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This invention was made with government support under Contract Number: FA9302-10-M-0011 awarded by The United States of America as represented by the Department of the Interior, Washington, DC. The government has certain rights in the invention.
TECHNICAL FIELD
The invention relates to a method for denying soaring and migratory birds access to critical areas of airports and aircrafts and paths of taking off and landing aircrafts. More particularly, the inventions provides a method of eliminating a potential formation of thermals or up-draughts essential for lifting soaring and migratory birds, thereby avoiding conflicts between taking off and landing aircrafts and soaring or migratory birds.
BACKGROUND
Bird strikes happen most often during takeoff or landing, or during low altitude flight of aircrafts. The majority of bird collisions occur near or on airports (90%, according to the International Civil Aviation Organization (ICAO)) during takeoff, landing and associated phases. According to the FAA Wildlife Hazard Management Manual (2005), less than 8% of strikes occur above 900 m (2,953 ft) and 61% occur at less than 30 m (100 ft). The point of impact is usually any forward-facing edge of the vehicle such as a wing leading edge, nose cone, jet engine cowling or engine inlet. For example, turkey vultures and red-tailed hawks account for the majority and more costly of damaging raptor strikes to USAF aircrafts, which amount to 31% and 32%, respectively. As of Jan. 1, 2008, turkey vultures were responsible for 798 bird strikes costing about 52 million dollars while the red-tailed hawks were responsible for 814 strikes with about 14.6 million dollars in damages. Both turkey vultures and red-tailed hawks showed a marked increase in the number of bird strikes during the summer. This was due to the relationship between thermal activity and strike rate for these two species. Both forage by soaring on thermals, without which they are unlikely to reach the height required to bring them into conflict with aircraft. Thermals are formed on dark earth, black tops, roadways, towns, urban areas plowed fields and exhaust gas from power plants in the presence of cumulus clouds. On the other hand, sun reflective surfaces, marshes, and white coated surfaces do not support thermals. The most pronounced damage was caused by the American white pelican reaching about 257.65 million dollars in spite of their low number of strikes. Other thermal soaring birds responsible for the top 50 USAF wildlife strikes include buzzards, eagles, kites, gulls, herons, pelicans and terns.
The typical lift-off speed for an F-15 fighter plane is 150 knots. A Boeing 747, for example, spends longer time in critical path. The aircraft acceleration during takeoff and landing hinders any birds' reaction to avoid collision. Reaction time of birds relative to the motion of the aircrafts is very important for survival of the birds and the avoidance of damage to the aircraft. Such reaction time for soaring birds will be much longer compared to free flying birds.
Accordingly, there is a need to eliminate soaring and migratory birds' conflicts with aircrafts. There is also a need to eliminate the formation of atmospheric thermal currents or thermals in the immediate vicinity of the airports and airfields proper and along the paths of taking off and landing of aircrafts. In addition, there is a need to provide high albedo surfaces in the airport including surfaces of the buildings, runways, roads and the surrounding terrain while preserving the aesthetics of the surfaces. Furthermore, there is a need to conserve/protect migratory birds and soaring birds by providing them with sanctuaries and/or habitat away from airways.
SUMMARY
The invention provides a method for creating a thermals-free zone that may include the expanse of airports and airfields proper and at the same time denying soaring and migratory birds' access to such zone.
According to one embodiment consistent with the claimed invention, a method is provided for denying soaring and migratory birds access to critical areas of airports and airfields and paths of taking off and landing aircrafts, comprising eliminating a potential formation of thermals or up-draughts essential for lifting soaring and migratory birds and dividing the critical areas of airports and airfields and paths of taking off and landing aircrafts into a plurality of zones.
In one aspect of the invention, the plurality of zones include an airport zone 1 or a thermals-free zone 1 that includes an airside area and a landside area of the airports and airfields and the paths of taking off and landing aircrafts; an unrestricted zone 3 of open and public spaces that are not under the control of operators of the airports and airfields; an exclusion zone 2 that separates the thermals-free zone 1 from the unrestricted zone 3 ; a green area zone 4 that provides protection, sanctuary and abundant food and water supply for the soaring and migratory birds; a bird sanctuary zone 5 for conservation and creation of a habitat for the soaring and migratory birds; and a water body zone 6 that is immune to the potential formation of thermals surrounding the thermals-free zone 1 from the unrestricted zone 3 .
Still other aspects, features, and advantages of the present invention are readily apparent from the following detailed description, by illustrating a number of exemplary embodiments and implementations, including the best mode contemplated for carrying out the present invention. The present invention is also capable of other and different embodiments, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of an overall layout of a sample airport that include an airport zone 1 or a thermals-free zone 1 , an exclusion zone 2 and an unrestricted zone 3 (not drawn to scale);
FIG. 2 shows a cross-section of the ground of the airside and landside areas of thermals-free zone 1 , buildings, exclusion zone 2 and unrestricted zone 3 of the sample airport shown in FIG. 1 ;
FIG. 3 illustrates the use of a gravel easement 114 on each side of the pavement of the airside and landside of thermals-free zone 1 ;
FIG. 4 illustrates the active cooling of each of the gravel easements 114 as depicted in FIG. 3 ;
FIG. 5 illustrates the active cooling of the pavement of the airside of the thermals-free zone 1 using a plurality of water pipes 162 ;
FIG. 6 illustrates the construction of a bird sanctuary zone 5 ; and
FIG. 7 illustrates the construction of a green zone 4 for soaring and migratory birds.
DETAILED DESCRIPTION
The degree of solar heating of the ground depends on many factors, e.g. solar insolation in the area; color, mass and condition of the exposed surface; specific heat and thermal conductivity of the substance of the exposed surface, and location of the substance on the surface of the earth in relation to other nearby objects.
Surface color, as known in the law of physics, plays a very important role in the phenomena of radiant heat absorption and emission. Therefore, a white body surface can, under similar conditions, emit a lesser amount of sensible heat than a black body per unit surface.
In consistent with the features of the invention, it is desirable to have a cold body surface surrounded by a warmer body surface to mitigate the conditions that lead to the formation of thermal currents. By doing so, it allows for an exclusion distance (exclusion zone 2 ) that would avoid stray birds and, at the same time, accommodate planes that overshoot their planned flight path. Under these conditions, cool air from the cold area will not only continually flow over the hot area but will also be raised in temperature, expand, decrease in specific gravity, and eventually rise up. Based on the above, it becomes possible to provide migratory bird species and other birds with a non-restricted protected area (unrestricted zone 3 ) or a sanctuary (bird sanctuary zone 5 ) at a distance far enough from flight paths so that they can roost, nest, feed and forge freely while avoiding conflicts with arriving and departing aircrafts.
In the airport proper (thermals-free zone 1 ), the whole airside areas (including all areas accessible to aircrafts, e.g., runways, taxiways, ramps and tank farms) may be kept at a temperature close to that of the air temperature of a cold body or white body using passive means, e.g., high-albedo surface-coating and/or reflective materials. In areas where in the summer heat is excessive and characterized by higher insolation over extended periods, active means may be used, e.g., application of cooling water. Exposed surfaces of terminal buildings, hangers, cargo storages, service buildings and tank farms, etc., may be coated with white coating and/or reflective materials. Landside areas including parking lots, public transportation train stations (if any), and access roads may have at least off-white colors on their surfaces.
U.S. Pat. No. 7,198,427 to Carr et al. discloses a safety system for airports and airfields that includes (1) an aesthetically pleasing artificial turf that retards birds and other animals and (2) a sub-surface that supports the weight of an aircraft, enhances water drainage and enables the accessibility of airport vehicles to all parts of runway or taxiway, and methods for installing the safety system. However, the green color of the artificial turf according to Carr et al. supports thermal formations that attract gatherings of soaring birds having a free-lift to collide with planes at relatively low altitude.
In fact, work by others promoted the formation of artificial thermals in favor of facilitating the flights of sailplanes and gliders. For example, in U.S. Pat. No. 2,268,320, Brandt describes the production of atmospheric or thermal air currents in the immediate vicinity of the airport by heating large volumes of air either by solar or artificial means to provide up-draughts that are essential to soaring or gliding flights. In addition, U.S. Pat. No. 2,371,629 to Lee discloses a means for forming an artificial thermal or ascending warm air current for sail-plane soaring that can be actuated by solar radiation.
The method, in consistent with the features of the claimed invention, may provide an extension of the thermals-free zone 1 around the expanse of airports and airfields, which, in turn, allows ample distances for aircraft flight paths during aircraft take-offs and landings, without creating conflicts between any size aircrafts and soaring and migratory birds. It may also secure the thermals-free zone 1 , particularly on the airsides of airports or airfields by active cooling the surfaces of the pavements of the airsides. It may also provide an exclusion area 2 of sufficient width around the thermals-free zone 1 for separating the zone from birds' habitats, sanctuaries and roosting areas, thereby preventing possible collision between stray soaring birds and aircrafts that divert from their flight paths. It may further provide a safe protected area for birds to roost, nest, feed and soar freely away from air traffic.
Hereinafter, the invention will be described more specifically by way of examples. It is to be noted, however, the invention is by no means limited to these examples.
EXAMPLES
As described in FIG. 1 , there are a plurality of zones that can be contemplated in accordance with the features of the claimed invention. The plurality of zones include an airport area 1 or a thermals-free zone 1 , an unrestricted zone 3 , an exclusion zone 2 that separates thermals-free zone 1 from unrestricted zone 3 ; a green zone 4 that is located on the unrestricted zone 3 and includes grass, shrubs, trees, etc.; a bird sanctuary zone 5 that serves as a protected area for birds to nest, rest, roost and soar; a water body zone 6 such as a lake, man-made pond or alike along the runway may protect the aircrafts during takeoff from collisions with soaring birds at a relatively higher altitude. Although the sketch in FIG. 1 applies to one runway in a small airport, the principle may be applied to multi-runway airports.
As shown in FIG. 2 , the exposed surfaces and sidings 112 of the control tower, terminal buildings 11 , tarmacs 13 , cargo 14 , hangars and other structures, such as service buildings, may be made of reflective materials. The roofs 111 may be coated with special coating material, such as a mixture of various silica and ceramic beads immersed in a high quality latex base with acrylic binders; e.g., TEMP-COATยฎ (manufactured by SPAN-WORLD Distribution, LLC) and THERMAL-COATโข (manufactured by Innovative Coating Solution, Inc.) and the like or better.
As illustrated in FIG. 2 , the creation of cold or white body requires the use of high-albedo pavements constructed from white cement concrete 161 . Accordingly, the airside areas of the airport area 1 or thermals-free zone 1 , including taxiways 16 , runways 17 , tarmacs 13 and the ground around tank farms 15 may be paved with white cement concrete 161 directly over the earth surface 7 and may be surfaced with a white coating, e.g., white cement coating.
Also described in FIG. 2 , the landside areas of the airport area 1 or thermals-free zone 1 , including terminal 11 , parking lots 12 , cargo 14 , public transportation train stations (if any), and access roads may be paved with an asphalt layer 101 with an upper layer 102 made of light-colored, non-heat absorptive material that acts as a thermal insulator. The material of upper layer 102 needs to be water-insoluble so that it will remain intact during wet seasons. Examples of the material for upper layer 102 may include aggregates (e.g., granite, limestone or water insoluble salts, such as chalk, crystallized gypsum, magnesium oxide, etc.). Additionally, the pavement may be surfaced with a top-coat 103 made up of mixed chippings of sand and oyster shells, etc., as shown in FIG. 2 .
An artificial turf may also be constructed in the exclusion zone 2 , in accordance with the disclosure of U.S. Pat. No. 7,198,427 to Carr et al., with the selection of a lighter color artificial turf instead. This is due to the ability of the artificial turf to discourage birds' presence. However, it is well-known fact that plowed fields and well groomed grass are good source of thermals. Accordingly, one embodiment of the invention, as shown in FIG. 2 , is the use of an off-white color for top layer 201 in the exclusion zone 2 . The top layer 201 is over the asphalt 101 and may be constructed from gravel mixed chippings of sand and oyster shells.
In FIG. 3 , the white concrete pavement 161 of the airside of the airport area 1 or thermals-free zone 1 , may have a first and a second gravel easements 114 on each side of the white concrete pavement 161 . Each of the gravel easements 114 may extend to each side part of the layered pavement of the landside to replace the upper layer 102 and top-coat 103 .
The first and second gravel easements 114 , may be further artificially cooled by formation of a thin water film 115 . The thin water film 115 may be maintained during times of high insolation through a timed spray system 116 , as shown in FIG. 4 . The thin water film 115 can provide evaporative cooling to the gravel easement 114 , which has a porous like structure.
As illustrated in FIG. 5 , the white concrete pavement 161 of the airside of the airport area 1 or thermals-free zone 1 is actively cooled by means of a plurality of water pipes 162 that are embedded in the white concrete pavement 161 . The plurality of water pipes 162 may be made of PVC or any other durable plastic material. Cooling water may be circulated through the plurality of water pipes 162 with the aid of a pumping station 163 to maintain water temperature and flow sufficient to provide a thermal equilibrium between the surface of the white concrete pavement 161 and ambient air. The benefit gained from this arrangement is that the plurality of water pipes 162 may be utilized for transporting warm water during winter season in cold regions to prevent the surface of the white concrete pavement 161 from freezing.
The layout and construction of the bird sanctuary zone 5 may enhance the formation of thermals to attract soaring birds, which sense the presence of thermals through the emitted infrared and infrasonic waves, as well as the associated humidity. The bird protected areas or bird sanctuary zone 5 may be constructed according to the disclosure of either U.S. Pat. No. 2,268,320 to Brandt or U.S. Pat. No. 2,371,629 to Lee or any of one of similar designs.
An exemplary bird sanctuary zone 5 , according to the features of the invention, is shown in FIG. 6 . One side of the bird sanctuary zone 5 may include a water body zone 6 and a top layer 201 of the exclusion zone 2 . The bird sanctuary zone 5 may include a dark-colored or black body 51 and a reflecting light colored or white surface 52 , which rests on the earth surface 7 and extends underneath the dark-colored or black body 51 . The dark-colored or black body 51 is formed from a porous heat absorptive material such as peat moss. The light colored or white surface 52 may be formed from sandy soil topped with oyster shells or similar heat reflective material of albedo significantly higher than that of the dark-colored or black body 51 .
Through solar heating, the dark-colored or black body 51 absorbs heat and transfers the radiant heat to sensible heat, which, in turn, heats the air in contact with it by conduction means. At the same time, the light colored or white surface 52 reflect the solar radiant heat causing the temperature of the air in contact with the dark-colored or black body 51 to be raised, expanded and then risen to form a steady up-draught of air, as shown in FIG. 6 .
Similarly, the green area zone 4 can be constructed from natural grass and shrubs to provide a habitat for birds where they can nest, feed and breed. Furthered by natural grass, birds and other animals, including gulls, waterfowl, raptors such as hawks and other species flock to airfields to eat, drink and reproduce. By doing so, they pose a potentially dangerous safety problem for departing and arriving aircrafts. Birds eat insects and grubs, which live in natural grass up to six inches (15 cm) below the soil surface. Birds also eat rodents that feed on the insects. Standing water, particularly after fresh rains, attracts many species of birds, including waterfowl. Large birds, such as ducks or geese, also create dangerous conditions for aircrafts (classified herein as foreign object damage (FOD)). Natural grass further provides material and cover for birds to nest and breed.
FIG. 7 shows the construction of the green zone 4 . On one side of the bird sanctuary zone 5 are the water body 6 and the top layer 201 of the exclusion zone 2 . The green zone 4 includes a tall grass area 41 , which is in direct contact with the earth surface 7 and a reflecting light colored or white surface 42 that also rests on the earth surface 7 . The tall grass area 41 may include natural grass, shrubs and may also contain drainage water or narrow streams of water. The white surface 42 may be formed from sandy soil topped with oyster shells or similar heat reflective material of albedo that is significantly higher than that of the tall grass area 41 . This arrangement is conducive to the formation of up-draught particularly in the presence of cumulus clouds 8 .
The invention disclosed herein may also be applied to military airfields, as well as civilian airports of any type or size.
In addition to attracting soaring birds (e.g., herring gull; great blue heron; ring-billed gull; Swainson's hawk; sharp-shinned hawk; laughing gull; Australian pelican; Franklin's gull; Caspian tern; common black-headed gull; other gulls, terns; hawks; eagles, kites (e.g. Mississippi kite and etc.)) to protected areas where thermals are likely to be formed, other factors such as the availability of food, water, safe locations for nests and rest may also attract other birds beside those mentioned above. Other birds may include the barn swallow/swallow; dark-eyed junco; mallard; American mourning dove; snow goose; horned lark; common/great northern loon/diver; killdeer; rock dove/pigeon; perching birds; common Turkey; lesser scaup; common starling; eastern meadow lark; American robin; double-crested cormorant; American cliff swallow; American kestrel; lark bunting; northern pintail/pintail; gadwall; common buzzard/buzzard; western meadowlark; chimney swift; yellow-rumped warbler; common wood-pigeon; kittiwakes; Mexican/Do.-Str. stone-curlew/thick-knee; sparrows; buntings; and finches. All of these bird species were responsible for the top 50 collisions with USAF aircrafts by First of January 2008. Hence, it is important to attract them away from the paths of aircrafts during taking off or landing. This is in addition to denying them access to critical areas of airports and aircrafts and paths of taking off and landing aircrafts.
Although a limited number of exemplary embodiments of the claimed inventions have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the inventions. Therefore, the scope of the inventions is to be determined solely by the following claims and their equivalents.
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A method is provided for mitigation of aircraft bird strikes through the provision of conditions on the ground that totally prevents the formation of atmospheric thermals in the proximity of airports and airfields, whereby conflicts between soaring and migratory birds and aircrafts may be avoided. This is accomplished by modification of the topography of the field into a plurality of zones, as described herein and through construction of high albedo pavements, roads, artificial turfs and cool terrains.
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[0001] This application is a divisional application claiming priority of Ser. No. 10/281,463, filed on Oct. 25, 2002; which is a divisional of U.S. Pat. No. 6,492,600, issued Dec. 10, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to interconnect structures, and more specifically relates to a receptor pad for use in a chip carrier package.
[0004] 2. Prior Art
[0005] Forming electrical connections between components remains an ongoing challenge in the electronics industry. As sizes decrease, more precision and smaller interconnections are required when attaching components to circuit boards, planar surfaces, substrates, and the like (collectively referred to herein as โlanding areasโ). While soldering techniques are widely available to connect components, the ability to provide landing areas with small and reliable receptor pads becomes increasingly difficult.
[0006] One particular application that utilizes high density interconnections involves integrated circuit (IC) chip packaging. An IC chip package comprises a relatively small IC device encapsulated in a larger package, which is more suitable for use in the industry. The โlargerโ IC chip package includes external connectors (e.g., a ball grid array) suitable for electrical communication with a traditional circuit board. Conversely, the smaller IC device, which comprises much smaller connectors, resides within the IC chip package on a landing area or laminate. Thus, the IC chip package must provide a relatively small landing area as well as a system for internally routing signals between external package connectors and internal IC device connectors.
[0007] In order to achieve this redirection of signals, a landing area comprised of a circuitized substrate or laminate is provided having a set of internal (high density) receptor pads. Circuit lines within the substrate route the signals from external connectors, which are in communication with external devices, to the receptor pads on a landing area, which connect with the IC device. Connection between the landing area and IC device is generally achieved by soldering. Solder techniques are well known in the art and examples are found in U.S. Pat. No. 5,597,469 issued on Jan. 28, 1997 to Caret' et al., and assigned to International Business Machines.
[0008] As noted, given the trend towards smaller IC devices, the circuitized substrate must provide a high number of receptor pads in a very small surface area. This is becoming more difficult to achieve with present design techniques. Specifically, because solder cannot wet down onto non-metal and/or organic materials, receptor pads must be designed with an adequate metal surface to ensure attachment. If such a surface is not provided, solder often fails to properly wet the pads and becomes inadvertently removed from the pad during subsequent reflow and wash processes. The most common pad structure to ensure adequate metal surface comprises a โdog boneโ structure that utilizes a flat pad attached to an adjacent via. Unfortunately, these structures take up a lot of surface area.
[0009] Thus, a need exists to provide a receptor pad that can reliably receive solder without requiring an extensive amount of surface area. All of the aforementioned references are hereby incorporated by reference.
SUMMARY OF THE INVENTION
[0010] The present invention provides a method for forming a receptor pad on a laminate, comprising the steps of: providing a circuitized substrate that includes a surface having a conductive element; mounting an external dielectric layer (EDL) on the surface; forming an opening in the EDL to expose the conductive element and create a microvia; treating an interior side wall surface of the microvia to promote copper adhesion; and electroplating the microvia with copper.
[0011] Once the microvia is electroplated, a resist process is used to define and finalize the receptor pad. Thereafter, a wet solder paste may be deposited on the receptor pads followed by a reflowing and washing step to create a reliable solder bump.
[0012] The invention also comprises a laminate having a receptor pad formed thereon, comprising: a circuitized substrate having a conductive element on a surface; an EDL mounted on the circuitized substrate, the EDL having an opening positioned above the conductive element to form a microvia; and an electroplated layer deposited within the microvia.
[0013] It is therefore an advantage of the present invention to provide a microvia structure that can be used as a receptor pad and directly receive a solder deposit.
[0014] It is therefore a further advantage of the present invention to provide higher density surface mounting technology by eliminating the need for dog bones and the like.
[0015] It is therefore a further advantage of the present invention to provide a microvia that allows solder to reliably wet thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The purpose of the foregoing and other aspects and advantages will be better understood from the following detailed description of the invention with reference to the drawings, in which:
[0017] FIG. 1 depicts a cross-section of a IC chip package in accordance with a preferred embodiment of the present invention;
[0018] FIG. 2 depicts a cross-section of a laminate in accordance with a preferred embodiment of the present invention;
[0019] FIG. 3 depicts a cross-section of a receptor pad in accordance with a preferred embodiment of the present invention; and
[0020] FIG. 4 depicts a flow chart of a method of fabricating a receptor pad in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring to figures, FIG. 1 depicts a cross-section of a integrated circuit chip package 10 .
[0022] The integrated circuit chip package 10 includes a chip 12 , a laminate 14 , connections 16 that interconnect the laminate 14 with the chip 12 , a cover plate 20 , a stiffener 24 , adhesives 26 and 28 , an encapsulation material 22 , and a ball grid array (BGA) structure 18 . While this preferred embodiment deals generally with the electrical interconnect between laminate 14 and chip 12 within a chip package, it is understood that the structure and methods described herein could be used on any planarized surface that provides component interconnections. Moreover, the figures are provided primarily for explanation purposes, and are not necessarily drawn to scale.
[0023] Referring now to FIG. 2 , the laminate 14 is depicted in detail, and includes receptor pads 30 on a top surface, BGA pads 32 on a bottom surface, a circuitized substrate 31 , and an external dielectric layer (EDL) 34 mounted on the top surface of the circuitized substrate 31 . EDL 34 may comprise a mask, a redistribution build-up layer, or any dielectric material that can insulate the top of the circuitized substrate 31 and include an adequate thickness for the purposes described herein. The circuitized substrate 31 comprises circuits 36 (e.g., voltage planes, ground planes, signal planes, vias, etc.) that electrically redirect electrical signals from BGA pads 32 to receptor pads 30 . Accordingly, in addition to providing a โlanding areaโ for the IC device, laminate 14 includes a multilayer structure that provides an electrical transition between relatively small receptor pads 30 (to handle the IC device) and relatively large BOA pads 32 (for surface mount connections).
[0024] Referring now to FIG. 3 , a cross-sectional side view of a receptor pad 30 in accordance with this invention is depicted. The receptor pad 30 is formed in laminate 14 , which includes a EDL 34 and a circuitized substrate 39 . EDL 34 , which provides an insulative surface on the laminate 14 , may be comprised of any dielectric material, such as epoxy, plastic, etc. The dielectric material may comprise an organic make-up. The EDL 34 may be affixed/created with any known method, such as with a โspray-onโ application, liquid screening, attachable film, etc. While the preferred thickness will be on the order of 2 mils, the resulting EDL can be any desired thickness. In the EDL 34 is an opening 40 having side wall surfaces 42 . The side walls can be oriented in a generally perpendicular fashion, or angled. Openings 40 can be created using any technique, including laser ablating, plasma etching, and photo imaging. On the surface of the circuitized substrate 39 , below the EDL 34 , is conductive element 38 . Conductive element 38 is one of many conductors residing within the circuitized substrate 39 , and could be any type of electrical conductor, such as a wire, signal plane, voltage/ground plane, via, etc. The receptor pad 30 is comprised of a microvia formed within an opening 40 in the EDL 34 . The microvia includes an electroplated layer 44 of copper that is in contact with conductive element 38 . While the electroplated layer 44 is shown as only a layer within the microvia, the layer 44 could fill the entire microvia structure. Copper plating of the microvias could also be achieved by using an electroless copper plating process, as opposed to electroplating. Alternatively, the microvia structure could be filled with an additional conductive material, such as conductive paste, silver, copper, etc. The electroplated layer 44 further comprises a lip 45 that overlaps the surface of the EDL 34 . The receptor pad 30 is designed to receive a solder deposit or bump 46 , that extends above the EDL.
[0025] Because a solder deposit or bump 46 (supplied during subsequent reflow processes) will not reliably wet (i.e., remain attached) directly to the interior side walls of the EDL 34 opening, this invention utilizes a metallically plated microvia to provide a surface that will reliably receive and maintain solder bump 46 . Without the plating, solder will not reliably flow over and adhere to the EDL walls, particularly if the EDL is comprised of an organic material. However, similar to the solder bump, a reliable system for attaching the electroplated layer 44 to the interior surface of the EDL 34 opening must likewise be implemented. Accordingly, the present invention provides a treated interior side wall surface 42 that is used to ensure adhesion of the plating 44 . For the preferred embodiment, the interior side wall surface 42 is treated in any known manner that will promote copper adhesion. For example, the interior wall 42 may include a surface that is โroughenedโ to enhance the adhesion of the electroplating 44 to the EDL 34 . Roughening may be achieved with, for example, a mechanical or a chemical process such as mechanical scrubbing, epoxy etching or plasma sanding.
[0026] Referring now to FIG. 4 , a flow chart describing the method for fabricating the receptor pads 30 and solder bump 46 is described. First, a circuitized substrate 39 with conductive elements on the surface is provided. Next, a EDL 34 is mounted on the surface of the circuitized structure 39 such that EDL openings expose the desired conductive elements and create microvias. Next, the interior side wall surfaces of the microvias are treated to enhance copper adhesion. The treatment may include, for example, any of the roughening methods described above.
[0027] Next, the interior surfaces of the microvias are electroplated with copper. This may be achieved with a multi-step โplate-upโ process that includes the application of a copper seed layer, followed by a full plating operation. The application of the seed layer may be accomplished with an electroless strike process that applies copper seeding to the treated side wall surfaces. Full panel electroplating with acid copper can then be used to finish the plating. This plating process may be accomplished with a bath process utilizing dip tanks, or any other known plating methods. As noted above, an electroless plating methodology could likewise be used. The result is a microvia (as well as the laminate surface) lined with metal plating. While the thickness of the plating may vary depending upon the particular application, this preferred embodiment contemplates a thickness of about 1 mil on the side walls and 0.7 mils on the bottom.
[0028] Alternatively, the microvia could be filled with a conductive material as described above.
[0029] Finally, the structure of the receptor pads are formed and finalized with a resist process to etch the pad. This process creates discrete pads on the laminate surface and eliminates copper from the laminate surface where it is not desired. Any known photo resist process to define the pads may be used, including the plate up and etch method described, or by using an additive or semi additive pattern plating process using electroless copper plating. Because the resultant microvia sidewalls have metal rather than bare epoxy, solder paste can wet down to the pad eliminating unreliable connections.
[0030] Once the pad is complete, a solder paste may be applied to the receptor pads to provide solder bumps. One method for applying solder paste to the receptor pads involves a โflip chipโ screen printing process. This process utilizes a solder screen printer, which is an automated tool used to deposit wet solder paste onto a card or any fine pitch, micro BGA, or chip carrier site. The screen printer utilizes a framed metal mask (stencil) with apertures in the same pattern array as the carrier. Typical BGA stencils are 8 mils thick with 30 mil diameter apertures. For this preferred embodiment, a 2 mil thick stencil with a 5-6 mil diameter aperture may be used.
[0031] The screen printer may utilize a high magnification vision system to align up the carrier with the stencil. After alignment is complete, a camera moves to the side and the carrier is automatically pushed up to the stencil thereby aligning the pads on the carrier to the stencil. Solder paste is applied to the stencil and squeegee blades or a printing head comes down in contact with the stencil, sweeping across, and depositing the wet solder onto the carrier. The carrier comes down away and out from the stencil and is removed. This process may be repeated multiple times. The carrier may then reflowed and washed and a visual inspection may be performed to inspect for missing bumps. Because the microvias are plated up (approximately 0.7 mils thickness in the bottom of the well), the result is a relatively small gap between the top of the receptor pad and the screened solder paste, which provides higher reliability.
[0032] While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention as defined in the following claims.
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A method for forming a plated microvia interconnect. An external dielectric layer (EDL) is mounted on a substrate in direct mechanical contact with a conductive element thereon. An opening in the EDL exposes the conductive element and create a microvia in the EDL. A sidewall and bottom wall surface of the microvia are treated to promote adhesion of copper and are plated with a layer of copper that includes a copper layer on a copper seed layer and is in direct mechanical and electrical contact with the conductive element. A wet solder paste is deposited on the layer of copper to overfill a remaining portion of the microvia. The solder paste is reflowed to form a solder bump in and over the remaining portion of the microvia to form the plated microvia interconnect. A stiffener is attached to the EDL using a first adhesive.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a method of and a device for increasing the yield of oil production in a process of producing bio-ethanol.
[0003] 2. Description of the Related Art
[0004] In known bio-ethanol plants stillage of grains such as corn is processed in order to produce ethyl alcohol, or so called bio-ethanol. The process usually is a dry milling process in which the starch in the grains is fermented. The fermentation creates a by-product or waste product, the so called whole stillage. The whole stillage is separated into distillers wet grains and the so called thin stillage. The thin stillage contains oil and is usually evaporated to become concentrated syrup and added to the solid waste materials to be dried and used as a supplement animal feed.
[0005] New efforts of improving this process are made by continuously pumping the concentrated syrup into a sedimentation tank and separating statically a part of the oil which is contained in the concentrated syrup. However, the yield of oil to be received in this new process is low.
[0006] Accordingly, a need exists for a method of and a device for increasing the yield of recovering oil in a process of producing bio-ethanol.
SUMMARY OF THE INVENTION
[0007] In accordance with one aspect of the invention, a method of increasing the yield of oil production in a process of producing bio-ethanol is disclosed, the method comprising: creating concentrated syrup as a by-product from an ethanol production, and recovering oil from the concentrated syrup, wherein the step of recovering oil from the concentrated syrup includes using a horizontal axis centrifuge, i.e., a centrifuge having a horizontal axis, and wherein the step of using a horizontal axis centrifuge includes using a bowl or drum, a discharge of deoiled syrup and a baffle plate or congestion plate, the baffle plate being located inside of the bowl and retaining oil from the discharge of deoiled syrup.
[0008] In accordance with another aspect of the invention, a device for increasing the yield of oil production in a process of producing bio-ethanol is disclosed, the device comprising: means for creating concentrated syrup as a by-product from an ethanol production, and means for recovering oil from the concentrated syrup, wherein said means for recovering oil from the concentrated syrup include a horizontal axis centrifuge, and wherein said horizontal axis centrifuge includes a bowl, a discharge of deoiled syrup and a baffle plate, the baffle plate being located inside of the bowl and retaining oil from the discharge of deoiled syrup.
[0009] In accordance with still another aspect of the invention, a method of increasing the yield of oil production in a process of producing bio-ethanol is disclosed, the method comprising: creating concentrated syrup as a by-product from an ethanol production, and recovering oil from the concentrated syrup, wherein the step of recovering oil from the concentrated syrup includes using a horizontal axis centrifuge, and wherein the step of using a horizontal axis centrifuge includes using a discharge of oil at a bowl of the horizontal axis centrifuge, the discharge diameter of which is 0.90 to 1.10 times of the respective diameter of a discharge of deoiled syrup.
[0010] In accordance with yet another aspect of the invention, a device for increasing the yield of oil production in a process of producing bio-ethanol is disclosed, the device comprising: means for creating concentrated syrup as a by-product from an ethanol production, and means for recovering oil from the concentrated syrup, wherein said means for recovering oil from the concentrated syrup include a horizontal axis centrifuge, and wherein said horizontal axis centrifuge includes a bowl, and a discharge of deoiled syrup and a discharge of oil at said bowl, the discharge diameter of said discharge of oil being 0.90 to 1.10 times of the respective diameter of said discharge of deoiled syrup.
[0011] In accordance with still a further aspect of the invention, a method of increasing the yield of oil production in a process of producing bio-ethanol is provided, the method comprising: creating concentrated syrup as a by-product from an ethanol production, and recovering oil from the concentrated syrup, wherein the step of recovering oil from the concentrated syrup includes using a horizontal axis centrifuge, and wherein the step of using a horizontal axis centrifuge includes using a three-phase horizontal axis centrifuge.
[0012] In accordance with yet another aspect of the invention, a device for increasing the yield of oil production in a process of producing bio-ethanol is disclosed, the device comprising: means for creating concentrated syrup as a by-product from an ethanol production, and means for recovering oil from the concentrated syrup, wherein said means for recovering oil from the concentrated syrup include a horizontal axis centrifuge, and wherein said horizontal axis centrifuge is a three-phase horizontal axis centrifuge.
[0013] Preferably the step of using a baffle plate inside of a bowl of the horizontal axis centrifuge includes using a baffle plate, the diameter of which is 0.70 to 0.95 times of the respective diameter of the bowl of the horizontal axis centrifuge.
[0014] In a preferred embodiment, the step of using a horizontal axis centrifuge includes discharging the recovered oil from the horizontal axis centrifuge by using an adjustable weir disk.
[0015] In another preferred embodiment, the step of using a horizontal axis centrifuge includes discharging the recovered oil from the horizontal axis centrifuge by using an impeller disk or peeling disk.
[0016] Further preferred, the step of creating concentrated syrup as a by-product from an ethanol production includes producing whole stillage, recovering thin stillage from the whole syrup by using a horizontal axis centrifuge and concentrating the thin stillage by using an evaporator.
[0017] In a further preferred embodiment, the step of recovering oil from the concentrated syrup includes storing the concentrated syrup in a storage tank before conducting it to the horizontal axis centrifuge.
[0018] The step of conducting the concentrated syrup from the storage tank to the horizontal axis centrifuge further preferably includes drawing off the concentrated syrup at the top of the syrup stored in the storage tank.
[0019] Finally, in a further preferred embodiment the step of using a horizontal axis centrifuge includes providing a centrifugal acceleration of 1800 to 2100รG, preferably 1900 to 2000รG, most preferred 1960รG on the concentrated syrup in the horizontal axis centrifuge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic flow chart illustrating the process of producing bio-ethanol and creating whole stillage as a by-product of said production of bio-ethanol.
[0021] FIG. 2 is a schematic flow chart illustrating the processing of the whole stillage of the bio-ethanol production of FIG. 1 according to the prior art.
[0022] FIG. 3 is a schematic flow chart illustrating the processing of the whole stillage of the bio-ethanol production of FIG. 1 according to the invention, in order to increase the yield of oil production in the production of bio-ethanol.
[0023] FIG. 4 is a longitudinal sectional view of a first embodiment of a device for increasing the yield of oil production in the process of producing bio-ethanol according to the invention.
[0024] FIG. 5 is a longitudinal sectional view of a device similar to FIG. 4 modified according to the invention.
[0025] FIG. 6 is a longitudinal sectional view of a second embodiment of a device for increasing the yield of oil production in the process of producing bio-ethanol according to the invention.
[0026] FIG. 7 is a longitudinal sectional view of a device similar to FIG. 6 modified according to the invention.
[0027] FIG. 8 is a longitudinal sectional view of a third embodiment of a device for increasing the yield of oil production in the process of producing bio-ethanol according to the invention.
[0028] FIG. 9 is a longitudinal sectional view of a device similar to FIG. 8 modified according to the invention.
[0029] FIG. 10 is a longitudinal sectional view of a forth embodiment of a device for increasing the yield of oil production in the process of producing bio-ethanol according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] In FIG. 1 a method 10 of producing bio-ethanol is shown. In a first step of this method 10 , grain 12 such as corn, is provided and milled in a step 14 . After said milling, water 16 and enzymes 18 are added. By heating of the mixture a liquefaction of starch is started and the enzymes provide a decomposition of starch into sugar in a step 20 . A further fermentation takes place in a step 22 converting the sugar into ethanol.
[0031] The step 22 is followed by a distillation step 24 in which bio-ethanol 26 is received. The by-product of the distillation step 24 , a so called whole stillage 27 , is further separated mechanically in a step 28 via a horizontal axis centrifuge, preferable a two-phase helical conveyor centrifuge. In said step 28 the whole stillage 27 is separated into a solid phase, the so called distillers wet grains 30 , and a liquid phase, the so called thin stillage 32 .
[0032] In FIG. 2 the further processing of the distillers wet grains 30 and the thin stillage 32 according to the prior art is depicted. The thin stillage 32 is conducted to an evaporation step 34 in which water 36 is removed from a so called syrup 38 . The syrup 38 is added to the distillers wet grains 30 and dried in a step 40 in order to receive so called distillers dried grains with solubles 42 . The distillers dried grains with solubles 42 is used as a supplement animal feed.
[0033] In FIG. 3 the further processing of the thin stillage 32 according to the invention is depicted. The process according to the invention differs from the one of FIG. 2 in that the syrup 38 is conducted to a sedimentation or storage tank 44 and further to a horizontal axis centrifuge 46 . The line for conducting the syrup 38 from the storage tank 44 to the horizontal axis centrifuge 46 is advantageously connected to the storage tank 44 above the feed of the storage tank 44 . Alternatively, the line is connected to the bottom of the storage tank 44 . Further preferred, the syrup 38 is conducted directly to the horizontal axis centrifuge 46 . The horizontal axis centrifuge 46 is especially adapted to recover a large amount of oil 48 out of the syrup 38 for improving the yield of recovering oil in said process 10 of producing bio-ethanol 26 .
[0034] The rest of the syrup 38 , a so called deoiled syrup 50 , is conducted to the above mentioned step 40 in which it is dried, in order to become distillers dried grains with solubles 42 .
[0035] FIG. 4 shows a first embodiment of a horizontal axis centrifuge 46 which is used in the process of FIG. 3 for recovering oil 48 from the concentrated syrup 38 . The horizontal axis centrifuge 46 includes a horizontal rotation axis 52 and two bearings 54 and 56 on which a bowl or bowl 58 having a rotatable screw 60 therein is supported rotationally with respect to the axis 52 . The horizontal axis centrifuge 46 provides a centrifugal acceleration of 1800 to 2100รG, preferably 1900 to 2000รG, most preferred 1960รG on syrup 38 , which is located in the horizontal axis centrifuge 46 .
[0036] The bowl 58 is provided with a first outlet 62 for a โliquid phaseโ and a second outlet 64 for a โsolid phaseโ. The first outlet 62 is provided with an adjustable weir disk or plate 66 at one of the front walls of the bowl 58 , and the second outlet 64 is provided at the opposite front wall of the bowl 58 at a conical part 58 a thereof. The conical part 58 a forms nearly one half of the outer wall of the bowl 58 . The screw 60 serves as a transportation means in order to discharge material from a cylindrical part 58 b of the bowl 58 radial inwardly along the conical part 58 a and out of the second outlet 64 .
[0037] The syrup 38 to be separated in the horizontal axis centrifuge 46 is conducted into the bowl 58 through an inlet 68 in the centre of the screw 60 . The recovered oil 48 is discharged via the first outlet 62 across the adjustable weir disk 66 , which may be adjusted even during rotation of bowl 58 and screw 60 . The deoiled syrup 50 is discharged via the screw 60 along said conical part 58 a through the second outlet 64 .
[0038] In order to further improve the process of discharging the deoiled syrup 50 relative to the recovered oil 48 , a modified horizontal axis centrifuge 46 is depicted in FIG. 5 , which is similar to the one of FIG. 4 except of a baffle plate 68 being located in one of the windings of screw 60 at the transition of the cylindrical part 58 b to the conical part 58 a of the bowl 58 . The baffle plate 68 serves to retain oil 48 from the second outlet 64 , said oil 48 floating on the syrup 38 in the radial inner part of bowl 58 . The baffle plate 68 is located at the screw 60 alternatively at the transition between the cylindrical part and the conical part of its windings. The baffle plate 68 begins at the hub of the screw 60 and is directed radial outwardly. It should be directed approximately lengthwise, i.e., in one of the planes in which the horizontal rotation axis 52 is located (see FIG. 5 ). Alternatively, the baffle plate 68 may be directed orthogonal to the horizontal rotation axis 52 .
[0039] The baffle plate 68 further helps to transport the deoiled syrup to the second discharge 64 . The deoiled syrup is very soft or pasty. Thus, the deoiled syrup is transported as a โheavy phaseโ via an accumulation at the baffle plate 68 . In other words, the deoiled syrup is pressed under the baffle plate 68 and up the conical part 58 a . In order to improve said transport of deoiled syrup, the diameter of the baffle plate 68 is 0.70 to 0.95 times of the respective diameter of the bowl 58 .
[0040] In FIG. 6 a second embodiment of a horizontal axis centrifuge 46 for recovering oil 48 from the concentrated syrup 38 according to the process of FIG. 3 is shown. The horizontal axis centrifuge 46 of FIG. 6 also includes a horizontal rotation axis 52 and two bearings 54 and 56 on which a rotatable drum or bowl 58 having a rotatable screw 60 therein is supported. The bowl 58 is again provided with a first outlet 62 for a โliquid phaseโ and a second outlet 64 for a โsolid phaseโ. The first outlet 62 is provided with an impeller disk 70 at a front wall of the bowl 58 which is opposite of a conical part 58 a.
[0041] The syrup 38 to be separated in the horizontal axis centrifuge 46 is again conducted into the bowl 58 through an inlet 68 . The recovered oil 48 is discharged under pressure via the first outlet 62 through the impeller disk 70 , which may be adjusted even during rotation of bowl 58 and screw 60 . The deoiled syrup 50 is again discharged via the screw 60 along said conical part 58 a through the second outlet 64 . For improvement of the process of discharging the deoiled syrup 50 relative to the recovered oil 48 , FIG. 7 shows a modified horizontal axis centrifuge 46 in which a radial directed baffle plate 68 is located in one of the windings of screw 60 at the transition of the cylindrical part 58 b of the bowl 58 and conical part 58 a.
[0042] FIG. 8 shows a third embodiment of a horizontal axis centrifuge 46 for the recovering of oil 48 according to the process of FIG. 3 . The horizontal axis centrifuge 46 of FIG. 8 is a three-phase horizontal axis centrifuge also including a horizontal rotation axis 52 and two bearings 54 and 56 on which a rotatable drum or bowl 58 and a rotatable screw 60 are supported. The bowl 58 is provided with a first outlet 62 for a โfirst liquid phaseโ, a second outlet 64 for a โsolid phaseโ, and a third outlet 72 for a โsecond liquid phaseโ.
[0043] The syrup 38 to be separated in the horizontal axis centrifuge 46 is again conducted into the bowl 58 through an inlet 68 .
[0044] The first outlet 62 is provided with an adjustable weir disk 66 and serves for discharging recovered oil 48 .
[0045] The second outlet 64 is usually not used for discharging any material during the process of separating syrup 38 . In contrast, the second outlet 64 serves for finally emptying the bowl 58 after the end of operation of the horizontal axis centrifuge 46 . The screw 60 helps to spread the syrup 38 into the bowl 58 during the process of separation and to discharge residual material through the second outlet 64 at the end of the process.
[0046] The deoiled syrup 50 is discharged under pressure via the third outlet 72 , which is provided with an adjustable impeller disk 70 .
[0047] Alternatively, the second outlet 64 may serve for additionally discharging deoiled syrup 50 out of the bowl 58 . Therefore, the deoiled syrup 50 is discharged via the screw 60 along the conical part 58 a.
[0048] For further improving the process of discharging the deoiled syrup 50 through the second outlet 64 relative to the recovered oil 48 , FIG. 9 shows a modified three-phase horizontal axis centrifuge 46 in which a radial directed baffle plate 68 is located in one of the windings of screw 60 at the transition of the cylindrical part 58 b and conical part 58 a of the bowl 58 . The first outlet 62 thereby forms a discharge of oil the discharge diameter of which being 0.90 to 1.10 times of the respective diameter of a corresponding discharge of deoiled syrup.
[0049] In FIG. 10 a fourth embodiment of a horizontal axis centrifuge 46 for the recovering of oil 48 according to the process of FIG. 3 is depicted. The horizontal axis centrifuge 46 of FIG. 10 is a two-phase horizontal axis centrifuge including a horizontal rotation axis 52 around which a rotatable drum or bowl 58 is located. The bowl 58 is provided with a first outlet 62 and a second outlet 64 , both provided at one side wall of the bowl 58 . Alternatively, the second outlet 64 may be provided at a side wall opposite to the one of the first outlet 62 .
[0050] The syrup 38 to be separated in the horizontal axis centrifuge 46 of FIG. 10 is again conducted into the bowl 58 through an inlet 68 .
[0051] The first outlet 62 is provided with an adjustable weir disk 66 and serves for discharging recovered oil 48 .
[0052] The second outlet 64 includes an adjustable impeller disk 70 and serves for discharging deoiled syrup 50 under pressure.
[0053] Further, at the horizontal axis centrifuge 46 of FIG. 10 (non-depicted) means for finally cleaning and removing residual material out of the bowl 58 may be provided.
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A method of increasing the yield of oil production in a process of producing bio-ethanol in particularly comprises: creating concentrated syrup as a by-product from an ethanol production, and recovering oil from the concentrated syrup, wherein the step of recovering oil from the concentrated syrup includes using a horizontal axis centrifuge, and wherein the step of using a horizontal axis centrifuge includes using a bowl, a discharge of deoiled syrup and a baffle plate, the baffle plate being located inside of the bowl and retaining oil from the discharge of deoiled syrup.
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CLAIM FOR PRIORITY
This application claims priority from Japanese Application No. 2000-105468, filed on Apr. 6, 2000, and which is hereby incorporated by reference as if fully set forth herein.
1. Field of the Invention
The present invention relates to a compiler that can effectively optimize a program that includes branches.
2. Background of the Invention
Normally, before the source code for a program written in one of the high-level programming languages is finally compiled, code optimization is employed to improve the execution performance and the efficiency of the machine language executable program into which the source code is converted.
However, when the program includes branches, the optimization effects are generally deteriorated. Especially for data flow optimization, which is an important optimization process, the effects obtained by optimization are considerably deteriorated for a program that includes branches. This is because, in the data flow analysis used for the data flow optimization, when the program includes branches, the execution results provided by the code used for branched paths adversely affect the operation that is to be performed after the branches have been merged, so that efficient optimization is difficult.
Among the branches that appear in a program, there is a branch whereat the execution frequencies of the individual paths are very biased and the program almost always branches in one direction only. However, in data flow optimization, the affect of the code along a path to which the program seldom branches can not be ignored at all. Therefore, since the affect of the code along the path to which the program seldom branches must be taken into account, the optimization effects are deteriorated.
Conventionally, to perform data flow optimization, a method is employed whereby a point at which branches merge is simply removed, even when branches are present in a program. FIG. 11 is a diagram showing the eventual state when a program is developed using this method. As is shown in FIG. 11 , according to this method, a command positioned following a branch merging point is copied, and the command copies are portioned following the branched paths (portions preceding the merging point). These commands are transformed into special codes that depend on several contexts of the individual branches. Therefore, the branches are not merged, and are maintained separately and are handled as multiple processes. As a result, optimization can be performed for the process for each branched path, and the execution speed can be increased.
As is described above, among the optimization processes performed during the program compiling processing, especially the data flow optimization, the effects are deteriorated when a program includes branches. In particular, when, depending on the branches, the execution frequency is biased, the optimization effects are reduced due to the presence of code that is rarely executed during the actual processing.
On the other hand, according to the above conventional method, optimization can be accomplished by removing the merging point of branches. However, when a plurality of branches and merges are arranged in series in a program, the amount of code is increased exponentially in consonance with the number of branches. FIG. 12 is a diagram showing the eventual state when a program wherein multiple branches and merges are arranged in series is developed by removing merges, and the drastic, exponential increase in the amount of code that employing the procedure entails. As is evident from the diagram, when the amount of code is increased, realistically, an optimization process can not actually be performed. Therefore, conventionally, for this structured program effective optimization is impossible.
SUMMARY OF THE INVENTION
The present invention broadly contemplates effectively performing a data flow optimization process for a program wherein a plurality of branches and merges are arranged in series, without incurring a drastic increase in the amount of code. The present invention also contemplates a method whereby a control flow graph is effectively modified in order to perform a data flow optimization process for a program wherein multiple branches and merges are arranged in series, and wherein the execution frequency in these branches differs greatly.
In accordance with one aspect of the present invention, a compiler for converting source code for a program written in a programming language into an object program written in a machine language is provided, which comprises: an optimization execution unit for performing optimization of the object program written in the machine language; and a program modification unit for, before the optimization process is performed by the optimization execution unit, modifying the object program to provide a form that is appropriate for the optimization, wherein, when the object program includes a branch, the program modification unit selects at the branch a specific path to extract, relative to the branch, a series of paths that are not merged.
Since relative to the branch a series of paths that are not merged are extracted from the object program, even data flow optimization, which will produce code for the branched paths that will provide execution results that will affect the operation of the program after the branches are merged, can be performed without taking the branches into account. The optimization execution unit performs the optimization for the paths that are extracted by the program modification unit. Since a series of paths, which relative to the branch are not merged and which are extracted from the object program, is designated as the target for the optimization, optimization can be performed effectively. Especially, since the data flow optimization can be performed for a series of paths that are not merged relative to the branch, an extremely effective optimization process can be performed.
When differences in execution frequencies depend on a plurality of paths at the branch in the object program, the program modification unit selects a path having a higher execution frequency, and relative to the branch, extracts a series of paths that are not merged. This configuration is superior because the path to be optimized is a path having a high execution frequency, and thus the overall process efficiency of the optimized program can be greatly increased.
In accordance with another aspect of the present invention, a compiler, for converting source code for a program written in a programming language into an object program in a machine language provided, which comprises: a path determiner, for selecting, when the object program in the machine language includes a branch, a specific path at the branch for determining a series of target paths for optimization; a control flow graph modification unit, for modifying a control flow graph for the object program to separate the optimized target paths from other paths; and an optimization execution unit for employing the control flow graph obtained by the control flow graph modification unit to perform optimization of the optimization target paths.
With this arrangement, since the optimization process is performed for target paths that are extracted from the program, the paths are increased and it is not necessary, each time a branch appears, for a command at a branch merging point to be copied. Therefore, even for a program wherein branches and merges are arranged in series, the phenomenon can be avoided wherein the amount of code drastically increases as the program is developed.
The control flow graph modification unit extracts the optimization target paths from the control flow graph for the object program, and defines the optimization target paths as paths that, relative to the branch, are not to be merged; and copies path segments that are included in the optimization target paths and connects the copies of the path segments to paths other than those for the optimization target paths, thereby separating the control flow graph into the optimization target paths and into paths that are formed using the copies of the path segments and the paths that are not included in the optimization target paths. This arrangement is preferable because a series of executable paths can be formed for the program portion after the optimization target paths have been extracted from the program.
From among the paths included in the optimization target paths, the control flow graph modification unit copies path segments at locations other than those whereat the object program branches into a plurality of paths, and connects the copies of the path segments to the paths that are not included in the optimization target paths. This configuration is preferable because an increase in the amount of code after the control flow graph has been developed can be suppressed.
In accordance with another aspect of the present invention, a computer system is provided that includes a compiler, for converting source code for a program written in a programming language into an object program in a machine language is provided, which comprising: a path determiner, for selecting, when the object program in the machine language includes a branch, a specific path at the branch for determining a series of target paths for optimization; a control flow graph modification unit, for modifying a control flow graph for the object program to separate the optimized target paths from other paths; and an optimization execution unit for employing the control flow graph obtained by the control flow graph modification unit to perform optimization of the optimization target paths. This configuration is preferable because, for program compiling, this computer system provide effective optimization for a program wherein branches and merges are arranged in series.
In accordance with another aspect of the present invention, an optimization method for performing optimization to improve process efficiency of a program is provided, which comprises the steps of: selecting, when a program includes a branch, a specific path at the branch for determining a series of target paths for optimization; modifying a control flow graph for the program to separate the optimized target paths from other sub-paths; and employing the control flow graph obtained by the control flow graph modification unit to perform optimization of the optimization target paths. With this arrangement, even for a program wherein branches and merges are arranged in series, the phenomenon can be avoided wherein the amount of code drastically increases as the program is developed.
The step of modifying the control flow graph includes steps of: copying all optimization target paths, for a sub-path that is led to an optimization target path, that can be reached from a point whereto the sub-path is led; copying all the paths that extend from the point whereto the sub-path is led to the copied paths; changing the connections of all the edges of the optimization target path from the sub-path to the connections for the copied paths; changing, when there is an edge that externally flows to the optimization target path and when the edge is the edge of the sub-path, the connection of the edge connecting the edge to the copied paths; and forming a merging point, consisting of a first block at a starting point for the edge and a second block along a copied path that corresponds to the first block, and replacing an edge that flows out from the optimization target path with an edge from the merging point. This arrangement is preferable because a series of executable paths can be formed for the program portion after the optimization target paths have been extracted from the program.
At the two steps of copying paths, the copying of a path is eliminated for a location whereat the program branches into a plurality of paths. This configuration is preferable because an increase in the amount of code after the control flow graph has been developed can be suppressed.
In accordance with another aspect of the present invention, an optimization method for performing optimization in order to improve the processing efficiency of a program is provided, which comprises the steps of: when a program includes a branch, selecting at the branch a specific path from which to extract, relative to the branch, a series of paths that are not merged; and performing optimization for the paths that are selected.
Since a series of paths that are not merged relative to the branch can be defined as target optimization, an extremely effective optimization process can be performed particularly for the data flow optimization. At the step of extracting paths from the program, when differences in execution frequencies depend on a plurality of paths at the branch in the object program, a path having a higher execution frequency is selected, and a series of paths that are not merged are selected relative to the branch. This configuration is superior because the path to be optimized is a path having a high execution frequency, and thus the overall process efficiency of the optimized program can be greatly increased.
In accordance with another aspect of the present invention, an optimization program, for permitting a computer to perform optimization of an object program, is provided and comprises: a process for selecting, when the object program in the machine language includes a branch, a specific path at the branch for determining a series of target paths for optimization; a process for modifying a control flow graph for the object program to separate the optimized target paths from other sub-paths; and a process for employing the obtained control flow graph to perform optimization of the optimization target paths.
In accordance with another aspect of the present invention, a storage medium is provided on which input means for a computer stores a computer-readable program that permits the computer to perform: a process for selecting, when the object program in the machine language includes a branch, a specific path at the branch for determining a series of target paths for optimization; a process for modifying a control flow graph for the object program to separate the optimized target paths from other sub-paths; and a process for employing the obtained control flow graph to perform optimization of the optimization target paths.
In accordance with yet another aspect of the present invention, a program transmission apparatus comprises: storage means for storing a program that permits a computer to perform a process for selecting, when the object program in the machine language includes a branch, a specific path at the branch for determining a series of target paths for optimization, a process for modifying a control flow graph for the object program to separate the optimized target paths from other sub-paths, and a process for employing the obtained control flow graph to perform optimization of the optimization target paths; and transmission means for the reading of the program from the storage means and the transmission of the program. This configuration is preferable because, when a computer on which this program has been installed is operated as a compiler, effective optimization can be performed, even when a target object program includes branches.
For a better understanding of the present invention, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, and the scope of the invention that will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram for explaining the configuration of an optimization processor in a compiler according to one embodiment of the present invention.
FIG. 2 is a flowchart for explaining the processing performed by a control flow graph modification unit according to the embodiment.
FIG. 3 is a diagram showing a modification example for the control flow graph of a program obtained by the control flow graph modification unit according to the embodiment.
FIG. 4 is a diagram showing a modification example for the control flow graph for this embodiment when main paths are not copied.
FIG. 5 is a flowchart for explaining the algorithm for the control flow graph modification process according to the embodiment.
FIG. 6 is a diagram showing an example application of the algorithm for the control flow graph modification process in FIG. 5 , wherein the control flow graph is modified while the path from a merging point 2 to a branching point 3 is focused on.
FIG. 7 is a diagram showing another example application for the algorithm for the control flow graph modification process in FIG. 5 , wherein the control flow graph is modified while the path from a merging point 4 to the branching point 3 is focused on.
FIG. 8 is a diagram showing another example application for the algorithm for the control flow graph modification process in FIG. 5 , wherein the control flow graph is modified while the path from the merging point 4 to the branching point 3 is focused on.
FIG. 9 is a diagram showing another example application for the algorithm for the control flow graph modification process in FIG. 5 , wherein the control flow graph is modified while the path from the merging point 4 to a branching point 5 is focused on.
FIG. 10 is a diagram showing another example application for the algorithm for the control flow graph modification process in FIG. 5 , wherein the control flow graph is modified while the path from the merging point 4 to the branching point 5 is focused on.
FIG. 11 is a diagram showing the development of a program when a conventional method is used that simply removes merging points of branches.
FIG. 12 is a diagram showing the state where the amount of code is drastically increased when a program wherein multiple branches and merges are arranged in series is developed using the conventional method for removing the merges.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The presently preferred embodiment of the present invention will now be explained in detail while referring to the accompanying drawings.
FIG. 1 is a diagram for explaining the configuration, according to the embodiment of the present invention, of an optimization processor included in a compiler. In FIG. 1 , an optimization processor 10 optimizes a machine language object code program. An optimization target path determiner 11 determines which path, of multiple paths generated by branching the program, is to be optimized (hereinafter referred to as an optimization target path). A control flow graph modification unit 12 modifies a control flow graph for the target program based on the determination made by the optimization target path determiner 11 , and an optimization execution unit 13 employs the control flow graph modified by the control flow graph modification unit 12 to perform an optimization process, including data flow optimization, for the optimization target path selected by the optimization target path determiner 11 .
In the portion whereat the target program branches into multiple paths, the optimization target path determiner 11 selects an optimization target path from among those multiple paths, and merges the selected path into the path at the merging point in order to provide a path to be used as an optimization target. The path having the highest execution frequency (hereinafter referred to as a main path) is generally selected as the optimization target path. However, strictly speaking, the optimization target path does not always include all the main paths, and may include a path having a low execution frequency (hereinafter referred to as a rare path), or may include both a main path and a rare path. In the explanation for this embodiment, a main path is employed as the optimization target path.
The optimization target path is determined based on a resource available for the compiler, the branching frequency and the optimization scheme. The method for dynamically determining the optimization target path during the execution of the algorithm can also be employed.
The control flow graph modification unit 12 divides the control flow graph for the target program into an optimization target path, determined by the optimization target path determiner 11 , and paths including the other paths. In this embodiment, since the main path is employed as the optimization target path, the control flow graph modification unit 12 divides the control flow graph into the optimization target path and the remainder of the paths, including the rare paths.
Since following the branching of the program the main path and a block at the merging portion are included in the optimization target path, if the control flow graph of the program is simply divided into two path types, the block at the merging point is omitted from the sub-paths, including the rare paths, and only an incomplete code array is obtained. Thus, a necessary block is supplemented.
FIG. 2 is a flowchart for explaining the processing performed by the control flow graph modification unit 12 . In FIG. 2 , first, for a rare path that flows into a predetermined optimization target path, all the optimization target paths are copied that can be reached from the point at which the rare path flows into the predetermined optimization target path (step 201 ). Following this, all the paths are copied that can reach from the above described point to the optimization target paths that were copied (step 202 ). The connections of all the edges leading from the optimization target paths to the rare path are changed to those paths that were copied (step 203 ). If there is an edge that externally flows into the optimization target path, and if the pertinent edge is an edge from the rare path, the connection of this edge is changed and it is connected to a copied path (steps 204 , 205 and 206 ). If there is no edge externally flowing into the optimization target path, or if the edge that is externally flowing into the optimization target path is not from the rare path, the connection of this edge to the optimization target path is not changed. Next, if there is an edge that flows out from the optimization target path, a new merging point for the block at the starting point for the edge and a corresponding copied block is prepared, and the edge is replaced with an edge from the new merging point (steps 207 and 208 ). The above processing is performed for all the rare paths that flow into the optimization target paths. For the processing performed for the other rare paths, portions that were previously copied are not copied again, and only a corresponding portion is performed.
FIGS. 3A and 3B are diagrams showing a modification example of the control flow graph for a program obtained by the control flow graph modification unit 12 . In FIGS. 3A and 3B , paths indicated by thick lines are optimization target paths. As is shown in FIG. 3A , the main paths and the blocks whereat the paths are merged are selected as optimization target paths. By referring to FIG. 3B , which shows the modified state, block copies indicated by broken lines are generated by the processes at steps 201 and 202 . Further, a necessary edge connection is performed by the process used from step 203 to step 208 .
The optimization execution unit 13 performs the optimization process for the optimization target paths based on the control flow graph that is thus developed by the control flow graph modification unit 12 . As is shown in FIG. 3 , since the optimization target paths do not include branches, the effects are not deteriorated for all the optimization processes, including the data flow optimization.
Therefore, the processing performed by the optimization target path determiner 11 , the control flow graph modification unit 12 and the optimization execution unit 13 in the optimization processor 10 correspond to the processing performed where a series of paths that do not merge at the branches is extracted from a program that includes branches, and the optimization process is performed only for the extracted paths. The processing efficiency of the optimized program can be improved when the program is executed along the paths for which the optimization has been performed. On the other hand, the process efficiency is not improved when the program is performed along the other paths. However, for the program whereby multiple branches and merges are arranged in series, as is shown in FIG. 3 , since the optimization process can not actually be performed by the conventional method used for removing the merging points, the processing efficiency of the program in FIG. 3A is equivalent to the processing efficiency attained by the program performed by the conventional method.
Furthermore, as is shown in FIG. 3B , along the optimization target path, the edge to a rare path is connected to a portion where a branch was present before the control flow graph was modified. On the other hand, there is no edge connected to the portion whereat a branch is present before the control flow graph was modified. Therefore, for the execution of the program along the optimization target paths, the program is branched to the process along the paths including the rare paths, and the following process is performed along the paths that include the rare paths, i.e., the program that is not optimized is executed.
As is described above, in the embodiment, the program including the branches and merges is developed along the control flow graph, and the optimization target paths are obtained by removing the merges at the branches, and are optimized. Therefore, even the data flow optimization, for which the optimization effects are considerably reduced in the program that include branches, can be performed without deterioration of the effects. Further, in this embodiment, the optimization target paths are extracted from the program that includes the branches and for the other paths, the application of the optimization is not taken into account. Therefore, the program need not be developed for all the branches. Thus, even when the branches and merges are arranged in series in the program, the amount of code is not drastically and exponentially increased.
In addition, in the embodiment the main paths having high execution frequencies are selected to form optimization target paths. Therefore, when the program modification as is shown in FIG. 3B is executed, almost all the processes are executed along the optimized paths, and only when, as an exception, the program control is shifted along the rare path is the following process performed along the non-optimized path. Therefore, the overall processing efficiency can be considerably enhanced.
As a special program form having branches whose execution frequencies are biased, there is a program where the process for the main path is included in a rare path. In such a program, for example, when
if(a==0) then A else B,
the process B is generally written while a=0 is taken into account. This case appears during the devirtualization performed by an optimization compiler in an object oriented language. If the program control is shifted from a branch having this property to the rear path, the following process need only be performed along the rare path and the block at the merging portion, so that only the block at the merging portion is copied to the rare path side, while the main path is not doubled. As a result, an increase in the amount of code can be suppressed.
FIGS. 4A and 4B are diagrams showing the modification of the control flow graph when the main paths are not copied.
Comparing FIG. 4 with FIG. 3 , the optimization target paths are identical and are formed of main paths and blocks at merging portions. The paths, including rare paths, are formed only of the copies of the blocks at the merging points and the rare paths, and the main paths are not copied. Therefore, branches are not present along the paths, including the rare paths, and only edges (merges) that flow from the optimization target paths are present.
FIG. 5 is a flowchart for explaining an algorithm for the control flow graph modification processing in this embodiment. Assume that, for all the branches to be processed by the algorithm, the processes along the main paths are included in the process along the rare paths. The selection of the optimization path is performed incrementally during the algorithm. That is, it may be understood that the optimization path is repetitively processed instead of the following copying target paths.
In FIG. 5 , first, a branch point of a main path and a rare path, which can be reached from a predetermined merging point for a main path and a rare path, is detected (step 501 ). If such a branch point is not detected, the processing is thereafter terminated. Then, detect all the paths connecting the merging point and the detected branching point (step 502 ). The detected path is hereinafter called a copying target path. A block and an edge along the copying target path are copied (step 503 ). Then, the merging point is deleted, and the main path that flowed into the merging point is connected to the copying target path. Further, the rare path that flowed into the merging point is connected to the copied path (step 504 ). The copied path is connected to the branch to the rare path (step 505 ). If there is an edge that externally flows to the copying target path and if that edge is from the rare path, the edge is re-connected to the copied path (steps 506 , 507 and 508 ). But if there is no edge that externally flows into the copying target path, or if an edge externally flowing into the copying target path is not from the rare path, the connection to the copying target path is maintained. If there is an edge flowing out from the coping target path, a new merging point for the block at the starting point for the edge and a corresponding copied block is prepared, and the above edge is replaced with the edge from the new merging point (steps 509 and 510 ). The above processing is recurrently repeated to modify the control flow graph.
FIGS. 6 to 10 are diagrams showing application examples of the algorithm explained while referring to FIG. 5 .
In FIG. 6 , first, a merging point 2 and a branching point 3 that can be directly reached from the merging point 2 are focused on (step 501 ), and a path extended from the merging point 2 to the branching point 3 is defined as a copying target path (step 502 ). Blocks D and E along the path between the merging point 2 and the branching point 3 are copied, and the edge is connected from a copied block Dโฒ to a copied block Eโฒ (step 503 ). Following the block Eโฒ, the edge is not connected to the branching point 3 , but instead, is directly connected to a block G that is branched at the branching point 3 (step 504 ). Since the edge that externally flows into the block E is not an edge from a rare path, no process is performed. From among the paths extended from a merging point 4 , there are two proposed paths that can be copied. Therefore, for the following modification there are two process.
One of the processes is the copying of a path from the merging point 4 to the branching point 3 . FIGS. 7 and 8 are diagrams showing the modification of the control flow graph performed in this case.
In FIG. 7 , first, blocks H and E along this path are copied (step 503 ). It should be noted that when the process is initiated at this point, the block E must be copied, but that if it was copied at the preceding step, it need not be copied again. Next, the edge is connected from a copied block Hโฒ to a copied block Eโฒ (step 503 ). Since the edge connected to a block I is an edge flowing externally, a new merging point is prepared, and the edges from the blocks H and Hโฒ are connected thereto (step 510 ).
Following this, in FIG. 8 , the block I, along the path leading from the merging point 4 to a branching point 5 in the control flow graph in FIG. 7 , is copied (step 503 ), and then, the edge is connected from the block Hโฒ to the block Iโฒ (step 504 ). Further, following the block Iโฒ the edge is not connected to the branching point 5 , but instead is directly connected to a block K that is branched at the branching point 5 (step 504 ).
The other modification process is a process for copying the path from the merging point 4 to the branching point 5 , and FIGS. 9 and 10 are diagrams showing a modification of the control flow graph in this case.
In FIG. 9 , first, a block H and a block I along this path are copied, and the edge is connected from a copied block Hโฒ to a copied block Iโฒ (step 503 ). Following the block Iโฒ, the edge is not connected to the branching point 5 , but instead is connected to a block K that is branched from the branching point 5 (step 508 ). Further, since the edge connected to a block E is an edge that flows externally, a new merging point is prepared and the edges from the blocks H and Hโฒ are connected thereto (step 510 ).
Following this, in FIG. 10 , the block E along the path between the merging point 4 and the branching point 2 is copied (step 503 ). However, if the block E was copied at the preceding step, at this time, only the edge is led from the block Hโฒto the block Eโฒ, and since the edge externally flowing into the block E is not an edge from a rare path, no process is performed.
While referring to FIGS. 8 to 10 , regardless of whether the process ( FIGS. 7 and 8 ) for copying the path from the merging point 4 to the branching point 3 , or the process ( FIGS. 9 and 10 ) for copying the path from the merging point 4 to the branching point 5 is performed for modification, the same control flow graph is finally obtained.
In the described manner, the control flow graph shown in FIG. 6 is developed into the optimization target path A-B-D-E-F-H-I-J-L, which consists of the main paths, and a path A-C-Dโฒ-Eโฒ-G-Hโฒ-Iโฒ-K-L, which consists of rare paths and for which the optimization effects are not taken into account. Thereafter, the optimization execution unit 13 performs the optimization process for the optimization target path A-B-D-E-F-H-I-J-L.
It is to be understood that the present invention, in accordance with at least one presently preferred embodiment, may be implemented on at least one general-purpose computer running suitable software programs. It may also be implemented on at least one Integrated Circuit or part of at least one Integrated Circuit. Thus, it is to be understood that the invention may be implemented in hardware, software, or a combination of both.
If not otherwise stated herein, it is to be assumed that all patents, patent applications, patent publications and other publications (including web-based publications) mentioned and cited herein are hereby fully incorporated by reference herein as if set forth in their entirety herein.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention.
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A compiler is provided which effectively performs a data flow optimization process for a program wherein a plurality of branches and merges are arranged in series, without incurring a drastic increase in the amount of code. The compiler, and the method thereof, may be implemented in hardware, software, or both.
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CROSS REFERENCE TO RELATED PATENT APPLICATIONS
The application claims the benefit of the priority filing date of the provisional patent application, bearing Ser. No. 60/676,125, which was filed on May 2, 2005.
BACKGROUND OF THE INVENTION
1) Field of the Invention
The invention relates to a portable feeding kit, and more particularly a portable feeding kit for children.
2) Prior Art
U.S. Pat. No. 4,895,258 to Luigi Bertoli teaches a compact utensil set, where the set of utensils are contained in a case-container. Bertoli teaches that the set contains all the main things required for consuming food and drink, neatly arranged within a very limited space. A special feature of the set is that all the component parts are made specially to make best use of the space available, to be compact and hygienic, and to keep weight down to a minimum.
U.S. Publication 2004/0245258 to Connors, James A. Jr. et al. teaches a disposable child's drinking cup, which has a lid with a drinking spout defining multiple open holes sized to resist leakage in the absence of suction, such as by the development of surface tension at the holes, and to allow flow when suction is applied. The holes are formed during molding of the lid.
U.S. Pat. No. 5,363,983 to Mary-Elizabeth Proshan teaches a cap for detachably closing a disposable container with liquid therein employs a flat horizontal disc having first and second openings disposed in spaced apart positions therein. The lid has a first opening that is a pinhole, and a second opening that is relatively large. The cap has a hollow vertical spout that tapers upwardly from the disc with an open lower end coincident with the second opening. The open upper of the spout is smaller in area than its lower end.
U.S. Pat. No. 6,610,339 to Michael J. Borgerson teaches a portable container for storing an edible liquid separate from an edible dry component, where the portable container houses a spoon. While the prior art addresses the mechanics of packaging utensils in a container, the prior art is largely centered on products used by adults, and the art is silent on a kit which enhances sanitation and reduces contamination. Sanitation and contamination are of preeminent importance in the care and feeding of children, as children are not innately endowed with knowledge of what can potentially make them sick, and, in general, because their immunological systems are less well developed than an adult's, they are more susceptible to becoming sick. Table 1 has a partial list of pathogens associated with foods and eating. What is needed is a sanitary, portable, feeding kit for children that not only provides the feeding utensils in a clean, compact disposable form, but also provides a protected sanitary zone for eating, and an apparatus to cover the child from spillage.
TABLE 1
Common Foodborne Pathogens
Pathogen
Infection Symptoms in Humans
Reservoir
Cause of Infection
Bacteria
Campylobacter
Fever, diarrhea, abdominal cramps,
Intestines of healthy
Eating undercooked chicken or foods
nausea, vomiting; Most commonly
birds; Raw poultry
contaminated with juices from
identified cause of diarrheal illness
meat, cattle and
undercooked chicken; In developing
in the world; May cause Guillain-
sometimes swine.
countries: unchlorinated drinking water
Barre syndrome.
supplies, e.g., wells, contaminated with
poultry feces.
Salmonella
Fever, diarrhea, abdominal cramps,
Intestines of birds,
Spread to humans by a variety of foods
headache.
reptiles and
of animal origin, e.g., undercooked
mammals.
poultry, contaminated eggs (eaten raw)
and raw milk; May invade the
bloodstream in persons of poor health
or weakened immune systems, causing
life-threatening infections.
E. coli O157:H7
Severe, bloody diarrhea, painful
Cattle and similar
Consuming food or water that has been
abdominal cramps; not much fever;
animals; also resides
contaminated with microscopic
May cause acute kidney failure,
in humans.
amounts of cow feces; Contaminated
hemolytic uremic syndrome, in
raw milk.
children.
Vibrio
Watery diarrhea, abdominal pain.
Estuarine and marine
Consuming raw, improperly cooked, or
parahaemolyticus
environment and fish
cooked, recontaminated fish and
and seafood from
shellfish.
those environments.
Viruses
Norwalk-like
Acute gastrointestinal illness,
Infected persons for
Contact with infected persons/food
virus
usually with more vomiting than
up to 2 days after
handlers.
diarrhea; Headache, myalgia and
diarrhea stops.
low-grade fever.
Hepatitis A
Infects the liver and causes
Feces of infected
Person-to-person fecal-oral route by
hepatitis A virus: fever, malaise,
people; Poor
infected food handlers.
nausea, abdominal discomfort, dark
sanitation and
urine and jaundice.
crowding facilitate
transmission.
Protozoa
Toxoplasma
No symptoms but possible diarrhea;
Found in virtually all
Consuming raw or undercooked meat
gondii
Infected pregnant women may pass
animal foods.
or contact with cats that shed cysts in
the disease to their fetuses,
their feces during acute infection.
resulting in death of the fetus or
severe health effects, such as
mental retardation.
Cryptosporidium
Profuse watery diarrhea; Life-
Waterborne or found
parvum
threatening among the
in animal manures.
immunocompromised.
SUMMARY OF THE INVENTION
In the broadest sense, the invention is a convenient, portable, โall-in-oneโ kit that can be easily transported and which contains all of the feeding accessories that a child would require for a meal, and also provides a sanitary environment for eating the meal. The kit is comprised of members, including a container member, which is a cup; and a closing member, which is a lid with a controlled-flow drinking spout. The cup, when fitted with the lid having a controlled-flow drinking spout, is commonly known as a sippy cup, where a sippy cup is refillable. The cup, capped with the lid, serves as an enclosure for the other members of the kit, as well as a drinking vessel. The kit is further comprised of a utensil member, such as a spoon or fork or both, that is a feeding utensil, which is sized so as to fit within the cup. All of the members of the kit are relatively inexpensive, so that the entire kit can be considered disposable after a single usage. None of the members of the kit are believed to present a choking hazard; however, the kit should only be used with adult supervision. The feeding utensil(s) is/are relatively flexible and have no sharp points or edges, and are believed to be safe; however, the kit should only be used with adult supervision. Substantially, each member of the kit is engineered so as to be appropriate for a supervised child, and to be contained within the interior of the cup. It is anticipated that members of the kit are not only functional, but are also engaging to the child. The cup is appropriately sized for a child under the age of about six years, and has a volume of 6-12 ounces, and more preferably 8-10 ounces. The cup, (i.e. container member), preferably is composed of plastic and has a rim with a rounded lip. The lid (i.e. closing member) is preferably composed of plastic and is a snap-on lid. The feeding utensil (i.e. utensil member) is preferably composed of plastic, and has a length, such that when enclosed in the cup and lid, the utensil is snuggly restrained at an angular orientation within cup against the lid. The kit is normally packaged for sale with the lid inverted, such that the drinking spout is protected inside the cup. The kit is further comprised of a packaging member, which is a plastic film such as shrink-wrap. The cup and the inverted lid and cup are substantially completely enclosed by the packaging member. The plastic film holds the lid on the cup and protects the contents from contamination. By packaging the kit with the lid inverted, the kit advantageously takes up less shelf room and is stackable.
The kit is further comprised of a protection member that provides a sanitary zone for eating the meal. The protection member is a specialized sheet that, when folded, fits within the interior of the lidded cup, and when unfolded provides an eating area free of contamination for placement of food and utensils. The specialized sheet is sized so that a protective contamination-free zone is created between the child's eating area and the supporting surface underneath it, which may be soiled or contaminated with pathogens or detritus. The specialized sheet is comprised of a material selected to have good lay flat (drape) properties after being unfolded. The flatness of the specialized sheet can be augmented with strips of double-sided pressure-sensitive adhesive tape. The double-sided pressure-sensitive adhesive tape is covered with a protective release liner. The tape is positioned along the edges of the backside of the specialized sheet, so that the specialized sheet can be smoothed flat and tensioned between the strips of tape. The specialized sheet can be printed, and if so, the printing is preferably reverse printed to ensure that no ink comes into contact with food or utensils or the child. The protection member works synergistically in concert with the other members of the kit to provide a sanitary zone for eating, even in areas that would otherwise present an unacceptable risk that the child may become sick from the ambient pathogens.
The kit is further comprised of a covering member that provides a barrier from spillage. In one embodiment the covering member is a disposable bib having an adjustable fastening means. The packaged bib is folded rectangularly so as to easily fit within the interior volume of the lidded cup. The bib is preferably comprised of a printed nonwoven material with a polymeric backside coating, such that only the front side of the bib is absorbent. The nonwoven material is selected such that it will unfold to a substantially flat material, where residual creasing is not sufficient to cause distortion of the bib. The adjustable fastening means is comprised of a sectional neck strap that is perforatedly attached, and a means for adhesively connecting the sections of the neck strap. One section of the neck strap has a pressure-sensitive double coated fastening tape protectively covered with a removable release liner, and the other section has a target tape attached to the front side of the bib. The neck strap is opened into sections by tearing along the perforations. The strap is adhered by peeling the release liner off the fastening tape, and pulling the strap and the bib around the wearer's neck until it is approximately chin high, and then adhering the fastening tape to the release side of the target tape. The strap can be adjusted by repositioning where the fastening tape adheres to the target tape, or the strap can be released by peeling the fastening tape off the target tape.
The kit can be further comprised of a cleaning member, such as a wipe, a napkin, Kleenex, a dental product, an antibacterial lotion, and soap. The kit can be further comprised of a resealing member, such as a resealable bag, and a cot for sealing the drinking spout.
The kit exists in substantially two states, either in the closed state or in the open state. In the closed state the contents are wrapped in the plastic film (i.e. packaging member), and the kit is portable. In the open state the plastic film is removed, the specialized sheet (i.e. protective member) is unfolded providing a substantially flat, contamination-free eating area, the refillable sippy cup (i.e. the container member capped with the closure member) is ready for filling with a liquid, the feeding utensils (i.e. the utensil members) are available for use, and the bib (i.e. the covering member) is available to be strapped around the child. If other members, such as the cleaning member and the resealing member, were in the kit, then they are available for use.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects will become readily apparent by referring to the following detailed description and the appended drawings in which:
FIG. 1 is an exploded view of the sippy cup comprised of a container member (cup) and a closure-member (lid);
FIG. 1 a is an overhead view of the closure member (a lid with tapered controlled-flow drinking spout);
FIG. 2 is a perspective elevational view of utensil members (a spoon and a fork);
FIG. 3 is a perspective side view of the fork;
FIG. 4 is a perspective view of the sippy cup;
FIG. 4 a is a perspective view of the cup containing all the members, folded, and packed in the interior of cup;
FIG. 5 a is a frontal view of the covering member (bib) with the strap perforatedly attached;
FIG. 5 b is a rear view of the bib with the strap perforatedly attached;
FIG. 5 c is a front view of the bib with the strap adhesively attached;
FIG. 5 d is a front view of the bib with the strap detached;
FIG. 6 a is a plan view of the front of the protective member (specialized sheet);
FIG. 6 b is a plan view of the rear of the protective member (specialized sheet);
FIG. 6 c is an exploded view of the double-sided tape shown in FIG. 6 b , wherein the release liner has been partially pulled away;
FIG. 7 is a side view of a closed kit, illustrating the container member (cup) and the closing member (inverted lid) enclosed in the packaging member (plastic film); the folded covering member (bib), the folded protective member (specialized sheet), and the utensil members (spoon and fork) are enclosed within the container member (cup) and the closing member (inverted lid);
FIG. 8 is an elevational perspective view of an open kit, illustrating a substantially flat protective member (specialized sheet) adhered to an underlying surface, and resting on the front of the protective member is a fork and a spoon, a sippy cup partially filled with a liquid, a cleaning member (wipe), a resealing member (resealable bag), and a covering member (bib). Not shown is the packaging film, which has been disposed of when removed. The specialized sheet provides a sanitary zone for eating the meal.
DETAILED DESCRIPTION
The invention is a sanitary, portable, feeding kit 10 for children. In a prepackaged compact form the kit 10 provides a drinking cup 22 and feeding utensils 40 all in a clean, compact disposable form. The kit further includes accoutrements for providing a protected sanitary area for eating, a bib, and, optionally, cleaning and resealing supplies. As illustrated in FIG. 1 , a sippy cup 20 is comprised of a cup 12 and a lid 22 with a controlled-flow drinking spout 24 . The cup 12 , which as a member of the kit, is generically referred to as a container member 12 , and the lid is a referred to as a closing member 22 . The cup is plastic, and has a rim 14 with a rounded lip. The lid 22 , which snaps on the rim 12 of the cup, has a circular ridge 32 and a finger tab 32 for removing the lid. The drinking spout 24 , which projects from the plane of the lid, is tapered, and as can be seen in FIG. 1 a , has a single opening 26 which restricts the rate of flow of liquid exiting the sippy cup 20 . The tapered drinking spout 24 enables drinking to be effected using a combination of sucking and taking small sips. The sip size is generally restricted to the size of a well 28 formed in the spout. This combination of cup 12 and lid 22 is well known as a sippy cup 20 . The single outlet hole 26 is advantageous, as air is substantially occluded while drinking, and after several swallows the flow slows until the sippy cup 20 is turned upright and ambient air can reenter the sippy cup clearing the outlet hole 26 . The single hole minimizes spillage, while at the same time teaches the user to take small sips. Only a small amount of the liquid in the sippy cup 20 will seep out if the sippy cup 20 is turned over. The sippy cup 20 with the lid snapped on is illustrated in FIG. 4 . As can be seen in FIG. 1 a , the outlet 26 is located in the bottom of the well 28 .
The kit 10 is further comprised of a utensil member 40 , as shown in FIG. 2 . The utensil member 40 is preferably two members, a spoon 42 and fork 44 . The stem 46 of the utensil 40 is preferably slightly curved, both lengthwise and crosswise, as shown in FIG. 3 . The crosswise arc creates what in effect is a ridge, so that when the stem 46 is stressed, it is in a compressed state, which imparts additional strength to the utensil 40 . The gripping end 48 of the utensil's stem, sometimes called the bit, is widened so as to ergonomically enhance the ease of gripping, therein making it easier to access the bottom of the cup or another relatively deep container for food without extending one's fingers much beyond the rim. The ergonomic grip 48 prevents probable contact between the fingers and the food, and the probable coincidental contamination of the food and the user's hand. The widened gripping end 48 of the stem 46 is also preferably decorous with a final 49 , wherein the final 49 is an imprinted or embossed design area.
The kit is further comprised of a protection member 50 , as shown in FIGS. 6 a , 6 b and 6 c , which provides a sanitary zone for eating the meal. The protection member 50 is comprised of a sheet of material 51 , such as a flexible plastic film that, when folded, fits within the interior of the lidded cup 12 , as shown in FIG. 4 a , that when unfolded provides an eating area free of contamination for placement of food and utensils. The specialized sheet 50 is sized so that the front side 52 of the protection member 50 is a protective contamination-free zone between the child's eating area and the supporting surface underneath it, which may be soiled or contaminated with pathogens or detritus. Examples of supporting surfaces are tables, highchairs, trays, and the ground. The sheet material 51 has good, lay flat (drape) properties after being unfolded. The front 52 of sheet, as shown in FIG. 6 a and FIG. 8 , has a kid's entertainment center 54 . The center 54 can for instance have a picture of their favorite characters, instructional information, or outlines for their dinnerware. FIG. 6 b is planar view of the back 56 of the protective member 50 . The edges are framed with strips of a double-sided pressure-sensitive tape 58 , which is covered with a release liner 60 . As shown in FIG. 6 c , the adhesive 62 is exposed upon removal of the release liner 60 . The tape 58 ensures that the protective member is flat, and difficult for the child to lift up, therein providing a sanitary zone for eating, even in areas that would be otherwise present an unacceptable risk that the child may become sick from the ambient pathogens. As illustrated, the protective member, which is a clear plastic, is reverse-printed to ensure that no ink comes into contact with food or utensils 40 or the child 1 .
The kit is further comprised of a covering member 80 , which is illustrated in FIGS. 5 a - 5 d . The covering member, which is a disposable bib 80 , provides a barrier from spillage. The disposable bib 80 has an adjustable fastening means that is a repositionable adhesiveโtarget system. The target tape 84 enables the adhering tape 92 to be adhered, and released, multiple times without delaminating the bib material. The bib, packaged in the cup of the unopened kit, is folded rectangularly so as to easily fit within the interior volume 16 of the cup 12 . The bib 50 is composed of a printed nonwoven material with a polymeric coating on the backside 97 , where the front side 95 of the bib is absorbent, whereas the back 97 of the bib is not. The nonwoven material is selected such that it unfolds to a substantially flat material, where residual creasing does cause distortion of the bib 80 . The neck portion of the bib has a sectional neck strap 82 that is perforatedly attached, so that the sectional neck strap can be easily separated, where upon separation there is first section 84 and a second section 86 . The perforations 104 divide the first 84 and second 86 sections. As illustrated, the front 95 of the bib has the target tape 8 on the first section 84 of the strap 82 , as shown in FIG. 5 a . The backside 97 , as shown in FIG. 5 b , of the bib 80 has a double-sided adhesive tape 92 on the second section 84 . The double-sided adhesive fastening tape 92 is covered with a release liner 94 . The strap 82 is adhered by peeling the release liner 94 off the fastening tape 92 , and pulling the strap 82 and the bib around the child's neck until it is approximately chin high, and then adhering the fastening tape 92 to the release side of the target tape 88 , as shown in FIG. 5 d . The strap 82 can be adjusted by repositioning where the fastening tape 92 adheres to the target tape 88 , or the strap 82 can be released by peeling the fastening tape 92 off the target tape 88 , as shown in FIG. 5 c . The bottom portion 100 of the bib has an inverted crumb catcher 98 . Prior to forming the inverted crumb catcher, the crumb catcher is a sealed pocket 96 on the backside 97 of the bib 80 . When sealed pocket 96 is inverted, the inverted seals cause the pocket to flare, therein creating a crumb catcher 98 on the front of the bib. FIG. 5 b illustrates the sealed pocket 96 prior to inverting, and FIG. 5 d illustrates the crumb catcher 98 after the sealed pocket 96 has been inverted.
The kit 10 , prior to being opened, is illustrated in FIG. 7 . As is apparent, the lid 22 is inverted so that the feeding spout 24 is in the interior 16 of the cup 12 . The lid 22 and cup 12 are completely enclosed by a packing member 110 , which is a plastic film. The plastic film holds the lid 22 in place. As can be seen in FIG. 4 a , where the packing member 110 and the lid 22 are removed, the other members are enclosed in the cup 12 . The bib 80 and the specialized sheet 50 are folded and inserted in the cup 12 , along with two utensil members 40 . The utensil members 40 , when angled, are near the rim 14 of the cup 12 . The length of the utensil members 40 is sized so that they can suitably fit inside the cup 12 . As shown, the cup is 9-10 ounces in volume.
FIG. 8 illustrates the kit 10 after it has been opened, and is being used. The packaging member 110 has been removed, liquid has been added to the sippy cup 20 , and the lid 22 is snapped on. The protective member 50 has been unfolded, and adhered to the table where the child 1 is eating. The covering member 80 has been unfolded, separated along the perforations, the sealed pocket 96 has been inverted forming the inverted crumb catcher 98 , and the sections of the strap 82 are adhesively fastened around the child's neck. The plastic utensil members 40 are set out on the protective member 50 . Two other members of the kit have been added, and are at ready. There is a cleaning member 300 which is a wipe, and a resealing member 200 which is a resealable plastic bag. The characters on the child's printed bib match the characters on the entertainment center 54 reverse-printed on the backside 56 of the protective member 50 . Even the ergonomic grips 48 on the spoon 42 and fork 44 have characters embossed and outlined on the finals 49 . After the meal, the bib 80 can be removed and stacked on the protective member 50 , and the entire kit can be disposed. Alternatively, if the child is still drinking, or will want to drink later, everything but the sippy cup 20 can be disposed, and the sippy cup 20 can continue to be used.
The descriptions above and the accompanying drawings should be interpreted in the illustrative and not the limited sense. While the invention has been disclosed in connection with the preferred embodiment or embodiments thereof, it should be understood that there may be other embodiments which fall within the scope of the invention as defined by the following claims. Where a claim is expressed as a means or step for performing a specified function, it is intended that such claim be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof, including both structural equivalents and equivalent structures.
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A convenient, portable, โall-in-oneโ kit that contains all of the feeding accessories that a child would require for a meal, and also provides a sanitary environment for eating the meal. The kit is comprised of members including a container member, which is a cup; and closing member, which is a lid with a controlled-flow drinking spout. The cup fitted with the lid is commonly known as a sippy cup. The lidded cup serves as an enclosure for the other members of the kit. The kit also includes a utensil member, such as a spoon or fork or both. The entire kit is inexpensive and therefore disposable after a single usage. A unique feature about the kit is the inclusion of a protective member that is a specialized sheet that can be adhesively fastened to a table or highchair and, as such, provides a sanitary zone for eating the meal.
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BACKGROUND
[0001] 1. Field of Invention
[0002] The present invention is directed to methods of preparing a cased wellbore for stimulation operations and, in particular, to interventionless methods for preparing the cased wellbore for stimulation operations using pressure actuated sleeves and apparatuses for temporarily restricting fluid flow through the wellbore casing to prepare the wellbore casing for stimulation operations as opposed to using additional wellbore intervention methods such as tubing conveyed perforation.
[0003] 2. Description of Art
[0004] Ball seats are generally known in the art. For example, typical ball seats have a bore or passageway that is restricted by a seat. The ball or plug element is disposed on the seat, preventing or restricting fluid from flowing through the bore of the ball seat and, thus, isolating the tubing or conduit section in which the ball seat is disposed. As force is applied to the ball or plug element, the conduit can be pressurized for tubing testing or tool actuation or manipulation, such as in setting a packer. Ball seats are used in cased hole completions, liner hangers, flow diverters, fracturing systems, acid-stimulation systems, and flow control equipment and other systems.
[0005] Although the terms โball seatโ and โballโ are used herein, it is to be understood that a drop plug or other shaped plugging device or element may be used with the โball seatsโ disclosed and discussed herein. For simplicity it is to be understood that the terms โballโ and โplug elementโ include and encompass all shapes and sizes of plugs, balls, darts, or drop plugs unless the specific shape or design of the โballโ is expressly discussed.
[0006] Stimulating, which as used herein includes fracturing or โfracing,โ a wellbore using stimulation systems or tools also are known in the art. In general, stimulating systems or tools are used in oil and gas wells for completing and increasing the production rate from the well. In deviated wellbores, particularly those having longer lengths, fluid, such as acid or fracturing fluids, can be expected to be introduced into the linear, or horizontal, end portion of the well to stimulate the production zone to open up production fissures and pores there-through. For example, hydraulic fracturing is a method of using pump rate and hydraulic pressure created by fracturing fluids to fracture or crack a subterranean formation, or the wellbore environment.
[0007] Prior to stimulating a wellbore, a stimulation tool is cemented into the wellbore. Thereafter, a pressure test of the wellbore casing containing the stimulation tool is performed. To perform this step, the pathway through the stimulation tool must be closed off. After the casing test establishes the integrity of the wellbore casing, fluid communication of the pathway through the stimulation tool is reestablished so that the stimulation fluid can be pumped down through the stimulation tool and into the formation. Currently, the steps involved in reestablishing fluid flow through the stimulation tool require additional wellbore intervention such as by using tubing conveyed perforation.
SUMMARY OF INVENTION
[0008] Broadly, the methods for preparing a wellbore for stimulation operations disclosed herein comprise the steps of cementing into a wellbore casing a downhole tool comprising a valve having an apparatus for restricting fluid flow through the valve, such as a ball seat, disposed above the valve. The valve is actuated to its opened position to establish fluid flow between the casing bore and the formation or wellbore environment. Thereafter, a plug element is disposed on the seat of the ball seat and a casing pressure test is performed. The plug element then dissolves or disintegrates over time thereby increasing fluid communication between the formation and the wellbore casing through the valve, thereby placing the wellbore casing in condition for stimulation operations without additional wellbore intervention after the casing test.
[0009] In one specific embodiment, the plug element also functions as a wiper member to facilitate additional clean-up of the bore of the valve after the pressure test has been performed. The plug element dissolves into a predetermined shape that, when pushed through the seat and the bore of the valve, the plug element wipes away debris within the bore of the valve.
BRIEF DESCRIPTION OF DRAWINGS
[0010] FIG. 1 is a cross-sectional view of one specific embodiment of the downhole tool disclosed herein showing an exemplary valve in its closed position.
[0011] FIG. 2 is a cross-sectional view of the downhole tool of FIG. 1 showing the valve in one of its opened positions.
[0012] FIG. 3 is a cross-sectional view of the downhole tool of FIG. 1 showing a plug element landed on a seat above the valve so that a casing test can be performed.
[0013] FIG. 4 is a cross-sectional view of the downhole tool of FIG. 1 showing the downhole tool in position for stimulation operations after the pressure test has been performed and the plug element shown in FIG. 3 dissolved.
[0014] FIG. 5 is a cross-sectional view of a specific embodiment of a plug element as disclosed herein.
[0015] FIG. 6 is a side view of the wiper member shown in FIG. 5 .
[0016] While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0017] Referring now to FIGS. 1-4 , in one specific embodiment, downhole tool 30 comprises valve 40 and bore restriction apparatus 70 , shown as a ball seat in FIGS. 1-4 . FIG. 1 shows valve 40 in a closed position, and FIGS. 2-4 show valve 40 actuated to an open position.
[0018] Valve 40 includes lower ported housing 44 having fluid communication ports 46 , and upper body 48 . Pressure integrity of valve 40 is maintained by body seals 41 . Body set screws 47 keep the body connection threads 43 from backing out during installation. Captured between lower ported housing 44 and upper body 48 is inner shifting sleeve 50 . Inner shifting sleeve 50 has several diameters that create piston areas that generate shifting forces to open valve 40 . Port isolation seals 45 located on the lower end of inner shifting sleeve 50 and lower internal bore piston seals 65 above fluid communication ports 46 both act to isolate the inside of valve 40 during and after cementation. Port isolation seals 45 and lower internal bore piston seals 65 operate within their respective polished bores 55 , 57 within lower ported housing 44 . The larger intermediate internal bore piston seals 52 are used to drive up inner shifting sleeve 50 along the upper internal polished bore 53 within lower ported housing 44 after burst disc 42 is ruptured.
[0019] Upper external rod piston seals 59 located within upper body 48 act to prevent cement from entering upper atmospheric chamber 62 and wipe the outside diameter of upper sleeve polished bore 61 during opening of valve 40 . Inner shifting sleeve 50 also has shoulder 54 that shears shear screw 56 during the opening shift of inner shifting sleeve 50 . External sleeve lock ring retention groove 63 is located between internal bore seals 52 and upper sleeve polished bore 61 diameter. Lock ring retention groove 63 accepts sleeve lock ring 69 that is retained by lock ring retainer 67 after valve 40 has been fully opened. Thus, sleeve lock ring 69 prevents inner shifting sleeve 50 from closing after valve 40 has been opened ( FIGS. 2-4 ).
[0020] Located between lower internal bore piston seals 65 and intermediate bore piston seals 52 is lower atmospheric chamber 58 which contains air that can be independently tested through lower pressure test port 60 . Located between intermediate internal bore piston seals 52 and upper external rod piston seals 59 is upper atmospheric chamber 62 which also contains air that can be independently tested through upper pressure testing port 64 . A rupture or burst disc 42 is held in place within a port located on the outside of inner shifting sleeve 50 by load ring 66 and load nut 68 . Burst disc load nut 68 is sized to allow significant torque and load to be transferred into burst disc 42 prior to installation of inner shifting sleeve 50 within valve 40 .
[0021] Those skilled in the art will appreciate that the use of the rupture disc for piston access is simply the preferred way and generally more accurate than relying exclusively on shearing a shear pin. A pressure regulation valve can also be used for such selective access as well as a chemically responsive barrier that goes away in the presence of a predetermined substance or energy field, temperature downhole or other well condition for example, to move the sleeve. Burst or rupture discs 42 also can be replaced by any other pressure control plug known in the art such as those disclosed and taught in U.S. patent application Ser. No. 13/286,775, filed Nov. 1, 2011, entitled โFrangible Pressure Control Plug, Actuatable Tool, Including Plug, and Method Thereofโ which is hereby incorporated by reference in its entirety.
[0022] After burst disc 42 is ruptured, lower chamber 58 is under absolute downhole pressure so wall flexure at that location is minimized. Even before burst disc 42 breaks, the size of lower chamber 58 is sufficiently small to avoid sleeve wall flexing in that region. The use of a large boss to support intermediate internal bore piston seals 52 also strengthens inner shifting sleeve 50 immediately below upper chamber 62 , thus at least reducing flexing or bending that could put inner shifting sleeve 50 in a bind before it is fully shifted. The slightly larger dimension of external rod piston seals 59 as compared to port isolation seals 45 that hold inner shifting sleeve 50 closed initially also allows a greater wall thickness for inner shifting sleeve 50 near the upper chamber 62 to further at least reducing flexing or bending to allow inner shifting sleeve 50 to fully shift without getting into a bind.
[0023] The intermediate internal bore piston seals 52 can be integral to inner shifting sleeve 50 or a separate structure. Upper chamber 62 has an initial pressure of atmospheric or a predetermined value less than the anticipated hydrostatic pressure within inner shifting sleeve 50 . The volume of upper chamber 62 decreases and its internal pressure rises as inner shifting sleeve 50 moves to open ports 46 .
[0024] Ball seat 70 is secured to the upper end of valve 40 through any known device or method in the art, such as a threaded connection. Ball seat 70 comprises upper end 71 , lower end 72 which is secured to valve 40 , and inner wall surface 73 defining bore 74 . Seat 75 is disposed along inner wall surface 73 for receiving a plug element such as ball 80 shown in FIG. 3 .
[0025] In operation, downhole tool 30 is connected to casing at its upper and lower ends and run in open-hole cementable completions just above float equipment. After being disposed within the wellbore at the desired location, downhole tool 30 is cemented into place within the well.
[0026] After cementation, a clean-out operation is performed to remove debris from the flow path through valve 40 . The clean-out operation can be performed by pumping fluid through downhole tool 30 to clean up any debris remaining from the cementing operations. In addition, or alternatively, a wiper plug can be transported down the bore of the casing, past seat 75 to and through the bore of valve 40 to wipe away and debris, including residual cement.
[0027] After the cement has set on the outside of valve 40 , it is ready to be opened with a combination of high hydrostatic and applied pressure. Upon reaching the critical pressure, burst disc 42 is fractured and opens lower atmospheric chamber 58 to the absolute downhole pressure. This pressure acts on the piston area created by lower internal bore piston seals 65 and the larger internal bore piston seals 52 and drives inner shifting sleeve 50 upward compressing the air within upper atmospheric chamber 62 and opening fluid communication ports 46 on the ported housing 44 . Thus, the volume of upper chamber 62 decreases and its internal pressure rises as inner shifting sleeve 50 moves to open ports 46 .
[0028] After inner shifting sleeve 50 is completely shifted and in contact with the downward facing shoulder on lock ring retainer 67 , sleeve lock ring 69 falls into sleeve lock retention groove 63 on inner shifting sleeve 50 preventing valve 40 from subsequently closing.
[0029] After burst disc 42 is fractured, absolute downhole pressure acts on piston seals 52 and piston seals 65 continuously pushing sleeve 50 upward acting as a redundant locking feature preventing valve 40 from subsequently closing.
[0030] Upon opening valve 40 , fluid communication between the bore of downhole tool 30 and, thus, the wellbore casing string, and the wellbore formation or wellbore environment is established. Thereafter, a pressure test of the casing can be performed. To do so, plug element 80 is transported down the casing string and landed on seat 75 of ball seat 70 ( FIG. 3 ). Afterwards, a pressure test is performed. Presuming the pressure test is successful, then the wellbore is capable of having stimulation operations performed. However, the plug element 80 remains on seat 75 . Plug element 80 is removed from seat 75 over time due to the dissolution of at least a portion of plug element 80 . After plug element 80 sufficiently dissolves such that fluid pressure acting downward on plug element 80 can push plug element 80 through seat 75 and through the bore of valve 40 , fluid communication between the casing string and the formation is increased so that stimulation operations can be performed. Thus, after landing plug element 80 on seat 75 and the pressure test is performed, no additional wellbore intervention is required to place the casing string in condition for stimulation operations.
[0031] In certain embodiments, plug element 80 completely dissolves. In other embodiments, plug element 80 partially dissolves before passing through seat 75 and through the bore of valve 40 . In still other embodiments, a portion of plug element 80 is formed from a material that is not dissolvable. Dissolution of a portion, or all of plug element 80 , can be accomplished by having plug element 80 formed at least in part by a dissolvable material. โDissolvableโ means that the material is capable of dissolution in a fluid or solvent disposed within the wellbore casing. โDissolvableโ is understood to encompass the terms degradable and disintegrable. Likewise, the terms โdissolvedโ and โdissolutionโ also are interpreted to include โdegradedโ and โdisintegrated,โ and โdegradationโ and โdisintegration,โ respectively. The dissolvable material may be any material known to persons of ordinary skill in the art that can be dissolved, degraded, or disintegrated over an amount of time by a temperature or fluid such as water-based drilling fluids, hydrocarbon-based drilling fluids, or natural gas, and that can be calibrated such that the amount of time necessary for the dissolvable material to dissolve is known or easily determinable without undue experimentation. Suitable dissolvable materials include controlled electrolytic metallic nano-structured materials such as those disclosed in U.S. patent application Ser. No. 12/633,682, filed Dec. 8, 2009 (U.S. Patent Publication No. 2011/0132143), U.S. patent application Ser. No. 12/633,686, filed Dec. 8, 2009 (U.S. Patent Publication No. 2011/0135953), U.S. patent application Ser. No. 12/633,678, filed Dec. 8, 2009 (U.S. Patent Publication No. 2011/0136707), U.S. patent application Ser. No. 12/633,683, filed Dec. 8, 2009 (U.S. Patent Publication No. 2011/0132612), U.S. patent application Ser. No. 12/633,668, filed Dec. 8, 2009 (U.S. Patent Publication No. 2011/0132620), U.S. patent application Ser. No. 12/633,677, filed Dec. 8, 2009 (U.S. Patent Publication No. 2011/0132621), and U.S. patent application Ser. No. 12/633,662, filed Dec. 8, 2009 (U.S. Patent Publication No. 2011/0132619), all of which are hereby incorporated by reference in their entirety.
[0032] Additional suitable dissolvable materials include polymers and biodegradable polymers, for example, polyvinyl-alcohol based polymers such as the polymer HYDROCENEโข available from Idroplax, S.r.l. located in Altopascia, Italy, polylactide (โPLAโ) polymer 4060D from Nature-Worksโข, a division of Cargill Dow LLC; TLF-6267 polyglycolic acid (โPGAโ) from DuPont Specialty Chemicals; polycaprolactams and mixtures of PLA and PGA; solid acids, such as sulfamic acid, trichloroacetic acid, and citric acid, held together with a wax or other suitable binder material; polyethylene homopolymers and paraffin waxes; polyalkylene oxides, such as polyethylene oxides, and polyalkylene glycols, such as polyethylene glycols. These polymers may be preferred in water-based drilling fluids because they are slowly soluble in water.
[0033] In calibrating the rate of dissolution of dissolvable material 40, generally the rate is dependent on the molecular weight of the polymers. Acceptable dissolution rates can be achieved with a molecular weight range of 100,000 to 7,000,000. Thus, dissolution rates for a temperature range of 50ยฐ C. to 250ยฐ C. can be designed with the appropriate molecular weight or mixture of molecular weights.
[0034] Referring now to FIGS. 5-6 , in an alternative embodiment, plug element 180 comprises an initial shape ( FIG. 5 ) that is capable of landing on seat 75 to restrict fluid flow through seat 75 , and a new or second shape ( FIG. 6 ) that is sufficient to act as a wiper member as it passes through seat 75 and/or through the bore of valve 40 and/or the bore of inner shifting sleeve 50 upon partial or complete dissolution of the dissolvable material 181 of plug element 180 . In this embodiment, plug element 180 includes wiper member 190 encapsulated by dissolvable material 181 . Wiper member 190 can be formed out of a material 191 that can be a non-dissolvable material or a second dissolvable material that dissolves at a slower rate compared to dissolvable material 181 . Upon sufficient dissolution of dissolvable material 181 , wiper member 190 is capable of being pushed through seat 75 and/or through the bore of valve 40 and/or the bore of inner shifting sleeve 50 . In so doing, wiper member 190 wipes or cleans away debris disposed along these surfaces. Thus, a mechanical clean-out of the valve can be performed after the pressure test without additional wellbore intervention.
[0035] As discussed above, plug elements 80 , 180 can be formed completely out of one or more dissolvable materials or plug elements 80 , 180 can be formed partially out of one or more dissolvable materials. In the former embodiment, plug elements 80 , 180 will completely dissolve and fluid flow through valve 40 in the wellbore environment will be increased. In the latter embodiment, upon dissolution, plug elements 80 , 180 can have a new or second shape that is different from the initial shape of plug element 80 that provided restriction of fluid flow through seat 75 . The new shape of plug element 80 can either fall through valve 40 as debris, or it can facilitate wiping or cleaning of the bore of valve 40 by the remaining portion(s) of plug elements 80 , 180 . Thus, plug elements 80 , 180 can remove debris disposed within the valve bore as fluid communication between the wellbore casing and the wellbore environment is increased. In these embodiments, both increase of fluid communication between the wellbore casing and the wellbore environment after removal of plug elements 80 , 180 , and mechanical clean-out of the valve bore, occur without further wellbore intervention.
[0036] It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, the wiper member can have any shape desired or necessary to pass through the valve to remove debris disposed within the bore of the valve and/or inner shifting sleeve. In addition, the wiper can be formed out of a non-dissolvable material or another dissolvable material. Moreover, the valve is not required to have the structures disclosed herein, nor is the valve required to operate as disclosed herein. Further, the ball seats disclosed herein can be modified as desired or necessary to restrict fluid flow through the wellbore casing. Additionally, dissolvable materials not disclosed herein can be used in place of those that are disclosed herein. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.
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Methods for preparing a wellbore casing for stimulation operations comprise the steps of cementing a wellbore casing in a wellbore, the wellbore casing having a downhole tool comprising a valve and an apparatus for restricting fluid flow through the valve, such as a ball seat, disposed above the valve. Actuation of the valve opens the valve to establish fluid communication between the wellbore casing and the formation. A plug element is disposed on a seat of the ball seat and a casing pressure test is performed. The plug element then dissolves or disintegrates over time increasing fluid communication between the wellbore casing and the formation, thereby preparing the wellbore casing for stimulation operations without additional wellbore intervention after the casing pressure test. In certain embodiments, during or after dissolution of the plug element, clean-out of the bore of the valve is performed by the plug element.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to and is a continuation of U.S. patent application Ser. No. 12/391,101 filed Feb. 23, 2009 issued as U.S. Pat. No. 7,877,174 on Jan. 25, 2011, which is a continuation-in-part of U.S. patent application Ser. No. 11/903,208 filed Sep. 19, 2007, which claims priority and incorporates herein by reference U.S. patent application Ser. No. 11/811,617 filed on Jun. 11, 2007 issued as U.S. Pat. No. 7,494,394 on Feb. 24, 2009; U.S. patent application Ser. No. 11/811,604 filed on Jun. 11, 2007 issued as U.S. Pat. No. 7,465,203 on Dec. 16, 2008; U.S. patent application Ser. No. 11/811,606 filed on Jun. 11, 2007 issued as U.S. Pat. No. 7,485,021 on Feb. 3, 2009; U.S. patent application Ser. No. 11/811,605 filed on Jun. 11, 2007 issued as U.S. Pat. No. 7,491,104 on Feb. 17, 2009; U.S. patent application Ser. No. 11/811,616 filed Jun. 11, 2007, issued as U.S. Pat. No. 7,494,393 on Feb. 24, 2009, which claim priority to and are continuation-in-part applications of U.S. patent application Ser. No. 11/056,848 filed Feb. 11, 2005, issued as U.S. Pat. No. 7,229,330 on Jun. 12, 2007, which claims priority to U.S. Provisional Patent Application Ser. No. 60/543,610 filed Feb. 11, 2004.
FIELD OF THE INVENTION
The present invention pertains to the field of water sports and boating.
BACKGROUND OF THE INVENTION
Competitors in trick, jump, and slalom ski and wakeboard events require tow boats capable of consistent and accurate speed control. Intricate freestyle tricks, jumps, and successful completion of slalom runs require passes through a competition water course at precisely the same speed at which the events were practiced by the competitors. Some events require that a pass through a course be made at a specified speed. Such requirements are made difficult by the fact that typical watercraft Pitot tube and paddle wheel speedometers are inaccurate and measure speed over water instead of speed over land, and wind, wave, and skier loading conditions constantly vary throughout a competition pass.
Marine transportation in general suffers from the lack of accurate vessel speed control. The schedules of ocean-going vessels for which exact arrival times are required, for example, are vulnerable to the vagaries of wind, waves, and changing hull displacement due to fuel depletion.
SUMMARY OF THE INVENTION
The present invention provides consistent, accurate control of watercraft speed over land. It utilizes velocity measuring device and an inertia based measurement device technology to precisely monitor watercraft velocity over land. It utilizes dynamic monitoring and dynamic updating of engine control data in order to be responsive to real-time conditions such as wind, waves, and loading.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram of an embodiment of the present invention.
FIG. 2 is a flow chart of the steady state timer algorithm used in the embodiment.
FIG. 3 is a schematic of a watercraft utilizing an embodiment of the present invention.
FIG. 4 is a graphical representation of the engine speed and boat speed data shown in the tables herein.
FIG. 5 is a flow diagram of an alternate embodiment of the present invention.
FIG. 6 is a flow diagram of another embodiment of the present invention.
FIG. 7 is a flow diagram of an alternate embodiment of the present invention.
FIG. 8 is a flow diagram of another embodiment of the present invention.
FIG. 9 is a flow diagram of another embodiment of the present invention.
FIG. 10 is a flow diagram of an alternate embodiment of the present invention.
FIG. 11 is a flow diagram of another embodiment of the present invention.
FIG. 12 is a flow diagram of an alternate embodiment of the present invention.
FIG. 13 is a flow diagram of another embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The present invention is an electronic closed-loop feedback system that controls the actual angular velocity ฯ a of a boat propeller, and, indirectly, the actual over land velocity v a of the watercraft propelled by that propeller. The system has various configurations with one embodiment including a velocity measuring device, an inertia-based measuring device, at least two conversion algorithms, and engine speed controls. Other configurations include a global positioning satellite (GPS) velocity measurement device, a marine engine speed tachometer, comparators, conversion algorithms, and engine speed controls.
Herein, a GPS device is one of the category of commonly understood instruments that use satellites to determine the substantially precise global position and velocity of an object. Such position and velocity measurements can be used in conjunction with timers to determine an object's instantaneous velocity and average velocity between two points. A velocity measuring device is one of a category of commonly understood instruments that is capable of measuring the velocity of an object for example, a GPS device, a paddle wheel, or a pitot tube. An inertia based measurement device is one of a category of commonly understood instruments that is capable of measuring the acceleration of an object. The velocity of an object can be calculated by integrating the acceleration of an object over time. Engine speed refers to angular velocity, generally measured with a device herein referred to as a tachometer. A comparator is any analog or digital electrical, electronic, mechanical, hydraulic, or fluidic device capable of determining the sum of or difference between two input parameters, or the value of an input relative to a predetermined standard. An algorithm is any analog or digital electrical, electronic, mechanical, hydraulic, or fluidic device capable of performing a computational process. The algorithms disclosed herein can be performed on any number of devices commonly called microprocessors or microcontrollers, examples of which include the Motorolaยฎ MPC555 and the Texas Instrumentsยฎ TMS320.
As diagrammed in FIG. 1 showing feedback system 100 , GPS device 10 measures the actual velocity v a of a watercraft 50 . The GPS output v GPS is compared in first comparator 12 to predetermined velocity v d . Comparator 12 output velocity error ฮต v is input to an algorithm 14 that converts ฮต v to engine speed correction ฯ c that is input to a second comparator 16 . Predetermined velocity v d is input to an algorithm 18 the output of which is ฯ adapt , a value of engine speed adaptively determined to be the engine speed necessary to propel watercraft 50 at predetermined velocity v d under the prevailing conditions of wind, waves, and watercraft loading, trim angle, and attitude.
The addition of engine speed correction ฯ c and engine speed ฯ adapt in comparator 16 results in the total desired engine speed ฯ d that is input to a third comparator 20 . A sensor 24 , one of many types of commonly understood tachometers, detects the actual angular velocity ฯ a of a driveshaft from an engine 53 of watercraft 50 and sends it to third comparator 20 . In comparator 20 actual angular velocity ฯ a and total desired engine speed ฯ d are compared for engine speed error ฮต ฯ that is input to an algorithm 26 . In the algorithm 26 engine speed error ฮต ฯ is converted into engine torque correction ฯ c .
Total desired engine speed ฯ d is also input to an algorithm 22 the output of which is ฯ adapt , a value of engine torque adaptively determined to be the engine torque necessary to operate watercraft engine 53 at total desired engine speed ฯ d . The addition of engine torque ฯ adapt and engine torque correction ฯ c in a fourth comparator 28 results in the calculated desired engine torque ฯ d . Calculated desired engine torque ฯ d is input to controller 30 that drives a throttle control capable of producing in engine 53 a torque substantially equal to calculated desired engine torque ฯ d .
The algorithms 14 and 26 , respectively, could include any common or advanced control loop transfer function including, but not limited to, series, parallel, ideal, interacting, noninteracting, analog, classical, and Laplace types. For both the algorithms 14 and 26 the embodiment utilizes a simple proportional-integral-derivative (PID) algorithm of the following type (exemplified by the algorithm 14 transfer function):
ฯ c =K p ฮต v +K d ( d/dt )ฮต v +โซK i ฮต v dt.
Where K p , K d , and K i are, respectively, the appropriate proportional, derivative, and integral gains.
The algorithms 18 and 22 , respectively, provide dynamically adaptive mapping between an input and an output. Such mapping can be described as self-modifying. The inputs to the algorithms 18 and 22 are, respectively, predetermined velocity v d and total desired engine speed ฯ d . The outputs of the algorithms 18 and 22 are, respectively, engine speed ฯ adapt and engine torque ฯ adapt . The self-modifying correlations of algorithms 18 and 22 may be programmed during replicated calibration operations of a watercraft through a range of velocities in a desired set of ambient conditions including, but not limited to, wind, waves, and watercraft loading, trim angle, and attitude. Data triplets of watercraft velocity, engine speed, and engine torque are monitored with GPS technology and other commonly understood devices and fed to algorithms 18 and 22 during the calibration operations. Thereafter, a substantially instantaneous estimate of the engine speed required to obtain a desired watercraft velocity and a substantially instantaneous estimate of the engine torque required to obtain a desired engine speed can be fed to the engine speed and torque control loops, even in the absence of watercraft velocity or engine speed departures from desired values, in which cases the outputs of algorithms 14 and 26 may be zero.
In the embodiment shown in FIG. 1 , no adaptive data point of watercraft velocity, engine speed, or engine torque described above is programmed into algorithms 18 or 22 until it has attained a steady state condition as diagrammed in FIG. 2 . A timer compares watercraft velocity error ฮต v , engine speed error ฮต ฯ , the time rate of change of actual watercraft velocity v a , and the time rate of change of actual engine speed ฯ a to predetermined tolerance values. When the absolute value of each variable is less than or equal to its predetermined tolerance, and the time elapsed since the beginning of a sample event is greater than or equal to a predetermined validation time, ฯ adapt is updated according to
ฯ adapt ( v d )=ฯ adapt ( v d )+ k adapt [ฯ d โฯ adapt ( v d )]ฮ t update
where k adapt and ฮt update are factory-set parameters that together represent the speed at which the adaptive algorithms โlearnโ or develop a correlated data set. The last block on the FIG. 2 flowchart represents a correction to speed control algorithm 14 . The correction may be used to smooth iterations that may be present if algorithm 14 uses integrator action.
When engine speed error ฮต c , and the time rate of change of actual engine speed ฯ a decrease to predetermined tolerance values, and the time elapsed since the beginning of a sample event is greater than or equal to a predetermined validation time, ฯ adapt is updated according to
ฯ adapt (ฯ d )=ฯ adapt (ฯ d )+ k adapt [ฯ d โฯ adapt (ฯ d )]ฮ t update .
This is the same updating equation that is used in algorithm 18 , and it is derived in the same manner as is illustrated in FIG. 2 . The smoothing technique described above may be used to counter the effects of integrator action in algorithm 26 .
The substantially instantaneous estimates of engine speed and torque derived from algorithms 18 and 22 require interpolation among the discrete values programmed during watercraft calibration operation. For practice of the present invention there are many acceptable interpolation schemes, including high-order and Lagrangian polynomials, but the present embodiment utilizes a linear interpolation scheme. For example, algorithm 18 employs linear interpolation to calculate a value of ฯ adapt for any predetermined velocity v d . From a programmed table of v d values from v 0 to v n , inclusive of v m , and ฯ adapt values from ฯ 0 to ฯ n , inclusive of ฯ m , a value of m is chosen so that v d โงv m and v d <v m+1 . Algorithm 18 calculates intermediate values of engine speed according to the equation
ฯ adapt =ฯ m +[( v d โv m )/( v m+1 โv m )](ฯ m+1 โฯ m ).
Although algorithm 22 could also utilize any of several interpolation schemes, and is not constrained to duplication of algorithm 18 , in the present embodiment of the present invention, algorithm 22 calculates ฯ adapt using the same linear interpolation that algorithm 18 uses to calculate ฯ adapt . In order to implement adaptive update algorithm 18 when using a linearly interpolated table of values as the interpolation embodiment, the following procedure can be followed:
Compute a weighting factor x using the following equation:
x =[( v d โv m )/( v m+1 โv m )]
Note that x is always a value between 0 and 1.
Similar to algorithm 18 , update the two bracketing values ฯ m , ฯ m+1 in the linear table using the following equations:
ฯ m =ฯ m +(1 โx ) k adapt [ฯ d โฯ adapt ]ฮt update
ฯ m+1 =ฯ m+1 +( x ) k adapt [ฯ d โฯ adapt ]ฮt update
The other values in the linear table remain unchanged for this particular update, and are only updated when they bracket the operating condition of the engine at some other time. This same procedure can be used on the engine speed vs. torque adaptive table. It should be noted that if algorithm 18 is not present, then ฯ c will equal ฯ adapt . Likewise if algorithm 22 is not present then ฯ c will equal ฯ adapt .
Although the embodiment shown in FIG. 1 does not utilize extrapolation in its adaptive algorithms, the scope of the present invention could easily accommodate commonly understood extrapolation routines for extension of the algorithm 18 and algorithm 22 data sets.
Adaptive algorithms 18 and 22 are not required for operation of the present invention, but they are incorporated into the embodiment. Aided by commonly understood integrators, algorithms 14 and 26 are capable of ultimate control of a watercraft's velocity. However, the additional adaptive control provided by algorithms 18 and 22 enhances the overall transient response of system 100 .
The following table is an example of the velocity vs. engine speed adaptive table as it might be initialized from the factory. This table is a simple linear table which starts at zero velocity and extends to the maximum velocity of the boat (60 kph) at which the maximum engine speed rating (6000 rpm) is also reached:
v d (kph) ฯ adapt (rpm) 0 0 10 1000 20 2000 30 3000 40 4000 50 5000 60 6000
The following is an example of the velocity vs. engine speed adaptive after the boat has been driven for a period of time:
v d (kph) ฯ adapt (rpm) 0 0 10 1080 20 1810 30 2752 40 3810 50 5000 60 6000
Note that the engine speed values correlating to boat speeds of 50 and 60 kph have not been modified from the original initial values. This is because the boat was never operated at these desired speeds during the period of operation between the present table and the initial installation of the controller. FIG. 4 is a graphical representation of the data in the preceding tables.
Controller 30 (see FIG. 1 ) is the interface between calculated desired engine torque ฯ d and the throttle control that causes the ultimate changes in engine speed. Controller 30 may interpose any number of relationships between calculated desired engine torque ฯ d and engine speed, but the embodiment of the present invention utilizes a direct proportionality. Other embodiments of the present invention could use controller 30 to adjust engine parameters other than throttle setting. Such parameters could include spark timing, fuel flow rate, or airflow rate. The embodiment of the present invention contemplates a boat with a single speed transmission and a fixed pitch propeller. An alternate embodiment of the present invention could be used with boats having variable transmissions and/or variable pitch propellers. In these alternate embodiments, the controller 30 could adjust the transmission, pitch of the propeller, throttle setting, or a combination thereof.
FIG. 3 illustrates how an operator of watercraft 50 controls the speed of engine 53 and propeller 51 . The operator supplies predetermined and desired velocity v d through a control input device such as control keypad and display unit 59 to control module 65 that houses the algorithms and comparators of system 100 . GPS measurements from device 10 and predetermined velocity v d values are sent to control module 65 via communications link 55 . Communication link 57 feeds engine speed measurements from a tachometer to control module 65 . System 100 may be overridden at any time through operator control of manual throttle control 61 that controls engine throttle 63 .
Diagrammed in FIG. 5 is feedback system 101 which is an alternate embodiment of the present invention. In this embodiment, the comparator 12 is removed from system 101 . The velocity measurement determined by the GPS device 10 is fed directly to algorithm 14 . Algorithm 14 is modified to incorporate predetermined velocity v d and GPS output v GPS in the calculation to determine engine speed correction ฯ c .
Diagrammed in FIG. 6 is feedback system 102 which is another embodiment of the present invention. In this embodiment, system 102 incorporates an inertia measuring device 11 , an algorithm 15 , an algorithm 17 , and a velocity measuring device 31 . The inertia measuring device 11 measures the actual acceleration a Acc of a watercraft 50 and the velocity measuring device 31 measures the actual velocity v VMD of the same watercraft 50 . The output of the inertia measuring device 11 is input into algorithm 15 that converts actual acceleration a Acc to velocity v Acc according to the formula
v Acc =โซa ACC dt
The output from algorithm 15 velocity v Acc and velocity v VMD are input into algorithm 17 which calculates observed velocity v OBS according to the formula
v OBS =K P ( v VMD โv Acc )+ K D ( d/dt )( v VMD โv Acc )=โซ K i ( v VMD โv Acc )
In this embodiment algorithm 14 is modified to incorporate predetermined velocity v d , observed velocity v OBS , actual acceleration a Acc , and predetermined acceleration a d in the calculation to determine engine speed correction ฯ c .
As shown in FIG. 7 , for feedback system 102 it is also possible to incorporate a comparator to determine the velocity magnitude difference between the desired velocity v d and the observed velocity v OBS . Likewise, it is possible to incorporate another comparator to determine the acceleration magnitude difference between the desired acceleration a d and actual acceleration a Acc . The algorithm 14 would be modified to incorporate the velocity magnitude difference and the acceleration magnitude difference in the calculation to determine engine speed correction ฯ c .
For system 102 and other systems which incorporates the use of a inertia measuring device, the algorithms 14 and 26 , respectively, could include any common or advanced control loop transfer function including, but not limited to, series, parallel, ideal, interacting, noninteracting, analog, classical, and Laplace types. For both the algorithms 14 and 26 the embodiment utilizes a simple proportional-integral-derivative (PID) algorithm of the following type (exemplified by the algorithm 14 transfer function):
ฯ c =K p ฮต v +K d ฮต a +โซK i ฮต v dt.
Where K p , K d , and K i are, respectively, the appropriate proportional, derivative, and integral gains.
Diagrammed in FIG. 8 is feedback system 103 which is an alternate embodiment of the present invention. In this embodiment, system 103 incorporates an inertia measuring device 11 , and a velocity measuring device 31 . The inertia measuring device 11 measures the actual acceleration a Acc of a watercraft 50 and the velocity measuring device 31 measures the actual velocity v VMD of the same watercraft 50 . The algorithm 14 is modified to incorporate desired velocity v d , desired acceleration a d , actual acceleration a Acc , and actual velocity v VMD in the calculation to determine engine speed correction ฯ c .
As shown in FIG. 9 , for feedback system 103 it is also possible to incorporate a comparator to determine the velocity magnitude difference between the desired velocity v d and the actual velocity v VMD . Likewise, it is possible to incorporate another comparator to determine the acceleration magnitude difference between the desired acceleration a d and actual acceleration a Acc . The algorithm 14 would be modified to incorporate the velocity magnitude difference and the acceleration magnitude difference in the calculation to determine engine speed correction ฯ c .
Diagrammed in FIG. 10 is feedback system 106 which is another embodiment of the present invention. In this embodiment, system 106 incorporates an inertia measuring device 11 without a velocity measuring device. The inertia measuring device 11 measures the actual acceleration a Acc of a watercraft 50 . The algorithm 14 is modified to incorporate desired velocity v d , desired acceleration a d , and actual acceleration a Acc in the calculation to determine engine speed correction ฯ c .
As shown in FIG. 11 , for feedback system 106 it is also possible to incorporate a comparator to determine the acceleration magnitude difference between the desired acceleration a d and actual acceleration a Acc . The algorithm 14 would be modified to incorporate the acceleration magnitude difference in the calculation to determine engine speed correction ฯ c .
Diagrammed in FIG. 12 is feedback system 108 which is another embodiment of the present invention. In this embodiment, system 108 incorporates a velocity measuring device 31 and a GPS device 10 both of which capable of measuring the velocity of watercraft 50 . The velocity measuring device measures velocity v VMD and the GPS device measures velocity v GPS of the same watercraft 50 . In this embodiment, algorithm 14 is modified to incorporate desired velocity v d , velocity v VMD , and velocity v GPS in the calculation to determine engine speed correction ฯ c .
Diagrammed in FIG. 13 is feedback system 109 which incorporates an algorithm 17 and comparator 12 . The output of the velocity measuring device 31 v VMD and the output of the GPS device measures velocity v GPS are input into algorithm 17 which calculates observed velocity v OBS according to the formula
v OBS =K P ( v VMD โv GPS )+ K D ( d/dt )( v VMD โv GPS )=โซ K i ( v VMD โv GPS )
Observed velocity v OBS may be sent to either comparator 12 or algorithm 14 . If observed velocity v OBS is sent to comparator 12 , then comparator 12 determines the velocity magnitude difference between the desired velocity v d and the observed velocity v OBS . Comparator 12 output velocity error ฮต v is input to an algorithm 14 that converts ฮต v to engine speed correction ฯ c that is input to a second comparator 16 . If observed velocity v OBS is sent to algorithm 14 , in this embodiment algorithm 14 is modified to incorporate predetermined velocity v d and observed velocity v OBS in the calculation to determine engine speed correction ฯ c .
It will be apparent to those with ordinary skill in the relevant art having the benefit of this disclosure that the present invention provides an apparatus for controlling the velocity of a watercraft. It is understood that the forms of the invention shown and described in the detailed description and the drawings are to be taken merely as examples and that the invention is limited only by the language of the claims. The drawings and detailed description presented herein are not intended to limit the invention to the particular embodiments disclosed. While the present invention has been described in terms of alternate embodiments and a few variations thereof, it will be apparent to those skilled in the art that form and detail modifications can be made to that embodiment without departing from the spirit or scope of the invention.
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An automatic speed control system that provides desired watercraft velocity over land. The coupled algorithms correct engine speed and torque using inertia based measurements, GPS, and tachometer measurements, and the corrections are augmented and enhanced by velocity/speed and torque/speed relationships that are dynamically and adaptively programmed with real-time data collected during replicated operations of the watercraft in specified conditions.
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This is a continuation-in-part of my co-pending application Ser. No. 838,524 filed Mar. 11, 1986, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates generally to abrasion-resistant polymer and coating compositions and, in particular, to polymers and coatings that resist abrasion caused by entrained solids in a fluid flow environment.
The need to move fluids containing entrained solids through conduits such as pipes or tubes is common in many industries. The interior of such conduits is often abraded as the fluid/solid combination moves through it. This is a particular problem in hydropower plants where water containing entrained solids is moved through draft tubes to rotate impeller blades and produce electricity. Over a period of time the abrasion from entrained solids can destroy an uncoated surface, or remove protective coatings. In the latter case, the conduit draft tubes must be shut down and recoated.
Need exists for a polymer and/or coating thereof that resists abrasion on the inner walls of conduits in a fluid flow environment, particularly when the fluid contains entrained solids.
SUMMARY OF THE INVENTION
This invention provides an abrasion resistant polymer composition and coating wherein the polymer and coating composition contains from about 24 to 48 wt. % of a liquid epoxy resin, from about 24 to 48 wt. % of a blocked isocyanate prepolymer, from about 4.2 to 12 wt. % of a rheological additive, from about 10 to 14 wt. % of a curing agent for the epoxide and the isocyanate, from about 1 to 4 wt. % of a plasticizer, and from about 0.1 to 0.6 wt. % of a surface modifying agent containing silane groups. Optionally the polymer composition and coating can contain up to about 2 wt. % of pigments to provide visual aid to confirm thorough mixing and up to about 2 wt. % of fillers or auxilliary agents to aid in handling. Preferably, from about 0.4 to 2 wt. % of fillers is used.
The polymer or coating is produced by blending a first and second component of the polymer composition and curing the blend. The first component is a mixture of from about 30 to 60 wt. % of a liquid epoxy resin, from about 30 to 60 wt. % of a blocked isocyanate prepolymer, and from about 4 to 10 wt. % of a rheological additive. The second component is a mixture of from about 50 to 70 wt. % of the curing agent, from about 5 to 20 wt. % of a plasticizer, from about 0.5 to 3 wt. % of a surface modifying agent, and from about 5 to 20 wt. % of a rheologicl additive. Four parts by weight of the first component are blended with one part by weight of the second component and the resulting blend is cured to produce the polymer. When the blend is applied to a surface or substrate and cured, a coating is produced.
In a preferred embodiment, the blended composition comprises about 36.4 wt. % of an epoxy resin; about 36.4 wt. % of a blocked isocyanate prepolymer; about 9.98 wt. % of a rheological additive; about 12.84 wt. % of the curing agent, preferably polyglycol diamine; about 2.88 wt. % of a plasticizer, preferably dibutyl phthalate; and about 0.36 wt. % of a surface modifying agent containing silane groups.
DETAILED DESCRIPTION OF THE INVENTION
It is to be understood that the following elements of the composition include all equivalents thereto as would be recognized in the art.
Any suitable liquid epoxy resin can be used provided that at least 50 wt. %, preferably 80 wt. %, most preferably 100% of the lquid epoxy resins used is a bisphenol A-epichlorohydrin epoxy resin. The preferred such resin has an epoxide equivalent weight of 182-190, a viscosity (cps at 25ยฐ C.) of 11,000 to 14,000 and a specific gravity (25/25ยฐ C.) of 1.16. The most preferred bisphenol A-epichlorohydrin resin is a diglycidyl ether of bisphenol A having the theoretical structure: ##STR1## where n is 0.15. "D.E.R. 331," produced by Dow Chemical Corporation, Midland, Mich., is particularly preferred.
Examples of some liquid epoxy resins which can be used in quantities of up to about 50 wt. % of the liquid epoxy resin, preferably up to about 20 wt. % of the bisphenol A-epichlorohydrin resins of this invention, include low viscosity epoxy phenol novolac resins. The preferred such resin has an epoxy value (eq./100 g) of 0.54-0.58, a viscosity (cP at 25ยฐ C.) of 30,000 to 50,000 and the theoretical structure: ##STR2## "Epoxy Resin XB 3337" having an epoxy functionality of 2.4 produced by Ciba-Geigy Corporation is particularly preferred.
Any suitable blocked isocyanate prepolymer can be used, particularly alkyl phenol blocked disocyanates and blocked isocyanate-terminated polyether prepolymers. A preferred alkyl phenol blocked prepolymer is an alkyl phenol blocked toluene diisocyanate having ether and blocked urethane groups. This prepolymer has an empirically determined equivalent weight of 860-1000, a specific gravity at 20ยฐ C. of 1.05 and a viscosity at 25ยฐ C. of 900ยฑ300 PaยทS. "Desmocap 11A," produced by Mobay Chemical Corporation, Pittsburgh, Penn. is particularly preferred. Another preferred blocked isocyanate is an alkyl phenol blocked toluene diisocyanate polyether prepolymer having a specific gravity at 20ยฐ C. of 1.04, an equivalent weight of 2470, a viscosity at 25ยฐ C. of 23,000-43,000 cps, and an available isocyanate content of 1.7%. "Desmocap 12" produced by Mobay Chemical Corporation, is particularly preferred.
For best results, at least about 80 wt. %, preferably 90 wt. % and most preferably 100% of the blocked isocyanate prepolymer should be comprised of the alkyl phenol blocked toluene diisocyanate prepolymer described above. The remainder of the blocked isocyanate prepolymer can be any blocked isocyanate prepolymer that is compatible with the alkyl phenol blocked toluene diisocyanate and that unblocks under curing conditions.
Any suitable curing agent for the epoxide and the isocyanate that reacts to cure those components at about the same rate under the curing conditions described herein can be employed. Generally aliphatic and cycloaliphatic amines such as alkyleneamines are used including diamino-ethers having terminal primary amino groups. Isophorone diamine, 3-aminomethyl-3, 5, 5-trimethylcyclohexylamine, 3, 3' dimethyl-4, 4'-diaminodicyclohexyl methane, polyglycol diamines, and the like can be used either alone or in combination. The most preferred alkyleneamine, referred to herein as polyglycol diamine, has a molecular weight of about 220 and the formula NH 2 CH 2 CH 2 CH 2 O(CH 2 CH 2 O) 2 CH 2 CH 2 CH 2 NH 2 . "Polyglycoldiamine H-221," prouced by Union Carbide Corporation, New York, N.Y. is particularly preferred.
Any additive that will improve the flow and/or provide anti-sag properties to the paste or putty-like compositions of the invention may be used as the rheological additive of the invention. Preferably, a colloidal silica or hydrophobic fumed silica particularly surface modified with polymethyl silyl groups is employed. Surface modification is acheived by treating silica with an organosilicon to provide surface methyl groups in addition to surface hydroxyl groups. The rheological additive is important to maintain the shelf life and the physical properties or character of the paste or putty-like composition of the invention. "Cab-O-Sil N70TS," produced by Cabot Corporation, Tuscola, Ill. is a particularly preferred rheological additive. An organic derivative of a montmorillonite clay, treated with a quaternary ammonium chloride, for example, is also preferred. Most preferred is Bentone SD-2 rheological additive, a product of NL Industries, Inc.
Any suitable plasticizer may be employed in the composition and coating of this invention. While plasticizers are often thought of as imparting slip to a composition, they in fact promote the adhesion of the compositions and coatings of this invention. Some suitable plasticizers include phthalates such as alkyl benzyl phthalates, benzyl phthalates and dialkyl phthalates. Dibutyl phthalate is preferred.
Any suitable surface modifying agent that contains silane groups and can react with mineral fillers and the reactive materials of the coating to link the filler to the polymer backbone, particularly to the epoxy binder, and to the metal oxide of the substrate being coated, is preferred. Reactive silanes produce stronger compositions and promote adhesion to substrates, particularly metals such as aluminum and steel. Some suitable surface modifying agents that can be used include silanes, particularly organosilane esters known as gamma-aminoalkyltrialkoxysilanes. A preferred silane is gamma-aminopropyl triethoxysilane (NH 2 (CH 2 ) 3 Si (OC 2 H 5 ) 3 ) commercially available as "Silane A-1100" from Union Carbide Corporation, New York, N.Y.
Epoxy silanes, amino silanes, or both can be used in conjunction with the liquid epoxy resins, the curing agents, or both to provide the silane function making it unnecessary to employ a separate surface modifying agent reactant. The organo group (epoxy, amino) will react with the organic matrix and the silanol will react with the filler and/or the metal oxide surface of the substrate being coated. Some epoxy and amino silanes which can be used include gamma-glycidoxypropyltrimethoxysilane, beta-(3, 4 epoxycyclohexyl)-ethyltrimethoxy silane N-(beta-aminoethyl)gamma-aminopropyltrimethoxysilane, gamma-aminopropyltriethoxysilane, N'-beta-(aminoethyl)-N-(beta-aminoethyl)-gamma-aminopropyltrimethoxysilane, N-beta (aminoethyl)-gamma-aminopropyltrimethoxysilane, and the like and mixtures theroef. When an epoxy silane and/or amino silane is used, only that quantity is employed which will provide the polymer of the invention with 0.1 to 0.6% silane groups as described herein.
Any suitable auxiliary material, such as fillers, that will aid in the handling of the components or compositions of this invention may be employed but are not necessary for composition utility. Some such materials include talcs, clays, silicas, micas, and the like. A preferred filler is magnesium silicate, particularly that known as "Nytal 440," produced by R. T. Vanderbilt Company, Inc., Norwalk, Conn.
Pigments can be used to provide easy visual confirmation of thorough mixing but are not necessary for composition utility. Any first color pigment can be used in the first component, and any second color pigment can be used in the second component to be blended to produce the polymer composition and coating of the invention. Some suitable pigments include titanium dioxide, especially that commercially available as "R-902 Titanium Dioxide" from The Dupont Company, Wilmington, Del.; "Sunfast Blue" produced by Sun Chemical Corporation, Cincinnati, Ohio; tetrachloroisoindolinone or Pigment Yellow 109 produced as Irgazin Yellow 2GLTE by Ciba-Geigy Corporation. Yellow pigment in one component and blue in the other will yield a uniform green to indicate thorough mixing.
Although the coating composition of the invention can be applied to any surface that requires protection against abrasion as is, it is preferred that such surfaces are cleaned and surface contaminants such as scale, dirt, dust, grease, oil, water, or other foreign matter adverse to adhesion and cohesion are removed. The surface should then be roughened using any suitable means such as a grit blast, abrasion wheel, file, sanding paper or the like. Generally, the surface is then washed or wiped, preferably with a solvent that leaves no residue, and preferably at least twice, then dried completely. The surface is then coated with any suitable primer such as those well known for priming surfaces such as aluminum, steel, concrete, wood, plastics and the like. A preferred composition contains an epoxy polyamide as the primer compound wherein the epoxy is suitably any of those disclosed herein, particularly the diglycidyl ether of bisphenol A, and the polyamide is the reaction product of dimerized linoleic acid and diethylene triamine having an amine value of 230-246 and a viscosity of 20-42 poise at 75ยฐ C. A particularly preferred epoxy primer, is "PM-Epoxit Primer" , a product of Palmer International Corporation.
The polymer composition of this invention can be applied at thicknesses of up to about 2 inches on vertical surfaces without slumping, and cured in place. Generally, curing is carried out at ambient temperature and pressure, usually from 15ยฐ C. to 60ยฐ C., preferably 20ยฐ C. to 60ยฐ C., most preferably 40ยฐ C. Typically, pressure is not a consideration and no external pressure is applied. Superior strength, durability and adhesion provides high abrasion resistance, flexibility and elongation so that the coatings of the invention can be power-sanded, ground, or machined forty-eight hours after application. The coatings exhibit virtually no shrinkage during or after cure, repel moisture, and have a tensile adhesion of not less than 1600 psi. The composition offers superior resistance to abrasion when coated on the inner walls of conduits through which liquids containing entrained solids must pass and, by virtue of its paste-like consistency, is particularly useful for patching and filling holes and pits in a substrate such as the inner walls of a conduit.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
In the following description all parts and percentages are by weight unless otherwise specified and eqivalents can be substituted for the elements employed.
To produce a preferred polymer composition and coating of this invention, two separate components are first prepared. The first component contains 45.5 parts of a bisphenol A-epichlorohydrin liquid epoxy resin having an epoxide equivalent of 182-190 and a viscosity of 11,000 to 14,100, 45.5 parts of an alkyl phenol blocked toluene diisocyanate having an equivalent weight of 860-1000, 0.4 parts of titanium dioxide pigment, and 8.6 parts of colloidal silica as a rheological additive. These materials can be mixed using any automatic mixing and dispensing equipment currently available as well as, standard paste mixing equipment such as a double arm mixer, planatary mixer, or dough mixer, until thoroughly blended. Mixing time may be varied as desired but from about 30 to 45 minutes is usually adequate.
The second component contains 64.2 parts of NH 2 CH 2 CH 2 CH 2 O(CH 2 CH 2 O) 2 CH 2 CH 2 CH 2 NH 2 , 14 parts of dibutyl phthalate, 1.8 parts of gamma-aminopropyl triethoxysilane, 3.6 parts of magnesium silicate, 15.5 parts of colloidal silica as a rheological additive, and 0.9 parts of Sunfast Blue pigment. These materials can be mixed together in any standard mixing equipment as described above until thoroughly blended; about 30 to about 45 minutes is usually adequate.
The two components are combined immediately before the novel polymer composition of this invention is to be applied. At such time, four parts by weight of the first component are mixed with one part by weight of the second component until thoroughly blended as indicated by a uniform light blue color. Any standard mixing equipment as described above can be used.
The composition is a thixotropic paste having a pot life of about 40 minutes during which time it can be applied by any suitable means such as a trowel or spatula to the surface to be coated. A thickness of from about 1/16 inch to about 2 inches is generally adequate. The applied composition cures at ambient temperature in approximately 40 minutes.
The effectiveness of the coating compositions of this invention in protecting surfaces from abrasion due to entrained solids in fluid flow environments, such as in interiors of draft tubes employed in hydropower plants, can be demonstrated by the results of Taber abrasion tests. Specifically, using CS-17 wheels with a 1,000 gram load, an average wear loss of only 0.02 grams per 1,000 cycles, is observed while typical epoxy coating lose as much as much as ten times that weight.
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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An abrasion resistant polymer and coating composition comprising from about 24 to 48 wt. % of a liquid epoxy resin, from about 24 to 48 wt. % of a blocked isocyanate prepolymer, from about 4.2 to 12 wt. % of a rheological additive, from about 10 to 14 wt. % of a curing agent, from about 1 to 4 wt. % of a plasticizer, and from about 0.1 to 0.6 wt. % of a silane. The coating composition is especially effective in resisting abrasion from solids entrained in fluids in fluid flow environments.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] NOT APPLICABLE
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE TO A โSEQUENCE LISTING,โ A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK
[0003] NOT APPLICABLE
BACKGROUND OF THE INVENTION
[0004] This invention relates to a radio frequency or optical communication system in which a relay station is used to aid communication between a device and one or more other devices, and more particularly to an improvement allowing more efficient use of the available channel resource.
[0005] Self-interference cancellation is a theoretically efficient technique for removing interference on a channel containing a remote signal and a near signal in relayed communication between two or more devices involving the transmission of different signals within the same frequency band at the same time. In the example of communication between two devices, such transmission results in a composite signal that includes two signals, one originating from each device. As each device attempts to receive the signal originating from the other device (remote signal), it is hindered by interference caused by the signal originating from itself (near signal). Thus, self-interference cancellation works by generating a cancellation signal resembling the device's own near signal and using the cancellation signal to remove at least a portion of the near signal from the composite signal to obtain a signal closer to the desired remote signal. A number of self-interference cancellation and related techniques have been disclosed in U.S. Pat. Nos. 5,596,439 and 6,011,952, both issued to Dankberg et al., U.S. Pat. No. 5,280,537 issued to Sugiyama et al., U.S. Pat. No. 5,625,640 issued to Palmer et al., U.S. Pat. No. 5,860,057 issued to Ishida et al., and U.S. patent application Ser. No. 09/925,410 entitled METHOD AND APPARATUS FOR RELAYED COMMUNICATION USING BAND-PASS SIGNALS FOR SELF-INTERFERENCE CANCELLATION (Attorney Docket No. 017018-005000US).
[0006] However, special problems exist when a composite signal containing multiple channels requires self-interference cancellation. Self-interference may exist on fewer than all the channels. If the number of channels containing self-interference is less than the total number of channels, unnecessary resources and equipment may be committed, and there may be avoidable signal degradation.
[0007] A typical multi-channel satellite communication facility is shown in FIG. 1. Typically, an RF transmitter 102 , a transmit antenna 104 , an RF receiver 106 , and a receive antenna 108 are located outdoors, while IF and baseband equipment are located indoors. The indoor and outdoor systems are connected via cables that carry multi-channel IF signals, comprising a transmit IF path 107 and a receive IF path 109 . Individual IF transmit signals 111 from a number, M, of IF modulators 110 are combined in a multi-port signal combiner 112 to produce a multi-channel IF transmit signal on the transmit IF path 107 . The multi-channel IF transmit signal is translated to the RF transmission frequency by the RF transmitter 102 which then amplifies the signal and broadcasts it via the transmit antenna 104 .
[0008] The RF receiver 106 may share the transmit antenna 104 , or it may have a receive antenna 108 of its own. The RF receiver 106 performs the complementary function to the RF transmitter 102 , outputting a multi-channel IF received signal via the receive IF path 109 to a multi-port signal splitter 114 that distributes individual IF receive signals 115 to a number, D, of IF demodulators 116 . Digital baseband data from the facility's users comes into the IF modulators 110 for transmission and is output to the facility's users from the IF demodulators 116 . Note that a signal splitter or a signal combiner as discussed in the present invention may be implemented using the same device (signal splitter/combiner) which performs either function. Also, multi-port splitter/combiners as discussed in the present invention may be implemented as either a single device or as a number of devices in serial and/or parallel configurations.
[0009] In many practical systems, the above mentioned communication facility will broadcast to an intermediate site (such as a satellite transponder) which will rebroadcast the signal such that the originating facility will also receive its own signal. In such systems, the multi-channel IF received signal becomes a composite signal (multi-channel composite IF received signal).
[0010] [0010]FIG. 2 is an example frequency plot which shows the separate components of a multi-channel composite IF received signal. For clarity, only a few selected channels are shown. Note that although no absolute frequency is indicated in this plot, all of the signals shown are contained within the IF band that is used by the facility 100 . Note also that โchannelโ refers generally to a particular frequency band occupied by one or more signal. However, a signal said to occupy a particular channel may not be perfectly contained within the associated frequency band. Often such a signal has some portions extending into neighboring channels. Such interference between channels occurs in many communication systems and is not discussed further in the present application.
[0011] The Relayed Remote (RR) signal is composed of the D signals (RR 1 to RR D ) originating from remote terminals and destined for the local demodulators. The Relayed Near (RN) signal is composed of the M signals (RN 1 to RN M ) that are due to the facility's own transmissions. That is, the RN signal has been transmitted and then relayed back to the facility. Thus, the multi-channel composite IF received signal (the โcomposite received signalโ) is the sum of the RR and the RN signals, as shown in FIG. 2.
[0012] Since the M signals corresponding to VR and the D signals corresponding to RN can overlap in frequency, the total number of channels in the composite received signal can vary. If no overlap exists, the total number of channels is simply M+D. However, if there is overlap such that S channels are shared, the total number of channels is M+DโS. In more general terms, the composite received signal has a total number of M+DโS channels (where S=0 indicates the condition that no overlap exists).
[0013] In this example, the first channel (CH 1 ) and the last channel (CH M+DโS ) of the composite received signal are shared (bi-directional), and the second channel (CH 2 ) and the third channel (CH 3 ) are not shared. In order to properly demodulate the RR signal contained in the shared channels, the composite received signal must be processed to remove the interfering RN signal. To simplify this self-interference removal, it may be helpful to take advantage of the Local Near (LN) signal, which is the IF signal that is output from the combination of the IF modulators and input to the RF transmitter. The desired output signal, shown in the bottom of the figure, contains all of the RR channels and any RN channel that did not overlap in frequency with any RR channel.
[0014] As can be seen from FIG. 2, the number of shared frequency channels may indeed be less than the total number of channels that exist in the multi-channel composite IF received signal. A technique is needed for performing efficient self-interference cancellation only on those channels where self-interference is present. Is also desirable to dynamically select channels for self-interference cancellation without the need to physically reconfigure the relevant subsystems.
SUMMARY OF THE INVENTION
[0015] Multi-channel self-interference cancellation is provided in relayed electromagnetic communication between a first device and one or more other devices on one or more shared frequency channels. Specifically, near signals are generated at the first device and transmitted to a relay station. A composite signal is received at the first device from the relay station containing relayed versions of the near signals and relayed versions of remote signals transmitted from the one or more other devices, the composite signal having frequency channels including the one or more shared frequency channels, each shared frequency channel occupied by at least one of the relayed near signals and one of the relayed remote signals. One or more cancellation signals are selectively generated, each having a frequency band corresponding to one of the shared frequency channels. The cancellation signals are combined with the composite signal to produce a desired signal representing the relayed remote signals.
[0016] In one embodiment, the cancellation signals are generated along one or more parallel paths and combined with the composite signal to produce the desired signal.
[0017] In another embodiment, the composite signal is processed by one or more cascaded stages to produce the desired signal , wherein at each cascaded stage, one of the cancellation signals is generated and combined with the composite signal.
[0018] The invention will be better understood by reference to the following description in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] [0019]FIG. 1 depicts a typical multi-channel satellite communication facility.
[0020] [0020]FIG. 2 is a frequency plot showing separate components of a multi-channel composite IF received signal.
[0021] [0021]FIG. 3 depicts the desired configuration for integrating a multi-channel self-interference cancellation structure into an existing satellite communication facility.
[0022] [0022]FIG. 4 illustrates one embodiment of the multi-channel self-interference cancellation structure, in a parallel configuration.
[0023] [0023]FIG. 5 shows one implementation of the single channel self-interference cancellation signal estimator.
[0024] [0024]FIG. 6 illustrates another embodiment of the multi-channel self-interference cancellation structure, in a cascaded configuration.
DETAILED DESCRIPTION OF THE INVENTION
[0025] [0025]FIG. 3 shows the desired configuration for integrating a multi-channel self-interference cancellation structure 302 into an existing satellite communication facility 100 . The structure 302 receives the transmit IF path 107 from the multi-port signal combiner 112 . The transmit IF path 107 contains the multi-channel IF transmit signal, which represents the Local Near (LN) signal. The structure 302 also receives the receive IF path 109 from the RF receiver 106 . The receive IF path 109 contains the multi-channel composite IF received signal, which represents the sum of the Relayed Remote (RR) signal and the Relayed Near (RN) signal. The structure 302 outputs a continued transmit IF path 108 to the RF transmitter 102 . The structure 302 also outputs a continued receive IF path 110 to the multi-port signal splitter 114 .
[0026] As discussed above, existing self-interference cancellation techniques have been employed on individual channels. Certainly, each channel of a multi-channel system could be handled separately. That is, the received IF signal 109 can be split into D channels and each channel can be independently processed according to one of the existing self-interference cancellation techniques. To create a multi-channel output signal, all the channels would be combined back together. However, such a method requires equipment to process each of the D channels, even if some of the channels are not shared (such as the second channel in FIG. 2). For example, such equipment may include filters, upconverters, and/or downconverters to isolate and pass through the unshared frequency channels. As a result, performance of the unshared frequency channel will be degraded, since signals on the unshared frequency channels will receive additional processing.
[0027] [0027]FIG. 4 illustrates one embodiment of the multi-channel self-interference cancellation structure 302 , in a parallel configuration. The multi-channel composite IF received signal from the receive IF path 109 is split at a signal splitter 402 into a plurality of signals 404 and a direct path signal 406 . Each of the plurality of signals 404 is to be associated with a shared frequency channel. The direct path signal 406 is an extra copy of the multi-channel composite IF received signal. Thus, the number of signals outputted by the signal splitter 402 is the number of shared frequency channels plus one.
[0028] For each shared frequency channel, one of the signals 404 is downconverted by a certain frequency shift using a downconverter 410 such that the shared frequency channel, which occupies a particular frequency band of the signal 404 , is frequency-shifted to baseband. Each downconverter 410 thus generates a single channel baseband composite received signal 412 .
[0029] The multi-channel IF transmit signal from the transmit IF path 107 is split at a signal splitter 413 into an extra copy of the multi-channel IF transmit signal and a plurality of signals 414 . The extra copy of the multi-channel IF transmit signal is output from the multi-channel self-interference cancellation structure 302 on the continued transmit IF path 108 . For each shared frequency channel, one of the signals 414 is downconverted by a certain frequency shift using a downconverter 416 such that the shared frequency channel, which occupies a particular frequency band of the signal 414 , is frequency-shifted to baseband. Each downconverter 416 thus generates a single channel baseband Local Near (LN) signal 418 .
[0030] A plurality of feedback signals 424 are used in the cancellation process. For each shared frequency channel, one of the feedback signals 424 is downconverted by a certain frequency shift using a downconverter 426 such that the shared frequency channel, which occupies a particular frequency band of the signal 424 , is frequency-shifted to baseband. Each downconverter 426 thus generates a single channel baseband feedback signal 428 .
[0031] For each shared frequency channel, a single channel self-interference cancellation signal estimator 430 receives a single channel baseband composite received signal 412 , a single channel baseband LN signal 418 , and a single channel baseband feedback signal 428 , all of which correspond to the shared frequency channel. The estimator 430 uses these signals to generate and output a baseband estimate 432 of the Relayed Near (RN) signal, in phase-inverted form, associated with the shared frequency channel. The baseband estimate 432 is upconverted at an upconverter 434 to produce a single channel IF cancellation signal 436 occupying the shared frequency channel.
[0032] Each single channel self-interference cancellation signal estimator 430 receives a single channel baseband feedback signal 428 that is split at the signal splitter 422 and downconverted at the downconverter 426 . There is a delay due to these two steps which can be incorporated into the adaptive filter of the estimator 430 (if an adaptive filter exists).
[0033] The single channel IF cancellation signals 436 , each corresponding to a shared frequency channel, along with the direct path signal 406 , which corresponds to the multi-channel composite received signal, are combined at a signal combiner 440 to produce the multi-channel IF output signal 420 . In this manner, the Relayed Near (RN) signal is substantially removed from all shared frequency channels of the multi-channel IF output signal. The signal 420 is input to a signal splitter 422 , which outputs the continued receive IF path 110 and the feedback signals 424 .
[0034] [0034]FIG. 5 illustrates one implementation of the single channel self-interference cancellation signal estimator 430 derived from U.S. patent application Ser. No. 09/925,410 entitled METHOD AND APPARATUS FOR RELAYED COMMUNICATION USING BAND-PASS SIGNALS FOR SELF-INTERFERENCE CANCELLATION (Attorney Docket No. 017018-005000US), discussed above. Note that the single channel self-interference cancellation signal estimator 430 can be implemented in many different ways. It can certainly be derived from other self-interference cancellation techniques disclosed in the prior art, such as those previously discussed.
[0035] In FIG. 5, the estimator 430 receives a composite received signal 502 , a Local Near (LN) signal 504 , and a feedback signal 506 and produces an estimate cancellation signal 508 . As described below, the estimator 430 frequency-, phase-, and time-correlates the LN signal 504 with the composite received signal 502 . The composite received signal 502 is input to a time and phase detectors block 510 . A time-delayed and phase-rotated local near signal 512 is also input to the block 510 . The time and phase detectors block 510 performs frequency, phase, and time correlation function(s) on its inputs and produces outputs that drive a time tracking loop block 514 and a phase tracking loop block 516 .
[0036] The time-delayed and phase-rotated local near signal 512 is generated from the local near signal as herein explained. The local near signal is time-delayed by a time delay block 518 , which is under the control of the time tracking loop block 514 . The time-delayed signal is then phase-rotated by the phase rotation block 520 , which is under the control of the phase tracking loop block 516 . The phase rotation is capable of removing frequency differences between the local near signal and the received near (RN) component of the composite received signal. The resulting signal is the time-delayed and phase-rotated local near signal 512 .
[0037] The time-delayed and phase-rotated local near signal 512 is input to an adaptive filter 522 to compensate for channel and relay effects. The adaptive filter 522 also receives the feedback signal 506 . The adaptive filter 522 outputs the estimate cancellation signal 508 , which for this implementation is an out of phase estimate of the RN signal.
[0038] An alternative implementation (not shown) of the single channel self-interference cancellation signal estimator 430 involves demodulating an appropriate Local Near (LN) signal corresponding to the shared frequency channel of interest from the composite received signal 502 . The demodulated signal can be remodulated and the remodulated signal is produced as the output of this implementation of the single channel self-interference cancellation signal estimator 430 .
[0039] Yet another implementation (not shown) of the single channel self-interference cancellation signal estimator 430 involves extracting from the composite received signal 502 a carrier signal corresponding to the shared frequency channel of interest. The carrier signal is then used to modulate an appropriate information sequence taken from the transmit path. The resultant signal is the output of this alternative implementation of the single channel self-interference cancellation signal estimator 430 .
[0040] Referring back to FIG. 4, note that depending on the particular implementation, the single channel self-interference cancellation signal estimator 430 may not require as input the single channel baseband Local Near (LN) signal 418 and/or the single channel baseband feedback signal 428 . If such is the case, the associated structures shown in FIG. 4 for generating the single channel baseband Local Near (LN) signal 418 and/or the single channel baseband feedback signal 428 may be eliminated.
[0041] As an illustrative example, consider the implementation discussed above that demodulates the RN signal from the composite signal and remodulates the RN signal. This particular implementation operates on the composite signal alone, without utilizing either the LN signal or the feedback signal. A multi-channel self-interference cancellation structure 302 having such an implementation of the single channel self-interference cancellation signal estimator 430 will not need to generate either the single channel baseband Local Near (LN) signals 418 or the single channel baseband feedback signals 428 .
[0042] Yet another implementation (not shown) of the present invention on the transmit side would be possible if the individual IF transmit signals 111 from FIG. 1 were easily accessible as separate signals. In this case, each of the signals 111 is split into two output signals. Splitting all of the signals 111 in this manner produces two sets of the signals 111 . The first set of signals 111 continue on the IF transmit path to a multi-port signal combiner, where they are combined to produce the multi-channel composite IF transmit signal 108 shown in FIG. 3. The second set of the signals 111 are input to the multi-channel self-interference cancellation structure 302 . In FIG. 4, the second set of signals 111 are provided as the signals 414 , which are inputs to the downconverters 416 .
[0043] Likewise, another implementation (not shown) of the present invention on the receive side would be possible if the individual IF receive signals 115 of FIG. 1 were easily accessible as separate signals. In this case, each of the signals 115 is split into two output signals. Splitting all of the signals 115 in this manner produces two sets of the signals 115 . The first set of signals 115 would continue on the IF receive path to the demodulators 116 . The second set of signals 115 are input to the multi-channel self-interference cancellation structure 302 . In FIG. 4, the second set of signals 116 are provided as the signals 404 , which are inputs to the downconverters 410 .
[0044] The multi-channel self-interference cancellation structure 302 may incorporate dynamic re-assignment of shared frequency channels. By using a controller unit (not shown) connected to the downconverters 410 , downconverters 416 , downconverters 426 , and upconverters 434 , the frequency spectrum location of each shared frequency channel can be changed by simply controlling these downconverters/upconverters to perform downconverting/upconverting according to newly defined frequency shifts. Accordingly, shared frequency channels can be redefined without requiring any physical modification of equipment by a technician. The flexibility of the multi-channel self-interference cancellation process is thus dramatically improved.
[0045] It is important to also note that the multi-channel self-interference cancellation structure 302 , as embodied in FIG. 4, does not commit excessive equipment to unshared frequency channels. This is clearly illustrated by the fact that the number of signals produced from the signal splitter 402 only needs to be the number of shared frequency channels, S, plus one, not the total number of channels M+DโS (in the multi-channel composite received IF signal) plus one. For example, if channel 2 is an unshared frequency channel, then the signal splitter 402 needs not have an output 454 associated with channel 2 .
[0046] Also, other equipment associated with channel 2 , such as a downconverter 460 , downconverter output 462 , signal splitter output 464 , downconverter 466 , downconverter output 468 , signal splitter output 474 , downconverter 476 , downconverter output 478 , single channel self-interference cancellation signal estimator 480 , estimator output 482 , upconverter 484 , and signal splitter input 486 need not be included in the multi-channel self-interference cancellation structure 302 . According to the invention, such extra equipment corresponding to unshared frequency channels can be eliminated, as shown by dashed lines in FIG. 4. There will be little, if any, degradation on unshared channels, since the only processing that occurs to the original multi-channel signal is the subtraction of the LN signals from the shared channels.
[0047] [0047]FIG. 6 illustrates another embodiment of the multi-channel self-interference cancellation structure 302 , in a cascaded configuration. Only one stage 600 (the ith stage) of the cascade is shown in FIG. 6. The number of stages corresponds to the number of shared frequency channels present, and the stages are placed one after another in a cascaded fashion. The ith stage 600 shown in FIG. 6 corresponds to a particular shared frequency channel.
[0048] A first input path 602 provides the multi-channel composite IF received signal from the stage previous to the ith stage 600 . This signal is split at a signal splitter 604 into signals 606 and 608 . The signal 608 is the direct path of the multi-channel composite IF received signal. The signal 606 is downconverted by a certain frequency shift using a downconverter 610 such that the shared frequency channel, which occupies a particular frequency band of the signal 606 , is frequency-shifted to baseband, producing a single channel baseband composite received signal 612 .
[0049] A second input path 620 provides the multi-channel IF transmit signal from the stage following the ith stage 600 . This signal is split at a signal splitter 622 into a signal provided on a first output path 624 and a signal 626 . The first output path 624 is connected to the stage previous to the ith stage 600 . The signal 626 is downconverted by a certain frequency shift using a downconverter 630 such that the shared frequency channel, which occupies a particular frequency band of the signal 626 , is frequency-shifted to baseband, producing a single channel baseband Relayed Near (RN) signal 632 .
[0050] A feedback signal provided on a feedback path 634 is downconverted by a certain frequency shift using a downconverter 636 such that the shared frequency channel, which occupies a particular frequency band of the feedback signal, is frequency-shifted to baseband. This produces a single channel baseband feedback signal 638 .
[0051] A single channel self-interference cancellation signal estimator 640 receives the single channel baseband composite received signal 612 , the single channel baseband LN signal 632 , and the single channel baseband feedback signal 638 . The estimator 640 uses these signals to generate and output a baseband estimate 642 of the Relayed Near (RN) signal, in phase-inverted form, associated with the shared frequency channel to which the ith stage 600 corresponds. The baseband estimate 642 is upconverted at an upconverter 644 to produce a single channel IF cancellation signal 646 occupying the particular shared frequency channel.
[0052] The single channel IF cancellation signal 646 and the signal 608 that is the extra copy of the multi-channel composite IF received signal, are combined at a signal combiner 648 to produce a stage-processed multi-channel IF output signal 650 . The stage-processed multi-channel IF output signal 650 is split at a signal splitter 652 into two paths, a second output path 654 and the feedback path 634 . The second output path 654 is connected to the stage following the ith stage 600 . The feedback path 634 provides the stage-processed multi-channel IF output signal 650 as the feedback signal.
[0053] The stage-processed multi-channel IF output signal 650 , provided to the stage following the ith stage 600 via the second output path 654 , has the ith Local Near (LN) signal substantially removed. That is, the ith stage 600 substantially removes the LN signal from the shared frequency channel corresponding to the ith stage 600 .
[0054] Note that the single channel self-interference cancellation signal estimator 640 receives the single channel baseband feedback signal 638 , which is split at the signal splitter 653 and downconverted at the downconverter 636 . The delay of these two steps can be incorporated into the adaptive filter of the estimator 640 (if an adaptive filter exists).
[0055] The ith stage 600 connects with a previous stage via the first input path 602 and the first output path 628 and connects with a following stage via the second input path 620 and the second output path 654 . In this manner, a number of cascading stages can be constructed, each performing substantial removal of the RN signal associated with a particular shared frequency channel. One particular advantage of this cascade approach is that it readily scales. Each additional stage is placed in-line with the others, using two-port signal splitters/combiners. There is no need for differently sized signal splitters/combiners. Another advantage of the cascade approach is that each stage can be made โfail-safe.โ If there is a failure in one stage, that stage can easily be skipped through the use of bypass switches.
[0056] Note that the single channel self-interference cancellation signal estimator 640 can be implemented in many different ways, as discussed for the single channel self-interference cancellation signal estimator 430 of FIG. 4. Similarly, estimator 640 can be derived from any one of a number of self-interference cancellation techniques existing in the prior art.
[0057] Also, depending on the particular implementation, the single channel self-interference cancellation signal estimator 640 may not require as input the single channel baseband Local Near (LN) signal 632 and/or the single channel baseband feedback signal 638 . If such is the case, the associated structures shown in FIG. 6 for generating the single channel baseband Local Near (LN) signal 632 and/or the single channel baseband feedback signal 638 may be eliminated.
[0058] The multi-channel self-interference cancellation structure 302 , as embodied in the cascaded configuration illustrated in FIG. 6, may incorporate dynamic re-assignment of shared frequency channels. By using a controller unit (not shown) connected to the appropriate downconverters and upconverters of each stage, the frequency spectrum location of each shared frequency channel can be changed by simply controlling these downconverters/upconverters to perform downconverting/upconverting according to newly defined frequency shifts. For example, in the ith stage 600 , such a control unit may control downconverter 610 , 630 , and 636 and upconvert 644 . Accordingly, shared frequency channels can be re-defined without requiring any physical modification of equipment by a technician. The flexibility of the multi-channel self-interference cancellation process is thus dramatically improved.
[0059] It is important to also note that the multi-channel self-interference cancellation structure 302 , as embodied in the cascaded configuration illustrated in FIG. 6, does not commit excessive equipment to unshared frequency channels. This is clearly illustrated by the fact that the number of cascaded stages correspond to the number of shared frequency channels, not the total number of channels M+DโS of the multi-channel signal. Extra stages corresponding to unshared frequency channels need not exist. According to the invention, such extra equipment can be eliminated. A distinct advantage of the invention is the low level of signal degradation that is achieved for both the shared and un-shared channels.
[0060] Although the present invention has been described in terms of specific embodiments, it should be apparent to those skilled in the art that the scope of the present invention is not limited to the described specific embodiments.
[0061] The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. It will, however, be evident that additions, subtractions, substitutions, and other modifications may be made without departing from the broader spirit and scope of the invention as set forth in the claims.
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Multi-channel self-interference cancellation is provided in relayed electromagnetic communication between a first device and one or more other devices on one or more shared frequency channels. Specifically, near signals are generated at the first device and transmitted to a relay station. A composite signal is received at the first device from the relay station containing relayed versions of the near signals and relayed versions of remote signals transmitted from the one or more other devices, the composite signal having frequency channels including the one or more shared frequency channels, each shared frequency channel occupied by at least one of the relayed near signals and one of the relayed remote signals. One or more cancellation signals are selectively generated, each having a frequency band corresponding to one of the shared frequency channels. The cancellation signals are combined with the composite signal to produce a desired signal representing the relayed remote signals.
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This application is the U.S. national phase of International Application No. PCT/EP2010/056147, filed 6 May 2010, which designated the U.S. and claims priority to EP Application No. 09159630.4, filed 7 May 2009, the entire contents of each of which are hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to novel cyclopeptides and to a method for preparing cyclopeptides using substituted boronic acids.
BACKGROUND OF THE INVENTION
Cyclopeptides are polypeptides in which the terminal amine and carboxyl groups form an internal peptide bond. Several cyclopeptides are known for their advantageous medicinal properties. An excellent example of this is the class of echinocandins which are potent antifungals. Cyclopeptides can be naturally occurring compounds but may also be obtained by total synthesis or by synthetic or genetic modification of naturally occurring or produced precursors; the latter class is referred to as semi synthetic cyclopeptides. Examples of medicinally useful echinocandins are the cyclic hexapeptides anidulafungin, caspofungin, cilofungin and micafungin which are useful in treating fungal infections especially those caused by Aspergillus, Blastomyces, Candida, Coccidioides and Histoplasma. Anidulafungin, caspofungin and micafungin are all semi synthetic cyclopeptides derivable from naturally occurring echinocandins such as for instance echinocandin B, pneumocandin A 0 or pneumocandin B 0 .
Although nature can provide a substantive part of the complex chemical structure of semi synthetic cyclopeptides, and in many cases having all chiral centers in the required configuration, the subsequent chemical conversions into the therapeutically active derivatives nevertheless often require unprecedented approaches. Usually the structures in question are chemically unstable and/or prone to racemization and simply do not allow for otherwise obvious synthetic manipulation taught in synthetic organic chemical textbooks. This chemical instability is even more pronounced in anidulafungin, caspofungin and micafungin due to the presence of the notoriously fragile hemiaminal moiety.
The preparation of caspofungin (1) from fermentatively obtained pneumocandin B 0 (2), with R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ) in both compounds, may serve as an example of the complexity in cyclopeptide chemistry described above.
Initially, in U.S. Pat. No. 5,378,804 a process was disclosed requiring five steps and having major drawbacks in lack of stereo selectivity and an overall yield of less than 10%. The conversion of the amide functionality in (2) into the amine as present in (1) required two steps, namely dehydration of the primary amide to the nitrile followed by reduction to the amine. Introduction of the ethylenediamine moiety at the hemiaminal position required three steps. An improved procedure was disclosed in U.S. Pat. No. 5,552,521 requiring three steps in total, namely reduction of the amide followed by activation with thiophenol and stereoselective displacement of the thiophenol function to introduce the ethylenediamine moiety. Still this process suffers from a low overall yield of no more than 25%. A further improvement in yield was realized in U.S. Pat. No. 5,936,062 describing intermediate protection of, amongst others, the vicinal hydroxyl groups of the homotyrosine moiety using phenylboronic acid. Two synthetic approaches were suggested, the first one starting with phenylboronic acid protection followed by reduction with borane and activation with thiophenol and the second one starting with thiophenol activation followed by phenylboronic acid protection and reduction with borane. Both approaches were completed by introduction of the ethylenediamine moiety and overall yields ranging from 25-36% were reported. In the first approach the claimed sequence of steps involved the presence of a diboronate ester intermediate. An alternative approach to this was described by W. R. Leonard et al. (J. Org. Chem. 2007, 72, 2335-2343) involving the initial formation of a mono-phenylboronate ester protection of the vicinal hydroxyl groups allowing for immediate introduction of the thiophenol activating group. This latter approach resulted in a 45% overall yield.
Today there are no convenient alternatives to the above approaches so there remains a challenge for finding alternative chemical approaches that allow for conversion of naturally occurring cyclopeptides into semi synthetic cyclopeptides. These approaches can be used as alternative to prior art methods, or preferably to achieve a higher yield, higher chemical purity, higher optical purity, less waste streams or any or all of the above.
DETAILED DESCRIPTION OF THE INVENTION
In a first aspect of the present invention there is provided a method for the preparation of a first cyclopeptide comprising a vicinal diol from a second cyclopeptide comprising a vicinal diol wherein the vicinal diol is protected with a boronic acid derivative. In the context of the present invention, a vicinal diol is a compound bearing at least two hydroxyl functional groups that are attached to adjacent carbon atoms. The use of ethyl- and phenylboronic acid as a protecting group for 1,2-diols is well known, for instance from Greene, T. W. and Wuts, P. G. M., Protective Groups in Organic Synthesis (John Wiley & Sons, Inc., New York/Chichester/Brisbane/Toronto/Singapore, 2 nd Ed., 1991, ISBN 0-471-62301-6). In addition, the use of phenylboronic acid in cyclopeptide chemistry has been described in U.S. Pat. No. 5,936,062. In the present invention, approaches alternative to the use of phenylboronic acid were investigated in order to solve several problems associated with phenylboronic acid such as sub-optimal yields and toxicity of the phenylboronic acid which is eventually released in the waste stream. It was found that substituted boronic acids other than phenylboronic acid or naphthylboronic acid are suitable protecting groups for vicinal diols in cyclopeptides. Notably cyclohexylboronic acid and 4-tert-butylphenylboronic acid, both unmentioned in the major textbook in the art by Greene and Wuts, described above.
The suitability of cyclohexylboronic acid is particularly surprising as the skilled person would preferably look for alternate compounds bearing a chromophore (such as tolyl, naphthyl or phenyl) as chromophoric compounds greatly facilitate analysis during research and production activities. Cyclohexyl boronic acid does not have such a chromophore thereby making it a non-obvious choice. Moreover, to the best of our knowledge cyclohexylboronic acid is not suggested in any means in the art in question.
In a first embodiment there is disclosed a method for the preparation of a compound of general formula (1) or a salt thereof comprising the steps of treating a compound of general formula (2) wherein R 1 in compounds (1) and (2) is C(O)R 2 wherein R 2 is C 9 -C 21 alkyl, C 9 -C 21 alkenyl, C 1 -C 10 alkoxyphenyl, alkoxynaphthyl or C 1 -C 10 alkoxyterphenyl, with a substituted boronic acid, an activating agent and a reducing agent. Preferably R 1 is C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 . The steps mentioned above may be carried out in various sequences using various activating agents and reducing agents as known to the skilled person. Preferred activating agents are thiols with general formula R 3 โSH. More preferably said activating agents are 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercapto-1-methylimidazole, 2-mercapto-4-methoxyphenol or thiophenol. The various preferred sequence of steps are outlined in the following embodiments.
In a second embodiment said compound of general formula (2) is first reacted with a substituted boronic acid R 5 โB(OH) 2 to afford a compound of general formula (3) wherein R 5 is cyclohexyl, substituted cyclohexyl or substituted phenyl. In a next step, compound (3) is reacted with a compound of general formula R 3 โSH to afford a compound of general formula (4) with R 5 as mentioned above.
The above conversion may be carried out in a variety of solvents that are inert to the reaction conditions such as (substituted) alkanes, ethers and substituted benzenes, for instance acetonitrile, dichloromethane, diethyl ether, tetrahydrofuran, toluene and the like. Preferably the substituted boronic acid R 5 โB(OH) 2 is cyclohexylboronic acid or 4-tert-butylphenylboronic acid. Preferred temperatures are from โ100ยฐ C. to 30ยฐ C., more preferably from โ50ยฐ C. to 0ยฐ C., most preferably from โ20ยฐ C. to โ5ยฐ C. Subsequently, compound (4) is hydrolyzed to afford a compound of general formula (5) which is then reduced to afford a compound of general formula (6);
Finally, compound (6) is converted to said compound of general formula (1) by reaction with ethylenediamine. In W. R. Leonard et al. (J. Org. Chem. 2007, 72, 2335-2343) the formation of the mono-phenylboronate ester of the vicinal hydroxyl groups required, as evidenced from the experimental details, two equivalents of phenylboronic acid. Although it was established that this excess could also be applied in the present invention with a substituted boronic acid, it was surprisingly established that lower amounts of substituted boronic acid were equally or even better suitable thereby reducing the amount of waste. Thus, the preferred ratio, on a molecular basis, of substituted boronic acid to the compound of general formula (1) is from 1.01 to 3, more preferably from 1.05 to 2 and most preferably from 1.1 to 1.5.
In a third embodiment a compound of general formula (2) is first reacted with a substituted boronic acid to afford a compound of general formula (3), which is subsequently reacted with a compound of general formula R 3 โSH to afford a compound of general formula (4) with R 5 as mentioned above. Compound (4) is then reduced and hydrolyzed to afford a compound of general formula (6) which is converted to said compound of general formula (1) by reaction with ethylenediamine.
In a fourth embodiment a compound of general formula (2) is first reacted with a substituted boronic acid to afford a compound of general formula (3) which is subsequently reduced to afford a compound of general formula (7) with R 5 as mentioned above. Compound (7) is then reacted with a compound of general formula R 3 โSH and hydrolyzed to afford a compound of general formula (6) which is converted to said compound of general formula (1) by reaction with ethylenediamine.
In a fifth embodiment, the compound of general formula (4) described above is first reacted with a silylating agent prior to further conversions. Suitable silylating agents are bis(trimethylsilyl)trifluoroacetamide, tert-butyldimethylsilyl chloride, trimethylsilyl chloride and the like.
In a sixth embodiment said reaction with a substituted boronic acid R 5 โB(OH) 2 that is not phenylboronic acid or naphthylboronic acid is succeeded by and/or combined with reaction with phenylboronic acid. It was surprisingly found that such combination of protecting groups can lead to still more favourable results. Preferably said reaction with phenylboronic acid is carried out after reaction with from 0. to 1.2 equivalents of a substituted boronic acid R 5 โB(OH) 2 that is not phenylboronic acid or naphthylboronic acid
In a second aspect of the present invention there is provided a compound of general formula (8)
wherein R 1 is C(O)R 2 wherein R 2 is C 9 -C 21 alkyl, C 9 -C 21 alkenyl, C 1 -C 10 alkoxyphenyl, C 1 -C 10 alkoxynaphthyl or C 1 -C 10 alkoxyterphenyl, wherein R 4 is OH or โSR3 wherein R 3 is benzimidazol-2-yl, benzothiazol-2-yl, 1-methylimidazol-2-yl, 4-methoxyphenyl or phenyl, wherein R 5 is cyclohexyl, substituted cyclohexyl or substituted phenyl and wherein X is O or H,H.
In one embodiment the preferred substituent R 1 is C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 which is the substituent present in the antifungal agent caspofungin.
In another embodiment the preferred substituent R 4 is OH or โS-phenyl. In yet another embodiment the preferred substituent R 5 is cyclohexyl or 4-tert-butylphenyl.
In a third aspect of the invention there is provided the use of a substituted boronic acid in the preparation of a cyclopeptide bearing a vicinal diol. Protection of diols with substituted boronic acids is not limited to the compound of the first embodiment of the first aspect of the present invention but can also be applied to similar cyclopeptides containing a vicinal diol system. In a preferred embodiment the cyclopeptide is anidulafungin, caspofungin, cilofungin or micafungin.
EXAMPLES
General
Pneumocandin was obtained by fermentation of Glarea Lozoyensis ( Zalerion arboricola ) as described in WO 2000/008197. Commercially available reagents were used as received unless mentioned otherwise. Solvents were dried over 3 โซ molecular sieves. HPLC analysis was carried out using a Waters XBridge C18 column, 3.5 ฮผm, 150 mmร2.1 mm under the following conditions:
Injection volume: 5 ฮผL Detection: UV (210 and 270 nm) Flow: 0.40 ml/min Column temp: 25ยฐ C. Mobile phase A: 50 mM K 2 HPO 4 +acetonitrile (6:4); pH 6.0 Mobile phase B: 75% acetonitrile Gradient:
Time (min)
0
1.5
5.0
7.0
7.5
11
% A
100
100
0
0
100
100
% B
0
0
100
100
0
0
Retention times (all with R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ): 1: 2.5 min; 2: 5.8 min; 6 (R 3 =phenyl): 6.4 min; 5 (R 3 =phenyl): 7.3 min.
Example 1
Pneumocandin cyclohexylboronate ester using 2.0 equiv. cyclohexylboronic acid
(8; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 4 =OH; R 5 =cyclohexyl; X=O)
Under N 2 finely divided pneumocandin B 0 (0.68 g, assay total pneumocandins 95%, assay pneumocandin B 0 and C 0 81%; 0.61 mmol pneumocandins) and cyclohexylboronic acid (156 mg, 1.22 mmol) were added to acetonitrile (20 ml, pre-dried on molecular sieves of 3 โซ).
Example 2
Pneumocandin phenylthioaminal cyclohexylboronate ester
8; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 4 =S-phenyl; R 5 =cyclohexyl; X=O)
To the suspension obtained in Example 1 thiophenol (190 ฮผl, 1.86 mmol) was added. The suspension was cooled and maintained at โ15ยฐ C. and trifluoromethanesulfonic acid (163 ฮผL, 1.83 mmol) was added and the reaction mixture was maintained at โ15ยฐ C. for 20 h under nitrogen. The conversion was followed by HPLC: sample after 3 h (50 ฮผl reaction mixture+20 ฮผl 0.85 M sodium acetate+0.88 ml methanol): conversion was 79%; after 20 h the conversion was 97%.
Example 3
Pneumocandin phenylthioaminal
(5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl)
The reaction mixture obtained in Example 2 was quenched with 0.844 M sodium acetate trihydrate (2.2 ml; 1.86 mmol). The suspension was warmed to 17ยฐ C., maintained for 2 h, and cooled to 0ยฐ C. and stirred at 0ยฐ C. overnight, during which the concentration of the title compound in the mother-liquor decreased from 2.1 to 1.6 g/l. The precipitate was filtered off, washed with 90% acetonitrile (3ร10 ml), and dried under vacuum at 30ยฐ C., giving 0.53 g of the title compound as an off-white powder with an HPLC-assay of 87%. Isolated yield (over B 0 and C 0 ): 77%. Loss to mother liquor: 44 ml; 1.4 g/l; 10%.
Example 4
Pneumocandin cyclohexylboronate ester using 1.1 equiv. cyclohexylboronic acid
(8; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 4 =OH; R 5 =cyclohexyl; X=O)
Under nitrogen finely divided pneumocandin B 0 (0.68 g, assay total pneumocandins 95%, assay pneumocandin (B 0 and C 0 ) 81%; 0.61 mmol pneumocandins) and cyclohexylboronic acid (86 mg, 0.67 mmol) were added to acetonitrile (20 ml, pre-dried on molecular sieves of 3 โซ).
Example 5
Pneumocandin phenylthioaminal cyclohexylboronate ester
(8; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 4 =S-phenyl; R 5 =cyclohexyl; X=O)
To the suspension obtained in Example 4 thiophenol (190 ฮผl, 1.86 mmol) was added. The suspension was cooled and maintained at โ15ยฐ C. and trifluoromethanesulfonic acid (163 ฮผL, 1.83 mmol) was added and the reaction mixture was maintained at โ15ยฐ C. for 20 h under nitrogen after which the conversion was determined with HPLC (50 ฮผl reaction mixture+20 ฮผl 0.85 M sodium acetate+0.88 ml methanol) to be 99%.
Example 6
Pneumocandin phenylthioaminal
(5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl)
The reaction mixture obtained in Example 5 was quenched with 0.844 M sodium acetate trihydrate (2.2 ml; 1.86 mmol). The suspension was warmed to 17ยฐ C., maintained overnight, and cooled to 0ยฐ C. and stirred at 0ยฐ C. for 3 h. The precipitate was filtered off, washed with 90% acetonitrile of 0ยฐ C. (3ร8 ml), and dried under vacuum at 30ยฐ C., giving 0.51 g of the title compound as an off-white powder with an HPLC-assay of 90%. Isolated yield (over B 0 and C 0 ): 77%.
Example 7
Pneumocandin phenylthioaminal amine
(6; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl) using BSTFA (3 equiv.)
Under nitrogen phenylthioaminal (5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl; 0.56 g; 0.32 mmol; assay 67% by NMR) was suspended in dry THF (30 ml). At 20ยฐ C. bis(trimethylsilyl)trifluoroacetamide (BSTFA, 0.26 ml; 0.97 mmol) was added and the mixture was stirred for 2 h at 20ยฐ C. under nitrogen. The solution was cooled to โ2ยฐ C. and 1 M BH 3 .THF (2.25 ml; 2.25 mmol) was added. The solution was stirred at หโ2ยฐ C. overnight. A sample of 3 ml was taken which was quenched with 2 M HCl (200 ฮผl): conversion 24%. Another portion of 1 M BH 3 .THF (0.75 ml; 0.75 mmol) was added and stirring at โ2ยฐ C. was continued for 24 h. The reaction mixture was quenched with 2 M HCl (2 ml; 4 mmol). Hydrogen gas evolved from the mixture. This solution was stirred at 0ยฐ C. for 2 h and analyzed by HPLC: conversion 34%.
Example 8
Pneumocandin phenylthioaminal amine
(6; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl) using BSTFA (4 equiv.)
Under nitrogen phenylthioaminal (5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl; 0.56 g; 0.32 mmol; assay 67% by NMR) was suspended in dry THF (30 ml). At 20ยฐ C. BSTFA (0.34 ml; 1.27 mmol) was added and the mixture was stirred for 2 h at 20ยฐ C. under nitrogen. The solution was cooled to โ2ยฐ C. and 1 M BH 3 .THF (2.25 ml; 2.25 mmol) was added. The solution was stirred at หโ2ยฐ C. overnight. A sample of 3 ml was taken which was quenched with 2 M HCl (200 ฮผl): conversion 28%. Another portion of 1 M BH 3 .THF (0.75 ml; 0.75 mmol) was added and stirring at โ2ยฐ C. was continued for 24 h. The reaction mixture was quenched with 2 M HCl (2 ml; 4 mmol). Hydrogen gas evolved from the mixture. This solution was stirred at 0ยฐ C. for 2 h and analyzed by HPLC: conversion 41%.
Example 9
Pneumocandin phenylthioaminal amine (6; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl) using BSTFA (5 equiv.)
Under nitrogen phenylthioaminal (5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl; 0.56 g; 0.32 mmol; assay 67% by NMR) was suspended in dry THF (30 ml). At 20ยฐ C. BSTFA (0.43 ml; 1.60 mmol) was added and the mixture was stirred for 1 h at 20ยฐ C. under nitrogen. The solution was cooled to โ3.5ยฐ C. and 1 M BH 3 .THF (2.24 ml; 2.24 mmol) was added. The temperature rose to โ3ยฐ C. and the solution was stirred at หโ3ยฐ C. overnight. It was quenched with 2 M HCl (2 ml; 4 mmol). Hydrogen gas evolved from the mixture. This solution was stirred at 0ยฐ C. for 2.5 h and analyzed by HPLC: conversion 32%.
Example 10
Pneumocandin phenylthioaminal amine cyclohexylboronate ester
(8; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 4 =S-phenyl; R 5 =cyclohexyl; X=H, H) using cyclohexylboronic acid and BSTFA
Under nitrogen phenylthioaminal (5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl; 0.40 g; 0.23 mmol; assay 66% by NMR) was suspended in dry THF (25 ml). Cyclohexylboronic acid (33 mg; 0.26 mmol) was added. The mixture was heated to reflux. THF was distilled off and the volume was maintained by replenishment with dry THF. The temperature of the reaction mixture rose from 65.4 to 66.3ยฐ C. After 1.5 h the mixture (20 ml) was cooled to 20ยฐ C. in 1 h. BSTFA (183 ฮผl; 11; 0.68 mmol) was added and the mixture was stirred for 1 h at 20ยฐ C. under nitrogen. The solution was cooled to โ2ยฐ C. in 2 h and 1 M BH 3 .THF (1.6 ml; 1.6 mmol) was added. The solution was stirred at หโ2ยฐ C. overnight. A sample of 1 ml was taken which was quenched with 2 M HCl (67 ฮผl): conversion 83%. Another portion of 1 M BH 3 .THF (0.45 ml; 0.45 mmol) was added and stirring at โ2ยฐ C. was continued for 3 hours.
Example 11
Pneumocandin phenylthioaminal amine
(6; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl)
The reaction mixture obtained in Example 10 was quenched with 2 M HCl (1.4 ml; 2.8 mmol). Hydrogen gas evolved from the mixture. This solution was stirred at 0ยฐ C. for 2 h and analyzed by HPLC: conversion 83%.
Example 12
Comparison of cyclohexylboronic acid (CHBA), phenylboronic acid (PBA) and 4-tert-butylphenylboronic acid (TBPBA) in the synthesis of pneumocandin phenylthioaminal
(5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl)
Several combinations of cyclohexylboronic acid (CHBA), phenylboronic acid (PBA) and 4-tert-butylphenylboronic acid (TBPBA) were investigated in time on conversion, yield and formation of so-called bis-adducts (products having a second thiophenol moiety).
12.1: 2 equiv. PBA
Under nitrogen finely divided 2 (CAS0902/187; 1 g, assay total pneumocandins 100%, 0.94 mmol pneumocandins) and phenylboronic acid (PBA; 115 mg, 0.94 mmol), were added to 30 ml dry acetonitrile (<30 ppm water) and the mixture was stirred at RT for 60 min. PBA (115 mg; 0.94 mmol) was added, followed by thiophenol (290 ฮผl, 2.84 mmol) and the suspension was cooled to โ15ยฐ C. At โ15ยฐ C. triflic acid (250 ฮผl, 2.82 mmol) was added and the reaction mixture was stirred at โ15ยฐ C. for 26 h.
Time (h) Conversion (%) Bis-adducts/5 Yield (%) 0.5 50.4 0.99 50.2 1 62.2 0.96 61.8 1.5 71.1 0.97 70.6 2 76.5 1.05 75.9 3 83.4 1.20 82.5 4 88.3 1.25 87.3 6 95.3 1.44 94.0 9 98.6 1.72 96.9 19 99.9 2.58 97.3 26 100 3.38 96.6
12.2: 1 equiv. PBA and 1 equiv. CHBA
Under nitrogen finely divided 2 (1 g, 0.94 mmol pneumocandins) and CHBA (120 mg, 0.94 mmol), were added to 30 ml dry acetonitrile (<30 ppm water) and the mixture was stirred at RT for 60 min. PBA (115 mg; 0.94 mmol) was added, followed by thiophenol (290 ฮผl, 2.84 mmol) and the suspension was cooled to โ15ยฐ C. At โ15ยฐ C. triflic acid (250 ฮผl, 2.82 mmol) was added and the reaction mixture was stirred at โ15ยฐ C. for 26 h.
Time (h) Conversion (%) Bis-adducts/5 Yield (%) 0.5 44.5 1.71 44.2 1 52.7 1.71 52.2 1.5 59.4 1.63 58.8 2 63.5 1.63 62.8 3 69.8 1.58 69.0 4 75.0 1.60 74.1 6 81.8 1.66 80.7 9 87.1 1.79 85.7 19 93.4 2.31 91.4 26 95.5 2.57 93.2
12.3: 1 equiv. PBA and 1 equiv. TBPBA
Under nitrogen finely divided 2 (1 g, 0.94 mmol pneumocandins) and TBPBA (167 mg, 0.94 mmol), were added to 30 ml dry acetonitrile (<30 ppm water) and the mixture was stirred at RT for 60 min. PBA (115 mg; 0.94 mmol) was added, followed by thiophenol (290 ฮผl, 2.84 mmol) and the suspension was cooled to โ15ยฐ C. At โ15ยฐ C. triflic acid (250 ฮผl, 2.82 mmol) was added and the reaction mixture was stirred at โ15ยฐ C. for 26 h.
Time (h) Conversion (%) Bis-adducts/5 Yield (%) 0.5 48.8 1.38 48.5 1 59.1 1.25 58.7 1.5 66.5 1.26 65.9 2 71.4 1.28 70.7 3 76.4 1.45 75.6 4 80.8 1.45 79.8 6 87.3 1.57 86.1 9 91.2 1.82 89.7 19 97.2 2.59 94.8 26 98.3 2.80 95.6
12.4: 1.2 equiv. CHBA
Under nitrogen finely divided 2 (1 g, 0.94 mmol pneumocandins) and CHBA (144 mg, 1.13 mmol), were added to 30 ml dry acetonitrile (<30 ppm water) and the mixture was stirred at RT for 60 min. Thiophenol (290 ฮผl, 2.84 mmol) was added and the suspension was cooled to โ15ยฐ C. At โ15ยฐ C. triflic acid (250 ฮผl, 2.82 mmol) was added and the reaction mixture was stirred at โ15ยฐ C. for 26 h.
Time (h) Conversion (%) Bis-adducts/5 Yield (%) 0.5 62.4 1.67 61.7 1 68.0 1.85 67.1 1.5 74.7 1.91 73.6 2 78.3 1.95 77.1 3 83.5 2.10 82.0 4 87.7 2.37 85.8 6 92.9 2.57 90.6 9 95.9 2.99 93.2 19 97.9 4.70 93.4 26 98.0 5.70 92.6
12.5: 1.2 equiv. TBPBA
Under nitrogen finely divided 2 (1 g, 0.94 mmol pneumocandins) and TBPBA (200 mg, 1.13 mmol), were added to 30 ml dry acetonitrile (<30 ppm water) and the mixture was stirred at RT for 60 min. Thiophenol (290 ฮผl, 2.84 mmol) was added and the suspension was cooled to โ15ยฐ C. At โ15ยฐ C. triflic acid (250 ฮผl, 2.82 mmol) was added and the reaction mixture was stirred at โ15ยฐ C. for 26 h.
Time (h) Conversion (%) Bis-adducts/5 Yield (%) 0.5 70.6 1.92 69.6 1 76.2 2.11 75.0 1.5 78.1 2.34 76.6 2 79.4 2.51 77.8 3 80.4 2.77 78.6 4 81.9 2.98 79.9 6 85.2 3.40 82.7 9 91.3 3.86 88.1 19 96.9 5.11 92.1 26 98.1 5.82 92.5
12.6: 2 equiv. CHBA
Under nitrogen finely divided 2 (1 g, 0.94 mmol pneumocandins) and cyclohexylboronic acid (CHBA; 86 mg, 0.67 mmol), were added to 20 ml dry acetonitrile and the mixture was for 60 min. Next thiophenol (190 ฮผl, 1.86 mmol) was added and the suspension was cooled to โ15ยฐ C. At โ15ยฐ C. triflic acid (163 ฮผl, 1.84 mmol) was added and the reaction mixture was stirred at โ15ยฐ C. for 20 h.
Time (h) Conversion (%) Bis-adducts/5 Yield (%) โ3 54.2 0.24 54.1 20 86.2 2.27 84.5
12.7: 2 equiv. TBPBA
Under nitrogen finely divided 2 (1 g, 0.94 mmol pneumocandins) and cyclohexylboronic acid (CHBA; 120 mg, 0.67 mmol), were added to 20 ml dry acetonitrile and the mixture was for 60 min. Next thiophenol (190 ฮผl, 1.86 mmol) was added and the suspension was cooled to โ15 ยฐ C. At โ15ยฐ C. triflic acid (163 ฮผl, 1.84 mmol) was added and the reaction mixture was stirred at โ15ยฐ C. for 20 h.
Time (h)
Conversion (%)
Bis-adducts/5
Yield (%)
โ3
76.7
1.27
75.9
20
94.1
3.04
91.4
Example 13
Pneumocandin phenylthioaminal
(5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl) using a mixture of cyclohexylboronic acid and phenylboronic acid
Under nitrogen finely divided 2 (1.0 g, assay total pneumocandins 100%, 0.94 mmol pneumocandins) and cyclohexylboronic acid (120 mg, 0.94 mmol) were added to 30 ml dry acetonitrile. The mixture was stirred at 35-40ยฐ C. for 1 h. After cooling to 20ยฐ C. phenylboronic acid (115 mg; 0.94 mmol) and thiophenol (290 ฮผl, 2.84 mmol) were added and the suspension was cooled to โ15ยฐ C. and triflic acid (250 ฮผL, 2.82 mmol) was added and the reaction mixture was maintained at โ15ยฐ C. for 20 h. The reaction mixture was quenched with 0.85 M sodium acetate.trihydrate (3.32 ml; 2.8 mmol) and the suspension was maintained at 17ยฐ C. for 2 h, cooled to 0ยฐ C. and stirred overnight. The precipitate was filtered off, washed three times with 10 ml 90% acetonitrile, and dried under vacuum at 30ยฐ C., giving 0.87 g of the title product with a purity of 72.% (HPLC).
Example 14
Pneumocandin phenylthioaminal
(5; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl) using a mixture of 4-tert-butylphenylboronic acid and phenylboronic acid
Under nitrogen finely divided 2 (1.0 g, assay total pneumocandins 100%, 0.94 mmol pneumocandins) and 4-tert-butylphenylboronic acid (167 mg, 0.94 mmol) were added to 30 ml dry acetonitrile. The mixture was stirred at 35-40ยฐ C. for 1 h. After cooling to 20ยฐ C. phenylboronic acid (115 mg; 0.94 mmol) and thiophenol (290 ฮผl, 2.84 mmol) were added and the suspension was cooled to โ15ยฐ C. and triflic acid (250 ฮผL, 2.82 mmol) was added and the reaction mixture was maintained at โ15ยฐ C. for 20 h. The reaction mixture was quenched with 0.85 M sodium acetate.trihydrate (3.32 ml; 2.8 mmol) and the suspension was maintained at 17ยฐ C. for 2 h, cooled to 0ยฐ C. and stirred overnight. The precipitate was filtered off, washed three times with 10 ml 90% acetonitrile, and dried under vacuum at 30ยฐ C., giving 0.86 g of the title product with a purity of 74.7% (HPLC).
Example 15
Pneumocandin phenylthioaminal amine
(6; R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl) using 4-tert-butylphenylboronic acid and BSTFA (3 equiv.)
Under nitrogen 5 (R 1 =C(O)(CH 2 ) 8 CH(CH 3 )CH 2 CH(CH 3 )CH 2 CH 3 ; R 3 =phenyl; 3.0 g; 71.7%) was suspended in dry THF (120 ml). 4-tert-Butylphenylboronic acid (0.464 g; 2.6 mmol) was added and the mixture was heated to reflux and azeotropically dried by passing the refluxate through a bed of molecular sieves of 0.3 nm (400 g) until the reaction temperature remained constant (T increased from 67.2 to 67.5ยฐ C.). After 4 h the mixture was cooled to 21ยฐ C. and BSTFA (1.87 ml; 7.08 mmol) was added and the mixture was stirred for 1 h at 20ยฐ C. under nitrogen. The solution was cooled to โ10ยฐ C. and 1 M BH 3 .THF (10.65 ml; 10.65 mmol) was added between โ12 and โ10ยฐ C. The solution was stirred at หโ10ยฐ C. overnight. The reaction mixture was sampled (0.5 ml reaction mixture+50 ฮผl 2M HCl; diluted with 10 ml methanol) and the conversion was determined with HPLC to be 66%.
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The present invention relates to a method for preparing cyclopeptides by means of protection with a substituted boronic acid. The present invention also discloses novel boronate esters of cyclopeptides of general formula (8).
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This is a division of application Ser. No. 07/326,409 filed Mar. 20, 1989 now U.S. Pat. NO. 4,950,549 issued 8/21/90 which is a continuation of application Ser. No. 07/069,040 filed July 1, 1987, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to irradiated polypropylene articles, such as fibers, films, and nonwoven fabrics and to a method for preparing such articles.
2. Background Information
Polypropylene is often a material of choice for articles such as fiber, films and molded articles due to its various properties such as non-toxicity and inertness as well as its low cost and the ease with which it can be extruded, molded, and formed into articles. It is often desirable to graft-polymerize monomers onto polypropylene substrates using ionizing radiation, e.g., electron beam radiation, to provide such properties as hydrophilicity, hydrophobicity, increased adhesion to adhesives, surfaces on which secondary reactions can occur, and ion exchange capacity. However, polypropylene treated with ionizing radiation is subject to degradation, e.g., embrittlement, discoloration, and thermal sensitivity, during or subsequent to irradiation.
The addition of various stabilizers, e.g., antioxidants, to the polypropylene material has been suggested to prevent discoloration and degradation.
U.S. Pat. No. 4,110,185 (Williams et al.) discloses irradiation sterilized articles of polypropylene which have incorporated therein a mobilizer which increases the free volume of the polymer and, therefore, lowers the density of the polymer. Suitable mobilizers mentioned include hydrocarbon oils, halogenated hydrocarbon oils, phthalic ester oils, vegetable oils, silicone oils, and polymer greases.
U.S. Pat. No. 4,113,595 (Hagiwara et al.) discloses irradiated crosslinked polyolefin molded products of a blend of polyolefin, a compound having acetylenic linkage, and an aromatic hydrocarbon-substituted organic amine or an aromatic secondary amino compound.
U.S. Pat. Nos. 4,274,932 and 4,467,065 (Williams et al.) disclose polypropylene stabilized for irradiation sterilization. The polypropylene has a narrow molecular weight distribution and has incorporated therein a mobilizer, as used in U.S. Pat. No. 4,110,185, described hereinabove.
U.S. Pat. No. 4,432,497 (Rekers) discloses radiation-stable polyolefin compositions containing a benzhydrol or benzhydrol derivative stabilizer.
U.S. Pat. No. 4,460,445 (Rekers) discloses radiation-stable polyolefin compositions containing a hindered phenolic stabilizer and a benzaldehyde acetal stabilizer.
European Patent Application No. 0,068,555 (Lenzi) discloses irradiation-sterilizable polypropylene articles, the polypropylene having one to eight weight percent low density polyethylene added thereto.
U.S. Pat. No. 3,987,001 (Wedel et al.) discloses an ultraviolet protectorant composition for surface application by aerosol to polyolefins, which composition contains a 2-hydroxy benzophenone and benzoate ester ultraviolet protectorant, a polymethacrylate binder, a solvent, and propellant.
Although the addition of the various stabilizers to polypropylene serves to diminish degradation by radiation, the use of additives increases costs, some additives may pose toxicological problems when contacted with pharmaceuticals, and some additives may adversely affect the physical properties of the polypropylene. Also, when the polypropylene is subjected to high temperatures during processing, e.g., such as occurs during blown microfiber web extrusion, the additives, especially antioxidants, are often destroyed, i.e., decomposed. The present invention overcomes these problems without addition of radiation stabilizing additives as required in the afore-mentioned Williams et al. '185, '932, and '065, Hagiwara et al. '595, Rekers '497 and '445, Lenzi '555, and Wedel '001 patents, and provides low cost polypropylene articles having graft-polymerized monomers thereon and a method for preparing irradiated polypropylene articles, with the articles retaining useful tensile properties even after prolonged storage periods.
SUMMARY OF THE INVENTION
The present invention provides polypropylene articles of non-crystalline mesomorphous polypropylene, which polypropylene need not contain radiation stabilizing additives, and the polypropylene having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene. The irradiated articles such as films retain useful tensile properties after storage periods of as long as at least four months. For example, films of the invention generally retain an elongation at break of at least 200 percent, preferably at least 300 percent, after irradiation, and blown microfiber webs of the elongation at break that they exhibited prior to irradiation. Blown microfiber webs generally retain a modulus of resilience of at least about 20 N-m/cm 3 , preferably 30 N-m/cm 3 .
The invention further provides a method for preparing irradiated polypropylene articles, the steps of which include: extruding polypropylene, which polypropylene need not contain radiation stabilizing additives; quenching the extruded polypropylene immediately after extrusion to provide non-crystalline mesomorphous polypropylene; coating at least a portion of the surface of non-crystalline mesomorphous polypropylene with an ionizing radiation graft-polymerizable monomer; and irradiating the non-crystalline mesomorphous polypropylene with a dosage of ionizing radiation that would degrade crystalline polypropylene and is sufficient to effect graft-polymerization of the monomer. The irradiated articles, after six months storage, are substantially undegraded.
Although non-crystalline, mesomorphous polypropylene is known (Natta, G., et al. Structure and Properties of Isotactic Polypropylene, Del Nuovo Cimento, Supplemento Al, Volume XV, Serie X, N.1, 1960, pp. 40-51) the present invention for the first time, insofar as known, applies a dose of ionizing radiation to non-crystalline, mesomorphous polypropylene to achieve non-degraded polypropylene products having monomer graft-polymerized thereto or a coating cured in situ thereon. In fact, it has been thought that crystalline regions in polypropylene provide oxygen-impermeable regions which limit the extent of oxidation and reduce the maximum oxidation rate, and that readily-accessible amorphous regions were preferentially attacked (Pimer, S.H., ed., Weathering and Degradation of Plastics, Gordon and Breach, Science Publishers Inc., New York, 1966, pp. 104-107).
It is suspected that the radiation stability of the non-crystalline mesomorphous polypropylene is related to control of the morphology. The non-crystalline mesomorphous polypropylene has been described as a non-spherulitic structure by P. H. Geil (Polymer Single Crystals, Interscience, N.Y., 1963, p. 270). Crystalline polypropylene may have "chain-folds", i.e., crystalline/amorphous folds, in the structure which provide areas for radical attack because of their higher energy. In contrast, the non-crystalline mesomorphous structure is believed to have ordering as in a Fringed Micelle model with no chain-fold defects. It is suspected that this lack of chain fold defects minimizes the number of sites for radical attack and thereby provides the resistance to radiation degradation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the X-ray diffraction pattern of the non-crystalline mesomorphous polypropylene film of Example 1.
FIG. 2 is the X-ray diffraction pattern of the crystalline polypropylene film of Comparative Example 2.
FIG. 3 is a photograph of water soluble ink applied to the surface of the film of Example 1 prior to graft polymerization.
FIG. 4 is a photograph of water soluble ink applied to the surface of the film of Example 1 after graft polymerization.
FIG. 5 is the X-ray diffraction pattern of the non-crystalline mesomorphous polypropylene blown microfiber web of Example 7.
FIG. 6 is the X-ray diffraction pattern of the crystalline polypropylene blown microfiber web of Comparative Example C9.
DETAILED DESCRIPTION OF THE INVENTION
Polypropylene to be used in products of the invention can be extruded from polymer melt in any shape which can be rapidly cooled throughout after extrusion to obtain non-crystalline mesomorphous polypropylene. The shape and/or thickness of the extruded material will be dependent on the efficiency of the quenching systems utilized. Generally, films, fibers, and blown microfiber webs are the preferred extruded materials. The extruded polypropylene should not be subjected to any treatment at temperatures above about 140ยฐ F. (60ยฐ C.), such as annealing, orientation, or stretching, prior to irradiation as such treatment can change the non-crystalline mesomorphous polypropylene structure to a predominantely crystalline structure. After irradiation, the polypropylene can be annealed, stretched, or oriented, if properties provided by such treatments are desired.
The polypropylene may contain conventional additives such as antistatic materials, dyes, plasticizers, ultraviolet absorbers, nucleating agents, surfactants, and the like. The amount of additives is typically less than ten weight percent of the polymer component, preferably less than two percent by weight.
To obtain the non-crystalline mesomorphous phase polypropylene, the extruded material must be quenched immediately after extrusion before the material reaches the crystalline state. The presence of the non-crystalline mesomorphous phase polypropylene can be confirmed by X-ray diffraction. FIGS. 1 and 5 are X-ray diffraction patterns for mesomorphous polypropylene and FIGS. 2 and 6 are X-ray diffraction patterns for crystalline polypropylene. Although the term "non-crystalline mesomorphous" or "mesomorphous" is used to describe the polypropylene useful in the present invention, the material contains some crystalline phase polypropylene as determined by density measurements using a gradient column. Generally, the percent crystallinity of the non-crystalline mesomorphous polypropylene is below about 45 percent.
Various known methods of quenching can be used to obtain the non-crystalline mesomorphous structure including plunging the extruded material into a cold liquid, e.g., ice water bath, spraying the extruded material with a liquid such as water, and/or running the extruded material over a cooled roll or drum.
Extruded polypropylene film is preferably quenched by contact with a quench roll or by plunging the film into a quench bath, such as an ice-water bath as disclosed by R. L. Miller ("On the Existence of Near-range Order in Isotactic Polypropylenes", Polymer, 1, 135 (1960). Where a quench roll is used, the roll temperature is preferably maintained at a temperature below about 75ยฐ F. (24ยฐ C.) and the film is generally in contact with the roll until solidified. The quench roll should be positioned relatively close to the extruder die, the distance being dependent on the roll temperature, the extrusion rate, the film thickness, and the roll speed. Generally, the distance from the die to the roll is about 0.1 in (0.25 cm) to 2 in (5 cm). Where a quench bath is used, the bath temperature is preferably maintained at a temperature below about 40ยฐ F. (4ยฐ C.). The bath should be positioned relatively close to the die, generally about 0.1 in (0.25 cm) to 5 in (13 cm) from the die to the bath.
Polypropylene melt blown microfibers are produced by extruding molten polymer through a die into a high velocity hot air stream to produce fibers having an average fiber diameter of less than about 10 microns. The fibers are generally collected on a drum in the form of a web. The preparation of microfiber webs is described in Report No. 4364 of the Naval Research Laboratories, published May 25, 1954, entitled "Manufacture of Superfine Organic Fibers," by Wente, Van A. et al. and in Wente, Van A., "Superfine Thermoplastic Fibers" in Industrial Engineering Chemistry, Vol. 48, No. 8, August, 1956, pp. 1342-1346.
To achieve non-crystalline, mesomorphous polypropylene webs, the blown microfiber web is preferably quenched by spraying with a liquid such as water or by cooling the collector drum onto which the microfiber web is collected. Optimum quenching can be achieved by spraying the fiber web near the die, then collecting the web on a cooled drum. The water spray is preferably at a temperature of less than about 50ยฐ F. (10ยฐ C.) and less than about 1 inch (2.5 cm) from the die and the collector drum is preferably about 2 in (5 cm) to 4 in (10 cm) from the die, but can-be as much as 8 in (20 cm) to 10 in (25 cm) depending on extrusion rates.
The non-crystalline mesomorphous phase polypropylene can have graft-polymerized thereto monomers which are commonly used to modify surface characteristics of polyolefin substrates such as those described in Hsiue et al., Preirradiation Grafting of Acrylic and Methacrylic Acid onto Polyethylene Films:Preparation and Properties. J. of Applied Polymer Science, 30, 1023-33 (1985) and Shkolnik et al., Radiation-Induced Grafting of Sulfonates On Polyethylene. J. of Applied Polymer Science, 27, 2189-2196 (1982) and U.S. Pat. No. 3,634,218 (Gotohda) which are incorporated herein by reference for that purpose. For example, adhesion promoting primers such as N,N-dimethylacrylamide, glycidyl acrylate and diisopropylacrylamide for use with acrylate adhesives, glycidyl acrylate, trimethylolpropane triacrylate, and hydroxyethyl acrylate for use with epoxy adhesives, and N,N-dimethylaminoethylacrylate, N-vinyl-2-pyrrolidone and 2-vinyl pyridine for use with cyanoacrylate adhesives can be graft-polymerized onto the surface of the non-crystalline mesomorphous phase polypropylene. Monomers which provide hydrophilicity to the surface of the polypropylene substrate such as acrylic acid, N-vinyl-2-pyrrolidone and sulfoethyl methacrylate can be graft-polymerized onto the polypropylene substrate.
The following non-limiting examples are provided to further illustrate the invention. In these examples, the following tests were used to characterize the polypropylene films and microfiber webs:
Tensile properties (film): Samples of film 1/2 in (1.25 cm) wide were tested for yield stress and elongation at break using an Instronโข model no. 1122 at a gauge length of 2 in (5 cm) and a crosshead speed of 2 in/min (5 cm/min).
Tensile properties (microfiber web): One-inch wide samples were tested for energy required to stretch to yield point using an Instronโข model no. 1122 at a gauge length of 0.08 in (2 mm), a crosshead speed of 2 in/min (5 cm/min), chart speed of 50 in/min (125 cm/min), and full scale of 2 kg. The modulus of resilience is calculated as described in Higdon, A., Mechanics of Materials, John Wiley & Sons, Inc., N.Y., 1976, pgs 104-106.
180ยฐ Peel adhesion:
A 2.5 cm wide, 20.3 cm long strip of pressure-sensitive adhesive tape (Scotchโข brand tape no. is adhered to a 10.1 cm wide, 15.2 cm long sheet of test substrate with a free end of the tape extending beyond the end of the test substrate. The sample is rolled twice with a 1.35 kg hard rubber roller to ensure contact between the adhesive and the test substrate. The sample is aged at room temperature (22ยฐ C.) for 24 hours. The free end of the tape is removed from the test substrate at a rate of 6 inches/minute using a Slip/Peel Tester, available from Instrumentors, Inc.
EXAMPLE 1 AND COMPARATIVE EXAMPLE C1
Polypropylene films were prepared from Cosden 8670 polypropylene polymer (melt flow index 4; average molecular weight, by GPC-204,000) using a 11/4 in (3.2 cm) Brabenderโข extruder with a 12 in (30.5 cm) wide film die at a thickness of about 1.5 mil (0.04 mm) under the following conditions:
Melt temperature (ยฐC.): 206
Screw speed (rpm): 47
Polymer flow rate (kg/hr): 4.7
Die temperature (ยฐC.): 204
The films were extruded onto a chrome-plated 3 in (7.6 cm) diameter casting roll spaced one-inch (2.5 cm) from the die. The film was in contact with the roll for about 2.5 seconds. The roll was maintained at 44ยฐ F. (6.7ยฐ C.) and 150ยฐ F. (65.5ยฐ C.) to provide non-crystalline mesomorphous film (Example 1) and crystalline film (Comparative Example 1), respectively.
Each film was coated with a solution containing 99.9 weight percent acrylic acid and 0.1 weight percent wetting agent (FC-430, available from 3M Company). The films were irradiated using an electron beam at a dosage of 5 Mrad in an inert (nitrogen) atmosphere to effect graft polymerization of the acrylic acid onto the polypropylene films. Control films without the acrylic acid coating were also exposed to 5 Mrad electron beam irradiation. Non-irradiated, graft-polymerized, and control films were tested for yield stress and elongation at break after 4 months storage at 70ยฐ F. (21ยฐ C.). The results are shown in Table I.
TABLE I______________________________________ Comparative Example 1 Example 1 Yield Elongation Yield Elongation Stress at Stress at (kg/cm.sup.2) break (%) (kg/cm.sup.2) break (%)______________________________________Non-irradiated 160 730 229 880Irradiated/ 134 660 250 280acrylicacid graftIrradiated/ 151 640 223 520no graft______________________________________
The data in Table I shows that the non-crystalline mesomorphous film of Example 1 loses very little elongation at break (9.6%) after graft polymerization and storage, while the crystalline film of Comparative Example 1 exhibits a significant loss in elongation at break (68%) after graft polymerization and storage.
Samples of the film of Example 1 before and after graft polymerization of the acrylic acid on the surface of the film were tested for hydrophilicity by applying a water-based ink on the film. FIG. 3 shows the lack of hydrophilicity of the film prior to graft polymerization of the acrylic acid as evidenced by the beads of ink formed on the surface of the film. FIG. 4 shows the hydrophilicity of the film after graft polymerization of the acrylic acid as evidenced by the sharp lines of ink on the film surface.
EXAMPLES 2-4 AND COMPARATIVE EXAMPLES C2-C6
Polypropylene films were extruded and quenched as in Example 1 and Comparative Example 1 to provide non-crystalline mesomorphous polypropylene film (Examples 2-4 and Comparative Example C2) and crystalline polypropylene film (Comparative Examples C3-C6). The films of Examples 2-4 and Comparative Examples C4-C6 were coated with a solution containing 99.9 weight percent N,N-dimethylacrylamide and 0.1 weight percent FC-430 wetting agent. The N,N-dimethylacrylamide was grafted to the films using electron beam radiation at a dose of 0.5, 2, and 5 Mrad. Comparative Examples C2 and C3 were untreated. The films were tested for 180ยฐ peel adhesion when prepared (initial) and after 2 years storage at 70ยฐ F. (21ยฐ C.) with the results set forth in Table III. The tensile properties of the untreated films and those treated with 5 Mrad dose were tested when prepared (initial) and after 4 months and 2 years storage at 70ยฐ F. (21ยฐ C.) with the results set forth in Table IV.
TABLE III______________________________________ Peel adhesion (g/cm)Example Dose (Mrad) Initial 2 years______________________________________C2 0 102 143 2 0.5 169 204 3 2 377 392 4 5 384 375C3 0 127 163C4 0.5 150 225C5 2 257 380C6 5 392 484______________________________________
TABLE IV______________________________________ Yield stress ElongationExample Dose (Mrad) Time (kg/cm.sup.2) at break (%)______________________________________C2 0 Initial 164 700C2 0 4 mo 154 655C2 0 2 yr 172 6204 5 Initial 164 7004 5 4 mo 161 6304 5 2 yr 181 610C3 0 Initial 241 800C3 0 4 mo 252 750C3 0 2 yr 266 620C6 5 Initial 241 800C6 5 4 mo 246 255C6 5 2 yr * *______________________________________ *too brittle to test
As can be seen from the peel adhesion values in Table III, enhanced peel adhesion results from the grafting of the N,N-dimethylacrylamide on the polypropylene films with higher peel adhesion values resulting from higher doses of radiation. The data in Table IV shows that the crystalline irradiated film, Comparative Example C6, has a significant loss in elongation at break after 4 months storage and is too brittle to test after 2 years storage, while the irradiated mesomorphous polypropylene, Example 4, substantially retains its ability to elongate under stress even after a 2-year storage period..
EXAMPLE 5 AND COMPARATIVE EXAMPLE C7
Polypropylene films were extruded and quenched as in Example 1 and Comparative Example C1 to provide non-crystalline mesomorphous polypropylene film (Example 7) and crystalline polypropylene film (Comparative Example C7). Each film was coated with a solution containing 90 weight percent N-vinyl-2-pyrrolidone, 9.9 weight percent trimethylolpropane triacrylate, and 0.1 weight percent FC-430 wetting agent. The N-vinyl-2-pyrrolidone and trimethylolpropane triacrylate were grafted to the films using 5 Mrad electron beam radiation. Grafting was confirmed by iodine uptake. After a period of 1 year, the film of Comparative Example C7 had become brittle and had reduced elongation while the film of Example 5 substantially retained its tensile properties.
EXAMPLE 6 AND COMPARATIVE EXAMPLE C8
Polypropylene films were extruded and quenched as in Example 1 and Comparative Example C1 except that the polypropylene used was Exxon polypropylene 3014 (melt flow index - 12; average molecular weight, by GPC - 161,000) to provide non-crystalline mesomorphous polypropylene film (Example 6) and crystalline polypropylene film (Comparative Example C8). Each film was treated with a solution containing 90 weight percent N-vinyl-2-pyrrolidone, 9.9 weight percent trimethylolpropane triacrylate, and 0.1 weight percent FC-430 wetting agent. The N-vinyl-2-pyrrolidone and trimethylolpropane triacrylate were grafted to the films using 5 Mrad electron beam radiation. Grafting was confirmed by iodine uptake. After a period of one year, the film of Coomparative Example C8 had become brittle with reduced elongation, while the film of Example 5 substantially retained its tensile properties.
EXAMPLE 7-9 AND COMPARATIVE EXAMPLES C9-C12
Melt blown polypropylene microfiber webs having a weight of 50 g/m 2 were extruded, as described in Wente, Van A., "Superfine Thermoplastic Fibers", supra, using Escorene PP 3085 polypropylene polymer (available from Exxon Chemical Americas.) The fiber diameter in the webs was about 5 microns. The extruder conditions were:
Polymer rate (kg/hr/die inch): 0.45
Polymer melt temperature (ยฐC.): 388
Air temperature (ยฐC.): 382
Air pressure (kPa): 55
The webs of Examples 7-9 were quenched with water at a temperature of 40ยฐ F. (4ยฐ C.) and at a rate of 5 gal/hr (19 1/hr) with the spray located 6 inches (15 cm) above the die and directed at the fibers as they exited the die.
The quenched web of Example 7 was analyzed by wide angle X-ray diffraction as shown in FIG. 5 and found to be non-crystalline mesomorphous in structure.
The webs of Comparative Example C9-C12 were not quenched, producing crystalline polypropylene webs. The unquenched web of Comparative Example C9 was analyzed by wide angle X-ray diffraction as shown in FIG. 6, confirming the crystalline structure of the fibers in the web.
The webs of Examples 7-9 and Comparative Examples C10-C12 were treated with a solution containing 15 weight percent acrylic acid, 5 weight percent dichloroethane and 80 weight percent ethyl alcohol to achieve about 10 weight percent solution on the webs. The acrylic acid was grafted to the polypropylene by electron beam radiation at the dose set forth in Table V. The webs were evaluated for energy to stretch to the yield point after two weeks, four weeks, and four months. The results are set forth in Table V.
TABLE V______________________________________ Energy (N-m/cm.sup.3)Example (Mrad) 2 week 4 week 4 mo______________________________________7 1 0.94 0.77 0.488 2 0.85 0.64 0.429 5 0.50 0.39 0.22C9 0 0.43 0.37 0.34C10 1 0.37 0.51 0.28C11 2 0.21 0.28 0.11C12 5 0.10 0.10 0.04______________________________________
As can be seen from the data in Table V, the energy required to stretch the microfiber webs of Comparative Examples C11 and C12 had substantially decreased after four months storage, with the webs of Comparative Examples C11 and C12 not retaining useful tensile properties as evidence by the energy required to stretch the webs to their yield points of 0.11 N-m/cm 3 and 0.04 N-m/cm 3 , respectively. The microfiber webs of Examples 7-9 retained sufficient useful strength after four months storage as evidenced by the energy required to stretch the webs to their yield points of 0.47 N-m/cm 3 , 0.42 N-m/cm 3 , and 0.22 N-m/cm 3 ., respectively.
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Polypropylene articles are provided. The polypropylene articles include non-crystalline mesomorphous polypropylene having olefinic unsaturation-containing monomers graft-polymerized thereon by ionizing radiation in a dosage sufficient to degrade crystalline polypropylene. The irradiated polypropylene articles retain useful tensile properties after storage periods of as long as at least about four months. Further provided is a method for preparing irradiation polypropylene articles having olefinic unsaturation-containing monomers graft-polymerized thereon including the steps of melt extruding polypropylene; quenching the extruded polypropylene immediately after extrusion to provide non-crystalline mesomorphous polypropylene; coating the non-crystalline mesomorphous polypropylene with an ionizing radiation graft-polymerizable monomer; and irradiating the coated non-crystalline mesomorphous polypropylene with a dosage of ionizing radiation sufficient to degrade crystalline polypropylene and sufficient to effect graft-polymerization of the monomer onto the surface of the polypropylene.
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This is a division of Ser. No. 08/162,634 filed Dec. 2, 1993 now U.S. Pat. No. 5,437,260.
REFERENCE TO CO-PENDING DOCUMENT
Reference is had to co-pending disclosure document 288,597, filed August 1991.
TECHNICAL FIELD
The invention relates to a cross bow and more particularly to a cross bow capable of firing arrows, pellets or balls.
BACKGROUND OF THE INVENTION
The invention relates to a cross bow used by people engaged in hunting and target practice in general. Typically, the cross bow is in the form of a bow mounted on a stock in the general form of a rifle. The string of the bow is drawn back to a cocked position and is locked in that position under the control of the trigger until an arrow is fired. The cross bow allows the use of a relatively higher tension for the string as compared to an ordinary bow because both hands are available for cocking or a mechanical device can be used, and once the string is cocked, it remains cocked until it is discharged. An ordinary bow is drawn with a single hand and can only be maintained in a cocked position by physically holding the string in the cocked position.
Even though both hands can be used to cock a cross bow, the cocking procedure is still challenging because it is necessary to maintain increasing tension on the string continuously from the static position to the cocked position. The distance can be about one foot or more. The last portion is the most difficult for the operator because the tension is the highest and it comes immediately after the physical effort to move the string the first eight or more inches so that the arms may be tired by the time the most difficult portion is reached.
There are complex mechanically arrangements available for assisting in cocking a cross bow. These mechanical systems have many drawbacks besides being complex. Such mechanical systems add greatly to the weight of the cross bow or to the weight of equipment the operator must carry around to use the cross bow.
An improved, less physically demanding method and apparatus for loading a cross bow is needed. Such an apparatus should preferably add very little weight to the cross bow and simplify the operation of cocking for the operator.
Prior art cross bows are designed to fire a single arrow and then require recocking and reloading. That is, the cross bows are "single barrel" or single shot bows. It would be highly advantageous to have a "double barrel" cross bow so that two shots could be fired separately as needed. This is particularly beneficial for game hunting where the first shot misses or slightly wounds the game and the rapid firing of a second round is essential for hitting the game or minimizing the pain the game must endure.
Generally, prior art cross bows are limited to firing arrows. There have been cross bows capable of firing pellets and in some cases both pellets and arrows. In addition to firing pellets and arrows, it would be advantageous to fire balls and even bullets, if desired. There is a need for a cross bow with such a diverse capability.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages of the prior art cross bows and provides improvements previously considered outside the scope of operation of a cross bow. In addition, the present invention provides versatility and convenience to the improved cross bow.
As used herein, the term "single barrel" refers to a cross bow which has a single firing system so that it can fire only a single missile at a time.
as used herein, the term "double barrel" refers to a cross bow having two firing systems so that it can fire two missiles sequentially or simultaneously.
It is an object of the present invention to provide a cross bow which is relatively easy to cock without adding any significant weight to the cross bow.
It is another object of the present invention to provide a cross bow which is a "double barrel" cross bow and capable of firing two separate missiles sequentially or simultaneously under the control of the operator.
It is yet another object of the present invention to provide a cross bow which is capable of firing arrows, pellets and balls, selectively.
It is a further object of the present invention to provide a cross bow which is capable of firing balls which are retained and fed into a firing position automatically.
It is yet a further object of the present invention to provide a cross bow including a floating bolt for firing missiles.
Other embodiments, features and advantages of the invention will become apparent upon reading the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of one embodiment of the cross bow according to the invention for a "single barrel" cross bow in its cocked position;
FIG. 2 is a top plan view of the cross bow shown in FIG. 1 with the change that the semi-cocked position is shown in dotted lines;
FIG. 3 is a front end elevation view of the cross bow shown in FIG. 1;
FIG. 4 is a view of the cross bow shown in FIG. 2 along the line 4--4;
FIG. 5 is a view of the cross bow shown in FIG. 1 along the line 5--5;
FIG. 6 is an enlarged fragmentary view of a portion of the cross bow shown in FIG. 4 in order to show details in the operation of the triggering system and the missile ball system;
FIGS. 7-10 are enlarged fragmentary views of the cross bow shown in FIG. 4 and show the changes in components during the sequence of firing a missile from the cross bow;
FIG. 11 a side elevational view of another embodiment of the cross bow according to the invention for a "double barrel" cross bow in its double cocked positions;
FIG. 12 is a top plan view of the cross bow shown in FIG. 11;
FIG. 13 is a front end elevation view of the cross bow shown in FIG. 11;
FIG. 14 is a view of the cross bow shown in FIG. 12 along the line 14--14;
FIG. 15 shows several types of missiles which can be fired from the cross bow according to the invention;
FIG. 16 is a view of the cross bow shown in FIG. 11 along the line 16--16;
FIG. 17 is an enlarged fragmentary view of a portion of the cross bow shown in FIG. 14 in order to show the operation of the triggering system and the missile ball system;
FIG. 18 is an enlarged fragmentary view of another feed system for the cross bow shown in FIG. 17;
FIG. 19 is a side elevational view of another embodiment of the invention shown partially in section;
FIG. 20 is a top plan view of the embodiment shown in FIG. 19 with the cocked bow shown in dashed lines;
FIG. 21 is an end elevational view of the embodiment shown in FIG. 19;
FIG. 22 is an enlarged fragmentary view of a portion of FIG. 19 with portions removed to show the interior;
FIG. 23 is a top plan view of the portion shown in FIG. 21; and
FIG. 24 is a sectional view of FIG. 22 along the lines of 24--24 with portions removed from the bow end to simplify the figure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-10 show one of the preferred embodiments of the cross bow according to the invention. A channel 60 is defined between top main beam 1 and bottom main beam 2 as shown in FIG. 4. Cross bar 17 moves within the channel 60 for firing projectiles as shown in FIG. 5. Muzzle bracket 7 serves to maintain the separation of the main beams 1 and 2, and to stop the movement of the cross bar 17 when a projectile is fired. The muzzle bracket 7 is fixed in place with metal pins 8 riveted to bracket 7. Instead of pins 8, threaded bolts not shown) could be used by screwing them into the bracket 7. Stop bar 18 also operates to maintain the relative positions of the main beams 1 and 2 along with other functions which will described later herein.
Bow 6 is positioned in slot 45 as shown in FIG. 4 and bow anchor bar 44 retains the bow 6 in the slot 45. The anchor bar 44 is rotatably attached to the bottom main beam 2 with a nail 8 at one end and attached to the bottom main beam 2 using bolt 10 which is anchored in the bottom main beam 2 and wing nut 9. A telescope 61 mounted on brackets 62 can be used for increased accuracy. Butt 65 can have a shape in accordance with well known designs.
A main string 3 which is in two parts is attached to the bow 6 at respective horns 11 and the other ends of the string 3 are attached to cross bar horns 21 on the cross bar 17 as shown in FIG. 2. Preferably, the ends of the string 3 attached to the horns 11 have loops for engaging the horns 11 and allowing the easy removal from the horns 11. The stop bar 18 limits the movement of the cross bar 17 so that after reaching a cocked position, there is little additional movement of the cross bar 17.
Cocking of the cross bow shown in FIG. 1 is greatly simplified by the use of a loading string 5. Ends of the loading string 5 are attached to respective bottom bow horns 12. The ends of the string 5 are preferably formed in loops to allow easy attachment and removal from the horns 12. A hook 4 is mounted on the bottom main beam 2 with screws 64 and is positioned to receive the loading string 5 as shown in dotted lines in FIG. 2.
For cocking the cross bow shown in FIG. 4, initially the loading string 5 is pulled back and the loading string 5 is engaged with the hook 4. This results in the bow 6 being bent as shown in dotted lines in FIG. 2 in a half cocked state. Thereafter, the cocking is completed by moving the cross bar 17 further back to engage the trigger mechanism which will be described in more detail hereinafter.
The trigger mechanism is shown in detail in FIGS. 5 and 6. The cross bar 17 is connected to firing bolt 30 which actually engages missiles such as ball 36 for pushing out of the cross bow, that is, for firing. When the cross bar 17 is moved into a cocked position, the firing bolt 30 is moved to a position for cocking bolt 46 to engage it as shown in FIG. 6. The cocking bolt 46 is urged upward by cocking spring 25 which is in the form of a flat spring. The cocking bolt 46 moves within a sleeve 52. One end of the cocking spring 25 is fixed into the bottom main beam 2 with a screw 27. Trigger 26 is positioned in an opening in the cocking spring 25 and includes an arm 26a contacting locking plunger pin 28 in the cocking bolt 46. The trigger 26 is rotatably mounted on pin 26b so that movement of the trigger 26 towards the butt 65 results in the arm 26a pushing the cocking bolt 46 down, thereby releasing the firing pin 30 to propel a missile such as the ball 36.
FIGS. 7-10 show the operation of the trigger mechanism in detail and at different stages of firing the ball 36. In addition, FIGS. 7-10 shows the feeding system for the balls 36 into the firing position. FIG. 7 shows the firing bolt 30 engaged by the cocking bolt 46. A magnet 31 can be used for holding the ball 36 made of a suitable material such as steel in its firing position so that the ball 36 does not roll down the channel 60 accidentally. Balls 24 are stored and fed from a magazine 14. The balls 24 are urged upwards by magazine bolt 23 which is connected to clip magazine spring 50. The magazine 14 is screwed into threaded sleeve head 22 in the magazine locking cap 13 on the bottom main beam 2 as can be seen in FIG. 6. The top of the magazine bolt 23 is rounded and the full expansion of the spring 50 extends the magazine bolt 23 so that the rounded end of the magazine bolt 23 extends slightly into the channel 60 when there are no other balls 24 left. This allows delivery of the last ball 24 and also allows the firing bolt 30 and free float bolt 29 to move over the magazine bolt 23 when other missiles are being fired. The free float bolt 29 is urged against the firing bolt 30 by spring 20 which is attached to the free float bolt 29 by pin 19.
FIG. 8 shows the position of the trigger mechanism almost immediately after the trigger 26 has been moved back to fire the cross bow. The rotation of the trigger 26 around the pin 26b results in the arm 26a moving the cocking bolt 46 to release the free float bolt 29. The free float bolt 30 is shown in a position to the left of its cocked position as shown in FIG. 7. In the new position, the firing bolt 30 prevents any of the balls 24 from moving up and the free float bolt 29 has also moved left due to the expansion of the spring 20. FIG. 9 shows a time event subsequent to FIG. 8 and both the firing bolt 30 and free float bolt 29 have moved further to the left. The adjacent ends of the firing bolt 30 and free float bolt 29 are tapered so that there is a smooth transition as each moves over the balls 24. FIG. 10 is a short time of subsequent to FIG. 9 and shows that the spring 20 expands sufficiently to position the free float bolt 29 over the ball 24 to prevent the balls 24 from moving up. Pin 19 on the free float bolt 29 is stopped by bracket 18. Meanwhile, the firing bolt 30 continues to move left to propel the ball 36.
During cocking, the sequence of events is substantially reversed and the firing bolt 30 is moved to the right of its position as shown in FIG. 10 past its positions shown in FIG. 9. The movement continues past FIG. 8 until its position shown in FIG. 7 which allows a new ball 36 to become engaged by the magnet 31 and for the trigger 26 to become engaged for firing.
FIGS. 11-14 and 16-18 show other embodiments of the invention. FIG. 11 shows a side elevational view of a double barrel cross bow according to the invention with both barrels cocked. A channel 160 is defined by the top main beam 101 and middle main beam 201 while channel 160' is defined by the middle main beam 201 and bottom main beam 102. Cross bars 117 and 117' move in respective channels 160 and 160' for cocking and firing missiles. Muzzle bracket 7 stops the movement of the cross bars 117 and 117' and maintains the positions of the beams 101, 201 and 102 relative each. The muzzle bracket 7 is attached to the beams 101, 201 and 102 with pins 8.
Bow 106 is mounted on the bottom main beam 102 in a slot and maintained in the slot with bolt 203 as shown in FIG. 14. Similarly, bow 106' is mounted on the bottom main beam 102 in its own slot and maintained in the slot with bolt 202 as shown in FIG. 14.
Main string 103 has two parts; one end of each part is attached to respective top bow horns 111. The other end are attached to respective cross bar horns 121 on cross bar 117. Similarly, main string 103' has two parts; one end of each part is attached to respective to bow horns 111' while the other ends are attached to respective cross bar horns 121' of cross bar 117' as shown in FIG. 12.
As in the embodiment shown in FIG. 1, each of the bows 106 and 106' can be cocked using a loading string (not shown). For the bow 106, the loading string would be attached to bottom bow horns 112 while for the bow 106', the loading string would be attached to the bottom bow horns 112'. Hooks 104 and 104', respectively, are used for cocking the bows 106 and 106'. The hooks 104 and 104' are attached to beams 101 and 102 respectively with screws 164 as shown in FIG. 11.
Butt 165 can have any suitable shape such as known in the prior art. A telescope 161 supported by brackets 162 can be used to improve accuracy.
Preferably, the bow 106' is cocked first and then the bow 106 is cocked. Either bow can be fired first. The cross bars 117 and 117' are shown in the cocked positions in FIGS. 11-13. FIGS. 14, 16, 17 and 18 show details of the trigger mechanism suitable for each of the "barrels" as well as feed systems for missiles.
Trigger 126 has an arm 126a and rotatably mounted on a pin 126b. Similarly, trigger 126' has an arm 126a' and is rotatably mounted on a pin 126b'. The arms 126a and 126a' are urged upward by respective pins 128 and 128' mounted on respective cocking bolts 246 and 146 which are being pressed by flat springs 125 and 125' respectively. The triggers 126 and 126' are positioned in openings of the respective flat springs 125 and 125'. The flat spring 125 is attached to the bottom main beam 102 with screw 127 while the flat spring 125' is attached to the bottom main beam 102 by screw 127'. The cocking bolts 146 and 246 move within sleeves 152 and 252, respectively.
Magazine 114 as shown in FIG. 17 is similar to the magazine 14. Balls 124 are urged upward by magazine bolt 123 which is attached to spring 151. The magazine 114 is screwed into threaded sleeve head 122 in the magazine locking cap 113 and magazine retainer cap 115 closes the bottom of the magazine 114. A magnet 131' holds a ball in its firing position.
FIG. 18 shows another magazine 214 similar to magazine 114 but without the magazine bolt 123 and the spring 151. The magazine 214 using a gravity feed system, rather than a spring driven feed system. For magazine 214, a ball 124 is positioned for firing by turning the cross bow upside down so that gravity causes the balls to move towards magnet 131'. Returning the cross bow right side up results in a ball 124 being held by the magnet 131' as shown in FIG. 18.
The feed system shown in FIG. 17 for the channel 160 of the top bow 106 is yet another embodiment. Pellet retaining spring 33 is mounted on the top main beam 101 as shown in FIG. 17. One end of the retaining spring 33 is attached to the top main beam 101 with screw 33b which allows tab 33a to be used to lift the other end of the retaining spring 33 out of the slot 231 so that missiles such as balls pellets and bullets can be loaded. Magnet 131 is positioned to hold a single ball in a firing position. as shown in FIG. 17, four balls 124 have been loaded to enable the cross bow to shoot all four balls at one time, thereby providing a scatter shot like a shotgun.
The firing system for the lower cross bow 160' is similar to the firing system in the single barrel embodiment shown in FIG. 1. Firing bolt 130 is cocked by moving the cross bar 117' back until cocking bolt 146 engages the slot in firing bolt 130 as shown in FIG. 17. When the trigger 126' is pulled back, the cocking bolt 146 is released and free float bolt 129 is pushed forward by spring 120 so that the free float 129 covers the feed for the magazine 114 to prevent an additional ball 124 from moving up to the magnet 131'.
The free bolt 129 is positioned in a slot defined in cocking bolt 246 so that the cocking bolt 246 stops the movement of the free bolt 129 after firing as in the case of pin 19 and bracket 18 for the embodiment shown in FIG. 1.
The triggering mechanism for the upper cross bow 106 is simple in its arrangement and operation. Firing bolt 230 is cocked by moving the cross bar 117 back until the firing bolt 230 engages the cocking bolt 246 as shown in FIG. 17. pulling trigger 126 back releases the firing bolt 230. No free floating bolt is needed in this arrangement. Thus, this is a less expensive embodiment to manufacture.
FIG. 15 shows several types of missiles which can be used with the cross bows according to the invention. The diameter of the missiles should be compatible with the dimensions of the bore of the cross bow such as channel 60. Preferably, the overall diameter of the missile should be slightly less than the diameter of the bore so that the missile moves freely, but not so that the missile can rattle. As indicated, the bore can be rifled to improve the accuracy of firing bullets. A single blade broad head arrow 49 includes parallel fletch 48 and an arrow butt cap 47 which is attracted by a magnet. The arrow 49 is loaded by sliding it down the firing channel such as channel 60 in FIG. 4. When the crossbow is cocked, the arrow 49 can be moved down the channel 60 until the arrow bolt cap 47 is attracted to the magnet 31. The loading of the ball 36 has been discussed already. Bullet 37 and air gun pellet 38 are particularly suited for firing from an arrangement shown from the upper barrel, channel 160, shown in FIG. 14. The retaining spring 33 prevents these objects from inadvertently falling down the channel 160.
FIGS. 19 to 24 show another embodiment of the invention showing a single shot bow for firing bullets, air gun pellets, or the like. The missile to be fired is loaded prior to arming or cocking the bow in contrast to conventional bows. Another feature of this embodiment is that the portion of the driving element for the missile does not contact the interior of the barrel so that rifling is not degraded at all by the driving element. Other important features will also become apparent.
FIG. 19 shows a side elevational view of the cross bow 300 with portions removed to reveal interior components. A barrel 301 has a stiffening bar 302 attached to it to maintain the integrity of the structure of the barrel 301. The stiffening bar 302 can be attached to barrel 301 by bonding, or mechanically, or made integrally, or through other known techniques. Stock 316 is attached to the stiffening bar 302 at the front portion 303 with threaded bolts 304. Bow 320 as shown more clearly in FIGS. 20 and 21 is locked into anchor assembly bow slot 337 with flat plate 309 and threaded bolt 310. Front sight 318 is attached to the front of the cross bow 300 in a conventional manner. A firing slot 317 is defined along the length of the barrel 301.
A trigger guard 306 as shown more clearly in FIG. 22 is attached by threaded bolts 331 to the front portion 303. Trigger 307 is rotatably mounted by pin 332 and has a slot 333 engaging pin 334 which is mounted on triggering bolt 308. Movement of the trigger 307 back towards the stock 316 results in the generally linear movement of the trigger locking bolt 308 downward in a slot not shown. Flat spring 305 tends to maintain the trigger 307 forward so that the trigger locking bolt 308 is urged upward.
A removable bracket assembly 314 is attached with threaded bolt 315 and supports rear sight 325 and loading string hook 323. Firing bolt 324 can be seen clearly in FIGS. 22 and 24. The firing bolt 324 has front firing bolt hook 312 and rear firing bolt hook 313. Firing string 322 as shown in FIG. 20 can be engaged between the hooks 312 and 313, and loading string 321 can be engaged by hook 323. The firing bolt 324 has a firing bolt rider portion 338 extending downward into the slot 317 to firing bearing portion 327 which can contact and propel a missile such as bullet 328. The firing bolt 324 has a portion 324a connected to slides 330. The slides 330 engage and move in slide rails 329 which are mounted on the frontal portion 303 of the stock 316. As can be seen in FIG. 22, the firing bearing portion 327 has a smaller diameter than bore 336 so there is no contact, hence no mutual wear.
Loading of the bow 300 is by manually moving the firing bolt 324 back to expose loading port 326. The bullet 328 or air gun pellet is positioned through the port 326 and then the firing bolt 324 is moved fully forward to push the bullet 328 to be engaged by the rifling of the bore 336. The rifling prevents the bullet 328 from falling through the bore 336. As the firing bolt 324 is moved forward, the trigger locking bolt 308 is pressing upward and engages a locking slot which prevents further movement forward until the trigger 307 is released.
The firing string is attached to firing string horns 335 in a conventional manner. The bow 320 has hooks 319. These hooks 319 can be attached to the bow 320 or molded into the bow 320. The loading string 321 engages the hooks 319 with relatively large loops 319a to enable easy removal after the cross bow 300 has been cocked.
To use the cross bow 300, a bullet 338 is dropped into port 326 and the firing bolt 324 is moved forward so that the trigger locking bolt 308 becomes engaged in the firing bolt 324. Subsequently, loading string 321 is engaged into the hooks 319 and the bow 320 is bent so that the loading string 321 can be engaged into hook 323. Thereafter, firing string 322 is engaged into the space between the firing hooks 312 and 313, thereby allowing the loading string 322 to be removed easily.
Firing the cross bow 300 results in the firing bolt rider portion 338 moving along the slot 317 while slides 330 move in the rails 329.
One of the significant features of the embodiment shown in FIGS. 19-22 is a novel raised beam bow. The raised beam allows in-line string firing of the firing bolt 324 due to the firing string ends being at substantially the same level as the firing bolt notch between hooks 312 and 313. This arrangement prevents downward pressure on the firing bolt 324 on the slide portion of the barrel, as in prior art cross bows. Thus, there is relatively little pressure on the slides 330 in the rails 329 so more force is applied to the missile 328 due to reduced friction, resulting in very high speed as the missile leaves the cross bow.
There has been described novel crossbows. It is evident that those skilled in the art may now make numerous uses and modifications of and departures from the specific embodiments described herein without departing from the incentive concepts. Consequently, the invention is to be construed as embracing each and every feature and novel combination of features present or possessed by the crossbows herein disclosed and limited solely by the spirit and scope of the appended claims.
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A crossbow for shooting projectiles includes a frame with flexible bow arms and a bowstring connecting the arms, a trigger assembly for retaining the bowstring in a cocked position and releasing to propel the projectile, and a hollow barrel with interior rifling into which projectiles are loaded and through which they are expelled. A firing bolt is connected to the bowstring and located in the barrel to transfer force from the bowstring to the projectile. In the prior art, such firing bolts contact the barrel interior, resulting in friction and wear of the rifling. In this invention, the barrel includes an elongated slot (317) therealong. The firing bolt (324) is slidably supported on rails (329) on the exterior of the barrel. The firing bolt includes a driving member (338, 327) which extends through the slot to contact the projectile, but does not contact the barrel interior walls, thus propelling the projectile without causing friction and wear within the barrel.
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BACKGROUND OF THE INVENTION
1. Field of the Invention:
The invention relates broadly to abrading tools and more specifically to electrically powered abrading tools used in automobile body repair work, and the like.
2. Description of the Prior Art:
A variety of electrically powered abrading tools are known to the trade. It is also known to provide a portable abrading tool driven by a hand electric drill. More specifically, the art has provided an electric hand drill driven split cylinder adapted to be expanded to receive and tightly grip a cylindrical abrasive sleeve. Representative prior art is found in U.S. Pat. Nos. 819,578, 2,554,763 and 3,381,418, all of which are concerned with portable abrading tools powered with an electric drill. Other U.S. patents related to this general subject matter include U.S. Pat. Nos. 2,853,838, 3,510,989 and 3,596,411.
In spite of the very substantial interest among body shop operators to have an abrading tool which can be quickly connected to and used with an ordinary electric hand drill without impairing the normal purposes of the hand drill, such an apparatus has not come into wide-spread use in the trade. More expensive types of abrading tools in which the motor unit and abrading unit are designed as a unified electrical apparatus are available but such devices generally have no utility except for abrading. One of the primary deficiencies in the prior art is believed to be the fact that abrading tools designed to be driven by an electric hand drill have not provided a practical means for expanding and contracting the driven cylinder over which the abrading sleeve is placed. Therefore, prior art abrading tools driven by electric hand drills have not come into popular use even though there is a strong demand for such a tool.
SUMMARY OF THE INVENTION
The apparatus of the invention is directed to an abrading tool primarily intended for use in body shop repair work. The abrading tool constitutes a driven cylinder which is connected through a universal joint arrangement to the chuck of an electric hand drill and a bracket extends between the tool and a bearing support such that the tool of the invention can be both driven and supported by an electric hand drill. Further, the tool can be quickly removed from the electric drill when the electric drill is needed for its normal drilling purposes.
The drill chuck is connected through the mentioned universal joint to a driven shaft which mounts an elliptical cam. The shaft extends from its driven end through and slightly beyond an opposite end of a split, i.e., longitudinally slotted, cylinder. The split cylinder is adapted to receive a cylindrical abrading sleeve which can be tightened and loosened on the driven cylinder by expanding and contracting the split sleeve portion of the driven cylinder. The tool also mounts at the end opposite the drill driven end a pivoted handle such that the tool in use can be held at one end by this handle and at the opposite end by the electric drill handle. In operation, the elliptical cam is rotated to a position which allows the driven cylinder to contract and an abrading sleeve to be placed over the driven cylinder. When the electric drill is energized, the cam is brought in contact with bearing surfaces within the driven cylinder which causes the cylinder to expand, causes the abrading sleeve to be tightened on the driven cylinder and allows the driven cylinder and its mounted abrading sleeve to be driven by the electric drill for abrading. When this abrading sleeve has become worn, the operator rotates the cam relative to the driven cylinder and brings the cam into a position which allows the driven cylinder to contract and the worn abrading sleeve to be removed for purposes of replacement.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an abrading tool according to the invention as it appears ready for use.
FIG. 2 is a cross section view through the tool with the electric hand drill being shown in dashed lines and the expanded position of the abrading sleeve exaggerated and also shown in dashed lines.
FIG. 3 is a partially cutaway sectional view showing the bearing and cam details of the invention apparatus.
FIG. 4 is a side view of the drive shaft employed in the invention apparatus.
FIG. 5 is a sectional view of the split cylinder employed to support the abrading sleeve.
FIG. 6 is an end view taken in the direction 6--6 of FIG. 5.
FIG. 7 is an end view taken in the direction 7--7 of FIG. 5.
FIG. 8 is an end view of the cam employed to expand the driven sleeve.
FIG. 9 is a side view of the cam.
FIG. 10 is a somewhat schematic view showing the auxiliary handle positioned for removing a used abrading sleeve which is indicated in dashed lines.
FIG. 11 is a side view of the bearing bracket assembly used to support the tool from the drill.
FIG. 12 is a partial cross section taken through an abrading sleeve of the type employed with the invention apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The abrading tool to be described is designed to be operated by a conventional hand drill 20 having a conventional chuck 21 and a front housing 22 having a threaded aperture 25 adapted to receive a bolt 23 for securing a bent bracket 24. While many electric drills will provide the front housing threaded aperture 25 suited to act as a point of attachment for the tool of the invention, such an aperture, i.e., aperture 25, can be readily formed on the front housing if not already part of the drill as originally manufactured. Bracket 24 may be formed of a bent metal strip and is integrally secured to a bearing 30 having a hub portion 31 and a flange portion 32.
A universal joint 35 has a spindle portion 36 which is received by the chuck 21 and at the opposite end has a socket portion 37 which is secured by a pin 38 which passes through a hole 39 which is provided in a reduced end portion 40 of drive shaft 41. Shaft 41 is rotatably received in the previously mentioned support bearing 30 and resides between socket 37 and a cam 50. Cam 50 has a somewhat elliptical camming disc portion 51 and a hub portion 52 which receives shaft 41 and is pinned to shaft 41 by a pin 55 which extends through a hole 56 provided in shaft 41 and holes 57 in hub 52 of cam 50.
On the opposite end of shaft 41 there is mounted an auxiliary handle 60 having a pivotal pin connection 61 to a bearing 62 which receives the extreme end portion of shaft 41. A suitable locking ring 63 retains bearing 62 on shaft 41. Shaft 41 is further held in position by a sleeve 70 which is secured to shaft 41 by a set screw 71. The abrading sleeve 75 mounts on a split thin walled, metal cylindrical sleeve 80 having a pair of longitudinal slots or slits 81, 82 extending from its driven end over a major portion of its length. While two slots are preferred, one slot can be used. The width and length of slots 81, 82 and the wall thickness and metal used for sleeve 80 are chosen to give sleeve 80 the necessary contraction and expansion capability as will be readily understood. Cylinder 80 is closed at its outermost end by a thin walled washer 85 having an aperature 86 through which passes shaft 41. Washer 85 is secured to cylinder 80 and resides between bearing 62 and sleeve 70. Within cylinder 80 there are mounted two oppositely disposed curved bearing plates 87, 88. Sleeve 80 is expanded by rotating the cam 50 until the camming surfaces indicated at 90, 91 come into full contact or approximately full contact with the bearing plates 87, 88. That is, the dimension W in FIG. 8 is designed such that when dimension X in FIG. 7 equals dimension W in FIG. 8, the cylinder 80 will be fully expanded and will firmly grip the abrading sleeve 75. It should also be noted that dimension Y, that is, the internal diameter of abrading sleeve 75, is selected such that when dimension X is increased to dimension W the abrading sleeve 75 will be sufficiently tightened on cylinder 80 to hold its position. Since abrading sleeves as such are well known, it is believe that those skilled in the art can readily select a particular type of abrading sleeve whose strength, wall thickness, and internal diameter are suited to the invention. Alternatively, when cam 50 is rotated a sufficient amount to bring surfaces 90, 91 out of contact with bearing plates 87, 88, cylinder 80 may contract which allows the used abrading sleeve 75 to be removed and replaced by pivoting auxiliary handle 60 as schematically indicated in FIG. 10.
In summary, it can be seen that there is provided a relatively inexpensive abrading tool accessory for an ordinary electric tool and which provides an ease of abrading sleeve replacement not previously found in the prior art.
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A portable abrading tool useful in automobile body work, and the like, embodies a hollow expandable cylinder which is adapted to receive an expandable and disposable cylindrical abrading sleeve and be driven by and secured to an electric hand drill. A unique structure for expanding and contracting the driven cylinder facilitates quick replacement of the abrading sleeve.
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BACKGROUND OF THE INVENTION
The instant invention relates generally to the perchlorethylene recovery process for dry cleaning equipment, and more specifically on an improvement in both conventional equipment and the method for the dry cleaning of fabric. The instant invention to be described is more efficient and recovers a larger percentage of perchloroethylene dry cleaning fluid (which hereinafter will be referred to sometimes as perc in this application).
Numerous dry cleaning systems with solvent recovery have been provided in the prior art that adapted to recover their cleaning solvent. For example, U.S. Pat. Nos. 3,728,074 Victor, 3,775,053 Wisdom, and 4,086,706 to Wehr all are illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they are not the same, and are not be suitable for the purpose of the present instant invention as hereafter described.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide a perchlorethylene recovery process for dry cleaning equipment that will overcome the shortcomings of the prior art devices.
Another object is to provide a perchlorethylene recovery process for dry cleaning equipment in which virtually all of the perc is recovered from the process.
An additional object is to provide a perchlorethylene recovery process for dry cleaning equipment in which the operator does not breath nor is exposed to perc fumes or even other wise exposed to the perc in almost any way.
A further object is to provide a perchlorethylene recovery process for dry cleaning equipment which eliminates all odors from the fabric being cleaned and does not compromise but rather enhances the quality of the cleaning process and the degree to of cleanliness of the fabric.
A yet further object is to provide a perchlorethylene recovery process for dry cleaning equipment in which the normal dry cleaning filtering cartridges are left so entirely free of perc that these cartridges can be discarded with regular trash without any health to the general public at large etcetera.
A yet still further object is to provide a perchlorethylene recovery process for dry cleaning equipment which utilizes a same steam sweep system for stripping both the still and filtering cartridges.
Yet still further additional object is to provide a perchlorethylene recovery process for dry cleaning equipment which typically improves the ratio of perc to fabric cleaned from typically 20,000 lbs of fabric to about 70,000 lbs of fabric per 50 gallon drum of perc.
Yet another object is to provide a perchlorethylene recovery process for dry cleaning equipment that is simple and easy to use for those skilled in the art.
A still additional further object is to provide a perchlorethylene recovery process for dry cleaning equipment that is economical in cost to manufacture.
Further objects of the invention will appear as the description proceeds.
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 and described within the scope of the appended claims.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The FIGURE in the drawing is briefly described as follows:
The FIGURE is a block diagram of a typical dry cleaning fabric processing system with the added components to improve the process shown enclosed in dotted lines.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order that the instant invention be more clearly understood a description of parts of the conventional portion of the process will be explained but as a precursor to the understanding of the instant invention, and before examining the instant invention it is desirable to review what is involved in the ordinary dry cleaning cycle.
To start with the objective is to separate the dirt from the the fabric textiles and or garments to be cleaned. To do this the fabric or clothes are tumbled in the dry cleaning solvent perc much in the same way that clothes are washed in a conventional washing machine. However perc is a relatively expensive commodity, and is injurious to both the environment and the health of the operator. It is therefore desirable to reclaim or recycle as much dirty contaminated perc as possible and keep it as a permanent working fluid within the dry cleaning processing system and equipment for use over and over again and again.
To re-process the dirty contaminated perc there are several processes which are performed in a conventional system and generally in the following order:
1. Water is separated from the perc;
2. The perc is distilled; and
3. The perc is filtered in a cartridge.
The system conventionally includes the required valves, sight glasses, pumps, etcetera so that perc in various stages of cleanliness can be diverted back into the cleaning cycle as may be reasonably required at a particular point in a cycle. For example it would be very poor economy to use absolutely clean perc to begin or even continue a cycle wherein the cloth or fabric were quite dirty. Conventionally clean perc would most likely be saved for final rinses.
However there are two places in the perc reclaiming process in which perc is not salvaged in the conventional scheme of the cycle, which are as follows:
1. It seems that after the perc has been recycle several times there is a small amount of perc (approximately 1 lb.) which must be discarded from the water separator, or else the fabric or clothes take on an unpleasant odor.
2. When the filter cartridges are to be discarded because they are completely spent and can not accept any more contaminate there is always a certain amount of perc (approximately 12 lbs.) left in each cartridge at the time the cartridge is discarded.
It is at these two points in the cycle wherein the instant invention corrects the situation and recovers entirely the perc which is otherwise lost in the conventional dry cleaning process and equipment.
Having thus described substantially the nature of the of the loss involved in reclaiming perc in a conventional system a more detailed description of the instant invention will follow.
Turning now descriptively to the drawing is seen a figure which represents a block diagram of a typical dry cleaning process system with the addition of extra components enclosed in dotted contours 10 and 12 so as to create the more efficient perchlorethylene recovery process of the instant invention.
A conventional rotating drum tumbling mechanism 14 is shown in which fabric quite often which is in the form of conventional street clothes or other dry good which might be around a house of the general public, is present and available for the operator to place such items which are to be cleaned. Dry cleaning solvent fluid perc may be caused to be transferred into the drum 14 by pump 20, and valve set 22, 24, & 26,from work tank 16, or rinse tank 18 as may be required at a particular point in a cleaning cycle.
A circulated portion of the volatile fluids (water, perc & air) may be removed from the cycle by fan motor and duct assembly 28 to heat pump and condenser 30, some of which is caused to flow into a water separator 32, where it is freed from water and allowed to flow back to rinse tank 18 via path 42, along with clean perc from condenser 34. At a point in the cycle when the perc is too contaminated to be used for cleaning purposes, it is caused to flow into still 36 so that it can be returned to the cleaning cycle via paths 38, 44 and condenser 34 previously mentioned. Perc which is some what contaminated but is still useable for cleaning may be returned to work tank via path 40.
Perc which is contaminated to such a sufficient degree may be pumped directly to filter cartridges 46, via path 48, valve 50, and pump 20 previously mentioned, and then returned either directly to the drum 14 via path 52, and valve 54, or to still 36 via path 56, and valve 58 as a particular cleaning cycle may require.
After perc has been recycle several times that is so many gallons per so many kilo pounds of clothes cleaned separator 32 is drained of perc which is colected in container 60, but instead of discarding as is normally done in a conventional dry cleaning system this slightly contaminated perc is returned to still 36 either by a optional pump 62 via path 64, or by physically taking container 60 and dumping the contents therein into funnel 66, while opening valve 68. In any case the important consideration is that the perc is returned to the system at a point where it will be distilled again by still 36.
Because the conventional operation of the still component 36 has not been discussed it is appropriate to do so at this point in the examination of the scheme of things.
Normally contaminated perc enters the still 36 from path 56, and in the instant invention also from path 64, and is boiled of to a high degree in a conventional manner by heat supplied by hot steam from boiler 72, to heat exchanger 70. The boiled off perc leaves the still 36 and is returned to the cleaning cycle via path 38 as previously described. At some point in this portion of the perc reclaiming cycle the still will become sufficiently loaded with muck/high concentrated contaminate and perc mixed together wherein the concentration of muck is so high that the distillation process is no longer effective or efficient.
In order to efficiently reclaim the perc from this highly contaminated state live steam is normally allowed to enter the still 36 via path 74 and valve 76, dissolve and mix with the perc and re-condense in perc condenser 34, while excessive water is dumped in sewer or bucket 80. This portion of the process is commonly referred to in the art as sweeping the still and must be regularly carry out by the operator of the system.
When the filtering cartridges are determined to be filled to capacity with contaminate so as to longer be useful in the conventional system they are removed, discarded, and replaced with fresh cartridges. It is to be noted that every time the cartridges are replaced a significant amount of perc remains left in each cartridge, and is there by lost from the system. It might also be noted that there are laws which require that these cartridges be returned to a depot where they may be correctly and properly disposed of so as to not damage the environment or be so hazardous to the operator's health.
A feature of the instant invention is that the same steam that is used to sweep the still 36, on particular occasions when it is required to discard a set of filter cartridges 82 or 46, can be first diverted to flow through a set of filter cartridges 82 or 46 and then to the still 36. What occurs is that the live steam dissolves and mixes with all of the perc which would otherwise remain in a discarded filter cartridge and transfers this otherwise lost perc back into the still sweep reclamation cycle previously described, leaving the spent cartridges 82 or 46 as the case might be completely stripped and void of any measurable amount of perc whatsoever, and all without even any hint of extra cost in operating this system. An optional steam restricting element 88 appears to make both stripping process more efficient.
A set of valves 84a, 84b, 84c & 84d are ganged together by linkage 86 so that two separate set of filter cartridges 82 and 46 may be kept connected to the system so that a fresh set may be immediately switched into a cleaning cycle while a spent set is being stripped of any perc.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing from the spirit of the invention.
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A method for a perchlorethylene recovery process for dry cleaning equipment in which virtually all of the perchlorethylene is recovered from the process so as to increase the economic efficiency of the system while at the same time reducing the hazardous to both environment and the operator's health.
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BACKGROUND OF THE INVENTION
[0001] The traces remaining on the surface of the sensor during normal use of capacitative fingerprint sensors can, in many instances, create an after-image of the fingerprint if manipulated in the right way. This can be of such high quality that it is accepted by the image processing unit and provides characteristics that can be evaluated. In some circumstances, these may correspond to the last finger applied and may result in false acceptance.
[0002] In the case of known methods or sensors, the list of characteristics of consecutively captured fingerprints must not exceed a defined degree of similarity. For example, it is required that images must differ from one another by a minimum amount in terms of translation and rotation. Together with suitable user prompting, this requires the user to always present the finger in a new position for each request procedure. A main memory and local peripherals of a data processing device are used as a memory for the list of characteristics most recently determined by the sensor.
[0003] The present invention seeks to improve latent image rejection in an authentication method as referred to above.
SUMMARY OF THE INVENTION
[0004] Accordingly, the present invention provides an authentication method with biometric characteristic data, particularly biometric characteristic data obtained from finger prints, wherein the characteristic data is captured at least twice for every authentication request, and a change of position between consecutive captures is evaluated and rated.
[0005] In an embodiment of the method, evaluating the change of position takes the form of a direct comparison of the characteristic data.
[0006] In a further embodiment of the method, in order to evaluate the change of position, the position of a sensor fixed point is projected out of the characteristic data and the orientation thereof is recorded.
[0007] Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the Figures.
BRIEF DESCRIPTION OF THE FIGURES
[0008] FIG. 1 shows the sequence of the method according to the present invention.
[0009] FIG. 2 shows a variant for determining the position of a fingerprint in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The authentication method according to the present invention is based on the principle illustrated in FIG. 1 , whereby following successful recognition the same finger is repeatedly presented until sufficient differences exist in the relative orientation.
[0011] Accordingly, in the authentication method according to the present invention, there is no need to store the characteristics or characteristic data most recently determined.
[0012] In phase P 1 characteristic data is extracted as normal from the fingerprint image captured and is compared, depending on the scenario, with an individual reference, in a verification, or an archive of references, in an identification. A capacitative fingerprint sensor is used, for example, to capture the fingerprint.
[0013] If the identification is positive, the system switches to phase P 2 , in which the steps referred to previously are run through cyclically until the relative offset (dx,dy) and/or the relative rotation d(p exceed predefined minimum values or a timeout occurs.
[0014] In this connection, it should be noted that phase P 2 can always be performed as a verification in consequence of the knowledge of the identity in question. Phase P 2 is thus independent of the size of the archive. This is particularly advantageous in the case of less powerful hardware, such as in the case of embedded systems, when a real-time-capable response behavior appears essential for usability.
[0015] There are, in principle, two options for rating the relative orientation:
A first variant provides for a direct reference to be created between the request prints captured and the characteristic data obtained therefrom. A second variant, as shown in FIG. 2 , entails projecting a fixed point on the sensor, such as, for example, the sensor mid-point indicated by a direction arrow, into the coordinates system of the reference and rating the relative orientation in the reference area.
[0018] The second variant can be categorized as more general, since it functions even when the offset is relatively large, whereas in the case of the first variant it is possible, in some circumstances, that a reference no longer can be created. However, in the absence of any reference, a sufficient offset can be assumed.
[0019] Depending on the preference of the user, there are various sequences of motions in order to selectively vary the position of the finger on the sensor. โShifted Double Clickโ (SDC) is a slight adaptation of a sequence of motions which is familiar to all computer users who use a computer mouse. Alternatively, it is possible to rotate the finger slightly, or if the pressure is reduced to move the finger directly on the sensor.
[0020] The authentication method according to the present invention provides the following advantages compared to previous solutions:
Shifted Double Click (SDC) as against a comparison with a latency template of the most recently determined characteristics, stored in non-volatile manner.
[0022] Firstly, with SDC it is no longer necessary to store a latency template permanently. This is particularly advantageous in the case of client-server applications, where given that a number of terminals are operated simultaneously, the effort needed to administer the individual latency templates is no longer required. For security reasons as well, it would seem to be preferable to leave as few traces as possible behind in respect of the last identification procedure. Furthermore, with SDC the sequence of motions becomes a permanent part of the identification procedure and, thus, is more familiar to the user than sporadic requests to apply the finger once again in an offset position.
Shifted Double Click (SDC) as against applying a different finger following each successful identification.
[0024] An advantage here is that each user (among other things, for reasons of familiarity) preferably applies a particular finger. In addition, the next time a person logs on, he/she often cannot remember which finger he/she applied the last time. If account is also taken of the fact that a finger may be temporarily unusable, perhaps because of injury, the system needs to learn one finger more than in SDC, with the same failsafe security.
[0025] Finally, the method according to the present invention helps to reduce the risk of a false acceptance of an unauthorized user.
[0026] Since a false acceptance often occurs only in connection with a particular segment of an image, varying the position and, thus, the segment of the image observed reduces the probability of false alarms. There is no risk of an increase in the false rejection rate since the user has the opportunity of moving his/her finger slightly within a reasonable period of time.
[0027] Although the present invention has been described with reference to specific embodiments, those of skill in the art will recognize that changes may be made thereto without departing from the spirit and scope of the present invention as set forth in the hereafter appended claims.
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An authentication method is provided for biometric characteristic data, especially characteristic data taken from finger-prints. The characteristic data is captured at least twice for each authentication request, and a position alteration between successive captures is evaluated and rated.
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BACKGROUND OF THE INVENTION
The present invention relates to recycling and more particularly to the recycling of diverse pulp and paper products to provide a homogenous cellulosic feedstock having a plurality of beneficial uses.
Fossil materials are finite natural resources, and these materials are rapidly being consumed. The world is also facing many environmentally significant problems associated with the depletion of fossil materials, particularly petroleum, for the production of energy and petrochemicals. A variety of solid, liquid, and volatile organic compounds associated with petroleum extraction, transport, refining, and manufacturing operations have been and are continuing to be released into the environment. However, the most significant environmental factor is the release of carbon dioxide into the atmosphere during the burning of fossil fuels.
The use of fossil fuels has added tremendous quantities of carbon dioxide to the atmosphere. Since this carbon dioxide is being released from fossilized biomass long since effectively removed from the biosphere, there is currently insufficient plant life on earth to consume all of the carbon dioxide being produced. Therefore, the percentage of carbon dioxide in the atmosphere is increasing. Carbon dioxide and other โgreenhouse gasesโ (e.g., volatile organic compounds) allow high energy, short wave length solar radiation to penetrate the atmosphere and to transfer heat to the earth's surface, but the same gases impede the low energy, long wave length radiation that dissipates the absorbed heat from the earth. Thus, heat from the sun is trapped in the earth's atmosphere, which is known as the โGreenhouse Effect.โ Reduction or elimination of the use of fossilized carbonaceous materials as combustion fuels would halt and possibly reverse current trends in altering the biosphere. The use of renewable biomass as a replacement for fossilized combustion fuels is a formidable task, but it is an environmentally beneficial task that is well worth the effort, especially when considering the long term effects of continuing current trends.
Another environmental concern facing today's earth is the production and disposal of waste, including municipal solid waste (MSW). The ability to recycle such waste productively and efficiently could significantly reduce the current volume of unused and discarded waste.
Municipal solid waste (MSW) includes, but is not limited to, cellulosic and/or noncellulosic materials such as office wastes, business wastes, institutional wastes, industrial wastes, residential wastes, pulp and paper products, inks, glues, plastics, glass, metals, food wastes, and yard wastes. Within MSW, the cellulosic component (e.g., pulp and paper components) accounts for a relatively large portion of MSW. Therefore, there has been a particular need to try to recycle and utilize the pulp and paper components to reduce the amount of MSW.
Many attempts have been made to use MSW for energy production in so-called resource recovery facilities. Some such facilities incinerate the MSW without any prior separation of potentially recyclable materials, with the possible exception of curb side or drop-off source recycling, to produce steam and/or electricity. These facilities are known as mass-burn incinerators, which are very expensive to site, permit, construct, and operate, in addition to producing large quantities of hazardous or toxic gases and airborne particulates, as well as large quantities of hazardous or toxic fly ash and sometimes bottom ash that must be landfilled. Some other such facilities use MSW that has been shredded with some non-combustibles subsequently removed prior to incineration for energy recovery, which are known as refuse derived fuel (RDF) incinerators. RDF incinerators tend to emit lesser amounts of hazardous or toxic air pollutants and to produce lesser amounts of hazardous or toxic ash than mass-burn facilities. Still other facilities use a combination of manual labor and mechanical devices to separate recyclable materials from the MSW, which are known as MSW materials recovery facilities (dirty MRFs). The non-recyclables from dirty MRFs are usually shredded and incinerated either on-site or off-site for energy recovery. The incinerator fuel from dirty MRFs produce lesser amounts of air pollutants and ash than either mass-burn or RDF incineration facilities. Some attempts have also been made to cap and recover the gases from MSW landfills for energy production. Landfill gas recovery and use does reduce the emission of greenhouse gases that would otherwise be emitted to the atmosphere, particularly volatile organic compounds from household and industrial chemicals in MSW and methane and carbon dioxide from anaerobic digestion of the putresible materials in MSW. Carbon dioxide from the incineration of chemically unaltered biomass (e.g., wood, yard wastes, and food wastes) and even chemically altered biomass (e.g., pulp and paper products, leather, rubber, and some other polymers of plants) does not result in a net increase in the concentration of carbon dioxide in the atmosphere, unlike fossilized biomass. The recent biomass, as opposed to fossil biomass, is renewable, since growing plants fix sufficient carbon dioxide into new biomass to essentially recycle the atmospheric carbon dioxide produced by their eventual decay or combustion. As pointed out earlier, combustion of fossilized biomass (e.g., petroleum, coal, etc.) does cause a net increase in atmospheric carbon dioxide.
The use of renewable plant biomass, including such materials as waste pulp and paper products in MSW, for producing solid, liquid, and gaseous fuels, chemicals, fertilizers, and other useful products, in addition to energy via direct combustion, would reduce or eliminate dependence on fossil materials and the unwanted secondary effects of the use of fossil materials as noted above, and, at the same time, would reduce unused and discarded waste.
In order to be able to fully utilize plant biomass to replace fossilized carbonaceous materials, it is necessary to transform the plant biomass, particularly woody biomass, into a form that is easily accessible to various chemicals, enzymes and/or microbes to convert the biomass into the desired end products. Natural biodegradation is an excellent means to break down plant biomass to its basic substituents, but the process is too slow to meet the demand for raw materials in industrialized societies. Therefore, if plant biomass is to be effectively used, it must be rapidly degraded.
Woody biomass is a hard substance that provides few points of entry for chemicals, enzymes and microbes to gain access to the composite molecules. The pulp and paper industry has already devised ways to at least partially break down the structure of woody biomass through mechanical size reduction and chemical treatments, but since the desired end products of this industry must retain a fibrous consistency with tensile strength and rigidity, additional treatments are necessary to transform these pulp and paper products into a homogenous cellulosic feedstock suitable for the final molecular breakdown into other useful products, such as fuels, chemicals and fertilizers.
The fibrous materials of pulp and paper products have been obtained from wood. Wood, like other plant materials, is a product of a biological process known as photosynthesis, in which plants consume simple inorganic minerals, carbon dioxide and water using sunlight as an energy source, and metabolically manufacture all of the different types of organic molecules consistent with living organisms. Photosynthetic organisms, mostly green plants, are at the top of the food chain, and they also yield oxygen as a by-product of the photosynthetic process. Such plants are not only a source of food and fiber for all other living organisms, but they also consume a greenhouse gas, carbon dioxide, and emit oxygen, which is required by all living organisms, including photosynthetic plants for metabolic โcombustionโ of carbonaceous molecules called respiration.
Respiration is a metabolic process whereby organic molecules serve as food from which living organisms extract the solar energy entrapped in the chemical bonds of the molecules for life processes while consuming oxygen for the oxidation or combustion of the food and emitting carbon dioxide and water as by-products. The principal and most abundant type of organic material of plant biomass is the structural component called lignocellulose. This material is composed mostly of three distinct biopolymers: cellulose, hemicellulose and lignin. These biopolymers are an abundant source of renewable energy and carbonaceous material that can and will eventually replace fossilized materials for the production of fuels, chemicals, fertilizers, and energy.
Prior attempts have been made and a few processes have been developed to separate pulp and paper products from commingled mixtures of waste and to break down the pulp and paper products to its substituents for varied uses. Previous methods have relied on physical shearing of such materials to simply reduce the particle size. There are a variety of these so-called โdryโ methods that subject these materials either to high-speed hammer mills or low-speed grinders to produce a fairly uniform particle size (โfluffโ). This fluff is usually prepared from waste, such as MSW, and after separation of dense materials, such as glass, grit, ferrous metals, and high moisture contaminants that have also been reduced in particle size during the shredding process, the dry fluff is used as โrefuse derived fuelโ for direct combustion to produce energy.
Another so-called โwetโ method utilizes a device called a hydropulper, which is the equivalent of a large kitchen blender, to shred such materials suspended in a large volume of water. This is a popular method used by the pulp and paper industry to reduce the particle size of such materials so that it may be recycled into the manufacture of new pulp and paper products.
These methods do yield pulp and paper products of a fairly uniform size, but none of these methods is intended to, nor do they, alter the basic molecular structure of the cellulosic fibers of the pulp and paper materials to facilitate the intercalation of chemicals, enzymes, or microbes into the structure to bring about a more efficient and complete breakdown of the polymeric molecules comprising the fibrous materials.
A brief summary of the prior art attempts and other processes that involve processing of wastes and other materials follows.
U.S. Pat. No. 5,427,650 to Holloway discloses an apparatus and method for separation, recovery, and recycling municipal solid waste and the like by introducing solid waste materials into a rotatable pressure vessel, rotating, pressurizing, adding pH controlling chemicals and heating the pressure vessel and thus the waste material while simultaneously applying a mixing action to the solid waste material. Further, a vacuum is applied to the vessel to control the moisture content of the final fine organic portion of the process material.
U.S. Pat. No. 4,844,351 to Holloway discloses a method for treatment of mixed waste containing various plastics, such as municipal solid wastes, in which mechanical agitation and heat distortion of plastic films cause rupture and spilling of the contents of plastic film containers in the waste. The operating temperature of the process is in the range of about 195ยฐ F. to 215ยฐ F.
U.S. Pat. No. 4,540,495 to Holloway discloses a process for treating municipal solid waste material in the presence of moisture for the separation and recovery of inorganic matter and organic matter wherein the waste material is fed into a pressured chamber and is agitated therein. The contents of the pressure chamber are subjected to heat under a pressure for a predetermined period of time to cook, sterilize and soften the organic matter contained therein. The moisture content of the waste material is controlled so that the fines of the organic fractions have a residual moisture content ranging from about 60% to 70%.
U.S. Pat. No. 4,342,830 to Holloway discloses a process for recovery of organics and inorganics from waste material with a specific object of preparing the separated organic fraction for the production of ethanol wherein rigid organic matter becomes soft when subjected to heat and pressure. The process is carried out by feeding the waste material into a perforated container mounted within a closed chamber. The container is then agitated by suitable means, such as by rotation, as the chamber is subjected to pressure and heat to sterilize the waste material and soften the organic matter contained therein. The chamber is then depressurized wherein the softened organic matter is forced out of the container through its perforation, leaving only inorganic matter therein. The softened organic matter is shredded and broken up as it is forced through the perforations of the container.
U.S. Pat. No. 5,119,994 to Placzek discloses an apparatus and method for processing medical waste materials comprising an elongate pressure vessel having an inlet end, and a closely fitting inlet closure member. Moisture and heat are utilized to aid the processing of the waste.
U.S. Pat. No. 4,974,781 to Placzek discloses a method and apparatus to affect the separation of component fractions from paper-containing and plastic-containing waste materials. The method utilizes a rotating vessel equipped with lifting paddles and directional flighting. Moisture and heat are added in the process to effect repulping of paper materials.
U.S. Pat. No. 5,556,445 to Quinn et al. discloses a method for treating solid municipal waste material including placing solid municipal waste in a rotating chamber having an interior at ambient pressure, heating the waste at ambient pressure, and controlling the moisture content of the waste.
Russian Pat. No. 278406 discloses a process for treating wood chips within an agitating container at a temperature of 100ยฐ C. with saturated steam at 110 C. in the complete absence of air and at a relative humidity of 40%.
European Pat. No. 0 407 370 A2 to Richter discloses a method and apparatus providing for the continuous digestion of comminuted cellulosic fibrous material (e.g. wood chips) to produce paper pulp, with increased sulfidity.
U.S. Pat. No. 5,198,075 to Nivelleau de La Bruniere et al. discloses a method of digesting lignocellulose materials impregnated with solutions of hydroxides or salts of alkali or alkaline earth metals.
U.S. Pat. No. 4,632,729 to Laakso discloses a method and apparatus for effecting presteaming and deaeration of wood chips, or like, comminuted cellulosic fibrous material. The method utilizes a vertical presteaming vessel and a second vessel for deaeration.
U.S. Pat. No. 5,164,042 to Larsen et al. discloses a method of producing high-yield pulp from pulp chip material containing lignocellulose. The pulp chipped material is treated with steam in a steam treating station for driving air out of the material and heating the material. The heat treated material is then mixed in a mixing station with a liquid containing chemicals.
U.S. Pat. No. 5,470,433 to Brodersen et al. discloses a process for the delignification of cellulose fiber plant raw material for the production of pulp using separate impregnating and delignifying stages, each using alcohol and alkali.
U.S. Pat. No. 5,624,616 to Brooks discloses a method for making lignocellulose fibers, which may be optionally coated with a suitable thermoplastic, wherein the starting materials may be chosen from a wide variety of generally non-recyclable contaminated wood, paper, and/or plastic products. A mixture of the preferred lignocellulose material characterized by a relatively low moisture content and the desired thermoplastics is refined and comminuted in a steam atmosphere which is at a temperature, pressure, and duration sufficient to soften both the lignin within the wood chips and the thermoplastic polymer. The temperature of the steam atmosphere is relatively high, at least about 170ยฐ C., because of the use of dry wood chips which do not result in excessive vaporization during heating. The method also uses a steam pressure of at least 100 psig.
U.S. Pat. No. 5,176,793 to Kurtz discloses a method for treating wood-fiber pulp, particularly pulp which contains recycled paper. The pulp is dewatered and then heated by means of super heated steam under pressure prior to being passed to a disburser in which the pulp is finely divided. The pulp is then passed from the disburser to a plug-outfeed screw.
U.S. Pat. No. 4,999,084 to Lang et al. discloses a method for removing wax particles from short fiber fractions, which have been separated from long fibers.
U.S. Pat. No. 5,137,599 to Maxham discloses a process for the production of paper making fiber or a pulp from waste solids emanating from pulp and paper mills, particularly waste solids and processed water streams.
U.S. Pat. No. 5,391,261 to Van Den Bergh discloses a method of bleaching de-inked pulped and removing the ink polar particles with steam.
U.S. Pat. No. 5,262,003 to Chupka et al. discloses a process of preparing a suspension of paper making fibers in water for use in the making of paper.
U.S. Pat. No. 4,872,953 to Smith discloses an apparatus and method for improving the quality of paper manufactured from recycled paper stock with comprises a hydrokinetic amplifier, a pulper, a dump chest, a cyclone separator, a pressure screen, a vibratory screen and a holding tank.
U.S. Pat. No. 5,122,228 to Bouchette et al. discloses a method of treatment of waste paper or the like at high temperatures in the range of 160ยฐ C. to about 230ยฐ C. The furnish is treated in a digester with or without added chemicals but in the presence of saturated steam. The preferred dwell times are in the range of about 1 minute to about 6 minutes. The treated furnish is then discharged from the digester, preferably, but not exclusively by an explosive discharge.
U.S. Pat. No. 4,312,701 to Campbell discloses a method for defibrating waste paper and disbursing contained asphalt and wax contaminates within the fibers. The waste paper is initially pulped with water and the resulting stock is then contacted with a high pressure stream of steam having a velocity in the range of 1200 to 1600 ft/sec. The mixture of steam and stock is passed through a mixing tube under highly turbulent conditions to defibrate the waste paper and disburse any asphalt, waxes, and other contaminates throughout the separated fibers. The resulting stock can be used in paper making processes, particularly for the production of paper board products.
U.S. Pat. No. 3,057,769 to Sandberg discloses a process of making paper of uniformed appearance free from normally visible spots from waste paper stock carrying bituminous material. The process uses a paper beater for disintegrating the stock, and makes a slurry of 0.7 to 1% of fiber in water.
U.S. Pat. No. 4,297,322 to Liu discloses equipment and method for treating solid waste in which a non-oxidizing atmosphere is provided through which the shredded solid wastes falls freely, unsupported and non-contacted, to prevent fusion of the plastics with each other, with other materials in the solid waste, or with the walls or components in the treating equipment. The process operates at temperatures of about 600 to 900ยฐ F.
U.S. Pat. No. 4,325,707 to Burke, Jr. discloses a method and apparatus for treating solid municipal waste or other material within a pressure vessel which is pressurized with steam or a compressed gas. The pressure vessel is referred to as a โcannonโ because the pressure vessel has a hinged mussel closure which can be opened rapidly by the pressure inside the vessel so that the solid material passes through the opening created.
U.S. Pat. No. 3,741,863 to Brooks discloses a method of providing cellulosic fibers and fiber bundles from sources of waste material, such as municipal and industrial waste products, for making medium density fiber board and/or paper. The process is a dry process utilizing the cellulosic products present in municipal and household waste. The waste is pulverized into small pieces, where after it is dried to remove excess moisture, and also for sterilization. After separating the cellulosic material from the other constituents of the waste, the cellulosic material is heated in the presence of a non-flammable medium, such as steam, to raise the temperature thereof and to affect further sterilization.
U.S. Pat. No. 4,540,467 to Grube et al. discloses a method and apparatus for the removal of mold core material from metal castings and for fragmentation of municipal waste material, e.g., paper products, involving heating and hydrating the materials within a pressure vessel. Chemicals active on the material to be processed or the hydration water are added during hydration to soften the material to be removed or fragmented. Excess liquid in the vessel is drained and pressurized steam is added for a selected period of time. A suitable temperature and pressure are achieved such that the moisture or liquid carried by the processed material will rapidly turn to steam or vapor when the pressure in the vessel is rapidly reduced by quickly opening and unloading means at the bottom of the pressure vessel. The sudden release of pressure (explosive) in the vessel causes the moisture to change to steam and a certain portion of the liquid in the material to flash to vapor in accordance with thermodynamic laws. The resulting rapid expansion within the processed material fragments it.
U.S. Pat. No. 4,079,837 to Grube et al. discloses a method for the separation of components of solid wastes which has been treated by thermal explosive decompression followed by biodegradation (also referred to as composting). The explosive decompression and composting pretreatment before separation presents a granular and inoffensive finely-divided product mixed with less fragmented nonbiodegradable materials such as plastic, metals and other substances. The method first separates the finely-divided product from the waste to leave a first residue, then magnetically separates any magnetic components from the first residue to leave a second residue, and then separates by gravity floatation any plastic components from the second residue, each step being carried out successfully without any interruption for further treatment of the waste.
U.S. Pat. No. 4,461,648 to Foody discloses a method for increasing the accessibility of cellulose in lignocellulosic materials to chemical or biochemical reagents. The method has extremely high operating pressures, 250 to 1000 psig, and has a purging step while the materials are under pressure.
Accordingly, it has been one objective of this invention to provide improved processes for transforming diverse pulp and paper products into a homogeneous cellulosic feedstock.
Another objective of the invention has been to provide processes for the volume reduction of municipal solid waste (MSW). A further objective of the invention has been to provide processes for reducing the volume of MSW while producing components during that process for use as replacements for fossil material.
Still another objective of the invention has been to provide an improved process for transforming diverse pulp and paper products into a homogeneous cellulosic feedstock useful for conversion into fuels, chemicals, fertilizers, and other useful products.
SUMMARY OF THE INVENTION
The present invention is a method for treating diverse pulp and paper products, from waste paper and MSW, to produce a homogenous cellulosic feedstock that can be used as a direct combustion fuel, or converted into other solid, liquid, or gaseous fuels, chemicals, fertilizers and other useful products. More specifically, the homogenous cellulosic feedstock derived from the present invention is thus concerned not only with depletion rates of the finite source of fossil materials and reduction of the generation of excess carbon dioxide released from burning or consumption of such fossil materials, but also with the reduction in the volume of unused and discarded MSW. Various aspects of the present invention as will be appreciated, are realized in the improved processing of diverse pulp and paper products, for use as feedstocks for energy sources, and as feedstocks for chemical, enzymatic and microbial conversions into fuels, chemicals, fertilizers, and energy.
Diverse pulp and paper products in relation to the present invention means any and all known products produced by the pulp and paper industry through the mechanical and chemical treatment of woody biomass and plant fibers to convert such biomass materials into reformulated products. Examples of such pulp and paper products include, but are not limited to, Kraft paper, sulfite paper, bond paper, ledger paper, computer paper, printers mixed paper, special file stock, pressed board, box board, card board, corrugated card board, and packaging materials and components.
The most abundant and cheapest sources of pulp and paper products are waste paper and MSW, with MSW often containing 50% or more pulp and paper products. While this invention is primarily designed for using waste paper, it is also capable of utilizing MSW as a source of pulp and paper products for transformation into a homogeneous cellulosic feedstock for the chemical, enzymatic and microbial conversions into fuels, chemicals, fertilizers, and/or energy.
The present invention thus contemplates a method of transforming diverse pulp and paper products into a homogenous cellulosic material that is an ideal feedstock for chemical, biological and/or thermal conversion to yield a variety of fuels, chemicals, fertilizers, and/or energy.
Pulp and paper products are abundant, cheap, and renewable materials made from woody biomass that has already undergone extensive mechanical and chemical degradation of the lignocellulose, but the invention contemplates further transformation into feedstocks that are soft and loose with tremendous surface area for access by chemicals, enzymes, and microbes to be able to achieve a rapid and effective conversion to chemical substituents. The major chemical components of cellulose and hemicellulose, particularly the sugars glucose, mannose and xylose can be further converted into useful fuels and chemicals by biological fermentations. The other chemical components, mainly from lignin, can be converted into a variety of hydrocarbon products by chemical and thermochemical decomposition.
One transformation process, according to one embodiment of the present invention, includes the following steps:
(a) feeding diverse pulp and paper products into a vessel;
(b) introducing steam into the vessel while agitating the products;
(c) purging gases from the vessel while agitating the products;
(d) sealing the vessel so that the vessel is pressure tight;
(e) saturating the products with steam at sufficient temperature and pressure to expand molecular structure of the products;
(g) depressurizing the vessel to further enhance the molecular expansion of the products; and
(h) discharging the processed products therefrom.
The process of the present invention is environmentally conscious, in that it allows any volatile organic compounds (VOCs), air polluting compounds, and any other undesirable gases associated with the pulp and paper products or MSW to be purged from the vessel in a controlled manner, captured and collected. Furthermore, this process physically and chemically breaks down the pulp and paper products into the desired end product, namely a homogenous cellulosic feedstock that can be used as a direct combustion fuel and/or converted into other fuels, chemicals, fertilizers, and other useful products.
Accordingly, one object of the present invention is to improve the management and collection of VOCs, air pollutants and any other undesirable gases that would usually be emitted from MSW buried in landfills and particularly such substances that would be emitted during the transformation process.
An alternative transformation process according to the present invention, comprises the following steps:
(a) feeding diverse pulp and paper products into a vessel;
(b) sealing the vessel so that the vessel is pressure tight;
(c) injecting steam into the vessel while agitating the products;
(d) saturating the products with steam at a temperature in the range of about 287ยฐ F. to about 312ยฐ F. and at a pressure in the range of about 40 psig to about 65 psig to expand the molecular structure of the products;
(e) depressurizing the vessel to further enhance the molecular expansion of the products; and
(f) discharging the processed products therefrom.
Like the previous process, this process may further include the step of purging gases from the vessel for the same reasons as cited above.
In either process, it is desirable to capture any remaining VOCs or other pollutants during the depressurizing step. Such VOCs and other pollutants can then be treated prior to release to the atmosphere. In fact, the collection of VOCs and other pollutants from the vessel can be separated into condensables and noncondensables which would be likely treated differently. For example, condensers can be used to condense some of the purged gases prior to cooking the products, and condense the decompression steam, which may contain some VOCs and/or other pollutants that are volatilized at temperatures above 212ยฐ F. The capture of condensable and noncondensable components during the depressurizing step aids in cooling and drying the processed products.
If starting with MSW, preferably the discharging step includes the step of screening discharged products, then separating larger sized products and returning larger sized products to a second similar transformation process. It is also desirable to separate any remaining non-cellulosic components from the products by any suitable process such as by screening, air classification, etc.
In yet another alternative process, a plurality of vented vessels are interconnected, each capable of treating its pulp and paper products as noted above. The discharging steam upon opening one vented vessel is channeled to an adjacent vented vessel for purging that vessel and so on down the chain of vessels. The discharged material is conveyed from each vessel to a common separation of non-cellulosic components (when MSW is used) and with the separated larger sized cellulosic component recycled through the system a second time for further treatment.
Accordingly, the present invention provides a process of transforming diverse pulp and paper products into a homogenous cellulosic feedstock which provides a substitute direct combustion fuel that can reduce the dependency upon fossil fuel materials and correspondingly reduces carbon dioxide production from the combustion of fossil fuel materials; provides a means of reducing the quantity of unused and discarded wastes; and provides a means to capture volatile organic compounds and other environmentally damaging gases from wastes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a vented vessel used in accordance with the present invention;
FIG. 2 is a partial, cross-sectional view of FIG. 1 taken along line 2 โ 2 ;
FIG. 3 is a schematic view of the vented vessel oriented in a filling position;
FIG. 4 is a schematic view of the vented vessel oriented in a discharging position; and
FIG. 5 is a flow chart in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
The method for treating diverse pulp and paper products for producing a homogenous cellulosic feedstock can be used generally with any known suitable vessels. However, by way of example, the discussion regarding the method of the present invention will be related to the vented vessel as shown in FIG. 1 . As shown in FIG. 1, the vented vessel, generally designated 10 , includes a cylindrical housing 12 with a closed end 14 , except for a centrally disposed penetration port 16 , which is connected to a rotary union 18 for steam injection and/or depressurization. The opposite end 20 of the vessel 10 includes a doorway 22 for introduction of the waste materials to be processed in the vessel interior 24 , and for discharge of the processed materials. The doorway opening 22 may be the same diameter as the cylindrical housing 12 . Alternatively, the cylindrical housing 12 may be tapered to a smaller diameter 26 for large diameter vessels for economical and mechanical reasons related to the door closure and weight thereof. The door 28 is preferably completely detachable from the vessel 10 to allow free rotation of the vessel 10 about its horizontal axis in either a clockwise or a counter clockwise direction, either with the door 28 attached and closed as generally shown in FIG. 1 or with the door 28 open and detached (not shown). The door 28 includes a second penetration port 30 which is also connected to a rotary union (not shown, but similar to 18 ) for the addition of a vent valve (not shown). The vessel 10 includes an over-pressure relief valve (not shown).
As shown in FIG. 2, the vessel interior 24 is preferably equipped with two or more helical flights 32 that traverse the entire length of the vessel 10 , including the closed end 14 and the tapered end 20 , if present. The number of flights is determined on the basis of the vessel diameter, and the flights would be positioned equidistant from each other around the circumference of the vessel interior 24 , for example, two flights would be 180ยฐ apart, four flights would be arranged such that a single flight is 90ยฐ apart from an adjacent flight. The flights are attached to the interior walls of the cylindrical housing 12 , the closed end 14 , and the tapered end 26 (if present) and would radiate toward the horizontal axis. The optimum height of the flights from the wall toward the horizontal axis and the frequency of the spiral along the length is determined empirically. Depending on the length of the cylindrical housing 12 , at least two equally disposed sparging lines (not shown) may be attached to the interior wall of the cylindrical housing 12 or alternatively, attached to the exterior wall of the cylindrical housing 12 with penetrations into the interior of the cylindrical housing 12 through which steam may be injected into the interior of the housing 12 . The sparging lines could be parallel to the horizontal axis or alternatively combined with the helical flighting. Holes or other penetrations would exist in the sparging lines to provide high velocity steam injection when the pressure differential is great.
The vessel 10 is mounted in a frame, generally designated 33 , that allows rotation of the vessel in either a clockwise or counterclockwise direction about its horizontal axis H. The frame is capable of being pivoted to allow the door end 20 of the vessel 10 to be raised such that the vessel 10 may be tilted at a predetermined angle above horizontal for loading waste materials to be processed or lowered such that the vessel may be tilted to a predetermined angle below horizontal for discharging the processed materials, while simultaneously rotating the vessel in either rotational direction. The means of tilting the vessel 10 while allowing rotation is known in the art. The maximum and optimum tilt angles above and below horizontal would be determined empirically. Alternatively, the vessel 10 mounted in its frame may be positioned either horizontally or at a fixed angle of repose with respect to its horizontal axis, such that the closed end 14 is lower than the door end 20 . The optimum fixed angle would be determined empirically.
The vessel 10 further includes a means of support to allow rotation in either rotational direction to prevent flexing of the vessel 10 along its horizontal axis. The vessel 10 would also include means of support to allow the unit to be tilted above or below horizontal, or alternatively, to allow the unit to be mounted horizontally or at a fixed angle from horizontal as recited above while simultaneously allowing rotation in either direction. The vessel 10 further includes a means of rotation in either direction which shall be continuously variable in rotational speed from about 0 to about 10 rpm, with the optimum rotation speed during processing being about 5 rpm.
The door 28 of the vessel 10 should allow the vessel 10 to be rotated in either rotational direction either with the door 28 open or closed. Preferably, the door closure member 28 should be completely detachable from the vessel housing 12 .
The closed end 14 of the vessel 10 includes a centrally disposed penetration port 16 connected externally with a rotary union 18 that allows the vessel 10 to be rotated in either rotational direction while being connected to a stationary conduit for delivery of steam or for venting the vessel 10 . The stationary conduit may be of flexible high pressure construction to allow the vessel 10 to be tilted while connected to the stationary conduit. The penetration port 16 on the closed end 14 may be connected internally with the sparging lines to provide a means for steam to be injected via high velocity openings into the vessel interior 24 .
The doorway 22 is of the same diameter as the cylinder housing 12 or a smaller diameter for large diameter vessels in which the door end 20 of the cylinder housing 12 is conically tapered. A smaller doorway may be more economical and lighter in weight to facilitate removal of the closure member. The doorway 22 is centrally disposed and is not less than 3 feet in diameter. The closure member is preferably completely detachable from the vessel 10 to allow rotation in either direction with the closure member closed or removed. A penetration port is centrally disposed in the closure member for the connection of a vent valve generally designated 30 . A rotary union (not shown) may also be connected to the penetration port to allow the vessel 10 to rotate in either direction while connected to a stationary conduit for collection of vapors released via the vent valve 30 .
In operation, the vessel door 28 is opened or preferably removed, and the vessel 10 may remain in a horizontal repose or preferably may be either fixed or tilted to a predetermined angle above horizontal with the doorway opening 22 in the raised end position as best shown in FIG. 3. A suitable means, such as a belt conveyor, is inserted into the doorway 22 . The vessel 10 is rotated in the direction that the helical flighting 32 provides a means of conveyance of materials away from the doorway 22 and toward the closed end 14 of the vessel 10 .
A predetermined amount of water may be introduced into the vessel 10 , if deemed necessary, either prior to or concurrently with the introduction of the material to be processed. The amount of water added is dependent upon the moisture content of the material to be processed. A predetermined weight of the solid materials to be processed are then introduced into the vessel 10 while simultaneously rotating the vessel 10 in the above described direction. As the materials are introduced, a compaction and uniform wetting of the solid materials takes place. The moisture content of the solid materials should be at least 20% by weight, preferably in the range of 20%-60% by weight. Addition of solids is continued until the predetermined weight of material has been introduced into the vessel 10 . The volume of the vessel interior 24 filled or occupied by the waste will vary with the density of the material. The door closure member 28 is then replaced and sealed.
The vent 30 on the door 28 is opened and connected to an appropriate means to collect the vapors and condensate to be emitted. The vessel 10 may remain in a horizontal repose or preferably either the tilt angle of the vessel 10 is adjusted to or is fixed at a predetermined angle above horizontal for processing and the rotation of the vessel is reversed to convey materials up and away from the closed end 14 and toward the door end of the vessel 10 .
Steam is introduced via the penetration port 16 in the closed end 14 and into the vessel interior 24 via the high velocity openings in the sparging lines, if present. As the steam is introduced into the vessel interior 24 , the steam simultaneously transfers heat and moisture to the vessel 10 contents (waste) and saturated steam purges and/or displaces the air, vapors and other gases within the vessel 10 and its contents. This preheating and purging step is continued until the purged gases escaping the vent 30 on the door reach a temperature above 212ยฐ F., and the vent 30 is then closed. The vessel 10 is continuously rotated and steam injection is continued until the vessel 10 reaches a sufficient temperature and pressure to expand molecular structuring of the products. During the initial introduction of steam while the vent 30 is open and before significant internal steam pressure is reached, the saturated steam enters at a high velocity due to the pressure differential. This high velocity steam along with the vessel rotation exposes the contents to shearing forces and the steam also melts and tears any film plastic containers thus spilling their contents. The high velocity steam also forces both moisture and heat into the diverse pulp and paper materials and other biomass or water absorptive materials which also causes an expansion of the matrix of the pulp and paper materials making them more fragile for size reduction due to the mixing action taking place in the vessel.
The desired mixing action within the vessel is for the helical flighting to convey the materials near the vessel wall up and away from the closed end 14 of the vessel 10 but as the vessel 10 rotates, the material is also rolled and spilled over the edge of the flighting and falls due to gravity through an atmosphere of saturated steam, thus exposing the materials to mixing as well as both heat and moisture. The preferred angle of the helical flighting and the inclined angle of the vessel is determined empirically.
In the purging and heating process, absorbed moisture within the materials to be transformed and from condensate of the injected steam both displace entrapped gases and act as a heat transfer conduit. After the purge vent is closed and steam injection continues, the temperature of the water in the material increases above the boiling point of water (212ยฐ F. or 100ยฐ C.) and the water thus makes the transition from liquid to vapor, which is effective to permit the heated water to expand into a gas, which is about 22 times the volume of an equivalent weight of water, within the materials, opening up the materials and greatly expanding the molecular structure, thereby, producing a cellulosic feedstock material of great surface area, which is open to chemical, enzyme and microbe treatments, for producing fuels, chemicals, fertilizers, and other useful products, and additionally open to air for faster and more complete combustion. The biomass materials are not simply separated from any oversized product and non-biomass, but rather are transformed into a homogenous cellulosic feedstock more treatable than materials provided in other processes.
The vessel 10 and its contents are heated and pressurized to a maximum of about 65 psig or a minimum of about 45 psig of saturated steam, more preferably about 55 psig. Once the operating pressure is reached, the material is continuously mixed by rotating the vessel while simultaneously maintaining the pressure for at least 30 minutes up to a maximum of 1 hour. Preferably, the vessel 10 is rotated at a rotational speed in the range of about 0 to 10 rpm, more preferably 5 rpm.
Alternatively, with a properly insulated vessel, the steam injection may be continued until the maximum pressure of about 65 psig is reached, and then the steam injection may be discontinued but the mixing would be continued for the desired time period. This period of continuous mixing with or without continuous steam injection is to provide a period of time for the contents to reach equilibrium or uniformity of compositionโa state when the contents are uniformly mixed and transformed into the desired product with the combination of moisture and heat. After the desired equilibrium period, the vessel is depressurized via the vent 30 on the door while simultaneously and continuously mixing the contents to achieve as much heat and vapor loss as possible. As the steam atmosphere in the vessel is expelled, at least a portion of both the free moisture on the surfaces and the absorbed moisture in the contents within the vessel 10 are also vaporized which both cools and partially dries the materials. The vaporization of the absorbed moisture in the cellular and capillary areas of the cellulosic materials causes a rapid expansion of these structures due to the 22-fold increase in volume causing an expansion and exfoliation of the structures which further enhances the transformation of the materials into the homogenous cellulosic product.
After depressurization to atmospheric pressure, the processed materials remain hot and moist at about 212ยฐ F. Optionally, the vessel 10 would then be evacuated while continuously mixing to both further cool and dry the materials by using the latent heat and evaporating the moisture in the materials. Once the materials are cooled and dried to the extent desired the vessel 10 is returned to atmospheric pressure. The vessel 10 is briefly rotated in the initial or forward direction to convey the processed materials away from the door 28 . The door closure member 28 is opened or preferably detached from the vessel. The door end 20 of the vessel 10 preferably is lowered to tilt the vessel 10 to a predetermined angle below horizontal (FIG. 4 ), and the vessel 10 is rotated in the reverse direction to convey the processed materials toward the open doorway 22 . The contents are thus discharged from the vessel 10 . If there is no mechanism of lowering the vessel 10 below horizontal, or if the vessel 10 is mounted at a fixed angle of incline above horizontal, the contents will also be discharged from the vessel 10 by the helical flighting 32 when rotated in reverse direction but the unloading process usually takes considerably longer.
As generally represented schematically in FIG. 5 for example, the processed materials are preferably discharged onto a means of conveyance, such as a belt conveyor, for transport typically to a screening device, such as a vibratory or rotary trommel screener for separation based on size. The particle size of the cellulosic product may be determined empirically based on the desired end use of the cellulosic biomass. Very few cellulosic materials, other than woody biomass or lumber contaminants, are found in the process materials that are larger than 5 centimeters particle size. Typically, about 80% of the cellulosic biomass will be obtained in the less than 2.5 centimeters screen fraction. Preferably the screening process would take place with a heated air stream blowing over the materials to achieve further drying. This would be particularly effective in an enclosed rotary trammel with a hot air stream blowing through it. Any contaminating materials from a mixed waste stream larger than 5 centimeters would typically include ferrous metals, nonferrous metals, polyethylene terephthalate (PET) plastic containers, polypropylene (PP) plastic films and molded products, textiles, rubber, leather, and wood, and these materials may be sorted manually and/or mechanically for recycling. If an intermediate screen fraction of less than 5 centimeters, but greater than 1.3 centimeters is obtained, this fraction would include a small percentage of a mixture of the same materials as the greater than 5 centimeter fraction, but the 1.3-5 centimeter fraction would consist mostly of broken glass, amorphous aggregate of melted plastics, and incompletely transformed cellulosic materials, including pulp and paper materials. These materials may also be sorted into recycled products. If the desired cellulosic product is to be less than 1.3 centimeters, the 1.3-5 centimeter pulp and paper materials would be separated and recovered by various means such as an air knife, for reprocessing either by including in a subsequent batch of unprocessed materials or by combining with similar fractions from several batch processes to be reprocessed together as a batch.
The smallest particle size fraction from the screening step which would typically be less than 5 centimeters from a mixed waste stream would typically be contaminated with significant quantities of broken glass, ceramics, and amorphous aggregates of melted plastics and minor amounts of ferrous and nonferrous metals. Most of these contaminants may be removed by various means, such as a stoner or air classification using a hot air stream to dry and suspend the homogenous cellulosic product in the air stream. The heavy fraction from this step could also be sorted into recycled products or due to their small volume and composition discarded in an inert landfill. The smallest particle sized screened biomass fraction that has been further processed to remove the contamination of nonbiomass materials is the homogenous cellulosic product.
An alternative transformation process utilizes a similar vented vessel as shown in FIG. 1, but does not absolutely require the step of purging gases from the vessel and its contents prior to processing. However, such a step can be optionally used in the process. The steps of the alternative process are substantially identical to the process recited above, except that the alternative process occurs at a specific temperature and pressure range. Volatile organic compounds (VOCs) and other potential pollutants that would optionally be captured during an earlier purge step are in this alternative transformation process captured for treatment during the depressurization step to atmospheric pressure.
Preferably the residual moisture content of the processed cellulosic materials is significantly less than 65% by weight, and more preferably is less than 50% by weight. High moisture content has adverse effects on many possible processing steps subsequent to discharge from the vessel. As an example, moisture contents of the cellulosic product higher than 65% are more or less โself-adhesiveโ and tend to form into compact, dense spheres which are difficult to dry and air classify, rather than retaining loose, โfluffyโ texture, which is a preferred objective of this process. Additionally, the smaller particles tend to adhere to other cellulosic particles making the particle size larger than desired for screening and also the cellulosics to adhere to non-cellulosic contaminants making such materials less desirable for recycling. The principal purpose of moisture in the process is to insure uniform heat transfer and distribution throughout the biomass materials which facilitates the desired transformation. However, after the equilibration step, several steps may be included in the process to remove as much moisture as possible from the processed material, including depressurization with continuous agitation, evacuation, screening in a hot air stream, air classifying with hot air, etc. The evaporation of retained moisture after processing also enhances the transformation of the cellulosics into a fluff with extensive surface area while simultaneously cooling the products. Furthermore, a cool, dry product (less than 10% moisture by weight) may be stored for extended periods of time without odor or significant biodegradation as a result of molding or composting.
Having described the invention in detail and by reference to the drawings, it will be apparent that modifications and variations are possible without departing from the scope of the invention as defined in the following claims.
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A method for treating diverse pulp and paper products to produce a homogenous cellulosic feedstock comprises the steps of feeding diverse pulp and paper products into a vessel, introducing steam into the vessel while agitating the products, purging the gases from the vessel while agitating the products, sealing the vessel so that the vessel is pressure tight, saturating the products with steam at sufficient temperature and pressure to expand molecular structure of the products, while agitating the products, depressurizing the vessel to further enhance the molecular expansion of the products, and discharging the processed products. Alternatively, the method can be performed without purging the gases, if the temperature in the range of about 287ยฐ F. to about 312ยฐ F., and the pressure is in the range of about 40 to 65 psig. During the optional purging step, during the depressurization step, and during the optional evacuation step, volatile organic compounds and other air pollutants can be captured and treated.
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RELATED APPLICATION
The present application is a continuation of commonly assigned and U.S. patent application Ser. No. 09/629,124, entitled โMETHOD AND SYSTEM FOR MAINTAINING PERSISTANCE OF GRAPHICAL MARKUPS IN A COLLABORATIVE GRAPHICAL VIEWING SYSTEM,โ filed Jul. 31, 2000 now U.S. Pat. No. 6,738,076, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention pertains generally to collaboration environments, and more particularly to a method and system for maintaining persistence of graphical markups in a collaborative graphics environment that associates graphical markups to camera positions.
BACKGROUND OF THE INVENTION
Computer Aided Design (CAD) systems make it possible to create 3-dimensional models of parts and assemblies. At the same time, synchronous collaboration systems such as CoCreate, Inc.'s OneSpace, now allow remotely located users to communicate via a synchronously coupled view of one or more 3D objects. Collaboration environments are very useful in assisting communication between remotely located product designers, and between suppliers and manufacturers.
The use of graphical markup tools, which provide functionality for drawing shapes and adding text on the screen without modifying the 3-D model, enhances the communication ability of collaboration session members. As an example, suppose a first company manufactures automobiles that require a certain screw assembly which are supplied by a second company that specializes in manufacturing the screw assemblies. Engineers from the first and second companies can enter a collaborative graphical viewing environment to allow them to simultaneously view 3D models of the screw assembly. In the collaborative environment, because the views of each session member are coupled, one engineer can point a cursor at a point on the 3D screw assembly object shown on the screen, and the other engineers will see where that cursor is being pointed to. Collaborative markup tools allow better communication through a variety of shapes such as circle, arrows, and textual markups. For example, if it is desired to communicate to the screw assembly manufacturer to verify the length dimension of a pin in the screw assembly as displayed on the screen, a rectangle shape can be drawn around the pin on the screen and a text note attached requesting โCheck pin lengthโ. In the synchronous collaboration environment, the newly added markup will appear on the screens of every participating collaboration session member.
Often, it is desirable to save the results of a collaboration session to reload later. For example, it may happen that, due to the time constraints of participating members, a synchronous collaboration session must end before completion of the collaborative effort In this case, it would be desirable to be able to save the current state of the collaboration session and to be able to reload it later in order to continue the collaborative effort. As another example, all desired parties may not be available during the time the synchronous collaboration session is conducted. It would therefore be desirable in this case to save the results from the collaboration session, including named camera position views and graphical markups associated with those camera positions, for later viewing by members who were absent.
SUMMARY OF THE INVENTION
The present invention is a method and system for maintaining persistence of graphical markups created within a collaboration environment that allows users to save and reload camera position views and their associated markups. The graphical markup persistence capability of the invention is implemented in a collaborative graphical viewing system that associates graphical markups to named camera positions. In this type of collaborative graphical viewing system, the view seen on the screen is that seen by the camera; in other words, the rotation can be thought of as if the camera were moving rather than the object viewed by the camera. In this system, markups associated with a given camera position appear only when the view is rotated to the view corresponding to that camera position and disappear when the view is rotated to another camera position.
In accordance with the method of the invention, as the collaboration session member(s) begin to create graphical markups, a markup module associates the markups with the camera position at which the markups are made. The collaboration tool provides utilities to allow saving the graphical markups to the user's local disk, saving the graphical markups into a PDM system (either locally or remotely), and saving the entire collaboration session including graphical markups, notes, action items, etc. When saved to persistent storage, the camera position and all graphical markups associated with that camera position are stored in the markup file. The saved markups/session can later be reloaded from the user's local disk or the PDM system as appropriate. When a saved session is loaded into the collaboration session, all of the camera positions and associated graphical markups from the saved session are then accessible, allowing simple viewing of the results of the session, continuation-of-work, or asynchronous collaboration.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be better understood from a reading of the following detailed description taken in conjunction with the drawing in which like reference designators are used to designate like elements, and in which:
FIG. 1 is an illustrative embodiment of a graphical user interface displaying one 3-D model view associated with a named camera position in accordance with the invention;
FIG. 2 is the graphical user interface of FIG. 1 displaying a second view associated with a second named camera position in accordance with the invention;
FIG. 3 is a network diagram of one preferred embodiment of a collaborative graphical viewing system in accordance with the invention;
FIG. 4 is a network diagram illustrating the coupling of the graphical markups between the displays of the participating collaborative session members;
FIG. 5 is a high-level block diagram of a preferred embodiment graphical viewer application;
FIG. 6 is an illustrative embodiment of a markup file implemented in accordance with the invention; and
FIG. 7 is a class diagram of a set of classes used in one implementation of a markup module.
DETAILED DESCRIPTION
The present invention enables persistence of graphical markups associated with named camera positions created within a collaborative graphical environment.
FIG. 1 is an example graphical user interface 100 of a graphical viewing system in which the invention is implemented. Graphical user interface 100 comprises a viewing area 150 , a markup dialog 110 , and a named camera position list window 140 .
Viewing area 150 is the display area for displaying a 3D object 160 . In the illustrative example, the 3D object 160 is a screw assembly with, of particular interest in this example, a nut 161 and a pin 162 . In the graphical viewing system of the invention, the view seen on the screen is that seen by the camera; in other words, the rotation can be thought of as if the camera were moving rather than the object that the camera is looking at. Each view of the 3-D model is associated with a different camera position. Thus, every named camera position can have associated markup items that will show up when the view is rotated to the markup's associated camera position.
In FIG. 1 , the view of screw assembly 160 seen by the user in viewing area 150 is the front face of the screw. With the camera position arranged as such, the diameter of nut 161 may be easily measured.
Graphical user interface 100 includes a named camera position list window 140 . Named camera position list window 140 may be permanently displayed in the graphical user interface 100 , or alternatively may be implemented as a pop-up window, a drop-down menu, a tabbed pane, or any other well-known implementations for displaying a list on a screen. Named camera position list window 140 displays a list 142 of named camera positions 142 a , 142 b . As illustrated, the camera position associated with the front face displayed in viewing area 150 of FIG. 1 has been previously named FrontFace 142 a . Because the front face view associated with the camera position named FrontFace 142 a is currently displayed in the viewing area 150 , the name FrontFace 142 a in named camera position list window 140 is highlighted to indicate that it is the selected view. Other named camera positions, for example SideView 142 b , are also listed in the named camera position list window 140 .
In the illustrative embodiment, named camera position list window 140 includes a โGoToโ button 144 that allows the user to select a named camera position 142 a or 142 b from the list 142 and click on the GoTo button 144 to bring up the view seen by the named camera position in viewing area 150 .
The preferred embodiment graphical viewing application user interface provides two methods for associating markup items to camera positions. One method is to explicitly create a named camera position using the camera user interface in the named camera position list window 140 and then create markup items while that camera position is selected and displayed in the viewing area 150 . This is accomplished in the illustrative embodiment by changing the view to a desired view, clicking on the store button 145 in the camera user interface of named camera position list window 140 , and then editing the name in the store user interface to give it a desired name.
The second method is simply to allow the system to automatically create a named camera position by simply rotating the camera view to a position that displays the desired view, and then starting to create markup items. In the preferred embodiment, a new named camera position automatically pops up in the named camera position list window 140 . The automatically generated name can be modified later.
Markup dialog 110 is a window comprising a plurality of markup tools available to the user to create markups over the 3D view of the object associated with a camera position. In the illustrative embodiment, markup dialog 110 is implemented as a pop-up window; however, those skilled in the art will appreciate that the markup dialog 110 may alternatively be permanently displayed in the graphical user interface 100 , or implemented as a drop-down menu, a tabbed pane, or any other well-known implement for displaying a set of available functions on a screen. In the illustrative embodiment, the available functions are implemented as buttons and drop-down menus, as described herein.
As illustrated, markup dialog 110 includes functions for textual markup, 2-D shape markups such as circles 114 , rectangles 113 , polygons 118 , lines 116 , and arrows 115 , a free-hand pen tool 112 for drawing arbitrary shapes, leader text tool 117 that allows a user to highlight an area and attach a text comment with a pointer. Preferably, markup dialog 110 also includes shape preference options 119 such as line color, style and width, and fill specifications for the markup objects. Markup dialog 110 also preferably includes text preference options 120 such as font, font size, and text color.
The markup dialog 110 includes SAVE and LOAD buttons 122 and 121 that a user can click to save/load markup data to/from local disc. When saving using the SAVE button 122 , all the named camera positions and the associated markups are stored in the local markup file that user specifies. When loading by clicking on the LOAD button 121 , all the camera positions and the associated markups are loaded from the specified local file into the current session. When a user saves the markup data into a PDM system, the Markups created in that session are saved as a file in the PDM system. Similarly, when a user loads a markup file from a PDM system, the corresponding Markup data is loaded into the session.
The graphical user interface 100 includes a toolbar 125 that includes a session drop-down menu 126 with Save and Load menu items 127 and 128 . The collaboration tool allows a user to save the collaboration session data, including graphical markups if desired. In the illustrative embodiment, when the user clicks on Sessionโ>Save button 127 , he/she can specify if Markup data should be saved. If he/she checks that box, Markup data is saved to a file along with other session specific information (such as Notes, Modified Model files etc.) When a user saves a session into a PDM system, the Markups created in that session are saved as a file in the PDM system. Similarly, when a user loads a session from a PDM system, the corresponding Markup data is loaded into the session.
In the illustrative embodiment of FIG. 1 , a text leader markup item 130 / 131 has been dragged and dropped, and then sized, around nut 161 , with a comment โCheck nut diameterโ. The markup item 130 / 131 is associated only with this camera position (i.e., named camera position FrontFace 142 a ). In the collaborative environment, all collaboration members see the markup item. 130 / 131 whenever their viewing area displays camera position FrontFace 142 a.
FIG. 2 is a view of the example graphical user interface 100 where the camera position has been changed to display the side view of the screw assembly 160 . The camera position can be changed in one of two ways. The first method for changing the camera position is a dynamic rotation of the view. In the illustrative embodiment, dynamic camera position change is accomplished by clicking on the middle button of the mouse, which triggers the dynamic rotation function, and then dragging the mouse until the desired view of the model appears in the viewing area 150 . As soon as the current camera position starts to change, any markups associated with the current camera position disappear from the viewing area 150 . The second method for changing the camera position is to select a named camera position 142 a , 142 b from the camera position list 142 and then click on the GoTo button 144 . In this case, the view of the object model(s) and markups associated with this named camera position appear in the viewing area 150 , and any markups not associated with that view disappear from the viewing area 150 . In the example of FIG. 2 , when the SideView camera position 142 b is selected and loaded, the markups associated with the FrontFace camera position 142 a disappear and any markups already associated with the SideView camera position 142 b are displayed. In this example, a markup item 132 appears around pin 162 with the note 133 โCheck pin lengthโ.
FIG. 3 is a network diagram of one preferred embodiment of a collaborative graphical viewing system 10 in accordance with the invention. As illustrated, system 10 includes a server 20 executing a collaboration function 28 to allow two or more users to synchronously view a 3-D object and associate markups to one or more camera position views of the 3-D object. The collaboration function 28 synchronizes a plurality of graphical viewer applications 55 executing on respective clients 40 , 50 , and 60 . The collaboration function 28 may be executed on an initiator viewer's machine, or may reside and execute on a remote host 20 separate from any of the viewer applications. Collaboration function 28 allows clients 40 , 50 , 60 that are executing graphical viewer applications 55 to connect to the collaborative graphical viewer session using known collaboration connection techniques, for example, those used in OneSpace, manufactured by CoCreate, Inc. While the collaborative graphical viewer session is open, members of the session simultaneously view 3D objects and can create markup items associated with camera position views that are simultaneously viewed by all session members.
For centralized data management, network 12 may also be connected to a PDM server 22 , which manages and provides network-wide access to data stored in a PDM database 24 . Alternatively, or additionally, any one or more of clients (in this example, client 60 , as illustrated) may have a local storage disk 25 . In the preferred embodiment, a client 40 , 50 , 60 initiates a Save operation to save either only Markups or the entire Session (including Markups) in either a local file or a local or remote PDM system.
FIG. 4 is a network diagram illustrating the coupling of the graphical viewers between participating collaborative session members. As shown, the viewing area 150 of each session member is coupled to display identical camera position views and identical markup items. Each session member sees the same view of the 3D objects at the same camera position, along with the same markup items associated with the current camera position. In other words, the view displayed in the viewing area 150 of one session member is coupled to the viewing area 150 of all the other session members. The view and markup changes follow any view and/or markup changes triggered by any of the other session members. The same is true vice versa. View changes, e.g. a zooming in, moving the position or rotation of a product object, will show the same effect on the screens of all other session members. Additionally, a markup created by any session member will trigger the display of the same markup item with the same characteristics at the same position on all session members' displays.
FIG. 5 is a high-level block diagram of a preferred embodiment graphical viewer application 55 . As illustrated, graphical viewing application 55 includes a, user interface module 202 , a camera positioning module 204 , and a markup module 206 , among others. User interface module 202 implements the user interface functionality for all input from and output to the user, for example, displaying the graphical user interface 100 on the user's screen and receiving user input such as mouse clicks on the various buttons of the graphical user interface 100 .
Camera positioning module 204 implements the functionality for determining the camera view for any named camera position. It knows the association between the camera position name and actual view.
Markup module 206 includes a markup management function 210 that implements the underlying functionality for each of the markup buttons and options available in the markup dialog 110 of the graphical user interface 100 . Markup module 206 also includes a save function SaveMarkup 212 and a load function LoadMarkup 214 . Save function SaveMarkup 212 saves all the camera positions and the associated markups in a markup file 250 in persistent storage. This is preferably triggered by clicking on a Save button 122 in the Markup dialog 110 on the graphical user interface 100 .
Load function LoadMarkup 214 loads a markup file 250 associated with a previously saved session into the collaboration environment. Load function LoadMarkup 212 is invoked when the user clicks on a Load button 121 in the Markup dialog 110 on the graphical user interface 100 . When a user loads a markup file, all members of the session will view the contents.
When a Markup file is loaded, the camera position names in the file can be conflicting with those of the current session. If a camera position name is used in the current session as well as the file being loaded, one of the following configurations would be applied:
Overwrite the information in the current session; OR Ignore the file entry; OR Load operation fails and generates errors.
FIG. 6 is an illustrative embodiment of a markup file 250 implemented in accordance with the invention. As illustrated, markup file 250 includes a header 251 at the beginning of the file, followed by one or more camera position entries 252 a , 252 b , . . . , 252 n . Each camera position entry 252 a , 252 b , . . . , 252 n corresponds to one named camera position. In this embodiment, each camera position entry 252 a , 252 b , . . . , 252 n includes a camera position name 253 , camera position coordinates 254 to define the view of the objects loaded in that view, the number of markup items 255 , and one or more markup item fields 256 a , . . . , 256 n . Each markup item field includes a markup item type 257 and data 258 associated with that markup type.
One preferred embodiment implementation of the markup module 206 is implemented using JavaSharedDataToolkit for the collaboration functionality, Sun's Java2D Library to draw the shapes, and the following newly defined classes (shown in a class diagram in FIG. 7 ) to implement markup association: Markup Context 80 , Markup Plane 81 , MarkupWindow 82 , MarkupDialog 83 , MarkupItem 84 , MarkupEvents 85 , MarkupRectangle 86 , MarkupText 88 , MarkupTextEvents 89 , MarkupRectangleEvents 87 , MarkupCollaboration 90 a , 90 b , and SessionDialog 92 . A brief description of each class follows:
Markup Context 80 :
Only one MarkupContext 80 instance within a client is associated with one collaboration session. Maintains a list of all MarkupPlanes 81 that are associated with this Markup context. Maintains a list of all MarkupWindows 82 that are associated with this MarkupContext 80 . When a MarkupItem 84 changes (creation/deletion/modification) occur on a MarkupWindow 82 , the change is cascaded to all the other MarkupWindows 82 within this context that are showing the same MarkupPlane 81 . Handles Markup persistence (Save and Load).
MarkupPlane 81 :
Maintains a list of MarkupItems 84 . Provides methods to add/delete/get MarkupItems 84 from this list. Corresponds to a set of MarkupItems 84 that are drawn on a camera position view. A named camera position is a MarkupPlane 81 . The first time a markup item (e.g., 130 , 131 , 132 , 133 of FIGS. 1 and 2 ) is created by the user at a given camera position, an instance of a MarkupPlane 81 associated with that camera position is created along with an instance of a MarkupItem of the appropriate markup type, which is associated with that MarkupPlane 81 . A MarkupPlane 81 can be applied on zero or more MarkupWindow 82 instances at a time.
MarkupWindow 82 :
One instance corresponds to a window where markup items can be drawn/displayed. A MarkupWindow 82 can โshowโ one MarkupPlane 81 . Provides methods to switch to any MarkupPlane 81 . Communication between multiple clients is established at the MarkupWindow 82 level. E.g., if a rectangle is created, it sends a rectangle event message to all the clients who are โsharingโ that window. Handles the coordinates normalization and transformations. When a MarkupItem 84 needs to be drawn, it applies the appropriate transformations before drawing. When MarkupItem 84 manipulations (create, delete, modify markup item) occur, MarkupWindow 82 is informed so that it redraws the MarkupItem 84 and communicates this information to the remote MarkupWindows 82 that are sharing this window.
MarkupDialog 83 :
Responsible for showing the Markup palette and buttons for all the Markup operations. Listens to the events on the dialog (e.g., button click) Handles changing Markup preferences (e.g., Color) to the currently selected MarkupItem 84 .
MarkupItem 84 :
Base class for all the markup item types (e.g., Rectangle, Circle, Line, Text area). Includes a Draw( ) method that draws itself on the MarkupWindow 82 .
MarkupRectangle 86 :
One instance of this class corresponds to one rectangle markup item created on the MarkupPlane 81 . MarkupRectangle 86 is a derivation of a MarkupItem 84 .
Markup Text 88 :
One instance of this class corresponds to one textual markup item created on the MarkupPlane 81 . MarkupText 88 is a derivation of a MarkupItem 84 .
MarkupEvents 85 :
One Instance corresponds to one Markup event type (e.g., Rectangle Creation, Selection). Base class for all the Event handling classes for creating, selecting, modifying markup objects.
MarkupRectangleEvents 87 :
Listens to user interface events to create a MarkupRectangle 86 . MarkupRectangleEvents 87 is a derivation of a MarkupEvents 85 .
Markup TextEvents 89 :
Listens to user interface events to create MarkupText 88 . MarkupTextEvents 89 is a derivation of a MarkupEvents 85 .
MarkupCollaboration 90 ( 90 a , 90 b ):
Used by MarkupWindow 82 to communicate to remote MarkupWindows 82 . One instance per MarkupWindow 82 . When a new MarkupItem 84 is created on a window, it needs to send a message to all the remote clients that are sharing this window. MarkupCollaboration 90 a , 90 b implements the communication with the other clients that are sharing this window. When a message is received on a Markup channel, the corresponding method on the receiving MarkupWindow 82 is invoked. A Markup channel is a JavaSharedDataToolkit channel.
SessionDialog 92 :
Responsible for showing the collaboration session buttons for all the collaboration session operations (e.g., Connect, Save, Load). Listens to the events on the dialog (e.g., button click). When user clicks on the Save button, saves all the markup data to a file(along with modified model files, Action Items etc.). When user clicks on the Load button, a previously stored Session information is loaded into the current session. All the Markup data including the camera position data is loaded into the current session.
A class diagram illustrating the relationships of the classes is shown in FIG. 7 . As illustrated, MarkupContext 80 has a plurality of MarkupPlanes 81 , zero or one of which are displayed on a MarkupWindow-MarkupContext has a plurality of MarkupWindows 82 . In a MarkupContext 80 a MarkupDialog may optionally be displayed. Each MarkupPlane 81 has a one or more Markup items 84 , e.g. MarkupRectangle 86 and MarkupText 88 . MarkupRectangle 86 and MarkupText 88 are derivations of MarkupItem 84 . An instance of MarkupEvents listens to user interface events on a window and creates and modifies a MarkupRectangle class instance. Each MarkupWindow 82 is associated with a single MarkupCollaboration 90 a . MarkupCollaborations 90 a , 90 b communicate, typically on the Internet 70 using JavaSharedDataToolkit technology.
MarkupContext 80 corresponds to one Session Dialog 92 , which includes the methods SaveMarkup and LoadMarkup for respectively saving a collaboration session and loading a saved collaboration session.
Although the invention has been described in terms of the illustrative embodiments, it will be appreciated by those skilled in the art that various changes and modifications may be made to the illustrative embodiments without departing from the spirit or scope of the invention. It is intended that the scope of the invention not be limited in any way to the illustrative embodiment shown and described but that the invention be limited only by the claims appended hereto.
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A method and system for maintaining persistence of graphical markups created within a collaboration environment that associates graphical markups with the camera position is presented. The collaboration tool provides utilities to allow saving the graphical markups to the user's local disk, saving the graphical markups into a PDM system (either locally or remotely), and saving the entire collaboration session including graphical markups, notes, action items, etc., When saved to persistent storage, all the camera positions and all graphical markups associated with them are stored in the markup file. The saved markups/session can later be reloaded from the user's local disk or a PDM system as appropriate. When a session is loaded into the collaboration session, all of the camera positions and associated graphical markups from the saved session are then accessible, allowing simple viewing of the results of the session, continuation-of-work, or asynchronous collaboration. After a markup file is loaded the contents are accessible to all the members of the current collaboration session.
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CROSS-REFERENCE TO RELATED APPLICATION
This is the U.S. National Stage of International Application No. PCT/IB2003/000884 filed Mar. 11, 2003 and published in English on Sep. 23, 2004 under International Publication No. WO 2004/082288 A1.
FIELD OF THE INVENTION
The invention relates to a hybrid coding system. The invention relates more specifically to methods for supporting a switching from a first coding scheme to a second coding scheme at an encoding end and a decoding end of a hybrid coding system, the second coding scheme being a Modified Discrete Cosine Transform based coding scheme. The invention relates equally to a corresponding hybrid encoder, to a transform encoder for such a hybrid encoder, to a corresponding hybrid decoder, to a transform decoder for such a hybrid decoder, and to a corresponding hybrid coding system.
BACKGROUND OF THE INVENTION
Coding systems are known from the state of the art. They can be used for instance for coding audio or video signals for transmission or storage.
FIG. 1 shows the basic structure of an audio coding system, which is employed for transmission of audio signals. The audio coding system comprises an encoder 10 at a transmitting side and a decoder 11 at a receiving side. An audio signal that is to be transmitted is provided to the encoder 10 . The encoder is responsible for adapting the incoming audio data rate to a bitrate level at which the bandwidth conditions in the transmission channel are not violated. Ideally, the encoder 10 discards only irrelevant information from the audio signal in this encoding process. The encoded audio signal is then transmitted by the transmitting side of the audio coding system and received at the receiving side of the audio coding system. The decoder 11 at the receiving side reverses the encoding process to obtain a decoded audio signal with little or no audible degradation.
Alternatively, the audio coding system of FIG. 1 could be employed for archiving audio data. In that case, the encoded audio data provided by the encoder 10 is stored in some storage unit, and the decoder 11 decodes audio data retrieved from this storage unit. In this alternative, it is the target that the encoder achieves a bitrate which is as low as possible, in order to save storage space.
Depending on the available bitrate, different coding schemes can be applied to an audio or video signal, the term coding being employed for both, encoding and decoding.
Speech signals have traditionally been coded at low bitrates and sampling rates, since very powerful speech production models exist for speech waveforms, e.g. Linear Prediction (LP) coding models. A good example of a speech coder is an Adaptive Multi-Rate Wideband (AMR-WB) coder. Music signals, on the other hand, have traditionally been coded at relatively high bitrates and sampling rates due to different user expectations. For coding music signals, typically transformation techniques and principles of psychoacoustics are applied. Good examples of music coders are, for example, generic Moving Picture Expert Group (MPEG) Layer III (MP3) and Advanced Audio Coding (AAC) audio coders. Such coders usually employ a Modified Discrete Cosine Transform (MDCT) for transforming received excitation signals into the frequency domain.
In recent years, it has been an aim to develop coding systems which can handle both, speech and music, at competitive bitrates and qualities, e.g. with 20 to 48 kbps and 16 Hz to 24 kHz. It is well-known, however, that speech coders handle music segments quite poorly, whereas generic audio coders are not able to handle speech at low bitrates. Therefore, a combination of two different coding schemes might provide a solution for filling-in the gap between low bitrate speech coders and high bitrate, high quality generic audio coders. The combination of a speech coder and a transform coder is commonly known as hybrid audio coder. A mode switching decision indicating which coder should be used for the current frame is made on a frame-by-frame basis.
In a hybrid coder, it is one of the main challenges to achieve a smooth transition between two enabled coding schemes. Abrupt changes at the frame boundaries when switching from one coder to another should be minimized, since any discontinuity will result in audible degradation at the output signal.
A smooth transition is particularly difficult to achieve when switching from a first coder, e.g. a speech coder, to an MDCT based coder.
MDCT based encoders apply an MDCT to coding frames which overlap by 50% to obtain the spectral representation of the excitation signal. For illustration, FIG. 2 shows four MDCT windows over time samples of an input signal, each MDCT window being associated to another one of consecutive, overlapping coding frames. As can be seen, the overlapping portion of the windows of two consecutive coding frames n, n+1 corresponds to half of the length of a coding frame.
FIG. 3 illustrates how discontinuities are caused when switching from an AMR-WB speech coder to an MDCT coder. Each frame of a signal can be encoded either by an AMR-WB encoder or by an MDCT transform encoder. At the decoder, first an inverse MDCT (IMDCT) is applied to all frames which were encoded by the MDCT based transform encoder, and then the original signal is reconstructed by adding the first half of a current frame to the latter half of the preceding frame. In case a first frame n was encoded by the AMR-WB encoder and the following frame n+1 by the MDCT based transform encoder, discontinuities will be present at the decoder side at frame n+1, since the overlap component from the preceding frame n is missing.
The overlap component is important for the reconstruction, since it contains the original windowed signal and in addition the time aliased version of the windowed signal.
As described by Y. Wang, M. Vilermo, et. al. in โRestructured audio encoder for improved computational efficiencyโ, 108th AES Convention, Paris 2000, Preprint 5103, the MDCT works such that a signal sequence of 2N samples contains the following components: Between 0 and Nโ1 time samples of the original windowed signal plus the mirrored and inverted original windowed signal; between N and 2Nโ1 time samples of the original windowed signal plus the mirrored original windowed signal. The mirrored components are time aliases and will be canceled in the overlap-add operation.
In case the overlap component from the preceding frame is missing, the alias term cannot be canceled from the current frame n+1. This will result in audible degradation at the output signal.
In document โHigh-level description for the ITU-T wideband (7 kHz) ATCELP speech coding algorithm of Deutche Telekom, Aachen University of Technology (RWTH) and France Telekom (CNET)โ, ITU-T SQ16 delayed contribution D.130, February 1998, by Deutsche Telekom and France Telekom, it is, proposed to use a special transition window and an extrapolation when switching from a Code Excited Linear Prediction (CELP) coder to an Adaptive Transform Coder (ATC). The transition window enables the ATC to decode the last samples of a frame. The first samples are obtained by extrapolating the samples from the previous frames via an LP-filter. Such an extrapolation, however, might introduce discontinuities and artifacts especially in the case where the frame boundaries are at the onset of a transient signal segment.
SUMMARY OF THE INVENTION
It is an object of the invention to support a smooth transition between two coding schemes. It is in particular an object of the invention to support a smooth transition from a first coding scheme to a second coding scheme which constitutes an MDCT coding scheme.
For the encoding end of a hybrid coding system, a first method for supporting a switching from a first coding scheme to a second coding scheme is proposed. Both coding schemes code input signals on a frame-by-frame basis. The second coding scheme is a Modified Discrete Cosine Transform based coding scheme calculating at the encoding end a Modified Discrete Cosine Transform with a window of a first type for a respective coding frame, a window of the first type satisfying constraints of perfect reconstruction. The proposed first method comprises providing for each first coding frame, which is to be encoded based on the second coding scheme after a preceding coding frame has been encoded based on the first coding scheme, a sequence of windows. The window sequence splits the spectrum of a respective first coding frame into nearly uncorrelated spectral components when used as basis for forward Modified Discrete Cosine Transforms. Further, the second half of the last window of the sequence of windows is identical to the second half of a window of the first type. The proposed first method moreover comprises calculating for a respective first coding frame a forward Modified Discrete Cosine Transform with each window of the window sequence and providing the resulting samples as encoded samples of the respective first coding frame.
In addition, a hybrid encoder and a transform encoder component for a hybrid encoder are proposed, which comprise means for realizing the first proposed method.
For the decoding end of a hybrid coding system, a second method for supporting a switching from a first coding scheme to a second coding scheme is proposed. Both coding schemes code input signals on a frame-by-frame basis. The second coding scheme is a Modified Discrete Cosine Transform based coding scheme calculating at the decoding end an Inverse Modified Discrete Cosine Transform with a window of a first type for a respective coding frame and overlap-adding the resulting samples with samples resulting for a preceding coding frame to obtain a reconstructed signal. A window of the first type satisfies constraints of perfect reconstruction. The proposed second method comprises providing for each first coding frame, which is to be decoded based on the second coding scheme after a preceding coding frame has been decoded based on the first coding scheme, a sequence of windows. The window sequence would split the spectrum of a coding frame into nearly uncorrelated spectral components when used as basis for forward Modified Discrete Cosine Transforms, and the second half of the last window of the sequence of windows is identical to the second half of a window of the first type. The proposed second method moreover comprises calculating for a respective first coding frame an Inverse Modified Discrete Cosine Transform with each window of the window sequence and providing the first half of the resulting samples as reconstructed frame samples without overlap adding.
In addition, a hybrid decoder and a transform decoder component for a hybrid decoder are proposed, which comprise means for realizing the second proposed method.
Finally, a hybrid coding system is proposed, which comprises as well the proposed hybrid encoder as the proposed hybrid decoder.
The invention proceeds from the consideration that forward MDCTs using a window sequence instead of a single window for a respective transition coding frame can be employed at an encoding end for splitting the source spectrum into nearly uncorrelated spectral components. The same window sequence can then be used for inverse MDCTs at a decoding end. As a result, no overlap component from a preceding coding frame which is coded by some other coding scheme will be needed for a reconstruction of the transition frame. At the same time, the window sequence can satisfy the constraints of perfect reconstruction, if the second half of the window sequence is identical to the second half of the single windows employed for all other coding frames.
It is an advantage of the invention that it allows a smooth transition from a first coding scheme to an MDCT based coding scheme.
It is further an advantage of the invention that it does not require extrapolations during codec switching.
It is further an advantage of the invention that since a special MDCT window sequence takes care of the switching, also the overall operation of the coding system can be simplified.
Preferred embodiments of the invention become apparent from the dependent claims.
In an advantageous embodiment of the invention as well for the encoding end as for the decoding end, the shape of the windows of the first type is determined by a function, in which one parameter is the number of samples per coding frame. In the first half of a respective first coding frame at least one subframe is defined, to which a respective window of a second type is assigned by the window sequence, the shape of a window of the second type being determined by the same function as the shape of a window of the first type, in which function the parameter representing the number of samples per coding frame is substituted by a parameter representing the number of samples per subframe. It is understood that also a different offset is selected, since the window of the second type has to start off at a different position in the coding frame. In case more than one subframe is defined, the at least one subframe constitutes preferably a sequence of subframes overlapping by 50%. A window associated to the at least one subframe is overlapped respectively by one half by a preceding window and a subsequent window of the sequence of windows, the preceding window and the subsequent window having at least for the samples in the at least one subframe a shape corresponding to the shape of the window of the second type. The sum of the values of the windows of the window sequence is equal to โoneโ for each sample of the coding frame which lies within the first half of the coding frame and outside of the at least one subframe. Finally, the values of the windows of the window sequence are equal to โzeroโ for each sample which lies outside of the first coding frame.
While the second coding scheme has to be an MDCT coding scheme, the first coding scheme can be an AMR-WB coding scheme or any other coding scheme. The domain of the signal which is provided to the MDCT based coder can be the LP domain, the time domain or some other signal domain.
Further, the window of the first type can be a sine based window, but equally of any other window, as long as it satisfies the constraints of perfect reconstruction.
The invention can be employed for audio coding, e.g. for speech coding by the first coding scheme and music coding by the MDCT coding scheme. Moreover, it can be used in video coding to switch between different coding schemes. In video coding, the invention should be applied in a two-dimensional manner, in which first the rows are coded and then the columns, or vice versa.
The invention can be employed in particular for storage purposes and/or for transmissions, e.g. to and from mobile terminals.
The invention can further be implemented either in software or using a dedicated hardware solution. Since the invention is part of a hybrid coding system, it is preferably implemented in the same way as the overall hybrid coding system.
BRIEF DESCRIPTION OF THE FIGURES
Other objects and features of the present invention will become apparent from the following detailed description of an exemplary embodiment of the invention considered in conjunction with the accompanying drawings.
FIG. 1 is a block diagram presenting the general structure of a coding system;
FIG. 2 illustrates the functioning of an MDCT coder;
FIG. 3 illustrates a problem resulting in a hybrid coding system employing an MDCT coding scheme;
FIG. 4 is a high level block diagram of a hybrid coding system in which an embodiment of the invention can be implemented;
FIG. 5 illustrates a window sequence employed in the embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 to 3 have already been described above.
FIG. 4 presents the general structure of a hybrid audio coding system, in which the invention can be implemented. The hybrid audio coding system can be employed for transmitting speech signals with a low bitrate and music signals with a high bitrate.
The hybrid audio coding system of FIG. 4 comprises to this end a hybrid encoder 40 and a hybrid decoder 41 . The hybrid encoder 40 encodes audio signals and transmits them to the hybrid decoder 41 , while the hybrid decoder 41 receives the encoded signals, decodes them and makes them available again as audio signals. Alternatively, the encoded audio signals could also be provided by the hybrid encoder 40 for storage in a storing unit, from which they could then be retrieved again by the hybrid decoder 41 .
The hybrid encoder 40 comprises an LP analysis portion 401 , which is connected to an AMR-WB encoder 402 , to a transform encoder 403 and to a mode switch 404 . The mode switch 404 is also connected to the AMR-WB encoder 402 and the transform encoder 403 . The AMR-WB encoder 402 , the transform encoder 403 and the mode switch 404 are further connected to an AMR-WB+ (Adaptive Multi-Rate Wideband extension for high audio quality) bitstream multiplexer (MUX) 405 .
The hybrid encoder 40 comprises an LP (linear prediction) analysis portion 401 , which is connected to an AMR-WB encoder 402 , to a transform encoder 403 and to a mode switch 404 . The mode switch 404 is also connected to the AMR-WB encoder 402 and the transform encoder 403 . The AMR-WB encoder 402 , the transform encoder 403 and the mode switch 404 are further connected to an AMR-WB+ (Adaptive Multi-Rate Wideband extension for high audio quality) bitstream multiplexer (MUX) 405 .
When an audio signal is to be transmitted, it is first input to the LP analysis portion 401 of the hybrid encoder 40 . The LP analysis portion 401 performs an LP analysis on the input signal and quantizes the resulting LP parameters. The LP analysis is described in detail in the technical specification 3 GPP TS 26.190, โAMR Wideband speech codec; Transcoding functionsโ, Release 5, version 5.1.0 (2001-12), as first step of an AMR-WB encoding process. The quantized LP parameters are used for obtaining an excitation signal which is forwarded to the AMR-WB encoder component 402 and to the transform encoder component 403 . The quantized LP parameters are provided in addition to the mode switch 404 .
Based on the received LP parameters, the mode switch 404 determines in a known manner on a frame-by-frame basis which encoder component 402 , 403 should be used for encoding the current frame. The mode switch 404 informs the encoder components 402 , 403 on the respective selection and provides in addition a corresponding indication in the form of a bitstream to the AMR-WB+ bitstream multiplexer (MUX) 405 .
The AMR-WB encoder component 402 is selected by the mode switch 404 for encoding excitation signals resulting apparently from speech signals. Whenever the AMR-WB encoder component 402 receives from the mode switch 404 an indication that it has been selected for encoding the current signal frame, the AMR-WB encoder component 402 applies an AMR-WB encoding process to received excitation signals. Such an AMR-WB encoding process is described in detail in the above mentioned specification 3 GPP TS 26.190. Only an LP analysis, which forms in specification 3 GPP TS 26.190 part of the AMR-WB encoding process, has already been carried out separately in the LP analysis portion 401 . The AMR-WB encoder component 402 provides the resulting bitstream to the AMR-WB+ bitstream MUX 405 .
The transform encoder component 403 is selected by the mode switch 404 for encoding excitation signals resulting apparently from other audio signals than speech signals, in particular music signals. Whenever the transform encoder component 403 receives from the mode switch 404 an indication that it has been selected for encoding the current signal frame, the transform encoder component 403 employs a known MDCT with 50% window overlapping, as shown in FIG. 2 , to obtain a spectral representation of the excitation signal. The known MDCT is modified, however, for the transitions from the AMR-WB coding scheme to the MDCT coding scheme, as will be described in more detail further below. The obtained spectral components are quantized, and the resulting bitstream is equally provided to the AMR-WB+ bitstream MUX 405 .
The AMR-WB+ bitstream MUX 405 multiplexes the received bitstreams to a single bitstream and provides them for transmission.
At the decoder side of the hybrid audio coding system, reverse operations are performed.
The AMR-WB+ bitstream DEMUX 415 of the hybrid decoder 41 receives a bitstream transmitted by the hybrid encoder 40 and demultiplexes this bitstream into a first bitstream, which is provided to the AMR-WB decoder component 412 , a second bitstream, which is provided to the transform decoder component 413 , and a third bitstream, which is provided to the mode switch 414 .
Based on the indication in the received bitstream, the mode switch 411 selects on a frame-by-frame basis the decoder component 412 , 413 which is to carry out the decoding of a particular frame and informs the respective decoder component 412 , 413 by a corresponding signal.
The AMR-WB decoding process which is performed by the AMR-WB decoder component 412 when selected is described in detail in the above mentioned specification 3 GPP TS 26.190. An LP synthesis, which is described in specification 3 GPP TS 26.190 as part of the AMR-WB decoding process, follows separately in the LP synthesis portion 411 , to which the AMR-WB decoder component 412 provides the LP parameters resulting in the decoding.
The transform decoder component 413 applies a known IMDCT when selected. The known IMDCT is modified, however, for the transitions from the AMR-WB coding scheme to the MDCT decoding scheme, as will be described in more detail further below. The transform decoder component 413 provides the LP parameters resulting in the decoding equally to the LP synthesis portion 411 .
The LP synthesis portion 411 , finally, performs an LP synthesis as described in detail in the above mentioned specification 3GPP TS 26.190 as the last processing step of an AMR-WB decoding process. The resulting restored audio signal is then provided for further use.
This AMR-WB extended coder framework is also referred to as AMR-WB+.
A known MDCT based encoding and a known IMDCT based decoding are described in detail for example by J. P. Princen and A. B. Bradley in โAnalysis/synthesis filter bank design based on time domain aliasing cancellationโ, IEEE Trans. Acoustics, Speech, and Signal Processing, 1986, Vol. ASSP-34, No. 5, October 1986, pp. 1153-1161, and by S. Shlien in โThe modulated lapped transform, its time-varying forms, and its applications to audio coding standardsโ, IEEE Trans. Speech, and Audio Processing, Vol. 5, No. 4, July 1997, pp. 359-366.
The analytical expression for the regular forward MDCT of a k th coding frame is given by the equation:
X k โก ( m ) = 1 N ยท โ i = 0 N - 1 โข f โก ( i ) ยท x k โก ( i ) ยท cos โก ( ฯ N โข ( 2 โข i + 1 + N 2 ) โข ( 2 โข m + 1 ) ) ,
โข m = 0 , โฆ โข , N / 2 - 1 , ( 1 )
where N is the length of the signal segment, i.e. the number of samples per frame, where f(i) defines the analysis window and where x k (i) are the samples of the excitation signal provided by the LP analysis portion 401 to the transform encoder component 403 .
The analytical expression for the regular inverse MDCT for the k th coding frame is given by the equation:
q k โก ( m ) = โ i = 0 N / 2 - 1 โข h โก ( m ) ยท X k โก ( i ) ยท cos โก ( ฯ N โข ( 2 โข m + 1 + N 2 ) โข ( 2 โข i + 1 ) ) ,
โข m = 0 , โฆ โข , N - 1 , ( 2 )
where N is again the length of the signal segment and where h(m) defines the synthesis window.
The reconstructed k th frame can be retrieved by an overlap-add according to the equation:
x ~ k โก ( m ) = q k - 1 โก ( m + N 2 ) + q k โก ( m ) , m = 0 , โฆ โข , N / 2 - 1 , ( 3 )
where {tilde over (x)} k (m) constitute the samples which are provided by the transform decoder component 413 to the LP synthesis portion 411 .
The analysis and synthesis windows f(n) and h(n) satisfy the following constraints of perfect reconstruction:
f ( n )= h ( n ), n= 0 , . . . , N/ 2โ1
h ( Nโ 1 โn )= h ( n )
h 2 ( n )+ h 2 ( n+N/ 2)=1โโ(4)
Perfect reconstruction ensures that any aliasing error introduced at the decimation stage is canceled during the reconstruction. In practice, perfect reconstruction cannot be maintained since the spectral values are quantized. Therefore, the filters should be designed in a way that the aliasing error is minimized. This goal can be achieved with filters having a sharp transition band and high stop-band attenuation.
A window which is frequently employed for the MDCT and the IMDCT is the sine window, since it satisfies the constraints of equation (3) and minimizes the aliasing error:
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N
-
1.
(
5
)
The transform encoder component 403 and the transform decoder component 413 of the hybrid audio coding system of FIG. 4 employ the above equations (1), (2), (3) and (5) for all frames but those following immediately after a frame that was coded by AMR-WB.
For these transition frames, a special window sequence is defined, which satisfies the constraints for the analysis and synthesis windows and which achieves at the same time a smooth transition between AMR-WB and the MDCT based transform codec.
The definition of this window sequence will now be presented with reference to FIG. 5 . FIG. 5 is a diagram depicting an exemplary window sequence over samples in the time domain, a sample numbered โ0โ representing the first sample of the current coding frame. It is to be noted that the representation of the samples is not linear.
The length of the frame in samples present in the MDCT domain is denoted as frameLen. The length of the frame in the time domain is 2*frameLen, i.e. N=2*frameLen. In the example of FIG. 5 , there are 256 samples per frame in the MDCT domain, i.e. frameLen=256, and thus 512 samples per coding frame in the time domain. Two consecutive coding frames are overlapping by 256 samples in the time domain.
First, a subframe length is determined, which subframe length is denoted as frameLenS. The subframe length has to satisfy the following conditions:
{
frameLenS
<
frameLen
frameLen
โข
โข
mod
โข
โข
frameLenS
=
0
frameLenS
โข
โข
mod
โข
โข
2
=
0
(
6
)
That is, the value frameLen is to be an entire multiple of the value frameLenS, and the value frameLenS is to constitute an even number. For the example of FIG. 5 , frameLenS is defined to be equal to 64, which satisfies the above conditions (6).
Next, a first offset zeroOffset, a number of short windows numShortWins and a second offset winOffset are defined as helper parameters and calculated according to the following equations:
zeroOffset=(frameLenโframeLenS)/2โโ(7)
numShortWins=โzeroOffset/frameLenSโ
if(zeroOffset mod 2โ 0)
numShortWins=numShortWins+1โโ(8)
winOffset=zeroOffset+frameLenSโโ(9)
where the expression โxโ in equation (8) indicates the largest integer smaller than x. The number of short windows numShortWins has to be even according to equation (8).
For the example of FIG. 5 , zeroOffset is calculated to be 96, numShortWins is calculated to be 2 and winOffset is calculated to be 160.
The defined parameter values are all stored fixedly in the transform encoder component 403 .
Based on the stored parameter values, the transform encoder component 403 calculates numShortWins forward MDCTs of a length of frameLenS and one forward MDCT of a length of frameLen for the current transition coding frame. Each MDCT is calculated according to above equation (1), in which the window f(n)=h(n) is substituted by new windows h 0 (n), h 1 (n) and h 2 (n), respectively.
The first MDCT window h 0 (n) has a shape according to the following equation:
h
0
โก
(
n
)
=
{
0
0
โค
n
<
frameLenS
/
2
1
frameLenS
/
2
โค
n
<
frameLenS
sin
โก
(
ฯ
2
ยท
frameLenS
ยท
(
n
+
0.5
)
)
frameLenS
โค
n
<
2
ยท
frameLenS
(
10
)
In the example of FIG. 5 , the first window h 0 (n) is equal to zero for samples โ32 to โ1, i.e. for all samples preceding the samples of the current coding frame. For the following samples 0 to 31, the first window h 0 (n) is equal to one. For the samples 32 to 95, it has a sine shape. Thus, the first window h 0 (n) is positioned within the coding frame so that it starts from time instant โ32, while time instant 0 is the start of the coding frame. In equation (10), the first time sample from the coding frame is therefore multiplied with h 0 (32), the second sample with h 0 (33) etc. Since the values of h 0 (0) to h 0 (31) are all equal to zero, the time samples that correspond to time instants โ31 to โ1 are not needed. Whatever value they may have, the results of the multiplication would always be equal to zero.
The next numShortWinsโ1 MDCTs are calculated by the transform encoder component 403 based on the following window shape:
h
1
โก
(
n
)
=
sin
โก
(
ฯ
2
ยท
frameLenS
ยท
(
n
+
0.5
)
)
โข
โข
with
โข
โข
0
โค
n
<
2
ยท
frameLenS
(
11
)
This equation thus corresponds to equation (5), in which N was substituted by 2*frameLenS. In the example of FIG. 5 , there is a single window following equation (11), and this window h 1 (n) is positioned within the coding frame so that it starts from time instant 32 and ends with time instant 159.
Finally, the transform encoder component 403 calculates the MDCT of the length frameLen using the following window shape:
h
2
โก
(
n
)
=
{
0
0
โค
n
<
zeroOffset
sin
โก
(
ฯ
ยท
(
n
-
zeroOffset
+
0.5
)
2
ยท
frameLenS
)
zeroOffset
โค
n
<
winOffset
1
winOffset
โค
n
<
frameLen
sin
โก
(
ฯ
ยท
(
n
+
0.5
)
2
ยท
frameLen
)
frameLen
โค
n
<
2
ยท
frameLen
(
12
)
In the example of FIG. 5 , the last window h 2 (n) is equal to zero for samples 0 to 95, it has a modified sine shape like the first half of window h 1 (n) for samples 96 to 159, and it is equal to one for samples 160 to 259. The last part of the window from samples 259 to 511 is equal to the window employed for all other frames than the transition frames. Thus, this window h 2 (n) is positioned to cover exactly the entire coding frame.
The last window h(n) indicated in FIG. 5 belongs already to the subsequent coding frame, which is overlapping by 256 samples with the current transition coding frame.
On the whole, the described determination of the window sequence allows a variable length windowing scheme, which depends on the frame length frameLen and on the selected length of the subframesframeLenS.
The application of the described window sequence to a received coding frame results in frameLen+numShortWins*frameLenS spectral samples, i.e. in the example of FIG. 5 in 384 spectral samples. The spectral samples are then quantized by the transform encoder component 403 and provided as a bitstream to the AMR-WB+ bitstream MUX 405 of the encoder 40 .
At the receiver side the same window sequence is applied by the transform decoder component 413 of the hybrid decoder 41 for calculating separate IMDCTs according to the above equation (2) to obtain the reconstructed output signal for that frame. No knowledge is required about an overlap component from the previous frame.
The above presented special window sequence is valid only for the duration of a current frame, in case the previous frame was coded with the AMR-WB coder 402 , 412 and in case the current frame is coded with the transform coder 403 , 413 . The special window sequence is not applied for the following frame anymore, regardless of whether the next frame is coded by the AMR-WB coder 402 , 412 or the transform coder 403 , 413 . If the next frame is coded by the transform coder 403 , 413 , the conventional window sequence is used.
It is to be noted that the described embodiment constitutes only one of a variety of possible embodiments of the invention.
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Methods and units are shown for supporting a switching from a first coding scheme to a Modified Discrete Cosine Transform (MDCT) based coding scheme calculating a forward or inverse MDCT with a window (h(n)) of a first type for a respective coding frame, which satisfies constraints of perfect reconstruction. To avoid discontinuities during the switching, it is proposed that for a transient frame immediately after a switching, a sequence of windows (h 0 (n),h 1 (n),h 2 (n)) is provided for the forward and the inverse MDCTs. The windows of the window sequence are shorter than windows of the first type. The window sequence splits the spectrum of a respective first coding frame into nearly uncorrelated spectral components when used as basis for forward MDCTs, and the second half of the last window (h 2 (n)) of the sequence of windows is identical to the second half of a window of the first type.
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[0001] This application claims the benefit of Provisional Patent Application No. 60/344,053 filed on Jan. 3, 2002, and Provisional Patent Application No. 60/353,051 filed on Jan. 29, 2002 under 35 U.S.C. ยง119(e). The contents of the above-referenced applications are incorporated herein in their entireties.
[0002] Throughout this application, various references are referred to. Disclosures of these publications in their entireties are hereby incorporated by reference into this application to more fully describe the state of the art to which this invention pertains.
BACKGROUND INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to food compositions for the treatment of joint related ailments, and methods for making and administering these compositions. In particular, the present invention relates to the preparation of compositions including proteoglycan precursors and method for administering these precursors in a beneficial and appetizing manner to persons in need thereof.
[0005] 2. Description of the Related Art
[0006] Millions of people suffer from the debilitating effects of joint related ailments. Of particular interest in this area are the ailments related to arthritis. Among the many types of arthritis, osteoarthritis is the most prevalent, especially among the elderly. Osteoarthritis is associated with a breakdown of cartilage that commonly occurs in the joints such as, hips, knees, fingers, feet and spine. Over time, the cartilage may wear away in some areas greatly decreasing its effectiveness, even to the point where bones may rub directly against each other. Conventional treatments for osteoarthritis include medication, exercise, diet and applying heat and cold to the pain afflicted areas. None of these common treatments alter the progression of osteoarthritis. Among medications prescribed to address this illness, non-steroidal anti-inflammatories (NSAIDs) are the most common. Unfortunately, these medications have a number of side effects and may even increase the progression of osteoarthritis. Other forms of joint related ailments exist due to the everyday stress placed on these connective tissues.
[0007] Over the past two decades, an alternative treatment for joint related ailments has emerged. The alternative treatment involves administering glucosamine and chondroitin supplements to patients suffering from joint related ailments. These two proteoglycan precursors represent a proactive treatment for treating and maintaining joint health. Recently they have demonstrated pain relief effects in arthritic patients and may even reverse the effects of arthritis and assist the body to repair and rehabilitate damaged cartilage. Unlike other medications, they have no known side effects.
[0008] Glucosamine and chondroitin are components of normal cartilage. Both act as precursors in the formation of proteoglycans which in turn become the building blocks of connective tissue. While glucosamine is a multifunctional precursor of proteoglycan synthesis in general and glycosaminoglycans in particular, chondroitin is a glycosaminoglycan that is preferentially incorporated into cartilaginous tissue. Because of its tropism for cartilage, chondroitin is the most abundant glycosaminoglycan in cartilage and is responsible for the resiliency of joint tissue.
[0009] While the body normally generates enough proteoglycan precursors to maintain levels of cartilage throughout, many people suffering from arthritis require supplements of these very important compounds. However, it is difficult to supplement their intake merely by a change in diet because the sources of glucosamine and chondroitin are not commonly found in foods. In particular, glucosamine is derived and isolated from chitin. Chitin is a major component of the shells of sea animals such as crab and sea shrimp. Edible chondroitin on the other hand is derived from animal connective tissue such as tendons, cartilage and trachea. Because of the difficulty of including these items in a normal diet, glucosamine and chondroitin commonly require administration through oral supplements. Common oral supplements take the form of capsules, tablets or pills. Similar supplements are disclosed in U.S. Pat. No. 6,255,295, U.S. Pat. No. 6,162,787, and U.S. Pat. No. 5,840,715, among others. These types of delivery methods often fail because many people have difficulty taking pills, dislike taking them or forget to take enough to meet the effective dosage. Of particular interest is the elderly community, which commonly suffers from difficulties ingesting foods and nutrients. Many of their medications must be administered via liquid diets and/or intravenously. The following invention seeks to solve these problems by incorporating proteoglycan precursor supplements into a desirable food product that may be easily ingested by both young and old, as well as those incapable of adhering to a solid diet.
[0010] Information relevant to attempts to address these problems can be found in U.S. Pat. No. 5,922,692. This reference generally discloses methods of manufacturing glucosamine and chondroitin to be added to foodstuffs. However, this reference suffers from the disadvantage of a final product that simply adds the chondroitin and glucosamine to foodstuffs without consideration of the taste characteristics encountered by the consumer, or whether these ingredients may affect the final products' physical attributes. In particular, the formulations that include glucosamine and chondroitin do not take into account the effect these supplements have on the taste of a food product and fail to address the need to make the product more appealing to human consumers.
[0011] For the foregoing reasons, there is a need for a simple, inexpensive, lightweight and easily ingestible food product which consumers will enjoy eating. In addition, that food product must take into account the special problems created by the addition of proteoglycan precursors to food in order for the product to appeal to consumers while maintaining its physical attributes.
SUMMARY OF THE INVENTION
[0012] Due to the existing need for a product that supplements chondroitin and/or glucosamine intake by persons in need of such supplementation, a brief summary of the present invention is presented. Some simplifications and omissions may be made in the following summary, which is intended to highlight and introduce some aspects of the present invention, but not limit its scope. Detailed descriptions of a preferred exemplary embodiment adequate to allow those of ordinary skill in the art to make and use the invention concepts will follow in later sections.
[0013] A settable food product is disclosed which generally comprises a natural or synthetic non-gelatin gelling agent with the addition of a proteoglycan precursor and a liquid, which is characterized by its ability to set the combined food product.
[0014] Additionally, a method is disclosed for making a settable food product by providing a non-gelatin gelling agent along with a proteoglycan precursor and a liquid having an ability to set the combined food product. The composition is then combined to produce an edible food product.
[0015] Further, a method of administering a food product containing a proteoglycan precursor is disclosed. An easily ingested food product containing proteoglycan precursors, a non-gelatin gelling agent and a liquid capable of setting these ingredients is prepared with sufficient proteoglycan precursors to supplement the diet of a person in need thereof. The food product is then administered either in one dosage, or in multiple dosages.
DESCRIPTION OF THE INVENTION
[0016] One embodiment of the present invention comprises a product designed to help consumers supplement their diet with proteoglycan precursors. In particular, the invention is a settable food product fortified with proteoglycan precursors. Two proteoglycan precursors, glucosamine and chondroitin may be major components of the composition. As described above, glucosamine and chondroitin have shown pain relieving and other beneficial qualities, especially in the treatment of joint related ailments.
[0017] The settable food product composition will generally include a natural or synthetic non-gelatin gelling agent, one or more proteoglycan precursors, a liquid, and additives affecting the taste and appearance of the product. These additives may include, but are not limited to, edible acids, buffers, sweeteners, natural and artificial flavors and coloring agents.
[0018] The settable food product may take a variety of forms. The food product may be sold in ready to eat forms or comprise a dry mix that requires preparation by the consumer. The settable food product may include but is not limited to any one of the following: a ready to eat or pudding dry mix, pudding, instant pudding, pie filling, or pie filling mix.
[0019] Gelling agents are used to help set the food product after it has been dissolved in a liquid. Natural or synthetic gelling agents may include but are not limited to starch, and pregelatinized modified starch.
[0020] There are a number of proteoglycan precursors that may be used in the composition, either alone or in combination. One such precursor is glucosamine and effective salts thereof. This may include, but is not limited to, chitosamine, glucosamine sulfate, glucosamine hydrochloride, glucosamine iodide, and N-Acetylglucosamine, and mixtures thereof. Another such precursor is chondroitin 4-sulfate, chondroitin 6-sulfate and chondrosine, and mixtures thereof. The amount of proteoglycan precursors must be carefully measured in order to achieve the desired flavor and settable characteristics of the food product.
[0021] In addition, this invention also includes the above composition which further includes an appropriate amount of haluronic acid. Haluronic acid is well-known in the art.
[0022] A number of edible acids may be used in the composition. As shown in U.S. Pat. No. 2,519,961, edible acids control the proper pH of the product and add a desired tart taste. These edible acids may include, but are not limited to citric acid, adipic acid, tartaric acid, ascorbic acid, isoascorbic acid, malic acid, and erythorbic acid, and mixtures thereof.
[0023] A buffer salt may also be included in order to modify the pH, the setting and the melting characteristics of the food product. Such buffer salts include but are not limited to citrates, tartrates, phosphates and pyrophosphates.
[0024] Both natural and synthetic sweeteners may be used in the food product. Sweeteners add taste to the product and allow it be eaten as a dessert. Also, sweeteners may be required to modify the flavor effects of the proteoglycan precursors in the food product. Natural sweeteners may include, but are not limited to sucrose, glucose, fructose, mannitol, dextrose, and mixtures thereof. Artificial sweeteners may include, but are not limited to, saccharin, aspartame, and acesulfame, and mixtures thereof.
[0025] A number of other additives may be added to modify the taste, color, texture, or other factors that affect consumer appeal of the food product.
[0026] An exemplary cold to ambient environment has a temperature ranging from about 4ยฐ C. to about 30ยฐ C.
[0027] For purposes of describing embodiments of the present invention, examples are provided to further illustrate the invention.
EXAMPLE 1
[0028] A naturally or artificially flavored dry powder pudding or pie filling mix is prepared with the following ingredients:
TABLE 1 Dry Mix Grams Per Serving Range Preferred Sugar 15-25 20 Modified Starch 20-30 25 Natural & Artificial Flavors 1.5-2.5 2 Salt 0.05-0.15 0.1 Mono Diglycerides 0.1-0.2 0.15 Color Yellow #5 0.001 0.001 Color Yellow #6 0.001 0.001 Carrageenan Gum 0.5-1.0 0.5 Glucosamine 0.5-3.0 0.75 Chondroitin Sulfate 0.4-2.4 0.60 Milk 0.0 0.0 Total 49.102
[0029] The above ingredients are prepared in the following manner. Sugar and all ingredients except for starch are blended for 5 minutes, starch is added and blended for 15 minutes. Sugar can be replaced by artificial sweeteners such as aspartame and acesufame-K for the purpose of making a sugarless food product. Natural and artificial flavors can include vanilla, chocolate, coconut or various fruit flavors. The milk can be non-fat, 1%, 1ยฝ%, 2%, whole milk or a non-dairy milk equivalent. The color can also be varied as desired. Once the dry mix is prepared, it is packaged for consumer use. For multiple servings, multiply the single serving amount by the desired servings. The recipe for consumer use further states: add 120 grams of milk to the powder mix and heat to a boil, and then refrigerate the product until cool.
EXAMPLE 2
[0030] A naturally or artificially flavored pudding or pie filling mix in ready to eat form is prepared with the following ingredients:
TABLE 2 Ready to Eat Grams Per Serving Range Preferred Sugar 15-25 20 Modified Starch 20-30 25 Natural & Artificial Flavors 1.5-2.5 2 Salt 0.05-0.15 0.1 Mono Diglycerides 0.1-0.2 0.15 Color Yellow #5 0.001 0.001 Color Yellow #6 0.001 0.001 Carrageenan Gum 0.5-1โโ 0.5 Glucosamine 0.5-3.0 0.75 Chondroitin Sulfate 0.4-2.4 0.60 Milk 100-140 120 Total 169.102
[0031] The above ingredients are prepared in the following manner. All ingredients are added to cold milk and agitated at a high level for 5 minutes. Heat mixture to 280 degrees Fahrenheit, then cool to 900-100 degrees Fahrenheit and pack for consumer use. Sugar can be replaced by artificial sweeteners such as aspartame and acesufame-K for the purpose of making a sugarless food product. Natural and artificial flavors can include vanilla, chocolate, coconut or various fruit flavors. The milk can be non-fat, 1%, 1ยฝ%, 2%, whole milk or a non-dairy milk equivalent. The color can also be varied as desired. For multiple servings, multiple the single serving amount by the desired servings.
EXAMPLE 3
[0032] A naturally or artificial flavored pudding or pie filling mix with a very short preparation time similar to โinstant puddingโ is prepared with the following ingredients:
TABLE 3 Instant Pudding Grams Per Serving Range Preferred Sugar 15-25 20 Pregelatinized Modified Starch 3.0-4.0 3.5 Natural and Artificial Flavor* 1.5-2.5 2 Salt 0.05-0.15 0.1 Disodium Phosphate 0.3-0.5 0.4 Tetrasodium Pyrophosphate 0.3-0.5 0.4 Mono Diglycerides 0.1-0.2 0.1 Color Yellow #5 0.001 0.001 Color Yellow #6 0.001 0.001 Glucosamine 0.5-3.0 0.75 Chondroitin Sulfate 0.4-2.4 0.60 Total 27.852
[0033] The above ingredients are prepared in the following manner. All ingredients except starch are blended for 5 minutes. Starch is then added and the mixture is blended for 15 minutes. Glucosamine and Chondroitin levels must be limited below 1.5 and 1.2 grams respectively due to the salty taste that occurs above those levels. Sugar can be replaced by artificial sweeteners such as aspartame and acesufame-K for the purpose of making a sugarless food product. Natural and artificial flavors can include vanilla, chocolate, coconut or various fruit flavors. The color can also be varied as desired. Once the dry mix is prepared it is packaged for consumer use. For multiple servings, multiply the single serving amount by the desired servings. The recipe for consumer use further states: blend powder mix with ยฝ cup cold milk for 2 minutes, then refrigerate for 5-10 minutes. The milk can be non-fat, 1%, 1ยฝ%, 2%, whole milk or a non-dairy milk equivalent.
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A food product for supplementing the proteoglycan precursor intake of humans suffering from joint related ailments and a method of making and administering such a food product is disclosed. More specifically, a settable food product, supplemented with glucosamine and chondroitin, which comes in a suitable form, e.g., a pudding or pie filling, is disclosed, along with a method of making and administering the product to persons in need thereof.
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This application is a continuation of application Ser. No. 08/078,983, filed on Jun. 16, 1993, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to the field of telecommunications, and more specifically, to the field of automatic gain control circuits for cellular telephones.
Automatic gain control (AGC) circuits are well known in both analog cellular telephones and digital cellular telephones, including code division multiple access (CDMA) cellular telephones. It is often necessary to vary the amount of gain applied to signals received at the cellular telephone for proper analysis and processing of received signals. Such control of the gain of received signals is particularly important with digital communication methods. Particularly with CDMA systems, it is also well known to control the strength of signals transmitted from a cellular telephone in response to the strength of signals received by the cellular telephone. As received signal strengths increase, indicating closer proximity to a base station, transmission strengths are correspondingly lowered in view of the closer proximity. With closed loop systems, cellular telephones are responsive to commands received From a base station to raise or lower transmitted signal levels.
One common AGC method includes measuring a received signal level and comparing the received signal level to a reference level to control the gain applied to both receive and transmit portions of a cellular telephone. U.S. Pat. No. 5,107,225, issued to Wheatley, III et al, describes a cellular telephone which includes nonlinearly compensated adjustable amplifiers which are controlled in response to an integrator comparison between a reference signal and a received signal strength indication generated by a logarithmic detection device which receives signals before baseband demodulation. Although said to be capable of exhibiting rapid, high dynamic range signal power control, that device embodies a rather complex, expensive, and rigid method of providing a cellular telephone AGC function. There is, therefore, a need in the industry for an AGC circuit which addresses these and other related, and unrelated, problems.
SUMMARY OF THE INVENTION
Briefly described, the present invention includes, in its most preferred embodiment, a new closed loop AGC circuit for a digital side of a dual mode cellular telephone. The AGC circuit of the preferred embodiment of the present invention, in one inventive aspect, takes advantage of an understanding of actual signal strength variations within an automatic gain-controlled receiver portion of a cellular telephone. Since the degree of signal strength fluctuation at a signal strength detection point within an AGC circuit is felt to be relatively small during actual operation, the AGC circuit of the present invention is able to provide quality gain control through a system with a low level of complexity and expense.
According to the preferred embodiment of the present invention, receiver and transmitter adjustable amplifiers are controlled by a linear feedback control system including a linear signal level detector which determines signal levels after a receiver baseband demodulator stage. By analyzing post-baseband signals, as opposed to analyzing signals from earlier stages, the AGC circuit of the present invention is less rigid and better able to adapt to changes and variations in preceding components. The linear signal level detector receives a signal at an AC signal level and produces, through an averaging process, a DC received signal strength indication at a DC signal level which is linearly proportional to the AC signal level. The received signal strength indication is compared to a reference signal to produce a gain control signal which is linearly inverted and supplied as a receive gain control signal to the receiver adjustable amplifiers. The gain control signal is also combined with a transmit adjust signal received from the base station and supplied as a transmit gain control signal to the transmitter adjustable amplifiers.
It is therefore an object of the present invention to provide a new AGC circuit for a cellular telephone.
Another object of the present invention is to provide a cellular telephone AGC circuit with low complexity, cost, and rigidity.
Another object of the present invention is to provide a new closed loop AGC circuit for a digital side of a dual mode cellular telephone.
Yet another object of the present invention is to provide a dual mode cellular telephone with separate analog and digital sides which utilize independent automatic gain control circuits.
Still another object of the present invention is to provide a cellular telephone AGC circuit with a linear feedback control system.
Still another object of the present invention is to provide a cellular telephone AGC circuit with a linear signal level detector.
Still another object of the present invention is to provide a cellular telephone AGC circuit with post-baseband input.
Other objects, features and advantages of the present invention will become apparent upon reading and understanding the present specification, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram representation of an automatic gain control circuit in accordance with the preferred embodiment of the present invention with portions of cellular receiver and transmitter sections.
FIGS. 2-6 are schematic representations of portions of the automatic gain control circuit of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in greater detail to the drawings in which like numerals represent like components throughout the several views, FIG. 1 shows an automatic gain control (AGC) circuit 10 and other components comprising a partial cellular receiver section 12 and a partial cellular transmitter section 14. An antenna 18 is connected to a duplexer 20, both of which are connected as part of the partial cellular receiver section 12 and the partial cellular transmitter section 14. The duplexer 20 is shown connected to supply radio frequency (RF) signals to a receive RF amplifier 22 in the partial cellular receiver section 12. A radio frequency-to-intermediate frequency (RF/IF) downconverter 25 is connected to the RF amp 22 to receive RF signals and output IF signals on an IF line 25. The preferred embodiment of the present invention is designed for implementation in a dual mode cellular telephone, thus both FM and code division multiple access (CDMA) digitally encoded signals are processed through the antenna 18, duplexer 20, RF amp 22, and RF/IF downconverter 24. However, after the RF/IF downconverter 24, the FM signals and the digitally encoded signals are processed along different paths. Accordingly, the IF line 25 is shown connected to two circuital blocks, an IF amplifier & band pass filter (BPF) section 26 and an FM IF amplifier 28. The FM IF amplifier 28 supplies FM IF signals along an FM IF receive line 30 to conventional FM elements of a cellular telephone (not shown), as would be understood by one reasonably skilled in the art.
The IF amplifier & BPF section 26 is shown connected through a signal input line 33 to a receiver adjustable IF amplifiers section 34. A signal output line 36 is shown supplying signals output flora the receiver adjustable IF amplifiers section 34 to an IF/IF downconverter 38. An IF line 40 couples output from the IF/IF downconverter 38 to a baseband demodulator 42. Signals flow from the baseband demodulator 42 along an I-channel baseband line 44 and a Q-channel baseband line 45 to an I-channel analog to digital (A/D) converter 46 and a Q-channel A/D converter 47, respectively. I-channel samples of digital data and Q-channel samples of digital data are output from the A/D converters 46 and 47, respectively, to digital processing elements (not shown), as would be understood by one reasonably skilled in the art.
The I-channel baseband line 44 is also shown connected to an I-channel modulator 50. A remodulated IF line 52 is shown providing output from the I-channel modulator 50 to a linear amplifier 54 from which an amplified IF line 56 provides amplified signals to a linear detector 58. A received signal strength indication (RSSI) line 60 connects the linear detector 58 to a comparator 62 which also receives input from an automatic gain control (AGC) reference line 64. A gain control signal line 66 supplies output from the comparator 62 to both a linear inverter 68 which is connected to the receiver adjustable IF amplifiers section 34 through a receive gain control signal line 70 and a negative summer 72 which also receives input from a transmitter adjustment line 74 and provides output through a transmit gain control signal line 76 to transmitter adjustable IF amplifiers 78 of the partial cellular transmitter section 14.
I/Q data lines 80 supply digital signals from digital processing elements (not shown) to digital to analog (D/A) converters 82 which supply analog signals to baseband modulator 84. An IF/IF upconverter 86 receives signals from the baseband modulator 84 and provides input to the transmitter adjustable IF amplifiers 78 through a signal input line 87. An FM IF transmit line 88 is shown providing input front conventional FM cellular components (not shown) to an FM IF transmit amplifier 89 which, through an amplified FM IF transmit line 90, provides additional input to the transmitter adjustable IF amplifiers 78. A signal output line 91 supplies signals from the transmitter adjustable IF amplifiers 78 to an IF/RF upconverter 92 which provides output to a transmit RF amplifier 94 which is connected to the duplexer 20 to transmit through the antenna 18.
Analysis of the operation of the preferred embodiment of the present invention as shown in FIG. 1, and further detailed in subsequent FIGURES, begins and ends with the antenna 18. Depending on the type of communication being used at any given time, FM or CDMA signals are received and transmitted through the antenna 18 and the duplexer 20. When receiving signals through the antenna 18 from a base station (not shown), the duplexer 20 directs the signals to the receive RF amplifier 22 of the partial cellular receive section 12, whereas signals received from the transmit RF amplifier 94 of the partial cellular transmit section 14 are directed to the antenna 18 for transmission. Since signals received by the duplexer 20 from the transmit RF amplifier 94 are typically in a frequency range different from signals received from a base station through the antenna 18, the duplexer 20 includes a plurality or band pass and band reject filters (not shown) which assist in the duplexing function.
The receive RF amplifier 22 amplifies signals from the duplexer 20 at a predetermined gain. Elements of the receive RF amplifier 22 (not shown) include, according to the preferred embodiment of the present invention, an appropriately biased bipolar transistor, various stripline inductors, and an AC-coupled band pass filter. The RF/IF downconverter 24 converts RF signals (such as those in an exemplary range of 881 MHz, plus or minus 12 MHz) into corresponding IF signals (such as those in an exemplary range of 70 MHz, plus or minus 600 kHz for digital signals, and plus or minus 15 kHz for FM signals). Elements of the RF/IF downconverter 24 (not shown) include, according to the preferred embodiment of the present invention, a secondary frequency source, such as a voltage-controlled oscillator (VCO) for generating a receive-LO (local oscillator) frequency, in combination with a phase lock loop (PLL) to ensure proper frequency generation, and a bandpass filter, providing input to an appropriately biased bipolar transistor. Further details of construction and operation of the duplexer 20, receiver RF amplifier 22, and the RF/IF downconverter 24 would be understood by one reasonably skilled in the art. The FM IF amplifier 28 is shown amplifying FM IF signals for further conventional FM processing.
The next stages in the digital side of the partial cellular receiver section 12 are the IF amplifier & BPF section 26 and the receiver adjustable IF amplifiers section 34, which are shown in greater detail in FIG. 2. The IF line 25 is shown providing input to the IF amplifier & BPF section 26 which is connected to the receiver adjustable IF amplifiers section 34 through the signal input line 33. An additional input to the receiver adjustable IF amplifiers section 34 is shown coming from FIG. 5 through the receive gain control signal line 70, and output from the receiver adjustable IF amplifiers section 34 is shown proceeding to elements of FIG. 3 through the signal output line 36. According to the preferred embodiment of the present invention, the IF amplifier & BPF section 26 includes an appropriately biased dual gate Gallium-Arsenide (GaAs) FET 110 which is AC-coupled to a surface acoustic wave (SAW) band pass filter (BPF) 112. In the preferred embodiment of the present invention, one example range of frequencies of signals on the signal input line 33 is 70 MHz, plus or minus 600 kHz.
The receiver adjustable IF amplifiers section 34 includes two AC-coupled dual gate GaAs FET's 114 and 116. One gate of each FET 114 and 116 is coupled as a signal input, and the other is coupled as a gain control input. The source of each FET 114, 116 is coupled to ground through parallel resistor, capacitor combinations, and the drain of each FET 114, 116 is coupled as a signal output. The receive gain control signal line 70 is shown connected through a resistor 120 to the gain control input gate of FET 116 and through a resistor 122 to the gain control input gate of FET 114. As the signal level on the receive gain control signal line 70 varies, as is discussed below in detail, the voltage at the gain control input gate of each FET 114, 116 varies accordingly to vary the amount of gain applied by each FET 114, 116. Consequently, the overall gain applied by the receiver adjustable IF amplifiers section 34 to the signals on the signal input line 33 to produce the signals on the signal output line 36 is controlled by the receive gain control signal line 70.
Referring briefly back to FIG. 1, the signal output line 36 is shown connecting the receiver adjustable IF amplifiers section 34 to the IF/IF downconverter 38 which converts the signals receive on the signal output line 36 to corresponding signals at a different intermediate frequency on IF line 40. With reference to FIG. 3, the IF/IF downconverter 38 is shown in greater detail. A mixer 130 is shown connected through configuring components to a phase lock loop (PLL) 132. One example of an acceptable mixer 130 is the SA602A from Signetics Corporation of Sunnyvale, Calif., and one example of an acceptable PLL 132 is the MC145170 from Motorola, Inc. of Schaumburg, Ill.. The PLL 132 continuously re-tunes the mixer 130 which mixes the IF signals on signal output line 36 with a second receiver-LO signal to output signals with, in accordance with the preferred embodiment of the present invention, a median frequency of 4.95 MHz. Another GaAs FET 134 with appropriate biasing elements is AC-coupled to the output of the mixer 130 to provide any necessary gain at a constant level to the signals output from the mixer 130. The IF line 40 is AC-coupled to the output of the GaAs FET 134.
Referring again briefly to FIG. 1, the IF line 40 connects the IF/IF downconverter 38 to the baseband demodulator 42. As discussed above, signals flow from the baseband demodulator 42 through the A/D converters 46, 47 and, in part, through the I-channel modulator 50, the linear amplifier 54, and the linear detector 58. Refer now to FIG. 4, which shows the baseband demodulator 42, the I-channel modulator 50, the linear amplifier 54, and the linear detector 58 in greater detail. Signals on the IF line 40 flow through an AC-coupled attenuating resistor network 140 and then into parallel mixer lines headed by a Q-channel mixer 142 followed by a low pass filter (LPF) 146, and an I-channel mixer 144 followed by a low pass filter (LPF) 148. The baseband signals from the LPF's 148, 146 are AC-coupled through capacitors 152, 150, respectively, to A/D converters 46, 47, respectively. Digital signals are then supplied to digital processing elements (not shown) through receive I-channel data lines 48 and receive Q-channel data lines 49. The I-channel baseband line 44 is shown also connected to the I-channel modulator 50, shown including an I-channel mixer 160. Although indicated as separate elements, one example of an acceptable device comprising the Q-channel fixer 142, I-channel mixer 144, LPF's 146, 148, A/D converters 46, 47, and I-channel modulator 50 is the CDMA Baseband Analog ASIC (application specific integrated circuit) available from Qualcomm, Inc. of San Diego, Calif. In other embodiments of the present invention, individual components are used, and in others, the I-channel modulator 50 is omitted such that the I-channel baseband line 44 is connected directly to the linear amplifier 54.
Signals received along the remodulated IF line 52 are linearly amplified by the linear amplifier 54. A capacitor 170 blocks any DC in signals on the remodulated IF line 52. Biasing elements 172, 174, 176, 178, and 180 are sized to bias a bipolar transistor 190 in the active amplification region so that a constant amount of gain is applied between the base and the collector of the bipolar transistor 190 which is connected to the amplified IF line 56. One example of an acceptable bipolar transistor is the BC848 from Motorola, Inc. Thus, the term "linear amplification" is understood to refer to amplification which is linear, rather than logarithmic, etc., over a given range of input values.
The amplified IF line 56 connects the linear amplifier 54 to the linear detector 58. The amplified IF line 56 is connected to a capacitor 200 which is further connected to the cathode of a diode 202 with a grounded anode and to the anode of diode 204. The cathode of the diode 204 is connected to a grounded resistor 206 and a resistor 210 which is connected to the RSSI line 60. A grounded capacitor 212 is also connected to the RSSI line 60. In general, the linear detector 58 receives signals at AC signal levels on the amplified IF line 56 and outputs DC signals on the RSSI line 60 with DC levels which are linearly proportional to the AC signal levels.
Typically, a signal travelling over amplified IF line 56 has an AC and a DC component. Since capacitor 200 is connected in series (AC-coupled) with the remainder of the linear detector 58, capacitor 200 remove the DC component from the signal supplied from the amplified IF line 56. The capacitor 200 also cooperates with the diodes 202, 204 to add a new DC level to the AC component which is linearly proportional to the incoming AC signal level. As the AC signal level rises, the capacitor 200 is charged, and when the AC signal level falls, the diode 202 turns on, resulting in an upward voltage shift. Resistor 210 and capacitor 212 function as a low pass filter to remove the remaining AC component to leave a DC signal which is linearly proportional to the AC signal level of the signal on the amplified IF line 56. In addition, the resistor 210 functions as an averaging means to slow the charge of capacitor 212 so that the output on the RSSI line 60 is an averaged linear output. The resistors 206 and 210 are, in the preferred embodiment of the present invention, approximately equal in value.
Referring again briefly to FIG. 1, the RSSI line 60 is shown connecting the linear detector 58 to the comparator 60, which also receives input from the AGC REF line 64 and provides output along gain control signal line 66. Gain control signal line 66 is shown providing input to the linear inverter 68 which provides output along the receive gain control signal line 70, and further providing input, along with the TX ADJ line 74, to the negative summer 72 which provides output along the transmit gain control signal line 76. Refer now to FIG. 5, which shows these elements in greater detail. The RSSI line 60 is shown supplying signals through a biasing resistor 220 to the non-inverting input of an operational amplifier (op amp) 222, which input is also connected to biasing resistors 224, 226, and 228. The AGC REF (automatic gain control reference) line 64, which is connected to elements (not shown) which generate a desired reference signal level, is shown providing signals through a network of biasing resistors 230, 232 and 234 to the inverting input of op amp 222. The output and inverting input of the op amp 222 is shown connected through resistor 236 and capacitor 238 so that the op amp 222 functions as an open loop integrator to produce a gain control signal on the gain control signal line 66 equal to the difference between the signal levels on the RSSI line 60 and the AGC REF line 64.
The linear inverter 68 is shown receiving the gain control signal line 66 and providing output through the receive gain control signal line 70. The gain control signal line 66 is shown connected through a resistor 250 to the inverting input of an op amp 252. A resistor 254 is shown connected between the output and inverting input of the op amp 252, whereas the non-inverting input of the op amp 252 is grounded. Thus, the op amp 252 functions as an inverting amplifier operating in a linear manner without undue complexity. The negative summer 72 is shown receiving signals on the gain control signal line 66 and the TX ADJ (transmit adjust) line 74, and producing output on the transmit gain control signal line 76. The gain control signal line 66 and the TX ADJ line 74 are, after various resistors, connected together at the inverting input of an op amp 260 which is biased to amplify and invert the sum of the two input signals and provide output on the transmit gain control signal line 76.
Referring again to FIG. 1, after the I/Q data signals are converted from digital signals into analog signals by the D/A converters 82, modulated into intermediate frequencies by the baseband modulator 84, and upconverted into a higher intermediate frequency by the IF/IF upconverter 86, the transmit signals are provided to the transmitter adjustable IF amplifiers section 78 through the signal input line 87. Although not shown, the D/A converters 82 and baseband modulator 84 include I-channel and Q-channel elements handling each channel separately in a manner similar to the partial cellular receiver section 12. FM signals are also provided to the transmitter adjustable IF amplifiers section 78 through the amplified FM IF transmit line 90 after being amplified by the FM IF amplifier 89. After being amplified by the transmitter adjustable IF amplifiers section 78, signals (either FM or CDMA) are transmitted along the signal output line 91 to the IF/RF upconverter 92 which converts the IF signals to corresponding RF signals which are then amplified by the RF amp 94 and provided to the duplexer 20 for transmission on the antenna 18, as discussed above.
Referring now to FIG. 6, which shows the transmitter adjustable IF amplifiers section 78 in greater detail, the signal input line 87 is connected to one gate of a dual gate GaAs FET 270, whose output is coupled to one gate of another dual gate GaAs FET 272, whose output is connected to the signal output line 91. The other gate of the dual gate GaAs FET 270 is connected through a resistor 274 to the transmit gain control signal line 76 which is also connected through a resistor 276 to the other gate of the dual gate GaAs FET 272. When functioning in a CDMA mode, the FET's 270 and 272 function in a manner similar to the FET's 114, 116 of FIG. 2 of the receiver adjustable IF amplifiers section 34 in that the gain applied between the signal input line 87 and the signal output line 91 is adjusted according to levels on the transmit gain control signal line 76. When FM signals are being amplified by the transmitter adjustable IF amplifiers section 78, a mode voltage effectively disables the first FET 270, and the signals on the amplified FM IF transmit line 90 override those from the transmit gain control signal line 76 so that the second FET 272 amplifies the FM IF signals by a constant gain.
While the embodiments of the present invention which have been disclosed herein are the preferred forms, other embodiments of the present invention will suggest themselves to persons skilled in the art in view of this disclosure. Therefore, it will be understood that variations and modifications can be effected within the spirit and scope of the invention and that the scope of the present invention should only be limited by the claims below.
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A closed loop AGC circuit for a digital side of a dual mode cellular telephone wherein receiver and transmitter adjustable amplifiers are controlled by a linear feedback control system including a linear signal level detector which determines signal levels after a receiver baseband demodulator stage. The linear signal level detector receives a signal at an AC signal level and produces, through an averaging process, a DC received signal strength indication at a DC signal level which is linearly proportional to the AC signal level. The received signal strength indication is compared to a reference signal to produce a gain control signal which is linearly inverted and supplied as a receive gain control signal to the receiver adjustable amplifiers. The gain control signal is also combined with a transmit adjust signal received from the base station and supplied as a transmit gain control signal to the transmitter adjustable amplifiers.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to devices and processes for hybridizing nucleic acid samples, and more particularly, to an automated device for hybridizing DNA microarrays.
[0003] 2. Discussion
[0004] Use of DNA (deoxyribonucleic acid) microarrays provides a powerful technique to analyze expression of thousands of genes simultaneously. The technique includes immobilizing DNA samples from large numbers of genes on a solid substrate, such as a glass microscope slide. The DNA samples appear as an array of spots on the substrate, and one can determine the origin of a particular DNA sample by knowing its position in the array. The technique typically provides contacting the DNA microarray with RNA (ribonucleic acid) probes to detect specific nucleotide sequences in the DNA samples. To distinguish between different RNA probes, each is labeled with a tag that fluoresces at a wavelength that is unique for the particular probe.
[0005] Under proper conditions, the RNA probes will hybridize or bind to the immobilized DNA samples, resulting in hybrid DNA-RNA strands. For each of the immobilized DNA samples, and for a particular RNA probe, one can discern differences in hybridization among DNA samples by measuring the intensity and the wavelength dependence of fluorescence of each microarray element. In this way, one can determine whether gene expression levels vary among DNA samples. Thus, using DNA microarrays, one can learn much about expression of a large number of genes, and about comprehensive patterns of gene expression, using relatively small amounts of biological material.
[0006] Although DNA microarrays are powerful tools, instruments currently available to hybridize DNA microarrays need improvement. Most instruments that can process DNA microarrays have rudimentary temperature control. But nucleic acid hybridization demands precise temperature control. Rates of hybridization and equilibrium concentrations of hybrid DNA-RNA strands depend strongly on temperature and therefore accurate comparisons among hybridization experiments require that the experiments be run at the same temperature. In addition, precise temperature programming during an experiment is often critical to minimizing spurious probe-sample binding. For example, rapidly decreasing temperature following hybridizationโa process called step-wise probe annealingโreduces background binding.
[0007] Generally, instruments that can process DNA microarrays also lack an adequate system for controlling fluid contacting. During hybridization, the DNA microarray is immersed in a fluid that contains the RNA probes. The rate at which the probes bind to the DNA samples will depend, in part, on the concentration of the probes. However, the concentration of the probes near the immobilized DNA samples may be much different than the bulk concentration of the probes. Although agitating the fluid helps minimize concentration gradients between the bulk fluid and fluid next to the substrate surface, excessive fluid mixing may create high shearing and normal forces that may dislodge the DNA samples.
[0008] The present invention overcomes, or at least reduces, one or more of the problems set forth above.
SUMMARY OF THE INVENTION
[0009] The present invention provides a DNA hybridization apparatus capable of precise thermal and fluid control. The present invention is particularly useful when used in conjunction with DNA spotted glass slides (DNA microarrays). The apparatus can also be used for hybridizing other materials on other substrates. Multiple slides can be processed at one time (in parallel) or in rapid serial fashion. A fluid manifold allows for control of multiple fluids across the surface of each slide. All slides can contact the same sequence of fluids or may undergo different fluid contacting protocols. Thermal control is by slide pair, so that each slide pair undergoes the same temperature profile or different pairs can have different temperature programming. Small volumes of liquids can be manually applied to each of the slides. Each slide pair is provided with separate clamping mechanisms to seal DNA sample areas of each slide. Fluids are moved under negative pressure throughout the instrument, ensuring that no dangerous chemicals can be ejected under pressure. The present invention also provides for software control of fluid contacting and temperature using software running on an embedded personal computer. User input is by touchscreen or a floppy disk drive. A system network distributes control signals and software between the master and satellite units and the thermal control module for each slide pair.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 shows a perspective front view of one embodiment of an automated DNA hybridization apparatus for use with DNA microarrays.
[0011] [0011]FIG. 2 shows a perspective top view of one of a slide plate assembly.
[0012] [0012]FIG. 3 shows a cross-sectional side view of a slide plate assembly and clamp.
[0013] [0013]FIG. 4 shows a perspective top view of a slide carrier and the pair of glass slides (DNA microarrays).
[0014] [0014]FIG. 5 shows a perspective bottom view of a slide cover.
[0015] [0015]FIG. 6 shows a phantom top view of a master manifold.
[0016] [0016]FIG. 7 shows a phantom bottom view of a satellite manifold.
[0017] [0017]FIG. 8 is a schematic of a fluid control module.
[0018] [0018]FIG. 9 illustrates fluid agitation within a slide cavity using valve actuation.
[0019] [0019]FIG. 10 shows an exploded view of a temperature management module.
[0020] [0020]FIG. 11 shows a schematic diagram of a control subsystem for each of the thermal management modules.
DETAILED DESCRIPTION
Overview
[0021] [0021]FIG. 1 shows a perspective front view of one embodiment of an automated DNA hybridization apparatus 100 for use with DNA microarrays (glass microscope slides spotted with DNA). The apparatus 100 shown in FIG. 1 includes a housing 102 that contains six thermal management modules 104 , though the number of thermal management modules 104 can vary. Each of the thermal management modules 104 controls the temperature of one of six slide plate assemblies 106 . Each of the slide plate assemblies 106 includes a pair of glass microscope slides (not shown) spotted with DNA. During processing, each pair of glass microscope slides can undergo different temperature programming since the thermal management modules 104 can operate independently.
[0022] During hybridization, a fluid control module 108 distributes various liquids (buffers, reagents, and the like) and various gases (air, for example) to each glass slide. The fluid control module 108 includes a master manifold 110 , which is in fluid communication with a first row 112 of slide plate assemblies 106 , and a satellite manifold 114 , which is in fluid communication with a second row 116 of slide plate assemblies 106 . The master manifold 110 and the satellite manifold 114 contain valves and conduits (not shown) that allow fluid flow from liquid reservoirs 118 to individual glass slides. In addition, the master manifold 110 and the satellite manifold 114 allow fluid flow from individual glass slides to waste containers 120 . Use of two waste containers 120 obviates the need to mix reactive wastes or to change collection vessels during processing. As described below, each of the DNA microarrays may contact the same or different fluids during hybridization. A pump (not shown) maintains vacuum within headspaces of the two waste containers 120 . Ambient pressure in the liquid reservoirs 118 and vacuum within the waste containers 120 , results in a pressure drop that drives fluid flow throughout the fluid control module 108 . Since all fluid contacting within the apparatus 100 occurs at below-ambient pressure, no dangerous chemicals can be ejected from the apparatus 100 under pressure.
[0023] Thermal management and fluid contacting are under the control of software running on an embedded personal computer (PC) module 122 . User input is by touchscreen 124 or a floppy disk drive 126 . A proprietary system network distributes control signals and software instructions among the master manifold 110 , the satellite manifold 114 , and the thermal management modules 104 for each of the slide plate assemblies 106 . The user can program processing steps on the apparatus 100 via application software and either touchscreen 124 or floppy disk drive 126 . Process control programs entered on the touchscreen 124 can be stored on the embedded PC module 122 hard drive or downloaded to the floppy disk drive 126 .
[0024] Though not shown in FIG. 1, the apparatus 100 also includes a power supply module. The power supply module, under the control of the embedded PC module 122 , provides current to actuate valves on the master 110 and satellite 114 manifolds, and provides energy to power each of the thermal management modules 104 . Because line voltage limits available current to about 10 amps, the power supply module cannot provide power to all of the thermal management modules 104 simultaneously without severely diminishing heating or cooling rate. Instead, the power supply module uses intelligent energy scheduling by first providing power to one or two of the slide plate assemblies 106 . After they attain their desired temperatures, the power supply module provides power to a second group of slide plate assemblies 106 . This process continues until all of the slide plate assemblies 106 reach their desired temperatures.
Fluid Control Module
[0025] [0025]FIG. 2 and FIG. 3 show, respectively, a perspective front view and cross-sectional side view of one of the slide plate assemblies 106 . As shown in FIG. 2, the slide plate assembly 106 includes a slide cover 150 that is held in place with a clamp 152 . The clamp 152 is a generally rectangular frame 154 having a single, mid-span cross member 156 . The rectangular frame 154 is mounted on a pair of clamp arms 158 , 160 using a cylindrical rod 162 that allows the rectangular frame 154 to pivot about the centerline of the cylindrical rod 162 . First ends of the clamp arms 158 , 160 are pivotably mounted on hinges 164 , 166 , which are fastened to the thermal management module 104 ; a rectangular bar 168 attached to second ends of the clamp arms 158 , 160 prevents relative movement of the clamp arms 158 , 160 . To secure the slide plate assembly 106 , a knob 170 , which is mounted on the rectangular bar 168 , is threaded into a clamp base 172 which is attached to the thermal management module 104 .
[0026] As shown in FIG. 3, the slide plate assembly 106 includes a slide cover 150 disposed above a pair of glass slides 190 that are contained on a planar, stainless steel slide carrier 192 . During processing, the slide cover 150 is disposed on the glass slides 190 . The slide carrier 192 positions the glass slides 190 using a series of cut out tabs 194 that are bent upward at an angle of about 10 degrees. The cut out tabs 194 allow for slight variations in dimensions of the glass slides 190 . A U-shaped tab 196 located at one end of the slide carrier 192 engages a locator pin (not shown) on the manifolds 110 , 114 shown in FIG. 1 to fix the position the glass slides 190 and the slide carrier 192 in the apparatus 100 .
[0027] Further details of the slide plate assembly 106 are shown in FIG. 4 and FIG. 5. FIG. 4 shows a perspective top view of the slide carrier 192 and the pair of glass slides 190 . Each of the glass slides 192 is spotted with DNA in the form of an array 210 .
[0028] [0028]FIG. 5 shows a perspective view of a bottom surface 220 of the slide cover 150 . The slide cover 150 is constructed from a high temperature plastic to prevent sagging or softening at the higher operating temperatures of the apparatus 100 . A suitable plastic includes polysulfone. Polysulfone possesses the requisite temperature characteristics and is transparent, which allows direct viewing of the glass slides 190 during processing. In addition, the absorption and attenuation characteristics of polysulfone help prevent photo bleaching of the DNA microarray, RNA probes, and the like during processing.
[0029] A shim 222 , having a pair of rectangular cut outs of slightly smaller dimension than the glass slides 190 , is disposed on the bottom surface 220 of the slide cover 150 . The thickness of the shim 222 defines a standoff between the bottom surface 220 of the slide cover 150 and the glass slides 190 . Two perfluoroelastomer o-rings 224 , which are inert and will not bind to nucleic acids, are placed in grooves cut into the bottom surface 220 of the slide cover 150 around the inner periphery of the shim 222 . During processing, the bottom surface 220 of the slide cover 150 is disposed on the glass slides 190 , compressing the o-rings 224 and defining two slide cavities for fluid flow.
[0030] Referring to FIG. 3 and FIG. 5, fluid enters and exits each of the slide cavities through ports 226 located at one end of the slide cover 150 . The ports 226 provide fluid connections with manifolds 110 , 114 shown in FIG. 1, and are sealed with o-rings 228 . For each slide cavity, fluid enters one of the ports 226 into a first lateral diffusion channel 230 that is cut into the slide cover 150 . Next, fluid flows the length of the cavity along the surface of the slide 190 and dumps into in a second lateral diffusion channel 232 . From the second diffusion channel 232 , fluid flows within a return channel 234 bored in the slide cover 150 back towards the ports 226 , and exits the slide cavity through one of the ports 226 . Note that, in addition to diffusing flow, the diffusion channels 230 , 232 act as small fluid reservoirs that empty and fill as the temperature within the slide cavity rises and falls.
[0031] As shown in FIG. 3 and FIG. 5, the slide cover 150 contains two injection ports 236 for manually injecting small liquid volumes (a few microliters, say) directly into each of the slide cavities. The injection ports 236 are drilled with a taper that matches the profiles of an injection deviceโtypically a pipetteโand polyethylene plugs 238 that, as shown in FIG. 2, seal the ports 236 when not in use. The taper does not allow fluid to remain in the injection ports 236 once the plugs 238 are inserted, thus reducing the apparent volume of the slide cavity.
[0032] During manual injection, liquid is drawn into the second diffusion channel 232 by capillary action and flows across the surface of the slide 190 within the slide cavity until the liquid reaches the first diffusion channel 230 . Because manual liquid injection occurs at the second diffusion channel 232 , and the slide plate assembly 106 tilts slightly upward (about 10 degrees or so) towards the first diffusion channel 230 , the liquid displaces and expels air within the slide cavity out of the ports 226 during injection. Liquid should not completely fill both diffusion channels 230 , 232 since they are designed to compensate for thermal expansion and contraction of the fluid within the slide cavity.
[0033] Thermal breaks 238 , such as the one shown in FIG. 3, are cut into the slide cover 150 to reduce the distortion resulting from thermal gradients in a direction parallel to the bottom surface 220 of the slide cover 150 . Distortion arising from thermal gradients in a direction perpendicular to the surface 220 of the slide cover 150 are reduced by making the slide cover 150 thinner and by reducing its thermal mass.
[0034] Referring once again to FIG. 3, during processing, the clamp 152 presses the slide plate assembly 106 against elements of the thermal management module 104 โthermal plate 260 and thermal pad 262 โusing spring 264 loaded contact ferrules 266 mounted in recesses 268 in the clamp frame 154 . The contact ferrules 196 are slidably mounted on screws 270 threaded into the clamp frame 154 . The contact ferrules 266 are arranged around the clamp frame 154 so they exert a downward force that is evenly distributed along the periphery of the slide cover 150 . The applied pressure is sufficient to ground out the shim 222 against the glass slides 190 and to prevent warping of the slide cover 150 due to thermal gradients.
[0035] [0035]FIG. 6 and FIG. 7 show phantom top and bottom views, respectively, of the master manifold 110 and the satellite manifold 114 . Both manifolds 110 , 114 are formed from multi-layer, diffusion bonded acrylic, in which channels 290 , 292 , 294 , and 296 are machined into planar surfaces of acrylic layers and the layers are bonded together under heat and pressure. The master manifold 110 is similar to the satellite manifold 114 except that the master manifold 110 provides fluid connections to the liquid reservoirs 118 and waste containers 120 via liquid ports 298 and waste ports 300 , respectively. In addition, the master manifold 110 provides fluid connections to a compressed air source and to ambient air via a gas port 302 and a vent port 304 . Locator pins 306 engage the slide cover 150 and the U-shaped tab 196 of the slide carrier 192 . The locator pins 306 serve to position the slide cover 150 and slide carrier 192 relative to the manifolds 110 , 114 .
[0036] Returning to FIG. 2, first and second conduits 320 , 322 provide fluid communication between the liquid reservoirs 118 and the waste containers 120 , respectively, through first and second conduit ports 324 , 326 . In addition, valves 328 , which are mounted to the underside of the master 110 and satellite 114 manifolds, selectively provide fluid communication between the slide cavities and the liquid reservoirs 118 , waste containers 120 , compressed air, or ambient air. The valves are under control of the embedded PC module 122 , and have zero dead volume to prevent retention of liquid when closed.
[0037] [0037]FIG. 8 is a schematic of the fluid control 108 module, and illustrates how fluid moves from the liquid reservoirs 118 , through the master manifold 110 , the satellite manifold 114 , and slide cavities 350 , and into the waste containers 120 . Before fluid is introduced into the slide cavities 350 , a flow path between the liquid reservoirs 118 and the slide cavities 350 is preloaded or primed with liquid from an appropriate reservoir 118 . Priming purges any residual fluid remaining from a previous processing step that may contaminate the current processing step.
[0038] To illustrate priming, suppose one desires to inject liquid from a first reservoir 352 into a first slide cavity 354 and then into a second slide cavity 356 . Initially, all valves 328 are closed. To begin priming, the embedded PC control module 122 (not shown) opens a first liquid input valve 358 , a primary primer valve 360 , and either a first 362 or a second 364 waste valve, which fills the conduit 290 with liquid from the first reservoir 352 since the waste containers 120 are under vacuum. Next, the control module 122 opens a first slide cavity output valve 366 and closes the primary primer valve 360 , which purges the first slide cavity 354 of any residual fluid from a previous processing step. Similarly, to prime the conduit 294 providing fluid communication between the first liquid reservoir 352 and the second slide cavity 356 , the embedded PC control module 122 opens the first liquid input valve 358 , a secondary primer valve 368 , and either the first 362 or the second 364 waste valves. This process fills the conduit 294 with liquid from the first reservoir 352 . Next, the control module 122 opens a second slide cavity output valve 370 and closes the secondary primer valve 368 , which purges the second slide cavity 356 of any residual fluid from a previous processing step.
[0039] Once priming is complete, and all of the valves 328 are closed, the PC control module 122 injects liquid from the first reservoir 352 into the first slide cavity 354 by opening the first liquid input valve 358 , a first slide cavity input valve 372 , a first slide cavity pulse valve 374 , the first slide cavity output valve 366 , and either the first 362 or the second 364 waste valves. Similarly, the PC control module 122 injects liquid from the first reservoir 352 into the second slide cavity 356 by opening the first liquid input valve 358 , a second slide cavity input valve 376 , a second slide cavity pulse valve 378 , the second slide cavity output valve 370 , and either the first 362 or the second 364 waste valves.
[0040] As described above, a vacuum pump 380 maintains vacuum within headspaces of the two waste containers 120 . Ambient pressure in the liquid reservoirs 118 and vacuum within the waste containers 120 , results in a pressure drop that drives fluid flow throughout the fluid control module 108 . As the waste containers 120 fill during processing, headspace within the two waste containers 120 decreases, which diminishes pumping capacity. As a result, the vacuum pump 380 is run continuously to maintain vacuum within the fluid control module under all operating conditions. When the waste container 120 headspace is large, it allows the fluid control module 108 to respond to peak or transient pumping demands. Typically, exhaust 382 from the vacuum pump is channeled to the rear of the apparatus 100 . When the exhaust 382 is hazardous, it is piped to a location for disposal. To aid in the handling of hazardous materials, the waste containers 120 can be preloaded with a neutralizing agent.
[0041] [0041]FIG. 9 illustrates agitation of fluid 400 within one of the slide cavities 350 by valve actuation. FIG. 9 shows a cross sectional view of one of the slide plate assemblies 106 abutting the master manifold 110 . A pair of valvesโa slide cavity input valve 402 and a slide cavity pulse valve 404 โprovide fluid communication with the liquid reservoirs 118 . The embedded PC control module 122 (not shown) can agitate the fluid 400 by opening and closing the pulse valve 404 . This action draws air out of and into the first diffusion channel 230 , as shown by arrows 406 , 408 . The diffusion channel 230 acts as a pressure reservoir that tends to dampen and distribute pressure forces within the slide cavity 350 , which minimizes shearing of any DNA adhering to the slide 190 .
[0042] Fluid 400 within the slide cavities 350 often gases during heating forming bubbles that tend to collect in the first diffusion channel 230 . Gas collection in the first diffusion channel 230 is enhanced by agitation and by the slight incline of the slide plate assembly 106 . Intermittent venting of the slide cavity 350 through, for example, an output valve 366 , 377 and venting valve 420 (FIG. 8), prevents the gas from pressurizing and displacing fluid 400 . Fluid loss by evaporation is minimized by a short vent period.
Temperature Control
[0043] [0043]FIG. 10 shows an exploded view of the temperature management module 104 . The temperature management module 104 includes a thermal plate 260 that is designed and constructed to maximize heat transfer between peltier devices 440 and the glass slides 190 . The thermal plate 260 is designed to provide rapid temperature response and uniform temperature distribution across the surface of the glass slides 190 . To achieve these design goals, the thermal plate 260 has minimal thermal mass and a high degree of flatness to maximize thermal contact area. Where mechanical connections must be made to the thermal plate 260 , they are made in positions that do not cause substantial disruption to the temperature profile. The thermal plate 260 is disposed on a graphite-loaded thermal pad 262 that forms a thermal interface between the peltier devices 440 and an anodised surface of the thermal plate 260 . A thermal fuse (not shown) is bonded to the thermal plate 260 to prevent the module 104 from overheating. In addition, a PT100 temperature sensor 442 is embedded on the top of the thermal plate 260 in close proximity to the DNA sample (array) 210 to improve process control.
[0044] Each thermal transfer plate 260 is serviced by four peltier devices 440 connected electrically in series and thermally in parallel to provide low thermal impedance between the thermal plate 260 and heat sink (source) 444 . The spatial configuration of the peltier devices 440 allows compression screws (not shown) to pass between them forming a compression assembly (sandwich) with the thermal plate 260 and the heat sink 444 forming opposing sides. The positions of the compression screws provide even compression force across the peltier faces when correct torque settings are applied to the compression screws. Graphite-loaded thermal pads 262 are used to connect the peltier devices 440 to the heat sink 444 and the thermal plate 260 .
[0045] A mating face 446 of the heat sink (source) 444 has a high degree of flatness to maximize thermal contact area with the peltier devices 440 . Optimal thermal transfer to incident airflow is achieved using an efficient fin assembly (not shown) coupled to turbulent air flow preconditioned to have zero โdead zones.โ Preconditioning is achieved by moving a fan 448 a selected distance from the heat sink's 444 fins, which disrupts dead zones created by the fan's 448 stator. A temperature sensor 450 is imbedded in the heat sink 444 to supply temperature data to the embedded PC control module 128 .
[0046] Each thermal module is typically capable of temperature ramp rates of about 1ยฐ C./s, and can control temperature between about 1ยฐ C. and 100ยฐ C. Ramp rates are taken with the surface of a slide 190 in a dry condition measured on the top surface of the slide 190 .
[0047] [0047]FIG. 11 shows a schematic diagram of the thermal management module 104 control subsystem 460 . Thermal control of the sample area (DNA array) 210 of the slides 190 depends on accurate and responsive control of the peltier 440 devices. The magnitude and direction of the electrical current input into each of the peltier devices 440 controls the amount and direction of heat transfer across the devices 440 . A switching power converter 470 coupled with an H-bridge reversing switch 472 , supplies the necessary current. Current is under control of a computer processor 474 via a digital to analog (D/A) converter 476 . The temperature of the thermal plate 260 and heat sink (source) 444 is monitored using PT100 sensors 442 and a temperature converter 476 makes the result available to the processor 474 . Electrical current polarity and flow are controlled using the computer processor 474 that in turn monitors temperatures on the thermal plate 260 and the heat sink (source) 444 to calculate applied current and polarity to achieve the demand temperature. A pulse output from the heat sink 444 fan 448 is monitored to provide warning of air flow failure.
[0048] A solenoid valve driver 478 provides a link between the computer processor 474 and the valves 328 . In addition, a serial communication interface 480 provides a link between the computer processor 474 and the embedded PC control module 122 . The embedded PC control module 122 carries out scheduling of valve 328 operations and temperature changes.
[0049] Valve state and temperature change commands are sent to the thermal management module 104 via the serial communications interface 480 . The processor 474 in the thermal management module 104 is responsible for direct valve 328 operation and temperature control. For optimum processing, the latter needs to apply rapid temperature changes, quickly stabilizing at the new temperature with no overshoot. This is achieved in the present embodiment using a modeling technique, rather than a traditional proportional-integral-differential (PID) control loop.
[0050] The thermal module 104 runs a program that implements a model of the thermal characteristics of the combination of the heat sink 444 , peltier device 440 , thermal plate 260 and slides 190 . Heat pumping is modeled as a fixed transient response (of heat pump rate as a function of time), pumping efficiency (steady-state pump rate as a function of peltier current) and heat loss/gain from the thermal plate 260 , through the peltier device 440 to the heat sink 444 . The control algorithm predicts the expected thermal plate 260 temperature at a fixed time in the future (typically 5 secs) on the basis of the history of current through the peltier device 440 , thermal plate temperature 260 and heat sink 444 temperature. From this, the required (assumed constant) current to achieve the desired current is calculated. After ensuring that the calculated current will fall within the range for the power converter and peltier device 440 and that rate-of-change of temperature will not result in thermal shock damage to the peltier device 440 , the calculated current is applied to peltier device 440 by control of the power converter 470 and reversing switch 472 . This current is recalculated at a fixed period of around 1 second. Once the thermal plate 260 temperature is close to the target, fine temperature control is done by trimming the assumed thermal conductivity of the peltier device 440 , according to the temperature error.
[0051] Three types of memory are built into the thermal module processor system different contents:
Flash 482: A boot-loader program; RAM 484: Operating program and variables; EEPROM 486: Characteristics of a particular thermal management module 104
[0052] (serial number, temperature calibration factors). The boot loader program runs at power-on, its purpose is to accept new program code that is sent to all of the controllers 474 in the thermal modules 104 by the embedded PC control module 122 . This is a convenience since the operating code for the thermal modules 104 is stored in the embedded PC control module 122 , allowing easy upgrade of instruments in the field.
[0053] The six thermal management modules 104 sit on an internal network designed to pass information between the embedded PC control module 122 and the addressed thermal control module 104 (control processor 474 ).
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An apparatus for automatically hybridizing nucleic acid samples is disclosed. The apparatus includes a fluid control module and a temperature control module for precisely controlling fluid contacting and temperature of a plurality of DNA samples. The DNA samples are typically arrayed on solid substrates (glass microscope slides), and the disclosed apparatus can process up to twelve slides at one time on a master unit; satellite units can be added to increase the number of slides. All slides can be processed in parallel, or may be addressed individually to undergo different hybridization protocols. Thermal control is typically by slide pairs, such that each slide pair undergoes the same temperature profile. Processes are carried out under software control by an embedded PC (personal computer). User input is by touchscreen or floppy disk drive.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of application Ser. No. 09/995,809 filed Nov. 29, 2001.
[0002] This application claims the priority of German Application No. 100 59 262.7 filed Nov. 29, 2000, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0003] This invention relates to a method and an apparatus for determining a point of regulation for drafting units integrated in a fiber processing machine and is of the type in which the change of a quality-characterizing magnitude of the fiber material (for example, its thickness, mass or the like) is measured. The measurement signals are applied to a control device for varying the draft.
[0004] The invention is particularly concerned with an evening of textile slivers in drafting units associated with fiber processing machines. In preparation machines frequently a drafting unit is provided in the feed chutes. Likewise, in carding machines or roller cards regulated drafting units may be disposed in the feed chute or in the inlet zone of the machine. At the input of carding machines or roller card units sensors are provided which detect the thickness of the fiber batt and, as a function of the sensed magnitudes, control the rpm of the feed rolls for evening the fiber batt. At the outlet of the carding machines or roller card units sensors are provided for monitoring the sliver mass. The signals corresponding to the sliver mass fluctuation may be used to regulate the feed roll at the input of the machine or to control a drafting unit at the outlet of the machine.
[0005] In the regulated draw frames of spinning systems such as cotton spinning, yarn spinning, half yarn spinning, woolen spinning and bast fiber spinning systems, the slivers are caused to converge and are subsequently drafted. During the drafting in the drafting unit, sliver mass fluctuations are compensated for by regulation. In regulated draw frames as well as in carding machines and roller card units, both the control and the regulating principles find application. According to the control principle the sensor for the sliver mass fluctuations is situated upstream of the drafting unit. In the regulating principle, such sensor is positioned downstream of the drafting unit. In either case the signal representing the sliver mass fluctuation is utilized for changing the draft in the principal drafting field.
[0006] The detection of mass fluctuations, particularly thickness fluctuations, is effected as a rule with a mechanical scanning system upstream of the input of the draw unit (drafting unit). The measuring signal is stored and after a predetermined delay which corresponds to a certain displacement of the processed material, the regulation is initiated which compensates for the mass fluctuations. Such a point of initiation in time is the point of regulation. The compensation of the mass fluctuations in the principal drafting field is effected by changing the rpm of the regulating motor while at the same time the rpm of the drive motor for the output rolls of the principal drafting field is maintained constant.
[0007] Known methods and devices concern the exact preservation of the point of regulation and its correction, while taking into account internal machine effects and/or environmental effects, as disclosed, for example, in German patent documents 45 15 682 and 43 06 343. Further proposals in the prior art concern the effect of the starting and stopping of the regulated draw frames or the inertia behavior of the scanning members and structural groups for driving the rolls of the draw frame. According to European Published Patent Application 806 596, to which corresponds U.S. Pat. No. 5,771,542, setting values for the point of regulation and/or the amplification are determined. In such a system the point of regulation in a test or setting process prior to operation of a draw frame or a carding machine is determined and maintained during operation. The proposals of the prior art are based substantially on maintaining constant the point of regulation during operation. Changes occur only during the preliminary setting steps performed for the machine.
[0008] Melliand Textilberichte (Melliand Textile Bulletins), in Volume 79 (1998), pages 403, 404, describe that the behavior of fiber motion in the drafting fields is substantially dependent from the delivery speed. As a rule, at low speeds a uniform fiber motion occurs. At higher speeds, however, a sudden acceleration is experienced in the middle of the drafting field. It has been observed that the speed conditions of the fiber are less constant as viewed along the width of the material and also as a function of time. In addition, in one part of the fibers, accelerations and decelerations alternate in a more pronounced manner, that is, the fiber acceleration is not continuous. These effects may be traced back to an increase of the alternation of sliding/adhering properties and sliver thickness fluctuations. These fluctuations of the fiber motion render the slivers non-uniform.
SUMMARY OF THE INVENTION
[0009] It is an object of the invention to provide an improved method and apparatus of the above-outlined type from which the discussed disadvantages are eliminated and which, in particular, provides for a significant improvement in the degree of efficiency of regulation and the uniformity of the drafted sliver and, in particular, the regulating process is additionally optimized.
[0010] These objects and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the apparatus for determining a point of regulation in a drafting unit includes a sensor for generating signals as a function of change in a quality-representing magnitude of the fiber material running through the drafting unit; a control device receiving the signals for varying a draft of the fiber material by the drafting unit; and an arrangement for continuously determining, during operation, optimal points of regulation based on the signals.
[0011] Thus, according to the invention, the point of regulation is varied during the production process as a function of mass fluctuations to thus significantly improve the efficiency of regulation. According to the invention, first data concerning the mass fluctuation are stored and subsequently, based on the stored values, the optimal points of regulation are determined with the aid of a computing algorithm or by a transfer function. Dependent on the results, to each sliver thickness a point of regulation is assigned. In this manner the point of regulation is variable during operation of the sliver drawing unit.
[0012] A microprocessor is expediently used for computing the optimal point of regulation. The detected mass fluctuations which are essential for changing the rpm of the regulating motor and the computed points of regulation associated therewith are stored and are accessed upon reaching the respective point of reaction. The nominal rpm is applied to the regulating motor preferably via a frequency converter. The position of the regulation and thus the extent of displacement from the measuring location associated therewith up to the point of reaction is variable independently from the fiber material.
[0013] The particular properties of the fiber materials, for example, the static and dynamic friction behavior as well as type of material may be added into the computing algorithm or the transfer function.
[0014] It may be advantageous from the point of view of drafting theory to perform the sliver mass regulation as late as possible in the spinning process. Thus, German patent document 34 25 345 proposes to provide a regulating device in the opening units of open-end spinning machines. Such a solution, however, has not yet been used in the mass producing practice because of cost considerations. The invention may be advantageously utilized in opening units of open-end spinning machines. Here too, first the data on sliver mass fluctuations are stored and subsequently, based on the stored values, the optimal points of regulation are determined with the aid of a computing algorithm or a transfer function so that, according to the results thereof, to each measurement of sliver a point of regulation is assigned. In this manner, the point of regulation is variable during the operation of the regulated draw unit.
[0015] The invention, in addition to drafting units of preparation machines, draw frames and open-end spinning machines, may be utilized in draw units of other types of spinning machines, such as flyers, ring spinning or air spinning machines. Such draw units have been heretofore not equipped with regulating devices on a basis of mass manufacture because of cost considerations. From the point of view of drafting technology, the use of a regulating device according to the invention with continuous computation of the point of regulation is a sensible solution.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a schematic side elevational view of the fiber batt intake device at the inlet of a carding machine or a roller card unit, incorporating the invention for performing a short-term regulation.
[0017] [0017]FIG. 2 is a schematic side elevational view of a carding machine incorporating the invention for a long-term regulation.
[0018] [0018]FIG. 3 is a schematic side elevational view of a draw frame incorporating the invention.
[0019] [0019]FIG. 4 is a schematic side elevational view of the opening unit of an open-end spinning machine, incorporating the invention.
[0020] [0020]FIG. 5 is a schematic side elevational view of the draw unit of a ring-spinning machine incorporating the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] [0021]FIG. 1 illustrates the feeding device of a roller card unit or a carding machine which may be a high-performance DK 903 model manufactured by Trรผttzschler GmbH & Co. KG, Mรถnchengladbach, Germany. The fiber batt 6 is advanced to a licker-in 5 by a feed roller 4 in cooperation with a feed table 42 . The processing direction is designated with the arrow A. The mass of the sliver 6 entering the nip defined between the feed roller 4 and the feed table 42 is detected by a sensor 1 whose signals are applied to a regulator 2 . The latter, in turn, applies its signals to a drive 3 for rotating the feed roller 4 . The rpm of the feed roller 4 is varied by the motor 3 as a function of the signals applied thereto by the regulator 2 .
[0022] [0022]FIG. 2 shows a carding machine in which the licker-in 5 transfers fiber material to the main carding cylinder 8 . Thereafter, the fiber material is taken over by a doffer 9 cooperating with a stripping roll 10 . Subsequently, the material passes between crushing rolls 11 , 12 . A sensor 7 positioned downstream of the crushing rolls 11 , 12 monitors the mass of sliver outputted by the carding machine. The sliver, after passing the sensor 7 travels through a non-illustrated drafting unit. The signal from the sensor 7 , representing the sliver mass, is utilized for the long-term regulation by virtue of the fact that the signal representing the sliver mass is applied to the feed roll drive motor 3 via the regulator 2 . In both regulating devices according to FIGS. 1 and 2 the point of regulation is changed in a continuous manner.
[0023] [0023]FIG. 3 illustrates the drafting unit of a cotton draw frame, such as, for example, a high-performance HS model manufactured by Trรผtzschler GmbH & Co. KG. A plurality of slivers 13 runs side-by-side through a sensing device 14 a, 14 b which continuously registers the sliver thickness and applies the signals derived therefrom to a control device 15 . Thereafter, the doubled slivers run through a draw unit 16 which, as a rule, is composed of three roll pairs between which the drafting proper takes place. The draw unit is formed of a preliminary drafting zone defined between the roll pairs 23 a, 23 b and 24 a, 24 a and a principal drafting zone defined between the rolls pairs 24 a, 24 b and the roll assembly 25 a, 25 b, 26 . The drafted sliver is, by means of a sliver trumpet 17 , combined into a single drafted sliver and passes through a second sliver sensing organ 18 a, 18 b and a sliver guiding unit before being deposited in a coiler can (neither shown). The last (output) rolls 25 a, 25 b of the drafting unit 16 are driven at a constant velocity by an electric motor 19 . The roll pairs 23 a, 23 b as well as 24 a, 24 b which are situated upstream of the rolls 25 a, 25 b are driven by an rpm-variable motor 20 . Based on the different circumferential velocities of the roll pairs, the slivers are drafted, and the extent of draft is a function of the velocity relationships between the roll pairs. The rpm changes of the motor 20 thus result in a change of the extent of draft. Such a change is controlled by the control device 22 with the aid of a setting signal which is correlated with the mass fluctuations of the slivers in the input zone of the draw unit.
[0024] [0024]FIG. 4 shows a regulating device associated with the opening unit of an open-end spinning machine and includes a feed roll 27 , a feed table 44 and an opening roll 28 . The fiber material entering the device is designated at 29 . As a first step, the sliver mass fluctuations are detected by a measuring member 30 . Subsequently, based on the detected values, the optimal points of regulation are determined by a regulator 31 with the aid of a computing algorithm or a transfer function, so that, as a result, with each sliver measurement a point of regulation is associated. The point of regulation is thus variable during operation of the regulated draw unit.
[0025] In FIG. 5 the device according to the invention is associated with the draw unit of a ring-spinning machine. The sensor 38 , detecting mass fluctuations of the sliver 37 , applies its signals to a regulator 39 which, in turn, controls a motor 40 driving the two roll pairs 33 a, 33 b and 34 a, 34 b. The motor 41 drives the output roll pair 35 a, 35 b with a constant speed. On the basis of the detected values the optimal points of regulation are determined with the aid of a computing algorithm or a transfer function so that as a result, with each measurement of the sliver mass a point of regulation is associated. In this manner, the point of regulation of the draw unit is variable during operation.
[0026] It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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An apparatus for determining a point of regulation in a drafting unit includes a sensor for generating signals as a function of change in a quality-representing magnitude of the fiber material running through the drafting unit; a control device receiving the signals for varying a draft of the fiber material by the drafting unit; and an arrangement for continuously determining, during operation, optimal points of regulation based on the signals.
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BACKGROUND AND SUMMARY OF THE INVENTION
One of the principal concerns of the purchaser of beef, and particularly those who purchase the higher grades of beef is the matter of tenderness as well as good taste. Both qualities are difficult of objective measurement.
Up until the present, the customary way of ascertaining tenderness was by a visual examination of the carcass to see how much fat was dispersed through the muscle -- principally the longissimus muscle from which the higher quality steaks were cut. However, this method is not accurate, and while not being completely invalid, is still of doubtful accuracy.
By our new method, and use of our new apparatus, we provide an objective and highly accurate measurement of the tenderness of the beef in any carcass.
FIGURES
FIG. 1 is a pictorial view of the core gauging template and removing tool of my invention,
FIG. 2 is a side elevational view of the template alone,
FIG. 3 is a pictorial view of the cooking device used in our system, and
FIG. 4 is a detailed view to an enlarged scale of the core holders on the cooking device.
DESCRIPTION
Briefly, our invention comprises a method of testing the tenderness of beef in a carcass by removing a core of the meat from a controlled part of the carcass, cooking the core and then measuring the force required to shear the core. It also includes the template and coring means for taking the core from the carcass, and the device for cooking the core.
More specifically, and referring to the drawings, we provide a template consisting of a piece of stainless steel having a longer leg 10 adapted to lie flat on the carcass and a shorter leg 11 substantially perpendicular to the longer leg. The shorter leg is adapted to be placed flat against the cut edge of the carcass at the 12th rib which is the location now used by examiners in evaluating the carcass. A tubular guide 12 is mounted on the longer leg 10. The opening through center of the guide tube is extended by forming a hole through that leg so that there is a continuous hole through the template.
A coring tool 13 having a sharpened lower edge 14 is slidably movable through the guide 12. In this way, the location and angular position of the coring tool is strictly controlled relative to the cut edge of the beef quarter. The angular position is important because the core must be taken parallel to the muscle fiber alignment. Normally this will be a 65ยฐ angle.
On the shorter leg 11, we provide a knife guide consisting of a pair of rails 15 spaced apart about the thickness of a knife blade and bracketing a slot 16 in the shorter leg. Thus, a knife can be uniformly guided into the meat to cut the lower end of the core loose from the surrounding meat and allow it to be withdrawn.
The method of determining the tenderness of the core depends on taking of the core uniformly from all carcasses, and by use of the template, this uniformity can be accomplished. After removal of the core from the carcass, it is placed in a bath of melted fat at a controlled temperature for a controlled time. We have found that a temperature of 250ยฐ F. for 23/4 minutes gives the best results. The goal is to provide a uniform and medium degree of doneness without abnormal protein coagulation or surface crustiness which would interfere with the shearing.
A device for cooking the cores is illustrated in FIGS. 3 and 4. In this device, a vat or container 18 is provided to hold the heated fat. Heating coils 19 at each end of the container serve to provide a controlled amount of heat to hold the fat at a pre-set temperature. Thermostatic controls 20 are provided to be sensitive to the temperature and to control the amount of heat provided.
A wheel 21 is rotatably mounted so that it will turn into and out of the fat. Thus, it can carry a series of cores of meat through the heated fat in the container 18. The wheel is mounted on an axle 22, which in turn is driven by a chain drive 23 from a motor mounted in a housing 24 on the container. The motor should be one capable of being controlled to a substantially constant speed, and will probably need to be geared down to provide proper speed to turn the wheel through the fat at a speed in which the core will be properly cooked in one pass.
Each core 26 is held at the periphery of the wheel 20 by pointed fingers on which the core can be impaled and from which it can easily be removed. It will be seen that by providing a fixed temperature of the fat and a fixed speed of the wheel -- and therefore a fixed time during which the core is cooked in the fat -- we can provide a closely controlled set of parameters in which the variable is the character or quality of meat in the core.
After cooking, the core is sheared by a device, well known in the art as a Warner-Bratzler shearing device. By using this device, we can determine the force required to shear the cooked core and hence the tenderness of the core. We prefer to shear the core twice to provide an average reading so that some unusual circumstance in a part of core does not provide a false reading.
We have discovered by several tests that there is a very high correlation between our shear tenderness results and the opinion of human taste panel evaluation of tenderness -- much higher than the correlation between expert graders and the opinion of similar taste panels. Therefore, we are convinced that by controlling the location on the carcass from which the core is removed and the conditions under which it is prepared and sheared, we have provided a valid, objective method of testing the tenderness of a beef carcass.
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A template device adapted to take a core of meat from a carefully controlled portion of a meat carcass including a template adapted to control the location and direction of the coring, and a coring tool adapted to be guided by the template to cut the core from the carcass.
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BACKGROUND OF THE INVENTION
The present invention is directed to signal amplifiers used with a sensor such as a read head in an information storage device, and especially to such signal amplifiers for which some control is available regarding certain operating parameters associated with the amplifier.
There are many important goals in designing and operating an amplifier for use with a sensor, two such goals are: low band pass corner frequency and low noise. Sensors such as magneto-resistive sensing elements require a direct current (DC) bias applied across them to operate correctly. The presence of such a DC bias may cause problems if the DC signal is passed on to amplifying elements. A low band pass corner frequency permits sensing of lower frequency signals while still rejecting DC signals and therefore contributes to a truer sensing of signals indicated by the sensor. Lower noise is desirable to reduce noise attributable to the sensor's read back signal.
Prior art signal amplifiers, especially signal amplifiers for use with a read head in an information storage device, have resulted in a compromise in noise performance when a very low band pass corner is needed.
There is a need for a signal amplifier apparatus that accommodates design for both low band pass corner frequency and lower noise.
SUMMARY OF THE INVENTION
An apparatus for use with a sensor includes first and second signal treating circuit segments coupled with the sensor for presenting a substantially balanced differential signaling representation of output signals from the sensor. Each respective signal treating circuit segment comprises a plurality of circuit elements having different electrical symmetries coupled in parallel and establishing a plurality of parallel signal paths having asymmetric signal handling characteristics. A feedback circuit is coupled with the first and second signal treating circuit segments and provides feedback signals to the circuit elements in each of the first and second signal treating circuit segments. The feedback signals effect substantially balanced signal handling among circuit elements having similar electrical symmetries.
It is, therefore, an object of the present invention to provide a signal amplifier apparatus that accommodates design for both low band pass corner frequency and lower noise.
Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphic representation of an amplifier output transfer function.
FIG. 2 is an electrical schematic illustration of a first example of a prior art differential amplifier for use with a read head.
FIG. 3 is an electrical schematic illustration of a second example of a prior art differential amplifier for use with a read head.
FIG. 4 is an electrical schematic illustration of a third example of a prior art differential amplifier for use with a read head.
FIG. 5 is an electrical schematic illustration of a fourth example of a prior art differential amplifier for use with a read head.
FIG. 6 is an electrical schematic illustration of the differential amplifier of the present invention.
FIG. 7 is an electrical schematic illustration of the preferred embodiment of the differential amplifier of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a graphic representation of an amplifier output transfer function. In FIG. 1 , a graphic plot 100 includes a frequency response curve 101 is plotted against a vertical axis 102 representing signal strength in decibels (dB) and plotted against a horizontal axis 104 representing frequency in a parameter appropriate for the circuit or device involved, such as megaHertz (MHz; not indicated in FIG. 1 ). Curve 101 varies up to a maximum signal strength of max dB. Curve 101 achieves a signal of MAX โ3 dB at a frequency f LF . The frequency at a point 106 at which a frequency response curve (e.g., curve 101 ) is at a โ3 dB signal level at the left end of the frequency response is commonly referred to as the low corner frequency of the frequency response curve. Frequency f LF is the low corner frequency of frequency response curve 101 . In designing an amplifier circuit for a sensor, such as a read head, it is advantageous to establish low corner frequency f LF as low as possible to permit the amplifier to respond to as low a frequency signal from the sensor as can be achieved without passing DC signals.
FIG. 2 is an electrical schematic illustration of a first example of a prior art differential amplifier for use with a read head. In FIG. 2 , a read amplifier circuit 10 (sometimes also referred to as a read front-end) is attached to a magneto-resistive element 12 via connection leads 14 , 16 connected in parallel. A capacitor 18 is coupled with connection lead 14 . A capacitor 20 is coupled with connection lead 16 . Capacitors 18 , 20 block low frequency signals that appear on connection leads 14 , 16 .
Metal-oxide silicon (MOS) transistor 30 has a source 32 , a drain 34 and a gate 36 . Metal-oxide silicon (MOS) transistor 40 has a source 42 , a drain 44 and a gate 46 . Sources 32 , 42 are coupled in common and with a ground locus 28 via a current source 50 . Gate 36 is coupled with connection lead 14 via capacitor 18 and gate 46 is connected with connection lead 16 via capacitor 20 . A bias reference source 22 is connected via resistors 24 , 26 to establish a predetermined bias potential at gates 36 , 46 . Drain 34 is coupled with a supply voltage V CC at a supply voltage locus 52 via a resistor 54 . Drain 44 is coupled with supply voltage V CC at supply voltage locus 52 via a resistor 56 . Output signals are taken from drains 34 , 44 and presented at output loci 60 , 62 .
Amplifier circuit 10 advantageously permits setting low corner frequency f LF ( FIG. 1 ) by resistors 24 , 26 and capacitors 18 , 20 according to the relationship:
f
LF
โผ
1
2
โข
โข
ฯ
โข
โข
R
โข
โข
C
[
1
]
whereหindicates proportional to;
R is the resistance value of resistors 24 , 26 ; and C is the capacitance of capacitors 18 , 20 .
A further advantage of amplifier circuit 10 is that setting of low corner frequency f LF is independent of the currents or physical dimensions of MOS transistors 30 , 40 .
A disadvantage of amplifier circuit 10 is that it requires that MOS transistors 30 , 40 be large in order to limit noise at the input of amplifier circuit 10 โe.g., at gates 36 , 46 , and a large MOS transistor 30 , 40 will provide large input capacitance so that gates 36 , 46 establish a capacitive divider that will effect significant attenuation on all frequency signals. Another disadvantage of amplifier circuit 10 is that a low noise design of amplifier circuit 10 requires that a large bias current be provided by current source 50 that contrasts the desire for low power.
FIG. 3 is an electrical schematic illustration of a second example of a prior art differential amplifier for use with a read head. In FIG. 3 , a read amplifier circuit 110 (sometimes also referred to as a read front-end) is attached to a magneto-resistive element 112 via connection leads 114 , 116 connected in parallel. A capacitor 118 is coupled with connection lead 114 . A capacitor 120 is coupled with connection lead 116 . Capacitors 118 , 120 block low frequency signals that appear on connection leads 114 , 116 .
Bipolar transistor 130 has an emitter 132 , a collector 134 and a base 136 . Bipolar transistor 140 has an emitter 142 , a collector 144 and a base 146 . Emitters 132 , 142 are coupled in common and with a ground locus 128 via a current source 150 . Base 136 is coupled with connection lead 114 and base 146 is connected with connection lead 116 . A bias reference source 122 is connected via resistors 124 , 126 to establish a predetermined bias potential at bases 136 , 146 . Collector 134 is coupled with a supply voltage V CC at a supply voltage locus 152 via a resistor 154 . Collector 144 is coupled with supply voltage V CC at supply voltage locus 152 via a resistor 156 . Output signals are taken from collectors 134 , 144 and presented at output loci 160 , 162 .
Amplifier circuit 110 advantageously requires less bias current than amplifier 10 ( FIG. 2 ) because bipolar transistors 130 , 140 usually require less bias current than MOS transistors 30 , 40 ( FIG. 2 ) for the same noise performance. Further, bipolar transistors 130 , 140 are physically smaller (i.e., require less die space) than MOS transistors 30 , 40 ( FIG. 2 ) for a given noise level.
A disadvantage of amplifier 110 vis-ร -vis amplifier 10 is that amplifier 110 has a low corner frequency f LF and noise level that are both functions of the bipolar device collector current I C and are in opposing relationship. In order to achieve low noise, collector current IC varies according to the relationship:
V
NOISE
=
4
โข
โข
k
โข
โข
T
โก
(
r
b
+
V
T
2
โข
โข
I
C
)
[
2
]
Where V NOISE is voltage level of noise present;
k is Boltzmann's constant; T is temperature; r b is related to transistor emitter geometry; V T is transconductance voltage of a bipolar transistor; and I C is collector current of a bipolar transistor.
Requiring high I C conflicts with the need for high r ฯ to yield a low corner frequency f LF according to the relationships:
r
ฯ
=
ฮฒ
ยท
V
T
I
C
[
3
]
Where ฮฒ is current gain of a bipolar transistor;
V T is transconductance voltage of a bipolar transistor; and I C is collector current of a bipolar transistor.
f
LF
โผ
1
2
โข
โข
ฯ
โข
โข
C
โข
โข
r
ฯ
[
4
]
whereหindicates proportional to;
r ฯ is calculated according to Expression [3]; and C is the capacitance of capacitors 118 , 120 .
FIG. 4 is an electrical schematic illustration of a third example of a prior art differential amplifier for use with a read head. In FIG. 4 , a read amplifier circuit 210 (sometimes also referred to as a read front-end) is attached to a magneto-resistive element 212 via connection leads 214 , 216 connected in parallel. A capacitor 218 is coupled with connection lead 214 . A capacitor 219 is coupled with connection lead 216 . Capacitors 218 , 219 block low frequency signals that appear on connection leads 214 , 216 .
A bipolar transistor 220 has an emitter 222 , a collector 224 and a base 226 . A bipolar transistor 230 has an emitter 232 , a collector 234 and a base 236 . A bipolar transistor 240 has an emitter 242 , a collector 244 and a base 246 . A bipolar transistor 250 has an emitter 252 , a collector 254 and a base 256 . Emitters 222 , 232 are coupled in common and with a ground locus 213 via a current source 211 . Emitters 242 , 252 are coupled in common and with a ground locus 217 via a current source 215 . Base 226 is coupled with connection lead 214 . Base 246 is connected with connection lead 214 via capacitor 218 . Base 256 is coupled with connection lead 216 . Base 236 is connected with connection lead 216 via capacitor 219 . Collectors 224 , 244 are coupled in common and are coupled with a supply voltage V CC at a supply voltage locus 270 via a resistor 274 . Collectors 234 , 254 are coupled in common and are coupled with supply voltage V CC at supply voltage locus 270 via a resistor 272 . Base 236 is connected with a reference voltage V REF1 at a reference voltage locus 263 via a resistor 260 . Base 246 is connected with reference voltage V REF2 at reference voltage locus 264 via a resistor 262 . Output signals are taken from collectors 224 , 244 connected in common and taken from collectors 234 , 254 connected in common and presented at output loci 280 , 282 .
Amplifier circuit 210 is improved over amplifier circuit 110 ( FIG. 3 ) in that cross-coupling of capacitors 218 , 219 results in low corner frequency f LF (for a given capacitor size) being determined by the relationship:
f
LF
โผ
1
2
โข
โข
ฯ
โข
โข
C
โข
โข
(
4
โข
r
ฯ
)
[
5
]
Capacitance (C) of capacitors 218 , 219 in amplifier circuit 210 {expression [5]) may be significantly smallerโon the order of one-fourthโthan capacitors 118 , 120 ( FIG. 3 ; expression [3]) to yield the same low corner frequency f LF . Lower valued capacitors means smaller die size, which is advantageous. Moreover, smaller capacitors 218 , 219 means that fewer parasitics are present so that better high frequency performance is experienced having better bandwidth and lower high frequency noise in amplifier circuit 210 than are experienced in amplifier circuit 110 ( FIG. 3 ).
However, amplifier circuit 210 still has the problem of bipolar transistor noise operating counter to improving low corner frequency f LF , as discussed in connection with amplifier circuit 110 ( FIG. 3 ) and expressions [2], [3] and [4] above.
FIG. 5 is an electrical schematic illustration of a fourth example of a prior art differential amplifier for use with a read head. In FIG. 5 , a read amplifier circuit 310 (sometimes also referred to as a read front-end) is attached to a magneto-resistive element 312 via connection leads 314 , 316 connected in parallel. A capacitor 318 is coupled with connection lead 314 . A capacitor 319 is coupled with connection lead 316 . Capacitors 318 , 319 block low frequency signals that appear on connection leads 314 , 316 .
A metal-oxide silicon (MOS) transistor 320 has a source 322 , a drain 324 and a gate 326 . A MOS transistor 330 has a source 332 , a drain 334 and a gate 336 . A MOS transistor 340 has a source 342 , a drain 344 and a gate 346 . A MOS transistor 350 has a source 352 , a drain 354 and a gate 356 . Sources 322 , 332 are coupled in common and with a ground locus 313 via a current source 311 . Sources 342 , 352 are coupled in common and with a ground locus 317 via a current source 315 . Gate 326 is coupled with connection lead 314 . Gate 346 is connected with connection lead 314 via capacitor 318 . Gate 356 is coupled with connection lead 316 . Gate 336 is connected with connection lead 316 via capacitor 319 . Drains 324 , 344 are coupled in common and are coupled with a supply voltage V CC at a supply voltage locus 370 via a resistor 374 . Drains 334 , 354 are coupled in common and are coupled with supply voltage V CC at supply voltage locus 370 via a resistor 372 . Gate 336 is connected with a reference voltage V REF1 at a reference voltage locus 363 via a resistor 360 . Gate 346 is connected with reference voltage V REF2 at reference voltage locus 364 via a resistor 362 . Output signals are taken from drains 324 , 344 connected in common and taken from drains 334 , 354 connected in common and presented at output loci 380 , 382 .
Amplifier circuit 310 enjoys advantages similar to advantages experienced by amplifier circuit 210 ( FIG. 4 ) because of the cross-coupling of capacitors 318 , 319 . That is, capacitors 318 , 319 in amplifier circuit 310 may be significantly smallerโon the order of one-fourthโthan capacitors 118 , 120 ( FIG. 3 ) to yield the same low corner frequency f LF . Lower valued capacitors means smaller die size. Moreover, smaller capacitors 318 , 319 means that fewer parasitics present so that better high frequency performance having better bandwidth and lower high frequency noise is experienced in amplifier circuit 310 as compared with amplifier circuit 110 ( FIG. 3 ). Amplifier circuit 310 enjoys further advantages similar to amplifier circuit 10 ( FIG. 2 ) in that setting of low corner frequency f LF is independent of the currents or physical dimensions of MOS transistors 320 , 330 , 340 , 350 . However, noise characteristics of amplifier circuit 310 are not as good as noise characteristics of amplifier circuit 110 ( FIG. 3 ) or amplifier circuit 210 ( FIG. 4 ).
The present invention combines advantages of bipolar and MOS transistor implementations of amplifier circuits. This design proved difficult to achieve because balanced performance by bipolar and MOS transistors must be achieved. The preferred embodiment of the amplifier circuit of the present invention employs asymmetric amplifier structures in each of two parallel circuit segments that operate symmetrically and cooperate to effect balanced signal amplification overall.
FIG. 6 is an electrical schematic illustration of the differential amplifier of the present invention. In FIG. 6 , a read amplifier circuit 410 (sometimes also referred to as a read front-end) is attached to a magneto-resistive element 412 via connection leads 414 , 416 connected in parallel. A capacitor 418 is coupled with connection lead 414 . A capacitor 419 is coupled with connection lead 416 . Capacitors 418 , 419 block low frequency signals that appear on connection leads 414 , 416 .
A bipolar transistor 420 has an emitter 422 , a collector 424 and a base 426 . A MOS transistor 430 has a source 432 , a drain 434 and a gate 436 . A bipolar transistor 450 has an emitter 452 , a collector 454 and a base 456 . A MOS transistor 440 has a source 442 , a drain 444 and a gate 446 . Emitter 422 and source 432 are coupled in common and with a ground locus 413 via a current source 411 . Emitter 452 and source 442 are coupled in common and with a ground locus 417 via a current source 415 . Base 426 is coupled with connection lead 414 . Gate 446 is connected with connection lead 414 via capacitor 418 . Base 456 is coupled with connection lead 416 . Gate 436 is connected with connection lead 416 via capacitor 419 . Collectors 424 , 454 , drains 434 , 444 and gates 436 , 446 are coupled with a transconductance feedback and signal combining unit 460 (hereinafter referred to as feedback/combining unit 460 ). Feedback/combining unit 460 is coupled with a supply voltage V CC at a supply voltage locus 462 and coupled with output loci 470 , 472 at which output signals are presented.
Feedback/combining unit provides feedback to gates 436 , 446 to ensure balanced performance for each MOS/bipolar transistor pair 430 / 420 and 440 / 450 . Amplifier circuit 410 has advantages from using MOS transistors 430 , 440 in that low corner frequency f LF is set substantially independent of the currents or physical dimensions of MOS transistors 430 , 440 . Amplifier circuit 410 has advantages from using bipolar transistors 420 , 450 in that noise is partly determined by expressions [2] and [3], but requiring high I C does not conflict achieving a low corner frequency f LF . This is so because low corner frequency f LF is substantially set by transconductance feedback from feedback/combining unit 460 so the need for high r ฯ (which is counter to the need for high I C to reduce noise) for a bipolar transistor to yield a low corner frequency f LF is not a consideration.
FIG. 7 is an electrical schematic illustration of the preferred embodiment of the differential amplifier of the present invention. In FIG. 7 , a read amplifier circuit 510 (sometimes also referred to as a read front-end) is attached to a magneto-resistive element 512 via connection leads 514 , 516 connected in parallel. A capacitor 518 is coupled with connection lead 514 . A capacitor 519 is coupled with connection lead 516 . Capacitors 518 , 519 block low frequency signals that appear on connection leads 514 , 516 .
A bipolar transistor 520 has an emitter 522 , a collector 524 and a base 526 . A MOS transistor 530 has a source 532 , a drain 534 and a gate 536 . A bipolar transistor 550 has an emitter 552 , a collector 554 and a base 556 . A MOS transistor 540 has a source 542 , a drain 544 and a gate 546 . Emitter 522 and source 432 are coupled in common and with a ground locus 517 via a current source 511 . Emitter 552 and source 542 are coupled in common and with a ground locus 517 via a current source 515 . Base 526 is coupled with connection lead 514 . Gate 546 is connected with connection lead 514 via capacitor 518 . Base 556 is coupled with connection lead 516 . Gate 536 is connected with connection lead 516 via capacitor 519 . Collectors 524 , 554 , drains 534 , 544 and gates 536 , 546 are coupled with a transconductance feedback and signal combining unit 560 (hereinafter referred to as feedback/combining unit 560 ). Feedback/combining unit 560 includes a transconductance unit 562 connected with collectors 524 , 554 , connected with gates 536 , 546 and connected with a reference voltage V REF at a reference voltage locus 564 .
Transconductance unit 562 provides an error current to gates 536 , 546 that is related with voltages received at collectors 524 , 554 . Transconductance unit 562 provides the required feedback to adjust collector currents at collectors 524 , 554 and drain currents at drains 534 , 544 to cause bipolar transistors 520 , 550 to operate substantially symmetrically and to cause MOS transistors 530 , 540 to operate substantially symmetrically.
Collector 524 is coupled with a supply voltage V CC at a supply voltage locus 566 via a resistor 570 . Drain 534 is coupled with supply voltage V CC at supply voltage locus 566 via a resistor 572 . Drain 544 is coupled with supply voltage V CC at supply voltage locus 566 via a resistor 574 . Collector 554 is coupled with supply voltage V CC at supply voltage locus 566 via a resistor 576 .
An amplifier 580 is connected to receive output signals from between resistor 572 and drain 534 , and is also connected to receive output signals from between resistor 574 and drain 544 . An amplifier 582 is connected to receive output signals from between resistor 570 and collector 524 , and is also connected to receive output signals from between resistor 576 and collector 554 . Thus, each of amplifiers 580 , 582 receives inputs from only one type of transistor-amplifier 580 receives inputs from MOS transistors 530 , 540 and amplifier 582 receives inputs from bipolar transistors 520 , 550 . Amplified signals are provided by amplifiers 580 , 582 to a summer 584 . Summer 584 is coupled with output loci 590 , 592 at which output signals are presented.
It is to be understood that, while the detailed drawings and specific examples given describe preferred embodiments of the invention, they are for the purpose of illustration only, that the apparatus and method of the invention are not limited to the precise details and conditions disclosed and that various changes may be made therein without departing from the spirit of the invention which is defined by the following claims.
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An apparatus for use with a sensor includes first and second signal treating circuit segments coupled with the sensor for presenting a substantially balanced differential signaling representation of output signals from the sensor. Each respective signal treating circuit segment comprises a plurality of circuit elements having different electrical symmetries coupled in parallel and establishing a plurality of parallel signal paths having asymmetric signal handling characteristics. A feedback circuit is coupled with the first and second signal treating circuit segments and provides feedback signals to selected circuit elements in each of the first and second signal treating circuit segments. The feedback signals effect substantially balanced signal handling among the selected circuit elements having similar electrical symmetries.
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FIELD OF THE INVENTION
[0001] This invention refers to the skin of an aircraft lifting surface skin and, more in particular, to an stiffening arrangement for those skin panels which can not be stiffened by stringers.
BACKGROUND OF THE INVENTION
[0002] The main structure for aircraft lifting surfaces mainly consists of a leading edge, a torsion box, a trailing edge, a root joint and a wing tip. The torsion box in turn consists of several structural elements: upper and lower skins stiffened by stringers on one side; spars and ribs on the other side. Those stringers, spars and ribs create a grid pattern that subdivides the upper and the lower skins in structural panels limited now by those elements, discretizing that way the bulking loads in the skins. Typically, the structural elements forming the torsion box are manufactured separately and are joined with the aid of complicated tooling to achieve the necessary tolerances, which are given by the aerodynamic, assembly and structural requirements.
[0003] As is well known, weight is a fundamental aspect in the aeronautic industry and therefore there is a current trend to use composite material instead of metallic even for primary structures.
[0004] The composite materials that are most used in the aeronautical industry consist of fibers or fiber bundles embedded in a matrix of thermosetting or thermoplastic resin, in the form of a preimpregnated or โprepregโ material. Its main advantages refer to:
Their high specific strength with respect to metallic materials. It is the strength/weight equation. Their excellent behavior before fatigue loads. The possibilities of structural optimization hidden in the anisotropy of the material and the possibility of combining fibers with different orientations, allowing the design of the elements with different mechanical properties adjusted to the different needs in terms of applied loads.
[0008] The design and manufacture of large composite skins of aircraft lifting surfaces such as the skins of aircrafts wings involves several problems. One of them is the stabilization of those skin panels which are not stiffened with stringers due to interferences with, particularly, spars or ribs. In the prior art, this stabilization is achieved increasing the panel thickness, increasing, thus, the skin weight which is an important drawback for an aeronautical structure.
[0009] This invention is focused on the solution of this problem.
SUMMARY OF THE INVENTION
[0010] One object of the present invention is to provide a mult-rib box-shaped structure of an aircraft lifting surface such as a wing or an horizontal tail plane having skins optimized in weight even in those panels which are not stiffened by span wise stringers due to interferences with another structural elements.
[0011] Another object of the present invention is to provide a mult-rib box-shaped structure of an aircraft lifting surface such as a wing or an horizontal tail plane having skins arranged for reducing buckling risks even in those panels which are not stiffened by span wise stringers due to interferences with another structural elements.
[0012] These and other objects are met by a mult-rib box-shaped aeronautical structure comprising upper and lower skins stiffened by span wise stringers, span wise front and rear spars and chord wise ribs, where at least one panel of any of said skins is non delimited by said ribs and said stringers and comprise an stiffening element arranged as a panel breaker to avoid the need of increasing the panel thickness to withstand the buckling loads.
[0013] In a preferred embodiment the stiffening element is an isolated stiffening element in the panel that need reinforcement to withstand the buckling loads. Hereby it is achieved an arrangement that facilitates its installation in said panels.
[0014] In another preferred embodiment the stiffening element is joined to another structural element, particularly a rib or a stringer ending in an adjacent panel. Hereby it is achieved an arrangement that improves the load distribution in said panels.
[0015] In a preferred embodiment the stiffening element follow a linear trace between the end of the closer stringer and a final point in said panel at a suitable distance of the structural element that delimits said panel instead of an stringer. Hereby it is achieved an optimized division of said panel for weight reduction purposes.
[0016] In a preferred embodiment, the stringers and the stiffening elements have the same transversal shape, preferably a T or a L shape. Hereby it is achieved an arrangement that facilitates the skin manufacturing process.
[0017] Other characteristics and advantages of the present invention will be clear from the following detailed description of embodiments illustrative of its object in relation to the attached figures.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1 a is a perspective view of a known multi-rib torsion box of an aircraft wing and FIG. 1 b is a cross-section view of FIG. 1 a along plane A-A.
[0019] FIG. 2 is an internal plan view of an area of a skin belonging to the torsion box of an aircraft wing according to the prior art.
[0020] FIG. 3 is an internal plan view of an area of a skin belonging to the torsion box of an aircraft wing according to a first embodiment of the present invention.
[0021] FIG. 4 is an internal plan view of an area of a skin belonging to the torsion box of an aircraft wing according to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The invention relates to a multi-rib torsion box structure of composite materials with longitudinal stiffeners, having preferably a T-shaped or a L-shaped cross-section. The composite material can be both carbon fiber and fiberglass with thermosetting or thermoplastic resin. The main field of application is aeronautical lifting surfaces structures, although they can also be applied to other structures with similar features.
[0023] The main structure of an aircraft lifting surface such as a wing consists of a leading edge, a torsion box, a trailing edge, a root joint and a wing tip. A multi-rib torsion box 1 such as the one depicted in FIGS. 1 a and 1 b is structurally based on a span wise front spar 11 and a span wise rear spar 13 (understanding the terms front and rear in relation to the flight direction of the aircraft), a plurality of chord wise ribs 27 , 27 โฒ, 27 โณ, 27 โฒโณ and the upper and lower skins 19 , 21 with a plurality of span wise stringers 25 , 25 โฒ, 25 โณ.
[0024] The main functions of ribs 27 , 27 โฒ, 27 โณ, 27 โฒโณ is to provide torsion rigidity and to limit the skins 19 , 21 and the stringers 25 , 25 โฒ, 25 โณ longitudinally so as to discretize the buckling loads and maintain the shape of the aerodynamic surface.
[0025] The primary function of the skins 19 , 21 is to provide a continuous surface to give support and distribute the aerodynamic loads and, thus, it is structured as a set of panels delimited by said ribs 27 , 27 โฒ, 27 โณ, 27 โฒโณ and said stringers 25 , 25 โฒ, 25 โณ as well as the front spar 11 and the rear spar 13 .
[0026] FIG. 2 shows a common case where the panels 31 , 33 are delimited by the ribs 27 , 27 โฒ, 27 โฒ, the stringer 25 โฒ and the front spar 11 . In this case, the stringer 25 cannot be extended to decrease the size of the panels 31 , 33 because it would interfere with the front spar 11 .
[0027] According to the invention those panels 31 , 33 lacking one stringer are provided with stiffening elements so that their thickness does not need to be increased to avoid buckling. Those stiffening elements act therefore as panel breakers on the skin decreasing the panels size allowing a thickness decrease and a weight reduction.
[0028] In a preferred embodiment, illustrated in FIG. 3 , said stiffening elements 41 are isolated stiffening elements on each panel 31 , 33 that, preferably, follow a lineal trace between the end of the stringer 25 in the adjacent panel 35 and a point close to the rib 27 at a suitable distance of the front spar 11 to comply with the structural requirements. Said stiffening elements 41 โbreakโ the initial panels 31 , 33 into smaller panels 31 โฒ, 31 โณ; 33 โฒ, 33 โณ. Panels 31 โฒ, 33 โฒ are now limited by the stiffening elements 41 , the stringer 25 โฒ and the ribs 27 , 27 โฒ, 27 โณ, having thus a smaller area than the initial panels 31 , 33 allowing a thickness decrease and a weight reduction.
[0029] In another preferred embodiment, said stiffening elements are installed on the skins 19 , 21 joined to another structural element. For instance, as shown in FIG. 4 , the stiffening element 43 that, preferably, follows a lineal trace between the end of the stringer 25 in the adjacent panel 35 and a point close to the rib 27 โฒ at a suitable distance of the front spar 11 to comply with the structural requirements, โbreaksโ the initial panel 33 into the smaller panels 33 โฒ, 33 โณ. Panel 33 โฒ is now limited by the stiffening element 43 , the stringer 25 โฒ and the ribs 27 โฒ, 27 โณ, having thus a smaller area than the initial panel 33 allowing a thickness decrease and a weight reduction. On the other hand, the stiffening element 43 is joined to the rib 27 โฒ and to the stringer 25 ending in the adjacent panel 35 , i.e. a joint arrangement that provides a better load continuity and distribution.
[0030] The stiffening elements 41 , 43 of both embodiments can be installed on the skins 19 , 21 by a co-curing or a co-boding procedure or by a riveted joint. In the second case, the trace shall leave enough space between the stiffening element 43 and the front spar 11 to allow the enlargement of the stiffening element foots needed in the joining areas with stringer 25 and rib 27 โฒ.
[0031] In a preferred embodiment, said stiffening elements 41 , 43 shall have the same transversal section than the stringer 25 , i.e. a T-shaped or a L-shaped transversal section.
[0032] Among others, the advantages of the present invention are the following:
Reduction of the skin thickness and weight of the involved panels in an amount close to the 20%. Reduction of the buckling risk in the skin panels.
[0035] Although the present invention has been fully described in connection with preferred embodiments, it is evident that modifications may be introduced within the scope thereof, not considering this as limited by these embodiments, but by the contents of the following claims.
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A mult-rib box-shaped aeronautical structure comprising upper and lower skins ( 19, 21 ) stiffened by span wise stringers ( 25, 25โฒ, 25 โณ), span wise front and rear spars ( 11, 13 ) and chord wise ribs ( 27, 27โฒ, 27 โณ), where at least one panel ( 31, 33 ) of any of said skins ( 19, 21 ) is non delimited by said ribs ( 27, 27โฒ, 27 โณ) and said stringers ( 25, 25โฒ, 25 โณ) and comprise an stiffening element ( 41, 43 ) arranged as a panel breaker to avoiding the need of increasing the panel thickness to withstand buckling loads.
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BACKGROUND
[0001] 1. Technical Field
[0002] The present invention belongs to the field of crystal forms of compounds, and specifically relates to a crystal form of (6S)-5-methyltetrahydrofolate salt and methods for preparing the same and uses of the same.
[0003] 2. Related Art
[0004] The crystal forms of active pharmaceutical ingredients are closely associated with the biological activity, bioavailability, dissolution, stability, and shelf life thereof. Therefore, during the research and development of new drugs, screening of crystal form is one of the most important tasks. Even if the drug has been on the market for many years, seeking more effective crystal forms of the drug is still the goal intensely pursued by pharmaceutical companies.
[0005] 5-methyltetrahydrofolic acid was first separated from a horse liver in the form of barium salt by Donaldson et al. in 1959 and was named as Prefolic-A, and was synthesized by a chemical method in 1961 (K. O. Donaldson et al., Fed. Proc, (1961), 20, 453).
[0006] The 5-methyltetrahydrofolic acid molecule has two chiral carbon atoms, where the configuration of the chiral carbon atom at the glutamic acid site is certain, while the chiral carbon atom at Site 6 has two configurations R and S, and therefore, 5-methyltetrahydrofolic acid has been used in the form of a diastereomeric mixture. It is reported that, the two isomers have different effects with in vivo enzymes, where the compound with S configuration of the carbon atom at site 6 exhibits good efficacy, while the compound with R configuration of the carbon atom at site 6 almost has no efficacy in comparison.
[0007] The chemical name of (6S)-5-methyltetrahydrofolic acid is (6S)โN[4-[[(2-amino-1,4,5,6,7,8-hexahydro-4-oxo-5-methyl-6-pteridinyl)methyl]amino]benzoyl]-L-glutamic acid, referred to as (6S)-5-MTHF for short hereinafter. The structural formula is shown in Formula I:
[0000]
[0008] (6S)-5-MTHF and salts thereof are very unstable and easily degraded, and especially are highly sensitive to oxygen and moisture (A. L. Fitzhugh, Pteridines 1993, 4(4), 187-191). In the air, (6S)-5-MTHF and salts thereof are easily oxidized into 5-methyldihydrofolic acid and/or folic acid and the like. Therefore, it is difficult to prepare high-purity and high-stability bulk pharmaceutical chemicals or food additives, to meet the quality standards.
[0009] Due to the physical and chemical properties of (6S)-5-MTHF, it is difficult to prepare a stable crystal form of (6S)-5-MTHF by a conventional crystallization process. In the past few decades of production of (6S)-5-MTHF and preparation of formulations thereof, a reducing agent, for example, Vitamin C or 2-mercaptoethanol, is often added to achieve the purpose of anti-oxidation.
[0010] Patent Document U.S. Pat. No. 5,223,500 reports a process for preparing a stable crystal form of (6S)-5-MTHF calcium salt. The process includes the following steps: first, preparing amorphous (6S)-5-MTHF calcium salt, then transferring into boiling water of 100ยฐ C. to form a solution, cooling and standing overnight at room temperature. The collected solid is called to be a stable crystal product. However, relevant crystal parameters are not reported in this patent.
[0011] Patent Document U.S. Pat. No. 6,441,168 discloses a crystal form of (6S)-5-MTHF calcium salt with extremely high stability and a method for preparing the same. (6S)-5-MTHF sodium salt and calcium chloride are subjected to heat treatment in a polar solvent at about 90ยฐ C. to obtain four stable crystal forms of (6S)-5-MTHF calcium salt, which are respectively Form I having 2ฮธ values of 6.3, 13.3, 16.8, and 20.1, Form II having 2ฮธ values of 5.3, 6.9, 5.7, and 21.1, Form III having 2ฮธ values of 6.8, 10.2, 15.4, and 22.5, and Form IV having 2ฮธ values of 6.6, 15.9, 20.2, and 22.5.
[0012] Patent Document WO2008144953 discloses a process for preparing a stable amorphous (6S)-5-MTHF calcium salt, in which a crystal form of (6S)-5-MTHF is used as a raw material, calcium chloride is added for slow crystallization. The whole crystallization process in this patent is very complex, and the crystallization time is 16 to 18 hours, thereby reducing the production capacity in the product procedure.
SUMMARY
[0013] Surprisingly, it has been found now that by using ultrasonic waves to assist crystallization during the formation of a salt, a crystal form of (6S)-5-methyltetrahydrofolate salt with high stability and good chemical and optical purity can be obtained.
[0014] In order to overcome the disadvantages in the prior art, an objective of the present invention is to provide a novel crystal form of (6S)-5-methyltetrahydrofolate salt with good stability, high purity, and good reproducibility.
[0015] Preferably, the present invention sets forth Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.3ยฑ0.2 and 19.2ยฑ0.2.
[0016] Preferably, the present invention sets forth a crystal form of (6S)-5-methyltetrahydrofolate strontium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.5ยฑ0.2 and 22.0ยฑ0.2.
[0017] Preferably, the X-ray diffraction pattern of the Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt has diffraction peaks at the 2ฮธ angles of 3.2ยฑ0.2, 6.3ยฑ0.2, 13.2ยฑ0.2, 14.6ยฑ0.2, 19.2ยฑ0.2, and 32.6ยฑ0.2.
[0018] Preferably, the X-ray diffraction pattern of the crystal form of (6S)-5-methyltetrahydrofolate strontium salt has diffraction peaks at the 2ฮธ angles of 6.5ยฑ0.2, 10.0ยฑ0.2, 13.7ยฑ0.2, 16.8ยฑ0.2, 17.1ยฑ0.2, 22.0ยฑ0.2, and 24.9ยฑ0.2.
[0019] Preferably, the X-ray diffraction pattern of the Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt has diffraction peaks at the 2ฮธ angles of 3.2ยฑ0.1, 6.3ยฑ0.1, 13.2ยฑ0.1, 14.6ยฑ0.1, 19.2ยฑ0.1, and 32.6ยฑ0.1; or, preferably, the X-ray diffraction pattern of the crystal form of (6S)-5-methyltetrahydrofolate strontium salt has diffraction peaks at the 2ฮธ angles of 6.5ยฑ0.1, 10.0ยฑ0.1, 13.7ยฑ0.1, 16.8ยฑ0.1, 17.1ยฑ0.1, 22.0ยฑ0.1, and 24.9ยฑ0.1.
[0020] Another objective of the present invention is to provide methods for preparing the crystal form of (6S)-5-methyltetrahydrofolate salt.
[0021] The third objective of the present invention is to provide pharmaceutical compositions of the crystal form of (6S)-5-methyltetrahydrofolate salt.
[0022] The fourth objective of the present invention is to provide uses of the crystal form of (6S)-5-methyltetrahydrofolate salt.
[0023] The objectives of the present invention can be achieved according to the following ways:
[0024] A crystal form of (6S)-5-methyltetrahydrofolate salt is provided, where the crystal form is Form C of the crystal form of (6S)-5-methyltetrahydrofolic acid calcium salt or a crystal form of (6S)-5-methyltetrahydrofolate strontium salt.
[0025] In an aspect, the present invention provides Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt, where by using Cu-Ka radiation, the X-ray diffraction pattern has diffraction peaks at 2ฮธ of 6.3ยฑ0.2 and 19.2ยฑ0.2 in degree, especially has one or more diffraction peaks at 2ฮธ of 3.2ยฑ0.2, 6.3ยฑ0.2, 13.2ยฑ0.2, 14.6ยฑ0.2, 19.2ยฑ0.2, and 32.6ยฑ0.2, and preferably has one or more diffraction peaks at 2ฮธ of 3.2ยฑ0.1, 6.3ยฑ0.1, 13.2ยฑ0.1, 14.6ยฑ0.1, 19.2ยฑ0.1, and 32.6ยฑ0.1. The X-ray diffraction pattern of the Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt exhibits strong diffraction peaks and low background spectrum, indicating high crystallinity.
[0026] The further X-ray diffraction pattern of the Form C (6S)-5-methyltetrahydrofolic acid calcium salt is essentially shown in FIG. 1 . The chemical purity of the Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt is further greater than 99.0%.
[0027] In another aspect, the present invention provides a crystal form of (6S)-5-methyltetrahydrofolate strontium salt, where by using Cu-Ka radiation, the X-ray diffraction pattern has diffraction peaks at 2ฮธ of 6.5ยฑ0.2 and 22.0ยฑ0.2 in degree, especially has one or more diffraction peaks at 2ฮธ of 6.5ยฑ0.2, 10.0ยฑ0.2, 13.7ยฑ0.2, 16.8ยฑ0.2, 17.1ยฑ0.2, 22.0ยฑ0.2, and 24.9ยฑ0.2, and preferably has one or more diffraction peaks at 2ฮธ of 6.5ยฑ0.1, 10.0ยฑ0.1, 13.7ยฑ0.1, 16.8ยฑ0.1, 17.1ยฑ0.1, 22.0ยฑ0.1, and 24.9ยฑ0.1. The X-ray diffraction pattern of the crystal form of (6S)-5-methyltetrahydrofolate strontium salt exhibits strong diffraction peaks and low background spectrum, indicating high crystallinity.
[0028] The further X-ray diffraction pattern of the (6S)-5-methyltetrahydrofolate strontium salt is essentially shown in FIG. 2 .
[0029] In the present invention, the moisture content of the crystal form of (6S)-5-methyltetrahydrofolate salt is 10% to 18%, and further is 15% to 17%.
[0030] In still another aspect, the present invention provides a method for preparing a (6S)-5-methyltetrahydrofolate salt, where the method includes crystallizing (6S)-5-methyltetrahydrofolate salt from a polar medium through ultrasonic assistance.
[0031] In yet another aspect, the present invention provides a method for preparing a (6S)-5-methyltetrahydrofolate salt, specifically including the following steps:
[0032] (1) Neutralization of (6S)-5-methyltetrahydrofolic acid with a base in a polar medium to full dissolution; the polar medium may be water, deionized water, or a solution formed by water and an organic solvent capable of being mixed uniformly with water, and may also be a salt; a preferred polar medium is water and deionized water. The base is an inorganic base or organic base capable of forming a salt with (6S)-5-methyltetrahydrofolic acid, the inorganic base is selected from alkali metal bases or alkaline earth metal bases, carbonates and bicarbonates; the organic base is selected from ammonia, amines, pyridines or piperazines, where potassium hydroxide, sodium hydroxide, calcium hydroxide, potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, ammonia, methylamine, 4-dimethyl-pyridine or piperazine are preferred.
[0033] (2) Addition of an alkaline earth metal salt or an alkaline earth metal salt solution; the alkaline earth metal salt refers to an inorganic salt or organic salt that is soluble or partially solution in the polar medium, for example, calcium salt, magnesium salt, strontium salt, barium salt, and calcium chloride, hexahydrate calcium chloride and strontium chloride are preferred.
[0034] (3) Heating to a temperature higher than 30ยฐ C., especially to a temperature of 30ยฐ C. to 60ยฐ C. or 60ยฐ C. to 100ยฐ C.
[0035] (4) Introduction of ultrasonic waves and crystallization, and isolation of (6S)-5-methyltetrahydrofolate salt crystal.
[0036] Ultrasonic technology is a simple, inexpensive technique, and is safe and convenient in use. On one hand, ultrasonic wave can strength the nucleation and growth of crystals. In the crystallization process, the introduction of ultrasonic waves may cause cavitation phenomenon, when cavitation bubbles burst, a certain micro-jet is produced, the micro-jet crushes crystal grains having a certain size, and a part of the crushed crystals serve as seed for crystal growth, thereby promoting the growth of crystals. On the other hand, in the crystallization process, ultrasonic waves are equivalent to a catalyst, and excite the molecular motion through translation, rotation and reversal, thereby increasing the crystallization rate of the entire system, and shortening the crystallization time. The ultrasonic waves can also improve the particle size distribution of the product, and with the increase of the ultrasonic power, the crystal particles show a tendency of decrease. Since no other reagents are added and no contaminants are introduced in the crystallization process, the ultrasonic waves can be used to prepare very pure crystalline materials, and this is very important for some materials with very strict requirements for purity, especially pharmaceutical products and foods. Compared with other crystallization starting methods such as stimulation crystallization starting method and seed charging crystallization starting method, the degree of supersaturation required by ultrasonic crystallization is low, the growth speed is fast, the resulting crystal is uniform, complete and clean, the crystal size distribution range is small, and the coefficient of variation is low.
[0037] Ultrasonic waves have been used in crystalline area since 1927. In recent years, the utilization of ultrasonic waves in pharmaceutical and fine chemical industries is further promoted. Ishtiaq et al. reviewed the application of ultrasonic waves in the pharmaceutical field (World Applied sciences Journal (2009), 6(7), 856-893). However, so far, in the pharmaceutical industry, merely several papers and patents disclose and apply the ultrasonic crystallization technique, for example, paroxetine, aspartame, adipic acid, fenoterol hydrobromide (Organic Process Research & Development 2005, 9, 923-932).
[0038] The inventors apply ultrasonic waves in the field of crystallization of 5-methyltetrahydrofolic acid and salts thereof for the first time. We have found in experiments that when the ultrasonic power is 0.01 W/ml to 1.0 W/ml, the resulting crystal is uniform, complete, and clean, the crystal size distribution range is small, and the purity is high and is up to above 99.0%. Preferably, the ultrasonic power is 0.04 W/ml to 0.60 W/ml.
[0039] Neutralization with a base in Step (1) generally refers to neutralization to a pH value of about 7.0, generally neutralization to a pH value of 6.5 to 8.5, preferably neutralization to a pH value of 7.0 to 7.5, and most preferably neutralization to a pH value of 7.0. The base may be directly added, and may also be added in the form of a solution (for example, aqueous solution). This method has not specific requirements on the amount of the polar medium, and an amount for a general reaction or a crystallization medium is suitable.
[0040] When an alkaline earth metal salt solution is used in Step (2), generally a 5% to 50% aqueous solution of an alkaline earth metal salt, preferably a 25% to 50% aqueous solution of an alkaline earth metal salt, is used.
[0041] The heating temperature in Step (3) is 30ยฐ C. to 60ยฐ C. or 60ยฐ C. to 100ยฐ C., preferably 40ยฐ C. to 80ยฐ C., and more preferably 65ยฐ C. to 70ยฐ C.
[0042] In Step (4), after ultrasonic crystallization and isolation the crystal, a step of washing with water and drying (drying in vacuum at a temperature of 20ยฐ C. to 40ยฐ C.).
[0043] Preparation of the crystal form of (6S)-5-methyltetrahydrofolate salt by using ultrasonic waves can be carried out naturally or be carried out by introducing a corresponding (6S)-5-methyltetrahydrofolate salt seed.
[0044] In another aspect, the present invention relates to a composition containing at least one (6S)-5-methyltetrahydrofolate salt described above, since persons skilled in the art can understand based on the knowledge in the art that the composition of the present invention may further contain a pharmaceutically acceptable excipient or carrier. The carrier includes a diluent, a binder, a disintegrant, a lubricant, and an anti-oxidant, and these excipients are existing conventional excipients. The preparation form of the composition is an oral solid preparation or injection, for example, tablets, capsules, orally disintegrating tablets, lozenge, sustained-release preparations, injections, and lyophilized powder, prepared by adopting methods for corresponding formulations.
[0045] A preparation is provided, which contains an effective amount of the crystal form of (6S)-5-methyltetrahydrofolate salt.
[0046] In another aspect, the present invention discloses a use of the at least one (6S)-5-methyltetrahydrofolate salt and/or composition defined above in preparation of pharmaceuticals, food additives or nutritional supplements, where the pharmaceuticals, food additives, or nutritional supplements are used for preventing and/or treating defects or diseases positively impacted by administration of 5-methyltetrahydrofolate salt.
[0047] Merely for example, the (6S)-5-methyltetrahydrofolate salt and/or composition of the present invention defined above may be used in preparation of pharmaceuticals, food additives, or nutritional supplements. The pharmaceuticals, food additives, or nutritional supplements are used for preventing and/or treating neurological diseases such as subacute encephali associated with dementia and vacuolar myelopathy; physiological and pathological vascular and cardiovascular disorders such as premature occlusive arterial diseases, severe vascular diseases in infancy and childhood, progressive arterial stenosis, intermittent claudication, renal vascular hypertension, ischemic cerebrovascular diseases, premature occlusive retinal artery and retinal vein, cerebral occlusive arterial diseases, occlusive peripheral arterial diseases, and premature death caused by thromboembolic diseases and/or ischemic heart diseases; autoimmune diseases such as psoriasis, celiac disease, arthritis and inflammatory conditions; megaloblastic anemia caused by folate inefficiency, intestinal malabsorption, used as antidote for folic acid antagonists (for example, methotrexate, pyrimethamine or trimethoprim); used for preventing serious toxic effects caused by methotrexate overdose or high-dose therapy, reducing risks of woman miscarriage and/or production of fetuses with neural tube defects, cleft defects and/or palate defects, keeping and/or normalizing homocysteine levels and/or metabolism; changes synthesis of and/or functions and/or variations in DNA and RNA and changes in synthesis of cells; and depression.
[0048] The (6S)-5-methyltetrahydrofolate salt of the present invention exhibits long-term persistent chemical stability, and after long-term exposure in the air at a temperature of 40ยฐ C. and relative humidity of 60%, and the color of the crystal form has no significant changes, which is very important for application of the (6S)-5-methyltetrahydrofolate salt in pharmaceutical preparations.
[0049] In addition to the rare high chemical stability, it may also be noted that, the (6S)-5-methyltetrahydrofolate salt of the present invention has good dissolution rate, and in water at a temperature of 25ยฐ C., the saturated state can be quickly reached within 1 min. The high dissolution rate can not only improve the producibility of preparations for parenteral administration such as injections, thereby facilitating industrial production, and can also be made into oral preparations, thereby having important biopharmaceutical advantages in oral administration of pharmaceuticals, because the high dissolution rate of the active pharmaceuticals improves the absorption rate of the active pharmaceuticals through the gastrointestinal wall. Additionally, the crystal form of the present invention further has the advantages of high crystallinity, uniform particle distribution, smooth surface, and high chemical purity of up to above 99.0%.
[0050] The method for preparing the crystal form of (6S)-5-methyltetrahydrofolate salt of the present invention has the advantages that the reaction steps are simple, no pollution occurs, the obtained novel crystal form of (6S)-5-methyltetrahydrofolic acid calcium salt has high chemical stability, high purity, high dissolution rate, and high bioavailability, thereby providing a novel way for preparing (6S)-5-methyl-tetrahydrofolate crystalline salt.
[0051] The crystal form of (6S)-5-methyltetrahydrofolate salt of the present invention has the advantages of excellent physicochemical properties, good stability, high purity, good reproducibility, and being more suitable for production on an industrial scale.
BRIEF DESCRIPTION OF DRAWINGS
[0052] The disclosure will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the disclosure, and wherein:
[0053] FIG. 1 shows an X-ray diffraction pattern of Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt;
[0054] FIG. 2 shows an X-ray diffraction pattern of the crystal form of (6S)-5-methyltetrahydrofolate strontium salt; and
[0055] FIG. 3 shows the particle diameter distribution of Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt obtained through the preparation method of the present invention.
DETAILED DESCRIPTION
[0056] Without further description, by means of the previous description, persons skilled in the art can implement the present invention to the maximum. The following preferred specific embodiments are just examples, and in no way limit the disclosure of the present invention.
Embodiment 1
[0057] 15.0 g (6S)-5-MTHF was added to 325 ml deionized water, and 10% NaOH solution was added with stirring for neutralization to a pH value of 7.8 till (6S)-5-MTHF was fully dissolved. Next, 37.5 g calcium chloride solution (containing 9.0 g calcium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.04 W/ml at a temperature of 72ยฐ C., and after 40 min-ultrasonic reaction, the reaction solution was filtered, and washed with water, ethanol and acetone respectively. After drying in vacuum at 25ยฐ C., 13.5 g white Form C of (6S)-5-MTHF calcium salt was obtained. The chemical purity is 99.25% (detected by HPLC), and the moisture content is 10.67%.
Embodiment 2
[0058] 10.0 g (6S)-5-MTHF was added to 250 ml water, and 10% NaOH solution was added with stirring for neutralization to a pH value of 7.4 till (6S)-5-MTHF was fully dissolved. Next, 25 g calcium chloride solution (containing 6.0 g calcium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.03 W/ml at a temperature of 60ยฐ C., and after 40 min-ultrasonic reaction, the reaction solution was filtered, and washed with water and acetone. After drying in vacuum at 30ยฐ C., 9.2 g white Form C of (6S)-5-MTHF calcium salt was obtained. The chemical purity is 99.01% (detected by HPLC), and the moisture content is 15.8%.
Embodiment 3
[0059] 10.0 g (6S)-5-MTHF was added to 150 ml water, and ammonia was added with stirring for neutralization to a pH value of 7.4 till (6S)-5-MTHF was fully dissolved. Next, 12 g calcium chloride solution (containing 3.0 g calcium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.05 W/ml at a temperature of 40ยฐ C., and after 100 min-ultrasonic reaction, the reaction solution was filtered, and washed with water and acetone. After drying in vacuum at 25ยฐ C., 9.0 g white Form C of (6S)-5-MTHF calcium salt was obtained. The chemical purity is 99.60% (detected by HPLC), and the moisture content is 17.76%.
Embodiment 4
[0060] 40.0 g (6S)-5-MTHF was added to 1,000 ml water, and 10% NaOH solution was added with stirring for neutralization to a pH value of 7.8 till (6S)-5-MTHF was fully dissolved. Next, 96 g calcium chloride solution (containing 24 g calcium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.56 W/ml at a temperature of 90ยฐ C., and after 30 min-ultrasonic reaction, the reaction solution was filtered, and washed with water and acetone. After drying in vacuum at 25ยฐ C., 36.0 g white Form C of (6S)-5-MTHF calcium salt was obtained. The chemical purity is 99.77% (detected by HPLC), and the moisture content is 16.39%.
Embodiment 5
Strontium Salt
[0061] 6.0 g (6S)-5-MTHF was added to 150 ml water, and 10% NaOH solution was added with stirring for neutralization to a pH value of 7.3 till (6S)-5-MTHF was fully dissolved. Next, 7.29 g strontium chloride solution (containing 1.8 g strontium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.30 W/ml at a temperature of 70ยฐ C., and after 20 min-ultrasonic reaction, the reaction solution was filtered, and washed with water and acetone. After drying in vacuum at 25ยฐ C., 4.2 g white (6S)-5-MTHF strontium salt was obtained. The chemical purity is 97.57% (detected by HPLC), and the moisture content is 15.02%.
Embodiment 6
[0062] 9.0 g (6S)-5-MTHF was added to 225 ml water, and 10% NaOH solution was added with stirring for neutralization to a pH value of 7.1 till (6S)-5-MTHF was fully dissolved. Next, 10.2 g calcium chloride solution (containing 2.7 g calcium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.20 W/ml at a temperature of 70ยฐ C., and after 20 min-ultrasonic reaction, the reaction solution was filtered, and washed with water and acetone. After drying in vacuum at 25ยฐ C., 6.1 g white Form C of (6S)-5-MTHF calcium salt was obtained. The chemical purity is 99.08% (detected by HPLC), and the moisture content is 15.20%.
Embodiment 7
[0063] 18.0 g (6S)-5-MTHF was added to 450 ml water, and 10% NaOH solution was added with stirring for neutralization to a pH value of 7.3 till (6S)-5-MTHF was fully dissolved. Next, 21.6 g calcium chloride solution (containing 5.4 g calcium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.04 W/ml at a temperature of 70ยฐ C., and after 30 min-ultrasonic reaction, the reaction solution was filtered, and washed with water and acetone. After drying in vacuum at 25ยฐ C., 13.9 g white Form C of (6S)-5-MTHF calcium salt was obtained. The chemical purity is 99.53% (detected by HPLC), and the moisture content is 16.4%.
Embodiment 8
[0064] 2.0 g (6S)-5-MTHF was added to 50 ml water, and sodium hydroxide was added with stirring for neutralization to a pH value of 7.2 till (6S)-5-MTHF was fully dissolved. Next, 2 g calcium chloride solution (containing 0.5 g calcium chloride) was added, the resulting reaction solution was transferred into an ultrasonic reactor having a power density of 0.05 W/ml at a temperature of 50ยฐ C., and after 60 min-ultrasonic reaction, the reaction solution was filtered, and washed with water and acetone. After drying in vacuum at 40ยฐ C., 1.0 g white Form C of (6S)-5-MTHF calcium salt was obtained. The chemical purity is 99.01% (detected by HPLC), and the moisture content is 15.6%.
[0065] Although the above specific embodiments merely disclose the preparation methods of the (6S)-5-methyltetrahydrofolic acid calcium salt crystal and the (6S)-5-methyltetrahydrofolate strontium salt crystal, persons skilled in the art can prepare other types of (6S)-5-methyltetrahydrofolate salt crystals according to the teaching of the preparation methods, particularly the (6S)-5-methyltetrahydrofolic acid alkaline earth metal salt crystals.
Embodiment 9
Stability Study
[0066] In order to determine the stability of the novel crystal form of the Form C of (6S)-5-MTHF calcium salt, the crystal form was placed in the air at a temperature of 40ยฐ C. and a relative humidity of 60%, and the content of remained (6S)-5-MTHF calcium salt was periodically measured.
[0000]
Crystal Form
Storage Days
Appearance
Content
Form C
0
White crystal
99.5%
3
White crystal
99.1%
6
White crystal
99.1%
9
White crystal
98.4%
[0067] The results show that the Form C of (6S)-5-MTHF calcium salt has good stability, which is beneficial to the production and storage of pharmaceutical preparations.
Embodiment 10
Particle Diameter Distribution of the Form C of the Crystal Form of (6S)-5-Methyltetrahydrofolate Calcium Salt
[0068] FIG. 3 shows the particle diameter distribution of the Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt obtained through the preparation method of the present invention. It can be seen from FIG. 3 that, the particle size is in normal distribution, indicating that the crystal treated by ultrasonic waves has a relatively uniform particle size.
Embodiment 11
Conditions and Data of the X-Ray Diffraction Pattern of the Crystal Form
[0069] Instrument: Bruker DS advance XRD
[0070] Diffraction ray: CuKฮฑ (40 kV, 40 mA)
[0071] Scanning rate: 80ยฐ/min (2ฮธ value)
[0072] Scanning range: 2ยฐ to 45ยฐ (2ฮธ value)
[0073] Peak Search Report (37 Peaks, Max P/N=46.1)
[0074] PEAK: 35-pts/Parabolic Filter, Threshold=3.0, Cutoff=0.1%, BG=3/1.0, PeakโTop=Sumnmit
[0000]
#
2-Theta
d(A)
BG
Height
I %
Area
I %
FWHM
1
3.151
28.0163
612
8740
89.06
165950
100.00
0.343
2
6.309
13.9974
689
9814
100.00
155754
93.86
0.286
3
9.447
9.3545
681
1601
16.31
16953
10.22
0.309
4
13.199
6.7022
913
4338
44.20
46545
28.05
0.228
5
13.612
6.4999
1029
2121
21.61
14775
8.90
0.227
6
14.166
6.2469
1072
1514
15.43
12344
7.44
0.441
7
14.639
6.0462
1057
4630
47.18
52370
31.56
0.246
8
15.329
5.7755
1055
1310
13.35
2233
1.35
0.147
9
16.001
5.5343
1133
2147
21.88
18187
10.96
0.301
10
16.534
5.3572
958
1409
14.36
15394
9.28
0.539
11
17.046
5.1973
1089
2406
24.52
14700
8.86
0.187
12
18.824
4.7103
1017
3484
35.50
74762
45.05
0.479
13
19.158
4.6288
1118
3998
40.74
84209
50.74
0.491
14
20.125
4.4085
1295
3176
32.36
30820
18.57
0.275
15
20.976
4.2316
1169
2397
24.42
22579
13.61
0.308
16
21.411
4.1466
1068
1503
15.31
5525
3.33
0.213
17
22.614
3.9287
863
1716
17.49
13799
8.32
0.271
18
24.073
3.6937
857
1619
16.50
9785
5.90
0.215
19
24.785
3.5892
884
1719
17.52
26584
16.02
0.503
20
25.022
3.5558
898
1971
20.08
26647
16.06
0.417
21
25.914
3.4354
884
1390
14.16
7075
4.26
0.235
22
26.858
3.3168
846
1262
12.86
10476
6.31
0.423
23
27.334
3.2601
852
1244
12.68
8923
5.38
0.359
24
27.674
3.2207
901
1048
10.68
1050
0.63
0.113
25
28.358
3.1446
915
1606
16.36
15814
9.53
0.384
26
28.908
3.0860
913
1339
13.64
16265
9.80
0.641
27
29.444
3.0310
977
1419
14.46
9424
5.68
0.358
28
30.251
2.9520
921
1248
12.72
3742
2.25
0.192
29
30.769
2.9035
880
1518
15.47
9728
5.86
0.256
30
31.537
2.8345
836
1196
12.19
4349
2.62
0.203
31
32.602
2.7443
813
1863
18.98
21721
13.09
0.347
32
35.722
2.5115
617
929
9.47
4980
3.00
0.268
33
37.675
2.3856
659
1229
12.52
10784
6.50
0.317
34
38.819
2.3179
633
884
9.01
5939
3.58
0.397
35
40.263
2.2381
607
776
7.91
4592
2.77
0.429
36
42.037
2.1476
580
988
10.07
14181
8.55
0.583
37
43.615
2.0735
563
841
8.57
6633
4.00
0.400
Embodiment 12
Conditions and Data of the X-Ray Diffraction Pattern of the Crystal Form of Strontium Salt
[0075] Instrument model: Bruker D8 advance XRD
[0076] Diffraction ray: CuKฮฑ (40 kv, 40 mA)
[0077] Scanning rate: 8ยฐ/min (2ฮธ value)
[0078] Scanning range: 5ยฐ to 45ยฐ (2ฮธ value)
[0079] Peak Search Report (36 Peaks, Max P/N=20.9)
[0080] PEAK: 29-pts/Parabolic Filter, Threshold=3.0, Cutoff=0.1%, BG=3/1.0, PeakโTop=Summit
[0000]
#
2-Theta
d(A)
BG
Height
I %
Area
I %
FWHM
1
6.54
13.503
581
2213
100
46131
100
0.354
2
7.496
11.7831
565
96
4.3
1563
3.4
0.277
3
8.38
10.5426
570
136
6.1
2418
5.2
0.302
4
9.96
8.8736
610
1379
62.3
35198
76.3
0.434
5
12.339
7.1672
647
292
13.2
5831
12.6
0.339
6
13.66
6.4772
902
604
27.3
20626
44.7
0.581
7
14.22
6.2232
826
413
18.7
26525
57.5
1.092
8
14.741
6.0044
940
355
16
5431
11.8
0.26
9
15.58
5.6828
842
199
9
3770
8.2
0.322
10
16.279
5.4403
1049
239
10.8
2625
5.7
0.187
11
16.8
5.2729
815
533
24.1
28957
62.8
0.924
12
17.14
5.169
898
672
30.4
16152
35
0.409
13
18.28
4.8492
796
664
30
16290
35.3
0.417
14
19.54
4.5393
819
598
27
15788
34.2
0.449
15
20.3
4.371
779
328
14.8
5046
10.9
0.262
16
22.02
4.0334
699
1281
57.9
31787
68.9
0.422
17
23.259
3.8211
764
131
5.9
2094
4.5
0.272
18
24.399
3.6451
944
589
26.6
22484
48.7
0.649
19
24.92
3.5702
911
788
35.6
34957
75.8
0.754
20
26.42
3.3707
830
673
30.4
12784
27.7
0.323
21
27.999
3.1841
838
310
14
5810
12.6
0.319
22
28.961
3.0805
851
249
11.3
4360
9.5
0.298
23
29.881
2.9877
723
138
6.2
2168
4.7
0.267
24
30.84
2.897
679
190
8.6
3775
8.2
0.338
25
32.04
2.7912
678
220
9.9
7951
17.2
0.614
26
32.44
2.7577
683
157
7.1
7115
15.4
0.77
27
33.12
2.7026
662
190
8.6
2851
6.2
0.255
28
34.12
2.6256
655
149
6.7
4534
9.8
0.517
29
35.041
2.5587
674
88
4
2007
4.4
0.388
30
37.179
2.4163
663
223
10.1
8948
19.4
0.682
31
37.723
2.3827
689
142
6.4
7683
16.7
0.92
32
39.78
2.2641
592
373
16.9
9421
20.4
0.429
33
41.019
2.1985
577
122
5.5
3827
8.3
0.533
34
42.84
2.1092
648
445
20.1
17304
37.5
0.661
35
43.298
2.0879
726
211
9.5
10128
22
0.816
36
44.321
2.0421
683
153
6.9
4026
8.7
0.447
[0081] Therefore, the present invention relates to the crystal form of (6S)-5-methyltetrahydrofolate salt prepared by the above method.
[0082] The crystal form of (6S)-5-methyltetrahydrofolate salt is:
[0083] (a) Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.3ยฑ0.2 and 19.2ยฑ0.2; or
[0084] (b) Crystal form of (6S)-5-methyltetrahydrofolate strontium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.5ยฑ0.2 and 22.0ยฑ0.2.
[0085] Preferably, the crystal form of (6S)-5-methyltetrahydrofolate salt is:
[0086] (a) Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 3.2ยฑ0.2, 6.3ยฑ0.2, 13.2ยฑ0.2, 14.6ยฑ0.2, 19.2ยฑ0.2 and 32.6ยฑ0.2; or
[0087] (b) the crystal form of (6S)-5-methyltetrahydrofolate strontium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.5ยฑ0.2, 10.0ยฑ0.2, 13.7ยฑ0.2, 16.8ยฑ0.2, 17.1ยฑ0.2, 22.0ยฑ0.2 and 24.9ยฑ0.2.
[0088] Preferably, the crystal form of (6S)-5-methyltetrahydrofolate salt is:
[0089] (a) Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 3.2ยฑ0.1, 6.3ยฑ0.1, 13.2ยฑ0.1, 14.6ยฑ0.1, 19.2ยฑ0.1 and 32.6ยฑ0.1; or
[0090] (b) the crystal form of (6S)-5-methyltetrahydrofolate strontium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.5ยฑ0.1, 10.0ยฑ0.1, 13.7ยฑ0.1, 16.8ยฑ0.1, 17.1ยฑ0.1, 22.0ยฑ0.1 and 24.9ยฑ0.1.
[0091] Specifically, the crystal form of (6S)-5-methyltetrahydrofolate salt is:
[0092] (a) X-ray diffraction pattern of the Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt is essentially shown in FIG. 1 ; or
[0093] (b) X-ray diffraction pattern of the crystal form of (6S)-5-methyltetrahydrofolate strontium salt is essentially shown in FIG. 2 .
[0094] The preferred or specific embodiments of the present invention are described above in detail. It should be understood that persons skilled in the art can make various modifications and variations according to the design concept of the present invention without any creative work. Therefore, all technical solutions that can be obtained by persons skilled in the art through logical analysis, reasoning or limited experiments based on the prior art according to the design concept of the present invention shall fall within the scope of the present invention and/or the protection scope defined by the claims.
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Disclosed are a crystal form of (6S)-5-methyltetrahydrofolate salt and a method for preparing the same. The crystal form is: Form C of the crystal form of (6S)-5-methyltetrahydrofolate calcium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.3ยฑ0.2 and 19.2ยฑ0.2; or the crystal form of (6S)-5-methyltetrahydrofolate strontium salt, where the X-ray diffraction pattern has diffraction peaks at the 2ฮธ angles of 6.5ยฑ0.2 and 22.0ยฑ0.2. The crystal form of (6S)-5-methyltetrahydrofolate salt of the present invention has the advantages of excellent physicochemical properties, good stability, high purity, good reproducibility, and being more suitable for production on an industrial scale.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims priority from co-pending U.S. Provisional Patent Application Ser. No. 61/823,223 entitled โPLANAR ANTENNA SYSTEMโ filed with the U.S. Patent and Trademark Office on May 14, 2013, by the inventors herein, the specification of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to antenna systems and methods. More particularly, the present invention relates to antenna feeding systems to feed antennas made of resistive materials and antenna feeding design and manufacturing methods for overcoming adverse effects caused by losses in such resistive materials.
BACKGROUND OF THE INVENTION
[0003] A number of resistive sheet or resistive layer antenna designs and systems exist within various industries for providing a partly conductive and at the same time optically transparent layer of material for multiple applications. An antenna feeding mechanism is associated with each of these antenna systems. The sheet resistivity and the light transparency of the resistive sheet are the key factors that determine the implementation of a resistive sheet antenna. In general, an antenna made of a resistive transparent sheet, such as Indium tin oxide, experience losses several orders of magnitude larger than an antenna made of a conductive material such as copper or silver. Therefore, antennas are primarily made of a conductive material, if possible. However, conductive materials are opaque to light. As a result, in certain applications requiring the use of a transparent antenna, a conductive material cannot be used.
[0004] In recent years, the demand for transparent antennas has increasingly grown for touchscreen, mobile platform, and automobile applications. In particular, the implementation of antennas, made of a transparent conductive layer, on the display window of a portable communication device have been addressed in the prior art, as described in U.S. Pat. No. 7,983,721 to Ding et al., the specification of which is incorporated herein by reference in its entirety. However, these efforts have faced certain challenges and limitations. Particularly, attempts made to provide an antenna design sufficiently transparent to light and at the same time capable of performing at radiation efficiency levels set up by industry standards have not been successful. A major challenge is that as the sheet resistivity of a resistive sheet decreases, making the resistive sheet more conductive, the optical transparency of the resistive sheet decreases. Likewise, as the sheet resistivity increases, the power dissipated as heat as a result of currents flowing on the resistive sheet increases too. Accordingly, the radiated power and the radiation efficiency of the resistive sheet are reduced, making it very challenging for resistive sheet antennas to meet radiation efficiency industry standards.
[0005] As a result, a compromise is required between two conflicting goals. Firstly, making the resistive sheet as conductive as possible, which means less transparent; and secondly, making the antenna more optically transparent, which means a more resistive sheet having a larger sheet resistivity. Current technology offers optically transparent resistive sheets having a sheet resistivity larger than 10 Ohms per square. However, for these values of sheet resistivity, standard design techniques used for antennas made of conductive materials notably fail.
[0006] The antenna feeding mechanism plays a crucial role in the overall radiation efficiency of the feeding-antenna system. Typically, standard feeding design techniques will enable the excitation of radiofrequency (RF) currents on the resistive sheet antenna at the expense of significant power losses. Two key reasons account for these losses: first, usually there are large concentrations of RF currents on the resistive sheet at the transitioning area between the transmission line used to feed the antenna and the resistive sheet antenna; and second, the non-uniform distribution of RF current densities excited on the resistive sheet. In general, the amount of power losses significantly increases as the sheet resistivity increases.
[0007] Moreover, in placing an antenna or a feeding mechanism close to conductive or resistive materials, electromagnetic coupling between the antenna and these materials also contributes to power losses that decrease the effective radiated power at a system level. In most touchscreen and mobile platform applications, the antenna-feeding system is surrounded by a number of conductive and resistive materials that must be considered, especially when designing an antenna using resistive sheets, to maximize the overall radiated power. Accordingly, manufacturers intending to use a resistive sheet on the touchscreen area as an antenna experience either an unacceptable reduction in radiation efficiency or an unacceptable performance of the touchscreen. This leads manufacturers to implementation of antenna systems that are costly, aesthetically unappealing, or more importantly, highly inefficient.
[0008] Previous efforts have been made to develop a method of improving the radiation efficiency of antennas made of transparent resistive sheet, as described in U.S. Pat. No. 7,233,296 to Song, et al., the specification of which is incorporated herein by reference in its entirety. However, this method is primarily aimed at determining values for current density over the surface of the resistive sheet to identify regions having concentrated flow of currents. Then the antenna efficiency is improved by increasing the conductivity in such areas of high current concentration.
[0009] The method described in the patent to Song et al., has also faced severe challenges and limitations. In particular, the resulting resistive layer will not be optically homogeneous. In other words, there will be areas of the resistive layer having darker spots resulting from the increased conductivity. Thus, although the resistive layers may meet optical transparency functional requirements, the resistive layer will not be aesthetically appealing. Furthermore, the manufacturing process used to provide different regions with different conductivity increases costs. Moreover, and more importantly, the areas of high-current concentration will vary depending on the type of application, the user operation, and the surrounding areas to the resistive sheet. Accordingly, small areas of higher conductivity on the resistive sheet may not cover a shift of the high-current spots. Alternatively, increasing the size of the areas of higher conductivity (darker areas) on the resistive sheet may further compromise the aesthetics and the optical transparency of the resistive sheet.
[0010] Furthermore, Bayram et al., as described in copending and co-owned U.S. patent application Ser. No. 14/252,975 titled โAntenna and Method for Optimizing the Design Thereofโ (the specification of which is incorporated herein by reference in its entirety), have disclosed an approach for improving the radiation efficiency of a resistive sheet antenna, based on the topology design of the resistive sheet. In this approach, the radiation efficiency of the antenna is primarily increased by either reducing or preventing RF current โhot spotsโ and โpinch pointsโ flowing on the resistive sheet. While this approach is effective in reducing or preventing high concentrations of RF currents, once they are flowing on the resistive sheet, a major limitation may result where the feeding mechanism is based on standard feeding designs. As a result, this approach is not able to prevent the non-uniform distribution of RF current densities and large concentrations of RF currents on the resistive sheet at the transitioning area between the transmission line used to feed the antenna and the resistive sheet antenna. Thus, even if the radiation efficiency of the antenna is improved, the power losses at the feeding transitioning area may result in an overall efficiency of the feeding-antenna system that is unacceptable to meet industry standards.
[0011] An RF current โhot spotโ is characterized by a region of a material wherein a concentration of RF current is present having significantly larger current levels as compared to other regions having a more uniform current distribution and lower current levels. In particular, for a resistive sheet, a โhot spotโ region dissipates a substantial amount of power as heat, significantly reducing the amount of radiated power.
[0012] Likewise, an RF current โpinch pointโ is characterized by a region of a material wherein the physical configuration of the material forces the RF current to converge creating high concentration of current levels. Thus, a narrow region of a material will have larger current densities as compared to a wider region of the same material. Accordingly, a โpinch pointโ in a resistive material will result in a substantial amount of power dissipated as heat, significantly reducing the amount of radiated power. Therefore, for a resistive sheet to be able to radiate power and operate as an antenna, it is as critical to avoid RF current โhot spotsโ and โpinch pointsโ at both the feeding transitioning area and on the resistive sheet.
[0013] A way to address the disadvantages of the efforts attempted by the prior art is to design a feeding mechanism adapted to the topology of the resistive sheet antenna. This would make it possible to increase the radiation efficiency of the overall feeding-antenna system by identifying and mitigating or eliminating the sources of losses experienced both at the feeding transitioning area and as current flows on the resistive sheet. In particular, a feeding topology may be designed to uniformly distribute RF currents on the topology of the resistive sheet that prevent RF current โhot spotsโ and โpinch points,โ resulting in substantial increase of radiation efficiency.
[0014] Currently, there is no well-established method of deterministically creating a topology configuration of a feeding mechanism that adapts to the topology of a resistive sheet antenna, to optimize the radiation efficiency of the feeding-antenna system, especially for resistive sheets having a sheet resistivity greater than 10 Ohms per square.
[0015] Thus, there remains a need in the art for antenna feeding systems and methods to feed resistive sheet antennas that are capable of operating at radiation efficiencies that avoid the problems of prior art systems and methods.
SUMMARY OF THE INVENTION
[0016] An antenna feeding system and method of optimizing the design of the feeding system to feed an antenna made of a resistive sheet, or equivalently a resistive layer, is disclosed herein. One or more aspects of exemplary embodiments provide advantages while avoiding disadvantages of the prior art. The system and method are operative to design a topology of the antenna feeding system to adapt to a topology of the resistive sheet antenna to mitigate the adverse effects caused by the inherent losses of resistive sheets while operating as antennas. The system is designed to reduce a convergence of RF currents that may create a localized high density current concentration, such as โhot spotsโ and โpinch points,โ on the resistive sheet, by a sufficient extent so as to prevent power losses that substantially decrease the radiation efficiency of the antenna as compared with antennas using feeding systems designed following traditional design techniques.
[0017] The overall radiation efficiency of the resistive sheet antenna-feeding system depends not only on the topology of the resistive sheet antenna but also on how efficiently the feeding system is able to excite RF currents on the antenna. An antenna feeding system designed according to the method described herein is able to uniformly distribute the currents that flow from the feeding system into the resistive sheet antenna, reducing the power dissipated as heat. Accordingly, more power is radiated by the resistive sheet, improving the radiation efficiency of the antenna.
[0018] An antenna topology that provides wide areas and smooth edges wherein current flows to yield a more uniform current density distribution, by preventing localized high density current concentration, on the resistive sheet may result in a substantially higher antenna radiation efficiency. In particular, wide areas of the resistive sheet contribute to prevent RF current โpinch points,โ while smooth edges contribute to avoid RF current โhot spots,โ especially at contracted, corner, junction, bend, peripheral, or sharp regions of said resistive sheet, where significant RF power is dissipated as heat instead of being radiated.
[0019] Therefore, to substantially increase the radiation efficiency of the resistive sheet antenna-feeding system, it is critical for the antenna feeding system to meet two requirements: first, to be able to excite RF currents that flow uniformly distributed on the resistive sheet; and second, to prevent localized high current density concentrations at the feeding area. An antenna feeding system designed according to the method described herein is able to meet these two requirements by adapting the topology of the feeding system to that of the resistive sheet antenna. In addition, this topology adaptation may take into consideration the input impedance matching between the antenna and the transmission line feeding the antenna, which is also a key factor impacting the radiation efficiency of any antenna.
[0020] The determination of the topology configuration of the antenna feeding system is based on the physical dimensions of the design of the resistive sheet antenna. Specifically, the area of the antenna feeding system in which the RF currents flow, to be able to excite the resistive sheet, is disposed such that said area is within a contour defined by the periphery of the topology of the resistive sheet antenna. In addition, the topology of the feeding system provides wide areas and smooth edges to prevent โhot spotsโ and โpinch pointsโ on the resistive sheet at the feeding area. Moreover, the topology of the feeding system transitions into the specific transmission line feeding the antenna to provide a proper impedance matching.
[0021] The method to design an adaptive feeding system to feed a resistive sheet antenna that results in a significantly higher radiation efficiency as compared to standard techniques includes the step of determining an initial topology of the antenna feeding system having an area, in which the RF currents flow, that is smaller than the area defined by the periphery of the topology of the resistive sheet antenna. The method further includes the steps of coupling the antenna feeding to the resistive sheet antenna and adapting the initial topology of the antenna feeding, through alternative topology designs, to enable the excitation of RF currents that flow as uniformly as possible over the resistive sheet antenna, reducing RF current โhot spotsโ and RF current โpinch points.โ The method further includes the step of selecting the feeding transitioning topology most suitable to the transmission line to be used for the intended application of said antenna, in terms of performance or other predetermined criteria.
[0022] By significantly reducing the losses caused by currents flowing over a resistive sheet by means of determining a suitable topology of the antenna feeding system and by increasing the uniform distribution of the current density flowing on the resistive sheet, the adaptive antenna feeding system and method are able to provide outcomes that significantly increase the radiation efficiency of the resistive sheet antenna-feeding system, as compared to designs using standard techniques. This increase in radiation efficiency may be multiple times larger, resulting in designs that meet or exceed challenging industry standards, in terms of antenna radiation performance and optical transparency, for a resistive sheet antenna.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The numerous advantages of the present invention may be better understood by those skilled in the art by reference to the accompanying drawings in which:
[0024] FIG. 1 shows an exemplary embodiment of a planar, semi-elliptical adaptive feeding system used to feed a semi-elliptical resistive sheet antenna.
[0025] FIG. 2 shows a graph of antenna radiation efficiency, as a function of frequency, of a resistive sheet antenna having a 25 Ohm per square sheet resistivity for different feeding mechanisms.
[0026] FIG. 3 shows a graph of antenna radiation efficiency, as a function of frequency, of a resistive sheet antenna having an adaptive feeding antenna system for different values of sheet resistivity.
[0027] FIG. 4 shows an adaptive feeding system used to feed a two-element semi-elliptical resistive sheet antenna, in accordance with another exemplary embodiment.
[0028] FIG. 5 shows an adaptive feeding system using a coplanar waveguide implemented on a flexible substrate, in accordance with another exemplary embodiment.
[0029] FIG. 6 shows an electronic device implemented on a flexible substrate.
[0030] FIG. 7 shows a multilayer structure showing an arrangement of multiple antennas at different layers for various applications.
[0031] FIG. 8 shows a schematic view of a method for designing an adaptive feeding system to feed a resistive sheet antenna.
DESCRIPTION
[0032] The following description is of one or more aspects of the invention, set out to enable one to practice an implementation of the invention, and is not intended to any specific embodiment, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.
[0033] FIG. 1 shows an exemplary configuration of an antenna-feeding system 10 , in accordance with aspects of an embodiment of the invention, comprising a planar antenna element 12 , a coplanar waveguide 14 , and a feeding coupling element 19 . Antenna element 12 comprises a resistive layer, consisting of an Indium tin oxide-based film. The topology of antenna element 12 has a semi-elliptical configuration, comprising a first edge 15 , primarily having a linear shape, and a second edge 18 , having an elliptical shape. Second edge 18 is elliptically shaped according to an ellipse with a major axis of 20 mm, parallel to first edge 15 , and a major-to-minor axes ratio of 1.05. Accordingly, first edge 15 and second edge 18 join at two regions defining corners 13 a and 13 b of antenna element 12 . Moreover, each corner 13 a , 13 b of antenna element 12 is shaped to follow an elliptical shape according to an ellipse of major axis 2.2 mm and a major-to-minor axes ratio of 1.05.
[0034] Coplanar waveguide 14 is implemented by means of a thin layer of conductive feed line 20 and a ground plane structure formed by two thin layers of 8-mm wide by 13-mm long rectangular sections made of conductive material, 16 a and 16 b , disposed on each side of feed line 20 at a distance of about 1.1 mm from feed line 20 . Conductive feed line 20 has a rectangular shape, having a width of approximately 3 mm and a length of about 15 mm, and comprises a first end 17 opposite antenna element 12 and a second end 21 proximate to antenna element 12 . Conductive feed line 20 transitions into feeding coupling element 19 at second end 21 , wherein antenna element 12 adjoins feed line 20 of coplanar waveguide 14 .
[0035] Ground plane sections 16 a and 16 b are disposed coplanar with and generally parallel to feed line 20 of coplanar waveguide 14 .
[0036] First end 17 of feed line 20 is electrically connected, directly or indirectly, to a receiver (not shown) or a transmitter (not shown). Also, first end 17 of feed line 20 is aligned with each end of ground plane sections 16 a and 16 b opposing second end 21 of feed line 20 . Therefore, feed line 20 extends by 2 mm from each end of ground plane sections 16 a and 16 b proximate to second end 21 of feed line 20 . In other words, there is a gap of at least 2 mm between ground plane sections 16 a and 16 b and antenna element 12 .
[0037] Second end 21 of feed line 20 is electrically connected to feeding coupling element 19 . Feeding coupling element 19 transitions the feeding mechanism of antenna element 12 from a rectangular configuration of second end 21 of feed line 20 to a semielliptical configuration to adapt to the topology of antenna element 12 . Thus, the topology of feeding coupling element 19 has a semi-elliptical configuration, comprising a first edge 22 , primarily having a linear shape, and a second edge 23 , having an elliptical shape. Second edge 23 of feeding coupling element 19 is elliptically shaped according to the topology of antenna element 12 following an ellipse with a major axis of 20 mm and a major-to-minor axes ratio of 1.15.
[0038] An area within the peripheral boundary defined by the topology of antenna element 12 fully overlaps with an area within the peripheral boundary defined by the topology of feeding coupling element 19 . In general, the area defined by feeding coupling element 19 is smaller than the area defined by antenna element 12 such that second end 21 is within the peripheral boundary of antenna element 12 . In the configuration shown in FIG. 1 , feeding coupling element 19 extends 1 mm from second end 21 of feeding line 20 into antenna element 12 . Feeding coupling element 19 physically and electrically couples with antenna element 12 . Antenna element 12 attaches to feeding coupling element 19 over the overlapping region by means of a conductive adhesive. Alternatively, feeding coupling element 19 may electromagnetically couple, i.e., connect capacitively or inductively, to antenna element 12 . Furthermore, feeding coupling element 19 may attach to antenna element 12 by means of soldering or any other conductive material.
[0039] In particular, feeding coupling element 19 is designed adaptively to the topology of antenna element 12 to smoothly transition RF currents carried by feed line 20 into antenna element 12 or carried by antenna element 12 into feed line 20 . Likewise, the adaptive design of feeding coupling element 19 enables a more uniform flow of RF currents over as much area as possible of antenna element 12 , while preventing RF current โpinch pointsโ or โhot spots,โ within the limitations of an intended application for antenna-feeding system 10 . As a result a significantly higher antenna radiation efficiency may be achieved as compared to antenna-feeding systems using standard feeding designs.
[0040] Those skilled in the art will recognize that antenna element 12 and coplanar waveguide 14 may be disposed coplanar or non-coplanar either on the same or different rigid or flexible substrates. Similarly, ground plane sections 16 a and 16 b of coplanar waveguide 14 may have different shapes and dimensions. Also, the topology of antenna element 12 may take on a geometrical configuration other than semi-elliptical. Correspondingly, feeding coupling element 19 may be configured to adapt to the topology of antenna element 12 .
[0041] Likewise, those skilled in the art will realize that in instances wherein RF currents are of negligible value in a region or regions of antenna element 12 or feeding coupling element 19 , feeding coupling element 19 does not need to be designed adaptively to the topology of antenna element 12 to smoothly transition RF currents carried by feed line 20 into antenna element 12 or carried by antenna element 12 into feed line 20 . In these instances, the region or regions of antenna element 12 or feeding coupling element 19 wherein RF currents are of negligible value can be removed without affecting performance of antenna system 10 .
[0042] FIG. 2 shows a graph of antenna radiation efficiency, as a function of frequency, calculated by a well-known and commercially available electromagnetic software (Ansys-HFSS), corresponding to the configuration shown in FIG. 1 , wherein antenna element 12 is made of a resistive sheet having a 25 Ohm per square sheet resistivity, for three different feeding mechanisms. Coplanar waveguide 14 and antenna element 12 are both disposed on top of a 280ร174 mm glass substrate of 0.55-mm thickness, having a relative permittivity of 7 and a loss tangent of 0.01. In this configuration, antenna-feeding system 10 is intended to operate at a frequency of approximately 5.25 GHz.
[0043] The results of a first feeding mechanism, corresponding to feeding coupling element 19 adapted to the topology of antenna element 12 , are shown in curve 24 , represented in FIG. 2 by a solid line with a circle marker. These results show that at 5.25 GHz frequency, the radiation efficiency of antenna-feeding system 10 is about 70%.
[0044] The results of a second feeding mechanism, corresponding to a feeding coupling element overlapping, but not adapted, to the topology of antenna element 12 , are shown in curve 26 , represented in FIG. 2 by a dot-dashed line with a triangle marker. These results show that at 5.25 GHz frequency, the radiation efficiency of antenna-feeding system 10 is approximately 63%. In this configuration, the feeding coupling element has the same rectangular shape as feed line 20 , and acts as an extension of feed line 20 , overlapping by 1 mm into antenna element 12 . These results show that at 5.25 GHz frequency, the radiation efficiency of the antenna-feeding system is approximately 63%.
[0045] The results of a third feeding mechanism, corresponding to a feed line 20 physically touching and electrically connected to second edge 18 of antenna element 12 , are shown in curve 28 , represented in FIG. 2 by a dashed line with a square marker. In this configuration, there is no feeding coupling element overlapping or adapted to the topology of antenna element 12 . These results show that at 5.25 GHz frequency, the radiation efficiency of the antenna-feeding system is approximately 46%. This configuration is representative of traditional design techniques to feed an antenna.
[0046] The results shown in FIG. 2 are indicative that an adaptive feeding coupling element 19 , overlapping antenna element 12 , results in a significantly higher radiation efficiency of resistive antenna-feeding system 10 , as compared to traditional feeding design techniques.
[0047] FIG. 3 shows a graph of antenna radiation efficiency, as a function of frequency, calculated by a well-known and commercially available electromagnetic software (Ansys-HFSS), corresponding to the configuration shown in FIG. 1 , wherein antenna element 12 is made of a resistive sheet, for different values of sheet resistivity. Coplanar waveguide 14 and antenna element 12 are both disposed on top of a 280ร174 mm glass substrate of 0.55-mm thickness, having a relative permittivity of 7 and a loss tangent of 0.01. In this configuration, antenna-feeding system 10 is intended to operate at a frequency of approximately 5.25 GHz.
[0048] Particularly with reference to FIG. 3 , a dotted line with a solid-circle marker curve 32 ; a solid line with an empty-circle marker curve 34 ; a dot-dashed line with a triangle marker curve 36 ; and a dashed line with a square marker curve 38 , correspond to the simulated radiation efficiency of antenna-feeding system 10 made of a material having a 10 ฮผOhm per square sheet resistivity, a 25-Ohm per square sheet resistivity, a 36-Ohm per square sheet resistivity, and a 50-Ohm per square sheet resistivity, respectively. This graph shows how the radiation efficiency of antenna system 10 increases as the sheet resistivity decreases. Also, FIG. 3 shows that the radiation efficiency of antenna system 10 is significantly larger (above 80%) when a material having a sheet resistivity of 10 ฮผOhm per square is used. This value of sheet resistivity is common for highly conductive materials, such as copper and silver, at the range of frequency values indicated in FIG. 3 . However, for certain applications, including those involving tablets, laptop computers or mobile phones, the use of a resistive sheet material of up to 50-Ohm per square sheet resistivity is required or preferred over the use of a highly conductive material. In these cases, the use of antenna-feeding systems with improved radiation efficiency may be the only way to practically implement a solution.
[0049] FIG. 4 shows another exemplary configuration of an antenna-feeding system in accordance with aspects an embodiment of the present invention, comprising two identical, semi-elliptical antenna elements 12 a and 12 b , a coplanar waveguide 14 , and two semi-elliptical feeding coupling elements 19 a and 19 b . Antenna elements 12 a and 12 b are both disposed on top of a 280ร174 mm glass substrate 40 of 0.55-mm thickness, having a relative permittivity of 7 and a loss tangent of 0.01. Coplanar waveguide 14 and feeding coupling elements 19 a and 19 b are formed by thin layers of conductive material disposed on a rigid or flexible substrate 23 , as well known to those skilled in the art.
[0050] In this configuration, the ground plane structure of coplanar waveguide 14 is formed by two rectangular thin layers of a conductive material 16 a and 16 b having different dimensions with respect to one another, i.e., 10ร14 mm and 10ร30 mm, respectively. Antenna elements 12 a and 12 b are disposed on glass substrate 40 such that midpoints 42 a and 42 b along the semi-elliptical edge of antenna elements 12 a and 12 b , equidistant from the ends of linear edges 15 a and 15 b , respectively, are positioned at the same edge along the width of glass substrate 40 . Feeding coupling elements 19 a and 19 b overlap antenna elements 12 a and 12 b , respectively, such that midpoints 42 a and 42 b along the semi-elliptical edge of antenna elements 12 a and 12 b , equidistant from the ends of linear edge 15 a and 15 b , respectively, are positioned at a distance of approximately 1 mm from linear edges 22 a and 22 b of feeding coupling elements 19 a and 19 b . The semi-elliptical edge of antenna elements 12 a and 12 b is elliptically shaped according to an ellipse with a major axis of approximately 9.2 mm, parallel to linear edge 15 a , 15 b and a major-to-minor axes ratio of 1.15.
[0051] Additionally, rectangular feed line 20 , having dimensions of 3ร10.7 mm splits into two rectangular sections 20 a and 20 b , with dimensions of 0.5ร9.1 mm and 0.5ร22.5 mm, respectively, to allow feeding coupling element 19 a , 19 b to physically and electrically connect to antenna element 12 a , 12 b , respectively. Feed line 20 is generally parallel to, and separated 0.5 mm from, an edge of ground plane sections 16 a and 16 b . Likewise, sections 20 a and 20 b are generally parallel to, and separated about 0.2 mm from, an edge of ground plane sections 16 a and 16 b . A choice of a different length for sections 20 a and 20 b of feed line 20 may help in designing an antenna capable of operating at more than one frequency band. The specific frequency bands of operation may be adjusted by varying the lengths of sections 20 a and 20 b of feed line 20 . In this configuration, a first intended frequency band of operation ranges approximately between 2.2 GHz and 2.5 GHz, and a second intended frequency band of operation ranges about between 5 GHz and 5.8 GHz.
[0052] Those skilled in the art will recognize that the configuration shown in FIG. 4 may be implemented with sections 20 a and 20 b having the same length. Likewise, ground plane sections 16 a and 16 b may have identical dimensions. Additionally, an input impedance performance of antenna elements 12 a and 12 b may be modified by varying the separation between sections 20 a and 20 b and ground plane sections 16 a and 16 b.
[0053] In certain applications, the location of antenna element 12 on an electronic device, such as a touchscreen, is strictly limited to a small area on a given layer of such device. The use of a flexible structure such as a flexible printed circuit (FPC) offers an option to reduce the overall size occupied by antenna-feeding system 10 on the space-limited layer of the electronic device. FIG. 5 shows another exemplary configuration in accordance with certain aspects of an embodiment in which a coplanar waveguide feeding is implemented on a flexible substrate 50 , such as polyimide, as is well known to those skilled in the art. The ground plane structure 16 a , 16 b and feed line 20 of coplanar waveguide 14 as well as feeding coupling element 19 are formed by thin layers of conductive material all disposed on flexible substrate 50 to facilitate a spatial arrangement such that the region of layer 52 occupied by antenna-feeding system 10 is approximately the same area within the perimeter defined by the edges of antenna element 12 . In other words, flexible substrate 50 can be bent in a way that only feeding coupling element 19 is disposed on layer 52 . Alternatively, antenna element 12 can also be implemented on flexible substrate 50 such that the entire antenna-feeding system 10 is disposed on flexible substrate 50 . This may be advantageous for certain applications in terms of antenna performance or a practical, low cost implementation.
[0054] FIG. 6 shows an electronic device 60 implemented on a flexible substrate 62 . Likewise, a terminal 64 for electrically connecting to an external electronic device can be implemented on flexible substrate 62 at different locations and in multiple numbers. Furthermore, a conductive trace 66 of selectable length, width, and thickness can be implemented on flexible substrate 62 at different locations and in multiple numbers. Therefore, in another exemplary configuration, the entire antenna-feeding system 10 in addition to a transmission line to electrically connect antenna-feeding system 10 to a radio module or electronic system, including impedance matching circuitry, an amplifier, an RF filter, a receiver, a transmitter, a transceiver (transmitter and receiver) or a signal processing module may also be implemented on flexible substrate 62 . Even further, a radio module or electronic system, including impedance matching circuitry, an amplifier, an RF filter, a receiver, a transmitter, a transceiver (transmitter and receiver) or a signal processing module may be implemented on flexible substrate 62 along with antenna-feeding system 10 and one or more transmission lines.
[0055] In yet another exemplary configuration in accordance with certain aspects of an embodiment, FIG. 7 shows a plurality of antennas disposed on a multiple layer structure 70 , in which a screen layer 72 , such as a touch screen layer implemented on an electronic device, is disposed on top of a first layer 74 . Likewise, first layer 74 is disposed on top of a second layer 76 , and second layer 76 is disposed on top of a third layer 78 . Each of these layers 72 , 74 , 76 , 78 may be made of a flexible or rigid dielectric substrate that may, but does not need to, be the same dielectric substrate used to make any other of said layers. One or more antennas 84 may be disposed on first layer 74 . Similarly, one or more antennas 86 and 88 may be disposed on second layer 76 and third layer 78 , respectively. Therefore, a plurality of antennas may be disposed on any layer 74 , 76 , 78 of multilayer structure 70 to operate simultaneously. As a result, one antenna-feeding system 10 may be disposed on any layer of multilayer structure 70 . Moreover, one antenna-feeding system 10 may be used to directly feed one antenna and at the same time electromagnetically couple to feed one or more antennas disposed on the same or at a different layer of multilayer structure 70 . Alternatively, more than one antenna-feeding system 10 may be used on one or more layers of multilayer structure 70 .
[0056] Although in the configuration shown in FIG. 7 touch screen layer 72 is positioned above all other layers 74 , 76 , 78 of multilayer structure 70 , those skilled in the art will recognize that other configurations of multilayer structure 70 are possible, specifically wherein touch screen layer 72 is positioned below all other layers 74 , 76 , 78 or in between any two of said layers.
[0057] Each of the antennas 84 , 86 , 88 can be used for the same or a different application and can be implemented by means of a highly conductive material, such as copper or silver, or a resistive material, such as Indium tin-oxide. FIG. 7 shows only in an illustrative manner some of the potential applications of antennas 84 disposed on layer 74 , for instance, Wi-Fi multiple-input multiple-output (MIMO) applications. Similarly, antennas 86 , disposed on layer 76 , may be used for cellular 3 G or 4 G applications, and antennas 88 , disposed on layer 78 may be used for wireless energy harvesting applications. Those skilled in the art will recognize that many other antenna applications are possible for antennas 84 , 86 , 88 .
[0058] Typically, for a touch screen layer 72 , an array of touch sensors 82 , made of a resistive material, are disposed on and throughout most of the surface of layer 72 . Touch sensors 82 may block or obstruct radio signals transmitted or received by antennas 84 , 86 , 88 , resulting in a degradation of performance of said antennas. An option to overcome such performance degradation is to create a geometrical pattern in touch screen layer 72 by rearranging touch sensors 82 or alternatively deleting a portion of the resistive material disposed on touch screen layer 72 , such that the performance of touch screen layer 72 is not significantly affected, to implement a frequency selective surface on touch screen layer 72 . A properly designed frequency selective surface will allow radio signals transmitted or received by antennas 84 , 86 , 88 to propagate through layer 72 without severely affecting the performance of the antennas.
[0059] In general, each layer 72 , 74 , 76 , 78 is electrically isolated from one another. However, the typical proximity between any two of the layers is on the order of several hundred microns, resulting in a potentially strong electromagnetic coupling between conductive or resistive elements disposed on any of the layers. Therefore, a number, location, distribution, and topology of antennas 84 , 86 , 88 may depend on each specific application of the antennas, the material used to make the antennas, and the structures surrounding the antennas. Accordingly, one or more antenna-feeding systems may be used on one or more layers of multilayer structure 70 .
[0060] Those skilled in the art will realize that other methods of implementing feed line 20 are possible. Thus, in addition to using a coplanar waveguide, a microstrip line, a coplanar stripline, a coaxial cable and its associated transition sections to planar structures, a slot, and other types of transmission lines known in the prior art may be used without departing from the spirit and scope of the invention. Likewise, those skilled in the art will recognize that feeding coupling element 19 may be implemented by using conductive adhesive, soldering a conductive terminal, or other types of electromagnetically-coupled feeding elements known in the prior art.
[0061] Alternatively, other forms of the configurations described herein may include a resistive sheet antenna having a topology with at least one smooth edge and at least one smooth corner. In another configuration, the topology of the resistive sheet antenna may be configured to reduce electromagnetic coupling to other resistive or conductive materials. In yet another configuration, the topology of the resistive sheet antenna may be configured to have a shape as wide as possible, to have at least one region wide enough to avoid RF current โpinch points.โ Likewise, in any of the configurations described herein, the antenna-feeding system may operate in an elliptical polarization, including a generally linear polarization and a generally circular polarization; in a single frequency band or multiple frequency bands; and as part of a single, diversity, multiple input multiple output (MIMO), reconfigurable or beam forming network system.
[0062] Likewise, those skilled in the art will realize that one or more components described in the different configurations of antenna-feeding system 10 may be implemented by means of a resistive film comprising a metal oxide compound, such as tin oxide, disposed on a flexible or rigid substrate, or by application of a resistive coating directly to a flexible or rigid substrate or to a thin layer of a substrate such as polyethylene terephthalate or polyimide to be disposed on a flexible or rigid substrate.
[0063] Regarding each of the above-described configurations, a method as depicted in FIG. 8 for designing an adaptive feeding topology to feed a resistive sheet antenna, and for setting up the feeding system dimensional and operational parameters, may be performed according to the following:
[0064] 1. At step 810 , determining an initial topology design of the antenna feeding coupling element. In particular, the area of the initial topology of the antenna feeding coupling element, in which the RF currents of interest flow, must be smaller than the area defined by the periphery of the topology of the resistive sheet antenna.
[0065] 2. Next, at step 820 , coupling the antenna feeding coupling element to the resistive sheet antenna to enable the excitation of RF currents, while avoiding RF current โhot spotsโ and RF current โpinch points,โ by increasing the uniform distribution of RF currents flowing over the resistive sheet, at the frequencies of interest.
[0066] 3. Next, at step 830 , adapting the topology of the antenna feeding coupling element, through alternative topology designs, to enable the excitation of RF currents that flow as uniformly as possible over the resistive sheet antenna, to reduce RF current โhot spotsโ and RF current โpinch points.โ This may include the implementation of one or more of the following design considerations: increasing the coupling area of the feeding coupling element and the resistive sheet antenna wherein the currents flow, reducing the sheet resistivity of the resistive sheet, and smoothing out the edges and avoiding sharp corners of the feeding topology in regions wherein the currents flow.
[0067] 4. Next, at step 840 , selecting the feeding topology most suitable to transition from the antenna feeding coupling element to the transmission line to be used for the intended application of the antenna.
[0068] 5. Next, at step 850 , reducing as much as possible any electromagnetic coupling between the antenna feeding system and other materials within a radius of two wavelengths at the lowest frequency of operation of the antenna in the medium wherein the antenna is intended to operate. This may include reconfiguring the topology of the antenna feeding system.
[0069] 6. Next at step 860 , repeating steps 810 to 850 , if necessary, for other topologies of the antenna feeding system.
[0070] 7. Last, at step 870 , selecting the topology of the antenna feeding system most suitable for the intended application of the adaptive feeding-resistive sheet antenna, in terms of performance or other predetermined criteria.
[0071] Those of ordinary skill in the art will recognize that the steps above indicated can be correspondingly adjusted for specific configurations and other constraints, including operating frequency band and bandwidth, radiation gain, polarization, radiation efficiency, input impedance matching, operational conditions, surrounding environment, available area and location for implementation of the antenna and adaptive feeding system, method of antenna feeding, and type of transmission line used for a given application.
[0072] Preferably, the uniformity of RF currents flowing over the resistive sheet, RF current โhot spots,โ RF current โpinch points,โ the electromagnetic coupling between two materials, and other antenna performance parameters, including but not limited to electromagnetic fields, radiation efficiency, currents, radiation gain, input impedance, and polarization are determined by means of a computer-assisted simulation tool and electromagnetic simulation software, such as Ansys-HFSS commercial software or other methods well-known by those skilled in the art.
[0073] Most preferably, a data processing and decision making algorithm may be implemented to analyze parameters or calculate a figure of merit of the adaptive feeding system performance, including but not limited to electromagnetic fields, transmission efficiency, radiation efficiency, currents, and input impedance, to support or guide the adaptive antenna feeding design process as described herein, as those skilled in the art will realize. Alternatively, a figure of merit of the antenna performance, including but not limited to electromagnetic fields, radiation efficiency, currents, radiation gain, input impedance, and polarization, may be determined to support or guide the adaptive antenna feeding design process as described herein, as those skilled in the art will realize.
[0074] The various embodiments have been described herein in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. Any embodiment herein disclosed may include one or more aspects of the other embodiments. The exemplary embodiments were described to explain some of the principles of the present invention so that others skilled in the art may practice the invention. Obviously, many modifications and variations of the invention are possible in light of the above teachings. The present invention may be practiced otherwise than as specifically described within the scope of the appended claims and their legal equivalents.
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Disclosed is an antenna feeding system and method to optimize the design of the feeding system to feed an antenna made of a resistive sheet. The system and method are operative to design a topology of the antenna feeding system to adapt to a topology of the resistive sheet antenna to mitigate the adverse effects caused by the inherent losses of resistive sheets while operating as antennas. The system is designed to reduce a convergence of radiofrequency currents that may create a localized high density current concentration, such as โhot spotsโ and โpinch points,โ on the resistive sheet, by a sufficient extent so as to prevent power losses that substantially decrease the radiation efficiency of the antenna as compared with feeding systems designed using traditional design techniques.
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FIELD
[0001] The present invention is directed toward the field of horizontal spacers for glass blocks. In particular, the present invention relates to horizontal spacers for positioning on rectangular and non-rectangular glass blocks, which enables non-rectangular glass blocks to be connected to adjacent non-rectangular or rectangular glass blocks such that any configuration of wall may be formed using such blocks.
BACKGROUND OF THE INVENTION
[0002] Glass blocks are widely used in modern architecture and in the construction industry for building things such as walls, partitions and shower walls. For rectangular glass blocks, the interface surface between vertical stacks of such blocks is rectangular. The interface surface for non-rectangular glass blocks have edges which form angles of 22ยฝ degrees, 45 degrees, 90 degrees, and radius blocks having curved outer surfaces. Rectangular and non-rectangular glass blocks have a raised peripheral flange formed around the external faces of the block and an intermediate raised peripheral flange disposed proximate the midpoint of the internal periphery of the glass block.
[0003] When assembling a glass block wall with mortar a high degree of skill is required, as the weight of the blocks on the mortar make it difficult to obtain evenly spaced horizontal or vertical course arrangements between each row of blocks. Also, the blocks tend to be non-porous and as a result do not form a strong bond with the mortar. In order to solve these problems, many glass block assemblies exist which use generally rigid spacing, reinforcement and tying devices for the blocks. However, many of these assemblies have a large number of parts, and/or require a skilled laborer to assemble the glass block wall.
[0004] As a consequence, there is a need for a horizontal spacer for non-rectangular glass blocks that not only enables the same size joints to be easily obtained, but also allows the joints to be adjusted. Further, there is a need for a horizontal spacer for non-rectangular glass blocks that has a minimal number of parts such that the glass block wall may be constructed quickly and easily by an unskilled laborer, thereby reducing the cost. Accordingly, it is an object of the invention to provide a horizontal spacer for positioning on rectangular or non-rectangular glass blocks, which may connect to an adjacent horizontal spacer from the present invention or with a rectangular glass block horizontal spacer.
SUMMARY OF THE INVENTION
[0005] The present invention provides a horizontal spacer for positioning on rectangular and non-rectangular glass blocks, which enables a connection to a spacer on an adjacent non-rectangular or rectangular glass block. The horizontal spacer comprises a main portion that is positioned between the peripheral edges of the top and/or bottom surfaces of the non-rectangular glass block and tabs, which extend from opposing sides of the main portions. Receiving holes are also located on opposing sides of the main portion. The tabs connect to other non-rectangular horizontal spacers by inserting the tabs into the receiving holes of the adjacent horizontal spacer. The tabs can also connect to a rectangular horizontal spacer by inserting the tabs directly into the spacer. The tabs extend perpendicularly from an edge of the main portion enabling a square connection to be made to an adjacent non-rectangular or rectangular horizontal spacer, such that any configuration of angled or curved glass wall can be installed with a reduced amount of time and effort. Further, the tabs allow for the spacing between the joints to be varied as well as for minor lateral adjustments.
[0006] The horizontal spacer preferably consists of two identical pieces. The main portion of each piece has holes and pegs, which connect the identical pieces together. Preferably, the tabs on one side of the main portion are diagonally opposite from the tabs on the other side, as are the receiving holes. Therefore, as the tabs are offset, two tabs and two receiving holes are located on opposing sides. Advantageously, parts are minimized as one piece of the horizontal spacer may be used for the first and last row, where a spacer of lesser thickness is required.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Further features and advantages of the invention will be apparent from the following detailed description, given by way of example, of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:
[0008] [0008]FIG. 1 is a perspective view of the horizontal spacer for use with radius glass blocks;
[0009] [0009]FIG. 2 is a perspective view of one half of the horizontal spacer for use with radius glass blocks;
[0010] [0010]FIG. 3 is a perspective view of a section of glass block wall constructed in accordance with the teachings of this invention using the horizontal spacer for radius glass blocks;
[0011] [0011]FIG. 4 is a top view of the horizontal spacer for use with 90-degree glass blocks;
[0012] [0012]FIG. 5 is a perspective view of one half of the horizontal spacer for use with 90-degree glass blocks;
[0013] [0013]FIG. 6 is a perspective view of the horizontal spacer for use with 90-degree glass blocks in use with adjacent rectangular glass blocks;
[0014] [0014]FIG. 7 is a perspective view of the horizontal spacer for use with 45-degree glass blocks;
[0015] [0015]FIG. 8 is a perspective view of one half of the horizontal spacer for use with 45 degree glass blocks; and
[0016] [0016]FIG. 9 is a perspective view of the horizontal spacer for use with 45-degree glass blocks in use with adjacent rectangular glass blocks.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring to FIG. 1, a perspective view of the horizontal spacer 18 for a radius glass block, such as the ARQUEยฎ block by Pittsburgh-Corning Company, is shown. Two identical main pieces 24 A and 24 B connect together to form the horizontal spacer 18 . Each main piece 24 A and 24 B includes elongated tabs 20 A and 20 B and receiving holes 22 A and 22 B. Preferably, tabs 20 A and receiving holes 22 B are adjacent on one side of each of the main pieces 24 A and 24 B and tabs 20 B and receiving holes 22 A are adjacent on the opposing side of each of the main pieces 24 A and 24 B. The tabs 20 A and 20 B extend perpendicularly from the main pieces 24 A and 24 B such that a square connection can be made to adjacent horizontal spacers. The tabs 20 A and 20 B include barbs 26 that aid in fitting the tabs into corresponding receiving holes of other horizontal spacers of the system. The tabs 20 A and 20 B are insertably adjustable into the receiving holes of adjacent rectangular or non-rectangular horizontal spacers and allow the spacing between the joints of adjacent glass blocks to be varied.
[0018] Referring to FIG. 2, a perspective view of main piece 24 B of the horizontal spacer 18 having a radius shape is shown. Main pieces 24 A and 24 B each include pegs 28 A and holes 28 B, such that the pegs 28 A of piece 24 A connect to holes 28 B on piece 24 B to connect the pieces together to form the horizontal spacer 18 as shown in FIG. 1.
[0019] Main pieces 24 A and 24 B may be used as the first or last row of spacers when constructing a glass block wall, where a spacer of lesser thickness is required.
[0020] Referring to FIG. 3 a perspective view of a glass block wall 10 is shown using radius horizontal spacers 18 with the radius blocks 14 and rectangular horizontal spacers 16 for straight blocks 12 . As shown in the drawing the main portion of the horizontal spacer 18 fits within the peripheral edges of the top of the radius glass block 14 . The type of glass blocks 12 used have a generally rectangular configuration with a raised peripheral flange formed around the external faces of the block and an intermediate raised peripheral flange disposed proximate the midpoint of the internal periphery of the glass block. Rectangular glass blocks are available in various sizes from various commercial sources such as Pittsburgh-Corning Company.
[0021] Referring to FIG. 4, a perspective view of the horizontal spacer 30 for a 90 degree glass block, such as the HEDRONยฎ corner block by Pittsburgh-Corning Company is shown. Two identical main pieces 38 A and 38 B connect together to form the horizontal spacer. Each main piece 38 A and 38 B includes elongated tabs 32 A and 32 B and receiving holes 34 A and 34 B. Preferably, tabs 32 A and receiving holes 34 B are adjacent on one side of each of the main pieces 38 A and 38 B and tabs 32 B and receiving holes 34 A are adjacent and on the opposing side of each of main pieces 38 A and 38 B. The tabs 32 A and 32 B extend perpendicularly from the main pieces 38 A and 38 B such that a square connection can be made to adjacent horizontal spacers. The tabs 32 A and 32 B include barbs 36 that aid in fitting the tabs into corresponding receiving holes of other horizontal spacers of the system. The tabs 32 A and 32 B are insertably adjustable into the receiving holes of adjacent rectangular or non-rectangular horizontal spacers and allow the spacing between the joints of adjacent glass blocks to be varied.
[0022] Referring to FIG. 5, a perspective view of main piece 38 B of the horizontal spacer 30 having a 90 degree shape is shown. Main pieces 38 A and 38 B each include pegs 40 A and holes 40 B, such that the pegs 40 A of piece 38 A connect to holes 40 B on piece 38 B to connect the pieces together to form the horizontal spacer 30 as shown in FIG. 4.
[0023] Main pieces 38 A and 38 B may be used as the first or last row of spacers when constructing a glass block wall, where a spacer of lesser thickness is required.
[0024] Referring to FIG. 6 a perspective view of a glass block wall 42 is shown using 90 degree horizontal spacer 30 with the 90 degree block 44 and rectangular horizontal spacers 16 for rectangular glass blocks 12 . As shown in the drawing the main portion of the horizontal spacer 30 fits within the peripheral edges of the top of the 90 degree glass block 44 .
[0025] Referring to FIG. 7, a perspective view of the horizontal spacer 46 for a 45 degree glass block, such as the TRIDRONยฎ 45 degree block units by Pittsburgh-Corning Company is shown. Referring to FIG. 8 a perspective view of main piece 52 B of the horizontal spacer 46 for a 45 degree block. Referring to FIGS. 7 and 8, two identical main pieces 52 A and 52 B connect together to form the horizontal spacer 46 . Each main piece 52 A and 52 B includes elongated tabs 48 A and 48 B and receiving holes 50 A and 50 B. Preferably, tabs 48 A and receiving holes 50 B are adjacent on one side of each of the main pieces 52 A and 52 B and tabs 48 B and receiving holes 50 A are adjacent on the opposing side of each of main pieces 52 A and 52 B. The tabs 48 A and 48 B extend perpendicularly from the main pieces 52 A and 52 B such that a square connection can be made to adjacent horizontal spacers. The tabs 48 A and 48 B include barbs 56 that aid in fitting the tabs into corresponding receiving holes of other horizontal spacers of the system. The tabs 48 A and 48 B are insertably adjustable into the receiving holes of adjacent rectangular or non-rectangular horizontal spacers and allow the spacing between the joints of adjacent glass blocks to be varied.
[0026] Main pieces 52 A and 52 B each include pegs 54 A and holes 54 B, such that the pegs 54 A of piece 52 A connect to holes 54 B on piece 52 B to connect the pieces together to form the horizontal spacer 46 as shown in FIG. 7.
[0027] Main pieces 52 A and 52 B may be used as the first or last row of spacers when constructing a glass block wall, where a spacer of lesser thickness is required.
[0028] Referring to FIG. 9 a perspective view of a glass block wall 56 is shown using a 45 degree horizontal spacer 46 with a 45 degree block 54 and rectangular horizontal spacers 16 for rectangular glass blocks 12 . As shown in the drawing the main portion of the horizontal spacer 18 fits within the peripheral edges of the top of the radius glass block 14 .
[0029] The three examples of horizontal spacers shown are radius, 45 degree, and 90 degree; however, any shape of horizontal spacer can be formed to accommodate any rectangular or non-rectangular glass block. Further, although two tabs and two receiving holes are described, more or less than two tabs or receiving holes may be used.
[0030] Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.
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This application discloses a horizontal spacer for rectangular and non-rectangular glass blocks, which enables non-rectangular glass blocks to be connected to adjacent nonrectangular or rectangular glass blocks such that any configuration of wall may be formed using such blocks. The horizontal spacer has elongated tabs and receiving holes which extend from opposing sides. The elongated tabs engage the receiving holes of adjacent horizontal spacers.
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FIELD OF THE INVENTION
[0001] The present invention relates to the mediation of subsurface soil and ground water contamination. More specifically, it relates to the injection of dried algae and other mixtures for the dechlorination of soil and ground water contaminated with chlorinated solids.
BACKGROUND OF THE INVENTION
[0002] This invention aids in the remediation of environmental contaminants in subsurface soils and groundwater via the stimulation of aerobic processes. More particularly, this invention relates to remediation processes involving emplacement of solid-phase or aqueous-phase treatment agents with soil fracturing technology. Emplacement of micro-blue green algae and or species of seaweed as electron donors for microorganisms that carry out reductive dechlorination of chlorinated solvent source areas or plumes is illustrative of the invention.
[0003] Spirulina is the common name for human and animal food supplements produced primarily from two species of cyanobacteria (also known as blue-green algae): Arthrospira platensis and Arthrospira maxima. These and other Arthrospira species were once classified in the genus Spirulina. There is now agreement that they are distinct genera, and that the food species belong to Arthrospira; nonetheless, the older term Spirulina remains the popular name. Spirulina is cultivated around the world, and is used as a human dietary supplement as well as a whole food and is available in tablet, flake, and powder form. It is also used as a feed supplement in the aquaculture, aquarium, and poultry industries.
[0004] Spirulina is rich in gamma-linolenic acid (GLA), and also provides alpha-linolenic acid (ALA), linoleic acid (LA), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA). Spirulina also contains vitamin B 1, B2, B3, B6, B9, B12, vitamin C, vitamin D, and vitamin E.
[0005] Other species of Cyanobacteria, like Aphanizomenon flos - aquae and Chlorella share similar nutritional components including omega 3 and 6 fatty acids as well as a wide variety of vitamins, and minerals. Vitamins A, B1(Thiamine), B2 (Riboflavin), B3(Niacin), B6 (Pyrodoxine), B 12 (Cyanocobalamin), and vitamins C and E are present in high concentrations along with many essential amino acids. The high concentrations of many of these valuable nutrients provide optimal living conditions for the anaerobic processes responsible for the remediation of contaminated soil and groundwater sites.
[0006] Similar to Cyanobacteria, various species of Seaweed including Dulse, Nori, and Kelp contain substantial nutrients beneficial to anaerobic processes. Available in both flake and powder form, Seaweed has been an essential food source for years, used in sushi, chips, seasoning, and even as a dietary supplement for its high nutritional value. Along with a plethora of vitamins and minerals, seaweeds have long been known for their impressive chemical composition comprised of fatty acids, carbohydrates, and proteins. Their concentrations of vitamins B2, B12 in particular make seaweed, along with blue-green algae an excellent option for environmental remediation. Taken in totality, the use of seaweed and or cyanobacteria offer the micronutrients and volitile fatty acid precursors that will provide long-term production of organic hydrogen necessary for reductive dechlorination of chlorinated solvents in groundwater and soils.
[0007] Chlorinated solvents are the most common class of ground water contaminants at hazardous waste sites in the U.S. In a list of the top 25 most frequently detected contaminants at such sites, the Agency for Toxic Substances and Disease Registry (ATSDR) found that 10 of the top 20, including two of the top three, were chlorinated solvents or their degradation products. National Research Council, Alternatives for Ground Water Cleanup (National Academy Press, Washington, D.C. 1994). In fact, the same survey found that the most common contaminant, trichloroethylene (TCE), is present in more than 40% of National Priority List sites. The remediation of ground water contaminated by these compounds often presents unique obstacles related to their inherent characteristics, including hydrophobicity and high density. Many commercial process utilize raw vegetable oils and emulsions which co-elute the targeted solvents within the treatment liquid masking the presence of the compound targeted for treatment rather than stimulating the mineralization of said compound.
[0008] Overcoming these obstacles often demands innovation and an interdisciplinary approach that integrates hydrology, geology, chemistry, microbiology, and economics. In particular, an innovative approach has been conceived, and is described herein, to harness recent advances in the understanding of biodegradation processes involving chlorinated solvents for remediating residual source areas, or for cutting off dissolved plumes, by emplacing solid-phase or aqueous-phase treatment agents into a variety of soil types throughout much larger volumes of the subsurface than has been possible using conventional methods. One embodiment of this innovation involves delivering micro-blue green algae, as an electron donor, into induced fractures in low permeability soils to create and maintain nutrient-rich anaerobic conditions that will promote the long-term bioremediation of a chlorinated solvent or other dense nonaqueous phase liquid (DNAPL) source. A second embodiment of this invention includes the addition of a zero-valent metal with the dried micro-blue green algae such that the dissolved chlorinated solvents are both biotically and abiotically degraded.
[0009] Natural attenuation of chlorinated solvents by reductive dechlorination often occurs at sites where an electron donor (food source or substrate for microbes) is present along with the chlorinated solvent contamination. As dissolved oxygen and other electron acceptors become depleted some microbes are capable of using the chlorinated solvents as electron acceptors. For selected compounds such as chlorinated ethylenes sequential dechlorination to a harmless byproduct ethylene can be achieved under favorable environmental conditions (EPA/600/R-98/128 September 1998).
[0010] In recent years efforts have been made to produce this anaerobic treatment effect by injection of electron donor into the subsurface. An overview of these technologies can be reviewed in the EPA document Engineered Approaches to In Situ Bioremediation of Chlorinated Solvents: Fundamentals and Field Applications (EPA 542-R-00-008 July 2000). Other inorganic and organic compounds can be degraded or immobilized under anaerobic conditions including selected toxic metals, nitrate, and MTBE. For sites that do not have sufficient amounts of natural electron donors to drive anaerobic natural attenuation, injection of microbial substrates has proven to be a cost-effective treatment or plume migration control measure. The microbial substrates can be injected into the contaminant source area where residual contamination is adsorbed onto soils or injected in a line across a ground water contaminant plume to form a permeable reactive wall to prevent further contaminant migration.
[0011] A wide variety of sugars, alcohols, organic acids, and even molecular hydrogen have been used successfully as electron donors to enhance anaerobic biotransformation processes. Most of these compounds are rapidly consumed after injection and must be replaced by either continuous low concentration delivery systems or with frequent batch additions of additive solution. Contaminant source areas can not be effectively removed or even precisely located for many ground water contaminant plumes. The presence of residual chlorinated solvents adsorbed onto soils or present as dense non-aqueous phase product (DNAPL) serves as an example of persistent ground water plume source areas that can last for many decades. These persistent contaminant source areas continue to contaminate ground water for many years such that continuous operation of recirculation systems or frequent substrate injections can be very costly over the life of a project. Long-term injection of substrates into wells or infiltration galleries often leads to severe bacterial fouling problems adding to project operation and maintenance costs.
[0012] Recent interest has developed in the use of materials that slowly biodegrade or slowly release organic matter into ground water over time. A variety of vegetable oils have been demonstrated to be effective electron donors to stimulate anaerobic biodegradation. Although edible oils such as soybean oil have a much lower viscosity than a semisolid product, distribution in saturated soils is difficult. Soybean oil has a viscosity approximately 80 times higher than water, which results in multiphase fluid flow and potential oil blockage of soil porosity. Injection of pure oil or large droplets of emulsified oil blocks soil pores producing treatment zones that are ineffective because they prevent free flow of ground water through the oil treated area. Injection of pure soybean oil into porous soil media has been shown to reduce water permeability by up to 100%.
[0013] In addition to slowly biodegradable hydrogen sources, soil and groundwater remediation process that utilize zero-valent metals have been applied with varying success. In the second embodiment of the invention the addition of zero-valent metals to the micro-blue green algae allows for maintained reducing conditions resulting in greater longevity of the reactive metal surface. Zero-valent metal particles have been proven to effectively degrade halogenated solvents. For example, the mechanism and reaction rates of which iron reduces chlorinated aliphatics has been studied extensively due to iron's low cost and low toxicity.
[0014] Additionally, the pathways of the dehalogenation of DNAPL's such as TCE have been proposed. TCE undergoes hydrogenolysis where the replacement of each of the three chlorines occurs sequentially. TCE reduces to cis-1,2-dichloroethene, trans-1,2-dichloroethene, and 1,1-dichloroethene. These intermediates in turn reduce to ethene and ethane.
SUMMARY OF THE INVENTION
[0015] To overcome the foregoing problems, the present invention utilizes dried micro-blue green algae and dried micro-seaweed species like non or dulse. Micro-blue green algae are rapid growing aquatic organisms that take their energy directly from the sun and the minerals in water, they contain amino acid proteins, organic vitamin B12, iron and essential fatty acids including gamma-linolenic acid (GLA), alpha-linolenic acid (ALA), linoleic acid (LA), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA). These organisms also are highly alkalizing, as a consequence their addition counter-acts the natural production of acids produced by-way of anaerobic dechlorinization. These organisms are commercially available dried, in large quantities. The dechlorination process may be further accelerated by the addition of a zero-valent metal powder to the dried micro-blue green algae. When emplaced in groundwater and soils impacted by chlorinated solvents the micro-blue green algae offer all the needed components for effective and rapid remediation of compounds such as tetrachloroethane, tetrachloroethene, trichloroethane, trichloroethene, carbon tetrachloride and their anaerobic daughter products.
[0016] The actions of the algae or seaweeds on the subsurface may be further enhanced with the inclusion of zero-valent metal particles. Alone, or in a mixture, the micro-blue green algae is particularly suited for dehalogenation of solvents including, but not limited to, tetrachloroethane, tetrachloroethene, trichloroethane, trichloroethene, carbon tetrachloride and their anaerobic daughter products. The present invention achieves accelerated dechlorination of soil and ground water contaminated with chlorinated solvents by stimulating anaerobic microorganisms and thus increasing the rate of biological mineralization of the solvents.
[0017] More specifically the invention comprises a method for accelerating biotic dechlorination of ground water and soils provided by the steps of first injecting into the ground water and soils by way of temporary rods or permanent wells a mixture containing a predetermined mass of micro blue-green algae under pressure. Next, a mixture containing zero valent metal particles is injected to react with the dissolved chlorinated solvents. A second mixture containing zero valent metal particles is then injected so that the corrosion of the metal particles results in the elevation of the bulk PH of the surrounding ground water. Finally, micro blue-green algae is again injected into the ground water and soils with an oxygen scavenger to remove oxygen and ensure that the subsurface environment is reductive. All injections of materials are done in such a matter as to ensure there dispersion into the subsurface. Alternately, a simple single step method of employing the invention is injecting a solution of zero valent iron, blue-green algae or seaweed, and sodium sulfite into the subsurface using a pump.
[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 description and should not be regarded as limiting.
[0019] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods, and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] One embodiment of the present invention is carried out in the following steps.
[0021] Step 1: Subsurface Pathway Development
[0022] A gas is delivered to the subsurface as follows. Injection points are advanced via traditional direct push technology using injection rods or may be permanently installed injection wells. The gas is introduced at approximately 175 psi such that delivery pathways and voids are established. Pathway development is verified by observing a substantial pressure drop at the surface monitoring point. The gas is used so as not to introduce oxygen into an environment targeted for anaerobic processes.
[0023] Step 2: Sodium Sulfite and Blue-Green Algae OR Sodium Sulfite and Seaweed
[0024] Next a solution of sodium sulfite and blue-green algae is immediately injected into the subsurface fractures and voids that were developed during the gas injection step. Sodium sulfite acts as an oxygen scavenger, iron reducer, and sulfate source. As an oxygen scavenger, the sodium sulfite prevents the oxidation of the later-injected ZVI (Zero Valent Iron) by the dissolved oxygen while promoting anaerobic conditions that are favorable for the biodegradation of the DVOCs. Blue-green algae is an organic hydrogen donor, with necessary vitamins and minerals.
[0025] Step3: Zero Valent Iron (ZVI) Injection
[0026] Immediately following the sodium sulfite/blue-green algae solution injection, ZVI is added to an additional quantity of the blue-green algae solution and the colloidal suspension is injected to reduce concentrations of dissolved-phase CVOCs while providing for rapidly generated hydrogen for the microbial stimulation.
[0027] Step 4: Post Liquid Injection-Gas Injection
[0028] The injection lines are cleared of liquids by a second gas injection and all injectants are forced into the created formation and upward into the vadose zone. Once the injection cycle is complete, the injection point is temporarily capped to allow for the pressurized subsurface to accept the injectants. Once back-pressure diminishes, the injection rods are extracted. Injection boring locations are then sealed with bentonite or sand to prevent short-circuiting from adjacent injection locations. The following table depicts an amount of injectants that could be used in this embodiment.
[0000]
Component
Concentration
Blue Green Algae
โ5% by weight
Kelp
55% by weight
Iron
45% by weight
[0029] Another embodiment of the present invention is carried out in the following steps.
Step 1: Suspension Injection
[0030] A solution of zero-valent iron, blue-green algae (or seaweed) and sodium sulfite is injected into the subsurface using a pump. The following table depicts an amount of injectants that could be used in this embodiment.
[0000]
Component
Concentration
Blue Green Algae
45% by weight
Iron
55% by weight
[0031] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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The induction of reducing conditions and stimulating anaerobic process through the addition of dried micro-blue green algae ( Spirulina, Arthorospira Platensis, Arthrospria Maxima, Aphanizomen flos - aquae, and chlorella ) and seaweed (Dulse, Nori, and Kelp) to accomplish accelerated dechlorinization of soil and groundwater contaminated with chlorinated solvents and heavy metals.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a division of application Ser. No. 10/122,424 filed Apr. 12, 2002 now U.S. Pat. No. 6,883,611. The disclosure of this earlier application is incorporated herein in its entirety by this reference.
BACKGROUND
The present invention relates generally to operations performed in conjunction with subterranean wells and, in an embodiment described herein, more particularly provides a method of forming sealed wellbore junctions.
Many systems have been developed for connecting intersecting wellbores in a well. Unfortunately, these systems typically involve methods which unduly restrict access to one or both of the intersecting wellbores, restrict the flow of fluids, are very complex or require very sophisticated equipment to perform, are time-consuming in that they require a large number of trips into the well, do not provide secure attachment between casing in the parent wellbore and a liner in the branch wellbore and/or do not provide a high degree of sealing between the intersecting wellbores.
For example, some wellbore junction systems rely on cement alone to provide a seal between the interior of the wellbore junction and a formation surrounding the junction. In these systems, there is no attachment between the casing in the parent wellbore and the liner in the branch wellbore, other than that provided by the cement. These systems are acceptable in some circumstances, but it would be desirable in other circumstances to be able to provide more secure attachment between the tubulars in the intersecting wellbores, and to provide more effective sealing between the tubulars.
SUMMARY
In carrying out the principles of the present invention, in accordance with an embodiment thereof, a method of forming a wellbore junction is provided which both securely attaches tubulars in intersecting wellbores and effectively seals between the tubulars. The method is straightforward and convenient in its performance, does not unduly restrict flow or access through the junction, and does not require an inordinate number of trips into the well.
In one aspect of the invention, a method is provided for forming a wellbore junction which includes a step of expanding a member within a tubular structure positioned at an intersection of two wellbores. This expansion of the member may perform several functions. For example, the expanded member may secure an end of a tubular string which extends into a branch wellbore. The expanded member may also seal to the tubular string and/or to the tubular structure.
In another aspect of the invention, the tubular string may be installed in the branch wellbore through a window formed through the tubular structure. An engagement device on the tubular string engages the tubular structure to secure the tubular string to the tubular structure. For example, the engagement device may be a flange which is larger in size than the window of the tubular structure and is prevented from passing therethrough, thereby fixing the position of the tubular string relative to the tubular structure.
In yet another aspect of the invention, a whipstock may be used to drill the branch wellbore through the window in the tubular structure. Thereafter, the whipstock is used to install the tubular string in the branch wellbore. After installation of the tubular string, the whipstock may be retrieved from the parent wellbore, thereby permitting full bore access through the wellbore junction in the parent wellbore. The tubular string may be installed and the whipstock retrieved in only a single trip into the well using a unique tool string.
In still another aspect of the invention, the window may be formed in the tubular structure prior to cementing the tubular structure in the parent wellbore. To prevent cement flow through the window, a retrievable sleeve is used inside the tubular structure. After cementing, the sleeve is retrieved from within the tubular structure.
Various types of seals may be used between various elements of the wellbore junction. For example metal to metal seals may be used, or elements of the wellbore junction may be adhesively bonded to each other, etc.
These and other features, advantages, benefits and objects of the present invention will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the invention hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a method of forming a wellbore junction which embodies principles of the present invention and wherein a tubular structure has been cemented within a parent wellbore;
FIG. 2 is an enlarged cross-sectional view of the method wherein a branch wellbore has been drilled through the tubular structure utilizing a whipstock positioned in the tubular structure;
FIG. 3 is a cross-sectional view of the method wherein a tubular string is being installed in the branch wellbore;
FIG. 4 is an enlarged cross-sectional view of the method wherein a sleeve is being expanded within the tubular structure to thereby secure and seal the tubular string to the tubular structure;
FIG. 5 is a cross-sectional view taken along line 5 โ 5 of FIG. 4 , showing the sleeve expanded within the tubular structure;
FIGS. 6 & 7 are cross-sectional views of the sleeve in its radially compressed and expanded configurations, respectively;
FIGS. 8โ13 are cross-sectional views of a second method embodying principles of the present invention;
FIGS. 14โ17 are cross-sectional views of a third method embodying principles of the present invention;
FIGS. 18โ20 are cross-sectional views of a fourth method embodying principles of the present invention;
FIGS. 21โ25 are cross-sectional views of a fifth method embodying principles of the present invention;
FIGS. 26 & 27 are cross-sectional views of a sixth method embodying principles of the present invention;
FIGS. 28 & 29 are cross-sectional views of a seventh method embodying principles of the present invention;
FIG. 30 is a cross-sectional view of an eighth method embodying principles of the present invention; and
FIGS. 31โ35 are cross-sectional views of a ninth method embodying principles of the present invention.
DETAILED DESCRIPTION
Representatively illustrated in FIG. 1 is a method 10 which embodies principles of the present invention. In the following description of the method 10 and other apparatus and methods described herein, directional terms, such as โaboveโ, โbelowโ, โupperโ, โlowerโ, etc., are used only for convenience in referring to the accompanying drawings. Additionally, it is to be understood that the various embodiments of the present invention described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present invention.
As depicted in FIG. 1 , several steps of the method 10 have already been performed. A parent wellbore 12 has been drilled and a tubular structure 14 has been positioned in the parent wellbore. The tubular structure 14 is part of a casing string 16 used to line the parent wellbore 12 .
It should be understood that use of the terms โparent wellboreโ and โcasing stringโ herein are not to be taken as limiting the invention to the particular illustrated elements of the method 10 . The parent wellbore 12 could be any wellbore, such as a branch of another wellbore, and does not necessarily extend directly to the earth's surface. The casing string 16 could be any type of tubular string, such as a liner string, etc. The terms โcasing stringโ and โliner stringโ are used herein to indicate tubular strings of any type, such as segmented or unsegmented tubular strings, tubular strings made of any materials, including nonmetal materials, etc. Thus, the reader will appreciate that these and other descriptive terms used herein are merely for convenience in clearly explaining the illustrated embodiments of the invention, and are not used for limiting the scope of the invention.
The casing string 16 also includes two anchoring profiles 18 , 20 for purposes that are described below. The lower profile 20 may be an orienting latch profile, for example, a profile which serves to rotationally orient a device engaged therewith relative to the window 28 . The upper profile 18 may also be an orienting latch profile. Such orienting profiles are well known to those skilled in the art.
A tubular shield 22 is received within the casing string 16 , and seals 24 , 26 carried on the shield are positioned at an upper end of the tubular structure 14 and at a lower end of the anchoring profile 20 , respectively. The shield 22 is a relatively thin sleeve as depicted in FIG. 1 , but it could have other shapes and other configurations in keeping with the principles of the invention.
The shield 22 serves to prevent flow through a window 28 formed laterally through a sidewall of the tubular structure 14 . Specifically, the shield 22 prevents the flow of cement through the window 28 when the casing string 16 is cemented in the parent wellbore 12 . The shield 22 also prevents fouling of the lower profile 20 during the cementing operation, and the shield may be releasably engaged with the profile to secure it in position during the cementing operation and to enable it to be retrieved from the casing string 16 after the cementing operation, for example, by providing an appropriate convention latch on the shield.
The shield 22 prevents cement from flowing out to the window 28 when cement is pumped through the casing string 16 . Other means may be used external to the tubular structure 14 to prevent cement from flowing in to the window 28 , for example, an outer membrane, a fiberglass wrap about the tubular structure, a substance filling the window and any space between the window and the shield 22 , etc.
At this point it should be noted that the use of the terms โcementโ and โcementing operationโ herein are used to indicate any substance and any method of deploying that substance to fill the annular space between a tubular string and a wellbore, to seal between the tubular string and the wellbore and to secure the tubular string within the wellbore. Such substances may include, for example, various cementitious compositions, polymer compositions such as epoxies, foamed compositions, other types of materials, etc.
At the time the casing string 16 is positioned in the wellbore 12 , but prior to the cementing operation, the tubular structure 14 is rotationally oriented so that the window 28 faces in a direction of a desired branch wellbore to extend outwardly from the window. Thus, the tubular structure 14 is positioned at the future intersection between the parent wellbore 12 and the branch wellbore-to-be-drilled, with the window 28 facing in the direction of the future branch wellbore. The rotational orientation may be accomplished in any of a variety of ways, for example, by engaging a gyroscopic device with the upper profile 18 , by engaging a low side indicator with the shield 22 , etc. Such rotational orienting devices (gyroscope, low side indicator, etc.) are well known to those skilled in the art.
After the tubular structure 14 is positioned in the wellbore 12 with the window 28 facing in the proper direction, the casing string 16 is cemented in place in the wellbore. When the cementing operation is concluded, the shield 22 is retrieved from the casing string 16 .
Referring additionally now to FIG. 2 , an enlarged view of the method 10 is representatively illustrated wherein the shield 22 has been retrieved. A whipstock 30 or other type of deflection device has been installed in the tubular structure 14 by engaging keys, lugs or dogs 32 with the profile 20 , thereby releasably securing the whipstock in position and rotationally aligning an upper deflection surface 34 with the window 28 .
The whipstock 30 also includes an inner passage 36 and a profile 38 formed internally on the passage for retrieving the whipstock. Of course, other means for retrieving the whipstock 30 could be used, for example, a washover tool, a spear, an overshot, etc.
As depicted in FIG. 2 , one or more cutting devices, such as drill bits, etc., have been deflected off of the deflection surface 34 and through the window 28 to drill a branch wellbore 40 extending outwardly from the window. As discussed above, the term โbranch wellboreโ should not be taken as limiting the invention, since the wellbore 40 could be a parent of another wellbore, or could be another type of wellbore, etc.
Referring additionally now to FIG. 3 , the method 10 is representatively illustrated wherein a tubular string 42 has been installed in the branch wellbore 40 . The tubular string 42 may be made up substantially of liner or any other type of tubular material.
As depicted in FIG. 3 , the tubular string 42 includes an engagement device 44 for engaging the tubular structure 14 and securing an upper end of the tubular string thereto. The tubular string 42 also includes a flex or swivel joint 46 for enabling, or at least enhancing, deflection of the tubular string from the parent wellbore 12 into the branch wellbore 40 . Alternatively, or in addition, the swivel joint 46 permits rotation of an upper portion of the tubular string 42 relative to a lower portion of the tubular string in the rotational alignment step of the method 10 described below. The tubular string 42 is deflected off of the deflection surface 34 as it is conveyed downwardly attached to a tool string 48 .
The tool string 48 includes an anchor 50 for releasable engagement with the upper profile 18 , a running tool 52 for releasable attachment to the tubular string 42 , and a retrieval tool 54 for retrieving the whipstock 30 . The running tool 52 may include keys, lugs or dogs for engaging an internal profile (not shown) of the tubular string 42 . The retrieval tool 54 may include keys, lugs or dogs for engagement with the profile 38 of the whipstock 30 .
When the anchor 50 is engaged with the profile 18 , the tubular string 42 is rotationally aligned so that the engagement device 44 will properly engage the tubular structure 14 as further described below. In addition, the anchor 50 is preferably spaced apart from the engagement device 44 so that when the anchor is engaged with the profile 18 and a shoulder 56 formed on a tubing string 58 of the tool string 48 contacts the anchor, the engagement device is properly positioned in engagement with the tubular structure 14 .
Specifically, the tubing string 58 is slidably received within the anchor 50 . When the shoulder 56 contacts the anchor 50 , the engagement device 44 is a predetermined distance from the anchor. This distance between the anchor 50 and the engagement device 44 corresponds with another predetermined distance between the profile 18 and the tubular structure 14 . Thus, when the tubular string 42 is being conveyed into the branch wellbore 40 , the engagement device 44 will properly engage the tubular structure 14 as the shoulder 56 contacts the anchor 50 .
The running tool 52 may then be released from the tubular string 42 , the tool string 48 may be raised into the parent wellbore 12 , and then the retrieval tool 54 may be engaged with the profile 38 in the whipstock 30 to retrieve the whipstock from the parent wellbore. Note that the installation of the tubular string 42 and the retrieval of the whipstock 30 may thus be accomplished in a single trip into the well.
The engagement device 44 is depicted in FIG. 3 as a flange which extends outwardly from the upper end of the tubular string 42 . The engagement device 44 includes a backing plate or landing plate 60 which is received in an opening 62 formed through a sidewall of a guide structure 64 of the tubular structure 14 . Preferably, the opening 62 is complementarily shaped relative to the plate 60 , and this complementary engagement maintains the alignment between the tubular string 42 and the tubular structure 14 . For example, engagement between the plate 60 and the opening 62 supports the upper end of the tubular string 42 , so that an annular space exists about the upper end of the tubular string for later placement of cement therein.
The guide structure 64 is more clearly visible in the enlarged view of FIG. 2 . In this view it may also be seen that the opening 62 includes an elongated slot 66 at a lower end thereof. Preferably, the plate 60 includes a downwardly extending tab 68 (see FIG. 3 ) which engages the slot 66 and thereby prevents rotation of the engagement device 44 relative to the window 28 .
The engagement device 44 is larger in size than the window 28 , and so the engagement device prevents the tubular string 42 from being conveyed too far into the branch wellbore 40 . The engagement device 44 thus secures the upper end of the tubular string 42 relative to the tubular structure 14 . Of course, other types of engagement devices may be used in place of the illustrated flange and backing plate, for example, an orienting profile could be formed on the tubular structure and keys, dogs or lugs could be carried on the tubular string 42 for engagement therewith to orient and secure the tubular string relative to the tubular structure.
As depicted in FIG. 3 , the engagement device 44 carries a seal 70 thereon which circumscribes the opening 62 and sealingly engages the guide structure 64 . The guide structure 64 carries seals 72 , 74 thereon which sealingly engage above and below the window 28 . Thus, the tubular string 42 is sealed to the tubular structure 14 so that leakage therebetween is prevented. The seals 70 , 72 , 74 , or any of them, may be elastomer seals, non-elastomer seals, metal to metal seals, expanding seals, and/or seals created by adhesive bonding, such as by using epoxy or another adhesive.
Referring additionally now to FIG. 4 , an enlarged view is representatively illustrated of the method 10 after the tubular string 42 is installed in the branch wellbore 40 and the whipstock 30 is retrieved from the well. Note that an alternatively constructed engagement device 44 is illustrated in FIG. 4 which does not include the plate 60 . Instead, the flange portion of the engagement device 44 is received in the opening 62 and the engagement device is sealed to the tubular structure 14 about the window 28 using one or more seals 76 , 78 , 80 circumscribing the window. The seal 76 is an adhesive, the seal 78 is an o-ring and the seal 80 is a metal to metal seal.
To further secure the tubular string 42 to the tubular structure 14 , a member 82 is expanded within the tubular structure using an expansion device 84 . As depicted in FIG. 4 , the member 82 is a tubular sleeve having an opening 86 formed through a sidewall thereof. Of course, other expandable member shapes and configurations could be used in keeping with the principles of the invention.
The opening 86 is rotationally aligned with an internal flow passage 88 of the tubular string 42 , for example, by engaging the expansion device 84 with the upper profile 18 . Then, the expansion device 84 is actuated to displace a wedge or cone go upwardly through the member 82 , thereby expanding the member outwardly. Such outward expansion also outwardly displaces seals 92 , 94 , 96 , 98 , 100 carried on the member.
The seals 94 , 96 sealingly engage the guide structure 64 above and below the opening 62 . The seals 92 , 98 are metal to metal seals and sealingly engage the tubular structure 14 above and below the guide structure 64 . The seal 100 is an adhesive seal which circumscribes the passage 88 and sealingly engages the flange portion of the engagement device 44 . Of course, the seals 92 , 94 , 96 , 98 , 100 , or any of them, may be any type of seal, for example, elastomer, non-elastomer, metal to metal, adhesive, etc.
After the member 82 is expanded, the expansion device 84 is retrieved from the well and the tubular string 42 is cemented within the branch wellbore 40 . For example, a foamed composition may be injected into the annulus radially between the tubular string 42 and the branch wellbore 40 . The foamed composition could expand in the annulus to fill any voids therein, and could expand to fill any voids about the structure 14 in the wellbore 12 .
Note that the engagement device 44 is retained between the member 82 and the tubular structure 14 , thereby preventing upward and downward displacement of the tubular string 42 . In addition, where metal to metal seals are used, the expansion of the member 82 maintains a biasing force on these seals to maintain sealing engagement.
Referring additionally now to FIG. 5 , a partial cross-sectional view, taken along line 5 โ 5 of FIG. 4 is representatively illustrated. In this view, only the tubular string 42 , tubular structure 14 , guide structure 64 and expandable member 82 cross-sections are shown for clarity of illustration. From FIG. 5 , it may be more clearly appreciated how the engagement device 44 is received in the guide structure 64 , and how expansion of the member 82 secures the engagement device in the tubular structure 14 .
In addition, note that no separate seals are visible in FIG. 5 for sealing between the engagement device 44 and the tubular structure 14 or expansion member 82 . This is due to the fact that FIG. 5 illustrates an alternate sealing method wherein sealing between the engagement device 44 and each of the tubular structure 14 and expansion member 82 is accomplished by metal to metal contact between these elements.
Specifically, expansion of the member 82 causes it to press against an interior surface the engagement device 44 circumscribing the passage 88 , which in turn causes an exterior surface of the engagement device to press against an interior surface of the tubular structure 14 circumscribing the window 28 . This pressing of one element surface against another when the member 82 is expanded results in metal to metal seals being formed between the surfaces. However, as mentioned above, any type of seal may be used in keeping with the principles of the invention.
Referring additionally now to FIGS. 6 and 7 , the expansion member 82 is representatively illustrated in its radially compressed and radially expanded configurations, respectively. In FIG. 6 , it may be seen that the expansion member 82 in its radially compressed configuration has a circumferentially corrugated shape, that is, the member has a convoluted shape about its circumference. In FIG. 7 , the member 82 is radially expanded so that it attains a substantially cylindrical tubular shape, that is, it has a substantially circular cross-sectional shape.
Referring additionally now to FIGS. 8โ13 , another method 110 embodying principles of the invention is representatively illustrated. In the method 110 , a tubular structure 112 is interconnected in a casing string 114 and conveyed into a parent wellbore 116 . The tubular structure 112 preferably includes a tubular outer shield 118 outwardly overlying a window 120 formed through a sidewall of the tubular structure. The shield 118 is preferably made of a relatively easily drilled or milled material, such as aluminum.
The shield 118 prevents cement from flowing outwardly through the window 120 when the casing string 114 is cemented in the wellbore 116 . The shield 118 also transmits torque through the tubular structure 112 from above to below the window 120 , due to the fact that the shield is rotationally secured to the tubular structure above and below the window, for example, by castellated engagement between upper and lower ends of the shield and the tubular structure above and below the window, respectively.
The tubular structure 112 is rotationally aligned with a branch wellbore-to-be-drilled 122 , so that the window 120 faces in the radial direction of the desired branch wellbore. This rotational alignment may be accomplished, for example, by use of a conventional wireline-conveyed direction sensing tool (not shown) engaged with a key or keyway 124 having a known orientation relative to the window 120 . Other rotational alignment means may be used in keeping with the principles of the invention.
In FIG. 9 it may be seen that a work string 126 is used to convey a mill, drill or other cutting tool 128 , a whipstock or other deflection device 130 and an orienting latch or anchor 132 into the casing string 114 . The drill 128 is releasably attached to the whipstock 130 , for example, by a shear bolt 134 , thereby enabling the drill and whipstock to be conveyed into the casing string 114 in a single trip into the well.
The anchor 132 is engaged with an anchoring and orienting profile 136 in the casing string 114 below the tubular structure 112 . Such engagement secures the whipstock 130 relative to the tubular structure 112 and rotationally orients the whipstock relative to the tubular structure, so that an upper inclined deflection surface 138 of the whipstock faces toward the window 120 and the desired branch wellbore 122 .
Thereafter, the shear bolt 134 is sheared (for example, by slacking off on the work string 126 , thereby applying a downwardly directed force to the bolt), permitting the drill 128 to be laterally deflected off of the surface 138 and through the window 120 . The drill 128 is used to drill or mill outwardly through the shield 118 , and to drill the branch wellbore 122 . Of course, multiple cutting tools and different types of cutting tools may be used for the drill 128 during this drilling process.
As depicted in FIG. 9 , the casing string 114 has been cemented within the wellbore 116 prior to the drilling process. However, it is to be clearly understood that it is not necessary for the tubular structure 112 to be cemented in the wellbore 116 at this time. It may be desirable to delay cementing of the casing string 114 , or to forego cementing of the tubular structure 112 , as set forth in further detail below.
In FIG. 10 it may be seen that the branch wellbore 122 has been drilled extending outwardly from the window 120 of the tubular structure 112 by laterally deflecting one or more cutting tools from the parent wellbore 116 off of the deflection surface 138 of the whipstock 130 .
In FIG. 11 it may be seen that a liner string 140 is conveyed through the casing string 114 , and a lower end of the liner string is laterally deflected off of the surface 138 , through the window 120 , and into the branch wellbore 122 . An engagement device 142 attached at an upper end of the liner string 140 engages a tubular guide structure 144 of the tubular structure 112 , thereby securing the upper end of the liner string to the tubular structure. This engagement between the device 142 and the structure 112 forms a load-bearing connection between the casing string 114 and the liner string 140 , so that further displacement of the liner string into the branch wellbore 122 is prevented.
Engagement between the device 142 and the structure 144 may also rotationally secure the device relative to the tubular structure 112 . For example, the slot 66 and tab 68 described above may be used on the device 142 and structure 144 , respectively, to prevent rotation of the device in the tubular structure 112 . Other types of complementary engagement, and other means of rotationally securing the device 142 relative to the tubular structure 112 may be used in keeping with the principles of the invention.
Note that the device 142 is depicted in FIG. 11 as a radially outwardly extending flange-shaped member which inwardly overlaps the perimeter of the window 120 . The device 142 inwardly circumscribes the window 120 and overlaps its perimeter, so if one or both mating surfaces of the device and tubular structure 112 are provided with a suitable layer of sealing material (such as an elastomer, adhesive, relatively soft metal, etc.), a seal 146 may be formed between the device and the tubular structure due to the contact therebetween. The device 142 may be otherwise shaped, and may be otherwise sealed to the tubular structure 112 in keeping with the principles of the invention.
In FIG. 12 it may be seen that the whipstock 130 and anchor 132 are retrieved from the well and a generally tubular expandable member 148 is conveyed into the tubular structure 112 and expanded therein. For example, the expandable member 148 may be expanded radially outward using the expansion device 84 , from a radially compressed configuration (such as that depicted in FIG. 6 ) to a radially extended configuration (such as that depicted in FIG. 7 ).
The member 148 preferably has an opening 150 formed through a sidewall thereof when it is conveyed into the structure 112 . In that case, the opening 150 is preferably rotationally aligned with the window 120 (and thus rotationally aligned with an internal flow passage 152 of the liner string 140 ) prior to the member 148 being radially expanded. Alternatively, the member 148 could be conveyed into the structure 112 without the opening 150 having previously been formed, then expanded, and then a whipstock or other deflection device could be used to direct a cutting tool to form the opening through the sidewall of the member.
Note that the method 110 is illustrated in FIG. 12 as though the casing string 114 is cemented in the wellbore 116 at the time the member 148 is expanded in the structure 112 . However, the structure 112 could be cemented in the wellbore 116 after the member 148 is expanded therein.
After being expanded radially outward, the member 148 preferably has an internal diameter D 1 which is substantially equal to, or at least as great as, an internal diameter D 2 of the casing string 114 above the structure 112 . Thus, the member 148 does not obstruct flow or access through the structure 112 .
Note that a separate seal is not depicted in FIG. 12 between the member 148 and the device 142 or the structure 112 . Instead, seals 154 , 156 between the member 148 and the structure 112 above and below the guide structure 144 are formed by contact between the member 148 and the structure 112 when the member is expanded radially outward. For example, one or both mating surfaces of the member 148 and tubular structure 112 may be provided with a suitable layer of sealing material (such as an elastomer, adhesive, relatively soft metal, etc.), so that the seals 154 , 156 are formed between the member and the tubular structure due to the contact therebetween. The member 148 may be otherwise sealed to the tubular structure 112 in keeping with the principles of the invention.
To enhance sealing contact between the member 148 and the structure 112 and/or to ensure sufficient forming of the internal diameter D 1 , the structure may be expanded radially outward somewhat at the time the member is expanded radially outward, for example, by the expansion device 84 . This technique may produce some outward elastic deformation in the structure 112 , so that after the expansion process the structure will be biased radially inward to increase the surface contact pressure between the structure and the member 148 . Such an expansion technique may be particularly useful where it is desired for the seals 154 , 156 to be metal to metal seals. If this expansion technique is used, it may be desirable to delay cementing the structure 112 in the wellbore 116 until after the expansion process is completed.
Similarly, a seal 158 between the member 148 and the device 142 outwardly circumscribing the opening 150 is formed by contact between the member 148 and the device when the member is expanded radially outward. For example, one or both mating surfaces of the member 148 and device 142 may be provided with a suitable layer of sealing material (such as an elastomer, adhesive, relatively soft metal, etc.), so that the seal 158 is formed between the member and the device due to the contact therebetween. The member 148 may be otherwise sealed to the device 142 in keeping with the principles of the invention. Radially outward deformation of the structure 112 at the time the member 148 is expanded radially outward (as described above) may also enhance sealing contact between the member and the device 142 , particularly where the seal 158 is a metal to metal seal.
The expandable member 148 secures the device 142 in its engagement with the guide structure 144 . It will be readily appreciated that inward displacement of the device 142 is not permitted after the member 148 has been expanded. Furthermore, in the event that the device 142 has not yet fully engaged the guide structure 144 at the time the member 148 is expanded (for example, the device could be somewhat inwardly disposed relative to the guide structure), expansion of the member will ensure that the device is fully engaged with the guide structure (for example, by outwardly displacing the device somewhat).
Referring additionally now to FIG. 13 , an alternate procedure for use in the method 110 is representatively illustrated. This alternate procedure may be compared to the illustration provided in FIG. 8 . Instead of the outer shield 118 , the procedure illustrated in FIG. 13 uses an inner generally tubular shield 160 having an inclined upper surface or muleshoe 162 . Although no separate seals are shown in FIG. 13 , the inner shield 160 is preferably sealed to the tubular structure 112 above and below the guide structure 144 , so that cement or debris in the casing string 114 is not permitted to flow into the window 120 from the interior of the structure 112 . Preferably, the inner shield 160 is made of metal and is retrievable from within the structure 112 after the cementing process.
To prevent cement or debris from flowing into the structure 112 through the window 120 , a generally tubular outer shield 164 outwardly overlies the window. Preferably, the outer shield 164 is made of a relatively easily drillable material, such as a composite material (e.g., fiberglass, etc.). A fluid 166 having a relatively high viscosity is contained between the inner and outer shields 162 , 164 to provide support for the outer shield against external pressure, and to aid in preventing leakage of external fluids into the area between the shields. A suitable fluid for use as the fluid 166 is known by the trade name GLCOGEL, a relatively high viscosity fluid.
The muleshoe 162 provides a convenient surface for engagement by a conventional wireline-conveyed orienting tool (not shown). Such a tool may be engaged with the muleshoe 162 and used to rotationally orient the structure 112 relative to the branch wellbore-to-be-drilled 122 , since the muleshoe has a known radial orientation relative to the window 120 .
After the structure 112 has been appropriately rotationally oriented, the casing string 114 may be cemented in the wellbore 116 , and the inner shield 160 may then be retrieved from the well. After retrieval of the inner shield 160 , the method 110 may proceed as described above, i.e., the whipstock 130 and anchor 132 may be installed, etc. Alternatively, the inner shield 160 may be retrieved prior to cementing the structure 112 in the wellbore 116 .
Referring additionally now to FIGS. 14โ17 , another method 170 embodying principles of the invention is representatively illustrated. The method 170 differs from the other methods described above in substantial part in that a specially constructed tubular structure is not necessarily used in a casing string 172 to provide a window through a sidewall of the string. Instead, a window 176 is formed through a sidewall of the casing string 172 using conventional means, such as by use of a conventional whipstock (not shown) anchored and oriented in the casing string according to conventional practice.
One of the many benefits of the method 170 is that it may be used in existing wells wherein casing has already been installed. Furthermore, the method 170 may even be performed in wells in which the window 176 has already been formed in the casing string 172 . However, it is to be clearly understood that it is not necessary for the method 170 to be performed in a well wherein existing casing has already been cemented in place. The method 170 may be performed in newly drilled or previously uncased wells, and in wells in which the casing has not yet been cemented in place.
In FIG. 15 it may be seen that a liner string 178 is conveyed into a branch wellbore 180 which has been drilled extending outwardly from the window 176 . At its upper end, the liner string 178 includes an engagement device 182 which engages the interior of the casing string 172 and prevents further displacement of the liner string 178 into the branch wellbore 180 . Engagement of the device 182 with the casing string 172 may also rotationally align the device with respect to the casing string.
As depicted in FIG. 15 , the device 182 is a flange extending outwardly from the remainder of the liner string 178 . The device 182 inwardly overlies the perimeter of the window 176 and circumscribes the window. Contact between an outer surface of the device 182 and an inner surface of the casing string 172 may be used to provide a seal 184 therebetween, for example, if one or both of the inner and outer surfaces is provided with a layer of a suitable sealing material, such as an elastomer, adhesive or a relatively soft metal, etc. Thus, the seal 184 may be a metal to metal seal. Other types of seals may be used in keeping with the principles of the invention.
In an optional procedure of the method 170 , the liner string 178 (or at least the device 182 ) may be in a radially compressed configuration (such as that depicted in FIG. 6 ) when it is initially installed in the branch wellbore 180 , and then extended to a radially expanded configuration (such as that depicted in FIG. 7 ) thereafter. This expansion of the liner string 178 , or at least expansion of the device 182 , may be used to bring the device into sealing contact with the casing string 172 .
In FIG. 16 it may be seen that a generally tubular expandable member 186 is conveyed into the casing string 172 and aligned longitudinally with the device 182 . The member 186 has an opening 188 formed through a sidewall thereof. The opening 188 is rotationally aligned with the window 176 (and thus aligned with a flow passage 190 of the liner string 178 ).
However, it is not necessary for the opening 188 to be formed in the member 186 prior to conveying the member into the well, or for the opening to be aligned with the window 176 at the time it is positioned opposite the device 182 . For example, the opening 188 could be formed after the member 186 is installed in the casing string 172 , such as by using a whipstock or other deflection device to direct a cutting tool to cut the opening laterally through the sidewall of the member.
As depicted in FIG. 16 , the member 186 has an outer layer of a suitable sealing material 192 thereon. The sealing material 192 may be any type of material which may be used to form a seal between surfaces brought into contact with each other. For example, the sealing material 192 may be an elastomer, adhesive or relatively soft metal, etc. Other types of seals may be used in keeping with the principles of the invention.
In FIG. 17 it may be seen that the member 186 is expanded radially outward, so that it now contacts the interior of the casing string 172 and the device 182 . Preferably, such contact results in sealing engagement between the member 186 and the interior surface of the casing string 172 , and between the member and the device 182 .
Specifically, the sealing material 192 seals between the member 186 and the casing string 172 above, below and circumscribing the device 182 . The sealing material 192 also seals between the member 186 and the device 182 around the outer periphery of the opening 188 , that is, sealing engagement between the device 182 and the member 186 circumscribes the opening 188 . Thus, the interiors of the casing and liner strings 172 , 178 are completely isolated from the wellbores 174 , 180 external to the strings. This substantial benefit of the method 170 is also provided by the other methods described herein.
As depicted in FIG. 17 , the casing string 172 is outwardly deformed when the member 186 is radially outwardly expanded therein. At least some elastic deformation, and possibly some plastic deformation, of the casing string 172 outwardly overlying the member 186 is experienced, thereby recessing the member into the interior wall of the casing string.
As a result, the inner diameter D 3 of the member 186 is substantially equal to, or at least as great as, the inner diameter D 4 of the casing string 172 above the window 176 . Preferably, during the expansion process, the inner diameter D 3 of the member 186 is enlarged until it is greater than the inner diameter D 4 of the casing string 172 , so that after the expansion force is removed, the diameter D 3 will relax to a dimension no less than the diameter D 4 .
Thus, the method 170 does not result in substantial restriction of flow or access through the casing string 172 . This substantial benefit of the method 170 is also provided by other methods described herein.
Outward elastic deformation of the casing string 172 in the portions thereof overlying the member 186 is desirable in that it inwardly biases the casing string, increasing the contact pressure between the mating surfaces of the member and the casing string, thereby enhancing the seal therebetween, after the member has been expanded. However, it is to be clearly understood that it is not necessary, in keeping with the principles of the invention, for the casing string 172 to be outwardly deformed, since the member 186 may be expanded radially outward into sealing contact with the interior surface of the casing string without deforming the casing string at all.
When the member 186 is expanded, it also outwardly displaces the device 182 . This outward displacement of the device 182 further outwardly deforms the casing string 172 where it overlies the device. Elastic deformation of the casing string 172 overlying the device 182 is desirable in that it results in inward biasing of the casing string when the expansion force is removed. This enhances the seal 184 between the device 182 and the casing string 172 , and further increases the contact pressure on the sealing material between the device 182 and the member 186 .
The method 170 is depicted in FIG. 17 as though the casing string 172 is not yet cemented in the parent wellbore 174 at the time the member 186 is expanded therein. This alternate order of steps in the method 170 may be desirable in that it may facilitate outward deformation of the casing string 172 above and below the window 176 . The casing and/or liner strings 172 , 178 may be cemented in the respective wellbores 174 , 180 after the member 186 is expanded.
Referring additionally now to FIGS. 18โ20 , another method 200 embodying principles of the invention is representatively illustrated. In FIG. 18 it may be seen that a tubular structure 202 is cemented in a parent wellbore 204 at an intersection with a branch wellbore 206 . However, it is not necessary for the tubular structure 202 to be cemented in the wellbore 204 until later in the method 200 , if at all.
The structure 202 is interconnected in a casing string 208 . The casing string 208 is rotationally oriented in the wellbore 204 so that a window 210 formed through a sidewall of the structure 202 is aligned with the branch wellbore 206 . Note that the window may be formed through the sidewall of the structure 202 , and that the branch wellbore 206 may be drilled, either before or after the structure is conveyed into the wellbore 204 .
A liner string 212 is conveyed into the branch wellbore 206 in a radially compressed configuration. Even though it is radially compressed, a flange-shaped engagement device 214 at an upper end of the liner string 212 is larger than the window 210 , and so the device prevents further displacement of the liner string into the wellbore 206 . Preferably, this engagement between the device 214 and the structure 202 is sufficiently load-bearing so that it may support the liner string 212 in the wellbore 206 .
An annular space 216 is provided radially between the device 214 and an opening 218 formed through the sidewall of a guide structure 220 . When the liner string 212 is expanded, the device 214 deforms radially outwardly into the annular space 216 . The liner string 212 is shown in its expanded configuration in FIG. 19 .
As depicted in FIG. 20 , a generally tubular expandable member 222 is radially outwardly expanded within the structure 202 . An opening 224 formed through a sidewall of the member 222 is rotationally aligned with a flow passage of the liner string 212 . The opening 224 may be formed before or after the member 222 is expanded.
Preferably, this expansion of the member 222 seals between the outer surface of the member and the inner surface of the structure 202 above and below the guide structure 220 , and seals between the member and the device 214 . Thus, the interiors of the casing and liner strings 208 , 212 are isolated from the wellbores 204 , 206 external to the strings. Alternatively, or in addition, a seal may be formed between the device 214 and the structure 202 circumscribing the window 210 where the structure outwardly overlies the device.
Preferably the seals obtained by expansion of the member 222 are due to surface contact between elements, at least one of which is displaced in the expansion process. For example, one of both of the member 222 and structure 202 may have a layer of sealing material (e.g., a layer of elastomer, adhesive, or soft metal, etc.) thereon which is brought into contact with the other element when the member is expanded. Metal to metal seals are preferred, although other types of seals may be used in keeping with the principles of the invention.
As depicted in FIG. 20 , the tubular structure 202 , and the casing string 208 somewhat above and below the structure, are radially outwardly expanded when the member 222 is expanded. This optional step in the method 200 may be desirable to enhance access and/or flow through the structure 202 , enhance sealing contact between any of the member 222 , device 214 , structure 202 , etc. If the casing string 208 is outwardly deformed in the method 200 , it may be desirable to cement the casing string in the wellbore 204 after the expansion process is completed.
Referring additionally now to FIGS. 21โ25 another method 230 embodying principles of the invention is representatively illustrated. As depicted in FIG. 21 , an expandable liner string 232 is conveyed through a casing string 234 positioned in a parent wellbore 236 . A lower end of the liner string 232 is deflected laterally through a window 237 formed through a sidewall of a tubular structure 238 interconnected in the casing string 234 , and into a branch wellbore 240 extending outwardly from the window.
An expandable liner hanger 242 is connected at an upper end of the liner string 232 . The liner hanger 242 is positioned within the casing string 234 above the window 237 .
The liner string 232 is then expanded radially outward as depicted in FIG. 22 . As a result of this expansion process, the liner hanger 242 sealingly engages between the liner string 232 and the casing string 234 , and anchors the liner string relative to the casing string. Another result of the expansion process is that a seal is formed between the liner string and the window 237 of the structure 238 . Thus, the interiors of the casing and liner strings 232 , 234 are isolated from the wellbores 236 , 240 external to the strings. The seal formed between the liner string 232 and the window 237 is preferably a metal to metal seal, although other types of seals may be used in keeping with the principles of the invention.
A portion 244 of the liner string 232 extends laterally across the interior of the casing string 234 above a deflection device 246 positioned below the window 237 . As depicted in FIG. 23 , a milling or drilling guide 248 is used to guide a drill, mill or other cutting tool 250 to cut through the sidewall of the liner string 232 at the portion 244 above the deflection device 246 . In this manner, access and flow between the casing string 234 above and below the liner portion 244 through an internal flow passage 252 of the deflection device 246 is provided.
Alternatively, the liner portion 244 may have an opening 254 formed therethrough. The opening 254 may be formed, for example, by waterjet cutting through the sidewall of the liner string 232 . The opening 254 may be formed before or after the liner string 232 is conveyed into the well.
Preferably, the opening 254 is formed with a configuration such that it has multiple flaps or inward projections 256 which may be folded to increase the inner dimension of the opening, e.g., to enlarge the opening for enhanced access and flow therethrough. As depicted in FIG. 25 , the projections 256 are folded over by use of a drift or punch 258 , thereby enlarging the opening 254 through the liner portion 244 .
The projections 256 are thus displaced into the passage 252 of the deflection device 246 below the liner string 232 . A seal may be formed between the liner portion 244 and the deflection device 246 circumscribing the opening 254 in this process of deforming the projections 256 downward into the passage 252 . Preferably, the seal is due to metal to metal contact between the liner portion 244 and the deflection device 246 , but other types of seals may be used in keeping with the principles of the invention.
Referring additionally now to FIGS. 26 & 27 , another method 260 of sealing and securing a liner string 262 in a branch wellbore to a tubular structure 264 interconnected in a casing string in a parent wellbore is representatively illustrated. Only the structure 264 and liner string 262 are shown in FIG. 26 for illustrative clarity.
In FIG. 26 it may be seen that the liner string 262 is positioned so that it extends outwardly through a window 266 formed through a sidewall of the structure 264 . The liner string 262 would, for example, extend into a branch wellbore intersecting the parent wellbore in which the structure 264 is positioned.
An upper end 268 of the liner string 262 remains within the tubular structure 264 . To secure the liner string 262 in this position, a packer or other anchoring device interconnected in the liner string may be set in the branch wellbore, or a lower end of the liner string may rest against a lower end of the branch wellbore, etc. Any method of securing the liner string 262 in this position may be used in keeping with the principles of the invention.
As depicted in FIG. 26 , the upper end 268 is formed so that it is parallel with a longitudinal axis of the structure 264 . The upper end 268 may be formed in this manner prior to conveying the liner string 262 into the well, or the upper end may be formed after the liner string is positioned as shown in FIG. 26 , for example, by milling an upper portion of the liner string after it is secured in position. If the upper end 268 is formed prior to conveying the liner string 262 into the well, then the upper end may be rotationally oriented relative to the structure 264 prior to securing the liner string 262 in the position shown in FIG. 26 .
In FIG. 27 it may be seen that the upper end 268 of the liner string 262 is deformed radially outward so that it is received in an opening 270 formed through the sidewall of a generally tubular guide structure 272 in the tubular structure 264 . The opening 270 is rotationally aligned with the window 266 .
The upper end 268 is deformed outward by means of a mandrel 274 which is conveyed into the structure 264 and deflected laterally toward the upper end of the liner string 262 by a deflection device 276 . The mandrel 274 shapes the upper end 268 so that it becomes an outwardly extending flange which overlaps the interior of the structure 264 circumscribing the window 266 , that is, the flange-shaped upper end 268 inwardly overlies the perimeter of the window.
Preferably, a seal is formed between the flange-shaped upper end 268 and the interior surface of the structure 264 circumscribing the window 266 . This seal may be a metal to metal seal, may be formed by a layer of sealing material on one or both of the upper end 268 and the structure 264 , etc. Any type of seal may be used in keeping with the principles of the invention.
The flange-shaped upper end 268 also secures the liner string 262 to the structure 264 in that it prevents further outward displacement of the liner string through the window 266 . After the deforming process is completed, the mandrel 274 and deflection device 276 may be retrieved from within the structure 264 and a generally tubular expandable member (not shown) may be positioned in the structure and expanded therein. For example, any of the expandable members 82 , 148 , 186 , 222 described above may be used.
After expansion of the member in the structure 264 , the member further secures the liner string 262 relative to the structure by preventing inward displacement of the liner string through the window 266 . Various seals may also be formed between the expanded member and the structure 264 , the flange-shaped upper end 268 , and/or the guide structure 272 , etc. as described above. Any types of seals may be used in keeping with the principles of the invention.
Referring additionally now to FIGS. 28 & 29 , another method 280 of sealing and securing a liner string 282 in a branch wellbore to a tubular structure 284 interconnected in a casing string in a parent wellbore is representatively illustrated. In FIG. 28 a generally tubular expandable member 286 used in the method 280 is shown. The member 286 has a specially configured opening 288 formed through a sidewall thereof. The opening 288 may be formed, for example, by waterjet cutting, either before or after it is conveyed into the well.
The configuration of the opening 288 provides multiple inwardly extending flaps or projections 290 which may be folded to enlarge the opening. As depicted in FIG. 29 , the opening 288 has been enlarged by folding the projections 290 outward into the interior of the upper end of the liner string 282 . The projections 290 are deformed outward, for example, by a mandrel and deflection device such as the mandrel 274 and deflection device 276 described above, but any means of deforming the projections into the liner string 282 may be used in keeping with the principles of the invention.
The projections 290 are deformed outward after the member 286 is positioned within the structure 284 , the opening 288 is rotationally aligned with a window 292 formed through a sidewall of the structure, and the member is expanded radially outward. Of course, if the opening 288 is formed after the member 286 is expanded in the structure 284 , then the rotational alignment step occurs when the opening is formed.
Expansion of the member 286 secures an upper flange-shaped engagement device 294 relative to the structure 284 . Seals may be formed between the member 286 , structure 284 , engagement device 294 and/or a guide structure 296 , etc. as described above. Any types of seals may be used in keeping with the principles of the invention.
Furthermore, deformation of the projections 290 into the liner string 282 may also form a seal between the member 286 and the liner string about the opening 288 . For example, a metal to metal seal may be formed by contact between an exterior surface of the member 286 and an interior surface of the liner string 282 when the projections 290 are deformed into the liner string. Other types of seals may be used in keeping with the principles of the invention.
Preferably, the projections 290 are deformed into an enlarged inner diameter D 5 of the liner string 282 . This prevents the projections 290 from unduly obstructing flow and access through an inner passage 298 of the liner string 282 .
Referring additionally now to FIG. 30 , another method 300 of sealing and securing a liner string 302 in a branch wellbore to a tubular structure 304 interconnected in a casing string in a parent wellbore is representatively illustrated. The method 300 is similar to the method 280 in that it uses an expandable tubular member, such as the member 286 having a specially configured opening 288 formed through its sidewall. However, in the method 300 , the member 286 is positioned and expanded radially outward within the structure 304 prior to installing the liner string 302 in the branch wellbore through a window 306 formed through a sidewall of the structure.
Expansion of the member 286 within the structure 304 preferably forms a seal between the outer surface of the member and the inner surface of the structure, at least circumscribing the window 306 , and above and below the window. The seal is preferably a metal to metal seal, but other types of seals may be used in keeping with the principles of the invention.
After the member 286 has been expanded within the structure 304 , the projections 290 are deformed outward through the window 306 . This outward deformation of the projections 290 may result in a seal being formed between the inner surface of the window 306 and the outer surface of the member 286 circumscribing the opening 288 . Preferably the seal is a metal to metal seal, but any type of seal may be used in keeping with the principles of the invention.
After the projections 290 are deformed outward through the window 306 , the liner string 302 is conveyed into the well and its lower end is deflected through the window 306 and the opening 288 , and into the branch wellbore. The vast majority of the liner string 302 has an outer diameter D 6 which is less than an inner diameter D 7 through the opening 288 and, therefore, passes through the opening with some clearance therebetween. However, an upper portion 308 of the liner string 302 has an outer diameter D 8 which is preferably at least as great as the inner diameter D 7 of the opening 288 . If the diameter D 8 is greater than the diameter D 7 , some additional downward force may be needed to push the upper portion 308 of the liner string 302 through the opening 288 . In this case, the liner upper portion 308 may further outwardly deform the projections 290 , thereby enlarging the opening 288 , as it is pushed through the opening.
Contact between the outer surface of the liner upper portion 308 and the inner surface of the opening 288 may cause a seal to be formed therebetween circumscribing the opening. Preferably, the seal is a metal to metal seal, but other seals may be used in keeping with the principles of the invention. An upper end 310 of the liner string 302 may be cut off as shown in FIG. 30 , so that it does not obstruct flow or access through the structure 304 . Alternatively, the upper end 310 may be formed prior to conveying the liner string 302 into the well.
Referring additionally now to FIGS. 31โ35 , another method 320 embodying principles of the invention is representatively illustrated. In FIG. 31 it may be seen that a liner string 322 is conveyed through a casing string 324 in a parent wellbore 326 , and a lower end of the liner string is deflected laterally through a window 330 formed through a sidewall of the casing string, and into a branch wellbore 328 . The casing string 324 may or may not be cemented in the parent wellbore 326 at the time the liner string 322 is installed in the method 320 .
The liner string 322 includes a portion 332 which has an opening 334 formed through a sidewall thereof. In addition, an external layer of sealing material 336 is disposed on the liner portion 332 . The sealing material 336 may be, for example, an elastomer, an adhesive, a relatively soft metal, or any other type of sealing material. Preferably, the sealing material 336 outwardly circumscribes the opening 334 and extends circumferentially about the liner portion 332 above and below the opening.
The liner string 322 is positioned as depicted in FIG. 31 , with the liner portion 332 extending laterally across the interior of the casing string 324 and the opening 334 facing downward. However, it is to be clearly understood that it is not necessary for the opening 334 to exist in the liner portion 332 prior to the liner string 322 being conveyed into the well. Instead, the opening 334 could be formed downhole, for example, by using a cutting tool and guide, such as the cutting tool 250 and guide 248 described above. As another alternative, the opening 334 may be specially configured (such as the opening 254 depicted in FIG. 24 ), and then enlarged (as depicted for the opening 254 in FIG. 25 ).
In FIG. 32 it may be seen that the liner string 322 is expanded radially outward. Preferably, at least the liner portion 332 is expanded, but the remainder of the liner string 322 may also be expanded. Due to expansion of the liner portion 332 , the outer surface of the liner portion contacts and seals against the inner surface of the window 330 circumscribing the window. The seal between the liner portion 332 and the window 330 is facilitated by the sealing material 336 contacting the inner surface of the window. However, the seal could be formed by other means, such as metal to metal contact between the liner portion 332 and the window 330 , without use of the sealing material 336 , in keeping with the principles of the invention.
In FIG. 33 it may be seen that the opening 334 is expanded to provide enhanced flow and access between the interior of the casing string 324 below the window 330 and the interior of the liner string 322 above the window. Expansion of the opening 334 also results in a seal being formed between the exterior surface of the liner portion 332 circumscribing the opening 334 and the interior of the casing string 324 . At this point, it will be readily appreciated that the interiors of the casing and liner strings 324 , 322 are isolated from the wellbores 326 , 328 external to the strings.
Additional steps in the method 320 may be used to further seal and secure the connection between the liner and casing strings 322 , 324 . In FIG. 34 it may be seen that the liner string 322 within the casing string 324 is further outwardly expanded so that it contacts and radially outwardly deforms the casing string. The opening 334 is also further expanded, and a portion 338 of the liner string 322 may be deformed downwardly into the casing string 324 as the opening is expanded.
This further expansion of the liner string 322 , including the opening 334 , in the casing string 324 produces several desirable benefits. The liner string 322 is recessed into the inside wall of the casing string 324 , thereby providing an inner diameter D 9 in the liner string which is preferably substantially equal to, or at least as great as, an inner diameter D 10 of the casing string 324 above the window 330 . The seal between the outer surface of the liner string 322 circumscribing the opening 334 and the inner surface of the casing string 324 is enhanced by increased contact pressure therebetween. In addition, another seal may be formed between the outer surface of the liner string 322 and the inner surface of the casing string 324 above the window 330 . Furthermore, the downward deformation of the portion 338 into the casing string 324 below the window 330 enhances the securement of the liner string 322 to the casing string. As described above, outward elastic deformation of the casing string 324 may be desirable to induce an inwardly biasing force on the casing string when the expansion force is removed, thereby maintaining a relatively high level of contact pressure between the casing and liner strings 324 , 322 .
In FIG. 35 it may be seen that a generally tubular expandable member 340 having an opening 342 formed through a sidewall thereof is positioned within the casing string 324 with the opening 342 rotationally aligned with the window 330 and, thus, with a flow passage 344 of the liner string 322 . The member 340 extends above and below the liner string 322 in the casing string 324 and extends through the opening 334 . The member 340 is then expanded radially outward within the casing string 324 .
Expansion of the member 340 further secures the connection between the liner and casing strings 322 , 324 . Seals may be formed between the outer surface of the member 340 and the interior surface of the casing string 324 above and below the liner string 322 , and the inner surface of the liner string in the casing string. The seals are preferably formed due to contact between the member 340 outer surface and the casing and liner strings 324 , 322 inner surfaces. For example, the seals may be metal to metal seals. The seals may be formed due to a layer of sealing material on the member 340 outer surface and/or the casing and liner strings 324 , 322 inner surfaces. However, any types of seals may be used in keeping with the principles of the invention.
The member 340 may be further expanded to further outwardly deform the casing string 324 where it overlies the member, in a manner similar to that used to expand the member 186 in the method 170 as depicted in FIG. 17 . In that way, the member 340 may be recessed into the inner wall of the casing string 324 and the inner diameter D 11 of the member may be enlarged so that it is substantially equal to, or at least as great as, the inner diameter D 10 of the casing string. Due to outward deformation of the casing string 324 in the method 320 , whether or not the member 340 is recessed into the inner wall of the casing string, it may be desirable to delay cementing of the casing string in the parent wellbore 326 until after the expansion process is completed.
Thus have been described the methods 10 , 110 , 170 , 200 , 230 , 260 , 280 , 300 , 320 which provide improved connections between tubular strings in a well. It should be understood that openings and windows formed through sidewalls of tubular members and structures described herein may be formed before or after the tubular members and structures are conveyed into a well. Also, it should be understood that casing and/or liner strings may be cemented in parent or branch wellbores at any point in the methods described above.
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the invention, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to these specific embodiments, and such changes are contemplated by the principles of the present invention. For example, although certain seals have been described above as being carried on one element for sealing engagement with another element, it will be readily appreciated that seals may be carried on either or neither element. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.
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A sealed multilateral junction system provides fluid isolation between intersecting wellbores in a subterranean well. In a described embodiment, a method of forming a wellbore junction includes the steps of sealing a tubular string in a branch wellbore to a tubular structure in a parent wellbore. The tubular string may be secured to the tubular structure utilizing a flange which is larger in size than a window formed in the tubular structure. The flange may be sealed to the tubular structure about the window by a metal to metal seal or by adhering the flange to the tubular structure.
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FIELD OF THE INVENTION
[0001] This invention relates generally to the field of downhole pumping systems, and more particularly to encapsulated bottom intake pumping systems.
BACKGROUND
[0002] Submersible pumping systems are often deployed into wells to recover petroleum fluids from subterranean reservoirs. Submersible pumping systems often include an electric motor coupled to a pump assembly. When driven by a motor, the pump assembly moves fluids from the reservoir to surface facilities through production tubing. In many installations, the discharge from the pump assembly is connected directly to the production tubing. In these installations, the motor is commonly placed below the pump assembly at the terminal end of the equipment string.
[0003] In other applications, however, it is desirable to place the pump assembly below the electric motor. Prior art โbottom intakeโ pumping systems are often used in combination with a shroud and an intake tailpipe to draw fluids from a lower well zone that has been isolated from the pump assembly by a packer. Although widely used, prior art bottom intake pumping systems are prone to mechanical failure. Furthermore, the shroud assemblies used to encapsulate bottom-intake pumping system must be custom fabricated under strict tolerances for proper fit. There is therefore a need for a more robust and easier to manufacture bottom intake pumping system.
SUMMARY OF THE INVENTION
[0004] In a preferred embodiment, the present invention includes a bottom-intake pumping system having a pump assembly, a motor configured to drive the pump assembly and a driveshaft assembly for delivering power from the motor to the pump assembly. A first thrust bearing supports the driveshaft assembly on a first side of the pump assembly and a second thrust bearing supports the driveshaft assembly on a second side of the pump assembly.
[0005] In another aspect, the preferred embodiment includes a shroud assembly and a discharge pipe. The shroud assembly preferably includes a lower shroud hanger configured for rigid attachment at a selected location on the pump assembly, a shroud body connectable to the lower shroud hanger and an upper shroud hanger connectable to the shroud body. The upper shroud hanger is preferably configured for sliding engagement with the discharge pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a front view of a bottom-intake pumping system with a cross-sectional view of the shroud assembly constructed in accordance with a presently preferred embodiment.
[0007] FIG. 2 is a partial cross-section view of the bottom-intake pumping system of FIG. 1 depicting the internal components of the upper seal section, pump assembly and lower seal section of a preferred embodiment.
[0008] FIG. 3 is a partial cross-sectional view of the pump assembly and lower seal section.
[0009] FIG. 4 is a cross-sectional, exploded view of the shroud assembly of FIG. 1 .
[0010] FIG. 5 is a cross-sectional view of the shroud assembly of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] In accordance with a preferred embodiment of the present invention, FIG. 1 shows a front perspective view of a downhole pumping system 100 attached to production tubing 102 . The downhole pumping system 100 and production tubing 102 are disposed in a wellbore 104 , which is drilled for the production of a fluid such as water or petroleum. As used herein, the term โpetroleumโ refers broadly to all mineral hydrocarbons, such as crude oil, gas and combinations of oil and gas. Although the pumping system 100 is primarily designed to pump petroleum products, it will be understood that the present invention can also be used to move other fluids, which may be generically referred to as โwellbore fluidsโ while in the ground or โproduced fluidsโ on the surface.
[0012] The production tubing 102 connects the pumping system 100 to a wellhead 106 located on the surface. The wellhead 106 is in turn connected to surface facilities for transporting, refining or storing the produced fluids. It will be understood that, although each of the components of the pumping system 100 are primarily disclosed in a submersible application, some or all of the components disclosed herein can also be used in surface pumping operations.
[0013] The pumping system 100 preferably includes some combination of a pump assembly 108 , a motor assembly 110 , an upper seal section 112 and a lower seal section 114 . In a preferred embodiment, the motor assembly 110 is an electrical motor that receives its power from a surface-based source. Generally, the motor assembly 110 converts the electrical energy into mechanical energy, which is transmitted to the pump assembly 108 through a series of connected shafts that are collectively referred to as the driveshaft assembly 116 (not shown in FIG. 1 ).
[0014] The pump assembly 108 transfers a portion of this mechanical energy to fluids within the wellbore, causing the wellbore fluids to move through the production tubing 102 to the surface. In a particularly preferred embodiment, the pump assembly 108 is a turbomachine that uses one or more impellers and diffusers to convert mechanical energy into pressure head. In an alternative embodiment, the pump assembly 108 is a progressive cavity (PC) pump that moves wellbore fluids with one or more screws or pistons.
[0015] In the preferred embodiment, the pumping system 100 is configured as a shrouded bottom-intake pumping system in which the pump assembly 108 is located below the motor 110 . The pump assembly 108 preferably includes an intake 118 and a discharge 120 . The lower seal section 114 is preferably connected to the intake 118 at the terminal end of the pumping system 100 . The upper seal section is preferably connected between the discharge 120 and the motor 110 . In this way, the upper and lower seal sections 112 , 114 are connected to a โdischarge endโ and an โintake end,โ respectively, of the pump assembly 108 .
[0016] The pumping system 100 also includes a shroud assembly 122 , a discharge pipe 124 and a cross-over 126 . The discharge pipe 124 is preferably connected to the production tubing 102 and the cross-over 126 . The cross-over 126 is preferably secured to the top of the motor 110 . In this way, the shroud assembly 122 creates a substantially sealed fluid path between the discharge 120 and the cross-over 126 around the external surface of the upper seal section 112 and the motor 110 . Fluids discharged from the pump assembly 108 are retained within the shroud assembly 122 and forced into the discharge pipe 124 through the cross-over 126 . Forcing wellbore fluids through the shroud assembly 122 lowers the temperature of the internal motor lubricant and motor components. Lower operating temperatures result in improved motor life and reduced levels of scaling.
[0017] Turning now to FIG. 2 , shown therein is a cross-sectional view of the upper seal section 112 . The upper seal section 112 is designed to equalize the pressure inside the motor 110 with the pressure in the wellbore and to compensate for the expansion and contraction of motor lubricants due to changes in the temperature of the motor 110 . In a presently preferred embodiment, the upper seal section 112 is configured as a labyrinth-type seal section that uses a tortuous fluid path and gravity separation to permit the expansion of motor lubricants while preventing contaminated well fluid from reaching the motor 110 . In an alternate embodiment, the upper seal section 112 includes one or more elastomeric bags in addition to, or in place of, the labyrinth-type seal. The elastomeric bags function as a positive barrier between the motor lubricant and corrosive well fluids. The upper seal section 112 preferably also includes an upper thrust bearing 128 that is designed to carry a portion of the axial thrust developed by the pump assembly 108 . In a particularly preferred embodiment, the thrust bearing includes a rotating runner 130 bounded by first and second stationary thrust pads 132 , 134 .
[0018] Turning to FIG. 3 , shown therein is a cross-sectional depiction of the lower seal section 114 . In the presently preferred embodiment, the lower seal section 114 is configured as a bag-type seal that includes an elastomeric bag 136 . The elastomeric bag 136 prevents wellbore fluids from the pump assembly 108 from contacting other internal components within the lower seal section 114 . Although a single elastomeric bag 136 is presently preferred, it will be understood that additional elastomeric bags 136 can be used. In an alternate preferred embodiment, the elastomeric bag 136 is replaced by, or used in conjunction with, a labyrinth-type seal mechanism.
[0019] The lower seal section 114 also includes a lower thrust bearing 138 that works in concert with the upper thrust bearing 128 to absorb mechanical shock induced in the driveshaft assembly 116 during operation. Like the upper thrust bearing 128 , the lower thrust bearing 138 preferably includes a rotating runner 140 and first and second thrust pads 142 , 144 . The axial movement of the driveshaft assembly 116 and runner 140 is limited by the first and second thrust pads 142 , 144 . In this way, the driveshaft assembly 116 is supported by upper and lower thrust bearings 128 , 138 , respectively, on opposing ends of the pumping system 100 . Supporting the driveshaft assembly 116 on both ends of the pumping system 100 reduces the likelihood that the driveshaft assembly 116 will become pinned or sheared when subjected to excessive downthrust or torque.
[0020] Turning now to FIGS. 4 and 5 , shown therein are exploded and assembled elevational views, respectively, of the shroud assembly 122 and the associated other portions of the pumping system 100 . In the presently preferred embodiment, the shroud assembly 122 includes a lower shroud hanger 146 , a shroud body 148 and an upper shroud hanger 150 . The shroud body 148 is preferably configured for mating engagement between the lower shroud hanger 146 and the upper shroud hanger 150 . In a particularly preferred embodiment, the shroud body 148 , upper shroud hanger 150 and lower shroud hanger 148 include threaded portions that permit a secure engagement.
[0021] The lower shroud hanger 146 is preferably secured to the pump assembly 108 below the discharge 120 . In the presently preferred embodiment, the lower shroud hanger 148 is preferably a conventional shroud hanger that rigidly secures the shroud assembly 122 to the pump assembly 108 . The attachment of conventional shroud hangers is well known in the art. The shroud body 148 is preferably configured as an elongated cylinder having a length sufficient to extend above the crossover 126 when secured to the lower shroud hanger 146 .
[0022] The upper shroud hanger 150 preferably includes a central bore 152 , a plurality of central seals 154 and at least one penetrator assembly 156 . The central bore 152 is preferably sized and configured to receive the discharge pipe 124 . The central seals 154 are configured to engage the discharge pipe 124 to form a substantially sealed connection between the discharge pipe 124 and the upper shroud hanger 150 . In a particularly preferred embodiment, the discharge pipe 124 is a polished, non-upset pup-joint connected between the cross-over 126 and the production tubing 102 . In this particularly preferred embodiment, the central seals 154 are configured as โo-ringsโ with an inner diameter substantially equivalent to the outer diameter of the discharge pipe 124 . The at least one penetrator assembly 156 permits the introduction of power or signal cables into the shroud assembly 122 . During assembly, cables from the motor 110 can be fed through the upper shroud hanger 150 as it is lowered onto the discharge pipe 124 . The upper shroud hanger 150 can then be moved down the discharge pipe 124 a desired extent to connect the components within the shroud assembly 122 .
[0023] Thus, unlike prior art shroud assemblies that are constructed at specific lengths to be secured at specific locations on the pumping system, the shroud assembly 122 of the preferred embodiment can be constructed without requiring specific length and attachment points. With the sliding engagement of the upper shroud hanger 150 on the discharge pipe 124 , a single shroud assembly 122 can be used to encapsulate a variety of pumping systems 100 .
[0024] It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and functions of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. It will be appreciated by those skilled in the art that the teachings of the present invention can be applied to other systems without departing from the scope and spirit of the present invention.
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Disclosed is a bottom-intake pumping system that includes a pump assembly and a motor that drives the pump assembly with a driveshaft assembly. The bottom-intake pumping system includes a first thrust bearing that supports the driveshaft assembly on a first side of the pump assembly and a second thrust bearing that supports the driveshaft assembly on a second side of the pump assembly. The bottom-intake pumping system also includes a shroud assembly and a discharge pipe. The shroud assembly has a lower shroud hanger configured for rigid attachment at a selected location on the pump assembly, a shroud body connectable to the lower shroud hanger and an upper shroud hanger connectable to the shroud body. The upper shroud hanger is configured for sliding engagement with a discharge pipe.
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TECHNICAL FIELD
[0001] The invention relates generally to engine parts and, more particularly, to an improved method for restoring a flange of an engine part and device for doing same.
BACKGROUND OF THE ART
[0002] A current approach for reworking flanges of various engine parts involves brute force bending the flange at discrete locations with a mechanical hand press. There are numerous disadvantages to the device and process involved. A first disadvantage is that it is significantly dangerous for employees to operate the hand press due to the excessive effort required to obtain the desired result. Several recorded accidents and numerous unrecorded incidents have occurred. Consequently, many operators refuse to do the job claiming that the working conditions are unacceptable.
[0003] A second disadvantage is that the quality of restoring flanges, within a particular tolerance, using the above-mentioned device is inconsistent. This is largely due to the fact that the pressure applied by the operator is not readily measurable, thus, results may vary considerably. More specifically, the application of pressure on a flange is determined by the effort applied on the handle of the device by the operator. In an attempt to gain the last thousandths of the tolerance, an operator may surpass the acceptable limit. Furthermore, the weight of the operator is a determining factor of the amount of pressure applied; hence, diverse operators yield varying outcomes resulting in inconsistent quality.
[0004] A third disadvantage is that the turn around time relevant to the use of the mechanical hand press and corresponding method involved is extensive due to the numerous secondary operations required known in the art.
[0005] Accordingly, there is a need to provide an improved device and method for restoring a flange of an engine part so as to overcome the disadvantages set forth of the presently known device.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of this invention to provide a method of restoring a flange which addresses the above-mentioned concerns.
[0007] In one aspect, the present invention provides a method of restoring a flange which has become distorted over time, the flange projecting at an angle from a component part, the method comprising the steps of: a) providing a support element on a first side of the flange, rolling a load applying element over a second opposite side of the flange with said support element reacting the compressive loads applied by said load applying element on said flange; and maintaining the angle between the flange and the component part during load application by way of the support element.
[0008] In another aspect, the present invention provides a method of restoring a flange extending at an angle from a part, the method comprising the step of: straightening out irregularities in the flange by pressing a roller against a first side of the flange while supporting an opposite side thereof to preserve said angle between the part and the flange when undergoing compression loading by way of said roller.
[0009] In another aspect, the present invention provides a method of flattening a circular radial flange, comprising the steps of: a) applying a flattening load to one side of the flange sequentially around a circumference of the flange, and b) providing a plurality of ring segments on an opposite side of the flange to oppose the flattening load.
[0010] In another aspect, the present invention provides a device for straightening out irregularities in a flange projecting at an angle from a part, comprising a roller for applying a flattening load against a first side of the flange, and a fixture for holding the part to be reworked, the fixture having a seat against which a second opposed side of the flange is supported to preserve the angle of the flange relative to the part while undergoing compression loading by way of said roller, said roller and said seat being relatively movable towards and away from each other, said roller being displaceable relative to said seat in a plane parallel thereto once pressed against the flange to apply a compressive load perpendicularly to the seat along the perimeter of the flange.
[0011] Further details of these and other aspects of the present invention will be apparent from the detailed description and figures included below.
DESCRIPTION OF THE DRAWINGS
[0012] Reference is now made to the accompanying figures depicting aspects of the present invention, in which:
[0013] FIG. 1 is a perspective assembled view of the flange restoring device operated to straighten a flange of an engine part to be restored in accordance with an embodiment of the present invention;
[0014] FIG. 2 is a schematic view of the flange restoring device shown in FIG. 1 ;
[0015] FIG. 3 is a perspective view of the engine part in a fixture on a rotary table forming part of the device shown in FIG. 1 ;
[0016] FIG. 4 is a perspective view of a plurality of torus segments being installed underneath the flange to be reworked;
[0017] FIG. 5 is a sectional view of one of the torus segments shown in FIG. 4 ;
[0018] FIG. 6 is a perspective view of a containment ring being installed about the torus segments;
[0019] FIG. 7 is a sectional view of the flange restoring device shown in FIG. 1 ;
[0020] FIG. 8 is a perspective view of a hand wheel being operated to position a load applying roller over the flange of the engine part to be reworked;
[0021] FIG. 9 is a perspective view of the control box of the flange restoring device in FIG. 1 ; and
[0022] FIG. 10 is a perspective view of a hydraulic hand pump of the flange restoring device in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] FIG. 1 illustrates a device 10 for restoring a flange 12 of a gas turbine engine part 14 , such as a turbine exhaust duct. It is understood however that the present flange straightening method could be used for straightening out irregularities in flanges of a wide variety of component parts. In an exemplary embodiment of the present invention shown in FIG. 2 , the engine part 14 is made up of a cylindrical body 16 and a bent circular radial flange 12 requiring straightening. In detail, the flange 12 has a rectangular cross section substantially perpendicular to the cylindrical body 16 as best illustrated in FIG. 2 . The flange 12 can be described as having a first surface 18 opposing a second surface 20 circumscribed by a perimeter 22 . In this particular case, the first surface 18 is the top surface while the second surface 20 is the bottom surface or underneath of the flange 12 . It should be noted that alternative flange configurations are also possible. For example, the flange 12 could have a conical cross section or could be circular yet discontinuous around the circumference of the cylindrical body 16 . Moreover, the device 10 could be designed to accommodate engine parts of varying shape without departing from its inventive nature.
[0024] Essentially, the device 10 restores the flange 12 by cold reworking it to its original form within given tolerances without the removal of material. As shown in FIG. 1 , the flange restoring device 10 includes an โHโ frame press 24 similar to any conventional press known in the art, which supports a hydraulic roller 26 movable for proper positioning with respect to the flange 12 by way of a hand wheel 28 ( FIG. 3 ). The device 10 further includes a hydraulic hand pump 30 (as best shown in FIG. 10 ) for generating a measurable amount of pressure required to straighten the flange 12 and a control box 32 ( FIG. 9 ) having a programmable logic controller (P.L.C.), a timer, failsafe cycle start controls and a power cut-off.
[0025] Referring to FIGS. 1 and 3 , a turn table 34 with a vertical central axis 36 ( FIG. 3 ) of rotation is also included as part of the device 10 for restoring the flange 12 . The turn table 34 must be durable for repeatedly withstanding high loads that need to be sustained in order to rework the flange 12 . The rotary table 34 is preferably electrically driven and controllable by the control box 32 .
[0026] The device 10 further includes a fixture 38 adapted for receiving the engine part 14 and for permitting the straightening of the flange 12 in both the radial and the axial directions through the use of a pressure applied by the hydraulic roller 26 as illustrated in FIG. 2 . More specifically, the fixture 38 as depicted in FIG. 3 receives the cylindrical body 16 such that a portion of the cylindrical body 14 with the flange 12 protrudes upwardly therefrom. The fixture 38 is securely mounted on the rotary table 34 . It is preferably centered about the central axis 36 of the rotary table 34 allowing for the center of the engine part 14 to align therewith upon insertion into the fixture 38 . By aligning the centers of the rotary table 34 , the fixture 38 and the engine part 14 a balance and stability is created, which is beneficial when load application is involved. As an exemplary embodiment, the fixture 38 is cylindrical for simplifying the inclusion of the cylindrical body 16 , the latter fitting snugly within the fixture 38 .
[0027] Referring now to FIGS. 2 , the device 10 also includes at least one seat or support element 40 for supporting the second surface 20 or underneath of the flange 12 to react the load on the first surface 18 applied by the hydraulic roller 26 during operation of the device 10 , as will be described in detail hereinafter. The fixture 38 is adapted to receive the support element 40 , acting as a base configured to mate with the latter.
[0028] In the illustrated embodiment, the support element 40 comprises a discrete number of torus or toroidal segments 42 (see FIGS. 4, 5 and 7 ). A primary feature of the torus segments 42 is that they permit for a flexible support of the flange 12 : yielding the flexibility required to bend the flange 12 in order to straighten it. More particularly, each torus segment 42 has the ability to flex or tilt towards or away from the central axis 36 of rotation and also expand in the tangential direction along the circumference of the cylindrical body 16 as the engine part 14 is rotated and the pressure is applied. In practice, the segments 42 themselves do not move outwards but rather (thru the use of an adequate lubricant) permit the flange 12 to slide across as required to straighten out the bends. Preferably, the torus segments 42 are spaced equidistantly around the circumference of the cylindrical body 16 as best illustrated in FIG. 4 . If the spacing between the torus segments 42 is too great the flange 12 may potentially bend in an unwanted form when loaded, particularly at the locations lacking support. Hence, by equally spacing the torus segments 42 the possibility of having a gap that exceeds the acceptable limit is avoided.
[0029] Referring concurrently to FIGS. 4, 5 and 7 , the torus segments 42 will now be described in detail. As depicted in the above-specified Figures, the torus segments 42 each include a core 44 with a radially outwardly protruding piece 46 attached thereto. The core 44 has a toroidal cross section (somewhat semicircular cross section) and can be further defined as having a flat top, a curved bottom, an inside and an outside surface 48 , 50 , 52 and 54 respectively. The protruding piece 46 , whose function will become clear later on, is attached to the outside surface 54 of the core 44 .
[0030] In this exemplary embodiment, the piece 46 is attached by way of being press fit and bolted into an aperture (not shown) present in the outside surface 54 of the core 44 and is preferably centered with respect to the outside surface 54 ( FIG. 7 ). However, it should be noted that alternatives attachment means and locations are also possible so long as the flexibility of the torus segments 42 is not hindered. Similarly, the shape of the protruding piece 46 can also vary. In this embodiment it is depicted as a cylindrical type piece, but other configurations could work as well.
[0031] Referring now particularly to FIGS. 5 and 7 , it can be seen that the bottom surface 50 of the core 44 has a convex curvature designed to sit atop the fixture 38 that has a matching concavity for receiving the bottom surface 50 . The top surface 48 of the core 44 is shaped to contact the second surface 20 or underneath of the flange 12 such that the top surface 48 is flush with the flange 12 . Hence, the core 44 is designed to achieve the greatest number of contact points possible with the flange 12 so as to maximize the support capabilities.
[0032] Furthermore, the inside surface 52 of the core 44 is also designed to mate with the portion of engine part 14 protruding from the fixture 38 as can be seen in FIG. 5 . In the illustrated case, the inside surface 52 has a slot 56 along the longitudinal axis of the core 44 to engage with a male feature of the cylindrical body 16 particular to the exemplified engine part 14 illustrated in FIGS. 4 and 7 . Notably, this is merely an example of the configuration of the core 44 as the engine part 14 requiring work can vary in shape. Thus, it can be stated that the core 44 is propitiously suited for engagement with the fixture 38 and the protruding engine part 14 so as to maximally support the flange 12 , whereby the support in mention is a flexible type of support.
[0033] In addition, FIGS. 4, 5 and 7 show the core 44 as having a bore 58 along its longitudinal axis. The bore 58 is adapted to receive a large O'ring to be threaded thru the segments 42 to keep them together as a unit. Bore 58 is optional only.
[0034] It should be understood that the engine parts to be reworked are analyzed on a case-by-case basis to determine the type of tooling required to yield the greatest efficiency. Thus, depending on the type of material and the nature of the rework requirements, a simple flat ring could be used instead of the torus segments 42 above-described to support the flange 12 .
[0035] Now referring concurrently to FIGS. 2, 6 and 7 , containment ring 60 included as part of the flange restoring device 10 is illustrated. The containment ring 60 is multifunctional in that it: acts to prevent the expansion by centrifugal force of the flange 12 in an outer radial direction after the engine part is loaded into the fixture, it serves to ensure that the torus segments 42 are equidistantly spaced, preventing an excessive gap at any one spot along the circumference of the cylindrical body 16 , and it also contains the segments 42 in the event of a catastrophic failure.
[0036] The containment ring 60 is adapted to engage the torus segments 42 upon installation thereby circumscribing the perimeter 22 of the flange 12 . In this exemplary embodiment, the containment ring 60 is provided in the form of a circular member having an inner side 62 and an outer side 64 defining a discrete number of downwardly open ended apertures 66 therebetween: The number of apertures 66 corresponds to the number of torus segments 42 each having a cylindrical protruding piece 46 . Particularly, the apertures 66 are of a U-shape so as to engage with the protruding cylindrical pieces 46 such that the latter slot into the apertures 66 upon proper positioning of the containment ring 60 .
[0037] Furthermore, upon installation of the containment ring 60 , the inner side 62 thereof comes into contact with the perimeter 22 of the flange 12 and the torus segments 42 ( FIG. 2 ). Notably, the containment ring 60 could alternatively be designed to additionally come into contact with the fixture 38 as best demonstrated in FIG. 7 .
[0038] Now referring concurrently to FIGS. 2 and 7 , a wear pad 68 of the type commonly known in the art is included to act as an intermediary load distributing element. The wear pad 68 ensures that the pressure applied by the hydraulic roller 26 to the first surface 18 of the flange 12 does not mark the engine part 14 and that the load is distributed evenly thereacross. The wear pad 68 is placed between the hydraulic roller 26 and the flange 12 on top of the first surface 18 of the flange 12 .
[0039] It is preferable that the wear pad 68 be at least as wide as the first surface 18 of the flange 12 to cover the entire flange 12 for protection. Also, for security purposes the wear pad 68 should abut the inner side 62 of the containment ring 60 as illustrated in FIGS. 2 and 7 . The wear pad 68 can be made of a variety of materials able to repeatedly withstand loading: steel being commonly utilized.
METHOD OF RESTORING A FLANGE OF AN ENGINE PART
[0040] The principal function of the flange restoring device 10 is to rework the flange of an engine part without the removal of material so that the engineering requirements for repair are met.
[0041] Firstly, the engine part 14 is properly inserted in the fixture 38 followed by the instalment of the support element 40 ( FIGS. 3 and 4 ). In the case where the torus segments 42 are utilized, they are each individually inserted between the underneath 20 of the flange 12 and the portion of the fixture 38 configured for mating therewith. Also, the torus segments 42 are positioned against the portion of the cylindrical body 16 protruding from the fixture 38 .
[0042] Next, the containment ring 60 is installed so as to sit on the radially protruding pieces 46 of the torus segments 42 by way of the U-shaped apertures 66 . The latter, being equidistantly spaced around the containment ring 60 ensure that the torus segments 42 are accurately placed and keep them in position ( FIG. 6 ).
[0043] Next, the wear pad 68 is installed over the flange 12 abutting the containment ring 60 to act as an intermediary load distributing element. The hydraulic roller 26 is then moved into position over the flange 12 by way of the hand wheel 28 ( FIG. 8 ). The hydraulic roller 26 is then lowered to come into contact with the wear pad 68 ( FIG. 1 ). At this point the controls in the control box 32 are activated appropriately ( FIG. 9 ). And finally a measurable amount of hydraulic pressure is manually applied by way of a hydraulic hand pump 30 ( FIG. 10 ). Pressures between 1000 to 1500 lbs are applied depending on the condition of the part to be reworked.
[0044] In restoring the flange 12 , the hydraulic roller 26 applies a force that is preferably perpendicular to the flange 12 as illustrated in FIG. 2 . The turn table 34 is electrically driven to rotate the engine part 14 about its central axis 36 at a constant speed, thereby causing the roller 26 to roll over the flange 12 .
[0045] As the force is applied sequentially around the circular radially flange 12 , the torus segments 42 provide a flexible support to the flange 12 throughout the reworking process. In further detail the torus segments 42 have the ability to individually tilt towards or away from the central axis 36 of rotation as they have a convex curvature that is seated on a concave portion of the fixture 38 . The segments 42 tilt to allow the flange 12 to slide across the flat surface on the top of the segments 42 . Thus, a flexible means of supporting the flange 12 is advantageous in reworking particular materials such as Inconel 600 or 625 that are very tough to work having been distorted by heat and hardened by repeated stresses.
[0046] The new method of restoring a flange of an engine part is advantageous in that a significant number of operations have been eliminated permitting to process engine parts within a controlled environment yielding improved results. Furthermore, engine parts can be processed within a given time frame while still reducing the overall cost of the rework thereby ensuring customer satisfaction. Moreover, the above-described method also ensures the safety of the employees.
The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without department from the scope of the invention disclosed. For example, the hydraulic roller could potentially be rotated around the flange rather than having the turn table rotates the engine part. In another example, the flange restoring device above described could be modified to accommodate engine parts and flanges of various shapes. In a further example, the entire process of restoring a flange could be automated thus eliminating the necessity of an individual applying pressure by a hydraulic hand pump or installing the torus segments and containment ring. Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.
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A method and a device for straightening out irregularities in a flange by pressing a roller against a first side of the flange while supporting an opposite side thereof to preserve the angle between the flange and the part when undergoing compression loading by way of the roller.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to protection against terrorist bombing of aircraft and in particular to construction of aircraft and luggage facilities for directing explosive forces from bombs out of cargo holds safely and inexpensively without occurrence of injury to passengers or debilitating damage to aircraft.
2. Relation To Prior Art
Terrorist bombing of aircraft is proliferating in present world conditions. An effective and relatively inexpensive protection of passengers and aircraft against potential harm from luggage-borne bombs is critical. It can discourage their use in addition to protecting passengers and aircraft.
Solutions to date have included bomb-detection systems and explosion-containment systems. None have provided construction of aircraft and cargo facilities to direct explosive forces out of aircraft without occurrence of injury to passengers or debilitating damage to aircraft in a manner taught by this invention.
The most nearly related devices and systems known are those directed at containing explosive forces within aircraft. Examples of these different but related devices for differently protective systems are described in the following patent documents.
U.S. Pat. No. 5,360,129, issued to Lee, described an explosion-containment luggage container with explosive-containment construction on all but one or more weak faces through which explosive forces could be directed against a section of aircraft hull. There was no provision for construction of aircraft to allow escape of the explosion forces without flight-debilitating damage. U.S. Pat. No. 5,267,665, issued to Sanai et al taught an explosion-resistant luggage container that deformed spherically to aid in absorbing explosion pressures and explosion debris. Neither of these explosion-containment devices have been adequate. Luggage bombs and fear of their use continue to proliferate.
SUMMARY OF THE INVENTION
In light of need for a better system of protection against luggage-bombing of aircraft, objects of this invention are to provide an aircraft-luggage-bomb protection system which:
Directs explosion pressure and particles from aircraft-luggage bombs out through blow-away plugs in walls of airplanes;
Allows aircraft to be operated safely after in-flight detonation of luggage bombs planted by terrorists;
Provides quick and optionally automatic in-flight replacement of blow-away plugs;
Limits a luggage-bomb explosion to a single luggage-cart portion of an aircraft cargo hold;
Prevents in-flight explosion of luggage bombs from having a debilitating effect on either aircraft or aircraft passengers;
Is more effective and costs less to implement than other luggage-bomb-protection systems;
Can be implemented quicker than other systems of protection against luggage bombing;
Does not require development of untried and unknown protective systems;
Is less vulnerable than other systems to human error and ability of airline employees;
Minimizes criticality of luggage-bomb detection at airports; and
Can be used in combination with luggage-bomb detection as desired.
This invention accomplishes these and other objectives with an aircraft-luggage-bomb protection system having a blow-away plug for each of a plurality of luggage-storage units of a cargo hold of a commercial airplane. Luggage is placed in explosion containers that are positioned over the blow-away plugs. The explosion containers can be structured for select handling equipment such as luggage carts and pallets. The cargo holds are structured for quick and easy conversion between passenger use and airfreight use of planes. Procedural methods are provided.
BRIEF DESCRIPTION OF DRAWINGS
This invention is described by appended claims in relation to description of a preferred embodiment with reference to the following drawings which are described briefly as follows:
FIG. 1 is a partially cutaway perspective view of an airplane having blow-away plugs and a rail system for positioning explosion containers on luggage carts;
FIG. 2 is a partially cutaway section view of a cargo hold of an airplane in which explosion containers on luggage carts are positioned on blow-away plugs;
FIG. 3 is a partially cutaway top view of an explosion container on a cart with retractable wheels;
FIG. 4 is a side view of the FIG. 3 illustration with a pressure-containment door hinged open;
FIG. 5 is a partially cutaway sectional view of a side of a cargo hold over which an explosion-containment shell is positioned over a blow-away plug with hinged doors on a bottom of an airplane;
FIG. 6 is a partially cutaway sectional view of a side of a cargo hold over which an explosion-containment shell is positioned over a blow-away plug having a cross-sectional area approximately equal to a cross-sectional area of an entry to the explosion-containment shell;
FIG. 7 is a side elevation view of a stack of explosion-containment shells;
FIG. 8 is a top view of either a single or a stack of explosion-containment shells;
FIG. 9 is a partially cutaway side view of an explosion-containment shell attached to a loaded luggage pallet and being handled from a top by a lift vehicle;
FIG. 10 is a partially cutaway side view of a loaded luggage pallet positioned to be covered with an explosion-containment shell and being bottom-handled with a lift vehicle; and
FIG. 11 is a partially cutaway top view of a luggage pallet.
DESCRIPTION OF PREFERRED EMBODIMENT
Reference is made first to FIGS. 1-2. Blow-away plugs 1 are positioned in line with an entry to explosion containers 2 in which luggage 3 is placed in a cargo section 4 of an airplane 5. The explosion containers 2 are structured and positioned to contain explosion pressure from a detonated luggage bomb while directing explosion pressure to the blow-away plug 1. The blow-away plug 1 is structured and positioned to be opened designedly by explosion pressure from a detonated luggage bomb in the cargo section 4 of the airplane 5, such that explosion pressure from a detonated luggage bomb in luggage 3 is contained by the explosion container 2 while the explosion pressure opens a wall section 6 and a surface section 7 of the blow-away plug 1.
Referring to FIGS. 1-4, the explosion containers 2 can be luggage carts 8 on wheels 9 which can be retractable and can be structured to run on rails 10 to be positioned over the blow-away plugs 1. Explosion containers 2, such as luggage carts 8, are fastened to a floor wall 11 with preferably a pressure-containment fastener 12 that is spring-loaded with a recoil spring 13 having spring force positioned in resistance to increase in distance intermediate a connection of the pressure-containment fastener 12 to the floor wall 11 and a connection of the pressure-containment fastener 12 to the explosion container 2 at a top of the luggage cart 8.
The recoil spring 13 absorbs explosive shock of initial peak pressure of explosion. This decreases required pressure-resistance and resulting weight of the explosion container 2 such as the luggage cart 8.
An explosion-escape chute 14 can be employed to provide communication of explosion pressure with an easy escape to the blow-away plug 1 from a luggage bomb in luggage 3 at any position within the explosion container 2. Grillwork 15 or other porous or easily breakable wall on the explosion-escape chute 14 can be employed to keep luggage 3 from clogging the explosion-escape chute 14.
Explosion pressure of expanding gas from a bomb expands spherically outward initially but follows least lines of resistance that may exist. A least line of resistance that is sufficiently large and free-flowing in a single direction can cause a flow of gas pressure in that single direction. The flow of gas pressure in such a single direction can diminish pressure in other directions to a point of negative or near-negative pressure in some explosion-containment conditions. An adequately quick, easy and large escape route is provided by the explosion-escape chute 14 and the blow-away plug 1 for this embodiment.
The wall section 6 of the blow-away plug 1 can be a circular plate that is seal-fastened with an O-ring 16 in a plug aperture 17 that is cylindrical at a connection perimeter and adequately reinforced. Fluidly downstream from the connection perimeter, the plug aperture 17 can be enlarged with a desired geometrical form to allow the wall section 6 of the blow-away plug 1 to travel without restriction from friction contact of the O-ring 16 with an internal periphery of the plug aperture 17. Shatter connections can be provided in lieu of the O-ring 16 and the wall section 6 also can be disintegrative in order to minimize obstruction of gas flow and to facilitate gas flow to the surface section 7 of the blow-away plug 1.
The wall section 6 of the blow-away plug 1 can be shatter-attached, hinged or attached otherwise to the airplane 5 in a manner that allows the wall section 6 to open or to be removed quickly and easily enough to facilitate directional flow of gas pressure from a detonated luggage bomb.
A pressure-containment door 18 with pressure fasteners 19 can be hinged to the luggage cart 8 to allow bomb-sealed placement and removal of luggage 3.
Referring to FIG. 5, the explosion container 2 can be an explosion-containment shell 20 with unitary construction, rounded corners, tapered walls and a domed top 21 to minimize weight per strength and to maximize effectiveness of directing explosion pressure in a single direction of flow towards a container entry 22. The luggage 3 can be stacked on a luggage pallet 23 having a center section 24 that is designedly open or openable above a wall section 6, a surface section 7 and a plug aperture 17 of a blow-away plug 1.
A shell-fastener means such as a fastener flange 25 on a bottom of the explosion-container shell 20 and a spring-loaded fastener bolt 26 in design pluralities can be provided to seal-fasten the explosion-container shell 20 to the floor wall 11 of the cargo section 4. With the explosion-container shell 20 seal-fastened to the floor wall 11, the center section 24 of the luggage pallet 23 can be used either in place of or in combination with the wall section 6 of the blow-away plug 1. The wall section 6 depicted for use with this embodiment is rectangular and has disintegrative fasteners 27 to a rectangular plug aperture 17.
An explosion-escape chute 14 with grillwork 15, as described in relation to FIGS. 2-4, is preferable for use with a center section 24 of the luggage pallet 23.
A surface section 7 of the blow-away plug 1 can be hinged with plug hinges 28 to the plug aperture 17 or to the airplane 5 proximate a bottom portion of the plug aperture 17. The plug hinges 28 and oppositely disposed walls of the surface section 7 are preferably parallel or substantially colinear to flight axis of the airplane. Wall actuators 29 can be employed to pivot the surface section 7 back to normal after a luggage-bomb explosion has expelled contents of the explosion-containment shell 20 or other explosion container 2 out of the airplane 5 through the blow-away plug 1. The wall actuator 29 can be operated with a torsion spring automatically or with hydraulic, pneumatic or mechanical means in accordance with design preferences.
An airplane 5 can continue flight without debilitative effect of a luggage bomb when the surface section 7 is closed and an explosion container 2 such as an explosion-containment shell 20 or a luggage cart 8 are seal-fastened to a floor wall 11.
Referring to FIG. 6, an entire luggage pallet 23 and its contents can rest on pressure-release latches 30 in line with a full-pallet plug aperture 31 and a full-pallet surface section 32. This provides full-pallet release that obviates need for an explosion-escape chute 14. The pressure-release latches 30 and a full-pallet surface section 32 can be pressure-sensitive to open and jettison the luggage pallet 23 and its contents with a designedly small fraction of explosion pressure from a detonated luggage bomb. Seal-fastening of the explosion-containment shell 20 to the floor wall 11 also obviates need for a wall section 6 in a blow-away plug 1. Passengers might not notice explosion of a luggage bomb as an airplane 5 continued on in flight.
Referring to FIGS. 7-11, tapered structure of an explosion-containment shell 20 allows a plurality of them to be stacked telescopically as depicted in FIG. 7. An explosion-escape chute 14 depicted by dashed lines in FIG. 8 is optional, depending on the type and size of blow-away plug 1 employed as described in relation to FIGS. 2 and 5-6.
A luggage pallet 23 can have a gate 40 in pallet walls 33 for loading luggage 3. The lift apertures 38 can be extended from-side-to-side as shown or partway through in accordance with the type of lifting mechanism employed. For using a boom 35 type of lift, the lift apertures 38 need only extend inwardly far enough to contain pressure-release fasteners 39. For versatility allowing use of either tines 37 or a boom 35, the lift apertures 38 can be extended from-side-to-side as shown. If employed, an explosion-escape chute 14, described in relation to FIGS. 2-3 and 5-6, can have a grillwork 15 on top as well as on sides to keep out luggage.
To use the explosion-containment shell 20, luggage 3 can be placed within pallet walls 33 on a luggage pallet 23. Then an explosion-containment shell 20 is positioned on the luggage pallet 23 as shown completed in FIG. 9 and in process in FIG. 10. If the luggage-containment shell 20 is fastened securely to the luggage pallet 23, a loaded luggage pallet 23 can be top-carried from a shell handle 34 with a boom 35 on a mobile lifter 36 as depicted in FIG. 9. If the explosion-containment shell 20 is not fastened securely to the luggage pallet 23, a loaded or unloaded luggage pallet 23 can be carried with tines 37 of a mobile lifter 36 inserted in lift apertures 38 in the luggage pallet 23. Optional to a motorized mobile lifter 36 depicted in FIG. 10 for lifting and moving a loaded or unloaded luggage pallet 23 not fastened to an explosion-containment shell 20 can be a hand-operative or walk-along lift that is not shown. Attachment of the explosion-containment shell 20 to the luggage pallet 23 can be accomplished with pressure-release fasteners 39 that can be used in lieu of or in combination with pressure-release latches 30.
A new and useful aircraft-luggage-bomb protection system having been described, all such foreseeable modifications, adaptations, substitutions of equivalents, mathematical possibilities of combinations of parts, pluralities of parts, applications and forms thereof as described by the following claims and not precluded by prior art are included in this invention.
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An aircraft-luggage-bomb protection system has a blow-away plug (1) for each of a plurality luggage-storage units of a cargo section (4) of a commercial airplane (5). Luggage (3) is placed in explosion containers (2, 8, 20) that are positioned over the blow-away plugs. The explosion containers can be structured for select handling equipment such as luggage carts and pallets (23). The cargo sections are structured for quick and easy conversion between passenger use and airfreight use of planes. Procedural methods are provided.
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BACKGROUND OF THE INVENTION
The present invention relates to a brake control device for a bicycle, and more particularly, to a brake control device mounted to what is commonly referred to as the drop-type handle bar which has a straight rod section and at opposite ends of the rod section a pair of U-like shaped bent rod sections. The brake control device commonly used with a drop-type handle bar generally has a main lever for actuating the brake while the rider is gripping the bent rod sections and an auxiliary lever which is positioned so that a rider may grasp the brake control device while gripping the straight rod section of a handle bar.
The brake control device is mounted to a bent section of the handle bar by a bracket which is positioned to provide access to the main and auxiliary levers of the brake control device.
The brake control device described as above is fixed to the handle bar by the bracket and thereafter the distances between the main and auxiliary levers and opposite handle bar portions is fixed; that is, the rider cannot adjust the distances between the handle bars and the main and auxiliary levers.
Even when the mounting bracket of the brake control device is set to be fixed at a desired position on the handle bar so as to provide suitable distances between the main and auxiliary levers and the corresponding handle bar sections to provide an easy gripping of the levers, different drop-type handle bars and different mounting positions of the brake control device bracket causes great changes in the lever to handle bar distances, especially the distance between the auxiliary lever and the straight portion of the handle bar. Thus, it has been difficult with conventional brake control devices to keep suitable distances between the main and auxiliary levers under various conditions.
Moreover, even if a proper distance is selected for a standard drop-type handle bar, the conventional brake control device cannot be adjusted so that the distance between main and auxiliary levers and handle bars fits the size of a rider's hand or his particular preference. Accordingly, it has been impossible with conventional brake control devices to conform the brake gripping distance, i.e., the distance between handle bar and brake lever, to every rider.
The present invention has been designed to overcome the foregoing problems. A main object of the invention is to provide a brake control device for a bicycle which is capable of having the distance between the main and auxiliary levers and corresponding sections of the handle bar adjusted, particularly that distance between the auxiliary lever and a corresponding section of the handle bar opposite thereto which heretofore has been very difficult to adjust satisfactorily.
Another object of the invention is to provide a brake control device for a bicycle in which the distance between the main lever and a corresponding section of the handle bar can be adjusted.
The foregoing objects have been achieved by providing a brake control device in which the main and auxiliary levers are pivoted to the bracket which fixes the brake control device to a handle bar, with the main and auxiliary levers being swingable independently of one another. A wire hook which is integral with the auxiliary lever swings in association therewith and is also mounted to the bracket, the wire hook retaining one end of a control wire whose other end is connected with the bicycle brake. The main lever is provided with an engaging member which, when the main lever is controlled, engages with the wire hook causing it to swing. An adjust bolt is provided between the wire hook and engaging member for adjusting the relative position of the main lever to the wire hook which causes an adjustment in the grip dimension between the auxiliary lever and the straight section of the handle bar opposite thereto.
The main lever is provided with an adjusting member which is controllably movable towards a front wall of the bracket which causes an adjustment in the grip dimension between the main lever and bent rod section of the handle bar opposite thereto.
Both the adjust bolt and adjusting member can be controlled in combination so that the extension of the brake control wire and contraction of an outer sheath thereof may be adjusted without changing dimensions between the grips of the main and auxiliary levers and the handle bars. In addition, the adjust bolt can be utilized to loosen the control wire to expand the distance between brake shoes controlled by the brake control device. Thus, even when used with a caliper brake, the adjust bolt can facilitate removal of the bicycle wheel from between the brake shoes.
These and other objects and novel features of the invention will be more apparent from the following description of the invention taken in conjunction with the accompanying drawings which show one embodiment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of the brake control device of the invention attached to a drop-type handle bar,
FIG. 2 is a partially cutaway side view of the embodiment of the brake control device of the invention,
FIGS. 3 and 4 illustrate an adjustment of the distances between the grips of the main and auxiliary levers and the handle bar portions corresponding thereto,
FIG. 5 is an enlarged sectional view taken on the line V--V in FIG. 2, and
FIG. 6 is a sectional view taken on the line VI--VI in FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, numeral 1 designates a bracket having a clip band 2 attached thereto for attaching the brake control device of the invention to a handle bar. The bracket 1 comprises a pair of side walls 1a and 1b which have respective shaft bores, a front wall 1c and a rear wall 1d . A support 3 is fixed between the side walls 1a and 1b through which a screw 4 is screwed and tightened at its tip to a washer 21 attached to both ends of the clip band 2. Screw 4 cooperating with washer 21 and support 3 serves to positively clamp bracket 1 to the handle bar A.
Handle bar A comprises a straight rod section b and a pair of U-like shaped bent rod sections a at both ends thereof. Each of the bent rod sections a carries a respective bracket 1 although only one of the bent rod sections a carrying a single bracket 1 is shown in FIG. 1.
An auxiliary lever 5 is pivotally supported between both side walls 1a and 1b of the bracket 1 through bushings 6 and 6a . The auxiliary lever is formed as a pipe and has a grip 5a and a head 5b which forms a spindle. The grip 5a and head 5b are connected with a trunk at right angles, the head 5b being directed in parallel reversely to the grip 5a, the grip in turn being arranged in parallel to the straight rod section b of the handle bar A.
The head 5b of the auxiliary lever 5 is axially larger than an interval between the side walls 1a and 1b of bracket 1 and projects through bores provided in the side walls. Head 5b is also elliptic in section as shown in FIGS. 2 and 6. Bushings 6 and 6a are provided in the respective bores of the side walls 1a and 1b and have an internal elliptic shape to fit the head 5b of the auxiliary lever 5 and a round external periphery to fit the bores. With this construction, the head 5b is inserted into the bushing 6 and 6a such that it is non-rotatable while the auxiliary lever 5 is swingably supported to the bracket 1 through the bushings 6 and 6a. The elliptic cross section of head 5b also serves to non-rotatably support a wire hook as further described below.
Bushing 6 has a flange 61 and a stem 62 as a continuation of the flange. Flange 61 abuts against the outer side of the wall 1b and the stem 62 is inserted into the head 5b and is radially perforated at an intermediate portion thereof with the set screw 7 which locks the auxiliary lever 5 against slipping out of bracket 1.
A main lever 8 is provided with a grip 8a and a mounting portion 8b as shown in FIG. 5. The grip 8a is opposite to the bent portion section a of handle bar A and the mounting portion 8b is U-like shaped in section. The mounting portion 8b also has, at both opposite side walls thereof, bores through which the main lever 8 can be inserted onto the bushings 6 and 6a thereby being pivoted within the bracket 1. The mounting portion 8b also has at the inner surface of a top wall thereof a first engagement 82 of ratchet teeth the purpose of which will be described in more detail below. At a substantially intermediate portion of the opposite walls of the mounting portion 8b an engaging member 83 is provided in engagement with a wire hook 9.
Wire hook 9 serves to hook an end piece of one end of a brake control wire which is connected at its other end to the brake and has a base 9a and an end hook 9b . The base 9a is provided with an elliptic bore 91 which fits onto the elliptic head 5b of the auxiliary lever 5, the base 9a being supported to the head 5b at an axially intermediate portion thereof. Thus, rotative movement of head 5b of the auxiliary lever causes swinging movement of wire hook 9 in association therewith. Set screw 7 prevents wire hook 9 from moving axially with respect to the auxiliary lever while wire hook 9 holds at the end hook 9b the end 20 of the brake control wire W. The control wire W is encased with a sheath K and an outer sheath stop 15 is provided which abuts against the front wall 1c of bracket 1.
The wire hook 9 is engaged at its intermediate side edge with the engaging member 83 provided on the main lever 8, thereby being movable in association with movement of the main lever. Thus, when a rider grasps the grip 8a of a main lever 8 to initiate braking action, wire hook 9 is rotated through the engaging member 83 abutting thereagainst so as to pull the control wire W connected with the brake. On the other hand, when a rider releases the main lever 8, the return spring of the brake pulls the wire W causing the wire hook 9 to rotate back and return the main lever 8 to its rest position.
An adjust bolt 10 which is screwably movable toward the engaging member 83 is screwed to the wire hook 9 at a substantially intermediate portion thereof. The bolt 10 abuts at its tip against engaging member 83. Thus, screwing movement of the bolt 10 causes an adjustment in the relative position of the main lever 8 to the wire hook 9, whereby auxiliary lever 5 is moved to adjust the distance or grip-dimension D1 between the grip 5a of the auxiliary lever and the section of the handle bar A opposite thereto. A locking spring 14 is provided for the adjust bolt 10.
An adjusting member 11 having an abutment 11a contacting the front end of the front wall 1c of bracket 1 is attached to the main lever 8 so as to be movable with respect thereto. The adjusting member 11 is U-like shaped in section as shown in FIG. 5 and is fit to the outside of a guide slide 81 provided in a top portion of main lever 8 while being mounted to the main lever 8 through a control member 12 the latter being supported movably to the adjusting member 11.
The control means 12 has a second engagement element 12a in mesh with ratchet teeth provided on a first engagement element 82. Control means 12 also has a control body projecting outwardly of the second engagement element 12a through the slot 81 and the adjusting member 11, as well as a spring 13 inserted between the control body 12b and the adjusting member 11. Spring 13 always urges the second engagement element 12a into mesh with the first engagement element 82. The control body 12 is pushed against the spring 13 to cause disengagement of the second engagement element 12a from the first engagement element 82 to thereby allow adjusting member 11 to slide with respect to the main lever 8 to adjust the distance or grip-dimension D2 between the grip 8a and a corresponding section of the handle bar A. The adjustment of the grip-dimensions betwen the main and auxiliary levers of the brake control device and the handle bar A will now be described. When a distance D1 between a grip 5a of the auxiliary lever 5 and the straight rod section b of the handle bar A is too long to fit a riders hand, the adjust bolt 10 is screwed forward to move the wire hook 9 apart from the engaging member 83 as shown in FIGS. 2 and 3 to thereby adjust the relative position of the main lever 8 to the wire hook 9. This adjustment causes the auxiliary lever 5 to turn clockwise thereby shortening the distance D1.
On the other hand, when the distance D1 is too short, the adjust bolt 10 is reversely rotated to adjust the relative position of the auxiliary lever relative to the handle bar A. In this instance, the auxiliary lever 5 is rotated counterclockwise as shown in FIGS. 3 and then 2.
When a distance D2 existing between a grip 8a of the main lever 8 and the bent rod section A is too long to fit a rider's hand, the control means 12 is pushed against spring 13 to disengage the second engagement element 12a from the ratchet teeth of the first engagement element 82. This allows the adjusting member 11 to slide apart from the main lever 8 toward the front wall 1c of the bracket 1 as shown in FIG. 4 whereby the main lever 8 is turned clockwise from the position shown in FIG. 2 to thereby shorten the distance D2 as desired.
When the distance D2 is too small, the control means 12 is pushed against the spring 13 to again disengage the second engagement element 12a from the ratchet teeth of the first engagement element 82 while the adjusting member is slid to approach the main lever 8 causing the main lever 8 to be turned counterclockwise as shown in FIG. 4. As a result, the distance D2 is increased to fit a rider's hand as illustrated in FIG. 2.
The brake control device of the present invention also allows for an adjustment in the relative position of the main lever 8 to the wire hook 9 through the adjust bolt 10 thereby adjusting the extension of the control wire W and contraction of its outer sheath K.
In addition, when the wire hook 9 has been rotated clockwise to a predetermined large extent, the adjust bolt 10 may then be screwed backward to turn the wire hook 9 counterclockwise to loosen the control wire W thereby facilitating a quick removal of the wire from its associated wire hook 9. Also, when the device is used with a caliper brake, the brake shoes can easily be widened to increase the interval therebetween by loosening the wire in this manner thereby facilitating removal of the bicycle wheel from between the brake shoes.
As the foregoing description clearly demonstrates, the brake control device of the invention is very simple in construction yet it achieves a relatively easy adjustment in the grip distances between the main and auxiliary control levers and the handle bar. The construction includes a wire hook retaining one end of a brake control wire integrally mounted to the auxiliary lever and moving in association therewith and an adjust bolt provided for adjusting the relative position of the main lever to the wire hook. Movement of the adjust bolt achieves an easy adjustment of the distance between the auxiliary lever and corresponding section of the handle bar opposite to its grip. As a result, the control device, even when attached to various drop-type handle bars other than of standard size or shape, is capable of being adjusted so that every rider may easily grip the auxiliary lever positioned at a suitable distance from the handle bar. Because of the simplicity of its construction, the control device is also inexpensive to produce.
The adjust bolt also serves to adjust the relative position of the main lever to the wire hook to cause an extension of the control wire and contraction of its outer sheath to be adjustable without changing the distance between the lever and handle bar. Also, the brake shoes can be renewed very quickly and readily removed from the bicycle because of the decreased tension in the control wire.
The invention also employs an adjusting member mounted movable with respect to the main lever which provides the brake control device with an adjustment of the distance between the grip of the main lever and a corresponding opposing section of the handle bar.
While the preferred embodiment of the invention has been shown and described above, the invention is not limited to this specific construction described and illustrated. This construction is to be considered as merely exemplary of the invention which is limited solely by the attached claims. cm What is claimed is:
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A brake control device for a bicycle is disclosed having main and auxiliary levers which are pivoted to a bracket fixed to the handle bar of a bicycle. The levers are mounted to be swingable independently of one another to swingingly move a wire hook which is integral with the auxiliary lever and which anchors one end of a brake control wire. The main lever is provided with an engaging member for swinging the wire hook upon main lever operation and between the engaging member and wire is provided an adjusting bolt for adjusting the relative position of the wire hook and engaging member. Adjustment of the adjusting bolt controls the distance between the grip portion of the auxiliary lever and the portion of the handle bar opposite thereto. An adjustment of the distance between the main lever and the portion of the handle bar opposite it can also be effected through the provision of an adjustable ratchet mechanism provided in association with the main lever.
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This application is a division of application Ser. No. 945654, filed 12/23/86 now U.S. Pat. No. 4,242,331.
FIELD OF THE INVENTION
This invention relates to reset circuitry for resistance capacitance voltage ramp generators.
BACKGROUND OF THE INVENTION
In modern computer control systems, it is frequently necessary to reset convert a digital signal (which is used internally in the computer) to a variety of analog signals which are used to directly control or measure the environment. Two conversion devices which are ofter used in manufacturing systems are digital-to-analog converters (DACs) and analog-to-digital converters (ADCs). These units convert between analog signals generated by the environment and the digital signals used by the computer.
Another, perhaps less widely used, conversion device is a digital-to-time converter. This unit accepts a digital signal and produces a proportional time delay. The delay usually appears as a time difference between two pulses appearing at the output of the device or between a trigger pulse and a pulse appearing at the output of the device. Such programmable time delay circuits are often used in automated test equipment and are used to delay digital signals.
Digital-to-time converters have conventionally been fabricated from discrete semiconductor devices. In such devices, the conversion is often performed by comparing a linearly-increasing voltage or current ramp signal to a threshold voltage or current. In one conventional form of a digital-to-time converter, a fixed threshold voltage is set by a precision voltage reference source and the time delay is generated by comparing the threshold voltage to a ramp with a variable slope. The slope of the ramp is set by the value of the digital word to program the device. In another conventional form of the converter, a ramp with a fixed slope is generated and the time delay is obtained by comparing the ramp voltage to a variable threshold whose level is set in accordance with input digital word.
In either of the above variations, when the value of the ramp voltage equals the value of the threshold voltage a pulse signal is generated. If a pulse signal is generated at the start the ramp signal, the time elapsing between the two pulse signals represents a delay which depends on the value of the digital input word. The starting pulse may also be the trigger pulse which is used to start the ramp signal generation.
In a conventional digital-to-time converter designed with discrete devices, the internal ramp signal is created by charging a capacitor with a stable current generated by placing a precision voltage reference source across a precision resistor. Once a stable charging current has been established, the voltage across the capacitor provides a stable ramp output.
Such a ramp generator is usually reset by means of a shorting transistor connected in shunt across the capacitor. When the shorting transistor is turned "on", the voltage across the capacitor is returned to zero, resetting the circuit. The shorting capacitor is normally controlled by the output of a flip-flop or other memory circuit which determines whether the circuit is operational or rest in response to the application of set or reset signals.
The problem with the conventional arrangement is that the reset signal which operates the flip-flop must propagate through the flip-flop to turn on the shorting transistor and reset the circuit. Since the flip-flop contains many transistors and other elements, the time consumed between the receipt of a reset signal at the flip-flop input and the actuation of the shorting transistor is usually significant and thus the reset time of the entire circuit is increased by the propagation delay of the flip-flop. Since the reset time of the circuit is a substantial portion of the operating cycle of the circuit, the entire operational frequency is reduced.
Accordingly, it is an object of the present invention to provide a reset circuit for a ramp generator which can operate at high speed.
It is another object of the present invention to provide a reset circuit for a ramp generator in which the reset function operates at a higher speed than conventional circuits.
It is yet a further object of the present invention to provide a reset circuit for a ramp generator which can be easily fabricated in a monolithic integrated circuits.
It is yet a further object of the present invention to provide a reset circuit for a ramp generator which can be easily intergated with existing control circuitry.
SUMMARY OF THE INVENTION
The foregoing objects are achieved and the foregoing problems are solved in one illustrative embodiment of the invention in which a current switch is connected to the shorting transistor. The current switch is directly actuated by a reset signal and immediately diverts current to the shorting transistor causing the circuit to reset. The current switch holds the circuit in the reset condition until the flip-flop changes state in order to maintain the circuit reset.
More particularly, the shorting transistor is connected to a bias circuit which normally provides base current to turn the transistor "on". During circuit operation, in order to hold the shorting transistor "off", the shorting transistor base current is drawn away from the shorting transistor by means of a control transistor which is located in the output circuitry of the flip-flop. The control transistor acts as a current switch to divert the shorting transistor base current to ground.
In accordance with the invention, a second current switch is connected in series with the control transistor. This second current switch is directly responsive to a reset signal applied to the circuit. When a reset signal is applied, the second current switch opens and allows the bias circuit to immediately apply base current to the shorting transistor. The shorting transistor thereupon turns "on" and resets the circuit. Subsequently, the flip-flop changes state to maintain the circuit in the reset state.
In order to allow the reset circuitry to be fabricated as a monlithic integrated circuit, both the control transistor and the second current switch are fabricated as pair of emitter-coupled transistors connected to a current source. This conventional arrangement allows current to be switched between circuit elements without changing the overall current flow through the system.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block schematic diagram of the inventive digital-to-time converter circuit.
FIG. 2 is a detailed electrical schematic diagram of the trigger/reset flip-flop circuitry.
FIG. 3 is a electrical schematic diagram of the ramp generator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An illustrative digital-to-time converter has a TRIGGER input, a RESET input, a minimum delay output and a programmed delay output. The TRIGGER input accepts a positive-going-edge signal to trigger the circuit. Internal circuitry prevents an erroneous re-triggering until the circuit function has been completed. After the circuit has been triggered, and after a propagation delay, a pulse appears at the minimum delay output. This pulse is used in the same fashion as analog ground in a digital-to-analog converter to reference the zero state (zero time delay in the present circuit). Subsequently, after a programmed time delay depending on the values of the digital input word (on leads B1-B8), a second pulse appears at the programmed delay output. The time elapsing between the two pulses represents the time delay generated by the device. The RESET input is dominant over the TRIGGER input. In the presence of a RESET input the device cannot be triggered and, if already triggered, it resets.
More particularly, as shown in FIG. 1, the device accepts a differential, or single-ended, emitter-coupled-logic (ECL) signal applied to its TRIGGER input 100. The TRIGGER signal on lead 100 is applied to input and ramp start circuitry 106. Upon a rising edge being detected, the ramp start circuitry controls the charging of capacitor 120 which, as will hereinafter be described, generates the ramp voltage used to generate the programmed time interval.
Circuitry 106 also responds to signals on the RESET leads 108, but contrary to the operation of the TRIGGER portion of the circuit, circuit 106 is designed to be sensitive to the level of the RESET signal rather than the signal edges. When a "high" RESET signal is applied to the RESET leads 108, the charging of capacitor 120 is terminated and the circuit is reset regardless of the state of the TRIGGER inputs or the state of the circuit.
When the ramp start circuitry is activated, it removes the base drive signal on lead 114 which is normally applied to transistor 116 (transistor 116, in the quiescent state, is normally "on" and short circuits timing capacitor 120). However, when the ramp start circuitry is activated, it applies a "low" signal to the base of transistor 116 which turns "off" the transistor. Capacitor 120 then begins charging from VCC, 118, through voltage coupling circuit 122 and resistor 124.
As will be hereinafter described in detail, circuit 106 is designed to accelerate the turn-on of transistor 116 when a reset signal is sensed so that the reset time of the circuit is minimized. Since the reset time is an appreciable part of the overall cycle time, high-speed operation is facilitated.
The voltage across capacitor 120 is compared, by comparator 138, to a minimum delay voltage to generate the minimum delay output. The minimum delay voltage is generated across resistor 117. The voltage appearing across resistor 117 is determined by the voltage coupling circuit 122 which will be described in detail below. In the quiescent state of the circuit, a current source, 127, create an "offset" that maintains the output comparator 138 in an "off" state to avoid an indeterminate state at the output. However, as capacitor 120 charges, the voltage across it quickly exceeds the offset voltage and comparator 138 shifts to a "high" MDO signal indicating a minimum propagation delay through the device. As previously mentioned, the "high" MDO signal can be used as a zero-time reference in a manner similar to the use of analog ground as a zero-voltage reference for a conventional digital-to-analog converter.
The voltage across capacitor 120 increases as the capacitor charges and, eventually, generates a programmed delay output (PDO) signal. The PDO signal on leads 134 is generated by comparator 132 which has inputs 135 which are, in turn, connected to timing capacitor 120 and to a threshold circuit which comprises DAC 128 resistor 119 and current source 127.
DAC 128 accepts TTL signals representing a digital word on its inputs 130. This digital word is latched into converter 128 by means of a level-sensitive latch signal appearing on lead 131. The DAC effectively appears as a plurality of parallel-connected, binary-weighted current sources 129. In response to the digital word, converter 128 connects these current sources either to supply voltage 118 or resistor 119. The current running through each of the parallel sources is determined by components in the DAC and in voltage coupling circuit 122 so that the total DAC current is independent of the digital word. The portion of the current running through the resistor 119 is determined by the value of the digital word and is also proportional to the total DAC current since it is comprised of the current running through selected ones of the parallel-connected sources. The current running through resistor 119 causes a threshold voltage to develop at point 125, the value of which is dependent on the combination of current sources connected to resistor 119, which combination is, in turn, dependent on the value of the digital word and on the total DAC current.
The total current running through the DAC is determined by internal DAC components, components in voltage coupling circuit 122 and resistor 126. In particular, the DAC current runs through reference resistor 126 to create a reference voltage VA, and, accordingly, the voltage VA is representative of the changes in the DAC current caused by thermal and supply variations. Since the current running through the resistor 119 is proportional to the total DAC current, the threshold voltage appearing across resistor 119 is proportional to the reference voltage VA and variations in the threshold voltage caused by thermal and supply variations are represented by variations in the reference voltage VA.
Voltage coupling circuit 122 is arranged to force the voltage, VB, appearing across ramp resistor 124 to be equal to the reference voltage VA. Thus, the charging current to the ramp generating capacitor 120 and the resulting ramp voltage is dependent on the voltage VB, which is equivalent to reference voltage VA. Thus, variations in the internal threshold voltage appearing across resistor 119 appear as corresponding variations in the ramp voltage. Since both the threshold voltage appearing at point 125 and the ramp voltage appearing at point 123 are applied to differential comparator 132, any variations in the voltages due to temperature changes, power supply variations or component variations appears as a common mode signal to differential comparator 132 and are rejected.
Comparator 132 develops an output when the ramp voltage at point 123 reaches the threshold voltage at point 125. At that point, a "high" signal appears on leads 134 which "high" signal indicates the programmed time delay from the occurrence of the MDO signal (or the trigger signal).
As with the circuit that generates the MDO signal, an offset current source 136 is connected to point 125. Current source 136 maintains comparator 132 in its "off" state in the absence of signals from capacitor 120 and converter 128.
FIG. 2 shows a detailed electrical schematic of the TRIGGER/RESET flip-flop and input signal comparator circuitry. As previously mentioned, the TRIGGER/RESET flip-flop is designed so that the TRIGGER input is rising-edge sensitive and the RESET input is level sensitive and dominates over the TRIGGER input. The circuitry is arranged so that either single-ended or differential inputs can be used. In the case of a single-ended input, the unused input is pulled by internal resistors to the emitter-coupled logic (ECL) midpoint voltage (VBB). For example, for single-ended operation of the SET input, resistor R148 pulls the SET* input to the midpoint voltage VBB.
Midpoint voltage VBB is established by transistor Q249. More particularly, the base of transistor Q249 is held at a potential between gorund and the negative supply (VEE) by means of a voltage divider consisting of resistor R138, diodes Q250 and Q251 and resistor R139. The emitter of transistor Q249 thus establishes the ECL midpoint voltage by means of current running through resistor R140. It should be noted that some transistors have a notation "A" next to the transistor symbol. This notation refers to the relative emitter area. Thus, a transistor with a notation of 2A has twice the emitter area of a transistor with the notation "A". An absence of a notation denotes a transistor with an area equivalent to a transistor with a notation of "A".
A "high" signal applied to the SET input triggers the device. This "high" signals is applied to the base of transistor Q409. Transistors Q409 and Q410 are connected in a well-known emitter-coupled differential circuit. In this circuit, the emitters of both transistors are tied to a current source which conducts a predetermined amount of current. More specifically, the current source consists of transistor Q424. The base of transistor Q424 is connected to a voltage source whose output is driven by transistor Q203 (shown in FIG. 4). Consequently, the emitter of transistor Q424 is fixed at a predetermined potential and a predetermined, constant current is drawn through resistor R420 to the negative supply voltage, VEE.
Returning to the emitter-coupled differential pair, Q409 and Q410, in accordance with conventional operation, when transistor Q409 turns "on", it conducts the entire current drawn by the current source. Thus, transistor Q410 is turned "off".
With transistor Q410 turned "off", resistor R407 pulls the base of transistor Q411 "high", turning "on" transistor Q411. Turned-on transistor Q411 applies a "high" signal to the base of transistor Q416, in turn, turning it "on". Transistors Q412, Q413, Q415 and Q416 are connected in a flip-flop configuration and, when transistor Q416 turns "on" it pulls the base of transistor Q413 "low", which, in turn, pulls the base of transistor Q415 "low", turning it "off".
When transistor Q415 turns "off", it allows resistor R408 to pull the base of transistor Q412 "high" and turn "on" transistor Q412, which transistor maintains transistor Q416 in an "on" state.
The base of transistor Q157 is also tied to the base of transistor Q416 so that, when the Q412-Q416 flip-flop is set, transistor Q157 is also turned "on". As will hereinafter be described, the collector of transistor Q157 is connected to the ramp generator circuitry so that ramp generation begins when transistor Q157 is turned "on".
At the time when the Q412-Q416 flip-flop is "set", both transistors Q415 and Q156 (connected in parallel to transistor Q415) are turned "off". When transistor Q156 turns "off", it allows resistor R401 to pull the base of transistor Q401 "high". This latter action sets a flip-flop consisting of transistors Q402, Q403, Q406 and Q407. When the Q402-Q407 flip-flop is "set", it turns Q408 "on" which pulls the base of transistor Q411 "low". Transistor Q411 is thus inhibited, to prevent improper re-triggering of TRIGGER input.
As previously mentioned, a RESET signal applied to the RESET input overrides the signals applied to the TRIGGER inputs. Thus, if a "high" RESET signal is applied to the RESET inputs, the converter circuit cannot be triggered and, if the converter circuit had already been triggered, the circuit is reset.
In accordance with the invention, the reset circuitry is designed to rapidly turn off transistor Q157, thus resetting the circuit. This rapid turn off is accomplished by immediately depriving transistor Q157 of collector current upon the occurrence of a RESET signal. Subsequently, the triggering flip-flops are reset to maintain the circuit in a reset condition. More particularly, a "high" signal applied to the RESET input is applied to the base of transistor Q429 turning it "on". Transistors Q428 and Q429 are connected in an emitter-coupled differential pair and, thus, transistor Q428 turns "off" when transistor Q429 turns "on". When transistor Q428 turns "off", it deprives transistor Q157 of collector current (since the current for transistors Q156 and Q157 passes through transistor Q428) and transistor Q157 immediately turns "off" resetting the ramp generation circuitry.
In addition, the "high" RESET signal is applied to the base of transistor Q419 turning it "on". Transistors Q418 and Q419 are also connected in an emitter-coupled differential pair and, thus, transistor Q418 turns "off". This latter action allows resistor R412 to pull the base of transistor Q430 "high", resetting the Q412-Q416 flip-flop and maintaining the circuit in the reset condition. When the Q412-Q416 fil-flop is reset Q408 is also turned "on", which action pulls the base of Q411 "low", in turn, inhibiting trigger pulses from retriggering the system.
The ramp generator and inventive voltage coupling circuit is shown in detail in FIG. 3. The Ramp generator circuit consists of timing capacitor C s and timing resistor R s . The voltage coupling circuit consists of transistors Q174-Q180. Ramp generation begins when the TRIGGER/RESET flip-flop is "set" as previously described. More particularly, when transistor Q157 (FIG. 2) turns "on", the base of transistor Q158 is pulled "low" turning the latter transistor "off". Transistor Q158 normally shorts timing capacitor C s . Therefore, when transistor Q158 turns "off", it allows capacitor C s to begin charging from VCC, through transistors Q164, Q168, resistor R141, Q174, Q178 and timing resistor R s to the supply voltage VEE.
Transistors Q164 and Q168 act as part of a current divider, however, transistors Q174 and Q178 act, as will hereinafter be described, to insure that the timing capacitor charging current tracks variations in the DAC current caused by thermal and supply variations and, accordingly, that the ramp voltage tracks the threshold voltage.
A capacitor, C1, is connected to the base of transistor Q158 to delay the rise of the base voltage of transistor Q158 during reset of the ramp generator when control transistor Q157 (FIG. 2) turns "off". The small delay produced by capacitor C1 is necessary to prevent transistor Q158 from going into saturation as it charges capacitor C s during reset operation. Capacitor C1 thus speeds the ramp reset cycle.
The ramp voltage developed across capacitor C s is applied to the base of transistor Q159 which acts as an emitter follower. From the emitter of transistor Q159 the ramp signal is applied through diode Q265 to point A. The signal at point A is one of the signals which is provided to the output comparator. In order to convert the ramp voltage into a time delay, the ramp voltage is compared to a threshold voltage which is generated by a DAC. The DAC threshold voltage appears at the base of transistor Q161 and is applied through transistor Q161 (which acts as emitter follower) and diodes Q160 and Q266 to point B. The signal at point B acts is compared to the signal at point A by the output comparator. Since the ramp slope, the initial ramp starting voltage and the threshold voltage are known, a predictable delay can be generated.
More particularly, the threshold voltage is generated by a current drawn through resistor R76 by the DAC. The DAC converts the value of a digital word into a predetermined current flow through resistance R76 by selectively connecting internal current sources either to resistor R76 or to the power supply. The internal DAC current sources are weighted as binary submultiples of the total DAC current which is independent of the value of the digital word. Accordingly, although the value of the threshold voltage depends on the exact combination of current sources connected to resistor R76, it will always be proportional to the total DAC current. The total DAC current flows from the DAC through the voltage coupling circuit path consisting of transistors Q175 and Q179 and the reference resistor R84 to the supply voltage VEE. Accordingly, the voltage across the reference resistor R84 is proportional to the threshold voltage.
In the illustrative embodiment shown in FIGS. 2-3, resistor values are noted next to each resistor. The values are given in ohms with the notation "K" equivalent to a multiplier of 1000. Capacitor values are given in picofarads. The transistors are of standard NPN configuration.
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A ramp voltage generator which utilizes a simple resistance/capacitance charging circuit to generate a linear ramp voltage is reset by means of a shorting transistor connected across the capacitor. The shorting transistor is, in turn, controlled by the output of a flip-flop that responds to set and reset signals applied to the circuit. In order to decrease the overall reset time of the circuit and thereby increase the operational frequency, a current switch is provided which bypasses the flip-flop and immediately diverts current to the shorting transistor upon the application of a reset signal to the circuit.
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BACKGROUND OF THE INVENTION
The invention concerns a device for sorting work piece parts cut out on a machine for cutting out work pieces in the case of processing at a processing station with at least one guiding device located at the processing station under a plane of the work piece processed with at least one guide element, by means of which the work piece parts can be guided to at least two different removal devices and in this way delivered to two different storage areas.
Such sorting devices are known to be used on sheet metal cutting machines, by means of which parts with predetermined contours are cut out of sheet metal plates. The cutting station of the machine in this case also is stationary as a guide device for the work piece parts, which as a guide element for the work piece parts has two inclined planes leading in different directions. The sheet metal plate to be processed is moved by means of a numerically controlled coordinate guide opposite the cutting station of the machine. With separation of the last connecting points between the sheet metal part and the sheet metal place, the cut-out part drops down from the cutting station under the effect of the force of gravity and thus onto one of the two inclined planes of the guiding device. Onto which of the two inclined planes the sheet metal part falls, and consequently the direction of removing the sheet metal part, is determined by the position of the sheet metal part vis a vis the guiding device at that moment when its last connection with the rest of the sheet metal plate is severed, and thus by the position of the last connection of the sheet metal part. Correspondingly, the coordinate guiding of the previously known machine is to be controlled in such a way that at the time of making the last separating cut the cut-out sheet metal part is located over the one of the two inclined planes of the guiding device by means of which the removal in can be carried out in the desired removal device. The position of the last separating cut on the work piece is predetermined correspondingly by programming the machine control and varies depending on the desired direction of removal.
The sorting of the work piece parts arriving at the cutting station of the previously known sheet metal cutting machine needs a considerable control, or, as the case may be, programming, expense.
The task of the present invention consists in simplifying the sorting of the work piece parts.
SUMMARY OF THE INVENTION
In accordance with the invention this task is solved by means of the fact that on a device of the type mentioned initially the guide element is controllable and different directions of removal of the work piece parts are associated with different control states of the guide element. The device in accordance with the invention permits a sorting of the work piece parts cut out at the processing station with the prerequisite that at the time of making the last separating cut these assume a position, staring from which they can reach the guiding device. The device for removing work piece parts to the different storage areas is determined only on the guiding device. The control of the guide element necessary for this purpose requires only a slight expense. Consequently, the cutting can be guided uniformly along the outer contour of the work piece parts and in this case without the sorting process following the work piece processing having to be taken into account by means of the guide element or elements.
A preferred embodiment of the device in accordance with the invention is distinguished by means of a simple kinematics of the guide element for determining the work piece part removal device, in the case of which the guide element can be swivelled around at least one swivel axis and is controllable in at least two swivel positions, with which different work piece part removal devices are associated.
A guide vane capable of swivelling around at least one swivel axis with a guide surface for the work piece partsโas provided in a further development of the inventionโis recommended as a structurally simple and functionally secure guide element.
In swivel positions, with which different directions of removal of the work piece parts are associated, the guide vane can be controlled in the case of a further version of the device in accordance with the invention by swivelling it around two swivel axes running parallel to each other, separated from one another parallel to the guide surface.
Structurally the swivelling capacity of the guide vane around two swivel axes in the sense of the invention is made possible by the fact that the guide vane is connected swivellable around a first swivel axis with a bearing plate supporting the guide vane on one side in the direction of swivelling, which bearing plate is mounted capable of swivelling around a second swivel axis and that in each case a controllable elevating mechanism engages the guide vane at a distance from the first swivel axis and the bearing plate at a distance from the second swivel axis, by means of which elevating mechanism the guide vane can be swivelled around the first swivel axis, or, as the case may be, the unit of the guide vane and the bearing plate can be swiveled around the second swivel axis. In the case of the swivel motion around the second swivel axis, the baring plate puts the guide vane supported on it in the direction of swiveling.
In the interest of a space-saving construction of the guiding device in the case of a preferred embodiment of the device in accordance with the invention, it is provided that the guide vane is connected capable of swiveling around a first swivel axis with a bearing plate supporting the guide vane on one side in the direction of swivelling and can be locked against swivelling with the bearing plate, and that a controllable elevating mechanism engages the guide vane at a distance from the first as well as the second swivel axis, by means of which elevating mechanism the guide vane can be swivelled around the first axis, or, as the case may be, the unit of the guide vane as well as the bearing plate locked with it can be swivelled around the second swivel axis. The capability of locking the guide vane and bearing plate opens the possibility of optionally swivelling the guide vane around one or the other swivel axis with a single elevating mechanism.
In a preferred further development of the last-named embodiment of the invention, the guide vane and the bearing plate can be locked with one another by means of a locking pin, the movement of which can be controlled on one part, and a locking pin support on the other part.
In accordance with the invention in this case the locking pin is formed by a piston rod of a piston-cylinder unit, the operation of which can be controlled.
A controllable piston-cylinder unit hinged capable of turning on the guide vane or on the bearing plate around a swivel axis parallel to the swivel axis concerned is provided as a continuously functionally reliable and easy to control elevating mechanism for the guide vane, or, as the case may be, the bearing plate.
In the case of a further design of the device in accordance with the invention, the guide vane is capable of swivelling around a swivel axis located on its edge. In addition, or alternatively, the guide vane in a further embodiment of the invention is made as a rocker capable of swiveling around a swivel axis located at a distance from vane edges lying at a distance opposite each other.
As an alternative to a swivelable guide element of the type described above, in the case of one embodiment of the device in accordance with the invention an endless conveyor belt for the work piece parts, capable of being controlled in its direction of motion, is provided as a guiding element. Such a conveyor belt makes it possible to convey the work piece parts to be sorted in different directions in the case of low design heights transverse to the plane of the conveyor belt.
A secure intermediate storage of the work piece parts cut out at the processing station before they are removed to different storage sites is provided in a further development of the invention by connecting a chute to the guiding device in order to convey the work piece parts from the processing station and by providing the guide vane or the conveyor belt in the case of an essentially horizontal orientation with an effective stop for the work piece parts in the direction of conveyance. Via the chute the work piece parts reach the guide vane or the conveyor belt, where the stop provided there holds them back, before they then are guided in the desired direction and removed by corresponding control of the guide vane or the conveyor belt.
Instead of a guide vane or a controllable conveyor belt, in the case of a further design of the device in accordance with the invention a swivel lever of a deflector-like guide device is provided as a guide element, which is capable of swiveling on a bearing surface for the work piece parts around a swivel axis running transverse to the bearing surface.
DESCRIPTION OF THE DRAWINGS
The invention is explained in greater detail below by means of schematic representations of specific embodiments. Here:
FIG. 1 illustrates a first embodiment of a device for sorting punched parts produced on the sheet metal punching machine (only partially shown) with the guide member shown in solid line in a horizontal position and in phantom line in a first tilted position;
FIG. 2 is a similar view of the device and machine with guide member shown in a second titled position;
FIG. 3 is an enlarged illustration of the sorting device of FIG. 1 also showing a second piston/cylinder assembly;
FIG. 4 is a similar illustration with the sorting device in the alternate position seen in FIG. 2;
FIG. 5 is an illustration of a second embodiment of the sorting device for sorting punched parts on a sheet metal punching machine;
FIG. 6 is an illustration of a third embodiment of the sorting device for sorting punched parts on a sheet metal punching machine with the guide member in a horizontal position.
FIG. 7 is a similar illustration of the sorting device of FIG. 6 with the guide member in a tilted position;
FIG. 8 is an illustration of a fourth embodiment of the sorting device for sorting punched parts on a sheet metal punching machine with a swiveling lever in a first position;
FIG. 9 is a similar illustration of the device of FIG. 8 with the swiveling lever in an alternate position;
FIG. 10 is an illustration of a fifth embodiment of the sorting device for sorting punched parts on a sheet metal punching machine with a movable belt device rotating in a first direction shown by the arrow; and
FIG. 11 is a similar view of the sorting device with the movable belt rotating in the opposite direction as shown by the arrow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with FIG. 1 a sorting device for sheet metal parts is located on a base frame 1 of a sheet metal punching machine. The sorting device essentially includes a feeding chute 2 , a guide device 3 with a guide element in the form of a guiding vane 4 , as well as removing chutes 5 , 6 .
The feeding chute 2 extends inclined downward from a punch die 7 of a processing station designed as a punch station 8 . The punch die 7 supports the sheet metal to be processed at the time of its processing and defines the sheet metal plane together with a work piece table. The guide device 3 is connected on the side of the feeding chute 2 lying at a distance from the punch die 7 with the guide vane 4 on the feeding chute 2 . In the initial position shown in FIG. 1 with extended lines, the guide vane 4 is oriented horizontally. Opposite the feeding chute 2 it has a stop 9 for the sheet metal parts fed to it. Extending from the guide vane 4 the removing chutes 5 , 6 extend in directions opposite one another and open into collecting and transporting boxes 10 , 11 ,
At the punching station 8 , numerically controlled sheet metal parts with different contours are punched out a sheet metal plate. Uniformly contoured sheet metal parts are to be delivered to one and the same collecting and transporting boxes for discharging from the sheet metal stamping machine. For this purpose the sheet metal to be processed by punching is positioned by means of a numerically controlled coordinate guide opposite the punch station 8 in such a way that the sheet metal part concerned is located over the feeding chute at the time of separating its last connection with the rest of the sheet metal. After making the last separating cut, the sheet metal part concerned consequently falls onto the feeding chute 2 , via which it reaches the horizontally oriented guide 4 of the guide device 3 under the action of the force of gravity, and is temporarily stored there. In this case the stop 9 prevents the sheet metal part from sliding out in the direction of removal over the guide vane 4 . For example, depending of the dimensions of the sheet metal parts produced, the guide vane 4 is operated for each sheet metal part temporarily stored on the guide vane 4 or for several sheet metal parts. In this case the guide vane 4 can be swivelled into the position shown in FIG. 1 with interrupted lines or in the position shown in FIG. 2 . In the case of the position raised on one side in accordance with FIG. 1, the sheet metal part or parts temporarily stored on the guide vane 4 are conveyed via the removing chute 5 into the collecting and transporting box 10 . Correspondingly sheet metal parts temporarily stored on the guide vane 4 are fed to the collecting and transporting box 11 via the removing chute 6 in the case of the position of the guide vane 4 in accordance with FIG. 2 .
The design features for realizing the described kinematics of the guide vane 4 are shown in FIGS. 3 and 4. Therefore the guide vane 4 is connected with a bearing plate 13 supporting the guide vane 4 on one side in the direction of swivelling, capable of swivelling around a first swivel axis 12 . The bearing plate 13 again around a second swivel axis 14 , is connected with a base plate 15 , which for its part is mounted on the base frame 1 of the sheet metal punching machine. At a distance from the first swivel axis 12 as well as from the second swivel axis 14 parallel to the plane of the bearing surface for the sheet metal parts on the guide vane 4 as well as in the transverse direction of the swivel axes 12 , 14 , an elevating mechanism in the form of a controllable pneumatic piston-cylinder unit 16 engages the guide vane 4 . A piston-cylinder rod 17 in this case is hinged to the stop 9 of the guide vane 4 via a swivel pin 18 . A swivel connection between the cylinder 19 of the piston-cylinder unit 16 with the base frame 1 of the sheet metal punching machine is made via a swivel pin 20 .
A further controllable pneumatic piston-cylinder unit 21 is mounted on the bearing plate 13 . It includes a cylinder 22 connected permanently with the bearing plate 13 as well as a piston rod 23 guided capable of moving therein in the horizontal direction in accordance with FIG. 3 and serves for mutual locking of the guide vane 4 as well as the bearing plate 13 . For this purpose a hole is associated with the free end of the piston rod 23 used as a locking pin as a locking pin support on the guide vane 4 . The fastening screws 24 , 25 hold the bearing of the swivel pin 20 .
FIG. 3 shows the guide vane 4 in the raised position in accordance with FIG. 1, in which the sheet metal parts are guided to the collecting and transporting box 10 . If the sheet metal parts prepared at the punching station 8 are to be conveyed to the collecting and transporting box 11 โfor example because the collecting and transporting box 10 is filled or because sheet metal parts with a changed contour are being producedโthe guide vane 4 is to be swivelled out of its raised position in accordance with FIGS. 1 and 3 next with operation of the piston-cylinder unit 16 into its horizontal initial position, in which it can be temporarily store the sheet metal parts concerned. Then the guide vane 4 can be locked by driving the piston rod 23 of the piston-cylinder unit 23 on the bearing plate 13 . By operating the piston-cylinder unit 16 the unit of guide vane 4 and bearing plate 13 now is swivelled into the position in accordance with FIGS. 2 and 4. The sheet metal parts previously fed to the guide vane 4 via the feeding chute 2 and temporarily stored on the guide vane 4 then can enter the collecting and transporting box 11 via the removing chute 6 . So that in the case of swiveling of the guide vane 4 into the raised position in accordance with FIGS. 1 and 3, and unintentional swiveling of the bearing plate 13 around the second swivel axis 14 is excluded, the bearing plate 13 can be locked on the base frame 1 of the machine before raising the guide vane 4 out of its horizontal initial position, for example by means of the piston-cylinder unit 21 .
A locking of this kind can be achieved in the case of sufficient tightness of the swivel connection between the bearing plate 13 and the base plate 15 produced via the second swivel axis.
In the case of the sorting device in accordance with FIG. 5, instead of the guide device 3 with the guide vane 4 in accordance with FIGS. 1 to 4 , a guide device 103 with a guide element in the form of a guide vane 104 is used, which, beginning from its horizontal initial position, in which the prepared punched parts are fed to it. can be swivelled around a swivel axis 126 . The guide vane 104 makes it possible to discharge the sheet metal parts to be sorted on one and the same side of the sheet metal punching machine from the latter. The different removal devices in this case differ in their inclination with respect to the horizontal.
In accordance with FIGS. 6 and 7 a guide device 203 with a rocker-like guide vane 204 is used as a guide element which can be swivelled around a swivel axis 226 located at a distance from edges of the guide vane 204 lying opposite on another.
A guide device 303 , as is shown in FIGS. 8 and 9, is made as a deflector and has as a guiding element a swivel lever 327 , which is mounted capable of swiveling around a swivel axis 326 running transverse to the bearing surface 302 on a feeding chute serving as a bearing surface 302 for the sheet metal parts. Depending on its swivel position, the swivel lever 327 guides the sheet metal parts fed to it under the influence of the force of gravity into one or the other directions of conveyance. Unlike the other guide arrangements proposed as examples, the guide arrangement 303 offers no intermediate storage for the sheet metal parts to be discharged.
In accordance with FIGS. 10 and 11, the guide arrangement 403 is a horizontal conveyor with a guide element made as an endless conveyor belt 428 , capable of being controlled in this direction of motion, to which the sheet metal parts are fed via a feeding chute 402 and from which the sheet metal parts temporarily stored on it optionally are transferred to a removing chute 405 or a removing chute 406 .
The control conditions of the guide elements described aboveโtherefore the swivel positions of the guide vanes 4 , 104 , 204 , the swivel position of the swivel lever 327 , as well as the direction of motion of the endless conveyor belt 428 โare adjusted automatically by means of the numerical control of the sheet metal punching machine.
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A machine tool/parts sorter assembly includes a machine tool having a frame and a workstation at which multiple parts are cut from a workpiece as it is moved in a horizontal plane relative to the workstation. A sorter is coupled with the machine tool frame for separately guiding different parts to different discharge areas adjacent the machine tool. The sorter includes a guide member adjacent the workstation for receiving the parts from the workstation, a pair of spaced, downwardly inclined guide chutes for discharging parts to separate discharge areas, and an actuator for selectively moving the guide member to discharge parts thereon into the guide chutes.
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TECHNICAL FIELD
This invention relates to the protection of privacy of computer users.
BACKGROUND
Computers, such as personal computers, are subject to a variety of attacks from individuals over networks such as the Internet or Intranet. The implanting of viruses in personal computers causing the personal computer to either fail or send large amounts of email is a common type of attack. Another type of attack that is becoming increasingly prevalent is that of using a personal computer to eavesdrop on the owner of that personal computer either via audio or video information. This information is transmitted from the user's personal computer to the individual who is performing the eavesdropping. This is done by inserting a routine into the personal computer that captures audio information from a microphone attached to the computer and/or video information from a camera attached to the personal computer. In certain types of personal computer applications such as IP telephony or Net Meeting Services, the individual wishing to eavesdrop on a user's computer simply initiates one of these services and directs the information to the individual's computer. Also, the individual may simply use a legitimate application programming interface (API) to eavesdrop with the chosen API directing audio and/or video to a bugging application that had been inserted into the user's computer. Examples of such API may be but is not limited to Microsoft IP Telephone Programming Interface or Avaya IP Softphone Telephone Programming Interface.
Another way to eavesdrop utilizing a user's personal computer is to insert a routine into the personal computer that monitors the audio and/or video inputs and transmits these to an individual's computer. This type of eavesdropping is extremely difficult to detect whereas it is reasonably easily implemented.
Existing prior art solutions to preventing damage or illegal use of personal computers is done using virus scanners and firewalls. Whereas both of these techniques provide some protection against eavesdropping, they are not a fail safe mechanism.
SUMMARY
A method and apparatus prevent eavesdropping via a computer by detecting a use of at least one of audio or visual input information by a software entity; determining if the software entity is authorized to receive the input information and; alerting upon the software entity being unauthorized.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates an embodiment having two computer systems interconnected via a wide area network (WAN);
FIG. 2 illustrates an embodiment detailing the processes and routines relative to the detection and bugging of a user's computer; and
FIGS. 3 and 4 illustrates, in flow chart form, operation performed by an embodiment.
DETAILED DESCRIPTION
FIG. 1 illustrates, in block diagram form, an embodiment that illustrates user computer system 100 interconnected to intruder computer system 120 via wide area network (WAN) 117 . WAN 117 may be a local area network (LAN), Internet, Intranet, or any other type of network utilized for interconnecting computer systems. In the following examples, user computer system 100 is utilized by the individual controlling intruder computer system 120 to eavesdrop on the activities of the user of user computer system 100 . User computer system 100 and intruder computer system 120 may be identical or similar or have different components. User computer system 100 must provide the necessary input devices so that audio or video information can be recorded so that it can be transmitted to intruder computer system 120 via WAN 117 .
In one embodiment, intruder computer system 120 opens a valid application such as an IP telephony or Net Meeting application to perform the eavesdropping. By opening one of these applications, information from microphone 114 or video camera 113 is transmitted to intruder computer system 120 via WAN 117 .
In another embodiment, intruder computer system 120 puts a hidden routine into memory 101 of user computer system 100 . This hidden routine then enables the utilization of microphone 114 or video camera 113 so that information concerning the user of computer system 100 can be captured. This captured information is then transmitted to intruder computer system 120 via WAN 117 . The captured information may be transmitted as received or stored for later transmission in memory 101 that may comprise RAM memory, hard drive storage, etc. This hidden routing may receive the information from a legitimate API or may insert a driver into computer system 100 to receive the information directly from interface circuit 107 or 106 connected to microphone 114 or video camera 113 , respectively.
Computer 102 functions by executing and storing data out of memory 101 . The user of user computer system 100 utilizes devices 111 - 116 that are interfaced to computer 100 via interfaces 103 - 108 , respectively, to provide and receive information from computer 102 . WAN interface 109 interfaces computer 102 to WAN 117 . One skilled in the art could readily envision that there could be a plurality of interface circuits such as interface circuits 126 and 127 . Intruder computer system 120 is illustrated as having similar components. Components 123 - 136 correspond in operations to components 103 - 116 . WAN interface 129 performs similar functions to those performed by WAN interface 109 .
In one embodiment, intruder computer system 120 under control of the program being executed in memory 121 by computer 122 utilizes an IP telephony or Net Meeting application to activate microphone 114 and/or video camera 113 in user computer system 100 . The information received from input devices 114 or 113 is then relayed to intruder computer system 120 by the opened application in user computer system 100 . The information received from user computer system 100 then can be displayed by intruder computer system 120 on display 132 if it is video information or played on speaker 136 if it is audio information.
In the other embodiment, intruder computer system 120 utilizes a variety of methods well known to those skilled in the art to insert a routine into memory 101 of user computer system 100 . This routine, referred to as a bug routine, then activates video camera 113 or microphone 114 via a legitimate API or an inserted driver to receive information from these input devices via their interface circuits. The bug routine may immediately transmit this information to intruder computer system 120 via WAN 117 or may store it in memory 101 for later transmission to intruder computer system 120 .
FIG. 2 illustrates the software components that would be present in a Windowsโข operating system environment and other operating system environments for performing bugging operations and also to perform the bugged detection operations. Authorized drivers 204 - 206 are the authorized drivers that exist on user computer system 100 to control and receive digital audio information legitimately from interface circuit 107 . Note, that interface circuit 107 maybe physically in computer system 100 or part of microphone 114 and interconnect to computer system 100 via an external communication channel such as but not limited to a Universal Serial Bus (USB).
Authorized drivers 204 - 206 may be established by API's 209 - 211 . API's 209 - 211 may be used legitimately by an IP telephony, Net Meeting applications, etc. or illegitimately by an unauthorized routine or application such as bug routine 208 . Bugging driver 207 is a driver set up by bug routine 208 to control and receive digital audio information from microphone 114 . Bugging driver 207 is inserted into memory 101 of user computer system 100 so that bug routine 208 can fraudulently receive audio digital information. Bug routine 208 may also use API's 209 - 211 to receive fraudulently audio digital information. Storage 212 may be any type of storage known to one skilled in the art and may be used by to bug routine 208 to store audio digital information for later transmission via WAN interface 109 .
Bug detection routine 203 periodically uses driver 202 to interrogate interface circuit 107 to determine when one of drivers 204 - 206 is actively controlling and receiving digital audio information from interface circuit 107 using techniques well known to those skilled in the art. In the first embodiment where a authorized driver or API is being utilized to fraudulently obtain digital audio information, when bug detection routine 203 determines that such a driver is active and is receiving digital audio output from interface circuit 107 , bug detection routine 203 first must determine if the driver is an authorized driver whose activities are being requested by an authorized API. If this is true, bug detection routine 203 determines if more than one authorized application is using the authorized API. If there is more than one authorized application, bug detection routine 203 alerts the user. If there is only one authorized application receiving digital audio information, bug detection routine 203 will still alert the user when this application first starts to receive digital audio information.
If an unauthorized application is using an authorized API, bug detection routine 203 alerts the user and allows the user to terminate the unauthorized application. Bug detection routine 203 also alerts the user if there are more than one authorized driver or API accessing interface circuit 107 .
In the other embodiment, intruder computer system 120 inserts bugging driver 207 and bug routine 208 into memory 101 of user computer system 100 . Bugging driver 207 and bug routine 208 are unauthorized and not registered on user computer system 100 . Bug routine 208 initiates bugging driver 207 . Bug detection routine 203 again periodically uses driver 202 to interrogate interface circuit 107 to determine when an unauthorized driver is actively controlling and receiving digital audio information from interface circuit 107 . When such an unauthorized driver is detected, bug detection routine 203 attempts to identify the unauthorized driver and gives the user the opportunity to terminate the unauthorized driver and any application or routine using it. Both embodiments would be implemented together.
When bugging process 207 transfers digital audio information to bug routine 208 , bug routine 208 may immediately transmit the digital audio information via WAN interface 109 to intruder computer system 120 . Also, bug routine 208 may store the digital audio information in memory 101 until an opportune time occurs for the transmission of the digital audio information to intruder computer system 120 . In addition, bug routine 208 may compress the digital audio information before transmission to intruder computer system 120 .
The detection of video eavesdropping could be performed in a manner similar to that illustrated in FIG. 2 and described with respect to FIG. 2 . With the exception that video camera 113 and interface 106 would be utilized rather than microphone 114 and interface 107 .
In one embodiment, bug detection routine 203 is a stand alone routine that performs its operation without utilizing other applications. In another embodiment, bug detection routine could be part of a registered application that uses audio information such as an IP telephony application. This could allow the IP telephony application to assure that eavesdropping was not taking place. In yet another embodiment, bug detection routine 203 could be part of a standard virus detection program. As part of a standard virus detection program, bug detection routine 203 would perform its operations as noted above but upon determining an illegal bug routine, such as bug routine 208 , it would utilize the resources of the virus application to remove the bug routine and the bugging process from user computer system 100 .
Although FIG. 2 is described in terms of the Windowsโข software, one skilled in the art could readily envision how these operations would be performed in other operating system environments such as Linuxโข, Unixโข, etc.
FIGS. 3 and 4 illustrate, in flowchart form, the operations performed by bug detection routine 203 of FIG. 2 . After being started in block 301 , decision block 302 determines if any input audio from a microphone such as microphone 114 is being utilized within the user computer system. If the answer is no, control is returned to decision block 302 . If the answer is yes in decision block 302 , decision block 303 determines if more than one driver such as drivers 204 - 207 of FIG. 2 are active. If the answer is no, block 304 sets the variable โnumber driversโ equal to one and transfers control to decision block 308 . If the answer in decision block 303 is yes, block 306 alerts the user of the user computer system to the fact that more than one driver is actively receiving audio and transfers control to block 307 . Block 307 sets the โnumber driversโ variable equal to the active number of drivers that was determined in decision block 303 before transferring control to decision block 308 .
Decision block 308 determines if the driver identified by the โnumber driversโ variable is an authorized driver to be operating on the user computer system. If the answer is no, control is transferred to block 413 of FIG. 4 .
If the answer is yes in decision block 308 , decision block 309 determines if more than one authorized API is using the driver identified in decision block 308 . If the answer is yes, block 311 identifies the APIs that are active, and block 312 alerts the user to the fact that there are more than one API actively using the driver and also supplies the identification information of these APIs to the user before transferring control to block 317 .
If the answer is no in decision block 308 , decision block 313 determines if more than one authorized application is using the API that is using the identified driver. The API in question was identified in decision block 309 . If the answer in decision block 313 is yes, block 314 determines the identity of all the applications that are actively using the API, and block 316 alerts the user and identifies the applications utilizing the information obtained in block 314 before transferring control to block 317 . If the answer in decision block 313 is yes, control is transferred to decision block 401 of FIG. 4 .
If control is transferred from blocks 312 , 316 or connector C from FIG. 4 , block 317 sets the โnumber driversโ variable equal to the โnumber driversโ variable minus one before transferring control to decision block 318 . Decision block 318 determines if the โnumber driversโ variable is equal to zero. If the answer is yes, control is transferred back to decision block 302 . If the answer in decision block 318 is no, control is transferred to decision block 308 so that the next active driver can be evaluated.
Returning to decision block 308 , if the answer is no that the driver presently being evaluated is not an authorized driver, control is transferred to block 414 . Block 414 alerts the user to the presence of an unauthorized driver before transferring control to decision block 416 . Decision block 416 then allows the user to make the determination of whether or not to delete the driver from the user's computer system. If the answer is no, control is returned back to block 317 . If the answer is yes in decision block 416 , block 417 deletes or removes the driver from the user's computer system before transferring control back to block 317 .
Returning to decision block 313 of FIG. 3 , if the answer is no in decision block 313 , control is transferred to decision block 401 of FIG. 4 . Decision block 401 determines if an unauthorized application is using an authorized API that is using the driver previously identified in decision block 308 . If the answer in decision block 401 is yes, block 402 alerts the user to this fact before transferring control to decision block 403 . Decision block 403 gives the user the ability to terminate the application and in one embodiment to remove the application from the user's computer system. If the answer in decision block 403 is yes, block 404 terminates the application or removes the application from the computer system before transferring control back to block 317 of FIG. 3 . If the answer in decision block 403 is no, control is transferred back to block 317 .
Returning to decision block 401 , if the answer in decision block 401 is no, decision block 406 determines if an unauthorized routine is using an authorized driver that was identified in decision block 308 . If the answer is no, control is transferred to decision block 411 .
If the answer in decision block 406 is yes, block 407 alerts the user before transferring control to decision block 408 . Decision block 408 allows the user to determine whether or not to delete or remove the routine from the user's computer system. If the answer in decision block 408 is no, control is transferred back to block 317 . If the answer in decision block 408 is yes, block 409 deletes or removes the routine from the user's computer system before transferring control to block 317 of FIG. 3 .
Returning now to decision block 406 , if the answer in decision block 406 is no control is transferred to decision block 411 . Decision block 411 determines if this is the first use of the driver, which has been previously determined to be an authorized driver, by an authorized API and an authorized application. If the answer is yes, block 412 alerts the user before transferring control back to block 317 of FIG. 3 . If the answer in decision block 411 is no, control is transferred back to block 317 of FIG. 3 .
When the operations of personal computers, servers, or systems are implemented in software, it should be noted that the software can be stored on any computer-readable storage medium for use by or in connection with any computer related system or method. In the context of this document, a computer-readable storage medium is an electronic, magnetic, optical, or other physical device or means that can contain or store a computer program for use by or in connection with a computer related system or method. The personal computers, servers, or systems can be embodied in any computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a โcomputer-readable storage mediumโ can be any means that can store the program for use by or in connection with the instruction execution system, apparatus, or device. For example, the computer-readable storage medium can be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM) (electronic), a read-only memory (ROM) (electronic), an erasable programmable read-only memory (EPROM, EEPROM, or Flash memory) (electronic), and a portable compact disc read-only memory (CDROM) (optical).
In an alternative embodiment, where the stations, servers, or systems is implemented in hardware, the stations, servers, or systems can be implemented with any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.
Of course, various changes and modifications to the illustrated embodiments described above would be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the following claims except in so far as limited by the prior art.
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A method and apparatus prevent eavesdropping via a computer by detecting and alerting if more than one authorized driver is controlling a interface circuit that is providing audio or video input information. Further, prevention is performed by detecting and alerting if more than one authorized application programming interface is receiving audio or video input information from an authorized driver. Also, prevention is performed by detecting and alerting if more than one authorized software application is receiving audio or video input information from an authorized driver. In addition, prevention is performed by detecting and alerting upon first receipt of audio or visual information by an authorized software application via an authorized application programming interface and authorized driver.
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This application is the national phase of international application PCT/FR97/07201 filed Jun. 3, 1998 which designated the U.S.
BACKGROUND OF THE INVENTION
The present invention relates to the field of household electric appliances in general and it is applied more particularly (but not exclusively) to pressing irons.
It concerns more precisely a thermostat control device, particularly a pressing iron thermostat, and permits, for a given path of the control means, to obtain a more precise temperature regulation and above all in the zone of the most desired temperatures.
The device according to the invention is more particularly intended to assure a precise temperature regulation function. As such, the thermostat control device according to the invention concerns more specifically, but not exclusively, pressing appliances, such as pressing irons for example.
Temperature control of pressing irons is performed by a bimetal thermostat whose operation is effected directly by a rotary button or indirectly by a device of the rack and pinion type and a linear slider. In the two cases, the temperature selection range comprises one part for heating and another intended for adjustment for the different types of fabrics utilized.
The rack and pinion system permits one to have a reduction between the slider and the thermostat to increase the precision of the adjustment. A pressing iron must have a temperature selection range going from the maximum (220ยฐ) to the shutting off of power at ambient temperature. In the context of a pressing iron using a device of the rack and pinion type to assure control of the thermostat, the path corresponding to the temperature selection phase constitutes only around one-half of the control range of said thermostat. The rest of the path of the control means corresponds to the heating phase, that is from the switching off of current to the first operating temperature of the iron.
The drawback of such a device is that around one-half of the path of the control means is not usable for selecting temperatures to be used during ironing. There thus remains less space usable to effectuate a precise adjustment in the range of operating temperatures of the iron.
BRIEF SUMMARY OF THE INVENTION
The invention has precisely for its goal to overcome this drawback, and proposes a control device for a thermostat, notably a thermostat of a pressing iron, which permits, for a given path of the control means, to obtain a more precise temperature adjustment and a longer path in the range of the most desired temperatures.
In order to attain this goal there is provided a control device for a thermostat, notably a thermostat of a pressing iron, comprising a support, an opening in said support to receive a mobile control means, a first rack forming means cooperating with said control means, guide means for said rack forming means, a pinion cooperating with the first rack forming means, characterized in that it comprises a second rack forming means disposed in the extension of said first rack forming means and that said pinion comprises two toothed zones whose respective root circle radii are different, the first toothed zone cooperating with the first rack forming means and the second toothed zone cooperating with the second rack forming means, said pinion being capable of rotating the shaft of said thermostat.
The thermostat control device according to the invention permits, for the same path of the mobile control means, to have a long adjustment path to the detriment of the approach path which becomes very small. This permits a precise adjustment for a larger range of adjustment temperatures. In addition, it is no longer necessary to displace the slider over a large range before arriving at the first operating temperature.
Another advantage connected with the utilization of a thermostat control device according to the invention is a better selection of a precise temperature corresponding to a given type of fabric.
Moreover, given the fact that the temperature adjustment range is larger, selection can be made for a larger number of temperatures and one thus obtains a large number of possibilities for corresponding fabrics to be chosen. This permits the pressing iron to cover a greater diversity of fabric types.
According to an advantageous variant of the invention, the constituent parts of the thermostat control device are fixed to the support which is secured on the frame of the pressing iron. This permits having a universal support which can be adapted to several types of pressing irons that already exist. The construction described permits use of the part comprising adjustment elements, for example the existing plate, without supplemental modifications. Moreover, there is obtained a control device assembly which is compact and which occupies very little space in the frame of the iron. Mention can also be made of the fact that such a variant implies substantial construction and assembly facilities and, consequently, a reduction in the costs of fabrication.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Other characteristics and advantages of the invention will appear more clearly in light of the description and the drawings which follow, illustrating, by way of non-limiting examples, embodiments of the invention. Thus, reference is made to FIGS. 1 to 5, where:
FIG. 1 represents an elevational cross-sectional view of a pressing iron comprising a thermostat control device according to the invention;
FIG. 2 represents a bottom view of the thermostat control device according to the invention;
FIGS. 3a and 3b represent top and side views of the plate of a pressing iron comprising a thermostat control device according to the invention;
FIG. 4 represents a schematic cross-sectional view of a thermostat control device according to the another embodiment of the invention;
FIG. 5 represents a top view of the device according to the invention showing an example of a scale for indicating the type of fabric corresponding to a given temperature.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a pressing iron 1 comprising, in a manner known per se, a sole plate 2 heated by means of a heating body 3, a steam chamber situated above the sole plate, a device for supplying water to the steam chamber and a means for adjusting said device. The iron also comprises a thermostat 7, for example of the bimetal type, to adjust the heating temperature of sole plate 2, and electric connections connecting the power mains to the body for heating the sole plate. The various adjustment elements are advantageously provided on a plate 6 disposed above the steam chamber. These different elements are disposed in a frame, or shell, 9 forming in its upper part a holding means 4 facilitating handling of the iron.
The iron according to the invention comprises a thermostat control device 10 permitting thermostat 7 to be acted on in an optimal manner. A shaft 8 of the thermostat, disposed between this latter and said thermostat control device, provides a mechanical connection between these elements.
The different elements of the thermostat control device are better seen in FIG. 2. This figure illustrates a preferred example of an embodiment of the thermostat control device according to the invention.
A support 11 presents two apertures 12 permitting connection between a mobile control means 13 disposed at the external side of support 11 and a rack assembly disposed at the internal side of said support. Said rack assembly is provided to engage a pinion 16 which acts on shaft 8 of thermostat 7. This rack assembly comprises a first rack means 14 and a second rack means 15 in the extension of the first. Pinion 16 comprises a first toothed zone 17 on a first sector of its circumference. It also comprises a second toothed zone 18 on a second sector of the circumference juxtaposed to the first.
The radius R1 of the root circle of first toothed zone 17 is less than the radius R2 of the root circle of second toothed zone 18. First rack means 14 is provided to cooperate with first toothed zone 17 and second rack means 15 is provided to cooperate with second toothed zone 18 of pinion 16.
In a rack and pinion system the ratio between the movement of the rack and the angle of rotation of the pinion is governed by the equation A=C*180/(ฯ*R) where A is the angle of rotation of the pinion, C is the travel of the rack and R is the radius of the root circle. One thus observes that the angle of rotation of the pinion is inversely proportional to the radius of the root circle. On this idea is based the operation of the thermostat control device according to the invention. In the context of adjustment of a thermostat for a pressing iron one distinguishes two temperature ranges: a heating range corresponding what is called an approach path of the control means and a second range, called of selection of temperature to be utilized during pressing. By adding the two paths corresponding to the two ranges mentioned, one obtains the total path of the control means. The thermostat control device according to the invention proposes to reduce the approach path for the purpose of utilizing with greater efficiency the remainder of the path of the control means corresponding to the zone of temperature selection or adjustment. For this purpose, in the approach phase, first rack forming means 14 rotates first toothed zone 17 of the pinion. The radius of root circle R1 is small thus the rotation, in accordance with the preceding equation, is substantial. One thus obtains a short approach path for the start up and initial heating of the iron (short path for a substantial temperature variation).
In the adjustment phase, second rack forming means 15 in turn drives second toothed zone 18 of the pinion in rotation. The radius of root circle R2 is substantial thus the angle of rotation of the pinion is small. One obtains this time a long path and a large range for selection of the temperatures to utilize in the course of pressing (long path for a limited increase in temperature).
Pinion 16 is mounted on shaft 8 of thermostat 7 and thus the rotational movement of said pinion drives in rotation the shaft of said thermostat which acts in its turn on the bimetal to modify the temperature for opening the contacts between the heating element and the current supply source. In the embodiment shown in FIG. 2, it is observed that the rack and pinion assembly is guided in its displacement with respect to the support 11 by a guide means 19. Said guide means is fixed to support 11 and it is in the form of a rail to permit the sliding of the means forming the rack and pinion assembly.
In a first advantageous modified embodiment of the invention, support 11 and the elements connected thereto are made of molded plastic to facilitate fabrication, reduce weight and equally reduce fabrication costs.
In FIG. 2, it is observed that mobile control means 13 comprises a support means on apertures 12. This support means also serves as a means for mechanical connection between mobile control means 13 and the rack and pinion assembly.
According to an advantageous variant of the invention, support 11 and the elements connected thereto are of molded plastic material to facilitate industrialization, reduce the weight and reduce, also, the fabrication costs.
The rack and pinion assembly can present, in a manner know per se, on the face opposed to that of the engagement with the pinion and along its entire length, a notched portion. This notched portion cooperates with an elastic tongue fixed to support 11. Such an arrangement confers on mobile control means 13 a pawl positioning effect having as its result a more precise positioning along the entire length of the path of said control means.
Said control means comprises graduations corresponding to the different types of fabrics utilized. It is seen moreover in FIG. 5 that the path of mobile control means 13 is virtually divided into two temperature zones: zone 1 corresponding to the approach zone and zone 2 to the adjustment zone, the first being much more reduced than the second.
In the example represented in FIG. 2, the different elements of the thermostat control device according to the invention are part of support 11.
Conforming to an advantageous variant of the invention, the different elements of said control device are fixed to plate 6 of pressing iron 1. Said plate is situated above the steam chamber of the iron and substantially parallel to the sole plate. It forms, a manner to per se, a support for the components for supplying water to the steam chamber, for the temperature adjustment means and for the electrical connections of said iron. Such a plate can be produced separately and equipped with all of the control organs on a common support, which then facilitates the assembly in the iron. Its placement in a position substantially parallel to the sole plate permits displacement in a horizontal direction of the rack forming means without increasing the space occupied. The plate is made of an insulating plastic material and it comprises on the face opposite to the sole plate conductive metalized lines whose extremities are intended to be connected to the power cord of the iron. FIGS. 3a and 3b illustrate this embodiment.
According to the another advantageous theory of the invention and which is illustrated in FIG. 4, the two toothed zones of racks 14 and 15 are found in two different parallel planes. In this case, pinion 16 has two toothed sectors or two toothed wheels 17 and 18 situated also in two different parallel planes to cooperate with the two above-cited toothed zones of racks 14 and 15.
POSSIBILITIES OF INDUSTRIAL APPLICATION
The invention finds its application in the technical field of household electric appliances.
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A thermostat control device (10), in particular an electric iron thermostat (7), comprising a support (11), an aperture (12) in said support for receiving a mobile control device (13) a first device forming a rack (14) co-operating with said control device, a guide device (19) for said rack and a gear wheel (16) cooperating with the first rack. The invention is characterized in that a second rack (150) is used provided in the extension of said first rack a gear wheel (16) comprising two toothed zones with respectively different primary circle radii, the first toothed zone (17) cooperating with the first rack (14) and the second toothed zone (18) cooperating with the second rack (16), said gear wheel being capable of driving in rotation said thermostat (7) rod (8).
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RELATED APPLICATIONS
[0001] This is a divisional of U.S. patent application Ser. No. 09/510,565, filed on Feb. 22, 2000, which is a divisional of U.S. patent application Ser. No. 08/813,151, filed on Mar. 7, 1997, now U.S. Pat. No. 6,041,345, which claims priority from Provisional Application Serial No. 60/013,029, filed on Mar. 8, 1996, and which claims priority from Provisional Application Serial No. 60/028,789, filed on Oct. 21, 1996, all of which are incorporated herein in their entireties by reference.
TECHNICAL FIELD
[0002] The present invention relates generally to data processing systems and more particularly to an active stream format for holding multiple media streams.
BACKGROUND OF THE INVENTION
[0003] Conventional file and/or stream formats for transmitting multiple data streams of varying media are limited in several respects. First, these formats are generally limited in the packet sizes that are available for encapsulating data. Such formats, if they specify packets, specify the packets as a given fixed size. Another limitation of such formats is that they do not facilitate the use of error correction codes. A further weakness of these conventional formats is that they do not provide flexibility in timing models for rendering the data encapsulated within the format. An additional limitation with such formats is that they are not well adapted for different transport mediums that have different levels of reliability and different transmission capabilities.
SUMMARY OF THE INVENTION
[0004] In accordance with a first aspect of the present invention, a computer system has a logical structure for encapsulating multiple streams of data that are partitioned into packets for holding samples of data from the multiple data streams. A method of incorporating error correction into the logical structure is performed on the computer system. In accordance with this method, a portion of at least one packet is designated for holding error correcting data. The error correcting data is then stored in the designated portion of the packet.
[0005] In accordance with another aspect of the present invention, multiple streams of data are stored in packets and error correcting data is stored in at least some of the packets. The packets are encapsulated into a larger stream and information regarding what error correcting methods are employed for the packets is also stored in the packets.
[0006] In accordance with yet another aspect of the present invention, samples of data from multiple data streams are stored in packets, and replicas of information are stored in at least some of the packets. A flag is set in each of the packets that holds replicas to indicate that the packets hold the replicas. The packets are encapsulated into a larger logical structure and transmitted to a destination.
[0007] In accordance with a further aspect of the present invention, a logical structure is provided for encapsulating multiple streams of data where the streams of data are stored in packets. Clock licenses that dictate advancement of a clock are stored in multiple ones of the packets. The logical structure is transmitted from a source computer to a destination computer. The clock is advanced at the destination computer as dictated by the clock license for each packet that holds a clock license in response to the receipt or processing of the packet at the destination computer.
[0008] In accordance with an additional aspect of the present invention, a stream format is provided for encapsulating multiple streams of data. The stream format includes a field for specifying a packet size for holding samples of the multiple streams of data. In a logical structure that adopts the stream format, a value is stored in the field that corresponds to the desired packet size. Packets of the desired size are stored within the logical structure and the logical structure is transmitted over a transport medium to the destination.
[0009] In accordance with a further aspect of the present invention, a stream format is provided for encapsulating multiple streams of data. A field is included in a logical structure that adopts the stream format for holding a value that specifies a maximum bit rate at which the multiple streams may be rendered at the destination. A value is stored in the field and the logical structure is transmitted over a transport medium to a destination.
[0010] In accordance with another aspect of the present invention, a stream format is provided for encapsulating multiple data streams and a new media type is dynamically defined. An identifier of the media type is stored in a logical structure that adopts the stream format and packets of the new media type are stored in the logical structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a block diagram illustrating a computer system that is suitable for practicing the preferred embodiment of the present invention.
[0012] [0012]FIG. 2 is a flowchart illustrating use of the ASF stream in accordance with a preferred embodiment of the present invention.
[0013] [0013]FIG. 3 is a block diagram illustrating the components of the ASF stream.
[0014] [0014]FIG. 4 is a block diagram illustrating the format of the header_object.
[0015] [0015]FIG. 5 is a block diagram illustrating the format of the properties_object.
[0016] [0016]FIG. 6A is a flowchart illustrating the steps that are performed to fill in packet size fields within the ASF stream.
[0017] [0017]FIG. 6B is a diagram illustrating different packet sizes and respective ASF streams.
[0018] [0018]FIG. 7 is a block diagram illustrating the format of the stream_properties_object.
[0019] [0019]FIG. 8 is a diagram that illustrates the partitioning of a sample for storage in multiple packets.
[0020] [0020]FIG. 9 is a diagram that illustrates the format of the content_description_object.
[0021] [0021]FIG. 10A is a diagram illustrating the format of the marker_object.
[0022] [0022]FIG. 10B is a diagram illustrating the format of a marker entry.
[0023] [0023]FIG. 11 is a diagram illustrating the format of the error_correction_object.
[0024] [0024]FIG. 12 is flowchart illustrating the steps that are performed to utilize error correcting information in accordance with a preferred embodiment of the present invention.
[0025] [0025]FIG. 13 is a diagram illustrating format of the clock_object.
[0026] [0026]FIG. 14A is a diagram illustrating the format of the script_command_object.
[0027] [0027]FIG. 14B is a diagram illustrating the format of a type_names_struc.
[0028] [0028]FIG. 14C is a diagram illustrating the format of a command_entry.
[0029] [0029]FIG. 15A is a diagram illustrating the format of the codec_object.
[0030] [0030]FIG. 15B is a diagram of a CodecEntry.
[0031] [0031]FIG. 16 is a diagram illustrating the format of the data_object.
[0032] [0032]FIG. 17 illustrates the format of a packet.
[0033] [0033]FIG. 18A illustrates a first format that the initial_structure may assume.
[0034] [0034]FIG. 18B illustrates a second format that the initial_structure may assume.
[0035] [0035]FIG. 19 illustrates the format of a payload_struc.
[0036] [0036]FIG. 20 is a diagram illustrating the format of the index_object.
DETAILED DESCRIPTION OF THE INVENTION
[0037] The preferred embodiment of the present invention employs an active stream format (ASF) for holding multiple media streams. ASF is well suited for storage of multimedia streams as well as transmission of multiple media streams over a transport medium. ASF is constructed to encapsulate diverse multimedia streams and facilitates optimal interleaving of respective media streams. ASF specifies the packetization of data and provides flexibility in choosing packet sizes. In addition, ASF enables the specification of a maximum data transmission rate. As such, the packetization and transmission of media streams may be tailored to facilitate the bandwidth limitations of the system on which media streams are stored or transmitted.
[0038] ASF facilitates the use of error correction and error concealment techniques on the media streams. In unreliable transport mediums, such error correction and error concealment is highly beneficial. ASF is independent of media types and is extensible to handle newly defined media types. ASF supports flexible timing approaches and allows an author of an ASF stream to specify the synchronization of events. ASF supports synchronized rendering using a variety of synchronization clock types and provides index information which can be used as markers for lookup to provide playback features such as fast forward and fast reverse.
[0039] [0039]FIG. 1 is a block diagram of an illustrative system for practicing the preferred embodiment of the present invention. FIG. 2 is a flowchart that illustrates the steps that are performed in the illustrative embodiment of FIG. 1. An ASF stream 16 is built by an author (step 20 in FIG. 2) and stored on a storage 14 on a source computer 10 . As will be described in more detail below, ASF allows the author to design the stream for a most efficient storage based on the type of source computer 10 on which it is stored. Sometime later, the ASF stream 16 is transferred over a transport media 17 , such as a network connection, to a destination computer 12 (step 24 in FIG. 2). The destination computer 12 includes a number of renderers 18 for rendering the media types that are present within the ASF stream 16 . For example, the ASF stream 16 may include audio-type data and video-type data. The renderers 18 at the destination 12 include an audio renderer and a video renderer. The renderers may begin rendering data as soon as they receive data prior to the complete transmission of the entire ASF stream 16 (see step 26 in FIG. 2). The renderers need not immediately render the data, but rather may render the data at a later point in time.
[0040] [0040]FIG. 3 depicts the basic logical organization of an ASF stream 16 . It is up to the author to fill in the contents of the ASF stream in accordance with this format. The ASF stream 16 is divisible into a header section 28 , a data section 30 and an index section 49 . In general, the header section is first transmitted from the source computer 10 to the destination computer 12 so that the destination computer may process the information within the header section. Subsequently, the data section 30 is transmitted from the source computer 10 to the destination computer 12 on a packet-by-packet basis and the index section 49 is transmitted. The header section 28 includes a number of objects that describe the ASF stream 16 in aggregate. The header section 28 includes a header_object 32 that identifies the beginning of the ASF header section 28 and specifies the number of objects contained within the header section. FIG. 4 depicts the format of the header_object 32 in more detail. The header_object 32 includes an object_id field 50 that holds a UUID for the header object. The UUID is an identifier. The header_object 32 also includes a size field 52 that specifies a 64-bit quantity that describes the size of the header section 28 in bytes. The header_object 32 additionally includes a number_headers field 54 that holds a 32-bit number that specifies a count of the objects contained within the header section that follow the header_object 32 . An alignment field 55 specifies packing alignment of objects within the header (e.g., byte alignment or word alignment). The architecture field 57 identifies the computer architecture type of the data section 30 at the index section 49 . The architecture field 57 specifies the architecture of these sections as little endian or big endian.
[0041] The header_object 32 is followed in the header section 28 by a properties_object 34 , such as depicted in FIG. 5. The properties_object 34 describes properties about the ASF stream 16 . As can be seen in FIG. 5, the properties object 34 includes an object_id field 56 that holds a UUID and a size field 58 that specifies the size of the properties object 34 . The properties_object 34 also includes a multimedia_stream_id field 60 that contains a UUID that identifies a multimedia ASF stream. A total_size field 62 is included in the properties_object 34 to hold a 64-bit value that expresses the size of the entire ASF multimedia stream.
[0042] The properties_object 34 also holds a created field 64 that holds a timestamp that specifies when the ASF stream was created. A num_packet field 65 holds a 64-bit value that defines the number of packets in the data section 30 . A play_duration field 66 holds a 32-bit number that specifies the play duration of the entire ASF stream in 100 -nanosecond units. For example, if the ASF stream 16 holds a movie, the duration field 66 may hold the duration of the movie. The play_duration field 66 is followed by a send_duration field 67 that corresponds to send the ASF stream in 100-nanosecond units. A preroll field 68 specifies the amount of time to buffer data before starting to play, and the flags field 70 holds 32-bits of bit flags.
[0043] The properties_object 34 includes a min packet_size field 72 and a max_packet_size field 74 . These fields 72 and 74 specify the size of the smallest and largest packets 48 in the data section 30 , respectively. These fields help to determine if the ASF stream 16 is playable from servers that are constrained by packet size. For constant bit rate streams, these values are set to have the same values. A maximum_bit_rate field 76 holds a value that specifies the maximum instantaneous bit rate (in bits per second) of the ASF stream.
[0044] [0044]FIG. 6A is a flowchart illustrating how these values are identified and assigned during authoring of the ASF stream 16 . First, the size of the smallest packet in the data section 30 is identified (step 78 in FIG. 6A). The size of the smallest packet is stored in the min_packet_size field 72 (step 80 in FIG. 6A). The size of the largest packet in the data section 30 is identified (step 82 in FIG. 6A), and the size is assigned to the max_packet_size field 74 (step 84 in FIG. 6A).
[0045] One of the beneficial features of ASF is its ability for facilitating different packet sizes for data of multiple media streams. FIG. 6B shows one example of two different streams 83 and 85 . In stream 83 , each of the packets is chosen to have a size of 512 bytes, whereas in stream 85 each of the packets 48 holds 256 bytes. The decision as to the size of the packets may be influenced by the speed of the transport mechanism over which the ASF stream is to be transmitted, the protocol adopted by the transport medium, and the reliability of the transport medium.
[0046] As mentioned above, the properties_object 34 holds a value in the maximum_bit_rate field 76 that specifies an instantaneous maximum bit rate in bits per second that is required to play the ASF stream 16 . The inclusion of this field 76 helps to identify the requirements necessary to play the ASF stream 16 .
[0047] The header section 28 (FIG. 3) must also include at least one stream_properties_object 36 . The stream_properties_object 36 is associated with a particular type of media stream that is encapsulated within the ASF stream 16 . For example, one of the stream_properties_objects 36 in the header section 28 may be associated with an audio stream, while another such object is associated with a video stream. FIG. 7 depicts a format for such stream_properties_objects 36 . Each stream_properties_object 36 includes an object_id field 86 for holding a UUID for the object and a size field 88 for holding a value that specifies the size of the object in bytes. A stream_type field 90 holds a value that identifies the media type of the associated stream.
[0048] The stream_properties_object 36 holds at least three fields 92 , 98 and 104 for holding information relating to error concealment strategies. In general, ASF facilitates the use of error concealment strategies that seek to reduce the effect of losing information regarding a given sample of media data. An example of an error concealment strategy is depicted in FIG. 8. A sample 106 is divided into four sections S.sub. 1 , S.sub. 2 , S.sub. 3 and S.sub. 4 . When the sample is incorporated into packets in the ASF stream, the samples are distributed into separate packets P.sub. 1 , P.sub. 2 , P.sub. 3 and P.sub. 4 so that if any of the packets are lost, the amount of data that is lost relative to the sample is not as great, and techniques, such as interpolation, may be applied to conceal the error. Each sample has a number of associated properties that describe how big the sample is, how the sample should be presented to a viewer, and what the sample holds. Since the loss of the property information could prevent the reconstruction of the sample, the properties information for the entire sample is incorporated with the portions of the sample in the packets.
[0049] The error_concealment_strategy field 92 holds a UUID that identifies the error concealment strategy that is employed by the associated stream. The error_concealment_len field 98 describes the number of bytes in an error concealment data block that is held in the error_concealment_data entries 104 . The properties associated with the error concealment strategy are placed in the error_concealment_data entries 104 . The number of entries will vary depending upon the error concealment strategy that is adopted.
[0050] The stream_properties_object 36 includes a stream_number field 100 that holds an alias to a stream instance. The stream_properties_object 36 also includes an offset field 94 that holds an offset value to the stream in milliseconds. This value is added to all of the timestamps of the samples in the associated stream to account for the offset of the stream with respect to the timeline of the program that renders the stream. Lastly, the stream_properties_object 36 holds a type_specific_len field 96 that holds a value that describes the number of bytes in the type_specific_data entries 102 . The type_specific_data entries 102 hold properties values that are associated with the stream type.
[0051] The header section 28 (FIG. 3) may also include a number of optional objects 38 , 40 , 42 , 44 , 45 and 46 . These optional objects include a content_description_object 38 that holds information such as the title, author, copyright information, and ratings information regarding the ASF stream. This information may be useful and necessary in instances wherein the ASF stream 16 is a movie or other artistic work. The content_description_object 38 includes an object_id field 110 and a size field 112 like the other objects in the header section 28 . A title_len field 114 specifies the size in bytes of the title entries 119 that hold character data for the title of the ASF stream 16 . An author_len field 115 specifies the size in bytes of the author entries 120 which hold the characters that specify the author of the ASF stream 16 . The copyright_len field 116 holds the value that specifies the length in bytes of the copyright entries 121 that hold copyright information regarding the ASF stream 16 . The description_len field 117 holds a value that specifies the length in bytes of the description entries 122 . The description entries 122 hold a narrative description of the ASF stream 16 . Lastly, the rating_len field 118 specifies a size in bytes of the rating entries 123 that hold rating information (e.g., X, R, PG-13) for the ASF stream content.
[0052] The header section 28 may include a marker_object 40 . The marker_object 40 holds a pointer to a specific time within the data section 30 . The marker_object enables a user to quickly jump forward or backward to specific data points (e.g., audio tracks) that are designated by markers held within the marker_object 40 .
[0053] [0053]FIG. 10A shows the marker-object 40 in more detail. The marker_object 40 includes an object_id field 126 that holds a UUID, and a size field 128 specifies the size of the marker_object in bytes. A marker_id field 130 contains a UUID that identifies the marker data strategy, and a num_entries field 132 specifies the number of marker entries in the marker_object 40 . An entry_alignment field 134 identifies the byte alignment of the marker data, and a name_len field 136 specifies how many Unicode characters are held in the name field 138 , which holds the name of the marker_object 40 . Lastly, the marker_data field 140 holds the markers in a table. Each marker has an associated entry in the table.
[0054] [0054]FIG. 10B shows the format of a marker entry 141 such as found in the marker_data field 140 . An offset field 142 holds an offset in bytes from the start of packets in the data object 47 indicating the position of the marker entry 141 . A time field 144 specifies a time stamp for the marker entry 141 . An entry len field 146 specifies the size of an entry_data field 148 , which is an array holding the data for the marker entry.
[0055] The header section 28 may also include an error_correction_object 42 for an error correction method that is employed in the ASF stream. Up to four error correction methods may be defined for the ASF stream 16 and, thus, up to four error_correction_objects 42 may be stored within the header section 28 of the ASF stream 16 . FIG. 11 depicts the format of the error_correction_object 42 .
[0056] The error_correction_object 42 includes an object_id field 150 and a size field 152 , like those described above for the other objects in the header section 28 . The error_correction_object 42 also includes an error_correction_id 154 that holds UUID that identifies the error correcting methodology associated with the object 42 . The error_correction_data_len field 156 specifies the length in bytes of the error_correction_data entries 158 that hold octets for error correction. The error_correction_object 42 is used by the destination computer 12 (FIG. 1) in playing the ASF stream 16 .
[0057] [0057]FIG. 12 depicts a flowchart of how error correcting may be applied in the preferred embodiment of the present invention. In particular, an error correction methodology such as an N+1 parity scheme, is applied to one or more streams within the ASF stream 16 (step 160 in FIG. 12). Information regarding the error correcting methodology is then stored in the error_correction_object 42 within the header section 28 (step 162 in FIG. 12). The source computer then accesses the error correcting methodology information stored in the error_correction_object 42 in playing back the ASF stream 16 (step 164 in FIG. 12). Error correcting data is stored in the interleave_packets 48 .
[0058] The header section 28 of the ASF stream 16 may also hold a clock_object 44 that defines properties for the timeline for which events are synchronized and against which multimedia objects are presented. FIG. 13 depicts the format of the clock_object 44 . An object_ID field 166 holds a UUID to identify the object, and a size field 168 identifies the size of the clock_object 44 in bytes. A packet_clock_type field 170 identifies the UUID of the clock type that is used by the object. A packet clock_size field 172 identifies the clock size. A clock_specific_len field 174 identifies the size and bytes of the clock_specific_data field 176 which contains clock-specific data. The clock type alternatives include a clock that has a 32-bit source value and a 16-bit duration value, a clock type that has a 64-bit source value and a 32-bit duration value and a clock type that has a 64-bit source value and a 64-bit duration value.
[0059] The ASF stream 16 enables script commands to be embedded as a table in the script_command_object 45 . This object 45 may be found in the header section 28 of the ASF stream 16 . The script commands ride the ASF stream 16 to the client where they are grabbed by event handlers and executed. FIG. 14A illustrates the format of the script_command_object 45 . Like many of the other objects in the header section 28 , this object 45 may include an object_ID field 178 for holding a UUID for the object and a size field 180 for holding the size in bytes of the object. A command_ID field 182 identifies the structure of the command entry that is held within the object.
[0060] The num_commands field 184 specifies the total number of script commands that are to be executed. The num types field 186 specifies the total number of different types of script_command types that have been specified. The type_names field 188 is an array of type_names_struc data structures. FIG. 14B depicts the format of this data structure 192 . The type_name_len field 194 specifies the number of Unicode characters in the type_names field 196 , which is a Unicode string array holding names that specify script command types.
[0061] The command_entry field 190 identifies what commands should be executed at which point in the timeline. The command_entry field 190 is implemented as a table of script commands. Each command has an associated command-entry element 198 as shown in FIG. 14C. Each such element 198 has a time field 200 that specifies when the script command is to be executed and a type field 202 that is an index into the type names array 196 that identifies the start of a Unicode string for the command type. A parameter field 204 holds a parameter value for the script command type.
[0062] The script commands may be of a URL type that causes a client browser to be executed to display an indicated URL. The script command may also be of a file name type that launches another ASF file to facilitate โcontinuous playโ audio or video presentations. Those skilled in the art will appreciate that other types of script commands may also be used.
[0063] The header section 28 of the ASF stream 16 may also include a codec_object 46 . The codec_object 46 provides a mechanism to embed information about a codec dependency that is needed to render the data stream by that codec. The codec object includes a list of codec types (e.g., ACM or ICM) and a descriptive name which enables the construction of a codec property page on the client. FIG. 15A depicts the format of a codec_object 46 . The object_id field 206 holds a UUID for the codec object 46 and the size field 208 specifies the size of the object 46 in bytes. The codec_ID field 210 holds a UUID that specifies the codec type used by the object. The codec_entry_len field 212 specifies the number of CodecEntry entries that are in the codec_entry field 214 . The codec_entry field 214 contains codec-specific data and is an array of CodecEntry elements.
[0064] [0064]FIG. 15B depicts the format of a single CodecEntry element 216 as found in the codec_entry field 214 . A type field 218 specifies the type of codec. A name field 222 holds an array of Unicode characters that specifies the name of the codec and a name_len field 220 specifies the number of Unicode characters in the name field. The description field 226 holds a description of the codec in Unicode characters and the description_len field 224 specifies the number of Unicode characters held within the description field. The cbinfo field 230 holds an array of octets that identify the type of the codec and the cbinfo_len field 228 holds the number of bytes in the cbinfo field 230 .
[0065] As mentioned above, the data section 30 follows the header section 28 in the ASF stream 16 . The data section includes a data_object 47 and interleave_packets 48 . A data object 47 marks the beginning of the data section 30 and correlates the header section 28 with the data section 30 . The packets 48 hold the data payloads for the media stream stored within the ASF stream 16 .
[0066] [0066]FIG. 16 depicts the format of the data_object 46 . Like other objects in the ASF stream 16 , data object 46 includes an object id field 232 and a size field 234 . The data_object 46 also includes a multimedia-stream_id field 236 that holds a UUID for the ASF stream 16 . This value must match the value held in the multimedia_stream_id field 60 in the properties_object 34 in the header section 28 . The data_object 46 also includes a num_packets field 238 that specifies the number of interleave_packets 48 in the data section 30 . An alignment field 240 specifies the packing alignment within packets (e.g., byte alignment or word alignment), and the packet_alignment field 242 specifies the packet packing alignment.
[0067] Each packet 48 has a format like that depicted in FIG. 17. Each packet 48 begins with an initial_structure 244 . The format of the initial_structures 244 depends upon whether the first bit held within the structure is set or not. FIG. 18A depicts a first format of the initial_structure 244 when the most significant bit is cleared (i.e., has a value of zero). The most significant bit is the error_correction_present flag 270 that specifies whether error correction information is present within the initial_structure 244 or not. In this case, because the bit 270 is cleared, there is no error correction information contained within the initial_structure 244 . This bit indicates whether or not error correction is used within the packet. The two bits that constitute the packet_len_type field 272 specify the size of the packet_len field 256 , which will be described in more detail below. The next two bits constitute the padding len_type field 274 and specify the length of the padding_len field 260 , which will also be discussed in more detail below. The next two bits constitute the sequence_type field 276 and specify the size of the sequence field 258 . The final bit is the multiple_payloads_present flag 278 which specifies whether or not multiple payloads are present within the packet. A value of 1 indicates that multiple media stream samples (i.e., multiple payloads) are present within the packet.
[0068] [0068]FIG. 18B depicts the format of the initial_structure 244 when the error_correction_present bit is set (i.e., has a value of 1). In this instance, the first byte of the initial_structure 244 constitutes the ec_flag field 280 . The first bit within the ec_flag field is the error_correction_present bit 270 , which has been described above. The two bits that follow the error_correction-present bit 270 constitute the error_correction_len_type field 284 and specify the size of the error_correction_data_len field 290 . The next bit constitutes the opaque_data flag 286 which specifies whether opaque data exists or not. The final four bits constitute the error_correction_data length field 288 . If the error_correction_len_type field 284 has a value of โ00โ then the error-correction_data_length field 288 holds the error_correction_data_len value and the error_correction_data_len field 290 does not exist. Otherwise this field 288 has a value of โ0000.โ When the error_correction_data_len field 290 is present, it specifies the number of bytes in the error_correction_data array 292 . The error_correction_data array 292 holds an array of bytes that contain the actual per-packet data required to implement the selected error correction method.
[0069] The initial_structure 244 may also include opaque data 300 if the opaque_data bit 286 is set. The initial structure includes a byte of flags 302 . The most significant bit is a reserved bit 304 that is set to a value of โ0.โ The next two bits constitute the packet len_type field 306 that indicate the size of the packet_len field 256 . The next subsequent two bits constitute the padding_len_type field 272 that indicate the size of the padding_len field 274 . These two bits are followed by another 2-bit field that constitutes the sequence_type of field 276 that specifies the size of the sequence field 258 . The last bit is the multiple_payloads_present bit 278 that specifies whether are not multiple payloads are present.
[0070] The initial structure 244 is followed by a stream_flag field 246 that holds a byte consisting of four 2-bit fields. The first two bits constitute a stream_id_type field 248 that specifies the size of the stream_id field 314 within the payload_struc 266 . The second most significant bits constitute the object_id_type field 250 and indicate the number of bits in the object_id field 316 of the payload_struc 266 as either 0-bits, 8-bits, 16-bits or 32-bits. The third most significant two bits constitute the offset_type field 252 , which specifies the length of the offset field 318 within the payload_struc 266 as either 0-bits, 8-bits, 16-bits or 32-bits. The least two significant bits constitute the replicated_data_type field 254 and these bits indicate the number of bits that are present for the replicated_data_len field 320 of the payload_struc 266 .
[0071] The packet 48 also includes a packet_len field 256 that specifies the packet length size. The sequence field 258 specifies the sequence number for the packet. The padding_len field 260 contains a number that specifies the number of padding bytes that are present at the end of the packet to pad out the packet to a desirable size.
[0072] The packet 48 also contains a clock_data field 262 that contains data representing time information. This data may include a clock license that contains a system clock reference that drives the progression of the time line under the timing model and a duration that specifies the effective duration of the clock license. The duration field limits the validity of the license to a time specified in milliseconds. Under the model adopted by the preferred embodiment of the present invention, the source computer 10 issues a clock license to the destination computer 12 that allows the clock of the destination computer 12 to progress forward for a period of time. The progression of time is gated by the arrival of a new piece of data that contains a clock value with a valid clock license that is not expired.
[0073] The packet 48 also includes a payload_flag field 264 that specifies a payload length type and a designation of the number of payloads present in the packet. The payload_flag field 264 is followed by one or more payload_strucs 266 . These structures contain payload information which will be described in more detail below. The final bits within the packet 48 may constitute padding 268 .
[0074] [0074]FIG. 19 depicts the payload_struc 266 in more detail. The stream_id field 314 is an optional field that identifies the stream type of the payload. The object id field 316 may be included to hold an object identifier. An offset field 318 may be included to specify an offset of the payload within the ASF stream. The offset represents the starting address within a zero-address-based media stream sample where the packet payload should be copied.
[0075] The payload_struc 266 may also include a replicated_data_len field 320 that specifies the number of bytes of replicated data present in the replicated_data field 322 . As was discussed above, for protection against possible errors, the packet 48 may include replicated data. This replicated data is stored within the replicated_data field 322 .
[0076] The payload_len field 323 specifies the number of payload bytes present in the payload held within the payload_data field 325 . The payload_data field 326 holds an array of payloads (i.e., the data).
[0077] The ASF stream may also include an index_object 49 that holds index information regarding the ASF stream 16 . FIG. 20 depicts the format of the index_object 49 . The index_object includes a number of index entries. The index_object 49 includes an object_id field 324 and a size field 326 . In addition, the index_object 49 includes an index_id field 328 that holds a UUID for the index type. Multiple index_name_entries may be stored depending on the number of entries required to hold the characters of the name. For example, each entry may hold 16 characters in an illustrative embodiment.
[0078] The index_object includes a time_delta field 330 that specifies a time interval between index entries. The time represents a point on the timeline for the ASF stream 16 . A max_packets field 332 specifies a maximum value for packet_count fields, which will be described in more detail below. A num_entries field 334 is a 32-bit unsigned integer that describes the maximum number of index entries that are defined within the index_info array 336 . This array 336 is an array of index_information structures. Each index_info structure holds a packet field that holds a packet number associated with the index entry and a packet_count field specifies the number of the packet to send with the index entry so as to associate the index entries with the packets. In FIG. 21, the index_info array structure 336 holds N index_information structures and each index_information structure has a packet field 338 A- 338 N and a packet_count field 340 A- 340 N.
[0079] While the present invention has been described with reference to a preferred embodiment thereof, those skilled in the art will appreciate that various changes in form and detail may be made without departing from the intended scope of the invention as defined in the appended claims. For example, the present invention may be practiced with a stream format that differs from the format described above. The particulars described above are intended merely to be illustrative. The present invention may be practiced with stream formats that include only a subset of the above-described fields or include additional fields that differ from those described above. Moreover, the length of the values held within the fields and the organization of the structures described above are not intended to limit the scope of the present invention.
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An active stream format is defined and adopted for a logical structure that encapsulates multiple data streams. The data streams may be of different media. The data of the data streams is partitioned into packets that are suitable for transmission over a transport medium. The packets may include error correcting information. The packets may also include clock licenses for dictating the advancement of a clock when the data streams are rendered. The format of ASF facilitates flexibility and choice of packet size and in specifying maximum bit rate at which data may be rendered. Error concealment strategies may be employed in the packetization of data to distribute portions of samples to multiple packets. Property information may be replicated and stored in separate packets to enhance its error tolerance. The format facilitates dynamic definition of media types and the packetization of data in such dynamically defined data types within the format.
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This application is a continuation of application Ser. No. 07/221,613 filed on Jul. 20, 1988, now abandoned, which is a divisional of application Ser. No. 017,701 filed Feb. 24, 1987 now U.S. Pat. No. 4,772,632.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention is related generally to phenylalanine mustards. More particularly, the present invention is related to the synthesis of new, system L specific amino acid nitrogen mustards useful as antineoplastic agents and as probes for identifying the L-amino acid transport system.
2. State of the Art
The phenyalanine mustards, a group of antitumor agents of the alkylating agent class, were synthesized in the 1950's and found to possess a broad range of antitumor activity aginst both experimental and human neoplasms. These antitumor agents incorporated into their structure the physiological amino acid carrier phenylalanine and the cytotoxic bis(2-chloroethyl) amino group. However, even though effective as antitumor agents, the degree of myelosuppression produced by this group of antineoplastic compounds was found to be undesirable and dose-limiting. Hence, the need to develop more selective antitumor agents inter alia with reduced myelosuppressive activity became obvious.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide improved antineoplastic agents, transported by system L which exhibit reduced myelosuppressive activity compared to the prototype L-phenylalanine mustard (L-PAM).
It is a further object of the present invention to provide a specific probe for identifying the L-amino acid transport system.
It is an additional object of the present invention to provide a method for treating neoplasms by administering to a susceptible or inflicted host the nitrogen mustards of the present invention in an amount effective to inhibit growth of the neoplasm.
Various other objects and advantages will become evident as the detailed description of the present invention proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and many of the attendant advantages of the invention will be better understood upon a reading of the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1 shows proton decoupled 13 C--nmr Spectra of compound 3.
(a) Fully coupled spectrum. (b) H-1 and H-4 decoupled spectrum. (c) H-1, H-3, and H-4 decoupled spectrum. The doublet of doublets ( 1 .spsp.J residual=147 Hz and 3 .spsp.J redisual=7 Hz) centerd at 134.1 ppm is due to c-8;
FIG. 2 shows selectively proton decoupled 13 C--NMR Spectra of compound 2.
(a) Fully coupled spectrum. (b) H-1 and H-4 decoupled spectrum. (c) H-1, H-3 and H-4 decoupled spectrum. The small peaks downfield of the doublet of triplets and 145.8 ppm are due to slight impurities in the sample;
FIG. 3 shows competitive inhibition of the initial velocity of transport of 2-aminobicyclo [2.2.1]heptane-2-carboxylic acid by L--PAM and compound 6.
Panel A: Compound 6. K i =0.22 ฮผMยฑ0.02 [meanยฑS.E. (n=3)].
Panel B: L--PAM. K i =111.6 ฮผMยฑ7.7 [meanยฑS.E. (n=4)].
Initial velocity (v) is expressed as picomoles/10 6 cells/minute.
FIG. 4 shows the antitumor and myelosuppressive activity of L--PAM and compound 6.
Antitumor and myelosuppressive activity was determined as described in the text.
The therapeutic index was calculated by the following equation; ##EQU1##
FIG. 5 shows the comparative rate of dechlorination of L--PAM and Compound 6.
DETAILED DESCRIPTION OF THE INVENTION
The above and various other objects and advantages of the present invention are achieved by providing DL-2-amino-7-bis(2-chloroethyl)amino-1,2,3,4-tetrahydro-2-naphthoic acid or derivatives thereof.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned hereunder are incorporated herein by reference.
All chemical reagents utilized for synthesis were purchased from Aldrich Chemical Co., Milwaukee, Wis. Following the standard procedures, melting points were determined on a Thomas-Hoover apparatus and are uncorrected; proton NMR spectra were determined on Carian T-60 and XL-200 instruments. Chemical shifts are given as ฮด values with reference to Me 4 Si. Elemental analyses were commercially obtained from Galbraith Laboratores, Knoxville, Tenn. Coupled with and selectively decoupled 13 C--NMR studies were conducted on Carian XL-200 instrument on saturated Me 2 SO-d 6 samples. Chemical shifts were determined by reference to the Me 2 SO-d 6 peak at 39.5 ppm relative to Me 4 Si. The spectra were accumulated with a total time of 3.5 sec between transmitter pulses and 30,016 data points. The fully coupled spectra were enhanced by irradiation of the aliphatic proton region during the delay period. Spectra were processed using a resolution enhancement parameter which was manually adjusted for an optimum resolution to noise ratio.
Microscale trimethylsilylation of compounds 6 and 7 was conducted at room temperature (about 22ยฐ C. to 27ยฐ C.) with a large excess of a 1:2 (v/v) solution of bis(trimethylsilyl) trifluoroacetamide (BSTFA) and redistilled acetonitrile. Gas chromatograhy (GC) of these derivatives was accomplished with a Varian 2740 GC equipped with a flame ionization detector and interfaced to a Spectra-Physics 4100 computing integrator. A 1.83 mx 2 mm i.d. glass column packed with 3% OV-17 on 100/120 mesh Gas-Chrom Q was operated with a temperature program from 220ยฐ F. to 280ยฐ F. at a 4ยฐ/min after being held at the inital temperature for 2 min. Typical GC operating conditions employed as injector and detector temperature of 250ยฐ F., a 30 mL/min flow rate for both helium carrier gas and hydrogen, and a 300 mL/min flow rate for air.
Electron impact mass spectra were obtained on a DuPont instrument 21-492B interfaced to a VG 2035 data system. Samples were introduced via a Varian 2740 GC (492) in a standard manner and interfaced to the mass spectrometer by a single-stage glass jet separator. Typical operating conditions were: jet separator, 210ยฐ; transfer line, 230ยฐ; ion source, 245ยฐ; acceleration voltage, 1.6 kV; resolution, 1000;electron energy, 75 eV; ionizing current 250 ฮผA; scan speed, 2 s/decade.
DL-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid [carboxyl- 14 C] (4.78 mCi/mmol) was obtained from New England Nuclear, Boston, Mass. RPMI (Roswell Park Memorial Institute) 1630 medium, McCoy's 5A medium and Dulbecco's phosphate buffered saline were obtained from GIBCO Laboratories, Chagrin Falls, Ohio. Salt-free bovine serum albumin was obtained from Advanced Biotechnologies, Inc., Silver Spring, Md. Versilube F-50 silicone oil was obtained from the General Electric Co., Waterford, N.Y. Unless noted otherwise, all procedures or tests mentioned herein were performed following standard methodology well known to one of ordinary skill in the art to which this invention belongs.
SYNTHESIS OF SPECIFIC COMPOUNDS
DL-7'-Nitrospiro[2,5-imidazolidinedione-4,2'(1'H-3', 4'-dihydronaphthalene](2) and DL-5'-nitrospiro[2,5-imidazolidinedione-4,2'(1'H)-3', 4'-dihydrohaphthalene](3)
ฮฒ-Tetralone hydantoin (20.0 g, 0.092 mol) was added during 4 h to stirred concentrated nitric acid (200 ml, d=1.42) at room temperature (about 22ยฐ C.-27ยฐ C.). The reaction mixture was then stirred for an additional hour, and water (300 ml) was added slowly. A mixture of two mono-nitro compounds separated out as a granular solid (19.6 g, 81%), mp 240ยฐ C., as described by Mauger and Ross, Biochem Pharmacol., 1962, 11: 847. A small sample (0.4 g) of this mixture was separated on a Waters LC-500 preparative HPLC apparatus using two silica gel columns and eluting with ethyl acetate/hexane (1:1). The 7'-nitro isomer (mp 300ยฐ C.) as well as the 5'-nitro isomer (mp 260ยฐ C. dec.) were characterized by 1 H-- and 13 C--NMR studies (FIGS. 1 and 2).
Compound 2 (slower moving isomer; 1 H--NMR (Me 2 SO-d 6 ) ฮด1.95 (m, 2H, CH 2 -3', 3.10 (M, 4H, CH 2 -4'), 7.35 (D, 1H, J=8.2 Hz, H5'), 7.92 (m, 2H, H6' and H8'), 8.35 (s, 1H, N 3 --H), 10.70 (s, 1H, N 1 --H); 13 C--NMR (Me 2 SO-d 6 ) 25.2 (C-4'), 29.6 (C-3'), 36.7 (C-1'), 60.1 (C-2'), 120.7 (C-6'), 123.7 (C-8'), 129.7 (C-5'), 134.6 (C-8'a), 143.5 (C-4'a), 145.5 C-7'), 156.2 (C-4), 177.7 (C-2).
Compound 3 (faster moving isomer); 1 H--NMR 1.95 (m, 2H, CH 2 -3'), 3.10 (m, 4H, CH 2 -1' and CH 2 -4'), 7.40 (m, 2H, H-7' and H-8'), 7.78 (dd, 1H, J=7.8 Hz, J'=1.6 Hz, H-6'), 8.30 (s, 1H, N 3 --H), 10.75 (s, 1H, N 1 --H); 13 C--NMR (Me 2 So-d 6 ) ฮด21.9 (C-4'), 29.3 (C-3'), 37.0 (C-1'), 59.7 (c-2'), 122.2 (C-6'), 126.5 (C-7'), 129.6 (C-4'a), 134.1 (C-8'), 136.0 (C-8'a), 148.9 (C-5'), 156.2 (C-4), 177.7 (C-2).
DL-5'-[Bis(2-hydroxyethyl)amino]sprio[2,5-imidazolidinedione-4,2'(1'H)-3', 4'-dihydronaphthalene] (5a) and DL-7'-[bis(2-hydroxyethyl-amino]sprio[2,5-imidazolidinedione-4,2'(1'H)-3', 4'-dihydronaphthalene] (4a)
The mixture of nitro compounds (5.0 g, 0.019 mol) was dissolved in 70 ml of DMF and hydrogenated at 30 psi with 10% Pd on charcoal for 90 min. The filtered solution was evaporated to dryness and dissolved in a minimun amount of 1N HCl. Concentrated ammonium hydroxide was then added to the solution and the precipitated product washed with water and dried to give 3.2 g (72%) of the momoamines, mp 300ยฐ C. A mixture of amines (5 g), ethylene oxide (15 ml), acetic acid (25 ml) and water (25 ml) was stirred at ambient temperature (about 22ยฐ C.-27ยฐ C.) for 17 h. The solid obtained after evaporation on TLC analysis (silica gel, 10% isopropanol in ethyl acetate) showed two close spots, ca. R f =0.4, corresponding to the two isomers. The solid was recyrstallized three times from water giving 0.250 g (3.6%0 of pure 5a, mp 187ยฐ-190ยฐ C.; NMR (Me 2 SO-d 6 ) ฮด1.77 (m, 2H, CH 2 -3'), 2.68 (m, 4H, CH 2 -1' and CH 2 -4'), 3.00 (m, 4H, NCH 2 CH 2 OH), 3.40 (m, 4H, NCH 2 CH 2 OH), 4.38 (t, 2H, J=5.3 Hz, OH, D 2 O exchanged), 6.77 (dd, 1H, J=6.3 Hz, J'-2.0 Hz, H-6'), 7.04 (m, 2H, H-7' and H-8'), 8.36 (s, 1H, N 3 --H), 10.66 (s, 1H, N 1 --H).
Anal. (C 16 H 21 N 3 O 4 ) C, H, N.
The remaining aqueous solution was evaporated, triturated with methanol and the residual solid recrystallized twice from water to give 0.3 g (4.3%) of pure 4a, mp 190ยฐ-192ยฐ C., NMR (Me 2 SO-d 6 ) ฮด1.79 (m, 2H, CH 2 -3'), 2.70-3.20 (m, 4H, CH 2 -1' and CH 2 -4'), 3.31 (m, 4H, NCH 2 CH 2 OH), 3.45 (m, 4H, NCH 2 CH 2 OH), 4.67 (br t, 2H, OH, D 2 O exchanged), 6.33 (d, 1H, J=2.0 Hz, H-8'), 6.47 (dd, 1H, J=8.4 Hz, J'=2.0 Hz, H-6'), 6.86 (d, 1H, J=8.4 Hz, H-5'), 8.23 (s, 1H, N 3 --H), 10.63 (s, 1H, N 1 --H).
Anal. (C 16 H 21 N 3 O 4 ) C, H, N.
DL-5'[Bis(2-chloroethyl)amino]spiro[2, 5-imidazolidinedione-4,2'(1'H)-3',4'-dihydronaphthalene] (5b)
Compound 5a (1.0 g, 0.0031 mol) was stirred overnight with freshly distilled POCl 3 (10 ml, 0.1 mol) at room temperature. The reaction mixture was evaporated to a syrup and then coevaporated with benzene. The residue obtained was dissolved in concentrated HCI and evaporated again. The remaining semisolid was purified by silica gel chromatography with ethyl acetate to give 0.38 g (34%) of 5b as a white solid, mp 180ยฐ-184ยฐ C.; NMR (Me 2 SO-d 6 ) ฮด1.79 (m, 2H, CH 2 -3'), 2.70-3.30 (m, 4H, CH 2 -1' and CH 2 4'), 3.32 (m, 4H, NCH 2 CH 2 Cl), 3.53 (m, 4H, NCH 2 CH 2 Cl 6.88 (dd, 1H, J=3.1 Hz, J'=1.4 Hz, H-6'), 7.10 (m, 2H, H-7' and H-8'), 8.39 (s, 1H, N 3 -H), 10.69 9s, 1H, N --H).
Anal. (C 16 H 19 N 3 Cl 2 O 2 ), C, H, N, Cl.
This compound was also isolated from a reaction starting with a mixture of both bis(2-hydroxyethyl) amino compound. After workup, column chromatography over silica gel with ethyl acetate-hexane (1:1) produced a faster moving isomer which corresponded exactly to this material.
DL-7'-[Bis(2-chloroethyl)amino]spiro[2,5-imidazolidine-4,2'(1'H)-3',4'-dihydronaphthalene] (4b)
In reaction similar to that described above, compound 4a was converted to 4b which was isolated as a white solid, mp 212ยฐ C., NMR (Me 2 SO-d 6 ) ฮด1.70 (m, 2H, CH 2 -3'), 2.70-3.30 (m, 4H, Ch 2 -1' and Ch 2 4'), 3.35-3.60 (m, 8H, NCH 2 CH 2 Cl), 6.43 (d, 1H, J=2.0 Hz, H-8'), 6.56 (dd, 1H, J=8.6 Hz, J'=2.0 Hz, H-6'), 6.93 (d, 1H, J=8.6 Hz, H-5'), 8.25 (s, 1H, N 3 --H), 10.64 (s, 1H, N 1 -H).
Anal. (C 16 H 19 N 3 Cl 2 O 2 ) C, H, N, Cl.
This compound was also isolated from a reaction starting with a mixture of both bis(2-hydroxyethyl)amino compounds. After workup, column chromatography over silica gel with ethyl acetate-hexane (1:1) produced a slower moving isomer which corresponded exactly to this material.
DL-2-Amino-7-bis(2chloroethyl)amino-1,2,3,4-tetrahydro-2-naphtholic acid. Hydrochloride salt (6)
The hydantoin mustard 4b (0.15 g) was dissolved in concentrated HCl and heated at 140ยฐ C. for 16 h in a sealed tube. The reaction mixture was evaporated in the cold (about 4ยฐ C. or less) and the residue dissolved in a small volume of 1N HCl and extracted with ethyl acetate several times. The aqueous fraction was lyophilized to give 40 mg of the 7-isomer mustard 6 which was 87% pure by GC-MS when analysed as a persilylated derivative;; mass spectrum, m/z (relative intensity) 474 (M + , 5.7), 459 (M--CH 3 , 2.2), 431 (M--CH 3 --C 2 H 4 , 2.9) 402 M--Me 3 Si+H, 3.7), 385 (M--Me 3 SiNH 2 , 1.9), 357 (M--Me 3 SiO 2 C, 100).
DL-2-Amino-5-bis-(2-chloroethyl) amino-1,2,3,4-tetrahydro-2-naphthoic acid. Hydrochloride salt (7)
Following similar procedure, the 5-isomer mustard 7 was isolated as a lyophilized powder which was 92% pure by GC-MS when analyzed as a persilylated derivative; mass spectrum, m/z (relative intensity) 474 (M + , 1.0), 459 (M--CH 3 , 2.3), 431 (M--CH 3 --C 2 H 4 , 2.4), 402 (M--Me 3 Si+H, 1.7), 357 (M--Me 3 SiO 2 C, 100).
Transport Studies.
Murine L1210 Leukemia cells were grown in RPMI 1630 medium containing 16% heat-inactivated fetal calf serum and passaged over 2-3 days when cell densities approached 1ร10 6 cells/ml. For experimental studies, cells were harvested from growth medium and washed twice in transport medium composed of, CaCl 2 . 2H 2 O (0.7 mM), MgCl 2 .6H 2 O) 0.5 mM, choline chloride (125 mM), HEPES (25 mM), and salt-free bovine serum albumin (0.1 mM). The final pH of the transport medium was 7.4. Cells were then incubated with 1.5 ฮผM or 3.0 ฮผM 2-amino-bicyclo [2.2.1]heptane-2-carboxylic acid [carboxyl- 14 C] (BCH) along with the indicated concentration of either L-phenylalanine mustard or DL-2-Amino-7-bis(2chloroethyl) amino-1,2,3,4-tetrahydro- 2-naphthoic acid (6). The initial rate of transport of BCH was terminated at 40 sec by centrifugation of 1ร10 6 cells through Versilube F-50 silicone oil. The cell pellets were solubilized in 0.2N NaOH, acidified and counted in a Packard 460C liquid scintillation counter.
Evaluation of Antitumor and Myelosuppressive Activity.
Murine L1210 leukemia cells were grown as described above under transport studies. Cells were harvested and washed twice in a fresh growth medium. Bone marrow cells were removed from femurs of male CDF 1 mice and washed twice in RPMI 1630 containing 16% heat-inactivated fetal calf serum. A cell suspension containing both 100 tumor cells/Ml and 100 CFU-C/ml (1.0ร10 5 nucleated cells/ml) was prepared and the cells co-exposed for 45 min to the respective drug in RPMI 1630 containing 16% heat-inactivated fetal calf serum. The cells were then harvested, washed twice in McCoy's 5A medium supplemented with 10% fetal bovine serum, 20 units/ml penicillin and 20 ฮผg/ml streptomycin. Cell survival was assessed following 1 week of growth in the same medium at 37ยฐ in a humidified atmosphere of 5% CO 2 . Experimental points represent the mean of three separate platings. Pregnant mouse uterine extract was used as a source of colony-stimulating factor for the bone marrow. The presence of either cell type had no effect on the plating efficiency of the other.
Determination of Alkylating Potency and Half Life (t 1/2 ).
The reaction of L-phenylalanine mustard and DL-2-Amino-7-bis(2-chloroethyl)amino-1,2,3,4-tetrahydro-2 -naphthoic acid (6) with ฮณ-(4-nitrobenzyl)pyridine was used to determine both alkylating potency and stability of the drugs in aqueous solution containing physiological concentrations of the chloride ion (Dulbecco's phosphate buffered saline). The drugs were made up as 65 mM stock solutions in 75% ethyl alcohol containing equimolar hydrochloric acid and diluted 200 fold into Dulbecco's phosphate buffered saline to initiate the study. One ml aliquots were removed at time=0, 7.5, 15, 60 and 135 min, the pH adjusted to 4.8 with 0.1M sodium acetate and residual alkylating activity determined as described by Truhaut et al. Clin. Chim. Acta, 1963, 8: 235, following reaction with ฮณ-(4-nitrobenzyl)-pyridine. Experimental points represent the mean of three separate determinations.
Of course, the general procedures for the preparation of the hydantoin and amino acid nitrogen mustards are well known and found in such publication as Mauger and Ross, supra. However, at an early stage of the synthesis, Mauger and Ross were unable to separate and identify the mixture of the two mononitro derivatives obtained from ฮฒ-tetralone hydantoin. Despite their success in the separation of one of the isomers at the bis-(2-hydroxy-ethyl)amino stage and its conversion to the final target amino acid mustard, the assigned location of the substituent for this isomer was still uncertain. Based on the comparative rates of hydrolysis of the final product with a group of standard tetrahydronaphthaIene nitrogen mustards, the bis)2-chloroethyl)amino side chain was postulated to be a either the 5- or 8- position (Mauger and Ross, supra). It is noted that even the successful separation of the isomers at the nitro stage and their chemical oxidation to a nitrophthalic acid product, as suggested by these authors, could not have solved the issue of the substituent position.
The applicants resolved this issue by separating small amounts (ca. 200 mg) of both nitro-substituted isomers (see scheme 1) which were then analyzed by proton and carbon NMR spectoscopy to determine the exact position of the nitro group in the molecule (vide infra). It was easier, nevertheless, to continue the synthesis and perform the separation of isomers at the bis (2-hydroxyethyl)amino stage as described by Mauger and Ross, or even at the bis(2-chloroethyl)amino stage, prior to the hydrolysis of the hydantoin ring, as described more fully herein. ##STR1##
The less water soluble bis(2-hyroxyethyl)amino isomer, mp 187ยฐ-190ยฐ C. (which corresponded to the material isolated by Mauger and Ross having a mp of 185ยฐ-187ยฐ C.), had to be either the 5- or the 8-substituted isomer based on its H--NMR spectrum that showed a pattern consistent with a 1,2,3-trisubstituted benzene (Table 1, compound 5a). This agreed well with the two alternative substitution sites suggested by the same authors which was based, as mentioned before, on the rate of hydrolysis of the final nitrogen mustard product (Mauger and Ross, supra) However, since the 13 C--NMR spectral studies perfomed on the precursor nitro-substituted isomers 2 and 3 demonstrated that these compounds carried the nitro substituent exclusively and the 5- or the 7- position, the correct structure for the less water soluble bis(2-hydroxyethyl)amino isomer had to be 5a and the products derived from it has to correspond to the 5-subsituted derivatives. The more water soluble bis-(2-hydroxyethyl)amino isomer, which was isolated from the mother solution (mp 190ยฐ-192ยฐ C.), had a 1 H NMR spectrum consistent with a 1,2,4-trisubstituted benzene derivative (Table 1, compound 4a) and therefore had to correspond to the 7-substituted isomer.
Table 1
H--NMR Resonances of Aromatic Protons in Compouns 4 and 5. ##STR2##
______________________________________Compound H-5 H-6 H-7 H-8______________________________________5a -- 6.77 7.04 7.04(5-isomer) dd m m J.sub.6,7 = 6.3 J.sub.6,8 = 2.04a 6.86 6.47 -- 6.33(7-isomer) d dd d J.sub.5,6 = 8.4 J.sub.6,5 = 8.4 J.sub.8,6 = 2.0 J.sub.6,8 = 2.0______________________________________ s=singlet, d=doublet, dd=doublet of doublets, m=multiplet. Chemical shifts are in parts per million and J valves in Hertz. Al spectra were measured at 200 MHz in Me SO-d.
The remaining steps were performed essentially in the same manner as described by Mauger and Ross, supra; for both of the isomers 5- and 7-bis(2-hydroxyethyl)-amino compounds to give the two rather unstable amino acid mustards 6 and 7 (Scheme 1). These compounds were readily hydrolyzed in aqueous solution to one arm mustards as confirmed by GC-MS (gas chromatographic and mass spectral) studies. For this reason the final products were not manipulated or purified any further and they were biologically evaluated as such. According to GC-MS studies, the purity for both isomers was about 90%. Reversed phase HPLC for the bologicaIly important 7-isomer revealed a somewhat lower purity (about 74%) possible due to partial hydrolysis in the aqueous phase of the system (30 min gradient from water to 0.5M KH 2 PO 4 ). All the other intermediates prior to the final amino acid mustards 6 and 7 were analytically pure as shown by spectral and combustion analysis.
Carbon NMR Spectral Studies
Absolute assignment of the site of nitration was accomplished by selective proton decoupling of the 13 C--NMR. The faster moving isomer of the two nitro compounds collected after preparative HPLC showed a distinct 1,2,3 aromatic substitution pattern in its proton NMR spectrum indicating either 5- or 8-nitration. The fully coupled 13 C--NMR showed the nonprotonated aromatic carbons at 148.9, 136.0 and 129.6 ppm (vide infra). The nitrated carbon resonance position (148.9) could be assigned based on its coupling pattern (doublet of doublets) since in either the 5- or the 8-nirto isomer, this carbon would show a 2 J (absolute valueห3 Hz) 17 and a 3 J (ห9 Hz) 17 coupling to the neighboring aromatic protons (FIG. 1a). At this point, assignment of the other two nonprotonated carbon resonances (C-4a and C-8a) could be achieved by determining which showed coupling to the methylene protons at C-3 and was therefore C-4a. Coupling of C-8a to these methylene protons ( 4 J) would be very small and therefore undetectable at the available resolution. Selective decoupling of the H-1 and H-4 protons by irradiation of the overlapping resonances with decoupling power of 0.01 Watt simplified the resonances at 136.0 to a sharp doublet and the resonances at 129.6 to a broad triplet (FIG. 1b). Irradiation at a position midway between the overlapping H-1 and H-4 resonances and the H-3 resonance with a decoupling power of 0.02 Watt resulted in complete decoupling of the aliphatic protons and further simplifed the resonance at 129.6 ppm to a sharper tiplet (FIG. 1C). The resonance at 129.6 ppm is therefore coupled to the H-3 protons and is C-4a. That C-4a is a triplet with a residual coupling constant of the magnitude of an aromatic 3 J (ห5.2 Hz) 17 indicates that it is coupled through three bonds to two aromatic protons. These aromatic protons must be a H-6 and H-8 and the nitro group must therefore be at the 5 position (compound 3). The C-8a resonance at 136.0 is simplified to a doublet due to the residual coupling with H-7 ( 3 J): coupling with H-8 ( 2 J) is expected to be small (ห1 Hz) 17 and is not resolved. X-ray crystallographic analysis performed on 5a confirmed the position of the side chain at C-5 in accordance with the NMR tests.
Similar strategy allowed the structural assignnent of the second compound as the 7-nitro isomer (compound 2). In the aliphatic proton decoupled spectrum (FIG. 2c) the nitrated carbon (C-7) at 145.5 ppm appears as a doublet of triplets due to coupling through two bonds to H-6 and H-8 and through three bonds the H-5. C-4a, at 143.5 ppm, identified by its coupling to methlene protons at C-3, is coupled to two aromatic protons (h-6 and H-8 through three bonds and appears as a triplet. C-8a (134.6 ppm) is coupled to only one aromatic proton (H-5) through three bonds and is therefore a doublet.
Biological Tests
Compount 6 is an extremely potent competitive inhibitor of System L in murine L1210 leukemia cells (FIGS. 3). Inhibition analysis of the initial rate of transport of BCH indicated that the K I is approximately 0.2 ฮผM, 500-fold lower than that of L-phenylalanine mustard (K i =100 ฮผM). This value indicates that the compound is a 25 to 50-fold more effective inhibitor of System L than BCH and approximately 40-fold more potent that 2-amino-1,2,3,4-tetrahydro-2-naphthoic acid (Vistica, et al., "Rational Basis for Chemotherapy", New York, 1983; p.475). Compound 7, on the other hand, was a weaker inhibitor of System L with a K I of 15.2 ฮผM (data not shown).
L-Phenylalanine mustard, the prototype amino acid nitrogen mustard, is 2.5 times more cytotoxic to bone marrow progenitor cells than to murine L1210 leukemia cells (FIG. 4). The LD 90 concentration of L-PAM for murine CFU-C was 14 ฮผM as compared to 35 ฮผM for murine L1210 leukemia cells. Compound 6, on the other hand, possesses both enhanced antitumor activity (LD 90 =26.5 ฮผM) and reduced myelosuppressive activity (LD 90 =23.8 ฮผM) (FIG. 4). A comparison of the therapeutic indices for L-PAM and Compound 6 indicated a 2-2.5-fold improvement for the latter amino acid nitrogen mustard.
Compound 6 and L-PAM possess identical alkylating capacity as determined by their reaction with ฮณ-(4-nitrobenzyl)pyridine (FIG. 5). However these two amino acid nitrogen mustards differ significantly in their rate of dechlorination. Compound 6 has a half life (t 1/2 ) of approximately 40 minutes as compared to a 120 minutes for L-PAM.
The results presented here indicated that Compound 6 is the most potent inhibitor of System L, the sodium-independent leucine-preferring amino acid transport system. It is 25-50 times more effective than BCH and has a 500-fold greater affinity for System L than L-PAM. In addition to differing from L-PAM in its affinity for System L, compound 6 exhibits both enhanced anititumor and reduced myelosuppressive acitivity which results in a 2-fold improvement in the therapeutic index. Furthermore, the rate of dechlorination of compound 6 differs significantly from L-PAM, resulting in a 2-3-fold decrease in the t 1/2 . Without being bound to any theory, it is hypthesized that this more rapid conversion to a non-cytotoxic derivative may be the reason for the observed increase in selectivity of compound 6. This could occur if the time required to achieve steady state concentrations of the drug in tumor cells is sufficiently short compared to its t 1/2 . Residual drug would then be more rapidly dechlorinated resulting in a reduction of host toxicity. However, it is believed that the increase in selectivity may be primarily due to the avidity of compound 6 for System L. The high-affinity of the drug for that carrier system would result in higher intracellular concentrations of the drug in tumor cells; conversely, with an altered or absent System L in progenitor cells, lower concentrations would be expected in this sensitive host tissue, the result being a reduction in myelosuppression.
The compound of the present invention, such as DL-2-amino-7-bis (2-chloroethyl)amino-1,2,3,4-tetrahydro-2-naphthoic acid, of course has several utilities. First, the data with respect to murine tumor cells and murine bone marrow cells indicate that this drug is a potent antineoplastic agent which also exhibits improved selectivity against tumor cells. Specifically, it is less toxic to the bone marrow, the result being a reduction in myelosuppression at the therapeutic doses.
Secondly, since the drug exhibits the highest affinity of any compound ever described for the amino acid transport System L, it is useful in the treatment of brain tumors. System L is the only transport carrier which exists on the luminal side of the blood brain barrier. Administration of this drug, for example, intravenously, would allow the penetration of the drug through the blood brain barrier into the brain where the drug's antineoplastic properties would be effective against brain tumors.
Furthermore, by virtue of its high-affinity for the System L carrier, the drug can be used as a probe to isolate a cellular component amongst a heterogeneous mixture of other cellular macromolecules. This is accomplished as follows.
Cells are harvested from growth medium, centrifuged for 6 minuts at 300รg and then suspended in Dulbecco's phosphate buffered saline (PBS), pH 7.4, at 10 8 cells/ml The cells are disrupted by sonication and the sonicate treated with DNAse and RNase. The sonicate is then applied to a Sephadex G-25 column and the column eluted with PBS. The column void volume is collected and treated with 100 ฮผM of DL-2-amino-7-bis (2-chloroethyl) amino-1,2,3,4-tetrahydro-2-naphthoic acid with or without 1 mM 2-aminobicyclo [2.2.1] heptane-2-carboxylic acid. The sonicate is applied to a Sephadex G-25 column and eluted with PBS. The latter procedure removes both unreacted and dechlorinated drug. The Sephadex G-25 eluant (void volume) is appled to a Sephraose 2B column and eluted with PBS with and without 1 mM 2-aminobicyclo [2.2.1] heptane-2-carboxylic acid. Fractions are collected and monitored at A 220 nM on a standard spectrophotometer. That fraction which exhibit absorbance at 220 nM and which is sensitive to (that is, inhibited by) 2-aminobicyclo [2.2.1] heptane-2-carboxylic acid is indicative of the presence of L - amino acid transport system and such fractions may be pooled for further study, if necessary.
Of course, the compounds of the present invention can also be labelled, for example with radioisotopes and such raiolabelled compounds employed cytochemically or otherwise, for identification of the system L- carrier.
Of course the pharmaceutical composition comprising the new antineoplastic compound(s) of the present invention as an active ingredient in an amount sufficient to produce antineoplastic effect in a susceptible host or tissue and a pharmaceutically acceptable carrier, can also be easily prepared from the disclosure contained herein. Such pharmaceutical compositions may be in any suitable form such as a liquid, solid or semi solid, for example an injectable solution, tablet, capsule, ointment, lotion and the like. It could be applied either topically or systemically or both.
It is understood that the examples and embodiments described herein are for illustrative purposed only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims.
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New antineoplastic, system - L specific amino acid nitrogen mustards with reduced myelosuppressive effect are disclosed. A method for identifying and isolating the cellular component comprising the L - amino acid transport system is also described.
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FIELD OF THE INVENTION
[0001] The present invention relates to material handling devices and, more specifically, to a mechanical pinch clamping assembly.
BACKGROUND OF THE INVENTION
[0002] Moving large objects such as rocks for use in a rock wall frequently requires handling devices such as grappler assemblies. Often a hydraulic thumb can be used with a fork or lift to capture the object to be moved. In lieu of the thumb attachment a piece of chain or similar material is used to wrap around the object to be moved, which is time consuming. This also poses a safety issue because the chain tends to slip as a person tries to pick up the rock, together with the fact that you may have to take many attempts to get the chain to actually grip the rock.
SUMMARY OF THE INVENTION
[0003] In one aspect of the invention, an apparatus for lifting objects includes two or more tines each having first and second ends. The first ends define an attachment point and the second ends define hooked portions. The two or more tines pivotally secure to a spreader between the first and second ends thereof.
[0004] In another aspect of the invention, the spreader defines at least two slots each sized to receive one of the two or more tines, the slots extend radially outward from a common point and are uniformly and circumferentially distributed about the common point and radially offset from the common point by a same distance. The two or more tines may have an oblong cross section at a point of attachment to the spreader such that the two or more tines each have a longer dimension of the oblong cross section thereof aligned with a longer dimension of a slot. In another aspect, the two or more tines are pivotally secured to the spreader by pins each spanning at slot of the at least two slots and passing through a tine of the at least two tines.
[0005] In another aspect, at least two chain portions each secured at a first end thereof to the attachment point of one of the tines of the two or more tines, the at least two chains being secured to one another at second ends thereof. The two or more tines may include an inner surface facing the spreader, the attachment point and hooked portion both protruding inwardly toward the spreader from the inner surface. The attachment point may protrude inwardly toward the spreader from the inner surface a greater extent then the hooked portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings:
[0007] FIG. 1 is an isometric view of a clamping assembly in accordance with an embodiment of the invention.
[0008] FIG. 2 is a top plan view of a spreader in accordance with an embodiment of the invention.
[0009] FIGS. 3A and 3B illustrate a tine in accordance with an embodiment of the invention.
[0010] FIGS. 4A through 4C are side views showing use of the clamping assembly in accordance with an embodiment of the invention.
[0011] FIG. 5 illustrates a clamping assembly coupled to a hydraulically actuated shovel of a tracked vehicle in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] Referring to FIG. 1 , a clamping assembly 10 may include two or more, preferably three, tines 12 each mounted to a spreader 14 . The spreader 14 may include two or more slots 16 , preferably three, radiating outwardly from a common center. The tines 12 may each be inserted within one of the slots 16 and pinned in the slot 16 by means of pins 18 . The pins 18 may be bolts or other fasteners passing through both the slots 16 and tines 12 positioned therein. The tines 12 are coupled to one or more lines 20 above the spreader 14 . In the illustrated embodiment, the lines 20 are chains and may be coupled to the pins 18 by means of shackles or other linking structure. However, the lines 20 may be cables, ropes, or other type of line capable of supporting the loads for a given application. In the illustrated embodiments, the lines 20 secure to a common coupler 22 , such as by securing a link of each chain 20 to a common ring, or separate rings, mounted to a common coupler 22 . The coupler 22 may be mounted to another line, such as a chain, that is mounted to a device for raising and lowering the clamping assembly 10 . In some embodiments, the coupler 22 may incorporate a swivel that allows for rotation of the clamping assembly 10 . For example, the coupler 22 or a line to which it is coupled may be coupled to hydraulically actuated arm of a front loader, back hoe, or other machinery either directly or by mounting to a shovel mounted to such an arm. The tines 12 , spreader 14 , chains 20 , and other components of the clamping assembly 10 may be made of any suitable material for the loads of a given application. In some embodiment, some or all of the components of the clamping assembly 10 are formed of mile steel plate for ease of manufacturing.
[0013] Referring to FIG. 2 , as noted above the slots 16 extend outwardly from a common center. In particular, each slot 16 may be offset from the common center by a distance 24 and have an extent 26 outward from the offset distance 24 . As is readily apparent, the extent 24 is many times larger, e.g. between 10 and 20 times larger, than the width of the slots 16 , e.g. a width tangential to a circle around the common center. Apertures 28 for receiving the pins 18 may pass through the spreader 14 in the vicinity of each slot 16 . In particular, apertures 28 may pass through the spreader perpendicular to the slots such that portions of each aperture are positioned on either side of a slot 16 . For example, apertures may extend through the spreader 14 in a tangential direction to a ring about the common center.
[0014] In some embodiments, cutouts 30 , such as arcuate cutouts 30 , defined in the spreader 14 and positioned between slots 16 may leave prongs or strips of material on either side of the slots 16 and reduce the amount of material required to form the spreader 14 . Alternatively, in some embodiments, the spreader 14 may have a generally circular shape having the slots 16 defined therein and the cutouts 30 may be omitted.
[0015] Referring to FIGS. 3A and 3B , a tine 12 may be understood with respect to a vertical direction 32 and a horizontal direction 34 that correspond generally to the horizontal and vertical directions of the clamping assembly 10 in use, though variation from an absolute horizontal and vertical direction may occur. The tine 12 may define an aperture 36 , or other attachment structure such as a slot or hook, for securing to a line 20 . The tine 12 may also define an aperture 38 for receiving a pin 18 securing the tine 12 to the spreader 14 . A hooked portion 40 of the tine 12 is used to engage and lift objects. In the illustrated embodiment, the end of the spreader 14 is closer to the aperture 36 than to the end of the hooked portion 40 . For example, along a vertical separation between the aperture 36 and the end of the hooked portion 40 may be more than two times, preferably more than four times, and more preferably eight times, a vertical separation between apertures 36 and 38 . An inner surface 42 of the tine may extend along the vertical direction 32 between the hooked portion 40 and the apertures 36 , 38 . In some embodiments, the vertical direction 32 may be defined as being parallel to the inner surface 42 . In other embodiments, the inner surface may be curved, angled, or have some other shape. Stated differently, the apertures 36 , 38 and the distal end of the hooked portion 40 like along a concave curve that faces inwardly toward the other tines 12 , i.e. the common center of the spreader 14 . In this manner, pivoting due to an upward force on the aperture 36 may pivot the hooked portion 40 inward and provide a surface positioned under an object to facilitate lifting.
[0016] The aperture 36 may be located closest to a common center of the spreader 14 along the horizontal direction 34 . The aperture 38 may be spaced outwardly from the aperture 36 (e.g. away from the common center) by a distance 44 and the end of the hooked portion 40 may be spaced inwardly (closer to the common center) from the aperture 38 by a distance 46 . The distance 46 may be less than the distance 44 , e.g. between 90 and 60 percent of the distance 44 .
[0017] As is apparent in FIG. 3A , the hooked portion 40 may include a curved surface that transitions from a vertical direction aligned with the inner surface 42 to a horizontal portion perpendicular to the inner surface 42 . The transition may be a circular arc or some other smooth surface or may be a simple angled junction. Although the distal end of the hooked portion 40 has a planar upper surface as shown in FIG. 3A , in other embodiments it may angle upward or downward relative to the horizontal direction 34 .
[0018] In some embodiments, the hooked portion 40 may include a slanted, sloped, or contoured lower surface 48 that facilitates guidance of objects into a volume between the two or more tines 12 . In particular, the lower surface 48 may slope upward with distance along the horizontal direction 34 away from the inner surface 42 . The slope may be constant or non-constant, e.g. the slope may increase with distance from the inner surface 42 .
[0019] Referring specifically to FIG. 3B , the tines 12 may advantageously have a planar shape such that the width 50 thereof is much greater than the thickness 52 thereof. In this manner, the tines 12 may fit within the narrow slots 16 of the spreader 14 . For example, the width 50 may be between 4 and 8 times the thickness 52 . In the illustrated embodiment, the width 50 of the tine 12 is substantially constant along the length thereof other than rounding at an upper end and narrowing of the hooked portion 40 due to the sloped lower surface 48 . However, variable width and/or thickness may also be used.
[0020] Referring to FIG. 4A , in preparation for use, the tines 12 may be suspended from the lines 20 in the illustrated configuration. The tines 12 may have a resting orientation in the absence of a load positioned between them. The tines 12 may be symmetrical about a common axis 54 that may also correspond to the common central point of the spreader 14 mentioned above. Accordingly, the other tines may behave in the same manner as the tine 12 illustrated in FIGS. 4A-4C .
[0021] Referring to FIG. 4B , an object 56 may be positioned between the tines 12 by lowering the tines 12 over the object 56 . The sloped lower surface 48 may advantageously guide and urge the lower ends of the tines 12 around the object 56 . Referring to FIG. 4C , upon lifting up on the lines 20 , tension 58 on the lines 20 creates a moment 60 about the pin 18 . Due to the outward force 62 of the spreader 14 , the hooked portion 40 of the tine 12 is constrained to exert an inward force 64 on the object 56 . The combined inward forces of the tines 12 retain the object 56 during subsequent lifting and transportation of the object 56 . The inward force 64 is dependent on the tension 58 , which is dependent on the weight of the object 56 being lifted. Accordingly, the inward force 64 increases with the weight of the object thereby applying an appropriate clamping force. Upon deposition, the tines 12 may be disengaged by lowering the clamping assembly 10 and moving the clamping assembly 10 laterally without lifting such that clamping force does not prevent the object from moving out from among the tines 12 .
[0022] Referring to FIG. 5 , as noted above, the lines 20 and common coupler 22 may be coupled to a shovel 70 of a tracked vehicle 72 . For example, the shovel 70 may be mounted to hydraulic actuators 74 either with or without an intervening arm (not shown) that itself may be articulated and hydraulically actuated. Alternatively, the coupler 22 may be connected to a cable or chain connected to a pulley system, driven spool, or other cable actuating mechanism for raising and lowering the clamping assembly 10 .
[0023] While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Spreader bars and tine sizes may be altered to facilitate various sizes of objects to be moved. Load capacity and strength of chains and swivels may be altered based on considerations relative to the size and weight of the anticipated weight of the objects to be moved/lifted. Likewise, the material used to construct the components may vary according to availability, strength and other considerations. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.
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A clamping assembly is disclosed including a plurality of tines each pivotally coupled to a spreader having first ends above the spreader and second ends below the spreader. The first ends are coupled to lines joined at a common coupler and the second ends include hooked portions. The tines may have a planar shape and fit within radial slots defined by the spreader. The second ends may include slanted lower surfaces that slope upward with distance inward toward a center of the clamping assembly. In use the tines are lowered over an object. Tension applied to the lines causes pivoting of the tines effective to exert a clamping force on the object.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] Priority is based on U.S. Ser. No. 10/758,884 filed Jan. 16, 2004, which is a divisional application of U.S. Ser. No. 09/956,294 filed Sep. 19, 2001 (now U.S. Pat. No. 6,708,902 issued Mar. 23, 2004), which is based on Provisional Application 60/261,613, filed Jan. 12, 2001.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] The field of the invention is dispensers for chemical concentrates, and particularly the dispensing of chemical concentrates at multiple flow rates and different concentrations.
[0004] Dispensers of the type concerned with in this invention are disclosed in U.S. Pat. Nos. 5,320,288 and 5,372,310. While the spraying apparatus disclosed in these patents can control the flow of carrier fluid and chemical product, it cannot do so in a precise and controlled manner.
[0005] U.S. Pat. No. 2,719,704 discloses a valve element 31 with eductor passages 41 and 43 . These interconnect with inlet openings 58 and 61 .
[0006] U.S. Pat. Nos. 2,991,939 and 4,901,923 disclose eductor type dispensers having rotatable discs with various sized apertures for controlling the amount of concentrate being drawn into the water flowing through a nozzle.
[0007] A dispenser which dispenses chemical concentrate should have the capability of dispensing the concentration at a low rate such as in the instance where a bottle is to be filled and at a high rate where a bucket is to be filled. In the instance of a bucket fill, it is desirable if both a low and high concentration of chemical concentrate can be provided.
[0008] The prior art provides either a rotatable with concentrate flow passages, eductor type dispensers having rotatable discs with various sized apertures, or a sliding open-venturi. It does not provide a dispensing apparatus with both sliding and rotating eductors as well as valving so as to afford different concentrations of chemical concentrate at different flow rates.
SUMMARY OF THE INVENTION
[0009] The present invention provides a dispenser for dispensing different concentrations of chemical concentrate into a stream of water from a concentrate container at different flow rates. The dispenser includes a body member having a through bore with an inlet end adapted to be connected to a source of pressurized water at one end and an outlet at the opposite end connected to the inlet housing. A valve member is slideably positioned in the through bore of the body member. An eductor is slideably and rotatably received in the body member. The eductor is in contact with the valve member and in fluid communication with a source of chemical concentrate. A trigger member is connected to the body member and eductor to cause slideable movement of the eductor. The eductor and valve member are constructed and arranged to provide control of both different concentrations of chemical concentrate and different flow rates of water and chemical concentrate.
[0010] In a preferred embodiment, the eductor is composed of first and second parts with only the first part being rotatable and extending from the body member.
[0011] In another embodiment, a second part of the eductor is nonrotatable and includes a fluid passage. A dilution adjustment member having a multiplicity of different sized apertures is connected to the rotatable eductor for sealable engagement with the fluid passage.
[0012] In one aspect, the body member includes a product passage and a vent passage. A seal is constructed and arranged to seal both the product passage and the vent passage.
[0013] In another preferred embodiment, the valve member in the dispenser includes first and second valve members operatively associated with the nonrotatable eductor, the valve members constructed and arranged so that when the first valve member is moved in a linear slideable manner with respect to the second valve member, a first flow rate is effected and when the second valve member is moved in a linear slideable manner with respect to the body portion with the first valve member moved linearly with respect to the second valve member, a second faster flow rate is established.
[0014] In another aspect, the dispenser includes an elongated spout connected to the body member and a flexible tube member connected to the eductor and the spout.
[0015] In yet another aspect, the trigger member includes a latching mechanism.
[0016] In still another aspect, the body of the dispenser includes a finger engaging portion extending therefrom at the inlet and a trigger member pivotally connected to the body and extending over a portion of the body opposite the finger engaging portion.
[0017] In yet another preferred embodiment, there are indexing members operatively associated with the body member and the eductor.
[0018] A general object of the invention is to provide a dispensing apparatus which can effect a mixing of chemical concentrate into a stream of water at different concentrations and dispense the mixed concentrate at controlled flow rates.
[0019] Another object is a closed dispenser which produces low foam, low air entrapment and a low energy liquid fill independent of the pressure of the attached water supply.
[0020] Other general objectives are a dispensing apparatus which can both spray and/or fill, gives control over both flow and dilution and lends itself to be integrated with a bottle so they cannot be separated.
[0021] Still another object is a dispenser which is composed of plastic parts, thus economical to produce and is disposable.
[0022] Yet another object is a dispenser of the foregoing type which has a good hand feel.
[0023] Still yet another object is a dispenser of the foregoing type which can accurately dispense chemical concentrate.
[0024] Yet another object is a dispenser of the foregoing type which can accommodate a back flow prevention device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a perspective view of the dispenser of this invention in conjunction with a container.
[0026] FIG. 2 is a view in side elevation of the dispenser shown in FIG. 1 .
[0027] FIG. 3 is an exploded view of the component parts of the dispenser.
[0028] FIG. 4 is a cross sectional view of the dispenser in a closed position.
[0029] FIG. 5 is a view similar to FIG. 4 showing the dispenser in a low flow condition.
[0030] FIG. 6 is a view similar to FIG. 4 showing the dispenser in a high flow condition.
[0031] FIG. 7 is a cross sectional view illustrating an indexing of an eductor in the dispenser.
[0032] FIG. 8 is a fragmentary view of the dispenser housing illustrating the eductor contact surfaces for limiting the movement thereof.
[0033] FIG. 9 is a cross sectional view of the dilution adjustment member utilized in the dispenser.
[0034] FIG. 10 is a perspective view of an alternative dilution adjustment member in the dispenser.
[0035] FIG. 11 is a perspective view of the housing of the dilution adjustment member shown in FIG. 10 .
[0036] FIG. 12 is a perspective view of a dilution adjustment device for use in the dilution adjustment member.
[0037] FIG. 13 is a back view of the dilution adjustment device shown in FIG. 12 .
[0038] FIG. 14 is a front view of the dilution adjustment device shown in FIG. 12 .
[0039] FIG. 15 is a cross sectional view of a component of a flow control device employed in the dispenser.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Referring to FIGS. 1 and 2 , the dispenser generally 10 has a body member 12 with a container connector 14 for connection to a container or bottle 16 . A preferred connector system is more fully described in commonly owned U.S. Pat. No. 6,772,914 issued Aug. 10, 2004, which teachings are incorporated herein. At one end of the body member 12 is a hose attachment 18 for supplying pressurized water to the dispenser. A handle 17 is provided below attachment 18 . At the other end there is the spout 22 and a nozzle 20 for dispensing a mixed chemical solution. A flexible tube 15 extends between nozzle 20 and spout 22 .
[0041] Referring to FIGS. 3 and 4 , the dispenser 10 includes an eductor generally 11 composed of the first or outer eductor part 24 with a diverging passage 24 a and an inner second eductor part 26 with a converging passage 26 a. They are slideably connected in body member 12 with seals 52 and 56 providing a fluid tight contact. A valve assembly 28 for controlling the flow of water through the dispenser 10 is also slideably housed in body member 12 and is in contact with eductor part 26 . The hose attachment 18 is rotatably connected to body member 12 by the snap fitment 34 . A back flow preventer 30 is positioned in hose attachment 18 and has a seal 32 for contact with body member 12 . At the opposite end of body member 12 , the nozzle 20 is attached to eductor part 24 .
[0042] An annular groove 36 is provided in the eductor part 24 and accommodates a head portion 38 of the trigger 40 with flange portions such as shown at 42 on the trigger 40 having shafts (not shown) for extending into bores such as 44 . A latch member 46 extends upwardly from the member 12 for fitment through the passage 48 of the trigger 40 .
[0043] A dilution adjustment member 50 is connected to the eductor part 24 by means of the splines 47 . This is shown in FIG. 9 . It has L-shaped passages 90 - 94 for introducing chemical concentrate into the gap 27 between eductor parts 24 and 26 . These passages 90 - 94 have different diameters or widths for metering different concentrations of chemical concentrate. In some instances there are no passages to provide a rinse function. A dip tube 19 is connected to body member 12 and extends into container 16 for siphoning chemical concentrate into the bore 13 of body member 12 by way of passage 21 . A seal member 23 is placed between dilution adjustment member 50 and body member 12 . A vent passage 25 connects container 16 and bore 13 . The adjustment member 50 is positioned inside eductor 26 . A spring 54 biases eductor part 26 as well as eductor part 24 toward the head portion 38 of trigger 40 .
[0044] A quad O-ring 60 is attached in groove 57 of valve head portion 58 . It serves as a flow control element as later explained. A valve member 28 with passages 33 has a head portion 58 with groove 59 . A seal 66 is seated in groove 59 of head portion 58 and another seal 64 is placed on collar 62 . A gasket 67 is provided for cap 68 and a hose seal is provided at 69 .
[0045] Referring to FIG. 8 , it is seen that body member 12 has a surface 79 for contact with contact member 29 of eductor 24 as well as a grooves 81 and 82 for the purpose of linearly positioning the eductors 24 and 26 and accordingly valve assembly when trigger 40 is depressed. A keyway 70 is disposed in body member 12 for accommodating a key member 76 (See FIG. 9 ) in eductor part 26 for allowing sliding but nonrotatable connection in body member 12 . A second opposing keyway 80 is also disposed in body member 12 in conjunction with key member 84 .
[0046] Referring to FIG. 7 , there is shown the eductor 24 with notches 77 . These accommodate the projections 75 on arms 72 and 73 extending from body member 12 . This provides an indexing function in conjunction with the orientation of dilution adjustment member 50 and passage 21 .
[0047] FIGS. 10-14 illustrate an alternative embodiment of the dilution adjustment member 50 which is formed as a separate component from the eductor 24 . In the embodiment, generally 101 shown in these FIGURES, the dilution adjustment member includes a dilution adjustment housing 102 into which is fitted a dilution adjustment device 112 . Housing 102 includes a central passageway 110 for flow of water and chemical concentrate. It also has five L-shaped passages 103 with an oval portion 105 in a side wall 104 and a cylindrical portion 107 in an end wall 106 . The annular adjustment device 112 frictionally fits inside annular housing 102 and also has a central passageway 111 for water and chemical concentrate. As best seen in FIG. 13 , adjustment device or adapter 112 has an annular body 113 through which extend the passages 114 from a front side 115 to a back side 117 . These passages also extend through tubular members 116 at the back side 117 . These tubular members 116 fit into the cylindrical portions 107 of passages 103 in dilution adjustment housing 102 . Passages 114 have constrictive bores 122 which are of various dimensions. Alternatively one or more of them could be blocked to provide a rinse function. An orientation projection 118 extends from back side 117 for fitment into orientation compartment 109 of adjustment housing 102 . This facilitates orientation of the tubular members 116 into portions 107 . Projections 120 extend from front side 115 for contact with eductor 26 to provide the gap 27 between the eductors.
OPERATION
[0048] A better understanding of the dispenser will be had by a description of its operation. Referring to FIG. 4 , the dispenser is shown in a closed position. A source of pressurized water such as a hose will have been connected to hose attachment 18 . In this instance, seal 66 on valve head 58 is seated against collar 62 and seal 64 against valve seat portion 65 . Accordingly, no water can pass between these two components and into bore 13 . This sealing effect is assisted by the flow of water in through the attachment 18 , against the valve components 58 and 62 . The spring 54 and force of water also positions the head 31 of eductor part 24 away from body contact surface 79 .
[0049] Referring now to FIG. 5 , trigger 40 has been moved toward body member 12 with the result that eductor head 31 is contacting surface 79 of body member 12 . Valve portion 58 has moved toward the attachment 18 and seal 66 no longer engages collar 62 . In this position, water can flow between the two component parts as there are grooves 63 placed in the collar 62 to allow such flow into bore 13 . This is a low flow condition. In this position, the quad O-ring 60 serves as a flow control element, in that, with increased pressure and flow of water, the ring will expand and partially fill the grooves 63 . This maintains a consistent flow rate despite variations in the pressure of the inlet water supply. Water can then pass through passages 33 and into passage 26 a of eductor part 26 .
[0050] In order to initiate a high flow condition, the trigger 40 is moved further toward body member 12 . This is shown in FIG. 6 . In this position, not only has seal 66 moved away from collar 62 but collar 62 also has moved away from valve seat portion 65 . In this position, water cannot only flow from between head portion 58 and the grooves 63 in the collar 62 , but also between the collar 62 and the valve seat portion 65 . It should be pointed out that in this high flow position, trigger 40 can now become engaged with latch 46 if desired so that it can be held in the high flow condition. Referring again to FIG. 8 , the contact member 29 of eductor part 24 will now engage the grooves such as 81 or 82 so as to allow the eductor parts 26 and 24 to be moved further inwardly into the body 12 .
[0051] During the previously described flow conditions through the dispenser 10 such as when in the high or low flow condition, the concentrate will be drawn upwardly from the container 16 such as through the dip tube 19 . However, as noted previously in FIG. 4 , there is a seal member 23 positioned over the passage 21 so that no product can be drawn up from the container 16 . At the same time, seal 23 also closes vent passage 25 . As seen in both FIGS. 5 and 6 , the seal member 23 has moved away from both the product and vent passages 21 and 25 , respectively. In this position, drawn product is allowed to enter into one of the five passages 90 , 91 , 92 , 93 and 94 of dilution adjustment member 50 as seen in FIG. 10 . Concentrate is thereby siphoned into gap 27 and mixed with water flowing through passage 26 a and 24 a. A reduced pressure is caused by the water converging in passage 26 a and diverging in passage 24 a.
[0052] The orientation of the various passages 90 - 94 with the opening 23 a in seal 23 is facilitated by the indexing shown in FIG. 7 .
[0053] The mixed solution will then exit through nozzle 20 down through the tube 15 positioned in the spout 22 . Tube 15 in this instance is flexible so as to allow the eductor 24 to move inwardly and outwardly from the body member 12 . With product passing through tube 15 and spout 22 , this is the position which is utilized when filling a bucket or a bottle. As previously described a low flow condition would be utilized for filling a bottle while the high flow condition would be utilized to fill a large vessel such as a bucket. The spout 22 provides for the dispenser to be hung on a bucket 22 a. If desired, a hose (not shown) can be connected to spout 22 for filling purposes such as a โscrubber washerโ or when the dispenser is mounted to a wall. Dispenser 10 can easily be converted to a spray unit by the replacement of the nozzle 20 and the attachment of a conventional spray head (not shown). Also stated previously, the concentration of the solution can be easily adjusted by the rotation of the eductor 24 in conjunction with the dilution adjustment member 50 . The low and high flow condition in combination with the dilution adjustment member obviates the use of multiple dispenser heads.
[0054] It will thus be seen that there is now provided a very versatile dispenser which can be utilized in not only a high and a low flow condition but also can be adjusted to vary the concentration of mixed solution. The dispenser 10 is produced economically so that once it is captively connected to a container, it is disposable.
[0055] It will also be seen that a good hand feel is provided by dispenser 10 . This is accomplished by placement of the handle 17 beneath body member 12 and outwardly from trigger 40 to allow placement of a thumb on trigger 40 .
[0056] Dilution adjustment member 101 will function in the same manner as dilution adjustment member 50 . The advantage it has is that the formation of the passages 114 in dilution adjustment device 112 can be more easily controlled as a separate piece during plastic molding. Further, it is less expensive to supply several dilution adjustment devices 112 with varying dimensions of the passages 114 for fitment into housing 102 . To facilitate identification they can be of different colors.
[0057] The dispenser 10 has been preferably described in conjunction with a latching feature for the trigger 40 . It is obvious that this is not an essential feature that can be eliminated. Neither is it essential that a back flow preventer be employed in the unit itself. This could be accomplished upstream in a supply line. Further, while the spout 22 offers the advantage of a hose attachment such as with the barbs 100 , this could be eliminated although it does further offer the advantage of a bucket attachment. Neither is it essential that the container connector 14 provides a captive use of the dispenser with the container. The dispenser 10 could be utilized with a refillable container. While dilution adjustment members 50 and 101 have been shown to have five passages, the number can vary from a single passage to as many as can be practically manufactured. In some instances, it may be desirable to limit the dispenser for flow through a single passageway. This could be accomplished by placement of a pin through body member 12 and a groove in eductor part 24 . All such and other modifications within the spirit of the invention are meant to be within a scope as defined by the appended claims.
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A dispenser for mixing and dispensing a liquid chemical concentrate with a dilutent from a container. The dispenser includes two slideable eductors one of which is also rotatable. Both a high and low flow rate can be obtained with simultaneous adjustment of concentration of the chemical concentrate. The dispenser has a high degree of accuracy of the amount of dilution of the chemical concentrate as well as positive positioning of the high and low flow rate.
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TECHNICAL FIELD
[0001] The present invention relates to a method and system for monitoring the condition of livestock. In particular, it relates to remotely monitoring the behavioural and physiological states of livestock to determine their welfare, health and fertility condition.
BACKGROUND OF THE INVENTION
[0002] With increasing awareness of health related issues concerning livestock and the significant losses that arise from poor fertility management, the farming industry has been forced to adapt in maintaining accurate records of livestock. As the size of farms increase, the ability of a stockman to keep records and track individual animals becomes increasingly difficult. There are many known systems for electronically tagging animals for identification purposes etc. Identification data is held in a unit worn by the animal in a neck collar, ear tag or injected transponder or the like. The data can be extracted as required at fixed or mobile locations.
[0003] It is also known to utilise such tags to collect data relating to activities of the animal, for example U.S. Pat. No. 5,857,434. U.S. Pat. No. 5,857,434 discloses detection of oestrus in dairy cattle. A transponder unit worn in a collar around the animal's neck detects the movement of the animal. During oestrus, the animal becomes agitated and moves around more frequently. This increased activity is detected and transmitted, along with identification data for the animal, to a central processor. The data is then processed and analysed to establish whether oestrus is detected and this is indicated to the stockman. The transponder merely collects the movement data of the animal. This data is then transmitted and centrally processed. The transponder does not detect oestrus. Further only a single condition, oestrus, is monitored and the system does not provide data concerning other health related matters.
[0004] Further some existing systems require sensors to be attached invasively which is distressing to the animal and requires the skill of a veterinary surgeon. Further such forms of attachment to the animal have limited ability to transmit information from the animal for use by the stockman.
[0005] Further existing systems, such as that disclosed by GB 2347503 and CA 1296068 , comprise a range of sensors for monitoring the physiological parameters of an animal for determining the health of the animal. However, these require complex and, invariably, temperamental sensory instruments in order to monitor the physiological parameters making the system overall very expensive and hence impractical for monitoring all animals in a very large herd or group in a farming environment.
[0006] Furthermore due to the complexity of these systems, they require professional assistance, such as a veterinary surgeon, to set up, program and maintain the system which is impractical for an extremely large number of animals. Further, as such systems monitor physiological parameters, it is less intuitive to the stockman, who traditionally relies on observation to monitor health, to confirm the condition indicated by the system, thus making it more difficult for the stockman to verify the accuracy of the system.
[0007] Further, In monitoring the condition of livestock, a key period for health monitoring in cattle, sheep, horses and pigs is in the period immediately before and after parturition. None of the existing systems disclose specific monitoring during such periods.
[0008] At present there is no system that can do any of the condition based monitoring of cattle necessary to improve both the health and fertility monitoring of animals. Monitoring is still by human visual observation as it has been since the first domestication of animals. However, it has become increasingly desirable for better management of livestock, in particular health monitoring in livestock in the period immediately before and after parturition and to reduce losses from dystocia, hypocalcaemia and other diseases.
[0009] It has also become increasingly desirable to reduce time lost moving animals unnecessarily for veterinary examination. Further, it is desirable to provide earlier intervention in cases of metritis and lameness and thus improve welfare and possibly productivity of animals such as dairy cattle as well as provide improved oestrus detection.
[0010] With the increasing scale of farming, it has become increasingly difficult and impractical for stockmen to rely on traditional observation techniques to ensure health and welfare of their stock. There has therefore been an increasing need for additional monitoring systems to be utilised.
SUMMARY OF THE INVENTION
[0011] The invention seeks to provide remote, continuous monitoring of various parameters relating to the condition of livestock, such as cattle, sheep, pigs, horses and the like which mitigates the above mentioned disadvantages.
[0012] This is achieved according to an aspect of the present invention by a method for monitoring the condition of livestock, the method comprising the steps of: sensing a plurality of different behavioural parameters of a subject; transmitting the sensed behavioural data, wirelessly, to a central processor; and determining a plurality of status conditions of the subject on the basis of the transmitted, sensed behavioural data.
[0013] This is also achieved according to an aspect of the present invention by a system for monitoring the condition of livestock, the system comprising: a plurality of sensors for sensing a plurality of different behavioural parameters of a subject; at least one transmitter for transmitting the sensed behavioural data, wirelessly, to a central processor; a central processor for receiving the transmitted, sensed, behavioural data and determining a plurality of status conditions of the subject on the basis of the transmitted, sensed, behavioural data.
[0014] In this respect, behavioural parameters are those parameters relating to the behaviour of a subject. In particular it relates to parameters concerning the action and response of a subject to stimulation or its environment.
[0015] Further, this is achieved according to another aspect of the present invention by a device for monitoring the condition of livestock, the device comprising means for attaching the device to a subject; a plurality of sensors for sensing a plurality of different behavioural parameters of a subject; a transceiver for transmitting the sensed, behavioural data, wirelessly, to a central processor for determining a plurality of status conditions of the subject on the basis of the transmitted, sensed, behavioural data.
[0016] The monitor worn by the subject (animal) collates and processes the data in respect of the detected parameters of the livestock. The monitor transmits the data; say for example, via a local area network to a processor, which may in turn be linked via wireless communication to a central data processor and storage device. The data may be contained in a local database for use by the stockman and may also be contained in a national or veterinary health information database for wider reference and analysis. On the basis of the detected parameters, a plurality of status conditions, such as for example, oestrus, onset of parturition, lameness, disease, can be derived as an indication of the overall condition of the animal. Since behavioural parameters are monitored, the system is less complex and the monitored behaviour can be easily confirmed by stockman observations, making use of the system more intuitive, thus increasing the stockman's confidence in the system.
[0017] In an embodiment of the present invention, the system comprises a network of sensors attached to the animal. The sensors may be included in a neck collar, head collar, eartag, tail attachment or patches adhered to the skin of the animal or any combination thereof. The sensors are therefore fitted in a non-invasive manner. The sensors may be connected in a bus-like architecture to allow easy addition and removal of sensors as required. Further, the sensors may be reusable.
[0018] The sensors may measure location, movement, sound and optical change. The monitor worn by the animal may also include a processor to collect and process information and control communication, software embedded on the processor, a transceiver and a memory store for recording sensor data.
[0019] The monitor worn by the animal communicates with an external antenna. The external antenna may comprise a distributed network of antennae provided at different locations. The antennae may download data wirelessly to a local computer system containing a stock management database to be analysed and provide output of prediction and current behaviour/condition of the animals. The analysis is based upon physiological models which can be updated remotely.
[0020] The system of the present invention therefore provides effective livestock management and veterinary assistance to predict and react to the onset of conditions such as fertility status, parturition and to detect, at an early stage, lameness of the animals.
[0021] The system may be easily extended to predict the onset of disease and predict its epidemiological spread by its links to national or other level databases.
[0022] The system may be supplied with various methods of supplying the livestock manager with predictions of conditions; these could include mobile telephone messages, computer screens and milking parlour displays.
[0023] The data may be downloaded from the monitor units worn by the animal to the distributed network of external antennae utilising radio protocols such as Bluetooth or Zigbee. Preferably the antennae are placed near congregation points for the livestock, such as feed area, watering troughs, etc. The data may be transferred to a local processor where data analysis is carried out providing information to the stockman and/or uploading a data summary to a regional or national database, where the data is correlated.
[0024] The system of the present invention can be utilised to detect the onset of parturition, illness such as lameness and fertility status. The aim is that a network of physical sensors is used to determine behavioural and physiological indicators of condition status and an indication of time of onset of a subsequent condition. Various parameters of the animal are recorded electronically by the monitor unit worn by the animal that can be communicated with any suitably equipped vehicle, market reception, and abbatoir to monitor the health and welfare of an animal as it moves through the food chain. The attachment of the monitor unit is designed to be robust so that it can be worn for long continuous periods as necessary, for example, for the life of the animal. The monitor unit may record a health status record of the animal. This record stored within the monitor unit is then permanently attached to the animal, that is, it is worn for the life of the animal. The data stored may include, for example, birth data, birth location, subsequent lactations, date of parturition, past or predicted health incidents etc.
[0025] The monitor unit may be a โsmartโ unit incorporating multiple sensors, a versatile communications infrastructure and multiple behavioural models. The unit of the present invention may incorporate multi-modal sensors incorporating behavioural and physiological analysis to monitor specific conditions in livestock allowing multiple conditions to be monitored simultaneously.
[0026] Further, this is achieved according to yet another aspect of the present invention by a device for maintaining an electronic record of condition of livestock, the device comprising: storage means for storing a plurality of records of condition of a subject; means for permanently attaching the device to said subject. Further, some or all of the monitor electronic record may be stored using external storage means e.g. a farm or national database and may be permanently associated with the local monitor electronic record.
[0027] In this way various conditions of the animal are recorded electronically by the monitor unit worn by the animal that can be communicated with any suitably equipped vehicle, market reception, and abbatoir to monitor the health and welfare of an animal as it moves through the food chain. The monitor unit is worn permanently by the animal in that it is attached for the life of the animal. The monitor unit may record a health status record of the animal. This record stored within the monitor unit is then permanently attached to the animal. The data stored may include, for example, birth data, birth location, subsequent lactations, date of parturition, past or predicted health incidents etc.
[0028] The monitor unit may also receive data from the central processor such as status condition data derived from the sensed data, any environmental data, manually entered status condition data such as actual parturition dates and other observed health issues noted by the stockman, programming data to reprogram the monitor unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] For a complete understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings, wherein:
[0030] FIG. 1 is a schematic diagram of the system according to an embodiment of the present invention;
[0031] FIG. 2 is a schematic block diagram of the device worn by the animal according to an embodiment of the present invention;
[0032] FIG. 3 is a flow chart of the method according to an embodiment of the present invention;
[0033] FIG. 4 is a flow chart of the sensory step of the method according to an embodiment of the present invention; and
[0034] FIGS. 5 a , 5 b and 5 c are a graphical representation of an example of a condition monitored according to the embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] With reference to FIGS. 1 and 2 , the system according to an embodiment of the present invention comprises a collar 101 fitted around the neck of an animal. A monitor unit 115 is attached to the neck collar 101 . Although, in this embodiment the unit 115 is fitted to a neck collar, it can be appreciated that the unit can be fitted to any convenient fixture device such as for example an ear tag 103 , head collar 105 , leg attachment 107 or belt (not shown here), transdermal patches 109 , 111 , ingested bolus 113 or any one of these in addition or in place of the collar 101 . The unit 115 is intended to be attached to the animal for continuous monitoring. The attachment needs to be robust to remain attached to the animal for a continuous period, which may in some circumstances be the life of the animal. Although the collar is shown fitted around the neck of a cow, it can be appreciated that the apparatus can be attached to any animal such as for example dairy cow, beef cow, buffalo, sheep, goat, pig, horse and the like.
[0036] The collar 101 is fitted to make a snug fit so that it is not slideably moveable along the neck of the animal as the animal head moves up and down extensively such as when the animal is feeding or drinking. The fitting of the collar 101 must be secure to prevent accidental loss during normal activities of the animal such as rubbing against a post and knocking against the bars of a grill on a feeding trough etc. The fixture of the collar 101 may be by means of a buckle, sliding clip etc. The fixture may include a self-tensioning device to maintain a predetermined tension to ensure accurate fitting of the collar.
[0037] The unit 115 may be mounted onto the collar 101 or may be formed integral with the collar 101 . The collar 101 further comprises an antenna (not shown here) which may be contained in the unit 115 or within the collar 101 . The unit 115 comprises a plurality of sensors 201 , 203 , 205 for monitoring behavioural parameters at least and also sensors for monitoring physiological parameters as shown, for example, in FIG. 2 .
[0038] FIG. 2 illustrates 3 sensors, a 3-D accelerometer 201 , a locator (such as GPS) 203 and a microphone 205 . However, any number of sensors may be envisaged such as electromagnetic or field effect sensors, e.g. Hall effect sensors or distance from ground sensors
[0039] The apparatus may further comprise means for monitoring the distance of the collar above ground. This may be in combination with a sensor to indicate the normal position of the animal's neck with respect to its body. The distance to ground of the collar can provide an indication of whether the animal is standing or lying. This may comprise a range sensor attached to the collar on the underside of the animal's neck, pointing at an angle that, for the median range of what is considered normal neck repose, assumes a vertical or near vertical orientation and therefore provides a vertical range from the sensor location to ground level.
[0040] Sensing of the neck orientation may be achieved using inclinometers, tilt or magnetometer sensors providing geometric information, any fixed distance measuring device mounted on the collar on the underside of the animal's neck, can be easily verified against a range of acceptable orientations to supply a valid distance of the neck above ground. Inexpensive distance measuring sensors can be used, such as for example an ultrasonic distance measuring sensor which can provide tolerable accuracies when measuring from fixed reference points projecting to varying ground textures such as grass, straw bedding, concrete flooring etc.
[0041] The ability to discriminate standing and lying conditions of an animal can be invaluable in determining a status condition of the animal. For example, during parturition, it is important to know that the animal stands quickly postpartum. This indicates that the mother is able to foster and cleanse its offspring.
[0042] The apparatus may further include a plurality of remote sensors 207 positioned elsewhere on the animal outside of the housing of the unit 115 such as sensors for measuring body temperature, humidity, pH of biological fluids, electrical potentials from physiological processes, Hall effects, optical sensors of blood flow or blood oxygenation, vocalisation and respiration, breath and saliva contents, environment temperature and humidity. These remote sensors may be found in an ingested bolus 113 , or patches 109 , 111 . Additional remote sensors may be included in the eartags 103 , head collar 105 and/or leg attachment 107 . In an alternative arrangement, the unit 115 may be mounted in the eartag 103 , head collar 105 or leg attachment 107 etc.
[0043] The unit 115 further comprises a local processor 209 which is connected to the sensors 201 , 203 , 205 via, respective, analogue to digital converters 211 _ 1 , 211 _ 2 and 211 _ 3 . The plurality of remote sensors 207 is connected to the processor 209 via a wireless link such as short wave radio. The outputs of the remote sensors 207 are digitised via respective analogue to digital converters (not shown here). The unit 115 may further comprise pre-processing means (not shown here) for processing the outputs of the sensors prior to transmission, for example, filtering.
[0044] Each remote sensor 207 has a unique identifier associated with a particular animal to prevent remote sensors attached to a neighbouring beast being received and processed by the local processor.
[0045] The unit 115 further comprises a local memory store 213 , a power source 215 and a transceiver device 217 connected to the processor 209 . The power source 215 may comprise replaceable or rechargeable batteries. The unit 115 includes convenient access to a battery housing for replacement etc. of the batteries of the power source 215 .
[0046] The sensors 201 , 203 , 205 and 207 are connected via a bus architecture so that additional sensors can be added or removed as required. Preferably the sensors are reusable so that they can be reprogrammed and fitted to another animal etc.
[0047] The system further comprises at least one fixed antenna 117 . The antenna 117 is provided in a location on the farm where the animal is expected to be in the vicinity of at least once a day so that data collected by the unit 115 can be downloaded. The antenna 117 may be located at the entrance or exit of a milking parlour or at a drinking or feeding trough for example. The antenna may form part of a distributed network of antennae located at various locations such as drinking troughs, sheds, milking parlour etc. The data downloads may be required at more or less frequent intervals. For example, if the output sensory data indicates that the animal is in distress, the system can request via the antenna 117 more frequent downloads. Further, as the predicted parturition date approaches, downloads could be made more frequently, at say, 3 hour intervals. This is possible as many animals are housed in pens as parturition approaches and could therefore be housed in the vicinity of at least one antenna for convenient, frequent downloads.
[0048] The system further comprises a local computer (PC) 119 having a display and printer connected thereto. The local computer 119 is remotely connected to a national database 121 via, say, the internet. The local computer 119 may also provide output to a hand-held electronic device 123 such as a mobile telephone or palmtop. The local computer 119 provides 2-way communication with the antenna 117 such that a unit 115 can be reprogrammed or reset by the stockman or reprogrammed automatically to request more frequent downloads for example. Further the two-way communication between the computer 119 , antenna 117 and unit 115 allows other data to be transferred to the unit 115 .
[0049] With reference to FIGS. 3 and 4 , operation of the apparatus will be described in more detail.
[0050] The sensors 201 , 203 205 , 207 continuously monitor a variety of behavioural (and physiological) parameters of the animal. The digitised output of the sensors 201 , 203 , 205 and 207 are collated by the processor 209 and are stored in the local memory 213 . At predetermined time interval or upon detected of the unit 115 in the vicinity of an antenna 105 , the collated data for that time interval is transmitted by the transceiver 217 to the antenna 117 . This data is then transferred to the local, farm computer 119 . The farm computer 119 stores records for each animal by virtue of the animal's unique identifier which may be stored in its eartag 103 . This identifier may be virtually linked to the animal's unique electronic legislative Identity. As data is downloaded from the antenna 117 on, say, a daily basis. The farm records can be updated automatically providing the stockman with an updated status of each animal. The updated status of the animal may also be communicated for storage in the local store 213 of the unit 115 such that this data can be downloaded from the unit 115 in the event that the animal leaves the farm. The data stored in the farm computer 119 and/or local store 213 of the unit 115 may include the animal's unique identifier, current condition, for example maiden, pregnant, lactation, number of lactations, days in milk, lame, predicted parturition date, predicted next oestrus (fertility status), suspected illness, of last update where the data is analysed.
[0051] The various sensor outputs indicating the behavioural status 301 of the animal is received by the computer system 119 via the antenna 117 . This data is compared to a reference physiological data model of the sensory outputs and the behavioural status 301 . The 3-D accelerometer 201 records the spatial orientation and movement of the animal's head. This data is analysed by the farm computer 119 to indicate behavioural patterns such as time spent lying, standing, walking 401 and time spent feeding or drinking 403 . The microphone 205 records noises made by the animal which can be analysed to indicate time spent eating, ruminating (in the case of a ruminant) and vocalisation 403 and in addition respiration rate and heart rate. The locator 205 provides the location of the animal 405 . The relative location 407 may also be monitored. The location data can be analysed to indicate whether the animal is with the herd or keeping up with the herd which may indicate health problems. These are examples only and a number of additional sensory inputs may be analysed to provide additional inputs to the behavioural status 301 of the animal. For example, the additional remote sensors 207 may include monitoring the change of state of a muscle or muscle group or the degree of contraction of a muscle, e.g. Electrohysterogram (EHG), foetal heart rate, body temperature and blood oxygenation.
[0052] In a particular example, the output of the accelerometer 201 indicates movement of the animal's head and In combination with the output of the locator 203 indicate when the animal's head is down feeding or drinking. Erratic eating or drinking patterns could indicate that the animal is ill and/or distressed. If the head movement is vigorous during feeding, this would indicate that the animal is healthy. Thresholds of the frequencies of head movement can be set whilst taking into consideration the food type and texture and the age of the animal such that frequency of head movement above the threshold indicates the animal is healthy and below the threshold indicates the animal is ill.
[0053] The output date of the sensors 201 , 203 , 205 can also be used to predict fertility status such as oestrus. It is observed that many animals change their behavioural pattern at this time. They generally become more active, fidget and more agitated. The accelerometer and locator indicate increased walking activity in the animal. Its relative location to the other animals may also provide an indication of fertility status.
[0054] The behavioural status 301 of the animal can also be utilised to indicate the general health 303 , such for example prediction of the onset of parturition and subsequent lactation, the foetal heart rate indicating health of the unborn, the detection of deviations from a pattern indicating wellness, detection of hypocalcaemia, detection of dystocia, parturition, metritis, lameness, acidosis and ketosis and fertility status 305 such as oestrus. Additional input via the farm computer 119 may be provided by manual input 307 by the stockman and/or milk sensors 309 monitoring milk production etc. Other inputs may be considered such as environment sensed data such as temperature and humidity, weather conditions provided from other sources. The output of the health status 303 , fertility status 305 is provided to the stockman via a display or printer for action 311 such as insemination, inspection etc. In this way the system provides an effective way of informing the stockman of various condition status of each animal so that the stockman has better knowledge of the condition of his livestock to enable him to manage feeding, location, bedding, mineral offerings, drug requirements. The predictions provided by the system also enable the stockman to manage more easily farm resources etc. The system may provide an alarm system to indicate an urgent condition status such as difficulties in parturition or indication of serious illnesses such as hypocalcaemia and hypomagnesaemia which require immediate attention.
[0055] As illustrated in FIG. 5 , an example of a condition monitored by the embodiment of the present invention is illustrated, lameness. Lameness, in particular in dairy cattle, is problematic and therefore it is highly desirable to monitor such a condition in dairy cattle.
[0056] As illustrated in FIG. 5 a , the normal gait of an animal is represented generally as a smooth, rhythmic head movement which is detected by the accelerometer sensor 201 . However, in a lame animal the movement is more erratic with jerky movements as illustrated in FIG. 5 b . This output is analysed by the farm computer, for example by counting novel singularities or measuring the change of slope or integrating area under an RMS or by FFT of the frequency data to detect anomalies as illustrated in FIG. 5 c . Numerous mathematical techniques are available and can be overlaid to extract features from the data.
[0057] Although a preferred embodiment of the method and system has been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiment disclosed, but is capable of numerous variations, modifications without departing from the scope of the invention as set out in the following claims.
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A method and system for monitoring the condition of livestock comprises a plurality of sensors ( 115, 103, 113, 111, 107, 105 ) for sensing a plurality of different behavioural parameters of an animal. The sensed data is transmitted by a unit ( 115 ), wirelessly, t a central processor ( 119 ) and a plurality of status conditions of the animal is determined on the basis of the transmitted, sensed data such as the onset of parturition, fertility status and other health status conditions. The unit ( 115 ) may be permanently worn by the animal and may keep an electronic record of the status conditions of the animal.
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TECHNICAL FIELD
The present invention relates generally to seats for vehicles and, more particularly, to a seat track protector assembly for a vehicle.
BACKGROUND OF THE INVENTION
It is known to provide a seat for a vehicle such as a sport utility vehicle or a pick-up truck. Typically, the seat includes a generally horizontal seat portion and a generally vertical back portion operatively connected to the seat portion. The seat may include at least one, preferably a pair of tracks to allow longitudinal adjustment of the seat portion. The tracks are spaced laterally and extend longitudinally and are secured to vehicle structure such as a seat riser by suitable means such as fasteners. The tracks are steel, rolled sections with a fixed lower track member and a sliding upper track member. The tracks may be manually adjusted longitudinally or by power. When the seat is adjusted rearward, the upper track member moves into a rear passenger occupant foot space where it can be contacted by a foot of an,occupant.
SUMMARY OF THE INVENTION
The present invention is a seat track protector assembly for a vehicle. The seat track protector assembly includes a cover for a rear of a seat track, which matches a shape of an upper track member and moves with the upper track member until it is disposed on a lower: track member for the seat track as the upper track member moves forward of the lower track member. In addition, the seat track protector assembly includes a spring cooperating with the cover and is attached to the fixed lower track. As the upper track member moves rearward, the cover is engaged and moved rearward, thereby providing protection in any seat position.
The seat track protector assembly of the present invention is disposed over a track member of the seat, substantially: reducing risk of sharp foot contact with the track member by an occupant. The seat track protector assembly also improves the appearance of the seat track. The assembly is self-contained to fit to an existing seat track using simple fasteners from under the seat track. Therefore, it provides an easy retrofit while offering a durable, tamper-resistant character.
Other objects and features of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a seat track protector assembly, according to the present invention, illustrated in operational relationship with a seat of a vehicle.
FIG. 2 is an enlarged perspective view of the seat track protect assembly of FIG. 1 .
FIG. 3 is a sectional view taken along line 3 โ 3 of FIG. 2 .
FIG. 4 is a fragmentary side elevational view of the seat track protector assembly of FIG. 1 illustrating a first operational state.
FIG. 5 is a view similar to FIG. 4 of the seat track protector assembly illustrating a second operational state.
FIG. 6 is a fragmentary side elevational view of another embodiment, according to the present invention, of the seat track protector assembly of FIG. 1 .
FIG. 7 is a side elevational view of yet another embodiment, according to the present invention, of the seat track protector assembly of FIG. 1 illustrating first operational state.
FIG. 8 is a rear elevational view of the seat track protector assembly of FIG. 7 .
FIG. 9 is a front elevational view of the seat track protector assembly of FIG. 7 illustrating a second operational state.
FIG. 10 is a front elevational view of the seat track protector assembly of FIG. 7 illustrating a third operational state.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and in particular FIGS. 1 through 3, one embodiment of a seat track protector assembly 10 , according to the present invention, is shown for a vehicle, generally indicated at 12 . The vehicle 12 includes a vehicle body (partially shown) having a floor 14 and a seat 16 mounted to the floor 14 . The seat 16 has a seat portion 18 operatively connected to the floor 14 by one or more seat rails or tracks, generally indicated at 20 . It should be appreciated that, except for the seat track protector assembly 10 , the vehicle 12 and seat 16 are conventional and known in the art.
The seat tracks 20 are spaced laterally and extend longitudinally. Each seat track 20 includes a lower track member 24 . The lower track member 24 is generally โUโ shaped with a flange 26 at each upper end extending laterally for a function to be described. The lower track member 24 is connected to a seat riser (not shown) of the floor 14 by suitable means such as fasteners (not shown). It should be appreciated that there are two seat tracks 20 per seat and that the lower track member 24 is attached to an outboard and inboard seat riser. It should also be appreciated that the seat track protector assembly 10 is used on each seat track 20 .
Each seat track 20 also includes an upper track member 28 to slide along the lower track member 24 . The upper track member 28 has an inverted general โUโ shape with: a first flange 30 at each lower end extending laterally. The first flange 30 overlaps the flange 26 of the lower track member 24 and slides relative thereto. The upper track member 28 has a second flange: 32 extending perpendicularly from the first flange, 30 and a third flange 34 extending perpendicularly and laterally from the second flange 32 to cover a side edge of the flange 26 of the lower track member 24 . The track members 24 and 28 are made of a rigid material such as metal. The upper track member 28 , is connected to a seat pan (not shown) by suitable means such as welding. It should be appreciated that the seat tracks 20 are conventional and known in the art. It should also be appreciated that the lower track member 24 is fixed and the upper track member 28 may be moved manually or be powered by suitable means (not shown).
Referring to FIGS. 2 and 3, the seat track protector assembly 10 , according to the present invention, is mounted to the lower track member 24 of the seat track 20 . The seat track protector assembly 10 includes a channel member 36 disposed within the lower track member 24 . The channel member 36 extends longitudinally with a generally โUโ cross-sectional shape. The channel member 36 has a base wall 38 and a pair of opposed sidewalls 40 at the lateral sides thereof extending upwardly and generally perpendicular to the base wall 38 to form a channel 42 . The channel member 36 has a pair of opposed end walls 44 at the longitudinal ends thereof extending upwardly and generally perpendicular to the base wall 38 . The end walls 44 have an aperture 46 extending longitudinally therethrough. The aperture 46 is generally rectangular in shape for a function to be described. The channel member 36 is made of a metal material such as steel.
The seat track protector assembly 10 also includes a tape 48 for securing the channel member 36 to the lower track member 24 . The tape 48 is of an adhesive type, preferably a structural bonding tape disposed between the base wall 38 of the channel member 36 and a base wall of the lower track member 24 to adhesively secure the channel member 36 to the lower track member 24 . The tape 48 is generally planar and rectangular in shape. It should be appreciated that the tape 48 is conventional and known in the art.
The seat track protector assembly 10 includes a plurality of bumpers 50 disposed between the sidewalls 40 of the channel member 36 and sidewalls of the lower track member 24 . The bumpers 50 are made of an elastomeric material such as rubber. The bumpers 50 are generally planar and rectangular in shape. The bumpers 50 limit the channel member 36 from contacting the lower track member 24 . It should be appreciated that the bumpers 50 are conventional and known in the art.
The seat track protector assembly 10 also includes a pin 52 extending longitudinally and through the apertures 46 of the channel member 36 . The pin 52 is generally rectangular in cross-sectional shape. The pin 52 is made of a metal material such as steel. The pin 52 extends longitudinally beyond the end walls 44 of the channel member 36 for a function to be described. It should be appreciated that the apertures 46 of the channel member 36 and the cross-sectional shape of the pin 52 are complementary to prevent rotation of the pin 52 .
The seat track protector assembly 10 includes an end or trim cover 54 disposed about one end of the pin 52 . The cover 54 is made of a rigid material such as a metal material such as steel. The cover 54 may be of any suitable shape and is attached to the end of the pin 52 by suitable means such as welding. It should be appreciated that the cover 54 covers a longitudinal end of the seat tracks 20 .
The seat track protector assembly 10 also includes a spring 56 disposed about the pin 52 between an end of the pin 52 and one of the end walls 44 of the channel member 36 . The spring 56 is of a coil type for a function to be described. It should be appreciated that a compression of the spring 56 is equal to a longitudinal travel of the seat 16 .
The seat track protector assembly 10 further includes a spring retainer 58 for retaining the spring 56 on the pin 52 . The spring retainer 58 is generally rectangular in shape and has an aperture 60 extending therethrough. The aperture 60 is generally rectangular in shape to allow the pin 52 to extend therethrough. The spring retainer 58 is a plate made of a rigid material such as plastic. The seat track protector assembly 10 further includes a pin member 62 such as a hairpin or cotter pin that extends into an aperture 64 in the pin 52 adjacent the spring retainer 58 . It should be appreciated that the pin member 62 prevents the spring retainer 58 from exiting the pin 52 .
Referring to FIGS. 4 and 5, in operation of the seat track protector assembly 10 , the seat track protector assembly 10 is spring-loaded and self-contained, which fits to the lower track member 24 of the seat tracks 20 for the seat 16 as illustrated in FIG. 4 . As the seat 16 is moved longitudinally rearward as indicated by the arrow A, the upper track member 28 engages the cover 54 . As a result, the cover 54 and pin 52 move rearward to compress the spring 56 between the spring retainer 58 and the end wall 44 of the channel member 36 as illustrated in FIG. 5 . As the seat 16 moves longitudinally forward, the spring 56 urges the spring retainer 58 away from the end wall 44 of the channel member 36 , causing the pin 52 and cover 54 to be returned to cover the end of the lower track member 24 as illustrated in FIG. 4 . It should be appreciated that the cover 54 protects both the upper and lower track members 24 and 28 and moves rearward as the upper track member 28 moves rearward relative to the lower track member 24 .
Referring to FIG. 6, another embodiment, according to the present invention, of the seat track protector assembly 10 is shown. Like parts of the seat track protector assembly 10 have like reference numerals increased by one hundred (100). In this embodiment, the seat track protector assembly 110 has the spring 156 disposed about the pin 152 and in the channel 142 of the channel member 136 . The seat track protector assembly 110 also has the spring retainer 158 disposed about the pin 152 and in the channel 142 . The operation of the seat track protector assembly 110 is similar to the seat track protector 10 . It should be appreciated that the seat track protector assembly 10 and 110 are self-contained units, which fit into the lower track member 24 .
Referring to FIGS. 7 through 10, yet another embodiment, according to the present invention, of the seat track protector assembly 10 is shown. Like parts of the seat track protector assembly 10 have like reference numerals increased by two hundred (200). In this embodiment, the seat track protector assembly 210 has only the cover 254 and the spring 256 . The cover 254 has at least one, preferably a plurality of projections 270 extending axially. The spring 256 has one end connected to one of the projections 270 , preferably a center projection 270 a and the other end is connected to the lower track member 24 via a retainer 271 . The other projections 270 fit within the end of the lower track member 24 when the cover 254 is adjacent the lower track member 24 . The operation of the seat track protector assembly 210 is similar to the seat track protector 10 in that, as the seat 16 is moved longitudinally rearward as indicated by the arrow A, the upper track member 28 engages the cover 254 to move the cover 254 rearward as illustrated in FIG. 10 and the spring 256 causes the cover 254 to be returned to cover the end of the lower track member 24 when the upper track member 28 moves forward as illustrated in FIGS. 7 and 9.
The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.
Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.
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A seat track protector assembly is provided for a vehicle. The seat track protector assembly includes a cover adapted to be disposed adjacent an end of a lower track member for a seat of the vehicle and adapted for movement by an upper track member of the seat. The seat track protector assembly also includes a spring cooperating with the lower track member and the cover to return the cover toward the end of the lower track member when the cover is moved away from the end of the lower track member by the upper track member.
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CROSS-REFERENCE TO RELATED APPLICATION AND CLAIM OF PRIORITY
[0001] This is a utility application claiming priority from U.S. provisional patent application No. 61/305,621, filed Feb. 18, 2010, entitled โMethod and Apparatus For Single-Trip Wellbore Treatmentโ, Gregg W. Stout, inventor.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to apparatus and methods for oil and gas wells to enhance the production of subterranean wells, either open hole or cased hole, and more particularly to improved multizone stimulation systems.
[0004] 2. Brief Description of the Prior Art
[0005] Wells are drilled to a depth in order to intersect a series of formations or zones in order to produce hydrocarbons from beneath the earth. The drilled wells are cased and cemented to a planned depth and then may cased and cemented or a portion left open hole. Producing formations intersected with the well bore in order to create a flow path to the surface. Stimulation processes, such as fracing or acidizing or other chemicals or proppants, are used to increase the flow of hydrocarbons through the formations. The formations may have reduced permeability due to mud and drilling damage or other formation characteristics. In order to increase the flow of hydrocarbons through the formations, it is desirable to treat the formations to increase flow area and permeability. This is done most effectively by setting either open-hole packers or cased-hole packers at intervals along the length of the wellbore. These packers isolate sections of the formations so that each section can be better treated for productivity. Between the packers is a frac port and in some cases a sliding sleeve or a gravel pack screen with sliding sleeves. In order to direct a treatment fluid through a frac port and into the formation, a seat may be placed either on top of a sliding sleeve or below a frac port. A ball or plug may be dropped to land on the seat in order to direct fluid through the frac port and into the formation.
[0006] One method places a series of ball seats below the frac ports with each seat size accepting a different ball size. Smaller diameter seats are at the bottom of the completion and the seat size increases for each zone as you go up the well. For each seat size there is a ball size so the smallest ball is dropped first to clear all the larger seats until it reaches the appropriate seat. In cases where many zones are being treated, maybe as many as 20 zones, the seat diameters have to be very close. The balls that are dropped have less surface area to land on as the number of zones increase. With less seat surface to land on, the amount of pressure you can put on the ball, especially at elevated temperature, becomes less and less. This means you can't get adequate pressure to frac the zone or the ball is so weak, the ball blows through the seat. Furthermore, the small ball seats reduce the I.D. of the production flow path which creates numerous other problems. The small I.D. prevents re-entry of other downhole devices, i.e., plugs, running and pulling tools, shifting tools for sliding sleeves, perforating gun size (smaller guns, less penetration), and of course production rates. In order to remove the seats, a milling run is needed to mill out all the seats and any balls that remain in the well.
[0007] The size of the ball seats and related balls limits the number of zones that can be treated in a single trip. It would be advantageous to replace the use of the ball seats with a workstring actuated isolation device, such as a flapper or rotating ball, to allow the treatment of an unlimited number of zones in a single trip.
[0008] Another method is that disclosed in U.S. Pat. No. 7,543,634 B2. This method places sleeves in the I.D. of the tubing string. These sleeves cover the frac ports and packers are placed above and below the frac ports. Varying sizes of balls or plugs are dropped on top of the sleeves and when pressing down the tubing, the pressure acts on the ball and the ball forces the sleeve downward. Once again you have the restriction of the ball seats and theoretically, and most likely in practice, when the ball shifts the sleeve downward, the frac port opens and allows the force due to pressure diminish off before the sleeve is fully opened. If the ball and sleeve remain in the flow path, the flow path is restricted for the frac operation.
[0009] It would be advantageous to have a system that had no ball seats that restrict the I.D. of the tubing and to eliminate the need to spend the time and expense of milling out the ball seats, not to mention the debris created by the milling operation. Also it would be beneficial to have a system that fully opens the sliding sleeve before sleeve activating pressure bleeds down, to assure the sleeve is fully opened before treating the formation.
[0010] Furthermore, it would be greatly advantageous to eliminate the time and logistics required for dropping numerous balls into the well, one at a time, for each zone in the well to be treated.
[0011] In some well completions the operator may want to perforate below the packer. If the completion has small I.D. ball seats, the maximum O.D. of the perforating guns must drift through the ball seats. Small I.D. ball seats mean small O.D. perforating guns. It is well known in the industry that the smaller the O.D. of the perforating gun, the less the penetrating performance of the gun. It would be very advantageous to be able to run the largest O.D. gun possible inside of the tubing to achieve the greatest penetration through the tubing and casing walls to get the deepest penetration into the formation.
[0012] Some zones in the formation are very close together or water is nearby. Fracturing programs sometimes want to limit the length of the zone to be treated so isolation packers with sliding sleeves need to be set very close together. To achieve this it would be beneficial to have a short compact packer-sliding sleeve assembly where several assemblies could be stacked closely together. One of the advantages of the present invention is to integrate to components of the packer and sliding sleeve to produce a reduced overall length apparatus to address the completion of closely positioned zones.
SUMMARY OF THE INVENTION
[0013] A single trip multizone well treating method and apparatus provides a means to progressively stimulate individual zones through a cased or open hole well bore. The need to drop and mill balls and seats for each zone or run hydraulic control lines from the surface to actuate a series of isolation devices has been eliminated. Also, the I.D. restriction created by balls and seats has been eliminated to provide a full bore completion. The full bore completion allows use of larger perforating guns when thru-tubing perforating is desired. A unique feature of this system is that the operator can progressively treat each zone up the hole by moving the workstring up and down a short distance to release a flapper valve selectively for each zone. Applied pressure to the flapper both opens a sliding sleeve and sets a packer and then shifts the flapper below the frac port so a pumping treatment can commence. The apparatus is presented as a โFrac Moduleโ that consists of three major components, a packer, a sliding sleeve, and a workstring actuated fluid isolation device which are integrated together in an assembly that would be shorter in length for closely placed zones. One Frac Module is used per zone and the frac module is stacked with tubing spacers through all zones that need treatment and zonal isolation.
[0014] Stated a slightly different way, the invention provides a full bore, single trip multizone subterranean well treating apparatus. The apparatus is carried into the well on a tubular workstring, which may also be later used as the production tubing. A tubular housing is defined on the workstring and includes a central first fluid passageway therethrough. A plurality of treatment modules are provided on the housing, each module being pre-determinedly spaced on the housing for operable alignment with a zone in the well. Each module includes a tubular housing member with a treatment fluid port therein and a control chamber selectively communicable with the port. First and second spaced sealing mechanisms, such as packers, are provided to isolate the selected zone from other portions of the well. A first full bore valving mechanism is initially positioned in the housing in open position and is selectively activatable to closed position to block fluid under pressure from being transmitted within the tubular housing and across the valving member. Activation means are provided for the first valving means and responsive to a first level of pressure applied through the workstring to open the port and place a chamber in fluid communication with a fluid passageway within the housing. Pressure within the housing member above the first level further activates the a first sealing means, or packer, to set position. A second fluid flow passageway in the housing includes a blocked port opening to the interior of the housing, and the port is opened during activation of the first sealing means, or packer. A second activation means, such as a sleeve, is responsive to a pressure level in said tubing in excess of that required to set the second sealing means and to open a treatment port. In each of the modules upstream of the module used to isolate the first zone to be treated, there is provided a full bore valve in initial open position but shiftable to closed position by mechanical manipulation of the workstring to block fluid flow across the valve.
[0015] This invention provides an improved multizone stimulation system to improve the conductivity of the well formations with reduced rig time and no milling. The equipment for all zones can be conveyed in single workstring trip and frac units can stay on location one time to treat all zones.
[0016] In a preferred embodiment, work string weight is set down and pressure is applied to the lowermost isolation device, such as a flapper. The flapper is released and allowed to close. The flapper is mounted on a sleeve that is shear pinned. A low initial pressure shifts the flapper and sleeve downward to open a pressure port. Tubing pressure enters the port to shift the sliding sleeve downward to an open position to uncover the frac port and simultaneously begin setting a packer located immediately above the frac port. The setting motion within the packer opens a port to the tubing to allow tubing pressure to travel up a control line to the next upper zone to activate a flapper release mechanism, but the next upper flapper does not close at this point. Tubing pressure is increased to fully set the packer and the flapper/sleeve shears and shifts downward to a position below the frac port. In this position, the flapper/sleeve then rests on top of the sliding sleeve. With the frac port now fully open, the first zone is treated while the workstring remains in the set-down position. After the stimulation of the lower zone, the work string is picked up a short distance to release the flapper only in the next upper zone so the next upper zone can be treated. All upper zones are then progressively treated using the same process. A set-down and pickup type packer can be used above all of the frac Modules and above the uppermost set of perforations, assuming all zones were perforated initially. A production packer can be run in the string above the set-down packer, if desired, and be set after all zones are completed. Once the well is nippled-up the well can be put on production. If flapper valves are used, they will open and allow flow. It is also possible to make a trip into the well and break the frangible flapper discs. If sliding sleeves are used, shifting tools can be run in to open or close the sliding sleeves.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIGS. 1 a , 1 b , and 1 c placed end-to-end make up a schematic view of the present invention.
[0018] FIG. 2 is a schematic view of three Frac Modules assembled in tandem in a well completion.
[0019] FIG. 3 is a schematic view of three cased and perforated zones isolated with a completion string of tools.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] With reference to FIG. 1 a , a schematic of the present invention shows a 90 degree lengthwise cross-section of the apparatus. This portion of the apparatus is the packer with only a packing element. A packer may be used that has a slip system added and a packer may be used that has a release devise added. Top sub 1 has a connecting thread at the top end 2 , an internal thread 3 , and o-ring seals 4 and 5 . Shear Screws 6 shearably connect Top Sub 1 to Shear Ring 7 . Shear Screws 8 shearably connect the Top Sub 1 to Push Sleeve 12 . The hole 9 communicates with hole 13 . A fitting 10 seals in hole 9 and also connects to hydraulic control line 11 . Hole 13 is located inside of Flow Body 14 . Seals 15 , 16 , 4 , 5 seal between the Top Sub 1 and the Flow Body 14 to isolate flow paths 9 and 13 from pressure inside the tool 22 or outside the tool 23 . Port 20 has Seals 17 and 18 to seal off Port 20 with Push Sleeve 12 . Seals 18 and 19 with Push Sleeve 12 seal off port 21 to prevent pressure in tool 22 from entering port 20 . Seals 24 and 25 in Flow Body 14 , seal with Packer Mandrel 26 .
[0021] Thread 27 attaches Flow Mandrel 14 to Packer Body 26 . Packing Element 28 rests on the Packer Mandrel 26 and between faces 30 and 31 . Gage Ring 29 is attached to Piston 32 with thread 37 . Piston 32 slides between Piston Housing 38 and Mandrel 26 and seals 33 and 34 act as piston seals. Body Lock Ring 35 threadably engages Piston Housing threads 44 so items 35 and 44 move together. Body Lock Ring 35 sets on smooth S surface 45 and at a later point in time engages Piston threads 46 . Screw 36 prevents rotation of Body Lock Ring 35 relative to Piston 32 . Connector 43 is attached to Mandrel 26 with thread 39 and seals 41 and 42 create a seal between items 25 and 43 . Hole 40 in Connector 43 communicates with Piston 32 .
[0022] With reference to FIG. 1 b , Connector 43 and hole 40 continue in the apparatus. Lower Pickup Sleeve 49 is attached to Connector 43 with thread 53 and seals 47 and 48 seal between the items 43 and 49 . Hole 40 communicates with chamber 54 . Release Sleeve 55 slides within Connector 43 and seal surface 52 seals at O-rings 50 and 51 . Upper Pickup Sleeve 56 slides inside of Lower Pickup Sleeve 49 . Surfaces 57 and 58 engage during pickup while surfaces at location 70 make contact during set-down.
[0023] Dynamic Seals 59 , 60 , and Static Seals 61 , and 62 seal on seal surface 63 of the Upper Pickup Sleeve 56 . Upper Pickup Sleeve 56 is connected to Housing 65 with threads 64 .
[0024] Housing 65 attaches to Frac Port Housing 66 with thread connection 67 and seals 68 and 69 seal between items 65 and 66 . Seals 72 and 73 are positioned on Release Sleeve 55 and form a seal on Frac Port Housing 66 at seal surface 71 . Shear Ring 74 is shearably connected to Release Sleeve 55 with shear screws 75 . Shear Ring 74 is trapped in pocket 76 so Release Sleeve 55 can't move up or down. Shifting Profile 77 inside of Release Sleeve 55 engages a shifting tool (not shown) so that the shifting tool can engage the profile 77 and move the Release Sleeve 55 upward.
[0025] The bottom of Release Sleeve 55 has a finger 78 attached. The finger 78 engages the Flapper 79 at location 84 . The Flapper 79 is affixed to Flapper Seat Sleeve 81 with axle 80 so the Flapper 79 is free to pivot around axle 80 . Flapper Seat Sleeve 81 is attached to Seat Housing 83 with shear pin 82 . Flapper Seat Sleeve 81 can slide downward into Seat Housing 83 until faces 84 and 85 come into contact. Seat Housing 83 is shear pinned to Frac Port Housing 66 with Shear Pins 86 . Seals 87 , 88 , 89 , and 90 are positioned in Barrel 91 and prevent pressure from moving from location 22 to location 23 or vice-versa.
[0026] One or more Frac Ports 92 are located in Frac Port Housing 66 . The ports 92 go completely through the wall of the Frac Port Housing 66 . The Frac Port Housing has gun drilled hole 93 and 94 that do not intersect the Frac Ports 92 or Shear Screw hole 86 . Gun drilled hole 93 and 94 are isolated from each other by plug 95 and seals 96 , 97 , 98 , 99 , and 102 . Port 100 communicates with gun drilled hole 93 and Port 101 communicates with gun drilled hole 94 , or vice-versa.
[0027] Gun Drilled Hole 93 communicates with chamber 103 and acts on seals 104 and 105 located inside of Housing 65 and Release Sleeve 55 . Seals 104 and 105 are located on the I.D. and O.D. for Shift Piston 106 . Therefore, pressure in gun drilled hole 93 acts on Shift Piston 106 and is isolated from pressures 22 and 23 .
[0028] Shift Piston 106 is shearably attached to Upper Pickup Sleeve 56 with shear pin 111 . Expanding Lock Dogs 107 and 109 are located in retaining slots on Shift Piston 106 . Lock Dog 107 is designed to engage in groove 108 inside of Lower Pickup Sleeve 49 and Lock Dog 109 is designed to engage in groove 110 on the O.D. of Release Sleeve 55 . Locking Keys 112 fit into slots 115 that are located in Upper Pickup Sleeve 56 . The Locking Keys 112 have teeth that expand into the I.D. thread profile 114 of Lower Pickup Sleeve 49 . Extended portion 113 of Shift Piston 106 slides under Locking Keys 112 in order to expand and engage the teeth into profile 114 thus locking the Lower Pickup Sleeve 49 to the Upper Pickup Sleeve 56 during the run-in configuration.
[0029] With reference to FIG. 1 c , note the continuation of gun drilled holes 93 and 94 in Frac Port housing 66 . In this figure, Gun Drilled Hole 93 communicates with control line 116 which attaches control line 117 which communicates with Shift Piston 106 . Control Line 117 becomes the same control line as Control Line 11 in FIG. 1 a so that Frac Modules in a lower zone can act on Shift Piston 106 .
[0030] Gun Drilled Hole 94 communicates with chamber 118 and chamber 118 is adjacent to Sliding Sleeve Piston 121 . The Sliding Sleeve Piston 121 is positioned between Frac Port Housing 66 and Sliding Sleeve 124 and seals between the two with seals 119 and 120 . The Sliding Sleeve Piston 121 is shearably attached to Sliding Sleeve 124 with Shear Screws 122 . The Sliding Sleeve Piston 121 houses a Lock Ring 123 which engages shoulder 127 . Chamber 128 is below the Sliding Sleeve Piston 121 and communicates with ports 129 which communicate with pressure 23 . In summary, port 101 communicates with chamber 118 to communicate with Sliding Sleeve Piston 121 and the lower side of the Piston communicates with pressure 23 .
[0031] Frac Port Housing 66 is connected to Sleeve Housing 130 with thread 131 . Bottom Sub 135 is connected to Sleeve Housing 130 with thread 132 and seals 133 and 134 create a seal between the two. The Bottom Sub 135 has pin thread 136 facing down.
[0032] Sliding Sleeve 124 always isolates chamber 128 from pressure 22 with upper and lower seals 125 and 126 . The Sliding Sleeve 124 has collets 138 and 139 machined into the sleeve. These collets either engage in recess 144 or recess 143 to hold the Sliding Sleeve 124 in either the open or closed position. Anti-rotation Keys 137 slide in slot 130 and set in slots 145 located in the Sliding Sleeve 124 . Key 137 shoulder 141 engages Bottom Sub 135 shoulder 142 to limit downward movement of Sliding Sleeve 124 so that Collets 138 and 139 are not loaded in compression. Collets 138 and 139 engage a shifting tool, not shown, used to either shift the Sliding Sleeve 124 open or closed.
[0033] With reference to FIG. 2 , Frac Module 146 is comprised of the apparatus described in the combination of FIGS. 1 a , 1 b , and 1 c . This illustration shows three Frac Modules 146 a , 146 b , and 146 c placed around producing zones 147 and 148 and inside casing 149 with the casing surrounded by cement 150 . Perforations 151 and 152 are in communication with the Frac Port Windows 92 shown in FIG. 1 b . Packing Elements 153 seal on the I.D. of casing 149 in order to isolate zones 147 and 148 from each other. Obviously, this can be done on many zones located in the well bore. Control lines 117 allow pressure communication from Frac Module 146 c to Frac Module 146 b and then from Frac Module 146 b to Frac Module 146 a and so on for every zone to be treated.
Description of Preferred Operation
[0034] With reference to the example in FIG. 3 , a typical completion is shown but many variations of this occur as know by those who are familiar with the variations that occur in configuring well completions.
[0035] A well has been drilled, cased, cemented, and perforated, although this system may be used in open hole completions with selection of the appropriate packers. Casing 149 is shown in this example with perforations 151 , 152 , and 154 in the casing. A sump packer 155 is properly located and set below the lowermost zone 154 .
[0036] A โcompletion stringโ is run into the well consisting of a Locator Snap Latch Seal Assembly 156 , Tubing Spacer 160 , Frac Module 146 c , Tubing Spacer 159 , Frac Module 146 b , Tubing Spacer 159 , Frac Module 146 a , Tubing Spacer 161 , Service/Production Packer 157 , and releasable work string 158 where a production string can be run to replace to workstring at a later date in the completion. The length of Tubing Spacers 159 and 160 are made to position the Frac Modules 146 between the producing zones 162 , 163 , and 164 . The Service/Production Packer 158 can be of the straight pick-up and set-down style where no rotation is required to move the packer up the hole and re-seal.
[0037] The single trip completion string is landed in sump packer 155 . The location of Sump Packer 155 was based on logs of the zones so that all equipment could be spaced out properly. Therefore, by locating the completion assembly on the Sump Packer 155 , all Frac Modules 146 will be properly positioned in the well. Snap Latch Seal Assembly 156 can be used to verify position of the system before setting any of the above packers. The Locator Snap Latch Seal Assembly 156 seal in the sump packer 155 and will locate on the bottom of the Sump Packer, although โtop of the packerโ snap latch seal assemblies can be used as well. The Locator Snap Latch Seal Assembly 156 is designed to allow pulling of the Work String 158 to get a load indication on the Sump Packer 155 and then snap back in and put set-down weight on the Sump Packer 155 . The load required to snap out is recorded so an operator can know how much to pull with the workstring before snapping out. Collets on the Locator Snap Latch Seal Assembly 156 can be designed to snap at specified loads. The above steps are common in the art of completing wells.
[0038] To explain operation of the Frac Modules, this discussion will begin with stimulation of the lower-most zone 164 . The lowermost Frac Module 146 c is assembled slightly different from all the above frac Modules 146 b , 146 a , and 146 z, z being any number of zones. In Frac Module 146 c , referring to FIG. 1 b , the Flapper 79 will be installed in the released position, i.e., finger 78 will be disengaged from location 84 , so the Flapper 78 is free to go to the closed position against Flapper Seat Sleeve 81 and also be free to allow fluid from below the Flapper 79 to open the Flapper 79 to allow the work string 158 to fill with well fluid during tripping into the well and stinging into Sump Packer 155 with Locator Snap Latch Seal Assembly 156 . Also control line hole 93 is plugged at fitting 116 .
Reference Point to Repeat Process
[0039] After set-down weight is placed on the sump packer 155 , maybe 10,000 to 20,000 pounds, the Service Packer 157 will be set with set-down weight, and the Hydrils can be closed on the workstring 158 . Frac lines can be attached at the surface and pressure can be applied down the workstring 158 against the Flapper 79 in Frac Module 146 c.
[0040] Referring to FIG. 1 a , 1 b , and 1 c it will be explained 1) how the packing element 28 , or a packing element plus a slip system (not shown), is actuated, and 2) how the Sliding Sleeve 124 is opened, and 3) how the Flapper/Seat Assembly, items 79 , 80 , 81 , 83 , moves downward below the Frac Port 92 and lands on top of the Sliding Sleeve 124 , and 4) how the Lower Pickup Sleeve 49 is unlocked, and 5) how the Flapper 79 in Frac Module 146 b , in the next upper zone 163 , is put into the prepare for release mode.
[0041] In operation, the workstring 158 pressure 22 acts on the closed Flapper 79 in Frac Module 146 c . Shear pin 82 is set at a lower shear value than shear screw 86 so pressure 22 acts on seal 98 and Flapper 79 and Flapper Seat Sleeve 81 causing Shear Pin 82 to shear. Face 82 moves downward to contact face 85 so that the Flapper Seat Sleeve 81 shifts below ports 100 and 101 . Pressure 22 travels thru port 101 and into Gun Drilled Hole 94 to act on Sliding Sleeve Piston 121 . Hole 94 is plugged with plug 95 so pressure only acts on piston 121 . The piston 121 leads shear screw 122 which loads Sliding Sleeve 124 and shifts the Sliding Sleeve 124 downward to the full open position where the shoulder 141 of Key 137 contacts Bottom Sub shoulder 142 . Frac Port 79 is now open and pressures 22 and 23 communicate.
[0042] Pressure 22 also travels through port 100 and up Gun Drilled Hole 93 to act on seals 104 and 105 of Shift Piston 106 to shear pins 111 and move Shift Piston 106 upward. Upward movement of Shift Piston 106 releases Locking Keys 112 so that Lower Pickup Sleeve 49 and Upper Pickup Sleeve 56 are free to move until surfaces' 57 and 58 make contact. Although, surfaces 57 and 58 will not make contact at this time because the operator has put set-down weight on the โcompletion stringโ and also because internal pressure 22 will not pump the tool open, or faces 57 and 58 apart, because seals 50 , 51 , 72 , and 73 on Release Sleeve 55 balance the effects of internal pressure 22 . As pressure 22 continues to act on Piston 106 , Piston 106 continues to move upward until Expanding Lock Dogs 107 engage groove 108 and so Piston 106 is now locked to Lower Pickup Sleeve 49 and they will move together. Simultaneously, Lock Dog 109 engages groove 110 located in Release Sleeve 55 . The shoulder 166 of Lock Dog 109 does not push on shoulder 165 of groove 110 of the Release Sleeve 55 at this time because shoulder 168 of lock dog 107 contacts shoulder 165 of groove 108 of the Lower Pickup Sleeve 49 .
[0043] In Frac Module 146 c , the piston length is such that when Piston 106 is locked in groove 108 , pressure 22 is allowed to pass seal 104 , move into chamber 54 , and travel up hole 40 of Piston Housing 38 . Pressure 22 can now act on seals 33 and 34 of Piston 32 to begin setting the packer or packing element 28 . The Piston 32 causes face 31 of the Gage Ring 29 to begin compressing packing element 28 against face 30 of Push Sleeve 12 . Compressive loads to compress packing element 28 can vary from as low as 10,000 pounds up to 50,000 pounds depending on the casing size and type of packer. This load is transmitted into Push Sleeve 12 to shear pins 8 and surface 30 moves up until Push Sleeve face 170 contacts Shear Ring 7 at face 171 . At this point, recess 172 of Push Sleeve 12 allows pressure 22 to enter port 21 , travel through recess 172 and into port 20 and into gun drilled hole 13 . Gun drilled hole 13 is isolated with seals 4 , 5 , 15 , 16 and connects to hole 9 in Top Sub 1 . Hole 9 has connector 10 that connects control line 11 which is the same as control line 117 that travels up to Frac Module 145 b , see FIG. 3 , and connects to fitting 116 and travels into hole 93 , see FIG. 1 c . Pressure 22 travels all the way up to Shift Piston 106 located in Frac Module 146 b.
[0044] In Frac Module 146 b , pressure 22 acts on seals 104 and 105 of Shift Piston 106 to shear pins 111 and move Shift Piston 106 upward. Upward movement of Shift Piston 106 releases Locking Keys 112 so that Lower Pickup Sleeve 49 and Upper Pickup Sleeve 56 are free to move until surfaces 57 and 58 make contact.
[0045] Although in Frac Module 146 b , surfaces 57 and 58 will not make contact at this time because the operator has put set-down weight on the โcompletion stringโ and also because internal pressure 22 will not pump the tool open, or faces 57 and 58 apart, because seals 50 , 51 , 72 , and 73 on Release Sleeve 55 balance the effects of internal pressure 22 . As pressure 22 continues to act on Piston 106 , Piston 106 continues to move upward until Expanding Lock Dogs 107 engage groove 108 and so Piston 106 is now locked to Lower Pickup Sleeve 49 and they will move together. Simultaneously, Lock Dog 109 engages groove 110 located in Release Sleeve 55 . The shoulder 166 of Lock Dog 109 does not push on shoulder 165 of groove 110 of the Release Sleeve 55 at this time because shoulder 168 of lock dog 107 contacts shoulder 165 of groove 108 of the Lower Pickup Sleeve 49 . In this Frac Module the length of Shift Piston 106 does not allow pressure 22 to pass seals 104 and 105 , therefore the packer in Frac Module does not begin to set until workstring pickup occurs that allows pressure 22 to pass the seals 104 or 105 to get pressure to the packer setting piston. At this point the 146 b Frac Module has been prepared for pickup to release the Flapper 79 .
[0046] Going back to Frac Module 146 c , pressure 22 is increased against the Flapper 79 until packer setting load increases enough to shear Screws 6 in Ring 7 . Push Sleeve 12 moves upward until faces 30 and 169 line up to create an anti-extrusion surface for packing element 28 . Also, port 21 is isolated with seals 18 and 19 . Pressure 22 is increased until full setting pressure 22 of the packer is reached. Full setting pressure 22 is controlled by Shear screws 86 that engage Seat Housing 83 .
[0047] At this point, the Sliding Sleeve is fully opened and the packer is fully set and the upper Frac Module has an activated Flapper Release sleeve 55 .
[0048] Pressure 22 is increased until Shear Screws 86 shear and the Flapper Assembly 79 , 80 , 81 , 83 and related seals and shear pins, shift downward below the Frac Port 92 and set on top of Frac Sleeve 124 at a position below the bottom edge of the Frac Port windows. The flow path to and thru the Frac Ports is now fully open and zone 164 is ready for stimulation.
[0049] Once the stimulation is complete, it's time to treat the next upper zone 163 . The workstring is picked up a distance โXโ. This is when shoulders 57 and 58 make contact and during the movement thru distance โXโ Lock Dog Shoulder 166 engages Release sleeve shoulder 165 which shifts Release Sleeve 55 upward. The Release Sleeve Finger 78 disengages Flapper 79 and allows Flapper 79 to close. The operator is now ready to begin operations on zone 163 as described above beginning at Reference point to repeat process.
[0050] The above process repeats for all zones. The pickup length โXโ can be measured at the rig floor by marking pipe for each zone. The occurrence of length โXโฒ at the surface verifies that the Flapper 79 has been released in each zone. As zones are treated, โXโ increases at the rig floor. If a Flapper 79 does not release, the Release Sleeve 55 may be shifted upward to release the Flapper 79 using a shifting tool that locates in profile 77 of Release Sleeve 55 .
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The apparatus consists of a tubular housing carried into the well on a workstring. A series of spaced isolation modules is provided for each zone and carried into the well on a tubular conduit. The first, or most downstream module includes first and second sealing mechanisms to isolate the first zone to be treated. A full bore valve is provided that is activated to closed position by an activating component in response to a source of a first level of pressure to isolate the first zone from other parts of the well bore. A port within the housing is initially blocked but selectively opened concurrently with the activation of the first sealing means to manipulate the second sealing mechanism to fully isolate the selected zone and the module. As the module is activated, a second full bore valve is activated to seal the interior of the housing upstream of the first module by manipulation of the tubular string.
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This is a continuation of application Ser. No. 08/633,943 filed Apr. 17, 1996 now pending.
FIELD OF THE INVENTION
The present invention relates to foamed plastic products and in particular to foamed plastic products having an outer protective skin which is extruded onto a resilient foamed product. The present invention is also directed to a method of manufacturing of the product.
BACKGROUND OF THE INVENTION
Various types of foamed plastic products are known and many of these products are produced by an extrusion process and produce a body portion which is relatively soft and resilient. Foamed polyethylene extruded products have been used for pipe insulation and have also been applied about structural members to provide a resilient outer cushion member. For example, foamed polyethylene cushion members have been applied to supports of gymnastic equipment, playground equipment, football standards and basketball poles to reduce the possibility of injury by striking of the structural member.
Foamed polyethylene can be extruded in a number of different shapes and is very valuable for the type of applications described above. Unfortunately, the product is relatively soft, and thus, the outer surface can tear easily, even though there is a very thin skin portion produced at the outer surface of the product during the extrusion process. To overcome this problem, fabric or tape have been applied about the product, and thus, provides a further surface which protects the underlying polyethylene from damage.
It would be desirable to have a foamed polyethylene product which has a tougher outer surface and one which can be produced in a cost effective manner.
Some solutions to the above problem have been proposed and one such solution involves using a separately foamed cylindrical sheath, which when exposed to heat shrinks about a product. The outer sleeves are placed about a polyethylene foamed product and then heat is applied to the sheath which then contracts to the diameter of the foamed polyethylene. This results in a two-stage process to marry the polyethylene foamed body and the outer sheath and it also requires somehow placing the foamed polyethylene body within the outer sheath. Examples of these types of structures and other arrangements are disclosed in U.S. Pat. No. 3,607,497, U.S. Pat. No. 3,813,272, U.S. Pat. No. 3,832,260, United 10
U.S. Pat. No. 4,634,615, U.S. Pat. No. 4,776,803, U.S. Pat. No. 4,780,158, U.S. Pat. No. 4,861,412, U.S. Pat. No. 4,950,352 and U.S. Pat. No. 5,360,048.
The present invention seeks to address the problems outlined above and produce a product which can be produced at a lower cost.
SUMMARY OF THE INVENTION
A polyethylene product according to the present invention comprises a foamed body portion of polyethylene in combination with an outer skin of non-foamed thermal plastic polyethylene which is fused to the foamed body portion.
According to an aspect of the invention, the foamed body portion has a boundary layer which has undergone thermal degradation and acts as an intermediary securing by heat sealing the outer skin to the body portion.
According to a further aspect of the invention, the skin includes a significant amount of colour pigment and the body portion has no appreciable or consistent colour pigment.
According to a further aspect of the invention, the skin of the product includes a significant amount of colour pigment and is of a colour unrelated to the body portion.
According to a further aspect of the invention, the outer skin includes a significant amount of ultraviolet stabilizers and the body portion does not have any significant amounts of ultraviolet stabilizers.
According to a further aspect of the invention, the polyethylene product with the body portion and the outer skin is of a generally cylindrical shape with an open central cavity which is placed about an elongate member, such that the elongate member is within the cavity whereby the polyethylene product provides an outer resilient sheath about the elongate body member.
A method of manufacturing, according to the present invention, produces a foamed polyethylene product having an outer tough sheath about a foamed polyethylene body portion. The method comprises extruding the foamed polyethylene body portion of a desired cross section, partially cooling the extruded body portion, and subsequently extruding a thin thermal plastic skin directly onto the body portion, resulting in fusing or heat sealing of the skin to an upper layer of the body portion, which due to the heat of the extruded skin, causes limited collapse of a boundary layer of the foamed body portion and securement of the skin to the body portion.
According to an aspect of the invention, the step of extruding the skin is conducted in-line with the step of extruding the polyethylene body portion and prior to complete cooling of the polyethylene body portion.
According to a further aspect of the invention, the method includes a step where the polyethylene body portion is pulled through a cylindrical extruding die which applies the extruded skin to the foamed body portion as it is pulled through the die.
According to a further aspect of the invention, the extruding die applies a skin having a thickness of approximately 0.003 inches.
According to a further aspect of the invention, the foamed body and the skin are of different colours.
According to yet a further aspect of the invention, 35 the cylindrical die includes a control arrangement for adjusting the extrusion discharge rate from the cylindrical die and the method includes adjusting of the control arrangement to produce a desired outer skin thickness.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in FIG. 1, which is a schematic view of the two-stage inline extrusion process;
FIG. 2 is a cross sectional view of the foamed polyethylene body after the first stage of the extrusion process; and
FIG. 3 is a cross sectional view of the final product.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
There are many known arrangement for extruding foamed polyethylene product and one such extruder is shown as 2 in the Figure. Product leaves the die of the extruder at 4 and almost immediately foams to full product dimensions, as generally indicated at 6 . Thus, the foamed product 6 , shortly downstream of the extruding die, is still relatively hot, but the outer skin 7 has formed and cooling is generally occurring from the outside in. Often, the extruded foamed polyethylene is exposed to cooling air or water cooling to reduce the time necessary to reduce the general temperature of the polyethylene foam. This foam has low thermal conductivity and this characteristic extends the time period required to fully cool the product. In any event, shortly downstream of the extrusion die 4 , the polyethylene foamed product passes through the cross head sheath extruder 8 . This extruder is basically a cylindrical ring through which the polyethylene foam is pulled and the cross head extrudes a skin onto the outer surface of the polyethylene foam using the foam for support.
Surprisingly, it was found that the cross head sheath extruder 8 can extrude a skin 11 directly onto the foamed polyethylene body 6 to produce the skinned product 14 . Extruding of the skin onto the body portion 14 only causes a limited amount of thermal degradation in the polyethylene foam body, which thermal degradation assists in adhering or fusing the skin 11 to the body portion. It would seem that the excellent thermal insulating properties of the foamed body portion protect the underlying layers of the foamed body portion from the higher temperatures of the hot skin and allow sufficient time for the skin to cool. There is no appreciable collapse or loss in the overall shape of the product. In this way, there is very little damage to the foamed body portion and a tough, preferably polyethylene skin can be easily applied about the foamed body portion.
FIG. 2 slows the foamed product 6 before extruding the skin on the product and FIG. 3 shows the skinned polyethylene product 14 .
A further feature of the present invention is the reduction in colour pigment that may be possible, in that the outer skin can have a very rich colour while the foamed body can be of a completely different colour or be essentially void of any colour pigment. Furthermore, if the foamed core was made of recycled material, the colour of the body portion does not matter, as the outer sheath provides the finished surface.
Another advantage of the present invention is using this method to first extrude the polyethylene foamed body and then apply a polyethylene outer skin to the foamed body. Any waste product is of polyethylene and as such, 25 can be recycled and reused as part of the material for extruding the polyethylene foamed body. Therefore, there is no waste material, as any scrap product can be recycled.
The outer skin can be of a material other than polyethylene such as polypropylene, surlyn, ethylene vinyl acetate, or other extrudable materials which, when extruded in this manner, become sufficiently secured to the polyethylene foam body.
The cross head sheath extruder 8 can have different cross heads for different types of product, for example larger product or smaller product, and different cross heads for different cross sections of product.
The foamed body portion 6 need not have a solid core and can have an open center, as would be the case with pipe insulation. This shape is most appropriate for feeding over an elongate structural member, such as a metal tube member or pipe member, and is particularly useful as a cover support member for a play structure. For example, it would be useful in protecting the support pole of a basketball hoop, for providing protection around a roll bar, for providing protection around play structures which have tubular members, such as climbing structures, and other similar types of applications.
The outer sheath also provides a very tough layer which allows other uses for the polyethylene foamed body portion. For example, this could be useful for boat bumpers or protective strips where the outer skin provides a toughness to the product which overcomes the problems associated with tearing of merely the body portion if it was used alone.
Another advantage of the present product is that the colour pigment can be concentrated in the outer skin and the inner foamed body does not need to have any particular colour pigment. This results in a cost saving and also allows a simple way to easily change the colour of the product during extrusion. For example, the line could be extruding one product having a black coating and at an appropriate time, the raw material for the cross head extruder could be replaced with a different raw material having a different colour pigment. There would be a short overlap where some scrap product may have to be recycled as the cross head extruder basically finishes extruding with the one colour and starts extrusion with the next, but the extrusion line can basically continue to run and there is no requirement to deal with changing colour regarding extruding of the foamed body portion.
A further advantage is that UV stabilizers can be placed in the outer skin and the inner foamed body does not need these stabilizers. This is important with respect to pipe insulation where the stabilizers significantly contribute to the cost of the product. By concentrating these ISV stabilizers in the outer skin, i.e. the portion which is exposed to the sun, the body portion can be absent of these stabilizers in many cases, causing no appreciable effect on longevity of the product.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
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A foamed polyethylene product has an outer sheath of non-foamed polyethylene fused to an underlying foamed body portion. Preferably, the product is produced in an in-line method when the foam body is extruded and subsequently the skin is extruded directly on the body portion. This process only causes limited thermal degradation of an outer layer of the body portion which improves adhesion of the skin to the body portion.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. application Ser. No. 09/211,109, filed Dec. 14, 1998 which was a continuation of International application No. PCT/EP97/02861, filed Jun. 2, 1997, which designated the United States and which was published in English.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0002] The invention relates to a method of placing a ceramic coating on an article of manufacture including a substrate formed of a nickel or cobalt-based superalloy, the method which includes placing an anchoring layer on the substrate and placing the ceramic coating on the anchoring layer.
[0003] The invention in particular relates to an article of manufacture to be used as a gas turbine component which is subjected to a hot and oxidizing gas stream streaming along it in operation. Such gas turbine components include gas turbine airfoil components like blades and vanes as well as gas turbine heat shield components.
[0004] U.S. Pat. No. 4,055,705 to Stecura et al.; U.S. Pat. No. 4,321,310 to Ulion et al., and U.S. Pat. No. 4,321,311 to Strangman disclose coating systems for gas turbine components made from nickel or cobalt-based superalloys. A coating system described includes a thermal barrier layer made from ceramic, which in particular has a columnar grained structure, placed on a bonding layer or bond coating which in its turn is placed on the substrate and bonds the thermal barrier layer to the substrate. The bonding layer is made from an alloy of the MCrAlY type, namely an alloy containing chromium, aluminum and a rare earth metal such as yttrium in a base including at least one of iron, cobalt and nickel. Further elements can also be present in an MCrAlY alloy; examples are given below. An important feature of the bonding layer is a thin layer developed on the MCrAlY alloy and used for anchoring the thermal barrier layer. This layer may be alumina, alumina mixed with chromium oxide or a double layer of alumina facing the thermal barrier layer and chromium oxide facing the bonding layer, depending on the composition of the MCrAlY alloy and the temperature of the oxidizing environment where the layer is developed. Eventually, an alumina layer may be placed purposefully by a separate coating process like physical vapor deposition (PVD).
[0005] U.S. Pat. No. 5,238,752 to Duderstadt et al. discloses a coating system for a gas turbine component which also incorporates a ceramic thermal barrier layer and a bonding layer or bond coating bonding the thermal barrier layer to the substrate. The bonding layer is made from an intermetallic aluminide compound, in particular a nickel aluminide or a platinum aluminide. The bonding layer also has a thin alumina layer which serves to anchor the thermal barrier layer.
[0006] U.S. Pat. No. 5,262,245 to Ulion et al. describes a result of an effort to simplify coating systems incorporating thermal barrier layers for gas turbine components by avoiding a bonding layer to be placed below the thermal barrier layer. To this end, a composition for a superalloy is disclosed which may be used to form a substrate of a gas turbine component and which develops an alumina layer on its outer surfaces under a suitable treatment. That alumina layer is used to anchor a ceramic thermal barrier layer directly on the substrate, eliminating the need for a special bonding layer to be interposed between the substrate and the thermal barrier layer. In its broadest scope, the superalloy is formed essentially of, as specified in weight percent: 3 to 12 Cr, 3 to 10 W, 6 to 12 Ta, 4 to 7 Al, 0 to 15 Co, 0 to 3 Mo, 0 to 15 Re, 0 to 0.0020 B, 0 to 0.045 C, 0 to 0.8 Hf, 0 to 2 Nb, 0 to 1 V, 0 to 0.01 Zr, 0 to 0.07 Ti, 0 to 10 of the noble metals, 0 to 0.1 of the rare earth metals including Sc and Y, balance Ni.
[0007] U.S. Pat. No. 5,087,477 to Giggins, Jr., et al. shows a method for placing a ceramic thermal barrier layer on a gas turbine component by a physical vapor deposition process including evaporating compounds forming the thermal barrier layer with an electron beam and establishing an atmosphere having a controlled content of oxygen at the component to receive the thermal barrier layer.
[0008] U.S. Pat. No. 5,484,263 to B. A. Nagaraj et al. shows a metal article having a heat shield including: a barrier layer on a surface of the article and a reflective layer on the barrier layer. The reflective layer being formed from a material which is selected from the group formed of the noble metals, noble metal alloys and aluminum. The barrier layer may be an oxide or a nitride.
[0009] European Patent Application 0 446 988 A1 to V. Andoncecchi et al. shows a process for forming a silicon carbide coating on a nickel-based superalloy, including nitriding pretreatment of the superalloy or deposition of a film of titanium nitride on the superalloy by reactive sputtering. Thereafter a thin film of titanium nitride is being deposed using vapor-phase chemical deposition. After this the nickel-based superalloys annealed in a nitrogen and hydrogen atmosphere and a silicon carbide layer is placed using vapor-phase chemical deposition. With this process a coating is obtained wherein between a ceramic layer containing silicion carbide or silicion nitride and a superalloy an intermediate layer containing titanium nitride is being interposed.
[0010] European Patent Application 0 688 889 A1 to P. Broutin et al. shows a process for passivating the surface of a metallic article formed of a nickel-based superalloy. This metallic article is a stove-pipe or the like. On the substrate formed of the nickel-based superalloy a protective layer is applied containing silicion carbide or silicion nitride. Between the ceramic protective layer and the substrate an intermediate layer formed of aluminum nitride or titan aluminum nitride is interposed. The intermediate layer has a thickness of 0.15 to 5 ฮผm which is less than a thickness of the protective layer.
[0011] U.S. Pat. Nos. 5,154,885; 5,268,238; 5,273,712; and 5,401,307, all to Czech et al. disclose advanced coating systems for gas turbine components including protective coatings of MCrAlY alloys. The MCrAlY alloys disclosed have carefully balanced compositions to give exceptionally good resistance to corrosion and oxidation as well as an exceptionally good compatibility to the superalloys used for the substrates. The basis of the MCrAlY alloys is formed by nickel and/or cobalt. Additions of further elements, in particular silicon and rhenium, are also discussed. Rhenium in particular is shown to be a very advantageous additive. All MCrAlY alloys shown are also very suitable as bonding layers for anchoring thermal barrier layers, particularly in the context of the invention disclosed hereinbelow.
[0012] The aforementioned U.S. Pat. No. 5,401,307 also contains a survey over superalloys which are considered useful for forming gas turbine components that are subject to high mechanical and thermal loads during operation. Particularly, four classes of superalloys are given. The respective superalloys are formed essentially of, as specified in percent by weight:
[0013] 1. 0.03 to 0.05 C, 18 to 19 Cr, 12 to 15 Co, 3 to 6 Mo, 1 to 1.5 W, 2 to 2.5 Al, 3 to 5 Ti, optional minor additions of Ta, Nb, B and/or Zr, balance Ni. These alloys are brought into shape by forging; examples are specified as Udimet 520 or Udimet 720 by usual standard.
[0014] 2. 0.1 to 0.15 C, 18 to 22 Cr, 18 to 19 Co, 0 to 2 W, 0 to 4 Mo, 0 to 1.5 Ta, 0 to 1 Nb, 1 to 3 Al, 2 to 4 Ti, 0 to 0.75 Hf, optional minor additions of B and/or Zr, balance Ni. These alloys are cast into shape; examples are GTD 222, IN 939, IN 6203 DS and Udimet 500.
[0015] 3. 0.07 to 0.1 C, 12 to 16 Cr, 8 to 10 Co, 1.5 to 2 Mo, 2.5 to 4 W, 1.5 to 5 Ta, 0 to 1 Nb, 3 to 4 Al, 3.5 to 5 Ti, 0 to 0.1 Zr, 0 to 1 Hf, an optional minor addition of B, balance Ni. These alloys are cast into shape; examples are IN 738 LC, GTD 111, IN 792 and PWA 1483 SX.
[0016] 4. 0.2 to 0.7 C, 24 to 30 Cr, 10 to 11 Ni, 7 to 8 W, 0 to 4Ta, 0 to 0.3 Al, 0 to 0.3 Ti, 0 to 0.6 Zr, an optional minor addition of B, balance cobalt. These alloys are cast into shape; examples are FSX 414, X 45, ECY 768 and MAR-M-509.
[0017] A standard practice in placing a thermal barrier coating on a substrate of an article of manufacture includes developing an oxide layer on the article, either by placing a suitable bonding layer on the article which develops the oxide layer on its surface under oxidizing conditions or by selecting a material for the article which is itself capable of developing an oxide layer on its surface. That oxide layer is then used to anchor the thermal barrier layer placed on it subsequently.
[0018] Under thermal load, diffusion processes will occur within the article. In particular, diffusion active chemical elements like hafnium, titanium, tungsten and silicon which form constituents of most superalloys used for the articles considered may penetrate the oxide layer and eventually migrate into the thermal barrier layer. The diffusion active chemical elements may cause damage to the thermal barrier layer by modifying and eventually worsening its essential properties. That applies in particular to a thermal barrier layer made from a zirconia compound like partly stabilized zirconia, since almost all zirconia compounds must rely on certain ingredients to define and stabilize their particular properties. The action of such ingredients is likely to be imparted by chemical elements migrating into a compound, be it by diffusion or otherwise. Likewise, the anchoring property of the oxide layer may be decreased partly or wholly by diffusion active chemical elements penetrating it.
[0019] In order to assure that a protective coating system including a thermal barrier layer placed on a substrate containing diffusion active chemical elements keeps its essential properties over a time period as long as may be desired, it is therefore material to prevent migration of diffusion active chemical elements.
[0020] Another relevant aspect in this context is the relatively poor thermal conductivity of alumina which can cause a hot zone to be created at the oxide layer in cooperation with heat reflection effects. Such a hot zone will cause high internal stresses to develop therewithin. These stresses may pertain considerably to a failure of a protective coating system including a thermal barrier layer on such an anchoring layer due to spallation which occurs within the anchoring layer or at an interface between the thermal barrier layer and the anchoring layer. In order to ensure a long life for the protective coating system and keep the oxidation of the bonding layer particularly low, care must be taken to transfer all the heat through the thermal barrier layer to the substrate and a cooling system which may be provided therein.
[0021] These aspects have, however, not yet received considerable attention by those working in the field. Heretofore, only an oxide layer has been given consideration to anchor a thermal barrier layer on a superalloy substrate regardless of its transmission of diffusing chemical elements to the thermal barrier layer and its poor thermal conductivity.
SUMMARY OF THE INVENTION
[0022] It is accordingly an object of the invention to provide a method of manufacturing an article with a protective coating system including an improved anchoring layer, which overcomes the hereinafore-mentioned disadvantages of the heretofore-known products and methods of this general type and which keep to a minimum or prevent the transmission of diffusing elements through an anchoring layer to a thermal barrier layer and allow for sufficient heat transmission through the anchoring layer.
[0023] With the foregoing and other objects in view there is provided, in accordance with the invention, an article of manufacture, including: a substrate formed of a nickel or cobalt-based superalloy; an anchoring layer placed on the substrate, the anchoring layer including a nitride compound; and a ceramic coating placed on the anchoring layer. Between the substrate and the anchoring layer there can be interposed a bonding layer.
[0024] A basic feature of the invention resides in replacing the oxide layer which has formed the anchoring layer within the protective coating system by an anchoring layer including a nitride compound, particularly aluminum nitride. Thereby, the relatively high thermal conductivity of aluminum nitride, which amounts up to 140 W/mK as opposed to a value between 30 W/mK at room temperature and 7.6 W/mK at 1000ยฐ C. for alumina, as well as the relatively low ion transmission property of aluminum nitride are utilized to improve the relevant parameters of the anchoring layer. Particularly, the nitride compound is formed essentially of aluminum nitride.
[0025] The invention further relates to an article of manufacture, including a substrate formed of a nickel or cobalt-based superalloy, an anchoring layer disposed on the substrate, the anchoring layer including a nitride compound, and a ceramic coating disposed on the anchoring layer, whereby the nitride compound includes chromium nitride.
[0026] In accordance with an added embodiment of the invention, the anchoring layer is formed essentially of the nitride compound. In this context, it should be noted that aluminum in particular will preferably react with oxygen, if both nitrogen and oxygen are present. If oxygen and nitrogen are present in proportions similar to their proportions in air, it must be expected that only reactions between aluminum and oxygen will occur. This requires particular precautions to suppress the presence of oxygen if aluminum nitride is to be prepared by some reaction between elementary aluminum and nitrogen, particularly in the context of a reactive deposition process. Likewise, it must be expected that a compound formed by reacting nitrogen with aluminum contains a certain amount of compounds formed with oxygen, such as ordinary alumina. Such oxygen-containing compounds may eventually form inclusions within a matrix of aluminum nitride. In the present context, aluminum is a metal which has particular importance; however, the above consideration will apply to other metals as well, particularly to chromium.
[0027] In accordance with an additional embodiment of the invention, the article includes a diffusion active chemical element covered by the anchoring layer. The diffusion active chemical element is preferably an element selected from the group formed of hafnium, titanium, tungsten and silicon. In particular, the diffusion active element is contained in the substrate or a bonding layer disposed thereon.
[0028] Diffusion of the elements mentioned in the preceding paragraph is not considerably inhibited by ordinary alumina. Aluminum nitride, however, can act as an efficient diffusion barrier for these elements, since the nitrogen ions present within the aluminum nitride efficiently hinder a migration of atoms through the material. An additional advantage in this context is a reduced transmission of oxygen from the outside of the article and through the anchoring layer, since the nitrogen ions within the nitride compound also hinder the migration of oxygen ions. Thereby, it must be expected that oxidation of the material whereon the anchoring layer is disposed, namely a bonding layer or a substrate with special properties as explained, will occur at a rate which will be considerably lower than a rate of oxidation which must be expected with a usual anchoring layer in the form of oxides. In summary, both a depletion of a substrate or a bonding layer of diffusion active elements as well as oxidation of the substrate or bonding layer are inhibited, and the lifetime of the article with the protective coating system will be greatly enhanced.
[0029] In accordance with a further embodiment of the invention, the ceramic coating includes ZrO 2 . In a further development, the ceramic coating is formed essentially of ZrO 2 and a stabilizer selected from the group formed of Y 2 O 3 , CeO 2 , LaO, CaO, Yb 2 O 3 and MgO.
[0030] In a preferable embodiment, the anchoring layer has a thickness of less than 1 ฮผm. In particular, this thickness is between 0.1 gm and 0.4 Am. In any event, the thickness of the anchoring layer is selected by taking into account the relatively small coefficient of thermal extension of aluminum nitride which is 3.6ร10 โ6 /K at room temperature to 5.6ร10 โ6 /K at 1000ยฐ C., to be compared with 6.2ร10 โ6 /K at room temperature to 8.6ร10 โ6 /K at 1000ยฐ C. for alumina. In order to keep the mechanical stresses low in the anchoring layer, the thicknesses as mentioned are considered to be particularly effective.
[0031] In accordance with again a further embodiment of the invention, the article is provided with a bonding layer interposed between the substrate and the anchoring layer.
[0032] In preferred embodiments, the bonding layer is formed of a metal aluminide, or it is formed of an MCrAlY alloy.
[0033] In accordance with a particularly preferred embodiment of the invention, the ceramic coating has a columnar grained structure and the anchoring layer has a surface whereon the ceramic coating is placed, the surface having a surface roughness R a less than 5 ฮผm. Preferably, the surface roughness R a is less than 2 ฮผm. Particularly, the anchoring layer has a thickness more than 0.1 ฮผm. The parameter R a characterizes a surface roughness in terms of an arithmetical mean deviation of the surface from a smooth mean profile along a measuring line of suitable length and form defined on the surface. Since R a is thus an integral value, it is evident that it will be virtually independent of particular properties of the measuring line, provided that it is long enough to avoid influences of statistical fluctuations yet short enough to retain its significance for the surface under consideration.
[0034] The article as embodied according to the preceding paragraph features a ceramic coating which is of a columnar grained structure, which is expected to have superior mechanical properties. A columnar grained structure has crystallites in the form of small columns disposed one beside the other on the anchoring layer, thus allowing for almost free expansion of the substrate under thermal stress, assuring a particularly high lifetime for the protective coating system. Within that embodiment, bonding between the ceramic coating and the thermal barrier layer must be effected by a solid-state chemical bond. That bond is provided preferably by polishing the article within the course of placing (deposing, adhering) the different layers to achieve a surface roughness as specified.
[0035] In accordance with another preferred embodiment of the invention, the ceramic coating has an equiaxial structure and the anchoring layer has a surface whereon the ceramic coating is placed, the surface having a surface roughness R z , greater than 35 ฮผm and a surface roughness Ra greater than 6 ฮผm, particularly a surface roughness R z , between 50 ฮผm and 70 ฮผm and a surface roughness between R a , between 9 ฮผm and 14 ฮผm. The parameter R a has already been explained. The parameter R z characterizes a surface roughness in terms of an average peak-to-valley height of the surface, where peak-to-valley heights of five individual measuring lines defined on the surface under consideration are averaged. R z is thus a mean value for a maximum distance between a peak projecting out of the body having the surface and a valley projecting into the body. Both R a and R z are standard parameters, known in the art and defined as such in German norm DIN 4762, for example.
[0036] In the embodiment specified in the preceding paragraph, the ceramic coating has a particularly simple structure which allows for a particularly simple depositing process. As opposed to a ceramic coating with a columnar grained structure which must generally be applied by a special PVD process, a ceramic coating with an equiaxial structure can be placed by simple atmospheric plasma spraying. A ceramic coating of this type may not have the superior lifetime characteristic of a columnar grained ceramic coating, but it can be deposited in a particularly cheap way which makes it, within suitable compromises, also particularly useful. In this context, the anchoring layer, as well as the substrate itself or the bonding layer if present, can be left with a considerable surface roughness which may be obtained by simply applying the bonding layer by a process like vacuum plasma spraying and a-voiding any surface smoothing treatment.
[0037] The fairly rough surface of the anchoring layer will then retain the ceramic coating not only by a chemical bond, but also by mechanical clamping.
[0038] In accordance with yet an added embodiment of the invention the substrate, the bonding layer (if present), the anchoring layer and the ceramic coating form a gas turbine component. In particular, the gas turbine component is a gas turbine airfoil component including a mounting portion and an airfoil portion, the mounting portion being adapted to fixedly hold the component in operation and the airfoil portion being adapted to be exposed to a gas stream streaming along the component in operation, the anchoring layer and the ceramic layer placed on the airfoil portion.
[0039] With the above-mentioned and other objects in view, there is also provided, in accordance with the invention, a method of applying a ceramic coating to an article of manufacture having a substrate formed of a nickel or cobalt-based superalloy. Particularly, the substrate may have a bonding layer placed thereon, as described hereinabove. The method includes the following steps: placing (deposing) an anchoring layer including a nitride compound on a substrate formed of a nickel or cobalt-based superalloy; and placing a ceramic coating on the anchoring layer.
[0040] In accordance with an additional mode of the invention, the step of placing the anchoring layer is performed by physical vapor deposition. Preferably, a physical vapor deposition process including sputtering or electron beam evaporation is used.
[0041] In accordance with another mode of the invention, the step of placing the anchoring layer includes:
[0042] establishing an atmosphere containing nitrogen around the layer,
[0043] creating the anchoring layer by subjecting the layer and the atmosphere to an elevated temperature;
[0044] placing at least one metal to a surface of the substrate- and
[0045] reacting the metal with the nitrogen to form the nitride compound.
[0046] In accordance with a further mode of the invention, a plasma containing ionized nitrogen is formed around the substrate. Thereby reactions between nitrogen and metal compounds to form the desired nitride compound are facilitated. In accordance with an additional mode of the invention, the metal is placed on the substrate by coating the substrate with the metal. Alternatively, the metal can be placed on the substrate by diffusing the metal out of the substrate or out of a bonding layer priorly placed on the substrate.
[0047] In accordance with yet another mode of the invention, the metal is selected from the group formed of aluminum and chromium.
[0048] In accordance with a particularly preferred mode of the invention, the surface is prepared on the substrate, eventually on a bonding layer placed on the substrate, the surface having a surface roughness R a , less than 2 ฮผm, prior to placing the anchoring layer on the surface, and the ceramic layer is placed with a columnar grained structure. In this context, the surface is prepared preferably by polishing. Also preferably, a bonding layer is placed on the substrate, and the surface is prepared on the bonding layer. With further preference, the ceramic layer in this context is placed by physical vapor deposition, particularly to form a ceramic layer having a columnar grained structure. The formation of such structure may require that some kind of epitaxial growth is effected when placing the ceramic coating, to ensure that the desired columns of ceramic material are obtained.
[0049] In accordance with an alternative preferred mode of the invention, the surface is prepared on the substrate, the surface having a surface roughness R z between 40 ฮผm and 50 ฮผm, prior to placing the anchoring layer on the surface, and the ceramic layer is placed with an equiaxial structure. Particularly, the surface is prepared by placing a bonding layer on the substrate by vacuum plasma spraying, establishing the surface on the bonding layer and leaving the surface without smoothing treatment. In this context, the ceramic layer may be placed by atmospheric plasma spraying to obtain an equiaxial structure.
[0050] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0051] Although the invention is illustrated and described herein as embodied in a method of manufacturing an article with a protective coating system including an improved anchoring layer, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0052] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of the specific embodiment when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIGS. 1 to 3 are fragmentary, diagrammatic, cross-sectional views of substrates having a respective protective coating system incorporating a ceramic coating adhered thereon;
[0054] [0054]FIG. 4 is a perspective view of a gas turbine airfoil component including the substrate and protective coating system shown in FIG. 1;
[0055] [0055]FIG. 5 is a perspective view of a gas turbine heat shield component; and
[0056] [0056]FIG. 6 is a perspective view of another gas turbine heat shield component.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0057] Referring now to the figures of the drawing in detail and first, particularly, to FIGS. 1 to 3 thereof, there is seen a respective substrate 1 of an article of manufacture, in particular a gas turbine component, which in operation is subject to heavy thermal load and concurrently to corrosive and erosive attack. The substrate 1 is formed of a material which is suitable to provide strength and structural stability when subjected to a heavy thermal load- and eventually an additional mechanical load by severe forces like centrifugal forces. A material which is widely recognized and employed for such a purpose in a gas turbine engine is a nickel or cobalt-based superalloy. Particularly preferred are a nickel-based superalloy which is specified as PWA 1483 SX and a cobalt-based superalloy which is specified as MAR-M-509, both specifications by usual standard.
[0058] The composition of the superalloy PWA 1483 SX specified in terms of parts per weight, is as follows: Carbon 0.07%; chromium 12.2%; cobalt 9.0%; molybdenum 1.9%; tungsten 3.8%; tantalum 5.0%; aluminum 3.6%; titanium 4.2%; boron 0.0001%; zirconium 0.002%; balance nickel.
[0059] The composition of the superalloy MAR-M-509, specified in terms of parts per weight, is as follows: Carbon 0.65%-chromium 24.5%; nickel 11%; tungsten 7.5%; tantalum 4.0%; titanium 0.3%; boron 0.010%; zirconium 0.60%; balance cobalt.
[0060] The compositions are specified by way of example. In any case, the alloys should be made in accordance with the usual specifications and the general knowledge of those skilled in the art.
[0061] In order to limit the thermal load imposed on the substratel, a ceramic coating or thermal barrier layer 4 is placed thereon, formed essentially of a stabilized or partly stabilized zirconia. The thermal barrier layer 4 is anchored to the substrate 1 by means of an anchoring layer 3 . According to FIGS. 1 and 2, the anchoring layer 3 is placed on a bonding layer 2 which has been placed on the substrate 1 , which in these cases is preferably made from the superalloy PWA 1483 SX. The bonding layer 2 is formed of an MCrAlY alloy and preferably of an MCrAlY alloy as disclosed in one of U.S. Pat. Nos. 5,154,885; 5,268,238; 5,273,712; and 5,401,307. The bonding layer 2 has certain functions in common with a bonding layer as known from the state of the art and in particular has a tight bond to the substrata 1 . The anchoring layer 5 serves as an anchor for the thermal barrier layer 4 .
[0062] [0062]FIG. 1 shows an embodiment of the invention where the ceramic coating 4 is made from a ceramic with no particular microscopic orientation, namely a ceramic with an equiaxial structure. Such ceramic is easily and cheaply applied by atmospheric plasma spraying. The use of such ceramic may involve some compromises relating to the lifetime which may be attainable for the article; however, as the application of the ceramic is done in a particularly cheap way, it can be tolerated that the ceramic must be replaced at relatively frequent intervals. In order to anchor such ceramic coating 4 on the anchoring layer 3 and the bonding layer 2 , it is preferred to prepare the bonding layer 2 and the anchoring layer 3 with a surface 5 whereon the ceramic is to be placed which is fairly rough, in particular as specified hereinabove. Thereby, the ceramic coating 4 will not only be bonded to the substrate by some kind of chemical bond provided by a solid-state chemical reaction, but also by mechanical clamping provided by the various structures on the surface 5 . As already mentioned, a desired roughness of the surface 5 can be provided by applying the bonding layer 2 by a process like vacuum plasma spraying and simply leaving the bonding layer without any smoothing treatment. Peening of the bonding layer with glass beads or the like may eventually be used to compress the bonding layer 2 and avoid any voids therein; such peening is not likely to substantially smoothen the bonding layer 2 and thus not regarded to be representative of a smoothing treatment.
[0063] [0063]FIG. 2 shows a different ceramic coating 4 , which is likely to feature indeed superior properties. According to FIG. 2, the ceramic coating 4 is provided as a columnar grained ceramic which must be applied by a sophisticated process like PVD. By such process, the ceramic coating will grow almost epitaxially on the substrate 1 , and a multiplicity of small columns, one beside the other on the surface 5 , will form. Since the ceramic coating 4 is formed of individual columns, it is not likely to spall or break as the protective coating system 2 , 3 , 4 and the substrate 1 are subjected to a thermal load. However, the ceramic coating according to FIG. 2 is likely to be much more expensive than the ceramic coating 4 according to FIG. 1. In order to apply a ceramic coating 4 as shown in FIG. 2, it is preferred to provide the surface 5 whereon the ceramic coating 4 is to be placed with fairly little roughness; it is indeed preferred to polish the bonding layer 2 , eventually even the substrate 1 as well, prior to application of the anchoring layer 3 . Preferred properties of the surface 5 and to be attained as explained have been specified hereinabove.
[0064] [0064]FIG. 2 shows also an oxide layer 6 between the anchoring layer 3 and the bonding layer 2 . In most cases this oxide layer 6 will be composed of alumina which has formed from aluminum diffusing out of the bonding layer 2 and oxygen penetrating through the ceramic coating 4 and the anchoring layer 3 . As the substrate 1 with its protective coating system is subjected to a hot oxidizing gas stream in operation in a gas turbine, a steady oxidation process at an interface between the anchoring layer 3 and the bonding layer 2 must be expected; accordingly, the oxide layer 6 is very likely to form and grow steadily, and a failure of the protective coating system must be expected after the oxide layer 6 has increased over a critical thickness. If the oxide layer 6 becomes too thick, it is likely to develop internal cracks and the like, which will ultimately lead to spalling. By providing the anchoring layer 3 in accordance with the invention, it is expected that transmission of oxygen through the anchoring layer is greatly reduced as compared to prior art anchoring layers, and thus a prolonged lifetime of the protective coating system is expected.
[0065] [0065]FIG. 3 shows another embodiment of the invention, where no bonding layer 2 as in FIGS. 1 and 2 is used. The anchoring layer 3 is placed directly on the substrate 1 , and the ceramic layer is placed on the anchoring layer 3 . Preferred embodiments of the ceramic layer 4 as shown in FIG. 1 and FIG. 2 may be used. As the anchoring layer 3 is placed immediately on the substrate 1 , it is of particular importance that a suitable material for the substrate 1 is selected. In particular, the cobalt-based superalloy MAR-M-509 has proved to be effective; an important feature in this respect is to use an alloy which is capable of developing a protective oxide layer on its surface under oxidizing treatment. FIG. 3 shows a feature which illustrates the capability of a nitride compound like aluminum nitride or chromium nitride to be bonded to an alloy. Namely, nitride inclusions 7 are formed within the substrate 1 below the anchoring layer 3 , demonstrating that nitrogen is capable to diffuse into the substrate 1 and provide for the desired bonding between the anchoring layer 3 and the substrate 1 . In fact, a mixing zone will be created where a more or less smooth transition from the anchoring layer 3 to the undistorted substrate 1 is provided and where nitride inclusions 7 may form with aluminum, chromium or other nitride-forming constituents of the material of the substrate 1 .
[0066] Referring now again to FIGS. 1 to 3 in common, it should be noted that due to the very high affinity of aluminum and even chromium to oxygen, it must be expected that not only aluminum nitride and/or chromium nitride will be formed if oxygen is present besides nitrogen, even if only in a minor amount. Accordingly, it must be expected, that the anchoring layer 3 formed as explained contains inclusions which are formed with oxygen and which may be composed of simple oxides or ternary compounds including at least one metal besides oxygen and nitrogen. It is preferred however to keep the oxygen content of the anchoring layer 3 as low as possible and to avoid a formation of such inclusions 7 as much as possible.
[0067] The drawing is not intended to show the thicknesses of the layers 2 , 3 , 4 and 6 to scale; the thickness of the anchoring layer 3 might in reality be very much less than the thickness of the bonding layer 2 , as specified hereinabove.
[0068] In any case, the anchoring layer 3 can be made by several methods, in particular by a physical vapor deposition process like electron beam PVD, sputter ion plating and cathodic arc-PVD, or by thermal treatment of a metal layer in a nitrogen-containing atmosphere. Such thermal treatment is in particular carried out at a temperature within a range between 700ยฐ C. and 1100ยฐ C. A nitrogen-containing atmosphere may also serve to provide the nitrogen for a PVD-process, which includes evaporating the required metal from a suitable source and adding the nitrogen from the atmosphere. As an alternative, the metal can be provided by diffusing it out of the substrate 1 or a bonding layer 2 applied thereto and reacting the metal with nitrogen as explained just before. In any case, the reactivity of the nitrogen can be increased by forming a nitrogen-containing plasma around the substrate 1 , as explained hereinabove.
[0069] [0069]FIG. 4 shows a complete gas turbine component 8 , namely a gas turbine airfoil component 8 , in particular a turbine blade. The component 8 has an airfoil portion 10 , which in operation forms an โactive partโ of the gas turbine engine, a mounting portion 9 , at which the component 8 is fixedly held in its place, and a sealing portion 11 , which forms a seal together with adjacent sealing portions of neighboring components to prevent an escape of a gas stream 12 flowing along the airfoil portion 10 during operation.
[0070] The section of FIG. 1 is taken along the line I-I in FIG. 2.
[0071] [0071]FIG. 5 shows another gas turbine component 13 , namely a gas turbine heat shield component 13 . This component 13 has a shielding portion 14 , which in operation forms an โactive partโ of the gas turbine engine, namely a hot gas channel thereof, and mounting portions 15 . In order to construct a mounting portion 15 , many options are known. For the sake of simplicity, the mounting portions 15 are shown in the form of rails 15 whereat the component 13 can be fixed. However, no claim is made that this structure is particularly effective.
[0072] [0072]FIG. 6 shows a preferred structure for a gas turbine heat shield component 13 . This gas turbine heat shield component 13 has a shielding portion 14 formed as a curved plate. For fastening, a hole 16 to be penetrated by a fastening bolt or the like is provided.
[0073] Referring again to FIG. 1, particular advantages of the novel combination of the anchoring layer 3 and the thermal barrier layer 4 can be summarized as follows: As the anchoring layer 3 has a high content of nitride compounds, it is indeed very suitable for anchoring a thermal barrier layer 4 . That thermal barrier layer 4 may expediently be deposited on the substrate 1 immediately after deposition of the anchoring layer 3 and in particular within the same apparatus and by using as much as possible installations which have been already in use for depositing the anchoring layer 3 . The combination of the anchoring layer 3 and the thermal barrier layer 4 thus made has all the advantages of such combinations known from the prior art and additionally features a substantially prolonged lifetime due to a reduced oxidation of layers of the article below the anchoring layer 3 , an improved heat transmission through the anchoring layer 3 and a good suppression of migration of diffusion active elements into the thermal barrier layer 4 .
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A method of placing a ceramic coating on an article of manufacture comprising a substrate formed of a nickel or cobalt-based superalloy, which includes the steps of placing a bonding layer on the substrate and placing an anchoring layer, which is chemically different from the bonding layer and comprises a nitride compound, on the bonding layer. The method further includes the step of placing the ceramic coating on the anchoring layer.
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TECHNICAL FIELD
The present invention relates to devices for dispersing and gathering liquids in soil, more particularly, to arch shaped plastic leaching chambers for use in dispersing sewage and storm waters.
BACKGROUND
In the last decade, molded plastic leaching chambers (also referred to as leaching conduits), sold under the registered U.S. trademark "Infiltrator", have met substantial commercial success. Examples of such type of chambers are shown in U.S. Pat. No. 4,759,661 to May and Nichols; and, in U.S. Pats. No. 5,017,041, No. 5,156,488 and 5,336,017 all to Nichols, all of which patents have an inventor and assignee in common herewith.
Generally, the commercial Infiltrator brand chambers and certain competitor products are arch shaped, have open bottoms, sloped perforated sides, and peak and valley corrugations running along the arch shape. Liquid introduced into the chamber disperses in the soil by passing through the open bottom and through the perforated sidewalls.
For economy of manufacture and distribution, typical chambers are identical, and nest readily for shipment. Chambers have opposing open ends adapted to enable one chamber to mate with other like chambers. Ends providing shiplap chamber joints strengthened by legs, tabs or other interlocks have been favored.
Typically, the molded chambers are placed end-to-end as an essentially straight string of units in a trench. Liquid flows through the chambers, from one to the next, by gravity. Thus, it is important that the units of a string of chambers will be placed in the earth so they have at most a very slight slope relative to the plane of the earth, from the first to the last, i.e., they must be "practially level". Thus, problems are presented when installations must be made on sloped land, such as a hillside, where the trench ought to follow a level contour line of the hill.
In the older designs of leaching chambers, for example in the type using spaced apart cast concrete galleries, the separate units can be put at angles to one another, and the non-parallel outlet and inlets of the galleries are connected by short lengths of pipe. The same approach can be used for the molded chambers. The trench in the soil is made in a jagged-curve, to follow the contour of the hillside and be practically level. Single chambers or short strings of chambers are fitted with end plates and connected as described just above. The disadvantage with this involves the use of endplates and pipe, which raises material and labor cost. And, longer trenches are needed to obtain the desired leaching area, presenting a problem on small lots.
One alternative for installing prior art molded chambers is to dig the trench straight and practically level. However, this can contravene good leaching practice since the trench necessarily becomes deep, and chambers are not placed near the surface of the earth where there is desirable oxygen transfer. In certain areas of the country, bedrock and ledge will make deep trenches infeasible. Another alternative is to provide an arch shape angle-adapter, or connector, interposing it between unaligned chambers. But, chamber ends must connect structurally, to best resist vertical loads during use. An adapter introduces the weakness of an additional joint or weakening point. And, having a separate component requires system installers to carry additional inventory.
Despite the continuing need, a better solution to the problem is required.
SUMMARY
An object of the invention is to provide a means for connecting molded leaching chambers in a way which enables them to be constructed as a curved string of chambers when desired. A further object is to provide a molded leaching chamber with an adaptation that enables curved strings to be constructed, but at the same time minimizes the disadvantages that attend having a separate adapter or connector.
In accord with one aspect of the invention, a leaching chamber has an arch shape cross section and opposing ends shaped to mate with the ends of other chambers; and, the terminus of at least one end of the chamber is angled with respect to the chamber longitudinal axis, to enable a string of chambers to be connected along the path of an approximate curve.
In accord with another aspect of the invention, the end of the chamber has a terminus with a first angle, and the end of the chamber can be severed from the chamber to provide a terminus having a second angle. For example, the original terminus angle may be less than 90 degrees, and upon severing, the chamber may have a new terminus angle of 90 degrees. Thus, when mated in original condition, the chambers will follow a curve; when mated after the end has been altered, chambers will follow a straight line.
A preferred chamber has an indicant fin running across the arch shape, to delineate the point at which the end may be detached from the chamber to create the new terminus; and, the indicant fin provides strengthening to the new terminus. A preferred first terminus angle is about 6 degrees from square. Preferably, the joint formed by mating chambers has a significant looseness of fit. The looseness of fit provides play, and an additional plus or minus angling, e.g., 3 degrees, from the basic alignment angle. Thus, in a preferred embodiment, the invention chambers can form strings of chambers where the angles between the longitudinal axes of adjacent connected chambers range from 3 degrees negative to 9 degrees positive.
The foregoing and other objects, features and advantages of the invention will become more apparent from the following description of the best mode of the invention and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the angle end of a leaching chamber.
FIG. 2 shows in top view the chamber of FIG. 1, together with an opposing end portion of a second like chamber, positioned to mate with the angled opposing end of the first chamber.
FIG. 3 is a perspective view of the right angle opposing end of the chamber of FIG. 1.
FIG. 4 is a off-centerline vertical cross section view of the angle end of the chambers shown in FIG. 2, showing how the left chamber will overlap the right one as they are mated.
FIG. 5 is an off-centerline vertical cross section through a portion of the chamber shown in FIG. 1, to show fins, including an indicant fin, running along the arch shape perpendicular to a lengthwise rib.
FIG. 6 is a top view of the first chamber shown in FIG. 2, to illustrate how the angle end may be removed at the indicant location.
FIG. 7 is a cross section through a portion of the angle end of a chamber showing an alternative indicant design.
FIG. 8 is a top view of two strings of chambers connected by a pipe, where the strings have different combinations of roughly curving and straight alignments.
FIG. 9 shows a section through the subarch of the chamber of FIG. 1, showing interior pockets which engage with a nub on a mating chamber, to hold the chamber joint together.
DESCRIPTION
The invention is described in terms of a gas-assisted injection molded high density polyethylene leaching chamber, generally in accord with the preferred chambers disclosed in the aforementioned patents to Nichols, as well as in U.S. Pat. No. 5,401,459 to James M. Nichols and Roy E. Moore, Jr., the disclosures of which are hereby incorporated by reference.
FIG. 1 shows the angled end 24 and part of a typical chamber 20 having an arch shape cross section with corrugations comprised of alternating peaks 28 and valleys 30, running across the arch. The sidewalls of the chamber peaks and valleys have horizontal slotted perforations 29. FIG. 2. shows the same chamber in top view, as it is about to be mated with the square end 34A of a like chamber 20A. Some of the detail at the end 24 which is shown in FIG. 1 has been omitted for clarity of illustration in FIG. 2.
FIG. 3 shows in more detail the end 34 of the chamber 20, which is identical to the end 34A of chamber 20A. Suffixes are used for the part numbers of chamber 20A and for chambers in other figures, to identify features on different chambers or embodiments which correspond with each other.
Referring to FIG. 3, chamber 20 has a flanged base 32, comprised of two spaced apart flat surfaces. It resists penetration into the earth from downward forces during use. Integral with the end 34 is a terminus which is square, or perpendicular, to the chamber primary longitudinal axis 44. By "terminus" is meant that portion at the extremity of a chamber which is adapted to mate with a like chamber to form a joint. Extending from the end 34 as part of the terminus are cantilever legs 36, which engage the end of a mated chamber and transfer loads to and from it.
Referring to FIG. 1 and 2, the centerline 17 of angled end 24 of chamber 20 is angled with respect to the primary longitudinal axis 44 of the main body, or major portion, of the chamber. A reference to "angled end" or an analogous reference in this description is a reference to an end having a terminus which is at an angle other than a right angle, or an end which has a longitudinal axis which is not parallel to the primary longitudinal axis of the chamber. The longer sidewall of the end 24 follows a slight curve. The terminus 38 of the end is inclined at an acute angle A to the plane 39 perpendicular to the chamber centerline 44.
The arch shape at the terminus of end 24 is slightly larger than that of the opposing chamber end 34, 34A, as is typical in the prior art. So, when chamber 20 is mated with chamber 20A, the terminus of end 34A of chamber 20A will be overlapped by the terminus of end 24 of chamber 20, forming a shiplap joint which prevents soil from entering the interiors of the chambers. The off-centerline vertical cross section of FIG. 4 shows how the chambers 20, 20A mate, with a length of overlap j, and how the legs 36A capture the overlapping chamber end 24. The shiplap or overlap feature may be omitted in some chamber joint designs, e.g, where a permeable fabric or other structure is overlaid the joint. Similarly, where there is minimal load, the legs may be omitted. The invention will be useful with all variety of open-end chamber designs, including those where opposing ends are identical to each other.
Reffering again to FIG. 1, at the top of the chamber end 24 is subarch 31 which, when the chamber is fitted with a suitable endplate closure having a mating semi-circular opening, enables connection of a pipe bringing liquid to the chamber, as known in the prior art. A preferred endplate slips into and is fastened in the opening, as with screws or detents. Other endplate designs may be used. Of course the subarch may be eliminated, such as when liquid is delivered through the top of the chamber or lower on the endplate.
In FIG. 2 mating chamber 20A is shown lying at an angle to the primary centerline 44 of chamber 20, so it aligns with the centerline 17 of end 24, to thereby be positioned for joining to it. Thus, when mated, the primary centerline 44A of chamber 20A forms an an oblique angle C, less than 180 degrees, with the primary centerline 44 of chamber 20, as measured in the horizontal or base plane of the chambers. For convenience, chamber alignment is defined herein according to angle B, the alignment angle. See FIG. 2. Angle B is the reciprocal of the angle C, i.e., 180-C=B. (For emphasis of illustration, the angles A, B, etc., are exaggerated somewhat in the Figures.)
In the first instance, the basic alignment angle B between the chamber centerlines is equal to the angle A which the terminus makes with the plane perpendicular to the primary longitudinal axis. However, the fit between the mating arch shape joint ends of the two chambers is made such as to provide sufficient clearance or play, so that when the chambers are fully mated, chamber 20A can rotate or angle somewhat about its point of mating with chamber 20. Thus, the centerline 44A of chamber 20A may be made to lie anywhere between the lines c and d.
The plus and minus angle represented by lines c and d relative to the basic alignment angle B will be limited according to the amount of overlap length j designed into the joint and length of legs 36, since the chambers must still engage sufficiently along the arch of the joint to enable those features to still serve their purpose. Of course, there was imperfect tightness of the lapping joint formed between prior art chambers, due to design and manufacturing tolerances, with the flexibility of the plastic chamber material. As a result, in prior art chambers there is a slight but unintended capability for plus or minus angular adjustment. However, such adjustment is typically of the order of substantially less than one degree, and is not significant in the context of the present invention's designed significant plus or minus angular adjustment.
The terminus of chamber 20 has two features which facilitate the significant plus or minus adjustment of the invention. First, the base 32 of chamber 20 has small cutouts or notches 37 at the corners of its terminus end, as seen in FIG. 2. These enable the mating chamber to rotate in the plus or minus angle range. Otherwise the base flanges would interfere with each other. Alternately, one or both of the mating chamber bases may be stepped at the corners, so the corner of one chamber may overlap the adjacent corner of the mating chamber, to achieve the same result. When a chamber is severed to form a new terminus, as described below, the base flanges at the new terminus will likewise be provided similar base features, either by design or by the installer removing a portion of the new terminus base flange.
Second, the typical prior art locking tab at the top of the subarch 31, which keeps the joint between chambers from separating, is changed. The change is necessary beacause, as one chamber is rotated within the plus or minus angle, the joint opens at the center point of the arch. FIG. 9 shows the changed features of the locking tab, through a centerline cross section of the end of the chamber 20, through the subarch 31. There is a pocket 83, into which fits nub 89 (See FIG. 3) on the subarch of the end 34 of the mating chamber, which is shown in phantom. The chambers are shown joined with zero plus or minus angling, and it is seen there is a clearance space 91. Thus, the space enables chambers to draw apart slightly, to permit taking advantage of the plus or minus angle feature. At the same time the locking system ensures they will not disengage from each other. When the angle end of chamber 20 is cut along plane 39, as described below, the pocket 85 becomes useful in substitution of the pocket 83.
Preferably, the the basic alignment angle B is about 6 degrees; and, the lines c and d will lie about 3 degrees, plus and minus, from the basic angle B. Thus, the total range of adjustment for such a chamber in its original fabricated condition will be 3-9 degrees.
FIG. 5 shows a fragment of the off-center vertical cross section, with reference to FIG. 1. There are two fins 74, 75 running along the curve of the arch. They intersect the lengthwise stiffening rib 76 which is positioned along the arch so it does not intefere with the legs 36 of a mating chamber. There is a further transverse stiffening fin 72 at the outer edge of terminus 38. As shown in FIG. 1, there are additional small lengthwise stiffening members on the exterior. There may be still other stiffening ribs running lengthwise and transversely on the chamber interior, as taught by the prior art. Preferably, the chamber is made by gas assisted injection molding. Thus, the fins may desirably be hollow and the ribs may be of stepped cross section with hollow bases, as described in Pat. No. 5,401,459.
The angle end of the chamber 20 is configured so that the angle end can be removed, to form a square end chamber. This is accomplished by cutting along the chamber outboard of, and parallel to, the inner fin 74, with a saw or other instrument, as illustrated by the top view in FIG. 6 and phantom line 77 in FIG. 5. The terminus of modified end 42 shown in FIG. 6 is substantially perpendicular to the centerline 44. The chamber is configured so that after the end 24 is detached, the resultant modified or new end is suitable for mating with another like chamber in the same way as was the original. It presents to a mating chamber, e.g. chamber 20A, a configuration having suitable shape and features to achieve, for example, good mating fit with the aforementioned plus or minus play, shiplapping all along, including at the subarch, and so forth. Of course, within the invention, the new terminus can have any different angle from the angle of the first end.
Thus, it will be appreciated that the fin 74 is an indicant. It demarcates where the angle end is removable. At the same time it functions as a strengthening fin at the outer edge, as does fin 72 in the original end, after the chamber is cut.
In a preferred embodiment, the chamber in original configuration has end design enabling the forming of a mating chamber pair, with chamber longitudinal axes angling within the range of 3-9 degrees. And, after alteration by cutting at the indicant, a chamber pair is formed with longitudinal axes angling within the range plus 3 degrees to minus 3 degrees from parallel or straight. Thus, the total angle range which the exemplary invention chamber enables at a joint with another chamber, when considering it in both its original condition and modified condition, is from minus 3 degrees to plus 9 degrees. Other basic end terminus angles and other degrees of plus or minus from the basic angle or modified end angle may be chosen, as desired.
Thus, since the invention chambers can be converted as described, and one chamber can be used for both curved and straight strings, problems of inventory control with unconvertible units are avoided. The indicant, such as fin 74, provides the craftsman installing a chamber with a means for accurately and efficiently converting an angle end unit into a square end chamber. Other design of indicants, positive and negative relative to the chamber wall surface, may be used. For instance, two spaced apart fins 82 with a cutting groove 80 therebetween are shown in FIG. 7.
It will be understood that, before a chamber end is removed, an indicant will be in part longitudinally spaced away from the terminus. That is, it will be very close to, or at, the terminus on the chamber side where the end sidewall length is shortest, and further spaced apart from the terminus on the opposide side of the chamber. See FIG. 2. Obviously, it may also be entirely displaced from the terminus, toward the center of the chamber length.
The preferred embodiment comprises a chamber with an angled terminus at one end, severable to form a square end chamber. Within the scope of the invention the chamber may be made originally with a perpendicular terminus, severable to an angled terminus. Similarly, while in the preferred mode the chamber has one perpendicular end and one severable angled end, within the scope of invention both ends may be made angled or severable to angles.
Flexible combinations of roughly curved and straight strings can be constructed. A string is minimally comprised of two chambers. FIG. 8 shows in top view two connected strings of chambers. At the left, a string subset of four 6 degree angle end chambers 50 is mated with a bias in the joint fit, so that successive axes 54 of the chambers are at 9 degrees to each other. Liquid to be dispersed enters through pipe 52, connected to an end plate 53 of the first chamber. For a typical commercial chamber of about 75 inch length, and an end configured for an angle connection capability of 3-9 degrees, the nominal radius R of curvature may be between 40 and 120 feet. To conveniently reverse the direction of the curve and to make an s-curve, the last chamber in the first string is closed by endplate 8. A short length of pipe 60 connects the plate 58 to the end plate 59 of a second string of chambers 62 at the right of the Figure. The 3+ chambers of the second string subset are laid in the trench with their angle ends facing oppositely to those of the first string. The first two chambers 62 follow a reverse curve arc of two chambers length. The second chamber 62 has its angle end cut away, whereby the next adjacent chamber 63 aligns with it and the string continues in a straight direction.
As will be appreciated, when a curve has been referred to herein, the term applies to a rough curve, given that the chambers are straight and not bendable. Similarly, when chambers are said to be aligned in a straight line, normal random variation from a perfectly straight line is expectable due to the play at the joint.
Within the generality of invention a chamber may have both ends angled the same or differently; the chambers may not have the strengthening corrugations which are preferred; and in a string of chambers, a mating chamber connected to an invention chamber need not be totally identical to it, so long as the mating chamber has a suitable end for joining. In fact, it is within contemplation that invention chambers will be used with prior art chambers having both ends square. Although only the preferred embodiment with some alternatives have been described, it will be understood that further changes in form and detail may be made without departing from the spirit and scope of the claimed invention.
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A leaching chamber for gathering and dispersing liquids in soil has an end with an angled terminus, so that chambers may be connected as a string in a rough curve. An angled chamber end is severable from the chamber at an indicant, to convert the chamber to one having a different angled end, e.g., a square end. Intentional looseness of fit at the joint enables further angular adjustment. Thus, a combination of chambers with original and severed ends, having a basic 6 degree end angle and 3 degree of looseness, can form a chamber string where the alignment angles between adjacent chamber axes range from minus 3 to plus 9 degrees. Such leaching chamber strings may be installed in practically level trenches which follow the contour of a hillside.
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TECHNICAL FIELD
[0001] The disclosure relates to the field of mobile communication technology, and in particular to a method and device for managing security of information in a mobile terminal, as well as a mobile terminal.
BACKGROUND
[0002] With wide spread of mobile terminals, information stored in a mobile terminal of a user faces a growing security problem. When a mobile terminal is out of control of its user within a short period of time, such as when the user leaves the mobile terminal in an office or a hotel, or at home, or loses the mobile terminal, if information on contacts, short messages, call records stored in the mobile terminal relates to user privacy, then chances of the mobile terminal being used by someone else will pose a serious potential threat to security of the user information in the mobile terminal.
[0003] A corresponding solution has been proposed in existing art to secure information in a mobile terminal. For example, contacts of a mobile terminal user are classified as general contacts and private contacts; and the general contacts and the private contacts are stored separately. When a private contact calls or sends a short message, information displayed on an interface of a mobile terminal is hidden or ciphered. Alternatively, based on a preset mode of displaying a contact, information on a general contact is displayed as plaintext, and information on a private contact is displayed in cipher.
[0004] With the existing art, information in a mobile terminal is secured by hiding or ciphering information displayed on an interface of a mobile terminal. However, when a user loses control over a mobile terminal within a short period of time, an existing method cannot stop someone else from connecting the mobile terminal to a computer via a Universal Serial Bus (USB) and stealing the information stored in the mobile terminal, such as by connecting the mobile terminal to a computer via a USB, and copying an information storing database file in the mobile terminal to the computer, and then to an unauthorized mobile terminal. Then, information on contacts, short messages, call records and memos stored in the mobile terminal of the user may be identified and displayed normally by the unauthorized mobile terminal. In particular, there will be a higher probability of successfully stealing information in one mobile terminal with another mobile terminal of the same brand and the same model. In addition, if a mobile terminal of a user is connected to a computer via a USB, then someone other than the user may acquire information on contacts, short messages, call records and memos stored in the mobile terminal easily using a PC (personal computer) side software of the mobile terminal.
SUMMARY
[0005] In view of this, it is desired that embodiments of the disclosure provide a method and device for managing security of information in a mobile terminal, as well as a mobile terminal, capable of effectively stopping someone, other than a user of a mobile terminal, from connecting the mobile terminal to a computer through a USB and stealing user information in the mobile terminal.
[0006] To this end, a technical solution of the disclosure is implemented as follows.
[0007] The disclosure provides a method for managing security of information in a mobile terminal, including steps of:
[0008] in creating and initializing a text file, writing first mobile terminal identifier (ID) information in a starting part of the text file; and in storing information, ciphering information to be stored, writing the ciphered information in the text file, and storing the text file; in reading the first mobile terminal ID information and the stored information, loading the first mobile terminal ID information and the ciphered information into a memory; and determining a mode of displaying text information; and in displaying the stored information, when a mode of displaying text information as plaintext is determined, authenticating, according to the first mobile terminal ID information, an authorization for decipherment of the ciphered information loaded in the memory, and when the authorization for decipherment is authenticated, deciphering the ciphered information loaded in the memory and displaying the deciphered information as plaintext.
[0009] In an embodiment, the first mobile terminal ID information and the stored information may be read by: reading the first mobile terminal ID information by reading the starting part of the text file of a length of the first mobile terminal ID information, and reading the stored information in the text file starting from an offset point, wherein a length between a starting point of the text file and the offset point equals the length of the first mobile terminal ID information.
[0010] In an embodiment, the method may further include a step of: when a mode of displaying text information in cipher is determined and/or the authorization for decipherment is not authenticated, displaying ciphertext by
[0011] on a display interface of a second mobile terminal, displaying, in cipher, the information loaded in the memory while disabling a function of information creation, modification and deletion.
[0012] In an embodiment, the method may further include a step of: providing a user with an interface for setting a mode of displaying text information, via which the user may set a mode of displaying text information,
[0013] wherein the mode of displaying text information may include the mode of displaying text information as plaintext and a mode of displaying text information in cipher.
[0014] In an embodiment, the first mobile terminal ID information may be feature information uniquely identifying a first mobile terminal, and may be:
[0015] an Electronic Serial Number (ESN), a Mobile Equipment Identifier (MEID), or a unique identifier of the first mobile terminal set by a mobile terminal manufacturer;
[0016] or may be: a ciphered ID obtained by converting an ESN, a MEID, or a unique identifier of the first mobile terminal set by a mobile terminal manufacturer using a ciphering algorithm.
[0017] In an embodiment, the step of authenticating, according to the first mobile terminal ID information, an authorization for decipherment may be: reading, by a second mobile terminal, the first mobile terminal ID information written in the starting part of the text file when the text file is created and initialized; reading information on an ID of the second mobile terminal; comparing the information on the ID of the second mobile terminal to the first mobile terminal ID information; and determining that the authorization for decipherment is authenticated when the information on the ID of the second mobile terminal is identical to the first mobile terminal ID information; or determining that the authorization for decipherment is not authenticated when the information on the ID of the second mobile terminal is not identical to the first mobile terminal ID information;
[0018] or the step of authenticating, according to the first mobile terminal ID information, an authorization for decipherment may be: converting information on an ID of a second mobile terminal using a ciphering algorithm to obtain a ciphered second ID; comparing the ciphered second ID to the first mobile terminal ID information; and determining that the authorization for decipherment is authenticated when the ciphered second ID is identical to the first mobile terminal ID information; or determining that the authorization for decipherment is not authenticated when the ciphered second ID is not identical to the first mobile terminal ID information.
[0019] The disclosure further provides a device for managing security of information in a mobile terminal, including: a storage module, a text ciphering and writing module, a text reading module, a decipherment authorization authenticating module and a text deciphering and displaying module, wherein
[0020] the text ciphering and writing module is configured for: in creating and initializing a text file, writing first mobile terminal identifier (ID) information in a starting part of the text file; and in storing information, ciphering information to be stored, writing the ciphered information in the text file, and storing the text file in the storage module;
[0021] the storage module is configured for storing the text file;
[0022] the text reading module is configured for: in reading the first mobile terminal ID information and the stored information by a second mobile terminal, loading, from the storage module, the first mobile terminal ID information and the ciphered information into a memory;
[0023] the decipherment authorization authenticating module is configured for: determining a mode of displaying text information; and in displaying the stored information by the second mobile terminal, when a mode of displaying text information as plaintext is determined, authenticating, according to the first mobile terminal ID information, an authorization for decipherment of the ciphered information loaded in the memory, and when the authorization for decipherment is authenticated; and when the authorization for decipherment is authenticated, sending the text deciphering and displaying module a notification of an authenticated authorization for decipherment; and
[0024] the text deciphering and displaying module is configured for: after receiving the notification sent by the decipherment authorization authenticating module, deciphering the ciphered information loaded in the memory and displaying the deciphered information as plaintext.
[0025] In an embodiment, the device may further include a ciphertext displaying module configured for, when receiving from the decipherment authorization authenticating module, a notification to display text information in cipher, displaying ciphertext by: on a display interface of the second mobile terminal, displaying, in cipher, the information loaded in the memory while disabling a function of information creation, modification and deletion, wherein
[0026] the decipherment authorization authenticating module may be configured for: when a mode of displaying text information in cipher is determined and/or the authorization for decipherment is not authenticated, sending the ciphertext displaying module the notification to display text information in cipher.
[0027] In an embodiment, the device may further include a text display setting module configured for providing a user with an interface for setting a mode of displaying text information, wherein
[0028] the text deciphering and displaying module may be further configured for displaying text information in the mode of displaying text information set by the user using the text display setting module.
[0029] The disclosure further provides a mobile terminal configured for: in creating and initializing a text file, writing mobile terminal identifier (ID) information in a starting part of the text file, and in storing information, ciphering information to be stored, writing the ciphered information in the text file, and storing the text file; in reading mobile terminal ID information and stored information, loading the to-be-read mobile terminal ID information and ciphered information into a memory, determining a mode of displaying text information, and in displaying the read stored information, when a mode of displaying text information as plaintext is determined, authenticating, according to the read mobile terminal ID information, an authorization for decipherment of the ciphered information loaded in the memory, and when the authorization for decipherment is authenticated, deciphering the ciphered information loaded in the memory and displaying the deciphered information as plaintext.
[0030] In an embodiment, the mobile terminal may be further configured for: when a mode of displaying text information in cipher is determined and/or the authorization for decipherment is not authenticated, displaying ciphertext by
[0031] on a display interface of the mobile terminal, displaying, in cipher, the information loaded in the memory while disabling a function of information creation, modification and deletion.
[0032] In an embodiment, the mobile terminal may be further configured for: providing a user with an interface for setting a mode of displaying text information, and displaying text information in the mode of displaying text information set by the user via the interface for setting a mode of displaying text information.
[0033] With the method and device for managing security of information in a mobile terminal, as well as the mobile terminal according to the disclosure, in creating and initializing a text file, first mobile terminal ID information is written in a starting part of the text file; and in storing information, information to be stored is ciphered and written in the text file, and the text file is stored; in reading first mobile terminal ID information and stored information, the first mobile terminal ID information and the ciphered information are loaded into a memory; and a mode of displaying text information is determined; and in displaying the stored information, when it is determined to display text information as plaintext, authentication is performed to determine if a local second mobile terminal is authorized to decipher the ciphered information loaded in the memory according to the loaded first mobile terminal ID information, and when the second mobile terminal is authorized, the ciphered information loaded in the memory is deciphered and displayed as plaintext. With the disclosure, information stored in a mobile terminal is ciphertext and an authorization for decipherment has to be authenticated before ciphered information can be deciphered. Therefore, even if a second user connects a first mobile terminal of a first user to a computer via a USB and then copies data stored in the first mobile terminal to a second mobile terminal (especially of the same brand and the same model as the first mobile terminal), as identifier information of the second mobile terminal differs from that of the first mobile terminal, the second mobile terminal is not authorized to decipher the copied information, which then cannot be displayed or cannot be displayed normally. Thus, information stored in a mobile terminal of a user will not be stolen by someone else.
[0034] In addition, as mobile terminal ID information is available to no one other than a user of the mobile terminal, nobody can steal information stored in the mobile terminal using a PC-side software of the mobile terminal, thereby ensuring security of information stored in the mobile terminal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a flowchart of implementing a method for managing security of information in a mobile terminal according to the disclosure;
[0036] FIG. 2 is a schematic diagram of a structure of a text file according to the disclosure;
[0037] FIG. 3 is a schematic diagram of a structure of a device for managing security of information in a mobile terminal according to the disclosure; and
[0038] FIG. 4 is a flowchart of implementing a method for managing security of information in a mobile terminal according to an embodiment of the disclosure.
DETAILED DESCRIPTION
[0039] According to embodiments of the disclosure, in creating and initializing a text file, first mobile terminal ID information is written in a starting part of the text file; and in storing information, information to be stored is ciphered and written in the text file, and the text file is stored; in reading the first mobile terminal ID information and the stored information, the first mobile terminal ID information and the ciphered information are loaded into a memory; a mode of displaying text information is determined; in displaying the stored information, when it is determined to display text information as plaintext, authentication is performed to determine if a local mobile terminal is authorized to decipher the ciphered information loaded in the memory according to the first mobile terminal ID information, and when the mobile terminal is authorized, the ciphered information is deciphered and displayed as plaintext.
[0040] The first mobile terminal ID information may be read by reading the starting part of the text file of a length of the first mobile terminal ID information. In reading the stored information, the cipher information in the text file, starting from an offset point, may be read into the memory, where a length between a starting point of the text file and the offset point equals the length of the first mobile terminal ID information.
[0041] When a mode of displaying text information in cipher is determined and/or the authorization for decipherment is not authenticated, ciphertext is displayed by: on a display interface of a second mobile terminal, displaying, in cipher, the information loaded in the memory while disabling a function of information creation, modification and deletion.
[0042] The mobile terminal according to the disclosure may further provide a user with an interface for setting a mode of displaying text information, via which the user sets a mode of displaying text information, such as displaying text information as plaintext or displaying text information in cipher.
[0043] The disclosure is elaborated below with reference to accompanying drawings and specific embodiments.
[0044] FIG. 1 is a flowchart of implementing a method for managing security of information in a mobile terminal according to the disclosure. As shown in FIG. 1 , the method includes steps as follows.
[0045] In Step 101 , in creating and initializing a text file, first mobile terminal ID information is written in a starting part of the text file; and in storing information, information to be stored is ciphered and written in the text file, and the text file is stored.
[0046] Specifically, in creating and initializing a text file, a first mobile terminal writes ID information uniquely identifying the first mobile terminal into the starting part of the text file.
[0047] Then, after a user inputs the information to be stored through an interface, the first mobile terminal writes the information input by the user into the text file immediately after the first mobile terminal ID information.
[0048] That is, data in the text file are formed by two parts, namely, a first part of data, that is, data in the starting part, which contains the first mobile terminal ID information, and a second part of data, that is, the user data information to be stored, which starts immediately after the first mobile terminal ID information.
[0049] Here, the first mobile terminal ID information is written only once when a file is initialized after the file is created, and is no longer written when user data are written subsequently.
[0050] Before writing the information to be stored into the text file, the first mobile terminal needs to cipher the information input by the user, which may be done using an existing ciphering algorithm such as MD5; then the ciphered information is written in the text file and the text file is stored. The structure of the text file is as shown in FIG. 2 .
[0051] The first mobile terminal ID information may be: an Electronic Serial Number (ESN), a Mobile Equipment Identifier (MEID), or a unique identifier of the first mobile terminal set by a mobile terminal manufacturer. The first mobile terminal ID information serves as data for authenticating the authorization for decipherment of the text file when information is read subsequently. The first mobile terminal ID information identifies the mobile terminal creating the text file and the mobile terminal that is authorized to read and decipher the text file. Of course, the first mobile terminal ID information may also be: a ciphered ID obtained by converting an ESN, a MEID, or a unique identifier of the first mobile terminal set by a mobile terminal manufacturer using, for example, an existing ciphering algorithm.
[0052] In Step 102 , in reading the first mobile terminal ID information and the stored information, the first mobile terminal ID information and the ciphered information are loaded into a memory.
[0053] Specifically, the first mobile terminal ID information may be read by reading the starting part of the text file of a length of the first mobile terminal ID information. In reading the stored information, the cipher information in the text file, starting from an offset point, may be read into the memory, where a length between a starting point of the text file and the offset point equals the length of the first mobile terminal ID information.
[0054] In addition, the mobile terminal according to the disclosure may provide a user with an interface for setting a mode of displaying text information, via which the user sets a mode of displaying text information, such as displaying text information as plaintext or displaying text information in cipher. Specifically, a mode of displaying the stored information may be se. When a user uses a mobile terminal, text information may be displayed in the mobile terminal as plaintext or in cipher, for example. Meanwhile, an entry password for switching a mode of displaying text information may be set for a mobile terminal. The entry password is known only by the user of the mobile terminal, such that an illegal user cannot perform any illegal operation on a mode of displaying text information of the mobile terminal.
[0055] When the user of a mobile terminal sets a mode of displaying text information as plaintext, the mobile terminal displays text information as plaintext. When the user of a mobile terminal sets a mode of displaying text information in cipher, the mobile terminal displays text information as ciphertext, and may further disable a function of information creation, modification and deletion.
[0056] In Step 103 , a second mobile terminal to display stored information determines a mode of displaying text information; and Step 104 is performed if text information is to be displayed as plaintext, or Step 106 is performed if text information is to be displayed in cipher.
[0057] In Step 104 , in displaying the stored information, an authorization for decipherment of the ciphered information loaded in the memory is authenticated according to the first mobile terminal ID information; Step 105 is performed if it is authenticated, or Step 106 is performed if the authorization for decipherment is not authenticated.
[0058] Here, in displaying the stored information, the second mobile terminal performs authentication to determine if the second mobile terminal itself is authorized to decipher the ciphered information loaded in the memory according to the first mobile terminal ID information. Specifically, the second mobile terminal reads information on an ID of the second mobile terminal itself, that is, the information uniquely identifies the second mobile terminal, such as an ESN or MEID of the second mobile terminal, or a ciphered ID obtained by converting the ESN or MEID of the second mobile terminal. The second mobile terminal compares the read information on the ID of the second mobile terminal with the first mobile terminal ID information, namely, the data for authenticating the authorization for decipherment. Alternatively, the second mobile terminal compares the ciphered ID obtained by converting the information on the ID of the second mobile terminal using a ciphering algorithm with the first mobile terminal ID information. When the compared data are the same, the second mobile terminal is authenticated and step 105 is performed. When the compared data are different, the second mobile terminal is not authenticated and step 106 is performed.
[0059] In Step 105 , the ciphered information loaded in the memory is deciphered and displayed as plaintext.
[0060] Specifically, the second mobile terminal deciphers the ciphertext in the text file loaded in the memory using an existing deciphering algorithm and displays the deciphered plaintext before the user of the second mobile terminal via an interface.
[0061] In Step 106 , ciphertext is displayed.
[0062] Specifically, if the authorization for decipherment is not authenticated, then ciphertext is displayed. Namely, on the display interface of the second mobile terminal, the information loaded in the memory is displayed in cipher while a function of information creation, modification and deletion is disabled.
[0063] The method according to the disclosure is elaborated below with an example in which information in a first mobile terminal is contact information in a phone book and mobile terminal ID information is an ESN.
[0064] When initially creating and initializing a database file for a phone book, the first mobile terminal reads the ESN of the first mobile terminal itself, and writes the read ESN in the starting part of a phone book text file as data for authenticating an authorization for decipherment of the text file of the phone book so as to identify the mobile terminal to which the phone book text file belongs; data following the data for authenticating an authorization for decipherment are actual data of the phone book. The first mobile terminal ciphers contact information of the phone book input by a user and stores the ciphered information in the database file.
[0065] In addition, the user of the first mobile terminal may set a mode of displaying the phone book, and provide protection by authorization in modification of the mode of displaying the phone book using an entry password such that no illegal user can perform any illegal operation on the mode of displaying the contact information in the phone book of the first mobile terminal.
[0066] When the user of the first mobile terminal sets that text information is to be displayed in cipher, the first mobile terminal displays the contact information in the phone book to the user in cipher while disabling a function of contact information creation, modification and deletion.
[0067] As shown in FIG. 4 , a flow of reading and displaying contact information in a phone book by a second mobile terminal may include steps as follows.
[0068] In Step 401 , a second mobile terminal reads contact information in a phone book from a database file into a memory.
[0069] In Step 402 , the second mobile terminal determines a mode of display; Step 403 is performed if the file is to be displayed as plaintext, or Step 405 is performed if the file is to be displayed in cipher.
[0070] In Step 403 , the second mobile terminal authenticates an authorization for decipherment according to a first ESN; Step 404 is performed if it is authenticated, or Step 405 is performed if the authorization for decipherment is not authenticated.
[0071] Specifically, the second mobile terminal reads a second ESN of the second mobile terminal itself, and the first ESN loaded in an memory from the starting part of the database file containing the contact information. When the first ESN and the second ESN are identical, or respective ciphered IDs of the first ESN and the second ESN are the same, the second mobile terminal is authenticated and Step 404 is performed; otherwise, the second mobile terminal is not authenticated and Step 405 is performed.
[0072] In Step 404 , the second mobile terminal deciphers the contact information in the phone book loaded in the memory; and then Step 406 is performed.
[0073] In Step 405 , the second mobile terminal displays ciphertext; and then Step 407 is performed.
[0074] That is, the contact information is not deciphered but is displayed as ciphertext while a function of contact information creation, modification and deletion is disabled.
[0075] Here, even if a mode of displaying text information as plaintext is set, the contact information is still displayed in cipher, and the function of contact information creation, modification and deletion is disabled.
[0076] In Step 406 , the second mobile terminal displays before a user the contact information in the phone book as plaintext.
[0077] In Step 407 , the flow of reading and displaying the contact information in the phone book ends.
[0078] When the user of a mobile terminal needs to add new contact information in a phone book, the following steps may be performed.
[0079] In Step I, a user inputs, on an interface of a mobile terminal, new contact information, such as a name, a phone number, an Email address, an address, a company, a position and a birthday of a new contact, and clicks โsaveโ.
[0080] In Step II, the mobile terminal ciphers the contact information input by the user and converts, in a memory, the ciphered contact information into cache data matching an interface of a database.
[0081] In Step 3, the mobile terminal writes the cache data into the database and finally writes the ciphered contact information in the phone book into a file system of the database through a database operation.
[0082] The flow of adding contact information to a phone book is then completed.
[0083] When a user of a mobile terminal needs to modify read contact information, the following steps may be performed.
[0084] In Step I, a user edits and modifies, on an interface of a mobile terminal, contact information, such as a name, a phone number, an Email address, an address, a company, a position and a birthday of a contact, and clicks โsaveโ.
[0085] Here, the mobile terminal has displayed before the user, the contact information of a phone book as plaintext.
[0086] In Step II, the mobile terminal ciphers the contact information input by the user and converts, in a memory, the ciphered contact information into cache data matching an interface of a database.
[0087] In Step 3, the mobile terminal writes the cache data into the database to replace contact information in the database existing before the modification, and finally writes ciphertext of the modified contact information into a file system of the database through a database operation.
[0088] The flow of modifying contact information is then completed.
[0089] When a user of a mobile terminal needs to delete read contact information, the following steps may be performed.
[0090] In Step 1, a user selects contact information to be deleted on an interface of a mobile terminal and clicks โOKโ.
[0091] Here, the mobile terminal has displayed, before the user, the contact information of a phone book as plaintext.
[0092] In Step 2, the mobile terminal deletes the contact information to be deleted from a database.
[0093] In Step 3, the mobile terminal deletes the contact information to be deleted from a memory.
[0094] The flow of deleting contact information in a phone book is then completed.
[0095] These are four basic operations performed in a mobile terminal on contact information of a phone book, that is, reading and displaying, adding/creating, modifying, and deleting. Other management of contact information of a phone book may be implemented by combining the four basic operations.
[0096] The disclosure also provides a device for managing security of information in a mobile terminal. As shown in FIG. 3 , the device includes a storage module, a text ciphering and writing module, a text reading module, a decipherment authorization authenticating module and a text deciphering and displaying module. The device may further include a ciphertext displaying module.
[0097] The text ciphering and writing module is configured for: in creating and initializing a text file, writing first mobile terminal identifier (ID) information in a starting part of the text file; and in storing information, ciphering information to be stored, writing the ciphered information in the text file, and storing the text file in the storage module;
[0098] The storage module is configured for storing the text file;
[0099] The text reading module is configured for: in reading the first mobile terminal ID information and the stored information by a second mobile terminal, loading, from the storage module, the first mobile terminal ID information and the ciphered information into a memory.
[0100] The first mobile terminal ID information may be read by reading the starting part of the text file of a length of the first mobile terminal ID information. The second mobile terminal may read user data information starting from an offset point, where a length between a starting point of the text file and the offset point equals the length of the first mobile terminal ID information.
[0101] The decipherment authorization authenticating module is configured for: determining a mode of displaying text information; and in displaying the stored information by the second mobile terminal, when a mode of displaying text information as plaintext is determined, authenticating, according to the first mobile terminal ID information, an authorization for decipherment of the ciphered information loaded in the memory, and when the authorization for decipherment is authenticated; and when the authorization for decipherment is authenticated, sending the text deciphering and displaying module a notification of an authenticated authorization for decipherment.
[0102] The text deciphering and displaying module is configured for: after receiving the notification sent by the decipherment authorization authenticating module, deciphering the ciphered information loaded in the memory and displaying the deciphered information as plaintext.
[0103] The ciphertext displaying module may be configured for, when receiving from the decipherment authorization authenticating module, a notification to display text information in cipher, displaying ciphertext by: on a display interface of the second mobile terminal, displaying, in cipher, the information loaded in the memory while disabling a function of information creation, modification and deletion.
[0104] The decipherment authorization authenticating module may be further configured for: when a mode of displaying text information in cipher is determined and/or the authorization for decipherment is not authenticated, sending the ciphertext displaying module the notification to display text information in cipher.
[0105] The device may further include a text display setting module configured for providing a user with an interface for setting a mode of displaying text information. The text deciphering and displaying module may be further configured for displaying text information in the mode of displaying text information set by the user using the text display setting module.
[0106] In an actual application, the user may sets to display text information as plaintext or ciphertext using the interface for setting a mode of displaying text information.
[0107] The disclosure also provides a mobile terminal configured for: in creating and initializing a text file, writing mobile terminal identifier (ID) information in a starting part of the text file, and in storing information, ciphering information to be stored, writing the ciphered information in the text file, and storing the text file; in reading mobile terminal ID information and stored information, loading the to-be-read mobile terminal ID information and ciphered information into a memory, determining a mode of displaying text information, and in displaying the read stored information, when a mode of displaying text information as plaintext is determined, authenticating, according to the read mobile terminal ID information, an authorization for decipherment of the ciphered information loaded in the memory, and when the authorization for decipherment is authenticated, deciphering the ciphered information loaded in the memory and displaying the deciphered information as plaintext.
[0108] The mobile terminal may be further configured for: when a mode of displaying text information in cipher is determined and/or the authorization for decipherment is not authenticated, displaying ciphertext by
[0109] on a display interface of the mobile terminal, displaying, in cipher, the information loaded in the memory while disabling a function of information creation, modification and deletion.
[0110] The mobile terminal may be further configured for: providing a user with an interface for setting a mode of displaying text information, and displaying text information in the mode of displaying text information set by the user via the interface for setting a mode of displaying text information.
[0111] What described are merely embodiments of the disclosure and are not to be construed as limitation to the protection scope of the disclosure.
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Disclosed are a method and device for managing security of information in a mobile terminal, as well as a mobile terminal. In creating and initializing a text file, first mobile terminal ID information is written in a starting part of the text file; and in storing information, information to be stored is ciphered and written in the text file, and the text file is stored; in reading the first mobile terminal ID information and the stored information, the first mobile terminal ID information and the ciphered information are loaded into a memory; and a mode of displaying text information is determined; and in displaying the stored information, when it is determined to display text information as plaintext, authentication is performed to determine if a local mobile terminal is authorized to decipher the ciphered information loaded in the memory according to the first mobile terminal ID information, and when the mobile terminal is authorized, the ciphered information is deciphered and displayed as plaintext, or ciphertext is displayed if the mobile terminal is not authorized. With the disclosure, it is possible to effectively stop someone other than a user of a mobile terminal from connecting the mobile terminal to a computer through a Universal Serial Bus (USB) and stealing user information in the mobile terminal.
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[0001] The instant invention relates to concentrated aqueous solutions of hexasulphonated stilbene optical brighteners which are storage-stable in the absence of solubilizing agents like urea.
Prior Art
[0002] Hexasulphonated stilbene optical brightening agents (OBAs) are a well-established means of producing coated papers with a high degree of whiteness. Such optical brighteners are most conveniently marketed and used in the form of aqueous solutions. Japanese Kokai 62-106965 discloses an optical brightener, or a salt thereof,
in which R 1 and R 2 each independently represents a group selected from
and A represents a group selected from a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, which may have a side chain, a hydroxymethyl group, a hydroxyethyl group, a methylthioethyl group, a benzyl group, a carboxymethyl group and a carboxyethyl group.
[0003] According to the Kokai, said optical brighteners have a very high solubility in water and can be commercialized in the form of a thick solution after removing the sodium chloride produced in the reaction and concentrating the water content by an appropriate method. The optical brighteners are claimed to be very effective for the whitening of paper in a surface treatment.
[0004] Each example of the Kokai describes the preparation of an optical brightener which is desalinated by ultrafiltration to give a thick solution. Supposing that in Example 1 the reaction of the starting compounds gives a 100% yield of said optical brightener then the maximal concentration in said thick solution would be 0.214 mol/kg (30-32%). Each solution is then rendered storage-stable by the addition of 10% urea.
[0005] This document therefore teaches that aqueous solutions of said optical brighteners are unstable at concentrations equal to 0.214 mol/kg (30-32%) without the addition of urea.
[0006] There is however a demand for more concentrated aqueous solutions of optical brighteners. The concentration of the aqueous solution is of particular significance when the brightener is applied in a pigmented coating composition; it is well-known that papermakers aim to minimise the water-content of the coating composition in order to minimise drying energy and to minimise water and binder migration into the base paper. (See, for example, โThe Essential Guide to Aqueous Coating of Paper and Boardโ, ed. T. W. R. Dean, PITA, 1997.)
DESCRIPTION OF THE INVENTION
[0007] Surprisingly and in contrast to the teaching of said Japanese document it has now been found that certain of these hexasulphonated stilbene OBAs can be prepared in the form of highly concentrated aqueous solutions that are storage-stable at concentrations of up to 0.350 mol/kg (about 54% by weight). When applied to the surface of paper in either a pigmented coating composition or in the size-press these aqueous solutions provide superior fluorescent whitening effects.
[0008] An object of the present invention therefore is a storage-stable aqueous solution comprising an optical brightener of formula (1)
wherein
M is hydrogen, an alkali metal cation, ammonium, or ammonium which is mono-, di- or trisubstituted by a C 2 -C 3 -hydroxyalkyl radical, preferably hydrogen or a sodium cation, and n is from 1 to 4, preferably is 1 or 2,
characterized in that the amount of the optical brightener is higher than 0.214 mol/kg, preferably from 0.215 to 0.350 mol/kg, more particularly from 0.250 to 0.340 mol/kg, and that no solubilizing agent is contained in the solution.
[0011] The aqueous solutions of the optical brightener(s) may optionally contain one or more carriers, antifreezes, preservatives, complexing agents etc., as well as organic by-products formed during the preparation of the optical brightener.
[0012] Carriers are known to give improved whitening characteristics and may be, e.g., polyethylene glycols, polyvinyl alcohols or carboxymethylcelluloses.
[0013] Antifreezes may be, e.g., urea, diethylene glycol or triethylene glycol.
[0014] The compounds of formula (1) are prepared by stepwise reaction of a cyanuric halide with
a) a diamine of formula (A)
b) an amine of formula (B)
c) an amine of formula (C)
[0018] As a cyanuric halide there may be employed the bromide or, preferably, the chloride.
[0019] Each reaction may be carried out in an aqueous medium, the cyanuric halide being suspended in water, or in an aqueous/organic medium, the cyanuric halide being dissolved in a solvent such as acetone. Each amine may be introduced without dilution, or in the form of an aqueous solution or suspension. The amines can be reacted in any order, although it is preferred to react the aromatic amines first. Each amine may be reacted stoichiometrically, or in excess. Typically, the aromatic amines are reacted stoichimetrically, or in slight excess; the aliphatic amines are generally employed in an excess of 5-30% over stoichiometry.
[0020] For substitution of the first halogen of the cyanuric halide, it is preferred to operate at a temperature in the range of 0 to 20ยฐ C., and under acidic to neutral pH conditions, preferably in the pH range of 2 to 7. For substitution of the second halogen of the cyanuric halide, it is preferred to operate at a temperature in the range of 20 to 60ยฐ C., and under weakly acidic to weakly alkaline conditions, preferably at a pH in the range of 4 to 8. For substitution of the third halogen of the cyanuric halide, it is preferred to operate at a temperature in the range of 60 to 102ยฐ C., and under weakly acidic to alkaline conditions, preferably at a pH in the range of 7 to 10. The pH may be controlled by addition of suitable acids or bases as necessary, preferred acids being e.g., hydrochloric acid, sulphuric acid, formic acid or acetic acid, preferred bases being e.g., alkali metal (e.g., lithium, sodium or potassium) hydroxides, carbonates or bicarbonates, or aliphatic tertiary amines e.g. triethanolamine or triisopropanolamine.
[0021] A further object of the instant invention is the process for the preparation of said aqueous solutions wherein the compounds of formula (1) are prepared as described above and wherein the alkali metal or amine salt that is generated as a by-product of each reaction between an amine and a cyanuric halide is removed from the reaction solution.
[0022] In order to prepare a stable aqueous solution with a concentration of higher than 0.214 mol/kg (32-33% by weight), preferably from 0.214 to 0.350 mol/kg, more particularly from 0.250 to 0.340 mol/kg, of a compound of formula (1) without the addition of solubilizing aids such as ethylene glycol, urea or a mono-, di- or tri-(2-hydroxyethyl)- or (2-hydroxypropyl)-amine, it is necessary to remove at least 50%, preferably at least 80 % by weight, of the alkali metal or amine salt that is generated as a by-product of each reaction between an amine and a cyanuric halide. This is preferably done by ultrafiltration or membrane filtration of the solution formed as described above. Alternatively, the compound of formula (1) can be isolated by precipitation (e.g. by the addition of acid) then redissolved.
[0023] A further object of the instant invention is the use of the instant storage-stable aqueous solutions for brightening of paper or other cellulosic substrates.
[0024] The concentrated solutions of compounds of formula (1) are particularly suitable for the brightening of paper after sheet formation. This may be effected by adding the optical brightener solution to a pigmented coating composition, or to a sizing solution or suspension.
[0025] In a preferred aspect to the instant invention, the concentrated solutions of compounds of formula (1) are applied to the surface of paper in a pigmented coating composition.
[0026] The coating compositions are essentially aqueous compositions that contain at least one binder and a white pigment, in particular an opacifying white pigment, and may additionally contain further additives such as dispersing agents and defoamers.
[0027] Although it is possible to produce coating compositions that are free from white pigments, the best white substrates for printing are made using opaque coating compositions that contain 10-70% white pigment by weight. Such white pigments are generally inorganic pigments, e.g., aluminium silicates (kaolin, otherwise known as china clay), calcium carbonate (chalk), titanium dioxide, aluminium hydroxide, barium carbonate, barium sulphate, or calcium sulphate (gypsum).
[0028] The binders may be any of those commonly used in the paper industry for the production of coating compositions and may consist of a single binder or of a mixture of primary and secondary binders. The sole or primary binder is preferably a synthetic latex, typically a styrene-butadiene, vinyl acetate, styrene acrylic, vinyl acrylic or ethylene vinyl acetate polymer. The secondary binder may be, e.g., starch, carboxymethylcellulose, casein, soy polymers, or polyvinyl alcohol.
[0029] The sole or primary binder is used in an amount typically in the range 5-25% by weight of white pigment. The secondary binder is used in an amount typically in the range 0.1-2% by weight of white pigment; starch however is typically used in the range 5-10% by weight of white pigment.
[0030] The optical brightener of formula (1) is used in an amount typically in the range 0.01-1% by weight of white pigment, preferably in the range 0.05-0.5% by Weight of white pigment.
[0031] The following examples shall explain the instant invention in more detail. โPartsโ means, if not defined differently, โparts by weightโ.
PREPARATIVE EXAMPLE 1
[0032] A solution of 21.3 parts aniline-2,5-disulphonic acid and 6.7 parts sodium hydroxide in 30 parts water is added to a stirred suspension of 15.5 parts cyanuric chloride in 50 parts ice water. The pH is kept at 6 by the dropwise addition of 30% sodium hydroxide. The mixture is stirred below 10ยฐ C. until primary aromatic amine groups can no longer be detected by the diazo reaction. A solution of 14.8 parts 4,4โฒ-diaminostilbene-2,2โฒ-disulphonic acid and 3.2 parts sodium hydroxide in 20 parts water is then added, the pH is adjusted to between 6.5 and 7.5 by the addition of 30% sodium hydroxide and the mixture is stirred at 30ยฐ C. until a negative diazo reaction is obtained. A solution of 12.2 parts L-aspartic acid in 22.9 parts 16% sodium hydoxide is added, and the mixture is heated at reflux for 6 hours, the pH being kept at 7.5 to 8.5 by the addition of 30% sodium hydroxide. The aqueous solution so-formed of (2) in the form of its sodium salt, which is approximately 0.167 mol/kg in concentration, is desalinated by membrane filtration and concentrated to 0.330 mol/kg (50% by weight). The resulting solution, 2.0% in sodium chloride, has a viscosity of 0.23-0.25 Pa.s at 20ยฐ C. and shows no signs of precipitation after 2 weeks at 5ยฐ C.
PREPARATIVE EXAMPLE 2
[0033] An aqueous solution of (3) in the form of its sodium salt at a concentration of 0.330 mol/kg (51% by weight) is prepared as described in Example 1 but using 13.5 parts L-glutamic acid in place of 12.2 parts L-aspartic acid. The resulting solution, 2.0% in sodium chloride, has a viscosity of 0.23-0.25 Pa.s at 20ยฐ C. and shows no signs of precipitation after 2 weeks at 5ยฐ C.
APPLICATION EXAMPLE 1
[0034] A coating composition is prepared containing 500 parts chalk (commercially available under the trade name Hydrocarb 90 from OMYA), 500 parts clay (commercially available under the trade name Kaolin SPS from IMERYS), 470 parts water, 6 parts dispersing agent (a sodium salt of a polyacrylic acid commercially available under the trade name Polysalz S from BASF), 200 parts latex (an acrylic ester copolymer commercially available under the trade name Acronal S320D from BASF) and 30 parts of a 10% solution of carboxymethyl cellulose (commercially available under the trade name Finnfix 5.0 from Noviant) in water. The solids content is adjusted to 65% by the addition of water, and the pH is adjusted to 8-9 with sodium hydroxide.
[0035] The solution of brightener (2) in the form of its sodium salt, made as described in Preparative Example 1, is added at a range of concentrations from 0.1 to 0.6% to the stirred coating composition. The brightened coating composition is then applied to a commercial 75 gsm neutral-sized white paper base sheet using an automatic wire-wound bar applicator with a standard speed setting and a standard load on the bar. The coated paper is then dried for 5 minutes in a hot air flow. The dried paper is allowed to condition, then measured for CIE Whiteness on a calibrated Elrepho spectrophotometer.
TABLE 1 CIE Whiteness using OBA Concentration (%) Brightener of Example 1 0 92.0 0.1 97.9 0.2 102.6 0.3 106.2 0.4 108.4 0.5 110.3 0.6 112.2
[0036] The results are also shown in graphical form in FIG. 1 .
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The instant invention relates to concentrated aqueous solutions of hexasulphonated stilbene optical brighteners which are storage-stable in the absence of solubilizing agents like urea. By removal of salts resulting from the preparation of the optical brightener one can obtain a concentration of up to 0.350 mol/kg without losing storage stability. The reduced water content enables coating compositions which require less drying energy and which show less water and binder migration into the paper.
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FIELD OF THE INVENTION
The present invention relates to an electronic helmet, particularly relates to an electronic helmet and a method for noise cancellation.
BACKGROUND OF THE INVENTION
Convenience of daily life is improved along with science and technology progress. However, environment noise from transportation and industry causes damages on the sense of hearing. Presently, methods for noise cancellation are classified into passive noise control (PNC) and active noise control (ANC). Passive noise control is sound reduction by noise-isolating material such as sound-absorbing cotton. However, passive noise control neither truly eliminates noise nor totally overcomes low-frequency noise even using thick and weighty sound-absorbing cotton. Therefore, passive noise control neither resolves environment noise issue nor is convenient to be portable. Active noise control is a method for reducing unwanted sound by the addition of anti-noise. The anti-noise, whose phase is opposite to noise but amplitude is same as the ones of noise, is generated by a speaker according to a result of environment noise detection by a microphone. The environment noise cancellation can be achieved with the anti-noise to destroy strength of noise by forming destructive interference.
Presently, a helmet with active noise control combines an active noise control system into the helmet, which may provide a rider's head protection and environment noise cancellation. However, high cost results in little utilization frequency for such the helmet, except in aircraft industry, people working at aircraft stations protect themselves with such the helmets against noises from engines of aircraft.
US patent application of publication No. 20050117754 discloses a helmet of active noise cancellation, a vehicle system thereof and a method therefor. A rider may use an adaptive active noise control to cancel noise from wind, other vehicles and environment for improvement of riding quality. However, this helmet does not have noise cancellation combined with music preservation function and the peripheral circuit cost therefor is still too expensive.
Accordingly, the present invention provides an electronic helmet, and especially, an electronic helmet and cancellation method to integrate active noise control, hands-free communication, music listening, and voice navigation for noise cancellation.
SUMMARY OF THE INVENTION
One of objectives of the present invention provides an electronic helmet by using a mobile device as a platform of signal calculation/processing to replace a digital signal processor in a traditional active noise control. The mobile device may execute active noise control and generate control signals for controlling a speaker to output anti-noise that can cancel out the noise detected by a microphone. The noise cancellation, reduction of product cost and weight, readily portable convenience, and improvement of riding quality can be achieved.
Generally, it is necessary for a rider to wear a helmet when hitting a road. Wearing an earphone makes the helmet feel inconvenient, and making music out makes others feel bad. Accordingly, one of objectives of the present invention provides an electronic helmet of music-listening function that integrates a mobile device to execute a dual-channel and audio-integrating active noise control program and utilize a speaker to output sound of music and anti-noise. Thus, such an electronic helmet can cancel environment noise and preserve sound of music.
One of objectives of the present invention provides an electronic helmet of hands-free communication function for the rider's and others' safeties when the rider would like to answer a call in riding. A mobile device executes an adaptive acoustic echo cancellation program and outputs the answer's voice and anti-noise with a speaker to cancel echo interference in communication and ensure answering important calls for the rider in using hands-free communication.
One of objectives of the present invention provides an electronic helmet of voice navigation function. Wireless positioning provides the rider a route and a direction in a voice way and ensures the rider safety when he or she checks transportation signs.
Accordingly, an electronic helmet of noise cancellation includes: an electronic helmet having a plurality of microphones, a plurality of speakers, and a first communication unit, wherein the microphones are respectively electrically coupled to the first communication unit and configured to at least detect an sound or a noise, and the speakers are respectively electrically coupled to the first communication unit and configured to at least output the sound or an anti-noise; and a mobile device having a second communication unit and a control unit, wherein the control unit is electrically coupled to the second communication unit; and wherein after the first communication unit of the electronic helmet are linked with the second communication unit of the mobile device, the control unit of the mobile device generates a plurality of control signals in the light of the sound or the noise detected by the microphones of the electronic helmet, and the speakers of the electronic helmet are controlled by the mobile device with the control signals to output the sound or the anti-noise that cancels out the noise. Thus, noise cancellation and riding quality improvement are achieved.
Accordingly, a method for noise cancellation includes: starting an electronic helmet and a control unit in a mobile device; coupling a first communication unit in the electronic helmet with a second communication unit in the mobile device; at least detecting an sound or a noise by a plurality of microphones in the electronic helmet; generating a plurality of control signals by the control unit in the mobile device in the light of the sound or the noise detected by the microphones of the electronic helmet; and at least outputting the sound or an anti-noise by a plurality of speakers that are controlled by the mobile device with the control signals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic system block diagram illustrating an electronic helmet for noise cancellation according to the present invention.
FIG. 2 is a schematic diagram illustrating the structure of an electronic helmet according to the present invention.
FIG. 3 is a schematic flow diagram illustrating one embodiment of active noise control according to the present invention.
FIG. 4 is a schematic flow diagram illustrating another embodiment of dual-channel active noise control program integrated with sound according to the present invention.
FIG. 5 is a schematic flow diagram illustrating one embodiment of adaptive acoustic echo cancellation program according to the present invention.
FIG. 6 is a schematic flow diagram illustrating a method for noise cancellation according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The above objects, technical features and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings. The presently described embodiments will be understood by reference to the drawings, but the sizes or ratios of components shown in drawings are not intended to limit the scope of the disclosure.
FIG. 1 is a schematic system block diagram illustrating an electronic helmet for noise cancellation according to the present invention. Shown in FIG. 1 , an electronic helmet for noise cancellation includes an electronic helmet 10 having some microphones 101 , some speakers 102 , and a first communication unit 103 , and a mobile device 20 having a second communication unit 201 , and a control unit 202 . These microphones 101 are electrically coupled to the first communication unit 103 and configured to detect sound to be wanted (such as music) and noise not to be wanted (such as noise from vehicles). The speakers 102 are electrically coupled to the first communication unit 103 and configured to output sound or anti-noise. The control unit 202 is electrically coupled to the second communication unit 201 . After the second communication unit 201 of the mobile device 20 is coupled to the first communication unit 103 of the electronic helmet 10 , the control unit 202 generates multitudes of control signals in the light of at least the sound or noise detected by the microphones 101 . The speakers 102 are controlled by the control signals of the mobile device 20 to at least output the sound or the anti-noise for noise cancellation. Thus, noise can be cancelled and riding quality can be improved.
In a preferred embodiment of electronic helmet, the electronic helmet 10 further includes a power supply device of battery power to provide power to the microphones 101 , the speakers 102 , and the first communication unit 103 .
In a preferred embodiment of electronic helmet, the mobile device 20 may be a smart phone, a tablet computer or a mobile telecommunication, but not limited to.
In a preferred embodiment of electronic helmet, the first communication unit 103 and the second communication unit 201 may be one of a wired telecommunication module and a wireless telecommunication module.
In a preferred embodiment of electronic helmet, the wireless telecommunication module may be a blue tooth module.
FIG. 2 is a schematic diagram illustrating the structure of an electronic helmet according to the present invention. Shown in FIG. 2 , the electronic helmet 10 includes three microphones 101 a , 101 b and 101 c , and two speakers 102 a and 102 b . The speakers 102 a and 102 b are electrically coupled to the first communication unit 103 (not shown in FIG. 2 ) and respectively deposited at two sides of the electronic helmet 10 to close to the position corresponding to user's ears, and configured to output the sound or the anti-noise. The three microphones 101 a , 101 b and 101 c are electrically coupled to the first communication unit 103 . The three microphones 101 a , 101 b , and 101 c are deposited within the electronic helmet 10 . Both of the microphones 101 a and 101 b are deposited at the right and left inner sides of the electronic helmet 10 and below the two speakers 102 a and 102 b , the microphone 101 c is deposited around user's mouse position. The three microphones 101 a , 101 b , and 101 c are configured to at least detect the sound or the noise. When the user wears the electronic helmet 10 on the user's head, the electronic helmet 10 may create two quiet zones at the sides of the user's ears to cancel noise. It is noted that the numbers and arrangement of the microphones 101 a , 101 b and 101 c and the speakers 102 a and 102 b in the electronic helmet 10 are only one embodiment for function and effect illustration of the electronic helmet 10 , not to be limited in the present invention or limit the scope of the present invention.
In electronic helmet of the present invention, the mobile device 20 further includes an active noise control program, a dual-channel audio-integrating active noise control program, and an adaptive acoustic echo cancellation program. A mobile phone application program is preferred ones for these programs aforementioned. Once user starts the mobile phone application program of the mobile device 20 , the second communication unit 201 in the mobile device 20 and the first communication unit 103 in the electronic helmet 10 are linked with each other, and the control unit 202 in the mobile device 20 executes the functions of the mobile phone application program.
The operation of the programs will be described as follows.
FIG. 3 is a schematic flow diagram illustrating one embodiment signal of active noise control program according to the present invention. Please refer to FIG. 2 to FIG. 3 , the active noise control program utilizes the three microphones 101 a , 101 b and 101 c and the two speakers 102 a and 102 b deposited in the electronic helmet 10 as a signal input or output device. It is noted that S 1 (z) in FIG. 3 is a secondary path frequency response from the speaker 102 a to the microphone 101 a , S 2 (z) is the one from the speaker 102 b to the microphone 101 b . Two estimated secondary path frequency responses ล 1 (z), and ล 2 (z), which are respectively corresponding to the secondary path frequency responses S 1 (z) and S 2 (z), are determined by selecting some suitable testing signals (such as white noises) to be outputted by the speakers 102 a and 102 b and detected by the microphones 101 a and 101 b . Once the first communication unit 103 in the electronic helmet 10 and the second communication unit 201 in the mobile device 20 are linked, the electronic helmet 10 and the mobile device 20 start off receiving and transmitting signal. The three microphones 101 a , 101 b and 101 c respectively detect the noises d 1 (n), d 2 (n) and x(n). Next, the control unit 202 of the mobile device 20 starts off executing the active noise control program after receiving the noises d 1 (n), d 2 (n) and x(n). Two adaptive wave filters W 1 (z) and W 2 (z) in program forms respectively generate two control signals y 1 (n) and y 2 (n) after receiving the noise x(n). Next, after the two control signals y 1 (n) and y 2 (n) are processed with the secondary path frequency responses S 1 (z) and S 2 (z) and outputted by the speakers 102 a and 102 b , two anti-noises b 1 (n) and b 2 (n) are respectively generated and received by the microphones 101 a and 101 b . Signal e 1 (n) may be generated by processing the anti-noises b 1 (n) and the noise d 1 (n) that is detected by the microphone 101 a at same time. Meanwhile, signal e 2 (n) is generated by processing the anti-noises b 2 (n) and the noise d 2 (n) that is detected by the microphone 101 b . Next, both the two signals e 1 (n) and e 2 (n) together with the next noise x(n) may be inputted into a filtering algorithm A after they are processed with the secondary path frequency responses ล 1 (z) and ล 2 (z). The filtering algorithm A can adjust the two adaptive wave filters W 1 (z) and W 2 (z). The aforementioned process can be executed again after the next noises d 1 (n) and d 2 (n) are respectively detected by the two adjusted adaptive wave filters W 1 (z) and W 2 (z) together with the two microphones 101 a and 101 b . In the embodiment, the filtering algorithm A may be Filtered-X Least Mean Square algorithm, but not limited to. The active noise control program of the embodiment is implemented by the control unit 202 of the mobile device 20 and generates the control signals y 1 (n) and y 2 (n) in the light of the noises d 1 (n), d 2 (n) and x(n) detected by the microphones 101 a , 101 b and 101 c of the electronic helmet 10 . The two speakers 102 a and 102 b in the electronic helmet 10 output the anti-noises b 1 (n) and b 2 (n) to cancel noises d 1 (n), d 2 (n) and x(n).
FIG. 4 is a schematic flow diagram illustrating another embodiment of dual-channel and audio-integrating active noise control program according to the present invention. Please refer to FIG. 2 and FIG. 4 , the embodiment of dual-channel and audio-integrating active noise control program utilizes the three microphones 101 a , 101 b and 101 c in the electronic helmet 10 and the two speakers 102 a and 102 b as signal input or output devices. It is noted that S 11 (z) in FIG. 4 is a secondary path frequency response from the speaker 102 a to the microphone 101 a , S 21 (z) is the one from the speaker 102 b to the microphone 101 a , S 12 (z) is the one from the speaker 102 a to the microphone 101 b , and S 22 (z) is the one from the speaker 102 b to the microphones 101 b . Four estimated secondary path frequency responses ล 11 (z), ล 12 (z), ล 21 (z) and ล 22 (z) are determined by selecting a little suitable testing signals (such as white noise) to be outputted by the two speakers 102 a and 102 b and detected by the microphones 101 a and 101 b . Once the first communication unit 103 in the electronic helmet 10 and the second communication unit 201 in the mobile device 20 are linked with each other, the electronic helmet 10 and the mobile device 20 start off receiving and transmitting signal. The dual-channel and audio-integrating active noise control program can start off executing after the three microphones 101 a , 101 b and 101 c respectively detect the noises d 1 (n), d 2 (n) and x(n). The noise x(n) together with the signals e 1 (n) and e 2 (n) will be respectively inputted into the filtering algorithm A, after the noise x(n) is processed with the secondary path frequency responses ล 11 (z) and ล 22 (z). The filtering algorithm A1 can adjust the two wave filters W 1 (z) and W 2 (z) in the program forms. Two adaptive wave filters W 1 (z) and W 2 (z) in the program forms respectively generate two control signals u 1 (n) and u 2 (n) after receiving the noise x(n). The control signals y 1 (n) and y 2 (n), which are generated by combining the signals u 1 (n) and u 2 (n) and sound of music, control the speakers 102 a and 102 b to output the anti-noises a 11 (n) and a 22 (n) that are received by the microphones 101 a and 101 b . Besides, the control signals y 1 (n) outputted by the speaker 102 a may be transmitted to the microphone 101 b (this frequency response shown as S 21 (z)) to generate sound a 21 (n). The control signals y 2 (n) outputted by the speaker 102 b may be transmitted to the microphone 101 a (this frequency response shown as S 12 (z)) to generate sound a 12 (n). Thus, signal q 1 (n) received by the microphone 101 a includes the anti-noise a 11 (n), the sound a 12 (n) and the noise d 1 (n). In the meantime, signal q 2 (n) received by the microphone 101 b includes the anti-noise a 22 (n), the sound a 21 (n) and the noise d 2 (n). After receiving the sound of music v(n), the estimated secondary path frequency responses ล 11 (z), ล 12 (z), ล 21 (z) and ล 22 (z) respectively output signals b 11 (n), b 12 (n), b 21 (n) and b 22 (n). Signal e 3 (n) will be generated by processing the signals q 1 (n) and b 11 (n). Similarly, signal e 4 (n) will be generated by processing the signals q 2 (n) and b 22 (n); signal e 2 (n) will be generated by processing the signals e 3 (n) and b 12 (n); and signal e 1 (n) will be generated by processing the signals e 4 (n) and b 21 (n). Next, the signals e 1 (n), e 2 (n), e 3 (n) and e 4 (n) are respectively inputted into inverter (K 1 , K 2 , K 3 and K 4 ), and then the inverter (K 1 , K 2 , K 3 and K 4 ) respectively output signals c 1 (n), c 2 (n), c 3 (n) and c 4 (n). Next, the signal c 1 (n) and the sound of music v(n) may be inputted into the filtering algorithm A 21 , the filtering algorithm A 21 will adjust the estimated frequency responses of secondary path ล 21 (n). In the meantime, the signal c 2 (n) and the sound of music v(n) may be inputted into the filtering algorithm A 12 , the filtering algorithm A 12 will adjust the estimated frequency responses of secondary path ล 12 (n); the signal c 3 (n) and the sound of music v(n) may be inputted into the filtering algorithm A 11 , the filtering algorithm A 11 will adjust the estimated frequency responses of secondary path ล 11 (n); and the signal c 4 (n) and the sound of music v(n) may be inputted into the filtering algorithm A 22 , the filtering algorithm A 22 will adjust the estimated frequency responses of secondary path ล 22 (n). The aforementioned process can be executed again after the next noises d 1 (n), d 2 (n) and x(n) are respectively detected by the four adjusted adaptive wave filters ล 11 (n), ล 12 (n), ล 21 (n) and ล 22 (n) together with the three microphones 101 a , 101 b and 101 c . In the embodiment, the filtering algorithm A 1 may be Filtered-X Least Mean Square algorithm, and the four filtering algorithms A 11 , A 12 , A 21 and A 22 may be Least Mean Square algorithm, but not limited to. The dual-channel and audio-integrating active noise control program of the embodiment is implemented by the control unit 202 in the mobile device 20 and generates the control signals y 1 (n), and y 2 (n) by combining the signals u 1 (n) and u 2 (n) with the sound of music v(n), in the light of the sound of music v(n) and the noises d 1 (n), d 2 (n) and x(n) detected by the microphones 101 a , 101 b and 101 c of the electronic helmet 10 . The speakers 102 a and 102 b of the electronic helmet 10 are controlled by the mobile device 20 with the control signals y 1 (n) and y 2 (n), output the anti-noises a 11 (n) and a 22 (n) that may cancel the noises d 1 (n), d 2 (n) and x(n), and retain the sound of music v(n).
FIG. 5 is a schematic flow diagram illustrating one embodiment of adaptive acoustic echo cancellation program according to the present invention. Please refer to FIG. 2 and FIG. 5 , one microphone 101 c in the electronic helmet 10 near user's mouse and the speaker 102 a in the electronic helmet 10 near user's ear are utilized as signal input or output devices for the adaptive acoustic echo cancellation program. The sound v 1 (n) of an answer is outputted by the speaker 102 a , influenced by acoustic media and converted into the noise x(n) in echo form. The sound v 1 (n) is combined with user's sound v 2 (n) to generate signal q(n), and then the signal q(n) is detected by the microphone 101 c near the user's mouse. Moreover, the sound v 1 (n) is inputted into the adaptive filter W 3 (z) in program form, and then the adaptive filter W 3 (z) can generate signal y(n). Next, the sound e(n) without echo interference is generated after signals q(n) and y(n) are processed, and then transferred into the answer's ear. The sound e(n) and the answer's sound v 1 (n) are inputted into a filtering algorithm A 3 for adjusting the adaptive filter W 3 (z). The aforementioned process can be executed again after the microphone 101 c continuously detects user's next sound v 2 (n) and the noise x(n) that results from echo. In the embodiment, the filtering algorithm A3 may be a Least Mean Square algorithm, but not limited to. The adaptive acoustic echo cancellation program of the embodiment is implemented by the control unit 202 in the mobile device 20 and generates the control signal y(n) in the light of the sound v 2 (n) and the noise x(n) that are detected by the microphone 101 c in the electronic helmet 10 and the voice signal v 1 (n) of a remote answer outputted by the speaker 102 a . Then the sound e(n) without echo interference can be generated and transmitted to the remote answer through the mobile device 20 .
Accordingly, the electronic helmet of the present invention includes the control unit 202 to have functions as follows: (1) the active noise control program used to cancel snore and noise; (2) the dual-channel and audio-integrating active noise control program used to cancel snore and noise but retain sound such as music; and (3) adaptive acoustic echo cancellation program used to cancel echo resulted from telecommunication.
Next, the electronic helmet of the present invention includes the control unit 202 to have voice navigation function. User speaks out a destination with his or her sound that is detected by the microphone 101 c near the user's mouse. The control unit 202 of the mobile device 20 fixes the user's location and make a route plan to be outputted by the speakers 102 a and 102 b near the user's ears.
The method for noise cancellation is illustrated as follows.
FIG. 6 is a schematic flow diagram illustrating a method of snore and noise cancellation according to the present invention. Shown in FIG. 6 , step 301 : user launches the electronic helmet 10 and the control unit 202 in the mobile device 20 , and the second communication unit 201 in the mobile device 20 may be automatically launched by the control unit 202 ; step 302 : the second communication unit 201 in the mobile device 20 is connected with the first communication unit 103 in the electronic helmet 10 ; step 303 : multitudes of the microphones 101 in the electronic helmet 10 at least detect the sound or the noise; step 304 : the control unit 202 in the mobile device 20 generates multitudes of control signals in the light of at least the sound or the noise detected by the microphones 101 in the electronic helmet 10 ; and step 305 : with the control signals, the mobile device 20 controls multitudes of the speakers 102 in the electronic helmet 10 to at least output the sound or anti-noise.
Accordingly, an electronic helmet of snore and noise cancellation is provided, which includes: the electronic helmet 10 having multitudes of the microphones 101 , multitudes of the speakers 102 and the first communication unit 103 ; and the mobile device 20 having the second communication unit 201 and the control unit 202 . If the first communication unit 103 of the electronic helmet 10 and the second communication unit 201 of the mobile device 20 are connected, the control unit 202 generates multitudes of control signals in the light of the sound or noise detected by the microphones 101 , and the mobile device 20 controls the speakers 102 with the control signal to output the sound or/and anti-noise that may cancel out the noise. With the electronic helmet, a method of integrating active noise control, hand-free communication, music listening, and voice navigation is also provided for the purposes for noise cancellation and improvement on riding quality.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
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The present invention provides an electronic helmet for cancelling noises, which comprises a helmet including a plurality of microphones, a plurality of speakers and a first communication unit; and a mobile device including a second communication unit and a control unit. When the first communication unit in the helmet connects to the second communication unit in the mobile device, the control unit generates a plurality of control signals according to at least one sound or noise detected by the plurality of microphones. The mobile device uses the plurality of control signals to control the plurality of speakers outputting the at least one sound or anti-noise cancelling the noise. By the above electronic helmet, the present invention also provides a method integrating active noise control, hands-free communication, music listening, and voice navigation so as to achieve the proposes of cancelling the noises and improving the riding quality.
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This application is the national phase under 35 U.S.C. ยง371 of PCT International Application No. PCT/KR99/00264 which has an International filing date of May 28, 1999, which designated the United States of America and was published in English.
FIELD OF THE INVENTION
The present invention relates to novel cathecol hydrazone derivatives which inhibit the enzymatic activity of phosphodiesterase IV or tumor necrosis factor. These compounds may be useful in prevention or treatment of bronchial asthma, arthritis, bronchitis, chronic atretic airway, psoriasis, allergic rhinitis, dermatitis, AIDS, Crohn's disease, septicemia, septic shock, other inflammatory diseases such as cachexia, TNF related diseases, etc. Also, the present invention relates to a method for producing said compounds and a pharmaceutical composition containing said compound.
BACKGROUND OF THE INVENTION
Phosphodiesterase IV is an enzyme that specifically hydrolyzes cAMP (cyclic adenosine 3โฒ,5โฒ-monophosphate) into inactive adenosine 3โฒ,5โฒ-monophosphate. The cAMP has been shown to be a second messenger mediating the cellular responses to external stimuli and to act as relaxing or contradicting bronchial muscles.
The inhibition of phosphodiesterase IV leads to the prevention of broncospasm by maintaining the concentration of cAMP and also induces an anti-inflammation. Therefore, compounds that inhibit phosphodiesterase IV should be effective in treating asthma and the like diseases.
It is known that tumor necrosis factor (TNF) is implicated in infectious disease such as cachexia and autoimmune disease. Also, TNF appears to act as a primary mediator for inflammatory reaction such as septicemia and septic shock.
Therefore, it is expected that compounds with the inhibitory activity against phosphodiesterase IV or TNF will be pharmaceutically valuable and there is always a need to develop new compounds which inhibit phosphodiesterase IV and TNF.
Many compounds have been suggested as inhibitors of phosphodiesterase IV and TNF. For example, EP 470,805 of American Home Product describes oximcarbamate and oximcarbonate of formula:
wherein R is C 3-7 alkyl or C 3-7 cycloalkyl, R 1 is halogen or lower alkyl, and R 2 is amino, lower alkylamino, arylamino, lower alkoxy or aryloxy.
U.S. Pat. No. 5,393,798 of SmithKline Beecham Corporation describes phenylalkyl oxamide compound of formula:
wherein R 1 is C 4-6 cycloalkyl, X is YR 2 halogen in which Y is oxgen or sulfur, or lower alkyl, R 3 and R 5 are independently OR 7 , R 4 is hydrogen or C 1-2 alkyl, R 6 is OR 7 or NR 7 OR 7 , and R 7 is hydrogen or C 1-3 alkyl.
SUMMARY OF THE INVENTION
The present invention provides novel cathecol hydrazone derivatives of formula I:
or pharmaceutically acceptable salts thereof, wherein
R 1 is C 1-7 alkyl or C 3-7 cycloalkyl;
R 2 is hydrogen, hydroxy, C 1-5 alkyl or โCH 2 CH 2 C(โO)NH 2 ;
R 3 and R 4 are independently hydrogen, C 1-7 alkyl, โC(โX)โR 5 , or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one or two selected from a group consisting of halogen, C 1-6 alkoxy, nitro, trifluoromethyl, C 1-6 alkyl and carboxyl, or R 3 and R 4 are directly bonded by C 3-4 containing oxygen, sulfur or nitrogen to form a heterocyclic ring, X is oxygen, sulfur or NH, and R 5 is C 1-7 alkyl, โNHR 6 , CONH 2 or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one selected from a group consisting of halogen, C 1-6 alkoxy, nitrile, trifluoromethyl, C 1-6 alkyl and carboxyl, and R 6 is hydrogen, hydroxy, NH 2 , C 1-5 alkoxy, C 1-5 alkyl, pyridyl or phenyl.
DETAILED DESCRIPTION OF THE INVENTION
The compound of formula I can be present as optical isomers or stereoisomers. Thus, the present invention includes such isomers and mixtures thereof.
The present invention provides a pharmaceutical composition for inhibiting phosphodiesterase IV or TNT which comprises a compound of formula I and a pharmaceutically acceptable carrier.
The compound of formula I can be prepared by the following reaction scheme I:
wherein R 1 , R 2 , R 3 and R 4 are the same as defined above.
Some derivatives were synthesized by a known method (J. Med. Chem., 1994, 37, 1696). Hydrazine compounds were synthesized in yield of 60% to 90% in alcohol solvent using acid catalyst (Tetrahedron Lett. 1994, 35, 3711).
The invention will now be described with reference to the following illustrative Examples.
EXAMPLES
Reference Example 1
3-cyclopentyloxy-4-methoxybenzaldehyde
A solution of 100 g (0.66 mol) of isovanillin, 136.2 g (0.99 mol) of anhydrous potassium carbonate, and 3 g of potassium iodide in 650 ml of anhydrous dimethylformamide was stirred at 65ยฐ C. 127.3 g (0.85 mol) of cyclopentyl bromide was slowly added dropwise for 1 hour to the solution. This solution was stirred at 65ยฐ C. for 1 day and, then, its temperature was lowered to a room temperature. It was diluted by 2.0 L of toluene and was washed with 1M sodium hydroxide (2ร1.5 L). The aqueous layer was extracted with 0.5 L of toluene, and the organic layer was washed with distilled water (2ร1.5 L). The organic layer was dried and concentrated to obtain 117 g of light brown oily title compound. 1 H NMR(CDCl 3 ,d): 9.84(s, 1H) 7.42(m, 2H) 6.95(d, 1H, J=9 Hz) 4.87(m, 1H) 3.93(s, 3H) 2.1-6(m, 8H)
Example 1
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde isonicotinic hydrazone
A catalytic amount of concentrated sulfuric acid was added to a solution of 0.44 g (2.0 mmole) of compound prepared by Reference Example 1 in 30 ml of ethanol and the mixture was stirred at room temperature for 10 minutes. 0.33 g of isonicotinic hydrazide was added to the reaction solution. The solution was stirred at 50ยฐ C. for 4 hours and was concentrated under reduced pressure. The residue was dissolved in dichloromethane and was washed twice with 50 ml of distilled water. The separated organic layer was dried over anhydrous magnesium sulfate and was distilled under reduced pressure. The resulting white crystal was recrystalized in dichloromethane to obtain 0.67 g (88.45%) of white title compound. m.p. 170-171ยฐ C. 1 H NMR(DMSO-d6): 1.60(2H, m) 1.75(4H, m) 1.92(2H, m) 3.81(3H, s) 4.85(1H, m) 7.04(1H, d J=8.4 Hz) 7.24(1H, dd, J=8.4, 1.8 Hz) 7.33(1H, d J=1.8 Hz) 7.81(2H, dd J=4.5, 1.6 Hz) 8.39(1H, s) 8.78(2H, dd, J=4.5, 1.6 Hz) 11.92(1H, s)
Example 2
(E)-ethyl[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinoformate
A catalytic amount of concentrated hydrochloric acid was added to a solution of 1.00 g (4.54 mmole) of compound prepared by Reference Example 1 in 80 ml of ethanol and the mixture was stirred at room temperature for 10 minutes. 0.73 g of ethyl carbazate was added to the reaction solution. The solution was stirred at 50ยฐ C. for 4 hours and was concentrated under reduced pressure. The residue was dissolved in dichloromethane and was washed twice with 50 ml of distilled water. The separated organic layer was dried over anhydrous magnesium sulfate and was distilled under reduced pressure. The resulting white crystal was recrystallized in dichloromethane to obtain 1.25 g (89.87%) of white title compound. m.p. 146-147ยฐ C. 1 H NMR(DMSO-d6): 1.23(3H, t, J=7.1 Hz) 1.58(2H, m) 1.73(4H, m) 1.88(2H, m) 3.77(3H, s) 4.13(2H, q, J=7.1 Hz) 4.80(1H, m) 6.98(1H, d J=8.4 Hz) 7.07(1H, dd, J=8.4, 1.9 Hz) 7.20(1H, d J=1.9 Hz) 7.93(1H, s) 10.92(1H, s)
Example 3
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde phenylhydrazone
A catalytic amount of concentrated hydrochloric acid was added to a solution of 0.50 g (2.27 mmole) of compound prepared by Reference Example 1 in 60 ml of ethanol and the mixture was stirred at room temperature for 10 minutes. 0.34 ml of phenylhydrazine was added to the reaction solution. The solution was stirred at 50ยฐ C. for 10 hours. The resulting precipitate was filtered and washed with 20 ml of ethanol to obtain 0.63 g (89.41%) of white title compound. m.p. 138-140ยฐ C. 1 H NMR(DMSO-d6): 1.60(2H, m) 1.75(4H, m) 1.92(2H, m) 3.77(3H, s) 4.85(1H, m) 6.72(1H, m) 6.95(1H, d J=8.2 Hz) 7.03(2H, d, J=7.6 Hz) 7.09(1H, dd, J=8.2, 1.8 Hz) 7.20(2H,t) 7.26(1H, d J=1.8 Hz) 7.78(1H, s) 10.12(1H, s)
Example 4
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde acetic hydrazone
A catalytic amount of concentrated hydrochloric acid was added to a solution of 0.50 g (2.27 mmole) of compound prepared by Reference Example 1 in 60 ml of ethanol and the mixture was stirred at room temperature for 10 minutes. 0.26 g of acetic hydrazide was added to the reaction solution. The solution was stirred at 25ยฐ C. for 10 hours and was concentrated under reduced pressure. The residue was dissolved in dichloromethane and was washed twice with 50 ml of distilled water. The separated organic layer was dried over anhydrous magnesium sulfate and was distilled under reduced pressure. The resulting white crystal was recrystallized in dichloromethane to obtain 0.59 g (94.06%) of white title compound. m.p. 155-156ยฐ C. 1 H NMR(DMSO-d6): 1.58(2H, m) 1.71(4H, m) 1.88(2H, m) 2.18(3H, s) 3.78(3H, s) 4.81(1H, m) 6.99(1H, d J=8.4 Hz) 7.14(1H, dd, J=8.4, 1.8 Hz) 7.24(1H, d J=1.8 Hz) 7.88(1H, s) 11.12(1H, s)
Example 5
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde 7-chloroquinolone-4-ylhydrazone
A catalytic amount of concentrated hydrochloric acid was added to a solution of 0.50 g (2.27 mmole) of compound prepared by Reference Example 1 in 60 ml of ethanol and the mixture was stirred at room temperature for 10 minutes. 0.67 g of 7-chloro-4-hydrazinoquinoline was added to the reaction solution. The solution was stirred at 45ยฐ C. for 10 hours. The resulting precipitate was filtered and washed with 20 ml of ethanol to obtain 0.55 g (61.20%) of white title compound. m.p. 210-212ยฐ C. 1 H NMR(DMSO-d6): 1.61(2H, m) 1.78(4H, m) 1.94(2H, m) 3.81(3H, s) 4.89(1H, m) 7.04(1H, d J=8.3 Hz) 7.28(1H, dd, J=8.3, 1.8 Hz) 7.36(1H, d J=5.2 Hz) 7.42(1H, d J=1.8 Hz) 7.61(1H, d) 7.86(1H, s) 8.39(1H, s) 8.44(2H, d J=9.1 Hz)
Example 6
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde 2-imidazolinohydrazone
A catalytic amount of concentrated hydrochloric acid was added to a solution of 0.50 g (2.27 mmole) of compound prepared by Reference Example 1 in 50 ml of ethanol and the mixture was stirred at room temperature for 10 minutes. 0.63 g of hydrozino-2-imidazoline hydrobromide was added to the reaction solution. The solution was stirred at 45ยฐ C. for 8 hours and was concentrated under reduced pressure. The residue was dissolved in dichloromethane and was washed twice with 50 ml of distilled water. The separated organic layer was dried over anhydrous magnesium sulfate and was distilled under reduced pressure. The resulting light yellow oil was purified by a flash chromatography (silica gel, 7.5% methanol-dichloromethane as a developing solution) to obtain 0.45 g (65.56%) of white title compound. m.p. 87-90ยฐ C. 1 H NMR(DMSO-d6): 1.61(2H, m) 1.72(4H, m) 1.89(2H, m) 3.70(4H, s) 3.79(3H, s) 4.89(1H, m) 7.01(1H, d J=8.4 Hz) 7.24(1H, dd, J=8.4, 1.8 Hz) 7.44(1H, d J=1.8 Hz) 8.06(1H, s)
Example 7
(E)-2-[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinecarboxamide
A reaction as in Example 6 was carried out using 0.50 g (2.27 mmole) of compound prepared in Reference Example 1 as a starting material to obtain 0.47 g (74.66%) of white title compound. m.p. 144-146ยฐ C. 1 H NMR(DMSO-d6): 1.58(2H, m) 1.71(4H, m) 1.89(2H, m) 3.76(3H, s) 4.92(1H, m) 6.44(2H, brs) 6.93(1H, d J=8.3 Hz) 7.09(1H, dd, J=8.3, 1.9 Hz) 7.36(1H, d J=1.9 Hz) 7.75(1H, s) 10.08(1H, s)
Example 8
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde 2-nitrophenylhydrazone
A reaction as in Example 3 was carried out using 0.50 g (2.27 mmole) of compound prepared in Reference Example 1 as a starting material to obtain 0.63 g (78.09%) of red yellow title compound. m.p. 135ยฐ C. (decomposed) 1 H NMR(DMSO-d6): 1.61(2H, m) 1.77(4H, m) 1.94(2H, m) 3.80(3H, s) 4.88(1H, m) 6.89(1H, m) 7.03(1H, d J=8.4 Hz) 7.22(1H, dd, J=8.4, 1.9 Hz) 7.35(1H, d J=1.9 Hz) 7.66(1H, t J=1.6 Hz) 7.95(1H, d J=8.7 Hz) 8.11(1H, dd J=8.5, 1.4 Hz) 8.39(1H, s) 11.15(1H, s)
Example 9
(E)-2-[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinecarbothioamide
A reaction as in Example 6 was carried out using 1.00 g (4.54 mmole) of compound prepared in Reference Example 1 as a strating material to obtain 0.94 g (70.57%) of white title compound. m.p. 112-114ยฐ C. 1H NMR(DMSO-d6): 1.57(2H, m) 1.71(4H, m) 1.88(2H, m) 3.76(3H, s) 4.91(1H, m) 6.44(2H, brs) 6.93(1H, d J=8.4 Hz) 7.09(1H, dd, J=8.4, 1.9 Hz) 7.36(1H, d J=1.9 Hz) 7.74(1H, s) 10.06(1H, s)
Example 10
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde 4chlorophenylhydrazone
A reaction as in Example 6 was carried out using 1.50 g (6.81 mmole) of compound prepared in Reference Example 1 as a starting material to obtain 1.65 g (70.26%) of white title compound. m.p. 133-135ยฐ C. 1 H NMR(DMSO-d6): 1.60(2H, m) 1.76(4H, m) 1.91(2H, m) 3.78(3H, s) 4.86(1H, m) 6.97(1H, d J=8.4 Hz) 7.04(2H, dd J=6.8, 2.1 Hz) 7.12(1 H, dd, J=8.4, 1.9 Hz) 7.24(2H, dd J=6.8, 2.1 Hz) 7.27(1H, d J=1.9 Hz) 7.87(1H, s) 10.27(1H, s)
Example 11
(E)-2[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinecarbonylmethyl(trimethyl)ammonium chloride
A reaction as in Example 6 was carried out using 1.50 g (6.81 mmole) of compound prepared in Reference Example 1 and 1.03 g of (carboxymethyl)trimethylammonium chloride hydrazide as starting materials to obtain 1.73 g (68.68%) of white title compound. m.p. 178-179ยฐ C. 1 H NMR(DMSO-d6): 1.60(2H, m) 1.73(4H, m) 1.90(2H, m) 3.30(9H, s) 3.79(3H, s) 4.33(2Ha, s) 4.79(2Ha, s) 4.84(1H, m) 7.03(1H, d J=8.4 Hz) 7.23(1H, dd, J=8.4, 1.8 Hz) 7.29(1H, d J=1.8 Hz) 8.01(1Haโฒ,s) 8.26(1Haโฒ, s) 12.05(1H, brs)
Example 12
(E)-N-(1,4-oxazine-4-yl)-3-cyclopentyloxy-4-methoxyphenylmethaneimine
5.0 g (22.7 mmole) of compound prepared by Reference Example 1 was dissolved in 60 ml of ethanol and the resulting solution was stirred at room temperature for 10 minutes. 2.91 ml of N-aminomorpholine was added to the reaction solution. The solution was stirred at 5ยฐ C. for 14 hours. The resulting precipitate was filtered and washed with 20 ml of ethanol to obtain a while solid. This solid was recrystallized in isopropylether to obtain 6.37 g (92.19%) of title compound. m.p. 108-109ยฐ C. 1 H NMR(DMSO-d6): 1.56(m, 2H) 1.70(m, 4H) 1.88(m, 2H) 3.03(m, 4H) 3.67(m, 7H) 4.77(m, 1H) 6.88(d, 1H) 7.04(dd, 1H) 7.18(d, 1H) 7.62(s, 1H)
Example 13
(E)-N-piperidino-3-cyclopentyloxy-4-methoxyphenylmethaneimine
A reaction as in Example 12 was carried out using 0.50 g (2.27 mmole) of compound prepared in Reference Example 1 and 0.31 ml of N-aminopiperidine as starting materials to obtain 0.65 g (94.68%) of white title compound. m.p. 81-82ยฐ C. 1 H NMR(DMSO-d6): 1.52(m, 4H) 1.67(m, 8H) 1.90(m, 2H) 3.04(m, 4H) 3.70(s, 3H) 4.76(m, 1H) 6.89(d, 1H) 7.04(dd, 1H) 7.i8(d, 1H) 7.57(s, 1H)
Example 14
(E)-2-[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinecarboximidamide
A reaction as in Example 6 was carried out using 1.50 g (6.81 mmole) of compound prepared in Reference Example 1 and 0.73 g of aminoguanidine hydrochloride as starting materials to obtain 1.60 g (85.02%) of white title compound. m.p. 100-103ยฐ C. 1 H NMR(DMSO-d6): 1.62ห1.64(2H, m) 1.74ห1.78(4H, m) 1.94ห1.97(2H, m) 3.84(3H, s) 4.95ห4.98(1H, m) 7.05(1H, d J=8.4 Hz) 7.33(1H, dd, J=8.4, 2.0 Hz) 7.54(1H, d J=1.9 Hz) 7.7(1H, brs) 8.36(1H, s) 11.69(1H, s)
Example 15
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde 2-pyridinylhydrazone
A reaction as in Example 6 was carried out using 0.80 g (3.63 mmole) of compound prepared in Reference Example 1 and 0.39 g of 2-hydrazinopyrimidine as starting materials to obtain 0.96 g (84.89%) of white title compound. m.p. 142-143 ยฐ C. 1 H NMR(DMSO-d6): 1.58ห1.61 (2H, m) 1.71 ห1.76(4H, m) 1.89ห1.94(2H, m) 3.77(3H, s) 4.84ห4.87(1H, m) 6.73ห6.74(1H, m) 6.97(1H, d J=8.3 Hz) 7.10(1H, dd, J=8.3, 1.8 Hz) 7.20(1H, d J=8.4 Hz)7.27(1H, d J=1.8 Hz) 7.62ห7.63(1H, m) 7.94(1H, s) 8.09(1H, dd J=4.9, 1.0 Hz) 10.67(1H, s)
Example 16
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde 2-carboxyphenylhydrazone
A reaction as in Example 6 was carried out using 0.80 g (3.63 mmole) of compound prepared in Reference Example 1 and 0.66 g of 2-hydrazinobenzoic hydrochloride as starting materials to obtain 1.05 g (81.57%) of white title compound. m.p. 174-176ยฐ C. 1 H NMR(DMSO-d6): 1.59ห1.60(2H, m) 1.71ห1.76(4H, m) 1.92ห1.93(2H, m) 3.78(3H, s) 4.85(1H, m) 6.78(1H, dd J=7.0, 1.0 Hz) 6.99(1H, d J=8.4 Hz) 7.20(1H, dd, J=8.4, 1.9 Hz) 7.32(1H, d J=1.9 Hz) 7.50(1H, dd J=7.0, 1.6 Hz) 7.68(1H, dd J=8.5, 0.8 Hz) 7.84(1H, dd J=8.0, 1.4 Hz) 8.05(1H, s) 8.79(1H, d J=4.9 Hz) 11.17(1H, s)
Example 17
(E)-3-cyclopentyloxy-4-methoxybenzaldehyde 4-trifluoromethylpyrimidin-2-ylhydrazone
A reaction as in Example 6 was carried out using 0.80 g (3.63 mmole) of compound prepared in Reference Example 1 and 0.63 g of 2-hydrazino-4-(trifluoromethyl)pyrimidine as starting materials to obtain 1.10 g (79.62%) of white title compound. m.p. 73-75ยฐ C. 1 H NMR(DMSO-d6): 1.58ห1.59(2H, m) 1.72ห1.76(4H, m) 1.89(2H, m) 3.79(3H, s) 4.81ห4.84(1H, m) 7.01(1H, d J=8.4 Hz) 7.19(1H, dd, J=8.4, 2.0 Hz) 7.21(1H, d J=4.9 Hz) 7.27(1H, d J=2.0 Hz) 8.11(1H, s) 8.79(1H, d J =4.9 Hz) 1.67(1H, s)
Example 18
(E)-2-[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinecarbohydrazine
A catalytic amount of glacial acetic acid was added to a solution of 1.0 g (4.54 mmol) of compound prepared in Reference Example 1 in 50 ml of methanol and the mixture was stirred at room temperature for 10 minutes and added dropwise over 20 minutes to a solution of 1.0 g of carbohydrazine in 50 ml of distilled water. The reaction mixture was stirred at room temperature for 1 hour and the precipitated solids were filtered to obtain 0.89 g (67.06%) of white title compound. m.p. 179-181ยฐ C. 1 H NMR(DMSO-d 6 ): 1.61(2H, m) 1.72(4H, m) 1.89(2H, m) 3.76(3H, s) 4.05(2H, brs) 4.94(1 H,m) 6.92(1H, d J=8.3 Hz) 7.07(1H, dd, J=8.3, 1.7 Hz) 7.42(1H, d J=1.6 Hz) 7.74(1H, s) 8.03(1H,s) 10.23(1H,s)
Example 19
(E)-2-[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinedicarboxamide
A catalytic amount of glacial acetic acid was added to a solution of 1.0 g (4.54 mmol) of compound prepared in Reference Example 1 in 50 ml of methanol and the mixture was stirred at room temperature for 10 minutes and added dropwise over 30 minutes to a solution of 1.17 g of oxamic hydrazide in 60 ml of distilled water. The reaction mixture was stirred at room temperature for 2 hours and the precipitated solids were filtered to obtain 1.12 g (80.80%) of white title compound. m.p. 233-235ยฐ C. 1 H NMR(DMSO-d 6 ): 1.57(2H, m) 1.71(4H, m) 1.87(2H, m) 3.76(3H, s) 4.11(2H, brs) 4.95(1H,m) 6.91(1H, d J=8.5 Hz) 7.28(1H, dd, J=8.5, 2.2 Hz) 7.42(1H, d J=2.1 Hz) 7.83(1H, s) 9.32(1H,s)
Example 20
(E)-2-[(3-cyclopentyloxy-4-methoxyphenyl)methylene]hydrazinoacetic acid
A reaction as in Example 6 was carried out using 0.80 g (3.63 mmole) of compound prepared in Reference Example 1 and 0.63 g of ethylhydrazinoacetate as starting materials to obtain 0.98 g of white ethyl (E)-2-[3-cyclopentyloxy-4-methoxyphenylmethylene]hydrazinoacetate. The prepared ester compound was hydrolysed in the mixture of methanol and 1.0 N aqueous sodium hydroxide solution to afford 0.75 g (70.77%) of white title solid. m.p. 165ยฐ C. (decomposed) 1 H NMR(DMSO-d 6 ): 1.59(2H, m) 1.71(4H, m) 1.87(2H, m) 3.74(3H, s) 3.83(2H, brs) 4.77(1H,m) 6.90(1H, d J=8.5 Hz) 6.96(1H, dd, J=8.3, 1.7 Hz) 7.09(1H, d J=1.7 Hz) 7.57(1H, s)
Experimental Example
Inhibition of Phosphodiesterase IV Activity
Compounds prepared by Examples 1 through 16 and Rolipram as control were tested on the inhibition of phosphodiesterase IV.
Phosphodiesterase IV partially purified from human U937 cells, test compound and 1.0 uM cAMP including 0.01 uM[ 3 H]cAMP were incubated at 30ยฐ C. for 20 minutes. The PDE reaction to convert cAMP into AMP was completed by boiling the reaction solution for 2 minutes. AMP was converted into adenosine by adding snake venom nucleotidase and incubating the reaction solution at 30ยฐ C. for 10 minutes. While unhydrolyzed cAMPs were bonded to AG1-X2 resin, the [ 3 H]adenosine in the aqueous solution was quantified by scintillation counting. The results are shown in Table I below, in which the values indicate inhibition (%) of the PDE IV by each test compound.
TABLE I
Test Compounds
Concentration (uM)
Inhibition (%)
Rolipram (Control)
20
70.1
2
62.5
EXAMPLE 1
20
66.7
2
38.4
EXAMPLE 2
20
63.7
2
46.7
EXAMPLE 3
20
80.4
2
46.6
EXAMPLE 4
20
72.1
2
51.7
EXAMPLE 5
20
64.9
2
37.9
EXAMPLE 6
20
58.3
2
31.7
EXAMPLE 7
20
89.7
2
66.2
EXAMPLE 9
20
81.0
2
69.0
EXAMPLE 10
20
70.7
2
39.3
EXAMPLE 11
20
45.1
2
43.3
EXAMPLE 12
20
79.4
2
62.9
EXAMPLE 13
20
73.3
2
31.4
EXAMPLE 14
20
57.7
2
14.7
EXAMPLE 15
20
63.6
2
49.4
EXAMPLE 16
20
76.6
2
42.3
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The present invention provides novel cathecol hydrazone derivatives of formula (I) or pharmaceutically acceptable salts thereof, wherein R 1 is C 1-7 alkyl or C 3-7 cycloalkyl; R 2 is hydrogen, hydroxy, C 1-5 alkyl or โCH 2 CH 2 C(โO)NH 2 ; R 3 and R 4 are independently hydrogen, C 1-7 alkyl, โC(โX)โR 5 , or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one or two selected from a group consisting of halogen, C 1-6 alkoxy, nitro, trifluoromethyl, C 1-6 alkyl and carboxyl, or R 3 and R 4 are directly bonded by C 3-4 containing oxygen, sulfur or nitrogen to form a heterocyclic ring, X is oxygen, sulfur or NH and R 5 is C 1-7 alkyl, โNHR 6 , CONH 2 or 2-, 3- or 4-pyridyl, prymidyl or phenyl substituted with one selected from a group consisting of halogen, C 1-6 alkoxy, nitrile, trifluoromethyl, C 1-6 alkyl and carboxyl, and R 6 is hydrogen, hydroxy, NH 2 , C 1-5 alkoxy, C 1-5 alkyl, pyridyl or phenyl.
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FIELD OF THE INVENTION
The present invention relates to the field of tristate output buffers. In particular, the present invention relates to the field of CMOS tristate output buffers capable of tolerating overvoltages during tristate mode without reverse currents or latch-up.
BACKGROUND OF THE INVENTION
Advances in integrated circuit fabrication technology continue to enable greater numbers of CMOS logic devices to be formed on a single integrated circuit chip. One change which has been found necessary to implement the higher density CMOS devices has been to reduce the power supply voltage driving the chip. For example, a power supply voltage VDD of 3.3 volts is common in present state of the art CMOS logic devices.
Low voltage CMOS memory devices must often be operatively interconnected with external 5-volt devices such as TTL devices. Generally, a 3.3 volt CMOS device is capable of driving 5-volt TTL devices attached to a data bus, provided that the CMOS device can generate sufficient current at its output pad. Such CMOS devices are usually provided with a tristate output buffer having a large P-channel driver transistor capable of providing sufficient current at the output pad at 3.3 volts. The tristate output buffer is also provided with a relatively large N-channel pulldown transistor capable of sinking sufficient current to drive the data bus to zero volts in a timely manner. During tristate or high impedance mode, the tristate output buffer causes the CMOS device to appear transparent to the line or output terminal to which it is connected. This is achieved by turning off both the P-channel driver transistor and the N-channel pulldown transistor so that a high input impedance is seen at the output pad.
FIG. 1 shows a standard CMOS tristate output buffer 100 according to the prior art. Tristate output buffer 100 comprises a P-channel driver transistor P1, an N-channel pulldown transistor N1, and predriver circuitry 101. P-channel driver transistor P1 comprises a gate coupled to a node VP, while N-channel pulldown transistor N1 comprises a gate coupled to a node VN. Predriver circuitry 101 is coupled to nodes VP and VN as shown in FIG. 1. Tristate output buffer 100 further comprises a node OE for receiving an output enable signal, as well as a node D for receiving a data signal. The signals at nodes OE and D are typically provided by low-voltage CMOS core logic circuitry (not shown). Tristate output buffer 100 also comprises an output node VPAD for coupling to an external data bus (not shown), to which various external devices, such as TTL devices or other CMOS devices, are connected. Tristate output buffer 100 comprises a node VDD for receiving a standard CMOS power supply voltage, such as 3.3 volts, at the source of P-channel driver transistor P1. Finally, tristate output buffer 100 comprises a node GND for receiving a ground voltage. For simplicity and clarity of disclosure, "VDD" will represent both the node VDD and the power supply voltage provided at node VDD. Likewise, "GND" or "ground" will represent both the node GND and the ground voltage provided at node GND.
As is well known in the art, tristate output buffer 100 is designed to drive a voltage at node VPAD according to the logic values represented by the voltages at nodes OE and D. When OE is high, the term "high" usually signifying a voltage above a low-voltage CMOS logic threshold, the tristate output buffer is in a "drive" or "output enable" mode. Thus, when OE is high and D is high, the voltage at node VPAD is driven to VDD. When OE is high and D is low, the term "low" usually signifying a voltage below the low-voltage CMOS logic threshold, the voltage at node VPAD is driven to ground.
In contrast, when OE is low, the tristate output buffer is in a "tristate" or "high impedance" mode. Tristate mode occurs when the low voltage CMOS core logic circuitry associated with the tristate output buffer 100 is not driving the bus. Instead, the low-voltage CMOS core logic circuitry is either (1) receiving data from the bus at node VPAD (using input circuitry not shown) or (2) is not involved in any transactions occurring on the bus. In this circumstance, it is desired for the tristate output buffer 100 to have a high input impedance for avoiding unnecessary current sinks and for reducing overall bus inductance and capacitance. The voltage at node D does not affect the voltage at node VPAD when OE is low.
In conventional CMOS integrated circuits, large N-wells are formed on p-type substrates, and PMOS transistors are formed in these N-wells. Typically, all of the P-channel transistors of the tristate output buffer 100 are formed in a common N-well and have substrate or terminals that are electrically integral with or connected to the N-well. This is not explicitly shown in the present drawings, but is described and illustrated in U.S. Pat. No. 5,338,978, issued Aug. 16, 1994 to Larsen et al., entitled FULL SWING POWER DOWN BUFFER CIRCUIT WITH MULTIPLE POWER SUPPLY ISOLATION, the disclosure of which is incorporated herein by reference.
Several problems can occur when the tristate output buffer 100 of FIG. 1 is used to drive a data bus which can be driven to high voltages (5.0 v) by other devices such as TTL devices. Specifically, the following problems can occur when the voltage at node VPAD exceeds the N-well voltage during tristate mode. First, a reverse leakage current through the P-channel driver transistor P1, from node VPAD to VDD, may occur due to a forward biasing of the drain of transistor P1 with respect to its gate. Second, latch-up may occur in a parasitic silicon controlled rectifier formed by (1) a parasitic PNP transistor having the p+ drain of P1 as its emitter, the N-well as its base, and the p-substrate as its collector, and (2) a parasitic NPN transistor having the n+ body terminal of P1 as its collector, the p-substrate as its base, and a neighboring n+ terminal as its emitter. Third, excessively high stress voltages may occur across the gate oxides of various buffer transistors, including the P-channel driver transistor P1. These problems are discussed more fully in U.S. Pat. No. 5,444,397, issued Aug. 22, 1995 to Wong et al., titled ALL-CMOS HIGH-IMPEDANCE OUTPUT BUFFER FOR A BUS DRIVEN BY MULTIPLE POWER-SUPPLY VOLTAGES, the disclosure of which is incorporated herein by reference.
FIG. 2 shows an exemplary circuit known in the art for resolving at least some of these problems. FIG. 2 shows a tristate output buffer 200 similar to that shown in FIG. 1, with the addition of an N-well bias circuit 204 and a gate bias circuit 206. The purpose of the elements 204 and 206 is to implement feedback circuits causing the N-well and gate of the P-channel driver transistor P1 to follow the voltage at node VPAD during tristate mode when this voltage exceeds VDD. If VPAD does not exceed VDD during tristate mode, the N-well and gate voltages are maintained at VDD. In this manner, the drain of transistor P1 does not become forward biased with respect to its gate or the N-well, thus eliminating reverse leakage current. Furthermore, because the gate bias circuit 206 generally biases gate node VP to a voltage substantially equal to the voltage at which N-well bias circuit 204 biases the N-well, excessive oxide stresses are reduced.
Examples of tristate buffer circuits incorporating elements analogous to element 204, element 206, or both, are disclosed in U.S. Pat. No. 5,160,855, issued Nov. 3, 1992 to Dobberpuhl, titled FLOATING-WELL CMOS OUTPUT DRIVER, U.S. Pat. No. 5,467,031, issued Nov. 14, 1995 to Nguyen et al., titled 3.3 VOLT CMOS TRI-STATE DRIVER CIRCUIT CAPABLE OF DRIVING COMMON VOLT LINE, and U.S. Pat. No. 5,396,128, issued Mar. 7, 1995 to Dunning et al., titled OUTPUT CIRCUIT FOR INTERFACING INTEGRATED CIRCUITS HAVING DIFFERENT POWER SUPPLY POTENTIALS, the disclosures of which are incorporated herein by reference.
A problem, however, exists in prior art gate bias and N-well bias circuits in CMOS tristate output buffers. Specifically, the circuits are not stabilized with respect to variations of the voltage at VPAD near VDD during tristate mode. Such a variation may include an unstable high voltage transient occurring on the data bus during tristate mode. In prior art devices, the circuits represented by N-well bias circuit 204 and gate bias circuit 206 will cause an unstable switching of the bias voltages back and forth between nodes VDD and VPAD when VPAD hovers near VDD. This is because the devices include only "combinational" logic, in which the present output (i.e., the bias voltage) is only a function of the present value of VDD with respect to VPAD. For example, as the present value of VPAD crosses over some combinational logic threshold voltage VT* during tristate, the bias circuits will cease coupling the N-well and gate to VDD and will instead couple these nodes to VPAD. As the present value of VPAD crosses back below this same combinational logic threshold voltage VT*, the bias circuits will then switch back from VPAD to VDD.
Driver transistors contained within the N-well bias circuit 204 and/or gate bias circuit 206 need relatively large transistors (although not as large as P-channel driver transistor P1) sufficient to speedily switch the large N-well and gate nodes of P1 between VDD and VPAD. It has been found that it is not desirable to over-switch these bias circuit transistors unnecessarily, such as when a high voltage transient on the data bus occurs near VDD during tristate mode. The negative effects of such over-switching include unnecessary heating and high-frequency system noise.
Another problem which arises in the context of the circuit of FIG. 2 is related to the predriver circuitry 202. Because the P-channel driver transistor P1 is generally large, it is desirable for the predriver circuitry 202 to be capable of driving the gate of transistor P1 with a relatively large driving current at node VP', and hence at node VP, when P-channel driver transistor P1 is to be turned off. It is also desirable for the predriver circuitry 202 to be capable of sinking a relatively large amount of current from node VP', and hence node VP, when P-channel driver transistor is to be turned off.
FIG. 2A shows one way of achieving the large driving and sinking currents for the gate of P-channel predriver transistor P1, which is to drive VP' with a predriver stage inverter comprising a pullup transistor P2 and a pulldown transistor N2. Shown in FIG. 2A is a circuit 202A for generating the signal VN and the appropriate driving signal for driving the gates of transistors P2 and N2. This supplies adequate driving and sinking current when transistors P2 and N2 are appropriately sized.
However, when used in combination with the circuit of FIG. 2, the circuit of FIG. 2A experiences an undesirable reverse current problem. In particular, in the circumstance in which gate bias circuit 206 drives the node VP to VPAD during tristate when VPAD exceeds VDD, node VP' will often be driven to this voltage as well. Using an exemplary value of VDD as 3.3 volts and VPAD being driven to 5.0 volts, there then exists the situation where the gate of transistor P2 is at VDD=3.3 volts, the drain of P2 is at VP'=5.0 volts, and the source of P2 is at 3.3 volts. In this situation, a large and potentially destructive reverse current through transistor P2 can be experienced.
It is therefore an object of the present invention to provide a CMOS tristate output buffer capable of withstanding an overvoltage at its output pad during tristate mode.
It is another object of this invention to provide circuitry for biasing the N-well and gate of the P-channel driver transistor of the CMOS tristate output buffer such that reverse leakage current, latchup, and excessive oxide stresses are avoided during tristate overvoltage conditions.
It is another object of the present invention to provide circuitry which provides high-speed multiplexing of the bias voltage between the output pad voltage and VDD, for biasing the N-well and gate of the P-channel driver transistor to the appropriate values.
It is yet another object of the present invention to provide circuits for biasing the N-well and gate of the P-channel driver transistor with increased stability during tristate mode against variations in the output pad voltage taking place near VDD, including high voltage transients occurring on the data bus.
It is still another object of the present invention to provide a circuit for driving the gate of the P-channel driver transistor with sufficient driving and sinking current, while avoiding reverse currents through predriver stage transistors during tristate overvoltage conditions.
SUMMARY OF THE INVENTION
These and other objects of the present invention are provided for by a CMOS tristate output buffer having an N-well bias circuit with an input hysteresis characteristic. The tristate output buffer has a drive mode, during which the tristate output buffer drives a voltage at an output terminal, and a tristate mode, during which the tristate output buffer represents a high input impedance at the output terminal. The N-well bias circuit biases an N-well of the tristate output buffer such that the voltage at the output pad is applied to the N-well at appropriate times during the tristate mode. The input hysteresis characteristic of the N-well bias circuit reduces unnecessary overswitching in the N-well bias circuit, providing stability against variations of the output terminal voltage near a power supply voltage of the tristate output buffer during tristate mode.
A tristate output buffer according to the present invention has a first power supply node for coupling to a first power supply voltage and a reference node for coupling to a reference voltage. The tristate output buffer drives the output terminal between the first power supply voltage and the reference voltage in the drive mode. The tristate output buffer comprises a P-channel driver transistor coupled between the first power supply node and the output terminal, the P-channel driver transistor being in the N-well. The N-well bias circuit is coupled to the N-well, to the first power supply node, and to the output terminal. The N-well bias circuit provides an N-well bias voltage to the N-well responsive to the voltage at the output terminal relative to the first power supply voltage during tristate mode. The N-well bias circuit has an input hysteresis characteristic for providing N-well bias circuit stability. In one form, the N-well bias circuit includes a hysteresis latch.
In another form, the tristate output buffer comprises a gate bias circuit for biasing the gate of the P-channel driver transistor, the gate bias circuit biasing the gate of the P-channel driver transistor responsive to the voltage at the output terminal relative to the first power supply voltage during tristate mode. The gate bias circuit has an input hysteresis characteristic for providing gate bias circuit stability. In another form, the gate bias circuit includes a hysteresis latch.
In yet another form, the tristate output buffer includes an N-well bias circuit including a high-gain, high-speed multiplexing switch for multiplexing the N-well bias voltage between the output terminal and the first power supply voltage responsive to their relative values during tristate mode. The N-well bias circuit has adequate input hysteresis sufficient to increase circuit stability against output terminal voltage transients occurring near VDD during tristate mode.
In yet another form, a tristate output buffer according to the present invention comprises an N-well bias circuit comprising a comparator for biasing the N-well to the greater of the output terminal voltage and the supply voltage. The tristate output buffer further comprises a gate bias transistor coupled between the N-well and the gate of the P-channel driver transistor for coupling the N-well to the gate of the P-channel driver transistor during tristate mode. The tristate output buffer further comprises a predriver stage, comprising a predriver pullup transistor and a predriver pulldown transistor, for driving the gate of the P-channel driver transistor. A P-channel switch transistor is interposed between the predriver pullup transistor and the gate of the P-channel driver transistor for avoiding reverse currents through the predriver pullup transistor when the voltage at the gate of the P-channel driver transistor rises above the first power supply voltage. A resistive element is interposed between the gate of the P-channel driver transistor and the predriver pulldown transistor. The P-channel switch transistor is driven by a signal generated by an active-mode circuit for quickly turning off the P-channel switch transistor when the output voltage exceeds the first power supply voltage during tristate mode.
In yet another form, the tristate output buffer comprises an N-well bias circuit for biasing the N-well to the greater of the output terminal voltage and the supply voltage during tristate mode, and for biasing the N-well to the first power supply voltage during drive mode. The tristate output buffer further comprises a gate bias transistor coupled between the N-well and the gate of the P-channel driver transistor, a predriver stage comprising a predriver pullup transistor and a predriver pulldown transistor, a P-channel switch transistor interposed between the predriver pullup transistor and the gate of the P-channel driver transistor, a resistive element interposed between the gate of the P-channel driver transistor and the predriver pulldown transistor, and an active-mode circuit for quickly turning off the P-channel switch transistor when the output voltage exceeds the first power supply voltage during tristate mode.
BRIEF DESCRIPTION OF THE DRAWINGS
The above mentioned objects and other objects, features, and advantages of the invention may be better understood by referring to the following detailed description, which should be read in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a CMOS tristate output buffer according to the prior art;
FIGS. 2 and 2A illustrate a block diagram of a CMOS tristate output buffer according to the prior art containing modifications to tolerate tristate mode overvoltages;
FIGS. 3A and 3B illustrate a stabilized, overvoltage tolerant CMOS tristate output buffer according to a first embodiment of the present invention;
FIG. 4 illustrates a stabilized, overvoltage tolerant CMOS tristate output buffer according to a second embodiment of the present invention; FIGS. 5A and 5B illustrate a stabilized, overvoltage tolerant CMOS tristate output buffer according to a third embodiment of the present invention.
FIG. 6 illustrates an overvoltage tolerant CMOS tristate output buffer according to a fourth embodiment of the present invention.
FIG. 7 illustrates an overvoltage tolerant CMOS tristate output buffer according to a fifth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 3A and 3B illustrate a stabilized, overvoltage tolerant CMOS tristate output buffer 300 according to a first embodiment of the present invention. Output buffer 300 comprises a P-channel driver transistor P1 having a source coupled to a node VDD, a drain coupled to a node VPAD, and a gate coupled to a node VP. Driver transistor P1 is formed in an N-well, which is generally referred to herein as a node NSUB, and has a backgate coupled to or integral with the N-well. Output buffer 300 further comprises an N-channel pulldown transistor N1 coupled between node VPAD and ground, with a gate coupled to a node VN.
Output buffer 300 further comprises a node OEB and a node DB for receiving input signals from low voltage CMOS core logic circuitry (not shown). The input signal received at node OEB is a complement of an output enable signal, while the input signal received at node DB is the complement of a data signal. Generally, as is known to one of ordinary skill in the art, the output enable signal, the data signal, and their complements may be considered to be available as inputs to the output buffer 300, whether or not these input nodes are actually shown in the drawings. For purposes of simplicity and clarity of disclosure, the terms OE, OEB, D, and DB will refer to the nodes themselves and/or their signal values interchangeably. In the present embodiment disclosed, the signal OEB is inverted by an inverter NOT1 to generate the signal OE.
Output buffer 300 further comprises a NOR gate NOR1 for receiving the signals at nodes OEB and DB and producing the Boolean NOR of these two logic signals. Output buffer 300 further comprises a P-channel predriver pullup transistor P2, a P-channel switch transistor P3, and an N-channel predriver pulldown transistor N2. Transistor P2 comprises a source coupled to VDD, a gate coupled to an output of NOR gate NOR1, and a drain. Transistor N2 comprises a drain coupled to the gate of driver transistor P1 at node VP, a source coupled to ground, and a gate coupled to the output of NOR gate NOR1. Switch transistor P3 is coupled between the drain of transistor P2 and the node VP. As will be described more fully later, transistor P3 is turned on during drive mode. Thus, the transistors P2 and N2 form a predriver stage for providing the appropriate driving voltage, together with sufficient driving current, to the gate of driver transistor P1 during drive mode.
Output buffer 300 further comprises an AND gate AND1 for receiving the signal OE, as generated by inverter NOT1, and the signal DB. AND gate AND1 has an output node coupled to the input of an inverter NOT2, which in turn has an output coupled to node VN. N-channel transistors N3 and N7, coupled as shown in FIG. 3A, are optional components for enhancing the grounding of node VN and the gate of transistor N2 when the voltage at node Y is driven high.
The combinational logic described above results in the following truth table:
TABLE 1______________________________________OE D VP VN VPAD______________________________________low low high low HIGH IMPEDANCElow high high low HIGH IMPEDANCEhigh high low low highhigh low high high low______________________________________
When OE is high, the output buffer 300 is in the drive mode. Thus, when OF is high and D is high, node VN is driven low to turn off pulldown transistor N1, while node VP is driven low to turn on driver transistor P1, causing VPAD to be driven high. When OE is high and D is low, the node VP is driven high to turn off driver transistor P1, while node VN is driven high to turn on pulldown transistor N1, thus causing VPAD to be driven to ground.
However, when OE is low, the output buffer 300 is in tristate mode, and the value of D does not matter. In this case, node VP is driven high to turn off driver transistor P1, and node VN is driven low to turn off pulldown transistor N1. Therefore, the node VPAD is isolated and the output buffer 300 represents a high impedance looking inward from the VPAD terminal.
The output buffer 300 further comprises a sensing and protection circuit 310, as shown in FIGS. 3A and 3B, to ensure that NSUB is driven to the voltage at node VPAD at the appropriate times to avoid reverse currents and latch-up in driver transistor P1. Sensing and protection circuit 310 comprises a sensing circuit 312, a clamping transistor N4, switch transistors P7 and P8, a clamping transistor P9, and a transistor P10.
Sensing circuit 312 comprises a P-channel transistor P5 coupled between node VPAD and a node Y having a gate coupled to node VDD. Sensing circuit 312 further comprises a P-channel transistor P6 coupled between VDD and a node X having a gate coupled to node VPAD. Sensing circuit 312 further comprises an N-channel transistor N5 coupled between node Y and ground having a gate coupled to node X. Finally, sensing circuit 312 comprises an N-channel transistor N6 coupled between node X and ground having a gate node coupled to node Y. Sensing circuit 312 is coupled at node Y to clamping transistor N4, and at node X to clamping transistor P9. Clamping transistor N4 is coupled between node Y and ground, and has a gate coupled to node OE. Clamping transistor P9 is coupled between node X and VDD, and has a gate coupled to node OEB. Sensing circuit 312 is also coupled at node Y to the gate of switch transistor P7, and coupled at node X to the gate of switch transistor P8.
Switch transistor P7 is coupled between the node VDD and the node NSUB. When switch transistor P7 is on, NSUB is thus effectively coupled to node VDD. Switch transistor P8 is coupled between the node VPAD and the node NSUB. When switch transistor P8 is on, NSUB is thus effectively coupled to node VPAD. Together, switch transistors P7 and P8 form a means for multiplexing the voltages at VDD and VPAD onto the node NSUB.
Sensing and protection circuit 310 further comprises P-channel transistor P10 coupled between node VDD and node X having a gate driven by node Y. The backgate of transistor P10 is connected to VDD.
Throughout the drive mode, when OE is high, nodes Y and X are clamped at ground and at VDD, respectively. More specifically, because OE is high, clamping transistor N4 clamps node Y to ground. Further, because OEB is low, clamping transistor P9 clamps node X to VDD. This turns transistor N6 off, and transistor N5 on. In turn, switch transistor P7 is turned on and switch transistor P8 is turned off, thus connecting node NSUB to VDD. This provides a sufficient biasing voltage to the N-well of driver transistor P1. Generally, voltages in the tristate output buffer 300 do not reach a value greater than VDD during drive mode.
As shown in FIG. 3A, tristate output buffer 300 further comprises a gate bias transistor P4 coupled between node NSUB and node VP having a gate coupled to node X. During drive mode, when node X is at VDD, gate bias transistor P4 is turned off and does not affect the voltage at node VP, which is being driven by predriver circuit P2 and N2 as described previously.
Also as shown in FIG. 3A, switch transistor P3 is driven at its gate by the signal at node Y. During drive mode, when node Y is low, switch transistor P3 is turned on and operates as a short between the drain of transistor P2 and node VP. Thus, during drive mode the transistors P2 and N2 form a predriver inverter for driving the gate of driver transistor P1.
During tristate mode, when OE is low, sensing and protection circuit 310 operates as follows. Clamping transistor N4 is turned off, and has minimal effect on the voltage at node Y. Further, clamping transistor P9 is turned off, and has minimal effect on the voltage at node X. Sensing circuit 312 is then driven by inputs VPAD and VDD at the sources of transistors P5 and P6, respectively. Two operating points can be easily understood: (1) when VPAD is significantly lower than VDD, and (2) when VPAD is significantly higher than VDD. In the first case, transistor P5 is turned off and transistor P6 is turned on. Transistor N5 is thus turned on and transistor N6 is turned off. Therefore, when VPAD is significantly lower than VDD, node Y is low and node X is at VDD, causing NSUB to be coupled to VDD through switch transistor P7.
In the second case, when VPAD is significantly higher than VDD, transistor P5 is turned on and transistor P6 is turned off. Transistor N5 is thus turned off and transistor N6 is turned on. Therefore, when VPAD is significantly lower than VDD, node Y is high (near VPAD) and node X is low, causing NSUB to be coupled to VPAD through switch transistor P8. This is the desired result, because where the voltage at node NSUB is substantially equal to the voltage at node VPAD, the diode formed between the drain of driver transistor P1 and the N-well is prevented from being forward biased.
Further to the second case when VPAD is significantly higher than VDD, gate bias transistor P4 is turned on because node X is low. This causes the gate of driver transistor P1 to be driven to the voltage at node NSUB, i.e., to substantially near VPAD, thus preventing reverse leakage current through driver transistor P1. This reduces gate oxide stresses as well. Also, because node Y is high, switch transistor P3 is turned off. This advantageously prevents undesired reverse leakage current from node VP to node VDD through transistor P2.
For situations not falling within (1) or (2) above, i.e., when VPAD is hovering at or near VDD during tristate mode, the unique configuration of the sensing circuit 312 and transistor P10 causes the signals at nodes X and Y to depend on the past value of VPAD as well as its present value, thus providing an input hysteresis characteristic to the sensing and protection circuit 310. This prevents circuit instability and overswitching of the switch transistors P7 and P8. The prevention of unnecessary switching of transistors P7 and P8 reduces heating, high-frequency noise, and other detrimental effects of over-switching.
Referring to FIGS. 3A and 3B, when VPAD rises progressively from 0.0 volts to 5.0 volts during tristate mode, node NSUB will be switched over from VDD to VPAD when VPAD is an upper switchover voltage equal to VDD plus an upper threshold voltage. Conversely, if VPAD then lowers progressively from 5.0 volts to 0.0 volts, node NSUB will be switched back over from VPAD to VDD when VPAD is at a lower switchover voltage equal to VDD minus a lower threshold voltage. In a typical embodiment of the invention, where VDD is equal to 3.3 volts, the upper and lower threshold voltages are each approximately 0.9 volts, causing the upper switchover voltage to be 4.2 volts and the lower switchover voltage to be 2.4 volts. Using design modifications which would be understood by one of ordinary skill in the art upon reading this disclosure, the parameters of various circuit transistors can be varied to achieve different upper and lower switchover voltages. For example, in another typical embodiment with VDD equal to 2.7 volts, the upper and lower switchover voltages are 3.8 volts and 2.3 volts, respectively.
Advantageously, the operation of sensing circuit 312, which in combination with transistor P10 may be called a "hysteresis latch," enhances circuit stability by causing the states of switch transistors P7 and P8 to remain steadfast when the voltage VPAD hovers in a range between the lower and upper switchover voltages during tristate mode. The state of the switch transistors P7 and P8 depends on the past value of VPAD before entering the range between the lower and upper switchover voltages: if VPAD came from above the upper switchover voltage into this range, switch transistor P7 remains off and switch transistor P8 remains on; if VPAD came from below the lower switchover voltage into this range, switch transistor P7 remains on and switch transistor P8 remains off.
Advantageously, it is noted that any transitions of the switch transistors P7 and P8 are "hard transitions," provided by "hard transitions" of X and Y from the "hysteresis latch," resulting in less transition current and heating in these comparatively large transistors. Overall, the effect is improved circuit stability.
In the embodiment shown in FIGS. 3A and 3B, the P-channel transistors P1-P10 are formed in a common N-well, denoted as node NSUB. Transistors P1, P3, P4, P6, P7, and P8 have backgate nodes connected to the N-well. Transistors P2, P5, P9, and P10 have backgate nodes coupled to node VDD.
FIG. 4 illustrates a stabilized, overvoltage tolerant CMOS tristate output buffer 400 according to a second embodiment of the present invention. Output buffer 400 comprises elements including a sensing and protection circuit 410 which are similar to the elements of output buffer 300 of FIGS. 3A and 3B with certain modifications. Specifically, as shown in FIG. 4, the gate of gate bias transistor P4 is coupled directly to the node OE. This causes the node NSUB to be coupled to the gate of driver transistor P1 at node VP at all times during tristate mode, when OE is low. This direct coupling provides a timing advantage over the circuit of FIGS. 3A and 3B, causing node VP to follow NSUB without waiting for gate bias transistor P4 to turn on during tristate mode as VPAD rises above the upper switchover voltage. The direct coupling of node VP to node NSUB during tristate mode is enabled by the fact that node NSUB never goes low, and thus driver transistor P1 will always remain turned off during tristate mode.
Tristate buffer 400 according to the second embodiment of the present invention also differs from FIGS. 3A and 3B in that elements N3 and N7 are not included. Additionally, the backgate of switch transistor P3 is coupled to node VP instead of node NSUB, and the backgate of transistor P5 is coupled to node NSUB instead of node VPAD. Further, a node OEIN for providing an output enable signal input to an inverter NOT3 is included. The output of inverter NOT3 provides the OEB signal discussed previously with respect to the previous embodiment. Finally, a resistive element R1 is included between node VP and the drain of transistor N2. The resistive element R1 may comprise appropriately doped polysilicon. The value of resistance R1 is generally low, but can be varied using methods known in the art in order to adjust the timing of current being sunk through transistor N2. An exemplary value for R1 may be, for example, between 100 and 500 ohms.
FIGS. 5A and 5B illustrate a stabilized, overvoltage tolerant CMOS tristate output buffer 500 according to a third embodiment of the present invention. Output buffer 500 comprises elements including a sensing and protection circuit 510 which are similar to the elements of output buffer 300 of FIGS. 3A and 3B with certain modifications. One modification is that the backgate of transistor P6 is coupled to node VDD instead of node NSUB as in FIG. 3A.
More importantly, however, sensing and protection circuit 510 includes a sensing circuit 512 coupled to switch transistors P7 and P8 by means of an amplifying circuit 513. Sensing circuit 512 comprises transistors P5, P6, N5, and N6 coupled to nodes VPAD and VDD and providing outputs at latch output nodes S and T. Nodes S and T are provided as inputs to amplifying circuit 513, which comprises output nodes Q and R for coupling to switch transistors P7 and P8, respectively.
Amplifying circuit 513 comprises a transistor P11 having a gate coupled to node T, a source coupled to node NSUB, and a drain coupled to node Q. Amplifying circuit 513 further comprises a transistor N11 having a gate coupled to node T, a source coupled to ground, and a drain coupled to node Q. Amplifying circuit 513 further comprises a transistor P12 having a gate coupled to node S, a source coupled to node NSUB, and a drain coupled to node R. Finally, amplifying circuit 513 comprises a transistor N12 having a gate coupled to node T, a source coupled to ground, and a drain coupled to node R. Switching transistors P7 and P8 can be relatively large and can require greater current to drive their gates relative to other P-channel transistors in the output buffer 500 (excepting, of course, driver transistor P1). Amplifying circuit 513 enhances the operation of sensing and protection circuit 510 by providing greater driving current to drive the gates of switch transistors P7 and P8 responsive to the outputs of sensing circuit 512.
As shown in FIG. 5A, the node Q is also coupled to the gate of switch transistor P3, while the node R is also coupled to the gate of gate bias transistor P4. During non-tristate mode, when OE is high and therefore node S is low, node T is high, node Q is low, and node R is high, switch transistor P3 will be turned on to allow transistors P2 and N2 to operate as a predriver circuit for driver transistor P1. Additionally, gate bias transistor P4 will be turned off and will not affect the voltage at node VP. This analysis also applies during tristate mode when node S is low and node T is high.
However, when the sensing circuit 512 drives node S high and node T low during tristate, node Q will be driven high and node R will be driven low. This causes the node NSUB to be connected to node VPAD through transistor P8. This also causes the gate bias transistor P4 to turn on responsive to the low state of node R, thus driving the voltage at node VP to the voltage at node NSUB to reduce reverse leakage current through P-channel driver transistor P1 and to reduce gate oxide stresses. Advantageously, switch transistor P3 is turned off by the high state of node Q, thus preventing leakage current from flowing from node VP to node VDD through transistor P2.
FIG. 6 illustrates an overvoltage tolerant CMOS tristate output buffer 600 according to a fourth embodiment of the present invention. Output buffer 600 of FIG. 6 is similar to the output buffer 400 of FIG. 4 except that a sensing and protection circuit 610 is provided which has a different structure than sensing and protection circuit 410 of FIG. 4. In particular, sensing and protection circuit 600 comprises transistors P7 and P8 which are not coupled in a multiplexing fashion, but rather the gate of transistor P8 is tied to VDD while the gate of transistor P7 is coupled to an output Y of an active-mode circuit 614.
Active-mode circuit 614 comprises a P-channel passgate transistor P14, an N-channel biasing transistor N13, and a P-channel biasing transistor P13. Biasing transistor N13 is connected between node VPAD and the gate of passgate transistor P14 and is driven at its gate by the signal OEB. Biasing transistor P13 is connected between node VDD and the gate of passgate transistor P14 and is also driven at its gate by the signal OEB. Passgate transistor P14 is coupled between node VPAD and node Y, and is driven at its gate by the output of biasing transistors N13 and P13. Active-mode circuit 614 further comprises an N-channel transistor coupled between node Y and ground and being driven by the signal OE. The signal Y is used to drive the gate of switch transistor P3, while the signal OE is used to drive the gate of gate bias transistor P4.
When output buffer 600 is in drive mode, OE is high and node Y is low. Accordingly, the sensing and protection circuit 610 allows gate bias transistor P4 to be off and transistor P3 to be on at all times during drive mode. This allows the gate VP of P-channel driver transistor P1 to be driven as dictated by the value of DB.
When output buffer 600 is in tristate mode, OE is low and node OEB is substantially equal to VDD. Without limiting the scope of the present invention and for clarity of disclosure, the exemplary case of VDD=3.3 volts will be described. Because node OEB is substantially equal to VDD=3.3 volts, the voltage at the gate of passgate transistor P14 is limited to VDD minus the threshold voltage of biasing transistor N1, or approximately 2.6 volts. When a voltage applied to VPAD exceeds 2.6 volts plus the threshold voltage of passgate transistor P14, or approximately 3.3 volts, the passgate transistor P14 is turned on to couple VPAD to the node Y. When the node Y is thus driven high, the transistor P7 is turned off and the transistor P3 is turned off. Concurrently, because transistor P8 has its gate coupled to VDD=3.3 volts, transistor P8 will be assisting in providing the value of VPAD>=3.3 volts to the node NSUB. Finally, because the gate bias transistor P4 is always on during tristate mode, the node VP is driven to the greater of VPAD or VDD as required.
Advantageously, the active mode circuit 614 of FIG. 6 provides a fast means for switching the switch transistor P3 responsive to the relative values of VPAD and VDD. In this manner, as VPAD rises above VDD during tristate mode, switch transistor P3 turns off in time to prevent reverse current from node VP to VDD through transistor P2.
It is to be noted that the value of resistance R1 is generally low, but can be varied using methods known in the art in order to adjust the timing of current being sunk through transistor N2. The timing of current being sunk through transistor N2 needs to be fast enough to turn P-channel driver transistor P1 on quickly, but without causing a current spike through transistor P1, which may cause unwanted inductive noise on the system bus to which the tristate output buffer 600 is connected. An exemplary value for R1 may be, for example, between 100 and 500 ohms.
FIG. 7 illustrates an overvoltage tolerant CMOS tristate output buffer 700 according to a fifth embodiment of the present invention. Output buffer 700 of FIG. 7 is similar to the output buffer 600 of FIG. 6 except that a sensing and protection circuit 710 is provided which is a modified form of sensing and protection circuit 610. Sensing and protection circuit comprises an active mode circuit 714 similar in structure and operation to active mode circuit 614 and an N-channel transistor N4 similar in structure and operation to N-channel transistor N4 of FIG. 6. However, sensing and protection circuit 710 comprises a transistor P7 having its gate coupled directly to VPAD instead of to node Y. Thus, coupled as shown in FIG. 7, transistors P7 and P8 form a comparator circuit having the nodes VDD and VPAD as inputs and having the node NSUB as the output.
In operation, the output buffer 700 generates the signal at node Y in a manner similar to that of the output buffer 600 of FIG. 6. In particular, as VPAD rises above VDD during tristate mode, the active mode circuit 714 drives node Y high quickly enough to avoid reverse current from node VP to VDD through transistor P2.
Advantageously, however, the sensing and protection circuit 710 drives the voltage at node NSUB to the greater of VPAD or VDD at all times, and not only during tristate mode. This is because transistors P7 and P8, which are in a comparator arrangement, drive node NSUB in a manner which depends only on the values of VDD and VPAD, and not other system voltages such as the voltages at nodes OE or OEB. Such a characteristic may prove advantageous in preventing excessive oxide stress during an unforeseen occurrence such as a bus contention, when an external device may be attempting to drive VPAD to 5.0 volts even though the output buffer 700 is in drive mode. In this circumstance, the voltage at node NSUB will rise to the 5.0 volt level and excessive oxide stresses will be reduced.
It is apparent that many modifications and variations of the present invention as set forth here may be made without departing from the spirit and scope thereof. The specific embodiments described here and above are given by way of example only and the invention is limited only by the terms of the appended claims.
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An overvoltage tolerant CMOS tristate output buffer capable of withstanding tristate overvoltages without reverse currents or latch-up, the output buffer having a stabilized protection circuit for driving the N-well and gate of the P-channel driver transistor to the output pad voltage when the output pad voltage becomes excessive. The stabilized protection circuit includes a hysteresis circuit for controlling switch transistors which bias the N-well. The presence of the hysteresis circuit causes the protection circuit to have an input hysteresis characteristic, thus preventing excessive switching of the N-well biasing transistors when the output pad voltage varies near the output buffer power supply voltage during tristate.
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FIELD OF THE INVENTION
[0001] The present invention relates to a rigid food container system configuration for foodstuff that preserves and facilitates the displaying of contents. More particularly, the invention relates to a food packaging containment system where a first food container and a second food container are held together by snap-fit.
BACKGROUND OF THE INVENTION
[0002] Restaurants and food markets have utilized rigid containers to protect and display both perishable and fragile food items such as sandwiches, salads and bakery items. Rigid plastic food containers are typically manufactured from Polystyrene, Polypropylene, Polyethylene Terephthalate (PET), Polylactide, Polyvinyl Chloride (PVC), or other rigid polymers. They generally comprise either of two-partsโa tray and lidโor they may be a one-piece construction with a hinge that modifies one portion of the container to act as the tray and the other connected portion to act as a lid. Furthermore, they are available in a variety of shapes and cross-sectionsโcircular, rectangular, square, and elliptical, etc.
[0003] These traditional roles of plastic packaging are now the minimum expected standards, and the requirements placed on plastic food packaging continue to expand as increasing demands are placed upon it. Presentation, brand presence, consumer desires, added value to enhance commercial competitiveness, differentiation, imagery and psychology have resulted in the design and application of plastic packaging becoming more challenging. Convenience and versatility continue to shape the future of packaging, with consumers gravitating toward packaged convenience items that minimize the impact on their behavior. This has forced packaging manufacturers to include social and environmental considerations into their development process. The growth of fast food restaurants and the competitive response from food markets offering packaged meal product for consumers โon-the-goโ is such an indication of this trend. However, there is a growing body of evidence that consuming fast food product while driving presents enormous hazards. Despite regulation that requires at least one hand on the wheel at all times, much of currently available food product and its packaging is not designed with this regulation in mind. It is difficult, if not impossible, for example, for one to safely consume a food product that may need a condiment or other taste-enhancing feature. Additionally, this form of food consuming has gained more attention since the banning in some areas of handheld cell phonesโrepresenting a belief that mufti-tasking when driving is hazardous.
[0004] Despite these concerns, this trend is unlikely to stop as consumers lifestyles evolve. The fast food industry is growing and the automotive industry continues to provide in-vehicle accessories and interiors to promote eating and drinking. All this presents opportunities to packaging manufacturers and their food processing clients to develop packaging integrated food solutions especially for convenience-oriented consumers while in transport.
[0005] There is a need to offer a variety of convenience-enhancing multiple compartmentalized food trays that take into account driver ergonomics, including the encumbrance consuming food while driving places on the driver and passengers, and existing accessories that currently exist in vehicles. This invention provides for a unique approach that achieves this objective.
SUMMARY OF THE INVENTION
[0006] In a preferred embodiment of the invention, the food container system comprises a first tray member and at least one smaller tray member, wherein the smaller tray member is formed with a shaped channel into its underside so that the rim of the first tray may be inserted into the shaped channel. The first tray member acts as the primary supporting means for the smaller second tray member so that a complementary combination of food items may be associated more effectively and will further be efficiently handed from one person to another. For example, the first tray member may contain corn chips or vegetables and a smaller second tray may contain a complementary condiment thereby providing enhanced utility to consumers. Ideally, the weight distribution between the first and the at least one smaller tray member is such that when they are integrated together by inserting the rim of the first tray member into the shaped channel of the smaller second tray member, the integrated food container system is able to stand alone and be held up by the base first tray.
[0007] In another embodiment of the invention, the food container system comprises a first tray member and a lid member, that when in its typical market display mode, the food container system stands upright with the base of the first tray member supported on, say, a shelf and the mouth of the lid member is attached to the mouth of the tray member in order to protect its contents using a detachable interlocking arrangement. The detachable interlocking arrangement may be a releaseably lockable snap-fit lock mechanism that ensures that the lid member and the tray member are held firmly together as the food container system is transported. Further, the lid member is formed firstly with a raised roof such that when the said lid member is inverted, it acts as a second smaller tray that can be used to hold additional foodstuff, and secondly with a shaped channel into which the rim of the first tray may be inserted. As in with the prior embodiment, the weight distribution between the first and second tray members are such that the integrated food container system is held up by the base tray when placed on a supporting surface, such as a table. Alternatively, the first tray member may be formed so that it can be held by the consumer with one hand, thereby leaving the consumer's other hand to access the food items in both tray members.
[0008] This invention is a novel plastic packaging solution that improves significantly on the convenience and therefore marketability of food product.
[0009] 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 are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0011] FIG. 1 is an isometric view of an embodiment of the present invention showing the disassembled smaller second tray member and first tray member.
[0012] FIG. 2 is a cross-sectional view of the assembled container system in FIG. 1 .
[0013] FIG. 3 is an isometric view of the container system in FIG. 1 but with the smaller second tray member inverted.
[0014] FIG. 4 is an isometric view of the container system in FIG. 3 assembled ready for use by the consumer.
[0015] FIG. 4A is a cross-sectional view of the assembled container system in FIG. 4 .
[0016] FIG. 4B is an exploded fragmentary sectional view of area P-P of the container system in FIG. 4A .
[0017] FIG. 5 is an isometric view of another embodiment of the present invention showing the disassembled smaller second tray member and first tray member.
[0018] FIG. 6 is an isometric view of the container system in FIG. 5 but with the smaller second tray member inverted.
[0019] FIG. 7 is an isometric view of the container system in FIG. 6 assembled and ready for use by the consumer.
[0020] FIG. 8 is an elevation side view of another embodiment of the present invention.
[0021] FIG. 9 is an isometric view of the container system in FIG. 8 showing the smaller second tray member assembled to the first tray member.
[0022] FIG. 10 is an isometric view of the smaller second tray member of the container system in FIG. 8 .
[0023] FIG. 11 is a fragmentary sectional view of the container system in FIG. 8 taken along the line N-N in FIG. 9 .
[0024] FIG. 12 is an elevation side view of another embodiment of the present invention.
[0025] FIG. 13 is an isometric view of the container system in FIG. 12 showing the smaller second tray member inverted and assembled to the first tray member.
[0026] FIG. 14 is an isometric view of the smaller second tray member of the container system in FIG. 12 .
[0027] FIG. 15 is a fragmentary sectional view of the container system in FIG. 13 taken along the line 0 - 0 .
[0028] FIG. 16 is an isometric view of another embodiment of the present invention.
[0029] FIG. 17 is an isometric view of the container system in FIG. 16 showing the smaller second tray member inverted and assembled to the first tray member.
[0030] FIG. 18 is an elevation view of the container system in FIG. 17 .
[0031] FIG. 19 is a fragmentary sectional view of the container system in FIG. 18 taken along the line P-P.
[0032] FIG. 20 is an elevation side view of one container system of the container systems in FIG. 16 stacked upon another identical container system.
[0033] FIG. 21 is an isometric view of another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are described. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, the embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.
[0035] Referring to the drawings and in particular to FIG. 1 , there is shown a rigid polymer construct food container system 1 according to the present invention. The food container system 1 comprises a first tray member 4 and a second smaller tray member 2 . The second smaller tray member 2 is designed to also act as a lid member when it is inverted as shown. To achieve an assembled, โready-for-saleโ condition, the smaller second tray member rim 8 of the food container system 1 is configured so that it mates with the first tray member rim 16 . Such attachment is achieved by the use of an annular snap-fit lock mechanism wherein the smaller second tray member rim 8 is releaseably lockable to the first tray member rim 16 . The second smaller tray member 2 comprises a planar surface 3 that is lower relative to the smaller second tray member rim 8 but above the floor footing 5 thereby forming a cavity 23 in the second smaller tray member 2 , and a curvilinear shaped channel 14 that is further configured to be similar to that of the first tray member rim 16 . The shaped channel 14 is further defined by inner sidewall 10 and an opposing outer sidewall 12 between which the first tray member rim 16 is inserted. This feature is exemplified in more detail in FIGS. 3 & 4 . Turning first, however, to FIG. 2 , therein is shown a cross-sectional view of the assembled, โready-for-saleโ container system in FIG. 1 . The snap-fit lock mechanism that is used to releaseably lock the smaller second tray member 2 to the first tray member 4 is further exemplified here. Snap-fit locks have in common the principle that a protruding part of one component, e.g., a hook, stud or bead, is deflected briefly during the joining operation and is lodged in a complementary configured depression in the complementary mating component. In this instance, the snap-fit lock mechanism, as shown, is of an annular ring type wherein a continuous circumferential female groove 9 is formed immediately adjacent to the second smaller tray member rim 8 and which that mates with a complementary continuous circumferential male rib 11 formed at the first tray member rim 16 . When the smaller second tray member 2 and the first tray member 4 are assembled in this manner with foodstuff within it, the container system 1 is in a โready-for-saleโ condition. It will be appreciated that the annular ring snap-fit approach provides resistance to leakage that would not be offered by discrete or non-annular (e.g. hook, stud) type snap-fit lock mechanisms. The planar surface 3 of the second smaller tray member 2 is elevated above the second smaller tray member rim 8 by distance H. The distance h between the floor 18 of the shaped channel 14 and the plane of the first tray member rim 16 is preferably not greater than the distance H.
[0036] Turning now to FIG. 3 , therein is shown the embodiment in FIG. 1 but with the second smaller tray member 2 inverted. The second smaller tray member 2 is shown inverted to display tray recess 19 into which other foodstuff may be placed. For illustrative purposes, shown is a polymer film or foil 25 that may be used to optionally retain the foodstuff within its respective tray recess 7 of first tray member 4 . In a similar manner, the foodstuff in the second smaller tray member 2 may optionally be retained within its tray recess 19 with a foil (not shown). Turning to FIG. 4 , therein is shown the container system in FIG. 3 with the inverted second smaller tray member 2 attached to the first tray member 4 to form an integrated food container system 21 . Attachment of the inverted second smaller tray member 2 to the first tray member 4 is achieved by inserting any segment of the first tray member rim 16 into the shaped channel 14 of the inverted second smaller tray member 2 and causing an interference fit between the inner and outer sidewalls 10 , 12 of the second smaller tray member 2 and the first tray member rim 16 . FIG. 4A shows an elevation side view of the assembled container system in FIG. 4 . Turning now to FIG. 4B , therein is shown an enlarged cross-sectional view of the area P-P in FIG. 4A showing the interlocking arrangement between the first tray member rim 16 of the first tray member 4 and the inverted second smaller tray member 2 . The inner sidewall 10 and outer sidewall 12 are formed at an angle toward each other so that, together, they enable an interference fit with the first tray member 4 at the tray inner wall 13 and at the first tray member rim 16 . Further, as shown, when inserted fully, the shaped channel floor 18 preferably sits on the first tray member rim 16 so that the planes of the mouths of the second tray member 2 and the first tray member 4 approximately coincide. The consumer has then a number of options including placing the base of first tray member 4 into, say, an automobile center consol cup-holder or holding the first tray member 4 with one hand while using their free hand to access the foodstuff in both the first and second tray recesses. For example, sliced carrots may be placed into the first tray member recess 7 and a salad dressing placed into the smaller second tray member recess 19 .
[0037] Turning now to FIGS. 5 , 6 and 7 , therein are shown renditions of another embodiment of the present invention. In these renditions, when the second smaller tray member 2 is inverted, the curvilinear configuration of the shaped channel 14 is such that it will mate with the first tray member rim 16 only at the complementary curvilinear extended tray rim segment 28 of the first tray member rim 16 as only here is the radius of the shaped channel 14 similar to that of the curvilinear extended tray rim segment 28 . Additionally, the shaped channel inner sidewalls 10 , 26 & 20 and opposing outer sidewalls 12 , 24 & 22 are formed at an angle toward each other so that, together, they make a mechanical attachment with the first tray member rim 16 when said curvilinear extended tray rim segment 28 is inserted into the shaped channel 14 in a similar manner as exemplified in FIG. 4B . In this embodiment, the cross-sectional area of the mouth of the tray member defined by the first tray member rim 16 is less restricted as compared with the embodiment of the invention depicted in FIG. 1 .
[0038] Turning to FIGS. 8 & 9 , therein are illustrations of a preferred embodiment of the invention wherein the smaller second tray member 2 and first tray member 4 are secured to each other using screw thread connections to achieve a โready-for-saleโ condition.
[0039] FIG. 9 shows the second smaller tray member 2 inverted and attached to the first tray member 4 to form an integrated food container system 21 , and as illustrated, the male helical thread 40 in the second smaller tray member 2 is formed on the tapered surface 41 , and designed to engage a similarly configured but complementary helical female thread 38 formed on the inner wall 13 . When engaged in this manner, the faying surfaces 34 , 36 of the tray members 2 , 4 respectively, in concert with the threaded connections, makes leak-resistant the container system. Turning to FIG. 10 , therein is illustrated an isometric view of the second smaller tray member 2 of the embodiment in FIGS. 8 & 9 . As shown, a discrete male rib thread 42 is formed on the outer sidewall 12 , and that is used to secure the inverted second smaller tray member 2 to the first tray member rim 16 . The manner of engagement of the inverted second smaller tray member 2 is further exemplified in FIG. 11 which is a cross-sectional view of the container system 1 in FIG. 10 taken along the line N-N. Attaching the inverted second smaller tray member 2 to the first tray member 4 is achieved by placing the first tray member rim 16 into the shaped channel 14 and then sliding said shaped channel 14 along the tray rim so that the discrete male rib thread 42 slides along the female groove thread 38 of the first tray member 4 ; and the opposing resistance caused by the force between the inner sidewall 10 and the first tray member rim 16 results in an interference fit that firmly holds the inverted second smaller tray member 2 and first tray member 4 together.
[0040] Turning now to FIGS. 12 , 13 , 14 & 15 , therein is shown renditions of another embodiment of the invention. This embodiment possesses all the features of the embodiment depicted in FIGS. 8 , 9 , 10 & 11 , except that securing the inverted second smaller tray member 2 to the first member 4 is further facilitated by a discrete male protuberance 44 . Commonly referred to as a stud snap-fit lock, securing the inverted second smaller tray member 2 to the tray is achieved by sliding the shaped channel 14 along the first tray member rim 16 as previously described and exemplified in FIGS. 8 , 9 , 10 & 11 , and by further ensuring that the discrete male protuberance 44 in the smaller second tray member 2 โsnapsโ into the complementary female depression 46 of the first tray member 4 .
[0041] Turning to FIGS. 16 , 17 , 18 & 19 , therein are shown another rigid polymer construct embodiment of a further enhancement of the previously described embodiment of the present invention, the enhancement being the formation of a male protuberance 53 that is formed into the floor of the shaped channel 14 and a complementary female slot 54 formed to accept the male protuberance 53 . The coupling of the two tray members is further enhanced by the use of a snap-fit grip mechanical means. In these illustrations, shown formed into the male protuberance 53 is a discrete rib edge 56 that mechanically engages a corresponding complementary ledge 58 in the female slot 54 to help secure the smaller second tray member 2 to the first tray member 4 .
[0042] Turning to FIG. 20 , therein is shown a first container system 50 stacked upon a second container system 52 of the present invention. The dimensions and configuration of the base 48 of the tray member 4 are such that it permits a close fit with cavity 23 formed in the top of the lid member 2 . The stacking feature of the container system to facilitate transportation, as well as display at the market.
[0043] FIG. 21 shows a different embodiment of the present invention that does not utilize the smaller second tray members to act as a lid that mates with the mouth of the first tray member. As shown, there is illustrated a first tray member 4 to which is attached two smaller tray members 60 , 62 . The manner of attachment of the smaller tray members 60 , 62 to the first tray member 4 have previously been described.
[0044] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
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A container which includes a base ( 4 ) with an upper end forming a base rim ( 16 ), and a cover ( 2 ) which can lie right-side-up or upside-down on the base. In the cover upside-down position, a cover channel ( 14 ) opens downwardly and closely receives the base rim ( 16 ), and much of the base recess ( 7 ) is left uncovered.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a directional front projection screen.
2. Description of the Prior Art
A front projection screen receives a projected image from a lens and redirects this image to individual viewing zones which make up a larger viewing area.
Early front projection screens took the form of an opaque Lambertian white surface which reflected the projected image to a wide viewing area. Brighter portions of the image were reflected by the white surface to the viewers, whereas, the darker portions of the image were formed by the absence of light in the room. Consequently, the contrast ratio of the image depended upon the reflectivity of the screen and the ambient light level in a viewing room. Although this type of screen allows uniform brightness, light is reflected outside of the normal viewing range and consequently was inefficient.
Next, small glass beads were incorporated onto the the white surface which increased the reflectivity of the surface in the usable viewing area. This increase in reflecting efficiency is referred to as the gain of the screen. Although the beaded surface offered an improvement in optical performance, the material itself was subject to degradation with age and was easily injured.
The next development was the silver lenticular screen which had a reflective silvered surface corrugated for the purpose of expanding the horizontal viewing field by controlling direction of reflected light in the horizontal plane. This improved image contrast under high ambient light condition. The silvered lenticular screen offered lower gain than the beaded surfaces, however, it offered an improvement in terms of durability. This screen does not achieve the uniformity of brightness.
SUMMARY OF THE INVENTION
The front projection screen of the present invention comprises a translucent layer on top of or in a sheet or screen which incorporates light diffusing particles.
The front or first surface of the screen has a matte-finish to reduce specular reflection.
The second surface of the screen is configured as an incremental reflector.
In one embodiment, the facets which form the reflector are oriented to direct an image to a small audience occupying a narrow viewing zone.
In an alternate embodiment the facets which form the reflector are oriented to direct an image to a relatively large audience occupying a wide viewing area consisting of a number of viewing zones.
In this alternate embodiment the facets are arranged in clusters. Each cluster consists of a specified number of adjacent facets. Each facet within a cluster is oriented to direct light toward a different location or zone within the viewing area.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a cross-sectional view of the projection screen of the present invention.
FIG. 2 is a cross-section of the first embodiment of the present invention.
FIG. 3 is a cross-section of the second embodiment of the present invention.
FIG. 4 is a nomograph showing the facet angles for the second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a cross-section showing the structure of the present invention. The screen 1 is formed from a sheet incorporating translucent layer 2 containing a large number of light diffusing particles. This layer may be located within the sheet or coated onto the sheet. The first surface 3 of the sheet has a matte-finish to reduce specular reflection at this surface. This surface may be embossed or coated to achieve the matte finish.
The second or rear surface 4 is configured as a linear incremental specular reflector. The facets 5 of this incremental surface are separated by riser steps 6. A reflective material 7 such as aluminum is coated onto the rear surface 4 of the sheet to achieve a specularly reflective surface. Each facet is inclined at an angle ฮธ N varying with respect to a base line 8 which is parallel to the front surface 3 of the sheet.
For design purposes, geometric ray tracing techniques are used to calculate the desired angle ฮธ N for each facet. For these calculations the effect of the diffusing particles is ignored. Once the geometry of screen has been established the effect of the diffusing material is considered by superimposing a diffuse scattering lobe 9 around each of the design rays 10 at the exit point on the first surface of the screen.
The embodiment shown in FIG. 2 is used when the image projected from a source 20 is to be viewed by a small audience located in a narrow viewing zone 21.
In this instance the angle ฮธ N for any given facet is selected to direct light toward the specified viewing zone 21.
For example, rays 22, 23, 24 incident upon facets 25, 26, 27 located at various locations on screen 28 are directed toward viewing zone 21 by selection of an appropriate ฮธ for each of these facets.
In this embodiment the scattering effect represented by lobes 29, 33, 34 of the diffusion material of screen 28 define the size of viewing zone 21.
The embodiment shown in FIG. 3 is used when the image projected from source 30 is to be viewed by a larger number of observers located throughout the viewing area. Each observer A, B, C, D defines a selected viewing zone used for design calculations. The aggregate of viewing zones defines the useful viewing area.
For a typical projection T.V. application the incremental facets would extend vertically up and down on the screen. The screen itself may be slightly curved in the vertical plane to direct more light toward the audience. However, the horizontal distribution of light is determined by the facets. This simple one dimensional curvature is an advance over more complex compound curve screens.
The facets of screen 31 in this embodiment are arranged in clusters. Each cluster, 32, for example, includes a specified number of facets 32A, 32B, 32C, and 32D. Each facet is inclined at an angle ฮธ N to direct a portion of the image to particular viewing zone. For example, facet 32A of cluster 32 is inclined at an angle ฮธ such that it directs an incident ray toward viewing zone A. In a similar fashion facets 33A and 34A direct incident rays 36, 37 toward viewing zone A. In this manner individual facets located in various cluster located throughout the screen cooperate to selectively direct light to specified viewing locations.
The effect of the diffusing material incorporated in screen 31 is to blend the viewing zones into an approximately uniformly illuminated viewing area, such that the screen appears equally bright for all observers within the viewing area. The width of facets is dependent on the use of the screen. In general they are too small to be resolved by the veiwer. This contrasts sharply with prior art Lambertion screens in which screen brightness drops off rapidly as one moves away from the principal axis of the screen.
The shape of the diffusion lobes 38, 39, 40 depict the angular distribution of light or brightness around a selected ray. The shape of these distribution lobes is determined by concentration and type of diffusing material incorporated in screen 31. FIG. 4 is a nomograph showing the facet angles as a function of screen position for a specific design.
One suitable formulation for a screen according to this invention is given in the following example.
EXAMPLE
A composition containing 95 percent by weight of a medium hard cellulose acetate butyrate polymer and 5 percent by weight to lamellar microform quartz particles, was extruded on a 1.91 cm (0.75") Brabender extruder (manufactured by C. W. Brabender Instruments, Inc., Hackensack, NJ) into 0.0254 cm (0.010 inch), 0.0381 cm (0.015 inch) and 0.0508 (0.020 inch) thick film at the following temperature conditions;
Zone 1 at 180ยฐ C., Zone 2 at 195ยฐ C., Zone 3 at 210ยฐ C., Zone 4 at 200ยฐ C. and die at 200ยฐ C.
In a secondary platen pressing compression molding cycle, one side of each film was thermally embossed with a nickel electro-formed stamper containing a specially designed Fresnel lens while the opposite side was embossed with a chrome steel backplate containing a matte finish.
The compression molding was conducted in a steam heated-water cooled Wabash hydraulic press (Model 12-12-ST manufactured by Wabash Metal Products Company, Inc., Hydraulic Divison, Wabash, Ind.) to a maximum temperature of 143ยฐ C. (290ยฐ F.) and 14.1 kg per square centimeter (200 pounds per square inch) with a complete cycle time of approximately five minutes. The sandwich was cooled to 60ยฐ C. (140ยฐ F.), removed from the press, and separated from the stamper and backplate. The grooved surface was vapor deposited with 800 and 1000 A thickness of aluminum. An adhesive may be applied to the rear surface mechanically attaches the screen to a substrate.
The screen luminance and image contrast were determined according to ANSI/NMA MS-12 standard and compared to a metallic lacquer coated screen while mounted in a Realist "Valiant" projector (manufactured by Realist).
______________________________________LUMINANCE AVG. CORNER* CON-CNTR AVG. INT* TOP BOTTOM TRAST______________________________________10 Mil 200 53 18 18 4715 Mil 139 61 26 31 3620 Mil 91 73 43 44 42Lacquer 43 33 8 25 19______________________________________ *As a percentage of the Center in foot lamberts, intermediate and corner spots.
This is in sharp distinction with conventional prior art screens in which image brightness drops off as one moves away from the principal axis or projection axis of the screen.
As the thickness or amount of silica increases, the center brightness decreases, but the screen becomes more uniformly illuminated. The screen contrast of the diffusion Fresnel lens screen, for all film thicknesses, is approximately double that of the conventional reflecting lacquer screen.
It is also important to note that the Fresnel lens is designed in such a manner that the average screen top and screen bottom luminance values become uniform, while in the reflecting lacquer screen the screen top luminance is only one third that of the bottom. Thus the Fresnel lens has redirected the majority of the reflected light for off axis viewing.
To further enhance the uniformity of illumination, the screen of either embodiment may be curved slightly to control light distribution in the plane not controlled by the incremental surface.
Thus, to any single observer within the viewing area, the screen will appear uniformly bright, both from side-to-side and from top-to-bottom.
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A high gain, front projection screen with controlled light distribution, comprising a translucent sheet containing light diffusing particles, having a matte-finished front surface and an incremental reflector rear surface.
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CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims the benefit of and priority to French Patent Application No. 1550203, filed Jan. 12, 2015, which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] The invention relates to โactive implantable medical devicesโ as defined by the Directive 90/385/EEC of 20 Jun. 1990 of the Council of the European Communities, and particularly to implantable devices that continuously monitor heart rate and if necessary deliver electrical stimulation, resynchronization and/or defibrillation pulses to the heart in case of rhythm disorder detected by the device.
[0003] The invention relates especially, but is not limited to, those devices that are in the form of an autonomous capsule intended to be implanted in a heart chamber, including the ventricle.
[0004] These capsules are free of any mechanical connection to an implantable (such as a housing of the stimulation pulse generator) or non-implantable (external device such as programmer or monitoring device for patient remote monitoring) main device, and for this reason are called โleadless capsulesโ to distinguish the capsules from electrodes or sensors disposed at the distal end of a conventional probe (lead), which is traversed throughout its length by one or more conductors galvanically connecting the electrode or sensor to a generator connected to an opposite, proximal end of the lead. A detection/stimulation electrode in contact with the wall of the ventricle enables the capsule to detect the presence or absence of a spontaneous depolarization wave of the cardiac cavity, as well as the occurrence time of the wave (ventricular or atrial marker).
[0005] The electrode also allows the delivery of a stimulation pulse in the event of absent or late spontaneous depolarization, so as to cause contraction of the cardiac cavity.
[0006] Note, however, that the autonomous nature of the capsule is not inherently a necessary feature of the present invention.
[0007] The management of the stimulation energy is a critical aspect of any implantable pacemaker, because it has a direct impact on the power consumption of the integrated pacemaker battery, and thus on its overall lifespan.
[0008] This topic is particularly critical in the case of a leadless capsule pacemaker wherein, unlike conventional pacemakers, the energy required for the issuance of stimulation is 70% of the total energy consumed. In addition, it must be considered that the very small dimensions of a leadless capsule imposes minimizing the size of the battery and thus its capacity, as the battery often occupies more than 70% of the volume in a leadless capsule.
[0009] In fact, if it was possible to reduce, for example, half the energy required for stimulation, the size of the battery could correlatively be reduced about 40% while keeping the same longevity, which would reduce the volume of the capsule to about 0.6 cm 3 (compared to 1 cm 3 in the best case today), all performances being equal.
[0010] To minimize the energy dedicated to stimulation as much as possible, while maintaining the effectiveness of delivered electrical pulses, a technique called โcycle to cycle captureโ may be employed. Cycle to cycle capture maintains the stimulation energy at a minimum level, continuously checking, after each stimulation, if the stimulation was effective (โcaptureโ) or not. If no depolarization wave has been induced by stimulation of the cardiac cavity (โnon-captureโ), the implant delivers, during the same cardiac cycle, a stimulation of a relatively high energy to ensure the triggering of a depolarization. Then, by successive iterations, the stimulation energy is gradually reduced in each cardiac cycle, so as to converge again to an energy close to the limit or โtriggering thresholdโ needed to cause depolarization of the cardiac cavity.
[0011] The invention relates more precisely to a method to determine the pacing threshold by successive approaches, in the most efficient possible method from the energy consumption point of view.
[0012] The basic technique which is commonly used today in most pacemakers, is described in U.S. Pat. No. 3,777,762 A. The technique involves using a method of progressive decreases in amplitude (voltage) of the stimulation pulses for a fixed pulse width.
[0013] Another technique is described in U.S. Pat. No. 4,979,507 A. This technique relies on the fact that the delivered energy not only depends on the amplitude of the stimulation pulses, but also of the width of these pulses (stimulation duration). The pacing threshold varies as a function of these two parameters according to a nonlinear law called โLapicque lawโ.
[0014] The technique proposed in U.S. Pat. No. 4,979,507 A includes performing two amplitude scans, with two different pulse widths. This approach has a risk of capture default, because the theoretical Lapicque law defines a boundary between capture and non-capture that, in practice, varies from one patient to another. It is therefore necessary to validate either continuously or at regular intervals the method for each patient, by making a complete scan of all possible values of the parameters (amplitude and width of the stimulation pulse). However, a full scan is impractical because it is very costly in terms of energy and requires interrupting therapy during scanning.
[0015] WO 94/12237 Al discloses another technique for automatically adjusting the capture threshold wherein, again, the variation of the energy of one stimulation pulse to the next is made either by changing the duration of the pulse, or by changing the amplitude of the pulse. This significantly increases the number of iterations required for the search algorithm to determine the actual value of the stimulation threshold.
[0016] U.S. Pat. No. 5,718,720 A, U.S. Pat. No. 5,702,427 A, U.S. Pat. No. 5,549,652 A and U.S. Pat. No. 6,650,940 B1 describe other techniques for determining the pacing threshold, implementing various capture detection methods such as a direct detection of mechanical myocardial contraction, analysis of an accelerometric signal, analysis of a temperature signal, analysis of intracardiac pressure, etc.
SUMMARY
[0017] The object of the disclosure is to provide a new technology to search for an optimum of both parameters defining the energy delivered by the stimulation pulse, namely the stimulation voltage (the amplitude of the pulse) and the duration of the stimulation (the width of the pulse), in both the fastest and the most energy consumption saving method.
[0018] The problem to solve is minimizing the number of stimulations to deliver to determine the pacing threshold, so as to consequently reduce the power consumption of the implant in order to improve the overall lifespan.
[0019] The starting point of the disclosure is, in contrast to known search techniques which typically operate by scanning successive amplitude values for a given pulse width, simultaneously executing a search algorithm in two dimensions (width and amplitude pulse). This algorithm allows for the possibility of varying both parameters of a stimulation pulse to the next stimulation pulse according to a mechanism that depends on the result (presence or absence of capture) of the previous stimulation.
[0020] As will also be seen, the disclosure provides such an algorithm iteratively operating by dichotomy, on the basis of a minimization of the total energy of the pulse, and not only the minimization of the voltage of the pulse.
[0021] More specifically, the invention proposes an active implantable medical device including:
a ventricular stimulation circuit adapted to deliver low energy pacing pulses to an implantable electrode within a heart chamber of a patient; a capture test circuit adapted to detect, during a cardiac cycle, the presence or absence of a contraction subsequent to the application of a stimulation pulse; and an adjusting circuit capable of independently controlling the stimulation voltage and the stimulation pulse width of the energy pulses delivered by the stimulation circuit.
[0025] In one embodiment, the adjustment circuit is configured to implement an iterative algorithm to re-search for optimum energy and is capable of modifying both the pulse width t and the voltage V of each new delivered pulse. The adjustment circuit is configured to, at each current iteration, perform the following actions:
set a value {t,V} of high energy; set a value {tโฒ,Vโฒ} of low energy, with tโฒ<t and Vโฒ<V; deliver a pacing pulse with the low energy value, then perform a capture test; and
in the presence of a capture, end the current iteration and transition to a new iteration, with the current low energy as the new high energy value, in the absence of capture, i) apply a consecutive r stimulation pulse of pulse width t and of voltage V defined for said high energy value, and ii) the algorithm and select the last energy value that produced the capture as the optimum energy value.
[0031] In a preferred embodiment, the adjustment circuit is further configured to perform the following actions:
set a first intermediate energy value {tโฒ,V}; set a second intermediate energy value {t, Vโฒ}; set a third intermediate energy value {tโณ,Vโณ}, with tโฒ<tโณ<t and Vโณ<Vโณ<V rank the first, second and third intermediate energy values by decreasing energy value; and in the absence of capture after delivery of the pulse with low energy value and capture test, continue the current iteration with delivery of pacing pulses in succession with the first, second and third intermediate energy values sorted by decreasing value of energy to detect a capture; and
in the presence of a capture, end of the current iteration and transition to a new iteration with the current intermediate energy that produced the capture as a new high energy value, in the absence of capture, complete the algorithm and selection of the last value of energy produced with the capture among the first, second and third intermediate energy values as the optimum energy value.
[0039] The third intermediate energy value may be a value {tโณ,Vโณ} such that tโณ=(t+tโฒ)/2 and Vโณ=(V+Vโฒ)/2.
[0040] According to various advantageous subsidiary embodiments:
the energy values of the pulses delivered by the stimulation circuit are, at most, equal to a maximum energy limit value, and the high energy value {t,V} in the first iteration of the algorithm is the maximum energy limit value; the energy values of the pulses delivered by the stimulation circuit are at least equal to a minimum energy limit value {tL,VL} (L), wherein said low energy value is a value {tโฒ,Vโฒ} such that tโฒ=(t+tL)/2 and Vโฒ=(V+VL)/2; the energy values of the pulses delivered by the stimulation circuit are between a maximum energy limit value and a minimum energy limit value calculated before each first iteration of the algorithm; in the latter case, the pulse width and the voltage of the maximum energy value and of the minimum energy value are calculated by the application of multiplication factors, respectively the upper and lower unit of the current pulse width and of the current voltage of the stimulation circuit before the first iteration of the algorithm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Further features, characteristics and advantages of the present invention will become apparent to a person of ordinary skill in the art from the following detailed description of preferred embodiments of the present invention, made with reference to the drawings annexed, in which like reference characters refer to like elements and in which:
[0046] FIG. 1 is an overall perspective view of a leadless capsule.
[0047] FIG. 2 is a longitudinal cross sectional view of the leadless capsule of FIG. 1 showing the main internal components.
[0048] FIG. 3 is a series of timing diagrams illustrating an electrogram EGM signal, the detection windows for the capture test and the endocardial acceleration EA signal.
[0049] FIG. 4 is a three-dimensional representation of the energy expended by the application of a stimulation pulse, depending on the amplitude and width of the stimulation pulse.
[0050] FIG. 5 is a two dimensional representation, as a function of the amplitude and the width of successive stimulation pulses, of the dichotomy search technique according to the disclosure, with, for each iteration, concurrently changing the amplitude and the width of the delivered pulse.
[0051] FIG. 6 is a representation of the algorithm of FIG. 5 applied to a first illustrative implementation.
[0052] FIG. 7 is a voltage/pulse width diagram corresponding to the example of FIG. 6 , to which isoenergetic curves have been added.
[0053] FIG. 8 is similar to FIG. 6 , applied to a second illustrative implementation of the disclosure.
DETAILED DESCRIPTION
[0054] An exemplary embodiment of the device of the disclosure will now be described.
[0055] Regarding its software aspects, the disclosure may be implemented by appropriate programming of the controlling software of a known cardiac pacemaker, for example an endocardial leadless capsule.
[0056] These devices include a programmable microprocessor provided with circuits for shaping and delivering stimulation pulses to implanted electrodes. It is possible to transmit software to the device by telemetry that will be stored in memory and executed to implement the functions of the disclosure which will be described below. The adaptation of these devices to implement the functions of the disclosure is within the reach of a skilled-in-the-art person and will not be described in detail. In particular, software stored in memory and executed can be adapted and used to implement the functions of the disclosure which will be described below.
[0057] The method of the disclosure is implemented primarily by software, through appropriate algorithms performed by a microcontroller or a digital signal processor. For the sake of clarity, the various processing applied will be decomposed and schematized by a number of separate functional blocks in the form of interconnected circuits, but this representation, however, is only illustrative, these circuits including common elements in practice correspond to a plurality of functions generally performed by the same software.
[0058] FIGS. 1 and 2 respectively show, in perspective and in longitudinal cross section, an example of a leadless capsule.
[0059] In these figures, the reference 10 generally designates the capsule, formed as a cylindrical tubular body 12 of axis 4 enclosing the various electronic circuits and power supply of the capsule. Typical dimensions of such a capsule are a diameter of about 6 mm and a length of about 25 mm.
[0060] At its distal end 14 , the capsule includes a helical anchoring screw 16 for fixing the capsule into tissue, for example against a wall of a heart chamber. The helical anchoring screw 16 can optionally be an active, electrically conductive screw for collecting the potential of cardiac depolarization and/or for the application of stimulation pulses. The proximal region 18 of the capsule 10 has a rounded, atraumatic end 20 and is provided with grips 22 , 24 suitable for implantation or removal of the capsule.
[0061] As shown in FIG. 2 , the capsule 10 incorporates a battery 26 , typically with a volumetric energy density of the order of 0.8 to 2 kg/cm 3 , an electronic module 28 , a front electrode 30 , and optionally a side electrode 32 . Feedthroughs such as 34 are used to connect the electrodes to the electronic module 28 .
[0062] The electronic module 28 includes all of the electronics for controlling the various functions of the implant, storing the collected signals, etc. It includes a microcontroller and an oscillator generating the clock signals necessary to the operation of the microcontroller and communication. It also contains an analog/digital converter and a digital storage memory. It may also contain a transmitter/receiver for exchanging information with other implantable devices by HBC (Human Body Communication, intracorporeal communication) communication.
[0063] The capsule 10 also includes a endocardial acceleration (EA) sensor 36 capable of delivering a signal representative of the mechanical activity of the myocardium, for example a microaccelerometer shaped sensor interfaced with the electronic module 28 .
[0064] The sensor of EA signal 36 can be a 1D, 2D or 3D accelerometric sensor. Preferably, the sensor is a piezoelectric or a capacitive sensor, but other types of sensors (optical, resistive, inductive, etc.) capable of generating a signal correlated to the displacement, velocity or acceleration of the heart walls may be used.
[0065] FIG. 3 shows a series of timing diagrams illustrating an electrogram (EGM) signal, detection windows W DET for the capture test, and the endocardial acceleration (EA) signal.
[0066] After each stimulation (marker V of stimulated depolarization on the EGM), the measurement of the EA signal delivered by the accelerometer is activated for a W DET window which is open either immediately after the issuance of the stimulation pulse, or with a delay ฮด on the order of 5 to 100 ms. The length F of the window W DET is between 75 and 350 ms. Controlling the start time of the capture window W DET and its duration is achieved via a sequencing circuit of the microcontroller and the embedded software which controls the electronic circuits of the implant.
[0067] EP 2412401 A1 (Sorin CRM) discloses a capture test technique by analyzing a signal EA, including successive components (EA components) of the signal which correspond to the major heart sounds that can be recognized in each cardiac cycle (S1 and S2 sounds of a phonocardiogram). The amplitude variations of the first component (EA1 component) are closely related to changes in pressure in the ventricle, while the second component (EA2 component) occurs during the isovolumetric ventricular relaxation phase. The analysis can also take into account the secondary component (called EA4 or EA0) produced by the contraction of the atrium.
[0068] These components are analyzed to extract various relevant parameters such as the peak-to-peak of the PEA1 and PEA2 peaks of the EA1 and EA2 components, the temporal interval between these PEA1 and PEA2 peaks, the half-height width of the EA1 and/or EA2 components, the instants of beginning and ending of these components, etc. It may also be representative of morphological parameters of the waveform of the EA signal or of its envelope.
[0069] This capture technique by analyzing an EA signal is not, however, limitative of the disclosure and one can for example proceed as described for example in EP 0552357 A1 (ELA Medical) by analysis of EGM signals of depolarization of the myocardium to recognize the presence or absence of an evoked wave consecutive to the application of the stimulation pulse.
[0070] The basic concept of the disclosure, unlike known techniques which often operate a scanning of the amplitude of the stimulation pulse at constant pulse width, is to operate a search algorithm simultaneously in two dimensions (amplitude and pulse width).
[0071] The energy expended by the delivery of a stimulation pulse amplitude of voltage V and of width t is given by:
[0000]
E
๎ข
(
V
,
t
)
=
V
2
๎ข
t
R
[0000] R being the impedance of the heart tissue between the two stimulation electrodes.
[0072] FIG. 4 shows the variation of the energy E expended by a pacing pulse as a function of the two parameters V and t. This representation includes two areas, with a capture zone ZC, wherein the energy delivered is sufficient to cause myocardial contraction, and a non-capture area ZNC, wherein this stimulation energy was not sufficient to cause myocardial contraction. These two zones are separated by a border CL, corresponding to the theoretical Lapicque's curve, which is a nonlinear theoretical boundary that may vary from one patient to another. In the capture zone ZC, the stimulation energy increases with the voltage and the pulse width, according to a nonlinear relation.
[0073] The energy E(V, t) is the power actually dissipated in the impedance R, that is to say, in the heart tissue. The energy actually consumed by the electric power source, E p (V, t), of the implant (battery or rechargeable battery) is equal to:
[0000]
E
p
๎ข
(
V
,
t
)
=
V
2
๎ข
t
ฮท
๎ข
(
V
)
๎ข
R
[0000] wherein r i (V) is the yield of the circuit for generating the stimulation voltage V.
[0074] The search technique of optimum energy by dichotomy according to the disclosure will now be explained with reference to FIG. 5 .
[0075] The purpose is to achieve, in a minimum number of steps, the stimulation conditions (pulse amplitude and width) that minimize the energy necessary for the issue of pulses providing an effective capture.
[0076] It is assumed that the stimulation circuit is adjusted at a given instant, with current pacing parameters t c and V c corresponding at point S of coordinates {t c , V c }.
[0077] Point L represents the minimum pacing energy value to be tested during the research phase, this point preferably being defined according to the point S (the position L is not fixed but depends on the current stimulation energy):
[0000] {right arrow over (L)} =(ฮฑ 1 t c , ฮฑ 2 V c )
[0000] wherein ฮฑ1 and ฮฑ2 are constants lower than unity. Typical values for ฮฑ1 and ฮฑ2 are, for example, ฮฑ1=ฮฑ2=2/3. Other values closer to zero could help the search of points with lower energy, but with a longer search phase (energetically more expensive).
[0078] In the case of loss of capture at the current point S (which is the case in the example of FIG. 5 , since the point S is located below the Lapicque's curve CL for the considered patient (the curve that defines the border between capture zones ZC and non-capture zones ZNC)), a rectangular window ADBC is defined, from both points A and B.
[0079] Point B is chosen such that:
[0000] {right arrow over (B)} =(ฮฒ 1 t c , ฮฒ 2 V c )
[0000] wherein ฮฒ1 and ฮฒ2 are constant superior to unity.
[0080] Point B establishes a maximum energy limit to be tested in the search phase, which is energy dependent, as the minimum energy at the point L, on the position of the current point S. Point B is determined to correspond to an energy wherein it is certain that the stimulation will be effective, which is the case if, for example, ฮฒ1=4 and ฮฒ2=2.
[0081] Point A is chosen as the middle of the segment LB:
[0000]
A
โ
=
L
โ
+
B
โ
2
[0000] Point M is defined as the center of the rectangle ADBC:
[0000]
M
โ
=
A
โ
+
B
โ
2
[0000] Point D of the rectangle ADBC is the point defined by t D =t A , and V D =V B , and point C is the point defined by t C =t B and V C =V A (ADBC the being a rectangle domain).
[0082] Four test points are defined to implement the search algorithm, namely points A, M, C and D. Point B will be considered a โrescue pointโ in case of detection of lack of capture. The device immediately applies a counter-stimulation with an energy corresponding to that of point B to compensate for loss of capture and to be certain that the counter-stimulation pulse is a capturing pulse.
[0083] The search for the best point of the four test points A, M, C and D is performed in the order of increasing energy cost, with iterations of the search algorithm according to the following steps:
1) The standby point Bโฒ of the possible next iteration of the search algorithm is defined, which will be point Bโฒ=B; 2) Point A is tested first because it costs less energy than the other points D, M or C, the voltage and/or amplitude being lower in A than in the three other points. Therefore stimulation with the energy corresponding to the point A is applied; 3) If a capture is detected during the test at point A, the following points D, M and C are not tested, and a new rectangle AโฒDโฒBโฒCโฒ is defined with Bโฒ=A, its center being Mโฒ; 4) In case of lack of capture during the test at point A, we calculate energy values proportional to the theoretical energy that stimulation at points D, M and C cost, according to the formula E p (i)=V(i)*V(i)*t(i), i being a point among D, M and C. 5) The three points D, M and C are classified according to the values E p (i) calculated in the preceding step, in descending order, which gives three points X1, X2 and X3 such that:
[0000] [ X 1, X 2, X 3 ]=tri ({ D, M, C }), with E p ( X 1)< E p ( X 2)< E p ( X 3) 6) Point X1 is then tested. If a capture is detected, no test is carried out on the point X2 and X3 and a new rectangle is defined, with Bโฒ=X1; 7) In the opposite case, a counter-stimulation is applied (point B) to compensate for loss of capture, and then point X2 is tested at the next cycle; 8) If a capture is detected at point X2, no test is performed on point X3 and a new rectangle is defined, with Bโฒ=X2; 9) Otherwise, a counter-stimulation is applied (point B) to compensate the loss of capture and then point X3 is tested at the next cycle; 10) If a capture is detected at the point X3, a new rectangle is defined, with Bโฒ=X3; 11) If a capture was detected at one of the points X1, X2 or X3, the above procedure of steps 1) to 10) is iterated, with B=Bโฒ and A=(L+B)/2, that is to say that A is the midpoint of segment LBโฒ; 12) If after any reiteration of test no point has produced capture, then the search algorithm is terminated and the last point B that produced the capture is defined as the optimal energy value.
[0096] In a simplified variant, the algorithm is stopped after the first test point which causes a loss of capture. The number of steps can thus be reduced, resulting in less energy consumed.
[0097] FIGS. 6 and 7 are representations of the algorithm of FIG. 5 applied to a first illustrative implementation (on FIG. 7 , the isoenergetic curves were added to the representation of FIG. 6 ).
[0098] Successive test points are numbered in the order 1, . . . , 9, and the points for which no capture was detected are shown by triangles in FIG. 6 .
[0099] It is noted that, in this example, after nine iterations the algorithm has converged towards point 5 {0.8 V, 0.75 ms}, which will be the point chosen as energy optimum. During these nine iterations, five points did not cause a capture (points No. 4, 6, 7, 8, and 9), and the backup point (point 1) was used for the counter-stimulation.
[0100] In FIG. 8 another example is shown, wherein the algorithm converges after seven iterations, the point finally selected as the energy optimum being point 3 (the last point with capture).
[0101] In the simplified version of the algorithm mentioned above (which consists in stopping the algorithm from the first point that does not generate capture), the algorithm ends after only four iterations, the point being selected as the energy optimum being point 3, that is to say in this case (but not necessarily, in general) the same point as in the full variant of the algorithm.
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The disclosure relates to a device including a circuit for adjusting the energy of the stimulation pulses, independently controlling the pulse width and the voltage of each stimulation pulse. An iterative search algorithm for determining the optimum energy includes changing both the pulse width and voltage at each new pulse delivered, by setting a high energy value and a low energy value, and delivering a stimulation pulse with the low energy value. A capture test is then carried out. In the presence of a capture, a current iteration is complete and a new iteration is done with the current low energy as a new high energy value. In the absence of capture, the algorithm is terminated with selection of the last energy value that produced the capture as the value of optimum energy.
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to safety systems and methods in general and, more particularly, to a safety system and method for use with conductive members when used in the presence of power lines.
SUMMARY OF THE INVENTION
A safety system and method for use with apparatus having a conductive member, where said apparatus changes the attitude and/or altitude of the conductive member during the operation of the apparatus, includes at least one sensor mounted on the conductive member. The sensor will sense an electric field and provide a signal representative of the strength of the sensed electric field. Further changing of the conductive member's attitude and/or altitude is prevented in response to the signal from the sensor when the electric field strength is greater than a predetermined safe value.
The objects and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein one embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration purposes only and are not to be construed as defining the limits of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial representation of a truck mounted derrick having a safety system constructed in accordance with the present invention.
FIG. 2 is a simplified block diagram of the safety system shown in FIG. 1.
FIGS. 3A through 3D illustrate schematically different types of sensors which may be used with the present invention.
DESCRIPTION OF THE INVENTION
There have been fatal accidents in the oil field with drilling and with well service groups due to raising derricks and masts of drilling and workover rigs into electrical power lines. This safety problem is not unique to the oil industry but is also applicable to other industries where devices such as cherry pickers used by power companies, tree surgeons, plus construction cranes and other conductive masts or devices, accidentally come in contact with power lines. Nor is the present invention restricted to devices located on trucks but is also applicable to a situation where a conductive member may be raised in the presence of a power line. A conductive member for purposes of the present invention is any member whose structure is conductive or whose structure is non-conductive but has other means of conduction such as wires and cables. The present invention provides a method of preventing this type of accident and at the same time warning the operator that the rig is in a hazardous situation.
Referring now to FIG. 1, there is shown a typical service conductive member such as a derrick 3 mounted on a truck 1 which is raised to an operating position by conventional means. Located at strategic points on derrick 3 are any number of sensors represented by sensors 7, 7A, and 7n, which are electrically connected to an electronic system 10. As derrick 3 is raised during normal operation and it approaches power lines, sensors 7 through 7n will have voltages induced by the electric field created by the power lines and provides signals to electronic systems 10. When the electric field is strong enough electronic systems 10 will stop the raising of derrick 3 and sound an alarm audibly and visibly as hereinafter explained.
With reference to FIG. 2, sensors 7 through 7n in the presence of an electric field provides signals to a multiplexing unit 14 of electronics system 10 which multiplexes the signals to approximately 1 second samples. The multiplexed signal is then provided to a narrow band filter and amplifier 17 which filters the multiplexed signal so that only a signal associated with the power lines is provided to a maximum signal level circuit 23. Circuit 23 is of a conventional type and its detail is not necessary to an understanding of the present invention. Maximum signal level circuit 23 may be overriden by an override signal from an override signal means 25 which may be a simple on/off switch receiving a direct current voltage for application to the maximum signal sensing circuit 23. A sensitivity control signal means provides a signal to maximum signal level circuit 23 for adjusting the sensitivity of maximum signal level circuit 23. Maximum signal level sensing circuit 23 provides a brake signal to actuator means 32, which is part of the conventional raising means, which also receives a hoist enable signal from hoist enable signal means 37 when derrick 3 is being raised. The brake signal from actuator means 32 is provided to brake actuator means 44 and to alarm means 48. Alarm means 48 may provide either an audio alarm, a visual alarm or both.
In operation, an operator wishing to raise derrick 3 causes hoist enable signal means 37 to provide a hoist enable signal to actuator means 32 which raises derrick 3. When derrick 3 approaches a power line, the electric field around that power line causes sensors 7 through 7n to provide signals to multiplexing unit 14 having amplitudes corresponding to the intensity of the electric field. Multiplexing unit 14 provides a multiplexed signal to narrow band filter and amplifier 17 which in turn provides the filtered signal to maximum signal level circuit 23. Any one of the sensors 7 through 7n providing a signal that is greater than a predetermined safety level causes maximum signal level circuit 23 to provide a signal to actuator means 32 disabling actuator means 32 and causing actuator means 32 to provide the brake signal to brake actuator means 44 and alarm means 48. Brake actuator means 44 stops the movement of derrick 3, while alarm means 48 sounds an alarm that derrick 3 has approached a power line. Should sensors 7 through 7n provide such a signal and the operator in his judgment can see that he can safely raise derrick 3 in the presence of the power line with safety, he may then utilize override contol means 25 to provide an override signal to maximum signal level sensing circuit 23 which then is deactivated to allow actuator means 32 to continue to raise derrick 3. The operator would also use the override signal when lowering derrick 3 after the derrick has entered a strong electric field.
Although the system of the present invention has been shown as having multiple sensors, a single sensor appropriately placed on derrick 3 may also be utilized in which case multiplexing unit 14 would not be necessary and the signal from the single sensor may be applied directly to narrow band filter and amplifier 17.
FIGS. 3A, 3B, 3C and 3D show different types of configurations for sensors 7, although the specific configuration of sensor 7 is not restricted to any one of four types shown, but is restricted to a sensor which will produce a signal in the presence of an electric field that is representative of the strength of the electric field.
The present invention as hereinbefore described is a safety system for use with an aerial truck which utilizes a derrick or a conductive structure which is raised from one position to another position during the course of operation and which may come into contact with electric power lines and cause injury and death to the operators of such apparatus.
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A safety system for use with apparatus having a conductive member and where the apparatus changes the attitude and/or altitude of the conductive member during its operation includes at least one sensor which senses an electric field and provides a signal representative of the strength of the electric field. A safety device responsive to the signal from the sensor prevents the further changing of the conductive member's attitude and/or altitude when the electric field strength is greater than a predetermined safe value.
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This application is a continuation of application Ser. No. 08/103,326 filed Aug. 9, 1993, abandoned, which is a continuation of Ser. No. 07/874,110 filed Apr. 27, 1992, abandoned, which is a divisional of Ser. No. 07/598,519 filed Oct. 17, 1990, now abandoned,
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a portable electronic apparatus, such as a laptop computer or a portable word processor.
2. Description of the Related Art
A portable computer disclosed in U.S. Pat. Nos. 4,864,523, 4,895,231, 4,901,261 or 4,951,241 has a base unit and a display unit pivotally connected to the base unit. The base unit has a keyboard. The display unit is able to rotate between a closed position where the display unit covers the keyboard and an open position where the keyboard is exposed and is able to be operated.
The portable computer has a U-shaped handle assembly. The handle assembly has a pair of legs slidably connected to the computer and a handle interconnecting with the legs. The handle assembly is able to slide between a stored position where the handle contacts the computer and the projected position where the handle is gripped by an operator. The computer has a pair of leg storing portion. The legs are almost wholly stored in the leg storing positions in the stored position, respectively. The computer which has a U-shaped handle assembly is big because the computer has two leg storing portions.
The computer has a floppy disk drive (FDD) and a hard disk drive (HDD). The FDD and HDD are disposed on a same inner surface in the computer, respectively. Consequently a width of the computer is not able to be smaller than a sum of widths of the FDD and HDD.
The computer has a tilt assembly which is slidably moved between a tilting position where the keyboard is tilted forwardly and a untilting position where the keyboard is not tilted. The tilt assembly is big because the tilt assembly is rotated between the tilting position and the untilting position.
The display unit has an outer case and an inner case. The outer case is coupled to the inner case by a screw. The screw is covered by a flexible resin cover. The resin cover is removably fixed to the display unit. But the resin cover is hard to remove from the display unit because the engagement of the resin cover and the display unit is tough.
The keyboard of the computer has character keys and function keys. The character keys and function keys are separated by partition wall. When the computer is small, the partition wall is thin. When the partition wall is thin, the wall bends. If the wall is bends, the wall contacts the keys and an ability of an operation of the keys is worse.
The computer has an expansion card storing portion. After an expansion card is installed in the portion, a resin cover covers the portion. But the cover Is not electrically connected to the card. Consequently the expansion card generates an electromagnetic wave.
SUMMARY OF THE INVENTION
It is a first object of the present invention to provide a portable electronic apparatus having a small leg storing portion of a handle assembly.
It Is a second object of the present invention to provide a portable electronic apparatus including a base unit having a floppy disk drive and a hard disk drive which is arranged on the floppy disk drive.
It is a third object of the present invention to provide a portable electronic apparatus having a small tilt assembly which is not rotated.
It is a fourth object of the present invention to provide a portable electronic apparatus having a flexible screw cover which is easy to remove from the computer and toughly engages the cover and the computer.
It is a fifth object of the present invention to provide a portable electronic apparatus including a keyboard having character keys and function keys and a thin partition which is prevented bending.
It is a sixth object of the present invention to provide a portable electronic apparatus having an expansion card storing portion and a cover which prevents generating a electromagnetic wave of an expansion card.
In order to achieve the first object, a portable electronic apparatus of the present invention comprises a base unit including a handle storing portion and a leg storing portion, T-shaped handle assembly including a leg which is stored in the leg storing portion and connected to the base unit and has a longitudinal axis and handle connecting portion and a handle which is stored in the handle storing portion and is slidably connected to the handle connecting portion. The handle is able to slide in a direction of the longitudinal axis and rotate between a stored position where the handle and the leg are stored in the handle storing portion and the leg storing portion, respectively, and a projected position where handle is gripped by an operator. According to the apparatus of the present invention, the handle assembly is stored in a compact space because the handle is able to slide in the direction of the longitudinal axis.
In order to achieve the second object, a portable electronic apparatus of the present invention comprises a base unit which has a first mounting portion, a first disk drive which is mounted on the first mounting portion, a drive housing which has a second mounting portion, a second disk drive which is fixed on the first mounting portion, a first screw which fixes the first disk drive and the drive housing on the first mounting portion and a second screw which fixes the second disk drive on the second mounting portion. According to the portable electronic apparatus of the present invention, a width of the apparatus is not affected by widths of the first and the second disk drives.
In order to achieve the third object, a portable electronic apparatus of the present invention comprises a base unit having a tilt leg storing portion and a keyboard, a tilt leg which is slidably connected to the base unit between a tilting position where keyboard is tilted forwardly and a storing position where the tilt leg is stored in the tilt leg storing portion, a flexible board which is engaged the leg in the tilting position and the storing position and a switch releasing the engagement of the leg and the board. According to the apparatus of the present invention, the leg storing portion of the base unit is compact because the leg is not rotate.
In order to achieve the fourth object, a portable electronic apparatus of the present invention comprises a display unit including an outer case having a screw engaging portion and an inner case which has a cover storing portion having a cover storing surface having a through hole for screw and a cover engaging hole and a cover which has a thick portion and a thin portion having a claw which is engaged with the cover engaging hole. An inner surface of the thin portion is not contact with the storing surface. When the thin portion is pushed by an operator, the thin portion is bent. When the thin portion is bent, the claw which is engaged with the cover engaging hole is released from the cover engaging hole.
In order to achieve the fifth object, a portable electronic apparatus of the present invention comprises a base unit including a keyboard which has a character keys, function keys and a engaging hole and a front top cover which has a partition wall which has a engaging claw engaged with the engaging hole. When the front top cover is mounted on the keyboard, the engaging claw is engaged with the engaging hole and the partition wall is not bent.
In order to achieve the sixth object, a portable electronic apparatus of the present invention comprises a base unit including a card storing portion having a first connector which is electrically connecting an expansion card and a first inner surface, a cover which covers the card storing portion and has a second inner surface having a spring. The spring pushes and fixes the expansion card in a direction of the first inner surface and electrically connects the expansion card and the cover.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate a presently preferred embodiment of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principle of the invention.
FIG. 1 is a perspective view of a laptop computer according to an embodiment of the present invention;
FIG. 2 is a perspective view of the laptop computer when a display unit is set in a closed position. A handle assembly is set in a projecting position and a tilt leg assembly is set in a stored position;
FIG. 3 is a perspective view for explaining a movement of a handle of the handle assembly;
FIG. 4 is a sectional view taken along line W--W of FIG. 3;
FIG. 5 is a perspective bottom view of FIG. 2;
FIGS. 6A-8C are sectional views taken along line VI--VI of FIG. 5 for explaining a movement of the handle assembly;
FIG. 7 is an exploded perspective view of a tilt leg assembly;
FIGS. 8A-8C are sectional views taken along line VIII--VIII of FIG. 5 for explaining a movement of the tilt leg assembly;
FIG. 9 is an exploded perspective view of a disk drive assembly;
FIG. 10 is a perspective view of a front top cover;
FIG. 11 is a top view of a keyboard;
FIG. 12 is a perspective view of a card storing portion and a storing portion cover;
FIG. 13 is a top view of an expansion card;
FIG. 14 is a sectional view for explaining a storing condition of the expansion card;
FIG. 15 is a perspective view of a display leg and a screw cover; and
FIGS. 16A-16C are sectional views for explaining a movement of a claw of the screw cover.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a perspective view of a laptop computer.
A laptop computer 5 has a base unit 3 and a display unit 9. Base unit 3 has a front portion 1. A keyboard 11 and a front top cover 13 are fixed on the front portion 1. A handle assembly 15 is pivotally connected to a front end of the base unit 3. Base unit 3 has a rear top surface 17 and a display leg mounting surface 19. A side wall 21 of base unit 3 has a floppy disk drive (FDD) 23 and a tilt leg release switch 26. A rear portion of a bottom surface of base unit 3 has a tilt leg 25. Tilt leg 25 is slidable in a direction of an arrow A. Base unit 3 has a right center wall 37 and a left center wall 39. Light electroluminescence devices (LEDs) 41 are mounted in a corner between left center wall 39 and rear top surface 17. Display unit 9 has a display leg 7. Display leg 7 is mounted on mounting surface 19. Display unit 9 is pivotally connected to base 3 by display leg 7. Display unit 9 has an inner case 27, an outer case 29, display surface 31, a display latch claw 32 and a screw cover 33. Screw cover 33 is removably fixed on display leg 7. A height B between rear top surface 17 and the bottom surface of base unit 3 is higher than a height C between a front top surface 35 and the bottom surface.
FIG. 2 is a perspective view of the laptop computer when the display unit 9 is set in a closed position, the handle assembly 15 is set in a projecting position and the tilt leg 25 is set in a stored position.
Display unit 9 rotates between an open position (shown in FIG. 1) for exposing and operating keyboard 11 and a closed position (shown in FIG. 2) for covering keyboard 11. When display unit 9 is set in the closed position, an outer surface of outer case 29 and rear top surface 17 are maintained at a common height level. Tilt leg 25 slides between a tilting position (shown in FIG. 1) for tilting keyboard 11 forwardly and an stored position (shown in FIG. 2) for untilting keyboard 11. Handle assembly 15 has a handle axis portion 43, a leg portion 45 which is fixed to handle axis portion 43 and handle portion 47 which is slidably connected to leg portion 45. Handle assembly rotates between a storing position (shown in FIG. 1) for storing handle assembly 15 and a projecting position (shown in FIG. 2) for gripping handle portion 47.
FIG. 3 is a perspective view for explaining a movement of the handle assembly.
A side surface 49 of leg portion 45 has a rectangle hole 51 and an engaging groove 53. Handle portion 47 is slidably connected to rectangle hole 51. Handle portion slides between a handle gripping position (shown by a continuous line) and handle storing position (shown by a dotted line).
FIG. 4 is a sectional view taken along line IV-IV of FIG. 3.
Handle portion 47 has a metal axis portion 55, a resin portion 57 for connecting metal axis portion in rectangle hole and a rubber portion 57 covering resin portion 57.
FIG. 5 is a perspective bottom view of FIG. 2.
A bottom surface 59 of base unit 3 has a leg storing groove 61 and a handle storing groove 82 in a front end. Handle portion 47 is stored in groove 82 in the handle storing position. In the front end, bottom surface 59 has a switch storing portion 65 and a release switch 83 stored in switch storing portion 65. A rear end of bottom surface 59 has a pair of tilt leg storing portions 67. A card storing portion cover 89 is fixed on bottom surface 59 by screw 71.
FIGS. 6A-6C are sectional views for explaining a movement of the handle assembly.
FIG. 6A is a sectional view taken along line VI-VI of FIG. 5. One end of a flat spring 77 is fixed on an inner surface 73 of base unit 3 by a screw 75. Inner surface 73 has an opening 79. The other end of flat spring 77 inserted In opening 79. The other end of spring 77 pushes leg portion 45 in a direction of an arrow D. Switch storing portion 65 has a side opening 65a. One end of release switch 63 has a latch claw 83. Latch claw 83 is inserted in side opening 65a. Latch claw 83 is engaged with engaging groove 53. Release switch 83 is slidable in a direction of an arrow E. The other end of release switch 63 has a spring holder 87. A coil spring 89 Is wound around spring holder 87. Coil spring 89 pushes release switch 63 in a direction of an arrow F. When an operator slides release switch 63, as shown in FIG. 6B, latch claw 83 is released from engaging groove 53. Coil spring 89 is contracted. When latch claw 83 is released, leg portion 45 projects from leg storing groove 61 by a force of flat spring 77. When the operator releases switch 63, as shown in FIG. 6C, release switch 63 returns to a position shown in FIG. 6A by a force of coil spring 89.
FIG. 7 is an exploded perspective view of tilt leg assembly.
Bottom surface 59 has a slit 91. Tilt leg 25 is inserted in slit 91. Tilt leg has a slit 93. One end of slit 93 has a first groove 95 for fixing tilt leg 25 in the stored position. The other end of slit 93 has a second groove 97 for fixing tilt leg 25 in the tilting position. Side wall 21 has a slit 99 for inserting release switch 26. Tilt leg release switch 26 has a head portion 101, a stopper portion 103 and a projecting portion 105. Head portion 101 is inserted in slit 99 and projected from side wall 21. Stopper portion 103 prevents release switch 26 falling out from slit 99. A leg holder 107 slidably supports tilt leg 25 in a direction of an arrow G. Leg holder 107 includes a elastic portion 109 having a engaging portion which is engaged in first and second grooves 95, 97. A flat spring 111 is fixed on leg holder 107. Flat spring 111 pushes the engaging portion in a direction of an arrow H. Leg holder 107 is fixed on inner surface 78 of base unit 3.
FIGS. 8A-8C are sectional views for explaining a movement of the tilt leg assembly.
FIG. 8A is a sectional view taken along line VIII-VIII of FIG. 5. When tilt leg 25 is stored in the storing position, the engaging portion of elastic portion 109 is engaged with first groove 95. Tilt leg fixed in the storing portion because the engaging portion is pushed in a direction of an arrow H by flat spring 111. When an operator pushes head portion 101 of release switch 26 in a direction of an arrow J, as shown in FIG. 8B, projecting portion 105 pushes the engaging portion of elastic portion 109 and the engaging portion is released from first groove 95. When the engaging portion is released, tilt leg 25 is able to be slided in a direction of an arrow K. When the operator slides tilt leg 25 in the direction of the arrow K, the engaging portion of elastic portion 109 is inserted in and engaged with second groove 97 by spring 111.
FIG. 9 is an exploded perspective view of a disk assembly.
Side wall 21 of base unit 3 has a hole 117 for exposing a disk inserting portion 115 of 3.5 inches FDD 23. FDD 23 is fixed in drive housing 121 by screws 119. Drive housing 121 is fixed on inner surface 73 by screws 123. Drive housing 121 has a pair of hard disk mounting surfaces 125. A 2.5 inches hard disk drive (HDD) 127 is fixed on mounting surfaces 125 by screw 129. FDD 23 and HDD 127 is fixed on the same drive housing 121. Consequently a space of the disk assembly is compact.
FIG. 10 is a perspective view of a front top cover and FIG. 11 is a top view of a keyboard.
Front top cover 13 includes an outer frame 131 having screw engaging bosses 139 and an partition wall 137, for separating function keys 133 and character keys 135 of keyboard 11, having a pair of engaging claws 145. A plate 141 of keyboard 11 has a pair of engaging grooves 143. When keyboard 11 and front top cover 13 are assembled on base unit 3, engaging claws 145 are engaged with engaging grooves 143. Consequently, even though partition wall is thin, partition wall is prevented bending.
FIG. 12 is a perspective view of a card storing portion of the base and the card storing portion cover and FIG. 13 is a top view of an expansion card.
Bottom surface 59 of base unit 3 has an expansion card storing portion 147. Storing portion 147 is coated by an electric conducting material. One side of storing portion 147 has connectors 151 fixed on the inner surface of base unit 3. Opposite side of storing portion 147 has a card mounting wall 153 and a stopper claws 155 for preventing an expansion card slipping. Card storing portion cover 69 has a flat metal spring 157 fixed on an inner surface of cover 69. Cover 69 is an electric conductor. An expansion card 159 has a connector 163 connected to connectors 151, expansion memories 161 and an electric conducting plate 165.
FIG. 14 is a sectional view for explaining a storing condition of the expansion card.
When expansion card is stored in storing portion 147 and cover 69 is fixed on bottom surface 59 by screw 71 (FIG. 15), spring 157 is contacted to conducting plate 165 and pushes card 159 on card mounting wall 153. Inner surface 73 is coated by the electric conducting material. Consequently expansion card is electrically connected to base unit 3 through plate 165, spring 157, cover 69 and screw 71 and an electromagnetic wave is prevented.
FIG. 15 is a perspective view of a display leg and a screw cover.
Inner cover 27 includes a cover storing portion having through holes and engaging holes 169. Outer cover 29 has screw engaging portion. Inner cover 27 and outer cover 29 are engaged by screws 166. Screw cover 33 has a thick portion 177 and a thin portion 179. An inner surface 172 of thick portion 177 has a pair of supporting claws 173. An inner surface 174 of thin portion 179 has a pair of engaging claws 178 having a engaging portion 175, respectively. Inner surface 172 is contacted with cover a surface of the cover storing portion. Inner surface 174 is not contacted with the surface.
FIGS. 16A-16C are sectional views for explaining a movement of the screw cover.
When screw cover is fixed on the cover storing portion, as shown In FIG. 16A, a space K is formed between inner surface 174 and the surface of the cover storing portion. Engaging portions 175 are engaged with an inner surface of inner case 27. Supporting claws 173 are supported on the inner surface of inner case 27. When an operator pushes thin portion 179 in a direction of an arrow L, as shown in FIG. 16B, thin portion 179 is bent. When thin portion 179 is bent, engaging portions 175 is released from the inner surface of the cover storing portion. In this condition, if the operator slides cover 88 in a direction of an arrow M, cover 33 is released from Inner case 27.
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A portable electronic apparatus includes a base having a first drive mounting portion. A drive fixing member having a second mounting portion, including a raised planar surface, is mounted on the first drive mounting portion with just screws. The drive fixing member covers the first disk drive. Second screws fix the first disk drive within the drive fixing member. A second disk drive is mounted on the second drive mounting portion. A third screw fixes the second disk drive on the second drive mounting portion. A disk drive mounting space is compact because the first and the second disk drives are fixed on the same drive fixing member. Additional details relate to a handle assembly, a tilt-leg base for a keyboard, keyboard keys, two covers, and an expansion card mounting device.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle crash detection apparatus for an Inflatable occupant restraint system.
2. Description of the Related Art
A conventional crash detection apparatus for an inflatable occupant restraint system, or "airbags", makes use of an accelerometer and an offset integrator. The accelerometer generates upon crash impact a signal representative of the vehicle acceleration/deceleration, while the offset integrator subtracts the maximum acceleration value that is encountered during normal drive from the output of the accelerometer and integrates the subtracted acceleration signal over a preset time interval. The integrated signal is then compared with a threshold value and when the threshold is exceeded the restraint system Is operated. Since the airbag must be fully deployed before the occupant is tilted 12.5 centimeters forwards when the vehicle crashes at a medium speed, and the airbag deployment time is approximately 30 milliseconds, there is a small amount of time left for the crash detection apparatus to make a crash/non-crash discrimination.
While the prior art crash detection apparatus is useful for crash events where a sharp vehicle speed variation occurs upon impact, it fails to make a correct discrimination between rough roads and pole crashes where the initial impact on the vehicle is rather small.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide precision vehicle crash detection capable of making a reliable discrimination between crash and noncrash events which are currently indistinguishable.
The object of the present invention is obtained by extracting those frequency components of the output of the accelerometer which occur uniquely during a vehicle crash and using the extracted frequency components as a derision making factor.
According to a first aspect of the present invention, the output signal from an accelerometer is integrated at Intervals to derive a velocity signal. Those frequency components of the accelerometer signal which appear uniquely during the vehicle crash are extracted and the amplitude of the extracted components is squared to produce an impact energy signal. A decision is made on the velocity signal and the impact energy signal, and according to this decision, the occupant restraint system is operated. Preferably, the velocity signal is compared with a first threshold value and when it exceeds the first threshold value, the restraint system is operated. A sum of the velocity signal and the impact energy signal is produced and compared with a second threshold value, and the impact energy signal is compared with a third threshold value. The restraint system is operated when the sum exceeds the second threshold value or when the impact energy signal exceeds the third threshold value.
According to a second aspect of the present invention, the accelerometer signal at longer intervals to produce a long-term velocity signal and at shorter intervals to produce a short-term velocity signal. Frequency components of the accelerometer signal which appear uniquely during the vehicle crash are extracted and the amplitude of the extracted components is squared to produce an impact energy signal. A decision is made on the long-term and short-term velocity signals and the impact energy signal, and the occupant restraint system is operated in accordance with the decision. Preferably, the long-term velocity signal is compared with a first threshold value and when it exceeds the first threshold value, the restraint system is operated. The short-term velocity signal and the impact energy signal are compared with a second and a third threshold value, respectively. The restraint system is operated when both of the short-term velocity signal and impact energy signal simultaneously exceed their respective threshold values.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in further detail with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram of a crash detection circuit according to one embodiment of the present invention;
FIG. 2 is a block diagram of the bandpass filter of FIG. 1;
FIG. 3 is a graphic representation of the frequency response of the bandpass filter;
FIG. 4 is a crash/non-crash discrimination map associated with the embodiment of FIG. 1;
FIG. 5 is a waveform diagram showing various waveforms appearing in FIG. 1 during frontal crash, padded barrier crash and rough road drive;
FIG. 6 Is a waveform diagram showing waveforms of the accelerometer, integrator and limiter in the case of an angle crash;
FIG. 7 is block diagram of a crash detection circuit according to a modified embodiment of the present invention;
FIG. 8 is a crash/non-crash discrimination map associated with the embodiment of FIG. 7; and FIG. 9 is a waveform diagram showing various waveforms appearing In FIG. 7 during a frontal crash.
DETAILED DESCRIPTION
Referring now to FIG. 1, there is shown a crash detection circuit of the present invention mounted in a vehicle for operating an inflatable restraint system, or what is called "airbags", when the vehicle encounters a crash. The crash detection circuit includes a semiconductor accelerometer 10 which consists of a strain gauge secured on a semiconductor substrate and makes use of the piezoelectric effect of the semiconductor to produce an accelerometer signal representative of the acceleration/deceleration of the vehicle when it is mechanically deformed upon the application of an impact force.
To allow digital processing of the accelerometer signal without foldover (aliasing) distortion, an analog lowpass filter 11 is connected to the accelerometer 10 to cut off the frequency components of the accelerometer signal higher than twice the sampling frequency at which it is sampled and processed by subsequent processing circuitry. The lowpass-filtered signal is applied to a sampler 12 where it is sampled at, say, 1-ms intervals End fed into an analog-to-digital converter 13 where the sampled values are converted to a digitized signal.
The digitized accelerometer signal is applied to a sliding window integrator 14 where digital samples are stored and a predetermined number of samples In a successive window of 90 milliseconds are integrated to produce a signal representative of the instantaneous velocity of the vehicle. The integration is repeated at 90-ms intervals to update the velocity value. It is found that under certain conditions vehicle deceleration continues excessively after the instant of crash, and the accelerometer signal becomes rich with low frequency components, producing a large negative integration value. Since the excessive negative value of the integrator would cause a delay in making a crash/non-crash decision, a limiter 15 is connected to the output of integrator 14 to prevent the velocity signal from going negative below a certain critical value. The output of limiter 15 is multiplied by a coefficient K 1 in a multiplier 16 to produce a velocity parameter K 1 ฮV.
Vehicle crash can be considered as a plastic deformation of a composite of numerous resilient materials upon the application of impact. It is found that the deceleration signal contains unique frequency components when a vehicle experiences a crash. The frequency distribution of the deceleration signal that markedly shows a crash event varies depending on the type of vehicles. According to the present invention, among the various waveforms that are superimposed on a first quarter wavelength of the fundamental frequency of the sinusoidal deceleration waveform generated upon impact those frequency components having characteristic waveform fluctuations are extracted. These frequency components are considered to arise from different structural components of the vehicle as they are broken, bent and sheared upon crash impact. Typically, the characteristic frequency components are extracted from the range between 20 Hz and 200 Hz. For this purpose, the output of A/D converter 13 is applied to a bandpass filter 17 where the characteristic frequency components are extracted. The present invention evaluates the amount of a crash impact from the extracted frequency components.
As shown in detail in FIG. 2, the bandpass filter 17 includes a first adder 30 to which the output of A/D converter 13 is applied. A tapped delay fine comprising a series of one-sample delay elements, or delay-line taps 31 1 ห-31 4 is connected to the output of adder 30 to produce a succession of tap signals. Coefficient multipliers 32 1 ห32 4 are connected respectively to the outputs of delay-line taps 31 1 ห31 4 for weighting the tap signals with tap-weight coefficients a 1 , -a 2 , a 3 and -a 4 . The weighted tap signals are summed in adder 30 with the output of A/D converter 13. The output of the first adder 30 is applied recursively to the tapped delay line and to a second adder 34. A coefficient multiplier 33 is connected to the output of delay-line tap 312 to multiply the tap signal from delay unit 31 z by "--2" and applied to adder 34 to which the output of delay-line tap 31 4 is also applied. The output of adder 34 is multiplied by a coefficient "b" in a multiplier 35 for delivery to a later stage. The transfer function H(z) of the bandpass filter 17 is given by:
H(z)=b(1-z.sup.-2).sup.2 /(1-a.sub.1 z.sup.-1 +a.sub.2 z.sup.-2 -a.sub.3 z.sup.-3 +a.sub.4 z.sup.-4)
By choosing the tap-weight coefficients and the coefficient "b" as a 1 =2.2979, a 2 =1.9649, a 3 =0.8732, a 4 =0.2194, and b=0.7012, the bandpass filter 17 has a passband of 20 Hz to 200 Hz as shown in FIG. 3.
Since the vehicle speed, upon impact, decays following a cosine curve, the impact energy of the vehicle during the zero- and 90-degree phase angles of the cosine curve can be approximated as being equal to the square value of the vehicle's speed variations. For this reason, the amplitude of the frequency components extracted by the bandpass filter 17 is squared in a squaring circuit 18 to produce a signal ฮE representative of the impact energy regardless of the polarities of the deceleration signal. The impact energy signal is then weighted by a coefficient K 2 in a multiplier 19 to produce an impact parameter ฮE.
The instantaneous speed parameter ฮV and impact parameter ฮE are supplied to a deployment decision circuit 20 for supplying a deployment signal to the airbags, not shown, in accordance with decision thresholds indicated in a crash discrimination map (FIG. 4) in which vehicle velocity ฮV is plotted as a function of impact energy ฮE. In FIG. 4, different types of vehicle crash events and non-crash events are indicated in the shape of circles and ellipsis. The velocity and impact energy values falling within the boundary of any of these regions are those actually obtained by experiments at 30-ms after the instant of crash/non-crash event. A line 40 defines a first threshold R 1 and is drawn between padded barrier crashes (in which the vehicle crashes with a barrier padded with shock absorbing material) and under-carriage bumps. A line 41 defines a second threshold R 2 which is equal to the relation K 1 ฮV +K 2 ฮE drawn between frontal crash events and under-carriage bumps. Finally, a line 42 defines a third threshold R 3 that separates pole crash events and rough roads. The decision circuit 20 produces a deployment signal when either of these thresholds is exceeded. Specifically, It includes comparators 21, 22 and 23 and an adder 24. Comparator 21 compares the velocity parameter K 1 ฮV with a reference voltage representing the first threshold R 1 and produces a deployment signal when the velocity parameter exceeds the reference voltage. This occurs when the vehicle experiences a padded barrier crash. The velocity parameter K 1 ฮV and impact energy parameter K 2 ฮE are summed together by the adder 24 and compared by comparator 22 with a reference voltage representing the second threshold R 2 to produce a deployment signal when the summed value exceeds the reference in a frontal crash event. Comparator 23 makes comparison between the impact energy K 2 ฮE and a reference voltage representing the third threshold R 3 and produces a deployment signal when the reference voltage is exceeded as the vehicle experiences a pole crash.
In the case of a frontal crash at 50 kilometer per hour (FIG. 5), both acceleration (G) and velocity (ฮV) rapidly rise on impact, and the sum of impact energy and velocity exceeds the threshold value R 2 of comparator 22 within 10 milliseconds from the start of crash. In the case of a padded barrier crash at 30 kmph, the velocity (ฮV) exceeds the threshold R 1 of comparator 21 at about 80 milliseconds from the start of the crash. During a rough road drive, the velocity parameter is lower than threshold R 1 and the bandpass filter 17 produces a sharply rising output, but its amplitude is lower than threshold R 3 . With prior art techniques, false decisions are often made In discriminating a rough road event from a pole crash event. Since the decision threshold R 3 of pole crash events is set higher than any of impact energies which might be produced on rough roads, no false deployment signal is generated by the crash detector of the present invention in any rough road conditions. In the case of pole crashes, the impact energy exceeds threshold while the velocity is lower than threshold R 1 and the combined value of the velocity and the impact energy is also lower than threshold R 2 .
As illustrated In FIG. 6, the use of the limiter 15 is particularly useful for crash events where the velocity signal tends to go negative for an extended period of time and would otherwise cause decision delays. The output of limiter 15 goes positive earlier as indicated by broken lines than the output of integrator 14 does, contributing to the increases in the signal components which are significant for deployment decision.
The present invention is modified as shown in FIG. 7 which employs different decision thresholds from those used in the previous embodiment. Similar to the previous embodiment, the modified crash detection circuit comprises a 90-ms (long-term) sliding window integrator 40, a limiter 41 and a multiply-by-K 11 multiplier 42 to produce a long-term velocity signal ฮV 1 , and digital bandpass filter 445, squaring circuit 47 and multiply-by-K 2 multiplier 48 to produce an impact energy signal ฮE. Similar to the previous embodiment, long-term integrator 40 provides integration of the output of A/D converter 13 at 90-ms intervals and limiter 41 has the same lower critical value as limiter 15. The modified embodiment differs from the previous embodiment by the inclusion of a short-term sliding window integrator 43, a limiter 44 and a multiply-by-K 12 multiplier 45 to produce a velocity signal ฮV 2 . The short-term integrator 43 provides integration of the output of A/D converter 13 at 30-ms ms intervals. The lower critical value of limiter 44 is slightly higher than that of limiter 41. The velocity signals ฮV 1 , ฮV 2 and impact energy signal ฮE are supplied to a deployment decision circuit 50 which makes a deployment decision according to a decision map shown in FIG. 8.
As illustrated in FIG. 8, a line 60 defines a first threshold R 1 and is drawn between padded barrier crashes and under-carriage bumps. A horizontal line 62 corresponds to a second threshold R' 2 and is drawn between frontal crash events and rough roads. Finally, a line 61 defines a third threshold R' 3 that separates pole crash events and rough roads.
Returning to FIG. 7, the decision circuit 50 includes comparators 51, 52 and 53. Comparator 51 makes a comparison between the velocity signal ฮV 1 and a reference voltage corresponding to the first threshold R' 1 and produces a deployment signal if the latter is exceeded. The output of comparator 51 is passed through an OR gate 55 to the airbags. Comparator 52 compares the velocity signal ฮV 2 with a reference voltage corresponding to the second threshold R' 2 and produces a deployment signal if the latter Is exceeded. Comparator 53 compares the impact energy signal ฮE with a reference voltage corresponding to the third threshold R' 3 and produces a deployment signal if the latter is exceeded when a padded barrier crash occurs. The output of comparator 53 is applied to a pulse stretcher 56 where the it is stretched in duration by a monostable multivibrator 57. An OR gate 58 is connected to the outputs of both comparator 53 and monostable multivibrator 57 so that the output of OR gate 58 goes high in quick response to the output signal of the comparator 53. The outputs of comparator 52 and OR gate 58 are combined by an AND gate 54 whose output is coupled to OR gate 55. AND gate 54 thus produces a deployment signal when the short-term velocity signal ฮV 2 and the impact energy signal ฮE are time coincident with each other. Such coincidences occur when the vehicle experiences a frontal crash or a pole crash.
The waveforms of signals generated at various points of the embodiment of FIG. 7 in a frontal crash at 50 kmph are shown in FIG. 9. The output of squaring circuit 47 exceeds the threshold R' 3 within the period of 10 milliseconds from the beginning of the crash, causing comparator 53 to produce an output pulse 70, which Is stretched by pulse stretcher 56 into a pulse 71. Immediately following the leading 28 edge of the pulse 71, the output of short-term Integrator 43 exceeds the threshold R' 2 and comparator 52 produces an output pulse 72 which coincides with the pulse 71, producing a deployment pulse 73 at the output of AND gate 54.
The foregoing description shows only preferred embodiments of the present invention. Various modifications are apparent to those skilled in the art without departing from the scope of the present invention which is only limited by the appended claims. For example, the digital circuitry connected to the output of A/D converter 13 can be implemented with a digital signal processor. Therefore, the embodiments shown and described are only illustrative, not restrictive.
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In a crash detection apparatus, the output signal of an accelerometer is integrated at intervals and a velocity signal is produced. Those frequency components of the accelerometer output which appear uniquely during a vehicle crash are extracted and their amplitude is squared to produce an impact energy signal. An airbag is operated when the velocity signal exceeds a first threshold, or when a sum of the velocity and impact energy signals exceeds a second threshold, or operated when the impact energy signal exceeds a third threshold. In a modified embodiment, the accelerometer output is integrated both at longer and shorter intervals to produce a long-term and a short-term velocity signal. The airbag is operated when the long-term velocity signal exceeds a first threshold, or when the short-term velocity signal and the impact energy signal simultaneously exceed a second and a third threshold, respectively.
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CROSS-REFERENCE To RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 12/272,631 filed Nov. 17, 2008, which application claims priority to U.S. Provisional Application No. 60/988513, filed Nov. 16, 2007, the disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] The present invention relates generally to multimedia files and more specifically to the indexing of information within a multimedia file.
[0003] In recent years, the playback of multimedia files has become an integrated part of the average consumer's daily life. Cellular telephones, DVD players, personal computers, and portable media players are all examples of devices that are capable of playing a variety of multimedia files. While each device may be tailored to a particular multimedia format, the extensive proliferation of these devices encourages a certain level of interoperability amongst the different device classes and categories. Likewise, there are certain features such as fast-forward, reverse, start, stop, play, and pause which are expected to behave similarly across all device categories, despite their performance capabilities and use-case application.
[0004] One of the most common features of media playback devices is the support for random access, fast-forward and reverse playback of a multimedia file, which is sometimes referred to as โtrick playโ. Performing trick play functionality generally requires displaying the video presentation at a higher speed in forward and reverse direction, and resuming the overall presentation from a position close to where the viewer terminated the video trick play activity. The audio, subtitle, and other elements of the presentation are typically not used during trick play operations, even though that can be subject to a device's operating preference. In accommodating trick play functionality, multimedia files typically contain an index section used to determine the location of all frames, and specifically the video frames which can be independently decoded and presented to the viewer. When all index information is stored in a single location within a file and linearly references the multimedia information within the file, a player must seek to a specific index entry in order to be able to play a file. For example, a player that is instructed to play a multimedia presentation at the half-way point of the presentation typically processes the first half of the index data before being able to determine the set of data points required to commence playing.
[0005] The index section has many other potential applications as well: it may be a necessary element in basic playback of multimedia files that exhibit poor multiplexing characteristics; the index section may also be used to skip over non-essential information in the file; also, an index is often required for the resumption of playback after the termination of trick play functions.
SUMMARY
[0006] Embodiments of the invention utilize indexes that can increase the efficiency with which a player can perform a variety of functions including trick play functions. In several embodiments, the index is a hierarchical index. In many embodiments, the index is a reduced index and, in a number of embodiments, the index is expressed using bit field flags and associated data fields.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a graphical representation of an index structure within a multimedia file in accordance with an embodiment of the invention.
[0008] FIG. 2A is a graphical representation of an index structure following the audio/video data of a multimedia file in accordance with an embodiment of the invention.
[0009] FIG. 2B is a graphical representation of an index structure interleaved within the audio/video data of a multimedia file in accordance with another embodiment of the invention.
[0010] FIG. 2C is a detailed graphical representation of an index structure relative to other portions of a multimedia file in accordance with an embodiment of the invention.
[0011] FIG. 2D is a graphical representation of an index structure relative to cue data of a multimedia file in accordance with an embodiment of the invention.
[0012] FIG. 3 is a graphical representation of index structure detailing bit flags and associated data filed within a multimedia file in accordance with an embodiment of the invention.
[0013] FIG. 4 is a graphical representation of index structure providing time codes and offset data fields within a multimedia file in accordance with an embodiment of the invention.
[0014] FIG. 5 is a graphical representation of index structure with time codes and multiple offset data fields relative to a size data field within a multimedia file in accordance with an embodiment of the invention.
[0015] FIG. 6 is a graphical representation of index structure with time codes and primary offset data fields within a multimedia file in accordance with an embodiment of the invention.
[0016] FIG. 7 is a semi-schematic network diagram of playback system for streaming and fixed media file playback in accordance with an embodiment of the invention.
[0017] FIG. 8 is a flowchart of a process utilizing index structure within a multimedia file in accordance with an embodiment of the invention.
[0018] FIG. 9-11 are graphical representations with increasing detail of an index structure within a multimedia file in accordance with one embodiment of the invention and to further illustrate the process of FIG. 8 .
DETAILED DESCRIPTION
[0019] Turning now to the drawings, multimedia files including indexes in accordance with embodiments of the invention are described. In a number of embodiments, the index is a hierarchical index. A hierarchical index is a representation of index information in a form that provides a coarse index to a few predetermined locations within the multimedia file followed by a further refined representation of the portions of the multimedia file. In many embodiments, the lowest level of the index is sufficiently granular as to identify every frame in the multimedia file. When a hierarchical index is used, a player need only request a small amount of relevant index information in order to commence playing a multimedia file. As such, the hierarchical index lowers the memory footprint needed by playback devices to effectively seek and perform trick-play operations on a multimedia file. Additionally, file load times for playback are reduced and trick-track load performance enhanced. In one embodiment, the hierarchical index has index information that includes offsets into cue points within a multimedia file with timestamps allows lookups to be fast and efficient.
[0020] In several embodiments, the multimedia file includes a reduced index. Players in accordance with embodiments of the invention can utilize a reduced index to rapidly move between accesses or key-frames when performing trick play functions. The reduced index can be in conjunction with a hierarchical index. However, reduced indexes can be included in multimedia files that do not include a hierarchical index. A reduced index only provides the location of the accesses or key-frames within a multimedia file, along with a time-stamp value to indicate their corresponding time within the multimedia presentation. In a number of embodiments, bit field flags and associated data fields are used to represent index information. Such a representation can be used in accordance with embodiments of the invention to express index information, a hierarchical index and/or a reduced index.
Hierarchical Indexes
[0021] A multimedia file containing a hierarchical index in accordance with an embodiment of the invention is shown in FIG. 1 . The multimedia file 10 includes header information 12 , index information 14 interleaved amongst audio/video data 16 and a three layer hierarchical index. The coarsest layer 18 of the hierarchical index includes a small number of references to pieces of index information. The middle layer 20 and the finest layer 22 each include successively larger numbers of references to index information.
[0022] In many embodiments, the index information 14 interleaved amongst the audio/video data 16 lists the location of encapsulated audio, video, subtitle, and/or other similar data. Typically, each block of interleaved index information lists the encapsulated media immediately following the block of interleaved index information. In several embodiments, the index information 14 contains information that describes the absolute or relative location of the start of each piece of encapsulated media. In a number of embodiments, the interleaved index information 14 includes the size of each indexed piece of encapsulated media, in addition to information indicating whether the indexed piece of encapsulated media can be used as an access or key-frame, its presentation time value, and other information, which may be helpful to a decoding device.
[0023] Each layer in the hierarchical index includes references to the interleaved index information 14 within the multimedia file 10 . The implementation of the hierarchy structure can be inclusive or exclusive, meaning that the data in each layer can be repeated in the other layers or each layer may contain unique position information. In addition, the number of elements at each layer of a hierarchy and the total number of layers can be pre-determined, limited based on pre-determined values, or unbounded.
[0024] Although a specific implementation of a hierarchical index is shown in FIG. 1 , hierarchical indexes can be implemented in many different ways. For example, the index values can be stored in a single part of the file, or distributed in clusters in the file. Multimedia files containing different distributions of index information in accordance with embodiments of the invention are shown in FIGS. 2A-B . For example, the index information could be appended or pre-pended to the audio/video data portion 16 of the multimedia file 10 as an entire unit 21 . Index clusters 22 shown in FIG. 2B can also be woven into the audio/video data portion. In addition to distributing index information in different ways, the hierarchy itself can be implemented as a structure that points to the actual frames in a file (as opposed to blocks of index information), which may or may not start with access or key-frame positions.
[0025] FIG. 2C further details the hierarchical index 21 within a larger hypothetical file structure MKV file 200 . This file structure is made of two primary sections, the EBML 24 and the Segment 26 . In this file structure, the Segment may host the Seek Head 201 , Segment Info 202 , Tracks 203 , Chapters 204 , Cluster 205 , Cues 29 , and a Hierarchical Index 21 . As shown, a plurality of hierarchical indexes 21 could be included with the multimedia file. Additionally, each hierarchical index can include multiple hierarchical index points 23 . These index points in various embodiments have a timestamp 25 and a track position 27 , specifying a specific media track 27 a and a position or offset 27 b from the timestamp 25 . Cues 29 are also shown and as will be explained in more detail below are utilized by the index points 23 to increase access to specific points within a multimedia file. This dynamic structure for example is shown in FIG. 2D where multiple hierarchical index points 23 reference or point to multiple cue points 28 . In various embodiments, the hierarchical index contains references to a fraction, e.g., one tenth, of cue points relative to the total number of cue points in a media file. One would appreciate that the references can increase to increase the granularity of pointers or references to the cue points.
[0026] A player attempting to decode a multimedia file that includes a hierarchical index in accordance with an embodiment of the invention typically uses the hierarchical index as necessitated by the functions the player is requested to perform. When trick play functions are requested, the player can locate an index in the hierarchy corresponding to a specific speed and decode each of the frames indicated by the index. The manner in which a specific frame is located using the index depends upon the nature of the index. In embodiments where each index in the hierarchy points directly to video frames, then the process is simple. In embodiments where the index points to additional index information within the multimedia file, the additional index information is accessed and used to locate a desired frame.
Reduced Indexes
[0027] Many multimedia files in accordance with embodiments of the invention use reduced index information. Reduced indexes can be used in conjunction with a hierarchical index or in multimedia files that do not include a hierarchical index. A reduced index does not include information concerning every piece of multimedia information within a multimedia file. A reduced index typically is restricted to information concerning the location of access or key-frames and the time stamp of the access or key-frames. Access frames are generally video frames that can be independently decoded, although the reduced index can be used to point to any other type of key-frame for other streams stored in the multimedia file. The reduced index can enable a player to rapidly skip between key frames when performing trick play functions.
[0028] In a number of embodiments, a reduced index is only provided for a single or primary data type and offsets are provided for each of the other streams of data contained within the file which may be related to the primary data type. The offsets can be used by a player to facilitate synchronized playback of different media. In several embodiments, each piece of index information also includes the size of the access or key-frame and the data-type of the access or key-frame. A player decoding a multimedia file that contains a reduced index in accordance with an embodiment of the invention can use the reduced index to perform trick play functions in a similar fashion to the way in which a player uses a hierarchical index. The player can sequence through the reduced index inspecting the Timestamps of access or key frames to ascertain which frames to render in order to achieve a desired speed.
Expressing Index Information Using Bit Fields
[0029] Multimedia files in accordance with a number of embodiments of the invention utilize bit field flags and associated data fields to express index information. In many embodiments, the bit field flags are used to signal the presence of a set of corresponding variable length data fields that contain index information. Bit field flags 31 and data fields 32 that can be used to express index information concerning a piece of multimedia information in accordance with an embodiment of the invention are shown in FIG. 3 . In the illustrated embodiment, a set of bit-field flags signals the presence of additional data following the flags. The bit-field flags are specified as 8-bits in their entirety, but that is not necessarily a requirement for other implementations. The first bit of the flag may indicate an Absolute/Fixed Size field 31 a, which determines whether the size of the frame is read from a pre-determined set of sizes stored in a separate section of the file, or whether they are available as a series of bytes following the flags field. Two additional bits, Fixed Size Index/Byte Numbers field 31 b, are used to determine the index-position of the size value or the total number of bytes used to represent the value, depending on the setting of the Absolute/Fixed Size bit or field 31 a. The next bit, a Primary Offset field 31 c, determines the size of the offset value, which may be the location of the frame. This bit is selected amongst two pre-determined byte numbers, for example either a 4-byte value or 8-byte value. Likewise, a flag may indicate the presence of another predetermined offset, e.g., a Secondary Offset 33 , which can be 4 bytes and represents a relative offset from the Primary Offset value. A bit 31 e indicating the presence of a timecode byte sequence may also be present, along with another bit, Key Frame Flag bit 31 f, which can be used to determine the presence of access or key frames. In many embodiments, bit field flags and data fields similar to those shown in FIG. 3 are used to index the location of all frames in a multimedia file.
[0030] The number of flags that can be represented via the structure shown in FIG. 3 is infinitely extensible using a โFlags Extensionโ bit 31 g which signals the presence of a follow-on flag. Here, one bit 31 h may be referred to as โAssociated Offsetsโ. Associated offsets may then signal the presence of a byte value, which is used to determine the number of streams which correspond to the current frame. These relative offsets may use the same flag and subsequent index information for other frames in the stream, to be used for synchronization purposes. The frames identified by the relative offsets, when played back correctly, may provide a synchronized presentation of audio, video, subtitles, and other related data. The stream number value 32 often corresponds to the actual stream numbers stored in the file.
[0031] Index information represented using the two relative offset values 41 a,b is shown in FIG. 4 . In many embodiments, the data type for each frame is indicated for an entire group of frames, or alternatively is indicated on a frame-by-frame basis, in which case a โData Typeโ field 35 is added to the index-structure. The presence of a Timecode value 37 to indicate the exact time of a frame in an overall presentation may be done via a set of pre-determined specifications. For example, the Timecode value could be required for all video access frames; alternatively, the presence of a Timecode could be mandatory on a periodic basis for audio samples. It is only important to note that the Timecode value is optionally present and is indicated by a corresponding bit-flag.
[0032] Through a set of pre-determined rules, structures similar to those described above can be applied for the representation of hierarchical indexing in accordance with embodiments of the invention. For example, the โPrimary Offsetโ value 50 can point to a specific index position, along with the Timecode value 52 indicating the exact time-stamp of the index. An additional bit-field 39 , the โSubindexโ, can point to a relative offset from the position indicated by the โPrimary Offsetโ. This โSubindexโ position 54 is a refinement from the beginning of a larger index cluster. Use of various values to construct a hierarchical index in accordance with an embodiment of the invention is shown in FIG. 5 .
[0033] Bit field flags and associated data fields can also be used to represent a reduced index structure pointing to a series of access or key frames for a particular stream in a file. A reduced index in accordance with an embodiment of the invention is shown in FIG. 6 . In the illustrated embodiment, the โflagsโ field 602 is followed by a corresponding set of size bytes 604 , a โPrimary Offsetโ value 606 , and a Timecode 608 . The access frames may typically be related to video frames in a file, though again this field could be defined for all stream types in a file. The structure 600 shown in FIG. 6 stores the location of all access or key-frames, and can contain the location of all related offsets for the encapsulated tracks in the file.
[0034] It is important to note that the use of flexible bit field flags enables the implementation of multiple data structures which may appear in the hierarchical, reduced, and conventional indexing schemes. The use of bit fields as flags indicating variable length data can help optimize the size of an overall index because not all members are in general required by all frames.
[0035] Referring now to FIG. 7 , a progressive playback system in accordance with an embodiment of the invention is shown. The playback system 190 includes a media server 192 connected to a network 194 . Media files are stored on the media server 194 and can be accessed by devices configured with a client application. In the illustrated embodiment, devices that access media files on the media server include a personal computer 196 , a consumer electronics device such as a set top box 18 connected to a playback device such as a television 200 , and a portable device such as a personal digital assistant 202 or a mobile phone handset. The devices and the media server 192 can communicate over a network 194 that is connected to the Internet 204 via a gateway 206 . In other embodiments, the media server 192 and the devices communicate over the Internet.
[0036] The devices are configured with client applications that can request portions of media files from the media server 192 for playing. The client application can be implemented in software, in firmware, in hardware or in a combination of the above. In many embodiments, the device plays media from downloaded media files. In several embodiments, the device provides one or more outputs that enable another device to play the media. When the media file includes an index, a device configured with a client application in accordance with an embodiment of the invention can use the index to determine the location of various portions of the media. Therefore, the index can be used to provide a user with โtrick playโ functions. When a user provides a โtrick playโ instruction, the device uses the index to determine the portion or portions of the media file that are required in order to execute the โtrick playโ function and requests those portions from the server. In a number of embodiments, the client application requests portions of the media file using a transport protocol that allows for downloading of specific byte ranges within the media file. One such protocol is the HTTP 1.1 protocol published by The Internet Society or BitTorrent available from www.bittorrent.org. In other embodiments, other protocols and/or mechanisms can be used to obtain specific portions of the media file from the media server.
[0037] Referring to FIGS. 8-11 , one embodiment of a process of utilizing the index structure is shown. A media file, e.g., MFile 120 , is received from, for example, a media server based on a media file request from a playback device or in particular a playback engine of the playback device ( 111 ). Upon locating the requested media file, the media server transmits all or some portions at a time of the media file to the playback device. The playback device in one embodiment decodes the transmitted media file to locate the hierarchical index ( 112 ). In one such embodiment, referring to FIG. 9 , the playback device traverses or parses the file starting from EBML (Extensible Binary Meta Language) element 128 , the Segment element 129 and then the contents of the Seek Head 121 to locate the Hierarchical Index 127 . As such, the Segment information 122 , Tracks 123 , Chapters 124 , Clusters 125 and Cues 126 , although could be also parsed, can be bypassed to quickly locate the Hierarchical Index. The located Index is then loaded into memory ( 113 ). Loading the Index into memory facilitates access to locate a desired packet or frame to be displayed or accessed by the playback device.
[0038] The Hierarchical Index is small enough for many low memory playback devices, e.g., low level consumer electronic devices, to hold the entire Index in memory and thus avoiding a complex caching scheme. In cases, where the Index is too large to store in memory or generally more feasible, no loss in seek accuracy occurs. With the Index being a lookup table or mechanism into the cues or defined seek points for each of the tracks and not the actual seek points, the dropping of portions of the Index can cause a few additional reads when searching the cues for a desired seek point. The playback device accesses the bit stream packets or frames of the transmitted media file to play the audio, video, and/or subtitles of the media file ( 114 ).
[0039] Upon a user request, e.g., a trick-play request, the playback device searches the loaded or cached Hierarchical Index to find an entry or hierarchical point equal to or nearest and preceding to the desired time or seek point ( 115 ). In one embodiment, the particular hierarchical point is located based on the presentation time or timestamp of the content being played and the user request, e.g., the speed and/or direction of trick-play function. In the illustrated case, FIGS. 10-11 , the desired timestamp is 610 seconds within the bit stream.
[0040] FIG. 10 demonstrates a total of 6 hierarchical access points 130 , starting from Index Time zero (Hierarchical Index Time 131 ) to Index Time 600 (Hierarchical Index Time 132 ), where five of the Hierarchical Points on this diagram have not been shown. After locating the closest hierarchical point to the desired seek time (in this case Index Time 600 ), an Index Position or offset 134 is retrieved from Track Position 133 to locate a portion of cues that contains the desired seek point ( 116 ). The playback device seeks to the located portions of cues ( 117 ) and the cues are read through until an entry equal to, or nearest and preceding to the desired time or seek point is located ( 118 ).
[0041] Utilizing the located cue, the playback device retrieves an offset value to seek and find the desired cluster ( 119 ). A block in the desired cluster that has a corresponding timestamp as the desired timestamp, e.g., 610 , is located and decoded ( 120 ) for display by the playback device. The process continues until a user request stops playback of the media file.
[0042] This concept is further clarified in FIG. 11 . The Hierarchical Index time of 600 is identified from the Hierarchical Index structure 127 as previously described in reference to FIG. 10 . In this particular example, the Index position within the Cues structure 151 is used to access the particular Cue Point 152 which corresponds to time 610 (Cue Time 153 ). The Cue Point 152 through data in Track Position 154 and Cluster Position 155 generally points to the Cluster structure 160 which may host several seconds' worth of multimedia data.
[0043] The multimedia data within a Cluster 160 may be stored as a Block Group 163 , where individual Blocks of data corresponding to one or more access units of the elementary audio, video, subtitle, or other multimedia information exist. As such, Clusters contain block groups but can also contain only simple blocks. In the absence of a Block Group, it may be possible that a Cluster can host individual Blocks or a Simple Block. The corresponding Cluster Position 155 from the Cue Point 152 is used to locate the Cluster 160 and the desired Block 161 can be identified based on its time stamp (Block Time 162 ). In case where an exact time stamp is not matched, the Block with the closest time stamp can be identified.
[0044] The procedure for locating a Block according to a particular time may be repeated for multiple tracks of multimedia data such that all of the data in the corresponding Blocks are presented in a synchronized manner.
[0045] While the above description contains many specific embodiments of the invention, these should not be construed as limitations on the scope of the invention, but rather as an example of one embodiment thereof. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their equivalents.
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Playback and distribution systems and methods for multimedia files are provided. The multimedia files are encoded with indexes associated with the content data of the multimedia files. Through the use of the indexes, playback of the content is enhanced without significantly increasing the file size of the multimedia file.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to document storage devices, and more specifically, to readily transportable protecting casings for storing and transporting oversized printed materials in a rolled up configuration.
[0003] 2. Description of the Prior Art
[0004] It is often necessary to transport blueprints of many different sizes, oversized engineering drawings, architectural drawings, canvases and other relatively large materials from place to place such as for reference at a job site. Since it preferable to transport the drawings in a rolled up configuration as opposed to folding which might introduce creases, often the drawings are simply rolled up and held in a tightly rolled configuration with a rubber band. The rolled up package is then hand carried to the job site. In the absence of a protective casing, the drawings may degrade due to exposure to environmental hazards or from undesirable impacts. Such degradation often occurs in the form of distorted figures or markings and/or torn edges rendering the drawings unreadable or unusable thus requiring additional drawings to be generated.
[0005] An early proposal for a case used to transport an oversized map is described in U.S. Pat. No. 2,293,979 to Hopkins. Such case is constructed of a flexible outer covering formed by two sheets of transparent material for sandwiching a map therebetween. The case includes several reinforcement strips attached around its borders and adapted to, in an unrolled condition hold the map in a rigid, flat configuration for viewing. The strips may be removed and placed along one edge and the casing rolled up with the map on the inside offering some protection for the map.
[0006] Another proposal is the carrier tube found in U.S. Pat. No. 4,467,917 to Hayashi. Such tube includes a liner having two pouches comprised of a flexible material for providing a backing for a print or document. The print is placed within the pouches of the liner which is then wound around a mandrel to wind the print into a cylindrical shape. A clip may be slid over the end of the mandrel to hold the liner in place. The mandrel with rolled up liner is then inserted into a hollow rigid carrying tube. Ends caps are placed over the ends of the mandrel and a cap is also placed over the open end of the tube to protect the contents therein. There are several drawbacks to this construction. Incorporation of the mandrel limits the number of documents that may be placed therein and adds to the overall weight of the tube. The tube itself is rigid thus occupying considerable space, even when not in use.
[0007] Yet another container is illustrated and described in U.S. Pat. No. 4,505,424 to Chappars. The Chappars containers includes at least two layers of flexible material forming a pocket for containing relatively flat articles such as newspapers in either a flattened or rolled up configuration. Three rows of spaced apart strips of hook and loop material are disposed on the outer surface of the layers enabling the formation of an open ended tube of two different diameters for accommodating newspapers of two different sizes when the layers are rolled up into a cylinder.
[0008] U.S. Pat. No. 4,530,175 to Wellman discloses another example of a portable document storage device. The Wellman device includes a number of watertight envelopes secured on one end from a backing member. Documents are placed within the envelopes and the entire backing member can be rolled up into a tightly rolled open ended cylindrical configuration.
[0009] A review of these package carriers reveals that it is apparent that selection of multiple containers is often required to transport materials rolled up into different sized packages. This is burdensome as multiple containers must be carried from one site to another and the contents must be labeled to avoid being separated. Additionally, the containers are often sized much larger than their intended contents and thus the contents are free to move within the carrier and incur damage and unravel from their rolled up configuration.
[0010] What is needed and heretofore unavailable is a lightweight, transportable carrier for storing, transporting, and protecting rolled up articles of first and second configurations thereby removing the necessity of transporting multiple containers.
SUMMARY OF THE INVENTION
[0011] In accordance with a preferred embodiment of the present invention, a lightweight, portable bag storage apparatus for storing rolled up sheets of material is provided and includes an elongated tubular bag body having a major part of non-distensible material and having a first cross section for receiving smaller rolled up tubes of material and an expanded cross section for receiving larger rolled up tubes of material. The bag body further includes a longitudinal expansion strip formed of a stretchable material forming an expansion zone which is expandable enabling the bag body to stretch from the first cross section to assume the enlarged second cross section. A longitudinal opening closable by a fastener device is openable for selective insertion of the tubes into the bag body.
[0012] In another feature of the present invention, pockets and carrying straps are attached to the bag body to facilitate additional storage capacity and transportability.
[0013] Yet another feature of the present invention is the incorporation of a plurality of expansion strips wherein the non-distensible part comprises about 80-90% of the transverse circumference of the bag body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a perspective view of a portable bag storage apparatus embodying the present invention in an expanded configuration;
[0015] [0015]FIG. 2 is a perspective view of the bag apparatus depicted in FIG. 1 in a contracted configuration;
[0016] [0016]FIG. 3 is a perspective view of the bag apparatus shown in FIG. 1 in an open configuration;
[0017] [0017]FIG. 4 is a back perspective view of the bag apparatus shown in FIG. 1;
[0018] [0018]FIG. 5 is a top view of the bag apparatus shown in FIG. 1 in a semi-folded configuration;
[0019] [0019]FIG. 6 is a top plan view of the bag apparatus shown in FIG. 1 in a folded configuration;
[0020] [0020]FIG. 7 is a transverse cross sectional view taken along lines 7 - 7 of FIG. 1; and
[0021] [0021]FIG. 8 is a transverse cross sectional view taken along lines 8 - 8 of FIG. 2.
[0022] Numerous advantages and aspects of the invention will be apparent to those skilled in the art upon consideration of the following detailed description taken in conjunction with the drawings which generally provide illustrations of the invention in its presently preferred embodiments.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Referring now to FIGS. 1 - 4 , a transportable storage apparatus, generally designated 10 , is provided for storing and transporting one or more oversized materials within a protective covering. The portable bag storage apparatus 20 is typically provided for storing, transporting, and protecting a sheet, such as an engineering drawing or blueprint, while in a rolled up configuration, generally designated 21 . In practice multiple sheets may be rolled up into one or more drawing packages and placed inside the bag and transported between a drafting site and a job site or other location. Advantageously, the bag apparatus is formed of flexible materials such that the bag may be folded up and stored in a reduced profile configuration when not in use.
[0024] In general terms, the bag storage apparatus 20 includes a non-distensible first section 22 comprising the majority of the circumference of the bag and an expansible second section 24 cooperating together to form an elongated, tubular bag body 26 generally divisible into an insertion region 23 , a central region 25 , and a closed region 27 . At the outermost portion of the insertion region is an openable end 28 for inserting a drawing package 21 into the bag body 26 . At the opposite end of the bag body 26 in the closed region is a closed end 30 forming the bottom extent of the bag body 26 . As further illustrated in FIGS. 7 and 8, the tubular bag body 26 is constructed to provide a contracted cross sectional area, generally designated 38 , for storing drawing packages 21 up to a predetermined size and further constructed to assume an expanded cross sectional area, generally designated 40 , for storing drawing packages 21 relatively greater in size than the predetermined size. To assume the enlarged cross sectional area 40 , the bag body 26 incorporates expansion strips 42 formed in the second section 24 and projecting longitudinally through all three regions 23 , 25 , and 27 . Such expansion strips are constructed to increase in width and also stretch outwardly in a radial direction. An opening 44 defined between confronting edges 46 within the insertion region 23 projects longitudinally through the major section 22 and further projects around the openable end 28 . The edges 46 are secured together with a fastener device 48 which draws the opposing edges together and seals the bag contents within the bag body 26 .
[0025] The bag body 26 is formed by sewing or otherwise joining a first panel 50 to a second panel 52 along longitudinal seams. Both panels include a non-distensible material such as canvas sewn on one edge to a longitudinal expansion strip 42 made of stretchable fabric such as a stretchable nylon material or other suitable material. The first and second panels 50 and 52 are arranged so that the expansion strips 42 are positioned between the longitudinal edges of the canvas sections and then sewn together to create a generally tubular shaped sleeve with opposing ends 28 and 30 . Thus, the non-distensible material and expansion strips are formed in a circumferentially alternating arrangement. The canvas and stretchable materials used in the panels are flexible enabling a user to fold the bag 20 when not in use.
[0026] While the bag 20 is primarily designed for the storage and transportation of rolled up materials and thus is preferably constructed to form a cylindrical cross section, other suitable cross sections will be apparent to those of ordinary skill. When in unstretched condition, the expansion strips 42 may be slightly recessed or pressed inwardly from the outer surface of the canvas sections to further protect them from normal wear and tear when not in use. The canvas sections are selected to handle a relatively larger degree of wear and tear and may be provided in a variety of color schemes.
[0027] The outermost extent in the closed region 27 of the bag sleeve is sewn closed forming the closed end 30 while the opposing end 28 of the bag in the insertion region 23 remains open. A slit is introduced starting at periphery of the open end 28 within one of the canvas sections and cut about one-third of the way down the length of the sleeve on one side and about one-quarter of the way on the opposing side cooperating with the open end of the bag body 26 to create the opposing edges 46 with openable flaps 56 within the insertion region 23 . The open end 28 is pinched together and the fastener device 48 is sewn into the opposing edges 46 .
[0028] The fastener device 48 is preferably in the form of a zipper with a set of complementary teeth lining the opposing edges such that the zipper handle 58 may be pulled in one direction so that the flaps 56 (FIG. 3) may be opened for insertion of the sheet package. Pulling the zipper handle in the opposite direction secures the flaps to one another to seal the bag body and protect the contents therein. The zipper is preferably plastic but may be formed of any suitable material such as metal. Other fasteners including hook and pile panels sold under the trademark Velcroยฎ and other suitable fasteners will occur to one of ordinary skill. Advantageously, the longitudinal opening projects onto one end 28 of the bag body 26 in to accommodate those infrequently encountered situations where the length of the drawings in a rolled up configuration exceeds the length of the bag.
[0029] After the panels 50 and 52 are joined together and the ends 28 and 30 are formed, the bag body 26 is preferably 30-36 inches in length and forms a first cross section 38 preferably circular and measuring approximately five inches in diameter when in an unexpanded state (FIGS. 2 and 8). The expansion strips 42 measure approximately two inches in width and project from one end of the bag to the other. The expansion strips are selected to stretch in a radial direction to allow the bag to assume an expanded configuration with a six and one-half inch diameter when in the fully expanded condition 40 (FIGS. 1 and 7). In other words, the overall circumference can stretched about 30 percent. The canvas sections 22 are relatively non-distensible. It will be appreciated that the selection of an expansion strip with a relatively large stretch percentage may be slimmer in width and achieve the same results as a wider expansion strip with a lesser stretch percentage.
[0030] The preferred ratio of canvas material to stretchable nylon material as a percentage of the total diameter of the bag in a relaxed position or unexpanded state is about 8 or 9 to 1. In other words, about 80-90 percent of the circumference of an unstretched bag body 26 is canvas material.
[0031] In the preferred embodiment, two longitudinal expansion strips 42 allowing expansion of the bag in a radial direction are described. However, it will be appreciated that one longitudinal expansion strip may be used and that circumferential expansion bands (not shown) may also be incorporated into the bag to allow expansion in the longitudinal direction as well.
[0032] Transportation of the bag is advantageously facilitated by an elongated handle 60 sewn into the exterior surface of the bag body 26 within the central region 25 and an elongated carrying strap 62 having anchor points 63 sewn in the insertion region 23 and the closed region 27 respectively. Both the carrying strap and handle are preferably made of nylon. The handle 60 is sewn into canvas of the major section 22 of the bag body 26 on either side of its longitudinal midpoint so that, when grasped, the bag body may be balanced in a comfortable manner. The carrying strap 62 is removably attached to the bag body and also straddles the longitudinal midpoint of the bag body 26 . The strap includes a catch 64 at both free ends which are releasably attachable to rings 66 sewn into the bag body on the canvas portion. The strap is preferably adjustable using a sliding buckle 67 and is well known to one of ordinary skill. As the carrying strap 62 is removable, it may be stored inside the bag 20 when not in use.
[0033] Also located on the exterior surface of the bag body 26 within the closed region 27 is a pocket 70 having a closed bottom end 72 and an openable top end 74 with a securing flap 76 including a fastener preferably made from Velcroยฎ with one portion of the hook and loop type fastener located on the outer pocket surface and the other portion of the hook loop type fastener on the inside of the flap 76 such that the pocket remains closed when the flap fastener overlies and abuts the complementary pocket fastener. The pocket is formed with side gussets 78 allowing for the pocket to expand to provide a larger internal compartment for storing pens, pencils, pads of paper, tape measures, and the like. The pocket 70 is formed of the same flexible but durable material comprising the major section of the bag body. When not in use the pocket is constructed to lay flat against the bag body to facilitate folding of the bag into a low profile package.
[0034] Advantageously, the bag body 26 is flexible and may be stored in a folded condition (FIG. 6). In its folded state, the length of the bag may be reduced by about two-thirds of its unfolded length (FIG. 2). Securing the bag in a folded state is an exterior fastener 80 preferably in the form of a snap fastener having complementary mating sections positioned centrally near the open end of the bag and also positioned near the longitudinal midpoint of the bag. The complementary mating sections are aligned such that when one third of the bag is folded over as illustrated in FIG. 5, the snap fastener snaps together and secures the folded insertion region 23 to the central region 25 of the bag body 26 .
[0035] An interior fastener 82 also includes complementary mating portions positioned near the intermeshing teeth of the zipper fastener and also near the closed end 30 of the bag body 26 (FIG. 5 ). The one-third folded bag body may again be folded in half to align the complementary fastener portions and snap them together to secure the bag body in a tri-folded position (FIG. 6). The snap fasteners 80 and 82 are selected to allow a carrier to snap and unsnap the fasteners with a relatively minimal amount of effort. In its final tri-folded position, the pocket 70 is exposed allowing the user easy access to any contents therein. With all its components, the empty bag 20 remains lightweight and only weighs about 8 ounces empty and is preferably waterproof for protecting any contents inserted therein.
[0036] In operation, assuming the bag is an unused tri-folded position as illustrated in FIG. 6, the user would initially unfold the bag into an elongated body by grasping the exposed free end 30 of the bag and pulling it until the snap fastener 82 disengages and assumes the position illustrated in FIG. 5. The user grasps the opposing open end 28 and pulls the end with sufficient force away from the central portion of the bag until the interior snap fastener 80 disengages and the bag may be unfolded into its fully elongated position as illustrated in FIG. 2. To open the bag in preparation for the insertion of one or more sheets of material, the user grasps the zipper handle 5 8 and pulls it along the zipper length to separate the confronting edges 46 along the longitudinal section of the zipper 48 and over the openable end 28 of the bag.
[0037] The drawings or sheets of material are rolled up into a cylindrical configuration and maintained using a rubber band or other suitable fastener for maintaining the sheets in a rolled up configuration forming a drawing package. The flaps 56 are separated in preparation for insertion of the drawing package into the bag 20 . One end of the rolled up drawing package 21 is then inserted into the open end 28 of the bag body 26 and pushed along the length of the bag body until its distal end is positioned against the closed end 30 of the bag. The user then grasps the zipper handle 58 and draws it along its length around the open end 28 and then along the longitudinal section until the zipper abuts the terminus of the zipper. Closing the zipper seals the sheets 21 within the bag body 26 and prevents environmental hazards from damaging the bag contents during transportation. Upon reaching the desired destination, the carrier grasps the bag 26 by its central region or lays the bag on a flat surface and then grasps the zipper handle 58 with a free hand and draws the zipper handle along the zipper teeth to separate the opposing edges 46 and flaps 56 creating an opening in the bag. The closest end of the drawings to the open end of the bag is grasped and the entire drawing package is withdrawn from the bag.
[0038] While the bag body 26 is dimensioned to accommodate a wide variety of drawing lengths and diameters, in certain situations it is desirable to store and transport a larger sheet package 21 . In such cases, the present bag storage apparatus allows for the additional diametrical size requirements. In addition, at times instead of one rolled up sheet package several packages may need to be transported to a job site. To accommodate these occasions, the expansion strips 42 enable the bag to stretch in a radially outward direction to assume an enlarged diameter to receive the larger package size or additional packages. For example, the initial package 21 is rolled up into a cylindrical package having no more than a five inch diameter. Once the carrier is at the job site, additional drawings are added to the initial package creating a second rolled up package of greater than five inches in diameter but not greater than six and on-half inches in diameter. Due to the stretchability of the expansion strips 42 , the bag body 26 may assume an expanded larger cross section 40 configuration to enclosed the larger size drawing package. In practice, after opening the bag as described above, one end of the larger drawing package would be inserted into the open end of the bag 20 . As the ends of the drawing package encounters the interior of the bag body 26 its increased diameter forces both of the expansion strips 42 to stretch radially outwardly in equal amounts to provide a bag body having an enlarged cross sectional area 40 to accommodate the larger size package (FIGS. 1 and 7). In its stretched state, the bag body will encircle and be tautly drawn across the outer surface of the drawing package to maintain the drawing package's cylindrical shape.
[0039] If desired, the rolled up sheets 21 may be inserted into the bag without an encircling fastener and maintained in a loosely rolled up configuration by the sidewalls of the bag body 26 . This facilitates unrolling the drawings and preventing damage from unrolling a rubber band from the sheet package which on occasion may tear the drawings. In addition, providing the opening across the openable end 30 of the bag 20 allows a carrier to accommodate drawings having a length longer than the length of the bag. In other words, if the drawing package 21 is too long for the selected bag 20 , one end may remain protruding from the openable bag end. Thus, a carrier can protect most of the drawing package 21 until the carrier is able to procure a longer bag 20 .
[0040] While the dimensions recited herein have been found to accommodate a large variety o drawings sheets encountered in the construction, engineering, and architectural, electronic, and software industries, these dimensions are not meant to be limiting and it will be appreciated that one of ordinary skill may incorporate a different set of dimensions and materials suitable for storing and transporting other materials without detracting from the spirit and scope of the invention.
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A portable bag storage apparatus including an elongated bag body constructed with a non-distensible major part and having a first cross section for receiving rolled up articles of a first size and incorporating an expansion strip formed of stretchable material to provide for stretching the bag body from the first cross section to a second cross section for accommodating larger sized rolled up articles. The bag further includes an opening and a fastener device enabling selective insertion of the rolled up articles into the bag body.
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BACKGROUND
[0001] The use of satellite-based and aerial-based imagery is popular among government and commercial entities. One of the challenges in obtaining high quality images of the earth is the presence of the atmosphere between the surface of the earth and the satellite collecting the image. This atmosphere has water vapor and aerosols therein that can cause the scattering of light, as well as clouds that can occlude ground areas that otherwise might be images. In addition, clouds can also block sunlight from directly illuminating areas that are being imaged.
[0002] Highly accurate classification of landcover types and states is essential to extracting useful information, insight and prediction for a wide variety of remote sensing applications. In many cases, this classification of type and state is dependent on multi-temporal observations. Remotely sensed measurements corrected to units of reflectance (ratio of incident electromagnetic energy to reflected energy) depend on properties of the material, while measurements of radiance (quantity of electromagnetic energy) are affected by numerous external environmental variables. Therefore, correction to reflectance is crucial for quantitative and multi-temporal applications.
[0003] In all cases, there are a number of confounding factors to deal with including opaque clouds, cirrus clouds, aerosols, water vapor, ice, snow, shadows, bidirectional reflectance distribution factor (BRDF) effects and transient coverings like water, dust, snow, ice and mobile objects. Pseudo invariant objects (PIOs) are often used for on-orbit calibration of relatively stable sensors because the PIOs are in useful states often enough. But there are not enough truly stable PIOs in the world with required spatial density to deal with the highly variable confounding factors of images.
SUMMARY
[0004] Disclosed herein is a method of creating modeled atmospheric correction objects. The method includes accessing a plurality of images of the Earth's surface to identify patches thereof that are relatively homogeneous and are likely to change over time in a predictable manner; and storing metadata associated with the patches including geographic coordinates of the patches, the angular position from which the image was captured, and the time and date that the image was captured.
[0005] The method may further include determining the surface reflectance for the patches. The surface reflectance for a portion of the patches may vary seasonally.
[0006] Also disclosed is a method of using modeled atmospheric correction objects (MACO). The method includes providing a plurality of MACO sites that are cross-referenced by geographic coordinates; obtaining an image of a portion of the surface of the Earth, for which geographic coordinates of the surface area covered by the image are known; and identifying MACO sites within the image based on geographic coordinates.
[0007] The method may further include determining which of the identified MACO sites are visible in the image and using the visible MACO sites to compute atmospheric parameters. The method may further include updating information associated with each visible MACO site.
[0008] Also disclosed is a method of detecting whether or not a MACO site is impacted by transient conditions (e.g., cloud shadow, structure shadow, wetness, or snow cover).
[0009] The method may further include determining which of the conditions impact the MACO site (e.g., may use green-yellow-red or green-red band signatures).
[0010] Also disclosed is a method of altering the observed MACO site radiance to compensate for shadow effects to enable comparisons with expected reflectance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The disclosure herein is described with reference to the following drawings, wherein like reference numbers denote substantially similar elements:
[0012] FIG. 1 is table of MACO classes and states.
[0013] FIG. 2 is an illustration of MACO clusters in an urban park.
[0014] FIG. 3 is an illustration of potential MACO sites.
[0015] FIG. 4 is an illustration of image-to-image variance in pixel positions.
[0016] FIG. 5 is a graph of the reflectance signature of four materials in the annual crop cycle.
[0017] FIG. 6 is a graph showing month-to-month signatures.
[0018] FIG. 7 are a set of graphs that show how various amounts of aerosols affect the signature of three different types of ground materials.
[0019] FIG. 8 is a flow diagram showing the main algorithm.
[0020] FIG. 9 is a flow diagram of a portion of the main algorithm.
[0021] FIG. 10 is an illustration of a satellite collecting images of the Earth's surface and communicating data to a ground station.
DETAILED DESCRIPTION
[0022] While the embodiments disclosed herein are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that it is not intended to limit the invention to the particular form disclosed, but rather, the invention is to cover all modifications, equivalents, and alternatives of embodiments of the invention as defined by the claims. The disclosure is described with reference to the drawings, wherein like reference numbers denote substantially similar elements.
[0023] Prior art makes simplifying assumptions as to the presence and stability of calibrating materials, and the uniformity of atmospheric effects that introduce significant errors across images. We have determined that ignoring the dynamic phenological variations and atmospheric element gradients within a scene can create classification errors of 45% or more. Multi-temporal anomaly detection suffers accordingly.
[0024] FIG. 10 shows a platform 20 , such as a satellite, sensing light coming thereto from the direction of a target 22 . The image sensor in the satellite or aerial vehicle measures the radiance (light energy) received at the sensor. Of course, the radiance received is a function of the position of the sun 24 , the position of the satellite, the atmosphere conditions (including the presence of clouds) and other factors. It is desirable to instead have the surface reflectance as opposed to the radiance received at the satellite, as it is a better indicator of the ground area to know how it reflects light as compared to how the ground area looks from the top-of-the-atmosphere with all the various atmospheric parameters affecting the image. The platform 20 can communicate with a ground station 26 to send image data thereto. The ground station 26 may perform various processing and/or storage of the image data and/or it may send the image data to other locations for processing and/or storage.
[0025] What are MACO Objects?
[0026] MACO clusters are effectively homogeneous clusters on the earth that are predictable enough that they can be used as estimators of ground truth in atmospheric correction inversion processes. MACO sites are interior patches within each MACO cluster ranging in size from as small as 2mร2m to as large as 60mร60m.
[0027] MACO clusters generally change throughout a year, but they do so in relatively predictable ways depending on their land use and how they interact with humans and their environments. We extend the general definition of phenotypes to this broader context. FIG. 1 shows the currently defined MACO phenotypes. Each MACO cluster is classified as one of the established types of calibration, stable or dynamic MACO as typified in FIG. 1 .
[0028] FIG. 2 shows a notional example of MACO clusters in the context of an urban park. The phenotypes for this example include deciduous forests, coniferous forests, rangeland, irrigated grasses, parking lot and a lake. Note that some areas within the park are potentially unsuitable because they are too heavily mixed or are likely to be covered by randomly distributed transient objects such as people, animals, and vehicles.
[0029] The projection of pixels from a sensor defines the boundaries of potential MACO sites. To be useful, most MACO sites need to be interior to the MACO cluster so that they have a reasonable probability of being homogeneous. There can be many reasons why a potential MACO site may not actually survive an arduous vetting process to become part of a control model. Those reasons are outlined in the discussion below. FIG. 3 shows an example of potential MACO sites that were actually selected (red tiles) based on proximity to MACO cluster boundaries and other factors. Note that the rest of the potential MACOS sites were not selected (clear tiles).
[0030] Although MACO cluster boundaries are fairly constant over time, potential MACO site boundaries are defined by the projection of sensor pixels onto the MACO clusters for a given image. FIG. 4 shows how selected MACO sites and site boundaries can vary in position and registration relative to the parent MACO cluster from image to image. This is simply due to variations from image to image due to the actual timing of the imaging operations and the exact location and attitude of the collection platform at the time.
[0031] The role that MACO sites play is elegantly simple in that they model the expected multi-spectral reflectance signature that should be obtained after all corrections are made. Differences between the expected reflectance signature values for each spectral band in a given MACO site and the surface reflectance estimate are related directly to the effects that must be corrected, albeit in a complex way. Atmospheric correction parameters can be generated using multiple MACO sites and other references within an image to create a surface reflectance value for each band at each pixel within the image under investigation.
[0032] MACO clusters are members of a diverse class of Models of Reality (MORs) that have three essential properties:
They represent fairly common land uses/land cover (LULC) types and as a result, nearly every square kilometer patch of the earth land surface has the potential to contain at least one MACO class object. Their state and appearance in the near future can be a reasonably estimated, given a recent estimate of their state and appearance, because their phenological behaviors follow well known progressions over time. They are big enough in extent that relatively pure, interior MACO site candidates within each MACO cluster or region can be identified and compared to other sites to verify their suitably for ground truth use.
[0036] MACO clusters fall into three distinct unmixed classes (see FIG. 1 ) and one mixed class:
Calibration MACO clusters are the previously mentioned PIOs located in very specific places in the world. Examples include White Sands Missile Range (WSMR), NM, Railroad Valley and Lunar Lake, N. Mex., Barreal Blanco, Argentina, regions of the Saharan Desert, and others. These locations tend to have minimal atmospheric effects or transient coverings often enough that they can be used for absolute calibration and characterization of longer term drift in sensors. Stable MACO clusters include expanses of barren land, coniferous trees, deep water, crushed rock, asphalt and concrete. The biological members of this class can go through modelable changes in appearance due to diurnal and seasonal effects. Transient coverings are easily detected using geography, time of year, weather and temperature records, and comparisons of observed spectral and spatial properties with known signature libraries. Dynamic MACO clusters include expanses of grass fields, broad area agriculture fields, parking lots and shallow water. The biological members of this class can go through fairly radical changes in appearance due to diurnal and seasonal effects. In a single year, a field of rotated corn or soybean, for example, can go from snow covered, to mixed soil and old harvest trash, to freshly tilled soil, to mixed soil and plants, to full canopy closure, to tasseling, to senescence, to harvesting, to mixed soil and harvest trash. Even though there is a lot of change, in one sense the progression is deterministic enough that errors in estimation of phenological phase, and physiological state are small compared to the positive benefit of the estimations of atmospheric conditions they enable. Transient coverings are easily detected using geography, time of year, weather and temperature records, and comparisons of observed spectral and spatial properties with known signature libraries. Mixed MACO clusters are the size of a MACO site. They are not homogenous. They are generated for a given image by estimating the spectral signature resulting from a linear combination of endmembers whose associated abundances are calculated directly from the observed fine spatial resolution panchromatic and multi-spectral imagery. The intent is to use this class of MACO sparingly until a sufficiently robust MACO library is established.
[0041] How are MACO Clusters Created?
[0042] MACO clusters are created by mining large global libraries of imagery looking for patches of earth that seem to change in predictable ways throughout the year. Large patches that show consistent group behavior are tessellated into roughly 300 m by 300 m or smaller MACO clusters. For each MACO cluster, we determine the basic MACO phenotype (see FIG. 1 ) and the various endmembers that are observed throughout the year. We obtain the nominal BRDF for each endmember from available sources, physical modeling and/or custom field measurements.
[0043] How are MACO Sites Prepared for Radiance-to-Reflectance Conversion Applications?
[0044] This section describes how specific MACO sites are selected and readied for use in external processes. FIGS. 8 and 9 describe the general flow.
[0045] Step 1 is to identify which MACO clusters and potential MACO sites are relevant to characterizing the atmospheric conditions and general states of the pixels in a given image. MACO clusters are either established prior to use, or may arise spontaneously for temporary use.
[0046] Established MACO clusters are already in the MACO Library, which can be searched to locate those MACO clusters that are interior to, or exterior, but proximate to an image boundary. Those MACO clusters that meet the criteria are included in the MACO Cluster List (MCL) for the image. Established MACO clusters are generally preferred because the essence of being an established MACO is that it is possible to make reasonably good predictions.
[0047] Temporary MACO clusters arise when either the established MACO clusters do not provide a dense enough mapping of candidate MACO sites to begin with within a sub-region of an image or because significant portions of established MACO clusters are impacted by transient effects such as snow. Homogeneous patches are identified within the low density sub-regions and then subjected to suitable radiance-to-reflectance (RTR) conversion functions using proximate MACO sites to drive the process. RTR conversion processes are not part of this invention.
[0048] The resultant spectral signature of the homogenous patch is then compared to the Master Signature Library. If there is a signature match, then a temporary MACO is created and added to the MCL for the image. The temporary MACO is also flagged for external consideration as a newly established MACO. If there is not a signature match, then the homogeneous patch is also flagged for external analysis and potentially its signature may be added to the Master Signature Library.
[0049] Every potential interior MACO site for each MACO cluster in the MCL is placed in the MACO Site List (MSL) for the image. The utility of each MACO site in the MSL is set initially to โusefulโ and as the processing progresses, the status of a number of the MACO sites in the MSL will be set to โrejectedโ.
[0050] Step 2 is to determine whether or not each MACO site in the MSL can be seen or not, i.e., is it blocked by an opaque cloud or a physical structure of some kind? The process to determine if it is blocked is not part of this invention. If the MACO site is blocked then we mark that MACO site as โrejectedโ and it will not participate in further correction processes for this image.
[0051] Step 3 is to establish the initial estimate of the expected endmember and state for each MACO site in the MSL. The expected endmember (e.g., corn) and state (e.g., growing/healthy) is updated for the current date based on the prior endmember and state, and elapsed time since the prior update. The nominal signature and BRDF for each endmember is retrieved for each MACO site in the MSL for use as the initial estimate of the expected reflectance using the sensor look and solar illumination vectors at the MACO site center for the date and time that it was imaged.
[0052] Step 4 involves a two pass process to determine utility and key parameters for each MACO site in the MSL. The first pass of Step 4 determines which of the useful MACO sites in the MSL are still useful and makes a gross correction to their expected endmembers, states and other parameters. The second pass refines the expected endmember, states and other parameters.
[0053] Step 4 a determines if โusefulโ MACO sites in the MSL are impacted by one of several transient conditions, e.g., cloud shadow, structure shadow, wetness, or snow cover. FIG. 5 shows the reflectance of four materials that are commonly part of the annual crop cycle. FIG. 6 shows how they might mix during the year to produce various signatures. FIG. 7 provides part of the evidence that to a first order, aerosol effects do not alter the green, yellow or red signature enough for three common land covers, e.g., green grass, coniferous trees and deciduous trees to be confused with snow or crop field endmembers, shadowed or not. Shadows can in some cases be less bright than in direct sunlight and slightly more bluish, depending on a number of conditions. Shadows can be relatively brighter if there is a lot of high level haze or there are proximate, highly reflective buildings and/or clouds.
[0054] So, we can determine whether or not we have shadows or no shadows on the nominal MACO site material or snow. Snow tends to be very flat between the green and red bands. Even if there is shadow on snow, the resultant green-yellow-red (or green-red) curve would not match the curves for sunlit soil, green grass or dry grass. Shadowed soil, green grass and dry grass are not likely to be confused by shadowed snow or each other. We can detect wetness conditions by comparing the dry and wet variants of the endmember and their respective BRDF. If we have good agreement with either the wet or dry variants, then we pick the best fitting endmember.
[0055] Step 4 b updates the transient conditions parameters for each MACO site in the MSL, e.g., cloud shadow, structure shadow, wetness, snow cover, dust cover. The presence of wetness, snow cover and/or dust is admissible for MACO sites, but it is necessary to reset the expected endmember and state parameters for the MACO site accordingly. The expected reflectance and actual observed radiance for all non-shadowed, non-rejected MACO sites are updated.
[0056] Step 4 c addresses special corrections for shadowed MACO site in the MSL. MACO sites are only useful as a set for atmospheric correction if they are consistent with sunlit conditions. If a given MACO site is shadowed, we assume that the expected reflectance is valid. But we need to alter the observed MACO site radiance signature from its darker shadowed state to a modeled sunlit state by using a simple function that effectively brightens each band in such a way to as to restore the effect of direct sunlight, including reversal of the bluish effect in the shadows. The expected reflectance and modeled sunlit observed radiance are updated for those shadowed MACO sites.
[0057] Step 4 d does a validity check for each MACO site in the MSL. For each MACO cluster in the MCL for the image, the entire set of MACO sites in that MACO cluster are then compared to each other using the green-yellow-red (or green-red) signatures. Any MACO site that is not in approximately the same spectral state as the spectral state of the largest group of MACO sites, after shadow compensation if appropriate, is rejected from further consideration as a MACO site in the MSL. This process keeps transient effects like vehicles, fire damage, disease, etc., from corrupting the process.
[0058] Step 4 e estimates the essential atmospheric correction parameters for each โstill usefulโ MACO site in the MSL. Because each useful MACO site is a โknown endmemberโ in a โknownโ state, an inversion process is used to estimate the essential atmospheric correction parameters that would explain the discrepancy between the expected MACO's reflectance and the retrieved reflectance.
[0059] Step 4 f updates a software model for the given image by storing the state parameters (e.g., location, BRDF, expected signature) and essential atmospheric correction parameters for each useful MACO site in the MSL. The model enables fine spatial fidelity radiance-to-reflectance correction processes in external atmospheric correction algorithms.
[0060] Step 4 g manages the two estimation passes. Once the first pass at estimating atmospheric conditions is done for the useful MACO sites, the second pass of the two pass process is executed using the first pass corrected reflectance signature for the useful MACO sites in the MSL as the starting expected signature instead of the nominal signature and BRDF. At the completion of the second pass, the state of the model for the given image is kept as the final.
[0061] How are MACO Clusters Maintained?
[0062] Final computed reflectance signatures corresponding to the specific imaging time are stored along with the BRDF geometries for each useful MACO site in the MSL and each MACO cluster in the MCL. To the extent practical, the multispectral signatures are used to adjust the hyperspectral signatures for the MACO sites, enabling their use by other collection platforms. An estimate is made of the most probable phenological and physiological state at that time and physical and/or empirical models based on time (phenology), BRDF geometries, and physiological state for the specific MACO material are updated accordingly to facilitate prediction of most probable states at next imaging event.
[0063] One application of the MACO techniques described herein is disclosed in concurrently-filed U.S. patent application Ser. No. 13/840,743, entitled โAtmospheric Compensation in Satellite Imageryโ identified in the law firm of Marsh Fischmann & Breyfogle LLP as 50224-00224, the contents of which are incorporated herein by reference.
[0064] While the embodiments of the invention have been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered as examples and not restrictive in character. For example, certain embodiments described hereinabove may be combinable with other described embodiments and/or arranged in other ways (e.g., process elements may be performed in other sequences). Accordingly, it should be understood that only example embodiments and variants thereof have been shown and described.
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Techniques for making, using and updating a Modeled Atmospheric Correction Object (MACO) cluster and the MACO sites that are selected from within a given MACO cluster. The MACO construct is a novel application of a Model of Reality (MOR) that provides synthetic ground truth essential to converting imagery from top-of-the-atmosphere radiance to surface reflectance given a variety of spatial, spectral and radiance effects involving non-uniform distributions of opaque clouds, cirrus clouds, aerosols, water vapor, surface ice, surface snow, shadows and bidirectional reflectance distribution function (BRDF) effects.
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RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. ยง 19(e) to provisional application No. 60/681,920 filed on May 16, 2005 titled โHigh Temperature Direct Coal Fuel Cell.โ
FIELD OF THE INVENTION
[0002] This invention relates to the field of fuel cells, and in particular to the field of high temperature fuel cells for the direct electrochemical conversion of carbon-containing materials (such as coal) to electrical energy. This invention is further directed to fuel cells employing a single temperature zone. This invention is further directed to fuels cells wherein therein is direct physical contact of the anode surface with carbon particles.
BACKGROUND OF THE INVENTION
[0003] Coal is the most abundant and inexpensive energy source on our planet with sufficient reserves to meet a large fraction of the world's energy needs for many decades, even centuries to come. Other energy sources such as wind, solar, geothermal, and nuclear offer limited capacity only. As demand for energy resources increases with accelerating pace to fuel the rapidly growing economies of populated countries like China, India, Brazil and Russia, there is a compelling and impending need to find more efficient and responsible ways to use coal, as these countries both possess vast reserves of this valuable resource and use it in great proportion for their electricity generation. For example, China generates more than 70% of its electricity from coal. That number is about 56% for the US.
[0004] Conversion of the chemical energy of coal to electricity ordinarily requires multiple processing steps that suffer from Camot constraints and ultimately results in low conversion efficiencies. Typically, subcritical coal fired power plants operate with poor efficiencies of 33-35%. Recently, emerging coal technologies have slightly improved efficiencies that may reach up to 42-45% for ultra-super critical and integrated gas combined cycle processes. However, these are relatively new and expensive technologies with capital costs in excess of $1700/kW without CO 2 capture and more than $2200/kW with CO 2 capture [N. Holt, GCEP Advanced Coal Workshop, Provo, Utah, Mar. 15, 16 (2005)].
[0005] In contrast, the process of direct electrochemical conversion of coal to electrical energy proposed here is a single step process and is not subject to Camot constraint. Hence, it offers the possibility of achieving substantially higher conversion efficiencies than chemical conversion processes. This is partly due to the high ceiling value of the theoretical efficiency for electrochemical conversion of carbon to carbon dioxide, which remains at about 100% even at elevated temperatures due to near-zero entropy change of the reaction.
[0006] Possibility of direct coal conversion in a fluidized bed fuel cell was originally suggested by Gรผr [T. M. Gรผr and R. A. Huggins, J. Electrochem. Soc. 139 (#10), L95 (1992), U.S. Pat. No. 5,376,469 Dec 27, 1994] that utilized a fixed carbon bed in a solid oxide fuel cell. This early attempt employed a thick (1.5 mm wall) stabilized zirconia tube. It was also a preliminary study for proof-of-concept only that was far from being optimized. Nevertheless, it successfully demonstrated that it was possible to draw currents in excess of 30 mA/cm 2 and obtain open circuit voltages that agreed with theoretically expected values.
[0007] The quest for direct carbon conversion to electricity is not new, however, and has been pursued in waves of activity for over 150 years. The earliest attempt to directly consume coal in a fuel cell was made by Becquerel in 1855[K. R. Williams, in โAn Introduction to Fuel Cellsโ, Elsevier Publishing Company, Amsterdam (1966), Chap.1]. He used a carbon rod as the anode and platinum as the oxygen electrode in a fuel cell that employed molten potassium nitrate as the electrolyte. When oxygen was blown on to the Pt electrode a current was observed in the external circuit. However, his results were not encouraging because of the direct chemical oxidation of carbon by the potassium nitrate electrolyte.
[0008] Near the turn of the century, Jacques [W. W. Jacques, Harper's Magazine, 94, 144 (December 1896-May 1897)] used a molten sodium hydroxide electrolyte contained in an iron pot, which served as the air cathode, and a carbon rod as the consumable anode. The cell was operated at about 500 ยฐ C. and current densities of over 100 ma/cm 2 were obtained at about 1 volt. He constructed a 1.5 kW battery consisting of over 100 of these cells and operated it intermittently for over six months. Unfortunately, Jacques did not give reliable information about cell characteristics and life of his battery. Haber and Brunner [F. Haber and L. Bruner, Z. Elektrochem., 10, 697 (1904)] suggested that the electrochemical reaction at the anode in the Jacques cell was not the oxidation of carbon but of hydrogen that was produced, along with sodium carbonate, by the reaction of carbon with molten sodium hydroxide. Owing to this undesirable side reaction involving the electrolyte and rendering it unstable in that environment, Baur and co-workers [E. Baur, Z. Elektrochem., 16, 300 (1910); E. Baur and H. Ehrenberg, Z. Elektrochem., 18, 1002 (1912); E. Baur, W. D. Treadwell and G. Trumpler, Z. Elektrochem., 27, 199 (1921)] abandoned the molten alkali electrolytes and replaced them by molten salts such as carbonates, silicates and borates.
[0009] In 1937, Baur and Preis [E. Baur and H. Preis, Z. Elektrochem., 43, 727 (1937)] suggested that the condition for a chemically stable electrolyte can only be met by the use of an ionically conducting solid electrolyte. For this purpose, they built a battery consisting of eight yttria stabilized zirconia electrolyte crucibles immersed in a common magnetite (i.e., Fe 3 O 4 ) bath. The anode compartment was filled with coke and the cell was operated at about 1050ยฐ C. The open circuit battery potential was 0.83 volts, about 0.2 volts lower than that measured with single cells. At a cell voltage of about 0.65 volts the current density was about 0.3 mA/cm 2 , too low for practical use. Furthermore, at these high operating temperatures, it is thermodynamically possible to carry out only partial oxidation of carbon, which would hence reduce the efficiency of the fuel cell significantly.
[0010] In the last several decades, high temperature fuel cells employing either molten carbonate or solid oxide ceramic electrolytes have been reported. In these cells, coal derived fuels [D. H. Archer and R. L. Zahradnik, Chem. Eng. Progr. Symp. Series, 63, 55 (1967)], H 2 [J. Weissbart and R. Ruka, in โFuel Cellsโ,Vol. 2, G. J. Young (ed.), Reinhold Publishing Corp., New York (1963)] and CH 4 [J. Weissbart and R. Ruka, J. Electrochem. Soc., 109, 723 (1962)] were employed as consumable gaseous fuels. Presently, the high temperature solid oxide fuel cells under development in various laboratories around the world use H 2 derived either from natural gas or from coal.
[0011] More recently, there have been several development efforts that utilize some form of a molten medium in an attempt to generate electricity from carbon. The molten media that were employed can be grouped of two categories, namely, molten salts and molten metals, both of which serve to hold the carbon source.
[0000] Molten Salt Electrolyte Based DCFC
[0012] Scientific Applications and Research Associates, Inc. (SARA) has been involved in developing a molten hydroxide fuel cell operating at 400-500ยฐ C. [www.sara.com/energy; โCarbon Air Fuel Cellโ U.S. Pat. No. 6,200,697 (Mar. 3, 2001)]. The cell consists of a carbon anode surrounded by a molten hydroxide electrolyte. Air is forced over the metallic cathode where the reduction of oxygen generates hydroxide ions. The hydroxide ions are transported through the molten NaOH electrolyte to the anode where they react with the carbon anode releasing CO 2 , H 2 O, and electrons. These electrons travel through the external circuit to the cathode, and generate electricity.
[0013] Building upon the earlier work done at SRI International by Weaver and co-workers [R. D. Weaver, S. C. Leach, A. E. Bayce, and L. Nanis, โDirect Electrochemical Generation of Electricity from Coalโ, SRI, Menlo Park, Calif. 94025; SAN-0115/105-1 (1979) ] who employed a carbon anode in a molten carbonate electrolyte system for direct conversion of carbon to electricity, Lawrence Livermore National Laboratory [N. J. Cherepy, R. Krueger, K. J. Fiet, A. J. Jankowski, and J. F. Cooper, J. Electrochem. Soc. 152(1), A80 (2005); J. F. Cooper โDirect Conversion of Coal and Coal-Derived Carbon in Fuel Cellsโ, Second International Conference on Fuel Cell Science, Engineering and Technology, ASME, Rochester, N.Y., Jun. 14-16, 2004; โFuel Cell Apparatus and Method Thereofโ, U.S. Pat. No. 6,815,105 (Nov. 9, 2004) ] has been developing a similar system which employs a molten carbonate electrolyte that holds nanosize carbon particles dispersed in it. The anode and cathode compartments are separated by a porous yttria stabilized zirconia (YSZ) matrix, which serves to hold the molten electrolyte and allows transport of carbonate ions from the anode side to the cathode compartment. Suitable metals such as Ni are employed for anode and cathode materials. At the anode, dispersed carbon particles react with the carbonate ion to form CO 2 and electrons, while oxygen from air react with CO 2 at the cathode to generate carbonate ions. As the carbonate ions formed at the cathode migrate through the molten electrolyte towards the anode, the electrons liberated at the anode travel through the external circuit towards the cathode generating electricity.
[0000] Molten Anode Based DCFC
[0014] Yentekakis and co-workers [I. V. Yentekakis, P. G. Debenedetti, and B. Costa, Ind. Eng. Chem. Res. 28, 1414 (1989)] published a paper-study and proposed the concept for and simulated the expected performance of a direct carbon conversion fuel cell employing a molten Fe anode and an yttria stabilized zirconia (YSZ) solid electrolyte immersed in the molten anode. The operating temperature of such a cell would necessarily be higher than the melting point of Fe, which is 1535ยฐ C. Indeed, their modeling was done for extremely high temperatures up to 2227ยฐ C. (or 2500ยฐ K). It was assumed that finely divided carbon particles are dispersed in the molten Fe anode. They suggested coating the cathode side of the YSZ electrolyte with a porous layer of Pt where the oxygen from the air would undergo a reduction reaction. The resulting oxide ions would be transported through the YSZ solid electrolyte towards the anode where they would emerge into the molten Fe bath and react with the dispersed carbon particles. The electrons released during this anodic reaction would travel in the external circuit generating electricity.
[0015] A similar approach has been pursued by CellTech Power, Inc., which recently patented [โCarbon-Oxygen Fuel Cellโ, U.S. Pat. No. 6,692,861 B2 (Feb. 17, 2004)] a fuel cell that uses a carbon-based anode. Their web site portrays a fuel cell [www.celltechpower.com] that employs molten Sn as anode and reports that the cell operates in a two-step process. During the first phase, the oxygen transported through a stabilized zirconia solid electrolyte oxidizes the molten Sn anode to SnO. In the second step, carbon fuel delivered into the anode compartment reduces the SnO back to metallic Sn, and the cycle is repeated.
[0016] The present invention is fundamentally different from these prior approaches. It employs a dense and nonporous solid oxide ceramic electrolyte for selectively transporting oxygen necessary for oxidizing carbon. While others employ either electronically nonconducting molten salt electrolytes or electronically conducting molten metal anodes, the proposed concept uses instead a gas-solid system where mass transport and kinetic rates are significantly higher than for liquid-solid systems. Hence, the expected power densities in this proposal will proportionately be higher. Operationally, it also less complicated to deal with and study reactions in gas-solid interfaces than in the double and triple phase interfaces employed in the molten electrolyte or molten anode gas-solid-liquid systems above.
[0000] Properties of Solid Oxide Electrolytes
[0017] An important component of the direct coal fuel cell (DCFC) is the solid oxide electrolyte that facilitates selective oxide ion transport and supplies the oxygen for the oxidation of carbon and other reactants (such as hydrogen, sulfur etc) at the anode. Predominantly oxide-ion conducting solids have been known to exist for almost a century [W. Nernst, Z. Elektrochem., 6, 41 (1900)]. Among these solids, zirconia-based electrolytes have widely been employed as electrolyte material for solid oxide fuel cells (SOFC).
[0018] Zirconium dioxide has three well-defined polymorphs, with monoclinic, tetragonal and cubic structures. The monoclinic phase is stable up to about 1300ยฐ C. and then transforms to the tetragonal phase. The cubic phase is stable above 2200ยฐ C. with a CaF 2 structure. The tetragonal-to-monoclinic phase transition is accompanied by a large molar volume (about 4%), which makes the practical use of pure zirconia impossible for high temperature refractory applications. However, addition of 8-15 m % of alkali or rare earth oxides (e.g., CaO, Y 2 O 3 , Sc 2 O 3 ) stabilizes the high temperature cubic fluorite phase to room temperature and eliminates the undesirable tetragonal-to monoclinic phase transition at around 1300ยฐ C. The dopant cations substitute for the zirconium sites in the structure. When divalent or trivalent dopants replace the tetravalent zirconium, a large concentration of oxygen vacancies is generated to preserve the charge neutrality of the crystal. It is these oxygen vacancies that are responsible for the high ionic conductivity exhibited by these solid solutions. These materials also exhibit high activation energy for conduction [T. M. Gรผr, I. D. Raistrick and R. A. Huggins, Mat. Sci. Engr., 46, 53 (1980); T. M. Gรผr, I. D. Raistrick and R. A. Huggins, Solid State Ionics, 1, 251 (1980)] that necessitates elevated temperatures in order to provide sufficient ionic transport rates. The electronic contribution to the total conductivity is several orders of magnitude lower than the ionic component at these temperatures. Hence, these materials can be employed as solid electrolytes in high temperature electrochemical cells.
[0019] Ionic conduction in these materials is a highly thermally activated process with strong temperature dependence and large activation energy of about 1 eV. In fact, ionic conductivity for the oxide ions increases exponentially with temperature, dictating the need of high operating temperatures for fast transport rates. Therefore, it is desirable for the solid oxide electrolyte to operate between 600 to 1100ยฐ C. in order to provide sufficiently fast transport rates for the oxide ions that would make it attractive for practical use.
[0020] The chemical potential difference of oxygen across the solid oxide electrolyte is a measure of the open circuit potential given by the Nernst Equation,
E=โ ( RT/nF ) ln (PO 2 โฒ/PO 2โณ) โโ(1)
where E is the equilibrium potential of the fuel cell under open circuit conditions, R is the gas constant, F is Faraday's constant, n is the number of electrons per mole ( in the case of O 2 , n = 4 ), and PO 2 denotes the partial pressure of oxygen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 shows the theoretical conversion efficiency and the expected open circuit voltage as a function of temperature for the electrochemical oxidation reaction of carbon. Note the temperature independence of E and efficiency for the carbon oxidation reaction, while the behavior is strongly dependent on temperature for the case of hydrogen
[0022] FIG. 2 . Schematic design and operating principle of the direct carbon fuel cell depicting the details of the cell cross section (not to scale), ionic transport, and electrode reactions. Right: The thin film solid oxide electrolyte (white annulus) is sandwiched between the porous cathode support tube indicated by the inner gray shade, and the outer porous anode layer. Left: solid electrolyte and the cathode allows transport of oxide ion only, which oxidize carbon at the anode and release its electrons to the external circuit generating electricity. In a preferred embodiment, the direct carbon fuel cell may be operated at a single temperature, such that the reaction is in a single temperature zone.
[0023] FIG. 3 . Schematic stalactite design of the agitated bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell and the capability to capture any entrained coal particles in a cyclone, and recycling the captured coal particles and part of the CO 2 back to the coal bed, the latter in order to enhance mass transport by agitation.
[0024] FIG. 4 . Schematic stalactite design of the agitated bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell and recycling part of the CO 2 back to the coal bed in order to enhance mass transport by agitation.
[0025] FIG. 5 . Schematic stalactite design of the immersion bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell. There is no recycling of the CO 2 back to the coal bed for agitation.
[0026] FIG. 6 . Schematic stalagmite design of the immersion bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell. There is no recycling of the CO 2 back to the coal bed for agitation.
[0027] FIG. 7 . Shell-and-tube type design where the pulverized coal bed is outside the tube in touch with the anode surface. This particular schematic does not illustrate CO 2 or captured coal rcycling, but these features can easily be incorporated and falls within the scope of this invention.
[0028] FIG. 8 . Shell-and-tube type design (inverted version of FIG. 7 ) where the pulverized coal bed is now inside the tube in touch with the anode surface that is also inside the tube. The annulus between the metal shell and the cathode surface facing the metal shell allows a flow of air. This particular schematic does not illustrate CO 2 or captured coal recycling, but these features can easily be incorporated and falls within the scope of this invention.
[0029] FIG. 9 . Schematic of the two-chamber flat plate fluidized bed fuel cell design where the pulverized coal bed is in touch with the anode surfaces of the ceramic membrane assemblies. More chambers are possible. This particular schematic also applies to corrugated plate design of ceramic membrane assemblies. It does not illustrate CO 2 or captured coal recycling, but these features can easily be incorporated and falls within the scope of this invention.
SUMMARY OF THE INVENTION
[0030] The invention is directed to a fuel cell for the direct conversion of a carbon-containing fuel into electricity. The fuel cell comprises an anode, a cathode, and an electrolyte. In a preferred embodiment, there is a thin film solid oxide electrolyte which is sandwiched between a porous cathode and an outer porous anode layer. In a preferred embodiment, the fuel cell operates at elevated temperature, with a single temperature zone. In another preferred embodiment, the fuel cell utilizes direct physical contact of an anode surface with carbon-containing particles.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The electrochemical conversion of coal into electricity involves a high temperature fuel cell that features an oxide ion selective solid electrolyte that supplies the oxygen required for the electrochemical oxidation of carbon. Pulverized coal is introduced into the anode compartment of the cell with or without other solid constituents, such as sequestering agents for capturing the CO 2 and SO 2 produced.
[0032] FIG. 1 shows the theoretical conversion efficiency and the expected open circuit voltage as a function of temperature for the electrochemical oxidation reaction of carbon. Note the temperature independence of E and efficiency for the carbon oxidation reaction, while the behavior is strongly dependent on temperature for the case of hydrogen.
[0033] Referring to Eq. (1), the open circuit voltage of the fuel cell is determined by the carbon-oxygen equilibrium at the anode, since the oxygen activity on the cathode side is fixed by air. FIG. 1 shows the theoretical conversion efficiency and the expected open circuit voltage as a function of temperature for the electrochemical oxidation reaction of carbon. The figure also compares the carbon-oxygen couple with that for hydrogen, which shows strong temperature dependence. In other words, a solid oxide fuel cell (SOFC) using hydrogen as fuel and operating at high temperatures will have significantly lower open circuit voltage as well as theoretical efficiency than one that employs carbon as fuel. This is primarily because the entropy change during carbon oxidation is negligibly small, and the Gibbs free energy for carbon oxidation is nearly independent of temperature. The situation is different for the oxidation of hydrogen, which exhibits a strongly negative temperature dependence. Moreover, for hydrogen to be employed as fuel, it needs to be produced from other resources first, while carbon is an abundant and cheap source of energy that is readily available. So there is a great incentive to employ the carbon-oxygen couple. Indeed, FIG. 1 clearly indicates 100% theoretical efficiency and slightly over 1 volt open circuit voltage, both of which are practically independent of temperature over the entire useful range.
[0034] FIG. 2 shows a schematic design and operating principle of the direct carbon fuel cell depicting the details of the cell cross section (not to scale), ionic transport, and electrode reactions. Right: The thin film solid oxide electrolyte (white annulus) is sandwiched between the porous cathode support tube indicated by the inner gray shade, and the outer porous anode layer. Left: solid electrolyte and the cathode allows transport of oxide ion only, which oxidize carbon at the anode and release its electrons to the external circuit generating electricity.
[0035] A typical schematic of the fuel cell ceramic tube involves a thick porous ceramic cathode that provides mechanical integrity for the multilayer structure. Another typical schematic of the fuel cell involves flat or corrugated plates of multilayered ceramic membrane assemblies. Other cell geometries, including flat tubes, rectangular or square tubes, and planar configurations, etc. are also possible and is covered under this invention. A thin, impervious layer of yttria stabilized zirconia (YSZ) solid electrolyte is coated on the outer surface of the cathode tube. Another thin but preferably porous layer that serves as the anode is then deposited on top of the YSZ as the outermost layer. A schematic of the tube structure and its operating principle is shown in FIG. 2 . Typically, the YSZ and porous anode layers are each 10-50 ฮผm thick, while the cathode support tube may be about 1-2 mm in wall thickness. The porous cathode support tube is made of a mixed conducting perovskite while the porous anode layer is typically made of catalytically active cermet or a mixed conducting oxide.
[0036] FIG. 2 shows an anode 202 , a solid oxide electrolyte 204 , a cathode 206 , oxygen ions 208 , air 210 , a seal 212 , and a metal shell 214 .
[0037] YSZ is the preferred solid electrolyte 204 for its high stability and ionic conductivity. However, scandia stabilized zirconia (SSZ) has an even higher conductivity than its yttria counterpart [T. M. Gรผr, I. D. Raistrick and R. A. Huggins, Mat. Sci. Engr., 46, 53 (1980)]. Also, it is possible to employ tetragonal zirconia which is known to possess higher conductivity and better thermal shock resistance than cubic zirconia electrolytes. Similarly, other oxide ion conductors such as doped cerates (e.g. Gd 2 O 3 .CeO 2 ) and doped gallates (e.g., La 2 O 3 .Ga 2 O 2 ) can also be considered for the thin electrolyte 204 membrane.
[0038] The inner surface of the cathode 206 support tube is in contact with air 210 to furnish the oxygen 208 needed for the oxidation reaction at the anode 202 , while the outer surface of the anode 202 is in direct, physical contact with the carbon fuel. The YSZ solid oxide electrolyte 204 film in between serves as a selective membrane for transporting oxygen 208 ions from the air 210 , leaving behind the nitrogen. The oxygen 208 picks up electrons from the external circuit through the cathode 206 and is reduced to oxide ions, which are then incorporated into the YSZ solid electrolyte 204 .
[0039] Using Kroger-Vink defect notation, the electrochemical reduction of oxygen 208 at the cathode 206 takes place as follows:
O 2(g) +2V o .. (YSZ) +4 eโฒ (electrode) =2O o x (YSZ) โโ(2)
[0040] While the oxygen vacancies, V o .. (YSZ) , migrate under the influence of the chemical potential gradient through the YSZ solid electrolyte 204 film from the anode 202 to the cathode 206 , oxygen 208 ions are transported in the reverse direction from the cathode 206 to the anode 202 where they participate in the electrochemical oxidation of carbon.
C +20 o x (YSZ) =CO 2(g) +2V o .. (YSZ) +4eโฒ (electrode) โโ(3)
[0041] The electrons released during the oxidation reaction at the anode 202 travel through the external circuit towards the cathode 206 , producing useful electricity. The oxygen 208 chemical potential difference between the anode 202 and the cathode 206 (i.e., air 210 ) provides nearly 1 volt of open circuit voltage.
[0042] For obtaining maximum conversion efficiency, it is important that the oxidation reaction of carbon primarily takes place at the anode 202 surface by lattice oxygen (i.e., Eq. (3)). The presence of lattice oxygen is preferred in embodiments involving the single temperature reaction zone and the direct physical contact of the anode 202 surface with the particles of carbon-containing fuel.
[0043] Expressed this time in ionic notation, the desired reaction is
C (s) +2O 2- (YSZ) =CO 2 (g)+ 4eโฒ(electrode)โโ(4)
So many of the gas phase reactions should be minimized. These include the reactions at the solid carbon-gas interface,
C (s) +ยฝO 2(g) =CO (g) โโ(5)
C (s) +O 2(g) =CO 2(g) โโ(6)
as well as the gas phase oxidation of CO by molecular oxygen 208 supplied from the cathode 206 through the YSZ electrolyte 204 .
CO (g) +ยฝO 2(g) =CO 2(g) โโ(7)
and the reverse Bouduard reaction that leads to carbon precipitation
2CO (g) =C (s) +CO 2(g) โโ(8)
In short, the desired reaction is (4) for obtaining maximum conversion efficiency. Therefore it is important to bring coal particles in direct physical contact with the active anode 202 surface. This can only be achieved if the anode 202 surfaces and the coal particles reside in immediate physical proximity such that they experience the same temperature regime, and not thermally and spatially separated from one another. Hence, a single temperature zone fuel cell reactor design is the preferred embodiment in this invention where the active surfaces of the anode 202 and the coal particles experience direct physical contact and the same temperature space.
[0044] This is achieved by immersing the solid electrolyte 204 containing cell tubes inside the pulverized coal bed, where the coal bed and the tubes reside in the same thermal zone. The coal particles touching the anode 202 surface are readily oxidized by the oxygen 208 provided at the anode 202 surface through the solid electrolyte 204 membrane. Since the electrolyte 204 membrane is selective only to oxygen 208 , the nitrogen component of air 210 stays behind in the cathode 206 compartment. This way, there is no N 2 or oxides of nitrogen (NO x ) produced in the coal bed other than whatever nitrogen was present in the coal feed originally. The absence of N 2 and NO x in the flue gas stream is of course a major advantage of this invention in many important ways. It eliminates emissions of toxic NO x into the environment, and where regulated, it also eliminates very expensive separation and purification processes for removing NO x from the flue gases before they are discharged into the atmosphere. Furthermore, it eliminates the latent heat lost to N 2 during the combustion process, as is the case in conventional coal-fired power generation technologies. Finally, this invention makes it easy and inexpensive to capture and sequester the CO 2 since the flue gases from the direct coal fuel cell is primarily CO 2 . This point is important for compliance with Kyoto protocols regarding greenhouse gas emissions.
[0045] The carbon-fuel comprises any carbon rich substance including: all grades and varieties of coal, charcoal, peat, petroleum coke, oil sand, tar sand, coke, char, carbon produced by pyrolysis of a carbonaceous substance, waste plastics, and biomass. For brevity, the carbon-fuel substances listed above may be referred to as โcoalโ in this document.
[0046] Several different design alternatives are provided as examples to achieve direct, physical contact of the anode 202 surface with the coal particles. Other design alternatives are also possible. These designs may or may not involve recycling or circulation of an inert gas, such as He, Ar, N 2 or CO 2 , to agitate the coal bed to enhance mass transport of reaction products away from the anode 202 surface so as not to block, hinder, or slow down the next unit of oxidation reaction taking place.
[0047] The coal bed operates in the temperature range 500 to 1300ยฐ C. This range provides the spectrum for the optimum operation of the coal bed and the oxidation process. Thermodynamically, conversion of carbon to carbon dioxide has an inverse temperature dependence and hence is favored more with decreasing temperatures. More specifically, the formation of CO 2 is thermodynamically favored at temperatures below about 720ยฐ C., while the partial oxidation product CO is stable above this temperature. In other words, the thermodynamic cross over between full oxidation and partial oxidation of carbon occurs around 720ยฐ C. Naturally, thermodynamics dictate only the natural tendency of a system to change or react, but does not govern how fast the system undergoes change. Kinetics and diffusion dictate collectively how fast a reaction or change will occur, and this is an exponential function of temperature. So higher temperatures offer faster reaction rates.
[0048] Accordingly, the kinetics and product distribution of the carbon conversion reaction is best optimized when the operating temperature range of the coal bed lies between 500 to 1300ยฐ C.
[0049] There is another consideration that affects the operating temperature of the system. That has to do with the transport of oxide ions through the ceramic electrolyte 204 membrane, which is a highly thermally activated process as discussed earlier, and prefers high operating temperatures. The oxide ions transported across the membrane oxidize the carbon at the anode 202 compartment to generate electricity. In order to produce practically significant and useful levels of electrical current, which is intimately associated with the transport rate of oxide ions through the membrane via the well-known Faraday's equation, the coal bed may operate between 600 and 1100ยฐ C., where the ionic conductivity of the electrolyte 204 membrane is larger than 10 โ4 S/cm. To obtain even better performance, the coal bed may optionally operate in a temperature range of 700 to 1000ยฐ C.
[0050] FIG. 3 shows a chematic stalactite design of the agitated bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell and the capability to capture any entrained coal particles in a cyclone, and recycling the captured coal particles and part of the CO2 back to the coal bed, the latter in order to enhance mass transport by agitation.
[0051] FIG. 3 shows coal fuel 302 , a resistive load 304 , a coal bed 306 , electrodes 308 , CO 2 310 , a membrane assembly 312 , recycled CO 2 314 , and ash and slag 316 .
[0052] The schematic of the agitated bed direct coal fuel cell shown in FIG. 3 illustrates the general design features including the stalactite design of one-end closed ceramic tubular cell. The agitated bed is preferably made of a stainless steel shell with proper ports for feeding the pulverized coal into the bed, and discharging the flue gases. It also has the capability to capture any entrained coal particles in a cyclone, and recycling both the captured coal particles and part of the CO 2 gas 314 back to the coal bed 306 , the latter in order to enhance mass transport by agitation of the coal bed 306 by gas flow.
[0053] FIG. 4 shows a schematic stalactite design of the agitated bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell and recycling part of the CO2 back to the coal bed in order to enhance mass transport by agitation.
[0054] FIG. 5 shows a schematic stalactite design of the immersion bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell. There is no recycling of the CO2 back to the coal bed for agitation.
[0055] Variant modes of the stalactite design are shown in FIGS. 4 and 5 as examples, where the former shows only CO 2 recycling 314 for agitation of the coal bed 306 .
[0056] Another design concept shown in FIG. 5 is an immersion bed direct coal fuel cell where the coal bed 306 is immobile and there is no forced agitation of the bed caused by the recycling of the CO 2 product gas.
[0057] FIG. 6 shows a schematic stalagmite design of the immersion bed direct coal fuel cell illustrates the general design features including one-end closed ceramic tubular cell. There is no recycling of the CO2 back to the coal bed for agitation.
[0058] Yet another design concept is the stalagmite configuration of the ceramic tube cells as depicted in FIG. 6 , which also illustrates an immersion type of coal bed 306 operation without CO 2 recycling 314 . Naturally, the stalagmite design concept is also possible for the other modes of operation described above, as well as others.
[0059] FIG. 7 shows a shell-and-tube type design where the pulverized coal bed is outside the tube in touch with the anode surface. This particular schematic does not illustrate CO2 or captured coal recycling, but these features can easily be incorporated and falls within the scope of this invention.
[0060] Other design concepts may include shell-and-tube type design where the pulverized coal bed 306 is outside the tube in touch with the anode 202 surface as illustrated in FIG. 7 . This particular schematic does not illustrate CO 2 314 or captured coal recycling, but these features can easily be incorporated and falls within the scope of this invention.
[0061] FIG. 8 shows spent air 802 and an air flow annulus 804 .
[0062] FIG. 8 shows a shell-and-tube type design (inverted version of FIG. 7 ) where the pulverized coal bed is now inside the tube in touch with the anode surface that is also inside the tube. The annulus between the metal shell and the cathode surface facing the metal shell allows a flow of air. This particular schematic does not illustrate CO2 or captured coal recycling, but these features can easily be incorporated and falls within the scope of this invention.
[0063] Another variant of this is the inverted shell-and-tube type design (i.e., inverted version of FIG. 7 ) where the pulverized coal bed 306 is now inside the tube in touch with the anode 202 surface that is also inside the tube as shown in FIG. 8 . The annulus between the metal shell and the cathode 206 surface facing the metal shell allows a flow of air 210 . This particular schematic does not illustrate CO 2 314 or captured coal recycling, but these features can easily be incorporated and falls within the scope of this invention.
[0064] FIG. 9 shows a schematic of a two chamber flat plate fluidized bed design where the pulverized coal bed is in touch with the anode surfaces of the ceramic membrane assemblies. More chambers are possible. This particular schematic also applies to corrugated plate design of the ceramic membrane assemblies. It does not illustrate CO2 or captured coal recycling, but these features can easily be incorporated and falls within the scope of this invention.
[0065] Although similar in operation, another design geometry involves the use of flat or corrugated planar ceramic membrane assemblies 312 . These are multilayered structures that consist of porous anode 202 (or cathode 206 ) support plates coated with thin impervious layers of the oxide conducting solid electrolyte 204 membrane, over which there is coated another thin but porous electrode layer to complete the fuel cell structure. The plates are stacked in parallel fashion in the reactor as shown in FIG. 9 such that the anode 202 surfaces face each other. Carbon-fuel 302 is fed in between the anode 202 surfaces in alternating pairs of plates while air 210 is flown along the outer surfaces that act as cathodes for the reduction of oxygen 208 .
[0066] Yet another mode of operating the direct coal fuel cell is to couple it to CO 2 and SO 2 sequestration either inside the bed or outside the bed. Sequestration of CO 2 and SO 2 can be achieved inside the bed by introducing gettering agents such as calcium oxide, magnesium oxide, dolomite, a variety of micas, clays, and zeolites, or a variety of magnesium silicates (e.g., olivine, serpentine, talc) mixed with pulverized coal and fed directly into the bed. Mica, clay and zeolite individually refer to large families of minerals and materials. Examples of micas include muscovite, biotite, lepidolite and phlogopite; clays include montmorillonite, bentonite, hematite, illite, serpentine, and kaolinite; and zeolites include clinoptilolite, chabazite, phillipsite, mordenite, molecular sieves 13X, 5A, and ZSM-5. Of course, other members of the mica, clay and zeolite families are also applicable under this invention. All these inorganic compounds may be used to sequester carbon dioxide and oxides of sulfur. The gettering agents readily react with these oxidation products inside the bed forming solid carbonates and sulfates which eventually settle to the bottom of the bed due to their much denser bodies compared to coal, where they can be extracted. Or the flue gas leaving the bed can be treated with these gettering agents in a separate containment outside the bed where the reaction products CO 2 and SO 2 can easily be sequestered by fixing them as solid carbonates and sulfates. Some of the relevant reactions for mineral carbonization are provided below as examples.
Lime: CaO+CO 2 =CaCO 3 Magnesia: MgO+CO 2 =MgCO 3 Serpentine: Mg 3 Si 2 O 5 (OH) 4(s) +3CO 2(g) =3 MgCO 3(s) +2 SiO 2(s) +2 H 2 O Olivine Mg 2 SiO 4(s) +2 CO 2(g) =2 MgCO 3(s) +SiO 2(s)
There are many embodiments of the present invention:
A fuel cell using a single temperature zone. A fuel cell using direct physical contact (or touching) of anode surface with the coal particles. A fuel cell using immersion or agitated bed to materialize contact. A fuel cell using carbon directly, rather than intermediate conversion of coal to gaseous products. A method of converting coal to electricity without the use of large quantities of water in contrast to the current technologies employed in coal-fired power plants A fuel cell wherein there is a one step process for direct conversion of coal to electrical energy. A process that does not combust coal, but oxidizes it. A fuel cell that utilizes solid oxide electrolyte to supply the oxygen for the electrochemical oxidation of coal. A fuel cell that produces highly concentrated (85-95% CO 2 ) flue gas that enables easy capturing and sequestration of the carbon dioxide. A fuel cell that offers single source collection of CO 2 . A fuel cell that utilizes mineral carbonization. A fuel cell that offers potentially near-zero emissions and stackless operation.
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The invention relates to direct conversion of coal into electricity in a high temperature electrochemical generator in a single step process. This novel concept promises nearly doubling the conversion efficiency of conventional coal-fired processes and offering near-zero emissions. The improved efficiency would mean that nearly half as much coal is mined and transported to the power plant, and half the greenhouse gases and other pollutants such as sulfur, mercury and dioxins are produced. It also offers several crucial distinctions from conventional coal-burning processes. Since the process does not involve the combustion of coal in air, it does not involve nitrogen and hence generates practically no NOx. Accordingly, there is also no latent heat lost to nitrogen. In this process, the oxygen necessary to oxidize coal is supplied through an ion selective ceramic membrane electrolyte. The resultant product stream primarily consists of CO 2 and, hence, it is easier and cheaper to capture and sequester, compared to waste streams from conventional combustion processes where CO 2 ordinarily constitutes about 15-20% of the flue stream, in which case it may first be separated from other constituents before sequestration.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a multi-head sewing machine having a plurality of heads, more particularly to an improved structure of driving a main shaft and a lower shaft which drive needle bars and thread take-up levers in the respective heads of the multi-head sewing machine.
2. Description of the Related Art
In the multi-head sewing machine, a plurality of heads each having needle bars and thread take-up levers are arranged linearly in the horizontal direction with respect to a machine frame. Meanwhile, on the lower surface of a table in the multi-head sewing machine, a plurality of shuttle holders each having a shuttle accommodated in it are likewise arranged linearly in the horizontal direction. Each shuttle interlocks with the needle bars in the corresponding head.
A common main shaft penetrates the heads to transmit a driving force to the needle bars and thread take-up levers in the respective heads, while a common lower shaft penetrates the shuttle holders to transmit a rotational force to the shuttles in the respective holders. The main shaft and the lower shaft are connected to each other at the end portions via a driving force transmitting mechanism such as a timing belt. Meanwhile, one end portion of the lower shaft is connected to an output shaft of a drive motor directly or via a driving force transmitting mechanism such as a timing belt, so that the lower shaft and the main shaft may be rotated under revolution of the drive motor. While the needle bars and the thread take-up levers in the respective heads are reciprocated by the main shaft, the shuttle in each shuttle holder is rotated by the lower shaft.
In the prior art multi-head sewing machine, the rotational driving force of the drive motor is adapted to be transmitted to the main shaft and the lower shaft at the shaft ends, as described above. Accordingly, a greater load is applied to the main shaft than to the lower shaft, so that the main shaft is distorted much to cause phase deviation among the needle bars, the thread take-up levers and the shuttles in the respective heads depending on the position of the head, and stitch performance is likely to vary among the heads, disadvantageously. Such phenomenon tends to be the more conspicuous, the greater are the number of heads, and thus the longer becomes the length of the main shaft or the lower shaft.
In order to reduce such distortion occurring in the main shaft, a main shaft having a larger diameter may be employed, but the large diameter main shaft penetrating the respective heads inevitably enlarges the mechanism of transmitting driving force to the needle bars and the thread take-up levers in the respective heads (e.g., the diameter of drive cams to be fitted on the main shaft must be enlarged). In such cases, greater vibration occurs during running of the sewing machine, causing another problem that the sewing machine cannot be operated at a high speed.
SUMMARY OF THE INVENTION
The present invention is proposed in view of the problems inherent in the prior art multi-head sewing machine described above and with a view to solving them successfully, and it is an objective of the present invention to further improve the structure of driving the main shaft and the lower shaft which drive the needle bars and the thread take-up levers in the respective heads of the multi-head sewing machine.
In order to solve the problems described above and to attain the intended object successfully, one aspect of the present invention is to provide a multi-head sewing machine comprising a plurality of heads, having at least a needle bar and a thread take-up lever, arranged in a row; a plurality of shuttle holders corresponding to the number of heads, each supporting therein a shuttle, arranged in a row; a main shaft, penetrating the row of heads, which rotates to drive the needle bar and the thread take-up lever in each head; and a lower shaft, penetrating the row of shuttle holders, which rotates to drive the shuttle in each shuttle holder; wherein the sewing machine further comprises a drive shaft, extended parallel to the main shaft, which is rotationally driven by a drive motor, the rotational driving force of the drive shaft being adapted to be transmitted to the main shaft at more than one position.
Likewise, in order to solve the problems described above and to attain the intended object successfully, another aspect of the present invention is to provide a multi-head sewing machine comprising a plurality of heads, having at least a needle bar and a thread take-up lever, arranged in a row; a plurality of shut fie holders corresponding to the number of heads, each supporting therein a shuttle, arranged in a row; a main shaft, penetrating the row of heads, which rotates to drive the needle bar and the thread take-up lever in each head; and a lower shaft, penetrating the row of shuttle holders, which rotates to drive the shuttle in each shuttle holder; wherein a rotational driving force is adapted to be transmitted from a drive motor to the lower shaft or the main shaft substantially at the middle position, and the end portions of the lower shaft are adapted to be connected to the end portions of the main shaft via torque transmitting mechanisms, respectively.
Likewise, in order to solve the problems described above and to attain the intended object successfully, one aspect of the present invention is to provide a multi-head sewing machine comprising a plurality of heads, having at least a needle bar and a thread take-up lever, arranged in a row; a plurality of shuttle holders corresponding to the number of heads, each supporting therein a shuttle, arranged in a row; a main shaft, penetrating the row of heads, which rotates to drive the needle bar and the thread take-up lever in each head; and a lower shaft, penetrating the row of shuttle holders, which rotates to drive the shuttle in each shuttle holder; wherein rotational driving forces are adapted to be transmitted from drive motors to the end portions of the lower shaft or those of the main shaft, respectively; the end portions of the lower shaft are connected to the end portions of the main shaft via torque transmitting mechanisms, respectively; and the drive motors are designed to be driven synchronously.
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 the objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments taken in conjunction with the accompanying drawings in which:
FIG. 1 shows in front view a first embodiment of multi-head sewing machine according to a first aspect of the present invention;
FIG. 2 shows in front view the mechanism for driving the main shaft and the lower shaft in the multi-head sewing machine shown in FIG. 1;
FIG. 3 shows in plan view the mechanism for driving the main shaft and the lower shaft in the multi-head sewing machine shown in FIG. 1;
FIG. 4 is an enlarged cross-sectional view taken along the line A--A in FIG. 3:
FIG. 5 is an enlarged cross-sectional view taken along the line B--B in FIG. 3;
FIG. 6 is an enlarged cross-sectional view taken along the line C--C in FIG. 3;
FIG. 7 shows in front view a second embodiment of the mechanism for driving the main shaft and the lower shaft in the multi-head sewing machine according to the first aspect of the present invention;
FIG. 8 shows in front view a first embodiment of the multi-head sewing machine according to a second aspect of the present invention;
FIG. 9 is an explanatory view of the mechanism for driving the main shaft and the lower shaft in the multi-head sewing machine shown in FIG. 8;
FIG. 10 is an enlarged view of the main shaft coupling structure;
FIG. 11 is an enlarged cross-sectional view of the head and the shuttle holder;
FIG. 12 is an enlarged view of the lower shaft coupling structure in the first embodiment of multi-head sewing machine according to the second aspect of the present invention;
FIG. 13 is an explanatory view of the mechanism for driving the main shaft and the lower shaft in a second embodiment of multi-head sewing machine according to the second aspect of the present invention;
FIG. 14 is an explanatory view of the structure of connecting the drive motor and the main shaft in the second embodiment of multi-head sewing machine according to the second aspect of the present invention;
FIG. 15 is an explanatory view of the structure of driving the main shaft and the lower shaft in a first embodiment of multi-head sewing machine according to a third aspect of the present invention; and
FIG. 16 is an explanatory view of the structure of driving the main shaft and the lower shaft in a second embodiment of multi-head sewing machine according to the third aspect of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(First aspect of the invention)
The multi-head sewing machine according to the present invention will be described below by way of preferred embodiments referring to the attached drawings. First, FIGS. 1 to 6 show a first preferred embodiment according to a first aspect of the present invention, in which eight heads 3 are arranged in a row at equal intervals on the front surface of an upper frame 2 located horizontally above a table 1 (see FIG. 1). Meanwhile, shuttle holders 6 are arranged in a row on the upper surface of a lower frame 5 located below the table 1 to oppose the corresponding heads 3, respectively (see FIG. 2).
As shown in FIG. 6, each head 3 consists of an arm 7 fixed on the front surface of the upper frame 2 and a needle bar case 8 supported on the front surface of the arm 7 to be slidable crosswise. A needle bar driving mechanism 10 and a thread take-up lever driving mechanism 11 are incorporated into each arm 7, whereas a plurality of (six in this embodiment) needle bars 12 and a corresponding number of thread take-up levers 13 are supported in each needle bar case 8. Further, in each shuttle holder 6, a shuttle 15 which interlocks with needles 14 attached to the lower end portions of the needle bars 12 is secured to the front end of a shuttle shaft 16 rotatably supported by the shuttle holder 6. A driven gear 17 is attached to the rear end of this shuttle shaft 16.
As shown in FIGS. 1 to 3, main in shafts 20a and 20b penetrate a group of four arms 7 located on the left side and a group of four arms 7 located on the right side, relative to the center of the multi-head sewing machine, respectively, and these shafts 20a,20b are supported rotatably by bearings (not shown) provided on the side walls of the arms 7. A needle bar driving cam 10a constituting the needle bar driving mechanism 10 and a thread take-up lever driving cam 11a constituting the thread take-up lever driving mechanism 11 are fitted on the main shafts 20a(20b ) within each arm 7. Drive shafts 21a,21b having a diameter greater than that of the main shafts 20a,20b are disposed to parallely oppose mainshafts 20a,20b on the rear side of the upper frame 2. The left drive shaft 21a and the fight drive shaft 21b are rotatably supported by bearings 22,23,24 and bearings 25,26, fixed on the rear surface of the upper frame 2, respectively. A double-ended drive motor 27 is fixed on the rear surface of the upper frame 2 between the drive shafts 21a and 21b, and the right end of the drive shaft 21a and the left end of the drive shaft 21b are connected to the left end of a motor shaft 27a and to the right end of a motor shaft 27b via couplings 28, respectively.
Timing pulleys 30 are fitted on the main shafts 20a,20b at the middle positions, respectively, and timing pulleys 31 are fitted on the drive shafts 21a,21b to oppose the timing pulleys 30, respectively. Timing belts 32, penetrating the upper frame 2 through windows 2a (see FIG. 5) defined in the front wall and the rear wall of the frame 2, are wrapped around the opposing pairs of timing pulleys 30,31, respectively. The timing pulley 31 attached to the drive shaft 21a and the timing pulley 31 attached to the drive shaft 21b are adapted to locate at the same distance from the drive motor 27.
A lower shaft 33 penetrates the shuttle holders 6 and is rotatably supported by bearings (not shown) provided on the side walls of the shuttle holders 6. A drive gear 34 is fitted on the lower shaft 33 to be meshed with the driven gear 17 within each shuttle holder 6. The left end of the lower shaft 33 is supported by a bearing 35, and a timing pulley 36 is fitted on the left end portion of the shaft 33. Another timing pulley 37 is fitted to the left end portion of the drive shaft 21a to oppose the pulley 36. A timing belt 38 is wrapped around these timing pulleys 36,37 with tension rollers 40,41 being disposed between them.
Next, actions of the thus constituted embodiment will be described. When the drive motor 27 is first started to rotate the drive shafts 21a,21b in the same direction, the main shafts 20a,20b are rotated via the timing belts 32, and thus the needle bars 12 and the thread take-up levers 13 are reciprocated vertically via the needle bar driving mechanisms 10 and the thread take-up lever driving mechanisms 11 in the respective head. The lower shaft 33 is also rotated via the timing belt 38 to rotationally drive the shuttles 15 via the drive gears 34 and the driven gears 17, respectively. Accordingly, the needle bars 12, the thread take-up levers 13 and the shuttles 15 in the respective heads 3 are synchronously driven in predetermined phases, respectively. It should be noted here that in this embodiment, the main shaft is divided into two shorter parts (20a,20b) which are allotted to the right and left head groups of four respectively, so that the rotational driving force may be applied to the middle portions of the main shafts 20a,20b, and thus distortion which is likely to occur in the main shafts 20,20b can be reduced, advantageously.
In this embodiment, since the rotational driving force of the drive motor 27 is designed to be transmitted to the drive shafts 21a,21b at the middle between the timing pulleys 31, the drive shaft 21a and the drive shaft 21b are leveled in the quantity of distortion which is likely to occur at the locations of the timing pulleys 31. Accordingly, the main shafts 20a,20b rotate in the same phase, and the needle bars 12, the thread take-up levers 13 and the shuttles 15 in the respective heads 3 can be driven substantially in the same phases, respectively. More specifically, there occurs no inconvenience that stitch performance becomes irregular depending on the position of the head 3. While the drive motor 27 is disposed between the timing pulleys 31 fitted on the respective drive shafts 21a,21b in this embodiment, the drive motor 27 is preferably positioned a little to the left taking it into consideration that the drive shaft 21a is distorted by the reactive force applied by the lower shaft 33 via the timing belt 38.
Next, a second embodiment according to the first aspect of the present invention will be described referring to FIG. 7. In the second embodiment, rotational driving force of a drive motor 51 is adapted to be transmitted to a shaft end of a drive shaft 50. It should be noted here that the same or similar parts as in the first embodiment are affixed with the same reference numbers respectively, and detailed description of them shall be omitted. The drive shaft 50, the diameter of which is greater than that of the main shafts 20a,20b, is located above the main shafts 20a,20b parallel to them and is rotatably supported by bearings 52,53,54 fixed on the front surface of the upper frame 2. A timing belt 57 is wrapped around a timing pulley 55 fitted to the drive shaft 50 adjacent to the bearing 54 and a timing pulley 56 fitted to the lower shaft 33 to oppose the timing pulley 55. The drive motor 51 is fixed on the front surface of the upper frame 2 below the left end portion of the drive shaft 50, and a timing belt 60 is wrapped around a timing pulley 58 fitted on the motor shaft and a timing pulley 59 fitted to the drive shaft 50 to oppose the timing pulley 58. A pair of timing pulleys 61 are fitted on the drive shaft 50 to oppose the timing pulleys 30 fitted at the middle of the main shafts 20a,20b, respectively, and a timing belt 62 is wrapped around each opposing pair of timing pulleys 61,30. In the multi-head sewing machine according to the second embodiment, when the drive motor 51 is started to rotate the drive shaft 50 in a certain direction, the main shafts 20a,20b are rotated via the timing belts 62, and the lower shaft 33 is also rotated via the timing belt 57 to drive the needle bars 12, the thread take-up levers 13 and the shuttles 15 in the respective heads 3 synchronously in predetermined phases, respectively. Since the main shaft is divided into two shorter parts (20a,20b) which are allotted to the right and left head groups of four respectively so that the rotational driving force may be transmitted to the middle portions of the respective main shafts 20a,20b, distortion which is likely to occur in the main shafts 20,20b can be reduced like in the first embodiment. Further, since the rotational driving force of the drive motor 51 is adapted to be transmitted to a shaft end of the drive shaft 50, the drive shaft 50 is distorted more than in the first embodiment. However, by allowing the drive shaft 50 to have a diameter large enough to control such distortion to a tolerable range, the main shafts 20a,20b can be rotated in the same phase like in the first embodiment. Accordingly, in all of the heads 3, the needle bars 12, the thread take-up levers 13 and the shuttles 15 are driven substantially in the same phases respectively, and there occurs no inconvenience that stitch performance becomes irregular depending on the position of the head 3.
(Second aspect of the invention)
FIGS. 8 to 12 shows a first preferred embodiment according to a second aspect of the present invention, in which a plurality of heads 3 are arranged at equal intervals on the front surface of an upper frame 42 located horizontally above a table 1 (see FIG. 8). Shuttle holders 6 are arranged in a row on a lower frame 81 to oppose the heads 3 respectively (see FIG. 9).
As shown in FIG. 11, each head 3 consists of an arm 43 fixed to the front surface of the upper frame 42 and a needle bar case 44 supported on the front surface of the arm 43 to be slidable crosswise. A needle bar driving mechanism 45 and a thread take-up lever driving mechanism 46 are incorporated into each arm 43, whereas a plurality of (six in this embodiment) needle bars 12 and a corresponding number of thread take-up levers 13 are supported in each needle bar case 44. Further, a shuttle 15, which interlocks with needles 14 attached to the lower end portions of the needle bars 12, is secured to the front end of a shuttle shaft 47. A driven gear 48 is attached to the rear end of this shuttle shaft 47.
As shown in FIG. 9, main shafts 49a and 49b penetrate a group of arms 43 located on the left side and a group of arms 43 located on the right side, relative to the center of the multi-head sewing machine, respectively, and they are supported rotatably by bearings (not shown) provided on the respective arms 43. These main shafts 49a,49b are connected to each other via a coupling 50. Large diameter shafts 51a,51b are integrally connected to the left end of the left main shaft 49a and the right end of the right main shaft 49b via couplings 80 respectively (see FIG. 10), and these shafts 51a,51b are supported at the free end portions by bearings 52 fixed to the machine frame, respectively. Timing pulleys 53 of the same diameter are fitted to the end portions of the large diameter shafts 51a,51b adjacent to the bearings 52, respectively.
Meanwhile, as shown in FIG. 8, lower shafts 54a,54b penetrate the group of shuttle holders 6 locating on the left side and the group of shuttle holders 6 locating on the right side, relative to the center of the multi-head sewing machine, and these shafts 54a,54b are rotatably supported by bearings (not shown) provided on the respective shuttle holders 6. Further, as shown in FIG. 9, a large diameter shaft 57 is supported by bearings 56 fixed to the lower frame 81 and is connected to the inner ends of the lower shafts 54a54b via couplings 58, respectively. A timing pulley 59 is fitted on the large diameter shaft 57 at the middle, and another timing pulley 62 is fitted to a motor shaft 61 of a drive motor 60 fixed to a lower machine frame. A timing belt 63 is wrapped around the timing pulley 59 of the large diameter shaft 57 and the timing pulley 62 of the drive motor 60.
The left end of the lower shaft 54a locating on the left side in FIG. 9 is integrally connected to a large diameter shaft 64a via a coupling 65, and the right end of the lower shaft 54b locating on the right side is integrally connected to a large diameter shaft 64b via a coupling 65, as shown in FIG. 10. As shown in FIG. 9, these large diameter shafts 64a,64b are supported at the free ends by bearings 66 fixed on the machine frame, respectively. Timing pulleys 67 of the same diameter are attached to the end portions of the large diameter shafts 64a,64b adjacent to the bearings, respectively. A timing belt 68 is wrapped around the timing pulley 67 and a timing pulley 53 attached to the large diameter shaft 51a(51b). As shown in FIG. 11, drive cams 69 and 70 constituting the needle bar driving mechanism 45 and the thread take-up lever driving mechanism 46 located in each arm 43 are fitted on the main shaft 49a(49b) shown in FIG. 9. Further, a drive gear 71 is fixed to the lower shafts 54a(54b) within each shuttle holder 6 shown in FIG. 11 to be meshed with the driven gear 48 of the shuttle shaft 47.
In the first embodiment of the multi-head sewing machine according to the second aspect of the present invention described above, when the drive motor 60 is driven to rotate in a certain direction, the lower shafts 54a54b are rotated via the center timing belt 63, and also the main shafts 49a,49b are rotated via the side timing belts 68. Thus, the needle bars 12, the thread take-up levers 13 and the shuttles 15 in the respective heads 3 are driven synchronously. In this first embodiment, since the rotational driving force of the drive motor 60 is adapted to be transmitted to the middle portions of the left and right lower shafts 54a54b respectively, distortion which is likely to occur in the lower shafts 54a54b becomes smaller than in the prior art multi-head sewing machine. Meanwhile, since the rotational driving force is transmitted to the main shafts 49a,49b respectively, distortion which is likely to occur in the main shafts 49a,49b also becomes smaller than in the prior art multi-head sewing machine. Accordingly, the phases of the needle bars 12, the thread take-up levers 13 and the shuttles 15 do not vary depending on the position of the head 3 to enable stitching such as embroidering properly. Further, in this embodiment: (1) the lower shafts 54a54b are connected to each other via the large diameter shaft 57; (2) the large diameter shafts 51a,51b are attached to the outer ends of the main shafts 49a,49b, respectively; and (3) the large diameter shafts 64a,64b are attached to the outer ends of the lower shafts 54a,54b, respectively. Accordingly, distortion which is likely to occur in the main shafts 49a,49b and in the lower shafts 54a,54b can be further controlled, advantageously. While the main shafts 49a,49b are connected to each other via the coupling 50 in this embodiment, they may not be connected to each other in some cases.
Next, a second embodiment according to the second aspect of the present invention will be described below. The difference between the first embodiment and the second embodiment is that the rotational driving force of the drive motor 60 is adapted to be transmitted to the lower shafts 54a,54b, respectively, in the first embodiment, whereas the rotational driving force of the motor 60 is adapted to be transmitted to the main shafts 49a,49b, respectively, in the second embodiment. In FIG. 13, a large diameter shaft 74 is supported by bearings 73 fixed on the front surface of an upper frame 42 between the inner ends of the main shafts 49a,49b which locate at the center of the sewing machine, and the inner ends of the main shafts 49a,49b are connected to the large diameter shaft 74 via couplings 75, respectively. A timing pulley 76 is fitted to the center of the large diameter shaft 74, and another timing pulley 62 is fitted on a motor shaft 61 of the drive motor 60 fixed to the rear surface of the upper frame 42 (see FIG. 14). A timing belt 63, penetrating the upper frame 42 through windows 77 (see FIG. 5) defined in the front wall and the rear wall of the frame 42 respectively, is wrapped around the timing pulley 62 and the timing pulley 76 of the large diameter shaft 74. The lower shafts 54a54b are connected to each other via a coupling 78.
In this second embodiment, when the drive motor 60 is driven to rotate in a certain direction, the main shafts 49a,49b are rotated via the center timing belt 63. Since the lower shafts 54a54b are also rotated via the side timing belts 68, the needle bars 12, the thread take-up levers 13 and the shuttles 15 in the respective heads 3 are driven synchronously. Since the rotational driving force of the drive motor 60 is adapted to be transmitted to the middle portions of the left and right main shafts 49a,49b in the second embodiment, distortion which is likely to occur in the main shafts 49a,49b becomes smaller than in the prior art multi-head sewing machine. In addition, since the rotational driving force is further transmitted via the main shafts 49a,49b to the respective lower shafts 54a,54b, distortion which is likely to occur in the lower shafts 54a,54b also becomes smaller than in the prior art multi-head sewing machine. Accordingly, the phases of the needle bars 12, the thread take-up levers 13 and the shuttles 15 in the heads 3 do not vary depending on the position of the head 3 to enable stitching such as embroidering properly. While the lower shafts 54a54b are connected to each other via the coupling 78 in the second embodiment, they may not be connected to each other in some cases.
(Third aspect of the invention)
FIG. 15 shows a first embodiment according to a third aspect of the present invention, in which rotational driving forces of two drive motors 60 provided with respect to the left and right lower shafts 54a54b are adapted to be transmitted to these shafts 54a,54b, respectively. More specifically, in FIG. 15, the main shafts 49a,49b are connected to each other via a coupling 82, whereas the lower shafts 54a54b are connected to each other via another coupling 82. Timing pulleys 83 of the same diameter are fitted on the lower shafts 54a,54b adjacent to the timing pulleys 67, respectively. The drive motors 60 are mounted on the machine frame below the timing pulleys 83, respectively. A timing belt 63 is wrapped around each opposing pair of timing pulleys, i.e. the timing pulley 62 attached to the motor shaft 61 and the timing pulley 83 attached to the large diameter shaft 64a(64b). These two drive motors 60 are adapted to be driven in the same direction synchronously. In this first embodiment again, distortion which is likely to occur in the main shafts 49a,49b and in the lower shafts 54a54b becomes smaller than in the prior art multi-head sewing machine. Incidentally, the main shafts 49a,49b may not be connected to each other in some cases again in this embodiment.
FIG. 16 shows a second embodiment according to the third aspect of the present invention, in which rotational driving forces of drive motors 60 are adapted to be transmitted to both of the left and right main shafts 49a,49b. More specifically, in FIG. 16, the main shafts 49a,49b are connected to each other via a coupling 82, whereas the lower shafts 54a54b are connected to each other via another coupling 82. Timing pulleys 84 of the same diameter and timing pulleys 53 of the same diameter are fitted on the main shafts 49a,49b adjacent to each other, respectively. The drive motors 60 are mounted on the rear surface of the upper frame 79 behind the timing pulleys 53, respectively, like in the first embodiment (see FIG. 14). A timing belt 63 is wrapped around each opposing pair of timing pulleys, i.e. the timing pulley 62 attached to the motor shaft 61 and the timing pulley 53. These two drive motors 60 are adapted to be driven in the same direction synchronously. In this second embodiment again, distortion which is likely to occur in the main shafts 49a,49b and in the lower shafts 54a54b becomes smaller than in the prior art multi-head sewing machine. Incidentally, the lower shafts 54a54b may not be connected to each other in some cases again in this embodiment.
As has been described heretofore, according to the multi-head sewing machine of the present invention, the phenomenon that the phases of the needle bars, the thread take-up levers and the shuttles vary greatly depending on the position of the head can be avoided, so that all of the heads exhibit uniform stitch performance to effectively achieve stitching such as embroidering properly. Meanwhile, there is no need of allowing a large-diameter main shaft to penetrate each head or of employing a main shaft and a lower shaft having large diameters, enabling high-speed operation of the multi-head sewing machine with low vibration, without enlarging the needle bar driving mechanism or the thread take-up lever driving mechanism.
Although only a few 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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Disclosed is a multi-head sewing machine having an improved structure for driving a main shaft and a lower shaft for driving needle bars and thread take-up levers so as to prevent distortion of these shafts, in turn, variation of stitch performance in the respective heads from occurring. The sewing machine comprises a plurality of heads, having at least a needle bar and a thread take-up lever, arranged in a row; a plurality of shuttle holders corresponding to the number of heads, each supporting therein a shuttle, arranged in a row; a main shaft, penetrating the row of heads, which rotates to drive the needle bar and the thread take-up lever in each head; and a lower shaft, penetrating the row of shuttle holders, which rotates to drive the shuttle in each shuttle holder; wherein the sewing machine further comprises a drive shaft, extended parallel to the main shaft, which is rotationally driven by a drive motor, the rotational driving force of the drive shaft being adapted to be transmitted to the main shaft at more than one position.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of allowed U.S. application Ser. No. 11/067,729 filed Mar. 1, 2005, which issued as U.S. Pat. No. 8,105,284. The entire disclosure, including the drawings, of the prior application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to medical instruments and in particular a system that establishes percutaneous access to a blood vessel or body cavity (which would include an abscess or pleural or peritoneal or pericardial or epidural or subarachnoid spaces).
2. Related Art
It is frequently necessary to establish access to an internal portion of the body for the purpose of removal of fluid, administration of medication, establishing a drainage path and the like. A typical application is placement of a catheter in a blood vessel for collection of blood over an extended period of time. This same catheter can be used for the intravenous administration of drugs and anesthesia. Delivery is not limited to vascular access but also for establishing caudal and lumber epidural blocks for the production of local or regional anesthesia by infiltration techniques. Another common use for catheter placement is to establish a drainage path for the pleural or peritoneal or pericardial spaces or from a surgery site or abscess.
As used herein, the term โproximal endโ refers to that portion of the system that is above the skin line and is accessible. The term โdistal endโ refers to that portion of the system that is inserted into the body, such as the tip of the needle or end of the catheter.
A typical procedure involves the placement of a catheter, typically flexible and of a plastic material, into the space occupied area with the proximal end affixed at skin level. A thorocentesis kit may be used which employs a needle with a catheter mounted concentrically on the outside. The length of the needle is somewhat longer that the catheter so that the sharp tapered end projects beyond the end of the catheter. The outer end of the catheter is tapered to provide a smooth transition from the outer diameter of the needle to that of the catheter. The inner end of the catheter is sleeved with a connector for subsequent connection to a collection bag, syringe or cut-off valve. A syringe is attached to the end of the needle. The catheter is then free to slide on the outside of the needle but is prevented from coming off the needle at the proximal end by the attachment connector of the needle to the syringe.
In this procedure the needle pierces the skin and any underlying tissue carrying with it the catheter. Since the proximal end of the catheter is stopped by the syringe attachment, it advances at the same rate as the needle. Once a sufficient depth of penetration is achieved by the needle, the clinician simultaneously withdraws the needle while advancing the catheter. The needle acts as a guide for the catheter. Generally accumulation of a small amount of fluid in the syringe provides an indication that the needle has penetrated to the destination location. The catheter is advanced until its distal end is at the desired location and then the needle is totally withdrawn. The proximal end of catheter may then be attached to a collection bag for drainage or collection of bodily fluid. It may also be used as a port for the delivery of medicine by subsequent introduction of a needle with a syringe loaded with a drug. The catheter proximal end can also be fitted with a valve for capping the catheter.
One disadvantage of this technique is that the fact that the catheter-flow circuit must be broken in order to remove the introducer needle as the needle is removed the catheter is in open fluid communication with the environment so that air can enter into the cavity if the pressure gradient favors retrograde flow. Another disadvantage of this technique includes the possibility of an unintended needle stick of the clinician upon his or her withdrawal of the needle because of the technique and materials used in the above described system. Yet another disadvantage of this prior art technique is that the needle must be as long as the catheter making it cumbersome to handle and manipulate.
Another technique in use employs a large diameter needle that is used to establish access to the body location where the catheter will be placed. A wire is then passed inside the needle until it has reached the approximate location at or beyond the distal end of the needle. The needle is then withdrawn and the wire remains. A catheter is then slid over the wire as the wire is removed and the catheter remains behind. A problem with this technique involves the number of steps required each of which individually and collectively add levels of potential complications and/or inaccurate distal catheter placement. Frequently, the distal end of the catheter will abut or sometimes dig into the wall of the vessel preventing the withdrawal or delivery of fluid.
SUMMARY OF INVENTION
Given the disadvantages of the prior art, an object of this invention is to provide a system providing reliable access and placement of a catheter into a bodily cavity, an organ, or blood vessel.
Another object of this invention is to provide a medical procedure involving a method of catheter placement that is reliable and safer than prior art allows which includes a system that maintains a closed circuit from the beginning to the end of the procedure.
Yet another object of this invention is to provide a percutaneous kit for intra-vascular or intra-cavitary catheter placement for the administration of drugs and/or evacuation of fluid.
These and other objects of this invention are accomplished by means of a needle/catheter combination with a beveled introducer needle able to slide over the catheter. The catheter is longer than the needle. The outer diameter of the catheter is substantially equal to the internal diameter of the needle to permit sliding movement over the catheter. The introducer needle has a longitudinal slit running its entire length and a flange at the distal end with a knurled grip. The slit defines an open groove running the length of the needle.
The catheter has a connector section at the proximal end for attachment of a syringe or valve. The connector has a section of reduced size in a grooved shape whose thickness is equal to the width of the longitudinal slit in the introducer needle. This groove will therefore permit the needle to pass over it. In one embodiment the connector section is oriented at an angle to the catheter and the reduced section is on the connector portion and oriented in alignment with the groove which enables the needle to align with the groove in a seamless manner. In another embodiment, the connector is positioned axially at the proximal end of the catheter and the section of reduced size is an elongated region of reduced cross-sectional size above the connector.
Another aspect of this invention is the provision of a single directional dual ball suction/delivery valve for the collection of fluid. The valve has three ports, an output port with a valve attached to the catheter, an input valve port coupled to a collection bag and a port in fluid communication with both valves connected to a source of reduced pressure such as a syringe. When suction is created by the syringe the valve ball moves toward a limiting post opening the orifice emptying the proximal catheter lumen while simultaneously causing a second ball to seal the orifice of the catheter conducting material to a collection receptacle. When positive pressure is applied by the syringe the first ball is caused to seal closed the orifice to the proximal end of the introduced catheter and simultaneously causing the second ball to move away from the orifice to the catheter communicating material to the collection receptacle with the ball being stopped by a limiting post.
In operation of the system, the clinician holds the introducer needle by one hand and stabilizes the catheter with the other hand. The catheter is positioned inside the needle and slightly behind the beveled distal end. The needle punctures the skin and underlying tissue to a desired depth of penetration. The catheter is then advanced and the needle withdrawn by sliding the needle over the catheter as the catheter is advanced. When the proximal end of the needle, with the flange, reaches the connector section (or area of reduced cross-section) it is stripped off the catheter along the longitudinal groove. As an alternative to complete removal of the needle, it can be docked on the catheter for later removal but the danger in the delay of removal is that it potentially exposes an individual to the contents of the space entered and adds the risk for catheter puncture or shearing by the introducer needle tip (if mishandled). A syringe and/or a valve are attached to the connector before the procedure begins.
These and other aspects of this invention will become apparent from the drawings and the description of the preferred embodiments that follow.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a first preferred embodiment of this invention illustrating the components thereof;
FIG. 2 is a perspective view of a second preferred embodiment of this invention illustrating the components thereof;
FIG. 3 is a schematic view of the valve used in accordance with this invention, and
FIG. 4 is a schematic view illustrating the method of use of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 a schematic perspective view illustrates the essential components of this invention. The kit 10 comprises three components, a catheter 12 , an introducer needle 14 and a syringe body 16 . The syringe 16 is conventional and need not be discussed further.
The catheter 12 is typically an elongated hollow plastic tube of suitable internal diameter and stiffness. The distal end 18 is beveled and tapered to aid in penetration. The bevel matches that of the needle. The proximal end has a connector section 20 . In this preferred embodiment the connector section 20 is oriented 90ยฐ to the axis of the catheter via an elbow portion. It is apparent that the connector section 20 need not be at right angles to the axis of the connector. This section has a flange 22 and a hole 24 into which the syringe 16 is inserted. It is apparent that a valved โYโ connector can also be attached at this point instead of the syringe.
The connector has a flattened section 26 which is aligned with the longitudinal axis of the catheter that is parallel to the internal bore of the catheter. The outer thickness of the section 26 matches the width of the slit of the introducer needle, as will be explained herein.
The introducer needle 14 is metal or rigid plastic. It has a distal end that is sharpened and beveled. The proximal end has a holding flange 30 . This is in the form of a tab portion suitably roughened by knurling or the like to provide a secure thumb and finger grip. Preferably the tab portion is wrapped around the needle to provide two protruding ends.
The introducer needle has a longitudinal groove or slit running the length of the needle. As illustrated the needle circumference is about 270ยฐ with the groove comprising about 90ยฐ. The exact angular extent of the wrap around of the needle 14 vis-ร -vis the catheter 12 is not critical so long as the needle is held in position on the catheter, that is, a coaxial relationship is maintained during the placement phase of the procedure. The groove may be as large as slightly less than 180ยฐ in the case of a relatively stiff and/or large diameter catheter where in either case the catheter will support the needle. It may alternatively be relatively thin in the case of flexible catheter requiring a greater degree of support about its circumference.
The elongated groove or slit may have a circumference in the range of greater than 0 degrees to slightly less than 180 degrees adapted to slide over the reduced cross-section portion of the catheter to separate the introducer needle from the catheter.
A second preferred embodiment is illustrated in FIG. 2 . Like elements are identified with the same numbering as in FIG. 1 and need not be discussed. In this embodiment, the catheter 12 has two sections, a full diameter portion 34 and a reduced diameter portion 36 . The introducer needle 14 is mounted on the full diameter portion 34 and is slidable as in the first preferred embodiment. The reduced diameter portion 36 is used to remove the needle from the catheter, as will be described herein. While the connector is illustrated as coaxial with the catheter, it is apparent that it could be angled as in the first preferred embodiment.
The operation of the invention will now be described. In the FIG. 1 embodiment the catheter 12 and the introducer needle 14 are either pre-assembled as illustrated in the figure or the needle is slid over the distal end of the catheter. The distal ends of the needle and catheter are aligned so that the bevels 18 and 28 co-incident with each other. The clinician then holds the catheter in one hand by the knurled portions of the needle flanges and the tab 30 with the other. The assembled needle 14 and catheter 12 are then percutaneously inserted intra-vascular or intra-cavitary to a proximal position. Then, holding the needle in a stationary position, the catheter is advanced to the desired placement position. As such, the needle moves relatively backward toward the proximal end that is closer to the connector 20 .
With the catheter in its proper position, the needle is fully retracted by a sliding movement using the tab 30 . When the tab reaches the connector 22 , the tab portions 30 are either spread apart or peeled back to a position opposite the slit 32 . The needle then passes over the connector with the slit riding over the reduced cross-sectional portion 26 . As such the needle is removed and can be discarded by merely holding it and moving the needle with the tabs 30 . This is illustrated in FIG. 4 . Alternatively, the needle 14 may be โdockedโ, that is left in position adjacent the connector for removal at a later date.
In the case of the embodiment of FIG. 2 , the introducer needle 14 is slid down the length of the catheter until it reaches the reduced diameter portion 36 . The tabs are then reversed and the needle stripped off the catheter. As in the FIG. 1 embodiment, the needle may be docked over the reduced section but again the risks related to delayed needle removal include catheter puncture or shearing by the introducer needle tip if mishandled.
In both embodiments the syringe 16 or a stop valve, not illustrated, can be attached to the catheter at any point in the procedure. That is, it may be affixed to the connector 20 before the needle is introduced or after the needle is stripped off, or at any time in between. The syringe can be used for the introduction of medicine or as a space occupied evacuation system.
It will be appreciated that by this combination of introducer needle and catheter achieves accurate percutaneous placement of a catheter and yet the needle can be easily withdrawn and safely removed without disturbing the catheter or forcing a break in the collection circuit.
A valve for use with this system is illustrated in FIG. 3 . The valve 40 has a hollow body portion 42 with three ports 44 , 46 and 48 . The body portion 42 has an internal wall 60 with a pair of thru-holes 62 , 64 . Port 44 is an open conduit to be attached to a source of reduced pressure such as suction or, as illustrated, syringe 16 . Two stop elements 50 , 52 are positioned in ports 46 and 48 respectively. The stop elements each have a stopper 54 and a guide 56 . The stoppers 54 are sized to seal either the port 46 and prevent backflow into port 46 or opening 64 . The stop elements are reversed, as shown, so that port 46 constitutes and โINโ and port 48 an โOUTโ.
The port 46 is typically connected to the catheter 12 via the connector 20 . The port 48 is attached to a collection bag, not illustrated. In operation with these components attached, when the syringe piston is withdrawn pressure within the body 42 is reduced causing stopper elements 50 and 52 to move toward and seat on the wall 60 . In this position, fluid communication is established between catheter 12 and hollow body portion 42 while the stopper 54 seals the OUTPUT 48 . By the application of further suction by action of the syringe, the body 42 and potentially the syringe body 16 will fill with fluid. When the piston is advanced, the stoppers 50 and 52 move toward the ports 46 and 48 . This seals the INPUT 46 and opens the OUTPUT 48 allowing the fluid to be collected in the collection bag.
It will be appreciated that if the source of suction coupled to port 44 is another source, such as a continuous vacuum, the material collected can be immediately and directly removed.
It is apparent that alternatives of these embodiments are within the scope of this invention. For example, the cross section of the needle and catheter need not be round. It can be configured to any cross-sectional shape desired as a function of the procedure, such as oval, triangular or the like. The tab on the introducer needle does not have to be knurled to provide a grip. It may be perforated, corrugated, roughened by other techniques or made sticky to tactile grip. The tab may be modified to be a fixed protrusion on the needle at a position that does not block the groove.
The dimensions of the longitudinal groove and the geometry are functions of the materials used and the diameter of the catheter. In the case of a relatively thin and/or flexible catheter the groove may be thin and still allow the needle to be stripped off. If the catheter is relatively stiff, the groove may be larger, approaching one-half the circumference of the needle yet the needle will still be held on the catheter but easily stripped off. Although not illustrated, the groove may have a wider circumferential portion at the proximal end to facilitate the stripping process by โstartingโ the needle off of the catheter.
Additionally the connector section can have a stop valve attached or made integral to it to prevent fluid communication between the catheter and ambient conditions.
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An assembly and method for percutaneous placement of a catheter comprising an elongated hollow catheter having a distal end and a reduced cross-section portion at a proximal end thereof. An introducer needle is slidably mounted over said catheter. The introducer needle has an elongated slit adapted to slide over the reduced cross-section portion to separate the needle from the catheter. A syringe may be attached to the proximal end of the catheter. Also, a valve may be attached to the catheter to permit easy collection of fluid.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application, a concurrently filed application in the names of James R. Kuo and Maggie Leung, entitled "Integrated Circuit Power Transistor Array", and a concurrently filed application by James R. Kuo, entitled, "Integrated Circuit Potential Reducing Technique", are directed to related inventions.
FIELD OF THE INVENTION
This invention relates to an improved temperature compensated reference voltage circuit. More particularly, this invention relates to a circuit for controlling supply voltage to a load element, which incorporates the improved temperature-compensated reference voltage circuit. Most especially, this invention relates to a sense amplifier circuit which will provide outputs to at least two different load circuit elements, depending on the level of a supply voltage.
DESCRIPTION OF THE PRIOR ART
There are a variety of circuits known in the art for providing predetermined reference voltages. For example, the well-known diode drop reference voltage circuit employs, for example, two serially connected diodes to establish a predetermined reference voltage, but that reference voltage is not temperature-compensated. Particularly in the case of integrated circuits which are designed to provide power inputs to a load, the operating temperatures of the circuit vary as the circuit is used. In such circuits, it is especially important that critical reference voltages be temperature-compensated.
Recognizing the need for temperature-compensated reference voltage circuits, the Widlar band-gap reference voltage circuit provides a temperature-compensated voltage reference at the silicon band-gap voltage of 1.31 volts. The Widlar band-gap reference voltage circuit is described in, for example, Widlar, "New Developments in IC Voltage Regulators", IEEE Journal of Solid State Circuits, February 1971, Vol. SC-6, No. 1, pp. 2-7. However, the Widlar band-gap reference voltage circuit is frequency sensitive. As a result, it is necessary to provide a fairly large metal-oxide-semiconductor (MOS) capacitor in the Widlar band-gap reference circuit in order to compensate for different frequencies that may be encountered in the use of the circuit.
A particularly demanding application for an integrated circuit supplying power signals to load elements is for driving thermal printhead elements. Such thermal printhead elements must each operate rapidly and in an identical manner to provide printing of uniform characters at an acceptable speed. Thus, control circuits for the operation of power transistors in such integrated circuits must supply their control signals in a uniform manner, independent of temperature and signal frequency variations in use of the circuits. While the design of control circuits for such power transistor arrays is a highly sophisticated art, a need still remains for further improvement in such control circuits.
SUMMARY OF THE INVENTION
Accordingly, it is an object of this invention to provide a temperature-compensated reference voltage circuit which is frequency independent, without the use of frequency compensation.
It is another object of this invention to provide a temperature-compensated reference voltage circuit which does not require the use of capacitive elements for frequency compensation.
It is still another object of the invention to provide a circuit for controlling supply voltage to a load element that incorporates such a temperature-compensated reference voltage circuit.
It is still another object of the invention to provide a sense amplifier circuit which provides outputs to at least two different circuit elements, depending on level of a supply voltage, and which incorporates such a temperature-compensated reference voltage circuit.
The attainment of these and related objects may be achieved through use of the novel temperature-compensated reference voltage circuit and sense amplifier circuit of this invention. The temperature-compensated reference voltage circuit of this invention includes a transistor having a positive temperature coefficient of current, desirably a PNP lateral transistor. There is means for establishing a predetermined current in the positive-temperature-coefficient-of-current transistor, which current establishing means is connected to that transistor. The circuit includes a transistor having a negative temperature coefficient of base-to-emitter voltage desirably a NPN vertical transistor. There is a predetermined resistance serially connecting the two transistors. The temperature-compensated reference voltage is therefore establised between the two transistors.
A supply voltage sense amplifier circuit in accordance with this invention includes the temperature-compensated reference voltage circuit as described above. A means is connected to receive the reference voltage for comparing the reference voltage and a supply voltage. An output is adapted to be connected to a load for receiving the supply voltage. A means is connected to receive an input from the comparing means and to the output, for enabling the output when the supply voltage has a predetermined relationship relative to the reference voltage. Typically, the relationship is when the supply voltage equals or exceeds the reference voltage at the point of measurement.
In a preferred embodiment of the sense amplifier circuit, there are alternative outputs, each controlled by at least one output transistor. The supply voltage is furnished at one output when the supply voltage is less than the reference voltage, and the supply voltage is supplied to another output when the supply voltage is equal to or greater than the reference voltage.
A supply voltage sense amplifier circuit incorporating the temperature-compensated reference voltage circuit of this invention provides control signals to a load element connected to the output of the circuit, such as a thermal printhead element. The supply voltage remains at a constant level, independent of frequency and temperature variations of an integrated circuit, including the sense amplifier. While these characteristics make the sense amplifier circuit of special value for controlling drive signals for thermal printhead elements, the circuit can be used for a wide variety of other applications.
The attainment of the foregoing and related objects, advantages and features of the invention should be more readily apparent to those skilled in the art after review of the following more detailed description of the invention, taken together with the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an integrated circuit incorporating the invention;
FIG. 2 is a circuit schematic of an embodiment of the invention, as implemented in the integrated circuit of FIG. 1;
FIG. 3 is a waveform diagram useful for understanding operation of the circuit in FIG. 2;
FIG. 4 is a circuit schematic diagram of another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, more particularly to FIG. 1, there is shown a block diagram of a thermal printhead driver integrated circuit incorporating the invention. A +VCC supply sense amplifier circuit 10 in accordance with the invention has outputs connected by lines 12, 14, 16 and 18 to multiplexing gates 20, 6-bit storage register 22 and 6-bit serial in, parallel out shift register 24. Lines 26 connect the 6-bit storage register 22 to multiplexing gates 20. Lines 28 connect the 6-bit storage register 22 to the 6-bit serial in, parallel out shift register 24. Lines 30 connect the multiplexing gates 20 to open collector Darlington pair drive transistors 32 for thermal printhead elements (not shown) connected as loads to the Darlington pair transistors 32. A decoder 34 is connected by lines 36 to the multiplexing gates 20. Inputs to the decoder 34 are supplied on lines 38, 40 and 42. A transfer enable input is supplied to 6-bit storage register 22 on line 44. Clock and data inputs are respectively supplied on lines 46 and 48 to the 6-bit serial in parallel out shift register 24. In addition to the parallel outputs on lines 28 from the serial in parallel out shift register 24, a serial output is also supplied on line 50 to buffer 52 for transmission off the integrated circuit on line 54.
In operation, the Darlington pair output transistors 32 provide drive signals to thermal printhead elements when selected by operation of the decoder 34 and the multiplexing gates 20, and when the +VCC supply voltage is above a predetermined level, as determined by the sense amplifier circuit 10. Further details of an integrated circuit incorporating the block diagram of FIG. 1 are available in the above-referenced, concurrently filed Kuo et al application, and the above-referenced Kuo application, the disclosures of which are incorporated by reference herein.
Turning now to FIG. 2, there is shown a circuit schematic of the sense amplifier circuit 10 of FIG. 1. The sense amplifier circuit 10 incorporates a temperature-compensated reference voltage circuit, which establishes a reference voltage Vref at the base electrode of transistor Qs7. The voltage to be compared against the reference voltage Vref is supplied at the base electrode of transistor Qs6. If that base electrode voltage is less than Vref, transistor Qs7 is on and Qs6 is off. It will be noted that the FIG. 2 embodiment is a silicon band-gap voltage reference circuit, i.e., Vref is equal to 1.31 volts. However, unlike the Widlar band-gap voltage reference circuit, no frequency compensation MOS capacitor is required. As will be seen from the following discussion, Vref could be selected to be essentially any value somewhat less than the +VCC supply voltage, but there are certain advantages from a semi-conductor device physics standpoint in choosing the silicon band-gap voltage of 1.31 volts.
Vref is established by current Ir through the path including transistor Qsp3, line 60, resistor Rs10, and transistor Qs9 to ground via line 62. Transistor Qsp3 has a positive temperature coefficient of current. Transistor Qs9 has a negative temperature coefficient base-to-emitter voltage Vbe, obtained by making Qs9 a vertical NPN transistor. Transistors Qsp1 and Qsp2 are lateral PNP transistors each having an identical configuration to transistor Qsp3.
Transistors Qs10 and Qs12 each have a positive temperature coefficient of current. The current through transistor Qs10 is mirrored through Qsp3. Feeding the mirrored current through resistor Rs10 provides a positive temperature coefficient voltage drop. This positive voltage drop will compensate for the negative temperature coefficient of the Vbe of Qs9.
Transistor Qs13 is used to start up the amplifier 10. When +VCC reaches a threshold level of three times the Vbe of transistor Qs13, for the particular circuit arrangement shown, that transistor conducts. Transistor Qs13 then provides the start-up current for transistor Qs11 so that the current flow path including transistor Qsp1, line 64, resistor Rs12, line 66, transistor Qs12, line 68 and line 62 to ground conducts its final current of 0.15 mA. This results in a sufficient voltage drop across resistor Rs12 to cut off transistor Qs13, because the base of transistor Qs13 is clamped at 2.2 volts by Schottky diodes 63 and 65 and diodes Qds1 and Qds2.
The emitter width of transistor Qs10 is twice the emitter width of transistor Qs12. Since transistors Qsp1 and Qsp2 have identical geometries, their collector currents are equal, and the emitter currents of transistors Qs10 and Qs12 are likewise equal. Accordingly, the current density of transistor Qs12 is twice that of transistor Qs10. Current through the path consisting of transistor Qsp2, line 70, transistor Qs11, line 72, transistor Qs10, line 74, resistor Rs11, and line 76 is equal to the current Ir in the current flow path including transistors Qsp3 and Qs9. Both current flows are equal to kT1n2/qRs11, wherein k is Boltzmann's constant, T is absolute temperature, and q is the charge of an electron. Therefore, ##EQU1## Current flow through resistor Rs11 is thus duplicated through resistor Rs10. As a result, Vref can be set to the band-gap voltage of 1.31 volts with proper selection of Rs10/Rs11.
FIG. 3 is an operation and timing waveform diagram of the sense amplifier circuit 10 in FIG. 2, useful for understanding operation of the sense amplifier circuit 10. Before +VCC reaches 4.2 volts as shown at 100 in the +VCC curve 101 of FIG. 3, transistors Qsc and Qs1, Qs2, Qs3 and Qs4 are in saturation, as indicated at 102 in the waveform 103 of the voltages Vsc, Vs1, Vs2, Vs3, and Vs4, which represent, respectively, the voltages at terminals 104, 106, 108, 110 and 112 in FIG. 2. When +VCC reaches 4.2 volts, a voltage level of 1.31 volts is established at 121 between resistors Rs15 and Rs16. Transistor Qs6 turns on, causing current flow in the path including resistor Rs9, line 114, transistor Qs6, line 116, transistor Qs8, and line 118 to ground. As a result, transistor Qsp4 is turned on to produce current flow in line 120, thus turning on transistor Qs5. When transistor Qs5 saturates, transistors Qsc and Qs1, Qs2, Qs3 and Qs4, which disable the printer driver when they are on, are then cut off. Resistors Rs17, Rs18 and Rs19 establish proper voltage levels at the bases of transistors Qs5, Qsc, Qs1, Qs2, Qs3, and Qs4 for operation as set forth above.
Waveforms 122 and 124 show the voltages, respectively, at the bases of transistors Qs6 and Qs7 in operation of the circuit.
The supply voltage sense amplifier circuit of FIG. 2, in addition to being useful for driving an array 32 of Darlington pair power transistors (FIG. 1) used to drive a thermal printhead, can also be used in MOS or charge coupled device (CCD) memory systems to disable transistor-transistor logic (TTL) circuitry or to enable other drivers from a power supply, resulting in power savings.
FIG. 4 shows an alternative embodiment of the invention, in which the temperature-compensated reference voltage circuit of this invention is used in a programmable reference voltage circuit 200. The elements in the left portion 202 of this circuit are identical to corresponding elements in the circuit of FIG. 2, and corresponding references for them are employed in FIG. 4. Also, they operate in the same manner as the corresponding elements in FIG. 2, and their operation will, therefore, not be explained at this point. Transistors Qsp6A and Qsp6B have, respectively, been added above transistors Qs7 and Qs6. Capacitor C1 connects the collector and base of transistor Qs6. Darlington pair transistors Qs14 and Qs15 are connected between the +VCC supply voltage and ground by lines 204, 206, 207, resistor Rs20, line 210, resistor Rs21, line 212, variable resistor Rs22 and line 214.
In operation, the circuit of FIG. 4 provides a reference voltage Vo, which may be set to a desired level by varying the resistance of variable resistor Rs22. If the voltage at line 212 is higher than Vref, i.e., 1.31 volts in the embodiment, Qs6 will conduct more current until the voltage at 212 equals Vref. Since changing the value of variale resistor Rs22 changes the operation point of the circuit at which the voltage at 212 equals Vref, such variation in turn varies output reference voltage Vo of the circuit 200. The reference voltage Vo is temperature compensated as a result of operation of the temperature-compensated voltage reference Vref and sense amplifier portion of the circuit 200, in the same manner as in the FIG. 2 embodiment.
It should now be apparent to those skilled in the art that a temperature-compensated reference voltage and supply voltage sense amplifier circuit capable of achieving the stated objects of the invention has been provided. The temperature-compensated reference voltage is frequency independent, without requiring the use of a frequency compensation capacitor. The supply voltage sense amplifier circuit incorporating the temperature-compensating reference voltage circuit of this invention provides voltage control signals to load elements, and will provide outputs to at least two different load elements, depending on the level of a supply voltage. Another version of the circuit supplies a programmable, temperature-compensated output reference voltage to a load element.
It should further be apparent to those skilled in the art that various changes in form and details of the invention as shown and described may be made. It is intended that such changes be included within the spirit and scope of the claims appended hereto.
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A temperature-compensated reference voltage circuit includes a transistor having a positive temperature coefficient of current. A circuit for establishing a predetermined current in the positive-temperature-coefficient-of-current transistor is connected to that transistor. A predetermined resistance serially connects the positive-temperature-coefficient-of-current transistor with a transistor having negative temperature coefficient of base-to-emitter voltage. The temperature-compensated reference voltage is established between the transistors. The temperature-compensated reference voltage circuit is particularly useful in a supply voltage sense amplifier circuit for thermal printhead drive transistors or other load elements. The sense amplifier circuit includes a circuit for comparing the reference voltage and a supply voltage. An output is adapted to be connected to a load for receiving the supply voltage. A circuit is connected to receive an input from the comparing circuit, and to said output, for enabling the output when the supply voltage is equal or greater than the reference voltage.
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FIELD OF THE INVENTION
[0001] This invention relates generally to advances in medical systems and procedures for prolonging and improving human life. More particularly, this invention relates to an improved method and system for alleviating urinary obstruction caused by enlargement of the prostate by performing thermal high frequency ablation for urethral enlargement.
BACKGROUND OF THE INVENTION
[0002] A majority of all males over 60 years old experience partial or complete urinary obstruction because of the enlargement of the prostate. This condition usually originates from benign prostatic hyperplasia (BPH), which is an increase in cell mass near the urethra, or less likely, from prostate cancer. Both of these conditions involve an increase in prostatic tissue mass, which in its increased state encroaches on the urethra and obstructs the urinary pathway.
[0003] In the case where urinary obstruction is caused by BPH, a common treatment involves a medical procedure using a side-cutting instrument and/or endoscope to surgically enlarge a passageway for urine flow through the prostate. The side-cutting instrument, which is typically passed through an endoscopic tube, is passed through the penis into the urethra and is used to surgically remove prostate tissue and part of the urethra at the point of the obstruction. This procedure is referred to as โTrans-urethral Resection of the Prostateโ (or โTURPโ). Typically, the TURP procedure removes more than superficial tissue layers, that is, more than a diameter of 10 millimeters around the urethra, since the BPH condition could advance, creating repeated BPH obstruction. Using the TURP procedure, the surgical cavity that is created in the prostate can be tailored to the prostate size, both in length and diameter. The TURP procedure can also avoid critical structures such as the bladder neck, the rectal wall, which is adjacent to the prostate, and the erectile nerves at the border the prostate on the rectal side.
[0004] In the case where urinary obstruction results from prostate cancer, surgical prostatectomies are commonly used to eliminate the obstruction.
[0005] In recent years, less invasive systems and procedure that inflict less trauma on the patients have been attempted. One such procedure, called โTrans-urethral Needle Ablationโ (or โTUNAโ), involves passing a radio-frequency (RF) instrument such as a catheter, cannula, sheath, or scope into the urethra. The RF instrument houses special RF electrode tips that emerge from the side of the instrument. The tips are pushed out of the instrument along off-axis paths to pierce the urethral wall and pass into the prostatic tissue outside of the urethra. The TUNA system and procedure attempts to leave the urethra intact and uninjured by the application of RF heating.
[0006] Another minimally invasive technique for treating BPH is Trans-urethral Microwave Thermo Therapy (or โTUMTโ). This involves use of a cooled catheter which also delivers heat energy to the prostate. A catheter that has a microwave probe inside of it is inserted into the urethra to the point of the prostate. The microwave probe is typically a microwave antenna which is located inside the catheter near its distal end and is connected to an external generator of microwave power outside the patient's body. In this way the prostate is heated by radiative electromagnetic heating. At the same time the catheter is cooled by circulation of a coolant fluid within the catheter. The objective is to cool the urethra and thereby to prevent damage to it by the heating process which is occurring in the prostatic tissue that is outside of and at a distance from the urethra. Thus, the TUMT procedure seeks to preserve the urethra and the prostatic tissue immediately outside of the urethra by cooling the catheter with fluid coolant that is circulated within the catheter. In the TUMT procedure, the prostatic tissue immediately around the urethra and the urethra itself are deliberately spared from receiving an ablative level of heating, that is, the temperatures for these structures are less than 50 degrees C.
[0007] It should be recognized that the theory behind and practice of RF heat ablations has been known for decades, and a wide range of RF generators and electrodes for accomplishing such practice exist. For example, equipment for performing heat lesions is available from Radionics, Inc., located in Burlington, Massachusetts. Radio-frequency (RF) ablation is well known and described in medical and clinical literature. To that end, a research paper by E. R. Cosman, et al., entitled โTheoretical Aspects of Radio-frequency Lesions in the Dorsal Root Entry Zone,โ Neurosurgery , vol. 15, no. 6, pp. 945-950 (1984), describing various techniques associated with radio-frequency lesions, is hereby incorporated by reference herein in its entirety. Also, a research paper by S. M. Goldberg, et al., entitled โTissue Ablation with Radio-frequency: Effect of Probe Size, Gauge, Duration, and Temperature on Lesion Volume,โ Acad. Radiol ., vol. 2, pp. 399-404 (1995), describes techniques and considerations relating to tissue ablation with radio-frequency energy, and is hereby incorporated by reference herein in its entirety.
SUMMARY OF THE INVENTION
[0008] According to the invention, a device for enlarging a urethral passage includes an elongate member having a distal portion configured for intraurethral placement in the urethral passage, and an electrode at the distal portion of the elongate member. The electrode is configured to be energized with high frequency energy to necrose tissue of the urethral wall and surrounding prostate tissue to form a cavity in the urethral passage. The electrode has an adjustable working length.
[0009] Embodiments of this aspect of the invention may have one or more of the following features.
[0010] A removable insulative member covers at least a portion of the electrode. The device includes an insulating sleeve and the electrode is movable relative to the insulating sleeve to adjust the working length. The electrode has a diameter greater than about 16 French to substantially occlude the urethra. The electrode is disposed on an outer surface of the distal portion of the elongate member. The device includes multiple electrodes at the distal portion of the elongate member, and multiple wires each for independently coupling one of the multiple electrodes to a high frequency electrical signal. The electrodes are spaced apart a distance of about 1 to 5 mm.
[0011] According to another aspect of the invention, a device for enlarging a urethral passage includes an elongate member having a distal portion configured for intraurethral placement in the urethral passage, and a plurality of electrodes at the distal portion of the elongate member. The electrodes are configured to be energized with high frequency energy to necrose tissue of the urethral wall and surrounding prostate tissue to form a cavity in the urethral passage. The electrodes are spaced apart a distance of about 1 to 5 mm to provide flexibility in the distal portion of the elongate member.
[0012] Embodiments of this aspect of the invention may include one or more of the following features.
[0013] The electrodes have a diameter greater than about 16 French to substantially occlude the urethra. The device includes multiple wires each for independently coupling one of the multiple electrodes to a high frequency electrical signal. The high frequency electrical signal can be selectively applied to each of the electrodes to adjust a length of the region of ablative heating. The electrodes are disposed on an outer surface of the distal portion of the elongate member. A removable insulative member covers at least a portion of one of the electrodes.
[0014] According to another aspect of the invention, a method of treating a urethral passage includes measuring a length of a patient's prostate, and selecting a length of an electrode based on the measured length of the prostate. The electrode is configured to be energized with high frequency energy to necrose tissue of the urethral wall and surrounding prostate tissue to form a cavity in the urethral passage.
[0015] Embodiments of this aspect of the invention may include one or more of the following features.
[0016] The electrode includes multiple electrodes and the step of selecting includes determining which electrode to energize. The step of selecting includes removing insulation from the electrode. The step of selecting includes advancing an electrode relative to an insulating sleeve.
[0017] The method includes selecting a diameter of the electrode that substantially occludes the urethra, and energizing the electrode with high frequency energy to elevate the temperature of the urethra to at least 50ยฐ C. to ablate tissue of a wall defining the urethral passage and ablate adjacent prostate tissue to form a cavity communicating with the urethral passage.
[0018] Advantages of the invention may include a minimally invasive ablation technique that simulates the advantages of TURP, for example, tailoring the formed cavity or void according to the length of the prostate and producing a cavity diameter that is beyond the superficial tissue layers around the urethra, that is cavity diameters greater than about 10 to 12 millimeters. An ablation volume within and around the prostatic urethra is created minimally invasively in accordance with the size of the patient's prostate and other clinical criteria such as the preservation or non-preservation of the bladder neck, and matching the physiologic anatomy and size of the urethra and prostate for a specific patient.
[0019] The technique requires a very short time to perform, for example, less than ten minutes and preferably in the range of two to six minutes, in which time the patient can be maintained comfortably without undue anesthetic and without experiencing undue pain or distress. The procedure can be performed in a doctor's office or in an outpatient setting, without requiring an operating room or extensive, sophisticated personnel such as anesthesiologists and nurses.
[0020] The ablation is performed for the treatment of BPH and the associated alleviation of urethral obstruction. The ablation can also be used to treat other diseases such as prostate cancer to alleviate urethral obstruction.
[0021] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent form the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In the drawings which constitute a part of the specification, embodiments exhibiting various forms and features hereof are set forth, specifically:
[0023] [0023]FIG. 1 is a schematic diagram showing a portion of a patient along with a system according to the invention for performing intraurethral thermal ablation of the urethra and central prostate;
[0024] [0024]FIG. 2 shows an embodiment of a prostate ablation catheter passed into the urethra in accordance with the present invention;
[0025] [0025]FIG. 3 shows another embodiment of the prostate ablation electrode having an insulative band according to the present invention;
[0026] [0026]FIG. 4 shows an embodiment of a prostate ablation electrode with multiple electrode elements on a catheter and a selectable, insulative band in accordance with the present invention;
[0027] [0027]FIG. 5 shows an embodiment of a prostate ablation electrode according to the present invention having a universally adjustable, conductive surface exposure;
[0028] [0028]FIG. 6 shows an embodiment of a prostate ablation probe according to the present invention having a multiplicity of conductive elements disposed on the surface of the probe for selectable ablation positioning and length;
[0029] [0029]FIG. 7 shows an embodiment of the prostate ablation probe according to the present invention with a multiplicity of selectable insulation bands on the conductive electrode element;
[0030] [0030]FIG. 8 shows an embodiment of the prostate ablation probe according to the present invention comprising two circumferential electrode rings on a flexible catheter with removable insulative bands and temperature sensors for grading the size and length of ablation volume;
[0031] [0031]FIG. 9 shows an embodiment of a probe for prostate ablation according to the present invention with a continuously adjustable, exposed electrode length and position;
[0032] [0032]FIG. 10 illustrates a sectional view through the prostate showing a coapted urethral channel;
[0033] [0033]FIG. 11 illustrates a sectional view through the prostate with a small size ablation probe within the prostatic urethra;
[0034] [0034]FIG. 12 illustrates a sectional view through the prostate with a small size probe within the prostatic urethra and also fluid within the urethra;
[0035] [0035]FIG. 13 illustrates a sectional view of the prostate with an occlusive ablative electrode within the urethra and accompanying zones of ablation in accordance with the present invention;
[0036] [0036]FIG. 14 illustrates the temperature distribution versus the distance from the electrode for a prostate ablation electrode at various power and time parameters in accordance with the present invention;
[0037] [0037]FIG. 15 shows a flow chart of the process employing, in operation, a system in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0038] Referring to FIG. 1, in a system 10 in accordance with the present invention, an elongated probe 1 is inserted via the penis PN into the urethra U of a living body such as a patient, and into an operative field within the patient's body, specifically including the prostate gland P. In this exemplary embodiment, probe 1 is a flexible rubber catheter that facilitates introduction of the probe into the urethra. Probe 1 has a distal, rounded tip 11 and a drainage hole 12 . When located inside the patient's bladder B, drainage hole 12 allows irrigation and flushing of the contents of the bladder via fluid channels 16 within probe 1 . Probe 1 has a balloon 7 inflated via an inflation channel 18 within probe 1 . Once placed within bladder B, balloon 7 is used to anchor the position of probe 1 by applying a pulling or tension force on probe 1 so that balloon 7 is brought tightly against the bladder neck BN portion of the prostate.
[0039] Probe 1 has conductive electrode elements 4 and 5 , which are positioned on the rubber substrate of probe 1 such that when balloon 7 is brought snugly against the bladder neck BN, electrodes 4 and 5 are appropriately positioned within the prostate to perform thermal prostatic ablation. The course of the prostatic urethra PU and external urethra U has significant and acute curves from the penis into the bladder, and flexibility of the probe structure 1 and the portion of the probe near electrodes 4 and 5 is advantageous to facilitate insertion of the catheter and for patient comfort. Between electrodes 4 and 5 is a gap 22 formed by the insulative rubber substrate of probe 1 . When the length of gap 22 is appropriately chosen, for example, in the range of 1 to 6 mm or more, there is sufficient flexibility between electrodes 4 and 5 to easily introduce probe 1 into the external urethra U and the prostatic urethra PU without patient discomfort. Spaced electrodes 4 and 5 allow heat ablation to be done in a sequential, segmented fashion with each electrode activated separately to produce zones of ablation, as illustrated by dashed line 20 , associated with the heat ablation zone for electrode 4 , and dashed line 24 , associated with the heat ablation zone for electrode 5 . With a sufficiently small gap 22 , for example, 1 to 5 millimeters, zones 20 and 24 overlap so the aggregate ablation zones does not have discontinuities or undesired irregularities in shape.
[0040] System 10 includes an ultrasonic imaging device 26 , which is placed intra-rectally through the anal opening A. Device 26 has an imaging head 28 , for example, an ultrasonic scanning transducer, which rests against the rectal wall R near the prostate T. The ultrasonic imaging device 26 may be any common tool used in diagnostic medicine, for example, Accuson, Inc., located in Mountain View, Calif., provides several suitable ultrasonic imaging devices. Imaging head 28 scans the region of tissue falling within, for example, the area bounded by the dashed lines 31 , to generate a visual image. This image may include the rectal wall R, the prostate, the urethra, and the electrode elements 4 and 5 . The ultrasonic scanning head 28 is connected to an ultrasonic image processing unit 68 and a display unit 70 , as is common practice. The display 70 provides real-time ultrasonic images of the prostate with the position of electrodes 4 and 5 shown relative to the prostate P, the bladder neck BN, and the bladder B to confirm the position of the electrodes and the probe within the prostate prior to heat ablation.
[0041] Positioning of electrodes 4 and 5 within the prostate is important, since it determines where the ablation volumes 20 and 24 will occur and whether the ablation volumes will impinge on critical structures. One critical structure is the external sphincter ES. This is located at the so-called โapex endโ of the prostate P, just outside the prostate and surrounding the urethra U in that region. The external sphincter controls urinary function, and if damaged by heat ablation can leave the patient incontinent. Thus it is very important in the treatment of BPH to spare the external sphincter. Thus it is important that ablation zone 24 does not spread into the external sphincter, causing permanent damage. Another critical structure is the bladder neck BN located at the bladder end of the prostate B, and containing the internal sphincter, which surrounds the prostatic urethra in that region. The bladder neck controls aspects of sexual function, including providing means to prevent retrograde ejaculation. Surgeons performing the TURP procedure sometimes will spare the bladder neck BN, and sometimes will not spare the bladder neck, depending on clinical indications. In the case of the present invention, one objective is for the urologist to have the option to spare or not spare the bladder neck for the same considerations that would be given for a TURP surgical procedure. Another critical region is the posterior prostatic wall PW. It is closest to the rectal wall R and also close to critical nerves associated with sexual performance that run between the posterior wall PW and the rectal wall R. These nerves, in part, control erectile function and if they are damaged can lead to impairment. The spread of heat ablation zones 20 and 24 could cause damage to these critical areas. These clinical considerations are used to determine the selected length and position of the electrodes and the time and temperature parameters of the heat ablation process.
[0042] Electrodes 4 and 5 are connected to an external generator 44 by internal wires (not shown) within probe 1 . The wires provide separate connections for the electrodes 4 and 5 into a hub 37 pf probe 1 . Hub 37 is connected to generator 44 by an external connection 40 . The generator 44 is a source of high frequency electrical voltage or current that can be applied through the connection 40 and the internal wires within probe 1 to electrodes 4 and/or 5 to produce heat ablation in the prostate. For example, RF voltage applied from the generator to electrode 4 causes RF current to emanate through the urethral and peri-urethral tissue of the prostate located near to and in the region of electrode 4 . The RF current has its highest concentration near the electrode 4 and falls off as the distance from electrode 4 increases. In a typical arrangement, the current returns to the generator through a large-area reference electrode 60 placed elsewhere on the skin S of the patient's body and connected to the generator 44 by a cable 55 . The RF current within the tissue produces energy deposition in the tissue at a distance from the electrode due to the electrical resistivity of the tissue. It is the electromechanical dissipation of this deposited RF energy in the tissue that causes the tissue to heat up near the electrode 4 . Tissue heating to greater than approximately 50ยฐ C. for several minutes causes death of the cells and constituents of the tissue. The temperature falls off from the region near the electrode 4 and defines a zone of 50ยฐ C. temperature, which is the isotherm associated with the ablation volume, as illustrated by the dashed curve 20 in FIG. 1.
[0043] The dimensions and size of the ablation volume 20 may be increased by increasing the output power from the generator 44 through the electrode 4 and is influenced by the geometry of the electrode 4 . Thus, the size and volume of the ablation zone 20 can be graded and controlled around the urethral channel near the electrode by choice of RF generator parameters, electrode geometry, and the time of treatment. For example, an electrode 4 having a length of 15 mm and a diameter of 7 to 8 mm used to heat the adjacent tissue to 70ยฐ C. for three minutes creates an ablation volume with a diameter of about 20 mm and a length of about 21 mm. Increasing the treatment time to five minutes increases the ablation diameter to about 24 mm. When electrode 4 is used to heat the adjacent tissue to 80ยฐ C. for three minutes, the ablation diameter is about 28 mm. Increasing the treatment time to five minutes increases the ablation diameter to about 30 mm.
[0044] The generator 44 can have many control and readout functions associated with the RF parameters of the ablation process. These are illustrated in FIG. 1 by meters 48 and 51 , which display output power, current, voltage, impedance, or other parameters associated with the heating process. Also, control aspects of the generator illustrated by element 52 can manually, automatically, or by computer control govern and monitor the process and parameter display of RF signal application to the electrodes and time parameters during the procedure. The generator 44 is, for example, a high frequency generator with various possible frequency ranges: several tens of kilohertz to 100 kilohertz; 100 kilohertz to 1 megahertz; 1 megahertz to several megahertz or several hundred megahertz, or even greater frequencies are possible. Radiofrequencies in the 100 kilohertz to 100 megahertz are effective. Connection cable 40 can, for example, deliver RF output to electrode 4 individually, electrode 5 individually, electrodes 4 and 5 in combination, or electrodes 4 and 5 in a bipolar electrical arrangement. In a bipolar configuration, current flows between the electrodes 4 and 5 , and the tissue surrounding the electrodes acts as a bodily ionic medium through which the current has a volumetric current pathway between the electrodes.
[0045] Probe 1 includes index markers 35 that provide a gauge of the depth of the probe within the urethra with the markers referenced to the external urethra by the penis PN. Markers 35 help in positioning the catheter and electrodes within the prostate and/or act as a check that the electrodes do not move during RF treatment.
[0046] Generator 44 has a power range from, for example, 0 to 50 watts or more. Probe 1 can include temperature sensors (not shown) such as thermocouple sensors built into the electrodes 4 and/or 5 . The temperature sensor is connected via connector wires extending inside the shaft of probe 1 to the energy source 44 through the connection cable 40 . The measured temperature at the electrode is representative of the temperature of the urethra and very nearby prostatic tissue as the RF heat ablation proceeds. The temperature can be displayed on the meter 48 so that the clinician can monitor the progress of the ablation.
[0047] The probe 1 has a length of, for example, approximately 20 to 30 centimeters. The diameter of electrodes 4 and 5 is, for example, greater than 16 French (5.3 millimeters) and preferably in the range of 18 to 27 French (6 to 9 millimeters) to effectively occlude the prostatic urethra and provide complete contact of the electrode to the urethral tissue. A 20 French probe 1 accommodates nearly all urethras comfortably.
[0048] Referring to FIG. 2, the external sphincter ES surrounds the urethra and is adjacent to the external side or apex end of the prostate as the prostatic urethra PU exits the prostate P. The bladder neck BN representing the portion of the prostate next to the bladder includes the internal sphincter. The margin of the internal sphincter is indicated by the line 90 . The length of the prostate is shown as PL 2 and is typically defined as the length of the prostatic urethra PU from the exit margin of the prostatic urethra from the prostate at the external sphincter end to the exit margin 89 of the prostatic urethra at the bladder end. Another definition of the prostatic length PL 2 is from the bladder neck margin 89 to the verumontanum, which is an anatomical landmark in the prostatic urethra very close to the position of the exit of the prostatic urethra at the external sphincter end of the prostate P. The thickness of the internal sphincter or bladder neck BN is shown as BNL 2 .
[0049] As shown in FIG. 2, a probe 77 is formed by a flexible catheter 77 a made from, for example, plastic or similar material such as silicone, latex, polyurethane, polyethylene. Probe 77 includes a conductive RF electrode 84 disposed on the surface of probe 77 , and a balloon 92 for fixing or anchor the RF electrode's position within the prostate. The active electrode length is shown as EL 2 , and is the length of the conductive electrode surface 84 . A region of heat ablation produced by penetrating radio-frequency energy deposition into the prostate tissue around the electrode 84 causes cell death and necrosis within an ablation volume indicated by the dashed line 94 . The dashed line 94 corresponds approximately to a 50ยฐ C. isotherm volume boundary. All tissue within that 50ยฐ C. isotherm margin, or ablation volume margin 94 , is killed. The length of the ablation volume is shown in FIG. 2 as AL 2 , and the diameter of the lesion volume is designated AD 1 . There is a variation in temperature within the ablation volume so that if the boundary 94 corresponds to a 50ยฐ C. isotherm, tissue within the volume and closer to the electrode 84 is at a higher temperature.
[0050] Subsequent to an RF ablation, with an applied duration or RF heating of a minute or several minutes, the cells within the isotherm 94 die, and within several days or a few weeks the dead cells liquefy and no longer have the usual integrity of living cells. This region of obliteration will, in the course of several days after treatment, form a cavity with a margin corresponding to the dashed line 94 . The cavity is contiguous with the prostatic urethra on each end outside the ablation volume, and thus serves to remove prostatic mass and unobstruct the prostatic urethral region that is affected by the BPH disease. Removal of the probe 77 after several days or approximately two weeks following the RF ablation results in the debris from the necrotic cells in the ablated zone being flushed out of the cavity within margin 94 via the urine, leaving a cavity or void in the prostate. Thus, a portion of the prostatic urethra and a portion of the tissue that surrounds the urethra are obliterated by the RF heat ablation process.
[0051] The configuration and positioning of the RF electrode within the prostate is selected to tailor and match the associated ablation volume to the size and geometry of the prostate and/or to specific clinical considerations of the extent of the ablation volume desired. In FIG. 2, the ablation volume, represented by the line 94 , approximates the length of the prostate PL 2 and achieves a significant ablation diameter AD 1 . The size, position, length, and diameter of the ablation volume 94 approximate the size of a cavity in the prostate achieved by the surgical TURP procedure, discussed above. Thus the ablation diameter AD 1 surpasses the intermediate zone around the urethra (approximately 10 millimeters diameter) achieving a diameter of 20 millimeters or more. This requires penetration of the ablation volume well beyond the prostatic urethra and superficial periurethral tissue (tissue within a radial distance of about 5 millimeters from the surface of the electrode 84 ). RF current emanating from electrode 84 heats the tissue at a distance from the electrode. The current spreads from the electrode 84 into the tissue and causes frictional heating within the tissue mass by the oscillatory motion of the ionic tissue medium. The heat deposition in the surrounding tissue of the prostate is deposited immediately without relying on thermal convection to spread into the tissue volume near the electrode. Thus the heating process can take place rapidly, which increases the efficiency of the procedure, the safety, and the comfort to the patient.
[0052] The electrode length EL 2 is selected to form an ablation length AL 2 that approximates a measured prostate length PL 2 . By natural human physiology, there is a wide range of prostate lengths PL 2 , for example, from about 25 millimeters to 60 millimeters or more. When it is desired to spare the bladder neck or leave a few millimeters of unablated margin at the apex end of the prostatic urethra, the electrode length EL 2 is chosen to be somewhat shorter than PL 2 . The position of electrode 84 in relation to the adjacent margin 89 of the balloon 92 determines whether the RF ablation margin 94 engulfs the bladder neck BN. The gap between the electrode and the proximal margin of the balloon 89 is designated as EPG 2 . This is a selectable dimension that determines if the RF ablation includes the bladder neck. If the gap EPG 2 is sufficiently small, for example, within the range of 0 to 3 millimeters, the ablation margin 94 spreads in the direction of the bladder encroaching on or engulfing the region of the bladder neck BN (within margin 90 ), as indicated in FIG. 2. With a larger gap EPG 2 , for example, 5 to 7 millimeters, or 7 to 10 millimeters, the dashed line 94 does not overlap the bladder neck BN, and thus the bladder neck BN is spared. If desired, the electrode length can be selected to leave a margin at the end of the prostatic urethra nearest the external sphincter so that there is no danger of ablation of the external sphincter. Thus, the length of the electrode 84 is preferably selectable or adjustable by the urologist. In use, the urologist first measures the prostatic length PL 2 of the patient. Based upon a consideration of what anatomical features to preserve, the length of the electrode 84 and the length of the gap between the electrode and bladder EPG 2 are selected.
[0053] Catheter 77 a has a diameter of, for example, 20 French (6.7 millimeters) (which is typical for some urological catheters), 18 French, 16 French, or smaller. The electrode 84 is, for example, a metallic cylindrical ring that is affixed over or to the external surface of the catheter 77 a . Electrode 84 has a diameter of, for example, greater than 16 French (5.3 millimeters) such as: 6 mm; or 7 mm; or 8 mm; or 9 mm; or 10 mm, depending on the diameter of the patient's urethral. Electrode 84 has a length of, for example, 15 millimeters. The probe diameter can be significantly smaller, for example, 2 to 5 French smaller, than the electrode diameter to provide increased flexibility while maintaining an occlusive diameter for the electrode. The wall thickness of electrode 84 is in the range of, for example, 0.001 millimeters to 1 millimeter or more. Any spacing between the electrode and the catheter can be filled in with, for example, silicone. A temperature sensor can be located between catheter 77 a and electrode 84 or imbedded in electrode 84 .
[0054] Connecting a 15 mm long ring electrode 84 to an RF generator, raising the RF power to a level so that the urethral temperature adjacent to electrode 84 is 70ยฐ C., and maintaining that temperature for three minutes, produces an ablation volume with a length AL 2 of approximately 19 to 21 millimeters and an ablation diameter AD 1 of approximately 20 millimeters. Selecting the proximal electrode gap EPG 2 beforehand to be approximately 3 millimeters or less results in the ablation volume 94 encompassing most or all of the bladder neck BN, including the internal sphincter. However, selecting a gap EPG 2 of approximately 5 millimeters or more results in the ablation volume not eclipsing a substantial portion of the internal sphincter, thus sparing the bladder neck.
[0055] The ablation volume length AL 2 is such that the ablation margin 94 extends approximately 2 to 3 millimeters beyond the ends of the electrode 84 . Thus, at the distal end of the electrode 84 closest to the external sphincter, a sufficient electrode distal gap, designated as EDG 2 , can be selected to avoid damage to the external sphincter. Thus, for example, if the gap EDG 2 is greater than approximately 5 millimeters, the ablation border 94 is 2 millimeters or more from the margin of the external sphincter. Thus, a 15 mm long electrode is suitable for a prostate having a length PL 2 of 20 to 25 millimeters. Longer electrodes accommodate longer prostates, for example, an electrode length of 20 millimeters is suitable for prostate lengths of 25 to 30 millimeters, and electrode lengths EL 2 of 25, 30, 35, 40, 45, 50 and 60 millimeters can be selected to accommodate longer prostates.
[0056] The electrode 84 is, for example, an annular ring, metal braid, surface fiber, coating, wire helix, coil, or wire segment, made from, for example, stainless steel, titanium, nickel alloys, platinum alloys, or copper with surface plating. The probe 77 can be supplied to the urologist in different models with different length electrodes 84 , which the clinician can select for a specific patient.
[0057] Referring to FIG. 3, a probe 96 includes a catheter 96 a and an adjustable length RF electrode 104 . RF electrode 104 is disposed on the surface of the catheter 96 a , and has an exposed, electrically conductive surface portion 106 having length EL 3 , and a non-electrically exposed portion 108 covered by an insulating sheath. The length of the insulated, non-exposed portion 108 of the electrode is designated as IL 3 . An RF ablation volume with margin indicated by the dashed line 101 has an ablation length AL 3 . The length of the insulated portion 108 of the electrode 108 is selected or adjusted to assure that the heat ablation margin 101 does not extend into the bladder neck BN. To this end, the proximal margin 112 of the electrically exposed electrode portion 104 should be at a sufficient gap distance, specified as EPG 3 , from the bladder neck margin 118 . If it is decided based on clinical conditions to destroy the bladder neck BN by heat ablation, the urologist can remove the insulation covering the electrode 104 in the region 108 to enlarge the length of the exposed RF electrode in the direction of the bladder interface 118 . The exposed length of the RF electrode can be adjusted from EL 3 to a potential length of PEL 3 , depending on the degree of removal of the insulation portion 108 .
[0058] The insulative covering is, for example, an insulative tape, a heat shrunk insulative tubing, or a removable insulative coating that the urologist can remove in part or in whole. Margin 112 can be adjustable by the urologist by using a blade to cut along the circumference of the insulative band, removing selected portions and thus adjusting or varying the margin 112 as desired. One or more selectable, discrete insulative bands can be placed on the electrode, or the urologist can remove sections of insulation coverings to verniate the length of the RF electrode to any desired amount. This will in effect verniate the length of ablative cavity produced by RF heating. The proximal margin 116 of the overall potential RF electrode structure 104 is, for example, within 1, 2, or 5 millimeters of margin 118 . The length IL 3 of the insulated band portion 108 is, for example, 1 millimeter to 5 millimeters, or more. If the margin 116 is within 2 millimeters of the bladder neck margin 118 , and the insulative sheath has length IL 3 of 5 millimeters, then leaving the insulated covering 108 in place produces an ablation volume that typically spares the bladder neck BN. Removing the insulation covering 108 to bring the exposed electrode to within 2 millimeters of the bladder neck results in ablation of the bladder neck by the RF heating.
[0059] Referring to FIG. 4, a probe 120 includes a urethral catheter 120 a made of an insulative rubber material and two electrode segments, 121 and 124 , for example, cylindrical metal rings disposed on the external surface of the catheter 120 a . The ring 121 has an electrically exposed area 127 and an insulated portion 125 . Electrode ring 126 has a completely electrically exposed surface 128 . There is a gap G 1 of, for example, 3 to 5 millimeters, between the two rings 121 and 124 . The length of the exposed area 127 on ring 121 is EL 5 . The width of the insulative portion 125 is IL 5 . The length of the exposed conductive area of ring 124 is EL 4 .
[0060] Rings 121 and 124 are coupled to the generator such that the RF generator output can be selectively applied to ring 121 alone, to ring 124 alone, or simultaneously to both rings. If power is applied to ring 121 along, an ablation volume, illustrated by dashed line 131 , is produced having a diameter AD 5 . If electrode 124 is activated separately by the generator RF output, an ablation volume, illustrated by dashed line 137 , is produced with a diameter similar to that for the first ring 121 . Thus, the independent use of RF heating on ring 121 and then ring 124 , sequentially, produces a total ablation volume equal to the sum of the dotted lines 131 and 137 , having an ablation length AL 4 , which is larger than the ablation lengths of each of the independent ablation zones 131 and 137 . Thus, elongation of the ablation length is achieved, and the ablation zone has an ablation diameter approximately equal to AD 5 , which is controllable based on RF parameters for heat ablation on a single ring alone. Furthermore, the gap G 1 between the electrodes 121 and 124 can be selected such that the ablation margins 131 and 137 overlap in the gap region 129 . Thus there are no missing segments in the ablation volume over the ablation length AL 4 .
[0061] Gap 129 provides a degree of flexibility to probe 120 in the region where the electrodes are mounted to catheter 120 a . The urethra as it passes from the external penis to the prostate and then within the prostatic urethra to the bladder takes very significant and relatively sharp turns. If it is desired to have an ablation length AL 4 that corresponds to, for example, a 40 millimeter long electrode, the spaced electrodes advantageously provide increased flexibility of the catheter in the region of the electrodes as compared to a single 40 millimeter long electrode to accommodate the natural physiologic curves of the urethra. It is desirable that the gap between the electrodes be long enough to provide flexibility and yet short enough to prevent gaps in the aggregate ablation volume.
[0062] Referring to FIG. 5, a probe 144 includes, for example, a catheter 144 a and an electrode 146 having a region of exposed electrically conductive surface 147 , a proximal insulated segment 160 , and a distal insulated portion 154 . The total possible electrode length TPEL equals the sum of the exposed area 147 length EL 6 plus the length PG 5 of the insulated portion 160 and the length DG 5 of the distal insulated portion 154 . The proximal gap length PG 5 can be selected, adjusted, or changed by the surgeon by removing segments of insulation over the portion 160 . Similarly, the distal gap DG 5 of the insulated area 154 can be varied, selected, or adjusted by the surgeon by removing portions of its insulated covering. The length of conductive surface 147 can also be varied by removing insulation from portions 154 and 160 to match the electrode length to the patient's prostate length.
[0063] Electrode 146 can be of various designs, for example, a cylindrical ring on the surface of the probe shaft 144 , and the insulation portions 154 and 160 can be insulative tape, heat shrunk on bands, peel-off insulation coatings, or other insulation types. Alternatively, electrode 146 can be a form of conductive wire braid or spiral-wound wire band that has a degree of flexibility, or an end-to-end sequence of annular electrode wires or rings or a mesh or corrugated fenestrated metal cylinder to achieve flexibility. Although the embodiment in FIG. 5 shows a balloon structure 166 with typical catheter drainage end 170 , the use of a non-balloon structure and non-flexible structure is within the scope of the invention.
[0064] Referring to FIG. 6, a probe 189 includes a catheter 189 a and three spaced RF electrodes 191 , 204 , and 211 having exposed surfaces 300 , 310 , and 314 , respectively. Each of the RF electrodes 191 , 204 , and 211 are separately electrically connected to connections 260 , 267 , and 271 , respectively, near the hub 255 of the catheter. Gap segment 220 between electrodes 191 and 204 and gap segment 227 between electrodes 204 and 211 are electrically non-conductive. These gaps can be part of the underlying flexible rubber structure of catheter 189 a . The electrodes can include selectable and/or removable insulative bands or coatings. By selecting to apply power to one, two, or three rings, incremental enlargement of the ablation volume length can be achieved. Thus, the length of the ablation volume can be varied while keeping the ablation diameter approximately constant.
[0065] Probe 144 can universally fit a wide range of physiologic prostate lengths. For example, if only ring 191 of 15 millimeter length is activated by RF signal, then an ablation region of about 20 millimeters long is achieved that can accommodate prostate urethras of 20 to 25 or 30 millimeters length. Activating two rings, 191 and 204 , in sequences induces an ablation region of 35 to 40 millimeters length that can accommodate prostate urethras of length 35 to 45 millimeters. Activating three rings, 191 , 204 , and 211 , sequentially induces an ablation region of 50 to 55 millimeters in length that can accommodate prostatic urethras of length 50 to 60 millimeters long. Adding insulative coverings on these ring electrodes allows even finer verniations of ablation lengths, and thus finer matching to prostate lengths.
[0066] Variations in design of the embodiment in FIG. 6 can achieve universal fitting to various prostate lengths. If prostate lengths of, for example, 25 to 60 millimeters are to be accommodated, and the rings are 10 millimeters long, then four of five rings can be used, with gaps of 2 to 3 millimeters between them. The rings can be activated singly in sequence, or in coupled pairs, or in triplets, or possible all together, depending on the time of the RF application and degree of verniation selected. A probe with 5 to 7 millimeter electrode lengths, and 1, 2, 3, 4, or 5 millimeter gaps may require up to about seven to ten electrode segments to cover the prostate lengths. If 20 millimeter long electrodes are used, then about three electrodes can accommodate a large range of prostate sizes. The longer the individual electrodes, then the less verniation in ablation length is possible, without selectable, adjustable insulation coverings. Mixed lengths of electrode segments can be devised on the probe. Also, various probes can have different numbers of electrode segments to match to various prostate lengths. Electrode segments of 5, 10, 20 or greater millimeter lengths are effective.
[0067] Incremental enlargement of the ablation volume can be done without moving the position of the electrode 189 within the urethra or prostate between heating episodes. Using the balloon 250 on the catheter 189 a to restrain the catheter against the bladder neck margin assures that the electrode positions remain stably placed in the prostate for the duration of the RF heating. This has a significant advantage in terms of certainty of electrode placement once it has been confirmed by imaging and in terms of safety that undesired movement of the electrodes and therefore undesired ablation locations can be avoided.
[0068] Furthermore, if the RF ablations are done individually on each electrode, a degree of incremental control is achieved. The surgeon can produce one heat ablation around one electrode and determine if the patient is in discomfort or if there are any other symptoms providing better control and reduction of risk of injury to surrounding structures. Sequentially applying power to a series of RF electrodes along the length of the urethral catheter lengthens the ablation volume in a controlled way.
[0069] Referring to FIG. 7, a probe 335 includes a catheter 335 a and an electrode 336 spanning the length EL 14 and including a series of segmented domains. One domain is an exposed, electrically conductive surface 364 having an exposed electrode length EL 15 . Surface 364 is spaced from the balloon 358 by an insulative gap 350 . The gap may have beneath it a conductive structure, and comprise an insulative coating that can be removed in a discrete or continuous way. Toward the direction of the hub 407 there is a series of insulative bands 370 , 374 , 380 , 384 , and 390 , each having a length 17 . Beneath each insulative band is a conductive element which can be connected electrically to the exposed conductive surface 364 or be independently connected via connection wires through the hub 407 as part of connection element 410 . A choice of discrete RF electrode lengths is possible, ranging over the length EL 14 . The insulative bands, such as 370 , can be stripped off by a knife or peeled off as with a piece of tape to expose an enlarged RF electrode conductive surface, and thus extending the surface 364 . In this way, the length of the RF electrode, as well as the length of the ablation volume, can be tailored to the length of a particular patient's prostate length. The electrode length can be changed while maintaining the use of temperature sensors and without requiring changing of the wiring to the electrode.
[0070] Referring to FIG. 8, a probe 414 includes a urethral catheter 414 a and two electrodes 420 and 430 separated by a gap G 8 . Electrode 420 has an overall length RE 7 , and is separated by an insulative gap of length PG 8 from the proximal margin 422 of the inflatable balloon 423 . Electrode 420 has an electrically exposed portion 440 with a length EL 20 , and a portion 444 covered by insulation. Electrode 430 has an exposed conductive portion 450 with a length EL 24 , a segment 456 with an insulative coating, and another portion 460 with an insulative coating. The insulative portions 440 , 450 , and 456 may be of different or varied color or identification so that it is easy to determine which insulation should remain and which should be removed to achieve a desired overall ablation length. For example, the insulative bands may be bands of heat shrink Teflon, which are shrunk on and sized to a prescribed incremental length.
[0071] Each of the electrodes 420 and 430 has length of, for example, 15 millimeters. The gap between the electrodes is, for example, approximately 4 millimeters, to provide flexibility and sufficient overlap of independent ablation volumes. The insulative bands 444 , 456 , and 460 have lengths of, for example, 5 millimeters. Each of the insulative bands can easily be removed by a scalpel or scissors. Furthermore, each electrode 420 and 430 has separate electrical connections 480 and 484 , respectively, at the hub 488 of the probe. In use, if the urologist determines that the bladder neck should be ablated, the 5 millimeter long insulative band 444 is removed from the probe prior to insertion. Furthermore, depending on the length of the patient's prostate, the urologist may decide to perform a second RF heating treatment through the electrode 430 . The urologist can remove all or portions of one ore more insulation bands, depending on the desired size of the exposed RF electrode 430 .
[0072] Referring to FIG. 9, a probe 490 includes an insulative sheath or tube 490 a through which an electrically conductive element 500 emerges. Element 500 is, for example, a metal tube or flexible metal structure that slides within sheath 490 . Inside RF electrode element 500 is another tubing 540 with a balloon 517 and a distal tip 518 for insertion into the urethra and anchoring to the bladder. The outer sheath 490 has a hub 511 , and element 500 has a second hub 514 , which slides within hub 511 . Hub 514 has scale markings 521 to gauge the degree of extension length EL 30 of electrode 500 outside of the distal end 507 of sheath 490 . Thus, moving the hub 514 relative to hub 511 changes the length EL 30 of exposed electrode 500 , and thus the length of the RF ablation can be adjusted according to the prostate length. Tubing 540 has a hub 530 , which slides within hub 514 . By moving hub 530 relative to hub 514 , the length PG 9 of the gap between element 500 and balloon 517 can be adjusted according to whether the bladder neck is to be spared or ablated. The electrode structure exposed area 500 is of a flexible construction such as a spiral, braided, multi-ring, segmented, or other flexible metal construction for ease in passage around the curves of the urethra.
[0073] The electrode can be positioned appropriately in the prostate by means other than an anchoring balloon. For example, by imaging with ultrasound, CT, MRI, or X-ray, using index markers, impedance measurements of an impedance electrode on the probe distal portion to detect if the electrode is in the bladder, prostate, or outside the prostate, or visual methods such as having the probe comprise an endoscope or fiber optic channel so that direct visualization of the urethra, prostate, bladder, and other landmarks gives direct optical confirmation of proper electrode position.
[0074] [0074]FIG. 10 illustrates schematically a diagram showing a coronal view through the human prostate and related structures. The prostate PT is shown in a cross-sectional plane that is roughly orthogonal to the prostatic urethra PU. Normally, the prostatic urethra, shown as the solid line PU, is located centrally in the prostate PT and, when the patient is not voiding, is coapted along a vertical line. If the prostatic urethra is opened up to its fullest cross-sectional area, it would approximate a circle, illustrated by the dashed line OPU. The diameter of the open prostatic urethra OPU is nominally 8 millimeters. Nearly all adult prostatic urethras can accept cystoscopes and endoscopes that are 21 to 23 French, i.e., 7 to 8 millimeters, in diameter, and these endoscopes substantially fill the open urethral passage.
[0075] The prostate is a complex of glandular and muscle-like tissue. It has a tissue interface called the โtransition zoneโ at about a 10 millimeter diameter around the urethra. This is indicated by the dashed line TZ. In a surgical TURP procedure, the objective is to surgically cut out a margin of tissue around the urethra, yielding a cavity of a minimum 20 millimeters in diameter, indicated by the dashed line TURP in FIG. 10. This TURP diameter is sufficient to inhibit re-obstruction of the prostate due to advancing BPH disease, and to remove all the material in the transition zone TZ. The posterior margin PM of the prostate is only 3 or 4 millimeters from the rectal wall RW. It is important that the TURP margin does not break through the posterior margin because the rectal wall is a highly critical and sensitive structure. The erectile nerves EN run bilaterally between the prostate posterior margin PM and the rectal wall RW. Avoidance of these critical structures during TURP is very important to preserve sexual function.
[0076] [0076]FIG. 11 illustrates the use of a radio-frequency electrode 550 having a diameter less than approximately 16 French (5.3 millimeters), which does not completely fill the prostatic urethra PU. Thus, the electrode resides in a portion of the partially coapted urethra PU, and the electrode surface does not make substantially full electrical contact with the urethral tissue. This has the disadvantage that the ablation margin, as illustrated by the dashed line 557 , is asymmetrically located with respect to the urethra PU. This runs the risk of inadequate envelopment of the peri-urethral region and re-collapse of the urethral channel under BPH pressure. Furthermore, for a specified temperature of tissue next to the electrode during RF heating, the diameter of the ablation zone 557 is smaller for smaller electrodes. Thus unacceptable or dangerously high core temperatures are required to achieve ablation diameters that approach the effectiveness of that for TURP, resulting in the dangers of unpredictable thermal distributions, focal boiling, charring, gas formation, and unwarranted thermal spread to critical structures increases.
[0077] Referring to FIG. 12, another difficulty that can be encountered with a small electrode that does not fully occlude the urethra PU is the welling up or flow of fluid FL into the urethra PU in the unoccluded area of PU. The fluid FL likely includes urine, an electrically conductive electrolyte. Thus during RF heating from electrode 562 , there is potentially a shunt pathway of the RF current through the fluid FL and out into peri-urethral tissue that is closest to the fluid producing unknown and unpredictable spread of RF current with unacceptable variability of heating direction and range. Furthermore, urine passing from the bladder down the urethra past the electrode provides an electrolytic pathway of RF current and of heat, downstream and potentially upstream in the urethra. This can have safety consequences, since the heat can spread to critical structures such as the external sphincter or external urethra, leading to serious complications.
[0078] Referring to FIG. 13, according to the invention, an RF electrode 570 has a diameter that substantially occludes the fully distended prostatic urethra PU. Urethra PU lies immediately outside of and in contact with the electrode 570 over substantially all of the electrode's surface such that the electrode is in significant mechanical and electrical contact with the urethra during RF ablation. Thus, with the occlusive RF electrode, more complete electrode contact to the urethral wall is achieved, resulting in more effective and symmetrical heating of peri-urethral tissue, and the chance of fluid pooling or flowing between the electrode 570 and the urethra PU is reduced.
[0079] The RF electrode 570 is, for example, a circumferential, electrically conductive ring having a diameter in the range of about 16 French (5.3 millimeters) to 24 French (8 millimeters) or more. There is some variation in urethral size among patients, but nearly all can accommodate, for example, a 20 to 23 French endoscope. Thus, for example, for smaller diameter prostates, a 17 to 20 French (5.6 to 6.6 millimeter) diameter electrode is appropriate. For nominal prostates, a 20 to 22 French (6.6 to 7.3 millimeter) diameter electrode 570 is appropriate. For larger prostates, electrode diameters of 7, 8, or 9 millimeters, or 22, 24, 26, or 28 French are appropriate. Nominally, an electrode diameter of 7 to 8 millimeters would be occlusive to a substantial degree for most human prostatic urethras.
[0080] Dashed lines 577 , 582 , and 591 schematically represent ablation margins from RF heating using electrode 570 . Thermal mapping measurements done using ex-vivo human prostates heated with an RF electrode having an outer diameter of 7.4 millimeters and an electrode length of 10 to 15 millimeters, and applying RF power to raise the tissue temperature at the electrode/tissue interface to 70ยฐ C. for three minutes produced an ablation diameter of approximately 18 to 20 millimeters. The distribution around the electrode is approximately symmetrical, as shown by dashed line 577 . Ex-vivo measurements indicate that if increased RF power is applied to the same electrode to raise peri-urethral tissue to 80ยฐ C., an ablation diameter of about 24 to 28 millimeters is achieved, as represented by the dashed line 582 . Increasing the RF power to achieve higher peri-urethral temperatures of 90 ยฐ C. further increases the radius of ablation to larger diameters, as illustrated by line 591 .
[0081] By using occlusive RF electrodes and modest core peri-urethral temperatures of about 70ยฐ C. for short times such as three minutes, ablation diameters comparable to the diameters resected in TURP surgery are achievable less invasively and less traumatically than in TURP. Furthermore, by applying high frequency or radio-frequency power to the electrode, heat energy is deposited directly in the prostatic tissue at a distance from the electrode, causing immediate temperature rise at longer distances from the electrode. Thus large ablation volumes comparable to those of TURP are achieved in very short treatment times, for example, approximately three minutes, which limits the chance of spread of unwanted heat to critical structures such as erectile nerves, the rectum, the external sphincter, and internal sphincter. With shorter times, risk of electrode movement during the heating is limited.
[0082] RF exposure times of a few minutes in the range of 1 to 5 minutes are desirable. Prostate anatomy indicates use of various temperature and time parameters for RF heating. For example, for larger prostates, longer times such as 5, 7, 10, 15 or 20 or more either in one episode or sequentially increasing time can be used to adequately achieve desired prostate ablation volume. Also, variations in selected core temperatures can vary depending on prostate size. Core temperatures of about 60ยฐ C., 65ยฐ C., 70ยฐ C., 75ยฐ C., 80ยฐ C., 85ยฐ C., 90ยฐ C., 95ยฐ C., or 100ยฐ C., or any temperatures within that range, can be selected to accommodate prostate volume and size.
[0083] A digital rectal thermometry can be used to monitor rectal wall RW temperature during RF heating. As shown in FIG. 13, the clinician uses a finger FG to position a temperature sensor 597 against wall RW at a position near the posterior margin PM of prostate PT. A temperature rise above a warning level such as 40 to 45 ยฐ C. signals to the urologist that unwanted RF heating is spreading near the rectal wall RW, and that RF power should be reduced or turned off.
[0084] [0084]FIG. 14 illustrates the temperature distribution in the tissue as a function of distance from the electrode. An RF electrode was inserted ex-vivo into human prostatic urethra and RF energy supplied to raise the measured temperature at the surface of the electrode. Line 612 indicates the radius of the electrode. For an RF electrode of approximately 23 French (7.7 millimeters), with a temperature at the surface of the electrode of 70ยฐ C., and three minutes of RF heating, the resulting measured data on the distribution of temperature is shown by curve 610 . The temperature is plotted as a function of the radius R in millimeters from the center of the electrode. Body temperature is 37ยฐ C., shown as the dashed horizontal line 601 , which is asymptotically approached by curve 610 for large radius R. The minimum temperature of 50ยฐ C. at which ablation occurs is another horizontal line 604 . The intercept of line 604 with curve 610 corresponds to a radius R of approximately 10 millimeters or a diameter of 20 millimeters. Repeating the measurement for an RF heating time of 5 minutes, keeping the electrode temperature at 70ยฐ C. results in the dashed curve 614 . The ablation radius in this case has moved out to approximately 12 millimeter radius or 24 millimeters diameter. Similar measurements with an electrode surface temperature of 80ยฐ C. are shown by curve 624 , corresponding to an ablation diameter of approximately 28 to 30 millimeters for a three minute RF heating, and 30 millimeters for a heating time of 5 minutes, curve 630 . Curves 641 and 660 are extrapolations for electrode surface temperatures of 90ยฐ C. and 100ยฐ C., respectively, corresponding to three-minute treatment time, and curves 644 and 677 , respectively, corresponding to five-minute RF treatments. It is possible to achieve an equivalent ablation radius by different combinations of electrode radius, electrode surface temperature, and the time duration of the RF treatment.
[0085] Electrode examples described above are of conductive, exposed metallic rings disposed on the surface of a flexible catheter. Such rings can be extremely thin and non-cooled to achieve an effective clinical result, and can be of a variety of materials, including stainless steel, titanium, cobalt or nickel alloys, or plated copper. Other materials can be used that are embedded in or adhered to the underlying substrate of the catheter including conductive plastics, conductive silicone sheets, braided wire structures that are embedded into the plastic substrate of the catheter, circumferential wires, helices, longitudinal wires, conductive foils or films, meshes of wire, and other variations. The RF electrode structures can have desirable properties for imaging, for example, roughened, etched, pitted, or sand blasted surfaces to enhance echo-genicity for ultrasonic imaging, low-density material for CT or X-ray images to give appropriate contrast relative to anatomy, MRI-suitable material such as titanium, aluminum, cobalt or nickel alloys, copper, or other conductors or metals that enable visualization without artifact in MRI images.
[0086] Electrical connections can be made in the monopolar, bipolar, or multi-polar arrangements with the external RF generator to achieve a variety of electric field and current patterns around the RF electrodes, and thus achieve variations in heating patterns around or between the electrodes. For a bipolar arrangement, the heating pattern tends to be more intense in the gap between the electrode and less intense towards the extreme end regions of the electrodes. The gap between the electrodes could thus be widened into the ranges of 5 to 10 millimeters, 10 to 15 millimeters, or 20 or more millimeters.
[0087] Referring again to FIG. 8, an elderly patient has been treated with a catheter/electrode system similar to that shown in FIG. 8. The patient had been in retention (could not urinate) for over six months, and was required to have an indwelling drainage catheter in his urethra during that period. Because he had severe heart and lung problems, TURP surgery was not indicated. A 20 French, flexible silicone balloon catheter with two 15 millimeter long stainless steel rings with outer diameters of approximately 7.7 millimeters secured to the exterior surface of the catheter was used in the procedure. The gap PG 8 between the ring 420 and balloon 423 was 2 millimeters. The length of insulation band 444 was 5 millimeters. The gap G 8 between the rings was 4 millimeters. Initially, the exposed portion EL 24 was 5 millimeters, and the two separate insulative bands 456 and 460 were each 5 millimeters long. Thermocouple thermal sensors were roughly in the positions 424 and 452 . Based on the length of the patient's prostate and other considerations, the insulation band 444 was kept on ring 420 so as to preserve the bladder neck. Second ring 430 was activated in a sequential manner, and the insulation 456 was removed so that the total exposed electrode for the second ring 430 was 10 millimeters.
[0088] RF heating with ring 420 at 70ยฐ C. was performed for three minutes. Subsequently, RF heating with ring 430 at 70ยฐ C. was performed for 3 minutes. The RF generator monitored the RF power output, the temperature associated with each ring, and the impedance of the electrodes to be sure they were in reasonable parameters before RF power was delivered. No general anesthesia was required. After removal of the catheter, the patient was sent home that day with a standard drainage catheter in place. Two weeks later the drainage catheter was removed, and the patient was able to void (urinate) voluntarily and freely for the first time in over six months. Signs of necrotic prostatic tissue was observed in his urine, indicating that the tissue in the ablated volume that had been killed by the RF heating had disintegrated and was being flushed out as debris in the patient's urine stream.
[0089] Referring to FIG. 15, the procedure starts by determining the relevant dimensions of the prostate, and/or the prostatic urethra, and/or any irregularities of the urethra such as strictures, obstructions, and/or the diameter of the urethra, and/or the geometry of the urethral path, including irregularities (step 691 ). For example, the length of the prostatic urethra from the verumontanum to the bladder neck can be determined by various imaging and diagnostic methods, including an endoscope or urethroscope inserted into the urethra to directly observe the length, CT or MR imaging, X-ray imaging contrast, or trans-urethral ultrasound. The anterior-to-posterior size of the prostate in circumference or volume can be made in step 691 . Step 691 can also include clinical decisions as to whether the bladder neck should be preserved according to patient wishes, age, or other considerations. The desired ablation length is then determined.
[0090] The next step is selection of the high frequency electrode configuration and/or adjustment to the electrode configuration based on prostate dimensions and the desired RF ablation volume (step 697 ). For example, in this step, one or several RF electrodes are selected, and the length and diameter of the individual electrodes are selected, with removal of insulative bands if required. The configuration of the catheter is also selected, for example, a flexible urethral catheter having an irrigation aspiration port and a balloon, or a non-balloon catheter, an endoscopic structure with optical viewing, irrigation, aspiration, and manipulation functions and one or more RF electrodes disposed on the surface of the endoscopic probe or projecting forward of the endoscopic probe, as through an inner lumen of the probe.
[0091] The next step is inserting the high frequency probe into the urethra (step 707 ). Urine is flushed from the bladder, and plain water without ionic content is infused into the bladder prior to RF heating. If the catheter has a balloon on its distal end, the balloon is then inflated and the catheter pulled so that the balloon is snugly placed at the bladder neck. Diagnostic imaging can be used to confirm that the catheter, balloon, and/or electrodes are in the proper position, and observation made of index markings on the catheter at the external urethra entrance.
[0092] In step 711 , the application of high frequency power is initiated. In step 714 , for example, the RF electrode temperature, RF power, current, voltage, impedance, and time of power application are monitored before, during, and/or after the RF heating process. Monitoring of impedance of the RF electrode gives an instant check of circuit continuity or any untoward situation that may occur relative to the electrode. In step 717 , the RF ablation parameters and time duration of the RF heating are applied to induce a cavity within the prostate that achieves the desired clinical result.
[0093] Other embodiments are within the scope of the following claims.
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A device for enlarging a urethral passage includes an elongate member having a distal portion configured for intraurethral placement in the urethral passage, and an electrode at the distal portion. The electrode is configured to be energized with high frequency energy to necrose tissue of the urethral wall and surrounding prostate tissue to form a cavity in the urethral passage. The electrode has an adjustable working length. The electrode has a diameter greater than about 16 French to substantially occlude the urethra. The device includes multiple electrodes spaced apart a distance of about 1 to 5 mm to provide flexibility in the distal portion of the elongate member. A method of treating a urethral passage includes measuring a length of a patient's prostate, and selecting a length of an electrode based on the measured length of the prostate.
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RELATED APPLICATIONS
This application is a continuation application of U.S. patent application Ser. No. 14/127,699, filed on Dec. 19, 2013, which is a national stage application under 35 U.S.C. ยง371 of PCT/US2012/043813, filed on Jun. 22, 2012, which claims priority to PCT/US2011/041866 filed Jun. 24, 2011, and U.S. provisional application 61/501,207 filed Jun. 25, 2011, the contents of each are incorporated herein by reference in their entireties.
TECHNICAL FIELD
The field generally relates to organic compounds that act as nicotinic receptor antagonists. The field further relates to the use of nicotinic receptor antagonists for use as a prophylaxis and/or treatment for both small and non-small cell lung cancer, HIV, cognitive disorders, Alzheimer's disease, smoking cessation, Schizophrenia, and mammalian exposure to various neurological toxins.
BACKGROUND OF THE INVENTION
Nicotinic acetylcholine receptors (nAChRs) belong to the Cys-loop subfamily of pentameric ligand-gated ion channels and can be classified into muscle-type and neuronal subtypes. The neuronal nAChRs comprise twelve subunits (ฮฑ2-ฮฑ10 and ฮฒ2-ฮฒ4) with different arrangements, while the muscle-type is consisted of four subunits in a single arrangement of ฮฑ1ฮณฮฑ1ฮฒ1ฮด (ฮณ is replaced by ฮต in the adult). (Lukas, R. J. et al., Pharmacol. Rev. 1999, 51, 397) Two major neuronal receptors ฮฑ4ฮฒ2 and ฮฑ7 have been identified in the central nervous system. (Flores, C. et al., Mol. Pharmacol. 1992, 41, 31; Lindstrom J. et al., Prog. Brain Res. 1996, 109, 125) The neuronal ฮฑ7 nAChR has been proposed as a potential therapeutic target for a broad range of neurodegenerative and psychiatric diseases, including Alzheimer's disease, schizophrenia, anxiety, and epilepsy. A variety of selective partial and full agonists have been developed for the ฮฑ7 nAChR as potential therapeutics. (Jensen A. et al., Prog., Brain Res. 1996) Several ฮฑ7 nAChR selective agonists (e.g., TC-5619 and MEM-3454) have advanced to clinical trials for Alzheimer's disease and schizophrenia. (Arneric, S. P. et al., Biochem. Pharmacol. 2007, 74, 1092; Mazurov A. et al., Curr. Med. Chem. 2006, 13, 1567; Olincy A., Arch. Gen. Psychiatry 2006, 63, 630) Although extensive efforts have been taken to identify selective ฮฑ7 nAChR agonists, the development of ฮฑ7 selective antagonists is relatively limited. Some studies have reported that certain naturally derived compounds may be incorporated as ฮฑ7 selective antagonists. For example, the krait Bungarus multicinctus derived peptide toxin a-bungarotoxin (ฮฑ-BTX) and the seeds of Delphinum isolated nonpetide toxin methyllycaconitine (MLA) are two frequently used ฮฑ7 selective antagonists. (Chang, C. C., et al. J. Biomed. Sci. 1999, 6, 368; Davies, A. R., et al. Neuropharmacology 1999, 38, 679)
Unfortunately, ฮฑ-BTX is a potent antagonist for muscle-type nAChRs as well, and both compounds also inhibit nAChR subtypes ฮฑ9 and ฮฑ9 ฮฑ10. (Jensen, A. A., et. al. J. Med. Chem. 2005, 48, 4705) Nevertheless, subtype-selective antagonists may possess intrinsic value as tools to define the roles played by ฮฑ7 nAChRs in the physiological and pathophysiological processes.
Indeed, and along these same lines, nicotinic acetylcholine receptors have been implicated as possible drug targets in a myriad of various disease states and for use as a possible measure for counter-terrorism purposes.
For example, with regards to various disease states, nAChRs have for some time now been studied in an attempt to find a possible nexus between targeting of the receptor and treatment of small cell lung carcinoma (SCLC). (Sciamanna, J. Neurochem. 69, 2302-2311 1997). While SCLC is a neuroendocrine neoplasm that accounts for a minority of newly diagnosed lung cancers, roughly a quarter, it is quite deadly and patients generally die within a mere year of being diagnosed. Thus, there is a pertinent need for the development of treatments, or means of prophylaxis, that can be administered to a patient in order to mitigate, or achieve complete ablation of, the SCLC disease state.
Despite the attendant need, few, if any, specific treatments are available for SCLC. However, the most current data available in the field indicates that two types of nAChRs can regulate NA and CA influx. Such regulation of calcium and sodium influx has biological and therapeutic ramifications in the treatment of neuroendocrine neoplasms. Thus, in light of the paucity of compounds available that can effectively and specifically target such channels, there still remains a glaring need for rationally based compounds that have the ability to target such receptors.
In addition to developing a more efficacious means for treating SCLC, there is also an attendant need for compounds that may be used to treat the more widespread dilemma of non-small cell lung cancer (NSCLC). In this regard it has been observed that mesothelioma and non-small cell lung cancer express functional nAChR. (Paleari, et al. Int. J. Cancer: 125, 199-211 2009) Thus, there has been speculation that nicotine may play some heretofore-unknown role in contributing to lung cancer pathogenesis via activation of such cellular proliferation pathways as Akt signaling or by inhibiting other natural cellular apoptotic machinery. (Id) However, some studies have indicated that nicotine acts on nAChRs, expressed in NSCLC tumor cells, by activating a proliferative response in such cells. (Id)
Next, despite their distinct disease pathology, it has been discovered that disease states such as cancer and AIDS have a common link via nAChRs. In addition to the need to develop treatments for both small and non-small cell lung cancer, however, there is also a need for compounds or treatment mechanisms that have the ability to effectively combat HIV and AIDS, disease states that also pose a very serious threat to public health worldwide. In fact more than 40 million people are infected worldwide with HIV-1 and an estimated 14,000 new infections occur every day. Since the first cases of AIDS were identified in 1981 the deaths of over 25 million people have been attributed to HIV/AIDS.
As mentioned, alpha-7 nAChRs has been found in lung cancer cells where activation by either natural molecules or compounds in tobacco smoke are shown to promote cancer growth. It has been found that those same alpha-7 nAChRs are upregulated in immune cells in AIDS. This suggests that over activation of alpha-7 receptors in macrophages by the AIDS virus protein, may cause premature cell death. Thus, and at the very least, antagonists to nAChRs are needed to continue to exploit the relationship between cancer, AIDS and nAChR activity, and thus provide treatments for these disease states.
Additionally, nicotinic acetylcholine receptors have been also been implicated to play a role in neurodegenerative diseases and cognitive disease or disoarders. For example, nicotinic acetylcholine receptors have been implicated in disease such as Alzheimer's disease. Buckingham et al., Pharmacological Reviews March 2009 vol. 61 no. 1 39-61. Moreover, ฮฑ7 nAChR have specifically been identified as having some type of role in the etiology and/or pathology of Alzheimer's disease. Jones I W, et al., J Mol Neiuosci. 2006; 30 (1-2):83-4.
Nicotinic acetylcholine receptors have been also been suggested to play a role in certain neurodegenerative and cognitive disorders. The alpha7 nicotinic acetylcholine receptor (nAChR) has been thought of as a target for treatment of cognitive dysfunction associated with Alzheimer's disease and schizophrenia. J Pharmacol Exp Ther. 2009 May; 329(2):459-68. Epub 2009 Feb. 17.
However, despite these suggested links to a number of disparate diseases and disorders, there are attendant issues with nicotinic acetylcholine receptors. For example nicotinic acetylcholine receptors represent a complex and diverse set of receptor subtypes, Additionally, prolonged use may lead to desensitization of the receptor. Papke, et al., Journal of Pharmacology and Experimental Therapeutics , May 2009 vol. 329 no. 2 791-807.
These latter factors have made it difficult to work with nicotinic acetylcholine receptors and to develop compounds that are efficacious both in the short and long term.
SUMMARY OF THE INVENTION
It is an object of the present invention that the novel nicotinic receptor antagonists disclosed herein may be used in a broad array of clinical or medicinal facets. For example, it is a contemplated use of the present invention that the novel nicotinic receptor antagonists be used to inhibit the growth cycle of non-small cell lung cancer cells.
Without being bound by theory, it is an object of the present invention that the nicotinic receptor antagonists disclosed herein are believed to possess reversible antagonists. Moreover, the compounds of the present invention are selective for ฮฑ7 nAChR. For example, the compounds of the present invention are not believed to bind to ฮฑ4 ฮฒ2 nAChR neuromuscular receptors.
It is also contemplated that the nicotinic receptor antagonists of the present invention will be used as a counter measure to treat exposure, or potential exposure, to a wide array of potential neurotoxins. The AChRs are activated by acetylcholine (ACh), which is hydrolyzed to choline by acetylcholineesterase (AChE). When AChE is irreversibly inhibited by organophosphorus nerve agents like DFP and sarin, the uncontrolled accumulation of ACh at peripheral and central muscarinic AChRs (mAChRs) and nAChRs causes the cholinergic syndrome. This syndrome is characterized by sweating, pupillary constriction, convulsions, tachycardia, and eventually death.
The currently acknowledged treatment for nerve agent intoxication is the mAChR antagonist atropine used in concert with an oxime reactivator of AChE (e.g., pralidoxime). However, while this treatment regimen does not directly target nicotinic receptors both mAChRs and nAChRs are involved in nerve agent toxicity. It has been shown that, for example, nAChR antagonists 1i and 2, when tested in a DFP toxicity animal model to investigate their anti-seizure activity, (Peng et al.; Racine, R. J. Electroencephalogr. Clin. Neurophysiol. 1972, 32, 269.) that pretreatment with compounds 1i and 2 antagonized DFP-induced seizure-like behaviors over a 2 h period post-injection by 93.4% and 91.2%, respectively. These results suggest that the compounds of the present invention could provide neuroprotection against seizure-like behaviors induced by DFP and, therefore, may be useful for treatment of organophosphus nerve agent intoxication. Moreover, it is also contemplated that the compounds disclosed herein provide a means of discerning between the physiological roles of neuronal ฮฑ7 nAChR under normal and diseased states, and as diagnostic tools used for discovering potential therapies for organophosphorus nerve agent intoxication.
As well, it is also contemplated that the nicotinic receptor antagonists of the present invention could be used as means for prophylaxis or treatment of HIV and/or AIDS. In a preferred aspect, novel ฮฑ7 nAChR selective antagonists are administered in an effective therapeutic dose causing some measure of reduced symptomology or total ablation of the disease state.
However, while not bound by any theory, it is also believed that while the compounds of the present invention are selective ฮฑ7 nAChR antagonists, that this does not also mean that the compounds activity is overall anticholinergic. Again, while not bound by any theory, it is surprising that these selective antagonists enhance cognition. Without being bound by theory, it is theorized that at lower doses or over extended periods, that the compounds disclosed herein may reduce desensitization in response to acetylcholine, which thereby enhances the effects of endogenous acetylcholine.
In yet another aspect of the present invention the novel nicotinic receptor antagonists disclosed herein could be used to have a protective effect on patients in order to prevent sepsis.
In still another aspect of the present invention the novel nicotinic receptor antagonists disclosed herein could be used, either alone or combination with another pharmaceutical, to treat Alzheimer's disease. It is contemplated that the present invention may also treat the symptoms of Alzheimer's disease. In one aspect it is contemplated the present invention may be used to treat at least one symptom of Alzheimer's disease.
It is contemplated by the present invention that the nicotinic receptor antagonists disclosed herein may also treat at least one symptom of Alzheimer's disease wherein that symptom of Alzheimer's disease relates to cognitive impairment.
In another aspect of the present invention it is contemplated that the novel nicotinic receptor antagonists disclosed herein could be used to treat or prevent relapse of opioid, cocaine, nicotine, and methamphetamine use. For example, it is contemplated that the novel nicotinic receptor antagonists disclosed herein could be used to in treatments directed toward smoking cessation.
In yet another aspect, it is contemplated that the novel nicotinic receptor antagonists disclosed herein could be used to treat and/or improve cognition and/or cognition related diseases or disorders.
It is further contemplated that the compounds of the present invention may be used to treat dementia. In one embodiment the compounds of the present invention may be used to treat psychosis, e.g., in schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, mania or bipolar disorder.
It is also contemplated that the compounds of the present invention may be used to treat cognitive impairment wherein cognitive impairment is a result and/or symptom of psychosis, e.g., in schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, mania or bipolar disorder.
In another aspect of the present invention, it is further contemplated that novel ฮฑ7 nAChR selective antagonists may be used as research or diagnostic tools. It is further contemplated that novel ฮฑ7 nAChR selective antagonists could be used as a research tool in elucidating signal transduction in neuronal tissue. It is also contemplated that novel ฮฑ7 nAChR selective antagonists could be used as a research tool in elucidating signal transduction pathway in non-neuronal tissue as well.
It is further contemplated that the compounds disclosed herein may be used to treat cognitive impairment that is the symptom of a medication used to treat cognitive related disease/disorder, e.g., Alzheimer's disease, schizophrenia.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a depiction of a representative dose response curves of Compound 1 and Compound 2 on the native neuronal alpha-7 nAChR in rat brain membranes.
FIG. 2 is a depiction of the inhibition of human ฮฑ7 AChR responses expressed in Xenopus oocytes.
FIG. 3 is a depiction of the binding selectivity of Compound 1 and Compound 2.
FIG. 4 a and FIG. 4 b depict brain and plasma concentrations for Compounds 1 and 2, respectively.
FIG. 5 demonstrates the alpha-7 selective ligands that may be used for pharmacophore development.
FIG. 6 depicts a six-point pharmacophore model may be obtained based on the unified scheme within MOE.
FIG. 7 a depicts the results of the Novel Object Recognition test wherein the compound was administered 15 min prior to the first trial.
FIG. 7 b depicts the results of the Novel Object Recognition test wherein the compound was administered 1 hour following the first trial.
DETAILED DESCRIPTION OF THE INVENTION
The examples provided in the detailed description are merely examples, which should not be used to limit the scope of the claims in any claim construction or interpretation.
The present invention contemplates nicotinic acetylcholine receptor antagonists of Formula I:
Wherein R 1 may be a benzyl, phenethyl, 2-methoxyethyl, isobutyl, or cyclopentyl group.
Wherein R 2 may be a hydrogen or methyl group.
Wherein R 3 may be a chlorine, methoxyethyl, methyl, flourine or cyclopentyl group.
The present invention contemplates nicotinic acetylcholine receptor antagonists of Formula II:
Wherein R 1 may be a benzyl, methyl, or hydrogen group.
Wherein R 2 may be a propyl, methyl, cyclopropyl, and 4-tolyl group.
Wherein R 3 may be a hydrogen, fluorine, chlorine, or furyl group.
The treatment of patients with the novel ฮฑ7 nAChR selective ligands as described above addresses the immediate, and increasing, need for safer and more efficacious compounds to treat patients who suffer from diseases or disorders correlated with the activation of the nicotinic acetylcholine receptors pathways associated with the aforementioned disease states.
Accordingly, the present invention provides Method I for the treatment or prophylaxis of a disease or disorder characterized by the activation of an acetylcholine receptor pathway, comprising administering to the patient an effective amount of a ฮฑ7 nicotinic acetylcholine receptor antagonists according to Formula I or Formula II in a free or pharmaceutically acceptable salt form, for example:
1.1 Method I, wherein said disease or disorder is small cell lung cancer. 1.2 Method I wherein said disease or disorder is non-small cell lung cancer. 1.3 Method I, wherein said disease or disorder is organophosphorus nerve agent intoxication 1.4 Method I, wherein said disease or disorder is infection via the human immunodeficiency virus (HIV). 1.5 Method I, wherein said disease or disorder is the result of autoimmune deficiency syndrome (AIDS). 1.6 Method I, or any of methods 1.1-1.5, wherein the patient is a human. 1.7 Method I, or any of methods 1.1-1.2, wherein the disease or disorder is characterized by metastatic cancerous cells. 1.8 Method I, or any of methods 1.1-1.2, wherein the disease or disorder is characterized by benign cancerous cells. 1.9 Method I, or any of methods 1.1-1.2, 1.7, 1.8, wherein said disease or disorder characterized by the presence of cancerous cells may be selected from the following group of diseases or disorders: squamous cell carcinoma, adenocarcinoma, large cell carcinoma, and pleuroa mesothelioma. 1.10 Method I, or any of methods 1.1-1.2, 1.7-1.9, wherein said disease or disorder is a solid tumor carcinoma. 1.11 Method I, or any of methods 1.1-1.2, 1.7-1.10, wherein a patient is suffering from or at risk for developing cancer. 1.12 Method I, or any of methods 1.1-1.2, 1.7-1.10, wherein a novel ฮฑ7 nicotinic acetylcholine receptor antagonist of Formula I is administered simultaneously with a second treatment for cancer selected from the group consisting of: capecitabine, trastuzumab, pertuzumab, cisplatin and irinotecan. 1.13 Method I, wherein the disease or disorder is a cognitive impairment and/or a disease or disorder related to cognitive impairment. 1.14 Method I or 1.13, wherein the cognitive related disease or disorder is mild cognitive impairment. 1.15 Method I or 1.13-1.14, wherein the ฮฑ7 nicotinic acetylcholine receptor antagonists according to Formula I or Formula II are used to treat at least one of the symptoms of cognitive impairment, e.g. impaired auditory processing and attention, impaired spatial organization, impaired verbal learning, impaired semantic and verbal memory, impaired executive functions. 1.16 Method I or any of 1.13-1.15 wherein the disease or disorder is Alzheimer's disease. 1.17 Method I or any of 1.13-1.16, wherein the effective amount of an ฮฑ7 nicotinic acetylcholine receptor antagonist is used to treat at least one symptom of Alzheimer's disease. 1.18 Method I or 1.17, wherein the symptom of Alzheimer's disease is cognitive impairment, e.g., impaired auditory processing and attention, impaired spatial organization, impaired verbal learning, impaired semantic and verbal memory, impaired executive functions. 1.19 Method I, wherein the treatment is directed toward smoking cessation in a patient. 1.20 Method I or any of methods 1.13-1.15 wherein the ฮฑ7 nicotinic acetylcholine receptor antagonist is used to treat psychosis, e.g., in schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, mania or bipolar disorder. 1.21 Method I, or 1.20, wherein the cognitive impairment is a symptom of the psychosis, e.g., schizophrenia, schizoaffective disorder, schizophreniform disorder, psychotic disorder, delusional disorder, mania or bipolar disorder. 1.22 Method I or 1.20, 1.21, wherein the cognitive impairment is any of the following, e.g., impaired auditory processing and attention, impaired spatial organization, impaired verbal learning, impaired semantic and verbal memory, impaired executive functions. 1.23 Method I or any of the preceding methods wherein the patient is administered an effective amount of an ฮฑ7 nicotinic acetylcholine receptor antagonist according to Formula I. 1.24 Method I or any of the preceding methods wherein the patient is administered an effective amount of an ฮฑ7 nicotinic acetylcholine receptor antagonist according to Formula II. 1.25 Method I, or any the preceding methods, wherein a patient is administered an effective amount of a novel ฮฑ7 nicotinic acetylcholine receptor antagonist of Formula I in a pharmaceutically acceptable carrier. 1.26 Method I, or any of the preceding methods, wherein administration of an effective amount of an novel ฮฑ7 nicotinic acetylcholine receptor antagonist of Formula I or II improves cognition. 1.27 Method I, or any of the preceding methods, wherein the administration of an effective amount of an novel ฮฑ7 nicotinic acetylcholine receptor antagonist of Formula I or II is used to treat Alzheimer's disease and/or a symptom of Alzheimer's disease. 1.28 Method I, or any of the preceding methods, wherein the administration of an effective amount of an novel ฮฑ7 nicotinic acetylcholine receptor antagonist of Formula I or II is used to treat schizophrenia and/or a symptom of schizophrenia. 1.29 A pharmaceutical composition comprising a compound according to claim 1 or 2 in admixture with a pharmaceutically acceptable diluent or carrier.
In accordance with this detailed description, the following abbreviations and definitions apply. It must be noted that as used herein, the singular forms โaโ, โandโ, and โtheโ include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to โa compoundโ includes a plurality of such compounds and reference to โthe dosageโ includes reference to one or more dosages and equivalents thereof known to those skilled in the art, and so forth.
The term โtreatingโ, โtreatmentโ, and the like are used herein to generally mean obtaining a desired pharmacological and physiological effect. The novel ฮฑ7 nAChRs described herein which are used to treat a subject with cancer generally are provided in a therapeutically effective amount to achieve any one or more of the following: inhibited tumor growth, reduction in tumor mass, loss of metastatic lesions, inhibited development of new metastatic lesions after treatment has started, or reduction in tumor such that there is no detectable disease (as assessed by, e.g., radiologic imaging, biological fluid analysis, cytogenetics, fluorescence in situ hybridization, immunocytochemistry, colony assays, multiparameter flow cytometry, or polymerase chain reaction). The term โtreatmentโ, as used herein, covers any treatment of a disease in any mammal, particularly a human, known to those that are skilled in the art.
The term โsubjectโ or โpatientโ as used herein is meant to include a mammal. In a preferred aspect of the present invention the mammal is a human. In another preferred aspect of the present invention the mammal is a domestic animal.
The term โpharmaceutically effectiveโ as used herein refers to the effectiveness of a particular treatment regime. Pharmaceutical efficacy can be measured based on such characteristics, for example, as inhibition of tumor growth, reduction of tumor mass or rate of growth, lack of detectable tumor associated antigens, and any other diagnostic measurement tool that is known in the field. Pharmaceutical efficacy can also be measured based on such characteristics, for example, as inhibition of the HIV virus and/or reduction and eradication of AIDS related symptoms. Moreover, pharmaceutical efficacy can also be measured based upon the reduction of the onset of symptoms that are related to the induction of organophosphorus nerve agent intoxication.
By โpharmaceutically effective amountโ as used herein refers to the amount of an agent, reagent, compound, composition, or combination of reagents disclosed herein that when administered to a mammal that are determined to be sufficiently effective against cancer that is the object of the treatment or HIV/AIDS. A pharmaceutically effective amount will be known to those skilled in the art.
By the term โtumorโ is meant to include both benign and malignant growths or cancer. The term โcancer,โ is meant to encompass, unless otherwise stated, both benign and malignant growths. In preferred aspects of the invention the tumor referred to is malignant. The tumor can be a solid tissue tumor such as a melanoma, or a soft tissue tumor such as a lymphoma, a leukemia, or a bone cancer. By the term โprimary tumorโ is meant the original neoplasm and not a metastatic lesion located in another tissue or organ in the patient's body. By the terms โmetastatic disease,โ โmetastases,โ and โmetastatic lesionโ are meant a group of cells which have migrated to a site distant relative to the primary tumor.
By โAIDSโ is meant HIV infection: AIDS, ARC (AIDS related complex), both symptomatic and asymptomatic, and actual or potential exposure to HIV. Accordingly, the treatment of AIDS refers to the inhibition of HIV virus, the prophylaxis or treatment of infection by HIV and the prophylaxis, treatment or the delay in the onset of consequent pathological conditions such as AIDS. The prophylaxis of AIDS, treating AIDS, delaying the onset of AIDS, the prophylaxis of infection by HIV, or treating infection by HIV is defined as including, but not limited to, treatment of a wide range of states of HIV infection: AIDS, ARC (AIDS related complex), both symptomatic and asymptomatic, and actual or potential exposure to HIV.
The term โnicotinic acetylcholine receptorโ refers to the endogenous acetylcholine receptor having binding sites for acetylcholine which also bind to nicotine. The term โnicotinic acetylcholine receptorโ includes the term โneuronal nicotinic acetylcholine receptor.โ
The terms โsubtype of nicotinic acetylcholine receptor,โ and โnicotinic acetylcholine receptor subtypeโ refer to various subunit combinations of the nicotinic acetylcholine receptor, and may refer to a particular homomeric or heteromeric complex, or multiple homomeric or heteromeric complexes.
The term โagonistโ refers to a substance which interacts with a receptor and increases or prolongs a physiological response (i.e. activates the receptor).
The term โpartial agonistโ refers to a substance which interacts with and activates a receptor to a lesser degree than an agonist.
The term โantagonistโ refers to a substance which interacts with and decreases the extent or duration of a physiological response of that receptor.
The terms โdisorder,โ โdisease,โ and โconditionโ are used inclusively and refer to any status deviating from normal.
The term โcentral nervous system associated disordersโ includes any cognitive, neurological, and mental disorders causing aberrant or pathological neural signal transmission, such as disorders associated with the alteration of normal neurotransmitter release in the brain.
EXAMPLES
Example 1
The structures of Compound 1 and 2 were confirmed by UPLC-HRMS and found to have purities of 98% and 97%. Several analogs of Compounds 1 and 2, with different substitutions at positions of R1, R2, R3, and R4, were identified by substructure searches or chemical synthesis (Tables 1 and 2). Structure-activity relationships (SARs) were developed for both compounds using the binding assay. For example, substitution (e.g., methyl and chlorine) at R3 is tolerated for analogs of Compound 1. Both benzyl (1i) and isobutyl (1k) at R1 were more favorable than the more flexible phenethyl (1 d).
For analogs of Compound 2, a bulky benzyl group at R1 yielded more potent receptor binding than a less bulky methyl or free base (2 vs 2h and 2i). More hydrophobic substitutions at R3 improved receptor binding (2f vs 2h). The R4 position tolerated different substitutions (e.g., hydrogen and halogen).
TABLE 1
Percent inhibition at
R 1
R 2
R 3
10 ฮผM a (mean ยฑ SD)
Benzyl
H
3-Cl
83.0 ยฑ 1.7
Benzyl
H
70.5 ยฑ 3.1
Phenethyl
H
4-OMe
โ9.5 ยฑ 3.7
2-Methoxyethyl
H
4-Cl
27.3 ยฑ 0.7
Phenethyl
H
2-Cl
23.4 ยฑ 2.4
Isobutyl
Methyl
2,5-F,F
59.2 ยฑ 0.2
Phenethyl
H
4-Cl
18.3 ยฑ 1.3
Cyclopentyl
H
2-Cl
21.6 ยฑ 2.6
2-Methoxyethyl
Methyl
2-Cl
43.0 ยฑ 0.0
Benzyl
Methyl
2-Cl
79.7 ยฑ 1.9
Phenethyl
H
2-Me
25.2 ยฑ 1.8
Isobutyl
Methyl
2-Cl
72.3 ยฑ 1.0
Table 1 of Example 1 details binding affinity of nicotinic acetylcholine receptor antagonists, determined by radiolabeled binding, according to Formula I for the native ฮฑ7 nAChR in rat brain membranes at 10 ฮผM. Nicotinic acetylcholine receptor antagonists according to Formula I are listed as follows (from top to bottom): Compound 1, Compound 1a, Compound 1b, Compound 1c, Compound 1d, Compound 1e, Compound 1f, Compound 1g, Compound 1h, Compound 1i, Compound 1j, and Compound 1k.
The binding affinity of these compounds for the native ฮฑ7 nAChR in rat brain membranes was measured at 10 ฮผM using [ 125 I] ฮฑ-BTX as the radioligand. Non-Specific binding was determined with 1 ฮผM MLA.
TABLE 2 Percent inhibition R 1 R 2 R 3 R 4 at 10 ฮผM* (Mean ยฑ SD) Benzyl H Propyl H 83.8 ยฑ 2.3 Benzyl H Methyl 4-F 50.0 ยฑ 2.0 Benzyl H Methyl 4-Cl 64.1 ยฑ 1.8 Methyl Methyl Methyl 4-F 11.9 ยฑ 2.3 Methyl Methyl Methyl 4-Cl 13.5 ยฑ 5.3 Methyl Methyl Cyclopropyl 2-Furyl 10.5 ยฑ 1.7 Methyl H 4-Tolyl H 23.4 ยฑ 0.8 Methyl Methyl 4-Tolyl H 12.1 ยฑ 1.3 Methyl H Propyl H โ3.1 ยฑ 0.1 H H Propyl H โ1.0 ยฑ 2.8
Table 2 details binding affinity of nicotinic acetylcholine receptor antagonists, determined by radiolabeled binding, according to Formula II for the native ฮฑ7 nAChR in rat brain membranes at 10 ฮผM. Nicotinic acetylcholine receptor antagonists according to Formula II are listed as follows (from top to bottom): Compound 2, Compound 2a, Compound 2b, Compound 2c, Compound 2d, Compound 2e, Compound 2f, Compound 2g, Compound 2h, and Compound 2i.
The binding affinity of these compounds for the native ฮฑ7 nAChR in rat brain membranes was measured at 10 ฮผM using [ 125 I] ฮฑ-BTX as the radioligand. Non-Specific binding was determined with 1 ฮผM MLA.
Example 3
Binding assay was performed according to the previously reported method noted in Meyer, E. M.; Kuryatov, A.; Gerzanich, V.; Lindstrom, J.; Papke, R. L. J. Pharmacol. Exp. Ther. 1998, 287, 918. using [125I]ฮฑ-BTX as the radioligand. 28 IC50 of Compound 1=1.61M; IC50 of Compound 2=2.91V. Dose-response curves of compounds 1 and 2 on the native neuronal ฮฑ7 nAChR in rat brain membranes. The error bars indicate the standard deviation of the measurements. FIG. 1 details a representative dose response curves of Compound 1 and Compound 2 on the native neuronal alpha-7 nAChR in rat brain membranes. The line containing square-point designations indicates percent inhibition results regarding Compound 1, while the line containing triangle-point designations indicates the results regarding Compound 2.
Example 4
The functional activity of compounds 1, 1i, and 2 is determined by electrophysical experiments on Xenopus oocytes expressing human alpha-7 nAChR. Human alpha-7 nAChR may be expressed in Xenopus oocytes by any means to known in the field. These three compounds are found to inhibit acetylcholine-evoked receptor responses in a dose-dependent manner, suggesting the subject compounds are ฮฑ7 nAChR antagonists. The IC50 values of 1, 1i, and 2 are 11.9 ฮผM, 3.7 ฮผM, 18.9 ฮผM, respectively. The ฮฑ7 functional potency was 6-8 fold lower than the affinity estimated from human ฮฑ7 receptor binding, without being bound by any theory, this difference may come from interspecies variation (rat vs. human), or variability in receptors (native vs. recombinant), or due to technical aspect of the functional assay in the oocyte expression system. FIG. 2 illustrates the inhibition of human ฮฑ7 AChR responses expressed in Xenopus oocytes. The line containing solid square-point designations indicates percent inhibition results regarding Compound 1, while the line containing triangle-point designations indicates the results regarding Compound 2. The line containing hollow square-point designations indicates results regarding Compound 1i.
Example 5
The binding selectivity of Compound 1 and Compound 2 can be seen in FIG. 3 . Compound 1 is represented by the solid bar while Compound 2 is represented by the empty bar. The selectivity of compounds 1 and 2 were measured using previously reported methods on three other receptors: neuronal ฮฑ4ฮฒ2 nAChRs, muscle-type nAChRs, and 5HT3 receptors. The binding affinity for the ฮฑ4ฮฒ2 receptor was performed on rat cortical membranes using [ 3 H]epibatidine as the radioligand. The muscle-type nAChR binding was determined using human TE671 cells with [ 125 I] ฮฑ-BTX as the radioligand. 5HT3 binding was measured on recombinant CHO cells expressing human 5HT3 receptor using [ 3 H]BRL 43694 as the radioligand. The orthosteric binding sites of the ฮฑ7 nAChR and the 5HT3 receptor share a high degree of homology, therefore ligands for ฮฑ7 nAChR and 5HT3 ligands frequently exhibit cross-activity. At 10 IM, compound 1 exhibited 82.5% binding to the ฮฑ7 receptor and 18.8% and 8.4% binding to the neuronal ฮฑ4ฮฒ2 and the 5HT3 receptor, respectively. Similarly, compound 2 showed binding affinities of 82.5% to ฮฑ7, 1.3% to ฮฑ4ฮฒ2, and 14.3% to 5HT3. Meanwhile, both compounds exhibited no detectable binding to the muscle-type nAChR at 10 ฮผM. Taken together, these results demonstrated the selectivity of compounds 1 and 2 for the 5HT3receptor over ฮฑ4ฮฒ2, muscle-type nicotinic, and 5HT3 receptors The selectivity of compounds 1 and 2 was performed using methods previously discussed in Hope, A. G.; Peters, J. A.; Brown, A. M.; Lambert, J. J.; Blackburn, T. P. Br. J. Pharmacol. 1996, 118, 1237; Lukas, R. J. J. Neurochem. 1986, 46, 1936; Perry, D. C.; Kellar, K. J. J. Pharmacol. Exp. Ther. 1995, 275, 1030.
Example 6
Compounds 1i and Compound 2 were tested in male C57B1/6 mice (n 3 per time point) for blood brain barrier after cassette dosing at 10 mg/kg via intraperitoneal (ip) administration. Brain and blood samples were collected at specific time points after drug administration. The area under the curve (AUC) ratios of brain to plasma were 2.8 and 3.1 for Compound 1i ( FIG. 4 a ) and Compound 2 ( FIG. 4 b ), respectively, suggesting good brain penetration for both compounds. Compound 2 achieved high concentration in brain (9 ฮผM). Cassette dosing of compounds can lead to incorrect estimates of plasma drug levels by drug-drug interactions such as at the level of Cytochrome P450 enzymes or by interfering with transporter systems. Without being bound by theory, the biphasic nature of the drug plasma and brain levels would suggest some type of secondary uptake mechanism as is seen for drugs that are eliminated from the blood in part by the bile system and therefore available in the intestine to be taken up into the circulation a second time.
Example 7
Seizure score
Normalized
Normalized
(Mean ยฑ SD)
% seizure
% neuroprotection
0 ยฑ 0
0
100
9.1 ยฑ 6.4
100
0
0.6 ยฑ 1.3
6.8
93.4
0.8 ยฑ 1.3
8.8
91.2
The table of Example 7 illustrates the neuroprotective activities of Compound 1i and Compound 2 against seizure induced by the nerve agent diisopropylfluorophosphate (DFP). The acetylcholine receptors (AChRs) are activated by acetylcholine (ACh), which is hydrolyzed to choline by acetylcholineesterase (AChE). When AChE is irreversibly inhibited by organophosphorus nerve agents like DFP and sarin, the uncontrolled accumulation of ACh at peripheral and central muscarinic AChRs (mAChRs) and nAChRs causes the cholinergic syndrome. This syndrome is characterized by sweating, pupillary constriction, convulsions, tachycardia, and eventually death. The mainstay treatment for nerve agent intoxication is the mAChR antagonist atropine together with an oxime reactivator of AChE (e.g., pralidoxime). This treatment regimen does not directly target nicotinic receptors although both mAChRs and nAChRs are involved in nerve agent toxicity. In this study, the new nAChR antagonists, Compounds 1i and 2 were tested in a DFP toxicity animal model to investigate their anti-seizure activity. Compared with the DFP controls, pretreatment with Compounds 1i and 2 antagonized DFP-induced seizure-like behaviors over a 2 h period post-injection by 93.4% and 91.2%, respectively. The results suggest that these compounds could provide neuroprotection against seizure-like behaviors induced by DFP and, therefore, may be useful for treatment of organophosphus nerve agent intoxication.
In summary, pharmacophore-based virtual screening led to the discovery of novel ฮฑ7 nAChR ligands. A battery of property and functional group filters were applied to eliminate non-drug-like molecules and to reduce false positives. Two distinct families of small molecules (e.g., Compounds 1i and 2) were identified as novel ฮฑ7 nAChR antagonists with selectivity for the neuronal ฮฑ7 subtype over other nAChRs and good brain penetration. Neuroprotection against the seizure-like behaviors induced by DFP were observed for these compounds in a mouse model. The compounds should be very useful in discerning the physiological roles of neuronal ฮฑ7 nAChR under normal and diseased states, and in discovering potential therapies for organophosphorus nerve agent intoxication.
Example 8
FIG. 5 demonstrates the alpha-7 selective ligands that may be used for pharmacophore development.
Three dimensional (3D) pharmacophore models may be developed and, subsequently conducted ligand-based virtual screening may also be conducted to search for novel ฮฑ7 nAChR selective ligands. Here, six potent and selective ฮฑ7 ligands are representative of a selected training set for the pharmacophore model. The structures of all compounds could be protonated at physiological conditions (pH 7.4). Flexible structural alignments may be performed to identify the common chemical features responsible for the ฮฑ7 receptor binding using the Flexible Alignment module within MOE. This alignment method uses a stochastic search algorithm to simultaneously explore the conformation space of all compounds in the training set.
This operation generates several scores to quantify the quality of each alignment with lower scores indicating better alignments. The alignments with the lowest S score may be selected for the 3D pharmacophore development. A six-point pharmacophore model may be obtained based on the unified scheme within MOE ( FIG. 6 ). Feature F1 is a hydrogen bond acceptor with radius 1.5 โซ. Feature F2 is a cation atom (radius: 1 โซ)โthe basic nitrogen, which exists in most known nAChR ligands. Features F3 and F4 are characterized as aromatic rings with radius 1.5 โซ. Features F5 and F6 cover hydrophobic regions (radius: 1.0 โซ). The pharmacophore model may be used to screen compounds assembled from different sources. In order to remove unwanted structures and accelerate the process of virtual screening, extended Lipinski's rules 22 and three functional group filters were applied before the pharmacophore-based database searching. Extended Lipinski's rules include seven filters: 100<molecular weight โฆ500_2โฆC log Pโฆ5, number of hydrogen bond donors โฆ5, number of hydrogen bond acceptors โฆ10, topological polar surface area โฆ120 A2, number of rings โฆ5, and number of rotable bonds โฆ10. These property filters may be chosen to eliminate compounds that lacked sufficient drug-like properties to become drugs. Compounds that passed the above criteria are subjected to three functional group filters: absence of reactive groups, number of non-fluorine halogen atoms โฆ4, and number of basic nitrogen atoms P1. Reactive groups are defined according to the Oprea set, including heteroatom-heteroatom single bonds, acyl halides, sulfonyl halides, perhalo ketone, and Michael acceptors. These groups can interfere with high-throughput biochemical screening assays and therefore often appear as false positives. A halogen filter may be used to avoid pesticides that often contain a nitrogen atom protonated at physiological conditions (pH 7.4) and this nitrogen atom has been shown to be involved in extensive cation-p interactions between ligand and receptor.
A basic nitrogen filter may be selected to remove compounds that lack this chemical feature. This filter greatly reduced the size of the compound database and therefore improved the speed of conformer generation and pharmacophore matching. Altogether, compounds violating P2 Lipinski's rules or any functional group filters were eliminated from our selection. The resulting compounds are subjected to conformation sampling using the Conformational Import Module, a high-throughput method to generate 3D low-energy conformers in MOE. Recent studies revealed that this method performed as well as the established Catalyst FAST module. The ensemble of conformers were then screened by the six-point pharmacophore model by enabling exact match of features F1-F4 and partial match of features F5 and F6. The consequent hits were subjected to database diversity and clustering analyses with the aim to remove close analogs and maximize the chemotypes of the selected compounds for biological tests. The MDL MACCS fingerprints implemented in MOE are calculated for all compounds and fingerprints-based clustering may be carried out by using the Tanimoto coefficient (0.85) as a measure of fingerprint similarity. No more than three representative compounds in the same cluster are selected for the final collection.
About 300 compounds are acquired from different commercial sources for in vitro biological screening, including compounds from Maybridge, Chembridge, Enamine. The binding affinity of these compounds for the native ฮฑ7 nAChR in rat brain membranes are measured using methods known in the art, particularly with [125I] ฮฑ-BTX as the radioligand. From the preliminary screening, various chemotypes are found to exhibit P50% inhibition on the ฮฑ7 nAChR in this assay. Two of them (compound 1 and 2, Tables 1 and 2 in Examples 1 and 2 disclosed herein) exhibit low micromolar inhibition on brain ฮฑ7 nAChR with an IC50 of 1.6 ฮผM and 2.904, respectively ( FIG. 3 ). The structures of 1 and 2 are confirmed by UPLC-HRMS and found to have purities of 98% and 97%. Several analogs of 1 and 2 with different substitutions at positions of R1, R2, R3, and R4 are identified by substructure searches or chemical synthesis (Tables 1 and 2 in examples 1 and 2 disclosed herein). Structure-activity relationships (SARs) are developed for both compounds using the binding assay. For example, substitution (e.g. methyl and chlorine) at R3 is tolerated for analogs of compound 1. Both benzyl (1i) and isobutyl (1K) at R1 were more favorable than the more flexible phenethyl (1 d). For analogs of compound 2, a bulky benzyl group at R1 yielded more potent receptor binding than a less bulky methyl or free base (2 vs 2h and 2i). More hydrophobic substitutions at R3 improved receptor binding (2f vs 2h). The R4 position tolerated different substitutions (e.g. hydrogen and halogen).
Details of Examples 1-8 are disclosed in Peng et al., โDiscovery of novel ฮฑ7 nicotinic receptor antagonistsโ Bioorganic & Medicinal Chemistry Letters 20 (2010) 4825-4830, the contents of which are incorporated herein by reference in its entirety.
Example 9
Animals were housed in individual standard cages on sawdust bedding in an air-conditioned room (about 20ยฐ C.). They were kept under a 12/12 h light/dark cycle (lights on from 19.00 to 07.00) and had free access to food and water. Rats were housed and tested in the same room. A radio, which was playing softly, provided background noise in the room. All testing was done between 09.00 and 17.00 hours.
Compound 1i was tested at 0, 0.3, 1, and 3 mg/kg in a time-dependent memory deficit model, i.e. a 24 h inter-trial interval (See, FIG. 7 a ). Compound 1i was administered by intraperitoneal injection (i.p. injection), 15 minutes before the first trial. The order of the treatments was balanced to prevent the data from being distorted by potential object- and side-preferences of the animals.
The object recognition test was performed as described elsewhere (e.g., Ennaceur and Delacour, 1988). The apparatus consisted of a circular arena, 83 cm in diameter. The back-half of the about 40 cm high arena wall was made of gray polyvinyl chloride, the front-half consisted of transparent polyvinyl chloride. The light intensity was equal in the different parts of the apparatus, as fluorescent red tubes provided a constant illumination of about 20 lux on the floor of the apparatus. Two objects were placed in a symmetrical position at about 10 cm from the wall, on a diameter from the left- to the right-side of the arena. Each object was available in triplicate. Four different sets of objects were used. The different objects were: 1) a cone consisting of a gray polyvinyl chloride base (maximal diameter 18 cm) with a collar on top made of aluminum (total height 16 cm), 2) a standard 1 L transparent glass bottle (diameter 10 cm, height 22 cm) filled with water, 3) a massive metal cube (10.0ร5.0ร7.5 cm) with two holes (diameter 1.9 cm), and 4) a solid aluminum cube with a tapering top (13.0ร8.0ร8.0 cm). Rats were unable to displace the objects.
A testing session consisted of two trials. The duration of each trial was 3 min During the first trial (T1) the apparatus contained two identical objects (samples). Rats were placed in the apparatus facing the wall at the middle of the front (transparent) segment. After the first exploration period the rat was put back in its home cage. Subsequently, after a 24 h delay interval, the rat was put in the apparatus for the second trial (T2). The total time an animal spent exploring each object during T1 and T2 was recorded manually with a personal computer.
Exploration was defined as follows: directing the nose to the object at a distance of no more than 2 cm and/or touching the object with the nose. Sitting on the object was not considered as exploratory behavior. A minimal amount of object interaction is required in order to achieve reliable object discrimination, therefore rats that explored less than 7 s in T1 and/or 9 s in T2 were excluded from the analyses. In order to avoid the presence of olfactory cues the objects were always thoroughly cleaned after each trial. All object combinations as well as the location (left or right) of the novel object were used in a balanced manner to avoid potential biases due to preferences for particular locations or objects.
In several studies it was shown that Wistar rats show a good object memory performance when a 1 h delay is interposed between the first trial and the second trial. However, when a 24 h delay is used rats do not discriminate between the novel and the familiar object in the second trial, indicating that the rats do not remember the object that was presented in the first trial. Using a 6 h delay, the discrimination performance is in-between than of the 1 h and 24 h delays, suggesting a delay-dependent forgetting in this task. In the first two weeks, the animals were handled daily and were allowed to get accustomed to the test setup in two days, i.e. they were allowed to explore the apparatus (without any objects) twice for 3 min each day. Then the rats were adapted to the testing routine until they showed a stable discrimination performance, i.e. good discrimination at 1 h interval and no discrimination at twice for 3 min each day. Then the rats were adapted to the testing routine until they showed a stable discrimination performance, i.e. a good discrimination at 1 h interval and no discrimination at. In FIG. 5 a , Compound 1i was injected i.p. 15 before T1 and a 24 h inter-trial interval was used.
The basic measures were the times spent by rats in exploring an object during T1 and T2. The time spent in exploring the two identical samples will be represented by โa1โ and โa2โ. The time spent in T2 in exploring the sample and new object will be represented by โaโ and โbโ, respectively. The following variables were calculated: e1=a1+a2, e2=a+b, and d2=(bโa)/e2. E1 and e2 are measures of the total exploration time of both objects during T1 and T2 respectively. d2 is a relative measure of discrimination corrected for exploration activity in the test-trial (e2). Thus, even if a treatment would affect exploratory behavior the d2 index will be comparable between conditions.
As seen in FIG. 5 a , the relative cognitive score (d2) showed a progressive increase up to 1.0 mg/kg of Compound 1i. There was no increase in cognition at administration of Compound 1i at doses of 3.0 mg/kg.
Example 10
Animals were housed, treated, and a Novel Oject Recognition/Object Recognition Test was performed substantially similar to the methods and procedures described in Example 9.
One important difference, however, was that compound 1i was administered one hour after T1 in this example. The results of this test are depicted in FIG. 7 b.
As illustrated by FIG. 7 b , administration of Compound 1i, at a dose of 1.0 mg/kg, post-T1 significantly enhances cognition in treated animals. However, dosages at about 3.0 mg/kg actually reduced cognition in animals that were treated with larger doses 1 hour post-T1. Without being bound by theory, this data, along with the data in FIG. 7 a , suggests a theory wherein in certain circumstances administration of lower doses of alpha-7 nicotinic receptor antagonists disclosed herein (i.e. Compound 1i) may function to prevent desensitization of the nAChR and thereby possibly increase the efficacy of endogenous acetylcholine. Without being bound by theory, the duration of the compound administration may also possibly play an important role.
Example 11
Compounds listed in Tables 1 and 2, of Example 1, can be purchased Maybridge, Chembridge, Enamine. Details for procurement of these compounds is generally disclosed in Peng et al, โDiscovery of novel ฮฑ7 nicotinic receptor antagonistsโ Bioorganic & Medicinal Chemistry Letters 20 (2010) 4825-4830, the contents of which are disclosed herein by reference. General methods of synthesis are also disclosed in U.S. provisional application 61/501,207, the contents of which are disclosed herein by reference.
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It is an object of the present invention that the novel nicotinic receptor antagonists disclosed herein may be used in a broad array of clinical or medicinal facets. For example, it is a contemplated use of the present invention that the novel nicotinic receptor antagonists be used to inhibit the growth cycle of non-small cell lung cancer cells. Without being bound by theory, it is an object of the present invention that the nicotinic receptor antagonists disclosed herein are believed to possess reversible binding properties. Moreover, the compounds of the present invention are selective for 0.7 nAChR. For example, the compounds of the present invention are not believed to bind to 0.4 (32 nAChR neuromuscular receptors. It is also contemplated that the nicotinic receptor antagonists of the present invention will be used as a counter measure to treat exposure, or potential exposure, to a wide array of potential neurotoxins.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to automatic washers, either of the front-loading or top-loading types, and more particularly to an improved washing system and control therefor.
[0002] Automatic clothes washers generally include fluid handling systems for filling a washer tub with a wash fluid consisting of a water and detergent solution, tumbling or agitating a wash load of fabrics for a period of time, then draining the wash fluid from the tub. A portion of the washing part of the cycle may include a spray treatment or pretreatment of the fabrics while the basket is spinning. A subsequent rinse with fresh water and draining of the rinse water are also provided. All or part of the rinse cycle may include a spray rinse of the fabrics while the basket is spinning at high speed.
[0003] Spray treatment of fabrics during the wash cycle therefore is known. Spray treatment may be desirable in a clothes washer because of known benefits such as improved washing performance and reduced energy and water usage. An example of a clothes washer having spray treatment is disclosed in U.S. Pat. No. 5,271,251 for example, assigned to the assignee of the present invention. In this example, however, a probe sensor provides a signal for the purpose of maintaining a predetermined water level during recirculation. Alternatively, a pressure dome or temperature thermistor may be used to detect the water level and a determination may be made for the level of water to be used in the following swirl portion of the cycle. However, there is no determination made of the amount of fabric load contained within the washer using the on or off times of the inlet valve or valves or the information provided by the pressure sensor.
[0004] There are known disadvantages to spray treatment as well. One undesirable condition which has been found to occur during a spray pretreatment portion of the wash cycle is โsuds lockโ. When this condition occurs, contact of the fluid with the spinning basket acts to further increase the amount of suds which thus raises the height of the sudsy fluid toward the basket. The eventual result of this unstable process is that suds build up beyond the bottom of the basket and climb between the sides of the basket and tub. This large amount of suds acting between the spinning basket and the fixed tub produces a significant drag force on the basket. This drag force is large enough to cause the clutch to slip and thus causing the basket to slow down considerably. This slipping of the clutch due to excessive suds between the spinning basket and the tub is called โsuds lockโ.
[0005] Certain combinations of environmental factors have been found to increase the likelihood of suds lock. Such combinations of very small loads or no load, very large doses of detergent, liquid detergent, type of detergent and soft water have been found to increase the formation of suds during the spray pretreat cycle. Also, if the means by which the amount of water controlled during the spray pretreatment cycle is not robust, suds lock may be more likely. To guard against both worst case conditions or machine degradation over time, a control for sensing suds lock and controlling the machine based on suds lock information is desirable.
[0006] U.S. Pat. No. 4,784,666, assigned to the assignee of the present application, discloses a high performance washing process for vertical axis automatic washers which includes the recirculation of wash fluid prior to the agitate portion of the wash cycle. That patent describes, as a particular embodiment of the invention, to load a charge of detergent into the washer along with a predetermined amount of water, preferably prior to admitting a clothes load into the basket to assure that the concentrated detergent solution will initially be held in a sump area of the wash tub so that the detergent will be completely dissolved or mixed into a uniform solution before being applied to the clothes load. It is also suggested that the addition of an anti foaming agent may be desirable. No particular arrangement is provided for mixing the detergent and water to provide a uniform solution, nor is any particular means described for assuring that the amount of wash liquid within the tub during the spin wash portion of the wash cycle is an appropriate amount which is slightly in excess of the saturation level for the clothes load.
[0007] U.S. Pat. Nos. 5,219,370 and 5,233,718, assigned to the assignee of the present invention, disclose variations on a high performance washing process for vertical or horizontal axis automatic washers which include the recirculation of wash fluid prior to the agitate portion of the wash cycle or other washing or rinsing steps. The primary means for controlling water input into the systems is to detect water level using a liquid level sensor. It is suggested that a pressure dome sensor may be used to detect an oversudsing condition, however this would be performed in conjunction with usage of the liquid level sensor, which is not provided for in the present invention. These patents allow for the possibility of indirectly inferring the water level in the tumble portion of the cycle based on the sensed level of detergent liquor in the pretreatment portion, unlike the present invention which determines the amount of clothes load and possibility of suds lock.
SUMMARY OF INVENTION
[0008] The present invention provides a control for sensing the state of the washing machine during a pretreatment cycle having a combined spray and high speed spin. During such a pretreatment cycle the washer is susceptible to the possible occurrence of a suds lock condition, which may be detected and handled by the present invention. This can be accomplished by a variety of sensing techniques, through which the possible or imminent occurrence of suds lock can be determined or inferred, including sensing the condition of the wash liquid or the washing machine components. A suds lock condition may even be anticipated and avoided by the present invention. Further, by knowing that a suds lock condition is occurring or is likely to occur, the spray pretreatment portion of the wash cycle can be preterminated and the rest of the cycle can be continued. Alternatively, adding of water may be discontinued. By following a suds lock condition immediately with a deepfill of the tub of the automatic washer, suds buildup within the basket can be minimized.
[0009] By using the same technique of measuring suds lock, the size of the load can also be ascertained. This information can thus be applied to control the rest of the cycle. For example, the automatic deepfill water level and relative agitation rate can be altered according to the sensed size of the load. In the present invention, the load size is determined regardless of the types of fabric materials contained in the load. As well, in certain load conditions such as large loads, the deepfill portion may be slightly altered in order to optimize and maximize the wash performance. This may be performed not only as a result of detecting the load size but also as a result of user control inputs.
[0010] Furthermore, the control may be used to detect special conditions, for example unusually wet laundry at the outset of the wash cycle or failure in some aspect of the wash cycle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a perspective view of a partially cut away automatic washer containing recirculation hardware embodying the principles of the present invention.
[0012] [0012]FIG. 2 is a schematic diagram of an automatic washer portraying in fluid circuit form the recirculation hardware and control arrangement embodying the principles of the present invention.
[0013] [0013]FIG. 3 is a block diagram of the process for controlling the spray pretreatment portion of the wash cycle based on monitoring the condition of suds lock occurrence.
[0014] [0014]FIG. 4 a is a block diagram of an automatic washer containing recirculation hardware using flow rate information to control the amount of water added during the spray pretreatment portion of the wash cycle.
[0015] [0015]FIG. 4 b is a block diagram of an automatic washer containing recirculation hardware using height of water in the tub sump information to control the amount of water added during the spray pretreatment portion of the wash cycle.
[0016] [0016]FIG. 5 is a plot displaying the typical form by which the inlet valve is controlled based on measured information.
[0017] [0017]FIG. 6 is a block diagram of the general process for determining whether suds lock has occurred based on criteria and suds lock measure information.
[0018] [0018]FIG. 7 is a block diagram that shows the components which make up the drive system and the corresponding means for measuring the existence of suds lock through each component.
[0019] [0019]FIG. 8 is a block diagram that shows the measuring of the existence of suds lock through measuring the height of suds in the tub/basket.
[0020] [0020]FIG. 9 is a plot displaying the process by which the inlet valve is controlled based on measured information for the special case of having too much added water in the system at the start of the cycle.
[0021] [0021]FIG. 10 is a plot displaying the process by which the inlet valve is controlled based on measure information for the special case of never satisfying the measure due to some failure condition in the machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] In FIG. 1 a washing machine is generally shown at 10 which has a tub 12 with a vertical agitator 14 therein, a water supply 15 , a power supply (not shown), an electrically driven motor 16 operably connected via a transmission 20 to the agitator 14 and controls 18 including a presettable sequential control device 22 for use in selectively operating the washing machine 10 through a programmed sequence of washing, rinsing and extracting steps. A water level setting control 18 is provided for use in conjunction with control device 22 . A fully electronic control having an electronic display (not shown) may be substituted for control device 22 . The control device 22 is mounted to a panel 24 of a console 26 on the washing machine 10 . A rotatable and perforate wash basket 28 is carried within the tub 12 and has an opening 36 which is accessible through an openable top lid 30 of the washer 10 . Tub ring 37 is positioned overlying wash basket 28 and tub 12 .
[0023] The invention disclosed herein is not necessarily limited to implementation in a vertical axis washing machine as shown in the figures. Inasmuch as the invention is a washing machine having a unique control and recirculating spray wash arrangement, the invention may be equally applied in a horizontal or tilted axis washing machine. Moreover, in the specific application of the invention in a vertical axis washing machine, the invention may be practiced in a variety of machines which may include different motor and transmission arrangements, pumps, recirculation arrangements, agitators or impellers, or controls.
[0024] A sump hose 40 is fluidly connected to a sump (not shown) contained in a lower portion of tub 12 for providing a wash fluid recirculating source. Pressure dome 42 receives the recirculating fluid which exits via recirculating spray nozzle hose 48 which is fluidly connected to recirculating spray nozzle 32 . A pressure sensor or transducer 46 detects fluid pressure within pressure dome 42 and provides an output signal via lines 47 to the control, the signal varying dependent upon the sensed dynamic pressure. A second air dome 50 having a deepfill pressure sensor or transducer optionally provides a second pressure signal indicating static pressure to the control via lines 52 .
[0025] As described herein, a pressure sensor may be a pressure switch having predetermined pressure levels that, within certain limits, will provide one or more signals to control 22 that a certain pressure has been achieved. Depending on the presence or absence of such signals, the control will receive and store or process such information, as is well known. Alternatively, a transducer may be used to sense pressure and provide a signal of varying frequency or voltage to control 22 indicating the pressure levels detected.
[0026] In FIG. 2 a schematic diagram further describes an example of a washing machine incorporating the present invention. Hot water inlet 11 and cold water inlet 13 are controlled by hot water valve 17 and cold water valve 19 , respectively. Valves 17 and 19 are selectably openable to provide fresh water to feed line 60 . A spray nozzle valve 21 is fluidly connected to feed line 60 for selectably providing fresh water to tub 12 when desired. This fresh water is delivered by fresh water spray nozzle 31 via fresh water hose 33 . Valves 17 and 19 are openable individually or together to provide a mix of hot and cold water to a selected temperature.
[0027] Upon opening one or both of valves 17 and 19 , fresh water is selectably provided to a series of dispenser valves via feed line 60 . Valve 62 selectably provides fresh water to detergent dispenser 63 , valve 64 selectably provides fresh water to bleach dispenser 65 , and valve 66 selectably provides fresh water to softening agent dispenser 67 .
[0028] As further shown in FIG. 2, the washing machine includes a wash liquid recirculation system. In order to recirculate wash liquid for the recirculating spray wash, tub sump 41 collects wash liquid and is fluidly connected to pump 23 by sump hose 40 . Pump 23 is selectably operational to pump liquid from tub sump 41 via pump outlet hose 25 either to recirculating hose 27 or drain hose 29 depending on the position of bidirectional valve 30 . Recirculating hose 27 provides recirculating wash liquid to pressure dome 42 , the wash liquid exiting the pressure dome 42 via recirculating spray nozzle hose 48 and being emitted to the wash basket 28 via recirculating spray nozzle 32 .
[0029] Pressure dome 42 provides a head of pressure varying dependent upon the amount of wash liquid contained in the recirculating wash system by maintaining a captured dome of air in communication with the recirculating wash liquid. The pressure dome 42 provides a channel for the captured air to keep in contact with pressure sensor 46 via pressure line 45 .
[0030] Pressure sensor 46 provides optionally either an on/off or a varying or dynamic signal to control 22 via lines 47 , the signal varying dependent on the sensed pressure of the recirculating wash liquid. Control 22 also optionally receives a static pressure signal from deepfill transducer dome 50 via lines 52 for signaling the level of wash liquid within wash tub 12 , however the invention disclosed herein may be practiced without use of a deepfill pressure dome. Control 22 is further operable to receive input signals via lines 49 , including signals from valves 21 , 62 , 64 and 66 providing on and off times for these valves.
[0031] By sensing the air pressure within pressure dome 42 , the amount of recirculating wash liquid in the washing machine may be inferred. This information is useful to determine the amount of free water in the washing machine during a recirculating wash. Thereby, the amount of clothing in the washing machine may be inferred, which information is useful in order to minimize water and energy usage during a spray pretreatment cycle, stain cycle or other recirculating wash cycle, and further during later or other portions of the cycle. Also, the suds lock condition, or absence thereof during portions of a cycle may be determined. Suds lock may be prevented by limiting recirculating wash liquid to slightly in excess of clothes saturation.
[0032] A basic process for the new control scheme of the spray pretreatment portion of the wash cycle is shown in the block diagram 100 in FIG. 3. The process begins at the commencement of spray treatment 102 by starting monitoring of the suds lock algorithm 104 . The process simply either completes the full cycle if suds lock does not occur or skips through the rest of the pretreatment cycle and onto the next step 106 in the case that suds lock should occur. This process 100 is independent of the method by which the existence of suds lock is determined.
[0033] Several methods can be applied in order to ascertain the existence of suds lock. FIG. 4 a displays a block diagram 108 of the automatic washer containing recirculation hardware where a measure based on the flow rate of the wash liquid recirculation line is used to ascertain when water is added to the recirculation system. The flow rate can be measured in one of a number of known ways. A flow washer 68 contained in detergent dispenser valve 63 controls the flow rate within a predetermined range for a variety of predictable inlet water pressures. Limiting flow in this manner allows the flow rate to be inferred based upon the on time of the inlet valve. A flow meter may also be used. Finally, the deep fill rate may also be discerned.
[0034] This intermittent process is due to the dry clothes load absorbing water into the load and thus the system requiring more water to regain the necessary flow rate. A similar approach shown in a block diagram 110 in FIG. 4 b to determine when water needs to be added to the system can be performed by any of various techniques capable of measuring the height of the wash fluid in the sump portion of the tub. Alternatively, a pressure sensor may be used to determine whether one or more predetermined pressure levels have been reached. In either case, if the control determines that the necessary wash fluid amount recirculating within the washer is satisfied, the control discontinues adding water by intermittent opening of the water inlet valve.
Detecting Load Size During Pretreatment Portion of Cycle
[0035] Using either of these means shown in FIGS. 4 a or 4 b to control the process of adding water to the system, an alternating pattern of the times for the addition of water to the system and not adding water to the system can be gained. FIG. 5 shows such a typical pattern or profile 112 relating to the on and off periods of the inlet valve for the spray pretreatment portion of the automatic wash cycle, based on whether the water level or water pressure detecting means is satisfied. Preferably, the control determines the necessary amount of wash liquid as that amount which is slightly in excess of the saturation level for the clothes load.
[0036] Accordingly, as the pretreatment portion of the cycle proceeds as shown in FIG. 5, the control continually monitors the inlet on or off times or both on and off times, or the pressure or water level signals which are used to control the inlet on, off or on and off times. This information, as discussed later herein, may be used to determine whether the clothes washer is experiencing a suds lock condition or some other abnormal condition if the information is outside a certain expected range. As well, however, this information may be used to determine the load size being washed, so that the pretreatment cycle and later portions of the wash cycle may be altered and preferably optimized or adapted to effectively complete the cleaning and rinsing of the clothes, but no more in order to avoid suds lock.
Pretreatment Cycle Control Based on Load Size Measurement
[0037] By using the measure of load size during the pretreatment cycle, the rest of the pretreatment cycle can be optimized based on the load size information. After the desired water level or pressure is detected as initially satisfied by the control 22 , the washing machine is allowed to continue the normal pretreatment cycle where water is added to the system as requested by the control system for a first predetermined time. The control then identifies the load size in a manner as previously discussed. The inlet valve may be shut off regardless of whether water is called for by the control system when a second predetermined time is reached. This second predetermined time may be defined based on the load size measure. At this time, the pretreatment step is completed and the machine proceeds through the rest of the cycle. The process of not adding water will aid the system in avoiding suds lock which increases the performance of the cycle.
[0038] In another example of optimizing the rest of the pretreatment cycle based on the load size information, the control system determines the total water fill times at preselected intervals. Depending on the total water fill time, a preselected overall cycle time for pretreatment is performed, during which water may be added. The cycle is further optimized by taking into consideration the water level and cycle selected by the user, so that the washer may perform not only according to the load size detected but in accordance with the demands of the user.
Total Cycle Control based on Load Size Measurement
[0039] From the various means of determining load size during the pretreatment portion of the cycle, this information can be applied to control other portions of the cycle. In previous washers, the load size or water level input on the console is the input used to control the amount of water added to the system in the deep fill and the relative agitation rate based on the type of cycle chosen. In the present invention, the load size determined from the pretreatment step can be applied in a similar way to determine water amounts and control the agitation performed during the rest of the wash cycle. For example, the load size information can be used to determine the agitation length and rate, to determine the deep fill wash length, spin time and speed, the deep fill or spray rinse length, spin time and speed, or the number of rinses.
[0040] An automatic washer incorporating the present invention may preferably include traditional user control inputs such as cycle, water temperature and water level. Although the input by the consumer may be taken into consideration to affect the cleaning cycle, the control selectively processes the previously mentioned inlet on, off or on and off, water level or pressure information independently of such user input to determine the size of the clothes load. It is noted that the type of clothes, particularly the variety of materials providing the makeup of the clothes is not of critical importance once the pretreatment cycle is completed, since the load size information gained during the pretreatment cycle is all that is needed to continue the wash process. However, the user input may be considered as part of an algorithm such that the performance of the washer, for example the length of wash time, is not greatly different than consumer expectations for a selected input.
[0041] In another example of optimizing the rest of the wash cycle based on detected load size, it is a known problem in a vertical axis washer to turn over a large clothes load approaching 17 pounds during a deep fill wash. One difficulty is that after filling the washer to the maximum level and beginning agitation, the large items in the load such as sheets, tablecloths or towels may be displaced above the waterline by the agitator, which physically lowers the water level in the tub. The lowering of the water level in the tub can be anticipated by control 22 or detected via a pressure sensor 46 or 50 and compensated for by adding water to return to the maximum level.
[0042] Alternatively, to address the aforementioned problem, a delayed fill may be used. When the user selects a heavy duty cycle along with maximum water level, for example the water level in the deep fill wash is initially brought to a level slightly below the maximum. The clothes load will be partially submerged, with a portion of the load remaining dry or at most partially saturated on the surface. At this water level, the agitator is allowed to commence turning and will easily pull the dry clothing from the top of the load, moving the clothes down the center of the basket and up the outside in the normal motion. After an initial preselected period, long enough to allow the load to be fully wetted and largely submerged, the washing machine may be filled to the maximum level followed by additional agitation or while continuing to agitate. The preceding process assures that normal rollover of the wash load is achieved as quickly as possible despite the large load.
Suds Lock Measuring
[0043] [0043]FIG. 6 displays a block diagram 118 of the general process for determining whether suds lock has occurred based on selected criteria and suds lock measure information. This diagram is independent of chosen measurement technique. Several sets of criteria are satisfactory for the case of using information about the inlet water valve cycling information measurement of suds lock. The following table contains several functional criteria:
[0044] Table: Suds Lock Criteria Table for Inlet Water Valve Based Measures.
TABLE Suds Lock Criteria Table for Inlet Water Valve Based Measures. Suds Lock Measure Suds Lock Criteria Case (1) t on (0) 10-20 sec. Case (2) t on (0)/(t on (1)) N Case (3) t on (0)/(t on (1) + t on (2)) N Case (4) t on (0)/(t on (1) + t on (2) + t on (3)) N
[0045] As part of the suds lock criteria, note that if t on (2), t on (3)=0, then let t on (2)=t on (3)=t on (1). The optimum value for N is approximately 2. The algorithm also incorporates a minimum time, t min โ check , which to start checking for suds lock to occur. This time could be set between 0 sec and 40 sec. In addition to satisfying the suds lock criteria, there also is a time t on โ min which sets a minimum time of addition which it must be above to be considered as suds lock condition. Typical ranges for this are between 2 to 4 sec.
[0046] Other ways exist for detecting suds lock in the washing machine. FIG. 7 displays a block diagram 120 that shows the components which make up the drive system and the corresponding means for detecting the existence of suds lock through each component. For the basket, the means for detecting the existence of suds lock 122 may be summarized as follows.
[0047] A first suds lock detection method is by measurement of the basket RPM (by magnetic, optical or ultrasonic means) after the basket is brought up to normal operating speed. When basket reduces RPM by 70% from the steady state value, suds lock has occurred.
[0048] A second suds lock detection method is by measurement of the basket or tub acceleration after the basket is brought up to normal operating speed. Vibration of the basket or tub should be fairly constant or increasing during the spray pretreatment portion of the cycle unless suds lock occurs.
[0049] For the drive system, the means for detecting the existence of suds lock 124 may be summarized as follows.
[0050] A first suds lock detection method is by measuring the temperature of the clutch. When a suds lock condition occurs, the temperature of the clutch will increase significantly during suds lock condition. A second suds lock detection method is by measuring torque on drive components. When a suds lock condition occurs, a significant drop in torque will occur.
[0051] For the motor, motor control and supply power, the means for detecting the existence of suds lock 126 , 128 and 129 may be summarized as follows. A first suds lock detection method is by measurement of motor RPM using a tachometer which is built into the motor. When the basket reduces RPM by 70% from steady state value, suds lock has occurred. A second suds lock detection method is by measurement of the current or wattage going to the motor measured at motor. When current or wattage increase by a given percentage, suds lock has occurred.
[0052] A third suds lock detection method is by measurement of total current or wattage going to the entire machine, since motor current is by far most significant component. When current or wattage increase by a given percentage, suds lock has occurred. A fourth suds lock detection method is by measurement using an opto coupler for obtaining information about drop in the torque draw of the motor. A fifth suds lock detection method is by measurement using a ferrite core sensor for obtaining information about the drop in the torque draw of the motor. In the latter two methods, when torque drops by a given amount, suds lock has occurred.
[0053] In addition to measurements which can be made on the drive system, measurement of the height of the suds in the system can be made. FIG. 8 displays a block diagram 130 illustrating the components which are to be observed, that is the tub or the basket, and the means for detecting the existence of suds lock through each component. Specific embodiments of such techniques to measure the height of the suds during a spray pretreatment portion of the wash cycle may include a) providing a conductivity strip along the side of the basket; b) ultrasonic measurement, or c) optical measurement. Feedback provided to the control in each case indicates an oversuds condition, from which it may be inferred that suds lock has occurred.
Special Conditions
[0054] In addition to the occurrence of suds lock, there are a few special conditions which can as be detected by the control. Although other detection means may be used, in these examples the control monitors the inlet valve on time over a prescribed check time. One such condition occurs when the machine is started in pretreatment portion of the cycle with much more water than necessary. FIG. 9 displays the process by which the inlet valve is controlled based on measure information for the special case of having too much added water in the system at the start of the cycle. This condition can occur for the reasons that the user starts the machine into normal deepfill (without prefill), then stops the machine after a good amount of water has filled the machine (over 2 gallons) and the machine is switched and restarted in pretreatment cycle; the user puts a very soggy clothes load into the machine or the user physically adds water into the machine with the load.
[0055] For all these conditions, the time by which the machine calls for water will be very small. Thus by monitoring the time by which the control system calls for water with respect to some length of checking time, this condition can be ascertained. If such a case should occur, the pretreatment cycle may be ended and the rest of the cycle is continued.
[0056] Another special condition can be detected by the primary means of monitoring the inlet valve on time over a prescribed check time. One such condition may occur when the washing machine is in the recirculating spray pretreatment portion of the cycle and the machine continuously calls for water without stopping.
[0057] [0057]FIG. 10 displays a graphic depiction 140 of the process by which the inlet valve is controlled based on measured information in the special case where the recirculation flow in the system at the start of the cycle is not satisfied for some finite period of time. In addition to sensing this condition based on the recirculation flow being not satisfied, additional information can be gained from the deepfill pressure transducer for the air dome 50 in the tub.
[0058] For the case where the deepfill pressure transducer does not sense the existence of a sizable amount of water in the tub, a variety of machine conditions may be a cause. Under the category of washing machine component failures, the failures can include a sizable leak in the tub or the recirculation or drain hose system; one or more bad inlet valves not adding water to system, or a recirculation diverter valve failed or stuck in the drain direction. Under the category of non-washing machine component failures might be a long fill due to very low line pressure.
[0059] For the case where the deepfill pressure transducer is sensing the existence of a sizable amount of water in the tub, the following machine conditions may be a cause, all of which are washing machine component failures. The failures can include a bad recirculation pressure switch, a pump or motor failure, a severe recirculation line clog or the recirculation pressure hose is disconnected.
[0060] In case of such failure, the control 22 will end the cycle and indicate the failure condition to the consumer.
[0061] As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of the contribution to the art.
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This invention relates a control for an automatic washer incorporating a spray pretreatment or stain care cycle. In order to manage the occurrence of the condition of suds lock, the state of the washing machine related to the suds lock condition during spray pretreatment is determined by one or more of a number of methods. With this information concerning the state of the spray pretreatment process, the occurrence of suds lock can be ascertained and the cycle can be controlled accordingly to minimize negative effects resulting from a prolonged suds lock condition. Additionally, with certain information related to the occurrence of suds lock, steps can be taken during the spray pretreatment portion of the cycle to avoid the condition of suds lock altogether. Using the same primary process for measuring suds lock, load size can also be ascertained. Information about load size can be used to control the wash cycle.
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FIELD OF THE INVENTION
[0001] The present invention relates to heparan sulfate proteoglycans, particularly to syndecans, and to their several uses in promotion of tissue-specific cell proliferation, migration and differentiation.
[0002] ABBREVIATIONS: FGF, fibroblast growth factor, FGF2, basic FGF; FGF1, acidic FGF; FGFR, FGF receptor; HS, heparan sulfate; HSPG, heparan sulfate proteoglycan; EDHS, endothelial cells derived HSPG; AP, alkaline phosphatase; CHO, chinese hamster ovary; DMEM, Dulbecco's modified Eagle medium; FCS, fetal calf serum; GST, glutathione S-transferase; MBS, m-maleimidobenzoyl-N-hydroxysuccinimide ester; SDS, sodium-dodecyl-sulfate; PAGE, polyacrylamide gel electrophoresis; PMSF, phenylmethylsulfonyl fluoride; KLH, keyhole limpet hemocyanin.
BACKGROUND OF THE INVENTION
[0003] Fibroblast growth factors (FGFs) constitute a family of at least eighteen polypeptides which are mitogenic for cells of mesenchymal and neuroectodermal origin (1). FGFs share 30-60% amino-acid sequence homology and a high affinity for heparin and heparan-sulfates (HS). A crucial role for cell surface HS in growth factors activity was revealed by the finding that high affinity receptor binding of basic FGF (FGF2) is abrogated in chinese hamster ovary cell lines defective in their metabolism of glycosaminoglycans (2) and in sulfate depleted myoblasts (3). Receptor binding and biological activity of FGF2 could be fully restored upon the addition of exogenous heparin. Further studies have established the involvement of heparin and HS in the binding and signal transduction of FGF1, FGF2 and FGF4 both in vitro and in vivo (4-9). Direct interaction of heparin with a specific sequence in the extracellular domain of FGF receptor (FGFR) was also demonstrated and shown to be required for FGFR interaction (10). These findings strongly support the idea that a ternary functional complex containing FGF, FGFR and a heparin like molecule is required for the activation of signal transduction pathways linked to the FGF-FGFR complex.
[0004] The basic heparan sulfate proteoglycan (HSPG) structure consists of a protein core to which several linear heparan sulfate chains are covalently attached (11). A few HSPGs were purified to homogeneity, including the large extra-cellular matrix HSPG perlecan (12), the membrane associated glypicans (13) and the integral membrane HSPGs, syndecan, fibroglycan (14), N-syndecan (15) and amphyglycan/ryudocan (13, 16). The last four comprise a family of membrane integral HSPGs and were re-named Syndecan 1-4 (in the above same order) (17). The syndecans share a similar structure that includes a short highly conserved intracellular carboxy-terminal region, a single membrane-spanning domain and an extracellular domain with three to five possible attachment sites for glycosaminoglycans (17). The intracellular conserved region of syndecan-4 was recently shown to interact with Protein kinase C and with phosphatidylinositol 4,5-biphosphate, both of which can direct and regulate the recruitment of syndecan-4 to the cells focal contacts (18-20).
[0005] A preliminary survey of several defined and affinity purified species of cell surface HSPGs, isolated from fetal lung fibroblasts, including syndecan-1, syndecan-2, and glypican failed to promote high affinity receptor binding of FGF2 (21). A similar lack of activity was observed with various species of HS isolated from bovine arterial tissue that were characterized for their effect on vascular smooth muscle cell proliferation. Most of these species of HS and HSPGs in fact inhibited, in a dose-dependent manner, the activation of FGF2-receptor binding induced by heparin (21, 22). In contrast, perlecan, the large basement membrane HSPG (12) isolated from human fetal lung fibroblasts, was found to induce high affinity binding of FGF2 to FGFR1 as well as to promote FGF dependent angiogenesis in vivo (23). More recently syndecan-2 isolated from macrophages was found to enhance receptor and biological activity of FGF2 (24).
SUMMARY OF THE INVENTION
[0006] Thus, according to the present invention, binding of fibroblast growth factors (FGFs) to their high affinity receptors is potentiated by heparin or heparan sulfate (HS). As described herein, syndecans, integral membrane heparan sulfate proteoglycans (HSPG), either purified from endothelial cells or when ectopically overexpressed, promote high affinity binding of a FGF to a FGF receptor, particularly of FGF2 and FGF1 to FGF receptor 1. When expressed in mutant cells, deficient in total HS or which specifically lack 2-O-sulfated iduronic acids, syndecans do not support receptor binding of FGF1 or 2. Syndecan-4 was also found to form SDS-resistant dimers, similar to those observed for syndecans-1 and 3, the formation of which we find to be partially dependent on its HS chains.
[0007] Genetically engineered, chimeric soluble syndecan-1, -2, -3 and -4 ectodomains fused to human gamma globulin Fc, expressed in 293T cells, were found according to the invention to be post-translationally modified to carry predominantly HS chains which support receptor binding and biological activity of FGF1 and FGF2. Taken together, these results indicate that syndecans can serve as an integral membrane modulator of FGF signaling.
[0008] The present invention thus relates to a molecule capable of promoting high affinity binding of a fibroblast growth factor (FGF) to a FGF receptor (FGFR), said molecule being selected from:
[0009] (i) a recombinant chimeric fusion molecule comprising the extracellular domain of a syndecan or a fragment thereof fused to a tag suitable for proteoglycan purification, said fusion molecule being post-translationally glycosylated to carry at least one chain of a beparan sulfate having at least one highly sulfated domain;
[0010] (ii) a DNA sequence encoding a chimeric fusion molecule comprising the extracellular domain of a syndecan or a fragment thereof fused to a tag suitable for proteoglycan purification; and
[0011] (iii) a sugar molecule from a syndecan carrying at least one chain of a heparan sulfate having at least one highly sulfated domain.
[0012] The molecule according to the invention may promote high affinity binding of FGF1 and FGF2 to FGFR1, or of FGF9 to FGFR2 and to FGFR3, or of any other FGF to its respective receptor(s).
[0013] The extracellular domain according to (i) and (ii) above may be an extracellular domain of any of the syndecans -1, -2, -3 or -4, or a fragment thereof, wherein said extracellular domain or fragment preferably comprises the glycosylation sites of the syndecan molecule. In the case of syndecan-4, the extracellular domain comprises the amino acids 1-145 of syndecan-4, and a fragment thereof comprises at least 75 amino acids of the extracellular domain of syndecan-4.
[0014] According to the invention, the syndecan extracellular domain may be fused to any tag suitable for proteoglycan purification including, but not being limited to, glutathione S-transferase (GST) or polyHis, and preferably the Fc region of the human gamma globulin heavy chain.
[0015] The post-translational glycosylation occurs when a DNA molecule according to (ii) above is expressed in suitable mammalian cells including, but not being limited to, endothelial, fibroblast, and epithelial cells, such as embryonic kidney cells, ovary cells, e.g. chinese hamster ovary cells (CHO), or aortic endothelial cells. The type of syndecan and/or the type of cells in which the fused molecule is expressed will determine the tissue specificity of the fused molecule.
[0016] The glycosaminoglycan chains of syndecans according to (iii) above may be prepared by protease treatment of the syndecan, for example as described in Nader et al., 1987 (27). The heparan sulfate that constitutes the glycosyl chain of the syndecan has, preferably, at least one highly O-sulfated domain of at least 10 sugar units, and is preferably 2-O-sulfated.
[0017] Syndecan coding sequences may be obtained by cDNA cloning or by reverse transcriptase PCR cloning by standard methods well known in the art. The desired extracellular domain or fragments thereof can then be excised by restriction enzyme digest or by PCR using appropriate oligonucleotide primers. The so obtained sequences may then be fused to a suitable tag to form the DNA sequences of (ii) above, preferably with the Fc of the immunoglobulin heavy chain, most preferably human IgG1. When expressed as a fusion protein, the ectodomain of the syndecan will usually be cleaved from the fusion partner. This expression may occur in vivo after administration of a DNA sequence of (ii) above, thus making the soluble biologically active extracellular domain of the syndecan available to exert the desired biological activity.
[0018] In particular embodiments of the invention, the recombinant chimeric fusion molecule comprises the extracellular domain of syndecan- 1, -2, -3, or -4 fused to the recombinant Fc region of the human gamma globulin heavy chain, carrying at least one chain of a heparan sulfate having at least one highly sulfated domain (Syn1-Fc, Syn2-Fc, Syn3-Fc, Syn4-Fc). In the case of Syn4-Fc, the chimeric molecule may carry 1, 2 or the 3 polysaccharide chains of Syn4.
[0019] The chimeric fusion molecule of (i) above, the DNA molecule of (ii) above and the syndecan derived sugar molecule of (iii) above are capable of modulating (both enhancing and inhibiting) heparin-dependent growth factor activity relevant for promoting tissue-specific cell proliferation, migration and differentiation. The growth factor which activity can be modulated by said molecule includes, but is not limited to, a FGF, a vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), an epidermal growth factor (EGF) and keratinocyte growth factor (KGF).
[0020] The present invention thus further relates to pharmaceutical compositions comprising a molecule (i), (ii) or (iii) of the invention and a pharmaceutically acceptable carrier. This composition can be used for induction of angiogenesis, bone fracture healing, enhancement of wound healing, promotion of tissue regeneration and treatment of ischemic heart diseases and of peripheral vascular diseases, for example for promoting liver regeneration, or for promoting tissue regeneration alter transplantation of myocytes into heart tissues, or after transplantation of cells into brain tissue.
[0021] The molecules of the invention can further be used in combination with one or more growth factors such as a FGF, e.g. FGF2, a VEGF, an EGF, HGF and/or KGF. The growth factor may be administered before, together with, or after the molecule of the invention. For example, a molecule of the invention may be administered together with: (a) FGF2 for treatment of heart failure by transplantation of myocytes, or for promotion of tissue regeneration after transplantation of dopaminergic/neuronal cells for example in Parkinson disease; (b) FGF2 and/or VEGF for induction of angiogenesis or for treatment of ischemic heart disease or peripheral vascular disease; (c) HGF for promoting liver regeneration; (d) KGF for enhancement of wound healing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 shows that binding of FGF2 and FGF1 is modulated by purified endothelial derived syndecan-4. Soluble extracellular domain of FR1-AP fusion protein was immunoprecipitated with anti-alkaline phosphatase antibodies and incubated with 125 I-FGF1 (right panel) or 125 I-FGF2 (left panel), in the absence or presence of 1 ฮผg/ml heparin, endothelial derived syndecan-4 (EDHS), or the isolated syndecan-4 HS chains. Binding was performed as described under โExperimental Proceduresโ. Bound complexes were extensively washed with low affinity buffer to remove FGFs bound to the HS. The associated radiolabeled FGFs were determined by a gamma-counter. These results represent one out of three independent experiments, carried out in duplicates. Standard error bars are indicated.
[0023] FIGS. 2 A- 2 B show overexpression of syndecan-4 in CHO-KI cells. FIG. 2A: Confluent cultures of wild type CHO-KI cells transfected with syndecan-4 cDNA were incubated with specific monoclonal antibodies directed to the extracellular domain of syndecan-4, and detected by radiolabeled anti-mouse antibodies (filled bars). Cells were lysed and counted in a gamma-counter. CHO-KI cells of the identified syndecan-4 positive clones were metabolically labeled with 35 S-sulfuric acid for 24 hours and the amount of heparan sulfate associated radioactivity was measured by liquid scintillation (dashed bars) as described under โExperimental Proceduresโ. Each point represents the mean of duplicate determinations. P-parental untransfected cells; E1, E4, E5 & E10-. The isolated positive CHO-KI clones transfected with syndecan-4 cDNA. FIG. 2B: Positive clones of wild type CHO-KI and GAG deficient mutant CHO-745 were extracted as described under โExperimental Proceduresโ and treated with heparinase-I and -II mixture. Syndecan-4 protein bands were examined by running equal amounts of cell extracts on SDS-PAGE and transferring to a nitrocellulose membrane. Detection was done with P710 anti-syndecan-4 polyclonal antibodies.
[0024] FIGS. 3 A- 3 B show binding of FGF2 to FGFR1 on immobilized syndecan-4. Cells of the indicated clones were extracted as described under โExperimental Proceduresโ. Equal amounts of cell extracts were immunoprecipitated with anti-P710 antibodies and incubated with FGF2 (50 ng). FIG. 3A: Proteins were separated on reducing SDS-PAGE containing ฮฒ-mercaptoethanol, and transferred to a nitrocellulose membrane. FGF2 was detected with the FB-8 monoclonal antibody. Minor amounts of FGF2 were non-specifically bound to the beads (right lane). D-dimers; M-monomers. FIG. 3B: Similar samples were further incubated with FR1-AP and the amount of the bound receptor was estimated by the associated alkaline phosphatase enzymatic activity as described under โExperimental Proceduresโ. Each data point is the mean of duplicate determinations after subtraction of non-specific binding.
[0025] FIGS. 4 A- 4 C show expression and metabolic labeling of a soluble secreted Syn4-Fc fusion protein. FIG. 4A: The extracellular domain of syndecan 4 cDNA (black) was subcloned into the CDM7 vector in frame with the Fc portion of human gamma globulin (doted). The BamHI and HindIII sites used for cloning are indicated. FIG. 4B: CDM7-Syn4-Fc plasmid was co-transfected with the pcDNA3 neomycin resistant vector into 293T cells, and positive clones were selected by dot-blot analysis. Conditioned medium collected from these cells was treated with a mixture of Heparinase-I and -III and analyzed by 10% SDS-PAGE. The proteins were transferred to nitrocellulose membrane and detected with horseradish peroxidase conjugated to Protein A. FIG. 4C: Positive 293T clones expressing the Syn4-Fc fusion protein were metabolically labeled with 35 S-sulfuric acid and 3 H-leucine for 24 hours The conditioned medium was collected and concentrated on Protein-A Sepharose. Equal amounts of radiolabeled syndecan-4 from each of the different clones (Table 1) was separated on a 3-15% gradient SDS-PAGE without or with pre-treatment with heparinase-I and -III (Hepa's). The gel was dried and exposed to X-ray Kodak film for 3 days.
[0026] FIGS. 5 A- 5 C show that syn4-Fc promotes the binding and mitogenic response to FGF2 and FGF1. FIG. 5A: High affinity binding of FGF2 and FGF1 to FGFR1. Conditioned media (100 ฮผl) from 293T cells expressing Syn4-Fc or Erb4-Fc, was immobilized on Protein A Sepharose and incubated in the absence or presence of 75 ng of either FGF1 or FGF2. The coupled beads were washed with HNTG, further incubated with FR1-AP for 2 hours and extensively washed. The bound receptor level was determined by the associated AP activity. FIG. 5B: The ability of conditioned media (100 ฮผl) from 293T cells expressing Syn4-Fc either untreated or treated with heparinase-I and -III (Hepa's), to promote binding of FGF2 to FR1-AP, is indicated. FIG. 5C: Syn4-Fc promotes FGF1 dependent mitogenic response of FGFR1 expressing cells. Thymidine incorporation into heparan sulfate deficient (745) CHO cells overexpressing FGFR1. Cells were serum starved for 24 hours and incubated with or without 5 ng/ml FGF1, in the absence or presence of heparin (Hep) or purified Syn4-Fc (Syn4) at the indicated concentrations (ฮผg/ml) for 14 hours. 3 H-thymidine (0.5 ฮผCi/ml) was added for 2 hours, and washed. Cells were fixed, washed and dissolved in 0.1 M NaOH. DNA associated radioactivity was measured by liquid scintillation counting. Each data point represents the mean of duplicate determinations. The variations in the duplicates' results did not exceed 10% of the mean value.
[0027] [0027]FIG. 6 shows syndecan- 1, -2 and -4 Fc specific induction of FGF-FGFR binding. Conditioned media of growth plate derived chicken chondrocytes cells (LSV) expressing the chimeric Syndecans 1, 2, 3 or 4 fused to the human IgG-Fc fragment were incubated with protein A-agarose beads. The beads were then washed with 2M NaCl and incubated with FGF1, FGF2 or FGF9, following by incubation with soluble FGF receptors (FGFR) 1, 2 and 3, fused to human placental alkaline phosphatase. Significant differences in the binding specificity of the different FGF-FGFR complexes exist. Syn-4-Fc promotes the interaction of FGF2 with FGFR1 and FGFR2 but not with FGFR3. Syn-2-Fc promotes the interaction of all tested ligands with FGFR3 but not all other tested interactions. Surprinsingly, Syn-1-Fc a high affinity interaction of FGF2 with FGFR3, which was not observed with the other syndecans or with cells expressing FGFR3.
[0028] FIGS. 7 A- 7 B show the effects of 2-O-sulfation on syndecan-4 activity. FIG. 7A: Positive 293T or Pgs-F17 clones expressing the Syn4-Fc fusion protein were metabolically labeled with 35S-sulfuric acid for 24 hours. The conditioned medium was collected and concentrated on Protein A-Sepharose. Equal amounts of radiolabeled syndecan-4 from each of the different clones (Table 1) were separated on a 3-15% gradient SDS-PAGE. The gel was dried and exposed to X-ray Kodak film for 3 days. FIG. 7B: Conditioned media (100ฮผl) from the above clones was adsorbed to Protein-A Sepharose incubated without or with 75 ng of FGF1 or FGF2, as indicated. The coupled beads were washed with HNTG, further incubated with FR1-AP for 2 hours and extensively washed. The bound receptor level was determined by the AP activity. Each data point is the mean of duplicate determinations.
[0029] [0029]FIG. 8A depicts the nucleotide and amino acid sequences of syndecan-4. The nucleotide sequence of mouse EDHS (syndecan-4 homologue) and its deduced amino acid sequence in one letter code are shown. The single putative transmembrane domain is underlined. The potential glucosaminoglycans attachment sites are indicated by diamonds (โ). The doted underline indicates the sequence of the peptide P710 used as antigen for antibody preparation. FIG. 8B: Amino acids sequences of mouse syndecan-1 (49), rat syndecan-2 (50), mouse syndecan-3 (14) and mouse syndecan-4 were compared using the GCG pileup program. Black background indicates at least three identical amino acids, and gray background indicates at least three similar amino acids. FIG. 8C: Amino acids sequences of syndecan-14 from mouse (EDHS, FIG. 8A), rat (ryudocan), human (amphiglycan) and chicken were compared using the GCG pileup program. Black background indicates at least three identical amino acids, and gray background indicates at least three similar amino acids.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The involvement of sulfated glycosaminoglycans in high affinity interactions and signaling of FGFs and other heparin binding growth factors is now well documented (2-5, 7-9, 38). A major outstanding question is the identity of the HSPGs that may carry the oligosaccharide domain, which serves to modulate FGF-receptor interactions in vivo.
[0031] In the present application, we describe the expression of the mouse homologue of syndecan-4 and its identification as a candidate cell surface modulator of FGF2 and FGF1 receptor binding and activation. Syndecan-4 expressed either as an integral transmembrane proteoglycan or in a soluble secreted form efficiently enhanced high affinity binding of both FGF1 and FGF2. This effect of syndecan-4 was not restricted to FGFR1 but was shown to occur also with FGFR2. These results indicate that syndecan-4 plays an important role in regulating FGF-FGFR binding and signaling in vivo.
[0032] Perlecan, the large basement membrane HSPG was previously found to induce high affinity binding and biological activity of FGF2 (23). More recently glypican isolated from rat embryonal myoblasts (39) and syndecan-1 expressed in Raji lymphoma cells (40) were shown to mediate FGF binding and activity. This may imply some functional redundancy with regard to activation of FGFs by multiple, nevertheless discrete, types of HSPGs from the cell surface and the extracellular matrix. Alternatively, there may be a specific effect for each proteoglycan that is at least partially determined by the localization of the proteoglycan in either the extracellular matrix or at the cell surface. Another possibility is that these proteoglycans may act in synergism to enhance specific activation by FGFs. In retinal pigmented epithelial cells, for example, changes in the expression of both plasma membrane proteoglycans and perlecan are correlated with FGF2 mitogenic activity (41). This co-amplification may serve as an example of a coordinated action of cell surface and extracellular matrix activating proteoglycans that act in concert to enhance FGF signaling.
[0033] The presence of an activating HSPG on the cell surface may be of special importance for the autocrine activity of FGF. Such an autocrine activity has been proposed to regulate endothelial cell proliferation and to drive autocrine growth in several melanoma cell lines that produce FGF2 and are dependent on endogenous FGF2, in contrast to normal melanocytes (42). Transformation of NIH-3T3 cells by signal peptide containing FGFs has also been suggested to result from an internal autocrine signaling loop (43, 44). A basic characteristic of this autocrine activity is that all components of the signaling complex including the appropriate HSPG should be expressed within the same cell. Syndecan-4 expression is highly abundant in vivo and is found on a variety of cell lines including endothelial, neural, fibroblastic and epithelial cells (45) where it can serve as an integral part of such an FGF autocrine complex.
[0034] The effect of syndecan-4 is solely dependent on its HS chains, therefore, eliminating these chains either by heparinase treatment or by expressing the core protein in the Pgs-A745 CHO mutant cell line, completely abolished its effect. The nature and defined structure of the glycosaminoglycan chains could, in principle, be determined by the nature of the core protein carrying these chains or alternatively by the type and differentiation stage of the cells expressing these core proteins. We show here that expression of syndecan-4 (or its ectodomain) in different cell types including endothelial, fibroblast or epithelial cells results in a recombinant proteoglycan that can bind FGF2 and share a similar capability to promote a high affinity interaction with FGFR1. These findings suggest that at least as far as the HS structure is concerned syndecan-4 can promote FGF2 interaction with its receptor in all the cell systems tested so far. A more quantitative analysis, will assess possible cell type differential effects of syndecan-4 on ligand-receptor specificity.
[0035] The structural characteristics of heparin required to promote high affinity binding of FGF2 are specific and restricted to highly O-sulfated oligosaccharides of at least 10 sugar units in length (21, 34, 35). Heparin and HS fragments with high affinity for FGF2 and FGF1 were isolated and found to be polymers rich in 2-O-sulpho-ฮฑ-L-iduronic acid (46, 47). These specific domains of high charge density, while widely distributed in heparin, are rare in HS, where they may be involved in FGF binding and activation. The HS structure determined for syndecan-4 associated HS chains, isolated from endothelial cells, is composed of four highly sulfated, heparin like domains (27). Each of these contains two regions rich in iduronic acid tri- and disulfated disaccharides and tetra- and pentasulfated tetrasaccharids typical of heparin. Moreover, expression of syndecan-4 in cells incapable of proper 2-O-sulfation, results in a proteoglycan that fails to promote FGF2-receptor interaction, supporting the notion that 2-O-sulfated iduronic acid rich domains in HS are crucial for its FGF promoting activity.
[0036] Overexpression of syndecan-4 in wild type CHO cells results in self-association of the core protein and the formation of SDS resistant dimers. A similar phenomenon was reported for syndecan-3, where self-association was suggested to be mediated by a unique structural motif in the protein transmembrane domain (33). This domain is highly conserved among, the different syndecans and may, therefore, share a similar function in syndecan-4 as well. No dimers or higher order oligomers of soluble syndecan-4, lacking the transmembrane domain were detected, suggesting that indeed the sequence responsible for self-association reside within the transmembrane or intracellular domain of syndecan-4. Of special interest is the observation that in HS deficient cells these dimers were significantly less prevalent than in wild type CHO cells, where practically all or most of the syndecan-4 is present as core protein dimers. This may imply that the attached polysaccharide chains may actually enhance core protein association and dimerization. The functional consequences of syndecans self-association are not clear. It was suggested that such association might lead to cytoskeletal element coupling. This is supported by experiments demonstrating that antibody-mediated cross-linking of syndecan-1 in well spread Schwann cells, restored co-localization of the proteoglycan with actin filaments and a concomitant redistribution of cellular actin filaments (15).
[0037] Another, most likely related finding regarding syndecan-4, is the recent discovery that it is selectively enriched in focal adhesion contacts (48). A role for HSPGs in adhesion was previously suggested, based on the finding that adhesion defective cells have cell surface HSPGs of altered properties (49). The recruitment of syndecan-4 into focal contacts appears to be coordinately regulated by protein kinase-C (18) and phosphatidylinositol 4,5-biphosphate (19, 20). This recruitment involves direct association and phosphorylation of the C-terminus of syndecan-4 (50) and may serve to stabilize this region. FGFR1, like several other receptor tyrosine kinases, is found to be enriched in focal contacts (51). This co-localization of both FGFRs and accessory HSPGs such as syndecan-4 may serve as means for the local amplification of FGF signals. Alternatively, a role for FGF signaling in the stabilization of the focal contact structure can be suggested. In support for such a hypothesis is the observation that syndecan-4 is a primary response gene induced by FGF2 (52). FGF dependent modulation of focal contacts can drastically affect the adhesion and shape properties of the cell, which in turn may contribute to the well known effects of FGF on cell motility, migration and proliferation in a variety of biological processes such as wound healing and angiogenesis.
[0038] The invention will now be illustrated by the following non-limiting Examples.
EXAMPLES
Experimental Procedures
[0039] Material: Heparin was obtained from Hepar Industries (Franklin, Ohio). Recombinant human FGF2 and FGF1 were kindly provided by American Cyanamid Company (Pearl River, N.Y.). Growth factors were iodinated by the chloramine T method as described previously (25). The specific activity was 1.2-1.7ร10 5 cpm/ng and the labeled preparation was stored for up to 3 weeks at โ70ยฐ C. Heparinase III and I were purchased from Sigma (St. Louis, Mo.). F12 and Dulbecco's modified Eagle's medium (DMEM), calf serum, fetal calf serum (FCS), penicillin, and streptomycin were obtained from Biological Industries (Beit-Haemek, Israel). G418 was purchased from GibcoBRL (Getthersb, Md.). Tissue culture dishes were purchased from Falcon Labware Division, Becton Dickinson (Oxnard, Calif.). Na 125 I and H 2 35 SO 4 were purchased from Amersham (Buckinghamshire, England). Triton X-100, nonidet P-40, para-nitro-phenyl phosphate, and all other chemicals were of reagent grade, and purchased from Sigma (St. Louis, Mo.). Anti-FGF2 monoclonal antibody, FB-8, was obtained from Sigma (Israel).
[0040] Cell linesโWild type chinese hamster ovary cells (CHO-KI), glycosaminoglycan deficient (Pgs-A745) or 2-O-sulfated heparan deficient mutants (Pgs-F17) were cultured in F12 medium supplemented with 10% FCS. NIH-3T3 cells were cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% bovine calf serum. Human embryonal kidney cells (293T) were cultured in DMEM supplemented with 10% FCS.
[0041] Purification of syndecan-4โSyndecan-4 was isolated from the conditioned medium of rabbit aortic endothelial cells by Sepharose CL-6B gel filtration followed by ion exchange chromatography on DEAE-cellulose as previously described (26, 27). The identity of the purified proteoglycan was confirmed by N-terminal sequencing (26).
[0042] Cloning and expression of syndecan-4 cDNA: Two oligonucleotide primers derived from Syndecan-4 sequence were synthesized; the forward primer, EDF. 5โฒ-CCCAAGCTTTGTGCTGTTGGAACCATGG, and reverse primer EDB: 5โฒ-GCGGATCCGCCTCATGCGTAGAACTCG) having Hind III and BamH I restriction sites at their 5โฒ ends, (underlined), respectively. The primers were used for PCR amplification (35 cycles of 1 min denaturation at 94ยฐ C., annealing for 2 min at 48ยฐ C., elongation for 1 minute at 72ยฐ C.) with several cDNA libraries (from human placenta, human carcinoma, mouse brain, and mouse liver) used as templates. The amplified products were resolved on a 1% agarose gel stained with ethidium bromide. A PCR fragment of the anticipated size (600 bp) amplified from mouse liver cDNA library was digested with Hind III and BamH I and subcloned into pBluescript KS+ (Stratagene, Calif.). The identity of the amplified fragment was determined by sequencing. A ฮป-zap cDNA library of 14-day mouse embryo (Stratagene, Calif.) was screened using the PCR product as a probe (hybridization and washing at 65ยฐ C.). Positive clones were plaque purified and excised into pBluescript KS+ plasmid according to the manufacturer's instructions. Clones were analyzed by PCR with EDF and EDB primers and their homology to the mouse, rat and human syndecan-4 was confirmed by sequence determination. The cloned mouse syndecan-4 is identical to that of the published sequence except for position 135 where alanine is replaced by a valine which is identical to the human amphiglycan sequence in that position (13). The obtained mouse syndecan-4 cDNA was excised from pBluescript KS+ by Xho I and Xba I and subcloned into the same sites of the pLSV mammalian expression vector (28).
[0043] Expression of full length syntlecan-4 in CHO cellsโSyndecan-4 in the pLSV expression vector was co-transfected into CHO-KI and Pgs-A745 cells, with a selectable neomycin resistance gene, by the calcium phosphate method. Clones were selected in G418 (0.5 mg/ml) and screened for syndecan-4 expression by direct binding of antibodies directed against the extracellular domain of syndecan-4, or by metabolic labeling of cells with 35 S-sulfuric acid (150 ฮผCi for 24-48 hours).
[0044] Construction and expression Of chimeric soluble Syn-1-Fc, Syn-2-Fc, Syn-3-Fc and Syn-4-FcโTo express soluble syndecan-1, -2, -3, and -4, we used the immunoglobulin chimeric expression vector CDM7 (Invitrogen, Calif.). For example, the extracellular part of syndecan-4 was amplified by PCR (35 cycles of 1 min denaturation at 94ยฐ C., annealing for 2 minutes at 56ยฐ C. and elongation for 1 minute at 72ยฐ C.) using syndecan-4-pBlueScript as template DNA, the EDF forward primer and the reverse primer EDMB: 5โฒ-CGGGATCCTCAGTTCTCTCAAAGATG that contains a BamH I site (underlined). The purified PCR product was cut with Hind III/BamH I and subcloned in frame to a Fc portion (including the hinge region, CH2 and CH3 domains) of human IgG1, in the CDM7 vector, to create the fusion protein Syn4-Fc. The Syn4-Fc plasmid was co-transfected into 293T cells with the neomycin resistance gene, by electroporation using Gene Pulser (Bio-Rad, Calif.) set at 960 ฮผF and 250 V. Individual clones were selected with G418 (0.6 mg/ml) and screened for Fc secretion by dot-blot of conditioned media (100 ฮผl) with horse-radish-peroxidase (HRP) coupled anti-human Fc antibody (Sigma, Israel). The chimeric molecules with syndecan- 1, -2 and -3 were obtained in the same way.
[0045] Preparation of anti-syndecan-4 antibodiesโPolyclonal antibodies were prepared against a 12 amino acid long peptide (P710), with a sequence identical to the carboxy-terminus of syndecan-4. A cysteine residue was added at the amino-terminus of the peptide and was used for conjugation to keyhole limpet hemocyanin (KLH) (Calbiochem, Calif.) with m-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS) (Pierce, Ill.). The conjugates then served as antigens for immunization of New Zealand white rabbits. After three injections, the animals were bled and the titer and specificity of the antiserum were determined by immunoprecipitation of HSPGs from labeled lysates of human fetal lung fibroblasts and by competition for binding to syndecan-4 by the specific peptide. An IgG fraction was isolated on a Protein A column according to the manufacturer's instructions (Repligen, Mass.).
[0046] In vitro binding of FGFRs to FGFs immobilized on syndecan-4. Syndecan-4 was extracted from overexpressing cells in lysis buffer (150 mM NaCl, 20 mM Tris pH 8.0, 1 mM MgCl 2 , 0.1 mM ZnCl 2 , 0.5% NP-40, 1 ฮผg/ml aprotinin, 1 ฮผg/ml leupeptin, 2 mM PMSF) and cell lysates were clarified by centrifugation. Total cell extracts (100 ฮผg protein) were immunoprecipitated with polyclonal anti-syndecan-4 antibody (P710). Alternatively, Syn4-Fc fusion protein was immobilized directly on Protein A-Sepharose. FGF (50 ng) was bound to immobilized syndecan-4 for 2 hours at 4ยฐ C. The beads were washed extensively with HNTG (150 mM NaCl, 10% glycerol, 0.1% Triton-X-100 and 50 mM Hepes pH 7.4) and incubated for 2 hours with conditioned media containing the soluble FGFR1 or FGFR2-alkaline phosphatase (FR1-AP and FR2-AP, respectively) fusion proteins (29-31) followed by a 0.5 M wash to eliminate non specific binding of the receptor to HS. Alkaline phosphatase activity was monitored spectrophotometrically at 405 nm using para-nitro-phenyl phosphate as a substrate, as described (29). The extent of soluble FR-AP binding was determined by measuring alkaline phosphatase activity associated with the beads after extensive washing with HNTG.
[0047] Binding of FGFs to immobilized FR1-APโFR1 -AP and FR2-AP fusion proteins were immunoprecipitated with anti AP antibodies and incubated for 4 hours with 125 I-FGF1 and 125 I-FGF2, in the presence or absence of 1 ฮผg/ml heparin, syndecan-4 or HS-chains, in binding buffer (1% BSA and 25 mM Hepes in DMEM). The binding medium was then discarded and the cells were washed twice with binding buffer and once with 0.5M NaCl in 25mM Hepes pH 7.5. High affinity bound FGFs were eluted with a buffer of 1.6 M NaCl in 20 mM Sodium Acetate pH 4.5 and counted in a ฮณ-counter.
[0048] [0048] 35 S-sulfate and 3H-leucine labeling of cellsโPost-confluent cultures in 24-well plate were incubated for 24-36 hours in the appropriate medium supplemented with 10% fetal bovine serum, containing 20 ฮผCi/ml of H 2 35 SO 4 or 10 ฮผCi/ml of 3 H-leucine. The cells were washed twice with PBS, and scraped in a small volume of lysis buffer. The cell lysates were clarified by centrifugation and the amount of radioactive material in the pellet was measured by liquid scintillation. Alternatively, if soluble Syn4-Fc was labeled, the conditioned medium was collected and the protein was separated on Protein A-Sepharose.
[0049] Purification of syndecan-4 from overexpressing cellsโIgG fraction of anti P710 antibody was dialysed against 0.1 M NaHCO 3 , 0.5 M NaCl pH 8.3 and coupled to activated Sepharose 4B (Pharmacia, Sweden) according to the manufacturer's instructions. The enriched fraction of total HSPGs from KI-E5 cells, obtained by absorption on DEAE-cellulose (Pharmacia, Sweden) was eluted with 1 M NaCl, 0.1% Triton-x-100. The DEAE eluate was diluted 1:3 in double distilled water and loaded on an affinity column. Syndecan-4 was eluted with 0.2 M glycine/HCl pH 2.5 and neutralized immediately with 1 M Tris pH 8.0.
[0050] Purification of soluble Syn4-Fc from tie conditioned medium of overexpressing cellsโThe chimeric proteoglycan was observed on DEAE-cellulose and eluted with 1 M NaCl, 0.1% Triton-x-100. DEAE eluate was diluted 1:5 in double distilled water and loaded on FPL-Q HiTrap mini column (Pharmacia, Sweden). The column was washed with 75 mM Tris/HCl pH 7.3 and proteins were eluted by 0-1 M NaCl gradient in the same buffer. Syn4-Fc eluted at 0.7 M NaCl was detected by dot blot with horseradish-peroxidase coupled anti-human Fc antibody. Purity was determined by SDS-PAGE and silver staining, and both proteins and glycosaminoglycans were quantitated using the Bradford protein assay (Bio-Rad, Calif.) or the dimethylmethylene blue (32), respectively.
Example 1
[0051] Characterization of an endothelial cell derived syndecan-4 โSyndecan-4 (EDHS in FIG. 1) purified from the conditioned medium of rabbit aortic endothelial cells (26) was examined for its effects on FGF2 binding to FGFR1. In contrast to several other HSPGs (23), a strong induction of FGF2 binding was observed in the presence of syndecan-4 (FIG. 1, left panel). Syndecan-4 also enhanced the binding of FGF1 to soluble FGFR1 (FIG. 1, right panel). Heparan sulfate chains isolated from syndecan-4 by protease treatment (27) had a somewhat stronger effect on the interactions of both ligands with FGFR1 compared to that of the intact proteoglycan (FIG. 1). The effect of purified syndecan-4 is dose dependent with maximal activity at 1 ฮผg/ml while high concentrations (10 ฮผg/ml and higher) inhibit FGF2 binding (not shown), similar to the inhibition observed with high doses of heparin. These results demonstrate that syndecan-4 can efficiently enhance the interactions of FGF1 and FGF2 with their high affinity receptor.
Example 2
[0052] Ectopically expressed mouse syn(lecan-4 is post-translationally modified and expressed as a cell surface HSPGโIn order to study the role of syndecan-4 and its HS chains in modulating FGF-receptor interactions, mouse syndecan-4 was overexpressed in CHO-KI and in Pgs-A745-CHO mutant cells deficient in glycosaminoglycans. Positive clones identified by direct binding of monoclonal anti-syndecan-4 antibodies were selected and further tested for expression by immunoblotting (not shown). Measuring radioactive sulfate incorporated into syndecan-4 expressing CHO-KI clones normalized for total syndecan-4 (FIG. 2A) suggests that the ectopically expressed syndecan-4 represent 30-50% of the total HSPG in these cells. Higher levels of expression of syndecan-4 did not lead to increased sulfate labeling (FIG. 2A, clone KI-E5), suggesting that the glycosaminoglycan modifying enzymes may be limiting. Upon heparinase treatment, a single protein band with an apparent molecular mass of 65 kDa was identified in the wild type cells (FIG. 2B, clone KI-E5). In Pgs-A745 clones, on the other hand, two protein bands of molecular mass of 35 and 65 kDa were observed and the 35 kDa form always appeared as the predominant species (FIG. 2B). Similar results were obtained for all positive clones tested (not shown). Clone E10 was chosen for further characterization. The molecular mass of syndecan-4 is 19.25 kDa, as predicted from the cDNA open reading frame. However, both rat and human syndecan-4 were reported to behave anomalously on SDS-PAGE and to migrate at an apparent molecular weight of 33 kDa (16), an abnormality characteristic of all syndecans (17). The high molecular weight form (ca. 65 kDa), even under the denaturing and reducing conditions used, most likely represents denaturation resistant dimers, a phenomenon previously observed for N-syndecanlsyndecan-3 (33).
Example 3
[0053] Syndecan-4 binds FGF2 and promotes its binding to FGFR1โEctopically expressed syndecan-4 efficiently binds FGF2 in vitro as demonstrated by co-precipitation of the proteoglycan and detection by immunoblot with specific anti-FGF2 antibodies (FIG. 3A). Immunoprecipitated syndecan-4 from clone KI-E10 binds approximately 3-fold more FGF2 than syndecan-4 from the CHO-KI parental cells. Immunoprecipitates from either parental pgs-A745 CHO cells or clone 745-E4 bound only minor amounts of FGF2. These results indicate that syndecan-4 associated HS chains are responsible for the binding of FGF2. Moreover, the ratio of dimers to monomers of FGF2 is higher in the KI-E10 IP, indicating that syndecan-4 not only binds FGF2 but can also enhance its dimerization. FGF2 bound to syndecan-4 was also bound with high affinity to FGFR1 (FIG. 3B). Binding of FGF2 to immobilized FGFR-1 was tripled in the presence of syndecan-4 isolated from clone E10 overexpressing the ectopic proteoglycan.
Example 4
[0054] Soluble chimeric syndecan-4 is post-translationaly modified and can modulate FGF-receptor interactionsโIn order to further study the effects of syndecan-4 on ligand-receptor interactions, a chimeric protein (Syn4-Fc), in which the extracellular part of syndecan-4 was fused to the Fc portion of human IgG1, was generated. The Syn4-Fc was secreted into the conditioned medium of transfected 293T cells, and isolated using Protein A chromatography. SDS-PAGE analysis of conditioned medium from transfected cells, pretreated with heparinase, revealed three protein bands that can be detected by labeled anti-human Fc antibodies (FIG. 4A). A major protein band migrated at ห60 kDa, somewhat higher than the expected molecular weight of the chimeric fusion protein. This is consistent with the abnormal migration pattern observed for the full length core protein the two additional bands at 33 and 50 kDa represent most likely the Fc portion and a partial degradation product of the fusion protein, respectively.
[0055] The Syn4-Fc chimeric protein is post-translationally modified by HS chains as was demonstrated by metabolic labeling with 35 S-sulfate (FIG. 4B). Co-labeling with 3 H-leucine and H 2 35 SO 4 enabled us to estimate the relative amount of protein and sugar in the chimeric proteoglycan by measuring radioactivity with the appropriate energy window for each isotope ( 35 S or 3 H). The results are summarized in Table 1. The ratio between the two isotopes is 1.54ยฑ0.07 for all the samples, indicating that there is a constant ratio of sulfated sugar to protein in all the selected Syn4-Fc secreting clones. Radiolabeled Syn4-Fc from different clones was further analyzed by SDS-PAGE, before and after heparinase treatment (FIG. 4B). The intact proteoglycan appeared as a broad band at 200-220 kDa in all Syn4-Fc preparations tested. Following heparinase treatment the chimeric core protein appeared as a single band with the expected molecular mass of 60 kDa (FIG. 4B). No dimers or higher order oligomers of soluble syndecan-4 were observed suggesting that the transmembrane and/or the short intracellular segments of syndecan-4 may be directly responsible for the spontaneous dimerization observed for the intact proteoglycan.
TABLE 1 Metabolic labeling of Syn-4-Fc fusion protein. Positive clones expressing Syn4-Fc fusion protein were metabolically labeled with both 35 S-sulfuric acid and 3H-leucine for 24 hours. The condition medium was collected and immobilized on Protein A-Sepharose. Five percent of each sample was subjected to liquid scintillation counting (using the 3 H and 35 S energy windows), and the 3 H to 35 S ratio was determined. Clone 35 S(cpm) 3 H(cpm) 35 SO 4 / 3 H-Leu โ1 41113 26360 1.56 18 14784 โ9725 1.52 20 23059 15819 1.46 24 23114 14266 1.62
[0056] To test the ability of soluble syndecan-4 to promote binding of FGF2 to FGFR1, the conditioned medium from Syn4-Fc expressing cells was absorbed to Protein A beads, incubated with FGF2 and then reacted with soluble FR1-AP. Efficient binding of FR1-AP to immobilized Syn4-Fc-FGF2 complex was observed (FIG. 5A). Binding of FGFR1 also occurred when FGF1 was complexed with Syn4-Fc and was observed only in the presence of the ligands. The activity of Syn4-Fc appeared to be specific to the syndecan-4 part of the fusion protein, as Fc coupled to the extra-cellular part of the Erb4 receptor, used as a control, did not support FR1-AP binding. Treatment of Syn4-Fc with heparinase completely abolished FGF2 binding to FR1-AP (FIG. 5B), indicating that the interaction is via the HS chains and not the core protein. In agreement, no association of FGF2 and soluble FGFR1 with Syn4-Fc produced in HS deficient cells could be detected (not shown). Syn4-Fc was also capable of promoting the direct binding of 125 I-FGF2 to soluble FGFR2-AP (not shown).
Example 5
[0057] Syndecan-1, -2, -3 and -4 mediate selective binding of FGFs to FGF receptorsโThe ability of several FGFs to interact with FGF receptors when immobilized on Syn-1, -2, -3 and -4-Fc was compared to their capacity to form specific FGF/FGFR complexes on heparin sepharose. Syn4-Fc preferentially promotes the interaction of bFGF with FGFR1, and with about 2 fold less to FGR2, as measured by alkaline phosphatase activity and cross-linking of the receptors to radio-labeled bFGF. A similar activity was found for aFGF. Most interestingly, high affinity binding of FGF4, FGF7 or FGF9, to their related FGFRs is not enhanced by Syn4-Fc. In contrast, all FGFs tested, demonstrated a high affinity receptor binding when immobilized on heparin sepharose. These results (summarized in Table 2 for Syn4-Fc and in FIG. 6 for Syn1-Fc, Syn2-Fc and Syn4-Fc) directly demonstrate that specific modulators of FGFs.
TABLE 2 Specificity of Syn4-Fc as a modulator of FGFs interactions. Heparin sepharose or conditioned medium (100 ฮผl) from 293 Syn4-Fc clone #1 immobilized on protein-A sepharose were incubated with 75 ng of the indicated factor. After washes with HNTG the beads were further incubated for 2 hours with the indicated FGFR-AP fusion protein and the bound receptors were determined after extensive washes according to the AP enzymatic activity. FGF FGFR Heparin Syn 4-Fc 1 1 +++ +++ 1 2 +++ ++ 1 2IIIb +++ + 1 3 ++ + 2 1 +++ +++ 2 2 +++ ++ 4 1 +++ โ 4 2 +++ โ 4 2IIIb +++ โ 4 3 +++ โ 7 2IIIb ++ โ 9 2 ++ โ 9 3 +++ โ
Example 6
[0058] Syn4-Fc promotes FGF1 mediated proliferation of FGFR1 expressing cellsโTo study the capacity of syndecan-4 to elicit a heparin-dependent biological response to FGF, we made use of the HS deficient pgs-A745-CHO cells, transfected with FGFR1. These cells were previously shown to efficiently bind FGF2 only in the presence of heparin (25). As shown in FIG. 5C, the cells did not respond to FGF1 in the absence of heparin as measured by DNA synthesis. However, upon the addition of either heparin or purified Syn4-Fc, a clear mitogenic response to FGF1 is observed. Incorporation of 3 H-thymidine was enhanced at 100 ng/ml of Syn4-Fc similar to the effect of 100 ng/ml heparin (FIG. 5C). Syn4-Fc or heparin alone had no effect. These results clearly indicate that syndecan-4 can substitute for heparin in mediating heparin-mediated dependent cell proliferation.
Example 7
[0059] [0059] 2 -O-sulfated iduronic acid is required for syndecan-4 mediated FGF-receptor bindingโIt was previously shown that the heparin structure required to promote FGF2-receptor binding consists of highly sulfated oligosaccharides of at least 10 sugar units in length (21, 34, 35). The sulfation at 2-OH of the ฮฑ-L-iduronic acid is of special importance and is found in heparin and in HS fragments with high affinity for FGF2 and FGF1 (34, 36). To test the role of this specific modification in the activity of the intact proteoglycan, we expressed Syn4-Fc in Pgs-F17 cells, a mutant CHO cell line deficient of 2-O-sulfotransferase (37). Syn4-Fc produced by these cells had a lower molecular weight (FIG. 6A) and a dramatically reduced affinity towards FGF2. FGF2 pre-bound to heparin, Syn4-Fc or Pgs-F17 made Syn4-Fc, eluted at 1.5, 0.9 and 0.5 M NaCl, respectively (not shown). No binding of FR1-AP to either FGF2 or FGF1 was observed when tested in the presence of the 2-O-sulfate deficient syndecan-4 compared to 293T derived syndecan-4-proteoglycan (FIG. 6B), despite comparable levels of Syn4-Fc core protein. Full-length syndecan-4 expressed in Pgs-F17 cells does not support FGF-FGFR binding as well, similar in that respect to syndecan-4 isolated from HS deficient Pgs-A745 cells. Altogether, these results show that 2-O-sulfation of syndecan-4 glycosaminoglycan chains, is crucial for their activity as modulators of FGF-FGFR interactions.
REFERENCES
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1
12
1
1327
DNA
Mus musculus
1
aggcgcttga tatcgaattc cggaattccg gaattccgga attccggaat tccgctgttg 60
aagccatggc gcctgcctgc ctgcttgcgc cgctgctgct gctgctcctc ggaggcttcc 120
ccttggtccc cggagagtcg attcgagaga cagaggtcat cgacccccag gacctcctgg 180
aaggcagata cttctctgga gccctccccg acgacgaaga tgctggcggc tcggatgact 240
ttgagctctc gggttctgga gatctggatg acacggagga gcccaggccc ttccctgaag 300
tgattgagcc cttggtgcca ctggataacc acatccctga gaatgcacag cctggcatcc 360
gtgtcccctc agagcccaag gaactggaag agaatgaggt cattcctaaa agggccccct 420
ccgacgtggg ggatgacatg tccaacaaag tatccatgtc cagcactgtc cagggcagca 480
acatctttga gagaactgag gtcttggcag ctctgatcgt gggcggcgtg gtaggcatcc 540
tctttcccgt tttcctgatc ctgctgctgg tgtaccgcat gaagaagaag gacgaaggca 600
gttacgactt gggcaagaaa cccatctaca aaaaagcccc caccaaggag ttctacgcat 660
gaagcttcct cccgcgagcg ctgcttggac ttattgggga gaggagtgga gggttgtggg 720
tggcgggcgt tggcagagag cagcaggcac cttaatgctg acttgtcagt atctccatct 780
ctagtcacct ttctggtgtc agaagagatg tgatcttcta ctgtgctgcc tgagagagag 840
agagagagag agagagagag agagagaggg gctgtgtctg tgtgtctgtg tctcagttgc 900
tctggcagaa aaatggggtt aaacttgccc tttctgaagg caagcctaca attgggtctt 960
ttgttgtcat tgttccaaat ttccagaaat agaatatagg accagtttag atcctgtagt 1020
aaacatgtcc catctatgac tgccttgatt atagaggcaa ggggttactg tgtgaatccc 1080
ggctcccttc cacatgctgt acaccctatc catctgtcag gagctggggc aaggagccaa 1140
accctctgca ccttgagatg agtctgccat gagaacttgc tcacgctgca gagtctctgt 1200
ggcgtacctg ggggcattct aagtccagtg acttttgaaa ttcaaccttt aaaaaaaaaa 1260
aaatctaggg agggcggggt ggagtgctga aagctcacac tgaagtgtgt ttggatgctc 1320
tgaacta 1327
2
198
PRT
Mus musculus
2
Met Ala Pro Ala Cys Leu Leu Ala Pro Leu Leu Leu Leu Leu Leu Gly
1 5 10 15
Gly Phe Pro Leu Val Pro Gly Glu Ser Ile Arg Glu Thr Glu Val Ile
20 25 30
Asp Pro Gln Asp Leu Leu Glu Gly Arg Tyr Phe Ser Gly Ala Leu Pro
35 40 45
Asp Asp Glu Asp Ala Gly Gly Ser Asp Asp Phe Glu Leu Ser Gly Ser
50 55 60
Gly Asp Leu Asp Asp Thr Glu Glu Pro Arg Pro Phe Pro Glu Val Ile
65 70 75 80
Glu Pro Leu Val Pro Leu Asp Asn His Ile Pro Glu Asn Ala Gln Pro
85 90 95
Gly Ile Arg Val Pro Ser Glu Pro Lys Glu Leu Glu Glu Asn Glu Val
100 105 110
Ile Pro Lys Arg Ala Pro Ser Asp Val Gly Asp Asp Met Ser Asn Lys
115 120 125
Val Ser Met Ser Ser Thr Val Gln Gly Ser Asn Ile Phe Glu Arg Thr
130 135 140
Glu Val Leu Ala Ala Leu Ile Val Gly Gly Val Val Gly Ile Leu Phe
145 150 155 160
Pro Val Phe Leu Ile Leu Leu Leu Val Tyr Arg Met Lys Lys Lys Asp
165 170 175
Glu Gly Ser Tyr Asp Leu Gly Lys Lys Pro Ile Tyr Lys Lys Ala Pro
180 185 190
Thr Asn Glu Phe Tyr Ala
195
3
311
PRT
Mus musculus
3
Met Arg Arg Ala Ala Leu Trp Leu Trp Leu Cys Ala Leu Ala Leu Arg
1 5 10 15
Leu Gln Pro Ala Leu Pro Gln Ile Val Ala Val Asn Val Pro Pro Glu
20 25 30
Asp Gln Asp Gly Ser Gly Asp Asp Ser Asp Asn Phe Ser Gly Ser Gly
35 40 45
Thr Gly Ala Leu Pro Asp Thr Leu Ser Arg Gln Thr Pro Ser Thr Trp
50 55 60
Lys Asp Val Trp Leu Leu Thr Ala Thr Pro Thr Ala Pro Glu Pro Thr
65 70 75 80
Ser Ser Asn Thr Glu Thr Ala Phe Thr Ser Val Leu Pro Ala Gly Glu
85 90 95
Lys Pro Glu Glu Gly Glu Pro Val Leu His Val Glu Ala Glu Pro Gly
100 105 110
Phe Thr Ala Arg Asp Lys Glu Lys Glu Val Thr Thr Arg Pro Arg Glu
115 120 125
Thr Val Gln Leu Pro Ile Thr Gln Arg Ala Ser Thr Val Arg Val Thr
130 135 140
Thr Ala Gln Ala Ala Val Thr Ser His Pro His Gly Gly Met Gln Pro
145 150 155 160
Gly Leu His Glu Thr Ser Ala Pro Thr Ala Pro Gly Gln Pro Asp His
165 170 175
Gln Pro Pro Arg Val Glu Gly Gly Gly Thr Ser Val Ile Lys Glu Val
180 185 190
Val Glu Asp Gly Thr Ala Asn Gln Leu Pro Ala Gly Glu Gly Ser Gly
195 200 205
Glu Gln Asp Phe Thr Phe Glu Thr Ser Gly Glu Asn Thr Ala Val Ala
210 215 220
Ala Val Glu Pro Gly Leu Arg Asn Gln Pro Pro Val Asp Glu Gly Ala
225 230 235 240
Thr Gly Ala Ser Gln Ser Leu Leu Asp Arg Lys Glu Val Leu Gly Gly
245 250 255
Val Ile Ala Gly Gly Leu Val Gly Leu Ile Phe Ala Val Cys Leu Val
260 265 270
Ala Phe Met Leu Tyr Arg Met Lys Lys Lys Asp Glu Gly Ser Tyr Ser
275 280 285
Leu Glu Glu Pro Lys Gln Ala Asn Gly Gly Ala Tyr Gln Lys Pro Thr
290 295 300
Lys Gln Glu Glu Phe Tyr Ala
305 310
4
211
PRT
Rattus norvegicus
4
Met Arg Val Arg Ala Thr Ser Pro Gly Asn Met Gln Arg Ala Trp Ile
1 5 10 15
Leu Leu Thr Leu Gly Leu Met Ala Cys Val Ser Ala Glu Thr Arg Ala
20 25 30
Glu Leu Thr Ser Asp Lys Asp Met Tyr Leu Asp Ser Ser Ser Ile Glu
35 40 45
Glu Ala Ser Gly Leu Tyr Pro Ile Asp Asp Asp Asp Tyr Ser Ser Ala
50 55 60
Ser Gly Ser Gly Ala Tyr Glu Asp Lys Gly Ser Pro Asp Leu Thr Thr
65 70 75 80
Ser Gln Leu Ile Pro Arg Ile Ser Leu Thr Ser Ala Ala Pro Glu Val
85 90 95
Glu Thr Met Thr Leu Lys Thr Gln Ser Ile Thr Pro Thr Gln Thr Glu
100 105 110
Ser Pro Glu Glu Thr Asp Lys Lys Glu Phe Glu Ile Ser Glu Ala Glu
115 120 125
Glu Lys Gln Asp Pro Ala Val Lys Ser Thr Asp Val Tyr Thr Glu Lys
130 135 140
His Ser Asp Asn Leu Phe Lys Arg Thr Glu Val Leu Ala Ala Val Ile
145 150 155 160
Ala Gly Gly Val Leu Gly Phe Leu Phe Ala Ile Phe Leu Ile Leu Leu
165 170 175
Leu Val Tyr Arg Met Arg Lys Lys Asp Glu Gly Ser Tyr Asp Leu Gly
180 185 190
Glu Arg Lys Pro Ser Ser Ala Ala Tyr Gln Lys Ala Pro Thr Lys Glu
195 200 205
Phe Tyr Ala
210
5
353
PRT
Mus musculus
5
Leu Arg Glu Thr Ala Met Arg Phe Ile Pro Asp Ile Ala Leu Ala Ala
1 5 10 15
Pro Thr Ala Pro Ala Met Leu Pro Thr Thr Val Ile Gln Pro Val Asp
20 25 30
Thr Pro Phe Glu Glu Leu Leu Ser Glu His Pro Gly Pro Glu Pro Val
35 40 45
Thr Ser Pro Pro Leu Val Thr Glu Val Thr Glu Val Val Glu Glu Pro
50 55 60
Ser Gln Arg Ala Thr Thr Ile Ser Thr Thr Thr Ser Thr Thr Ala Ala
65 70 75 80
Thr Thr Thr Gly Ala Pro Thr Met Ala Thr Ala Pro Ala Thr Ala Ala
85 90 95
Thr Thr Ala Pro Ser Thr Pro Ala Ala Pro Pro Ala Thr Ala Thr Thr
100 105 110
Ala Asp Ile Arg Thr Thr Gly Ile Gln Gly Leu Leu Pro Leu Pro Leu
115 120 125
Thr Thr Ala Ala Thr Ala Lys Ala Thr Thr Pro Ala Val Pro Ser Pro
130 135 140
Pro Thr Thr Val Thr Thr Leu Asp Thr Glu Ala Pro Thr Pro Arg Leu
145 150 155 160
Val Asn Thr Ala Thr Ser Arg Pro Arg Ala Leu Pro Arg Pro Val Thr
165 170 175
Thr Gln Glu Pro Glu Val Ala Glu Arg Ser Thr Leu Pro Leu Gly Thr
180 185 190
Thr Ala Pro Gly Pro Thr Glu Val Ala Gln Thr Pro Thr Pro Glu Ser
195 200 205
Leu Leu Thr Thr Thr Gln Asp Glu Pro Glu Val Pro Val Ser Gly Gly
210 215 220
Pro Ser Gly Asp Phe Glu Leu Gln Glu Glu Thr Thr Gln Pro Asp Thr
225 230 235 240
Ala Asn Glu Val Val Ala Val Glu Gly Ala Ala Ala Lys Pro Ser Pro
245 250 255
Pro Leu Gly Thr Leu Pro Lys Gly Ala Arg Pro Gly Leu Gly Leu His
260 265 270
Asp Asn Ala Ile Asp Ser Gly Ser Ser Ala Ala Gln Leu Pro Gln Lys
275 280 285
Ser Ile Leu Glu Arg Lys Glu Val Leu Val Ala Val Ile Val Gly Gly
290 295 300
Val Val Gly Ala Leu Phe Ala Ala Phe Leu Val Thr Leu Leu Ile Tyr
305 310 315 320
Arg Met Lys Lys Lys Asp Glu Gly Ser Tyr Thr Leu Glu Glu Pro Lys
325 330 335
Gln Ala Ser Val Thr Tyr Gln Lys Pro Asp Lys Gln Glu Glu Phe Tyr
340 345 350
Ala
6
202
PRT
Rattus norvegicus
6
Met Ala Pro Val Cys Leu Phe Ala Pro Leu Leu Leu Leu Leu Leu Gly
1 5 10 15
Gly Phe Pro Val Ala Pro Gly Glu Ser Ile Arg Glu Thr Glu Val Ile
20 25 30
Asp Pro Gln Asp Leu Leu Glu Gly Arg Tyr Phe Ser Gly Ala Leu Pro
35 40 45
Asp Asp Glu Asp Ala Gly Gly Leu Glu Gln Asp Ser Asp Phe Glu Leu
50 55 60
Ser Gly Ser Gly Asp Leu Asp Asp Thr Glu Glu Pro Arg Thr Phe Pro
65 70 75 80
Glu Val Ile Ser Pro Leu Val Pro Leu Asp Asn His Ile Pro Glu Asn
85 90 95
Ala Gln Pro Gly Ile Arg Val Pro Ser Glu Pro Lys Glu Leu Glu Glu
100 105 110
Asn Glu Val Ile Pro Lys Arg Val Pro Ser Asp Val Gly Asp Asp Asp
115 120 125
Val Ser Asn Lys Val Ser Met Ser Ser Thr Ser Gln Gly Ser Asn Ile
130 135 140
Phe Glu Arg Thr Glu Val Leu Ala Ala Leu Ile Val Gly Gly Val Val
145 150 155 160
Gly Ile Leu Phe Ala Val Phe Leu Ile Leu Leu Leu Val Tyr Arg Met
165 170 175
Lys Lys Lys Asp Glu Gly Ser Tyr Asp Leu Gly Lys Lys Pro Ile Tyr
180 185 190
Lys Lys Ala Pro Thr Asn Glu Phe Tyr Ala
195 200
7
198
PRT
Homo sapiens
7
Met Ala Pro Ala Arg Leu Phe Ala Leu Leu Leu Leu Phe Val Gly Gly
1 5 10 15
Val Ala Glu Ser Ile Arg Glu Thr Glu Val Ile Asp Pro Gln Asp Leu
20 25 30
Leu Glu Gly Arg Tyr Phe Ser Gly Ala Leu Pro Asp Asp Glu Asp Val
35 40 45
Val Gly Pro Gly Gln Glu Ser Asp Asp Phe Glu Leu Ser Gly Ser Gly
50 55 60
Asp Leu Asp Asp Leu Glu Asp Ser Met Ile Gly Pro Glu Val Val His
65 70 75 80
Pro Leu Val Pro Leu Asp Asn His Ile Pro Glu Arg Ala Gly Ser Gly
85 90 95
Ser Gln Val Pro Thr Glu Pro Lys Lys Leu Glu Glu Asn Glu Val Ile
100 105 110
Pro Lys Arg Ile Ser Pro Val Glu Glu Ser Glu Asp Val Ser Asn Lys
115 120 125
Val Ser Met Ser Ser Thr Val Gln Gly Ser Asn Ile Phe Glu Arg Thr
130 135 140
Glu Val Leu Ala Ala Leu Ile Val Gly Gly Ile Val Gly Ile Leu Phe
145 150 155 160
Ala Val Phe Leu Ile Leu Leu Leu Met Tyr Arg Met Lys Lys Lys Asp
165 170 175
Glu Gly Ser Tyr Asp Leu Gly Lys Lys Pro Ile Tyr Lys Lys Ala Pro
180 185 190
Thr Asn Glu Phe Tyr Ala
195
8
197
PRT
Gallus gallus
8
Met Pro Leu Pro Arg Ala Ala Phe Leu Leu Gly Leu Leu Leu Ala Ala
1 5 10 15
Ala Ala Ala Glu Ser Val Arg Glu Thr Glu Thr Met Asp Ala Arg Trp
20 25 30
Leu Asp Asn Val Gly Ser Gly Asp Leu Pro Asp Asp Glu Asp Ile Gly
35 40 45
Glu Phe Thr Pro His Leu Thr Ser Asp Glu Phe Asp Ile Asp Asp Thr
50 55 60
Ser Gly Ser Gly Asp Tyr Ser Asp Tyr Asp Asp Ala Ile Tyr Leu Thr
65 70 75 80
Thr Val Asp Thr Pro Ala Ile Ser Asp Asn Tyr Ile Pro Gly Asp Thr
85 90 95
Glu Arg Lys Met Glu Gly Glu Lys Lys Asn Thr Met Leu Asp Asn Glu
100 105 110
Ile Ile Pro Asp Lys Ala Ser Pro Val Glu Ala Asn Leu Ser Asn Lys
115 120 125
Ile Ser Met Ala Ser Thr Ala Asn Ser Ser Ile Phe Glu Arg Thr Glu
130 135 140
Val Leu Thr Ala Leu Ile Ala Gly Gly Ala Val Gly Leu Leu Phe Ala
145 150 155 160
Val Phe Leu Ile Leu Leu Leu Val Tyr Arg Met Lys Lys Lys Asp Glu
165 170 175
Gly Ser Tyr Asp Leu Gly Lys Lys Pro Ile Tyr Lys Lys Ala Pro Thr
180 185 190
Asn Glu Phe Tyr Ala
195
9
28
DNA
Artificial sequence
synthetic oligonucleotide
9
cccaagcttt gtgctgttgg aaccatgg 28
10
27
DNA
Artificial sequence
synthetic oligonucleotide
10
gcggatccgc ctcatgcgta gaactcg 27
11
26
DNA
Artificial sequence
synthetic oligonucleotide
11
cgggatcctc agttctctca aagatg 26
12
11
PRT
Artificial sequence
synthetic peptide
12
Ser Tyr Asp Leu Gly Lys Lys Pro Ile Tyr Lys
1 5 10
|
A molecule is provided capable of promoting high affinity binding of a fibroblast growth factor (FGF) to a FGF receptor (FGFR), said molecule being selected from: (i) a recombinant chimeric fusion molecule comprising the extracellular domain of a syndecan or a fragment thereof fused to a tag suitable for proteoglycan purification, said fusion molecule being post-translationally glycosylated to carry at least one chain of a heparan sulfate having at least one highly sulfated domain; (ii) a DNA sequence encoding a chimeric fusion molecule comprising the extracellular domain of a syndecan or a fragment thereof fused to a tag suitable for proteoglycan purification; and (iii) a sugar molecule from a syndecan carrying at least one chain of a heparan sulfate having at least one highly sulfated domain. The compounds may be used for induction of angiogenesis, bone fracture healing, enhancement of wound healing, promotion of tissue regeneration and treatment of ischemic heart diseases and peripheral vascular diseases.
| 2
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CROSS REFERENCE
[0001] This non-provisional application claims priority under 35 U.S.C. ยง119(a) to Patent Application No. 2011-194429 filed in Japan on Sep. 6, 2011, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a fluid control device which performs fluid control.
[0004] 2. Description of the Related Art
[0005] International Publication No. 2008/069264 discloses a conventional fluid pump (see FIGS. 1A to 1E ). FIG. 1A to FIG. 1E show operations of the conventional fluid pump in a tertiary mode. The fluid pump, as shown in FIG. 1A , includes a pump body 10 ; a vibrating plate 20 in which the outer peripheral portion thereof is attached to the pump body 10 ; a piezoelectric element 23 attached to the central portion of the vibrating plate 20 ; a first opening 11 formed on a portion of the pump body 10 that faces the approximately central portion of the vibrating plate 20 ; and a second opening 12 formed on either one of a region intermediate between the central portion and the outer peripheral portion of the vibrating plate 20 or a portion of the pump body 10 that faces the intermediate region.
[0006] The vibrating plate 20 is made of metal. The piezoelectric element 23 has a size so as to cover the first opening 11 and a size so as not to reach the second opening 12 .
[0007] In the above mentioned fluid pump, by applying voltage having a predetermined frequency to the piezoelectric element 23 , a portion of the vibrating plate 20 that faces the first opening 11 and a portion of the vibrating plate 20 that faces the second opening 12 are bent and deformed in opposite directions, as shown in FIG. 1A to FIG. 1E . This causes the fluid pump to draw fluid from one of the first opening 11 and the second opening 12 and to discharge the fluid from the other opening.
[0008] The above mentioned fluid pump, as is shown in FIG. 1A with a conventional structure, has a simple structure, and thus the thickness of the fluid pump can be made thinner. Such a fluid pump is used, for example, as an air transport pump of a fuel cell system.
[0009] At the same time, electronic equipment and apparatuses into which the fluid pump is incorporated have tended to be miniaturized. Therefore, it is necessary to further miniaturize the fluid pump without reducing the pump performance (the discharge flow rate and the discharge pressure) of the fluid pump.
[0010] However, the performance of the fluid pump decreases as the fluid pump becomes smaller. Therefore, there are limitations to miniaturizing the fluid pump having the conventional structure while maintaining the pump performance.
[0011] Accordingly, the inventors of the present invention have devised a fluid pump having a structure shown in FIG. 2 .
[0012] FIG. 2 is a sectional view showing a configuration of a main portion of the fluid pump 901 . The fluid pump 901 is provided with a base plate 39 , a flexible plate 35 , a spacer 37 , a vibrating plate 31 , and a piezoelectric element 32 . The fluid pump 901 is provided with a structure in which the components are layered in that order.
[0013] In the fluid pump 901 , the piezoelectric element 32 and the vibrating plate 31 bonded to the piezoelectric element 32 constitute an actuator 30 . A ventilation hole 35 A is formed in the center of the flexible plate 35 . The end of the vibrating plate 31 is fixed to the end of the flexible plate 35 by means of an adhesive via the spacer 37 . This means that the vibrating plate 31 is supported at a location spaced away from the flexible plate 35 by the thickness of the spacer 37 .
[0014] The base plate 39 is bonded to the flexible plate 35 . A cylindrical opening 40 is formed in the center of the base plate 39 . A portion of the flexible plate 35 is exposed to the side of the base plate 39 through the opening 40 of the base plate 39 . The circular exposed portion of the flexible plate 35 can vibrate at a frequency that is substantially the same as a frequency of the actuator 30 through the pressure fluctuation of fluid accompanied by the vibration of the actuator 30 . In other words, through the configuration of the flexible plate 35 and the base plate 39 , the portion of the flexible plate 35 that faces the opening 40 serves as a movable portion 41 that is capable of bending and vibrating. Furthermore, a portion on the outside of the movable portion 41 of the flexible plate 35 serves as a fixing portion 42 fixed to the base plate 39 .
[0015] In the above structure, when driving voltage is applied to the piezoelectric element 32 , the vibrating plate 31 bends and vibrates as a result of the expansion and contraction of the piezoelectric element 32 . Furthermore, the movable portion 41 of the flexible plate 35 vibrates with vibration of the vibrating plate 31 . This causes the fluid pump 901 to suction or discharge air through the ventilation hole 35 A. Consequently, since the movable portion 41 vibrates with the vibration of the actuator 30 , the amplitude of vibration of the fluid pump 901 is effectively increased. This allows the fluid pump 901 to produce a high discharge pressure and a large discharge flow rate despite the small size and low profile design thereof.
[0016] However, the fluid pump 901 is provided with a structure in which the components are layered. Each of the components is fixed by means of the adhesive agent. For this reason, as the temperature of the fluid pump 901 increased due to heat generation at a time of driving the fluid pump 901 or increases in an environmental temperature, each of the components bends according to differences in each of coefficients of linear expansion. As a result, a distance between the vibrating plate 31 and the flexible plate 35 varies. Here, the distance between the vibrating plate 31 and the flexible plate 35 is an important factor which affects the pressure-flow rate characteristics of the fluid pump 901 .
[0017] Therefore, a problem exists with the fluid pump 901 in which the pressure-flow rate characteristics of the fluid pump 901 will vary depending on changes in temperature. In other words, the temperature characteristics of the fluid pump 901 are poor.
SUMMARY OF THE INVENTION
[0018] Preferred embodiments of the present invention provide a fluid control device that significantly reduces and prevents variations in pressure-flow rate characteristics caused by changes in temperature.
[0019] A fluid control device according to a preferred embodiment of the present invention includes a vibrating plate unit, a driver, a flexible plate, and a base plate. The vibrating plate unit includes a vibrating plate including a first main surface and a second main surface, and a frame plate surrounding the surrounding of the vibrating plate. The driver is bonded to either one of the first main surface or the second main surface of the vibrating plate and vibrates the vibrating plate. The flexible plate includes a hole provided on the flexible plate, and is bonded to the frame plate to face the vibrating plate. The base plate is bonded to the main surface of the flexible plate on the side opposite to the vibrating plate. A size relationship between the coefficient of linear expansion of the material of the base plate and the coefficient of linear expansion of the material of the frame plate is equal to a size relationship between the coefficient of linear expansion of the material of either the vibrating plate or the driver, whichever is closer to the flexible plate, and the coefficient of linear expansion of the material of either the vibrating plate or the driver, whichever is farther from the flexible plate.
[0020] This configuration includes a first configuration and a second configuration in which the vibrating plate unit, the driver, the flexible plate, and the base plate all bend in different directions.
[0021] In the first configuration, either the vibrating plate or the driver, whichever is closer to the flexible plate, is made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of either the vibrating plate or the driver, whichever is farther from the flexible plate. Then, the base plate is made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the frame plate.
[0022] On the other hand, in the second configuration, either the vibrating plate or the driver, whichever is closer to the flexible plate, is made of a material having a coefficient of linear expansion that is smaller than the coefficient of linear expansion of either the vibrating plate or the driver, whichever is farther from the flexible plate. Then, the base plate is made of a material having a coefficient of linear expansion that is smaller than the coefficient of linear expansion of the frame plate.
[0023] With this configuration, the vibrating plate unit, the driver, the flexible plate, and the base plate are bonded to each other at a temperature higher than a normal temperature.
[0024] For this reason, in the first configuration, after the bonding at the normal temperature, the vibrating plate bends and forms a convex curve on the first main surface on the side opposite to the base plate due to the difference in the coefficients of linear expansion of the vibrating plate unit and the driver while the flexible plate bends and forms a convex curve on the main surface on the side provided with the driver (that is, the side opposite to the base plate) due to the difference in the coefficients of linear expansion of the vibrating plate unit and the base plate. On the other hand, in the second configuration, after the bonding at the normal temperature, the vibrating plate bends and forms a convex curve on the second main surface on the side of the base plate due to the difference in the coefficients of linear expansion of the vibrating plate unit and the driver, and the flexible plate bends and forms a convex curve on the main surface on the side of the base plate due to the difference in the coefficients of linear expansion of the vibrating plate unit and the base plate.
[0025] Therefore, with this configuration, in a case where the difference between the coefficient of linear expansion of the vibrating plate unit and the coefficient of linear expansion of the driver is nearly the same as the difference in the coefficients of linear expansion of the vibrating plate unit and the base plate, as the temperature of the fluid control device changes due to heat generated during the drive or due to changes in environmental temperature, both the bending of the vibrating plate as well as the flexible plate reduces by approximately the same amount.
[0026] Thus, with this configuration, as each material is selected for use in the vibrating plate unit, the driver, the flexible plate, and the base plate, even if the vibrating plate unit, the driver, the flexible plate, and the base plate deform, due to differences in coefficients of linear expansion when changes in temperature occur, the distance between the vibrating plate and the flexible plate will always remain approximately constant.
[0027] Consequently, the fluid control device can significantly reduce and prevent variations in the pressure-flow rate characteristics by changes in temperature.
[0028] Preferably, the driver is bonded to the first main surface of the vibrating plate on the side opposite to the base plate, and the flexible plate is bonded to the frame plate so as to face the second main surface of the vibrating plate on the side of the base plate, and the vibrating plate unit is made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the driver, and the base plate is made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the vibrating plate unit.
[0029] This configuration is included in the above described first configuration. With this configuration, after the bonding, at the normal temperature, the vibrating plate bends and forms a convex curve on the first main surface of the vibrating plate on the side of the driver due to the difference in the coefficients of linear expansion of the vibrating plate unit and the driver, and the flexible plate bends and forms a convex curve on the main surface on the side of the driver due to the difference in the coefficients of linear expansion of the vibrating plate unit and the base plate.
[0030] Preferably, the driver is bonded to the second main surface of the vibrating plate on the side of the base plate, and the flexible plate is bonded to the frame plate so as to face the second main surface of the vibrating plate on the side of the base plate, and the driver is made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the vibrating plate unit, and the base plate is made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the vibrating plate unit.
[0031] This configuration is included in the above described first configuration. With the configuration, after the bonding at the normal temperature, the vibrating plate bends and forms a convex curve on the first main surface opposite to the driver due to the difference between the coefficient of linear expansion of the vibrating plate unit and the coefficient of linear expansion of the driver, and the flexible plate bends and forms a convex curve on the main surface on the side of the driver due to the difference between the coefficient of linear expansion of the vibrating plate unit and the coefficient of linear expansion of the base plate.
[0032] Preferably, the vibrating plate unit may further include a link portion which links the vibrating plate and the frame plate, and elastically supports the vibrating plate against the frame plate.
[0033] With this configuration, the vibrating plate is flexibly and elastically supported against the frame plate by the link portion. For this reason, the bending vibration of the vibrating plate generated by expansion and contraction of the piezoelectric element cannot be blocked at all. Therefore, in the fluid control device, there will be a reduction in the loss caused by the bending vibration of the vibrating plate.
[0034] In addition, the flexible plate is preferably made of a material having a coefficient of linear expansion that is larger than the vibrating plate unit.
[0035] Also with this configuration, at the normal temperature, the flexible plate bends and forms a convex curve on the side of the driver due to the differences in the coefficients of linear expansion of the vibrating plate unit, the flexible plate, and the base plate. Additionally, both the bending of the vibrating plate and the flexible plate are reduced as the temperature of the fluid control device increases due to heat generation at the time of driving the fluid control device or by changes of environmental temperature.
[0036] Preferably, the vibrating plate forms a convex curve on the side opposite to the base plate, and is elastically supported by the link portion against the frame plate, and the flexible plate forms a convex curve on the side of the driver, and is bonded to the base plate.
[0037] With this configuration, at the normal temperature, the vibrating plate bends and forms a convex curve on the side of the driver due to the difference in the coefficients of linear expansion of the vibrating plate unit and the driver, and the flexible plate bends and forms a convex curve on the main surface on the side of the driver due to the difference in the coefficients of linear expansion of the vibrating plate unit and the base plate. Thus, both the bending of the vibrating plate and the flexible plate are reduced as the temperature of the fluid control device increases due to heat generation at the time of driving the fluid control device or due to changes in environmental temperature.
[0038] Also it is preferable for the vibrating plate and the link portion to be thinner than the thickness of the frame plate, so that surfaces of the vibrating plate and the link portion on the side of the flexible plate separate from the flexible plate.
[0039] With this configuration, the surface of the link portion on the side of the flexible plate is spaced away from the flexible plate by a predetermined distance. Therefore, even if the adhesive agent flows into a gap between the link portion and the flexible plate when the frame plate and the flexible plate are fixed preferably by the adhesive agent, the fluid control device can prevent the link portion and the flexible plate from adhering to each other.
[0040] Similarly, with this configuration, the surface of the vibrating plate on the side of the flexible plate is spaced away from the flexible plate by a predetermined distance. For this reason, even if an excess amount of the adhesive agent flows into a gap between the vibrating plate and the flexible plate when the frame plate and the flexible plate are fixed preferably by the adhesive agent, the fluid control device can prevent the vibrating plate and the flexible plate from adhering to each other.
[0041] Thus, the fluid control device can prevent the vibration of the vibrating plate from being blocked and can prevent the vibrating plate, the link portion, and the flexible plate from adhering to each other.
[0042] Moreover, it is preferable for a hole portion to be formed in a region of the flexible plate facing the link portion.
[0043] With this configuration, when the frame plate and the flexible plate are fixed preferably by the adhesive agent, an excess amount of the adhesive agent flows into the hole portion. For that reason, the fluid control device can further prevent the vibrating plate and the link portion, and the flexible plate from adhering to one another. In other words, the fluid control device can further prevent the vibration of the vibrating plate from being blocked by the adhesive agent.
[0044] In addition, preferably, the vibrating plate and the driver constitute an actuator, and the actuator has a disk shaped configuration.
[0045] With this configuration, the actuator vibrates in a rotationally symmetric pattern (a concentric circular pattern). For this reason, an unnecessary gap is not generated between the actuator and the flexible plate. Therefore, the fluid control device enhances operation efficiency as a pump.
[0046] Preferably, the flexible plate includes a movable portion that is positioned in the center or near the center of the region of the flexible plate on a side facing the vibrating plate and can bend and vibrate, and a fixing portion that is positioned outside the movable portion in the region and is substantially fixed.
[0047] According to this configuration, the movable portion vibrates with vibration of the actuator. For this reason, in the fluid control device, the amplitude of vibration is effectively increased. Thus, the fluid control device can achieve a higher discharge pressure and a larger discharge flow rate despite the small size and low profile design thereof.
[0048] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1A to FIG. 1E are cross-sectional views of a main part of a conventional fluid pump.
[0050] FIG. 2 is a cross-sectional view of a main portion of a fluid pump 901 according to a comparative example of the present invention.
[0051] FIG. 3 is an external perspective view of a piezoelectric pump 101 according to a preferred embodiment of the present invention.
[0052] FIG. 4 is an exploded perspective view of the piezoelectric pump 101 as shown in FIG. 3 .
[0053] FIG. 5 is a cross-sectional view of the piezoelectric pump 101 as shown in FIG. 3 taken along line T-T.
[0054] FIG. 6A is a cross-sectional view of a main portion of the piezoelectric pump 101 as shown in FIG. 3 at normal temperature, and FIG. 6B is a cross-sectional view of the main portion of the piezoelectric pump 101 as shown in FIG. 3 at high temperature.
[0055] FIG. 7 is a plan view of a bonding body of the vibrating plate unit 160 and the flexible plate 151 as shown in FIG. 4 .
[0056] FIG. 8A is a cross-sectional view of a main portion of a piezoelectric pump 201 at normal temperature according to another preferred embodiment of the present invention, and FIG. 8B is a cross-sectional view of the main portion of the piezoelectric pump 201 at high temperature according to another preferred embodiment of the present invention.
[0057] FIG. 9A is a cross-sectional view of a main portion of a piezoelectric pump 301 at normal temperature according to another preferred embodiment of the present invention, and FIG. 9B is a cross-sectional view of the main portion of the piezoelectric pump 301 at high temperature according to another preferred embodiment of the present invention.
[0058] FIG. 10A is a cross-sectional view of a main portion of a piezoelectric pump 401 at normal temperature according to another preferred embodiment of the present invention, and FIG. 10B is a cross-sectional view of the main portion of the piezoelectric pump 401 at high temperature according to another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0059] Hereinafter, a piezoelectric pump 101 will be described according to a first preferred embodiment of the present invention.
[0060] FIG. 3 is an external perspective view of the piezoelectric pump 101 according to the first preferred embodiment of the present invention. FIG. 4 is an exploded perspective view of the piezoelectric pump 101 as shown in FIG. 3 . FIG. 5 is a cross-sectional view of the piezoelectric pump 101 as shown in FIG. 3 taken along line T-T.
[0061] As shown in FIG. 3 to FIG. 5 , the piezoelectric pump 101 preferably includes a cover plate 195 , a base plate 191 , a flexible plate 151 , a vibrating plate unit 160 , a piezoelectric element 142 , a spacer 135 , an electrode conducting plate 170 , a spacer 130 , and a lid portion 110 . The piezoelectric pump 101 is provided with a structure in which the above components are layered in that order.
[0062] A vibrating plate 141 has an upper surface facing the lid portion 110 , and a lower surface facing the flexible plate 151 .
[0063] The piezoelectric element 142 is fixed to the upper surface of the vibrating plate 141 preferably by an adhesive agent. The upper surface of the vibrating plate 141 is equivalent to the โfirst main surfaceโ according to a preferred embodiment of the present invention. Both the vibrating plate 141 and the piezoelectric element 142 preferably are disc shaped. In addition, the vibrating plate 141 and the piezoelectric element 142 define a disc shaped actuator 140 . The vibrating plate unit 160 that includes the vibrating plate 141 is formed of a metal material which has a coefficient of linear expansion greater than the coefficient of linear expansion of the piezoelectric element 142 . By applying heat to cure the vibrating plate 141 and the piezoelectric element 142 at time of adhesion, an appropriate compressive stress can be left on the piezoelectric element 142 which allows the vibrating plate 141 to bend and form a convex curve on the side of the piezoelectric element 142 . This compressive stress can prevent the piezoelectric element 142 from cracking. For example, it is preferred for the vibrating plate unit 160 to be formed of SUS430. For example, the piezoelectric element 142 may be made of lead titanate zirconate-based ceramics. The coefficient of linear expansion for the piezoelectric element 142 is nearly zero, and the coefficient of linear expansion for SUS430 is about 10.4ร10 โ6 K โ1 .
[0064] It should be noted that the piezoelectric element 142 is equivalent to the โdriverโ according to a preferred embodiment of the present invention.
[0065] The thickness of the spacer 135 may preferably be the same as, or slightly thicker than, the thickness of the piezoelectric element 142 .
[0066] The vibrating plate unit 160 preferably includes the vibrating plate 141 , the frame plate 161 , and a link portion 162 . The vibrating plate unit 160 is preferably integrally formed by etching a metal plate, for example. The vibrating plate 141 has the frame plate 161 provided therearound. The vibrating plate 141 is linked to the frame plate 161 by the link portion 162 . Additionally, the frame plate 161 is fixed to the flexible plate 151 preferably by the adhesive agent.
[0067] The vibrating plate 141 and the link portion 162 are preferably thinner than the thickness of the frame plate 161 so that the surfaces of the vibrating plate 141 and the link portion 162 on the side of the flexible plate 151 may separate from the flexible plate 151 . The vibrating plate 141 and the link portion 162 are preferably made thinner than the thickness of the frame plate 161 by half etching the surfaces of the vibrating plate 141 and the link portion 162 on the side of the flexible plate 151 . Accordingly, a distance between the vibrating plate 141 and the link portion 162 , and the flexible plate 151 is accurately determined to a predetermined size (15 ฮผm, for example) by the depth of the half etching. The link portion 162 has an elastic structure having the elasticity of a small spring constant.
[0068] Therefore, the vibrating plate 141 is flexibly and elastically supported preferably at three points against the frame plate 161 by three link portions 162 , for example. For this reason, the bending vibration of the vibrating plate 141 cannot be blocked at all. In other words, the piezoelectric pump 101 has a structure in which the peripheral portion of the actuator 140 (as well as the central portion) is not substantially fixed.
[0069] It is to be noted that the flexible plate 151 , an adhesive agent layer 120 , the frame plate 161 , the spacer 135 , the electrode conducting plate 170 , the spacer 130 , and the lid portion 110 constitute a pump housing 180 . Additionally, the interior space of the pump housing 180 is equivalent to a pump chamber 145 .
[0070] The spacer 135 is adhesively fixed to an upper surface of the frame plate 161 . The spacer 135 preferably is made of resin. The thickness of the spacer 135 is the same as or slightly thicker than the thickness of the piezoelectric element 142 . Additionally, the spacer 135 constitutes a portion of the pump housing 180 . Moreover, the spacer 135 electrically insulates the electrode conducting plate 170 , described below, with the vibrating plate unit 160 .
[0071] The electrode conducting plate 170 is adhesively fixed to an upper surface of the spacer 135 . The electrode conducting plate 170 is preferably made of metal. The electrode conducting plate 170 includes a frame portion 171 which is a nearly circular opening, an inner terminal 173 which projects into the opening, and an external terminal 172 which projects to the outside.
[0072] The leading edge of the inner terminal 173 is soldered to the surface of the piezoelectric element 142 . The vibration of the inner terminal 173 can be significantly reduced and prevented by setting a soldering position to a position equivalent to a node of the bending vibration of the actuator 140 .
[0073] The spacer 130 is adhesively fixed to an upper surface of the electrode conducting plate 170 . The spacer 130 is preferably made of resin. The spacer 130 is a spacer that prevents the soldered portion of the inner terminal 173 from contacting the lid portion 110 when the actuator 140 vibrates. The spacer also prevents the surface of the piezoelectric element 142 from coming too close to the lid portion 110 , thus preventing the amplitude of vibration from reducing due to air resistance. For this reason, the thickness of the spacer 130 may be equivalent to the thickness of the piezoelectric element 142 .
[0074] The lid portion 110 with a discharge hole 111 formed thereon is bonded to an upper surface of the spacer 130 . The lid portion 110 covers the upper portion of the actuator 140 . Therefore, air sucked through a ventilation hole 152 , to be described below, of the flexible plate 151 is discharged from the discharge hole 111 .
[0075] Here, the discharge hole 111 is a discharge hole which releases positive pressure in the pump housing 180 which includes the lid portion 110 . Therefore, the discharge hole 111 need not necessarily be provided in the center of lid portion 110 .
[0076] An external terminal 153 is arranged on the flexible plate 151 to connect electrically. In addition, a ventilation hole 152 is formed in the center of the flexible plate 151 .
[0077] On a lower surface of the flexible plate 151 , the base plate 191 is attached preferably by the adhesive agent. A cylindrical opening 192 is formed in the center of the base plate 191 . A portion of the flexible plate 151 is exposed to the base plate 191 at the opening 192 of the base plate 191 . The circularly exposed portion of the flexible plate 151 can vibrate at a frequency substantially the same as a frequency of the actuator 140 through the fluctuation of air pressure accompanying the vibration of the actuator 140 . In other words, with the configuration of the flexible plate 151 and the base plate 191 , a portion of the flexible plate 151 facing the opening 192 serves as the circular movable portion 154 capable of bending and vibrating. The movable portion 154 corresponds to a portion in the center or near the center of the region facing the actuator 140 of the flexible plate 151 . Furthermore, a portion positioned outside the movable portion 154 of the flexible plate 151 serves as the fixing portion 155 that is fixed to the base plate 191 . The characteristic frequency of the movable portion 154 is designed to be the same as or slightly lower than the driving frequency of the actuator 140 .
[0078] Accordingly, in response to the vibration of the actuator 140 , the movable portion 154 of the flexible plate 151 also vibrates with large amplitude, centering on the ventilation hole 152 . If the vibration phase of the flexible plate 151 is a vibration phase delayed (for example, 90 degrees delayed) from the vibration of the actuator 140 , the thickness variation of a gap between the flexible plate 151 and the actuator 140 increases substantially. Through this, the piezoelectric pump 101 can improve pump performance (the discharge pressure and the discharge flow rate).
[0079] The cover plate 195 is bonded to a lower surface of the base plate 191 . Three suction holes 197 are provided in the cover plate 195 . The suction holes 197 communicate with the opening 192 through a passage 193 formed in the base plate 191 .
[0080] The flexible plate 151 , the base plate 191 , and the cover plate 195 are preferably made of a material having a coefficient of linear expansion that is greater than a coefficient of linear expansion of the vibrating plate unit 160 . In addition, the flexible plate 151 , the base plate 191 , and the cover plate 195 are preferably made of a material having approximately the same coefficient of linear expansion. For example, it is preferable to have the flexible plate 151 that is made of substances such as beryllium copper. It is preferable to have the base plate 191 that is made of substances such as phosphor bronze. It is preferable to have the cover plate 195 that is made of substances such as copper. These coefficients of linear expansion are approximately 17ร10 โ6 K โ1 . Moreover, it is preferable to have the vibrating plate unit 160 that is made of SUS430. The coefficient of linear expansion of SUS430 is about 10.4ร10 โ6 K โ1 .
[0081] In this case, due to the differences in the coefficients of linear expansion of the flexible plate 151 , the base plate 191 , and the cover plate 195 in relation to the frame plate 161 , by applying heat to cure the flexible plate 151 at a time of adhesion, a tension which makes the flexible plate 151 bend and form a convex curve on the side of the piezoelectric element 142 , is applied to the flexible plate 151 . Thus, a tension which makes the movable portion capable of bending and vibrating is adjusted on the movable portion 154 . Furthermore, the vibration of the movable portion 154 is not blocked due to any slack on the movable portion 154 . It is to be understood that since the beryllium copper which constitutes the flexible plate 151 is a spring material, even if the circular movable portion 154 vibrates with large amplitude, there will be no permanent set in fatigue or similar symptoms. In other words, beryllium copper has excellent durability.
[0082] In the above structure, when a driving voltage is applied to the external terminals 153 , 172 , the actuator 140 of the piezoelectric pump 101 concentrically bends and vibrates. Furthermore, in the piezoelectric pump 101 , the movable portion 154 of the flexible plate 151 vibrates from the vibration of the vibrating plate 141 . Thus, the piezoelectric pump 101 sucks air from the suction hole 197 to the pump chamber 145 through the ventilation hole 152 . Then, the piezoelectric pump 101 discharges the air in the pump chamber 145 from the discharge hole 111 . In this state of the piezoelectric pump 101 , the peripheral portion of the vibrating plate 141 is not substantially fixed. For that reason, the piezoelectric pump 101 achieves significantly lower loss caused by the vibration of the vibrating plate 141 , while being small and low profile, and can obtain a high discharge pressure and a large discharge flow rate.
[0083] In addition, in the piezoelectric pump 101 , the surface of the link portion 162 on the side of the flexible plate 151 is separated from the flexible plate 151 . Therefore, the piezoelectric pump 101 can prevent the link portion 162 and the flexible plate 151 from adhering to each other even if an excess amount of the adhesive agent flows into a gap between the link portion 162 and the flexible plate 151 .
[0084] Similarly, in the piezoelectric pump 101 , the lower surface of the vibrating plate 141 on the side of the flexible plate 151 is separated from flexible plate 151 . For that reason, the piezoelectric pump 101 can prevent the vibrating plate 141 and the flexible plate 151 from adhering to each other even if the excess amount of the adhesive agent flows into a gap between the vibrating plate 141 and the flexible plate 151 . Here, the lower surface of the vibrating plate 141 is equivalent to the โsecond main surfaceโ according to a preferred embodiment of the present invention.
[0085] Thus, the piezoelectric pump 101 can prevent the vibrating plate 141 and the link portion 162 and the flexible plate 151 from adhering to each other and blocking the vibration of the vibrating plate 141 .
[0086] Additionally, in the piezoelectric pump 101 , a difference between the thickness of the vibrating plate 141 and the thickness of the frame plate 161 is equivalent to a distance between the vibrating plate 141 and the flexible plate 151 . In other words, in the piezoelectric pump 101 , the distance that affects the pressure-flow rate characteristics is determined by the depth of the half etching to the vibrating plate 141 .
[0087] It is possible to achieve precise setting of the depth of the half etching. Thus, the piezoelectric pump 101 can prevent the pressure-flow rate characteristics from fluctuating with each piezoelectric pump 101 .
[0088] FIG. 6A is a cross-sectional view of the main portion at normal temperature of the piezoelectric pump 101 as shown in FIG. 3 , and FIG. 6B is a cross-sectional view of the main portion at high temperature of the piezoelectric pump 101 as shown in FIG. 3 . Here, for illustrative purposes, FIG. 6A highlights the bending of the bonding body of the vibrating plate unit 160 , the piezoelectric element 142 , the flexible plate 151 , the base plate 191 , and the cover plate 195 in a scale that is larger than reality. Additionally, in FIGS. 6A and 6B , the lid portion 110 , the spacer 130 , the electrode conducting plate 170 , and the spacer 135 are omitted in the drawing for illustrative purposes.
[0089] In the piezoelectric pump 101 , the piezoelectric element 142 , the vibrating plate unit 160 , the flexible plate 151 , the base plate 191 , and the cover plate 195 are bonded, for example, by an adhesive agent at a temperature (about 120 degrees, for example) higher than a normal temperature (about 20 degrees) (see FIG. 6B ). Thus, after the bonding at the normal temperature, the vibrating plate 141 bends and forms a convex curve on the side of the piezoelectric element 142 due to the difference between the coefficient of linear expansion of the vibrating plate unit 160 and the coefficient of linear expansion of the piezoelectric element 142 . Furthermore, the flexible plate 151 bends and forms a convex curve on the side of the piezoelectric element 142 due to the difference between the coefficient of linear expansion of the above mentioned vibrating plate unit 160 and the coefficient of linear expansion of the base plate 191 (see FIG. 6A ).
[0090] At the normal temperature, the vibrating plate 141 and the flexible plate 151 bend and form convex curves on the side of the piezoelectric element 142 by approximately the same amount. Then, both the bending of the vibrating plate 141 and the flexible plate 151 are reduced by approximately the same amount as the temperature of the piezoelectric pump 101 increases due to heat generation at the time of driving the piezoelectric pump 101 or due to changes in environmental temperature.
[0091] Therefore, even if the vibrating plate unit 160 , the piezoelectric element 142 , the flexible plate 151 , and the base plate 191 deform by the difference in each of the coefficients of linear expansion due to changes in temperature, the distance between the vibrating plate 141 and the flexible plate 151 is always maintained constant by selecting each material for the vibrating plate unit 160 , the piezoelectric element 142 , the flexible plate 151 , and the base plate 191 as described above.
[0092] Consequently, the piezoelectric pump 101 can significantly reduce and prevent a variation in the pressure-flow rate characteristics caused by changes in temperature. That is, the piezoelectric pump 101 can maintain proper pressure-flow rate characteristics of a pump over a wide temperature range.
[0093] FIG. 7 is a plan view of a bonding body of the vibrating plate unit 160 and the flexible plate 151 as shown in FIG. 4 .
[0094] As shown in FIG. 4 to FIG. 7 , it is preferable that a hole portion 198 is provided in the region facing the link portion 162 in the flexible plate 151 and the base plate 191 . Thus, when the frame plate 161 and the flexible plate 151 are fixed preferably by the adhesive agent, an excess amount of the adhesive agent flows into the hole portion 198 .
[0095] Therefore, the piezoelectric pump 101 can further prevent the vibrating plate 141 and the link portion 162 and the flexible plate 151 from adhering to each other. In other words, the piezoelectric pump 101 can further prevent the vibration of the vibrating plate 141 from being blocked.
[0096] It is to be noted that in the piezoelectric pump 101 , the lid portion 110 may be fixed to the spacer 130 using a silicone adhesive having low elasticity, for example. Alternatively, in place of the lid portion 110 and the spacer 130 , a bulb structure defined by a resin molded article, rubber, and other suitable material may be fixed to the electrode conducting plate 170 using the silicone adhesive having low elasticity, for example. With the former configuration, generation of thermal stress between the lid portion 110 and the spacer 130 is suppressed with by the silicone adhesive of low elasticity. Moreover, with the latter configuration, generation of thermal stress between the bulb structure and the electrode conducting plate 170 is suppressed by the silicone adhesive of low elasticity.
[0097] As described above, when the generation of thermal stress is significantly reduced and prevented, the deformation of the vibrating plate unit 160 and the base plate 191 due to changes in the temperature of the piezoelectric pump 101 cannot be blocked. In other words, the effects of the lid portion 110 and the bulb structure are eliminated. For that reason, the piezoelectric pump 101 can further reduce and prevent variations in the pressure-flow rate characteristics by changes in temperature.
Other Preferred Embodiments
[0098] In the above described preferred embodiments, as shown in FIG. 6A and FIG. 6B , while the actuator 140 is configured preferably by bonding the piezoelectric element 142 to the upper surface of the vibrating plate 141 on the side opposite to the flexible plate 151 , the configuration is not limited thereto. In a piezoelectric pump 201 as shown in FIG. 8A and FIG. 8B , for example, an actuator 240 may be configured by bonding the piezoelectric element 142 to the lower surface of the vibrating plate 141 on the side of the flexible plate 151 . However, in the piezoelectric pump 201 as shown in FIG. 8A and FIG. 8B , the piezoelectric element 142 is preferably made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the vibrating plate unit 160 .
[0099] While the actuator 140 having a unimorph type structure and undergoing bending vibration was preferably provided in the above mentioned preferred embodiments, the structure is not limited thereto. For example, it is possible to attach a piezoelectric element 142 on both sides of the vibrating plate 141 so as to have a bimorph type structure and undergo bending vibration.
[0100] Moreover, in the above described preferred embodiments, while the actuator 140 which undergoes bending vibration by expansion and contraction of the piezoelectric element 142 was preferably provided, the method is not limited thereto. For example, an actuator which electromagnetically undergoes bending vibration may be provided.
[0101] In the preferred embodiments, while the piezoelectric element 142 is preferably made of lead titanate zirconate-based ceramics, the material is not limited thereto. For example, an actuator may be made of a piezoelectric material of non-lead based piezoelectric ceramics such as potassium-sodium niobate based or alkali niobate based ceramics.
[0102] While the above-mentioned preferred embodiment shows an example in FIG. 6A in which the vibrating plate unit 160 , the flexible plate 151 , and the base plate 191 preferably form convex curves on the side of the piezoelectric element 142 at normal temperature, the structure is not limited thereto. For example, even if the vibrating plate unit 160 , the piezoelectric element 142 , the flexible plate 151 , and the base plate 191 deform due to the difference in each of the coefficients of linear expansion caused by changes in temperature, as long as the distance can always remain constant between the vibrating plate 141 and the flexible plate 151 , the configuration such as the piezoelectric pump 301 as shown in FIG. 9A may be used. In other words, as shown in FIG. 9A , at normal temperature, the vibrating plate unit 160 , the flexible plate 151 , and the base plate 191 may form convex curves on the sides opposite to the piezoelectric element 142 . However, in the piezoelectric pump 301 as shown in FIG. 9A and FIG. 9B , the piezoelectric element 142 is preferably made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the vibrating plate unit 160 , and the vibrating plate unit 160 is preferably made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the base plate 191 .
[0103] In addition, in the piezoelectric pump 301 as shown in FIG. 9A and FIG. 9B , while the actuator 140 is configured preferably by bonding the piezoelectric element 142 to the upper surface of the vibrating plate 141 on the side opposite to the flexible plate 151 , the configuration is not limited thereto. In a piezoelectric pump 401 as shown in FIG. 10A and FIG. 10B , for example, the actuator 240 may be configured by bonding the piezoelectric element 142 to the lower surface of the vibrating plate 141 on the side of the flexible plate 151 . However, in the piezoelectric pump 401 as shown in FIG. 10A and FIG. 10B , the piezoelectric element 142 is preferably made of a material having a coefficient of linear expansion that is larger than the coefficient of linear expansion of the vibrating plate unit 160 .
[0104] Additionally, while the above described preferred embodiments showed an example in which the piezoelectric element 142 and the vibrating plate 141 preferably have roughly the same size, there are no limitations to the size. For example, the vibrating plate 141 may be larger than the piezoelectric element 142 .
[0105] Moreover, although the disc shaped piezoelectric element 142 and the disc shaped vibrating plate 141 were preferably included in the above mentioned preferred embodiments, there are no limitations to the shape. For example, either of the piezoelectric element 142 or the vibrating plate 141 can be a rectangle or a polygon.
[0106] In addition, while a thickness of the entire vibrating plate 141 is preferably thinner than the thickness of the frame plate 161 , there are no limitations to the thickness. For example, the thickness of at least a portion of the vibrating plate 141 may be preferably thinner than the thickness of the frame plate 161 . However, a portion of the vibrating plate 141 is preferred to be an end of the vibrating plate, of the entire vibrating plate 141 , nearest to an adhesion portion between the flexible plate 151 and the frame plate 161 .
[0107] Moreover, in the above described preferred embodiment, while the link portion 162 is preferably provided at three spots, the number of places is not limited thereto. For example, the link portion 162 may be provided at only two spots or the link portion 162 may be provided at four or more spots. Although the link portion 162 does not block vibration of the actuator 140 , the link portion 162 does more or less affect the vibration of the actuator 140 . Therefore, the actuator 140 can be held naturally by linking (holding) the actuator at three spots, for example, and the position of the actuator 140 is held accurately. The piezoelectric element 142 can also be prevented from cracking.
[0108] Furthermore, the actuator 140 may be driven in an audible frequency band in various preferred embodiments of the present invention if it is used in an application in which the generation of audible sounds does not cause problems.
[0109] In addition, while the above described preferred embodiments show an example in which one ventilation hole 152 is disposed at the center of a region facing the actuator 140 of the flexible plate 151 , there are no limitations to the number of holes. For example, a plurality of holes may be disposed near the center of the region facing the actuator 140 .
[0110] Further, while the frequency of driving voltage in the above mentioned preferred embodiments is determined so as to make the actuator 140 vibrate in a primary mode, there are no limitations to the mode. For example, the driving voltage frequency may be determined so as to vibrate the actuator 140 in other modes such as a tertiary mode.
[0111] In addition, while air is used as fluid in the above mentioned preferred embodiments, the fluid is not limited thereto. For example, any kind of fluid such as liquids, gas-liquid mixture, solid-liquid mixture, and solid-gas mixture can be applied to the above preferred embodiment.
[0112] While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
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A fluid control device includes a vibrating plate unit, a driver, a flexible plate, and a base plate. The vibrating plate unit includes a vibrating plate including first and second main surfaces, and a frame plate surrounding the surrounding of the vibrating plate. The driver is bonded to the first or the second main surface of the vibrating plate and vibrates the vibrating plate. The flexible plate includes a hole provided therein, and is bonded to the frame plate so as to face the vibrating plate. The base plate is bonded to the main surface of the flexible plate on a side opposite to the vibrating plate. A size relationship between the coefficients of linear expansion of the material of the base plate and the frame plate is equal to a size relationship between the coefficients of linear expansion of the material of the vibrating plate and the driver.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to cast in place concrete walls and, more particularly, to a method of forming a cast in place concrete wall wherein the resultant wall has a substantially smooth and uniform outer surface texture.
2. Description of the Related Art
As is well known in the construction industry, concrete is a commonly used material for the fabrication of walls and barriers. The desirability of the use of concrete as a construction material is attributable to certain characteristics that concrete possesses in comparison to other construction materials. More particularly, walls and barriers may be quickly and easily constructed through the use of concrete, with the concrete also imparting a high level of durability to such structures. In addition, the use of concrete for the fabrication of walls and barriers offers a high level of design flexibility since the concrete may be molded into many different shapes and arrangements. The concrete is also easily transportable to construction sites via concrete transport trucks.
Many of the concrete walls that are constructed in accordance with the current state of the art are referred to as cast in place walls. A concrete cast in place wall is typically constructed on-site rather than being manufactured at an off-site facility and subsequently transported to the construction site. The fabrication of a cast in place concrete wall typically begins with the construction of a concrete wall form. Subsequent to the construction of such form, concrete is poured thereinto and is given time to cure. Once the concrete has cured, the corresponding wall form is removed from the fully formed concrete structure. Upon the removal of the form, the exposed walls of the concrete structure may be sandblasted to apply a finishing texture thereto.
One of the deficiencies associated with the currently known cast in place wall construction methodology is that the resultant wall or other structure tends to have a roughened surface texture upon the removal of the form therefrom. In this regard, there tends to be slight inconsistencies in the overall finish of the wall or other structure, such inconsistencies being caused by any one of a number of different factors, including inconsistencies in the form work, sandblasting, finishing, concrete and/or the placing or pumping of the concrete into the form. Further, small holes or other indentations are often found throughout the exposed surfaces of the wall or other structure, such holes or other indentations being formed as a result of the entrapment of air during the forming process. These holes or other indentations are undesirable, in as much as they diminish the aesthetic appeal of the wall or other structure.
In order to avoid the surface finish inconsistencies highlighted above, there has been developed in the prior art a method of creating uniform texture concrete walls. In accordance with this methodology, the concrete wall is โpre cast,โ with the cast face of the wall being side down and the wall being erected into place through the use of a crane. However, this particular process is not well suited to forming concrete structures wherein multiple faces or sides of the structure are to be provided with a substantially uniform texture, The present invention addresses this need in the art by providing a methodology for forming concrete structures such as walls or barriers having substantially smooth or uniform exterior surface textures.
BRIEF SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a method of forming a cast in place concrete wall having a substantially uniform exterior surface texture. As indicated above, concrete is a commonly used construction material that comprises aggregate of various shapes and sizes disposed in cement. The method of the present invention includes the initial step of constructing or assembling a concrete wall form in a suitable size and shape, and thereafter pouring a first concrete mixture into the wall form. The concrete poured from such first mixture is allowed to partially cure once poured into the form. Once the concrete is at least partially cured, the wall form is removed from the resultant base structure. Subsequent to the form removal, the cured concrete structure is subjected to a procedure which creates a roughened surface texture on the exposed exterior surfaces thereof. Such roughened surface texture may be formed through the use of a form retarder, a spray on retarder, sand blasting, acid washing, and/or chemical etching.
Subsequent to the roughening of the exposed surfaces of the base structure, a finishing mixture is then applied to such roughened surfaces. In accordance with the present invention, the finishing mixture may be created by separating the aggregate from a portion of the remainder of the first mixture used to initially form the base structure. However, such finishing mixture may also be formed by separating the aggregate from a second mixture of the concrete, wherein such second mixture is a separate batch of concrete from the first mixture. The finishing mixture, however derived, is applied to the initially formed base structure to create a smooth/uniform texture over the roughened exterior surfaces thereof. As will be recognized, the fully cured finishing mixture ultimately defines the exposed exterior surfaces of the concrete structure (e.g., a wall, barrier, etc) comprising the combination of the base structure having the finishing mixture applied thereto.
As is apparent from the foregoing, the present invention provides a method of constructing a concrete structure such as a cast in place wall having substantially more uniform exterior surface textures then those which can be achieved by the formation of cast in place walls using presently known techniques. By separating at least the large aggregate from the concrete batch used to create the finishing mixture, the application of such finishing mixture to the initially formed base structure is operative to cover any inconsistencies that may otherwise have been present in such base structure. It is contemplated that the finishing mixture may be applied through the use of a float which is operative to work the finishing mixture into any holes or other detents disposed in the initially formed base structure. The surface of the finishing mixture may also be troweled to achieve a harder texture. The exposed surface of the finishing mixture itself may also be acid washed after the finishing mixture is allowed to harden to a prescribed level.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:
FIG. 1 is a perspective view of a cast in place concrete wall constructed in accordance with techniques known in the prior art;
FIG. 2 is a perspective view of a section of concrete poured into a wall form;
FIG. 3 is a perspective view of a section of the concrete from FIG. 2 , wherein the wall form has been removed and a roughened surface has been applied to the cured concrete base structure;
FIG. 4 is a perspective view of a section of the concrete base structure from
FIG. 3 wherein a finishing mixture is being applied to the roughened surface at the base structure; and
FIG. 5 is a perspective view of a concrete wall constructed in accordance with the method of the present invention.
Common reference numerals are used throughout the drawings and detailed description to indicate like elements.
DETAILED DESCRIPTION OF THE INVENTION
The detailed description set forth below is intended as a description of the presently preferred embodiment of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the functions and sequences of steps for constructing and operating the invention. It is to be understood, however, that the same or equivalent functions and sequences may be accomplished by different embodiments and that they are also intended to be encompassed within the scope of the invention.
As indicated above, cast in place concrete walls provide numerous advantages over walls constructed from other building materials. In this regard, cast in place walls may be quickly and easily constructed, and provide substantial flexibility in the size and shape of the wall. However, as also indicated above, cast in place walls constructed in accordance with most prior art fabrication methodologies often include an undesirable rough, non-uniform exterior surface texture. In this regard, when the concrete is poured into the corresponding wall form, air may become entrapped in small pockets within the concrete. When the concrete cures and the wall form is removed, these air pockets may appear as inconsistencies on the exposed surfaces of the resultant wall. These inconsistencies in the wall surface are typically considered to be aesthetically undesirable. FIG. 1 illustrates a cast in place wall constructed though the use of known, prior art methodologies. As is shown in FIG. 1 small holes or indentations 2 formed as a result of entrapped air in the concrete poured into wall form used to form the wall are present in various locations on the exposed, exterior surfaces thereof.
The present invention is directed toward creating a cast in place wall having a more uniform texture on its surface, thereby increasing its aesthetic appeal. Referring now to FIGS. 2-5 , there is provided a method of constructing a cast in place concrete wall 10 or other concrete structure having a substantially uniform exterior surface texture. Concrete 12 is a commonly used building material that is comprised of cement, water, aggregates, and admixtures. Admixtures are materials that are added to the concrete 12 to give it certain characteristics that it otherwise would not have, such as accelerating or retarding the stetting time, enhancing frost and sulfate resistance, improving workability, and enhancing finishinability. The aggregates may include sand, pieces of gravel and stone of various size and shape, and recycled materials including concrete.
According to one embodiment of the present invention, a wall form 14 is initially constructed in accordance with the desired shape and size of the wall or outer structure. In the preferred embodiment of the invention, the wall form 14 is constructed out of plywood, however, other materials known by those skilled in the art may also be used. After the wall form is constructed, concrete 12 is poured into the wall form 14 . In order to enhance the strength of the ultimately formed wall or other structure, re-bar may be placed within the wall form 14 before the concrete 12 is poured therein.
Once the concrete 12 is poured into the wall form 14 , it is given a prescribed period of time to cure. During the curing process, the concrete 12 acquires a certain threshold of hardness and strength. Once the concrete 12 at least partially cures, the wall form 14 is removed, thereby exposing the exterior surfaces of the base structure (e.g., a wall, barrier, etc) formed as a result of the curing of the concrete 12 . Thereafter, the exposed surfaces of the base structure formed by the cured concrete 12 are subjected to a procedure which creates a roughened surface texture 16 thereon. The roughened surface texture 16 is created to provide a base for facilitating the adhesion of a finishing mixture 18 thereto, as will be described in more detail below. The roughened surface texture 16 may be created through the use of a number of different surface roughening agents or techniques. For example, the roughened surface texture 16 may be achieved through the use of a form retarder or a spray on retarder. A retarder is the substance that slows the hydration, or hardening, of the concrete 12 . The roughened surface texture 16 may alternatively be created by sandblasting, acid watching, or chemically etching the exposed surfaces of the base structure formed by the cured concrete 12 . Other techniques known by those of skill in the art may also use to facilitate the creation of the roughened surface texture 16 .
Subsequent to the creation of the roughened surface texture upon the base structure formed by the cured concrete 12 , the finishing mixture 18 described above is applied thereto. The finishing mixture 18 may be created by separating large aggregate 20 present in the concrete 12 from the remainder thereof. Such large aggregate 20 may include large pieces of gravel or crushed stone found in the original mixture of concrete 12 poured into the wall form 14 . It is contemplated that by removing the large aggregate 20 from the concrete 12 , the resultant finishing mixture 18 will have a more uniform texture.
In accordance with one embodiment of the present invention, it is contemplated that the finishing mixture 18 may be created from the same mix or batch of the concrete 12 originally poured into the wall form 14 . The use of such original batch may beneficially allow for color consistency between the base structure formed from the cured concrete 12 and the finishing mixture 18 subsequently applied to the exposed exterior surfaces of such base structure having the roughened surface texture 16 formed thereon in the above-described manner. In accordance with another embodiment of the present invention, the finishing mixture 18 may be created from a separate mix of the concrete 12 .
As indicated above, the finishing mixture 18 is applied to the roughened surface texture 16 of the base structure formed by the cured concrete 12 , with the cured finishing mixture 18 ultimately defining the uniformly textured exterior surfaces of a final concrete structure comprising a combination of the base structure and the hardened finishing mixture 18 . The finishing mixture 18 may be applied to the roughened surface texture 16 through the use of a float. In this regard, the finishing mixture 18 is worked into the roughened surface texture 16 until the desired finished surface texture is achieved. At this point, the finishing mixture 18 may be left alone to cure. However, it is contemplated that the finishing mixture 18 may be troweled before curing to achieve a harder texture. In addition, after the finishing mixture 18 fully cures/hardens, it may be acid washed to achieve certain textured features. An exemplary wall 10 formed in accordance with the aforementioned methodology and possessing the smooth, uniformly textured exterior surfaces features highlighted above is shown in FIG. 5 . However, as also indicated above, the methodology of the present invention may also be used to form a plurality of different structures other than the wall 10 shown in FIG. 5 .
The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.
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A method of forming a concrete wall having a substantially uniform exterior surface texture. The method includes the initial step of pouring concrete into a wall form. The concrete is poured from a first mixture and is allowed to cure. After the concrete is cured, the wall form is removed from the resultant concrete base structure. A roughened texture is then created on the base structure. A finishing mixture is then applied to the roughened texture. The finishing mixture may be created by separating the aggregate from a portion of the remaining first mixture. The finishing mixture creates a smooth texture on the exterior surfaces of the initially formed base structure.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for positioning glass sheets for forming.
2. Background Art
Glass sheets are conventionally formed by heating on a conveyor within a furnace and then forming prior to delivery for cooling. Such cooling can be slow cooling to provide annealing or faster cooling that provides heat strengthening or tempering. In connection with heating of the glass sheets, see U.S. Pat. Nos. 3,806,312 McMaster et al.; 3,947,242 McMaster et al.; 3,994,711 McMaster; 4,404,011 McMaster; and 4,512,460 McMaster. In connection with glass sheet forming, see U.S. Pat. Nos. 4,204,854 McMaster et al.; 4,222,763 McMaster; 4,282,026 McMaster et al.; 4,437,871 McMaster et al.; 4,575,390 McMaster; 4,661,141 Nitschke et al.; 4,662,925 Thimons et al.; 5,004,491 McMaster et al.; 5,330,550 Kuster et al.; 5,376,158 Shetterly et al.; 5,472,470 Kormanyos et al.; 5,900,034 Mumford et al.; 5,906,668 Mumford et al.; 5,925,162 Nitschke et al.; 6,032,491 Nitschke et al.; 6,173,587 Mumford et al.; 6,227,008 Shetterly; 6,418,754 Nitschke et al.; 6,543,255 Bennett et al.; 6,578,383 Bennett et al.; 6,718,798 Nitschke et al.; 6,729,160 Nitschke et al. In connection with the cooling, see U.S. Pat. Nos. 3,936,291 McMaster; 4,470,838 McMaster et al.; 4,525,193 McMaster et al.; 4,946,491 Barr; 5,385,786 Shetterly et al.; 5,917,107 Ducat et al.; 6,079,094 Ducat et al.; and 6,513,348 Bennett et al.
Vehicle windshields are conventionally manufactured from outer and inner formed glass sheets and an intermediate layer of polyvinyl butyral. The outer and inner glass sheets have different sizes since the outwardly curved shape of the formed windshield necessitates that the outer glass sheet be slightly greater in size than the inner glass sheet. Also, upon manufacturing, there can be slight variations in the size of flat glass prior to the forming. Thus, switches which have previously been utilized to sense the approach of a glass sheet to initiate transfer from a conveyor for forming do not necessarily initiate transfer that positions the glass centrally on a forming mold for the forming.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved method for positioning a heated glass sheet for forming.
In carrying out the above object, the method for positioning a heated glass sheet for forming is performed by conveying a heated glass sheet on a horizontal conveyor in a horizontally plane of conveyance along a direction of conveyance toward a forming station having a forming mold including a downwardly facing curved forming face that is positioned above the plane of conveyance and has a forming portion for forming a glass sheet of a predetermined size. The spacing along the direction of conveyance between downstream and upstream extremities of the conveyed glass sheet is detected to determine any difference from the glass sheet of the predetermined size and a control signal is generated to indicate any such difference. The conveyance of the glass sheet is continued below the forming mold and the control signal is used to centrally position the glass sheet along the direction of conveyance below the forming portion of the forming face. The centrally positioned glass sheet is transferred from the conveyor to the forming mold for forming of the glass sheet against the forming face.
The downstream extremity of the conveyed glass sheet is preferably initially detected by a detector and the upstream extremity of the conveyed glass sheet is subsequently detected by the detector in coordination with the conveyance to generate the control signal, and the conveyance of the glass sheet is coordinated with the control signal to provide the central positioning of the glass sheet along the direction of conveyance below the forming portion of the forming face. More specifically, the subsequent detection of the upstream extremity of the conveyed glass sheet generates the control signal which is coordinated with the conveyance to provide the central positioning of the glass sheet for the transfer from the conveyor to the mold forming face. Also, the conveyance of the glass sheet is decelerated upon approaching the central position below the mold forming face and is transferred to the forming face at the central position while still moving.
The glass sheet positioning method as disclosed is used to alternately convey and position vehicle windshield outer and inner glass sheets for the forming with the outer glass sheets having a slightly greater distance between their downstream and upstream extremities than the inner glass sheets.
Furthermore, the centrally positioned glass sheet is transferred from the conveyor to the forming mold by any step including: lifting the glass sheet upwardly from the conveyor by a continuous ring; lifting the glass sheet upwardly from the conveyor by a segmented ring; drawing a vacuum at the curved forming face of the forming mold; moving the forming mold downwardly toward the conveyor; blowing gas upwardly from below the glass sheet to lift the glass sheet upwardly from the conveyor; and any combination of two or more of these steps.
Also, the glass sheet is laterally located prior to heating and subsequent conveyance to the forming station.
The objects, features and advantages of the present invention are readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a glass sheet forming system that performs a method for positioning glass sheets in accordance with the invention.
FIGS. 2 a and 2 b illustrate a detector of a detection system for respectively detecting downstream and upstream extremities of a conveyed glass sheet in preparation for forming.
FIGS. 3 a and 3 b respectively illustrate the manner in which larger and smaller glass sheets are centrally positioned on a forming face of a curved forming mold to provide forming to a design shape.
FIG. 4 is a top plan view taken along the direction of line 4 - 4 in FIG. 1 to illustrate transfer apparatus embodied as a lifter including a continuous ring.
FIG. 5 is a view taken in the same direction as FIG. 4 illustrating another embodiment of the transfer apparatus lifter which is a segmented ring.
FIG. 6 is a partial side elevational view similar to FIG. 1 illustrating the system forming station wherein the transfer apparatus includes lift jets for blowing air upwardly from below the conveyor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 , a glass sheet forming system is generally indicated by 10 and includes a loading station 12 for loading glass sheets G, a furnace 14 for heating the glass sheets, a forming station 16 for forming the glass sheets, and a quench station 18 for cooling the glass sheets for slow cooling to provide annealing although it is also possible to provide faster cooling for tempering or heat strengthening when required by the application of the particular type of glass sheet being processed.
With continuing reference to FIG. 1 , a conveyor 20 of the forming system is illustrated as being of the roll type including rolls 22 that convey the glass sheets for heating in the furnace 24 and for movement into the forming station 26 for the forming. The conveyor rolls 22 support each glass sheet G in a horizontal plane of conveyance for movement along a direction of conveyance as shown by arrow C. It is also possible to convey the glass sheets on other types of conveyors, such as on air hearth conveyors in which case the horizontal plane of conveyance normally will be slightly tilted in a lateral direction transverse to the direction of conveyance.
At the loading station 12 each glass sheet is loaded either manually or by automated apparatus such as one or more robots for conveyance on the rolls 22 of conveyor 20 . A lateral positioner 24 of the loading station laterally positions each loaded glass sheet G with respect to the direction of conveyance so as to be in the proper location upon ultimately reaching the forming station 16 after passage through a heating chamber 26 of the furnace 14 for heating to a forming temperature in any conventional manner.
The forming station 16 as shown in FIG. 1 includes a housing 28 that defines a heating chamber 30 in which a forming mold 32 is located. This heated chamber 30 as disclosed is not as hot as the heating chamber 26 of furnace 14 , more specifically, the furnace heating chamber will normally be on the order of 600-680ยฐ C. in different locations, while the heating chamber 30 where the forming mold 32 is located will be about 500ยฐ C. The forming mold 32 is located above the rolls 22 of the conveyor 20 and has a downwardly oriented forming face 34 of a curved shape. This forming face has a forming portion for forming a glass sheet of a predetermined size. More specifically, as shown in FIGS. 3 a and 3 b , the forming portion of forming face 34 has a central location CL along the direction of conveyance C. A glass sheet of the predetermined size when centrally positioned on the conveyor, or on the forming face 34 as is hereinafter described, will have the midpoint between its downstream and upstream extremities along the direction of conveyance located at the forming face central location CL.
A controller 36 of the forming system through a connection 38 operates a schematically indicated drive 40 of the conveyor 20 . Furthermore, a detection system 42 of the system includes a detector 44 located upstream from the forming mold 32 and having a connection 46 to the controller 36 .
As shown in FIG. 2 a , the detector 44 propagates a detection beam 48 that initially detects a downstream extremity 50 of the conveyed glass sheet. Thereafter as shown in FIG. 2 b , the detector 44 detects an upstream extremity of the conveyed glass sheet such that the controller 36 can measure the spacing or distance between these upstream and downstream extremities and any difference either larger or smaller than the glass sheet of the predetermined size. Furthermore, the subsequent detection of the upstream extremity through the coordination of the controller 36 in driving the conveyor 20 provides an indiction of the location of the conveyed glass sheet so a control signal can be generated such that the glass sheet is moved to the central position below the forming face 34 of the forming mold 32 as shown by phantom line representation in FIGS. 3 a and 3 b . More specifically, each centrally positioned glass sheet G regardless of its spacing between its downstream and upstream extremities 50 and 52 will have the same distance downstream and upstream from the central location CL so that the forming of the glass sheet will be to the design shape despite any difference in the glass sheet sizes. It should be appreciated that other types of detectors can be used in addition to the beam propagating detector shown.
As illustrated in FIG. 1 , the forming station 16 includes transfer apparatus collectively indicated by 54 for performing upward transfer of the glass sheet from the central position on the conveyor 20 upwardly to the central position on the forming mold 32 as shown in FIGS. 3 a and 3 b and described above. Just prior to the conveyed glass sheet G reaching the central position on the conveyor 20 , the controller 36 shown in FIG. 1 slows the conveyor to decelerate the glass sheet. Upon reaching the central position shown in FIGS. 3 a and 3 b but before termination of the conveyance, the transfer apparatus 54 begins the upward transfer of the glass sheet to the forming face 34 of the forming mold 32 at the central position for the forming.
Transfer apparatus 54 as shown in FIG. 1 includes a lifter 56 that is moved vertically by an actuator 58 having a connection 60 to the controller 36 . This lifter 56 as illustrated in FIG. 4 may be a continuous ring 60 that moves upwardly from below disc shaped wheel rolls 22 in a manner more fully disclosed by U.S. Pat. No. 6,543,255, the entire disclosure of which is hereby incorporated by reference. In addition as shown in FIG. 5 , the lifter 56 may be embodied by a segmented ring 62 whose portion 64 move upwardly between elongated conveyor rolls 22 to provide the lifting.
With reference back to FIG. 1 , the transfer apparatus 54 as disclosed also includes a vacuum supply 66 that draws a vacuum through a conduit 68 at openings in the forming face 34 of the forming mold 32 under the operation through a connection 70 to the controller 36 . It should be noted that this vacuum supply 66 may have an initial greater vacuum that is provided by a vacuum impulse and subsequently is reduced to prevent deformation of the heated glass sheet at the forming face openings through which the vacuum is drawn. It is also possible to subsequently supply positive pressure air to the forming face openings to provide release of the glass sheet for delivery and subsequent cooling as is hereinafter more fully described.
The transfer apparatus 54 shown in FIG. 1 also includes a vertical control or actuator 72 having a connection 74 to the forming mold 32 to provide vertical movement thereof between the solid indicated upper position and the phantom line indicated lower position under the control of a connection 76 to the controller 36 .
As shown in FIG. 6 , the transfer apparatus 54 can also be constructed to include a gas supply 78 that feeds gas from a pressurized source 80 through a valve 82 operated by a connection 84 to the controller 36 to blow gas upwardly through an array 86 of lift jet nozzles 88 . More specifically, the upwardly blown air passes between the conveyor rolls 22 to actuate the lifting.
The forming system 10 has particular utility when utilized to manufacture vehicle windshields which include outer and inner glass sheets that are of a slightly different size than each other. More specifically, the curved shape of the formed windshield results in the outer glass sheets being slightly larger than the inner glass sheets. However, since the glass sheets are centrally positioned along the direction of conveyance shown by arrow C with respect to the center location CL, both the inner and outer glass sheets are formed at the same forming portion of the forming face 34 of the forming mold 32 so as not to have different curvatures than each other. During the manufacturing, the larger outer glass sheets and the smaller inner glass sheets are alternately loaded on the conveyor 20 at the locating station 12 and ultimately heated in the furnace and processed for forming at the forming station 16 as described above.
After each glass sheet is formed as illustrated in FIG. 1 , the cooling station 18 receives the formed glass sheet by a cooling mold 90 operated by delivery apparatus 92 having an actuator 94 from which a connection 96 extends to the mold and with a control connection 98 extending from the actuator to the controller 36 to provide the operation in coordination with the rest of the forming station.
It should be appreciated that the cooling station 18 can also be of the quenching station type for providing rapid cooling that tempers or heat strengthens the formed glass sheet in other applications.
While different modes of the invention have been illustrated and described, it is not intended that these modes illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
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A method having particular utility for making outer and inner formed windshield glass sheets is performed by glass sheet positioning centrally on a forming face ( 34 ) of a forming mold ( 32 ) to form each glass sheet to a design shape regardless of any size difference between the glass sheets from one cycle to the next.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority of the filing date of provisional application Ser. No. 61/355,598 filed Jun. 17, 2010.
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
FIELD OF THE INVENTION
This invention relates to hypergolic fuels, particularly those having components of little or no toxicity.
BACKGROUND OF THE INVENTION
The state-of-the-art, storable bipropulsion system uses a hydrazine (typically monomethylhydrazine) as a fuel component. This fuel affords useful performance characteristics and has a fast ignition with an oxidizer. Such fast (hypergolic) ignition provides system reliability for on-demand action of the propulsion system. In addition, a bipropellant's hypergolic character is very beneficial since it removes the requirement of a separate ignition component; additional components bring increased inert mass and reduced system performance. The energy density of the state-of-the-art, storable bipropulsion system is largely limited by the density of the fuel. Storable fuels range in density from 0.88 g/cc (monomethylhydrazine) to 1.00 g/cc (hydrazine). Energetic ionic liquids have established densities that range well above 1.00 g/cc, and thus can confer greater energy density as bipropellant fuels. Also, there are significant costs and operational constraints associated with handling state-of-the-art fuels (hydrazines) that derive from the fuel's carcinogenic vapor. Fuel transport, loading and unloading are significantly complicated by its vapor toxicity and can require considerable efforts and costs in vapor monitoring with trained operations crews employed in expensive personal protection equipment.
Accordingly there is need and market for environmentally enhanced โgreenโ fuels, which overcome the above prior art shortcomings.
SUMMARY OF THE INVENTION
Broadly, the present invention provides a bipropellant having, an ionic liquid (IL) containing a metalohydride as fuel and an oxidizer, which fuel and oxidizer have hypergolic ignition upon contact.
In one embodiment, the above IL has an anion and cation, with the metalohydride being situated in the anion.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the present invention in detail, advanced IL fuels with fast ignition (upon mixing with storable oxidizer), have been synthesized per the invention. Principally, such fuels are based upon ionic liquids containing borohydride including anions with borohydride as a structural component or other metallohydrides. That is, borohydrides and substituted borohydride anions of the formula:
where R is as noted below.
The borohydride anions of the present invention include unsubstituted BH 4 -and mono-, di-, tri-and tetra-substituted borohydride anions in which the substituted, R-groups can be nitriles, alkyls, or ethers or a combination thereof. Also, stable polyborohydrides such as octahydrotriborate can be utilized.
Further suitable metalohydride anions have the formula:
where R is as noted below.
The metalohydride anion structures shown above include hydrides containing both aluminum and boron. Additionally, unsubstituted and mono-, di-,tri- and tetra-substituted aluminum hydrides are employable in which the substituted, R-groups can be nitriles, alkyls or ethers or a combination thereof.
In addition to the anion, the ionic liquid must contain a cation with a structure that resists reduction by the anion. Stability dictates the cation should not be the protonated form of a free base, and greater stability is found with cations that are free of carbonyl and functionalities containing the iminium group. Thus, cations can be selected from open chain substituted ammonium, substituted pyrrolidinium, piperidinium, tetrazolium or imidazolium groups as shown in the formulas below:
where R 1 , R 2 , R 3 , R 4 can be equivalent or different in structure and are selected from hydrogen, cyano-, alkyl substituted amino, azido, hydroxyl, halide, C 1 โC 18 hydrocarbon chains, or C 1 โC 18 hydrocarbon chains containing cyano-, alkyl substituted amino, azide, hydroxyl, halide, nitrato-, nitro-, nitramino-, amido-,amidino-, hydrazino- chemical functionalities.
The determination of reactivity of borohydride-based ionic liquids with white fuming nitric acid (WFNA), nitrogen tetroxide and hydrogen peroxide (both 90% and 97%) was performed. The experimental results are shown in the table below. Fast ignition is generally observed with these ionic liquid fuels upon contact with the liquid oxidizer.
TABLE 1
IGNITION RESPONSE OF IONIC
LIQUID-BASED FUELS WITH WHITE FUMING NITRIC
ACID, NITROGEN TETROXIDE AND HYDROGEN PEROXIDE
compound
WFNA
N2O4
H2O2
Ignition
Ignition
Ignition (90% H 2 O 2 )
BMIM BH4
Ignition
Ignition
Ignition
(90% H 2 O 2 )
75% BMIM BH4
Ignition
Ignition
Ignition
25% EMIM B(CN)4
(97% H 2 O 2 )
Mixture
(in propylamine)
TBD
TBD
Ignition (97% H 2 O 2 )
TBD
TBD
Ignition (97% H 2 O 2 )
Ignition
Ignition (on 2 nd drop)
No Ignition (97% H 2 O 2 )
In the preferred embodiment of the invention, both the cation and anion structures are chosen to confer low melting points and low viscosity, while also incorporating structures that increase heat of combustion of the fuel with the storable liquid oxidizer. Such substituent (i.e., R-group) structures may be strained-ring (e.g., cyclopropyl-), or high-nitrogen moieties (e.g., azido-or cyano).
Ionic liquids have established characteristics of negligible vapor toxicity and generally higher density than typical propulsion fuels (e.g., hydrocarbons and hydrazines). The design and development of energy-dense, fast-igniting ionic liquids as fuels for bipropellants can provide improved handling characteristics (due to lower toxicity hazard) and thus lower operations cost. In addition, such fuels can impart greater performance capabilities such as increased velocity, range or system lifetime.
Advanced bipropellant fuels are designed for fast ignition, upon mixing
with storable oxidizer (N 2 O 4 , nitric acid and hydrogen peroxide) and have been synthesized per the invention. The bipropellant fuels are based upon salts, particularly ionic liquids, containing borohydride-based anions and employ cations designed to impart low melting point, stable molecules.
Fast igniting, ionic liquid fuels provide a means to overcome significant limitations of a state-of-the-art, storable bipropulsion system. Such ionic liquid fuels can provide greater than 20% improvement in density over hydrazine fuels. This confers greater energy density to the bipropulsion system. Also, the negligible vapor pressure of ionic liquid fuel provides an outstanding means of significantly reducing costs and operational constraints associated with handling the fuel. Prior to this invention, fast-igniting ionic liquid fuels were limited to operation with oxidizers based solely on oxides of nitrogen (e.g., NTO/WFNA/RFNA/IRFNA) as the only suitable oxidizers. The discovery of hypergolic activity of metalohydride-based ILs in combination with stabilizing cations, affords a new class of IL-based fuel that provides fast ignition with not only oxides of nitrogen but also with hydrogen peroxide. The employment of a fast-igniting ionic liquid fuel with hydrogen peroxide oxidizer, provides an avenue toward a bipropulsion system that employs environmentally enhanced (or green) fuel and oxidizer.
The preferred embodiment of the invention is the employment of pure borohydride-based IL fuel as a fast-igniting, bipropellant. However, the use of these ionic liquid molecules as components in fuel mixtures to confer fast-ignition and density, is also a viable mode of the invention.
A hypergolic bipropellant based upon an ionic liquid, borohydride-based fuel and an oxidizer (H 2 O 2 /NTO/WFNA/RFNA/IRFNA) has potential as a replacement for bipropellants currently used in on-orbit spacecraft propulsion. Other application areas include liquid engines for boost and divert propulsion. The high energy density that is inherent in the new hypergol, lends itself to applications that require high performance from volume limited systems. The low vapor toxicity of the ionic liquid fuel is a benefit over toxic hydrazine fuels currently used.
Also, the performance aspects of this new hypergol can find use in commercial applications in satellite deployment and commercial space launch activities.
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Provided is an ionic liquid (IL) having anions and cations with a metalohydride in the IL of borohydrides and/or aluminum hydrides, as fuel and a choice of one or more oxidizers, which fuel and oxidizer have hypergolic tendencies.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of our application Ser. No. 709,677 filed July 29, 1976 now U.S. Pat. No. 4,111,877.
Aqueous emulsions containing compounds of the present inventions and coating compositions formed therewith are claimed in companion application having U.S. Ser. No. 873,813 now U.S. Pat. No. 4,151,142, and entitled "Wet Adhesion Emulsions for Paints and Coating Compositions."
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to generally polymerizable monomeric compounds containing a terminal ureido group. More particularly, the invention is concerned with novel compounds having at one end thereof a cyclic or acyclic ureido group and at the other end a vinyl group, the terminal groups being connected through a selected linking structure as hereinafter described. The novel compounds of the invention can be designated by the general structural formula: ##STR3## wherein R is H or CH 3 , U designates a cyclic or acyclic ureido or thioureido group and L designates the linking structure, as hereinafter described.
2. Prior Art
There are disclosed in the prior art various monomeric compounds containing a ureido group at one end and an unsaturated ethylenic group at or near the opposite end, which unsaturated group may be the residue of an unsaturated mono- or di-carboxylic acid. Thus, the U.S. Pat. Nos. 2,881,155 and 2,881,171, there are described monomeric polymerizable compounds containing at one end a cyclic ureido group, and at the other end an acrylic or methacrylic acid radical linked through an alkyl amido group. These compounds correspond to the general structural formula ##STR4## wherein R is H or CH 3 and A is an alkylene group having 2 or 3 carbon atoms.
Compounds of this type are prepared, for example, by condensing N-ฮฒ- aminoethyl-N-N'-ethyleneurea with an ester of an alpha haloacetic acid and then reacting the obtained intermediate with a salt of acrylic or methacrylic acid. The obtained compounds are capable of undergoing addition polymerization and condensation reactions.
Another type of compound containing a cyclic ureido structure at one end and at the other end the residue of an unsaturated dicarboxylic acid is described in U.S. Pat. No. 2,980,652; such compounds correspond generally to the formula: ##STR5##
Compounds of this type are also stated to be susceptible to both addition polymerization, by virtue of their unsaturation, and to condensation reactions by virtue of the heterocyclic nitrogenous rings.
Instead of condensing the N-aminoalkyl urea with an unsaturated dicarboxylic acid, a monocarboxylic acid, such as crotonic acid, is employed in U.S. Pat. No. 3,369,008 forming compounds of the general formula ##STR6##
By reacting the anhydride of a dicarboxylic acid with the N-hydroxyalkyl derivative of a cyclic urea, ester compounds are formed according to U.S. Pat. No. 3,194,792. These compounds correspond generally to the formula ##STR7## (m=zero to 9) Z=C 2 to C 8 alkylene group
R o =C 2 to C 3 alkylene group
The foregoing types of compounds are stated to be useful for one or more of the following purposes: as plasticizers for vinyl and acrylic resins and as anti-static agents; they may be reacted to form copolymers and interpolymers with monoethylenically unsaturated compounds, useful as warp sizes and for improving wet strength of paper; such copolymers also provide valuable coating compositions and bases for water-base paints, as well as binders for non-woven fabrics among other noted uses. Other suggested uses for certain of these compounds include the formation with various resin components of polymeric compositions having improved adhesion properties when employed in paints and coating compositions, particularly as applied to metals, glass and plastics.
A wide variety of monomers containing a ureido group of straight chain or cyclic type are disclosed in U.S. Pat. No. 3,300,429, including certain of those hereintofore described. According to that patent, improved coating and impregnating compositions are formed by admixing certain water insoluble addition polymers (1), such as vinyl ester or acrylic polymers, with a low molecular weight soluble ammonium salt of certain copolymers of ethylenically unsaturated carboxylic acids (2), and with a specified surfactant; when at least one of the components (1) or (2) comprises polymerized monomer units containing a ureido group. These coating compositions in the form of aqueous polymer dispersions and water base paints are stated to possess improved adhesion and penetration properties such as in their application to porous substrates including wool, textiles and non-woven fabrics as well as in their application to powdery or chalky surfaces.
In our copending patent application Ser. No. 709,677 filed July 29, 1976, there are described novel cyclic ureido monomers terminating at the opposite end in the residue of an allyl or methallyl ester as in ##STR8##
The compounds of said copending application, in contrast to the known cyclic ureido derivatives of the prior art, are characterized in that the carbonyl group in the chain linking the amino nitrogen of the N-aminoalkyl urea to the terminal ethylene group, is not directly attached to an ethylenic carbon atom.
In copending U.S. patent application Ser. No. 709,916 filed July 29, 1976, the synthesis of novel allyl succinamic ureido compounds is described. These compounds as well as those described in the companion copending application Ser. No. 709,677, are shown to be particularly useful as functional comonomers for imparting improved wet adhesion properties to emulsion systems containing vinyl ester polymers employed in paints and coating compositions. Other suggested uses for the described monomers of the aforesaid copending patent applications include: their use as such or as intermediates in resin modifiers, and as plasticizers, textile sizes, textile softeners, antistatic agents and wet strength paper resins.
SUMMARY OF THE INVENTION
Among the objects of the present invention is to extend the variety and compass of ureido monomers useful for the various purposes hereinbefore described, by providing additional novel compounds and methods for their synthesis.
The novel compounds of the present invention correspond to the general formula ##STR9## wherein R is H or CH 3 , U designates a cyclic or acyclic ureido or thioureido group and L designates a selected linking chain connecting a ureido nitrogen to the olefinic carbon of the (--C=CH 2 ) terminal group at the opposite end of the chain. The linking chain L, for example, may contain one or more oxy (ether), amino, amido or carbonyl groups, provided that any carbonyl group (CO) present is not directly attached to U or to an ethylenic carbon atom nor is an ethylenic carbon directly attached to a nitrogen atom. The ureido terminal group --U-- may be acyclic, corresponding to the structure ##STR10## in which B is an oxygen or sulfur atom, and R 1 , R 2 and R 3 each separately is hydrogen, alkyl, aryl, hydroxyalkyl or alkoxy alkyl, or R 2 and R 3 may form a cyclic structure by being part of a piperidine, pyrrolidine or morpholine structure; or the ureido group may be cyclic, corresponding to the structure ##STR11## wherein B is an oxygen or sulfur atom, R 4 is hydrogen, alkyl, aryl, hydroxyalkyl or alkoxyalkyl; and A is an alkylene group of 2 to 3 carbon atoms, such as
--CH.sub.2 --CH.sub.2 --, --CH.sub.2 --CH.sub.2 --CH.sub.2,
or
--H.sub.2 C--CH(CH.sub.3)--.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrative examples among the types of linking structures L comprised in the novel compounds of the invention corresponding to formula I above, include the following: ##STR12## wherein R, R 1 , A and U are as defined above, T is oxygen or ##STR13## and n is an integer from 1 to 9. L in this compound then is --(CH 2 ) n --T--A--. A specific example of such compound is represented by the formula ##STR14## A further group of compounds are those represented by the general formula ##STR15## wherein G is CH 2 NR 1 or CH 2 , T is oxygen or NR 1 and the other symbols are as above defined. In this example L is ##STR16## Specific examples of such compounds are those corresponding to the formulae ##STR17## A further type of useful compounds is represented by the general formula ##STR18## wherein D is (CH 2 ) n or CH 2 --T--(CH 2 ) n --. In this group L is ##STR19## Particular examples of such compounds include those represented by the formulae ##STR20## A further group of useful compounds is represented by the general formula ##STR21## wherein E represents an alkylene group of 1 to 10 carbon atoms and J is CH 2 O--, CH 2 NR 1 --, or an oxygen atom. In this example, L is ##STR22## Illustrative examples of such compounds include those represented by the formulae ##STR23## Another group of useful compounds is that represented by the general formula ##STR24## In this class of compounds, L is ##STR25## Illustrative examples of such compounds are: ##STR26## A further group of such compounds is that represented by the general formula ##STR27## In this group L is ##STR28## A specific example of compounds coming within this group is that represented by the formula: ##STR29##
SYNTHESIS OF HCl SALT OF N-ฮฒ-(ALLYLAMINO) ETHYL ETHYLENEUREA (FORMULA VIIa)
To a reaction vessel containing 285.5 parts by weight of allylamine, there were added 148.04 parts of N-(ฮฒ-chloroethyl)-N,N 1 -ethyleneurea and 750 parts distilled water. A slight exotherm was observed (temperature rise about 16ยฐ C.).
Heating was commended with stirring, and an initial reflux temperature of 87.5ยฐ C. was observed. The reactants were permitted to reflux overnight, after which the contents were transferred to a concentrating vessel and heated at about 75ยฐ C. to remove water and excess allyl amine.
A mass of yellow waxy material was obtained. This product was taken up in absolute ethanol (350 parts product per 237 parts alcohol) and to the resulting hot mixture there was added 630 parts by weight of ethyl acetate and the mixture set aside to cool slowly. Crystals of the hydrochloride salt of compound VIIA were filtered off from the cooled mixture and dried in a vacuum oven at room temperature.
Actual yield obtained was 85.11% of theory. The crystalline product had a melting point of 151.5ยฐ-152.5ยฐ C.
______________________________________ELEMENTAL ANALYSIS C H N______________________________________Actual % 45.95 7.99 19.94Theor. % 46.74 7.78 20.44______________________________________
Instead of reacting the chloroethyl urea compound with the allylamine, the same product can be obtained by reacting the 2-aminoethyl ethyleneurea with allyl halide. If one employs as reactant with the ureido amine, the isomeric 1-halo-2-methyl-2-propene compound, corresponding compounds are obtained terminating in the ##STR30##
PREPARATION OF ALLYL(B-1-ETHYLENEUREIDO) ETHYL CARBONATE (FORMULA VIIIb)
In a reaction vessel there were mixed
______________________________________ parts by weight (pbw)______________________________________N-ฮฒ-(hydroxyethyl)-N,N.sup.1 -ethyleneurea 130Methylene chloride 1325.5Triethylamine 126.31______________________________________
To the resulting mixture there was added dropwise 150.6 parts allyl chloroformate while maintaining the temperature at 10ยฐ-15ยฐ C. The addition took about 1.5 hours.
The mixture began to reflux at about 45ยฐ C., and was continued overnight. It was then filtered with suction and the filtrate containing the product was concentrated under vacuum. The last traces of solvent were removed by vacuum pumping overnight with heating to 50ยฐ C. Actual yield was 88.7% of theory.
______________________________________ELEMENTAL ANALYSIS C H N______________________________________% theory 50.49 7.51 13.08% actual 51.54 6.53 12.63______________________________________
SYNTHESIS OF N-(ฮฒ-1-ETHYLENEUREIDO) ETHYL ALLYLOXYACETAMIDE (FORMULA IXc)
The reactants comprised:
______________________________________ parts by weight (pbw)______________________________________N-(ฮฒ-aminoethyl)-N,N'-ethyleneurea 71Allyl allyloxyacetate 86.23Acetonitrile 157.14______________________________________
These were added one after another to a reaction vessel and the mixture stirred for about 2 hours at room temperature. A TLC (thin layer chromotography) plate was run on the mixture which indicated that some product was formed.
The reaction was maintained at 50ยฐ for about 17 hours. The TLC plate was again run on the mixture which indicated further product formation.
The product was heated for an additional three hours, then cooled and filtered to remove the precipitated impurities. The filtrate was stripped of acetonitrile and allyl alcohol by rotary evaporation. A clear yellow oil remained which solidified on standing at room temperature. The obtained solid material was recrystallized from ethanol/ethyl ether and had a melting point of 73ยฐ-74ยฐ C. The actual yield was 45.16% of theory.
PRODUCTION OF ALLYL N-METHYL-N-ฮฒ-(1-ETHYLENEUREIDO) ETHYL CARBAMATE (FORMULA VIIIc)
In a reaction vessel there were mixed
______________________________________ parts by weight (pbw)______________________________________N-(ฮฒ-Methylaminoethyl)-N,N'-ethyleneurea 18Methylene chloride 99.4Sodium hydroxide (30% aqueous solution) 143.______________________________________
and the mixture stirred until a clear solution was obtained. To this solution there was added dropwise with cooling 12 parts of allyl chloroformate, keeping the temperature between 15ยฐ-20ยฐ C.
The reaction mixture was then stirred at room temperature for about an hour and let stand to permit the product to separate into layers. The bottom layer comprising the methylene chloride solution was dried over anhydrous magnesium sulfate. Following filtration to remove the magnesium sulfate, the methylene chloride solvent was stripped off at about 30ยฐ C. under vacuum. The product was obtained at 87.27% of theoretical yield.
It was confirmed by TLC that there was only one component in the reaction product and the structure was confirmed by NMR (nuclear magnetic resonance spectroscopy).
______________________________________ELEMENTAL ANALYSIS C H N______________________________________Theoretical % 52.88 7.48 18.5Actual % 51.61 7.78 18.14______________________________________
The compounds of the invention may be incorporated in emulsion systems containing acrylic, vinyl ester or other pigmented or non-pigmented aqueous emulsion systems useful in paints and coatings in the manner described in the aforesaid copending applications.
EXAMPLE 1
The following specific example illustrates the polymerization of the ureido compound of the type described within a commercial interpolymer system comprising vinyl acetate, vinyl chloride, ethylene and maleic acid.
To a pressure vessel, one charges:
______________________________________ parts by weight (pbw)______________________________________ Vinyl acetate 4540(a) Triton X-301 (20%) 1040(b) Igepal CO-730 416(c) Siponate DS-10 208 Sodium vinyl sulfonate (25%) 98 Potassium persulfate 300 Ferrous salt 1.5 Water 8170______________________________________ (a) Anionic surfactant; sodium salt of an alkaryl polyether sulfate. (b) Nonionic surfactant; nonylphenoxypoly (ethyleneoxy) ethanol comprisin 75% ethylene oxide. (c) Anionic surfactant; purified dodecyl benzene sodium sulfonate.
The agitated vessel contents initially show a pH of 3.2.
The kettle contents are purged with N 2 and agitated at 150 rpm. Upon heating to 46ยฐ C., the charge is pressurized to 900 psi (63.28 kg/cm 2 ) with ethylene. Polymerization then is initiated with a 2.0% Discolite solution and followed by simultaneous addition to the kettle of the following compositions in 5 delays.
In the first delay, the initiator is introduced over a period of eight hours and is composed of:
______________________________________ Delay 1 pbw______________________________________(d) Discolite 200 water 4600 NH.sub.4 OH (28%) 200______________________________________ (d) Sodium formaldehyde sulfoxylate.
The second and third delays are introduced during a three hour period. These comprise:
______________________________________Delay 2 Delay 3______________________________________4540 parts vinyl 9090 parts vinylacetate chloride______________________________________
The fourth and fifth delays are introduced during a four hour period. These comprise:
______________________________________Delay 4 pbw Delay 5 pbw______________________________________Maleic acid (29% sol) 664 ureido cmpd. VIIIc 363sodium vinyl sulfonate 293 water 1816water 2227______________________________________
The polymerization temperature is maintained at 50ยฐ C. with a jacket temperature of 23ยฐ-50ยฐ C. The kettle pressure is maintained at about 960 psi (67.5 kg/cm 2 ) throughout the delays. At the end of the delays, the vinyl acetate free monomer content generally is less than 0.5% and the final emulsion has a solids content of 53.4%. The final pH is adjusted to 5.0.
EXAMPLE 2
An example for preparation of another emulsion system comprising a copolymer of vinyl acetate with ethylene and maleic acid is as follows.
There is charged to a pressure vessel
______________________________________ parts by weight (pbw)______________________________________ Vinyl acetate 1,907(e) Igepal CO 887 1,218(f) Igepal CO 630 426 Sodium vinyl sulfonate (25%) 158 Polysodium vinyl sulfonate (25%) 171 Potassium persulfate 80 Fe .sup.++ 0.3 Water 18,160______________________________________ (e) Nonyl phenoxypoly (ethyleneoxy) ethanol comprising 86% ethylene oxide (f) Nonyl phenoxypoly (ethyleneoxy) ethanol comprising 65% ethylene oxide
The stirred mixture has an initial pH of about 3.2.
The kettle contents are stirred at 150 rpm, purged with nitrogen, and then pressurized to 570 psi (=40 kg/cm 2 ) while heating to 50ยฐ C. Polymerization is initiated with a 50% solution of Discolite and added to the kettle simultaneously over a four hour period, are four delays as follows:
______________________________________ pbw pbw______________________________________Delay 1 Delay 2Vinyl acetate 19,749 Maleic anhyd. 115Triallyl cyanurate 8,898 Sodium vinyl sulfonate 173 (25%) Pot. persulfate 58 Water 922Delay 3 Delay 4Discolite 250 Ureido compound VIIIc 363NH.sub.4 OH (28%) 150 Water 4631Water 5,000______________________________________
The polymerization temperature is maintained at 50ยฐ C. with a jacket temperature of 43ยฐ C. and ethylene pressure of 570 psi (=30 kg/cm 2 ) during the course of the delays. At the end of the delays, and when the vinyl acetate free monomer content is less than 0.5%, the emulsion is cooled to ambient temperature and transferred to a degasser. The emulsion contains 50% solids.
EXAMPLE 3
A further example of an emulsion system comprising a copolymer of vinyl acetate and butyl acrylate made up for a semigloss paint which shows particularly good wet adhesion properties with addition of selected ureido compounds, is formulated as follows:
Into a jacketed reaction vessel there is charged
______________________________________ pbw______________________________________Hydroxyethyl cellulose 0.45Alkyl phenoxy poly (oxyethylene) ethanols 13.7Ferrous salt (trace)De-ionized water 380______________________________________
The vessel and contents are purged with nitrogen while heated to 65ยฐ C. and stirred. Then, there are added to the vessel at delayed intervals the three following mixtures
______________________________________Mixture 1 pbw______________________________________Vinyl acetate 415.2Butyl acrylate 67.5*Pluronics 15.6t-Butyl peroxide (70%) 0.7______________________________________Mixture 2 pbw______________________________________Sodium formaldehyde bisulfite 0.2Sodium benzoate 0.6De-ionized water 8.2______________________________________Mixture 3 pbw______________________________________Ureido compound VIIa 2.4De-ionized water 72.0______________________________________ *Pluronics are nonionic block polymers comprising polyalkylene derivative of propylene glycol terminating in hydroxyl.
The first and third mixtures are added over a two hour period while the second is added during a fifteen minute period. The polymerization mixture is maintained at 65ยฐ C. After addition of the second mixture is completed, there is further added a solution of 0.6 parts of sodium formaldehyde bisulfite in 18.1 parts de-ionized water until polymerization is completed. The emulsion then is cooled to ambient temperature. It has a pH of about 5.2 and contains about 55.4% solids. Addition of a pigment dispersion to the emulsion provides a semigloss paint with outstanding wet adhesion.
EXAMPLE 4
An example of an all acrylic emulsion to which improved wet adhesion properties is conferred by incorporation of the selected ureido compounds is formulated as follows.
To a reaction vessel there is added:
______________________________________ pbw______________________________________Igepal CO 887 61Igepal CO 630 31.3Fe .sup.++ traceWater 935.8______________________________________
The contents of the vessel are stirred at 120 rpm and heated to 65ยฐ C. under a nitrogen purge. Then there are added to the reaction vessel over a two hour period, three delays, as follows:
______________________________________ pbw______________________________________Delay 1Ethyl acrylate 480Methyl Methacrylate 320t-butyl hydroperoxide (70%) 1.4Delay 2Sodium formaldehyde sulfoxylate 1.5Sodium benzoate 1.1Deionized water 48.5Delay 3Ureido compound VIIa 8.0Deionized water 92______________________________________
The polymerization temperature is maintained at 65ยฐ-66ยฐ C. with a cooling jacket temperature of 60ยฐ C. At the end of the delays, and when there is no visible reaction exotherm, there is added to the emulsion 2.0 parts of sodium formaldehyde sulfoxylate and 1 part of t-butyl hydroperoxide (70%) mixed with 10 parts water. The obtained emulsion has about 44.4% solids and a pH of about 5.1.
The foregoing emulsion when put into a standard semigloss paint formulation, passes the cut film wet adhesion test described below.
The cut film test employed is a standard procedure for testing wet adhesion to a surface of semi-gloss paint as set out in Federal Specification TT-P-001511, paragraph 4.3.9 (GSA-FSS). In this test a panel is painted with an alkyd enamel of specified composition and permitted to dry under specified conditions. The test paint is then applied over the alkyd surface and dried. A cut is then made longitudinally through the center of the test film and the panel scrubbed under water at a specified rate of brush travel. To pass this test, there must be no loss of adhesion between the test paint and the alkyd undercoat and no wearing through to the undercoat in fewer than 5,000 cycles.
In the recut test, a second cut is made perpendicular to the first on the test film. To pass this test it is required that there be no adhesion failure between the test paint and the alkyd undercoat in fewer than 1000 cycles of under water brushing.
In the "floating board" test, the composition to be tested is applied over a dry glossy alkyd-painted plane board surface and dried. A one-inch section of the surface is scored by cross-hatching with parallel cuts vertical and horizontal 1/10-1/8 inch apart. An adhesive tape is applied to the dry scored surface and the relative amounts of the surface film peeled off by the adhesive observed. The board is again similarly scored and then floated face down on a water bath to wet the scored surface and the adhesive tape procedure repeated, again observing the amount of painted surface removed.
A representative number of ureido compounds were each incorporated into an emulsion system for testing of wet adhesion properties. The systems tested contained 0.75% of the ureido compound. Other amido compounds were also included in these tests as well as a control free of additive.
The results of the tests are shown in Tables 1 and 2 below, respectively, on the cut film and floating board tests.
The emulsion systems employed in all of the tests reported in Tables 1 and 2 were similarly prepared except for the particular ureido or amido compound employed to determine its properties for conferring improved wet adhesion to the paint composition into which the emulsion was incorporated.
The emulsion systems were prepared by mixing in a reaction vessel, a seed emulsion composed of:
______________________________________ pbw______________________________________(g) FLEXBOND 325 (55% solids) 91. Natrosal 25.0 LR (hydroxyethyl 0.89 cellulose) Fe.sup.++ trace Deionized water 539______________________________________ (g) A copolymer emulsion prepared from 86 parts vinyl acetate, 14 parts butyl acrylate, stabilized with hydroxyethyl cellulose. FLEXBOND is a registered trademark of Air Products and Chemicals, Inc.
The reactants were agitated at 200 RPM and heated to 65ยฐ C. while purging with nitrogen. There were simultaneously delayed to the emulsion seed over a 2 hour period, the following:
______________________________________ pbw______________________________________Vinyl acetate 868.n-Butyl acrylate 97.Igepal CO 887 15.Igepal CO 630 10.5Pluronic F 68 15.5Pluronic L 64 15.5t-Butyl hydroperoxide (70%) 1.4Followed by a solution composedof Ureido or amide compound 0.75% by weightbeing tested of monomersDeionized water 200 parts______________________________________
The polymerization temperature was maintained at 65ยฐ C. using an activator solution consisting of
______________________________________ pbw______________________________________Discolite PEA 0.4Sodium benzoate 1.1Deionized water 16.4______________________________________
The vinyl acetate free monomer content was kept between 3-5% throughout the polymerization with a jacket temperature between 53ยฐ-65ยฐ C. At the end of the delays, and when the vinyl acetate-free monomer content was below 0.5%, the emulsion was cooled. The final pH was 5.1 and solids content were 55.6%.
TABLE 1______________________________________ Cut Film 1st cut RecutTest Compound 5,000 cycles 1,000 cycles______________________________________N-allyl urea Pass PassAllyl carbamate Fails after 250 Fails at 340ฮฒ-Allyloxy propionamide Fails at 100 Fails at 239Compound of Formula VIIIc Pass PassCompound of Formula VIIIb Fails PassN-carbamyl maleamic acid Fails --Compound of Formula VIIa Pass PassCompound of Formula IXc Pass Pass3-buteneamide Fails --N-carboallyloxy urea Fails --N-carboallyloxy ethyleneurea Fails --N-(allyloxyacetyl) ethyleneurea Fails --Control Fails at 100 Fails at 100______________________________________
TABLE 2______________________________________ FLOATING BOARD % Removal to green paintTest Compound Wet Dry______________________________________N-allyl urea 0 0Allyl carbamate 26 4ฮฒ-Allyloxy propionamide 98 0Compound of Formula VIIIc 1 0Compound of Formula VIIIb 98 7N-carbamyl maleamic acid 82 1Compound of Formula VIIa 8 10Compound of Formula IXc 16 43-buteneamide 5 1______________________________________
While the compound of Formula VIIIb failed to pass the 5000 cycle wet adhesion test, it did pass the 1000 cycle recut test, and therefore showed significant improvement over the control which failed both of these tests.
The novel ureido monomers of the invention can be incorporated into aqueous paint or coating formulations by interpolymerization in emulsions comprising acrylates or methacrylates, or in emulsions comprising vinyl ester systems which may contain one or more other unsaturated monomers. Thus, such systems may comprise vinyl acetate alone or in admixture with one or more monomers from among ethylene, vinyl chloride, maleic acid, and alkyl esters of acrylic, methacrylic and maleic acids. Such emulsion systems generally comprise, in addition to the polymerizable monomer or monomers free radical initiators and emulsifying, stabilizing, and surface active agents. Preferably, the activator comprises a redox system, typically made up of a peroxide or persulfate catalyst and a reducing component, such as an alkali metal formaldehyde bisulfite or sulfoxylate. The principal emulsifying agent is preferably one of the nonionic type and may also include surface active agents of the anionic type.
The novel ureido compounds of the invention, added to water-based flat exterior paints also impart improved resistance to blistering.
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Polymerizable monomeric compounds corresponding to the general formula ##STR1## wherein R is H or CH 3 , U designates a cyclic or acyclic ureido or thioureido group and L designates a selected linking structure. The linking structure L may contain one or more oxy (ether), amino, amido, or carbonyl groups provided that any carbonyl group (CO) present is not directly attached to U or to an ethylenic carbon atom nor is such ethylenic carbon atom directly attached to a nitrogen atom. Representative examples include compounds corresponding to the formulae: ##STR2##
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Provisional Application No. 60/302,109, filed Jun. 28, 2001, which is incorporated herein by reference.
ACKNOWLEDGMENT OF FEDERAL RESEARCH SUPPORT
[0002] This invention was made, at least in part, with funding from the National Institutes of Health (NIH grant AI43346-01). Accordingly, the United States Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
[0003] The field of the present invention is the area of methods of formulating pharmaceutical compositions for medical and/or veterinary use, in particular, methods of formulating relatively insoluble or toxic materials such as polyene antibiotics, e.g., amphotericin B and nystatin, so that solubility in aqueous milieus is improved and so that toxicity is reduced, release is controlled and in at least some instances, the stability of the formulation is improved. Similarly, solubility is increased and toxicity is decreased for such cancer therapeutic agents as paclitaxel and tamoxifen.
[0004] Fungal infections are, in part, associated with immune-compromised patients such as those infected with HIV, patients who have been subjected to anticancer therapeutics or immune suppressive drugs after organ transplants, and the elderly. Fungal infections fall into two categories: systemic (deep) mycoses and superficial mycoses which involve the skin or mucous membranes. The dermatophytic fungi infect the skin, hair and nails; etiological agents include Epidermiphyton spp., Trichophyton spp. and Microspermum spp. Generally, infections of the mucous membranes are due to infections with Candida albicans . The systemic mycoses are serious and often life-threatening. They include cryptococcosis, systemic candidiasis, aspergillosis, blastomycosis, histoplasmosis, coccidiodomycosis, paracoccidioidomycosis, phycomycosis, torulopsosis, among others.
[0005] The three families of drugs used to treat fungal infections are the polyenes, imidazoles and antimetabolites. The polyenes include nystatin, which is generally used for superficial infections only, and amphotericin B. Mepartricin and natrimycin are other polyenes with antifungal activities.
[0006] Ketoconazole, miconazole and thiabendazole are imidazoles with antifungal activity. They act by inhibiting cytochrome activity and by interfering with ergosterol synthesis. Flucytosine is an antimetabolite which has been used in the treatment of systemic mycoses. It is converted in vivo to 5-fluorouracil, which inhibits thymidylate synthetase.
[0007] Amphotericin B (AmB) has an affinity for membranes with a relatively high ergosterol content; it forms channels which allow the passage of potassium and other small molecules. Because the AmB is very toxic, especially in aggregates, and has numerous side effects, it must be given in a hospital setting, adding to treatment costs. There is some evidence (Beringue et al. (1999) J. Gen. Virol. 80, 1873-1877; Beringue et al. (2000) J. Virol 74, 5432-5440) that certain polyenes may inhibit the progression of scrapie infections.
[0008] Despite its low solubility in water and the toxicity problems, AmB is one of the drugs of choice for treating fungal infections. Notably, the development of resistance to AmB is very rare. Numerous strategies have been employed to improve its solubility in aqueous systems and to reduce its toxicity. Strategies for the improvement of solubility and toxicity have included formulation with surfactant, e.g. deoxycholate, liposome encapsulation, encapsulation in polyethylene glycol-complexed liposomes and encapsulation with various amphiphilic polymeric materials.
[0009] Amphiphilic PEO-block-poly(L-amino acid) (PEO-b-PLAA) polymers may form micelle structures that effectively encapsulate water-insoluble drugs (G. S. Kwon et al. (1994) Colloids & Surfaces B: Biointerfaces 2, 429-434; K. Kataoka et al. (2000) J. Control. Release 64, 143-153;
[0010] M. Yokoyama et al. (1998) J. Control. Release 55, 219-229). PEO-b-PLAA micelles are unique among drug carrier systems, owing to nanoscopic dimensions, shell of PEO, and nonpolar core of PLAA, which can take up and โprotectโ water-insoluble drugs. A primary advantage of PEO-b-PLAA is the potential for encapsulation of drugs by chemical or physical means inside the core of the micelles, consisting of PLAA blocks (M. Yokoyama et al. (1992) Bioconjugate Chem. 3, 295-301; Y. Li and G. S. Kwon (1999) Colloids & Surfaces B: Biointerfaces 16, 217-226; A. Lavasanifar et al. (2000) J. Biomed. Mater. Res. 52 831-835). In either situation, it is possible to tailor the structure of a core-forming PLAA block in order to enhance properties of PEO-b-PLAA micelles for drug delivery (Y. Li, and G. S. Kwon (2000) Pharm. Res. 17(5), 607-611).
[0011] Because fungal infections are relatively difficult to treat, because systemic fungal inventions are often life-threatening, and because the antifungal antibiotics are often toxic to animals, including humans, there is a longfelt need in the art for pharmaceutical compositions comprising polyene antibiotics which are improved in relative toxicity to the patient and in release properties. Similarly, there is a need in the art for formulations of certain other pharmaceuticals, including but not limited to taxol, tamoxifen and other anticancer agents.
SUMMARY OF THE INVENTION
[0012] The present invention provides methods for formulating hydrophobic therapeutic agents such as polyene antibiotics, especially amphotericin B, such that toxicity is reduced. In particular, the polyene antibiotic is incorporated within micellar structures of block polymers comprising a hydrophilic backbone component, a spacer and a hydrophobic core. The hydrophilic backbone can be a polysaccharide, a polyethylene oxide polymer, among others, provided that it is nontoxic and suitable for parenteral administration in humans and animals and contains reactive functional groups which allow the attachment of spacer and hydrophobic core moieties. A number of suitable shell forming polymers and core forming backbones are described in U.S. Pat. No. 5,449,513. The spacer can be an alkyl, alkenyl or alkynyl moiety having from about 3 to about 10 carbon atoms, desirably 6. The hydrophobic core can be an alkyl moiety, an aryl moiety or other moiety, depending on the nature of the molecule to be encapsulated. Desirably, the molecule sizes and polarities of the spacer and core are proportioned according to the molecular dimensions and polarity properties of the polyene or other molecule (such as paclitaxel (taxol), tamoxifen or derivative) to be incorporated. Where the polyene is amphotericin B, desirably the spacer is an aliphatic molecule of about 6 carbon atoms and the core is an N-alkyl molecule of about 8 to about 28 carbon atoms, desirably 12 to 22 carbon atoms, advantageously, 12 to 18 carbon atoms, and as specifically embodied, 18 carbon atoms (stearate moiety). With reference to the structure of FIG. 1, x is from about 200 to about 400, n is from about 2 to about 8, and y+z is from about 10 to about 30. For the formulation of a larger polyene, the spacer and core are proportionately larger than those for amphotericin B. As specifically exemplified herein, the polymer backbone is a PEO of about 270 units with about 12-25 core-forming PLAA subunits, and advantageously about 22-24. See FIG. 1 for the structure.
[0013] The present invention further encompasses micelles formed by the solvent evaporation method which encapsulate AmB, other polyene or other therapeutic compounds such as taxol. Also within the scope of the present invention are freeze-dried preparations of the micelles of the present invention, as set forth above, especially those comprising a polyene such as AmB encapsulated with a PEO-b-PHSA material, especially with a block length of about 12-25. Also within the scope of the present invention are reconstituted micelles of the present invention, especially AmB-loaded micelles reconstituted in 5% sterile dextrose solution.
[0014] Where the molecule to be incorporated into the micelles is an aromatic compound, desirably the core also contains aromatic (aryl) moieties, for improved interactions between the compound to be incorporated and the amphiphilic molecule with which it is complexed for micelle formation. As specifically exemplified, the therapeutic agent-loaded micelles embodied in the present invention are formed by solvent evaporation of the solution of the therapeutic agent and the micell-forming agent, e.g., AmB and Poly(ethylene oxide)-block-poly(N-hexyl stearate L-aspartamide). The solvent evaporation technique provides surprisingly improved results with respect to toxicity and release rate as compared with prior art compositions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 presents the chemical structure of a specifically exemplified PEO-b-PHSA block copolymer and molecular model of this polymer.
[0016] [0016]FIG. 2 illustrates chemical structure of fatty acid conjugates of PEO-b-PHAA. X can be from 100 to 300, y+z can be from 10 to 30, n can be from 0 to 8, and m can be from 8 to 20. The table below shows particular polymers which have been tested.
[0017] FIGS. 3 A- 3 B show the effect of alkyl core structure on micellar size (meanยฑSE). FIG. 3A: effect of spacer group and level of fatty acid conjugation in capric acid conjugates of PEO-b-PHAA.
[0018] [0018]FIG. 3B: effect of PHAA block length in stearic acid conjugates of PEO-b-PHAA.
[0019] [0019]FIG. 4A provides fluorescence excitation spectra of pyrene in the presence of different concentrations of PEO-b-PHCA (12-15). FIG. 4B illustrates intensity ratio (339 nm/334 nm) of pyrene (6ร10 โ7 M) from excitation spectrum as a function of PEO-b-PHCA concentration. The plot is the average of three repeats of this experiment. FIG. 4C shows the effect of PHAA block length in stearic acid conjugates of PEO-b-PHAA on CMC (meanยฑSE). FIG. 4D shows the effect of spacer group and level of fatty acid conjugation in capric acid conjugates of PEO-b-PHAA on CMC (meanยฑSE).
[0020] [0020]FIG. 5A provides the fluorescence emission spectra of pyrene in the presence of different concentrations of PEO-b-PHCA (12-15), and FIG. 5B illustrates the intensity ratio (I 1 /I 3 ) of pyrene (6ร10 โ7 M) from emission spectrum as a function of PEO-b-PHCA concentration. The plot is the average of three repeats of this experiment.
[0021] [0021]FIG. 6A depicts the fluorescence emission spectrum of 1,3-(1,1โฒ-dipyrenyl)propane in micellar solutions of PEO-b-PHSA in comparison to SDS. FIG. 6B shows the effect of PHAA block length on microviscosity in stearic acid conjugates of PEO-b-PHAA.
[0022] [0022]FIG. 7 shows the hemolytic action of AmB toward human red blood cells and the effect of the drug loading method on hemolysis.
[0023] FIGS. 8 A- 8 B provide TEM images of PEO-b-PHSA micelles prepared by the solvent evaporation method (prior to freeze-drying) (FIG. 8A) and the dialysis method (FIG. 8B) (magnification of 18,000ร6).
[0024] [0024]FIG. 9 schematically illustrates the solvent evaporation method of drug loading in PEO-b-PHSA micelles.
[0025] [0025]FIG. 10 shows the effect of fatty acid substitution level in PEO-b-PHSA micelles on the hemolytic activity of AmB encapsulated by solvent evaporation.
[0026] [0026]FIG. 11 shows the effect of the drug to polymer molar ratio on hemolytic activity of AmB encapsulated in PEO-b-PHSA micelles by solvent evaporation.
[0027] FIGS. 12 A- 12 C illustrate absorption spectra of AmB (4 ฮผg/ml) in PBS, pH=7.4 (FIG. 12A); PEO-b-PHSA with 11% of stearic acid substitution (FIG. 12B); and PEO-b-PHSA with 70% of stearic acid substitution (FIG. 12C).
[0028] [0028]FIG. 13 shows the chemical structures of PEO-b-PHSA and AmB.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Abbreviations used in the present disclosure include the following: PEO-b-PLAA, Poly(ethylene oxide)-block-poly(L-aspartic acid); PEO-b-PHSA, Poly(ethylene oxide)-block-poly(N-hexyl stearate L-aspartamide); PEO-b-PBLA, Poly(ethylene oxide)-block-poly(P-benzyl-L-aspartate); PEO-b-PHCA, Poly(ethylene oxide)-block-poly(N-hexyl caprate L-aspartamide) PEO-b-PHHA, Poly(ethylene oxide)-block-poly(hydroxyhexyl L-aspartamide); AmB, Amphotericin B; DMSO, N,N-dimethylsulfoxide; DMF, N,N-dimethylformamide; SEC, Size exclusion chromatography; RBC, red blood cell; PBS, phosphate buffered saline; MIC, minimum inhibitory concentration; colony forming units, CFU, colony forming units.
[0030] The solvent evaporation method used to encapsulate AmB in PEO-b-PHSA micelles is shown in FIG. 9. AmB and PEO-b-PHSA were dissolved in methanol, and a thin film of polymer and drug was coated on a round bottom flask by evaporation of methanol under vacuum with heat. Distilled water was added to dissolve the film and form PEO-b-PHSA micelles with encapsulated AmB, and the micellar solution was filtered (0.22 ฮผm) and freeze-dried. The level of AmB in these solvent-evaporated PEO-b-PHSA micelles was 0.35 mol drug/mol polymer, and the yield of AmB encapsulation was 73% (Table 1). In contrast, the dialysis method provided 0.25 mol AmB/mol PEO-b-PHSA, and the yield of AmB encapsulation was 60%. In both cases, a higher initial level of drug resulted in higher drug content, but with an increase in hemolysis (data not shown). The reconstitution of freeze-dried samples yielded aqueous solutions having AmB levels greater than 250 ฮผg/ml. For comparison, the solubility of AmB in water is about 0.5 to 1 ฮผg/ml, and it is administered intravenously in its standard formulation, which contains sodium deoxycholate at 100 ฮผg/ml.
[0031] TEM provided evidence for the formation of spherical micelles made of PEO-b-PHSA when the solvent evaporation method was used for micelle formation and drug loading (FIG. 3A). The average diameter of PEO-b-PHSA micelles was 15.2ยฑ4.0 nm before freeze-drying. An increase in the micellar size to 22.3ยฑ4.7 nm was observed for the reconstituted samples (data not shown). PEO-b-PHSA micelles prepared by the dialysis method were also spherical (FIG. 3B), but significantly larger (average diameter of 25.0ยฑ4.9 nm) than PEO-b-PHSA micelles prepared by the solvent evaporation (P<0.0001, unpaired t test).
[0032] SEC provided evidence for the encapsulation of AmB in PEO-b-PHSA micelles. Aqueous solutions of AmB at concentrations of 1, 10 and 100 ฮผg/ml eluted from the SEC column at 17.4, 17.3 and 16.5 min, respectively. In contrast, AmB encapsulated in PEO-b-PHSA micelles formed by dialysis and solvent evaporation methods eluted at 10.6ยฑ0.1 and 10.8ยฑ0.1 min, respectively, corresponding to a molecular weight of 2.9ยฑ106 and 2.4ยฑ106 g mol โ1 based on dextran standards. This also indicates that larger PEO-b-PHSA micelles are produced by the dialysis method (unpaired t test, P<0.05), consistent with TEM images (Table 1). The encapsulation of AmB in PEO-b-PHSA micelles at 0.25-0.35 mol drug:mol polymer caused no significant change in the elution time of PEO-b-PHSA micelles (unpaired t test, P>0.05). There was no evidence of unencapsulated AmB, which elutes at about 17.4 min in the chromatography system used in the experiments described herein.
[0033] The primary advantage of the solvent evaporation method was a reduction in hemolysis caused by AmB (FIG. 7). AmB itself caused 100% hemolysis at about 1 ฮผg/ml. After encapsulation of AmB in PEO-b-PHSA micelles by the dialysis method, the drug was somewhat less toxic than AmB itself, causing 50% hemolysis at 3.8 ฮผg/ml and 100% hemolysis at 6 ฮผg/ml. In contrast, AmB encapsulated by the solvent evaporation method in PEO-b-PHSA micelles (polymer block length 22-25) was completely nonhemolytic at 22 ฮผg/ml.
[0034] The results contrast with earlier findings with Pluronics, PEO-b-poly(propylene oxide)-b-PEO, which solubilizes AmB after encapsulation by a solvent evaporation method, but fails to protect RBCs from hemolysis (D. Forster et al. (1988) J. Pharm. Pharmacol. 40, 325-328). Without wishing to be bound by any particular theory, PEO-b-PHSA micelles are believed to reduce hemolysis by slowly releasing AmB over the 30 min time period of incubation of drug with RBCs or by the release of AmB in an unaggregated state, unimers, which are known to be non-toxic for mammalian cells (J. Brajtburg, and J. Bolard (1996) Clin. Microbiol. Rev. 9 512-531). Regardless, AmB encapsulated in PEO-b-PHSA micelles by the solvent evaporation method appears to be much less toxic in vitro than the standard formulation of AmB, and a similar reduction in toxicity in vivo is achieved.
[0035] The effects of spacer chain length and hydrophobic core fatty acid chain length were studied to determine optimum combinations on the PEO-b-PLAA backbone for the encapsulation of AmB. The preparation of various fatty acid esters of PEO-b-PHAA from PEO-b-PBLA with either 15 or 24 degrees of polymerization in the PBLA block was accomplished in two steps. In the first step, 2-HP was used-as a catalyst to remove the benzyloxy group of PEO-b-PBLA and replace it with either 2-aminoethanol or 6-aminohexanol. As a result, poly(ethylene oxide)-block-poly(hydroxyethyl L-aspartamide) (PEO-b-PHEA) and poly(ethylene oxide)-block-poly(hydroxyhexyl L-aspartamide) (PEO-b-PHHA) were formed, respectively. PEO-b-PHEA and PEO-b-PHHA were then reacted with saturated fatty acids of various chain lengths ranging from 6 to 22 carbons in the presence of DCC and DMAP as coupling agent and catalyst, respectively. The general structure of the final product is shown in FIG. 2. Thin layer chromatography using diethyl ether: dichloromethane (20:80) as the mobile phase and 0.1% solution of bromocresol in ethanol as an indicator confirmed the purity of block copolymers from free fatty acids.
[0036] [0036] 1 H NMR was used to estimate the level of fatty acid substitution on PEO-b-PHAA. Because the molecular weight of the PEO block was known and the purity of the synthesized copolymers was confirmed by TLC, comparison of characteristic peak intensities of fatty acid substituents (CH3-, ฮด=0.8 ppm) to that of PEO (โCH2-CH2-Oโ, ฮด=3.6 ppm) provides an estimation of the degree of fatty acid attachment. The substitution of fatty acid is expressed as the percentage of conjugated stearic acid to hydroxyl groups of PEO-b-PHAA throughout the present application. Statistical analysis (ANOVA, Duncan's test) of the data obtained for different batches of synthesized polymers (with varied fatty acid chain lengths) reveals that the use of longer spacer groups significantly (P<0.01) increases the level of fatty acid substitution on the PHAA block.
[0037] Micellization of the fatty acid conjugates of PEO-b-PHAA having different core structures was achieved using a dialysis method, and the formation of micelle like structures was investigated by TEM. The TEM images clearly indicate the presence of spherical particles with nanoscopic dimensions. However, a tendency towards the formation of ellipsoids is seen when longer fatty acids (myristic and stearic) attached to C 6 spacer group with higher degrees of substitution (ca. 65%) were used.
[0038] The average diameter of the prepared micelles measured from TEM images for 12-15 samples was found to be between 14.7-21.8 nm (Table 1). Increasing the substitution level of fatty acid on the polymeric backbone caused a significant increase (P<0.001) in micellar size as s shown for poly(ethylene oxide)-block-poly[N-(6-hexyl caprate)-L-aspartamide] (PEO-b-PHCA) in FIG. 3A (7% vs 44%). The length of the spacer group showed no significant effect when micellar size was compared in capric acid conjugates of PEO-b-PHEA and in hexyl conjugates of PEO-b-PHHA with the same degree of fatty acid attachment (FIG. 3A). Increasing the length of the fatty acid chain caused a significant increase in micellar size (P<0.001) when polymer batches with similar degree of fatty acid attachment were compared (Table 1). The average diameter of stearic acid conjugates of PEO-b-PHEA and PEO-b-PHHA for 12-24 samples was measured to be between 23.3 to 25.3 nm. An increase in the length of the PLAA block from 15 to 24 also showed an enhancing influence (un paired t test, P<0.001) on micellar size when block copolymers with the same degree of stearic acid substitution on the PHEA or PHHA blocks were compared (FIG. 3B). The substitution level of stearic acid on the PHEA and PHHA block was calculated to be 45 and 60%, respectively in both PEO block length 12-15 and 12-24 samples.
[0039] Pyrene was used as a fluorescent probe to determine the CMCs and the micropolarities of the core for micelles formed from fatty acid esters of PEO-b-PHAA. Following partitioning of pyrene into the micellar core at polymer levels above CMC, a red shift is seen in the excitation spectrum of pyrene (FIG. 4A). Therefore, the ratios of peak intensities at 339 nm over 334 nm are plotted vs. the logarithm of polymer concentration to determine CMC (FIG. 4B). The CMC is measured from a sharp rise in the intensity ratios at the onset of micellization (R. Nagarajan et al. (1986) Langmuir 2, 210; J. Georges (1990) Spectrochimica Acta Reviewes 13, 27; M. Winnik, S. T. A. Regismond, Colloids & Surfaces A: Physicochemical & Engineering Aspects 118 (1996) 1; G. S. Kwon et al. (1993) Langmuir 9, 945). The average CMCs for the polymeric micelles under study ranged from 9 to 50 ฮผg/mL. Elongation of the fatty acid did not significantly affect CMC values obtained from this method of measurement (Table 1). As it is shown in FIGS. 4C and 4D, no significant effect (P>0.05) on CMC was observed when block copolymers with longer PHAA block or spacer group but similar level of fatty acid substitution were used, respectively. The substitution level of fatty acid on the PHAA block seems to be the major factor controlling the onset of micellization. As it is illustrated in FIG. 4D, a decrease in the level of capric acid attachment from 44 to 7% results in a reduced tendency for self-association in PEO-b-PHCA. The mean CMC value rose from 29 to 57 ฮผg/ml in PEO-b-PHCA with 7% capric acid substitution.
[0040] The fluorescence emission spectrum of pyrene was also affected by the polarity of its environment (FIG. 5A). A sharp decrease in the relative intensity of the first (I 1 ) to the third band (I 3 ) was observed at the CMC as pyrene partitions to the non-polar core of the micelles (FIG. 5B). The I 1 /I 3 ratios obtained from emission spectra of pyrene in the presence of 500 ฮผg/mL of fatty acid ester of PEO-b-PHAA (12-15) are reported in Table 1. A ratio of 1.4 was observed for aqueous pyrene, which is in agreement with previous observations (J. Georges (1990) Spectrochimica Acta Rev. 13, 27). At low polymer concentrations, the ratio was close to what has been found for water. As the concentration of the polymer increased, the I 1 /I 3 ratio dropped to about 1.0. The reduced value of I 1 /I 3 ratio indicates non-polar microdomains in micelles, with polarities similar to n-pentanol in the pyrene scale (Dong et al. (1984) Can. J. Chem. 62, 2560). No significant effect on I 1 /I 3 was detected when different structural factors were altered in fatty acid conjugates of PEO-b-PHAA, P>0.05 (Table 1, FIG. 5B).
[0041] Evidence for the limited motion of fatty acid esters in the micellar core was obtained from the fluorescence emission spectrum of 1,3-(1,1โฒ-dipyrenyl)propane in the presence of 500 ฮผg/mL of polymeric micelles (FIG. 6A). Like pyrene, 1,3-(1,1โฒ-dipyrenyl)propane is a hydrophobic fluorescent probe that preferentially partitions into the hydrophobic micro-domains of micelles at polymer concentrations above the CMC. By changing its conformation, 1,3-(1,1โฒ-dipyrenyl)propane forms intramolecular pyrene excimers that emit light at 480 nm when excited at 390 nm. The conformational change in 1,3-(1,1โฒ-dipyrenyl)propane probe is restricted by a local friction imposed by the viscosity of its environment. Therefore, the ratio of the intensity of the light emitted from excited dipyrene excimer (I e ) to that of isolated pyrene monomer (I m ) in its emission spectrum is used as a measure of effective viscosity (Georges (1990 supra). As shown in Table 1 and FIG. 6, I e /I m ratios are very low for all the copolymers under study, reflecting rigid structures for the polymeric micellar cores. In contrast, a high incidence of excimer formation in sodium lauryl sulfate (SDS) reflects the liquid like core of a low molecular weight surfactant (FIG. 6A). No significant change (P>0.05) in I e /I n ratios was detected for different fatty acids attached to the polymeric backbone in 12-15 samples (Table 1). However, behenic acid conjugates of PEO-b-PHHA with substitution levels of 65% showed lowered I e /I m ratio (0.08) in comparison to other copolymers (Table 1). Beside this specific structure, lower average I e /I m ratios in 12-24 samples of poly(ethylene oxide)-block-poly[N-(2-ethyl stearate)-L-aspartamide] (PEO-b-PESA) poly(ethylene oxide)-block-poly[N-(6-hexyl stearate)-L-aspartamide] (PEO-b-PHSA) compared to 12-15 species indicates the elongation of the PHAA block causes more restricted motions in the micellar core environment as well (FIG. 6B).
[0042] It is known that amphiphilic block copolymers can form supramolecular core/shell structures in aqueous environment through the expulsion of their hydrophobic segments from water and further hydrophobic association of these blocks. Supramolecular self-assembled structure plays an analogous role to natural carriers with several advantages such as ease of chemical modification, stability and safety (Kwon et al. (1999) Pharm. Res. 16, 597; G. S. Kwon (1998) Crit. Rev. Ther. Drug Carrier Syst. 15, 481). To achieve optimized micellar properties and drug loading capacities we pursued the chemical tailoring of the core structure in PEO-b-PLAA in our recent research studies. Compatibility between the solubilizate and the core-forming block is proven to be necessary for efficient solubilization of water insoluble molecules in micellar systems (Allen et al. (1999) Colloids & Surfaces B: Biointerfaces 16, 3; Yokoyama et al. (1998) J. Control. Release 55, 219; Nagarajan et al. (1986) Langmuir 2, 210; Yokoyama et al. (1998) J. Control Release 50, 79). With this in mind, the chemical structure of the core-forming block in PEO-b-PLAA was tailored to aliphatic ones to enhance the solubilization of compatible drugs such as the polyene antibiotics, especially AmB.
[0043] Chemical modification of the core structure in PEO-b-PLAA block copolymers was carried out through replacement of benzyloxy group in PEO-b-PBLA with hydrophobic spacers having hydroxyl termini. These products were further conjugated with different fatty acids to form fatty acid conjugates of PEO-b-PHAA (FIG. 2). 1 H NMR was used to measure the degree of fatty acid substitution. Attachment of a hydrophobic spacer introduces hydroxyl functional moieties to the side chains which could react with the carboxyl groups of the fatty acids. Increasing the length of the spacer group from 2 to 6 carbon atoms facilitates an increase in the degree of side chain attachment to the PHAA block. Without wishing to be bound by any particular theory, this is believed to result in a rearrangement of the hydroxyl groups away from the polymeric backbone, i.e., reduced steric hindrance, when hexyl spacers were used instead of ethyl spacers. Using the same method of synthesis, block copolymers with different structures of the core-forming block were prepared, purified, dissolved in DMF and dialyzed against water to form micellar structures. The micellar properties were determined for each structure by TEM and fluorescent probe techniques.
[0044] The data presented herein show that PEO-b-PLAAs with alkyl core structures mimic certain aspects of biological carriers for hydrophobic molecules. They self-assemble into nanoscopic, supramolecular core/shell structure where the core is rich in fatty acid esters. The shape of these micelles is spherical, except for highly substituted myristic, stearic and behenic conjugates of PEO-b-PHHA, which tend toward the formation of ellipsoids. It is believed this is due to the larger dimensions of the hydrophobic block in those constituents. Low CMC values measured for fatty acid conjugates of PEO-b-PHAA indicate a high tendency of these amphiphilic structures toward self-association in aqueous environments which tendency for self association reflects their thermodynamic stability in aqueous environments. The aliphatic core of the polymeric micelles described herein also appear rigid. Micelles with glassy cores tend to disassemble more slowly than those with a mobile core (Kataoka et al. (1993) J. Control. Release 24, 119). As a result, even at concentrations below the CMC, the micelles are dynamically stable and survive for a significant time in vivo.
[0045] The alkyl core of the polymeric micelles in our studies was essentially varied in four structural aspects: the length of the PLAA block, the length of the alkyl spacer, the length of the attached fatty acid and the substitution level of fatty acid on the polymeric backbone.
[0046] The substitution level of fatty acids on the polymeric backbone is the major factor affecting micellar size, shape, CMC and micropolarities. The effect of the fatty acid substitution level was investigated in PEO-b-PHCA block copolymers with two different degrees of capric acid attachment. An increase in the fatty acid content of the micellar core caused an increase in micellar size (P<0.0001, unpaired t test) and a decrease in CMC (P<0.05, unpaired t test). Average micellar size was enhanced when capric acid content of the core was increased from 7 to 44%. Increased micellar size (in the dry state) is believed to be a consequence of larger dimensions of the hydrophobic block in those structures. Owing to the hydration of the PEO surface, micellar size shows an increase in aqueous environments. However, the enhanced hydrophobicity of the core-forming block may restrict this hydration and affect the final size of the polymeric micelles in vivo. Accordingly, the results obtained from TEM measurements cannot be simply extrapolated to micellar dimensions in aqueous environments. Reduced CMC values for block copolymers with higher levels of capric acid attachment reflects the reduced free energy of micellization for those polymers. Preferential expulsion of the copolymers with larger hydrophobic segments from water (greater entropic driving force) is assumed to be the reason behind this observation. PEO-b-PHCA with 7% of capric acid attachment exhibited greater micropolarities at 500 ฮผg/ml concentration (I 1 /I 3 =1.3). The I 1 /I 3 in this case is even higher than values measured for benzyl core in PEO-b-PBLA at the same concentration (Lavasanifar et al. (2000) J. Biomed. Mat. Res. 52, 831-835). The higher I 1 /I 3 ratios could result from high core polarities due to the expression of OH groups in the micellar core. However, incomplete localization of the pyrene probe in the micellar core could cause the same effect. This, in turn, is a result of reduced hydrophobicity in the core region when polymeric micelles with capric acid substitutions as low as 7% are used. At 7% substitution, the amount of fatty acid is not sufficient to overcome the high polarities resulting from the free hydroxyl groups present in the micellar core. Polar groups in the micellar core make the drug-loaded micelles more susceptible to dissociation and hydrolysis. Interestingly, no difference in micellar core viscosity was observed between the two species. The formation of the 1,3-(1,1โฒ-dipyrenyl)propane excimer was considerably restricted in PEO-b-PHCA even at 7% fatty acid substitution. This result is in contrast to SDS, which shows high ratios of I e /I m (FIG. 6).
[0047] Application of block copolymers with different lengths of the PLAA block induced changes in micellar size and core viscosity. Average micellar size was increased when length of the PHEA and PHHA was increased at the similar level of stearic acid substitution as illustrated in FIG. 3B. Increasing hydrophobic block length showed no detectable effect on CMC measured from partitioning of pyrene in micellar core (FIG. 4C). This finding seems to contradict previous observations (Kwon et al. (1993) Langmuir 9, 945). The presence of hydroxyl groups in the core-forming block might have hindered the effects of the block elongation in reducing CMC. Like CMC, micellar core polarity was not affected by block length, as shown in FIG. 5. Micellar core viscosity, however, was influenced by the length of the PLAA block. More rigid cores were formed when the length of PLAA was elongated from 15 to 24 (FIG. 6B). This, in turn, results in the formation of polymeric micelles with greater dynamic stability, and particle movements into or out of the core region are restricted. Collapsed conformation of the PLAA blocks in micellar core and difference in aggregation numbers are among factors causing this effect.
[0048] The length of the spacer group showed no significant effect on dialysis-prepared micellar properties. Its effect on micellar size and CMC is compared in FIGS. 3A and 4D, respectively, for PEO-b-PECA and PEO-b-PHCA having similar degrees of capric acid attachment. The difference observed in micellar size (FIG. 3B) and CMC (FIG. 4C) between PEO-b-PESA and PEO-b-PHSA is, therefore, most likely a result of an increase in the level of stearic acid substitution from 45 to 60 percent.
[0049] Except for micellar size, other properties of the system were not detectably affected when length of the fatty acid attached to the polymeric backbone was changed (Table 1), except that attachment of behenic acid (22-carbon chain) to a hexyl spacer in a high level of substitution caused an increase in core viscosity (decrease in core mobility). This unique structure lowered the formation of dipyrene probe excimer reflecting higher local viscosity in the micellar core in comparison to other polymeric micelles (Table 1). The same chemical structure with 50% of behenic acid attachment showed similar I e /I m ratios in comparison to other structures, reflecting similar microviscosities.
[0050] Fatty acid esters of PEO-b-PHAA can be used for drug delivery as they form nanoscopic, core/shell micellar structures at very low concentrations where the core is relatively solid at room temperature. Structural modifications can be made in the core-forming block, and thus, polymeric micelles with optimized structures for the purpose of drug delivery can be designed and prepared using the teachings of the present disclosure taken with what is well known to the art. We have shown that varying the levels of fatty acid side chain and the length of the PHAA block are major factors by which the micellar structure can be tailored. Changing the level of fatty acid attachment affects micellar size, thermodynamic stability and micropolarities, whereas varying the length of the PHAA block in PEO-b-PLAA copolymers regulates micellar core viscosity, and higher core viscosities are associated with decreased dissociation rates of the loaded micelles. Increasing the core viscosity can also be achieved by conjugation of fatty acids having long chains (>22 carbon atoms) at a high level of substitution on the polymeric backbone.
[0051] Encapsulation of AmB by PEO-b-PHSA micelles was enhanced by an increase in the level of stearic acid substitution on the PHSA block (Table 3). The level of AmB encapsulated in PEO-b-PHSA micelles at 11, 50 and 70% stearic acid substitution was 0.22, 0.35 and 0.36 mol drug:mol PEO-b-PHSA. The yield of encapsulated AmB for PEO-b-PHSA micelles was 51, 73 and 77%, respectively.
[0052] An increase in the level of stearic acid substitution in PEO-b-PHSA micelles reduced the ability of AmB to cause hemolysis (FIG. 10). At 50 and 70% stearic acid substitution AmB was completely non-hemolytic at 22 ฮผg/ml. However, AmB at 11% stearic acid substitution was almost as hemolytic as AmB itself, causing 50% hemolysis at 1 ฮผg/ml and 100% hemolysis at 3 ฮผg/ml.
[0053] The effect on hemolysis was also dependent on the content of AmB in the PEO-b-PHSA micelles (FIG. 11). PEO-b-PHSA micelles at 0.36 mol drug: mol polymer were completely non-hemolytic at 22 ฮผg/ml of AmB. On the other hand, PEO-b-PHSA micelles at 0.89 mol drug: mol polymer caused 80% hemolysis at a similar level of drug.
[0054] The UV/VIS spectra of encapsulated AmB in PEO-b-PHSA micelles prepared by the solvent evaporation method with 11 and 70% of stearic acid substitution and AmB itself in PBS are shown in FIG. 12. A change in the UV spectrum of AmB reflects conformational changes in AmB molecule as a result of self-association or interaction with other compounds. The UV spectrum of AmB encapsulated in PEO-b-PHSA micelles with 11% of stearic acid substitution was very similar to the UV spectrum of free AmB. At 4 ฮผg/ml a broad absorption peak centered at 334 and three additional peaks at 364, 385 and 409 nm were observed (FIGS. 12A and 12B). The absorption peaks for AmB encapsulated in PEO-b-PHSA micelles having 70% of stearic acid substitution shifted to the red side, showing peaks at 351, 366, 387 and 415 nm (FIG. 12C). The intensity ratio at 348 nm (peak I) to that at 409 nm (peak IV) is a measure for self-aggregation state of AmB. The I/IV ratio for AmB in PBS was about 1.2 at a level of 4 ฮผg/ml (FIG. 12A). At a similar level, for AmB encapsulated in PEO-b-PHSA micelles with 11 and 70% of stearic acid substitution, the I/IV ratio was 2.1 and 1.8, respectively (Table 3).
[0055] The antifungal activity of encapsulated AmB was compared to AmB itself by estimating MICs against the growth of three pathogenic fungi. Fungi growth was examined by an inverted microscope (ร40). AmB in an isotonic solution inhibited the growth of C. albicans, C. neoformans and A. fumigatus at 0.3, 0.3 and 0.45 ฮผg/ml, respectively (Table 4). AmB encapsulated in PEO-b-PHSA micelles was as effective as AmB itself in most of the cases. At 11 and 50% of stearic acid substitution, encapsulated AmB was even more effective than AmB itself inhibiting the growth of C. neoformans at a level of 0.18 ฮผg/ml. (Unpaired t test, P<0.01). PEO-b-PHSA micelles without AmB were unable to inhibit the fungal growth at 5 mg/ml level or below.
[0056] The importance of compatibility between the core-forming block and the solubilizate has been shown in polymeric micelles (Yokoyama et al. (1998) J. Control. Release 50, 79-92; Yokoyama et al. (1998) J. Control. Release 55, 219-229; Nagarajan et al. (1986) Langmuir 2, 210-215). We explored this concept for a model aliphatic drug, AmB, and tailored the chemical structure of the core in PEO-b-PLAA micelles through attachment of aliphatic structures, i.e. fatty acids, to improve micellar properties for drug delivery. The effect of alternations in the alkyl core structure on properties of micelles formed from PEO-b-PLAA derivatives has been described herein. The effect of structural modifications namely degree of fatty acid substitution on the core-forming block on the encapsulation, hemolytic activity and anti-fungal efficacy of AmB has also been addressed herein.
[0057] The chemical structure of the core-forming block was changed in the PEO-b-PHSA block copolymers in terms of the degree of stearic acid substitution. PEO-b-PHSA block copolymers with three levels of stearic acid substitution were prepared and used to encapsulate AmB by solvent evaporation. An increase in the level of stearic acid substitution enhanced AmB encapsulation (Table 3) while reducing its membrane activity toward red blood cells (FIG. 10). Under identical loading conditions, the yield of AmB encapsulation was 51, 72 and 77% for polymers with 11, 50 and 70% of stearic acid substitution, respectively (Table 3). AmB in 11% substituted polymer caused 100% hemolysis at 3 ฮผg/ml but it was non-hemolytic at 22 ฮผg/ml after encapsulation in PEO-b-PHSA micelles with 50 and 70% of stearic acid substitution (FIG. 10). The extinction of hemolytic activity of AmB obtained by encapsulation in PEO-b-PHSA micelles was acquired at a drug content of 0.4 mol AmB: mol PEO-b-PHSA but was not as much at a 0.9 mol drug: mol polymer ratio (FIG. 11).
[0058] [0058]FIG. 7 shows that AmB loaded in micelles prepared by the solvent evaporation method are significantly reduced in hemolytic activity as compared with micelles loaded by dialysis. The hemolytic activity of AmB in an uncomplexed form is also shown.
[0059] [0059]FIGS. 8A and 8B compared AmB-loaded micelles prepared by the solvent evaporation and dialysis methods, respectively. The solvent evaporation method is shown in FIG. 9.
[0060] Despite reduced toxicity toward human red blood cells, encapsulated AmB in PEO-b-PHSA micelles remained active against pathogenic fungi in vitro. The antifungal activity of AmB was not affected by the level of stearic acid substitution in the micellar carrier (Table 4).
[0061] AmB binds to serum lipoproteins, which have cores rich in triglycerides, and interacts with lipid bilayer membranes (Brajtburg and Bolard (1996) Clin. Microbiol. 9, 512-531). The conformational change in AmB molecule as a result of this interaction causes a bathochromic shift in the position of peak IV from 409 nm (for monomeric AmB) to 414 nm (for AmB complex) in its UV/VIS spectrum (Barwicz et al. (1991) Biochem. Biophys. Res. Comm. 181-722-728). We observed a similar shift in the UV/VIS spectra of AmB in PEO-b-PHSA micelles with higher levels of stearic acid substitution (FIGS. 12A and 12C). Therefore, a preferential encapsulation of AmB in PEO-b-PHSA micelles with more fatty acid esters in the core appears to be caused by a favorable interaction between the drug and the lipid core. The same reason might have caused a sustained drug release from micellar systems with high levels of fatty acid esters in the core leading to AmB delivery in a monomeric state. Monomeric AmB is non-toxic towards mammalian cells but active against fungal cells. In contrast, AmB encapsulated in PEO-b-PHSA micelles with 11% of stearic acid substitution absorbs UV light at similar wavelength as AmB itself (409 nm) reflecting lack of interaction (FIG. 12B). In comparison to AmB itself, a higher I/IV ratio of AmB in PEO-b-PHSA micelles with low levels of stearic acid substitution, instead, indicates the presence of encapsulated AmB aggregates (Table 3). A rapid or aggregated AmB release might be the cause of AmB toxicity towards red blood cells in micelles with lower levels of fatty acid substitution or higher drug content.
[0062] The level of stearic acid substitution in PEO-b-PHSA can be adjusted to enhance encapsulation and efficacy of AmB as a result of enhanced interaction with the micellar core. The attenuated in vitro toxicity of AmB in PEO-b-PHSA micelles with higher levels of stearic acid substitution reflects a crucial role for controlling the rate of AmB release. Thus, PEO-b-PHSA micelles with higher levels of fatty acid esters in the core act as a nanoscopic depots with long circulating properties for AmB delivery. The efficacy of AmB is improved for long-circulating liposomal AmB in a murine model of candidiasis (Van Etten et al. (1998) Antimicrob. Agent. Chemother. 42, 2431-2433). The long circulating system also reduces the dose, the risk of long-term toxicities and the cost of AmB therapy associated with the administration of standard lipid formulations of AmB.
[0063] In sum, chemical tailoring of the core in PEO-b-PLAA micelles via increasing the presence of compatible moieties, i.e. fatty acid esters, leads to a better encapsulation and reduced hemolytic activity for AmB. As a result, the polymeric micellar formulation of the present invention, which is made by solvent evaporation technology, provides effective solubility, reduced hemolytic activity and good antifungal efficacy for AmB in vitro and in vivo. PEO-b-PHSA self assembles into micelles that encapsulate AmB by a solvent evaporation method, the overall concentration of AmB in water is clinically relevant for use in humans and animals for systemic fungal diseases, and the toxicity of the AmB in terms of hemolysis is dramatically decreased over prior art formulations.
[0064] The encapsulated AmB-containing compositions of the present invention are improved with respect to toxicity and with respect to release properties. It has been demonstrated that the present compositions are effective in inhibiting the growth of representative fungal pathogens in vitro. These compositions are similarly effective in vivo after administration by a parenteral route, desirably by intravenous injection, and especially by intravenous perfusion. Pathogenic fungi against which the AmB of the present invention is effective include, without limitation, species of Histoplasma, Cryptococcus, Candida, Aspergillus, Blastomyces, Mucor, Torulopsis, Rhizopus, Absidia, and causative agents of coccidiodomycosis and paracoccidioidomycosis, among others. Anticancer agents such as taxol and the antineoplastic derivatives of taxol are also reduced in toxicity when encapsulated in micelles according to the present invention and delivered by parenteral administration, for example by intravenous injection or infusion. It is preferred that the drug-loaded micelles of the present invention are freeze-dried after preparation and stored in the dry state in a manner consistent with maintenance of the activity of the drug, as known in the art for a particular drug. The dry micelles are reconstituted in a pharmaceutically acceptable carrier such as sterile physiological saline or a sterile dextrose solution, e.g., 5% dextrose, and after thorough hydration, they can be filtered (optionally through a 0.22 ฮผm filter) prior to administration. The micelles of the present invention are administered at a similar dosage as is Amphotericin B in prior art liposomal forms.
[0065] All references cited in the present application are incorporated by reference herein to the extent that there is no inconsistency with the present disclosure.
[0066] The following examples are provided for illustrative purposes, and are not intended to limit the scope of the invention as claimed herein. Any variations in the exemplified articles which occur to the skilled artisan are intended to fall within the scope of the present invention.
EXAMPLES
Example 1
Synthesis of Fatty Acid Esters of PEO-block-poly(hydroxy-alkyl L-aspartamide)
[0067] The synthesis of PEO-b-PBLA block copolymers is described in detail elsewhere (Yokoyama et al. (1992) Bioconj. Chem. 3, 295). PEO-b-PBLA block copolymers were synthesized by ring-opening polymerization of b-benzyl L-aspartate N-carboxyanhydride using ฮฑ-methoxy-ฯ-amino-PEO as an initiator (M n =12,000 gmole โ1 , M w /M n =1.05, amine functionality=0.96). Based on 1 H NMR spectroscopy, the degree of polymerization of the PBLA block in the samples was either 15 or 24. To differentiate between these samples, a nomenclature of 12-15 or 12-24 is defined in this paper based on molecular weight of the PEO block (12000 gmole โ1 ) and the degree of polymerization of the PLAA block (15 or 24).
[0068] PEO-b-PBLA (0.10 mmol BLA units) was dissolved in dried N,N-dimethylformamide (DMF) (5 mL) with the aid of stirring and slight heating. Subsequently, 2-aminoethanol or 6-aminohexanol (10 eq) and 2-HP (0.3 mmol) were added. The reaction mixture was stirred for 24 h at 25ยฐ C. and poured into vigorously stirred cold isopropanol (50 mL). The white precipitate was washed with isopropanol and diethyl ether and dried under vacuum. The complete removal of benzyl groups was evidenced by 1 H NMR in chloroform-d (AM-300 MHz) and by absorption spectroscopy (Milton-Roy 3000).
[0069] In the second step, PEO-b-poly(hydroxyalkyl L-aspartamide) (PEO-b-PHAA) (12-15) was esterified with either hexanoic (C=6), capric (C=10), myristic (C=14), stearic (C=18) or behenic acid (C=22). Fatty acid (5 eq), DCC (0.070 mmol) and DMAP (0.010 mmol) were added to a solution of PEO-b-PHAA (0.003 mmol HAA units) in dried dichloromethane (5.0 mL). The mixture was stirred at room temperature for 24 h. The product was precipitated in cold isopropanol (50 mL), washed with either isopropanol or diethyl ether, collected by centrifugation and dried under vacuum. The same method of preparation was used to attach stearic acid to PEO-b-PHAA (12-24). The products were characterized by 1 H NMR in chloroform-d (AM-300 MHz).
[0070] Unless otherwise noted, PEO-b-PHSA was prepared from PEO-block-poly(_-benzyl L-aspartate) (PEO-b-PBLA) as described previously (Lavasanifar et al. (2000) J. Biomed. Mater. Res. 52 (2000) 831-835). The molecular weight of PEO and the number of BLA units in PEO-b-PBLA were 12,000 g mol โ1 (M w /M n =1.05) and 24, respectively. Briefly, PEO-b-PBLA was reacted with 6-aminohexanol at 25ยฐ C. in the presence of 2-hydroxypyridine as a catalyst. PEO-block-poly(hydroxyhexyl L-aspartamide) (PEO-b-PHHA) was formed, providing hydroxyl groups in the side chains. Stearic acid was then reacted with PEO-b-PHHA in dry dichloromethane with the aid of dicyclohexylcarbodiimide and dimethylaminopyridine. The reaction time was varied between 2 and 72 hr to achieve varied levels of stearic acid substitution on the PHHA block. The degree of fatty acid substitution (mol stearic acid: mol reacted and unreacted hydroxyl groups) was estimated by 1 H-NMR in chloroform-d (AM-300 MHz).
Example 2
Micelle Formation From Fatty Acid Esters of PEO-b-PHAA
[0071] In experiments carried out to compare fatty acid aliphatic chain length, the dialysis method was used to prepare micelles. Micellization of polymers was achieved by dissolving 15 mg of each polymer in 4.0 ml of DMF with the aid of slight heat. Doubly distilled water was then added to this solution in a drop-wise manner (one drop per 20 s) until the final water concentration was 10-15% (v/v). A dialysis membrane with a molecular cutoff of 12,000-14,000 gmole โ1 was used to replace the organic solvent with distilled water overnight at room temperature replacing the medium three times. Micelles were then passed through 0.22 ฮผM filters.
[0072] In certain other experiments, the dialysis method as described in Lavasanifar et al. (2000) supra was used. AmB (400 mg) and PEO-b-PHSA (20 mg) were both dissolved in 1.2 ml of N,N-dimethylsulfoxide. Distilled water was added to the solution in a drop-wise manner (1 drop/20 sec) until the water content reached 80% v/v. The solution of AmB and PEO-b-PHSA was dialysed against distilled water overnight, filtered (0.22 ฮผm) and freeze-dried.
[0073] The solvent evaporation method for the preparation of AmB-encapsulated micelles is as follows. AmB (470 ฮผg or 2 mg) and PEO-b-PHSA (20 mg) were dissolved in methanol (5.0 ml or 10 ml) in a round bottom flask. Methanol was evaporated under vacuum at 300 mm Hg at 40ยฐ C. in 15 min. Alternatively, the solvent evaporation can be accomplished at room temperature at a pressure of about 100 mm Hg or at about 33ยฐ C. and about 200 mm Hg. Distilled water was added to the polymer/drug film, the solution was incubated at 40ยฐ C. for 10 min and vortexed for 30 seconds afterwards. The micellar solution was filtered (0.22 ฮผm) and freeze-dried.
[0074] The freeze-dried samples of AmB in PEO-b-PHSA micelles were reconstituted in water and filtered (0.22 ฮผm). An aliquot of the solution in water was diluted with an equal volume of N,N-dimethylformamide (DMF), and the drug content measured from the UV/VIS absorbance of AmB at 412 nm (Pharmacia Biotech Ultraspec 3000).
[0075] As an alternative to the solvent evaporation technique described herein for the incorporation of a polyene antibiotic into amphiphilic polymer micelles, one can also produce micelles having properties about the same as those prepared by solvent evaporation as described herein by rapidly jetting in the polyene antibiotic (or other compound of interest) into warm water containing the amphiphilic polymeric material dissolved in a solvent such as methanol or chloroform, with rapid mixing, and subsequent recovery of the drug-loaded micelles. The micelles can then be freeze dried as described herein.
Example 3
Transmission Electron Microscopy (TEM)
[0076] Samples for TEM were prepared by placing 20 ฮผl of polymeric micellar solution (1.0-1.5 mg/ml) on a copper-coated grid. A portion (20 ฮผl) of 2% phosphotungstic acid in water was added as the negative stain. After 1 min excess fluid was removed using filter paper, and images were obtained at a magnification of 18,000 times (75 kV) (Hitachi H 7000). Apparent micellar diameters were measured, and a mean diameter +SD was calculated based on at least 120 measurements.
Example 4
Size Exclusion Chromatography (SEC)
[0077] AmB was dissolved in 0.10 M phosphate buffer, pH 7.4, with the aid of N,N-dimethylsulfoxide (DMSO) to provide concentrations from 1.0 to 100 ฮผg/ml. The amount of DMSO in the final product was <1% (v/v). Freeze-dried PEO-b-PHSA micelles with or without AmB were dissolved in a 0.10 M phosphate buffer to provide a level of 0.5 mg/ml for polymer. Samples of 125 ฮผl were injected into a Hydrogel 2000 (Waters) column after it was equilibrated with phosphate buffer 0.10 M (pH=7.4) at a flow rate of 0.8 ml/min (Waters B 15 LC system). Eluted material was detected using a UV/VIS detector (Waters 486) set at 210 and 410 nm for PEO-b-PHSA and AmB, respectively. The column was calibrated with dextran standards (8.05H10 5 B9.11H10 6 g mol โ1 ) using refractive index detection (Precision Detectors 2000).
Example 5
UV/VIS Spectroscopy
[0078] Freeze-dried samples of AmB in PEO-b-PHSA micelles with 11 and 70% stearate substitution were dissolved in PBS, pH=7.4, at 4 ฮผg/ml of AmB. DMSO was used to solubilize AmB in PBS, pH=7.4, at a similar concentration. The level of DMSO in the final sample was <1% (v/v). The UV/VIS spectra of AmB in different samples were recorded from 300 nm to 450 nm.
Example 6
Hemolytic Activity of AmB Toward Human Red Blood Cells
[0079] Human blood was collected and centrifuged (2000 rpm). The supernatant and buffy coat were pipetted off and the red blood cells (RBCs) were diluted with an isotonic phosphate buffer, pH 7.4. The proper dilution factor was estimated from the UV/VIS absorbance of hemoglobin at 576 nm in the supernatant after RBCs were lysed by 20 ฮผg/ml of AmB. A properly diluted sample of RBCs gives an absorbance of 0.4-0.5. Solutions of diluted RBCs (2.5 ml) with varied levels of AmB in different samples were incubated at 37ยฐ C. for 30 min. Samples were then placed in ice to stop hemolysis. The unlysed RBCs were removed by centrifugation at 14,000 rpm (about 7000ร g) for 20 sec. The supernatant was collected and analyzed for hemoglobin by UV/VIS spectroscopy at 576 nm. The percent of hemolyzed RBCs was determined using this equation: % hemolysis=100(AbsโAbs o )/(Abs 100 โAbs o ), where Abs, Abs o and Abs 100 are the absorbance for the sample, control with no AmB and control in the presence of 20 ฮผg/ml AmB, respectively.
Example 7
Minimal Inhibitory Concentration (MIC) of AmB
[0080] AmB in PEO-b-PHSA micelles was dissolved in isotonic sodium chloride solution giving an AmB level of 200 ฮผg/ml. AmB was dissolved in DMSO and diluted further with the isotonic sodium chloride solution to give the same concentration. The level of DMSO in the final solution was <1% v/v. Samples of PEO-b-PHSA micelles in sodium chloride solution were also used as controls. Solutions of 20 ฮผl from these samples were diluted with the culture medium (RPMI 1640) (80 ฮผl) in the first microwell. The next 11 microwells had serial two-fold diluted solutions. To each microwell, 100 ฮผl of the inoculum containing 5ร10 3 CFU/ml of fungal pathogen ( Candida albicans, Aspergillus fumigatus or Cryptococcus neoformans ) in culture medium was added, giving a total volume of 200 ฮผl per well. Microwell containers were incubated at 35ยฐ C. for 24 hr. Organism and medium controls were performed simultaneously to check the growth of organisms and sterility of culture medium, respectively. The MIC was defined as the minimum concentration of AmB that shows a full inhibition of fungal growth in the well, when examined using an inverted microscope (H40). All tests were repeated three times.
Example 8
Estimation of the Critical Micelle Concentration and Micellar Core Polarity by Fluorescent Probe Techniques
[0081] By following changes in the fluorescence excitation and emission spectra of pyrene in the presence of varied concentrations of block copolymers, the critical micelle concentration (CMC) and the polarity of the micellar core for each block copolymer were determined, respectively. Pyrene was dissolved in acetone and added in a known amount to 5 ml volumetric flasks to provide a concentration of 6 H 10 โ7 M in the final solutions. Acetone was then removed and replaced with aqueous polymeric micellar solutions (5 ml) with concentrations ranging from 0.5 to 1000 ฮผg/ml. Samples were heated at 65EC for an hour, cooled to room temperature overnight and deoxygenated with nitrogen gas prior to fluorescence measurements. The excitation and emission spectrum of pyrene for each sample was then obtained using Fluoromax DM-3000 fluorescence spectrometer at room temperature. For fluorescence emission spectra, the excitation wavelength was chosen at 339 nm and for excitation spectra, the emission wavelength was set at 390 nm. Spectra were accumulated with an excitation and emission bandwidth of 4.25 nm. The intensity ratio of peaks at 339 nm to those at 334 nm from the excitation spectrum were plotted against the logarithm of copolymer concentration to measure the CMC. A plot of the intensity ratio of first to the third band from the emission spectrum of pyrene vs. logarithm of copolymer concentration was used to estimate micelle core polarity.
Example 9
Estimation of Core Viscosity by Fluorescent Probe Measurements
[0082] The viscosity of the micelle cores above the CMC was estimated with fluorescent probe techniques by measuring excimer to monomer intensity ratio (I e /I m ) of 1,3-(1,1=-dipyrenyl)propane at 376 and 480 n, respectively. 1,3-(1,1=-dipyrenyl)propane was dissolved in a known volume of chloroform to give a final concentration of 2H 10 โ7 M. Chloroform was then evaporated and replaced with 5 ml of aqueous solutions of polymeric micelles with a concentration of 500 ฮผg/ml or sodium lauryl sulfate at 5 mg/ml. Samples were heated at 65EC for an hour and cooled to room temperature overnight. A stream of nitrogen gas was used to deoxygenate samples prior to fluorescence measurements. Emission spectrum of 1,3-(1,1=-dipyrenyl)propane was obtained at room temperature using an excitation wavelength of 333 nm. Excitation bandwidth and integration times were set at the same values as the previous experiment.
Example 10
Statistical Analysis
[0083] Data obtained from CMC, micellar size, polarity and viscosity measurements were analyzed by Statistical Analysis Software (SAS) using either ANOVA, Duncan=s test or unpaired t test.
Example 11
Materials
[0084] Dicyclocarbodiimide (DCC), dimethylaminopyridine (DMAP), 6-aminohexanol, fatty acids and pyrene were purchased from Sigma Chemical Co., St. Louis, Mo. 2-hydroxypyridine (2-HP) and 2-aminoethanol were purchased from ICN. 1,3-(1,1=-dipyrenyl)propane was purchased from Molecular Probes, Eugene, Oreg. All other chemicals were reagent grade. PEO-block-poly(hydroxy-alkyl L-aspartamide block copolymers were obtained from K. Kataoka; they are described in U.S. Pat. No. 5,449,513; see also a description of the synthesis of PEO-b-PBLA block copolymers in Yokoyama et al. (1992) Bioconj. Chem. 3, 295.
[0085] Table 1. The effect of fatty acid chain length on micellar properties in PEO-b-PHAA polymer block length (12-15).
Substi- Fatty acid tution Size ยฑ CMC ยฑ Spacer chain level SD SD I 1 /I 3 ยฑ Ie/Im ยฑ group length (#C) (%) (nm) (mg/mL) SD SD ethyl โ6 44 16.4 ยฑ 39 ยฑ 5 1.05 ยฑ 0.16 ยฑ 3.2 0.01 0.01 ethyl 10 43 17.6 ยฑ 32 ยฑ 2 1.00 ยฑ 0.15 ยฑ 3.3 0.02 0.02 ethyl 14 42 17.7 ยฑ 34 ยฑ 16 1.03 ยฑ 0.15 ยฑ 3.9 0.02 0.01 ethyl 18 47 18.0 ยฑ 39 ยฑ 7 1.06 ยฑ 0.15 ยฑ 5.9 0.03 0.05 hexyl 10 57 18.1 ยฑ 26 ยฑ 3 1.01 ยฑ 0.12 ยฑ 3.3 0.03 0.01 hexyl 14 65 21.3 ยฑ 14 ยฑ 6 1.02 ยฑ 0.12 ยฑ 5.9 0.01 0.01 hexyl 18 60 21.6 ยฑ 23 ยฑ 5 1.02 ยฑ 0.15 ยฑ 3.4 0.01 0.04 hexyl 22 65 21.8 ยฑ โ9 ยฑ 2 1.08 ยฑ 0.08 ยฑ 7.4 0.01 0.01 hexyl 22 48 NA 27 ยฑ 4 1.03 ยฑ 0.12 ยฑ 0.01 0.01
[0086] [0086] TABLE 2 The effect of loading process on encapsulation of AmB by PEO-b- PHSA micelles. Initial AmB: PEO-b- level of Loaded PEO-b- Elution Loading PHSA AmB AmB PHSA Yield time method (mg) (mg) (mg) (mol:mol) (%) (min) Dialysis 20 406 244 0.25 60 10.8 Solvent 20 470 340 0.35 73 10.6 evaporation
[0087] Table 3. The effect of fatty acid substitution of the core-forming block on the encapsulation of AmB by PEO-b-PHSA micelles by solvent evaporation.
Stearic acid Initial substitution PEO-b- level of AmB: PEO-b- level PHSA AmB AmB PHSA Yield I/IV (%) (mg) (mg) (mg) (mol:mol) (%) ratio 11 20 470 240 0.22 51 2.2 โ50 b 20 470 340 0.35 73 Nd โ70 c 20 470 360 0.36 77 1.8 50 20 1870โ 992 0.89 53
[0088] Table 4. The effect of fatty acid substitution of the core-forming block on the in vitro antifungal activity of AmB encapsulated by PEO-b-PHSA micelles in comparison to AmB alone.
MIC โณ SD (mg/ml) AmB in: Loading method C. albicans C. neoformans A.fumigatus Saline โ 0.30 ยฑ 0.00 0.30 ยฑ 0.00 0.45 ยฑ 0.00 PEO-b-PHSA 11% Solvent evaporation 0.35 ยฑ 0.09 0.18 ยฑ 0.04 0.60 ยฑ 0.00 PEO-b-PHSA 50% Solvent evaporation 0.27 ยฑ 0.04 0.18 ยฑ 0.05 0.60 ยฑ 0.00 PEO-b-PHSA 70% Solvent evaporation 0.33 ยฑ 0.11 0.23 ยฑ 0.07 0.35 ยฑ 0.09 PEO-b-PHSA 50% Dialysis 0.71 ยฑ 0.19 0.25 ยฑ 0.09 0.82 ยฑ 0.38
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Provided are methods and compositions for reducing the toxicity of certain hydrophobic therapeutic agents, especially polyene antibiotics, in particular, Amphotericin B (AmB), and therapeutics such as paclitaxel, tamoxifen, an acylated prodrug or an acylated cis-platin, by incorporating these agents within micelles comprising an amphiphilic block-forming copolymer. Where the polyene is amphotericin B, desirably the spacer is an alkyl molecule of aabout 2 to about 8 carbon atoms, desirably 6 carbon atoms, and the core is an N-alkyl molecule of about 8 to about 28 carbon atoms, desirably 12 to 22 carbon atoms, advantageously, 12 to 18 carbon atoms, and as specifically embodied, 18 carbon atoms (stearate moiety). For the formulation of a larger polyene, the spacer and core are proportionately larger than those for amphotericin B. As specifically exemplified herein, the polymer backbone is a PEO of about 270 units with about 10-30 core-forming PLAA subunits, and advantageously about 14-24. Desirably the stearate moiety has a substitution level on the copolymer from about 35 percent to about 70 percent.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/555,595 filed on Mar. 23, 2004, the contents of which are hereby incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A โSEQUENCE LISTINGโ
[0003] Not applicable.
FIELD OF INVENTION
[0004] The present invention relates generally to breast enhancement aides and specifically to a breast enhancement method which is natural and non-invasive.
BACKGROUND OF THE INVENTION
[0005] Numerous instances exist where people desire enlargement of soft tissues in their bodies. One such instance is for the augmentation of physical attributes to improve cosmetics and self-esteem. These soft tissue enlargements are mainly directed at breast enlargements in females.
[0006] Prosthetic implants have been developed for insertion below the skin. However, the severity of the potential complications including scarring, implant rupture, capsular contracture, necrosis and implant migration as well as the recent adverse publicity thereof have significantly reduced the desirability of these implants. Thus, there is a societal need for other means to obtain soft tissue enlargement.
[0007] Moreover, the expense of surgery precludes many persons desiring to improve themselves from even considering it.
[0008] The prior art also describes the use of a vacuum to produce soft tissue enlargement. However, the prior art does not disclose a vacuum technique which would generally provide controlled tissue enlargement. Furthermore, it is well established that the application of an excessive amount of vacuum can result in damage to the soft tissue.
[0009] The above techniques have attempted to satisfy the demands of the public, but more often than not have left much to be desired or too much to be handled.
[0010] In light of the foregoing, non-invasive breast augmentation methods have been proposed. Hydro therapy, the use of external creams or internal hormone preparations, the use of foam pads have proved to be damaging, ineffective, to cause side effects and look unnatural and feel foreign.
[0011] Also, the use of herbal topical and oral compositions has been proposed but has proved to be unreliable since the human body will react differently from one person to another to a given composition, and some people prefer not to take any sort of supplementary pills.
[0012] In view of the foregoing disadvantages inherent in the known types of methods and systems now present in the prior art, the breast enhancement method according to the present invention substantially departs from the conventional methods and systems.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to provide an inexpensive, non-scarring, non-invasive method for breast augmentation which is all-natural and involves no drugs, topical or oral compositions, hormones or surgery and is self-administered.
[0014] Another object is to provide a breast enhancement method that enhances breast size by mimicking natural hormones and natural development processes.
[0015] Yet another object is to provide a breast enhancement method that improves an individual's quality of life and self-confidence.
[0016] In accordance with the present invention, a manipulative method is provided for enhancing breasts of a human, comprising the steps of stimulating breast lobules with fingertips; kneading the breasts; touching and rubbing the breasts' nipples; and massaging the breasts to direct milk flow to the breasts' areola and nipple areas.
[0017] In accordance with a further object of the present invention, a manipulative method is provided for enhancing breasts of a human, comprising the steps of stimulating breast lobules with fingertips in a repetitive 20-second manipulation of a breast area extending to about 50 contact points; kneading the breasts in a movement toward and away from the breasts' nipples for 5 to 10 minutes per breast; touching and rubbing said breasts' nipples; and massaging the breasts in large circles from the outer sections of the breasts towards the areola and nipple areas of said breasts to direct milk flow to said breasts' areola and nipple areas.
[0018] While the practical advantages and features of the present invention and method have been briefly described above, a greater understanding of the novel and unique features of the invention may be obtained by referring to the detailed description which follows.
DETAILED DESCRIPTION OF THE INVENTION
[0019] As stated hereinabove, the present invention provides a safe and effective method for enhancing breasts. The method helps to firm up and support the breasts through the filling up of glands which end up taking up more space in the breasts hence resulting in stretching and enlarging said breasts.
[0020] The method of the present invention is characterized by the following.
[0021] One should find a room or a place where one will be able to relax and feel comfortable and uninterrupted. One can do the exercise in one 30 to 40 minute sitting for both breasts or two 15 to 20 minute sittings, one for each breast. One can do these exercises on oneself or can even have someone else help.
[0022] To begin with, one should be in a comfortable and relaxed position lying down or sitting up. One can have some soft relaxing music playing to soothe mind and body. If one wishes to use some massage oil, it can be applied a little bit on the finger tips of your hand (optionalโto prevent skin irritation but is not necessary).
[0023] With three fingertips of the hand clumped together, one begins about two inches below the left collar bone and gently massages with the fingers in a tiny one inch circle for about 20 seconds. The massaging must be gentle. One must not dig into the breast and hurt oneself.
[0024] One is just trying to gently stimulate the lobules. Take the time to feel the skin under the fingers and breast tissue and muscle below it. One wants to stimulate each individual lobule with the fingertips to make sure one massages each little section completely. After about 20 seconds one moves the fingers clockwise to the spot right next to where one just massaged and does the same thing for another 20 seconds. One continues doing this by going all the way around clockwise under the arm, at the bottom of the breast, to the middle of the chest and back to below the collarbone. One will continue going clockwise and working closer to the nipple in smaller and smaller circles. One should do this on about 50 contact points on the breast and for about 20 seconds each.
[0025] It should take about 10 minutes. It is important to take the time to feel the texture of the breast.
[0026] For the first few times until the lobules begin to grow, this exercise can also make one aware of any lumps or abnormalities. If so, one should stop immediately and have it checked by a doctor.
[0027] Once one has completed this exercise, begin kneading the left breast with the right hand much like if one were kneading dough for making bread. Again paying special attention to try to contact all the lobules located in the breast tissue. One should knead and rub the breast going toward the nipple and away from the nipple. It should not hurt, if it does stop and try later. If it still hurts at a later time, stop doing it and contact a doctor. This should take between 5 and 10 minutes.
[0028] While you are doing this, it is also important that one gently touches and rubs the nipple. The first few times it will probably be sensitive but it will become less sensitive as time passes. Again, it should not hurt. If it does, stop and try later. If it continues to hurt contact a doctor. After a few weeks, as one continues this process, one will notice that the nipples and areola will also get larger as the breasts get larger.
[0029] Now do the same exercises with the right breast. As days pass, breasts and nipples will become less sensitive to the rubbing. One will notice the breasts beginning to feel slightly fuller. As one rubs the fingertips is small circles as in the first exercise and even when one kneads the breasts one will begin to feel the little lobules under the skin through the breast tissue. At this point, one knows that the breasts are beginning to change to be able to produce milk.
[0030] In the second week, after each time one has finished kneading, touching and rubbing the breasts' nipples, one will begin to gently massage the breast in large circles from the outer sections of the breast, to the areola and nipple. Beginning about 2 inches from the collarbone and making large circular motions working down to the areola. Now move the hand to where the arm and chest meet and make circular motions down to the areola. Move the hand to where the chest meets the armpit and do circular motions to the areola. One should continue doing this around the whole breast from the outer part of the breast to the areola for about 2 to 5 minutes, to try to direct the milk flow to the areola and nipple area. Behind the areola are pockets where milk will run into.
[0031] With the thumb and finger spread about 1ยฝ to 2 inches apart, one will gently place the thumb and finger on the outside of the areola and press them on the breast towards the chest. You will slowly begin to squeeze the fingers towards the nipple to try to squeeze milk out of the nipple. Do not squeeze the nipple itself because it will hurt and not accomplish anything.
[0032] Nothing will probably come out the first few times trying this procedure. By the end of the 2 nd or early in the 3 rd week one will notice a little bit of pasty discharge as one squeezes the areola out of the nipple. This is expected, because it is just clearing of the ducts. However, there should be no bleeding from the nipple. Since there are many ducts ending at the nipple one might see this discharge a couple of times.
[0033] After the bit of discharge is finished one will begin to notice just a drop or two of clear liquid which is colostrum. In the next few days one will notice a little more of this clear liquid come out of the breast when squeezed. After a week or so the liquid begins to change into a hazy white colour. Later on as the milk production increases, the milk will become whiter.
[0034] After the milk production is active, one has the choice to continue massaging and to extract the milk from each breast or just to continue stimulating the milk production every few days. One's body gets into a routine and will fill up with milk as per the routine that is chosen.
[0035] Every person is different so monitoring one's own situation is key. The fact that one should remember is that if one stops extracting the milk on a routine basis, the breasts will slowly stop producing it. If one decides not to do it anymore one can stop altogether or stop for a while and then restart over again at a later time. You can choose to increase the breast size a few weeks before a special occasion and then stop.
[0036] Some side effects may be associated to and result from the above described method but nothing out of the ordinary. They could include: tenderness or sensitivity in the breast and/or nipple due to the exercises/massages, tenderness or sensitivity in the breast and/or areola as the breast begins growing, muscle soreness due to some exercises, slight weight gain of approximately 5 to 10 pounds, and possibly slight leakage of milk from the breasts as the process advances.
[0037] With respect to the above described method then, it is to be realized that the optimum results will be achieved by conforming as closely as possible to the program provided and that, in any event, results may vary from one participant to another.
[0038] As a result of experiments utilizing the method of the present invention it has been recorded that if one were to stop the process, once restarting the process the results come faster. Chest measurements have also shown that the increase in size is consistent across the whole of the breast area.
[0039] Further, it would appear that the method may work faster if a partner is present and performing the massaging steps probably due to the fact that said partner would have better access to all areas of the breast for performing the method.
[0040] As for timeframes, it has been observed that a change in breast tissue texture would take place in the first week, followed by a slight size increase by the tenth day or so. A plateau is then reached between the second and third week, with continued increase after that.
[0041] Finally, no permanent side effects have been observed during or after the trials.
[0042] Other embodiments and uses of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The specification and examples should be considered exemplary only and do not limit the intended scope of the invention.
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A method for the enhancement of breasts is provided which is all natural and involves no drugs, topical or oral compositions, hormones or surgery and is self administered.
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FIELD OF THE INVENTION
This invention concerns an innovative section element in the form of a bar usable in particular, but nor exclusively, in making frames, supports, supporting structures and the like.
STATE OF THE TECHNIQUE
In making frames, supports, supporting structures and the like, both on a plane and three dimensional, at present tubular elements or even round cross section or polygonal cross section bars, mostly square are provided and used, with relative advantages and disadvantages that technicians working in the field are well acquainted with.
Usually, the tubular elements, that is the tubes for this use, are extruded, and joined when used in modular structures by means of linear, parallel, at an angle, T or three way, cross-shaped, etc. couplings or clamps, depending on the configuration of the structure to be made. The round cross-sectioned tubes do not require either constraints or limitations as regards to being fitted at an angle in the clamps or of the latter being fitted around the tubes. With polygonal cross-sectioned tubes on the other hand, the clamps have set positions, associated with the faces of each tube.
However, specific clamps are required for round tubes and other types of clamps for four-sided or polygonal tubes, in that the clamps for round tubes cannot be used for polygonal tubes, and vice versa. At the most, clamps for tubes with one cross-section shape are used in connecting the tubes with another cross-section shape, but with the use of and interposition of adaptors. In addition, for a possible combination of round tubes with square tubes for the same structure, clamps are required which have both a round and a square cross-section housing corresponding to the different tubes that require connecting.
Therefore it is evident, in the same way as for the composition of frames, supports and supporting structures according to the known technique, besides tubular elements with round and square cross-sections, there must be available at least two distinct series of clamps with different configurations that, also taking into consideration the various dimensions that tube cross-sections may have, implies making and having available, a large number of components that have a negative influence on tooling, construction and storing costs.
OBJECTS AND SUMMARY OF THE INVENTION
The main object of this invention is to create the conditions by which a single extruded section may be sufficient and be used indifferently both as a tube or bar having a circular cross-section and as a tube o bar having a square, that is polygonal, cross-section, along any part of its length.
Another object of the invention is to provide a section element of aluminium or similar for forming frames, supports, etc, in which the characteristics of the round tubes and the square or polygonal tubes or bars with respective advantages are combined together and integrated.
Still another object of the invention is to provide a multivalent section element suitable to be combined with and connected both to other similar sections and with round tubes by the same type of connecting clamps.
Another object of the invention is to provide a section element which can be combined also with traditional round and square tubes by means of the usual clamps available on the market having compatible sizes.
Yet another object of the invention is to propose linear, at an angle, three-way, cruciform, etc. clamps, suitable for coupling both with the round and square, that is polygonal, component of the section element without limitations as regards to angular position when associated with the round component and with preset orientation when associated with square or polygonal component.
These object and implicit advantages which follow are achieved, according to the invention, with a section element characterized by a body having peripherally one or more flat surfaces and for the rest one or more circular sectors as part of a circumference, and in line with each flat surface a longitudinal groove with parallel borders forming undercuts, and wherein connecting clamps are associable to said section element, each forming at least one cylindrical housing having a diameter corresponding to that of a cylindrical surface formed by the circular sectors of the section body and at least an additional means of centring designed to engage the groove along at least one of said flat surfaces.
The flat surfaces of the section element can be advantageously, but not exclusively, four in number; correspondingly there will be four circular sectors, alternating with the flat surface. Thus, said flat surfaces correspond to the same number of parts of the sides of a square prism for a use of the section element such as a tube or bar having a square cross-section, whereas the rounded sectors correspond to the same number of parts of a cylindrical surface for a use of the section element like a round bar or tube, the flat surfaces resulting inside the cylindrical surface formed by the rounded sectors.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will however be illustrated more in detail in the continuation of this description made with reference to the enclosed indicative and not limiting drawings, in which:
FIG. 1 shows a view of a bar section in perspective according to the invention;
FIG. 2 shows an end view thereof;
FIG. 3 shows an exploded view of a clamp for connecting a bar section to another one;
FIG. 4 shows two bar sections assembled with the clamp in FIG. 3 ;
FIG. 5 shows a side view of the group in FIG. 4 ;
FIG. 6 shows an exploded view of a pair of clamps for joining two octagonal bar sections;
FIGS. 7 and 8 show the pair of clamps in FIG. 6 before and after connection of the two octagonal bar sections;
FIG. 9 shows a side view of the group in FIG. 8 ;
FIG. 10 shows an exploded view of a pair of clamps for connecting two parallel bar sections;
FIGS. 11 and 12 show the pair of clamps in FIG. 10 before and after connecting the two parallel bar sections;
FIG. 13 shows a side view of the group in FIG. 12 ;
FIG. 14 shows a tie type clamp; and
FIG. 15 shows an example of a use of the clamp in FIG. 14 for connecting the two elements.
DETAILED DESCRIPTION OF THE INVENTION
As shown, the section element of the invention includes a section body 10 with a prevalent length dimension and having, peripherally, in cross sections, one or more flat surfaces 11 , the remainder of the surface sectors being round 12 .
The section body 10 can be made by extruding aluminium or its alloys of preference with four flat surfaces 11 that alternate with an equal number of rounded sectors 12 . In the section body seen as a whole, the flat surfaces 111 form parts of the sides of a square prism B, the rounded sectors 12 join the flat surfaces and correspond to parts of a cylindrical surface A with a preset diameter D, and the flat surfaces 11 are on the inner side of the circumference of said cylindrical surfaceโ FIGS. 1 and 2 .
A groove 13 is cut along each flat surface 11 with an opening formed by two parallel borders 14 defining internally, from opposite sides of the groove, two corresponding undercuts 15 the surface of which can be longitudinally grooved.
The section element 10 shaped in this way can be connected to other similar elements in various ways and even to conventional round and square tubes, by means of usual clamps for round or square tubes. The rounded sectors 12 define round outer surface engagement means for engagement by a round engagement part (e.g., a usual clamp for round tubes). The flat surfaces 11 define polygon outer surface engagement means for engagement by a polygonal engagement part (e.g., a usual clamp for square tubes).
But advantageously, this invention proposes a clamp 16 which can have different configurations, linear, at an angle, T, etc. and which is set up to connect up both to flat surfaces and to the cylindrical sectors of the section body 10 .
The clamp 16 comprises a first block 17 and a second block 18 which overlap and lock together by means of a series of bolts 19 and nuts 20 engaging coincident bores 17 โฒ, 18 โฒ machined respectively in the two blocks.
The first block 17 has a flat base 21 and forms a substantially semi-cylindrical notch 22 that extends in length between two opposite sides of the block itself and that is open towards the second block 18 . This second block delimits in its turn a substantially semi-cylindrical notch 23 , facing towards the notch 22 of the first block to form with it, when the clamp 16 is assembled, a cylindrical housing the diameter D of which is compatible with the cylindrical sectors 12 of the section body 10 .
At least in the first block 17 , on opposite sides of its semi-cylindrical notch 22 , two recesses 24 are provided and in correspondence with each recess there is a bore 25 perpendicular to the flat surface 21 of the block itself. The bores 25 in said recesses 24 are provided to host bolts 26 to fix the clamp directly to any flat surface 11 of the section body 10 with the help of threaded anchoring elements 27 placed in the groove 13 running along a surface and engaging with the undercuts on the walls of said groove 13 . The anchoring elements 27 can be the same shape as the so-called hammer nuts or plates with a threaded hole in which to thread the bolts 26 .
On the bottom of the semi-cylindrical notch 22 at least in the first block 17 of the clamp, a centring member 28 is located, which is overhanging and designed to engage the opening of any groove 13 with the function of preventing the clamp from turning on the body section it is associated with and acting as a guide for the linear movement and positioning of the clamp along the flat surfaces 11 of said section body.
The centring member 28 can, for example, be in the shape of a key as shown in the drawing, it is applied in the semi-cylindrical notch and it can be removed to be used only when required. In order to be removed when needed, the centring device 28 can be provided with pins 29 which fit unto corresponding holes 30 provided in the bottom of the respective semi-cylindrical notch 22 .
A similar centring member 31 can be associated in the same way and with the same functions to the semi-cylindrical notch 23 of the second block 18 of the clamp, said centring member 31 being provided with pins 32 designed to engage in holes 33 machined in the bottom of said notch 23 .
The clamp 16 , on its own or connected to others, enables the connection of the section body 10 with other similar sections, using each time their flat surfaces, that is the prismatic part, or their cylindrical section.
In fact, a clamp 16 can be fixed on any flat surface 11 of the section body 10 and used to block another section body 10 in the housing formed by the respective blocks 17 , 18 . In this way, the first block 17 is fixed to a groove 13 of a flat surface 11 of the section 10 by inserting bolts 26 in the bores 25 in the bottom of recesses 24 in the walls of the semi-cylindrical recess 22 of said block and engaging with the anchoring elements 27 that are provided in said groove and which engage the undercuts 15 inside the latterโ FIGS. 4 and 5 . Then, between the first block 17 and the second block 18 of the same clamp 16 there can be a second section body 10 placed and held in position. This other section body can be blocked by connecting the blocks of the clamp 17 , 18 together, by using a set of nuts and bolts 20 , 19 so as to tighten them around the cylindrical sector of the second section body without using the centring members 28 , 31 . In this case, the section, before blocking it, can be turned at an angle as required on its longitudinal axis.
By applying the centring members 28 , 31 on the bottom of the semi-cylindrical notches 22 , 23 of the clam blocks 17 , 18 , the section element may on the other hand be blocked in the clamp according to a set angle and corresponding to the flat surfaces 11 . Consequently, in fact, the centring members engage the section element in the respective grooves 13 , stopping it from turning.
It is also possible to pair the clamps 16 to join two sections 10 using a cross formationโFIGS. 6 - 9 โor parallelโFIGS. 10 - 13 โeach held and blocked in the cylindrical housing by a respective clamp, with or without centring members 28 , 31 . The clamps are paired by resting the base 21 of the first block 17 of one clamp to the base 17 of the first block 21 of the other clamp and fixing all the blocks of both clamps together using suitable length bolts 19 โฒ to tighten the sections 10 together.
By using a C clamp that is a tie clamp 34 as shown in FIG. 14 it will also be possible to block two elements 35 , 36 independently, e.g. two tubes or sections together or a tube or section with a tool or another device as shown in the example in FIG. 15 , with the possibility of turning or directing an element differently from the other. The example of FIG. 15 uses an alternate clamp 16 โฒ.
For this purpose, the tie clamp has two protruding tabs 37 each having a pair of bores 38 coinciding with the ones in the other to receive crossways, two blocking screws 39 , 40 , The internal face of each tab 37 has two planes 41 , 42 inclined in opposite directions which converge in an apex, resulting between the pair of bores and acting as an intermediate fulcrum 43 . Externally each tab has a groove 44 which facilitate flexibility when the tabs are engaged crossways by screws 39 , 40 .
Practically, the tie clamp 34 is connected by a first screw 39 to a first element 35 and by another screw 40 to another element 36 to be associated with the first. Thanks to the intermediate fulcrum 43 , by fully tightening the first screw 39 and not the other screw 40 the clamp can be firmly blocked to the first element 35 , leaving the second element 36 loose so that it can be turned and/or moved axially in the clamp. On the contrary, by fully tightening the second screw 40 and not the first one 39 , it is possible to firmly block the second element 36 in the clamp and move the latter with respect to the first element 35 to which it is connected by said first screw. By firmly tightening both screws 39 , 40 it will be possible to rigidly block the first and second elements without the possibility of moving one with respect to the other.
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A section element for constructing frames, supporting structures and the like made up of a section body ( 10 ) having one or more flat surfaces ( 11 ) and one or more rounded sectors ( 12 ) as parts of a circumference with a preset diameter. In correspondence with each flat surface ( 11 ) a longitudinal groove ( 13 ) is provided with parallel borders defining undercuts ( 15 ). The section body can be connected to other elements by means of clamps ( 16 ) each one delimiting at least one cylindrical in diameter housing matching that of the cylindrical surface defined by the rounded sectors of the section body and having at least one additional centering member designed to fit in the groove along at least one of the flat surfaces.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to semiconductor processing and, more particularly, to a method of forming layers of sidewall spacers upon a gate conductor to produce a graded junction which minimizes hot-carrier effects.
2. Description of Relevant Art
Fabrication of a metal-oxide-semiconductor ("MOS") transistor is well-known. Fabrication begins by lightly doping a single crystal silicon substrate n-type or p-type. The specific area where the transistor will be formed is then isolated from other areas on the substrate using various isolation structures. In modem fabrication technologies, the isolation structures may comprise shallow trenches in the substrate filled with dielectric oxide which acts as an insulator. Isolation structures may alternatively comprise, for example, locally oxidized silicon ("LOCOS") structures. A gate dielectric is then formed by oxidizing the silicon substrate. Oxidation is generally performed in a thermal oxidation furnace or, alternatively, in a rapid-thermal-anneal ("RTA") apparatus. A gate conductor is then patterned from a layer of polycrystalline silicon ("polysilicon") deposited upon the gate dielectric. The polysilicon is rendered conductive by doping it with ions from an implanter or a diffusion furnace. The gate conductor is patterned using a mask followed by exposure, development, and etching. Subsequently, source and drain regions are doped, via ion implantation, with a high dosage n-type or p-type dopant. If the source and drain regions are doped n-type, the transistor is referred to as NMOS, and if the source and drain regions are doped p-type, the transistor is referred to as PMOS. A channel region between the source and the drain is protected from the implant species by the pre-existing gate conductor. When voltage above a certain threshold is applied to the gate of an enhancement-mode transistor, the channel between the source and drain becomes conductive and the transistor turns on.
FIG. 1 shows a top view of such a transistor. The transistor is formed in active region 26 of semiconductor substrate 10, between isolation areas 18 and 20. Isolation areas 18 and 20 preferably comprise shallow trench isolation structures filled with a dielectric oxide. A polysilicon layer is deposited upon the semiconductor topography and then patterned to form gate conductor 22. N-type or p-type species are implanted into the semiconductor substrate to form source region 26, drain region 28, and to render the polysilicon layer conductive. An interlevel dielectric is then deposited upon the semiconductor topography (not shown) to electrically isolate the underlying transistor from the overlying metal layers. Contact holes are etched into the interlevel dielectric and then metal is deposited into the holes to establish electrical contacts. Structures 42, 44, and 46 are such electrical contacts. Electrical contact 42 is described in more detail in subsequent cross-sectional views along plane A.
FIG. 2 is a partial cross-sectional view along plane A of semiconductor substrate 10. Isolation structure 18 is shown as a shallow trench isolation structure. Gate conductor 22 is shown terminating over and above isolation structure 18. Conformal oxide layer 30 is then deposited upon the semiconductor topography preferably using a CVD process. Oxide layer 30 is then etched using an anisotropic plasma etch. An anisotropic etch removes the oxide from substantially horizontal surfaces faster than oxide from substantially vertical surfaces. The anisotropic etch thereby leaves spacers 32 and 34 on the vertical sidewall surfaces of gate conductor 22. Spacer structures 32 and 34 are typically formed for two reasons: (i) to be used in forming a lightly doped drain ("LDD") structure, and (ii) to be used in aligning silicide areas on the source, drain, and gate conductor.
FIG. 3 is a processing step subsequent to FIG. 2 in which an interlevel dielectric 36 is deposited across the semiconductor topography. Interlevel dielectric 36 is deposited to electrically isolate the underlying gate conductors and source and drain regions from the subsequently formed, overlying metal interconnect. Interlevel dielectric 36 typically comprises glass deposited using a spin-on process or chemical vapor deposition. Boron and phosphorus may be incorporated into the glass during the deposition to reduce stress in the glass, improve step coverage, and to enable the dielectric to flow at lower temperatures. After initial deposition, the upper surface of interlevel dielectric 36 follows the contour of the underlying structure. The wafer is then heated, typically at a temperature of approximately 800ยฐ C., and interlevel dielectric 36 flows to fill in existing gaps and produce a more planar upper surface.
FIG. 4 is a processing step subsequent to FIG. 3 in which a photoresist layer is deposited upon interlevel dielectric 36 and then patterned to expose portion 38 of the upper surface of interlevel dielectric 36. A hole is subsequently etched through interlevel dielectric 36. An anisotropic etch is typically used which combines physical and chemical etching. This produces a hole with substantially vertical sidewalls. The chemical part of the etch is selected so as to be selective to oxide. Since spacer 34 comprises silicon dioxide, it is also attacked by the etchant and may also be removed during the etch process. In that case, the etchant will reach the trench dielectric fill which also typically comprises some form of oxide. As a result, since all these materials have very similar responsiveness to the etch, the etch may go completely through the isolation material f18 to silicon substrate 10. Etches are usually stopped by the presence of a material with dissimilar etch characteristics. When such a material is detected, a signal is sent and the etch stops. In this case, since all the materials present have similar etch characteristics, it is difficult at best to determine etch end point. The result shown in FIG. 4 indicates removal of an oxide spacer; however, a spacer of dissimilar material (i.e., nitride or polysilicon) would not be removed.
FIG. 5 is a processing step subsequent to FIG. 4 in which a metal 44 is deposited into contact 42 opening for the establishment of an electrical connection. Metals like aluminum or tungsten are typically used. Chemical-mechanical polishing ("CMP") is applied to the wafer to remove any metal exterior to the hole and planarize the top surface. After the CMP, upper surface of metal 44 is at the same vertical level as upper surface of interlevel dielectric 36. Metal 44 is deposited to electrically connect the gate conductor to the source and both of them to an overlying metal interconnect line. The gate conductor is shorted to the source so that the transistor emulates a diode. If the previous etch has attacked the trench dielectric so that a hole exists into the underlying silicon, an undesirable electrical short will also be established between semiconductor substrate 10, gate conductor 22 and the source of the transistor. It would therefore be desirable to prevent the etchant from attacking the underlying trench dielectric. This will prevent metal from being deposited upon the exposed substrate silicon and establishing an electrical short.
Spacers 32 and 34 serve to reduce the maximum electric field E m which exists near the drain side of the channel area. Although not shown in FIGS. 2-5, the channel area exists along plane B of FIG. 1. The spacers occur not only in the active regions but also on all sidewall surfaces associated with the gate conductors. Absent spacers, an inversion-layer charges (or carriers) are accelerated into the overlying gate oxide. The carriers become trapped in the gate dielectric, a phenomenon generally called the hot-carrier effect. The injection of hot carriers into the gate dielectric damages the substrate/gate dielectric interface. Over time, operational characteristics of the device may degrade due to this damage, that degradation resulting in, e.g., improper variation of threshold voltage, linear region transconductance, subthreshold slope, and saturation current. This may eventually reduce the lifetime of the devices. Spacers 32 and 34 reduce E m by minimizing the abruptness in voltage changes near the drain side of the channel. Disbursing abrupt voltage changes reduces E m strength and the harmful hot-carrier effects resulting therefrom.
Reducing E m occurs by replacing an abrupt drain doping profile with a more gradually varying doping profile. A more gradual doping profile distributes E m along a larger lateral distance so that the voltage drop is shared by the channel and the drain. Absent a gradual doping profile, an abrupt junction can exist where almost all of the voltage drop occurs across the lightly-doped channel. The smoother the doping profile, the smaller E m is.
The simplest method to obtain a gradual doping at the drain-side channel is to use a dopant with a high diffusivity, for example, phosphorus instead of arsenic for an n-channel device. The faster-diffusing phosphorus readily migrates from its implant position in the drain toward the channel creating a gradually doped drain and consequently a smoother voltage profile. Unfortunately, however, the high diffusivity of phosphorus, in addition to creating a gradual lateral doping profile, also increases the lateral and vertical extents of the junction. Enlarging the junctions may bring about harmful short-channel effects and/or parasitic capacitances. Short-channel effects may result in less well-predicted threshold voltage, larger subthreshold currents, and altered I-V characteristics.
The most widely-used device structure for achieving a doping gradient at the drain-side of channel is through use of spacers such as spacers 32 and 34. Spacers bring about formation of a lightly-doped drain ("LDD") structure. An LDD structure is made by a two-step implant process. The first step takes place after the formation of the gate. For an n-channel device, a relatively light implant of phosphorus is used to form the lightly doped region adjacent the channel (i.e., the LDD implant). The LDD implants are also referred to as N - and P - implants because of their lower concentrations. A conformal CVD oxide film is then deposited over the LDD implant and interposed gate. The oxide is then anisotropically removed, leaving spacers immediately adjacent sidewall surfaces of the gate conductor. After the spacers are formed, a second implant takes place at a higher dosage than the first implant. The second implant is chosen to use the same implant "type" (i.e., n or p) as the first. The higher concentration source/drain implants are also referred to as N + and P + implants. The source/drain implant is masked from areas adjacent the gate by virtue of the pre-existing spacers. Using an n-type example, the first implant (LDD implant) may use phosphorus, while the second implant (source/drain implant) uses arsenic. The spacers serve to mask the arsenic and to offset it from the gate edges. By introducing spacers after the LDD implant, the LDD structure offers a great deal of flexibility in doping the LDD area relative to the source/drain area. The LDD area is controlled by the lateral spacer dimension and the thermal drive cycle, and is made independent from the source and drain implant (second implant) depth. The conventional LDD process, however, sacrifices some device performance to improve hot-carrier resistance. For example, the LDD process exhibits reduced drive current under comparable gate and source voltages.
A thermal anneal step is required after ion implantation in order to diffuse and activate the implanted ions and repair possible implant damage to the crystal structure. An anneal can occur in a furnace or the more modern rapid-thermal-anneal ("RTA") chamber. An RTA process is typically performed at 420ยฐ-1150ยฐ C. and lasts anywhere from a few seconds to a few minutes. Large area incoherent energy sources were developed to ensure uniform heating of the wafers and to avoid warpage. These sources emit radiant light which allows very rapid and uniform heating and cooling. Wafers are thermally isolated so that radiant (not conductive) heating and cooling is dominant. Various heat sources are utilized, including arc lamps, tungsten-halogen lamps, and resistively-heated slotted graphite sheets. Most heating is performed in inert atmospheres (argon or nitrogen) or vacuum, although oxygen or ammonia for growth of silicon dioxide and silicon nitride may be introduced into the RTA chamber.
The temperature and time required for an RTA are tailored to the implant type and to the implant's purpose. Dopants with a low diffusivity require higher anneal temperatures to activate and position the dopants. Dopants with a high diffusivity require lower anneal temperatures. In addition, a higher concentration of the dopants requires higher anneal temperatures. The dopants used for the LDD implants require lower temperature anneals since any additional migration of these dopants is especially harmful. Any migration towards the channel will contribute to short-channel effects and any vertical migration will increase the parasitic capacitance. In a conventional LDD, the LDD implants are performed first and any subsequent thermal anneal to activate and diffuse the subsequent source/drain implants will also thermally affect the LDD implants. A process would be desirable that could reverse the LDD formation process and enable the performance of the high-temperature thermal anneals first. This would allow a lower temperature anneal for the LDD implant which would not induce excessive migration of the dopants.
SUMMARY OF THE INVENTION
The problems outlined above are in large part solved by a transistor and a transistor fabrication method hereof. The present structure and method includes a sequence of spacers formed upon sidewall surfaces of the gate conductor to produce a graded junction having a relatively smooth doping profile. At least two such spacers are layered upon the sidewall surfaces. The spacers preferably comprise materials with dissimilar etch characteristics. Dopants are implanted into the semiconductor substrate after each spacer is formed upon the gate conductor. Each dopant is implanted with a higher energy and a higher dosage. As a result a graded junction is created having higher concentration regions formed outside of lightly concentration regions, relative to the channel area. Such a doping profile provides superior protection against the hot-carrier effect compared to the traditional LDD structure. In traditional LDD structure only one such spacer is typically used and only two different dopant concentrations exist in the source/drain junction. The smoother the doping profile, the more gradual the voltage drop across the channel/drain junction. A more gradual voltage drop gives rise to a smaller electric field and reduces the hot-carrier effect.
According to a second embodiment, the graded junction may be formed in reverse order. Adjacent spacers are formed from materials with dissimilar etch characteristics and, therefore, may be removed sequentially. This can be accomplished by using an etchant with the appropriate selectivity for each spacer layer. Dopants are implanted into the semiconductor substrate after each spacer has been removed. Each dopant is implanted with a lower energy and lower dosage. As a result a similar graded junction is again formed. Forming the junction in reverse order allows high-temperature thermal anneals to be performed first, followed by lower temperature anneals second. The high-temperature thermal anneals are required to activate the high-concentration source/drain implants which are the furthest away from the channel. LDD implants closest to the channel require a lower temperature thermal anneal. If the LDD implants migrate excessively, the channel will be shortened which can give rise to harmful short-channel effects. Performing the implants in reverse order avoids exposing the LDD implants to high temperature cycles which would give rise to excessive migration.
In a first embodiment, a semiconductor topography is provided upon which a gate conductor is formed having opposed sidewall surfaces. At least two dielectric layers, having dissimilar etch characteristics, are then formed in sequence upon the sidewall surfaces of the gate conductor. The layers may comprise an oxide layer interposed between a pair of nitride layers, or an oxide layer interposed between a pair of polysilicon layers, or a nitride layer interposed between a layer of thermally grown oxide and a chemical vapor deposited oxide, or a polysilicon layer interposed between a thermally grown oxide and a chemical vapor deposited oxide. Each layer is deposited across the gate conductor and then anisotropically removed from the horizontal surfaces of the semiconductor topography and the gate conductor. A dopant is implanted into the semiconductor topography after at least one dielectric layer is formed. The dopants are implanted into the semiconductor topography a spaced distance from the sidewall surface of the gate conductor defined by a thickness of at least one of the dielectric layers. Furthermore, the dopants are implanted into the semiconductor topography a spaced distance which increases from the sidewall surface in accordance with a layer added to the sequence of dielectric layers. In an alternative embodiment, dopants are implanted into the semiconductor topography after each dielectric layer is formed.
In a second embodiment, a semiconductor topography is provided upon which a gate conductor is formed having opposed sidewall surfaces. At least two dielectric layers, having dissimilar etch characteristics, are then formed in sequence upon the sidewall surfaces of the gate conductor. Similar to the spacers in the first embodiment, the spacers are layered such that a dielectric is interposed between a pair of dielectric of equal or dissimilar chemical compositions bearing dissimilar etch characteristics. Each layer is deposited across the gate conductor and then predominantly removed from the horizontal surfaces of the semiconductor topography and the gate conductor. Each layer in the sequence, having dissimilar etch characteristics from an adjacent layer within the sequence, is then removed using a selective etch. A dopant is implanted into the semiconductor topography after at least one dielectric layer is removed, or after removal of each layer. The dopants are implanted into the semiconductor topography a spaced distance from the sidewall surface of the gate conductor defined by a thickness of at least one of the dielectric layers. Furthermore, the dopants are implanted into the semiconductor topography a spaced distance which decreases from the sidewall surface in accordance with a layer removed from the sequence of dielectric layers.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the accompanying drawings in which:
FIG. 1 is a partial plan view of an integrated circuit comprising a typical transistor formed in an active region of a semiconductor substrate with metal contacts and a polysilicon gate conductor;
FIG. 2 is a partial cross-sectional view along plane A of FIG. 1 illustrating a semiconductor topography having spacers formed on the sidewall surfaces of a gate conductor;
FIG. 3 is a partial cross-sectional view of the semiconductor topography according a processing step subsequent to FIG. 2, wherein interlevel dielectric is formed upon the semiconductor topography;
FIG. 4 is a partial cross-sectional view of the semiconductor topography according to a processing step subsequent to FIG. 3, wherein a contact is formed through the interlevel dielectric;
FIG. 5 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 4, wherein metal is deposited into the contact opening in order to establish electrical contact with the underlying gate and source junction;
FIG. 6 is a partial cross-sectional view of a semiconductor topography along plane B of FIG. 1, wherein the integrated circuit is shown according to an early processing step of a first embodiment of the present invention in order to indicate a first concentration of dopants implanted into the semiconductor substrate to form a first implant area (LDD area) and an oxide etch-stop layer is thermally grown upon the gate conductor and upon the first implant area;
FIG. 7 is a partial cross-sectional view of the semiconductor topography according to a processing step subsequent to FIG. 6, wherein a first pair of spacers is formed upon the sidewall surfaces of the gate conductor;
FIG. 8 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 7, wherein a second concentration of dopants is implanted into the semiconductor substrate to form a second implant area;
FIG. 9 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 8, wherein a layer of oxide is formed upon the gate conductor and first pair of nitride spacers;
FIG. 10 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 9, wherein a third concentration of dopants is implanted into the semiconductor substrate to form a third implant area;
FIG. 11 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 10, wherein a second pair of spacers is formed upon the sidewall surfaces of the gate conductor immediately adjacent the previously placed oxide;
FIG. 12 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 11, wherein a fourth concentration of dopants is implanted into the semiconductor substrate to form a fourth implant area;
FIG. 13 is a partial cross-sectional view of a semiconductor topography according to a second embodiment of the invention in which all the spacer layers have been formed but no dopants have been implanted into the semiconductor substrate and in which a first concentration of dopants is implanted into the semiconductor substrate to form a fourth implant area;
FIG. 14 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 13, wherein a pair of spacers is removed from the sidewall surfaces of the gate conductor followed by implantation of a second concentration of dopants into the semiconductor substrate to form a third implant area;
FIG. 15 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 14, wherein a layer of oxide is removed from the sidewall surfaces of the gate conductor followed by implantation of a third concentration of dopants into the semiconductor substrate to form a third implant area;
FIG. 16 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 15, wherein a pair of spacers is removed from the sidewall surfaces of the gate conductor followed by implantation of a fourth concentration of dopants into the semiconductor substrate to form a second implant area (LDD area); and
FIG. 17 is a partial cross-sectional view of a semiconductor topography according to a processing step subsequent to FIG. 16, wherein a silicide is formed upon the gate conductor and source/drain areas.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, FIGS. 6-12 are used to describe the present invention according to a first embodiment and FIGS. 12-17 are used to describe the present invention according to a second embodiment.
FIG. 6 depicts a semiconductor substrate 110 which preferably comprises lightly doped n-type or p-type single-crystalline silicon having a relatively low resistivity of, e.g., 12 ohms-cm. A polysilicon layer is deposited upon a gate dielectric (not shown) a dielectric spaced distance over a semiconductor substrate. The polysilicon layer is then patterned to form gate conductor 114 with an upper surface 118 and sidewall surfaces 116 and 120. The polysilicon layer may be deposited using a low pressure CVD process. A first concentration of dopants is implanted into semiconductor substrate 110 to form a first implant area within the junctions of the ensuing transistor. The first implant area is henceforth referred to as LDD regions 122 and 124. LDD implants 122 and 124 are substantially adjacent to gate conductor 114 and, more specifically, adjacent to channel area 129 underneath gate conductor 114.
If an NMOS transistor is to be formed, phosphorus is preferably used as the LDD implant. If a PMOS transistor is to be formed, boron is preferably used. Thermal anneal 126 may thereafter be performed to activate the LDD implants and to thermally grow oxide layer 128. Oxide layer 128 is grown upon semiconductor substrate 110, upon upper surface 118 of gate conductor 114, and upon sidewall surfaces 116 and 120 of gate conductor 114 by oxidizing the silicon in those areas. Oxide layer 128 is to act as an etch stop during subsequent formation and removal of a spacer material set forth below. The spacer is preferably nitride and, since nitride and oxide have different etch characteristics, the spacer can be formed and removed separate from the underlying oxide.
Turning now to FIG. 7, a step subsequent to FIG. 6 is shown in which a spacer material (preferably nitride, or possibly polysilicon) is deposited upon the semiconductor topography to form conformal layer 134. Layer 134 is then anisotropically etched, preferably using a plasma etch process, until nitride layer 134 is cleared from the horizontal planar regions of oxide layer 128. By using an anisotropic etch and minimizing the overetch, nitride spacer structures 136 and 138 are formed upon exterior sidewall surfaces of oxide layer 128. Nitride spacers extend a horizontal distance d 1 from opposing sidewall surfaces 116 and 120 of gate conductor 114, respectively.
FIG. 8 illustrates a second concentration of dopants 140 implanted into semiconductor substrate 110 to form second implant regions 142 and 144 within the junctions. If an NMOS transistor is to be formed, phosphorus or arsenic is preferably used as the implant. If a PMOS transistor is to be formed, boron is preferably used. Second dopant concentration is greater than first dopant concentration. In addition, higher implant energies are used for the second implant so as to implant the dopants deeper into semiconductor substrate 110 as compared with the previous LDI) implants. Dopants 140 are implanted into semiconductor substrate 1 10 a spaced distance d 1 from sidewall surfaces 116 and 120 due to masking incurred by nitride spacers 136 and 138.
FIG. 9 depicts an oxide layer 146 deposited upon the semiconductor topography. Oxide layer 128 is preferably deposited using a CVD process. If desired, an anisotropic etch may be used to remove the oxide from substantially horizontal surfaces. Resulting from deposition and possible etch, oxide layer 146 is formed above gate conductor 114 and immediately adjacent spacers 136 and 138 as oxide spacers 148 and 150. Oxide spacers extend a horizontal distance d 2 from sidewall surfaces 116 and 120 respectively. Distance d 2 is greater than distance d 1 .
FIG. 10 indicates a third concentration of dopants 152 implanted into semiconductor substrate 110 to form third implant areas 154 and 156. Dopants 152 are of the same species as those used to form the first and second implant areas. Third dopant concentration is greater than second dopant concentration. In addition, higher implant energies are used for the third implant so as to implant the dopants deeper into semiconductor substrate 110 as compared with the previous source/drain implants in areas 142 and 144. Dopants 152 are implanted into semiconductor substrate 110 a spaced distance d 2 from sidewall surfaces 116 and 120 due to masking incurred by oxide spacers 148 and 150.
FIG. 11 illustrates another spacer formed from a conformal layer 158. Layer 158 is anisotropically etched, preferably using a plasma etch process, until layer 158 is cleared from the substantially horizontal planar regions of oxide layer 128 and oxide layer 146. By using an anisotropic etch and minimizing the overetch, spacer structures 160 and 162 are formed upon exterior sidewall surfaces of oxide spacers 148 and 150. The spacers are preferably nitride or polysilicon, which extend a horizontal distance d 3 from opposing sidewall surfaces 116 and 120 of gate conductor 114, respectively. If the spacers are nitride, no silicide will form upon the spacers during subsequent silicide formation (not shown). Silicide formation is inhibited by the presence of silicon dioxide or nitride (i.e., silicon nitride). As an alternative, nitride which forms spacers 160 and 162 may include oxide, as nitrogenated oxide or oxynitride.
FIG. 12 illustrates a fourth concentration of dopants 164 is implanted into semiconductor substrate 110 to form fourth implant areas 166 and 168. If an NMOS transistor is to be formed, phosphorus or arsenic is preferably used as the implant. If a PMOS transistor is to be formed, boron is preferably used. Fourth dopant concentration is greater than third dopant concentration. In addition, higher implant energies are used for the fourth implant so as to implant the dopants deeper into semiconductor substrate 110 as compared with the previous source/drain implants in areas 154 and 156. Dopants 164 are implanted into semiconductor substrate 110 a spaced distance d 3 from sidewall surfaces 116 and 120 due to masking incurred by nitride spacers 160 and 162. Thermal anneal 170 is then performed to activate the source/drain implants. In a preferred embodiment, thermal anneal 170 is performed in an RTA chamber. An RTA process uses large area incoherent heat sources to quickly heat the semiconductor substrate without transferring excessive amounts of heat to the substrate.
As already stated above, in a preferred embodiment, three layers of spacers are formed and the sequence of spacer formation is nitride/oxide/nitride. In alternative embodiments, the sequence of spacers may comprise polysilicon/oxide/polysilicon, or thermally grown oxide/nitride/CVD oxide, or thermally grown oxide/polysilicon/CVD oxide. Adjacent spacer layers must have dissimilar etch characteristics so that they can be selectively removed one at a time.
The above process describes the formation of a graded junction. The dopant concentration is low at the edge of the junction close to the channel and increases as the distance from the channel increases. A greater number of implant areas within the junction with different dopant concentrations results in an ultra-smooth doping profile. The ultra-smooth doping profile is superior in combating the hot-carrier effects than the traditional LDD doping profile. Hot-carrier effects are due to large electric fields at the channel/drain junction. A smoother doping profile produces a smoother voltage drop at the channel/drain junction and results in reduced electric fields. The present drawings illustrate up to four implant areas; however, it is understood that anywhere from greater than three areas to more than four would suffice depending upon the amount of profile smoothing needed. Of course, each implant requires a corresponding masking edge brought about by a separate and unique spacer structure.
According to a second embodiment, the ion implantation may be performed in reverse order. All the spacers are first formed in the same sequence as in the first embodiment. However, none of the implants are performed following spacer formation. Instead, the ion implants are performed as the spacers are removed. FIGS. 13-17 show the process of spacer removal followed by ion implantation.
Turning now to FIG. 13, a step subsequent to FIG. 12 is shown. However, none of the implants have been performed yet. A fourth concentration of dopants 170 is implanted into semiconductor substrate 110 to form fourth implant areas 172 and 174. If an NMOS transistor is to be formed, arsenic is preferably used as the implant. If a PMOS transistor is to be formed, boron is preferably used. Fourth dopant concentration is relatively high. In addition, high implant energies are used for the first implant so as to implant the dopants deep into semiconductor substrate 110. Dopants 170 are implanted into semiconductor substrate 110 a spaced distance d 1 from sidewall surfaces 116 and 120 due to masking incurred by nitride spacers 160 and 162. The interior edges of source/drain regions 172 and 174 are horizontally aligned with exterior sidewall surfaces of nitride spacers 160 and 162. Thermal anneal 175 is then performed to activate the fourth concentration of dopants and diffuse them into position. In a preferred embodiment, thermal anneal 175 is performed in RTA chamber. In an alternative embodiment, thermal anneal 175 may be performed in a conventional furnace. Thermal anneal 175 is performed at a relatively high temperature T 1 due to the depth of the implants and their high concentrations. High temperatures are especially required for an NMOS device where the preferred implant is arsenic which has low diffusivity. More energy is needed to activate arsenic and diffuse it into position.
FIG. 14 indicates removal of layers 160 and 162, which are preferably nitride. Nitride layers 160 and 162 are removed preferably using a wet etch. An etchant such as phosphoric acid is used which etches through the nitride but not through the underlying oxide. As a result only one pair of spacers, in this case the exterior nitride spacers, are removed while the other sets of spacers remain in place. A third concentration of dopants 176 of the same species of the previously placed dopants 170 is implanted into semiconductor substrate 110 to form third implant areas 178 and 180. Third dopant concentration is lower than fourth dopant concentration and requires less activation energy. Dopants 176 are implanted into semiconductor substrate 110 a spaced horizontal distance d 2 from sidewall surfaces 116 and 120 due to masking incurred by oxide spacers 148 and 150. Distance d 2 is less than distance d 1 . The interior edges of third implant areas 178 and 180 are horizontally aligned with exterior sidewall surfaces of oxide spacers 148 and 150. An optional thermal anneal 181 may be performed to activate the second dopant concentration and diffuse them into position. Thermal anneal 181 may be performed at a temperature T 2 which is less than temperature T 1 .
FIG. 15 illustrates removal of oxide layers 146, 148, and 150. Oxide layers 146, 148, and 150 are preferably deposited oxides removed using a wet etch. An etchant such as hydrofluoric acid is used which etches through the oxide but not through the underlying nitride spacers. Underlying thermally grown oxide 128 is harder to etch than CVD oxide 146, 148, and 150 and thus is less susceptible to the etchant. As a result, only one pair of spacers, in this case the CVD oxide spacers, are removed while the other sets of spacers remain in place. A second concentration of dopants 182 is implanted into semiconductor substrate 110 to form second implant areas 184 and 186. If an NMOS transistor is to be formed, arsenic or phosphorus are preferably used as the implant. If a PMOS transistor is to be formed, boron is preferably used. Second dopant concentration is lower than third dopant concentration and requires less activation energy. Distance d 3 is less than distance d 2 . The interior edges of source/drain regions 184 and 186 are horizontally aligned with exterior sidewall surfaces of nitride spacers 136 and 138. An optional thermal anneal 187 may be performed to activate the second dopant concentration and diffuse them into position. Thermal anneal 187 may be performed at a temperature T 3 which is less than temperature T 2 .
FIG. 16 illustrates removal of nitride spacers 136 and 138. Nitride spacers 136 and 138 are removed by preferably using a wet etch comprising phosphoric acid. The nitride spacers are removed while the underlying oxide remains in place. A first concentration of dopants 188 is implanted into semiconductor substrate 110 to form first implant area (LDD area) 190 and 192. First dopant concentration is less than the second dopant concentration. In addition, lower implant energies are used for the first implant compared to the implant energies used for the second implant. Dopants 188 are implanted into semiconductor substrate 110 a spaced horizontal distance d 4 from sidewall surfaces 116 and 120 due to masking incurred by oxide layer 128. Distance d 4 is less than distance d 3 . The interior edges of source/drain regions 190 and 192 are horizontally aligned with exterior sidewall surfaces of oxide layer 128. Thermal anneal 193 is then performed to activate the fourth concentration of dopants and diffuse them into position. If optional anneals 181 and 187 have not been performed, thermal anneal I 3 is also performed to activate the dopants of the second and third dopant concentration. Thermal anneal 175 is performed in RTA chamber at relatively low temperature T 4 due to the shallow placement of the implants and their low concentrations. Temperature T 4 is lower than temperature T 3 . Low temperatures are required since the fourth implant defines the length of the channel for the device. The first dopant concentration comprises phosphorus or boron, depending on whether the transistor is NMOS or PMCOS, which have relatively high diffusivities. Boron has an especially high diffusivity. Any excessive heating will cause lateral migration of the dopants and shorten the channel. Shortening the channel can cause harmful short-channel effects.
In the case where different materials may be used to form the spacers, the appropriate selective etchants need to be used for the removal of the spacers. If the spacers comprise silicon dioxide, hydrofluoric acid is preferably used; if the spacers comprise polysilicon, a combination of nitric acid and hydrofluoric acid is preferably used; and, if the spacers comprise nitride, phosphoric acid is preferably used. Alternatively, a plasma (dry) etch may be used to remove spacers. Different combinations of these materials may be used to form sequential spacers on the sidewall surfaces of gate conductor 114. However, any two adjacent spacers must have dissimilar etch characteristics to enable their sequential removal.
As shown in FIG. 17, oxide layer 128 may be etched away, and dielectric sidewall spacers 196 may be formed upon sidewall surfaces 116 and 120 of gate conductor 114. The exterior sidewall surfaces of sidewall spacers 196 are aligned with the exterior edges of third implant areas 178 and 180. Silicide layers 200, 202, and 198 are formed upon respective forth implant areas 172 and 174 and gate conductor 114.
The second embodiment benefits from all the advantages of a graded junction just as the first embodiment does. Using a reverse process for the formation of the LDD junction offers additional advantages, however. Each implant is usually followed by a thermal anneal in order to activate and diffuse the dopants into position. For higher dopant concentrations and for dopants with lower diffusivities, higher temperatures are required for the thermal anneal. Therefore, the first source/drain implant is the one requiring the highest temperature. The LDD implant requires the lowest thermal anneal since it typically comprises low concentrations of higher diffusivity ions. Furthermore, it is important not to provide excessive heat to the LDD implant. Any additional migration of the implant in the horizontal direction will reduce the length of the channel. Reducing the length of the channel will give rise to several harmful short-channel effects. Therefore, it is preferable to perform high temperature thermal anneals early in the process cycle. Performing the high temperature thermal anneals late in the process cycle will provide excessive heat to the dopants requiring low temperature thermal anneals.
It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to be capable of forming a graded source/drain junction, which produces an ultra-smooth doping profile, by forming a sequence of spacers with dissimilar etch characteristics on the sidewall surfaces of the gate conductor. Furthermore, it is also to be understood that the form of the invention shown and described is to be taken as exemplary, presently preferred embodiments. Various modifications and changes may be made without departing from the spirit and scope of the invention as set forth in the claims. It is intended that the following claims be interpreted to embrace all such modifications and changes.
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A transistor is provided with a graded source/drain junction. At least two dielectric spacers are formed in sequence upon the gate conductor. Adjacent dielectric spacers have dissimilar etch characteristics. An ion implant follows the formation of at least two of the dielectric spacers to introduce dopants into the source/drain region of the transistor. The ion implants are placed in different positions a spaced distance from the gate conductor according to a thickness of the dielectric spacers. As the implants are introduced further from the channel, the implant dosage and energy is increased. In a second embodiment, the ion implants are performed in reverse order. The dielectric spacers pre-exist on the sidewall surfaces of the gate conductor. The spacers are sequentially removed followed by an ion implant. An etchant is used which attacks the spacer to be removed but not the spacer beneath to the one being removed. Each time, the implants are performed with a lower energy and with a lower dosage so as to grade the junction with lighter concentrations and energies as the implant areas approach the channel. Reversing the implantation process enables high-temperature thermal anneals required for high-concentration low-diffusivity dopants to be performed first. The LDD implant comprises dopants of lower concentration and higher diffusivity requiring lower temperature anneals. Performing lower temperature anneals later in the sequence affords a lessened opportunity for undesirable short-channel effects.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. Ser. No. 12/177,927, filed 2008-07-23, which is a continuation of U.S. Ser. No. 11/464,835, filed 2006-08-16, which is a continuation of U.S. Ser. No. 10/209,399, filed 2002-07-29, which claims the benefit of U.S. Provisional Application No. 60/329,997, filed 2001-10-18, all of which are hereby incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The invention relates to communication device and more particularly to the communication device which has a capability to communicate with another communication device in a wireless fashion.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 6,363,320 introduces a system for tracking objects which includes a database for storing reference data as line segments corresponding to coordinate locations along environmental reference features; mobile units for connection to the objects for receiving coordinate object target point locations, and having means for receiving signals from an external location system and for generating the object data, and a wireless object data transmitter; and a computer having access to the database and to the object data, and generating an interpreted location of each of the objects in terms relative to automatically selected ones of the reference features. Also disclosed is a method for tracking the objects. Further disclosed is a computer program embodied on a computer-readable medium and having code segments for tracking objects according to the method. In this prior art, FIG. 2 illustrates the theory and/or the concept of producing and displaying a plurality of two-dimensional images on a display of a wireless communication devise, however, does not disclose the wireless communication device and the method thereof which implements the 1st function and the 2nd function; when the 1st function is implemented, the video image generator processes a plurality of two-dimensional images and the plurality of two-dimensional images are displayed on the display, and when the 2nd function is implemented, the video image generator processes a plurality of two-dimensional images and a plurality of three-dimensional images, both of which are displayed on the display.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system and method to facilitate the user of the communication device to enjoy both two-dimensional images and three-dimensional images displayed thereon.
Still another object is to overcome the aforementioned shortcomings associated with the prior art.
Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description which follows, when considered with the attached figures.
The present invention introduces the wireless communication device and the method thereof which implements the 1st function and the 2nd function; when the 1st function is implemented, the video image generator processes a plurality of two-dimensional images and the plurality of two-dimensional images are displayed on the display, and when the 2nd function is implemented, the video image generator processes a plurality of two-dimensional images and a plurality of three-dimensional images, both of which are displayed on the display.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other aspects, features, and advantages of the invention will be better understood by reading the following more particular description of the invention, presented in conjunction with the following drawings, wherein:
FIG. 1 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 2 a is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 2 b is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 2 c is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 3 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 4 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 5 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 6 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 6 b is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 7 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 8 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 9 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 10 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 11 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 12 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 13 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 14 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 14 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 15 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 16 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 17 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 17 b is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 18 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 19 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 20 a is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 20 b is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 21 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 22 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 23 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 24 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 25 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 26 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 27 a is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 27 b is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 28 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 29 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 30 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 31 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 32 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 32 a is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 32 b is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 32 c is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 32 d is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 32 e is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 32 f is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 32 g is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 33 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 34 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 35 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 35 b is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 36 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 37 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 38 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 39 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 40 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 41 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 42 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 43 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 44 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 44 b is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 44 c is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 44 d is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 44 e is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 45 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 46 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 47 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 48 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 49 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 50 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 51 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 52 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 53 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 53 b is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 54 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 55 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 56 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 57 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 58 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 59 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 60 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 61 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 61 b is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 62 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 63 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 64 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 65 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 66 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 67 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 68 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 69 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 70 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 71 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 72 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 73 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 74 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 74 a is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 75 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 76 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 77 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 78 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 79 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 80 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 81 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 82 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 83 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 84 is a flowchart illustrating an exemplary embodiment of the present invention.
FIG. 85 is a block diagram illustrating an exemplary embodiment of the present invention.
FIG. 86 is a simplified illustration illustrating an exemplary embodiment of the present invention.
FIG. 87 is a flowchart illustrating an exemplary embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description is of the best presently contemplated mode of carrying out the present invention. This description is not to be taken in a limiting sense but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined by referencing the appended claims.
FIG. 1 is a simplified block diagram of the communication device 200 utilized in the present invention. In FIG. 1 communication device 200 includes CPU 211 which controls and administers the overall function and operation of communication device 200 . CPU 211 uses RAM 206 to temporarily store data and/or to perform calculation to perform its function. Video processor 202 generates analog and/or digital video signals which are displayed on LCD 201 . ROM 207 stores data and programs which are essential to operate communication device 200 . Wireless signals are received by antenna 218 and processed by signal processor 208 . Input signals are input by input device 210 , such as dial pad, and the signal is transferred via input interface 209 and data bus 203 to CPU 211 . Indicator 212 is an LED lamp which is designed to output different colors (e.g., red, blue, green, etc). Analog audio data is input to microphone 215 . A/D 213 converts the analog audio data into a digital format. Speaker 216 outputs analog audio data which is converted into an analog format by D/A 204 . Sound processor 205 produces digital audio signals that are transferred to D/A 204 and also processes the digital audio signals transferred from A/D 213 . CCD unit 214 captures video image which is stored in RAM 206 in a digital format. Vibrator 217 vibrates the entire device by the command from CPU 211 .
FIG. 2 a illustrates one of the preferred methods of the communication between two communication devices. In FIG. 2 a both device A and device B represents communication device 200 in FIG. 1 . Device A transfers wireless data to transmitter 301 which relays the data to host 303 via cable 302 . The data is transferred to transmitter 308 (e.g., a satellite dish) via cable 320 and then to artificial satellite 304 . Artificial satellite 304 transfers the data to transmitter 309 which transfers the data to host 305 via cable 321 . The data is then transferred to transmitter 307 via cable 306 and to device B in a wireless format.
FIG. 2 b illustrates another preferred method of the communication between two communication devices. In this example device A directly transfers the wireless data to host 310 , an artificial satellite, which transfers the data directly to device B.
FIG. 2 c illustrates another preferred method of the communication between two communication devices. In this example device A transfers wireless data to transmitter 312 , an artificial satellite, which relays the data to host 313 , which is also an artificial satellite, in a wireless format. The data is transferred to transmitter 314 , an artificial satellite, which relays the data to device B in a wireless format.
Voice Recognition
Communication device 200 has a function to operate the device by the user's voice or convert the user's voice into a text format (i.e., voice recognition). Such function can be enabled by the technologies primarily introduced in the following inventions: U.S. Pat. No. 6,282,268; U.S. Pat. No. 6,278,772; U.S. Pat. No. 6,269,335; U.S. Pat. No. 6,269,334; U.S. Pat. No. 6,260,015; U.S. Pat. No. 6,260,014; U.S. Pat. No. 6,253,177; U.S. Pat. No. 6,253,175; U.S. Pat. No. 6,249,763; U.S. Pat. No. 6,246,990; U.S. Pat. No. 6,233,560; U.S. Pat. No. 6,219,640; U.S. Pat. No. 6,219,407; U.S. Pat. No. 6,199,043; U.S. Pat. No. 6,199,041; U.S. Pat. No. 6,195,641; U.S. Pat. No. 6,192,343; U.S. Pat. No. 6,192,337; U.S. Pat. No. 6,188,976; U.S. Pat. No. 6,185,530; U.S. Pat. No. 6,185,529; U.S. Pat. No. 6,185,527; U.S. Pat. No. 6,182,037; U.S. Pat. No. 6,178,401; U.S. Pat. No. 6,175,820; U.S. Pat. No. 6,163,767; U.S. Pat. No. 6,157,910; U.S. Pat. No. 6,119,086; U.S. Pat. No. 6,119,085; U.S. Pat. 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No. 3,770,892. The voice recognition function can be performed in terms of software by using area 261 , the voice recognition working area, of RAM 206 ( FIG. 1 ) which is specifically allocated to perform such function as described in FIG. 3 , or can also be performed in terms of hardware circuit where such space is specifically allocated in area 282 of sound processor 205 ( FIG. 1 ) for the voice recognition system as described in FIG. 4 .
FIG. 5 illustrates how the voice recognition function is activated. CPU 211 ( FIG. 1 ) periodically checks the input status of input device 210 ( FIG. 1 ) (S 1 ). If the CPU 211 detects a specific signal input from input device 210 (S 2 ) the voice recognition system which is described in FIG. 2 and/or FIG. 3 is activated.
Voice RecognitionโDialing/Auto-Off During Call
FIG. 6 a and FIG. 6 b illustrate the operation of the voice recognition in the present invention. Once the voice recognition system is activated (S 1 ) the analog audio data is input from microphone 215 ( FIG. 1 ) (S 2 ). The analog audio data is converted into digital data by A/D 213 ( FIG. 1 ) (S 3 ). The digital audio data is processed by sound processor 205 ( FIG. 1 ) to retrieve the text and numeric information therefrom (S 4 ). Then the numeric information is retrieved (S 5 ) and displayed on LCD 201 ( FIG. 1 ) (S 6 ). If the retrieved numeric information is not correct (S 7 ) the user can input the correct numeric information manually by using input device 210 ( FIG. 1 ) (S 8 ). Once the sequence of inputting the numeric information is completed the entire numeric information is displayed on LCD 201 and the sound is output from speaker 216 under control of CPU 211 (S 10 ). If the numeric information is correct (S 11 ) communication device 200 ( FIG. 1 ) initiates the dialing process by using the numeric information (S 12 ). The dialing process continues until communication device 200 is connected to another device (S 13 ). Once CPU 211 detects that the line is connected it automatically deactivates the voice recognition system (S 14 ). CPU 211 checks the status communication device 200 periodically (S 1 ) as described in FIG. 7 and remains the voice recognition system offline during call (S 2 ). If the connection is severed, i.e., user hangs up, then CPU 211 reactivates the voice recognition system (S 3 ).
Voice RecognitionโTag
FIG. 8 through FIG. 12 describes the method of inputting the numeric information in a convenient manner. RAM 206 includes Table # 1 ( FIG. 8 ) and Table # 2 ( FIG. 9 ). In FIG. 8 audio information # 1 corresponds to tag โScott.โ Namely audio information, such as wave data, which represents the sound of โScottโ (sounds like โS-ko-tโ) is registered in Table # 1 , which corresponds to tag โScottโ. In the same manner audio information # 2 corresponds to a tag โCarolโ; audio information # 3 corresponds to a tag โPeterโ; audio information # 4 corresponds to a tag โAmyโ; and audio information # 5 corresponds to a tag โBrian.โ In FIG. 9 tag โScottโ corresponds to numeric information โ(916) 411-2526โ; tag โCarolโ corresponds to numeric information โ(418) 675-6566โ; tag โPeterโ corresponds to numeric information โ(220) 890-1527โ; tag โAmyโ corresponds to numeric information โ(615) 125-3411โ; and tag โBrianโ corresponds to numeric information โ(042) 643-2097.โ FIG. 11 illustrates how CPU 211 ( FIG. 1 ) operates by utilizing both Table # 1 and Table # 2 . Once the audio data is processed as described in S 4 of FIG. 6 CPU 211 scans Table # 1 (S 1 ). If the retrieved audio data matches with one of the audio information registered in Table # 1 (S 2 ) it scans Table # 2 (S 3 ) and retrieves the corresponding numeric information from Table # 2 (S 4 ). FIG. 10 illustrates another embodiment of the present invention. Here, RAM 206 includes Table #A instead of Table # 1 and Table # 2 described above. In this embodiment audio info # 1 (i.e., wave data which represents the sound of โScotโ) directly corresponds to numeric information โ(916) 411-2526.โ In the same manner audio info # 2 corresponds to numeric information โ(410) 675-6566โ; audio info # 3 corresponds to numeric information โ(220) 890-1567โ; audio info # 4 corresponds to numeric information โ(615) 125-3411โ; and audio info # 5 corresponds to numeric information โ(042)645-2097.โ FIG. 12 illustrates how CPU 211 ( FIG. 1 ) operates by utilizing Table #A. Once the audio data is processed as described in S 4 of FIG. 6 CPU 211 scans Table #A (S 1 ). If the retrieved audio data matches with one of the audio information registered in Table #A (S 2 ) it retrieves the corresponding numeric information therefrom (S 3 ). As another embodiment RAM 206 may contain only Table # 2 and tag can be retrieved from the voice recognition system explained in FIG. 3 through FIG. 7 . Namely once the audio data is processed by CPU 211 as described in S 4 of FIG. 6 and retrieves the text data therefrom and detects one of the tags registered in Table # 2 (e.g., โScotโ) it retrieves the corresponding numeric information (e.g., โ(916) 411-2526โ) from the same table.
Voice RecognitionโBackground Noise Filter
FIG. 13 through FIG. 15 describes the method of minimizing the undesired effect of the background noise. ROM 207 includes area 255 and area 256 . Sound audio data which represents background noise is stored in area 255 , and sound audio data which represents the beep, ringing sound and other sounds which are emitted from the communication device 200 are stored in area 256 . FIG. 14 describes how these data are utilized. When the voice recognition system is activated as described in FIG. 5 the analog audio data is input from microphone 215 ( FIG. 1 ) (S 1 ). The analog audio data is converted into digital data by A/D 213 ( FIG. 1 ) (S 2 ). The digital audio data is processed by sound processor 205 ( FIG. 1 ) (S 3 ) and compared to the data stored in area 255 and area 256 (S 4 ). Such comparison can be done by either sound processor 205 or CPU 211 . If the digital audio data matches to the data stored in area 255 and/or area 256 the filtering process is initiated and deleted as background noise. Such sequence of process is done before retrieving text and numeric information from the digital audio data. FIG. 14 a describes the method of updating area 255 . When the voice recognition system is activated as described in FIG. 5 the analog audio data is input from microphone 215 ( FIG. 1 ) (S 1 ). The analog audio data is converted into digital data by A/D 213 ( FIG. 1 ) (S 2 ). The digital audio data is processed by sound processor 205 ( FIG. 1 ) (S 3 ) and the background noise is captured (S 4 ). CPU 211 ( FIG. 1 ) scans area 255 and if the captured background noise is not registered in area 255 it updates the sound audio data stored therein. FIG. 15 describes another embodiment of the present invention. CPU 211 ( FIG. 1 ) routinely checks whether the voice recognition system is activated (S 1 ). If the system is activated (S 2 ) the beep, ringing sound and other sounds which are emitted from the communication device 200 are automatically turned off (S 3 ).
Voice RecognitionโAutomatic Turn-Off The voice recognition system can automatically be turned off to avoid glitch as described in FIG. 16 . When the voice recognition system is activated (S 1 ) CPU 211 ( FIG. 1 ) automatically sets a timer (S 2 ). The value of timer (i.e., the length of time until the system is deactivated) can be set manually by the user. The timer is incremented periodically (S 3 ) and if the incremented time equals to the predetermined value of time as set in S 2 (S 4 ) the voice recognition system is automatically deactivated (S 5 ).
Voice RecognitionโE-Mail
FIG. 17 a and FIG. 17 b illustrate the method of typing and sending e-mails by utilizing the voice recognition system. Once the voice recognition system is activated (S 1 ) the analog audio data is input from microphone 215 ( FIG. 1 ) (S 2 ). The analog audio data is converted into digital data by A/D 213 ( FIG. 1 ) (S 3 ). The digital audio data is processed by sound processor 205 ( FIG. 1 ) to retrieve the text and numeric information therefrom (S 4 ). Then the text and numeric information are retrieved (S 5 ) and displayed on LCD 201 ( FIG. 1 ) (S 6 ). If the retrieved information is not correct (S 7 ) the user can input the correct text and/or numeric information manually by using the input device 210 ( FIG. 1 ) (S 8 ). If inputting the text and numeric information is completed (S 9 ) and CPU 211 detects input signal from input device 210 to send the e-mail (S 10 ) the dialing process is initiated (S 11 ). The dialing process is repeated until communication device 200 is connected to its host (S 12 ) and the e-mail is sent to the designated address (S 13 ).
Voice RecognitionโSpeech-To-Text
FIG. 18 illustrates the speech-to-text function of communication device 200 . Once communication device 200 receives a transmitted data from another device via antenna 218 (FIG. 1 ) (S 1 ) signal processor 208 ( FIG. 1 ) processes the data (e.g., such as decompression) (S 2 ) and the transmitted data is converted into audio data (S 3 ). Such conversion can be done by either CPU 211 ( FIG. 1 ) or signal processor 208 . The audio data is transferred to sound processor 205 ( FIG. 1 ) via data bus 203 and text and numeric information are retrieved therefrom (S 4 ). CPU 211 designates the predetermined font and color to the text and numeric information (S 5 ) and also designates a tag to such information (S 6 ). After these tasks are completed the tag and the text and numeric information are stored in RAM 206 and displayed on LCD 201 (S 7 ). FIG. 19 illustrates how the text and numeric information as well as the tag are displayed. On LCD 201 the text and numeric information 702 (โXXXXXXXXXโ) are displayed with the predetermined font and color as well as with the tag 701 (โJohnโ).
Positioning System
FIG. 20 a illustrates the simplified block diagram to detect the position of communication device 200 . In FIG. 20 a relay R 1 is connected to cable C 1 , relay R 2 is connected to cable C 2 , relay R 3 is connected to cable C 3 , and relay R 4 is connected to cable C 4 . Cables C 1 , C 2 , C 3 , and C 4 are connected to transmitter T, which is connected to host H by cable C 5 . The relays (R 1 . . . R 20 ) are located throughout the predetermined area in the pattern illustrated in FIG. 20 b . The system illustrated in FIG. 20 a and FIG. 20 b is designed to pin-point the position of communication device 200 by using the method so-called โglobal positioning systemโ or โGPS.โ
FIG. 21 through FIG. 26 illustrate how the positioning is performed. Assuming that device A, communication device 200 , seeks to detect the position of device B, another communication device 200 , which is located somewhere in the matrix of relays illustrated in FIG. 20 b . First of all the device ID of device B is entered by using input device 210 ( FIG. 1 ) of device A (S 1 ). The device ID may be its corresponding phone number. A request data including the device ID is sent to host H from device A (S 2 ).
As illustrated in FIG. 22 host H periodically receives data from Device A (S 1 ). If the received data is the request data (S 2 ) host H first of all searches its communication log which records the location of device B which it last communicated with host H (S 3 ). Then host H sends search signal from relays described in FIG. 20 b which are located within 100 meter radius from the location registered in the communication log. If there is no response from Device B (S 5 ) host H sends search signal from all relays (from R 1 to R 20 in FIG. 20 b ) (S 6 ).
As illustrated in FIG. 23 device B periodically receives data from host H (S 1 ). If the data received is the search signal (S 2 ) device B sends response signal to host H (S 3 ).
As illustrated in FIG. 24 host H periodically receives data from device B (S 1 ). If the data received is the response signal (S 2 ) host H locates the position of device B by using the method described in FIG. 20 a and FIG. 20 b (S 3 ), and sends the location data and the relevant map data of the area where device B is located to device A (S 4 ).
As illustrated in FIG. 25 device A periodically receives data from host H (S 1 ). If the data received is the location data and the relevant map data mentioned above device A displays the map based on the relevant map data and indicates the location thereon based on the location data (S 3 ).
Device A can continuously track down the location of device B as illustrated in FIG. 26 . First, device A sends a request data to host H (S 1 ). As soon as host H receives the request data (S 2 ) it sends a search signal in the manner illustrated in FIG. 22 (S 3 ). As soon as device B receives the search signal (S 4 ) it sends a response signal to host H (S 5 ). Based on the response signal host H locates device B with the method described in FIG. 20 a and FIG. 20 b (S 6 ). Then host H sends to device A a renewed location data and a relevant map data of the area where device B is located (S 7 ). As soon as these data are received (S 8 ) device A displays the map based on the relevant map data and indicates the updated location based on the renewed location data (S 9 ). If device B is still within the specified area device A may use the original relevant map data. As another embodiment of the present invention S 1 through S 4 may be omitted and make device B send a response signal continuously to host H until host H sends a command signal to device B to cease sending the response signal.
Positioning SystemโAutomatic Silent Mode
FIG. 27 a through FIG. 32 g illustrate the automatic silent mode of communication device 200 .
In FIG. 27 a relay R 1 is connected to cable C 1 , relay R 2 is connected to cable C 2 , relay R 3 is connected to cable C 3 , and relay R 4 is connected to cable C 4 . Cables C 1 , C 2 , C 3 , and C 4 are connected to transmitter T, which is connected to host H by cable C 5 . The relays (R 1 . . . R 20 ) are located throughout the predetermined area in the pattern illustrated in FIG. 27 b . The system illustrated in FIG. 27 a and FIG. 27 b is designed to pin-point the position of communication device 200 by using the method so-called โglobal positioning systemโ or โGPS.โ
As illustrated in FIG. 28 the user of communication device 200 may set the silent mode by input device 210 ( FIG. 1 ). When communication device 200 is in the silent mode (a) the ringing sound is turned off, (b) vibrator 217 ( FIG. 1 ) activates when communication device 200 receives call, and/or (c) communication device 200 sends a automatic response to the caller device when a call is received. The user may, with his discretion, select any of these predetermined function of the automatic silent mode.
FIG. 29 illustrates how the automatic silent mode is activated. Communication device 200 checks its present location with the method so-called โglobal positioning systemโ or โGPSโ by using the system illustrated in FIG. 27 a and FIG. 27 b (S 1 ). Communication device 200 then compares the present location and the previous location (S 2 ). If the difference of the two values is more than the specified amount X, i.e., when the moving velocity of communication device 200 exceeds the predetermined value (S 3 ) the silent mode is activated and (a) the ringing sound is automatically turned off, (b) vibrator 217 ( FIG. 1 ) activates, and/or (c) communication device 200 sends an automatic response to the caller device according to the user's setting. Here, the silent mode is automatically activated because the user of communication device 200 is presumed to be on an automobile and is not in a situation to freely answer the phone, or the user is presumed to be riding a train and does not want to disturb other passengers.
As another embodiment of the present invention the automatic silent mode may be administered by host H ( FIG. 27 a ). As illustrated in FIG. 30 the silent mode is set in the manner described in FIG. 28 (S 1 ) and communication device 200 sends to host H a request signal. When host H detects a call to communication device 200 after receiving the request signal it checks the current location of communication device 200 (S 1 ) and compares it with the previous location (S 2 ). If the difference of the two values is more than the specified amount X, i.e., when the moving velocity of communication device 200 exceeds the predetermined value (S 3 ) host H sends a notice signal to communication device 200 (S 4 ). As illustrated in FIG. 32 communication device 200 receives data periodically from host H (S 1 ). If the received data is a notice signal (S 2 ) communication device 200 activates the silent mode (S 3 ) and (a) the ringing sound is automatically turned off, (b) vibrator 217 ( FIG. 1 ) activates, and/or (c) communication device 200 sends an automatic response to the caller device according to the user's setting. The automatic response may be sent from host H instead.
As another embodiment of the present invention a train route data may be used. As illustrated in FIG. 32 a the train route data is stored in area 263 of RAM 206 . The train route data contains three-dimensional train route map including the location data of the route. FIG. 32 b illustrates how the train route data is utilized. CPU 211 ( FIG. 1 ) checks the present location of communication device 200 by the method described in FIG. 27 a and FIG. 27 b (S 1 ). Then CPU 211 compares with the train route data stored in area 263 of RAM 206 (S 2 ). If the present location of communication 200 matches the train route data (i.e., if communication device is located on the train route) (S 3 ) the silent mode is activated in the manner described above. The silent mode is activated because the user of communication device 200 is presumed to be currently on the train and may not want to disturb the other passengers on the same train. As another embodiment of the present invention such function can be delegated to host H ( FIG. 27 a ) as described in FIG. 32 c . Namely, host H checks the present location of communication device 200 by the method described in FIG. 27 a and FIG. 27 b (S 1 ). Then host H compares the present location with the train route data stored in its own storage (not shown) (S 2 ). If the present location of communication 200 matches the train route data (i.e., if communication device is located on the train route) (S 3 ) host H sends a notice signal to communication device 200 thereby activating the silent mode in the manner described above.
Another embodiment is illustrated in FIG. 32 f and FIG. 32 g . As illustrated in FIG. 32 f relays R 101 , R 102 , R 103 , R 104 , R 105 , R 106 , which perform the same function to the relays described in FIG. 27 a and FIG. 27 b , are installed in train Tr. The signals from these relays are sent to host H illustrated in FIG. 27 a . Relays R 101 through R 106 emit inside-the-train signals which are emitted only inside train Tr. FIG. 32 g illustrates how communication device 200 operates inside train Tr. Communication device 200 checks the signal received in train Tr (S 1 ). If communication device 200 determines that the signal received is an inside-the-train signal (S 2 ) it activates the silent mode in the manner described above.
Positioning SystemโAuto Response
FIG. 32 d and FIG. 32 e illustrates the method to send an automatic response to a caller device when the silent mode is activated. Assume that the caller device, a communication device 200 , intends to call a callee device, another communication device 200 via host H. As illustrated in FIG. 32 d the caller device dials the callee device and the dialing signal is sent to host H (S 1 ). Host H checks whether the callee device is in the silent mode (S 2 ). If host H detects that the callee device is in the silent mode it sends a predetermined auto response which indicates that the callee is probably on a train and may currently not be available, which is received by the caller device (S 3 ). If the user of the caller device still desires to request for connection and certain code is input from input device 210 ( FIG. 1 ) (S 4 ) a request signal for connection is sent and received by host H (S 5 ), and the line is connected between the caller device and the callee device via host H (S 6 ). As another embodiment of the present invention the task of host H which is described in FIG. 32 d may be delegated to the callee device as illustrated in FIG. 32 e . The caller device dials the callee device and the dialing signal is sent to the callee device via host H (S 1 ). The callee device checks whether it is in the silent mode (S 2 ). If the callee device detects that it is in the silent mode it sends an predetermined auto response which indicates that the callee is probably on a train and may currently not be available, which is sent to the caller device via host H (S 3 ). If the user of the caller device still desires to request for connection and certain code is input from input device 210 ( FIG. 1 ) (S 4 ) a request signal for connection is sent to the callee device via host H (S 5 ), and the line is connected between the caller device and the callee device via host H (S 6 ).
Auto Backup
FIG. 32 through FIG. 37 illustrate the automatic backup system of communication device 200 . As illustrated in FIG. 32 RAM 206 ( FIG. 1 ) includes areas to store the data essential to the user of communication device 200 , such as area 278 for a phone list, area 279 for an address book, area 280 for email data, area 281 for software A, area 282 for software B, area 283 for software C, area 284 for data D, area 285 for data E. RAM 206 also includes area 264 , i.e., the selected data info storage area, which will be explained in details hereinafter.
As described in FIG. 34 the user selects data by using input device 210 ( FIG. 1 ) which he/she intends to be automatically backed up (S 1 ). The selected data are written in area 264 , the selected data info storage area (S 2 ).
The overall operation of this function is illustrated in FIG. 35 a and FIG. 35 b . First of all, a timer (not shown) is set by a specific input signal produced by input device 210 ( FIG. 1 ) (S 1 ). The timer is incremented periodically (S 2 ) and when the incremented value equals the predetermined value (S 3 ) communication device 200 initiates the dialing process (S 4 ). The dialing process continues until communication device 200 is connected to host 400 explained in FIG. 37 (S 5 ). Once the line is connected CPU 211 reads the information stored in area 264 (S 6 ) and based on such information it initiates to transfer the selected data from RAM 206 to host 400 (S 7 ). The transfer continues until all of the selected data are transferred to host 400 (S 8 ) and the line is disconnected thereafter (S 9 ). This backup sequence can be initiated automatically and periodically by using a timer or manually. As another embodiment of the present invention, instead of selecting the data that are to be backed up, all data in RAM 206 ( FIG. 1 ) can be transferred to host 400 .
FIG. 36 illustrates the basic structure of the data transferred to host 400 . Transferred data 601 includes header 602 , device ID 603 , selected data 604 and footer 605 . Device ID 603 is the identification number of communication device 200 preferably its phone number, and selected data 604 is the pack of data which are transferred from RAM 206 to host 400 based on information stored in area 264 .
FIG. 37 illustrates the basic structure of host 400 . Host 400 includes backup data storage area 401 which is used to backup all of the backup data transferred from all communication devices. Host 400 stores the transferred data 601 to the designated area based on the device ID included in transferred data 601 . For example, transferred data 601 transferred from device A is stored in area 412 as backup data A. In the same manner transferred data 601 transferred from device B is stored in area 413 as backup data B; transferred data 601 transferred from device C is stored in area 414 as backup data C; transferred data 601 transferred from device D is stored in area 415 as backup data D; transferred data 601 transferred from device E is stored in area 416 as backup data E; and transferred data 601 transferred from device F is stored in area 417 as backup data F.
Signal Amplifier
FIG. 38 illustrates a signal amplifier utilized for automobiles and other transportation carriers, such as trains, airplanes, space shuttles, and motor cycles. As described in FIG. 38 automobile 500 includes interface 503 , an interface detachably connectable to communication device 200 , which is connected to amplifier 502 via cable 505 : Amplifier 502 is connected to antenna 501 via cable 504 and connector 507 as described in this drawing. The signal produced by communication device 200 is transferred to interface 503 . Then the signal is transferred to amplifier via cable 505 where the signal is amplified. The amplified signal is transferred to antenna 501 via cable 504 and connector 507 , which transmits the amplified signal to host H (not shown). The receiving signal is received by antenna 501 and transferred to amplifier 502 via connector 507 and cable 504 , and then is transferred to interface 503 via cable 505 , which transfers the amplified signal to communication device 200 .
Audio/Video Data Capturing System
FIG. 39 through FIG. 44 illustrate the audio/video capturing system of communication device 200 . Assuming that device A, a communication device 200 , captures audio/video data and transfers such data to device B, another communication device 200 , via a host (not shown). Primarily video data is input from CCD unit 214 ( FIG. 1 ) and audio data is input from microphone 215 of ( FIG. 1 ) of device A. As illustrated in FIG. 39 RAM 206 includes area 267 which stores audio data, area 268 which stores video data, and area 265 which is a work area utilized for the process explained hereinafter.
As described in FIG. 40 the video data input from CCD unit 214 (S 1 a ) is converted from analog data to digital data (S 2 a ) and is processed by CCD unit 214 (S 3 a ). Area 265 is used as work area for such process. The processed video data is stored in area 267 of RAM 206 (S 4 a ) and displayed on LCD 201 ( FIG. 1 ). As described in the same drawing the audio data input from microphone 215 (S 1 b ) is converted from analog data to digital data by A/D 213 ( FIG. 1 ) (S 2 b ) and is processed by sound processor 205 ( FIG. 1 ) (S 3 b ). Area 265 is used as work area for such process. The processed audio data is stored in area 268 of RAM 206 (S 4 b ) and is transferred to sound processor 205 and is output from speaker 216 ( FIG. 1 ) via D/A 204 ( FIG. 1 ) (S 5 b ). The sequences of S 1 a through S 5 a and S 1 b through S 5 b are continued until a specific signal indicating to stop such sequence is input from input device 210 ( FIG. 1 ) (S 6 ).
As described in FIG. 41 CPU 211 ( FIG. 1 ) of device A initiates a dialing process (S 1 ) until the line is connected to a host (not shown) (S 2 ). As soon as the line is connected CPU 211 reads the audio/video data stored in area 267 and area 268 (S 3 ) and transfer them to signal processor 208 where the data are converted into a transferring data (S 4 ). The transferring data is transferred from antenna 218 in a wireless fashion (S 5 ). The sequence of S 1 through S 5 is continued until a specific signal indicating to stop such sequence is input from input device 210 ( FIG. 1 ) (S 6 ). The line is disconnected thereafter (S 7 ).
FIG. 42 illustrates the basic structure of the transferred data which is transferred from device A as described in S 4 and S 5 of FIG. 41 . Transferred data 610 is primarily composed of header 611 , video data 612 , audio data 613 , relevant data 614 , and footer 615 . Video data 612 corresponds to the video data stored in area 267 of RAM 206 , and audio data 613 corresponds to the audio data stored in area 268 of RAM 206 . Relevant data 614 includes various types of data, such as the identification number of device A (i.e., transferor device) and device B (transferee device), a location data which represents the location of device A, etc.
FIG. 43 illustrates the data contained in RAM 206 ( FIG. 1 ) of device B. As illustrated in FIG. 39 RAM 206 includes area 269 which stores audio data, area 270 which stores video data, and area 266 which is a work area utilized for the process explained hereinafter.
As described in FIG. 44 a and FIG. 44 b CPU 211 ( FIG. 1 ) of device B initiates a dialing process (S 1 ) until device B is connected to a host (not shown) (S 2 ). Transferred data 610 is received by antenna 218 ( FIG. 1 ) of device B (S 3 ) and is converted by signal processor 208 into a readable data which is readable by CPU 211 (S 4 ). Video data and audio data are retrieved from transferred data 610 and stored into area 269 and area 270 of RAM 206 respectively (S 5 ). The video data stored in area 269 is processed by video processor 202 ( FIG. 1 ) (S 6 a ). The processed video data is converted into an analog data (S 7 a ) and displayed on LCD 201 ( FIG. 1 ) (S 8 a ). S 7 a may not be necessary depending on the type of LCD 201 used. The audio data stored in area 270 is processed by sound processor 205 ( FIG. 1 ) (S 6 b ). The processed audio data is converted into analog data by D/A 204 ( FIG. 1 ) (S 7 b ) and output from speaker 216 ( FIG. 1 ) (S 8 b ). The sequences of S 6 a through S 8 a and S 6 b through S 8 b are continued until a specific signal indicating to stop such sequence is input from input device 210 ( FIG. 1 ) (S 9 ).
Digital Mirror
FIG. 44 c through FIG. 44 e illustrates the method of using communication device 200 as a mirror. In this embodiment communication device 200 includes rotator 291 as described in FIG. 44 c . Rotator 291 is fixed to the side of communication device 200 and rotates CCD unit 214 ( FIG. 1 ) and thereby CCD unit 214 is enabled to face multi-direction. CPU 211 ( FIG. 1 ) reads the video data stored in area 267 ( FIG. 39 ) from left to right as described in FIG. 44 d when CCD unit 214 is facing the opposite direction from LCD 201 . However, when CCD unit 214 is facing the same direction with LCD 201 , CPU 211 reads the video data stored in area 267 from right to left as described in FIG. 44 e thereby producing a โmirror imageโ on LCD 201 .
As another embodiment of the present invention more than one CCD units which face multi-direction may be utilized instead of enabling one CCD unit to rotate in the manner described above.
Caller ID
FIG. 45 through FIG. 47 illustrate the caller ID system of communication device 200 .
As illustrated in FIG. 45 RAM 206 includes Table C. As shown in the drawing each phone number corresponds to a specific color and sound. For example phone # 1 corresponds to color A and sound E; phone # 2 corresponds to color B and sound F; phone # 3 corresponds to color C and sound G; and phone # 4 corresponds to color D and sound H.
As illustrated in FIG. 46 the user of communication device 200 selects or inputs a phone number (S 1 ) and selects a specific color (S 2 ) and a specific sound (S 3 ) designated for that phone number. Such sequence can be repeated until there is a specific input from input device 210 ordering to do otherwise (S 4 ).
As illustrated in FIG. 47 CPU 211 ( FIG. 1 ) periodically checks whether it has received a call from other communication devices (S 1 ). If it receives a call (S 2 ) CPU 211 scans Table C ( FIG. 45 ) to see whether the phone number of the caller device is registered in the table (S 3 ). If there is a match (S 4 ) the designated color is output from indicator 212 ( FIG. 1 ) and the designated sound is output from speaker 216 ( FIG. 1 ) (S 5 ). For example if the incoming call is from phone # 1 color A is output from indicator 212 and sound E is output from speaker 216 .
Stock Purchase
FIG. 48 through FIG. 52 illustrate the method of purchasing stocks by utilizing communication device 200 .
FIG. 48 illustrates the data stored in ROM 207 ( FIG. 1 ) necessary to set the notice mode. Area 251 stores the program regarding the vibration mode; area 252 stores the program regarding sound which is emitted from speaker 216 ( FIG. 1 ) and several types of sound data, such as sound data I, sound data J, and sound data K; area 253 stores the program regarding the color emitted from indicator 212 ( FIG. 1 ) and several types of color data, such as color data L, color data, M, and color data N.
As illustrated in FIG. 49 the notice mode is activated in the manner in compliance with the settings stored in setting data area 271 of RAM 206 . In the example illustrated in FIG. 49 when the notice mode is activated vibrator 217 ( FIG. 1 ) is turned on in compliance with the data stored in area 251 a , speaker 216 ( FIG. 1 ) is turned on and sound data J is emitted therefrom in compliance with the data stored in area 252 a , and indicator 212 ( FIG. 1 ) is turned on and color M is emitted therefrom in compliance with the data stored in area 253 a . Area 292 stores the stock purchase data, i.e., the name of the brand, the amount of limited price, the name of the stock market (such as NASDAQ and/or NYSE) and other relevant information regarding the stock purchase.
As illustrated in FIG. 50 the user of communication device 200 inputs the stock purchase data from input device 210 ( FIG. 1 ), which is stored in area 292 of RAM 206 (S 1 ). By way of inputting specific data from input device 210 the property of notice mode (i.e., vibration ON/OFF, sound ON/OFF and the type of sound, indicator ON/OFF and the type of color) is set and the relevant data are stored in area 271 (i.e., areas 251 a , 252 a , 253 a ) of RAM 206 by the programs stored in areas 251 , 252 , 253 of ROM 207 (S 2 ). Communication device 200 initiates a dialing process (S 3 ) until it is connected to host H (described hereafter) (S 4 ) and sends the stock purchase data thereto.
FIG. 51 illustrates the operation of host H. As soon as host H receives the stock purchase data from communication device 200 (S 1 ) it initiates monitoring the stock markets which is specified in the stock purchase data (S 2 ). If host H detects that the price of the certain brand specified in the stock purchase data meets the limited price specified in the stock purchase data (S 3 ) it initiates a dialing process (S 4 ) until it is connected to communication device 200 (S 5 ) and sends a notice data thereto (S 6 ). As illustrated in FIG. 52 communication device 200 periodically monitors the data received from host H (S 1 ). If the data received is a notice data (S 2 ) the notice mode is activated in the manner in compliance with the settings stored in setting data area 271 of RAM 206 (S 3 ). In the example illustrated in FIG. 49 vibrator 217 ( FIG. 1 ) is turned on, sound data J is emitted from speaker 216 ( FIG. 1 ), and indicator 212 ( FIG. 1 ) emits color M.
Timer Email
FIG. 53 a and FIG. 53 b illustrate the method of sending emails from communication device 200 by utilizing a timer. Address data, i.e., email address is input by input device 210 or by voice recognition system explained in FIG. 3 , FIG. 4 , FIG. 5 , FIG. 13 , FIG. 14 , FIG. 14 a , FIG. 15 , FIG. 16 and/or FIG. 17 (S 1 ) and the text data, the text of the email message is input by the same manner (S 2 ). The address data and the text data are automatically saved in RAM 206 ( FIG. 1 ) (S 3 ). The sequence of S 1 through S 3 is repeated (i.e., writing more than one email) until a specified input signal is input from input device 210 or by utilizing the voice recognition system explained above ( FIG. 1 ). Once inputting both the address data and the text data (which also includes numeric data, images and programs) are completed a timer (not shown) is set by input device 210 or by utilizing the voice recognition system (S 5 ), and the timer is incremented periodically (S 6 ) until the timer value equals the predetermined value specified in S 5 (S 7 ). A dialing process is continued (S 8 ) until the line is connected (S 9 ) and the text data are sent thereafter to email addresses specified in S 1 (S 10 ). All of the emails are sent (S 11 ) and the line is disconnected thereafter (S 12 ).
As another embodiment of the present invention a specific time may be input by input device 210 and send the text data on the specific time (i.e., a broad meaning of โtimerโ).
Call Blocking
FIG. 54 through FIG. 56 illustrates the method of so-called โcall blocking.โ
As illustrated in FIG. 54 RAM 206 ( FIG. 1 ) includes area 273 and area 274 . Area 273 stores phone numbers that should be blocked. In the example illustrated in FIG. 54 phone # 1 , phone # 2 , and phone # 3 are blocked. Area 274 stores a message data stating that the phone can not be connected.
FIG. 55 illustrates the operation of communication device 200 . When communication device 200 receives a call (S 1 ), CPU 211 ( FIG. 1 ) scans area 273 of RAM 206 (S 2 ). If the phone number of the incoming call matches one of the phone numbers stored in area 273 of RAM 206 (S 3 ) CPU 211 sends the message data stored in area 274 of RAM 206 to the caller device (S 4 ) and disconnects the line (S 5 ).
FIG. 56 illustrates the method of updating area 273 of RAM 206 . Assuming that the phone number of the incoming call does not match any of the phone numbers stored in area 273 of RAM 206 (see S 3 of FIG. 55 ). In that case communication device 200 is connected to the caller device. However, the user of communication device 200 may decide to have such number โblockedโ after all. In that case the user dials โ999โ while the line is connected. Technically CPU 211 ( FIG. 1 ) periodically checks the signals input from input device 210 ( FIG. 1 ) (S 1 ). If the input signal represents โ9991โ from input device 210 (S 2 ) CPU 211 adds the phone number of the pending call to area 273 (S 3 ) and sends the message data stored in area 274 of RAM 206 to the caller device (S 4 ). The line is disconnected thereafter (S 5 ).
FIG. 57 through FIG. 59 illustrates another embodiment of the present invention.
As illustrated in FIG. 57 host 400 includes area 403 and area 404 . Area 403 stores phone numbers of communication device 200 that should be blocked. In the example illustrated in FIG. 57 phone # 1 , phone # 2 , and phone # 3 are blocked for device A; phone # 4 , phone # 5 , and phone # 6 are blocked for device B; and phone # 7 , phone # 8 , and phone # 9 are blocked for device C. Area 404 stores a message data stating that the phone can not be connected.
FIG. 58 illustrates the operation of host 400 . Assuming that the caller device is attempting to connect to device B illustrated in FIG. 57 . Host 400 periodically checks the signals from all communication device 200 (S 1 ). If host 400 detects a call for device B (S 2 ) it scans area 403 and checks whether the phone number of the incoming call matches one of the phone numbers stored therein (S 4 ). If the phone number of the incoming call does not match any of the phone numbers stored in area 403 the line is connected to device B (S 5 b ). On the other hand, if the phone number of the incoming call matches one of the phone numbers stored in area 403 the line is โblocked,โ i.e., not connected to device B (S 5 a ) and host 400 sends the massage data stored in area 404 to the caller device (S 6 ).
FIG. 59 illustrates the method of updating area 403 of host 400 . Assuming that the phone number of the incoming call does not match any of the phone numbers stored in area 403 (see S 4 of FIG. 58 ). In that case host 400 allows the connection between the caller device and communication device 200 . However, the user of communication device 200 may decide to have such number โblockedโ after all. In that case the user simply dials โ999โ while the line is connected. Technically host 400 ( FIG. 57 ) periodically checks the signals input from input device 210 ( FIG. 1 ) (S 1 ). If the input signal represents โ999โ from input device 210 ( FIG. 1 ) (S 2 ) host 400 adds the phone number of the pending call to area 403 (S 3 ) and sends the message data stored in area 404 to the caller device (S 4 ). The line is disconnected thereafter (S 5 ). As another embodiment of the method illustrated in FIG. 59 host 400 may delegate some of its tasks to communication device 200 (this embodiment is not shown in drawings). Namely communication device 200 periodically checks the signals input from input device 210 ( FIG. 1 ). If the input signal represents โ999โ from input device 210 communication device 200 sends to host a block request signal as well as with the phone number of the pending call. Host 400 , upon receiving the block request signal from communication device 200 , adds the phone number of the pending call to area 403 and sends the message data stored in area 404 to the caller device. The line is disconnected thereafter.
Online Payment
FIG. 60 through FIG. 64 illustrates the method of online payment by utilizing communication device 200 .
As illustrated in FIG. 60 host 400 includes account data storage area 405 . All of the account data of the users of communication device 200 who have signed up for the online payment service are stored in area 405 . In the example described in FIG. 60 account A stores the relevant account data of the user using device A; account B stores the relevant account data of the user using device B; account C stores the relevant account data of the user using device C; and account D stores the relevant account data of the user using device D. Here, device A, B, C, and D are communication device 200 .
FIG. 61 a and FIG. 61 b illustrate the operation of the payer device. Assuming that device A is the payer device and device B is the payee device. Account A explained in FIG. 60 stores the account data of the user of device A, and account B explained in the same drawing stores the account data of the user of device B. As illustrated in FIG. 61 a LCD 201 of device A displays the balance of account A by receiving the relevant data from host 400 ( FIG. 60 ) (S 1 ). From the signal input from input device 210 ( FIG. 1 ) the payer's account and the payee's account are selected (in the present example account A as the payer's account and account B as the payee's account), the amount of payment and the device ID (in the present example device A as the payer's device and device B as the payee's device) (S 2 ). If the data input from input device 210 is correct (S 3 ) CPU 211 ( FIG. 1 ) of device A prompts for other payments. If there are other payments to make the sequence of S 1 through S 3 is repeated until all of the payments are made (S 4 ). The dialing process is initiated and repeated thereafter (S 5 ) until the line is connected to host 400 (S 6 ). Once the line is connected device A sends the payment data to host 400 ( FIG. 60 ) (S 7 ). The line is disconnected when all of the payment data are sent to host 400 (S 8 and S 9 ).
FIG. 62 illustrates the payment data described in S 7 of FIG. 61 b . Payment data 620 is consisted of header 621 , payer's account information 622 , payee's account information 623 , amount data 624 , device ID data 625 , and footer 615 . Payer's account information 622 represents the information regarding the payer's account data stored in host 400 which is, in the present example, account A. Payee's account information 623 represents the information regarding the payee's account data stored in host 400 which is, in the present example, account B. Amount data 624 represents the amount of monetary value either in the U.S. dollars or in other currencies which is to be transferred from the payer's account to the payee's account. The device ID data represents the data of the payer's device and the payee's device, i.e., in the present example, device A and device B.
FIG. 63 illustrates the basic structure of the payment data described in S 7 of FIG. 61 b when multiple payments are made, i.e., when more than one payment is made in S 4 of FIG. 61 a . Assuming that three payments are made in S 4 of FIG. 61 a . In that case payment data 630 is consisted of header 631 , footer 635 , and three data sets, i.e., data set 632 , data set 633 , data set 634 . Each data set represents the data components described in FIG. 62 excluding header 621 and footer 615 .
FIG. 64 illustrates the operation of host 400 ( FIG. 60 ). After receiving payment data from device A described in FIG. 62 and FIG. 63 host 400 retrieves therefrom the payer's account information (in the present example account A), the payee's account information (in the present example account B), the amount data which represents the monetary value, the device IDs of both the payer's device and the payee's device (in the present example device A and device B) (S 1 ). Host 400 based on such data subtracts the monetary value represented by the amount data from the payer's account (in the present example account A) (S 2 ), and adds the same amount to the payee's account (in the present example account B) (S 3 ). If there are other payments to make, i.e., if host 400 received a payment data which has a structure of the one described in FIG. 63 the sequence of S 2 and S 3 is repeated as many times as the amount of the data sets are included in such payment data.
Navigation System
FIG. 65 through FIG. 74 illustrate the navigation system of communication device 200 .
As illustrated in FIG. 65 RAM 206 ( FIG. 1 ) includes area 275 , area 276 , area 277 , and area 295 . Area 275 stores a plurality of map data, two-dimensional (2D) image data, which are designed to be displayed on LCD 201 ( FIG. 1 ). Area 276 stores a plurality of object data, three-dimensional (3D) image data, which are also designed to be displayed on LCD 201 . The object data are primarily displayed by a method so-called โtexture mappingโ which is explained in details hereinafter. Here, the object data include the three-dimensional data of various types of objects that are displayed on LCD 201 , such as bridges, houses, hotels, motels, inns, gas stations, restaurants, streets, traffic lights, street signs, trees, etc. Area 277 stores a plurality of location data, i.e., data representing the locations of the objects stored in area 276 . Area 277 also stores a plurality of data representing the street address of each object stored in area 276 . In addition area 277 stores the current position data of communication device 200 and the destination data which are explained in details hereafter. The map data stored in area 275 and the location data stored in area 277 are linked each other. Area 295 stores a plurality of attribution data attributing to the map data stored in area 275 and location data stored in area 277 , such as road blocks, traffic accidents, and road constructions, and traffic jams. The attribution data stored in area 295 is updated periodically by receiving an updated data from a host (not shown).
As illustrated in FIG. 66 video processor 202 ( FIG. 1 ) includes texture mapping processor 290 . Texture mapping processor 290 produces polygons in a three-dimensional space and โpastesโ textures to each polygons. The concept of such method is described in the following patents: U.S. Pat. No. 5,870,101, U.S. Pat. No. 6,157,384, U.S. Pat. No. 5,774,125, U.S. Pat. No. 5,375,206, and/or U.S. Pat. No. 5,925,127.
As illustrated in FIG. 67 the voice recognition system is activated when the CPU 211 ( FIG. 1 ) detects a specific signal input from input device 210 ( FIG. 1 ) (S 1 ). After the voice recognition system is activated the input current position mode starts and the current position of communication device 200 is input by voice recognition system explained in FIG. 3 , FIG. 4 , FIG. 5 , FIG. 13 , FIG. 14 , FIG. 14 a , FIG. 15 , FIG. 16 and/or FIG. 17 (S 2 ). The current position can also be input from input device 210 . As another embodiment of the present invention the current position can automatically be detected by the method so-called โglobal positioning systemโ or โGPSโ as illustrated in FIG. 20 a through FIG. 26 and input the current data therefrom. After the process of inputting the current data is completed the input destination mode starts and the destination is input by the voice recognition system explained above or by the input device 210 (S 3 ), and the voice recognition system is deactivated after the process of inputting the destination data is completed by using such system (S 4 ).
FIG. 68 illustrates the sequence of the input current position mode described in S 2 of FIG. 67 . When analog audio data is input from microphone 215 ( FIG. 1 ) (S 1 ) such data is converted into digital audio data by A/D 213 ( FIG. 1 ) (S 2 ). The digital audio data is processed by sound processor 205 ( FIG. 1 ) to retrieve text and numeric data therefrom (S 3 ). The retrieved data is displayed on LCD 201 ( FIG. 1 ) (S 4 ). The data can be corrected by repeating the sequence of S 1 through S 4 until the correct data is displayed (S 5 ). If the correct data is displayed such data is registered as current position data (S 6 ). As stated above the current position data can input manually by input device 210 ( FIG. 1 ) and/or by automatically inputting such data by the method so-called โglobal positioning systemโ or โGPSโ as described above.
FIG. 69 illustrates the sequence of the input destination mode described in S 3 of FIG. 67 . When analog audio data is input from microphone 215 ( FIG. 1 ) (S 1 ) such data is converted into digital audio data by A/D 213 ( FIG. 1 ) (S 2 ). The digital audio data is processed by sound processor 205 ( FIG. 1 ) to retrieve text and numeric data therefrom (S 3 ). The retrieved data is displayed on LCD 201 ( FIG. 1 ) (S 4 ). The data can be corrected by repeating the sequence of S 1 through S 4 until the correct data is displayed (S 5 ). If the correct data is displayed such data is registered as destination data (S 6 ).
FIG. 70 illustrates the sequence of displaying the shortest route from the current position to the destination. CPU 211 ( FIG. 1 ) retrieves both the current position data and the destination data which are input by the method described in FIG. 67 through FIG. 69 from area 277 of RAM 206 ( FIG. 1 ). By utilizing the location data of streets, bridges, traffic lights and other relevant data CPU 211 calculates the shortest route to the destination (S 1 ). CPU 211 then retrieves the relevant two-dimensional map data which should be displayed on LCD 201 from area 275 of RAM 206 (S 2 ). As another embodiment of the present invention by way of utilizing the location data stored in area 277 CPU 211 may produce a three-dimensional map by composing the three dimensional objects (by method so-called โtexture mappingโ as described above) which are stored in area 276 of RAM 206 . The two-dimensional map and/or the three dimensional map is displayed on LCD 201 ( FIG. 1 ) (S 3 ). As another embodiment of the present invention the attribution data stored in area 295 of RAM 206 may be utilized. Namely if any road block, traffic accident, road construction, and/or traffic jam is included in the shortest route calculated by the method mentioned above, CPU 211 calculates the second shortest route to the destination. If the second shortest route still includes road block, traffic accident, road construction, and/or traffic jam CPU 211 calculates the third shortest route to the destination. CPU 211 calculates repeatedly until the calculated route does not include any road block, traffic accident, road construction, and/or traffic jam. The shortest route to the destination is highlighted by a significant color (such as red) to enable the user of communication device 200 to easily recognize such route on LCD 201 .
As another embodiment of the present invention an image which is similar to the one which is observed by the user in the real world may be displayed on LCD 201 ( FIG. 1 ) by using the three-dimensional object data. In order to produce such image CPU 211 ( FIG. 1 ) identifies the present location and retrieves the corresponding location data from area 277 of RAM 206 ( FIG. 65 ). Then CPU 211 retrieves a plurality of object data which correspond to such location data from area 276 or RAM 206 ( FIG. 65 ) and displays a plurality of objects on LCD 201 based on such object data in a manner the user of communication device 200 may observe from the current location.
FIG. 71 illustrates the sequence of updating the shortest route to the destination while communication device 200 is moving. By way of periodically and automatically inputting the current position by the method so-called โglobal positioning systemโ or โGPSโ as described above the current position is continuously updated (S 1 ). By utilizing the location data of streets and traffic lights and other relevant data CPU 211 recalculates the shortest route to the destination (S 2 ). CPU 211 then retrieves the relevant two-dimensional map data which should be displayed on LCD 201 from area 275 of RAM 206 ( FIG. 65 ) (S 3 ). As another embodiment of the present invention by way of utilizing the location data stored in 277 CPU 211 may produce a three-dimensional map by composing the three dimensional objects by method so-called โtexture mappingโ which are stored in area 276 of RAM 206 ( FIG. 65 ). The two-dimensional map and/or the three-dimensional map is displayed on LCD 201 ( FIG. 1 ) (S 4 ). The shortest route to the destination is re-highlighted by a significant color (such as red) to enable the user of communication device 200 to easily recognize the updated route on LCD 201 .
FIG. 72 illustrates the method of finding the shortest location of the desired facility, such as restaurant, hotel, gas station, etc. The voice recognition system is activated in the manner described in FIG. 67 (S 1 ). By way of utilizing the system a certain type of facility is selected from the options displayed on LCD 201 ( FIG. 1 ). The prepared options can be a) restaurant, b) lodge, and c) gas station (S 2 ). Once one of the options is selected CPU 211 ( FIG. 1 ) calculates and inputs the current position by the method described in FIG. 68 and/or FIG. 71 (S 3 ). From the data selected in S 2 CPU 211 scans area 277 or RAM 206 ( FIG. 65 ) and searches the location of the facilities of the selected category (such as restaurant) which is the closest to the current position (S 4 ). CPU 211 then retrieves the relevant two-dimensional map data which should be displayed on LCD 201 from area 275 of RAM 206 ( FIG. 65 ) (S 5 ). As another embodiment of the present invention by way of utilizing the location data stored in 277 CPU 211 may produce a three-dimensional map by composing the three dimensional objects by method so-called โtexture mappingโ which are stored in area 276 of RAM 206 ( FIG. 65 ). The two-dimensional map and/or the three dimensional map is displayed on LCD 201 ( FIG. 1 ) (S 6 ). The shortest route to the destination is re-highlighted by a significant color (such as red) to enable the user of communication device 200 to easily recognize the updated route on LCD 201 . The voice recognition system is deactivated thereafter (S 7 ).
FIG. 73 illustrates the method of displaying the time and distance to the destination. As illustrated in FIG. 73 CPU 211 ( FIG. 1 ) calculates the current position where the source data can be input from the method described in FIG. 68 and/or FIG. 71 (S 1 ). The distance is calculated from the method described in FIG. 70 (S 2 ). The speed is calculated from the distance which communication device 200 has proceeded within specific duration of time (S 3 ). The distance to the destination and the time left are displayed on LCD 201 ( FIG. 1 ) (S 4 and S 5 ).
FIG. 74 illustrates the method of warning and giving instructions when the user of communication device 200 deviates from the correct route. By way of periodically and automatically inputting the current position by the method so-called โglobal positioning systemโ or โGPSโ as described above the current position is continuously updated (S 1 ). If the current position deviates from the correct route (S 2 ) warnings are given from speaker 216 ( FIG. 1 ) and/or LCD 201 ( FIG. 1 ) (S 3 ). The method described in FIG. 74 is repeated for certain period of time. If the deviation still exists after such period of time has passed CPU 211 ( FIG. 1 ) initiates the sequence described in FIG. 70 and calculates the shortest route to the destination and display on LCD 201 . The details of such sequence is as same as the one explained in FIG. 70 .
FIG. 74 a illustrates the overall operation of communication device 200 regarding the navigation system and the communication system. When communication device 200 receives data from antenna 218 (S 1 ) CPU 211 ( FIG. 1 ) determines whether the data is navigation data, i.e., data necessary to operate the navigation system (S 2 ). If the data received is a navigation data the navigation system described in FIG. 67 through FIG. 74 is performed (S 3 ). On the other hand, if the data received is a communication data (S 4 ) the communication system, i.e., the system necessary for wireless communication which is mainly described in FIG. 1 is performed (S 5 ).
Remote Controlling System
FIG. 75 through FIG. 83 illustrates the remote controlling system of communication device 200 .
As illustrated in FIG. 75 communication device 200 is connected to network NT. Network NT may be the internet or have the same or similar structure described in FIG. 2 a , FIG. 2 b and/or FIG. 2 c except โdevice Bโ is substituted to โsub-host SHโ in these drawings. Network NT is connected to sub-host SH in a wireless fashion. Sub-host SH administers various kinds of equipment installed in building 801 , such as TV 802 , microwave oven 803 , VCR 804 , bathroom 805 , room light 806 , AC 807 , heater 808 , door 809 , and CCD camera 810 . Communication device transfers a control signal to sub-host SH via network NT, and sub-host SH controls the selected equipment based on the control signal.
As illustrated in FIG. 76 communication device 200 is enabled to perform the remote controlling system when the device is set to the home equipment controlling mode. Once communication device 200 is set to the home equipment controlling mode, LCD 201 ( FIG. 1 ) displays all pieces of equipment which are remotely controllable by communication device 200 . Each equipment can be controllable by the following method.
FIG. 77 illustrates the method of remotely controlling TV 802 . In order to check the status of TV 802 a specific signal is input from input device 210 ( FIG. 1 ) and communication device 200 thereby sends a check request signal to sub-host SH via network NT. Sub-host SH, upon receiving the check request signal, checks the status of TV 802 , i.e., the status of the power (ON/OFF), the channel, and the timer of TV 802 (S 1 ), and returns the results to communication device 200 via network NT, which are displayed on LCD 201 (S 2 ). Based on the control signal produced by communication device 200 , which is transferred via network NT, sub-host SH turns the power on (or off) (S 3 a ), selects the channel (S 3 b ), and/or sets the timer of TV 802 (S 3 c ). The sequence of S 2 and S 3 can be repeated (S 4 ).
FIG. 78 illustrates the method of remotely controlling microwave oven 803 . In order to check the status of microwave oven 803 a specific signal is input from input device 210 ( FIG. 1 ) and communication device 200 thereby sends a check request signal to sub-host SH via network NT. Sub-host SH, upon receiving the check request signal, checks the status of microwave oven 803 , i.e., the status of the power (ON/OFF), the status of temperature, and the timer of microwave oven 803 (S 1 ), and returns the results to communication device 200 via network NT, which are displayed on LCD 201 (S 2 ). Based on the control signal produced by communication device 200 , which is transferred via network NT, sub-host SH turns the power on (or off) (S 3 a ), selects the temperature (S 3 b ), and/or sets the timer of microwave oven 803 (S 3 c ). The sequence of S 2 and S 3 can be repeated (S 4 ).
FIG. 79 illustrates the method of remotely controlling VCR 804 . In order to check the status of VCR 804 a specific signal is input from input device 210 ( FIG. 1 ) and communication device 200 thereby sends a check request signal to sub-host SH via network NT. Sub-host SH, upon receiving the check request signal, checks the status of VCR 804 , i.e., the status of the power (ON/OFF), the channel, the timer, and the status of the recording mode (e.g., one day, weekdays, or weekly) of VCR 804 (S 1 ), and returns the results to communication device 200 via network NT, which are displayed on LCD 201 (S 2 ). Based on the control signal produced by communication device 200 , which is transferred via network NT, sub-host SH turns the power on (or off) (S 3 a ), selects the channel (S 3 b ), sets the timer (S 3 c ), and/or selects the recording mode of VCR 804 (S 3 d ). The sequence of S 2 and S 3 can be repeated (S 4 ).
FIG. 80 illustrates the method of remotely controlling bathroom 805 . In order to check the status of bathroom 805 a specific signal is input from input device 210 ( FIG. 1 ) and communication device 200 thereby sends a check request signal to sub-host SH via network NT. Sub-host SH, upon receiving the check request signal, checks the status of bathroom 805 , i.e., the status of bath plug (or stopper for bathtub) (OPEN/CLOSE), the temperature, the amount of hot water, and the timer of bathroom 805 (S 1 ), and returns the results to communication device 200 via network NT, which are displayed on LCD 201 (S 2 ). Based on the control signal produced by communication device 200 , which is transferred via network NT, sub-host SH opens (or closes) the bath plug (S 3 a ), selects the temperature (S 3 b ), selects the amount of hot water (S 3 c ), and/or sets the timer of bathroom 805 (S 3 d ). The sequence of S 2 and S 3 can be repeated (S 4 ).
FIG. 81 illustrates the method of remotely controlling AC 807 and heater 808 . In order to check the status of AC 807 and/or heater 808 a specific signal is input from input device 210 ( FIG. 1 ) and communication device 200 thereby sends a check request signal to sub-host SH via network NT. Sub-host SH, upon receiving the check request signal, checks the status of AC 807 and/or heater 808 , i.e., the status of the power (ON/OFF), the status of temperature, and the timer of AC 807 and/or heater 808 (S 1 ), and returns the results to communication device 200 via network NT, which are displayed on LCD 201 (S 2 ). Based on the control signal produced by communication device 200 , which is transferred via network NT, sub-host SH turns the power on (or off) (S 3 a ), selects the temperature (S 3 b ), and/or sets the timer of AC 807 and/or heater 808 (S 3 c ). The sequence of S 2 and S 3 can be repeated (S 4 ).
FIG. 82 illustrates the method of remotely controlling door 809 . In order to check the status of door 809 a specific signal is input from input device 210 ( FIG. 1 ) and communication device 200 thereby sends a check request signal to sub-host SH via network NT. Sub-host SH, upon receiving the check request signal, checks the status of door 809 , i.e., the status of the door lock (LOCKED/UNLOCKED), and the timer of door lock (S 1 ), and returns the results to communication device 200 via network NT, which are displayed on LCD 201 (S 2 ). Based on the control signal produced by communication device 200 , which is transferred via network NT, sub-host SH locks (or unlocks) the door (S 3 a ), and/or sets the timer of the door lock (S 3 b ). The sequence of S 2 and S 3 can be repeated (S 4 ).
FIG. 83 illustrates the method of CCD camera 810 . In order to check the status of CCD camera 810 a specific signal is input from input device 210 ( FIG. 1 ) and communication device 200 thereby sends a check request signal to sub-host SH via network NT. Sub-host SH, upon receiving the check request signal, checks the status of CCD camera 810 , i.e., the status of the camera angle, zoom and pan, and the timer of CCD camera 810 (S 1 ), and returns the results to communication device 200 via network NT, which are displayed on LCD 201 (S 2 ). Based on the control signal produced by communication device 200 , which is transferred via network NT, sub-host SH selects the camera angle (S 3 a ), selects zoom or pan (S 3 b ), and/or sets the timer of CCD camera 810 (S 3 c ). The sequence of S 2 and S 3 can be repeated (S 4 ).
FIG. 84 illustrates the overall operation of communication device 200 regarding the remote controlling system and communication system. CPU 211 ( FIG. 1 ) periodically checks the input signal from input device 210 ( FIG. 1 ). If the input signal indicates that the remote controlling system is selected (S 2 ) CPU 211 initiates the process for the remote controlling system (S 3 ). On the other hand, if the input signal indicates that the communication system is selected (S 4 ) CPU 211 initiates the process for the communication system.
FIG. 85 is a further description of the communication performed between sub-host SH and door 809 which is described in FIG. 82 . When sub-host SH receives a check request signal as described in FIG. 82 sub-host SH sends a check status signal which is received by controller 831 via transmitter 830 . Controller 831 checks the status of door lock 832 and sends back a response signal to sub-host SH via transmitter 830 indicating that door lock 832 is locked or unlocked. Upon receiving the response signal from controller 832 sub-host SH sends a result signal to communication device 200 as described in FIG. 82 . When sub-host SH receives a control signal from communication device 200 as described in FIG. 82 it sends a door control signal which is received by controller 831 via transmitter 830 . Controller 831 locks or unlocks door lock 832 in conformity with the door control signal. As another embodiment of the present invention controller 831 may owe the task of both sub-host SH and itself and communicate directly with communication device 200 via network NT.
As another embodiment of the present invention each equipment, i.e., TV 802 , microwave oven 803 , VCR 804 , bathroom 805 , room light 806 , AC 807 , heater 808 , door lock 809 , and CCD camera 810 , may carry a computer which directly administers its own equipment and directly communicates with communication device 200 via network NT instead of sub-host SH administering all pieces of equipment and communicate with communication device 200 .
The above-mentioned invention is also applicable to carriers in general, such as automobiles, airplanes, space shuttles, ships, motor cycles and trains.
Auto Emergency Calling System
FIG. 86 and FIG. 87 illustrate the automatic emergency calling system.
FIG. 86 illustrates the overall structure of the automatic emergency calling system. Communication device 200 is connected to network NT. Network NT may be the internet or have the same or similar structure described in FIG. 2 a , FIG. 2 b and/or FIG. 2 c . Network NT is connected to automobile 835 thereby enabling automobile 835 to communicate with communication device 200 in a wireless fashion. Emergency center EC, a host computer, is also connected to automobile 835 in a wireless fashion via network NT. Airbag 838 which prevents persons in automobile 835 from being physically injured or minimizes such injury in case traffic accidents occur is connected to activator 840 which activates airbag 838 when it detects an impact of more than certain level. Detector 837 sends an emergency signal via transmitter 836 when activator 840 is activated. The activation signal is sent to both emergency center EC and communication device 200 . In lieu of airbag 838 any equipment may be used so long as such equipment prevents from or minimizes physical injuries of the persons in automobile 835 .
FIG. 87 illustrates the overall process of the automatic emergency calling system. Detector 837 periodically checks activator 840 (S 1 ). If the activator 840 is activated (S 2 ) detector 837 transmits an emergency signal via transmitter 836 (S 3 a ). The emergency signal is transferred via network NT and received by emergency center EC and by communication device 200 (S 3 b ).
As another embodiment of the present invention the power of detector 837 may be usually turned off, and activator 840 may turn on the power of detector 837 by the activation of activator 840 thereby enabling detector 837 to send the emergency signal to both emergency center EC and to communication device 200 as described above.
This invention is also applicable to any carriers including airplanes, space shuttles, ships, motor cycles and trains.
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The wireless communication device and the method thereof which implements the 1st function and the 2nd function; when the 1st function is implemented, the video image generator processes a plurality of two-dimensional images and the plurality of two-dimensional images are displayed on the display, and when the 2nd function is implemented, the video image generator processes a plurality of two-dimensional images and a plurality of three-dimensional images, both of which are displayed on the display.
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This is a continuation of application Ser. No. 07/544,317 filed Jun. 24, 1990, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an apparatus and a method for the adhesive fixing of at least one part, which is to be fixed to a workpiece made from an elastic, resilient and, in particular, material.
2. Prior Art
In the case of elastic, resilient workpieces not directly supportable from the side remote from the joining side against the joining pressure, such as plastic fuel containers produced in the extrusion blowing process and made in particular of higher molecular weight polyethylene, it is difficult to obtain an adequate quality of the connection to the joining part. However, this quality is often of decisive importance, because fuel containers can leak in the joining area. The joining quality is not only dependent on possible deformations of the workpiece during attachment, but also on manufacturing tolerances, which in the case of containers of the aforementioned type are approximately +/-0.5% and therefore very high. Attempts have already been made to compensate these manufacturing tolerances with the aid of a process and an apparatus according to German patent 35 37 670. In this case, prior to the start of a preheating process for plasticizing the workpiece, the position of the joining point is measured in low force manner at the joining point, and as a function of the measured result, the infeeding of a welding unit and the joining part are adjusted via welding stops.
However, no account is taken of the fact that the workpiece, under the pressure of the welding unit and the joining part, resiliently gives way in the vicinity of the joining point and that this does not occur as a parallel displacement, but as a tilting slope, as a function of the position of the joining point. It is also not possible to take account of this deflection as a constant value for similar workpieces, because the deflection is dependent on the wall thickness of the workpiece, manufacturing tolerances, and its ageing state. Less aged workpieces are softer and give way more than more greatly aged workpieces. Thus, the joining quality cannot be improved with the known apparatus and method.
SUMMARY ON THE INVENTION
An object of the invention is to provide an apparatus and a method of the aforementioned type making it possible to avoid the disadvantages of known solutions and permitting the fitting of joining parts with constant quality to workpieces which are elastically flexibly resilient in the vicinity of the joining point.
According to the invention, this object is achieved by an apparatus of the aforementioned type in that a compensating device is provided for the at least partial or substantial elimination of positional changes, which the joining zone has under compressive loads and which occur during an operation either in preparation for the joining process or during the actual joining or both. The device makes it possible to optionally simultaneously determine and eliminate variation due to the manufacturing tolerances. It is also possible to provide separate compensating devices for the amount of resilience and for the nature of the resilience, e.g. a possible tilting of the joining zone.
Appropriately, the arrangement is such that the resilience of the joining zone is not prevented by pneumatic positional securing, but is instead determined by the compensating device immediately in the vicinity of or at the joining zone, and preference is given to a determination by mechanical contact as opposed to non-contact determination. In all cases, as a result of the inventive construction, it is possible to carry out a compressive loading preparation of the joining point for the joining process and a pressing of the joining part during the joining process uninfluenced by the extent and the nature of the position change by which the joining point gives way under the compressive load.
It is admittedly conceivable to provide the inventive apparatus and method, e.g. for adhesive fixtures, by bonding, cold welding, etc., but the preferred use is in fixing by welding, in which the surfaces to be joined together of both the workpiece and the joining part are plasticized by heating to a predetermined depth and, then in the plasticized state, are pressed into one another over a predetermined depth, and after which, cooling takes place for solidifying the joining zone. The inventive construction is also suitable for solid section workpieces, which are elastically resilient like rubber.
Appropriately, according to the invention, a positional sensor for determining the position of the joining point of the workpiece is positioned as close as possible to the joining point and is applied to the associated workpiece surface with such a limited force that the latter does not lead to a yielding positional change of the joining point. Instead, said positional change is brought about under a compressive load by using a separate prestressing device and which is substantially the same as that of a preparatory operation or the actual joining process, so that the prestressing device can be directly formed by the heating device. Using said heating device, the workpiece joining point is preferably suddenly subjected to a predetermined operating pressure, in such a way that it assumes a prestressed yielding position corresponding to said working pressure and which is then determined by the positional sensor as a base value. On the basis of this base value, it is then possible to determine and automatically control the abrasion of the surface of the joining point, e.g. by melting or the penetration of the joining surface of the joining part into the joining point of the workpiece.
If a preparatory adapting process is provided for leveling or smoothing the generally relatively rough or uneven surface of the joining point of the workpiece, and during which, said joining point is loaded with a relatively high contact pressure, then appropriately, there is a determination of the position at the start of this compressive loading, namely, prior to the start of the adapting process, by means of a reference point associated with the joining point. After carrying out the adapting process, the compressive loading is suddenly reduced, so that now, and without the heating unit carrying out the adapting process of penetrating further into the surface of the joining point, the latter is plasticized by heating to a predetermined depth and the joining point can carry with it the heating unit accompanied by the restoring deformation of the workpiece.
While the depth of penetration into the joining point during the adapting process can be measured and controlled by the positional sensor, the plasticizing or preheating process can be controlled in a time-dependent manner. The path or displacement measurement at the start of the adapting process, particularly in the case of a hydraulic drive for the infeeding of the heating unit, is preferably initiated by means of an adjustable pressure switch, which on reaching a given compressive load at which the joining point no longer gives way, is switched over to initiate the path or displacement measurement.
In place of or in addition to the aforementioned adapting or compensating device, it is also advantageous to provide such a device, which further determines any tilting position changes or inclination motion of the joining point under compressive loading, e.g. during the adapting process and/or during the joining process and substantially eliminates the same. This can particularly easily be obtained in that the pressure-loading component is constructed so as to follow in self-adjusting manner the tilting position changes of the joining point. The component can be pivotably mounted about an axis roughly parallel to the joining point infeed direction. This axis is appropriately at right angles to the direction in which the joining point performs the greatest tilting position changes or can assume the greatest inclinations as a result of the mechanical strength ratios of the workpiece. The at least one, or preferably single, positional sensor is advantageously arranged in such a way that it measures in the vicinity of the point were the joining point performs a relatively minimal deflection. Particularly, the positional sensor measures in a plane defined by a line in the axial direction of the device and a pivot axis of a self-adjustment mechanism of the device, said axially plane being oriented roughly at right angles to the surface of the joining point and parallel to the direction of the motion for performing the joining contact.
The invention also proposes a method for the adhesive fixing of at least one joining part, in which at least one operation, e.g. an adapting process or a joining process is performed under compressive loading, the joining point initially being deflected with a compressive load roughly corresponding to joining or adapting compressive load and the maximum deflection position occurring being determined and then the working process being performed in a path or displacement-dependent manner. Thus, the actual working process can be very accurately performed independently of the resilience of the joining point.
Advantageously using the same tool the joining point is adapted under pressure and plasticized in a substantially pressure-free manner, the same tool being usable for plasticizing the joining surface of the joining part on a side of the tool remote from the workpiece.
A particularly advantageous development, especially of a method of the aforementioned type, is obtained in that the joining pressure occurring during the joining process is determined and is related to the joining path for obtaining a test value. The path measuring system can be used for checking the position of the joining part with respect to the joining point or the reference point at the end of the joining process for its production consistency and to process the corresponding values for quality securing measures. The path-dependent control of the joining process is in particular possible when the apparatus is constructed in numerically controlled manner and the extent of the joining path, measured on the path transducer is predetermined. The force to be applied during the joining process for displacing the melt of the plasticized material can be measured and further processed for quality securing purposes. In this case as the measuring device a corresponding force transducer is influenced by the pressing unit moving the joining tool.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further features of preferred developments of the invention can be gathered from the claims, drawings and description, in which the individual features can be realized singly or in the form of sub-combinations in an embodiment of the invention and in other fields and can represent advantageously, independently protectable constructions for which protection is hereby claimed. An embodiment of the invention is described hereinafter relative to the drawings, wherein:
FIG. 1 shows the inventive apparatus in a simplified representation.
FIG. 2 shows a side view of the apparatus according to FIG. 1.
FIGS. 3 to 5 show successive operating phases of the apparatus in a side view according to FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus 1 according to FIGS. 1 to 5 has a frame 2 for the vertical mounting of an underlying slide 3 with guides 4, which can be bar guides. A drive 5 arranged on the frame 2 and which can be formed by a hydraulic or pneumatic working cylinder is used for the displaceable mounting of the slide 3. Between the drive 5 or its piston rod and the slide 3 can be provided a force measuring element or force transducer 6, by means of which the compressive force or torque acting on the slide 3 is determined and by means of a signal line is transmitted to a control device or the like.
On the underside of the slide 3, in the form of a press ram or punch, a joining tool 7 is easily interchangeably fixed by means of a mounting support 8. Below the tool 7 is provided in weight-compensated manner a heating unit 9 of a heating device, which can be laterally displaced with respect to the slide 3 and the joining tool 7, so that it is located in one position in its working area or immediately below the same and in another position laterally outside the working area.
The apparatus 1 is used for attaching a joining part 11 indicated in dot-dash line manner in FIGS. 1 to 5 to an also dot-dash line indicated workpiece 10 by means of heated tool welding. The workpiece 10 is a tank produced by an extrusion blowing process from higher molecular weight polyethylene and which is initially completely closed and from which, after shaping, the waste is removed, followed by weighing and then the cutting out of at least one bore, filling opening or the like. Appropriately, in the same tool fixing, in which these operations are performed, the at least one joining part 11 is attached, and this part 11 can form a smaller filling connection, venting nipple, mounting support for fixing the tank or the like compared with the workpiece 10. The joining part 11 is adhesively fixed to an outside of a wall 12 of the workpiece 10 in the vicinity of a flat joining point 13, which can e.g. closely surround in annular manner a wall bore 14. With the joining point 13 is associated a substantially identically large joining surface 15 on the side of the joining part 11 to be attached and which with the joining point 13 in the joined state determines the joining plane 16 located in a workpiece surface 17. The joining part 11 is appropriately formed by an injection molded part from a similar weldable material to the workpiece 10. As close as possible to the outer circumferential boundary of the joining point 13, a very small area reference point 18 is determined on the workpiece surface 17 for the relative path measurement between the joining point 13 and the tool unit to be engaged therewith in the joining direction of arrow 19.
The joining point 13 or the wall 12 is, in the case of heating element welding, loaded with welding pressures or forces applied by a prestressing device directed at right angles to the joining plane 16 and which are approximately 3 to 5 kp/cm 2 . Under these forces and as indicated in FIGS. 2, 4 and 5, the wall elastically gives way in the direction of arrow 19, i.e. in the direction of its inside. This not only leads to a change in its position relative to a reference plane of the apparatus frame 2 roughly at right angles to arrow 19, but also the joining point 13, due to its different spacings with respect to adjacent transverse walls, can simultaneously pivot relative to said reference plane by a few radians into a tilting position, so that it is no longer in a plane at right angles to the infeed or joining direction of arrow 19 and instead a tilted welding or joining plane 16 is obtained. For compensating the give-way distance of joining point 13, a compensating device 20 is provided. According to the invention, the device 20 can be formed by rigid stops or could have such stops, which are located on the heating unit 9 and on the joining tool 7, and in the case of heated tool welding, can be supported at the end of the adapting process or at the start of the preheating or plasticizing process in the vicinity of the then larger surface reference point of the workpiece surface 17, while the stops of the joining tool 7 are then correspondingly supported at the reference point. Thus, in both operations, the position of the tool unit could be established with respect to the joining point 13 independently of the extent of the yielding of the wall 12 having the joining point 13.
Appropriately, the compensating device 20 has control device 22 which, besides the force transducer 6, is also influenced by a measuring device 26, which with the aid of a measuring member 27 determines the position of the reference point 18 under said compressive loading of the wall 12 and simultaneously any tolerance differences in the workpiece height parallel to joining direction arrow 19. The measuring or determining member 27 can have a pin-like positional sensor 28 displaceable relative to a sensor mounting support 29 in the direction of arrow 19 and whose end determines the position of the joining point 13 by mechanical sensing of the reference point 18. The sensor mounting support 29 can be fed in with the slide 3 counter to the joining point 13 and is then adjustable for path measurement during the joining process counter to arrow 19 with respect to slide 3. However, it can also be displaceably mounted on the frame 2, so that at the start of the adapting process, it can be fed in with the slide 3 against joining point 13 and then up to the end of the joining process is fixed relative to the frame 2 and during the entire time the positional sensor 28 remains in engagement with the reference point 18.
The heating unit 9 has a flat heating element 25 which can be operated with an electrical resistance heating means and on whose underside is provided a heat conducting, plate-like heating member 23 for heating the joining point 13 during the adapting process and also during the plasticizing process and on whose top is provided a heat conducting, plate-like heating member 24 for plasticizing and optionally for prior surface adaptation of the joining surface 15 of the joining part 11. The end position of the joining tool 7 for the positionally secured reception of the joining part 11 with respect to the heating member 24 in the direction of arrow 19 is rigidly fixed by stops 30 and by counterstops 31, which are provided on the facing sides of the joining tool 7 and the heating member 24 close to the outer circumference of the joining surface 15. Optionally, the stops 30 of the joining tool 7 could also compensate the resilience during the joining process in the described manner, but are appropriately arranged in such a way that they remain contact-free with respect to the workpiece 10 or the workpiece surface 17 during the joining process.
The positional sensor 28 acts on a transducing element 35, e.g. an inductively operating displacement transducer, which acts by means of a signal line on the same control device 22 as the force transducer 6. This control device 22 acts via a control line on a valve control mechanism 36 for the pressurizing and pressure relief of the drive 5, said control mechanism 36 appropriately having pressure proportional valves making it possible to automatically set the different pressures and forces for the adapting process, the preheating or plasticizing process and the joining process which are advantageous for an optimum welding operation, and by means of a voltage, the pressure from the pressure source 37 is correspondingly controlled.
For attaching a joining part 11 to the joining point 13 of a workpiece 10, the joining part 11 is inserted in the joining tool 7 and then the heating unit 9 is brought from the position according to FIG. 3 from a side located outside the positional sensor 28 into its working position between the joining tool 7 and the joining point 13. The pressing unit having the slide 3 is moved with the joining tool 7 against the heating unit 9, which is also movable in the direction of arrow 19 and is appropriately hydraulically or pneumatically operated.
A pressure loading component presses the heating unit with a clearly defined adapting force, adjustable by means of a pressure proportional valve, against the joining point 13, which gives way dependently of said force until a state of equilibrium is reached. During the infeed of the pressing unit, the positional sensor 28 rests on the reference point 18. On reaching the state of equilibrium a pressure builds up in the pressure system and is processed by means of an adjustable pressure switch for initiating the path or displacement measurement.
The path or relative movement of the heating unit 9 with respect to the reference point 18 of the workpiece surface 17 in infeed direction 19 is now measured. This measurement takes place independently of the deformation of the wall 12 during the force application during the compensating process. For technical and economic reasons, this force is made relatively high, so that the compensating process can be performed as quickly as possible.
The amount by which the joining point 13 is melted during the compensating or adapting process is predetermined on the basis of the unevennesses of the workpiece surface 17 in the vicinity of the joining point 13, established by statistical measurements and increased by a safety allowance of a few 1/10 mm, so that there can be a melting amount of less than 1 mm, e.g. 0.8 mm. This melting amount is stored and can be adjusted on the path measuring system, e.g. on the control device 22.
If the heating unit 9 has covered the path corresponding to this melting amount, the hydraulic pressure on the proportional valve is reversed, namely reduced in such a way that the heat of the heating member 23 can penetrate the lower layers of the wall, e.g. over roughly 1 mm while plasticizing the material, without any displacement of the material melt formed.
As a result of the reduced pressing pressure, the aforementioned state of equilibrium no longer exists, and the joining point 13 or the wall 12 returns, under its restoring force, by a corresponding amount towards its relaxed starting state until once again a state of equilibrium corresponding to the reduced pressure is reached. The joining point 13 carries the pressing unit with it, whereas the sensor mounting support 29 remains fixed with respect to the frame 2 or the workpiece receptacle due to its location, so that the positional sensor 28 can determine the return path of the almost pressureless wall 12 with respect to the heating member 23. Despite the new state of equilibrium, there is still a certain after-run or a further slight return of the workpiece, which is also determined by the path measuring system.
As the joining parts 11 generally have very small manufacturing tolerances, the melting amount thereof during the compensating process of the joining surface 15 can be added as a fixed amount to the path measurement. The path of the joining part 11 relative to the heating member.24 during this adapting process is determined by the adjustable stops 30, 31, which can e.g. be formed by stop screws parallel to the joining direction of arrow 19.
The plasticizing or preheating of the joining point 13 or the joining surface 15 is controlled in a time-dependent manner, e.g. by means of an adjustable clock and the plasticized depth in the wall 12 or in the joining part 11 can be determined via the duration of the preheating time and via the temperature of the heating member 23 or 24. At the end of this time the pressing unit returns from the infeed position according to FIG. 4 into a starting position and the heating unit 9 travels at right angles thereto in a pivoting movement out of the joining area into its starting position according to FIGS. 3 and 5.
The hydraulic pressure of the drive 5 for the pressing unit is reversed to welding or joining pressure, i.e. increased, so that the joining tool 7 with the joining part 11 runs up on to the joining point 13 and under said force presses against the wall 12 and the material melts of the joining point 13 and the joining surface 15 penetrate one another. This compressive loading can lead to a different deformation of the wall 12 or resilience of the joining point 13 as compared with the adapting process and the extent by which the melts penetrate one another can be determined via positional sensor 28 and can be fixed by the control mechanism. However, the path measuring system can also be used for checking the position between the joining point 11 and the reference point 18 for its manufacturing consistency, particularly if a predetermined joining pressure is used as a basis. The joining tool is a component of a joining means 21 or contacting.
As can also be gathered from FIGS. 1 to 5, appropriately the joining tool 7 is self-adjustably pivotably mounted by a few radians on mounting support 8 about a pivot axis 32 roughly parallel to the joining plane 16 or at right angles to the joining direction 19. The pivot axis 32 is roughly in the center of the extension of the joining tool 7 which is at right angles thereto. The heating unit 9 or at least the heating member 23 is self-adjustably pivotable with respect to a not shown mounting support about a pivot axis 33 located roughly parallel to the pivot axis 32 and in the associated median plane of the heating members 23, 24. The two pivot axes 32, 33 are appropriately as close as possible to one another or in the vicinity of the facing sides of the joining tool 7 and the heating unit 9, as well as close as possible to the plane of the joining surface 15 or at the heating surface of the heating member 23. The positional sensor 28 or the reference point 18 with respect to the position of the joining tool 7 or the heating unit 9 are so selected that they are located on the side of these components traversed by the pivot axes or pins 32, 33, preferably roughly in the common axial plane of the pivot axes 32, 33 parallel to arrow 19. The position of the pivot axes 32, 33 with respect to the workpiece 10 or the wall 12 is appropriately chosen in such a way that the pivot axes 32, 33 are at right angles to the direction in which the joining point 13 can assume the greatest tilting slope on giving way or yielding.
As shown in FIG. 4, during the compensating process, the heating member 23 can be self-adjustably influenced by the joining point 13 and can also slope the same, so that there is a constant specific contact pressure over the entire extension of the joining point 13. Thus, the heating unit 9 is sloped parallel to the joining tool 7, so that the relative position between these two components is not influenced by said tilting position. In the same way, during the joining process according to FIG. 5, the joining tool 7 can alone slope in self-adjusting manner, so that the joining pressure between the joining point 13 and the joining surface 15 is distributed in a constant manner over the extension thereof.
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An apparatus for the adhesive fixing of a joining part (11) to a resilient workpiece joining point (13) function in such a way that by means of a compensating device (20) the yielding of the joining point (13) is determined according to distance and/or position change and is taken into account during the smoothing adapting of the joining point (13) and during the attachment of the joining part (11) and consequently eliminated. This makes it possible to obtain a high joining quality and constancy.
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This is a continuation of application Ser. No. 401,963, filed Sept. 28, 1973, and now abandoned, which is a continuation of application Ser. No. 187,058, filed Oct. 6, 1961, and now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to improvements in sectional and detachable, hermetically sealed, protective covers, to be used in roofs, walls, floor structures, for substituting soffit scaffolding, in the construction of silos, vaults, tanks, retention walls, etc.
Covers of this type presently on the market have the disadvantage of requiring perforation to accommodate anchor means by which they must be attached to structures providing support therefor. The attendant increase in labor and irregularity in the impermeability of existing covers of this type, their high weight, especially if it is necessary to cover large surfaces are additional disadvantages. The present invention is intended to eliminate all these inconveniences mentioned in connection with known covers of this type.
SUMMARY OF THE INVENTION
This invention relates to hermetical covers that are characterized in that they are constituted by units formed of sheets or cast, forged or founded pieces which may be placed in juxtaposition, joined by means of lateral clips with which they are provided. They may be placed horizontally, vertically or in inclinations, according to the requirements of the work or construction wherein they are employed.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view in perspective of the preferred embodiment of the covering assembly according to this invention,
FIG. 2 is an end view in elevation of the assembly of FIG. 1 showing supplemental anchoring means to provide added rigidity to the assembly of the present invention;
FIG. 3 is a view in perspective of an alternative arrangement of the assembled sections according to this invention;
FIG. 4 is an end view in elevation of the assembly of FIG. 3 showing the anchoring means therefor; and
FIGS. 5-8 show various forms which the sectional cover members may take according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
The units which together form the cover 10 are constituted by cast or forged pieces 11, having a generally rectangular shape, as seen in FIG. 1. Each sheet or piece 11 includes a surface with a series of corrugations 12 extending transversely. Alternatively, a series of corrugations 22 may extend diagonally in the surface of a piece 21 as shown in FIG. 8. Also, a combination of corrugations in various directions may be provided in piece 31 according to FIG. 5. Such corrugations 32 may extend from one side to the other, of the flat surface of the cover. Moreover, such corrugations as 42 or 52 may reach to the edge of the sheet 41 or 51, respectively, and form part of the fold or bend 44 or 54 as shown in FIGS. 6 and 7, to effect a reinforcement therefore, transmit the stress towards the lips 43 or 53 extending at both sides of the pieces 41 or 41 corresponding to lip 13 of piece 51 of FIG. 1. Such features serve a double purpose. They serve as a stress-supporting beam as well as a sealing profile.
Amplifying further on the characteristics of channel-like sheets 41 or 51 which are formed with corrugations 42 or 52 thereon, respectively, as seen in FIGS. 6 and 7, it is noted, for example, that because of the longitudinally-spaced, generally traversely extending corrugations 42, channel-like sheet 41 is inherently provided with a significant measure of flexibility whereby it may be readily deformed in a direction normal to the plane of the longitudinally extending web portion or bottom surface thereof. The corrugations 42 further inherently impart a significant measure of rigidity to sheet 41 to reinforce it against compression loading in the direction in which the corrugations 42 extend both in the web portion of sheet 41 and in the flange portions 44. Similarly, increased resistance to compression loading is provided in the channel-like sheet 51 of FIG. 7 in the web portion thereof as well as in the flange portions 54 and the inwardly directed portions at the upper edges thereof by corrugations 52. Moreover, significantly improved flexibility is imparted to sheet member 51 in the direction normal to the plane of the web portion or bottom surface thereof to facilitate deformation of member 51 whereby it may, for example, be conformed to the surface of a cooperating support member having an arcuate contour. In this connection it is clear that sheet 51 may be readily bent upwardly or downwardly of the plane of the bottom surface thereof and that depending upon the direction of bending, portions of member 51 disposed radially inwardly of the bent member will be in compression while portions disposed radially outwardly of the bent member will be in tension so that deformation of member 51 may be likened to the appearance of an accordion.
This last function is obtained in the following manner: the lip 13 which, per se, is constituted by a semi-circular fold or band 14, or also an angular fold, extending completely along the piece and which results, when placed beside another similar piece, in the formation of a profile having approximately the shape of a T, as seen in FIG. 1, upon which another piece 15 will be placed, which will in length be equivalent to that of the pieces 11 that are going to be joined and which will serve as a protection so as to prevent the passage of the elements towards the interior, and which can have among other shapes that of a semi-cylindrical groove, which at the same time as it covers the joint hermetically, contributes to maintain them in joined relationship.
The principal union is achieved by way of piece 15 which functions as a coupling member and passes over the central part of the two pieces 11 and further surrounds the lips 13 of both pieces like an inverted anchor but without perforating them. Coupling piece 15 thus firmly joins two cover pieces 11 and seals them against water and wind by its being attached to the structure or the corresponding support points. Additionally, anchor screws 16 are provided along the surface of the pieces 11, as shown in FIG. 2, in pressure relationship therewith to effect stiffness and optimum hermeticity in the arrangement. With the cover pieces 11 reinforced by the transverse slots 12 which impart thereto a degree of stiffness along with that provided by coupling piece 15 and anchor screws 16, no additional supplementary anchors such as are used by covers on the market, some of which are attached on the surface, are required.
The anchor screw 16 as seen in FIG. 2 is within the interior of the arrangement of the coupling piece 15 and cover pieces 11. The anchor screw 16 is applied to the cover pieces 11 in combination with an element in the form of a double nail 18, opposite ends of which extend around lips 13 of the cover pieces 11.
The pieces 11 may also be interconnected with a piece 11 disposed by its two lips 13 upwards, while the next piece 11 is hooked thereto its lips 13 downwards, and so on, in a successive manner, until covering the surface as required, as shown in FIG. 3. In this manner, an anchor 17 will be needed having the shape of a hook as shown in FIG. 4, in surrounding relationship with the lip of the piece 11 that is viewing downwards. In case one wishes to impart a higher stiffness and hermeticity to the cover, it is possible to join the pieces by their lips by means of screws, soldering or with rivets, or also by a butt cover strip under pressure. The covers achieved in this manner, will have, among others, the advantages of not permitting the passage of water or other elements to accumulate and effecting a seal requiring neither permeabilizing material packings nor caulking welds.
Thus according to this invention no perforations are needed in the anchor members for the purpose of fixing it to the cover element, as would be useful for locating the anchor in known joints. Further, no transverse union or joint is needed for completing pieces of a certain length, i.e., it is possible to place pieces of a length equal or greater than the distance that exists between the ends of the part to be covered due to its great stiffness. No specific construction or special expansion joints of a supplementary nature are needed, to those formed by the profile of the lips. At the same time this invention permits in joining the lips of the covers that they serve as charge-elements or charge- or load-supporting beams, as a result of which considerably fewer support elements are required so that an economy is obtained both in time and in money. It should be pointed out that the longitudinal lips 13 of each piece 11 will have a camber proportional to the pitch thereof, to the surface to be covered and/or the weight to be supported.
It is to be understood that various changes may be made by those skilled in the art without departing from the scope of the invention, which is not to be considered limited to what is shown in the drawings and described in the specification.
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A hermetically sealable sectional structural cover free of perforations and comprising a longitudinally extending planar web portion with upstanding side flange portions, the flange portions having lateral portions extending inwardly over the web portion from the tops thereof, and corrugations extending transversely along the web portion, along the flange portions and along the lateral portions but terminating short of the free edges of the lateral portions.
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Relevant subject matter is disclosed in the co-pending U.S. patent applications (application Ser. No. 11/956,345, and entitled โINJECTION MOLDING DEVICE;โ application Ser. No. 11/956,347, and entitled โMETHOD FOR ELONGATING FOIL;โ application Ser. No. 11/956,348, and entitled โMETHOD FOR MANUFACTURING A FOIL DECORATED MOLDING;โ application Ser. No. 11/956,350, and entitled โINJECTION MOLDING DEVICEโ), which are filed on the same date Dec. 14, 2007.
BACKGROUND
1. Field of the Invention
The present invention relates to valve devices, and particularly to a valve device of an injection molding device for manufacturing a foil decorated molding.
2. Description of Related Art
Conventionally, various kinds of methods for manufacturing a foil decorated molding, which is molded by an injection molding process and has a transfer layer removed from a substrate foil of a transfer foil and placed on the surface of the molding after the transfer foil is inserted into cavities in an injection mold, have been known in the art. Since the use of the method requires an alignment of the transfer foil along a cavity-forming face of the mold, the transfer foil is preheated before the injection molding process so as to be easily aligned along the cavity-forming face of the mold where the cavity-forming face thereof is greatly recessed or projected from a parting face of the mold.
A traditional injection molding method includes transferring a heater between the male mold and the female mold to heat the foil before matching the molds, and removing the heater after the foil is heated. However, because of the need for the heater and the space it occupies, cost and volume of the injection mold is increased. A new method is used for elongating the foil between the male and female mold by exhausting air from a cavity via the female mold and pressurizing the foil by inputting thermal medium to cause the foil to cling to an inner surface of the cavity of the female mold. However, in this method, the thermal medium cannot be controlled.
What is needed is to provide a valve device for controlling supply of a thermal medium to an injection molding device.
SUMMARY
In one embodiment, a valve device is configured for obturating an opening of a channel defined in an injection molding device. The valve device includes a plug movably received in the channel, and a resilient member connected to the plug. The plug includes an obturating portion for obturating the opening of the channel. The resilient member is configured for driving the plug to its original position where the obturating portion obturates the opening, after the opening of the channel is opened.
Other advantages and novel features of the present invention will become more apparent from the following detailed description of an embodiment when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of an injection molding device having a valve device in accordance with an embodiment of the present invention, together with a foil, the injection molding device including a male mold and a female mold;
FIG. 2 is a cross-sectional view of the female mold, similar to FIG. 1 ;
FIGS. 3 and 4 are enlarged, partially cutaway views of the male mold of FIG. 1 , showing two using states respectively;
FIG. 5 is a cross-sectional view of the female mold of FIG. 1 , but showing the foil extending into the cavity of the female mold;
FIG. 6 is similar to FIG. 1 , but showing the foil extending along an inner surface of the cavity of the female mold and the male and female molds matched together;
FIG. 7 is similar to FIG. 6 , but showing a state after injection; and
FIGS. 8 and 9 are enlarged, partially cutaway views of the male mold in accordance with another embodiment of the present invention, showing two using states respectively.
DETAILED DESCRIPTION
Referring to FIG. 1 , an injection molding device in accordance with an embodiment of the present invention includes a transport 10 for transporting a foil 100 , a mold including a male mold 20 and a female mold 30 , a plurality of pressing members 40 , and a thermal medium source 90 .
The male mold 20 has a projecting part 21 protruding toward the female mold 30 . A plurality of air discharging holes 23 is defined in the male mold 20 around the projecting part 21 and extending from a side, facing the female mold 30 , of the male mold 20 to an opposite side of the male mold 20 . A pressure release valve 80 is connected to each air discharging hole 23 . The pressure release valve 80 is adjustable according to need during molding. A plurality of receiving slots 25 is defined in the male mold 20 in vicinity of edges of the male mold 20 . A plurality of hermetic rings 27 is received in the corresponding receiving slots 25 .
Referring also to FIG. 2 , the female mold 30 defines a cavity 31 therein. The cavity 31 includes a bottom surface A 2 , a first side surface A 1 extending from an edge of the bottom surface A 2 , and a second side surface A 3 extending from an opposite edge of the bottom surface A 2 to a surface that faces the male mold 20 , with an opening formed on the corresponding surface of the female mold 30 . A length of the opening of the cavity 31 is L. A plurality of air discharging holes 32 is defined in the male mold 20 and extending from a side, facing the male mold 20 , of the female mold 30 to an opposite side of the female mold 30 . At least one of the air discharging holes 32 extends from the bottom surface A 2 of the cavity 31 to the corresponding side of the female mold 30 opposite to the male mold 20 . Each air discharging hole 32 is connected to a vacuum-pump at the side of the female mold 30 opposite to the male mold 20 . A plurality of hermetic rings 33 is attached to the female mold 30 adjacent to an edge of the female mold 30 .
Referring also to FIGS. 3 and 4 , the male mold 20 defines a plurality of channels 29 therein extending from a side, facing the female mold 30 , of the projecting part 21 to a side of the male mold 20 opposite to the female mold 30 . Each channel 29 includes a bell-mouthed recessed portion 291 defined in the projecting part 21 facing the female mold 30 , of the projecting part 21 , a conduit 295 defined in the male mold 20 communicating with a small end of the recessed portion 291 , and an L-shaped slender duct 296 with one end communicating with the conduit 295 and the other end passing through the surface opposite to the female mold 30 , of the male mold 20 . A block 298 protrudes in from one end opposite to the recessed portion 291 , of the conduit 295 . One end of a pipe 91 is connected to the end opposite to the female mold 30 , of each slender duct 296 , and the other end of the pipe 91 is connected to the thermal medium source 90 . A through hole is defined in the block 298 .
A valve device is arranged in each channel 29 . In this embodiment, the valve device includes a plug 70 attached in each channel 29 . The plug 70 includes a taper-shaped obturating portion 71 for obturating the recessed portion 291 of the channel 29 , and a pole 73 extending from a small end of the obturating portion 71 . The pole 73 extends through the through hole of the block 298 . A fastening member 75 is fixed to a distal end of the pole 73 . A resilient member 79 , such as a spring, fits about the pole 73 and is resiliently located between the block 298 and the fastening member 75 .
The thermal medium source 90 has thermal medium contained therein, such as thermal liquid or high-pressure gas. In this embodiment, the thermal medium is thermal high-pressure gas. The thermal medium is capable of being heated by an electric heater or an infrared ray heater (IR heater).
The transport 10 includes two transporting rollers 13 and two guiding rollers 15 positioned at two opposite ends of the mold respectively, for transporting the foil 100 into the mold. The foil 100 includes a base layer, and a printed layer attached to the base layer and having printed decorations.
Referring also to FIGS. 5 and 6 , the foil 100 is transported into the mold and between the male and female mold 20 , 30 . The male and female mold 20 , 30 are with the pressing members 40 locked together to form a molding space among the inner surface of the cavity 31 of the female mold 30 , the projecting portion 21 of the male mold 20 , and parts around the projecting portion 21 . The pressing members 40 are received in the corresponding receiving slots 25 , and press the corresponding hermetic rings 27 , 33 to airproof the molding space. The molding space is separated into a first airproof space adjacent to the female mold 30 and a second airproof space adjacent to the male mold 20 by the foil 100 . A vacuum is connected to the air discharging holes 32 of the female mold 30 to vacuumize the first airproof space, thus the foil 100 is sucked toward the first airproof space. The pressure release valve 80 is shut, and the value of the pressure release valve 80 is predetermined according to the molding condition. The thermal medium source 90 inputs heated gas to the channels 29 via the pipes 91 . The plugs 70 are driven by the heated gas to move toward the female mold 30 , therefore the channels 29 open. The heated gas is blown into the second airproof space to press and shape the foil 100 to cling to the inner surface of the cavity 31 of the female mold 30 . The foil 100 is intenerated by the heated gas to cling to the inner surface of the cavity 31 easily.
Referring also to FIG. 7 , molten resin is injected through an injection opening defined in the male mold 20 into the molding space. The molten resin presses the plugs 70 into the corresponding channels 29 against resistance of the corresponding resilient members 79 . The heated gas in the second airproof space is released via the air discharging holes 23 of the male mold 20 when the pressure in the molding space is greater than the predetermined value of the pressure release valve 80 . The molten resin is cooled to form a mold body. The mold is opened, with the male mold 20 being separated from the female mold 30 . The base layer of the foil 100 is released from the mold body. Thus, the printed layer of the foil 100 is attached to a surface of the mold body.
In this embodiment, the injection molding device is used for elongating the foil 100 between the male and female mold 20 , 30 by exhausting air from the cavity 31 via the air discharge holes 32 of the female mold 30 and pressurizing the foil 100 via the heated gas. For example, a length of the first side surface A 1 is a 1 , a length of the second side surface A 2 is a 2 , and a length of the bottom surface A 3 is a 3 , when the first, second, and bottom surface A 1 , A 2 , A 3 of the cavity 31 and the length L accord with an expression a 1 +a 2 +a 3 >=(1+20%)*L, the foil 100 is capable of being elongated for suiting the cavity 31 of the female mold 30 .
Referring also to FIGS. 8 and 9 , in another embodiment, the valve device includes a plug 70 a attached in each channel 29 . The plug 70 a includes a taper-shaped obturating portion 71 a for obturating the recessed portion 291 of the channel 29 , and a pole 73 a extending from a small end of the obturating portion 71 a . A hook 74 a is formed on one end of the pole 73 a away from the obturating portion 71 a . A resilient member 79 a is arranged between the hook 74 a and one end of the channel 29 away from the recessed portion 291 . Two slender ducts 296 a are defined in the male mold 20 each with one end communicating with the end of the channel 29 away from the recessed portion 291 and the other end passing through the surface opposite to the female mold 30 , of the male mold 20 . The end opposite to the female mold 30 , of each slender duct 296 a , is connected to the thermal medium source 90 via a pipe 91 .
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A valve device is configured for obturating an opening of a channel defined in an injection molding device. The valve device includes a plug movably received in the channel, and a resilient member connected with the plug. The plug includes an obturating portion for obturating the opening of the channel. The resilient member is configured for driving the plug to its original position where the obturating portion obturates the opening, after the opening of the channel is opened.
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PRIORITY CLAIM
This is a 35 U.S.C. ยง371 National Stage of International Application No. PCT/EP2003/008674, filed on Aug. 6, 2003. Priority is claimed on that application and on the following application:
Country: Germany, Application No. 102 36 505.9, Filed: Aug. 9, 2002.
BACKGROUND OF THE INVENTION
The invention pertains to an internal combustion engine with a connecting means for connecting a first section to a second section of a wire harness on a cylinder head housing. The invention further relates to a process for installing such a harness.
In an internal combustion engine, the fuel is injected into the combustion chamber through an injector. An electronic controller transmits the appropriate actuating signals, which determine the switching state of the injector. The signals are transmitted over a wire harness. Because the injector is located inside the cylinder head housing, the wire harness must pass through the cylinder head housing. This pass-through is critical, because the cylinder head housing must be sealed to prevent the leakage of lubricant and fuel into the environment. The engine vibrations also subject the wire harness to mechanical stress at the pass-through point.
EP 0 454 895 B1 describes a pass-through for a wire harness on a cylinder head. The wire harness is embedded in a seal, which is mounted between the cylinder head and the boot. In another embodiment, the individual wires of the wire harness are pushed through bores in the seal. The problem here is that the wire harness can suffer mechanical damage as a result of excessive tightening torque when the boot is attached to the cylinder head.
DE 197 34 970 A1 describes a central plug, which is screwed into the cylinder head housing of the internal combustion engine. The wire harness leading from the electronic controller to the injector consists of a first section and a second section. The first section extends from the electronic controller to a โcounterplugโ. The second section of the wire harness extends through the interior of the cylinder head housing from the central plug to the injector. By means of a seal, the central plug seals the cylinder head so that no lubricant or fuel can leak out. The problem with this plug-bushing concept is that the manufacturing of the parts themselves is expensive and the fabrication of the first section of the wire harness with the counterplug is complicated. Another difficulty is that the service life of a plug-bushing concept (3,000 hours of operation) is much shorter than the service life of a large diesel engine (more than 20,000 hours of operation). The plug-bushing concept therefore cannot be used in large diesel engines.
SUMMARY OF THE INVENTION
The invention is based on the task of providing a connecting means for the interface between the wire harness and the cylinder head housing which is low in cost, easy to install, and leakproof.
According to the invention, the connecting means comprises a terminal carrier and a boot and both the terminal carrier and the boot have means by which they lock themselves in position. In the case of the boot, the self-locking means is realized in the form of a latching ring or a latching lobe. In the case of the terminal carrier, the self-locking means is realized in the form of latching lobes. In the installed state, the terminal carrier is fixed in place on the cylinder head housing by the latching lobes, which grip under the cylinder head housing, which has the effect of sealing off the interior space. Then the boot is fixed in place on the terminal carrier by means of the latching ring or latching lobe. No additional work steps are required to attach the boot to the terminal carrier. Nor is there any need for fastening means such as screws or bores. The latching ring in the boot offers the advantage that the boot, to which a corrugated hose is attached, can be rotated to any angle on the terminal carrier. The connecting means is designed to last for the predicted life of a large diesel engine; that is, the connecting means is designed to withstand the effects of vibration for this period of time.
In one embodiment, it is proposed that the terminal carrier be provided with terminals and covers, each terminal consisting of a compression spring and a conductor strip. The second section of the wire harness is permanently connected to the conductor strip by a process such as soldering or crimping. In addition, the second section of the wire harness is embedded in the material of the terminal carrier. This guarantees both leak-tightness and the ability to withstand vibrations. Each of the individual wires of the first section of the wire harness is held in place between the compression spring and the conductor strip by the elastic force of the compression spring. The advantage of this arrangement is that the counterplug at the end of the first section of the wire harness can be eliminated. The only tool required to attach the first section of the wire harness to the terminal carrier is a screwdriver. In addition, the clamping action of the compression spring guarantees a uniform clamping force even under vibrational loads and thus also a uniform transition resistance between the wires of the first section of the wire harness and the conductor strip. In comparison with a conventional screw terminal connection, there is no need to retighten the screw. It is known that, in a screw connection of this type, the copper will creep and the screw will loosen.
Because the inventive connecting device does not need to be screwed in place, sealed, or aligned, the assembly time required is cut in half by comparison with the plug-bushing concept.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred exemplary embodiments are illustrated in the drawings, the same components being designated by the same reference numbers:
FIG. 1 shows an overall diagram;
FIG. 2 shows a connecting means in a first embodiment (detailed drawing of the individual parts);
FIG. 3 shows a connecting means in a first embodiment (drawing of the assembled parts);
FIG. 4 shows a connecting means in a second embodiment (detailed drawing of the individual parts);
FIG. 5 shows a connecting means in a second embodiment (drawing of the assembled parts); and
FIG. 6 shows the sequence of installation steps.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the lower half of a cylinder head housing 2 on a crankcase housing 1 of an internal combustion engine. In the cylinder head housing 2 are an injector 3 and a valve driver 24 . Through a high-pressure line 22 , fuel is supplied under pressure to the injector 3 from, for example, a high-pressure reservoir of a common-rail system. The switching state of the injector 3 is determined by an electronic controller 6 (EDC). The signals are transmitted over a wire harness. This consists of a first section 4 and a second section 5 . The first section 4 of the wire harness extends from the electronic controller 6 to the connecting means 7 . The connecting means 7 represents the interface between the wire harness and the cylinder head housing. The second section 5 of the wire harness extends through the interior of the cylinder head housing 2 from the connecting means 7 to the injector 3 . The end of the second section 5 facing away from the connecting means 7 is connected to the injector 3 by a contact plug 23 . In FIG. 1 , the connecting means 7 is shown before final assembly. Here a terminal carrier 8 has already been permanently attached to the cylinder head housing 2 . The boot 9 is shown on the first section 4 of the wire harness, and the ends of the wires of the first section 4 of the wire harness are shown with their insulation stripped.
Reference is made in the following to FIGS. 2 and 3 . FIG. 2 shows a detailed view of the individual parts of a first embodiment of the connecting means 7 , whereas FIG. 3 shows the parts after they have been assembled. The connecting means 7 consists of the following components: a boot 9 , terminals 16 , a cover 19 , a terminal carrier 8 , and a corrugated hose 21 . The wires of the wire harness are protected by the corrugated hose 21 from the mechanical damage which could be caused by vibrations.
The boot 9 consists of the J-shaped boot parts 9 A and 9 B. These are connected to each other by a plastic hinge. Each boot part carries in the interior a section of a latching ring 11 , reference numbers 11 A and 11 B. This latching ring 11 engages in a groove 12 in the terminal carrier 8 (see FIG. 3 ). Because of this groove-and-ring arrangement, the boot 9 can be rotated 360ยฐ on the terminal carrier 8 . This offers the advantage that the boot 9 , with the corrugated hose 21 attached to it, can assume any desired angle after the connecting means 7 has been attached to the cylinder head. Two terminals 16 are arranged in correspondingly shaped openings in the terminal carrier 8 . Each terminal 16 comprises a compression spring 17 and a conductor strip 18 . The terminals 16 are supported on correspondingly designed contours on the top of the terminal carrier 8 and on the cover 19 . FIG. 2 shows the cover 19 , which has a two-part design, reference numbers 19 A and 19 B. On a base body 25 of the terminal carrier 8 are several webs 26 with latching lobes 15 , formed as integral parts of the carrier. By means of these latching lobes 15 , the terminal carrier can grip the wall of the cylinder head housing 2 after installation. The latching lobes 15 therefore provide the terminal carrier 8 with a self-locking function. To seal off the terminal carrier 8 from the cylinder head housing 2 , a groove 20 is provided to accept an O-ring. The second section 5 of the wire harness is permanently connected to the conductor strip 18 by means of a process such as soldering or crimping. In addition, the second section 5 of the wire harness is embedded in the terminal carrier 8 . This guarantees that the opening will be leak-tight and that the connection will be able to withstand vibrations.
Reference is made jointly in the following to FIGS. 4 and 5 . FIG. 4 shows the individual parts of a second embodiment of the connecting means 7 , and FIG. 5 shows the parts after assembly. The first and second embodiments of the connecting means 7 differ with respect to the design of the boot and by the presence of an additional eye on the terminal carrier 8 ( FIG. 4 ). The connecting means 7 consists of the following components: a boot 10 , a cover 19 , the terminal carrier 8 , and the corrugated hose 21 . Two webs 27 with latching lobes 13 are provided on the boot 10 . By means of these latching lobes 13 , the boot 10 is locked in place after installation in the eyes 14 provided in the terminal carrier 8 . The rest of the functionalities of the terminal carrier 8 , of the lobes 15 , and of the cover 19 are the same as those of the embodiment described on the basis of FIGS. 2 and 3 .
FIG. 6 shows the sequence of steps for installing the connecting means 7 in the cylinder head housing 2 of an internal combustion engine. In step S 1 , the terminal carrier 8 along with the second section 5 of the wire harness is inserted into the cylinder head housing 2 , so that the latching lobes 15 grip the housing wall and lock the terminal carrier 8 in place. In step S 2 , the second section 5 of the wire harness is connected to the injector 3 . In step S 3 , the stripped wires of the first section 4 of the wire harness are connected detachably to the terminal carrier 8 (terminals 16 ). In the last step S 4 , the boot 9 or boot 10 along with the corrugated hose 21 is attached to the terminal carrier 8 .
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The invention relates to an internal combustion engine comprising an injector ( 3 ) which is arranged in the cylinder head. According to the invention, said internal combustion engine is provided with a connecting means ( 7 ) for connecting a first section ( 4 ) of the wire harness to a second section ( 5 ) of the same. Said connecting means ( 7 ) comprises a terminal carrier ( 8 ) and a cover ( 9, 10 ). Both the terminal carrier ( 8 ) and the cover ( 9, 10 ) are provided with self-locking means. In this way, a cost-effective connecting means ( 7 ) is provided, which can be easily and quickly mounted.
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BACKGROUND OF THE INVENTION
The present invention generally relates to systems for translating virtual memory addresses into physical memory addresses, and more particularly to a new and improved content addressable memory (CAM) cell useful in such systems.
A content addressable memory is a memory device in which all memory cells are selected by contents rather than by addresses, which is also known as an associative memory.
It is an object of this invention to provide a high-speed content addressable memory device capable of being loaded in a shift register fashion.
Another related object of this invention is to provide a shiftable content addressable memory device that obviates address decode circuitry.
BRIEF SUMMARY OF THE INVENTION
A new and improved memory cell is provided for storing data supplied on a load data input terminal and this cell is adapted for comparing data supplied on a compare data input terminal with data stored in the cell and for supplying an output signal on a match data output terminal when the compare data is the same as the data stored in the cell. In particular, this memory cell comprises a latch circuit disposed for storing data, which circuit has a true output terminal coupled to the load data input terminal and a not true output terminal. A first means is coupled between the match data output terminal and a reference potential and is disposed for applying the reference potential to the match data output terminal in response to a comparison of the state of the latch circuit and the compare data. A second means is coupled between the match data output terminal and the reference potential and is disposed for applying the reference potential to the match data output terminal in response to a comparison of the state of the latch circuit and the inverse of the compare data.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall block diagram of a system employing the present invention;
FIG. 2 is a detailed block diagram of the address translation buffer;
FIG. 3 is a schematic diagram of the control state machine;
FIG. 4 is a schematic diagram illustrating details of one row of memory cells;
FIG. 5 is a schematic diagram of a typical content addressable memory cell in accordance with the present invention;
FIG. 6 is a schematic diagram of a typical random access memory cell; and,
FIG. 7 is a schematic diagram of a typical row control circuit.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and in particular to FIG. 1, an overall block diagram of a portion of a memory interface device in which the present invention is useful is illustrated. A memory address bus 10 transmitting memory addresses from a processor 11 is coupled to the A input terminals of a multiplexer 12 and to input terminals of an address translation buffer 14. The address translation buffer (ATB) 14 is divided into three basic parts, which will be explained in greater detail hereinafter. A first part is a stack of rows of memory cells forming a content addressable memory (CAM), which is disposed for storing virtual addresses. A second part is a stack (equal in size to the CAM stack) of rows of memory cells forming a random access memory (RAM), which is disposed for storing physical addresses corresponding to the virtual addresses. The third part of the ATB 14 is a stack of an equal number of control circuits disposed for controlling read-in, readout or shifting operations to be explained hereafter. The output terminals of the multiplexer 12 are coupled to a memory fabric 15 by means of a bus 16. It is the function of the memory address translation buffer 14 to translate virtual memory addresses into physical addresses, and the output terminals thereof are coupled to the B input terminals of the multiplexer 12 on a bus 17. The multiplexer 12 selects between either the A or the B input terminals by means of a control signal supplied on a line 18 from the processor 11.
The address translation buffer 14 is controlled by a control state machine 19 which is disposed for transmitting control signals to and from the buffer on lines 20. Control signals from the processor 11 are transmitted to the control state machine 19 on lines 22. Additional input and output signals to and from the address translation buffer 14, which will be more fully understood following the description hereinbelow, are the address translation buffer RAM data (i.e., ATB RAM DATA) supplied on a bus 24 from the processor 11, and the contents of the last row of cells (i.e., LAST ROW) within the buffer 14 supplied on a bus 26 to the processor. In addition, when an address translation comparison operation does not locate a desired address in any of the CAM cells within the buffer 14, a signal entitled ENTRY NOT PRESENT is supplied on a line 28 to the processor 11 and to the control state machine 19. It is noted that in practice, buses 10, 24 and 26 may be a single bus that is time shared by operation in a conventional manner. These buses are illustrated separately for explanation purposes only.
Physical addresses are loaded into the RAM portion of the ATB 14 on the bus 24, while corresponding virtual addresses are loaded into the CAM portion of the ATB by means of the bus 10. During operation, if a virtual address is transmitted on the bus 10, a comparison operation is performed within the CAM portion of the ATB 14 to locate a physical address stored in the RAM portion of the ATB. The physical address, if found, is supplied on the output bus 17 to the B input terminals of the multiplexer 12; and, from there to the memory fabric 15 on the bus 16 when the control signal on the line 18 is active. If no comparison match is found, then the ENTRY NOT PRESENT signal is supplied back to the processor 11 on the line 28.
Referring now to FIG. 2, a block diagram of the address translation buffer 14 is illustrated. The memory address supplied on the bus 10 is applied to the B input terminals of a multiplexer referred to herein as CMUX 30. The output of the CMUX 30 is supplied on a bus 31 to the first row of the p rows of CAM cells (CAM 1) of a memory 32. The output of the last (p) row of CAM cells (CAM p) is coupled to an output bus 26a of the bus 26, and is also coupled back to the A input terminals of the CMUX 30. The CMUX 30 routes the signals on either the A or the B input terminals to the CAM 1 as a function of a SHUFFLE ALL control signal supplied on a line 20d of the lines 20.
In a like manner, the ATB RAM DATA bus 24 is coupled to the A input terminals of a multiplexer referred to herein as RMUX 34. The output of the RMUX is supplied on a bus 38 to the first row of p rows of RAM cells (RAM 1) of a memory 35. Outputs of each of the rows of RAM cells 1 through p are coupled to the bus 17, which is coupled back to the B input terminals of the RMUX 34. The output of the last (p) row of RAM cells (CAM p) is supplied on a bus 26b of the bus 26 for purposes to be described hereinafter. The RMUX 34 routes the signals on either the A or the B input terminals as a function of a LOAD RAM control signal supplied on a line 20e of the lines 20.
The shifting of the contents of the CAM cells of memory 32 row by row down the stack, or the RAM cells of memory 35 row by row down the stack, is controlled by a stack of p control circuits 37. Each of the control circuits 37 is coupled to respective ones of the rows of CAM and RAM cells. The control lines 20 from the control state machine 19 are provided as inputs to the stack of p control circuits 37, which will be explained in greater detail hereinafter. The output of the last, that is the pth control circuit, provides the ENTRY NOT PRESENT signal on the line 28.
In operation, the memory 32 contains p virtual addresses each being stored in a different row thereof. Similarly, the memory 35 contains p physical addresses each being stored in a different row thereof. Referring now to FIG. 3, the control state machine 19 is illustrated in greater detail. In it, an ATB SELECT OPERATION control signal is supplied on a line 22b of the control signal lines 22 to the data D input terminal of a flip-flop 44, which has the Q output thereof coupled to yet another address input terminal of the address portion 40a. Two output lines of the readout portion 40b, which are supplied on lines 46 and 45, are coupled to the data D input terminals of flip-flops 47 and 48, respectively. The Q output terminals of the flip-flops 47 and 48 are coupled to the last two address input terminals of the address portion 40a.
The control signals supplied on the lines 20 are provided at the output terminals of the readout portion 40b of the control matrix 40. These signals are referred to herein as SHUFFLE, SHUFFLE ALL, LOAD RAM, ATB RESULT, and ATB ERROR, and are supplied on lines 20c, 20d, 20e, 22c and 22d, respectively. A final output signal SHUFFLE-TO-INVALID is provided from the Q output terminal of a flip-flop 50 on a line 20f, which has the data D input thereof coupled to an output terminal of the readout portion 40b. The reset (R) input terminals of the flip-flops 42, 44, 47, 48 and 50 are coupled to a line 22e transmitting a RESET signal from the processor 11.
In operation, when the combination of input signals matches those in a single row of the address portion, the numbers in the same row are read out from the readout portion. For example, if the state of the input, reading left to right across the top of the address portion 40a, were to be XX01XXX0, the output would be as follows: a high level signal on the line 20c (SHUFFLE), a high level signal on the line 20e (LOAD RAM), and a high level signal on the line 22c (ATB RESULT). The letter X, as used herein, refers to a don't care situation. Each of the remaining rows operates in a similar manner.
Referring now to FIG. 4, details of row 3 of the ATB structure are illustrated. The memory address supplied on the bus 10 from the processor 11 (FIG. 1) is coupled to the CAM 3 cells 1 through m. The virtual address to be stored in the CAM 3 is supplied on lines 50 to drain terminals of transistors Q1-1 through Q1-m. For the first row of CAM cells, i.e. CAM 1, the lines 50 would be the same as the bus 31 from the CMUX 30. The source terminals of the transistors Q1-1 through Q1-m are coupled to inputs of the CAM cells 1 through m. The gate terminals of these transistors are coupled to a line 51, which transmits a SHIFT signal provided by a control circuit CTL 3. At this juncture of the description, it should be pointed out that the terms source and drain are used herein as a matter of convenience only. In semiconductor practice today, MOS and CMOS transistors are typically fabricated symmetrical. Moreover, in the disclosed embodiment, a high level voltage is +5 volts and a low level voltage is ground potential (zero volts). Furthermore, the reference numerals used for the transistors shown relate to only the illustrated row of memory cells (i.e., row 3), and it being understood that the other rows (not shown) also have transistors configured in the same way as that illustrated in FIG. 4.
The memory address supplied on the bus 10 to the CAM 3 is the address to be compared with the contents of the CAM cells 1 through m of row 3. The contents of the CAM cells 1 through m are loaded by means of the lines 50 in response to a SHIFT signal. In a similar manner, the contents of the CAM cells 1 through m in the CAM 3 are supplied to the next row of CAM cells by means of lines 52-1 through 52-m. When a memory address supplied on the bus 10 matches the contents of one single row of CAM cells such as row 3, a MATCH signal is supplied on a line 54 to the control circuit CTL 3 from the CAM 3.
The contents of the RAM cells in the stack 35 are transmitted from the previous row to row 3 by means of lines 56, which lines are coupled to the drain terminals of transistors Q2-1 through Q2-n. For the first row of RAM cells, i.e. RAM 1, the lines 50 would be the same as the bus 38 from the RMUX 34. The source terminals of the transistors Q2-1 through Q2-n are coupled to the RAM cells 1 through n of the RAM 3. The gate terminals of these transistors are also coupled to the SHIFT line 51. The RAM cells 1 and 2 of the RAM 3 have an additional function to be explained further hereinafter, and accordingly, transistors Q3-1 and Q3-2 are coupled between the inputs to the RAM cells 1 and 2, respectively, and ground potential. The gate terminals of the transistors Q3-1 and Q3-2 are coupled to the RESET signal line 22e. Hence, when the RESET signal is at a high level, the transistors Q3-1 and Q3-2 are turned on thereby grounding the inputs to the RAM cells 1 and 2, which sets a zero in these cells.
The output or contents of the RAM 3 cells are transmitted to the next row by means of lines 60-1 through 60-n. In addition, the line 60-1 is coupled to an input terminal of the control circuit CTL 3 and is also identified as VALID. Similarly, the line 60-2 is also coupled to an input terminal of the control circuit CTL 3 and is also identified herein as UNLOCKED. Hence, the RESET signal going high forces a low-level signal on the lines 60-1 and 60-2, which causes the UNLOCKED and VALID signals to go low. The content readout of the RAM cells in the RAM 3 row is provided at the drain terminals of transistors Q4-1 through Q4-n. The source terminals of the transistors Q4-1 through Q4-n are coupled to the bus 17, which transmits the address output to the MUX 12 (FIG. 1). The gate terminals of the transistors Q4-1 through Q4-n are coupled to a word line 62 from the control circuit CTL 3.
Referring now to FIG. 5, an individual CAM cell such as the cell m will be described. In this cell, a line 50-m of the lines 50, which transmits load data from the previous row CAM cell, is coupled to the drain terminal of a transistor Q1-m and the source terminal thereof is coupled to the gate terminal of the transistor Q10, the input of an inverter 66, and to the output of yet another inverter 68. The gate terminal of the transistor Q1-m is coupled to the SHIFT line 51. Hence, when the SHIFT signal is at a high level the state of the previous row CAM cell is transferred to the cell m at the input of the inverter 66. The inverters 66 and 68 form a latch circuit, wherein the inverter 68 is scaled smaller than the inverter 66 so as to enable the load data from the prior row to override the inverter 68 when changing the state of the CAM cell.
The output of the inverter 66 is coupled to the gate terminal of the transistor Q12 and to the input of the feedback inverter 68. The output of the feedback inverter 68 is coupled back to the input of the inverter 66, thereby forming the latch circuit. Also, the output of the inverter 66 is coupled to the drain terminal of a transistor Q14 having a gate terminal thereof coupled to a ฯ 2 clock input signal. There are two clock signals ฯ 1 and ฯ 2 discussed herein, and each is complementary to the other and they are non-overlapping. These clock signals are generated in a well-known manner not shown herein. The source terminal of the transistor Q14 is coupled to the input of an inverter 70 and to the drain terminal of a p-channel transistor Q16 having the drain terminal thereof coupled to a source of positive voltage (+V). The output of the inverter 70 is the output of the CAM cell m and is coupled to a line 52m of the bus 52. Also, the output of the inverter 70 is coupled to the gate terminal of the p-channel transistor Q16. It is noted that when the transistor Q16 is a p-channel transistor, all other transistors would be n-channel. However, a reverse in polarity of the various transistors described herein could be made without departing from the spirit of the invention.
The output of the inverter 66 is at a high or a low level depending upon the state of the CAM cell m. Assume, for example, that the output of the inverter 66 is at a high level which would turn on the transistor Q12. If the state of the line 10-m is also at a high level (which would mean that for purposes of an individual cell there would be a match), the output of the inverter 64 would be at a low level thereby turning off the transistor Q8. Similarly, the transistor Q6 would be turned on; however, the transistor Q10 would be turned off since the output of the inverter 68 is opposite to the output of the inverter 66 (i.e., a low level). Accordingly, the MATCH signal line 54 remains at a high level since the line 54 is biased at a preselected voltage level in a conventional well-known manner.
If the state of the CAM cell m is to be changed by shifting into this cell or row of cells from the previous cell or row of cells, the SHIFT signal line 51 is raised to a high level and the state of the line 50-m (i.e., the state of the corresponding cell in the previous row) would be transmitted to the input of the inverter 66. Let's assume, for purposes of discussion, that the state of the line 50-m is at a high level. Then, this high-level signal is applied to the input of the inverter 66 when SHIFT is high, thereby dropping the output of this inverter to a low level. This low-level signal is coupled back through the inverter 68 to a high level, which locks the cell m in a one state. Upon the application of a ฯ 2 clock signal to the gate terminal of the transistor Q14, the state of the inverter 70-transistor Q16 buffer circuit will be changed according to the state of the latch circuit (inverters 66 and 68).
FIG. 6 illustrates in greater detail an individual RAM cell such as RAM cell n. In a similar manner, the state of the previous RAM cell is present on the line 56-n of the lines 56 and is coupled through the transistor Q2-n when a SHIFT signal is high on the line 51. This state is applied to the input of an inverter 72 and the output thereof is coupled to the input of yet another feedback inverter 74, to the gate terminal of a transistor Q20 and to the drain terminal of a transistor Q22. The gate terminal of the transistor Q22 is coupled to the ฯ 2 clock signal line. In a similar manner the inverter 74 is scaled smaller than the inverter 72, and these inverters form a latch circuit.
The gate terminal of the transistor Q4-n is coupled to the word line 62 and the drain terminal thereof is coupled to line 17-n of the bus 17 as was illustrated in FIG. 4 and described hereinabove. The source terminal of the transistor Q4-n is coupled to the drain terminal of the transistor Q20 and the source terminal thereof is coupled to ground potential. The transistors Q20 and Q4-n form an open drain NAND gate.
The source terminal of the transistor Q22 is coupled to the input terminal of an inverter 76 and the output thereof is coupled to the gate terminal of a p-channel transistor Q24 having the drain terminal thereof coupled to a voltage source (+V). The source terminal of Q24 is coupled back to the input terminal of the inverter 76. The output of the inverter 76 is also coupled to the line 60-n, which line is coupled to the next row of RAM cells as was illustrated in FIG. 4 and described hereinabove. The inverter 76 and the transistor Q24 form a buffer circuit.
In operation, when a high level signal is supplied on the word line 62, the transistor Q4-n is turned on and if the transistor Q20 is on, the line 17-n is pulled down to ground potential. The transistor Q20 would be turned on in response to a high-level signal at the output of the inverter 72, which indicates that the RAM cell is in a one state. On the other hand, if the output of the inverter 72 is at a low level (RAM cell in a zero state), the transistor Q20 is turned off and the line 17-n remains at its biased level. Each of the lines 17 are biased at a preselected voltage level in a conventional well-known manner.
Referring now to FIG. 7, details of the control circuit such as CTL 3 are illustrated in greater detail. The MATCH signal line 54 is coupled to the drain terminal of a transistor Q30 and the source terminal thereof is coupled to the A input terminal of a multiplexer 80, to the gate terminal of another transistor Q32 and to the word line 62. The gate terminal of the transistor Q30 is coupled to the ฯ 2 clock signal. The drain terminal of the transistor Q32 is coupled to the ENTRY NOT PRESENT signal line 28 and the source terminal thereof is coupled to ground potential. The VALID signal line 60-1 is coupled to the input terminal of an inverter 82 and the output of the inverter 82 is coupled to the B input terminal of the multiplexer 80 and to the gate terminal of a transistor Q34. The drain terminal of the transistor Q34 is coupled to the ALL VALID signal line 22a and the source terminal thereof is coupled to ground potential. The ENTRY NOT PRESENT, ALL LOCKED and the ALL VALID signal lines are biased at a preselected voltage level in a conventional well-known manner. The SHUFFLE-TO-INVALID signal line 20f is coupled to the SELECT input terminal of the multiplexer 80 and the output terminal of the multiplexer 80 is coupled to an inverting input terminal of an AND gate 84. When the SHUFFLE-TO-INVALID signal is at a high level, the B input terminal is selected and when at a low level, the A input terminal of the multiplexer 80 is selected.
A CHAIN signal, which is used in a shuffle-to-match and shuffle-to-invalid operations to be described further hereafter, is supplied on a line 86 to a first of two input terminals of an OR gate 88 and to the second input terminal of the AND gate 84. The output of the AND gate 84 couples the CHAIN signal to the next row control circuit. The SHUFFLE-ALL signal supplied on the line 20b is coupled to the second input terminal of the OR gate 88, and the output terminal of the OR gate 88 is coupled to one of two input terminals of an AND gate 90. The SHUFFLE signal supplied on the line 20c and the ฯ 1 clock signal are applied to the two input terminals of an AND gate 92 and the output terminal of this AND gate is coupled to the second input terminal of the AND gate 90, which output terminal is also disposed for connection in the subsequent row control circuit. Refer to FIG. 3, and the right-most column of the readout portion 40a of the control matrix 40 for signal combinations producing a high-level state of the SHUFFLE signal. The output terminal of the AND gate 90 is coupled to the line 51 transmitting the SHIFT signal as described hereinabove. Note that the ฯ.sub. 1 clock signal forms part of the SHIFT signal, while the actual transfer of data from the prior row is controlled by the ฯ 2 clock signal (FIG. Q14 and FIG. 6 Q22). This arrangement assures stability of operation.
The UNLOCKED signal supplied on the line 60-2 is coupled to the gate terminal of a transistor Q36 having the drain terminal thereof coupled to the ALL LOCKED signal line 22b and the source terminal thereof coupled to ground potential.
When a MATCH signal is supplied on the line 54 and when the ฯ 2 clock signal is at a high level, the word line 62 is raised to a high level which turns on the transistor Q32. The transistor Q32 turning on grounds the ENTRY NOT PRESENT signal line 28 which indicates that an entry is present in the ATB 14.
At this juncture of the description, reference is made to FIGS. 2, 3 and 7 for aid in explaining the various shuffle operations. Assume that during the search of the memory 32, a matching virtual address is located in the CAM 3 row of cells. By means of the MATCH signal supplied on the line 54 to the control circuit CTL 3 the contents of the RAM 3 row of cells is read out on the bus 17 and simultaneously loaded into the RAM 1 row of cells. It is therefore necessary to perform a shuffle-to-match operation. The information that was in the first row of cells is loaded into the second row of cells while the information that was in the second row of cells is loaded into the third row of cells.
In order to perform the shuffle-to-match operation, it is necessary to enable the AND gate 90 by enabling the OR gate 88 and the AND gate 92. In the first row control circuit CTL 1, the CHAIN signal line is tied to a high level voltage. Continuing with the example above, a MATCH signal on the line 54 produces a high-level signal on the WORD LINE 62 when the ฯ 2 clock signal is high, which also appears at the A input terminal of the multiplexer 80. The ENTRY NOT PRESENT signal line is pulled down to ground potential by the transistor Q32. The SHUFFLE-TO-INVALID signal line 20f is at a low level for all operations except where performing a LOAD ATB operation in which there is no match and in which an INVALID entry is present in the ATB. Accordingly, the high-level signal at the A input terminal of the multiplexer 80 is provided at the output terminal thereof and causes the AND gate 84 to be disabled. Hence, the CHAIN signal is not passed on to the fourth row of CAM and RAM cells, but was coupled between the first three rows for enabling the AND gate 90 thereby providing the SHIFT signal.
With brief reference to FIG. 4, the RAM CELLs 1 and 2 are reset to zero in response to a RESET signal on the line 22e. When a row of CAM and RAM cells are loaded with a virtual and physical address, respectively, the RAM CELL 1 is set to a one thereby indicating a valid address is stored in that row. If, on the other hand, nothing has been loaded into a row of CAM and RAM cells, or data that has been loaded into a row of memory cells that has been explicitly denoted as invalid, the RAM CELL 1 will be set to zero, then the VALID line 60-1 will be at a low level.
Under the above state of the signals, the output of the inverter 82 (FIG. 7) would be at a high level and if the SHUFFLE-TO-INVALID signal on the line 20f is at a high level, then the output of the inverter 82 is passed through the multiplexer 80 to disable the AND gate 84. For the next row of cells, the CHAIN signal is blocked. Hence, a shuffle operation is performed through the row having the invalid address.
As described hereinabove, the least recently used address gravitates to the last row by virtue of each accessed address being relocated to the first row, while shuffling all other stored addresses down one row. If it is necessary to store another virtual-physical address pair, and there is no more space in the ATB, a decision is to be made by the processor 11 as to whether or not to erase the least recently used address in the last row of cells. To assist in this operation, a virtual-physical address pair may be assigned a locked status bit which would prevent erasure. This status bit is stored in the RAM CELL 2 and the signal on this CELL's output line 60-2 is referred to herein as UNLOCKED.
If the address pair stored in the last (pth) row of cells is either an INVALID or a LOCKED address, then it is automatically cycled (during an idle time period) up to the first row and all rows are shuffled down one row by use of the SHUFFLE ALL signal.
The foregoing description of a system and logical circuit implementation are intended to be explanatory of a content addressable memory cell with reference to use in an address translation buffer. It will be understood from the foregoing that various changes may be made in the preferred embodiment illustrated herein, and it is intended that the foregoing materials be taken as illustrative only and not in a limiting sense. It is therefore intended that the scope of the invention is defined by the following claims.
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A new and improved content addressable memory cell is disclosed, which cell stores data supplied on a load data input terminal thereof. The disclosed memory cell is adapted for comparing data supplied on a compare data input terminal thereof with data stored in the cell, and for supplying an output signal on a match data output terminal when the compare data is the same as the data stored in the cell. A latch circuit is employed as the storage element of the cell. First and second means are each coupled between a reference potential and the match data output terminal, which means are operative in response to the state of the latch circuit and the compare data supplied on the compare data input terminal.
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FIELD OF THE INVENTION
[0001] This invention relates to screening machines of the type used to separate or classify mixtures of solid particles of different sizes. The invention also relates to screening machines of the type used for liquid/solid separations, i.e., for separating solid particles of specific sizes from a liquid in which they are carried. More particularly, the invention relates to a mechanism and method for sealing components within the screening machine.
BACKGROUND OF THE INVENTION
[0002] In screening machines of the type described, a screen (which may be woven, an aperture plate or another design) is mounted in what is often called a โscreen frameโ or โscreen deckโ which includes a supporting peripheral frame around the perimeter of the screen. Typically associated with this screen frame are other material handling elements which are moved with the screen frame and form walls or partitions above or below the screen frame for containing the liquid and/or particulate materials adjacent to the screen and directing them to appropriate outlets. These elements may include a top cover and a pan beneath the screen frame. In the case of screening machines with multiple screens or deck units, spacer pans or frames are provided between the multiple screens.
[0003] The screen frames are often removed from the screening machines for cleaning, replacement, readjustment or installation of a screen of a different mesh size or the like. The screen frame is releasably mounted to a carrier, frame, table or box to which vibratory motion is imparted, typically by one or more eccentric motors or other means of excitation. The carrier, frame, table or box is referred to herein as a โvibratory carrierโ. The vibratory carrier may be moved in oscillatory, vibratory, gyratory, gyratory reciprocating, fully gyratory, rotary or another type of motion or combinations thereof, all of which are herein collectively referred to as โvibratoryโ motion or variations of that term.
[0004] In large commercial screening machines, the weight of the various components including the screen assembly carried by the vibratory carrier, and the weight of the material being processed on the screen assembly may total several hundred pounds or more. This presents a very substantial inertial mass which resists the changes of motion applied thereto by the vibratory drive acting through the vibratory carrier. As a result of these inertial forces, a relative motion may exist between the vibratory carrier and the screen frame. Known screen frames and vibratory carriers are each constructed of metal which could result in significant noise, wear or damage due to the relative motion or rubbing action therebetween. The resulting impact forces between the screen frame and vibratory carrier significantly increase the stresses on the components and reduce their useful life.
[0005] Reducing the metal-to-metal contact minimizes the wear on the various metal components and the noise associated with the operation of the screening machine. In some screening machines, a seal is provided between the screen frame and adjacent components such as other screen frames or the vibratory carrier. The seal prevents the escape of material from the screen frame and reduces the detrimental metal-to-metal contact between the screen frame and adjacent components. Certain screen frame designs may not be sealed or secured relative to the remainder of the screening machine, particularly in larger screening machines. This results in the above-described metal-to-metal contact between the screen frame and the remainder of the screening machine and prevents the screening of very fine material, such as sand or the like. The screen frames in known larger screening machines may be inserted and/or removed from the machine in a generally horizontal direction through an opening or slot at, for example, the head or foot end of the machine. This method of installation and removal of the screen frame is detrimental to known sealing arrangements because a seal which would engage the screen frame could be torn or damaged during the installation/removal and/or reinsertion of the screen frame. In other known screening machines, the screen frame may be inserted vertically, typically from the top of the machine.
[0006] One known sealing mechanism for screening machines is disclosed in U.S. Pat. No. 5,226,546 which relates to a pneumatic seal that is inflated to raise up the screen frame for engagement with a seal. However, pneumatic systems by their very nature utilize a working fluid which may leak, thereby lowering the seal pressure. Furthermore, pneumatic systems require an air source at the machine location and traditionally are only used with the insertion/removal of the screen frame through the top of the machine in a generally vertical direction. Furthermore, screening machines with multiple screens and screen frames may require many or all of the screen frames to be removed for access to an individual screen frame. Furthermore, inspection of the resulting seal in pneumatic systems is not readily available.
[0007] Known alternatives to pneumatic sealing systems for screening machines include mechanical clamps or locks located at a number of spaced locations on the sides of the machine. One example of this type of known mechanism is disclosed in U.S. Pat. No. 5,392,925. However, to clamp each of the screens in place, the user must progressively move along a first side of the machine tightening and adjusting each of the individual mechanism and then proceed to the opposite side of the machine and repeat the same procedure. This mode of operation is inefficient, time consuming and inconvenient for the user. Additionally, the user cannot easily inspect the resulting seal when going from clamp site to clamp site in such systems. Furthermore, the screen frames utilized in screening machines with known mechanical sealing mechanisms must be robust and heavy because they are supported at individual spaced locations by the clamps.
[0008] U.S. Pat. No. 6,070,736 discloses a sealing mechanism including ramps having linear cam surfaces to bring a vibratory carrier respectively into and out of sealing engagement. A problem with the sealing mechanisms of this type may include the opportunity for a technician or user of the machine to advance the cam surface out of position thereby jamming the carrier into the machine.
[0009] Therefore, it is apparent that there is a need for a sealing mechanism and method for screening machines which avoids metal-to-metal contact between the screen frame and adjacent components of the screening machine without the disadvantages associated with known pneumatic or mechanical sealing systems of the prior art.
SUMMARY OF THE INVENTION
[0010] In accordance with an embodiment of the invention, a screening machine includes a vibratory carrier and a vibratory drive operatively coupled to the carrier for imparting vibratory motion thereto. The screening machine includes a screen assembly having at least one screen mounted to a peripheral screen frame, which is selectively coupled to the carrier so that the vibratory motion is transmitted to the screen assembly. A sealing mechanism including at least one rotary cam having a cam surface and at least one actuator being accessible to a user of the screening machine is coupled to the rotary cam.
[0011] Actuation of the actuator to rotate the cam urges the screen assembly and the carrier into sealing engagement with a confronting surface of the screening machine. The screening machine further includes at least one stop positioned relative to the sealing mechanism to limit rotational movement of the cam in at least one direction.
[0012] The screening machine may include two rotary cams coupled to the actuator. Two stops may be positioned relative to the sealing mechanism to limit rotational movement of the cam in a clockwise direction and a counter-clockwise direction. The two stops may define a limiting cam which is coaxial with the rotary cam.
[0013] At least one rotary cam may lie proximate a first edge on the peripheral screen frame and the screening machine may include a second rotary cam disposed proximate a second edge on the peripheral screen frame, which is disposed opposite the first edge.
[0014] A screening machine in one embodiment includes at least one stop preventing rotation of the rotary cam beyond about 110ยฐ from a lowest vertical position of the screen assembly and the carrier. The stop prevents rotary motion of the rotary cam in one direction beyond a lowest vertical position of the screen assembly and the carrier. In another aspect of one embodiment, a cam has a surface portion adapted to permit rotary motion of the rotary cam beyond a highest vertical position of the screen assembly and the vibratory carrier.
[0015] A screening machine according to this invention may include a rotary cam having a cam surface configured such that a tool driving the actuator is in a generally horizontal orientation when the screen assembly and the carrier reach a highest vertical position. The screening machine may further include a bracket, such that the at least one stop is integrally formed with the bracket.
[0016] In another embodiment, a method of sealing a screen frame having a screen within a screening machine includes inserting the screen frame and screen within a vibratory carrier of the screening machine. The vibratory carrier imparts vibratory motion to the screen frame and the screen during use of the screening machine which includes a sealing member being positioned on a portion of the vibratory carrier.
[0017] In another aspect of this embodiment, the method includes actuating a sealing mechanism having portions extending along a length of at least one side of the screen frame from an end of the screen frame. Such actuation is effected by rotating a rotary cam to urge the vibratory carrier and screen frame into and out of sealing engagement with corresponding portions of the screening machine. The method also includes rotating the rotary cam until a first stop is reached positioned to restrict rotational movement of the rotary cam in at least one direction.
[0018] The invention may also include rotating the rotary cam to urge the vibratory carrier and screen frame out of sealing engagement with corresponding portions of the screening machine to engage a second stop positioned to restrict movement of the rotary cam in a direction beyond a lowest height of the vibratory carrier and screen frame.
[0019] Advantageously, by including at least one rotary cam having at least one stop to prevent rotational motion thereof, the screening machine described herein has a sealing mechanism that effectively seals the screen frame without damaging it or adjacent components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] These and other objectives and advantages will become readily apparent to those of ordinary skill in the art from the following description of embodiments of the invention and from the drawings in which:
[0021] FIG. 1 is a perspective view of an exemplary screening machine;
[0022] FIG. 2 is an enlarged elevation view of one embodiment of a sealing mechanism of the screening machine of FIG. 1 ;
[0023] FIG. 3 is a view similar to that of FIG. 2 showing a point in the rotation of a cam of the sealing mechanism of FIG. 2 ;
[0024] FIG. 4 is a view similar to those of FIGS. 2-3 showing a subsequent point in the rotation of the cam of FIG. 3 ;
[0025] FIG. 5 is a perspective view of a rotational cam assembly and actuator according to one embodiment of the sealing mechanism of FIGS. 2-4 ;
[0026] FIG. 6 is an elevation view of an exemplary embodiment of a primary cam of the sealing mechanism of FIGS. 2-5 ;
[0027] FIG. 7 is an elevational view of another exemplary embodiment of a primary cam of the sealing mechanism of FIGS. 2-5 ; and
[0028] FIG. 8 is a perspective view of a bracket according to one embodiment of the sealing mechanism of FIGS. 2-5 .
DETAILED DESCRIPTION
[0029] With reference to FIG. 1 , an exemplary embodiment of a screening machine 10 in which this invention may be used is shown. Screening machines of many types are sold commercially by Rotex, Inc. of Cincinnati, Ohio, the assignee of this invention. However, this invention is not limited to any particular type of screening machine design or component and the machine and associated components depicted and disclosed herein are shown for illustrative purposes.
[0030] The screening machine 10 includes an inlet port 12 near an inlet section 14 proximate a head end 16 of the machine 10 . The screening machine 10 may also include a top cover 18 in any one of a variety of forms. Particulate or other material to be screened is fed into the inlet port 12 from a hopper (not shown) for screening and processing by the machine 10 .
[0031] The screening machine 10 is supported structurally by a base frame 20 including beams 22 connected together by laterally oriented struts 24 on each end of the screening machine 10 . The screening machine 10 includes an electric motor 26 coupled to a drive weight (not shown) to impart an oscillatory, vibratory, gyratory, gyratory reciprocating, fully gyratory, other motion or combinations thereof (herein collectively referred to as โvibratoryโ motion or variations of that term) to at least the head end 16 .
[0032] Within a screening chamber of the screening machine 10 , one or more screen assemblies 28 are each mounted in combination to form one or more screen decks 30 to receive the material being screened from the inlet port 12 at the head end 16 of the machine 10 . The screen assemblies respectively include screen panels 28 , which are mounted on slightly sloping planes (about 4ยฐ) with the head end thereof being slightly elevated relative to a foot end so that during the screening process the material advances, in part by gravity, over the screen panels 28 toward the foot or discharge end 32 of the machine 10 . Even though the screen panels 28 of the screening machine 10 may be on a slightly sloping plane, to provide a reference for the purposes of clarity herein, these components will be considered to be generally horizontal and the direction perpendicular or orthogonal to the screen panels 28 will generally be referred to as a vertical orientation, direction or attitude. The direction of travel of the material being screened from the head end to the foot end across the screen panels 28 is referred to as the longitudinal direction and the perpendicular orientation extending from side to side on the screen panels is a lateral direction.
[0033] In the embodiment of the screening machine 10 shown in FIG. 1 , upper and lower screen decks 30 a,b each include four screen panels 28 mounted generally coplanar with each other in the associated screen deck 30 a,b . Accordingly, as the material to be screened is deposited from the inlet port 12 onto the upper screen deck 30 a , the vibratory motion of the screening machine 10 advances the material longitudinally across the top of the screen panels 28 of the upper screen deck 30 a toward the foot end 32 . Appropriately sized and configured material passes through the upper screen deck 30 a and falls onto the lower screen deck 30 b . The screen panels 28 of the upper screen deck 30 a may include a fine mesh screen material 34 adjacent the inlet port 12 through which dust and other fine particulate matter passes for collection and discharge. Certain material also passes through the upper screen deck 30 a and is deposited on the lower screen deck 30 b . Therefore, the lower screen deck 30 b is included to provide an additional separating mechanism for the appropriately sized particles to pass through the second lower screen deck 30 b for collection in the lower pan (not shown) and discharge through an outlet or exit section 36 .
[0034] The unacceptably sized particles remain atop the first upper screen deck 30 a and fall off the terminal edge thereof into a collection basin (not shown) for discharge through the outlet section 36 . Material that passes through the upper screen deck 30 a and remains atop the lower screen deck 30 b falls off the terminal edge thereof and into the collection basin for discharge through a reject port (not shown). The discharge and reject ports are separated by a baffle (not shown) to keep the classified particles separate from one another.
[0035] With continued reference to FIG. 1 , one or more doors 38 are each pivotally connected by a hinge 40 to a lateral side 42 of the screening machine 10 . When opened, the doors 38 provide access for insertion and removal in the lateral direction of the screen panels 28 . It will be appreciated that although one side 42 of the screening machine 10 is shown in FIG. 1 , additional doors on the opposite side of the screening machine 10 may also be provided. The screen panels 28 may be inserted laterally or perpendicularly to the longitudinal direction of travel of the material being screened in the screening machine 10 from the head end 16 to the foot end 32 of the machine 10 .
[0036] With reference to FIGS. 1-2 , when the screen panel 28 is inserted into the screening machine 10 , it is supported on a vibratory carrier 44 . In one embodiment, the vibratory carrier 44 may include a ball tray 46 capturing a number of balls or other agitation producing members (not shown) which repeatedly impact the screen panel 28 to dislodge particulate material that might accumulate on the screen material 34 and inhibit occlusion of the screen material 34 as is well known in the art.
[0037] One embodiment of the screen panel 28 includes a generally perforated mesh screen material 34 including a number of intersecting longitudinal and lateral threads, wires or strings which are oriented orthogonally to each other to provide appropriately sized and configured openings in the mesh screen material 34 to prevent/permit the passage particulate material therethrough. The screen panel 28 includes a generally rigid perimeter frame 54 having a leading side edge 56 opposite from a trailing side edge 58 .
[0038] With continued reference to FIGS. 1-2 , the leading side edge 56 of the screen panel frame 54 may be inserted laterally into the screening machine 10 while a user or operator grasps the trailing side edge 58 for manipulation. In particular, a downwardly turned elongate handle 60 is formed on the trailing side edge 58 of the screen panel 28 . In one embodiment, the handle 60 is oriented about 90ยฐ relative to the plane of the screen panel 28 and provides a convenient and easy access for the user or technician to grasp or manipulate the screen panel 28 . Additionally, the handle 60 or adjacent surfaces of the screen panel frame 54 provide a convenient location for identifying indicia and labels indicating various service parameters, design characteristics and other aspects of the screen panel 28 .
[0039] One or more tabs 62 each located proximate a head end 64 or a tail end 66 of the screen frame 54 are located along the trailing side edge 58 of the frame. The tabs 62 are each oriented about 90ยฐ relative to the plane of the screen panel 28 and along with the handle 60 provide a convenient location for the user or technician to grasp and manipulate the screen panel frame. Likewise, upon insertion of the screen panel 28 into the screening machine 10 , the tabs 62 and handle 60 provide a detent when juxtaposed against the vibratory carrier 44 for proper orientation and location of the screen panel 28 in the screening machine 10 .
[0040] With continued reference to FIGS. 1-2 , in another aspect of the illustrated embodiment of the screen panel 28 and associated frame 54 , beveled edges or lips 68 extend along the longitudinal head end 64 and/or foot end 66 of the screen panel frame 54 . Each lip 68 is oriented about 45ยฐ relative to the upper surface or plane of the screen panel 28 and extends substantially along the entire width of the frame 54 . While the lips 68 are shown along both the longitudinal head and foot ends 64 , 66 of the screen panel frame 54 , one of ordinary skill in the art will readily appreciate that the lip 68 may be provided at neither, either or both of the head and foot ends 64 , 66 .
[0041] With reference to FIGS. 2-4 , the screening machine 10 includes a sealing mechanism which will now be described. One example of a sealing mechanism is disclosed in U.S. patent application Ser. No. 11/382,353, filed May 6, 2006, and hereby incorporated by reference. The downwardly turned bevel lips 68 along the head and foot ends 64 , 66 of the screen panel frames 54 are supported by a similarly inclined face 70 of the vibratory carrier 44 as shown in FIG. 2 . A compressible seal member 72 lies juxtaposed to the terminal edge 74 of the lip 68 and is mounted in the carrier 44 . Likewise, a lower surface of the screen panel frame 54 is supported along a similarly configured profile of the carrier 44 as shown in FIG. 2 .
[0042] The sealing mechanism also includes a bracket 76 that cooperates with a rotational cam assembly 78 sitting thereon and which supports the carrier 44 . The rotation of the cam assembly 78 is accomplished by an actuator 80 accessible to the operator or technician when the door 38 of the screening machine 10 is open. The screening machine 10 also includes a downwardly depending channel 82 initially spaced from the bevel lip 68 of the screen frame 54 as shown in FIG. 2 .
[0043] With continued reference to FIGS. 2-4 , upon rotation in the direction of arrow A (i.e., clockwise) of the actuator 80 , the cam assembly 78 is rotated, thereby raising the carrier 44 and screen panel 28 supported thereon upwardly into sealing engagement with an upper portion 84 of the screen deck 30 a , b as shown in FIG. 3 . As the carrier 44 supporting the screen panel 28 is raised, a face 86 of the channel 82 is juxtaposed against the bevel lip 68 of the screen panel frame 54 and the seal member 72 is compressed against the channel 82 . As a result, the upper portion 84 of the screen deck 30 a, b and upper surface of the screen panel frame 54 are sealed to prevent and inhibit the discharge of material being screened. In another aspect of this embodiment, the orientation of the seal member 72 is generally parallel with the lateral direction in which the screen panel 28 is inserted and removed respectively into and from the machine 10 .
[0044] While the exemplary embodiment of FIGS. 2-4 is depicted having a vibratory carrier 44 and screen panel frame 54 capable of sealing engagement with an upper portion of a deck 30 a, b , persons of ordinary skill in the art will readily appreciate that, alternatively, the vibratory carrier 44 and screen panel frame 54 or any other part of the screen assembly may be capable of sealing engagement with any other suitably chosen part of the screening machine 10 , such as, for example, a fixed support frame.
[0045] With reference to FIG. 5 , the actuator 80 in this exemplary embodiment includes a conventional bolt 79 having a hex head 81 and a threaded body section 83 . The actuator 80 further includes a locking nut 85 threadably engaged with the threaded body section 83 and a conventional serrated washer 87 that receives the threaded body section therethrough. The threaded section 83 is threadably engaged within a correspondingly threaded aperture 89 in the rotational cam assembly 78 such that the washer 87 lies between the locking nut 85 and the threaded aperture 89 . The actuator 80 cooperates with the cam assembly 78 and bracket 76 , as described below.
[0046] The rotational cam assembly 78 includes a limiting cam go and a primary cam 92 , both disposed generally proximate the trailing side edge 58 and both rotational about an axis 94 , as well as a shaft 95 supporting both cams go, 92 and extending in the direction of the head and foot ends 64 , 66 of the screen panel frame 54 . The rotational cam assembly 78 may further include a secondary cam 96 supported by the shaft 95 , disposed generally proximate the leading side edge 56 of the screen panel frame 54 , and generally similar in profile to the primary cam 92 . A protrusion 93 may be also present extending from the secondary cam 96 and engageable with a slot (not shown) in the screening machine 10 to facilitate rotation of the secondary cam 96 about the axis 94 . As such, the leading and trailing side edges 56 , 58 of the screen panel frame 54 may be lifted in unison as the actuator 80 is rotated, thereby maintaining the screen panel 28 generally horizontal during raising and lowering thereof.
[0047] In another aspect of this embodiment, the locking nut 85 permits locking of the angular position of the primary cam 92 and thereby the corresponding positions of the carrier 44 and screen panel 28 with respect to the screening machine 10 . Persons of ordinary skill in the art will readily appreciate that, alternatively, the sealing mechanism may include any other type of fastener or structure capable of providing the locking functionality of locking nut 85 , or even include no locking fastener or device at all.
[0048] With continued reference to FIG. 5 , the primary cam 92 includes a profile defined by serially disposed arcuate and flat surfaces 98 such that rotation of the actuator 80 in a specified direction results in raising and lowering of the screen panel 28 and subsequent sealing thereof and of the carrier 44 against the surface 84 of the screen deck 30 a, b , as described above.
[0049] In one embodiment, the surfaces 98 may be configured as shown in FIG. 2 , wherein clockwise rotation of the actuator 80 results in raising of the carrier 44 and screen panel 28 , while counter-clockwise rotation lowers these two components. Persons of ordinary skill in the art will appreciate the fact that the surfaces 98 may be configured such that, alternatively, clockwise rotation lowers the carrier 44 and screen panel 28 while a counter-clockwise rotation raises them. The surfaces 98 may be further configured such that different rising rates (i.e., increase in height of the carrier 44 and screen panel 28 ) are achieved corresponding to a given angular rotation of the primary cam 92 . For example, and without limitation, the surfaces 98 may be configured to yield a higher rising rate in rotations between about 0ยฐ and about 60ยฐ from a the lowest position of the carrier 44 and screen panel 28 than the rising rate during the subsequent about 30ยฐ.
[0050] In another exemplary embodiment, the configuration of the surfaces 98 of the primary cam 92 may be designed such that the carrier 44 and screen panel 28 reach their maximum height when a wrench or the like tool driving the actuator 80 is in a generally horizontal position, thereby facilitating the application of torque by the operator to seal the carrier 44 and screen panel 28 against the surface 84 on the upper screen deck 30 a, b or any other suitably chosen portion of the machine 10 , as explained above. Moreover, the surfaces 98 may be configured such that the seal 72 and associated components are neither damaged nor compromised with any rotational motion of the primary cam 92 , thereby extending the service life of the seal 72 while maintaining effective sealing and associated screening operations.
[0051] While the above exemplary configurations of the surfaces 98 describe them as contemplated configurations for the primary cam 92 , persons of ordinary skill in the art will readily appreciate that the same are also applicable to the secondary cam 96 , if present.
[0052] With reference to FIGS. 2-5 , the cam assembly 78 includes a limiting cam go coaxial with the primary cam 92 . The limiting cam go includes serially disposed surfaces 100 which may or may not be configured to match corresponding surfaces 98 on the primary cam 92 . In one embodiment, the surfaces 100 may be configured such that the limiting cam go simply โfloatsโ over (i.e., does not make contact with) the surfaces against which the primary cam 92 moves. The limiting cam go includes one or more limiting surfaces 102 , 104 such that rotation in at least one direction (i.e. clockwise or counter-clockwise) is limited when one of such surfaces 102 , 104 engages a stop block, to be described below. In the illustrative embodiment of FIGS. 2-5 , the limiting cam go includes two limiting surfaces 102 , 104 such that rotation of the primary cam 92 is limited in both, clockwise and counter-clockwise directions.
[0053] The clockwise limiting surface 102 is circumferentially disposed on the limiting cam go such that clockwise rotation is prevented beyond a point that may lead to damage to the primary and secondary cams 92 , 96 , screen panel frame 54 , carrier 44 , seal 72 or other components of the screening machine 10 . In one exemplary embodiment, the clockwise limiting surface 102 may be configured such that it maximizes rotation of the cam at about 110ยฐ from the lowest position of the carrier 44 and screen panel 28 .
[0054] Similarly, the counter-clockwise limiting surface 104 is circumferentially disposed on the limiting cam go such that counter-clockwise rotation is prevented beyond a desired position. In one exemplary embodiment, the counter-clockwise limiting surface 104 may be configured such that the primary cam 92 cannot rotate counter-clockwise from the lowest position of the carrier 44 and screen panel 28 .
[0055] With reference to FIGS. 6-7 , two illustrative embodiments of the primary cams 92 a , 92 b are depicted. These cams respectively include a notch 93 a , 93 b that receives the shaft 95 as well as an outer surface profile 99 a , 99 b . The configuration and design of each of the outer surface profiles 99 a , 99 b are suitably chosen to carry out functions such as those described above to determine, for example, the extent of any rotational motion of the primary cam 92 a , 92 b beyond a maximum height reached by the carrier 44 and screen panel 28 .
[0056] With reference to FIG. 6 , the outer surface profile 99 a of the exemplary primary cam 92 a includes respective top and bottom surface portions 101 a , 102 a . The top and bottom portions 101 a , 102 a are relative flattened such that relative motion of the carrier 44 and screen frame 28 with respect to the screening machine 10 levels out. More particularly, rotational motion of the primary cam 92 a beyond a final position such as one corresponding to a maximum or minimum height of the carrier 44 and screen panel 28 yields little or no substantial change in position. Such configuration signals an operator that a maximum or minimum height of the carrier 44 and screen panel 28 has been reached.
[0057] With reference to FIG. 7 , the outer surface profile 99 b of the exemplary primary cam 92 b includes respective top and bottom surface portions 101 b , 102 b . The top and bottom portions 101 b , 102 b are relative peaked such that an operator is made aware of the fact that a maximum or minimum height of the carrier 44 and screen panel 28 has been reached and passed. In another advantageous aspect of this embodiment, the peaks 103 of the top and bottom portions 101 b , 102 b provide locks that may make the locking nut 85 redundant. More particularly, once rotation of the primary cam 92 b in a first direction is such that a peak 103 has been reached and passed, inadvertent rotation in a second, opposite direction is not likely to occur. This is because a relatively large torque is required to rotate the primary cam 92 in the second direction past a corresponding peak 103 .
[0058] With reference to FIG. 8 , and as mentioned above, the sealing mechanism includes a bracket 76 mounted on a screen deck 30 a, b , and includes a wall 104 defining a notch 106 . The wall 104 and notch 106 are disposed to support the cam assembly 78 and allow access to the actuator 80 . In the illustrative embodiment of FIG. 8 , the wall 104 and notch 106 are disposed such that a portion of the threaded body section 83 of the bolt 79 is received therein, for example, between the locking nut 85 and the serrated washer 87 .
[0059] The bracket 76 includes a bottom plate 108 adapted to receive motion of the primary cam 92 along the surfaces 98 in ways well known to those of ordinary skill in the art. A stop block 110 is mounted on the bottom plate and provides a surface engageable against the limiting surfaces 102 , 104 to prevent further rotational motion of the primary cam 92 , as explained above. The dimensions and shape of the stop block 110 are such that suitable engagement is made possible against either or both of the limiting surfaces 102 , 104 while permitting rotational movement of the primary cam 92 . To that end, the stop block 110 may be integrally formed with or coupled to the wall 104 and/or the bottom plate 108 such that no extraneous surfaces such as welding points extend beyond the volume occupied by the stop block 110 and interfere with the motion of the primary cam 92 .
[0060] With continued reference to FIG. 8 , the stop block 110 , wall 104 , and bottom plate 108 are made of materials suitable to support the cam assembly 78 while resisting a force applied against it when any of the limiting surfaces 102 , 104 engage the stop block 110 . For example, and without limitation, the stop block 110 , wall 104 and bottom plate 108 may be made of metal such as steel and further be integrally formed from one of several known casting processes known to those of ordinary skill in the art.
[0061] While the above description describes an embodiment including one bracket 76 , persons of ordinary skill in the art will readily appreciate that in the case of embodiments including a secondary cam 96 ( FIG. 5 ), a secondary bracket (not shown) similar to the bracket 76 may be disposed on the screening machine 10 to be in cooperating relationship with the secondary cam 96 .
[0062] Accordingly, many further embodiments, applications and modifications of the invention will become readily apparent to those of ordinary skill in the art without departing from the scope of the invention and the inventors intend to be bound only by the claims appended hereto.
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A screening machine includes a vibratory carrier and a vibratory drive operatively coupled to the vibratory carrier for imparting vibratory motion thereto. The screening machine includes a screen assembly selectively coupled to the vibratory carrier so that the vibratory motion is transmitted to the screen assembly. A sealing mechanism including at least one rotary cam having a cam surface and at least one actuator being accessible to a user of said screening machine is coupled to the rotary cam. Actuation of the actuator to rotate the cam urges the screen assembly and the carrier into sealing engagement with a confronting surface of the screening machine. The screening machine further includes at least one stop positioned relative to the sealing mechanism to limit rotational movement of the rotary cam in at least one direction.
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RELATED APPLICATIONS
There are neither any previously filed nor currently co-pending applications in the world.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an ultrasonic stimulating pet toy and, more specifically, to an improved mouse-like pet toy comprising a sound chip assembly that emits ultrasonic vocalizations that stimulate a greater interaction by cats.
2. Description of the Related Art
Domestic cats are specialized hunters whose techniques require crypticity for success. Most domestic animals depend on both acoustic and visual cues to hunt prey; however, an importance of acoustic cues is especially emphasized for cats because they possess better acoustic discrimination abilities than dogs. Cats respond physiologically to higher-pitched sounds; scratches, noises and high-pitched mouse calls act upon an innate releasing mechanism which directs a cat's attention to a source of the sound. It isn't until after the cat's attention is gained when a moving source can elicit any pouncing movement by the cat.
Domestic cats make roving searches of their indoor environments in search of prey. There are many toys known in the art to encourage this natural, instinctive behavior. Other toys aim to also stimulate a cat's pouncing abilities as a form of playful interaction between the cat and a toy.
Because mice and birds are common prey hunted by cats, many of these toys take a form that resembles one of these natural preys. U.S. Pat. No. 6,371,053, to the present inventor, is such a toy, wherein a simulated, cloth mouse comprises a sound chip that emits a prerecorded sound in response to its engagement. Similar toys exist to resemble birds.
Although the high pitched squeak emitted from bird and mice toys appear to sound the same, birds and mice utter distinct and specialized vocalizations. The repetition rates, the number of repetitions, the frequencies and the intricate phrases that quantify the vocalizations vary between the two species. A study of the vocalization sequences made by mice shows that they emit ultrasonic vocalizations that display frequencies having unexpected richness. The present invention is a pet toy that comprises a means to replicate the vocalizations studied in mice, wherein a quantitative description of the studied vocalizations are used as the bases for the toy claimed herein.
SUMMARY OF THE INVENTION
It is an object of the present invention to teach an ultrasonic stimulating pet toy, wherein the pet toy comprises an improved sound emitted therefrom to resemble those emitted by mice.
It is an object of the present invention to comprise a mouse-like appearance such that the cat is encouraged to pounce on the prey after the sound spawns the cat's attention.
It is an object that the present means to emit sound replicates the ultrasonic vocalizations studied in mice. It is an object that the vocalizations produce sounds that stimulate a greater response from cats.
It is an object that the present toy emit ultrasonic vocalizations that utilize frequencies that approach 30 kHz because mice emit frequencies that range over 30-110 kHz.
It is an object that one embodiment of the present toy emit ultrasonic vocalizations that consist of a rapid series of chirp-like syllables in an audible range, preferred to be within the 30-110 kHz band. It is an object that these syllables are of varying length and are uttered at rates that approximate ten syllables per second. It is an object that one embodiment of the present invention comprise pitch-shifts in the vocalizations to be reminiscent of mice birdsong.
It is an object that the present toy be the one on the market that most closely elicits a same response by a cat as would a natural prey. It is an object that the present toy emit vocalizations at frequencies that engage a pet and, more specifically, one that orients the pet towards that locus. It is an object that the present invention is one that effectively exercises a pet when it attracts a pet to playfully pounce on it. It is an object that the present interactive toy stimulates the pet by utilizing both the pet's acoustic and visual cues.
It is a final object that the present invention provide all of the advantages that the foregoing objects entail.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and the features of the present invention are better understood with a reference to the following and more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:
FIG. 1 is an initial waveform of a โsqueakโ emitted from a prerecorded sound chip comprised in an ultrasonic stimulating pet toy according to a preferred embodiment of the present invention;
FIG. 2 is a waveform after 5.6 msec elapses;
FIG. 3 is a waveform after 28.3 msec elapses;
FIG. 4 is a waveform after 28.3 msec elapses;
FIG. 5 is a waveform after 40.5 msec elapses;
FIG. 6 is a waveform after 50.2 msec elapses;
FIG. 7 is a graph representing the frequency of the sound emitted from the present pet toy over a time; and,
FIG. 8 is a graph showing the same representation as that in FIG. 8 , wherein one โsqueakโ is measured.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
1. Detailed Description of the Figures
The present invention is an ultrasonic stimulating pet toy. It is preferred that the pet toy take a form that resembles a mouse in size, shape and general appearance. It is anticipated that the pet toy improves on a mouse taught in U.S. Pat. No. 6,371,053, to the present inventor and incorporated by reference as if fully rewritten herein, wherein a simulated, cloth mouse comprises a sound chip that emits a prerecorded sound in response to its engagement. While in the prior art, the sound chip is capable of emitting a purr, a meow, a recorded message, etc., the present invention improves on that toy by means of emitting a sound that more closely replicates the ultrasonic vocalizations studied in mice.
According to the results of research conducted on male mice at the Department of Anatomy and Neurobiology at Washington University School of Medicine, male mice emit ultrasonic vocalizations ranging over 30-110 kHz. The vocalizations have the characteristics of song, wherein they consist of several different syllable types having a temporal sequencing that includes an utterance of repeated phrases. The study recorded acoustical power and quantitatively represented it as a function of time and frequency. According to the study, male mice ultrasonic vocalizations consist of a rapid series of โchirp-likeโ syllables in the 30-110 kHz band, wherein syllables of varying duration (approximately 30-200 ms) are uttered at rates of about ten per second. Most syllables involve rapid sweeps in frequency and relatively sudden, large changes (โjumpsโ) in frequency.
It is an object of the present toy to emit a sound recording that closely replicates this study's results so that the cat's acoustic and visual abilities are engaged. Improvements to the present sound chip are that it cycles a sound longer, it cycles a sound in repeated patterns and it cycles the sound in random patterns.
An analysis of a vocalization (โsqueakโ) of the present invention is shown in FIGS. 1-6 . The analysis shows the measurements made to the present mouse-like pet toy when a prerecorded sound chip contained therein emitted a squeak. The squeak is triggered by a motion sensor comprised in the pet toy. One squeak produces an audio waveform that lasts approximately 100 msec.
FIG. 1 shows an initial waveform produced by the squeak, wherein the waveform lasts for 5.6 msec. The piezo element is driven by a nominal square wave with a frequency of 6.1 kHz. An amplitude for the wave is shown in FIG. 1 to be 6.4 Vp-p*.
As time elapses, the frequency increases and decreases. These changes are shown in FIGS. 2-6 and they produce a characteristic โsqueakโ sound. The frequency at 5.6 msec increases to 6.54 kHz. FIG. 3 is missing. FIG. 4 shows a waveform after 28.3 msec of time elapsed. The frequency increases to 8.26 KHz. at this time. FIG. 5 shows the waveform after 40.5 msec elapses, wherein the frequency increases to 9.7 kHz. The waveform increases to 11.4 kHz, as shown in FIG. 6 , after 50.2 msec elapses.
The frequency increases and decreases shown in FIGS. 2-6 are charted in FIG. 7 . The graph shown in FIG. 7 charts a representation of the frequency over the time elapsed. In the present toy, it is envisioned that the sound module comprised therein emits a sound recording in the form of an audible squeak every time a motion sensor senses a form of engagement. A squeak approximates 100 msec. FIG. 7 shows the present sound chip retriggered after a completion of the first squeak. FIG. 8 is a graph showing the same representation as that of FIG. 7 , except that a frequency over time is represented for only a first squeak.
According to the analysis of the squeak comprised in the present pet toy, an audio amplitude is typically 100 dB at 6 cm (at 7 kHz), wherein a measurement was conducted when the speaker was removed from the toy. The output shows to be very directional and it decreases as the frequency increases.
The piezo element is driven by a bridge circuit, causing it to result in a peak-to-peak voltage across the element of about 6.2 V. The present configurations provide for a higher volume without increasing battery voltage.
It should be noted that the data presented in the present disclosure is considered only typical; however, there are dramatic differences in frequency, in timing and in output levels among a plurality of product samples. It is envisioned that this vocalization is similar to the characteristic syllabic and temporal structures of real mice. In a preferred embodiment, the present toy emits ultrasonic vocalizations that utilize frequencies that approach 30 kHz. In alternate embodiments, it is envisioned that a squeak also consists of a plurality of rapid chirp-like syllables in and audible range.
The foregoing descriptions of the specific embodiments of the present invention are presented for the purposes of illustration and description. They are neither intended to be exhaustive nor to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments are chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and its various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and to their equivalents. Therefore, the scope of the invention is limited only by the following claims.
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The present invention relates generally to an ultrasonic stimulating pet toy and, more specifically, to a mouse-like pet toy comprising a sound chip assembly that emits ultrasonic vocalizations that replicate those studied in mice. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for producing at least one fluid contained in a geological formation by means of substantially horizontal drains, when this formation contains at least a second fluid which risks hindering production of the first.
In this description, the term "drain" is essentially used for designating an artificial well serving for draining a formation, this well possibly comprising over a portion of its length at least one perforated tube.
However, the present invention may be applied to a natural drain, if it has an appropriate form and layout.
2. Description of the Prior Art
When it is desired to produce one of two fluids present, for example oil, there occurs under the effect of the pressure gradient due to the desired flow of the fluid to be recovered, a deformation of the surface separating the two fluids which will be termed ridge effect. This is described in the article by Mr. GIGER entitled "EVALUATION THEORIQUE DE L'EFFET D'ARETE D'EAU SUR LA PRODUCTION PAR PUITS HORIZONTAUX" published in the revue of the French petroleum institute vol. 38, No 3, pages 361-370, May-June 1983, Paris (France). This ridge effect may cause a breakthrough of the undesired fluid and, consequently, the production of the undesired fluid in considerable proportions which may adversely effect working of the oil from an economic point of view.
The present invention avoids this disadvantage.
The prior art may be illustrated by the following U.S. Pat. Nos. 2,889,880; 3,638,731 and 2,855,047.
The methods described in these prior patents require the formation impregnated by the different fluids (gas, oil, water) to have passing therethrough the same oil used for producing the desired fluid, even if the production is made selective by addition of plugs and tubes.
These methods are defective and without effect if the geological formation is brought into yield by means of horizontal or very slanted drains.
More precisely, the present invention provides a method for producing a first fluid or desired fluid contained in a geological formation, this formation further comprising at least a second fluid or undesired fluid which risks hindering production of the first fluid, this first fluid being produced by means of at least one deflected or substantially horizontal first drain.
SUMMARY OF THE INVENTION
The method of the invention consists in disposing at least a second deflected or substantially horizontal drain in said geological formation, this second drain being situated between the first drain and the undesired fluid so as to produce a part at least of the undesired fluid and so as to allow the first drain to produce at least partially the desired fluid and preferably essentially the desired fluid.
The second drain may be situated, at least over a part of its length, in the desired fluid.
The second drain may also be placed, at least over a portion of its length, at the interface defined by the contact surface of the desired fluid and of the undesired fluid.
Similarly, the second drain may be situated at least partially in the undesired fluid.
The second drain will be placed advantageously so as to be substantially parallel to the first drain over at least a portion of its length.
In the case where the desired fluid is included between two other fluids likely to hinder the production, several drains may be disposed in accordance with the invention between the first drain, for producing the desired fluid and the other fluids so as to draw off a part at least of these other two fluids.
It is of course possible, in accordance with the invention, to use several drains for producing the first fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood and its advantages will appear more clearly from the following description which is now limitative and which is illustrated by the accompanying Figures in which:
FIG. 1 illustrates a geological formation comprising two fluids,
FIG. 2 illustrates schematically the deformation of the interface separating the two fluids during production of one of them by means of a horizontal drain,
FIGS. 3 to 5 show how the production of a fluid to be worked is by the presence of fluids, and
FIGS. 6 to 11 illustrate schematically the method of the present in different cases.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following embodiment of the present invention relates to the case of a geological formation 1 containing several immiscible fluids, for example at least two fluids, a first fluid A, such as oil, designated by the reference numeral 2 in FIG. 1 and a second fluid B, such as water, designated by reference numeral 3. The impermeable geological formation which forms the roof of the reservoir containing fluids A and B is designated by the reference numeral 4.
Fluids A and B, particularly, because of their difference in density are separated vertically inside layer 5.
Reference numeral 6 designates the interface between the two fluids A and B.
When it is desired to produce only one of the two fluids, fluid A for example, by means of at least one horizontal production drain 7 (FIG. 2), a deformation 8 of the interface 6 separating the two fluids appears under the effect of the pressure gradient due to the flow of the fluid to be recovered. Interface 6 tends to draw closer to the horizontal production drain 7.
This phenomenon, which will be termed ridge effect, may cause a breakthrough of the undesired fluid B and two-phase production which may make working of the desired fluid A economically not worth while.
Numerous studies, by calculation or by using physical or analogical models, have shown that this phenomenon appears for a certain value of the drawing off flow-rate of fluid A to be produced, called critical flow.
It can be observed that as long as the flow of drain 7 remains lower than the critical flow, the surface separating the two fluids tends towards a stable position and does not reach drain 7. Thus, drain 7 produces only the desired fluid A.
When the flow exceeds the limit of the critical flow, the surface 8 separating the two fluids reaches drain 7 which begins to produce simultaneously fluids A and B as is shown in FIG. 3 in the case where fluid A to be produced is less dense than fluid B. FIG. 4 illustrates the opposite case, that is to say when the fluid A to be produced is denser than fluid B.
In these two cases, the interface 6 is deformed from the initial position shown with a broken line to reach the production drain 7 and thus hinder the production of fluid A. In some cases, drain 7 may produce mostly the undesired fluid B.
Several formulae have been proposed for characterizing the critical flow. Built up-from typical groups of physical variables, these formulae bring out an important parameter: the distance between the perforations of drain 7 and the initial separation plane 6 of the two fluids A and B (water clearance when fluid B is water).
So as to eliminate or reduce this ridge formation phenomenon and to increase the clearance from the undesired fluid, and the value of the critical flow, a method is proposed whose description follows.
The part of the reservoir rock which contains fluid A which it is desired to produce is brought into yield by means of at least one horizontal drain 7, with a drawing off flow which causes the deformation 8 of the separation surface 6 of the two fluids A and B present.
The horizontal drain 7 intended for producing the desired fluid A is drilled preferably as far as possible from surface 6 separating the two fluids A and B present.
If fluid A which it is desired to produce is less dense than fluid B, the production will take place in the upper part of the zone to be produced. On the other hand, if the fluid A to be produced is denser than fluid B, the horizontal drain bringing the fluid A to the surface will be drilled in the lower part of the zone to be produced.
In the case where fluid A to be produced is situated in a zone of the reservoir rock between a zone containing a fluid B less dense than fluid A and a zone containing a fluid C denser than fluid A (FIG. 5), the horizontal drain for producing fluid A will be drilled approximately at equal distances from the separation surfaces of fluids 6 and 6A respectively (see FIG. 5).
However, this position is not imperative. It is also possible to position the production drain by taking into account the characteristics related to the different fluids, such as density, viscosity, . . .
The method proposed consists in bringing into production, simultaneously with the bringing into production of the zone containing fluid A which it is desired to recover, the zone containing fluid B which forms an obstacle to the production of fluid A in the horizontal drain drilled for this purpose.
The production of the undesired fluid B and/or C will take place through at least a second substantially horizontal drain 10 separate from the preceding one.
This additional drain intended to modify the pressure field, so the flows of the fluids in the vicinity of the horizontal drain 7 for producing fluid A, will be drilled substantially parallel to the preceding one so as to have constant efficiency over the whole width of the drain 7 brought into production.
The position of this additional drain 10 and the drawing off flow which it will convey may be advantageously determined by means of numerical models simulating the polyphase flows in the porous media, so that the proportion of undesired fluid B in the production of drain 7 producing fluid A is minimum.
EXAMPLE OF IMPLEMENTING THE METHOD
1. A substantially horizontal drain 7 is drilled in the zone containing the fluid A which it is desired to produce.
2. Depending on the drawing off rate desired in this horizontal drain 7, the number, position and drawing off rate of other horizontal drains 10 to be drilled are determined if required for example by using numerical models, so as to eliminate or reduce the proportion of undesired fluids in drain 7 the desired fluid.
3. The additional drains defined a step 2 are drilled either from wells already existing or from new wells.
4. The drain intended to produce the desired fluid A is brought into production depending on the desired flow rate.
5. The other drains are brought into production for eliminating or limiting the production of undesired fluid B in the drains brought into production at step 4.
6. Adjustment of the flow rate of the drains brought into production at step 5 so that the proportion of undesired fluids in drain 7 brought into production at 4 is at a minimum.
FIGS. 6, 8 and 10 show three possible configurations of the geological formation to be worked, either respectively the case where the desired fluid A has a density less than that of the undesired fluid B, the opposite case, that is to say when the density of fluid A is greater than that of fluid B and finally, the case where the desired fluid A has a density greater than that of a first undesired fluid B but less than that of a second undesired fluid C.
In these three Figures have been shown the additional drain or drains 10 and 10a intended to produce at least partially the undesired fluid or fluids.
It will be noted that in these three Figures the case has been shown where drain 7 is brought into production and not the drawing off drain 10. This explains that the undesired fluid or fluids B or C reach the production drain 7 of the desired fluid A.
Furthermore, it will be noted that in the three FIGS. 6, 8 and 10 the drain or drains 10, 10a for drawing off the undesired fluids B and/or C have been placed in the desired fluid A and, preferably, proximate the separation surface before working shown with broken lines.
Still within the scope of .the invention, the drawing off drain or drains 10 may be placed substantially on the separation surface or surfaces of the fluids (A/B and/or A/C), before working, or in the undesired fluid or fluids B and/or C, over at least a portion of their length.
The distances separating the different drains from each other and the drains from the interfaces defined by the different fluids (A, B and C), as well as the drawing off and production rates may be determined depending on the characteristics of the formation, of the fluids, and/or of the equipment used for working, more particularly for optimizing the production of the desired fluid A and possibly minimizing the drawing off of the undesired fluid or fluids or minimizing the proportion of the desired fluid A produced by the drawing off drain or drains 10.
FIGS. 7, 9 and 11 correspond to FIGS. 6, 8 and 10, the difference residing in the method of working the drawing off drains.
During drawing off, the interfaces 8 and 8a are deformed in the vicinity of drains 10 which produce, as shown by the arrows, a portion at least of the undesired fluid B or C. Thus, the production drains 7 produce esentially a desired fluid A, as shown by the arrows.
Still within the scope of the invention, the different separation surfaces between the fluids and those separating the fluids and the walls of the geological formation may not be horizontal. In this case, the different drains may be placed parallel to these surfaces.
Of course, it is possible in accordance with the invention to use several drains 7 for producing the desired fluid A.
It is also possible in accordance with the invention to bring first of all into production the drains 7 for producing the desired fluid A then during working from a certain moment which may correspond for example to a critical deformation of interface 6, the drawing off drains 10 may be worked.
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A method is provided for producing at least a first fluid or desired fluid contained in a geological formation this formation further comprising at least a second fluid, or undesired fluid, which risks hindering production of the desired fluid, this latter being produced by means of at least one deflected or substantially horizontal drain.
According to this method, a second drain is disposed in said geological formation, this second drain being situtated between the first drain and the undesired fluid for drawing off a part at least of the undesired fluid and allowing the first drain to produce essentially the desired fluid.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of copending U.S. patent application Ser. No. 12/177,252, filed on Jul. 22, 2008, which itself is a continuation application of U.S. patent application Ser. No. 11/345,159 (now U.S. Pat. No. 7,512,395), filed on Jan. 31, 2006, the contents of both of which are hereby fully incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to data transmission over wireless radio links, and more particularly to a detector and receivers for providing fast data transmission over wireless radio links.
BACKGROUND OF THE INVENTION
[0003] Gigabit-rate data transmission has been achieved in the 60-GHz Industrial, Scientific, and Medical (ISM) band using ASK modulation with transceiver modules consisting of several GaAs integrated circuits (ICs) mounted on a ceramic substrate. An example of such prior art technology can be found in a publication by K. Ohata et al., โWireless 1.25 Gb/s Transceiver Module at 60-GHz Bandโ. It is a goal of the present invention to provide a single-IC receiver or transceiver in less expensive silicon process technology which supports multiple modulation formats, including ASK modulation.
[0004] Product detectors are well known in the literature for detection of ASK or AM signals. Examples of such detectors in the prior art include an excerpt from Solid - State Radio Engineering by Krauss, Bostian, and Raab, and from Radio - Frequency Electronics by Hagen. This disclosure describes an improved product detector which is capable of operation at gigabit data rates and with good linearity on millivolt-level IF input signals, which has high input impedance so as not to detune the IF input circuit to which it is connected, and which can be easily powered down so as not to load the IF input circuit or consume power when the receiver is used in other modulation modes.
SUMMARY OF THE INVENTION
[0005] This disclosure relates to the goal of providing gigabit-rate data transmission over wireless radio links, using carrier frequencies in the millimeter-wave range (>30 GHz). More specifically, it describes a circuit for detection of amplitude-shift keyed (ASK) or other amplitude modulations (AM) which can be easily incorporated into an integrated circuit receiver system, making the receiver capable of supporting both complex IQ modulation schemes and simpler, non-coherent on-off or multiple-level keying signals.
[0006] This disclosure also describes several novel radio architectures which, with the addition of a frequency discriminator network, have the capability of handling frequency shift keyed (FSK) or other frequency modulations (FM), as well as AM and complex IQ modulation schemes. These radio architectures support this wide variety of modulations by efficiently sharing detector hardware components. The architecture for supporting both quadrature down-conversion and ASK/AM is described first, followed by the ASK/AM detector circuit details, then the AM-FM detector architecture, and finally the most general AM-FM/IQ demodulator system concept and the FSK/FM detector circuit details.
[0007] In one aspect, the present invention broadly contemplates a receiver, comprising a first stage down-conversion mixer, a mixer as the detector, an amplifier in the mixer's RF-input signal path, an amplifier in the mixer's LO-input signal path, wherein the amplifier in the mixer's RF-input signal path provides a low-gain, linear path to the mixer's RF-input, wherein the amplifier in the mixer's LO-input signal path provides a high-gain path to the mixer's LO-input, and wherein both amplifiers have matched delays.
[0008] In another aspect, the present invention broadly contemplates an integrated radio receiver device comprising a first stage down-conversion mixer; an optional IF amplifier; an IQ down-converter; an AM detector at the output of the first stage down-conversion mixer or optional IF amplifier; and a multiplexing capability of an I/Q channel down conversion and a detected AM envelope into a baseband amplification chain. The IF amplifier may act as both an amplifier and a filter. The signal is commonly band-limited prior to detection for optimum performance, and this band-limiting normally happens at IF.
[0009] In a third aspect, the present invention broadly contemplates a receiver, comprising a first stage down-conversion mixer, a double balanced mixer as the detector; an amplifier in the mixer's RF-input signal path; an amplifier in the mixer's LO-input signal path; wherein the amplifier in the mixer's RF-input signal path provides a low-gain, linear path to the mixer's RF-input; wherein the amplifier in the mixer's LO-input signal path provides a high-gain path to the mixer's LO-input, wherein both amplifiers have matched delays.
[0010] In a fourth aspect, the present invention broadly contemplates an AM-FM detector comprising a merger which merges an AM product detector with a delay-line FM detector, such that the AM product detector hardware is re-used in the delay-line FM detector; wherein the FM detector is implemented using only an additional discriminator phase shift network.
[0011] In a fifth aspect, the present invention broadly contemplates an integrated radio receiver device, comprising a first stage down-conversion mixer; an optional IF amplifier; an IQ down-converter; an AM detector at the output of the first stage down-conversion mixer or optional IF amplifier; and an FM detector at the output of the first stage down-conversion mixer or optional IF amplifier, wherein the device supports more than one type of modulation scheme.
[0012] For a better understanding of the present invention, together with other and further features and advantages thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, and the scope of the invention will be pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an overall system block diagram of a presently preferred embodiment of the present invention.
[0014] FIG. 2 is a product detector that can be found in the prior art.
[0015] FIG. 3 is another product detector that can be found in the prior art.
[0016] FIG. 4 is a product detector implementation of a presently preferred embodiment of the present invention.
[0017] FIG. 5 is a circuit implementation of a product detector of a presently preferred embodiment of the present invention.
[0018] FIG. 6 is a screenshot of simulation results for a receiver of an embodiment of the instant invention.
[0019] FIG. 7 is a screenshot of simulation results for a receiver of another embodiment of the instant invention.
[0020] FIG. 8 is an overall system block diagram of another presently preferred embodiment of the present invention.
[0021] FIG. 9 is a product detector implementation of another presently preferred embodiment of the present invention.
[0022] FIG. 10 is a more specific implementation of the product detector of FIG. 9 .
[0023] FIG. 11 is an overall system block diagram of another presently preferred embodiment of the present invention.
[0024] FIG. 12 is a circuit implementation of the embodiment of FIG. 11 .
[0025] FIG. 13 is a more detailed schematic of the amplifier of FIG. 12 .
[0026] FIG. 14 is a more detailed circuit implementation of the discriminator filter of FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] FIG. 1 shows our novel radio architecture incorporating both quadrature down-conversion and an active ASK/AM detector at the intermediate frequency. The ASK/AM detector output is multiplexed with the I-channel down-conversion output to enable re-use of the existing baseband low-pass filter and amplifier to filter and amplify the detected ASK/AM signal. An integrated AM detector increases the application space of a 60 GHz receiver by providing the ability to detect non-coherent on-off keying signals and other amplitude-shift-keyed modulations. These non-coherent modulation formats simplify a radio system design by eliminating the need for carrier phase recovery or other complex baseband IQ signal processing to demodulate received data. ASK/AM formats are suitable for highly directional wireless data links which do not suffer from interfering or reflected signals. Complex baseband IQ signal processing, on the other hand, provides the capability of rejecting interfering and reflected signals, as might be required in an omni-directional wireless data link. Thus, a receiver capable of detecting both modulation modes has wider application.
[0028] FIGS. 2 and 3 show product detectors that might be used as the ASK detector in FIG. 1 , as described in prior art. FIG. 2 is a conceptual diagram showing the modulated input signal ( 12 ) applied to both inputs of a mixer ( 13 ). Without specifying the implementation details of the mixer, it is impossible to know the transfer function of this arrangement, but if the mixer has equal conversion gains through both inputs, then the output signal ( 14 ) is the square of the input signal, an approximation of the desired absolute value function.
[0029] Many practical mixer circuits do not have equal conversion gains through both inputs, but rather require a relatively large amplitude signal through one input (the LO-input in FIGS. 2-4 ) and provide a relatively high conversion gain and a linear response characteristic through the other input (the RF-input in FIGS. 2-4 ). FIG. 3 shows a more realistic product detector which uses a limiter or limiting amplifier ( 18 ) to provide an approximately constant input signal level to the mixer's LO-input ( 17 ). If the mixer's LO-input has a sufficiently large signal level, this circuit provides a closer approximation to the desired absolute value function.
[0030] The circuit in FIG. 3 will not work properly at high data rates and low input-signal levels because it does not provide a capability for time-aligning the mixer's RF- and LO-input signals ( 16 and 17 , respectively). If the two input signals to the mixer are misaligned, the detector's output amplitude is reduced and the output pulse is broadened, lowering the detector's effective bandwidth. Circuit simulations indicate that alignment of the two signals within 10-20 degrees of a cycle at the highest input modulation frequency is desirable, which corresponds to 28-56 ps at a modulating frequency of 1 GHz. An improved product detector which provides the capability of time-aligning the input signals is shown in FIGS. 4 and 5 . This improved product detector also has high input impedance so as not to detune the IF input circuit to which it is connected, and it can be easily powered down so as not to load the IF input circuit or consume power when the receiver is used in other modulation modes, all features which are advantageous for practical implementation of the architecture in FIG. 1 .
[0031] Referring to FIG. 5 , our implementation of the ASK/AM detector includes a double balanced mixer ( 26 ) as the detector, and amplifiers in the mixer's RF- and LO-input signal paths, labeled amplifier 1 ( 27 ) and amplifier 2 ( 28 ), respectively. Amplifier 2 ( 28 ) provides a relatively high-gain path to the mixer's LO-input, while amplifier 1 ( 27 ) provides a relatively lower-gain, linear path to the mixer's RF-input. The two amplifiers are designed to have matched delays. This is accomplished by using amplifiers which are topologically similar. Resistor R 12 ( 68 ) reduces the gain and linearizes amplifier 2 ( 28 ), which consists of Q 8 - 11 ( 37 - 40 ) and R 10 - 14 ( 66 - 70 ), while C 5 (optional) ( 84 ) helps to match the delays and bandwidths of amplifiers 1 ( 27 ) and 2 ( 28 ). That is, the inclusion of degeneration resistor R 12 ( 68 ) may increase the bandwidth and reduce the delay of amplifier 1 ( 27 ) due to the negative feedback it creates, and the inclusion of C 5 ( 84 ) increases the delay and reduces the bandwidth of amplifier 1 ( 27 ) to match amplifier 2 ( 28 ), compensating for R 12 ( 68 ). In many cases, C 5 ( 84 ) may be unnecessary, and the amplifier delays may be adequately matched due to the topological similarity.
[0032] FIG. 4 shows the general circuit architecture which has been implemented in FIG. 5 , with Amplifier 1 ( 20 ) in FIG. 4 corresponding to Amplifier 1 ( 27 ) in FIG. 5 , etc. The detailed circuit in FIG. 5 also includes an optional input buffer amplifier ( 29 ) to raise the input impedance of the circuit, so that it does not load or detune the IF circuitry in FIG. 1 .
[0033] Circuit simulations were performed on the entire receiver with ASK demodulator, the partial block diagram of which is shown in FIG. 1 . The detailed circuit which was actually simulated included a low-noise amplifier with a gain of 20 dB preceding the RF-input ( 1 ) shown in FIG. 1 . The mixer ( 2 ) and the IF amplifier ( 4 ) each have a gain of 10 dB, for a total of 40 dB gain between the LNA input and the IF amplifier output. The circuit was simulated for LNA-referred signal levels of โ65 dBm to โ35 dBm, which resulted in IF signals in the range of 5-500 mV peak at the ASK detector input. The RF-input frequency was 64 GHz and the IF 9.1 GHz.
[0034] The simulation results shown in FIG. 6 are for a 1 GHz sinusoidal amplitude modulation of the RF input with 0.9 modulation index. The lower trace ( 87 ) in FIG. 6 is the IF waveform (amplitude vs. time), the middle trace ( 88 ) is ASK detector output waveform, and the top trace ( 89 ) is the detected ASK output after low-pass filtering and amplification through the baseband amplifier. It can be seen that the circuit in FIG. 5 closely approximates the absolute value of the input signal, which when low-pass filtered re-generates the AM or ASK signal. A 1 GHz sinusoidal modulation is roughly equivalent to on-off (2-level ASK) keying at 2 Gb/s.
[0035] The simulation results shown in FIG. 7 are for the entire receiver with the integrated product detector, using a 4-level ASK input at 2 G Symbols/s, which is equivalent to a data rate of 4 Gb/s. The lower trace ( 90 ) is the RF input waveform (amplitude vs. time) showing four amplitude levels, the 2 nd from the bottom ( 91 ) is the IF waveform, the 3 rd from the bottom ( 92 ) is the ASK detector output waveform, and the top ( 94 ) is the demodulated ASK output after amplification and low-pass filtering through the baseband amplifier, showing four distinct demodulated levels.
[0036] There is extensive prior art for AM/ASK detectors, as exemplified by numerous references above. The majority of patented circuits are diode-based, such as U.S. Pat. No. 3,691,465 to McFadyen, U.S. Pat. No. 4,000,472 to Eastland, U.S. Pat. No. 4,250,457 to Hofmann, U.S. Pat. No. 4,320,346 to Healey, U.S. Pat. No. 4,359,693 to Sauer, U.S. Pat. No. 4,492,926 to Kusakabe. Other detectors use means other than diodes to achieve rectification, including U.S. Pat. No. 3,673,505 to Limberg, U.S. Pat. No. 3,965,435 to Kriedt, U.S. Pat. No. 4,320,346 to Healey. Among product detectors (that is, mixer- or multiplier-based detectors), including U.S. Pat. No. 3,705,355 to Palmer, U.S. Pat. No. 3,792,364 to Ananias, U.S. Pat. No. 6,230,000 to Tayloe, none were found which employ the matched delay circuitry shown in FIGS. 4-5 of the present invention.
[0037] The concepts in this disclosure can be extended to include detection of FSK/FM signals as well, with the addition of a discriminator phase-shift network, as shown in FIG. 8 . The FSK/FM detector ( 94 ) is built using many of the same components as the earlier ASK/AM detector. The phase-shift network H(f) ( 98 ) is designed to have 90ยฐ of phase shift at the IF carrier frequency. This circuit is well known in the literature and is variously called a delay-line FM detector or quadrature FM demodulator.
[0038] FIG. 9 shows how this delay-line FM detector can be merged with an AM product detector into a radio architecture which can demodulate either ASK/AM or FSK/FM signals. Referring to FIG. 9 , closing the switch Sw 1 ( 104 ) and opening switches Sw 2 ( 105 ) and Sw 3 ( 106 ) configures the detector as an AM product detector as shown in FIG. 3 . Closing Sw 2 ( 105 ) and Sw 3 ( 106 ) and opening Sw 1 ( 104 ) configures the detector as a delay-line FM detector, as shown in FIG. 8 .
[0039] FIG. 10 shows a more specific implementation of the AM-FM detector architecture which includes the improved AM product detector described in FIGS. 4 and 5 . In FIG. 10 , the two amplifiers used to time-align the input signal in FIG. 4 (Amp 1 ( 20 ) and Amp 2 ( 21 )) are shown here explicitly as โlinear ampโ ( 113 ) (corresponding to Amp 1 ( 20 ) in FIG. 4 ) and โlimit ampโ ( 118 ) (corresponding to Amp 2 ( 21 ) in FIG. 4 ). Also, one possible realization of the discriminator phase-shift network H(f) ( 117 ) is shown for a 9-GHz IF, which is the frequency used in our receiver. Referring to FIG. 10 , closing the switch Sw 1 ( 114 ) and opening switches Sw 2 ( 115 ) and Sw 3 ( 116 ) configures the detector as an AM product detector as shown in FIG. 4 . Closing Sw 2 ( 115 ) and Sw 3 ( 116 ) and opening Sw 1 ( 114 ) configures the detector as a delay-line FM detector, as shown in FIG. 8 .
[0040] FIG. 11 is the most general receiver architecture described. It supports three different modulations: complex IQ modulation schemes, ASK/AM, and FSK/FM. With switches SwI ( 124 ) and SwQ ( 127 ) closed (and the others open), the architecture provides IQ demodulation. With SwAM ( 125 ) closed (and the others open), AM demodulation is provided. With SwFM ( 126 ) closed (and the others open), FM demodulation is provided. With both SwAM ( 125 ) and SwFM ( 127 ) closed (and the others open), simultaneous AM and FM demodulation is provided, which potentially increases the non-coherent data rate by a factor of two. Although not explicitly shown, it should be understood that the improved ASK/AM detector of FIG. 4 could be used in FIG. 11 by providing amplifiers with matched delays in the ASK/AM mixer signal paths. For simultaneous AM and FM demodulation, the AM detector should be as frequency insensitive as possible to limit leakage of FM into its detected output level, and the FM detector should be as amplitude insensitive as possible to limit leakage of AM into its detected output level.
[0041] FIG. 12 shows a specific, transistor-level implementation of our FM detector, which was implemented as part of the receiver architecture in FIG. 11 . This general type of FM detector is variously known as a delay-line FM detector, or quadrature FM demodulator, or FM limiter-discriminator, and is well known in the literature. Our improved circuit uses a three-stage limiting amplifier ( 137 ), each stage of which has amplitude dependent gain. The amplitude-dependent gain provides relatively high gain for low amplitude input signals and lower gain for higher-amplitude input signals. This amplitude-dependent gain provides a more gradual clipping characteristic for higher-amplitude input signals, which minimizes the asymmetry and second-order distortion products present in the output signal, while still providing effective limiting for lower-amplitude input signals. Any asymmetry or second-order distortion in the output signal results in an amplitude-dependent DC offset in the limiter output, which results in poorer rejection of amplitude-modulated signals and a lower signal-to-noise ratio. Thus, our improved limiting amplifier preserves high signal-to-noise ratio in the presence of AM signals, which would be very important in systems which used simultaneous AM and FM modulation, as shown in FIG. 11 .
[0042] FIG. 13 reveals details of the limiting amplifiers. Each amplifier stage has two pairs of input transistors, one pair of which is resistively degenerated (Q 1 ( 139 ), Q 3 ( 141 ) and R 3 ( 149 )) and one pair of which is not (Q 2 ( 140 ), Q 4 ( 142 )). The non-degenerated pair provides high gain for small input signals until the input-signal amplitude reaches the point where the pair's differential output current saturates. The degenerated pair provides lower gain but will accept a larger signal before it saturates. Thus, the overall amplifier's clipping characteristic is made more gradual, providing lower DC offset and fewer second-order distortion products at the output.
[0043] FIG. 14 shows the specific circuit implementation of the discriminator filter used in FIG. 12 . It is designed to have 90 degrees of phase shift at the center frequency of 8.9 GHz and provide a phase shift which is linear with deviation in input frequency about this center frequency, over a range up to ยฑ2 GHz. This is a practical differential, on-chip implementation of the theoretical network shown in the FIG. 10 inset.
[0044] If not otherwise stated herein, it is to be assumed that all patents, patent applications, patent publications and other publications mentioned and cited herein are hereby fully incorporated by reference herein as if set forth in their entirety herein.
[0045] Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention.
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Provision of gigabit-rate data transmission over wireless radio links, using carrier frequencies in the millimeter-wave range (>30 GHz). More specifically, a circuit for detection of amplitude-shift keyed (ASK) or other amplitude modulations (AM) which can be easily incorporated into an integrated circuit receiver system is described, making the receiver capable of supporting both complex IQ modulation schemes and simpler, non-coherent on-off or multiple-level keying signals. Several novel radio architectures are also described which, with the addition of a frequency discriminator network, have the capability of handling frequency shift keyed (FSK) or other frequency modulations (FM), as well as AM and complex IQ modulation schemes. These radio architectures support this wide variety of modulations by efficiently sharing detector hardware components. Disclosed herein are architecture for supporting both quadrature down-conversion and ASK/AM, ASK/AM detector circuit details, AM-FM detector architecture, and an AM-FM/IQ demodulator system and FSK/FM detector circuit details.
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FIELD OF THE INVENTION
[0001] The present invention relates to flexible printed circuits (FPCs) for liquid crystal display (LCD) devices, and more particularly to a flexible printed circuit with increased signal bandwidth and a liquid crystal display device using the same.
GENERAL BACKGROUND
[0002] Liquid crystal displays are commonly used as display devices for compact electronic apparatuses, because they not only are very thin but also provide good quality images with little power.
[0003] A typical LCD device includes a liquid crystal display panel, and a backlight module disposed adjacent to the liquid crystal display panel. A plurality of source electrodes and a plurality of gate electrodes are disposed on the liquid crystal display panel. Each source electrode includes a source electrode driving integrated circuit (IC). Each gate electrode includes a gate electrode driving IC. An FPC is generally used in an LCD device for joining the liquid crystal display panel and a printed circuit board (PCB).
[0004] Referring to FIG. 6 , a conventional LCD 100 includes a liquid crystal display panel 11 , a backlight module 150 disposed adjacent to the liquid crystal display panel 11 , a frame 160 containing the backlight module 150 , a PCB 130 disposed adjacent to the frame 160 , an FPC 1 joining the liquid crystal display panel 11 and the PCB 130 , and a driving IC 15 disposed on the FPC 1 .
[0005] Referring to FIG. 7 , the FPC 1 includes a substrate 10 , a plurality of input lines 120 , a plurality of output lines, 140 , and a resin layer 16 . The substrate 10 includes a first joint part 12 for joining to the PCB 130 , and a second joint part 14 for joining to the liquid crystal display panel 11 . The input lines 120 are formed on the first joint part 12 . The output lines 140 are formed on the second joint part 14 . The input lines 120 and output lines 140 are electrically conductive.
[0006] The driving IC 15 is disposed in a middle region of the substrate 10 . The input lines 120 of the FPC 1 are joined to the PCB 130 , and are also joined to the driving IC 15 for signal transmission from the PCB 130 to the driving IC 15 . The output lines 140 of the FPC 1 are joined to the liquid crystal display panel 11 , and are also joined to the driving IC 15 for signal transmission from the driving IC 15 to the liquid crystal display panel 11 . The resin layer 16 covers areas of both the input lines 120 and the output lines 140 that are around the driving IC 15 . An aligning mark 18 is formed beside the output lines 140 .
[0007] The input lines 120 and the output lines 140 are all rectangular, and a certain distance must be provided between each two adjacent input lines 120 and each two adjacent output lines 140 in order to avoid short circuits. When the number of driving signals is large, the areas of the first joint part 12 and the second joint part 14 must be correspondingly large in order to contain the large number of input and output lines 120 , 140 that are needed for providing the large signal bandwidth. This results in a correspondingly very wide FPC 1 , and may render the LCD 100 unsuitable for certain compact electronic apparatuses.
[0008] What is needed, therefore, is a flexible printed circuit and a liquid crystal display device using the same that overcome the above-described deficiencies.
SUMMARY
[0009] In an exemplary embodiment, a flexible printed circuit includes a substrate. The substrate includes a plurality of first conductive lines and second conductive lines. The first conductive lines include a plurality of first patches. The second conductive lines include a plurality of second patches. The first patches are arranged side by side oppositely oriented relative to each other in alternating fashion. The second patches are arranged side by side oppositely oriented relative to each other in alternating fashion. The first conductive lines may for example be input lines, and the second conductive lines may for example be output lines.
[0010] Assuming that a size of the FPC of the exemplary embodiment is the same as a size of a conventional FPC, the amount of input lines of the FPC of the exemplary embodiment can be approximately twice the amount of input lines of the conventional FPC. Similarly, the amount of output lines of the FPC of the exemplary embodiment can be approximately twice the amount of output lines of the conventional FPC. Thus, the signal bandwidth of the FPC of the exemplary embodiment can be approximately twice the signal bandwidth of the conventional FPC.
[0011] In another exemplary embodiment, a liquid crystal display device includes a liquid crystal display panel and a flexible printed circuit joined to the liquid crystal display panel. The flexible printed circuit includes a substrate. The substrate includes a plurality of first conductive lines and second conductive lines. The first conductive lines include a plurality of first patches. The second conductive lines include a plurality of second patches. The first patches are arranged side by side oppositely oriented relative to each other in alternating fashion. The second patches are arranged side by side oppositely oriented relative to each other in alternating fashion.
[0012] Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic, side cross-sectional view of part of a liquid crystal display device using an FPC according to a first embodiment of the present invention.
[0014] FIG. 2 is a schematic, top plan view of the FPC of FIG. 1 when the FPC is laid out flat.
[0015] FIG. 3 is a schematic, side cross-sectional view corresponding to line III-III of FIG. 2 .
[0016] FIG. 4 is a schematic, top plan view of an FPC according to a second preferred embodiment of the present invention.
[0017] FIG. 5 is a schematic, top plan view of an FPC according to a third preferred embodiment of the present invention.
[0018] FIG. 6 is a schematic, side cross-sectional view of part of a conventional liquid crystal display device including an FPC.
[0019] FIG. 7 is a schematic, top plan view of the FPC of FIG. 6 when the FPC is laid out flat.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] Reference will now be made to the drawings to describe the preferred embodiments in detail.
[0021] Referring to FIG. 1 , an LCD 200 includes a liquid crystal display panel 21 , a backlight module 250 disposed adjacent to the liquid crystal display panel 21 , a frame 260 containing the backlight module 250 , a PCB 270 disposed adjacent to the frame 260 , an FPC 2 interconnecting the liquid crystal display panel 21 and the PCB 270 , and a driving IC 25 disposed on the FPC 2 .
[0022] Referring to FIG. 2 , the FPC 2 includes a substrate 20 , a plurality of electrically conductive input lines 210 having input patches 220 , a plurality of electrically conductive output lines 230 having output patches 240 , and a resin layer 26 . The substrate 20 includes a first joint part 22 for connecting to the PCB 270 , and a second joint part 24 for connecting to the liquid crystal display panel 21 . The input patches 220 are formed on the first joint part 22 . The output patches 240 are formed on the second joint part 24 .
[0023] Referring to FIG. 3 , the driving IC 25 is disposed in a middle region of the substrate 20 . Outer ends of the input lines 210 of the FPC 2 are connected to the PCB 270 . Inner ends of the input lines 210 are joined to a plurality of pins 251 of the driving IC 25 . Thus the input lines 210 provide signal transmission from the PCB 270 to the driving IC 25 . Outer ends of the output lines 230 of the FPC 2 are connected to the liquid crystal display panel 21 . Inner ends of the output lines 230 are joined to a plurality of pins 252 of the driving IC 25 . Thus the output lines 230 provide signal transmission from the driving IC 25 to the liquid crystal display panel 21 . The resin layer 26 covers portions of the input lines 210 and the output lines 230 around the driving IC 25 . The resin layer 26 can fix the driving IC 25 in place. An aligning mark 28 is formed beside the output patches 240 .
[0024] The input patches 220 and the output patches 240 are all shaped as isosceles triangles. In the illustrated embodiment, the input patches 220 and the output patches 240 all have the same size and shape. The input patches 220 are arranged generally in a row. Each input patch 220 has a point between the two sides of the triangle that are the same length. The points of every second input patch 220 in the row of input patches 220 face toward the outside of the substrate 20 . The points of every other input patch 220 in the row of input patches 220 face toward the driving IC 25 . That is, each two adjacent input patches 220 are oriented diametrically opposite each other. In other words, in general, a portion of one input patch 220 having a smaller width is opposite a portion of an adjacent input patch 220 having a larger width. Thus the row of input patches 220 comprises oppositely oriented input patches 220 arranged side by side in alternating fashion. The output patches 240 are arranged in a row, in essentially the same way that the input patches 220 are arranged.
[0025] Each input patch 220 has a base side opposite from the point. Each output patch 240 has a base side opposite from the point. A width of the base side of each input patch 220 is equal to a width of the base side of each output patch 240 . Distances between adjacent input patches 220 are the same. Distances between adjacent output patches 240 are the same.
[0026] The width of the base side of each input conductive pattern 220 is the same as the width of each input line 120 of the above-described conventional FPC 1 . Similarly, the width of the base side of each output patch 240 is the same as the width of each output line 140 of the FPC 1 . The distance between each two adjacent input patches 220 is similar to or somewhat less than the distance between each two adjacent input lines 120 of the FPC 1 . The distance between each two adjacent output patches 240 is similar to or somewhat less than the distance between each two adjacent output lines 140 of the FPC 1 . In general, a region that can contain only one input line 120 is able to contain two adjacent input patches 220 . In other words, assuming that a size of the FPC 2 is the same as a size of the FPC 1 , the amount of input lines 210 of the FPC 2 can be approximately twice the amount of input lines 120 of the FPC 1 . Similarly, the amount of output lines 230 of the FPC 2 can be approximately twice the amount of output lines 140 of the FPC 1 . Thus, the signal bandwidth of the FPC 2 can be approximately twice the signal bandwidth of the FPC 1 .
[0027] Referring to FIG. 4 , an FPC 3 of the second embodiment of the present invention is similar to the FPC 2 of the first embodiment. However, the FPC 3 includes a plurality of electrically conductive input lines having input patches 320 , and a plurality of electrically conductive output lines having output patches 340 . The input patches 320 and the output patches 340 are all shaped as diamonds. In the illustrated embodiment, the input patches 320 and the output patches 340 all have the same size and shape. The input patches 320 are arranged generally in two rows. Each input patch 320 in each row is located generally midway between two nearest input patches 320 in the other row. Thus the two rows of input patches 220 have the input patches 220 arranged in a staggered fashion. The output patches 340 are arranged generally in two rows, in essentially the same way that the input patches 220 are arranged.
[0028] A maximum transverse width of each input patch 320 is equal to a maximum transverse width of each output patch 340 . Distances between adjacent input patches 320 are the same. Distances between adjacent output patches 340 are the same.
[0029] The maximum transverse width of each input patch 320 is the same as the width of each input line 120 of the above-described conventional FPC 1 . Similarly, the maximum transverse width of each output patch 340 is the same as the width of each output line 140 of the FPC 1 . The distance between each two adjacent input patches 320 is similar to or somewhat less than the distance between each two adjacent input lines 120 of the FPC 1 . The distance between each two adjacent output patches 340 is similar to or somewhat less than the distance between each two adjacent output lines 140 of the FPC 1 . In general, a region that can contain only one input line 120 is able to contain two adjacent input patches 320 . In other words, assuming that a size of the FPC 3 is the same as the size of the FPC 1 , the amount of input lines of the FPC 3 can be approximately twice the amount of input lines 120 of the FPC 1 . Similarly, the amount of output lines of the FPC 3 can be approximately twice the amount of output lines 140 of the FPC 1 . Thus, the signal bandwidth of the FPC 3 can be approximately twice the signal bandwidth of the FPC 1 .
[0030] Referring to FIG. 5 , an FPC 4 of the third embodiment of the present invention is similar to the FPC 2 of the first embodiment. However, the FPC 4 includes a plurality of electrically conductive input lines having input patches 420 , and a plurality of electrically conductive output lines having output patches 440 . The input patches 420 and the output patches 440 are all shaped as right-angled triangles. The input patches 420 are arranged generally in a row. Each input patch 420 has a point that is distalmost from the right angle. The points of every second input patch 420 in the row of input patches 420 face toward the outside of a substrate (not labeled) of the FPC 4 . The points of every other input patch 420 in the row of input patches 420 face toward a central driving IC (not labeled). That is, each two adjacent input patches 420 are oriented diametrically opposite each other. In other words, in general, a portion of one input patch 420 having a smaller width is opposite a portion of an adjacent input patch 420 having a larger width. Thus the row of input patches 420 comprises oppositely oriented input patches 420 arranged side by side in alternating fashion. The output patches 440 are arranged in a row, in essentially the same way that the input patches 420 are arranged.
[0031] Each input patch 420 has a base side opposite from the point. Each output patch 440 has a base side opposite from the point. A width of the base side of each input patch 420 is equal to a width of the base side of each output patch 440 . Distances between adjacent input patches 420 are the same. Distances between adjacent output patches 440 are the same.
[0032] The width of the base side of each input patch 420 is the same as the width of each input line 120 of the above-described conventional FPC 1 . Similarly, the width of the base side of each output patch 440 is the same as the width of each output line 140 of the FPC 1 . The distance between each two adjacent input patches 420 is similar to or somewhat less than the distance between each two adjacent input lines 120 of the FPC 1 . The distance between each two adjacent output patches 440 is similar to or somewhat less than the distance between each two adjacent output lines 140 of the FPC 1 . In general, a region that can contain only one input line 120 is able to contain two adjacent input patches 420 . In other words, assuming that a size of the FPC 4 is the same as the size of the FPC 1 , the amount of input lines of the FPC 4 can be approximately twice the amount of input lines 120 of the FPC 1 . Similarly, the amount of output lines of the FPC 4 can be approximately twice the amount of output lines 140 of the FPC 1 . Thus, the signal bandwidth of the FPC 4 can be approximately twice the signal bandwidth of the FPC 1 .
[0033] It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
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An exemplary liquid crystal display device ( 200 ) includes a liquid crystal display panel ( 21 ), and a flexible printed circuit ( 2 ) joined to the liquid crystal display panel. The flexible printed circuit includes a substrate ( 20 ). The substrate includes a plurality of first conductive lines ( 210 ) and second conductive lines ( 230 ). The first conductive lines include a plurality of first patches ( 220 ). The second conductive lines include a plurality of second patches ( 240 ). The first patches are arranged side by side oppositely oriented relative to each other in alternating fashion. The second patches are arranged side by side oppositely oriented relative to each other in alternating fashion.
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BACKGROUND OF THE INVENTION
This invention relates to a multi-purpose presence grooming implement and, in particular, to a presence grooming implement which is the combination of a hair dryer and an electric razor (or a lint eater) utilizing a common power supply.
It is known that hair dryer, razor and lint eater etc. are all necessary implements for presence grooming work of gentlemen. However, since conventional hair dryer, electric razor and lint eater are all single-purpose implements, several different implements must be used for different presence grooming work, which makes the presence grooming work very inconvenient. In particular, during travelling, the above-described implements necessary for a complete presence grooming job will inevitably occupy considerable space in the trunk and thus greatly reduce available space for other articles. Consequently, the necessity of a more handy, compact multi-purpose presence grooming implement is imminent.
SUMMARY OF THE INVENTION
In view of the afore-mentioned drawbacks suffered by conventional presence grooming implements, the primary object of this invention is to provide a multi-purpose presence grooming implement which possesses both the functions of a hair dryer, and an electric razor (or even a lint eater).
In accordance with a first preferred embodiment of this invention, an eletric razor or a lint eater is electrically and mechanically connected to the handle of a hair dryer in a detachable manner to form an integrated implement applicable both as a hair dryer and an electric razor (or a lint eater).
In accordance with a second embodiment of this invention, an electric razor or a lint eater is electrically and mechanically connected to a portion of a hair dryer opposite to the barrel of the latter in a detachable manner to form an integrated implement applicable both as a hair dryer and an electric razor (or a lint eater ).
BRIEF DESCRIPTION OF THE DRAWINGS
This invention will be more fully understood with reference to the following detailed description and accompanying drawings.
FIG. 1 is a schematic longitudinal sectional view of a presence grooming implement in accordance with the first embodiment of this invention;
FIG. 2 is an electrical schematic diagram for the implement as shown in FIG. 1;
FIG. 3 is a cross-sectional view of another type of fastening mechanism for combining an electric razor to a hair dryer so as to form an integrated implement of this invention; and
FIG. 4 schematically shows the arrangement of a presence grooming implement in accordance with a second embodiment of this invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The construction of the implement according to the first embodiment of this invention will now be described referring to FIGS. 1 and 2. In this embodiment, the presence grooming implement mainly comprises a hair dryer 20, an electric razor 30 and a fastening mechanism 40 for fastening the hair dryer 20 and the electric razor 30 together. The hair dryer 20 comprises a fan 70, a motor M1 for driving the fan 70, a heater R for generating heat energy, and a three-step switch S1 which can be optionally set at an OFF, COLD WIND or HOT WIND position so as to control the function of the hair dryer 20 by three optional states, namely (both the fan 70 and the heater R--OFF ), (only the fan 70--ON) and (both the fan 70 and the heater R--ON). Hence, the structure of the hair dryer 20 is substantially the same as a conventional one except that the two power supply wires as commonly used in a conventional hair dryer have been substituted by a first pair of electric conductors 61 and 62. The electric razor 30 comprises a set of cutters 80, a motor M2 for driving the set of cutters 80, and a switch S2 for controlling the rotation of the cutters 80. Consequently, the structure of the electric razor 30 is generally the same as a conventional one except that its power supply wires 1 and 2 diverge before being connected to the switch S2 and the motor M2, respectively, with one branch of each of wires 1 and 2 being, respectively, connected to a second pair of conductors 51 and 52 fixed to a operating plate 33 which is provided within the casing 31 of the razor 30 and partially extends outward of same casing 31. The second pair of conductors 51 and 52 are retracted to the interior of the casing 31 of the razor 30, as shown in FIG. 1. So, when the hair dryer 20 is not in use, they can be pushed out toward the hair dryer 20 through the operation of the operating plate 33, and when the hair dryer 20 is to be used, be contacted with the afore-mentioned first pair of conductors 61 and 62 provided within the hair dryer 20. The second pair of conductors 51 and 52, when being in contact with the first pair of conductors 61 and 62, are prevented from retracting backward by a locking means, which is per se known, unless they are moved back through operation to the operating plate 33. The hair dryer 20 and the electric razor 30 are detachably combined together by a fastening mechanism 40. The fastening mechanism 40 mainly comprises several engaging pawls 41 (only two engaging pawls 41 are shown in FIG. 1), several biasing springs 42 and an engaging groove 32 for being engaged by the engaging pawls 41. As shown in FIG. 1, each engaging pawl 41 is pivotably secured to the lower end of the hair dryer casing 21 at a pivot point 43 and is biased by a biasing spring 42 so as to inwardly force a hook portion 44 formed at the lower end of the engaging pawl 41. The engaging groove 32 is formed in the upper end of the electric razor casing 31. When the hair dryer 20 and the electric razor 30 are to be combined together, they are moved toward each other so as to force the hook portion 44 of each engaging pawl 41 to engage into the engaging groove 32 and remain there under the action of the biasing spring 42. On the contrary, when each engaging pawl 41 is depressed inwardly at the portion above the pivot point 43, the hook portion 44 at the lower end of the engaging pawls 41 will disengage from the engaging groove 32 and thus the electric razor 30 can be easily detached from the hair dryer 20. When the hair dryer 20 and the electric razor 30 are combined together in the manner as described above, the first pair of conductors 61 and 62 within the hair dryer 20 will, respectively, urge against the second pair of conductors 51 and 52 within the electric razor 30 under the action of a pair of springs 63 and 64 and thus power can be supplied to the motor M1 through the wires 1 and 2.
FIG. 2 is an electric schematic diagram for the implement as shown in FIG. 1. The power wire 1 is diverged into two branch wires 3 and 4 before being connected to the conductor 51. The wire 3 is connected to the conductor 51, while the wire 4 is connected to the motor M2 through the switch S2. The power wire 2 is diverged into two branch wires 10 and 11 before being connected to the conductor 52. The wire 10 is connected to the conductor 52, and the wire 11 to the motor M2. The contact between the conductor 51 and 61 and that between the conductor 52 and 62 occur at the same time due to the fact that both the conductors 51 and 52 are operated by the operating plate 33 in the same manner as described above. Namely, the switches S3 and S4 formed, respectively, by the conductor pairs 51, 61 and 52, 62 are opened or closed at the same time. The connection between the conductors 61 and 62 is as shown in FIG. 2. Namely, the the motor M1 is connected in parallel to the heater R through a three-step switch S1. When the connecting piece 6 in the switch S1 is connected neither to terminal A nor to terminal B, the switch S1 is in a OFF position. When it is connected either to only terminal A or to both terminals A and B, the switch S1 is, respectively, in a COLD WIND or HOT WIND position as described above.
FIG. 3 shows another alternative fastening mechanism, in cross section, for combining the hair dryer and the electric razor. In this case, two insulators 67 and 68 are, respectively, encompassed around the two conductors 65 and 66 provided within the hair dryer casing 21, and a magnet 69 is filled in the space between the casing 21 and the insulators 67, 68 at the juncture of the hair dryer and the electric razor. Similar structure is provided on the side of the electric razor 30. Thus, the hair dryer 20 and the electric razor 30 can be detachably combined together by means of magnetic force instead of by the engaging mechanism 40 as shown in FIG. 1.
When the implement shown in FIGS. 1 through 3 is to be used as a hair dryer, the operation is exactly the same as a conventional single-purpose hair dryer except that the hair dryer part 20 and the the razor part 30 must be first combined together. On the other hand, when the same implement is to be used as an electric razor, its electric razor part 30 can be directly employed in a separate state (from the hair dryer part 20), or it can also be utilized in a combined (assembled) state with the switch S1 being set to the OFF position.
Although this invention has been described, in the above embodiment, with respect to the case that the electric razor 30 is detachably combined to the handle of the hair dryer 20, the invention is not limited to this combined state. For example, the electric razor part 30 can also be fastened to the opposite side of the barrel 22 of the hair dryer part 20 in a similar manner as shown in FIG. 4. Alternatively, the electric razor part 30 can be permanently combined to the hair dryer handle or to the opposite side of the hair dryer barrel 22. Namely, the hair dryer part 20 and the electrivc razor part 30 may have separate switches S1 and S2, yet have integrally formed common casing. Under this situation, two wires can be used instead of the two pairs of conductors 51, 61 and 52, 62. On the other hand, since the construction of an electric lint eater is substantially the same as that of an electric razor 30 except that the mesh for the perforations of the cover plate 23 (see FIG. 1) in the former case is somewhat larger than the latter case, the replacement of another cover plate suitable for an electric lint eater will enable the implement of this invention to be used also as an electric lint eater.
While this invention has been described in terms of two embodiments, it is to be understood that this invention need not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures.
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This invention discloses a presence grooming implement comprising a hair dryer and an electric razor (or a lint eater), wherein the electric razor (or lint eater) is electrically and mechanically connected to the handle of the hair dryer in a detachable or permanent manner to form a integrated implement which is applicable as a hair dryer, an electric razor and even a lint eater.
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FIELD OF THE INVENTION
[0001] The present application is directed to power amplifiers and more particularly to a circuit that protects power amplifiers from operating at excessive voltages that might cause damage to the power amplifier.
BACKGROUND OF THE INVENTION
[0002] Wireless transmitters typically comprise signal processing circuitry followed by a power amplifier that elevates the power of a signal to be transmitted prior to emission by an antenna. Such power amplifiers are becoming more common as a result of the ever increasing proliferation of mobile terminals that incorporate some form of wireless transmitter.
[0003] The term โmobile terminalโ encompasses pagers, cellular phones, personal digital assistants, laptops equipped with wireless modems, and the like. These mobile terminals are subject to numerous telecommunications standards and regulations which govern their behavior. Many of these standards govern the power levels with which the mobile terminals are allowed to transmit signals. This is done to prevent cross-channel interference in some cases, as well as help the mobile terminals conserve battery power. In many instances the power levels are controlled, either by a base station or by the mobile terminal at the instruction of the base station.
[0004] One side effect of this mobile environment is that the power amplifier of the transmitter has to withstand large voltage standing wave ratios (VSWR) at elevated supply voltages. GSM in particular may generate a VSWR of 15:1 at times. This can quickly lead to device burnout as voltage peaks during successive periods at collectors of the transistors forming the power amplifiers exceed tolerable voltage levels.
[0005] In addition to mobile terminals, wireless LANs of computing devices are also becoming more common. The computing devices include a wireless transmitter that likewise has a power amplifier that may be subject to extended voltage peaks and damage therefrom.
[0006] Thus, there remains a need for a way to protect power amplifiers in transmitters from voltage peaks during successive periods that exceed design parameters and may cause burnout in the power amplifier.
SUMMARY OF THE INVENTION
[0007] The present invention adds a feedback loop to a power amplifier. The power amplifier, in an exemplary embodiment, is part of a transmitter chain. The feedback loop comprises a sensing circuit and a processing circuit. When the sensing circuit senses that the output of the power amplifier is high enough that operation at that operating point for successive cycles or periods would damage the power amplifier, the sensing function causes the processing circuit to change the bias provided to the power amplifier in such a manner that the output power is lessened to an acceptable level.
[0008] In a first embodiment, the sensing circuit is formed from a transistor that acts as an avalanche diode. In a second embodiment, the sensing circuit is formed from a plurality of diodes. In a third embodiment, the sensing circuit is formed from a plurality of transistors. Common among these sensing circuits is that they remain off until the output of the power amplifier exceeds a predetermined threshold. Above the predetermined threshold, the current passing through the sensing circuit increases rapidly with small increases in applied voltage above the threshold.
[0009] The processing circuit may act on the bias circuit differently depending on different embodiments. In an exemplary embodiment, the processing circuit comprises a current mirror that sinks bias current from the input of the power amplifier, thereby reducing the output of the power amplifier. In a second exemplary embodiment, the current mirror turns off the bias current when the sensing circuit detects an output over the threshold. Alternative actions may take place depending on the nature of the bias circuit used.
[0010] Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0011] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention.
[0012] [0012]FIG. 1 illustrates a top level schematic diagram according to one embodiment of the present invention;
[0013] [0013]FIG. 2A illustrates a circuit level schematic diagram according to an exemplary embodiment of the present invention with a first bias circuit;
[0014] [0014]FIG. 2B illustrates a circuit level schematic diagram according to the embodiment of FIG. 2A with a second bias circuit;
[0015] [0015]FIG. 3 illustrates a circuit level schematic diagram according to a second exemplary embodiment of the present invention;
[0016] [0016]FIG. 4 illustrates a circuit level schematic diagram according to a third exemplary embodiment of the present invention; and
[0017] [0017]FIG. 5 illustrates a circuit level schematic diagram according to a fourth exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of practicing the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.
[0019] The present invention is designed to prevent burnout of power amplifiers. The most common implementation will be in wireless transmitters such as those used by mobile terminals or wireless modems; however, any power amplifier may be protected from burnout through the teachings of the present invention.
[0020] The present invention modifies a power amplifier into a power amplifier circuit 10 , such as illustrated schematically in FIG. 1. The power amplifier circuit 10 comprises a power amplifier (PA) 12 , a sensing circuit 14 , a processing circuit 16 , and a bias circuit 18 . The power amplifier 12 receives an RF IN signal, amplifies it, and produces an RF OUT signal. The power amplifier 12 also receives a bias signal from the bias circuit 18 . In some embodiments, the bias circuit 18 may be incorporated into the semiconductor having the power amplifier 12 , but need not be.
[0021] Given the current desire to minimize extra components, it is possible that the power amplifier 12 , the sensing circuit 14 , the processing circuit 16 , and the bias circuit 18 are all printed as a single monolithic integrated circuit, but again, need not be.
[0022] The power amplifier 12 may be a transistor cell array comparable to those illustrated in U.S. patent applications Ser. Nos. 09/878,461, filed Jun. 11, 2001; and 09/952,524, filed Sep. 14, 2001; and U.S. Pat. Nos. 6,265,943; 5,608,353, and 5,629,648, which are all hereby incorporated by reference. Alternatively, the power amplifier 12 may be a single transistor, and will be represented as such in the subsequent Figures. It is to be understood, however, that despite its representation as a single transistor, the power amplifier 12 may in fact be a transistor array as described in the previously incorporated applications and patents or any other transistor amplifier configuration available to those skilled in the art.
[0023] The sensing circuit 14 is coupled to the RF OUT signal and detects whether the RF OUT signal has risen above a predetermined threshold. The predetermined threshold is, in an exemplary embodiment, set below a voltage at which extended operation would cause burnout of the power amplifier 12 . The sensing circuit 14 outputs a sensed signal to the processing circuit 16 when the predetermined threshold has been exceeded.
[0024] The processing circuit 16 receives the sensed signal from the sensing circuit 14 and modifies the bias point provided by the bias circuit 18 so as to reduce the bias provided to the power amplifier 12 . This causes the power amplifier 12 to have a lower output, thus reducing the chance of burnout. The precise details of the sensing circuit 14 and the processing circuit 16 depend on the embodiment and will be explored further below.
[0025] The bias circuit 18 may be of a number of different types as illustrated below. FIG. 2A illustrates a circuit level diagram of a first embodiment of the present invention with a first bias circuit 18 A. The RF IN signal is coupled to the power amplifier 12 by a capacitor 20 . The RF OUT signal is generated by the power amplifier 12 . In the embodiment shown, the collector of a transistor Q 1 , provides the RF OUT signal. A transistor Q 3 , particularly the base-emitter junction of the transistor Q 3 , is used as an avalanche diode to form the sensing circuit 14 . The base-emitter junction begins to pass current when the applied reverse voltage exceeds a predetermined threshold. In an exemplary embodiment, the predetermined threshold comprises approximately 8 V. The current rapidly increases from the microampere range to the milliampere range with a small increase in applied voltage above the conduction threshold.
[0026] A resistor R 3 controls the magnitude of the current produced by the transistor Q 3 . Resistors R 3 and R 4 , along with capacitor C 2 , form a low pass filter for filtering the current pulses produced by the transistor Q 3 . The filtered current is then applied to the current mirror 26 comprised of transistors Q 4 and Q 5 . The current flowing through Q 4 is mirrored across to the transistor Q 5 as a function of the respective sizes of the two transistors.
[0027] To create the mirrored current, the output of the current mirror 26 (transistor Q 5 ) sinks bias current from bias circuit 18 A to ground that was destined for the power amplifier 12 . In particular, as current flows through the transistor Q 5 , less current is presented to diode connected transistor Q 2 . Thus, less current passes through resistor R 1 for use by the power amplifier 12 . This reduces the bias on the power amplifier 12 when peak RF voltages start approaching the destruction limits of the power amplifier 12 .
[0028] Capacitor C 2 , along with resistors R 3 and R 4 , sets the loop response time. Resistor R 3 is determined by the need to limit current spikes through transistor Q 3 . The value of R 4 determines the rate at which current passes into the current mirror 26 . In an exemplary embodiment, the resistances of resistors R 3 and R 4 is 500 ฮฉ. The capacitor C 2 sets the loop time constant. In an exemplary embodiment, the capacitance of capacitor C 2 is 1000 pF for loop stability. Where processing circuit 16 is integrated into the monolithic chip that contains the sensing circuit 14 and the power amplifier 12 , it may be desirable to split the capacitor C 2 such that a portion of the capacitance of the capacitor is off the semiconductor.
[0029] It may be preferable to have a relatively long loop time constant. For example, if the loop time constant is short, an inductive pulse may be generated at the RF OUT port from the bias and/or matching network. This passes more current through the transistor Q 3 , causing a regenerative oscillation. A longer loop time constant reduces the rate of change in the collector current of the power amplifier 12 and increases stability.
[0030] A second bias circuit 18 B is illustrated in FIG. 2B. In this embodiment of the bias circuit 18 , as current increases in the transistor Q 5 , the transistor Q 6 turns off because no current flows in R 2 . As a result, the collector of the transistor Q 2 has little or no current, and the power amplifier 12 has no bias input. Thus, instead of shunting the current to ground, this embodiment significantly reduces or turns off the bias current entirely.
[0031] For further information about the bias circuit 18 B, reference is made to commonly owned U.S. patent application Ser. No. 09/467,415, filed Dec. 20, 1999, which is hereby incorporated by reference in its entirety. Bias circuit 18 B is sometimes referred to as a buffered passive bias network.
[0032] As would be appreciated, processing circuit 16 may be modified as needed to accommodate differing bias circuits 18 .
[0033] In an alternate embodiment, the sensing circuit 14 may be formed by a string of diodes 28 A- 28 E as illustrated in FIG. 3. The number of diodes 28 is determined by the desired threshold voltage above which the feedback loop should be operative. As with the previous embodiment, in this embodiment, this value may be approximately 8 volts.
[0034] [0034]FIG. 4 illustrates yet another alternate embodiment of the sensing circuit 14 . In this embodiment, the diodes 28 of FIG. 3 are replaced with diode connected transistors Q 7 -Q 9 . Again, the number of diode connected transistors is determined by the desired threshold voltage above which the feedback loop should be operative.
[0035] [0035]FIG. 5 illustrates still another embodiment of sensing circuit 14 . In this embodiment, the transistor Q 3 of FIG. 2A is replaced with a series of transistors that operate as diodes, much like in FIG. 4. However, a first transistor Q 10 cooperates with resistors 54 , 56 to form a base to emitter multiplier circuit as is well understood. The resistors 54 , 56 act to increase the current that is available when the transistor Q 10 does in fact turn on. Transistors Q 11 -Q 13 act to increase the threshold voltage of the sensing circuit 14 so normal operation does not actuate the feedback.
[0036] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.
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A power amplifier circuit comprises a sensing circuit and a processing circuit adapted to detect voltage peaks in an output of a power amplifier. If the voltage peak is above a predetermined threshold level, the processing circuit acts to reduce bias provided to the power amplifier, thereby reducing the output levels.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method for operating a braking device for a vehicle, in particular a motor vehicle, that includes at least one brake booster, an automatic brake boost being carried out as a function of a driver's braking command.
BACKGROUND INFORMATION
[0002] Methods of the type mentioned at the outset are known from the related art. For the operation of hydraulic braking devices, it is known, especially in the case of motor vehicles, to recognize an emergency situation as a function of a driver's braking command and to set a brake boost to assist the driver in the emergency situation. Thus, it is known, for example, from DE 10 2010 002 574 A1 to recognize an emergency braking situation as a function of the driver's braking command and a change of the rotational speed of at least one wheel of the vehicle. Modern braking devices operate hydraulically, the driver of the motor vehicle being able to set a desired braking pressure via brake pedal actuation. Typically, the hydraulic pressure set by the brake pedal actuation acts on a brake master cylinder, which presses brake fluid into a conduit system of the braking device, the thus-generated pressure being available to the wheel braking devices for the application of a braking torque. It is known to provide braking devices of this type with a pneumatic brake booster that makes available a higher braking pressure at the same operating force of the brake pedal. Typically, the braking force is boosted by a vacuum. The vacuum may be provided, for example, by the vacuum present in the intake manifold of an internal combustion engine of the motor vehicle or by a separate vacuum pump. A typical pneumatic brake booster includes a prechamber and a main chamber, the vacuum being applied to both. The two chambers are normally separated by a displaceable diaphragm. More or less atmospheric pressure comes into the prechamber by actuation of the brake pedal, thereby supporting the brake pedal actuation.
[0003] It is also known to provide a hydraulic brake booster that generates additional braking pressure and actively assists the conventional vacuum brake boost if the conventional vacuum-controlled brake booster is no longer sufficient to produce the needed or desired braking force or to reduce the structural volume of the pneumatic brake booster. Braking devices of this type are known in particular in connection with ESP systems (ESP=electronic stability program), which stabilize the driving state of a motor vehicle by individual wheel brake interventions.
[0004] According to the aforementioned document, the triggering instant for the hydraulic brake boost is hitherto selected as a function of the vehicle behavior, in particular as a function of the wheel speeds. As a result, the hydraulic brake boost usually occurs in a time-delayed manner.
SUMMARY
[0005] The method of the present invention has the advantage that an emergency situation is detected even faster than previously, thereby assisting the driver more quickly in his effort to decelerate the vehicle. This is achieved according to the present invention in that the driver's braking command is determined via a vacuum sensor assigned to a pneumatic brake booster and a hydraulic brake boost is set. The vacuum sensor makes it possible indirectly to infer the driver's command without provision of a pressure sensor as otherwise used in hydraulic operation. In particular, it is provided that a vacuum sensor already present in the system, which typically is used for engine control/regulation, is employed for the method according to the present invention, so that no additional costs for an additional sensor are incurred. If the driver's braking command is detected via the vacuum sensor, the hydraulic brake boost is able to be initiated even before the vehicle wheel speeds change. As a result, the driver receives especially quick assistance from the brake boost.
[0006] According to an advantageous further refinement of the present invention, it is provided that a pressure value detected by the vacuum sensor is compared to at least one specifiable first limiting value and that, if the first limiting value is exceeded by the pressure value, a first brake boost is set. The first brake boost is thus set only if the first specifiable limiting value has been exceeded. An inadvertent or premature triggering of the brake boost is thus prevented in a simple manner. The pressure value may be a pressure detected directly by the vacuum sensor or a quantity derived therefrom.
[0007] Furthermore, it is preferably provided that the pressure value detected by the vacuum sensor is compared to a second specifiable limiting value and that, in the event that the second limiting value is exceeded, a second brake boost is set, the second limiting value being higher than the first limiting value and the second brake boost being higher than the first brake boost. Therefore, when the pressure value detected by the vacuum sensor increases or when the pressure in the prechamber of the brake booster increases, the brake boost increases. Because this occurs as a function of the at least two limiting values, an incremental increase of the brake boost is provided in the present case.
[0008] Expediently, it is further preferably provided that the pressure value detected by the vacuum sensor is compared to a third specifiable limiting value, and, if the third limiting value is exceeded, a third brake boost is set, the third limiting value being higher than the second limiting value and the third brake boost being higher than the second brake boost. This essentially yields the aforementioned advantages. The provision of at least three limiting values makes it possible to increment the brake boost in a sufficiently satisfactory manner.
[0009] Furthermore, it is preferably provided that the brake boost is set as a function of the wear, service life and/or operating temperature of the braking device. If, for example, it is detected during operation of the braking device that signs of wear are present and as a result lower braking torques are produced while the control state remains unchanged, the brake boost is increased accordingly to compensate for the wear on the braking device. The brake boost is advantageously set as a function of wear, service life and/or operating temperature, regardless of which limiting value is being exceeded by the pressure currently detected by the vacuum sensor.
[0010] Furthermore, it is preferably provided that the brake boost is set as a function of a current road gradient. To accomplish this, the road gradient is continuously ascertained, for example, by an acceleration sensor and/or on the basis of data of a navigation system of the vehicle. If it is detected that the vehicle is moving up an incline, the brake boost is preferably reduced. If it is detected that the vehicle is moving down an incline, the brake boost is preferably increased. This results in the same vehicle braking behavior always being provided for the driver.
[0011] The control unit according to the present invention is distinguished by the fact that it carries out the method according to the present invention. The control unit is thus an especially preferably a component of the braking device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows an advantageous method for operating a braking device of a motor vehicle.
[0013] FIG. 2 shows a relationship between a brake booster prechamber pressure detected by a vacuum sensor and a brake master cylinder pressure.
DETAILED DESCRIPTION
[0014] FIG. 1 shows a diagram on the basis of which an advantageous method for operating a braking device of a vehicle is to be explained. For this purpose, FIG. 1 shows, plotted in a diagram over time t, a vehicle deceleration a x while a braking operation is being carried out, pressure p mc in a brake master cylinder of the braking device and braking pressure p h additionally set by a hydraulic brake boost.
[0015] It is assumed that at instant t 0 a brake pedal of the braking device is being operated by the driver of the vehicle. As a result, pressure p mc in the brake master cylinder increases in accordance with the brake pedal actuation up to an instant t 2 at which the brake pedal has reached its end position as set by the driver. The presently considered braking device includes a pneumatic brake booster that automatically increases the braking pressure beyond the braking pressure specified by the driver. This produces a vehicle deceleration ax 1 .
[0016] Additional pressure p h that is set by the hydraulic brake booster is displayed in the lower section of FIG. 1 . The vehicle deceleration is normally used as the trigger criterion. For this purpose the current vehicle deceleration is compared, for example, to a limiting value and, when the limiting value is reached, the hydraulic brake booster additionally sets the additional braking pressure, as shown in FIG. 1 , so that vehicle deceleration ax 2 (solid line) results. The additional brake boost by the hydraulic brake booster occurs only starting at instant t 2 .
[0017] In the present case, a vacuum sensor is used to monitor a vacuum acting on the pneumatic brake booster. The vacuum here is provided, for example, by the intake port of an internal combustion engine of the motor vehicle or by a separate vacuum pump that acts correspondingly on the pneumatic brake booster.
[0018] FIG. 2 shows the relationship between vacuum p v of the pneumatic brake booster and pressure p mc of the brake master cylinder. To this end, the two pressures p v and p m are plotted over time t. At an instant t a , if the brake pedal is being operated, pressure p v detected by the vacuum sensor increases. Pressure p mc in the brake master cylinder likewise increases. If the brake pedal is located in its end position, vacuum pressure p v detected by the vacuum sensor slowly decreases again within a time period t b , while the pressure in the brake master cylinder stays the same. If the driver terminates the braking operation by, for example, removing his foot from the brake pedal at an instant t c , the detected vacuum pressure increases to a maximum value, while the pressure in the brake master cylinder decreases again.
[0019] In the present case, it is now provided that the hydraulic brake boost is set or triggered based on pressure p v detected by the vacuum sensor. As is evident from FIG. 2 , a change in the pressure detected by the vacuum sensor takes place nearly simultaneously with the brake pedal actuation. Accordingly, an especially early signal is available for triggering the hydraulic brake boost. Because the provision of vacuum sensors, especially for engine regulation, is already known in many motor vehicles, the provision of an additional sensor, it is possible in particular to eliminate the provision of a pressure sensor in the hydraulic circuit of the braking device. Pressure p v detected by the vacuum sensor is compared here to three different limiting values. When pressure value p v increases and exceeds the particular limiting value, a higher brake boost is set by the hydraulic brake booster.
[0020] The described approach now makes it possible to set the hydraulic brake boost much earlier than previously, namely already at instant t 21 . Thus, FIG. 1 shows as a dashed line additional braking pressure p h * provided by the hydraulic brake boost and vehicle deceleration ax 2 * for the previously described case in which the hydraulic brake boost is set as a function of the pressure detected by the vacuum sensor. Thus, it is obvious that the brake boost is set or settable as a function of the pressure value not only earlier, namely at time t 1 , but also with greater assistance, that is, with a higher additional braking pressure p h *. This results in earlier and sharper deceleration ax 2 * of the motor vehicle.
[0021] The brake boost is preferably terminated in a ramp-like manner as shown in FIG. 1 , the boost and the negative slope of the ramp preferably decreasing incrementally over time. The ramp-like reduction of the brake boost contributes in particular to driving comfort and is also a function of the residual vehicle speed. Preferably, a current road gradient and/or wear of the braking device are/is taken into account in the setting of brake boost p h * and compensated by the setting of hydraulic brake boost p h *. As an alternative to the provision of three fixed specifiable limiting values for the setting of the hydraulic brake boost, it is also conceivable to set a continuous brake boost as a function of the current pressure value of vacuum sensor p v .
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A method is described for operating a hydraulic braking device of a vehicle, in particular a motor vehicle, including at least one brake booster, which sets a brake boost as a function of a driver's braking command. It is provided that the driver's braking command is ascertained via a vacuum sensor assigned to a pneumatic brake booster and a hydraulic brake boost is set.
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BACKGROUND
[0001] 1. Field
[0002] The present disclosure relates to lifting mechanisms for use with oilfield machines. More particularly, the present disclosure relates to lifting apparatus and methods for using the same in conjunction with oilfield shaking separators.
[0003] 2. Background Art
[0004] Rotary drilling methods employing a drill bit and drill stems have long been used to drill wellbores in subterranean formations. Drilling fluids or muds are commonly circulated in the well during such drilling to cool and lubricate the drilling apparatus, lift drilling cuttings out of the wellbore, and counterbalance the subterranean formation pressure encountered. The recirculation of the drilling mud requires the fast and efficient removal of the drilling cuttings and other entrained solids from the drilling mud prior to reuse. Shaker separators are commonly used to remove the bulk solids from the drilling mud.
[0005] A shaker separator consists of an elongated, box-like, rigid bed and a screen attached to, and extending across, the bed. The bed is vibrated as the material to be separated is introduced to the screen which moves the relatively large size material along the screen and off the end of the bed. The liquid and/or relatively small sized material is passed into a pan. The bed can be vibrated by pneumatic, hydraulic, or rotary vibrators, in a conventional manner.
[0006] Various solids are brought up from the wellbore with the mud, including drill cuttings, clay, and debris. Sometimes clay that is directed into the shaker separator with the drilling fluid is sticky and heavy. Such solids risk causing screen breakage because they stick to the screen and are not transported to the discharge end of the shaker in an efficient manner. In such cases, it is desirable to lower the discharge end of the shaker bed to assist in the removal of the sticky solids from the screen.
[0007] At other times, coarse solids are easily conveyed along the top of the screen by the vibratory motion of the shaker. In order to preserve the drilling mud and increase the volume flow rate of the mud being directed into the separator, it is desirable to raise the discharge end of the shaker bed. When the discharge end is raised, the mud flow rate may be maximized while mud loss over the screen is minimized.
[0008] Some shaker separators have been built with systems to elevate the discharge end of the shaker bed. Many of these systems have employed manual operation techniques, such as hand wheels or jacks, to raise and lower the end of the bed. Other systems have included hydraulic lifts that are independently actuated, often requiring time and finesse by the operator to laterally level the discharge end of the shaker bed. Further, these systems have also included solenoids, which may be undesirable in the hazardous locations in which shaker separators are often used, particularly when separating drill cuttings from drilling mud. Thus, there is a need for a system to raise the discharge end of the shaker bed quickly and safely while keeping it level from side to side.
SUMMARY
[0009] In one aspect, the present disclosure relates to an apparatus to lift an oilfield machine including at least one lifting bellows, an alignment assembly extending between at least one lifting bellows and an adapter plate of the oilfield machine, the alignment assembly comprising an inner cylinder to reciprocate within a sleeve of the oilfield machine, and the alignment assembly comprising a top plate at an upper end of the inner cylinder, the top plate configured to transfer forces from the at least one lifting bellows and the inner cylinder to the adapter plate, wherein the sleeve is configured to restrict the inner cylinder to a substantially linear displacements therethrough.
[0010] In another aspect, the present disclosure relates to a method to lift an oilfield machine including positioning at least one lifting bellows beneath a component of the oilfield machine to be raised, positioning an alignment assembly between the at least one lifting bellows and an adapter plate of the component, wherein the alignment assembly comprises an inner cylinder and a top plate, wherein the inner cylinder is configured to reciprocate within a sleeve of the oilfield machine, inflating the lifting bellows beneath to raise the component with the inner cylinder, and restricting the inner cylinder to a substantially linear displacements with the sleeve.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a perspective view of a shaker assembly.
[0012] FIG. 2 is a perspective view of an embodiment of a shaker lift system.
[0013] FIG. 3 is a perspective view of a lift control assembly for the shaker lift system.
[0014] FIG. 4 is a piping and instrumentation diagram of an embodiment of the shaker lift system.
[0015] FIG. 5 is a perspective view of a control panel.
[0016] FIG. 6 is a perspective view of an angle indicator.
[0017] FIG. 7 is a piping and instrumentation diagram of an embodiment of the shaker lift system.
[0018] FIG. 8 is a perspective view of an alternative lifting mechanism in accordance with embodiments of the present disclosure.
[0019] FIG. 9 is a cross-sectional view of the alternative lifting mechanism of FIG. 8 .
DETAILED DESCRIPTION
[0020] Referring initially to FIG. 1 , the reference numeral 10 refers, in general, to a vibrating screen separator assembly that includes a frame, or bed 12 , that includes a bottom wall 14 having an opening (not shown), a pair of side walls 18 and 20 , and a cross support member 24 coupled between the walls 18 , 20 . Actuator 34 and 36 , respectively for imparting motion to the bed 12 are also coupled to the support member 24 .
[0021] A flow box 16 is located at a feed end 22 of the shaker bed 12 to direct solid-bearing drilling mud to the screens 26 , located therein. A slide 28 may be located at the discharge end 30 of the shaker bed 12 to direct separated solids to a collection area (not shown). The shaker 10 may be mounted to a skid 32 to facilitate transport of the shaker 10 to the drill site as well as to aid in the positioning and relocation of the shaker 10 within the drill site.
[0022] Referring to FIG. 2 , the lift system 40 includes a lift control assembly 42 , a hydraulic tank 44 , a first bellow 46 , and a second bellow 48 . The first and second bellows 46 , 48 are located near opposing corners 50 , 52 of the discharge end 30 of the shaker bed 12 (shown in FIG. 1 ). A shroud 54 is mounted to each of the first and second bellows 46 , 48 to help protect them from damage. An adapter plate 56 mounted to each shroud 54 attaches to an adjacent side wall 18 , 20 near the discharge end 30 of the shaker separator 10 .
[0023] In one embodiment, shown in FIG. 2 , the lift control assembly 42 is located at the discharge end 30 of the shaker bed 12 and the hydraulic tank 44 is shown to be at the feed end 22 of the shaker bed 12 . However the location of the lift control assembly 42 and the hydraulic tank 44 may be varied such that the lift control assembly 42 is located anywhere along the perimeter of the shaker assembly 10 where it is reachable by an operator and the hydraulic tank 44 is located in such proximity to first and second bellows 46 and 48 that fluid communication may reasonably be maintained between the hydraulic tank 44 and the bellows 46 , 48 .
[0024] The lift control assembly 42 is operable to control pressurized air to and from the hydraulic tank 44 as well as to control communication of fluid between the hydraulic tank 44 and each of the bellows 46 , 48 . As will be described, the lifting system 40 utilizes an air over fluid hydraulic system to raise and lower the discharge end 30 of the shaker bed 12 , thereby providing a range of incline to the bed 12 of the shaker separator 10 .
[0025] The hydraulic tank 44 is provided with a predetermined amount of liquid. In one embodiment, the liquid is water, such as when the shaker separator 10 is to be operated in temperatures where the water will not freeze. In one embodiment, the liquid is a fluid having an hydraulic fluid having a freezing point low enough for use in cold climates. A pneumatic line 72 directs air into the hydraulic tank 44 from the lift control assembly 42 . A first hydraulic line 80 directs the liquid to the bellows 46 , 48 . The flow through the first hydraulic line 80 is controlled by the lift control assembly 42 . Thus, there is not a continuously open flow line between the hydraulic tank 44 and the bellows 46 , 48 .
[0026] Referring to FIGS. 3 and 4 , the lift control assembly 42 includes an air inlet 62 into which pressurized air is fed. The pressurized air is provided to a first valve 64 via a first pneumatic line 66 and to a second valve 68 via a first pilot line 70 . The first valve 64 is connected to a second pneumatic line 72 leading to the hydraulic tank 44 . A third valve 74 has an actuator 76 that is connected via a second pilot line 78 to the second valve 68 . The third valve 74 opens and closes a pathway between a first hydraulic line 80 from the hydraulic tank 44 and a hydraulic junction 82 providing liquid to second and third hydraulic lines 84 , 86 leading to the first and second bellows 46 , 48 . The lift control assembly 42 is discussed in further detail below.
[0027] Fluid to the first bellow 46 is provided through second hydraulic line 84 while fluid to the second bellow 48 is provided through third hydraulic line 86 . The second and third hydraulic lines 84 , 86 are connected to the hydraulic junction 82 in parallel such that, when the third valve 74 is open, liquid is communicated to the first and second bellows 46 , 48 simultaneously. Further, when the third valve 74 is closed, the liquid may be communicated between the first bellow 46 and the second bellow 48 via the second and third hydraulic lines 84 , 86 .
[0028] Continuing to refer to FIGS. 2-4 , air from a pressurized air supply 88 enters the lift control system 40 through the air inlet 62 . A pressure regulator 90 is preferably included at the inlet 62 to provide an air stream at a predetermined pressure to the system. The preferred pressure will depend upon the weight to be lifted and the physical properties of the liquid to be communicated between the hydraulic tank 44 and the first and second bellows 46 , 48 at within the anticipated ambient operating conditions. A pressure gauge 92 is preferably included along the second pneumatic line 72 between the first valve 64 and the hydraulic tank 44 to use in the adjustment of the pressure regulator 90 .
[0029] Air from the pressure regulator 90 is provided to the first valve 64 through the first pneumatic line 66 and to the second valve 68 through the first pilot line 70 . The first valve 64 can be toggled between two positions, corresponding to raising and lowering the discharge end 30 of the shaker bed 12 . Further, the first valve 64 is a three-way valve, that is there are three ports into or out of which air may be directed. In a first position, corresponding to the operation of raising the discharge end 30 , the pressurized air from the regulator 90 enters one port of the first valve 64 and exits a second port of the first valve 64 , which port directs the air to the second pneumatic line 72 and the hydraulic tank 44 . In a second position of the first valve 64 , corresponding to the operation of lowering the discharge end 30 , air, displaced by fluid forced back into the hydraulic tank 44 , is forced from the hydraulic tank 44 through the second pneumatic line 72 to the first valve 64 is vented through a third port of the first valve 64 . In one embodiment, the first valve 64 is a three-way, two position ball valve.
[0030] In one embodiment, the second valve 68 is biased to a closed position such that the pressurized air from the first pilot line 70 is not directed to the second pilot line 78 unless the second valve 68 is manually actuated. While in the normally closed position, the second valve 68 provides a vent for air in the second pilot line 78 . Upon actuation of the second valve 68 , the pressurized air from the first pilot line 70 is directed to the second pilot line 78 . Air directed through the second pilot line 78 provides communication to the actuator of the third valve 74 , thereby actuating the third valve 74 when the second valve 68 is actuated. In one embodiment, the second valve 68 is a signal valve.
[0031] The third valve 74 is biased to a closed position thereby preventing communication of liquid through the first hydraulic line 80 to the hydraulic junction 82 . As previously explained, when the third valve 74 is actuated, fluid flow between the hydraulic tank 44 and the first and second bellows 46 , 48 is open. In one embodiment, the third valve 74 is a two-way ball valve.
[0032] Referring to FIGS. 2 , 3 , and 6 , to operate the lifting system 40 , an operator will position the first valve 64 in a desired position corresponding to whether the shaker discharge end 30 will be raised or lowered. To lift the discharge end 30 of the shaker separator 10 , the operator will place the first valve 64 in a corresponding position using a handle, knob, or other such operator interface. Air from the air supply 88 as regulated by the pressure regulator 90 is directed through the first valve 64 to the hydraulic tank 44 . So long as the third valve 74 is closed, communication of fluid from the hydraulic tank 44 to the first and second bellows 46 , 48 is prevented and the shaker 10 will maintain its initial incline.
[0033] To raise or lower the discharge end 30 , the operator actuates the second valve 68 thereby providing pressurized air to the actuator 76 of the third valve 74 . Actuation of the third valve 74 opens the passage between the first hydraulic line 80 and the hydraulic junction 82 . The pressurized air fed into the hydraulic tank 44 as a result of positioning the first valve 64 in the desired position, forces the liquid in the tank 44 through the first hydraulic line 80 to the hydraulic junction 82 . From the hydraulic junction 82 , the fluid is directed through the second and third hydraulic lines 84 , 86 to the first and second bellows 46 , 48 respectively. As the fluid fills the first and second bellows 46 , 48 , each bellow 46 , 48 expands to raise the discharge end 30 of the shaker separator 10 .
[0034] Once the desired incline of the bed 12 is achieved, the operator releases the second valve 68 , thereby closing it and releasing the actuator 76 of the third valve 74 . When the actuator 76 is released, the third valve 74 returns to a closed position. Thus, the fluid transferred to the first and second bellows 46 , 48 and the second and third hydraulic lines 84 , 86 is confined. If the first bellow 46 contains more fluid than the second bellow 48 or vice versa, the weight of the shaker separator 10 will force the fluid to equalize between the first bellow 46 and the second bellow 48 , thereby leveling the discharge end 30 from side to side.
[0035] To lower the discharge end 30 of the shaker separator 10 , an operator places the first valve 64 to a second position corresponding to lowering the discharge end 30 , again using a handle, knob, or other such interface device. When the first valve 64 is placed into the second position, any air under pressure in the second pneumatic line 72 and the hydraulic tank 44 may be vented. So long as the third valve 74 remains closed, only a minimal amount of air will be vented and the discharge end 30 will remain in the raised position.
[0036] The operator actuates the second valve 68 to open fluid communication from the air supply 88 to the actuator 76 of the third valve 74 . When the air through the second pilot line 78 actuates the third valve 74 , the third valve 74 opens to provide fluid communication of the liquid between the first and second bellows 46 , 48 and the hydraulic tank 44 . With pressure on the fluid released, the fluid moves back into the hydraulic tank 44 while the third valve 74 is open. The weight of the shaker separator 10 on the first and second bellows 46 , 48 forces the liquid back into the hydraulic tank 44 . Air from the hydraulic tank 44 , displaced by the liquid, is forced back through the second pneumatic line 72 and vented through the first valve 64 .
[0037] When the bed 12 of the shaker separator 10 has reached the desired declination angle, the operator releases the second valve 68 to stop the flow of liquid from the first and second bellows 46 , 48 to the hydraulic tank 44 . This again confines the fluid in the first and second bellows 46 , 48 and the second and third hydraulic lines 84 , 86 and freezes the discharge end 30 in the desired position.
[0038] Referring to FIGS. 1 , 2 , and 6 , to assist the operator in adjusting the discharge end 30 of the shaker separator 10 , a means for indicating a position of the discharge end 60 may be coupled between the shaker bed 12 and the floor or skid on which the shaker 10 is located. Indicator plates 94 may be located adjacent to one or both of the bellows 46 , 48 . The indicator plates 94 may include graduation lines corresponding desired positions of the discharge end 30 . Graduation lines may correspond to a height of the discharge end 30 above the skid or the floor. Graduation lines may correspond to an angle of the shaker bed 12 with respect to the skid or the floor. A marker 96 , or pointer, such as piece of formed sheet metal coupled to the bed 12 of the shaker separator 10 may be used to mark the angle of incline of the discharge end 30 of the shaker separator 10 relative to the skid 32 or floor to which the shaker separator 10 is mounted.
[0039] Referring to FIG. 2 , a track system 98 may be provided to guide the vertical movement of each of the first and second bellows 46 , 48 . The track system 98 includes upright plates 100 , 102 located on opposing sides of each bellow 46 , 48 . The inner upright plate 100 for the first bellow 46 is shown in FIG. 2 , while the corresponding outer upright plate 102 may be seen in FIG. 1 . Each upright plate 100 , 102 has a vertical track 104 along its inner surface 106 . Each shroud 54 is provided with rollers 108 , which roll along the track 104 . A wall 110 extending from each upright plate 100 , 102 helps keep the rollers 108 in a confined area near the track 104 .
[0040] One of skill in the art will appreciate that some variation of the components described are possible. For example the first and second bellows 46 , 48 may be replaced with other types of hydraulic lifters. Another variation includes replacing the first and second bellows 46 , 48 with a single lifter centrally located along the discharge end 30 of the shaker bed 12 .
[0041] In one embodiment of the lifting system 40 โฒ, depicted in FIG. 7 , the lift control assembly 42 โฒ includes a tank control valve 64 โฒ, a pair of pilot control valves 68 โฒ, 68 โณ, a shuttle valve 112 , and a skinner fluid valve 74 โฒ. The pilot control valves 68 โฒ, 68 โณ and the skinner fluid valve 74 โฒ are biased to a closed position. Air from an air supply (not shown) is split, with a first stream directed through a pressure regulator 90 to the tank control valve 64 โฒ and a second stream split again into a first sub-stream and a second sub-stream. The first sub-stream is directed to the first pilot control valve 68 โฒ and the second sub-stream is directed to the second pilot control valve 68 โณ.
[0042] A pneumatic line 72 connects the tank control valve 64 โฒ to the hydraulic tank 44 . A first pilot line 70 โฒ connects the first pilot valve 68 โฒ to the shuttle valve 112 and a second pilot line 70 โณ connects the second pilot valve 68 โณ to the shuttle valve 112 . A third pilot line 78 โฒ connects the shuttle valve 112 to an actuator 76 โฒ on the skinner fluid valve 74 โฒ. A first hydraulic line 80 โฒ connects the hydraulic tank 44 to the skinner fluid valve 74 โฒ. A second hydraulic line 114 splits into two sub-hydraulic lines 84 โฒ, 86 โฒ going to each of the bellows 46 , 48 , which are coupled to the shaker separator 10 near the discharge end 30 .
[0043] To raise the discharge end 30 of the shaker separator 10 , an operator actuates the first pilot valve 68 โฒ. Air flows through the first pilot valve 68 โฒ to the shuttle valve 112 and to a pilot port of the tank control valve 64 โฒ. The shuttle valve 112 directs the air to the third pilot line 78 โฒ and actuates the skinner fluid valve 74 โฒ. Actuation of the skinner fluid valve 74 โฒ opens fluid communication between the hydraulic tank 44 and the bellows 46 , 48 through the first hydraulic line 80 โฒ and the second hydraulic line 114 . The air flow to the pilot port of the tank control valve 64 โฒ actuates the tank control valve 64 โฒ to provide pressure regulated air to the hydraulic tank 44 .
[0044] The pressure regulated air displaces fluid in the hydraulic tank 44 , causing the fluid to exit the tank 44 through the first hydraulic line 80 โฒ. The fluid is forced from the tank 44 through the skinner fluid valve 74 โฒ into the bellows 46 , 48 , causing them to expand and raise the discharge end 30 of the shaker separator 10 . When the first pilot valve 68 โฒ is released by the operator, air pressure through the first pilot line 70 โฒ to the shuttle valve 112 and air pressure to the pilot port of the tank control valve 64 โฒ drops. The drop in air pressure on the shuttle valve 112 releases the actuation of the skinner fluid valve 74 โฒ, returning it to its normally closed position and terminating fluid communication between the hydraulic tank 44 and the bellows 46 , 48 . The drop in air pressure to the tank control valve 64 โฒ releases it to its normal position wherein air in the hydraulic tank 44 and the pneumatic line 72 is vented and air flow into the hydraulic tank 44 from the air supply is stopped.
[0045] To lower the discharge end 30 of the shaker separator 10 , the operator actuates the second pilot valve 68 โณ. When the second pilot valve 68 โณ is actuated, air is directed to the shuttle valve 112 . The pilot signal to the shuttle valve 112 causes it to open and provide air flow to the third pilot line 78 โฒ, thereby actuating the skinner fluid valve 74 โฒ. Upon actuation of the skinner fluid valve 74 โฒ, the first and second hydraulic lines 80 โฒ, 114 are in fluid communication, providing fluid communication between the bellows 80 โฒ, 114 and the hydraulic tank 44 . The tank control valve 64 โฒ remains in its biased position wherein air from the hydraulic tank 44 is vented therethrough.
[0046] The bellows 46 , 48 are compressed by the weight of the shaker separator 10 causing the fluid therein to flow back to the hydraulic tank 44 . Air displaced by the fluid is vented through the tank control valve 64 โฒ. When the bed 12 has reached the desired angle, the operator releases the second pilot valve 68 โณ, forcing the cessation of the pilot signal to the shuttle valve 112 and the return of the skinner fluid valve 74 โฒ to its biased, closed position. The closure of the skinner fluid valve 74 โฒ stops flow from the bellows 46 , 48 to the hydraulic tank 44 and the bed 12 is maintained at the desired angle.
[0047] In one embodiment, an electrical interlock solenoid valve 116 is included in parallel with the skinner fluid valve 74 โฒ between the first and second hydraulic lines 80 โฒ, 114 . In one embodiment, a needle valve 118 and silencer 120 is included at the venting port of the tank control valve 64 โฒ. In one embodiment, a filter 122 is included at the inlet to the lift control assembly 42 โฒ.
[0048] Referring now to FIGS. 8 and 9 , an alternative mechanism for lifting and guiding vertical movement of a shaker separator (e.g., 10 of FIG. 1 ) may be described. In particular, each bellows ( 46 , 48 of FIGS. 1-7 ) may be replaced with a lifting mechanism 200 that includes a lifting apparatus 202 and a vertical alignment apparatus 204 . Lifting apparatus 202 includes two hydraulic bellows 206 , 208 sandwiched between a bottom plate 210 and a top plate 212 for transmitting hydraulic energy from a hydraulic line 214 (similar to 84 and 86 of FIG. 4 ) to lift either a free end or a discharge end of a separator shaker assembly. While lifting apparatus 202 is shown having two bellows 206 and 208 , it should be understood that fewer or more bellows may be used without departing from the scope of the present disclosure. Further, dual bellows 206 and 208 may be replaced with a single, larger bellows if desired.
[0049] Vertical alignment apparatus 204 extends between top plate 212 of lifting apparatus 202 and an adapter plate 216 (similar to 56 of FIG. 2 ) of the shaker separator. In selected embodiments, vertical alignment apparatus 204 is designed to ensure the displacement and forces transmitted from bellows 206 and 208 are substantially linear and vertical as would be desired by those having ordinary skill in the art. Alternatively, it should be understood that vertical alignment apparatus 204 may be angled such that displacement and forces are transmitted in a substantially linear, but not necessarily vertical orientation, if desired.
[0050] As such, vertical alignment apparatus 204 includes an actuated cylinder assembly 218 configured to reciprocate within a sleeve 220 affixed to a frame 222 of the shaker separator. Sleeve 220 may be affixed to frame 222 by any mechanism known to those having ordinary skill including, but not limited to, welding, bolting, press fitting, brazing, and the like. With sleeve 220 rigidly affixed to frame 222 , cylinder assembly 218 is able to linearly displace therethrough when actuated by top plate 212 . Further, by selecting the length and relative position of sleeve 220 within frame 222 , the top and bottom ends of sleeve 220 may be used to limit a maximum and a minimum amount of stroke of cylinder assembly 218 , described below in more detail.
[0051] Furthermore, cylinder assembly 218 includes an inner cylinder 224 , an outer cylinder 226 , and a top plate 228 . As such, an outer diameter of inner cylinder 224 is sized to engage through an inner diameter of sleeve 220 so that top plate 228 may be raised and lowered as bellows 206 and 208 of lifting apparatus 202 are inflated and deflated. An alignment ring 230 having an outer profile approximate to an inner diameter of inner cylinder 224 is rigidly affixed to top plate 212 so that cylinder assembly 218 is maintained in proper alignment at all times during the stroke of lifting apparatus 204 .
[0052] Additionally, outer cylinder 226 of cylinder assembly 218 extends downward from top plate 228 and includes an inner diameter larger than an outer diameter of sleeve 220 . Thus, outer cylinder 226 may act as a cap to prevent fluids and debris from entering the annular gap formed between sleeve 220 and inner cylinder 228 . Advantageously, by preventing fluids and debris from entering the annular gap between sleeve 220 and inner cylinder 228 , the same fluids and debris may be prevented from entering a compartment 232 within frame where lifting apparatus 202 , bellows 206 and 208 , and various other components are housed.
[0053] Furthermore, because shaker separator will experience to a large amount of vibration, a spring 234 may be mounted between top plate 228 of cylinder assembly 218 and adapter plate 216 to isolate lifting apparatus 202 and alignment apparatus 204 from vibrations. As such, a spring mount 236 may retain a bottom portion of spring 234 to top plate 228 , and a corresponding upper spring mount 238 may be mounted under adapter plate 216 . Furthermore, while only spring 234 is shown, it should be understood that a viscous coupling or other form of vibration dampener may be use in conjunction with or in place of spring 234 . Furthermore, one of ordinary skill in the art will appreciate that bellows 206 and 208 will also have inherent spring and dampening characteristics also.
[0054] Advantageously, lifting mechanism 200 enables hydraulic bellows 206 and 208 to be positioned below (e.g., in compartment 232 of frame 222 ) a shaking separator deck to be raised and/or lowered. Further, alignment apparatus 204 enables any lifting force from bellows 206 and 208 to be applied substantially linearly in a desired direction so that damage from long term vibratory side, or translational, loading is minimized. Furthermore, by locating lifting bellows 206 and 208 beneath the shaker deck, torsional loads to the deck resulting from the lifting forces may be reduced. Further, lifting mechanisms in accordance with embodiments disclosed herein may be positioned at either a free end of a shaking separator, a discharge end of the shaking separator, or at both ends (i.e., all four corners) control the amount and direction of relative shaker screen tilt desired.
[0055] While the claimed subject matter has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the claimed subject matter as disclosed herein. Accordingly, the scope of the claimed subject matter should be limited only by the attached claims.
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An apparatus to lift an oilfield machine includes at least one lifting bellows, an alignment assembly extending between at least one lifting bellows and an adapter plate of the oilfield machine, the alignment assembly comprising an inner cylinder to reciprocate within a sleeve of the oilfield machine, and the alignment assembly comprising a top plate at an upper end of the inner cylinder, the top plate configured to transfer forces from the at least one lifting bellows and the inner cylinder to the adapter plate, wherein the sleeve is configured to restrict the inner cylinder to a substantially linear displacements therethrough.
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BACKGROUND AND PRIOR ART
The present application is a continuation of application Ser. No. 337,434 filed Mar. 2, 1973, and now U.S. Pat. No. 3,831,522, entitled "Explosive Booster and Container Therefor".
As more fully explained in the parent application, it is often necessary or desirable in blasting operations to use boosters filled with a relatively sensitive explosive to fully detonate large masses of blasting agents which commonly are relatively less sensitive. That is, many blasting agents which are used on a large scale in mining and construction operations cannot be reliably set off or detonated by use of small conventional initiators such as electric blasting caps or lengths of detonating cord, the latter being slender tubular casings filled with sensitive explosive composition. In order to prevent waste of the main blasting agents and to avoid hazard due to their incomplete detonation, or to avoid failure of detonation, boosters are used which carry a sizable mass of an explosive of intermediate sensitivity. These are formed around the sensitive cap or cord which constitutes the primary initiator. Some of the prior art boosters may comprise or consist of a molded block of TNT (trinitrotoluene) in which a cap or other initiator of sensitive material is enclosed; see U.S. Pat. No. 3,037,452, for example. Some include a very sensitive primary cap, surrounded by a first small mass of explosive material which is quite sensitive and certain to be fully detonated by the initiator; this small mass in turn is surrounded by a still larger mass of semi-sensitive material (of which TNT may be typical). The latter is a so-called two stage booster. Variations are known in the prior art; see for example U.S. Pat. Nos. 3,037,453; 3,359,902; 3,379,906 and others.
In view of the hazards of shipping large quantities of blasting agents from manufacturing plant to a mine or other blasting site it has become the custom, to an increasing degree, to formulate explosives in the field. That is, the ingredients which make up the blasting agent and which, before being combined, are quite inert, may be shipped separately to the field, e.g., to a large open pit or underground mine, and then combined at the blasting site or near it just before they are used. To some degree a similar procedure may be desirable in preparing boosters. Since each booster includes at least one explosive composition in addition to the primary initiator (cap or detonating cord), it may be desirable to leave either the composition or the sensitive initiator, or both, out of the booster until it is at or near the site before making it ready for use. With most boosters of the prior art this is not feasible because they may require that the filler (such as TNT, for example) be melted at the factory for pouring into the booster casing. The manufacture of such boosters often is or may be a delicate operation which must be carried out under closely controlled conditions that cannot be performed conveniently in the field. Also, the main charge in the booster may be liquid or semi-liquid, in which case the filling operation cannot be reliably performed in the field but must be done with precision filling equipment, etc. However, in many cases, field filling of boosters is quite feasible if they can be designed for such.
Additional problems that may be encountered may involve the leakage of liquid filling materials out of filled boosters before they are used or the leaking of water into the booster after it has been filled and submerged in a borehole in the presence of ground water or in the presence of other liquids such as liquid components of blasting slurries. To form the booster so that it will not leak explosive material out or allow water to seep in, especially when the booster is submerged to a depth where hydrostatic pressure around the booster is high, can be a difficult problem with devices of the prior art.
An object of the present invention is to so design the booster shell or casing that it can be filled conveniently, in the field, if desired, and in a manner to avoid spilling or leakage. Preferably, the booster is filled completely enough that pockets of air or other voids are eliminated, and with liquid tight sealing all around the explosive charge which it contains. A further object is to so design the booster casing that it can resist high external pressure without collapsing and without making its walls so thick that it may fail to transmit the full detonation wave as required for full detonation of the main blasting charge. Still a further object is to design the shell or casing components so that separately formed parts may be locked securely together, preventing tampering after the booster is filled. It is desirable, also, that the design be such that simple filling operations be used, and an ancillary object is to design the interlocking parts so that, as first assembled, but not pressed to a fully closed position, the shell may be filled with liquid, semi-liquid, or plastic semi-solid material, or in some cases with a charge of granular or powdered booster material, while air inside the casing is permitted to escape as the filling material enters, and then by forcing the parts together more tightly after filling is completed, the parts are sealed securely against escape of the filler or entrance of water or other liquid from the outside, even when the booster is submersed to considerable depth under water or other liquid.
Additional objects include means for securely holding in proper place the primary detonator after the latter has been introduced into the booster. The booster is preferably formed so that the primary initiator, cap or blasting cord, may be inserted into a tubular holder and properly positioned and retained there, as near the center of mass of the booster material as is feasible. In situations where a single booster may be inadequate or marginally so, it may be desirable to use two or more boosters and a further object of this invention is to facilitate the assembly and holding together of multiple boosters when more than one is needed to insure full detonation of a main blasting charge.
Further objects, advantages and features of the invention will become apparent as detailed descriptions of the preferred embodiment and of minor modifications thereof are given.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an assembled booster shell or casing of a preferred form.
FIG. 2 is a view on a smaller scale of a plurality of boosters as in FIG. 1, secured together for multiple boostering as may be needed for detonating a blasting charge that is difficult to set off.
FIG. 3 is an exploded view of the booster casing of FIG. 1, showing its two main hemispherical or half shell components separated to better illustrate the internal construction.
FIG. 4 is a vertical sectional view of the booster shell of FIG. 1.
FIG. 5 is an enlarged sectional detail view, showing certain interfitting and interlocking elements which secure the half-shell elements of the casing together in liquid-tight relationship.
FIG. 6 is another enlarged sectional detail view, showing how a filler opening is provided when the parts are preassembled but still spaced from closed position, i.e., not tightly locked together.
FIG. 7 is an enlarged fragmentary sectional view showing the relationship between parts of two separate boosters assembled together for a multiple boostering operation.
FIG. 8 is a fragmentary sectional view showing details of the tube or receptacle which contains and holds a primary initiator or blasting cap.
FIG. 9 is a cross sectional detail of the tube, taken substantially along the line 9--9 of FIG. 8.
FIG. 10 is a horizontal sectional detail view through the base of a booster shell, showing means for receiving and holding a string, wire, or detonating cord for securing plural boosters together, for multiple boostering or for packaging or convenient carrying.
FIG. 11 shows a booster with a blasting cap and the necessary electric wires applied, as for detonation by an electric or spark type detonator.
FIG. 12 is a small scale view showing how the filling procedure may be modified for forcing viscous liquid or semi-solid plastic filler material into the casing.
DESCRIPTION OF PREFERRED EMBODIMENT
FIGS. 1 and 3 show a preferred general arrangement of the main elements which make up the shell or casing for a booster which has a large and generally spherical cavity to be filled with a semi-sensitive explosive material. This main booster charge is to be detonated by a primary initiator such as a cap or a blasting cord of conventional type. The casing or shell consists of two more or less hemispherical half shells 10 and 20 which are assembled or partly assembled prior to filling, the final step of assembly being completed after filling the main cavity 50 with the booster explosive, usually a semi-sensitive filler material. The upper half shell member or part 10 is formed with a dependent peripheral flange 12 having a generally cylindrical inner surface and the lower part 20 has its upper part 21 shaped to fit snugly into this cylindrical flange when the parts are fully assembled. A hollow cap or cord-receiving tube 14 is formed integrally with the upper half shell. At its top, the upper half shell member 10 has a cylindrical flange 16 projecting vertically, that is, concentric with the vertical axis of the shell or casing. A plurality of notches 18 are provided in this flange to receive cord or wire for tying parts together and/or for connecting to the initiator, as will be further explained.
The lower half shell or casing 20 has also a cap or cord receiving tube 27, preferably formed integrally with it, the parts preferably being produced by precision injection molding. Both the tube 14 and the tube 27 are formed with thin walls for most of their length so that the detonation wave of the initiator will be effectively transmitted to the booster filler, detonating the latter completely. This is done, of course, so that the main charge of blasting agent, in which the booster is positioned, will be fully detonated in turn by the booster charge.
The outer peripheral surface of the upper part 21 of the lower half casing 20 is formed with an essentially cylindrical surface 22 exteriorally and sized accurately so that it will enter and fit snugly within the bottom flange 12 of the upper part 10. These parts are formed with care so that even before the two halves are pushed fully or tightly together, as will be further explained, they form a reasonably firm and liquid-tight connection. The upper edge 26 of part 21 is rounded, shown in FIG. 5 at 26, and is designed to serve as a sealing element to prevent passage of liquid. When the parts are fully pressed together, edge 26 fits into a groove 15 inside the part 10, formed in a shoulder 80 at the inside top of flange 12. In addition, the part 21 bears a peripheral external rib 23 all around its cylindrical outer surface which is designed to interlock with a groove 17 formed peripherally inside the interior cylindrical surface of flange 12. The rib and groove parts interlock strongly to hold and lock the two half shells against separation after they have once been tightly pressed together. This prevents tampering with a filled booster. These parts also serve as liquid-tight seals, and in this function they are assisted by the interfit between the parts 15 and 26, as best seen in FIG. 4.
The bottom half shell member 20, as seen in FIG. 4, is provided with a downwardly depending circular skirt or flange 28 on which it may rest on a flat or plane supporting surface. This flange is notched at several points 29, spaced similarly around the periphery to match the notches 18 in the upper flange 16, to receive a cord or wire for detonation and/or for securing two or more boosters together. The flange 28 at the bottom is just enough larger in diameter than the flange 16 at the top, that the latter will fit neatly into it, thus providing for stable stacking or nesting the boosters or casings, and making it convenient also to secure two or more shells together for multiple boostering, as shown clearly in FIG. 2.
Openings 31 and 32, respectively, are formed in protruding bosses or pockets 33 and 34 in the upper part 10 and in the lower part 20, respectively. These protrusions 33 and 34 are of hemispherical or partly spherical shapes on the outside to facilitate connecting to them a filler nozzle 40, indicated in dotted lines at the bottom of FIG. 6. For filling the main cavity 50, FIG. 4, with liquid, and especially with a viscous liquid, such as a sensitized slurry, or with a thickened liquid or semi-plastic booster explosive, or a granular or powdered booster explosive, it is preferred that the explosive material be introduced at the bottom, through the filler nozzle such as 40, which may be of any conventional type. In this case the filler rises as it is introduced and the opening 31 at the top serves to permit air to flow out of the cavity 50 as it is filled. Obviously, when the parts are tightly assembled, as shown in FIG. 4, the bottom or filler opening 32 is closed with respect to cavity 50 by reason of the slightly tapered bottom end 39 of the detonator-receiving tube 14 fitting snugly into the similarly shaped and recessed inner part 41 of the protrusion 34. Similarly, at the top, the air cannot escape when the parts 10 and 20 are tightly assembled, as shown in FIG. 4. Then opening 31 is similarly closed by the slightly tapered upper end part 42 of the tube 27 which fits in a tapered socket 43. That is, when the parts are tightly and completely assembled, as in FIG. 4, no filler material can be introduced into the cavity 50 and no air, if entrapped therein, could escape. It is necessary, therefore, that the parts 10 and 20 be fastened together for filling but that the filler and air outlets remain open.
Consequently, the parts are fitted so that they may be brought together in a snug, interfitting preliminary but securely holding position without closing the main cavity 50 with respect to either the filler opening 32 or the air outlet opening 31. The relationships between the interfitting parts during a filling operation are shown best in FIGS. 5 and 6. In FIG. 5, the upper part of the hemispherical wall of part 26 is set part way only, not all the way, into the downturned flange part 12 of the upper half shell 10. The lower inside edge of flange 12 is flarged outwardly at its bottom edge as shown at 44, FIG. 5, to guide the sealing edge part 26 of the lower member into the cylindrical inner part of flange 12. The parts are pushed together only until the bead 23 on the lower part just begins to engage a groove 42 in this cylindrical inner portion of the flange 12. In this position, there is a liquid-tight seal between the inner part 22 and the inside surface of flange 12, both of these parts being essentially cylindrical in shape and close fitting.
Referring now to FIG. 6, the relationship between the lower end part 39 of tube 14 and the inner surfaces of boss or protrusion 34 are shown as of the time when the main half shell parts are in the relative positions shown in FIG. 5. That is, the tube 14 is set back from and does not block the opening or passageway from the filler tube or nozzle 40 into the main cavity 50. Filling material can be introduced then through the annular passageway 45, FIG. 6. In this Figure, the lower end of tube 14 is shown as being closed by a frangible plug 46. This plug is molded integrally with the tube and other parts of the upper half shell 10; it can be broken or cut out quite easily when and if it is desired to leave tube 14 open at both ends. In FIG. 4, tube 14 is shown to be open at both ends, to permit passage through it of a detonating cord or the like, as in FIG. 11.
Similarly, the upper end of the other tube 27 may be open, as in FIG. 4, or it may be closed by a similar frangible plug 48, as shown in FIG. 8. In the latter case, the plug 48 is provided with an extending part 49 which serves as a stop to position a blasting cap or the like as near as convenient to the center of mass of the booster explosive contained in cavity 50. In this case an electric blasting cap 60 of standard type is shown inserted in tube 27 with its upper end resting against the positioning stop 49 and with its wires 62 extending down towards a source of electric power, not shown, which will detonate the device. In order to hold the cap 60 in place properly, after it has been inserted, light vertical ribs or ridges 64 are formed to protrude inwardly in tube 27 and thus to frictionally engage the sides of the cap 60. These are shown in section in FIG. 9. On the other hand, if it is desired to use a cord type detonator and pass it entirely through the tube 27 (or the tube 14, or both) the frangible plug 48 and/or plug 46 may be broken or cut out to allow such passage. In either case the tube wall is made as thin as it may be to maintain sensitivity. Obviously, for filling with liquid explosive, and especially with a viscous liquid, the plug 46 at the filler opening should be left in place until the cavity 50 has been filled and the casing sealed shut. Obviously, also, the filler may be introduced through the top opening 31 instead of opening 32, if desired.
After the casing, assembled in preliminary position as shown in FIGS. 5 and 6, has been filled, with the liquid or other material inside cavity 50 rising to or substantially to the level of the air outlet opening 31 (which also is open for air flow, similar to opening 32 and passageway 45), the parts 10 and 20 are finally pushed tightly together into the positions shown in FIG. 4. When this is done, the rounded upper edge 26 of the lower member engages the groove 15 of the upper member and the rib 23 engages in the groove 17 as in FIG. 4 to further seal the parts together. In its thus filled condition the booster is capable of resisting very high external pressures and it may be submerged 100 feet or more under water, if desired, without collapsing and without letting water in or explosive material out.
When two or more boosters are assembled, as seen in FIG. 2 the bottom and top flanges 28 and 16, of the different boosters can nest together as previously explained. This is shown in FIG. 7. In addition, the hemispherical boss or protrusion 34 on the bottom of one booster, shown on top, FIG. 7, seats neatly into a similarly shaped and sized pocket 67 in the upper end of a tube 14 of the booster below. The upper boss or protrusion 33 of the booster below fits into a similar pocket or flared opening 68 at the bottom of a tube 27 in the booster above. Thus the parts are well supported and fit together neatly and firmly. Boosters may be tied together with strings or wire 70, FIG. 2, or by using a detonating cord or a detonating electric wire, as shown in FIG. 11. The notches 18 in the upper flange 16 and notches 29 in lower flange 28 are aligned when the boosters are assembled for multiple use (or simply for packaging) and the cord or wire is passed through these notches which are formed as shown in FIG. 10 with reinforcing indentations 72 into the main cavity 50.
For transportation to a site for use, it often may be preferable to leave the boosters unfilled, provision being made for filling at the blasting site for safety reasons. In this case the boosters may be assembled to the partly open or filling position as shown in FIGS. 5 and 6. Being open to the atmosphere, there is no problem with shipping them in airplanes or in storing at widely different altitudes because air can flow freely into or out of each casing through the openings 31, 32, 45, etc. The casings can thereafter be filled at the site and the detonating cap or cord can be inserted in position after filling or just prior to placing the booster in the explosive charge to be detonated. The safety features thus afforded are obvious.
For convenience in filling, it may be desirable to tilt the assembled casing slightly, at an angle to the vertical, more or less as shown in FIG. 1. In this position, as the casing is filled, as in FIG. 6, the filling material will rise to the outlet 31, thus making sure that all the air has been evacuated from the shell. As noted above, the completely filled casing or shell may be subjected to very high external pressures, particularly if the filling is a substantially incompressible liquid, as is often the case. The liquid may become solidified at lower temperatures but most liquids do not expand on freezing nearly as much as water does, so there is little or no danger of bursting the shell. When materials such as TNT are melted for filling, they do not expand at all on freezing; in some cases they may contract slightly but not enough to impair substantially the compressive strength of the booster.
The taper between parts 39 and 41, FIG. 6, or between parts 42 and 43, FIG. 4, is similar to that used in the "Leur Loc" system for hypodermic needles and the like. It assures a good tight seal without press fitting.
As shown best in FIG. 4, the tube 27 which is integral with the lower half shell 20 is quite thin-walled for most of its length, to provide for effective transmission of the shock wave from the initiating cap or blasting cord through the wall to the semi-sensitive explosive filler material in the main cavity 50. This is a preferred arrangement. However, the base portion of either tube such as 27 or 14 may be somewhat greater in thickness, as shown at 74 for greater strength and to provide a shoulder 75 against which a ring or doughnut type explosive mass 78 may be set. In some cases, it may be desirable to use such a mass as a first stage of a two-stage booster, in a manner analogous to that described in U.S. Pat. Nos. 3,037,452, 3,371,606, and others. A similar construction including a shoulder 76 may be used for tube 14.
The top and bottom flanges 16 and 28 serve several useful functions. They give protection to the sealing parts 39, 41, and 42, 53 which they surround. They provide for nesting one container or booster in another to facilitate packaging and shipping as well as for multiple boostering. Through the notches 18 and 29 they provide anchorage for tying cords, or electric blasting cap wires or for cord type detonators. They also facilitate the connection and alignment of conventional filling nozzles 40 for introducing liquid or granular filling into the main cavity of the booster. They provide also a stable base for setting the booster on a plane supporting surface, so that it will not roll away. Thus they facilitate storing, stacking and handling of the empty or filled booster casings.
In certain cases, for example, when the booster is to be filled with a thick slurry or a very viscous or semi-solid liquid, it may be desirable to invert the booster from its normal position, where it is shown, as in FIGS. 4, 6, and others, to a position as shown in FIG. 12. The reason for this is that the flange 12 includes the shoulder 80 which is particularly suitable for giving strong support against the thrust of a viscous liquid flowing through the openings such as 32 and 46 without closing the filling channel. Openings at the top, as at 31, etc., are identical with these; by using a ring shaped back-up or thrust resisting member 82 above this flange 12, the nozzle 40 may be held with greater force against the filler opening 31 than in the case of the arrangement of FIG. 4. That is, if the parts 10 and 20 were partly assembled, as for normal filling, see FIG. 6, and a substantial thrust were exerted against the bottom member 20, FIG. 5, the booster would close or tend to close up to the position shown in FIG. 4, thus shutting the annular filling opening 46, FIG. 6. By backing the flange 12 against the solid back-up ring 82 placed above it, as in FIG. 12, filling can proceed without risk of forcing the container to fully closed position. This, if it occurred, would prevent complete filling. For normal operation, the arrangement shown in FIGS. 4, 5 and 6 is preferred because the flange 28 is somewhat larger in diameter than flange 16 and provides a somewhat more stable base to rest the booster on, before, during or after filling.
From the above description, it will be appreciated that the booster casings of the present invention have a number of advantages over prior art products. Some of these may be summarized as follows:
a. There are only two injection molded half shells, so no caps, lids, sealing strips, or other closures or auxiliary parts are needed.
b. The casings are suitable for injection molding from various kinds of suitable synthetic plastic or resinous materials at low cost, using multi-cavity, runnerless, automatic molds that require no moving cores.
c. The parts are readily made in various sizes, as needed, and of sufficient dimensional accuracy that they form effective mid-seal and port seals, being well locked together without tape, cement, or fasteners of any kind and being particularly suitable for final loading at the blasting site for greater safety.
d. They are waterproof, capable of being submerged in water or in slurry explosive to depths of 100 feet or more, and they are not adversely affected by wide changes in altitude for shipping or storing.
e. They can be molded selectively for varying uses and environments from a wide variety of thermoplastic or thermosetting resins for maximum resistance to various chemicals or other materials.
f. Their essentially spherical configuration provides maximum boostering efficiency, maximum mechanical strength and rigidity and they are suitable for substantially bubble-proof filling.
g. They can be used with a wide variety of initiators, including fuse or electric blasting caps, detonating cords, etc.
h. Explosive reliability is assured because of the thin walled tubings in which the primary initiators may be placed at optimum positions.
i. Filling ports are large enough to permit use of very viscous and even non-liquid or semi-solid filler materials, including many kinds of explosive compositions.
j. The shells are designed for filling either at factory or blasting site with automatic equipment or they may be filled manually, using simple equipment.
k. Being designed for stacking or nesting, they simplify packing, shipping and use in multiple boostering operations.
l. The booster casings are neat and efficient in appearance and design.
It will be obvious that various modifications and alterations may be made in the booster casings of this invention, including those mentioned above and many not mentioned, without departing from the spirit and purpose of the invention. It is intended by the claims which follow to cover such modifications, variations and alterations as would suggest themselves to those skilled in the art as broadly as the state of the art properly permits.
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A casing or shell for explosive material to be used as a booster for detonating massive charges of blasting agents of low sensitivity is formed in two generally hemispherical half shell or casing members which are formed with sufficient precision that the two parts may lock together in telescoped relationship after filling, to form a liquid-tight joint. The two half shells are quite similar in size and shape but not identical, one bearing a flange having a hollow cylindrical inner surface into which a mating flange on the other is received; interlocking elements inside the outer flange and on the exterior surface of the inner flange hold the parts securely together by friction and without adhesive after full assembly. Each half shell includes a thin-walled tubular element which projects through and frictionally engages an opening in the other half shell as the two members are assembled, the parts being so arranged that a filling port and an air outlet port are provided when the parts are brought together but only partially closed to final position, these ports being closed completely when the two half shells are finally forced tightly together. The tubular elements are designed to receive and hold a primary detonator, such as an electric blasting cap or a length of detonating cord, and to hold such detonator securely in place after the booster is filled and sealed.
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This application claims the benefit of provisional application 60/175088, filed Jan. 7,2000.
FIELD OF THE INVENTION
The present invention relates to methods and apparatus for detecting and preventing undesirable scale deposition, and more particularly relates, in one embodiment, to methods and apparatus for detecting and preventing undesirable scale deposition that employ electrodes which intentionally cause scale deposition as a diagnostic indicator.
BACKGROUND OF THE INVENTION
The accumulation of inorganic mineral scales in oil field formation and production equipment is a major problem for the oil industry. Deposition of inorganic mineral scale in oil-bearing formations and on production tubing and equipment causes significant and costly loss of production. Other industries have similar problems with scale deposition. The primary offenders are carbonates and sulfates of calcium, barium and strontium. These compounds may precipitate as a result of changes in pressure, temperature and ionic strength of produced fluids or when connate reservoir waters mix with injected waters during secondary recovery operations. In order to avoid costly losses in production or post-scale treatments, it is necessary to prevent deposition of scale downhole as well as in post production processing. Scale is a particular problem when equipment is in contact with certain brines.
Current scale probes indicate the onset of scale deposition. However, in order to take preventive action, an advance sensor is required which detects the onset of scaling conditions before actual scale deposition occurs on the surfaces to be protected. The advantage of such a sensor would be that time for preventive measures is gained and the need for remedial work is avoided. It would be advantageous if a scale prediction probe could be devised which would be able to determine conditions just prior to when undesirable scaling would occur.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method and apparatus for preventing scale from forming on surfaces, particularly oil field production equipment.
It is another object of the present invention to provide a scale prediction probe which would be able to determine conditions just prior to those under which undesirable scaling would occur.
In carrying out these and other objects of the invention, there is provided, in one form, a method for predicting scale deposition in a general environment which involves providing a localized environment where scale is preferentially formed first (relative to the general environment), where the localized environment is adjacent the general environment, and monitoring the deposition of scale in the localized environment. Preemptive action may thus be taken to prevent scale deposition in the general environment in response to the results obtained from monitoring the deposition of scale. Finally, the intentionally formed scale is removed from the localized environment so the method can be practiced again.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an electrode configuration for a calcium carbonate scale sensor in accordance with the apparatus and method of this invention, where FIG. 1A schematically shows a scale free electrode at time t=0, and where FIG. 1B schematically shows a scaled cathode at a later time t=t;
FIG. 2 is a graph of voltage potential v. current density in a current/voltage relationship at the scale sensing electrode of this invention under various conditions; and
FIG. 3 is a schematic diagram of an electrode configuration for a barium sulfate or strontium sulfate scale sensor in accordance with the apparatus and method of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The scale prediction probe of the present invention provides a surface that will preferentially scale over before any other surface in the general area. Stated another way, scale-forming conditions are intentionally caused to be formed in a localized environment adjacent a general environment so that scale forms on that localized environment or surface before any other surface in the general environment has scale deposited thereon. Further, the degree of โover scaling potentialโ may be controlled and remotely adjusted to suit individual conditions.
It may thus be understood that the inventive scale prediction probe may be used to predict, and thus prevent, the deposition of undesirable scale in the general environment. It should be recognized that this concept of prediction is different from that used by some researchers where โpredictโ is used to mean being able to accurately measure the amount of scale formed on a surface.
Two probe embodiments form the basis of the invention. The first embodiment uses an inert electrode with a controlled surface pH, and the second embodiment is a dual surface probe where one area generates a controlled release of sulfate ions, for example, and the second surface acts as the scale collector. The first embodiment is for the prediction of calcium carbonate scale deposition and the like, in one non-limiting case, while the second embodiment is for barium and strontium sulfate scale deposition prevention, in other non-limiting cases.
During cathodic protection in sea water and other saline solutions (brines) the cathodic surface becomes coated with scale in preference to nearby non-cathodic surfaces. This scale deposition is induced due to the electrical generation of alkaline conditions at the electrode surface. This high surface pH can be caused as described below. The effect of the localized increased pH is to drive the scaling reaction such as that depicted below:
Ca 2+ +2HCO 3 โ โCaCO 3 โ+CO 2 +H 2 O
The increase in alkalinity of the electrode surface is generated by an applied electric current. This current may be controlled either galvanostatically, potentiostatically, or may have some time-dependent voltage/current control. The electrode may be of the same or different material as the system, but should not generate scaling species. Carbon steel may be appropriate in some conditions due to the cathodic polarization induced by the recording and stimulating equipment. Preferably, the electrode is an inert electrode material such as platinum-plated or platinum-coated titanium. However, the invention is not limited to any particular metal for the electrodes.
FIG. 1 provides a schematic diagram of the principal parts of the invention; however, it would be appreciated that the actual configuration used in practice would depend on the individual system in which the sensor would be installed. The electrode configuration or apparatus for the calcium carbonate scale inhibitor of FIG. 1 is generally referred to as 10 , where the reference electrode 12 may be positioned adjacent the cathode 14 which is opposite and adjacent (in another, facing direction) the auxiliary electrode 16 having fluid flow in the direction indicated. Note the cathode 14 and anode 16 are downstream from the reference electrode 12 . The reference electrode 12 is used to measure the electrical potential of the cathodic or working electrode 14 . Measurements taken by reference electrode 12 are used by the instrumentation to control the potential/current applied by the auxiliary electrode 16 on the cathodic (working) electrode 14 . Reference electrode 12 also provides a fixed point of reference for comparison of electrochemical potentials in other systems (where a recognized standard reference electrode is utilized).
FIG. 1A shows the apparatus 10 at some initial time, t=0, where cathode 14 is scale-free. FIG. 1B shows the apparatus 10 at some later time, t=t, where the cathode 14 has scale 18 deposited thereon. It will be appreciated that the early detection of carbonate scales other than calcium carbonate could be achieved by the method and apparatus of this embodiment. It will also be appreciated that cathode 14 and anode 16 make up the localized environment in one embodiment of the invention. The localized environment is adjacent the general environment 17 . Generating the applied electric current across cathode 14 and anode 16 conditions the cathode 14 to be slightly more scaling than the bulk fluid.
The measurement of intentional scale build-up on the electrode depends upon the detection of the diffusion limited current due to the reduction of a suitable species in the electrolyte. For example, in sea water, oxygen is reduced to hydroxyl ion, and diffusion of the gas to the electrode surface is increasingly limited by the build-up of scale. This results in a diffusion-limiting current at the electrode surface. FIG. 2 shows the effect of scale build-up on the current voltage relationship at the electrode surface. The values of the diffusion limiting currents (I lim 1 , I lim 2 , and I lim 3 ) are given at three different times or scale levels, with scale increasing on the cathode in the direction right to left in FIG. 2 . That is, I lim decreases with time as scale is formed on the electrode. FIG. 2 is an example of how the curve would move with time.
The diffusion limited current may be detected by electrochemical methods other than the full potential sweep shown in FIG. 2, such as electrochemical impedence measurements and current potential logging, as non-limiting examples among others. In essence, impedence measures the response of the working electrode to a varying applied potential frequency in terms of electrical impedence. Current potential logging measures the current passing between two electrodes and the potential of the electrodes. This data is then statistically analyzed.
The surface pH is dependent upon the cathodic current density and the rate of diffusion of alkaline species away from the electrode and the rate of diffusion of acidic species toward the electrode. If the temperature, surface geometry, current density and flow characteristics of the brine or other fluid are known, then by using Fick's laws of diffusion and basic chemical/electrochemical equations, the surface pH may be calculated. Control of the surface pH is less accurate using calculated values from diffusion laws (e.g. Fick's law) due to variability of hydrodynamics, etc., and would only be used as a โsighting shotโ or to determine approximate settings for obtaining empirical data. Alternatively, control values may be obtained from experimental data and used for other conditions by interpolation or extrapolation.
If the auxiliary and working (cathode or sensing) electrode are identical, then they may be interchanged, or the auxiliary may be used as a blank scale reference/normal scaling potential reference. An additional benefit of this technique is that electrode cleaning of a scaled surface is possible by applying a high current density to the electrode that has the effect of generating gas bubbles that disrupt and remove the scale from the electrode surface. Thus, the electrode surface can be used for accurate monitoring again.
As the presence of scale is detected through reduction in current density as shown, the scale prediction probe can give a signal for the release of a certain, predetermined amount or rate of scale inhibiting chemical or agent into the fluid of the system. This step may be initiated when the current density falls below a certain preset threshold. Such a preset threshold would be individual for each system and could not be specified in general or in advance. By injecting scale inhibiting agents or chemicals only when needed, conservation of the agent and costs associated therewith can be achieved. Scale inhibiting chemicals and agents are well known in the art. Additionally, the use of injection mechanisms such as nozzles, pipes, needles, and the like are also well known in the art. Similarly, the removal of scale by applying a high current density to the electrode as described above could also be triggered or caused once the current density falls below a certain preset threshold.
In the embodiment for barium and strontium sulfate scale deposition, one change to the above embodiment is there is present an additional surface suitable to generate a controlled release of sulfate ions.
The formation of sulfate-containing scales is not strongly affected by pH, and thus the above embodiment cannot create an increased scaling tendency for these scale types. However, by the introduction of a local excess of sulfate ion (barium or strontium, for example, where appropriate), over the bulk concentration of these ions, then the local scaling tendency will be increased. This latter technique is the basis of the sulfate scaling tendency embodiment of the invention.
Shown in FIG. 3 is a schematic diagram of an electrode configuration for a barium sulfate or strontium sulfate scale sensor. The electrode configuration is generally denoted as 20 . The detecting or scaling electrode 22 (corresponding to the cathode 14 in the carbonate scale detection embodiment) is immediately down stream of a sulfate generating electrode 24 , the sole purpose of which is to generate a controlled excess of scaling ion (sulfate, barium, strontium, etc.). This excess ion then drifts over the sensing electrode 22 (i.e. the working electrode, as in the previously described embodiment) and causes deposition when the bulk fluids are close to saturation with respect to the scale being deposited on the sensing/detecting electrode 22 .
The comparator electrode 26 shown in FIG. 2 is similar to the sensing electrode 22 down stream of the generating electrodes and serve the purpose of determining if the actual system is in a scaling condition without the presence of the excess ions supplied by electrode 24 . Counter electrodes 30 serve the function of auxiliary electrodes 16 in the FIG. 1 embodiment.
The generation of sulfate, barium or strontium scaling ions for producing an excess scaling tendency is necessary for the second embodiment, for without it, the electrode sensor 22 will only detect scale at the same time the entire system experiences the onset of scaling.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. However, it will be evident that various modifications and changes can be made thereto without departing from the broader spirit or scope of the invention as set forth in the appended claims. Accordingly, the specification is to be regarded in an illustrative rather than a restrictive sense. For example, scales other than those specifically mentioned, and electrode configurations other than those specifically shown and described, falling within the claimed parameters, but not specifically identified or tried in a particular application to inhibit scale formation, are within the scope of this invention.
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A method for predicting scale deposition in a general environment has been discovered which involves providing a localized environment where scale would preferentially form, where the localized environment is adjacent the general environment. Monitoring the deposition of scale in the localized environment is performed for the purpose of taking preemptive action to prevent scale deposition in the general environment once scale begins to form, or a certain threshold is reached. Scale is removed from the localized environment so that monitoring can be performed by the probe again. Preemptive action will often be the introduction of a scale inhibiting agent into the general environment. An apparatus for practicing the method of predicting and preventing scale deposition in a general environment is also described.
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FIELD OF THE INVENTION
[0001] The invention relates to diagnosing lymphoma in cats; more specifically the invention provides a method and system for diagnosing the presence of lymphoma cancerous cells through the measurement of thymidine kinase enzymatic activity in the blood.
BACKGROUND OF THE INVENTION
[0002] Lymphocytes are found in various organs of the body in vertebrates, and are part of the immune system. They attack foreign bodies, and in instances of cells that have been infected with a virus, they attack the body's own cells. But, Lymphocytes can become cancerous and cause a cancer known both as Lymphoma or Lymphosarcoma. Since lymphocytes are found in multiple organs, cancerous lymphocytes may develop a tumor in a variety of organs.
[0003] In cats, where lymphoma is a common cancer, diagnosing Lymphoma is problematic, due to the fact that the symptoms may vary depending on the affected organ. For instance, the symptoms that develop as a result of Lymphoma in cats such as loss of appetite, weight loss, vomiting and diarrhea, that are also typically indicative of Inflammatory Bowel Disease (IBD). Relying on these symptoms alone may lead to a miss-diagnosis of IBD, when the real underlying disease is Lymphoma.
[0004] Consequently, mistakenly diagnosing IBD instead of Lymphoma may lead to treatments that typically involve using steroids (e.g., Prednisone). The steroid treatment, although appears to relieve the symptoms, promotes the progression of cancerous cells, thus complicating the detection of the true cause of the symptoms (i.e., lymphoma), and later treatment of lymphoma.
[0005] The existing approach to detecting lymphoma is through a histological investigation, which involves a biopsy i.e., a surgical procedure to collect tissue, and testing to detect the presence of cancerous cells. A laboratory test may be, however, too costly, and may only be carried out at a late stage of the diagnosis elimination process i.e. after other conditions have been ruled out. As consequence, the delay caused by going through the diagnostic stages until a trial diagnosis of lymphoma is conducted, may be detrimental to the success rate of the treatment of the cancer once it has been established.
[0006] Therefore, what is needed is a method and system that allows a practitioner to detect, with a high probability, the presence of lymphoma in cats in order to guide further diagnoses of the disease, thus reducing the cost through avoidance of conducting multiple diagnoses, preventing miss-diagnoses which may lead to treatments, which may worsen the cancerous condition, and allow for an early diagnosis of lymphoma, before further growth and/or formation of metastases, which may be highly beneficial to the success rate of the cancer treatment once cancer has been established.
SUMMARY OF THE INVENTION
[0007] The invention discloses a method and system that enables a care giver to diagnose the presence of lymphoma in cats. In cases when symptoms may point to inflammatory bowel disease (IBD), a diagnosis conducted in accordance to the teachings of the invention would allow the practitioner to determine whether the symptoms are due to inflammatory bowel disease or to lymphoma.
[0008] The invention relies on the measurement of thymidine kinase in the blood circulation to determine whether a cat has a high probability of having lymphoma. A higher-than-normal presence of thymidine kinase in the blood is indicative of the presence of lymphoma, in accordance with the teachings of the invention.
[0009] The invention teaches to measure the enzymatic activity of thymidine kinase, and provides a level of enzymatic activity of thymidine kinase in the the blood at/or above which the practitioner may suspect a high probability of presence of lymphoma.
[0010] The method and system disclosed herein allow a practitioner to detect a probability of presence of lymphoma in cats in order to guide further diagnoses of the disease. Thus the invention provides means to reduce cost by the avoidance of conducting multiple diagnoses, preventing miss-diagnoses which may lead to treatments that may worsen the cancerous condition, and allow for an early diagnosis of lymphoma, before further growth and/or formation of metastases, which may be highly beneficial to the success rate of the cancer treatment once cancer has been established.
[0011] The method and system of the invention may also be used for routine monitoring of suspected cases, such as in some breeds that are prone to developing lymphoma, and/or provide routine testing following a treatment for lymphoma. The method and system of the invention may also be useful for providing a prognosis for expected survival based on the level of presence of thymidine kinase in the blood stream.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a flowchart diagram showing method steps carried out to diagnose lymphoma in cats, in accordance with an embodiment of the invention.
[0013] FIG. 2 is a block diagram representing components of a system for diagnosing lymphoma in cats in accordance with an embodiment of the invention.
[0014] FIG. 3 is a plot of the results of measuring thymidine kinase in three groups of cats, one group affected by lymphoma, the second group affected by inflammatory bowel disease, and the third group that is unaffected by either inflammatory bowel disease or lymphoma, in accordance with the teachings of the invention.
[0015] FIG. 4 is a scatter plot of individual measurements obtained from a test study conducted in accordance with the teachings of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The invention provides a method and system that allow a practitioner to detect a high probability of presence of lymphoma in cats. In order to guide further diagnoses of the disease, thus reducing the cost by the avoidance of conducting multiple diagnoses, preventing miss-diagnoses which may lead to treatments that may worsen the cancerous condition, and allow for an early diagnosis of lymphoma, before further growth and/or formation of metastases, which may be highly beneficial to the success rate of the cancer treatment once cancer has been established.
[0017] In the following description, numerous specific details are set forth to provide a more thorough description of the invention. It will be apparent, however, to one skilled in the pertinent art, that the invention may be practiced without these specific details. In other instances, well known features, and procedures, have not been described in detail so as not to obscure the invention. The claims following this description are what define the metes and bounds of the invention.
[0018] Thymidine kinase (โTKโ) is an enzyme that phosphorylates thymidine, one of the building blocks of DeoxyriboNucleic Acid (DNA). TK is a salvage enzyme that is present in cells preparing to undergo cell division, a stage to which it is also referred as mitosis. Once TK is no longer needed, it is broken down through a special cellular mechanism, although, a portion of TK escapes to the blood stream. Therefore, in healthy subjects, the amounts of TK found in the blood stream are very low. In the presence of a tumor, however, the amount of TK released in circulation is relatively high, which is likely due to the disruption of cell membranes of dead (or dying) cancerous cells.
[0019] The invention utilizes the presence of TK in amounts higher than levels found in the blood stream of healthy subjects to serve as an indicator of the presence of malignant cell proliferation. Furthermore, the level of TK may also be correlated with the aggressiveness of the tumor.
[0020] Thymidine kinase is a protein, it may be isolated and measured in the the blood using any of the available methods for isolating and measuring proteins. However, the specific enzymatic property of TK provides a method of measuring the amount of TK present in a fluid by characterizing its enzymatic activity in a controlled biochemical reaction.
[0021] In accordance with embodiments of the invention, enzymatic characterization is carried out by providing the initial substrates for the biochemical reaction in a solution that is added to a solution containing TK. The result of the biochemical reaction is selected to be a product that can be measured in the solution either directly or following one or more treatments, such as coloring and/or forming a complex with a marker such as an antibody. The activity of an enzyme is characterized by the amount of substrate consumed through the enzymatic reaction per unit of time under defined conditions.
[0022] While other methods for measuring the concentration of TK may be used by embodiments of the invention, one embodiment of the invention utilizes the measurement of the enzymatic activity of TK in order to determine a level of activity that enables a practitioner to cost-effectively determine a probability that a cat carries lymphoma.
[0023] Tests have been conducted using the teachings of the invention in order to determine a level of TK in the blood stream that may be used as a marker of the presence of lymphoma. Blood serum was collected from two (2) groups of cats. Both groups showed symptoms that included one or more of loss of appetite, weight loss, vomiting and diarrhea, which may lead a practitioner to diagnose the affected cats with inflammatory bowel disease (IBD). However, the groups in the test were properly diagnosed for lymphoma through other means, such as histological laboratory tests. One group was labeled as a lymphoma-positive and the other as a lymphoma-negative.
[0024] Using the method of the invention, TK serum was collected from each individual, and TK activity measured. The results showed most individuals that has been shown to be lymphoma-positive had a serum level of TK that was 15.5 Units/L or higher. The lymphoma-negative subjects, on the other hand, had a level of TK in the serum that was mostly below 15.5 Units/L. At the latter level, statistical analysis showed a significant difference between the two groups. Thus, the invention provides a threshold level that points to a probability that a subject under diagnosis may carry lymphoma based on the result of testing TK activity in the serum of that subject.
[0025] FIG. 1 is a flowchart diagram showing method steps carried out to diagnose lymphoma in cats, in accordance with an embodiment of the invention. At step 110 , blood is collected from a cat. The latter step is carried out in accordance with standard practices for collecting blood from a cat or any other animal.
[0026] The blood sample may be submitted to extraction of the serum portion, at step 120 . The latter step may involve using a centrifuge to separate blood cells from serum. However, an embodiment of the invention may utilize any available method to obtain a portion of the collected blood measurably containing thymidine kinase. The portion of blood to be submitted to the detection test may also contain thymidine kinase isoenzymes. Isoenzymes are enzymes that may vary in their structure, but perform similar enzymatic function.
[0027] A method in accordance with the invention may utilize a portion of serum of at least 150 ฮผl, obtained by separating the serum portion of the blood sample previously obtained. The amount of serum utilized may vary depending on the method implementing the invention, provided that the amount of serum is measured accurately for the purpose of accurately calculating the level of enzymatic activity per unit of blood volume.
[0028] At step 130 , a predetermined quantity of extracted blood is submitted to a test that measures the concentration of TK in the blood. For example, the test may involve measuring the enzymatic activity of TK. Once the concentration of TK is measured, at step 140 a test of the concentration is compared with a predefined threshold (e.g., 15.5 Units per liter) that indicates whether the subject has a high probability of having lymphoma. At step 150 , a lower amount of TK is detected, and the diagnosis points to an absence of lymphoma.
[0029] At step 160 , a determination is made that a cat has a high probability of having lymphoma based on the an amount of TK higher the set threshold. Then at step 170 , further tests are carried out to further diagnose lymphoma in the affected cat.
[0030] FIG. 2 is a block diagram representing components of a system for diagnosing lymphoma in cats in accordance with an embodiment of the invention. The latter system utilizes the enzymatic property of TK to detect the amount of TK in a blood sample. However, the invention may utilize one or more methods for detecting the amount of TK present the blood using a system that implements the components represented in FIG. 2 .
[0031] Block 210 represent a subsystem that prepares the compounds used as a substrate for the enzymatic reaction which TK will be catalyzing. The substrates comprise a thymidine provider and a phosphate donor. The latter substances are selected with the goal that a chemical reaction (e.g., phosphorylation) occurs specifically due to the presence and action of TK present in blood sample.
[0032] For example, the thymidine provider may be 3โฒ-derivative of thymidine. The phosphate donor may be a nucleoside triphosphate suitable to transfer a phosphate group to a substrate such as adenosine triposphate (ATP) or cytidine triphosphate (CTP).
[0033] Block 220 represents a subsystem used to prepare blood samples, or samples of a portion thereof. For example, the subsystem may include one or more centrifuges, electrophoresis systems, filtering systems, cooling and heating systems and any other system that may be utilized to separate a portion of the blood, and preserve samples for immediate and/or delayed use. The subsystem represented by block 220 , comprises a sample transport system that enables a practitioner to prepare blood samples in one location and transport the samples to another location for testing, while preserving the physical, chemical and biochemical properties of the samples.
[0034] Block 230 represents a subsystem where the biochemical reactions take place by mixing the substrates and the blood sample. Subsystem of block 230 may include a system of precision pipettes, test tubes, automated mechanisms for collecting aliquots and any other available machine for carrying out a biochemical reaction in order to measure the amount of a protein, such as an enzyme, and/or characterize a level of its activity.
[0035] In an embodiment of the invention, subsystem 230 is a machine equipped with a pipette system capable of carrying out a batch of reactions in parallel. The system mixes a quantity of blood sample with a quantity of thymidine compound and phosphate donor in order to allow the TK present in the blood to catalyze a biochemical reaction. The latter is a phosphorylation reaction of a thymidine derivative.
[0036] Block 240 represents a marker provider. A marker may utilize any of the physical properties that allow for detecting the quantity of a substance. For example, a marker may carry a luminescent compound, that can be detected and the concentration of which measured by measuring a light emitted by the compound. In other instances, the marker may be fluorescent, carry a radioactive isotope, magnetized beads or any other physical property that facilitates processing of the reaction solution and/or detection of compounds. Furthermore, the marker is typically manufactured to attach to a specific molecular target, such as the product of the biochemical reaction, and form a molecular complex that can be specifically measured. The means for attaching the marker to the product typically utilize an antibody that is specifically manufactured to attach to the target reaction product.
[0037] Block 250 represents one or more components of the system that allow for measuring a product. The latter subsystem may be an integral part of the reactor 230 , and may involve automated mechanisms for washing a product, one or more compounds for increasing the sensitivity of the detection and any other component of a system that facilitates measurement of the reaction product. Block 250 , also represents one or more machines for detecting the reaction product. For example, block 250 may include one or more spectrometers, immunoassay measurement systems and any other necessary tool for measuring the amount of the reaction product.
[0038] The following is a test setup for diagnosing lymphoma in cats using the enzymatic activity of TK as a means to measure the amount of TK present in a sample of blood. For each sample, approximately 500 ฮผl of serum was provided. Each sample was labeled with a database code for blind testing and patient identification. The control group included cats that showed symptoms of IBD. From each cat approximately 3 ml whole blood from a peripheral vein was extracted into a red-top tube. For each sample serum were separated from the cells within 60 minutes and the samples were then frozen immediately.
[0039] The blood samples were then defrosted and analyzed using the LIAISONยฎโข. Thymidine Kinase Assay Procedure (Registered to DioSorin S.P.A of Italy). The analysis included reacting each sample with a substrate having 3โฒ-derivative of thymidine in the presence of a phosphate donor and a buffer system. The phosphate donor was a nucleoside triphosphate suitable to transfer a phosphate group to a substrate such as adenosine triposphate (ATP) or cytidine triphosphate (CTP). The buffer system included 10-100 mM HEPES or Tris with pH ranging from 6.8-8.0, 1-30 mM DTE, 0.2-8 mM ATP and MgCl 2 at a concentration of at least two times the concentration of ATP. The substrate contained 3โฒ-derivative of thymidine. A more detailed discussion of the assay can be found in patent application publication No. 2006/0035295 A1 to Oehrvik et al., the specification of which is incorporated herein in its entirety by reference for background information.
[0040] The LIAISONยฎโข TK assay procedure includes a two-step, competitive chemiluminescence immunoassay (CLIA) for quantitative determination of TK in serum and EDTA plasma. The assay utilizes an initial enzymatic reaction in which TK in the sample converts AZT (3โฒ-azido-3โฒ-deoxythymidine) to AZTMP (3โฒ-azido-3โฒ-deoxythymidine mono phosphate). This is followed by a competitive immunoassay for the quantitative determination of AZTMP. The amount of AZT converted to AZTMP is a measure of the amount of TK present in the sample.
[0041] In some tests, 50 ฮผl of sample was incubated with 100 ฮผl of Assay Buffer 1 , 20 ฮผl of Assay Buffer 2 , and 20 ฮผl of paramagnetic particles coated with anti-AZTMP polyclonal antibody. Rabbit anti-goat IgG, then anti-AZTMP goat polyclonal is coated to the solid phase.
[0042] The sample incubated for about 40 minutes and then 100 ฮผl of tracer, an AZTMP analogue conjugated to an isoluminol derivative is added. During the first incubation, AZTMP binds to the solid phase. In the second incubation, the tracer conjugate competes for binding with the AZTMP in the solution. After a 20 minute incubation, the unbound material is removed with a wash cycle. The starter reagents are then added and a flash chemiluminescent reaction is initiated. The light signal is measured by a photomultiplier as relative light units (RLU) and is proportional to the concentration of TK present in calibrators, controls, or samples.
[0043] FIG. 3 is a plot of the results of measuring thymidine kinase in three groups of cats, one group affected by lymphoma, the second group affected by inflammatory bowel disease, and the third group that is unaffected by either inflammatory bowel disease or lymphoma, in accordance with the teachings of the invention. Plot 300 shows the data plots for a group affect by lymphoma 320 , a group affected with IBD 310 , and a group unaffected by either lymphoma or inflammatory bowel disease 360 . The third group is considered to show normal levels of TK activity, hence the third group is labeled as โNormalโ. The ordinate axis 330 shows the enzymatic activity of TK in Units per liter. The vertical bars (e.g., bar 340 ) respectively represent the spread between the maximum and the minimum values of measured activities for each group. For each group, a box (e.g., box 350 ) represents the level of measured TK activity respectively corresponding to the first quartile of the group, represented by the bottom of the box, and the third quartile of the group represented by the top of the box. The width of each box represents no statistical data.
[0044] The dash line 370 graphically represents 15.5 U/l cutoff value determined to be an indicator above which an animal may be suspected of having LSA. In some cases, the measured TK activity level may for a given subject exceed a predetermined maximum level. For example, given a maximum value (e.g., 100 U/l) of the range of sensitivity of a given method for measuring TK activity, a measurement of TK level would only show 100 U/l even as the true value may be much higher than 100 U/l. In the method provided by the invention the latter inaccuracy is not a concern, since a higher than the cutoff level is already indicative of a high probability that the subject under test has LSA.
[0000]
TABLE 1
Test Resultsfrom three (3) groups.
LSA
IBD
Normal
Third Quartile
34.5
12.3
12.2
Maximum
>100
23.5
17.4
Median
21.2
9.5
8.7
Minimum
3.2
1.2
3.2
First Quartile
12.4
5.7
6.3
[0045] Table 1 provides statistical data obtained from a proof of concept test on three (3) groups as described above. The data show a median value of 21.2 U/l for the group histologically determined to have lymphoma, which is significantly higher than the median value of either the group affected by inflammatory bowel disease or the normal group. The statistical data of Table 1 are used to plot graph 300 of FIG. 3 .
[0046] FIG. 3 and Table 1 illustrate the significant difference of TK activity between the lymphoma-affected group on one hand, and the IBD-affected group or the normal group on the other hand. A cutoff of segregation between the two groups according to the above test may be established around 15.5 Units per liter of enzymatic activity. An cat showing activity levels of TK higher than 15.5 U/l has a high probability of having lymphoma.
[0047] FIG. 4 is a scatter plot of individual measurements obtained from a test study conducted in accordance with the teachings of the invention. Plot 400 represent measurement data obtained from three (3) groups (as described above), wherein one group 401 comprises cats that have been shown using a histological test to lymphoma, a second group 402 comprises cats that have been shown to have inflammatory bowel disease, and third group 403 , the normal group. The ordinate axis 430 represents TK activity level in Units per liter. Each data point 440 represents a separate subject, the measurement 440 may represent a single TK measurement or an average of more than one test from the same cat.
[0048] Thus, a method a system that allow a practitioner to detect a level of enzymatic activity of thymidine kinase in the blood of a cat, and determine a probability of presence of lymphoma in order to guide further diagnoses of the disease.
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The invention provides a method and a system for diagnosing lymphoma in cats. The system allows a care giver to measure the enzymatic activity of thymidine kinase in a blood sample. The invention teaches that when the enzymatic activity of thymidine kinase in the blood stream of a cat is above 15.5 Units per liter, the cat has a high probability of having lymphoma. The invention allows for initial diagnosis, follow up after treatment for lymphoma and/or monitoring for example in breeds that prone to have lymphoma.
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FIELD OF THE INVENTION
This invention relates to a decoder having error correcting functions for binary codes and more specifically to a decoder having correcting functions for random errors and burst errors in received binary codes.
BACKGROUND OF THE INVENTION
Binary codes transmitted through a transmission line are subject to being changed by various noise signals or disturbances causing random errors and/or burst errors before they are received and passed to a decoder. With a view to eliminating such errors from binary codes, various methods have already been proposed.
It is known that the Bose-Chandhuri-Hocquenghem Code (BCH) is one of the random error correcting codes. Relevant art may include "Error Correcting Codes" by W. W. Peterson, The M.I.T. Press, Cambridge, Mass., John Wiley, New York, 1961; "Algebraic Coding Theory" by E. R. Berlekamp, The M.I.T. Press, Cambridge, Mass. John Wiley, New York, 1968; and "A Method for Solving Key Equation for Decoding Goppa Codes" by Y. Sugiyama et al., Information and Control, Vol. 27, pp 87-99, 1975.
FIG. 1 is a block diagram of a cyclic error locating unit based on theory set forth in the above mentioned Peterson article. An error correction process of this cyclic error locating unit may be comprised in following three steps.
(a) A received vector r(X)=r 0 +r 1 X+r 2 X 2 + . . . +r n-1 X n-1 applied to an input terminal 1 is sent to a syndrome calculator 2 producing syndrome S=S 1 , S 2 , . . . , S 2t .
(b) Results of step a are sent to a logic circuit 3 in order to find an error location polynominal ฯ(X).
(c) Error location numbers ฮฒ i are determined by finding a root of ฯ(X).
The values ฯ 1 , ฯ 2 , . . . , ฯ t for testing error locations determined by such steps are respectively input to the ฯ registers R 1 , R 2 , . . . , R t of the cyclic error location unit 4. Contents of the registers are input to the Galois Field Arithmetic Units (GFAU) M 1 , M 2 , . . . , M t to be multiplied with root of ฯ(X). Results of these multiplications are returned to the respective registers. Each output of the register is sent to a logic circuit U A , which outputs "1" when the sum of them ##EQU1## is equal to 1, otherwise, "0". This output from the circuit U A is sent to one input of an adder 6. The other input of the adder 6 is connected to a delay buffer 5. The buffer 5 stores the received vector signal sent from the input terminal 1. The bit ฮณ n-1 from the buffer is added to an output of the circuit U A using the adder 6 to produce an error corrected signal, which is then sent to an output terminal 7.
On the other hand, the Fire code is known as a typical burst error correction code, where P(x) represents a known polynominal of m order, and e represents the least positive integer with X e +1 to be divisible. The Fire code for correcting a single burst error up to a length of l is generated by a following general polynominal.
g(x)=P(x)(1+X.sup.2e-1) (1)
Where lโฆm, and 2l-1 is not divisible by e. The paper by W. W. Peterson, entitled "Error-Correcting Codes", MIT Press, Cambridge, Mass., New York, 1961 teaches us that the code length n is given by LCM (e, 2l-1). The burst error correcting capability of the Fire code is equal to 2 l/(m+2l-1). The paper by S. Lin, entitled "An Introduction to Error Correcting-Codes," Englewood Cliffs, N.J., Prentice Hall, Inc. also teaches us that ฮท is approximately equal to 2/3, if l=m and mโโ.
When discussing burst error correcting capability, it is known that a limit of burst error correcting capability of (n, k, l) code (register's limit) exists, where l is burst error correcting capability, n is length, and k is a number of symbols in case of burst error correcting code. The code which satisfies l=(n-k)/2 is the most optimum value, where ฮท=1. This indicates that the Fire code is not effective at the register's limit.
Some of the effective cyclic and shortened cyclic codes for correcting single burst error are listed in the following table. There are also described in the above mentioned paper by S. Lin i.e. "An Introduction to Error-Correcting Codes"; pp 119-129.
TABLE______________________________________ CODE Burst error Generaln-k-2l (n, k) correcting capability polynomial______________________________________0 (7,3) 1 35 (15,9) 3 171 (15,11) 4 1151 (27,17) 5 2671 (34,22) 6 15173 (38,24) 7 114361 (50,34) 8 224531 (56,38) 9 1505773 (59,39) 10 40033511 (15,10) 2 65 (27,20) 3 311 (38,29) 4 1151 (48,37) 5 4501 (67,54) 6 36365 (103,88) 7 114361 (96,79) 8 5010017 (31,25) 2 161 (63,55) 3 711 (85,75) 4 2651 (131,119) 5 15163 (169,155) 6 557253 (63,56) 2 355 (121,112) 3 1411 (164,153) 4 6255 (290,277) 5 247114 (511,499) 4 104515 (1023,1010) 4 22365______________________________________ where, n = Code length k = Number of information digits
FIG. 2 is a block diagram of an error trapping decoder in connection with the theory described in the above mentioned Lin paper. In the first step, the transmitted information digits k coming from the input terminal 1 is passed to a modulo 2 adder 8 to be added with an output from a gate 11. An output from the adder is applied to a syndrome register 9 consisting of shift registers of (n-k) stages, and is also applied to a delay buffer register 5 of k stages. Where, k=5, n=15. In this step, the gate 11 is held in turned ON state, and gates 12 and 13 are held in turned OFF state.
In the second step, the weight bit outputs of register 9 are respectively input to a gate circuit 14 consisting a group of OR gates and its outputs are in turn applied to an all 0's check and control circuit 15. If outputs from circuit 14 are all 0's, the circuit 15 outputs "1", otherwise "0". The former means that the k received information digits in the buffer register 5 are error free. In this case, the gate 13 is turned ON and the k received information digits stored in the register 5 are sent to the output terminal 7 through the adder 5a and gate 13, while the gate 12 is held in turned OFF state.
If the output is in the latter case, the gate 11 is turned ON and the gates 12, 13 are held in turned OFF state and contents of the register 9 are shifted once to the left so that its output is fed back through the line 10.
With such operations, if the weight of the contents of the syndrome register 9 never goes down to 1 or less by the time the k received information digits have been read out of the buffer 5, then either an uncorrectable error pattern has occurred or correctable error pattern with errors not confined to n-k consecutive portion s has occurred.
Finally, the codes for correcting random and burst errors, such as the codes described in the paper entitled "Error-Correcting Code for a Compound Channel" by H. T. Hsu, T. Kasami and R. T. Chien, IEEE Trans. IT-14, No. 1, pp 135-138, 1968 are rather complicated and not effective.
OBJECTS OF THE INVENTION
It is an object of this invention to provide an error correcting decoder means for correcting code errors in received binary codes with high reliability.
It is another object of this invention to provide an error correcting decoder means for selecting an optimum error compensation arrangement in accordance with error pattern existing in received binary codes.
It is still other object of this invention to provide an error correcting decoder means for effectively compensating errors in received binary codes.
SUMMARY OF THE INVENTION
According to this invention, there are provided a first means for correcting random errors of received signal and a second means for correcting burst errors of received codes. There is concurrently executed a syndrome calculation check whether or not the output from the first means becomes all "0's", and the output of the first or second means is selectively gated to the output terminal in accordance with such check result.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conventional block diagram of a cyclic error locating unit based on Peterson's theory;
FIG. 2 is a conventional block diagram of an error trapping decoder in connection with the theory described in "Introduction to Error-Correcting Codes" by S. Lin;
FIG. 3 is a general block diagram of the decoder embodying the present invention,
FIG. 4 shows detailed structure of the corrector shown in FIG. 3 capable of correcting errors in the BCH codes up to the double errors;
FIG. 5 shows detailed structure of the detector and selector shown in FIG. 3;
FIG. 6 is a block diagram of a second embodiment of the present invention; and
FIG. 7 shows the time chart of the operation mode of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 3 is a general block diagram of the decoder embodying the present invention. A bit stream of BCH codes to be error-corrected is received through the input terminal 1 to be passed to a random error corrector 16 and a burst error corrector 17 and error-corrected therein before it is output. The output thus error-corrected by the corrector 16 is passed to a mode decision circuit 18 and one input of an output selector 19 which is simulated with a switch from its function. The other input of the selector 19 is supplied with the error-corrected BCH codes from the corrector 17. Selector 19 selects the output from the corrector 16 or 17 in accordance with the control of the circuit 18 and then sends it out via the output terminal 7.
FIG. 4 shows detail structure of the corrector 16 which is capable of correcting errors in the BCH codes up to double errors. The BCH codes or received vector coming via the terminal 1, which is expressed, for example, as
g(x)=1+x+x.sup.2 +x.sup.4 +x.sup.5 +x.sup.8 +x.sup.10,
is provided to syndrome registers 20 and 22 of the syndrome calculator 2, and to the delay buffer 5. The calculator 2 comprises also Galois field arithmetic units 21 and 23, and it performs following operations for the received vector. ##EQU2##
Here, since it is required only to correct up to double errors, the required operation is executed for S 1 -S 4 in above calculations. There are also relations, S 2 =S 1 2 , S 4 =S 2 2 , and S 6 =S 3 2 so that it is no longer necessary to calculate the syndrome of even suffix in the case of 2-element BCH codes. More practically speaking, the syndrome S is available by shifting one in the ith operation before multiplying with the element ฮฑ of the unit 21 and adds such result to the total value of the preceding operation, namely, (i-1)th operation and then stores it in the register 20. Such operation is repeated for n-1 times. The similar operations is also carried out by using the register 22 and unit 23 for the syndrome S 3 .
The syndrome S 1 is then transferred to a known third power circuit 24 and it is cubed to produce S 1 3 . The circuit 24 may preferably be arranged by using the technique disclosed in the paper by Yamagishi and Imai entitled, "A method of Forming a Decoder for BCH Codes Using ROM", Articles of Electronics and Communication Society of Japan, Vol., J63-D, No. 12, pp 1034-1041.
The S 1 3 from the circuit 24 and S 3 from the register 22 are applied to a coincidence detector 24, which has an output made active when S 1 3 =S 3 and applied to a timing circuit 26. The circuit 26 holds its input signal before providing it at the timing position of S 1 =ฮฑ.
The syndrome S 1 is also applied to an error location logic 3 together with the syndrome S 3 sent from the register 22 which executes the following calculating function.
ฯ(x)=(1+ฮฒ.sub.1 x)(1+ฮฒ.sub.2 x)
ฯ.sub.0 +ฯ.sub.1 x+ฯ.sub.2 x.sup.2
where, ฯ 0 =1, ฯ 1 =ฮฒ 1 +ฮฒ 2 , ฯ 2 =ฮฒ 1 ฮฒ 2 . Roots of ฯ(x) are expressed by ฮฒ 1 -1 , ฮฒ 2 -1 of inverse number of error location. According to the Newton's identity,
S.sub.1 -ฯ.sub.1 =0
S.sub.3 -ฯ.sub.1 S.sub.2 +ฯ.sub.2 S.sub.1 =0.
Therefore, the answer can be obtained easily as indicated below.
ฯ.sub.1 =S.sub.1
ฯ.sub.2 =S.sub.1.sup.2 +(S.sub.3 /S.sub.1)
The values ฯ 1 , ฯ 2 thus obtained are input to a known cyclic error correcting circuit 4, such as an arrangement disclosed by R. T. Chien in "Cyclic Decoding Procedure for the Bose-Chandhuri-Hocquenghem Code" IEEE Trans. on Information Theory, IT-10, pp 357-363, Oct. 1964, and explained in relation to FIG. 1. Referring now to FIG. 1, t stage ฯ registers R 1 , R 2 , . . . , R t store the values ฯ 1 , ฯ 2 , . . . , ฯ t calculated in the 2nd step of decoder. Where, ฯ.sub.ฮฝ+1 =ฯ.sub.ฮฝ+2 = . . . ฯ t =0, ฮฝ<t. The t GFAU units M 1 , M 2 , . . . , M t perform the multiplication once. Thereafter, ฮฝ n-1 is read from the buffer. When a series of multiplications is carried out, ฯ 1 ฮฑ, ฯ 2 ฮฑ 2 , . . . , ฯ.sub.ฮฝ ฮฑ.sup.ฮฝ are respectively stored in the registers R 1 , R 2 , . . . , R t . The circuit U A carries out the calculation of ##EQU3## and if its result is equal to 1, an output becomes "1". Upon referring again to FIG. 4, the output from the circuit 4 is provided to a timing circuit 27.
The received codes or received words from the input terminal 1 are also provided to the delay circuit 5 to be delayed by a time corresponding to a delay time accumulated down to the circuit 4 and then to modulo two adders 28 and 29. Other input of the adders 28 and 29 are respectively connected to an output of timing circuits 27 and 26. The adder 29 adds a single error location ฮฑ i from the circuit 26 to an information from the buffer 5 in the polarity such that its error can be corrected and then supplies the resultant signal to one input of OR gate 30. On the other hand, the adder 28 adds the locations ฮฑ i and ฮฑ j from the circuit 27 to an output from the circuit 5 with the polarity such that its double errors can be corrected and resultant outputs are supplied to the other input of the OR gate 30.
It should be noted that when the Hamming distance d is equal to 7, triple or quadruple errors can also be corrected, and the syndrome which is not used in the instance described above may also be used in order to correct such errors.
An output from the OR gate 30 is supplied to the mode decision circuit 18 and selector 19 as explained in connection with FIG. 3.
FIG. 5 shows detailed structure of the mode decision circuit 18 and selector 19. An output from the corrector 16 is supplied to the respective one input of syndrome registers (S 5 ) 31 and (S 6 ) 33 in the mode decision circuit 18. Since the signals ฮฑ 5 and ฮฑ 6 from Galois field units 32 and 34 are supplied to the other input of the registers 31 and 33, the calculations indicated below are executed by the same operations as explained in the calculator 2 of FIG. 1. ##EQU4##
Thereafter, the results are respectively input to zero detectors 35 and 36.
When a single (or double) error exists in the received vector, the values of S 5 and S 6 are corrected by the corrector 16 and therefore these are respectively set to zero. Such zero output is detected by the detectors 35 and 36, which make the output active and supply such output to the selector 19 through an OR gate 37.
The corrector 17 may have the known structure, such as shown in FIG. 2 and if triple or more high grade errors exist in the received vector, namely when at least either one of the S 5 , S 6 is not zero, its output is selected by the selector 19 as will be described later.
Since there is a relation of S 6 =S 3 2 , a value of S 6 may be calculated by squaring an output value of the corrector 16. A means for performing such calculation may be attained by the prior art as described in relation to the circuit 24.
In case an error trapping decoder as shown in FIG. 2 is used for correcting burst errors of BCH codes, burst errors up to a burst length b=5 can be corrected. In this case, n=15, k=5, d=7 and the feedback connection g(x)=1+x+x 2 +x 4 +x 5 +x 8 +x 10 . Therefore, it is obvious that boundary of the register can be satisfied with the equal sign.
As shown in FIG. 5, the circuit 18 supplies an input signal to one input of an AND gate 40 and via inverter 38 to an AND gate 39. The other input of the AND gate 40 is supplied from the corrector 17. The other input of the AND gate 39 is connected to the output of the corrector 16. The outputs from AND gates 39 and 40 are passed to the output terminal 7 through an OR gate 41. For example, if an output of mode decision circuit 18 is zero, the AND gate 39 is kept open and the AND gate 40 is blocked so that an output of corrector 16 is gated to the output terminal 7 through the OR gate 41. If the output of the detector 18 becomes "1", the AND gate 39 is blocked, while the AND gate 40 is kept open so that the output from the corrector 17 is gated to the terminal 7 through the OR gate 41.
FIG. 6 is a block diagram of a second embodiment of present invention. The elements which are the same as those in FIG. 3 are given the same reference numbers and some elements which are duplicated are distinguished by a suffix letter. A switch 71 is provided for selecting an output between random error correctors 16a and 16b. A switch 72 is also provided for selecting an output between burst error correctors 17a and 17b. In addition, a counter 42 which counts a number of outputs of the mode decision circuit 18 is provided and a switch 73 is provided for selecting output between the outputs of the circuit 18 and counter 42, both forming a monitor 43. A switch control 44 is also provided to make the switch positions of selectors 19, 71-73 to be changed periodically in synchronization with an input signal as shown in FIG. 7.
At the initial condition or monitor mode of operation, the selectors 71, 72, 73 respectively select the outputs of the correctors 16b, 17a and circuit 18, and the selector 19 selects an output of the selector 71 such that an output of the corrector 16b is led to the terminal 7. The mode decision circuit 18 of the monitor 43, when detecting a multiple of t+1 order or higher errors in the monitor mode, generates a control signal so that the selector 19 is switched to select an output of selector 72. Therefore, an output from the corrector 17a is passed to the terminal 7 through the selectors 72 and 19.
When a multiple of t order or less errors is detected, the control signal from the mode decision circuit 18 of the monitor 43 is passed to the selector 19 through the selector 73 so that the selector 19 is set to the location as shown in the FIG. 3. Thereby an output of the corrector 16b is led to the terminal 7 through the selectors 71 and 19.
The counter 42 counts up the number of output operations of the corrector caused by random errors of t+1 multiple order or higher being detected within the monitor time period (N m รT). When this count value exceeds a specified value, such as N m /2, an input vector is decided to have burst errors. When it does not exceed such value, the input vector is decided to have random errors. Thereafter the monitor mode is concluded by the switch control 44 operating the output selector 73 to select the output of the counter 42. In the following period of normal operation, the selector 19 is connected to the selector 72, if the burst error correction mode is selected by the counter 42, while the selector 19 is connected to the selector 71 if the random error correction mode is selected by the counter 42. Also, the switches 71 and 72 are respectively connected to the correctors 16a and 17b by the control of switch control 44.
In the normal operation period, the corrector 16a or 17b performs correction with the maximum correcting capability of the code thereof. Thereafter, the monitor mode appears again and checks the incoming code condition in order to prepare for the next operation period.
FIG. 7 shows the time chart of the operation mode of FIG. 6. When a time interval required to complete one code word input is indicated by T, the monitor mode continues for the period N m รT. Thereafter, the random or burst mode continues for the period N s รT. Where N m is the suitable time period required for deciding whether the incoming codes have random errors or burst errors, while N s is the time which is long enough during which the input vector condition may not be changed significantly. As shown in the figure, the monitor mode and normal mode are interleaved alternatively because the receiving condition of the input vector sometimes changes as the time goes by. For this reason, the normal mode is interrupted by the monitor mode in order to adapt to its receiving condition such that the system may take the most favorable correction mode.
Explained above is the technique for correcting ฮด random errors satisfying the relation, where ฮด<t when the error correction capability is considered as t. However, if the complete codes are not available, it does not always guarantee to provide the code vector whatever errors of t order may be included therein. In such a case, such modification may be taken that the syndrome check of the present invention is carried out before the error correction mode of the device is switched from the random correction mode to the burst correction mode.
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
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A decoder wherein the received codes consisting of a plurality of binary bits are sent to the first and second corrector which are operating in parallel in order to correct random and burst errors respectively. An error-corrected output of the former is further determined whether it becomes all zeros or not by the syndrome calculation. If the result is affirmative, an output of the first corrector, otherwise an output of the second corrector is selected to be sent to the output terminal.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of Korean Patent Application No. 10-2012-0062652 filed on Jun. 12, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a lens module for a camera, and more particularly, to a lens module capable of realizing a high-resolution performance and a bright optical system.
[0004] 2. Description of the Related Art
[0005] Recent mobile communications terminals have a camera provided therewith, allowing for video communications and photography. In addition, as the functionality of cameras included in mobile terminals has gradually increased, cameras for a mobile terminal have gradually been required to have high resolution and high functionality.
[0006] However, there is a trend for mobile terminals to be smaller and a lighter weight, and thus, there may be a limit in realizing a highly-functional camera having high-resolution.
[0007] In order to solve these limits, recently, the lens of the camera has been formed of plastic having a lighter weight than glass, and 4 or more lenses constituting a lens module have been provided to realize high resolution.
[0008] However, an improvement of chromatic aberration is more difficult in a lens made of plastic than in a lens made of glass, and also, it is difficult to realize a relatively bright optical system in the plastic lens as compared to the glass lens.
[0009] Meanwhile, Patent Documents 1 and 2 disclose lens modules for realizing a high-resolution camera in the related art.
(Patent Document 1) KR2012-018573 A (Patent Document 2) KR2007-097369 A
SUMMARY OF THE INVENTION
[0012] An aspect of the present invention provides a lens module capable of realizing a high-resolution performance and a bright optical system.
[0013] According to an aspect of the present invention, there is provided a lens module, including: a first lens having positive refractive power, an object-sided surface thereof being convex; a second lens having negative refractive power, an image-sided surface thereof being concave; a third lens having positive refractive power; a fourth lens having negative refractive power, an image-sided surface thereof being convex; and a fifth lens having negative refractive power, an image-sided surface thereof being concave, wherein the fourth lens satisfies Conditional Expression 1,
[0000]
f
๎ข
๎ข
4
f
<
-
3.0
[
Conditional
๎ข
๎ข
Expression
๎ข
๎ข
1
]
[0014] where f is an overall focal distance of an optical system and f4 is a focal distance of the fourth lens.
[0015] The first lens and the fourth lens may satisfy Conditional Expression 2,
[0000] 20<ฮฝ 1 โฮฝ 4 <40โโ[Conditional Expression 2]
[0000] where โช1 is an abbe number of the first lens, and โช4 is an abbe number of the fourth lens.
[0016] The first lens and the fourth lens may satisfy Conditional Expression 3,
[0000]
f
๎ข
๎ข
4
f
๎ข
๎ข
1
<
-
5.0
[
Conditional
๎ข
๎ข
Expression
๎ข
๎ข
3
]
[0017] where f1 is a focal distance of the first lens, and f4 is the focal distance of the fourth lens.
[0018] The lens module may satisfy Conditional Expression 4,
[0000]
0.5
<
TL
f
<
2.0
[
Conditional
๎ข
๎ข
Expression
๎ข
๎ข
4
]
[0019] where TL is a distance from the object-sided surface of the first lens to an upper surface of an image sensor, and f is the overall focal distance of the optical system.
[0020] The third lens may have a convex image-sided surface.
[0021] The fourth lens may have a meniscus shape.
[0022] The fifth lens may have at least one inflection point formed on the image-sided surface thereof.
[0023] According to another aspect of the present invention, there is provided a lens module, including: a first lens having positive refractive power, an object-sided surface thereof being convex; a second lens having negative refractive power, an image-sided surface thereof being concave; a third lens having a meniscus shape convex toward an image; a fourth lens having negative refractive power, an image-sided surface thereof being convex; and a fifth lens having negative refractive power, an image-sided surface thereof being concave,
[0024] wherein the fourth lens satisfies Conditional Expression 1,
[0000]
f
๎ข
๎ข
4
f
<
-
3.0
[
Conditional
๎ข
๎ข
Expression
๎ข
๎ข
1
]
[0025] where f is an overall focal distance of an optical system and f4 is a focal distance of the fourth lens.
[0026] The first lens and the fourth lens may satisfy Conditional Expression 2,
[0000] 20<ฮฝ 1 โฮฝ 4 <40โโ[Conditional Expression 2]
[0027] where โช1 is an abbe number of the first lens, and โช4 is an abbe number of the fourth lens.
[0028] The first lens and the fourth lens may satisfy Conditional Expression 3,
[0000]
f
๎ข
๎ข
4
f
๎ข
๎ข
1
<
-
5.0
[
Conditional
๎ข
๎ข
Expression
๎ข
๎ข
3
]
[0029] where f1 is a focal distance of the first lens, and f4 is the focal distance of the fourth lens.
[0030] The lens module may satisfy Conditional Expression 4,
[0000]
0.5
<
TL
f
<
2.0
[
Conditional
๎ข
๎ข
Expression
๎ข
๎ข
4
]
[0031] where TL is a distance from the object-sided surface of the first lens to an upper surface of an image sensor, and f is the overall focal distance of the optical system.
[0032] The third lens may be convex toward the image.
[0033] The fifth lens may have at least one inflection point formed on at least one of an object-sided surface and the image-sided surface thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0035] FIG. 1 is a structural view of a lens module according to a first embodiment of the present invention;
[0036] FIG. 2 is a graph showing aberration characteristics of the lens module of FIG. 1 ;
[0037] FIG. 3 is a structural view of a lens module according to a second embodiment of the present invention;
[0038] FIG. 4 is a graph showing aberration characteristics of the lens module of FIG. 3 ;
[0039] FIG. 5 is a structural view of a lens module according to a third embodiment of the present invention;
[0040] FIG. 6 is a graph showing aberration characteristics of the lens module of FIG. 5 ;
[0041] FIG. 7 is a structural view of a lens module according to a fourth embodiment of the present invention;
[0042] FIG. 8 is a graph showing aberration characteristics of the lens module of FIG. 7 ;
[0043] FIG. 9 is a structural view of a lens module according to a fifth embodiment of the present invention; and
[0044] FIG. 10 is a graph showing aberration characteristics of the lens module of FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
[0045] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0046] In describing the present invention below, terms indicating components of the present invention are named in consideration of functions thereof. Therefore, the terms should not be understood as limiting technical components of the present invention.
[0047] For reference, it is to be noted that, in the present specification, the term โfrontโ refers to a direction toward an object from a lens module, while the term โrearโ refers to a direction toward an image sensor from a lens module. In addition, it is to be noted that, in each lens, a first surface refers to a surface toward an object and a second surface refers to a surface adjacent to an image.
[0048] FIG. 1 is a structural view of a lens module according to a first embodiment of the present invention; FIG. 2 is a graph showing aberration characteristics of the lens module of FIG. 1 ; FIG. 3 is a structural view of a lens module according to a second embodiment of the present invention; FIG. 4 is a graph showing aberration characteristics of the lens module of FIG. 3 ; FIG. 5 is a structural view of a lens module according to a third embodiment of the present invention; FIG. 6 is a graph showing aberration characteristics of the lens module of FIG. 5 ; FIG. 7 is a structural view of a lens module according to a fourth embodiment of the present invention; FIG. 8 is a graph showing aberration characteristics of the lens module of FIG. 7 ; FIG. 9 is a structural view of a lens module according to a fifth embodiment of the present invention; and FIG. 10 is a graph showing aberration characteristics of the lens module of FIG. 9 .
[0049] A lens module 100 according to the present invention may include a first lens 10 , a second lens 20 , a third lens 30 , a fourth lens 40 , and a fifth lens 50 , and may selectively further include an aperture and a filter member 60 , and an image sensor 70 . The first lens 10 to the fifth lens 50 may be sequentially disposed from an object (that is, a subject or an object to be photographed) toward an image (that is, the image sensor).
[0050] The first lens 10 , the second lens 20 , the third lens 30 , the fourth lens 40 , and the fifth lens 50 may be all formed of plastic. As such, when all the lenses 10 , 20 , 30 , 40 and 50 are formed of plastic, the manufacturing cost of the lens module 100 may be reduced and the lens modules 100 may be conveniently mass-produced. In addition, when the lenses 10 , 20 , 30 , 40 , and 50 are formed of plastic, first and second surfaces S1, S2, S3, S4, S5, S6, S7, S8, S9, and S10 of the lenses are easily processed, and thus, the surfaces of the lenses may be formed to have a spherical or aspherical shape.
[0051] In the lens module 100 , the first lens 10 may be disposed closest to the object.
[0052] The first lens 10 may have positive refractive power overall. In addition, the first surface S1 of the first lens 10 may be convex toward the object, and the second surface S2 thereof may be convex toward the image. In detail, the first surface S1 may be more convex than the second surface S2.
[0053] At least one of the first surface S1 and the second surface S2 of the first lens 10 may be aspherical. However, as needed, both of the first surface S1 and the second surface S2 of the first lens 10 may be aspherical.
[0054] The second lens 20 may be disposed in the rear of the first lens 10 (that is, in the direction toward the image). The second lens 20 may have negative refractive power overall, and may be formed of plastic in like manner to the first lens 10 .
[0055] The first surface S3 of the second lens 20 may be convex toward the object, and the second surface S4 thereof may be concave toward the object. In addition, the second lens 20 may have at least one aspherical surface. For example, at least one of the first surface S3 and the second surface S4 of the second lens 20 may be aspherical. However, as needed, both of the first surface S3 and the second surface S4 of the second lens 20 may be aspherical.
[0056] The second lens 20 may have an abbe number satisfying Mathematical Expression 1 below.
[0000] ฮฝ2<40โโ[Mathematical Expression 1]
[0057] Here, โช2 is the abbe number of the second lens.
[0058] As such, when the abbe number of the second lens 20 is below 40, chromatic aberration caused by the first lens 10 may be effectively corrected. When the abbe number of the second lens 20 is above 40, a difference between an abbe number of the first lens 10 and the abbe number of the second lens 20 may be reduced (In general, the abbe number of the first lens 10 is between 50 and 60), such that a chromatic aberration correction effect through the second lens 20 may be deteriorated. Therefore, the second lens 20 may be manufactured in such a manner that the abbe number thereof is below 40, as supposed in Mathematical Expression 1. The abbe number of the second lens 20 may be 20 to 30.
[0059] The third lens 30 may be disposed in the rear of the second lens 20 . The third lens 30 may have positive refractive power overall, and may be formed of plastic. However, as needed, the third lens 30 may have negative refractive power.
[0060] The first surface S5 of the third lens 30 may be concave, and the second surface S6 thereof may be convex toward the image. Here, in some cases, the first surface S5 of the third lens 30 may be convex toward the object (please refer to the third embodiment of the present invention shown in FIG. 5 ).
[0061] Meanwhile, the second lens 20 and the third lens 30 as described above may satisfy Mathematical Expression 2.
[0000]
-
3.0
<
f
๎ข
๎ข
3
f
๎ข
๎ข
2
<
-
0.3
[
Mathematical
๎ข
๎ข
Expression
๎ข
๎ข
2
]
[0062] Here, f2 is a focal distance of the second lens 20 and f3 is a focal distance of the third lens 30 .
[0063] In the lens module, if a value of f3/f2 is below the lower limit according to Mathematical Expression 2, the refractive power of the second lens may be increased, and thus, it may be difficult to manufacture the second lens. In the same manner, in the lens module, if the value of f3/f2 is above the upper limit according to Mathematical Expression 2, the refractive power of the third lens may be increased, and thus, it may be difficult to manufacture the third lens.
[0064] Therefore, it is desirable to satisfy conditions for Mathematical Expression 2 to allow for mass-production of the lens module.
[0065] The fourth lens 40 may be disposed in the rear of the third lens 30 . The fourth lens 40 may have negative refractive power, and may be formed of plastic.
[0066] The first surface S7 of the fourth lens 40 may be concave, and the second surface S8 thereof may be convex toward the image. In addition, the fourth lens 40 may have a meniscus shape, convex toward the image, overall.
[0067] The fourth lens 40 may satisfy Mathematical Expressions 3 to 5.
[0000] 20<ฮฝ1โฮฝ4<40โโ[Mathematical Expression 3]
[0068] Here, โช1 is the abbe number of the first lens, and โช4 is an abbe number of the fourth lens.
[0069] Mathematical Expression 3 may be a limitation condition with respect to chromatic aberration of the lens module. That is, when a lens module satisfying Mathematical Expression 3 is manufactured, the chromatic aberration correction effect may be improved through the first lens 10 and the fourth lens 40 . However, if a value of โช1โโช4 is below the lower limit according to Mathematical Expression 3, a lens of glass needs to be used, and thus, unit costs for manufacturing the lens module 100 may be increased. Unlike this, if the value of โช1โโช4 is above the upper limit according to Mathematical Expression 3, the chromatic aberration correction effect may be deteriorated, and thus, it may be difficult to manufacture a lens module capable of realizing high resolution.
[0000]
f
๎ข
๎ข
4
f
๎ข
๎ข
1
<
-
5.0
[
Mathematical
๎ข
๎ข
Expression
๎ข
๎ข
4
]
[0070] Here, f1 is a focal distance of the first lens, and f4 is a focal distance of the fourth lens.
[0071] Mathematical Expression 4 may be a limitation condition for limiting the refractive power of the fourth lens 40 . That is, if a value of f4/f1 is above the upper limit according to Mathematical Expression 4, the refractive power of the fourth lens 40 in the lens module may be increased, and thus, resolution of the lens module 100 may be deteriorated or an overall length of the lens module 100 (that is, an overall length of the optical system) may be increased.
[0000]
f
๎ข
๎ข
4
f
<
-
3.0
[
Mathematical
๎ข
๎ข
Expression
๎ข
๎ข
5
]
[0072] Here, f is an overall focal distance of the lens module, and f4 is the focal distance of the fourth lens.
[0073] Mathematical Expression 5 may be a limitation condition for limiting the refractive power of the fourth lens 40 , like Mathematical Expression 4. That is, if a value of f4/f is above the upper limit according to Mathematical Expression 5, the (negative) refractive power of the fourth lens 40 in the lens module may be increased, and thus, resolution of the lens module 100 may be deteriorated or the overall focal distance of the lens module may become excessively small, so that distortion correction may be difficult (or a viewing angle of the lens module may be excessively large, and thus, a distortion phenomenon may occur).
[0074] Therefore, Mathematical Expression 4 and Mathematical Expression 5 all may need to be satisfied in order to decrease the overall length of the lens module 100 .
[0075] The fifth lens 50 may be disposed in the rear of the fourth lens 40 . The fifth lens 50 may have negative refractive power, and may be formed of plastic.
[0076] The first surface S9 of the fifth lens 50 may be convex toward the object at an intersection thereof with an optical axis (C-C) and may be concave at a peripheral portion thereof based on the optical axis (C-C). In addition, the second surface S10 of the fifth lens 50 may be concave at an intersection thereof with the optical axis (C-C) and may be convex at a peripheral portion thereof based on the optical axis (C-C). That is, at least one inflection point may be formed on the first surface S9 and the second surface S10 of the fifth lens 50 .
[0077] The filter member 60 may be disposed in the rear of the fifth lens 50 . Both surfaces of the filter member 60 may flat planes, and may be formed of a material other than plastic. For example, the filter member 60 may be formed of glass.
[0078] The filter member 60 may block infrared light. To achieve this, an IR blocking film may be attached to, or an IR blocking layer may be coated on, at least one surface of the filter member 60 . Meanwhile, the filter member 60 may be omitted, depending on the type of the lens module 100 .
[0079] The image sensor 70 may be disposed in the rear of the filter member 60 .
[0080] The image sensor 70 may convert an image of the object, incident through the lenses 10 , 20 , 30 , 40 , and 50 into an electric signal. A charge-coupled device (CCD), complementary metal-oxide-semiconductor (CMOS), or the like, may be used for the image sensor 70 , and the image sensor 70 may be manufactured in the form of chip scale package (CSP).
[0081] The aperture (not shown) may be disposed in front of the first lens 10 or between the first lens 10 and the second lens 20 . However, the aperture may be omitted as needed.
[0082] The lens module 100 as described above may satisfy Mathematical Expression 6.
[0000]
0.5
<
TL
f
<
2.0
[
Mathematical
๎ข
๎ข
Expression
๎ข
๎ข
6
]
[0083] Here, TL is an overall length of the optical system (a length from the first surface S1 of the first lens to an upper surface of the image sensor 70 ), and f is the overall focal distance of the optical system.
[0084] Mathematical Expression 6 may be a numerical value for limiting the viewing angle and the length of the lens module. That is, if a value of TL/f is below the lower limit according to Mathematical Expression 6, it may be difficult to obtain the viewing angle of the lens module 100 . On the contrary, if the value of TL/f is above the upper limit according to Mathematical Expression 6, the length (that is, TL) of the lens module 100 is extended, and thus, it is difficult to manufacture the lens module 100 so as to have a small size.
[0085] Meanwhile, at least one surface of the first lens 10 to the fourth lens 40 may be aspherical. Aspherical coefficients of the lenses may be calculated by using Mathematical Expression 7.
[0000]
๎ข
[
Mathematical
๎ข
๎ข
Expression
๎ข
๎ข
7
]
z
=
c
๎ข
๎ข
h
2
1
+
SQRT
๎ข
{
1
-
(
1
+
k
)
๎ข
c
2
๎ข
h
2
}
+
A
๎ข
๎ข
h
4
+
B
๎ข
๎ข
h
6
+
C
๎ข
๎ข
h
8
+
D
๎ข
๎ข
h
10
+
E
๎ข
๎ข
h
12
+
F
๎ข
๎ข
h
14
[0086] Here, c is curvature (1/radius of curvature), h is a radius from the center to a specific position in the lens, K is a conic coefficient, A is a 4 th -order coefficient, B is a 6 th -order coefficient, C is an 8 th -order coefficient, D is a 10 th -order coefficient, E is an 12 th -order coefficient, F is a 14 th -order coefficient, and Z is sag at the specific position.
[0087] For reference, K, A, B, C, D, E, and F values for respective embodiments are shown in Tables 2, 4, 6, 8, and 10.
[0088] The lens module 100 as constructed above may realize high resolution through numerical limitations according to Mathematical Expressions 1 to 5, and may be miniaturized.
[0089] In addition, the lens module 100 may improve brightness of the lens module 100 by limiting the focal distance of the fourth lens 40 through Mathematical Expressions 4 and 5.
[0090] Tables 1 to 10 below show numeral values in several embodiments of the lens module 100 having the above construction.
FIRST EMBODIMENT
[0091] The lens module 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2 .
[0092] The lens module 100 according to the first embodiment may include the first lens 10 having positive refractive power, the second lens 20 having negative refractive power, the third lens 30 having positive refractive power, the fourth lens 40 having negative refractive power, and the fifth lens 50 having negative refractive power.
[0000]
TABLE 1
Surface
Radius of
Thickness or
Refractive
Abbe
No.
Curvature
Distance
Index
No. (v)
S1
1.381
0.63
1.544
56.1
S2
8.924
0.09
S3
4.656
0.30
1.632
23.4
S4
1.988
0.37
S5
โ6.107
0.37
1.544
56.1
S6
โ2.683
0.42
S7
โ1.294
0.44
1.635
24
S8
โ1.591
0.10
S9
2.674
0.86
1.544
56.1
S10
1.684
0.18
S11
Infinity
0.30
1.517
64.2
S12
Infinity
0.71
img
Infinity
[0093] In the lens module 100 of the present embodiment, the focal distance f1 of the first lens 10 is 2.91 mm; the focal distance f2 of the second lens 20 is โ5.68 mm; the focal distance f3 of the third lens 30 is 8.44 mm; the focal distance f4 of the fourth lens 40 is โ25.61 mm; the focal distance f5 of the fifth lens 50 is โ12.01 mm; the overall focal distance f is 4.12 mm; and F number (F No.) is 2.40. Meanwhile, TL according to the embodiment is 4.77 mm, the smallest among the accompanying embodiments, together with Embodiment 2.
[0000]
TABLE 2
Surface
No.
K
A
B
C
D
E
F
S1
โ1.857Eโ01
8.822Eโ03
2.769Eโ02
โ5.482Eโ02
6.735Eโ02
โ2.650Eโ03
โ3.576Eโ02
S2
0.000E+00
โ1.533Eโ01
3.258Eโ01
โ4.407Eโ01
3.643Eโ01
โ1.995Eโ01
0.000E+00
S3
0.000E+00
โ2.557Eโ01
4.932Eโ01
โ5.532Eโ01
3.437Eโ01
โ1.596Eโ01
0.000E+00
S4
3.390E+00
โ1.678Eโ01
2.501Eโ01
โ1.168Eโ01
โ1.009Eโ01
7.702Eโ02
0.000E+00
S5
0.000E+00
โ1.242Eโ01
3.027Eโ02
5.238Eโ02
1.532Eโ01
โ1.558Eโ01
โ3.302Eโ02
S6
0.000E+00
โ4.577Eโ02
โ2.435Eโ02
9.005Eโ02
8.243Eโ02
โ1.060Eโ01
1.767Eโ02
S7
โ7.750E+00
โ1.172Eโ01
2.440Eโ02
3.182Eโ02
1.992Eโ02
โ4.579Eโ02
1.490Eโ02
S8
โ7.074E+00
โ1.305Eโ01
6.054Eโ02
5.414Eโ03
โ6.086Eโ03
โ1.476Eโ03
6.415Eโ04
S9
โ1.756E+01
โ1.810Eโ01
8.834Eโ02
โ1.984Eโ02
2.252Eโ03
โ1.045Eโ04
0.000E+00
S10
โ8.176E+00
โ6.832Eโ02
1.848Eโ02
โ3.813Eโ03
4.408Eโ04
โ1.997Eโ05
0.000E+00
SECOND EMBODIMENT
[0094] The lens module 100 according to the second embodiment of the present invention will be described with reference to FIGS. 3 and 4 .
[0095] The lens module 100 according to the second embodiment may include the first lens 10 having positive refractive power, the second lens 20 having negative refractive power, the third lens 30 having positive refractive power, the fourth lens 40 having negative refractive power, and the fifth lens 50 having negative refractive power.
[0000]
TABLE 3
Surface
Radius of
Thickness or
Refractive
Abbe
No.
Curvature
Distance
Index
No. (v)
S1
1.406
0.65
1.544
56.1
S2
11.651
0.09
S3
4.624
0.28
1.632
23.4
S4
1.950
0.37
S5
โ6.459
0.33
1.544
56.1
S6
โ2.625
0.33
S7
โ1.220
0.44
1.635
24
S8
โ1.419
0.22
S9
3.379
0.85
1.544
56.1
S10
1.759
0.21
S11
Infinity
0.30
1.517
64.2
S12
Infinity
0.70
img
Infinity
[0096] In the lens module 100 of the present embodiment, the focal distance f1 of the first lens 10 is 2.86 mm; the focal distance f2 of the second lens 20 is โ5.50 mm; the focal distance f3 of the third lens 30 is 7.85 mm; the focal distance f4 of the fourth lens 40 is โ100.00 mm; the focal distance f5 of the fifth lens 50 is โ8.24 mm; the overall focal distance f is 4.12 mm; and F No. is 2.40. In addition, TL according to the embodiment is 4.77, the smallest, together with the first embodiment.
[0000]
TABLE 4
Surface
No.
K
A
B
C
D
E
F
S1
โ1.279Eโ01
5.285Eโ03
1.100Eโ02
โ2.319Eโ02
1.870Eโ02
1.418Eโ02
โ3.576Eโ02
S2
0.000E+00
โ1.403Eโ01
3.172Eโ01
โ4.893Eโ01
4.199Eโ01
โ2.180Eโ01
0.000E+00
S3
0.000E+00
โ2.361Eโ01
4.952Eโ01
โ5.972Eโ01
3.879Eโ01
โ1.596Eโ01
0.000E+00
S4
2.060E+00
โ1.456Eโ01
2.874Eโ01
โ1.720Eโ01
7.661Eโ03
7.702Eโ02
0.000E+00
S5
0.000E+00
โ1.194Eโ01
4.204Eโ02
โ3.706Eโ02
2.576Eโ01
โ1.654Eโ01
โ3.302Eโ02
S6
0.000E+00
โ3.044Eโ02
7.503Eโ03
โ1.392Eโ02
1.149Eโ01
โ3.098Eโ02
โ3.233Eโ02
S7
โ5.304E+00
โ8.453Eโ02
3.411Eโ02
โ1.067Eโ02
2.377Eโ02
โ2.645Eโ02
5.479Eโ03
S8
โ4.342E+00
โ7.572Eโ02
3.027Eโ02
9.316Eโ03
โ4.083Eโ03
โ2.132Eโ03
6.763Eโ04
S9
โ1.756E+01
โ1.537Eโ01
6.951Eโ02
โ1.396Eโ02
1.386Eโ03
โ5.457Eโ05
0.000E+00
S10
โ8.176E+00
โ6.808Eโ02
1.964Eโ02
โ4.242Eโ03
5.018Eโ04
โ2.250Eโ05
0.000E+00
THIRD EMBODIMENT
[0097] The lens module 100 according to the third embodiment of the present invention will be described with reference to FIGS. 5 and 6 .
[0098] The lens module 100 according to the third embodiment may include the first lens 10 having positive refractive power, the second lens 20 having negative refractive power, the third lens 30 having positive refractive power, the fourth lens 40 having negative refractive power, and the fifth lens 50 having negative refractive power.
[0099] Here, the first surface S5 of the third lens 30 may be convex toward the object, unlike the other embodiments. In addition, the fourth lens 40 may have an inflection point at a peripheral portion based on the optical axis (C-C) as shown in FIG. 5 .
[0000]
TABLE 5
Surface
Radius of
Thickness or
Refractive
Abbe
No.
Curvature
Distance
Index
No. (v)
S1
1.436
0.64
1.544
56.1
S2
6.630
0.08
S3
3.358
0.27
1.632
23.4
S4
1.706
0.45
S5
13.188
0.48
1.544
56.1
S6
โ3.790
0.22
S7
โ1.061
0.33
1.614
25.6
S8
โ1.207
0.28
S9
4.924
0.96
1.544
56.1
S10
1.883
0.17
S11
Infinity
0.30
1.517
64.2
S12
Infinity
0.70
img
Infinity
[0100] In the lens module 100 of the present embodiment, the focal distance f1 of the first lens 10 is 3.23 mm; the focal distance f2 of the second lens 20 is โ5.85 mm; the focal distance f3 of the third lens 30 is 5.46 mm; the focal distance f4 of the fourth lens 40 is โ100.00 mm; the focal distance f5 of the fifth lens 50 is โ6.31 mm; and the overall focal distance f is 4.16 mm. In addition, F No. of the present embodiment is 2.20, brighter than the first and second embodiments. However, TL according to the embodiment is 4.87, slightly larger than the first and second embodiments.
[0000]
TABLE 6
Surface
No.
K
A
B
C
D
E
F
S1
โ4.734Eโ02
1.039Eโ02
9.817Eโ03
1.128Eโ02
โ3.620Eโ03
3.154Eโ03
1.005Eโ02
S2
0.000E+00
โ1.480Eโ01
3.499Eโ01
โ4.657Eโ01
4.167Eโ01
โ1.825Eโ01
โ9.593Eโ11
S3
0.000E+00
โ2.849Eโ01
4.791Eโ01
โ5.550Eโ01
4.056Eโ01
โ1.943Eโ01
7.842Eโ11
S4
1.916E+00
โ1.879Eโ01
2.221Eโ01
โ1.494Eโ01
โ3.436Eโ02
3.671Eโ02
5.422Eโ11
S5
0.000E+00
โ5.424Eโ02
1.372Eโ02
โ1.117Eโ01
1.591Eโ01
โ7.781Eโ02
โ6.676Eโ03
S6
0.000E+00
2.355Eโ02
1.825Eโ02
โ9.312Eโ02
9.100Eโ02
โ3.215Eโ02
โ2.116Eโ03
S7
โ3.555E+00
3.317Eโ02
6.449Eโ02
โ2.497Eโ02
1.728Eโ02
โ2.030Eโ02
5.935Eโ03
S8
โ3.212E+00
โ3.105Eโ02
5.708Eโ02
1.093Eโ02
โ6.751Eโ03
โ3.138Eโ03
1.104Eโ03
S9
โ1.756E+01
โ1.831Eโ01
9.539Eโ02
โ3.645Eโ02
1.111Eโ02
โ1.950Eโ03
1.375Eโ04
S10
โ8.176E+00
โ7.204Eโ02
2.713Eโ02
โ8.822Eโ03
1.803Eโ03
โ2.120Eโ04
1.069Eโ05
Fourth Embodiment
[0101] The lens module 100 according to the fourth embodiment of the present invention will be described with reference to FIGS. 7 and 8 .
[0102] The lens module 100 according to the fourth embodiment may include the first lens 10 having positive refractive power, the second lens 20 having negative refractive power, the third lens 30 having positive refractive power, the fourth lens 40 having negative refractive power, and the fifth lens 50 having negative refractive power.
[0103] Here, the fourth lens 40 may have an inflection point at the peripheral portion thereof based the optical axis (C-C) like in the third embodiment.
[0000]
TABLE 7
Surface
Radius of
Thickness or
Refractive
Abbe
No.
Curvature
Distance
Index
No. (v)
S1
1.421
0.64
1.544
56.1
S2
4.647
0.08
S3
3.052
0.25
1.632
23.4
S4
1.803
0.49
S5
โ167.850
0.48
1.544
56.1
S6
โ2.394
0.16
S7
โ0.971
0.36
1.635
24
S8
โ1.128
0.43
S9
4.527
0.67
1.544
56.1
S10
1.673
0.21
S11
Infinity
0.30
1.517
64.2
S12
Infinity
0.81
img
Infinity
[0104] In the lens module 100 of the present embodiment, the focal distance f1 of the first lens 10 is 3.52 mm; the focal distance f2 of the second lens 20 is โ7.55 mm; the focal distance f3 of the third lens 30 is 4.46 mm; the focal distance f4 of the fourth lens 40 is โ95.01 mm; the focal distance f5 of the fifth lens 50 is โ5.32 mm; and the overall focal distance f is 4.21 mm. In addition, F No. and TL according to the embodiment are 2.20 and 4.87, respectively. F No. of the present embodiment is low, similarly to the case of the third embodiment, but TL according to the embodiment is slightly larger as compared with those of the first and second embodiments.
[0000]
TABLE 8
Surface
No.
K
A
B
C
D
E
F
S1
โ5.367Eโ02
8.025Eโ03
1.514Eโ02
3.207Eโ03
โ7.845Eโ03
1.837Eโ02
0.000E+00
S2
0.000E+00
โ1.984Eโ01
3.673Eโ01
โ4.480Eโ01
4.132Eโ01
โ1.994Eโ01
0.000E+00
S3
0.000E+00
โ3.320Eโ01
4.807Eโ01
โ4.276Eโ01
2.646Eโ01
โ1.515Eโ01
0.000E+00
S4
2.336E+00
โ1.899Eโ01
2.280Eโ01
โ8.781Eโ02
โ8.228Eโ02
3.671Eโ02
0.000E+00
S5
0.000E+00
โ7.394Eโ02
2.007Eโ02
โ1.709Eโ01
2.681Eโ01
โ1.298Eโ01
0.000E+00
S6
0.000E+00
5.194Eโ02
โ2.272Eโ02
โ4.804Eโ02
8.263Eโ02
โ3.874Eโ02
0.000E+00
S7
โ3.411E+00
4.881Eโ02
6.940Eโ02
โ3.097Eโ02
1.160Eโ02
โ2.132Eโ02
8.095Eโ03
S8
โ3.459E+00
โ1.721Eโ04
4.079Eโ02
4.433Eโ03
โ6.632Eโ03
โ2.549Eโ03
1.346Eโ03
S9
โ1.756E+01
โ1.367Eโ01
4.374Eโ02
โ6.467Eโ03
4.294Eโ04
โ7.727Eโ07
0.000E+00
S10
โ8.176E+00
โ6.509Eโ02
1.730Eโ02
โ3.737Eโ03
4.503Eโ04
โ3.085Eโ05
8.626Eโ07
Fifth Embodiment
[0105] The lens module 100 according to the fifth embodiment of the present invention will be described with reference to FIGS. 9 and 10 .
[0106] The lens module 100 according to the fifth embodiment may include the first lens 10 having positive refractive power, the second lens 20 having negative refractive power, the third lens 30 having positive refractive power, the fourth lens 40 having negative refractive power, and the fifth lens 50 having negative refractive power.
[0000]
TABLE 9
Surface
Radius of
Thickness or
Refractive
Abbe
No.
Curvature
Distance
Index
No. (v)
S1
1.637
0.72
1.544
56.1
S2
45.096
0.09
S3
4.687
0.30
1.632
23.4
S4
1.971
0.40
S5
โ20.922
0.43
1.544
56.1
S6
โ3.417
0.43
S7
โ1.297
0.41
1.635
24
S8
โ1.491
0.09
S9
3.226
0.98
1.544
56.1
S10
1.685
0.20
S11
Infinity
0.30
1.517
64.2
S12
Infinity
0.70
img
Infinity
[0107] In the lens module 100 of the present embodiment, the focal distance f1 of the first lens 10 is 3.09 mm; the focal distance f2 of the second lens 20 is โ5.56 mm; the focal distance f3 of the third lens 30 is 7.41 mm; the focal distance f4 of the fourth lens 40 is โ91.69 mm; the focal distance f5 of the fifth lens 50 is โ8.34 mm; and the overall focal distance f is 4.25 mm. In addition, F No. of the present embodiment is 2.20, brighter as compared with the first and second embodiments, but TL according to the embodiment is 5.05, the greatest among the accompanying embodiments.
[0000]
TABLE 10
Surface
No.
K
A
B
C
D
E
F
S1
โ3.596Eโ01
1.165Eโ03
7.459Eโ03
โ2.742Eโ02
1.868Eโ02
โ4.584Eโ03
โ7.427Eโ03
S2
0.000E+00
โ1.559Eโ01
3.396Eโ01
โ4.891Eโ01
3.692Eโ01
โ1.290Eโ01
0.000E+00
S3
0.000E+00
โ2.524Eโ01
5.538Eโ01
โ6.911Eโ01
5.115Eโ01
โ1.753Eโ01
0.000E+00
S4
1.265E+00
โ1.673Eโ01
3.220Eโ01
โ3.118Eโ01
2.376Eโ01
โ8.550Eโ02
0.000E+00
S5
0.000E+00
โ1.078Eโ01
3.365Eโ02
โ5.060Eโ03
1.153Eโ01
โ7.499Eโ02
8.252Eโ03
S6
0.000E+00
โ4.706Eโ02
โ2.680Eโ02
7.909Eโ02
โ3.231Eโ02
2.626Eโ02
โ1.321Eโ02
S7
โ7.540E+00
โ7.308Eโ02
1.782Eโ02
6.047Eโ03
1.635Eโ02
โ1.995Eโ02
4.378Eโ03
S8
โ6.736E+00
โ8.506Eโ02
2.676Eโ02
1.017Eโ02
โ2.270Eโ03
โ2.827Eโ03
7.803Eโ04
S9
โ1.756E+01
โ7.900Eโ01
3.000Eโ01
โ7.265Eโ02
1.000Eโ02
1.450Eโ03
0.000E+00
S10
โ8.176E+00
โ1.048E+00
7.922Eโ02
โ1.488Eโ02
7.258Eโ03
2.992Eโ04
0.000E+00
[0108] Table 11 shows main numerical values for the above-described embodiments.
[0109] All of the above-described embodiments 1 to 5 satisfy numerical limitations according to Mathematical Expressions 1 to 5, as shown in Table 11.
[0110] Here, the first and second embodiments may provide a relatively smaller TL than the other embodiments, while the third to fifth embodiments may provide a relatively brighter lens module than the other embodiments.
[0000]
TABLE 11
First
Second
Third
Fourth
Fifth
Embodi-
Embodi-
Embodi-
Embodi-
Embodi-
Note
ment
ment
ment
ment
ment
f
4.12
4.12
4.16
4.21
4.25
BFL
1.20
1.21
1.17
1.32
1.20
F No.
2.40
2.40
2.20
2.20
2.20
TL
4.77
4.77
4.87
4.87
5.05
FOV
70.00
70.20
70.40
69.70
69.10
f1
2.91
2.86
3.23
3.52
3.09
f2
โ5.68
โ5.50
โ5.85
โ7.55
โ5.56
f3
8.44
7.85
5.46
4.46
7.41
f4
โ25.61
โ100.00
โ100.00
โ95.01
โ91.69
f5
โ12.01
โ8.24
โ6.31
โ5.32
โ8.34
f4/f
โ6.22
โ24.27
โ24.04
โ22.57
โ21.57
v1-v4
32.10
32.10
30.50
32.10
32.10
f3/f2
โ1.49
โ1.43
โ0.93
โ0.59
โ1.33
f4/f1
โ8.82
โ34.95
โ30.98
โ27.01
โ29.66
TL/f
1.16
1.16
1.17
1.16
1.19
v2
23.40
23.40
23.40
23.40
23.40
[0111] As set forth above, the lens module capable of realizing a high-resolution camera and a bright optical system can be provided.
[0112] While the present invention has been shown and described in connection with the embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.
|
There is provided a lens module, including: a first lens having positive refractive power, an object-sided surface thereof being convex; a second lens having negative refractive power, an image-sided surface thereof being concave; a third lens having positive refractive power; a fourth lens having negative refractive power, an image-sided surface thereof being convex; and a fifth lens having negative refractive power, an image-sided surface thereof being concave, wherein the fourth lens satisfies Conditional Expression 1,
f
๎ข
๎ข
4
f
<
-
3.0
[
Conditional
๎ข
๎ข
Expression
๎ข
๎ข
1
]
where f is an overall focal distance of an optical system and f4 is a focal distance of the fourth lens.
| 6
|
TECHNICAL FIELD
[0001] The present invention is directed to a method of operation for a direct injection gasoline engine including a fuel vapor purge system, and more particularly to a method of controlling the engine combustion mode and fuel supply based on an estimate of the hydrocarbon concentration of the purge vapor.
BACKGROUND OF THE INVENTION
[0002] A direct injection gasoline engine may be operated in either homogeneous or stratified combustion modes, depending on the fuel injection timing relative to the engine cycle. In the homogeneous combustion mode, fuel is injected during the intake stroke of a four-stroke cycle so that the air/fuel mixture is evenly distributed throughout the cylinder when the mixture is ignited during the combustion stroke; while operating in this mode, a closed-loop control of fuel is executed to maintain the air/fuel ratio at a desired value, such as the stoichiometric ratio. In the stratified combustion mode, fuel is injected during the combustion stroke, resulting in a rich air/fuel mixture in the vicinity of the spark plug at ignition, even though the overall air/fuel ratio in the cylinder may be significantly leaner than the stoichiometric ratio; while operating in this mode, closed-loop fuel control is suspended, and an open-loop fuel control is executed instead.
[0003] Storage of fuel tank vapors is essential for the control of evaporative emissions, and in the usual system, the stored fuel vapor is periodically purged into the intake manifold of the engine for delivery into the engine cylinders along with the intake air. However, the purged fuel vapor may constitute a significant percentage of the overall fuel requirement, and the fuel injection quantity must be adjusted accordingly to maintain accurate control of the air/fuel ratio. When an engine is operated in a homogeneous combustion mode engine with closed-loop fuel control, the hydrocarbon concentration of the purge fuel vapor may be estimated during the periodic purging based on the feedback signal of the closed-loop exhaust gas oxygen sensor, and then used to suitably adjust the fuel injection quantity; see for example, the co-pending U.S. patent application Ser. No. 09/264,524, (Attorney Docket No. H-203439), filed on Mar. 8, 1999, assigned to the assignee of the present invention, and incorporated by reference herein. However, the disclosed approach cannot be used to estimate the purge vapor concentration during open-loop fuel control in a stratified combustion mode. Also, it is difficult to effectively purge stored fuel vapor while operating in the stratified combustion mode because the intake manifold pressure is significantly increased during stratified combustion, and the vapor that is successfully purged tends to burn incompletely. Accordingly, what is needed is a control method for a direct injection gasoline engine that regulates engine operation to efficiently purge stored fuel vapors while maintaining accurate fuel injection control during purging.
SUMMARY OF THE INVENTION
[0004] The present invention is directed to an improved control method for a direct injection gasoline engine operable in stratified or homogenous combustion modes and having a fuel vapor purge system, wherein the hydrocarbon concentration of purge vapor is estimated during open loop fuel control in the stratified combustion mode, and wherein the fuel injection quantity and the combustion mode are controlled based on the estimated concentration. The hydrocarbon concentration of the purge vapor is estimated during open-loop fuel control by measuring the air/fuel ratio error during steady state operation with no fuel vapor purging, and using the measured steady state air/fuel ratio error to normalize the air/fuel ratio error observed during steady state operation with purge control. The fuel injection quantity is compensated for the estimated purge vapor concentration, and engine combustion mode is determined in part based on a comparison of the estimated concentration with a calibrated threshold. Additionally, a limit on the percentage of purge vapor is determined as a function of combustion mode, and the flow rate is controlled based on the degree to which the percentage of purge vapor exceeds the determined limit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] [0005]FIG. 1 is a system diagram of a direct injection gasoline engine and control system including a microprocessor-based control unit and an evaporative emission system including a canister purge mechanism operated by the control unit.
[0006] FIGS. 2 - 5 are flow diagrams depicting a software routine executed by the control unit of FIG. 1 in carrying out the control of this invention. FIG. 2 depicts a main flow diagram, FIG. 3 details a portion of the main flow diagram concerning purge duty cycle control, FIG. 4 details a portion of the main flow diagram concerning selection of engine combustion mode, and FIG. 5 details a portion of the main flow diagram concerning estimation of the purge vapor concentration.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0007] The present invention is disclosed in the context of a control system for a direct injection gasoline engine generally designated by the reference numeral 10 . The control system includes a fuel control system 12 and an evaporative emission control system (EECS) 14 , both of which are controlled by a microprocessor-based engine control module (ECM) 16 . In general, the EECS 14 manages evaporative emissions by storing fuel vapor and periodically releasing all or a portion of the stored vapor to engine 10 for combustion therein, and the fuel control system 12 injects a determined amount of fuel into engine 10 , taking into account any fuel vapor supplied by EECS 14 . In the illustrated embodiment, the fuel injection system 12 includes a mass airflow (MAF) sensor 20 , and idle air control valve 22 , a throttle position sensor 24 , a manifold absolute pressure (MAP) sensor 26 , a fuel sender 28 , an engine speed sensor 30 , a number of electrically activated fuel injectors 32 , and a wide-range air/fuel (WRAF) exhaust gas sensor 34 . The EECS 14 primarily includes a charcoal canister 36 , electrically operated canister vent and purge valves 38 , 40 , and fuel tank pressure and temperature sensors 42 , 44 .
[0008] The ECM 16 executes a number of software routines for regulating the operation of the EECS 14 and the fuel control system 12 , including functions such as fuel quantity calculations, fuel injection control, and fuel vapor purge control. Thus, ECM 16 receives output signals from the above-mentioned sensors 20 , 24 , 26 , 28 , 30 , 34 , 42 , 44 , and develops outputs signals for controlling idle air control valve 22 , fuel injector 32 , canister vent valve 38 and purge valve 40 .
[0009] The fuel injectors 32 inject fuel directly into respective engine cylinders 54 , as shown, and one or more intake valves 55 at each cylinder 54 open during an intake stroke to admit intake air and purged fuel vapor, if any. The intake air is ingested through a throttle valve 56 , and an intake manifold 58 to which the various cylinders 54 are coupled by respective intake runners 60 . The idle air valve 22 provides a by-pass around throttle valve 56 , and its restriction is controlled by ECM 16 for purposes of regulating the engine idle speed. A piston 64 reciprocally disposed in each cylinder 54 and coupled to a rotary crankshaft 66 defines a combustion chamber 68 into which the fuel is injected. Following ignition of the air/fuel mixture by a spark plug (not shown), the products of combustion (that is, the exhaust gasses) exit the cylinder 54 through an exhaust valve 70 past WRAF sensor 34 to a catalytic converter and exhaust pipe (not shown). Operation of the engine 10 creates a sub-atmospheric pressure, or vacuum, in intake manifold 58 , and the vacuum draws stored fuel vapor from canister 36 into intake manifold 58 through purge valve 40 as fresh air is drawn into canister 36 via vent valve 38 . The fuel vapor stored in canister 36 originates in fuel tank 62 , and is supplied to canister 36 via a rollover valve 72 .
[0010] The ECM 16 controls the purge and vent valves 38 , 40 so that the purge vapor flow is a desired percentage of the engine airflow. This desired percentage, referred to herein as PURGE_PCT_LMT, is ordinarily varied as a function of engine speed and load, and according to this invention, is also varied based on the engine combustion mode. The combustion mode dependence of PURGE_PCT_LMT takes into account the fact that purge vapors burn more efficiently in the homogeneous combustion mode than in the stratified combustion mode.
[0011] Since the injectors 32 inject fuel directly into the respective combustion chambers 68 , the engine 10 may be operated either homogeneous or stratified combustion modes, depending on the timing of the fuel injection relative to the position of piston 64 in the engine cycle. In the homogeneous combustion mode, the ECM 16 activates injectors 32 while the respective intake valve 55 is open so that the air/fuel mixture is evenly distributed throughout the cylinder 54 when the mixture is ignited during the ensuing combustion stroke. In the stratified combustion mode, on the other hand, the ECM 16 activates injectors 32 just prior to the ignition event, resulting in a rich air/fuel mixture in the vicinity of the spark plug at ignition, even though the overall air/fuel ratio in the cylinder is controlled to a very lean ratio. In general, the homogeneous combustion mode is utilized primarily during medium to heavy engine load conditions, while the stratified combustion mode is utilized primarily during light engine load conditions.
[0012] In the homogeneous combustion mode, the ECM 16 executes a closed-loop control of the injected fuel to maintain the air/fuel ratio at a desired value, and purged fuel vapors delivered to intake manifold 58 burn very efficiently, provided the quantity of injected fuel is adjusted to take the purged fuel vapor into account. In this regard, the aforementioned U.S. patent application Ser. No. 09/264,524, discloses a technique for utilizing the air/fuel ratio feedback signal developed by an exhaust gas oxygen sensor during purging to estimate the hydrocarbon concentration of the purged fuel vapor for purposes of suitably adjusting the quantity of injected fuel. Specifically, the purge vapor concentration is estimated by an iterative process in which the estimate is incrementally increased or decreased during purge control if an integral of the measured air/fuel ratio error reaches respective rich or lean thresholds. When fuel vapor is not being purged, a conventional control utilizes the integral of the measured air/fuel ratio error to update a closed-loop adaptive learning table.
[0013] In the stratified combustion mode, the ECM 16 adjusts the injected fuel quantity open-loop to achieve a commanded engine torque output (or indicated mean effective pressure), and the throttle valve 56 is adjusted to maintain the air/fuel ratio approximately at a desired value significantly higher than the stoichiometric ratio. Under these conditions, the hydrocarbon concentration of the purge vapor cannot be estimated as disclosed in the aforementioned U.S. patent application Ser. No. 09/264,524 due to the sometimes substantial error between the actual and desired air/fuel ratio, even under steady-state operating conditions. Accordingly, a significant aspect of the present invention resides in a technique for estimating the hydrocarbon concentration of purge vapor while operating in the stratified combustion mode; the estimated concentration is used to suitably adjust the injected fuel quantity, and also to control the purge flow rate and select the combustion mode for engine 10 so as to assure efficient combustion of purged fuel vapors.
[0014] The flow diagrams of FIGS. 2 - 5 depict a software routine periodically executed by ECM 16 for carrying out a vapor purge and fuel injection control according to this invention. The blocks 80 and 82 are first executed to control activation of the electrically operated valves 38 , 40 of EECS 14 , and to select the combustion mode for engine 10 according to this invention. The steps involved in the purge control are illustrated in the flow diagram of FIG. 3, and the steps involved in selection of the combustion mode are illustrated in the flow diagram of FIG. 4.
[0015] If the homogeneous combustion mode is selected, the blocks 84 - 96 are executed substantially as described in the aforementioned U.S. Ser. No. 09/264,524 to determine the fuel injection quantity and update the purge concentration PURGE_CONC or block learn memory (BLM) tables. The base fuel per cylinder (BFPC) is determined at block 84 with a fully conventional closed-loop process based on a number of measured parameters such as MAP and TPS, the air/fuel ratio error AFR_ERROR determined from WRAF sensor output, and any adaptive corrections contained in the BLM. The block 86 then determines the quantity of fuel to be injected, taking into account the presence of purge vapors, if any. Thus, the determination of block 86 involves determining if vapor purging is active (as indicated by the status of the PURGE FLAG), and if so, suitably adjusting the BFPC value determined at block 84 . The adjustment of BFPC for purge vapor involves determining what percentage (PURGE_PCT) of BFPC is supplied by the purge vapor, and correspondingly reducing BFPC. The percentage PURGE_PCT in turn, is determined based on an estimate PURGE_CONC of the hydrocarbon concentration of the purge vapor (discussed below in reference to block 94 ), as follows:
PURGE โ PCT=(PURGE โ CONC*MFR purge* AFR )/ MFR intake โโ(1)
[0016] where AFR is the target air/fuel ratio, and MFRpurge and MFRintake are mass flow rates of the purge vapor and the intake air. The quantities MFRpurge and MFRintake may be measured or estimated based on various factors, as disclosed for example, in the U.S. Pat. No. 5,845,627, issued on Dec. 8, 1998, and incorporated herein by reference. The fuel to be injected per cylinder IFPC may then be determined as follows:
IFPC=BFPC (1โPURGE โ PCT ) โโ(2)
[0017] The injection of the quantity IFPC is then scheduled at block 88 for the proper timing relative to the engine cycle, and following combustion, the air/fuel ratio error (AFR_ERROR) is determined based on the output of WRAF sensor 34 and the desired air/fuel ratio. The block 92 then checks the PURGE FLAG to determine if vapor purging is active. If vapor purging is active, the block 94 is executed to update PURGE_CONC as a function of the integral of the air/fuel ratio error (AFR_ERROR_INT); otherwise, the block 96 is executed to update the BLM as a function of AFR_ERROR_INT. Both blocks 94 and 96 involve determining if the magnitude of AFR_ERROR_INT exceeds a threshold, and if so, incrementally increasing or decreasing PURGE_CONC. For example, if vapor purging is active and AFR_ERROR_INT indicates a rich fuel error in excess of the threshold, PURGE_CONC is incrementally increased, which results in the appropriate adjustment of fuel injection amount when the blocks 84 and 86 are next executed.
[0018] If the stratified combustion mode is selected at block 82 , the blocks 98 - 108 are executed as described below to determine the fuel injection quantity IFPC and update PURGE_CONC according to this invention. The base fuel per cylinder (BFPC) is determined at block 98 with a conventional open-loop process based on a number of measured parameters in order to produce a commanded engine torque. The block 100 then determines a purge combustion efficiency factor PURGE_EFF_FACTOR for adjusting BFPC to compensate for loss of engine torque output due to inefficient combustion of purge vapors. If vapor purging is active, PURGE_EFF_FACTOR is determined by table look-up as a function of the delivered air/fuel ratio AFR. In general, empirical testing has shown that the purge vapor combustion efficiency decreases with increasing values of AFR, and PURGE_EFF_FACTOR is essentially a normalized indication of such efficiency. The block 102 then determines the injected fuel per cylinder IFPC. If vapor purging is active (as indicated by the status of the PURGE FLAG), the BFPC value determined at block 98 is adjusted as a function of PURGE_PCT, and PURGE_EFF_FACTOR as follows:
IFPC=BFPC[ 1โ(PURGE โ PCT *PURGE โ EFF _FACTOR)]โโ(3)
[0019] The injection of the quantity IFPC is then scheduled at block 104 for the proper timing relative to the engine cycle, and following combustion, the air/fuel ratio error AFR_ERROR is determined based on the output of WRAF sensor 34 . The block 92 is then executed to update PURGE_CONC according to this invention as described below in reference to the flow diagram of FIG. 5.
[0020] The flow diagram of FIG. 3 details the purge control block 80 of FIG. 2, and involves determining a control signal for activating the purge valve 40 to produce a desired flow of purge vapor. In the illustrated embodiment, this involves determining a desired percentage of purge vapor (PURGE_PCT_LMT) based on engine speed and load (ES, LOAD) and the selected combustion mode (COMB_MODE) as indicated at block 110 , and then determining a PWM duty cycle (PURGE_DC) based on the deviation of the current purge vapor percent (PURGE_PCT) from PURGE_PCT_LMT. The dependency of PURGE_PCT_LMT on COMB_MODE reflects the fact that purge vapors will burn much more efficiently in the homogenous combustion mode than in the stratified mode; accordingly, PURGE_PCT_LMT can be scheduled for maximizing combustion of purge vapor. The current purge vapor percent, PURGE_PCT, is determined at block 111 as a function of the air/fuel ratio (AFR), the purge vapor mass flow rate (MFRpurge), the intake mass flow rate (MFRintake) and the estimated hydrocarbon concentration PURGE_CONC of the purge vapor, as given above in equation (1). If PURGE_PCT is less than or equal to PURGE_PCT_LMT, as determined at block 112 , the block 114 sets the duty cycle PURGE_DC_NEW to a value based on PURGE_PCT_LMT, the air/fuel ratio error AFR_ERROR, and the measured mass air flow MAF. If AFR_ERROR is reasonably low, the duty cycle PURGE_DC is adjusted to achieve PURGE_PCT_LMT; however, PURGE_DC is controlled to achieve a value less than PURGE_PCT_LMT if AFR_ERROR indicates that there is significant fueling error. If PURGE_PCT is greater than PURGE_PCT_LMT, the blocks 116 , 118 and 120 are executed to ramp down PURGE_DC at a determined rate. The blocks 116 and 118 determine a ramp factor PRF, and block 120 sets PURGE_DC equal to the product of PURGE_DC and PRF. The value of PRF computed at block 116 according to the expression:
PRF=(Kfast _rate*PURGE โ PCT โ LMT /PURGE โ PCT )+[(1โKfast_rate)*Kslow_rate]โโ(4)
[0021] where Kfast_rate and Kslow_rate are calibrated values corresponding to the predetermined changes per unit time in the value of PURGE_DC. For example, Kfast_rate may be 0.60, corresponding to a 40% reduction of PURGE_DC each time block 120 is executed, and Kslow_rate may be 0.95, corresponding to a 5% reduction of PURGE_DC each time block 120 is executed. Thus, if PURGE_PCT is only slightly higher than PURGE_PCT_LMT, as may occur in normal purge control, PRF will be approximately equal to Kslow_rate. On the other hand, if PURGE_PCT is significantly higher than PURGE_PCT_LMT, as may occur when the combustion mode switches from homogeneous to stratified, the product [Kfast_rate*(PURGE_PCT_LMT/PURGE_PCT)] becomes smaller, resulting in a smaller value of PRF and a faster reduction of PURGE_DC. The block 118 sets the purge rate factor PRF equal to the lower of the PRF value computed at block 116 and Kslow_rate, and block 120 sets PURGE_DC equal to the product (PURGE_DC*PRF). Thus, when the combustion mode switches from homogeneous to stratified, resulting in an abrupt reduction in PURGE_PCT_LMT, the blocks 116 - 120 produce an initially fast reduction of PURGE_DC that falls exponentially to Kslow_rate as PURGE_PCT approaches PURGE_PCT_LMT.
[0022] The flow diagram of FIG. 4 details the block 82 of FIG. 2, and concerns selection of the engine combustion mode COMB_MODE. Ordinarily, COMB_MODE is selected based on the engine speed and load (ES, LOAD), as indicated at block 130 . According to this invention, however, the blocks 122 - 128 are first executed to determine the status of a flag (STRAT_DISABLE FLAG) for disabling selection of the stratified mode when the estimated hydrocarbon concentration PURGE_CONC of the purge vapors exceed a threshold MAX_PURGE. The blocks 122 and 124 set the STRAT_DISABLE FLAG to TRUE to disable the stratified mode when PURGE_CONC exceeds MAX_PURGE, and the blocks 126 and 128 set the STRAT_DISABLE FLAG to FALSE when PURGE_CONC falls below (MAX_PURGE-Khys), where Khys is a hysteresis constant. Thus, the engine combustion mode is essentially forced to be homogeneous whenever PURGE_CONC exceeds MAX_PURGE. In such case, the increased vacuum causes the purge consumption to increase dramatically, preventing saturation of the canister 36 , and eventually enabling a return to the stratified combustion mode when the PURGE_CONC falls below (MAX_PURGE-Khys).
[0023] The flow diagram of FIG. 5 details the block 108 of FIG. 2, and concerns updating the estimated hydrocarbon concentration PURGE_CONC of the purge vapor during open-loop fuel control in the stratified combustion mode. The blocks 138 - 142 determine whether the engine 10 is operating substantially steady-state, and set the state of the ENG_STA FLAG accordingly. The block 138 determines if the engine 10 is operating substantially steady-state. This may be determined, for example, by determining if speed vs. load operating point of engine 10 has been substantially constant for a predetermined interval. If block 138 is answered in the negative, the block 140 sets ENG_STA_FLAG to FALSE, and resets a timer ENG_STA_TMR to zero. If block 138 is answered in the affirmative, the block 142 sets ENG_STA_FLAG to TRUE, and increments ENG_STA_TMR. When the value of ENG_STA_TMR exceeds a reference time REF 1 , as determined at block 144 , the block 146 determines if there is a flow of purge vapor into intake manifold 58 . If MFRpurge is zero, the block 148 updates a measure (SS_AFR_ERROR) of the steady-state air/fuel ratio error by updating a running average, or filter, of AFR_ERROR. If there is a flow of purge vapor, the block 150 obtains a running average of the AFR_ERROR, and computes a measure (NORM_PURGE_ERROR) of the air/fuel ratio error due to the presence of the purge vapor by dividing the averaged value of AFR_ERROR with purge flow by SS_AFR_ERROR. This essentially normalizes or compensates the filtered air/fuel ratio error during purge flow for air/fuel ratio error (rich or lean) that existed without purge flow. Under closed-loop fuel control, such normalization is not necessary because the closed-loop corrections obtained from the block learn memory (BLM) in the absence of purge vapor drive the air/fuel ratio to substantially zero. If specified purge learning enable conditions are met for at least a reference time REF 2 , as determined at blocks 152 , 154 , 156 and 158 , the blocks 160 , 162 , 164 and 166 increment or decrement the purge hydrocarbon concentration estimate PURGE_CONC for the current speed vs. load operating point of engine 10 based on the value of NORM_PURGE_ERROR relative to upper and lower thresholds THRhi, THRlo. If NORM_PURGE_ERROR exceeds THRhi, the air/fuel ratio is too lean in the presence of purge vapor; this means that the fuel control of block 102 is over-compensating for the purge vapor, and the block 160 is executed to decrement the estimated value of PURGE_CONC. Conversely, if NORM_PURGE_ERROR is below THRlo, the air/fuel ratio is too rich in the presence of purge vapor; this means that the fuel control of block 102 is under-compensating for the purge vapor, and the block 164 is executed to increment the estimated value of PURGE_CONC. The learning enable conditions mentioned in reference to block 150 relate primarily to purge flow, and ensure that there is sufficient purge flow to have a measurable impact on air/fuel ratio.
[0024] In summary, the control of the present invention permits accurate fueling and efficient combustion of purge vapors in a direct injection gasoline engine operable in stratified or homogenous combustion modes. The control has several aspects, including accurate estimation of the hydrocarbon concentration of purge vapor during open loop fuel control in the stratified combustion mode, adjustment of the fuel injection quantity based on the estimated concentration and a purge combustion efficiency factor, disabling of the stratified combustion mode based on the estimated concentration relative to a calibrated threshold, determining the allowable percentage of purge vapor based on the selected combustion mode, and controlling the purge flow rate based on the degree to which the estimated concentration exceeds the allowable percentage.
[0025] While the present invention has been described in reference to the illustrated embodiments, it is expected that various modification in addition to those mentioned above will occur to those skilled in the art. For example, there may be additional combustion modes, such as a lean or rich air/fuel ratio homogeneous mode, in which case, the control of this invention will schedule PURGE_PCT_LMT for each combustion mode, and will disable all lean combustion modes if PURGE_CONC exceeds the disable threshold MAX_PURGE. Thus, it will be understood that methods incorporating these and other modifications may fall within the scope of this invention, which is defined by the appended claims.
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A control method for a direct injection gasoline engine operable in stratified or homogenous combustion modes and having a fuel vapor purge system estimates the hydrocarbon concentration of purge vapor during open loop fuel control in the stratified combustion mode, and controls the fuel injection quantity and the combustion mode based on the estimated concentration. The hydrocarbon concentration of the purge vapor is estimated during open-loop fuel control by measuring the air/fuel ratio error during steady state operation with no fuel vapor purging, and using the measured steady state air/fuel ratio error to normalize the air/fuel error observed during steady state operation with purge control. The fuel injection quantity is compensated for the estimated purge vapor concentration, and engine combustion mode is determined in part based on a comparison of the estimated concentration with a calibrated threshold. Additionally, a limit on the percentage of purge vapor is determined as a function of combustion mode, and the flow rate is controlled based on the degree to which the percentage of purge vapor exceeds the determined limit.
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