salts of dehydroepiandrosterone. This treatment is particularly useful in treating dry skin in menopausal women. This treatment can also be employed to treat premenopausal females with a low endogenous dehydroepiandrosterone production. Furthermore, males who suffer from dry skin due to low plasma levels of testosterone and/or dehydroepiandrosterone and its sulfate can be treated in accordance with my previous invention.
Menopausal and post-menopausal and other older women usually have a distinct reduction in dehydroepiandrosterone sulfate levels in the blood which is generally accompanied by a reduction in the oil production of the skin and results in dryness of the skin. Such dry skin problems generally affect the entire body. The face and head, however, have the highest population of sebaceous glands and therefore those areas are the mose vulnerable to these problems. I previously found that the internal administration of the alcohol or one or more salts of dehydroepiandrosterone increases the blood level of dehydroepiandrosterone and its sulfate and reduces skin dryness. The reduction of activity of sebaceous glands with aging and at the onset of menopause is reversed by the internal administration of dehydroepiandrosterone alcohol or dehydroepiandrosterone sulfate.
Xeroderma, i.e., dry skin, can be caused by a multiplicity of factors and can be aided by the use of exogenous and water retentive products. I previously found that internal administration of dehydroepiandrosterone alcohol or dehydroepiandrosterone sulfate increases the endogenous production and secretion of natural sebum and enhances the water protective barrier of the skin, thus acting as a natural moisturizer.
Oral ingestion or other systemic administration of dehydroepiandrosterone or its derivatives results in an increase in oil production by all sebaceous glands over the entire body, an effect that is frequently undesirable or unnecessary. The present invention permits obtaining the above-described desirable effects on a localized basis, only at the places where such effects are desired or necessary.
SUMMARY OF THE INVENTION
There has now been discovered a method of treating dry skin in a patient which involves topically administering to the area of dry skin on the patient an effective amount of dehydroepiandrosterone and/or a pharmaceutically acceptable, therapeutically effective derivative thereof. One such derivative of dehydroepiandrosterone is the acetate derivative. Other non-limiting derivatives which may be utilized in this invention include valerate, enanthate, and fatty acid ester derivatives.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of illustrating the invention, there is provided in the drawing a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a graph demonstrating the reduction in mean sebum (oil) secretion in males and females in relation to advancing age.
FIG. 2 is a graph of dehydroepiandrosterone sulfate levels in the blood as a function of age.
FIG. 3 is a pair of bar plots depicting the change in the size of the sebaceous glands of an animal after treatment according to this invention and with various androgens.
FIG. 4 is a bar graph comparing dehydroepiandrosterone at two different dosages causing equivalent responses as certain doses of testosterone and dihydrotestesterone, respectively.
FIG. 5 is a plot of the mean size of the sebaceous gland of the animal ears treated with dehydroepiandrosterone in a gel, untreated ears and control animals treated with the gel without dehydroepiandrosterone, all varying as a function of time.
DETAILED DESCRIPTION OF THE INVENTION
To permit quantitative evaluation of the effectiveness and degree of localization of the topical application of various amounts of the free alcohol form of dehydroepiandrosterone and its derivatives, e.g., acetate, an animal model, hamsters, was chosen that would permit direct examination and quantitation of the size of sebaceous glands as a function of the treatment according to this invention. The use of a hamster ear for sebaceous gland testing was described by Plewig, G. and Luderschmidt, "Hamster Ear Model for Sebaceous Glands", Journal of Investigative Dermatology, 68:171-176 (1977).
Hamster sebaceous glands have been used by numerous medical researchers as an effective and medically accepted animal model for the evaluation of pharmacological products and are directly translatable to their use on human subjects. This model has the advantage of reacting to androgens, estrogens, and other hormones and steroid formulations in a manner closely related to those experienced in the treatment of human beings.
Sebaceous gland cells grow in size as they fill with sebum until they reach full maturity at which point they break open and release their sebum to the surface of the skin. Measurement of sebaceous gland size is thus an effective indicator of the amount of sebum (oil) that is delivered to the surface of the skin. Large glands produce large amounts of sebum, while small glands produce small amounts, thus large glands are associated with oily skin; small glands with dry skin. Hamster ears have sebaceous glands which are readily treatable and easily measured. Accordingly, tests were conducted in which one ear of a hamster was treated with dehydroepiandrosterone (DHEA) and/or a pharmaceutically acceptable, therapeutically effective derivative thereof in a suitable base vehicle while the contralateral ear (the control) was treated with the same base vehicle without the dehydroepiandrosterone (DHEA), and the resultant changes in the gland size of the ear treated with DHEA and the control animal ear were compared.
When the effect of treatment is systemic, both ears will be affected and significant gland size changes will occur on both ears. It is preferred during testing to have a response at the site of application only, e.g., no systemic effect from local application.
The treatment according to this invention was also compared to other known treatments (use of androgens such as testosterone) to produce sebaceous gland enlargement. These other treatments are generally not usable because of their undesirable side effects and systemic action. In the tests used for evaluation, hamsters were treated on one ear with 1% by weight of the free alcohol form of dehydroepiandrosterone in 50 microliters of a suitable vehicle and on the other ear with 50 microliters of the vehicle alone. Similar applications of 1% by weight of various androgens in the same vehicle on other hamsters were used for comparison. A total of 149 hamsters were used to insure statistical validity. Both gel and tincture vehicles were used.
FIG. 3 shows a bar plot of the increase in the size of the sebaceous glands of between about 6 and 10 hamsters per group after treatment with the free alcohol form of dehydroepiandrosterone (DHEA) and with various other androgens. The outer bar in each instance is the ratio of the mean size of sebaceous glands of the treated hamster ear to the mean size of the sebaceous glands of the ears of control hamsters. The inner bar is the ratio of the mean size of sebaceous glands of the untreated contralateral ear of treated hamsters to the mean size of the sebaceous glands of the ears of control hamsters. The scale is on left of the plot.
It can be seen from FIG. 3, that all the androgens tested produced statistically significant systemic effects as measured by the increase of the gland sizes of the contralateral ear (inner bar), while DHEA had no statistically significant systemic effects. In these tests the hamsters were treated once per day for five days a week for two weeks with 50 microliters of a 1% solution (weight/volume) in a tincture vehicle.
FIG. 3 shows the statistically insignificant systemic effect of dehydroepiandrosterone compared to the other androgens tested. The curve interconnecting the points in the center of each bar is a plot of the systemic effect as a percent of contralateral untreated ear sebaceous gland size versus the sebaceous gland size of the treated ear. The percentage scale is on right side of the plot; no systemic effect is at the bottom of the graph corresponding to no increase on the contralateral side and 100% systemic effect is at the top. As is shown, the systemic effect of dehydroepiandrosterone was about 15% (statistically insignificant) whereas all the other androgens tested had systemic effects in excess of 50%.
FIG. 4 shows a bar graph comparing dehydroepiandrosterone ("DHEA") at 1% weight/volume in a tincture vehicle to a dose of testosterone ("testo") (0.1%) causing an equivalent response and dehydroepiandrosterone at 5% weight/volume to a dose of dihydrotestosterone ("DHT") (0.1%) causing an approximately equivalent response. Treatment was once per day for five days a week for two weeks. All values represent the ratio of the mean size of sebaceous glands of treated hamsters to the mean size of sebaceous glands of control hamsters. The outer and inner bars are defined as set forth above for FIG. 3. The scale is on the left of the plot. Only dehydroepiandrosterone showed unilateral performance. The curve (as in FIG. 3 and with its scale on the right) shows the systemic effect of dehydroepiandrosterone as less than 10% (statistically insignificant), whereas testosterone and dihydrotestosterone have systemic effects of over 80%.
FIG. 5 shows a plot of the mean size of sebaceous glands of ears treated once per day for five days a week with dehydroepiandrosterone (1% weight/volume) in a gel vehicle (designated as DHEA), untreated contralateral ears of the same hamsters (designated as contralateral), and control hamsters treated with the gel vehicle without any dehydroepiandrosterone (designated as gel), as a function of the time of treatment. The plot shows that two weeks of treatment produced equilibrium and that the effect on the contralateral ears' sebaceous glands was negligible.
The invention will now be described in further detail by reference to the following specific, non-limiting examples.
EXAMPLES 1-4
These examples concern the preparation of a tincture, topical cream, topical ointment and topical gel, respectively, using vehicles previously used in other preparations and reformulated to optimize the efficacy of the DHEA. The formulations for these preparations are given in the Table hereinbelow.
TABLE__________________________________________________________________________Dehydroepiandrosterone (DHEA) Formulations Example Example Example Example No. 1 No. 2 No. 3 No. 4 Topical Topical Topical Topical Tincture Cream/Lotion Ointment GelIngredients % w/w % w/w % w/w % w/w__________________________________________________________________________ DHEA alcohol 1.0 1.0 1.0 1.0 acetate valerate, etc any fatty acid ester Methyl Paraben NF .01 Propyl Paraben NF .01 Hydroxy Propyl Cellulose (note 1) 1.0 PPG-12-Buteth-16 (note 2) 2.0 Squalane (note 3) 2.0 Glyceryl Monostearate NF 2.0 Stearyl Alcohol NF 2.8 Cetyl Alcohol NF 4.210. Polyethylene Glycol 5.0 Cetyl Ether (note 4) Mineral Oil NF 5.0 Butylene Glycol 4.0 12.0 4.0 Petrolatum USP 5.4 85.0 Alcohol 89.0 47.0 (note 5) Water 6.0 74.4 45.0 100.0 100.0 100.0 100.0__________________________________________________________________________ Notes: (1) available under the trademark Klucel ® from Hercules (2) avaialable under the trademark Ucon ® fluid 50HB from Union Carbide (3) available under the trademark Robane ® from Robeco (4) available under the trademark Brij 58 ® from ICI (5) contains 95% ethanol and 5% water
EXAMPLE NO. 1
Butylene glycol and water were mixed and dissolved into alcohol. The resultant vehicle mixture and DHEA were mixed and dissolved. The resultant formulation was a tincture.
EXAMPLE NO. 2
In this example a topical cream was prepared by first mixing and melting squalane, stearyl alcohol NF, cetyl alcohol, polyethylene glycol cetyl ether, mineral oil NF and petrolatum USP, at 70° C. A second mixture was formed by mixing and dissolving methyl paraben NF and propyl paraben NF in water, at 70° C. The second mixture was slowly added to and mixed with the first mixture to form an emulsion. DHEA was dispersed in the resultant emulsion at 50° C. The resultant composition was slowly cooled with mixing until the composition reached room temperature.
EXAMPLE NO. 3
In this example a topical ointment was prepared. As a first step, glyceryl monostearate was mixed and melted in petrolatum USP at 70° C. As a second step, DHEA was mixed and dissolved in butylene glycol at 70° C. The resultant composition of step 2 was slowly added to the resultant composition of step 1, with mixing. This mixture was then cooled to its congealing point with mixing and then cooled to room temperature without mixing.
EXAMPLE NO. 4
In this example a topical gel was prepared. As a first step, hydroxy propyl cellulose was hydrated and dissolved into water. As a second step, DHEA, butylene glycol and PPG-12-Buteth-16 was dissolved in alcohol. Slowly the resultant mixture of step 2 was added into the resultant mixture of step 1 with mixing until a gel formed.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.
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The severity in incidence of menopausal or age related skin dryness in particular localized areas of the body can be reduced or eradicated by topical administration of effective dosages of the free alcohol form of dehydroepiandrosterone or its derivatives.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Non-Provisional of U.S. Patent Application Ser. No. 60/387,821 filed Jul. 23, 2002.
FIELD OF THE INVENTION
[0002] This invention relates to methods and apparatus for containing and processing small objects and more particularly, although in its broader aspects not exclusively, methods and apparatus for performing protein purifications manually, semi-automated, and fully automated operations.
BACKGROUND OF THE INVENTION
[0003] Understanding gene function has become a major focus of life science and biotech/pharmaceutical research, and understanding proteins is central to understanding gene function. Numerous techniques may be used to purify proteins for analysis. See, for example: Protein Purification Techniques: A Practical Approach by Simon Roe (Editor, 2nd edition (April 2001) Oxford University Press; ISBN: 0199636745; Protein Purification: Principles and Practice by Robert K. Scopes, 3rd edition (January 1994) Springer Verlag; ISBN: 0387940723; and Protein Analysis and Purification: Benchtop Techniques by Ian M. Rosenberg, 1st edition (September 1996) Springer Verlag; ISBN: 0817637176.
[0004] Life science and the study of proteins requires high throughput techniques. Immunoprecipitation and other affinity methods for protein activities require new tools to provide the needed high throughput. High throughput expression and purification of proteins is important in several areas of research, including in vitro study of protein-protein interactions, the study of protein complexes, high throughput screening of small molecule ligands against protein targets, creation of protein arrays, and high throughput structural genomics (protein structure via NMR and/or X-ray crystallography). These activities are performed in biotechnology and pharmaceutical companies, as well as in academic research.
SUMMARY OF THE INVENTION
[0005] The present invention is a general purpose consumable/disposable plate or custom pipette tips that facilitate the handling of many small objects. The invention may be used to advantage with any available solid-phase purification protocol, latex bead-based protein purification being just one example. When used in combination with robotic handling, the invention is well-suited to high-throughput research applications
[0006] In a preferred embodiment of the invention, a plate is fabricated to define a plurality of wells or cavities having a permeable bottom or sidewalls for holding small objects such as affinity beads to which the proteins in a lysate become bound. During purification, the wells may be immersed in the lysate one or more times until the binding of the protein to the affinity beads is complete. A flow of wash solution is then passed through the beads and through the permeable walls of the wells to wash the beads. A flow of elution solution may then be passed through the beads and the well walls to complete the purification process before the purified sample is collected. The well may be constructed of any inert material which will not affect the analysis being performed. A substantial portion of the bottom and/or lower sidewall of the web should be permeable to the liquids brought into contact with the beads or other material used to perform the analysis, but should retain the beans or other material during the analysis.
[0007] The invention provides a dramatic reduction in labor when purification is performed manually and further enables automated, unattended purification to be performed with high throughput. The technique is also applicable to situations where a number of small objects need to be contained and exposed to different fluids. Examples include protein purification where beads are used, and larvae and embryo staining. The technique is compatible with existing infrastructures for both manual and robotics applications. The consumable and disposable plates contemplated by the invention may be used to advantage in the high-throughput purification of proteins and for immunoprecipitation.
[0008] These and other objects, features and advantages of the invention will be made more apparent by considering the following detailed description of an embodiment of the invention and its applications. In the course of this description, frequent reference will be made to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a flow chart and schematic illustration of the method of performing protein purification using affinity beads which are held in flow-through perforated wells as contemplated by the invention.
[0010] FIG. 2 is a perspective view of a 96-well plate constructed in accordance with the invention;
[0011] FIG. 3 is a perspective view of a 96 vessel plate for holding liquids into which the column plate of FIG. 2 is inserted; and
[0012] FIG. 4 is a cross-sectional view showing a well with a permeable bottom holding affinity beads inserted into liquid holding vessel.
DETAILED DESCRIPTION
[0013] An illustrative embodiment of the invention used to perform high throughput protein purification by affinity methods is shown in FIG. 1 .
[0014] As contemplated by the invention, one or more wells or cavities having liquid permeable side walls are first filled with affinity beads, such as beads coated with Ni++ for binding proteins tagged with 6× Histidine; beads coated with Glutathione (GLT) for proteins tagged with Glutathione-S-transferase (GST); or beads coated with avidin (monomeric and therefore reversible) for purifying proteins tagged with Biotin; or Immunoprecipitation (beads with either protein A or G) to which an antibody is immobilized to enable binding a protein of interest.
[0015] After the wells are filled as indicated generally at 11 , they are immersed in lysate solution as indicated at 12 and then removed as seen at 14 . When immersed, the lysate flows inwardly into the well through the liquid permeable side walls and/or permeable bottom of the well. When the well is then removed at 14 , the lysate is allowed to drain outwardly through the side walls and/or bottom of the well. If the binding of the protein to the affinity beads is not complete, the process is repeated by again immersing the well and the beads in the lysate as seen at 15 , and again removing the well from the lysate and allowing it to drain as seen at 17 .
[0016] The process of immersing and then draining the well is repeated until the binding is complete, as determined by the test seen at 20 . A wash solution is then allowed to flow over the beads and through the sidewalls and/or bottom of the well as seen at 22 . Alternatively, the plate can be repeatedly dunked in a wash basin.
[0017] After the beads are washed, an elution solution is flowed over the beads and through the permeable sidewalls/bottom of the well as seen at 24 before the purified sample is collected as seen at 30 . The elution step can also be performed to collect sample fractions.
[0018] The total up/down time allotted for binding is determined by the protocol for protein purification using the chosen beads with the well being immersed again each time as soon as it is drained. The act of immersing the well serves to mix the contents of the well (the lysate in the wells and the beads) to promote better binding.
[0019] The well which holds the beads is formed such that all or a substantial portion of the bottom of the well is permeable by the liquids that are brought into contact with the beads, including the lysate, the wash solution and the elution buffer. The well may, for example, be formed into a cylindrical or frustoconical cavity with a bottom formed by a 30 micrometer mesh which permits the passage of liquids but not the beads which have a diameter in excess of 30 micrometers. Although the sidewalls of the well may be permeable in addition to or instead of employing a permeable bottom, it has been found that making the bottom permeable and using non-permeable sidewalls provides better mixing and washing than is achieved with permeable sidewalls. The well should be constructed of materials which are inert and hence do not effect the materials being handled. Polypropylene may be used for the sidewalls of the wells and the bottom may be a polyester mesh.
[0020] The mesh opening should be as large as possible subject to the constraint that it must contain the beads. The prototype devices proved workable with 25, 33 and 41 micron openings in a woven mesh so these were the real sizes. Note that the beads are not of uniform size and the mesh opening should to be at the low end of the range of possible bead diameters to contain substantially all of the beads. Filter materials other than woven mesh may be used provided the openings are large enough to permit flow by gravity yet sufficiently constricted to retain the small objects being processed
[0021] Purification of protein samples is a fundamental need in the field of proteomics and is a basic requirement in a wide variety of academic, clinical, and industrial programs. With the recent advancements in the field of genomics there is an increasing need to express and purify large number of the proteins at the same time. Traditional methods of protein purification are not well suited for high throughput applications. The embodiment of the invention shown in FIGS. 2-4 facilitates the rapid purification of proteins in a high throughput format.
[0022] Preferably, a plurality of such wells are held by a single support member, such as the column plate 50 seen in FIG. 2 to which 96 wells indicated generally at 55 are attached. All of the wells 55 attached to the column plate 50 are filled with beads and all are immersed, drained, washed and eluted at the same time to provide a 96-fold increase in the throughput of the system. Alternatively, a plurality of wells arranged in one or more rows may be affixed to a handle and manually, and a plurality of wells may be used in conjunction with a custom workstation or in an automated liquid handling robotic system. In an automated system, the number of times the wells 55 are inserted into vessel containing a liquid, as well as the duration during which the wells are immersed and the duration during which they are allowed to drain, can be precisely controlled to achieve the desired degree of binding. The dipping of the well into a wash or elution buffer during the washing and elution steps can also be timed under program control or, in the alternative, wash or elution buffers may be automatically dispensed in measured amounts into the well from above and allowed to drain through the well into either a plate to catch the elution or waste for wash buffer.
[0023] Each of the wells 55 can be inserted into the liquid held in one of the corresponding 96 vessels in a well block 58 shown in FIG. 3 . As shown in FIG. 4 , each well 60 should be sized and shaped such that it nests into a vessel 70 used to grow the cells that are expressing the proteins. The interior of each vessel in the well block 58 that contains the liquid is larger than, but similar in size to, the exterior of the well holding the small objects so that, when each well is inserted into the corresponding vessel, the level of said liquid in the vessel is displaced to a substantially higher level to increase the liquid pressure at the bottom of said well, increasing the flow rate of the liquid as it is forced upwardly through the permeable bottom of the well. Each well 60 is partially filled with affinity beads as shown at 75 . A 40 uM polyethylene mesh 80 attached to the bottom of each well 60 and supports the beads 75 while allowing liquid in the vessel 70 to flow into and out of the well 60 as the well 60 is repeatedly inserted into and withdrawn from the vessel 70 . The mesh 80 allows free flow of sample and buffers into and out of the column of while retaining the affinity media. The column plate nests into a standard 96 well deep well plate.
[0024] This platform can be utilized to capture proteins by affinity resins or to deplete samples thereby concentrating the specific protein of interest. The embodiment of the invention shown in FIGS. 2-4 was tested to purify His tagged Green fluorescent protein expressed in E. coli using the TALON Cell Thru resin. The cells can be grown, pelleted and lysed in the same well block. The affinity purification using the TALON beads in the column plate was straightforward and the whole process of binding, wash and elution could be performed in less than 20 minutes. There was no requirement for filtration plates or vacuum manifolds.
[0025] As an example, E. coli (BL21-SI, Invitrogen) alone or expressing pGFPuv (available from Becton, Dickinson and Company, BD Biosciences Clontech) were grown on LB agar w/Ampicillin selection (100 μg/ml) at 37° C. Colony picked and added to 800 μL of LB liquid media in each well of a 96 well deep well block. IPTG was added to 1 mM to induce expression of GFP. The OD600 is adjusted to 1.5 and the block is spun to pellet the cells. TALON immobilized metal affinity resin (also from available from BD Biosciences Clontech) was used to purify 6x-His tagged GFP. 50 μL of TALON was equilibrated w/lysis buffer and added to each well of the Column plate (slide 8).
[0026] Three additional deep well blocks were prepared for the wash step w/400 μL of wash buffer in each well. One deep well block for elution was prepared w/400 μL of the elution buffer in each well.
[0027] In the extraction of protein, bacterial pellets were resuspended in the lysis buffer and kept at room temperature for 15 minutes. The lysate was centrifuged (in the plate) at 10,000 rpm for 5 minutes.
[0028] In the binding step, the 96 well column plate containing the TALON resin was repeatedly dipped in the supernatant samples and then transferred to the plates containing the wash buffer. Each dipping cycle consumed 32 seconds: 30 seconds in the lysate and 2 seconds out of lysate allowing the wells to drain.
[0029] Washing was done by dipping the plate 6 times in a 96 well block containing 400 μl of wash buffer. The dipping cycle was 32 seconds: 30 seconds in the wash buffer and 2 seconds out of the wash buffer. This step was repeated in the three plates containing the wash buffer.
[0030] In the elution step, the column plate was transferred to the well block containing the elution buffer and dunked for 4 minutes (the elution dipping cycle was 32 seconds: 30 seconds in the elution buffer and 2 seconds out of the elution buffer.
[0031] The samples from the different purification steps were analyzed by SDS PAGE.
[0032] When the insert plate was dipped in the sample plate for various residence times, the results suggested that the optimal binding can be achieved within 4 to 6 minutes.
[0033] To determine the effect of sample dilution, bacterial cell lysate was diluted with extraction buffer to various volumes in the deep well plate. The total protein amount was kept the same in each well. The results suggest that purification is dependent on the sample concentration. The purity of the eluted sample improves as the dilution of the cell lysate increases.
[0034] The methods and apparatus contemplated by the invention allow the user to rapidly purify proteins in a high throughput format on small samples in a short interval of time without the need of elaborate filtration steps or use of vacuum manifolds and the method is compatible with existing automation equipment.
[0035] In an automated system, pressure and/or centrifugal force may be applied to speed flow rates and the wells may be agitated to improve mixing. However, it has been found that excellent performance may be achieved without increasing the cost of and complexity of the system by employing such techniques. Employing a pressure assisted device when the invention is employed in a custom manual pipetting device should not, however, have any significant cost impact and it could be expected to improve the performance of the device.
[0036] The principles of the invention may also be used in the processing of other kinds of small objects intermixed with other kinds of liquids. For example, small organisms, such as embryos, larvae, or the like that are being stained or otherwise washed/treated with a pharmaceutical, or being exposed to a set of biochemical conditions (e.g. liquids with varying pH, temperature, concentration of salt or similar conditions).
[0037] The invention may also be used for immunoprecipitation (IP). In an IP, affinity tagging is accomplished by attaching an antibody to protein A or protein G which have been immobilized on the beads placed in the well. The beads in the permeable wells are intermixed as described above with a liquid containing an immunoprecipitating antibody. The optimal amount of antibody that will quantitatively immunoprecipitate the protein of interest, as well as the mixing time and the incubation time, should be empirically determined for each cell model. Using the invention to perform immunoprecipitation provides an efficient analytical method for pulling out the protein of interest, and anything else that may be bound to the protein of interest.
CONCLUSION
[0038] It should be understood that the methods and apparatus which have been described are merely illustrative applications of the principles of the invention. Numerous modifications may be made to the arrangements described without departing from the true spirit and scope of the invention.
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Methods and apparatus for intermixing small solid objects and a liquid employed in a platform useful for affinity purification of protein samples in a high throughput format. The system handles up to 96 samples at a time and provides thorough mixing of affinity media with a lysate solution containing the protein samples which accelerates interaction between the media and the sample. Sample processing times are shortened and in some cases non-specific contamination is reduced.
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FIELD OF THE INVENTION
The present invention relates generally to an apparatus that diverts gray water from a washing machine to landscape or a sewer drain based on analysis from sensors.
BACKGROUND OF THE INVENTION
In many climates around the world, especially those that are arid, water conservation and water recycling are important tools in mitigating the problem of limited fresh water resources. As understood herein, fresh water can be conserved by using household wastewater, known as “gray water”, which can come from household effluent drains. As also understood herein, however, the amount of impurities and turbidity of the gray water can in part affect the type of application and ability for reclamation and gray water's use in recycling.
Present principles further recognize the desirability of eliminating costly components such as sump pumps from reclamation systems. It is also desirable according to present principles to reduce the risk of blockage and clogging such as might be encountered in recycling devices that integrate with pre-existing irrigation facilities, such as drip lines, sprinkler heads etc.
A critical recognition is that gray water may contain harmful constituents that can be toxic to plants, inhibit seed-germination, and destroy the structure of clay soils. Present principles recognize that the identification and removal of substances within gray water can prove to be beneficial in determining whether said gray water is suitable for use in irrigation systems.
SUMMARY OF THE INVENTION
As understood herein, there is a need for a method and apparatus that allows a typical household to identify, reclaim, and recycle gray water without expensive remodeling of existing structures, and intensive construction installation.
Accordingly, in one aspect an apparatus includes an electrically-positioned three way diverter valve having an inlet in fluid communication with an effluent (e.g., gray water) line (e.g., pipe) of a household appliance (e.g., a washing machine), a sewer outlet in fluid communication with a public sewage system, and an irrigation outlet in fluid communication with an irrigation pipe. The three-way diverter valve may have a sewer position wherein the inlet is in fluid communication with the sewer outlet and an irrigation position wherein the inlet is in fluid communication with the irrigation outlet. In example embodiments the diverter valve is positioned in the effluent pipe substantially at about the same height, e.g., within six to eight vertical inches, as the effluent outlet port of the appliance to minimize stress on a pump motor that may be associated with the appliance.
At least one sensor senses at least one characteristic of effluent from the household appliance and at least one processor receives signals from the sensor and responsive thereto establishing a position of the three-way valve. At least one characteristic of the effluent may include temperature and/or a predetermined chemical. Additionally, the processor may include receiving and transmitting a signal to and/or from a mobile communication device. The processor may execute logic to receive a signal from the mobile communication device and use the signal from the mobile communication device, along with the signals received from at least one sensor that senses at least one characteristic of effluent from the household appliance, to establish and relay back to the mobile device, e.g., the current status of at least one characteristic of the effluent and/or the position of the three-way valve. The processor may further execute logic to electrically control the position of the three-way valve based on signals received from a mobile communication device.
Without limitation, a sensor may include a temperature sensor with the irrigation position established responsive to a determination that temperature of the effluent is no more than a threshold temperature. Likewise, a sensor may also include, in addition to or in place of a temperature sensor, a chemical sensor that senses a concentration of a predetermined chemical in the effluent and the irrigation position is established responsive to a determination that the concentration of the predetermined chemical in the effluent is no more than a threshold concentration. The irrigation position may be established responsive to both a determination that the concentration of the predetermined chemical in the effluent is no more than a threshold concentration and also responsive to a determination that temperature of the effluent is no more than a threshold temperature. The predetermined chemical includes chlorine. The threshold concentration includes 200 p.p.m. (parts per million) or approximately 5.25 percent per gallon of effluent. The threshold temperature includes 145 degrees Fahrenheit (approximately 62.7 degrees Celsius).
The apparatus may further include a check valve and/or an anti-siphon valve in the irrigation pipe to permit only one-way flow from the three-way valve through the irrigation pipe and/or include a particulate filter in the irrigation pipe to filter particulate matter in the effluent. The apparatus may also include a volumetric flow meter to display and measure average effluent fluid flow rates, and/or volumetric effluent fluid values for momentary, and/or accumulative (total volume units) usage totals. The household appliance may be a washing machine that includes a pump, which in example embodiments can supply approximately thirty pounds per square inch to thirty five pounds per square inch (30 p.s.i. to 35 p.s.i.) of effluent fluid pressure to a horizontal radius of up to and including one hundred feet. Effluent pressure in an effluent pipe of, e.g., an inch in diameter, may be measured.
In another aspect, a method includes receiving at least one signal representing a predetermined characteristic of effluent (e.g., gray water) from a household appliance (e.g., a washing machine), and based at least in part on the signal, positioning a valve to divert the effluent to a public sewage system or to an irrigation pipe. The valve may be manually and/or electrically positioned. The predetermined characteristic includes temperature and/or a chemical concentration. The chemical concentration includes a chlorine concentration. The chlorine concentration may have a threshold concentration, which includes 200 p.p.m. (parts per million) or approximately 5.25 percent per gallon of effluent. The temperature may have a threshold temperature, which includes 145 degrees Fahrenheit (approximately 62.7 degrees Celsius).
In another aspect, an assembly includes a three-way valve having an inlet in fluid communication with an effluent (e.g., gray water) line (e.g., pipe) of a household appliance (e.g., a washing machine), a sewer outlet in fluid communication with a public sewage system, and an irrigation outlet in fluid communication with an irrigation pipe. The three-way valve includes having a sewer position wherein the inlet is in fluid communication with the sewer outlet and an irrigation position wherein the inlet is in fluid communication with the irrigation outlet. The three-way valve may additionally include at least one indicator light having a first visual appearance when the three way valve is in the sewer position and a second visual appearance when the three way valve is in the irrigation position. An indicator light includes a light emitting diode (LED). A first visual appearance may include e.g., a blinking LED, and/or a change in LED color, and/or a change in illuminating light intensity. A second visual appearance may include e.g., a blinking LED, and/or a change in LED color, and/or change in illuminating LED light intensity.
The assembly may further include at least one sensor sensing at least one characteristic of effluent from the household appliance, and at least one processor receiving signals from the sensor and responsive thereto establishing a position, of the three-way valve. At least one characteristic of the effluent may include temperature and/or a predetermined chemical. Without limitation, a sensor includes a temperature sensor and the irrigation position is established responsive to a determination that temperature of the effluent is no more than a threshold temperature. A sensor may also include, in addition to or in place of a temperature sensor, a chemical sensor that senses a concentration of a predetermined chemical in the effluent and the irrigation position is established responsive to a determination that the concentration of the predetermined chemical in the effluent is no more than a threshold concentration. The irrigation position may be established responsive to both a determination that the concentration of the predetermined chemical in the effluent is no more than a threshold concentration and also responsive to a determination that temperature of the effluent is no more than a threshold temperature.
The predetermined chemical includes chlorine. The threshold concentration includes 200 p.p.m. (parts per million) or approximately 5.25 percent per gallon of effluent. The threshold temperature includes 145 degrees Fahrenheit or approximately 62.7 degrees Celsius.
The assembly may further include a check valve and/or an anti-siphon valve in the irrigation pipe to permit only one-way flow from the three-way valve through the irrigation pipe and/or include a particulate filter in the irrigation pipe to filter particulate matter in the effluent. The assembly may also include a volumetric flow meter to display and measure average effluent fluid flow rates, and/or volumetric effluent fluid values for momentary, and/or accumulative (total volume units) usage totals.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing an example system in accordance with present principles; and
FIG. 2 is a flow chart of logic in accordance with present principles.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1 , a system is shown, generally designated 10 , which includes a household appliance 12 such as a washing machine, dishwasher (preferably when in a jurisdiction that classifies dishwasher effluent as gray water), or other water-discharging appliance which receives water through an influent pipe 14 from a water source 16 such as a municipal potable water supply. An influent isolation valve 18 may be disposed in the influent pipe 14 to selectively block the influent pipe 14 .
As shown, the household appliance 12 has a gray water discharge port 12 in fluid communication with an effluent pipe 20 . The effluent pipe 20 is in fluid communication with a three-way diverter valve 22 . In some examples the diverter valve 22 is manually operated, but in the embodiment shown the diverter valve 22 is a solenoid valve that is electrically controlled in accordance with principles discussed further below. In example implementations the diverter valve 22 may be a two-position ball valve the position of which is controlled by an electronic and/or hydraulic solenoid responsive to logic set forth further below.
With more specificity and as can be appreciated in reference to FIG. 1 , the diverter valve 22 is movable between a sewer position, in which the discharge of the appliance 12 is in fluid communication with a sewage pipe 24 that leads to a sewage system 26 such as a septic tank or public sewer system, and an irrigation position, in which the discharge of the appliance 12 is in fluid communication with an irrigation pipe 28 for purposes to be shortly disclosed. It is preferred that the diverter valve 22 establish fluid communication between the discharge of the appliance and either the sewage pipe 24 or irrigation pipe 28 , but not both simultaneously, although in some implementations the diverter valve 22 may be configured to maintain an intermediate position between the sewer position and the irrigation position.
FIG. 1 shows that if desired, a flow meter 30 may be disposed in the irrigation pipe 28 to provide an indication of the existence and/or volume of water flow through the pipe 28 . Also, an anti-siphon valve 32 may be disposed in the irrigation pipe 28 downstream of the flow meter 30 to prevent siphoning of fluid through the pipe 28 toward the diverter valve 22 . If desired, a check valve 34 may also be disposed in the irrigation pipe 28 downstream of the anti-siphon valve 32 to ensure that fluid may flow through the pipe 28 only away from the diverter valve 22 . In some embodiments the check valve 34 may be a swing check-valve that can also serve also as a filter to remove particulates that are too large to pass through the check valve. A clear check-valve with a one inch diameter pipe may be used so that lint and/or other debris can be seen. Also, a filter 36 may also be disposed in the irrigation pipe 28 downstream of the check valve 34 to remove particulate matter from fluid flowing therethrough. The order of components in the irrigation pipe 28 is not limiting.
Downstream of the components in the irrigation pipe 28 is an outlet 38 through which gray water can flow to land surrounding the house in which the appliance 12 is disposed to irrigate the land. While only a single irrigation pipe 28 is shown for clarity it is to be understood that the pipe 28 may be established by multiple pipe segments joined together and may also include branch lines in some examples.
When the diverter valve 22 is solenoid controlled, the solenoid of the diverter valve 28 receives position signals from a processor 40 accessing instructions contained on a non-transitory computer readable storage medium 41 in accordance with logic discussed further below. Without limitation, the storage medium may be embodied by disk-based or solid state storage.
The processor 40 with storage medium 41 may be contained in a control panel assembly 42 which may be integrated with the appliance 12 or housed separately therefrom. In any case, the example control panel assembly 42 may include a control switch 44 which is manipulable to activate or deactivate the logic below. When deactivated, the diverter valve 22 can be in the sewer position.
Additionally, the control panel 42 can include indicator lamps which may be established by light emitting diodes (LED) of various colors. In the embodiment shown, the control panel assembly 42 includes a chemical indicator lamp or display 46 which, when illuminated, indicates that the concentration of a predetermined chemical in the effluent pipe 20 is above (or below) a threshold or which may indicate the numeric concentration. Also, a temperature indicator lamp or display 48 may be provided to indicate temperature of fluid in the pipe 20 or to give a numeric presentation of the temperature. Status lamps 50 , 52 may also be provided respectively indicating, when illuminated, that the diverter valve 22 is in the sewer and irrigation positions. The lamps shown in FIG. 1 may also blink or assume differing intensities to indicate various conditions such as overly high temperature in the effluent pipe 20 , overly high chemical concentration in the pipe 20 , etc.
Completing the description of FIG. 1 , various sensors may be in fluid communication with the effluent pipe 20 to communicate signals to the processor 40 . In the embodiment shown, a chemical sensor assembly 54 and a temperature sensor assembly 56 are provided which respectively generate signals representative of a chemical concentration and temperature of fluid in the pipe 20 . In one example, the chemical sensor 54 is a chlorine sensor. Additional sensors may be provided if desired. Each sensor assembly 54 , 56 may include a wired or wireless transmitter that sends signals to the processor 40 . The processor 40 may also communicate with a mobile communication device 58 either wired or wirelessly, e.g., to receive control signals from the communication device 58 such as signals activating present logic, deactivating the logic, illuminating one or more lamps for test, etc.
FIG. 2 shows example logic in accordance with present principles. Responsive to the control switch 44 being turned to the “on” position at block 60 , the logic periodically begins at state 62 . Signals from one or more of the sensors 54 , 56 are received at block 64 . Recall that the signal from the chemical sensor 54 represents the concentration of a particular chemical or chemicals in the effluent from the appliance 12 and the signal from the temperature sensor 56 represents the fluid temperature of the effluent from the appliance 12 . In example shown, both temperature and chemical composition in the effluent pipe 20 are tested for, it being understood that only one or the other test may be executed in some embodiments. Also, although FIG. 2 shows that temperature is tested first and then chemical composition, the order of the tests may be reversed.
Proceeding to decision diamond 66 , it is determined whether the temperature of fluid in the effluent pipe 20 exceeds a predetermined threshold. In an example non-limiting embodiment the threshold is at least fifty degrees Celsius (50° C.) and more preferably is 62° C. Responsive to a determination that temperature is below the threshold, the logic flows to decision diamond 68 wherein it is determined whether the concentration of the predetermined chemical in the effluent pipe 20 exceeds a threshold concentration. In an example embodiment the chemical is chlorine and an example threshold is two hundred parts per million (200 ppm).
Responsive to a determination that the chemical composition is below the threshold, the logic moves from decision diamond 68 to block 70 , wherein the processor 40 causes the diverter valve 22 to be configured (or to remain configured, if already so positioned) in the irrigation position, such that effluent from the appliance 12 is directed to the irrigation pipe 28 . Proceeding to block 72 , the irrigate lamp 52 is configured (e.g., by keeping it constantly illuminated it or by blinking it on and off) to indicate that the effluent is being directed to landscaping; otherwise, the irrigate lamp is not so configured.
In contrast, responsive to a determination at decision diamond 66 that the temperature of the effluent exceeds the threshold, the logic moves from decision diamond 66 to block 74 to configure the sewer lamp (e.g., by keeping it constantly illuminated or by blinking it on and off) to indicate that effluent is being directed to the sewage system or septic tank. Likewise, the high temperature lamp 48 is configured (e.g., by keeping it constantly illuminated or by blinking it on and off) to indicate that effluent temperature is too high for irrigation.
From block 74 the logic proceeds to decision diamond 76 , wherein it is determined whether the concentration of the predetermined chemical in the effluent pipe 20 exceeds the threshold concentration. Positive tests from decision diamonds 76 and 68 cause the logic to flow to block 78 , wherein the high chemical lamp 46 is configured (e.g., by keeping it constantly illuminated or by blinking it on and off) to indicate that chemical concentration in the effluent is too high for irrigation. The logic then moves from block 78 to block 80 to configure (or maintain it configured, if already so positioned) the diverter valve 22 in the sewer position. As mentioned above, the logic of FIG. 2 can be periodically repeated.
While the particular GRAY WATER RECYCLING APPARATUS, METHOD, AND ASSEMBLY is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.
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Instead of disposing gray water with sewage water, a gray water recycling apparatus uses a series of sensors and determines the acceptability of chemical concentrations and temperature of the gray water for use in irrigation purposes so as to ensure the recycled gray water is safe for irrigation. If it is, a three-way valve is positioned to direct the gray water to an irrigation pipe; otherwise, the three-way valve is positioned to direct the water to a public sewage system or septic tank.
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BACKGROUND OF THE INVENTION
This invention relates to an induction heating coil for the crucible free melting of crystalline material and more particularly to an induction heating coil that is suitable for the float zone melting of large, high quality crystals of semiconductor material.
Float zone melting is used to convert polycrystalline material to high quality monocrystalline rod, to remove unwanted impurities from the material, and simultaneously to distribute dopant atoms uniformly throughout the crystal. In the float zone process a narrow molten zone is caused to move slowly along the length of a vertically disposed rod of the crystalline material. As the molten zone moves, the material immediately behind the zone can be made to resolidify as monocrystalline material. The monocrystalline growth is initially nucleated by a single crystal seed and then continues in a self-seeding manner. Also, as the molten zone moves, it sweeps impurities with it and distributes dopant atoms, leaving the material behind the zone in a more pure and uniformly doped state.
The molten zone is caused to traverse the length of the polycrystalline rod by moving the rod vertically past a stationary heating means such as an RF induction coil surrounding the material. This molten zone is unsupported, being held in position only by surface tension and electromagnetic forces. Because the zone has no support means such as contact with the walls of a crucible, the size and shape of the zone are extremely critical. If the zone becomes too large, the electromagnetic and surface tension forces will be unable to confine the large amount of molten material and the molten material will spill under the influence of gravity. Conversely, if the molten zone is of too limited extent, the central portion of the material may not be completely melted, resulting in poor crystal quality. The critical shaping of the molten zone is controlled by the distribution of current induced in the rod, and this, in turn, is controlled primarily by the shape and design of the induction coil used to form that zone. A wide variety of coils have been tried, including both single turn and multiple turn coils. The latter may have the multiple turns in parallel or it may be helical shaped. The coils may be formed of cylindrical tubing or may be milled in a "pancake" shape. All of the various geometries are designed to distribute the current in such a way as to provide the necessary heating to the total cross section of the rod and to stabilize the melt. These various coil designs have not proved to be totally satisfactory, especially with large diameter crystals. For example, a commonly used coil is made of two parallel turns of tubing. One of the turns is smaller than and positioned above the other. This configuration of concentric coils helps to support and stabilize the melt, and ensures that the entire cross section of the material is molten. Coils formed from cylindrical tubing, however, are difficult to shape precisely, and can easily be bent out of the desired shape, especially when the coil is new and the coil material is soft. Additionally, the current must, of course, be confined to the turns of the coil and thus the current is distributed in discrete steps. The current, therefore, can not be smoothly varying from top to bottom of the molten zone.
Flat pancake style coils can be milled from a piece of solid stock, and can therefore be produced to tight dimensional tolerances. Such coils are also more substantial and rugged than the coiled tubing type and thus are less susceptible to accidental deformation. But the pancake coils have less flexibility of design because the currents are carried equally by all surfaces of the coil.
Accordingly, a need existed for an improved radio frequency induction coil for the float zone melting of crystalline materials which would overcome the problems inherent in the prior art coils.
BRIEF SUMMARY OF THE INVENTION
It is a primary aim of this invention to provide a radio frequency induction coil that can be easily and reproducibly fabricated. The current distribution through the RF coil can be adjusted to alter the resultant induced current and thus the temperature distribution in the rod of material to be refined. The adjustments in the current distribution in the coil can be made independently on the top and bottom surfaces of the coil.
The float zone induction coil in accordance with the invention is milled from a solid piece of conductor material in the shape of a flat "pancake" coil. A shallow groove is milled in the coil to accept a piece of tubing which is welded or soldered into the groove to provide water cooling for the coil. The current distribution through the coil is then determined by sawing slots in the surface of the coil. The saw slots serve to steer the current, confining the current to those areas of the coil which do not have saw slots. The current distribution on the top and bottom surfaces of the coil can be determined independently by the particular array of saw slots on each surface. Once a given array of saw slots has been established, it can be changed or further altered by milling a groove in the surface of the coil and inserting a solid piece of conductor in the groove. The solid piece can replace, and thus cancels out, the effect of the saw slots. Alternatively, a solid piece of conductor can be welded or otherwise affixed to the surface of the coil to either cancel the effect of the underlying saw slots or to enhance the current carrying capability of that particular localized portion of the coil.
The objects of the invention and the benefits to be derived therefrom should be more readily apparent after review of the following more detailed description of the invention taken in connection with the drawings.
DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of one type of prior art induction heating coil.
FIG. 2 is a side view of an induction heating coil in accordance with the invention.
FIGS. 3 and 4 are top and bottom views of the induction heating coil.
FIG. 5 is a perspective view of a further embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows one of the typical prior art coils 10. It consists of two concentric coils, a smaller top coil 12 and a larger bottom coil 14. The coils 12, 14 could be formed from copper tubing or other suitable conductor material. The two coils are joined together at junction 16 so that the two coils are electrically in parallel. The common ends 17, 19 of the coil are connected both to a source of radio frequency power and to a water cooling system. Water flows through the hollow tubing of the coils to keep the coils cool, since they will be in close proximity to the molten crystalline material. The two coils ensure that sufficient energy is coupled to the crystalline material to melt the entire cross section of the material. The smaller coil 12 inductively couples with the central portion of the melt while the larger coil 14 couples to the outer portion of the melt to establish a reasonably shaped freezing interface. The two coils 12, 14 act together to stabilize the melt; with only a single turn, the growing crystal tends to spiral off in an uncontrolled direction.
Turning now to FIG. 2, there is shown in cross section a radio frequency (RF) induction coil 18 in accordance with the invention. Coil 18 is shown together with a silicon rod being float zone refined. The preferred embodiment is herein described for the float zone refining of a silicon rod of a particular size. A polycrystalline feed stock rod 20 about 50-80 millimeters in diameter is converted by the crucible free refining process to a single crystal rod 22 that is about 75-110 millimeters in diameter. It will be appreciated that this is just a single particular example to illustrate the invention. Those skilled in the art will understand that appropriate modifications can be made within the spirit of the invention for the zone refining of other materials and other sizes. The molten zone 24 of the silicon material necks down to a smaller diameter to pass through the center of the coil 18. The molten zone is heated by currents induced in the rod by the induction coil. The coil can be, for example, about 10-15 millimeters in thickness at its outer edge and taper to a few tenths of a millimeter thickness at the center.
FIG. 3 shows a top view of the induction coil 18. The coil 18 can be machined from copper, silver, or other conductive material stock. The outer diameter of coil 18 can be, for example, about 90-140 millimeters and the inner diameter can be about 20-35 millimeters, with the opening being circular, oval, or otherwise shaped. A gap 26 is cut in the toroid shaped coil 18 so that the coil forms a single turn substantially surrounding the crystalline material. To provide cooling for the coil, a slot 28 shown by the dotted lines, is milled in the surface of the coil. Into this slot is pressed a piece of tubing 29 having ends 30 and 32. The tubing can be, for example, 5 millimeter diameter copper tubing. The tubing is silver soldered or welded into the slot 28 and the surface of the coil 18 is ground smooth. In use, the ends 30, 32 of the copper tubing are connected to a source of flowing water and also to an RF power source, neither of which is shown. The water cooling is required to keep the coil 18 from melting as the result of the high currents on the coil surface.
Current flows in the coil 18 from the RF power generator. The current distribution in the coil can be controlled by selectively sawing a number of slots 34 in the surface of the coil. By controlling the current distribution, it is possible to control the electrical field pattern and thus the distribution of the current induced in the silicon rod. At the radio frequency of interest in float zone melting (about 2-5 MHz) the skin depth in copper is less than 0.05 millimeter and thus substantially all of the current flows on the surface of the coil. Thus a saw slot 34 of about 1 millimeter width and 1-2 millimeters depth is effective in locally increasing the electrical impedance. It has been determined that about 20-50 radially directed saw slots 34 on the upper surface of the coil are effective in properly controlling the current distribution. These can be uniformly spaced about the circumference of the coil or can be asymmetrically arranged to provide a particular distribution. To heat the central portion of the feed stock rod 20, and to help stabilize the melt, the saw slots 34 on the top surface of the coil 18 can be located towards the outer periphery of the coil and can extend over the edge of the coil, with the inner part of the coil free from saw slots. This arrangement of slots 34 forces the current to the center of the coil and leaves the outer portion of the coil relatively current free. The saw slots 34 can extend, for example, from about 80 millimeters from the center of the coil to the outside edge of the coil.
The bottom of the induction coil 18 is shown in FIG. 4. The current distribution on this surface of the coil is established, in a manner similar to the top surface, by sawing slots 36 in the surface of the coil 18. The saw slots 36 on the bottom surface of the coil need not be identical to the saw slots 34 on the top surface of the coil. Thus the current distributions on the top and bottom of the coil can be adjusted independently. For the particular example described, it has been found expedient to saw 30-40 evenly spaced, radial slots extending from about 20 millimeters from the center of the coil to about 40 millimeters from the center. The current is thus confined to the inner and outer portions of the bottom of the coil 18 and is excluded or reduced in the central portion.
FIG. 5 again shows a float zone induction coil 18 having a saw slots 34 in the top surface for establishing a particular current distribution. In addition to the saw slots, however, an additional technique is employed for changing the current distribution. The saw slots are used to increase the surface impedance in certain regions of the coil; in the alternate technique the impedance is lowered by welding solid conductor strips 38 to the surface of the coil to locally increase the current density. A slot can be milled in the surface of the coil and a solid strip 38 of copper or other conductor material welded into that slot. The strip 38 can be flush with the coil surface, can protrude, or can be recessed in the surface depending on the desired effect. The use of the strips 38 can be useful when experimentally determining the correct placement of the saw slots 34. If it is determined, for example, that the saw slots extend too far along a radius, the undesired end of the saw slot can be milled out and a strip 38 inserted to restore the coil surface to essentially the unsawed state. Most importantly, however, the strips 38 provide an additional degree of flexibility in establishing the desired current distribution. It has been found particularly desirable to insert a strip 38 on the upper surface of the coil 18 which is concentric with the coil, has an inner diameter of about 50-60 millimeters and an outer diameter of about 80-85 millimeters, and which extends about 2 millimeters above the original surface of the coil 18. Such a strip 38 allows much greater flexibility in the diameter of the feed stock rod 20 that can be accommodated in the zone melting process. The strip 38 has been shown in conjunction with saw slots 34 on the top surface of the coil. In other situations it might be desirable to use such strips on either or both surfaces. The strips might be used with saw slots or might be used alone.
Thus it is apparent that there has been provided, in accordance with the invention, a float zone induction heating coil that fully satisfies the aims and advantages set forth above. While the invention has been described in conjunction with a specific embodiment, it is evident that many alternatives and variations will be apparent to those skilled in the art in light of the foregoing description. These alternatives and variations will apply particularly when zone melting other crystalline materials, especially crystalline materials having different physical dimensions.
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An induction heating coil for the float zone melting of semiconductor materials. The distribution of current on the surfaces of the coil is modified by altering the surfaces of the coil. The alteration of the surfaces is in the form of selectively positioned saw slots and solid conductor strips. The current distribution can be controlled independently on the top and bottom surfaces of the coil.
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TECHNICAL FIELD
[0001] The present invention relates to processes for manufacturing pulp and more specifically to improved processes for manufacturing dissolving pulp. The processes have been developed to be used in connection with large scale kraft processes, i.e. they have been designed to be incorporated into a plant. A liquor comprising xylan, lignin, alkali and water is also disclosed as well as a pulp and a semi-purified pulp and possible uses for these pulps.
BACKGROUND
[0002] Dissolving pulp, also known as dissolving cellulose, is a bleached wood pulp that has a high cellulose content and is produced chemically from the wood by using a sulfite process or a kraft process. The kraft process is a commonly used pulping process and in a conventional kraft process, wood is treated with an aqueous mixture of sodium hydroxide and sodium sulfide. This treatment degrades and solubilizes lignin leading to a defibration of the wood fibers.
[0003] Furthermore, conventional manufacturing of dissolving pulps by kraft processes, such as kraft processes comprising a prehydrolysis step, suffer from low yields as the hemicelluloses in the wood are degraded during the process, mainly in the prehydrolysis step and are transferred into an acid condensate as low-molecular weight hemicellulose, monosaccharides and hemicellulose degradation products. Due to difficulties in extracting these degradation products from the digester, the degraded material is at best used for energy production by evaporation and burning of the components or else simply discarded as waste.
[0004] WO 99/47733 discloses a process for producing cellulosic fibers, wherein the degree of polymerization of the obtained fibers can be adjusted via acid hydrolytic and oxidative degradation. However, the kraft pulp obtained by this process has high amounts of residual hemicelluloses, which makes the obtained pulp less useful for the production of regenerated cellulose for use in e.g. textile applications as these residual compounds have a negative impact on the process behavior and, as a result thereof, also on the textile-mechanical properties of the fibers produced therefrom.
[0005] US 2009/0312536 discloses a process for producing dissolving pulp suitable for textile applications from a cellulosic starting material using a kraft process which has been combined with a purification step of cold caustic extraction (CCE) type. The processes disclosed in US 2009/0312536 are not optimized for implementation in a kraft pulp mill, i.e. in an industrial scale process.
[0006] Both WO2011/138633 and WO2011/138634 disclose methods for pulp processing including a cold caustic extraction step. However, the disclosed methods describe costly procedures having a low total yield of dissolving pulp.
[0007] Accordingly, it is an object of the present disclosure to provide an improved industrial scale process for producing high yield dissolving pulp in an efficient and economical manner.
SUMMARY
[0008] The present invention provides improved processes for manufacturing dissolving pulp comprising a cold caustic extraction (CCE) step in the commonly used kraft process. The processes are highly suitable for use in a plant or a mill, i.e. in industrial (large) scale processes and reduces the drawbacks of previously known processes.
[0009] Hence, the present disclosure relates to a process for manufacturing dissolving pulp comprising the steps of:
a) selecting a wood based raw material, wherein said wood based raw material has a xylan content of from 12 weight % or more; b) adding a cooking liquor comprising white and/or black liquor to the wood based raw material; c) digesting the wood based raw material composition obtained from step b) in a kraft cooking process; d) oxygen delignifying the pulp obtained from step c); e) adding industrial white liquor with high ionic strength to the pulp obtained from step d), wherein said pulp has a xylan content of 8 weight % or more and wherein the temperature is lowered and kept at 65° C. or lower for 5 minutes or more and wherein the alkali concentration in the liquid phase of the obtained pulp suspension is in the range of from 70 g/l to 100 g/l; f) removing 90% or more of the alkali and dissolved xylan as a liquor flow from the pulp obtained from step e) by dewatering the pulp; and g) subjecting the pulp to washing and pressing in a washing press device 1-5 times.
[0017] By using an unconventionally high alkali concentration in step e), it is possible to introduce industrial white liquor having high ion strength into the process and still obtain high quality dissolving pulp. Accordingly, the processes disclosed herein offer economically viable industrial-scale production methods.
[0018] Removal of xylan from pulp after using cold caustic extraction (CCE), as opposed to prehydrolysis, yields alkaline liquor comprising a high concentration of high-molecular weight xylan, such liquor may be used as it is, or the xylan may be isolated therefrom. The processes disclosed herein make it possible to obtain value-added products from the xylan removed during the process for manufacturing dissolving pulp. A further advantage is that the total obtained yield of dissolving pulp is higher in processes comprising a CCE-step than for processes using a prehydrolysis-kraft process.
[0019] In previously known dissolving pulp processes, the CCE-step is carried out at low temperatures such as 20° C. to 30° C. and with reaction times in the order of 30-60 minutes. It has now been shown that the CCE-step in a process in accordance with the invention may be carried out at considerably higher temperatures allowing shorter reaction times. The use of more severe production conditions makes the process disclosed herein better adapted for industrial scale production as it reduces production time and costs for cooling and reheating process fluids between the different process steps. Accordingly, the CCE-step in the process of the invention may be carried out at a temperature as high as 65° C., such as from 50° C.-60° C. and at reaction times down to 5 minutes such as from 5 minutes to 15 minutes. No deterioration in pulp quality due to the changes in reaction conditions was observed.
[0020] Accordingly, the process of the invention has been developed for use in a plant or a mill, i.e. in an industrial environment. The process is highly suitable for integration into a kraft process for manufacturing pulp and is specifically adapted for use under the harsh conditions existing in industrial scale mill production using high ionic-strength liquids obtained from industrial processes as opposed to the more ideal conditions and liquors that can be used in lab-scale processes where cost restrictions are of less importance. As will be shown herein, this difference has a large impact on both the process and process conditions. The wood based raw material used in the process disclosed herein may be of any commonly used physical form, such as chips, saw dust or shavings.
[0021] The process may comprise a combined depolymerization and bleaching step, wherein the pulp is bleached and the viscosity of the pulp is reduced.
[0022] The white liquor used in the process is of industrial origin, i.e. it is obtained in the mill and comprises Na 2 CO 3 , NaHS and NaOH. The presence of these different sodium compounds in the liquor means that the liquor used in the CCE-step e) has very high ionic strength. A high ionic strength liquor would normally be expected to affect the CCE-step in a negative way as the content of xylan in the resulting pulp would be higher than desired in a dissolving pulp. However, the process as defined herein overcomes this problem, as it has surprisingly been found that this problem can be fully or partly solved by increasing the alkali concentration in the CCE-step e). The effects of a high ionic strength process liquid may be further mitigated by decreasing the temperature and/or by performing a steam activation step before the kraft cooking process.
[0023] A practical upper limit for the alkali concentration in the liquid phase of the pulp suspension in the CCE-step e) may be approximately 95 g/l. In a process having a wash-press step before the CCE-step e) with a dry solids content after the wash-press step of 30%, the amount of alkali in the liquid phase of the pulp suspension when using a 117 g/l white industrial liquor will be up to 83 g/l at a pulp concentration of 10%. This means that the liquid which is removed by the dewatering step f) will have an alkali content in this order. As a comparison, in a conventional process for producing dissolving pulp the amount of alkali in the liquid phase of the pulp suspension is only up to 33 g/l.
[0024] The pulp consistency can be lowered to allow a higher alkali concentration but then the white liquor need would increase which is negative from a process economy point of view as it would involve using more white liquor, larger vessels, larger process flows, etc. It may be advantageous if alkali streams coming from upstreams of the CCE-step are used in the washing step preceding the CCE-step as this will mean that the pulp is alkaline when entering the CCE-step.
[0025] Further, the white liquor added in step e) may have a suspended solids content of 20 mg/l or less, such as 10 mg/l or less, such as 5 mg/l or less, such as 1 mg/l. The suspended solids content in the white liquor is measured according to Tappi 692 om-08. It has been found that keeping the suspended solid content below 20 mg/l will provide a pure pulp with low metal ion content. The solid content measurement may be performed after the final clarification, i.e. the final sedimentation or after filtration of the white liquor. The sedimentation may be performed by, but not limited to, using a sedimentation vessel and the filtration may be performed by, but not limited to, using a filter.
[0026] The present disclosure also relates to a liquor obtainable from the CCE-step of the process and comprising xylan, water, lignin and alkali, wherein the xylan/lignin ratio is from 2:1 to 20:1, such as from 3:1 to 15:1, such as from 4:1 to 10:1, such as from 4.5:1 to 8:1, such as 6:1.
[0027] The present disclosure also relates to a pulp obtainable from the process and having a kink of from 1.3 to 2.0 kinks/mm and a shape factor of from 70 to 82% and to a pulp obtained by the processes as defined herein.
[0028] Furthermore, the present disclosure also relates to use of a pulp as defined herein for the manufacture of cellulosic products, in particular according to the lyocell process, the modal process or the viscose process.
DEFINITIONS
[0029] As used herein the term “white liquor” implies a high ionic strength industrial white liquor i.e. white liquor comprising NaOH, NaHS and Na 2 CO 3 .
[0030] The term “dissolving pulp”, as used herein, is intended to define a pulp having high cellulose content and low content of lignin and hemicellulose. The dissolving pulps are classified depending on their content of alpha-cellulose. Depending on the applications, different content of alpha cellulose is required.
[0031] The term “P-factor” describes the intensity of the activation step. The calculation and further details are described in, for example, the “Handbook of Pulp”, vol. 1, Wiley-VCH 2006, pp. 343-345.
[0032] The term “kraft cooking” refers to a cooking process, wherein a wood based raw material is inserted into an appropriate vessel or tank (e.g. a digester), a cooking liquor is added to the wood based raw material and cooking is performed by raising the temperature to a cooking temperature, such as between 140 to 180° C., which is maintained for a sufficient time for delignification to occur, e.g. up to 3 hours. The active cooking chemicals are hydroxide and hydrosulfide ions which react and degrade lignin. The objective of the kraft cooking step is to free the fibers and separate them from each other.
[0033] The terms “mill” or “plant” are used interchangeable herein and refer to a manufacturing facility that converts wood based raw material such as but not limited to wood chips to wood based products such as dissolving pulp or pulp.
[0034] The expression “filtrate operation method”, as used herein, refers to methods for reducing the amount of fresh water needed in a washing process. One method to achieve reduced fresh water consumption in a washing process is by recirculating the filtrate from a downstream washing step and use it as a washing liquid in an upstream washing step.
[0035] As used herein, the term “hemicellulose” includes different carbohydrates such as, but not limited to, xylan and (galacto)glucomannan.
[0036] As used herein, the term “xylan” is intended to include arabinoglucuronoxylan and glucuronoxylan as well as xylan originating from these two.
[0037] As used herein, the expression “industrial scale process” is intended to mean a process which is carried out on a large scale, i.e. a process which makes it economically feasible for society to use the material obtained by the process on a large scale. An industrial scale process is distinguished from small scale processes, such as laboratory scale processes, pilot plant processes, etc. where cost considerations and other conditions are different from those governing industrial production.
[0038] As used herein, the term “alkali” refers to the basic hydroxide ion. The hydroxide ion is present in different compounds such as, but not limited to, NaOH and KOH. In the present context, the concentration of alkali is always presented as NaOH regardless of counter ion. In this disclosure, this is determined by titration of a sample of the liquor with strong acid to the first inflexion point in the procedure specified in SCAN-N 2:88. “The terms effective alkali and alkali are used interchangeably”.
[0039] The term “lignin” refers to the wood component lignin or any components found in pulp or in liquors originating from lignin.
[0040] The term “intrinsic viscosity” as used herein, refers to the viscosity of dissolved pulp in a Copper Ethylene Diamine solution according to ISO 5351:2010.
[0041] Xylan was precipitated from the liquid phase of the obtained pulp suspension at acidic conditions following the protocol for beta-cellulose isolation according to Tappi T 203 om-93: 1993. The molecular weight distribution of the recovered xylan was measured by size exclusion chromatography (SEC) with multiangle light scattering (MALLS) detection in LiCl/DMAc (dimethylacetamide) solution according to Schelosky et al., 1999 (Das Papier 53:728-738).
[0042] The term “kappa number” as used herein, is an indication of the residual lignin content or bleachability of wood pulp by a standardized analysis method. The kappa number is determined by ISO 302:2004. The kappa number is a measurement of standard potassium permanganate solution that the pulp will consume. The measurement is inflated by the presence of hexenuronic acids in the pulp. These compounds are formed during the chemical pulping process, from the hemicelluloses. The kappa number estimates the amount of chemicals required during bleaching of wood pulp to obtain a pulp with a given degree of whiteness. Since the amount of bleach chemicals needed is related to the lignin content of the pulp, the kappa number can be used to monitor the effectiveness of the lignin-extraction phase of the pulping process.
[0043] As used herein “cellulose II” refers to the more thermodynamic favored allomorph of cellulose as determined by 13 C NMR. The method for measuring the content of cellulose II is described in Wollboldt et al. 2010 (Wood Science and Technology, 44, 533-546). The % values with regard to this disclosure should always be understood as given as weight % on cellulose.
[0044] The term “kink(s)” refers to the local directional changes of greater than 30° in fibers. In order to be recognized as a kink, the distance between two deformations must be at least 200 μm, the unit used is kinks/mm. Kinks are measured using image analysis of the fibers and a L&W Fiber Tester—code 912 has been used in the analyses in the present disclosure.
[0045] The term “WRV” as used herein means water retention value and is defined and analyzed according to ISO 23714:2007. The WRV-values herein have been obtained in analyses of once-dried pulp samples.
[0046] The term “shape factor” refers to the ratio of the maximum extension length of the fibre (projected fiber length) to the true length of the fibre (along the fibre contour) here expressed in %. Shape factor is thus I/Lx100 where I is the projected length and L is the true length. The shape factor is measured using image analysis of the fibers and a L&W Fiber Tester—code 912 has been used in the present analyses.
[0047] The term “lateral fibril aggregate dimension” or “LFAD” refers to the dimension of the cellulose fibril aggregates as calculated from data received by cross polarization-magic angle spinning (CP-MAS) 13 C NMR spectroscopy. The method used followed that described in Wollboldt et al. 2010 (Wood Science and Technology, 44, 533-546).
[0048] Hence, the present disclosure relates to a process for manufacturing dissolving pulp comprising the steps of:
a) selecting a wood based raw material, wherein said wood based raw material has a xylan content of from 12 weight % or more; b) adding a cooking liquor comprising white and/or black liquor to the wood based raw material; c) digesting the wood based raw material composition obtained from step b) in a kraft cooking process; d) oxygen delignifying the pulp obtained from step c); e) adding white liquor to the pulp obtained from step d), wherein said pulp has a xylan content of 8 weight % or more and wherein the temperature is lowered and kept at 65° C. or lower for 5 minutes or more and wherein the alkali concentration in the liquid phase of the obtained pulp suspension is in the range of from 70 g/l to 100 g/l; and f) removing 90% or more of the alkali and dissolved xylan as a liquor flow from the pulp obtained from step e) by dewatering the pulp; and g) subjecting the pulp to washing and pressing in a washing press device 1-5 times.
[0056] According to the process as defined herein, step e) may be performed at a temperature of 60° C. or lower, such as at a temperature of 55° C. or lower, such as at a temperature of 50° C. or lower. Additionally, step e) may also be performed in the temperature range of from 25 to 65° C., such as in the temperature range of from 30 to 60° C., such as in the temperature range of from 35 to 55° C., such as in the temperature range of from 25 to 50° C., such as in the temperature range of from 30 to 50° C. According to the process as defined herein, the temperature of step e) may be lowered at the same time as the white liquor is added or it may be lowered in steps, i.e. the temperature may be lowered before the white liquor is added and then lowered further after the white liquor is added.
[0057] The xylan content of the pulp obtained from step c) and used in step d) may be of from 8 to 35 weight %, such as from 10 to 30 weight %, such as from 14 to 28 weight %.
[0058] Further, the treatment of step e) may be performed for 5 minutes or more, such as from 5 minutes to 3 hours, such as from 5 minutes to 1 hour, such as from 5 minutes to 0.5 h, such as from 5 minutes to 15 minutes.
[0059] According to the process as defined herein, said wood based raw material may have a xylan content of from 12 weight % to 35 weight %, such as from 12 weight % to 30 weight %.
[0060] The alkali concentration of step e) may be in the range of from 75 to 100 g/l, such as in the range of from 80 to 100 g/l, such as in the range of from 85 to 100 g/l, such as in the range of from 90 to 100 g/l, such as in the range of from 95 to 100 g/l. The alkali concentration may be measured by using the method described in SCAN N-30:85, i.e. using potentiometric titration.
[0061] Furthermore, the cooking liquor:wood based raw material ratio in the digester may be from 2:1 to 6:1, such as 3:1 to 6:1, such as from 3.5:1 to 5.5:1, such as from 4:1 to 5:1, such as from 4.5:1 to 5.5:1, such as from 4:1 to 6:1.
[0062] Additionally, the process as defined herein may comprise a washing step after step d), i.e. between the oxygen delignifying step d) and the CCE-step e) such step comprising washing the pulp obtained from step d) in a washing device. Examples, but not limited to, of washing devices are wash presses, screw presses and wash filters, as known in the art.
[0063] According to the process as defined herein, the xylan and alkali removed by step f) may be fully or partly recirculated as a liquor flow and used as an alkali source in step d). Optionally, the liquor flow from step f) may be oxidized before being used in step d). Oxidation may be performed by supplying oxygen either as oxygen gas or as air using methods known to the skilled person. Recirculation of process liquor from step f) having high alkali concentration has the advantage that substantially no external alkali has to be added to the process in step d) as the recycled and reused process liquor contains a sufficient or close to sufficient amount of alkali to meet the process requirements of step d). Furthermore, all or a part of the liquor flow from step f) may be used in another process for pulp manufacturing such as in a parallel manufacturing process in the same production plant. With the process as disclosed herein, it is possible to obtain a highly concentrated process liquor from the dewatering-step f) following directly on the CCE-step e). The liquor from the dewatering-step f) has a high xylan content as well as a high alkali concentration. This means that when said liquor flow is used as an alkali source in another process for manufacturing pulp, the alkali concentration in the other process can be maintained in the range of from 60 to 90 g/l without any supplementary addition of alkali. Preferably, the liquor flow is added at a late stage of the cooking step in the parallel process and is regulated so that the amount of residual alkali in the outgoing process flow from the digester is low.
[0064] In accordance with the present method, 90% or more, such as 95% or more, of the alkali and/or xylan may be removed from the pulp obtained from the CCE-step e) in the dewatering step f) and the washing step g).
[0065] A major part of the alkali and xylan is removed from the pulp already by the dewatering step f). As step f) involves dewatering the pulp from the CCE-step e) without diluting the filtrate with a washing liquid, the process liquid which is obtained from the dewatering step has the same high xylan and alkali content as the liquid phase in the CCE-step e).
[0066] The dewatering step f) and the washing step g) may be followed by a filtering step wherein the pulp is filtered in a wash filter.
[0067] The dewatering step follows directly on the CCE-step and the liquor removed from the pulp by dewatering has a very high content of xylan and alkali and can be used directly for recycling or to supplement the process liquid in a parallel pulp production process without further concentration or purification steps. Furthermore, the high xylan content in the liquor from the dewatering step makes the liquor highly suitable for further processing and as a xylan source. The dewatering step may include pressing, the application of vacuum, use of a centrifuge and the like.
[0068] The process as defined herein may comprise an additional step before addition of the cooking liquor in step b), which additional step comprises activation of the wood based raw material using steam until reaching a P-factor of from 0 to 200, such as from 25-200, or from 50-100.
[0069] Furthermore, the process may comprise a step after dewatering, washing and optionally filtering the pulp, which step is a combined depolymerization and bleaching step. The combined depolymerization and bleaching step may be performed by adding ozone or by adding hypochlorite or by adding chlorine dioxide and sulfuric acid. The step may be performed by first adding chlorine dioxide to the pulp and then adding sulfuric acid or by first adding sulfuric acid to the pulp and then adding chlorine dioxide, i.e. said addition may be performed sequentially in any order. An advantage with the method disclosed herein is that the pulp is comparatively easy to depolymerize, implying that the depolymerization step may be carried out at relatively mild conditions requiring less addition of acid, etc.
[0070] The combined depolymerization and bleaching step may be performed at a temperature of from 80 to 99° C. and at an effective acid charge of from 5 to 20 kg H 2 SO 4 /ADT. In the present disclosure, the “effective acid charge” means the amount of sulphuric acid charged in kg/ton, i.e. it does not include the amount sulphuric acid needed for neutralization, at 10% pulp consistency. If other pulp consistencies are used the acid charge must be adjusted accordingly.
[0071] After the combined bleaching and depolymerization step, the obtained semi-purified pulp may contain 6 weight % xylan or less, such as from 2 to 6 weight %.
[0072] The present disclosure also relates to a liquor comprising xylan, water, lignin and alkali, wherein the xylan/lignin ratio is from 2:1 to 20:1, such as from 3:1 to 15:1, such as from 4:1 to 10:1, such as from 4.5:1 to 8:1, such as 6:1. The xylan/lignin ratio is the weight ratio between the two components in liquors using the two defined analyses which are disclosed herein, respectively. The liquor is obtainable from the dewatering step f) of the process as set out herein. A liquor having particularly high concentrations of xylan and alkali is obtained in the dewatering step f) following directly on the CCE-step e), as disclosed herein. It has surprisingly been found that xylan obtained from the process disclosed herein has a higher average molecular weight than xylan that may be obtained from previously known processes. Accordingly, the liquor obtained from the dewatering step f) may comprise xylan having an average molecular weight of from 15 to 40 kg/mol, such as from 20 to 35 kg/mol. A high molecular weight of the obtained xylan is particularly beneficial when the liquor obtained from the dewatering step f) is used as a process liquid in a papermaking process. A higher proportion of the added xylan will then be deposited on the pulp fibers in the papermaking process than what can be achieved with the lower molecular weight xylan that can be obtained from a conventional dissolving pulp process.
[0073] The present disclosure also relates to a process for manufacturing pulp comprising a kraft process parallel to the dissolving pulp process as disclosed herein, wherein the liquor obtained from step f) of the process as defined herein is added to the kraft cooking process in a way that the alkali may be consumed while keeping the liquor in the digester until the end of the cooking process and wherein the residual alkali concentration may be from 5 to 15 g/l. Accordingly, 80% or more of the alkali needed for the digestion of the wood based raw material in said process may be obtained from a process as defined herein.
[0074] In order to provide a good result in the CCE-step e), the chemical composition of the wood should include 12 weight % or more of xylan in addition to lignin and cellulose. Examples of such wood species are hardwoods, such as wood from birch, beech, aspen and eucalyptus. Birch, beech and aspen are particularly rich in xylan, while eucalyptus wood commonly used in pulping processes has somewhat lower xylan content. Wood species which are less suitable for use in alkali based pulp process such as the dissolving pulp processes disclosed herein are various conifers, such as spruce and pine. However, these wood species may be used, e.g. in a linked process for manufacturing pulp which may be located in the same mill. Accordingly, in a linked or parallel process, the wood source may comprise any of the wood species mentioned above as precipitation of the alkaline soluble hemicellulose may occur on wood fibers of any origin.
[0075] The washing step g) comprising one or more washing devices comprised in a process as defined herein may be performed accordingly: The pulp is first dewatered by passing the pulp through a press device wherein no dilution of the filtrate from the CCE-step e) by washing liquid is performed, implying that no liquid is added to the pulp. Thereafter the pulp is passed through two washing press devices wherein washing is performed, preferably followed by a wash filter. The washing may be performed according to a washing method as described. The washing may be performed in a countercurrent operation as is common in the art. Counter-current washing means that fresh water is added to the last washing device and that the wash liquid from a downstream wash step is used in an upstream wash step. In this manner, the fresh water is efficiently used and the risk of alkali carryover from one step to the next step is minimized.
[0076] The process as defined herein has surprisingly been technically proven to yield good results without a vapour activation step, i.e. at P-factor 0. However, if desired, the process may comprise a pretreatment step before adding the cooking liquor in step b), which pretreatment step comprises activation of the wood based raw material by using steam. The pretreatment of the wood based raw material comprises treating the wood based raw material with steam at a temperature in the range of from 150 to 180° C. before the kraft cooking step b) in order to facilitate impregnation of the wood based raw material and to prepare the wood based raw material for the cold caustic extraction step e). After the steam treatment of the wood based raw material, a conventional kraft cooking process is performed. If a condensate has been produced in the vessel used for the steam treatment, e.g. a digester, it may be advantageous to remove the condensate so that the quality of the pulp is not impaired by wood residues remaining in the condensate. As the condensate is acidic, white liquor may be used to remove the condensate. If a digester is used as a vessel for the steam treatment, the same vessel may subsequently be used for the kraft cooking process.
[0077] In the process defined herein the CCE—step e) will remove most of the xylans from the pulp. Hence, after the CCE-step, the obtained pulp may contain 6 weight % or less of xylan such as 2-6 weight % of xylan. The alkali concentration measured as effective alkali in the CCE—step e) is kept above 90 g/l when the P-factor is from 0 to 10 and is kept in the range from 75 to 90 g/l when the P-factor is from 11 to 200. The pulp consistency may be from 8 to 12 weight % and the residence time is at least 5 minutes, such as from 5 to 30 min.
[0078] The viscosity of the pulp will be decreased when applying a combined bleaching and depolymerization step. Depending on the target viscosity, the acidic charge may be from 5 to 20 kg H 2 SO 4 /ADT and the temperature may be kept at from 80 to 99° C. The residence time in the down flowing tower is accurately controlled so that the target viscosity can be obtained. This combined step has the advantage of decreasing the viscosity of the pulp and at the same time increasing brightness of the pulp. The heating of this step may be performed by steam. The advantage of using steam and adding chlorine dioxide before or after the addition of H 2 SO 4 is that any HS − (hydrogen sulfide) left in the pulp will react with the chlorine dioxide and form sulfate. Hence, the reaction between acid and HS − , which will provide H 2 S, is avoided. This step may be performed by using an up-flowing tower as the chlorine dioxide is in a gaseous form. In order to control the viscosity of the pulp, it may be transported through a tower with a down-flowing stream.
[0079] When the viscosity has been adjusted, a final brightness of the pulp of above 85% ISO may be obtained by performing a separate bleaching step. When all the specification of a dissolving pulp is met, the dissolving pulp can either be dried and sold as market pulp or be directly transferred to an integrated converting plant.
[0080] The alkali and xylan removed after the CCE-step may be used in another kraft process for manufacturing pulp, said process may be linked to the process as defined herein and may be in the same plant. One possibility to link said processes is by using a pipe, the pipe is then transporting the liquor from one process to the other. The effective alkali concentration of the transferred liquor is preferably high enough to supply the linked process with the alkali charge needed or at least with a major part of the needed alkali charge. This requirement may be fulfilled by using the washing method as disclosed above, i.e. to use a press device directly after the CCE-step instead of a conventional wash press which dilutes the filtrate. To maximize the amount of precipitation of hemicellulose onto the wood fibers to be treated in the linked process, the liquor from the process as defined herein is added to the linked process after the completion of the impregnation of the wood material so that said liquor will become the residual cooking liquor and so that said liquor will not be displaced before precipitation has occurred.
[0081] The use of the liquor from the wash-step e) in a linked process will provide good process economy as the yield from the linked process can be increased which results in better process economy and the mechanical properties of the resulting paper pulp obtained from the linked process are improved by the increased xylan content. The ratio between the production speed in the two processes should be in the order of 1:1.5 or 1:2 (dissolving pulp:paper pulp) for optimal process economy and correct alkali balance.
[0082] If the dissolving pulp obtained by a process as defined herein is intended for use in a lyocell process, the dissolving pulp should be pure in terms of high cellulose content and a low content of metal ions and should have a narrow molecular weight distribution. However, if the dissolving pulp obtained by a process as defined herein is intended for use in viscose processes, the reactivity and the filterability of the pulp are the most important parameters. The reactivity of the dissolving pulp may be improved by performing steam activation of the wood based raw material before kraft cooking process and a P-factor of 50 and above may be preferred. In case of production of dissolving pulp for solvent processes the P-factor should be minimized to such extent that the steam treatment is limited to the use of a conventional steaming step to improve the impregnation of liquors, in terms of P-factors this means a range of from 0 to 10 units.
[0083] According to the present disclosure, the CCE-step e) is performed directly after oxygen delignification as this will reduce or eliminate the need for addition of fresh alkali in the oxygen step as is otherwise always the case in pulp mills. Furthermore, this order of performing the steps will provide a pure dissolving pulp and a high value alkaline stream of soluble xylan from the dewatering step f). However, a person skilled in the art will appreciate that the CCE-step e) may be placed elsewhere in the process and that the other parts of the pulp line may be operated in a traditional way.
[0084] One of the key aspects in the production of dissolving pulp is the adjustment of viscosity within a narrow span. Depolymerization of cellulose may be performed according to different methods known to the skilled person, such as; oxidative degradation, acid depolymerization and enzymatic depolymerization. It has surprisingly been found that by using a CCE-step, the resulting pulp is much more sensitive to depolymerization than an ordinary kraft pulp or a prehydrolysed treated kraft pulp. This provides good process economy due to savings in acid charge, retention time and/or energy cost (permitting lower temperature) without impairing the yield or the quality of the resulting pulp. The conditions in the CCE-step (e.g. temperature and alkali charge) determine the kinetics of the depolymerization.
[0085] The process as defined herein may be performed in the same vessel, such as a digester, when performing the cooking and and/or the impregnation of the wood based raw material, such as in the form of batch cooking. The process as defined herein may also be performed as continuous cooking.
[0086] As mentioned above, it is also possible to use the liquor produced in the dewatering step f) in a process for manufacturing pulp comprising a kraft process, wherein said liquor is added to the kraft cooking process in a way so that the alkali is consumed while keeping the liquor in the digester until the end of the cooking process and wherein the residual alkali concentration is from 5 to 15 g/l. Furthermore, at least 80% of the alkali needed for the digestion of the wood based raw material is obtained from the process as defined herein.
[0087] Other applications for dissolving pulp may be production of regenerated cellulose, as a raw material of cellulose derivatives such as carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), etc. specialty paper-related products such as filter paper.
[0088] The dissolving pulp may be used in the processes for manufacturing viscose or lyocell fibers. Suitable applications for the viscose, modal or lyocell fibres are textiles and non-woven products. Other products that can be produced using processes in which dissolving pulp is used as the raw material are cellophane, tire cord, and various acetate and other specialty products.
[0089] The xylan/lignin ratio in a liquor is the weight ratio between the two components in the liquor as determined using the analysis methods disclosed herein. Accordingly, the determination of xylan in either wood, pulp or liquor is performed according to SCAN test method SCAN-CM 71:09 and calculated to wood components according to J. Jansson (1974, Faserforschung and Textiltechnik, 25(9), 375). When the xylan content in a liquor is determined, the first part of the acid hydrolysis using 72% sulfuric acid is omitted.
[0090] The residual lignin content in a pulp is indicated by the kappa number which is determined by ISO 302:2004 as disclosed herein while the lignin content in a liquor is determined with UV-spectrophotometry at 280 nm using the extinction coefficient for kraft lignin from birch wood; 20.8 dm 3 /g cm (Alén and Hartus, 1988, Cellulose Chemistry and Technology, 22(6), 613-618).
[0091] The present disclosure also relates to a pulp obtainable from the process as disclosed herein, said pulp having a kink of from 1.3 to 2.0 kinks/mm and a shape factor of from 70 to 82%. Additionally, the pulp obtainable from the process may have a cellulose II content of from 7 to 50 weight % on cellulose, such as from 8 to 35 weight % and a LFAD of from 16 to 40 nm, such as from 17 to 25 nm. The curly fibers defined by the kink and shape factor results in a bulky pulp sheet that absorbs liquids in latter processes much more efficient than traditional pulp. Additionally, when the pulp is used in process using dry-defibration the energy required for the defibration of this pulp is substantially lower.
[0092] The present disclosure also relates to a pulp manufactured according to the process as defined hereinabove or hereinafter. Further, said pulp may have the values mentioned above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0093] The processes disclosed herein will be described in more detail with reference to the appended drawings wherein:
[0094] FIG. 1 shows a process diagram of a process as defined herein,
[0095] FIG. 2 shows a process diagram of a process for manufacturing dissolving pulp,
[0096] FIG. 3 shows a process diagram for a process for manufacturing pulp, comprising a linked process for manufacturing pulp, and
[0097] FIG. 4 shows the result after running samples of dissolving pulp obtained from the process as defined herein.
DETAILED DESCRIPTION
[0098] FIG. 1 schematically shows the process for manufacturing dissolving pulp as defined herein. The wood based raw material may be activated by performing a steam treatment on the wood based raw material and after the steam treatment white liquor may be added to the vessel and a traditional kraft cooking process may be performed. The kraft cooking process is followed by an oxygen delignifying step and a cold caustic extraction step (CCE-step). In the CCE-step, the oxygen delignified pulp is treated with alkali. The alkali source is industrial white liquor as set out herein. Suitable but not limiting parameters for the CCE-step are a temperature of from 30 to 50° C., a NaOH concentration of from 70 to 95 g/l and a time interval of from 15 to 30 minutes. The CCE-step will reduce the xylan content in the pulp to less than 6 weight % such as to from 6 weight % to 2 weight %. Accordingly, the process as defined herein comprises the steps of kraft cooking, oxygen delignification and cold caustic extraction followed by a washing step including an initial dewatering step performed directly after the CCE-step. A steam activation step may optionally be performed before the kraft cooking step. The process may comprise further steps such as depolymerisation and bleaching to desired viscosity and brightness level. The liquor removed from the pulp by the dewatering step coupled to the CCE-step has a high alkali and hemicellulose (xylan) concentration. As disclosed herein, the alkaline hemicellulose stream from the dewatering step may be recirculated and/or removed and used in other processes and applications.
[0099] FIG. 2 is a schematical representation of a kraft process as defined herein, including an optional steam activation step. In the figures, each rectangle represents a process step, and any accompanying washing step.
[0100] In the depolymerisation step (DA), the pulp may be treated with sulfuric acid at a temperature of from 80 to 99° C. The effective amount of sulfuric acid may be from 5 to 20 kg/ADT and this step may be performed for 60 to 180 min. Before this treatment, the pulp may be treated with chlorine dioxide (D) which means that there will be chlorine dioxide present in the pulp. The obtained pulp has excellent properties, such as low viscosity, high brightness and a narrow molecular weight distribution.
[0101] The DA-step may be performed by using a chlorine dioxide charge in kg/ADT of 1.8 times the kappa number and a temperature of around 90° C. and an end pH of about 2.0. The DA-step may be performed during about 140 minutes.
[0102] The alkaline extraction step fortified with oxygen and hydrogen peroxide (EOP) may be performed according to the following, but not limiting, parameters: pH is about 10.4, O 2 is 4 kg/ADT, temperature is about 80° C.
[0103] The chlorine dioxide/complexing agent step (D/Q) may be performed according to the following, but not limiting, parameters: MgSO 4 0.6 kg/ADT, EDTA 1 kg/ADT, temperature 80° C. and a pH of 4.5.
[0104] The pressurized hydrogen peroxide step (PO) may be performed according to the following, but not limiting, parameters: pulp consistency 10 weight %, end-pH 10.5-11.0, temperature 105° C., O 2 is 3 kg/ADT, residual H 2 O 2 3.0 kg/ADT and MgSO 4 1.0 kg/ADT.
[0105] The drying of the pulp may be performed to a dry content of 90-93% and the pulp may be cut into sheets and stacked in bales.
[0106] FIG. 3 discloses the basic concept of a kraft process system according to the present disclosure, and including a parallel kraft pulping line in which the alkali and xylan containing liquor removed by the washing step after the CCE-step is used in the kraft cooking process. After the cooking step in which the alkali is consumed and the hemicellulose is precipitated onto the wood fiber the pulp may be bleached in a conventional way to a desired target brightness.
[0107] FIG. 4 shows that the dissolved pulp as manufactured according to the present disclosure has a higher degree of fibrillation than the reference sample pulp manufactured using a conventional method.
[0108] Abbreviations
[0109] mol/l mol/liter
[0110] H 2 SO 4 sulfuric acid
[0111] ADT air dried tons
[0112] EDTA ethylenediaminetetraacetic acid
[0113] O 2 oxygen
[0114] Na 2 CO 3 sodium carbonate
[0115] NaHS sodium hydrosulfide
[0116] NaOH sodium hydroxide
[0117] Na+ sodium ion
[0118] HS − hydrosulfide ion
[0119] K+ potassium ion
[0120] OH − hydroxide ion
[0121] CO 3 2− carbonate ion
[0122] H 2 O 2 hydrogen peroxide
[0123] MgSO 4 magnesium sulfate
[0124] ml/g millilitre/gram
[0125] kinks/mm kink is defined as an abrupt change in the fiber curvature
[0126] D Chlorine dioxide
[0127] A Acid
[0128] Q Complexing agent
[0129] PO Pressurized hydrogen peroxide
[0130] EOP Alkaline extraction fortified with oxygen and hydrogen peroxide
[0131] The present disclosure is further illustrated by the following non-limiting examples.
Example 1
[0132] Silver birch wood containing 25% xylan was cooked to pulp according to a Rapid Displacement Heating (RDH)-process to a kappa number of 17 in an industrial digester system. Cooking temperature was 160° C., the H-factor 350 and the residual alkali 10 g/l. After cooking, the pulp was screened before oxygen-delignification in a two-step industrial process. The temperature in the first reactor was 85° C. and 102° C. in the second reactor. The total alkali charge was 23 kg/ADT, total oxygen charge 15 kg/ADT and the magnesium sulfate charge was 3 kg/ADT. After the oxygen delignification, a pulp sample was taken out at the wash press and additionally washed in order to proceed with the pulp in the lab. The pulp had, after the oxygen delignification, a kappa number of 9.3, a brightness of 59.8% ISO and a viscosity of 1008 ml/g.
[0133] The pulp was then treated with industrial white liquor with high ionic strength at a consistency of 10%, effective alkali concentration of 95 g/l, at a temperature of 40° C. for minutes. The liquors and pulp were pre-heated to the process temperature before mixing and treated in plastic bags. After the treatment, the free liquor was pressed out and the pulp was subsequently washed with diluted filtrate at alkali concentrations of 13 g/l, 3 g/l and with water in a sequence in order to simulate an industrial washing sequence. The resulting pulp had a xylan content of 5.5 weight % and a R 18 -value of 97.8%. The filtrate, which was pressed out directly after the CCE-treatment, had an effective alkali concentration of 83 g/l and a dissolved xylan concentration of 28.8 g/l.
[0134] The pulp, after the white liquor treatment, had a great potential as a dissolving pulp, however the viscosity and brightness needed to be adjusted. This was performed in a combined chlorine dioxide and acidic step. In an industrial process, it is important that the pH in the step does not drop too much below 2.0 as this increases the risk of severe corrosion on the equipment. Instead other parameters than the acidic charge were adjusted in order to meet the demands of a dissolving pulp. The DA-step was conducted at 95° C. at an active chlorine charge of 6.1 kg/ADT and a sulfuric acid charge of 10 kg/ADT. The residence time was 165 min and the treatment resulted in a pH of 1.9. After the DA-step, an extraction step was performed at 80° C., alkali charge of 5.5 kg/ADT and a hydrogen peroxide charge of 2 kg/ADT for 120 minutes. This resulted in a pulp with a brightness of 85.7% ISO and 390 ml/g in intrinsic viscosity.
[0135] The final step was a Q PO treatment with alkali charge of 20 kg/ADT and a hydrogen peroxide charge of 10 kg/ADT. The temperature was 110° C. and the residence time 150 minutes. The pulp was thereafter analyzed and a good dissolving pulp was obtained with a R 18 -value of 97.6%, xylan content of 4.4 weight % and a viscosity of 383 ml/g.
[0136] The final pulp was also analyzed for other relevant parameters and the results are shown in Table 1. The metal ion content is an important property for a dissolving pulp and this content is very low and a reason for this is the acidic treatment at a pH of approximately 2 in the combined DA-step, which protonises the pulp acids and therefore lowers the metal ion content.
[0000]
TABLE 1
Characterization of the pulp after the different treatments
O 2
CCE
DA EOP
Q PO
Viscosity, ml/g
1008
997
389
383
Brightness, % ISO
59.8
67.3
85.7
92.3
Kappa number
9.3
3.4
—
—
R 18 , %
—
97.8
—
97.6
R 10 , %
—
—
—
94.7
xylan, %
23.6
5.5
—
4.4
Ash content, %
—
—
—
0.12
Acetone extractives,
—
—
—
0.13
%
Fe, ppm
—
—
—
1.5
Mn, ppm
—
—
—
<0.1
Mg, ppm
—
—
—
26
Si, ppm
—
—
—
20
Ca, ppm
—
—
—
22
Ni, ppm
—
—
—
0.1
Cu, ppm
—
—
—
0.2
Example 2
Mill Process
[0137] In this example a kraft mill using 4 batch digesters at 325 m 3 each was used. The raw material comprised of 93% Silver birch and 7% of other hardwoods, mainly aspen. The wood chips were steamed to a P-factor of 100 and the activation was terminated with the addition of white liquor to the bottom of the digester, immediately followed by a white and black liquor mixture until a cooking liquor:wood based raw material ratio of 3.7:1 was reached. The cooking step was performed with liquor circulation at 160° C. until a H-factor of 400 was reached. Typical properties of the pulp after the digestion was; viscosity: 1100 ml/g, brightness: 45% ISO, kappa number: 13.
[0138] The oxygen delignification was performed in a two-step reactor, using a total oxygen charge of 23 kg/ADT, without any additional charge of alkali. A charge of 1 kg MgSO 4 /ADT was used to minimize the degradation reactions. The temperature in the two steps was 86° C. for 30 min and 105° C. for additional 60 min. After this treatment, the properties of the pulp were: brightness: 56% ISO, kappa number: 9.
[0139] Since the wood was activated using steam, the alkali charge in the CCE-step could be lowered. White liquor was charged so that a concentration of effective alkali was 85 g/l at a temperature of 45° C. for 20 minutes. The resulting pulp slurry was dewatered in a press before dilution and treatment in two wash presses and one wash filter in a sequence. After washing the properties of the pulp were: viscosity: 770 ml/g, brightness: 61.9% ISO.
[0140] The filtrate after the press was analyzed and the xylan content was 24.3 g/l, lignin content was 4.6 g/l resulting in a xylan/lignin ratio of 5.3:1. The weight average molecular weight of xylan was determined to 30.0 kg/mol, corresponding to a degree of polymerization of 227.
[0141] Since the pulp still contained some hydrosulfide ions after washing, chlorine dioxide was charged first and then just after, sulfuric acid was charged. The DA-step was performed in a small up-flow tower coupled with a larger down-flow tower. The temperature was 91° C., chlorine dioxide charge was 21 kg/ADT and sulfuric acid charge was 24 kg/ADT. About 9 kg of the sulfuric acid charge was used for neutralization and the rest was used as active charge. After washing, the pulp was treated in an extractions step at 80° C., 4 kg O 2 /ADT, 2 kg H 2 O 2 /ADT and an alkali charge to reach a final pH of 10.4. The properties of the pulp after these treatments were; viscosity: 420 ml/g, brightness: 86% ISO.
[0142] To reach the target brightness, the pulp was treated in a Q PO sequence. The chelating step was performed with 0.5 kg/ADT of EDTA with 0.6 kg/ADT of magnesium sulfate at a temperature of 80° C. After washing, the PO-step was conducted with 10 kg of H 2 O 2 /ADT, kg NaOH/ADT, 1 kg MgSO 4 /ADT and 3 kg O 2 /ADT. The temperature in the bottom of the reactor was 95° C. After this final treatment, the pulp was dried in a drying machine to a dry content above 90% as set out above, cut into sheets and stacked in bales.
[0000]
TABLE 2
Characterization of the pulp after the
different treatments in the mill.
Cook
DA EOP
Q PO
Viscosity, ml/g
1100
418
422
Brightness, % ISO
45.1
86.3
91.5
Kappa number
13.2
0.9
0.9
R 18 , %
92.1
96.3
96.8
R 10 , %
88.7
92.7
93.4
xylan, %
15.8
5.0
4.1
Ash content, %
0.85
0.12
0.06
Acetone extractives,
0.86
0.16
0.26
%
Fe, ppm
2.1
1.0
1.0
Mn, ppm
27
<0.5
<0.5
Mg, ppm
68
56
77
Si, ppm
17
11
6
Ca, ppm
950
66
38
Cu, ppm
<0.5
<0.5
<0.5
Example 3
Comparison with Commercial Dissolving Pulps
[0143] Different commercial pulps (paper pulps and dissolving pulps) were collected and analysed using L&W FiberTester and CP-MAS 13 C NMR spectroscopy [Wollboldt et al. 2010 (Wood Sci. Technol. 44:533-546)]. The uniqueness of the dissolving pulp produced using the method as defined herein is illustrated in the measured data as shown in Tables 3 and 4 below.
[0000]
TABLE 3
Data from analyses of fibre dimensions with
L&W Fiber Tester and WRV-measurements.
Kinks
Shape factor
WRV
Pulp
(kinks/mm)
(%)
(g/g)
Comm. Birch paper KP 1
0.530
90.5
1.22
Comm. Eucalypt paper KP 2
0.614
91.1
1.10
Birch DP Example 2 3 (P = 0)
1.542
78.3
0.98
Birch DP Example 2 3 (P = 100)
1.510
79.5
0.90
Comm. PHK eucalypt 4
1.076
87.2
0.95
Comm. sulphite beech 5
1.266
83.9
0.80
1 Birch paper kraft pulp
2 Eucalypt paper kraft pulp
3 Birch dissolving pulp prepared according to Example 2
4 Commercial prehydrolysis kraft eucalypt dissolving pulp
5 Commercial beech sulphite dissolving pulp
[0000]
TABLE 4
Data from analyses with CP-MAS 13 C NMR spectroscopy.
Lateral
fibril
Fibril
aggregate
Cellu-
Crystal-
width
dimension
lose
linity
Pulp
(nm)
(nm)
II (%)
index (%)
Comm. Birch paper KP 1
4.4
15.3
4.2
54.5
Birch DP Example 2 2 (P = 0)
4.9
22.7
17.8
59.0
Birch DP Example 2 2 (P = 100)
5.2
18.1
8.8
60.7
Comm. PHK eucalypt 3
4.7
14.3
0.2
61.1
Comm. Sulphite beech 4
4.7
14.3
6.7
57.3
1 Birch paper kraft pulp
2 Birch dissolving pulp prepared according to Example 2
3 Commercial prehydrolysis kraft eucalypt dissolving pulp
4 Commercial beech sulphite dissolving pulp
[0144] As is evident from Table 3, a main difference between the dissolving pulp produced according to the method as defined herein and the commercial dissolving pulps, is the high kink value and the low shape factor of the pulp produced according to the invention. Furthermore, from Table 4 it is evident that pulps which have been produced according to the present method have elevated contents of cellulose II as a result of the high alkali charge in the CCE-step and that the lateral fibril aggregate dimensions are significantly larger than for the commercial pulps analysed.
[0145] In order to obtain comparative values e.g. when measuring LFAD in pulp by using NMR, it is important that the analyzed pulps are dried to the same extent. All tested commercial pulps were therefore dried in a drying machine to a dry content above 90%.
Example 4
FE-SEM
[0146] After coating with a thin layer of Au/Pd, the pulp samples were examined by high-resolution scanning electron microscopy at a 350 magnification with a Hitachi S4000 SEM (FE-SEM) applying an acceleration voltage of 6 kV. For preservation of the surface structure of moist pulps, the method of rapid freezing in liquid N 2 and normal freeze-drying described by Okamoto and Meshitsuka, 2010 (Cellulose 17:1171-1182) was applied.
[0147] The result of the SEM analysis is shown in FIG. 4 . FIG. 4 shows that the dissolving pulp fibers made according to the process of the invention are curly and have a high kink as measured by image analysis as disclosed herein. The curly pulp fibers may be formed into bulky pulp sheets that absorb liquid easily and are easy to disintegrate in a dry state.
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The invention relates to processes for manufacturing pulp and more specifically to improved processes for manufacturing dissolving pulp. The processes have primarily been developed to be used in connection with large scale kraft processes, i.e. they have been designed to be incorporated into a plant. A liquor derivable from the process and comprising xylan, lignin, alkali and water is also disclosed as well as a dissolving pulp produced by the process.
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BACKGROUND OF THE INVENTION
The present inventions relate generally to container return systems and, more particularly, to container pick and return systems that permit the efficient delivery of containers and their contents to an access aisle for easy unloading and the automatic return of empty containers to a loading aisle. The present inventions are particularly advantageous when used in assembly line applications, such as the automotive industry. However, they are equally pertinent to a wide variety of other applications.
In assembly line applications, for example, an important consideration is the constant supply of parts, typically of a wide variety of sizes, shapes and weights, to the assembly line worker. Ease of access to these parts, the removal of empty parts containers, and the re-supply of parts are also important considerations to the overall efficiency of the process. Any delay in the flow of parts, any difficulty in access to parts or any difficulty in removing empty containers can lead to inefficiencies in the entire assembly line process.
Systems capable of accommodating these considerations are shown and described in U.S. Pat. No. 5,567,103 to Konstant and U.S. Pat. No. 5,642,976 to Konstant, both entitled “Unloading Device” (the “Konstant patents”) (both of which are incorporated herein by reference). The Konstant patents teach, among other things, container unloading systems that selectively and automatically cycle carts carrying unit loads, such as containers or parts bins, to the front (or access aisle) of the system where the load is held at an angle for unloading. The system then cycles (returns) the carts and unloaded unit containers to the rear of the system (loading aisle) for re-loading and re-use. In other such systems, pallets or bins ride on pairs of parallel flow rails and carry the unit loads to the access aisle for use. The empty unit loads may then be selectively and automatically returned to the rear of the system for reloading.
Other available systems require the use of air cylinders, solenoids and motors to cycle unit loads. One such system is the Roll 'n Lift system by Creative Storage Systems, Inc. of Kennesaw, Ga. These devices utilize relatively complex electronics and pneumatics to present a pallet and return unloaded pallets and the like. Such systems suffer from, among other things, their expense, complexity and high maintenance.
In some applications, it is desirable to eliminate the necessity of wheeled carts used to carry the unit loads. In this manner, there is greater flexibility of unit load size and systems costs, and associated maintenance and shipping costs, may be reduced. For similar reasons, it is also desirable to eliminate the need for and complexity of electronically controlled air cylinders, pneumatics and motors. It is also desirable to have an efficient and smooth system that can be effective with heavy loads and provide the gentle presentation of such loads.
SUMMARY OF THE INVENTION
The present inventions preserve the advantages of container unloading and return systems and also provide new features and advantages. For example, the present inventions provide container unloading systems that can deliver unit loads, parts container bins and the like to an access aisle and automatically and smoothly present the loads at a desired angle for ease of access. The empty containers may then be automatically and selectively returned for refilling and another loaded container may automatically take its place. Such systems can accommodate a wide variety of load sizes, shapes and weights, including relatively heavy loads, all without the use of carts or complex electronically controlled pneumatics and the like.
In a preferred embodiment of the present inventions, a container pick and return system is provided having a two-tiered flow rail conveyor system that includes an inclined upper set of feed flow rails forming an input conveyor assembly and a lower set of inclined return flow rails forming an exit conveyor assembly upon which a unit load may roll. At the front end of the system is a transfer conveyor assembly that, upon receipt of a loaded container, automatically and smoothly positions the container at an angle increased from the input conveyor assembly to enhance the accessibility of the contents of the container. When the container is emptied by the line worker, the transfer conveyor assembly is triggered and the empty container is automatically lowered and transferred to the exit conveyor where it rolls down the exit conveyor to the rear of the system for reloading. Upon transfer of the empty container, the transfer conveyor assembly automatically returns to an upper position for receipt of another loaded container and subsequent angular presentation of the contents of the container. A trigger mechanism is provided to enable the selective transfer and return of unloaded containers through the activation of the transfer function. In addition, a container stop may be provided on the input conveyor such that a number of containers may wait in line behind one another in multiple depths on the input conveyor to be selectively advanced to the transfer conveyor assembly for use.
Accordingly, an object of the present invention is to provide a unit load unloading conveyor system that automatically returns empty containers, unit loads, pallets and the like to the rear of the system for reloading.
Another object of the present invention is to provide a transfer and return system that minimizes interference with the efficiency of the assembly line process by providing a steady stream of parts to the assembly line worker.
A further object of the present invention is to provide a smooth container return system that is effective for heavy loads and does not require the use of wheeled carts.
An additional object of the present invention is to provide a container unloading system that smoothly presents the contents of a container at an angle for ease of use and unloading and then smoothly, selectively and automatically transfers the unloaded container to the rear of the system.
Still another object of the present invention is to use gas springs and dampers in a container unloading system that smoothly and gently effectuates container presentation and transfer, which is also applicable for use with a wide variety of load weights, including heavy loads.
Still a further object of the present invention is to provide a container unloading system that automatically, selectively and smoothly transfers unloaded containers from an unloading end to a loading end where they may be stored or re-used.
Yet an additional object of the present invention is to eliminate the need for solenoids, motors and the like for a container unloading and return system, although such items may be used on or in conjunction with systems of the present invention.
Yet another object of the present invention is to provide a container unloading system that can accommodate multiple depths of containers and a wide variety of container contents.
Yet a further object of the present invention is to provide an unloading system that can be used in combination with other such systems and that can be used in conjunction with other transfer of storage and/or delivery systems.
INVENTOR'S DEFINITION OF THE TERMS
The terms used in the claims of this patent as filed are intended to have their broadest meaning consistent with the requirements of law. Where alternative meanings are possible, the broadest meaning is intended. All words used in the claims are intended to be used in the normal, customary usage of grammar and the English language.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, objects and advantages will become apparent from the following descriptions and drawings wherein like reference numerals represent like elements in the various views, and in which:
FIG. 1 is a semi-exploded perspective view of a preferred embodiment of the present invention shown with the transfer conveyor assembly in an upper or container entry position;
FIG. 1A is a semi-exploded perspective view of the preferred embodiment of the present invention of FIG. 1 with representative containers shown in the entry position;
FIG. 2 is a perspective view of a preferred embodiment of the present invention with the transfer conveyor assembly in a container pick or unloading position;
FIG. 2A is a perspective view of the preferred embodiment of the present invention of FIG. 2 with a representative container shown in a pick or unloading position;
FIG. 3 is a perspective view of a preferred embodiment of the present invention with the transfer conveyor assembly in a lowered or container return position;
FIG. 3A is a perspective view of the preferred embodiment of the present invention of FIG. 3 with a representative container shown in a lowered or container return position;
FIG. 4 is a perspective view of a representative support structure of a preferred embodiment of the present invention;
FIG. 5 is a perspective view of a representative support structure of a preferred embodiment of the present invention showing the placement of the return flow rails of the exit conveyor assembly;
FIG. 6 is the view of FIG. 5, additionally showing the placement of the feed flow rails of the input conveyor assembly;
FIG. 7 is a side schematic view of a transfer conveyor assembly of a preferred embodiment of the present invention shown in the upper or container entry or feed position;
FIG. 8 is a side schematic view of a transfer conveyor assembly of a preferred embodiment of the present invention shown in the container pick or unloading position;
FIG. 9 is a side schematic view of a transfer conveyor assembly of a preferred embodiment of the present invention shown in the lowered or container return or exit position;
FIG. 10 is a perspective view of a transfer conveyor assembly of a preferred embodiment of the present invention with portions removed to reveal various components of the assembly shown in an entry or feed position;
FIG. 11 is a perspective view of a transfer conveyor assembly of a preferred embodiment of the present invention with portions removed to reveal various components of the assembly shown in a pick or unloading position;
FIG. 12 is a perspective view of a transfer conveyor assembly of a preferred embodiment of the present invention with portions removed to reveal various components of the assembly shown in a return or exit position;
FIG. 13 is a greatly enlarged end view of flanged wheels on a common axis of a preferred embodiment of a component of a transfer conveyor assembly of the present invention;
FIG. 14 is a side view of a preferred trigger or activation mechanism component of the transfer conveyor assembly of a preferred embodiment of the present invention;
FIG. 15 is a perspective view of portions of a representative support structure and trigger mechanism component of a preferred embodiment of the present invention; and,
FIG. 16 is a side schematic view of an alternative embodiment of the transfer conveyor assembly of the present invention shown in the upper or container entry or feed position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Set forth below is a description of what is currently believed to be the preferred embodiment or best representative example of the invention claimed. Future and present alternatives and modifications to this preferred embodiment are contemplated. Any alternatives or modifications which make insubstantial changes in function, in purpose, in structure or in result are intended to be covered by the claims of this patent.
A container unloading or unit load pick and return system in accordance with a preferred embodiment of the present inventions is shown generally in the Figures. By reference to FIGS. 1-3 and 1 A- 3 A, the overall unloading system includes a two-level flow rail conveyor assembly 20 ; a transfer conveyor assembly 22 ; and, a support structure 24 . Each of these system components, as well as the operation of the overall system, will be described below with particular reference to assembly line applications using containers or parts bins, examples of which are shown generally as 19 in FIGS. 1A-3A. It will also understood, however, that the present inventions may be used in a large number of other applications. In addition, the present inventions are applicable to pallets, slip sheets and unit loads.
The support structure 24 is designed to support the flow rail conveyor system assembly 20 and the transfer conveyor assembly 22 . The configuration of a preferred embodiment of the support structure 24 may be seen by particular reference to FIGS. 4-6. Support structure 24 includes a number of parallel columns 30 , support braces 32 and a number of beams 34 interconnecting the parallel columns 30 . The resulting configuration is generally similar to storage bays.
Also provided are top frame members 36 , bottom frame members 38 and lower cross-frame members 40 . A center bracket 37 (see e.g., FIGS. 1-3) may be provided which may be used to, among other things, accommodate the pivotal attachment of various components of the transfer conveyor assembly 22 , as hereinafter described. In addition, in a preferred embodiment of the present invention, support structure 24 includes front guide columns 39 . Guide columns 39 are formed by opposing, inwardly facing channel members. In addition to serving a support structure 24 function, front guide columns 39 serve as guides for various components of the transfer conveyor assembly 22 , also as hereinafter described. A stop 35 may also be provided on the support structure to determine or limit the angle of presentation of containers, depending upon the application and type of access desired.
It will be understood that any number of support structures 24 may be placed in side-by-side relationship, or even stacked one on top of the other, also depending upon the application. Depending upon the design load, any necessary support can be provided by additional or larger columns, beams and the like, which may be attached in any variety of ways such as bolts, welding and the like. In addition, generally tubular structural members are used for the majority of the components of a preferred embodiment of the support structure 24 , as well as many of the components of the transfer conveyor assembly 22 , as shown in the Figures. Such members provide the preferred strength and torsional and stiffness characteristics of the preferred embodiment. However, a wide variety of cross-sectional shapes, such as cold-rolled I and S beam cross-sections, may also be used for the support structure and other components of the present inventions.
With reference to FIGS. 1-3, 1 A- 3 A and FIGS. 4-6, conveyor rail system 20 is supported by support assembly 24 . In a preferred embodiment of the present invention, conveyor rail system 20 consists of a pair of spaced, parallel input flow conveyors 21 and a pair of spaced, parallel exit return flow conveyors 23 . As will be understood by those of skill in the art, the input 21 and return 23 flow conveyors may be formed from a series of in-line rollers that define rolling surfaces which permit a container, pallet or unit load to roll along their length. In the preferred embodiment, a pair of input 21 and exit 23 conveyors are utilized. However, depending upon the type of container or unit load for which the system is designed, as well as the design loads, one or any number of additional flow conveyor assemblies may be used. Alternatively, a single flow conveyor assembly may be used for the input 21 , exit 23 and/or transfer conveyor 25 .
Input conveyors 21 are sloped gradually downward from the rear to the front of the system and return conveyors 23 are sloped downward from the front to the rear of the system. The forward end of input conveyor 21 and return conveyor 23 terminates before the front end of the system in order to accommodate the transfer conveyor assembly 22 . In addition, and of particular utility in multiple container applications, a container release mechanism may be placed on or cooperate with the input conveyor 21 to enable the selective release of containers to the transfer conveyor assembly 22 . One example of a suitable container or other unit load release assembly is shown and described in U.S. Pat. No. 5,873,473, entitled “Release Mechanism for Carts, Pallets or Unit Load Storage System,” which issued to John F. Pater and was assigned to Konstant Products, Inc., and which is incorporated herein by reference. Such a release may be readily utilized with the present inventions. In addition, retarders or brakes (not shown) may be incorporated along the input conveyor 21 in order to slow the flow of and separate any containers in the system, especially when multiple depths of containers are utilized. The type and incorporation of retarders or brakes in the present invention will be understood by those of ordinary skill in the art. In general, however, such retarders may take the form of a large rubber roller having a centrifugal brake assembly, the surface of which contacts the bottom of a roller which is in contact with the unit load or container. In this manner, among others, the flow of containers may be slowed and desired spacing maintained between containers.
The preferred transfer conveyor assembly 22 of the present inventions may be better understood by reference to FIGS. 1-3, 1 A- 3 A and 7 - 12 . The assembly 22 consists of a container deck 50 which may be constructed from a number and variety of structural members, including side deck members 51 , front deck member 52 , rear deck member 53 and center deck support 54 . As will be hereinafter described, container deck 50 and center deck support 54 may be used to accommodate some of the other components of the transfer conveyor assembly 22 . Container stops 55 are provided at the front of container deck 50 . Attached to container deck 50 are transfer flow conveyors 25 (FIGS. 1 - 3 ). Transfer flow conveyors 25 are in line with the input flow conveyors 21 to receive a container or other load (see FIGS. 1 A- 3 A). The transfer flow conveyors 25 then move with container deck 50 during the parts presentation and transfer modes as hereinafter described.
The rear end of container deck 50 is adapted to receive deck support arms 56 , which extend downwardly to bottom frame members 38 . Specifically, in a preferred embodiment, deck support arms 56 are pivotably connected at their proximate end to rear deck member 53 using tabs 57 or similar methods and configurations. A stabilizer bar 58 (FIGS. 1, 1 A and 11 ) may also be provided to ensure that deck support arms 56 rotate the same amount when the system is under load and in operation. The distal ends of deck support arms 56 are adapted to rollingly engage bottom frame members 38 . In a preferred embodiment, the distal ends of deck support arms 56 are provided with extenders 62 (see FIG. 12 ), the ends of which are adapted to accommodate wheels or rollers 59 (see FIG. 13 ). In the preferred embodiment, wheels 59 are flanged and include a second wheel or roller stop wheel 60 to cooperate with trigger mechanism assembly 70 , as hereinafter described (see FIG. 13 ). Alternatively, the distal end of the deck support arms 56 may be adapted to slide or otherwise move along bottom frame members 38 or the ground and the like.
The front end of container deck 50 is adapted to accommodate guide wheels 61 . Guide wheels 61 may be affixed to container deck 50 by any number of ways that are well known to those of ordinary skill in the art. Guide wheels 61 are sized and positioned to ride within the channels of front guide columns 39 . In this manner, and in conjunction with deck support arms 56 , container deck 50 is kept in proper alignment throughout its range of operation during container transfer and parts presentation.
Deck support arms 56 , and hence the rear of container deck 50 , are held in the entry position (see e.g., FIG. 1) by trigger mechanism 70 , which also serves to permit the selective activation of the transfer assembly 22 . Trigger mechanism 70 consists of horizontal bracket member 71 and vertical bracket member 72 , both of which serve as the frame structure for trigger lever 73 . Horizontal bracket member 71 is connected at its front end to guide columns 39 and at its rear end to vertical bracket member 72 , which in turn is connected to bottom frame member 38 . Trigger lever 73 is pivotably mounted to horizontal bracket member 71 by a torsional bar or shaft 80 . Alternatively, pins 74 or other well known means may be used (see FIG. 14 ).
In situations where multiple container pick and return systems are used side-by-side in rows, it may be helpful to position the means for activation of the trigger mechanism 70 on the front of the system, rather than the sides as shown in the preferred embodiment. One way to accomplish this is to provide the torsion bar 80 with a welded angle, plate or tab (not shown) that extends out of (or is accessible from) the front of the system. When transfer is desired, the operator may simply step on the angle or other member causing the torsion bar 80 to rotate and thereby rotate and activate the trigger lever 73 . Other means will be readily understood by those of skill in the art as dictated by the actual use and set-up of the system.
Deck support arms 56 , and their wheels 59 , are placed forward of vertical bracket member 72 so that they may roll forward along bottom members 38 . The rear end of trigger lever 73 engages stop wheel 60 when the transfer assembly 22 is in the pick position and the trigger mechanism 70 is in the stop position, as shown in FIG. 14 . When transfer of an empty container is desired, the forward end 75 of trigger lever 73 is activated, for example, by stepping on it. Upon activation, trigger lever 73 disengages stop wheel 60 (see FIG. 13 ), which enables flanged wheel 59 to roll forward along bottom member 38 and effectuates transfer, as hereinafter described. A torsion bar 80 may also be provided which interconnects the trigger lever 73 on each side of the system and in the preferred embodiment, acts as a shaft which pivots with trigger lever 73 . In this manner, when two trigger mechanism assemblies 70 are utilized, torsion bar 80 enables the simultaneous and equal activation of the system (see e.g., FIG. 15 ).
In a preferred embodiment, at least one or more, but preferably two, gas dampers 64 are provided as part of the transfer conveyor assembly 22 . The dampers 64 are connected at one end to front member 52 of container deck 50 . The other end of gas dampers 64 is angled downwardly from front members 52 and attached to center bracket ( 37 ) through tabs 65 or other well known means. The dampers 64 control the descent of the loaded container deck for smooth presentation, as well as supporting a substantial portion of the load.
At least one, and preferably two, gas springs 66 and 67 are also provided as part of transfer conveyor assembly 22 . Front gas spring 66 is connected to center support 54 of container deck 50 and is angled downward toward the rear of transfer conveyor assembly 22 and is pivotably mounted to center deck bracket 37 . Rear gas spring 67 is also pivotably mounted to center support 54 of container deck 50 toward the rear of the assembly, and is angled downward toward the front and is pivotably mounted to center bracket 37 . Alternatively, rear gas spring 67 may be mounted to tabs 83 , which are mounted to center bracket 37 or to the floor (see FIGS. 1 and 15 ). Gas springs 66 and 67 aid in controlling the descent of container deck 50 during parts presentation and transfer, and also serve to return the deck to its upper or loading position after completion of transfer. Center support 54 of container deck 50 and center deck bracket 37 of support structure 24 may be provided with a series of holes (see e.g., FIGS. 10 - 12 ). In this manner, the placement of gas springs 66 and 67 and gas dampers 64 may be adapted to provide smooth and effective operation depending upon the design load of the system and may be readjusted for different loads.
Alternative arrangements of the gas springs 66 , 67 and gas dampers 64 may be utilized. For example, only one of each may be utilized. And, as shown in FIG. 16, the gas spring 67 and gas damper 64 may be configured in a manner other than that of the preferred embodiment to achieve smooth and efficient transfer, as discussed herein. As another example, one gas spring 67 and one gas damper 64 may be positioned on each side of the transfer conveyor assembly 22 . In this configuration, the gas dampers 64 and gas springs 67 are pivotably connected between side deck members 51 and bottom member 38 , which may include an angle with a plurality of holes (not shown) for ease of assembly and adjustment.
The preferred gas springs 66 and 67 are presently available from Hahn Gas Springs of Aichschieb, Germany; namely, its gas spring model number G-14-28. Although other types and makes of gas springs may be used in the present invention, these gas springs provide the best operation and adjustability of the spring factor or constant. Other acceptable gas springs are available from Suspa, Inc. of Grand Rapids, Mich. and Stabilus of Colmar, Pa. Similarly, gas dampers 64 are presently available from Hahn Gas Springs; namely, its model number D14-40. Other suitable gas dampers that provide controlled action that can handle the designed load and control the descent of the load may be used.
The operation of a preferred embodiment of the present invention may be better understood by reference to FIGS. 1-3 and 7 - 12 . The entry position is shown in FIGS. 1, 7 and 10 . A loaded container or parts bin 19 (FIGS. 1A-3A) is placed on the rear end of input conveyor assembly 21 . As previously described, retarders may be used on the input conveyor 21 . And, if a container release mechanism (not shown) is employed along input conveyor 21 , container 19 will be engaged. Upon any such release, the container rolls forward onto transfer conveyor 25 until it comes into contact with container stop 55 . The weight of the container forces the front end of container deck 50 downward to present the parts at a desirable unloading and use angle, as shown in FIGS. 2, 8 and 11 . Dampers 64 and front gas spring 66 counteract some of the weight and slowly and smoothly lower the load to the desired angle as established by stop 35 . Guide columns 39 , in conjunction with guide wheels 61 , keep the container deck assembly in proper alignment upon descent.
Once the container is unloaded and the container collapsed, if necessary, trigger mechanism 70 is activated by depressing the forward end 75 of trigger lever 73 . As a result, stop wheel 60 is disengaged from trigger lever 73 and the wheels 59 of deck support 56 roll forward on bottom members 38 . The rear of transfer conveyor assembly 22 and container deck 50 ease downward so that the empty container may roll down transfer conveyor 25 and onto exit conveyor 23 , as shown in FIGS. 3, 9 and 12 . Once the empty container clears the transfer conveyor 25 and rolls toward the rear of the system, gas springs 66 and 67 counteract the weight of the transfer conveyor assembly 22 , and push the assembly up into the input position and ready to receive the next container. In this manner, smooth and efficient transfer of, for example, parts bins is accomplished.
The above description is not intended to limit the meaning of the words used in the following claims that define the invention. Rather, it is contemplated that future modifications in structure, function or result will exist that are not substantial changes and that all such insubstantial changes in what is claimed are intended to be covered by the claims. Thus, while preferred embodiments of the present inventions have been illustrated and described, it will be understood that changes and modifications can be made without departing from the claimed invention.
Various features of the present inventions are set forth in the following claims.
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A container pick and return system is provided having a two-tiered flow rail conveyor system that includes an inclined upper set of feed flow rails forming an input conveyor assembly and a lower set of inclined return flow rails forming an exit conveyor upon which a unit load may roll. At the front end of the system is a transfer conveyor assembly that, upon receipt of a loaded container, automatically and smoothly positions the container at an angle increased from the input conveyor assembly to enhance the accessibility of the contents of the container. When the container is emptied by the line worker, the transfer conveyor assembly is triggered and the empty container is automatically lowered and transferred to the exit conveyor where it rolls down the exit conveyor to the rear of the system for reloading. Upon transfer of the empty container, the transfer conveyor assembly automatically returns to an upper position for receipt of another loaded container and subsequent angular presentation of the contents of the container.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to lubricating structures for compressors, and more particularly, to improvements in circulation passages for lubricating oil in compressors that employ swash plates.
2. Description of the Related Art
A typical variable displacement compressor that employs a swash plate has a cylinder bore and a piston accommodated therein. A compression chamber is defined in the cylinder bore by the piston. The piston is coupled to the swash plate by means of shoes. The swash plate is arranged in the crank chamber about a drive shaft. A hinge mechanism supports the swash plate in a manner such that it is inclined in accordance with the difference between the pressure in the crank chamber and the pressure acting on the face of the piston. In this type of compressor, the swash plate is moved to a minimum inclination position at which its inclination becomes minimal with respect to a plane perpendicular to the drive shaft (the state in which the compressor displacement is minimal). When the swash plate is located at the minimum inclination position, lubricating oil, which is contained in a refrigerant, is conveyed from the compression chamber to the crank chamber through a clearance defined between the piston and the wall of the cylinder bore to lubricate the swash plate and the shoes. With regard to the swash plate, a considerable amount of load is applied to a portion corresponding with the hinge mechanism in the axial direction of the drive shaft. The load applied to this portion is greater than the load applied to other portions of the swash plate. Accordingly, it is particularly important that the portion receiving the heavy load be sufficiently lubricated to improve the durability of the swash plate.
The swash plate is provided with a shaft hole to insert the drive shaft therethrough. When machining a workpiece to form the swash plate, a reference hole extending parallel to the shaft hole is provided in addition to the shaft hole. The workpiece, which is cast and disk-like, is secured to a jig. The jig is fixed on a table of a numerically controlled (NC) milling machine. The workpiece is machined by a grinding stone that is attached to a spindle of the milling machine. The workpiece must be fixed to the jig so as to prevent it from rotating when undergoing machining. Thus, a center shaft projecting from the jig is inserted through the shaft hole of the workpiece while a positioning pin projecting from the jig is inserted through the reference hole. In this manner, the workpiece is supported at two locations by the jig to prevent rotation of the workpiece. This enables stable machining of the workpiece when forming the swash plate.
As described above, the lubricating oil contained in the refrigerant is conveyed from the compression chamber toward the crank chamber via the clearance defined between the piston and the wall of the cylinder bore. When the lubricating oil leaks into the crank chamber, the oil advances along the surface of the swash plate toward the shoes and then lubricates between the swash plate and the shoes. However, the refrigerant containing the lubricating oil flows into the reference hole. This affects the flow of the lubricating oil in an undesirable manner. Insufficient lubrication of the region receiving the heaviest load results in early wear of the plate. Such insufficient lubrication is especially troublesome in compressors that do not use clutches (clutchless compressors) such as those described in Japanese Unexamined Patent Publication Nos. 3-37378 and 7-286581.
In a typical clutchless compressor, it is important to prevent excessive compressor displacement when cooling is not required and to prevent frost from forming in the associated evaporator. The circulation of refrigerant through the external refrigerant circuit is stopped when cooling is not required or when there is a possibility of the formation of frost. In the compressors of Japanese Unexamined Patent Publication Nos. 3-37378 and 7-286581, the circulation of refrigerant in the external refrigerant circuit is stopped by impeding the flow of refrigerant gas entering the suction chamber of the compressor from the external refrigerant circuit. In these compressors, when the flow of refrigerant gas from the external refrigerant circuit to the suction chamber is impeded, the swash plate is moved to the minimum inclination position. If the flow of refrigerant gas from the external refrigerant circuit to the suction chamber is commenced, the inclination of the swash plate is increased from the minimum inclination. When the swash plate is located at the minimum inclination position, the refrigerant in the external refrigerant circuit does not return to the compressor. In this case, lubrication of the interior of the compressor is carried out by the lubricating oil contained in the refrigerant that circulates within the compressor. The refrigerant passing through the clearance is part of the refrigerant circulating within the compressor. Thus, when the lubricating oil that is contained in the circulating refrigerant becomes insufficient, it is difficult to avoid early wear since the swash plate is constantly rotated during operation of the external drive source that drives the compressor.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide a lubricating structure that ensures long life of a swash plate in a compressor, which inclinably supports the swash plate in a crank chamber and which controls the inclination of the swash plate in accordance with the difference between the pressure in the crank chamber and the pressure acting on the face of a piston.
It is another objective of the present invention to provide a lubricating structure for a compressor that enables efficient lubrication of the swash plate at portions receiving a high degree of load.
It is a further objective of the present invention to provide a lubricating structure for a compressor that employs a swash plate having superior strength.
To achieve the above objectives, an improved lubricating structure of a compressor is disclosed. A swash plate is tiltably supported on the drive shaft for integral rotation therewith. A plurality of pistons are operably coupled to the swash plate. The rotation of the swash plate is converted to reciprocal movement of each piston in an associated cylinder bore to compress and discharge gas that contains oil. A clearance is defined by the cylinder bore and the piston enabling the compressed gas to flow out from the cylinder bore to the swash plate. The swash plate has an operation area that receives greatest compression load based on reaction force of the compressed gas acting on the piston when the swash plate rotates. The swash plate has at least one bore for attaching the swash plate to a jig when the swash plate is ground during its manufacturing process. The bore is arranged to allow the gas flow out to the swash plate from the cylinder bore through the clearance to flow to the operation area.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a cross-sectional side view showing a compressor according to a first embodiment of the present invention;
FIG. 2 is a cross-sectional view taken along line 2--2 in FIG. 1;
FIG. 3 is a cross-sectional view taken along line 3--3 in FIG. 1;
FIG. 4 is a cross-sectional view taken along line 4--4 in FIG. 1;
FIG. 5 is a cross-sectional side view showing the entire compressor when the swash plate is arranged at the minimum inclination position;
FIG. 6 is a perspective view showing the manufacturing method of the swash plate;
FIGS. 7(A) and 7(B) show a second embodiment according to the present invention. FIG. 7(A) is a cross-sectional view taken along a location corresponding to FIG. 2, and FIG. 7(B) is a perspective view showing the rear side of the swash plate;
FIGS. 8(A) and 8(B) show a third embodiment according to the present invention. FIG. 8(A) is a perspective view showing the front side of the swash plate, and FIG. 8(B) is a perspective view showing the rear side of the swash plate; and
FIGS. 9(A) and 9(B) show a fourth embodiment according to the present invention. FIG. 9(A) is a perspective view showing the front side of the swash plate, and FIG. 9(B) is a perspective view showing the rear side of the swash plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A clutchless variable displacement compressor according to a first embodiment of the present invention will hereafter be described with reference to FIGS. 1 to 6.
As shown in FIG. 1, a front housing 12 is fastened to the front end of a cylinder block 11. A rear housing 13 is fastened to the rear end of the cylinder block 11. First, second, and third valve plates 14, 15, 16 and a retainer plate 17 are provided between the rear housing and the cylinder block 11.
A crank chamber 121 is defined in the front housing 12. A drive shaft 18 extends through the front housing 12 and the cylinder block 11 and is rotatably supported. The front end of the drive shaft 18 projects outward from the housing 12. A pulley 19 is secured to the projecting end of the drive shaft 18. The pulley 19 is operably connected to a vehicle engine (not shown) by a belt 20. The front housing 12 supports the pulley 19 by means of an angular bearing 21. The angular bearing 21 receives both axial and radial loads that are applied to the front housing 12 by the pulley 19.
A lug plate 22 is connected to the drive shaft 18. A disk-like swash plate 23 is provided on the drive shaft 18. The swash plate 23 is inclinable and slidable in the axial direction of the drive shaft 18. A shaft hole 231 extends through the center of the swash plate 23. The drive shaft 18 is inserted through the shaft hole 231 to enable relative sliding between the swash plate 23 and the shaft 18. The middle of the shaft hole 231 in the axial direction of the drive shaft 18 has a substantially circular cross-section. The diameter at the middle (circular portion) of the shaft hole 231 is about the same as the diameter of the drive shaft 18. The shaft hole 231 is flared toward the rear side of the swash plate 23 (toward the cylinder block 11) from the circular portion. The shaft hole 231 is also flared toward the front side of the swash plate 23 (toward the front housing 12) from the circular portion. The shape of the shaft hole 231 enables the swash plate to slide and incline with respect to the drive shaft 18 without interference.
As shown in FIG. 3, coupling pieces 24, 25 are fixed to the swash plate 23. Guide pins 26, 27 are secured to the coupling pieces 24, 25, respectively. Guide spheres 261, 271 are provided at the distal end of the guide pins 26, 27. An arm 221 projects from the lug plate 22. A pair of guide holes 222, 223 are defined in the arm 221. The guide spheres 261, 271 are slidably fitted into the guide holes 222, 223, respectively. The arm 221 cooperates with the pair of guide pins 26, 27 to permit the swash plate 23 to incline in the axial direction of the drive shaft 18 and to integrally rotate the swash plate 23 with the drive shaft 18.
The guide spheres 261, 271 are guided in the associated guide holes 222, 223 as the guide spheres 261, 271 slide therein while the swash plate 23 is supported by the drive shaft 18 as the plate 23 slides along the shaft 18. During its inclination, the swash plate 23 inclines about its upper section, as viewed in FIG. 1, which is where the piston 37 is moved to a top dead center position. The inclination of the swash plate 23 with respect to a direction perpendicular to the drive shaft 18 becomes small as the center of the swash plate moves toward the cylinder block 11.
Annular sliding surfaces 232, 233 are defined at the periphery of the front and rear sides of the swash plate 23. A reference hole 234 extends in a direction perpendicular to the sliding surfaces 232, 233 at a location that is inward from the sliding surfaces 232, 233. As shown in FIG. 2, the reference hole 234 is located at a position spaced from the region located between the guide pins 26, 27.
The reference hole 234 is used to grind the swash plate 23. For example, the reference hole 234 is used when grinding the sliding surfaces 232, 233. As shown in FIG. 6, the swash plate 23 is produced from a cast, disk-like workpiece 23D. The shaft hole 231 and the reference hole 234 are formed when casting the workpiece 23D. The workpiece 23D is ground by first securing the workpiece 23 to a jig 51. A center shaft 511 and a positioning pin 512 project from the jig 51. The center shaft 511 is inserted into the shaft hole 23 while the positioning pin 512 is inserted into the reference hole 23D. Accordingly, the workpiece 23D is supported at two locations on the jig 51. This prevents the workpiece 23D from rotating with respect to the jig 51. The jig 51 is fixed to a table of a numerically controlled (NC) milling machine (not shown). The peripheral portion on one side of the workpiece 23D is ground by a grinding stone (not shown) attached to the NC grinding machine to finish the sliding surface 232 of the swash plate 23. After the sliding surface 232 is finished, the workpiece 23D is reversed on the jig 51 and ground again to form the sliding surface 233.
A compression spring 28 is arranged between the lug plate 22 and the swash plate 23. The spring 28 urges the swash plate 23 in a direction that decreases the inclination of the swash plate 23.
As shown in FIGS. 1 and 5, an accommodating hole 29 extends through the center of the cylinder block 11 in the axial direction of the drive shaft 18. A cup-like plunger 30 is slidably accommodated in the accommodating hole 29. A compression spring 31 is arranged between the plunger 30 and an end step of the accommodating hole 29. The spring 31 urges the plunger 30 toward the swash plate 23.
The rear end of the drive shaft 18 is inserted into the plunger 30. A radial bearing 32 is supported by the inner surface of the plunger 30. The radial bearing 32 is slidable with respect to the drive shaft 18. A snap ring 33 is arranged in the plunger 30 to prevent the radial bearing 32 from falling out of the plunger 30. The rear end of the drive shaft 18 is supported by the wall of the accommodating hole 29 by means of the radial bearing 32 and the plunger 30.
A suction passage 34 extends through the center of the rear housing 13. The axis of the suction passage 34 coincides with the axis of the plunger 30. The suction passage 34 is connected with the accommodating hole 29. A positioning surface 35 is defined about the opening of the suction passage 34 on the valve plate 15. The end face of the plunger 30 abuts against the positioning surface 35. The abutment between the plunger 30 and the positioning surface 35 restricts the plunger 30 from moving further away from the swash plate 23.
A thrust bearing 36 is slidably arranged on the drive shaft 18 between the swash plate 23 and the plunger 30. The force of the spring 31 keeps the thrust bearing 36 held between the swash plate 23 and the plunger 30. As the swash plate 23 moves toward the plunger 30, the inclination of the swash plate 23 is conveyed to the plunger 30 by means of the thrust bearing 36. This moves the plunger 30 toward the positioning surface 35 against the force of the spring 31 until the plunger 30 abuts against the positioning surface 35. The thrust bearing 36 prevents the rotation of the swash plate 23 from being conveyed to the plunger 30.
A plurality of cylinder bores 111 extend through the cylinder block 11. A single-headed piston 37 is accommodated in each cylinder bore 111. Each piston 37 is coupled to the swash plate 23 by shoes 38. The rotating movement of the swash plate 23 is converted to reciprocating movement of each piston 37 by means of the shoes 38. This moves the piston 37 back and forth in each cylinder bore 111.
As shown in FIGS. 1 and 4, a suction chamber 131 and a discharge chamber 132 are defined in the rear housing 13. Suction ports 141 and discharge ports 142 are defined in the first valve plate 14. Suction valves 151 are provided in the second valve plate 15. Discharge valves 161 are provided in the third valve plate 16. When each piston 37 moves away from the valve plates 14, 15, 16, the refrigerant gas in the suction chamber 131 opens the associated suction valve 151 and enters the compression chamber 113 defined in the cylinder bore 111 through the associated suction port 141. When the piston 37 moves toward the valve plates 14, 15, 16, the refrigerant gas in the compression chamber 113 is compressed and then discharged into the discharge chamber 132 through the associated discharge port 142 as the gas opens the associated discharge valve 161. When opened, the discharge valve 161 abuts against a retainer 171 provided on the retainer plate 17. This restricts the opening of the discharge valve 161.
A thrust bearing 39 is arranged between the lug plate 22 and the front housing 12. The thrust bearing 39 receives the compression reaction that is produced in each compression chamber 113 and applied to the lug plate 22 by way of the piston 37, the shoes 38, the swash plate 23, the coupling pieces 24, 25, and the guide pins 26, 27. Accordingly, heavy load resulting from the compression reaction acts on the sliding surface 232 of the swash plate 23. The region on the swash plate 23 that receives the heaviest load is denoted as F in FIGS. 1 and 2.
The maximum reaction force is applied to the swash plate 23 at a location that is offset in the rotating direction of the swash plate 23 for a predetermined angle from the portion of the swash plate 23 that moves the pistons to the 37 top dead center position. The degree of the offset angle varies in accordance with the rotating speed and the compression ratio of the compressor. Accordingly, it is preferable that the guide pins 26, 27 be arranged so as to straddle the region at which the maximum reaction force varies. The region F corresponding to the region between the two guide pins 26, 27 is defined as a heavy load region. As described above, the heavy load region F is offset in the rotating direction of the swash plate 23 from the portion corresponding to the top dead center position. However, the swash plate 23 employed in the present invention is rotated in both forward and reverse directions. Thus, the two guide pins 26, 27 are located symmetrically with respect to a plane that includes the axis of the rotary shaft 18 and intersects the portion on the swash plate 23 corresponding to the top dead center position.
The suction chamber 131 is connected with the accommodating hole 29 through an inlet 143. When the plunger 30 abuts against the positioning surface 35, the inlet 143 becomes disconnected from the suction passage 34. A conduit 40 extends through the drive shaft 18. The crank chamber 121 is connected to the inside of the plunger 30 through the conduit 40. As shown in FIGS. 1 and 5, a pressure releasing hole 301 extends through the wall of the plunger 30. The inside of the plunger 30 is connected to the accommodating hole 35 by the pressure releasing hole 301.
As shown in FIG. 1, the discharge chamber 132 is connected to the crank chamber 121 by a pressurizing passage 41. An electromagnetic valve 42 is provided in the pressurizing passage 41. The valve 42 includes a solenoid 43, a valve body 44, and a valve hole 421. When the solenoid 43 is excited, the valve body 44 closes the valve hole 421. When the solenoid 43 is de-excited, the valve body 44 opens the valve hole 421. In this manner, the valve 42 selectively connects and disconnects the discharge chamber 132 with the crank chamber 121.
The suction passage 34, through which refrigerant gas is drawn in, and an outlet 112 of the discharge chamber 132, from which the refrigerant gas is discharged, are connected to each other by an external refrigerant circuit. The external refrigerant circuit 45 is provided with a condenser 46, an expansion valve 47, and an evaporator 48. The expansion valve 47 controls the flow rate of the refrigerant in accordance with changes in the gas temperature at the outlet side of the evaporator 48. A temperature sensor 49 is provided in the vicinity of the evaporator 48. The temperature sensor 49 detects the temperature of the evaporator 48 and sends a signal corresponding to the detected temperature to a computer C.
In response to the signal from the temperature sensor 49, the computer C excites or de-excites the solenoid 43. When an operating switch 50 is turned on, the computer C de-excites the solenoid 43 if the temperature detected by the temperature sensor 49 becomes lower than a predetermined value. The predetermined temperature corresponds to a temperature at which frost may start forming in the evaporator 48. When the operating switch 50 is turned off, the computer C de-excites the solenoid 43.
In the state shown in FIG. 1, the solenoid 43 is excited and the pressurizing passage 41 is thus closed. Accordingly, the flow of high-pressure refrigerant gas from the discharge chamber 132 to the crank chamber 121 is impeded. In this state, the refrigerant gas in the crank chamber 121 continuously flows into the suction chamber 131 by way of the conduit 40 and the pressure releasing hole 301. This lowers the pressure in the crank chamber 121 until it becomes close to the low pressure in the suction chamber 131 (i.e., suction pressure). This increases the inclination of the swash plate 23. When the swash plate 23 inclines to a maximum inclination position, a balance weight 235 provided integrally with the swash plate 23 abuts against a projection 224 projecting from the lug plate 22. This restricts further movement of the swash plate 23 from the maximum inclination position. When the swash plate 23 is held at the maximum inclination position, the compressor displacement becomes maximum.
When the ambient temperature decreases, the load of the compressor becomes small. If the swash plate 23 is held at the maximum inclination position in this state, the temperature of the evaporator 48 falls and becomes close to a temperature at which frost starts forming. The temperature sensor 49 sends a signal corresponding to the temperature of the evaporator 48 to the computer C. When the temperature becomes lower than the predetermined temperature, the computer C de-excites the solenoid 43. This opens the pressurizing passage 41 and connects the discharge chamber 132 with the crank chamber 121. Accordingly, the high-pressure refrigerant gas in the discharge chamber 132 is drawn into the crank chamber 121 through the pressurizing passage 41. This increases the pressure in the crank chamber 121. The pressure increase in the crank chamber 121 shifts the swash plate 23 to a minimum inclination position. The swash plate 23 is also shifted to the minimum inclination position when the switch 50 is turned off and the solenoid 43 is de-excited by the computer C.
When the inclination of the swash plate 23 becomes minimum, the plunger 30 abuts against the positioning surface 35 and closes the suction passage 34. Since the swash plate 23 inclines gradually and moves the plunger 30 accordingly, the plunger 30 serves to restrict the flow of the gas passing through the suction passage 34. Thus, the flow rate of the refrigerant gas flowing from the suction passage 34 to the suction chamber 131 gradually becomes small as the effective cross-sectional area of the passage therebetween decreases. This gradually decreases the amount of refrigerant gas drawn into each compression chamber 113 from the suction chamber 131. Accordingly, the discharge pressure gradually becomes smaller and the load torque of the compressor is prevented from changing suddenly. As a result, the change in load torque of the compressor is small when the compressor displacement is shifted from maximum to minimum. This eliminates shocks that may be produced by changes in the load torque.
As shown in the state of FIG. 5, when the plunger 30 abuts against the positioning surface 35, the suction passage 34 is completely closed. Hence, the flow of refrigerant gas from the external refrigerant circuit 45 to the suction chamber 131 is impeded. In other words, the circulation of the refrigerant in the external refrigerant circuit 45 is stopped. The minimum inclination position of the swash plate 23 is restricted by the abutment between the plunger 30 and the positioning surface 35.
When located at the minimum inclination position, the inclination of the swash plate 23 with respect to a plane perpendicular to the drive shaft 18 is slightly greater than zero degrees. The swash plate 23 is located at the minimum inclination position when the plunger 30 is arranged at a closing position at which the plunger 30 disconnects the suction passage 34 from the accommodating hole 29. The plunger 30 cooperates with the swash plate 23 and moves between the closing position and an opening position. Since the minimum inclination of the swash plate 23 is slightly greater than zero degrees, discharge of refrigerant gas from each compression chamber 113 to the discharge chamber 132 continues even when the swash plate 23 is located at the minimum inclination position. The refrigerant gas discharged into the discharge chamber 121 from the compression chambers 113 passes through the pressurizing passage 41 and flows into the crank chamber 121. The refrigerant gas in the crank chamber 121 flows into the suction chamber 131 by way of the conduit 40 and the pressure releasing hole 301. The refrigerant gas in the compression chamber 131 is drawn into each compression chamber 113 and discharged into the discharge chamber 132. In other words, a circulation passage of the refrigerant gas is defined in the compressor when the swash plate 23 is located at the minimum inclination position. The circulation passage extends between the discharge chamber 132 (discharge pressure zone), the pressurizing passage 41, the crank chamber 121, the conduit 40, the pressure releasing hole 301, the accommodating hole 29 (suction pressure zone), the suction chamber 131 (suction pressure inzone), and the compression chambers 113. The pressure in the discharge chamber 132, the crank chamber 121, and the suction chamber 131 differs from one another. This enables the refrigerant gas to circulate through the circulation passage. The circulating refrigerant gas lubricates the interior of the compressor with the lubricating oil suspended therein.
A clearance is defined between each piston 37 and the wall of the associated cylinder bore 111. As indicated by the arrow R in FIG. 5, the refrigerant gas in the compression chamber 113 leaks into the crank chamber 121 during the discharge stroke of the piston 37. Part of the lubricating oil, which is suspended in the refrigerant gas passing through the clearance, lubricates the area of contact between the swash plate 23 and the shoes 38.
When the ambient temperature increases in the state shown in FIG. 5, the load of the compressor becomes large. This increases the temperature of the evaporator 48. If the temperature of the evaporator 48 exceeds a predetermined temperature, the computer C excites the solenoid 43. This causes the electromagnetic valve 42 to close the pressurizing passage 41. Accordingly, the pressure in the crank chamber 121 is released through the conduit 40 and the pressure releasing hole 301. This decreases the pressure in the crank chamber 121 and extends the spring 31 from the compressed state shown in FIG. 5. The spring 31 separates the plunger 30 from the positioning surface 35 and increases the inclination of the swash plate 23 from the minimum inclination position. As the plunger 30 moves away from the positioning surface 35, the flow rate of the refrigerant gas drawn into the suction chamber 131 from the suction passage 34 gradually increases as the effective cross-sectional area of the passage therebetween increases. Accordingly, the 19 amount of refrigerant gas drawn into each compressing chamber 113 from the suction chamber 131 increases gradually. This, in turn, gradually increases the compressor displacement. Hence, the load torque of the compressor is not changed suddenly. As a result, the change in load torque of the compressor is small when the compressor displacement is shifted from minimum to maximum. This eliminates shocks that may be produced by changes in the load torque.
When the vehicle engine is stopped, the rotation of the swash plate 23 is stopped and the compressor is deactivated. The electromagnetic valve 42 is concurrently de-excited and the inclination of the swash plate 23 becomes minimum. Although the pressure in the compressor becomes uniform when the compressor remains deactivated, the swash plate 23 is maintained held at the minimum inclination position by the force of the spring 28. Accordingly, when the starting of the engine commences operation of the compressor, the swash plate 23 begins to rotate at the minimum inclination position. Since the load torque is minimum when the swash plate 23 is located at the minimum inclination position, the shock, which is produced when commencing operation of the compressor, is minimal.
As described above, the refrigerant gas in each compression chamber 132 leaks into the crank chamber 121 through the clearance defined between each piston 37 and the wall of the associated cylinder bore 111. Each piston 37 has a basal portion 381 that is defined at the periphery of the cylinder block 121 to couple the sliding surfaces 232, 233 of the swash plate 23 with the shoes 38. This causes the refrigerant gas to leak mainly through the portion of the clearance that is closer to the center of the cylinder block 121, as indicated by arrow R in FIG. 5. Part of the refrigerant oil that leaks from the clearance, advances along the swash plate 23 toward the sliding surface 232. This allows the refrigerant gas to be supplied to the heavy load region F, at which the compression reaction force is heaviest on the sliding surface 232. In other words, refrigerant gas is supplied to the portion corresponding to the region between the two guide pins 26, 27. The reference hole 234 is offset angularly with respect to the guide pins 26, 27. Thus, the flow of refrigerant gas from the center portion of the swash plate 23 toward the heavy load region F on the sliding surface 232 is not obstructed by the reference hole 234. Accordingly, the reference hole 234 does not hinder the lubrication of the heavy load region F.
In addition, the reference hole 234 does not extend through either one of the guide pins 26, 27 and the coupling pieces 24, 25. Thus, the strength of the guide pins 26, 27 and the coupling pieces 24, 25 remains unafected.
When the circulation of refrigerant through the external refrigerant circuit 45 is stopped, the inclination of the swash plate 23 becomes minimum. If the circulation of the refrigerant is commenced, the inclination of the swash plate 23 is increased. The swash plate 23 is constantly rotated when the external drive source is operating. Thus, the heavy load region F defined on the sliding surface 232 between the swash plate 23 and the shoes 38 must be lubricated even when the swash plate 23 is located at the minimum inclination position, that is, when the compressor displacement is minimum. When the compressor displacement is minimum, the refrigerant in the external refrigerant circuit is not returned to the compressor. In this state, the heavy load region F on the sliding surface 232 is lubricated solely by the lubricating oil suspended in the refrigerant circulating within the compressor. Accordingly, in the swash plate 23 provided with the reference hole 234 at the location described above, the lubrication of the heavy load region F is not hindered by the reference hole. This structure is especially effective in clutchless compressors.
A second embodiment according to the present invention will now be described with reference to FIGS. 7(A) and 7(B). Elements that are identical to those employed in the first embodiment will be denoted with the same reference numerals. In this embodiment, the reference hole 234 extends through the swash plate 23 on the opposite side of the shaft hole 231 with respect to the guide pins 26, 27. The reference hole 234 extends through the balance weight 235. Since the reference hole 234 is located at a position farthest from the heavy load region F, which is on the other side of the drive shaft 18, the effect that the reference hole 234 has on the lubrication of the heavy load region F is minimal.
Furthermore, the reference hole 234 extends through the balance weight 235. It is necessary to limit the diameter of the reference hole 234 to ensure the required strength in the swash plate 23. However, in the swash plate 23, the strength is highest at the location of the balance weight 235. Thus, by providing the reference hole 234 in the balance weight 235, the diameter of the reference hole 234 may be changed without having to worry about the strength of the swash plate 23.
A third embodiment according to the present invention will now be described with reference to FIGS. 8(A) and 8(B). Elements that are identical to those employed in the first embodiment will be denoted with the same reference numerals.
In this embodiment, a reference hole 236 is provided in the front side of the swash plate 23 while another reference hole 237 is provided in the rear side of the swash plate 23. Each reference hole 236, 237 is a blind hole that does not extend through the swash plate 23. The reference holes 236, 237 are located symmetrically with respect to a radial line r, which extends from the axis of the swash plate 23 to the middle point between the guide pins 26, 27. In this embodiment, the lubrication of the heavy load region F is substantially unaffected by the reference holes 236, 237 since they do not extend through the swash plate 23.
A fourth embodiment according to the present invention will now be described with reference to FIGS. 9(A) and 9(B). Elements that are identical to those employed in the first embodiment will be denoted with the same reference numerals.
In this embodiment, a reference hole 238 is provided in the front side of the swash plate 23 while a reference hole 239 is provided in the rear side of the swash plate 23. Each reference hole 238, 239 is a blind hole that does not extend through the swash plate 23. Each reference hole 238, 239 is provided along the radial line r. A guide groove 52 connecting the reference hole 238 and the sliding surface 232 is provided on the rear side of the swash plate 23. The reference hole 238 and the guide groove 52 guide the flow of refrigerant gas that leaks into the crank chamber 121 from the compression chambers 113 toward the heavy load region F on the sliding surface 232. In the same manner as the third embodiment, the lubrication of the heavy load region F on the sliding surface 232 is substantially unaffected by the reference holes 238, 239 since they do not extend through the swash plate 23. Furthermore, since the guide groove 52 guides the refrigerant gas, lubrication of the heavy load region F on the sliding surface 232 is facilitated.
The present invention is applied to clutchless variable displacement compressors in the above embodiments. However, the present invention may also be applied to variable displacement compressors that have clutches.
Although several embodiments of the present invention have been described herein, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Therefore, the present examples and 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 of the appended claims.
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An improved lubricating structure of a compressor is disclosed. A swash plate is tiltably supported on the drive shaft for an integral rotation therewith. A plurality of pistons are operably coupled to the swash plate. The rotation of the swash plate is converted to a reciprocal movement of each piston in an associated cylinder bore to compress and discharge gas that contains oil. A clearance is defined by the cylinder bore and the piston enabling the compressed gas to flow out from the cylinder bore to the swash plate. The swash plate has an operation area that receives greatest compression load based on reaction force of the compressed gas acting on the piston when the swash plate rotates. The swash plate has at least one bore for attaching the swash plate to a jig when the swash plate is ground during its manufacturing process. The bore is arranged to allow the gas flow out to the swash plate from the cylinder bore through the clearance to flow to the operation area.
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TECHNICAL FIELD
[0001] The present invention relates to separators for oil and gas wells, and more particularly to a rotary, downhole, gas and liquid separator and a downhole method of separating gas and liquid from production fluid.
BACKGROUND ART
[0002] Liquids are substantially incompressible fluids while gases are compressible fluids. The production fluid in an oil or gas well is generally a combination of liquids and gases. In particular, the production fluid for methane production from coal formation includes the gas and water. Pumping such production fluid is difficult due to the compressibility of the gas. Compression of the gas reduces the efficiency of the pump and the pump can cavitate, stopping fluid flow. Downhole gas and liquid separators separate the gas and liquid in the production fluid at the bottom of the production string, before pumping the liquid up the production string, and thereby improve the efficiency and reliability of the pumping process. In some cases, the waste fluids from the production fluid may be reinjected above or below the production formation, eliminating the cost of bringing such waste fluids to the surface and the cost of disposal or recycling.
[0003] U.S. Pat. No. 5,673,752 to Scudder et al. discloses a separator that uses a hydrophobic membrane for separation. U.S. Pat. No. 6,036,749 to Ribeiro et al., U.S. Pat. No. 6,066,193 to Lee and U.S. Pat. No. 6,382,317 to Cobb disclose powered rotary separators. U.S. Pat. No. 6,155,345 to Lee et al. discloses a separator divided by flow-through bearings into multiple separation chambers.
DISCLOSURE OF THE INVENTION
[0004] A downhole separator includes a housing defining an interior cavity, a means for restricting fluid flow, an internal pump and a vortex generator. The means for restricting fluid flow is located in the housing and divides the interior cavity into a first chamber and a second chamber. The internal pump pumps production fluid into the first chamber and through the means for restricting flow. The means for restricting flow generates a pressure drop in production fluid entering the second chamber, causing the gas and liquid to separate. The vortex generator segregates the liquid to the outside and gas to the inside of the second chamber. The method of separating liquid and gas from production fluid includes pumping production fluid into a first chamber, generating a pressure drop in the production fluid as the production fluid flows from the first chamber into a second chamber, and generating a vortex in the production fluid in the second chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Details of this invention are described in connection with the accompanying drawings that bear similar reference numerals in which:
[0006] [0006]FIG. 1 is a side elevation view of a separator embodying features of the present invention.
[0007] [0007]FIG. 2 is a side cut away view of the separator of FIG. 1.
[0008] [0008]FIG. 3 is a partially cut away view of the head of the separator of FIG. 1.
[0009] [0009]FIG. 4 is a partially cut away view of the lower diffuser of the separator of FIG. 1.
[0010] [0010]FIG. 5 is a partially cut away view of the upper diffuser of the separator of FIG. 1.
[0011] [0011]FIG. 6 is a partially cut away view of the bearing housing of the separator of FIG. 1.
[0012] [0012]FIG. 7 is a partially cut away view of the impeller of the separator of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring now to FIGS. 1 and 2, a separator 10 embodying features of the present invention includes a housing 11 , a base 12 , and a head 14 . The housing 11 is a hollow, elongated, cylinder defining an interior cavity 15 . The separator housing 11 has spaced, internally threaded lower and upper ends 17 and 18 .
[0014] Describing the specific embodiments herein chosen for illustrating the invention, certain terminology is used which will be recognized as being employed for convenience and having no limiting significance. For example, the terms “top”, “bottom”, “up” and “down” will refer to the illustrated embodiment in its normal position of use. “Inward” and “outward” refer to radially inward and radially outward, respectively, relative to the axis of the illustrated embodiment of the device. Further, all of the terminology above-defined includes derivatives of the word specifically mentioned and words of similar import.
[0015] The base 12 has an upper portion 20 , an intermediate portion 21 and a lower portion 22 . The upper portion 20 is an externally threaded, hollow, cylinder sized and shaped to thread into the lower end 17 of separator housing 11 , and includes an upwardly opening, centered, generally cylindrical upper cavity 24 . The intermediate portion 21 has an exterior surface 25 that, in the illustrated embodiment, extends downwardly and inwardly from the upper portion 20 and has a centered lower bearing aperture 26 extending downward from the upper cavity 24 . A lower bearing 28 is mounted in the lower bearing aperture 26 . A plurality of circumferentially arranged inlet ports 27 extend from the exterior surface 25 upwardly and inwardly into the upper cavity 24 . The lower portion 22 is hollow and generally cylindrical, and extends downward from the intermediate portion 21 to an outwardly projecting flange 29 , with a lower cavity 30 extending from the lower bearing aperture 26 .
[0016] Referring to FIG. 3, the head 14 includes an upper portion 34 , an intermediate portion 35 extending downward from the upper portion 34 , and a lower portion 36 extending downward from the intermediate portion 35 . The upper portion 34 is generally cylindrical and includes a plurality of spaced, radially arranged, upwardly extending, threaded studs 38 . An external, circumferential channel 39 extends around the head 14 between the upper portion 34 and the intermediate portion 35 . The intermediate portion 35 is externally threaded, and sized and shaped to thread into the upper end 18 of the separator housing 11 . An upwardly opening, inwardly and downwardly tapering, generally conical upper cavity 40 extends through the upper portion 34 and the intermediate portion 35 .
[0017] The lower portion 36 has a downwardly and inwardly tapering exterior surface 41 , and a downwardly opening, downwardly and outwardly tapering lower cavity 42 that connects to the exterior surface 41 at a lower end 43 . An upper bearing aperture 44 extends between the upper cavity 40 and the lower cavity 43 , and has an upper bearing 45 mounted therein. A plurality of circumferentially arranged liquid outlet ports 47 extend upwardly and inwardly from the exterior surface 41 to the upper cavity 40 . A plurality of circumferentially arranged gas outlet ports 48 extend upwardly and outwardly from the lower cavity 42 to the channel 39 .
[0018] Referring again to FIG. 2, the separator 10 includes a lower diffuser 50 , an upper diffuser 51 , a first sleeve 52 , a means for restricting flow 53 , a second sleeve 55 and a third sleeve 56 , with each having a cylindrical exterior sized and shaped to fit into the interior cavity 15 of the separator housing 11 , and with each being assembled into the interior cavity 15 in the above listed order from the base 12 to the head 14 . In the illustrated embodiment the means for restricting fluid flow 53 is a bearing housing 54 . Other means for restricting fluid flow 53 are suitable for the present invention.
[0019] As shown in FIG. 4, the lower diffuser 50 is substantially cup shaped with a generally flat round bottom 58 , an outer wall 59 extending upward from the periphery of the bottom 58 , and a lower diffuser aperture 60 extending through the center of the bottom 58 . Referring to FIG. 5, the upper diffuser 51 includes an upper diffuser aperture 62 extending upwardly through the center of upper diffuser 51 , a cylindrical outer wall 63 , and a plurality of spaced, radially arranged, upwardly, inwardly and helically extending passages 64 between upper diffuser aperture 62 and the outer wall 63 , with passages 64 being separated by radial fins 65 . The outer wall 59 of the lower diffuser 50 extends upwardly and the outer wall 63 of the upper diffuser 51 extends downwardly to space the lower and upper diffusers 51 and 52 apart to define an impeller cavity 67 therebetween.
[0020] The bearing housing 54 , as shown in FIG. 6, is generally cylindrical with an intermediate bearing aperture 68 and a plurality of spaced, radially arranged passages 69 extending through the bearing housing 54 . An intermediate bearing 70 is mounted in the intermediate bearing aperture 68 . Passages 69 are configured to restrict fluid flow so that bearing housing 54 divides the interior cavity 15 into a first chamber 71 and a second chamber 72 . In the illustrated embodiment the passages 69 extend upwardly, inwardly and helically, so that the passages 69 initiate vortex generation in the production fluid as the production fluid flows into the second chamber 72 . Referring back to FIG. 2, the first, second and third sleeves 53 , 55 and 56 are each relatively thin walled hollow cylinders. The first sleeve 52 spaces the bearing housing 54 from the upper diffuser 51 . The second and third sleeves 55 and 56 together space the bearing housing 54 from the head 14 .
[0021] An elongated cylindrical shaft 74 extends through the interior cavity 15 with a splined lower end 75 extending into the lower cavity 30 of the base 12 and a spaced, splined upper end 76 extending into the upper cavity 40 of the head 14 . Lower, intermediate and upper bearing journals 77 , 78 and 79 are sized and spaced along the shaft 74 to fit the lower, intermediate and upper bearings 28 , 70 and 45 , respectively. A keyway 80 extends longitudinally along shaft 74 with a key 81 mounted therein. An internal pump 82 mounts on the shaft 74 . Internal pump 82 is shown in the illustrated embodiment in FIG. 7 as impeller 83 , in the impeller cavity 67 , having a hub 84 on shaft 74 secured by key 81 and a plurality of spaced, radially arranged, upwardly, outwardly and helically extending passages 85 around the hub 84 . Other styles of internal pump 82 , such as an auger pump, are suitable. A vortex generator 86 is shown in FIG. 2 as a paddle assembly 87 positioned in the second chamber 72 and having a hub 88 on shaft 74 secured by key 81 and a plurality of spaced vertical paddles 89 that extend radially from the hub 88 . Other styles of vortex generator, such as spiral or propeller, are also suitable.
[0022] In a typical installation of the separator 10 mounts between a motor on the flange 29 of the base 12 and a well pump secured to the head 14 by the studs 38 . The impeller 83 pulls production fluid into the first chamber 71 of the separator 10 through the inlet ports 27 and lower diffuser 50 and pumps the production fluid into the upper diffuser 51 . The upper diffuser 51 directs production fluid up to the bearing housing 54 .
[0023] The passages 69 restrict the flow of production fluid through the bearing housing 54 between the first and second chambers 71 and 72 , generating a pressure drop and rapid expansion of the production fluid enter the second chamber 72 . The rapid expansion of the production fluid causes gas in the production fluid to expand and separate from liquid in the production fluid. From the bearing housing 54 the liquid and gas travel upward to the vortex generator 87 . The paddles 89 push the liquid and gas in a circular direction and thereby centrifugally segregate the liquid at the outside and the gas at the inside of the second chamber 72 . The liquid passes upwardly to the liquid outlet ports 47 and into the well pump. Gas passes upwardly to the gas outlet ports 48 and out of the separator 10 at the channel 39 .
[0024] A method of separating gas and liquid from production fluid in a well, embodying features of the present invention, includes providing connected first and second chambers, pumping production fluid into the first chamber, generating a pressure drop in the production fluid as the fluid passes between the first and second chamber, and generating a vortex in the second chamber. More particularly, the first step of the method includes providing connected first and second chambers, a bearing housing between the first and second chambers, a rotary paddle in the second chamber, and gas outlet ports and liquid outlet ports connected to the second chamber, with the bearing housing having a plurality of restrictive passages extending helically between the first and second chambers. The next step includes pumping the production fluid into the first chamber. The next step includes passing said the production fluid through the passages to generate a pressure drop in said production fluid as the production fluid flows into the second chamber to separate the gas and the liquid. Passing the production fluid through the passages also imparts a helical flow to the production fluid and thereby initiates generation of a vortex. The next step includes rotating the paddle to continue vortex generation to further separate the gas and the liquid. The gas is then diverted out of the second chamber through the gas outlet ports, and the liquid is diverted out of the second chamber through the liquid outlet ports.
[0025] Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.
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A downhole separator has a housing defining an interior cavity divided into a first chamber and a second chamber by a flow restricting bearing housing. A shaft driven impeller pumps production fluid into the first chamber and to the bearing housing. The bearing housing generates a pressure drop in production fluid entering the second chamber, separating gas from liquid. A vortex generator in the second chamber segregates the liquid to the outside and the gas to the inside of the second chamber. A downhole separation method includes pumping production fluid into a first chamber, and generating a pressure drop in the fluid as the fluid enters a second chamber to separate gas and liquid.
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[0001] Under 35 U.S.C. § 119(e), this application claims the benefit of prior U.S Provisional Application No. 60/474,348, filed May 30, 2003, and prior U.S. Provisional Application No. 60/499,817, filed Sep. 2, 2003, which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] In one aspect, the present invention relates to a process for regioselective O-alkylation of macrolides and azalides applicable on a large scale. Specifically, the invention relates to regioselective 11-O-alkylation of macrolides and azalides having vicinal diol system, using diazoalkanes in the presence of transition-metal halides or boric acid as catalysts. In another aspect, the invention relates to 11-O-alkyl macrolides and azalides obtained according to the above mentioned process, pharmaceutically acceptable salts and solvates thereof and uses thereof as antibacterial agents or intermediates for the synthesis of other antibacterial agents.
BACKGROUND OF THE INVENTION
[0003] Several O-alkyl derivatives of macrolide and azalide antibiotics have been described in the literature. Among them O-methyl derivatives of erythromycin (clarithromycin) (U.S. Pat. No. 4,331,803) and azithromycin (U.S. Pat. No. 5,250,518) have significant biological activity. The process for preparing O-alkyl derivatives of macrolides and azalides is typically a multistep procedure. Because macrolide and azalide compounds posses several hydroxyl groups it has previously been difficult to alkylate one hydroxyl group selectively in the presence of other unprotected hydroxyl or amino groups (see e.g. J. Antibiot. 46 (1993) 647, 1239; J. Antibiot. 43 (1990) 286). In order to carry out selective O-alkylation of macrolides and azalides, the use of various protecting groups has been described in the literature (see e.g. J. Antibiot. 45 (1992) 527, J. Antibiot. 37 (1984) 187, J. Antibiot. 46 (1993) 1163, U.S. Pat. Nos. 5,872,229; 5,719,272and 5,929,219). Specifically, the multistep selective synthesis of 12-O-methyl azithromycin has been described in WO 99/20639. However, the selective substitution at the 11-O-position with alkyl group is not easily accomplished by prior art methods and is accompanied by side reactions, by-products and low yields.
[0004] Generally, the classical method for O-methylation of macrolides and azalides proceedes by initial protection of the reactive sites on the desosamine, typically as 2′-OCbz-3′NMeCbz. Such protected derivative is then O-methylated in a dipolar aprotic solvent (e.g. DMSO/THF or DMF) using a base (e.g. KOH or NaH) and methyl iodide. Removal of the Cbz's and Eschwiler-Clarke methylation of the 3′-nitrogen completes the sequence. It should be noted that there are four hydroxyls that can be methylated (4′, 6, 11 and 12) and mixtures of various mono-, di- and tri-O-methylated derivatives are usually obtained.
[0005] Moreover, prior art investigations showed that (Bioorg.Med.Chem.Lett., 8 (1998)549) the relative reactivity of hydroxyl groups under the classical O-methylation reaction conditions proceeds in following order: for the 8a-azalides 4″-OH>12-OH>>11-OH, for 9a-azalides 11-OH≧12-OH>4″-OH. It is important to mention that under even the most vigorous reaction conditions O-methylation of 8a- and 9a-azalide 6-OH group does not occur. This is in contrast to the O-methylation of erythromycin in which system the 6-OH is easily methylated under conditions very similar to these (J.Antibiotics 43 (1990)286). However, in all cases mixtures of various mono-, and di- and tri-O-methylated derivatives are generally obtained. The relative rates of methylation of the hydroxyls presumably depend on subtle conformation details and are not predictable by a cursory inspection of the structure.
[0006] On the other hand substantially or partially regioselective, but not complete, regioselective methylation of various monosaccharides and nucleosides with diazomethane in the presence of transition-metal halides or boric acid has been described in the literature, [Carb.Res. 316 (1990) 187; Helv. Chim. Acta 79 (1996) 2114-2136; Chem.Pharm.Bull., 18 (1970) 677; Carb.Res., 91 (1981) 31], but it has not been possible to predict the site of methylation. Moreover, there are no known reports of regioselective O-alkylation of the 11-hydroxyl group of macrolides and azalides with diazoalkanes in the presence of transition-metal halides or boric acid
[0007] In connection with these reported observations, the exclusive (complete) regioselective 11-O-methylation by the process of the present invention is unique and not obvious.
SUMMARY OF THE INVENTION
[0008] In one aspect, the present invention relates to a process for regioselective O-alkylation of macrolides and azalides, for the preparation of 11-O-alkyl compounds of formula (I) and pharmaceutically acceptable salts and solvates thereof.
wherein
A is derived from either a 14-membered macrolide or a 15-membered azalide, and R 1 is a C1-C4 alkyl group, which process comprises, reacting a macrolide or azalide having vicinal hydroxyls of formula (II)
with a diazoalkane of formula (III):
R 2 —CH N 2 (III)
wherein
R 2 is hydrogen or a C1-C3 alkyl group in the presence of a catalyst of a transition-metal halide or boric acid, preferably H 3 BO 3 , TiCl 4 or SnCl 2 , in a suitable inert organic solvent.
[0013] Preferably, the 14- and 15-membered macrolides and azalides reacted in the process of the present invention have the formula (IV)
wherein
A is a bivalent radical selected from —C(O)—, —C(O)NH—, —NHC(O)—, —N(R 11 )—CH 2 —, —CH 2 —N(R 11 )—, —CH(NR 11 R 12 )— and —C(═N—OR 13 )—; R 1 is cladinosyl of formula (V), OH or together with R 2 forms a keto group provided that when R 1 together with R 2 forms a keto group R 4 is not H;
R 2 is H or together with R 1 forms a keto group; R 3 is desosaminyl of formula (VI) or hydroxyl;
R 4 is hydrogen, C 1-4 alkyl, or C 2-6 alkenyl optionally substituted by 9 to 10 membered fused bicyclic heteroaryl; R 5 is hydrogen or fluorine; R 6 is hydroxyl, —NH 2 , or together with R 7 forms a keto group or ═NR 10 ; R 7 is hydrogen, —NH 2 , or together with R 6 forms a keto group or ═NR 10 ; R 8 is H or a carbobenzoxy group; R 9 is H, CH 3 or a carbobenzoxy group; R 10 is hydrogen or C 1-6 alkyl; R 11 and R 12 are each independently hydrogen, C 1-6 alkyl, aryl, heteroaryl, heterocyclyl, sulfoalkyl, sulfoaryl, sulfoheterocyclyl or —C(O)R 10 , wherein the alkyl, aryl and heterocyclyl groups are optionally substituted by up to three groups independently selected from R 14 ; R 13 is hydrogen, —C 1-6 alkyl, C 2-6 alkenyl, —(CH 2 ) a aryl, —(CH 2 ) a heterocyclyl, or —(CH 2 ) a O(CH 2 ) b OR 10 ; R 14 is halogen, cyano, nitro, hydroxyl, C 1-6 alkyl, C1-6alkoxy or aryloxy, C1-6alkythio or arythio, —NH 2 , —NH(C 1-6 alkyl), or —N(C 1-6 alkyl) 2 ; and a and b are each independently integers from 1 to 4
[0029] The process may be utilized to prepare 11-O-alkyl macrolides, including, but not limited to 11-O-alkyl derivatives of clarithromycin (J. Antibiot. 43 (1990) 544-549) and roxithromycin (J. Antibiot 39 (1986) 660). The process of the present invention, may also be used to prepare 11-O-alkyl azalides including, but not limited to 11-O-alkyl derivatives of azithromycin (J. Chem. Research (S) (1988) 152, J. Chem. Research (M) (1988) 1239), 2′-O,3′-N-dicarbobenzoxy-azithromycin (J. Antibiotics 45 (1992) 527), 9-deoxo-9a-aza-9a-homoerythromycin (J. Chem. Soc. Perkin Trans. 1 (1986) 1881), 3-decladinosyl-5-dedesosaminyl-9-deoxo-9a-aza-9a-homoerythromycin(J. Chem. Soc. Perkin Trans. 1 (1986) 1881-1890), 8a-aza-8a-homoerythromycin (Bioorg. Med. Chem. Lett. 3 (1993) 287).
[0030] In another aspect, the invention relates to 11-O-alkyl azalides of formula (VIIa):
wherein
Y is nitrogen and Z is the bivalent radical —CH 2 —, or Y is —C(O)— and Z is nitrogen; R 1 is OH or cladinosyl of formula (V);
wherein R 6 is hydroxyl;
R 7 is hydrogen; R 2 is hydroxyl, or desosaminyl of formula (VIII):
R 3 is hydrogen or a CH 3 group; and R 4 is a C 1 -C 4 alkyl group; or an 11-O-alkyl macrolide of formula (VIIb)
and pharmaceutically acceptable salts and solvates thereof and uses thereof as antibacterial agents or intermediates for the synthesis of other antibacterial agents.
DETAILED DESCRIPTION OF THE INVENTION
[0038] As used herein, the following terms are defined as follows:
[0039] The term “regioselective” refers to a reaction in which one direction of bond formation or elimination occurs preferentially over all other possible alternatives; reactions are termed completely (100%) regioselective if the selectivity is complete, or substantially regioselective (at least about 75 molar %), or partially (at least about 50 molar %), if the product of reaction at the specified site predominates over the products of reaction at other sites.
[0040] The term “alkyl” as used herein as a group or a part of a group refers to a straight or branched hydrocarbon chain containing the specified number of carbon atoms. For example, C 1-6 alkyl means a straight or branched alkyl containing at least 1, and at most 6, carbon atoms. Examples of “alkyl” as used herein include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, isobutyl, isopropyl, t-butyl and hexyl.
[0041] The term “alkenyl” as used herein as a group or a part of a group refers to a straight or branched hydrocarbon chain containing the specified number of carbon atoms and containing at least one double bond. For example, the term “C 2-6 alkenyl” means a straight or branched alkenyl containing at least 2, and at most 6, carbon atoms and containing at least one double bond. Examples of “alkenyl” as used herein include, but are not limited to, ethenyl, 2-propenyl, 3-butenyl, 2-butenyl, 2-pentenyl, 3-pentenyl, 3-methyl-2-butenyl, 3-methylbut-2-enyl, 3-hexenyl and 1,1-dimethylbut-2-enyl.
[0042] The term “alkoxy” as used herein refers to a straight or branched chain alkoxy group containing the specified number of carbon atoms. For example, C 1-6 alkoxy means a straight or branched alkoxy containing at least 1, and at most 6, carbon atoms. Examples of “alkoxy” as used herein include, but are not limited to, methoxy, ethoxy, propoxy, prop-2-oxy, butoxy, but-2-oxy, 2-methylprop-1-oxy, 2-methylprop-2-oxy, pentoxy and hexyloxy. A C 1-4 alkoxy group is preferred, for example methoxy, ethoxy, propoxy, prop-2-oxy, butoxy, but-2-oxy or 2-methylprop-2-oxy.
[0043] The term “aryl” as used herein refers to an aromatic carbocyclic moiety such as phenyl, biphenyl or naphthyl.
[0044] The term “heteroaryl” as used herein, unless otherwise defined, refers to an aromatic heterocycle of 5 to 10 members, having at least one hetero atom selected from nitrogen, oxygen and sulfur, and containing at least 1 carbon atom, including both mono and bicyclic ring systems. Examples of heteroaryl rings include, but are not limited to, furanyl, thiophenyl, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, oxadiazolyl, tetrazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrazinyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, 1,2,3,4-tetrahydroisoquinolinyl, benzofuranyl, benzimidazolyl, benzothienyl, benzoxazolyl, 1,3-benzodioxazolyl, indolyl, benzothiazolyl, furylpyridine, oxazolopyridyl and benzothiophenyl.
[0045] The term “9 to 10 membered fused bicyclic heteroaryl” as used herein as a group or a part of a group refers to quinolinyl, isoquinolinyl, 1,2,3,4-tetrahydroisoquinolinyl, benzofuranyl, benzimidazolyl, benzothienyl, benzoxazolyl, 1,3-benzodioxazolyl, indolyl, benzothiazolyl, furylpyridine, oxazolopyridyl or benzothiophenyl.
[0046] The term “heterocyclyl” as used herein, unless otherwise defined, refers to a monocyclic or bicyclic three- to ten-membered saturated or non-aromatic, unsaturated hydrocarbon ring containing at least one heteroatom selected from oxygen, nitrogen and sulfur. Preferably, the heterocyclyl ring has five or six ring atoms. Examples of heterocyclyl groups include, but are not limited to, pyrrolidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, imidazolidinyl, pyrazolidinyl, piperidyl, piperazinyl, morpholino, tetrahydropyranyl and thiomorpholino.
[0047] The term “halogen” refers to a fluorine, chlorine, bromine or iodine atom.
[0048] The term “lower alcohol” refers to alcohols having between one and six carbons, including, but not limited to, methanol, ethanol, propanol, and isopropanol.
[0049] The term “aprotic solvent” refers to a solvent that is relatively inert to proton activity, i.e. not acting as a proton donor; examples include, but are not limited to, hydrocarbons such as hexane and toluene; halogenated hydrocarbons such as methylene chloride, ethylene chloride and chloroform; ethers such as diethylether and diisopropylether; acetonitrile; amines such as N,N-dimethylformamide, N,N-dimethylacetamide, and pyridine; and lower aliphatic ketones, such as acetone and dimethyl sulfoxide.
[0050] The term “protic solvent” refers to a solvent that displays a high degree of proton activity, i.e., is a proton donor; examples of protic solvents include, but are not limited to lower alcohols, such as methanol, ethanol, propanol, and isopropanol.
[0051] Suitable “pharmaceutically acceptable salts” are formed from inorganic or organic acids which form non-toxic salts and examples are hydrochloride, hydrobromide, hydroiodide, sulphate, bisulphate, nitrate, phosphate, hydrogen phosphate, acetate, trifluoroacetate, isonicotinate, salicylate, pantothenate, maleate, malate, fumarate, lactate, tartrate, bitartrate, ascorbate, citrate, formate, gluconate, succinate, pyruvate, oxalate, oxaloacetate, trifluoroacetate, saccharate, benzoate, alkyl or aryl sulphonates (e.g., methanesulphonate, ethanesulphonate, benzenesulphonate or p-toluenesulphonate), pamoate (i.e., 1,1′-methylene-bis-(2-hydroxy-3naphthoate)) and isethionate.
[0052] Typically, a pharmaceutically acceptable salt may be readily prepared by using a desired acid or base as appropriate. The salt may precipitate from solution and be collected by filtration or may be recovered by evaporation of the solvent. For example, an aqueous solution of an acid such as hydrochloric acid may be added to an aqueous suspension of a compound of formula (I) and the resulting mixture evaporated to dryness (lyophilized) to obtain the acid addition salt as a solid. Alternatively, a compound of formula (I) may be dissolved in a suitable solvent, for example an alcohol such as isopropanol, and the acid may be added in the same solvent or another suitable solvent. The resulting acid addition salt may then be precipitated directly, or by addition of a less polar solvent such as diisopropyl ether or hexane, and isolated by filtration.
[0053] Those skilled in the art of organic chemistry will appreciate that many organic compounds and their salts can form complexes with solvents in which they are reacted or from which they are precipitated or crystallized. These complexes are known as “solvates”. For example, a complex with water is known as a “hydrate” and a complex with ethanol is known as an “ethanolate”. Solvates of the compounds of this invention or salts thereof are within the scope of the invention.
[0054] In one aspect of the present invention, macrolide and azalide derivatives of formula (II) are dissolved in an inert organic solvent. Suitable solvents include, but are not limited to, protic and aprotic solvents, preferably, lower alcohols, acetonitrile, acetone, N,N-dimethylformamide, N,N-dimethylacetamide, pyridine, dichloromethane,ethyl-acetate, dimethyl sulfoxide, or ethers, and most desirably acetone, ethanol, acetonitrile or N,N-dimethylformamide.
[0055] To the dissolved macrolide or azalide the catalyst is added in a molar ratio of from about 1:0.05 to about 1:4, preferably from 1:0.25 to about 1:2.
[0056] Preferably, the catalyst is boric acid or a transition-metal halide, most desirably boric acid or TiCl 4 or SnCl 2 . To the reaction mixture a diazoalkane prepared according to the methods described in J. Org. Chem. 45 (1980) 5377-5378 or Org. Synth. Coll. Vol. 2 (1943) 165 is added. The resulting mixture is stirred at a temperature from about −20° C. to about the reflux temperature of the solvent, preferably from about 0° C. to about 40° C., and most desirably from about 15° C. to about 30° C. The mixture is stirred for a period from about 30 minutes to about 8 hours, preferably from about 1 hour to about 6 hours.
[0057] Isolation using standard methods (extraction, precipitation or the like) affords the desired 11-O-alkyl macrolide or azalide derivative in completely (100%) regioselective purity.
[0058] Compounds according to the invention exhibit a broad spectrum of antimicrobial activity, in particular antibacterial activity, against a wide range of clinical pathogenic microorganisms. Using a standard microtiter broth serial dilution test, compounds of the invention have been found to exhibit useful levels of activity against a wide range of pathogenic microorganisims. In particular, the compounds of the invention may be active against strains of Staphylococcus aureus, Streptococcus pneumoniae, Moraxella catarrhalis, Streptococcus pyogenes, or Haemophilus influenzae. The compounds of the present invention exhibit better activity against inducible ( S. pyogenes B0543) and efflux ( S. pyogenes B0545) resistant strains than the parent compounds. (Table 1.)
TABLE 1 MIC's of Selected Compounds 9-Deoxo-9a-aza- 8a-Aza-8a- 9a- homo- Microorganism homoerythromycin Ex. 3 erythromycin Ex. 5 S. aureus 4 1 2 0.5 B0329 S. pneumoniae 0.25 0.125 0.125 0.125 B0541 S. pneumoniae 16 8 64 32 B0326 M S. pyogenes 0.125 0.125 0.25 0.125 B0542 S. pyogenes 32 16 8 4 B0543 iMLS S. pyogenes 16 4 32 16 B0545 M M. catarrhalis 1 0.125 2 0.125 B0324 H. influenzae 0.5 0.5 1 1 B0529 E. coli B0001 4 2 16 16
[0059] The compounds of formula (VIIa) and (VIIb) may be administred orally or parenterally in conventional dosage forms such as tablet, capsule, powder, troches, dry mixes, ointment, suspension or solution prepared according to conventional pharmaceutical practices.
[0060] The compounds of formula (VIIa) and (VIIb) can be administred at a dosage of from about 1 mg/kg to about 1000 mg/kg of body weight per day. The preferred dosage range is from about 5 mg/kg to about 200 mg/kg of body weight per day.
[0061] The process of this invention will be best understood in connection with the following examples, which are intended as an illustration of and not a limitation upon the scope of the invention as defined in the appended claims.
[0000] Experimental:
[0062] Starting compounds were prepared according to published methods the disclosures of which are herein incorporated by reference.
[0000] Preparation of Diazomethane
[0000] Method A
[0063] Diazomethane was prepared according to the method and apparatus described in J. Org. Chem. 45 (1980) 5377-5378, starting from N-methyl-N-nitroso-p-toluensulfonamide (Diazald) and potassium hydroxide. A solution of Diazald in diethylether was added dropwise to a solution of KOH in water and ethanol. The yellow condensate of diazomethane was continuously introduced into the reaction mixture.
[0000] Method B
[0064] Diazomethane was prepared according to the method described in Org. Synth. Coll. Vol. 2 (1943) 165, starting from N-methyl-N-nitrosourea which was added portionwise to the mixture of 40% aq. KOH and diethyl or diisopropyl-ether at 0° C. with vigorous stirring. The phases were separated and the upper organic layer containing diazomethane was used for methylation.
EXAMPLE 1
11-O-METHYL-AZITHROMYCIN
[0000] Method I
[0065] Azithromycin (75 g, 0.1 mol) and boric acid (3.1 g, 0.05 mol) were dissolved in absolute ethanol (300 mL) and the yellow condensate of diazomethane (cca 0.27 mol) obtained in method A was continuously added to the the reaction mixture dropwise. The mixture was stirred at room temperature for 6 hours. A few drops of acetic acid were added to remove diazomethane excess. Ether was removed under reduced pressure followed by evaporation of ethanol to a volume of 200 mL. The product was percipitated by adding 400 mL of water. The crude product was dried in a vacuum oven for 12 hours at 40° C. Yield was 87%. The product was crystallized from ethanol/water to afford 100% pure (LC-MS analysis) 11-O-methyl-azithromycin in 73% yield.
[0066] ES-MS: m/z 763.2 (M+H), 605.3 (M+H-cladinose)
[0067] 1 H NMR(500 MHz, CDCl 3 ): δ(ppm) 3.59 (s, 3H, 11-OMe), 3.42 (d, 1H, 11-H), 3.25 (dd, 1H 2′-H), 3.03 (t, 1H, 4″-H)
[0068] 13 C NMR(125 MHz, CDCl 3 ): δ(ppm) 85.0 (11-C), 78.2 (4″-C), 70.9 (2′-C) 62.1 (11-OMe)
[0000] Method II
[0069] Azithromycin (1.012 g, 1.35 mmol) and boric acid (0.0885 g, 1.43 mmol) were dissolved in acetonitrile (20 mL) and stirred at RT for 1 hour. A solution of diazomethane in diethylether prepared by Method B (cca 6 mmol) was added and the resulting mixture was stirred at RT for 2 hours. The mixture was diluted with aq. NaHCO 3 (50 mL) and extracted with ethyl-acetate (3×30 mL). The organic layer was dried over Na 2 SO 4 , and concentrated to afford the title compound (0.702 g, yield 68%).
[0070] The compound of Example 1 was obtained in the same manner as described in Example 1, Method II, with the use of different solvents and catalysts as indicated in Table 2. Quantitative analysis of the final mixtures was performed by the LC-MS method.
TABLE 2 Preparation of 11-O-methyl azithromycin, according to Example 1. Yield of 11-OMe- Solvent Catalyst Azithromycin azithromycin By-product DMF SnCl 2 33% 47% 20% DMF H 3 BO 3 — 99% 1% MeCN H 3 BO 3 — 99% 1% MeOH H 3 BO 3 — 73% 23% acetone H 3 BO 3 2.5% 95% 2.5% diglyme H 3 BO 3 36.3% 61.6% 1.2% EtOH H 3 BO 3 — 72.7% 26.5% i-PrOH H 3 BO 3 39.3% 43% 17.5%
EXAMPLE 2
11-O-METHYL-2′-O,3′-N-DICARBOBENZOXY-AZITHROMYCIN
[0071] 2′-O,3′-N-Dicarbobenzoxy-azithromycin (J. Antibiotics 45 (1992) 527-534) (0.204 g, 0.203 mmol) and TiCl 4 (0.040 g, 0.210. mmol) were dissolved in DMF (5 mL) and stirred at RT for 1 hour. A solution of diazomethane in diethylether from Method B (cca 4 mmol) was added and the resulting mixture was stirred at RT for 6 hours. The mixture was diluted with aq. NaHCO 3 (50 mL) and extracted with ethyl-acetate (3×30 mL). The organic layer was dried over Na 2 SO 4 , and concentrated to afford the title compound.
[0072] ES-MS: m/z 1017.3 (M+H), 859.4 (M+H-cladinose)
EXAMPLE 3
11-O-METHYL-9-DEOZO-9A-AZA-9A-HOMOERYTHROMYCIN
[0073] 9-Deoxo-9a-aza-9a-homoerythromycin (J. Chem. Soc. Perkin Trans. 1 (1986) 1881-1890) (1.00 g, 1.36 mmol) and H 3 BO 3 (0.084 g, 1.36 mmol) were dissolved in acetonitrile (20 mL) and stirred at RT for 1 hour. A solution of diazomethane in diethylether prepared by Method B (cca 6 mmol) was added and the resulting mixture was stirred at RT for 2 hours. The mixture was diluted with aq. NaHCO 3 (50 mL) and extracted with ethyl-acetate (3×30 mL). The organic layer was dried over Na 2 SO 4 , and concentrated to afford the title compound (0.813 g, yield 80%).
[0074] ES-MS: m/z 749.6 (M+H), 591.5 (M+H-cladinose)
[0075] 1 H NMR(500 MHz, CDCl 3 ): δ(ppm) 3.56 (s, 3H, 11-OMe), 3.43 (d, 1H, 11-H), 3.30 (dd, 1H, 2′-H), 3.03 (t, 1H, 4″-H)
[0076] 13 C NMR(125 MHz, CDCl 3 ): δ(ppm) 84.3 (11-C), 78.1 (4″-C), 70.9 (2′-C) 62.4 (11-OMe)
EXAMPLE 4
11-O-METHYL-3-DECLADINOSYL-5-DEDESOSAMINYL-9-DEOXO-9A-AZA-9A-HOMOERYTHROMYCIN
[0077] 3-Decladinosyl-5-dedesosaminyl-9-deoxo-9a-aza-9a-homoerythromycin (J. Chem. Soc. Perkin Trans. 1 (1986) 1881-1890) (0.201 g, 0.48 mmol) and H 3 BO 3 (0.040 g, 0.64 mmol) dissolved in ethanol (20 mL) and stirred at RT for 1 hour. A solution of diazomethane in diethylether prepared by Method B (cca 3 mmol) was added and the resulting mixture was stirred at RT for 4 hours. The mixture was diluted with aq. NaHCO 3 (20 mL) and extracted with ethyl-acetate (3×20 mL). The organic layer was dried over Na 2 SO 4 , and concentrated to afford the title compound (0.106 g, yield 51%).
[0078] ES-MS: m/z 434.3 (M+H)
[0079] 1 H NMR(500 MHz, DMSO): δ(ppm) 4.64 (d, 1H, 3-OH), 3.68 (d, 1H, 5-OH), 3.48 (s, 3H, 11-OMe), 3.42 (t, 1H, 3-H), 3.31 (1H, 5-H), 3.18 (d, 1H, 6-OH), 3.14 (d, 1H, 11-H)
[0080] 13 C NMR(125 MHz, DMSO): δ(ppm) 85.6 (11-C), 83.1 (5-C), 79.7 (3-C), 73.3 (6-C) 61.4 (11-OMe)
EXAMPLE 5
11-O-METHYL-8A-AZA-8A-HOMOERYTHROMYCIN
[0081] 8a-Aza-8a-homoerythromycin (Bioorg. Med. Chem. Lett. 3 (1993) 1287) (1.00 g, 1.34 mmol) and H 3 BO 3 (0.084 g, 1.36 mmol) were dissolved in acetone (10 mL) and stirred at RT for 1 hour. A solution of diazomethane in diethylether prepared by Method B (cca 6 mmol) was added and the resulting mixture was stirred at RT for 4 hours. The mixture was diluted with aq. NaHCO 3 (50 mL) and extracted with ethyl-acetate (3×30 mL). The organic layer was dried over Na 2 SO 4 , and concentrated to afford the title compound (0.740 g, yield 71%).
[0082] ES-MS: m/z 763.3 (M+H), 605.3 (M+H-cladinose)
[0083] 1 H NMR(500 MHz, CDCl 3 ): δ(ppm) 3.48 (s, 3H, 11-OMe), 3.27 (dd, 1H, 2′-H), 3.17 (d, 1H, 11-H), 3.06 (t, 1H, 4″-H)
[0084] 13 C NMR(125 MHz, CDCl 3 ): δ(ppm) 79.5 (11-C), 77.5 (4″-C), 70.0 (2′-C) 59.9 (11-OMe)
EXAMPLE 6
11-O-METHYL-ROXITHROMYCIN
[0085] Roxithromycin (J. Antibiot 39 (1986) 660) (1.00 g, 1.20 mmol) and H 3 BO 3 (0.042 g, 0.68 mmol) were dissolved in acetone (10 mL) and stirred at RT for 1 hour. A solution of diazomethane in diethylether prepared by Method B (cca 6 mmol) was added and the resulting mixture was stirred at RT for 4 hours. The mixture was diluted with aq. NaHCO 3 (50 mL) and extracted with ethyl-acetate (3×30 mL). The organic layer was dried over Na 2 SO 4 , and concentrated to afford a mixture of the title and starting compounds (70%:30% LC-MS).
[0086] ES-MS: m/z 851.3 (M+H)
[0087] 1 H NMR(500 MHz, CDCl 3 ): δ(ppm) 3.63 (s, 3H, 11-OMe), 3.53 (d, 1H, 11-H), 3.33 (1H, 2′-H), 3.03 (1H, 4″-H)
[0088] 13 C NMR(125 MHz, CDCl 3 ): δ(ppm) 79.8 (11-C), 77.9 (4″-C), 70.9 (2′-C) 62.1 (11-OMe)
EXAMPLE 7
11 -O-METHYL-CLARITHROMYCIN
[0089] Clarithromycin (J. Antibiot. 43 (1990) 544-549) (1.00 g, 1.34 mmol) and SnCl 2 2H 2 O (0.307 g, 1.36 mmol) were dissolved in DMF (10 mL) and stirred at RT for 1 hour. A solution of diazomethane in diethylether prepared by Method B (cca 6 mmol) was added and the resulting mixture was stirred at RT for 4 hours. The mixture was diluted with aq. NaHCO 3 (50 mL) and extracted with ethyl-acetate (3×30 mL). The organic layer was dried over Na 2 SO 4 , and concentrated to afford a mixture of the title and starting compounds (24%:73% LC-MS).
[0090] ES-MS: m/z 762.4 (M+H) 604.3 (M+H-cladinose)
EXAMPLE 8
11-O-METHYL-3-DECLADINOSYL-5-DESOSAMINYL-9-DEOXO-9A-AZA-9A-HOMOERYTHROMYCIN A
[0091] Starting from 3-decladinosyl-5-desosaminyl-9-deoxo-9a-aza-9a-homoerythromycin A (J. Chem. Soc. Perkin Trans. 1 (1986) 1881-1890) the title compound is prepared according to the procedure described in Example 4.
EXAMPLE 9
11-O-METHYL-3-DECLADINOSYL-5-DESOSAMINYL-8A-AZA-8A-HOMOERYTHROMYCIN A
[0092] a) Starting from 8a-aza-8a-homoerythromycin A (Bioorg. Med. Chem. Lett 3 (1993) 1287) the 3-decladinosyl-5-desosaminyl-8a-aza-8a-homoerythromycin is prepared according to the procedure described in Example 4 of International Patent Application WO99/51616.
[0093] b) Starting from the compound prepared in Step a) the title compound is prepared according to the procedure described in Example 4.
EXAMPLE 10
11-O-METHYL-3-DECLADINOSYL-5-DEDESOSAMINYL-8A-AZA-8A-HOMOERYTHROMYCIN A
[0094] a) Starting from the compound prepared in Example 9, Step a) the desosamine is cleaved according to the procedure published in J. Chem. Soc. Perkin Trans. 1 (1986) 1881-1890 for compound 13.
[0095] b) Starting from the compound prepared in Step a) the title compound is prepared according to the procedure described in Example 4.
EXAMPLE 11
6,11-DI-O-METHYL-8A-AZA-8A-HOMOERYTHROMYCIN A
[0096] Starting from 6-O-Methyl-8a-aza-8a-homoerthromycin A (WO99/51616, Example 3) the title compound is prepared according to the procedure described in Example 4.
EXAMPLE 12
6,11-DI-O-METHYL-3-DECLADINOSYL-5-DESOSAMINYL-8A-AZA-8A-HOMOERYTHROMYCIN A
[0097] Starting from 3-decladinosyl-6-O-Methyl-8a-aza-8a-homoerthromycin A (WO99/51616, Example 5) the title compound is prepared according to the procedure described in Example 4.
EXAMPLE 13
6,11-DI-O-METHYL-3-DECLADINOSYL-5-DEDESOSAMINYL-8A-AZA-8A-HOMOERYTHROMYCIN A
[0098] a) Starting from 3-decladinosyl-6-O-Methyl-8a-aza-8a-homoerthromycin A (WO99/51616, Example 5) the desosamine is cleaved according to the procedure published in J. Chem. Soc. Perkin Trans. 1 (1986) 1881-1890 for compound 13.
[0099] b) Starting from the compound prepared in Step a) the title compound is prepared according to the procedure described in Example 4.
EXAMPLE 14
HYDROCHLORIDE SALT OF 11-O-METHYL-AZITHROMYCIN
[0100] 11-O-Methyl-azithromycin of Example 1 (1.0 g, 1.31 mmol) was dissolved in i-PrOH (20 ml) and a few drops of dichloromethane and then HCl (5M solution in i-PrOH, 2.05 eqv) was added. The hydrochloride salt was isolated by precipitation with (i-Pr) 2 O giving 0.85 g of the title compound.
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The present disclsoure relates to new 11-O-alkyl macrolides and azalides and pharmaceutically acceptable salts and solvates thereof, and to pharmaceutical compositions thereof. The disclosure also relates to a process for the preparation of 11-O-alkyl macrolides and azalides by regioselective 11-O-alkylation of macrolides and azalides having a vicinal diol system, using diazoalkanes in the presence of transition-metal halides or boric acid as catalysts. In another aspect, the disclosure relates to uses of the 11-O-alkyl macrolides and azalides as antibacterial agents or intermediates for the synthesis of other antibacterial agents.
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BACKGROUND OF THE INVENTION
The invention relates to a container for the handling of semiconductor devices, and a process for particle-free transfer.
A container is known in which semiconductor slices, so-called wafers, are transported from one clean space into another clean space. The semiconductor wafers are used for the production of microchips and may only be processed in extremely clean rooms. Care must therefore be taken that these semiconductor wafers are not contaminated during transit. For this reason, the clean space is entirely enclosed in the case of the known container. The bottom of this container is removable, so that the carrier with the semiconductor wafers can be introduced into the clean space of the container or can be taken out of it. This container can only be opened under clean room conditions, as otherwise dirt particles immediately reach the semiconductor wafers and may settle on them. A considerable effort is necessary for the airtight closure of this container. In addition, there is the risk that the closure can become damaged so that dirt particles or dust particles reach the clean space and contaminate the semiconductor wafers. The air still in the clean space also has dust particles and dirt particles in it even with extreme purity, so that there is the risk that these dirt particles will reach the semiconductor wafers even with a satisfactory closure. The chemicals used in semiconductor processing develop gases which, if contained for prolonged periods in the enclosed clean space, may enrich to such an extent that they adversely change the surface of the semiconductor wafers.
Concerning the particle-free transfer of semiconductor wafers, it is known to connect the airtight closed container to the wall of a separate loading station and then to open the bottom of the container. However, in so doing care must be taken that no dirt particles can pass into the container and/or the loading station from the surrounding air polluted with dirt particles. Consequently, the area of the container connected to the loading station must be sealed off, in an elaborate way, with seals and the like. As a result, however, there is the risk that the seal is faulty or not correctly fitted, in which event the dirt particles can pass from the surrounding air through the untight sealing point into the container and/or the loading station.
SUMMARY OF THE INVENTION
An objective of the invention is to design a container of the generic type, and a corresponding handling process, in such a way that, with simplest structural design, no contamination occurs in the clean air zone, even if the container is stored or handled under unclean room conditions. In particular, it is intended to ensure, without great structural expenditure, in the critical transfer between two clean air zones that no dirt particles reach the clean air zones from the surrounding space.
The semiconductor devices in the clean air zone of the container according to the invention constantly have the directed clean air stream passing around them, so that any dirt particles or dust particles carried along by this air stream cannot settle on the semiconductor devices. Since the semiconductor devices constantly have the clean air stream flowing around them, the gases forming are taken along by the flow, so that they cannot attack the surface of the semi-conductor devices. In addition, the semiconductor devices can also be stored for a lengthy period of time, without fear of damage, since during storage the semiconductor devices likewise constantly have the clean air stream passing around them. Owing to this clean air stream, access of the surrounding air to the clean air zone of the container according to the invention is reliably prevented. Consequently, the container according to the invention can also be transported through contaminated rooms, without the risk that dirt particles reach the clean air zone. Since the container does not have any seals, the disadvantages associated with seals do not exist. In addition, the carrier with the semiconductor devices is easily accessible, so that the further handling of the container according to the invention can be carried out fully automatically without any trouble.
In the case of the process according to the invention, the particle-free transfer of the products can be carried out without the critical transfer zone having to be sealed off from the surrounding space by separate sealing elements and the like. Since both clean air zones have the clean air flowing through them and at least in the one clean air zone there prevails a higher static pressure than in the surrounding space, a forced flow from the clean air zone along the rim of the respective transfer opening to the outside is achieved, and an ingress of dirt particles from the surrounding space is reliably prevented. Thus, no mechanical sealing elements and the like are necessary in the case of the process according to the invention.
Further features of the invention will be apparent from the description which follows.
BRIEF DESCRIPTION OF THE APPLICATION DRAWINGS
The invention is explained in more detail with reference to two exemplary embodiments represented in the drawings, in which
FIG. 1 shows, in elevation and diagrammatic representation, a first embodiment of a container according to the invention;
FIG. 2 shows the loading operation of a process apparatus with carrier accommodated in a container according to FIG. 1;
FIG. 3 shows several containers according to the invention arranged on a transport carriage;
FIG. 4 shows, in diagrammatic representation, a second embodiment of a container according to the invention, and
FIGS. 5 and 6 show generally diagrammatically embodiments according to the invention for transporting products between two clean air zones.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Carriers 1 are transported with the container, with semiconductor slices 2, so-called wafers, being arranged in and supported by the carrier. These semiconductor wafers 2 are used for the production of microchips. The semiconductor wafers 2 may only be handled and transported in extremely clean rooms, because even minute dirt or dust particles make the semiconductor wafers unusable for further processing.
The container according to FIG. 1 has a rectangular plan outline with four side walls, one of which is the front wall 3 and two of which are mutually opposite side walls 4 and 5 are shown in FIG. 1. In the clean space 6 enclosed by the walls, the carrier 1 is mounted in suspended manner. For this, it is provided at its upper end with a flange-like extension 7, which interacts with catches 8 which are provided on the inside of the side walls of the container. Clip connections or the like could also be used. The clean space 6 is closed at the top by at least one high efficiency suspended substance filter 9, above which a fan unit 10 is arranged. The fan takes in air from the surrounding space, which then flows through the filter 9. It filters out the dust and dirt particles contained in the air, so that clean air flows into the underlying clean space 6. In the exemplary embodiment according to FIG. 1, the clean air is directed to flow from top to bottom, flowing evenly through the clean space 6 over its entire cross-section in a direction which is approximately laminar. The semiconductor wafers 6 are arranged upright in the carrier 1, so that the clean air flows downwardly over the sides of all semi-conductor wafers 2.
The container is open on the side opposite the fan unit 10, the bottom as shown in FIG. 1, so that the clean air flowing approximately laminarly downwards flows out of the clean space 6 at the open end.
The fan unit 10 may also be arranged on a side wall of the container, so that the clean air flows horizontally through the clean space 6. In this case, the container is open on the side opposite to the fan, and the bottom of the container is closed. The semiconductor wafers 2 then lie in or parallel to the flow direction, so that the clean air can flow by them.
Depending on the degree of purity desired, a corresponding high efficiency suspended filter 9 is used. In this manner, the air entering the clean space 6 has the desired degree of purity. This directed laminar flow has the effect of carrying along any particles that may be in the clean space 6 and passing such particles to the outside. The particles thus cannot settle on the semiconductor wafers 2. Owing to this flow, the container can be transported without any risk even through rooms of lower purity class, in which there may thus also be a relatively high number of dirt or dust particles. The directed flow in clean space 6 always prevents any dirt or dust particles from passing into the container and being able to settle on the semiconductor wafers 2.
In semiconductor processing, chemicals are used which result in the formation of gas. Since the semiconductor wafers 2 constantly have clean air flowing around them, these gases forming are removed by the air flow so that they cannot attack the surface of the semiconductor wafers.
For operation of the fan unit 10, the container is equipped with at least one accumulator 11, or a battery, by which the fan unit can be driven. If the container is at an unloading or loading point or at a storage point, it is connected to the power line or to a larger accumulator. For this, the container is provided with a connection 12 or with an interface, so that the fan unit 10 can then be supplied externally with the necessary power. At the same time, the accumulator 11 is thereby charged.
The flow velocity in the clean space 6 of the container is chosen such that no air can pass into the clean space from outside during normal handling. The flow velocity is expediently approximately 0.45 m/sec. This flow velocity has been found appropriate in the case of large clean rooms. Owing to this flow velocity, a slight dynamic pressure forms in the clean space 6, relative to the pressure in the contaminated surrounding space.
To increase the static positive pressure, it is expedient to provide a perforated plate on the underside of the container at the outlet end of the clean air. The positive pressure is then of an order of magnitude of approximately 1 Pa. The perforated sheet only slightly impairs the uniformity of the directed flow in the clean space 6.
The container according to FIG. 1 is of low weight and can consequently be transported comfortably by hand. The loading of the container with the carrier 1 and the semiconductor wafers 2 is performed under conditions appropriate for a clean room. If the container is transported by hand, the fan unit 10 is operated by means of the internal accumulator 11, so that clean air constantly flows outwards past the semiconductor wafers 2. The container serves the purpose of transporting the semiconductor wafers 2 from the loading point, for example, to a process apparatus 13 (FIG. 2), in which the semiconductor wafers are further processed. The container with the carrier 1 and semiconductor wafers 2 is removed at the process apparatus 13 under conditions appropriate for a clean room, so that the purity conditions which prevail in the container are not worsened during the removal operation. This removal operation is consequently performed either in the clean room or at or in the process apparatus 13. In the exemplary embodiment, the process apparatus 13 has an unloading space 14, which has clean air flowing through it from top to bottom, approximately laminarly. This unloading space 14 is covered at the top by at least one high efficiency suspended substance filter 15, above which there is a fan unit 16. The fan takes in air from the surrounding space and forces the air through the filter 15, which filters out the dirt and dust particles. The filter 15 is selected in accordance with the purity conditions required.
When unloading the container, the carrier 1 with the semiconductor wafers 2 continues to have clean air passing around it laminarly, so that no dirt or dust particles can settle on them. Since there is such a laminar flow in the unloading space 14 as well, the depositing of such contaminants on the semiconductor wafers 2 can also be reliably prevented here as well in a very simple way.
When the container is at or in the process apparatus 13, the fan unit 10 is driven by the power supply of the process apparatus 13, via the connection 12, and at the same time the internal accumulator 11 of the container is charged.
Since the container is open on one side, the carrier 1 with the semiconductor wafers 2 can be removed from the clean space 6 in a simple way.
An embodiment is also possible in which the container does not have any side walls bounding the clean space 6. The carrier in this embodiment is suspended on a holder located underneath or next to the filter 9. The air stream generated by the fan 10 similarly passes around the semiconductor wafers 2 and prevents the access of dirt particles from the surrounding air to the surfaces of the wafers.
The carrier 1 may have different sizes, depending on the size of the semiconductor wafers 2 to be transported. In the case of larger carriers 1, the container may have a higher weight, so that it is difficult to transport the container by hand. In such event, a transport carriage 17 is provided (FIG. 3), on which the containers can be positioned. Several containers are positioned on the carriage 17 in the FIG. 3 showing. In order that the air leaving the containers downwards from the clean space 6 is not diverted back into the clean space, the containers stand on supports, not shown in more detail, so that the directed flow can leave the containers downwards out of the clean space. On the transport carriage 17 there are bearings 18, on which the containers rest. These bearings may be designed as roller bearings or as air bearings, whereby the containers can be shifted from the transport carriage onto, for example, the process apparatus 13. The transport carriage 17 is provided with a connection 19 for the power supply and with a connection 20 for a vertical adjustment at least of the support surface for the containers
The containers can be taken to the process apparatus 13 on the transport carriage 17. During the trip on the transport carriage 17, the fan units 10 of the containers are connected to the power supply of the transport carriage, it being possible at the same time for the accumulators 11 of the containers to be charged via this power supply. This ensures that the containers operate reliably during transit on the carriage 17 and that the downwardly directed laminar flow takes place in the respective clean spaces 6.
The transport carriage 17 is adapted to be connected to the process apparatus 13, as FIG. 2 shows. For this, the process apparatus 13 is provided with a connection 21, to which the transport carriage 17 is connected for the power supply. In this case, the containers on the transport carriage are also supplied with the necessary power to drive the fan units 10. In addition, the connection 20 of the transport carriage 17 is connected to a corresponding connection (not shown) of the process apparatus 13, so that, in the position represented in FIG. 2, the support surface provided by the bearings 18 can be vertically adjusted. Consequently, the bearing surface 22 can be made to match the bearing surface 23 of the process apparatus 13, such that the containers can be shifted from the transport carriage onto the process apparatus without difficulties.
At the transfer point or area 24 of the process apparatus 13 there is at least one lifting device 25, by which the carriers 1 of the containers, with the inserted semiconductor wafers 2, can be taken out of the container and transported into the process apparatus 13.
The containers shifted into the transfer point 24 are raised into the position represented in FIG. 2. Subsequently, the lifting device is used to move up a gripping unit 26, the grippers 27 of which enter the clean space 6 of the respective container and grasp the carrier 1 kept there With the grippers 27, the carrier 1 is then released from the catches 8 and lowered downwards into the position represented in FIG. 2. In so doing, the entire gripping unit 26 is lowered by means of the lifting device 25. On the piston rod 28 of the lifting device 25 there is a mounting plate 29, on which the grippers 27 are pivotally mounted. The pivoting of the grippers 27 is served by a piston-cylinder unit 30, which is likewise pivoted on the bearing plate 29 and hinge-connected to the grippers 26. When the gripping unit 26 has been lowered into the position represented in FIG. 2, the piston-cylinder unit 30 is actuated and the grippers 26 are pivoted clockwise (see arrow in FIG. 2) with the carriers 1 and brought into the unloading space 14 of the process apparatus 13. In the unloading space 14, the carrier 1 is then set down. The grippers 27 are swung back again and the gripping unit 26 is lowered by the lifting device 25 underneath the bearing surface 23. During the transfer operation described, clean air flows out of the respective container and also downwardly through the discharge space 14 of the process apparatus 13, so that the semiconductor wafers 2 in the carrier 1 constantly have clean air passing around them. This ensures that no dirt particles or dust particles can settle on the semiconductor wafers during this transfer operation.
In the unloading space 14, which represents a clean space, the bearing surface for the carriers 1 may be formed by a perforated plate, a grid or some other air-permeable supporting part. With this, the necessary positive pressure in the unloading space 14, relative to the pressure in the contaminated surrounding space, can be generated in a simple way without substantially disturbing the laminar directed flow in the unloading space 14.
In the area of the transfer point, the corresponding wall of the unloading space 14 is provided with a transfer opening (not shown), through which the carriers 1 are transported by the gripping unit 26 into the unloading space. In the exemplary embodiment shown, the transfer point 24 is open in the direction of the transport carriage 17. Owing to the positive pressure in the unloading space 14, the air flows through the transfer opening in the wall facing the transfer point 24, the air flowing from top to bottom out of the container thereby being correspondingly deflected. This reliably prevents contaminated air reaching the semiconductor wafers 2 from the surrounding space during the transfer operation described.
In the case of another embodiment (not shown), 5 the transfer point 24 is surrounded by side walls, of which the side wall facing the transport carriage 17 has a transfer opening, in order that the container can be brought from the transport carriage into the transfer point. This transfer opening is preferably closable and is closed after bringing the container into the transfer point 24. The air flowing out of the container has the effect of then building up a positive pressure in the transfer point 24, relative to the pressure in the surrounding space. The transfer point 24 is closed at the top by the raised container (FIG. 2). This positive pressure in the transfer point 24 is equal to or approximately equal to the positive pressure in the unloading space 14. Consequently, the container need no longer be sealed off from the side walls of the transfer point 24 and the neighboring wall 35 of the unloading space 14. Owing to the positive pressure, the clean air flows in the gap between the container and the corresponding wall of the unloading space 14 on all sides to the outside and thereby prevents the access of contaminated air from the surrounding space. Consequently, no special sealing measures have to be provided. Owing to this outwardly directed flow on all sides, a particle-free transfer zone is formed, so that the semiconductor wafers 2 can be brought out of the container into the unloading space 14, and vice versa, without risk of contamination.
Instead of the gripping unit 26, any other suitable transport device may be used in order to transport the carriers 1 into the unloading space 14 and out of it. Since the container does not have any bottom, nor are corresponding opening and closing mechanisms necessary in the process apparatus 13, the carriers 1 can be removed immediately from the container, from the opened side.
FIG. 4 shows a second embodiment of a container, which is of larger design and is mobile. The container is designed as a transport carriage, by which not only one, but several carriers 1 with semiconductor wafers can be transported. The carriers 1 in turn rest on bearings 18a, which are of the same design as the bearings 18 according to FIG. 3. They are located on a transport carriage unit 31, in which an accumulator 32 for the power supply of the fan unit 10a is accommodated. The fan unit 10a expediently has several fans, so that all carriers 1 with the semiconductor wafers have the downwardly directed flow passing evenly around them. Similar to the fan unit of the above embodiment, the fan unit 10a has the same plan outline as the container. Underneath the fan unit 10a there is again at least one high efficiency suspended substance filter 9a, in which the dirt and dust particles in the air taken in are filtered. The type of high efficiency suspended substance filter 9a again depends on the degree of purity desired in the clean space 6a. In it, the carriers 1 are arranged next to one another. All semiconductor wafers (not shown) mounted in the carriers 1 have the clean air flowing around them in the manner previously described, so that a depositing of dirt or dust particles on the semiconductor wafers is reliably prevented. The carriers 1 may rest on a perforated sheet or else be mounted in suspended manner in the clean space 6a. In any case, the clean space 6a is designed in such a way that the approximately laminarly flowing clean air can flow unhindered further downwards past all of the semiconductor wafers.
The clean space 6a is designed in such a way that the semiconductor wafers in the carriers cannot be contaminated during manual unloading or during manual loading. This is achieved by the clean space 6a being designed such that the hand of the operator with the particular carrier 1 seized cannot be moved over the other carriers. The hand of the operator itself can also not reach into the area above the carriers 1. Otherwise, the dirt particles on the hand could be carried along by the flowing air in the clean room 6a and reach the semi-conductor wafers underneath. The space between the carriers 1 and the filter 9a is designed narrow enough that the hand of the operator cannot reach into this gap area. The filter 9a is also guarded against being touched or damaged. For this purpose, a perforated plate (not shown) or a rib mesh is provided on the underside of the filter 9a.
In the clean space 6a, the flow velocity is again high enough for a certain positive pressure to be formed with respect to the contaminated surrounding space. The usual value for the flow velocity in the clean space 6a is approximately 0.45 m/sec, although this can be varied.
With the transport carriage unit 31, the carriers 1 can travel to the process apparatus 13 and be brought there into the unloading space 14. Since several carriers 1 are provided in the container, the housing part 33 enclosing the clean space 6a is raised with the filter 9a and the fan units 10a, for which purpose corresponding lifting devices 34 are provided on the transport carriage unit 31. After the raising of the housing part 33, the carriers 1 may be pushed directly from the transport carriage unit 31 into the unloading space 14 of the process apparatus 13. In this case, the process apparatus no longer requires the lifting unit 25 and the gripping unit 26.
With the containers described, it is possible in a structurally simple way to transport the sensitive semiconductor wafers 2 in the processing state even through contaminated rooms. The approximately laminar flow of clean air generated in the containers ensures that all semiconductor wafers in the container have clean air flowing around them on all sides, so that any dirt or dust particles there may be in the clean space are carried along and cannot settle on the semiconductor wafers. Furthermore, the containers are of structurally simple design and do not require any special seals which would be susceptible to faults and would make handling considerably more difficult. Rather, the containers are constantly open on one side, which not only eliminates the sealing problems but also makes handling of the containers extremely simple.
FIG. 5 shows a possibility of transferring the semiconductor wafers from one container into the other container without the transfer zone having to be sealed off from the surrounding space. The left container 36 in FIG. 5 has on its one side wall 37 a transfer opening 38. The neighboring container 39 is likewise provided with a transfer opening 40. The two transfer openings 38 and 40 may be the same size, or of different sizes, as is shown in FIG. 5. Both containers 36 and 39 have at least approximately laminar clean air flowing through them in the way described, which is indicated by arrows in FIG. 5. In the clean space 6 of these two containers, again a positive pressure is built up in the way described, relative to the positive pressure in the surrounding space 41. This positive pressure is marked in the two containers 36 and 39 by "+". The pressure in the surrounding space 41 is given in FIG. 5 by "±0". The positive pressure in the clean spaces 6 may be formed by a perforated plate 42 or another air-permeable supporting part. Underneath this perforated plate 42, the air can either flow unhindered downwards or be deflected at a bottom located at a distance underneath the perforated plate.
If, for transfer of the semiconductor wafers, the two containers 36 and 39 are brought into the position represented in FIG. 5, in which their transfer openings 38 and 40 lie alongside each other, the area surrounding these transfer openings does not have to be sealed off from the surrounding space 41. Owing to the positive pressure in both containers 36 and 39, the clean air flows in the direction of the arrows drawn on all sides along the area surrounding the transfer openings into the surrounding space 41. This achieves, in a structurally very simple way, a satisfactory sealing off of the clean spaces 6 from the surrounding space 41, i.e. no dirt particles can pass from the surrounding space 41 into the clean space 6. The positive pressures in the two clean spaces 6 are equal or at least approximately equal. Owing to the sealing described against ingress of dirt particles, a particle-free transfer zone 43 is formed between the two containers 36 and 39, in which zone the semiconductor wafers can be transferred without risk of contamination.
Instead of one or the other of containers 36 or 39, a stationary clean space with a corresponding transfer opening may also be provided. This stationary clean space may be provided at a process apparatus or may, for example, also be a walk-in large clean room.
FIG. 6 shows the possibility of transferring the semiconductor wafers from a container into a walk-in clean room 44 without risk of contamination. It likewise has clean air flowing through it approximately laminarly (see arrows in FIG. 6). The container 45 is provided on one side wall with a transfer opening 46 which, in the transfer position according to FIG. 6, lies alongside a transfer opening 47 of the clean room 44. The positive pressure in the clean room 44, marked by "+", is generated by a perforated double bottom 48 or the like. The air is taken in by a fan unit (not shown) and pressed through at least one high efficiency suspended substance filter 49 into the clean room 44.
In the clean space 6 of the container 45, the positive pressure is generated in the way described by a perforated plate 50 or the like.
In the transfer position according to FIG. 6, the flow path of the clean air, indicated by arrows in FIG. 6, is achieved owing to the equal or approximately equal positive pressure in the two clean spaces 44 and 6, relative to the pressure "±0" in the surrounding space 41. The clean air flows on all sides along the rim of the transfer openings 46, 47 between the container 45 and the corresponding wall of the clean room 44 to the outside and thus prevents the access of dirt particles from the surrounding space 41 through the gap area 51 between container and clean room wall.
It is also possible to place the container directly with the open side opposite the fan unit (without perforated plate) against the respective transfer opening of the other container 39 or of the clean room 44. The transfer opening of the container is thereby formed by the open side of this container. In this case, the flow in this container is directed oppositely to the air leaving the transfer opening of the other container or of the clean room 44. In this case as well, the access of dirt particles from the surrounding space can be reliably prevented by matching of the two pressures without additional sealing measures.
The exemplary embodiments have been described with reference to semiconductor wafers 2. It goes without saying that the containers and the transfer process can also be applied everywhere where handling of articles in a clean room or under conditions appropriate for a clean room is important. For example, it is possible to use this container for medicaments, chemicals, in the field of genetic engineering, virology and the like.
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The container and transfer process are intended to prevent stop contamination of semiconductor devices from occurring, even if the container is stored or handled under unclean room conditions. The semiconductor devices are subjected to an approximately laminar clean air stream passing around them in a clean air zone. A higher static pressure is maintained in the clean air zone than in the surrounding space which might be polluted with an inadmissibly high number of particles. The clean air stream carries along any dirt particles there may still be, so that they cannot settle on the semiconductor devices. Owing to the higher static pressure, a forced flow from the clean air zone of the higher static pressure outwards into the surrounding space is achieved, thus preventing an ingress of dirt particles from the surrounding space.
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FIELD OF THE INVENTION
The present invention relates to compositions that can be used as refrigerant fluids. The invention more particularly relates to compositions whose contribution to the greenhouse effect is very low, which may be used in refrigeration and the production of conditioned air.
BACKGROUND OF THE INVENTION
The problems posed by substances that deplete the atmospheric ozone layer were addressed at Montreal, where the protocol was signed imposing a reduction in the production and use of chlorofluorocarbons (CFC). This protocol underwent amendments which imposed the phasing out of CFCs and extended the regulation to other products, including hydrochlorofluorocarbons (HCFC).
The refrigeration and conditioned-air production industry has invested greatly in the replacement of these refrigerant fluids, and hydrofluorocarbons (HFC) have accordingly been marketed.
In the motor vehicle industry, the air-conditioning systems of vehicles marketed in many countries swapped from a chlorofluorocarbon refrigerant fluid (CFC-12) to a hydrofluorocarbon refrigerant fluid (1,1,1,2-tetrafluoroethane: HFC-134a), which is less harmful to the ozone layer. However, with regard to the objectives set by the Kyoto protocol, HFC-134a (GWP=1300) is considered as having a high warming potential. The contribution to the greenhouse effect of a fluid is quantified by the GWP (global warming potential), which summarizes the warming potential, taking a reference value of 1 for carbon dioxide.
The majority of refrigeration installations operate on the principle of the vapor compression cycle. According to this principle, a refrigerant fluid is evaporated at low pressure, by taking heat from a first surrounding medium. The vapor thus formed is then compressed by means of a compressor and then passed into a condenser in which it is converted into liquid form, giving rise to a release of heat in a second surrounding area. The liquid thus condensed then circulates in an expansion vessel, at the outlet of which it is converted into a two-phase mixture of liquid and vapor, which is finally introduced into the evaporator where the liquid is again evaporated at low pressure, which completes the cycle. In a supercritical cycle, there is no condensation, and the condenser is referred to as a cooler.
Regulating the expansion vessel allows control of the overheating at the compressor inlet and optimizes the functioning of the installation.
The yield of a compression system depends on the components, the architecture of the system, the operating conditions and the fluid. The fluids used may be pure substances or azeotropic or zeotropic mixtures. The temperature glide of a fluid is defined as being the difference in temperature between the bubble point and the dew point at constant pressure. In compression systems with a supercritical cycle, the temperature glide is considered as being the difference in temperature between the inlet and outlet of the cooler.
In a theoretical compression cycle, the phase changes (condensation/evaporation) are at constant pressure. With one-component fluids and azeotropic mixtures, the condensation and evaporation are at constant temperature. The temperature glide is then zero.
Air-conditioning units, refrigeration machines and heat-exchange pumps operate on the same principles.
Since carbon dioxide is nontoxic, nonflammable and has a very low GWP, it has been proposed as a refrigerant for air-conditioning systems as a replacement for HFC-134a. However, the use of carbon dioxide has many drawbacks, especially associated with the very high pressure of its use as a refrigerant fluid in existing devices and techniques.
The use of carbon dioxide alone in a supercritical cycle or in combination with other compounds, such as HECs, in a refrigeration system or a common heat-exchange pump may thus lead to unacceptable reductions in energy efficiency if the surrounding medium (air, water or glycol-water) does not have a temperature glide as high as that of the fluid used. The consequence is that the difference between the mean temperature of the phase change of a mixture comprising carbon dioxide and the mean temperature of the surrounding medium increases, thus resulting in an increase in the difference between the evaporation and cooling pressures, which has the direct consequence of reducing the energy efficiency of the refrigeration system or of the heat-exchange pump. This energy efficiency also decreases following the degradation of efficiency of the exchangers as a result of the variation of the difference in temperatures between the refrigerant fluid and the surrounding medium across the exchanger.
Document U.S. Pat. No. 6,073,454 discloses the use of a co-fluid in combination with carbon dioxide as a refrigerant for reducing the working pressure. However, the refrigeration performance is insufficient.
DETAILED DESCRIPTION OF THE INVENTION
Compositions that can be used as refrigerant fluids and that have a low GWP have now been found. The GWP of the compositions according to the present invention is preferably not more than 150.
The compositions according to the present invention comprise at least one compound (A) chosen from the group constituted by hydrotluorocarbons, (hydro)fluoro-olefins, (hydro)fluoroiodocarbons and hydrocarbons, at least one compound (B) chosen from the group constituted by rare gases, nitrogen, nitrogen dioxide, hydrogen sulfide and carbon dioxide, and at least one functionalized organic compound (C) with a boiling point at atmospheric pressure of greater than 60° C.
The functionalized organic compound (C) preferably has a melting point at atmospheric pressure of less than −20° C. and/or a flash point>50° C. and advantageously >10° C.
These compositions preferably comprise from 5% to 90% by weight of compound(s) (A), from 5% to 40% by weight of compound(s) (B) and from 5% to 55% by weight of compound(s) (C).
These compositions advantageously comprise from 15% to 80% by weight of compound(s) (A), from 10% to 40% by weight of compound(s) (B) and from 10% to 45% by weight of compound(s) (C).
Hydroflucrocarbons that may especially be mentioned include difluoromethane, difluoroethane, 1,1,1,2-tetra-fluoroethane, 1,1,2,2-tetrafluoroethane, pentafluoroethane, pentafluoropropane, heptafluoropropane and pentafluorobutane. Difluoromethane, difluoroethane and 1,1,1,2-tetrafluoroethane are preferred.
When 1,1,1,2-tetrafluoroethane is present in the composition, it preferably represents not more than 10% of the total weight.
(Hydro)fluoroolefins that may especially be mentioned include (hydro)fluoroethylenes, (hydra)fluoropropylenes and (hydro)fluorobutylenes. (Hydro)fluoropropylenes are preferred.
(Hydro)fluoropropylenes that may especially be mentioned include difluoropropylene (HFO-1252), tri-fluoropropylene (HFO-1243), tetrafluoropropylene (HFO-1234) and pentafluoropropylene (HFO-1225). The preferred hydrofluoropropylenes are 1,3,3,3-tetra-fluoropropylene (HFO-1234ze), 2,3,3,3-tetrafluoropro-pylene (HFO-1234yf) and 1,2,3,3,3-pentafluoropropylene (HFO-1225ye), and also each of the stereoisomers thereof. Perfluoropropylene may also be suitable for use. 2,3,3,3-Tetrafluoropropylene (HFO-1234yf) is particularly preferred.
A (hydro)fluoroiodocarbon that may be mentioned is trifluoroiodomethane (CF 3 I).
Carbon dioxide is preferably chosen as compound (B).
Functionalized organic compounds (C) that may especially be mentioned include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, 1,3-butanediol, diacetone alcohol, (C 6 H 12 O 2 ), diethyl carbonate, propylene carbonate, 4-methyl-1,3-dioxolan-2-one, N,N-diethylformamide, cyclohexylamine, aniline, diethylamine, 4-hydroxy-4-methylpentanone, 2-methyl-2-pentanol-4-one, 3-methoxy-3-methyl-1-butanol, methyl-diethanolamine, ethyl amine ketone, tripropylene glycol methyl ether, dipropylene glycol methyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, 5-methyl-3-heptanone, dimethyl sulfoxide, dimethyl sulfone, dibenzyl ester, dimethyl adipate, dimethyl glutarate, dimethyl succinate, diisobutyl adipate, glyceryl carbonate, γ-butyrolactone, 1,3-benzenediol, trimethyl phosphate, polyoxymethylenes, 1-ethylpyrrolidin-2-one, 1-methyl-2-pyrrolidone, dipropylene glycol methyl ether acetate, 5-methyl-2-propan-2-ylcyclohexan-1-ol, dimethyl isosorbide, nonafluorobutyl ethyl ether (C 4 F 9 OC 2 H 5 ), 2-ethylhexyl acetate, ethyl benzoate, ethylene glycol diacetate, ethyl malonate, bis(2-butoxyethyl)ether, dibutyl sulfide, glyceryl triacetate, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol methyl ether acetate, propylene glycol methyl ether propionate, ethylene glycol butyl ether acetate, diethylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate, triethylene glycol monobutyl ether, polyethylene glycol dimethyl ether and ionic liquids.
The preferred compounds (C) are: propylene carbonate, dipropylene glycol n-butyl ether, tripropylene glycol methyl ether, tetraethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, dipropylene glycol methyl ether acetate and ethylene glycol diacetate, perfluoro-1,3-dimethylcyclohexane, perfluorooctane, perfluoro-1,3,5-trimethylcyclohexane, perfluorotributylamine, perfluoropolyether CF 3 [(OCF(CF 3 )CF 2 ) m (OCF 2 ) n ]OCF 3 (Galden HT 55, 70, 85, 90, 110).
The compounds (C) that are advantageously preferred are: dipropylene glycol n-butyl ether, 3-methoxy-3-methyl-1-butanol, dipropylene glycol methyl ether, dipropylene glycol propyl ether, dipropylene glycol methyl ether acetate, ethyl diglycol acetate, diethylene glycol butyl ether, 2-ethylhexyl acetate, tetraethylene glycol dimethyl ether, glyceryl triacetate, 2-butoxy-2-ethoxyethyl acetate, diethyl malonate, diethylene glycol diethyl ether, dimethyl glutarate, ethyl benzoate, triethylene glycol monobutyl ether, butyl sulfide and nonafluorobutyl ethyl ether.
Examples of particularly preferred compositions that may especially be mentioned include those comprising
difluoromethane, carbon dioxide and ethylene glycol diacetate, difluoroethane, carbon dioxide and ethylene glycol diacetate, 2,3,3,3-tetrafluoropropylene (HFO-1234yf), carbon dioxide and ethylene glycol diacetate.
The compositions according to the present invention are suitable for compression systems, for cooling applications (refrigeration system) or heating applications (heat-exchange pump) or in reversible machines, which produce cold for cooling or heat for heating.
With the compositions of the present invention, the presence of a liquid phase inside exchangers, comprising compound (C), and of a gas phase promotes the dissolution and evaporation phenomena according to the pressure levels. In the condenser, with an increase in pressure, the more volatile compounds, such as carbon dioxide, dissolve in the liquid phase and it is the heat of dissolution that adds to the heat of condensation. With the drop in pressure at the evaporator, the more volatile compounds are released from the liquid phase and absorb heat from the external medium. This absorbed heat adds to the heat of evaporation of the less volatile compounds (A) and thus increases the cooling power and the performance of the system. The compositions according to the present invention also have, according to the nature of the component (C), the advantage of functioning with a reduced amount of lubricants or in the absence of lubricant when they are used in compressors.
A subject of the present invention is also the use of the compositions described above as energy-transfer fluids and refrigerant fluids, in particular in the production of conditioned air.
The compositions described above are particularly suitable for use as refrigerant fluids in the air conditioning of vehicles and can partially or totally replace 1,1,1,2-tetrafluoroethane.
EXPERIMENTAL SECTION
A) Absorption of CO 2
64 q of carbon dioxide are introduced into a 320 ml autoclave equipped with a temperature sensor, a pressure sensor and a magnetic stirrer. The functionalized organic compound is then gradually introduced therein using a volume-displacement pump. The temperature of the autoclave is maintained at 40° C., using a thermostatically maintained bath, throughout the tests.
The pressure of the resulting mixture is given in Table 1.
TABLE 1
% of the functionalized organic compound
0
7
15
22
30
37
(vol/vol)
Pressure (bar)
Glyceryl carbonate
73.38
74.76
76.31
77.87
79.47
81.38
Dipropylene glycol n-butyl ether
72.6
67.7
63.25
59.49
56.32
53.15
Dipropylene glycol
70.56
70.55
70.39
70.16
70.09
69.75
3-Methoxy-3-methyl-1-butanol
72.58
67.71
64.71
62.79
59.92
57.29
Dipropylene glycol methyl ether
73.35
67.15
62.74
59.06
55.95
53.26
Dipropylene glycol propyl ether
72.53
68
63.96
60.5
57.54
54.79
Tripropylene glycol methyl ether
75.35
70.71
66.95
63.87
61.23
59.4
Tributyl borate
69.59
66.64
65.4
64.84
63
61.32
Dipropylene glycol methyl ether acetate
72.51
64.89
58.92
54.17
50.16
46.82
Ethyl diglycol acetate
72.04
65.79
60.77
56.3
52.28
49.24
Diethylene glycol dibutyl ether
71.61
66.96
64.86
62.19
59.03
56.41
2-Ethylhexyl acetate
72.72
66.36
61.49
57.51
54.24
51.36
Tetraethylene glycol dimethyl ether
71.79
65.64
62.66
58.17
54.32
50.99
Ethylene glycol diacetate
72.49
63.11
56.14
50.8
46.55
43.17
Glyceryl triacetate
72.44
67.14
61.42
56.69
52.58
49.24
2-Butoxy-2-ethoxyethyl acetate
71.79
66.25
61.57
57.09
53.2
49.87
Diethyl malonate
69.88
62.16
56.46
51.46
47.52
44.28
Diethylene glycol diethyl ether
71.82
64.57
58.47
53.65
49.53
46.03
Dimethyl glutarate
63.49
55.22
49.13
44.43
40.75
37.81
Ethyl benzoate
73.45
68.49
64.69
61.36
58.49
56.08
Triethylene glycol monobutyl ether
71.61
69.46
68.13
66.55
64.6
62.51
Butyl sulfide
72.45
68.48
66.05
63.45
61.16
59.2
Nonafluorobutyl ethyl ether
70.98
61.96
55.53
50.87
47.12
44.15
B) Thermodynamic Performance
Table 2 gives the performance of a composition comprising carbon dioxide (R744), ethylene glycol diacetate (EGDA) and optionally difluoromethane (R32). The thermodynamic properties used to calculate the performance may be summarized as follows:
The PSRK predictive model (T. Holderbaum and J. Gmehling, “A group contribution equation of state based on UNIFAC”, Fluid Phase Equilibrium, 1991, 70, 251-265) was used to calculate the “liquid-vapor” equilibria according to a symmetry approach and based on the group contribution methods. It is composed of an equation of state, an alpha function, a mixing rule and a UNIFAC solution model (A. Fredenslund, R. L. Jones and J. M. Prausnitz, “Group contribution estimation of activity coefficients in non-ideal liquid mixtures”, AlChE J., 1975, 21, 1086-1099).
The parameters of each of the constituents (carbon dioxide, difluoromethane and ethylene glycol diacetate) come from the Dortmund Data Bank (DDB) database (www.ddbst.de).
The binary systems and then the ternary systems were studied.
The PSRK UNIFAC parameters for the carbon dioxide and ethylene glycol diacetate binary are available in the Dortmund Data Bank (DDB) database (www.ddbst.de).
As regards the difluoromethane and carbon dioxide binary system, the available data were used (F. Rivollet, A. Chapoy, C. Coquelet and D. Richon, Fluid Phase Equilibrium, 218, 2004, 95-101, and R. A. Adams and F. P. Stein, J. Chem. Eng. Data, 16, (1971), 146-149).
As no literature data were available, measurements were taken for the difluoromethane and ethylene glycol diacetate binary system using the variable-volume synthetic technique (M. Meskel-Lesavre, D. Richon and H. Renon, Ind. Eng. Chem. Fundam., 20, 1981, 284-289).
Using the PSRK model and the parameters obtained from the binary systems, the bubble point corresponding to three ternary mixtures (carbon dioxide, difluoromethane and ethylene glycol diacetate) was predicted, and these predictions were validated with values measured using the variable-volume synthetic technique.
The equations of state developed for the ternary mixture are then used to determine the temperature-pressure curve and the performance in a theoretical compression cycle.
The conditions are:
external temperature 35° C. internal temperature 5° C. no loss of pressure in the exchangers isotropic compression cooling to 0° C. at the condenser outlet internal exchanger: cooling to 25° C. vapor titer at the evaporator outlet: 0.5 mol/mol
P evap denotes the evaporation pressure (kPa), P cond denotes the condensation pressure (kPa), T comp outlet denotes the temperature at the compressor outlet (° C.), COP denotes the coefficient of performance and CAP denotes the volumetric capacity (kJ/m 3 ).
TABLE 2
R744
EGDA
P evap
P cond
T comp outlet
CAP
weight %
weight %
(kPa)
(kPa)
(° C.)
COP
(kJ/m 3 )
60
40
2449
5895
97
2.20
8197.24
50
50
1908
5160
110
1.88
6327.27
40
60
1288
4382
133
1.49
4257.64
30
70
568
3529
202
0.92
1867.87
R744
EGDA
R32
P evap
P cond
T comp outlet
CAP
weight %
weight %
weight %
(kPa)
(kPa)
(° C.)
COP
(kJ/m 3 )
35
35
30
1392
4094
112.9
2.23
5757.66
30
30
40
1293
3788
110
2.42
5699.30
25
25
50
1214
3498
106
2.64
5687.62
20
20
60
1147
3220
101
2.90
5700.29
40
27
33
1640
4477
105
2.45
6847.71
35
23
42
1513
4162
104
2.60
6686.71
30
20
50
1395
3854
102.9
2.73
6488.47
25
17
58
1293
3556
100
2.90
6292.26
20
13
67
1211
3275
97
3.12
6185.94
10
7
83
1058
2721
90
3.64
5888.68
40
13
47
1746
4509
97
2.85
7914.97
35
12
53
1602
4200
98
2.93
7504.62
30
10
60
1478
3900
97
3.03
7189.41
25
8
67
1366
3609
95
3.17
6894.49
20
7
73
1258
3318
94
3.29
6589.8
|
The invention relates to compositions that can be used as refrigerants. More specifically, the invention relates to compositions having a very low contribution to the greenhouse effect, which can be used in the cooling and production of conditioned air. The GWP of the inventive compositions is preferably at most equal to 150.
| 2
|
[0001] The instant application is a continuation-in-part of U.S. application Ser. No. 13/832,519 which was filed on Mar. 15, 2013 and is still pending. That application is a continuation-in-part of U.S. application Ser. No. 13/748,406, which was filed Jan. 23, 2013 and is now abandoned. That application was, in turn, a continuation of U.S. application Ser. No. 12/924,352, filed Sep. 24, 2010 and issued on Feb. 26, 2013 as U.S. Pat. No. 8,382,870. The subject matter of each of the patent and the several applications is incorporated hereinto by reference in its entirety.
[0002] This disclosure relates to a self-cleaning air filter, and, in particular, a self-cleaning air filter for vehicles and motorized equipment.
BACKGROUND
[0003] Operating in dusty environments has long been a problem for equipment and vehicles. The respiration of dusty and contaminated air greatly hinders performance and can damage the vehicle or equipment's engines. Even though vehicles and equipment have filter elements that filter the inlet air flow, in extremely dusty environments, these filter elements quickly become caked with dust and debris, which retards and stops the air flow through the filter element to the engine. Consequently, these filter elements must be frequently cleaned to remove the deeply imbedded dust which penetrates into the filter element or the entire filter element must be replaced to ensure the proper operation of the equipment and vehicles. In extremely dusty environments, the demand of constantly cleaning and/or replacing filter elements comes at a significant cost of time and money.
[0004] A technique commonly referred to as “pulse jet” or “reverse pulse” self-cleaning has been used in industrial and large scale air filtration systems. Reverse pulse self-cleaning involves periodically releasing a quick burst (“pulse”) of compressed air into the filter element, which expands through the filter element in the opposite direction of the normal airflow through the filter element. The rapidly expanding compressed air pulse passing out of the filter element dislodges the dust cake collected on the outside of the filter element, as well as some dust which has penetrated into the element pleat. While effective for industrial and large scale air filtration systems, reverse pulse self-cleaning, heretofore, has been inoperable for small air filtration systems, such as those for vehicles and other types of motorized equipment. Reverse pulse self-cleaning works in industrial and large scale air filtration systems because of the sheer volume of the filter housing and the volume of the filter housings in relation to the volume of the filter elements.
[0005] In industrial and large scale applications, multiple arrays of filter elements are disposed within large volume filter housings. These filter housings are spacious enough that the compressed air pulse can propagate through the filter elements to effectively clean them before energy of the pulse dissipates within the filter housing and the pressure differential equalizes returning the system to its normal filtering operation.
[0006] In small scale applications, such as for vehicles and motorized equipment, where space is limited, the filter housings lack the volume in relation to the volume of the filter elements to make reverse pulse self-cleaning operable or effective. In such applications, a single filter element is typically disposed within the limited confines of the filter housing. The filter housings provide little volume around the filter element within which a compressed air pulse can expand and dissipate. Consequently, an expanding compressed air pulse almost instantly equalizes the pressure differential between the inside and outside of the filter element within the filter housing, which prematurely terminates the expansion of the pulse through the filter element. As a result, the effectiveness of the pulse jet self-cleaning action is lost or greatly reduced.
[0007] One issue with cleaning such filters with a compressed air pulse is that adequate air pressure must be exerted through the filter in order to remove or dislodge the dust cake collected on the outside of the filter element. It would therefore be advantageous to provide a pulse jet distribution arrangement which is capable of distributing the air pulse at an adequate pressure so as to dislodge the particulates from the exterior surface of the filter.
BRIEF SUMMARY
[0008] In one embodiment the present disclosure relates to an air cleaner assembly comprising a housing including an outer wall defining an air flow inlet, an air flow outlet and a hollow interior section. The housing outer wall includes a side wall. The housing is openable for service access to the hollow interior section. A serviceable filter cartridge is positioned in the housing hollow interior section. The filter cartridge is selectively removable from the air cleaner housing, with the filter cartridge comprising filter media surrounding an open central interior. A pulse jet distribution arrangement communicates with the hollow interior section of the housing. It includes a device configured to direct a pulse of compressed gas into the open central interior of the filter cartridge. An evacuation valve arrangement is mounted to receive ejected dust from the filter cartridge and is adapted to direct the received ejected dust out of the air cleaner housing. The valve arrangement comprises a frame, a blocking element mounted for reciprocation in relation to the frame and a biasing element for urging the blocking element into a closed position.
[0009] In another embodiment of the present disclosure, a self-cleaning air filter assembly which is connected to an associated compressed air source comprises a housing defining a chamber located therein and a hollow filter element disposed within the chamber such that an interior volume is defined within the filter element and an exterior volume is defined between the filter element and an interior wall of the housing. During a filtering cycle, a negative pressure differential between the interior volume and the exterior volume draws airflow inward through the filter element. During a self-cleaning cycle, a positive pressure differential between the interior volume and the exterior volume forces air flow outward through the filter element. A nozzle is configured to direct a pulse of compressed gas into the interior volume of the filter element. A valve in communication with the housing and connected to an associated compressed air source is provided for selectively releasing a pulse of compressed air into the nozzle whereby dust is dislodged from the exterior surface of the filter element into the housing chamber. A vent is mounted to the housing over an opening therein for venting the pulse of compressed air from the housing. The vent comprises a frame, a blocking element mounted for reciprocation in relation to the frame and a biasing element for urging the blocking element into a closed position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The drawings illustrate several embodiments of the present disclosure, in which:
[0011] FIG. 1 is a perspective view, partially broken away, of an air cleaner assembly including an air filter according to a first embodiment of the present disclosure;
[0012] FIG. 2 is an enlarged partial exploded view of the air filter of FIG. 1 showing a pressure relief valve and a portion of a housing;
[0013] FIG. 3 is an exploded perspective view of the pressure relief valve of FIG. 2 ;
[0014] FIG. 4 is an assembled side elevational view of the pressure relief valve of FIG. 3 ;
[0015] FIG. 5 is an end elevational view of the pressure relief valve of FIG. 4 ;
[0016] FIG. 6 is a side sectional view of the air filter of FIG. 1 shown during a normal filtering cycle;
[0017] FIG. 7 is a side sectional view of the air filter of FIG. 6 shown during a cleaning cycle;
[0018] FIG. 8 is a partial perspective view of an exemplary application of the air cleaner assembly of FIG. 1 used in a typical military style vehicle;
[0019] FIG. 9 is a simple schematic view of the air filtration system using the air cleaner assembly of FIG. 1 ;
[0020] FIG. 10 is a flow chart of a method for controlling a pulse valve employed for cleaning the air filter of FIG. 1 ;
[0021] FIG. 11 is a graph illustrating differential pressure across the air filter of FIG. 1 over the life of the air filter when the method of FIG. 10 is employed;
[0022] FIG. 12 is an enlarged view of a portion of the plateaued region of FIG. 11 ;
[0023] FIG. 13 is a graph representing a model relating the extent of clogging to pulse interval;
[0024] FIG. 14 is an end elevational view of another embodiment of air cleaner assembly according to the present disclosure;
[0025] FIG. 15 is a side elevational view in cross section of the air cleaner assembly of FIG. 14 along lines 15 - 15 ;
[0026] FIG. 16 is a front elevational view of a nozzle according to the prior art;
[0027] FIG. 17 is a cross sectional view of the nozzle of FIG. 16 along lines 17 - 17 ;
[0028] FIG. 18 is a side elevational view of a nozzle according to the present disclosure;
[0029] FIG. 19 is a front elevational view of the nozzle of FIG. 18 ;
[0030] FIG. 20 is an enlarged cross sectional view of the nozzle of FIG. 19 along line 20 - 20 ;
[0031] FIG. 21 is a graph illustrating inches of water restriction versus hours of operation comparing the prior art nozzle of FIGS. 16 and 17 and the nozzle illustrated in FIGS. 18-20 ;
[0032] FIG. 22 is a front elevational view of a nozzle according to still another embodiment of the present disclosure; and
[0033] FIG. 23 is a rear elevational view of a nozzle according to a further embodiment of the present disclosure.
DETAILED DESCRIPTION
[0034] FIGS. 1-13 illustrate an embodiment of an air cleaner assembly including a self-cleaning air filter according to the present disclosure, which is designated generally as reference numeral 10 . As shown, air filter 10 includes a tubular filter element 20 disposed within a cylindrical filter casing 30 . Filter element 20 is of conventional design and function having a tubular sidewall of pleated filter material, which collects dust and debris as air passes through. Filter element 20 is typically constructed of a blend of cellulose and synthetic fibers. Further, a synthetic fine fiber coating is typically applied to the surface of the media. Other constructions are, however, contemplated. For example, filter element 20 can be constructed of all synthetic fibers rather than conventional paper. Filter element 20 is axially centered within filter casing 30 . The tubular sidewall of filter element 20 is inset from the casing sidewalls defining an open space 13 around the outside of the filter element. The tubular sidewall also defines an open interior space 15 within filter element 20 . Filter casing 30 has an open end enclosed by a removable lid 38 . Lid 38 allows filter element 20 to be replaced as desired. Lid 38 is secured to casing 30 by connecting rod 39 , which extends axially through filter element 20 . Filter casing 30 includes an exterior surface 32 and an inlet port 34 , through which dust laden air 100 from the atmosphere enters one end (the “inlet end”) of air filter 10 and an outlet port 36 through which clean filtered air 104 exits the opposite end (the “outlet end”) of the air filter. As shown, inlet port 34 extends tangentially from the casing sidewall at the inlet end of filter casing 30 and an outlet port 36 that extends axially from the casing bottom 33 at the outlet end of casing 30 . Outlet port 36 allows for connection to the air intake and fuel induction system of a combustion engine by a hose, pipe or duct, although air filter 10 can be integrally mounted to the engine's air intake and fuel injection systems as desired.
[0035] A pulse valve 40 is mounted to the side of outlet port 36 and operably connected to a compressed air source 60 . Pulse valve 40 releases short blasts or pulses of compressed air from the compressed air source within filter element 20 , which facilitates the self-cleaning action of air filter 10 . In one embodiment, pulse valve 40 is a conventional solenoid type control valve where a solenoid (not shown) actuates a diaphragm (not shown) to open and close the valve. Pulse valve 40 is mounted to the side of outlet port 36 . An elbow 44 connects the output of pulse valve 40 to a nozzle head 46 , which is centered along the longitudinal axis of filter casing 30 . Nozzle head 46 includes a conical deflector 48 , which deflects the pulse of compressed air radially through filter element 20 . Pulse valve 40 is under the control of an electronic control module 42 , which actuates the solenoid to open and close the valve at predetermined intervals. Control module 42 is electrically powered by any available internal or external power source, but is generally powered using the electrical power source found in the equipment or vehicle. Control module 42 may include processing circuitry 37 , memory 39 and an I/O interface 41 for connection to other control system sensors and devices. The processing circuitry generally includes a suitable general purpose computer processing circuit, such as a microprocessor and its associated circuitry. The processing circuit is operable to carry out the operations attributed to it herein. Within the memory are various program instructions. The program instructions are executable by the processing circuit and/or any other components of the control module 42 as appropriate. If desired, one or more of the components of the control module 42 may be provided as a separate device, which may be remotely located from the other components of the control module.
[0036] In some embodiments, control module 42 controls pulse valve 40 based on flow through air filter 10 . In that regard, control module 42 receives measurements of parameters that can be used to measure air flow, or estimate air flow, through air filter 10 from one or more sensors 43 , 45 . Such parameters can include, for example, one or more of a) air pressure at inlet port 34 ; b) air pressure at the outlet port 36 ; c) air flow at the inlet port; and d) air flow at the outlet port. One or more sensors 43 , 45 can include, for example, one or more of air flow sensors (e.g., pitot tubes and/or anemometers) and air pressure sensors (e.g., vacuum transducers). Also, one or more sensors 43 , 45 can be used independently or concurrently. In one embodiment, a first vacuum transducer 43 measures air pressure at inlet port 34 and a second vacuum transducer 45 measures air pressure at outlet port 36 . Received parameter measurements are applied to a model relating the parameters to pulse rate to determine how to control pulse valve 40 . Pulse valve 40 is then controlled to pulse in accordance with the determination. One such model is described in connection with FIGS. 10-13 , discussed below.
[0037] Further, in some embodiments, control module 42 can interface with external systems and/or devices over SAE J1939/CAN OPEN protocols using I/O interface 41 . Using these protocols, control module 42 can be programmed and/or configured. For example, user-defined constants used in the model can be set using these protocols. As another example, the model can be configured and/or specified using these protocols.
[0038] Air filter 10 also includes a spring loaded pulse pressure vent (PPV) 50 , which vents the compressed air pulse from filter casing 30 during the self-cleaning cycle of air filter 10 . PPV 50 also acts as a vent for the dust removed during cleaning to be blown out of the housing. PPV 50 vents the over-pressure on the outside of filter element 20 from the compressed air pulse so that a pressure differential is maintained between the inside and outside of the filter element so that the cleaning action is maintained through the cleaning cycle. PPV 50 also acts as a vent for the dust removed during cleaning to be manually blown out of filter casing 30 . PPV 50 is mounted between the inlet and outlet ends of filter casing 30 within an opening 35 in the casing sidewall. PPV 50 includes an annular mounting pad 52 , which is securely seated within opening 35 of filter casing 30 . A plurality of spacers or posts 53 extending from mounting pad 52 suspend a cover plate 54 over opening 35 . A helical spring 56 biases a rigid diaphragm with a pliable seal 58 against mounting pad 52 to hold PPV 50 closed sealing filter casing 30 . Spring 56 is selected so that PPV 50 opens at a predetermined positive pressure within filter casing 30 .
[0039] During the normal filtering cycle ( FIG. 6 ), the operation of the combustion engine creates a negative pressure differential between the inside and outside of filter element 20 , which draws the airflow through air filter 10 . Dust laden air from the atmosphere enters air filter casing 30 through inlet port 34 . The dust laden air surrounds filter element 20 in area 13 and is drawn inward through the filter element 20 where dust and debris collect on the outside of the filter element. The now “filtered” air exits air filter 10 to the engine through outlet port 36 . As shown, PPV 50 is closed during the normal filtering cycle.
[0040] During the cleaning cycle ( FIG. 7 ), pulse valve 40 releases a short powerful blast of compressed air (the “compressed air pulse”) into filter element 20 , which dislodges dust and debris 102 from the filter element into area 13 thereby providing the self-cleaning action of air filter 10 . Nozzle head 46 directs the compressed air pulse onto the deflector 48 , which projects the compressed air pulse outward radially into the filter element. The compressed air pulse creates a high pressure wave that expands outward radially through filer element 20 as it moves along the length of filter element 20 from the outlet end to the inlet end. The high pressure wave created by the compressed air pulse briefly inverts the pressure differential between the inside and outside of filter element 20 and temporarily reverses the direction of air flow through filter element 20 thereby providing the cleaning action. In releasing the compressed air pulse, pulse valve 50 opens only for a brief duration generally 5-10 milliseconds. The cleaning cycle is maintained only as long as the positive pressure differential between the inside and outside of the filter element can be maintained. Consequently, the cleaning cycle lasts less than a few tenths of a second.
[0041] During the brief cleaning cycle, the over pressure of the compressed air pulse expanding through filter element 20 immediately opens PPV 50 . PPV 50 opens once the internal air pressure of filter casing 30 reaches its predetermined pressure. PPV 50 opens to vent the compressed air pulse to the atmosphere thereby maintaining the now positive pressure differential between the inside and the outside of filter element 20 . Venting the compressed air pulse to the atmosphere sustains the cleaning action for the entire duration of the pulse and allows the high pressure wave of the compressed air pulse to traverse the length of the filter element providing an efficient cleaning of the entire filter element. Without PPV 50 venting the compressed air pulse to the atmosphere, the pressure differential between the inside and outside of filter element 20 would quickly equalize within the confined space of filter casing 30 thereby interrupting the cleaning action provided by the compressed air pulse. Once the compressed air pulse has been vented from filter casing 30 , the positive pressure differential is lost and the vacuum draw from the outlet port 36 quickly reestablishes the negative pressure differential between the inside and outside of the filter element, whereby the air flow direction through air filter 10 reverts back and the normal filtering cycle is reestablished.
[0042] In certain embodiments, air filter 10 forms part of an integrated air filtration system in equipment or vehicles powered by any internal combustion engine that operates in environments with extremely high contents of dust, sand and other particulate in the atmosphere. By way of example only and for simplicity of illustration and explanation, FIGS. 8 and 9 illustrate the application of air filter 10 to an air filtration system of a military type vehicle 2 . In other embodiments, the air filtration system and the air filter may take other forms and be adapted for the desired application within the scope of this invention.
[0043] FIG. 8 depicts air filter 10 mounted to vehicle 2 outside of the engine compartment. The compressed air source (not shown in FIG. 8 ) is typically mounted to the vehicle undercarriage or within the engine compartment, which contains an engine 4 . It should be noted that in other applications, air filter 10 and the compressed air source may be located in any available space and suitable location on, in or outside of the vehicle or equipment as desired for the particular application.
[0044] FIG. 9 depicts a schematic of air filter 10 incorporated into an air filtration system of vehicle 2 . Pulse valve 40 is connected to compressed air source 60 by air line 72 . Another airline 74 supplies compressed air source 60 with filtered and dried air from outlet port 36 of air filter 10 thereby ensuring that the volume of compressed air supplied back to pulse valve 40 is contaminant and moisture free. A hose, pipe or duct 70 connects outlet port 36 of air filter 10 to the engine's air intake and fuel injection system 6 .
[0045] Compressed air source 60 supplies the volume of clean dry compressed air to air filter 10 from which the compressed air pulse is released within filter element 20 to facilitate the self-cleaning action. The necessary volume and pressure of the compressed air supplied from the compressed air source is determined by several factors, including, but not limited to the volume and configuration of air filter 10 , the type of filter element 20 , the volume and properties of dust within the inlet airflow, and the frequency of the air filter's cleaning cycle. Air filter 10 can be connected to any suitable and available compressed air source, whether specifically dedicated to supplying the air filter or one presently existing in the equipment or vehicle application that is available to supply the air filter. As shown, compressed air source 60 includes a compressor unit 62 , a storage tank 64 , a compressed air dryer 66 and moisture drain switch 68 . Compressed air source 60 may also include other ancillary components (not shown), such as, but not limited to, compressed air filters, water purge valves, pressure gages and switches, hoses, lines, clamps and fittings. Generally, the components which make up the compressed air source 60 are of conventional design well known in the art. Compressor unit 62 , storage tank 64 and other components of compressed air source 60 are selected so that the compressed air source supplies air filter 10 with the volume of clean, dry compressed air necessary for generating the required compressed air pulse within the air filter.
[0046] One skilled in the art will note that this invention enables the use of reverse pulse self-cleaning in small scale applications, such as for vehicles and motorized equipment. The pulse pressure vent compensates for the filter casing's small confined volume where the compressed air pulse is normally dissipated in large industrial systems by venting the compressed air pulse from the casing. The pulse pressure vent opens at a preset positive pressure so that the compressed air pulse vents to the atmosphere once it passes through the filter element. The pulse pressure vent maintains the positive pressure differential between the inside and outside of the filter element, which sustains the cleaning action during the cleaning cycle. Without the pulse pressure vent, the compressed air pulse would almost instantly expand within the confined volume of the filter casing and equalize the pressure differential between the inside and the outside of the filter element abruptly terminating the cleaning action before the pulse could clean the entire filter element. Venting the compressed air pulse through the pulse pressure vent allows the pressure wave of the pulse to travel the length of the filter element and the energy in the pulse to effectively dislodge dust from the filter element. The vent also provides an egress path from the filter casing for the dust and debris during the cleaning cycle. The pulse pressure vent can be readily adapted for filter housings of any size, configuration or capacity in a variety of vehicle, equipment and other applications. In addition, the pressure setting, size, configuration and location of the pulse pressure valve between the inlet and outlet ends of the filter casing is selected so that the compressed air pulse can be vented as the pulse travels the length of the filter element, thereby ensuring the entire area of the filter element will be cleaned.
[0047] FIGS. 10-13 illustrate a flowchart of a method 100 by which control module 42 controls pulse valve 40 to clean air filter 10 . Method 100 can be implemented as program instructions stored in memory 39 of control module 42 and executed by processing circuitry 37 of control module 42 . The flowchart spans from a beginning-of-life 102 of air filter 10 to an end-of-life 104 of the air filter. Beginning-of-life 102 corresponds to the point in the life cycle of air filter 10 when the air filter has not been used or is clean. End-of-life 104 corresponds to the point in the life cycle of air filter 10 when the air filter is no longer performing according to specification or is otherwise unsuitable for continued air filtering.
[0048] Referring to FIG. 10 , at beginning-of-life 102 of air filter 10 , a current differential air pressure ΔP ACT across inlet port 34 and outlet port 36 is measured 106 during normal operation of the vehicle. In one embodiment, to measure differential pressure ΔP ACT , an air pressure IP ACT at inlet port 34 during normal operation of the vehicle is measured using first vacuum transducer 43 and an air pressure OP ACT at outlet port 36 during normal operation of the vehicle is measured using second vacuum transducer 45 . Thereafter, the difference between the two pressures is calculated to determine differential pressure ΔP ACT =OP ACT −IP ACT . In another embodiment, differential pressure ΔP ACT is estimated from pressure IP ACT .
[0049] To estimate differential pressure ΔP ACT , pressure IP ACT is measured using first vacuum transducer 43 . Further, an air pressure OP HI at outlet port 36 and an air pressure IP HI at inlet port 34 are determined when the vehicle engine is at full load or high idle and air filter 10 is new and clean. Thereafter, the ratio between pressure IP ACT and pressure IP HI is determined:
[0000]
IP
ACT
IP
HI
.
[0000] The ratio is applied to scale a differential air pressure ΔP HI =OP HI −IP HI across air filter 10 when the vehicle engine is at full load or high idle and air filter 10 is new and clean is determined:
[0000]
Δ
P
HI
IP
ACT
IP
HI
.
[0000] This scaled differential pressure corresponds to an estimate of differential pressure ΔP ACT . Pressure IP m , pressure OP HI and differential pressure ΔP HI can be determined at beginning-of-life 102 of air filter 10 or determined from another air filter of the same type as air filter 10 at the beginning-of-life of the other air filter.
[0050] After measuring differential pressure ΔP ACT , a determination 108 is made as to whether differential pressure ΔP ACT exceeds a threshold T. If differential pressure ΔP ACT fails to exceed threshold T, differential pressure ΔP ACT is measured 106 again and determination 108 is repeated. Optionally, the re-measurement can be delayed by a predetermined amount of time (e.g., one minute). Until threshold T is exceeded, pulse valve 40 is disabled and cleaning is disabled.
[0051] Threshold T is typically set at a level that allows an optimal amount of dust to build up in air filter 10 before cleaning of the air filter can begin. This recognizes that, generally, in dust collection and self-cleaning, some amount of dust on air filter 10 is desirable for maximum cleaning efficiency. Typically, the optimal amount of dust increases pressure differential ΔP HI by 2-4 inches water column. Alternatively, threshold T can be set to allow more or less than an optimal amount of dust to build up, or to allow cleaning to begin immediately.
[0052] While not necessary, threshold T is typically based off pressure differential ΔP HI and a caking factor CA F . Caking factor CA F is a constant entered into the control module 42 that specifies an air pressure increase above pressure differential ΔP HI when the vehicle engine is at full load or high idle and air filter 10 is new and clean. Caking factor CA F is typically set to achieve the optimum amount of dust buildup for filtration. Threshold T at full load or high idle is the summation of differential pressure ΔP HI and caking factor CA F . However, when not at full load or high idle, differential pressure ΔP HI and caking factor CA F need to be scaled to determine threshold
[0000]
T
=
(
(
IP
ACT
IP
HI
)
Δ
P
HI
)
+
(
(
IP
ACT
IP
HI
)
CA
F
)
.
[0000] As should be appreciated, the scaling is done as described above to estimate differential pressure ΔP ACT .
[0053] With reference to FIG. 11 , an example graphical representation of pressure differential ΔP ACT over the life of air filter 10 is illustrated. The vertical axis corresponds to pressure differential ΔP ACT (e.g., in inches water column) and the horizontal axis corresponds to the life of air filter 10 (e.g., in hours). As can be seen, pressure differential ΔP ACT gradually increases before plateauing. The level at which pressure differential ΔP ACT stops gradually increasing is defined by threshold T.
[0054] Once differential pressure ΔP ACT exceeds threshold T, an optimal differential air pressure ΔP OPT across air filter 10 at the current load is calculated 110 . In some embodiments, differential pressure ΔP OPT is the same as threshold T. In that regard, differential pressure ΔP OPT is typically equal to
[0000]
(
(
IP
ACT
IP
HI
)
Δ
P
HI
)
+
(
(
IP
ACT
IP
HI
)
CA
F
)
.
[0000] As should be appreciated, differential pressure ΔP OPT varies as engine load changes (i.e., as the revolutions per minute (RPM) of the engine changes). For example, a reduction in RPM results in a reduction of differential pressure ΔP OPT . After calculating differential pressure ΔP OPT , the difference between differential pressure ΔP ACT and differential pressure ΔP OPT is calculated as a clogging factor CL F =ΔP ACT −ΔP OPT , as illustrated in FIG. 12 . FIG. 12 shows an enlarged view of a portion of the plateaued region of FIG. 11 . The vertical axis corresponds to pressure differential ΔP ACT and the horizontal axis corresponds to the life of air filter 10 .
[0055] The foregoing calculated clogging factor CL F by down scaling differential pressure ΔP HI and clogging factor CA F . In some embodiments, clogging factor CL F can instead be calculated by upscaling differential pressure ΔP ACT as follows:
[0000]
CL
F
=
(
IP
HI
IP
ACT
)
Δ
P
ACT
-
Δ
P
HI
-
CA
F
.
[0056] Clogging factor CL F is input into a model relating clogging factor CL F to the pulse interval for cleaning pulses to calculate the current pulse interval. The model includes upper and lower bounds on the pulse interval, such as two minutes and one hour, respectively. Further, the model can include upper and lower bounds on clogging factor CL F , which correspond to the lower and upper bounds on the interval, respectively. Typically, as clogging factor CL F increases, the pulse interval decreases, and vice versa. If clogging factor CL F is less than its lower bound, the pulse interval will be the greatest allowed pulse interval (e.g., one hour). Similarly, if clogging factor CL F is greater than its upper bound, the pulse interval will be the smallest allowed pulse interval (e.g., two minutes). The model is suitably defined by a user of control module 42 , for example, by defining lower and upper bounds for clogging factor CL F and the pulse interval.
[0057] FIG. 13 illustrates a linear model relating clogging factor CL F to the pulse interval for cleaning pulses. The vertical axis corresponds to clogging factor CL F , and the horizontal axis corresponds to the pulse interval spacing in time units. As illustrated, the pulse interval increases linearly as clogging factor CL F increases and decreases linearly as clogging factor CL F decreases. In some embodiments, the model may be exponential.
[0058] In some embodiments, the model adds a scaling factor to increase the pulse interval for low engine loads (e.g., low engine RPM). Namely, flow rate through air filter 10 decreases as engine load decreases. Through testing, it has been found that the optimal pulse interval for low engine loads does not necessarily correspond to the optimal pulse interval for higher engine loads. The pulse intervals at low engine loads are too high. Hence, a scaling factor can be added for lower engine loads to decrease the pulse interval. For example, the scaling factor can increasingly decrease the interval as engine load decreases.
[0059] After calculating the pulse interval, pulse valve 40 is pulsed 112 according to the pulse interval to clean air filter 10 . A determination 114 is then made as to whether air filter 10 has reached end-of-life 104 . So long as air filter 10 has not reached end-of-life 104 , differential pressure ΔP ACT is measured 116 again and the foregoing is repeated starting from calculating 110 differential pressure ΔP OCT . Optionally, the re-measurement can be delayed by a predetermined amount of time (e.g., one minute). If air filter 10 has reached end-of-life 104 , a user of control module 42 can be notified by, for example, one or more of a light, audible alarm, display readout, or by interface to the vehicle computer and a display location of the vehicle manufacturer's choice.
[0060] End-of-life 104 can be determined in any number of ways. For example, end-of-life 104 can be a predetermined time duration from beginning-of-life 102 . As another example, end-of-life 104 can be the time point at which differential pressure ΔP ACT is no longer controllable at the maximum pulse frequency (i.e., lowest pulse interval). This can be determined through historical analysis of previous pulse intervals used with pulse valve 40 . If the smallest pulse interval was previously used with pulse valve 40 , and a predetermined amount of time has elapsed, with no improvement in clogging factor CL F , differential pressure ΔP ACT is no longer controllable. FIG. 11 illustrates this uncontrolled differential pressure P ACT can be monitored for signs that end-of-life 104 is reached.
[0061] In view of the foregoing, differential pressure ΔP ACT is actively controlled by changing the pulse interval to maintain differential pressure ΔP ACT as close to differential pressure ΔP OPT as possible. As clogging factor CL F increases, the pulse interval of air valve 40 decreases. Eventually, clogging factor CL F should start to fall again, whether this is due to the increased pulse frequency or simply an environment with light dust loading. The pulse frequency will then decrease until clogging factor CL F increases again. In some instances, clogging factor CL F continues to increase due to an extremely dusty environment or air filter 10 reaching end-of-life 104 .
[0062] Further, in view of the foregoing, method 100 estimates flow or a percentage of full flow without utilizing a flow sensor. It is done with independent vacuum transducers. Advantageously, the vacuum transducers provide simplicity, reliability, and cost reduction as compared to approaches which directly measure air flow with an anemometer or a pitot tube. However, it is to be appreciated that direct measurements of air flow can be employed with the approach described herein. Flow can be directly measured using, for example, a pitot tube or an anemometer
[0063] When employing direct measurements of flow with method 100 , differential pressure is replaced with the direct measurement of flow at inlet port 34 . Further, the above described ratios are replaced with the ratio of flow F ACT during normal operation of the vehicle and flow F HI when the vehicle engine is at full load or high idle and air filter 10 is new and clean:
[0000]
F
ACT
F
HI
.
[0000] To illustrate, optimal flow F OPT can be calculated as
[0000]
F
ACT
+
(
(
F
ACT
F
HI
)
CA
F
)
,
[0000] and clogging factor CL F can be calculated as F ACT −F OPT .
[0064] With reference now to FIGS. 14 and 15 , another embodiment of a cleaner assembly includes a filter 120 which may be tubular or cylindrical. In other words, it has a hollow interior. The filter is disposed within a cylindrical housing 130 . The housing includes an inlet port 134 which may be located adjacent one end, the distal end, of the housing and an outlet port 136 which may be located adjacent another end, the proximal end, of the housing. The housing itself is cylindrical in nature with a hollow interior. The distal end of the housing 130 is closed by a lid 138 . A connecting rod 139 extends centrally in the housing and mounts at one end to the lid 138 . Another end of the connecting rod 139 mounts to a nozzle 150 .
[0065] With reference also now to FIGS. 18-20 , the nozzle comprises a housing 152 including an inlet end 154 which is open and an outlet end 156 which is generally closed so as to define a hollow interior 158 . The interior includes a threaded section 160 which accommodates a threaded end of a conduit 161 ( FIG. 15 ). The nozzle comprises a longitudinal axis 162 and a central opening 164 through the outlet end 156 which is aligned with the longitudinal axis 162 . Also provided are at least two side openings 168 . As best seen in FIG. 19 , the side openings 168 can be generally arcuate in nature, such that each of them extends at least 45 degrees around the circumference of a circle defined in the outlet end 156 encircling the central opening 164 . In the embodiment shown, three such openings 168 are provided.
[0066] As is best seen in FIG. 20 , the side openings extend at an angle α of approximately 22½ degrees from the longitudinal axis 162 of the nozzle. It should be apparent from FIG. 20 that the hollow interior 158 includes an enlarged diameter section 172 located immediately adjacent to inlet ends of the side openings 168 and that the inlet ends comprise radiused inlets 174 . These allow for a relatively smooth flow of air through the nozzle. The outlet ends of the side openings 168 can be sharp and not radiused as shown in this embodiment. However, no air flows through the central opening 64 . Rather, it is threaded as at 176 in order to accommodate a threaded end of the connecting rod 139 . As is apparent from FIG. 15 , the connecting rod mounts at one end to the nozzle 150 and at the other end to the filter 120 to retain it in place.
[0067] With continued reference to FIG. 15 , the housing 130 also includes a pulse pressure vent assembly 180 . This comprises a housing opening 182 which is surrounded by a plurality of posts or standoffs 186 to which is mounted a cover plate or stop 190 . Disposed between the opening 182 and the cover plate 190 is a biasing member 192 , such as a spring. The spring biases a blocking member 196 or diaphragm that selectively seals the housing opening 182 . As is evident from FIG. 14 , in one embodiment, the cylindrical housing 130 can include three such pressure vent assemblies 180 . These can be located equiangularly around the periphery of the housing 130 . However, other configurations, such as two or four vents, are also possible. Further, the angular locations of the vents does not need to be symmetrical.
[0068] It has been found that the nozzle 150 illustrated in FIGS. 18-20 is advantageous in relation to a prior art nozzle 210 of the type which is illustrated in FIGS. 16 and 17 . The prior art nozzle 210 includes a housing 212 with an inlet end 214 and an outlet end 216 so as to define a hollow interior 218 . The hollow interior can include a threaded section 220 . The nozzle includes a longitudinal axis 222 along which lies a central opening 224 . The central opening is threaded as at 226 . Also provided are a plurality of side openings 228 , each of which is generally circular as best shown in FIG. 16 . In the prior art, six or eight such side openings 228 can be provided in the housing 212 . The side openings 228 are also threaded as at 230 . The threading is believed to improve air flow through the side openings. It should be apparent from FIG. 17 that the side openings are provided on a radiused face 236 of the nozzle.
[0069] With reference now to FIG. 21 , through testing, it has been found that a prior art nozzle similar to the one illustrated in FIGS. 16 and 17 is disadvantageous from the standpoint that when employed in the air cleaner assembly illustrated in, e.g., FIGS. 14 and 15 , the nozzle does not clean the filter sufficiently so as to retard or minimize a restriction of the filter, i.e., a reduction in the filtration capability of the filter, by a buildup of dirt and dust on the exterior periphery of the filter. Put another way, the restriction encountered during filtration, even after pulse cleaning the filter using the prior art nozzle is significantly larger than is the restriction encountered when employing the nozzle of FIGS. 18-20 and when using the same pulse duration and pressure of air in the same filter housing to clean the identical filter. The prior art nozzle tested had six threaded side holes which were at an angle of about 22½ degrees to a longitudinal axis of the nozzle. This nozzle, while it had good dispersion, did not release enough pressurized air to adequately clean the filter. The restriction of the filter, namely, dirt and dust build up on the exterior periphery of the filter, was such that it made it difficult for the filter to allow enough air flow through it to supply the internal combustion engine with an adequate amount of air. Such restriction becomes significant as early as 10 hours into the operation of the air cleaner assembly and is very pronounced at 20 hours or more. In contrast to the almost exponential increase in the restriction of the filter attempted to be cleaned with the prior art nozzle of FIGS. 16 and 17 , the nozzle of FIGS. 18-20 is capable of repeatedly cleaning the same filter so that the restriction of the filter does not increase significantly as the hours of operation of the air cleaner assembly passes 60, 80 or even 100 hours.
[0070] Pulse volume testing performed on the prior art nozzle indicates that the relative energy released through this nozzle is not acceptable to effectively dislodge the dust from the filter element. Therefore, it was determined that increasing the open area of the nozzle was called for and, hence, arcuate shaped openings in the nozzle were developed. The angle of trajectory and the coverage area of the nozzle relative to the filter element appears to be advantageous at 22½ degrees in relation to the longitudinal axis of the nozzle.
[0071] It has been found that the prior art nozzle did not allow an adequate amount of pressurized air to flow at a high enough pressure to fully clean the filter. Although the dispersion of pressurized air to the interior periphery of the filter was adequate, the air pressure was inadequate. In order to increase the energy of the air exiting the nozzle so as to effectively pulse clean the cylindrical filter, arcuate apertures have been employed. It has been found that the lesser the number of openings, the better. Although testing data may be needed to confirm this, it would appear that the maximum number of openings which could be employed, while still providing air at a high enough pressure, would be four. Such a nozzle may prove useful on a large diameter cylindrical filter element that is very long. On the other hand, perhaps just two longer arcuate openings in the nozzle would be advantageous, because they would allow for slightly more open area at the outlet end of the nozzle. It is also believed that larger nozzles may allow for an increase in angular slot length, although it is believed that reducing the number of slots or arcuate openings would probably have a greater effect in increasing the throughput of air through the nozzle.
[0072] If four arcuate openings were employed, each opening could be on the order of 45 degrees. Thus, the four openings together would constitute a minimum of 180 degrees around the circumference of a circle centered on the openings. Four slots would decrease the open area percentage at the outlet end of the nozzle but would increase air velocity. Thus, a design with four slots might work better on filter elements which are longer. The nozzle illustrated in, e.g., FIG. 19 comprises three 60 degree openings, again amounting to a minimum of 180 degrees around the circumference of a circle.
[0073] In the embodiment of the nozzle shown in FIGS. 18-20 , the slot entrance area of each nozzle is 0.108 inches squared. However, the exit area is 0.161 inches squared. This occurs because the size of the aperture in the nozzle increases from the entrance end to the exit end, thus, increasing the area of the opening and the measured width thereof.
[0074] Pulse cleaning of a filter is effective due to several factors. These include the pressure of the air, the direction and angle of dispersion, the volume of the air and the velocity of the air. In the chart of FIG. 21 , it can be seen that the nozzle of FIGS. 18-20 adequately performs with the specific size and shape of the filter element illustrated at FIG. 15 . That filter has a length of about 12.75 inches, an internal diameter of about 5.1 inches and an external diameter of about 9.1 inches, and hence a thickness of 2 inches. The filtration material of the filter used was Hollingsworth and Vose number FA6900NWFR. A planar filtration material was employed in a pleated filter arrangement. The results shown in FIG. 21 will change if a different size or shape is provided for the filter element and also if its thickness is changed or if the filtration material used is different, even if the air pressure and nozzle shape are kept constant.
[0075] In another embodiment of the present disclosure, as illustrated in FIG. 22 , a nozzle 250 could be provided with a plurality of arcuate openings 252 (three in number in this embodiment), wherein each opening extends at an angle β of approximately 84 degrees at an outlet end 256 of the nozzle. It is believed that the larger sized openings 252 are advantageous from the perspective that they will allow an increased amount of pressurized air to flow at the outlet end of the nozzle. In this embodiment, therefore, about 252 degrees of open area are provided at the outlet end of the nozzle with the metal material of the nozzle at that surface constituting only 108 degrees of the circumference of a circle centered on the nozzle openings 252 .
[0076] With reference now to FIG. 23 , in accordance with still another embodiment of the present disclosure, a nozzle 270 can include a central opening 274 and a set of side openings 278 , each having a filleted entrance as at 280 , such that the openings lie adjacent to each other. In this embodiment, the peripheral openings almost touch each other, thereby providing the nozzle 270 with a yet further enlarged set of openings to more easily allow a flow of pressurized air when pulse cleaning a cylindrical filter. It appears that maintaining nozzle integrity is not an issue for concern with regard to the sizes of the arcuate slots for the nozzle disclosed herein. Rather, geometry is the limiting factor. The slots begin at a smaller diameter and gradually increase toward the exit of the nozzle. Thus, the inlet side of each slot in the nozzle can only have so much open area so that the filleted entrance is not compromised. The maximum size is illustrated in FIG. 23 .
[0077] As to the diameter of the nozzle which can be used in an air cleaning environment, the nozzle diameter is going to control the cleaning area which needs to increase if the filter element gets larger. Since the nozzle is located in this embodiment in the outlet area of the air filter, it does block some of the outlet's flow area (see FIG. 15 ). Thus, the maximum diameter of the nozzle must be small enough that it does not cause significant restriction in the air outlet for the air which has been cleaned by the filter. In order to minimize such a restriction on nozzle diameter, one could increase the diameter of the outlet tube. However, the outlet tube diameter is often dictated by the size of the engine, meaning that this option may be limited. One way of addressing that issue would be to make the outlet tube have a larger diameter in the area where the nozzle lies and, downstream from the nozzle, taper down the diameter of the outlet tube to an appropriate size to match the size necessary for the engine in question.
[0078] At this point, applicants have not performed much experimental testing to better understand the effect of changing the number of openings in the nozzle or changing their size. However, it has been determined that to increase the energy conveyed by the pulsed air, arcuate openings of a minimum size are necessary in order that the cylindrical filter be adequately cleaned during pulse cleaning so that dirt built up on the exterior surface of the filter does not result in an unwanted increase in the restriction to flow through the filter during filtration after ten or twenty hours of use.
[0079] The disclosure has been described with reference to several embodiments. Obviously, modifications and alterations will occur to others upon a reading and understanding of this disclosure. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims and the equivalents thereof.
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An air cleaner assembly includes a housing having an outer wall defining an air flow inlet, an air flow outlet and a hollow interior section. The housing is openable for service access to the interior section. A serviceable and selectively removable filter cartridge is positioned in the housing. The filter cartridge includes filter media surrounding an open central interior. A pulse jet distribution arrangement communicates with the interior of the housing and includes a device configured to direct a pulse of compressed gas into the interior of the filter cartridge. An evacuation valve arrangement is mounted to the housing to receive ejected dust from the filter cartridge and direct the received ejected dust out of the housing. The valve arrangement includes a frame, a blocking element mounted for reciprocation in relation to the frame and a biasing element for urging the blocking element into a closed position.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a liquid tank for holding a liquid used for recording. More particularly, the invention relates to a liquid tank for ink-jet recording which can smoothly and sufficiently supply an ink-jet head with ink when it is mounted on the ink-jet head.
[0003] 2. Description of the Related Art
[0004] Conventionally, a liquid tank for accommodating a liquid used for recording (hereinafter termed an “ink tank” or an “ink cartridge”) is integrated with an ink-jet head. When ink within the cartridge becomes incapable of being discharged, the ink tank is, in most cases, disposed together with the head. The amount of ink remaining within the cartridge in this stage depends on the ink holding capability of a sponge, serving as a negative pressure producing material, accommodated in substantially the entire space within the cartridge, and is relatively large even if it is intended to improve the cartridge.
[0005] An ink tank or an ink receptacle of this kind is disclosed in Japanese Patent Laid-Open Application (Kokai) No. 63-87242 (1988). This ink receptacle incorporates a foamed material, and constitutes a cartridge integrated with an ink-jet head including a plurality of ink discharging orifices. In this ink receptacle, by storing ink in a porous medium, such as foamed polyurethane, serving as the foamed material, a negative pressure is generated due to the capillary force of foams, and the ink is held to prevent leakage of the ink from the ink receptacle.
[0006] However, since it is necessary to load the foamed material in substantially the entire space of the unique ink receptacle, the amount of filled ink is restricted, and the amount of ink remaining in the foamed material without being used is relatively large. Accordingly, the use of the foamed material becomes inefficient due to the amount of ink retained by the foamed material. There exist also the problems that it is difficult to detect the amount of remaining ink, and that the negative pressure gradually changes while the ink is being consumed, so that it is difficult to maintain a substantially constant negative pressure for a long period.
[0007] In contrast to this configuration, an ink cartridge which holds substantially only ink is disclosed in Japanese Patent Laid-Open Application (Kokai) No. 2-522 (1990). In this ink cartridge which is integrated with an ink-jet head, a small porous member is disposed between a primary ink tank for holding only a large amount of ink which is provided at an upper portion, and the ink-jet head provided at a lower portion. It is claimed that this ink cartridge can improve the efficiency of use of ink because the porous member is disposed only in an ink channel instead of being incorporated within the ink tank. It is also claimed that, by providing a secondary ink tank, serving as a space capable of holding ink, at a side of the porous member, ink drawn from the primary ink tank due to the expansion of the air within the primary tank caused by temperature rise (a decrease in the pressure) is stored in the secondary ink tank, so that the negative pressure for the print head during printing can be maintained substantially constant.
[0008] However, in this ink cartridge, since excessive ink is impregnated in the porous member from the primary ink tank for holding only a large amount of ink which is provided at the upper portion, a negative pressure is hardly generated in the porous member. Hence, there is the possibility that ink leaks from an orifice of the ink-jet head by a slight jolt. Hence, this ink cartridge is not suitable for practical use. If an exchangeable ink cartridge which is mounted on an ink print head is adopted in this configuration, ink leaks because of the above-described state of the porous member. Hence, this cartridge is not practially for use.
[0009] An ink cartridge, in which ink is sealed within a bag, and a spring for maintaining the negative pressure of the bag constant is provided, is also known. However, this configuration increases the production cost, and it is difficult to achieve mass production of such ink cartridges while maintaining the performance of the spring.
[0010] As described above, none of conventional (non-contact-printing) ink cartridges for ink-jet printing are inexpensive and have a rational technical level.
[0011] The assignee of the present application has proposed, for example, in U.S. Pat. Nos. 5,509,140 and 5,619,238, ink receptacles suitable for the technical field of ink-jet printing which satisfy the conditions of excellent supply of ink corresponding to the amount of ink discharged from a head during printing, a high efficiency of use of ink, and occurrence of no problems, such as leakage of ink from a discharging port, and the like, while printing is not performed. Such an ink receptacle includes a first chamber incoporating a negative pressure producing material and including an air communication port for obtaining communication with atmospheric air, and a second chamber for directly accommodating ink to be supplied to the first chamber in a substantially closed state although communicating with the first chamber only via a communication port. The communicating port is provided at a part of a partition wall for separating the first chamber from the second chamber.
[0012] In this ink receptacle, ink is consumed when the ink is supplied to the ink-jet head side via an ink outlet provided in the first chamber. At the moment when a part of the liquid surface of the ink in the first chamber reaches the upper portion of the communication port, the inside of the second chamber which has been in a substantially closed state starts to communicate with atmospheric air to supply an air bubble into the second chamber. At the same time, the ink in the second chamber is supplied to the first chamber via the communication port. Mutual supply of the gas (an air bubble) and the liquid (ink) at the communication port will be hereinafter termed gas-liquid exchange. In the receptacle having this configuration, gas-liquid exchange is performed, so that the ink within the second chamber is supplied and consumed.
[0013] Since this configuration has a tank structure which can maintain the negative pressure substantially constant (at least while the ink within the second chamber is being consumed) during most of the time from the start of use to the end of use of the ink-jet cartridge, it is possible to provide a cartridge for ink-jet recording which can be used even for high-speed printing.
[0014] In the ink cartridge having the above-described configuration, the size of the air bubble generated during gas-liquid exchange while the ink is being consumed greatly increases depending on the shape of the opening of the communication port, and the surface tension and the viscosity of the air bubble which depend on the type, the components and the like of the accommodated ink, and the grown air bubble may remain in the communication port. In such a case, there is the possibility that gas-liquid exchange via the communication port is hindered from stopping the supply of ink from the first chamber to the second chamber.
[0015] However, since the shape and the size of the opening of the communication port are limited by various factors, such as the external shape of the cartridge, and the like, there is little room for changing the shape and the size. Furthermore, characteristics, such as the surface tension of ink, and the like, are determined by the use of the cartridge, and the like.
SUMMARY OF THE INVENTION
[0016] It is an object of the present invention to provide a liquid tank configured so that gas-liquid exchange can be safely and assuredly achieved and ink can be stably supplied even if a grown air bubble remains in a communication port.
[0017] It is another object of the present invention to provide a structure of a liquid tank which allows movement of an air bubble generated by gas-liquid exchange to a second chamber for storing ink without remaining in a communication port.
[0018] Surface tension is one of reasons why an air bubble remains in the communication port when gas-liquid exchange is effected. When an air bubble formed during gas-liquid exchange adheres to the inner wall of a receptacle constituting an ink tank, a contact angle (between the liquid (ink) and the surface of the wall) determined by the surface tension is present on a contact border line between the air bubble and the wall. In order to effect gas-liquid exchange, it is necessary to peel the air bubble from the wall with a force exceeding the contact angle.
[0019] In the present invention, in order to reduce the peeling force by reducing the contact area of the air bubble, projections or grooves are formed at the communication port. At that time, if the air bubble enters a projection or a groove formed at the communication port, the border line of the contact surface between the air bubble and the wall further increases. That is, when the width and the height (depth) of the projection or the groove are substantially the same as the diameter of the air bubble generated by gas-liquid exchange, the air bubble enters a groove formed between the adjacent projections or in one of the grooves and it is difficult to extract the air bubble. Accordingly, it is necessary to make the projections or the grooves formed at the communication port narrower than the diameter of the air bubble formed during gas-liquid exchange in order to prevent the air bubble from entering the above-described groove. If the depth of the groove is too small, there is the possibility that the air bubble enters the groove. Hence, the depth is preferably close to the value of the diameter of the air bubble.
[0020] There is no particular limitation in the shape of the opening constituting the communication port, provided that the contact surface between the air bubble and the wall does not increase by providing the projections or the grooves.
[0021] According to one aspect, the present invention which achieves these objectives relates to a liquid tank including a first chamber which incorporates a liquid and a negative pressure producing material and which includes an air communication port for obtaining communication with atmospheric air, and a supply port serving as an ink outlet, and a second chamber for directly accommodating the liquid to be supplied to the first chamber in a substantially closed state although communicating with the first chamber only via a communication port which is provided at a position separated from the air communication port. The communication port is formed between a partition wall for separating the first chamber from the second chamber, and a chamber inner surface which is a border region between the first chamber and the second chamber where an end portion of the partition wall contacts if the partition wall is extended. A liquid transfer channel which is longer than a length of the partition wall in a direction of the thickness of the partition wall is provided along the chamber inner surface facing the communication port.
[0022] In this configuration, even if an air bubble remains at an upper portion of the communication port, the liquid in the second chamber can be assuredly and sufficiently supplied to the first chamber by being transferred along the liquid transfer channel provided at a lower portion of the communication port. Even if an air bubble remaining in the communication port regulates the interface of the liquid within the second chamber and separates the interface of the liquid from the communication port, by making the liquid transfer channel long so as to contact the interface of the liquid, the liquid can be assuredly supplied to the first chamber. It is possible to thus provide an air guiding channel at an upper portion of the communication port and to provide the liquid transfer channel at a lower portion of the communication port by utilizing the surface tension of the air bubble.
[0023] From such a viewpoint, the liquid transfer channel is preferably disposed so as to be longer to the second chamber side than to the first chamber side.
[0024] The liquid transfer channel is preferably decreasingly sloped toward the negative pressure producing material in the first chamber. The application or release of a partial pressing force for the negative pressure producing material must be avoided as much as possible in consideration of influence on the distribution of the negative pressure within the negative pressure producing material. If it cannot be avoided, the amount of changes in the pressing force must be minimized. For that purpose, it is necessary to mitigate the influence of the partial negative pressure whether the liquid transfer channel is concave or convex.
[0025] The liquid transfer channel may include at least one projection projected from the chamber inner surface of the communication port or at least one recess formed in the chamber inner surface of the communication port.
[0026] A plurality of projections or recesses may be formed in the liquid transfer channel.
[0027] The plurality of projections or recesses of the liquid transfer channel may be extended in directions of the thickness of the partition wall.
[0028] The recesses as a liquid guiding channel may be provided between the plurality of projections of the liquid transfer channel.
[0029] The supply port of the first chamber may face the air communication port, and may be provided at a wall portion of the first chamber where the liquid transfer channel at the communication port is formed.
[0030] The foregoing and other objects, advantages and features of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] [0031]FIG. 1 is a cross-sectional view illustrating the configuration of an ink cartridge, serving as an ink tank, according to a first embodiment of the present invention;
[0032] FIGS. 2 ( a ) and 2 ( b ) are diagrams illustrating the configuration of a surrounding structure of a communication port in the first embodiment: FIG. 2( a ) is a cross-sectional view of a principal portion of the communication port, and FIG. 2( b ) is a cross-sectional view taken along line b-b shown in FIG. 2( a );
[0033] FIGS. 3 ( a ) and 3 ( b ) are diagrams illustrating the configuration of a surrounding structure of a communication port of an ink cartridge, serving as an ink tank, according to a second embodiment of the present invention: FIG. 3( a ) is a cross-sectional view of a principal portion of the communication port, and FIG. 3( b ) is a cross-sectional view taken along line b-b shown in FIG. 3( a ); and
[0034] FIGS. 4 ( a ) and 4 ( b ) are diagrams illustrating the configuration of a surrounding structure of a communication port of an ink cartridge, serving as an ink tank, according to a third embodiment of the present invention: FIG. 4( a ) is a cross-sectional view of a principal portion of the communication port, and FIG. 4( b ) is a cross-sectional view taken along line b-b shown in FIG. 4( a ).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Preferred embodiments of the present invention will now be described with reference to the drawings.
First Embodiment
[0036] [0036]FIG. 1 is a schematic cross-sectional view illustrating the configuration of an ink tank according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 represents a cartridge main body for ink-jet recording (hereinafter abbreviated as a “cartridge main body”). The cartridge main body 1 includes, mainly, an opening 2 , serving as an ink outlet for supplying an ink-jet head (not shown) with ink by being connected to the ink-jet head, an air communication port 3 communicating with atmospheric air, a first ink chamber 5 incorporating a negative pressure producing material 4 , and a second ink chamber 8 which directly accommodates ink in a state of being adjacent to the first ink chamber 5 via a partition wall 6 .
[0037] The air communication port 3 includes, mainly, an air communicating hole 9 for causing the inside of the cartridge main body 1 to communicate with atmospheric air, and a plurality of ribs 10 for preventing the negative pressure producing material 4 from directly contacting the air communication hole 9 and for forming an air buffer in a region surrounding the air communication port 3 .
[0038] A communication port 11 for supplying the first ink chamber 5 with ink 7 within the second ink chamber 8 is formed between a base end portion of the partition wall 6 and the base of the cartridge main body 1 . Projections 12 are provided in the communication port 11 .
[0039] Next, the configurations of the communication port 11 and the projections 12 will be described in detail with reference to FIGS. 2 ( a ) and 2 ( b ).
[0040] FIGS. 2 ( a ) and 2 ( b ) are diagrams illustrating the configuration of a surrounding structure of the communication port 11 in the first embodiment: FIG. 2( a ) is a cross-sectional view of a principal portion of the communication port 11 , and FIG. 2( b ) is a cross-sectional view taken along line b-b shown in FIG. 2( a ).
[0041] As shown in FIGS. 2 ( a ) and 2 ( b ), the communication port 11 is formed between the partition wall 6 and a wall w of the cartridge main body 1 . A plurality of (three in the first embodiment) projections 12 is formed on the upper surface of the wall w in the direction of the thickness of the partition wall 6 from the inside of the communication port 1 toward the second ink chamber 8 . One end portion (the left end in FIG. 2( a )) of each of the projections 12 contacts a base portion of the negative pressure producing material 4 in the first ink chamber 5 , and another end (the right end in FIG. 2( a )) extends to the inside of the second ink chamber 8 . Although the length of the projection 12 within the second ink chamber 8 is determined based on the surface tension of the ink 7 , the shape of the communication port 11 , and the like, it must be greater than the size of a grown air bubble which is considered to remain within the communication port 11 during the above-described air-liquid exchange. Accordingly, in general, the length of the projection 12 is preferably at least 2 mm. However, the length is not limited to this value. The reason why the length of the projection 12 must be greater than the size of the air bubble remaining in the communication port 11 is that, even if an air bubble having an ordinary size remains in the communication port 11 , since the right end of the projections 12 reaches the air-liquid interface of the ink 7 within the second ink chamber 8 , the ink 7 can be supplied into the first ink chamber 5 through the projections 12 .
[0042] The height from the upper surface of the wall w and the width of the projection 12 are set to values to allow air-liquid separation by the surface tension of the air bubble, and are preferably about 0.5 mm. The height of the projection 12 is preferably a value equal to or less than the size of an air bubble formed by air-liquid exchange. Hence, if the air bubble has a diameter equal to or more than 1 mm, the height may be equal to or less than 1 mm. The height may be set to a value within a range to allow the movement of the liquid. Hence, even a height equal to or more than 1 mm will cause no particular problem.
[0043] The number of the projections 12 is determined by the width of the opening of the communication port 11 , and the like. In order to provide a difference between the cross section of a bubble-guiding channel provided at an upper portion of the opening of the communication port 11 and the cross section of the liquid transfer channel provided at a lower portion of the opening of the communication port 11 so as to prevent a large grown air bubble from entering between the projections 12 , it is desirable to provide a plurality of projections 12 . It is desirable to determine the interval between the adjacent projections 12 in consideration of the size of the formed air bubble. For example, as described above, the interval is desirably equal to or less than the size of the air bubble. When the air bubble has a diameter of at least 1 mm, the interval is desirably equal to or less than 1 mm.
[0044] In the first embodiment, at the moment when the liquid surface of the ink stored within the negative pressure producing material 4 of the first ink chamber 5 decreases in accordance with consumption of the ink and a part of the liquid surface reaches the communication port 11 , the inside of the second ink chamber 8 communicates with the first ink chamber 5 via the air communicating hole 9 of the first ink chamber 5 , and an air bubble is supplied into the second ink chamber 8 . At the same time, ink having a volume corresponding to the air bubble is supplied to the first ink chamber 5 via the communication port 11 . By repeating such gas-liquid exchange, there is the possibility that air bubbles remain within the communication port 11 .
[0045] In the first embodiment, however, even if an air bubble remains, since a transfer channel for the ink is always secured at a lower portion of the communication port 11 by a liquid transfer channel provided by projections 12 where an air bubble cannot enter, the ink can be supplied from the second ink chamber 8 to the first ink chamber 5 . Hence, not only ink contained in the negative pressure producing material 4 within the first ink chamber 5 but also ink within the second ink chamber 8 communicating at the communication port 11 can be entirely consumed effectively.
[0046] Furthermore, as described above, by assuredly supplying ink from the second ink chamber 8 to the first ink chamber 5 , an air bubble is received into the second ink chamber 8 , so that the stay of the air bubble within the communication port 11 can be prevented. In such a case, since not only the liquid transfer channel at a lower portion of the communication port 11 but also an upper channel can be utilized for supplying ink, ink can be smoothly and sufficiently supplied. In addition, since the contact area of an air bubble on the wall decreases due to the presence of the projections 12 , the remaining air bubble can be easily moved.
Second Embodiment
[0047] FIGS. 3 ( a ) and 3 ( b ) are diagrams illustrating the configuration of a surrounding structure of a communication port of an ink cartridge, serving as an ink tank, according to a second embodiment of the present invention: FIG. 3( a ) is a cross-sectional view of a principal portion of the communication port, and FIG. 3( b ) is a cross-sectional view taken along line b-b shown in FIG. 3( a ).
[0048] The configuration of the second embodiment is basically the same as that of the first embodiment except for a communication port 11 (to be described below). Hence, the same components are indicated by the same reference numerals, and further description thereof will be omitted. The second embodiment has a feature in the shape of projections 13 , serving as a liquid transfer channel provided at a lower portion of the communication port 11 . The projections 12 of the first embodiment only slightly contact the negative pressure producing material 4 , and does not extend to the inside of the negative pressure producing material 4 . To the contrary, the projections 13 of the second embodiment extend to the inside of a lower portion of the negative pressure producing material 4 , and a portion entering the lower portion of the negative pressur producing material 4 is sloped so that its height gradually decreases as it enters the inside.
[0049] It is considered that when unsloped projections contact the negative pressure producing material 4 , the compressibility of the negative pressure producing material 4 abruptly changes, thereby influencing the stability of insertion of an absorbed material. To the contrary, in the second embodiment having the sloped projections 13 , the contact between the sloped portion and the negative pressure producing material 4 is mitigated, so that the negative pressure within the negative pressure producing material 4 does not abruptly change, so that ink supplied from the second ink chamber 8 is easily accommodated within the negative pressure producing material 4 .
Third Embodiment
[0050] FIGS. 4 ( a ) and 4 ( b ) are diagrams illustrating the configuration of a surrounding structure of a communication port of an ink cartridge, serving as an ink tank, according to a third embodiment of the present invention: FIG. 4( a ) is a cross-sectional view of a principal portion of the communication port, and FIG. 4( b ) is a cross-sectional view taken along line b-b shown in FIG. 4( a ).
[0051] The configuration of the third embodiment is basically the same as that of the first embodiment except for a communication port 11 (to be described below). Hence, the same components are indicated by the same reference numerals, and further description thereof will be omitted. The third embodiment has a feature in the shape of a liquid transfer channel provided at a lower portion of the communication port 11 . In the first embodiment, the liquid transfer channel is configured by the projections projected from the upper surface of the wall w. To the contrary, the liquid transfer channel of the third embodiment is configured by a plurality of grooves 14 which extend to the inside of a lower portion of the negative pressure producing material 4 within the first ink chamber 5 , and extend to the inside of the second ink chamber 8 . The depth of the grooves 14 does not change from the second ink chamber 8 to a portion below the partition wall 6 , and then gradually decrease in a portion below the negative pressure producing material 4 .
[0052] In the third embodiment, the liquid transfer channel formed at a lower portion of the communication port 11 is configured by the grooves 14 . As in the above-described case of the projections, it is desirable that the groove 14 has a width equal to or less than the diameter of the air bubble formed by gas-liquid exchange because the air bubble is prevented from entering the groove 14 and a transfer channel for the liquid can be secured. For example, as in the above-described case, the width may be equal to or less than 1 mm, and preferably, equal to or less than 0.5 mm. The groove 14 may have a depth to secure a transfer channel for the liquid in a state in which an air bubble remains. For example, considering that the formed air bubble has a diameter equal to or more than 1 mm, the width may be equal to or less than about 1 mm. Of course, a width equal to or more than 1 mm may be adopted provided that entering of an air bubble is prevented by the width of the groove 14 . By thus providing the grooves 14 , even if an air bubble remains within the communication port 11 , the air bubble cannot enter the groove 14 . Hence, a flowing channel only for ink can always be secured. As a result, ink within the second ink chamber 8 can be effectively consumed.
[0053] In the third embodiment, since the liquid transfer channel comprises recesses, the negative pressure producing material 4 is less deformed, so that a uniform negative-pressure distribution can be easily obtained.
[0054] Although in the third embodiment, the liquid transfer channel is configured by a plurality of recesses, projections as in the foregoing embodiments may be provided between adjacent recesses. In such a case, the difference between the apices of the projections and the bases of the recesses is appropriately adjusted so as to secure an ink flow channel where an air bubble does not enter which is formed at a lower portion of the communication port 11 .
[0055] As described above, according to the present invention, even if an air bubble remains at an upper portion of the communication port, it is possible to assuredly and sufficiently supply ink within the second ink chamber to the first ink chamber through the liquid transfer channel provided at a lower portion of the communication port.
[0056] Even if an air bubble remaining in the communication port regulates the interface of ink within the second ink chamber to separate the interface of the ink from the communication port, ink within the first ink chamber can be assuredly supplied by providing a long liquid transfer channel so as to contact the interface of the ink.
[0057] The individual components shown in outline in the drawings are all well-known in the liquid tank arts and their specific construction and operation are not critical to the operation or the best mode for carrying out the invention.
[0058] While the present invention has been described with respect to what are presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
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A liquid tank includes a first chamber which incorporates a liquid and a negative pressure producing material and which includes an air communication port for obtaining communication with atmospheric air, and a port serving as an ink outlet. The liquid tank also includes a second chamber for directly accommodating the liquid to be supplied to the first chamber in a substantially closed state although communicating with the first chamber only via a communication port which is provided at a position separated from the air communication port. The communication port is formed between a partition wall for separating the first chamber from the second chamber, and a chamber inner surface which is a border region between the first chamber and the second chamber where an end portion of the partition wall contacts if the partition wall is extended. A liquid transfer channel which is longer than a length of the partition wall in the direction of the thickness of the partition wall is provided along the chamber inner surface of the communication port.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from Provisional U.S. Patent Application Ser. No. 61/013,654, filed on Dec. 14, 2007 and incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of network management. In particular, the present invention is directed toward a method and apparatus using techniques to optimize bandwidth usage in networks.
BACKGROUND OF THE INVENTION
[0003] Broadcasting, as we know it, may be coming to an end. The concept of broadcasting, first in radio, and then in television, could be said to have been invented by David Sarnoff, head of Radio Corporation of America (RCA) and founder of the National Broadcasting Company (NBC). Prior to his involvement with RCA, radio was considered a point-to-point two-way communications device, similar to the telegraph (hence the term “wireless” or “wireless telegraph”). The idea of a single broadcasting station or network sending the same content to a number of simple receiving sets revolutionized the radio business and also our culture.
[0004] The advent of newer communications networks, such as the Internet, and increasingly, multimedia communications devices such as media-enhanced cellular phones, threatens to spell the end of conventional broadcasting. Instead of turning on the television and “seeing what's on,” today's users are increasingly turning on their computers and deciding what to watch. Users are no longer tied to the concept of broadcast time-slots, television “seasons” and the like. Users can watch what they want to watch, when the want to watch it.
[0005] However, despite the enormous amount of media content available on the Internet, users tend to follow certain patterns of consumption. Popular movies and recent releases tend to be viewed by a large number of people within a certain time period, particularly if the content has been heavily promoted. Users tend to trend toward certain content types and genres as well. Thus, despite the enormous choices available from Internet-based media, users tend to follow well-worn paths.
[0006] Determining which content to watch can be daunting. Moreover, in the absence of traditional broadcasting channels, content providers may find it difficult to advertise their content to interested viewers though the background noise of all these choices. A means for aiding in the selection of content, as well as an improved method of intelligently broadcasting content to users remains a requirement for this new art.
[0007] Advertising in the traditional sense, however, is less than effective in promoting media consumption. Users view advertisements for unwanted content as annoying. On the other hand, the same users will find advertising for desired content as timely and useful. Targeting users for advertising content results in a more efficient use of advertising revenues and also results in better feedback from users. Major search engines (e.g., Google™ and the like) as well as other web sites (e.g., CNN website) are already using such targeted advertising, by using user search terms or article selections to select corresponding banner advertisements, pop-up ads, sidebar ads, or the like. Given the large amount of clutter on the Internet, a targeting method of reaching consumers with media content would be desirable.
[0008] Ironically, networks such as cellular phone networks (GSM or 3G or the like) and cable modem communications, satellite broadband, fiber optic, and the like, while acting a point-to-point two-way communications networks, are actually broadcasting networks. As many politicians and celebrities discovered to their dismay, Prior Art analog cellular telephone networks broadcast voice signals such that anyone with a radio receiver could receive them. The cellular devices themselves were merely programmed to play only that audio content intended for that device.
[0009] Modern digital cell phones have solved this problem, as the audio signal is digitized and then encrypted, such that only the device for which the signal is intended may decrypt and playback the signal. However, the encrypted digital signal is still available for anyone to intercept via a radio receiver—although decrypting such data may be very difficult. In a similar manner, many broadband services, including but not limited to cellular modem, satellite broadband, fiber optic, and the like, may also broadcast data in a manner than any user can intercept it, with proper tools. However, again since the data may be encrypted, it is difficult for other users to intercept the data.
[0010] Shared networks like this determined which devices are to receive the data by indicating, via a digital tag or the like, which devices on the network are to receive the data. In present-day applications, each device may receive data intended for other users on the network, but will only download and decrypt data intended for the user of a particular device. However, it is technically feasible for multiple users to download and decrypt the same data from the same data stream on a shared network. Thus, the point-to-point networks of the Internet and cellular phones could be used as broadcasting networks. However, to date, no one has taken serious advantage of this broadcasting aspect of these new networks.
[0011] Mike Daniels, in a published interview with TechBisNow, distributed on Oct. 19, 2007, incorporated herein by reference, stated that with mobile devices outnumbering computers by a factor of two or three, he sees a gigantic market—and huge opportunities for firms that marry wireless devices with web-based and other applications. Other industry analysts predict that wireless devices will outnumber computers significantly over the next several years.
[0012] The growth in this industry segment has spawned opportunities for companies situated between the users and content providers. For example, Sybase, of Dublin, Calif., (Website at sybase.com, incorporated herein by reference), is a company that provides mobile messaging services, and, according to its website reaches more than 1.7 billion mobile users globally—77 percent of the world's current subscribers. Sybase represents a new provision of service, from the delivery and settlement of mobile messaging interoperability to the management and distribution of mobile content via Short Message Service (SMS), Multimedia Messaging Service (MMS) and Wireless Application Protocol (WAP). According to the company, Sybase 365 processes more than 6 billion messages monthly and is positioned between mobile operators, enterprises, global brands, and mobile content providers. The company offers services to facilitate mobile data and content delivery, as well as complete backend payment and settlement solutions. Sybase 365's global interoperability is advertised as providing uninterrupted SMS and MMS messaging between technically disparate and geographically dispersed networks.
[0013] In an article titled Off the Hook in the July, 2007, edition of the IET's Engineering and Technology publication, incorporated herein by reference, Walter Tuttlebee, Chief Executive of Mobile VCE, a strategic research organization for mobile operators and equipment suppliers, presented scenarios for future supply of personalized lifestyle services using cell phone features. Tuttlebee described the following scenario for a customer with a personal profile: The customer syncs his phone with his PC so that when he flies from London to Brazil his e-ticket arrives in his e mail inbox and automatically gets transferred to his phone. His handset knows which day he will be flying from Heathrow, so it caches the map to get the driving directions. It books his parking space at the airport and it registers when he arrives at the airport and checks him in automatically. He then gets an acknowledgement on his phone, which he uses to hold up to a scanner to check his luggage for the flight. When he arrives in Brazil the system loads the directions to get the bus or taxi to the hotel. When he gets to the lobby it registers that he has arrived at the hotel, automatically checks him in, and downloads an electronic key to his phone. He walks to the room where the TV has already been automatically set up to all of his home channels. All of the above happens automatically without requiring user input throughout the process.
[0014] In the Article Into the Frontline published in the August/September 2006 issue of the IET Engineering Management magazine, incorporated herein by reference, Paul Clapman discusses cell phone product development. He cited cell phone product development as falling into the school of “because we can.” He stated that mobile phone functionality “increases exponentially but for the vast majority of users most of those functions are used little or not at all. How many owners actually need the telephone equivalent of a Swiss army knife which, as well as sending and receiving calls and text, can send e mails, download music, take photographs show movies and TV? His answer was “very few.” “But enough people want that level of perceived technical advancement to create the market,” he added. “Those added functions create opportunity for brands to increase their share of shout in a buoyant market and they are an awful lot easier to sell than excellent reliability or premium quality of reception. Certainly in this instance customers value ‘more’ ahead of ‘better.’”
[0015] A good example of a state-of-the-art cell phone is the Apple iPhone. In a review by CNET, Apple iPhone 0 8GB (AT&T), 2007, incorporated herein by reference, many of the new features provided by the Apple iPhone were described. While the iPhone received much attention from the public, it provided many new cell phone features but also omitted other features that were generally expected in state of the art devices. Features that were not included in 2007's first generation iPhone included multi-media messaging and 3G capabilities. Also, the phone was essentially locked into one network provider (AT&T in the U.S. and others in various different countries) when initially released, although the company subsequently advertised plans to unlock the phone.
[0016] From a design point of view, the iPhone had no external antenna and no buttons, relying on a versatile touch screen display. The CNET reviewer pointed out that although the Apple handset is not the first cell phone to rely solely on a touch screen, it is the first phone to get so much attention and come with so many expectations in the market. Depending on what the user is doing, the touch screen serves as the dial pad, keyboard, Safari web browser, and music and video player. The reviewer went on to state that the iPhone offers a full range of wireless functionality with support for Wi-Fi and Bluetooth connectivity. The Wi-Fi compatibility is especially welcome, stated the reviewer, and a feature that's absent on far too many smart phones. The iPhone's 2-megapixel camera records still images but not video surprisingly, although that is fast becoming a standard feature on many cell phones. Also, the iPhone includes a fully functioning fifth-generation iPod for music. The bundled features include visual voicemail, and a built-in Google Maps application, although no GPS.
[0017] Third Generation, or 3G, technology is the latest in mobile communications while analog cellular technology may be considered to be generation one and digital/PCS generation two. 3G technologies are intended for multimedia cell phones and feature increased bandwidth and transfer rates to accommodate Web-based applications and phone-based audio and video files. 3G comprises several cellular access technologies including:
[0018] CDMA2000—based on 2G Code Division Multiple Access
[0019] WCDMA (UMTS)—Wideband Code Division Multiple Access
[0020] TD-SCDMA—Time-Division Synchronous Code-Division Multiple Access
[0021] For a good description of each of these technologies, refer to: the website electronics.howstuffworks.com/cell-phone5.htm incorporated herein by reference.
[0022] 3G networks have potential transfer speeds of up to 3 Mbps (about 20 seconds to download a 4-minute MP3 song). For comparison, the fastest 2G phones can achieve up to 144 Kbps (about 10 minutes to download a 4-minute song). 3G's high data rates are ideal for downloading information from the Internet and sending and receiving large, multimedia files. 3G phones are like mini-laptops and can accommodate broadband applications like video conferencing, receiving streaming video from the Web, sending and receiving faxes and instantly downloading e-mail messages with attachments.
[0023] The daily electronic news e-mail, DailyTechRag, [editors@dailytechrag.com] dated Oct. 22, 2007, incorporated herein by reference, stated that WiMAX has been officially certified as a 3G standard by the UN's International Telecommunication Union. According to the source, this means that WiMAX is now the sixth official form of 3G technology, and that WiMAX can now legally use airwaves that have been designated for 3G use.
[0024] In an article Up The Revolution in the January 2007 IET Magazine of Engineering and Technology, incorporated herein by reference, William Webb, a fellow of the IET and the Royal Academy of Engineering, attempted to predict the overall direction of the wireless communications industry over the 20 years. He forecasted that in fixed networks he expects IP-based core networks to be deployed, with more fiber to the curb, and in some cases to the home. He predicts that personal video recorders will be used to assemble personal channels from a range of sources, reformat the content and distribute it to handsets and other portable devices by around 2020. Conversely, he predicts little change in cellular apart from increased coverage and capacity as cell sizes shrink.
[0025] Specifically, Webb does not see a new technology such as 4G being deployed in the next 20 years. Handsets, he predicts, will see incremental enhancements in displays, storage capacity and functionality, including much better speech recognition. Users, Webb predicts, will see a steady but substantial change over the next 20 years and will rely on the handset for as a single device to manage not just communications but many aspects of their lives. Users, he predicts will see the world as one large communications network, able to provide them with whatever content they need wherever they are.
[0026] It is therefore logical to predict that bandwidth capacity of data networks and cellular bandwidth will be a key issue going forward or a limiting factor, as we have a possible scenario of the basic 3G infrastructure supporting exponential growth in applications for the foreseeable future. Furthermore, techniques for bandwidth management will continue to play a key role in the developing data communications infrastructure for messaging and content delivery.
[0027] At the same time, the amount of memory (storage) available in handheld devices has increased significantly—often beyond the needs of the users. While the demise of rotating magnetic media (hard disk drives or HDD) has been predicted for years, continual advances in HDD technology have resulting in smaller and less costly devices with greater and greater memory capacities. Thus, from the standpoint of hand-held media devices, the limiting factor for transmitting and playing back media files lies more in bandwidth limitations than in any limitations in storage capabilities.
[0028] A fundamental tool for bandwidth management is data compression. A good description of compression techniques is provided in Tom Sheldon's 2001 book, The Encyclopedia of Networking and Telecommunications, incorporated herein by reference. Lossy and lossless compression techniques are employed for data transfer depending on the application (e.g., video and audio are transmitted with some form of lossy compression, while other files may be transmitted with lossless compression). Lossy compression can offer up to 200:1 compression while lossless compression usually only achieves a 2:1 ratio. Compression techniques include null compression, run length compression, keyword encoding, and adaptive Huffman coding and Lempel-Ziv algorithms.
[0029] For example, as described on Cisco's website: http://www.cisco.com/warp/public/cc/pd/iosw/tech/compr_wp.htm, incorporated herein by reference, Cisco uses STAC and Predictor compression algorithms, which are based on the Lempel-Ziv compression algorithm. The Cisco router software uses an optimized version of LZS that provides good compression ratios but requires many CPU cycles to perform compression. LZS is available in Cisco's Link Access Procedure, Balanced (LAPB), HDLC, X.25, and frame relay data compression solutions. While these techniques offer anywhere from 2-200:1 compression, available bandwidth capacity is still a significant pacing factor for the industry.
[0030] In an article in the October 2007 edition of the IET magazine, incorporated herein by reference, David Sandham reported on the 2007 International Broadcasting Convention, IBC2007. Sandham comments that Internet Protocol (IP) is fast becoming the de facto standard for all forms of communications including video. Called IPTV, for Internet Protocol Television, the format allows for the tailoring of content to individual users, as individual programs may be sent to small groups or individual users. Sandham went on to report on the compression techniques used by IPTV, starting from MPEG-2 five or six years ago, and now MPEG-4 which brought bandwidth savings of the order of 50% over MPEG-2.
[0031] In Ben Patterson's Blog, dated Oct. 12, 2007, http://tech.yahoo.com/blogs/patterson/7269, incorporated herein by reference, he provides a review of a TV set-top box that uses peer-to-peer networking to deliver near-DVD quality videos. The product is called Vudu, containing a 250 GB hard drive, which is enough for 100 hours of standard-definition movies. The company offers 5,000 movies in an “on demand” format, to use the terminology used by conventional cable and satellite TV providers. Patterson notes that while most Internet-connected set-top boxes take upwards of 20-plus minutes to download a two-hour standard-def movie, the Vudu starts playing immediately. It does this by being pre-loaded with the first 30 seconds of the most popular movies. The headers download in the background onto unused portions of the hard drive, and due to peer-to-peer networks, each Vudu box shares the load in terms of downloading any given movie.
[0032] Peer-to-peer (or P2P) networks use diverse connectivity between network participants and the cumulative bandwidth of network participants rather than conventional centralized resources where a relatively low number of servers provide the core value to a service or application. Peer-to-peer networks are useful for sharing content files containing audio and video and real-time data, such as telephony traffic, is also passed using P2P technology.
[0033] The company, Vudu, (See, www.vudu.com, incorporated herein by reference), requires a minimum available bandwidth of 2.0 Mbps (usually advertised by ISPs as 3.0 Mbps, according to Vudu) for instant viewing of movies. Note that all references here are for standard definition, i.e., 480 p, and not 1080 p high definition formats, which will require higher bandwidth and capacity. Patterson, in his review referenced above, cites a period of several hours to download high definition movies to an Xbox.
[0034] While in this example peer to peer allows for distributed sources of content, it does not necessarily cut down on the use of overall bandwidth by a particular user, and that user is limited by the lowest bandwidth point in the network, e.g., normally from the home to the ISP provider for residential users.
[0035] There are other various techniques available to optimize the use of bandwidth. In U.S. Pat. No. 7,283,491, “Communication System and Method Capable of Broadcasting by Using Terrestrial and Satellite Communication Networks”, incorporated herein by reference, a system for using satellite and terrestrial networks as an adjunct to the Internet for multi-casting is described. The main feature described is the use of unused time slots to multicast information such as movies, thereby making use of otherwise unused bandwidth capacity.
[0036] Another technique, in Published U.S. Patent Application 2007/0240185, entitled “Methods, Apparatuses, and Computer Program Products for Delivering Audio Content on Demand”, incorporated herein by reference, describes a system for providing audio on demand. Specifically, the Patent Application describes a method of delivering on-demand audio content, comprising reception of a selection of audio content for listening to on-demand while receiving an input specifying delayed listening and determining that the audio content is to commence before expiration of a predetermined time interval. If that time interval has not expired, other listeners may join in the multicast. If the time interval expires, then the single user requesting the audio on demand can listen to the audio, in unicast, albeit slightly delayed. This technique improves upon bandwidth usage by straight unicast by multicasting to users who opt to receive the content simultaneously.
[0037] U.S. Pat. No. 6,466,918, entitled “System and Method for Exposing Popular Nodes Within a Browse Tree,” incorporated herein by reference, describes a method for identifying popular nodes within a browse tree or other hierarchical browse structure based on historical actions of online users, and for calling these nodes to the attention of users during navigation of the browse tree. While this is tailored for an on-line store, such as that provided by Amazon, it is one of many techniques to identify user preferences based on previous user selections and transaction history.
[0038] This type of technique may be extrapolated to identify potential users of specific broadcast download content, i.e., those users who may like a particular actor, actress, or performer in a video or audio presentation.
[0039] Marks, U.S. Pat. No. 6,463,447, issued Oct. 8, 2002 and entitled “Optimizing bandwidth consumption for document distribution over a multicast enabled wide area network” and incorporated herein by reference, discloses a method for filtering documents. Marks receives a document off of a multicast channel and determines whether the document includes relevant information. A filtering agent retrieves meta data from the document. An evaluation unit whether the document includes relevant information based on session identification, Meta data, and source information. Marks discloses his “documents” can include media files. However Marks requires an extensive filtering regime to determine whether a document should be loaded into a user's computer.
[0040] Mover, this filtering regime takes place on the user's computer, which requires that the user receive all file metadata, filter the data, and then decide whether to download the data. The use of metadata, while intending to save on processing time, bandwidth, and memory, actually ends up burdening the processor and end device, as the device must check each file being sent over the common data path and then determine whether the meta data indicates the file should be downloaded. While the Marks system might work in a cable modem environment where a number of computers are connected to a common data link (coaxial cable), such a filtering scenario might not be as workable with portable wireless devices such as portable media players and the like.
SUMMARY OF THE INVENTION
[0041] A system and technique are described to enhance the use of limited bandwidth by intelligent broadcast, which would allow many more users to access content that was broadcast or downloaded by another user or group of users. While many users may download content that is specific to them, e.g., a flight itinerary, other users download the exact same content, e.g., a song or a movie, so the net result is that a significant portion of finite bandwidth is used repeatedly to download the same content. Furthermore, users, based on the type of user, or profiled users, will download the same content in the same general time period, for example, the release of a popular new album, movie or video. Content providers and wireless providers, who may be the same or different entities, may then share in the benefits of this approach, e.g., the savings in bandwidth usage and the improved distribution to the end user.
[0042] The present invention is different from the peer-to-peer (P2P) approach used by Vudu, discussed previously, which basically relies on distributing the source of content through various users. Intelligent broadcast transmits or broadcasts content, or partial content, simultaneously to groups of users, much in the way conventional radio or TV is broadcast, but over various communications systems based on the preferences exhibited by those users, or other user profiling.
[0043] Unlike the Marks Patent, discussed previously, the present invention does not require filtering of meta-date or other actions in order to determine content suitability. Rather, it is the system itself, in the form of a broadcast profiler, that may select which users are most likely to select the broadcast content and thus direct the transmission to the users most likely to use the content. The user device does not have to perform any filtering of metadata or other data, as the media is directed toward the user from the system, based on user behavior patterns, rather than the user's device selecting based on user-input preferences.
[0044] The present invention may be applied to wireless devices such as mobile phones with built-in capability to play music or view video, or other types of portable media players and the like either already in production or shortly to be introduced. Note that in the present description, the device is described as being used with a portable media player such as a mobile phone. However, with the rollout of wireless broadband, such devices may also be non-portable devices for use in the home, or media players built-in to automobiles or other vehicles.
[0045] In another embodiment of the present invention, fixed-base users such as computers, televisions, home theater and game consuls may employ intelligent broadcast to minimize bandwidth usage locally, regionally, and nationally. In this embodiment, intelligent broadcast may be used on a common data path (wireless broadband, cable modem, fiber optic, or the like) where a number of user computers may be connected to a common data path. However, unlike the Prior Art Marks Patent discussed above, the user destination is determined at the system level, not by using meta data at the user level.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 is a block diagram of the first embodiment of the present invention for intelligent broadcasting of content over networks.
[0047] FIG. 2 is a block diagram of the second embodiment for streaming of real-time content to mobile devices at a stadium.
DETAILED DESCRIPTION OF THE INVENTION
[0048] Referring to FIG. 1 , in the preferred embodiment of the present invention, a system is shown for intelligent broadcasting of content to mobile devices. Again, please note that the present invention is described in terms of mobile devices, but may be applied to home computers and other entertainment devices as well. Thus, the present description of FIG. 1 in terms of mobile devices should not be construed as limiting the present invention to that embodiment, but is provided by way of illustration only.
[0049] The users, using mobile devices 100 , 110 , 120 , 130 , make requests to download content from their respective service providers 200 , 210 , and 220 . Mobile devices in this example may include media-compatible portable devices such as an Apple™ iPhone™ or the like. The requests may be made by the users independently and unsynchronized in time, and may be for different content. For example, one user may request an audio file, such as a new music album, at 10 AM and another user may request a video file, such as a movie, at 10:30 AM.
[0050] User requests for content are passed from the service providers 200 , 210 , 220 to the content providers 300 , 310 . Service providers 200 , 210 , and 220 may comprise, in this example, cellular telephone service providers, which provide cellular telephone communications services to users 100 , 110 , 120 , and 130 . Content providers 300 , 310 may be music or video stores, such as Apple's iTunes™, Amazon, and the like. Content providers 300 , 310 may be linked to service providers 200 , 210 , and 220 via an interface on the user's phone, such that the user can visit the Content provider's “store” through the user's phone. If the phone is provided with web-browsing capability, the content provider may comprise any web-based media or other provider.
[0051] Content providers 300 , 310 , either independently or in conjunction with other parties, such as service providers 200 , 210 , 220 , will update broadcast profilers 400 , 410 based on the new requests for content. Unlike traditional profiling techniques that identify popular nodes within a browse tree for a specific user, the profiler identifies other users with similar selection histories.
[0052] Thus, for example, broadcast profilers 400 , 410 may be programmed to review the history of media selections by users 100 , 110 , 120 , and 130 . Similar algorithms are already known in the art and are presently used by Amazon™ and Netflix™ to suggest to users, based on previous selections, additional media content may be of interest. Thus, for example, if a user selects a number of foreign language films, the algorithm may suggest to the user additional foreign language films of interest. The algorithm may be further fine-tuned by other categories as well, such as action films, romance, film noir, art films, drama, director, actor, and the like.
[0053] This algorithm may be operated by consulting a metadata database, which provides a lookup of metadata tags based upon the name of the media content. For example, the film “Rambo” may have associated metadata including the genre “Action/Adventure” as well as actor and director names, and other indicia. This metadata need not be attached to the media file itself (which may comprise, for example, an MPEG file or the like), but can be retrieved from a lookup table accessed by the content title or other indicia (catalog number, ISBN or the like).
[0054] Thus, unlike Marks, which requires that metadata be inserted into the file before transmission, the present invention can retrieve metadata from independent data sources (e.g., imdb™, the Independent Movie Database). And unlike the algorithm used by Amazon™, Netflix™ and others, in the present invention, the algorithm selects users interested in the content, instead of content which may be of interest to the user. This identification is achieved by reviewing the user's past purchase or request patterns. It also may be modified by the user indicating a preference for certain content types or the like. However, unlike Marks, this content preference is uploaded from the user device to broadcast profilers 400 , 410 , such that filtering of content need not take place at the user device.
[0055] Profilers may also make use of information from third party applications such as browsers or search engines to indicate preference for media content. Thus, for example, a user may be surfing the web for information regarding a certain actor, director, film genre, author, or actual film title. The user has not requested this content to be downloaded to his device. However since the user has searched for this content or similar content, it may be inferred that similar content may be of interest to the user based on browsing history.
[0056] Broadcast profilers 400 , 410 identify a group of mobile device users for simultaneous reception of the requested content, via the service providers. FIG. 1 shows broadcast profiler 400 identifying mobile device users 500 , 510 , 520 , and broadcast profiler 410 identifying mobile device users 510 , 520 , 530 . Note that users 500 , 510 , 520 , and 530 may or may not be the same users 100 , 110 , 120 , and 130 requesting content.
[0057] Service providers 200 , 210 , 220 or the content providers 300 , 310 simultaneously broadcast a complete copy or a partial copy of the requested content to each group of mobile device users 500 , 510 , 520 , and 530 . The simultaneous broadcast, or “multi-cast” transfers the content to multiple users, who may or may not choose to access the content through some means of payment or other authorization. This allows the content providers 300 , 310 mass access to users and to potentially use less service provider bandwidth 200 , 210 , 220 to distribute files.
[0058] Mobile device users 500 , 510 , 520 , 530 may access the broadcast content at any time after the broadcast has commenced. Users who did not specifically request to download the content may receive partial downloads, such as the first half of an album or movie, depending on user preferences or available cache memory in the mobile device.
[0059] If the user who did not specifically request to download the content later decides to select the same content for download and/or purchase, the content is already located on his device (in whole or part) and thus no additional bandwidth (or less additional bandwidth) is required to transmit the content to that user. If the user who did not specifically request to download the content does not decide to download and/or purchase that content, the content may remain in the user's device for a predetermined period of time, or until space in the device is needed for further content or data. At such a time, the unpurchased or unselected content may then be deleted from the user's device.
[0060] An example of the operation of the system of the present invention is as follows. Users 100 , 110 , 120 and 130 make content requests through their mobile devices, which may comprise, for example an Apple™ iPhone™ or the like. In this example, users 100 , 110 , 120 , and 130 may be requesting a recent film release, such as the new James Bond film, “Quantum of Solace.” Service providers 200 , 210 , and 220 process these requests to content providers 300 , 310 . Content providers 300 , 310 may comprise an online media store such as Amazon™, iTunes™, Netflix™ or the like, which provide media (movies, television programs, books, music, video games, and the like) to end users over Internet or other connections.
[0061] Content providers 300 , 310 prepare to transmit the media files to the users 100 , 110 , 120 , 130 which requested the files. However, since these files are to be sent over a common data path, such as a cellular network or cable modem or the like, any user on this data path may be provided with access to the file. Downloading all files to all users may be cumbersome and use up user memory on the user device rather quickly. Filtering at the user device using metadata as suggested by Marks may be cumbersome, as the user device needs to monitor all content and decide whether to download the data.
[0062] Broadcast profilers 400 , 410 may “profile” users 500 , 510 , 520 , and 530 as being customers potentially interested in the content being transmitted. In this example of the James Bond film, once it is released on iTunes™ or another online store, there may be significant demand, particularly if it is a new release. In the Prior Art, each request for this media content by users would require a separate download of the media file, resulting in a horrific waste of bandwidth, as the same media file is downloaded over the common data link over and over again—literally thousands, if not millions of times.
[0063] Broadcast profilers may decide that users 500 , 510 , 520 , and 530 are interested in the content based on a number of criteria. For example, user 500 may have previously purchased other James Bond films for download to his device. User 510 may have downloaded Daniel Craig movies in the past or movies directed by Marc Forster. User 520 may have performed a search on the terms “James Bond”, “007”, “Daniel Craig”, or “Marc Forster” in the last 30 days. User 530 may have visited the movie's website or viewed web pages related to the movie. Or any of the users 500 , 510 , 520 , and 530 may simply have indicated an interest in Action/Adventure movies as indicated by previous purchases. And of course, any combination of these actions or similar actions may be used by broadcast profilers 400 , 410 to determine which users may be interested in the content.
[0064] Not illustrated in FIG. 1 are users who are not selecting the content and/or are not targeted by broadcast profilers 400 , 410 to receive the content on their mobile devices. A user who expresses interest only in costume dramas, for example, might be filtered out as not be interested in loud action/adventure films. Additionally, users may upload a preference indicator to opt out of such intelligent broadcasts, and thus be excluded from consideration.
[0065] Various forms of opt-out, opt-in, negative option, and the like, may be used to include or exclude users as well. In one embodiment, users may opt-in to intelligent broadcast by selecting such an option on their media device or by visiting a website or the like. The motivations for opting-in to such a service includes the ability to more quickly download media content, and also to have media content suggested to the user based upon their preferences. In addition, users may be encouraged by special pricing discounts and other incentives (credits toward future media purchases, and the like). By opting-in to such an arrangement, the user may agree (in a Terms of Service or TOS statement) to waive certain privacy rights by allowing broadcast profilers 400 , 410 to (anonymously) monitor the user's media usage for filtering purposes.
[0066] Note also that media and content providers (e.g., movie studios and the like) may pay fees to have their content intelligently broadcast to user devices, in order to encourage consumption of media. Such financial incentives may be used to offer reduced prices for selected media to end-users. Once a media file is loaded to a user's device, a message may appear on the user's device announcing or advertising the content. The user may then be encouraged to play the content, at which point his device will be billed for the content. The user receives the content faster and more easily than a Prior Art manual download, and at a possible lower cost to the user. The service provider saves on bandwidth by broadcasting the same media file once to a number of users instead of individually to each user. And the content provider sells more copies of the content to end users as the file is automatically loaded to the user, encouraging impulse purchases, and moreover the filtering technique allows for better targeting of audience for media content.
[0067] Thus, in the present example, once users 500 , 510 , 520 , and 530 have been targeted as being receptive to the new James Bond movie, the media file (MPEG or the like) is then sent over the data path (cable modem, GSM, or the like) to the users 100 , 110 , 120 , 130 who selected and ordered the film, and also to the targeted users 500 , 510 , 520 , and 530 who may be interested in viewing the film as well. Since the media file is sent over a common data path, the file may be transmitted once, but received by a plurality of users, thus saving on bandwidth. Users 100 , 110 , 120 , and 130 may commence watching the video at a time of their choosing or save it on their media device for later playback.
[0068] If one of users 500 , 510 , 520 , and 530 decide to order the film, it may play immediately, as it is already loaded on the user's device. Alternately, the user device may send a message to the user (as a text message, voicemail, graphic, or video) indicating that the file is available for immediate playback. For example, when the media device is activated, a trailer for the film may play, enticing the user to playback (and thus purchase) the entire media file.
[0069] The present invention operates in a manner transparent to the end user. That is, the downloading of unselected content is automatic to the device and does not require any intervention by the user. If the user selects to purchase or download content that has already been loaded to his device, the content will be enabled, and the user will benefit from nearly instant access to the content in question, rather than waiting for a new and complete download of the content. Similarly, if the user does not select the content for download or purchase, the content may later be deleted from his device without the user ever knowing that the content was on his device, and without the user having to intervene in the process.
[0070] To prevent users from “hacking” into unpurchased content downloaded to their device, any number of techniques may be used to encrypt such data using keys and the like to prevent the user from unauthorized access to the content until it is purchased or selected. In this manner, users will not be able to illegally access copyrighted or confidential material stored on their device.
[0071] While described in the context of downloading movies and videos and other Internet content, the present invention may also be used in other contexts. For example, map data may be downloaded to a group of users in a geographical location for use in mapping software on a portable device (e.g., GPS enabled device or the like). For users selecting a mapping function, this map data may be enabled (purchased or otherwise enabled, for example, as part of a mapping service). For users not selecting this feature, such data may be discarded. Thus, the present invention not only saves in bandwidth of transmission, but also in memory usage for user devices.
[0072] Similarly, the present invention may be used to distribute data to members of a group using a common database. For example, employees of a company may receive updated data relating to their company (order and sales data, project data, and the like) automatically loaded into their devices using common bandwidth. Employees who use such data will enable those portions of the data, which will be saved to the device. Data that is not used or enabled may be later deleted to make room for new data transmitted to the group.
[0073] In other scenarios, data may be transmitted to a group of employees, such a delivery service employees (e.g., UPS, FedEX, and the like), including common data for tracking packages, and the like. Again, employees who use particular data will enable that data which may be saved for a period of time, or until the data is no longer needed (i.e., package delivered). Data that is not used or enabled will be deleted sooner.
[0074] While the example of movie files has been used herein, other types of data and media may also be used. For example, similar filtering techniques or preferences could be used to download books to a user's device using user preferences, either inferred from user purchases and actions or by preference (e.g., New York Times best seller's list, Mysteries, Romance, Suspense, Novels, Political, Humor, Author, or the like). Thus, a user could have instant access to a number of books of interest, without having to download each of them manually. In addition, publishers can use the present invention to promote books to interested readers in a targeted manner.
[0075] Similarly, music files from such stores as iTunes™ could be automatically downloaded to a user's device using selection criteria (e.g., by category, such as Top 40, Adult Contemporary, Country/Western, Rock, Hip Hop, or the like, or by Musician, Group, Composer, or the like). In this manner, music could be made available to a user and promoted to interested users.
[0076] Note also that the present invention is useful for users who are out of touch with the network for periods of time. In some areas, network reception may be limited or impossible, or bandwidth may be too limited to download media files. Alternately, users may be roaming on competing networks where bandwidth may be costly. In some buildings, reception may be difficult. On airplanes, users are not presently allowed to use cell phones, although in-flight cell phone and broadband communications are presently contemplated. Even on aircraft allowing for cell phone or broadband communications, data bandwidth may be limited for media downloads.
[0077] Since the present invention has already downloaded media to a user's device, new media may be available to the user without having to access the network, or in a network of limited bandwidth. In the latter scenario, if only a portion of the media file has been downloaded, the remainder can be downloaded in a timely manner on a network of limited bandwidth, such that the user has an uninterrupted use of the media.
[0078] As noted previously, the present invention may download the entire media file, or just portions thereof (chapters, or the like). The user device may manage unused memory such that non-requested media files occupy unused space. As more memory in the device is required for the user, non-requested media files may be deleted on a FIFO (First In First Out) basis or using other criteria. In this manner, the amount of memory “used” by non-requested media does not even appear to the user, and thus his media device memory is not overloaded by un-requested media.
[0079] Note that in the previous description, downloading of media content is initiated by users 100 , 110 , 120 , and 130 who request such content. However, it is within the spirit and scope of the present invention to provide such content even in the absence of such download requests. Content providers 400 , 410 may intelligently broadcast media to users 500 , 510 , 520 , 530 based on profile preferences. In this manner, content providers 400 , 410 may be able to send out “new releases” or promoted media, even in the absence of requests for such media.
[0080] In addition, the service providers 200 , 210 , 220 may utilize off-peak bandwidth to transmit such promoted media to users. Since such media is not being broadcast in response to a specific request, it may be transmitted at times when network data usage is at its lowest (e.g., 3 AM). Thus, while a user's media player is recharging overnight, it also may be downloading new media content which may be of future interest to the user.
[0081] In a second embodiment, shown in FIG. 2 , common data may be transmitted to a number of users attending an event, such as a concert or athletic event. Many sports fans now attend ball games bringing with them portable televisions to obtain a close-up view of certain plays. Portable devices may also be used in the same way to allow users to view instant replays or close-ups of certain plays in a game. Video data may be streamed to users within the ball park or other arena using WiFi or other transmission means (cellular or the like) and those users who subscribe to the service or enable or otherwise purchase such content may be enabled to view the content on their devices. Users who do not wish to purchase such content (or those who subscribe to a competing service or the like) may not be able to view such content.
[0082] A cellular service provider, for example, can offer this service to their subscribers for free (and not to competing providers, or for an addition fee to other networks) and thus provide an incentive to subscribe to their service. Moreover, the cellular provider may have promotional ties to a sports team or arena, and thus use the present invention to intelligently broadcast video to users in the arena as part of a loyalty and cross-promotional scheme. Since the content is being transmitted to all devices in the area simultaneously, bandwidth is conserved, as the images do not have to be separately transmitted to each user.
[0083] Referring to FIG. 2 , content is broadcast at event 100 via the available service providers 200 , 210 . Service providers 200 , 210 may comprise cellular service providers or WiFi networks or the like. Users 300 , 310 receive the data 250 and may elect to purchase 260 or not to purchase 270 . Alternately selection to purchase 260 or not to purchase 270 may be an indication from the user's device that it is part of a preferred network, or an enabled device. Alternately, users who are enabled to receive the service may be indicated at a central database (e.g., subscriber list) and no return signal may be required for the user to receive the media content. Users who purchase the service 300 or are enabled to receive the service may then get the feed and may watch in real time of rewind and replay events 400 . Users who do not elect to purchase the service 310 or are not enable to receive the service will not be able to view the content 410 .
[0084] While the preferred embodiment and various alternative embodiments of the invention have been disclosed and described in detail herein, it may be apparent to those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope thereof.
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A system and technique is described to enhance the use of limited bandwidth by intelligent broadcast, which would allow many more users to access content that was broadcast or downloaded by another user or group of users. While many users may download content that is specific to them, e.g., a flight itinerary, other users download the exact same content, e.g., a song or a movie, so the net result is that a significant portion of finite bandwidth is used repeatedly to download the same content. Furthermore, users, based on the type of user, or profiled users, will download the same content in the same general time period, for example, the release of a popular new album, movie or video. Content providers and wireless providers, who may be the same or different entities, may then share in the benefits of this approach, e.g., the savings in bandwidth usage and the improved distribution to the end user.
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BACKGROUND OF THE INVENTION
Washing machines or cleaning machines using water or dry cleaning fluid have been constructed in a number of different forms, and U.S. Pat. No. 2,931,505 illustrates a type of construction often used in commercial laundry equipment with a horizontal axis, rotating perforated container, and a vertical front loading door. U.S. Pat. No. 2,575,673 illustrates a similar type of cleaning machine which is capable of end discharging the washed clothing by tilting upwardly the rear of the machine about ten degrees. U.S. Pat. Nos. 4,534,188 and 4,535,610 illustrate a home laundry type of washing machine which has a vertical axis rotatable perforated basket and a top loading hatch which is accessible by tilting the washing machine forwardly about thirty degrees.
All such machines give little thought to the accessibility of the machine parts for servicing. In a commercial laundry setup with a long row of side-by-side washing machines, the servicing of the drive mechanism at the rear of the horizontal axis rotating perforated tubs is extremely difficult. Similarly, with a stackable unit with a dryer stacked on top of the washing machine, or with an undercounter washing machine, the servicing of the drive mechanism is quite difficult.
SUMMARY OF THE INVENTION
The problem to be solved, therefore, is how to provide easier access to the drive mechanism of a cleaning machine.
This problem is solved by a front loading cleaning machine comprising, in combination, a base adapted to be stationary, a cleaning machine unit having a watertight outer container, a perforated container within said outer container, means journaling said perforated container in said outer container, a front loading door on said outer container providing access to the interior of said perforated container, a drive mechanism including an electric motor and a drive connection from said motor to rotate said perforated container, and a pivot connection between said base and said cleaning machine unit along a horizontal pivot line parallel to the front door of said unit, whereby said unit may be tipped from a substantially vertical position of said front door forwardly to a substantially horizontal position of said front door to thus expose said drive mechanism on an upper portion of said unit.
Accordingly, an object of the invention is to provide a front loading cleaning machine which may be tipped forwardly to expose the drive mechanism.
Another object of the invention is to provide a front loading cleaning machine which has a drive mechanism at the rear and which machine may be tipped forwardly to have the drive mechanism at the upper portion of the machine for easy service.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a cleaning machine embodying the invention;
FIG. 2 is a similar side elevational view with the machine tipped forwardly to a servicing position;
FIG. 3 is a rear elevational view of the machine;
FIG. 4 is a front elevational view of the machine;
FIG. 5 is an enlarged, sectional view on line 5--5 of FIG. 1;
FIG. 6 is an enlarged, sectional view on line 6--6 of FIG. 1;
FIG. 7 is an enlarged, sectional view on line 7--7 of FIG. 1;
FIG. 8 is an enlarged, sectional view on line 8--8 of FIG. 3; and
FIG. 9 is a more detailed rear elevational view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1, 2, 3, and 4 generally illustrate a front loading cleaning machine 12 which may be used with water as a washing machine or with dry cleaning fluid as a dry cleaning machine. The machine 12 includes a base 13 which is adapted to be mounted stationarily on a support such as a floor 14. An optional cabinet 15 is shown in FIGS. 1 and 2 as one example of an enclosure which may be used with the washing machine 12. This cabinet has an open front to disclose the front of the machine 12.
A cleaning machine unit 18 is mounted on said base 13 by means of pivots 19 and 20 which are disposed along a horizontal pivot line parallel to the front of the machine 12. This cleaning machine unit 18 is shown upright in FIG. 1 in the operative position, and is shown tipped forwardly about 90 degrees in FIG. 2 to a servicing position.
The cleaning machine unit includes a rear plate 23, a front plate 24, and an outer container 25 therebetween. A front door 26, FIG. 4, is hinged to the front plate 24 and, when closed, is made watertight to provide watertightness to the outer container. The opening of the front door 26 provides access to the interior for loading clothing and the like to be washed. The outer container may be one of a number of shapes, e.g., octagonal, but is shown as cylindrical.
A perforated container 29, FIG. 5, is contained within the outer container 25. Journal means 30 is provided to journal the perforated container within the outer container 25, and this journal means includes a stub shaft 31 fixed to the rear of the perforated container 29 and a bearing housing 30 fixed to the rear plate 23. A shaft seal 33 is used to maintain separation of the bearings from the cleaning fluid in the washing machine unit.
In FIG. 6, the base 13 has an upright frame 36 to which a nut 37 is secured, as by welding. A shoulder bolt 38 passes through an aperture in a bracket 39 on the cleaning machine unit and is threaded into the nut 37 to form the pivot 19. Pivot 30, FIG. 4, has a similar but reversed construction. FIG. 7 shows a removable bolt 43 which may be threaded into a nut 44 secured to the frame 36. The bolt 43 passes through the bracket 39 secured on the cleaning machine unit 18 and through bracket 45 secured to the base 13, and into nut 44. A similar bolt 43 is provided near the front on the opposite side. Removable bolts 46, one on each side at the rear, secure the machine unit 18 to the frame 13. With these bolts 43 and 46 in place, the cleaning machine unit 18 is locked in the position shown in FIG. 1, and with removal of these bolts 43 and 46, the cleaning machine unit may be tipped forwardly to the position shown in FIG. 2.
A drive mechanism 50, FIG. 2, is provided for the cleaning machine 12, and includes an electric motor 51, a drive pulley 52 on the motor, and a belt 53 to a driven pulley 54 fixed to the stub shaft 31. The motor is mounted in a position conveniently in the lower end of the cabinet to provide a lower center of gravity CG to the cleaning machine unit 18. In this preferred embodiment, the motor 51 is secured by a bracket 55 to the rear plate 23. The center of gravity 60, FIG. 1, of the perforated container 29 is along a centerline of the shaft 31, and hence is above and forward of the pivots 19 and 20. When the perforated container contains wet clothing, for example, then the combined center of gravity moves downwardly but still remains forward and above the pivots 19 and 20. The motor 51 may be a two-speed motor, with a lower speed for washing or cleaning and a higher speed for centrifugally extracting liquid through the perforated container 29 to the outer container 25 and out through a drain 57, FIG. 3. Also, the motor 51 may be a reversible motor to rotate in a first direction for a short time and then rotate in the opposite direction for a similar time period for washing. The rear plate 23 is also provided with an overflow 58 and an air vent 59 to vent air for filling of the outer container.
A value housing 62, FIGS. 1 and 9, is secured to the rear plate 23 and, in the preferred embodiment, is in the top thereof. This valve housing includes a hot water fill valve 63 and a cold water fill valve 64, each of which may be solenoid-operated. The fill valves 63 and 64 control fluid inlet through flexible hoses 65 and 66 to the fill valves 63 and 64, and thence into the outer container 25. A solenoid-actuated drain valve 67 controls actuation of the drain 57 through a flexible drain hose 68 to a suitable drain, such as a sewer connection. A quick-release clamp 69 connects the flexible drain hose 68 to the drain 57. The overflow 58, FIG. 3, is also connected to this same sewer connection by a conduit 70.
A diaphragm switch 71, FIG. 9, is mounted on the valve housing 62, and is controlled by a water level conduit 72 connected to the lower end of the outer container 25.
An access door 73 is hinged to the lower edge of the front of the base 13 and may be closed, as shown in FIG. 1, or opened, as shown in FIG. 2. When opened, it opens an interlock switch 74. Also, when opened, this gives access to a quick-disconnect connection 75 in a flexible cable 76 supplying power to the motor 51. A control unit 78 may be mounted in a convenient location for control of the cleaning machine 12. This may be a coin-operated unit if the cleaning machine is to be used in a commercial laundry or in an apartment house, for example, or merely may be a timer or electrical controls where used in a home laundry. The control unit 78 may be mounted in any number of conveniently accessible locations. FIG. 1 shows the control unit mounted just to the rear of an upper panel 79 of the cabinet 15, or an alternate location is shown in FIG. 4 which is mounted on the front plate 24 on either side of the outer container 25. Also, such control unit may be mounted on the inside of the access door 73, especially in home laundry units.
OPERATION
The control unit 78 may be actuated to start operation of the cleaning machine 12 in a usual manner. Where the cleaning machine is used as a washing machine, the fill valves 63 and 64 will cause filling of the outer container to a suitable depth, and then of the perforated container 29 for short time periods in alternate directions. After the washing cycle has been completed, the drain valve 67 will be actuated to drain the outer container and the motor will go into high speed for centrifugally extracting the liquid. The present invention provides front servicing for this cleaning machine 12, which is highly advantageous where the cleaning machine is one of a row of such machines in a commercial laundry or is an undercounter unit or the lower unit of a stacked unit. In all such cases, access to the drive mechanism 50 would be quite difficult except for the present invention. For servicing, the access door 73 may be opened to the position shown in FIG. 2, and the four removable bolts 43 and 46 are quite accessible for removal by a wrench. With these removed, the cleaning machine unit 18 is still in a stable condition because the center of gravity CG is to the rear of the pivots 19 and 20. The opening of the access door 73 opens the interlock switch 74, which may be connected to de-energize all of the electrical power inside the cleaning machine 12, so that it may be safely worked on by the serviceman. This serviceman may reach through the access door 73 to disconnect the electric plug to the motor 51 at the connection 75, in case the flexible cable 76 is not long enough to permit tipping to the FIG. 2 position. If it is long enough, then this disconnection need not be made. The serviceman may also reach through the access door 73 to actuate the quick-release clamp 69 to disconnect the flexible drain hose 68 from the conduit 70. The flexible hoses 65 and 66 are long enough and have enough slack to permit tipping of the cleaning machine unit 18 from the position of FIG. 1 to the servicing position of FIG. 2. In this position, the center of gravity CG of the cleaning machine unit has rotated about 90 degrees from a position above and to the rear of the pivots 19, 20 to a position forward and above the pivots 19,20. This makes the cleaning machine unit 18 again in a stable condition so that it may be serviced without fear of flipping back to the FIG. 1 position. In this FIG. 2 position, the drive mechanism 50 is on the upper portion of the cleaning machine unit 18, so that the motor 51 may be serviced or replaced if necessary, the bearings 32 lubricated if such is required, or the belt 53 replaced. Alternatively, the motor 51 may be removed or replaced while the unit is in the upright position of FIG. 1, through the access door 73. This is still front service of the machine 12. Also, the journal means 30 is readily exposed on the upper side of the rear plate 23 should this need to be rebuilt or serviced in any manner.
The change in position from FIG. 1 to FIG. 2 shows that the cleaning machine 12 is one which is readily operable in a normal manner for cleaning clothes or washing clothes and the like, yet may be tipped from a substantially vertical position of the front door to a substantially horizontal position of the front door, to thus expose the drive mechanism on the rear plate to a forward and upper position of the unit for servicing.
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.
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A front loading cleaning machine may be operated in a normal manner by opening the front door and loading clothes to be washed. When servicing is required, the entire unit may be tipped forwardly about 90 degrees so that the front door is next to the floor. This makes the rear of the machine unit uppermost and exposes the drive mechanism mounted thereon. The drive mechanism may then be readily serviced because the mechanically moving parts are exposed on the upper portion of this machine unit. After servicing, the machine may readily be tipped back to its upright position, ready for normal operation. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 08/419,609, fled Apr. 10, 1995, and a continuation-in-part of International Patent Application No. PCT/EP96/01334, filed Mar. 27, 1996 and designating the United States. Both of said earlier applications are incorporated by reference herein in their entireties and relied upon.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to methods of attracting and combatting insects at a locus at which a crop is growing, especially a plantation crop, or at a locus where the presence of insects is undesirable for public health reasons.
2. Description of the Related Art
Many insecticidally active compounds are known, such as the insecticidal pyrazoles described in International Patent Publications No. WO 87/03781, WO 93/06089 and WO 94/21606, as well as in European Patent Publications No. 0295117, 0403300, 0385809, 0500209 and 0679650, German Patent Publication No. 19511269 and U.S. Pat. Nos. 5,232,940, 5,236,938 and 5,306,694, all of which are incorporated by reference herein in their entireties and relied upon, in particular for their descriptions of compounds of formulas (I) and (Ia) set forth hereinafter, generally and specifically, and for their descriptions of processes for the preparation and insecticidal use of such compounds.
A particular problem connected with the control of nuisance insects, especially the insects which are found to inhabit private or public housing or buildings, is that it is difficult to reach and treat all of the insects and it is most desirable to have a method to eliminate the population of insects, especially those insects which are not accessible to the treatment or have remained untreated for any reason.
An additional obstacle in eliminating or reducing a population of nuisance insects is that said insects are often able to detect the presence of insecticidally active ingredients, said ingredients thus acting as a repellent or anti-feeding agent for the insects.
Up until now, a common method for controlling a large population of insects, especially those inaccessible to direct treatment, is to utilize a program of multiple treatments or multiple placement of baits containing insecticidally active ingredients, or to associate attractants with insecticidally active ingredients.
OBJECTS AND SUMMARY OF THE INVENTION
An object of the instant invention is to provide a simplified and efficient method of controlling or combatting insects.
Another object of the instant invention is to provide a simplified and efficient method of controlling or combatting insects whereby an attractive ingredient, that is, an attractant, is presented to the insects.
An especially advantageous object of the instant invention is to provide a simplified and efficient method of controlling or combatting insects whereby an attractant is presented to the insects, said attractant being simultaneously insecticidally active.
The present invention thus provides a new use, as an attractant for insects, of a compound having the formula: ##STR2## wherein: R 1 is CN or methyl;
R 2 is S(O) n R 3 ;
R 3 is alkyl or haloalkyl;
R 4 is hydrogen, halogen, --NR 5 R 6 , --S(O) m R 7 , alkyl, haloalkyl, --OR 8 or --N=C(R 9 )(R 10 );
each of R 5 and R 6 , which are the same or different, is hydrogen, alkyl, haloalkyl, --C(O)alkyl or --S(O) r CF 3 ;or R 5 and R 6 together a divalent lower alkylene radical which is optionally interrupted by one or more heteroatoms (O, S or N);
R 7 is alkyl or haloalkyl;
R 8 is alkyl, haloalkyl or hydrogen;
R 9 is hydrogen or alkyl;
R 10 is phenyl or heteroaryl, each of which is unsubstituted or is substituted with one or more substituents selected from the group consisting of hydroxy, halogen, --O--alkyl, --S--alkyl, cyano and alkyl;
each of R 11 and R 12 , which are the same or different, is halogen or hydrogen;
R 13 is halogen, haloalkyl, haloalkoxy, --S(O) q CF 3 or --SF 5 ;
each of m, n, q and r, which are the same or different, is 0, 1 or 2; and
X is nitrogen or C--R 12 ;
provided that when R 1 is methyl, R 3 is haloalkyl, R 4 is NH 2 , R 11 is Cl, R 13 is CF 3 and X is N.
In one particular aspect, the present invention provides a new use, as an attractant for insects, of a compound having the formula: ##STR3## wherein: R 14 is alkyl or haloalkyl;
R 15 is alkyl, haloalkyl, amino, alkylamino or dialkylamino;
each of R 16 and R 17 , which are the same or different, is hydrogen or halogen, at least one of them preferably being other than hydrogen;
R 18 is halogen, haloalkyl, haloalkoxy or SF 5 ; and
n is 0, 1 or2.
In another aspect, the present invention provides a method for attracting insects, said method comprising offering to said insects for ingestion an effective attractant amount of a compound of formula (I) or (Ia) as defined above.
In yet another aspect, the present invention provides a method for attracting and killing insects comprising offering to said insects for ingestion a compound of formula (I) or (Ia) as defined above in an amount which is effective both as an attractant and as an insecticide.
DETAILED DESCRIPTION OF THE INVENTION
In the present description, the following definitions are applicable:
The alkyl radicals and the alkyl portions of other radicals (e.g. the haloalkyl, haloalkoxy, alkylamino and dialkylamino radicals) can have up to six carbon atoms but are preferably lower alkyl, that is to say, they preferably each have one to four carbon atoms. In the case of the dialkylamino radicals, the alkyl portions can be the same or different. The alkyl radicals and alkyl portions of other radicals can be straight- or branched-chain. The halogen atoms can be fluorine, chlorine, bromine or iodine, preferably fluorine or chlorine.
When R 5 and R 6 in formula (I) together form a divalent lower alkylene (C 3 -C 7 ) radical optionally interrupted by one or more heteroatoms, --NR 5 R 6 preferably represents piperidino, piperazinyl, morpholino, thiomorpholino, pyrrolidino or hexamethyleneimino, each of which is optionally substituted with one or more lower alkyl groups.
When R 10 in formula (I) is heteroaryl, it is preferably pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, thiazolyl, benzothienyl, benzofuryl, quinolyl, isoquinolyl, benzothiazolyl or methylenedioxyphenyl, each of which is optionally substituted as indicated with the definition of R 10 hereinabove.
A preferred group of compounds of formula (I) for use herein are those in which:
R 1 is CN; and/or
R 3 is haloalkyl; and/or
R 4 is NH 2 ; and/or
each of R 11 and R 12 , which are the same or different, is halogen; and/or
R 13 is haloalkyl.
Preferred compounds of formula (Ia) for use in accord with the present invention are compounds in which each of R 16 and R 17 is a halogen atom, R 18 is a haloalkyl radical, R 14 is a lower haloalkyl radical and R 15 is an amino radical.
Especially preferred for use in accord with the present invention is the insecticide known as fipronil, whose chemical name is 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethyl)phenyl-4-trifluoromethylsulfinylpyrazole, and which is specifically described in the aforementioned EP 0295117 and Hatton et al U.S. Pat. No. 5,232,940.
The preparation of compounds of formula (I), such as the compounds of formula (Ia), for use herein can proceed according to any process described in the hereinabove-cited patent documents, or other process within the knowledge of one skilled in the art of chemical synthesis.
According to a further aspect of the invention, there is provided a method for controlling a population of insects, especially insects able to walk or travel in public or private housing or building or household or home, that is, insects which are able to enter or inhabit buildings, whereby an attractant and insecticidally effective mount of a compound of formula (I) as defined above, such as a compound of formula (Ia), is offered or presented to the insects to be controlled as food among alternative food or foods, which can be closely situated.
The method of the invention is especially advantageous because it provides more possibilities and much more freedom for placement of the insecticidally active ingredient. Because of its attractant properties, the insecticidally active ingredient can be located in any place, not only at the specifically appropriate place where the insects are to travel and feed.
In a preferred embodiment of the present invention, there is provided a method for controlling a population of insects at a locus which is in or near a food storage, preparation, serving or eating area, said method comprising offering to said insects as an alternative food source an mount of a compound of formula (I) as defined above, such as a compound of formula (Ia), which is effective both as an attractant and as an insecticide. Thus, an effective attractant and insecticidal mount of a compound of formula (I), such as a compound of formula (Ia), is preferably offered to the insects in or near an area in which other food is present as a practical consequence of the normal use of the building or housing.
The active ingredient of formula (I)/(Ia) is preferably used in accord with the present invention in the form of a bait, which can be a solid, liquid or gel bait. The manner of preparation of a bait will be apparent to one of ordinary skill in the art. Baits have already been described in the patent documents cited hereinabove. It is of course not necessary to add an attractant to the active ingredient of formula (I)/(Ia) and the carrier or diluent to form the bait, since the compound of formula (I)/(Ia) acts herein as an attractant as well as an insecticide.
The method of the invention is particularly appropriate as a method for the control of populations of insects like cockroaches, ants or the like, especially those belonging to the families Blatidae and Formacidae. Treatment of cockroaches in an area in which their presence can be detrimental to public health, that is to say in housing or buildings, is a preferred feature of the instant invention, especially for the control of so-called American cockroaches (Periplaneta americana), but also of other cockroaches such as German cockroaches (Blatella germanica).
The attractant compositions or baits which can be used in the practice of the present invention can be offered or presented to the insects in various amounts. Usually, however, it is advantageous to offer these attractant compositions or baits comprising the compound of formula (I)/(Ia) in an appropriate form and in an amount of from about 0.00001 g to about 20 g of active ingredient of formula (I)/(Ia) per 100 square meters, preferably of from about 0.001 g to about 1 g per 100 m 2 .
The attractant compositions which are useful in the present invention generally comprise from about 0.0001 to about 15 % w/w of active ingredient of formula (I)/(Ia), preferably from about 0.01 to about 6 % w/w. These compositions can be in the form of a solid, e.g. dusts or granules or wettable powders, or in the form of a liquid, such as an emulsifiable concentrate or a true solution.
The attractant compositions can also contain any compatible surface-active agent and/or carrier, preferably selected from ingredients which can be eaten by insects. The carrier itself can be solid or liquid.
The compounds of formula (I)/(Ia) can be used in sequence or admixture, particularly in admixtures with another pesticide, for example, an insecticide, acaricide or fungicide.
The attractant compositions can be prepared by simply admixing the ingredients.
The invention is illustrated by the following examples which should not be considered as limiting or restricting the invention.
EXAMPLES
On a large circle situated on a 1 square meter confinement, various foodstuffs and two baits of fipronil were distributed around the perimeter of a circle of 75 cm diameter. Similar pieces of baits were placed at diametrically opposed points on the circle.
Adults cockroaches (25 males and 25 females) were released and offered harborage 24 hours prior to the start of the experiment. All testing was conducted at night under infrared illumination. Three replicates were conducted for each species. Observations began one hour after lighting in the laboratory went off. The number of foraging cockroaches at each location was recorded at 10 minute intervals for a period of 120 minutes.
Example 1
Only fipronil was used as an insecticide.
The alternative foods were: 2 pieces of rodent chow, 2 pieces of rodent jelly and 2 vials of water.
The numbers of foraging German cockroaches for up to 3 hours of foraging time were measured and cumulatively added.
62 cockroaches went to fipronil, 43 to chow, 25 to jelly and 22 to water.
Example 2
Only fipronil was used as an insecticide.
The alternative foods were: 2 pieces of rodent chow, 2 vials of oil and 2 vials of water.
The numbers of foraging German cockroaches for up to 3 hours of foraging time were measured and cumulatively added.
68 cockroaches went to fipronil, 25 to chow, 23 to oil and 14 to water.
Example 3
One insecticidal bait comprised fipronil and one comprised hydramethylnon.
The alternative foods were: 2 pieces of rodent chow, 2 pieces of rodent jelly, 2 vials of water and 1 piece of hydramethylnon.
The numbers of foraging American cockroaches for up to 3 hours of foraging time were measured and cumulatively added.
35 cockroaches went to fipronil (substantially less to the other insecticide), 17 to chow, 15 to jelly and 18 to water.
While the invention has been described in terms of various preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions and changes can be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims, including equivalents thereof.
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A method for attracting and controlling insects comprising offering to said insects for ingestion an effective amount of a compound of the formula: ##STR1## wherein the structural variables are as defined in the specification.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of Ser. No. 11/203,017, filed Aug. 11, 2005 now abandoned, entitled “Treatment of High Sulfate Containing Quicklime,” by inventor, Fred R. Huege.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the production of commercial quicklime and its end products and specifically to a process for controlling the presence of soluble sulfate ions during the slaking of quicklime which would otherwise lead to undesirable agglomeration of the fine calcium hydroxide particles produced.
2. Description of the Prior Art
Lime, in its different forms, has a variety of uses. It is commonly used in treating waste water and sewage. It is used in agriculture to neutralize acidic soils and to provide nutrients for sustaining plant life. Lime is also used extensively in construction for the stabilization of soils and as a component in a variety of building materials. These are but a few of the many uses of this versatile material.
The general term “lime” is often used interchangeably to mean both quicklime (calcium oxide) and hydrated lime (calcium hydroxide). Quicklime is produced by heating limestone (calcium carbonate) in a kiln at extreme temperatures to “calcine” the material and thereby drive off carbon dioxide. Quicklime is usually in the form of lumps or pebbles. In order to further process lime and improve the ease with which it is handled, quicklime is often contacted or mixed with water. The water reacts with the quicklime in an exothermic reaction to form hydrated lime. This is often referred to as “slaking.” During the slaking of quicklime, large amounts of heat are given off which can significantly raise the temperature of the slurry. Water can then be driven off to produce dry, hydrated lime which is usually a powder. Technically, the terms “hydration” and “slaking” are synonymous and interchangeable. However, according to popular usage of these terms, hydration yields a dry powdered hydrate, whereas slaking involves more water, producing wet hydrates, sometimes referred to as putties, slurries, milk of lime and lime water, depending upon the amount of excess water they contain.
It is well established that sulfur in the form of sulfates is a undesired impurity in commercial quicklime. For example, the sulfur is detrimental for the use of quicklime in the steel industry because one of its applications is to remove sulfur during the flux operation of purifying iron into steel. The presence of sulfur in any form is detrimental in this market.
In other markets where quicklime is slaked to produce a milk of lime or lime slurry, the presence of sulfate ions in the quicklime causes an agglomeration reaction during the slaking process which causes the fine particles of calcium hydroxide to stick together and thus settle out of suspension.
In some instances in the past, sulfate ions have actually been intentionally introduced into the lime slaking operation. For example, well-established technology exists which involves the addition of gypsum or sulfate ions to quicklime during the slaking operation to increase the solids content of lime slurry in a controlled manner. U.S. Pat. No. 4,464,353, issued Aug. 7, 1984, to Norman L. Hains teaches that, in the production of a lime slurry, the timely addition of sulfate compounds, preferably calcium sulfate, to the aqueous slaking medium prior to the introduction of calcium oxide (quicklime) retards the chemical reaction of the calcium oxide with the aqueous slaking medium, thereby forming a lime slurry having decreased solubility and increased particle agglomeration. According to the teaching of that patent, the described process affects the physical properties of the lime slurry formed by allowing the formation of larger crystals of calcium hydroxide, thus increasing the average particle size by agglomeration.
Despite the advantages obtained through the addition of sulfate ions during the slaking operation under the controlled conditions described above, it is known that the presence of excess sulfate ions will cause an unstable lime slurry which will settle out in storage tanks and in transport vehicles.
In many instances, it is therefore desirable to limit the presence or availability of free sulfate ions during the quicklime slaking operation.
An opposing consideration for the lime manufacturer, however, is the fact that there is an advantage in the production of quicklime to increase the sulfur content in the product. This results from the fact that the higher sulfur content fuels used in the step of calcining the limestone to form quicklime are less expensive then lower sulfur content fuels. Thus, the manufacturers of quicklime would like to use as high a sulfur fuel as possible, balancing the sulfur content in the quicklime and operational conditions in the kiln.
The quality and type of fuel exert a dramatic effect on the quality of lime produced. The major fuel sources at the present time include solid fuels, such as bituminous coal, anthracite coal, coke and producer gas, natural gas and fuel oil. While sulfur exists in limestone homogeneously as calcium sulfate or heterogeneously in the mineral pyrite in amounts of about 0.01 to 0.12%, the calcining fuel generally introduces more sulfur into the calcination process than does the limestone feed, natural gases being the exception. For example, coal used for lime manufacture typically contains 0.5-3.5% and fuel oils contain nearly as much.
There exists a need, therefore, for a process which would allow the use of higher sulfur content fuels in the step of calcining the limestone to form quicklime which would, at the same time, control the presence of soluble sulfate ions during the slaking of quicklime which would otherwise lead to undesirable agglomeration of the calcium hydroxide particles produced.
A need also exists for such a process which would allow the use of solid fuel sources in the calciner, such as coal, rather than requiring the use of more expensive natural gas as a fuel source.
A need exists for such a process which would be easily implemented as a part of the slaking operation without requiring drastic changes in operational procedures or equipment.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a treatment method for high sulfate containing quicklimes which allows the use of typical solid fuels to fuel the calciner, rather than requiring the use of more expensive natural gas as a calciner fuel, and yet which controls the presence of soluble sulfates during the slaking operation.
The presence of soluble sulfate ions during the slaking of quicklime causes an undesirable agglomeration of the fine calcium hydroxide particles by an unknown mechanism. The higher the sulfur/sulfate concentration in the quicklime the more dramatic the agglomeration of the calcium hydroxide particles and the lower the commercial value of the quicklime and the more limited its market.
It has been discovered that the sulfate ions can be de-activated and thus controlled during the slaking operation through the mechanism of the present invention. As a result, they do not cause the undesirable agglomeration of the calcium hydroxide particles discussed above. This de-activation is achieved by having the sulfate ions precipitated or complexed prior to the onset of the quicklime slaking reaction. Once precipitated or “tied up” the soluble sulfate ions no longer enter into the slaking reaction even if they are still present during slaking.
Preferably, the soluble sulfate ions are tied up by artificially inducing the formation of an additional reaction product, complex or precipitant, during the slaking operation, for example, ettringite or the like. Ettringite, a complex mineral composed of calcium alumina sulfate, Ca 6 Al 2 (SO 4 ) 3 (OH) 12 .26(H 2 O), forms under alkaline conditions with the proper concentrations of calcium, aluminum and sulfate ions being present. The presence of aluminum ions can be achieved by the addition of an aluminum ion donor composition, such as sodium aluminate. The sodium aluminate can be added to the slaking water or to the quicklime. Preferably, it is first dissolved in the slaking water prior to adding the quicklime.
In its most preferred aspect, the present invention is therefore a method of slaking high sulfate containing quicklime to form fine particles of calcium hydroxide. The method first involves the step of providing a source of quicklime and a source of slaking water. Next, a complexing agent is mixed with the quicklime or with the slaking water, the complexing agent being effective to complex with and tie up available soluble sulfate ions present in the quicklime upon addition of the quicklime to the slaking water. As a result, the undesirable agglomeration of fine particles of calcium hydroxide is prevented.
Additional objects, features and advantages will be apparent in the written description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of particle size distribution of lime milk based on high-sulfur quicklime (QL reference) compared with lime milk according to the present invention prepared from the same QL but with various additions.
FIG. 2 is a graph of cumulative particle size of lime milk based on high-sulfur quicklime (QL reference) compared with lime milk prepared according to the present invention from the same QL but with various additions.
DETAILED DESCRIPTION OF THE INVENTION
In the discussion which follows, the term “quicklime” will be taken to mean calcium oxide and should not be confused with limestone (calcium carbonate). As briefly outlined in Applicant's background discussion, quicklime is manufactured from limestone by heating to remove carbon dioxide. Quicklime can be converted to Ca(OH) 2 by a slaking process where water and CaO are mixed under agitation to produce Ca(OH) 2 , known in the industry as slaked lime or lime hydrate.
In the typical prior art process for producing industrial grade hydrated lime, raw limestone is first fed to a calciner which is typically a horizontal or vertical kiln. The kiln is fired by burners which typically utilize pulverized coal as a fuel and are capable of reaching calcining temperatures in excess of 1600° F. The intense heat causes a chemical reaction as follows:
CaCO 3 +heat=CaO(quicklime)+CO 2
The quicklime produced in the calciner is then slaked by mixing with an aqueous slaking medium in hydrator. This results in an exothermic reaction generating heat and calcium hydroxide:
CaO+H 2 O=Ca(OH) 2 +heat
The size and quality of slaked lime particles in the resulting slurry are dependent on a number of variables. These include the reactivity, particle size and gradation of the quicklime used. Other variables include the amount of water used, the quality of the water, and the amount and type of water impurities. Further, the temperature of the water and the amount of agitation can affect slaked lime quality and particle size.
The presence of sulfur in the quicklime, particularly in the form of soluble sulfate ions is undesirable. As discussed in the Background section above, it has been discovered that the undesirable sulfate ions can be de-activated and thus controlled during the slaking operation through the mechanism of the present invention, thus not causing the undesirable agglomeration of the calcium hydroxide particles. This de-activation is achieved by having the sulfate ions precipitated, complexed, reacted or otherwise interacted in a specific predetermined fashion prior to the onset of the quicklime slaking reaction. In the present discussion, the various mechanisms of “complexing,” “reacting” or “precipitating” may all be referred to collectively by the team “complexing” for simplicity. By whatever mechanism, once precipitated, complexed or “tied up” the soluble sulfate ions no longer enter into the slaking reaction even if they are still present during the slaking reaction. In other words, the act of complexing the soluble sulfate ions hinders their ability to compete in the slaking reaction with the other free ions present. In using the term “sulfate” Applicant intends in this discussion to encompass sulfur in whatever form it may be present in the quicklime being slaked. Most commonly, this will be in the form of soluble sulfate ions.
The solubility of sulfate salts varies significantly depending upon the cation present. As shown below, most sulfate salts are soluble with the exception of barium sulfate, which has a very low solubility.
Sulfate Solubility
Cation
KSP
gm/100 gm water
Calcium
2.0E-04
0.2
Strontium
3.8E-07
0.01
Barium
1.1E-10
0.0002
Lead
1.0E-08
0.004
Ettringite*
0.0001
*Estimated sulfate solubility
The test results which are reported in the discussion which follows show the effectiveness of barium in removing the sulfate ions which would otherwise have a detrimental effect on the slaking reaction. Unfortunately barium is considered a heavy metal with certain health and environmental limitations. Thus while the use of barium may be a technical solution, it is not seen as being a commercially viable option. Strontium is a more benign chemical, but is has higher sulfate ion solubility compared to barium. Thus it is less effective in decreasing the detrimental sulfate agglomeration.
Applicant's preferred solution for complexing the soluble sulfate ions is to create conditions conducive to the formation of a complex such as the mineral ettringite, or the like. Ettringite is a complex mineral composed of calcium alumina sulfate, Ca 6 Al 2 (SO 4 ) 3 (OH) 12 .26(H 2 O). Ettringite is very insoluble in water once it is formed. Ettringite does not contain any heavy metals or toxic elements. If ettringite is formed under the conditions present during the slaking of quicklime it will complex the sulfate ions, thus reducing their agglomeration effect on the calcium hydroxide particles.
Ettringite forms under alkaline conditions with the proper concentrations of calcium, aluminum, and sulfate ions being present. The data contained in the Tables which follow shows the effectiveness of adding sodium aluminate to complex the soluble sulfates ions in a slaking operation, thus preventing calcium hydroxide particle agglomeration. Initially calcium chloride was also added with the sodium aluminate to have a soluble source of calcium ions immediately available for the ettringite formation, but it was later shown not to be necessary in that the slaking calcium oxide provided the necessary calcium ions for the ettringite formation. The sodium aluminate can be added to the slaking water or to the quicklime, although it appears to be more effective when first dissolved in the slaking water prior to adding the quicklime.
It will be appreciated that, rather than attempting to de-agglomerate the calcium hydroxide particles after the slaking reaction, Applicant proposes to prevent the agglomeration from occurring in the first place by removing (complexing) the offending sulfate ions, thus preventing undesirable agglomeration during the quicklime slaking reaction. To test the validity of the complexing hypothesis, initial tests were run with the addition of barium ions into the slaking reaction to form the insoluble barium sulfate precipitate. As discussed above, the use of barium ions is unlikely to be a commercially acceptable additive, but it is an appropriate material for concept evaluation.
The results in Table 1 below show a dramatic decrease in +100 mesh (150 micron) residue with the addition of barium ions to precipitate the soluble sulfate ions. In addition to reducing the agglomeration, the precipitation of the soluble sulfate ions also decreased the average particle size and increased the viscosity of the slaked lime slurry. In these tests, and the tests which follow, gypsum was added to the quicklime slaking water to simulate the addition of sulfate ions from a high sulfur fuel.
TABLE 1
100 gm of QL +
100 gm of QL +
0.5% gypsum added
1.0% gypsum added
100 gm of QL +
100 gm of QL +
to QL, slaked with
to QL, slaked with
Control, 100 gm
0.5% gypsum
1.0% gypsum
277 gm DI water
277 gm DI water
QL slaked with
added to QL,
added to QL,
with 1.0 gn of
with 2.0 gn of
277 gm of DI
slaked with 277 gm
slaked with 277 gm
barium hydroxide
barium hydroxide
water
DI water
DI water
added to the water
added to the water
Screen
Amount Retain on screen grams
20 mesh (0.85 mm)
1.67
1.12
2.49
0.55
1.10
40 mesh (0.425 mm)
0.82
1.72
4.32
1.54
0.90
100 mesh (150 microns)
4.14
12.55
20.56
4.57
2.45
Particle Size Distribution*
Median Diam, μm
2.93
4.23
6.36
1.71
1.85
Modal Diam, μm
2.40
2.40
22.26
1.06
0.99
*FW Lab-dried slurry from 100 pass sieve
To further validate the technology and determine commercial viability, additional tests were performed, the results of which are given in Table 2 below. These results show that it was in fact the barium precipitation of the sulfate ions which achieved the desired result and not a pH effect caused by the barium hydroxide. Commercially important is the fact that the solid sulfate ion precipitation material can be added directly to the quicklime and still be effective.
TABLE 2
100 gm of QL + 1.0% gypsum
added to QL, slaked with
100 gm of QL + 1.0%
277 gm of DI water with
gypsum added to QL,
100 gm of QL + 1.0%
2.0 gm of barium hydroxide
slaked with 277 gm DI
gypsum and 1.0 gm
added to the water, the water
water with 1.0 gm of
barium hydroxide added
was then neutralized with HCl
sodium hydroxide added
to QL, slaked with 277 gm
Screen
to ph = 7
to the water
DI water
20 mesh (0.85 mm)
0.12
1.18
0.49
40 mesh
0.34
1.96
0.70
(0.425 mm)
100 mesh (150
2.57
14.13
4.71
microns)
Particle Size Dist.*
Median Diam, μm
2.46
6.01
2.80
Modal Diam, μm
1.37
23.96
1.96
*FW Lab-dried slurry from 100 pass sieve
Tables 3 and 4 which follow show additional test results which were obtained and which compare the use of sodium aluminate as an ettringite “promoter” with the addition of barium and strontium. The laboratory tests were run utilizing deionized water and 100 grams of quicklime obtained from a commercial lime kiln. The test results compare the addition of the above reactants both to the slaking water and, in some cases, after slaking. The addition of sodium aluminate can be seen to be effective as a complexing agent in removing the undesirable soluble sulfate ions from the reaction.
Although the tests shown in Tables 3 and 4 all use sodium aluminate as the ettringite promontory, it will be appreciated by those skilled in the art that other alumina donors could be utilized as well, for example, aluminum nitrate (Al[NO 3 ] 3 ), aluminum acetate (C 4 H 7 AlO 5 ) and L-lactic acid aluminum salt (C 9 H 15 AlO 2 ). The primary criteria for a candidate material is that it provide a supply of free alumina ions in aqueous solution.
Table 5 which follows as well as FIGS. 1 and 2 of the drawings, compare the effect of sodium aluminate as well as other aluminum ion donor when 150 g of a quicklime containing 0.4% by weight of sulfur is slaked in 600 g of water, without or with 0.5% additive by weight (0.75 g in 150 g of quicklime). The effect of all the additives on reducing the particle size distribution and the settling of the corresponding milk of lime appears clearly compared to the reference (control) without any additive.
TABLE 3
Date
May 27, 2005
12
15
14
7
8
9
13
Description
300 g DI H 2 O +
301 g DI H 2 O +
300 g DI H 2 O +
[300 g DI H 2 O +
[300 g DI H 2 O +
[300 g DI H 2 O +
[300 g DI H 2 O +
[100 g QL + 2 g
[100 g QL + 5 g
[100 g QL + 2 g
1 g Ba(OH) 2 ] +
2 g Sr(NO 3 ) 2 ] +
2 g Ba(OH) 2 ] +
4 g Sr(NO 3 ) 2 ] +
Gypsum +
Gypsum]
Gypsum]
[100 g QL + 1 g
[100 g QL + 1 g
[100 g QL + 1 g
[100 g QL + 1 g
4 g Al 2 O 3 Na 2 O]
Gypsum]
Gypsum]
Gypsum]
Gypsum]
Gypsum
2 gm
5 gm
2 gm
1 gm
1 gm
1 gm
1 gm
Additive
Ba(OH)2
1 gm
2 gm
Sr(OH)2
2 gm
4 gm
Na2Al2O3
4 gm to QL
3 gm
4 gm after slaking
CaCl2
Comments
very thick
very thick
Settled, thin. Added
think, but not
settled
thick
settled by slightly
4 g Al 2 O 3 Na 2 O
settling
thick
after slaking
% retained
Sieve sizes
+30
5%
3%
7%
3%
3%
2%
3%
+100
5%
7%
35%
10%
14%
4%
13%
+200
4%
5%
20%
6%
19%
5%
15%
−200 mesh
87%
85%
38%
81%
65%
89%
70%
TABLE 4
Date
May 26,
May 25,
May 26, 2005
May 25,
May 26, 2005
May 27, 2005
May 27, 2005
May 31, 2005
May 31, 2005
2005
2005
2005
1
2
5
5B
5A
10 (repeat of 6)
11
Description
300 g DI
300 g DI
300 g DI
300 g DI
[300 g DI
[300 g DI
[300 g DI
300 g DI
300 g DI
H 2 O +
H 2 O +
H 2 O +
H 2 O +
H 2 O + 1 g
H 2 O + 0.5 g
H 2 O + 1 g
H 2 O + [100
H 2 O +
100 g QL
100 g QL
[100 g QL +
100 g QL
Al 2 O 3 Na 2 O] +
Al 2 O 3 Na 2 O] +
Al 2 O 3
g QL + 2 g
[100 g QL +
1 g Gypsum]
[100 g QL +
[100 g QL +
Na 2 O] +
Gypsum + 1
2 g Gypsum +
1 g Gypsum]
2 g Gypsum]
[100 g QL +
g Al 2 O 3
2 g Al 2 O 3
2 g Gypsum]
Na 2 O]
Na 2 O]
Control
Gypsum
1 gm
1 gm
1 gm
1 gm
2 gm
2 gm
2 gm
2 gm
Additive
Ba(OH)2
Sr(OH)2
Na2Al2O3
0.8
1 gm
0.5 gm
1 gm
1 gm to QL
2 gm to QL
CaCl2
1 gm
Comments
non-
settled
settled
thick
thick
settled
thin
thick
settling
% retained
Sieve sizes
+30
2%
8%
5%
3%
4%
7%
3%
4%
3%
+100
8%
47%
27%
10%
7%
25%
10%
19%
5%
+200
9%
16%
21%
7%
4%
19%
8%
32%
5%
−200 mesh
82%
30%
48%
80%
84%
50%
79%
45%
88%
TABLE 5
{600 g DI H 2 O +
{600 g DI H 2 O +
{600 g DI H 2 O +
{600 g DI H 2 O +
{600 g DI H 2 O} +
0.75 g Na 2 Al 2 O 3 } +
0.75 g Al(NO 3 ) 3 } +
0.75 g C 4 H 7 AlO 5 } +
0.75 g C 9 H 15 AlO 2 } +
Description
150 QL
150 QL
150 QL
150 QL
150 QL
% S
0.4%
0.4%
0.4%
0.4%
0.4%
Additive
none
sodium aluminate
aluminum nitrate
aluminum acetate
lactic acid
aluminate
% additive
0
0.5%
0.5%
0.5%
0.5%
% retained
sieve sizes
+30
10%
0%
0%
0%
0%
+100
29%
0%
2%
5%
5%
+200
4%
5%
5%
5%
5%
−200 mesh
57%
95%
93%
90%
90%
settling rate
high
very low
low
low
low
An invention has been provided with several advantages. The technology of eliminating soluble sulfate ion induced agglomeration of high sulfur quicklime during quicklime slaking has been proven to be very effective. The inventive method produces an environmentally benign and economically sensible sulfate precipitating agent. The result will be to open the potential of more widespread acceptance of high sulfur quicklime into a number of different markets.
While the invention has been shown in several of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit thereof.
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A method is shown for controlling the presence of soluble sulfate ions in a lime slaking operation in which a source of quicklime is combined with slaking water to form calcium hydroxide product. A complexing agent is added to either the quicklime or the slaking water which is effective to tie up the soluble sulfate ions otherwise available in solution, whereby the agglomeration of calcium hydroxide product is acceptably controlled.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of U.S. Provisional Patent No. 60-464,894 issued on Apr. 21, 2003.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable
REFERENCE TO A “SEQUENCE LISTING”
[0003] Not applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates generally to protecting the heads of golf clubs from damage, and more specifically to the protection of a golf club head while in personal use (the act of hitting the ball).
[0006] 2. Description of the Related Art
[0007] Golf club head covers to protect the club while being transported in the bag have been in use for years. More recently golf shops have been attaching three pieces of tape to the top, bottom and face of a golf club for temporary protection of their inventory while on trial or demo.
[0008] The main problem with both club protection products is they do not address the need to protect the appearance and subsequently the lifetime value of the golf club during personal use, when the majority of the damage normally occurs to the club.
[0009] As stated above, conventional head covers are primarily intended to protect the clubs during transportation, and do no protect the club from damage that can occur as a result of a miss-hit while in the act of hitting the ball.
[0010] The problem with the protective tape product for trial or “demo” is that it is designed to protect the golf shop's inventory by wrapping nearly the entire head of the club. This gives the potential buyer a chance to try out the club without leaving any trace of use, and allows the reseller to sell the club to another buyer as new. As a result the tape is not intended for prolonged use. The other problem is that the tape is not tailored to fit the club closely. This fact, coupled with the type of tape used, make the use of this protection product very noticeable and alters the look of the club, which does not lend itself to personal use.
[0011] While these devices may be suitable for the particular purpose that they address, they are not as suitable for protection of a golf club during personal use.
[0012] In these respects, the protective guard according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of protecting of the appearance and the lifetime value of a golf club while in personal use.
SUMMARY OF THE INVENTION
[0013] How a golf club looks at address or at set up has always been important to golfers psychologically. Looking down on a golf club with noticeable sky marks or abrasions can be a constant reminder of shots that went bad and can have a negative effect. This fact, coupled with recent developments in the golf market, has led to the publishing of a “Blue Book” for used clubs. Much like in the automotive industry, the value of a club is primarily based on the type of club and its physical appearance. This has resulted in greater demand and a higher value for used clubs for trade or resale, and were all factors that led to the development of the Golf Club Protective Guard.
[0014] In view of the foregoing disadvantages inherent in the known types of golf club protective devises now present in the prior art, the present invention provides a new protective product that protects the lifetime value of a golf club while in personal use.
[0015] The general purpose of the invention, which will be described subsequently in greater detail, is to provide a new golf club protection product that has many of the advantages of the protection products mentioned above, and many novel features that result in a new golf club protection product that is not anticipated, rendered obvious, suggested, or even implied by any prior art, either alone or in any combination thereof.
[0016] To attain this purpose, the invention consists of a transparent abrasion resistant adhesive vinyl strip that preferably has a thickness in the range of 4 to 5 mil and acts as a deflective guard that is designed to fit the contours of the club and when attached provides a semi-permanent, almost invisible protective barrier against abrasions caused by miss-hits during the act of hitting the ball.
[0017] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter.
[0018] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.
[0019] A primary object of the present invention is to provide a protective guard that will overcome the shortcomings of the prior art devices.
[0020] An object of the present invention is to provide a protective guard to protect the appearance and subsequently the lifetime value of the club.
[0021] Another object is to provide a protective guard that is virtually invisible while protecting the Golf Club.
[0022] Another object is to provide a protective guard that is semi permanent, but can be removed from the club at any time or replaced with little or no adhesive residue.
[0023] Another object is to provide a protective guard that is economical and can be removed and replaced easily.
[0024] Another object is to provide a protective guard that is attachable to various sizes, styles and type of golf clubs.
[0025] Another object is to provide a protective guard that does not interfere with the normal operation of the club.
[0026] Another object is to provide a protective guard that is lightweight and does not affect the overall balance and performance of the club.
[0027] Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention.
[0028] To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0030] [0030]FIG. 1 is a perspective of a golf club head with the protective guard invention attached, and shows the components of both the protective guard and the golf club.
[0031] [0031]FIG. 2 is a diagram showing all of the components of a preferred embodiment of the protective guard that constitutes the invention.
[0032] [0032]FIG. 3 is a perspective of a golf club with the protective guard of FIG. 1 being fitted to the club.
[0033] [0033]FIG. 4 is a perspective of a golf club with the protective guard of FIG. 1 being lined up and attached to top edge of the club.
[0034] [0034]FIG. 5 is a perspective view of a golf club with the protective guard of FIG. 1 being attached to the face of the club.
[0035] [0035]FIG. 6 perspective view with the protective guard of FIG. 1 installed.
[0036] [0036]FIG. 7 is a perspective view of a similar golf club, illustrating the type of damage that the protective guard of FIG. 1 protects against.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Turning now to the drawings, in which similar reference characters denote similar elements throughout the several views, the attached figures illustrate the golf club protective guard, which consists of a transparent strip that is designed to fit the contours of a golf club, and that when properly attached, that strip provides an almost invisible protective barrier against abrasions caused by miss-hits.
[0038] [0038]FIG. 1 is a perspective view of the head of a golf club 10 with protective guard 11 attached. This view permits pointing out the common features of a golf club, and illustrates how guard 11 looks when attached to the head of the golf club 10 . The head of a golf club 10 is shown generally to include a top 12 and a face 13 , and the contoured edge along which top 12 and face 13 are disposed in a mutually facing relationship is referred to as top line 14 . The outward point at which top 12 , face 13 and top line 14 meet is the toe 15 , and the opposite end where shaft 16 attaches to the head of the club 10 is the hosel 17 . The point where the hosel 17 meets the top of the club 12 is the base of the hosel 18 .
[0039] With respect to FIG. 2, the preferred embodiment selected to illustrate my invention includes a transparent 4 to 5 mil vinyl adhesive strip that provides an abrasion resistant and deflective guard 11 , and is shaped to fit the head of a golf club 10 . Guard 11 has a cut away 19 (also shown in FIG. 1) that is designed to fit around the base of the hosel 18 of club head 10 . The bottom edge of guard 11 has V-shaped notches 20 as shown in FIG. 2 that are designed to compensate for material gathering and potential lifting that can be created by wrapping guard 11 along the contoured top line 14 . Another feature is that guard 11 is designed to accommodate clubs of all sizes, as demonstrated by dashed lines 21 in FIG. 2 that represent alternative sizes. Before installation of guard 11 , the adhesive side 22 of guard 11 , as shown in FIG. 4, is attached to glossy backing paper 23 shown in FIG. 5 that is split into equal halves 24 as shown in FIG. 2.
[0040] [0040]FIGS. 3-5 illustrate the procedure for attaching guard 11 to a golf club head 10 . Before installing guard 11 , it may be necessary to measure and then cut guard 11 to the correct size for each particular club, as shown in FIG. 3. The first step of the installation procedure is to place guard 11 onto top line 14 , while retaining backing paper 23 in place. The second step is to place the cutaway end 19 of the guard 11 at the base of hosel 18 and measure the length of guard 11 . The third step is to mark a line approximately 0.5 cm ({fraction (3/16)} in.) short of toe 15 , which will be the new cut line 25 shown in FIG. 3. The fourth step is to use extra guards 11 as a template, place the extra guard 11 up against the new cut line 25 , and trace around the rounded end of guard 11 to create an appropriately sized guard 21 . The final step is then to take a pair of scissors and cut along the inside of newly sized guard 21 to form a properly sized guard 11 .
[0041] [0041]FIG. 4 now shows a method by which to line up the guard 11 on club head 10 . The first step is to peel back the half of the backing paper 23 from the guard 11 that has the cutaway 19 that fits around hosel 17 , so as to expose adhesive side 22 . The second step is to place guard 11 at the base of hosel 18 and lay the adhesive side of tape 22 along top line 14 between face 13 and top 12 of the club 12 . The V-shaped notches 20 provide a good guide and should align with the top of face 13 . To ensure that guard 11 is lined up, one should only let adhesive side 22 of guard 11 stick to the edge of top line 14 . This will allow easy realignment of guard 11 if not straight in a first attempt.
[0042] As can be seen in FIG. 5, once guard 11 is lined up the next step is to attach guard 11 to top 12 of the club. One may use a thumb and work slowly from the center of guard 11 to the base of hosel 18 , pressing firmly to work all air bubbles out as adhesive side 23 of the guard 11 is affixed to top 12 of the club. The next step is to remove the remaining backing 23 and repeat the last step: working from the center on guard 11 to toe 15 of the club, and again attaching adhesive side 22 of guard 11 only to top 12 of club head 10 . The final step is to use the same technique as was used on the top 12 of club head 10 , and work from top line 14 to the lower edge and press guard 11 to face 13 of club head 10 .
[0043] [0043]FIG. 6 is a perspective view of a club head 10 with guard 11 installed, showing the transparent quality of guard 11 and demonstrating the difficulty of seeing guard 11 .
[0044] [0044]FIG. 7 demonstrates the kind of damage 26 that can occur along top line 14 and top 12 of club head 10 without having used the present invention (guard 11 ). The club shown is of the same type as shown is FIG. 6. Both clubs are approximately the same age and have experienced similar usage.
[0045] With respect to the foregoing description, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
[0046] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended here to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, with the scope of the invention to be determined only by the claims appended hereto.
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A golf club protective guard serves to protect the appearance and lifetime value of golf clubs. The inventive device is a transparent 4 to 5 mil vinyl adhesive strip that is designed to fit the contours of the club, and that when attached to the head of a club provides an almost invisible protective barrier against abrasions caused by miss-hits during the act of hitting the ball.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 15/142,450, filed Apr. 29, 2016, the disclosure of which is incorporated by reference herein in its entirety.
BACKGROUND
The present invention generally relates to complimentary metal-oxide semiconductors (CMOS) and metal-oxide-semiconductor field-effect transistors (MOSFET), and more specifically, to finFET device fabrication.
The MOSFET is a transistor used for switching electronic signals. The MOSFET has a source, a drain and a metal oxide gate electrode. The metal gate is electrically insulated from the main semiconductor n-channel or p-channel by a thin layer of insulating material, for example, silicon dioxide or high dielectric constant (high-k) dielectrics, which makes the input resistance of the MOSFET relatively high. The gate voltage controls whether the path from drain to source is an open circuit (“off”) or a resistive path (“on”).
N-type field effect transistors (nFET) and p-type field effect transistors (pFET) are two types of complementary MOSFETs. The nFET has n-doped source and drain junctions and uses electrons as the current carriers. The pFET has p-doped source and drain junctions and uses holes as the current carriers.
The finFET is a type of MOSFET. The finFET is a multiple-gate MOSFET device that mitigates the effects of short channels and reduces drain-induced barrier lowering. The “fin” refers to a semiconductor material patterned on a substrate that often has three exposed surfaces that form the narrow channel between source and drain regions. A thin dielectric layer arranged over the fin separates the fin channel from the gate. Because the fin provides a three dimensional surface for the channel region, a larger channel length may be achieved in a given region of the substrate as opposed to a planar FET device.
Gate spacers form an insulating film along the gate sidewalls. Gate spacers may also initially be formed along sacrificial gate sidewalls in replacement gate technology. The gate spacers are used to define source/drain regions in active areas of a semiconductor substrate located adjacent to the gate.
Device scaling in the semiconductor industry reduces costs, decreases power consumption and provides faster devices with increased functions per unit area. Improvements in optical lithography have played a major role in device scaling. However, optical lithography has limitations for minimum dimensions and pitch, which are determined by the wavelength of the irradiation.
SUMMARY
According to an embodiment of the present invention, a method for forming a semiconductor device includes forming a first fin and a second fin on a substrate, the first fin arranged in parallel with the second fin, the first fin arranged a first distance from the second fin, the first fin and the second fin extending from a first source/drain region through a channel region and into a second source/drain region on the substrate. The method further includes forming a third fin on the substrate, the third fin arranged in parallel with the first fin and between the first fin and the second fin, the third fin arranged a second distance from the first fin, the second distance is less than the first distance, the third fin having two distal ends arranged in the first source/drain region. A gate stack is formed over the first fin and the second fin.
According to another embodiment of the present invention a semiconductor device comprises a first semiconductor fin arranged on a substrate, the first semiconductor fin having a first distal end, a second distal end, and a medial region arranged between the first distal end and the second distal end, the first distal end of the first semiconductor fin arranged in a first source/drain region and the second distal end of the second semiconductor fin arranged in a second source/drain region. The device further comprises a second semiconductor fin arranged on the substrate, the second semiconductor fin having a first distal end, a second distal end, and a medial region arranged between the first distal end and the second distal end, the second distal end of the second semiconductor fin arranged in the first source/drain region and the second distal end of the second semiconductor fin arranged in the second source/drain region. A third semiconductor fin is arranged on the substrate, the third semiconductor fin having a first distal end, a second distal end, and a medial region arranged between the first distal end and the second distal end, the first distal end and the second distal end of the third semiconductor fin arranged in the first source/drain region. The first semiconductor fin, the second semiconductor fin, and the third semiconductor fin are arranged substantially in parallel with each other, the third semiconductor fin is arranged between the first semiconductor fin and the second semiconductor fin, the first semiconductor fin is arranged a first distance from the second semiconductor fin and the third semiconductor fin is arranged a second distance from the first semiconductor fin, the first distance greater than the second distance. A gate stack is arranged over a channel region of the first semiconductor fin and the second semiconductor fin between the first source/drain region and the second source/drain region.
According to yet another embodiment of the present invention, a method for forming a semiconductor device comprises forming a mandrel on a substrate, forming sacrificial sidewall spacers along sidewalls of the mandrel, and removing the mandrel. The method further comprises removing portions of the substrate to form an arrangement of fins on the substrate. The arrangement of fins includes a first fin arranged substantially in parallel with a second fin in a source/drain region, the first fin arranged a first distance from the second fin and a third fin arranged substantially in parallel with a fourth fin in a channel region, the third fin arranged a second distance from the fourth fin, the second distance is greater than the first distance. The sacrificial sidewall spacers are removed and a gate stack is formed over the channel region.
According to yet another embodiment of the present invention, a semiconductor device comprises a first semiconductor fin arranged in parallel with a second semiconductor fin in a first source/drain region on a substrate. The first semiconductor fin is arranged a first distance from the second semiconductor fin. The device further comprises a third semiconductor fin arranged in parallel with a fourth semiconductor fin in a channel region on the substrate, the third semiconductor fin is arranged a second distance from the fourth semiconductor fin, the second distance greater than the first distance, the first semiconductor fin contacting the third semiconductor fin and the second semiconductor fin contacting the fourth semiconductor fin. A gate stack is arranged over the channel region of the third semiconductor fin and the fourth semiconductor fin.
According to yet another embodiment of the present invention, a method for forming a semiconductor device comprises forming a mandrel on a substrate, forming sacrificial sidewall spacers along sidewalls of the mandrel, and removing the mandrel. Portions of the substrate are removed to form an arrangement of fins on the substrate. The arrangement of fins includes a first fin arranged substantially in parallel with a second fin in a source/drain region, the first fin is arranged a first distance from the second fin and a third fin is arranged substantially in parallel with a fourth fin in a channel region. The third fin is arranged a second distance from the fourth fin, the first distance is greater than the second distance. The sacrificial sidewall spacers are removed, and a gate stack is formed over the channel region.
According to yet another embodiment of the present invention, a semiconductor device comprises a first semiconductor fin arranged in parallel with a second semiconductor fin in a first source/drain region on a substrate, the first semiconductor fin arranged a first distance from the second semiconductor fin. The device further comprises a third semiconductor fin arranged in parallel with a fourth semiconductor fin in a channel region on the substrate, the third semiconductor fin is arranged a second distance from the fourth semiconductor fin, the first distance is greater than the second distance. The first semiconductor fin contacts the third semiconductor fin and the second semiconductor fin contacts the fourth semiconductor fin. A gate stack is arranged over the channel region of the third semiconductor fin and the fourth semiconductor fin.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-19 illustrate an exemplary method for fabricating a finFET device using a sidewall image transfer process with fins having a greater fin pitch in the channel region and a smaller fin pitch in the source/drain regions.
FIG. 1 illustrates a side view of a semiconductor substrate, a hardmask arranged on the substrate, and a sacrificial layer arranged on the hardmask.
FIG. 2 illustrates a top view following the patterning of a mask on the semiconductor layer.
FIG. 3 illustrates a top view following an anisotropic etching process.
FIG. 4 illustrates a cut-away view along the line A-A (of FIG. 3 ) showing a portion of the mandrel arranged on the hardmask.
FIG. 5 illustrates a cut-away view along the line B-B (of FIG. 3 ) showing another portion of the mandrel arranged on the hardmask.
FIG. 6 illustrates a top view following the formation of sacrificial sidewall spacers along sidewalls of the mandrel.
FIG. 7 illustrates a cut-away view along the line A-A (of FIG. 6 ) of a portion of the sacrificial sidewall spacers.
FIG. 8 illustrates a cut-away view along the line B-B (of FIG. 6 ) of another portion of the sacrificial sidewall spacers.
FIG. 9 illustrates a top view following the removal of the mandrel (of FIG. 6 ).
FIG. 10 illustrates a top view following a selective etching process that removes exposed portions of the hardmask and the substrate to form fins.
FIG. 11 illustrates a cut-away view along the line A-A (of FIG. 10 ) of fins that are arranged on the substrate.
FIG. 12 illustrates a cut-away view along the line B-B (of FIG. 10 ) of another portion of the fins.
FIG. 13 illustrates a top view following the removal of the sacrificial sidewall spacers (of FIG. 10 ), which exposes the hardmask.
FIG. 14 illustrates a top view following the formation of a sacrificial gate over the fins (of FIG. 13 ) and spacers adjacent to sidewalls of the sacrificial gate.
FIG. 15 illustrates a top view following the formation of source/drain regions over the fins (of FIG. 14 ).
FIG. 16 illustrates a cut-away view along the line A-A (of FIG. 15 ) of the fins the substrate and the source/drain region formed over the fins and the substrate.
FIG. 17 illustrates a top view following the formation of an inter-level dielectric layer and the removal of the sacrificial gate (of FIG. 15 ) to form a cavity that exposes the channel regions of the fins.
FIG. 18 illustrates a top view of the resultant structure following the formation of a replacement metal gate stack.
FIG. 19 illustrates a cut-away view along the line B-B (of FIG. 18 ) of the gate stack.
FIGS. 20-25 illustrate an exemplary method for fabricating a finFET device using a sidewall image transfer process with fins having a greater fin pitch in the channel region and a smaller fin pitch in the source/drain regions.
FIG. 20 illustrates a top view of following the formation of sacrificial sidewall spacers along sidewalls of the mandrel.
FIG. 21 illustrates a top view following an anisotropic etching process that removes exposed portions of the substrate and forms fins.
FIG. 22 illustrates a cut-away view along the line A-A (of FIG. 21 ) of the fins.
FIG. 23 illustrates a cut-away view along the line B-B (of FIG. 21 ) of the fins.
FIG. 24 illustrates a cut-away view along the line C-C (of FIG. 21 ) of the fins and a merged fin portion.
FIG. 25 illustrates a top view following the formation of a gate stack and spacers along sidewalls of the gate stack.
FIG. 26 illustrates a top view that is partially transparent of fins.
FIG. 27 illustrates a top view that is partially transparent of fins.
FIGS. 28-32 illustrate an exemplary direct patterning method for fabricating a finFET device having a greater fin pitch in the channel region and a smaller fin pitch in the source/drain regions.
FIG. 28 illustrates a top view of an arrangement of fins on a substrate.
FIG. 29 illustrates a top view following the formation of a sacrificial gate stack, spacers, and source/drain regions over the fins (of FIG. 28 ).
FIG. 30 illustrates a top view following the formation of an inter-level dielectric layer over the source/drain regions (of FIG. 29 ) and a replacement gate stack over channel regions of the fins.
FIG. 31 illustrates a cut-away view along the line A-A (of FIG. 30 ) of the fins and the source/drain region.
FIG. 32 illustrates a cut-away view along the line B-B (of FIG. 30 ) of the fins and the gate stack arranged over the fins.
FIG. 33 illustrates a top view of an alternate exemplary arrangement of fins.
DETAILED DESCRIPTION
FinFETs typically include a fin that has a three dimensional profile arranged on a substrate. Previous finFETs often included a fin that has a channel region, a gate stack arranged over the channel region and source/drain regions on opposing sides of the channel region. The size and shape of the fin was substantially uniform through the source/drain regions and the channel region.
In finFET devices with multiple fins arranged in parallel on a substrate, the spacing between the fins (i.e., fin pitch) was substantially uniform between the portions of the fins in the source/drain region and the channel regions. In other words, for a pair of identical fins arranged adjacent to each other and in parallel on a substrate, the distance between the fins is the same in the channel region and the source/drain region.
For high voltage finFETs or some other types of finFETs, a relatively thick gate dielectric and work function metal are desirable to meet performance parameters of such devices. However, as the fin pitch is reduced in order to reduce the scale of the devices on the substrate, the space available between the fins in the channel region becomes smaller. If the desired thickness of the gate dielectric and work function metal is relatively thick compared to the distance between the fins in the channel region, there simply may not be enough space between the fins in the channel region to form a proper multi-gate device.
The illustrated exemplary methods and embodiments describe a finFET device that has fins in the channel region that are sufficiently pitched to allow the deposition of gate dielectric and work function metals at a desired thickness while maintaining the desired performance characteristics of a multi-gate device. The embodiments described herein further provide for fins in the source/drain regions that are spaced at a different pitch than the channel region to allow a uniform formation of epitaxially grown source/drain regions.
FIGS. 1-19 illustrate an exemplary method for fabricating a finFET device using a sidewall image transfer process with fins having a greater fin pitch in the channel region and a smaller fin pitch in the source/drain regions.
FIG. 1 illustrates a side view of a semiconductor substrate 102 , a hardmask 104 arranged on the substrate 102 , and a sacrificial layer 106 arranged on the hardmask 104 .
Non-limiting examples of suitable materials for the substrate 102 include Si (silicon), strained Si, SiC (silicon carbide), Ge (germanium), SiGe (silicon germanium), SiGeC (silicon-germanium-carbon), Si alloys, Ge alloys, III-V materials (e.g., GaAs (gallium arsenide), InAs (indium arsenide), InP (indium phosphide), or aluminum arsenide (AlAs)), II-VI materials (e.g., CdSe (cadmium selenide), CdS (cadmium sulfide), CdTe (cadmium telluride), ZnO (zinc oxide), ZnSe (zinc selenide), ZnS (zinc sulfide), or ZnTe (zinc telluride)), or any combination thereof. Other non-limiting examples of semiconductor materials include III-V materials, for example, indium phosphide (InP), gallium arsenide (GaAs), aluminum arsenide (AlAs), or any combination thereof. The III-V materials may include at least one “III element,” such as aluminum (Al), boron (B), gallium (Ga), indium (In), and at least one “V element,” such as nitrogen (N), phosphorous (P), arsenic (As), antimony (Sb).
The hardmask 104 may include, for example, silicon oxide, silicon nitride (SiN), SiOCN, SiBCN or any suitable combination of those. The hardmask 104 may be deposited using a deposition process, including, but not limited to, PVD, CVD, PECVD, or any combination thereof. The sacrificial layer 106 may include, any suitable material such as, for example, amorphous carbon or amorphous silicon.
FIG. 2 illustrates a top view following the patterning of a mask 202 on the sacrificial layer 106 . Suitable resist masks include photoresists, electron-beam resists, ion-beam resists, X-ray resists and etch resists. The resist may a polymeric spin on material or a polymeric material.
FIG. 3 illustrates a top view following an anisotropic etching process such as, for example, reactive ion etching that removes exposed portions of the sacrificial layer 106 (of FIG. 2 ) to form a mandrel 302 arranged on the hardmask 104 .
FIG. 4 illustrates a cut-away view along the line A-A (of FIG. 3 ) showing a portion of the mandrel 302 arranged on the hardmask 104 . FIG. 5 illustrates a cut-away view along the line B-B (of FIG. 3 ) showing another portion of the mandrel 302 arranged on the hardmask 104 .
FIG. 6 illustrates a top view following the formation of sacrificial sidewall spacers 602 along sidewalls of the mandrel 302 . The sacrificial sidewall spacers 602 may be formed by, for example, depositing a layer of spacer material (not shown) over the exposed portions of the hardmask 104 and the mandrel 302 . Non-limiting examples of suitable materials for the layer of spacer material include dielectric oxides (e.g., silicon oxide), dielectric nitrides (e.g., silicon nitride), dielectric oxynitrides, or any combination thereof. The layer of spacer material is deposited by a suitable deposition process, for example, chemical vapor deposition (CVD) or physical vapor deposition (PVD).
Following the deposition of the layer of spacer material, a suitable anisotropic etching process such as, for example, a reactive ion etching process is performed to remove portions of the layer of spacer material and form sacrificial sidewall spacers 602 .
FIG. 7 illustrates a cut-away view along the line A-A (of FIG. 6 ) of a portion of the sacrificial sidewall spacers 602 . FIG. 8 illustrates a cut-away view along the line B-B (of FIG. 6 ) of another portion of the sacrificial sidewall spacers 602 .
FIG. 9 illustrates a top view following the removal of the mandrel 302 (of FIG. 6 ) using a suitable selective etching process that selectively removes the mandrel 302 without substantially removing or damaging the sacrificial sidewall spacers 602 or the hardmask 104 .
FIG. 10 illustrates a top view following a selective etching process that removes exposed portions of the hardmask 104 and the substrate 102 to form fins.
FIG. 11 illustrates a cut-away view along the line A-A (of FIG. 10 ) of fins 1102 that are arranged on the substrate 102 . The fins 1102 are spaced (pitched) a distance x and will be used in subsequent fabrication processes to form the source/drain regions of the finFET device. FIG. 12 illustrates a cut-away view along the line B-B (of FIG. 10 ) of another portion of the fins 1202 that are pitched a distance y and will be used in subsequent fabrication processes to form the channel region of the device. In the illustrated exemplary embodiment shown in FIGS. 11-12 the distance x is less than the distance y.
FIG. 13 illustrates a top view following the removal of the sacrificial sidewall spacers 602 (of FIG. 10 ), which exposes the hardmask 104 .
FIG. 14 illustrates a top view following the formation of a sacrificial gate 1404 over the fins 1202 (of FIG. 13 ) and spacers 1402 adjacent to sidewalls of the sacrificial gate 1404 .
The sacrificial gates 1404 in the exemplary embodiment are formed by depositing a layer (not shown) of sacrificial gate material such as, for example, amorphous silicon (aSi), or polycrystalline silicon (polysilicon) material or another suitable sacrificial gate material. The sacrificial gate 1404 may further comprises a sacrificial gate dielectric material such as silicon oxide between the nanowires and aSi or polysilicon material.
The layer sacrificial gate material may be deposited by a deposition process, including, but not limited to, physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD, plasma enhanced chemical vapor deposition (PECVD), inductively coupled plasma chemical vapor deposition (ICP CVD), or any combination thereof.
Following the deposition of the layer of sacrificial gate material, a hard mask layer (not shown) such as, for example, silicon oxide, silicon nitride (SiN), SiOCN, SiBCN or any suitable combination of those materials, is deposited on the layer of sacrificial gate material to form a PC hard mask or sacrificial gate cap (not shown). The hardmask layer may be deposited using a deposition process, including, but not limited to, PVD, CVD, PECVD, or any combination thereof.
Following the deposition of the layer sacrificial gate material and the hardmask layer, a lithographic patterning and etching process such as, for example, reactive ion etching or a wet etching process is performed to remove exposed portions of the hardmask layer and the layer of sacrificial gate material form the sacrificial gates 1404 and the sacrificial gate caps.
In FIG. 14 , spacers 1402 are formed adjacent to the sacrificial gates 1404 . The spacers 1402 in the illustrated embodiment are formed by depositing a layer of spacer material (not shown) over the exposed portions of the substrate 102 , the fins 1202 , and the sacrificial gates 1404 . Non-limiting examples of suitable materials for the layer of spacer material include dielectric oxides (e.g., silicon oxide), dielectric nitrides (e.g., silicon nitride), dielectric oxynitrides, or any combination thereof. The layer of spacer material is deposited by a suitable deposition process, for example, chemical vapor deposition (CVD) or physical vapor deposition (PVD).
Following the deposition of the layer of spacer material, a suitable anisotropic etching process such as, for example, a reactive ion etching process is performed to remove portions of the layer of spacer material and form the spacers 1402 .
FIG. 15 illustrates a top view following the formation of source/drain regions 1502 over the fins 1102 (of FIG. 14 ). The source/drain regions 1502 are formed by an epitaxial growth process that deposits a crystalline overlayer of semiconductor material onto the exposed crystalline seed material of the exposed fin 1202 to form the source/drain regions 1502 .
Epitaxial materials may be grown from gaseous or liquid precursors. Epitaxial materials may be grown using vapor-phase epitaxy (VPE), molecular-beam epitaxy (MBE), liquid-phase epitaxy (LPE), or other suitable process. Epitaxial silicon, silicon germanium, and/or carbon doped silicon (Si:C) silicon can be doped during deposition (in-situ doped) by adding dopants, n-type dopants (e.g., phosphorus or arsenic) or p-type dopants (e.g., boron or gallium), depending on the type of transistor. The dopant concentration in the source/drain can range from 1×10 19 cm −3 to 2×10 21 cm −3 , or between 2×10 20 cm −3 and 1×10 21 cm −1 .
The terms “epitaxial growth and/or deposition” and “epitaxially formed and/or grown” mean the growth of a semiconductor material (crystalline material) on a deposition surface of another semiconductor material (crystalline material), in which the semiconductor material being grown (crystalline overlayer) has substantially the same crystalline characteristics as the semiconductor material of the deposition surface (seed material). In an epitaxial deposition process, the chemical reactants provided by the source gases are controlled and the system parameters are set so that the depositing atoms arrive at the deposition surface of the semiconductor substrate with sufficient energy to move about on the surface such that the depositing atoms orient themselves to the crystal arrangement of the atoms of the deposition surface. Therefore, an epitaxially grown semiconductor material has substantially the same crystalline characteristics as the deposition surface on which the epitaxially grown material is formed. For example, an epitaxially grown semiconductor material deposited on a {100} orientated crystalline surface will take on a {100} orientation. In some embodiments, epitaxial growth and/or deposition processes are selective to forming on semiconductor surface, and generally do not deposit material on exposed surfaces, such as silicon dioxide or silicon nitride surfaces.
In some embodiments, the gas source for the deposition of epitaxial semiconductor material include a silicon containing gas source, a germanium containing gas source, or a combination thereof. For example, an epitaxial Si layer may be deposited from a silicon gas source that is selected from the group consisting of silane, disilane, trisilane, tetrasilane, hexachlorodisilane, tetrachlorosilane, dichlorosilane, trichlorosilane, methylsilane, dimethylsilane, ethylsilane, methyldisilane, dimethyldisilane, hexamethyldisilane and combinations thereof. An epitaxial germanium layer can be deposited from a germanium gas source that is selected from the group consisting of germane, digermane, halogermane, dichlorogermane, trichlorogermane, tetrachlorogermane and combinations thereof. While an epitaxial silicon germanium alloy layer can be formed utilizing a combination of such gas sources. Carrier gases like hydrogen, nitrogen, helium and argon may be used.
FIG. 16 illustrates a cut-away view along the line A-A (of FIG. 15 ) of the fins 1102 the substrate 102 and the source/drain region 1502 formed over the fins 1102 and the substrate 102 .
FIG. 17 illustrates a top view following the formation of an inter-level dielectric layer 1702 and the removal of the sacrificial gate 1404 (of FIG. 15 ) to form a cavity 1701 that exposes the channel regions of the fins 1202 . The inter-level dielectric layer 1702 is formed from, for example, a low-k dielectric material (with k<4.0), including but not limited to, silicon oxide, spin-on-glass, a flowable oxide, a high density plasma oxide, borophosphosilicate glass (BPSG), or any combination thereof. The inter-level dielectric layer 1702 is deposited by a deposition process, including, but not limited to CVD, PVD, plasma enhanced CVD, atomic layer deposition (ALD), evaporation, chemical solution deposition, or like processes. Following the deposition of the inter-level dielectric layer 1702 , a planarization process such as, for example, chemical mechanical polishing is performed.
The sacrificial gates 1404 may be removed by performing a dry etch process, for example, RIE, followed by a wet etch process. The wet etch process is selective to (will not substantially etch) the spacers 1402 and the inter-level dielectric material. The chemical etch process may include, but is not limited to, hot ammonia or tetramethylammonium hydroxide (TMAH).
FIG. 18 illustrates a top view of the resultant structure following the formation of a replacement metal gate stack (gate stack) 1801 . FIG. 19 illustrates a cut-away view along the line B-B (of FIG. 18 ) of the gate stack 1801 . The gate stack 1801 includes high-k metal gates formed, for example, by filling the cavity 1701 (of FIG. 17 ) with one or more gate dielectric 1902 materials, one or more workfunction metals 1904 , one or more metal gate conductor 1906 materials, and a gate cap 1802 . The gate dielectric 1902 material(s) can be a dielectric material having a dielectric constant greater than 3.9, 7.0, or 10.0. Non-limiting examples of suitable materials for the dielectric 1902 materials include oxides, nitrides, oxynitrides, silicates (e.g., metal silicates), aluminates, titanates, nitrides, or any combination thereof. Examples of high-k materials (with a dielectric constant greater than 7.0) include, but are not limited to, metal oxides such as hafnium oxide, hafnium silicon oxide, hafnium silicon oxynitride, lanthanum oxide, lanthanum aluminum oxide, zirconium oxide, zirconium silicon oxide, zirconium silicon oxynitride, tantalum oxide, titanium oxide, barium strontium titanium oxide, barium titanium oxide, strontium titanium oxide, yttrium oxide, aluminum oxide, lead scandium tantalum oxide, and lead zinc niobate. The high-k material may further include dopants such as, for example, lanthanum and aluminum.
The gate dielectric 1902 materials may be formed by suitable deposition processes, for example, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), evaporation, physical vapor deposition (PVD), chemical solution deposition, or other like processes. The thickness of the dielectric material may vary depending on the deposition process as well as the composition and number of high-k dielectric materials used. The dielectric material layer may have a thickness in a range from about 0.5 to about 20 nm.
The work function metal(s) 1904 may be disposed over the gate dielectric 1902 material. The type of work function metal(s) 1904 depends on the type of transistor and may differ between the nFET and pFET devices. Non-limiting examples of suitable work function metals 1904 include p-type work function metal materials and n-type work function metal materials. P-type work function materials include compositions such as ruthenium, palladium, platinum, cobalt, nickel, and conductive metal oxides, or any combination thereof. N-type metal materials include compositions such as hafnium, zirconium, titanium, tantalum, aluminum, metal carbides (e.g., hafnium carbide, zirconium carbide, titanium carbide, and aluminum carbide), aluminides, or any combination thereof. The work function metal(s) may be deposited by a suitable deposition process, for example, CVD, PECVD, PVD, plating, thermal or e-beam evaporation, and sputtering.
The gate conductor 1906 material(s) is deposited over the gate dielectric 1902 materials and work function metal(s) 1904 to form the gate stack 1801 . Non-limiting examples of suitable conductive metals include aluminum (Al), platinum (Pt), gold (Au), tungsten (W), titanium (Ti), or any combination thereof. The gate conductor 1906 material(s) may be deposited by a suitable deposition process, for example, CVD, PECVD, PVD, plating, thermal or e-beam evaporation, and sputtering.
Following the deposition of the gate dielectric 1902 materials, the work function metal(s) 1904 , and the gate conductor 1906 material(s), planarization process, for example, chemical mechanical planarization (CMP), is performed to remove the overburden of the deposited gate materials and form the gate stack 1801 .
FIGS. 20-25 illustrate an exemplary method for fabricating a finFET device using a sidewall image transfer process with fins having a greater fin pitch in the channel region and a smaller fin pitch in the source/drain regions.
FIG. 20 illustrates a top view of following the formation of sacrificial sidewall spacers 2002 along sidewalls of the mandrel 302 . The resultant structure is formed using a similar process as described above in FIGS. 1-6 however; the sacrificial sidewall spacers 2002 are wider than the sacrificial sidewall spacers 602 (of FIG. 6 ). The sacrificial sidewall spacers 2002 may be formed by depositing a relatively thicker layer of spacer material followed by an etch back process that forms the sacrificial sidewall spacers 2002 .
FIG. 21 illustrates a top view following an anisotropic etching process that removes exposed portions of the substrate 102 and forms fins 2102 and 2104 . Following the formation of the fins 2102 and 2104 , the sacrificial sidewall spacer 2002 is removed using, for example a selective etching process. FIG. 22 illustrates a cut-away view along the line A-A (of FIG. 21 ) of the fins 2102 . FIG. 23 illustrates a cut-away view along the line B-B (of FIG. 21 ) of the fins 2104 . FIG. 24 illustrates a cut-away view along the line C-C (of FIG. 21 ) of the fins 2102 and a merged fin portion 2402 . The merged fin portion 2402 is partially defined by the intersection of the fins 2102 and 2104 . The fins 2102 are spaced (pitched) a distance x′ and will be used in subsequent fabrication processes to form the source/drain regions of the finFET device. The fins 2104 that are pitched a distance y′ and will be used in subsequent fabrication processes to form the channel region of the device. In the illustrated exemplary embodiment shown in FIGS. 22-23 the distance x′ is less than the distance y′.
FIG. 25 illustrates a top view following the formation of a gate stack 1801 and spacers 1402 along sidewalls of the gate stack 1801 and an inter-level dielectric layer 1702 that are formed using a process similar to the gate stack formation process described above.
FIG. 26 illustrates a top view that is partially transparent of fins 1102 and 1202 . FIG. 26 is similar to FIG. 14 described above however; the spacers 1402 and gate stack 1801 are slightly offset in alignment with the fins 1102 and 1202 such that portions of the fins 1102 in the region 2601 are arranged below the gate stack 1801 . The offset in alignment of the gate stack 1801 results in portions of the fins 1202 in the region 2603 are arranged below the spacer 1402 .
FIG. 27 illustrates a top view that is partially transparent of fins 2101 and 2104 . FIG. 27 is similar to FIG. 21 described above however; the spacers 1402 and gate stack 1801 are slightly offset in alignment with the fins 2101 and 2104 such that portions of the fins 2101 in the region 2701 are arranged below the gate stack 1801 . The offset in alignment of the gate stack 1801 results in portions of the fins 2101 in the region 2703 are arranged below the spacer 1402 .
FIGS. 28-32 illustrate an exemplary direct patterning method for fabricating a finFET device having a greater fin pitch in the channel region and a smaller fin pitch in the source/drain regions.
FIG. 28 illustrates a top view of an arrangement of fins 2802 and fins 2804 on a substrate 102 . The fins 2802 and fins 2804 in the illustrated embodiment have been formed by a lithographic patterning and etching process such as, for example, reactive ion etching that removes semiconductor material to form the fins 2802 and 2804 .
FIG. 29 illustrates a top view following the formation of a sacrificial gate stack 1404 , spacers 1402 , and source/drain regions 2902 over the fins 2802 (of FIG. 28 ) using a similar process as described above.
FIG. 30 illustrates a top view following the formation of an inter-level dielectric layer 1702 over the source/drain regions 2902 (of FIG. 29 ) and a replacement gate stack 1801 over channel regions of the fins 2804 .
FIG. 31 illustrates a cut-away view along the line A-A (of FIG. 30 ) of the fins 2802 and the source/drain region 2902 . FIG. 32 illustrates a cut-away view along the line B-B (of FIG. 30 ) of the fins 2804 and the gate stack 1802 arranged over the fins 2804 . The fins 2802 are spaced (pitched) a distance x″ and form a portion of the source/drain regions of the finFET device. The fins 2804 that are pitched a distance y″ and will be used in subsequent fabrication processes to form the channel region of the device. In the illustrated exemplary embodiment shown in FIGS. 28-32 the distance x″ is less than the distance y″.
FIG. 33 illustrates a top view of an alternate exemplary arrangement of fins 3300 . The fins 3300 are formed using a similar process as described above in FIGS. 1-13 however, the pattern of the fins is such that the fins 3302 that are arranged in the source/drain region have a larger pitch than the fins 3304 that are arranged in the channel region. Following the formation of the arrangement of the 3300 , a similar process as described above in FIGS. 14-19 may be performed to form a finFET device with a gate stack over the fins 3304 and source/drain region over the fins 3302 .
The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
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A method for forming a semiconductor device includes forming a first fin and a second fin on a substrate, the first fin arranged in parallel with the second fin, the first fin arranged a first distance from the second fin, the first fin and the second fin extending from a first source/drain region through a channel region and into a second source/drain region on the substrate. The method further includes forming a third fin on the substrate, the third fin arranged in parallel with the first fin and between the first fin and the second fin, the third fin arranged a second distance from the first fin, the second distance is less than the first distance, the third fin having two distal ends arranged in the first source/drain region. A gate stack is formed over the first fin and the second fin.
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This application claims priority under 35 U.S.C. 119 to Japanese Application No. 2005-092067, filed Mar. 28, 2005 and Japanese Application No. 2006-023865, filed Jan. 31, 2006, which applications are incorporated herein by reference and made a part hereof.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a constant temperature crystal oscillator (hereinafter referred to as a constant temperature oscillator) using a surface-mount crystal resonator (hereinafter referred to as a surface-mount resonator), and more specifically to a constant temperature oscillator which excels in response characteristic to a temperature change.
2. Description of the Related Art
Generally, a constant temperature oven has been used for a constant temperature oscillator. Since the operation temperature of a crystal resonator can be kept constant, the frequency stability is high (the frequency deviation is approximately 0.05 ppm or lower). For example, it is used for the communication facilities of a base station for optical communications, etc. Recently, these communication facilities have become downsized. In this connection, a surface-mount resonator has been widely adopted. The Applicant of the present invention has disclosed one of these facilities (Japanese Patent Application No. 2004-157072).
FIGS. 1A , 1 B, 2 A, and 2 B are explanatory views showing a related art. FIG. 1A is a sectional view of a constant temperature oscillator. FIG. 1B is a plan view of the first substrate. FIG. 2A is a sectional view of a surface-mount resonator. FIG. 2B is a bottom view.
The constant temperature oscillator has a surface-mount resonator 1 A, an oscillation circuit element 1 for forming an oscillation circuit together with the resonator, and a temperature control element 2 for keeping a constant operation temperature of the surface-mount resonator 1 A arranged on a circuit substrate 3 , and these components are airtightly sealed in a metal container 4 . The surface-mount resonator 1 A fixes a crystal element 7 using a conductive adhesive 6 on the inside bottom portion of a concave ceramic container body 5 , a metal cover 8 is used as a cover and airtightly seals the entire structure.
At the four corners of the outside bottom portion (reverse side) of the container body 5 , crystal terminals 9 a and dummy terminals 9 b are provided as mount terminals for a set substrate of a wireless equipment, etc. The crystal terminals 9 a (two terminals) are provided at a set of diagonal portions, and connected to an excitation electrode (not shown in the attached drawings) of the crystal element. The dummy terminals 9 b (two terminals) are provided at the other diagonal portions, and are normally connected to the metal cover 8 using a via hole, etc. (not shown in the attached drawings), and function as, for example, grounding terminals connected to a grounding pattern (not shown in the attached drawings) of the substrate.
The temperature control element 2 keeps the constant operation temperature of the surface-mount resonator 1 A, and includes at least a heating chip resistor 2 a (for example, two resistors), a power transistor 2 b for supplying power to the resistors, and a temperature sensitive resistor 2 c for detecting the operation temperature of the surface-mount resonator 1 A. The temperature sensitive resistor 2 c is assumed to be a thermistor indicating a decreasing resistance value with an increasing temperature. The power transistor 2 b provides the power controlled by the resistance value based on the temperature of the temperature sensitive resistor 2 c for the heating chip resistor 2 a . Thus, the operation temperature of the surface-mount resonator 1 A is kept constant.
The circuit substrate circuit substrate 3 includes a first substrate 3 a and a second substrate 3 b , and the second substrate 3 b is held by a metal pin 10 a on the first substrate 3 a . The first substrate 3 a is made of a glass epoxy material, and the oscillation circuit element 1 excluding the surface-mount resonator 1 A is arranged on the bottom surface. The second substrate 3 b is made of a ceramic material, and has the crystal resonator 1 A arranged on the top surface, and has the chip resistor 2 a and the temperature sensitive resistor 2 c excluding the power transistor 2 b in the temperature control element 2 arranged on the bottom surface.
Between the first substrate 3 a and the second substrate 3 b , a silicon base thermal conductive resin 11 is applied for covering the chip resistor 2 a and the temperature sensitive resistor 2 c . Since the power transistor 2 b is long in height, it is arranged on the terminal side of the first substrate 3 a . The metal container 4 is formed by a metal base 4 a and a cover 4 b . An airtight terminal 10 b of the metal base 4 a holds the first substrate 3 a , and the cover 4 b airtightly sealed by resistance welding. The dummy terminal 9 b as a grounding terminal of the crystal resonator 1 A is connected to the airtight terminal 10 b for grounding through the conductive path (grounding pattern) not shown in the attached drawings and the metal pin 10 a.
In this example, electric power is supplied to the heating chip resistor 2 a by, for example, a well-known temperature control circuit shown in FIG. 3A . That is, a temperature sensitive voltage by the temperature sensitive resistor 2 c and a resistor Ra is applied to one input terminal of an operational amplifier 12 , and a reference voltage by resistors Rb and Rc is applied to the other input terminal. Then, the reference temperature difference voltage from the reference voltage is applied to the base of the power transistor 2 b , and electric power is supplied from the direct current voltage DC to the heating chip resistor 2 a . Thus, the electric power to the heating chip resistor 2 a can be controlled by the resistance value depending on the temperature of the temperature sensitive resistor 2 c.
Normally, before connecting the metal cover 4 b by setting the first and second circuit substrates 3 a and 3 b to the metal base 4 a , for example, the frequency temperature characteristic as the cubic curve shown in FIG. 3B of the surface-mount resonator 1 A as, for example, AT cut is individually measured. When the temperature as the minimum value at the high temperature side of the operation temperature of the surface-mount resonator 1 A is, for example, 80° C., the resistor Ra of the temperature control circuit is controlled and the surface-mount resonator 1 A is set to 80° C. Then, the control capacitor (not shown in the attached drawings) of the oscillation circuit matches the oscillation frequency f with the nominal frequency. Thus, the resistor Ra and the control elements 13 which require exchange such as the control capacitor, etc. are arranged on the perimeter of the first substrate 3 a horizontally projecting from the second substrate 3 b ( FIG. 1 ).
With the above-mentioned configuration, the conventional constant temperature oven not shown in the attached drawings is not used, and the heating chip resistor 2 a is used as a heat source. Therefore, the entire system can be basically downsized. Then, the second substrate 3 b having the surface-mount resonator 1 A, the chip resistor 2 a , and the temperature sensitive resistor 2 c is a highly thermal conductive ceramic material. These components are covered with a thermal conductive resin. Therefore, the operation temperature of the surface-mount resonator 1 A can be directly detected by the temperature sensitive resistor 2 c , and the response characteristic to a temperature change can be improved.
However, in the constant temperature oscillator with the above-mentioned configuration, although the surface-mount resonator 1 A and the temperature sensitive resistor 2 c are arranged on both main surface sides of the second substrate 3 b which is made of a highly thermal conductive ceramic material, the thermal conductivity is low (poor thermal conductivity) as compared with copper (Cu), gold (Au), etc. as a wiring pattern, for example. Therefore, since the resistance value of the temperature sensitive resistor is not immediately changed in synchronization with the operation temperature of the surface-mount resonator, and the operation temperature cannot be detected in real time, there has been the problem that the response characteristic to an ambient temperature is poor.
Since the first substrate 3 a and the second substrate 3 b are arranged up and down by the metal pin 10 a , the number of production processes can be increased and the height is increased. Furthermore, since the second substrate 3 b is made of a ceramic material, it is more expensive than a substrate of a glass epoxy material. In addition, since the power transistor 2 b of the temperature control element 2 is long in height, it is arranged on the first substrate 3 a aside from the second substrate 3 b on which the chip resistor 2 a is arranged. Therefore, the liberated heat from the power transistor 2 b can be prevented from being effectively used.
SUMMARY OF THE INVENTION
The first object of the present invention is to improve the response characteristic to a temperature change, the second object of the present invention is to enhance the productivity by reducing the height, and the third object is to effectively use a heat source when a constant temperature oscillator is provided.
As described in the scope of the claims (claim 1 ) for the present invention, a constant temperature crystal oscillator includes on a circuit substrate: a surface-mount crystal resonator which is provided with two crystal terminals as mount terminals and a dummy terminal, and has a metal cover; an oscillation circuit element which forms an oscillation circuit together with the crystal resonator; and a temperature control element which keeps a constant operation temperature of the crystal resonator. The temperature control element includes at least a heating chip resistor, a power transistor for supplying electric power to the chip resistor, and a temperature sensitive resistor for detecting the operation temperature of the crystal resonator. A dummy terminal on the substrate side of the circuit substrate for connection to the dummy terminal of the crystal resonator is connected to a resistor terminal on the substrate side to which the temperature sensitive resistor is connected through a conductive path (corresponding to the first through third embodiments).
With the above-mentioned configuration, the dummy terminal of the surface-mount resonator is connected to the temperature sensitive resistor through a conductive path. Therefore, the temperature of the surface-mount resonator is directly transmitted to the temperature sensitive resistor. Therefore, the electric power supplied to the heating chip resistor from the power transistor responsive in real time to the temperature change of the surface-mount resonator can be controlled. Thus, the response characteristic to the temperature change can be successfully maintained.
According to claim 2 of the present invention based on claim 1 , the dummy terminal is electrically connected to the metal cover of the crystal resonator. Thus, the extraneous noise reaching the metal cover is consumed by the heating chip resistor through the dummy terminal on the substrate side, and is connected (flows into) the power supply. Therefore, the EMI (electromagnetic interference) can be suppressed by maintaining the metal cover at a constant voltage. In this case, since the dummy terminal is not connected to a grounding pattern of the circuit substrate as in the related art, the liberated heat through the grounding pattern can be suppressed (corresponding to the first through third embodiments).
According to claim 3 based on claim 1 , the crystal resonator has two dummy terminals and the two crystal terminals at the four corners on the bottom. The circuit substrate has the dummy terminal on the substrate side and a crystal terminal on the substrate side to which the two crystal terminals are connected. At least one of the dummy terminal on the substrate side connected to the resistor terminal on the substrate side through a conductive path extends to at least the central area facing the bottom surface of the crystal resonator, and has a larger area than the crystal terminal (corresponding to the second embodiment).
With the according to configuration, the dummy terminal on the substrate side connected to the resistor terminal on the substrate side is formed with a large area while facing the bottom surface of the crystal resonator. Therefore, the radiant heat is absorbed from the crystal resonator. As a result, the operation temperature of the crystal resonator can be detected by the temperature sensitive resistor in real time.
According to claim 4 based on claim 3 , the two dummy terminal on the substrate side is commonly connected through the conductive path (corresponding to the second embodiment). Thus, since the area of the dummy terminal on the substrate side can be further enlarged and the radiant heat can be absorbed, the operation temperature of the crystal resonator can be furthermore detected in real time.
According to claim 5 based on claim 1 , the crystal resonator is arranged between the power transistor and the chip resistor, and the temperature sensitive resistor is arranged adjacent to the crystal resonator (corresponding to the first through third embodiments). Thus, the radiant heat from the power transistor can be effectively used. In this case, one heating chip resistor can be reduced from the configuration according to the related art, thereby realizing a more economical configuration.
According to claim 6 based on claim 5 , the conductive path electrically connecting the power transistor to the chip resistor can be formed by traversing below the external bottom surface of the crystal resonator (corresponding to the third embodiment). In this case, the radiant heat from the conductive path electrically connecting the power transistor to the chip resistor is added to the bottom surface of the crystal resonator, thereby further effectively utilizing the heat source.
According to claim 7 based on claim 6 , the conductive path is cross-shaped between the mount terminals provided at the four corners of the crystal resonator (corresponding to the third embodiments). Thus, the radiant heat can be applied to the entire bottom surface of the crystal resonator, thereby further effectively realizing the heat source.
According to claim 8 based on claim 1 , the circuit substrate is a single plate and is made of a glass epoxy material (corresponding to the first through third embodiments). Thus, since the circuit substrate on which the oscillation circuit element including the surface-mount resonator and the temperature control element are arranged is a single plate, the height of the constant temperature oscillator can be reduced. In addition, it is not necessary to arrange the first and second substrates above and below using a metal pin as in the related art. Additionally, the epoxy material is less expensive than the ceramic material. Therefore, the productivity can be enhanced.
According to claim 9 based on claim 1 , the crystal resonator, the power transistor, the heating chip resistor, and the temperature sensitive resistor are covered with a thermal conductivity resin (corresponding to the first through third embodiments). Thus, the thermal conductivity among the crystal resonator, the power transistor, the chip resistor, and the temperature sensitive resistor can be enhanced. Especially, the temperature between the surface-mount resonator and the temperature sensitive resistor can be leveled. Since the heat from the power transistor and the heating chip resistor is transmitted to the surface-mount resonator, the response characteristic to a temperature change can be further improved.
According to claim 10 based on claim 1 , the circuit substrate is held by the airtight terminal of the metal base. The crystal resonator, the heating chip resistor, the power transistor, and the temperature sensitive resistor are arranged below the bottom surface of the circuit substrate facing the metal base. The oscillation circuit element and the control element in the temperature control element are arranged on the top surface of the circuit substrate (according to the first through third embodiments). Thus, for example, the controlling operation of the control element before covering the metal base can be more easily performed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory view of the related art in which FIG. 1A is a sectional view of the constant temperature oscillator, and FIG. 1B is a plan view of the second substrate;
FIG. 2 is an explanatory view of the surface-mount resonator in which FIG. 2A is a sectional view, and FIG. 2B is a bottom view;
FIG. 3 is an explanatory view of the related art in which FIG. 3A shows the temperature control circuit diagram of the constant temperature, and FIG. 3B shows the frequency temperature characteristic of the surface-mount resonator;
FIG. 4 is an explanatory view of the first embodiment of the present invention in which FIG. 4A is a sectional view of the constant temperature oscillator, and FIG. 4B is a plan view of the circuit substrate;
FIG. 5 is an explanatory view of the second embodiment of the present invention in which FIGS. 5A and 5B are plan views of the circuit substrate of the constant temperature oscillator; and
FIG. 6 is an explanatory view of the third embodiment of the present invention, and is a plan view of the circuit substrate of the constant temperature oscillator.
DESCRIPTION OF THE PREFERRED EMBODIMENT
First Embodiment
FIG. 4 is an explanatory view of the first embodiment of the present invention in which FIG. 4A is a sectional view of the constant temperature oscillator, and FIG. 4B is a plan view of the circuit substrate. The explanation of the same components of the related art is simply described or omitted here.
As described above, the constant temperature oscillator arranges on the circuit substrate 3 the existing surface-mount resonator 1 A, the oscillation circuit element 1 forming an oscillation circuit with the resonator, and the temperature control element 2 for leveling the operation temperature by including at least the heating chip resistor 2 a , the power transistor 2 b , and the temperature sensitive resistor 2 c . These components-are airtightly sealed in the metal container 4 . In this example, the circuit substrate 3 is a single plate (single substrate) made of a glass epoxy material, and the bottom surface of the circuit substrate 3 faces the metal base 4 a . The circuit substrate is a single plate, but it also can be a layered substrate.
On the top surface of the circuit substrate 3 , the oscillation circuit element 1 excluding the surface-mount resonator 1 A is arranged, and on the bottom surface, the surface-mount resonator 1 A and the temperature control element 2 are arranged. The surface-mount resonator 1 A is arranged at the central portion of the circuit substrate 3 with the heating chip resistor 2 a and the power transistor 2 b of the temperature control element 2 placed on the respective sides of the surface-mount resonator 1 A. Then, the temperature sensitive resistor 2 c having the smallest planar shape formed by a thermistor is arranged between the surface-mount resonator 1 A and, for example, the power transistor 2 b . The surface-mount resonator 1 A and the temperature control element 2 are covered with the thermal conductive resin 11 . The thermal conductive resin 11 is based on silicon as described above, and is about 100 times as thermal-conductive as air.
Among substrate-side terminals 14 of the circuit substrate 3 in which the surface-mount resonator 1 A and the temperature control elements 2 (chip resistor 2 a , power transistor 2 b , and temperature sensitive resistor 2 c ) are fixed by soldering, etc., a substrate-side dummy terminal 14 x connected to one of the above-mentioned dummy terminals 9 b of the surface-mount resonator 1 A is commonly connected by a substrate-side resistor terminal 14 y and a conductive path 14 z connected to one of the mount terminals (not shown in the attached drawings) of the temperature sensitive resistor 2 c , and has the same potential (voltage dividing power supply voltage) as one mount terminal 14 y of the temperature sensitive resistor 2 c
The wiring pattern not shown in the attached drawings including the substrate-side dummy terminal 14 x , the substrate-side resistor terminal 14 y , and the conductive path 14 z is formed by the materials more excellent in thermal conductivity than the ceramic material, for example, Au and Cu. The other terminal of the substrate-side dummy terminal 14 x is not connected to the grounding pattern of the set substrate but terminated (electrically open terminal).
In this example, as described above, after setting the circuit substrate 3 to the metal base 4 a , the frequency temperature characteristic of the surface-mount resonator 1 A is individually measured. Depending on the minimum value of the frequency temperature characteristic, the resistor Ra of the temperature control circuit is controlled, and the surface-mount resonator 1 A is set to the temperature of the minimum value, for example, 80° C. The control capacitor allows the oscillation frequency f to match the nominal frequency. In this case, the control elements 13 such as the resistor Ra, control capacitor, etc. are arranged on the top surface of the circuit substrate 3 .
With the above-mentioned configuration, as explained in Summary of the Invention, since the dummy terminal 9 b of the surface-mount resonator 1 A is connected to the mount terminal of the temperature sensitive resistor 2 c through the conductive path 14 z , the temperature (heat) of the surface-mount resonator 1 A is directly conducted to the temperature sensitive resistor 2 c . Therefore, the temperature sensitive resistor 2 c responds to the temperature change of the surface-mount resonator 1 A in real time, thereby correctly controlling the power supplied from the power transistor 2 b to the heating chip resistor 2 a . Thus, the response characteristic to a temperature change can be correctly maintained.
Additionally, since the oscillation circuit element including the surface-mount resonator 1 A and the temperature control element 2 are arranged on the circuit substrate 3 as a single plate, the height of the constant temperature oscillator can be reduced in simple production. Since the circuit substrate 3 is simply made of a glass epoxy single plate, it is less expensive than a ceramic plate, and has improved productivity.
The surface-mount resonator 1 A is arranged between the heating chip resistor 2 a and the power transistor 2 b , and the temperature sensitive resistor 2 c is arranged adjacent to the surface-mount resonator 1 A. Therefore, the liberated heat from the power transistor 2 b can be effectively used. In this example, one heating chip resistor 2 a can be reduced and more economical than the related art.
The surface-mount resonator 1 A and the temperature control element 2 (chip resistor 2 a , power transistor 2 b , and temperature sensitive resistor 2 c ) are covered with the thermal conductive resin 11 . Thus, the thermal conductivity can be enhanced between the surface-mount resonator 1 A and the temperature control element 2 . Especially, the temperatures of the surface-mount resonator 1 A and the temperature sensitive resistor 2 c can be leveled. Then, since the heat from the power transistor 2 b and the heating chip resistor 2 a can be conducted to the surface-mount resonator 1 A by the thermal conductive resin 11 , the response characteristic to a temperature change can be further improved.
Furthermore, since the resistor Ra of the temperature control circuit and the control elements 13 such as the control capacitor, etc. of the oscillation circuit are arranged on the top surface of the circuit substrate 3 , the controlling operations (exchange, etc.) can be easily performed. Since the arrangement can be made on any part of the top surface, the arranging design can be freely determined without restrictions.
The other end of the substrate-side dummy terminal 14 x is not connected to the grounding pattern and terminated. Therefore, the heat is prevented from being liberated through the grounding pattern and the airtight terminal 10 b , the thermal efficiency can be improved. In this case, the substrate-side dummy terminal 14 x electrically connected to the metal cover 8 of the surface-mount resonator 1 A is connected to the power supply voltage through the temperature sensitive resistor 2 c . Therefore, although extraneous noise reaches the metal cover 8 , the extraneous noise is consumed by the temperature sensitive resistor 2 c and absorbed by the power supply voltage, and the substrate-side dummy terminal 14 x is maintained to be equal to the other terminal for a constant voltage of the same potential (direct current voltage). Thus, the EMI, etc. can be avoided.
Second Embodiment
FIGS. 5A and 5B are explanatory views of the second embodiment of the present invention, and are plan views of the circuit substrate of the constant temperature oscillator. The same components between the embodiment and the related art are assigned the same reference numerals, and the detailed explanation is simplified or omitted here.
According to the second embodiment shown in, for example, FIG. 5A , the substrate-side dummy terminal 14 x connected to one of the dummy terminals 9 b of the surface-mount resonator 1 A extends at least to the central area facing the bottom surface of the surface-mount resonator 1 A. For example, it also extends between the substrate-side crystal terminal 14 of a set of diagonal portions and the substrate-side dummy terminal 14 x of the other set of diagonal portions. In FIG. 5B , one of the diagonal portion of the other set is commonly connected to the other substrate-side dummy terminal 14 x . Thus, one of the substrate-side dummy terminal 14 x becomes larger in area than the crystal terminal on the substrate side.
With the above-mentioned configuration, one of the substrate-side dummy terminal 14 x totally faces the bottom surface of the surface-mount resonator 1 A including the case where it is commonly connected to the other terminal of the substrate-side dummy terminal 14 x . Therefore, the liberated heat of the surface-mount resonator 1 A is totally absorbed and conducted to the substrate-side resonator terminal 14 y of the temperature sensitive resistor 2 c . Thus, the operation temperature of the surface-mount resonator can be detected in real time, and the response characteristic to the temperature of the surface-mount resonator can be furthermore enhanced.
Third Embodiment
FIG. 6 is an explanatory view of the third embodiment of the present invention, and is a plan view of the circuit substrate of the constant temperature oscillator. The same components between the embodiment and the related art are assigned the same reference numerals, and the detailed explanation is simplified or omitted here.
In the third embodiment, the substrate-side dummy terminal 14 x of the surface-mount resonator 1 A is connected to the substrate-side resistor terminal 14 y of the temperature sensitive resistor 2 c as in the first embodiment through the conductive path 14 z . In this example, the heating chip resistor 2 a and the power transistor 2 b arranged on both sides of the surface-mount resonator 1 A are thermally connected. That is, the heating chip resistor 2 a and the power transistor 2 b are electrically connected (refer to FIG. 3A ).
In this example, the substrate-side terminal 14 to which the chip resistor 2 a and the power transistor 2 b are fixed is connected by a conductive path 14 m traversing the external bottom surface of the surface-mount resonator 1 A. For example, the conductive path below the external bottom surface of the surface-mount resonator 1 A is cross-shaped. The other end of the mount terminal of the temperature sensitive resistor is connected to the conductive path of another main surface or the layered surface of the circuit substrate 3 through a via hole 15 . It is obvious that the configuration can also be applied to the first and second embodiments.
With the configuration, as in the first embodiment, the operation temperature of the surface-mount resonator 1 A is detected by the conductive path 14 z in real time to improve the response characteristic of the temperature (heat) control for the surface-mount resonator. In this example, the conductive path 14 m which electrically connects the heating chip resistor 2 a to the power transistor 2 b traverses the external bottom surface of the surface-mount resonator 1 A and fully extends. Therefore, the radiant heat from the conductive path 14 m is applied from the external bottom surface of the surface-mount resonator 1 A. Thus, the heat source can be further effectively used.
In the above-mentioned embodiment, the surface-mount resonator 1 A has the crystal terminals 9 a at one set of diagonal portions and the dummy terminals 9 b at the other set of diagonal portions. These arrangements are optionally made. That is, at least one dummy terminal 9 b has to be connected to the temperature sensitive resistor 2 c . In addition, the dummy terminal 9 b is described as a grounding terminal connected to the metal cover 8 , but can be electrically independent as the dummy terminal 9 b according to the present invention.
Additionally, the dummy terminals 14 x of the other diagonal portions of the surface-mount resonator 1 A are connected by the metal cover 4 b , and the other dummy terminal 14 x is terminated, but only the other dummy terminal 14 x can be connected to the metal cover 4 b for connection to the grounding pattern. However, in this case, since a new surface-mount resonator 1 A is developed, each embodiment to which an existing product can be applied is more practical. Furthermore, the metal container 4 is resistance-welded, but other methods can be used. However, since a airtight seal structure is designed for the resistance welding, for example, an aging characteristic can be improved.
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A constant temperature crystal oscillator includes on a circuit substrate: a surface-mount crystal resonator which is provided with two crystal terminals as mount terminals and a dummy terminal on the bottom surface, and has a metal cover; an oscillation circuit element which forms an oscillation circuit together with the crystal resonator; and a temperature control element which keeps a constant operation temperature of the crystal resonator, in which the temperature control element includes at least a heating chip resistor, a power transistor for supplying electric power to the chip resistor, and a temperature sensitive resistor for detecting the operation temperature of the crystal resonator, wherein a dummy terminal on the substrate side of the circuit substrate for connection to the dummy terminal of the crystal resonator is connected to a resistor terminal on the substrate side to which the temperature sensitive resistor is connected through a conductive path.
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BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to a system for transporting discrete articles such as rolls of paper towels or tissue, and during the course of such transport consolidating the articles from a predetermined number of flow paths upstream from the system into a lesser number of flow paths.
2. Description of the Prior Art
It is sometimes desirable to consolidate several lines of transported discrete articles into a lesser number of lines. For example, such consolidation is necessary when downstream equipment does not have the capability of handling the same number of lines of discrete articles as upstream equipment. In the field of paper converting such a problem has been encountered wherein an orbital saw is capable of cutting three or more logs of tissue or toweling into separate rolls disposed in three lines but downstream wrapper equipment can only handle a two lane input. This has necessitated developing a simple system to consolidate the rolls into two lines during transport. Prior to this development such task was often handled manually thus adding to the labor costs involved in the production of the finished product. While consolidating machinery does exist it is characterized by its relatively high cost and complexity.
BRIEF SUMMARY OF THE INVENTION
According to the teachings of the present invention a plurality of conveyors is provided upon which the discrete articles are introduced in spaced linear relationship. To consolidate the articles into a lesser number of lines at least one of the conveyors is operated at a speed differing from the speed of the other conveyors to move the articles on the differential speed conveyor out of side by side relationship with the other articles. Diverter means is then provided for displacing the articles transported by the differential speed conveyor after they have been moved out of side by side relationship with the other articles. The displaced articles are positioned in linear aligment with the articles of adjacent conveyors thereby resulting in a lesser number of lines of moving goods.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perpective view of apparatus constructed in accordance with the teachings of the present invention;
FIGS. 2-4 are schematic plan views illustrating the operation of the apparatus in sequential stages;
FIG. 5 is an end view showing operational details of the apparatus; and
FIG. 6 is a side view of selected portions of the apparatus.
DETAILED DESCRIPTION
Referring now to FIG. 1, apparatus constructed in accordance with the teachings of the present invention is shown being utilized to transport and consolidate rolls 11 of paper product such as tissue or toweling. It will be appreciated, however, that the principles of the present invention may be applied to any discrete article. The rolls 11 are conventionally formed by being cut from elongated logs or cants 12 by means of any suitable saw equipment such as orbital saw 14 which is illustrated diagramatically in FIGS. 2-4. In the disclosed arrangement three such cants 12 are illustrated; therefore, three rows or lines of rolls 11 are formed during the sawing operation.
Wrapping equipment disposed downstream from the orbital saw is for purposes of illustration in connection with this invention presumed to be capable of handling only two lines of product. Thus, it is the function of the apparatus illustrated and to be described herein below to consolidate the three initial lines of rolls into two lines without the use of complicated equipment or manual assistance.
As the rolls 11 are fed from the orbital saw they are pushed across a platform 16 which leads to the input end of three belt conveyors 18, 20 and 22 disposed in parallel and driven by any suitable drive mechanism (not shown) so that the middle conveyor 20 is a differential speed conveyor being driven at a different speed than are conveyors 18 and 22. Conveyors 18 and 22, on the other hand, are both driven at the same speed. In the arrangement illustrated, differential speed conveyor 20 is driven at a somewhat slower speed than are conveyors 18 and 22. Thus, when the three end rolls 11 are pushed off platform 16 onto the conveyor surfaces the middle roll will be repositioned with respect to the two outer rolls. That is, from a side-by-side relationship the middle roll 11 will gradually change its position so that it registers with the gaps between the rolls on each of the two outer conveyors. After conveyors 18, 20 and 22 have accomplished this function the rolls are discharged to an independently movable conveyor stage whereat the rolls are maintained in the staggered relationship that has been established by conveyors 18, 20 and 22. This second conveyor is identified by reference numeral 28 and may comprise a unitary belt as shown or three belts equal in width to conveyors 18, 20 and 22 but driven at identical speeds so that the rolls 11 placed thereon maintain the precise staggered relationship established by conveyors 18, 20 and 22. As may best be seen in FIG. 6, second conveyor belt 28 is disposed about a plurality of support rollers, one of which, roller 30, is driven by belt 32 connected to the drive shaft 34 of a prime mover of any suitable type, which as stated above, is independent of the drive means for conveyors 18, 20 and 22.
Diverter means 40 is provided for diverting rolls 11 previously carried by differential speed conveyor 20 laterally so that the rolls are displaced into linear alignment with the rolls moved by conveyors 18 and 22. This is due to the fact that the rolls previously on the differential speed conveyor 20 are staggered relative to the rolls on the conveyors 18 and 22 and may readily be displaced into the gaps between the rolls delivered by conveyors 18 and 22. In other words, the rolls 11 are consolidated into two lanes from the original three.
The diverter means comprises a plate 42 mounted on a framework 44 that is in turn mounted for pivotal movement to a shaft 46 rotatably journalled on a suitable mounting support 47. A prime mover in the form of an air cylinder 48 is provided to effect back and forth movement of the framework 44 and plate 42 so that the plate sweeps to and fro over the central portion of second conveyor 28. A control mechanism of any suitable type is employed to actuate prime mover 48 so that plate 42 makes its move when a roll 11 disposed in the center of second conveyor 28 is in registry with the diverter means. For example, the diverter means could operate at a uniformly timed cycle corresponding exactly to the rate at which rolls 11 are introduced onto the conveyor system by orbital saw 14. It is, however, considered more reliable and more desirable to have a sensing means 50 disposed over the center of conveyor 28 to detect the presence of a roll just prior to its being placed into registry with the diverter means. One suitable sensing means that has been employed is a Banner No. CV-A 3 convergent beam proximity scanner. A suitable valving arrangement well within the capabilities of a skilled practitioner in the art would of course be controlled by the sensing means 50 to effect movement of the plate 42 in one direction for one roll and in movement thereof in the other direction for the following roll so that alternate rolls are delivered to opposite sides of conveyor 28. Conveyor 28 then delivers the two lines of rolls to a suitable delivery location such as accumulator conveyor 56 so that the rolls may be wrapped, banded or subjected to other desired operations. FIGS. 2-4 illustrate schematically the operation of the present system.
It is preferred that means be employed to maintain the rolls 11 on the various conveyors as desired. For example, referring to FIGS. 5 and 6, suitable adjustable guide rails 60 may be employed for this purpose, it being understood of course that in the vicinity of diverter means 40 no guide rails 60 would exist at the sides of second conveyor 28 to impede movement of the rolls 11 thereon by the diverter means. Rather than employ guide rails, or perhaps supplemental thereto, the conveyors themselves may be constructed in such a manner as to maintain the rolls 11 centered thereon. For example, raised flanges might be employed along the edges of the conveyors or the conveyors themselves might each comprise spaced narrow belts running in unison and defining a "pocket" therebetween to maintain the rolls 11 centered.
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A system for transporting discrete articles such as paper roll products in a predetermined number of flow lines and consolidating the articles into a lesser number of flow lines.
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BACKGROUND
[0001] Devices have been available for some time for setting a tool within a tubular such as in the downhole hydrocarbon and carbon sequestration industries. Likewise, there are devices for maintaining a tool in the set position. Though these devices work well for the purpose for which they were designed, the process for disengaging set tools and the devices that maintain the tools in the set position once the tools are no longer needed can be costly in both time and money. Disengagement of such devices from the respective tools can in some cases require running a shifting tool or a cutting tool to the device before it can be disengaged. In some cases, this might require an additional dedicated run in the hole with attendant delays and monetary costs. Those who practice in the art will therefore be receptive to methods that overcome the foregoing drawbacks.
BRIEF DESCRIPTION
[0002] Disclosed herein is a method of setting and maintaining a tool in a set position for a period of time. The method includes causing a component of a device to move relative to another component of the device, interengaging one or more features of at least one of the components with the another component, creating a set condition of a tool engaged with the component and the another component with the causing and interengaging, and when removal of the tool is desired, dissolving at least the one or more features.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
[0004] FIG. 1 depicts a cross sectional view of a portion of a setting device disclosed herein.
DETAILED DESCRIPTION
[0005] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
[0006] Referring to FIG. 1 a portion of one embodiment of a setting device is illustrated at 10 . The portion of the setting device 10 includes at least a first component illustrated herein as a mandrel 14 , a second component illustrated herein as a housing 18 and a third component illustrated herein as a body lock ring 22 . All three of the components 14 , 18 and 22 include features 24 , 30 , 34 and 38 that are interengagable with one another to allow relative movement of at least the mandrel 14 relative to the housing 18 in a first direction while preventing movement in an opposing direction. In this embodiments the features 24 , 30 , 34 and 38 are teeth. Specifically, the body lock ring 22 has the teeth 24 that face radially outwardly and engage with the teeth 30 that face radially inwardly on the housing 18 . The body lock ring 22 also has the teeth 34 that face radially inwardly and engage with the teeth 38 that face radially outwardly on the mandrel 14 . The optional body lock ring 22 is C shaped due to a longitudinal opening (not visible in the Figure) that extends longitudinally through the body lock ring 22 . This allows the body lock ring 22 to flex which action changes a radial size of the body lock ring 22 to thereby allow the teeth 34 thereon to ratchet relative to the teeth 38 when the mandrel 14 is pushed longitudinally toward the housing 18 . This ratcheting engagement, while allowing longitudinal movement of the mandrel 14 towards the housing 18 prevents movement of the mandrel 14 in a longitudinal direction away from the housing 18 thereby discouraging unsetting of the device 10 .
[0007] In an embodiment, one or more portions of the mandrel 14 , the housing 18 and the body lock ring 22 are configured to dissolve in a set time period after being exposed to a target natural or created environment. The dissolution causes the teeth 24 of the body lock ring 22 to become disengaged with teeth 30 of the housing 18 or the teeth 34 of the body lock ring 22 to become disengaged with teeth 38 of the mandrel 22 , or both. In one embodiment, the whole of the teeth 24 , 30 , 34 , 38 are configured to dissolve while in other embodiments only portions of the mandrel 14 , the housing 18 and the body lock ring 22 are configured to dissolve. More specifically, in an embodiment only one or more sets of the teeth 24 , 30 , 34 , 38 may be configured to dissolve. Proportionally to the volume of dissolvable components, the ease of removal of the tool 42 will increase. Once the teeth 24 , 30 , 34 , 38 are disengaged, the mandrel 14 and the housing 18 can move longitudinally away from one another allowing them to separate. This of course removes longitudinal compression of a tool 42 , such as a packer illustrated in the Figure, consequently releasing the packer.
[0008] The foregoing device 10 allows an operator to set the tool 42 by longitudinally compressing the tool 42 between the mandrel 14 and the housing 18 and to maintain the tool 42 in the set position for a set period of time. The period of time may be established by the time required before dissolution of at least one of the mandrel 14 , the housing 18 and the body lock ring 22 sufficiently to disengage the teeth 24 or 34 from the teeth 30 or 38 .
[0009] The mandrel 14 , the housing 18 and the body lock ring 22 can be constructed of metals and metal alloys that are configured to dissolve upon exposure to certain environments including specific fluids, temperatures and pressures, for example. The fluids can include fluids anticipated to be encountered in a downhole environment such as, oil, water, brine and combinations of the foregoing or fluids that are applied to the environment having at least a purpose of dissolving the components. As such, for applications wherein the setting device 10 is employed in an earth formation borehole 44 such as during a hydrocarbon recovery or carbon dioxide sequestration operation, for example, the dissolution of the metals can be initiated by entry into the borehole 44 . Alternately, dissolution can be initiated after exposing the setting device 10 to a selected fluid that is pumped to the location of the setting device 10 . Fluids such as acids and bases that may not occur naturally in the borehole 44 can allow additional control over timing of dissolution since the dissolution would not begin until the selected fluid is introduced to the location of the setting device 10 .
[0010] In such borehole 44 applications, among other things the tool 42 may include seals 46 , slips 50 and cones 54 to allow the setting device 10 to establish and maintain sealing and anchoring of the tool 42 to a casing 58 , liner, or other structure within the borehole 44 , for example. In applications wherein the tool 42 is a fracing plug a seat 62 can be included on the housing 18 (or the mandrel 14 ) for seating of a plug (not shown) such as a ball to allow pressure to build thereagainst to perform a treating operation such as a fracing or a formation chemical treating operation.
[0011] The material and/or the geometry of the mandrel 14 , housing 18 and the body lock ring 22 as well as the fluid to cause dissolution thereof can be selected to control a rate of dissolution. In so doing, the setting device 10 can be configured to maintain the tool 42 in the set configuration until after any operations that require the tool 42 be set are completed.
[0012] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
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A method of setting and maintaining a tool in a set position for a period of time includes the following. Causing a component of a device to move relative to another component of the device, interengaging one or more features of at least one of the components with the another component, creating a set condition of a tool engaged with the component and the another component with the causing and interengaging. The method further includes dissolving at least the one or more features when removal of the tool is desired.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of our copending commonly assigned application Ser. No. 08/179,961 filed Jan. 11, 1994.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to cellular radio systems.
2. Related Art
A typical cellular radio system includes a number of base stations linked together to form a network, the base stations being under the control of a mobile switching center which can also have a connection to a fixed network. Each base station has one or more antennas for providing radio coverage within an area around the base station. This area is known as a cell. Each base station is capable of radio communication with a number of mobile units operating in its cell.
In order to set up a call to a mobile unit, the mobile switching center sends out a paging signal to all the base stations. If the mobile unit which is being paged responds, the base station which receives the response allocates a channel, from a number of channels available to it, for communication with the mobile unit.
In a conventional cellular radio system a mobile unit does not hold on to the same resource (radio channel) throughout its call. As the mobile progresses from one cell to another within the network, handover from a resource in the old cell to another resource within the new cell is performed by switching to a new channel. This allows the mobile unit to roam over specific geographic areas without significant interruption to the communication path, while allowing re-use of released resources by other mobile units. Existing cellular radio systems are designed for use by individual mobile units making and receiving calls on a one-to-one basis, so that a mobile unit can be connected to one other mobile unit on the cellular network, or to one terminal on an interconnected fixed network (eg PSTN). When a call is set up, the mobile unit is assigned a channel (defined by e.g frequency and/or timeslot) which, for the duration of the assignment, only that mobile can use.
For some purposes, in particular in the emergency services (ESs) such as fire, police, ambulance, coastguard, mountain rescue etc., there is a requirement for a control center (the "dispatcher") to be able to call to all mobile units simultaneously (known as a "broadcast" service) or for one mobile unit to call all the others (an "all-informed" service). However, these services require access to these facilities for only a small proportion of their operational requirements. It is thus wasteful of resources to devote equipment and spectrum in the radio band exclusively to the provision of such services. Other services with field forces such as taxi and public transport operators, utilities such as gas and telecommunications companies, and dispatch companies, also have a need to communicate with several members of the field force at once.
Many of these services' other communication requirements can be met by existing cellular systems. For example, existing systems allow calls to be made between an individual mobile unit and the dispatcher, initiated by either party. However, existing cellular radio systems do not meet the requirements for the "broadcast" or "all-informed" service. It would be especially advantageous to support the requirements of the emergency services on a cellular system, because the emergency services' existing private networks have to have a high capacity to allow the system to cope with extreme situations, but this capacity is rarely required, and the system is generally under utilized.
Some cellular systems offer a supplementary service known as "multi-party calling" or "conference calling". This would allow a number of mobiles to communicate with the dispatcher and each other simultaneously. Call set-up can be initiated by any of the participants. However, multi-party calling presents some operational restrictions for the emergency services. In particular there is the need to set up calls individually; with the inherent time overhead, and the requirement for separate radio resources to be devoted to the system for each member of the multi-party call, which is wasteful of physical resources and can lead to capacity problems.
By the nature of their duties, the emergency services often have to deploy a large number of resources into a small area. This can put a heavy demand on the resources of the local base station of a cellular system if each unit requires its own channel. The base station might not be capable of meeting these capacity requirements, even if the emergency service mobiles are given priority over all other users. The nature of emergencies makes normal cell enhancement methods unsuitable for coping with these unpredictable sudden high demands.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided a cellular radio system comprising a switching center and a plurality of radio base stations each having an associated plurality of traffic channels for servicing an associated cell, and a plurality of mobile units, characterized in that for each of a plurality of the radio base stations one of the associated channels can be dedicated to a broadcast service, and a selected group of at least some of the mobile units each have means for establishing the channel associated with the broadcast service, so that a call from the switching center can be transmitted by a base station over the dedicated channel to the selected group of mobile radio units within the respective cell.
In one embodiment of the invention, each base station within the cellular system has a channel permanently dedicated to the broadcast service. In an alternative embodiment each base station comprises means for transmitting a paging signal, each mobile unit of the selected group having means for transmitting a response to the paging signal, and means for dedicating a channel to the broadcast service at only those base stations which receive one or more such responses.
According to a second aspect of the invention, there is provided a cellular radio system comprising: a switching center and a plurality of radio base stations each having an associated plurality of traffic channels for serving an associated cell, and a plurality of mobile units, characterized in that for each of a plurality of the radio base stations one of the associated channels can be dedicated to a broadcast service, and a selected group of at least some of the mobile units each have means for establishing the channel associated with the broadcast service, so that a call from the switching center can be transmitted by a base station over the dedicated channel to the selected group of mobile radio units within the respective cell, each base station comprising means for transmitting a paging signal and means for dedicating a channel to the broadcast service at only those base stations which receive one or more responses to the paging signal, each mobile unit of the selected group having means for transmitting such a response to the paging signal.
In this arrangement, it is advantageous to provide means for repeating the paging signal periodically throughout a broadcast. It can be arranged that the channel dedicated to the broadcast service may then be released if no mobiles continue to respond to the repeated paging signal in a particular cell. Moreover, it can be arranged that a channel to be allocated part of the way through a broadcast if a mobile enters a cell in which there are no others already present.
The plurality of base stations from which the broadcast service can be transmitted may be selected according to the area of coverage required, for example administrative district covered by the user of the broadcast service.
In a preferred embodiment there is the facility for a broadcast to be initiated from one of the mobile units, to provide the "all-informed" service described above. The term "broadcast" as used in this specification hereinafter embraces such a service.
Means may be provided for supporting a plurality of broadcast services to different groups of mobile units, arranged such that for each of a plurality of the base stations one of the associated channels can be allocated to each broadcast service. This allows several broadcast services for different user groups to be supported at once. Different groups of the base stations may support different groups of the broadcast services to allow for different but overlapping geographical coverage requirements.
For some embodiments the use of conventional mobile radio handset units may be possible. For example, in systems in which broadcast service is initiated by paging, the units may have means to allow them to respond to a special broadcast service paging signal, but alternatively, the system may simply identify the unit as being one subscribing to the broadcast service by matching its identification code with, for example, an additional look-up table in that part of the system which identifies whether a mobile unit is authorized to use the cellular network. However, for many of the preferred arrangements, described below, specially adapted radio units may be required.
In an embodiment in which a single channel is permanently allocated to the broadcast system, it is advantageous for mobile radio units for use in that system to have means to monitor the broadcast channel while they are operating on another channel, (e.g. in normal cellular mode), and are arranged to switch to the broadcast channel if traffic is detected on that channel. Where a broadcast may be initiated from one of the mobile units, it is advantageous for the units to include means for inhibiting transmission by the unit on the broadcast channel if other traffic is detected on that channel, to ensure that only one unit is broadcasting at a time. Moreover, if the unit were to continue receiving at the same time as it is transmitting on the broadcast channel echo effects and/or feedback howl could be caused. It is therefore advantageous to include means for inhibiting reception by the unit when it is transmitting on the broadcast channel.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will be described with reference to the drawing, which schematically represents a cellular radio system of the embodiment of its coverage area for broadcast purposes.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
This coverage area consists of three cells, (Cell 1, 2 and 3) which form part of a larger cellular network (indicated by dotted lines in the figure). In each cell, there is a base station system (BSS) for establishing radio contact with the mobile units (Ma, Mb etc) within the cell.
A mobile switching center (MSC) controlling the cellular network has associated with it a home location register (HLR) and visitor location register (VLR) as is conventional in cellular systems such as the GSM Pan-European digital cellular system.
The operator of the broadcast service, typically a dispatcher for an emergency service, has a control point which has a link to the Mobile Switching Center. The control point may be co-located with the mobile switching centre, but will usually be elsewhere.
The two embodiments to be described with reference to the drawing differ in the method by which channels are allocated to support the broadcast service. The first uses a fixed or dedicated broadcast channel, and the second uses a flexible broadcast channel allocation.
These broadcast channels must not be confused with a broadcast control channel, in GSM known as BCCH; which provides control signalling information for the cellular network as a whole. In particular, the broadcast control channel provides the paging function required in order to identify the location of a mobile unit when an incoming call for that unit is made. These control channels are merely signalling channels carrying signalling data. The broadcast channels in this invention are additional to this, and in normal circumstances carry speech.
In the FIGURE the three cells 1, 2 and 3 represent the coverage area in which the mobiles subscribing to the broadcast service are intended to operate. They might, for example, represent the area covered by a single police force. The network as a whole may provide broadcast services for more than one service, for example, police forces in adjacent areas. Moreover, different emergency services may have their own broadcast services within the same area, or overlapping areas, each one being allocated its own channel, or its own paging signalling. Each of the cells 1, 2 and 3 has a base station, identified as 11, 12 and 13 respectively and there are a number of mobile units identified Ma, Mb, Mc, Md, Me and Mf which can roam throughout the cellular network. The dispatcher or control point is identified by Mx.
Considering the fixed broadcast channel embodiment first, each base station has an allocated emergency channel, having a specified frequency (Fx, Fy, Fz) and time slot (Ta, Tb, Tc). A mobile unit forming part of the broadcast system will be set to continually monitor this channel. The mobile units can also operate in the same way as normal mobile units, ie. they are able to make and receive point to point calls. As mobile units (Ma-Mf) roam through the policing area, each unit monitors the respective broadcast channel for the cell it is in. The broadcast channel is identified over the broadcast control channel, which a mobile unit normally monitors for paging information and other control data, so that as the mobile unit passes from one cell to another the broadcast control channel information will direct it to monitor the broadcast channel of the new cell. Alternatively instead of being directed by the control channel, the mobile unit may be arranged to tune to the broadcast channel offering the best level of quality, ie. the highest signal level.
When the dispatcher at control point Mx is required to make a broadcast, he selects the broadcast area in which he wishes the call to be made (which may be just one cell, or all cells, or any subset of the whole), and then broadcasts the message. Those mobile units in their idle state are already tuned to the broadcast channel in the selected areas, so they are immediately capable of receiving calls. Any mobile units involved with point-to-point calls are informed that a broadcast call is starting so that they can also tune to the broadcast channel. This broadcast call indication can be arranged to cause any such point-to-point calls to be terminated automatically, or it may allow the user operating the mobile unit to select whether to listen in to the broadcast call or continue with the point-to-point call.
When the broadcast is finished, the dispatch centre will release the call, and the mobile unit returns to monitoring the broadcast channel.
Normally mobiles in a cellular system are required to perform a location update when entering a new location area or at predetermined intervals. Location areas are specified by the network operator and location area information is broadcast to all mobiles over the broadcast control channel. The mobiles normally retain location information and compare it with subsequently received information to determine whether a location update is required. In particular, if the location information broadcast over the broadcast channel has changed, this is indicative that the mobile unit is now within range of a different base station.
The handover process for the broadcast channel operates entirely within the mobile unit, which determines which cell is going to provide the best level of service, based on measurements either of the broadcast channel or of the control channel taken within the mobile unit. If the mobile unit roams outside the broadcast area altogether (ie. in FIG. 1 outside cells 1, 2 and 3, for instance into cell 4) then it will drop out of any broadcast call.
The mobile unit may of course still communicate with its own dispatcher (or any other dispatcher) by virtue of still being within the conventional cellular network. This is an advantage over existing private mobile systems, which have no out-of-area capability.
A mobile unit, on performing location update, will pass its identity to the network, which is then used to determine the home location register (HLR) address to which the VLR (Visitor Location Register) has to pass the location update information. The Home Location Register, on receiving the update, will pass service information back to the new VLR and delete all previous entries for that mobile at any previous VLR.
Where a generic broadcast identity is used the emergency service mobiles should not use it for location updating, instead they use their own specific identity. The HLR has a permanent VLR address entry stored in it for the broadcast service which covers the broadcast area, i.e. there is a fixed relationship between the broadcast area and the broadcast identity, VLR and HLR. Generally, all the information is pre-stored in the HLR without any need to download to the VLR.
The broadcast areas can be tailored to fit the individual Emergency or other Service operating areas. This has the advantage of reducing location update information and provides a means of indicating to the mobile that it is out of the broadcast coverage area, and reducing the signalling overhead by not transmitting paging signals in those cells where a mobile unit should not be found. The area may be an administrative district, such as a Police Authority's jurisdiction, or may be selected according to the nature of the user; for example limiting the broadcast to only those cells covering the routes operated by a public transport operator.
The cellular system can support conventional mobile units (not equipped to monitor the emergency channel) without modification. The presence of the emergency channel will have no effect on these units whatsoever.
If it is desired to use encryption in the broadcast channel, a facility which is particularly useful for the emergency services, this can be provided comparatively easily in the fixed channel system. The encryption algorithm may be carried out over the air interface, for example to allow the fixed channel allocated to be changed on a predetermined basis known only to the operating system and encryption software in the mobile units. Alternatively, the emergency services may prefer to run their own encryption algorithm end to end, with no further encryption over the air interface.
Although the fixed broadcast service describe above has a number of advantages, a particular disadvantage with providing such a system is that resources (in particular a radio channel) have to be permanently reserved within each cell in the broadcast area whether or not they are actually being used. The flexible option now to be described moves away from a permanent, fixed allocation, to one which is demand allocated. This allows more efficient use of the resources in the broadcast area, at the expense of some greater complexity. Since emergency services in particular are likely to be allocated the highest degree of priority there should be no problems in making a channel available for the broadcast service, even if this means an existing point-to-point call has to drop out.
To provide a flexible broadcast channel each mobile unit is allocated two identifies; namely the unique identity which can be used for individual calls, as a standard cellular mobile unit, and an operational group identity for broadcast calls.
The basic operation of the mobile unit remains the same as in standard cellular practice in that the mobile unit is able to make and receive point-to-point calls. To set up a broadcast call a broadcast group identity is paged by all the base stations 11, 12, 13 in the broadcast area. Each mobile unit operating in the broadcast area which has that broadcast group identity responds to the base station as to a normal page. The first unit in each cell to respond is allocated a channel e.g. (Fx/Ta in Cell 1). Should there be another mobile unit in the same cell (e.g. Mb), it is instructed to tune to the same channel. In this way only one channel is required for each cell, as in the previous embodiment. However, unlike the previous embodiment, if no mobile responds in a particular cell, no channel is allocated in that cell.
This approach is more efficient in use of resources than the fixed mode, because it only requires the use of a channel in those cells in which there are mobile units subscribing to the broadcast system.
If, at the time of paging, one of the emergency service mobiles is engaged on a point-to-point call, that call will be terminated. The channel allocated to that call can then be used for the broadcast service. If no emergency service mobile is currently engaged on a point-to-point call a free channel is allocated, or if none are free, one is seized from a lower-priority call. Ideally, a warning message will warn the callers that this is about to happen, and why.
Once the physical channel has been determined, the base station will set up a connection to the mobile switching center. Each base station involved in the broadcast area is connected to the dispatch center Mx via the switching center MSC, where there will be a multiple connection conference bridge for interconnecting the traffic service to the dispatcher. This conference bridge does not need to be as complex as it would be for a conference between all the mobiles working independently in a conventional manner, since only one connection to the bridge per base station instead of one per mobile is needed.
The mobile units have their transmitters disabled while the service is running, so a base station will not get any information on the unlink from the mobile unit. This means that the mobile will not receive any power control or timing advance information.
When the broadcast facility is no longer required, the dispatcher releases the call which stops the paging and releases the resources at each cell in the broadcast area. The mobile units can then resume normal cellular operation.
In this second embodiment, handover arrangements are somewhat different from those in the first embodiment. As a mobile unit, for example Mb, moves from the coverage of the broadcast channel in cell 1, it will normally drop out of the broadcast group in that cell. This drop out decision is taken by the mobile unit and is based on quality of service measurement. Conventional handover techniques cannot be used in this situation, because in the broadcast service the movement of a mobile between cells does not necessarily require the allocation of a new channel in the new cell or the release of one in the old cell (as it would in a conventional handover) since other mobiles may be present in either or both cells. Instead, the paging procedure is repeated at intervals throughout a broadcast call. Should a mobile respond in a cell to which no channel is currently allocated (i.e. it has entered an empty cell) a channel will be allocated. A mobile unit may miss initial page attempts for the broadcast service, but an appropriate repetition rate will minimize the level of speech loss which could occur while the mobile is finding the new channel. This handover process can be speeded up by using the broadcast control channel to broadcast the physical channel data for each active cell in the broadcast group to the mobiles.
If no mobiles respond to a page repetition from a base station then it may be assumed that there are no longer any mobiles in the cell and the channel can be released. However, because of the possibility that a mobile is still in the cell but has missed a paging attempt the channel is only released after a number of successive paging attempts fail to get a response.
When the broadcast facility is no longer required then the broadcast center releases the call which stops further pages and releases the resources at base stations and mobiles.
The location management is similar to that in the fixed channel embodiment described above.
Encryption may be provided in the flexible broadcast embodiment in the same manner as described under the fixed channel embodiment described above. Alternatively there may be a more flexible approach, more in tune with the way in which conventional cellular systems operate.
This approach requires that the broadcast service mobile units Ma to Mf are first authenticated over a dedicated signalling resource before the mobile is permitted to move to the shared physical channel. In much the same way as in standard cellular radio encryption systems the encryption key is generated from a random number during the authentication process. The mobile responds to the visitor location register with a response which is then checked before encryption begins. However, it must be noted that all elements in the system have to use the same random number and generate the same encryption key for each mobile in a serving cell so that they can share the same physical channel. The allocation of the special group identity must also be supported by the same allocation of a secret key, otherwise a different response will be returned to the VLR and a different encryption key generated for each member of the group.
There may be a requirement to provide the broadcast service in specific geographical areas, for example different police force areas. This could be provided through tailoring of the paging to certain base stations only. In general the paging area is pre-defined by the operator and managed by the VLR. This means that for all calls, the same base stations are used for paging. If, however, a link is made between the mobile station identity and the paging area in the VLR it would be possible for an operator to provide paging for specific identities only when they are in specified areas. Thus the flexible mobile system has the advantage of being a more efficient use of channel resources in the cellular radio system, at the expense of some complexity and a slower response time for call set-up and handover.
Either system described above can support an "all-informed" service, in which a message from a mobile Ma can be heard by all others. The call set-up is as described above, except that it is initiated from mobile Ma instead of the control point Mx. Mobile Mb will therefore be allocated the same channel as Ma because it is in the same cell. In order to avoid the delayed speech being heard by the speaker, the mobile Ma making the transmission must have reception inhibited. The mobile units Ma, Mb, Mc, Md, Me, Mf are designed so that transmission is inhibited if any traffic is detected on the channel, so that only one mobile can transmit at once.
The mobile unit must determine a timing advance, in order to transmit on the up-link portion of the broadcast channel. A random access burst is passed to the base station on the uplink of the broadcast channel, and a timing correction is calculated and passed to the mobile by means of the downlink portion of the broadcast channel. Once timing correction has been attained the mobile unit can then transmit. The transmitting mobile's speech can be retransmitted in the downlink broadcast channel provided that a conference facility is available in the operational control room. The mobile which is transmitting must inhibit its own receiver to prevent reception of its own speech after a time delay. While the mobile is transmitting on that channel the other mobile units are inhibited from making broadcasts because traffic is detected on the channel. This can be achieved most easily by providing a "press to talk" button on the mobile unit. The "press to talk" button will allow the mobile unit to transmit (provided that no other mobile or the dispatcher is already transmitting on the channel) and inhibit reception.
One mobile switching center could support more than one broadcast network, which may cover different broadcast areas (e.g. different police authorities) or may have overlapping broadcast areas (e.g. fire, police and ambulance services within the same area).
The invention therefore allows a broadcast facility to be provided to or between a number of mobile units within a cellular system. General traffic can be carried on the same system in a conventional manner.
Although the broadcast service has been described with reference to use by the emergency services, the facility could also be provided for other users who require similar facilities such as taxi operators, parcel couriers, railway operators etc.
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In a cellular radio system the facility is provided for a call to be broadcast from a control center (for example an emergency service controller), or from any mobile unit to all of the others. Each cell allocates a single channel to the broadcast service, irrespective of the number of mobile units in the cell. This allows more efficient use of the available channels than the use of a separate channel for each mobile unit. In one embodiment no channel is allocated to a cell unless at least one mobile unit responds to a paging signal in that cell. Paging may continue throughout a broadcast call to allow a channel to be allocated when a mobile unit enters a previously unoccupied cell or to allow release of a channel should all mobiles leave a previously occupied cell. The broadcast facility can be provided on a cellular network which also supports other mobile units which do not receive the broadcast service, and whose operation is not affected by it.
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TECHNICAL FIELD
The invention relates to isocyanate-free premier compositions for glass and glass ceramics in order to improve the adhesion of an adhesive or a sealant.
STATE OF THE ART
Adhesives, coatings, sealants, floorings and other systems are based on the reactive binders. The adhesion of these reactive systems to diverse substrates is often unsatisfactory. Therefore, often the so-called “primers” are used. A primer forms an adhesion bridge between the substrate and the used binder. A primer is also a chemically reactive system and is applied on the substrate.
In order to obtain a set-up of adhesion of the primer with the substrate, the primer must be provided with a definite time, the so-called “flash off time”, in order to form a film and at least to partially cross-link before the adhesive or any other reactive system can be applied. However, the application of this system is restricted during the so-called “open time” during which the adhesion to the primer is ensured. An adhesion to the primer is no longer ensured on exceeding the open time. Open time is thus determined in tests in which variably long period between the application of the primer and the adhesive is maintained and the adhesion of the bonds after hardening of the adhesive is determined. As a model the adhesion between the primer and the adhesive or another reactive system is formed by a reaction between these materials. The ventilation time must be as short as possible in an industrial application in order to ensure a fast and cost-effective processing. This means that the adhesion set-up of the primer with the substrate must be as fast as possible so that an application of an adhesive or any other reactive system can be done as fast as possible. However, in doing this, the problem of interruption in the production process occurs because of, for example, technical defects, end of shift or weekends, so that a longer period of a few hours to days or even weeks can elapse between the application of the primer and the application of the adhesive or any other reactive systems. This is especially disturbing in continuously running industrial applications. Moreover, the trend in automotive engineering is to shift the pretreatment away from the industrial assembly line into the factory of the supplier so that an open time of up to a few weeks could elapse between the applications of the primer in the factory of the supplier to the application of the adhesive in the production factory.
There is a great demand for primers having long open times in order to also ensure a good adhesion in these cases.
Glass and glass ceramics are extremely important substrates for the bonding technology, particularly in automotive engineering. Traditionally, primers based on isocyanates are used for this. On the one hand isocyanates are regularly the topic of controversial discussion concerning toxicity, and on the other hand, isocyanates are reactive substances. In particular, they react with the atmospheric humidity so that the number of free isocyanate groups is very considerably reduced within a short time after application of an isocyanate primer. Therefore, normal isocyanate-based primers are generally suitable only for short open times.
U.S. Pat. No. 4,963,614 describes a primer for glass which contains a silane and a polyisocyanate, a film-forming component as well as carbon black. However, the silane-polyisocyanate reaction product disclosed therein is not provided with an isocyanate-reactive group, which infers to poor adhesion characteristics with polyurethane adhesive applied on it, particularly after cataplasma storage. No data is provided on the open time of these primers.
U.S. Pat. No. 5,109,057 describes a primer which is produced from a polyurethane pre-polymer which is carrying isocyanate groups and a silane consisting of NCO-reactive functional groups. This primer seems to exhibit an improved UV-stability. No data is provided on the open time of these primers.
WO 02/059224 A1 describes a two-component primer, which comprises a curing agent comprising of an adduct of an alkoxy silane and a polyisocyanate having a mean NCO-functionality from 2.5 to 5.0 and an isocyanate content from 8 to 27 wgt.-%, and a lacquer resin reactive to the isocyanate groups as the second component. However no primary amino silanes are disclosed as alkoxy silane.
With the state of art it is not possible so far to obtain an isocyanate-free primer which exhibits a good adhesion to glass and glass ceramics and a long open time.
DETAILED DESCRIPTION OF THE INVENTION
The task of the invention is to overcome the described disadvantages and problems of the primer for glass and make available a primer which also exhibits a good adhesion to glass and glass ceramics and a long open time. It was unexpectedly found that the disadvantages of the state of the art could be eliminated by the inventive primer composition according to claim 1 . At the same time a good adhesion at short flash off times, respectively at short waiting times between the application of the primer and the adhesive, is ensured.
Methods for Realization of the Invention
The present invention relates to a primer composition comprising a compound A1 which contains isocyanate-reactive groups. A polyisocyanate A, comprising at least three isocyanate groups, as well as at least one silane B of the formula (I), as well as a cross-linking agent C having three isocyanate-reactive functional groups are used for producing this compound A1.
Molecules which comprise formally two or more of the respective functional groups are designated in the entire document by the prefix “poly” in “polyisocyanate” and “polyol”.
By the term “isocyanate-reactive functional groups” those chemical functional groups which react with an aliphatic or aromatic isocyanate group at room temperature or at temperature of up to 100° C., if necessary in the presence of a suitable catalyst, are understood.
The polyisocyanate A, used for producing compound A1, has at least 3 isocyanate groups. In particular 3, 4, 5 or 6, preferably 3 or 4 isocyanate groups are present.
These polyisocyanates are preferably low-molecular polyisocyanates having a molecular weight of less than 2000 g/mol, particularly less than 1000 g/mol. The molecular weight preferably is between 400 and 900 g/mol.
On the one hand such low molecular polyisocyanates are the diisocyanate-polyol-adducts which are produced by the reaction of low molecular polyols with diisocyanates in excess of the diisocyanate leading to a NCO-functionality of three or more. Examples of such diisocyanate-polyol-adducts are those from a polyol, as mentioned further below as cross-linking agent C, and an aliphatic or aromatic diisocyanate. In particular to be mentioned are adducts from trimethylolpropane, glycerol or pentaerythritol as polyol and HDI, TDI or IPDI as diisocyanate.
On the other hand, they are low molecular oligomers or polymers of diisocyanates. For example it is here with polymeric MDI (4,4′diphenylmethandiisocyanate), such as for example the one which is commercially available as Voranate M-580 (Dow).
Particularly suitable are the low-molecular polymers of the monomers
HDI, for example commercially available as Desmodur N-3300 (Bayer), Desmodur N-3600 (Bayer), Luxate HT 2000 (Lyondell); or as Desmodur N-100 (Bayer), Luxate HDB 9000 (Lyondell); IPDI, for example commercially available as Desmodur Z 4470 (Bayer), Vestanat T 1890/100 (Hüls), Luxate IT 1070 (Lyondell); TDI, for example commercially available as Desmodur IL (Bayer); TDI/HDI.
In particular, they are biuretes and isocyanurates, preferably of low molecular diisocyanates. Diisocyanates particularly suitable for this are 2,4- and 2,6-toluylenediisocyanate (TDI), 4,4′-diphenylmethanediisocyanate (MDI) as well as its positional isomers, hexamethylendiisocyanate (HDI), 2,2,4- and 2,4,4-trimethyl-1,6-hexamethylenodiisocyanate, tetramethoxybutane-1,4-diisocyanate, butane-1,4-diisocyanate, dicyclohexylmethanediisocyanate, cyclohexane-1,3- and 1,4-diisocyanate, 1,12-dodecamethylenediisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocynatomethylcyclohexane (=isophorondiisocyanate or IPDI), as well as the hydrogenated compounds of the said aromatic compounds. Obviously, mixtures of diisocyanates are also possible for producing biuretes and isocyanurates.
The polyisocyanate A is preferably an isocyanurate or a biuret of monomers selected from the group consisting of HDI, IPDI, TDI and mixtures thereof. It is especially an isocyanurate of HDI.
The silane B used for producing compound A1 has the formula (I).
In formula (I) R 1 represents methyl or ethyl. Furthermore, R 2 represents a H, a C 1 - to C 4 -alkyl or OR 1 and R 3 represents a H, a C 1 - to C 4 -alkyl or OR 1 . X(1) denotes an isocyanate-reactive group or an organic residue carrying isocyanate-reactive groups and is a primary amino group or an organic residue which has at least a primary amino group. Preferably X(1) is NH 2 .
Preferably R 1 represents methyl. More preferred is R 3 ═OR 1 and even more preferred is R 3 ═R 2 ═OR 1 .
Examples for suitable silanes B of the formula (I) are:
3-Aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropyldimethylethoxysilane, N-(2-aminoethyl)-3-aminopropylmethydimethoxysilane, N-(2-aminoethyl-3-aminopropylmethyldiethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane. 3-aminopropyltrimethoxysilane is preferred.
In one embodiment of the invention in addition to the silane of the formula (I) at least another silane of the formula (I′)
is used for producing compound A1.
In formula (I′) R 4 represents methyl or ethyl. R 5 also represents a H, a C 1 - to C 4 -alkyl or OR 4 and R 6 a H, a C 1 - to C 4 -alkyl or OR 4 . X(2) represents an isocyanate-reactive group or an organic residue carrying isocyanate-reactive groups and is a primary amino, mercapto or hydroxylic group or an organic residue which comprises at least one primary amino, mercapto or hydroxylic group. X(2) is preferably SH or NH 2 .
Preferably R 4 represents methyl. R 5 ═OR 4 is also preferred, more preferred is R 6 ═R 5 ═OR 4 .
Examples for suitable silanes B of the formula (I′) are:
3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethyoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropyldimethylethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, N-aminoethyl-3-aminopropylmethyldiethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, mercaptopropylmethyldiethoxysilane. 3-Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane or 3-mercaptopropyltrimethoxysilane are preferred.
If several silanes are employed then these can be used as mixture or can be used at different points in time during the production of A1.
Particularly preferred are different silanes B. The two silanes, 3-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane, are preferably used for producing compound A1.
The cross-linking agent C used for producing compound A1 has at least three isocyanate-reactive groups. These isocyanate-reactive groups can all be identical or independently different from one another. It is preferred that all groups are identical. The isocyanate-reactive groups are especially selected from primary amino group (NH2), secondary amino group (NH), mercapto group (SH) or hydroxyl group (OH). A mercapto or hydroxylic group is preferred.
At least three isocyanate groups are present, but can also be more, especially 3, 4, 5 or 6. 3 or 4 are preferred.
In case of the cross-linking agent C is preferably a polyol, particularly a triol.
The cross-linking agent C preferably has a molecular weight of 90-1000 g/mol, particularly 90-500 g/mol, preferably 120-150 g/mol. It has advantageously an equivalence weight of 30-350 g/eq, particularly 30-170 g/eq, preferably 30-65 g/eq, related to the isocyanate-reactive functional group which in case of a polyol is the OH-equivalence weight.
Higher molecular weights, respective equivalence weights, are less advantageous because this frequently leads to poor film properties, high viscosities or poor shelf life of the primer.
The cross-linking agent is, for example, pentaerythrite (=2,2-bis-hydroxymethyl-1,3-propanediol), dipentaerythrite (=3-(3-hydroxy-2,2-bis hydroxymethyl-propoxy)-2,2-bis-hydroxymethyl-propane-1-ol), glycerol (=1,2,3-propantriol), trimethylolpropane (=2-ethyl-2-(hydroxymethyl)-1,3-propanediol), trimethylolethane. (=2-(hydroxymethyl)-2-methyl-1,3-propanediol, di(trimethylolpropane) (=3-(2,2-bis-hydroxymethyl-butoxy)-2-ethyl-2-hydroxymethyl-propane-1-ol), di(trimethylolethane) (=3(3-hydroxy-2-hydroxymethyl-2-methyl-propxy)-2-hydroxymethyl-2-methyl-propane-1-ol), diglycerie (=bis-(2,3-dihydroxypropyl)-ether), triglycerine (=1,3-bis-(2,3-dihydroxypropyl)-2-propanol; thioglycerine (=mercapto-1,2-propanediol), 2,3-dimercapto-1-propanol; triethanolamine (=tris-(2-hydroxyethyl)-amine) or triisopropanolamine (=tris-(2-hydroxypropyl)-amine).
The cross-linking agent C, trimethylpropane, is particularly preferred.
The compound A1 can be produced in different ways. In particular the compound A1 can be obtained by the reaction of a cross-linking agent C with an intermediate product AB which is previously formed from a polyisocyanate A and at least one silane B of the formula (I) in a stoichiometric excess of the isocyanate groups of the polyisocyanate A in relation to the isocyanate-reactive groups of silane B.
Such a production method is illustrated, for better understanding, by means of the following reaction scheme simplified for a preferred case. However, this represents only an exemplary representation and cannot cover all the possible variants which can be produced particularly by different number of the reaction partners and stoichiometry.
Two molecules B are shown in this example. The application of different symbols for the residue shall illustrate that the residues can vary in the formula (I). Therefore X(1) and X(2) correspond to the possible residues according to formulas (I) and (I′).
R represents the polyisocyanate A after removal of all the isocyanate groups. Y represents an isocyanate-reactive group of the cross-linking agent C and R′ the cross-linking agent C after removal of all the isocyanate-reactive groups. X 1 , respectively X 2 , respectively Y 1 , represent the functional group which is produced from the reaction of X(1), respectively X(2), respectively Y, with isocyanate, i.e. particularly an urea, urethane or thiocarbamate group.
The indices n, respectively q, indicate the number of isocyanate groups of polyisocyanate A, respectively isocyanate-reactive groups of the cross-linking agent C, and correspond to the values already described for these.
Moreover, p, respectively n−p−1, indicate as to how many isocyanate groups of polyisocyanate A are bonded with silane B of variable type by forming the intermediate product AB. The index p can assume values between 0 and n−1. One of the silanes B is merely bonded to the polyisocyanate A in the cases p=0 and p=n−1.
The intermediate product AB can comprise one or several non-reacted isocyanate groups. However, it is preferred that the intermediate product AB has only one free isocyanate group. Such a case is indicated in the above reaction scheme. If several free isocyanate groups remain in AB, as is the tendency, this leads to higher molecular species and thus to higher viscosities.
Finally index m indicates as to how many free isocyanate-reactive functional groups the compound A1 has. The index m particularly assumes the values 1, 2, 3, or 4, that is depending on q wherein q−m≧2. It is preferably 1 or 2. m=1 is considered as particularly preferential.
The intermediate product AB can be produced by the participation of at least one silane B. But several silanes B can also participate, particularly 2 or 3. The intermediate product AB is preferably produced from two different silanes B. These two silanes of the formula (I) have different isocyanate-reactive groups X(1) and X(2).
If several silanes B are used then these silanes can be directly used as mixture in the production or successively added. It appeared particularly suitable if at first one silane is added and a second or further silane is added to the reaction partner in a further step.
The compound A1 has at least one isocyanate-reactive functional group. Several such groups are possible. In particular it deals with 1, 2, 3 or 4 such groups, preferably 1 or 2 such groups, particularly preferred 1 such group. The isocyanate-reactive group it particularly a primary amino group (NH 2 ), secondary amino group (NH), mercapto group (SH) or hydroxyl group (OH). Preferably it is a mercapto or hydroxylic group. If the compound A1 has several such groups then these groups can all be same or different from one another.
On the one hand it is desirable that the compound is cross-linked by the cross-linking agent C. On the other it is desirable that not only the primer composition but also the compound A1 no longer contains essentially any free isocyanate groups, i.e they are essentially NCO-free.
Both can be controlled by the stoichiometric ratios in the reaction of the intermediate product AB with the cross-linking agent C. Therefore, it is particularly necessary that the isocyanate-reactive groups of the cross-linking agent are in the stoichiometric excess with regard to the isocyanate groups of the intermediate product AB. For this the relation r is defined as follows:
r
=
Equivalent
NCO
-
reactive
groups
(
C
)
Equivalent
NCO
-
reactive
groups
(
A
)
-
Σ
Equivalent
NCO
-
reactive
groups
(
B
)
The relation r amounts to the values of >100%. The upper limit represents that value at which formally a 1:1 adduct is formed between the cross-linking agent C and the intermediate product AB, i.e. in which the cross-linking agent no longer plays any cross-linking function. Therefore, the value of r should be clearly lower than this upper limit so that essential components of the cross-linked species are present. If too many 1:1 adduct molecules are present, then the stability of the primer is strikingly poor. The component of 1:1-adducts should not be more than 20% related to A1. Therefore the value of r has also a very high influence on the number of free isocyanate-reactive groups of the end-product A1.
The person skilled in the art understands that, in addition to the compound A1, also such products in which free isocyanate-reactive groups are no longer present are formed on the one hand, as well as non-bridged reaction products, i.e. 1:1 adducts of the cross-linking agent C and intermediate product AB, are also formed on the other hand. However, it should be considered that the amount of these by-products is as little as possible.
The values of r are between >100% and <300% for the specially preferred case in which the cross-linking agent C is a tri-functional molecule and the intermediate product AB contains one free NCO-group.
Here, the values of 105%-200%, preferably values of 105-150%, are to be particularly selected, to obtain a cataplasma-stable primer.
A specially preferred embodiment of the primer composition contains a compound A1 which is produced from an isocyanurate of the formula (II) or a biuret of the formula (IIa), two silanes of the formula (III) and (IV), and trimethylolpropane (V).
whereby the residues R 1 , R 2 , R 3 , R 4 , R 5 and R 6 represent the already defined residues. R″ is a divalent residue and particularly represents an aliphatic alkene residue, preferably the hexamethylene residue.
The intermediate product AB is preferably produced in a two-step process, particularly in which the mercaptosilane is used at first in a first step and the amino silane is used in a second step.
The compound A1 thus produced may be represented by the formula (VI) and formula (VII).
The compound A1 has at least one isocyanate-reactive functional group. Several such groups are possible. It particularly deals with 1, 2, 3 or 4 such groups, preferably 1 or 2 such groups, particularly preferred 1 such group. The isocyanate-reactive group is preferably selected from a primary amino group (NH 2 ), secondary group (NH), mercapto group (SH) or hydroxyl group (OH). A mercapto group (SH) or hydroxyl group (OH) is to be particularly preferred. If the compound A1 has several such groups then these groups can all be the same or different from one another.
The person skilled in the art understands that, in addition to the compound A1, also such products in which free isocyanate-reactive groups are no longer present are also formed on the one hand as well as non-bridged reaction products, i.e. 1:1 adducts of the cross-linking agent C and intermediate product AB, are also formed on the other hand. However, it should be considered that the amount of these by-products is as little as possible.
In an embodiment the primer composition also comprises at least one solvent LM1 which is inert to isocyanates at room temperature. This solvent is used preferably already for producing of compound A1, respectively of the intermediate product AB. The solvent can get into the primer formulation, if necessary, only after the production of compound A1. The solvent is a volatile solvent and, in addition to the aromatic solvent like xylene, toluene, mesitylene, particularly comprises esters, specially acetates and ketones. The solvent is particularly selected from the group consisting of xylene, toluene, acetone, hexane, heptane, octane, methylethyl ketone, methylpropyl ketone, methylisopropyl ketone, methylbutyl ketone, dieeethyl ketone, diisopropyl ketone, methylacetate, ethylacetate, propylacetate, butylacetate, methoxyethylacetate, methoxypropylacetate and 2-(2-methoxy-ethoxy)-ethylacetate. These solvents are preferably used in mixtures.
Further solvents LM2 can be added to the primer after producing compound A1. These solvents can also be reactive to isocyanates. They are preferably slightly volatile solvents having a boiling point of less than 100° C. Alcohols such as methanol, ethanol, propanol, isopropanol and sec. butanol are particularly suitable for this. Isopropanol is particularly suitable.
Solvents are mainly used for reduction of the viscosity as well as for optimization of the flash off behavior.
Moreover the primer composition may contain the coupling agent HV. Titanates, zirconates or silanes represent exemplarily such coupling agents. In particular they are preferably silicon-organic compounds. On the one hand the said silanes B as well as 3-glycidyloxypropyl-trialkoxy silanes, methacryloxypropyltrialkoxy silanes as well as vinyltrialkoxy silanes are the preferred silicon-organic compounds.
Trialkoxy silanes are particularly preferred. It appears that this additional coupling agent is advantageously a trialkoxy silane comprising a primary amino group, particularly a trimethoxy silane comprising a primary amino group, or a trialkoxy silane consisting of a vinyl group.
Moreover, the primer composition can also contain a catalyst KAT, particularly a tin-organic catalyst. These catalysts are normally polyurethane catalysts. The tin-organic catalyst is preferably selected from the group consisting of dibutyltindilaurate, dibutyltindichloride, tinthioester complexes, mono-n-butyltintrichloride, di-n-butyltin oxide, di-n-butyltindiacetate and dibutyltincarboxylate.
Moreover, the primer composition can contain of a filler F, like for example silica, talc, chalks and carbon blacks. A specially preferred filler is carbon black.
Moreover, commonly used additives in the primer chemistry can be used. Examples of unlimited type for this are UV- and heat stabilizers, flow-control agents, film formers, thixotroping agents as well as chemical and physical drying agents.
A specially preferred embodiment of a primer composition comprises, in addition to the compound A1, at least one solvent LM1, at least one coupling agent HV, a catalyst KAT as well as carbon black as filler F.
The described composition is produced and stored by exclusion of moisture.
The primer composition is suitable as primer for diverse substrates. It is particularly suitable for glass, glass ceramics, metals and alloys as well as for diverse plastics. The inventive primer composition is specially suited for glass and glass ceramics, particularly those used in automotive engineering.
It can be advantageous to pre-treat the substrates before the application. Such pre-treatment methods include physical and/or chemical pre-treatment, for example polishing, sandblasting, brushing etc, or treatment with detergents, solvents, coupling agents, solutions of coupling agents.
The primer is applied to a substrate by means of brush, felt, cloth or sponge. This application can be done manually or automatically, particularly by means of robots. Moreover, several layers of the primer composition can also be applied.
The primer composition is advantageously used as primer for adhesives, sealants, floorings, particularly for 1-component, moisture-curing polyurethane adhesives or sealants based on polyurethanes or polyurethane-silane-hybrides. Preferred application fields of these primers are areas where industrially prepared components are also bonded. It deals particularly with applications where the primer is applied in the supplier's factory.
The inventive primer composition is characterized by an excellent adhesion on glass and glass ceramics which, even after drastic stresses, such as for example by cataplasma test (7 days storage in 100% relative atmospheric humidity at 70° C.) remain intact. Moreover, the primer is characterized by a long open time of more than a month. The fact that the inventive primer can be used already after a short flash off times of typically 30 seconds is also extraordinary.
EXAMPLES
Reference Raw materials source Methyl-ethylketone (“MEK”) Scheller, Thommen 4-Toluensulfonylisocyanate (“TI”) Bayer Desmodur N100 (“N100”) (NCO-content 22%) Bayer 3-Aminopropyltrimethoxysilane (Silquest A-1110) Osi Crompton (“Aminosilane”) N-Butyl-3-aminopropyltrimethoxysilane (Dynasilan A- Degussa-Hiils 1189) (“sec.Aminosilane”) 3-Mercaptopropyltrimethoxysilane (Silquest A-189) Osi Crompton (“Mercaptosilane”) Vinyltrimethoxysilane (Silquest A-171) (“Vinylsilane”) Osi Crompton Trimethylolpropane BASF Dibutyltindilaurate Rohm & Haas
Primer Compositions
Exemplary Production of a Primer Composition: P-01
161.8 g Desmodur N100 is reacted with 54.2 g mercapto silane in a preliminary step in 54 g 1:1-solvent mixture of xylene and methoxypropylacetate in inert atmosphere during 4 hours at increased temperature. The mercapto silane is added in a slow manner.
In a subsequent step 64 g of amino silane is slowly dropped into the product of the first step in the presence of 5 g of drying agent as well as 649 g methylethyl ketone in inert atmosphere. After termination of this reaction 11.5 g trimethyl propane is slowly added by stirring at increased temperature till no NCO-content can be measured. At the end the additional constituents like catalyst and vinyl silane are also added.
TABLE 1
Primer Compositions
P-01
P-02
P-03
P-04
P-05
P-06
P-07
Ref.
A
N100
16.18
16.18
16.18
16.18
16.18
16.18
16.18
16.18
B
Mercaptosilane
5.42
5.42
5.42
5.42
5.42
5.42
5.42
5.42
B
Aminosilane
6.40
6.40
6.40
4.00
8.00
6.40
6.40
6.40
C
Trimethylolpropane
1.15
1.05
1.30
1.75
0.75
1.15
2.63
Xylene/Methoxypropylacetate
5.40
5.40
5.40
5.40
5.40
5.40
5.40
5.40
(1/1)(w/w)
Methylethylketon
64.92
65.02
64.77
66.72
63.72
64.42
62.94
65.57
Drying agent
0.50
0.50
0.50
0.50
0.50
0.50
0.50
0.50
DBTL
0.03
0.03
0.03
0.03
0.03
0.03
0.03
0.03
Vinylsilane
0.50
0.50
0.50
r
120%
109%
135%
112%
134%
120%
274%
0%
P-01
P-08
Ref.
Ref-1.
Ref.-2
Ref.-3
A
N100
16.18
16.18
16.18
16.18
16.18
16.18
B
Mercaptosilan
5.42
5.42
5.42
12.43
B
Aminosilane
6.40
11.35
6.40
sek.Aminosilane
8.40
14.90
C
Trimethylolpropane
1.15
1.15
1.15
1.15
1.15
Xylene/Methoxypropylacetate
5.40
5.40
5.40
5.40
5.40
5.40
(1/1)(w/w)
Methylethylketon
64.92
65.02
65.57
65.02
65.02
65.02
Drying agent
0.50
0.50
0.50
0.50
0.50
0.50
DBTL
0.03
0.03
0.03
0.03
0.03
0.03
Vinylsilane
0.50
0.50
0.50
0.50
r
120%
120%
0%
120%
120%
120%
The other examples P-02 to P-08 were prepared in similar manner with the amounts indicated in table 1.
The reference example Ref. shows no cross-linking agent C. The reference examples Ref-1, or Ref-2, correspond to the examples P-01, or P-08, whereby the primary aminosilane was substituted by the molar amount of a secondary aminosilane. The reference example Ref-3 corresponds to the examples P-01 whereby the primary aminosilane was substituted by the molar amount of the mercaptosilane, and thus contains no primary aminosilane.
Pretreatment of the Substrate and Application of the Primer
Substrate
Source
Float glass
Firm Rocholl, Schönbrunn, Germany
Glass with bismuth-based ceramic
Firm Rocholl, Schönbrunn, Germany
coating Cerdec 14259
The substrates were cleaned by a mixture of isopropanol/water (1/1 w/w). The primer was applied after a waiting time of 5 min. The non-tin-side of the glass was used for adhesion tests.
Application of the Adhesive and Test Methods
After a waiting time t specified in table 2 after the application of the primer a bead of adhesive was applied onto said primer. The following moisture curing polyurethane- or silane-modified polyurethane adhesives which are commercially obtainable from Sika Schweiz AG are used:
Sikaflex ®-250 HMA-1
(“HMA-1”)
Sikaflex ®-250 DM-1
(“DM-1”)
Sikaflex ®-250 DM-2
(“DM-2”)
Sikaflex ®-555
(“SF-555”)
The adhesive was tested after a curing period of 7 days in a climatised room (“KL”) (23° C., 50% rel. atmospheric humidity) as well as after subsequent cataplasma storage (CP) of 7 days at 70° C., 100% rel. atmospheric humidity.
The adhesion of the adhesive was tested by means of “bead test”. For this, incision is made at the end just over the adhesive surface bonding surface. The sectioned end of bead is held with round pliers and pulled from the substrate. This takes place by careful rolling of the bead on the tips of the pliers as well as by placing a cut section perpendicular to the direction of the bead till the blank substrate. The bead speed of peeling off of the bead is to be selected in such a manner that about every 3 seconds a cut section must be made. The test distance must correspond to at least 8 cm. The assessment is made based on the amount of adhesive remaining on the substrate after peeling off of the adhesive (cohesive failure). The assessment of the adhesion properties is done by evaluating the cohesive part on the adhesion surface:
1=>95% cohesive failure
2=75-95% cohesive failure
3=25-75% cohesive failure
4=<25% cohesive failure
It is indicated by adding “FH” that the adhesive shows a film adhesion on the primer leading to a fracture between the primer and adhesive. It is indicated by adding “P” that the primer peels off from the substrate and therefore the adhesion of the primer to the substrate represents a weak point. Test results with cohesive failures of less than 75% are considered as being unsatisfactory.
Results
Table 2 shows the results of the adhesion tests on glass of the examples P-01 to P-07 as well as the reference examples Ref. for short (1 minute, 10 minutes) and long (1 week, 2 weeks, 1 month) open times which represent the waiting times between the application of the primer and of the adhesive.
TABLE 2
Adhesion results of primers having variable open times.
Open time
1 min
10 min
1 w
2 w
1 m
Storage
Primer
Adhesive
KL
CP
KL
CP
KL
CP
KL
CP
KL
CP
P-01
HMA-1
1
1
1
1
1
1
1
1
4
1
P-01
DM-1
1
1
1
1
1
1
3FH
1
2
1
P-01
DM-2
1
1
1
1-2
1
1
1
1
1-2
1
P-01
SF-555
1
1
1
1-2
1
1
1
1
1
1
P-02
HMA-1
1
1
1
1
1
1
1
2
4
1
P-02
DM-1
1
1
1
1
1
1
1
2
2
1
P-02
DM-2
1
1
1
1
1
1
1
1
1-2
1
P-02
SF-555
1
1
1
2P
1
1
1
1
1
1
P-03
HMA-1
1
1
1
1
1
1
1
3
4
1
P-03
DM-1
1
1
1
1
1
1
1
1
2
1
P-03
DM-2
1
1
1
1
1
1
1
1
1-2
1
P-03
SF-555
1
1
1
1
1
1
1
1
1
1
P-04
HMA-1
1
1
1
1
1
1
2
2
4
1
P-04
DM-1
1
1
1
1
1
1
1
1
3
1
P-04
DM-2
1
2-3P
1
1
1
1
1
1
2-3
1
P-04
SF-555
1
1
1
1
1
1
1
1
1
1
P-05
HMA-1
1
2TB
1
1
1
1
1
4P
4
1
P-05
DM-1
1
1
1
1
1
1
1
4P
1-2
1
P-05
DM-2
4FH
4FH
1
4FH
1
1
1
4P
1-2
1
P-05
SF-555
2
3
1
1
1
1
1
1
1
1
P-06
HMA-1
1
2
1
4
2
1
2
1
4
1
P-06
DM-1
1
2
1
2
1
1
1
1
3
1
P-06
DM-2
1
2
1
4
1
2
1
1
1
1
P-06
SF-555
1
1
1
1
1
4
1
1
1
4
P-07
HMA-1
3
4
3
4
1
1
1
3-4
1
1
P-07
DM-1
3-4
3
3
4
1
1
1
2-3
1
1
P-07
DM-2
3
3
3
4
1
2
1
3-4
1
1
P-07
SF-555
1
1
1
1
1
1
1
3-4
1
3
Ref.
HMA-1
4
4
4
4
4
4
4
4
4
4
Ref.
DM-1
4
4
4
4
4
4
3
4
3
4
Ref.
DM-2
4
4
4
4
4
4
3
4
4
4
Ref.
SF-555
1
1
1
1
1
4
1
4
1
4
—
HMA-1
4
4
4
4
4
4
4
4
4
4
—
DM-1
4
4
4
4
4
4
4
4
4
4
—
DM-2
4
4
4
4
4
4
4
4
4
4
—
SF-555
1
2-3
1
2-3
1
2-3
1
2-3
1
2-3
TABLE 3
Adhesion on glass and glass ceramics
Substrate
Glass
Glass
Ceramics
Open time
10 min
10 min
Storage
Primer
Adhesive
KL
CP
KL
CP
P-01
HMA-1
1
1
1
1
P-01
DM-1
1
1
1
1
P-01
DM-2
1
1-2
1
1
P-01
SF-555
1
1-2
1
1
P-02
HMA-1
1
1
1
1
P-02
DM-1
1
1
1
1
P-02
DM-2
1
1
1
1
P-02
SF-555
1
2P
1
1
P-03
HMA-1
1
1
1
1
P-03
DM-1
1
1
1
1
P-03
DM-2
1
1
1
1
P-03
SF-555
1
1
1
1
P-04
HMA-1
1
1
1
1
P-04
DM-1
1
1
1
1
P-04
DM-2
1
1
1
1
P-04
SF-555
1
1
1
1
P-05
HMA-1
1
1
1
1
P-05
DM-1
1
1
1
1
P-05
DM-2
1
4FH
4FH
4FH
P-05
SF-555
1
1
1
1
P-08
DM-1
1
1
1
2
P-08
DM-2
1
2
1
2
P-08
SF-555
1
2
2
1
Ref-1
DM-1
4
4
3
4
Ref-1
DM-2
5
4
2
3
Ref-1
SF-555
2
2
3
3
Ref-2
DM-1
4
5
4
3
Ref-2
DM-2
4
5
1
2
Ref-2
SF-555
2
2
3
1
Ref-3
DM-1
3
4
3
3
Ref-3
DM-2
4
4
4
4
Ref-3
SF-555
1
2
2
1
—
HMA-1
4
4
4
4
—
DM-1
4
4
4
4
—
DM-2
4
4
4
4
—
SF-555
1
2-3
1
4
Table 2 shows that the inventive primer is characterized by an excellent adhesion to glass. Moreover, it can be seen that the example P-06 exhibits considerably poorer adhesions as compared to comparison to the other examples P-01 to P-05, particularly at short open times, but is still clearly better than the reference example Ref. as well as the example without the primer.
Table 3 shows the comparison between adhesion to glass and glass ceramics in which the inventive primer exhibits extremely good adhesion both to glass and also to glass ceramics. In case of the silane modified adhesive Sikaflex®-555, it is apparent that the adhesion is also retained not only in air-conditioned storage but also in cataplasma also in case of glass ceramics. In case of primer P-05 the adhesive exhibits a certain weakness in adhesion with the result that a film adhesion occurs, but this means that the primer shows a good adhesion on the substrate.
A primer P-01f filled with 10% carbon black was produced on the basis of primer P-01. Its adhesion results after different long storage are shown in table 4. The primer was stored for period indicated in the table at the stated temperature and subsequently applied to glass as described. After the stated open time the adhesive was subsequently applied and tested after 7 days of curing, respectively after the subsequent cataplasma storage of 7 days.
TABLE 4
Adhesions as function of storage duration and open time of P-01f
P-01f
Open time
3 min
10 min
2 m
3 m
4 m
Temperature
Duration
Adhesive
KL
CP
KL
CP
KL
CP
KL
CP
KL
CP
23° C.
1 m
HMA-1
1
1
1
1
1
1
1
1
4
3
DM-1
1
1
1
1
1
1
1
1
1
1
DM-2
1
3
1
2
1
1
1
1
1
1
23° C.
9 m
HMA-1
1
4
n.b.
n.b.
1
1
4
4
n.b.
n.b.
DM-1
1
1
n.b.
n.b.
1
1
4
4
n.b.
n.b.
DM-2
1
1
n.b.
n.b.
3
4
1
1
1
1
23° C.
12 m
HMA-1
n.b.
n.b.
3
1
1
1
1
3
n.b.
n.b.
DM-1
n.b.
n.b.
3
1
1
5
1
1
n.b.
n.b.
DM-2
n.b.
n.b.
1
1
1
1
1
1
n.b.
n.b.
50° C.
1 m
HMA-1
1
1
1
1
3
1
3
2
4
1
DM-1
1
1
1
1
3
1
1
1
3
1
DM-2
1
1
1
1-2
2
1
2
1
2
1
(n.b. = not determined)
It is seen from the results of table 4 that the primer exhibits long storage stability and has long open times.
The results of the accelerated ageing, i.e. 1 month at 50° C., show that especially the adhesion deteriorates at longer open times.
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The invention relates to a primer composition comprising a compound A1 which contains isocyanate-reactive groups. In order to produce said compound A1, a polyisocyanate A that is provided with at least three isocyanate groups, at least one silane B of formula (I), and a crosslinking agent C comprising at least three isocyanate-reactive functional groups are used. Also disclosed is the use of the inventive primer composition as a primer for adhesives, sealing compounds, or floor coverings, especially one-component moisture-hardening polyurethane adhesives or polyurethane sealing compounds based on polyurethanes or polyurethane-silane hybrids. The inventive primer composition is characterized particularly by excellent adhesion to glass and glass ceramics as well as an extended open time.
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The present application claims priority to PCT/DE02/01227 filed 04 Apr. 2002 and DE10116692.3 filed 04 Apr. 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
A tool that connects plates or plate pieces that are overlapping, or plates with connecting points (punching rivets, screw bolt attachments, or the like) through the process of riveting (clinching, or the like).
2. Description of Related Art
According to a known tool (DE 44 35 460, FIG. 3), the sheathing pieces of the matrix, radially outward flexible, are moved against the force of spring plates. At the same time, these spring plates serve the purpose of attaching the matrix pieces to the matrix body. To this end, the matrix pieces are bolted at one end to the matrix body, and at the other end, they are bent and slide into the grooves of the corresponding sheathing pieces. There is also a flexible belt between the spring plates and the matrix pieces for the purpose of giving additional support and guidance to the matrix pieces. One disadvantage is the fact that this spring arrangement is a disturbance factor. Since these heavy-duty tools are exposed to rough conditions, the springs can loosen, which in turn can result in defective connecting points. In addition, it can require expensive reworking measures or the replacement of work pieces, since the automatic manufacturing does not allow for an immediate assessment of the defects. The other disadvantage is the fact that the installation of the tool, the mounting of the spring plates, as well as the setting up of the sheathing pieces is difficult and complex and, consequently, expensive.
There is another known tool of the same kind (EP 0744231 B1) in which, through the work piece material that is displaced between punch and base plate, two sheathing pieces placed opposite to each other are pushed apart against the force of the corresponding spring. The springs have a connecting section which runs transverse to the driving direction and is located in a groove underneath the base plate of the matrix. During the working process, with the aid of the spring-loaded sheathing pieces, the plates that have to be connected are first partly punched and then compressed. In this way, during the process of compression, some of the partly punched plates can move transverse to the direction of the sheathing pieces. Apart from the fact that, as a result of the punching, the plates are not connected tightly, this connection is also less durable than the connection made with the above-mentioned clinching tool. However, the reset springs of the sheathing pieces are also exposed to less pressure so that such a simple multi-cranked leaf spring could be used. It is also very easy to remove the work piece from the tool. But this tool is not able to make a clinching connection without cutting through the plate, not even if adjustments are made. However, this is also not intended since the connections are made with a completely different procedure.
Another known tool (EP 0835701 A 2) provides only two expanding pieces as alternatable sheathing pieces, which are held in place with metal springs. The two springs are connected with casing rings. Even in this case, the springs are only exposed to the pressure of two sheathing pieces placed opposite to each other. Therefore, it is actually not possible to monitor the displaced plates and their movement.
Another known tool (PCT-WO 97/029 12, DE 32 10 208) has a spring ring around the sheathing pieces which opens during the clinching process and the movement of the sheathing pieces. Even in this case, there is the disadvantage that the ring presents a disturbing factor, especially in the form of wear debris and the like, which can result in early wear-out. In addition, during the working process with this tool, the plates are partly clinched.
There is yet another tool (GB 2069394) in which the sheathing pieces of the matrix are connected in one piece with the matrix on the side opposite to the punch. Like a cantilever, they take on the work of the spring. The disadvantage of this tool is especially its high production costs as well as its lack of flexibility.
SUMMARY OF THE INVENTION
The tool has the advantage that there is not going to be any clinching of the plates and, consequently, there will also not be any loose connecting points. Therefore, the inventive tool is well suited for use in clinching procedures in which there is a controlled movement or the displaced plates because of the symmetrical arrangement along the centerline and because of the use of more than two flexible sheathing pieces. With a simple bar or leaf spring, which is extremely easy to house within the tool, sufficient force is provided to reset the sheathing pieces. This tool makes very good connecting points, and it is extremely inexpensive to produce. It is also quite robust and easy to mount. In case of a crosswise or star-shaped structure, the corresponding connecting sections intersect, or they are at least able to intersect. If the structure is circular, the springs branch off radially. Therefore, it is not art encompassing casing ring, but a disk that is located in the dividing plane of the matrix.
One useful design of the invention is the fact that the crank has a minimum radius of 10 percent of the matrix diameter. As is generally known, the durableness and effectiveness of the leaf spring greatly depend on its formation at the bearing point, where in contrast to a minimum radius, it is more likely that a bending point will result in a break of the springs.
Another useful design of the invention is the fact that, as demonstrated (in EP 0744231 B 1), the springs and their connecting sections are made from flats. This leaf-spring-like material is very easy to produce. It is possible to punch spring and connecting section in one piece. Afterward, it is cranked and cured. It is also very easy to mount.
A further useful design of the invention is the fact that the matrix is divided transverse to the driving direction in order to make the dividing plane; that is, the front side facing away from the working opening serves as dividing plane of the base plate.
A further useful design of the invention is the fact that the matrix base is formed like a bearing box in which the sheathing pieces are mounted and running. At the front side, the side facing away from the punch, the connecting pieces of the springs are supported.
A further useful design of the invention is the fact that there are radial and/or frontal grooves in the matrix base plate for the purpose of placing the springs or connecting sections. In these grooves, the sheathing pieces, springs, and connecting sections are housed in a way that one more or less smooth, cylindrical matrix is formed, which cannot easily be damaged. It is also easy to exchange in the machine tool.
A further useful design of the invention is the fact that the sheathing pieces are non-detachably connected with the free ends of the springs. These sheathing pieces are, for instance, supported on the matrix base plate at the side facing away from the punch in order to produce a counter acting force through the clinching force caused by the punch. As a result of the cleavage, they slide on the base plate radially outward, in each case against the force of the spring.
A further useful design of the invention is the fact that the sheathing pieces are attached to the sections by means of soldering, welding, or the like.
A further useful design of the invention is the fact that the free ends of the springs are bent to the inside in the direction of the working opening. The surfaces of the bent sections of the springs pointing to the direction of the punch serve as support for the sheathing pieces mounted there. In this way, comparatively small surfaces can house relatively wide sheathing pieces, especially if these sheathing pieces restrict the working opening radially.
A further useful design of the invention is the fact that the dividing plane runs between the base plate and a socket into which the machine tool is placed. Consequently, as mentioned above, a completely self-contained tool is produced.
A further useful design of the invention is the fact that there is a device between socket and base plate for the purpose of connecting the pieces. This connection of base plate and socket well secures the arrangement of the springs.
A further useful design of the invention is the fact that the connecting device consists of connection pins, or the like. In addition to forming a connection, this also fixes the two pieces with regard to their rotating position.
A further useful design of the invention is the fact that the volume dimensions of punch and working opening are adapted to the displaced material. Several sections of partition walls are fixed around the circumference of the working opening. The sections in between these walls are designed as alternatable pieces. In this way, the sheathing pieces can form completely the radial wall of the working opening, or they can form parts of the opening, leaving other parts in place, depending on the intended structure of the connecting knot.
A further useful design of the invention is the fact that the radial way of the alternatable sheathing pieces is rigidly restricted through blocks of the matrix. This provides cold compression for the displaced material and, as a result, considerably increases the strength of the connecting point. In addition, such blocks protect the sheathing pieces from falling out and the springs from over-expanding.
A further useful design of the invention is the fact that the punch is made in the form of a rivet, nut, bolt, or the like, in order to remain positive-fit and/or friction-locked in the resulting cupping opening after the clinching process is finished. This material bond gives an additional stability to the connection so that the cupping opening is completely positive-fit and the connecting point can no longer unlock.
Further advantages and useful designs of the invention are explained in the following descriptions, figures, and claims.
BRIEF DESCRIPTION OF THE FIGURES
Two variations of the embodiment of the invented tool are illustrated and explained in further detail in the following figures:
FIG. 1 Longitudinal section of the connecting tool
FIG. 2 Top view according to line I—I in FIG. 1
FIG. 3 Lateral view of the spring arrangement
FIG. 4 Top view of the spring arrangement in FIG. 3
FIG. 5 A variation of the spring arrangement or matrix
DETAILED DESCRIPTION OF THE INVENTION
As depicted with the tool in FIG. 1 , which is designed to connect plates and the like, several sheathing pieces ( 2 ) are mounted in the base plate ( 1 ) of the matrix with their upper free end radially outward alternatable. Through these sheathing pieces ( 2 ) and the matrix base plate ( 1 ), a working opening is defined in which, by means of a punch ( 4 ), areas ( 5 ) of plates ( 14 and 15 ) that have to be connected are pressed. In this way, a clinching connection is made. In order to improve the engagement of the deep-drawn and, afterwards, radially compressed plate section ( 5 ), in this clinching process, the matrix sheathing pieces ( 2 ) yield radially outward, contrary to the force of the springs ( 6 ). These springs are one-piece connected through a connecting section ( 7 ) on the side of the matrix base plate facing away from the working opening ( 3 ). For the protection and guidance of the matrix sheathing pieces ( 2 ), the springs ( 6 ), and the connecting sections ( 7 ), grooves ( 8 ) are located in the matrix base plate. In this way, it is easy to mount the matrix flush into the appropriated opening of the machine tool, and the sheathing pieces or spring parts are not interfering.
The base plate ( 1 ) is connected to a socket ( 9 )—which is not shown in the figure—which covers the grooves ( 8 ) in which the connecting section ( 7 ) is located. In this way, the spring arrangement is secured in the matrix, bringing about a completely self-contained tool which, in its dimensions, matches the dimensions of the machine tool for which it is designed. Between the matrix base plate ( 1 ) and the socket ( 9 ) there is a dividing plane. According to the invention, after inserting the spring, the matrix base plate is pressed into a corresponding recess ( 17 ) of the socket ( 9 ).
In order to achieve an exact guidance between the matrix sheathing piece ( 2 ) and the free end of the springs ( 6 ) and, in connection with this guidance, provide the free end of the spring with the required mobility, a longitudinal groove ( 16 ) incorporating the spring ( 6 ) is located at the backside of the sheathing pieces ( 2 ) facing the spring ( 6 ).
In addition, for their alternatable movement, the sheathing pieces ( 2 ) are guided in fixed sections. To this end, these sections ( 18 ) are connected to the matrix base plate ( 1 ) or socket ( 9 ) in the direction of the punch ( 4 ). At the socket ( 9 ), there are blocks ( 19 ) which restrict the mobility of the sheathing pieces ( 2 ). As a result, during the production process and the corresponding displacement of the work piece, a cold forming of the now compressed material takes place when the sheathing pieces ( 2 ) push against the blocks ( 19 ) and the punch ( 4 ) continues its lifting movement.
FIGS. 3 and 4 show a simple spring arrangement, forming a cross which consists of a crosswise connecting section ( 7 ) and the springs ( 6 ) located there. The springs ( 6 ) have cranks ( 13 ) in driving direction of the punch across from the connecting section ( 7 ). This spring arrangement consisting of four springs activates four sheathing pieces. The number of sheathing pieces corresponds to the number of free springs, so that the connecting section can take the form of a cross, be star-shaped, or the like.
As shown in FIG. 5 , the springs ( 6 ′) are bent at the top towards the inside, producing sections ( 11 ), on the surface of which matrix sheathing pieces ( 2 ′) are mounted. These sheathing pieces have the same function as in FIG. 1 but are constructed completely different. They are constructed in a way that their sheathing pieces ( 2 ′) restrict the working opening ( 3 ) radially towards the inside. Apart from that, however, these sheathing pieces, including the bent sections ( 11 ) of the springs ( 6 ′), are supported at the surface of the Matrix base plate ( 1 ′) in order to absorb the clinching force of the punch. During the clinching procedure, the sheathing pieces ( 2 ′) move radially to the outside. The matrix base plate ( 1 ′) is only represented in a dotted line in order to be able to show, from a top view, the spring ( 6 ′) or sheathing piece ( 2 ′) on the backside. In this view, the front spring is not shown.
All characteristics represented in the description, the following claims, and figures are significant for the invention, separately as well as in any form of combination.
REFERENCE LIST
1 Matrix base
2 Matrix sheathing pieces
3 Working opening
4 Punch
5 Areas
6 Springs
7 Connecting sections
8 Grooves
9 Sockets
10 Dividing plane
11 Sections
12 Surfaces
13 Cranks
14 Plates
15 Plate
16 Longitudinal groove
17 Recess
18 Sections
19 Block
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A tool, for making clinching connections, which has a multi-part matrix with matrix sheathing pieces that move to the outside and with counteracting springs. These springs are one-piece connected with each other through a connecting section. There are at least three sheathing pieces which are arranged axially symmetric around the centerline of the matrix.
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FIELD OF THE INVENTION
The present invention relates to ceramic rollers for transportation of photographic films and paper and polymeric webs into and out of a perforating or slitting/packaging machines. More particularly, the present invention relates to the net shape manufacturing of ceramic rollers.
BACKGROUND OF THE INVENTION
Precision rectangular perforation on photographic film edges is required to advance or rewind films in cameras or projection of movie films on the screen. During perforation of the photographic film, the photographic film rides over the outer surface of a series of rollers. This necessitates a hard and wear resistant outer surface for the rollers. The rollers are typically chrome plated stainless steel. The outer surface finish is very critical in that rollers should not scratch the photographic films. Thin chrome plating generally provides an adequate hard wear resistant surface which does not produce scratches on the photographic film. Thick chrome plating, however, generates a rough surface and is not used for rollers transporting photographic film. In addition, the rollers in the perforator rotate on a hardened steel pin. Typical inside diameters of the rollers are 60 to 70 thousandths of an inch. The small inner diameters of rollers are too narrow to provide a uniform chrome plating and that in turn limits the service life of conveyance rollers.
Moreover, photographic film contains corrosive silver halide salts which attack stainless steel through microcracks and pores in the chrome plating. The corrosion products along with the wear debris tend to contaminate the films and also accumulate between the pin and the inner surface of the roller, thus, reducing clearance and jamming the transportation process. Wear of the pin and roller causes excessive runout and the perforating machines need to be stopped and overhauled frequently.
The present invention replaces the chrome plated stainless steel rollers with yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic which rotate on hardened steel pins. Superior wear and corrosion resistance of the Y-TZP ceramic make these rollers more productive than chrome plated steel rollers. In addition, the absence of corrosion products and the lessening of steel pin wear reduces debris and helps reduce film contamination and prolongs the service life of the perforating machine.
SUMMARY OF THE INVENTION
The present invention is a ceramic roller which has an outer surface and an inner surface. The ceramic roller consists essentially of zirconium oxide and yttria in a molar ratio of yttria to zirconium oxide of from about 3:97 to about 5:95. The ceramic consists essentially of a tetragonal crystal phase grain and the inner and outer surfaces have a dimensional tolerance of between ±0.0015 inches.
In an alternate embodiment of the present invention, the outer surface of the ceramic roller has been modified to comprise the cubic phase crystal grain.
In another alternate embodiment of the present invention, the outer surface of the ceramic roller has been modified to comprise the monoclinic phase crystal grain.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a film conveyance arrangement in a film perforator.
FIG. 2 is a side view of a conveyance roller.
FIG. 3 is a sectional view of a conveyance roller.
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following detailed description and appended claims in connection with the preceding drawings and description of some aspects of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Shown in FIG. 1 is the film conveyance arrangement in a film perforator. It includes a feed chute 12, wherein the film is propelled towards the perforator 20. The perforator includes a die top 22 and a stripper plate 23. After perforation, the film 15 is conveyed through a shuttle chute 30 which includes a shuttle gate 34. The stripper plate 23 strips the film or paper from the punch and the perforations are removed by gravity. As is shown in FIG. 1, a series of guide rollers 17 convey the film 15 through the feed chute, the perforator 20 and the shuttle chute 34. Presently, chrome plated stainless steel rollers are typically used as conveyance rollers. However, the chrome plated stainless steel rollers do not have good wear resistance. In addition, chrome plated stainless steel rollers are prone to corrosion. Loose debris from corrosion can contaminate the photographic films. Part of the reason for the corrosion is that it is not possible to chrome plate uniformly the narrow inner diameter hole of the roller. This results in a shortening of the service life of the conveyance roller. In addition, wear of the steel pin along with the inner diameter of the roller increases the runout of the rollers and, thus, affects transportation of the film. The present invention solves the above identified problems.
The present invention uses a novel ceramic material described in U.S. Pat. Nos. 5,336,282 and 5,290,332. A net-shape ceramic roller for photographic film perforating machines is produced as described below. The ceramic roller requires essentially no machining after manufacture. The dimensional tolerances of the rollers are critical in a perforating machine. The ceramic rollers of the present invention have a dimensional tolerance of ±0.0015 inches for the outer diameter and ±0.0015 inches for the inner diameter. The ceramic rollers of the present invention have a concentricity of ±0.0005 and a surface finish on the outer diameter of better than 4 microinch. Ceramic rollers of the present invention are manufactured more cost effectively than stainless steel rollers. The ceramic rollers of the present invention are manufactured from yttria alloyed tetragonal zirconia polycrystals (Y-TZP) which contain from 3 to 5 mole percent of yttria in high purity zirconium oxide. Other alloying compounds like ceria (CeO) or magnesia (MgO) can also be used to achieve similar properties. Materials like silicon carbide or composites like zirconia reinforced alumina, or silicon carbide reinforced alumina may also be used for this application.
Pure zirconia can exist in three different crystallographic states depending on the melting and sintering temperatures. The monoclinic phase is formed at the lowest temperature. As the temperature increases, the monoclinic phase first transforms to a metastable tetragonal and then to a cubic phase. The cubic and tetragonal phases can be stabilized at room temperature by alloying with yttria, calcia, ceria and magnesia.
The fabrication process of ceramic rollers of the present invention involves cold uniaxial pressing of 3 to 5 mole percent yttria-zirconia powders to a green shape and then sintering to yield net-shape rollers. By controlling several critical steps in the process, net-shape rollers were produced within ±0.001 percent of the targeted shape. The following are the essential steps of this process:
1. The powder is well controlled to ensure repeatability of the process. The particle size and their distribution must be uniform and consistent. The agglomerate size is 30 to 60 μm, the average being 50 μm. The grain size is from 0.1 to 0.6 μm, the average being 0.3 μm. The distribution of grain size is as follows;
10% less than 0.1 μm
50% less than 0.3 μm
90% less than 0.6 μm.
2. Purity of the material must be well controlled. The purity must be from 99.9 to 99.99 percent. The alloy content of the yttria is maintained between 3 and 5 mole percent, the preferred concentration is 3 mole percent. Polyvinyl alcohol is used as a binder, the concentration of which varies from 3 to 5 percent by volume. The preferred concentration of the binder is 4 percent. Surface area of the individual grain ranges from between 10 to 15 m 2 /g and the preferred value is 14 m 2 /g.
3. Mold design. The mold used to manufacture the rollers of the present invention must be within ±0.0005 inches for the outer diameter and ±0.00025 inches for the inner diameter. Shown in FIGS. 2 and 3 is a roller 40 produced using the present invention. The mold involved must be capable of producing very precise green parts so that the final dimensional tolerances after sintering can be achieved.
4. Sintering schedule. The following is the sintering schedule which is required for the present invention:
a. Heating the green part from room temperature to 300° C. at a rate of 0.3° C./min (presintering step).
b. Heating the green part from 300° C. to 400° C. at a rate of 0.1° C./min.
c. Heating the green part from 400° C. to 600° C. at a rate of 0.4° C./min.
d. Heating the green part from 600° C. to 1500° C. at a rate of 1.5° C./min and holding the part at 1500° C. for 120 minutes for sintering.
e. Cooling the sintered part from 1500° C. to 800° C. at a rate of 2° C./min.
f. Cooling the sintered part from 800° C. to room temperature at a rate of 1.6° C./min.
Deviation from the above sintering schedule or other factors noted above will not produce the dimensional tolerances as discussed below.
Example 1
Zirconia powders were alloyed with up to 5 mole percent yttria, preferably 3 mole percent, and calcined to get single phase tetragonal structure. The alloyed zirconia powders were cold compacted using high precision molds to form green rollers. The compacting pressures were varied between 10 and 20 kpsi, preferably 15 kpsi. The green rollers were sintered at temperatures ranging from 1400 to 1600 degrees C for times between 1 and 3 hours, preferably at 1500 degrees C for 2 hours. During sintering, rollers were placed on flat plates such as alumina which could withstand the high temperature.
X-ray diffraction pattern analysis shows 100% tetragonal structure of the rollers produced from the above process. The hardness measured by Knoop indenters was in the range of 1000 to 1300 KHN. Deviation in dimensional tolerances were as follows. The outer diameter had a tolerance of ±0.0015 inches, the inner diameter had a dimensional tolerance of ±0.00025 inches and the length dimensional tolerance was ±0.001 inches. The ceramic rollers produced in the above process were placed in a perforator and tested along with conventional chrome plated stainless steel rollers. Not only did the ceramic rollers last 5 to 15 times longer than the stainless steel rollers but the steel pins did not show any wear or corrosion and the wear debris was less in the vicinity of the ceramic rollers. As a whole, the perforating machine ran uninterrupted 5 to 15 times longer producing better quality and cleaner films.
Example 2
Cubic outer surfaces were produced by placing the rollers completely buried in MgO powder and sintered at 1500° C. as described in Example 1. The outer diameter and inner diameter surfaces which are the critical wear surfaces were modified to the cubic structures. These rollers have not been tested in the machines but previous results suggest a longer service life than Y-TZP rollers.
Example 3
Monoclinic outer surfaces were produced by placing the rollers completely buried in very fine (approximately 0.3 micrometer) pure zirconia powder and sintered at 1500° C. as described in Example 1. Coupled angle X-ray diffraction indicated that the core was tetragonal phase. Glancing angle X-ray diffraction demonstrated a monoclinic phase case on the surface in contact with the zirconia powder.
While there has been shown and described what are present considered the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes, alterations and modifications may be made therein without departing from the scope of the invention as defined by the appended claims.
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A ceramic conveyance roller having a tetragonal phase crystal grain structure includes zirconium oxide and yttria and the molar ratio of yttria to zirconium oxide of from about 3:97 to about 5:95. The outer surface of the ceramic roller has a dimensional tolerance of less than 0.003 inches and the inner surface has a dimensional tolerance of less than 0.0005 inches. The outer surface of the roller can be modified to the cubic phase crystal grain or the monoclinic phase crystal grain.
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This application is divisional application of U.S. patent application Ser. No. 09/221,637 filed Dec. 23, 1998, now U.S. Pat. No. 6,124,587, which is a continuation application of U.S. patent application Ser. No. 08/825,435 filed Mar. 28, 1997 and now U.S. Pat. No. 5,854,482, which is a continuation application of U.S. patent application Ser. No. 08/477,448 filed Jun. 7, 1995, now abandoned, which is a divisional application of U.S. patent application Ser. No. 08/424,125 filed on Apr. 19, 1995, and now U.S. Pat. No. 5,703,356, which is a continuation-in-part of U.S. patent application Ser. No. 08/199,982 filed on Feb. 18, 1994, now abandoned, which is a continuation of U.S. patent application Ser. No. 07/956,907 filed on Oct. 5, 1992, now U.S. Pat. No. 5,288,993.
FIELD OF THE INVENTION
The present invention relates to dual layer optical balls for use with pointing devices for cursors on displays for personal computers, workstations and other computing devices having cursor control devices, and more particularly relates to optical devices and methods for translating rotation of a patterned ball over optical elements or movement of an optical device over a patterned surface into digital signals representative of such movement.
BACKGROUND OF THE INVENTION
Pointing devices, such as mice and trackballs are well known peripherals for personal computers and workstations. Such pointing devices allow rapid relocation of the cursor on a display screen, and are useful in many text, database and graphical programs. Perhaps the most common form of pointing device is the electronic mouse; the second most common may well be the trackball.
With a mouse, the user controls the cursor by moving the mouse over a reference surface; the cursor moves a direction and distance proportional to the movement of the mouse. Although some electronic mice use reflectance of light over a reference pad, and others use a mechanical approach, most prior art mice use a ball which is on the underside of the mouse and rolls over the reference surface (such as a desktop) when the mouse is moved. In such a prior art device, the ball contacts a pair of shaft encoders and the rotation of the ball rotates the shaft encoders, which historically includes an encoding wheel having a plurality of slits therein. A light source, often an LED, is positioned on one side of the encoding wheel, while a photosensor, such as a phototransistor, is positioned substantially opposite the light source. Rotation of the encoding wheel therebetween causes a series of light pulses to be received by the photosensor, by which the rotational movement of the ball can be converted to a digital representation useable to move the cursor.
The optomechanical operation of a trackball is similar, although many structural differences exist. In a trackball, the device remains stationary while the user rotates the ball with the thumb, fingers or palm of the hand; one ergonomic trackball is shown in U.S. Pat. No. 5.122,654, assigned to the assignee of the present invention. As with the mouse. the ball in a conventional trackball typically engages a pair of shaft encoders having encoding wheels thereon. Associated with the encoding wheels are tight sources and photosensors, which generate pulses when the movement of the ball causes rotation of the shaft encoders. One prior art trackball using this approach is shown in U.S. Pat. No. 5,008,528.
Although such a prior art approach has worked well for some time, with high quality mice and trackballs providing years of trouble-free use, the mechanical elements of such pointing devices necessarily limit the useful life of the device.
Optical mice which illuminate a reference pad, while having few or no mechanical parts, have historically been limited due to the need for the reference pad to have a regular pattern, as well as many other limitations.
Additionally, in conventional electronic mice, a quadrature signal representative of the movement of the mouse is generated by the use of two pairs of LED's and photodetectors. However, the quality of the quadrature signal has often varied with the matching of the sensitivity of the photosensor to the light output of the LED. In many instances, this has required the expensive process of matching LED's and photodetectors prior to assembly. In addition, varying light outputs from the LED can create poor focus of light onto the sensor, and extreme sensitivity of photosensor output to the distance between the LED, the encoding wheel, and the photosensor.
There has therefore been a need for a photosensor which does not require matching to a particular LED or batch of LED's, while at the same time providing good response over varying LED-to-sensor distances.
In addition, many prior art mice involve the use of a mask in combination with an encoder wheel to properly distinguish rotation of the encoder wheel. Because such masks and encoder wheels are typically constructed of injection molded plastic, tolerances cannot be controlled to the precision of most semiconductor devices. This has led, effectively, to a mechanical upper limit imposed on the accuracy of the conventional optomechanical mouse, despite the fact that the forward path of software using such mice calls for the availability of ever-increasing resolution. There has therefore been a need for a cursor control device for which accuracy is not limited by the historical tolerances of injection molding.
SUMMARY OF THE INVENTION
The present invention substantially overcomes the foregoing limitations of the prior art by providing an optical sensing system which eliminates entirely the use of shaft encoders, the encoding wheels associated with shaft encoders, masks or other mechanical elements normally associated with optomechanical pointing devices. The present invention can be implemented with either a mouse or a trackball, although the exemplary embodiments described hereinafter will discuss primarily trackball implementations. In addition, while most embodiments require a patterned ball, some embodiments of the present invention do not require any ball at all.
For those embodiments which use a ball, the present invention employs a ball having a pattern of spots (which are typically but not necessarily irregular in location and may be randomly sized within a suitable range) in a color which contrasts with the background color, such as black spots on an otherwise white ball. One or more light sources, typically LED's, illuminate a portion of the ball and a portion of that light illuminates a sensor array comprising a plurality of individual sensor elements to create an image of a portion of the ball. An optical element such as a lens or diffractive optical element may be provided to focus the image of the ball on the array. The signals generated by the array are then acted upon by logic and analog circuits, for example employing a biologically inspired VLSI circuit, such that the movement of the ball is converted into X and Y components for movement of the cursor on the video display. Except for the mechanical aspects of the ball itself (and in some instances the bearings on which the ball is supported), the electronic trackball of the present invention is entirely optical: when the ball is included, the trackball of the present invention may reasonably be thought of as an optomechanical pointing device although it has no mechanical moving parts other than the ball. It will be apparent that the techniques used herein may readily be adapted to other types of pointing devices, particularly electronic mice.
It is an object of the present invention to utilize a dual-layer optical ball for use in a cursor control pointing device. The ball is illuminated by a light source that emits light signals at, at least, a first wavelength, the ball having an inner layer surface that is capable of diffusing a light signal and an outer layer having a substantially smooth surface that surrounds the inner layer. The outer layer is substantially transparent to light at the first frequency. The inner layer diffuses the light signals at different intensities depending upon an the area of the inner surface that is illuminated.
Another object of the present invention is to provide a pointing device in which light illuminating a surface is directed to a sensor through a mirror and lens combination.
It is yet another object of the present invention to provide an electronic pointing device employing a random pattern of randomly sized and shaped spots on a ball in combination with an optical array to provide signals for generating cursor control signals.
It is a still further object of the present invention to provide an electronic pointing device using a light source in combination with an optical element and a photosensitive array to provide signals for generating cursor control signals.
Yet another object of the present invention is to provide an optical pointing device which does not require a ball.
Still a further object of the present invention is to provide an electronic mouse not requiring any special pattern or tablet.
Yet a further object of the present invention is to provide a pointing device which employs frustrated total internal reflection to detect movement.
Another object of the present invention is to provide an optical pointing device which uses the human fingerprint as a pattern for detecting movement of the pointing device.
These and other objects of the present invention may be better appreciated from the following detailed description of the invention, taken in combination with the accompanying Figures.
THE FIGURES
FIG. 1 shows in exploded view an electronic trackball according to the present invention.
FIG. 2A shows a generalized cross-sectional side view of the ball cage and ball of the present invention.
FIG. 2B shows a more detailed cross-sectional side view of the ball cage and ball of the present invention, including light paths.
FIG. 3 shows in schematic block diagram form the circuitry of a single pixel according to the present invention.
FIG. 4 shows an array of four of the block diagrams of FIG. 3, thus snowing the interrelationship between the pixels.
FIG. 5A shows in schematic block diagram form the circuitry used for cursor control in the present invention.
FIG. 5B shows in schematic block diagram form the signal conditioning circuitry of FIG. 5 A.
FIGS. 6A-6B show in flow diagram form the operation of the firmware which controls the logic of FIGS. 3 and 4.
FIG. 7A shows in exploded perspective view a second embodiment of a trackball in accordance with the present invention.
FIG. 7B shows in three-quarter perspective view the assembled elements of FIG. 7 A.
FIG. 8A shows in side elevational view the assembly of FIGS. 7A-B.
FIG. 8B shows in cross-sectional side view the assembled components shown in FIGS. 7A-B.
FIGS. 9A-9D show in side elevational, bottom plan, top plan and cross-sectional side view the ball cage shown generally in FIGS. 7A-8B.
FIGS. 10A-10D show in side elevational, top plan, bottom plan and cross-sectional side view the upper opto housing shown generally in FIGS. 7A-8B.
FIGS. 11A-11D show in side elevational, top plan, bottom plan and cross-sectional side view the lower opto housing shown generally in FIGS. 7A-8B.
FIG. 12A shows in simplified cross-sectional side view the operation of the optics of the invention.
FIG. 12B shows in simplified cross-sectional side view an arrangement of a lateral sensor according to the present invention.
FIG. 12C shows in simplified cross-sectional side view the operation of the optics according to an embodiment of the present invention.
FIG. 13 shows in block diagram form the components of the lateral sensor of the present invention.
FIG. 14 shows in schematic block diagram form the interface logic included within the sensor of FIG. 13 .
FIG. 15 shows in state diagram form the operation of the state machine included within the interface logic of FIG. 14 .
FIG. 16 illustrates the arrangement of pixels within the pixel matrix of the sensor of FIG. 13 .
FIG. 17A illustrates in schematic form the logic associated with each type P pixel in FIG. 16 .
FIG. 17B depicts two images of the ball on the pixel matrix at times t and t−1.
FIG. 18 shows in schematic diagram form the operation of the bidirectional pad of FIG. 13 .
FIGS. 19A and 19B show timing diagrams for the embodiment of FIG. during various phases of operation.
FIG. 20A shows in exploded perspective view a third embodiment of the present invention.
FIG. 20B shows in top plan view the third embodiment of the present invention.
FIG. 20C shows in front elevational view the third embodiment of the invention.
FIG. 20D shows in back elevational view the third embodiment of the invention.
FIG. 20E shows the third embodiment in side elevational view.
FIG. 21A shows in three-quarter perspective view the ball cage of the third embodiment.
FIG. 21B shows in cross-sectional side view the ball cage and optical elements of the third embodiment.
FIG. 21C shows the ball cage in rear elevational view.
FIG. 21D shows a portion of the ball cage in relation to a ball.
FIG. 22 shows in cross-sectional side view a fourth embodiment of the invention not requiring a ball.
FIGS. 23A-B show in exploded perspective view the optical components of a fifth embodiment of the invention. FIG. 23A is a wire frame view, with no hidden lines, to show additional structural features, while FIG. 23B is a more conventional perspective view.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, an electronic pointing device, and in particular an electronic trackball 10 , is shown in exploded perspective view. The trackball 10 includes an upper housing 20 , a printed circuit board 30 close to which a ball cage 40 is juxtaposed, a lower housing 50 , a ball 60 , and a plurality of buttons 70 located on the upper housing 20 which actuate associated switches 80 . The switches 80 are normally located on the circuit board 30 . The ball cage 40 typically is mounted on the PCB 30 , although in some instances it can be mounted on a housing member.
The printed circuit board 30 includes circuitry for operating on the signals provided by a sensor and associated logic (see FIGS. 3 and 4 ). Thus, movement of the ball in the trackball is in turn converted into digital signals which control the cursor on the screen of an associated personal computer, terminal or workstation. In serial port pointing devices, the printed circuit board will typically include a microprocessor and related driver circuitry for sending and receiving standard serial communications, such as RS232 signals. Alternatively, the signals provided by the mouse will be compatible with PS/2 ports.
Referring next to FIG. 2A, a ball cage 40 (shown in cross-section) and a ball 60 according to the present invention are shown. As will be immediately appreciated by those skilled in the art, the combination of ball 60 and ball cage 40 are markedly different from the prior art and form a key aspect of the present invention. In particular, the ball 60 can be seen to have a plurality of randomly shaped markings thereon in a color which contrasts with the background, such that the overall effect is a randomly speckled ball. A typical ball may, for example, have black spots on an otherwise white ball, although many other color combinations would be acceptable. In some embodiments, the ball may be illuminated by infrared or other non-visible light, in which case the speckles may be implemented in a manner which is visible to the associated light source but opaque to visible light. One example of such an arrangement is a coating on the ball which is opaque, for example black, in the visible spectrum, but transparent to infrared light, with appropriate speckles beneath the coating.
The randomly shaped markings or spots are randomly or irregularly arranged on the ball, although the markings are within a predetermined suitable range. Thus, the markings for this embodiment typically will range in size from 0.5 mm 2 to 0.7 mm 2 , with a density of about one spot per square millimeter. In an exemplary embodiment, the ball may be on the order of 10 mm in diameter, although the diameter could range from 5 mm or smaller to larger than 50 mm. In addition, and as can be better appreciated from FIG. 2B which shows a more detailed cross-sectional view of the ball and ball cage taken along the centerlines thereof, the ball cage 40 includes at least one (FIG. 2 A), and in some cases two or more (FIG. 2 B), light sources 200 such as an LED, which produces light that impinges on the ball 60 . The LED or other light source may include an integrally formed lens. The light from the light sources 200 is preferably reflected off the inside surface 205 of the outer wall 210 of the ball cage 40 , and is partially blocked by an interior wall 215 from striking directly the ball 60 . The inside surface 205 may be, for example, the inside surface of a sphere. In this manner the light from the light sources 200 is distributed relatively uniformly across a predetermined portion of the ball, while at the same time the light is caused to strike the ball obliquely, providing illumination of the ball and allowing light to light diffusely a sensor.
The ball is maintained in a rotatable position by a plurality of supports 150 , which may for example be rollers of a conventional type, or may be jeweled bearing surfaces of the type disclosed in U.S. patent application Ser. No. 07/820,500, entitled Bearing Support for a Trackball, filed Jan. 14, 1992 and assigned to the same assignee as the present invention, incorporated herein by reference. Although only one such roller is shown in FIG. 2B because of the view shown, a plurality, typically three, such rollers are provided to ensure uniform support for the ball 60 . A removable cover may be provided in some embodiments to permit readily insertion and removal of the ball 60 ; while such a removable cover is at present believed preferable, to permit cleaning of the ball and the inside of the pointing device, in at least some embodiments such a removable cover is unnecessary.
A photodetector array 220 is located centrally between the light sources 200 in a chamber 222 formed within a housing 224 . A portion of the light which strikes the ball 60 is diffusely reflected into the array 220 through an optical element 225 . The result is that an image of at least a portion of the illuminated surface of the ball is formed on the array 220 . In an important distinction from prior art optomechanical mice, the ball cage includes no shaft encoders, nor does it include the matched light source and photodetector typical of prior optomechanical mice. The optical element 225 is typically fixed in location between the housing 224 and an aperture housing 228 of which the interior wall 215 forms the outside surface. An aperture 229 is provided in the aperture housing 228 to permit the diffuse light reflected off the ball 60 to reach the optical element 225 , and then the photosensitive array 220 .
The photodetector array 220 will typically range in overall size from 1×1 mm to 7×7 mm, with each detector segment, or pixel, 220 A- 220 n having dimensions in the range of 20×20 μm to 300×300 μm or more, where the exact dimensions are determined by the size of the overall array and the size of the individual detector. In the exemplary embodiments discussed herein, each pixel is on the order of 300×300 μm. As will be discussed hereinafter in connection with FIGS. 3 and 4, in the preferred embodiments of the invention described herein, each pixel includes a photodetector element and associated circuitry for conditioning the output of the photodetector element into a signal useable external to the array. The diameter of the ball (or other pattern) area whose image is projected on the sensor and used for detection corresponds to the detector field diameter, and thus determines the maximum field angle to be covered by the optics. In an exemplary embodiment, a typical ball area diameter viewable for detection may be on the order of 2.8 mm, which represents a field of 6.2 mm 2 , and the array 220 may comprise a matrix of 8×8 detectors 220 A- n , although other embodiments described hereinafter may use a matrix of 11×11 detectors. Although a square array of detectors has been implemented (substantially as shown in FIG. 5 A), in at least some embodiments it may be preferable to arrange the individual detectors in a circle or hexagon. Depending upon the application, the detectors may be arranged across the area of the element, or may be positioned around the circumference, such as the circumference of a circle, where the contrast and resolution are more constant and thus give the best performance at the lowest cost, in one preferred embodiment, a square matrix is used but the corner elements are unused, to approximate a circle. In general, the objective is to match the area of the sensor with active pixels to the field of view obtained through the optics. In the exemplary embodiments discussed herein, this detector field typically approximates a circle, and in a typical embodiment will have a detector field diameter on the order of 3.25 mm.
At present, it appears that the size of an acceptable spot on the ball is relatively independent of the diameter of the ball. However, it has been found that the minimum size of a spot on the ball should be large enough that, when the image of the ball is focused on the sensor, the image of one spot covers at least one photodetector at all times and in all directions. It is preferred that, as a minimum, the size of the image of a single dot or speckle on the sensor should cover the center to center distance between two adjacent pixels on the sensor. In general, however, the preferred typical dot size has been selected so that the surface covered by the image of the dot covers about five pixels. As a maximum dot size, the image may cover substantially all of the sensor, although such an image size will cause degraded performance, as discussed below. Dot density may vary between 0.8 percent and 99.2 percent, but it is generally preferred that dot density be between twenty and seventy percent, with a typically preferred density on the order of forty percent. In a substantially ideal case, with a projected image size covering 8.3 mm 2 on the sensor, the total or sum of the black or low intensity areas comprises 3.2 mm 2 , while the total or sum of the white or higher intensity areas comprises 5.1 mm 2 . A contrast ratio of at least 2.5 between low intensity and high intensity areas of the image on the sensor is generally preferred.
Use of a dot size within the appropriate range permits motion detection of an image, (for example grayscale, binary or other format) to be based on tracking of the differences in spatial intensity (or, more simply, “edges”) of the spots. The maximum dimension of the spot is related to the minimum desired output precision of the system; as will be better appreciated hereinafter, the resolution of the system depends upon the number of edges that move divided by the total number of edges viewable. In an exemplary embodiment described hereinafter, for an output resolution greater than 15 dots/mm, it is useful to have an image with at least sixteen edges in each of the X and Y directions. If the number of edges is too small, movement of the cursor will appear “jumpy” in response to movement of the ball. For a four bit A/D converter plus sign, sixteen edges are used to reach unit increments.
In addition, it is important to maximize the amount of diffuse light energy reflected off the ball 60 and reaching the detector array 220 , and in particular each particular detector element 220 A- n . Although a wide range of magnifications is workable, a magnification of −1 is preferable to minimize the effects of mechanical tolerances. In addition, because of the small size, expense, and required modulation transfer, conventional lenses are unsatisfactory in at least some of the presently preferred embodiments. Instead, for those embodiments where conventional lenses are unsatisfactory, diffractive optical elements (DOE's) are preferable. However, in some embodiments, as described hereinafter, classical lenses may be used although some reduction in resolution may be necessary. Even for embodiments which use classical lenses, a resolution on the order of one line per millimeter is possible.
In particular, in at least some embodiments DOE's can provide the required light transfer while at the same time being fabricated by means of relatively conventional lithographic and etching methods known from microelectronics fabrication which fit into the normal manufacturing processes for fabricating the detector array itself, thus keeping additional costs to a minimum.
Additionally, while both spherical and a spherical lenses may be used in appropriate embodiments, a spherical functionality can be readily provided in a DOE at virtually no additional expense, and provides desirable light transfer capabilities although it does involve a more complicated design effort. In addition, different optical functions may be included in the same DOE, so that a portion of the DOE substrate can be fabricated with a first microstructure which directs the illumination cone from a light source at the appropriate incidence angle onto the ball surface, and a second microstructure which acts as an aspheric lens for pattern imaging, so that the image of the ball illuminated by the first microstructure is properly focused on the array 220 by the second microstructure. Although such multiple DOE structures are attractive for at least some embodiments of the present invention, in the generally preferred arrangement a DOE is used only for imaging the illuminated area of the speckled ball 60 onto the array 220 .
In such an exemplary embodiment, the focal length of the DOE is on the order of 2.4 mm where the total ball-to-detector array distance is on the order of 10 mm. The aperture diameter is on the order of 1-1.5 mm, or a numerical aperture (NA) on the order of 0.1. In addition, because the magnification is −1, the DOE is located midway between the ball 60 and the detector array 220 .
As with other optomechanical mice, the motion to be detected corresponds either to two translations (x,y), or one translation and one rotation about the center of the image. Additionally, for power consumption reasons, the LED's are pulsed in the manner described in U.S. patent application Ser. No. 07/717,187, filed Jun. 18, 1991, and entitled Low Power Optoelectronic Device and Method, meaning that the photodetectors 220 A-N can only detect a series of “snapshots” of the ball. Finally, the output of the detector array 220 preferably is compatible with a microprocessor input so that the signal can be readily converted to control of a cursor. For example, the output could conform to the type of output provided by designs employing optical encoders, such as described in U.S. Pat. No. 5,008,528, and would result in a two-bit quadrature code of about 15 impulsions per millimeter of ball displacement.
For the exemplary embodiment of FIGS. 1-2, circuitry for operating on the output signals received from the detector array 220 can be better understood by reference to FIG. 3, although FIG. 3 shows photodetector and logic comprising only a single pixel. Similar logic exists for each pixel 200 A- n in the detector array (a four pixel array is shown in FIG. 4 A), with the end result being a collective computation for the array as a whole. In an exemplary embodiment, the detector array 220 and the associated logic arrays of the type shown in FIG. 3 are all implemented on a single die, and in particular the individual detector and associated circuit elements formed on the same pixel.
As a general explanation of the operation of the circuits of FIGS. 3 and 4, the basic function of the algorithm is the correlation of edges and temporal intensity changes (“tics”). Referring particularly to FIG. 3, a photodetector 220 A such as a reverse biased photodiode generates a current proportional to the intensity of the light reflected off the ball onto the detector 220 A. The current is compared with a threshold by a threshold circuit 300 , to decide whether the pixel is white or black. The threshold can be adjusted differently for different sensor zones, such as to compensate for uneven lighting; such adjustment can be made automatically or otherwise, depending on application. Alternatively, a differential circuit, based on the signals from neighboring cells, can be used to reduce sensitivity to variations in lighting intensity, ball speckle density, and so on.
While a photodiode has been used in the exemplary embodiment of the photodetector 220 A, it is also possible to use a phototransistor in a number of embodiments. Phototransistors offer the advantage of high current gain, and thus give a high current output for a given level of illumination. However, in some embodiments photoaiodes continue to be preferred because at least some phototransistors have degraded current gain and device matching characteristics at low illumination, while onotodiodes at present offer slightly more predictable performance, and thus greater precision.
The output of the threshold circuit 300 is then supplied to a first memory 305 , which stores the state of the threshold circuit and allows the LED to be switched off without losing the illumination value of the Image. The first memory 305 , which may be either a flip-flop or a latch, thus may be thought of as a one-bit sample and hold circuit. More particularly, on the appropriate phase of the clock signal for example when the clock signal is high, the output of the threshold circuit 300 is copied into the memory, and that value is frozen into memory when the clock signal goes low. A second memory 310 , also typically a flip-flop or latch, stores the old state of the memory 305 in a similar manner, and thus the Output of the second memory 310 is equal to the output of the first memory 305 at the end of the previous clock cycle. The clock cycle is, in an exemplary embodiment, synchronized with the LED pulse, with the active edge being at the end of the light pulse. The old state of the memory is supplied to the pixels below and on the left through a “CURRENT STATE” bus 306 .
The temporal intensity change (“tic”) of a pixel can thus be determined by comparing the states of the first and second memories 305 and 310 , respectively. This comparison is performed by comparator logic 315 . In addition, the output of the first memory 305 is provided to two additional comparators 320 and 325 to detect edges on the top and at the right, respectively. The comparator 320 also receives information on a line 321 about the current state of the pixel above in the array. The comparator 325 receives information from the pixel on the right through a line 326 , or “EDGE ON RIGHT” bus, and supplies information to the pixel on the right through a line 327 . The comparators 315 , 320 and 325 may each be implemented as Exclusive-Or circuits for simplicity.
Edges at the left and bottom are communicated to this pixel by the pixels at the left and on the bottom, respectively, as can be better appreciated from the portion of the array shown in FIG. 4 A. More specifically, as with reference to FIG. 3, the corresponding pixel circuits will inject a current on an associated wire if a tic and a corresponding edge is detected with the result being that edges at the left and bottom are deducted from the values of the corresponding neighboring pixels. Similarly, the detection of a horizontal or vertical edge is signaled by injecting a current on the corresponding wire. Thus, left correlator logic circuit 330 receives information on a line 335 from what may be thought of as a “MOVE LEFT” bus, and also receives information from the adjacent pixel on a line 336 , which may be thought of as an “EDGE ON LEFT” bus. Down correlator logic 340 receives information on a line 345 from a “MOVE DOWN” bus, and also from a line 341 , supplied from the pixel below as an “EDGE ON BOTTOM” bus. In contrast, up correlator logic 350 receives one input from the circuit 330 and a second input on a line 351 , or “EDGE ON TOP” bus, and provides a signal on a line 355 , or a “MOVE UP” bus; right correlator logic 360 provides a signal on a “MOVE RIGHT” bus 365 . The correlator circuits may be thought of simply as AND gates.
In addition, a pair of switched current sources. 370 and 375 , provide a calibrated current injection onto respective busses 380 and 385 , when edges are detected: the current source 370 receives its sole input from the EDGE ON TOP bus 351 . Thus, when a horizontal edge is detected moving vertically, the current source 370 provides a calibrated current injection on line 380 ; similarly, when a vertical edge is detected moving horizontally, the current source 375 provides a calibrated current injection on line 385 . The lines 321 , 326 , 336 and 341 are all tied to false logic levels at the edges of the array. Calibration is not required in all embodiments.
Referring again to FIG. 4A, the implementation of a four pixel array can be better appreciated, and in particular the manner in which the correlator circuits 330 , 340 , 350 and 360 tie into adjacent pixel logic can be better understood. Similarly, the manner in which the vertical and horizontal edge detectors 370 and 375 cooperate with adjacent pixels can be better appreciated. In this first exemplary embodiment, an 8 x 8 matrix of pixels and associated logic has been found suitable, although many other array sizes will be acceptable in particular applications, and an 11×11 matrix is typically used in connection with the embodiments discussed hereinafter. In addition, the 8×8 array is, in an exemplary embodiment, comprised of four 4×4 quadrants, although it is not necessary to decompose the array into quadrants in other embodiments. Arrangement of the array into quadrants is helpful to detect rotation of the ball, although translation may be readily detected without such decomposition. Each quadrant is provided with its own outputs for the four directions of displacement, to permit calculation of displacement to be performed. In other embodiments, It will be appreciated that, basically, six bus lines are provided, with the output of each pixel tied to each bus. Depending on the characteristics of the image in the pixel and its neighbors, one to all six busses may be driven. In essence, the function of the circuits of FIGS. 3 and 4 is that each pixel 200 A- n can either drive a preset amount of current onto the associated bus (“ON”), or do nothing. By the use of very precise current drivers, it is then possible to sum the respective currents on each of the busses and determine the number of pixels that are on the bus. The six busses give six numbers, and the six numbers are combined to compute X and Y, or horizontal and vertical, displacements. In a presently preferred embodiment, X and Y displacements can be calculated as:
ΔX=(ΣMoveRight−ΣMoveLeft)/(ΣEdge x )
while
ΔY=(ΣMoveUp−ΣMoveDown)/(ΣEdge y ).
The algorithm may be summarized as follows:
Edge x =
Light (sample cell) > c × Light (cell left) or
(Boolean)
c × Light (sample cell) < Light (cell left)
Edge y =
Light (sample cell) > c × Light (cell top) or
(Boolean)
c × Light (sample cell) < Light (cell top)
Color =
Light (sample cell) > c × Light (cell left) or
(Boolean)
Light (sample cell) > c × Light (cell top)
MoveRight =
Edge x(t) (sample cell) and
(Boolean)
Edge x(t-1) (cell left) and
Color t-1 (cell left) = Color t (sample cell)
MoveLeft =
Edge x(t) (sample cell) and
(Boolean)
Edge x(t-1) (cell right) and
Color t-1 (cell right) = Color t (sample cell)
MoveUp =
Edge x(t) (sample cell) and
(Boolean)
Edge x(t-1) (cell bottom) and
Color t-1 (cell bottom) = Color t (sample cell)
MoveDown =
Edge x(t) (sample cell) and
(Boolean)
Edge x(t-1) (cell top) and
Color t-1 (cell top) = Color t (sample cell)
The value of c In the foregoing is a constant chosen to avoid noise and mismatch problems between two adjacent pixels, and in the embodiment described has been chosen to be a value of 2. Also, as previously discussed generally, it will be apparent from the foregoing algorithm that an increase in the number of edges present in the image results in an increase in the precision of the displacement measurement. It will also be apparent that the measured displacement is a fraction of the distance between two pixels. Some calculations may be done digitally or by other techniques.
The effect of a move on the pixels can be graphically appreciated from FIG. 17B, in which a pixel array includes an image comprising some dark pixels D, some light pixels L, and some pixels E which are undergoing an intensity change indicative of the presence of an edge. Thus, if a first oval area F is defined as the image of the ball at a time (t−1), and a second oval area S is defined as the image of the ball at a time (t), the direction of motion can be determined as shown by the arrow.
The difference between the right and left moves (the dividend in the above fractions) is easily implemented with a differential current amplifier having, in at least some embodiments, inverting and non-inverting inputs, as will be better appreciated in connection with FIG. 5B, discussed below.
Referring next to FIG. 5A, a generalized schematic block diagram is shown in which the array 220 is connected to the remaining circuitry necessary for operation as a trackball. The array 220 is connected through signal conditioning logic 505 A-B to A/D converters 510 and 520 to a microprocessor 530 . The A/D converter 510 supplies lines X0, X1 and X2, as well as the sign of the X movement, to the microprocessor on lines 540 ; likewise. A/D converter 520 supplies lines Y0, Y1 and Y2, as well as the sign of the Y movement, to the microprocessor on lines 550 . In some embodiments a four-bit A/D converter plus sign may be preferred, in which case an extension of the present circuit to four bits is believed within the normal skill in the art. Switches 80 supply additional control inputs to the microprocessor 530 . The microprocessor provides a clock signal on line 535 to the array and associated circuits, indicated generally at 545 , which may for example be implemented on a single sensor integrated circuit. The microprocessor 530 then communicates bidirectionally with line interface logic 560 , and the output of the line interface logic 560 provides cursor control signals in conventional form to a host system, not shown, over an output bus 570 . It will be appreciated by those skilled in the art that, in the embodiment detailed herein, the microprocessor 530 is used primarily for establishing the protocol for communications with the host, although it does also control LED pulsing, sleep mode and services interrupts.
With reference next to FIG. 5B, the signal conditioning circuits 505 A-B shown in FIG. 5 can be better understood. For convenience, only the X (horizontal move) signal conditioning circuit is shown in detail; the corresponding Y (vertical move) circuit is functionally identical. As previously noted, the cumulative current signals from the various pixels are summed on their respective busses. These sums of such currents from the “move left” and “move right” busses are subtracted in summing circuit 570 , followed by determination of the absolute value in an absolute value circuit 572 , after which the absolute value is provided to the A/D converter 510 . In addition, sign of the move is determined by providing the output of the summing circuit 570 to a comparator 574 . Finally, the sum of the edge currents is compared through a series of comparators 576 , the outputs of which are fed to combinational logic 578 , and thence provided as X0-X2 outputs. It should also be noted that the A/D conversion of circuits 510 and 520 can be readily implemented using a flash A/D converter. Division can be similarly implemented with a flash A/D converter by using a reference voltage proportional to the bus current for the horizontal (or vertical) edges. Use of current sources for such circuitry provides desirable simplicity and compactness.
Referring next to FIGS. 6A and 6B, the operating program which controls the microprocessor 530 can be better appreciated. Referring first to FIG. 6A, the operation of the system of FIGS. 1-5 begins at step 600 by resetting and initializing the logic, and enabling interrupts. A check is made at step 610 to determine whether the sleep mode has been enabled.
If sleep mode is enabled, reflecting no recent movement of the bail of the trackball, the logic of FIGS. 3-5 sleeps at step 620 until the timeout or the occurrence of bus activity, whichever occurs first. The occurrence of sleep modes is discussed in U.S. patent application Ser. No. 07/672,090, filed Mar. 19, 1991 and assigned to the same assignee as the present invention, the relevant portions of which are incorporated herein by reference. If sleep mode is not enabled, or if a timeout or bus activity has occurred, the switches 80 on the trackball are read at step 630 . After the switches are read, a check is made at step 640 to see whether the ball is moving. If not, sleep mode is enabled at step 650 .
If the ball is moving, the total displacement is computed at step 660 . Following computation of the displacement, the data is provided as an output to the host system at step 670 , and the process loops back to step 610 .
Referring next to FIG. 6B, the interrupt service routine of the present invention can be better understood. The interrupt service routine is accessed at step 675 whenever a timer function from the microprocessor generates an interrupt, although other methods of generating an interrupt at regular intervals are also acceptable in at least some embodiments. The system responds by acknowledging the interrupt at step 680 , followed at step 685 by pulsing the LEDs and sampling the sensor outputs for X and Y. At step 690 the time before a next sample is to be taken is calculated. The amount of time can vary, depending upon whether the displacement of the ball since the last sample is large or small; for example, a sampling rate of once per millisecond is typical during normal movement, with less frequent sampling when the ball is stopped. If the displacement is small, the time between successive samples is increased; if the displacement is large, the time between samples is decreased. In a presently preferred implementation, a “small” displacement represents a movement on the order of {fraction (1/400)} th of an inch or less; a “large” displacement will range between {fraction (5/800)} th and {fraction (7/800)} th of an inch. After computing the time until the next sample, the system returns from the interrupt at step 695 .
Referring next to FIGS. 7A-78 and 8 A- 8 B, an alternative embodiment of the present invention within a trackball is shown in exploded perspective view and indicated generally at 10 . FIG. 7B is an assembled view of the exploded perspective view of FIG. 7A, while FIG. 8A is a side elevational view of the assembled device. FIG. 8B is a cross-sectional side view taken along line AA—AA in FIG. 8 A.
It will be appreciated by those skilled in the art that the present embodiment comprises essentially four main elements: a ball with a detectable pattern on its surface; one or more light sources such as LEDs to illuminate the ball; a sensor for detecting an image of at least the portion of the ball illuminated by the light sources; and optics to allow the image to be focused on the sensor. In addition, a mechanical framework for supporting the ball, the light sources, the optics and the sensor must be provided. Each of these components will be described in turn, beginning with the mechanical framework.
An upper housing 700 and lower housing 705 are shown in breakaway view, and in at least some embodiments (such as portable or handheld computers or similar devices) will be incorporated into, for example, a keyboard. A ball 710 , of the Type described hereinabove, is maintained within a ballcage 715 by means of a retaining ring 720 which locks into the upper housing 700 . The ball is typically on the order of five to fifty millimeters in diameter, although larger or smaller sizes are acceptable in various applications; in the exemplary embodiment described herein, a ball diameter on the order of 19 millimeters is typical. Situated below the ballcage 715 is an opto housing cover 725 , into which is fitted an LED 730 through an angled bore better appreciated from FIGS. 10A-10D. In the exemplary embodiment described here, the LED may be, for example, in the 940 nm range. The opto housing cover 725 also provides a mount for a sensor 735 and a window 740 , as well as a lens 745 . The opto housing cover 7 then mates to a opto housing 750 and is fastened in position by means of an opto clip 755 . A second LED 730 is inserted into the opto housing 750 through a second angled bore, better appreciated from FIGS. 11A-11B. The opto clip 755 is retained in position by being fitted under a detent 760 formed on the opto housing 750 (best seen in FIG. 8 B). The subassembly 765 formed by the opto housing cover 725 and opto housing 750 and related components is positioned beneath the ball cage 715 .
Sandwiched between the ball cage 715 and subassembly 765 is a PC board 775 , with the ball 710 viewable by the subassembly 765 through an orifice 770 in a PC board 775 . The ball cage 715 is affixed to the PC board 775 by screws 780 or other suitable means, and the subassembly 765 is fastened to the PC board 775 and the ball cage 715 by means of screws 780 which extend through the opto housing 750 and PC board 775 into the ball cage 715 . The PC board 775 also includes one or more buttons or switches 785 . A connector 790 connects the PC board 775 to a host system (not shown), such as a notebook or other computer, in a conventional manner such as through a serial or PS/2 protocol.
Referring next to FIG. 9A-9D, the ball cage 715 is shown in greater detail. In particular, FIG. 9A shows the ball cage 715 in side elevational view, while FIG. 9B shows it in bottom plan view. FIG. 9C shows the ball cage in top plan view, while FIG. 9D shows the ball cage in cross-sectional side view taken along line B—B in FIG. 9 C. The ball cage 715 includes an upper annulus 860 with rotary slots 865 for locking in the retaining ring 720 . Below the upper annulus 860 the interior of the bail cage forms a bowl 870 . Excavated from the bowl are three slots 875 in which bearings 880 are placed for supporting the ball 710 . The bearings 880 are of the type described in U.S. patent application Ser. No. 07/820,500, entitled Bearing Support for a Trackball, filed Jan. 14, 1992, mentioned previously. The slots are positioned substantially with radial symmetry within the bowl 870 . In the bottom of the bowl 870 is an orifice 885 through which the ball may be viewed by the optical portion, discussed generally above and also discussed in greater detail hereinafter. Mounting pads 990 each include a bore 995 for receiving the screws 780 (FIG. 7 A), for mounting the ball cage to the PCB 775 (FIG. 7 A), while mounting pins or bosses 1000 also include a bore 995 to permit the subassembly 765 to be affixed to the ball cage 715 . A pair of guide pins 1005 are also provided for positioning the ball cage relative to the PCB 775 .
A flattened portion 1010 (FIG. 9D) is provided to receive and position the sensor relative to the lens and window discussed above in connection with FIG. 7 A. The flattened portion 1010 cooperates with the orifice 885 to permit the ball 710 (FIG. 7A) to extend through the orifice so as to be illuminated by light from the LEDs 730 and illuminate a sensor with light diffusely reflected off the ball 710 (FIG. 7 A).
Referring next to FIGS. 10A-10D and FIGS. 11A-11D, the opto housing cover and opto housings can be better appreciated. In particular, the opto housing cover 725 is shown in front elevational view (FIG. 10 A), rear elevational view (FIG. 10 B), side elevational view (FIG. 10 C), and front and rear perspective view (FIG. 10 D). The opto housing 750 , which mates to the upper housing 725 , is show in top plan view in FIG. 11A, in side elevational view in FIG. 11 B. and in bottom plan view in FIG. 11 C. In FIG. 11D, the combination of the opto housing cover, opto housing, lens, mirror and sensor are shown assembled in cross-sectional side view in relation to the ball.
With particular reference to FIGS. 10A-10D, the opto housing cover 725 functions to position the LEDs 730 in a manner which floods a selected portion of the ball 710 , while also positioning the lens, window and sensor relative to the ball so that light reflected from the ball impacts the lens and, from there, the sensor. The housing 725 includes an angled bore 1020 , at the outside end of which one of the LEDs may be positioned. The bore communicates with the central portion of the upper housing. A raised member 1025 positioned substantially at the center of the upper housing provides support for one end of the window 740 , while the lens 745 is supported within a recess 1030 partially formed in the upper housing 725 . The raised member 1025 , as well as the recess 1030 , join with mating portions 1035 and 1040 , respectively, of the opto housing 750 , as shown particularly In FIG. 11 A. In addition, as shown in both FIGS. 11A and 11B, the opto housing includes an angled bore 1045 symmetrical to the bore 1020 for supporting the second of the LEDs 730 which, like the first LED, illuminates the lower portion of the ball 710 so that diffuse light is directed onto the sensor 735 . As noted previously, diffuse light is presently preferred because of the improved contrast it provides on the light and dark sections of the ball 710 .
In addition, the lower housing 750 also includes a recess 1050 to receive the sensor 735 , as better appreciated in FIG. 11 D.
FIG. 11D, which is a cross-sectional side view of the upper and lower housings together with lens, sensor and window, illustrates the relationship between the key optical elements of this embodiment. In particular, the opto housing cover 725 can be seen to mate with the opto housing 750 , with the two opto housings cooperating to position and support the lens 745 in alignment between the ball 710 and the sensor 735 . The window 740 is interposed between the ball and the lens, and in those embodiments which use infrared illumination of The ball may be made from a material which appears black in the visible spectrum but is transparent to infrared frequencies, which allows extraneous visible light (such as might enter between the bail and retaining ring) to be filtered out. In addition, the retaining clip 760 can be seen on the underside of the lower housing 750 . Not shown in FIG. 11D are the bores through which the LEDs 730 illuminate the ball 710 .
To better understand the optical path of the embodiment shown in FIGS. 7-11, FIGS. 12A-12C show the operation of the optics in simplified form. In particular, in the simplified drawing of FIG. 12A, the ball 710 is retained within the ball cage 715 by the retaining ring 720 . A pair of LEDs 730 illuminate the lower portion of the ball, with the light diffusely reflected through a transparent portion onto the lens 745 and thence onto the sensor 735 . In addition, other aspects of this embodiment which can be appreciated from this simplified view are the seal formed by the retainer ring, which helps to prevent dust and dirt from entering the ball cage, and the transparent window which further assists in preventing dirt from blocking the optics.
Referring next to FIG. 12B, the optical arrangement for a classical lens in an in-line arrangement of ball, lens and sensor are shown. In particular, an area 1210 of the ball is illuminated from the LEDs discussed previously. Diffuse light from the illuminated portion of the ball passes through a lens 1220 and strikes a sensor 1230 . The lens, which may be made of glass or any suitable optical plastic such as polymethylmethacrylate (typically polished or molded such as by hot pressing), may be a simple biconvex lens having both radii equal to, for example, 2.37 mm where the thickness of the lens is on the order of 1.23 mm and the distance from the ball to the nearest lens surface is on the order of 4.35 mm. Similarly, the distance from the sensor to the nearest lens surface is on the order of 4.42 mm. In such an arrangement the field of view of ball is about 2.8 mm in diameter. The optically free diameter of the lens is preferably limited, and in the foregoing example may be limited to about 1.5 mm aperture. The optical limits may be imposed by mechanical or other means.
Referring next to FIG. 12C, the optical arrangement for a classical lens in a lateral arrangement of ball, lens and sensor are shown. This approach, which is presently preferred and shown in the second and third embodiments herein described, involves a folded light path. In particular, an area 1240 of the ball is illuminated from the LEDs discussed previously. Diffuse light from the illuminated portion of the ball passes through a portion of a piano-convex lens 1250 , which is hemispherical in an exemplary embodiment. As before the lens may be made of polylmethacrylate (PMMA), but now has a flat, mirrored back surface. The size of the mirrored area provides an aperture stop equivalent to that required in the in-line arrangement of FIG. 12B, and in the embodiment described herein may be, for example, on the order of 1.8 mm aperture where the field of view of the ball is again 2.8 mm, but the lens-to-ball distance is on the order of 3.2 mm and the lens to sensor distance is on the order of 3.3 mm. In this example, the radius of the lens may be on the order of 1.75 mm. The total deflection angle of the lens is not especially critical, and for the embodiment described may vary between seventy-two and ninety degrees without deterioration of optical performance. A baffle 1260 may be provided to ensure that no light from the ball strikes the sensor directly. In the event the sensor is covered with a protection layer (usually epoxy), the distance between the lens and the sensor may need to be increased by an amount of about one-third of the thickness of the protective layer. Such a simplified correction term is adequate for layers up to one millimeter thickness with a refractive index of 1.5±0.05. Alternatively, the surface of the protection layer may be curved to form a negative lens, which will act as a field flattener and thereby reduce the image field curvature. This would tend to improve the resolution and contrast in the border area of the sensor.
With reference next to FIG. 13, the operation of the sensor electronics of the embodiment shown in FIG. 7A can be better appreciated. In general, the electronics associated with the second embodiment described above is in some respects presently preferred over that associated with the first embodiment described above, although each approach has merit. In general, the electronics implemented in the second embodiment comprises an array of pixels composed of both the photodiode to detect the image and the circuitry both to perform the calculation and store the information, together with appropriate electronics to communicate that information to a host system. From the description of FIG. 5A, it will be apparent that the circuits of FIG. 13 are essentially a replacement for the sensor circuit 545 shown in FIG. 5 A. In particular, as shown in FIG. 13, the logic associated with the device of FIG. 7A includes a pixel matrix 1305 , which is typically an 11×11 array of photodiodes and associated circuits but could be substantially larger in at least some embodiments. The circuit also includes a current-based A/D converter circuit 1315 substantially similar to that shown in FIG. 5B but expanded to four data bits plus sign, an absolute value circuit 1320 substantially the same as shown in FIG. 5B (which supplies the sign for the 4 bit data word from the A/D converter), a top ring shift register 1325 and an analog mux 1330 , a right ring shift register 1335 and an associated plurality of two-to-four decoders (eleven for an 11×11 array) 1340 , data storage logic 1345 , a current reference circuit 1350 , and interface logic 1355 . In addition, the logic includes a first test shift register 1360 for the rows on the left of the matrix 1305 , together with a second test shift register 1365 for the columns in the bottom of the matrix. For a matrix of 11×11, each shift register is eleven bits, but it will be apparent that the size of the shift register could be varied over a very large range to correspond to the number of pixels on one side of the matrix. In addition, a plurality of test pads 1370 is also provided, as are V DD and V ss circuits. The A/D converter circuit for the exemplary embodiment described herein is preferably a sequential, asynchronous device to reduce the circuitry required for implementation, although in other embodiments a parallel converter may be preferred. In addition, in some embodiments a sample and hold circuit can be provided ahead of the A/D converter circuits.
In the logic of FIG. 13, all of the digital blocks operate under the control of the interface logic 1355 , which also interacts with the primary analog elements. In turn, the chip is typically controlled via a microcontroller, as illustrated previously. The interface logic uses only synchronous logic blocks. as is therefore capable of being controlled by a synchronous state machine with a counter, such as a seven bit counter for the embodiment of FIG. 13 . In addition, for the embodiment described no “power-on-reset” function is required, since the logic reaches a deterministic state after a predictably small number of cycles, such as about 150 cycles with the bidirectional (or input and output) “data” line forced high for the exemplary embodiment shown.
Referring next to FIG. 14, the architecture of the interface logic 1355 may be appreciated in greater detail. A control state machine 1400 , operating in connection with a seven bit counter 1405 , operates generally to select from among various inputs to place data on a bidirectional pad 1410 by control of a mux 1415 . The counter 1405 can be preset or can decrement its current count by means of a signal from the state machine 1400 . In addition, if the count in the counter 1405 is null, the state machine is forced to change state by means of a signal supplied to the state machine.
The inputs to the mux 1415 include pixel information on line 1420 , edge information on line 1425 , a check bit on line 1430 , or either wake up information on line 1435 or serial data out on line 1440 . Both the wake up information and the serial data out information are provided by a parallel to serial converter 1445 , which receives its input from a mux 1450 having, for the exemplary embodiment shown, a twelve bit output. The input to the mux 1450 can be either displacement data on line 1455 , or predetermined ID information, such as ID=HOD 1 on line 1460 . It will be apparent that the function of the mux 1450 is to select one of its two inputs for supply to the parallel-to-serial converter 1445 , and is controlled by the state machine 1400 . It will be noted that neither pixel information on line 1420 or edge information on line 1425 is latched in the exemplary embodiment, to allow real-time switching. However, it may be desirable in some embodiments to provide such latching. The check bit on line 1430 is toggled after any image sample, and allows the processor to determine whether the chip is synchronized to ensure proper communications.
The particular input chosen to be passed through the mux 1415 IS selected by control lines 1460 from the state machine 1400 , which also supplies direction information on line 1465 to the bidirectional pad 1410 to determine whether signals flow to or from the pad 1410 . If the state machine 1400 is seeking information from the pad 1410 , the incoming data can be latched into a D flip-flop 1470 , where the clock is controlled by the state machine 1400 . Data at the output of the flip-flop 1470 is then supplied to the state machine 1400 , a serial-to-parallel converter 1475 , and to a plurality of test image simulation circuits 1480 for diagnostics. The signals which can be supplied to the remainder of the circuitry from the serial-to-parallel converter 1475 include reference level and hysteresis, on line 1485 , dis_sample on line 1490 , and dis_idle on line 1495 .
Referring next to FIG. 15, the operation of the state machine 1400 is shown in greater detail in the form of a state diagram. As will be apparent from FIG. 14, the state machine is controlled from two inputs: one from the seven bit counter 1405 , when the counter reaches a null value, and another from data in from the bidirectional pad 1410 through the D flip-flop 1470 . In the drawing, “in” means that the microcontroller associated with the sensor chip must force a logical level on the data pad 1410 , while “out” means that the interface logic 1355 will drive a logical level on the “data out” line from the mux 1415 . Each box of the state diagram of FIG. 15 shows the name of the state as well as the operation performed, such as a pre-set to a certain value or a decrementing. In the exemplary embodiment shown, states will typically change on the rising clock edge, and control inputs are latched on the fall edge of the clock signal. Essentially, at the end of each cycle, the machine moves to the state for which the condition is true; but if no condition is true, the state remains unchanged for that cycle. Such a condition can occur, for example, when the machine forces the counter to decrement. It will be appreciated by those skilled in the art that the conventions used in the C programming language have also been used in FIG. 15 .
Operation begins at RESET step 1500 , typically following an initialization step. For the exemplary embodiment shown, a typical reset can occur by applying a predetermined number of clock cycles with the “data” line forced high. Alternatively, a pull up arrangement could be implemented and the data line forced low to achieve an equivalent result. The maximum number of cycles necessary to reach a known or “reset” state from an unknown, random starting state can be derived by inspection of FIGS. 13 and 14. For the embodiment shown, the maximum number of cycles necessary to reach a determined state is 143 , which occurs when the initial state is “wakeup”. For conservative simplicity, approximately 150 cycles may be used. Alternately, a more conventional reset can be provided. Following the RESET step, the state machine moves to one of seven selector states, SELECTOR1-SELECTOR7, indicated at reference numerals 1505 - 1535 , respectively, which allows the microcontroller to choose among different operations to be performed. If the SELECTOR1 state indicated at 1505 is selected, the next state is the SSAMPLE, indicated at 1540 . The SSAMPLE state is the first state of the displacement reading loop. In this state, “data” is driven with the “check_bit” value (shown as 1430 in FIG. 14 ). If the value of “dis_sample” on line 1490 (FIG. 14) is low, pixel currents from the pixel matrix 1305 (FIG. 13) are sampled on the failing edge of the clock signal CK in a manner described in greater detail hereinafter. Upon leaving the state, the “check_bit” signal on line 1430 (FIG. 14) is toggled and the displacement is latched into the parallel-to-serial register/converter 1425 . The displacement data is later shifted out. Following the SSAMPLE state, the state machine 1400 moves to the WAKEUP state 1545 , where “wake-up” information is put on “data”. For the exemplary embodiment shown, a wake-up occurs where there is sufficient X or Y movement to exceed the hysteresis programmed into the system. This can be expressed as “wake-up”=((X[3:0] AND hysteresis) OR (Y[3:0] AND hysteresis)≠0). If the result is a one, or high, the edges are latched in the pixels when “CK” is low. A high result means that the state machine moves to the GETDISP state 1550 ; a low result means that the state branches back to the SELECTOR1 state 1505 . The microcontroller is able to force the machine to branch to the GETDISP state 1550 by forcing up the “data” level, but the edges in the pixels will not be latched. The machine thereafter advances by returning to the SELECTOR1 state 1505 .
If the SELECTOR2 state 1510 was selected, the next state is RESETALL, indicated at 1555 . If “data” is high, a general reset is performed. All test shift registers (FIG. 13) and switches are reset to 0, and the hysteresis reference level is reset to B11110; likewise, sample is enabled, normal sleep mode is enabled, and the checkbit is cleared. However, if “data” is low, no operation is performed. The machine then advances to the next state, GETID, indicated at 1560 , and identification bits are put serially on “data”, with the most significant bit first, for example B000011010001. The machine next returns to the RESET state 1500 .
If the SELECTOR4 state was selected, and “data” is high, the machine advances to the FORCESHIFT state, indicated at 1565 . If “data” is high, the edges are latched in the pixels during the Low phase of “CK”, and the current edges replace the old edges. The machine then advances to the NOTFORCESLEEP state, indicated at 1570 , where, if “data” is Low the chip is in sleep mode during the Low phase of “CK”. On the next cycle the machine advances to the SETREFSW state, indicated at 1575 . In this state the values of different switches and reference levels (or hysteresis values) can be defined. In order of priority, dis_sample is set and, if high, no image sample is done at the “SSAMPLE” state and edges for the current image are frozen. The sensor chip is thus in a high power consumption mode. Next in priority, dis_idle is set, but only has meaning if dis_sample is low. If dis_sample is low and dis_idle is also low, edges for the current image are held only during the low phase of “CK” in the “SSAMPLE” state, during the “WAKEUP” state, and the first high phase of “CK” in the “GETDISP” or “SELECTOR1” states. If the dis_idle bit is low, the edges are held everywhere except in the high phase of “CK” in the “SSAMPLE” state. Those skilled in the art will recognize that power will be wasted if this bit is active. For the particular embodiment shown, the reference level, or hysteresis, is set by four bits, with MSB first. The machine thereafter returns to the RESET state 1500 when the counter 1405 (FIG. 14) reaches a zero.
If the value of “data” had been low, or “Idata” at the SELECTOR4 state, the machine would next have advanced to the GETIMAG state, indicated at 1580 . In this state, an image scan is performed by comparing pixel currents one by one with a reference current. The details of this operation have been treated generally in connection with the first embodiment, described above, and will be described in greater detail hereinafter. After the image scan is completed, the machine returns to the RESET state 1500 in response to a zero from the counter 1405 (FIG. 14 ).
If the SELECTOR5 state was selected, the machine would thereafter advance to the SETTEST state, indicated at 1585 . The SETTEST state is used for testing the operation of the pixel matrix 1305 . The machine will remain in this state for enough clock cycles to cycle through each column and row of pixels; thus, for an eleven by eleven matrix, the machine remains in the SETTEST state for twenty-two clock cycles. The bits on “data” are sampled and shifted in the test shift registers to create an artificial image, which may then be analyzed to ensure proper operation of the system. The machine thereafter advances to the RESET state 1500 in response to a null value in the counter 1405 .
If the SELECTOR6 state was selected, the machine would next advance to the SCANCOLOR state, indicated at 1590 . In this state color information is scanned in a manner analogous to the operation of the system in the GETIMAG state 1580 . Thereafter, the machine would advance to the RESET state 1500 in response to a null value in the counter 1405 . Similarly, if the SELECTOR7 state had been selected, and “data” was high, the machine would advance to the SCANEDGEX state, indicated at 1595 A, where “edge X” information is scanned. Alternatively, if “Idata” was present, the machine would advance to the SCANEDGEY state, indicated at 1595 B, where “edge Y” information would be scanned. The sequence of operation for the remainder of the system during the SCANEDGEX and SCANEDGEY states is the same as for the GETIMAG state 1580 . After either state, the machine returns to the RESET state 1500 in response to a null value on the counter 1405 (FIG. 14 ).
Set forth below in table form is the signal driven on the “data” lines of the bidirectional pad 1410 (FIG. 14) when the sensor of FIG. 13 is in the output mode:
STATE NAME
SIGNAL
SSAMPLE
check bit
WAKEUP
wakeup
GETDISP
serialout
GETID
serialout
GETIMAG
pixel info
SCANCOLOR
edge info
SCANEDGEX
edge info
SCANEDGEY
edge info
In addition, it is necessary to avoid any loops in the unused states of the machine. The state attribution table is shown below:
STATE NAME
STATE VALUE
RESET
′H00
WAKEUP
′H01
SELECTOR6
′H02
SELECTOR7
′H03
SETTEST
′H04
SETREFSW
′H05
SELECTOR2
′H06
SELECTOR3
′H07
SCANEDGEY
′H08
SELECTOR4
′H09
SELECTOR1
′H0A
SCANEDGEX
′H0B
′H0C
RESETALL
′H0D
′H0E
GETIMAG
′H0F
GETID
′H10
SELECTOR5
′H11
GETDISP
′H12
′H13
SSAMPLE
′H14
SCANCOLOR
′H15
′H16
′H17
FORCESHIFT
′H18
′H19
′H1A
′H1B
NOTFORCESLEEP
′H1C
′H1D
′H1E
′H1F
State values having no state name are unused; in addition, in the exemplary embodiment shown, the state machine has been designed to reset after only one clock cycle in the-event the machine enters into one of the unused states.
Referring next to FIG. 16, the organization and operation of the pixel matrix 1305 (FIG. 13) may be better understood. As previously noted, an 11×11 pixel matrix has been used in the second exemplary embodiment. The resulting 121 pixels are divided into four types: type P, which denotes a standard pixel with photodiode, amplifier, current comparator and digital memory for storing edge information; type D, which denotes a pixel with a diode and amplifier only; type E, which denotes an empty pixel; and type T, which is a test pixel biased like a type P or D, but with its output connections tied to test pads rather than connected to the displacement calculation circuitry. The type P pixels provide the conventional image data used by the remainder of the sensor. The type D are used to define border conditions and to provide its illumination current to neighboring pixels. The type E sensors are used for signal routing purposes. Finally, the type T pixels are accessible externally for test purposes only. From the arrangement of pixels in FIG. 16, it will be apparent that type P pixels predominate in the center of the sensor, while the type D pixels define a perimeter around the type P pixels. During any scan, the matrix is addressed row by row through incrementing of the column index, or:
(row# 0 , col# 0 ), (row# 0 , col# 1 , (row# 0 , col# 2 ) . . . (row# 0 , col# 10 ), (row# 1 , col# 0 ) . . . (row# 10 , col# 10 ).
It will be appreciated that, for the exemplary pixel arrangement shown in FIG. 16, the origin has been arbitrarily defined as the lower right corner.
During the various scans of the pixel matrix 1305 , various information will be provided from the various types of pixels. Set forth below in table form are the types of information expected from addressing the specified pixel type during the different types of scans, with the associated state of the state machine 1400 in parentheses:
Type P
Type D
Type E
Type T
Pixel
Current
Current
0 if I ref > 0
Current
Information
Comparison
Comparison
Comparison
(Get Image)
result
result
result
(I pix -I ref > 0)
(I pix -I ref > 0)
(I pix -I ref > 0)
Edge X
Edge X
1
1
Edge X
information
(comparison
(comparison
(scanedgex)
with the left)
with the left)
Edge Y
Edge Y
1
1
Edge Y
Information
(comparison
(comparison
(scanedgey)
with the top)
with the top)
Color
Color
1
1
1 (*)
Information
(scancolor)
In the exemplary embodiment shown, the value of the current I ref cannot be null to avoid floating nodes. The current I ref can be set through the reference level, or hysteresis, as described above in connection with the description of the state machine 1400 .
The entries in the table having an asterisk are valid only in the absence of current injection through the test pads. For test purposes, the interface 1355 (FIG. 13) can be placed in a special mode to force an artificial image. The artificial image is formed with pseudo-active pixels, which are of types D and T. at the crossings of two perpendicular active lines by entering two test words, one for lines and one for columns. The artificial image can be cleared with a data High during the RESETALL state 1555 .
Operation of the sensor of the present invention is fundamentally the recognition of edges and tracking those changes over time. As noted previously, an edge is defined as a difference of intensities between two adjacent black and white pixels. For the present invention, the difference of intensities is typically (though not necessarily) sensed as a difference in currents. With the optics and ball of the exemplary embodiment, the ratio between the currents corresponding to black and white spots is typically between 3 and 4 or at least larger than 2 in both the x and y directions, although smaller differences may also be acceptable in some embodiments. For purposes of discussion of this embodiment, an edge will be defined as laying between two photodetectors if the ratio of intensities of the two adjacent photodetectors is larger than two. By use of a differential approach, as mentioned briefly above as an alternative to the embodiment shown in FIG. 3, the edges can be detected independently of the absolute light intensity. In addition, differential sensing is less sensitive to gradients due either to lighting conditions or the curvature of the ball, as long as the fall-off in intensity for a ball surface of uniform color does not result in a ratio greater than two between two pixels.
The differential sensor shown in FIG. 17A is one approach to detecting the edges of the moving ball, and can be taken in conjunction with FIG. 17B, which shows a plurality of pixels P and two successive images I t and I t−1 at times t and t−1 where black and white pixels represent low or high reflected light levels, respectively, while hashed pixels represent pixels detecting an intensity change. A photodiode 1700 receives light input reflected off the ball, and provides accumulates charge in proportion to the light reaching It while the LEDs 730 (FIG. 7 A), which are typically pulsed, are on. The current is supplied to an amplifier 1705 . The amplifier 1705 amplifies the current enough to output a current I out sufficient to allow a comparison with the adjacent right and top pixels in a predetermined time period, such as 50 μs. Each pixel also sends its current to its bottom and left neighbors, as explained previously in connection with FIG. 4 and shown in FIG. 17 as 1710 A-B, 1715 , 1720 , 1725 , 1730 , 1735 , 1740 , and 1745 . The outputs of the various differential stages 1710 - 1745 can then compared in current comparators 1750 A- 1750 D, and the results of those comparisons can be latched into latches 1760 A- 1760 C, after conditioning through combinational logic 1765 - 1775 and activation of the latch operating signal nshift. Comparisons can then be performed while the LED is off, where the latches store data representing values for edges on the X axis (E x ), edges on the Y axis (E y ), and color of the pixel (C and its complement NC), but as they existed during the previous state. The stored data from the previous state may be represented as oE x , oE y , and oC.
For the exemplary embodiment shown herein, various assumptions have been made about the signal currents. First, to accurately detect edges, it has been assumed above that the ratio of currents corresponding to a black spot and a white spot are assumed to be at least two: thus, a value of two has been arbitrarily chosen for the current comparator, although a lower or higher value would also work. Second, it has been assumed for the exemplary embodiment that the mismatch between two adjacent photodiodes is less than twenty percent although it has been shown that the circuit works acceptably at least as low as a ratio of 1.7:1.
An edge is detected is the current in the sampled pixel is either twice or half the current in the neighboring pixel. In addition, color of the pixel is determined as high, or white, if the current in the pixel is either twice the current in the adjacent right cell or twice the current in the adjacent top cell. It will be apparent to those skilled in the art, from the teachings herein, that such a paradigm detects color in a sampled pixel only when an edge exists at its right or at its top, and tests only for white pixel. It is believed apparent that the invention includes extending detection to comparisons with other selected pixels and testing for black spots, and detailed discussion of such addition features is not believed necessary in this disclosure.
The pixel circuitry depicted in FIG. 17 also offers the additional feature of having test circuitry integrated into the sensor. A test current source I test indicated at 1785 has been provided to supply a reference signal in parallel with the charge amplifier 1705 . This permits injection of an image through the circuitry at the wafer test level, which reduces the amount of time required to test each wafer. In addition, as noted previously, a scanning scheme allows comparisons between the value of the analog output current of the charge amplifier with a programmable reference current. The reference current I ref , as noted previously, can be set by a four bit digital word supplied to control hysteresis. For the particular embodiment shown, if ail four bits of the hysteresis word are zero, I ref will be zero; but if all four bits are ones, I ref will be about 500 nA, which is substantially representative of the current amplifier in response to a pulse of white light for a suitable period.
Referring next to FIG. 18, the bidirectional pad of the present invention may be better appreciated. A DATA OUT signal, on line 1900 , is combined with a DIR signal on line 1905 in a NOR gate 1910 . The output of the NOR gate 1910 supplies a non-inverting gate to a transistor 1915 and an inverting gate to a transistor 1920 . Connecting between the respective source and drain of the transistors 1915 and 1920 is a pull down resistor 1925 , which may for example be on the order of 10-20K Ω. A diode 1930 is shunted across the source and drain of the transistor 1915 , the drain of which is tied to ground. The output of the transistor/pullup resistor stage is taken at the junction 1935 of the drain of the transistor 1920 and one end of the resistor 1925 . A second diode 1940 A is connected between ground and the junction 1935 and 1940 while a third diode 1940 B is connected between the voltage supply and the junction 1935 . A pair of splitter resistors 1945 A-B are series connected between the output pad 1950 of the sensor and the junction 1935 . A pair of diodes 1955 A-B and commonly connected to the junction between the pad 1950 and the resistor 1945 B, with the other terminals of the diodes connected to ground and the voltage supply, respectively. Finally, a data input from the pad 1950 (or external to the sensor) to the remainder of the interface logic 1355 is taken at the junction of the two resistors 1945 A-B, through two buffer inverters 1960 .
The arrangement shown in FIG. 18, while facilitating bi-directional communication between the sensor of the present invention and the external world, is particularly important because it allows reduction in pin count. In the exemplary embodiment described herein, particularly as shown in FIG. 7A, the sensor can be seen to have only four pins, which facilitates mounting and relating issues.
To achieve the goal of bi-directionality, the pull down resistor 1925 is switch between input and output states at appropriate times. The pad 1410 (FIG. 14) is controlled so that the pull down resistor 1925 is connected when the pad is in input mode—which occurs when the signal DIR on line 1905 is low. However, the resistor 1925 is disconnected when the Dad is in the output mode, caused by the signal DIR being high. It will be apparent to those skilled in the art that, if the data output signal on line 1915 is to be high, the state of the signal DIR is Important. However, if the signal on line 1915 is to be low, the state of the DIR signal is irrelevant. It will be appreciated by those skilled in the art that the delay associated with pad capacitance must be taken into account to achieve acceptable response times; for the exemplary embodiment described herein, the capacitance associated with the pad is about 20 pf.
Shown in FIGS. 19A and 19B are timing diagrams for various operational states of the system. FIG. 19A describes the main loop that is used to read displacements, while FIG. 19B describes the latching of a new image, as well as the imposition of sleep mode.
Referring next to FIGS. 20A-E, a third embodiment of the present invention may be better appreciated. The FIGS. 20A-E show the trackball in exploded perspective, top plan, front elevational, rear elevational and side elevational views, respectively, with like elements for the embodiment of FIGS. 7A et seq. having like reference numerals. This embodiment, which is also a trackball but is implemented as an external device rather than integrated into the remainder of a system such as laptop computer or other control device, includes an upper housing 2005 and a lower housing 2010 , best appreciated from the exploded perspective view of FIG. 20 A. The upper housing 2005 includes an angled aperture 2015 through which a ball such as the ball 710 may be inserted. A retaining ring 2017 may be provided to allow easy insertion and removal of the ball. A plurality of buttons or switches 2020 A-C may be provided for entering commands of pointing devices.
Enclosed within the housings 2005 and 2010 is a ball cage 2050 , as shown in FIGS. 21A-D, which supports the ball 710 . The ball cage is affixed to a printed circuit board 2051 by means of a pair of clips 2052 A-B in combination with a pair of positioning pins 2052 C-D, all of which extend through associated slots or holes in the printed circuit board 2051 . The lens 745 is held in position by a metallic clip 2053 which extends from the underside of the PC board 2051 , through a pair of slots therein, and clips into position on a pair of ears 2054 on the ballcage. The ball rests on three bearings 2055 , each of which is maintained within one of three posts 2060 A, 2060 B and 2060 C. Unlike similar supports known in the art in which the bearing typically are located in a horizontal plane, the post 2060 C is shorter than the posts 2060 A and 2060 B so that the bearings define a plane sloped at an angle of approximately 30 degrees. This angled support cooperates with the upper housing 2005 to cause the ball to extend through the angled aperture 2015 , which allows an improved, ergonomic positioning of the thumb relative to the remainder of the hand, such that the fingers and thumb of the hand are in a substantially neutral posture while operating the trackball. In addition, a pair of arcuate supports 2065 may be provided to increase the rigidity of the baseplate, and may provide some absorption of force in the event the device is dropped. An aperture 2070 is provided through which the ball may be illuminated and viewed by the same optics and same electronics as is used with the embodiment of FIG. 7 A. The sensor 735 is held in place by a further pair of clips 2056 which are typically formed as part of the ball cage 2050 .
With particular reference to FIGS. 21C and 21D, the operation of the optics may be better appreciated. FIG. 21C shows the ball cage 2050 in rear elevational view, while FIG. 21D shows a portion of the ball cage 2050 in relation to a ball such as the ball 710 . A window 2075 is provided in the optical path between the ball 710 and the sensor 735 , with the lens 745 providing a folded light path as in the third embodiment. Referring again to FIG. 21B, the location for the sensor 735 is provided by a mounting boss 2080 , while a pair of cylindrical ports 2085 A-B are provided into which a pair of LEDs such as the LEDs 730 of FIG. 7A may be inserted to illuminate the ball 710 through ports 2090 A and 2090 B.
Referring next to FIG. 22. a further embodiment of the present invention may be appreciated. The embodiment of FIG. 22 is particularly of interest because it does not use a speckled ball or other speckled pattern, but at the same time works on the same principles as the remaining embodiments disclosed herein. In particular, a housing 2200 includes an orifice 2205 into which a window 2210 may be placed, although the window is neither necessary nor preferred in all embodiments. A prism 2215 is also supported within the housing 2200 at a position which is optically aligned with the window 2210 . In an exemplary embodiment the prism 2215 is a right angle prism positioned with its hypotenuse face placed parallel to (or as a replacement for) the window 2210 . One or more LEDs are positioned in line with one of the right angle faces to cause total internal reflection of the light emitted by the LEDs off the inside of hypotenuse face of the prism 2215 , in the absence of interference. Optically aligned with the LEDs, but on the side of the other right angle face of the prism 2215 , is a lens 2220 , which may be a biconvex lens. The prism may be of any suitable angle which provides for total internal reflection: i.e., the incidence angle of the light is greater than arcsin(1/n), where “n” is the refractive index of the prism material. In the exemplary embodiment, where the prism may be made of PMMA, this angle is about forty-two degrees from perpendicular. The window 2210 may be provided to serve as a filter for visible light, and also to provide a more scratch resistant surface than the prism 2215 ; in at least some embodiments it is useful to affix the window directly to the prism.
Positioned on the opposite side of the lens 2220 from the prism 2215 and optically aligned with it is a sensor such as the sensor 735 . During operation, a finger (not shown) may be placed on the window 2210 and moved thereover. In the absence of a finger, light from the LED enters the prism and strikes the top surface of the prism at an angle greater than 42 degrees from perpendicular, thus causing total internal reflection. When a finger is present, the ridges of the fingerprint contact the glass, canceling the total reflection in the contact areas. By properly adjusting the focal length of the lens 2220 and the optical path length from the window 2210 to the sensor 735 , an image of the finger's ridges and whorls—i.e., the fingerprint—may be formed on the sensor 735 . In this manner the movement of the light and dark spaces of the fingerprint over the window 2210 yields the same edge movement over the pixels of the sensor 735 as occurs with the movement of the ball 710 , allowing cursor movement to be controlled merely by the movement of a finger. It will be appreciated by those skilled in the art that the linear optical path of FIG. 22 may be made more compact by providing a more complicated prism which folds the light path. In at least some such embodiments, a lens may be formed integrally with the prism to focus the image on the sensor, and one of the right angle surfaces of the prism itself may provide the window against which the finger may be placed. In other embodiments, the lens may be eliminated simply by placing the finger against the hypotenuse of a right angle prism, which permits a light source on one of the right angle sides to illuminate the finger, with the reflected light illuminating a sensor of the type described above. In each of these embodiments the resulting image on the sensor is the result of frustrated total internal reflection, wherein the presence of the light and dark spots of the illuminated finger prevent total reflection of the illuminating light.
In addition to providing an elegantly simple solution for cursor control, detection of the fingerprint ridges also providing a method of detecting switch activity. By increasing finger pressure on the window or prism, the percentage of dark areas increase. A thresholding circuit may be provided such that, by an increase in dark areas in excess of the threshold, a “switch” activity may be detected. It will also be appreciated that the embodiment of FIG. 22 provides an effective, efficient device for identifying fingerprints, when combined with suitable electronics for storing and comparing appropriate images. Those skilled in the art, given the teachings herein, will recognize that numerous other alternatives also exist.
It is also possible to create an optical mouse which does not require a ball by using a similar imaging technique. A pattern, such as that on a table or other suitable printed figure having sufficient numbers of dark and light areas of sufficient size, can be detected in much the same manner as a fingerprint, although the particular components of the device are somewhat different. With reference to FIG. 23A-B, an optical mouse is shown which uses the same principles as discussed in connection with the second and third embodiments discussed previously. The upper housing and most of the lower housing have been removed for clarity from the device shown in FIG. 23, although appropriate housings are generally well known in the art; see, for example, FIG. 2 of U.S. patent application Ser. No. 672,090, filed Mar. 19, 1991 and assigned to the assignee of the present application, the relevant portions of which are incorporated by reference. As before, like components are given like numerals. In particular, an optical assembly 2290 includes an optical housing 2300 having a pair or angular bores 2310 A-B each of which receives, respectively, one of the LEDs 730 . An upper central bore 2320 extends from the top of the optical housing 2300 and part way therethrough until it communicates with a lower central bore 2330 . The lower central bore extends through the bottom of the optical housing 2300 , but is smaller in diameter than the upper central bore 2320 so that the lower central bore fits between the angular bores 2310 A-B, and is typically spaced symmetrically therebetween. The purpose of the central bore 2360 is to provide a shutter, and also to prevent stray light from reaching the sensor. A plate or window 2340 is affixed by any suitable means to the bottom of the housing 2300 . The plate 2340 is transparent to the frequency of light emitted by the LEDs 730 , and may be made of any suitably transparent material which is also scratch resistant such as plastic or glass.
The lens 745 is positioned within the upper central bore 2320 , which is typically sized to center the lens 745 above the lower central bore 2330 . An aperture plate 2350 , typically of substantially the same outer diameter as the upper central bore 2320 , fits into the upper central bore 2320 to fixedly position the lens 745 . The aperture plate 2350 further includes a central bore 2360 which communicates light passing through the lens 745 to the sensor 735 , positioned above the aperture plate 2350 . The central bore 2360 may also be conical, with the narrower portion at the bottom. A retaining ring 2370 , which fastens to the top of the optical housing 2300 by any suitable means, such as clips or screws, maintains the relative positions of the sensor 735 , aperture plate 2350 and lens 745 .
The assembly 2290 is positioned within the upper and lower housings of a mouse so that the plate or window 2340 is positioned above a speckled pattern of the same criteria as that on the ball 710 , although in this instance the pattern is provided on a pad, tabletop, or other suitable, substantially flat surface. A portion of a suitable lower housing is shown at 2380 . As the mouse is moved over the pattern, the light from the LEDs 730 is directed through the plate 2340 onto the pattern, and in turn is directed through the plate 2340 , up through the lower central bore 2330 and through the lens 745 . The lens then images the pattern on the sensor 735 in the same manner as discussed previously, so that movement may be readily detected by the changes in position of the edges in the pattern. While the exemplary embodiment has two LEDs, in at least some embodiments only a single LED is required.
While the foregoing design provides a simple and elegant design for a mouse capable of detecting motion, it typically requires a pattern having speckles meeting the criteria previously discussed. However, by altering the optical components to resolve small pattern elements, it is also possible to provide a pointing device which can detect movement over an object such as everyday paper, where the weave of the paper provides the detected pattern.
Having fully described a preferred embodiment of the invention and various alternatives, those skilled in the art will recognize, given the teachings herein, that numerous alternatives and equivalents exist which do not depart from the invention. It is therefore intended that the invention not be limited by the foregoing description, but only by the appended claims.
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A dual-layer optical ball for use in a cursor control pointing device. The ball is illuminated by a light source that emits light signals at, at least, a first wavelength, the ball having an inner layer surface that is capable of diffusing a light signal and an outer layer having a substantially smooth surface that surrounds the inner layer. The outer layer is substantially transparent to light at the first frequency. The inner layer diffuses the light signals at different intensities depending upon an the area of the inner surface that is illuminated.
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CROSS-REFERENCE TO RELATED APPLICATION
The present document is based on and claims priority to U.S. Provisional Application Ser. No. 60/889,072, filed Feb. 9, 2007.
BACKGROUND
In many well related operations, a variety of devices and systems are used in performing oilfield services. Some applications utilize the devices and systems in simultaneous operations (SIMOPS) at a given well site. The well site may have multiple wellheads with various operations being performed simultaneously. For example, well stimulation operations can be performed concurrently with perforation operations and drilling operations.
The multiple wellheads at which simultaneous operations are performed often are in close proximity to each other. Additionally, the simultaneous operations can be performed by several different service companies. Because of the concurrent service operations and the close proximity of wellheads, the simultaneous operations potentially can create hazards. For example, breakages, ruptures, or other failures at one wellhead can create detrimental effects at adjacent wellheads. Attempts have been made to create a barrier between operations by erecting panels of steel. However, such panels are heavy, difficult to move from one position or location to another, and the installation of such panels proves labor and time intensive.
SUMMARY
In general, the present invention provides a system and method for use in performing oilfield service operations. A safety shield is formed with a portable stand and at least one lightweight impact panel. The stand and the at least one lightweight impact panel enable easy movement of the safety shield from one well site location to another as needed during well service operations, e.g. during multiple simultaneous operations. The safety shield can be used to provide protection during individual operations and/or to segregate and protect independent operations from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
FIG. 1 is a perspective front view of one example of a safety shield having a plurality of lightweight impact panels, according to an embodiment of the present invention;
FIG. 2 is a back view of the safety shield, according to an embodiment of the present invention;
FIG. 3 is an overhead schematic view of a well site undergoing simultaneous operations with a safety shield deployed in one example configuration, according to an embodiment of the present invention;
FIG. 4 is an overhead schematic view of a well site undergoing simultaneous operations with a safety shield deployed in another example configuration, according to another embodiment of the present invention; and
FIG. 5 is an overhead schematic view of a well site undergoing simultaneous operations with a safety shield deployed in another example configuration, according to another embodiment of the present invention.
DETAILED DESCRIPTION
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The present invention generally relates to a lightweight portable safety shield useful in oilfield service operations and very well suited for simultaneous operations. The safety shield comprises a portable stand, such as a fabricated stand, fitted with one or more impact panels. The impact panels are made of a lightweight material that is easy to move. In one embodiment, the lightweight impact panels can be hand carried to facilitate quick and easy movement of the safety shield from one well site location to another. Depending on the size of the safety shield, the impact panels can be moved while joined with the portable stand or separated from the portable stand.
The lightweight nature of the portable safety shield enables rapid and inexpensive set up and tear down to facilitate deployment and movement of the portable shield from one location to another. By way of example, the lightweight panels can be constructed from a non-metallic material that is substantially lighter than steel. In one embodiment, the lightweight panels are constructed from a Kevlar® fiber material, such as a sheeted Kevlar® fiber material, available from the DuPont™ corporation, or similar lightweight, impact resistant materials.
The lightweight portable safety shield provides short-term impact protection at the well site to provide well site workers with enough time to get out of harms way in the event of a problem at one of the wells. The safety shield can be used for an individual operation, e.g. a maintenance operation, or it can be used in a simultaneous operations field to segregate and protect the independent operations from each other.
Referring generally to FIG. 1 , one embodiment of a lightweight, portable safety shield 20 is illustrated. In this embodiment, shield 20 comprises a stand or framework 22 , such as a fabricated stand. One or more lightweight impact panels 24 are mounted to the stand 22 . The impact panels 24 can be mounted to stand 22 via a plurality of fasteners 26 which may take a variety of forms depending on the construction of stand 22 and impact panels 24 . For example, fasteners 26 may comprise hooks, pins and corresponding recesses, bolts, and other suitable fasteners. The fasteners 26 can be selected to enable quick connection and disconnection of the impact panels 24 and stand 22 to further facilitate movement, transport, and/or storage.
Additionally, stand 22 can be constructed in sections 28 to enable selective changing or adjustment of the stand configuration and the relative orientation of the lightweight impact panels 24 to accommodate a variety of wellhead and space constraints. The individual sections 28 can be connected together by appropriate connectors 30 . By way of example, connectors 30 may comprise hinges that enable the sections 28 of stand 22 to be pivoted relative to one another. A variety of securing devices 32 , such as bolts, pins, or other fasteners, also can be used to secure stand 22 to a desired surface 34 , such as a surface of the earth or a platform.
The stand 22 can be fabricated in a variety of sizes and configurations depending on the environment and applications in which it is used to provide protection. As illustrated in FIG. 2 , for example, the stand 22 can be fabricated with a variety of vertical elements or legs 36 that are connected by transverse structural members 38 . The transverse structural members 38 may be arranged horizontally or at other angles selected to achieve a desired structural strength.
In FIG. 3 , one embodiment of a well site at which safety shield 20 can be implemented is illustrated. In this embodiment, the safety shield 20 is deployed at a simultaneous operations field 40 . By way of example, field 40 has multiple wellheads 42 , 44 , 46 , 48 , 50 at which various well related operations are being performed concurrently. For example, a well stimulation operation, e.g. a fracturing operation, can be conducted at wellhead 42 while wellhead 44 is in production. Additionally, a perforating operation can be performed at wellhead 46 , and a drilling operation can be conducted from a drilling platform 52 at wellhead 50 .
In this particular example, one embodiment of safety shield 20 is deployed in proximity to wellhead 42 where well stimulation operations are being performed. Safety shield 20 is deployed in a configuration that segregates wellhead 42 from the adjacent wellheads 44 , 46 , 48 , 50 and provides protection for any workers/personnel that are active by these other wellheads. In the event of a problem, such as a failure in treating lines at wellhead 42 , safety shield 20 protects the surrounding area from potentially impacting materials.
It should be noted that the simultaneous operations field 40 is provided as one example. The number of wellheads, placement of the wellheads, type of operations, actual services being conducted simultaneously, and other well related factors can vary from one application to another. Additionally, the configuration and the size of safety shield 20 can vary according to environment, topography, wellhead and operations being conducted. Additional safety shields 20 also can be deployed around other wellheads, or the sequence of service operations can be selected to accommodate movement of one or more safety shields 20 .
Also, the geometry, orientation and number of safety shield sections 28 can be changed according to the environment, operations being performed, and orientation of the wellheads at a particular well site. As illustrated in FIG. 4 , for example, safety shield 20 can be installed around an entire wellhead, such as wellhead 42 . In the illustrated embodiment, safety shield 20 establishes a circumference around the wellhead undergoing fracturing operations. The safety shield also can be used to create a circumference around wellhead 46 undergoing perforation operations or around other wellheads as suited for a given application. In the embodiment illustrated in FIG. 4 , safety shield 20 comprises four sections 28 , however other numbers of sections can be utilized to create the circumference or other shield configuration.
The use of safety shield 20 is not limited to simultaneous operations. As illustrated in FIG. 5 , for example, an embodiment of safety shield 20 is deployed in an individual oilfield service operation. In the example illustrated, safety shield 20 is used in a well stimulation operation at a well stimulation site 54 . The equipment used at site 54 can vary from one service application to another. In this example, however, the well stimulation site may utilize frac tanks 56 , a PCM (precision continuous mixer) 58 , a blender 60 , a chemical tank or hopper 62 , a sand tank or hopper 64 , and multiple frac pumps 66 , 68 , 70 , 72 , 74 , 76 . The frac pumps are connected with high-pressure treating iron 78 .
The safety shield 20 can be set up and/or moved quickly and easily to provide desired protection at a variety of locations throughout well stimulation site 54 . If, for example, one of the frac pumps requires maintenance during the well stimulation operation, personnel generally service the subject frac pump, e.g. frac pump 70 , while well stimulation operations continue. The safety shield 20 provides impact protection for the personnel working on frac pump 70 by segregating them from the neighboring treating iron 78 and the surrounding frac pumps. The safety shield 20 provides protection that gives workers time to move away from potential harm. Additionally, the safety shield 20 is easy to move from one location to another to accommodate, for example, maintenance of other frac pumps. In many applications, the lightweight impact panels 24 and stand 22 enable the safety shield 20 or safety shield components to be hand carried from one location to another. This portability and ease of setup/tear down greatly reduces the cost and improves the efficiency of providing a safety shield at desired locations throughout a given well site.
One or more safety shields 20 can be deployed in a variety of configurations for use at many types of well sites. The actual size and configuration of each safety shield can be selected according to the parameters of a given well site environment or well site application. The one or more safety shields also can be integrated with individual or simultaneous operations and can be used in cooperation with many types of well equipment.
Accordingly, although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Such modifications are intended to be included within the scope of this invention as defined in the claims.
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A technique enables improved performance of oilfield service operations. A protective shield is formed with a portable stand and at least one lightweight impact panel. The one or more lightweight impact panels enable easy movement of the safety shield from one location to another at a given well site or between different well sites, thus affording protection with a minimum of labor and set up time. The safety shield can be used to provide protection during individual operations and/or to segregate and protect independent operations from each other during multiple, simultaneous operations.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a positioning system and method for a precise stage and more particularly to a positioning system and method for a precise stage by means of electron beam scanning.
2. Description of the Prior Art
With requirements of high precision for industrial machinery and measuring instruments, development of precision machinery, semiconductor industry, micron technology or nanotechnology all emphasize on micronization and precision, wherein positioning technique and instruments with high precision are necessary for processing machinery, semiconductor fabrication and electronic information device.
Generally, when a high precision stage is rotating or multi-axis positioning, it may lead to a problem of mechanical drift. The state-of-art solutions and disadvantages thereof are described below:
(1) Using an optical interferometer to detect precision movement of the moving stage for high precision positioning: it cannot be arranged on the rotating axis of the moving stage. (2) Using an optical scale for calibration: precision thereof is insufficient and it is unable to measure eccentricity of the rotation. (3) Using a mechanical axis with air bearing: although to 30 nm precision, it must be operated under standard atmosphere and is too large-sized to use in small space. (4) Using a vacuum gauge for calibration: if the stage is designed for multi-dimensional movement with tilted angle, the mechanical design is very difficult and complex and therefore is unpractical.
SUMMARY OF THE INVENTION
It is an aspect of the present invention to provide a positioning system and method for a precise stage and pattern used thereof, which can be applied to multi-dimensional moving stage with complex structure to nanometer scale and can overcome the problem of mechanical drift when the moving stage is rotating or multi-axis positioning.
According to an embodiment, the positioning system and method for a precise stage comprises: a designed pattern placed on a moving stage, wherein the designed pattern comprises a plurality of gradually wider marks radially arranged with a space therebetween; an electron beam column, for generating a focused electron beam; a scanning unit connected to the electron beam column, for adjusting the focused electron beam to perform two-dimensional pattern scanning over the designed pattern so as to generate a reflected electron signal; an electron detection unit, for detecting the reflected electron signal; and a control unit connected to the moving stage, the electron beam column, the scanning unit and the electron detection unit, wherein the reflected electron signal is generated from the two-dimensional pattern scanning of the focused electron beam over the gradually wider marks and the space therebetween; the reflected electron signal is converted by the control unit to generate a clock signal, and the control unit adjusts the movement of the moving stage according to pulse width of the plurality of the clock signals, wherein the trace of the two-dimensional pattern scanning can be circle or ellipse.
According to another embodiment of the present invention, in a positioning system for a precise stage, a designed pattern is placed on a moving stage and is maintained a constant distance from a specimen placed on the moving stage, wherein the designed pattern comprises: a plurality of gradually wider marks radially arranged with a space therebetween.
According to another embodiment, the positioning method for a precise stage comprises: fixing a designed pattern on a moving stage, wherein the designed pattern comprises a plurality of gradually wider marks radially arranged with a space therebetween; using an electron beam to perform two-dimensional pattern scanning over the designed pattern so as to generate a reflected electron signal; detecting the reflected electron signal; and converting the reflected electron signal to a clock signal, and adjusting the movement of the moving stage according to the designed pattern, two-dimensional pattern scanning and pulse width of the plurality of clock signals.
The objective, technologies, features and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings, wherein certain embodiments of the present invention are set forth by way of illustration and examples.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the accompanying advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic diagram illustrating the positioning system for a precise stage according to an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating the designed pattern and the circle trace scanning according to an embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating a clock signal according to an embodiment of the present invention;
FIG. 4 a to FIG. 4 c are schematic diagrams illustrating corresponding relationship between the designed patterns and the circle trace scanning according to three embodiments of the present invention;
FIG. 5 a to FIG. 5 c are schematic diagrams illustrating the clock signals generated from circle trace scanning respectively according to FIG. 4 a to FIG. 4 c;
FIG. 6 is a schematic diagram illustrating the designed pattern and the circle trace scanning according to another embodiment of the present invention;
FIG. 7 is a schematic diagram illustrating the clock signal according to another embodiment of the present invention;
FIG. 8 a and FIG. 8 b are schematic diagrams illustrating the designed pattern and the circle trace scanning according to another embodiment of the present invention;
FIG. 9 a and FIG. 9 b are schematic diagrams illustrating the clock signal generated from the circle trace scanning respectively according to FIG. 8 a to FIG. 8 b ; and
FIG. 10 is a flowchart illustrating the positioning method for a precise stage according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The detail description is provided below and the preferred embodiments described are only for the purpose of description rather than for limiting the present invention.
FIG. 1 is a schematic diagram illustrating the structure of the positioning system for a precise stage according to an embodiment of the present invention. As shown in FIG. 1 , the positioning system for a precise stage 10 comprises a designed pattern placed on a moving stage 14 . Referring to FIG. 2 , a schematic diagram illustrating the designed pattern according to one embodiment of the present invention, the designed pattern 12 comprises a plurality of gradually wider marks arranged radially; in one embodiment, there are four gradually wider marks, but not limited to this. The gradually wider mark is a fan-shaped mark 121 and there is a space 122 between two adjacent fan-shaped marks; an electron beam column 16 is arranged above the moving stage 14 for generating a focused electron beam 18 and using a scanning unit 26 to control the focused electron beam 18 to perform two-dimensional pattern scanning over the designed pattern 12 on the moving stage 14 to generate a reflected electron signal 20 . In one embodiment, the two-dimensional pattern scanning is circle trace scanning 28 or ellipse trace scanning, but not limited to this. As shown in FIG. 2 , the fan-shaped mark 121 and the space 122 are scanned by the circle trace scanning 28 ; an electron detection unit 22 , for detecting scatter electron signal 20 which comprises secondary electron signal and backscattered electron signal, but not limited to this; and a control unit 24 connected to the moving stage 14 , the electron beam column 16 , the scanning unit 26 and the electron detection unit 22 .
In one embodiment, the moving stage 14 comprises a three-axis moving stage and two rotating stages for horizontal rotation and vertical rotation, wherein the moving stage 14 is used for placement of a specimen (not shown in the picture) and the designed pattern 12 is arranged near the specimen with a specific distance so that the displacement of the focused electron beam 18 over the designed pattern 12 is equal to the displacement of the specimen.
Continue the description above, the control unit 24 records the shape of the designed pattern 12 and outputs a control signal for controlling the scanning trace of the scanning unit 26 and further converting the electron signal 20 detected by the detection unit 22 to a clock signal 30 so as to adjust the displacement of the moving stage 14 according to time-varying offset of the designed pattern 12 , which can be calculated based on the shape of the designed pattern 12 , scanning trace and clock signals.
In the present invention, because of distinctly different electrical properties between the designed pattern 12 and the space 122 , when the electron signal 20 generated from the circle trace scanning 28 of the focused electron beam 18 over the designed pattern 12 is converted to the clock signal 30 by the control unit 24 , as shown in FIG. 3 , there is high and low voltage change of the clock signal 30 . In one embodiment, when the focused electron beam 18 scans over the fan-shaped mark 121 , the clock signal 30 appears as a square pulse 32 with high height and width and the digital value is displayed as 1; when the focused electron beam 18 scanned over the space 122 of the designed pattern 12 , there is no square pulse 32 fluctuated and the digital value is displayed as 0.
There are four examples of fan-shaped marks in respect of the designed pattern, which are arranged radially and generate different clock signals based on the offset of the designed pattern. Referring to FIG. 4 a , the four fan-shaped marks are respectively marked as the fan-shaped mark 121 a , 121 b , 121 c and 121 d . In one embodiment, the fan-shaped mark 121 a and 121 c , toward the X direction, and the fan-shaped mark 121 b and 121 d , toward the Y direction, gradually grow wider away from the radiating center o, wherein the fan-shaped mark 121 a , 121 b , 121 c and 121 d are arranged with equal space therebetween.
As shown in FIG. 4 a , if the center of the circle trace scanning 28 corresponds to the radiating center o of the four fan-shaped marks 121 a , 121 b , 121 c and 121 d , because the scanning trace of the focused electron beam 18 over each fan-shaped mark 121 a , 121 b , 121 c and 121 d is the same, the each square pulse 32 a , 32 b , 32 c and 32 d of the clock signal 30 as shown in FIG. 5 a has equal width and distance therebetween, which means the corresponding relationship between the designed pattern and clock signal is correct and therefore the clock signal is correct.
When there is offset generated to the designed pattern (i.e. generated to the moving stage), the trace of the focused electron beam 18 scanning over the fan-shaped markers 121 a , 121 b , 121 c and 121 d changes. Take X direction offset of the designed pattern for example, as shown in FIG. 4 b , the traces of the circle trace scanning 28 of the focused electron beam 18 over the fan-shaped marker 121 a and 121 c are different so that the width of the pulse 32 a ′ and 32 c ′ of the clock signal 30 ′ as shown in FIG. 5 b is different and the distance between the adjacent pulse 32 a ′, 32 b ′, 32 c ′ and 32 d ′ differ; time-varying offset of the moving stage 14 (as shown in FIG. 1 ) can be deprived from comparison between the width of the pulse 32 a ′, 32 b ′, 32 c ′ and 32 d ′ of the clock signal 30 ′, and the width of the pulse 32 a , 32 b , 32 c and 32 d of the clock signal 30 , for adjusting the displacement of the moving stage 14 , which makes the designed pattern 12 on the moving stage 14 capable of generating the correct clock signal 30 (as shown in FIG. 5 a ) when the designed pattern is scanned.
In another embodiment, offset can be generated along the X direction and Y direction. As shown in FIG. 4 c , the traces of the circle trace scanning 28 of the focused electron beam 18 over the fan-shaped marker 121 a , 121 b , 121 c and 121 d are different, thereby changing the width of the pulse 32 a ″, 32 b ″, 32 c ″ and 32 d ″ of the clock signal 30 ″ (as shown in FIG. 5 c ); offset along the X direction and Y direction of the moving stage 14 can be derived from the change of the sequence and pulse width.
Continuing the description above, in order to distinguish sequence relationship between the each pulse 32 of the clock signal 30 for better analysis, there is at least a groove formed on one of the fan-shaped markers 121 ; when the focused electron beam 18 scans over the fan-shaped marker 121 with the groove, the pulse 32 is not a smooth square wave but a rough square wave. FIG. 6 shows a schematic diagram illustrating the designed pattern 12 and the circle trace scanning 28 according to another embodiment of the present invention, wherein the designed pattern 12 comprises the four fan-shaped markers 121 a , 121 b , 121 c , and 121 d and there is a groove 34 formed on the fan-shaped marker 121 d . FIG. 7 shows a schematic diagram illustrating the clock signal 30 according to another embodiment of the present invention, wherein the focused electron beam 18 scans over the designed pattern as shown in FIG. 6 and the center of the circle trace scanning 28 corresponds to the radiating center o of the four fan-shaped markers 121 a , 121 b , 121 c , and 121 d . As shown in FIG. 7 , the width of the each pulse 32 a , 32 b , 32 c , 32 d of the clock signal 30 and the distance therebetween is equal, wherein a fluctuation 36 appears over the wave top of the pulse 36 due to the groove 34 of the fan-shaped marker 121 d , thereby confirming the corresponding relationship between the four fan-shaped markers 121 a , 121 b , 121 c , 121 d and the each pulse 32 a , 32 b , 32 c , 32 d of the clock signal 30 .
Distinguishing standard, that is to say, the corresponding relationship between the fan-shaped markers and the clock signal, is not limited to the groove 34 formed on the fan-shaped marker 121 ; it also can be protrusion formed thereon. On the other hand, the fan angle of the fan-shaped marker may be too large or too small for sequencing the clock signal 30 so that a 45 degree fan angle of the fan-shaped marker 121 is designed for reducing deviation according to one embodiment.
Four gradually wider markers arranged radially according to aforementioned embodiments are exemplified for specifications of the designed pattern, but not limited to this, wherein the designed pattern 12 can comprises two, three, four and above gradually wider markers. FIG. 8 a and FIG. 8 b shows schematic diagrams illustrating the designed pattern and the circle trace scanning, wherein the designed pattern 12 comprises three fan-shaped markers arranged radially, named the fan-shaped marker 123 a , 123 b , 123 c , which grow wider gradually away from the radiating center o and are arranged with a equal space therebetween.
FIG. 9 a and FIG. 9 b are schematic diagrams illustrating the clock signal 30 generated from the circle trace scanning 28 over the designed pattern 12 respectively according to FIG. 8 a to FIG. 8 c . If the center of the circle trace scanning 28 corresponds to the radiating center o of the four fan-shaped marks 121 a , 121 b , and 121 c , because the scanning trace of the focused electron beam 18 (as shown in FIG. 1 ) over each fan-shaped mark 121 a , 121 b , and 121 c is the same (as shown in FIG. 9 ), the each square pulse 52 a , 52 b , 52 c of the clock signal 30 has equal width and the distance therebetween, which means the corresponding relationship between the designed pattern 12 and clock signal 30 is correct and therefore the clock signal 30 is correct. When there is offset generated to the moving stage, as shown in FIG. 9 b , the trace of the circle trace scanning 28 of the focused electron beam 18 over the fan-shaped markers 123 a , 123 b , and 123 c changes, and the width of the pulse 52 a ′, 52 b ′ and 52 c ′ also changes; offset of the moving stage 14 can be deprived from vector projection calculation based on change of pulse width and sequence.
In the present invention, spot size of the focused electron beam generated from the electron beam column depends on resolution of the positioning system for a precise stage; current value of the focused electron beam is used for determining signal-to-noise ratio. Besides, in order to increase signal-to-noise ratio, multi-petal gradually wider markers can be adopted to increase sampling speed while scanning.
FIG. 10 shows a flowchart illustrating the positioning method for a precise stage according to one embodiment of the present invention, wherein a positioning method for a precise stage comprises: fixing a designed pattern on a moving stage (Step S 40 ), wherein the designed pattern comprises 4 gradually wider markers arranged radially; using a focused electron beam to perform the two-dimensional pattern scanning over the designed pattern to generate a reflected electron signal (Step S 42 ); using an electron detection unit to detect the reflected electron signal (Step S 44 ); converting the reflected electron signal to a clock signal (Step S 46 ); and calculating the time-varying offset of the designed pattern according to the shape of the designed pattern, scanning trace and pulse width of the plurality of clock signals, for adjusting the displacement of the moving stage.
The present invention uses the focused electron beam to scan the specific designed pattern to generate a reflected electron signal and uses the electron detection unit to detect the reflected electron signal, thereby further determining whether there is offset generated to the designed pattern so as to adjust the displacement of the moving stage, which enables default results of the clock signal while scanning the designed pattern via the adjusted scanning trace. This positioning system for a precise stage can be applied to nanoscale positioning of the multi-dimensional moving stage with complex structure and overcome the problem of mechanical drift when the stage is rotating or multi-axis positioning.
While the invention is susceptible to various modifications and alternative forms, a specific example thereof has been shown in the drawings and is herein described in detail. It should be understood, however, that the invention is not to be limited to the particular form disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims.
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A positioning system for precise stage is provided. It includes a designed pattern on a stage; an electron beam column generating a focused electron beam to scan the designed pattern and produce electron signal; an electron detection unit to detect the electronic signal; and a control unit converting the electron signal to a clock signal to determine the relative position of the electron beam column and the designed pattern, so as to adjust the displacement of the stage. A nanometer scale positioning method for a precise stage is provided, which can resolve the problem of mechanical drift of the stage when the stage is multi-axis positioning or rotating.
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BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to a fantasy sports league game in which participants act as “coaches” to form their own clubs or teams from among active league players and in which participant coaches are rewarded based upon the actual performance of the players on their teams in real life games as well as on the market value of their players.
II. Description of the Related Art
Fantasy sports league games are well known. Generally, in such games, participants select or “raft”, currently active real-life athletes to form fantasy teams. A participant's success or failure in the game corresponds to the performance of the players in real-life games. Such games are often referred to as “rotisserie leagues”. Owners of such fantasy teams compile won-lost records by competing head to head against each of the other teams in the league, the winner being determined by which team's players performed better the previous week.
Instantaneous communications technology allows people to participate in fantasy games in real time. For example, U.S. Pat. No. 5,018,736 to Pearson et al. describes an interactive contest that permits competition between remote participants. Participants register and can receive updates as to the progress of their teams by calling into a central location using the touch tone buttons on their telephones.
In the Pearson et al. patent, a team's performance is determined based upon the performance of the players on the participant's team roster in actual games. Comparison between teams is based upon team roster totals for given time periods. Team owners may make trades between the team roster and the contest roster. Throughout the duration of the contest, a voice interactive telephone menu is available to allow the participant to follow the progress of his or her team.
Some games have offered players the ability to participate in simulated gambling and stock market activities. For example, U.S. Pat. No. 6,007,427 to Wiener et al. describes a casino baseball game played on an electronic video gaming device. Player scores are determined based upon success in program-controlled “at bats”. U.S. Pat. No. 5,713,793 purports to combine elements of sports with that of the marketplace by providing a commodities options trading game in which the values of the simulated options are determined by a real-life sporting event. While using sports to define its market, this patent simply treats the sporting event as a commodity to be traded.
None of the patents discussed combine the fun of sports-based competition associated with a sports fantasy league with a test of the financial acumen necessary to maintain a team. Thus, the need exists for a game that combines the entertainment of fantasy sports with the excitement of participating in an economic venture.
SUMMARY OF THE INVENTION
In consideration of the above, the present invention is directed to a fantasy sports league game in which participants, acting as coaches and owners of fantasy teams made up of active players, can test their skill in player selection as well as in managing personnel and “virtual money” against other players. Thus, in the present invention the participant acts as both the coach and owner/general manager of his own team.
In accordance with one aspect of the present invention, there is provided a system for providing an interactive sports game to a plurality of participants each wishing to form a fantasy sports team made up of actual players, and each operating a participant terminal operable to act as a client on a network. The system comprises: a host controller, the host controller comprising a computer operable to act as a server on the network and to communicate with the participant terminals over the network; and data storage accessible to the host controller, the data storage storing information relating to performance of the players in actual games. The host controller is operable: (a) to solicit and accept from each participant an initial selection and purchase of players to form the participant's fantasy sports team, each participant purchasing the players using no more than a predetermined number of game value units initially allocated by the host controller, an initial value in game value units for each player being previously set by the host controller; and (b) responsive to a request of a participant, to access the data storage and report a status of the participant's fantasy team, the status including information as to performance and market, i.e., supply and demand, value of the players on the participant's team. The number of game value units associated with each player varies in correlation with demand of the participants for that player and a participant receives periodically a value-based reward correlated to the value of the players on his or her team. Preferably, a participant may invest any game value units unused in purchasing players in a fixed interest instrument or in a portfolio of stocks, the value of which tracks an existing stock market index.
In accordance with another aspect of the present invention, there is provided a method for providing an interactive sports game to a plurality of participants each wishing to form a fantasy sports team made up of actual players, and each operating a participant terminal operable to act as a client on a network, on a system comprising: a host controller, the host controller comprising a computer operable to act as a server on the network and to communicate with the participant terminals over the network; and data storage accessible to the host controller, the data storage storing information relating to performance of the players in actual games. The method comprising: (a) the host controller soliciting and accepting from each participant an initial selection and purchase of players to form the participant's fantasy sports team, each participant purchasing the players using no more than a predetermined number of game value units initially allocated by the host controller, an initial value in game value units for each player being previously set by the host controller; and (b) responsive to a request of a participant, accessing the data storage and reporting a status of the participant's fantasy team, the status including information as to performance and market value of the players on the participant's team. The number of game value units associated with each player varies in correlation with demand of the participants for that player and a participant receives periodically a value-based reward correlated to the value of the players on his or her team. Preferably, a participant may invest any game value units unused in purchasing players in a fixed interest instrument or in a portfolio of stocks, the value of which tracks an existing stock market index.
According to yet another aspect of the present invention, there is provided a computer-readable medium storing code for causing a processor-controlled system to perform a method for providing an interactive sports game to a plurality of participants each wishing to form a fantasy sports team made up of actual players, and each operating a participant terminal operable to act as a client on a network, the system comprising: a host controller, the host controller comprising a computer operable to act as a server on the network and to communicate with the participant terminals over the network; and data storage accessible to the host controller, the data storage storing information relating to performance of the players in actual games. The method comprises (a) the host controller soliciting and accepting from each participant an initial selection and purchase of players to form the participant's fantasy sports team, each participant purchasing the players using no more than a predetermined number of game value units initially allocated by the host controller, an initial value in game value units for each player being previously set by the host controller; and (b) responsive to a request of a participant, accessing the data storage and reporting a status of the participant's fantasy team, the status including information as to performance and market value of the players on the participant's team. The number of game value units associated with each player varies in correlation with demand of the participants for that player and a participant receives periodically a value-based reward correlated to the value of the players on his or her team. Preferably, a participant may invest any game value units unused in purchasing players in a fixed interest instrument or in a portfolio of stocks, the value of which tracks an existing stock market index.
According to still another aspect of the present invention, there is provided a method for a game participant, operating a client computer on a network, to play an interactive sports game run by an administrator operating a host computer on the network. The host computer: a) has access to a database of information relating to performance of players in actual games, and b) sets an initial value for each of the players based on predetermined criteria, the value for each player thereafter varying in accordance with demand for the player. The method comprising the steps of: purchasing players to form a team from among the players, the initial values of which have been set by the administrator, using no more than a predefined number of game value units allocated by the administrator for the purpose; and maintaining the team by selectively trading players, and by selectively investing or holding any game value units above the amount used to purchase players. The participant is eligible to win an award periodically on the basis of the value of his or her players, together with any additional game value units he or she may have accumulated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a block diagram showing an Internet-based hardware implementation of the fantasy sports game of the present invention;
FIG. 1B is a flow diagram illustrating the flow of operation from the main menu of the present invention depending upon which of several links is selected;
FIG. 2 illustrates an example home page in accordance with the present invention;
FIG. 3 illustrate an example sign up page in accordance with the present invention;
FIG. 4 illustrates an example page for player and team tactic selection in accordance with the present invention;
FIG. 5 illustrates the page shown in FIG. 4 after players have been selected;
FIG. 6 illustrates an example page on which a coach enters a pseudonym and password and selects insurance and investment options in accordance with the present invention;
FIG. 7 illustrates an example of a personal data entry page in accordance with the present invention;
FIG. 8 is an example of a page congratulating a newly-registered coach according to the present invention;
FIG. 9 is an example page requesting that a participating coach enter his or her name and password;
FIG. 10 is an example of a page showing a coach the progress of his or her fantasy sports team;
FIG. 11 is an example of a page showing a list of all coaches clubs registered to play the game of the present invention;
FIG. 12 is an example of a page showing a list of players eligible for selection by coaches in accordance with the present invention;
FIG. 13 is an example of page showing a list of real-life teams for a particular country's championship; and
FIG. 14, which consists of FIGS. 14A and 14B, is an example page showing results in a real-life sporting league for a particular day.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the interactive sports league game of the present invention, a participant acts as a coach of his or her own clubs or teams (the terms club and team will be used interchangeably throughout). The team or teams selected by the coach compete against teams assembled by other game participants. The players on the team must be “purchased” by the coach using an opening budget of game value units, the equivalent of virtual money, assigned by the game administrator for this purpose. The game administrator also assigns the initial values for players, which value fluctuates in accordance with supply and demand (i.e., the supply and demand of the coaches) for the player. The allow the greatest number of participants, the game preferably is Internet based, with the game administrator operating a server or host computer site on the Internet, allowing participants to communicate with the server via browser software on their client home computers.
An example of an Internet-based hardware implementation of the present invention is shown in FIG. 1 A. As shown in the figure, game participants operating client computers 1 communicate with the Web server computer 2 of the game administrator, preferably by visiting and interacting with the Web site located on the server. This process is typically initiated by the participant typing, into his or her browser, the Uniform Resource Locator (URL) of the server Web site. In response to receipt of this communication from a participant's browser, software operating in the server computer 2 controls the server to send the browser the game's home page form, preferably a Hypertext Mark-up Language (HTML) document, having a menu of options to be discussed below. An interactive session ensues, which will be described in detail below with reference to a preferred embodiment, allowing the participant to register as a coach, select a team, and monitor the progress of his or her team, among other things.
The server computer 2 is programmed to format data, accessed from local or remote databases or other sources of data, for presentation to the participant, preferably in the format discussed in detail below. The server computer 2 , although described herein in the singular, may actually comprise plural computers cooperating to perform the functions described herein.
The server computer programming can utilize any conventional Web data interface technique or techniques, such as Common Gateway Interface (CGI) protocol and associated applications (or “scripts”), or Java “servlets”, i.e., Java applications running on the Web server. It will be appreciated that the interactive forms to be discussed below, which present forms for entry of information by the participants, and which save the entered information to a database, may be implemented in any of several conventional ways, using known server applications. For example, in response to entry of the participant's name and password, the server can redirect the information to a CGI application that is called when the participant clicks, for example, a “submit” icon. Access to databases, both local and remote, containing for example game information or information as to current sports results, also may be implemented, for example, by other CGI or similar applications.
An illustrative example of a fantasy sports game in accordance with the present invention will next be described as implemented in relation to a particular sport, namely European championship league soccer. However, as will be apparent to one skilled in the art, the game of the present invention is in no way limited to the illustrated embodiment or implementation and may be applied to any team sport, such as Baseball, American Football, Basketball, etc.
In the illustrated implementation based on the European soccer championships, a participant becomes a “coach” by filling in the registration form, to be discussed in detail below, and by forming his or her ideal team. Each game participant shall be referred to hereafter as a “coach”.
Each coach may form one or two teams: a national team, by selecting players who are actually playing at the start of the season in one of five national soccer championships (France, England, Germany, Italy, Spain), and complying with the rules of that nationality; and an international team, by selecting players drawn randomly from these five championships.
The national team games are hereinafter referred to as “national championships”, and the international team games as “international championships”.
As will be described in further detail below, in a preferred embodiment of the soccer implementation, each team allows the coach at least two chances to win. The first consists of prizes offered periodically to the best teams based on a point ranking determined on the basis of the performance of the teams's players in actual games for the previous period. The second chance consists of money or prizes awarded at the end of the season to the best teams based on a value ranking for the team. The basis of the value ranking will be described below.
To form the team or teams, each coach must “buy” players. For that purpose, at the time his or her team is selected each player will be allocated units of account called Wams. For example, the units could be allocated as follows (the “opening capital”):
2200 Wams for the English championship
1700 Wams for the French championship
2100 Wams for the German championship
2200 Wams for the Italian championship
2000 Wams for the Spanish championship
2300 Wams for the international championship
An initial Wam value is fixed by the organizer for each player at the beginning of the season. Preferably, to most closely correspond to the player's actual market value, some objective criteria, such as the actual salary of the player, is used or taken into account in setting the initial value.
This initial value preferably is adjusted automatically throughout the season by the host computer according to the supply and demand of participant coaches for each player. A preferred method of adjusting the value for any player is to add a predetermined value, such as one Wam, for each time a new coach picks the player or trades for him. If, on the other hand, a new coach does not pick a player, a much smaller value unit will be subtracted from the player's value. An preferred example of such smaller valued unit to be subtracted would be 1/(the number of teams in the championship). For example, if there are 40 teams in the real championship, {fraction (1/40)} of a Wam would be subtracted from the player's value each time he is not chosen by a new coach.
The value of the team in Wams at any time shall consist of the sum of the individual values for each player, in addition to unused Wams. In selecting his or her team, the coach may not use more than the initial allocation of Wams. So that coaches can join the game at any time during the season and still have the same chance to win a prize, preferably the amount of Wam allocated for selecting the coach's players is increased throughout the season for new players.
Preferably, in the illustrated soccer embodiment, each team must be formed using one of the following six methods, as shown in Table I:
TABLE 1
Goal
Defense
Midfield
Forwards
Method 1:
1
5
3
2
Method 2:
1
4
4
2
Method 3:
1
4
3
3
Method 4:
1
4
2
4
Method 5:
1
3
4
3
Method 6:
1
3
5
2
The players are selected from a list proposed for each championship by the organizer and play in the positions they actually play in their own clubs.
If the coach selects a national team, he may select at random players with the nationality of any one of the countries whose clubs take part in the national championship of the country in question and belong to UEFA (Union of European Football Associations). Preferably, the coach may select only up to three players with the nationality of the country whose clubs take part in the national championship of the country in question and do not belong to UEFA.
Alternatively, the coach may choose to have his or her team or teams picked automatically by the game software on a random basis. If that option is chosen, preferably, the whole of the coach's Wam capital will be used up in this automatic selection.
For the duration of the season, which shall preferably be based on the actual soccer championship season calender, the coaches may transfer players by paying or receiving for each player bought or sold his value in Wams on the day of transfer. Preferably, this transfer may not include more than three players per team each week, the week being for this purpose preferably defined as the period between Monday evening at 6 o'clock GMT and the following Monday evening at 6 o'clock GMT.
At the time of each transfer a commission (determined in Wams), preferably of 10% of the sale price of the player, is deducted from the coach's amount of Wams. If he or she wishes, the coach may also take out insurance for one or more players on the team in order to cover the possibility that the player is injured and cannot play in more than two consecutive matches played by his/their club. For this purpose, the coach must pay a premium, preferably 10% of the value of the team on the date of taking the insurance for every team he or she wishes to insure. This insurance allows the coach to sell the player or players concerned at the Wan value at which he bought them, or if greater, at the player or players' value in Wams on the day before he/they were injured. The insurance may be used for a maximum of three players per team during any one season.
Throughout the season, the opening capital preferably shall be gradually: (a) reduced by the coach's expenses, that is to say the number of Wams corresponding to the value, at the date of the purchase, of the players purchased by him or her, either originally or at the time of a transfer, as well as transfer commissions and any insurance premiums; and (b) increased by coach income, that is to say the number of Wams corresponding to the value, at the date of sale, of players transferred at the time of transfer.
The coach may at no time spend more than the available balance of his or her Wam capital. The coach may decide to invest his or her available balance, either at a fixed rate of 4%, or in a virtual basket of shares that tracks the Eurostoxx 50 index.
As was discussed previously, each coach has at least two chances to win per team. Each of the coach's teams takes part in at least two competitions allowing him or her to gain a prize item each month and a large cash prize at the end of the season, the monthly prizes preferably being based on a point ranking and the large end-of-season prizes preferably being based on a value ranking, according to the terms described below. Optionally, a third prize may be offered using a combination of points and value ranking. For example, a points per value unit ranking could be the basis of a third prize.
At monthly, or other conveniently periodic, intervals, winners will be determined based on a point system. Each week each coach's national and/or international team scores points according to the actual performance of the players in real life soccer games. A certain number of points is defined according to the scale discussed below, and is awarded to each player on the team according to his actual performance during the week in the club to which he belongs, and the actual performance of his club. Only the performance of players and the club in matches of the actual national championship to which the club belongs is taken into consideration in point determination. The sum of points accumulated by each player on the coach's team or teams will give the number of points awarded to each team each week. An example of a preferred point system follows.
The scale of points:
a) Points won or lost according to the results of the players' club:
Win 30,
Loss 0,
Draw 10,
Goals scored against the club if the club wins or draws:
For each goal scored by a forward or midfielder: −2
For each goal scored by a defender: −3
Goals scored by the club if the club loses:
For each goal scored by a defender: −5
For each goal scored by another player: −3
A match without goals:
If a defender: 3 points
b) Points won or lost according to the actual participation of the player in the match:
For a whole match: 3
For part of a match: 2
Each time a player is brought on as a substitute: 1
Each time a player does not play in a match in which his club plays: −10
c) Points added or deducted according to the player's individual performance: Cards:
For each yellow card: −5
For each red card: −10
For each goal scored:
If a forward: 10
If a midfield: 15
If a defender or goal-keeper: 20
Deciding goal in the last 15 minutes: 10 (in addition to other points).
Due to the differences in championship calendars in European countries, some players may not play in a match during a week or may play two matches. The method of calculating points takes this factor into consideration as follows.
For the international team the number of points scored by the players on a coach's team is equal to a number of points scored by players on that team divided by the number of players on the team who belong to a club that actually played in a match in its international championship during the week in question. Where the same club plays in more than one match per week, the following will be added to the number of players: the number of matches over 1 in which the club played and the number of that club's players over 1, who belong to the coach's team.
Example: If during any week in the month of January a coach's international team includes a player who belongs to a club taking part in a German championship and the club has not played any matches in this championship, the number of points scored during the week in question shall be divided by 10.
If on the contrary the international team includes a Frenchman belonging to a club playing two matches in the week and the end results are fixed for example on 7 February, the number of points scored during the week in question shall be divided by 12; if two Frenchmen belonging to this club are part of the coach's international team, the number of points shall be divided by 13.
In the case of a national team, the number of points scored by a team equals the number of points scored by the team's players divided by 11.
Weekly points preferably shall be determined at a predetermined time and day of the week. At the end of the month the total of points accumulated during the weeks of that month will be calculated. It will then be decided for each national championship and for the international championship which ten teams have won the most points during the month in question. The coaches of those teams will win a prize. The list of these prizes preferably are published at the beginning of the following month on the main game home page screen.
If so many teams have an equal point total that the number of winners per championship would be more than ten, the ten winners may preferably be determined by declaring as winner the coach who spends the least Wams to make up his team; if there is another tie, then the winner is the coach who made the least number of transfers and, finally, if there is yet another tie, the winner is the coach with the team whose players have the lowest average age, using the day, month and year of birth to calculate that figure.
Winners at the end of the season are preferably determined based on value-ranking. At the end of the season a super prize will be offered in each of the six championships to the coach whose team has made the most progress in Wams (sum of the value in Wams for each player on the team). The comparison will be made between all the teams taking part in the same championship. The value ranking is totally independent of the point ranking discussed in the previous section. It should be noted that a player's value, after its initial setting by the game administrator, is determined on supply and demand of coaches, and is not affected by points earned by the player. Such market value will not strictly correlate with performance since other factors are involved in a player's popularity with coaches. For example, some players remain popular, and are thus desired by coaches, even though they are past their playing prime. Other players may be in demand based on their looks, or the fact that they have endorsements.
Where two or more teams are tied in terms of value ranking, the winner preferably will be the coach who at the start spent the least in Wams to make up his team; if there is another tie between one or more coaches, the winner will be the one who made the least number of transfers, and finally, if there is again a tie, the winner will be the coach with the team whose players have the lowest average age, using the day, month and year of birth to calculate that figure. The total sum that will be distributed by way of prizes between winners of the value ranking will be equal to one euro per coach taking part in the game (thus the more coaches there are who play, the greater the total sum will be). To determine this, each coach who fully and correctly filled out, validated and emailed in his registration form will be counted. This total sum preferably shall be shared among the winners in each of the six championships as follows:
xxx—the sum total allotted to the winners of the international championship shall be twice that allotted to each of the five national championships, each of which shall receive exactly the same amount.
Within each championship, the total sum allotted will be divided as follows:
3 shares to the coach with the highest Wam value;
2 shares to the coach with the second highest Wam value; and
1 share to the coach with the third highest Wam value.
For example:
If the Game has ten thousand coaches, the sum total to distribute is 10,000 euro. The first in each national championship shall win 714 euro, the second 476 euro and the third 238 euro. The first in the international championship shall win 1,430 euro, the second 950 euro and the third 480 euro.
If the Game has a hundred thousand coaches, the sum total to distribute is 100,000 euro. The first in each national championship shall win 7,140 euro, the second 4,760 euro and the third 2,380 euro. The first in the international championship shall win 14,300 euro, the second 9,500 euro and the third 4,800 euro.
If the Game has a million coaches, the sum total to distribute is 1,000,000 euro. The first in each national championship shall win 71,400 euro, the second 47,600 euro and the third 23,800 euro. The first in the international championship shall win 143,000 euro, the second 95,000 euro and the third 48,000 euro.
At any time, coaches may consult their team's position by obtaining the point value classification for each player, his Wam value and the change in percentage since he was purchased, the total value of the team in Wam and its change since the team was formed as well as the number of transfers made, in the manner discussed in detail below.
The coach may also obtain the value of the highest-ranked team, the average value for each of the teams as well as the points for each player and those won by the best team (as determined each week).
The registration process will now be described in accordance of a preferred embodiment of the soccer implementation. Of course, the invention is not limited to the preferred embodiment.
When a participant uses his or her browser to visit the Web site of the game organizer, a game home page appears. The home page offers the participant several options, implemented preferably as hypertext links, as to how to proceed. The options are shown in the flowchart of FIG. 1 B.
As shown in that figure, in response to the participant visiting the game web site, by for example entering the web site's URL into his or her browser, a home page of the game Web site is presented to the participant. The home page of the game Web site presents a visiting participant, or potential participant, with a menu of several links, at step S 100 . An example of a home page in accordance with a preferred embodiment of the present invention is shown in FIG. 2 . Depending upon which link is selected, a host computer program decides, at step S 102 , which screens, preferably HTML pages or the like, to display to the participant next.
If the participant clicks the “sign up” link, flow proceeds to step S 104 , at which Web server software running on the host computer of the game Web site causes HTML pages such as those shown in FIGS. 3-8 to be transmitted, in the order and manner discussed in detail below with reference to those figures, to the participant's browser. If the participant clicks the “my account” link, flow proceeds to step S 106 , at which software running on the server computer causes the screens shown in FIGS. 9 and 10 to be transmitted, in the order and manner discussed in detail below with reference to those figures, to the participant's browser.
If the link “Table” is selected, flow proceeds to step S 108 , at which point the Web server will transmit an HTML page having a list of already registered fantasy clubs to be displayed, for example in the format shown in FIG. 11, to be discussed in detail below.
If the link “Rules” is selected, the Web server will transmit, at step S 110 , an HTML page having a copy of the rules of the game in accordance with the present invention.
If the link “Players” is selected, the Web server will transmit, at step S 112 , and HTML page having a listing of information about players eligible for selection in the fantasy sports game. An example of a screen showing such a listing is shown in FIG. 12, which will be discussed in detail below.
If the link “Clubs” is selected, the Web server will transmit, at step S 114 , an HTML page with information relating to actual real-life soccer clubs on which the players eligible for selection in the game play. An example of a screen showing such information is shown in FIG. 13, which will be discussed in detail below.
If the link “Results” is selected, the Web server will transmit, at step S 116 , an HTML page having results of matches in real-life games of actual clubs. An example of a screen showing such information is shown in FIG. 14, which will be discussed in detail below.
If the link “Schedule” is selected, the Web server transmit, at step S 118 , an HTML page (not shown) listing the schedule for the current season of the real life teams in the championship.
The individual screens, caused by transmission of the respective Web pages, presented to the participant to implement the functions shown in the flowchart will now be discussed individually.
A visitor to the site wishing to register as a new coach must first select, on the home page, the link “sign up”. Clicking on this link causes the server to send to the visitor's browser a page consisting of a sign up form. An example of such a sign up form is shown in FIG. 3 . As can be seen from the figure, the form informs the participant of the option to form one or two teams. Radio buttons 100 are provided for selecting the national team, each button having a country flag associated therewith. The participant may select one of these buttons by clicking it with a mouse or other similar cursor movement and selection device. Radio buttons 102 are provided to allow the participant to indicate whether he or she wishes additionally to form an international team.
Entry area 104 is provided for the participant to enter a club name. To increase the enjoyment of the game, the coach also is encouraged to create a team shirt by selecting colors from radio buttons 106 . As the buttons are selected, in response to clicking of “Display” button 107 , shirt icon 108 changes colors in real time to show the coach what his or her team shirt will look like.
Once the coach is satisfied with the selected name and other entered information, he or she clicks the submit icon 110 which registers the information with the organizer's server computer.
In response to receipt of the team information entered in the form of FIG. 3, the server presents the coach with another form (HTML document) requesting formation of the national team. An example of such a form is shown in FIG. 4 . As shown in the figure, the coach is informed at the top of the form that he or she has initial capital of 3200 Wam and can spend up to 2900 Wam to buy players. The coach also has the option to have the game administrator select the team automatically, in which case the coach clicks automatic selection button 200 and all 2900 Wam will be used up and the players will be selected at random.
The default team tactic (i.e., method of grouping of position players, as in Table I above) is shown in the figure in team tactic selection tool 202 . This tool also functions as a drop down menu to allow the coach modify the default setting to select any one of the methods shown in Table I above to form the team. Depending on the tactic selected, the appropriate number of players from each position may be selected. If manual player selection is chosen, the coach clicks at the hypertext link under each position and is presented with a list of all players at that position in the selected national championship. For example, the list of goalkeepers is listed at the bottom of the FIG. 4 . Similar lists are presented as the coach selects the link for each position to fill his or her team.
As the players are selected in the manual mode, the team value tally 208 is incremented. The coach may not exceed the upper limit, in the example 2900, when selecting his or her team players. FIG. 5 shows the screen presented to the coach after the team has been selected. Note that even when automatic selection has been effected, the coach can modify any player selection by clicking on the modify link associated with the player, as long as the spending constraints are not exceeded.
Once the team has been selected, the coach is presented with a form requesting that he or she select a manager surname, or pseudonym, and a password. This manager name and password will be requested by the server whenever the coach wishes to check on the progress of his or her team after the registration process is complete. The coach also is asked at this time whether he or she wishes to purchase insurance, in case one or more of the coach's players becomes injured and cannot play in subsequent matches. The insurance option can be selected by clicking the appropriate one of radio buttons 304 . As mentioned above, the premium for the insurance is ten percent of the current value of the team. The coach is also presented, by means of radio buttons 305 , with the option of investing his or her available balance of capital in a portfolio of stocks, tracking the Eurostoxx 50, at a fixed rate bond, in the example, at 4%, or to have no investment.
Note that in the illustrated example, the coach has not selected an international team. Had such a team been selected, the same information and options would have been presented in a second column in FIG. 6 . FIG. 7 shows an example of a form that may be downloaded to the coach's browser to request entry of personal information about the coach. If the coach wishes to be eligible for prizes, he or she must enter valid personal data. Participants who enter false data can still keep track of the progress of their team, but will not be eligible for prizes.
Upon successful registration, the coach is presented with a form such as that shown in FIG. 8, encouraging the coach to enjoy playing the game.
After a participant has registered as a coach, he or she, on subsequent visits to the organizer's Web site, can check on the progress of his or her team. As shown in FIG. 2, a registered coach, instead of selecting “sign up” can select “my account”. The coach selects this as a hyperlink on the game home page, and in response the server presents the coach with a form such as the one shown in FIG. 9 . In FIG. 9, the coach is presented with manager name entry space 500 and password entry space 501 . Once this information has been entered, it is sent to the server by the coach clicking the submit button 502 .
In response to the coach's entry of the manager name and password, the server transmits to the coach's computer a form indicating the coach's team's progress. An example of such a form is shown in FIG. 10 . As shown in the figure, in addition to identifying information as to the coach's team, FIG. 10 presents the coach with four basic information fields, which are described as follows.
Team data field 600 consists of: player column 601 , which is a list of the players currently on the coach's team and their position; purchased value column 602 , which lists the value at which the players were purchased; current value column 603 , which lists each player's current value, as determined by the market for the player among the coaches playing the game; progress column 604 , which lists the percentage of change, if any, of value of each player; points column 605 , which lists the points accumulated by each player in accordance with the point scoring formula outlined above; date of purchase column 606 indicates the date the player was purchased; and transfer link column 607 , presents the coach with links allowing him or her to initiate a transfer of any player in accordance with the rules set forth above.
Value data field 610 lists the current team value in Wams, the purchased value, the placement and the total value. Also displayed is the progress in percent. Value ranking field 621 displays which position, among all participant coaches, is occupied by the coach in terms of team value. The points ranking field displays the coach's current point position in relation to all other coaches.
Another link available for selection on the main menu is labelled “Table”. The clicking of this link transmits to the coach's browser a menu listing the fantasy clubs participating in the game. An example of such a menu is shown in FIG. 11 . As shown in the figure, the exact information to be displayed can be determined by use of drop down menus 701 and 702 . Drop down menu 701 allows the coach to see a list of clubs in any of the country championships as well as the international championship. Drop down menu 702 allows the list to be sorted either by value or by points. In the example shown in the figure, the list is of clubs in the England championship sorted by current value. A search window 708 is provided to allow the coach to search for a particular club.
The main menu shown in FIG. 2 also provides a link entitled Rules. Clicking this link causes a document comprising the rules of the game to be transmitted to the coach's browser. Clicking the link “Players” causes a list of all athletes eligible to be on any team in the fantasy league to be transmitted to the coach's browser for display. An example of such a list is shown in FIG. 12 . In that figure, all players are made available for viewing, although on any one screen only a certain number of players will fit. Thus, links are made available to view succeeding portions of the list, using techniques well known in the art, such as next buttons or the like.
Drop down menu 800 allows the coach to determine the players from which championship will be displayed. The coach can choose from among the international championship and the country championships mentioned above. Drop down menu 801 allows the player to limit which positions are displayed. In the example, “all” has been selected, so all players from the England championship will be displayed. Other options include showing only goalkeepers, defenders, midfielders or strikers. Drop down menu 802 allows the list to be sorted on the basis of alphabetical order, current value, progression, points, and demand, respectively. Player information is preferably set forth in columns such as columns 805 , 806 , 807 , 808 , 809 , 810 , 811 , 812 , and 813 , corresponding to the player's name, club, position, current value, highest value, lowest value, progression, points and demand, respectively. To search for a specific player, the coach can enter the player's name in search window 814 and click “OK”.
The main menu also provides a link for the coach to view a list of clubs. Clicking on the link will cause the server to direct the coach's browser to a menu displaying a list of actual real-life soccer clubs in the country championships listed above. An example of such a menu is shown in FIG. 13 . As shown in the figure, drop down menu 900 allows the coach to select which country's clubs will be listed. Drop down menu 901 allows the teams to be sorted by alphabetic order, average value or by total value. Columns 902 , 903 and 904 display the club name, average value for each club and total value for each club, respectively.
Another link provided on the main menu is “results”. When the coach clicks on this link, he or she is directed to a page listing results of that day's actual games of the real life teams in a particular championship. FIG. 14 is an example of such a page. In the figure, drop down menu 1001 allows the coach to select for which championship he or she wishes to see results. Drop down menu 1002 allows the coach to choose for which day he or she wishes to see results. Below those menus, in area 1003 , results for the selected day are displayed. In area 1004 , the real-life teams are listed in points order. In area 1005 , the top scoring players in the selected championship are listed, with associated information, such as their teams, goals, value and demand.
The above-described embodiment allows coaches to follow the progress of their team or teams, both from the viewpoint of athletic performance, which is reflected by points, as well as the value of the investment of fantasy money used to form the team. In view of this combination of activities, a coach can experience the feeling not only of coaching a team, but of being a team owner and general manager. This is further heightened by the participant coach's ability to trade players, purchase insurance and invest surplus funds.
As would be apparent to one skilled in the art, the above-described fantasy game can just as easily be applied to sports other than soccer. For example, baseball players, even more so than soccer players, have associated performance-based statistical data. All of the information windows discussed above could be used to show baseball players, their teams, their values and points derived from performance characteristics, such as batting average, number of runs batted in or home runs. Pitchers can easily be evaluated in terms of wins, earned run average, strikeouts, walks (control) and other statistical criteria. So, in a baseball implementation, a coach would select position players as well as pitchers, and preferably several bench players. In such implementation, points-based prizes can be based upon the performance of the baseball players' performance for the preceding week, for example. At the end of the season, the collective value of the players on the coach's roster, taking into account market fluctuations in player value and investment, just as in the soccer implementation, can be used to award a grand prize.
Further, the present invention can easily be implemented using other league sports such as Ice Hockey or American Football, as will be appreciated by those skilled in the art.
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A system for providing an interactive sports game to a plurality of participants wherein each participant wishes to form a fantasy sports team made up of actual players. The system is operable: (a) to solicit and accept from each participant an initial selection and purchase of players to form the participant's fantasy sports team, each participant purchasing the players using no more than a predetermined number of game value units initially allocated by a host controller; and (b) responsive to a request of a participant, to access the data storage and report a status of the participant's fantasy team, the status including information as to the performance and market value of the players on the participant's team. The number of game value units associated with each player varies in correlation with the demand of the participants for that player and a participant receives periodically a value-based reward correlated to the value and/or performance of the players on a participant's team.
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